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Biomolecules, Volume 9, Issue 9 (September 2019)

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Cover Story (view full-size image) We have shown that poly(phosphorhydrazone) (PPH) dendrimers of the first generation capped with [...] Read more.
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Open AccessArticle
Mutational Analysis of a Highly Conserved PLSSMXP Sequence in the Small Subunit of Bacillus licheniformis γ-Glutamyltranspeptidase
Biomolecules 2019, 9(9), 508; https://doi.org/10.3390/biom9090508 - 19 Sep 2019
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Abstract
A highly conserved 458PLSSMXP464 sequence in the small subunit (S-subunit) of an industrially important Bacillus licheniformis γ-glutamyltranspeptidase (BlGGT) was identified by sequence alignment. Molecular structures of the precursor mimic and the mature form of BlGGT clearly reveal that [...] Read more.
A highly conserved 458PLSSMXP464 sequence in the small subunit (S-subunit) of an industrially important Bacillus licheniformis γ-glutamyltranspeptidase (BlGGT) was identified by sequence alignment. Molecular structures of the precursor mimic and the mature form of BlGGT clearly reveal that this peptide sequence is in close spatial proximity to the self-processing and catalytic sites of the enzyme. To probe the role of this conserved sequence, ten mutant enzymes of BlGGT were created through a series of deletion and alanine-scanning mutagenesis. SDS-PAGE and densitometric analyses showed that the intrinsic ability of BlGGT to undergo autocatalytic processing was detrimentally affected by the deletion-associated mutations. However, loss of self-activating capacity was not obviously observed in most of the Ala-replacement mutants. The Ala-replacement mutants had a specific activity comparable to or greater than that of the wild-type enzyme; conversely, all deletion mutants completely lost their enzymatic activity. As compared with BlGGT, S460A and S461S showed greatly enhanced kcat/Km values by 2.73- and 2.67-fold, respectively. The intrinsic tryptophan fluorescence and circular dichroism spectral profiles of Ala-replacement and deletion mutants were typically similar to those of BlGGT. However, heat and guanidine hydrochloride-induced unfolding transitions of the deletion-associated mutant proteins were severely reduced as compared with the wild-type enzyme. The predictive mutant models suggest that the microenvironments required for both self-activation and catalytic reaction of BlGGT can be altered upon mutations. Full article
(This article belongs to the Section Biochemistry)
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Open AccessCommunication
Proteolytic Activity in Meadow Soil after the Application of Phytohormones
Biomolecules 2019, 9(9), 507; https://doi.org/10.3390/biom9090507 - 19 Sep 2019
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Abstract
Phytohormones, similar to soil enzymes, are synthesized and secreted into the soil environment by fungi and microorganisms. Phytohormones are involved in regulating microbial community activity in the rhizosphere. This paper examines how auxins, cytokinins, ethephon and chlorocholine chloride affect the activity of native [...] Read more.
Phytohormones, similar to soil enzymes, are synthesized and secreted into the soil environment by fungi and microorganisms. Phytohormones are involved in regulating microbial community activity in the rhizosphere. This paper examines how auxins, cytokinins, ethephon and chlorocholine chloride affect the activity of native soil proteases in the organo-mineral horizon of an alpine meadow. In the meadow habitat, native soil proteases were inhibited by auxins whereas the effect of cytokinins on these enzymes was not statistically significant. A similar inhibitory effect on the activity of proteases was shown for ethephon and chlorocholine chloride, both of which also inhibited the activity of native soil proteases in the alpine meadow soil. Overall, the inhibitory effect of phytohormones on the activity of native protease activity may affect plant nutrition by retarding the nitrogen cycle in the soil. This work contributes to our understanding of the influence of substances produced by the rhizosphere that can actively participate in the activity of soil microorganisms and consequently influence the soil nitrogen cycle. Full article
(This article belongs to the Special Issue Phytohormones)
Open AccessArticle
Mechanical Deformation and Electronic Structure of a Blue Copper Azurin in a Solid-State Junction
Biomolecules 2019, 9(9), 506; https://doi.org/10.3390/biom9090506 - 19 Sep 2019
Viewed by 362
Abstract
Protein-based electronics is an emerging field which has attracted considerable attention over the past decade. Here, we present a theoretical study of the formation and electronic structure of a metal-protein-metal junction based on the blue-copper azurin from pseudomonas aeruginosa. We focus on the [...] Read more.
Protein-based electronics is an emerging field which has attracted considerable attention over the past decade. Here, we present a theoretical study of the formation and electronic structure of a metal-protein-metal junction based on the blue-copper azurin from pseudomonas aeruginosa. We focus on the case in which the protein is adsorbed on a gold surface and is contacted, at the opposite side, to an STM (Scanning Tunneling Microscopy) tip by spontaneous attachment. This has been simulated through a combination of molecular dynamics and density functional theory. We find that the attachment to the tip induces structural changes in the protein which, however, do not affect the overall electronic properties of the protein. Indeed, only changes in certain residues are observed, whereas the electronic structure of the Cu-centered complex remains unaltered, as does the total density of states of the whole protein. Full article
(This article belongs to the Special Issue Biomolecular Electronics)
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Open AccessArticle
Elevated SH3BP5 Correlates with Poor Outcome and Contributes to the Growth of Acute Myeloid Leukemia Cells
Biomolecules 2019, 9(9), 505; https://doi.org/10.3390/biom9090505 - 19 Sep 2019
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Abstract
Current strategies are not especially successful in the treatment of acute myeloid leukemia (AML). The identification and characterization of oncogenes crucial to the survival and growth of leukemia cells will provide potential targets for the exploitation of novel therapies. Herein, we report that [...] Read more.
Current strategies are not especially successful in the treatment of acute myeloid leukemia (AML). The identification and characterization of oncogenes crucial to the survival and growth of leukemia cells will provide potential targets for the exploitation of novel therapies. Herein, we report that the elevated expression of SH3 domain-binding protein 5 (SH3BP5) significantly correlates with poor outcomes of AML patients. To test whether SH3BP5 contributes to the growth and survival of AML cells, we use the shRNA-encoding lentivirus system to achieve the knockdown of SH3BP5 expression in human AML cell lines U937, THP-1, Kasumi-1, and MV4-11. Functionally, the knockdown of SH3BP5 expression markedly inhibits the cell viability and induced apoptosis of these leukemia cells. Mechanistically, western blot analysis indicates that the knockdown of SH3BP5 expression decreases the phosphorylation of JNK and BAD. Moreover, the JNK agonist anisomycin rescues the growth inhibition phenotype of SH3BP5 deficiency in THP-1 cells. Moreover, the expression of SH3BP5 positively correlates with CD25 and CD123 levels. Finally, our study highlights the crucial role of SH3BP5 in promoting the survival of AML cells, and its suppression may be a potential therapeutic strategy for treating human AML. Full article
(This article belongs to the Special Issue New Targets and Strategies in Regenerative Medicine)
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Open AccessArticle
Integrative Analysis of the Core Fruit Lignification Toolbox in Pear Reveals Targets for Fruit Quality Bioengineering
Biomolecules 2019, 9(9), 504; https://doi.org/10.3390/biom9090504 - 18 Sep 2019
Viewed by 294
Abstract
Stone cell content is an important factor affecting pear fruit flavor. Lignin, a major component of pear stone cells, hinders the quality and value of commercial fruit. The completion of the Chinese white pear (Pyrus bretschneideri) genome sequence provides an opportunity [...] Read more.
