Search Results (48,696)

Antimicrobial peptides (AMPs) have re-emerged as promising anti-infective agents, particularly against multidrug-resistant bacteria; however, their therapeutic development remains constrained by proteolytic degradation, host cell toxicity, and rapid systemic clearance. Rather than focusing solely on sequence discovery, recent efforts have shifted toward structural and supramolecular modification strategies aimed at improving stability, selectivity, and pharmacological performance. This review critically analyzes intramolecular modifications—including phosphorylation, glycosylation, acetylation, methylation, and backbone cyclization—that modulate peptide conformation and resistance to enzymatic degradation. In parallel, extramolecular approaches such as PEGylation, lipidation, and conjugation to antibiotics, siderophores, or antibodies are examined in the context of enhanced targeting and prolonged bioavailability. Particular emphasis is placed on localized delivery systems, including hydrogels, polymeric films, and nanofibrous scaffolds, which enable spatially controlled administration and mitigate systemic exposure. By integrating evidence from ex vivo and in vivo infection models, this work delineates the translational potential and remaining bottlenecks of chemically engineered AMP platforms for skin and soft tissue infections. Full article

(1) Background: The “Bider” marking refers to the symmetrical black stripes distributed on the shoulder blades of Dun Mongolian horses, representing an ancestral trait of significant genetic value. However, the molecular mechanisms underlying its formation remain unclear. This study aims to elucidate the molecular basis of these markings by comparing transcriptomic differences in skin tissues from variously pigmented areas of Mongolian horses’ “Bider” patterns. (2) Methods: Using three Dun Mongolian horses as subjects, skin tissue samples were collected from their shoulders (dark-marked and light-marked areas), dorsal midline, and croup regions for transcriptome sequencing. Differentially expressed genes were identified based on sequencing data, followed by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Key findings were validated through quantitative reverse transcription polymerase chain reaction (qRT-PCR). (3) Results: The sequencing yielded approximately 893 million high-quality clean reads, with an overall alignment rate exceeding 96%. A total of 140 to 775 differentially expressed genes were identified. GO enrichment analysis revealed that these genes were significantly enriched in biological processes related to pigment metabolism, skin and hair follicle development, signal transduction (including calcium and cyclic guanosine monophosphate (cGMP) signaling), and immune regulation. KEGG analysis further indicated that multiple pathways closely associated with pigment regulation, including the calcium signaling pathway, tyrosine metabolism, cyclic adenosine monophosphate (cAMP) signaling pathway, and melanoma pathway, were significantly enriched across different tissue comparison groups, suggesting their potential key roles in coat color phenotype formation. The reliability of the sequencing data was corroborated by the results of qRT-PCR validation. (4) Conclusions: This study conducted a transcriptome analysis of skin samples from various pigmented regions of the Dun Mongolian horse’s Bider marking, revealing that the formation of this marking is associated with the differential expression of numerous genes and is co-regulated by multiple pigment-related signaling pathways. Full article

Ultraviolet (UV) irradiation induces complex skin damage, including hyperpigmentation, oxidative stress, and alterations in proteins related to keratinocyte differentiation and epidermal barrier-associated status. This study investigated the multifunctional protective effects of Padina arborescens ethanolic extract (PAEE) against skin damage in melanocytes, keratinocytes, and zebrafish. In alpha-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 cells, PAEE effectively suppressed the protein kinase A (PKA)/cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) signaling pathway, which was associated with reduced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase, leading to decreased melanin synthesis. PAEE also exhibited photoprotective properties by reducing reactive oxygen species (ROS), inhibiting interleukin-1 beta (IL-1β), and attenuating matrix metalloproteinase-1 (MMP-1) upregulation associated with UVB (ultraviolet B)-induced photodamage in HaCaT keratinocytes. Notably, PAEE restored the UVB-reduced expression of filaggrin and involucrin, representative markers of keratinocyte differentiation and epidermal barrier-associated status, in HaCaT keratinocytes. In zebrafish embryos, PAEE suppressed α-MSH-induced melanin accumulation and UVB-induced ROS generation at non-toxic concentrations. Taken together, these results suggest that PAEE exerts anti-melanogenic and photoprotective effects in cellular and zebrasfish models and may serve as a promising marine-derived ingredient for cosmeceutical applications targeting UVB-related skin damage. Full article

