MAPK-Activated Protein Kinases: Servant or Partner?

Interdisciplinary integration strategy reveals the anti-inflammatory efficacy and potential mechanism of Jianpi Qingre Tongluo prescription in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic synovitis and associated with high rates of disability and systemic damage. Jianpi Qingre Tongluo prescription (Huangqin Qingre Chubi Capsule, HQC), an herbal formula with abundant clinical applications, has played a definite role in both clinical and experimental studies of RA. However, the specific mechanisms by which HQC relieves inflammation in RA have not been fully elucidated.

OBJECTIVE

This study aimed to elucidate the anti-inflammatory efficacy and potential molecular mechanisms of HQC in RA and provide new targets and strategies for its clinical treatment.

METHODS

An adjuvant-induced arthritis with damp-heat pattern rat model was established to observe the in vivo effects of HQC. Hematoxylin-eosin and toluidine blue staining, and enzyme-linked immunosorbent assay were used to assess potential efficacy. Bioinformatics methods and molecular docking were used to predict potential targets and intervention pathways in which HQC might act on RA. Clinical samples, overexpressed / silenced genes, and pathway agonists were selected to investigate the clinical relevance and regulatory relationships of the pathways. The regulatory mechanism of HQC was confirmed in an in vitro co-culture of neutrophils and fibroblast-like synoviocytes (FLSs) and an in vivo model.

RESULTS

HQC dose-dependently reversed synovial pathological injury and systemic inflammatory responses in rats in vivo. Integrated bioinformatics and molecular docking identified the p38 mitogen-activated protein kinase (MAPK) signaling pathway and neutrophil extracellular trap (NET) formation as the key mechanisms by which HQC exerts anti-inflammatory effects on RA. Subsequently, a high correlation between circ0005732, p38 MAPK, and clinical features of RA was confirmed in clinical samples. In vitro experiments demonstrated that HQC alleviated the proliferation and inflammatory response of FLSs by regulating circ0005732 expression to inhibit NET formation driven by the p38 MAPK signaling pathway. Finally, RT-qPCR and western blotting confirmed that HQC modulated circ0005732, p38 MAPK pathway, and NET formation to alleviate RA in vivo.

CONCLUSION

HQC exerts therapeutic effects against RA by modulating circ0005732 to inhibit p38 MAPK signaling pathway-mediated NET generation and inflammation progression.

Targeting the TLK1-MK5 Axis Suppresses Prostate Cancer Metastasis

Background: The spread of metastatic prostate cancer (PCa) is responsible for the majority of PCa-related deaths, yet the precise mechanisms driving this process remain unclear. We have identified a novel interaction between two distinct promotility factors, tousled-like kinase 1 (TLK1) and MAPK-activated protein kinase 5 (MK5), which triggers a signaling cascade that promotes metastasis. In PCa, the TLK1-MK5 pathway may play a critical role, as androgen deprivation therapy (ADT) has been linked to increased expression of both TLK1 and MK5 in metastatic patients linked with poor survival. Objectives: In this study, we directly examined the effects of disrupting the TLK1>MK5 axis on the motility, invasiveness, and metastatic potential of PCa cells. Methods: To establish this, we used both pharmacologic and systemic approaches with genetically engineered mouse models and the use of IVIS. Results: The results of targeting the TLK1>MK5 axis support the notion that this axis is essential for the spread of metastatic cells and the development of age-related metastases.

Targeted inhibition of NPR3/MAPK pathway enhances dental pulp stem cell multipotency: Mechanistic validation based on ligustrazine (TMP)

BACKGROUND

The multipotency of dental pulp stem cells (DPSCs) plays a crucial role in dental tissue regeneration, yet its regulatory mechanisms remain incompletely understood. This study aimed to investigate the role of natriuretic peptide receptor 3 (NPR3) in regulating DPSCs functions and validate the mechanism of its targeted inhibitor ligustrazine (TMP).

METHODS

NPR3 expression in DPSCs was examined by Western blot and immunohistochemistry. The effects of NPR3 on DPSCs colony formation, migration, and differentiation were investigated through overexpression and knockdown strategies. The relationship between NPR3 and ERK1/2 pathway was explored using molecular biological approaches. High-throughput drug screening was employed to identify TMP as an NPR3 inhibitor, followed by mechanism validation.

RESULTS

NPR3 was highly expressed in mature odontogenic DPCs, with its expression levels closely correlated with DPSCs functions. Functional assays demonstrated that NPR3 inhibited DPSCs colony formation, migration, and differentiation capabilities, while NPR3 knockdown significantly enhanced these functions. Mechanistic studies revealed that NPR3 influenced DPSCs functions through positive regulation of ERK1/2 phosphorylation. Through high-throughput screening, we identified TMP as a specific NPR3 inhibitor that promoted DPSCs functions. Rescue experiments further confirmed that NPR3 overexpression or ERK1/2 inhibitor SCH772984 attenuated TMP-induced enhancement, validating TMP's action through the NPR3/MAPK pathway.

CONCLUSION

This study reveals the crucial role of the NPR3/MAPK pathway in regulating DPSCs multipotency and demonstrates that TMP enhances DPSCs functions through targeted inhibition of this pathway, providing new therapeutic strategies and drug targets for dental tissue regeneration.

A close-up of regulatory networks and signaling pathways of MKK5 in biotic and abiotic stresses

Mitogen-activated protein Kinase Kinase 5 (MKK5) is a central hub in the complex phosphorylation chain reaction of the Mitogen-activated protein kinases (MAPK) cascade, regulating plant responses to biotic and abiotic stresses. This review manuscript aims to provide a comprehensive analysis of the regulatory mechanism of the MKK5 involved in stress adaptation. This review will delve into the intricate post-transcriptional and post-translational modifications of the MKK5, discussing how they affect its expression, activity, and subcellular localization in response to stress signals. We also discuss the integration of the MKK5 into complex signaling pathways, orchestrating plant immunity against pathogens and its modulating role in regulating abiotic stresses, such as: drought, cold, heat, and salinity, through the phytohormonal signaling pathways. Furthermore, we highlight potential applications of the MKK5 for engineering stress-resilient crops and provide future perspectives that may pave the way for future studies. This review manuscript aims to provide valuable insights into the mechanisms underlying MKK5 regulation, bridge the gap from numerous previous findings, and offer a firm base in the knowledge of MKK5, its regulating roles, and its involvement in environmental stress regulation.

Targeting p38 MAPK signaling pathway and neutrophil extracellular traps: An important anti-inflammatory mechanism of Huangqin Qingre Chubi Capsule in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common chronic autoimmune disease. Neutrophils release and their extracellular traps (NETs) tend to result in synovial inflammation and cartilage damage. Huangqin Qingre Chubi Capsule (HQC) is an important herbal formulation for RA treatment and has been used for many years. This study applied an interdisciplinary and integrated strategy combining clinical data, integrative bioinformatics, molecular modeling, and both in vitro and in vivo experiments to elucidate the efficacy and potential anti-inflammatory mechanisms of HQC for RA. Retrospective clinical data mining demonstrated that patients with RA treated with HQC exhibited recovery of immuno-inflammatory markers and self-perception. By applying network pharmacological analysis, molecular docking, molecular dynamics simulation, and cellular thermal shift assays, we determined that HQC can directly bind to MAPK14 and target p38 MAPK signaling pathway and NETs formation. Treatment of an adjuvant-induced arthritis rat model combining damp-heat patterns using HQC demonstrated it's effectiveness in reducing the severity of inflammatory arthritis in a dose-dependent manner and downregulated phosphorylation of p38 MAPK and NETs release. In vitro co-culture system mimicking inflammatory microenvironment of RA in vivo revealed that crosstalk between neutrophils (PMNs) and fibroblast-like synoviocytes (FLSs) was manifested by activation of p38 MAPK signaling pathway, release of NETs, and amplification of inflammation, which was blocked by HQC. Mechanistic validation using the p38 MAPK agonist diprovocim demonstrated that HQC inhibited NET formation by modulating the p38 MAPK pathway (mainly by inhibiting its phosphorylation) to exert anti-inflammatory effects. In conclusion, our interdisciplinary and integrated study demonstrated that HQC can target the p38 MAPK signaling pathway to inhibit NET formation and inflammatory response, thereby blocking the crosstalk between PMNs and FLSs to ameliorating RA.

