Unraveling the Dual Anti-inflammatory and Antioxidant Mechanisms of Acteoside: Computational Insights and Experimental Validation.

Acteoside (ACT) is one of the primary bioactive ingredients in Cistanche tubulosa (Schenk). Its remarkable efficacy in treating immune-related and inflammatory disorders has garnered significant interest among scientific circles. However, the anti-inflammatory and antioxidant effects of ACT and its underlying molecular mechanisms require further investigation. In this study, pharmacophore-based reverse docking and molecular dynamics simulations identified potential anti-inflammatory targets in silico. Studies conducted in vitro with lipopolysaccharide (LPS)-induced RAW264.7 cells validated the anti-inflammatory properties of ACT. Methyl thiazolyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays indicated ACT's non-toxic and growth-promoting effects on cells. ACT significantly reduced nitric oxide (NO) and reactive oxygen species (ROS) production and restored levels of antioxidant enzymes. It also decreased pro-inflammatory cytokines. Western blotting assays indicated that ACT inhibited p38, TNF-α, PI3K/AKT, and NF-κB signaling pathways. These findings underscore ACT's ability to mitigate acute inflammation in RAW264.7 cells by modulating key signaling pathways and provide the scientific basis for enhancing the medicinal value of ACT and future drug development.

Mitigative Effect and Mechanism of Caffeic Acid Combined with Umbilical Cord-Mesenchymal Stem Cells on LPS-Induced Mastitis.

Mastitis is an inflammation of the mammary gland tissue that can lead to decreased milk production and altered milk composition, carrying serious implications for the safety of dairy products. Although both caffeic acid (CA) and umbilical cord-mesenchymal stem cells (UC-MSCs) showed potential anti-inflammatory and immunomodulatory properties, little is known about their combined roles in treating mastitis. Here, we report the combined effects and mechanisms of CA and UC-MSCs on lipopolysaccharide (LPS)-induced mastitis. Based on the network pharmacological analysis, the potential relevant genes involved in the alleviating effects of CA on LPS-induced mastitis were inferred. In LPS-treated mammary epithelial cells, CA or/and UC-MSC conditioned medium (UC-MSC-CM) inhibited the phosphorylation of p65, p50, p38, IκB, and MKK3/6 proteins and the expression of downstream inflammatory factors TNF-α, IL-1ß, IL-6, IL-8, and COX-2. Additionally, CA or/and hydrogel-loaded UC-MSCs also suppressed the activation of the above inflammatory pathway, leading to the alleviation of pathological damages in the LPS-induced mouse mastitis model. UC-MSCs exhibited more significant effects than CA, and the combined treatment of both was more effective. Our study sheds light on the synergistic and complementary effects of CA and UC-MSCs in alleviating mastitis, offering clues for understanding the regulation of the p38-MAPK/NF-κB↔TNF-α signal transduction loop in the tumor necrosis factor (TNF) pathway as a potential mechanism. This study provides a theoretical basis for developing a novel antibiotic alternative treatment of mastitis that may contribute to reducing economic losses in animal husbandry and protecting public health safety.

Blockage of p38MAPK in astrocytes alleviates brain damage in a mouse model of embolic stroke through the CX43/AQP4 axis.

BACKGROUND: Cerebral edema, a significant complication arising from acute ischemic stroke (IS), has a critical influence on morbidity and mortality. p38MAPK has been shown to promote neuronal apoptosis and brain damage. However, the role of the p38MAPK inhibitor SKF-86002 in protecting against ischemic injury and cerebral edema remains unclear. METHODS: Infarct area was examined by TTC staining in middle cerebral artery occlusion (MCAO) mice. Neurological score and brain water content were evaluated. TUNEL and NeuN staining were used to assess neuronal apoptosis and the survival of neurons. Blood-brain barrier (BBB) permeability was determined by Evans blue. Double immunofluorescence staining detected the colocalization of AQP4 and CX43 in astrocytes. IHC staining revealed CX43 and AQP4 expression. EDU staining detected the proliferation of Oxygen and glucose deprivation/reoxygenation (OGD/R)-treated astrocytes. Levels of oxidative stress markers were determined using commercial kits. ELISA was used to assess the secretion of pro-inflammatory factors. RT-qPCR measured the expression of CX43, AQP4 and pro-inflammatory factors. Western blot analyzed the levels of p-p38/p38, AQP4 and CX43. Co-immunoprecipitation (Co-IP) determined the interaction between CX43 and AQP4. RESULTS: SKF-86002 attenuated brain damage, edema, and neuronal apoptosis in MCAO mice. Astrocyte proliferation was suppressed, and oxidative stress and inflammation were alleviated by SKF-86002 treatment. SKF-86002 negatively regulated p38 signaling and the expression of AQP4 and CX43. Additionally, the expression of CX43/AQP4 within astrocytes was modulated by SKF-86002. CONCLUSION: In summary, SKF-86002 alleviated IS injury and cerebral edema by inhibiting astrocyte proliferation, oxidative stress and inflammation. This effect was associated with the suppression of CX43/AQP4, suggesting that SKF-86002 shows promise as a novel therapeutic approach for preventing IS.

