Overexpression SPRY2 Suppresses Esophageal Squamous Cell Carcinoma Progression Via Inactivation of ERK/AKT Signaling / La Sobreexpresión SPRY2 Suprime la Evolución del Carcinoma de Células Escamosas de Esófago Mediante la Inactivación de la Señalización ERK/AKT

SUMMARY: Esophageal cancer is one of the most aggressive gastrointestinal cancers. Invasion and metastasis are the main causes of poor prognosis of esophageal cancer. SPRY2 has been reported to exert promoting effects in human cancers, which controls signal pathways including PI3K/AKT and MAPKs. However, the expression of SPRY2 in esophageal squamous cell carcinoma (ESCC) and its underlying mechanism remain unclear. In the present study, we aimed to investigate the detailed role of SPRY2 in the regulation of cell proliferation, invasion and ERK/AKT signaling pathway in ESCC. It was identified that the expression level of SPRY2 in ESCC was remarkably decreased compared with normal tissues, and it was related to clinicopathologic features and prognosis ESCC patients. The upregulation of SPRY2 expression notably inhibited the proliferation, migration and invasion of Eca-109 cells. In addition, the activity of ERK /AKT signaling was also suppressed by the SPRY2 upregulation in Eca-109 cells. Our study suggests that overexpression of SPRY2 suppress cancer cell proliferation and invasion of by through suppression of the ERK/AKT signaling pathways in ESCC. Therefore, SPRY2 may be a promising prognostic marker and therapeutic target for ESCC.

El cáncer de esófago es uno de los cánceres gastrointestinales más agresivos. La invasión y la metástasis son las principales causas de mal pronóstico del cáncer de esófago. Se ha informado que SPRY2 ejerce efectos promotores en los cánceres humanos, que controla las vías de señales, incluidas PI3K/AKT y MAPK. Sin embargo, la expresión de SPRY2 en el carcinoma de células escamosas de esófago (ESCC) y su mecanismo subyacente aún no están claros. En el presente estudio, nuestro objetivo fue investigar el papel detallado de SPRY2 en la regulación de la proliferación celular, la invasión y la vía de señalización ERK/AKT en ESCC. Se identificó que el nivel de expresión de SPRY2 en ESCC estaba notablemente disminuido en comparación con los tejidos normales, y estaba relacionado con las características clínico-patológicas y el pronóstico de los pacientes con ESCC. La regulación positiva de la expresión de SPRY2 inhibió notablemente la proliferación, migración e invasión de células Eca-109. Además, la actividad de la señalización de ERK/AKT también fue suprimida por la regulación positiva de SPRY2 en las células Eca-109. Nuestro estudio sugiere que la sobreexpresión de SPRY2 suprime la proliferación y la invasión de células cancerosas mediante la supresión de las vías de señalización ERK/AKT en ESCC. Por lo tanto, SPRY2 puede ser un marcador de pronóstico prometedor y un objetivo terapéutico para la ESCC.

Effect of Guipitang on ERK1/2 and p38 MAPK in Rats with Myocardial Ischemia / 中国实验方剂学杂志

