Search Results (90)

Epigenetics garnered significant scientific interest in recent decades, with histone acetylation emerging as the most prevalent epigenetic deregulation process observed in malignancies. The clinical application of histone deacetylase (HDAC) inhibitors faced challenges, including complex therapeutic mechanisms and inconsistent treatment outcomes. In Acute Lymphoblastic Leukemia (ALL), the dysregulation of HDAC activity presents a promising therapeutic target. To investigate cellular-level tumor suppression by HDAC inhibitors possessing potent target engagement, we developed two novel azetidine-hydroxamic acid conjugates. Compared to N-hydroxy-4-((quinolin-4-ylamino)methyl)benzamide (NBU-1), N-hydroxy-6-((5-methyl-4-nitro-9-oxo-9,10-dihydroacridin-1-yl)amino)hexanamide (NBU-2) demonstrated enhanced inhibitory activity against HDAC1 (class I) and HDAC6 (class II) with IC₅₀ values of 7.75 nM and 7.34 nM, respectively, consistent with binding mode analysis and docking energy calculations. In vitro evaluation across 12 tumor cell lines revealed NBU-2’s potent antiproliferative effects, particularly against the ALL-derived Jurkat cells (IC₅₀ = 0.86 μM). Subsequent mechanistic studies were therefore conducted in this ALL model. Proteomic profiling indicated its potential involvement in modulating AKT signaling and histone modification pathways in Jurkat cells. Mechanistic investigations demonstrated that NBU-2 elevated histone acetylation while suppressing AKT phosphorylation. This compound altered apoptotic regulators by downregulating Bcl-2 and Bcl-XL expression while upregulating BAX, ultimately activating Caspase-9 and Caspase-3 to induce apoptosis. Cell cycle analysis revealed NBU-2-mediated G0/G1 arrest through reduced expression of Cyclin D1 and CDK4, diminished Rb protein phosphorylation, and increased p21 expression. These findings propose a strategic framework for developing next-generation HDAC inhibitors for ALL treatment and elucidating their mechanism-specific anti-cancer actions. Full article

Background/Objectives: Here, we report the design, synthesis, and in vitro biological evaluation of a novel stimuli-sensitive nanotherapeutics based on cisplatin analog, cis-[PtCl₂(NH₃)(2-(3-oxobutyl)pyridine)] (Pt-OBP), covalently linked to a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer via a pH-sensitive hydrazone bond. Methods: Two polymer–drug conjugates, P-Pt-A and P-Pt-B, were synthesized, differing in spacer length between the polymer chain and hydrazone bond, which in turn modulates their drug release kinetics. Results: The spacer based on hydrazone bond demonstrated satisfactory stability under blood-mimicking conditions while enabling selective release of the active drug intracellularly or even in the mildly acidic tumor microenvironment. Pt-OBP exhibits comparable or even superior cytostatic and cytotoxic activity to carboplatin across a panel of murine and human cancer cell lines, with the highest potency observed in FaDu cells representing human head and neck squamous cell carcinoma. Mechanistically, Pt-OBP induced significant phosphorylation of γ-H2AX and activation of caspase-3, indicating its ability to cause DNA damage with subsequent apoptosis induction. P-Pt-A retained moderate biological activity, whereas the slower-releasing P-Pt-B exhibited reduced potency in vitro, consistent with its drug release profile. Conclusions: Notably, free Pt-OBP induced rapid apoptotic cell death, surpassing carboplatin at early time points, and the polymeric conjugates achieved comparable pro-apoptotic activity after extended incubation, suggesting effective intracellular release of the active drug. Full article

