Search Results (566)

Endometriosis is increasingly recognized as a chronic systemic disorder extending beyond the classical estrogen-dependent paradigm, integrating metabolic, immune, fibrotic, and nociceptive pathways that sustain lesion persistence and refractory pelvic pain. We propose a mechanistic, translational hypothesis in which tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, may modulate four interconnected pathological axes of refractory endometriosis—Warburg-type metabolic reprogramming with lactate accumulation, peritoneal immune dysfunction, NF-κB/NLRP3/TGF-β1-driven inflammatory–fibrotic remodeling, and persistent nociceptive sensitization—through three convergent molecular nodes: AMPK-associated signaling, GLP-1 receptor activity in peritoneal macrophages and spinal microglia, and the NF-κB/NLRP3/TGF-β1 axis. Particular emphasis is placed on the concept of “peritoneal incretin deficiency”, characterized by reduced peritoneal GLP-1 concentrations and increased expression of incretin-degrading proteases. This concept currently rests on a single, non-replicated case–control study, and the broader mechanistic chain is supported largely by indirect evidence extrapolated from adjacent inflammatory, metabolic, and neuroimmune disease models rather than by endometriosis-specific data. Direct experimental or clinical validation in endometriosis-specific models is currently absent. Accordingly, this article represents a hypothesis-generating framework rather than evidence of established efficacy, or a clinical treatment recommendation, intended to guide future mechanistic and prospective clinical investigation of incretin-based modulation as a potential adjunctive strategy in refractory endometriosis. Full article

Earthworms possess a highly developed innate immune system based on the coordinated activity of coelomocytes and humoral factors present in the coelomic fluid. These immune components play a central role in host defence against pathogens, maintenance of physiological homeostasis, and adaptation to environmental stressors. Coelomocytes exhibit remarkable functional and morphological diversity, including participation in phagocytosis, encapsulation, extracellular trap formation, cytotoxic responses, wound healing, and regulation of oxidative and osmotic stress. In addition, coelomic fluid contains numerous biologically active molecules, such as lysenin, coelomic cytolytic factor 1, perforin, serine proteases, lysozyme, antimicrobial peptides, and pattern recognition receptors, which contribute to cellular and humoral immune responses. Recent studies have demonstrated that earthworm coelomocytes are highly sensitive to environmental pollutants, including heavy metals, pesticides, nanomaterials, and microplastics, highlighting their importance in ecotoxicological research and soil biomonitoring. Furthermore, antifungal, antimicrobial, anti-inflammatory, antipyretic, and cytotoxic activities associated with coelomocytes and coelomic fluid suggest promising applications in agriculture, biotechnology, and pharmaceutical research. This review summarises current knowledge regarding the classification, characteristics, immune functions, toxicological responses, and applied significance of earthworm coelomocytes and coelomic fluid, with particular emphasis on their role in environmental monitoring and potential biomedical applications. Full article

Protease-activated receptor 1 (PAR1), a G protein-coupled receptor, plays a central role in coordinating multiple phases of cutaneous wound healing, including hemostasis, cell proliferation, migration, and extracellular matrix remodeling. Despite its therapeutic potential, PAR1-selective positive allosteric modulators (PAMs) remain limited. Here, we characterized the wound healing efficacy of gestodene, a third-generation progestin previously identified as a selective PAM of PAR1. Gestodene exhibited no intrinsic agonist activity but selectively potentiated PAR1-activating peptide (PAR1-AP)-induced calcium signaling without affecting PAR2 or PAR4 responses. Consistently, gestodene induced a concentration-dependent leftward shift in the PAR1-AP dose–response curve. Notably, gestodene enhanced PAR1-dependent cell proliferation, migration, and ERK1/2 activation, effects abolished by PAR1 knockout or pharmacological inhibition with vorapaxar in human keratinocytes (HaCaT) and dermal fibroblasts (HDF). Gestodene also potentiated the expression of wound healing-associated genes, including matrix metalloproteinases (MMP-1, -2, -3, -10), fibronectin, and type I collagen (COL1A1). In a murine wound model, topical administration of gestodene accelerated wound closure, achieving complete re-epithelialization by Day 8 and significantly enhancing collagen deposition, effects reversed by vorapaxar. Collectively, these findings demonstrate that gestodene accelerates cutaneous wound healing through PAR1-selective positive allosteric modulation and supports its potential as a drug repositioning candidate for wound repair. Full article

