Mitogen-activated protein kinase: conservation of a three-kinase module from yeast to human

The STING antagonist SN-011 ameliorates cisplatin induced acute kidney injury via suppression of STING/NF-κB-mediated inflammation

Acute kidney injury (AKI) is a critical clinical syndrome associated with both innate and adaptive immune responses and thus increases mortality. Nevertheless, specific therapeutics for AKI are scarce so far. Recent studies have revealed that knockout of STING alleviate AKI, suggesting that STING could be an attractive target for AKI therapy. SN-011, a promising STING inhibitor, has not been reported in studies of its anti-AKI activity. In this study, we sought to examine the effects of SN-011 on AKI and explore its underlying mechanism. Our findings indicate that SN-011 could modulate the NF-κB and MAPK pathways, suppress the expression of inflammatory factors, and decrease ROS release in the cisplatin-induced cell model. In addition, SN-011 blocked the nuclear translocation of NF-κB p65, further mitigating the inflammatory response. In vivo, SN-011 enhanced survival rates and alleviated renal dysfunction. According to gene set enrichment analysis of sequencing data from mouse kidneys, we further confirm that SN-011 modulates the NF-κB and MAPK pathways. Our study suggests that SN-011 could be an attractive anti-inflammatory agent for further anti-AKI research.

Restoration of Sestrin 3 Expression Mitigates Cardiac Oxidative Damage in Ischemia-Reperfusion Injury Model

Cardiac ischemia-reperfusion injury (IRI) occurs when blood flow is restored to the myocardium after a period of ischemia, leading to oxidative stress and subsequent myocardial cell damage, primarily due to the accumulation of reactive oxygen species (ROS). In our previous research, we identified that miR-25 is significantly overexpressed in pressure overload-induced heart failure, and its inhibition improves cardiac function by restoring the expression of SERCA2a, a key protein involved in calcium regulation. In this study, we aimed to investigate the role of miR-25 in the context of ischemia-reperfusion injury. We found that miR-25 was markedly upregulated under hypoxic conditions in both in vitro and in vivo models. Through in silico analysis, we identified Sestrin3 (SESN3), an antioxidant protein known for its protective effects against oxidative stress, as a novel target of miR-25. Based on these findings, we hypothesized that inhibiting miR-25 would restore Sestrin3 expression, thereby reducing ROS-induced myocardial cell damage and improving cardiac function. To test this hypothesis, we employed two model systems: a hypoxia/reoxygenation (H/R) stress model using H9c2 myoblasts and a surgically induced ischemia-reperfusion injury mouse model. Our results demonstrated that the use of miR-25 inhibitors significantly improved cardiac function and reduced myocardial damage in both models through the restoration of SESN3 expression. In conclusion, our findings suggest that targeting miR-25 may serve as a novel therapeutic modality to alleviate oxidative damage in the heart.

Emerging regulatory mechanisms and functions of biomolecular condensates: implications for therapeutic targets

Cells orchestrate their processes through complex interactions, precisely organizing biomolecules in space and time. Recent discoveries have highlighted the crucial role of biomolecular condensates-membrane-less assemblies formed through the condensation of proteins, nucleic acids, and other molecules-in driving efficient and dynamic cellular processes. These condensates are integral to various physiological functions, such as gene expression and intracellular signal transduction, enabling rapid and finely tuned cellular responses. Their ability to regulate cellular signaling pathways is particularly significant, as it requires a careful balance between flexibility and precision. Disruption of this balance can lead to pathological conditions, including neurodegenerative diseases, cancer, and viral infections. Consequently, biomolecular condensates have emerged as promising therapeutic targets, with the potential to offer novel approaches to disease treatment. In this review, we present the recent insights into the regulatory mechanisms by which biomolecular condensates influence intracellular signaling pathways, their roles in health and disease, and potential strategies for modulating condensate dynamics as a therapeutic approach. Understanding these emerging principles may provide valuable directions for developing effective treatments targeting the aberrant behavior of biomolecular condensates in various diseases.

N-methyl-D-aspartate Receptor Subunits 2A and 2B Mediate Connexins and Pannexins in the Trigeminal Ganglion Involved in Orofacial Inflammatory Allodynia during Temporomandibular Joint Inflammation

Temporomandibular joint osteoarthritis (TMJOA) is a severe form of temporomandibular joint disorders (TMD), and orofacial inflammatory allodynia is one of its common symptoms which lacks effective treatment. N-methyl-D-aspartate receptor (NMDAR), particularly its subtypes GluN2A and GluN2B, along with gap junctions (GJs), are key players in the mediation of inflammatory pain. However, the precise regulatory mechanisms of GluN2A, GluN2B, and GJs in orofacial inflammatory allodynia during TMJ inflammation still remain unclear. Here, we established the TMJ inflammation model by injecting Complete Freund's adjuvant (CFA) into the TMJ and used Cre/loxp site-specific recombination system to conditionally knock out (CKO) GluN2A and GluN2B in the trigeminal ganglion (TG). Von-frey test results indicated that CFA-induced mechanical allodynia in the TMJ region was relieved in GluN2A and GluN2B deficient mice. In vivo, CFA significantly up-regulated the expression of GluN2A and GluN2B, Gjb1, Gjb2, Gjc2 and Panx3 in the TG, and GluN2A and GluN2B CKO played different roles in mediating the expression of Gjb1, Gjb2, Gjc2 and Panx3. In vitro, NMDA up-regulated the expression of Gjb1, Gjb2, Gjc2 and Panx3 in satellite glial cells (SGCs) as well as promoted the intercellular communication between SGCs, and GluN2A and GluN2B knocking down (KD) altered the expression and function differently. NMDAR regulated Gjb1 and Panx3 through ERK1/2 pathway, and mediated Gjb2 and Gjc2 through MAPK, PKA, and PKC intracellular signaling pathways. These findings shed light on the distinct functions of GluN2A and GluN2B in mediating peripheral sensitization induced by TMJ inflammation in the TG, offering potential therapeutic targets for managing orofacial inflammatory allodynia.

Identification of the MAP4K gene family reveals GhMAP4K13 regulates drought and salt stress tolerance in cotton

Mitogen-activated protein kinase kinase kinase kinases (MAP4Ks) are a class of highly conserved serine/threonine-protein kinases in eukaryotes. They participate in the typical MAPK cascade system and various signal transduction pathways regulating biological processes in plants, during stressful conditions. To date, genome-wide identification of MAP4Ks in cotton has not been reported. In this study, 77 MAP4K genes were identified in four Gossypium species. Protein characteristics, gene structures, conserved motifs and gene expression analysis were carried out. Genome-wide or fragment duplication has played an important role in the expansion of the GhMAP4K. Promoter cis-acting elements and expression patterns indicated that GhMAP4Ks are related to plant hormones (ABA, MeJA, GA, IAA, SA) and various stresses (drought, hypothermia and wound). Overexpressing GhMAP4K13 in Arabidopsis showed higher stem length in response to drought and salt stress. The wilting degree in virus-induced GhMAP4K13 gene silenced plants was substantially greater than wild type plants under drought and salt stress. Transcriptomic analysis showed that most differentially expressed genes were involved in the MAPK signaling pathway, carbon metabolism and porphyrin metabolism. Additionally, transgenic Arabidopsis and VIGS cotton showed that GhMAP4K13 was positively responsive to drought and salt stresses. This study will play an important role in understanding the function of the MAP4K gene family in response to abiotic stress in cotton.

Mitogen-activated protein (MAP) kinase signalling pathway VmMkh1-VmMkk1-VmSpm1 regulates cell wall integrity in Valsamali

Apple Valsa canker disease, caused by Valsa mali Miyabe et Yamada, seriously endangers the healthy growth of apple trees. Mitogen-Activated Protein Kinase (MAPK) signaling pathway is an important pathway to transmit signals stimulated by environmental stress. In this study, we identify and functionally characterize MAPKKK VmMkh1, MAPKK VmMkk1 and MAPK VmSpm1. VmMkh1 and VmMkk1 positively regulate the phosphorylation of VmSpm1. The radial growth rate of the VmSpm1 deletion mutant was reduced by approximately 31 %. There was no significant difference in growth rate between the VmMkh1 and VmMkk1 mutant and the wild-type. VmMkh1 hyphe branches into a curved shape. The VmMkh1, VmMkk1, and VmSpm1 deletion mutant produced fewer conidia than the wild-type strain at 20 days post inoculation. Moreover, the VmMkh1, VmMkk1, and VmSpm1 deletion mutant slows conidial germination. The hyphal growth of VmMkh1, VmMkk1, and VmSpm1 deletion mutants are significantly inhibited on media containing NaCl, KCl, sorbitol (high osmotic stresses). The hyphal growth of VmMkh1, VmMkk1, and VmSpm1 deletion mutants are significantly inhibited on media containing Congo red, CFW, SDS, and Lysing encymes (Cell wall stress agents). A looser distribution of spacers in VmMkh1, VmMkk1, and VmSpm1 deletion mutants compared with the wild-type strain. The size of lesions on apple fruits and branches inoculated with VmSpm1 deletion mutant showed a reduction of approximately 46 % and 43 %, respectively, after 9 dpi. Overall, our findings demonstrate that VmMkh1, VmMkk1, and VmSpm1 are involved in regulating the growth and development, colony surface hydrophobicity, osmotic stress, cell wall integrity maintenance, carbon and nitrogen source utilization, septa formation, and pathogenicity of Valsa mali.

