Search Results (7,491)

Background: Survivin is an anti-apoptotic protein highly expressed during embryonic development and, in adults, mainly in the gastrointestinal epithelium. Its levels decrease in human gastric tissue and cultured cells upon exposure to Helicobacter pylori gamma-glutamyl transpeptidase (GGT), though the underlying mechanism remains unclear. Objective: We aimed to investigate the role of cap-independent translation driven by the Survivin 5′ untranslated region (5′UTR) in response to H. pylori infection in vitro. Methodology: Human cell lines (AGS, GES-1, HeLa, HEK293T) were used alongside bicistronic and monocistronic (Firefly/Renilla luciferases) reporter assays to assess short and long variants of the Survivin 5′UTR and HIV-1 internal ribosome entry site (IRES) sequences. Additional methods included in vitro transcription/translation, RT-qPCR, agarose gel electrophoresis, Western blotting, coupled/uncoupled translation assays, and siRNA silencing. Results: The short variant of the Survivin 5′ UTR supported cap-independent translation, like the HIV-1 IRES. Notably, H. pylori infection suppressed this translation in a GGT-dependent manner in gastric cells, and a similar reduction was observed following treatment with ATO, a known prooxidant. Conclusion: The Survivin 5′UTR exhibits cap-independent translation activity that is inhibited by H. pylori in a GGT-dependent manner, likely via oxidative stress. This mechanism helps to explain the downregulation of Survivin during gastric infection and indicates that oxidative stress can negatively affect both cellular and viral IRES-mediated translation. Full article

Objective: To investigate the mechanism by which sphingosine-1-phosphatase 2 (SGPP2) modulates endoplasmic reticulum stress (ERS) through the SIRT1/AMPK pathway to improve ischemic cardiomyopathy-induced chronic heart failure (IHF). Methods: Key genes of IHF and ERS were identified through bioinformatics analysis, and significantly associated pathways of the key genes were obtained via single-gene enrichment analysis. In vivo, IHF was induced in Sprague–Dawley (male) rats via ligation of the left anterior descending coronary artery, with cardiac function examined through echocardiography. Myocardial tissue injury and fibrosis were evaluated utilizing hematoxylin-eosin, Masson, and TUNEL staining. Serum levels of NT-proBNP and cTnT were measured via ELISA. SGPP2 protein expression was assessed via immunohistochemistry and Western blotting (WB). In vitro, neonatal rat cardiomyocytes (NRCMs) were isolated and underwent oxygen-glucose deprivation (OGD) to establish an IHF model. SGPP2-overexpressing NRCMs were constructed and treated with the ERS inducer tunicamycin (Tu) or the SIRT1 inhibitor EX527. Cell injury was evaluated using Cell Counting Kit-8 and lactate dehydrogenase release assays, as well as flow cytometry. Endoplasmic reticulum structure was examined by transmission electron microscopy. The endoplasmic reticulum was labeled with the ER-Tracker Red molecular probe. WB was utilized to detect the expression of apoptosis- and ERS-linked proteins, and the activity of the SIRT1/AMPK signaling pathway. Results: Six key genes (CTSK, FURIN, SLC2A1, RSAD2, SGPP2, and STAT3) were identified through bioinformatics analysis, with SGPP2 showing the most significant differential expression. Additionally, SGPP2 was found to be downregulated in IHF. Single-gene enrichment analysis showed that SGPP2 exhibited a significant association with the AMPK signaling pathway. Animal experiments demonstrated that rats with IHF exhibited significantly impaired cardiac function, marked myocardial tissue injury and fibrosis, ERS in myocardial tissue, lowered SGPP2 expression, and decreased SIRT1/AMPK signaling pathway activity. In vitro experiments confirmed that SGPP2 overexpression alleviated OGD-induced cardiomyocyte injury by inhibiting ERS and simultaneously activating the SIRT1/AMPK signaling pathway. Rescue experiments further demonstrated that both Tu and EX527 significantly promoted ERS and cellular injury, thereby counteracting the protective effects of SGPP2. Conclusions: SGPP2 alleviates IHF by inhibiting ERS modulated by the SIRT1/AMPK pathway. Full article

