Search Results (739)

Type-2 Diabetes Mellitus (T2DM) is related to cardiac arrhythmias. The stellate ganglion (SG), part of the sympathetic nervous system, regulates heart function. Within the SG, satellite glial cells (SGCs) have gap junction channels (Cx43). Increased Cx43 permeability induces SGC depolarization and activates the PKC-MAPK14-ADAM17 signaling pathway, releasing some endogenous factors that stimulate nearby cardiac postganglionic sympathetic neurons (CPSN). This study investigated the activation of the PKC-MAPK14-ADAM17 signaling pathway in T2DM SGs and SGCs as a novel mechanism of sympathetic overactivation. A total of 56 Sprague-Dawley rats were randomly assigned to sham and T2DM groups, and T2DM was induced using a high-fat diet combined with low-dose streptozotocin. Real-time RT-PCR, Western blot, and ELISA quantified mRNA/protein expression and enzymatic activity. The patch clamp technique assessed neuronal voltage-gated Ca²⁺ currents and action potentials, while electrophysiological recording measured cardiac sympathetic nerve activity (CSNA). T2DM rats exhibited marked upregulation of MAPK14, PKC-α, and ADAM17 mRNA/protein in the SG, alongside elevated enzymatic activities of PKC and ADAM17. T2DM also increased Ca²⁺ currents and neuronal excitability in the CPSN and induced the elevation of the CSNA. Upregulated PKC-MAPK-ADAM17 signaling in the SG might contribute to cardiac sympathetic overactivation in T2DM rats by enhancing the cell excitability of the CPSN. Full article

Neuropeptide FF (NPFF) belongs to the RF-amide peptide family and is homologous to gonadotropin-inhibitory hormone (GnIH). The NPFF precursor encodes two mature peptides, NPFF and NPAF (neuropeptide AF). Both peptides share the conserved C-terminal PQRFa motif. However, there is very limited information available on receptor cross-reactivity for NPFF and GnIH peptides in teleosts. As a first step, we cloned two cognate receptor genes for NPFF, designated as NPFFR2-1 and NPFFR2-2, in the flatfish species half-smooth tongue sole. Tissue distribution analysis revealed that npffr2-1 and npffr2-2 transcripts were present at high levels in the brain and pituitary gland, and at lower levels in some peripheral tissues. In vitro functional analysis indicated that NPFF significantly stimulated CRE-luc and SRE-luc activity in COS-7 cells expressing either NPFFR2-1 or NPFFR2-2. However, NPAF increased CRE-luc and SRE-luc activity only via NPFFR2-1. Moreover, NPFF exerted an inhibitory effect on NFAT-RE-luc activity in COS-7 cells transfected with NPFFR2-1, whereas NPAF elicited an evident stimulatory effect via NPFFR2-2. Neither GnIH1 nor GnIH2 altered CRE-luc activity in COS-7 cells transfected with NPFFR2-1 or NPFFR2-2; however, forskolin-induced CRE-luc activity was significantly reduced by these two peptides. Furthermore, neither basal nor forskolin-stimulated CRE-luc activity was modified by NPFF or NPAF in COS-7 cells expressing the GnIH receptor (GnIHR). Both GnIH1 and GnIH2 significantly increased SRE-luc activity in COS-7 cells expressing NPFFR2-1 or NPFFR2-2, and vice versa. Taken together, our findings provide novel evidence that both NPFF and GnIH peptides could exert their functions via three different receptors, and that PKA, PKC, and Ca²⁺ signaling pathways are potential mediators. Full article

Artemisia indica Willd., a traditional medicinal and dietary herb, has been widely recognized for its diverse bioactivities. This study aimed to evaluate the effects of Artemisia indica Willd. aqueous extract (AAE) on dysglycemia and dyslipidemia. HPLC–ESI–MS/MS analysis identified 4,5-dicaffeoylquinic acid as the major active constituent of AAE. BALB/cByJNarl mice subjected to a high-fat diet (HFD) and streptozotocin (STZ) injection were supplemented with AAE for 6 weeks. To elucidate the underlying mechanisms, we examined multiple metabolic pathways, including oxidative stress, lipid metabolism, and the polyol pathway. AAE administration attenuated fasting blood glucose and reduced fructosamine levels and also ameliorated protein kinase C α (PKC-α) and nuclear factor kappa B (NF-κB) expression. Histopathological evaluation showed that AAE reduced lipid accumulation by modulating sterol regulatory element-binding protein 1 (SREBP-1) and fatty acid synthase (FAS) expression. Additionally, AAE inhibited polyol pathway activation and restored antioxidant enzyme activities. Collectively, these findings indicate that AAE modulates glucose and cholesterol metabolism, attenuates oxidative stress, and improves metabolic homeostasis, supporting its potential as a natural herbal therapeutic agent. Full article