Specific Knockdown of the NDUFS4 Gene Reveals Important Roles of Ferroptosis in UVB-induced Photoaging

Ultraviolet (UV) irradiation significantly contributes to photoaging. Ferroptosis, an iron-dependent cell death mode recently identified, plays a key role in UVB-induced skin photoaging. This study examines the functions and regulatory mechanisms of ferroptosis in this regard. Characterized by increased intracellular iron and reactive oxygen species (ROS), ferroptosis is associated with mitochondrial function and structure. Through RNA sequencing, we identified NADH: ubiquinone oxidoreductase subunit S4 (NDUFS4), a gene implicated in UVB-mediated photoaging, and explored its role in ferroptosis by NDUFS4 knockdown. In vitro, inhibiting NDUFS4 reduced ferroptosis, decreased ROS and matrix metallopeptidase 1 levels, and increased collagen type I alpha 1 chain, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1, and solute carrier family 7 member 11 levels, suggesting a reinforced ferroptosis protective mechanism. Additionally, NDUFS4 regulates ferroptosis via the mitogen-activated protein kinase (MAPK) pathway, with its knockdown reducing p38 and ERK phosphorylation and elevating GPX4 levels, enhancing ferroptosis resistance. Animal experiments supported these findings, demonstrating that Ferrostatin-1, a ferroptosis inhibitor, significantly mitigated UVB-induced skin photoaging and related protein expression. This study uncovers NDUFS4's novel role in regulating ferroptosis and provides new insights into ferroptosis-mediated UVB-induced skin photoaging.

Influencing inter-cellular junctions with nanomaterials

Cell-cell junctions are essential for maintaining tissue integrity and regulating a wide range of physiological processes. While the disruption of intercellular junctions may lead to pathological conditions, it also presents an opportunity for therapeutic interventions. Nanomaterials have emerged as promising tools for modulating cell-cell junctions, offering new avenues for innovative treatments. In this review, we provide a comprehensive overview of the various nanomaterials interaction with cell-cell junctions. We discussed their underlying mechanisms, heterogenous effects on cellular behavior, and the therapeutic strategies of applying nanomaterial-induced intercellular junction disruption. Additionally, we address the challenges and opportunities involved in translating these strategies into clinical practice and discuss future directions for this rapidly advancing field.

Astragaloside IV ameliorates atherosclerosis by targeting TAK1 to suppress endothelial cell proinflammatory activation

BACKGROUND

Atherosclerosis is a chronic inflammatory disease mainly characterized by the activation of endothelial cells and recruitment of macrophages, leading to plaque formation. Astragaloside IV (AS-IV), a natural saponin derived from Astragalus mongholicus Bunge, has been shown to confer protective effects against cardiovascular diseases.

PURPOSE

The purpose of this study is to explore the role of AS-IV on atherosclerosis and the underlying mechanism.

METHODS

Mice with atherosclerosis were administered with AS-IV by oral gavage. Atherosclerotic plaques and blood lipid profiles of these mice were assessed. Endothelial cell activation and macrophage infiltration were examined by immunofluorescent or immunohistochemical staining. The effects of AS-IV on endothelial cell activation, macrophage migration and adhesion were determined by transwell experiments, RT-qPCR, and Western blot.

RESULTS

Mice treated with AS-IV exhibited a dose-dependent reduction in atherosclerotic plaque size, with no concomitant change in blood lipid levels. It significantly suppressed endothelial cell activation and macrophage infiltration in the vasculature. AS-IV inhibited TNF-α-induced endothelial cell activation and macrophage migration and adhesion in vitro. Furthermore, AS-IV reduced the phosphorylation of key kinases in the MAPK pathways and their upstream regulator TAK1 in endothelial cells. The inhibitory effects of AS-IV on MAPK pathways and endothelial cell activation were counteracted by TAK1 deficiency or overexpression of TAK1. Molecular docking analysis suggested AS-IV binds to TAK1 with high affinity.

CONCLUSION

AS-IV exhibits anti-atherosclerotic effects by targeting TAK1 in endothelial cells, thereby inhibiting endothelial cell activation, and the subsequent adhesion and migration of macrophages, providing a prospective therapeutic strategy for the management of atherosclerosis.

MAPK4 inhibits the early aberrant activation of B cells in rheumatoid arthritis by promoting the IRF4-SHIP1 signaling pathway

The involvement of B lymphocytes in the pathogenesis of rheumatoid arthritis (RA) is well-established, with their early and aberrant activation being a crucial factor. However, the mechanisms underlying this abnormal activation in RA remain incompletely understood. In this study, we identified a significant reduction in MAPK4 expression in both RA patients and collagen-induced arthritis (CIA) mouse models, which correlates with disrupted B cell activation. Using MAPK4 knockout (KO) mice, we demonstrated that MAPK4 intrinsically promotes the differentiation of marginal zone (MZ) B cells. Loss of MAPK4 in KO mice enhances proximal BCR signaling and activates the PI3K-AKT-mTOR pathway, leading to heightened B cell proliferation. Notably, B cells from MAPK4 KO mice produce significantly higher levels of IL-6, a key pro-inflammatory cytokine in RA. Furthermore, MAPK4 KO mice exhibit impaired T cell-independent humoral immune responses. Mechanistically, MAPK4 inhibits the activation of the PI3K signaling pathway in B cells by activating the IRF4-SHIP1 pathway. Treatment with the MAPK4 agonist Vacquinol-1 enhances MZ B cell differentiation in WT mice and reduces IL-6 secretion in CIA mouse models. In summary, this study reveals the diverse roles of MAPK4 in regulating of B cell functions, with potential implications for developing therapeutic strategies for RA and related autoimmune diseases.

Molecular Mechanisms of Grain Chalkiness Variation in Rice Panicles

Grain chalkiness adversely affects rice quality, and the positional variation of grain chalkiness within a rice panicle presents a substantial obstacle to quality improvement in China. However, the molecular mechanism underlying this variation is unclear. This study conducted a genetic and physiological analysis of grains situated at distinct positions (upper, middle, and bottom primary branches of the rice panicle, denoted as Y1, Y2, and Y3) within a rice panicle using the Yangdao 6 variety. The results indicated that the percentage of chalky grains (PCG) in Y1 was the highest, i.e., 17.12% and 52.18% higher than that of Y2 and Y3, respectively. Y2 exhibited the highest degree of grain chalkiness (DGC), attributable to its greater area of endosperm chalkiness (AEC) than the others. Y3 demonstrated the lowest PCG and DGC. Additionally, Y1 and Y2 were characterized by lower amylose and protein contents, as well as looser starch granule morphology, in comparison to Y3. Compared with Y3, both the average and maximum filling rates of Y1 and Y2 increased markedly; however, the active filling duration was notably reduced by 7.10 d and 5.56 d, respectively. The analysis of genomic expression levels indicated an enrichment of starch and sucrose metabolism in Y1-vs.-Y2, Y2-vs.-Y3, and Y1-vs.-Y3, with 7 genes (5 up-regulated and 2 down-regulated), 53 genes (12 up-regulated and 41 down-regulated), and 12 genes (2 up-regulated and 10 down-regulated) in the Y1-vs.-Y2, Y2-vs.-Y3, and Y1-vs.-Y3. The majority of these genes were down-regulated, linking metabolic activity to grain filling and contributing to the occurrence of grain chalkiness in rice panicles. In conclusion, the metabolic processes associated with sucrose and starch play a crucial role in regulating grain filling and the formation of chalkiness in rice.

Human REXO4 is Required for Cell Cycle Progression

Human REXO4 is a poorly characterized exonuclease that is overexpressed in human cancers. To better understand the function of REXO4 and its relationship to cellular proliferation, we have undertaken multidisciplinary approaches to characterize its cell cycle phase-dependent subcellular localization and the cis determinants required for this localization, its importance to cell cycle progression and cell viability, its protein-protein association network, and its activity. We show that the localization of REXO4 to the nucleolus in interphase depends on an N-terminal nucleolar localization sequence and that its localization to the perichromosomal layer of mitotic chromosomes is dependent on Ki67. Depletion of REXO4 led to a G1/S cell cycle arrest, and reduced cell viability. REXO4 associated with ribosome components and other proteins involved in rRNA metabolism. We propose a model where REXO4 is important for proper rRNA processing, which is required for ribosome biogenesis, cell cycle progression, and proliferation.

Dual-action kinase inhibitors influence p38α MAP kinase dephosphorylation

Reversible protein phosphorylation directs essential cellular processes including cell division, cell growth, cell death, inflammation, and differentiation. Because protein phosphorylation drives diverse diseases, kinases and phosphatases have been targets for drug discovery, with some achieving remarkable clinical success. Most protein kinases are activated by phosphorylation of their activation loops, which shifts the conformational equilibrium of the kinase toward the active state. To turn off the kinase, protein phosphatases dephosphorylate these sites, but how the conformation of the dynamic activation loop contributes to dephosphorylation was not known. To answer this, we modulated the activation loop conformational equilibrium of human p38α ΜΑP kinase with existing kinase inhibitors that bind and stabilize specific inactive activation loop conformations. From this, we identified three inhibitors that increase the rate of dephosphorylation of the activation loop phospho-threonine by the PPM serine/threonine phosphatase WIP1. Hence, these compounds are "dual-action" inhibitors that simultaneously block the active site and promote p38α dephosphorylation. Our X-ray crystal structures of phosphorylated p38α bound to the dual-action inhibitors reveal a shared flipped conformation of the activation loop with a fully accessible phospho-threonine. In contrast, our X-ray crystal structure of phosphorylated apo human p38α reveals a different activation loop conformation with an inaccessible phospho-threonine, thereby explaining the increased rate of dephosphorylation upon inhibitor binding. These findings reveal a conformational preference of phosphatases for their targets and suggest a unique approach to achieving improved potency and specificity for therapeutic kinase inhibitors.

