The Neuroprotective Effect of Erythropoietin on the Optic Nerve and Spinal Cord in Rats with Experimental Autoimmune Encephalomyelitis through the Activation of the Extracellular Signal-Regulated Kinase 1/2 Signaling Pathway.

Experimental autoimmune encephalomyelitis is a demyelinating disease that causes paralysis in laboratory rats. This condition lacks treatment that reverses damage to the myelin sheaths of neuronal cells. Therefore, in this study, treatment with EPO as a neuroprotective effect was established to evaluate the ERK 1/2 signaling pathway and its participation in the EAE model. EPO was administered in 5000 U/Kg Sprague Dawley rats. U0126 was used as an inhibitor of the ERK 1/2 pathway to demonstrate the possible activation of this pathway in the model. Spinal cord and optic nerve tissues were evaluated using staining techniques such as H&E and the Luxol Fast Blue myelin-specific technique, as well as immunohistochemistry of the ERK 1/2 protein. The EPO-treated groups showed a decrease in cellular sampling in the spinal cord tissues but mainly in the optic nerve, as well as an increase in the expression of the ERK 1/2 protein in both tissues. The findings of this study suggest that EPO treatment reduces cellular death in EAE-induced rats by regulating the ERK pathway.

SIK2: A Novel Negative Feedback Regulator of FGF2 Signaling.

A wide range of cells respond to fibroblast growth factor 2 (FGF2) by proliferation via activation of the Ras/ERK1/2 pathway. In this study, the potential involvement of salt inducible kinase SIK2) in this cascade within retinal Müller glia is explored. It is found that SIK2 phosphorylation status and activity are modulated in an FGF2-dependent manner, possibly via ERK1/2. With SIK2 downregulation, enhanced ERK1/2 activation with delayed attenuation and increased cell proliferation is observed, while SIK2 overexpression hampers FGF2-dependent ERK1/2 activation. In vitro kinase and site-directed mutagenesis studies indicate that SIK2 targets the pathway element GRB2-associated-binding protein 1 (Gab1) on Ser266. This phosphorylation event weakens Gab1 interactions with its partners growth factor receptor-bound protein 2 (Grb2) and Src homology region 2 domain containing phosphatase 2 (Shp2). Collectively, these results suggest that during FGF2-dependent proliferation process ERK1/2-mediated activation of SIK2 targets Gab1, resulting in downregulation of the Ras/ERK1/2 cascade in a feedback loop.

FASN promotes anoikis resistance in colorectal liver metastases through the ERK1/2 pathway.

PURPOSE: Colorectal cancer (CRC) is recognized as the third most common form of malignancy, with the liver frequently serving as the main site for metastasis. Anoikis resistance (AR) is critical in colorectal cancer liver metastases (CRLM). Fatty acid synthase (FASN), essential in lipid synthesis, mediates AR in many cancers. The present research examines the function of FASN in ERK1/2-mediated AR in CRLM and evaluates its therapeutic potential. METHODS: We performed scratch and migration experiment to evaluate the migration capacity of the LoVo cells. Flow cytometry was employed to identify cell apoptosis. The levels of FASN, p-ERK1/2, and proteins related to apoptosis was analyzed by Western blot. The mRNA level of FASN was determined by q-PCR after FASN silencing. In addition, we used an intrasplenic liver metastasis model of nude to assess the effect of FASN on CRLM. RESULTS: In vitro experiments showed that after FASN silencing, the cell apoptosis rate was increased, migration capability was notably decreased, the expression of p-ERK1/2, the proteins related to anti-apoptotic were significantly decreased, and the proteins related to apoptosis were significantly increased. In vivo experiments showed that AR significantly increased the number of liver metastatic foci, whereas FASN silencing significantly inhibited CRLM. CONCLUSION: These results suggest that FASN silencing suppressed AR through the ERK 1/2 pathway, which in turn suppressed CRLM.

PM10 exposure induces bronchial hyperresponsiveness by upreguating acetylcholine muscarinic 3 receptor.

