Search Results (3,135)

Background/Objectives: Hypercholesterolemia remains a major risk factor for cardiovascular disease and a leading cause of global mortality. Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes degradation of low-density lipoprotein receptors (LDLR), thereby reducing LDL-cholesterol (LDL-C) clearance. While monoclonal antibodies (mAbs) targeting PCSK9 are effective, their short half-life requires frequent dosing and incurs high treatment costs. This study evaluates a novel peptide-based Anti-PCSK9 product aimed at providing sustained LDL-C reduction. Methods: A novel PCSK9 based-peptide conjugated to diphtheria toxoid (DT) was evaluated in various preclinical models: high-fat diet-fed C57BL/6 mice, APOB100/hCETP transgenic mice, BALB/c mice and normocholesterolemic non-human primates. Immunogenicity (Anti-PCSK9 antibody titers, binding affinity by SPR), pharmacodynamics (LDL-C levels, inhibition of PCSK9-LDLR interaction) and safety were assessed. Toxicity was evaluated in rodents, rabbits and dogs through clinical monitoring, histopathology, organ function and safety pharmacology studies. Results: The Anti-PCSK9 product induced robust and long-lasting immune response in all models antibody titers in BALB/c mice peaked by week 6 and persisted for 12 months. LDL-C reductions of 44% in APOB100/hCETP mice and 37% in C57BL/6 mice correlated with high antibody titers and strong PCSK9-binding affinities (85 and 49 RU), leading to 59% and 58% inhibition of PCSK9-LDLR interaction, respectively. Non-human primates showed sustained responses. No systemic toxicity was observed; injection-site reactions were mild and reversible. No adverse effects were detected on cardiovascular, neurological, or respiratory systems. Conclusions: This peptide-based Anti-PCSK9 therapy offers sustained efficacy and safety, representing a promising long-acting alternative for managing hypercholesterolemia. Full article

Background/Objectives: The global increase in multidrug-resistant (MDR) bacterial infections underscores the urgent need for effective and sustainable antimicrobial alternatives. This study investigates the antimicrobial activity of exometabolite-based formulations (ExAFs), derived from the cell-free supernatants (CFS) of native lactic acid bacteria (LAB) applied individually or in combination thereof, against MDR-Escherichia coli strain L1PEag1. Methods: Fourteen ExAFs were screened for inhibitory activity using time–kill assays, and structural damage to bacterial cells was assessed via scanning and transmission electron microscopy (SEM/TEM). The most potent formulation was further characterized by liquid chromatography–tandem mass spectrometry (LC–MS/MS) employing a Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra (SWATH) approach for untargeted metabolite profiling. Results: Among the tested formulations, E10, comprising CFS from Weissella cibaria UTNGt21O, exhibited the strongest inhibitory activity (zone of inhibition: 17.12 ± 0.22 mm), followed by E1 (CFS from Lactiplantibacillus plantarum Gt28L and Lactiplantibacillus plantarum Gt2, 3:1 v/v) and E2 (Gt28L CFS + EPS from Gt2, 3:1 v/v). Time–kill assays demonstrated rapid, dose-dependent bactericidal activity: E1 and E10 achieved >98% reduction in viable counts within 2–3 h, at 1× MIC, while E2 sustained 98.24% inhibition over 18 h, at 0.25× MIC. SEM and TEM revealed pronounced ultrastructural damage, including membrane disruption, cytoplasmic condensation, and intracellular disintegration, consistent with a membrane-targeting mode of action. Metabolomic profiling of E10 identified 22 bioactive metabolites, including lincomycin, the proline-rich peptide Val–Leu–Pro–Val–Pro–Gln, multiple flavonoids, and loperamide. Several compounds shared structural similarity with ribosomally synthesized and post-translationally modified peptides (RiPPs), including lanthipeptides and lassopeptides, suggesting a multifaceted antimicrobial mechanism. Conclusions: These findings position ExAFs, particularly E10, as promising, peptide-rich, bio-based antimicrobial candidates for food safety or therapeutic applications. The co-occurrence of RiPP analogs and secondary metabolites in the formulation suggests the potential for complementary or multi-modal bactericidal effects, positioning these compounds as promising eco-friendly alternatives for combating MDR pathogens. Full article