Glioblastoma multiforme (GBM) exhibits remarkable resistance to therapy, mainly due to its capacity to modulate regulated cell death pathways. Among these, apoptosis and autophagy are dynamically interconnected, determining cell fate under therapeutic stress. The interaction between beclin-1 and Bcl-2 proteins may represent a key molecular switch that controls whether glioma cells undergo survival or death. This review highlights the crucial role of the Bcl-2:beclin-1 complex in controlling apoptosis–autophagy axis in GBM, emphasising how survival signalling networks, including PI3K/AKT/mTOR, Ras/Raf/MEK/ERK, and PLCγ1/PKC pathways regulated by the TrkB receptor, modulate this balance. We summarise recent insights into how these pathways coordinate the shift between apoptosis and autophagy in glioma cells, contributing to drug resistance. Furthermore, we highlight how modulating this crosstalk can sensitise GBM to conventional and emerging therapies. Integrating new concepts of cell death reprogramming and systems-level signalling analysis, we propose that targeting the Bcl-2:beclin-1 complex and its upstream regulators could overcome the adaptive plasticity of glioblastoma multiforme and open new directions for combination treatment strategies. Full article

Apis cerana is an important native honey bee species in China, and its body size is closely related to its production performance and environmental adaptability. Prpk (TP53-regulating kinase) has been confirmed to regulate cell growth and proliferation, thereby influencing body size development. However, its function in honey bees remains unclear. In this study, the protein structure and function of PRPK were analyzed, and the expression characteristics were examined at different developmental stages and tissues in Hainan Chinese honey bee and Aba Chinese honey bee. The molecular weight of this protein was 30.3 kDa, and the predicted isoelectric point was 9.13, and it had a conserved PKc_like superfamily domain. The sequence of PRPK was highly conserved from insects to mammals and fungi. The results of RT-qPCR showed that Prpk expression significantly increased during honey bee pupation, and its expression level was significantly higher in the larvae and early-stage pupae of the larger-bodied Aba Chinese honey bee. Additionally, Prpk exhibited the highest expression in the thoraces, suggesting its potential involvement in appendage development. This study indicated that Prpk may play a potential regulatory role in body size development in honey bees, providing a theoretical basis and candidate gene for elucidating the molecular mechanisms of body size formation and genetic improvement in honey bees. Full article

Advanced glycation end products (AGEs) are compounds that accumulate in hyperglycemic states, contributing significantly to the development of diabetes and its complications, including the exacerbation of periodontal disease. We hypothesized that AGEs affect the expression of inflammatory mediators in gingival cells, thus contributing to the increased severity of periodontitis observed in diabetic patients. Thus, we stimulated the gingival epithelial carcinoma-derived cell line, Ca9-22, with AGEs and examined their effect on the expression of prostaglandin E₂ (PGE₂) and its primary synthesizing enzyme, cyclooxygenase 2 (COX2), key inflammatory mediators in periodontitis. AGEs significantly increased the expression levels of COX2 (n = 6, p < 0.001) and the production of PGE₂ (n = 5, p < 0.05) compared to untreated control and bovine serum albumin (BSA) groups. The receptor for AGEs (RAGE) inhibitor FPS-ZM1 blocked the AGEs-stimulatory effects on COX2 (n = 7, p < 0.01), PGE₂ (n = 6, p < 0.001), and Toll-like receptor 4 (TLR4) expression (n = 7, p < 0.001). Furthermore, AGEs induced the phosphorylation of protein kinase C (p-PKC) via the TLR4 pathway (n = 7, p < 0.01). Crucially, AGEs enhanced NF-κB nuclear accumulation, which was inhibited by blocking either RAGE (n = 5, p < 0.0001) or TLR4 (n = 5, p < 0.0001). In conclusion, these findings demonstrate that AGEs increase PGE₂ production in Ca9-22 cells primarily through a signaling cascade involving RAGE and the TLR4-PKC-NF-κB pathway. Our results suggest TLR4 as a critical mediator that contributes to AGEs-induced inflammation. Full article