Exposure to particulate matter (PM10) can induce respiratory diseases that are closely related to bronchial hyperresponsiveness. However, the involved mechanism remains to be fully elucidated. This study aimed to demonstrate the effects of PM10 on the acetylcholine muscarinic 3 receptor (CHRM3) expression and the role of the ERK1/2 pathway in rat bronchial smooth muscle. A whole-body PM10 exposure system was used to stimulate bronchial hyperresponsiveness in rats for 2 and 4 months, accompanied by MEK1/2 inhibitor U0126 injection. The whole-body plethysmography system and myography were used to detect the pulmonary and bronchoconstrictor function, respectively. The mRNA and protein levels were determined by Western blotting, qPCR, and immunofluorescence. Enzyme-linked immunosorbent assay was used to detect the inflammatory cytokines. Compared with the filtered air group, 4 months of PM10 exposure significantly increased CHRM3-mediated pulmonary function and bronchial constriction, elevated CHRM3 mRNA and protein expression levels on bronchial smooth muscle, then induced bronchial hyperreactivity. Additionally, 4 months of PM10 exposure caused an increase in ERK1/2 phosphorylation and increased the secretion of inflammatory factors in bronchoalveolar lavage fluid. Treatment with the MEK1/2 inhibitor, U0126 inhibited the PM10 exposure-induced phosphorylation of the ERK1/2 pathway, thereby reducing the PM10 exposure-induced upregulation of CHRM3 in bronchial smooth muscle and CHRM3-mediated bronchoconstriction. U0126 could rescue PM10 exposure-induced pathological changes in the bronchus. In conclusion, PM10 exposure can induce bronchial hyperresponsiveness in rats by upregulating CHRM3, and the ERK1/2 pathway may be involved in this process. These findings could reveal a potential therapeutic target for air pollution induced respiratory diseases.

Quercetin inhibits chronic stress-mediated progression of triple-negative breast cancer by blocking ß2-AR/ERK1/2 pathway.

Chronic stress-mediated sustained release of neurotransmitters, which ultimately leads to the activation of ß2-adrenergic receptor (ß2-AR) signaling, is one of the most important reasons for triple-negative breast cancer (TBNC) progression. Quercetin (Que) has been proven to have the advantage of ameliorating stress psychological disorder. Our present study aimed to investigate the effect of Que on tumor growth and metastasis in TNBC xenograft mice undergoing stress, and to explore its underlying mechanisms. We first evaluated the effect of Que on the progression of TNBC in nude mice in vivo. The results showed that, Que could inhibit chronic stress-induced TNBC growth and occurrence of lung metastasis. We subsequently employed epinephrine (E) as a representative of stress hormone to investigate its possible mechanism in vitro. The results showed that, Que could inhibit E-mediated proliferation and migration of TNBC cells by blocking ß2-AR/ERK1/2 pathway. In conclusion, our data demonstrated that Que could inhibit chronic stress-induced ERK1/2 activity in TNBC cells, and thereby weakening the potential for TNBC growth and metastasis.

Hypomethylation of the LncRNA H19 promoter accelerates osteogenic differentiation of vascular smooth muscle cells by activating the Erk1/2 pathways.

OBJECTIVE: Vascular calcification is a common chronic kidney disease complication. This study aimed to investigate the function of long non-coding RNA (LncRNA) H19 in vascular calcification to explore new therapeutic strategies. METHODS: We induced osteogenic differentiation and calcification of vascular smooth muscle cells (VSMCs) using ß-glycerophosphate. Then, we detected the LncRNA H19 promoter methylation status and Erk1/2 pathways using methylation-specific polymerase chain reaction and western blotting, respectively. RESULTS: Compared with the control group, high phosphorus levels induced VSMC calcification, accompanied by increases in LncRNA H19 and the osteogenic marker Runx2 and reduction of the contractile phenotype marker SM22a. LncRNA H19 knockdown inhibited osteogenic differentiation and calcification of VSMCs. However, the suppressed role of VSMC calcification caused by shRNA H19 was partially reversed by simultaneous activation of the Erk1/2 pathways. Mechanically, we found that the methylation rate of CpG islands in the LncRNA H19 promoter region was significantly lower in the high-phosphorus group, and the hypomethylation state elevated LncRNA H19 levels, which in turn regulated phosphorylated Erk1/2 expression. CONCLUSIONS: LncRNA H19 promoted osteogenic differentiation and calcification of VSMCs by regulating the Erk1/2 pathways. Additionally, hypomethylation of LncRNA H19 promoter CpG islands upregulated LncRNA H19 levels and subsequently activated Erk1/2 phosphorylation.