Saroglitazar ameliorates 5- Fluorouracil-induced hepatorenal damage in rats

RATIONALE

Hepatotoxicity and nephrotoxicity are significant adverse effects caused in cancer patients treated with 5-Flurouracil (5-FU), a pyrimidine analogue anti-metabolite anticancer drug. The purpose of this research was to evaluate the impact of PPAR α/γ agonist (Saroglitazar; SARO) on 5-FU-induced hepatorenal damage in rats.

METHODS

Male rats were randomly assigned to four groups: control, 5-FU, 5-FU + SARO (2 mg/kg), and 5-FU + SARO (4 mg/kg). Rats received 75 mg/kg 5-FU intraperitoneally once weekly for three weeks. Saroglitazar (2 and 4 mg/kg/day) was orally supplied by oral syringe for three consecutive weeks. On day 22, rats were euthanized and their livers and kidneys were subjected to morphological, biochemical, histological, and immunohistochemical analysis.

RESULTS

Saroglitazar treatment significantly decreased serum liver and kidney function biomarkers. In addition, it successfully modulated liver and kidney levels of inflammatory mediators and markers (NF-κB P65, TNF-α, cleaved caspase-1, IL-1β and p-p38 MAPK) and oxidative stress-related parameters (MDA, GSH, SOD, Keap1, Nrf-2 and HO-1) in a dose dependent manner. Furthermore, SARO could attenuate 5-FU-induced activation of cleaved caspase-3 as well as improved histopathological examination of both liver and kidney tissues.

SIGNIFICANCE

Saroglitazar may be a viable therapy option for 5-FU toxicity as it halts the interaction network of NF-kB and Nrf2 signaling pathways and apoptosis.

Chemical-sensitized MITOGEN-ACTIVATED PROTEIN KINASE 4 provides insights into its functions in plant growth and immunity

Two mitogen-activated protein kinase (MAPK) cascades with MPK4 and MPK3/MPK6 as the bottommost kinases are key to plant growth/development and immune signaling. Disruption of the MPK4 cascade leads to severe dwarfism and autoimmunity, complicating the study of MPK4 in plant growth/development and immunity. In this study, we successfully rescued the Arabidopsis (Arabidopsis thaliana) mpk4 mutant using a chemical-sensitized MPK4 variant, MPK4YG, creating a conditional activity-null mpk4 mutant named MPK4SR (genotype: PMPK4:MPK4YG mpk4) that could be used to examine the functions of MPK4 in plant growth/development and immunity. We discovered that the duration of the loss of MPK4 activity is important to plant immune responses. Short-term loss of MPK4 activity did not impact flg22-induced ROS burst or resistance against Pseudomonas syringae (Pst). Enhanced Pst resistance was only observed in the MPK4SR plants with stunted growth following prolonged inhibition of MPK4 activity. Transcriptome analyses in plants with short-term loss of MPK4 activity revealed a vital role of MPK4 in regulating several housekeeping processes, including mitosis, transcription initiation, and cell wall macromolecule catabolism. Furthermore, the constitutive weak activation of MPK4GA in the MPK4CA plants (genotype: PMPK4:MPK4GA mpk4) led to early flowering and premature senescence, which was associated with its compromised resistance against Pst. These findings suggest that MPK4 plays important roles in plant growth and development and in maintaining the delicate balance between growth/development and immune adaptation in plants.

Quantitative analysis of septin Cdc10 & Cdc3-associated proteome during stress response in the fungal pathogen Cryptococcus neoformans

Cryptococcus neoformans is a pathogenic basidiomycetous yeast that primarily infects immunocompromised individuals. Fatal outcome of cryptococcosis depends on the ability of C. neoformans to sense and adapt to 37°C. A complex of conserved filament forming GTPases, called septins, composed of Cdc3, Cdc10, Cdc11, and Cdc12, assembles at the mother-bud neck in C. neoformans. Septins Cdc3 and Cdc12 are essential for proliferation of C. neoformans at 37°C and for virulence in the Galleria mellonella model of infection, presumably due to their requirement for septin complex formation, and the involvement in cytokinesis. However, how exactly Cdc3, and Cdc12 contribute to C. neoformans growth at 37°C remains unknown. Based on studies investigating roles of septins in Saccharomyces cerevisiae, septin complex at the mother-bud neck of C. neoformans is predicted to interact with proteins involved in cell cycle control, morphogenesis, and cytokinesis, but the septin-associated proteome in C. neoformans has not been investigated. Here, we utilized tandem mass spectrometry to define C. neoformans proteins that associate with either Cdc3 or Cdc10 at ∼25°C or after the shift to 37°C. Our findings unveil a diverse array of septin-associated proteins, highlighting potential roles of septins in cell division, and stress response. Two proteins, identified as associated with both Cdc3 and Cdc10, the actin-binding protein profilin, which was detected at both temperatures, and ATP-binding multi-drug transporter Afr1, which was detected exclusively at 37°C, were further confirmed by co-immunoprecipitation. We also confirmed that association of Cdc3 with Afr1 was enhanced at 37°C. Upon shift to 37°C, septins Cdc3 and Cdc10 exhibited altered localization and Cdc3 partially co-localized with Afr1. In addition, we also investigated changes to levels of individual C. neoformans proteins upon shift from ∼25 to 37°C in exponentially grown culture and when cells entered stationary phase at ∼25°C. Our study reveals changes to C. neoformans proteome associated with heat and nutrient deprivation stresses and provides a landscape of septin-associated C. neoformans proteome, which will facilitate elucidating the biology of septins and mechanisms of stress response in this fungal pathogen.

Specific SOX10 enhancer elements modulate phenotype plasticity and drug resistance in melanoma

Recent studies indicate that the development of drug resistance and increased invasiveness in melanoma is largely driven by transcriptional plasticity rather than canonical coding mutations. Understanding the mechanisms behind cell identity shifts in oncogenic transformation and cancer progression is crucial for advancing our understanding of melanoma and other aggressive cancers. While distinct melanoma phenotypic states have been well characterized, the processes and transcriptional controls that enable cells to shift between these states remain largely unknown. In this study, we initially leverage the well-established zebrafish melanoma model as a high-throughput system to dissect and analyze transcriptional control elements that are hijacked by melanoma. We identify key characteristics of these elements, making them translatable to human enhancer identification despite the lack of direct sequence conservation. Building on our identification of a zebrafish sox10 enhancer necessary for melanoma initiation, we extend these findings to human melanoma, identifying two human upstream enhancer elements that are critical for full SOX10 expression. Stable biallelic deletion of these enhancers using CRISPR-Cas9 induces a distinct phenotype shift across multiple human melanoma cell lines from a melanocytic phenotype towards an undifferentiated phenotype and is also characterized by an increase in drug resistance that mirrors clinical data including an upregulation of NTRK1, a tyrosine kinase, and potential therapeutic target. These results provide new insights into the transcriptional regulation of SOX10 in human melanoma and underscore the role of individual enhancer elements and potentially NTRK1 in driving melanoma phenotype plasticity and drug resistance. Our work lays the groundwork for future gene-based and combination kinase-inhibitor therapies targeting SOX10 regulation and NTRK1 as a potential avenue for enhancing the efficacy of current melanoma treatments.

The crucial role of NR2A mediating the activation of satellite glial cells in the trigeminal ganglion contributes to orofacial inflammatory pain during TMJ inflammation

Temporomandibular joint inflammatory diseases are a significant subtype of temporomandibular disorders (TMD) characterized by inflammatory pain in the orofacial area. The N-methyl-D-aspartate receptor (NMDAR), specifically the NR2A subtype, was crucial in neuropathic pain. However, the exact role of NR2A in inflammatory pain in the TMJ and the molecular and cellular mechanisms mediating peripheral sensitization in the trigeminal ganglion (TG) remain unclear. This study utilized male and female mice to induce the TMJOA model by injecting Complete Freund's adjuvant (CFA) into the TMJ and achieve conditional knockout (CKO) of NR2A in the TG using Cre/Loxp technology. The Von-Frey filament test results showed that CFA-induced orofacial pain with reduced mechanical withdrawal threshold (MWT), which was not developed in NR2A CKO mice. Additionally, the up-regulation of interleukin (IL)-1β, IL-6, and nerve growth factor (NGF) in the TG induced by CFA did not occur by NR2A deficiency. In vitro, NMDA activated satellite glial cells (SGCs) with high expression of glial fibrillary acidic protein (GFAP), and both NMDA and LPS led to increased IL-1β, IL-6, and NGF in SGCs. NR2A deficiency reduced these stimulating effects of NMDA and LPS. The regulation of IL-1β involved the p38, Protein Kinase A (PKA), and Protein Kinase C (PKC) pathways, while IL-6 signaling relied on PKA and PKC pathways. NGF regulation was primarily through the p38 pathway. This study highlighted NR2A's crucial role in the TG peripheral sensitization during TMJ inflammation by mediating ILs and NGF, suggesting potential targets for orofacial inflammatory pain management.