Cucurbitacin B belongs to a group of tetracyclic triterpenoids and exerts a number of biological effects, including anti-inflammatory and anticancer activities. We previously demonstrated that cucurbitacin B down-regulated tumor necrosis factor (TNF) receptor 1 (TNF-R1) expression and prevented activation of the transcription factor nuclear factor κB in response to a TNF-α stimulation. The present study shows that cucurbitacin B promoted the ectodomain shedding of TNF-R1 by generating a soluble form that accumulated in the culture medium of human lung adenocarcinoma A549 cells. Of the eight tetracyclic and pentacyclic triterpenoids consisting of an α,β-unsaturated carbonyl group that were examined, only cucurbitacin B promoted TNF-R1 ectodomain shedding. Cucurbitacin B-induced TNF-R1 shedding was attenuated by TNF-α protease inhibitor 2 and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126, but not by the p38 MAPK inhibitor SB203580 or the c-Jun N-terminal kinase (JNK) inhibitor SP600125. Consistent with these results, cucurbitacin B promoted the rapid phosphorylation of rapidly accelerated fibrosarcoma 1 (RAF1) and ERK, but exerted minimal effects on the phosphorylation of p38 MAPK and JNK. Collectively, these results demonstrate that cucurbitacin B selectively activated the RAF1-MEK-ERK pathway, which was essential for TNF-R1 ectodomain shedding. Full article

Tumor cell migration relies on the integration of extracellular matrix (ECM) remodeling, cell surface signaling regulating cytoskeleton dynamics, and epithelial-to-mesenchymal transition (EMT). Clusterin (CLU), a secreted glycoprotein, is involved in extracellular proteostasis and is known to interact with members of the LDL receptor family, including low-density lipoprotein receptor-related protein 1 (LRP1). Beyond its canonical chaperone activity, CLU is involved in several biological processes, including cell survival, apoptosis, tissue remodeling, inflammation and cancer progression. On the other hand, the membrane type 1 matrix metalloproteinase (MT1-MMP), functionally linked to CD44 and LRP1, represents a key membrane-associated molecule that may control cell adhesion and receptor-mediated uptake of ECM ligands and proteases. In this article, we critically highlight a hypothetical model in which secreted CLU (sCLU) may function as the central player of a dynamic membrane-associated network integrating proteolysis, endocytosis, and intracellular signaling. Based on recent literature findings and STRING analyses, LRP1, MT1-MMP, CD44, and cell surface matrix components, such as proteoglycans (PGs) and integrins, are likely to be involved. By coordinating this membrane-associated molecular crosstalk, sCLU may integrate ECM remodeling with cytoskeletal dynamics and EMT-related programs related to invasive behavior. Overall, this framework highlights a potential mechanism through which sCLU may contribute to tumor cell plasticity and aggressiveness, suggesting new avenues for therapeutic intervention. Full article

Urokinase plasminogen activation system regulates the activation of plasminogen to produce the ubiquitous extracellular protease plasmin. It is involved in different physiological and pathophysiological processes, which involve tissue reorganization, wound healing, cell migration and invasion, etc. The system comprises urokinase plasminogen activator, an extracellular protease, its inhibitor plasminogen activator inhibitor PAI1 and urokinase receptor, uPAR. The system is regulated at the level of transcription and posttranscriptionally, and the net urokinase activity depends on the balance between urokinase and PAI1. Promoters of urokinase, PAI1 and uPAR are regulated through different signaling pathways, mostly MAP kinases and TGFβ signaling. Urokinase promoter is complex and mostly depends on strong enhancers containing AP1/ETS binding sites for different combinations of AP1 dimers, whose members are phosphorylated through ERK, JNK and p38 kinases. The PAI1 promoter is mainly regulated through TGFβ signaling, which can use both Smad and AP1-dependent transcription. The uPAR promoter also depends on AP1 signaling, in addition to other transcription factors activated through other pathways. Although activated through common pathways, each of the promoters has specific regulation as a consequence of a signaling network, which enables fine-tuning of the system and urokinase activity according to the physiological needs. Full article