The Influence of IL-11 on Cardiac Fibrosis in Experimental Models: A Systematic Review.

Fibrosis is one of the main factors that impair the function of many organs. In the heart, fibrosis leads to contractile dysfunction and arrhythmias, which are important in the development of heart failure. Interleukin (IL)-11 is regulated in various heart diseases and has recently been reported to be an important cytokine in fibrosis in this organ. However, this topic has been little explored, and many questions persist. Thus, this systematic review aimed to report on possible IL-11 therapies evaluated in rodent model-induced cardiac fibrosis. Inclusion criteria were experimental in vivo studies that used different rodent models for cardiac fibrosis associated with IL-11 interventions, without year and language restrictions. The search in PubMed, Web of Science, and Embase databases was performed in October 2022. The risk of bias assessment of the studies was based on the guidelines of the SYRCLE tool, and data from the selected articles were also presented in a table as a narrative description. This review was based on eight studies in which five different interventions were used: recombinant human IL-11 (rhIL-11), anti-IL11 (X203), recombinant mouse IL-11 (rmIL-11), lentivirus (LV)-IL-11 + lutein, and anti-IL11RA (X209). Based on the included studies, the results were variable, with IL-11 overexpression inducing cardiac fibrosis, while inhibition protected against this process, preserving the function of this organ. Therefore, IL-11 stands out as a promising therapeutic target for cardiac fibrosis. However, further studies are needed to understand the mechanisms triggered by each treatment, as well as its safety and immunogenicity.

GPNMB promotes peripheral nerve regeneration by activating the Erk1/2 and Akt pathways via binding Na+/K+-ATPase α1 in Schwann cells.

Glycoprotein non-metastatic melanoma protein B (GPNMB) is ubiquitously expressed and has protective effects on the central nervous system. In particular, it is also expressed in the peripheral nervous system (PNS) and upregulated after peripheral nerve injury. However, the role and underlying mechanism of GPNMB in the PNS, especially in peripheral nerve regeneration (PNR), are still unknown and need to be further investigated. In this study, recombinant human GPNMB (rhGPNMB) was injected into a sciatic nerve injury model. It was found that rhGPNMB facilitated the regeneration and functional recovery of the injured sciatic nerve in vivo. Moreover, it was also confirmed that GPNMB activated the Erk1/2 and Akt pathways via binding with Na+/K + -ATPase α1 (NKA α1) and promoted the proliferation and migration of Schwann cells (SCs) and their expression and secretion of neurotrophic factors and neural adhesion molecules in vitro. Our findings demonstrate that GPNMB facilitates PNR through activation of the Erk1/2 and Akt pathways in SCs by binding with NKA α1 and may be a novel strategy for PNR.

Static electric field (SEF) exposure promotes the proliferation of B lymphocytes.

With the rapid development of ultra-high voltage direct current (UHV DC) transmission technology, the intensity of electric fields in the surrounding environment of UHV DC transmission lines significantly increased, which raised public concerns about the potential health effects of electric fields. Previous studies have shown that the exposure of electromagnetic field was associated with cancer. B lymphocytes can produce autoantibodies and tumor growth factors through proliferation, which contributes to the development of cancer. Therefore, this study explored the effect and mechanism of static electric field (SEF) generated by DC transmission lines on the proliferation levels of B lymphocytes. Male mice were exposed to SEF. After the exposure of 7 and 14 days, the proliferation levels of B lymphocytes in the spleens of mice were measured, respectively. To validate biological effect discovered in animal experiments and elucidate the mechanism of the effect from the perspective of signaling pathways, lymphocytes were exposed to SEF. After the exposure of 24, 48 or 72 h, the proliferation levels of B lymphocytes, the expression levels of key proteins and cell cycle were determined. This study found that SEF exposure activated NF-κB pathway by stimulating ERK1/2 pathway and promoted B lymphocytes to enter S phase from G0/G1 phase. Meanwhile, SEF exposure also promoted B lymphocytes to enter G2 phase. Namely, SEF exposure significantly promoted the proliferation of B lymphocytes. This discovery provided theoretical and practical support for the prevention or application of negative or positive effects caused by SEF exposure and provided directions for future research.