MAPK signaling pathway in spinal cord injury: Mechanisms and therapeutic potential

Spinal cord injury (SCI) is a severe disabling injury of the central nervous system that can lead to motor, sensory, and autonomic dysfunction below the level of the injury. According to its pathophysiological process, SCI can be divided into primary injury and secondary injury. Currently, multiple therapeutic strategies have been proposed to alleviate secondary injury and overcome the occurrence of neurodegenerative events. Although current treatment modalities have achieved varying degrees of success, they cannot effectively intervene or treat its pathological processes, which may be due to the complex treatment and protection mechanisms involved. Research has confirmed that signaling pathways play a crucial role in the pathological processes of SCI and the mechanisms of neuronal recovery. Mitogen-activated protein kinase (MAPK) signaling pathway plays a crucial role in neuronal differentiation, growth, survival and axon regeneration after central nervous system injury. Meanwhile, the MAPK signaling pathway is an important pathway closely related to the pathological processes of SCI. The MAPK signaling pathway is abnormally activated after SCI, and inhibiting the activity of MAPK pathway can effectively inhibit inflammation, oxidative stress, pain and apoptosis to promote the recovery of nerve function after SCI. Based on the role of the MAPK pathway in SCI, it may be a potential therapeutic target. This article summarizes the role and mechanism of MAPK pathway in SCI, and discusses the shortcomings and shortcomings of MAPK pathway in SCI field, as well as the potential challenges of targeting MAPK pathway in SCI treatment strategies. This article aims to elucidate the mechanism of the MAPK pathway in SCI to emphasize the role of targeting the MAPK pathway in the treatment of SCI, providing a theoretical basis for the MAPK pathway as a potential therapeutic target for SCI treatment.

Disturbed shear stress promotes atherosclerosis through TRIM21-regulated MAPK6 degradation and consequent endothelial inflammation

RATIONALE

Coronary artery plaques often develop in regions subjected to disturbed shear stress (DSS), yet the mechanisms underlying this phenomenon remain poorly understood. Our study aimed to elucidate the unknown role of MAPK6 in shear stress and plaque formation.

METHODS

In vitro and in vivo experiments, RNA-seq, CO-IP and proteomic analysis, combined with single-cell RNA-seq datasets were used to reveal the upstream and downstream mechanisms involved. AAV-MAPK6, ApoE-/-MAPK6flox/floxTEKCre mice and the CXCL12 neutraligand were used to confirm the beneficial effects of MAPK6 against atherosclerosis.

RESULTS

Our study revealed a substantial decrease in MAPK6 protein levels in endothelial cells in response to DSS, both in vivo and in vitro, which was contingent on the binding of the ubiquitin ligase TRIM21 to MAPK6. Endothelium-specific MAPK6 overexpression exerts antiatherosclerotic effects in ApoE-/- mice, elucidating the unexplored role of MAPK6 in atherosclerosis. Comprehensive RNA-seq, integrated single-cell mapping and further experiments unveiled the involvement of MAPK6 in inflammation through the EGR1/CXCL12 axis. ApoE-/-MAPK6flox/floxTEKCre mice finally confirmed that conditional MAPK6 knockout resulted in endothelial inflammation and significant increases in plaque areas. Notably, these effects could be reversed through the neutralization of CXCL12.

CONCLUSIONS

Our study illuminates the advantages of MAPK6 in decelerating plaque progression, highlighting the potential of safeguarding MAPK6 as a novel therapeutic strategy against atherosclerosis.

KEY POINTS

Disturbed flow activates the ubiquitin‒proteasome degradation pathway of MAPK6 in endothelial cells, which is contingent on the binding of the ubiquitin ligase TRIM21 to MAPK6. Endothelial MAPK6 has an advantageous impact on decelerating plaque progression. MAPK6 regulates endothelial inflammation via the EGR1/CXCL12 axis.

The role of MAPK pathway in gastric cancer: unveiling molecular crosstalk and therapeutic prospects

Gastric cancer remains a significant health burden globally, especially prevalent in Asian and European regions. Despite a notable decline in incidence in the United States and Western Europe over recent decades, the disease's persistence underscores the urgency for advanced research in its pathogenesis and treatment strategies. Central to this pursuit is the exploration of the mitogen-activated protein kinase (MAPK) pathway, a pivotal cellular mechanism implicated in the complex processes of gastric cancer development, including cellular proliferation, invasion, migration, and metastasis. The MAPK or extracellular signal-regulated kinase pathway serves as a crucial conduit for transmitting extracellular signals to elicit intracellular responses, with its signaling cascades subject to alterations due to genetic and epigenetic variations across various diseases, prominently cancer. This review delves into the intricate role of the MAPK signaling pathway in the pathogenesis of gastric cancer, drawing upon the most recent and critical studies that shed light on MAPK pathway alterations as a gateway to the disease. It highlights the pathway's involvement in Helicobacter pylori-mediated gastric carcinogenesis and the tumorigenic processes induced by the Epstein-Barr virus, showcasing the substantial influence of miRNAs and lncRNAs in modulating gastric cancer's biological properties through their interaction with the MAPK pathway. Furthermore, the review extends into the therapeutic arena, discussing the promising impacts of herbal medicines, MAPK pathway inhibitors, and immunosuppressants on mitigating gastric cancer's progression. Through an exhaustive examination of the MAPK pathway's multifaceted role in gastric cancer, from molecular crosstalks to therapeutic prospects, this review aspires to contribute to the ongoing efforts in understanding and combating this global health challenge, paving the way for novel therapeutic interventions and improved patient outcomes.

The ribotoxic stress response drives acute inflammation, cell death, and epidermal thickening in UV-irradiated skin in vivo

Solar UVB light causes damage to the outermost layer of skin. This insult induces rapid local responses, such as dermal inflammation, keratinocyte cell death, and epidermal thickening, all of which have traditionally been associated with DNA damage response signaling. Another stress response that is activated by UVB light is the ribotoxic stress response (RSR), which depends on the ribosome-associated mitogen-activated protein 3 kinases (MAP3K) ZAKα and culminates in p38 and JNK activation. Using ZAK knockout mice, we here show that it is the RSR that is responsible for the early manifestation of UVB-induced skin inflammation and keratinocyte death and subsequent proliferation in vivo. We also show that the RSR controls both p38-mediated pyroptotic and JNK-mediated apoptotic programmed cell death of human keratinocytes in vitro. In sum, our work highlights that skin cells rely on a cytoplasmic and ribosomal stress signal rather than a nuclear and DNA-templated signal for rapid inflammatory responses to UV exposure.

The Influence of Extra-Ribosomal Functions of Eukaryotic Ribosomal Proteins on Viral Infection

The eukaryotic ribosome is a large ribonucleoprotein complex consisting of four types of ribosomal RNA (rRNA) and approximately 80 ribosomal proteins (RPs), forming the 40S and 60S subunits. In all living cells, its primary function is to produce proteins by converting messenger RNA (mRNA) into polypeptides. In addition to their canonical role in protein synthesis, RPs are crucial in controlling vital cellular processes such as cell cycle progression, cellular proliferation, differentiation, DNA damage repair, genome structure maintenance, and the cellular stress response. Viruses, as obligate intracellular parasites, depend completely on the machinery of the host cell for their replication and survival. During viral infection, RPs have been demonstrated to perform a variety of extra-ribosomal activities, which are especially important in viral disease processes. These functions cover a wide range of activities, ranging from controlling inflammatory responses and antiviral immunity to promoting viral replication and increasing viral pathogenicity. Deciphering the regulatory mechanisms used by RPs in response to viral infections has greatly expanded our understanding of their functions outside of the ribosome. Furthermore, these findings highlight the promising role of RPs as targets for the advancement of antiviral therapies and the development of novel antiviral approaches. This review comprehensively examines the many functions of RPs outside of the ribosome during viral infections and provides a foundation for future research on the host-virus interaction.

Negative regulation of APC/C activation by MAPK-mediated attenuation of Cdc20Slp1 under stress

Mitotic anaphase onset is a key cellular process tightly regulated by multiple kinases. The involvement of mitogen-activated protein kinases (MAPKs) in this process has been established in Xenopus egg extracts. However, the detailed regulatory cascade remains elusive, and it is also unknown whether the MAPK-dependent mitotic regulation is evolutionarily conserved in the single-cell eukaryotic organisms such as fission yeast (Schizosaccharomyces pombe). Here, we show that two MAPKs in S. pombe indeed act in concert to restrain anaphase-promoting complex/cyclosome (APC/C) activity upon activation of the spindle assembly checkpoint (SAC). One MAPK, Pmk1, binds to and phosphorylates Slp1Cdc20, the co-activator of APC/C. Phosphorylation of Slp1Cdc20 by Pmk1, but not by Cdk1, promotes its subsequent ubiquitylation and degradation. Intriguingly, Pmk1-mediated phosphorylation event is also required to sustain SAC under environmental stress. Thus, our study establishes a new underlying molecular mechanism of negative regulation of APC/C by MAPK upon stress stimuli, and provides a previously unappreciated framework for regulation of anaphase entry in eukaryotic cells.