ObjectiveTo explore the therapeutic effect and mechanism of Guipitang on rats with myocardial ischemia. MethodFifty SD rats were divided into five groups： a control group， a model group， low and high-dose Guipitang （7.52， 15.04 g·kg-1） groups， and a trimetazidine group （0.002 g·kg-1）. By intragastric administration of vitamin D3 and feeding rats with high-fat forage and injecting isoproterenol， the rat model of myocardial ischemia was established. After drug treatment of 15 d， an electrocardiogram （ECG） was performed to analyze the degree of myocardial injury. A fully automatic biochemical analyzer was used to detect the changes in the serum levels of total cholesterol （TC）， high-density lipoprotein cholesterol （HDL-C）， triglyceride （TG）， and low-density lipoprotein cholesterol （LDL-C）. Hematoxylin-eosin （HE） staining and Masson staining were used to observe myocardial histopathological changes. TdT-mediated dUTP nick end labeling （TUNEL） staining was used to detect cardiomyocyte apoptosis. Western blot was adopted to detect the protein levels of extracellular signal-regulated kinase 1/2 （ERK1/2）， phospho-ERK1/2 （p-ERK1/2）， p38 mitogen-activated protein kinase （p38 MAPK）， phospho-p38 MAPK （p-p38 MAPK）， B-cell lymphoma-2 （Bcl-2）-associated X （Bax）， Bcl-2， and cleaved cysteine aspartate proteolytic enzyme （cleaved Caspase-3）. ResultCompared with the control group， the ECG S-T segment decreased in the model group. The serum levels of TC， TG， and LDL-C were increased significantly （P<0.05）. The arrangement of myocardial tissue was disordered， and the proportion of cardiomyocyte apoptosis increased. The protein levels of cleaved Caspase-3， Bax， and p-p38 MAPK in the heart were increased， and the Bcl-2 expression was decreased （P<0.05）. Compared with the model group， the S-T segment downward shift was restored in the low and high-dose Guipitang groups and trimetazidine group， and the levels of TC， TG， and LDL-C were decreased. The protein expression of cleaved Caspase-3 and Bax in the heart dropped， and p-p38 MAPK and p-ERK1/2 protein expressions increased significantly （P<0.05）. The degree of myocardial injury was alleviated， and the proportion of cardiomyocyte apoptosis decreased. Bcl-2 protein expression was increased significantly in the low-dose Guipitang group （P<0.05）. ERK1/2 and p38 MAPK proteins had no significant difference among different groups. ConclusionGuipitang could alleviate myocardial injury and inhibit cardiomyocyte apoptosis in rats by activating the expression of ERK1/2 and p38 MAPK.

Protective Autophagy in 5-Fluorouracil-Resistant Colorectal Cancer Cells and ERK-RSK-ABCG2 Linkage / Autofagia Protectora en Células de Cáncer Colorrectal Resistentes al 5-Fluorouracilo y Enlace ERK-RSK-ABCG2

SUMMARY: To evaluate the anti-cancer effects of yeast extract on resistant cells, autophagy and necroptosis were investigated in 5-fluorouracil (5-FU)-resistant colorectal cancer cells. Further underlying characteristics on drug resistance were evaluated, focused on ERK-RSK-ABCG2 linkage. SNU-C5 and 5-FU resistant SNU-C5 (SNU-C5/5-FUR) colorectal cancer cells were adopted for cell viability assay and Western blotting to examine the anti-cancer effects of yeast extract. Yeast extract induced autophagy in SNU-C5 cells with increased Atg7, Atg12-5 complex, Atg16L1, and LC3 activation (LC3-II/LC3-I), but little effects in SNU-C5/5-FUR cells with increased Atg12-5 complex and Atg16L1. Both colorectal cancer cells did not show necroptosis after yeast extract treatment. Based on increased ABCG2 and RSK expression after yeast extract treatment, drug resistance mechanisms were further evaluated. As compared to wild type, SNU-C5/5-FUR cells showed more ABCG2 expression, less RSK expression, and less phosphorylation of ERK. ABCG2 inhibitor, Ko143, treatment induces following changes: 1) more sensitivity at 500 mM 5-FU, 2) augmented proliferation, and 3) less phosphorylation of ERK. These results suggest that protective autophagy in SNU-C5/5-FUR cells with increased ABCG2 expression might be candidate mechanisms for drug resistance. As the ERK responses were different from each stimulus, the feasible mechanisms among ERK-RSK-ABCG2 should be further investigated in 5-FU-resistant CRC cells.