Knockdown of PAF1 reduces cervical cancer cell proliferation, migration and invasion via retarding FLOT2-mediated MEK/ERK1/2 pathway.

Cervical cancer (CC) is a very usual reproductive malignant tumor in women. RNA polymerase II-associated factor 1 (PAF1) and flotillin-2 (FLOT2) both have been discovered to key participators in cancers' progression. However, the effects of PAF1/FLOT2 axis on CC development have not been probed. In this study, PAF1 and FLOT2 exhibited higher expression, and silencing of PAF1 down-regulated FLOT2 expression in CC. In addition, the regulatory effects of PAF1 suppression on CC progression were reversed after FLOT2 overexpression. Next, inhibition of PAF1 slowed the tumor growth in vivo through modulating FLOT2. Besides, down-regulation of PAF1 reduced FLOT2 expression to retard the MEK/ERK1/2 pathway. In conclusion, knockdown of PAF1 suppressed CC progression via retarding FLOT2-mediated MEK/ERK1/2 pathway. Our findings illustrated that the PAF1/FLOT2 axis may be useful bio-targets for CC treatment.

Glutathione Peroxidase 3 induced mitochondria-mediated apoptosis via AMPK /ERK1/2 pathway and resisted autophagy-related ferroptosis via AMPK/mTOR pathway in hyperplastic prostate.

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common disease in elderly men, mainly resulted from an imbalance between cell proliferation and death. Glutathione peroxidase 3 (GPX3) was one of the differentially expressed genes in BPH identified by transcriptome sequencing of 5 hyperplastic and 3 normal prostate specimens, which had not been elucidated in the prostate. This study aimed to ascertain the mechanism of GPX3 involved in cell proliferation, apoptosis, autophagy and ferroptosis in BPH. METHODS: Human prostate tissues, GPX3 silencing and overexpression prostate cell (BPH-1 and WPMY-1) models and testosterone-induced rat BPH (T-BPH) model were utilized. The qRT-PCR, CCK8 assay, flow cytometry, Western blotting, immunofluorescence, hematoxylin and eosin, masson's trichrome, immunohistochemical staining and transmission electron microscopy analysis were performed during in vivo and in vitro experiments. RESULTS: Our study indicated that GPX3 was localized both in the stroma and epithelium of prostate, and down-regulated in BPH samples. Overexpression of GPX3 inhibited AMPK and activated ERK1/2 pathway, thereby inducing mitochondria-dependent apoptosis and G0/G1 phase arrest, which could be significantly reversed by MEK1/2 inhibitor U0126 preconditioning. Moreover, overexpression of GPX3 further exerted anti-autophagy by inhibiting AMPK/m-TOR and up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4, mitochondrial GPX4 and cytoplasmic GPX4) to antagonize autophagy-related ferroptosis. Consistently, GPX3 deficiency generated opposite changes in both cell lines. Finally, T-BPH rat model was treated with GPX3 indirect agonist troglitazone (TRO) or GPX4 inhibitor RAS-selective lethal 3 (RSL3) or TRO plus RSL3. These treatments produced significant atrophy of the prostate and related molecular changes were similar to our in vitro observations. CONCLUSIONS: Our novel data manifested that GPX3, which was capable of inducing apoptosis via AMPK/ERK1/2 pathway and antagonizing autophagy-related ferroptosis through AMPK/m-TOR signalling, was a promising therapeutic target for BPH in the future.

The role of CREG1 in megakaryocyte maturation and thrombocytopoiesis.

