Search Results (479)

The aim of this study was to analyze how recombinant rabbit NGF (Nerve Growth Factor) encapsulated in chitosan (rrβNGFch) affects sperm viability, motility, capacitation, acrosome reaction (AR), kinetic traits, and apoptosis after 30 min and 2 h of storage. Specific intracellular signaling pathways associated with either cell survival, such as protein kinase B (AKT) and extracellular signal-regulated kinases 1/2 (ERK1/2), or programmed cell death, such as c-Jun N-terminal kinase (JNK), were also analyzed. The results confirmed the effect of rrβNGFch on capacitation and AR, whereas a longer storage time (2 h) decreased all qualitative sperm traits. AKT and JNK did not show treatment-dependent activation and lacked a correlation with functional traits, as shown by ERK1/2. These findings suggest that rrβNGFch may promote the functional activation of sperm cells, particularly during early incubation. The increase in capacitation and AR was not linked to significant changes in pathways related to cell survival or death, indicating a specific action of the treatment. In contrast, prolonged storage negatively affected all sperm parameters. ERK1/2 activation correlated with capacitation, AR, and apoptosis, supporting its role as an NGF downstream mediator. Further studies should analyze other molecular mechanisms of sperm and the potential applications of NGF in assisted reproduction. Full article

Breast cancer is the second most common cancer in the United States and consists of 30% of all new female cancer each year. PKC iota (PKC-$\iota$) is a bonafide human oncogene and is overexpressed in many types of cancer, including breast cancer. This study explores the role of PKC-$\iota$ in regulating the transcription factor Jun proto-oncogene (c-Jun), pro-inflammatory cytokine Tumor Necrosis Factor-alpha (TNF-$\alpha$), and the Mitogen-Activated Protein Kinase/Jun N-terminal kinase (MAPK/JNK) pathway, which also exhibits an oncogenic role in breast cancer. ICA-1S, a PKC-$\iota$ specific inhibitor, was used to inhibit PKC-$\iota$ to observe the subsequent effect on the levels of c-Jun, TNF-$\alpha$, and the MAPK/JNK signaling pathway. To obtain the results, cell proliferation assay, Western blotting, co-immunoprecipitation, small interfering RNA (siRNA), immunofluorescence, flow cytometry, cycloheximide (CHX) chase assay, and reverse transcription quantitative PCR (RT-qPCR) techniques were implemented. ICA-1S significantly inhibited cell proliferation and induced apoptosis in both breast cancer cell lines. Treatment with ICA-1S and siRNA also reduced the expression levels of the MAPK/JNK pathway protein, c-Jun, and TNF-$\alpha$ in both cell lines. PKC-$\iota$ was also found to be strongly associated with c-Jun, via which it regulated the MAPK/JNK pathway. Additionally, ICA-1S was found to promote the degradation of c-Jun and decrease the mRNA levels of c-Jun. We concluded that PKC-$\iota$ plays a crucial role in regulating breast cancer, and the inhibition of PKC-$\iota$ by ICA-1S reduces breast cancer cell proliferation and induces apoptosis. Therefore, targeting PKC-$\iota$ as a potential therapeutic target in breast cancer could be a significant approach in breast cancer research. Full article

Non-alcoholic fatty liver disease (NAFLD) is a common metabolic condition characterized by hepatic lipid deposits, insulin resistance, and inflammation which may progress to non-alcoholic steatohepatitis (NASH) and fibrosis. Protein kinases play an important role in NAFLD development by regulating metabolic and inflammatory pathways. Mitogen-activated protein kinases (MAPKs), protein kinase C (PKC), AMP-activated protein kinase (AMPK), phosphoinositide 3-kinase (PI3K)/AKT, and mechanistic target of rapamycin (mTOR) are all involved in NAFLD and NASH progression. Emerging evidence indicates that Farnesoid X Receptor (FXR) agonists have therapeutic potential by modulating bile acid metabolism, lipid balance, and inflammatory responses. This review examines the mechanistic interplay between FXR agonists and important protein kinases in NAFLD and NASH. FXR agonists activate AMPK, which promotes fatty acid oxidation and reduces hepatic steatosis. They also regulate MAPK signaling, which reduces c-Jun NH2-terminal kinase (JNK)- and p38 MAPK-mediated inflammation. Furthermore, FXR agonists activate the PI3K/AKT pathway, enhancing insulin sensitivity and modulating mTOR signaling to reduce hepatic fibrosis. Clinical studies in NAFLD/NASH indicate that FXR agonists confer metabolic and anti-inflammatory benefits, although optimizing efficacy and minimizing adverse effects remain challenging. Future studies should focus on combination therapies targeting FXR alongside specific kinases to improve therapeutic outcomes. This review highlights the potential of FXR agonists to modulate protein kinase signaling, opening new avenues for targeted NAFLD/NASH therapy. Full article