Para evaluar los efectos anticancerígenos del extracto de levadura en células resistentes, se investigaron la autofagia y la necroptosis en células de cáncer colorrectal resistentes al 5-fluorouracilo (5-FU). Además se evaluaron otras características subyacentes de la resistencia a los medicamentos centrándose en el enlace ERK-RSK-ABCG2. Se usaron células de cáncer colorrectal SNU-C5 (SNU-C5/5-FUR) resistentes a SNU-C5 y 5- FU para el ensayo de viabilidad celular y la transferencia Western para examinar los efectos anticancerígenos del extracto de levadura. El extracto de levadura indujo autofagia en células SNU-C5 con mayor activación de Atg7, complejo Atg12-5, Atg16L1 y LC3 (LC3-II/LC3-I), pero pocos efectos en células SNU-C5/5-FUR con aumento de Atg12-5 complejo y Atg16L1. Ambas células de cáncer colorrectal no mostraron necroptosis después del tratamiento con extracto de levadura. Se evaluaron los mecanismos de resistencia a los medicamentos. en base al aumento de la expresión de ABCG2 y RSK después del tratamiento con extracto de levadura.En comparación con las de tipo salvaje, las células SNU-C5/5-FUR mostraron más expresión de ABCG2, menos expresión de RSK y menos fosforilación de ERK. El tratamiento con inhibidor de ABCG2, Ko143, induce los siguientes cambios: 1) más sensibilidad a 5-FU 500 mM, 2) proliferación aumentada y 3) menos fosforilación de ERK. Estos resultados sugieren que la autofagia protectora en células SNU-C5/5-FUR con mayor expresión de ABCG2 podría ser un mecanismo candidato para la resistencia a los medicamentos. Como las respuestas de ERK fueron diferentes de cada estímulo, los mecanismos factibles entre ERK-RSK- ABCG2 deberían investigarse más a fondo en células CCR resistentes a 5-FU.

Colorectal cancer cells induce the formation of cancer-associated fibroblasts by activating the ERK signaling pathway in fibroblasts / 南方医科大学学报

OBJECTIVE@#To investigate the mechanism by which conditioned medium of colorectal cancer cells promotes the formation of cancer-associated fibroblasts (CAFs).@*METHODS@#Normal human colorectal fibroblasts (CCD-18Co cells) in logarithmic growth phase were treated with the conditioned media of colorectal cancer HCT116 cells (HCT116-CM) or Caco-2 cells (Caco-2-CM) alone or in combination with 300 nmol/L ERK inhibitor SCH772984. The expression levels of CAFs-related molecular markers were detected in the treated cells with real-time quantitative PCR (RT- qPCR) and immunofluorescence assay, and the changes in cell proliferation, colony formation and migration were assessed with RTCA, colony formation and wound healing assays; Western blotting was performed to detect the activated signaling pathways in the fibroblasts and the changes in CAFs formation after blocking of the signaling pathway.@*RESULTS@#HCT116-CM and Caco-2-CM significantly upregulated mRNA expression levels of CAFs markers (including α-SMA, FAP, FN and TGF-β) in CCD-18Co cells, and strongly promoted fibroblast transformation into CAFs (P < 0.05). The two conditioned media also promoted the proliferation, colony formation and migration of CCD-18Co cells (P < 0.05) and significantly increased the levels of α-SMA protein and ERK phosphorylation in the cells (P < 0.05). The ERK inhibitor SCH772984 obviously inhibited the expression of α-SMA and the transformation of CCD-18Co cells into CAFs induced by the conditioned medium of colorectal cancer cells (P < 0.05).@*CONCLUSION@#Colorectal cancer cells may induce the formation of colorectal CAFs by activating the ERK pathway in the fibroblasts.

Acteoside Inhibits Epithelial Mesenchymal Transformation of Hepatoma Cells Through Regulation of ERK1/2 Signaling Pathway / 肿瘤防治研究

Objective To investigate the effect and mechanism of acteoside (ACT) in inhibiting epithelial-mesenchymal transition (EMT) in human hepatoma HCCLM3 cells by regulating the ERK1/2 pathway. Methods CCK-8 assay was used to detect the effect of hepatocellular carcinoma cell proliferation. The invasion and migration of HCC cells were detected by scratch and Transwell tests. The mRNA and protein expression levels of the ERK1/2 signaling pathway and EMT-related genes (E-cadherin and N-cadherin) were detected by real-time PCR and Western blot analyses. Results ACT reduced the activity of HCCLM3 cells and inhibited the proliferation of HCC cells, and the effects had certain correlation with drug concentration and time. ACT inhibited the migration and invasion process of HCCLM3 cells in a concentration-dependent manner. ACT downregulated the mRNA and protein expression of genes related to the ERK1/2 signaling pathway. It increased the mRNA and protein expression levels of the EMT-related gene E-cadherin but decreased those of N-cadherin. Conclusion ACT could inhibit EMT and the invasion and migration of HCCLM3 cells in human hepatoma, and the underlying mechanism is closely related to the downregulation of the ERK1/2 signaling pathway.