Stone cell content is an important factor affecting pear fruit flavor. Lignin, a major component of pear stone cells, hinders the quality and value of commercial fruit. The completion of the Chinese white pear (Pyrus bretschneideri) genome sequence provides an opportunity to perform integrative analysis of the genes encoding the eleven protein families (i.e., PAL, C4H, 4CL, HCT, C3H, CSE, CCoAOMT, CCR, F5H, COMT, and CAD) in the phenylpropanoid pathway. Here, a systematic study based on expression patterns and phylogenetic analyses was performed to identify the members of each gene family potentially involved in the lignification in the Chinese white pear. The phylogenetic analysis suggested that 35 P. bretschneideri genes belong to bona fide lignification clade members. Compared to other plants, some multigene families are expanded by tandem gene duplication, such as HCT, C3H, COMT, and CCR. RNA sequencing was used to study the expression patterns of the genes in different tissues, including leaf, petal, bud, sepal, ovary, stem, and fruit. Eighteen genes presented a high expression in fruit, indicating that these genes may be involved in the biosynthesis of lignin in pear fruit. Similarly to what has been observed for Populus trichocarpa, a bimolecular fluorescence complementation (BiFC) experiment indicated that P. bretschneideri C3H and C4H might also interact with each other to regulate monolignol biosynthesis in P. bretschneideri, ultimately affecting the stone cell content in pear fruits. The identification of the major genes involved in lignin biosynthesis in pear fruits provides the basis for the development of strategies to improve fruit quality. Full article
(This article belongs to the Section Bioinformatics and Systems Biology)
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Open AccessArticle
G-Protein-Coupled Estrogen Receptor (GPER)-Specific Agonist G1 Induces ER Stress Leading to Cell Death in MCF-7 Cells
Biomolecules 2019, 9(9), 503; https://doi.org/10.3390/biom9090503 - 18 Sep 2019
Viewed by 358
Abstract
The G-protein-coupled estrogen receptor (GPER) mediates rapid non-genomic effects of estrogen. Although GPER is able to induce proliferation, it is down-regulated in breast, ovarian and colorectal cancer. During cancer progression, high expression levels of GPER are favorable for patients’ survival. The GPER-specific agonist [...] Read more.
The G-protein-coupled estrogen receptor (GPER) mediates rapid non-genomic effects of estrogen. Although GPER is able to induce proliferation, it is down-regulated in breast, ovarian and colorectal cancer. During cancer progression, high expression levels of GPER are favorable for patients’ survival. The GPER-specific agonist G1 leads to an inhibition of cell proliferation and an elevated level of intracellular calcium (Ca2+). The purpose of this study is to elucidate the mechanism of G1-induced cell death by focusing on the connection between G1-induced Ca2+ depletion and endoplasmic reticulum (ER) stress in the estrogen receptor positive breast cancer cell line MCF-7. We found that G1-induced ER Ca2+ efflux led to the activation of the unfolded protein response (UPR), indicated by the phosphorylation of IRE1α and PERK and the cleavage of ATF6. The pro-survival UPR signaling was activated via up-regulation of the ER chaperon protein GRP78 and translational attenuation indicated by eIF2-α phosphorylation. However, the accompanying pro-death UPR signaling is profoundly activated and responsible for ER stress-induced cell death. Mechanistically, PERK-phosphorylation-induced JNK-phosphorylation and IRE1α-phosphorylation, which further triggered CAMKII-phosphorylation, are both implicated in G1-induced cell death. Our study indicates that loss of ER Ca2+ is responsible for G1-induced cell death via the pro-death UPR signaling. Full article
(This article belongs to the Special Issue Mechanisms of Cell Death in Disease: A New Therapeutic Opportunity)
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Open AccessArticle
Noncovalent Immobilization of Yarrowia lipolytica Lipase on Dendritic-Like Amino Acid-Functionalized Silica Nanoparticles
Biomolecules 2019, 9(9), 502; https://doi.org/10.3390/biom9090502 - 18 Sep 2019
Viewed by 254
Abstract
Immobilization of enzymes is a promising approach for the cost-effective application of enzymes. Among others, noncovalent but unleachable approaches for immobilization are one of the most favorable and crucial approaches. Herein, silica nanoparticles are modified by (3-aminopropyl)triethoxysilane (APTES) to generate amino-functionalized silica nanoparticles. [...] Read more.
Immobilization of enzymes is a promising approach for the cost-effective application of enzymes. Among others, noncovalent but unleachable approaches for immobilization are one of the most favorable and crucial approaches. Herein, silica nanoparticles are modified by (3-aminopropyl)triethoxysilane (APTES) to generate amino-functionalized silica nanoparticles. Then, the amine functionalities are converted to bifunctional amino acid via post-modification that has zwitterionic properties. This nanostructure with the new functional theme is employed to immobilize Yarrowia lipolytica lipase at room temperature with no further post-modification or cross-linking. This immobilization method is further compared with the metal chelate-based immobilization approach on the same support. The biocatalytic activity of the immobilized lipase is examined under various conditions. The encapsulation of lipase through amino acid-functionalized silica nanoparticles exhibited enhanced stability for the immobilized lipase at higher temperatures and unneutral pHs. Full article
(This article belongs to the Section Biochemistry)
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Open AccessArticle
Immunomodulatory Functions of the Human Cathelicidin LL-37 (aa 13–31)-Derived Peptides are Associated with Predicted α-Helical Propensity and Hydrophobic Index
Biomolecules 2019, 9(9), 501; https://doi.org/10.3390/biom9090501 - 18 Sep 2019
Viewed by 308
Abstract
The anti-endotoxin activity of the cationic peptide LL-37 and its derivative IG-19 is attributed to electrostatic interaction of the peptides’ positive charge with negatively charged bacterial lipopolysaccharides (LPS), and in part to the alteration of intracellular mechanisms independent of peptide binding to LPS. [...] Read more.