Acute heart failure (AHF) is a clinical syndrome characterized by the sudden onset or rapid worsening of heart failure signs and symptoms, frequently triggered by myocardial ischemia, pressure overload, or cardiotoxic injury. A central component of its pathophysiology is the activation of intracellular signal transduction cascades that translate extracellular stress into cellular responses. Among these, the mitogen-activated protein kinase (MAPK) pathways have received considerable attention due to their roles in mediating inflammation, apoptosis, hypertrophy, and adverse cardiac remodeling. The canonical MAPK cascades—including extracellular signal-regulated kinases (ERK1/2), p38 MAPK, and c-Jun N-terminal kinases (JNK)—are activated by upstream stimuli such as angiotensin II (Ang II), aldosterone, endothelin-1 (ET-1), and sustained catecholamine release. Additionally, emerging evidence highlights the role of receptor-mediated signaling, cellular stress, and myeloid cell-driven coagulation events in linking MAPK activation to fibrotic remodeling following myocardial infarction. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling cascade plays a central role in regulating cardiomyocyte survival, hypertrophy, energy metabolism, and inflammation. Activation of the PI3K/Akt pathway has been shown to confer cardioprotective effects by enhancing anti-apoptotic and pro-survival signaling; however, aberrant or sustained activation may contribute to maladaptive remodeling and progressive cardiac dysfunction. In the context of AHF, understanding the dual role of this pathway is crucial, as it functions both as a marker of compensatory adaptation and as a potential therapeutic target. Recent reviews and preclinical studies have linked PI3K/Akt activation with reduced myocardial apoptosis and attenuation of pro-inflammatory cascades that exacerbate heart failure. Among the multiple signaling pathways involved, glycogen synthase kinase-3β (GSK-3β) has emerged as a key regulator of apoptosis, inflammation, metabolic homeostasis, and cardiac remodeling. Recent studies underscore its dual function as both a negative regulator of pathological hypertrophy and a modulator of cell survival, making it a compelling therapeutic candidate in acute cardiac settings. While earlier investigations focused primarily on chronic heart failure and long-term remodeling, growing evidence now supports a critical role for GSK-3β dysregulation in acute myocardial stress and injury. This comprehensive review discusses recent advances in our understanding of the MAPK signaling pathway, the PI3K/Akt cascade, and GSK-3β activity in AHF, with a particular emphasis on mechanistic insights, preclinical models, and emerging therapeutic targets. Full article

Background/Objectives: Allergens can trigger severe immune responses in hypersensitive individuals, with mast cells releasing inflammatory mediators via IgE-FcɛRI signaling. Spleen tyrosine kinase (Syk) is a key regulator in this pathway, making it a promising therapeutic target. Natural modulators of Syk-mediated mast cell activation remain underexplored. This study investigated the anti-allergic effects of a 70% ethanol extract of Salvia miltiorrhiza (SME) using in vitro and in vivo models. Methods: SME was evaluated using IgE-sensitized RBL-2H3 cells, a passive cutaneous anaphylaxis model, and a DNCB-induced atopic dermatitis-like mouse model. Allergic responses were assessed via degranulation assays, histopathology, serum IgE levels, and the spleen index. Results: SME significantly inhibited mast cell degranulation by 44.4 ± 1.6% in RBL-2H3 cells at 100 µg/mL following 30 min of treatment compared to the untreated control. Western blot analysis demonstrated dose-dependent suppression of protein kinase B (PKB, also known as AKT), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and spleen tyrosine kinase (Syk) phosphorylation, indicating inhibition of key allergic signaling pathways. In an IgE/Ag-induced passive cutaneous anaphylaxis model in ICR mice, SME (100 mg/kg, orally) significantly attenuated vascular permeability, as evidenced by a 20.6 ± 9.7% reduction in Evans blue extravasation relative to the Ag-treated group. In a 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD)-like model, six treatments of SME significantly improved the skin condition, reduced spleen enlargement associated with allergic inflammation, and decreased serum IgE levels by 43.3 ± 11.2% compared to the DNCB group. Conclusions: These findings suggest that SME may help to alleviate allergic responses and AD by modulating key immune signaling pathways. Full article

Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment worldwide. AMD development is associated with inflammation, oxidative stress, and a progressive proteostasis imbalance, in whose regulation, c-Jun N-terminal kinases (JNKs) play a crucial role. JNK inhibition is being discussed as a new way to prevent and treat AMD, but there are no data on JNK signaling in the retina and its changes with age and with AMD development. Here, for the first time, we assessed JNK-signaling activity in the retina and did not detect its age-related changes in healthy Wistar rats. By contrast, manifestation and progression of the AMD-like pathology in OXYS rats occurred simultaneously with JNK pathway activation. We also confirmed that selective JNK3 inhibitor 11H-indeno[1,2-b]quinoxalin-11-one oxime sodium salt (IQ-1S) can suppress neurodegenerative changes in the OXYS rat retina. Its effects were prevention of the destructive changes in retinal synapses and the suppression of the JNK signaling pathway activity during active progression of AMD signs in OXYS rats. Full article

Biological, physiological, and psychological stressors cause a “stress response” in our bodies. Stressors that are sensorily perceived (either acute or chronic) trigger hormonal responses from the sympathetic nervous system—the SAM and HPA axis—that effect intended organs to alert the individual. Other stressors have a direct effect on the target organ(s) of the body—e.g., physical injury and wounds, toxins, ionizing, and UV radiation. Both kinds of stressors change cell equilibrium, often leading to reactive oxygen species (ROS) accumulation and cellular damage. Among the signaling pathways involved in fighting these stressors, the c-Jun-N-terminal kinases (JNK) respond to diverse kinds of stressors. This review focuses on JNK1 and JNK2, both of which are ubiquitously present in all cell types, and attention is paid to gastrointestinal tract epithelial cells and their response—including tight junction disruption and cytoskeletal changes. We discuss the seemingly opposite roles of JNK1 and JNK2 in helping cells choose pro-survival and pro-apoptotic pathways. We examine the common features of the JNK protein structure and the possibilities of discovering JNK-isoform-specific inhibitors since, although JNK1 and JNK2 are involved in multiple diseases, including cancer, obesity, diabetes, musculoskeletal and liver disease, no cell-specific or isoform-specific inhibitors are available. Full article

Disruption of the blood–brain barrier (BBB) accompanies many brain diseases, including stroke, neurodegenerative diseases, and brain tumors, leading to swelling, increased neuroinflammation, and neuronal death. In recent years, it has become clear that the c-Jun N-terminal kinase (JNK) signaling pathway is involved in disruption of the structural integrity of the BBB. Activation of the JNK signaling pathway has a negative effect on the functioning of the cellular elements of the neurovascular unit that form the BBB. The aim of this review is to assess the role of the JNK signaling pathway in the disruption of the structural integrity of the BBB in animal models of stroke (MCAO/R, middle cerebral artery occlusion with reperfusion), Alzheimer’s disease, and brain tumors and to analyze the effects of compounds of various natures that directly or indirectly affect the activity of the JNK signaling pathway. These compounds can reduce damage to the BBB and brain edema, reduce neuroinflammation and oxidative stress, reduce the expression of proapoptotic factors, and increase the expression of tight junction proteins. Certain compounds mitigate BBB dysfunction, being promising candidates for neuroprotective therapies. These agents exert their effects, in part, through inhibition of the c-Jun N-terminal kinase (JNK) signaling pathway, a mechanism linked to reduced neuronal damage and improved BBB integrity. Full article

Human type I interferons are crucial regulators of immune responses, essential for controlling infections and activating immune cells. Among them, Interferon Beta (IFNB1) plays a key role in inflammation, and its dysregulation is linked to various diseases, driving efforts to understand the molecular events governing its expression. Here, we identified Mitogen-Activated Protein Kinase 15 (MAPK15) as a novel regulator of IFNB1. Using luciferase reporter assays, gene expression analysis and Enzyme-Linked Immunosorbent Assay (ELISA), we found that MAPK15 downregulation enhanced IFNB1 and Interferon-Stimulated Genes expression and increased IFNB1 secretion. To unveil the underlying mechanisms, we investigated the transcription factors acting on the IFNB1 promoter, revealing that MAPK15 downregulation induced JUN activation. Importantly, pharmacological inhibition of c-Jun N-terminal Kinases (JNKs) supported a key role for this enzyme in JUN activation and consequent IFNB1 expression. Ultimately, by using the antioxidant N-acetylcysteine ethyl ester (NACET), we demonstrated that oxidative stress, induced by MAPK15 downregulation, was responsible for JUN activation and IFNB1 expression. Overall, our findings unveil a novel mechanism by which MAPK15 modulates IFNB1 expression, positioning this kinase as a pivotal regulator of this gene. This insight opens promising avenues for therapeutic intervention, as targeting MAPK15 activity could offer a strategy to rebalance cytokine expression in chronic inflammatory diseases characterized by immune dysregulation. Full article