Increasing evidence points to members of the chloride intracellular ion channel (CLIC) protein family performing a variety of functions within cells—classifying them as moonlighting proteins—and serving as natural cellular antioxidant protective agents. Apart from their role as membrane-inserting ion channels, members of the CLIC family also possess enzymatic oxidoreduction activity in their soluble form. The current study is the first to specifically examine the S-glutathionylation catalytic activity of several purified recombinant CLIC protein members (rCLIC1, rCLIC3, and rCLIC4) by directly measuring their ability to deglutathionylate and glutathionylate a synthetic model peptide via an in vitro tryptophan fluorescence quenching assay. Effects of pH and temperature on this activity were also assessed. Our findings provide insights into a likely previously uncharacterised mechanism by which CLIC proteins serve as cellular antioxidant protective enzymes via their S-glutathionylation capabilities. Full article

Biofilms develop in sequential steps resulting in the formation of three-dimensional communities of microorganisms that are encased in self-produced extracellular polymeric substances. Biofilms play a key role in device-associated infections, such as catheter-associated urinary tract infections (CAUTIs), because they protect microorganisms from standard antimicrobial therapies. Current strategies to prevent biofilm formation in catheter-related infections, including prophylactic antibiotics and antibiotic-coated catheters, have been unsuccessful. This finding highlights a need for novel approaches to address this clinical problem. In this study, biofilm-forming phenotypes of common Gram-negative bacteria associated with CAUTIs were treated with antisense peptide nucleic acids (PNAs), and biofilm biomass and bacterial viability were quantified after 24 h of treatment. A cocktail of PNAs targeting the global regulator genes rsmA, amrZ, and rpoS in Pseudomonas aeruginosa significantly reduced viability and thus appropriately eliminated biofilm biomass. Antisense-PNAs against these same gene targets and the motility regulator gene motA inhibited biofilm formation among isolates of Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli but did not reduce bacterial viability. These results suggest that antisense-PNAs are a promising new technology in preventing biofilm formation in urinary catheters, especially as a potential complement to conventional antimicrobials. Full article

The peptide hormone kisspeptin, signaling via its receptor, KISS1R, decreases hepatic steatosis and protects against metabolic dysfunction-associated steatotic liver disease (MASLD). Enhanced de novo lipogenesis (DNL) contributes to MASLD. Here, we investigated whether kisspeptin treatment in obese, diabetic mice directly attenuates DNL. DNL was assessed in kisspeptin-treated mouse livers, using a mouse model of MASLD, (DIAMOND mice), employing ²H₂O-enriched water, mass spectrometry analysis, and transcriptomic profiling. Gene and protein expression were evaluated in primary hepatocytes and livers. Additionally, hepatic Kiss1r expression was increased in DIAMOND mice, following which various biochemical and metabolic assessments were employed. Metabolic tracing in kisspeptin-treated steatotic livers demonstrated a decrease in the DNL of free fatty acids (FFAs), known to be associated with diabetes, steatosis, and hepatocellular carcinoma. Transcriptomic profiling of kisspeptin-treated livers identified disruption of key metabolic pathways, the most prominent being a decrease in fatty acid metabolism, and downregulation of Cidea, a key regulator of lipid droplet formation. Kisspeptin treatment of FFA-loaded primary mouse hepatocytes significantly decreased Cidea expression. Mechanistically, we found that kisspeptin administration decreased levels of transcription factor SREBP-1c, a crucial regulator of DNL, and CIDEA. Thus, enhanced KISS1R signaling limits hepatic DNL, suggesting a crucial role in restricting MASLD. Full article

Species of the Ferula genus are known for their traditional medicinal applications against diverse illnesses. Our previous study was the first to suggest the cholinesterase inhibitory activity of Ferula persica L. However, the neuroprotective efficacy of therapeutic molecules is often limited by their ability to cross the blood–brain barrier (BBB) and reach the brain. In the present study, the BBB permeability of the main molecules present in the aerial parts and roots of F. persica L. extracted under optimum conditions was assessed using two well-established methods: the parallel artificial membrane permeability assay (PAMPA) and the HBMEC cell culture in vitro model. The results demonstrated a high permeability of several neuroprotective compounds, such as apigenin, diosmetin, and α-cyperone. Additionally, the neuroprotective potential of F. persica extracts was evaluated using SH-SY5Y neuron-like cells exposed to different insults, including oxidative stress (H₂O₂), excitotoxicity (L-glutamate), and Aβ1-42 peptide toxicity. However, none of the obtained extracts provided significant protection. This study highlights the importance of in vitro cell culture models for a better understanding of BBB permeability mechanisms and reports the tentative identification of newly formed sulfated metabolites derived from the metabolism of ferulic acid, apigenin, and diosmetin by HBMEC cells. Full article

