Mitogen-activated Protein Kinase Pathway Research Articles

Papillary thyroid cancer and its gene polymorphism; A molecular mechanistic perspective

Thyroid cancer stands as the predominant malignancy within the endocrine system, comprising about 1% of newly identified cancer instances. Papillary Thyroid Cancer (PTC) is the predominant form of thyroid cancer, representing 80% or more of thyroid malignancies. Thyroid carcinoma harbours assorted genetic alterations which are highly prevalent, several of these characteristics are unique to this form of cancer. The conventional oncogenic genetic modifications frequently observed in thyroid carcinoma encompass RAS mutations RET/PTC rearrangements and PAX8-peroxisome proliferator-activated receptor g (PPARg) fusion oncogene. The lately discovered activating mutation in BRAF (the gene for the B-type RAF kinase, BRAF) the most widespread genetic modification in thyroid cancer (30-83%). RKIP (RAF kinase inhibitory protein) had formerly been delineated as a phospholipid binding protein. Mammalian RKIP/PEBP differs from other identified proteins and its role is still being clarified. RKIP over-expression can inhibit MEK interaction with RAF-1 and B-RAF. It plays a role in thyroid cancer progression and lymph node metastasis. So, elucidating mutational profile and protein expression of above cell signalling molecules will be very useful in determining a proper therapeutic target for anti-cancer molecules. Given that tumors often possess numerous genetic and cell signalling abnormalities, thus inhibiting a single signalling pathway is often therapeutically inefficacious, more success could be foreseen with agents directed against multiple cellular pathways.By determining the genetic profile and protein expression of mentioned MAP Kinase pathway molecules new targets can be identified for chemotherapic drugs and novel strategies will be charted out to make modifications in the map kinase pathway with the aim to stop the occurrence and distant metastasis of thyroid cancer.

Enhancing m6A modification in the motor cortex facilitates corticospinal tract remodeling after spinal cord injury

Abstract Spinal cord injury typically causes corticospinal tract disruption. Although the disrupted corticospinal tract can self-regenerate to a certain degree, the underlying mechanism of this process is still unclear. N6-methyladenosine (m6A) modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes. However, whether m6A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown. We found that expression of methyltransferase 14 protein (METTL14) in the locomotor cortex was high after spinal cord injury and accompanied by elevated m6A levels. Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury. Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction, we found that METTL14 regulated Trib2 expression in an m6A-regulated manner, thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration. Finally, we administered syringin, a stabilizer of METTL14, using molecular docking. Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14. Findings from this study reveal that m6A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.

Coexisting RET/PTC and TERT Promoter Mutation Predict Poor Prognosis but Effective RET and MEK Targets in Thyroid Cancer.

To investigate the role of coexisting RET/PTC rearrangement and TERT promoter mutation in the prognosis and therapeutic targeting in papillary thyroid cancer (PTC). A total of 669 PTC patients with complete clinical follow-up and genetic data were pooled from thyroid cancer datasets TCGA, MSK MetTropism, and MSK-IMPACT, from whom 163 patients (112 women and 47 men, 4 unknown) with wild-type BRAF/RAS were identified, with median age (IQR) of 46.00 (33.00, 61.00) years and median follow-up time (IQR) of 16.13 (8.09, 27.91) months for comparative genotype cohort analysis of mortality. There was a significant concurrence index between RET/PTC and TERT promoter mutations, being 2.040 (95% CI 1.110-3.747, P = 0.023). Mortality occurred in 5/100 (5%) patients harboring neither mutation, 2/18 (11.1%) patients harboring TERT promoter mutation alone, 0/31 (0%) patients harboring RET/PTC alone, and 7/14 (50%) patients harboring both genetic alterations, corresponding to HRs (95% CI) of 1 (Reference), 2.469 (0.405-14.02), 3.296e-09 (0-inf), and 9.019 (2.635-30.87), respectively, which remained essentially unchanged after adjustment for patient race, sex, and age. Similar results were observed with BRAF/RAS and TERT promoter mutations. Mechanistically, RET/PTC used the MAP kinase pathway to upregulate the mutated TERT, but not the wild-type TERT, and, correspondingly, targeting RET and MEK could suppress mutated TERT but not the wild-type TERT. Coexisting RET/PTC and TERT promoter mutation identify PTC as a unique clinical entity with high mortality, providing new implications for genetic-based prognostication and potential therapeutic targeting of RET and MEK guided by RET/PTC and TERT status.