The anti-endotoxin activity of the cationic peptide LL-37 and its derivative IG-19 is attributed to electrostatic interaction of the peptides’ positive charge with negatively charged bacterial lipopolysaccharides (LPS), and in part to the alteration of intracellular mechanisms independent of peptide binding to LPS. We examined the immunomodulatory responses induced by IG-19 and four IG-19-derived scrambled peptides (IG-19a–d), in the presence and absence of LPS, in macrophages and peripheral blood-derived mononuclear cells. All peptides had identical net charge (+5) and amino acid composition, but different hydrophobicity and α-helical propensity. Peptide IG-19 suppressed LPS-induced cytokine/chemokine production by >90%, IG-19a and IG-19b suppressed it by 40–50%, and IG-19c and IG-19d did not suppress cytokine/chemokine production at all. In silico prediction algorithms and the peptide retention time (RT) on a C18 RP HPLC column indicated a linear association between α-helical propensity and hydrophobicity with the ability of the peptides to inhibit LPS-induced responses. Peptide RT exhibited a significant correlation (>70%) between the suppression of LPS-induced cytokine/chemokine production and peptide-induced production of the anti-inflammatory cytokine IL-1RA. These results indicate that RT on a C18 column can be used as a predictor for the immunomodulatory functions of cationic peptides. Overall, we demonstrated that the immunomodulatory functions of LL-37-derived peptides with identical positive charge and amino acid composition are directly associated with the predicted α-helical propensity and hydrophobicity of the peptides. Full article
(This article belongs to the Special Issue Structure and Function of Antimicrobial Peptides)
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Open AccessArticle
Effects of Fludioxonil on the Cell Growth and Apoptosis in T and B Lymphocytes
Biomolecules 2019, 9(9), 500; https://doi.org/10.3390/biom9090500 - 18 Sep 2019
Viewed by 325
Abstract
Fludioxonil is fungicide used in agriculture, which is present in fruits and vegetables. In this study, the effects of fludioxonil on human immune cell viability, apoptosis, cell cycle arrest, and mitochondrial membrane potential were examined in human immune cells, such as Jurkat T [...] Read more.
Fludioxonil is fungicide used in agriculture, which is present in fruits and vegetables. In this study, the effects of fludioxonil on human immune cell viability, apoptosis, cell cycle arrest, and mitochondrial membrane potential were examined in human immune cells, such as Jurkat T cells and Ramos B cells. To examine the cell viability, Jurkat T cells and Ramos B cells were treated with fludioxonil (10−9–10−5 M) for 24 h and 48 h. Water soluble tetrazolium salt assay showed that fludioxonil decreased Jurkat T cell and Ramos B cell viability. Jurkat T cell viability decreased at 24 and 48 h, but Ramos B cell viability decreased only at 48 h. JC-1 dye revealed decreased mitochondrial membrane potential in fludioxonil-treated Jurkat T cells and Ramos B cells. To evaluate apoptosis, annexin-V conjugated FITC, AF488, and propidium iodide (PI) were used and to evaluate cell cycle arrest PI was used. Apoptosis and cell cycle arrest were induced by fludioxonil (10−7–10−5 M) in the Jurkat T cells at 24 and 48 h and Ramos B cells at 48 h. Moreover, the protein levels of pro-apoptotic proteins, such as p53, BAX, and cleaved caspase 3, were increased and anti-apoptotic protein Bcl-2 was decreased by fludioxonil. Expression of the Fas receptor related to the extrinsic apoptosis pathway was increased by fludioxonil. Additionally, cyclin D1 and cyclin E1 were decreased by fludioxonil. In the present study, fludioxonil induced immunotoxicity in human T cells and B cells through apoptosis and cell cycle arrest. Therefore, the present study suggests that fludioxonil induces the cellular toxicity in immune cells. Full article
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Open AccessArticle
Creation of Cybrid Cultures Containing mtDNA Mutations m.12315G>A and m.1555G>A, Associated with Atherosclerosis
Biomolecules 2019, 9(9), 499; https://doi.org/10.3390/biom9090499 - 18 Sep 2019
Viewed by 317
Abstract
In the present work, a pilot creation of four cybrid cultures with high heteroplasmy level was performed using mitochondrial genome mutations m.12315G>A and m.1555G>A. According to data of our preliminary studies, the threshold heteroplasmy level of mutation m.12315G>A is associated with atherosclerosis. At [...] Read more.
In the present work, a pilot creation of four cybrid cultures with high heteroplasmy level was performed using mitochondrial genome mutations m.12315G>A and m.1555G>A. According to data of our preliminary studies, the threshold heteroplasmy level of mutation m.12315G>A is associated with atherosclerosis. At the same time, for a mutation m.1555G>A, such a heteroplasmy level is associated with the absence of atherosclerosis. Cybrid cultures were created by fusion of rho0-cells and mitochondria from platelets with a high heteroplasmy level of the investigated mutations. To create rho0-cells, THP-1 culture of monocytic origin was taken. According to the results of the study, two cybrid cell lines containing mutation m.12315G>A with the heteroplasmy level above the threshold value (25% and 44%, respectively) were obtained. In addition, two cybrid cell lines containing mutation m.1555G>A with a high heteroplasmy level (24%) were obtained. Cybrid cultures with mtDNA mutation m.12315G>A can be used to model both the occurrence and development of atherosclerosis in cells and the titration of drug therapy for patients with atherosclerosis. With the help of cybrid cultures containing single nucleotide replacement of mitochondrial genome m.1555G>A, it is possible to develop approaches to the gene therapy of atherosclerosis. Full article
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Open AccessArticle
Computationally Designed Peptides for Zika Virus Detection: An Incremental Construction Approach
Biomolecules 2019, 9(9), 498; https://doi.org/10.3390/biom9090498 - 17 Sep 2019
Viewed by 444
Abstract
Herein, and in contrast to current production of anti-Zika virus antibodies, we propose a semi-combinatorial virtual strategy to select short peptides as biomimetic antibodies/binding agents for the detection of intact Zika virus (ZIKV) particles. The virtual approach was based on generating different docking [...] Read more.
Herein, and in contrast to current production of anti-Zika virus antibodies, we propose a semi-combinatorial virtual strategy to select short peptides as biomimetic antibodies/binding agents for the detection of intact Zika virus (ZIKV) particles. The virtual approach was based on generating different docking cycles of tetra, penta, hexa, and heptapeptide libraries by maximizing the discrimination between the amino acid motif in the ZIKV and dengue virus (DENV) envelope protein glycosylation site. Eight peptides, two for each length (tetra, penta, hexa, and heptapeptide) were then synthesized and tested vs. intact ZIKV particles by using a direct enzyme linked immunosorbent assay (ELISA). As a reference, we employed a well-established anti-ZIKV antibody, the antibody 4G2. Three peptide-based assays had good detection limits with dynamic range starting from 105 copies/mL of intact ZIKV particles; this was one order magnitude lower than the other peptides or antibodies. These three peptides showed slight cross-reactivity against the three serotypes of DENV (DENV-1, -2, and -3) at a concentration of 106 copies/mL of intact virus particles, but the discrimination between the DENV and ZIKV was lost when the coating concentration was increased to 107 copies/mL of the virus. The sensitivity of the peptides was tested in the presence of two biological matrices, serum and urine diluted 1:10 and 1:1, respectively. The detection limits decreased about one order of magnitude for ZIKV detection in serum or urine, albeit still having for two of the three peptides tested a distinct analytical signal starting from 106 copies/mL, the concentration of ZIKV in acute infection. Full article
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Open AccessCommunication
Protein Engineering of Multi-Modular Transcription Factor Alcohol Dehydrogenase Repressor 1 (Adr1p), a Tool for Dissecting In Vitro Transcription Activation
Biomolecules 2019, 9(9), 497; https://doi.org/10.3390/biom9090497 - 17 Sep 2019
Viewed by 301
Abstract
Studying transcription machinery assembly in vitro is challenging because of long intrinsically disordered regions present within the multi-modular transcription factors. One example is alcohol dehydrogenase repressor 1 (Adr1p) from fermenting yeast, responsible for the metabolic switch from glucose to ethanol. The role of [...] Read more.