Neotuberostemonine and tuberostemonine ameliorate pulmonary fibrosis through suppressing TGF-β and SDF-1 secreted by macrophages and fibroblasts via the PI3K-dependent AKT and ERK pathways / 中国天然药物

Activated fibroblasts and M2-polarized macrophages may contribute to the progression of pulmonary fibrosis by forming a positive feedback loop. This study was aimed to investigate whether fibroblasts and macrophages form this loop by secreting SDF-1 and TGF-β and the impacts of neotuberostemonine (NTS) and tuberostemonine (TS). Mice were intratracheally injected with 3 U·kg-1 bleomycin and orally administered with 30 mg·kg-1 NTS or TS. Primary pulmonary fibroblasts (PFBs) and MH-S cells (alveolar macrophages) were used in vitro. The animal experiments showed that NTS and TS improved fibrosis related indicators, inhibited fibroblast activation and macrophage M2 polarization, and reduced the levels of TGF-β and SDF-1 in alveolar lavage fluid. Cell experiments showed that TGF-β1 may activated fibroblasts into myofibroblasts secreting SDF-1 by activating the PI3K/AKT/HIF-1α and PI3K/PAK/RAF/ERK/HIF-1α pathways. It was also found for the first time that SDF-1 was able to directly polarize macrophages into M2 phenotype secreting TGF-β through the same pathways as mentioned above. Moreover, the results of the cell coculture confirmed that fibroblasts and macrophages actually developed a feedback loop to promote fibrosis, and the secretion of TGF-β and SDF-1 was crucial for maintaining this loop. NTS and TS may disturb this loop through inhibiting both the PI3K/AKT/HIF-1α and PI3K/PAK/RAF/ERK/HIF-1α pathways to improve pulmonary fibrosis. NTS and TS are stereoisomeric alkaloids with pyrrole[1,2-a]azapine skeleton, and their effect on improving pulmonary fibrosis may be largely attributed to their parent nucleus. Moreover, this study found that inhibition of both the AKT and ERK pathways is essential for maximizing the improvement of pulmonary fibrosis.

Mechanism of Gentisic Acid on Rheumatoid Arthritis Based on miR-19b-3p/RAF1 Axis / 中国结合医学杂志

OBJECTIVE@#To investigate the therapeutic effect of gentisic acid (GA) on rheumatoid arthritis (RA) based on the miR-19b-3p/RAF1 axis.@*METHODS@#The cell counting kit-8 method was used to detect the growth inhibitory effect of different concentrations of GA on MH7A cells, and the drug concentration of GA was determined in the experiment. The quantificational real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-19b-3p and RAF1. RAF1, extracellular regulated protein kinases1/2 (ERK1/2) and phospho-ERK1/2 (p-ERK1/2) were examined by Western blotting. Three methods (dual-luciferase assay, qRT-PCR and Western blot analysis) were used to verify miR-19b-3p targeting RAF1. Flow cytometry was performed to detect MH7A cell apoptosis. Transwell and wound healing assays were used to determine the invasion and migration capacities of MH7A cells.@*RESULTS@#The growth of MH7A cells was gradually inhibited with increasing GA concentration. When the GA concentration exceeded 80 mmol/L, GA was significantly cytotoxic to MH7A cells, so the half maximal inhibitory concentration of GA for MH7A cells was calculated as 67.019 mmol/L. GA upregulated miR-19b-3p expression, downregulated RAF1 expression, inhibited ERK1/2 phosphorylation, induced MH7A cell apoptosis and suppressed MH7A cell invasion and migration (P<0.05 or P<0.01). RAF1 was identified as the target of miR-19b-3p and reversed inhibitory effects on miR-19b-3p expression (P<0.05 or P<0.01). The miR-19b-3p inhibitor upregulated RAF1 expression and ERK1/2 phosphorylation, suppressed MH7A cell apoptosis and induced MH7A cell invasion and migration (P<0.01).@*CONCLUSION@#GA regulated miR-19b-3p/RAF1 axis to mediate ERK pathway and inhibit the development of RA.