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies due to late diagnosis, poor drug penetration, and intrinsic chemoresistance. Targeted delivery strategies are urgently needed to enhance therapeutic precision while minimizing systemic toxicity. Here, we developed an AS1411 aptamer-functionalized liposomal platform encapsulating siRNA against metastasis-associated protein 2 (MTA2), a chromatin remodeling factor that suppresses the tumor suppressor PTEN and activates PI3K/AKT signaling. The AS1411 aptamer, which binds nucleolin overexpressed on PDAC cells, was conjugated to cationic liposomes via copper-free click chemistry. The resulting AS1411-Lipm[siRNA] exhibited high siRNA encapsulation efficiency, selective uptake by nucleolin-positive PDAC cells, and enhanced endosomal escape. Treatment of MIA PaCa-2 cells with AS1411-Lipm[siRNA] significantly reduced MTA2 expression by ~60%, substantially restored PTEN, and inhibited AKT phosphorylation by ~50%, leading to decreased cell viability, impaired migration by ~75%, and increased apoptosis by ~35%, while sparing nucleolin-negative cells. These findings highlight AS1411-Lipm[siRNA] as a promising platform for selective siRNA delivery and potent molecular inhibition in PDAC therapy. Full article

Drug resistance remains a critical barrier to effective treatment in several cancers, particularly triple-negative breast cancer (TNBC). Estrogen receptor α36 (ERα36), a variant of the estrogen receptor in ER-negative breast cancer cells, plays important roles in cancer cell proliferation. We investigated the role of ERα36 in regulating multidrug resistance protein 1 (MDR1) in MDA-MB-231 human breast cancer cells. The activation of ERα36 by BSA-conjugated estradiol (BSA-E2) increased cell viability under Adriamycin exposure, suggesting its involvement in promoting drug resistance. BSA-E2 treatment significantly reduced the intracellular rhodamine-123 levels by activating the MDR1 efflux function, which was linked to increased MDR1 transcription and protein expression. The mechanical ERα36-mediated BSA-E2-induced activation of EGFR and downstream signaling via c-Src led to an activation of the Akt/ERK pathways and transcription factors, NF-κB and CREB. Additionally, ERα36 is involved in activating Wnt/β-catenin pathways to induce MDR1 expression. The silencing of ERα36 inhibited the BSA-E2-induced phosphorylation of Akt and ERK, thereby reducing MDR1 expression via downregulation of NF-κB and CREB as well as Wnt/β-catenin signaling. These findings demonstrated that ERα36 promotes MDR1 expression through multiple non-genomic signaling cascades, including Akt/ERK-NF-κB/CREB and Wnt/β-catenin pathways, and highlight the role of ERα36 as a promising target to enhance chemotherapeutic efficacy in TNBC. Full article

Caffeic acid (CA) is a naturally occurring polyphenol antioxidant found in coffee, tea, fruits, and vegetables, known for its strong antioxidant, anti-inflammatory, and anti-aging properties. However, its cosmetic application is limited because of poor dermal absorption due to its high polarity. This study aimed to evaluate the antioxidant and skin-brightening effects of a novel lipophilic CA derivative, CAD (caffeic acid-3,4-dihydroxyphenylpropanolester). CAD was synthesized by conjugating CA with 3,4-DHPEA, a lipophilic antioxidant derived from olive oil. In both DPPH and ABTS assays, CAD exhibited more potent antioxidant activity than CA. In B16F10 melanoma cells, CAD significantly inhibited melanin production without cytotoxicity at concentrations lower than those required for CA. Cellular assays using DCF-DA staining demonstrated that CAD effectively reduced intracellular ROS levels. Mechanistic studies revealed that CAD inhibited tyrosinase activity and downregulated the expression of TYR, TRP-1, and TRP-2. Additionally, CAD suppressed MITF phosphorylation, along with reduced phosphorylation of ERK and JNK, elucidating its anti-melanogenic mechanism. Importantly, CAD showed dose-dependent skin-brightening effects in the 3D human skin model Melanoderm™, as evidenced by increased lightness and histological evaluation. In conclusion, CAD demonstrates strong potential as a safe and effective antioxidant and skin-brightening agent for cosmetic applications. Full article