Mining of Candidate Genes and Developing Molecular Markers Associated with Pokkah Boeng Resistance in Sugarcane (Saccharum spp.)

Sugarcane Pokkah Boeng (PB), a fungal disease caused by Fusarium spp., poses a significant threat to sugar industries globally. Breeding sugarcane varieties resistant to PB has become a priority, and the mining of PB resistance genes and the development of molecular markers provide a solid foundation for this purpose. This work comprehensively analyzes the genetic components of sugarcane's resistance to PB using transcriptome sequencing. A segregating population was created by crossing the susceptible parent ROC25 with the resistant parent Yunzhe89-7, which is a traditional cultivar known for its PB resistance. Transcriptome analysis uncovered many differentially expressed genes (DEGs) associated with PB resistance. Utilizing weighted gene co-expression network analysis (WGCNA), we identified gene modules closely related to disease phenotypes. We annotated their functions with bioinformatics tools, particularly focusing on genes enriched in the plant immune response's MAPK signaling pathway and ABC transporter synthesis pathways. In addition, by integrating whole-genome resequencing data of parental lines and transcriptome data of progeny, we identified a series of putative molecular markers that potentially effectively differentiate between highly resistant and susceptible materials. Our study provides crucial genetic resources and molecular methodologies that are essential for the advancement of sugarcane varieties with improved resistance to PB. These innovations are expected to accelerate the breeding process greatly.

Microglia in morphine tolerance: cellular and molecular mechanisms and therapeutic potential

Morphine has a crucial role in treating both moderate to severe pain and chronic pain. However, prolonged administration of morphine can lead to tolerance of analgesia, resulting in increased doses and poor treatment of pain. Many patients, such as those with terminal cancer, require high doses of morphine for long periods. Addressing morphine tolerance can help this group of patients to escape pain, and the mechanisms behind this need to be investigated. Microglia are the key cells involved in morphine tolerance and chronic morphine administration leads to microglia activation, which in turn leads to activation of internal microglia signalling pathways and protein transcription, ultimately leading to the release of inflammatory factors. Inhibiting the activation of microglia internal signalling pathways can reduce morphine tolerance. However, the exact mechanism of how morphine acts on microglia and ultimately leads to tolerance is unknown. This article discusses the mechanisms of morphine induced microglia activation, reviews the signalling pathways within microglia and the associated therapeutic targets and possible drugs, and provides possible directions for clinical prevention or retardation of morphine induced analgesic tolerance.

Genet identity and season drive gene expression in outplanted Acropora palmata at different reef sites

Coral reefs are experiencing decreases in coral cover due to anthropogenic influences. Coral restoration is addressing this decline by outplanting large volumes of corals onto reef systems. Understanding how outplanted corals react at a transcriptomic level to different outplant locations over time is important, as it will highlight how habitat affects the coral host and influences physiological measures. In this study, the transcriptomic dynamics of four genets of outplanted Acropora palmata were assessed over a year at three reef sites in the Florida Keys. Genet identity was more important than time of sampling or outplant site, with differing levels of baseline immune and protein production the key drivers. Once accounting for genet, enriched growth processes were identified in the winter, and increased survival and immune expression were found in the summer. The effect of the reef site was small, with hypothesized differences in autotrophic versus heterotrophic dependent on outplant depth. We hypothesize that genotype identity is an important consideration for reef restoration, as differing baseline gene expression could play a role in survivorship and growth. Additionally, outplanting during cooler winter months may be beneficial due to higher expression of growth processes, allowing establishment of outplants on the reef system.

Whole genome resequencing revealed genomic variants and functional pathways related to adaptation in Indian yak populations

The present study aims to identify genomic variants through a whole genome sequencing (WGS) approach and uncover biological pathways associated with adaptation and fitness in Indian yak populations. A total of 30 samples (10 from each population) were included from Arunachali, Himachali and Ladakhi yak populations. WGS analysis revealed a total of 32171644, 27260825, and 32632460 SNPs and 4865254, 4429941, and 4847513 Indels in the Arunachali, Himachali, and Ladakhi yaks, respectively. Genes such as RYR2, SYNE2, BOLA, HF1, and the novel transcript ENSBGRG00000011079 were found to have the maximum number of high impact variants in all three yak populations, and might play a major role in local adaptation. Functional enrichment analysis of genes harboring high impact SNPs revealed overrepresented pathways related to response to stress, immune system regulation, and high-altitude adaptation. This study provides comprehensive information about genomic variants and their annotation in Indian yak populations, thus would serve as a data resource for researchers working on the yaks. Furthermore, it could be well exploited for better yak conservation strategies by estimating population genetics parameters viz., effective population size, inbreeding, and observed and expected heterozygosity.

Cellular and Molecular Mechanisms of Hypertrophy of Ligamentum Flavum

Hypertrophy of the ligamentum flavum (HLF) is a common contributor to lumbar spinal stenosis (LSS). Fibrosis is a core pathological factor of HLF resulting in degenerative LSS and associated low back pain. Although progress has been made in HLF research, the specific molecular mechanisms that promote HLF remain to be defined. The molecular factors involved in the onset of HLF include increases in inflammatory cytokines such as transforming growth factor (TGF)-β, matrix metalloproteinases, and pro-fibrotic growth factors. In this review, we discuss the current understanding of the mechanisms involved in HLF with a particular emphasis on aging and mechanical stress. We also discuss in detail how several pathomechanisms such as fibrosis, proliferation and apoptosis, macrophage infiltration, and autophagy, in addition to several molecular pathways involving TGF-β1, mitogen-activated protein kinase (MAPKs), and nuclear factor-κB (NF-κB) signaling, PI3K/AKT signaling, Wnt signaling, micro-RNAs, extracellular matrix proteins, reactive oxygen species (ROS), etc. are involved in fibrosis leading to HLF. We also present a summary of the current advancements in preclinical animal models for HLF research. In addition, we update the current and potential therapeutic targets/agents against HLF. An improved understanding of the molecular processes behind HLF and a novel animal model are key to developing effective LSS prevention and treatment strategies.

Phosphorylation of mammalian cytosolic and mitochondrial malate dehydrogenase: insights into regulation

Malate dehydrogenase (MDH) is a key enzyme in mammalian metabolic pathways in cytosolic and mitochondrial compartments. Regulation of MDH through phosphorylation remains an underexplored area. In this review we consolidate evidence supporting the potential role of phosphorylation in modulating the function of mammalian MDH. Parallels are drawn with the phosphorylation of lactate dehydrogenase, a homologous enzyme, to reveal its regulatory significance and to suggest a similar regulatory strategy for MDH. Comprehensive mining of phosphorylation databases, provides substantial experimental (primarily mass spectrometry) evidence of MDH phosphorylation in mammalian cells. Experimentally identified phosphorylation sites are overlaid with MDH's functional domains, offering perspective on how these modifications could influence enzyme activity. Preliminary results are presented from phosphomimetic mutations (serine/threonine residues changed to aspartate) generated in recombinant MDH proteins serving as a proof of concept for the regulatory impact of phosphorylation. We also examine and highlight several approaches to probe the structural and cellular impact of phosphorylation. This review highlights the need to explore the dynamic nature of MDH phosphorylation and calls for identifying the responsible kinases and the physiological conditions underpinning this modification. The synthesis of current evidence and experimental data aims to provide insights for future research on understanding MDH regulation, offering new avenues for therapeutic interventions in metabolic disorders and cancer.

Characterization of MKK family genes and their responses to temperature stress and Vibrio parahaemolyticus infection in noble scallop Chlamys nobilis

Mitogen-activated protein kinase kinase (MKK), the key element of the Mitogen-activated protein kinase (MAPK) signaling pathway, is crucial for the immune response to adverse environments in aquatic animals. Nevertheless, there is limited information regarding the role of the MKK gene family in mollusks. In our study, genome data and transcriptome were used to identify four MKK genes (CnMKK4, CnMKK5, CnMKK6, and CnMKK7) in the noble scallop. The result of the gene structure, motif analysis, and phylogenetic tree revealed that MKK genes are relatively conserved in bivalves. Moreover, four CnMKK genes were significantly highly expressed in immune-related tissues, suggesting that CnMKKs may related to bivalve immunity. Furthermore, CnMKK6 and CgMKK4 were significantly differentially expressed (P < 0.05) under 24 h of temperature stress, and all CnMKKs were significantly differentially expressed (P < 0.05) under 24 h of Vibrio parahaemolyticus infection. These results showed that the CnMKKs may have a significant impact under biotic and abiotic stresses. In conclusion, the result of the CnMKKs provides valuable insights into comprehending the function of MKK genes in mollusks.