Studying transcription machinery assembly in vitro is challenging because of long intrinsically disordered regions present within the multi-modular transcription factors. One example is alcohol dehydrogenase repressor 1 (Adr1p) from fermenting yeast, responsible for the metabolic switch from glucose to ethanol. The role of each individual transcription activation domain (TAD) has been previously studied, but their interplay and their roles in enhancing the stability of the protein is not known. In this work, we designed five unique miniAdr1 constructs containing either TADs I-II-III or TAD I and III, connected by linkers of different sizes and compositions. We demonstrated that miniAdr1-BL, containing only PAR-TAD I+III with a basic linker (BL), binds the cognate DNA sequence, located in the promoter of the ADH2 (alcohol dehydrogenase 2) gene, and is necessary to stabilize the heterologous expression. In fact, we found that the sequence of the linker between TAD I and III affected the solubility of free miniAdr1 proteins, as well as the stability of their complexes with DNA. miniAdr1-BL is the stable unit able to recognize ADH2 in vitro, and hence it is a promising tool for future studies on nucleosomal DNA binding and transcription machinery assembly in vitro. Full article
(This article belongs to the Section Biochemistry)
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Open AccessReview
Creatine as a Candidate to Prevent Statin Myopathy
Biomolecules 2019, 9(9), 496; https://doi.org/10.3390/biom9090496 - 17 Sep 2019
Viewed by 364
Abstract
Statins prevent cardiovascular diseases, yet their use is limited by the muscle disturbances they cause. Rarely, statin-induced myopathy is autoimmune, but more commonly it is due to direct muscle toxicity. Available evidence suggests that statin-induced creatine deficiency might be a major cause of [...] Read more.
Statins prevent cardiovascular diseases, yet their use is limited by the muscle disturbances they cause. Rarely, statin-induced myopathy is autoimmune, but more commonly it is due to direct muscle toxicity. Available evidence suggests that statin-induced creatine deficiency might be a major cause of this toxicity, and that creatine supplementation prevents it. Statins inhibit guanidinoacetate methyl transferase (GAMT), the last enzyme in the synthesis of creatine; thus, they decrease its intracellular content. Such decreased content could cause mitochondrial impairment, since creatine is the final acceptor of the phosphate group of adenosine triphosphate (ATP) at the end of mitochondrial oxidative phosphorylation. Decreased cellular synthesis of ATP would follow. Accordingly, ATP synthesis is decreased in statin-treated cells. In vitro, creatine supplementation prevents the opening of the mitochondrial permeability transition pore that is caused by statins. Clinically, creatine administration prevents statin myopathy in statin-intolerant patients. Additional research is warranted to hopefully confirm these findings. However, creatine is widely used by athletes with no adverse events, and has demonstrated to be safe even in double-blind, placebo-controlled trials of elderly individuals. Thus, it should be trialed, under medical supervision, in patients who cannot assume statin due to the occurrence of muscular symptoms. Full article
(This article belongs to the Special Issue Creatine as a Therapeutic Strategy)
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Open AccessArticle
Unraveling Binding Mechanism of Alzheimer’s Drug Rivastigmine Tartrate with Human Transferrin: Molecular Docking and Multi-Spectroscopic Approach towards Neurodegenerative Diseases
Biomolecules 2019, 9(9), 495; https://doi.org/10.3390/biom9090495 - 17 Sep 2019
Viewed by 262
Abstract
Studying drug–protein interactions has gained significant attention lately, and this is because the majority of drugs interact with proteins, thereby altering their structure and, moreover, their functionality. Rivastigmine tartrate (RT) is a drug that is in use for mild to moderate Alzheimer therapy. [...] Read more.
Studying drug–protein interactions has gained significant attention lately, and this is because the majority of drugs interact with proteins, thereby altering their structure and, moreover, their functionality. Rivastigmine tartrate (RT) is a drug that is in use for mild to moderate Alzheimer therapy. This study was targeted to characterize the interaction between human transferrin (hTf) and RT by employing spectroscopy, isothermal titration calorimetry (ITC), and molecular docking studies. Experimental results of fluorescence quenching of hTf induced by RT implied the formation of a static complex between hTf and RT. Further elucidation of the observed fluorescence data retorting Stern–Volmer and modified Stern–Volmer resulted in binding constants for hTf–RT complex of the order 104 M−1 over the studied temperatures. Thermodynamic parameters of hTf–RT interaction were elucidated further by employing these obtained binding constant values. It was quite evident from obtained thermodynamic attributes that RT spontaneously binds to hTf with a postulated existence of hydrogen bonding or Van der Waals forces. Further, Circular dichroism spectroscopy (CD) also confirmed RT–hTf complex formation owing to upward movement of CD spectra in the presence of RT. ITC profiles advocated the existence of reaction to be spontaneous. Moreover, molecular docking further revealed that the important residues play a pivotal role in RT–hTf interaction. The findings of this study can be of a significant benefit to the drug-designing industry in this disease-prone era. Full article
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Open AccessArticle
Crinamine Induces Apoptosis and Inhibits Proliferation, Migration, and Angiogenesis in Cervical Cancer SiHa Cells
Biomolecules 2019, 9(9), 494; https://doi.org/10.3390/biom9090494 - 16 Sep 2019
Viewed by 428
Abstract
Crinum asiaticum is a perennial herb widely distributed in many warmer regions, including Thailand, and is well-known for its medicinal and ornamental values. Crinum alkaloids contain numerous compounds, such as crinamine. Even though its mechanism of action is still unknown, crinamine was previously [...] Read more.
Crinum asiaticum is a perennial herb widely distributed in many warmer regions, including Thailand, and is well-known for its medicinal and ornamental values. Crinum alkaloids contain numerous compounds, such as crinamine. Even though its mechanism of action is still unknown, crinamine was previously shown to possess anticancer activity. In this study, we demonstrate that crinamine was more cytotoxic to cervical cancer cells than normal cells. It also inhibited anchorage-independent tumor spheroid growth more effectively than existing chemotherapeutic drugs carboplatin and 5-fluorouracil or the CDK9 inhibitor FIT-039. Additionally, unlike cisplatin, crinamine induced apoptosis without promoting DNA double-strand breaks. It suppressed cervical cancer cell migration by inhibiting the expression of positive regulators of epithelial-mesenchymal transition SNAI1 and VIM. Importantly, crinamine also exerted anti-angiogenic activities by inhibiting secretion of VEGF-A protein in cervical cancer cells and blood vessel development in zebrafish embryos. Gene expression analysis revealed that its mechanism of action might be attributed, in part, to downregulation of cancer-related genes, such as AKT1, BCL2L1, CCND1, CDK4, PLK1, and RHOA. Our findings provide a first insight into crinamine’s anticancer activity, highlighting its potential use as an alternative bioactive compound for cervical cancer chemoprevention and therapy. Full article
(This article belongs to the Special Issue Antitumor Agents from Natural Sources)
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Open AccessArticle
Utilizing the Combination of Binding Kinetics and Micro-Pharmacokinetics Link in Vitro α-Glucosidase Inhibition to in Vivo Target Occupancy
Biomolecules 2019, 9(9), 493; https://doi.org/10.3390/biom9090493 - 16 Sep 2019
Viewed by 272
Abstract
Many compounds with good inhibitory activity (i.e., high affinity) within in vitro experiments failed in vivo studies due to a lack of efficacy from limited target occupancy (TO) in the drug discovery process. Recently, it was found that rate constants of the formation [...] Read more.