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 / 中华劳动卫生职业病杂志

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-1β 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-1β [ (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-1β 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.

Echinacoside hampers malignant progression of breast cancer MCF-7 cells by modulating AKR1B10/ERK signal transduction / 中国中药杂志

This study analyzes the impact of echinacoside(ECH) in the proliferation, metastasis and adriamycin(ADR) resistance of breast cancer(BC) MCF-7 cells via the modulation of aldo-keto reductase family 1 member 10(AKR1B10)/extracellular signal-regulated kinase(ERK) pathway. The chemical structure of ECH was firstly confirmed. MCF-7 cells were treated with different concentration(0, 10, 20, 40 μg·mL~(-1)) of ECH for 48 h. Western blot was used to analyze expression of AKR1B10/ERK pathway-associated proteins and cell counting kit-8(CCK-8) assay to determine cell viability. MCF-7 cells were collected and classified into control group, ECH group, ECH + Ov-NC group, and ECH + Ov-AKR1B10 group. Then Western blot was employed to analyze the expression of AKR1B10/ERK pathway-associated proteins. CCK-8 and 5-ethynyl-2'-deoxyuridine(EdU) assay were used to examine cell proliferation. Cell migration was appraised with scratch assay, Transwell assay, and Western blot. Eventually, MCF-7 cells were treated with ADR for 48 h to induce ADR resistance. Cell viability was tested by CCK-8 assay and cell apoptosis was estimated based on terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) assay and Western blot. Based on Protein Data Bank(PDB) and molecular docking, the binding affinity of ECH to AKR1B10 was assessed. Various doses of ECH decreased the expression of AKR1B10/ERK pathway-associated proteins in a dose-dependent manner and declined cell viability compared with the control group. Compared with the control group, 40 μg·mL~(-1) ECH blocked the AKR1B10/ERK pathway in MCF-7 cells and inhibited the proliferation, metastasis and ADR resistance of the cells. Compared with the ECH + Ov-NC group, ECH + Ov-AKR1B10 group showed the recovery of some biological behaviors of MCF-7 cells. ECH also targeted AKR1B10. ECH can inhibit the proliferation, metastasis, and ADR resistance of BC cells by blocking AKR1B10/ERK pathway.

Lenvatinib down-regulates IGF1R/Mek/Erk signaling pathway in the treatment of regorafenib-resistant hepatocellular carcinoma / 中华肿瘤杂志

Objective: To investigate the therapeutic effect and mechanism of lenvatinib on regorafenib-resistant hepatocellular carcinoma cells. Methods: CCK-8 and clone formation assay were used to observe the inhibitory effect of lenvatinib on the growth of hepatocellular carcinoma cells. Flow cytometry was used to detect the apoptosis of regorafenib-resistant hepatocellular carcinoma cells treated with lenvatinib. The expression levels of related proteins were detected by western blot and immunohistochemical staining. The inhibitory effect of lenvatinib on the tumor formation ability of regorafenib-resistant hepatocellular carcinoma cells in vivo was observed by subcutaneous tumor formation experiment in mice. Results: CCK-8 and clone formation assay showed that lenvatinib could inhibit the proliferation of regorafenib-resistant hepatocellular carcinoma cells. The number of clones of HepG2, SMMC7721 and regorafenib-resistant HepG2, SMMC7721 cells in lenvatinib group (120.67±11.06, 53.00±11.14, 55.00±9.54, 78.67±14.64) were all lower than those in control group (478.00±24.52, 566.00±27.87, 333.67±7.02, 210.00±12.77, all P<0.05). Flow cytometry showed that lenvatinib could promote apoptosis of regorafenib-resistant hepatocellular carcinoma cells, the apoptosis rates of HepG2, SMMC7721 and regorafenib-resistant HepG2, SMMC7721 cells in lenvatinib group [(12.30±0.70)%, (9.83±0.38)%, (15.90±1.32)%, (10.60±0.00)%] were all higher than those in control group [(7.50±0.87)%, (5.00±1.21)%, (8.10±1.61)%, (7.05±0.78)%, all P<0.05]. The apoptosis-related protein levels suggested that apoptosis was increased in the treatment of lenvatinib. The animal study showed that lenvatinib can inhibit the growth of regorafenib-resistant cells in vivo. Immunohistochemistry and western blot results showed that lenvatinib could down-regulate the abnormally activated IGF1R/Mek/Erk signaling pathway in regorafenib-resistant cells. Conclusion: Lenvatinib can reverse regorafenib resistance in hepatocellular carcinoma, possibly by down-regulating IGF1R/Mek/Erk signaling pathway.