Nanotechnology-Mediated Immunomodulation Strategy for Inflammation Resolution

Inflammation serves as a common characteristic across a wide range of diseases and plays a vital role in maintaining homeostasis. Inflammation can lead to tissue damage and the onset of inflammatory diseases. Although significant progress is made in anti-inflammation in recent years, the current clinical approaches mainly rely on the systemic administration of corticosteroids and antibiotics, which only provide short-term relief. Recently, immunomodulatory approaches have emerged as promising strategies for facilitating the resolution of inflammation. Especially, the advanced nanosystems with unique biocompatibility and multifunctionality have provided an ideal platform for immunomodulation. In this review, the pathophysiology of inflammation and current therapeutic strategies are summarized. It is mainly focused on the nanomedicines that modulate the inflammatory signaling pathways, inflammatory cells, oxidative stress, and inflammation targeting. Finally, the challenges and opportunities of nanomaterials in addressing inflammation are also discussed. The nanotechnology-mediated immunomodulation will open a new treatment strategy for inflammation therapy.

Natural Compounds for the Treatment of Acute Pancreatitis: Novel Anti-Inflammatory Therapies

Acute pancreatitis remains a serious public health problem, and the burden of acute pancreatitis is increasing. With significant morbidity and serious complications, appropriate and effective therapies are critical. Great progress has been made in understanding the pathophysiology of acute pancreatitis over the past two decades. However, specific drugs targeting key molecules and pathways involved in acute pancreatitis still require further study. Natural compounds extracted from plants have a variety of biological activities and can inhibit inflammation and oxidative stress in acute pancreatitis by blocking several signaling pathways, such as the nuclear factor kappa-B and mitogen-activated protein kinase pathways. In this article, we review the therapeutic effects of various types of phytochemicals on acute pancreatitis and discuss the mechanism of action of these natural compounds in acute pancreatitis, aiming to provide clearer insights into the treatment of acute pancreatitis.

The p38/MAPK pathway as a therapeutic target to prevent therapeutic escape of breast cancer stem cells

Cancer stem cells (CSCs) play an important role in metastasis development, tumor recurrence, and treatment resistance, and are essential for the eradication of cancer. Currently, therapies fail to eradicate CSCs due to their therapeutic stress-induced cellular escape, which leads to enhanced aggressive behaviors compared with CSCs that have never been treated. However, the underlying mechanisms regulating the therapeutic escape remain unknown. To this end, we established a model to isolate the therapeutic escaped CSCs (TSCSCs) from breast CSCs and performed the transcription profile to reveal the mechanism. Mechanistically, we demonstrated that the behavior of therapeutic escape was regulated through the p38/MAPK signaling pathway, resulting in TSCSCs exhibiting enhanced motility and metastasis. Notably, blocking the p38/MAPK signaling pathway effectively reduced motility and metastasis ability both in vitro and in vivo, which were further supported by downregulated motility-related genes and epithelial-mesenchymal transition (EMT)-related proteins vimentin and N-cadherin. The obtained findings reveal the p38/MAPK pathway as a potential therapeutic target for TSCSCs and would provide profound implications for cancer therapy.

Mechanism of Reactive Oxygen Species-Guided Immune Responses in Gouty Arthritis and Potential Therapeutic Targets

Gouty arthritis (GA) is an inflammatory disease caused by monosodium urate (MSU) crystals deposited in the joint tissues causing severe pain. The disease can recur frequently and tends to form tophus in the joints. Current therapeutic drugs for the acute phase of GA have many side effects and limitations, are unable to prevent recurrent GA attacks and tophus formation, and overall efficacy is unsatisfactory. Therefore, we need to advance research on the microscopic mechanism of GA and seek safer and more effective drugs through relevant targets to block the GA disease process. Current research shows that the pathogenesis of GA is closely related to NLRP3 inflammation, oxidative stress, MAPK, NET, autophagy, and Ferroptosis. However, after synthesizing and sorting out the above mechanisms, it is found that the presence of ROS is throughout almost the entire spectrum of micro-mechanisms of the gout disease process, which combines multiple immune responses to form a large network diagram of complex and tight connections involved in the GA disease process. Current studies have shown that inflammation, oxidative stress, cell necrosis, and pathological signs of GA in GA joint tissues can be effectively suppressed by modulating ROS network-related targets. In this article, on the one hand, we investigated the generative mechanism of ROS network generation and its association with GA. On the other hand, we explored the potential of related targets for the treatment of gout and the prevention of tophus formation, which can provide effective reference ideas for the development of highly effective drugs for the treatment of GA.

Dual-Action Kinase Inhibitors Influence p38α MAP Kinase Dephosphorylation

Reversible protein phosphorylation directs essential cellular processes including cell division, cell growth, cell death, inflammation, and differentiation. Because protein phosphorylation drives diverse diseases, kinases and phosphatases have been targets for drug discovery, with some achieving remarkable clinical success. Most protein kinases are activated by phosphorylation of their activation loops, which shifts the conformational equilibrium of the kinase towards the active state. To turn off the kinase, protein phosphatases dephosphorylate these sites, but how the conformation of the dynamic activation loop contributes to dephosphorylation was not known. To answer this, we modulated the activation loop conformational equilibrium of human p38α ΜΑP kinase with existing kinase inhibitors that bind and stabilize specific inactive activation loop conformations. From this, we discovered three inhibitors that increase the rate of dephosphorylation of the activation loop phospho-threonine by the PPM serine/threonine phosphatase WIP1. Hence, these compounds are "dual-action" inhibitors that simultaneously block the active site and stimulate p38α dephosphorylation. Our X-ray crystal structures of phosphorylated p38α bound to the dual-action inhibitors reveal a shared flipped conformation of the activation loop with a fully accessible phospho-threonine. In contrast, our X-ray crystal structure of phosphorylated apo human p38α reveals a different activation loop conformation with an inaccessible phospho-threonine, thereby explaining the increased rate of dephosphorylation upon inhibitor binding. These findings reveal a conformational preference of phosphatases for their targets and suggest a new approach to achieving improved potency and specificity for therapeutic kinase inhibitors.

Synergistic effect of paeoniflorin combined with luteolin in alleviating Lipopolysaccharides-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is an acute multifactorial infectious disease caused by trauma, pneumonia, shock and sepsis. Paeoniae Radix Rubra (Paeonia lactiflora Pall. or Paeonia veitchii Lynch, Chishao in Chinese, CS) and Salviae Miltiorrhizae Radix et Rhizoma (Salvia miltiorrhiza Bge., Lamiaceae, Danshen in Chinese, DS) are common traditional Chinese medicines (TCMs). CS-DS herb pair has been widely used to promote blood circulation and eliminate blood stasis in Chinese clinical practice, appearing in a variety of prescriptions. However, it is still unclear for the effect and active ingredients of the herb pair on ALI.

AIM OF THE STUDY

The study investigated the effect and active ingredients of CS-DS herb pair and demonstrated the synergistic effect and mechanisms of the active ingredients.

MATERIALS AND METHODS

Lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cells and BALB/c mice were used to establish an ALI model to investigate the effect of CS-DS herb pair on ALI. Network pharmacology and molecular docking were used to analyze the active ingredients and potential mechanisms of the herb pair. The synergistic effects and mechanisms of active ingredients on ALI were validated by in vitro and in vivo experiments.

RESULTS

CS-DS herb pair had a synergistic effect on LPS-induced ALI. Based on the network pharmacology, the compounds paeoniflorin and luteolin were screened. Both paeoniflorin and luteolin had good affinity for NF-κB and MAPK by molecular docking. LPS stimulation of RAW264.7 cells resulted in a significant increase in ROS, NO, TNF-α, IL-6 and IL-1β, while the paeoniflorin combined with luteolin significantly reduced their expressions. In the LPS-induced ALI model, the combination also reduced the expression of inflammatory factors and oxidative stress levels. Furthermore, LPS activated the NF-κB and MAPK signaling pathways, whereas the combination decreased the expression of proteins in both pathways.

CONCLUSION

CS-DS herb pair alleviated LPS-induced ALI with the active ingredients paeoniflorin and luteolin, which suppressed inflammation and oxidative stress via regulation of NF-κB and MAPK signaling pathways.