This study evaluated the neuroprotective potential of peptain-1 conjugated to a cell-penetrating peptide (CPP-P1) in an ocular hypertension model of glaucoma. Brown Norway (BN) rats were subjected to intraocular pressure (IOP) elevation via intracameral injection of silicone oil (SO), with concurrent intravitreal injections of either CPP-P1 or a vehicle. Retinal cross-sections were analyzed for markers of neuroprotection, including cAMP response element-binding protein (CREB), phosphorylated CREB (p-CREB), growth-associated protein-43 (GAP43), synapsin-1 (SYN1), and superoxide dismutase 2 (SOD2). Hematoxylin and eosin staining was used to assess retinal-layer thickness. SO-treated rats exhibited significant reductions in the thickness of the inner nuclear layer (INL, 41%, p = 0.016), inner plexiform layer (IPL, 52%, p = 0.0002), and ganglion cell layer (GCL, 57%, p = 0.001). CPP-P1 treatment mitigated these reductions, preserving INL thickness by 32% (p = 0.059), IPL by 19% (p = 0.119), and GCL by 31% (p = 0.057). Increased levels of CREB (p = 0.17) and p-CREB (p = 0.04) were observed in IOP-elevated, CPP-P1-treated retinas compared to IOP-elevated, vehicle-treated retinas. Although overall GAP43 levels were low, there was a modest increase in expression within the IPL and GCL in SO- and CPP-P1-treated retinas (p = 0.15 and p = 0.09, respectively) compared to SO- and vehicle-treated retinas. SO injection reduced SYN1 expression in both IPL and GCL (p = 0.01), whereas CPP-P1 treatment significantly increased SYN1 levels in the IPL (p = 0.03) and GCL (p = 0.002). While SOD2 expression in the GCL was minimal across all groups, a trend toward increased expression was observed in CPP-P1-treated animals (p = 0.16). The SO model was replicated with SO removal after 7 days and monitored for 21 days followed by retinal flat-mount preparation to assess retinal ganglion cell (RGC) survival. A 42% loss in RGCs (p = 0.009) was observed in SO-injected eyes, which were reduced by approximately 37% (p = 0.03) with CPP-P1 treatment. These findings suggest that CPP-P1 is a promising neuroprotective agent that promotes retinal ganglion cell survival and the preservation of other retinal neurons, potentially through enhanced CREB signaling in a rat model of SO-induced ocular hypertension. Full article

Background/Objectives: Evolocumab inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9) binding to low-density lipoprotein (LDL) receptors, thus allowing more LDL receptors to remove LDL cholesterol from the blood. We aimed to determine the effects of evolocumab on the plasma lipid profile, reactive oxygen species (ROS), and nitric oxide (NO) generation in the heart of adult male obese Zucker rats. Methods: The rats were divided into lean and obese controls and obese rats treated with evolocumab subcutaneously at a dose of 10 mg/kg every two weeks. After 6 weeks, the lipid profile was determined in the plasma, and NO synthase (NOS) activity, thiobarbituric acid reactive substance (TBARS), conjugated diene (CD) concentration, and protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, nuclear factor kappaB (NF-κB), endothelial NOS (eNOS), and phosphorylated eNOS (peNOS) were measured in the heart. Results: Evolocumab treatment did not reduce body weight, relative heart weight, or systolic blood pressure in obese Zucker rats. Evolocumab treatment, however, reduced plasma LDL levels, TBARS, and CD concentrations along with decreasing expression of NADPH oxidase and NF-kappaB proteins in the heart. On the other hand, evolocumab had no effect on NOS activity or eNOS and peNOS protein expression. Conclusions: Besides its lipid-lowering effect, evolocumab may exert antioxidant properties and protect cardiomyocytes from lipid peroxidation while not affecting NO production. Full article