Many compounds with good inhibitory activity (i.e., high affinity) within in vitro experiments failed in vivo studies due to a lack of efficacy from limited target occupancy (TO) in the drug discovery process. Recently, it was found that rate constants of the formation and dissociation of the binary drug-target complex, rather than affinity, often govern in vivo efficacy. Therefore, the binding kinetics (BK) properties of compound-target interaction are emerging as a pivotal parameter. However, it is obvious that BK rate constants of the compound against target would not be directly linked to the in vivo TO unless the compound concentration in the target vicinity at any time point (TPK) can be evaluated. Here, we developed a novel simulation model to quantitate the dynamic change of target engagement over time in rat with a combined use of BK and TPK features of Epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) on the basis of α-glucosidase (AGH). Analysis of the results displayed that the percent of maximum AGH occupancies by the ECG were varied significantly from 48.9 to 95.3% and by the EGCG slightly from 96 to 99.8%; that the time course of above 70% engagement by ECG spanned a range from 0 to 0.64 h and by EGCG a range of 1.5 to 8.9 h in four different intestinal segments of the rat. It was clearly analyzed how each parameter in the simulation model effected on the in vivo the AGH engagement by ECG and EGCG. Our results provide a novel approach for assessing the potential inhibitory activity of the compounds against AGH. Full article
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Open AccessArticle
Discovery of Orexant and Anorexant Agents with Indazole Scaffold Endowed with Peripheral Antiedema Activity
Biomolecules 2019, 9(9), 492; https://doi.org/10.3390/biom9090492 - 16 Sep 2019
Viewed by 324
Abstract
The endocannabinoid system represents an integrated neuronal network involved in the control of several organisms’ functions, such as feeding behavior. A series of hybrids of 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (mimonabant), a well-known inverse agonist of the type-1 cannabinoid receptor (CB1), once used [...] Read more.
The endocannabinoid system represents an integrated neuronal network involved in the control of several organisms’ functions, such as feeding behavior. A series of hybrids of 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (mimonabant), a well-known inverse agonist of the type-1 cannabinoid receptor (CB1), once used as an antiobesity drug, and the N-(2S)-substitutes of 1-[(4-fluorophenyl)methyl]indazole-3-carboxamide with 1-amino-3-methyl-1-oxobutane (AB-Fubinaca), 1-amino-3,3-dimethyl-1-oxobutane (ADB-Fubinaca), and 3-methylbutanoate (AMB-Fubinaca), endowed with potent agonistic activity towards cannabinoid receptors CB1 and CB2 were in solution as C-terminal amides, acids, methyl esters and N-methyl amides. These compounds have been studied by binding assays to cannabinoid receptors and by functional receptor assays, using rat brain membranes in vitro. The most active among them as an agonist, (S)-1-(2,4-dichlorobenzyl)-N-(3,3-dimethyl-1-(methylamino)-1-oxobutan-2-yl)-1H-indazole-3-carboxamide (LONI11), and an antagonist, (S)-2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamido)-3-methylbutanoic acid (LONI4), were tested in vivo in mic, to evaluate their ability to stimulate or suppress feeding behavior after intraperitoneal (i.p.) administration. For a LONI11 formalin test and a tail flick test after an administration by the subcutaneous (s.c.) and intracerebroventricular (i.c.v.) routes, respectively, were also carried out in vivo in mice to investigate the antinociceptive property at the central and peripheral levesl. We observed a significant orexant effect for LONI11 and an intense anorexant effect for (S)-methyl 2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamido)-3,3-dimethylbutanoate (LONI2) and LONI4. In zymosan-induced edema and hyperalgesia, LONI11 reduced the percent of paw volume increase and paw latency after s.c. administration, also suggesting a possible peripheral anti-inflammatory activity. Full article
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Open AccessArticle
Loosening of Side-Chain Packing Associated with Perturbations in Peripheral Dynamics Induced by the D76N Mutation of β2-Microglobulin Revealed by Pressure-NMR and Molecular Dynamic Simulations
Biomolecules 2019, 9(9), 491; https://doi.org/10.3390/biom9090491 - 16 Sep 2019
Viewed by 267
Abstract
β2-Microglobulin (β2m) is the causative protein of dialysis-related amyloidosis, and its D76N variant is less stable and more prone to aggregation. Since their crystal structures are indistinguishable from each other, enhanced amyloidogenicity induced by the mutation may be attributed [...] Read more.
β2-Microglobulin (β2m) is the causative protein of dialysis-related amyloidosis, and its D76N variant is less stable and more prone to aggregation. Since their crystal structures are indistinguishable from each other, enhanced amyloidogenicity induced by the mutation may be attributed to changes in the structural dynamics of the molecule. We examined pressure and mutation effects on the β2m molecule by NMR and MD simulations, and found that the mutation induced the loosening of the inter-sheet packing of β2m, which is relevant to destabilization and subsequent amyloidogenicity. On the other hand, this loosening was coupled with perturbed dynamics at some peripheral regions. The key result for this conclusion was that both the mutation and pressure induced similar reductions in the mobility of these residues, suggesting that there is a common mechanism underlying the suppression of inherent fluctuations in the β2m molecule. Analyses of data obtained under high pressure conditions suggested that the network of dynamically correlated residues included not only the mutation site, but also distal residues, such as those of the C- and D-strands. Reductions in these local dynamics correlated with the loosening of inter-sheet packing. Full article
(This article belongs to the Section Molecular Structure and Dynamics)
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Open AccessArticle
Evolutionary Rate Heterogeneity and Functional Divergence of Orthologous Genes in Pyrus
Biomolecules 2019, 9(9), 490; https://doi.org/10.3390/biom9090490 - 16 Sep 2019
Viewed by 259
Abstract
Negatively selected genes (NSGs) and positively selected genes (PSGs) are the two types of most nuclear protein-coding genes in organisms. However, the evolutionary rates and characteristics of different types of genes have been rarely understood. In the present study, we investigate the rates [...] Read more.