Background/Objectives. Lactiplantibacillus plantarum CRL681 has previously demonstrated a strong antagonistic effect against Escherichia coli O157:H7 in food matrices; however, the molecular mechanisms underlying this activity remain poorly understood. Since initial interactions between beneficial bacteria and pathogens occur mainly at the cell surface and in the extracellular environment, the characterization of the bacterial secretome is essential for elucidating these mechanisms. In this study, the secretome of L. plantarum CRL681 was comprehensively characterized using an integrated in silico and in vitro approach. Methods. The exoproteome and surfaceome were analyzed by LC-MS/MS under pure culture conditions and during co-culture with E. coli O157:H7. Identified proteins were functionally annotated, classified according to subcellular localization and secretion pathways, and evaluated through protein–protein interaction network analysis. Results. A total of 275 proteins were proposed as components of the CRL681 secretome, including proteins involved in cell surface remodeling, metabolism and nutrient transport, stress response, adhesion, and genetic information processing. Co-culture with EHEC induced significant changes in the expression of proteins associated with energy metabolism, transport systems, and redox homeostasis, indicating a metabolic and physiological adaptation of L. plantarum CRL681 under competitive conditions. Notably, several peptidoglycan hydrolases, ribosomal proteins with reported antimicrobial activity, and moonlighting proteins related to adhesion were identified. Conclusions. Overall, these findings suggest that the antagonistic activity of L. plantarum CRL681 against E. coli O157:H7 would be mediated by synergistic mechanisms involving metabolic adaptation, stress resistance, surface adhesion, and the production of non-bacteriocin antimicrobial proteins, supporting its potential application as a bioprotective and functional probiotic strain. Full article

Secreted frizzled-related protein 3 (sFRP3/FRZB) is a soluble Wnt antagonist with established roles in skeletal development, however, its specific function in myogenesis remains underexplored. This study investigated the regulatory role of FRZB in muscle development, hypothesizing that it contributes to breed-specific growth differences in pigs. We examined FRZB expression in fetal tissues of slow-growing (Tibetan and Wujin) and fast-growing (Large White) pigs, and assessed its function in C2C12 myoblasts via siRNA-mediated knockdown. FRZB was widely expressed across porcine fetal tissues, with significantly higher abundance in the longissimus dorsi of slow-growing breeds. In vitro, FRZB silencing significantly enhanced myoblast proliferation and migration. Furthermore, knockdown accelerated differentiation and promoted the formation of longer, thicker multinucleated myotubes, accompanied by the upregulation of myogenic (MyoD, MyoG, MyHC) and fusion (β1-integrin, Myomaker) markers. Transcriptional profiling revealed a shift toward hypertrophy (Fst and Nog upregulation) and away from atrophy (Atrogin1 downregulation). These findings identify FRZB as a negative regulator of myogenesis via the Wnt signaling pathway. The elevated expression in indigenous breeds suggests FRZB may impose a molecular constraint on muscle development, highlighting its potential as a candidate gene for regulating carcass traits. Full article

The Repulsive Guidance Molecule a (RGMa) is a multifunctional GPI-anchored protein localized in the sarcolemma and sarcoplasm of the adult skeletal muscle cell. Our research group showed that RGMa overexpression can promote myoblast fusion and induce hypertrophic muscle fibers during in vitro differentiation. Here, we report that RGMa is expressed in primary skeletal muscle cells cultured in vitro, showing a nuclear localization, revealed by immunostaining with an antibody targeting its C-terminal region (C-RGMa). While RGMa was detected in the nuclei, its canonical receptor, Neogenin, was predominantly found in the perinuclear region. Nuclear RGMa was absent in Neogenin-knockdown cells, suggesting that Neogenin mediates its nuclear transport. Functional assays suggested that RGMa promotes primary skeletal muscle cell viability and proliferation and supports their myogenic commitment. These findings reveal a previously unrecognized nuclear function of RGMa–Neogenin signaling and provide new insights into the regulation of skeletal muscle cell behavior in vitro. Full article

