Extracellular Signal-regulated Kinase Pathway Research Articles

High ambient temperature may induce presbyopia via TRPV1 activation.

The prevalence of presbyopia and nuclear cataracts (NUC) is reported to be higher in tropical areas than that in other regions, suggesting a potential influence of high temperatures on lens health. Transient receptor potential vanilloid (TRPV) channels play a crucial role in detecting ambient temperatures across various species, with TRPV1 and TRPV4 expressed in lens epithelial cells. In this study, we investigated whether ambient temperatures affect TRPV1 and TRPV4 activity in the lens, potentially contributing to the development of presbyopia and NUC. We conducted experiments using cultured human lens epithelial cell lines under different temperature conditions. Our results revealed that the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and p38 pathways, downstream molecules of TRPV1, were activated, while Src family kinase, a downstream molecule of TRPV4, was inhibited at 37.5°C culture compared to 35.0°C. Confocal microscope images demonstrated higher expression of TRPV1 in 3D-structured cells under high-temperature culture conditions. Additionally, in organ culture lenses, higher elasticity was observed at elevated temperatures compared to that at lower temperatures. These results suggest that high ambient temperatures may induce lens sclerosis via TRPV1 activation, potentially contributing to the development of presbyopia and NUC.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway;, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β;, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.

Stable inhibition of choroidal neovascularization by adeno-associated virus 2/8-vectored bispecific molecules.

Neovascular age-related macular degeneration (nAMD) causes severe visual impairment. Pigment epithelium-derived factor (PEDF), soluble CD59 (sCD59), and soluble fms-like tyrosine kinase-1 (sFLT-1) are potential therapeutic agents for nAMD, which target angiogenesis and the complement system. Using the AAV2/8 vector, two bi-target gene therapy agents, AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59, were generated, and their therapeutic efficacy was investigated in laser-induced choroidal neovascularization (CNV) and Vldlr-/- mouse models. After a single injection, AAV2/8-mediated gene expression was maintained at high levels in the retina for two months. Both AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 significantly reduced CNV development for an extended period without side effects and provided efficacy similar to two injections of current anti-vascular endothelial growth factor monotherapy. Mechanistically, these agents suppressed the extracellular signal-regulated kinase and nuclear factor-κB pathways, resulting in anti-angiogenic activity. This study demonstrated the safety and long-lasting effects of AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 in CNV treatment, providing a promising therapeutic strategy for nAMD.

Functional Role of DUSP6 in the EGFR-mediated Progression of Head and Neck Squamous Cell Carcinoma.

Epidermal growth factor receptor (EGFR) over-expression is commonly observed in advanced head and neck squamous cell carcinoma (HNSCC) and is correlated with poor patient outcomes. However, the role of dual-specificity phosphatase 6 (DUSP6) in EGFR-associated HNSCC progression remains poorly understood. This study aimed to investigate the correlation between DUSP6 expression and EGFR signaling in malignant HNSCC tissues. Data mining and in vitro assays were employed to assess DUSP6 expression levels in HNSCC tissues compared to normal tissues. Additionally, the correlation between DUSP6 and EGFR expression was examined. Functional assays were conducted to investigate the modulation of DUSP6 expression by EGFR signaling and its involvement in EGF-induced cell migration and anoikis resistance. Our analysis revealed a significant elevation in DUSP6 expression in HNSCC tissues compared to normal tissues and a strong correlation between DUSP6 and EGFR expression. EGFR signaling modulated DUSP6 expression in a dose- and time-dependent manner, primarily through the extracellular signal-regulated kinase (ERK) pathway. Knockdown experiments demonstrated the functional role of DUSP6 in EGF-induced cell migration and anoikis resistance. The findings of this study elucidate the intricate signaling networks governing DUSP6 expression and its interplay with EGFR signaling in HNSCC. Moreover, the results provide insights into the potential role of DUSP6 as a therapeutic target and highlight the importance of personalized treatment strategies in HNSCC management.