Analysis of the relationship between resistin with prognosis, cell migration, and p38 and ERK1/2 activation in breast cancer.

Obesity increases the risk and mortality of breast cancer through dysregulated secretion of proinflammatory cytokines and tumor adipokines that induce an inflammatory breast microenvironment. Resistin is an adipokine secreted by adipocytes, immune cells, and predominantly macrophages, which contributes to cancer progression, but its molecular mechanism in cancer is not completely described. In this study, we analyzed the relationship of resistin on breast cancer prognosis and tumor progression and the effect in vitro of resistin on p38 and ERK1/2 activation in breast cancer cell lines. By bioinformatic analysis, we found that resistin is overexpressed in the basal subtype triple-negative breast cancer and is related to poor prognosis. In addition, we demonstrated a positive correlation between RETN and MAPK3 expression in basal triple-negative breast cancer. Importantly, we found amplifications of the RETN gene in at least 20 % of metastatic samples from patients with breast cancer. Most samples with RETN amplifications metastasized to bone and showed high expression of IL-8 (CXCL8) and IL-6 (IL6). Finally, resistin could be considered a prognostic marker for basal triple-negative breast cancer, and we also proposed the possibility that resistin-induced cell migration involves the activation of MAPK in breast cancer cells.

Sex differences in the metabolic activation of and platelet response to vicagrel in mice: Androgen as a key player.

As a biological variable, sex influences the metabolism of and/or response to certain drugs. Vicagrel is being developed as an investigational new drug in China; however, it is unknown whether sex could affect its metabolic activation and platelet responsiveness. This study aimed to determine whether such differences could exist, and to elucidate the mechanisms involved. Orchiectomized (ORX) or ovariectomized (OVX) mouse models were used to investigate the effects of androgen or estrogen on the metabolic activation of and platelet response to vicagrel. Plasma vicagrel active metabolite H4 concentrations, platelet inhibition of vicagrel, and protein levels of intestinal hydrolases Aadac and Ces2 were measured, respectively. Further, p38-MAPK signaling pathway was enriched, whose role was determined using SB202190. Results showed that female mice exhibited significantly elevated systemic exposure of H4 and enhanced platelet responses to vicagrel than males, and protein expression levels of Aadac and Ces2 differed by sex. OVX mice exhibited less changes than sham mice. ORX mice exhibited increases in protein levels of intestinal hydrolases, systemic exposure of H4, and platelet inhibition of vicagrel, but dihydrotestosterone (DHT) reversed these changes in ORX mice and suppressed these changes in OVX mice. Phosphorylated p38 levels were reduced in female or ORX mice but increased in ORX mice by DHT. SB202190 reversed DHT-induced changes observed in ORX mice. We concluded that sex differences exist in metabolic activation of and platelet response to vicagrel in mice through elevation of p38 phosphorylation by androgen, suggesting sex-based vicagrel dosage adjustments for patient care.

Acupuncture improves spatial learning and memory impairment caused by herpes simplex virus type-1 in rats through the p38 MAPK/CREB pathway.