The construction of a prognostic model by apoptosis-related genes to predict survival, immune landscape, and medication in cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive and invasive malignant tumor of the bile duct, with a poor prognosis and a high mortality rate. Currently, there is a lack of effective targeted treatment methods and reliable biomarkers for prognosis.

METHODS

We downloaded RNA-seq and clinical data of CCA from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases as training and test sets. The apoptosis-related genes were obtained from the Molecular Signatures Database (MsigDB) database. We used univariate/multivariate Cox regression and Lasso regression analyses to construct a riskscore prognostic model. Based on the median riskscore, we clustered the patients into high-risk (HR) and low-risk (LR) groups. We carried out Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of differentially expressed genes (DEGs) in HR and LR groups. The single sample gene set enrichment analysis (ssGSEA) was employed to analyze the immune infiltration of the HR and LR groups. The CellMiner database was utilized to predict drugs and perform molecular docking on drugs and target proteins.

RESULTS

We identified 8 genes with prognostic significance to construct a prognostic model. Results of GO and KEGG demonstrated that DEGs were mainly enriched in biological functions such as fatty acid metabolic processes and pathways such as the cAMP signaling pathway. Results of ssGSEA uncovered that immune cells such as DCs and Macrophages in the HR group, as well as immune functions such as Check-point and Parainflammation, were considerably higher than those in the LR group. Drug sensitivity prediction and results of molecular docking revealed that Rigosertib targeted the prognostic genes MAP3K1. HYPOTHEMYCIN and AMG900 effectively targeted JUN.

CONCLUSION

Our project suggested that the prognostic model with apoptotic features can effectively predict prognosis in CCA patients, proffering prognostic biomarkers and potential therapeutic targets for CCA patients.

Understanding the Genetic Landscape of Gestational Diabetes: Insights into the Causes and Consequences of Elevated Glucose Levels in Pregnancy

Background/Objectives: During pregnancy, physiological changes in maternal circulating glucose levels and its metabolism are essential to meet maternal and fetal energy demands. Major changes in glucose metabolism occur throughout pregnancy and consist of higher insulin resistance and a compensatory increase in insulin secretion to maintain glucose homeostasis. For some women, this change is insufficient to maintain normoglycemia, leading to gestational diabetes mellitus (GDM), a condition characterized by maternal glucose intolerance and hyperglycaemia first diagnosed during the second or third trimester of pregnancy. GDM is diagnosed in approximately 14.0% of pregnancies globally, and it is often associated with short- and long-term adverse health outcomes in both mothers and offspring. Although recent studies have highlighted the role of genetic determinants in the development of GDM, research in this area is still lacking, hindering the development of prevention and treatment strategies. Methods: In this paper, we review recent advances in the understanding of genetic determinants of GDM and glycaemic traits during pregnancy. Results/Conclusions: Our review highlights the need for further collaborative efforts as well as larger and more diverse genotyped pregnancy cohorts to deepen our understanding of the genetic aetiology of GDM, address research gaps, and further improve diagnostic and treatment strategies.

GhMPK9-GhRAF39_1-GhWRKY40a Regulates the GhERF1b- and GhABF2-Mediated Pathways to Increase Cotton Disease Resistance

Mitogen-activated protein kinase (MAPK) cascade is the center of plant signal transduction system that amplify immune signals into cellular responses by phosphorylating diverse substrates. The MAPK cascade consisting of MAPK kinase kinases (MAPKKKs), MAPK kinases (MAPKKs), and MAPKs is well characterized in plants, in which Raf-like kinases are generally regarded as MAPKKKs. However, it is rarely reported that Raf-like MAPKKKs function as middle regulators to link MAPK and its downstream transcription factors in plant immunity. Verticillium wilt, caused by the soil-borne vascular fungus Verticillium dahliae, is a serious disease in many plants, including cotton. The previous studies showed that GhMPK9 (a MAPK) is involved in the response to Verticillium wilt. Here, the Raf-like kinase GhRAF39_1 is reported as helper regulates the phosphorylation of WRKY transcription factor GhWRKY40a by GhMPK9. The phosphorylated GhWRKY40a can further activate the transcription of GhERF1b to up-regulate defense-related genes while inhibit the transcription of GhABF2 to regulate the stomatal opening, thus improving the resistance to Verticillium wilt in cotton. This study reveals a new signaling module of GhMPK9-GhRAF39_1-GhWRKY40a to regulate GhERF1b- and GhABF2-mediated defense responses, which triggers plant defense against Verticillium wilt.

Cytoplasmic tail of transmembrane dscam controls antibacterial responses by regulating cell proliferation-related genes in hemocytes of Chinese mitten crab (Eriocheir sinensis)

In arthropods, the involvement of Dscam (Down syndrome cell adhesion molecule) in innate immunity has been extensively demonstrated. Its cytoplasmic tail contains multiple conserved functional sites, which indicates its involvement in different intracellular signaling pathways. In this study, we focused on the role of the cytoplasmic tail of Dscam in the Chinese mitten crab (Eriocheir sinensis) immune defense. In the group with cytoplasmic tail knockdown (the site was located on constant exons 37 and 38), 3885 differentially expressed genes (DEGs) were identified. The DEGs were enriched in small molecule binding, protein-containing complex binding, and immunity-related pathways. The expression of selected genes were validated using quantitative real-time reverse transcription PCR. We identified key Cell cycle, Janus kinase (JAK)-signal transducer, activator of transcription (STAT) and mitogen-activated protein kinase (MAPK) signaling pathway genes, the results indicated that the cytoplasmic tail of Dscam controls antibacterial responses by regulating cell proliferation-related genes in hemocytes.

Critical role of endoplasmic reticulum stress on bisphenol A-induced cytotoxicity in human keratinocyte HaCaT cells

Bisphenol A (BPA) is widely used in plastic and paper products, and its exposure can occur through skin contact or oral ingestion. The hazardous effects of BPA absorbed through the skin may be more severe; however, few studies have investigated the skin toxicity of BPA. This study investigated the effects of BPA on human epidermal keratinocyte cell lines, which is relevant for skin exposure. BPA treatment reduced cell viability in a time- and concentration-dependent manner and elevated oxidative and endoplasmic reticulum (ER) stress. N-acetylcysteine (NAC), an oxidative stress inhibitor, reduced BPA-induced reactive oxygen species (ROS) levels. However, only 10% of the decreased cell viability was restored at the highest NAC concentration. Treatment with tauroursodeoxycholic acid (TUDCA), which is an ER stress inhibitor, effectively countered the increase in ER stress-related proteins induced by BPA. Moreover, TUDCA treatment led to a reduction in oxidative stress, as demonstrated by the decrease in ROS levels, maintenance of mitochondrial membrane potential, and modulation of stress signaling proteins. Consequently, TUDCA significantly improved BPA-induced cytotoxicity in a concentration-dependent manner. Notably, combined treatment using TUDCA and NAC further reduced the BPA-induced ROS levels; however, no significant difference in cell viability was observed compared with that for TUDCA treatment alone. These findings indicated that the oxidative stress observed following BPA exposure was exacerbated by ER stress. Moreover, the principal factor driving BPA-induced cytotoxicity was indeed ER stress, which has potential implications for developing therapeutic strategies for diseases associated with similar stress responses.

Mitochondrial microRNA profiles are altered in thirteen-lined ground squirrels (Ictidomys tridecemlineatus) during hibernation

Thirteen-lined ground squirrels (TLGSs) are obligate hibernators that cycle between torpor (low metabolic rate and body temperature) and interbout euthermia (IBE; typical euthermic body temperature and metabolism) from late autumn to spring. Many physiological changes occur throughout hibernation, including a reduction in liver mitochondrial metabolism during torpor, which is reversed during arousal to interbout euthermia. Nuclear-encoded microRNA (miRNA, small posttranscriptional regulator molecules) differ in abundance throughout TLGS hibernation and have been shown to regulate mitochondrial gene expression in mammalian cell culture (where they are referred to as mitomiRs). This study characterized differences in mitomiR profiles from TLGS liver mitochondria isolated during summer, torpor, and IBE, and predicted their mitochondrial targets. Using small RNA sequencing, differentially abundant mitomiRs were identified between hibernation states, and using quantitative PCR analysis, we quantified the expression of predicted mitochondrial mRNA targets. Most differences in mitomiR abundances were seasonal (i.e., between summer and winter) with only one mitomiR differentially abundant between IBE and torpor. Multiple factor analysis (MFA) revealed three clusters divided by hibernation states, where clustering was predominantly driven by mitomiR abundances. Nine of these differentially abundant mitomiRs had predicted mitochondrial RNA targets, including subunits of electron transfer system complexes I and IV, 12S rRNA, and two tRNAs. Overall, mitomiRs were predicted to suppress the expression of their mitochondrial targets and may have some involvement in regulating protein translation in mitochondria. This study found differences in mitomiR abundances between seasons and hibernation states of TLGS and suggests potential mechanisms for regulating the mitochondrial electron transfer system.NEW & NOTEWORTHY During the hibernation season, thirteen-lined ground squirrels periodically increase metabolism remarkably between torpor and interbout euthermia (IBE). This process involves rapid reactivation of mitochondrial respiration. We predicted that mitochondrial microRNA (mitomiRs) might be altered during this response. We found that the abundance of 38 liver mitomiRs differs based on hibernation state (summer, IBE, and torpor). Small RNA sequencing identified mitomiR profiles, including some mitomiRs that are predicted to bind to mitochondrial RNAs.