Beneficial effect of heat-killed Lactiplantibacillus plantarum L-137 on intestinal barrier function of rat small intestinal epithelial cells

Heat-killed Lactiplantibacillus plantarum L-137 (HK L-137) has been suggested to enhance the intestinal barrier in obese mice, leading to improvement of metabolic abnormalities and adipose tissue inflammation, and in healthy humans with overweight, leading to improvement of systemic inflammation. However, its detailed mechanism of action has not been clarified. Therefore, this study investigated the effects of HK L-137 on the permeability of rat small intestinal epithelial IEC-6 cells, tight junction-related gene and protein expression and localization, and intracellular signaling pathways involved in barrier function. Treatment of IEC-6 cells with HK L-137 for 26 h significantly reduced the permeability to fluorescein isothiocyanate-dextran (FD-4). HK L-137 also increased gene and protein expression of zonula occludens-1 (ZO-1), an important tight junction protein, without affecting the localization. Furthermore, inhibition of the extracellular signal-regulated kinase (ERK)1/2 pathway in IEC-6 cells canceled the HK L-137-related reduction in permeability to FD-4. Phosphorylation of ERK in IEC-6 cells was induced 15 min after the addition of HK L-137. These results suggest that HK L-137 reduces intestinal permeability partly through activating the ERK pathway and increasing expression of the ZO-1 gene and protein. Enhancement of intestinal barrier function with HK L-137 might be effective in preventing and treating leaky gut, for which no specific therapeutic tool has been established.

Quercetin ameliorates lipid deposition in primary hepatocytes of the chicken embryo

ABSTRACT 1. The accumulation of excessive fat plays a role in the development of non-alcoholic fatty liver disease (NAFLD) and phytogenic feed additives have the potential to ameliorate this. This study involved the isolation and culture of primary hepatocytes from chicken embryos to establish a model of hepatic steatosis induced by oleic acid/dexamethasone (OA/DEX). Lipid accumulation and cell viability were assessed using Nile Red staining, Oil Red O staining and cell count Kit −8 (CCK8) following treatment with varying concentrations of quercetin (Que). The potential mechanism by which Que exerts its effects was preliminarily investigated. 2. The results indicated that OA effectively treated lipid accumulation in hepatocytes. There was no notable variance in cell proliferation between the normal and OA/DEX groups when subjected to Que treatment at concentrations of 1000 ng/ml and 10 000 ng/ml. Triglycerides and cholesterol (low and high density) decreased with Que treatment, with the most substantial reduction observed at 10 000 ng/ml. 3. Gene expression levels decreased to levels similar to those in the control groups. Western blot data demonstrated that sterol regulatory element-binding protein 1 (SREBP-1) protein expression correlated with its mRNA expression level. Que mitigated lipid accumulation through the alpha serine/threonine protein kinase (AKT) and extracellular signal-regulated kinase (ERK) pathways. Expression levels of lipid-related genes (APOB, PPARα, CYP3A5 and SREBP-1) decreased to levels similar to the control groups. Western blot data demonstrated that the SREBP-1 protein expression correlated with its mRNA expression level. 4. Supplementation with Que ameliorated lipid accumulation through AKT and ERK signalling pathway in OA/DEX-induced high-fat hepatocytes.

Role of ERK and NF-KB pathway in neurally mediated enhanced expression and traffcking of SGLT2 in congestive heart failure