The emergence of SARS-CoV-2, the etiological agent of COVID-19, has resulted in widespread global infection and millions of deaths. Viral entry is initiated by the interaction between the viral spike (S) protein and the host cell receptor ACE2, followed by TMPRSS2-mediated proteolytic activation that facilitates membrane fusion. Bitter melon (Momordica charantia L., MC), a traditional medicinal and edible plant widely used in tropical Asia, possesses notable anti-inflammatory, antioxidant, antitumor, and hypoglycemic properties. In this study, the ethanol extract of bitter melon (EMC) markedly downregulated ACE2 and TMPRSS2 expression in both in vitro and in vivo models without inducing cytotoxicity. Furthermore, phytochemicals isolated from EMC—including p-coumaric acid, rutin, and quercetin—exhibited comparable inhibitory effects. These results indicate that EMC and its bioactive constituents may interfere with SARS-CoV-2 entry by modulating the ACE2/TMPRSS2 axis, highlighting their potential as natural adjuncts for COVID-19 prevention or management. Full article

Background: Saffron (Crocus sativus L.) corms, often discarded as agricultural by-products, are a promising and sustainable source of bioactive metabolites with potential therapeutic relevance. However, their anticancer potential remains largely underinvestigated. Objectives: This study aimed to compare the phytochemical composition of hydroethanolic extracts from fresh (HEEF) and stored (HEES) saffron corms and to evaluate their anticancer effectiveness against colorectal cancer cells. Methods: Phytochemical profiling was performed using HPLC-ESI-QTOF-MS/MS. Cytotoxicity against T84 and SW480 colorectal cancer cell lines was determined by the crystal violet assay. Apoptosis-related protein modulation was assessed by Western blotting. Additionally, molecular docking, molecular dynamics simulations, and MM/GBSA calculations were used to investigate ligand–target binding affinities and stability. Results: Both extracts contained diverse primary and secondary metabolites, including phenolic acids, flavonoids, triterpenoids, lignans, anthraquinones, carotenoids, sugars, and fatty acids. HEES showed higher relative abundance of key bioactive metabolites than HEEF, which was enriched mainly in primary metabolites. HEES showed significantly greater dose-dependent cytotoxicity, particularly against SW480 cells after 24 h (IC₅₀ = 34.85 ± 3.35). Apoptosis induction was confirmed through increased expression of caspase-9 and p53 in T84 cells. In silico studies revealed strong and stable interactions of major metabolites, especially 3,8-dihydroxy-1-methylanthraquinone-2-carboxylic acid with COX2 and crocetin with VEGFR2. Conclusions: Stored saffron corms possess a richer bioactive profile and show enhanced anticancer effects in vitro compared with fresh saffron corms, suggesting that they may represent a promising source of compounds for the future development of colorectal cancer therapeutics. Full article

Lentiviral transduction remains the gold standard in adoptive modified cellular therapy, such as CAR-T; however, genome integration is not always desirable, such as when treating non-fatal autoimmune disease or for additional editing steps using CRISPR to produce allogeneic CAR-modified cells. Delivering in vitro-transcribed (IVT) mRNA represents an alternative solution but the labile nature of mRNA has led to efforts to improve half-life and translation efficiencies using a range of approaches including chemical and structural modifications. In this study, we explore the role of N⁶–methyladenosine (m6A) in a CD19-CAR sequence when delivered to T cells as an IVT mRNA. In silico analysis predicted the presence of four m6A consensus (DRACH) motifs in the CAR coding sequence and treating T cells with an inhibitor of the m6A methyltransferase (METTL3) resulted in a significant reduction in CAR protein expression. RNA analysis confirmed m6A bases at three of the predicted sites, indicating that the modification occurs independently of nuclear transcription. Synonymous mutation of the DRACH sites reduced the levels of CAR protein from 15 to >50% depending on the T cell donor. We also tested a panel of CAR transcripts with different UTRs, some containing m6A consensus motifs, and identified those which further improved protein expression. Furthermore, we found that the methylation of consensus m6A sites seems to be somewhat sequence-context-dependent. These findings demonstrate the importance of the m6A modification in stabilising and enhancing expression from IVT-derived mRNA and that this occurs within the cell, meaning targeted in vitro chemical modification during mRNA manufacturing may not be necessary. Full article