Contribution of inwardly rectifying potassium channel 4.1 in orofacial neuropathic pain: Regulation of pannexin 3 via the reactive oxygen species-activated P38 MAPK signal pathway

The involvement of inwardly rectifying potassium channel 4.1 (Kir4.1) in neuropathic pain has been established. However, there is limited understanding of the downstream mechanism through which Kir4.1 contributes to orofacial neuropathic pain. The objective of this study was to examine the regulation of Kir4.1 on the expression of pannexin 3 (Panx3) in the trigeminal ganglion (TG) and the underlying mechanism in the context of orofacial neuropathic pain caused by chronic constriction injury of the infraorbital nerve (CCI-ION). The study observed a significant increase in Panx3 expression in the TG of mice with CCI-ION. Inhibition of Panx3 in the TG of CCI-ION mice resulted in alleviation of orofacial mechanical allodynia. Furthermore, conditional knockdown (CKD) of Kir4.1 in the TG of both male and female mice led to mechanical allodynia and upregulation of Panx3 expression. Conversely, overexpression of Kir4.1 decreased Panx3 levels in the TG and relieved mechanical allodynia in CCI-ION mice. In addition, silencing Kir4.1 in satellite glial cells (SGCs) decreased Panx3 expression and increased the phosphorylation of P38 MAPK. Moreover, silencing Kir4.1 in SGCs increased the levels of reactive oxygen species (ROS). The elevated phosphorylation of P38 MAPK resulting from Kir4.1 silencing was inhibited by using a superoxide scavenger known as the tempol. Silencing Panx3 in the TG in vivo attenuated the mechanical allodynia caused by Kir4.1 CKD. In conclusion, these findings suggest that the reduction of Kir4.1 promotes the expression of Panx3 by activating the ROS-P38 MAPK signalling pathway, thus contributing to the development of orofacial neuropathic pain.

Advances in the anti-tumor mechanisms of saikosaponin D

Saikosaponin D, a saponin compound, is extracted from Bupleurum and is a principal active component of the plant. It boasts a variety of pharmacologic effects including anti-inflammatory, antioxidant, immunomodulatory, metabolic, and anti-tumor properties, drawing significant attention in anti-tumor research in recent years. Research indicates that saikosaponin D inhibits the proliferation of numerous tumor cells, curbing the progression of cancers such as liver, pancreatic, lung, glioma, ovarian, thyroid, stomach, and breast cancer. Its anti-tumor mechanisms largely involve inhibiting tumor cell proliferation, promoting tumor cell apoptosis, thwarting tumor-cell invasion, and modulating tumor cell autophagy. Moreover, saikosaponin D enhances the sensitivity to anti-tumor drugs and augments body immunity. Given its multi-faceted anti-tumor roles, saikosaponin D offers promising potential in anti-tumor therapy. This paper reviews recent studies on its anti-tumor effects, aiming to furnish new theoretical insights for clinical cancer treatments.

Post-Translational Modification of WRKY Transcription Factors

Post-translational modifications (PTMs) of proteins are involved in numerous biological processes, including signal transduction, cell cycle regulation, growth and development, and stress responses. WRKY transcription factors (TFs) play significant roles in plant growth, development, and responses to both biotic and abiotic stresses, making them one of the largest and most vital TF families in plants. Recent studies have increasingly highlighted the importance of PTMs of WRKY TFs in various life processes. This review focuses on the recent advancements in understanding the phosphorylation and ubiquitination of WRKY TFs, particularly their roles in resistance to biotic and abiotic stresses and in plant growth and development. Future research directions and prospects in this field are also discussed.

Targeting the multifaceted BRAF in cancer: New directions

Activating mutations in the mitogen-activated protein kinase (MAPK) pathway represent driver alterations governing tumorigenesis, metastasis, and therapy resistance. MAPK activation predominantly occurs through genomic alterations in RAS and BRAF. BRAF is an effector kinase that functions downstream of RAS and propagates this oncogenic activity through MEK and ERK. Across cancers, BRAF alterations include gain-of-function mutations, copy-number alterations, and structural rearrangements. In cancer patients, BRAF-targeting precision therapeutics are effective against Class I BRAF alterations (p.V600 hotspot mutations) in tumors such as melanomas, thyroid cancers, and colorectal cancers. However, numerous non-Class I BRAF inhibitors are also in development and have been explored in some cancers. Here we discuss the diverse forms of BRAF alterations found in human cancers and the strategies to inhibit them in patients harboring cancers of distinct origins.

The absence of the ribosomal protein Rpl2702 elicits the MAPK-mTOR signaling to modulate mitochondrial morphology and functions

Ribosomes mediate protein synthesis, which is one of the most energy-demanding activities within the cell, and mitochondria are one of the main sources generating energy. How mitochondrial morphology and functions are adjusted to cope with ribosomal defects, which can impair protein synthesis and affect cell viability, is poorly understood. Here, we used the fission yeast Schizosaccharomyces Pombe as a model organism to investigate the interplay between ribosome and mitochondria. We found that a ribosomal insult, caused by the absence of Rpl2702, activates a signaling pathway involving Sty1/MAPK and mTOR to modulate mitochondrial morphology and functions. Specifically, we demonstrated that Sty1/MAPK induces mitochondrial fragmentation in a mTOR-independent manner while both Sty1/MAPK and mTOR increases the levels of mitochondrial membrane potential and mitochondrial reactive oxygen species (mROS). Moreover, we demonstrated that Sty1/MAPK acts upstream of Tor1/TORC2 and Tor1/TORC2 and is required to activate Tor2/TORC1. The enhancements of mitochondrial membrane potential and mROS function to promote proliferation of cells bearing ribosomal defects. Hence, our study reveals a previously uncharacterized Sty1/MAPK-mTOR signaling axis that regulates mitochondrial morphology and functions in response to ribosomal insults and provides new insights into the molecular and physiological adaptations of cells to impaired protein synthesis.

Arrestins: A Small Family of Multi-Functional Proteins

The first member of the arrestin family, visual arrestin-1, was discovered in the late 1970s. Later, the other three mammalian subtypes were identified and cloned. The first described function was regulation of G protein-coupled receptor (GPCR) signaling: arrestins bind active phosphorylated GPCRs, blocking their coupling to G proteins. It was later discovered that receptor-bound and free arrestins interact with numerous proteins, regulating GPCR trafficking and various signaling pathways, including those that determine cell fate. Arrestins have no enzymatic activity; they function by organizing multi-protein complexes and localizing their interaction partners to particular cellular compartments. Today we understand the molecular mechanism of arrestin interactions with GPCRs better than the mechanisms underlying other functions. However, even limited knowledge enabled the construction of signaling-biased arrestin mutants and extraction of biologically active monofunctional peptides from these multifunctional proteins. Manipulation of cellular signaling with arrestin-based tools has research and likely therapeutic potential: re-engineered proteins and their parts can produce effects that conventional small-molecule drugs cannot.

The effect of cannabinoid type 2 receptor agonist on morphine tolerance

Pain highly impacts the quality of life of patients. Morphine is used for pain treatment; however, its side effects, especially morphine tolerance, limit its use in the clinic. The problem of morphine tolerance has plagued health workers and patients for years. Unfortunately, the exact mechanism of morphine tolerance has not been fully clarified. The mechanisms of morphine tolerance that are currently being studied may include μ-opioid receptor (MOR) desensitization and internalization, mitogen-activated protein kinase (MAPK) pathway activation and crosstalk, the effects of microglia and the increase in inflammatory factors. Morphine tolerance can be alleviated by improving the pathophysiological changes that lead to morphine tolerance. Previous studies have shown that a cannabinoid type 2 (CB2) receptor agonist could attenuate morphine tolerance in a variety of animal models. Many studies have shown an interaction between the cannabinoid system and the opioid system. The CB2 receptor may modulate the effect of morphine through a pathway that is common to the MOR, since both receptors are G protein-coupled receptors (GPCRs). This study introduces the potential mechanism of morphine tolerance and the effect of CB2 receptor agonists on reducing morphine tolerance, which can provide new ideas for researchers studying morphine and provide beneficial effects for patients suffering from morphine tolerance.