Background: Hypertension and its complications are a major global health problem, and natural compounds with vasorelaxant effects are being investigated as potential antihypertensive agents. Objective: This study aimed to determine whether rosmarinic acid (RA) induces vasorelaxation in the rat thoracic aorta and to elucidate the underlying mechanisms. Methods: Isolated thoracic aortic rings, with or without endothelium, were precontracted with phenylephrine and subsequently exposed to cumulative concentrations of RA. The roles of endothelium-derived factors, potassium channels, and calcium signaling were evaluated using selective pharmacological inhibitors and activators. In addition, the involvement of the AMPK pathway, adenylate cyclase/cAMP pathway, PKC signaling, β-adrenergic receptors, muscarinic receptors, and angiotensin II in RA-induced vasorelaxation was investigated. Results: RA induced a concentration-dependent vasorelaxation in endothelium-intact thoracic aortic rings (p < 0.001; pD₂ = 7.67 ± 0.04). The vasorelaxant effect of RA was attenuated in endothelium-denuded vessels (pD2: 5.26 ± 0.18). The relaxation response was significantly attenuated by inhibitors of the PI3K/Akt/eNOS/NO/cGMP pathway and by blockers of BK_Ca, IK_Ca, and Kv potassium channels (p < 0.001). Furthermore, RA markedly inhibited both extracellular Ca²⁺ influx and intracellular Ca²⁺ release from the sarcoplasmic reticulum (p < 0.001). RA incubation also significantly reduced the contractions induced by angiotensin II (Ang II) and by the PKC activator PMA (p < 0.001). Other tested pathways had no significant influence on the vasorelaxant effect of RA (p > 0.05). Conclusions: These findings demonstrate that rosmarinic acid induces both endothelium-dependent and endothelium-independent vasorelaxation in the rat thoracic aorta through activation of the PI3K/Akt/eNOS/NO/cGMP pathway, opening of BK_Ca, IK_Ca, and Kv potassium channels, and suppression of Ca²⁺ mobilization. Additionally, inhibition of PKC- and angiotensin II-mediated vascular contraction contributes to RA-induced vasorelaxation. RA may therefore have therapeutic potential in the management of hypertension. Full article

Soil salinization poses a major threat to plant growth and ecosystem sustainability. Zoysia japonica, a salt-tolerant turfgrass, shows promise for saline–alkali soil remediation, yet its metabolic adaptation mechanisms remain poorly understood. Here, we applied non-targeted liquid chromatography/mass spectrometry (LC/MS) metabolomics to compare the responses of salt-tolerant (accession 68) and salt-sensitive (accession 9) genotypes of Z. japonica under salt stress. The sensitive genotype exhibited stronger metabolic disruption, with 843 differentially accumulated metabolites (largely down-regulated), compared with 595 in the tolerant genotype (predominantly up-regulated). We identified a coordinated tolerance mechanism primarily centered on lipid remodeling and energy maintenance. The tolerant genotype enhanced membrane stability through the accumulation of saturated glycerophospholipids and an increased phosphatidylcholine/phosphatidylethanolamine (PC/PE) ratio, while maintaining phosphatidic acid (PA) homeostasis which may facilitate SOS-dependent Na⁺ efflux. It also mitigated oxidative damage by stabilizing diacylglycerol (DAG), thereby potentially limiting protein kinase C (PKC) overactivation. Furthermore, sustained cardiolipin and riboflavin metabolism supported mitochondrial energy production in the tolerant genotype. Together, these findings provide new insights into the early metabolic basis of salt tolerance in Z. japonica, suggesting a potential crucial role for PA-mediated regulation of SOS-dependent sodium sequestration during the initial phase of stress, and implying potential targets for breeding stress-resilient turfgrasses. Full article