Oxidative stress, driven by excess reactive oxygen species (ROS), is a key factor in the progression of neurodegenerative diseases like Alzheimer’s disease (AD). In this context, copper dysregulation can also contribute to this imbalance, being responsible for enhanced ROS production, so that copper scavenging has been investigated as a possible therapeutic strategy. This study investigates the behavior of two isostructural ligands, featuring an N₃O donor set, that effectively chelate Cu(II) in aqueous solution. Interestingly, their resulting mono- or dinuclear copper complexes feature a coordination environment suitable to foster antioxidant activity. By transforming copper’s oxidant potential into antioxidant action, these systems may reduce copper-induced oxidative damage. The work examines the pH-dependent metal-binding behavior of the ligands, the catalytic properties of the resulting complexes under physiological conditions, and their ability to inhibit β-amyloid peptide aggregation. Full article

Facial aging is a multifactorial process involving changes in bone, fat compartments, ligaments, muscles, and skin. Collagen biostimulators, including synthetic agents and autologous platelet concentrates, have gained attention for facial rejuvenation. Injectable platelet-rich fibrin (i-PRF), a second-generation autologous concentrate, has shown promising regenerative properties due to its natural composition and growth factors. Cosmetic peptides, such as palmitoyl pentapeptide-4 (Matrixyl) and Tetrapeptide-21 (GEKG), are also studied for their ability to stimulate collagen synthesis and remodel the extracellular matrix. This in vitro study examined the potential synergistic effects of i-PRF combined with Matrixyl or GEKG on human dermal fibroblast viability, proliferation, and ECM-related gene expression. Fibroblasts were cultured under six conditions: control, i-PRF alone, Matrixyl alone, GEKG alone, i-PRF + Matrixyl, and i-PRF + GEKG. Viability and proliferation were assessed via MTT, crystal violet, and RealTime-Glo™ assays. Gene expression of COL1A1, FN1, and HAS1 was measured using RT-qPCR. The combinations, especially i-PRF + GEKG, led to increased cell viability and upregulated ECM-related genes at 72 h. These effects were stronger than the individual treatments, suggesting synergistic effects, especially with GEKG. These findings highlight the clinical potential of combining autologous platelet concentrates with bioactive peptides for dermal regeneration. Further preclinical and clinical studies are warranted. Full article

Background/Objectives: Disruption of AMPAR trafficking at excitatory synapses contributes to impaired synaptic plasticity and memory formation in several neurological and psychiatric disorders. Arc, an immediate early gene product, has been shown to interact with the AMPAR auxiliary subunit TARPγ2, affecting receptor mobility and synaptic stabilization. Methods: To investigate the in vivo functional effects and protein interactions of the Arc-TARPγ2 interfering peptide RIPSYR, we performed in vivo electrophysiology and spatial memory assessments in male rats. as well as proteomic analyses of peptide-protein interactions in synaptosome lysates. We then used in silico docking to evaluate candidate binding partners. Results: In the present study, in vivo electrophysiological measurements revealed that RIPSYR administration altered early-phase long-term potentiation at CA3 synapses of male rats. Subsequent behavioral testing that assessed spatial memory performance revealed depleted memory retrieval after 24 h, indicating that the peptide has a systemic effect on experience-dependent plasticity. Then, we examined the molecular interactome of RIPSYR using magnetic bead-based immunoprecipitation and subsequent LC-MS identification on synaptosome lysates, and identified additional candidate binding partners, suggesting that the peptide may have broader modulatory effects. RIPSYR binding to the other putative binding partners are investigated by in silico methods. Conclusion: Our results raise the question of how the molecular interactions of RIPSYR contribute to its sum effects on electrophysiology and behavior. Full article