Congestive heart failure (CHF) is characterized by the activation of neurohumoral systems concomitant with avid fluid retention. Recently we showed enhanced expression of sodium-glucose cotransporter 2 (SGLT2) in rats with CHF. However, the exact molecular mechanism linking enhanced sympathetic tone and enhanced expression and translocation of SGLT2 in CHF is not clear. The objective of this study was to investigate the role of enhanced sympathetic tone on the expression and traffcking of SGLT2 via activation of protein kinase A (PKA), extracellular signal-regulated kinases (ERK), and nuclear factor kappa B (NF-KB) in the renal cortex of CHF rats. Male Sprague Dawley rats were subjected to either the left coronary artery ligation for the CHF group or Sham surgery. Four weeks after surgery, expression of protein levels (PKA, ERK and NF-KB) were assessed by Western blotting, whereas the location of SGLT2 expression was determined by immunohistological and immunofluorescent staining in the cortical region of kidneys from Sham and CHF rats. Effect of exogenous norepinephrine (NE) (10μM for 24hrs) on expression and traffcking of SGLT2, phosphorylation of ERK and NF-KB in HK2 cells were examined in an in vitro model. Expression of SGLT2 was significantly enhanced in the renal cortex of rats with CHF versus Sham (0.83±0.06 vs. 0.58±0.02). Also, the translocation of SGLT2 was significantly enhanced towards the membrane in CHF rats (0.92±0.11 vs. 0.33±0.07). Phosphorylation of PKA (0.05±0.01 vs. 0.01±0.01), ERK (0.32±0.02 vs. 0.23±0.02) and NF-KB (0.71±0.14 vs. 0.08±0.06) were significantly enhanced in CHF compared to Sham. NE treatment significantly increased expression of SGLT2 (0.26±0.03 vs. 0.15±0.02), traffcking of SGLT2 (0.45 ± 0.09 vs. 0.15 ± 0.03) towards membrane, phosphorylation of ERK (0.38±0.05 vs. 0.14±0.02) and NF-KB (0.61±0.08 vs. 0.17±0.07) in HK2 cells. Thus, NE treatment enhanced the phosphorylation of ERK, NF-kB as well as traffcking of SGLT2. Immunohistological and immunofluorescent staining demonstrated increased expression of SGLT2 in the kidneys of rats with CHF. Similar results were observed in immunofluorescent staining of human kidney cells treated with NE. In conclusion, these findings indicate that NE activates ERK and NF-KB pathways which leads to enhanced traffcking and overexpression of SGLT2 in CHF. These results provide a molecular link between enhanced sympathetic tone, ERK and NF-KB pathway and the traffcking of SGLT2 to the luminal membrane of renal proximal tubular cells and consequent increase in sodium retention in rats with CHF. This study was funded by NIH R01-DK-129311. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Protective Effect of Curcumin on the Tight Junction Integrity and Cellular Senescence in Human Retinal Pigment Epithelium of Early Diabetic Retinopathy.

Diabetic retinopathy (DR) is a secondary complication of diabetes that can lead to visual impairment and blindness. The retinal pigment epithelium (RPE) is a monolayer of pigment cells that forms the blood-retinal barrier (BRB) via tight junction (TJ) proteins and plays a crucial role in the physiological function of the retina. Hyperglycemia induces RPE death and BRB breakdown, which accelerates the process of DR. Curcumin, an active extract of Curcuma longa , has anti-inflammatory, antioxidant, antiapoptotic, and neuroprotective properties. However, the effect of Curcumin on the BRB under high glucose conditions remains unknown. This study aimed to investigate the protective effects of Curcumin on RPE physiology in vitro and in vivo . Curcumin significantly alleviated cell viability inhibition under high glucose conditions. Moreover, high glucose reduced extracellular signal-regulated kinase and Akt pathways activation to diminish RPE cell growth but reversed by Curcumin treatment. Curcumin protected not only TJ integrity but also retinoid regeneration through TJ proteins and isomerase modulation in diabetic retina. Furthermore, Curcumin decreased the expression of angiogenic factor to inhibit retinal neovascularization. Finally, Curcumin treatment markedly reduced apoptosis during hyperglycemia. In conclusion, Curcumin can alleviate the progression of DR by promoting RPE survival, TJ integrity, retinoid isomerase activity, RPE senescence inhibition, and neovascularization. Therefore, Curcumin exhibits high potential for use as a therapeutic agent for early DR.

BIRC3-HSP90B1 Interaction Inhibits Non-Small Cell Lung Cancer Progression through the Extracellular Signal-Regulated Kinase Pathway.