Lactobacillus paracasei Jlus66 relieves DSS-induced ulcerative colitis in a murine model by maintaining intestinal barrier integrity, inhibiting inflammation, and improving intestinal microbiota structure.

Ulcerative colitis (UC) is a serious health problem with increasing morbidity and prevalence worldwide. The pathogenesis of UC is complex, currently believed to be influenced by genetic factors, dysregulation of the host immune system, imbalance in the intestinal microbiota, and environmental factors. Currently, UC is typically managed using aminosalicylates, immunosuppressants, and biologics as adjunctive therapies, with the risk of relapse and development of drug resistance upon discontinuation. Therefore, further research into the pathogenesis of UC and exploration of potential treatment strategies are necessary to improve the quality of life for affected patients. According to previous studies, Lactobacillus paracasei Jlus66 (Jlus66) reduced inflammation and may help prevent or treat UC. We used dextran sulfate sodium (DSS) to induce a mouse model of UC to assess the effect of Jlus66 on the progression of colitis. During the experiment, we monitored mouse body weight, food and water consumption, as well as rectal bleeding. Hematoxylin-eosin staining was performed to assess intestinal pathological damage. Protein imprinting and immunohistochemical methods were used to evaluate the protein levels of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and tight junction (TJ) proteins in intestinal tissues. Fecal microbiota was analyzed based on partial 16S rRNA gene sequencing. Jlus66 supplementation reduced the degree of colon tissue damage, such as colon shortening, fecal occult blood, colon epithelial damage, and weight loss. Supplementation with Jlus66 reduced DSS-induced upregulation of cytokine levels such as TNF-α, IL-1β, and IL-6 (p < 0.05). The NF-κB pathway and MAPK pathway were inhibited, and the expression of TJ proteins (ZO-1, Occludin, and Claudin-3) was upregulated. 16S rRNA sequencing of mouse cecal contents showed that Jlus66 effectively regulated the structure of the intestinal biota. In conclusion, these data indicate that Jlus66 can alter the intestinal biota and slow the progression of UC, providing new insights into potential therapeutic strategies for UC.

MicroRNA-671-5p regulates the inflammatory response of periodontal ligament stem cells via the DUSP8/p38 MAPK pathway.

MicroRNAs are differentially expressed in periodontitis tissues. They are involved in cellular responses to inflammation and can be used as markers for diagnosing periodontitis. Microarray analysis showed that the expression level of microRNA-671-5p in periodontal tissues of patients with periodontitis was increased. In this study, we investigated the mechanism of action of microRNA-671-5p in human periodontal ligament stem cells (hPDLSCs) under inflammatory conditions. HPDLSCs were treated with lipopolysaccharide (LPS) to establish an inflammation model. The cell survival rate was determined using the cell counting kit-8 (CCK8). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analyses were used to detect the expression of microRNA-671-5p and dual-specificity phosphatase (DUSP) 8 proteins, respectively, Interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were detected using qRT-PCR and Enzyme-linked immunosorbent assay (ELISA). A dual-luciferase reporter system was employed to determine the relationship between micoRNA-671-5p and DUSP8 expression. Activation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway was confirmed using western blot analysis. Following the treatment of hPDLSCs with LPS, the expression levels of microRNA-671-5p in hPDLSCs were increased, cell viability decreased, and the expression of inflammatory factors displayed an increasing trend. MicroRNA-671-5p targets and binds to DUSP8. Silencing microRNA-671-5p or overexpressing DUSP8 can improve cell survival rate and reduce inflammatory responses. When DUSP8 was overexpressed, the expression of p-p38 was reduced. microRNA-671-5p targets DUSP8/p38 MAPK pathway to regulate LPS-induced proliferation and inflammation in hPDLSCs.