BACKGROUND: Acupuncture can improve herpes simplex encephalitis (HSE), but the underlying mechanism is not clear. Therefore, we evaluated the cognitive function and apoptosis in hippocampus caused by herpes simplex virus type-1 (HSV-1) in rats after acupuncture and described the molecular mechanism. METHODS: Sprague-Dawley rats were induced into HSE models by HSV-1 infection. After 3 days, they received acupuncture at the acupoints of Xuanzhong (GB39), Baihui (GV20), Shenmen (HT7), Shenting (GV24), and Sanyinjiao (SP6), and/or intraperitoneal injection of the p38 MAPK inhibitor SB203580. Morris water maze test was performed on rats. The hippocampus of rats was obtained, and the expression of apoptosis-related genes in the tissues was detected by qRT-PCR. In addition, apoptosis-related proteins and proteins related to the p38 MAPK/CREB pathway in the tissues was detected by western blot. RESULTS: After HSV-1 induction, the rat's escape latency was increased, the time spent on the platform in the target quadrant and the number of platform crossings significantly decreased. In addition, there was an increase in apoptosis in the hippocampus, accompanied by elevated levels of p-p38 and decreased levels of p-CREB. However, these effects could be improved by acupuncture treatment. Interestingly, SB203580 plays a similar role to acupuncture, and acupuncture could further enhance the impacts of SB203580 on cognitive function and apoptosis in hippocampus in HSE rats. CONCLUSION: Acupuncture improves spatial learning and memory impairment caused by HSV-1 in rats. The functional mechanism of acupuncture may be through the p38 MAPK/CREB pathway.

Trehalose Attenuates In Vitro Neurotoxicity of 6-Hydroxydopamine by Reducing Oxidative Stress and Activation of MAPK/AMPK Signaling Pathways.

The effects of trehalose, an autophagy-inducing disaccharide with neuroprotective properties, on the neurotoxicity of parkinsonian mimetics 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpiridinium (MPP+) are poorly understood. In our study, trehalose suppressed 6-OHDA-induced caspase-3/PARP1 cleavage (detected by immunoblotting), apoptotic DNA fragmentation/phosphatidylserine externalization, oxidative stress, mitochondrial depolarization (flow cytometry), and mitochondrial damage (electron microscopy) in SH-SY5Y neuroblastoma cells. The protection was not mediated by autophagy, autophagic receptor p62, or antioxidant enzymes superoxide dismutase and catalase. Trehalose suppressed 6-OHDA-induced activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and AMP-activated protein kinase (AMPK), as revealed by immunoblotting. Pharmacological/genetic inhibition of JNK, p38 MAPK, or AMPK mimicked the trehalose-mediated cytoprotection. Trehalose did not affect the extracellular signal-regulated kinase (ERK) and mechanistic target of rapamycin complex 1 (mTORC1)/4EBP1 pathways, while it reduced the prosurvival mTORC2/AKT signaling. Finally, trehalose enhanced oxidative stress, mitochondrial damage, and apoptosis without decreasing JNK, p38 MAPK, AMPK, or AKT activation in SH-SY5Y cells exposed to MPP+. In conclusion, trehalose protects SH-SY5Y cells from 6-OHDA-induced oxidative stress, mitochondrial damage, and apoptosis through autophagy/p62-independent inhibition of JNK, p38 MAPK, and AMPK. The opposite effects of trehalose on the neurotoxicity of 6-OHDA and MPP+ suggest caution in its potential development as a neuroprotective agent.

Ursodeoxycholic acid alleviates fat embolism syndrome-induced acute lung injury by inhibiting the p38 MAPK/NF-κB signalling pathway through FXR.

Acute lung injury (ALI) caused by fat embolism syndrome (FES) is a disease with high mortality. This study aimed to explore the roles of ursodeoxycholic acid (UDCA) in FES-induced ALI and its underlying mechanisms. An ALI mouse model was established by allografting mouse perinephric fat. For in vitro experiments, human pulmonary microvascular endothelial cells (HPMEC) were treated with FFAs. The effects of UDCA on the expression of farnesoid X receptor (FXR) and the inflammatory response in endothelial cells were investigated. UDCA significantly inhibited the inflammatory response and the expression of proinflammatory markers during FES-induced ALI. UDCA markedly decreased TNF-α and IL-1ß expression in vitro. UDCA administration markedly upregulated FXR expression and significantly reduced the phosphorylation of p38 MAPK and NF-κB p65. Knock down FXR expression decreased the effect of UDCA in vivo. Furthermore, knock down FXR expression and overexpressing FXR increased and decreased the inflammatory response, respectively, in vitro. Moreover, administration of a p38 MAPK activator reversed the anti-inflammatory effect of FXR overexpression. UDCA ameliorated inflammation during FES-induced ALI by suppressing p38 MAPK/NF-κB signalling and activating FXR. These findings provide new evidence for the potential of UDCA for FES-induced ALI treatment.