The long-term prognosis of nonsmall cell lung cancer (NSCLC) remains unsatisfactory, which is a major challenge in lung cancer treatment. BIRC3 is an inhibitor of apoptosis (IAP) protein that contributes to tumor regulation. However, the underlying regulatory mechanisms of BIRC3 in NSCLC remains unknown. We initiated an analysis of BIRC3 expression data in NSCLC tumors and adjacent tissues using the TCGA and GEO databases and examined the variations in prognosis. Further, we conducted overexpression (OE) and knockdown (KD) studies on BIRC3 to evaluate its effects on NSCLC cell proliferation, migration, and invasion. Additionally, through utilization of a nude mouse model, the regulatory effects of BIRC3 on NSCLC were verified in vivo. Co-immunoprecipitation (Co-IP) assay served to pinpoint the proteins with which BIRC3 interacts. The results indicated that BIRC3 is down-regulated in NSCLC tissues and that patients with high BIRC3 expression demonstrate a better prognosis. BIRC3 is a tumor suppressor, inhibiting the proliferation and metastasis of NSCLC. Co-IP results revealed that BIRC3 interacts with HSP90B1, leading to a decrease in HSP90B1 expression and subsequent negative regulation of the ERK signaling pathway. BIRC3 may serve as a prognostic biomarker for NSCLC. It directly interacts with HSP90B1 to negatively regulate the ERK signaling pathway, thereby hindering the progression of NSCLC.

MUC16 can Predict the Pregnancy Outcomes in Human and Intraperitoneal Administration of MUC16 can Rescue Pregnancy Losses in Mouse Models.

Mucin 16 (MUC16) participates in the process of embryo implantation, but few studies have examined the association between MUC16 and pregnancy loss. To investigate this association, the expression of MUC16 in serum and decidua was compared between women with pregnancy loss and ongoing pregnancies. In vitro experiments and animal models were used to explore the role and underlying mechanisms of MUC16 in pregnancy loss. In human study, the expression of MUC16 in serum and decidua was both consistently lower in the women with pregnancy loss compared with those in women with ongoing pregnancies. In vitro experiments revealed the interaction of MUC16 with peripheral blood natural killer (pNK) cells. MUC16 changed the phenotype and reduced the pro-inflammation ability of pNK cells. MUC16 also inhibited the cytotoxicity of pNK cells through the Src homology region 2 domain-containing phosphatase-1/extracellular signal-regulated kinase (SHP-ERK) pathway. Furthermore, MUC16 promoted the migration, invasion and tube formation of trophoblast cells by co-culturing together with pNK cells. In vivo experiments, the mouse model of abortion was used to further confirm that intraperitoneal administration of MUC16 could rescue the pregnancy loss. This study reveals the still-unknown connection between MUC16 and pNK cells and indicates that MUC16 provides a novel method for future prediction and treatment of unfavorable pregnancy outcomes.

Lacticaseibacillus casei K11 exerts immunomodulatory effects by enhancing natural killer cell cytotoxicity via the extracellular regulated-protein kinase pathway.

Probiotics can serve as immunomodulators that regulate the activation of immune cells. This study aimed to screen potential probiotic strains that can enhance NK cell toxicity to improve host immunity. In this investigation, we examined three potential probiotic strains, namely Lactiplantibacillus plantarum YZX21 (YZX21), Bifidobacterium bifidum FL-276.1 (FL-276.1) and Lacticaseibacillus casei K11 (K11), to assess their capacity in modulating NK cytotoxicity both in vitro and in vivo, while elucidating the underlying mechanisms involved. The findings demonstrated that K11 exhibited superior efficacy in enhancing NK cytotoxicity. Subsequent analysis revealed that K11 significantly augmented the secretion of perforin and granzyme B by NK cells through activation of receptors NKp30 and NKp46 via the extracellular signal-regulated kinase (ERK) pathway. Furthermore, heat-inactivated K11 also enhanced NK cell activity to an extent comparable to live bacteria, with lipoteichoic acid from K11 identified as a crucial factor mediating the activation of NK cell cytotoxicity. Our study suggests that K11 may have potential applications as probiotics or postbiotics for regulating NK cell cytotoxicity to enhance immunity.

The S1 spike protein of SARS-CoV-2 upregulates the ERK/MAPK signaling pathway in DC-SIGN-expressing THP-1 cells.