Abnormal megakaryocyte maturation and platelet production lead to platelet-related diseases and impact the dynamic balance between hemostasis and bleeding. Cellular repressor of E1A-stimulated gene 1 (CREG1) is a glycoprotein that promotes tissue differentiation. However, its role in megakaryocytes remains unclear. In this study, we found that CREG1 protein is expressed in platelets and megakaryocytes and was decreased in the platelets of patients with thrombocytopenia. A cytosine arabinoside-induced thrombocytopenia mouse model was established, and the mRNA and protein expression levels of CREG1 were found to be reduced in megakaryocytes. We established megakaryocyte/platelet conditional knockout (Creg1pf4-cre) and transgenic mice (tg-Creg1). Compared to Creg1fl/fl mice, Creg1pf4-cre mice exhibited thrombocytopenia, which was mainly caused by inefficient bone marrow (BM) thrombocytopoiesis, but not by apoptosis of circulating platelets. Cultured Creg1pf4-cre-megakaryocytes exhibited impairment of the actin cytoskeleton, with less filamentous actin, significantly fewer proplatelets, and lower ploidy. CREG1 directly interacts with MEK1/2 and promotes MEK1/2 phosphorylation. Thus, our study uncovered the role of CREG1 in the regulation of megakaryocyte maturation and thrombopoiesis, and it provides a possible theoretical basis for the prevention and treatment of thrombocytopenia.

SH3 domain-binding kinase 1 promotes proliferation and inhibits apoptosis of cervical cancer via activating the Wnt/ß-catenin and Raf/ERK1/2 signaling pathways.

SH3 domain-binding kinase 1 (SBK1), is a member of the serine/threonine protein kinases family, and was confirmed to be upregulated in cervical cancer in our previous study. Nonetheless, the role of SBK1 in regulating cancer occurrence and development is unclear. In this study, the stable SBK1-knockdown and -overexpressed cell models were constructed by plasmid transfection technology. Cell viability and growth were assessed through CCK-8, colony formation, and BrdU methods. Cell cycle and apoptosis were analyzed by flow cytometry. The JC-1 staining assay was used to explore mitochondrial membrane potential. The scratch and Transwell assays were used to evaluate the cell metastatic ability. The nude mice models were utilized to explore the SBK1 expression affecting tumor growth in vivo. Our research indicated a high expression of SBK1 both in tissues and cells of cervical cancer. The proliferative, migratory, as well as invasive capacities of cervical cancer cells, were suppressed, and apoptosis was enhanced after SBK1 silence, whereas SBK1 upregulation led to opposite results. In addition, Wnt/ß-catenin and Raf/ERK1/2 pathways were activated by SBK1 upregulation. Furthermore, downregulation of c-Raf or ß-catenin, reversed the proliferation promotion and apoptosis inhibition effects in SBK1-overexpressed cells. The same results were observed with the use of the specific Raf inhibitor. SBK1 overexpression also contributed to tumor growth in vivo. Overall, SBK1 played a vital role in cervical tumorigenesis via activating the Wnt/ß-catenin and Raf/ERK1/2 pathways.

GRM2 Regulates Functional Integration of Adult-Born DGCs by Paradoxically Modulating MEK/ERK1/2 Pathway.

Metabotropic glutamate receptor 2 (GRM2) is highly expressed in hippocampal dentate granule cells (DGCs), regulating synaptic transmission and hippocampal functions. Newborn DGCs are continuously generated throughout life and express GRM2 when they are mature. However, it remained unclear whether and how GRM2 regulates the development and integration of these newborn neurons. We discovered that the expression of GRM2 in adult-born DGCs increased with neuronal development in mice of both sexes. Lack of GRM2 caused developmental defects of DGCs and impaired hippocampus-dependent cognitive functions. Intriguingly, our data showed that knockdown of Grm2 resulted in decreased b/c-Raf kinases and paradoxically led to an excessive activation of MEK/ERK1/2 pathway. Inhibition of MEK ameliorated the developmental defects caused by Grm2 knockdown. Together, our results indicate that GRM2 is necessary for the development and functional integration of newborn DGCs in the adult hippocampus through regulating the phosphorylation and activation state of MEK/ERK1/2 pathway.SIGNIFICANCE STATEMENT Metabotropic glutamate receptor 2 (GRM2) is highly expressed in mature dentate granule cells (DGCs) in the hippocampus. It remains unclear whether GRM2 is required for the development and integration of adult-born DGCs. We provided in vivo and in vitro evidence to show that GRM2 regulates the development of adult-born DGCs and their integration into existing hippocampal circuits. Lack of GRM2 in a cohort of newborn DGCs impaired object-to-location memory in mice. Moreover, we revealed that GRM2 knockdown paradoxically upregulated MEK/ERK1/2 pathway by suppressing b/c-Raf in developing neurons, which is likely a common mechanism underlying the regulation of the development of neurons expressing GRM2. Thus, Raf/MEK/ERK1/2 pathway could be a potential target for brain diseases related to GRM2 abnormality.