JNK Signaling Positively Regulates Acute Ethanol Tolerance in C. elegans

Alcohol use disorder (AUD) is a chronic neurobehavioral condition characterized by a cycle of tolerance development, increased consumption, and reinstated craving and seeking behaviors during withdrawal. Understanding the intricate mechanisms of AUD necessitates reliable animal models reflecting its key features. Caenorhabditis elegans (C. elegans), with its conserved nervous system and genetic tractability, has emerged as a valuable model organism to study AUD. Here, we employ an ethanol vapor exposure model in Caenorhabditis elegans, recapitulating AUD features while maintaining high-throughput scalability. We demonstrate that ethanol vapor exposure induces intoxication-like behaviors, acute tolerance, and ethanol preference, akin to mammalian AUD traits. Leveraging this model, we elucidate the conserved role of c-jun N-terminal kinase (JNK) signaling in mediating acute ethanol tolerance. Mutants lacking JNK signaling components exhibit impaired tolerance development, highlighting JNK's positive regulation. Furthermore, we detect ethanol-induced JNK activation in C. elegans. Our findings underscore the utility of C. elegans with ethanol vapor exposure for studying AUD and offer novel insights into the molecular mechanisms underlying acute ethanol tolerance through JNK signaling.

Post-natal muscle growth and protein turnover: a narrative review of current understanding

A model explaining the dietary-protein-driven post-natal skeletal muscle growth and protein turnover in the rat is updated, and the mechanisms involved are described, in this narrative review. Dietary protein controls both bone length and muscle growth, which are interrelated through mechanotransduction mechanisms with muscle growth induced both from stretching subsequent to bone length growth and from internal work against gravity. This induces satellite cell activation, myogenesis and remodelling of the extracellular matrix, establishing a growth capacity for myofibre length and cross-sectional area. Protein deposition within this capacity is enabled by adequate dietary protein and other key nutrients. After briefly reviewing the experimental animal origins of the growth model, key concepts and processes important for growth are reviewed. These include the growth in number and size of the myonuclear domain, satellite cell activity during post-natal development and the autocrine/paracrine action of IGF-1. Regulatory and signalling pathways reviewed include developmental mechanotransduction, signalling through the insulin/IGF-1-PI3K-Akt and the Ras-MAPK pathways in the myofibre and during mechanotransduction of satellite cells. Likely pathways activated by maximal-intensity muscle contractions are highlighted and the regulation of the capacity for protein synthesis in terms of ribosome assembly and the translational regulation of 5-TOPmRNA classes by mTORC1 and LARP1 are discussed. Evidence for and potential mechanisms by which volume limitation of muscle growth can occur which would limit protein deposition within the myofibre are reviewed. An understanding of how muscle growth is achieved allows better nutritional management of its growth in health and disease.

TES and SLC40A1 as Potential Biomarkers for Predicting Survival in T-Cell Acute Lymphoblastic Leukemia

INTRODUCTION

Identifying patients with high-risk T-cell acute lymphoblastic leukemia (T-ALL) is crucial for personalized therapy; however, the lack of robust biomarkers hinders prognosis assessment. To address this issue, our study aimed to screen and validate genes whose expression may serve as predictive indicators of outcomes in T-ALL patients while also investigating the underlying molecular mechanisms.

METHODS

Differentially expressed genes (DEGs) between T-ALL patients and healthy controls were identified by integrating data from three independent public datasets. Functional annotation of these DEGs and protein-protein interactions were also conducted. Further, we enrolled a prospective cohort of T-ALL patients (n = 20) at our center, conducting RNA-seq analysis on their bone marrow samples. Survival-based univariate Cox analysis was employed to identify gene expressions related to survival, and an intersection algorithm was sequentially applied. Furthermore, we validated the identified genes using cases from the Therapeutically Applicable Research to Generate Effective Treatments database, plotting Kaplan-Meier curves for secondary validation.

RESULTS

Through the integration of survival-related genes with DEGs identified in T-ALL, our analysis revealed six T-ALL-specific genes, the expression levels of which were linked to prognostic value. Notably, the independent prognostic value of SLC40A1 and TES expression levels was confirmed in both an external cohort and a prospective cohort at our center.

CONCLUSION

In summary, our preliminary study indicates that the expression levels of TES and SLC40A1 genes show promise as potential indicators for predicting survival outcomes in T-ALL patients.

Interrogating endothelial barrier regulation by temporally resolved kinase network generation

Kinases are key players in endothelial barrier regulation, yet their temporal function and regulatory phosphosignaling networks are incompletely understood. We developed a novel methodology, Temporally REsolved KInase Network Generation (TREKING), which combines a 28-kinase inhibitor screen with machine learning and network reconstruction to build time-resolved, functional phosphosignaling networks. We demonstrated the utility of TREKING for identifying pathways mediating barrier integrity after activation by thrombin with or without TNF preconditioning in brain endothelial cells. TREKING predicted over 100 kinases involved in barrier regulation and discerned complex condition-specific pathways. For instance, the MAPK-activated protein kinase 2 (MAPKAPK2/MK2) had early barrier-weakening activity in both inflammatory conditions but late barrier-strengthening activity exclusively with thrombin alone. Using temporal Western blotting, we confirmed that MAPKAPK2/MK2 was differentially phosphorylated under the two inflammatory conditions. We further showed with lentivirus-mediated knockdown of MAPK14/p38α and drug targeting the MAPK14/p38α-MAPKAPK2/MK2 complex that a MAP3K20/ZAK-MAPK14/p38α axis controlled the late activation of MAPKAPK2/MK2 in the thrombin-alone condition. Beyond the MAPKAPK2/MK2 switch, TREKING predicts extensive interconnected networks that control endothelial barrier dynamics.

Establishing chronic models of age-related macular degeneration via long-term iron ion overload

Age-related macular degeneration (AMD) is characterized by the degenerative senescence in the retinal pigment epithelium (RPE) and photoreceptors, which is accompanied by the accumulation of iron ions in the aging retina. However, current models of acute oxidative stress are still insufficient to simulate the gradual progression of AMD. To address this, we established chronic injury models by exposing the aRPE-19 cells, 661W cells, and mouse retina to iron ion overload over time. Investigations at the levels of cell biology and molecular biology were performed. It was demonstrated that long-term treatment of excessive iron ions induced senescence-like morphological changes, decreased cell proliferation, and impaired mitochondrial function, contributing to apoptosis. Activation of the mitogen-activated protein kinase (MAPK) pathway and the downstream molecules were confirmed both in the aRPE-19 and 661W cells. Furthermore, iron ion overload resulted in dry AMD-like lesions and decreased visual function in the mouse retina. These findings suggest that chronic exposure to overloading iron ions plays a significant role in the pathogenesis of retinopathy and provide a potential model for future studies on AMD.NEW & NOTEWORTHY To explore the possibility of constructing reliable research carriers on age-related macular degeneration (AMD), iron ion overload was applied to establish models in vitro and in vivo. Subsequent investigations into cellular physiology and molecular biology confirmed the presence of senescence in these models. Through this study, we hope to provide a better option of feasible methods for future researches into AMD.

Sishen Pill and its active phytochemicals in treating inflammatory bowel disease and colon cancer: an overview

The incidence of inflammatory bowel disease (IBD) and the associated risk of colon cancer are increasing globally. Traditional Chinese medicine (TCM) treatment has unique advantages. The Sishen Pill, a common Chinese patented drug used to treat abdominal pain and diarrhea, consists mainly of Psoraleae Fructus, Myristicae Semen, Euodiae Fructus, and Schisandra Chinensis. Modern research has confirmed that Sishen Pill and its active secondary metabolites, such as psoralen, myristicin, evodiamine, and schisandrin, can improve intestinal inflammation and exert antitumor pharmacological effects. Common mechanisms in treating IBD and colon cancer mainly include regulating inflammation-related signaling pathways such as nuclear factor-kappa B, mitogen-activated protein kinase, phosphatidylinositol 3-kinase, NOD-like receptor heat protein domain-related protein 3, and wingless-type MMTV integration site family; NF-E2-related factor 2 and hypoxia-inducible factor 1α to inhibit oxidative stress; mitochondrial autophagy and endoplasmic reticulum stress; intestinal immune cell differentiation and function through the Janus kinase/signal transducer and activator of transcription pathway; and improving the gut microbiota and intestinal barrier. Overall, existing evidence suggests the potential of the Sishen pill to improve IBD and suppress inflammation-to-cancer transformation. However, large-scale randomized controlled clinical studies and research on the safety of these clinical applications are urgently required.

Exercise couples mitochondrial function with skeletal muscle fiber type via ROS-mediated epigenetic modification

Skeletal muscle is a heterogeneous tissue composed of different types of muscle fibers, demonstrating substantial plasticity. Physiological or pathological stimuli can induce transitions in muscle fiber types. However, the precise regulatory mechanisms behind these transitions remains unclear. This paper reviews the classification and characteristics of muscle fibers, along with the classical mechanisms of muscle fiber type transitions. Additionally, the role of exercise-induced muscle fiber type transitions in disease intervention is reviewed. Epigenetic pathways mediate cellular adaptations and thus represent potential targets for regulating muscle fiber type transitions. This paper focuses on the mechanisms by which epigenetic modifications couple mitochondrial function and contraction characteristics. Reactive Oxygen Species (ROS) are critical signaling regulators for the health-promoting effects of exercise. Finally, we discuss the role of exercise-induced ROS in regulating epigenetic modifications and the transition of muscle fiber types.