The melon fly Zeugodacus cucurbitae (Coquillett) is a globally invasive pest responsible for substantial economic losses in the fruit and vegetable industries. Insulin-like peptides (ILPs) are evolutionarily conserved neuropeptides that play a crucial role in insect reproduction. In this study, six ZcILPs from the melon fly, designated as ZcILP1–6, were cloned. Phylogenetic analysis demonstrated a strong orthologous link with Dipteran ILPs. Spatiotemporal expression profiling revealed that ZcILP1 and ZcILP3 exhibit preferential enrichment in the adult female fat body, with their expression specifically and significantly upregulated in 5-day-old individuals. Their expression decreased 12, 24, and 48 h post-starvation and increased upon re-feeding. Silencing ZcILP1 and ZcILP3 resulted in reduced ovarian size by 51.42% and 69.17%, respectively. Furthermore, silencing ZcILP1 or ZcILP3 significantly decreased the transcriptional levels of genes downstream of the insulin signaling pathway (ISP), notably the target of rapamycin (ZcTOR) and Forkhead box O (ZcFOXO). Concurrently, the expression of Vitellogenin (ZcVg), a gene associated with reproduction, was significantly downregulated. These findings indicate that ZcILP1 and ZcILP3 regulate ZcVgs expression and ovarian development through ISP, suggesting them as potential targets for green control of Z. cucurbitae. Full article

Bacteriocins are ribosomal synthesized antimicrobial peptides produced by bacteria, but their low yields limit industrial applications as food preservatives. This study aimed to optimize the culture conditions of Pediococcus acidilactici CCFM18 and investigate the biological properties of the bacteriocin. The culture temperature, initial pH, and culture time significantly affected the growth of P. acidilactici CCFM18 and bacteriocin production. The optimal culture conditions determined through response surface methodology (RSM) were a culture temperature of 35 °C, an initial pH of 7.0, and a growth time of 16 h. Under these conditions, bacteriocin production reached 1454.61 AU/mL, representing a 1.8-fold increase compared to pre-optimization levels. Biological characterization revealed that the bacteriocin exhibited strong thermal stability (up to 100 °C for 30 min) and pH stability (pH 2–9), but was sensitive to proteolytic enzymes, including pepsin, trypsin, papain, and protease K. The bacteriocin demonstrated antimicrobial activity against both Gram-positive and Gram-negative bacteria, including Enterococcus faecalis and Escherichia coli. These findings provide a theoretical basis for the industrial production and application of the bacteriocin. Full article

Nowadays, members of the genus Enterobacter have been documented as human and aquaculture pathogens. To date, no reports have described Enterobacter bugandensis infecting Hippocampus abdominalis. In the present study, an isolate of E. bugandensis, designated H4, was identified as a causative pathogen in cultured H. abdominalis following Koch’s postulate, and its virulence properties were further described. The isolate’s genome consisted of a single circular chromosome and harbored several virulence and resistance genes, including, but not limited to, csgG, acrB, hcp, gndA, galF, rpoS, fur, rcsB, and phoP involved in adherence, antimicrobial activity, effector delivery systems, immune modulation, and regulation, as well as baeR, blaACT-49, ramA, hns, ftsI, acrA, gyrA, fabI, crp, oqxB, parE, gyrB, phoP, rpoB, tuf, ptsI, and fosA2 functioning against aminoglycoside, cephamycin, disinfecting agent and antiseptic, fluoroquinolone, macrolide, peptide, and other antimicrobials. Additionally, the isolate exhibited multiple resistance to cephalosporins, penicillins, and tetracyclines and demonstrated a median lethal dose (LD₅₀) of 4.47 × 10⁵ CFU/mL in H. abdominalis. To our knowledge, this is the first study to describe E. bugandensis infecting H. abdominalis. These findings highlight the zoonotic potential of E. bugandensis and underscore the need for targeted health management in seahorse farming. Full article