Neuroprotective Effect of Codonopsis pilosula Polysaccharide on Aß25-35-Induced Damage in PC12 Cells via the p38MAPK Signaling Pathways.

OBJECTIVES: Plant polysaccharides have attracted increasing attention due to their high efficiency and low toxicity. Codonopsis pilosula polysaccharide (CPP) is an essential substance extracted from Codonopsis pilosula, known for its excellent antioxidant and neuroprotective effects. However, it is still unclear how CPP improves nerve protection and what its underlying molecular mechanisms are. This study aimed to investigate the neuroprotective effect of CPP on Aß25-35-induced damage in PC12 cells and its underlying molecular mechanisms. METHODS: The neuroprotective effect of CPP was evaluated using Aß25-35-induced damage in pheochFfromocytoma (PC12) cells as an in vitro cell model. The cells were treated with CPP alone or in combination with SB203580 (an inhibitor of p38MAPK) in Aß25-35 culture. The cell viability was assessed using a 3-(4,5-Dimethylthiazol-2-yl)-2,diphenyltetrazolium (MTT) assay. Furthermore, reactive oxygen species (ROS) were detected using flow cytometry. The production levels of intracellular superoxide dismutase (SOD), dismutase (SOD), glutathione (GSH), catalase (CAT), and malondialdehyFde (MDA) were determined using the colorimetric method. Annexin V-FITC and propidium iodide (PI) staining, as well as 33258 were performed using fluorescence microscopy. Moreover, the effect of adding SB203580 was studied to determine the changes in cell apoptosis induced by CPP treatment and Aß25-35 induction. RESULTS: The CPP markedly inhibited Aß25-35-induced reduction in the viability and apoptosis of PC12 cells. CPP also reduced the Aß25-35-induced increase in the expression of the apoptosis factors and the levels of free radicals (ROS and MDA) and reversed the Aß25-35-induced suppression of antioxidant activity. Additionally, inhibition of p38MAPK via the addition of their antagonists reversed the observed anti-apoptosis effects of CPP. CONCLUSIONS: CPP can efficiently provide neuroprotection against Aß25-35-induced damage in PC12 cells brought about via oxidation and apoptosis reactions, and the underlying mechanisms involve the p38MAPK pathways. Therefore, CPP could potentially be useful as a neuroprotective agent in natural medicine, pharmacy, and the food industry.

A first-in-kind MAPK13 inhibitor that can correct stem cell reprogramming and post-injury disease.

The stress kinase MAPK13 (aka p38δ-MAPK) is an attractive entry point for therapeutic intervention because it regulates the structural remodeling that can develop after epithelial barrier injury in the lung and likely other tissue sites. However, a selective, safe, and effective MAPK13 inhibitor is not yet available for experimental or clinical application. Here we identify a first-in-kind MAPK13 inhibitor using structure-based drug design combined with a screening funnel for cell safety and molecular specificity. This inhibitor (designated NuP-4) down-regulates basal-epithelial stem cell reprogramming, structural remodeling, and pathophysiology equivalently to Mapk13 gene-knockout in mouse and mouse organoid models of post-viral lung disease. This therapeutic benefit persists after stopping treatment as a sign of disease modification and attenuates key aspects of inflammation and remodeling as an indication of disease reversal. Similarly, NuP-4 treatment can directly control cytokine-stimulated growth, immune activation, and mucinous differentiation in human basal-cell organoids. The data thereby provide a new tool and potential fix for long-term stem cell reprogramming after viral injury and related conditions that require MAPK13 induction-activation.

Aspartyl proteases target host actin nucleator complex protein to limit epithelial innate immunity.