The effect of STAT1, miR-99b, and MAP2K1 in alcoholic liver disease (ALD) mouse model and hepatocyte

Alcoholic liver disease (ALD) serves as the leading cause of chronic liver diseases-related morbidity and mortality, which threatens the life of millions of patients in the world. However, the molecular mechanisms underlying ALD progression remain unclear. Here, we applied microarray analysis and experimental approaches to identify miRNAs and related regulatory signaling that associated with ALD. Microarray analysis identified that the expression of miR-99b was elevated in the ALD mouse model. The AML-12 cells were treated with EtOH and the expression of miR-99b was enhanced in the cells. The expression of miR-99b was positively correlated with ALT levels in the ALD mice. The microarray analysis identified the abnormally expressed mRNAs in ALD mice and the overlap analysis was performed with based on the differently expressed mRNAs and the transcriptional factors of miR-99b, in which STAT1 was identified. The elevated expression of STAT1 was validated in ALD mice. Meanwhile, the treatment of EtOH induced the expression of STAT1 in the AML-12 cells. The expression of STAT1 was positively correlated with ALT levels in the ALD mice. The positive correlation of STAT1 and miR-99b expression was identified in bioinformatics analysis and ALD mice. The expression of miR-99b and pri-miR-99b was promoted by the overexpression of STAT1 in AML-12 cells. ChIP analysis confirmed the enrichment of STAT1 on miR-99b promoter in AML-12 cells. Next, we found that the expression of mitogen-activated protein kinase kinase 1 (MAP2K1) was negatively associated with miR-99b. The expression of MAP2K1 was downregulated in ALD mice. Consistently, the expression of MAP2K1 was reduced by the treatment of EtOH in AML-12 cells. The expression of MAP2K1 was negative correlated with ALT levels in the ALD mice. We identified the binding site of MAP2K1 and miR-99b. Meanwhile, the treatment of miR-99b mimic repressed the luciferase activity of MAP2K1 in AML-12 cells. The expression of MAP2K1 was suppressed by miR-99b in the cells. We observed that the expression of MAP2K1 was inhibited by the overexpression of STAT1 in AML-12 cells. Meanwhile, the apoptosis of AML-12 cells was induced by the treatment of EtOH, while miR-99b mimic promoted but the overexpression of MAP2K1 attenuated the effect of EtOH in the cells. In conclusion, we identified the correlation and effect of STAT1, miR-99b, and MAP2K1 in ALD mouse model and hepatocyte. STAT1, miR-99b, and MAP2K1 may serve as potential therapeutic target of ALD.

Puerarin Ameliorated PCOS through Preventing Mitochondrial Dysfunction Dependent on the Maintenance of Intracellular Calcium Homeostasis

Polycystic ovarian syndrome (PCOS) is the major cause of infertility in reproductive women, but no universal drug is feasible. Although puerarin clinically treats cerebrovascular and cardiovascular diseases, its curative effect on PCOS remains elusive. The present study discovered that administration of puerarin restored estrous cycle of PCOS mice and diminished the number of cystic follicles with the concomitant recovery for circulating testosterone, LH and FSH levels, and LH/FSH ratio, indicating the therapeutic role of puerarin in PCOS. KEGG analysis of differential genes between PCOS and control revealed the enrichment in MAPK and calcium signaling pathway. Application of puerarin restricted the phosphorylation of ERK1/2 and JNK, whose activation neutralized the improvement of puerarin on the secretory function and apoptosis of ovarian granulosa cells (GCs). Meanwhile, puerarin alleviated the accumulation of cytosolic Ca2+ through restricting the opening of Ryr and Itpr channels, but this effectiveness was counteracted by the activatory ERK1/2 and JNK. Attenuation of cytosolic Ca2+ counteracted the antagonistic effects of ERK1/2 and JNK activation on puerarin's role in rescuing the calcineurin and Nfatc. Further analysis manifested that Mcu had been authenticated as a direct downstream target of Nfatc to mediate the amelioration of puerarin on mitochondrial Ca2+ uptake. Moreover, puerarin prevented the disorder of ATP content, mitochondrial membrane potential, and mitochondrial permeability transition pore opening through maintaining mitochondrial Ca2+ homeostasis. Collectively, puerarin might ameliorate the symptoms of PCOS mice through preventing mitochondrial dysfunction that is dependent on the maintenance of intracellular Ca2+ homeostasis after inactivation of ERK1/2 and JNK.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Triazolo[4,5-d]pyrimidin-5-amines based ERK3 inhibitors fail to demonstrate selective effects on adipocyte function

Extracellular signal-regulated kinase 3 (ERK3 also designated MAPK6 - mitogen-activated protein kinase 6) is a ubiquitously expressed kinase participating in the regulation of a broad spectrum of physiological and pathological processes. Targeted inhibition of the kinase may allow the development of novel treatment strategies for a variety of types of cancer and somatic pathologies, as well as preserving metabolic health, combat obesity and diabetes. We chose and synthesized three triazolo [4,5-d]pyrimidin-5-amines proposed previously as putative ERK3 inhibitors to assess their selectivity and biological effects in terms of metabolic state impact in living cells. As it was previously shown that ERK3 is a major regulator of lipolysis in adipocytes, we focused on this process. Our new results indicate that in addition to the previously identified lipolytic enzyme ATGL, ERK3 also regulates hormone-sensitive lipase (HSL) and monoglyceride lipase (MGL). Moreover, this kinase also promotes the abundance of fatty acid synthase (FASN) as well as protein kinase cAMP-activated catalytic subunit alpha (PKACα). To investigate various effects of putative ERK3 inhibitors on lipolysis, we utilized different adipocyte models. We demonstrated that molecules exhibit lipolysis-modulating effects; however, the effects of triazolo [4,5-d]pyrimidin-5-amines based inhibitors on lipolysis are not dependent on ERK3. Subsequently, we revealed a wide range of the compounds' possible targets using a machine learning-based prediction. Therefore, the tested compounds inhibit ERK3 in vitro, but the biological effect of this inhibition is significantly overlapped and modified by some other molecular events related to the non-selective binding to other targets.

Resveratrol Inhibits Nasopharyngeal Carcinoma (NPC) by Targeting the MAPK Signaling Pathway

BACKGROUND

With conventional cancer treatments facing limitations, interest in plant-derived natural products as potential alternatives is increasing. Although resveratrol has demonstrated antitumor effects in various cancers, its impact and mechanism on nasopharyngeal carcinoma remain unclear.

OBJECTIVE

This study aimed to systematically investigate the anti-cancer effects of resveratrol on nasopharyngeal carcinoma using a combination of experimental pharmacology, network pharmacology, and molecular docking approaches.

METHODS

CCK-8, scratch wound, and transwell assays were employed to confirm the inhibitory effect of resveratrol on the proliferation, migration, and invasion of nasopharyngeal carcinoma cells. H&E and TUNEL stainings were used to observe the morphological changes and apoptosis status of resveratrol-treated cells. The underlying mechanisms were elucidated using a network pharmacology approach. Immunohistochemistry and Western blotting were utilized to validate key signaling pathways.

RESULTS

Resveratrol inhibited the proliferation, invasion, and migration of nasopharyngeal carcinoma cells, ultimately inducing apoptosis in a time- and dose-dependent manner. Network pharmacology analysis revealed that resveratrol may exert its anti-nasopharyngeal carcinoma effect mainly through the MAPK pathway. Immunohistochemistry results from clinical cases showed MAPK signaling activation in nasopharyngeal carcinoma tissues compared to adjacent tissues. Western blotting validated the targeting effect of resveratrol, demonstrating significant inhibition of the MAPK signaling pathway. Furthermore, molecular docking supported its multi-target role with MAPK, TP53, PIK3CA, SRC, etc. Conclusion: Resveratrol has shown promising potential in inhibiting human nasopharyngeal carcinoma cells by primarily targeting the MAPK pathway. These findings position resveratrol as a potential therapeutic agent for nasopharyngeal carcinoma.

Biological Roles and Pathogenic Mechanisms of LncRNA MIR4435-2HG in Cancer: A Comprehensive Review

The long non-coding RNA MIR4435-2HG has been confirmed to play a crucial regulatory role in various types of tumors. As a novel type of non-coding RNA, MIR4435-2HG plays a key role in regulating the expression of tumor-related genes, interfering with cellular signaling pathways, and affecting tumor immune evasion. Its unique structure allows it to regulate the expression of various tumor-related genes through different pathways, participating in the regulation of tumor signaling pathways, such as regulating the expression of oncogenes and tumor suppressor genes, influencing the biological behaviors of proliferation, metastasis, and apoptosis in tumors. Numerous studies have found a high expression of MIR4435-2HG in various tumor tissues, closely related to the clinical pathological characteristics of tumors, such as staging, lymph node metastasis and prognosis. Some studies have discovered that MIR4435-2HG can regulate the sensitivity of tumor cells to chemotherapy drugs, affecting tumor cell drug resistance. This provides new insights into overcoming tumor drug resistance by regulating MIR4435-2HG. Therefore, studying its molecular mechanisms, expression regulation, and its relationship with the clinical features of tumors is of great significance for revealing the mechanisms of tumor occurrence and developing new therapeutic targets.