Introduction: In the central nervous system (CNS), proper interaction between neuronal and glial cells is crucial for the development of mature nervous tissue. Hypomyelinating leukodystrophies (HLDs) are a group of genetic CNS disorders characterized by hypomyelination and/or demyelination. In these conditions, genetic mutations disrupt the biological functions of oligodendroglial cells, which are responsible for wrapping neuronal axons with myelin sheaths. Among these, an amino acid mutation of the ubiquitin-fold modifier conjugating enzyme 1 (UFC1) is associated with HLD14-related disease, characterized by hypomyelination and delayed myelination in the brain. UFC1 is a critical component of the UFMylation system, functioning similarly to E2-conjugating enzymes in the ubiquitin-dependent protein degradation system. Methodology: We describe how a missense mutation in UFC1 (p.Arg23Gln) leads to the aggregation of UFC1 primarily in lysosomes in FBD-102b cells, which are undergoing oligodendroglial cell differentiation. Results: Cells with mutated UFC1 exhibit reduced Akt kinase phosphorylation and reduced expression of differentiation and myelination marker proteins. Consistently, these cells exhibit impaired morphological differentiation with a reduced ability to extend widespread membranes. Interestingly, hesperetin, a citrus flavonoid with known neuroprotective properties, was found to restore differentiation abilities in cells with the UFC1 mutation. Conclusions: These findings indicate that the HLD14-related mutation in UFC1 causes its lysosomal aggregation, impairing its morphological differentiation. Furthermore, the study highlights potential therapeutic insights into the pathological molecular and cellular mechanisms underlying HLD14 and suggests hesperetin as a promising candidate for treatment. Full article

Background: FAT10 is a member of the ubiquitin-like modifier family. Similar to ubiquitin, FAT10 has a distinct enzyme cascade consisting of E1-activating, E2-conjugating, and possibly several E3-ligating enzymes, which will covalently link FAT10 to substrate proteins in order to target them directly for proteasomal degradation. FAT10 was reported to be phosphorylated by IKKβ during infection with influenza A virus. Methods: To assess the difference between the FAT10-dependent degradation of phosphorylated FAT10 and the non-phosphorylated FAT10 wild type (FAT10 WT), a mutated FAT10 that mimicked phosphorylation (FAT10 D) was constructed by replacing several serine residues and one threonine residue with aspartic or glutamic acid. The FAT10 degradation or conjugation was compared between the phospho-mimetic FAT10 and the wild-type FAT10 with respect to the dependence of the E3 ligase TRIM25, the UBL-UBA protein NUB1L, and the proteasomal ubiquitin receptor RPN10. Results: The phospho-mimetic FAT10 was more efficiently conjugated to substrate proteins as compared to the wild-type FAT10, particularly if TRIM25 was co-expressed. Additionally, the phospho-mimetic FAT10 was not bound by NUB1L. However, this did not affect FAT10 D or FAT10 WT degradation. No differences were found in the binding affinity of phospho-mimetic FAT10 to RPN10. Conclusions: In brief, the phospho-mimetic FAT10 shows enhanced conjugation efficiency, but phosphorylation does not alter its degradation by the proteasome. This reveals that phosphorylation may fine-tune FAT10’s interactions with specific interaction partners without disrupting its core function of proteasomal degradation. Full article

Alum is the most used vaccine adjuvant, due to its safety, low cost and adjuvanticity to various antigens. However, the mechanism of action of alum is complex and not yet fully understood, and the immune responses elicited can be weak and antigen-dependent. While several antigens rapidly desorb from alum upon exposure to serum, phosphorylated proteins remain tightly bound through a ligand-exchange reaction with surface hydroxyls on alum. Here, bacterial proteins and glycoconjugates have been modified with phosphoserines, aiming at enhancing the binding to alum and prolonging their bioavailability. Tetanus toxoid protein and Salmonella Typhi fragmented Vi-CRM conjugate were used. Both antigens rapidly and completely desorbed from alum after incubation with serum, verified via a competitive ELISA assay, and set up to rapidly evaluate in vitro antigen desorption from alum. After antigen modification with phosphoserines, desorption from alum was slowed down, and modified antigens demonstrated more prolonged retention at the injection sites through in vivo optical imaging in mice. Both modified antigens elicited stronger immune responses in mice, after a single injection only, compared to unmodified antigens. A stronger binding to alum could result in potent single-dose vaccine candidates and opens the possibility to design novel carrier proteins for glycoconjugates and improved versions of bacterial recombinant proteins. Full article