The safe and precise regulation of therapeutic gene expression remains a major challenge for mammalian synthetic biology and cell-based therapies. Many existing inducible systems rely on non-mammalian regulatory components or ligands with limited clinical compatibility. Designer receptors exclusively activated by designer drugs (DREADDs) offer a human G protein-coupled receptor (GPCR)-based framework for pharmacological control of intracellular signaling, yet their application as clinically relevant gene-regulation platforms remains underexplored. Here, we report a clozapine-responsive gene switch that couples a designer GPCR to signaling-dependent transcriptional control. By linking clozapine-activated receptors to cyclic adenosine monophosphate (cAMP)- or calcium-responsive synthetic promoters, receptor activation is converted into robust transgene expression across a broad dynamic range, with sensitivity to sub-nanomolar to low-nanomolar clozapine concentrations. In vivo, alginate-encapsulated reporter cells implanted in C57BL/6J mice responded to systemic or local clozapine administration with efficient secretion of a reporter protein, achieving robust induction at low daily doses (0.3 mg/kg) following either oral administration or local delivery. Together, these results establish a human GPCR-based clozapine-responsive gene switch that integrates regulation by a clinically used small molecule with modular transcriptional outputs, providing an additional approach for pharmacologically controllable gene expression in mammalian cells and in vivo. Full article

Aeromonas hydrophila is a major seafood-borne pathogen capable of persisting under preservative-associated stress by entering a viable but non-culturable (VBNC) state, thereby evading culture-based detection. Here, untargeted metabolomics was applied as the primary analytical approach to elucidate metabolic reprogramming during VBNC formation under seafood-relevant preservation conditions. Cells were incubated at 4 °C for 30 days in sodium benzoate-supplemented saline, comparing 0.85% NaCl (culturable condition) and 4% NaCl (VBNC-inducing condition), with sampling every 6 days. Under 4% NaCl with sodium benzoate, culturability declined from 6.18 log CFU/mL at day 0 to undetectable levels by day 30, while cell viability was retained, confirming VBNC induction. UHPLC–ESI–QTOF–MS profiling detected over 893 intracellular metabolic features, of which 518 metabolites were significantly altered between VBNC and culturable states at day 30. Principal component analysis revealed clear, time-dependent metabolic divergence, with the VBNC trajectory explaining 34.4% (PC1) and 11.5% (PC2) of total variance. Pathway enrichment analysis demonstrated significant remodeling of alanine, aspartate and glutamate metabolism (8/28 hits, FDR = 5.7 × 10⁻⁴); arginine biosynthesis (5/14 hits, FDR = 5.44 × 10⁻³); purine metabolism (10/70 hits, FDR = 8.34 × 10⁻³); and pyrimidine metabolism (7/39 hits, FDR = 1.35 × 10⁻²), indicating nitrogen conservation and metabolic downshifting. A robust biomarker panel, including depleted cyclic AMP, aminoadipic acid, hypotaurine, O6-CM-dG, and betaine, and enriched urocanic acid, pipecolic acid, proline, azelaic acid, and orcinol perfectly discriminated VBNC from culturable cells. These findings demonstrate that sodium benzoate-based preservation can induce a metabolically reprogrammed VBNC state in A. hydrophila, highlighting a hidden food safety risk beyond culture-based assessment. Full article