Transient receptor potential canonical 6 (TRPC6) channels are promising drug targets for kidney, lung, and neurological diseases, making a detailed understanding of their regulation crucial to developing novel channel modulators with more precise modes of action. TRPC6 channels are commonly accepted as calcium-permeable, receptor-operated cation channels activated by diacylglycerol (DAG) downstream of phospholipase C (PLC) signaling. DAG, the endogenous activator of TRPC channels, also activates protein kinase C (PKC), which can phosphorylate TRPC6 and potentially modify its function. This study examined whether five putative PKC phosphorylation sites located in the C-terminus of TRPC6 affect channel gating. Using whole-cell patch-clamp recordings and utilizing photopharmacology with photoswitchable TRPC6 activators (OptoBI-1 and OptoDArG), we analyzed the activation, inactivation, and deactivation kinetics. Pharmacological modulation of PKC activity and strategic mutation of the phosphorylation sites—either to prevent or mimic phosphorylation—altered the current kinetics as well as the normalized slope conductances that were used to quantify differences in the curve progression of current–voltage relations, even when maximally induced current density amplitudes were unchanged. Our findings reveal activator-specific differences in TRPC6 current kinetics associated with C-terminal amino acid exchanges and PKC-dependent signaling, suggesting that phosphorylation-related mechanisms may fine-tune channel activity. Full article

Background/Objectives: Protein kinase C-δ (PKC-δ) is a pivotal regulator of cellular signalling, and its dysregulation contributes to oncogenesis. While certain isolated PKC-δ domains have been crystallised, the full-length architecture and interdomain interactions remain largely unresolved, limiting mechanistic insight and the design of selective modulators. We aimed to define the full-length, inactive conformation of PKC-δ and identify accessible, functionally relevant binding sites for ligand discovery. Methods: We generated a consensus structural model of full-length inactive PKC-δ using multi-template comparative modelling guided by established inactivity markers. Molecular docking was used to predict ligands targeting the C2 domain, which were subsequently validated in breast cancer cell models, including wild-type and C2 domain-overexpressing lines. Results: Analysis of the model revealed the architecture of the C2/V5 interdomain space, providing a structural rationale for regulation of the nuclear localisation signal (NLS). Docking identified two ligand classes: ligand 1 engaged a C2 domain surface oriented toward the C2/V5 pocket, while ligand 2 targeted the C2 domain phosphotyrosine-binding domain (PTD). Experimental validation in breast cancer cell models demonstrated that both ligands reduced cell viability; ligand 1 showed enhanced effects in C2-overexpressing cells, consistent with predicted accessibility, whereas ligand 2 partially counteracted the C2 domain-induced viability phenotype, likely via interference with PTD-mediated interactions. Conclusions: Full-length structural context is essential for identifying accessible, functionally relevant binding sites and understanding context-dependent kinase regulation. Integrating computational modelling with phenotypic validation establishes a framework for selective PKC-δ modulation, offering insights to guide ligand discovery, improve isoform selectivity, and inform strategies to mitigate kinase inhibitor resistance in precision oncology. Full article