Chinese Medicines Regulate p38 MAPK， ERK1/2， and JNK in Treatment of Osteoporosis： A Review / 中国实验方剂学杂志

With the aging of population， osteoporosis has become one of the main diseases endangering the health of the elderly in China. Therefore， the research on osteoporosis has become a hot spot. Since Chinese medicines demonstrate significant therapeutic effects on osteoporosis， this issue is attracting increasing attention from researchers， especially in the deciphering of the molecular mechanism. This paper introduces the mechanism of the prevention and treatment of osteoporosis by Chinese medicines via the mitogen-activated protein kinase （MAPK） signaling pathway， aiming to provide a theoretical basis for deciphering the mechanism of Chinese medicines in the treatment of osteoporosis and promoting their clinical application. MAPK signaling pathway mainly involves p38 MAPK， extracellular signal-regulated kinase 1/2 （ERK1/2）， c-Jun N-terminal kinase （JNK）， and extracellular signal-regulated kinase 5 （ERK5）. Studies have shown that these proteins play a role in the progression of osteoporosis by regulating cell proliferation， differentiation， and apoptosis. Chinese medicines as a unique therapy with Chinese characteristics has definite efficacy， high safety， and mild side effects. Researchers have proved by experiments that the extracts or compounds of Chinese medicines can significantly mitigate osteoporosis by regulating the proteins involved in the MAPK signaling pathway. Therefore， this article reviews the relevant studies with focus on these proteins.

Effect of Yanghetang-containing Serum on Breast Cancer 4T1 Cells Based on MEK/ERK Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effects of Yanghetang （YHT） on breast cancer 4T1 cells and their mitogen-activated protein kinase （MEK）/extracellular signal-regulated kinase （ERK） signaling pathway. MethodThe YHT-containing serum was prepared from SD rats. The rats were randomly assigned into a blank group （normal saline） and low-， medium-， and high-dose （5.8， 11.6， 23.2 g·kg-1， respectively） YHT groups. The serum containing 10% YHT in each group was mixed with 90% RMPI 1640 complete medium， and the mixture was used to interfere with the cells. Cell counting kit-8 （CCK-8） method was used to detect the proliferation of the 4T1 cells treated with YHT for 24， 48， 72 h. The apoptosis， migration， and invasion of 4T1 cells were detected by flow cytometry， scratch test， and Transwell assay， respectively. Western blot was employed to determine the expression levels of MEK1/2， phosphorylation （p）-MEK1/2， ERK1/2， p-ERK1/2， and rat sarcoma virus （RAS） protein. ResultCompared with the blank group， the intervention with YHT-containing serum for 24， 48， and 72 h had significant inhibitory effect on 4T1 cell proliferation （P<0.05， P<0.01）. After intervention with YHT-containing serum for 48 h， the apoptosis rate of cells increased （P<0.01）. Compared with the blank group， the intervention with YHT for 24 h and 48 h decreased the healing ability of cells in the scratch test （P<0.01）. The invasive ability of cells treated with the low， medium， and high-dose YHT containing serum showed a decreasing trend （P<0.01）. Compared with the blank group， YHT-containing serum did not change the expression of MEK1/2 and ERK1/2 while down-regulating the expression of p-MEK1/2， p-ERK1/2， and RAS protein （P<0.01）. ConclusionYHT can inhibit the proliferation， migration， and invasion and promote the apoptosis of breast cancer 4T1 cells. In may promote the apoptosis by inhibiting the MEK/ERK signaling pathway and down-regulating the expression of p-MEK1/2， p-ERK1/2， and RAS protein.