Dendritic cells, macrophages, neutrophils, and other antigen-presenting cells express various C-type lectin receptors that function to recognize the glycans associated with pathogens. The dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) binds various pathogens such as HIV glycoprotein 120, the Ebola glycoprotein, hemagglutinin, and the dengue virus glycoprotein in addition to the SARS-CoV-2 spike protein, and also triggers antigen-presenting cell endocytosis and immune escape from systemic infections. Many studies on the binding of SARS-CoV-2 spike protein with glycans have been published, but the underlying mechanism by which intracellular signaling occurs remains unclear. In this study, we report that the S1 spike protein of SARS-CoV-2 induces the phosphorylation of extracellular signal-regulated kinases (ERKs) in THP-1 cells, a DC-SIGN-expressing human monocytic leukemic cell line. On the other hand, the phosphorylation level of NF-κB remained unchanged under the same conditions. These data suggest that the major cell signaling pathway regulated by the S1 spike protein is the ERK pathway, which is superior to the NF-κB pathway in these DC-SIGN-expressing THP-1 cells and may contribute to immune hyperactivation in SARS-CoV-2 infections. Additionally, several glycans such as mannans, mannosylatedbovine serum albumin, the serum amyloid beta protein, andintracellular adhesion molecule 3 suppressed ERKphosphorylation,suggesting that these molecules are target molecules for SARS-CoV-2 infection by suppressing immune hyperactivation that occurs in the ERK signaling pathway.

ELABELA-derived peptide ELA13 attenuates kidney fibrosis by inhibiting the Smad and ERK signaling pathways.

Kidney fibrosis is an inevitable result of various chronic kidney diseases (CKDs) and significantly contributes to end-stage renal failure. Currently, there is no specific treatment available for renal fibrosis. ELA13 (amino acid sequence: RRCMPLHSRVPFP) is a conserved region of ELABELA in all vertebrates; however, its biological activity has been very little studied. In the present study, we evaluated the therapeutic effect of ELA13 on transforming growth factor-β1 (TGF-β1)-treated NRK-52E cells and unilateral ureteral occlusion (UUO) mice. Our results demonstrated that ELA13 could improve renal function by reducing creatinine and urea nitrogen content in serum, and reduce the expression of fibrosis biomarkers confirmed by Masson staining, immunohistochemistry, real-time polymerase chain reaction (RT-PCR), and western blot. Inflammation biomarkers were increased after UUO and decreased by administration of ELA13. Furthermore, we found that the levels of essential molecules in the mothers against decapentaplegic (Smad) and extracellular signal-regulated kinase (ERK) pathways were reduced by ELA13 treatment in vivo and in vitro. In conclusion, ELA13 protected against kidney fibrosis through inhibiting the Smad and ERK signaling pathways and could thus be a promising candidate for anti-renal fibrosis treatment.

Stellera chamaejasme L. extract inhibits adipocyte differentiation through activation of the extracellular signal-regulated kinase pathway.

Stellera chamaejasme L. (SCL) is a perennial herb with demonstrated bioactivities against inflammation and metabolic dysfunction. Adipocyte differentiation is a critical regulator of metabolic homeostasis and a promising target for the treatment of metabolic diseases, so we examined the effects of SCL on adipogenesis. A methanol extract of SCL dose-dependently suppressed intracellular lipid accumulation in adipocyte precursors cultured under differentiation induction conditions and reduced expression of the adipogenic transcription factors PPARγ and C/EBPα as well as the downstream lipogenic genes fatty acid binding protein 4, adiponectin, fatty acid synthase, and stearoyl-CoA desaturase. The extract also promoted precursor cell proliferation and altered expression of the cell cycle regulators cyclin-dependent kinase 4, cyclin E, and cyclin D1. In addition, SCL extract stimulated extracellular signal-regulated kinase (ERK) phosphorylation, while pharmacological inhibition of ERK effectively blocked the inhibitory effects of SCL extract on preadipocyte differentiation. These results suggest that SCL extract contains bioactive compounds that can suppress adipogenesis through modulation of the ERK pathway.