Background/Objectives: Copper is an essential trace element for physiological processes related to reproduction, but its impact on the hypothalamic–pituitary–ovarian (HPOA) axis and its specific mechanism remain unclear. Methods: In vivo study: 21-day-old female Sprague Dawley (SD) rats were randomly assigned to five groups (n = 10 per group), with all groups fed a basal diet and supplemented with CuSO₄·5H₂O to achieve copper ion concentrations of 0, 15, 30, 45, or 60 mg/kg in the diet. During the second phase of proestrus, blood samples, hypothalamic tissues, pituitary tissues, and ovarian tissues were collected. In vitro study: Primary mixed hypothalamic neurons were isolated and cultured from fetal SD rats on embryonic day 17. After identification by NSE immunofluorescence staining, six copper ion concentration groups (0, 15.6, 31.2, 46.8, 62.4, and 78 μmol/L) were established. The optimal copper concentration for cell viability and GnRH secretion was screened using CCK-8 assay (Sangon, Shanghai, China) and ELISA (Mlbio, Shanghai, China). On this basis, the cells were treated with different concentrations of PKC agonist (PMA) and PKC inhibitor (chelerythrine). Cell viability was evaluated by CCK-8 assay, the expression level of PKC was detected by Western blot, and the optimal concentration with no obvious toxicity was selected for subsequent mechanism research. Results: Dietary copper dose-dependently regulated rat puberty onset; the 45 mg/kg copper group had the earliest onset, and showed significantly increased levels of reproduction-related hormones (GnRH, FSH, LH, E₂) in serum and HPOA axis. Hypothalamic transcriptomics revealed significantly enriched GnRH signaling pathways and GABAergic synaptic pathways. Mechanistically, this copper dose upregulated hypothalamic KISS-1, GPR54, and PKC (mRNA/protein), and downregulated GABA/GABA-R. Adding 46.8 μmol/L copper (as Cu²⁺, equivalent to optimal in vivo level) could activate the KISS-1/GPR54-GnRH system in hypothalamic neurons; regulating PKC activity could synchronously affect the expression of KISS-1, GPR54, GnRH, and GABA/GABA-R, with additional copper enhancing this effect in vitro experiments. Conclusions: This study demonstrates for the first time that dietary copper at 45 mg/kg promotes puberty onset in SD rats. The mechanism involves activation of the hypothalamic PKC pathway, which inhibits GABAergic neurotransmission while activating the KISS-1/GPR54-GnRH system, thereby enhancing HPOA axis activity and gonadotropin secretion. Full article

Constructed wetland beds are in widespread use for treating wastewater. Their use is well known, and current research is focused on the use of new substrates and different bed configurations, or on assisting the oxygenation process. The authors conducted an extended experiment using VF CWs with two types of filling: gravel, and a waste material called Certyd. Certyd is produced in the sintering process of coal ash, and is a type of waste from combined heat and power (CHP) plant operation. Both beds worked in parallel in order to compare their effectiveness, taking into account seasonality. The obtained database was used for statistical modeling using the P-k-C* model with correction for a trend change at a specific temperature. The obtained models were characterized by good fits to measured quantities. The study demonstrates that Certyd is a viable alternative to gravel. At all temperatures, a bed filled with Certyd has better treatment efficiency. When the temperature at which the trend changes is high, then no additional temperature dependence is recorded when this temperature is exceeded; otherwise, there is a steeper dependency below this temperature, especially in the case of the gravel-filled bed. This result suggests application of Certyd for beds located in colder climates. Full article

The AGC kinases constitute a large and ancient gene superfamily with origins that coincided with the appearance of multicellularity. Three AGC kinase families—protein kinase A (PKA), protein kinase G (PKG), and protein kinase C (PKC)—mediate the actions of neuropeptide hormones, biogenic amines, and other ligands on various physiological processes in metazoans. Metazoans express two PKG types. Jawed vertebrates express three PKA catalytic (C) subunits, four regulatory (R) subunits, and twelve PKCs, organized into conventional, novel delta-like, novel epsilon-like, atypical, and protein kinase N (PKN) subfamilies. By contrast, invertebrate PKA and PKC sequences are not well characterized. Consequently, limited database resources can result in misidentification or mischaracterization of proteins and can lead to misinterpretation of experimental data. A broad phylogenetic and sequence analysis of CrusTome transcriptome and GenBank databases was used to characterize 640 PKA-C sequences, 1122 PKA-R sequences, and 1844 PKC sequences distributed among the Annelida, Arthropoda, Chordata, Cnidaria, Nematoda, Mollusca, Echinodermata, Porifera, Platyhelminthes, and Tardigrada. Phylogenetic analysis and multiple sequence alignments revealed conservation of certain PKA-C, PKA-R and PKC isoforms across metazoans, as well as diversification of additional taxon-specific isoforms. Decapods expressed four PKA-C isoforms, designated PKA-C₁, -C_D1, -C_GLY1, and -C_GLY2; five PKA-R isoforms, designated PKA-RI₁, -RI_D1, -RII_GLY, and -RII_D1; and five PKC isoforms, designated PKN_D1-3, conventional cPKC_D1, novel nPKC_D1δ and nPKC_D1ε, and atypical aPKC_D1. PKA-C_GLY1, -C_GLY2, and -RII_GLY had glycine-rich N-terminal sequences that were unique to crustaceans. These data suggest lineage-specific diversification that retained the core catalytic function of each kinase, while regions outside of the kinase domain may provide specialized regulatory mechanisms and/or spatiotemporal subcellular localization in invertebrate tissues. Full article