Negatively selected genes (NSGs) and positively selected genes (PSGs) are the two types of most nuclear protein-coding genes in organisms. However, the evolutionary rates and characteristics of different types of genes have been rarely understood. In the present study, we investigate the rates of synonymous substitution (Ks) and the rates of non-synonymous substitution (Ka) by comparing the orthologous genes of two sequenced Pyrus species, Pyrus bretschneideri and Pyrus communis. Subsequently, we compared the evolutionary rates, gene structures, and expression profiles during different fruit development between PSGs and NSGs. Compared with the NSGs, the PSGs have fewer exons, shorter gene length, lower synonymous substitution rates and have higher evolutionary rates. Remarkably, gene expression patterns between two Pyrus species fruit indicated functional divergence for most of the orthologous genes derived from a common ancestor, and subfunctionalization for some of them. Overall, the present study shows that PSGs differs from NSGs not only under environmental selective pressure (Ka/Ks), but also in their structural, functional, and evolutionary properties. Additionally, our resulting data provides important insights for the evolution and highlights the diversification of orthologous genes in two Pyrus species. Full article
(This article belongs to the Section Bioinformatics and Systems Biology)
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Open AccessArticle
Detection and Identification of Allergens from Canadian Mustard Varieties of Sinapis alba and Brassica juncea
Biomolecules 2019, 9(9), 489; https://doi.org/10.3390/biom9090489 - 14 Sep 2019
Viewed by 243
Abstract
Currently, information on the allergens profiles of different mustard varieties is rather scarce. Therefore, the objective of this study was to assess protein profiles and immunoglobulin E (IgE)-binding patterns of selected Canadian mustard varieties. Optimization of a non-denaturing protein extraction from the seeds [...] Read more.
Currently, information on the allergens profiles of different mustard varieties is rather scarce. Therefore, the objective of this study was to assess protein profiles and immunoglobulin E (IgE)-binding patterns of selected Canadian mustard varieties. Optimization of a non-denaturing protein extraction from the seeds of selected mustard varieties was first undertaken, and the various extracts were quantitatively and qualitatively analyzed by means of protein recovery determination and protein profiling. The IgE-binding patterns of selected mustard seeds extracts were assessed by immunoblotting using sera from mustard sensitized and allergic individuals. In addition to the known mustard allergens—Sin a 2 (11S globulins), Sin a 1, and Bra j 1 (2S albumins)—the presence of other new IgE-binding protein bands was revealed from both Sinapis alba and Brassica juncea varieties. Mass spectrometry (MS) analysis of the in-gel digested IgE-reactive bands identified the unknown ones as being oleosin, β-glucosidase, enolase, and glutathione-S transferase proteins. A bioinformatic comparison of the amino acid sequence of the new IgE-binding mustard proteins with those of know allergens revealed a number of strong homologies that are highly relevant for potential allergic cross-reactivity. Moreover, it was found that Sin a 1, Bra j 1, and cruciferin polypeptides exhibited a stronger IgE reactivity under non-reducing conditions in comparison to reducing conditions, demonstrating the recognition of conformational epitopes. These results further support the utilization of non-denaturing extraction and analysis conditions, as denaturing conditions may lead to failure in the detection of important immunoreactive epitopes. Full article
(This article belongs to the Special Issue Advances on Allergens Identification and Characterization )
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Open AccessArticle
HDX and Native Mass Spectrometry Reveals the Different Structural Basis for Interaction of the Staphylococcal Pathogenicity Island Repressor Stl with Dimeric and Trimeric Phage dUTPases
Biomolecules 2019, 9(9), 488; https://doi.org/10.3390/biom9090488 - 14 Sep 2019
Viewed by 406
Abstract
The dUTPase enzyme family plays an essential role in maintaining the genome integrity and are represented by two distinct classes of proteins; the β-pleated homotrimeric and the all-α homodimeric dUTPases. Representatives of both trimeric and dimeric dUTPases are encoded by Staphylococcus aureus phage [...] Read more.
The dUTPase enzyme family plays an essential role in maintaining the genome integrity and are represented by two distinct classes of proteins; the β-pleated homotrimeric and the all-α homodimeric dUTPases. Representatives of both trimeric and dimeric dUTPases are encoded by Staphylococcus aureus phage genomes and have been shown to interact with the Stl repressor protein of S. aureus pathogenicity island SaPIbov1. In the present work we set out to characterize the interactions between these proteins based on a range of biochemical and biophysical methods and shed light on the binding mechanism of the dimeric φNM1 phage dUTPase and Stl. Using hydrogen deuterium exchange mass spectrometry, we also characterize the protein regions involved in the dUTPase:Stl interactions. Based on these results we provide reasonable explanation for the enzyme inhibitory effect of Stl observed in both types of complexes. Our experiments reveal that Stl employs different peptide segments and stoichiometry for the two different phage dUTPases which allows us to propose a functional plasticity of Stl. The malleable character of Stl serves as a basis for the inhibition of both dimeric and trimeric dUTPases. Full article
(This article belongs to the Section Biochemistry)
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Open AccessArticle
Origin of Carbon and Essential Fatty Acids in Higher Trophic Level Fish in Headwater Stream Food Webs
Biomolecules 2019, 9(9), 487; https://doi.org/10.3390/biom9090487 - 13 Sep 2019
Viewed by 320
Abstract
Dietary carbon sources in headwater stream food webs are divided into allochthonous and autochthonous organic matters. We hypothesized that: 1) the dietary allochthonous contribution for fish in headwater stream food webs positively relate with canopy cover; and 2) essential fatty acids originate from [...] Read more.
Dietary carbon sources in headwater stream food webs are divided into allochthonous and autochthonous organic matters. We hypothesized that: 1) the dietary allochthonous contribution for fish in headwater stream food webs positively relate with canopy cover; and 2) essential fatty acids originate from autochthonous organic matter regardless of canopy covers, because essential fatty acids, such as 20:5ω3 and 22:6ω3, are normally absent in allochthonous organic matters. We investigated predatory fish Salvelinus leucomaenis stomach contents in four headwater stream systems, which are located in subarctic region in northern Japan. In addition, stable carbon and nitrogen isotope ratios, fatty acid profile, and stable carbon isotope ratios of essential fatty acids were analyzed. Bulk stable carbon analysis showed the major contribution of autochthonous sources to assimilated carbon in S. leucomaenis. Surface baits in the stomach had intermediate stable carbon isotope ratios between autochthonous and allochthonous organic matter, indicating aquatic carbon was partly assimilated by surface baits. Stable carbon isotope ratios of essential fatty acids showed a positive relationship between autochthonous sources and S. leucomaenis across four study sites. This study demonstrated that the main supplier of dietary carbon and essential fatty acids was autochthonous organic matter even in headwater stream ecosystems under high canopy cover. Full article
(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)
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Open AccessArticle
Succinate Modulates Intestinal Barrier Function and Inflammation Response in Pigs
Biomolecules 2019, 9(9), 486; https://doi.org/10.3390/biom9090486 - 13 Sep 2019
Viewed by 381
Abstract
Succinate is a metabolic intermediate of the tricarboxylic acid (TCA) cycle in all aerobic organisms, and is also a vital microbial metabolite in the gut. Although succinate is known to regulate intestinal metabolism and immune function, its role in the protection of the [...] Read more.