Microcephaly with pontine and cerebellar hypoplasia (MICPCH) syndrome is a severe neurodevelopmental disorder caused by a deficiency in the X-linked gene calcium/calmodulin-dependent serine protein kinase (CASK). A better understanding of the role of CASK in the pathophysiology of neurodevelopmental disorders may provide insights into novel therapeutic and diagnostic strategies for MICPCH syndrome and other neurodegenerative diseases. To investigate this, we generated CASK knockout (KO) cerebellar granule (CG) cell culture from CASK floxed (CASK^flox/flox) mice by infecting lentiviruses expressing codon-improved Cre recombinase (iCre). We performed RNA-sequencing (RNA-seq) on these cells and found that CASK-KO CG cells underwent apoptosis by activating intracellular Jun N-terminal kinase (JNK) signaling and upregulating reactive oxygen species (ROS)-related gene expression. We also performed mouse gait analysis and limb clasping behavior experiments on trans-heterozygous CASK-KO and Hprt-eGFP (CASK^+/- Hprt^eGFP/+) mice. The CASK^+/- Hprt^eGFP/+ mice exhibited cerebellar ataxic phenotypes as judged by the scores of these experiments compared to the CASK wild-type control (CASK^+/+ Hprt^eGFP/+) mice. Interestingly, the administration of the JNK inhibitor, JNK-IN-8, in CASK-KO CG cell cultures increased CG cell survival by reducing ROS generation. Moreover, injection of JNK-IN-8 into the cerebellum of CASK^+/- Hprt^eGFP/+ mice suppressed CG cell death and alleviated cerebellar ataxic phenotypes in vivo. In conclusion, JNK-IN-8 suppresses the cell death and activation of the ROS pathway in CASK-KO CG cells in both in vitro and in vivo models, suggesting its potential as a therapeutic strategy for cerebellar neurodegeneration in MICPCH syndrome. Full article

(1) Background: Silicosis, a chronic lung fibrosis disorder triggered by the accumulation of silica dust in the deep lung regions, is characterized by intricate molecular mechanisms. Among these, the NOX2 (NADPH oxidase 2) and JNK (C-Jun N-terminal kinase) signaling pathways play pivotal roles in the progression of pulmonary fibrosis. Despite their significance, the precise mechanisms underlying the crosstalk between these pathways remain largely unexplored. (2) Methods: To unravel these interactions, we examined the interplay between JNK and NOX2 in human epithelial cells subjected to silica dust exposure through in vivo assays, followed by validation using single-cell sequencing. Our findings consistently revealed elevated expression levels of key components from both the JNK signaling pathway and NOX2 in the lungs of silicosis-induced mice and silica-treated human epithelial cells. (3) Results: Notably, the activation of these pathways was linked to increased ROS (reactive oxygen species) production, elevated levels of profibrogenic factors, and diminished cell proliferation in silica-exposed human lung epithelial cells. Further mechanistic analyses demonstrated that JNK signaling amplifies NOX2 expression and ROS production induced by silica exposure, while treatment with the JNK inhibitor SP600125 mitigates these effects. Conversely, overexpression of NOX2 enhanced silica-induced JNK activation and the expression of epithelial–mesenchymal transition (EMT)-related factors, whereas NOX2 knockdown exerted the opposite effect. These results suggest a positive feedback loop between JNK and NOX2 signaling, which may drive EMT in lung epithelial cells following silica exposure. (4) Conclusions: This reciprocal interaction appears to play a critical role in lung epithelial cell damage and the pathogenesis of silicosis, shedding light on the molecular mechanisms underlying profibrogenic disease and offering potential avenues for therapeutic intervention. Full article

The type IV secretion system (T4SS) is an important virulence factor of Brucella. T4SS secretes 16 effector proteins, which affect the intracellular transport of Brucella-containing vacuoles and regulate the host immune response, helping Brucella survive and replicate in host cells. In our previous crotonylation proteomics data of HEK-293T cell proteins triggered by BspF, we found BspF crotonylated on TRIM38, which is an important modulator in the pathways of inflammation, and the crotonylation site is K142. Therefore, it is speculated that BspF may be involved in the regulation of host inflammatory response during Brucella infection. In this study, we found that BspF-mediated TRIM38K142 crotonylation promotes the ubiquitination of tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6), leading to the degradation of TRAF6 and thereby inhibiting the transduction of Nuclear factor-kappaB (NF-κB), p38 Mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinases (JNK) MAPK signaling pathways and the secretion of pro-inflammatory factors IL-6 and IL-8, which finally helps Brucella promote intracellular survival. This study provides a new theoretical basis for the intracellular survival of host innate immunity through the T4SS, provides new insights into the pathogenic mechanism and treatment of Brucella, and provides an important reference for the study of non-histone crotonylation function. Full article