Tremella mesenterica, commonly known as the yellow brain or golden jelly fungus, has been traditionally used for its medicinal properties. In this study, we elucidated the structural characteristics of T. mesenterica polysaccharide (TMP) and evaluated its potential moisturizing mechanism in vitro, comparing it to Tremella fuciformis polysaccharide (TFP) and hyaluronic acid (HA). TMP was isolated through enzyme assisted extraction and it has a molecular weight (MW) of approximately 143 kDa. We investigated the composition of mannose, xylose, glucuronic acid, and glucose as a ratio of 59.8 ± 0.3, 24.0 ± 1.2, 11.0 ± 0.8, 5.2 ± 0.0, respectively. Through methylation and GC-MS analysis, we discovered TMP was composed of a main chain of β-(1→3)-linked mannopyranoside, substituted with various side chains such as xylopyranoside, glucuronopyranoside, glucopyranoside at the C-2 or C-4 positions of the backbone. TMP upregulated the expression of key moisturizing-related factors compared to TFP and HA, such as aquaporin-3 (AQP3) with 55% and 57% at 25 and 50 μg/mL and hyaluronic acid synthase-2 (HAS2) with 22% at 25 μg/mL, as confirmed through qRT-PCR analysis. Additionally, TMP significantly enhanced the expression of filaggrin (FLG), a critical protein involved in skin barrier function, with 22% at 25 μg/mL. Immunocytochemistry (ICC) analysis further revealed that TMP achieved the highest improvement in hyaluronic acid synthase-3 (HAS3) protein levels by 475% at 50 μg/mL. While further in vivo studies are required to substantiate its functional moisturizing efficacy, these findings suggest that TMP serves as a promising moisturizing agent. The structural and functional properties of TMP provide a potential foundation for its application in diverse industries, including cosmetics, food, biopolymers, and pharmaceuticals. Full article

Although calpain-5/CAPN5 is widely expressed in mammals, little is known regarding its functions. Pathogenic mutations of CAPN5 are causal for a devastating autoimmune eye disease, neovascular inflammatory vitreoretinopathy (NIV). To provide insight into both the physiological and pathological roles of CAPN5, it is essential to identify candidate interaction partners and possible substrates. Human SH-SY5Y neuroblastoma cells, transfected with full-length catalytically dead (Cys81Ala) CAPN5-3×FLAG, were used for anti-FLAG co-immunoprecipitation (co-IP) and quantitative proteomics using Sequential Window Acquisition of all THeoretical mass spectra (SWATH-MS). Fifty-one proteins were enriched at least four-fold, p < 0.01, relative to cells transfected with an empty FLAG vector. A high proportion (24/51) of candidate CAPN5 interaction partners are associated with protein quality control, including components of the chaperonin, chaperone, and ubiquitin–proteasome systems. Additional candidate interactors include tubulins, kinases, phosphatases, G proteins, and mitochondrial proteins. CAPN5 interactions for 14 of the candidate proteins were confirmed by co-IP and immunoblotting. Of these 14 proteins, 11 exhibited in vitro calcium-induced proteolysis following co-IP with WT CAPN5-3×FLAG. Impaired calcium-induced proteolysis of co-IP proteins was observed for the pathogenic CAPN5 variants R243L and R289W. Further studies are needed to validate the association of candidate CAPN5 interactors with proteins and complexes suggested by the SWATH-MS and co-IP results, and the possible role of CAPN5 within such complexes. The possible involvement of CAPN5 in protein quality control is relevant to NIV, as defects in protein quality control have been implicated in inherited retinal disorders. Proteomic data are available via ProteomeXchange with identifier PXD068008. Full article