Molecular docking studies for NPACT ligands for the treatment of melanoma skin cancer

Approximately 80% of deaths attributable to skin cancer are attributed to melanoma. The main reason for its life-threatening nature is its high tendency to metastasis. The outlook for melanoma patients with distal metastases is grim, as they have a median survival of only six months, despite the utilization of the most advanced treatments now available. The Extracellular signal-regulated kinase (ERK) pathway is the most frequently altered oncogene in melanoma. Phytochemicals are receiving significant recognition due to their minimal toxicity, affordable price, and widespread acceptance as dietary supplements. Preclinical investigations have revealed many cellular and molecular processes via which phytochemicals function in the prevention and treatment of metastatic melanoma.: In this study, we performed virtual screening of 464 phytoconstituents were obtained from the Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target (NPACT) database to identify novel ERK inhibitors.: Virtual screening carried out prediction of drug-likeness and molecular docking studies with 2OJG, protein target related to ERK pathway.: Nine compounds achieved better docking score as compared to co-crystallized ligand. The accuracy of the docking method was checked using re-docking. Picetannol and sulfurentin were identified as potential inhibitors with docking score of -9.2 and -8.2, respectively. These two phytoconstituents also found to be non-carcinogenic which was predicted using a free webtool, Swiss ADME.: Our finding suggests that Piceatannol has promising potential to be further explored as ERK-pathway inhibitor in treatment of melanoma

Lactate dehydrogenase A regulates tumor-macrophage symbiosis to promote glioblastoma progression

Abundant macrophage infiltration and altered tumor metabolism are two key hallmarks of glioblastoma. By screening a cluster of metabolic small-molecule compounds, we show that inhibiting glioblastoma cell glycolysis impairs macrophage migration and lactate dehydrogenase inhibitor stiripentol emerges as the top hit. Combined profiling and functional studies demonstrate that lactate dehydrogenase A (LDHA)-directed extracellular signal-regulated kinase (ERK) pathway activates yes-associated protein 1 (YAP1)/ signal transducer and activator of transcription 3 (STAT3) transcriptional co-activators in glioblastoma cells to upregulate C-C motif chemokine ligand 2 (CCL2) and CCL7, which recruit macrophages into the tumor microenvironment. Reciprocally, infiltrating macrophages produce LDHA-containing extracellular vesicles to promote glioblastoma cell glycolysis, proliferation, and survival. Genetic and pharmacological inhibition of LDHA-mediated tumor-macrophage symbiosis markedly suppresses tumor progression and macrophage infiltration in glioblastoma mouse models. Analysis of tumor and plasma samples of glioblastoma patients confirms that LDHA and its downstream signals are potential biomarkers correlating positively with macrophage density. Thus, LDHA-mediated tumor-macrophage symbiosis provides therapeutic targets for glioblastoma.

Angiogenic responses are enhanced by recombinant human erythropoietin in a model of periventricular white matter damage of neonatal rats through EPOR-ERK1 signaling.

Recombinant human erythropoietin (rh-EPO) has been shown to stimulate neurogenesis and angiogenesis, both of which play crucial roles in the repair of brain injuries. Previously, we observed that rh-EPO treatment effectively reduced brain damage and enhanced angiogenesis in a neonatal rat model of periventricular white matter damage (PWMD). The objective of this research is to investigate the specific mechanism through which rh-EPO regulates angiogenesis following PWMD in premature neonates. We conducted experiments utilizing a neonatal PWMD model. Following rh-EPO treatment, the levels of erythropoietin receptor (EPOR) were found to be increased in the damaged brain of rats. Although the total amount of extracellular signal-regulated kinase (ERK), a downstream protein in the EPO signaling pathway, remained unchanged, there was clear upregulation of phosphorylated ERK1 (p-ERK1) levels. The increase in levels of p-ERK1 was inhibited by an ERK kinase inhibitor, while the total amount of ERK remained unchanged. Conversely, the levels of EPOR were not affected by the inhibitor. Notably, the introduction of rh-EPO led to a significant increase in the frequency of angiogenesis-related cells and the expression levels of angiogenic factors. However, these effects were nullified when the ERK pathway was blocked. These findings indicate that rh-EPO enhances angiogenic responses through the EPOR-ERK1 pathway in a neonatal PWMD model.

Homeobox Protein BarH-like 1 Promotes Gastric Cancer Progression by Activating Coiled-Coil Domain-Containing Protein 178.