Succinate is a metabolic intermediate of the tricarboxylic acid (TCA) cycle in all aerobic organisms, and is also a vital microbial metabolite in the gut. Although succinate is known to regulate intestinal metabolism and immune function, its role in the protection of the intestinal epithelial barrier function and inflammation is poorly characterized. In this study, we evaluated the effects of succinate on intestinal epithelial barrier function and inflammation in pigs. Twenty-four growing pigs were distributed into three groups (n = 8) and received either a basal diet (control group) or the same diet supplemented with 0.1% succinate or 1% succinate. The diet supplemented with 1% succinate led to alterations in the intestinal morphology. We confirmed in vitro that 5 mM succinate treatment modulated intestinal epithelial permeability by increased transepithelial electrical resistance (TEER) in intestinal porcine epithelial cell (IPEC)-J2 cells. Furthermore, succinate treatment increased the abundance of tight junction proteins claudin-1, zona occluden (ZO)-1, and ZO-2 in the jejunum in vivo and in vitro. In addition, dietary succinate supplementation promoted the expression of inflammatory cytokines interleukin (IL)-25, IL-10, IL-8, and IL-18 in the jejunum. Taken together, these data identify a novel role of succinate in the modulation of intestinal epithelial barrier function, which may be a nutritional target to improve gut health in animals. Full article
(This article belongs to the Section Natural and Bio-inspired Molecules)
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Open AccessReview
Long-chain Omega-3 Polyunsaturated Fatty Acids in Natural Ecosystems and the Human Diet: Assumptions and Challenges
Biomolecules 2019, 9(9), 485; https://doi.org/10.3390/biom9090485 - 12 Sep 2019
Viewed by 465
Abstract
Over the past three decades, studies of essential biomolecules, long-chain polyunsaturated fatty acids of the omega-3 family (LC-PUFAs), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have made considerable progress, resulting in several important assumptions. However, new data, which continue to [...] Read more.
Over the past three decades, studies of essential biomolecules, long-chain polyunsaturated fatty acids of the omega-3 family (LC-PUFAs), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have made considerable progress, resulting in several important assumptions. However, new data, which continue to appear, challenge these assumptions. Based on the current literature, an attempt is made to reconsider the following assumptions: 1. There are algal classes of high and low nutritive quality. 2. EPA and DHA decrease with increasing eutrophication in aquatic ecosystems. 3. Animals need EPA and DHA. 4. Fish are the main food source of EPA and DHA for humans. 5. Culinary treatment decreases EPA and DHA in products. As demonstrated, some of the above assumptions need to be substantially specified and changed. Full article
(This article belongs to the Special Issue Fatty Acids in Natural Ecosystems and Human Nutrition)
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Open AccessArticle
Insights into Ergosterol Peroxide’s Trypanocidal Activity
Biomolecules 2019, 9(9), 484; https://doi.org/10.3390/biom9090484 - 12 Sep 2019
Viewed by 324
Abstract
Trypanosoma cruzi, which causes Chagas disease, is a significant health threat in many countries and affects millions of people. Given the magnitude of this disease, a broader understanding of trypanocidal mechanisms is needed to prevent and treat infection. Natural endoperoxides, such as [...] Read more.
Trypanosoma cruzi, which causes Chagas disease, is a significant health threat in many countries and affects millions of people. Given the magnitude of this disease, a broader understanding of trypanocidal mechanisms is needed to prevent and treat infection. Natural endoperoxides, such as ergosterol peroxide, have been shown to be toxic to parasites without causing harm to human cells or tissues. Although prior studies have demonstrated the trypanocidal activity of ergosterol peroxide, the cellular and molecular mechanisms remain unknown. The results of this study indicate that a free-radical reaction occurs in T. cruzi following ergosterol peroxide exposure, leading to cell death. Using a combination of biochemical, microscopic and in silico experimental approaches, we have identified, for the first time, the cellular and molecular cytotoxic mechanism of an ergosterol peroxide obtained from Pleurotus ostreatus (Jacq) P. Kumm. f. sp. Florida. Full article
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Open AccessArticle
Identification of miRNAs and Their Target Genes Involved in Cucumber Fruit Expansion Using Small RNA and Degradome Sequencing
Biomolecules 2019, 9(9), 483; https://doi.org/10.3390/biom9090483 - 12 Sep 2019
Viewed by 274
Abstract
Fruit expansion is an essential and very complex biological process. Regulatory roles of microRNAs (miRNAs) and miRNA–mRNA modules in the cucumber fruit expansion are not yet to be investigated. In this work, 1253 known and 1269 novel miRNAs were identified from nine cucumber [...] Read more.
Fruit expansion is an essential and very complex biological process. Regulatory roles of microRNAs (miRNAs) and miRNA–mRNA modules in the cucumber fruit expansion are not yet to be investigated. In this work, 1253 known and 1269 novel miRNAs were identified from nine cucumber fruit small RNA (sRNA) libraries through high-throughput sequencing. A total of 105 highly differentially expressed miRNAs were recognized in the fruit on five days post anthesis with pollination (EXP_5d) sRNA library. Further, expression patterns of 11 differentially expressed miRNAs were validated by quantitative real-time PCR (qRT-PCR). The expression patterns were similar to sRNAs sequencing data. Transcripts of 1155 sequences were predicted as target genes of differentially expressed miRNAs by degradome sequencing. Gene Ontology (GO) enrichment showed that these target genes were involved in 24 biological processes, 15 cell components and nine molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that these target genes were significantly enriched in 19 pathways and the enriched KEGG pathways were associated with environmental adaptation, signal transduction and translation. Based on the functional prediction of miRNAs and target genes, our findings suggest that miRNAs have a potential regulatory role in cucumber fruit expansion by targeting their target genes, which provide important data for understanding the miRNA-mediated regulatory networks controlling fruit expansion in cucumber. Specific miRNAs could be selected for further functional research and molecular breeding in cucumber. Full article
(This article belongs to the Section Molecular Biology)
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Open AccessArticle
Quercetin Interrupts the Positive Feedback Loop Between STAT3 and IL-6, Promotes Autophagy, and Reduces ROS, Preventing EBV-Driven B Cell Immortalization
Biomolecules 2019, 9(9), 482; https://doi.org/10.3390/biom9090482 - 12 Sep 2019
Viewed by 313
Abstract
The oncogenic gammaherpesvirus Epstein–Barr virus (EBV) immortalizes in vitro B lymphocytes into lymphoblastoid cell lines (LCLs), a model that gives the opportunity to explore the molecular mechanisms driving viral tumorigenesis. In this study, we addressed the potential of quercetin, a widely distributed flavonoid [...] Read more.