[Exploring the treatment of sepsis-associated acute lung injury with Liangge Powder via ERK1/2 and PI3K/AKT pathways: based on network pharmacology and whole animal experimentation].

Objective: To investigate the therapeutic effect and mechanism of Liangge Powder against sepsis-induced acute lung injury (ALI) . Methods: From April to December 2021, the key components of Liangge Powder and its targets against sepsis-induced ALI were analyzed by network pharmacology, and to enrich for relevant signaling pathways. A total of 90 male Sprague-Dawley rats were randomly assigned to sham-operated group, sepsis-induced ALI model group (model group), Liangge Powder low, medium and high dose group, ten rats in the sham-operated group and 20 rats in each of the remaining four groups. Sepsis-induced ALI model was established by cecal ligation and puncture. Sham-operated group: gavage with 2 ml saline and no surgical treatment. Model group: surgery was performed and 2 ml saline was gavaged. Liangge Powder low, medium and high dose groups: surgery and gavage of Liangge Powder 3.9, 7.8 and 15.6 g/kg, respectively. To measure the wet/dry mass ratio of rats lung tissue and evaluate the permeability of alveolar capillary barrier. Lung tissue were stained with hematoxylin and eosin for histomorphological analysis. The levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL) -6 and IL-1ß in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay. The relative protein expression levels of p-phosphatidylinositol 3-kinase (PI3K), p-protein kinase B (AKT), and p-ertracellular regulated protein kinases (ERK) were detected via Western blot analysis. Results: Network pharmacology analysis indicated that 177 active compounds of Liangge Powder were selected. A total of 88 potential targets of Liangge Powder on sepsis-induced ALI were identified. 354 GO terms of Liangge Powder on sepsis-induced ALI and 108 pathways were identified using GO and KEGG analysis. PI3K/AKT signaling pathway was recognized to play an important role for Liangge Powder against sepsis-induced ALI. Compared with the sham-operated group, the lung tissue wet/dry weight ratio of rats in the model group (6.35±0.95) was increased (P<0.001). HE staining showed the destruction of normal structure of lung tissue. The levels of IL-6 [ (392.36±66.83) pg/ml], IL-1ß [ (137.11±26.83) pg/ml] and TNF-α [ (238.34±59.36) pg/ml] were increased in the BALF (P<0.001, =0.001, <0.001), and the expression levels of p-PI3K, p-AKT and p-ERK1/2 proteins (1.04±0.15, 0.51±0.04, 2.31±0.41) were increased in lung tissue (P=0.002, 0.003, 0.005). The lung histopathological changes were reduced in each dose group of Liangge Powder compared with the model group. Compared with the model group, the wet/dry weight ratio of lung tissue (4.29±1.26) was reduced in the Liangge Powder medium dose group (P=0.019). TNF-α level [ (147.85±39.05) pg/ml] was reduced (P=0.022), and the relative protein expression levels of p-PI3K (0.37±0.18) and p-ERK1/2 (1.36±0.07) were reduced (P=0.008, 0.017). The wet/dry weight ratio of lung tissue (4.16±0.66) was reduced in the high-dose group (P=0.003). Levels of IL-6, IL-1ß and TNF-α[ (187.98±53.28) pg/ml, (92.45±25.39) pg/ml, (129.77±55.94) pg/ml] were reduced (P=0.001, 0.027, 0.018), and relative protein expression levels of p-PI3K, p-AKT and p-ERK1/2 (0.65±0.05, 0.31±0.08, 1.30±0.12) were reduced (P=0.013, 0.018, 0.015) . Conclusion: Liangge Powder has therapeutic effects in rats with sepsis-induced ALI, and the mechanism may be related to the inhibition of ERK1/2 and PI3K/AKT pathway activation in lung tissue.