Objective: Medical Visual Question Answering (Med-VQA), a key technology that integrates computer vision and natural language processing to assist in clinical diagnosis, possesses significant potential for enhancing diagnostic efficiency and accuracy. However, its development is constrained by two major bottlenecks: weak few-shot generalization capability stemming from the scarcity of high-quality annotated data and the problem of catastrophic forgetting when continually learning new knowledge. Existing research has largely addressed these two challenges in isolation, lacking a unified framework. Methods: To bridge this gap, this paper proposes a novel Evolvable Clinical-Semantic Alignment (ECSA) framework, designed to synergistically solve these two challenges within a single architecture. ECSA is built upon powerful pre-trained vision (BiomedCLIP) and language (Flan-T5) models, with two innovative modules at its core. First, we design a Clinical-Semantic Disambiguation Module (CSDM), which employs a novel debiased hard negative mining strategy for contrastive learning. This enables the precise discrimination of “hard negatives” that are visually similar but clinically distinct, thereby significantly enhancing the model’s representation ability in few-shot and long-tail scenarios. Second, we introduce a Prompt-based Knowledge Consolidation Module (PKC), which acts as a rehearsal-free non-parametric knowledge store. It consolidates historical knowledge by dynamically accumulating and retrieving task-specific “soft prompts,” thus effectively circumventing catastrophic forgetting without relying on past data. Results: Extensive experimental results on four public benchmark datasets, VQA-RAD, SLAKE, PathVQA, and VQA-Med-2019, demonstrate ECSA’s state-of-the-art or highly competitive performance. Specifically, ECSA achieves excellent overall accuracies of 80.15% on VQA-RAD and 85.10% on SLAKE, while also showing strong generalization with 64.57% on PathVQA and 82.23% on VQA-Med-2019. More critically, in continual learning scenarios, the framework achieves a low forgetting rate of just 13.50%, showcasing its significant advantages in knowledge retention. Conclusions: These findings validate the framework’s substantial potential for building robust and evolvable clinical decision support systems. Full article

17β-estradiol (E2) enhances the cerebellar molecular layer interneurons (MLIs)—Purkinje cells (PCs) synaptic transmission via activation of the Erβ in vivo in mice. Whether E2 regulates cerebellar MLI-PC synaptic plasticity is unknown. To investigate the mechanism of E2, we evaluated the modulation of facial stimulation-evoked MLI-PC long-term plasticity in mice. Cell-attached recordings from PCs of Crus II were performed using an Axopatch-700B patch-clamp amplifier. The MLI-PC synaptic transmission was evoked by facial stimulation. Immunohistochemistry was used to detect the expression of ERβ. Under control conditions, 1 Hz facial stimuli induced long-term depression (LTD) at MLI-PC synapses, characterized by a sustained reduction in P1 amplitude and a simple spike (SS) pause. The facial stimulus-induced MLI-PC LTD was completely prevented by E2, but this effect was reversed by a selective ERα/ERβ antagonist, ICI182780. Blockade of cannabinoid receptor 1 (CB1R) eliminated the MLI-PC LTD under control conditions, but revealed an E2-triggered long-term potentiation (LTP). The E2-triggered MLI-PC LTP persisted in the presence of an ERα antagonist but was absent in the presence of an ERβ antagonist PHTPP. The E2-triggered MLI-PC LTP remained unaffected by protein kinase A inhibition but was abolished by inhibition of protein kinase C (PKC) and intracellular Ca²⁺ depletion. Moreover, ERβ immunoreactivity was abundantly distributed around dendrites and somas of PCs in the Crus II region of the mouse cerebellar cortex. The present results suggest that E2 activates ERβ, thereby triggering facial stimulation-induced MLI-PC LTP via the PKC signaling cascade, which occludes CB1R-dependent MLI-PC LTD in the cerebellar cortex of mice in vivo. Full article