Coiled-coil domain-containing protein 178 (CCDC178) has been revealed to exert metastasis-promoting properties in hepatocellular carcinoma, whereas its function in gastric cancer (GC) has not been fully understood. We evaluated its role in GC and the molecular mechanism. The differentially expressed genes in datasets related to GC metastasis were intersected with survival-related genes in GC, followed by prognostic significance prediction. Loss- and gain-of-function assays were conducted to examine the involvement of CCDC178, Homeobox protein BarH-like 1 (BARX1), and the extracellular signal-regulated kinase (ERK) pathway in GC cell malignant phenotype and the polarization of tumor-associated macrophages (TAM). The corresponding functions were verified in the in vivo animal experiment. High CCDC178 expression predicted a poor prognosis for GC patients, and CCDC178 correlated significantly with macrophage infiltration in GC tissues. CCDC178 activated the ERK pathway in GC. Silencing of CCDC178 reduced the colony formation, migratory and invasive potential of GC cells, and the M2-like polarization of TAM, which was reversed by TBHQ (an ERK activator). BARX1 bound to the promoter region of CCDC178, thus inducing its transcriptional level. Silencing of BARX1 suppressed the M2-type polarization of TAM in vitro and in vivo, and CCDC178 mitigated the repressing role of BARX1 knockdown. BARX1 activates the transcription of CCDC178 to induce the ERK pathway, thereby supporting macrophage recruitment and M2-like polarization in GC.

MCM6 Inhibits Decidualization via Cross-Talking with ERK Pathway in Human Endometrial Stromal Cells.

Decidualization plays an important role in the implantation of the embryo, but the molecular action implicated in this process is not completely known. Herein, we found that, compared with the proliferative endometrial tissues, the expression of minichromosome maintenance complex component 6 (MCM6) was markedly decreased in the secretory endometrial tissues. To verify the function of MCM6 in decidualization, in vitro decidualization model was constructed by treating human endometrial stromal cells (HESCs) with estrogen (E2) and progesterone (P4). Consistently, MCM6 level was downregulated in E2P4-treated HESCs. Administration of E2P4 accumulated HESCs in G1 cell cycle phase, leading to cell growth suppression. Ectopic expression of MCM6 promoted the transition of G1/S and restored the proliferation of HESCs that were inhibited by E2P4. MCM6 overexpression led to aberrant activation of extracellular signal-regulated kinase (ERK) and treatment with ERK agonist Ro 67-7476 restored MCM6 expression and cell proliferation inhibited by E2P4. Our data suggested that MCM6/ERK feedback loop plays a negative role in E2P4-induced decidualization and implies that MCM6 may be a promising target for meliorating uterine receptivity.

Silencing of secreted phosphoprotein 1 attenuates sciatic nerve injury-induced neuropathic pain: Regulating extracellular signal-regulated kinase and neuroinflammatory signaling pathways.

Neuropathic pain (NP) is a chronic pathological pain that affects the quality of life and is a huge medical burden for affected patients. In this study, we aimed to explore the effects of secreted phosphoprotein 1 (SPP1) on NP. We established a chronic constriction injury (CCI) rat model, knocked down SPP1 via an intrathecal injection, and/or activated the extracellular signal-regulated kinase (ERK) pathway with insulin-like growth factor 1 (IGF-1) treatment. Pain behaviors, including paw withdrawal threshold (PWT), paw withdrawal latency (PWL), lifting number, and frequency, were assessed. After sacrificing rats, the L4-L5 dorsal root ganglion was collected. Then, SPP1 levels were determined using quantitative polymerase chain reaction (qPCR) and western blot analysis. The levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, IL-10, epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β were determined using qPCR and enzyme-linked immunosorbent assay. The levels of ERK pathway factors were determined via western blot analysis. We found that CCI decreased PWT and PWL, increased the lifting number and frequency, and upregulated SPP1 levels. The loss of SPP1 reversed these CCI-induced effects. Additionally, CCI upregulated IL-1β, TNF-α, IL-6, EGF, and VEGF levels, downregulated TGF-β levels, and activated the ERK pathway, while silencing of SPP1 abrogated these CCI-induced effects. Moreover, IGF-1 treatment reversed the effects of SPP1 loss. The data indicate that silencing SPP1 attenuates NP via inactivation of the ERK pathway, suggesting that SPP1 may be a promising target for NP treatment.