The innate immune system, particularly the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway, is a major early defense barrier against influenza A virus infection. However, excessive immune responses can trigger lethal cytokine storms and severe immune-mediated pathology. In this study, we performed a genome-wide CRISPR/dCas9 gene activation screen in human lung epithelial (A549) cells by using an A/Puerto Rico/8/1934 (H1N1) reporter virus, and identified the ubiquitin-specific protease USP17L13 as a novel negative regulator of innate immunity that promotes influenza virus replication. Overexpression of USP17L13 significantly enhanced the replication of multiple subtypes of influenza viruses in A549 cells, including a human pandemic H1N1 virus, seasonal H3N2 viruses, as well as a globally circulating clade, 2.3.4.4b, of the highly pathogenic avian H5N1 virus. Transcriptomic analysis demonstrated that USP17L13 suppresses host antiviral defenses by downregulating nuclear factor kappa B (NF-κB) signaling and arachidonic acid metabolism, while upregulating pathways associated with ribosomal translation and oxidative phosphorylation to facilitate viral production. Mechanistically, USP17L13 attenuates the host interferon (IFN) response by promoting the degradation of the key viral RNA sensors, RIG-I, and melanoma differentiation-associated protein 5 (MDA5). Further analysis revealed that USP17L13 is inducible by type I and type II interferons as well as inflammatory cytokines, suggesting that it may act as a negative-feedback regulator to limit excessive inflammation. Collectively, our findings identify USP17L13 as a previously unrecognized proviral host factor and provide new insight into how host deubiquitinases shape influenza virus-host interactions, with potential implications for host-directed approaches to controlling excessive inflammation during viral infection and improving influenza vaccine production. Full article

Background: A major challenge in antiviral development is the identification of novel virus–host interactions while ensuring therapeutic efficacy and safety. These challenges have renewed interest in phytochemicals derived from medicinal plants as alternative antiviral agents. Objectives: In this study, we investigated the antioxidant, antiviral, and immunomodulatory properties of a Mediterranean Urtica dioica extract (UdE) against SARS-CoV-2 using chemical, biochemical, and in vitro approaches. Methods: The physicochemical properties of UdE were characterized using microtiter assays and HPLC analysis. Cytocompatibility was evaluated in HEK293T, Vero E6, Caco-2, and Calu-3 cell lines while antioxidant activity was assessed using both chemical and cell-based assays. Antiviral activity was evaluated by assessing inhibition of SARS-CoV-2 receptor binding domain (RBD)–ACE2 interaction using ELISA, inhibition of SARS-CoV-2 main protease (Mpro) activity via FRET assay and inhibition of viral entry using SARS-CoV-2 S1 pseudovirus neutralization assay. Results: UdE (100 µg/mL) inhibited RBD–ACE2 binding by 94% and suppressed Mpro activity by 74%, while reducing moderate but significant inhibition of pseudovirus entry (33.6%) at 300 µg/mL dose level in ACE2 expressing HEK293T cells. Immunomodulatory analysis revealed significant suppression of IL-1β and IL-6 production, accompanied by increased TNF-α and IL-8 levels. Conclusions: Collectively, these findings highlight that UdE exhibits multi-target in vitro antioxidant, antiviral, and immunomodulatory activity against SARS-CoV-2; therefore, UdE represents a promising bioactive extract for the management of SARS-CoV-2 infection. Full article

Protease-activated receptor-1 (PAR-1) is a key regulator of mesenchymal stem cell (MSC) migration and tissue integration. Dabigatran, a direct thrombin inhibitor widely used as a non-vitamin K oral anticoagulant (NOAC), may affect PAR-1-mediated signaling pathways. This study investigated the effects of dabigatran on cell viability, apoptosis, and PAR-1 activity in adipose-derived MSCs (ADMSCs) in vitro. ADMSCs were exposed to five concentrations of dabigatran etexilate with thrombin activation. Cell viability was assessed using the MTT assay, apoptosis and morphological changes were evaluated via acridine orange/propidium iodide staining, and PAR-1 expression was analyzed by immunofluorescence. Results showed that high dabigatran concentration significantly reduced cell viability and induced apoptotic morphological changes. In contrast, lower, non-cytotoxic concentrations preserved normal fibroblastic morphology and maintained cell viability while reducing PAR-1 surface expression compared with thrombin-activated controls. These findings indicate that dabigatran at non-cytotoxic doses can modulate PAR-1 activity without compromising ADMSC survival. In conclusion, dabigatran influences MSC-related cellular functions beyond its anticoagulant properties. Full article