Examination of the mechanism of Piezo ion channel in 5-HT synthesis in the enterochromaffin cell and its association with gut motility

In the gastrointestinal tract, serotonin (5-hydroxytryptamine, 5-HT) is an important monoamine that regulates intestinal dynamics. QGP-1 cells are human-derived enterochromaffin cells that secrete 5-HT and functionally express Piezo ion channels associated with cellular mechanosensation. Piezo ion channels can be blocked by Grammostola spatulata mechanotoxin 4 (GsMTx4), a spider venom peptide that inhibits cationic mechanosensitive channels. The primary aim of this study was to explore the effects of GsMTx4 on 5-HT secretion in QGP-1 cells in vitro. We investigated the transcript and protein levels of the Piezo1/2 ion channel, tryptophan hydroxylase 1 (TPH1), and mitogen-activated protein kinase signaling pathways. In addition, we observed that GsMTx4 affected mouse intestinal motility in vivo. Furthermore, GsMTx4 blocked the response of QGP-1 cells to ultrasound, a mechanical stimulus.The prolonged presence of GsMTx4 increased the 5-HT levels in the QGP-1 cell culture system, whereas Piezo1/2 expression decreased, and TPH1 expression increased. This effect was accompanied by the increased phosphorylation of the p38 protein. GsMTx4 increased the entire intestinal passage time of carmine without altering intestinal inflammation. Taken together, inhibition of Piezo1/2 can mediate an increase in 5-HT, which is associated with TPH1, a key enzyme for 5-HT synthesis. It is also accompanied by the activation of the p38 signaling pathway. Inhibitors of Piezo1/2 can modulate 5-HT secretion and influence intestinal motility.

Autophagy in sepsis-induced acute lung injury: Friend or foe?

Sepsis-induced acute lung injury (ALI) is a life-threatening syndrome with high mortality and morbidity, resulting in a heavy burden on family and society. As a key factor that maintains cellular homeostasis, autophagy is regarded as a self-digesting process by which damaged organelles and useless proteins are recycled for cell metabolism, and it thus plays a crucial role during physiological and pathological processes. Recent studies have indicated that autophagy is involved in the pathophysiological process of sepsis-induced ALI, including cell apoptosis, inflammation, and mitochondrial dysfunction, which indicates that regulating autophagy may be beneficial for this disease. However, the role of autophagy in the etiology and treatment of sepsis-induced ALI is not well characterized. This review summarizes the autophagy-related signaling pathways in sepsis-induced ALI, as well as focuses on the dual role of autophagy and its regulation by non-coding RNAs during disease progression, for the development of potential therapeutic strategies in this disease.

Potential effects of biomaterials on macrophage function and their signalling pathways

The use of biomaterials in biomedicine and healthcare has increased in recent years. Macrophages are the primary immune cells that induce inflammation and tissue repair after implantation of biomaterials. Given that macrophages exhibit high heterogeneity and plasticity, the influence of biomaterials on macrophage phenotype should be considered a crucial evaluation criterion during the development of novel biomaterials. This review provides a comprehensive summary of the physicochemical, biological, and dynamic characteristics of biomaterials that drive the regulation of immune responses in macrophages. The mechanisms involved in the interaction between macrophages and biomaterials, including endocytosis, receptors, signalling pathways, integrins, inflammasomes and long non-coding RNAs, are summarised in this review. In addition, research prospects of the interaction between macrophages and biomaterials are discussed. An in-depth understanding of mechanisms underlying the spatiotemporal changes in macrophage phenotype induced by biomaterials and their impact on macrophage polarization can facilitate the identification and development of novel biomaterials with superior performance. These biomaterials may be used for tissue repair and regeneration, vaccine or drug delivery and immunotherapy.

Carbon dioxide and MAPK signalling: towards therapy for inflammation

Inflammation, although necessary to fight infections, becomes a threat when it exceeds the capability of the immune system to control it. In addition, inflammation is a cause and/or symptom of many different disorders, including metabolic, neurodegenerative, autoimmune and cardiovascular diseases. Comorbidities and advanced age are typical predictors of more severe cases of seasonal viral infection, with COVID-19 a clear example. The primary importance of mitogen-activated protein kinases (MAPKs) in the course of COVID-19 is evident in the mechanisms by which cells are infected with SARS-CoV-2; the cytokine storm that profoundly worsens a patient's condition; the pathogenesis of diseases, such as diabetes, obesity, and hypertension, that contribute to a worsened prognosis; and post-COVID-19 complications, such as brain fog and thrombosis. An increasing number of reports have revealed that MAPKs are regulated by carbon dioxide (CO2); hence, we reviewed the literature to identify associations between CO2 and MAPKs and possible therapeutic benefits resulting from the elevation of CO2 levels. CO2 regulates key processes leading to and resulting from inflammation, and the therapeutic effects of CO2 (or bicarbonate, HCO3-) have been documented in all of the abovementioned comorbidities and complications of COVID-19 in which MAPKs play roles. The overlapping MAPK and CO2 signalling pathways in the contexts of allergy, apoptosis and cell survival, pulmonary oedema (alveolar fluid resorption), and mechanical ventilation-induced responses in lungs and related to mitochondria are also discussed. Video Abstract.

Anti-oxidant and Anti-inflammatory Effects of Ethanol Extract from Polygala sibirica L. var megalopha Fr. on Lipopolysaccharide-Stimulated RAW264.7 Cells

OBJECTIVE

To investigate the anti-oxidant and anti-inflammatory effects of ethanol extract of Polygala sibirica L. var megalopha Fr. (EEP) on RAW264.7 mouse macrophages.

METHODS

RAW264.7 cells were pretreated with 0-200 µg/mL EEP or vehicle for 2 h prior to exposure to 1 µg/mL lipopolysaccharide (LPS) for 24 h. Nitric oxide (NO) and prostaglandin (PGE2) production were determined by Griess reagent and enzyme-linked immunosorbent assay (ELISA), respectively. The mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin-1beta (IL-1β), and IL-6 were determined using reverse transcription polymerase chain reaction (RT-PCR). Western blot assay was used to determine the protein expressions of iNOS, COX-2, phosphorylation of extracellular regulated protein kinases (ERK1/2), c-Jun N-terminal kinase (JNK), inhibitory subunit of nuclear factor Kappa B alpha (Iκ B-α) and p38. Immunofluorescence was used to observe the nuclear expression of nuclear factor-κ B p65 (NF-κ B p65). Additionally, the anti-oxidant potential of EEP was evaluated by reactive oxygen species (ROS) production and the activities of catalase (CAT) and superoxide dismutase (SOD). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), superoxide anion (O2-) radical and nitrite scavenging activity were also measured.

RESULTS

The total polyphenol and flavonoid contents of EEP were 23.50±2.16 mg gallic acid equivalent/100 g and 43.78±3.81 mg rutin equivalent/100 g. With EEP treatment (100 and 150 µg/mL), there was a notable decrease in NO and PGE2 production induced by LPS in RAW264.7 cells by downregulation of iNOS and COX-2 mRNA and protein expressions (P<0.01 or P<0.05). Furthermore, with EEP treatment (150 µg/mL), there was a decrease in the mRNA expression levels of TNF-α, IL-1β and IL-6, as well as in the phosphorylation of ERK, JNK and p38 mitogen-activated protein kinase (MAPK, P<0.01 or P<0.05), by blocking the nuclear translocation of NF-κ B p65 in LPS-stimulated cells. In addition, EEP (100 and 150 µg/mL) led to an increase in the anti-oxidant enzymes activity of SOD and CAT, with a concomitant decrease in ROS production (P<0.01 or P<0.05). EEP also indicated the DPPH, OH, O2- radical and nitrite scavenging activity.

CONCLUSION

EEP inhibited inflammatory responses in activated macrophages through blocking MAPK/NF-κ B pathway and protected against oxidative stress.

Deciphering the Mysterious Relationship between the Cross-Pathogenetic Mechanisms of Neurodegenerative and Oncological Diseases

The relationship between oncological pathologies and neurodegenerative disorders is extremely complex and is a topic of concern among a growing number of researchers around the world. In recent years, convincing scientific evidence has accumulated that indicates the contribution of a number of etiological factors and pathophysiological processes to the pathogenesis of these two fundamentally different diseases, thus demonstrating an intriguing relationship between oncology and neurodegeneration. In this review, we establish the general links between three intersecting aspects of oncological pathologies and neurodegenerative disorders, i.e., oxidative stress, epigenetic dysregulation, and metabolic dysfunction, examining each process in detail to establish an unusual epidemiological relationship. We also focus on reviewing the current trends in the research and the clinical application of the most promising chemical structures and therapeutic platforms that have a modulating effect on the above processes. Thus, our comprehensive analysis of the set of molecular determinants that have obvious cross-functional pathways in the pathogenesis of oncological and neurodegenerative diseases can help in the creation of advanced diagnostic tools and in the development of innovative pharmacological strategies.