Bacterial infection is a cause of life-threatening diseases. The emergence of antimicrobial-resistant bacteria exacerbates this situation, highlighting the need for the discovery of new antimicrobial agents. Our previous study identified a novel antimicrobial peptide, BrSPR20-P1 (P1), which showed potential activity against MRSA. Additionally, silver nanoparticles (AgNPs) exhibit broad-spectrum antibacterial activity, capable of killing multidrug-resistant bacteria. The combination of antimicrobial agents presents a novel strategy for combating these pathogens. This study aimed to evaluate the antibacterial activity of the combination of P1 and AgNPs. It revealed that the combinations showed synergy. The P1 and AgNP mixture at a concentration of 1 and 8 µg/mL (1:8) doubled the activity against S. aureus and MRSA, while that combination of 64 and 64 µg/mL (64:64) exhibited broad-spectrum activity, expanding to E. coli with a 32-fold increase. These combinations exhibited a bactericidal effect, showing the rapid killing of tested bacteria at 10× MIC, with killing rates during the first 3 h ranging from 4.04 ± 0.01 to 4.31 ± 0.03 h⁻¹. The P1 and AgNP mixtures caused a low risk of antibacterial resistance up to 30 passages. It was demonstrated that the synergistic activity of P1 and AgNPs occurred through the disruption of cell walls and membranes, leakage of intracellular materials, and cell lysis. Additionally, the mixtures appeared to interact with bacterial genomic DNA, as indicated by a gel retardation assay. These activities of the combinations were concentration-dependent. The 1:8 µg/mL mixture caused low hemolysis and cytotoxicity and did not impede the wound healing process. In contrast, although the 64:64 µg/mL mixture showed excellent antibacterial efficacy, it was toxic to erythrocytes and mammalian cells. It implies that dose optimization is required to balance its efficacy and toxicity. Therefore, the P1 and AgNP combinations exhibit synergistic antimicrobial activity and have the potential to resolve bacterial infections. Full article

Background: Enkephalins are endogenous opioid peptides that modulate cardiovascular and renal function and are overexpressed in patients with acute heart failure (AHF). Although biologically active enkephalins lack a favorable biomarker profile, their stable surrogate proenkephalin 119–159 (PENK) appears to display prognostic value in AHF settings. The aim of the present study was to evaluate the role of point-of-care (POC) PENK in predicting mortality and worsening renal function (WRF) in patients presenting to the emergency department (ED) with AHF. Methods: In this single-center observational study, 107 patients presenting to the ED with AHF were prospectively enrolled. We measured PENK levels upon ED presentation with a commercially available POC immunoassay and investigated their association with WRF within 48 h and all-cause mortality during a 1-year follow-up. Results: The patients had a mean age of 72 ± 13 years, and 58% were men. Moreover, 62% had acutely decompensated chronic heart failure (HF), 24% had pulmonary edema, 9% had cardiogenic shock, and 5% had right HF. The median PENK levels were 111 [60–193] pmol/L. PENK was independently associated with WRF (adjusted OR, 95% CI: 15.4 [2.0–120.2]; p = 0.009), with levels of ≥90.5 pmol/L identified as the optimal cut-off for predicting WRF (AUC: 0.690; p < 0.001). PENK was also an independent predictor of short- and long-term all-cause mortality, with an optimal cut-off of ≥95.8 pmol/L (AUC for 30-day, 90-day, and 1-year mortality: 0.717, 0.723, and 0.724, respectively; all p < 0.001). Conclusions: In patients presenting to the ED with AHF, POC PENK may serve as an early prognostic marker of WRF and short- and long-term mortality. Full article

Sulforaphane, a natural isothiocyanate predominantly found in cruciferous vegetables, has shown potential in preventing and treating Helicobacter pylori infection. However, the underlying metabolic mechanisms remain largely unclear. This study employed high-coverage metabolomics and lipidomics methods to comprehensively investigate the effects of sulforaphane on the serum and liver metabolic profiles of H. pylori-infected mice. Metabolomics and lipidomics analysis revealed that H. pylori infection disrupted multiple metabolic pathways, leading to perturbations in amino acids, fatty acids, bile acids, and various lipid species. Sulforaphane treatment can ameliorate these disruptions, notably reversing alterations in serum glycerophospholipids and restoring hepatic levels of amino acids, bile acids, glycerophospholipids, ceramides, and peptides. Key metabolic pathways implicated included glutathione metabolism and glycine and serine metabolism, which are associated with antioxidant defense and host resistance to pathogenic infections. These findings offer a comprehensive metabolic basis for understanding the therapeutic effects of sulforaphane against H. pylori infection. Full article