Angiotensin-converting enzyme (ACE) inhibitors (ACEis) are one of the most successful drug classes for the treatment of hypertension and the prevention of its cardiovascular complications. ACE activates the pressor hormone angiotensin but also inactivates the vasodilator peptide bradykinin (BK). A rare side effect of ACEis, angioedema (AE), has been proposed to result from pro-inflammatory effects of BK. Novel considerations are offered in this debate: (1) the bradykinin B2 receptor antagonist icatibant has had an inconsistent effect on ACEi-associated AE, but its potency and duration of action are much inferior to those of a novel nonpeptide antagonist of this receptor, deucrictibant. (2) Tissue kallikrein (KLK-1) is an effective kininogenase, particularly abundant in the salivary glands, possibly related to orofacial presentation of ACEi-induced AE. (3) The strongly regulated human kinin B1 receptor, optimally responsive to Lys-des-Arg⁹-BK, is functionally compartmentalized with KLK-1 which produces Lys-BK from kininogens. Chronic treatment with ACEi drugs in laboratory animals induces the expression of vascular B1R that mediates vasodilation. Therefore, ACEi-AE may be largely or completely initiated by KLK-1. Inhibitors of this protease or combined antagonists of both kinin receptor subtypes may be useful for the management of this condition. Full article

Background: Aging is accompanied by a progressive decline in skeletal muscle regeneration, largely due to impaired myogenic differentiation. The proprotein convertase FURIN is a key protease responsible for activating several signaling molecules, including precursors of NOTCH receptors, which regulate cell fate and differentiation. In this study, we investigated whether age-associated downregulation of FURIN contributes to impaired NOTCH2/3 signaling and myogenic function. Methods: An initial bioinformatics analysis of public scRNA-seq data from Genotype-Tissue Expression (GTEx) project indicated age-related expression of genes in the NOTCH signaling pathway. In vitro verification used early- and late-passage C2C12 myoblasts as a model of muscle cell aging to compare the expression of these genes. Late-passage C2C12 cells were transiently transfected with FURIN plasmid to assess restoration of differentiation potential, quantified by the fusion index, myogenic marker expression, and morphology. Results: Expression of FURIN, NOTCH2 and NOTCH3 was negatively correlated with age, whereas GZMB increased with age in GTEx dataset. Late-passage myoblasts exhibited impaired myotube formation, reflecting age-associated loss of myogenic capacity. Restoration of FURIN expression in aged myoblasts was associated with reduced GZMB levels, increased expression of embryonic myosin heavy chain IGF1, and partial recovery of myogenic differentiation and myotube formation. Conclusions: These findings suggest that age-associated loss of FURIN contributes to impaired NOTCH2/3 pathways and myogenic dysfunction. Overexpression of FURIN partially rescues the myogenic phenotype and increases expression of early myogenic markers in aged cells, identifying FURIN as a potential regulator of muscle regenerative capacity during aging. We suggest FURIN as a promising candidate target for further investigation into the mechanisms driving aging or age-related decline. Full article