The ERK inhibitor GDC-0994 selectively inhibits growth of BRAF mutant cancer cells

BRAF or RAS mutation-induced aberrant activation of the mitogen-activated protein kinase (MAPK) pathway is frequently observed in human cancers. As the key downstream node of MAPK pathway, ERK1/2 is as an important therapeutic target. GDC-0994 (ravoxertinib), an orally bioavailable, highly selective small-molecule inhibitor of ERK1/2, showed acceptable safety and pharmacodynamic profile in a recent phase I clinical trial. In this study, we investigated dependence of the anti-tumor effect of ERK inhibitor GDC-0994 on genetic alterations in the MAPK pathway. The results showed that GDC-0994 sharply inhibited cell proliferation and colony formation and induced remarkable G1 phase cell-cycle arrest in cancer cells harboring BRAF mutation but had little effect on cell behaviors in most RAS mutant or wild-type cell lines. The expression of a large number of genes, particularly the genes in the cell cycle pathway, were significantly changed after GDC-0994 treatment in BRAF mutant cells, while no remarkable expression change of such genes was observed in wild-type cells. Moreover, GDC-0994 selectively inhibited tumor growth in a BRAF mutant xenograft mice model. Our findings demonstrate a BRAF mutation-dependent anti-tumor effect of GDC-0994 and provide a rational strategy for patient selection for ERK1/2 inhibitor treatment.

Chalcomoracin promotes apoptosis and endoplasmic reticulum stress in hepatocellular carcinoma cells.

Chalcomoracin (CMR), a Diels-Alder adduct obtained from mulberry leaves, demonstrated wide-spectrum anti-cancer activity. Herein, we aimed to explore the function of CMR and how it works in hepatocellular carcinoma (HCC). Human HCC cell lines Hep3B and SNU-387 were cultured and treated with various concentrations of CMR (1.5, 3, and 6 µM). Subsequently, the effects of CMR on cell viability, colony formation, apoptosis, migration, and invasion abilities were studied in vitro. Furthermore, the levels of endoplasmic reticulum (ER) stress-related proteins and mitogen-activated protein kinase (MAPK) pathway-related proteins in cells under CMR exposure were detected using western blot. Experiments in vivo were conducted to examine the effects of CMR on tumor growth in HCC. CMR administration inhibited the viability and clonogenic, migration, and invasion abilities, as well as promoted cell apoptosis and ER stress in Hep3B and SNU-387 cells. In addition, CMR treatment reduced the phosphorylation levels of ERK, P38, and JNK in the MAPK pathway. Moreover, an in vivo study showed that CMR administration could inhibit tumorigenesis and MAPK pathway activity in HCC. Our data indicate that CMR has the potential to inhibit the development of HCC, potentially through the inhibition of the MAPK pathway. These findings suggest that CMR may have promising applications as an anticancer agent in future therapeutics for HCC.

Functional transcriptome analysis revealed upregulation of MAPK-SMAD signalling pathways in chronic heat stress in crossbred cattle.

Animal geneticists and breeders have the impending challenge of enhancing the resilience of Indian livestock to heat stress through better selection strategies. Climate change's impact on livestock is more intense in tropical countries like India where dairy cattle crossbreeds are more sensitive to heat stress. The main reason for this study was to find the missing relative changes in transcript levels in thermo-neutral and heat stress conditions in crossbred cattle through whole-transcriptome analysis of RNA-Seq data. Differentially expressed genes (DEGs) identified based on the minimum log twofold change value and false discovery rate 0.05 revealed 468 up-regulated genes and 2273 down-regulated significant genes. Functional annotation and pathway analysis of these significant DEGs were compared based on Gene Ontology (Biological process), Kyoto Encyclopedia of Genes and Genome (KEGG), and Reactome pathways using g: Profiler, ShinyGO v0.76, and iDEP.951 web tools. On finding network visualization, the most over-represented and correlated pathways were neuronal and sensory organ development, calcium signalling pathway, Mitogen-activated protein kinase (MAPK) and Smad signalling pathway, Ras-proximate-1, or Ras-related protein 1 (Rap 1) signalling pathway, apoptosis, and oxidative stress. Similarly, down-regulated genes were most expressed in mRNA processing, immune system, B-cell receptor signalling pathway, Nucleotide oligomerization domain(NOD)-like receptors (NLRs) signalling pathway and nonsense-mediated decay (NMD) pathway. The heat stress-responsive genes identified in this study will facilitate our understanding of the molecular basis for climate resilience and heat tolerance in Indian dairy crossbreeds.