Epithelial-immune cell communication is pivotal to control microbial infections. We show that glycosylphosphatidylinositol-linked aspartyl proteases (Yapsins) of the human opportunistic pathogenic yeast Candida glabrata (Cg) thwart epithelial cell (EC)-neutrophil signalling by targeting the EC protein, Arpc1B (actin nucleator Arp2/3 complex subunit), which leads to actin disassembly and impeded IL-8 secretion by ECs. Further, the diminished IL-8 secretion inhibits neutrophil migration, and protects Cg from the neutrophil-mediated killing. CgYapsin-dependent Arpc1B degradation requires Arginine-142 in Arpc1B, and leads to reduced Arpc1B-p38 MAPK interaction and downregulated p38 signalling. Consistently, Arpc1B or p38 deletion promotes survival of the Cg aspartyl protease-deficient mutant in ECs. Importantly, kidneys of the protease-deficient mutant-infected mice display elevated immune cell infiltration and cytokine secretion, implicating CgYapsins in immune response suppression in vivo. Besides delineating Cg-EC interplay, our results uncover a novel target, Arpc1B, that pathogens attack to constrain the host signalling networks, and link Arpc1B mechanistically with p38 activation.

Salvia Miltiorrhiza Injection Inhibited the Proliferation of AML Cells by Inducing Apoptosis through the p38MAPK Pathway.

The purpose of this study was to explore the antitumor effect and mechanism of Salvia miltiorrhiza injection (SMI) on acute myeloid leukemia (AML) cells in vitro and in vivo. Bioinformatics was used to detect c-Myc mRNA expression in AML patients in the Oncomine database. qRT‒PCR and western blotting were used to detect the mRNA and protein expression of c-Myc and HOXA5 in clinical samples. Different concentrations (6.25, 12.5, 25, 50 and 100 µg/mL) of SMI were added to KG1a and HL60 cells for 24, 48 and 72 h to determine the IC50 value of SMI. A CCK-8 assay was used to detect the effects of different concentrations of SMI and different treatment times on the proliferation of KG1a and HL60 cells. The indicated concentrations of SMI and SB203580 were used to treat KG1a and HL60 cells. The cell cycle distribution was determined by flow cytometry. The percentage of apoptotic cells was detected by Hoechst 33258 staining and flow cytometry. qRT‒PCR was performed to detect the mRNA expression of p38, c-Myc and HOXA5 in KG1a and HL60 cells. Western blotting was used to detect the protein expression of p38, p-p38, c-Myc, HOXA5, cCaspase 3 and cPARP in KG1a and HL60 cells. AutoDock software was used to analyze the molecular docking of the three main active components of SMI with c-Myc. AutoDock analysis revealed that the binding effect of molecular leisure was evaluated by binding energy, and a binding energy <-5 kcal/mol was considered good. SMI decreased the mRNA and protein expression of c-Myc and HOXA5. SMI significantly inhibited the proliferative activity of KG1a and HL60 cells and induced their apoptosis. However, SMI had no significant effect on the cell cycle distribution of KG1a and HL60 cells. With increasing SMI concentrations, the p-p38/p38 ratio increased, while the protein expression of c-Myc and HOXA5 decreased, and the protein expression of cCaspase and cPARP increased. However, SB203580 intervention in addition to SMI reversed these changes. Tanshinone IIA, cryptanshinone and salvianolic acid B can bind to multiple sites of c-Myc. In summary, SMI could be used for the treatment of acute leukemia, and its mechanism may be related to activation of the p38MAPK signaling pathway.

EtROP38 suppresses apoptosis of host cells infected with Eimeria tenella by inhibition of the p38MAPK pathway.

Coccidiosis is an important parasitic disease that has serious adverse effects on the global poultry industry. The mechanism by which the pathogenic factors of Eimeria tenella damage host cells is unknown. Some kinases from the rhoptry compartment can regulate apoptosis of host cells. This study focused on revealing the role and critical nodes of E. tenella rhoptry protein (EtROP) 38 in controlling the apoptosis of host cells via the P38 mitogen-activated protein kinase (MAPK) signaling pathway. The cells were treated with EtROP38 protein, siRNA p38MAPK, or both. The rate of infection, apoptosis, and the dynamic changes in the expression and activation of key factor genes of the P38MAPK signaling pathway in host cells infected with E. tenella were measured. The results showed that the addition of EtROP38 and/or knockdown of the host cells p38 gene reduced the apoptosis rate of cecal epithelial cells (CECS), decreased the mRNA expressions of p38, p53, c-myc, c-fos, and c-jun and increased the expression of p65, decreased the protein expressions of c-myc, c-fos, and c-jun, decreased the p38 protein phosphorylation level, and increased the p65 protein phosphorylation level in CECS. When E. tenella was inoculated for 4-96 h, the addition of Et ROP38 and/or host cell p38 knockdown both increased the infection rate of host cells, and this effect was more pronounced with the addition of EtROP38 with the host cell p38 knockdown. These observations indicate that E. tenella can inhibits the activation of the p38MAPK signaling pathway in host cells via EtROP38, which suppresses apoptosis in host cells.