Myocardial ischemia–reperfusion injury (MIRI) significantly compromises the clinical benefits of revascularization and constitutes a central pathological mechanism worsening prognosis in myocardial infarction patients. Accordingly, dissecting the molecular mechanisms underlying MIRI and formulating effective therapeutic interventions are of great clinical significance. Lycium barbarum polysaccharide (LBP), the primary active constituent of Lycium barbarum, has garnered considerable attention in the prevention and treatment of cardiovascular diseases due to its anti-inflammatory, antioxidant, vasomotor function-improving, and antithrombotic properties. This study aims to investigate the ability of LBP to alleviate MIRI, with a specific focus on its role in modulating the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome. Myocardial ischemia/reperfusion (I/R) models in rats and hypoxia/reoxygenation (H/R) models in H9c2 cells were established. Myocardial injury and the therapeutic effect of LBP were evaluated by 2,3,5-Triphenyl tetrazolium chloride (TTC) staining, Hematoxylin-eosin (H&E) staining, Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) staining, and Enzyme-linked immunosorbent assay (ELISA). To elucidate the specific mechanism underlying LBP against MIRI, an Nrf2-overexpressing cell line was generated in H9c2 cells, and pharmacological inhibition of Nrf2 with ML385 was applied for complementary validation. The effects of LBP on H/R-induced oxidative stress, inflammatory response (IL-18, IL-1β), and pyroptosis-related protein expression (NLRP3, apoptosis associated speck-like protein containing a CARD (ASC), cysteine-dependent aspartate-specific proteases (caspase)-1, Gasdermin D (GSDMD)) were systematically evaluated. LBP administration conferred robust cardioprotection in I/R rats, as evidenced by a significant reduction in myocardial infarct size, improved preservation of myocardial fiber architecture, and attenuated leakage of cardiac injury biomarkers (lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB)). Mirroring these in vivo findings, LBP pretreatment effectively shielded H9c2 cardiomyocytes from H/R insult, markedly enhancing cell viability while curtailing reactive oxygen species (ROS) accumulation and apoptotic activation. A pivotal finding was the pronounced downregulation of Nrf2 in the H/R group, a deficit that was conclusively reversed by LBP treatment. To decisively establish a causal role for Nrf2, we employed a loss-of-function approach; Nrf2 inhibition completely abrogated the protective benefits of LBP, culminating in exacerbated tissue damage, a surge in ROS, and the upregulation of key pyroptosis effectors (NLRP3, ASC, caspase-1, GSDMD). Conversely, a complementary gain-of-function experiment demonstrated that Nrf2 overexpression alone was sufficient to mimic LBP’s effects, significantly blunting H/R-induced ROS production and pyroptosis. LBP alleviates MIRI by inhibiting pyroptosis through activating the Nrf2/NLRP3 axis, thus representing a promising therapeutic candidate for ischemic heart disease with the potential to improve patient outcomes. Full article

Vibrio alginolyticus is a foodborne pathogen commonly found in seafood and freshwater products, causing human illness through the consumption of tainted seafood. Small non-coding RNAs (sRNAs) take effect on the stability and translation of their target mRNAs by base-pairing, thereby quickly altering bacterial physiology and pathogenicity at the post-transcriptional level. This work constructed a label-free in-frame deletion mutant and a complement strain of micX, a cell-density-associated sRNA in V. alginolyticus. The ΔmicX mutant exhibited reduced growth and a reduction in the synthesis of exopolysaccharides, biofilm, and alkaline serine protease. A TMT-based quantitative proteomic analysis comparing ΔmicX with the wild-type strain identified 900 differentially expressed proteins, comprising 376 that were upregulated and 524 that were downregulated. The upregulated proteins are primarily associated with porin activity, transmembrane signaling receptor function, and the two-component system. The downregulated proteins are mainly engaged in processes including biofilm formation, cellular communication, and transmembrane transport activity. Of note, the expression levels of proteins involved in the type VI secretion system, exopolysaccharide synthesis, mannose-sensitive hemagglutinin type IV pili (MSHA), and biofilm formation were significantly reduced in the absence of micX. Furthermore, the expression levels of proteins associated with quorum sensing (particularly LuxR and AphA) changed significantly in the ΔmicX vs. WT comparison. These findings strengthened comprehension of the novel sRNA regulatory network and established a theoretical foundation for additional investigations into the virulence of V. alginolyticus. Full article