Microplastics and Oxidative Stress—Current Problems and Prospects

Microplastics (MPs) are plastic particles between 0.1 and 5000 µm in size that have attracted considerable attention from the scientific community and the general public, as they threaten the environment. Microplastics contribute to various harmful effects, including lipid peroxidation, DNA damage, activation of mitogen-activated protein kinase pathways, cell membrane breakages, mitochondrial dysfunction, lysosomal defects, inflammation, and apoptosis. They affect cells, tissues, organs, and overall health, potentially contributing to conditions like cancer and cardiovascular disease. They pose a significant danger due to their widespread occurrence in food. In recent years, information has emerged indicating that MPs can cause oxidative stress (OS), a known factor in accelerating the aging of organisms. This comprehensive evaluation exposed notable variability in the reported connection between MPs and OS. This work aims to provide a critical review of whether the harmfulness of plastic particles that constitute environmental contaminants may result from OS through a comprehensive analysis of recent research and existing scientific literature, as well as an assessment of the characteristics of MPs causing OS. Additionally, the article covers the analytical methodology used in this field. The conclusions of this review point to the necessity for further research into the effects of MPs on OS.

Mume Fructus reduces interleukin-1 beta-induced cartilage degradation via MAPK downregulation in rat articular chondrocytes.

Osteoarthritis is the most prevalent type of degenerative arthritis. It is characterized by persistent pain, joint dysfunction, and physical disability. Pain relief and inflammation control are prioritised during osteoarthritis treatment Mume Fructus (Omae), a fumigated product of the Prunus mume fruit, is used as a traditional medicine in several Asian countries. However, its therapeutic mechanism of action and effects on osteoarthritis and articular chondrocytes remain unknown. In this study, we analyzed the anti-osteoarthritis and articular regenerative effects of Mume Fructus extract on rat chondrocytes. Mume Fructus treatment reduced the interleukin-1β-induced expression of matrix metalloproteinase 3, matrix metalloproteinase 13, and a disintegrin and metalloproteinase with thrombospondin type 1 motifs 5. Additionally, it enhanced collagen type II alpha 1 chain and aggrecan accumulation in rat chondrocytes. Furthermore, Mume Fructus treatment regulated the inflammatory cytokine levels, mitogen-activated protein kinase phosphorylation, and nuclear factor-kappa B activation. Overall, our results demonstrated that Mume Fructus inhibits osteoarthritis progression by inhibiting the nuclear factor-kappa B and mitogen-activated protein kinase pathways to reduce the levels of inflammatory cytokines and prevent cartilage degeneration. Therefore, Mume Fructus may be a potential therapeutic option for osteoarthritis.

Predicting bladder cancer survival with high accuracy: insights from MAPK pathway-related genes

The mitogen-activated protein kinase (MAPK) pathway plays a critical role in tumor development and immunotherapy. Nevertheless, additional research is necessary to comprehend the relationship between the MAPK pathway and the prognosis of bladder cancer (BLCA), as well as its influence on the tumor immune microenvironment. To create prognostic models, we screened ten genes associated with the MAPK pathway using COX and least absolute shrinkage and selection operator (LASSO) regression analysis. These models were validated in the Genomic Data Commons (GEO) cohort and further examined for immune infiltration, somatic mutation, and drug sensitivity characteristics. Finally, the findings were validated using The Human Protein Atlas (HPA) database and through Quantitative Real-time PCR (qRT-PCR). Patients were classified into high-risk and low-risk groups based on the prognosis-related genes of the MAPK pathway. The high-risk group had poorer overall survival than the low-risk group and showed increased immune infiltration compared to the low-risk group. Additionally, the nomograms built using the risk scores and clinical factors exhibited high accuracy in predicting the survival of BLCA patients. The prognostic profiling of MAPK pathway-associated genes represents a potent clinical prediction tool, serving as the foundation for precise clinical treatment of BLCA.

Mefunidone ameliorates acute liver failure in mice by inhibiting MKK4-JNK pathway

Acute liver failure (ALF) is a critical condition that can lead to substantial liver dysfunction. It is characterized by complex clinical manifestations and rapid progression, presenting significant challenges in diagnosis and treatment. We investigated the protective effect of mefunidone (MFD), a novel antifibrosis pyridone agent, on ALF in mice, and explored its potential mechanism of action. MFD pretreatment can alleviate lipopolysaccharide (LPS) and d-galactosamine (D-GalN)-induced ALF, reduce hepatocyte apoptosis, and reduce inflammation and oxidative stress. Additionally, MFD alleviated LPS/D-GalN-stimulated reactive oxygen species (ROS) production and cell death in AML12 cells. RNA sequencing enrichment analysis showed that MFD significantly affected the Mitogen-Activated Protein Kinase (MAPK) pathway. In vivo and in vitro experiments showed that MFD inhibited MKK4 and JNK phosphorylation. JNK activation caused by MKK4 and JNK activators could eliminate the therapeutic effect of MFD on AML12. In addition, MFD pretreatment alleviated ConA-induced ALF, reduced inflammation and oxidative stress in mice, and reduced mouse mortality. These results suggest that MFD can potentially protect against ALF, partially by inhibiting the MKK4-JNK pathway, and is a promising new therapeutic drug for ALF.