12-HETE/GPR31 induces endothelial dysfunction in diabetic retinopathy.

12-hydroxyeicosatetraenoic acid (12-HETE), a major metabolite of arachidonic acid, is converted by 12/15-lipoxygenase and implicated in diabetic retinopathy (DR). Our previous study demonstrated a positive correlation between 12-HETE and the prevalence of DR. However, reasons for the increased production of 12-HETE are unclear, and the underlying mechanisms through which 12-HETE promotes DR are unknown. This study aimed to elucidate the correlation between 12-HETE and DR onset, investigate potential mechanisms through which 12-HETE promotes DR, and seek explanations for the increased production of 12-HETE in diabetes. We conducted a prospective cohort study, which revealed that higher serum 12-HETE levels could induce DR. Additionally, G protein-coupled receptor 31 (GPR31), a high-affinity receptor for 12-HETE, was expressed in human retinal microvascular endothelial cells (HRMECs). 12-HETE/GPR31-mediated HRMEC inflammation occurred via the p38 MAPK pathway. 12-HETE levels were significantly higher in the retina of mice with high-fat diet (HFD)- and streptozotocin (STZ)-induced diabetes than in those with only STZ-induced diabetes and healthy controls. They were positively correlated with the levels of inflammatory cytokines in the retina, indicating that HFD could induce increased 12-HETE synthesis in patients with diabetes in addition to hyperglycemia. Conclusively, 12-HETE is a potential risk factor for DR. The 12-HETE/GPR31 axis plays a crucial role in HRMEC dysfunction and could be a novel target for DR prevention and control. Nevertheless, further research is warranted to provide comprehensive insights into the complex underlying mechanisms of 12-HETE in DR.

Oroxylin A alleviates myocardial ischemia-reperfusion injury by quelling ferroptosis via activating the DUSP10/MAPK-Nrf2 pathway.

Reperfusion therapy is the primary treatment strategy for acute myocardial infarction (AMI). Paradoxically, it can lead to myocardial damage, namely myocardial ischemia/reperfusion injury (MIRI). This study explored whether oroxylin A (OA) protects the myocardium after MIRI by inhibiting ferroptosis and the underlying mechanism. In vivo, we established an MIRI model to investigate the protective effect of OA. In vitro, H9C2 cells were used to explore the regulation of ferroptosis by OA through immunofluorescence staining, western blotting, assay kits, etc. Additionally, RNA sequencing analysis (RNA-seq) and network pharmacology analyses were conducted to elucidate the molecular mechanisms. Our results showed that MIRI caused cardiac structural and functional damage in rats. MIRI promoted ferroptosis, which was consistently observed in vitro. However, pretreatment with OA reversed these effects. The mitogen-activated protein kinases (MAPK) signaling pathway participated in the MIRI process, with dual-specificity phosphatase 10 (DUSP10) found to regulate it. Further confirmation was provided by knocking down DUSP10 using small interfering RNA (siRNA), demonstrating the activation of the DUSP10/MAPK-Nrf2 pathway by OA to protect H9C2 cells from ferroptosis. Our research has demonstrated the mitigating effect of OA on MIRI and the improvement of myocardial function for the first time. The inhibition of ferroptosis has been identified as one of the mechanisms through which OA exerts its myocardial protective effects. Moreover, we have first unveiled that DUSP10 serves as an upstream target involved in mediating ferroptosis, and the regulation of the DUSP10/MAPK-Nrf2 pathway by OA is crucial in inhibiting ferroptosis to protect the myocardium.