The role of the mitogen-activated protein kinase (MAPK) pathway in choroidal neovascularization (CNV) remains unclear. This study investigates the involvement of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 pathways in CNV development, as well as the therapeutic potential of sprouty 2 (SPRY2), an MAPK inhibitor, in a laser-induced mouse model. The expressions of ERK, JNK, and p38 proteins were analyzed using Western blotting and immunostaining. Immunofluorescence imaging revealed increased p-ERK and p-JNK expression in the retina, retinal pigment epithelium (RPE), and choroid up to day 7. Co-immunostaining showed p-ERK colocalized with CD31, CD11b, F4/80, cytokeratin, and GFAP in the retina, while p-JNK and p-p38 were associated with angiogenesis and inflammation throughout the retina and choroid. Compared to aflibercept, SPRY2 administration significantly inhibited CNV lesions, endothelial proliferation, fibrosis, and apoptosis, while better-preserving RPE integrity. SPRY2-treated mice showed a stronger reduction in CNV-related inflammation, epithelial–mesenchymal transition, and photoreceptor apoptosis. These results highlight the MAPK pathway’s role in CNV pathogenesis, with ERK primarily mediating Müller cell gliosis and JNK, contributing to angiogenesis and inflammation. SPRY2 effectively suppressed CNV lesions, supporting its potential as a therapeutic target for CNV treatment via MAPK pathway modulation. Full article

Background: Pseudomonas aeruginosa, one of the common bacterial pathogens causing nosocomial pneumonia, is characterized as highly pathogenic and multidrug-resistant. Kaempferol (KP), a natural flavonoid, has been shown to exhibit effectiveness in treating infection-induced lung injury. Methods: We applied network pharmacology to explore the underlying mechanisms of KP in treating P. aeruginosa pneumonia and further validated them through a mouse model of acute bacterial lung infection and an in vitro macrophage infection model. Results: The in vivo studies demonstrated that treatment with KP suppressed the production of proinflammatory cytokines, including TNF, IL-1β, IL-6, and MIP-2, and attenuated the neutrophil infiltration and lesions in lungs, leading to an increased survival rate of mice. Further studies revealed that KP treatment enhanced the phosphorylation of GSK3β at Ser9 and diminished the phosphorylation of JNK, c-Jun, and NF-κB p65 in lungs in comparison to the mice without drug treatment. Consistently, the in vitro studies showed that pretreatment with KP reduced the activation of GSK3β, JNK, c-Jun, and NF-κB p65 and decreased the levels of the proinflammatory cytokines in macrophages during P. aeruginosa infection. Conclusions: KP reduced the production of proinflammatory cytokines by inhibiting GSK3β/JNK/c-Jun signaling pathways and NF-κB activation, which effectively mitigated the P. aeruginosa-induced acute lung inflammation and injury, and elevated the survival rates of mice. Full article

In traditional Chinese medicine, the root bark and leaves of Schima argentea are utilized to treat dysentery, parasitic infections, and digestive disorders. In this study, the n-butanol extract of S. argentea (NBA) exhibited potent antioxidant properties, protecting HaCaT cells from UVB-induced damage, and was abundant in phenolic and flavonoid compounds. Using UPLC-QTOF-MS analysis, several antioxidants within NBA were identified. Among these, 3,4-dihydroxybenzoic acid, (+)-catechin, and procyanidin B2 effectively reduced ROS levels after 1 h post-UVB treatment (225 mJ/cm²). Notably, all three compounds significantly decreased the phosphorylation of p38 and JNK in a dose-dependent manner. Additionally, the cell survival rate of these compounds was assessed after 12 h post-UVB treatment (225 mJ/cm²). Both 3,4-dihydroxybenzoic acid and (+)-catechin significantly prevented UVB-induced apoptosis in HaCaT cells, as evidenced by MTT, Hoechst, Calcein/PI staining, and flow cytometry analyses. Proteomic analysis revealed that 3,4-dihydroxybenzoic acid achieved photoprotection by downregulating c-Fos and Jun and modulating cell cycle proteins, while (+)-catechin promoted cell repair through the PI3K-Akt and Wnt signaling pathways. These results demonstrated that both compounds can directly absorb UVB, scavenge ROS, and provide cell photoprotection by modulating multiple signaling pathways. The n-butanol extract of S. argentea holds promising potential for future medical applications. Full article