The CBL1/9-CIPK1 calcium sensor negatively regulates drought stress by phosphorylating the PYLs ABA receptor

The stress hormone, Abscisic acid (ABA), is crucial for plants to respond to changes in their environment. It triggers changes in cytoplasmic Ca2+ levels, which activate plant responses to external stresses. However, how Ca2+ sensing and signaling feeds back into ABA signaling is not well understood. Here we reveal a calcium sensing module that negatively regulates drought stress via modulating ABA receptor PYLs. Mutants cbl1/9 and cipk1 exhibit hypersensitivity to ABA and drought resilience. Furthermore, CIPK1 is shown to interact with and phosphorylate 7 of 14 ABA receptors at the evolutionarily conserved site corresponding to PYL4 Ser129, thereby suppressing their activities and promoting PP2C activities under normal conditions. Under drought stress, ABA impedes PYLs phosphorylation by CIPK1 to respond to ABA signaling and survive in unfavorable environment. These findings provide insights into a previously unknown negative regulatory mechanism of the ABA signaling pathway, which is mediated by CBL1/9-CIPK1-PYLs, resulting in plants that are more sensitive to drought stress. This discovery expands our knowledge about the interplay between Ca2+ signaling and ABA signaling.

p38MAPK/MK2 signaling stimulates host cells autophagy pathways to restrict Salmonella infection

Autophagy plays an important role in recognizing and protecting cells from invading intracellular pathogens such as Salmonella. In this work, we investigated the role of p38MAPK/MK2 in modulating the host cell susceptibility to Salmonella infection. Inhibition of p38MAPK or MK2 led to a significant increase of bacterial counts in Salmonella infected mouse embryonic fibroblasts (MEFs), as well as in MK2-deficient (Mk2-/-) cells. Furthermore, western blot analysis showed that Mk2-/- cells have lower level of LC3 lipidation, which is the indicator of general autophagy compared to Mk2-rescued cells. In Mk2-/- cells, we also observed lower activated TANK-binding kinase-1 phosphorylation on Ser172 and p62/SQTM1-Ser403 phosphorylation, which are important to promote the translocation of p62 to ubiquitinated microbes and required for efficient autophagy of bacteria. Furthermore, immunofluorescence analysis revealed reduced colocalization of Salmonella with LC3 and p62 in MEFs. Inhibition of autophagy with bafilomycin A1 showed increased bacterial counts in treated cells compared to control cell. Overall, these results indicate that p38MAPK/MK2-mediated protein phosphorylation modulates the host cell susceptibility to Salmonella infection by affecting the autophagy pathways.

The emerging roles of MAPK-AMPK in ferroptosis regulatory network

Ferroptosis, a newform of programmed cell death, driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes and is extremely dependent on iron ions, which is differs characteristics from traditional cell death has attracted greater attention. Based on the curiosity of this new form of regulated cell death, there has a tremendous progress in the field of mechanistic understanding of ferroptosis recent years. Ferroptosis is closely associated with the development of many diseases and involved in many diseases related signaling pathways. Not only a variety of oncoproteins and tumor suppressors can regulate ferroptosis, but multiple oncogenic signaling pathways can also have a regulatory effect on ferroptosis. Ferroptosis results in the accumulation of large amounts of lipid peroxides thus involving the onset of oxidative stress and energy stress responses. The MAPK pathway plays a critical role in oxidative stress and AMPK acts as a sensor of cellular energy and is involved in the regulation of the energy stress response. Moreover, activation of AMPK can induce the occurrence of autophagy-dependent ferroptosis and p53-activated ferroptosis. In recent years, there have been new advances in the study of molecular mechanisms related to the regulation of ferroptosis by both pathways. In this review, we will summarize the molecular mechanisms by which the MAPK-AMPK signaling pathway regulates ferroptosis. Meanwhile, we sorted out the mysterious relationship between MAPK and AMPK, described the crosstalk among ferroptosis and MAPK-AMPK signaling pathways, and summarized the relevant ferroptosis inducers targeting this regulatory network. This will provide a new field for future research on ferroptosis mechanisms and provide a new vision for cancer treatment strategies. Video Abstract.

PME-1 sensitizes glioblastoma cells to oxidative stress-induced cell death by attenuating PP2A-B55α-mediated inactivation of MAPKAPK2-RIPK1 signaling

Glioblastoma (GBM) is the most common primary brain tumor in adults. Current standard therapy is surgery followed by radiotherapy, with concurrent and adjuvant temozolomide chemotherapy. GBM is characterized by almost uniformly fatal outcomes, highlighting the unmet clinical need for more efficient, biomarker-guided treatments. Protein phosphatase methylesterase-1 (PME-1), a regulator of the tumor suppressive phosphatase PP2A, promotes PP2A demethylation and inactivation, and is overexpressed in 44% of GBM, associated with increased tumor grade and cellular proliferation. Here, we aimed to investigate how reactive oxygen species (ROS), a frequent by-product of radiotherapy and temozolomide chemotherapy, regulate PP2A function via its methylesterase PME-1, and how PME-1 overexpression impacts the response of GBM cells to oxidative stress. We found that in two glioblastoma cell lines, U87MG and U251MG, expression of PME-1 is positively correlated with the sensitivity of the cells to H₂O₂ or t-BHP-induced oxidative stress. Experiments using the irreversible pharmacologic PME-1 inhibitor, AMZ30, and different PME-1 mutants, revealed that the methylesterase function, the PP2A binding capacity, and the nuclear localization of PME-1 are all important for the sensitizing effect of PME-1 expression. Furthermore, we identified increased nuclear localization of the PP2A-B55α subunit, increased binding of PP2A-B55α to PME-1, and increased B55α-bound PP2A-C demethylation upon oxidative stress. Lastly, we uncovered increased stress-induced phosphorylation and activity of MAPKAPK2 and RIPK1 in PME-1 overexpressing U87MG cells, which caused the observed sensitization to t-BHP treatment. Our data reveal a novel role for PME-1 in oxidative stress-induced GBM cell death, regulating nuclear PP2A-B55α activity and MAPKAPK2-RIPK1 signaling. Patients with GBM tumors overexpressing PME-1, although having a worse prognosis due to increased cellular proliferation of the tumor, could actually be more responsive to oxidative stress-inducing therapies.

SENP3-mediated deSUMOylation of c-Jun facilitates microglia-induced neuroinflammation after cerebral ischemia and reperfusion injury

Recent evidences have implicated that SENP3 is a deSUMOylase which possesses neuronal damage effects in cerebral ischemia. However, its role in microglia remains poorly understood. Here, we found that SENP3 was upregulated in the peri-infarct areas of mice following ischemic stroke. Furthermore, knockdown of SENP3 significantly inhibits the expression of proinflammatory cytokines and chemokines in microglial cells. Mechanistically, SENP3 can bind and then mediated the deSUMOylation of c-Jun, which activated its transcriptional activity, ultimately followed by the activation of MAPK/AP-1 signaling pathway. In addition, microglia-specific SENP3 knockdown alleviated ischemia-induced neuronal damage, and markedly diminished infract volume, ameliorated sensorimotor and cognitive function in animals subjected to ischemic stroke. These results indicated SENP3 functions as a novel regulator of microglia-induced neuroinflammation by activating the MAPK/AP-1 signaling pathway via mediating the deSUMOylation of c-Jun. Interventions of SENP3 expression or its interaction with c-Jun would be a new and promising therapeutic strategy for ischemic stroke.

A comprehensive review of stroke-related signaling pathways and treatment in western medicine and traditional Chinese medicine

This review provides insight into the complex network of signaling pathways and mechanisms involved in stroke pathophysiology. It summarizes the historical progress of stroke-related signaling pathways, identifying potential interactions between them and emphasizing that stroke is a complex network disease. Of particular interest are the Hippo signaling pathway and ferroptosis signaling pathway, which remain understudied areas of research, and are therefore a focus of the review. The involvement of multiple signaling pathways, including Sonic Hedgehog (SHH), nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), hypoxia-inducible factor-1α (HIF-1α), PI3K/AKT, JAK/STAT, and AMPK in pathophysiological mechanisms such as oxidative stress and apoptosis, highlights the complexity of stroke. The review also delves into the details of traditional Chinese medicine (TCM) therapies such as Rehmanniae and Astragalus, providing an analysis of the recent status of western medicine in the treatment of stroke and the advantages and disadvantages of TCM and western medicine in stroke treatment. The review proposes that since stroke is a network disease, TCM has the potential and advantages of a multi-target and multi-pathway mechanism of action in the treatment of stroke. Therefore, it is suggested that future research should explore more treasures of TCM and develop new therapies from the perspective of stroke as a network disease.