The oncogenic gammaherpesvirus Epstein–Barr virus (EBV) immortalizes in vitro B lymphocytes into lymphoblastoid cell lines (LCLs), a model that gives the opportunity to explore the molecular mechanisms driving viral tumorigenesis. In this study, we addressed the potential of quercetin, a widely distributed flavonoid displaying antioxidant, anti-inflammatory, and anti-cancer properties, in preventing EBV-driven B cell immortalization. The results obtained indicated that quercetin inhibited thectivation of signal transducer and activator of transcription 3 (STAT3) induced by EBV infection and reduced molecules such as interleukin-6 (IL-6) and reactive oxidative species (ROS) known to be essential for the immortalization process. Moreover, we found that quercetin promoted autophagy and counteracted the accumulation of sequestosome1/p62 (SQSTM1/p62), ultimately leading to the prevention of B cell immortalization. These findings suggest that quercetin may have the potential to be used to counteract EBV-driven lymphomagenesis, especially if its stability is improved. Full article
(This article belongs to the Special Issue Antitumor Agents from Natural Sources)
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Open AccessArticle
Sulfated Glycoaminoglycans and Proteoglycan Syndecan-4 Are Involved in Membrane Fixation of LL-37 and Its Pro-Migratory Effect in Breast Cancer Cells
Biomolecules 2019, 9(9), 481; https://doi.org/10.3390/biom9090481 - 12 Sep 2019
Viewed by 289
Abstract
Initially characterized by its antimicrobial activities, LL-37 has also been shown to significantly contribute to tumor development. On breast cancer cell lines, LL-37 increases intracellular calcium via the TRPV2 channel and their migration via the activation of PI3K/AKT signaling. Its all-d enantiomer [...] Read more.
Initially characterized by its antimicrobial activities, LL-37 has also been shown to significantly contribute to tumor development. On breast cancer cell lines, LL-37 increases intracellular calcium via the TRPV2 channel and their migration via the activation of PI3K/AKT signaling. Its all-d enantiomer d-LL-37 induces similar effects, which excludes a protein-protein interaction of LL-37 in a classic ligand-receptor manner. Its net charge of +6 gave rise to the hypothesis that the peptide uses the negative charges of sulfoglycans or sialic acids to facilitate its attachment to the cell membrane and to induce its activities. Whereas several vegetal lectins, specifically attaching to sialylated or sulfated structures, blocked the activities of LL-37 on both calcium increase and cell migration, several sialidases had no effect. However, the competitive use of free sulfated glycoaminoglycans (GAGs) as chrondroitin and heparin, or treatment of the cell surface with chondroitinase and heparinase resulted in an activity loss of 50–100% for LL-37. Concordant results were obtained by blocking the synthesis of GAGs with 4-Methylumbelliferyl-β-d-xyloside, and by suppression of glycan sulfatation by sodium chlorate. Using a candidate approach by suppressing proteoglycan synthesis using RNA interference, syndecan-4 was shown to be required for the activities of LL-37 and its binding to the cell surface. This leads to the conclusion that syndecan-4, by means of sulfated GAGs, could act as a receptor for LL-37. Full article
(This article belongs to the Special Issue Structure and Function of Antimicrobial Peptides)
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Open AccessArticle
Large-Scale Production of Bioactive Terrein by Aspergillus terreus Strain S020 Isolated from the Saudi Coast of the Red Sea
Biomolecules 2019, 9(9), 480; https://doi.org/10.3390/biom9090480 - 12 Sep 2019
Viewed by 255
Abstract
The diversity of symbiotic fungi derived from two marine sponges and sediment collected off Obhur, Jeddah (Saudi Arabia), was investigated in the current study. A total of 23 isolates were purified using a culture-dependent approach. Using the morphological properties combined with internal transcribed [...] Read more.
The diversity of symbiotic fungi derived from two marine sponges and sediment collected off Obhur, Jeddah (Saudi Arabia), was investigated in the current study. A total of 23 isolates were purified using a culture-dependent approach. Using the morphological properties combined with internal transcribed spacer-rDNA (ITS-rDNA) sequences, 23 fungal strains (in the majority Penicillium and Aspergillus) were identified from these samples. The biological screening (cytotoxic and antimicrobial activities) of small-scale cultures of these fungi yielded several target fungal strains which produced bioactive secondary metabolites. Amongst these isolates, the crude extract of Aspergillus terreus strain S020, which was cultured in fermentation static broth, 21 L, for 40 days at room temperature on potato dextrose broth, displayed strong antimicrobial activities against Pseudomonas aeruginosa and Staphylococcus aureus and significant antiproliferative effects on human carcinoma cells. Chromatographic separation of the crude extract by silica gel column chromatography indicated that the S020 isolate could produce a series of chemical compounds. Among these, pure crystalline terrein was separated with a high yield of 537.26 ± 23.42 g/kg extract, which represents the highest fermentation production of terrein to date. Its chemical structure was elucidated on the basis of high-resolution electrospray ionization mass spectrometry (HRESIMS) or high-resolution mass spectrometry (HRMS), 1D, and 2D NMR spectroscopic analyses and by comparison with reported data. The compound showed strong cytotoxic activity against colorectal carcinoma cells (HCT-116) and hepatocellular carcinoma cells (HepG2), with IC50 values of 12.13 and 22.53 µM, respectively. Our study highlights the potential of A. terreus strain S020 for the industrial production of bioactive terrein on a large scale and the importance of future investigations of these strains to identify the bioactive leads in these fungal extracts. Full article
(This article belongs to the Section Natural and Bio-inspired Molecules)
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Open AccessArticle
Protective Effects of Sesamin against UVB-Induced Skin Inflammation and Photodamage In Vitro and In Vivo
Biomolecules 2019, 9(9), 479; https://doi.org/10.3390/biom9090479 - 12 Sep 2019
Viewed by 295
Abstract
Ultraviolet (UV) exposure has been demonstrated as the most critical factor causing extrinsic skin aging and inflammation. This study explored the protective effects and mechanisms of sesamin against skin photodamage. Sesamin reduced intracellular reactive oxygen species production after UVB irradiation in human dermal [...] Read more.
Ultraviolet (UV) exposure has been demonstrated as the most critical factor causing extrinsic skin aging and inflammation. This study explored the protective effects and mechanisms of sesamin against skin photodamage. Sesamin reduced intracellular reactive oxygen species production after UVB irradiation in human dermal fibroblasts. The sesamin treatment attenuated mitogen-activated protein (MAP) kinase phosphorylation and matrix metalloproteinase (MMPs) overexpression induced by UVB exposure, and it significantly enhanced the tissue inhibitor of metalloproteinase-1 protein expression. Sesamin also elevated the total collagen content in human fibroblasts by inhibiting UVB-induced mothers against decapentaplegic homolog 7 (Smad7) protein expression. Sesamin reduced UVB-induced inducible nitric oxide synthase (i-NOS) and cyclooxygenase-2 (COX-2) overexpression and inhibited nuclear factor-kappa B (NF-κB) translocation. Moreover, sesamin may regulate the c-Jun N-terminal kinases (JNK) and p38 MAP kinase pathways, which inhibit COX-2 expression. Sesamin could reduce UVB-induced inflammation, epidermal hyperplasia, collagen degradation, and wrinkle formation in hairless mice. It also reduced MMP-1, interleukin (IL-1), i-NOS, and NF-κB in the mouse skin. These results demonstrate that sesamin had antiphotodamage and anti-inflammatory activities. Sesamin has potential for use as a skin protection agent in antiphotodamage and skin care products. Full article
(This article belongs to the Special Issue Oxidative Damage on Biomolecules and Antioxidants)
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