OsMAPK6 phosphorylation and CLG1 ubiquitylation of GW6a non-additively enhance rice grain size through stabilization of the substrate

The chromatin modifier GRAIN WEIGHT 6a (GW6a) enhances rice grain size and yield. However, little is known about its gene network determining grain size. Here, we report that MITOGEN-ACTIVED PROTEIN KINASE 6 (OsMAPK6) and E3 ligase CHANG LI GENG 1 (CLG1) interact with and target GW6a for phosphorylation and ubiquitylation, respectively. Unexpectedly, however, in vitro and in vivo assays reveal that both of the two post-translational modifications stabilize GW6a. Furthermore, we uncover two major GW6a phosphorylation sites (serine142 and threonine186) targeted by OsMAPK6 serving an important role in modulating grain size. In addition, our genetic and molecular results suggest that the OsMAPK6-GW6a and CLG1-GW6a axes are crucial and operate in a non-additive manner to control grain size. Overall, our findings identify a previously unknown mechanism by which phosphorylation and ubiquitylation non-additively stabilize GW6a to enhance grain size, and reveal correlations and interactions of these posttranslational modifications during rice grain development.

Bone and Extracellular Signal-Related Kinase 5 (ERK5)

Bones are vital for anchoring muscles, tendons, and ligaments, serving as a fundamental element of the human skeletal structure. However, our understanding of bone development mechanisms and the maintenance of bone homeostasis is still limited. Extracellular signal-related kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, plays a critical role in the pathogenesis and progression of various diseases, especially neoplasms. Recent studies have highlighted ERK5's significant role in both bone development and bone-associated pathologies. This review offers a detailed examination of the latest research on ERK5 in different tissues and diseases, with a particular focus on its implications for bone health. It also examines therapeutic strategies and future research avenues targeting ERK5.

Soybean MKK2 establishes intricate signalling pathways to regulate soybean response to cyst nematode infection

Mitogen-activated protein kinase (MPK) cascades play central signalling roles in plant immunity and stress response. The soybean orthologue of MPK kinase2 (GmMKK2) was recently identified as a potential signalling node whose expression is upregulated in the feeding site induced by soybean cyst nematode (SCN, Heterodera glycines). To investigate the role of GmMKK2 in soybean-SCN interactions, we overexpressed a catabolically inactive variant referred to as kinase-dead variant (KD-GmMKK2) using transgenic hairy roots. KD-GmMKK2 overexpression caused significant reduction in soybean susceptibility to SCN, while overexpression of the wild-type variant (WT-GmMKK2) exhibited no effect on susceptibility. Transcriptome analysis indicated that KD-GmMKK2 overexpressing plants are primed for SCN resistance via constitutive activation of defence signalling, particularly those related to chitin, respiratory burst, hydrogen peroxide and salicylic acid. Phosphoproteomic profiling of the WT-GmMKK2 and KD-GmMKK2 root samples upon SCN infection resulted in the identification of 391 potential targets of GmMKK2. These targets are involved in a broad range of biological processes, including defence signalling, vesicle fusion, chromatin remodelling and nuclear organization among others. Furthermore, GmMKK2 mediates phosphorylation of numerous transcriptional and translational regulators, pointing to the presence of signalling shortcuts besides the canonical MAPK cascades to initiate downstream signalling that eventually regulates gene expression and translation initiation. Finally, the functional requirement of specific phosphorylation sites for soybean response to SCN infection was validated by overexpressing phospho-mimic and phospho-dead variants of two differentially phosphorylated proteins SUN1 and IDD4. Together, our analyses identify GmMKK2 impacts on signalling modules that regulate soybean response to SCN infection.

Deoxycholic acid inhibits ASFV replication by inhibiting MAPK signaling pathway

African swine fever (ASF) is an acute, febrile, highly contagious infection of pigs caused by the African swine fever virus (ASFV). The purpose of this study is to understand the molecular mechanism of ASFV infection and evaluate the effect of DCA on MAPK pathway, so as to provide scientific basis for the development of new antiviral drugs. The transcriptome analysis found that ASFV infection up-regulated the IL-17 and MAPK signaling pathways to facilitate viral replication. Metabolome analysis showed that DCA levels were up-regulated after ASFV infection, and that exogenous DCA could inhibit activation of the MAPK pathway by ASFV infection and thus inhibit viral replication. Dual-luciferase reporter assays were used to screen the genes of ASFV and revealed that I73R could significantly up-regulate the transcription level of AP-1 transcription factor in the MAPK pathway. Confocal microscopy demonstrated that I73R could promote AP-1 entry into the nucleus, and that DCA could inhibit the I73R-mediated nuclear entry of AP-1, inhibiting MAPK pathway, and I73R interacts with AP-1. These results indicated that DCA can inhibit ASFV-mediated activation of the MAPK pathway, thus inhibiting ASFV replication. This study provides a theoretical basis for research on ASF pathogenesis and for antiviral drug development.

Photobiomodulation mitigates Bothrops jararacussu venom-induced damage in myoblast cells by enhancing myogenic factors and reducing cytokine production

BACKGROUND

Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are not yet fully understood. Herein, the effectiveness of photobiomodulation effects on regenerative response of C2C12 myoblast cells following exposure to Bothrops jararacussu venom (BjsuV), as well as the mechanisms involved was investigated.

METHODOLOGY/PRINCIPAL FINDINGS

C2C12 myoblast cells were exposed to BjsuV (12.5 μg/mL) and irradiated once for 10 seconds with laser light of 660 nm (14.08 mW; 0.04 cm2; 352 mW/cm2) or 780 nm (17.6 mW; 0.04 cm2; 440 mW/ cm2) to provide energy densities of 3.52 and 4.4 J/cm2, and total energies of 0.1408 and 0.176 J, respectively. Cell migration was assessed through a wound-healing assay. The expression of MAPK p38-α, NF-Кβ, Myf5, Pax-7, MyoD, and myogenin proteins were assessed by western blotting analysis. In addition, interleukin IL1-β, IL-6, TNF-alfa and IL-10 levels were measured in the supernatant by ELISA. The PBM applied to C2C12 cells exposed to BjsuV promoted cell migration, increase the expression of myogenic factors (Pax7, MyF5, MyoD and myogenin), reduced the levels of proinflammatory cytokines, IL1-β, IL-6, TNF-alfa, and increased the levels of anti-inflammatory cytokine IL-10. In addition, PBM downregulates the expression of NF-kB, and had no effect on p38 MAKP.

CONCLUSION/SIGNIFICANCE

These data demonstrated that protection of the muscle cell by PBM seems to be related to the increase of myogenic factors as well as the modulation of inflammatory mediators. PBM therapy may offer a new therapeutic strategy to address the local effects of snakebite envenoming by promoting muscle regeneration and reducing the inflammatory process.

Recent advances in understanding the role of two mitogen-activated protein kinase cascades in plant immunity

The mitogen-activated protein kinase (MAPK/MPK) cascade is an important intercellular signaling module that regulates plant growth, development, reproduction, and responses to biotic and abiotic stresses. A MAPK cascade usually consists of a MAPK kinase kinase (MAPKKK/MEKK), a MAPK kinase (MAPKK/MKK/MEK), and a MAPK. The well-characterized MAPK cascades in plant immunity to date are the MEKK1-MKK1/2-MPK4 cascade and the MAPKKK3/4/5-MKK4/5-MPK3/6 cascade. Recently, major breakthroughs have been made in understanding the molecular mechanisms associated with the regulation of immune signaling by both of these MAPK cascades. In this review, we highlight the most recent advances in understanding the role of both MAPK cascades in activating plant defense and in suppressing or fine-tuning immune signaling. We also discuss the molecular mechanisms by which plants stabilize and maintain the activation of MAPK cascades during immune signaling. Based on this review, we reveal the complexity and importance of the MEKK1-MKK1/2-MPK4 cascade and the MAPKKK3/4/5-MKK4/5-MPK3/6 cascade, which are tightly controlled by their interacting partners or substrates, in plant immunity.

Nanodrug-bacteria conjugates-mediated oncogenic collagen depletion enhances immune checkpoint blockade therapy against pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) cancer cells specifically produce abnormal oncogenic collagen to bind with integrin α3β1 receptor and activate the downstream focal adhesion kinase (FAK), protein kinase B (AKT), and mitogen-activated protein kinase (MAPK) signaling pathway. Collectively, this promotes immunosuppression and tumor proliferation and restricts the response rate of clinical cancer immunotherapies.

METHODS

Here, by leveraging the hypoxia tropism and excellent motility of the probiotic Escherichia coli strain Nissle 1917 (ECN), we developed nanodrug-bacteria conjugates to penetrate the extracellular matrix (ECM) and shuttle the surface-conjugated protein cages composed of collagenases and anti-programmed death-ligand 1 (PD-L1) antibodies to PDAC tumor parenchyma.

FINDINGS

We found the oncogenic collagen expression in human pancreatic cancer patients and demonstrated its interaction with integrin α3β1. We proved that reactive oxygen species (ROS) in the microenvironment of PDAC triggered collagenase release to degrade oncogenic collagen and block integrin α3β1-FAK signaling pathway, thus overcoming the immunosuppression and synergizing with anti-PD-L1 immunotherapy.

CONCLUSIONS

Collectively, our study highlights the significance of oncogenic collagen in PDAC immunotherapy, and consequently, we developed a therapeutic strategy that can deplete oncogenic collagen to synergize with immune checkpoint blockade for enhanced PDAC treatment efficacy.