Oocyte competency is a crucial determinant of fertilisation success and the initial development of embryos in assisted reproductive technologies. The metabolic and biochemical environment of the ovarian follicle is crucial for determining oocyte developmental potential, alongside genetic integrity. The follicular microenvironment includes a complex network of signalling chemicals that regulate mitochondrial activity, steroidogenesis, oxidative balance, and cellular energy metabolism. Recently, metabolic hormones originating from adipose tissue and skeletal muscle, namely, adipokines and myokines, have received considerable focus as crucial regulators of ovarian physiology. Adiponectin, irisin, and the recently identified hormone asprosin have emerged as crucial metabolic regulators influencing granulosa cell activity, mitochondrial bioenergetics, insulin signalling pathways, and redox homeostasis inside the follicular niche. Adiponectin mostly provides metabolic protection by activating AMP-activated protein kinase (AMPK) and improving insulin sensitivity, which in turn enhances mitochondrial efficiency and steroidogenic function in granulosa cells. Irisin, derived from the breakdown of fibronectin type III domain-containing protein 5 (FNDC5), aids the developing oocyte by facilitating mitochondrial biogenesis, augmenting oxidative phosphorylation, and altering cellular defence mechanisms against oxidative stress. Conversely, asprosin has been associated with glucogenic signalling, metabolic stress, and probable mitochondrial malfunction, suggesting a possible relationship between systemic metabolic problems and negative reproductive consequences. Clinical and experimental research indicate that the levels of these metabolic regulators in follicular fluid may correlate with ovarian response, oocyte quality, fertilisation rates, and embryo development during in vitro fertilisation cycles. This review consolidates current molecular, cellular, and clinical information, clarifying the pathways by which adipokines and myokines influence follicular metabolism and impact oocyte competency. Understanding the metabolic connections between systemic endocrine signals and the follicular milieu may provide novel indicators for reproductive prognosis and provide new treatment targets to improve assisted reproduction outcomes. Full article

Fungal hydrophobins reduce the surface tension of hyphae so that hyphae can grow into the air. Reduced expression of hydrophobin genes results in abnormal morphogenesis of both hyphae and the fruiting body of Flammulina filiformis. Previous studies showed that filamentous-growth MAPK signaling pathway directly modulates pseudohyphae formation in budding yeast, so we hypothesized that the specific transcription factor in this pathway may also directly regulate the expression of hydrophobin genes in F. filiformis. Downstream of the G protein, the cAMP/PKA signaling pathway is parallel with the filamentous-growth MAPK signaling pathway in regulating the filamentous growth of fungi. Thus, the cAMP addition test was carried out to exclude the involvement of the PKA/cAMP signaling pathway in aerial-hyphae deficiency of the three mutants used in our previous study. Transcriptomic analysis showed common changes in the MAPK signaling pathway of the three mutants, including 6 downregulated and 3 upregulated genes in common. Transcription factor Tec1 was one of the upregulated genes, and it is a pathway-specific transcription factor for filamentous growth. Motif prediction showed that putative binding sites of Tec1 and Ste12 existed in the promoter region of the three chosen hydrophobin genes mentioned in our previous study, and DAP-seq analysis suggested that putative binding sites of Tec1 and Ste12 were located in 10 hydrophobin genes, respectively, and there were 8 in common for both the transcription factors. These results gave suggestive evidence supporting our hypothesis. We have identified a potential regulatory connection between the filamentous-growth MAPK signaling pathway and hydrophobin genes through Tec1 and Ste12. However, functional validation is required to confirm direct regulation between both the transcription factors and the downstream genes. Full article

Background/Objectives: Cyclic dinucleotide stimulator of interferon genes (STING) agonists have emerged as potential agents in cancer immunotherapy, but their clinical applications are limited by relatively poor pharmacokinetic properties. Methods: A luciferase reporter assay was employed to screen delivery peptides capable of promoting cellular activating effect of cyclic dinucleotide STING agonists. The potent candidates were further confirmed by enzyme-linked immunosorbent assay (ELISA), real-time quantitative PCR (qPCR) and Western blotting analysis. Colon and melanoma cancer mouse models were used to examine the antitumor efficacy of the delivery peptides with cyclic GMP–AMP (cGAMP) as a therapeutic agents or vaccine adjuvant. Results: We identify a class of STING agonist delivery peptides that efficiently facilitate cytosolic delivery of cyclic dinucleotide STING agonists and promote STING activation by forming peptide coacervates. Intratumoral administration of Sti3-4A and cGAMP effectively suppressed tumor growth and promoted antitumor immune response. Furthermore, the conjugation of tumor-specific antigen peptides with Sti3-4A promoted cytosolic co-delivery of antigen peptides and cGAMP, thus significantly boosting APC maturation, antigen cross-presentation, and T cell responses to peptide antigens. Prophylactic and therapeutic immunization with the conjugated peptides and cGAMP inhibited tumor growth in multiple murine tumor models. Conclusion: These findings establish STING agonist delivery peptides as a versatile platform for cancer immunotherapy. Full article