Correlation Between ERK1/2 Signal Transduction and Ovarian Cancer / 肿瘤防治研究

Ovarian cancer is one of the common tumors in female reproductive organs and accounts for about 4% of all malignant tumors in women. It is also the leading cause of death among various gynecological tumors. Surgery combined with chemotherapy is the frequently used treatment for ovarian. Chemotherapy resistance is one of the main reasons for the recurrence and poor prognosis of ovarian cancer. Various components of the MAPK pathway, also known as the RAS-RAF-MEK-ERK signaling cascade, are related to cancer, and ERK1/2 is an indispensable key site in this pathway. Continuous research has found that ERK1/2 is a "ferryman" involved in regulating the occurrence, development, and drug resistance mechanisms of ovarian cancer. This article briefly introduces the activation mechanism and pathway of the ERK1/2 signaling pathway, summarizes its relationship to ovarian cancer, and emphasizes that ERK1/2 inhibitors may be a new treatment strategy with potential advantages in improving poor prognosis in patients with ovarian cancer.

Yiqi Huoxue Tongluo Prescription Inhibits Activation of Astrocytes to Relieve Diabetic Neuropathic Pain in Rats via ERK Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Yiqi Huoxue Tongluo prescription （YHTP） in the treatment of diabetic neuropathic pain （DNP）. MethodNinety SPF-grade SD male rats were randomized into blank， model， low- （2.25 g·kg-1）， medium- （4.5 g·kg-1）， and high-dose （9 g·kg-1） YHTP， and mecobalamin （0.175 mg·kg-1） groups. Except those in the blank group， the rats in the remaining 5 groups were fed with a high-fat and high-glucose diet and subjected to intraperitoneal injection of low-dose （35 mg·kg-1） streptozotocin （STZ） to establish the model of DNP. The sciatic nerve conduction velocity in DNP rats was measured by the neurophysiological method， and the levels of interleukin-6 （IL-6）， IL-1β， and tumor necrosis factor-α （TNF-α） were measured by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was employed to measure the mRNA levels of glial fibrillary acidic protein （GFAP） and extracellular signal-regulated kinase （ERK） in the spinal cord. Western blot was employed to measure the protein levels of GFAP and phosphorylated ERK （p-ERK）， and immunofluorescence staining to measure the fluorescence intensity of GFAP and p-ERK in the spinal cord. In the cell experiments， 100 mmol·L-1 high glucose was used to induce the activation of astrocytes （CTX-TNA2） for the modeling of nerve cell injury. The cells were randomized into the normal， model， drug-containing serum （10% YQHT）， inhibitor ［10 mol·L-1 corynoxeine （COR）］， drug-containing serum + inhibitor （10% YHTP + 10 mol·L-1 COR） groups. The levels of pro-inflammatory factors （TNF-α and IL-1β） and the anti-inflammatory factor IL-10 in CTX-TNA2 cells were determined by ELISA， and the protein levels of GFAP and p-ERK in CTX-TNA2 cells by Western blot. ResultThe animal experiments showed that compared with the blank group， the model group presented reduced mechanical withdrawal threshold （MWT）， thermal work limit （TWL）， and nerve conduction velocity， elevated levels of fasting blood glucose， IL-1β， TNF-α， and IL-6， and up-regulated protein levels of GFAP and p-ERK， and mRNA levels of ERK1， ERK2， GFAP （P<0.01）. Compared with model group， YHTP increased the MWT， TWL， and sciatic nerve conduction velocity （P<0.01）， lowered the levels of IL-1β， TNF-α， and IL-6 （P<0.01）， and down-regulated the protein levels of GFAP and p-ERK， and mRNA levels of ERK1， ERK2， GFAP in the spinal cord （P<0.05， P<0.01）. The cell experiments showed that compared with the blank group， the model group had decreased survival rate， elevated levels of pro-inflammatory factors， and up-regulated protein levels of ERK and GFAP （P<0.01）. Compared with the model group， the YHTP-containing serum lowered the levels of IL-1β and TNF-α （P<0.05， P<0.01）， elevated the level of IL-10 （P<0.01）， and down-regulated the protein levels of ERK and GFAP （P<0.01）. ConclusionYHTP may inhibit the activation of astrocytes by inhibiting the ERK signaling pathway to reduce inflammation and thus relieve DNP.