Prepubertal exposure to copper oxide nanoparticles induces Leydig cell injury with steroidogenesis disorders in mouse testes.

Copper oxide nanoparticles (CuONPs) are metallic multifunctional nanoparticles with good conductive, catalytic and antibacterial characteristics that have shown to cause reproductive dysfunction. However, the toxic effect and potential mechanisms of prepubertal exposure to CuONPs on male testicular development have not been clarified. In this study, healthy male C57BL/6 mice received 0, 10, and 25 mg/kg/d CuONPs by oral gavage for 2 weeks (postnatal day 22-35). The testicular weight was decreased, testicular histology was disturbed and the number of Leydig cells was reduced in all CuONPs-exposure groups. Transcriptome profiling suggested steroidogenesis was impaired after exposure to CuONPs. The steroidogenesis-related genes mRNA expression level, concentration of serum steroids hormones and the HSD17B3-, STAR- and CYP11A1-positive Leydig cell numbers were dramatically reduced. In vitro, we exposed TM3 Leydig cells to CuONPs. Bioinformatic analysis, flow cytometry analysis and western blotting analysis confirmed that CuONPs can dramatically reduce Leydig cells viability, enhance apoptosis, trigger cell cycle arrest and reduce cell testosterone levels. U0126 (ERK1/2 inhibitor) significantly reversed TM3 Leydig cells injury and testosterone level decrease induced by CuONPs. These outcomes indicate that CuONPs exposure activates the ERK1/2 signaling pathway, which further promotes apoptosis and cell cycle arrest in TM3 Leydig cells, and ultimately leads to Leydig cells injury and steroidogenesis disorders.

CCL21/CCR7 Axis Contributes to Trophoblastic Cell Migration and Invasion in Preeclampsia by Affecting the Epithelial Mesenchymal Transition via the ERK1/2 Signaling Pathway.

Preeclampsia (PE) is a pregnancy-related disorder that is a leading cause of maternal death. The failure of spiral artery remodeling due to insufficient trophoblast migration and invasion is critical in the pathogenesis of PE. Recently, the CC motif chemokine ligand 21 (CCL21) has been widely linked to cancer cell invasion and migration. However, their potential mechanisms are still unknown. In this study, we found that CCL21 expression was significantly lower in the PE group than that in the control group. In vitro experiments revealed that recombinant CCL21 could promote trophoblast cell epithelial-to-mesenchymal transitions (EMTs) and improve migration and invasion. Furthermore, an inhibitor of the ERK1/2 signaling pathway inhibited the CCL21-induced EMT process. Finally, a PE mouse model was established using the NOS inhibitor L-NAME, and we obtained similar results, with downregulated CCL21 and EMT biomarkers and upregulated CCR7. Taken together, these findings suggest that the CCL21/CCR7 axis influences EMT by activating the ERK1/2 signaling pathway, thereby affecting trophoblast cell migration and invasion, which may play a crucial role in the pathogenesis of PE.

Elevated expression of myosin VI contributes to breast cancer progression via MAPK/ERK signaling pathway.

Breast cancer (BC) is one of the most common malignancies occurring in women worldwide, and its incidence is increasing each year. Accumulating evidence indicated that Myosin VI (MYO6) functions as a gene associated with tumor progression in several cancers. However, the potential role of MYO6 and its underlying mechanisms in the development and progression of BC remains unknown. Herein, we examined the expression levels of MYO6 in BC cells and tissues by western blot and immunohistochemistry. Loss- and gain-of-function investigations in vitro were performed to determine the biological functions of MYO6. And in vivo effects of MYO6 on tumorigenesis were investigated in nude mice. Our findings showed that the expression of MYO6 was up-regulated in breast cancer, and its high expression was correlated with poor prognosis. Further investigation exhibited that silencing the expression of MYO6 significantly inhibited cell proliferation, migration and invasion, whereas overexpression of MYO6 enhanced these abilities in vitro. Also, reduced expression of MYO6 significantly retarded the tumor growth in vivo. Mechanistically, Gene Set Enrichment Analysis (GSEA) revealed that MYO6 was involved in mitogen-activated protein kinase (MAPK) pathway. Moreover, we proved that MYO6 enhanced BC proliferation, migration and invasion via increasing the expression of phosphorylated ERK1/2. Taken together, our findings highlight the role of MYO6 in promoting BC cell progression through MAPK/ERK pathway, suggesting it may be a new potential therapeutic and prognostic target for BC patients.