The SARS-CoV-2 nucleocapsid protein (Np) is essential for viral RNA replication and genomic RNA packaging. Phosphorylation of Np within its central Ser-Arg-rich (SRR) linker is proposed to modulate these functions. To gain mechanistic insights into these distinct roles, we performed in vitro biophysical and biochemical studies using recombinantly expressed ancestral Np and phosphomimetic SRR variants. Limited-proteolysis showed minor cleavage differences between wild-type (WT) and phosphomimetic Np, but no major structure or stability changes in the N- and C-terminal domains were observed by circular dichroism spectroscopy and differential scanning fluorimetry, respectively. Mass photometry (MP) revealed that WT Np dimerized more readily than phosphomimetic variants. Crosslinking-MP showed that WT Np formed discrete complexes on viral 5′ UTR stem-loop (SL) 5 RNA, whereas phosphomimetic Np assembled preferentially on SL1–4. WT Np bound non-specifically to all RNAs tested primarily via hydrophobic interactions, whereas phosphomimetic Np showed selectivity for SARS-CoV-2-derived RNAs despite binding more electrostatically. A major difference was observed in the binding kinetics; WT Np compacted and irreversibly bound single-stranded DNA, whereas phosphomimetic Np displayed reduced compaction and fast on/off binding kinetics. These mechanistic insights support a model where phosphorylated Np functions in RNA replication and chaperoning, while non-phosphorylated Np facilitates genomic RNA packaging. The findings also help to explain infectivity differences and clinical outcomes associated with SRR linker variants. Full article

Background/Objectives: Lung adenocarcinoma (LUAD), the predominant subtype of non-small cell lung cancer (NSCLC), is frequently diagnosed at advanced stages with distant metastasis, underscoring the need for effective prognostic biomarkers. Fibroblast growth factor 2 (FGF2), a multifunctional regulator, has shown to play contradictory roles in cancer progression. Methods: We analyzed three independent Gene Expression Omnibus (GEO) datasets (GSE19804, GSE18842, and GSE19188) to identify consistently dysregulated genes in LUAD. Functional enrichment (GO, KEGG, and cancer hallmark analysis), protein–protein interaction (PPI) network construction, and hub gene prioritization were performed using public bioinformatic tools. Survival analyses were conducted via the Kaplan–Meier Plotter. The expression of FGF2 was validated across multiple platforms, including TCGA, CPTAC, TNMplot, LCE, and the Human Protein Atlas. Functional assays (Transwell migration and wound healing) demonstrated that exogenous FGF2 significantly suppressed LUAD cell motility in vitro. Results: A total of 949 differentially expressed genes (DEGs) were commonly identified across datasets, with enrichment in cell adhesion and metastasis-related pathways. Among the 11 hub genes identified, FGF2 was consistently downregulated in LUAD tissues across all datasets and stages. Higher FGF2 expression was associated with longer overall and progression-free survival. In vitro, FGF2 treatment significantly suppressed the migration and wound healing abilities of LUAD cell lines. Conclusions: FGF2 is downregulated in LUAD and inversely associated with metastatic progression and poor prognosis. The observed reduction in cancer cell motility upon FGF2 treatment in vitro, together with its expression pattern, supports a potential tumor-suppressive role and suggests that FGF2 may serve as a candidate non-invasive biomarker for monitoring LUAD metastasis. Full article