This study introduces novel CD44-targeted and redox-responsive nanoparticles (FNPs), proposed as doxorubicin (DOX) delivery devices for breast cancer. A cationized and redox-responsive Human Serum Albumin derivative was synthesized by conjugating Human Serum Albumin with cystamine moieties and then ionically complexing it with HA. The suitability of FNPs for cancer therapy was assessed through physicochemical measurements of size distribution (mean diameter of 240 nm), shape, and zeta potential (15.4 mV). Nanoparticles possessed high DOX loading efficiency (90%) and were able to trigger the drug release under redox conditions of the tumor environment (55% release after 2 h incubation). The use of the carrier increased the cytotoxic effect of DOX by targeting the CD44 protein. It was shown that, upon loading, the cytotoxic effect of DOX was enhanced in relation to CD44 protein expression in both 2D and 3D models. DOX@FNPs significantly decrease cellular metabolism by reducing both oxygen consumption and extracellular acidification rates. Moreover, they decrease the expression of proteins involved in the oxidative phosphorylation pathway, consequently reducing cellular viability and motility, as well as breast cancer stem cells and spheroid formation, compared to free DOX. This new formulation could become pioneering in reducing chemoresistance phenomena and increasing the specificity of DOX in breast cancer patients. Full article

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by widespread inflammation and multi-organ damage. Toll-like receptor 7 (TLR-7) and autophagy have been implicated in SLE pathogenesis. Rice husk silica liquid (RHSL) has shown potential for modulating inflammatory responses, but its effects on SLE have not been thoroughly investigated. This study aims to evaluate the impact of RHSL on immune responses and autophagy in cell culture experiments, focusing on its effects on TLR-7 signaling, cytokine production, and autophagy modulation. RAW264.7 cells and human peripheral blood mononuclear cells (PBMCs) from healthy donors and SLE patients were used. Cells were stimulated with LPS or TLR-7 agonists and treated with RHSL. Cell viability was assessed, and cytokine levels (TNF-α and IL-6) were measured by ELISA. Autophagy-related proteins (LC3II, ATG5-ATG12) were analyzed by Western blotting. The effect of autophagy inhibition was studied using 3-methyladenine (3-MA). A concentration of 100 μg/mL RHSL did not affect cell viability but significantly reduced the TNF-α production in TLR-7 agonist-stimulated RAW264.7 cells (compared to TLR-7 alone, 3.41 ± 0.54 vs. 6.72 ± 0.07 folds) and PBMCs (compared to TLR-7 alone, 0.97 ± 0.19 vs. 1.40 ± 0.33 folds). RHSL enhanced autophagy, as evidenced by increased LC3II (4.35 ± 1.08 folds) and ATG5-ATG12 (7.07 ± 1.30 folds) conjugation in both RAW264.7 cells and SLE patient-derived PBMCs. The reduction in TNF-α production by RHSL was attenuated by 3-MA, indicating that autophagy plays a role in this process. RHSL also inhibited the translocation of phosphorylated NF-κB into the nucleus, suggesting a mechanism for its anti-inflammatory effects. RHSL exhibits potential as an immunomodulatory agent in SLE by enhancing autophagy and modulating TLR-7 signaling pathways. These findings suggest that RHSL could offer therapeutic benefits for managing inflammatory responses in SLE and warrant further investigation into its clinical applications. Full article