NEMO-Binding Domain/IKKγ Inhibitory Peptide Alleviates Neuronal Pyroptosis in Spinal Cord Injury by Inhibiting ASMase-Induced Lysosome Membrane Permeabilization.

A short peptide termed NEMO-binding domain (NBD) peptide has an inhibitory effect on nuclear factor kappa-B (NF-κB). Despite its efficacy in inhibiting inflammatory responses, the precise neuroprotective mechanisms of NBD peptide in spinal cord injury (SCI) remain unclear. This study aims to determine whether the pyroptosis-related aspects involved in the neuroprotective effects of NBD peptide post-SCI.Using RNA sequencing, the molecular mechanisms of NBD peptide in SCI are explored. The evaluation of functional recovery is performed using the Basso mouse scale, Nissl staining, footprint analysis, Masson's trichrome staining, and HE staining. Western blotting, enzyme-linked immunosorbent assays, and immunofluorescence assays are used to examine pyroptosis, autophagy, lysosomal membrane permeabilization (LMP), acid sphingomyelinase (ASMase), and the NF-κB/p38-MAPK related signaling pathway.NBD peptide mitigated glial scar formation, reduced motor neuron death, and enhanced functional recovery in SCI mice. Additionally, NBD peptide inhibits pyroptosis, ameliorate LMP-induced autophagy flux disorder in neuron post-SCI. Mechanistically, NBD peptide alleviates LMP and subsequently enhances autophagy by inhibiting ASMase through the NF-κB/p38-MAPK/Elk-1/Egr-1 signaling cascade, thereby mitigating neuronal death. NBD peptide contributes to functional restoration by suppressing ASMase-mediated LMP and autophagy depression, and inhibiting pyroptosis in neuron following SCI, which may have potential clinical application value.

Exploring the Therapeutic Potential of BBB-Penetrating Phytochemicals With p38 MAPK Modulatory Activity in Addressing Oxidative Stress-Induced Neurodegenerative Disorders, With a Focus on Alzheimer's Disease.

Oxidative stress plays an important role in the occurrence of neurodegenerative diseases. Previous studies indicate a strong connection between oxidative stress, inappropriate activation of the p38 MAPK signaling pathway, and the pathogenesis of neurodegenerative diseases. Although antioxidant therapy is a valid strategy to alleviate these problems, the most important limitation of this approach is the ineffectiveness of drug administration due to the limited permeability of the BBB. Therefore, BBB-penetrating p38 MAPK modulators with proper antioxidant capacity could be useful in preventing/reducing the complications of neurodegenerative disorders. The current manuscript aims to review the therapeutic capabilities of some recently reviewed naturally occurring p38 MAPK inhibitors in the management of neurodegenerative problems such as Alzheimer's disease. In data collection, we tried to use more recent studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so on, but no specific time frame was considered due to the nature of the study. Our evaluations indicate that natural compounds tanshinones, protoberberines, pinocembrin, osthole, rhynchophylline, oxymatrine, schisandrin, piperine, paeonol, ferulic acid, 6-gingerol, obovatol, and trolox have significant potential for use as supplements/adjuvants in the reduction of neurodegenerative-related problems. Our findings emphasize the usefulness of BBB-penetrating phytochemicals with p38 MAPK modulatory activity as potential therapeutic options against neurodegenerative disorders. Of course, the proper use of these compounds depends on considering their toxicity/safety profile and pharmacokinetic characteristics as well as the clinical conditions of users.

A natural acylphloroglucinol exerts anti-erythroleukemia effects via targeting STAT3 and p38-MAPK, and inhibiting PI3K/AKT/mTOR signaling pathway.