This work introduces a trimming technique based on eTrim technology to minimize both the input-referred offset voltage and its temperature drift in the operational amplifiers. The proposed low-voltage op-amp utilizes the body effect to maintain a constant bandwidth across the rail-to-rail input common-mode range under low supply voltages. During input common-mode transitions, the current in the folded cascode stage remains stable, ensuring a robust output stage. Furthermore, a specialized gain-boosting structure enhances the low-frequency gain while preventing occasional latch-up during low-voltage power-up. A pin-multiplexing scheme is employed for trimming data input, thereby eliminating the need for dedicated trimming pins and mitigating post-package parameter variations. At room temperature, a constant-current injection mechanism reduces the DC offset to microvolt levels. At high temperature, temperature-compensated current injection cancels the first-order drift component. Implemented in a low-voltage operational amplifier, post-layout simulation results demonstrate that with a 100-pF capacitive load, the amplifier achieves a gain–bandwidth product exceeding 10 MHz, a low-frequency gain greater than 140 dB, and an input-referred noise of 2.54 µVp-p for the P-channel input and 3.95 µVp-p for the N-channel input. The trimming process reduces the residual offset to the microvolt range and effectively suppresses offset drift, ensuring accurate offset compensation across the specified temperature range. Full article

Glucagon-like-peptide-1 receptor (GLP-1R) agonists are under development as new drugs to treat type 2 diabetes, liver disease, obesity and cardiovascular diseases. Some of these drugs are solely agonists of the GLP-1R. It turned out that their benefit could be improved when they also stimulated the glucagon receptor (GCGR) and/or the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR). Stimulation of GLP-1R in cell cultures but also in neonatal atrial and/or ventricular cardiomyocytes and adult atrial cardiomyocytes raised the activity of adenylyl cyclase and thus augmented the 3’,5’cyclic adenosine monophosphate (cAMP) levels. We discuss here the acute contractile effects of such agonists on isolated human atrial and ventricular cardiac preparations from failing and non-failing hearts. We address the receptors involved, GLP-1R expression in various cardiac regions of the human heart, single and multiple receptor agonists and the post-receptor signal transduction system of the GLP-1R in the human heart. Some of the new drugs addressed are still in the early phases of clinical development. We critically discuss the experimental and clinical data available and we also define research needs for experimental and clinical studies. Full article

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway serves as a central innate immune signaling axis in host defense against DNA virus infections, and RNA viruses have also evolved diverse strategies to counteract this pathway. Encephalomyocarditis virus (EMCV), a zoonotic RNA virus, utilizes its 2C protein to antagonize RIG-I-like receptor-mediated type I interferon signaling and induce autophagic degradation of calcium binding and coiled-coil domain 2, thereby evading host antiviral immunity. However, the precise molecular mechanism by which EMCV 2C protein modulates the cGAS-STING pathway remains incompletely understood. Herein, we show that EMCV infection reduces the expression of cGAS and STING proteins, and its 2C protein significantly suppresses the production of IFN-β triggered by poly(dA:dT) or viral infection, as well as the mRNA expression of interferon-stimulated genes. Mechanistically, 2C protein binds to STING via its ATPase domain and facilitates K48-linked polyubiquitination and proteasomal degradation of STING, while dominantly interfering STING translocation to the Golgi apparatus and the formation of STING-TBK1-IRF3 complex, thereby blocking STING-mediated IFN-β signal transduction at multiple levels. This study reveals a novel mechanism by which the EMCV 2C protein suppresses the host antiviral response by targeting STING and promoting its ubiquitination and degradation. This finding deepens understanding of the immune evasion mechanism of EMCV and provides a theoretical foundation for the development of antiviral therapies targeting the 2C protein of picornaviruses. Full article