Semaglutide inhibits ischemia/reperfusion-induced cardiomyocyte apoptosis through activating PKG/PKCε/ERK1/2 pathway.

Apoptosis is a major pathophysiological change following myocardial ischemia/reperfusion (I/R) injury. Glucagon-like peptide 1 (GLP-1) and its receptor GLP-1R are widely expressed in the cardiovascular system and GLP-1/GLP-1R activates the protein kinase G (PKG)-related signaling pathway. Therefore, this study tested whether semaglutide, a new GLP-1 analog, inhibits I/R injury-induced cardiomyocyte apoptosis by activating the PKG/PKCε/ERK1/2 pathway. We induced myocardial I/R injury in rats and hypoxia/reoxygenation (H/R) injury in H9C2 cells and detected the effects of semaglutide, a PKG analog (8-Br-cGMP), and a PKG inhibitor (KT-5823) on the PKG/PKCε/ERK1/2 pathway and cardiomyocyte apoptosis. We found that semaglutide upregulated GLP-1R levels, and both semaglutide and 8-Br-cGMP activated the PKG/PKCε/ERK1/2 pathway, inhibited myocardial infarction (MI), decreased hs-cTNT levels, increased NT-proBNP levels, and suppressed cardiomyocyte apoptosis in I/R rats and H/R H9C2 cells. However, KT-5823 exerted contrasting effects with semaglutide and 8-Br-cGMP, and KT-5823 weakened the cardioprotective effects of semaglutide. In conclusion, semaglutide inhibits I/R injury-induced cardiomyocyte apoptosis by activating the PKG/PKCε/ERK1/2 pathway. The beneficial effect of GLP-1/GLP-1R, involved in the activation of the PKG/PKCε/ERK1/2 pathway, may provide a novel treatment method for myocardial I/R injury.

MicroRNA-140-5p shuttled by microglia-derived extracellular vesicles attenuates subarachnoid hemorrhage-induced microglia activation and inflammatory response via MMD downregulation.

BACKGROUND: It is documented that microglia-secreted extracellular vesicles (microglia-EVs) exert neuroprotection which is important following subarachnoid hemorrhage (SAH). Herein, we focused on the mechanism of microglia-EVs harboring microRNA-140-5p (miR-140-5p) in SAH development. METHODS: After the successful establishment of SAH rats, neurological function was evaluated, and behaviors were observed. Serum inflammatory factors (IL-1ß and TNF-α) were quantified by ELISA, followed by the detection of microglial polarization by immunofluorescence. The relationship between miR-140-5p and monocyte to macrophage differentiation-associated (MMD) was evaluated using luciferase assay. Following the extraction of microglia and microglia-EVs, the transferring of miR-140-5p by microglia-EVs was assessed by co-culture experiments. SAH rats were treated with the EVs sourced from microglia overexpressing miR-140-5p (microglia-EVs-miR-140-5p) or EVs sourced from miR-140-5p-deficient microglia (microglia-EVs-miR-140-5p inhibitor) for in vivo effect assessment. RESULTS: Microglia-EVs inhibited microglia activation and secretion of TNF-α and IL-1ß by delivering miR-140-5p. Microglia-EVs could transmit miR-140-5p into microglia. Furthermore, microglia-EVs-miR-140-5p reduced the expression of its target MMD, resulting in blocked inflammatory response and activation of microglia in SAH rats by disrupting the PI3K/AKT and Erk1/2 signaling. CONCLUSION: In summary, microglia-EVs transmitted miR-140-5p into microglia to downregulate MMD and finally contributed to neuroprotection in SAH rats.