Role of MEK1 and DIAPH3 expression in colorectal adenoma-carcinoma sequence.

It is well established that most colorectal carcinomas arise from conventional adenomas through the adenoma-carcinoma sequence (ACS) model. mitogen-activated protein kinases (MAPKs) pathway has been reported as a crucial player in tumorigenesis. The MAPK signaling pathway is activated by different extracellular signals involving the "mitogen-activated/extracellular signal-regulated kinase 1 (MEK1)", and this induces the expression of genes involved in proliferation and cellular transformation. Diaphanous-related formin-3 (DIAPH3) acts as a potential metastasis regulator through inhibiting the cellular transition to amoeboid behavior in different cancer types. The aim of the study was to investigate the pattern of immunohistochemical expression of MEK1 and DIAPH3 in colorectal adenoma (CRA) and corresponding colorectal carcinoma (CRC) specimens. The immunohistochemical expression of DIAPH3 and MEK1 was examined in 43 cases of CRC and their associated adenomas using tissue microarray technique. MEK1 was overexpressed in 23 CRC cases (53.5%) and in 20 CRA cases (46.5%). DIAPH3 was overexpressed in 11 CRA cases (about 29%) which were significantly lower than CRC (22 cases; 58%) (P = 0.011). Both MEK1 and DIAPH3 overexpression were significantly correlated in CRC (P = 0.009) and CRA cases (P = 0.002). Tumors with MEK1 overexpression had a significantly higher tumor grade (P = 0.050) and perineural invasion (P = 0.017). Both MEK1 and DIAPH3 are overexpressed across colorectal ACS with strong correlation between them. This co- expression suggests a possible synergistic effect of MEK1 and DIAPH-3 in colorectal ACS. Further large-scale studies are required to investigate the potential functional aspects of MEK1 and DIAPH3 in ACS and their involvement in tumor initiation and the metastatic process.

D-mannose alleviates intervertebral disc degeneration through glutamine metabolism

BackgroundIntervertebral disc degeneration (IVDD) is a multifaceted condition characterized by heterogeneity, wherein the balance between catabolism and anabolism in the extracellular matrix of nucleus pulposus (NP) cells plays a central role. Presently, the available treatments primarily focus on relieving symptoms associated with IVDD without offering an effective cure targeting its underlying pathophysiological processes. D-mannose (referred to as mannose) has demonstrated anti-catabolic properties in various diseases. Nevertheless, its therapeutic potential in IVDD has yet to be explored.MethodsThe study began with optimizing the mannose concentration for restoring NP cells. Transcriptomic analyses were employed to identify the mediators influenced by mannose, with the thioredoxin-interacting protein (Txnip) gene showing the most significant differences. Subsequently, small interfering RNA (siRNA) technology was used to demonstrate that Txnip is the key gene through which mannose exerts its effects. Techniques such as colocalization analysis, molecular docking, and overexpression assays further confirmed the direct regulatory relationship between mannose and TXNIP. To elucidate the mechanism of action of mannose, metabolomics techniques were employed to pinpoint glutamine as a core metabolite affected by mannose. Next, various methods, including integrated omics data and the Gene Expression Omnibus (GEO) database, were used to validate the one-way pathway through which TXNIP regulates glutamine. Finally, the therapeutic effect of mannose on IVDD was validated, elucidating the mechanistic role of TXNIP in glutamine metabolism in both intradiscal and orally treated rats.ResultsIn both in vivo and in vitro experiments, it was discovered that mannose has potent efficacy in alleviating IVDD by inhibiting catabolism. From a mechanistic standpoint, it was shown that mannose exerts its anti-catabolic effects by directly targeting the transcription factor max-like protein X-interacting protein (MondoA), resulting in the upregulation of TXNIP. This upregulation, in turn, inhibits glutamine metabolism, ultimately accomplishing its anti-catabolic effects by suppressing the mitogen-activated protein kinase (MAPK) pathway. More importantly, in vivo experiments have further demonstrated that compared with intradiscal injections, oral administration of mannose at safe concentrations can achieve effective therapeutic outcomes.ConclusionsIn summary, through integrated multiomics analysis, including both in vivo and in vitro experiments, this study demonstrated that mannose primarily exerts its anti-catabolic effects on IVDD through the TXNIP-glutamine axis. These findings provide strong evidence supporting the potential of the use of mannose in clinical applications for alleviating IVDD. Compared to existing clinically invasive or pain-relieving therapies for IVDD, the oral administration of mannose has characteristics that are more advantageous for clinical IVDD treatment.