The increasing prevalence of multidrug-resistant (MDR) pathogens, particularly avian pathogenic Escherichia coli (APEC) and methicillin-resistant Staphylococcus aureus (MRSA), poses a severe threat to the breeding industry and human health. To develop novel antibiotic alternatives, we adopted a “converting virulence into therapy” strategy by leveraging the type VI secretion system (T6SS) of the APEC strain ACN17-20. Guided by the structural analysis of T6SS Protein 00145, we rationally designed a series of amphipathic α-helical polypeptides. Among them, polypeptide A7 emerged as a lead candidate, exhibiting potent broad-spectrum antibacterial activity with negligible cytotoxicity against mammalian cells. Mechanistic studies revealed that A7 exerts a rapid bactericidal effect through a dual mode of action: physical disruption of bacterial membrane integrity leading to cytoplasmic leakage, and induction of lethal oxidative stress via reactive oxygen species (ROS) accumulation. Furthermore, A7 demonstrated excellent efficacy in eradicating pre-formed bacterial biofilms, addressing the challenge of persistent infections in breeding environments. In a mouse sepsis model induced by APEC and MRSA, A7 treatment significantly improved survival rates (60–80%), reduced bacterial loads in vital organs, and attenuated the systemic cytokine storm (TNF-α and IL-1β), thereby alleviating immune-mediated tissue damage. In conclusion, this study identifies polypeptide A7 as a safe therapeutic agent with a dual mechanism of action, providing a promising strategy to combat MDR infections and reduce antibiotic dependence. Full article

Nicotinamide adenine dinucleotide (NAD⁺) is essential for maintaining homeostasis in all types of cells, including endothelium, and depletion of its pool can impair bioenergetics and stress response, contributing to cardiovascular disorders. Nicotinamide riboside (NR) effectively restores the intracellular NAD⁺ pool, supporting endothelial integrity, but the molecular mechanisms remain incompletely elucidated, particularly regarding extracellular adenine nucleotide catabolism, purinergic signaling, and their effects on immune cell adhesion. In this study, we aimed to investigate the effects of NR on intracellular nucleotides, extracellular adenine nucleotide catabolism, and adhesive properties in the cultured murine (H5V) and human (HMEC-1) microvascular endothelial cell line. We demonstrated that NR treatment significantly increased intracellular NAD⁺ concentrations without changes in the energy status of endothelial cells. We also showed that NR treatment accelerated extracellular hydrolysis of ATP and AMP and decreased the rate of adenosine deamination in endothelial cells. Moreover, we observed CD73 activity and adenosine-related reduced adhesion of T-lymphocytes, monocytes and platelets to the NR-treated endothelial monolayer. Our findings highlight a previously unrecognized role of NR in maintaining endothelial homeostasis, showing that NR is not only a potent intracellular NAD⁺ booster in endothelial cells but also affects extracellular nucleotide metabolism in a way that promotes cytoprotective adenosine formation. Full article

Payment channel networks enable scalable off-chain payments, but their practical deployment remains constrained by a persistent tension among routing efficiency, liquidity visibility, transaction privacy, and settlement security. Existing multipath routing mechanisms can improve payment success under fragmented liquidity, yet they often expose sensitive balance information, leak structural features of payment routes, and enlarge the attack surface for probing, channel exhaustion, and selective forwarding. This paper presents a novel framework, Adaptive Multipath Proofs (AMPs), for privacy protection and security in payment channel networks. The core idea is to bind multipath routing decisions with lightweight zero-knowledge verifiability, allowing intermediate nodes to validate path feasibility, fragment consistency, and settlement constraints without learning exact channel balances, the complete payment amount, or the global route structure. AMP integrates three mechanisms: a hidden-liquidity feasibility proof that supports privacy-preserving route selection, an adaptive payment-splitting strategy that dynamically determines fragment allocation according to network congestion and balance uncertainty, and a proof-coupled settlement guard that enforces atomicity and timeout consistency across all payment fragments. Together, these mechanisms reduce information leakage while preserving robust payment execution under dynamic network conditions. Experimental evaluation on real Lightning Network topologies and synthetic stress scenarios demonstrates that AMP significantly lowers balance disclosure and endpoint inference risk, improves payment completion under skewed liquidity distributions, and introduces only moderate computational and communication overhead. The results indicate that adaptive proof-carrying multipath routing offers a practical and effective direction for building secure, privacy-preserving, and high-success payment channel networks. Full article