Activation of hepatic stellate cells (HSCs) featuring upregulated expression of α-smooth muscle actin (α-SMA) is recognized as a key driver for hepatic fibrosis, which provides a promising strategy for seeking anti-liver fibrogenic agents via suppressing the activation event. In this study, we designed and synthesized twenty-eight cordycepin derivatives through structural modifications at the C2 position and the C6-NH₂ group of the purine moiety. These compounds were screened for their inhibitory effects on HSC activation by detecting the mRNA expression of α-SMA using quantitative real-time polymerase chain reaction (qPCR) in the LX-2 cell model. Most compounds displayed inhibitory activity comparable to cordycepin, with compound 3a bearing a C2-chloro and a N6-methyl-N6-(2-chlorobenzyl) substituent, demonstrating enhanced in vitro anti-fibrotic effect. This compound was able to dose-dependently downregulate α-SMA and collagen-I at both mRNA and protein levels, inhibited LX-2 cell migration, and exhibited improved metabolic stability in liver microsomes. The Western blotting result also indicated that 3a could activate the AMPK signaling pathway. Overall, these results suggest 3a may serve as a lead compound for further investigation. Full article

Objectives: Adenoviruses (Ads) are among the most used vectors for gene therapy; human Ad serotype 5-derived (HuAd5) vectors are the most frequently used for gene transfer applications. However, Ad5 infection is endemic in humans, and 20% of the Western population has neutralizing antibodies (nAbs). Pre-existing immunity against HuAd5 represents a major issue for many gene therapy applications. In our study, we evaluated several Ad serotypes derived from chimpanzees (ChAds) in vitro and in vivo to assess their transduction efficiency in various cell types and tissues. We aimed at identifying Ad serotypes able either to transduce “challenging” cell types or to represent a possible alternative to Ad5-derived vectors with comparable infectivity and tropism. Methods: We evaluated the efficacy of transduction of twelve ChAds vectors expressing enhanced green fluorescent protein (EGFP) in human embryonic kidney cells, as well as human leukemic and human mesenchymal stem cells, using flow cytometry to determine the percentage of EGFP-expressing cells and their mean fluorescent intensity (MFI). We observed the highest transduction efficiency in the serotype CV1 ChAd; therefore, we proceeded to evaluate toxicity and biodistribution in vivo. Results: After in vitro evaluation of twelve ChAds serotypes, we observed that the CV1 serotype was the most efficient in transducing both leukemia cell lines (HL-60 and NB-4) and human mesenchymal stem cells. Furthermore, in vivo analysis of the CV1 serotype induced an inflammatory reaction similar to what was observed after HuAd5 administration. Conclusions: ChAds vectors represent an effective alternative for the transduction of cells resistant to HuAd5 infection, such as mesenchymal stem cells and leukemic cells. In addition, we observed that the CV1 ChAd serotype presented a transduction profile similar to HuAd5 in vitro and induced a similar inflammatory response in vivo; therefore, CV1 ChAd-derived vectors represent an interesting alternative for gene therapy applications. Full article

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive T-cell malignancy caused by persistent infection with human T-cell leukemia virus type 1 (HTLV-1). ATLL remains difficult to treat despite intensive chemotherapy, antiviral therapy, and hematopoietic stem cell transplantation. The limited durability of current treatment strategies highlights the need for mechanism-based therapeutic approaches. Protein arginine methyltransferase 5 (PRMT5) is a type II arginine methyltransferase that regulates transcription, RNA splicing, DNA damage responses, and immune signaling through symmetric dimethylation of histone and non-histone substrates. PRMT5 is frequently overexpressed across hematologic and solid tumors. Preclinical studies indicate that PRMT5 expression is elevated during HTLV-1-mediated T-cell transformation and that pharmacologic inhibition of PRMT5 selectively impairs the survival and transformation of infected T cells in vitro and in vivo. In this review, we highlight the current understanding of PRMT5 biology in cancer, summarize preclinical studies supporting PRMT5 as a therapeutic target in ATLL, and discuss key challenges to future clinical translation. We also discuss emerging approaches such as rational combination therapies and tumor-selective PRMT5 inhibitors as potential paths toward treatment for ATLL. Full article