Natural Compounds for Bone Remodeling: A Computational and Experimental Approach Targeting Bone Metabolism-Related Proteins.

Osteoporosis, characterized by reduced bone density and increased fracture risk, affects over 200 million people worldwide, predominantly older adults and postmenopausal women. The disruption of the balance between bone-forming osteoblasts and bone-resorbing osteoclasts underlies osteoporosis pathophysiology. Standard treatment includes lifestyle modifications, calcium and vitamin D supplementation and specific drugs that either inhibit osteoclasts or stimulate osteoblasts. However, these treatments have limitations, including side effects and compliance issues. Natural products have emerged as potential osteoporosis therapeutics, but their mechanisms of action remain poorly understood. In this study, we investigate the efficacy of natural compounds in modulating molecular targets relevant to osteoporosis, focusing on the Mitogen-Activated Protein Kinase (MAPK) pathway and the gut microbiome's influence on bone homeostasis. Using an in silico and in vitro methodology, we have identified quercetin as a promising candidate in modulating MAPK activity, offering a potential therapeutic perspective for osteoporosis treatment.

NRASQ61R mutation drives elevated angiopoietin-2 expression in human endothelial cells and a genetic mouse model.

Angiopoietin-2 (Ang-2) is increased in the blood of patients with kaposiform lymphangiomatosis (KLA) and kaposiform hemangioendothelioma (KHE). While the genetic causes of KHE are not clear, a somatic activating NRASQ61R mutation has been found in the lesions of KLA patients. Our study tested the hypothesis that the NRASQ61R mutation drives elevated Ang-2 expression in endothelial cells. Ang-2 was measured in human endothelial progenitor cells (EPC) expressing NRASQ61R and a genetic mouse model with endothelial targeted NRASQ61R. To determine the signaling pathways driving Ang-2, NRASQ61R EPC were treated with signaling pathway inhibitors. Ang-2 levels were increased in EPC expressing NRASQ61R compared to NRASWT by Western blot analysis of cell lysates and ELISA of the cell culture media. Ang-2 levels were elevated in the blood of NRASQ61R mutant mice. NRASQ61R mutant mice also had reduced platelet counts and splenomegaly with hypervascular lesions, like some KLA patients. mTOR inhibitor rapamycin attenuated Ang-2 expression by NRASQ61R EPC. However, MEK1/2 inhibitor trametinib was more effective blocking increases in Ang-2. Our studies show that the NRASQ61R mutation in endothelial cells induces Ang-2 expression in vitro and in vivo. In cultured human endothelial cells, NRASQ61R drives elevated Ang-2 through MAP kinase and mTOR-dependent signaling pathways.

Beta-cyfluthrin impairs implantation process by inducing mitochondrial defects and changes in reactive oxygen species-mediated signaling pathways in porcine trophectoderm and uterine luminal epithelial cells

Pyrethroid insecticides, such as beta-cyfluthrin, are used extensively globally, including in households and agriculture, and have been detected in the milk and urine of humans and cattle. Beta-cyfluthrin exhibits toxic effects, including neurotoxicity and male reproductive toxicity; however, few studies have investigated female reproductive toxicity despite its wide environmental distribution. The present study investigates effects of beta-cyfluthrin on implantation in porcine cells (pTr from the trophectoderm and pLE from the endometrial luminal epithelium). To identify the various physiological changes induced by beta-cyfluthrin, such as apoptosis and lipid peroxidation, flow cytometry analysis and immunofluorescence were performed with various reagents. In addition, the expression of genes and proteins associated with intracellular changes was confirmed using qRT-PCR and western blotting. Beta-cyfluthrin induced cell-cycle arrest and altered intracellular calcium flux. It also disrupted the mitochondrial function and promoted reactive oxygen species (ROS) production, leading to lipid peroxidation. Moreover, ROS induced by beta-cyfluthrin altered mitogen-activated protein kinase (MAPK) pathways and decreased cell migration capability. The expression levels of genes that are significant during early pregnancy were altered by beta-cyfluthrin in both cell lines. The changes resulted in apoptosis and diminished cell proliferation of pTr and pLE. Collectively, the results imply that beta-cyfluthrin disrupts the implantation process by affecting the physiology of the trophectoderm and endometrial luminal epithelial cells. The present study is the first to reveal the cellular mechanisms of beta-cyfluthrin on the female reproductive system and highlights the need for further in-depth research into its hazards.