FUNDING

This work was supported by the University of Wisconsin Carbone Cancer Center Research Collaborative and Pancreas Cancer Research Task Force, UWCCC Transdisciplinary Cancer Immunology-Immunotherapy Pilot Project, and the start-up package from the University of Wisconsin-Madison (to Q.H.).

Nanoquercetin and Extracellular Vesicles as Potential Anticancer Therapeutics in Hepatocellular Carcinoma

Despite world-class sophisticated technologies, robotics, artificial intelligence, and machine learning approaches, cancer-associated mortalities and morbidities have shown continuous increments posing a healthcare burden. Drug-based interventions were associated with systemic toxicities and several limitations. Natural bioactive compounds derived nanoformulations, especially nanoquercetin (nQ), are alternative options to overcome drug-associated limitations. Moreover, the EVs-based cargo targeted delivery of nQ can have enormous potential in treating hepatocellular carcinoma (HCC). EVs-based nQ delivery synergistically regulates and dysregulates several pathways, including NF-κB, p53, JAK/STAT, MAPK, Wnt/β-catenin, and PI3K/AKT, along with PBX3/ERK1/2/CDK2, and miRNAs intonation. Furthermore, discoveries on possible checkpoints of anticancer signaling pathways were studied, which might lead to the development of modified EVs infused with nQ for the development of innovative treatments for HCC. In this work, we abridged the control of such signaling systems using a synergetic strategy with EVs and nQ. The governing roles of extracellular vesicles controlling the expression of miRNAs were investigated, particularly in relation to HCC.

Traditional Chinese medicine in osteoporosis: from pathogenesis to potential activity

Osteoporosis characterized by decreased bone density and mass, is a systemic bone disease with the destruction of microstructure and increase in fragility. Osteoporosis is attributed to multiple causes, including aging, inflammation, diabetes mellitus, and other factors induced by the adverse effects of medications. Without treatment, osteoporosis will further progress and bring great trouble to human life. Due to the various causes, the treatment of osteoporosis is mainly aimed at improving bone metabolism, inhibiting bone resorption, and promoting bone formation. Although the currently approved drugs can reduce the risk of fragility fractures in individuals, a single drug has limitations in terms of safety and effectiveness. By contrast, traditional Chinese medicine (TCM), a characteristic discipline in China, including syndrome differentiation, Chinese medicine prescription, and active ingredients, shows unique advantages in the treatment of osteoporosis and has received attention all over the world. Therefore, this review summarized the pathogenic factors, pathogenesis, therapy limitations, and advantages of TCM, aiming at providing new ideas for the prevention and treatment of OP.

Early-Responsive Immunoregulation Therapy Improved Microenvironment for Bone Regeneration Via Engineered Extracellular Vesicles

Overactivated inflammatory reactions hinder the bone regeneration process. Timely transformation of microenvironment from pro-inflammatory to anti-inflammatory after acute immune response is favorable for osteogenesis. Macrophages play an important role in the immune response to inflammation. Therefore, this study adopts TIM3 high expression extracellular vesicles (EVs) with immunosuppressive function to reshape the early immune microenvironment of bone injury, mainly by targeting macrophages. These EVs can be phagocytosed by macrophages, thereby increasing the infiltration of TIM3-positive macrophages (TIM3+ macrophages) and M2 subtypes. The TIM3+ macrophage group has some characteristics of M2 macrophages and secretes cytokines, such as IL-10 and TGF-β1 to regulate inflammation. TIM3, which is highly expressed in the engineered EVs, mediates the release of anti-inflammatory cytokines by inhibiting the p38/MAPK pathway and promotes osseointegration by activating the Bmp2 promoter to enhance macrophage BMP2 secretion. After evenly loading the engineered EVs into the hydrogel, the continuous and slow release of EVsTIM3OE recruits more anti-inflammatory macrophages during the early stages of bone defect repair, regulating the immune microenvironment and eliminating the adverse effects of excessive inflammation. In summary, this study provides a new strategy for the treatment of refractory wounds through early inflammation control.

MAPK-dependent control of mitotic progression in S. pombe

BACKGROUND

Mitogen-activated protein kinases (MAPKs) preserve cell homeostasis by transducing physicochemical fluctuations of the environment into multiple adaptive responses. These responses involve transcriptional rewiring and the regulation of cell cycle transitions, among others. However, how stress conditions impinge mitotic progression is largely unknown. The mitotic checkpoint is a surveillance mechanism that inhibits mitotic exit in situations of defective chromosome capture, thus preventing the generation of aneuploidies. In this study, we investigate the role of MAPK Pmk1 in the regulation of mitotic exit upon stress.

RESULTS

We show that Schizosaccharomyces pombe cells lacking Pmk1, the MAP kinase effector of the cell integrity pathway (CIP), are hypersensitive to microtubule damage and defective in maintaining a metaphase arrest. Epistasis analysis suggests that Pmk1 is involved in maintaining spindle assembly checkpoint (SAC) signaling, and its deletion is additive to the lack of core SAC components such as Mad2 and Mad3. Strikingly, pmk1Δ cells show up to twofold increased levels of the anaphase-promoting complex (APC/C) activator Cdc20Slp1 during unperturbed growth. We demonstrate that Pmk1 physically interacts with Cdc20Slp1 N-terminus through a canonical MAPK docking site. Most important, the Cdc20Slp1 pool is rapidly degraded in stressed cells undergoing mitosis through a mechanism that requires MAPK activity, Mad3, and the proteasome, thus resulting in a delayed mitotic exit.

CONCLUSIONS

Our data reveal a novel function of MAPK in preventing mitotic exit and activation of cytokinesis in response to stress. The regulation of Cdc20Slp1 turnover by MAPK Pmk1 provides a key mechanism by which the timing of mitotic exit can be adjusted relative to environmental conditions.

The expression system influences stability, maturation efficiency, and oligomeric properties of the potassium-chloride co-transporter KCC2

The neuron-specific K+/Cl- co-transporter 2, KCC2, which is critical for brain development, regulates γ-aminobutyric acid-dependent inhibitory neurotransmission. Consistent with its function, mutations in KCC2 are linked to neurodevelopmental disorders, including epilepsy, schizophrenia, and autism. KCC2 possesses 12 transmembrane spans and forms an intertwined dimer. Based on its complex architecture and function, reduced cell surface expression and/or activity have been reported when select disease-associated mutations are present in the gene encoding the protein, SLC12A5. These data suggest that KCC2 might be inherently unstable, as seen for other complex polytopic ion channels, thus making it susceptible to cellular quality control pathways that degrade misfolded proteins. To test these hypotheses, we examined KCC2 stability and/or maturation in five model systems: yeast, HEK293 cells, primary rat neurons, and rat and human brain synaptosomes. Although studies in yeast revealed that KCC2 is selected for endoplasmic reticulum-associated degradation (ERAD), experiments in HEK293 cells supported a more subtle role for ERAD in maintaining steady-state levels of KCC2. Nevertheless, this system allowed for an analysis of KCC2 glycosylation in the ER and Golgi, which serves as a read-out for transport through the secretory pathway. In turn, KCC2 was remarkably stable in primary rat neurons, suggesting that KCC2 folds efficiently in more native systems. Consistent with these data, the mature glycosylated form of KCC2 was abundant in primary rat neurons as well as in rat and human brain. Together, this work details the first insights into the influence that the cellular and membrane environments have on several fundamental KCC2 properties, acknowledges the advantages and disadvantages of each system, and helps set the stage for future experiments to assess KCC2 in a normal or disease setting.

MAPK Cascades in Plant Microbiota Structure and Functioning

Mitogen-activated protein kinase (MAPK) cascades are highly conserved signaling modules that coordinate diverse biological processes such as plant innate immunity and development. Recently, MAPK cascades have emerged as pivotal regulators of the plant holobiont, influencing the assembly of normal plant microbiota, essential for maintaining optimal plant growth and health. In this review, we provide an overview of current knowledge on MAPK cascades, from upstream perception of microbial stimuli to downstream host responses. Synthesizing recent findings, we explore the intricate connections between MAPK signaling and the assembly and functioning of plant microbiota. Additionally, the role of MAPK activation in orchestrating dynamic changes in root exudation to shape microbiota composition is discussed. Finally, our review concludes by emphasizing the necessity for more sophisticated techniques to accurately decipher the role of MAPK signaling in establishing the plant holobiont relationship.

Beta-elemene: A phytochemical with promise as a drug candidate for tumor therapy and adjuvant tumor therapy

BACKGROUND

β-Elemene (IUPAC name: (1 S,2 S,4 R)-1-ethenyl-1-methyl-2,4-bis(prop-1-en-2-yl) cyclohexane), is a natural compound found in turmeric root. Studies have demonstrated its diverse biological functions, including its anti-tumor properties, which have been extensively investigated. However, these have not yet been reviewed. The aim of this review was to provide a comprehensive summary of β-elemene research, with respect to disease treatment.