In this study, we report a novel platinum–doxorubicin conjugate that demonstrates superior therapeutic indices to cisplatin, doxorubicin, or their combination, which are commonly used in cancer treatment. This new molecular structure (1) was formed by conjugating an amphiphilic Pt(IV) prodrug of cisplatin with doxorubicin. Due to its amphiphilic nature, the Pt(IV)–doxorubicin conjugate effectively penetrates cell membranes, delivering both cisplatin and doxorubicin payloads intracellularly. The intracellular accumulation of these payloads was assessed using graphite furnace atomic absorption spectrometry and fluorescence imaging. Since the therapeutic effects of cisplatin and doxorubicin stem from their ability to target nuclear DNA, we hypothesized that the amphiphilic Pt(IV)–doxorubicin conjugate (1) would effectively induce nuclear DNA damage toward killing cancer cells. To test this hypothesis, we used flow the cytometric analysis of phosphorylated H2AX (γH2AX), a biomarker of nuclear DNA damage. The Pt(IV)–doxorubicin conjugate (1) markedly induced γH2AX in treated MDA-MB-231 breast cancer cells, showing higher levels than cells treated with either cisplatin or doxorubicin alone. Furthermore, MTT cell viability assays revealed that the enhanced DNA-damaging capability of complex 1 resulted in superior cytotoxicity and selectivity against human cancer cells compared to cisplatin, doxorubicin, or their combination. Overall, the development of this amphiphilic Pt(IV)–doxorubicin conjugate represents a new form of combination therapy with improved therapeutic efficacy. Full article

The glutamine–histidine–glycine–valine (QHGV), a peptide derived from oysters, exhibits antioxidant activity and is being actively researched as a potential pharmaceutical and functional cosmetic ingredient. In this study, we synthesized the QHGV peptide and explored the hitherto unknown anti-inflammatory effects of QHGV. The antioxidant property was also characterized by conjugating with various naturally derived phenolic acids, such as caffeic, gallic, ferulic, sinapinic, and vanillic acids. Conjugation with phenolic acids not only enhanced the antioxidant activity of QHGV but also diminished the lipopolysaccharide-induced generation of reactive oxygen species (ROS) in the murine macrophage cell line, RAW 264.7. The reduction in the levels of reactive oxygen species led to the reduced mRNA expression of inducible nitric oxide synthase (iNos) and cyclooxygenase 2 (Cox-2), resulting in an anti-inflammatory effect through the inhibition of the phosphorylation of mitogen-activated protein kinase, including extracellular signal-activated protein kinase, c-Jun NH2-terminal kinase, and p38. Furthermore, the phenolic acid-conjugated peptides increased the mRNA and protein levels of collagen type I, indicative of a wrinkle-improvement effect. The phenolic acid conjugates of the peptide were not cytotoxic to human keratinocytes such as HaCaT cells. These results suggest that phenolic acid conjugation can enhance the potential of peptides as drug and cosmetic resources. Full article

Currently, photocatalysis of the two-dimensional (2D) conjugated phthalocyanine framework with a single Fe atom (CPF-Fe) has shown efficient photocatalytic activities for the removal of harmful effluents and antibacterial activity. Their photocatalytic mechanisms are dependent on the redox reaction—which is led by the active species generated from the photocatalytic process. Nevertheless, the molecular mechanism of CPF-Fe antimicrobial activity has not been sufficiently explored. In this study, we successfully synthesized CPF-Fe with great broad-spectrum antibacterial properties under visible light and used it as an antibacterial agent. The molecular mechanism of CPF-Fe against Escherichia coli and Salmonella enteritidis was explored through multi-omics analyses (transcriptomics and metabolomics correlation analyses). The results showed that CPF-Fe not only led to the oxidative stress of bacteria by generating large amounts of h⁺ and ROS but also caused failure in the synthesis of bacterial cell wall components as well as an osmotic pressure imbalance by disrupting glycolysis, oxidative phosphorylation, and TCA cycle pathways. More surprisingly, CPF-Fe could disrupt the metabolism of amino acids and nucleic acids, as well as inhibit their energy metabolism, resulting in the death of bacterial cells. The research further revealed the antibacterial mechanism of CPF-Fe from a molecular perspective, providing a theoretical basis for the application of CPF-Fe photocatalytic antibacterial nanomaterials. Full article