Tectorigenin inhibits inflammatory responses in murineinflammatory bowel disease and LPS-stimulated macrophages via inactivating MAPK signaling pathway.

Considering the antihepatitis effects of Tectorigenin (TEC), and the same adenosine mitogen-activated protein kinase (MAPK) pathway in both hepatitis and inflammatory bowel disease (IBD) models, exploring the role of TEC in IBD is contributive to develop a new treatment strategy against IBD. The IBD mouse model was constructed by feeding with dextran sodium sulfate (DSS) and injection of TEC. Afterward, the mouse body weight, colon length, and disease activity index (DAI) were tested to assess the enteritis level. Mouse intestine lesions were detected by hematoxylin and eosin staining. Murine macrophages underwent lipopolysaccharide (LPS) induction to establish an inflammation model. Cell viability was determined by cell counting kit-8 assay. Enzyme-linked immunosorbent assay was performed to measure interleukin 6(IL-6) and tumor necrosis factor-α (TNF-α) levels. Cyclooxygenase-2(COX-2) and inducible nitric oxide synthase(iNOS) expressions were quantified via quantitative reverse transcription polymerase chain reaction. Levels of MAPK pathway-related proteins (p-P38, P38, p-Jun N-terminal kinase(JNK), JNK, signal-regulated kinase(ERK), p-ERK), COX-2 and iNOS were quantitated by Western blot. TEC improved the inflammatory response through ameliorating weight loss, shortening colon, and increasing DAI score in IBD mouse. Expressions of intestinal inflammatory factors (IL-6, TNF-α, iNOS and COX-2) and MAPK pathway-related proteins (p-P38, p-JNK, and p-ERK) were increased both in DSS-induced mouse intestinal tissue, but TEC inhibited expressions of inflammatory factors. The same increased trend was identified in LPS-induced macrophages, but TEC improved macrophage inflammation, as evidenced by downregulation of inflammatory factors. TEC mitigates IBD and LPS-induced macrophage inflammation in mice via inhibiting MAPK signaling pathway.

Revisiting the Role of B-RAF Kinase as a Therapeutic Target in Melanoma.

Malignant melanoma is the rarest but most aggressive and deadly skin cancer. Melanoma is the result of a malignant transformation of melanocytes, which leads to their uncontrolled proliferation. Mutations in the mitogen-activated protein kinase (MAPK) pathway, which are crucial for the control of cellular processes, such as apoptosis, division, growth, differentiation, and migration, are one of its most common causes. BRAF kinase, as one of the known targets of this pathway, has been known for many years as a prominent molecular target in melanoma therapy, and the following mini-review outlines the state-of-the-art knowledge regarding its structure, mutations and mechanisms.

ALDH1A1 confers resistance to RAF/MEK inhibitors in melanoma cells by maintaining stemness phenotype and activating PI3K/AKT signaling

The mitogen-activated protein kinase (MAPK/ERK) pathway is pivotal in controlling the proliferation and survival of melanoma cells. Several mutations, including those in BRAF, exhibit an oncogenic effect leading to increased cellular proliferation. As a result, the combination therapy of a MEK inhibitor with a BRAF inhibitor demonstrated higher efficacy and lower toxicity than BRAF inhibitor alone. This combination has become the preferred standard of care for tumors driven by BRAF mutations.Aldehyde dehydrogenase 1A1 (ALDH1A1) is a known marker of stemness involved in drug resistance in several type of tumors, including melanoma. This study demonstrates that melanoma cells overexpressing ALDH1A1 displayed resistance to vemurafenib and trametinib through the activation of PI3K/AKT signaling instead of MAPK axis. Inhibition of PI3K/AKT signaling partially rescued sensitivity to the drugs. Consistently, pharmacological inhibition of ALDH1A1 activity downregulated the activation of AKT and partially recovered responsiveness to vemurafenib and trametinib. We propose ALDH1A1 as a new potential target for treating melanoma resistant to MAPK/ERK inhibitors.