Erythroleukemia, a subtype of acute myeloid leukemia (AML), is a life-threatening malignancy that affects the blood and bone marrow. Despite the availability of clinical treatments, the complex pathogenesis of the disease and the severe side effects of chemotherapy continue to impede therapeutic progress in leukemia. In this study, we investigated the antitumor activity of L76, an acylphloroglucinol compound derived from Callistemon salignus DC., against erythroleukemia, along with its underlying mechanisms. MTT assays were performed to evaluate the inhibitory effects of L76 on cancer cell viability, while flow cytometry was used to analyze apoptosis and cell cycle arrest in HEL cells. The molecular mechanisms of L76 were further explored using Western blotting, microscopic analysis, and cellular thermal shift assays (CETSA). Our in vitro experiments demonstrated that L76 inhibits proliferation, induces G1/S cell cycle arrest, and promotes apoptosis in human leukemia cells. Mechanistically, L76 exerts its effects by targeting STAT3 and p38-MAPK, and by inhibiting the PI3K/AKT/mTOR signaling pathway. In conclusion, this study highlights the potential of L76 as an anti-erythroleukemia agent, demonstrating its ability to target STAT3 and p38-MAPK, and to inhibit the PI3K/AKT/mTOR signaling pathway. These findings suggest that L76 could be a promising candidate for the treatment of erythroleukemia.

Deletion of p38 MAPK in macrophages ameliorates peritoneal fibrosis and inflammation in peritoneal dialysis.

One of the most common causes of peritoneal dialysis withdrawal is ultrafiltration failure which is characterized by peritoneal membrane thickening and fibrosis. Although previous studies have demonstrated the inhibitory effect of p38 MAPK inhibitors on peritoneal fibrosis in mice, it was unclear which specific cells contribute to peritoneal fibrosis. To investigate the role of p38 MAPK in peritoneal fibrosis more precisely, we examined the expression of p38 MAPK in human peritoneum and generated systemic inducible p38 MAPK knockout mice and macrophage-specific p38 MAPK knockout mice. Furthermore, the response to lipopolysaccharide (LPS) was assessed in p38 MAPK-knocked down RAW 264.7 cells to further explore the role of p38 MAPK in macrophages. We found that phosphorylated p38 MAPK levels were increased in the thickened peritoneum of both human and mice. Both chlorhexidine gluconate (CG)-treated systemic inducible and macrophage-specific p38 MAPK knockout mice ameliorated peritoneal thickening, mRNA expression related to inflammation and fibrosis, and the number of αSMA- and MAC-2-positive cells in the peritoneum compared to CG control mice. Reduction of p38 MAPK in RAW 264.7 cells suppressed inflammatory mRNA expression induced by LPS. These findings suggest that p38 MAPK in macrophages plays a critical role in peritoneal inflammation and thickening.

Quercetin Mitigates Lysophosphatidylcholine (LPC)-Induced Neutrophil Extracellular Traps (NETs) Formation through Inhibiting the P2X7R/P38MAPK/NOX2 Pathway.

Neutrophil extracellular traps (NETs) are three-dimensional reticular structures that release chromatin and cellular contents extracellularly upon neutrophil activation. As a novel effector mechanism of neutrophils, NETs possess the capacity to amplify localized inflammation and have been demonstrated to contribute to the exacerbation of various inflammatory diseases, including cardiovascular diseases and tumors. It is suggested that lysophosphatidylcholine (LPC), as the primary active component of oxidized low-density lipoprotein, represents a significant risk factor for various inflammatory diseases, such as cardiovascular diseases and neurodegenerative diseases. However, the specific mechanism of NETs formation induced by LPC remains unclear. Quercetin has garnered considerable attention due to its anti-inflammatory properties, serving as a prevalent flavonoid in daily diet. However, little is currently known about the underlying mechanisms by which quercetin inhibits NETs formation and alleviates associated diseases. In our study, we utilized LPC-treated primary rat neutrophils to establish an in vitro model of NETs formation, which was subsequently subjected to treatment with a combination of quercetin or relevant inhibitors/activators. Compared to the control group, the markers of NETs and the expression of P2X7R/P38MAPK/NOX2 pathway-associated proteins were significantly increased in cells treated with LPC alone. Quercetin intervention decreased the LPC-induced upregulation of the P2X7R/P38MAPK/NOX2 pathway and effectively reduced the expression of NETs markers. The results obtained using a P2X7R antagonist/activator and P38MAPK inhibitor/activator support these findings. In summary, quercetin reversed the upregulation of the LPC-induced P2X7R/P38MAPK/NOX2 pathway, further mitigating NETs formation. Our study investigated the potential mechanism of LPC-induced NETs formation, elucidated the inhibitory effect of quercetin on NETs formation, and offered new insights into the anti-inflammatory properties of quercetin.