METHODS

β-Elemene-related articles were found in PubMed, ScienceDirect, and Google Scholar databases to systematically summarize its structure, pharmacokinetics, metabolism, and pharmacological activity. We also searched the Traditional Chinese Medicine System Pharmacology database for therapeutic targets of β-elemene. We further combined these targets with the relevant literature for KEGG and GO analyses.

RESULTS

Studies on the molecular mechanisms underlying β-elemene activity indicate that it regulates multiple pathways, including STAT3, MAPKs, Cyclin-dependent kinase 1/cyclin B, Notch, PI3K/AKT, reactive oxygen species, METTL3, PTEN, p53, FAK, MMP, TGF-β/Smad signaling. Through these molecular pathways, β-elemene has been implicated in tumor cell proliferation, apoptosis, migration, and invasion and improving the immune microenvironment. Additionally, β-elemene increases chemotherapeutic drug sensitivity and reverses resistance by inhibiting DNA damage repair and regulating pathways including CTR1, pak1, ERK1/2, ABC transporter protein, Prx-1 and ERCC-1. Nonetheless, owing to its lipophilicity and low bioavailability, additional structural modifications could improve the efficacy of this drug.

CONCLUSION

β-Elemene exhibits low toxicity with good safety, inhibiting various tumor types via diverse mechanisms in vivo and in vitro. When combined with chemotherapeutic drugs, it enhances efficacy, reduces toxicity, and improves tumor killing. Thus, β-elemene has vast potential for research and development.

Periplogenin attenuates LPS-mediated inflammatory osteolysis through the suppression of osteoclastogenesis via reducing the NF-κB and MAPK signaling pathways

The key target for treating inflammatory osteolysis is osteoclasts. In an inflammatory environment, osteoclast differentiation increases, and bone resorption is enhanced. Periplogenin (Ppg) is a traditional Chinese medicine. It has anti-inflammatory and antitumor effects, but its impact on inflammatory osteolysis is unknown. This study found that Ppg prevented LPS-induced skull osteolysis by inhibiting the expression of inflammatory cytokines and osteoclast production. In vitro, Ppg blocked the RANKL-induced generation of osteoclasts, the development of pseudopodia bands, and bone resorption. Ppg also attenuated the expression of NFATc1, c-Fos, CTSK, and Atp6v0d2 proteins by inhibiting the NFATc1 signaling pathway. In addition, Ppg inhibited the expression of osteoclast-specific genes, including NFATc1, c-Fos, CTSK, Atp6v0d2, and Mmp9. Moreover, Ppg also inhibited NF-κB and MAPK pathways. In vivo, Ppg reduced the number of osteoclasts on the surface of the bone and suppressed LPS-induced osteolysis of the skull. These outcomes suggest that Ppg can serve as a new alternative therapy for treating inflammatory osteolysis by inhibiting inflammation and osteoclasts.

The cell cycle, autophagy, and cell wall integrity pathway jointly governed by MoSwe1 in Magnaporthe oryzae

The cell cycle is pivotal to cellular differentiation in plant pathogenic fungi. Cell wall integrity (CWI) signaling plays an essential role in coping with cell wall stress. Autophagy is a degradation process in which cells decompose their components to recover macromolecules and provide energy under stress conditions. However, the specific association between cell cycle, autophagy and CWI pathway remains unclear in model pathogenic fungi Magnaporthe oryzae. Here, we have identified MoSwe1 as the conserved component of the cell cycle in the rice blast fungus. We have found that MoSwe1 targets MoMps1, a conserved critical MAP kinase of the CWI pathway, through protein phosphorylation that positively regulates CWI signaling. The CWI pathway is abnormal in the ΔMoswe1 mutant with cell cycle arrest. In addition, we provided evidence that MoSwe1 positively regulates autophagy by interacting with MoAtg17 and MoAtg18, the core autophagy proteins. Moreover, the S phase initiation was earlier, the morphology of conidia and appressoria was abnormal, and septum formation and glycogen degradation were impaired in the ΔMoswe1 mutant. Our research defines that MoSWE1 regulation of G1/S transition, CWI pathway, and autophagy supports its specific requirement for appressorium development and virulence in plant pathogenic fungi. Video Abstract.

Mechanisms underlying sensing of cellular stress signals by mammalian MAP3 kinases

Cellular homeostasis is continuously challenged by environmental cues and cellular stress conditions. In their defense, cells need to mount appropriate stress responses that, dependent on the cellular context, signaling intensity, and duration, may have diverse outcomes. The stress- and mitogen-activated protein kinase (SAPK/MAPK) system consists of well-characterized signaling cascades that sense and transduce an array of different stress stimuli into biological responses. However, the physical and chemical nature of stress signals and how these are sensed by individual upstream MAP kinase kinase kinases (MAP3Ks) remain largely ambiguous. Here, we review the existing knowledge of how individual members of the large and diverse group of MAP3Ks sense specific stress signals through largely non-redundant mechanisms. We emphasize the large knowledge gaps in assigning function and stress signals for individual MAP3K family members and touch on the potential of targeting this class of proteins for clinical benefit.

Vasopressin V2 receptor, tolvaptan, and ERK1/2 phosphorylation in the renal collecting duct

Tolvaptan, a vasopressin antagonist selective for the V2-subtype vasopressin receptor (V2R), is widely used in the treatment of hyponatremia and autosomal-dominant polycystic kidney disease (ADPKD). Its effects on signaling in collecting duct cells have not been fully characterized. Here, we perform RNA-seq in a collecting duct cell line (mpkCCD). The data show that tolvaptan inhibits the expression of mRNAs that were previously shown to be increased in response to vasopressin including aquaporin-2, but also reveals mRNA changes that were not readily predictable and suggest off-target actions of tolvaptan. One such action is activation of the MAPK kinase (ERK1/ERK2) pathway. Prior studies have shown that ERK1/ERK2 activation is essential in the regulation of a variety of cellular and physiological processes and can be associated with cell proliferation. In immunoblotting experiments, we demonstrated that ERK1/ERK2 phosphorylation in mpkCCD cells was significantly reduced by vasopressin, in contrast to the increases seen in non-collecting-duct cells overexpressing V2R in prior studies. We also found that tolvaptan has a strong effect to increase ERK1/ERK2 phosphorylation in the presence of vasopressin and that tolvaptan's effect to increase ERK1/ERK2 phosphorylation is absent in mpkCCD cells in which both protein kinase A (PKA)-catalytic subunits have been deleted. Thus, it appears that the tolvaptan effect to increase ERK activation is PKA-dependent and is not due to an off-target effect of tolvaptan. We conclude that in cells expressing V2R at endogenous levels: 1) vasopressin decreases ERK1/ERK2 activation; 2) in the presence of vasopressin, tolvaptan increases ERK1/ERK2 activation; and 3) these effects are PKA-dependent.NEW & NOTEWORTHY Vasopressin is a key hormone that regulates the function of the collecting duct of the kidney. ERK1 and ERK2 are enzymes that play key roles in physiological regulation in all cells. The authors used collecting duct cell cultures to investigate the effects of vasopressin and the vasopressin receptor antagonist tolvaptan on ERK1 and ERK2 phosphorylation and activation.

MITOGEN-ACTIVATED PROTEIN KINASE3 enhances disease resistance of edr1 mutants by phosphorylating MAPKKK5

Mitogen-activated protein kinase (MAPK/MPK) cascades are key signaling modules that regulate plant immunity. ENHANCED DISEASE RESISTANCE1 (EDR1) encodes a Raf-like MAPK kinase kinase (MAPKKK) that negatively regulates plant defense in Arabidopsis (Arabidopsis thaliana). The enhanced resistance of edr1 requires MAPK KINASE4 (MKK4), MKK5, and MPK3. Although the edr1 mutant displays higher MPK3/6 activation, the mechanism by which plants increase MAPK cascade activation remains elusive. Our previous study showed that MAPKKK5 is phosphorylated at the Ser-90 residue in edr1 mutants. In this study, we demonstrated that the enhanced disease resistance of edr1 required MAPKKK5. Phospho-dead MAPKKK5S90A partially impaired the resistance of edr1, and the expression of phospho-mimetic MAPKKK5S90D in mapkkk5-2 resulted in enhanced resistance to the powdery mildew Golovinomyces cichoracearum strain UCSC1 and the bacterial pathogen Pseudomonas syringae pv. tomato (Pto) strain DC3000. Thus, Ser-90 phosphorylation in MAPKKK5 appears to play a crucial role in disease resistance. However, MAPKKK5-triggered cell death was not suppressed by EDR1. Furthermore, activated MPK3 phosphorylated the N terminus of MAPKKK5, and Ser-90 was one of the phosphorylated sites. Ser-90 phosphorylation increased MAPKKK5 stability, and EDR1 might negatively regulate MAPK cascade activation by suppressing the MPK3-mediated feedback regulation of MAPKKK5. Taken together, these results indicate that MPK3 phosphorylates MAPKKK5 to enhance MAPK cascade activation and disease resistance in edr1 mutants.