Alpha-2-macroglobulin (α₂M) is a conserved plasma glycoprotein traditionally known for its broad-spectrum protease inhibitory activity. However, emerging evidence indicates that its activated form, α₂M*, generated via proteolytic cleavage or nucleophilic attack, functions as a versatile signaling ligand. By engaging specific cell-surface receptors, most notably low-density lipoprotein receptor-related protein 1 (LRP1) and glucose-regulated protein 78 (GRP78), α₂M* orchestrates a diverse array of intracellular programs, including the PI3K/Akt/mTOR, MAPK/ERK, and JAK/STAT cascades, as well as mechanosensitive YAP/TAZ signaling. These pathways collectively govern fundamental cellular processes such as proliferation, metabolic reprogramming, cytoskeletal remodeling, and inflammatory adaptation across various cell types, including macrophages, cardiomyocytes, and malignant cells. Altogether, this review synthesizes current knowledge on α₂M activation, structural transitions, receptor interactions, and downstream signaling, highlighting the expanding functional landscape of α₂M* as a potent regulator of intracellular communication with implications for physiology and disease. Full article

Background. NOTCH receptors play a pivotal role in carcinogenesis. Upon ligand binding, a cascade of proteolytic cleavages mediated by ADAM proteases and the γ-secretase complex activates the receptor, ultimately releasing the NOTCH intracellular domain (NICD). NICD translocates to the nucleus, where it regulates gene expression. This review mainly aims to evaluate γ-secretase inhibitors (GSIs) as anticancer agents in preclinical and clinical settings, with a focus on their ability to block tumor progression, target cancer stem cells, and overcome resistance to standard therapies. Methods. A systematic search was conducted in the ISI Web of Science, PubMed, and Scopus databases, following PRISMA guidelines. The review included preclinical in vitro and in vivo studies, as well as clinical trials, investigating GSIs, either as monotherapy or in combination with other treatments, in TNBC, metastatic melanoma, PDAC, gastric cancer, and NSCLC. Exclusion criteria included duplicates, non-English articles, studies published before 2010, studies on non-cancer conditions, research unrelated to NOTCH signaling, and studies outside the selected cancer types. Overall, 69 articles were included and categorized into the five types of cancer analyzed (20 on NSCLC, 22 on TNBC, 11 on metastatic melanoma, 7 on GC, and 9 on PDAC). Of these, 60 studies corresponded to preclinical research in the types of cancer, and 9 studies corresponded to clinical trials in the types of cancer except for GC. Two independent authors screened and extracted relevant data, with disagreements resolved by the corresponding author. Findings were synthesized qualitatively across cancer types under study. Results. This review summarizes therapeutic advances involving GSIs in cancers driven by oncogenic NOTCH signaling, based on the 69 articles included. Preclinical studies show that GSIs synergize with chemotherapy and radiotherapy, particularly in NSCLC, melanoma, and TNBC, and block EMT, overcome therapeutic resistance, and improve prognosis. Commonly used GSIs include DAPT and RO4929097, which enhance the efficacy of agents, such as gemcitabine (PDAC), paclitaxel, osimertinib, erlotinib, and crizotinib (NSCLC), and 5-FU (gastric cancer, TNBC). Promising strategies include combining GSIs with SAHA, ATRA, CB-103, and other NOTCH signaling targeting molecules, either alone or with chemo- and radiotherapy. Clinical trials with GSIs, however, remain limited. RO4929097 is the most extensively tested GSI in clinical settings. PDAC trials combining GSIs with gemcitabine showed no benefit; melanoma trials yielded modest outcomes; and TNBC trials demonstrated partial responses to GSIs but overall low efficacy and significant adverse events. Discussion and Conclusions. Despite encouraging preclinical evidence, clinical trials with GSIs have underperformed, largely due to tumor heterogeneity, dosing limitations, and the non-selective nature of γ-secretase inhibition. Other NOTCH inhibitors, such as DLL4 antibodies, also resulted in partial responses and secondary effects. Future strategies should prioritize receptor-specific NOTCH inhibitors, patient stratification based on NOTCH pathway activation, and optimized combination regimens. Emerging approaches include integrating immunotherapy with advanced technologies such as CRISPR, CAR-T cells, and bispecific antibodies, as well as targeted delivery systems to enhance efficacy and reduce toxicity. Additional research directions include addressing the tumor microenvironment and EMT-driven resistance, elucidating the mechanisms of immune evasion, and inhibiting tumor angiogenesis. Finally, leveraging artificial intelligence and big-data-driven personalized medicine, including sex-specific considerations, will be essential for improving patient outcomes. Full article