Research progress on function and molecular mechanism of transcription factor ELK1 of Ets / 中国生物制品学杂志

@#Ets transcription factor ELK 1,a member of the ternary complex factor(TCF) subfamily in the Ets family,is directly downstream signal of MAPK/ERK pathway and is activated by phosphorylation to execute the function of ERK signal.ELK1,which is highly expressed and phosphorylated in stem cells and tumor cells,plays a role in promoting proliferation,inhibiting apoptosis and differentiation in stem cells.In tumor cells,ELK1 has shown to promote proliferation,migration,and inhibit apoptosis.In neural cells,ELK1 is involved in long-term memory,learning,addiction and other functions.In this paper,the research progress on the main structure and basic biological characteristics of ELK1,the function and mechanism of ELK 1 in tumor cells,stem cells and nerve cells are reviewed in order to provide new ideas for the follow-up research.

Quercetin exhibits neuroprotective effect by reduc-ing amyloid precursor protein expression and oxida-tive stress in Neuro2a/APPswe cell model / 中国药理学与毒理学杂志

OBJECTIVE The abnormal amyloid-β(Aβ)and oxidative stress assiociated with the progression of Alzheimer disease(AD).Quercetin has been reported to possess antioxidant and anti-inflammatory properties in neurodegenerative disorders.In this present study,we designed to characterize the mechanisms by which quer-cetin exerts neuroprotective effects in murine neuroblas-toma N2a cells stably expressing human Swedish mutant amyloid precursor protein(N2a/APP).METHODS N2a/APP cells were treated with quercetin at concentrations of 10,20 and 50 μ mol·L-1 for 24 h.Cell viability was examined with CCK-8 assays.The protein levels of ERK1/2 and Akt were detected by Western blotting.Intra-cellular reactive oxygen species(ROS)was detected by a fluorescent probe 2,7-dichlorofluorescein diacetate(DCFH-DA).The mitochondrial membrane potential(Δψ m)in N2a/APP cells was detected by using JC-1 staining method.Immunofluorescence was used to detect the generation of 8-hydroxy-2′-deoxyguanosine(8-OHdG)and 4-hydroxynonenal(4-HNE).RESULTS Quercetin attenuated the enhancement of p-ERK1/2,reductions of p-Akt,and decreased levels of APP expression.More-over,quercetin alleviated loss of mitochondria membrane potential(MMP)since it attenuates these oxidative stress,as reflected in the levels of ROS,4-HNE and 8-OHdG,was elevated in N2a/APP cells and these effects were again ameliorated by quercetin.CONCLUSION Neuroprotection by quercetin in N2a/APP cells involves normalizing the impaired mitochondrial function and reducing oxidative stress via inactivation of the ERK1/2 and activation of the Akt pathways.

Role of free radicals in cerebral ischemic tolerance of rats induced by limb ischemic preconditioning / 中国病理生理杂志

AIM: To explore whether free radicals participate in cerebral ischemic tolerance and the up-regula-tion of p38 MAPK and ERK signaling pathways in rats induced by limb ischemic preconditioning (LIP). METHODS: A total of 128 Wistar rats with permanent occlusion of bilateral vertebral arteries were randomly divided into sham group (n=16), cerebral ischemia (CI) group (n=16), LIP+CI group (n=16), DMTU (a free radical scavenger)+LIP+CI group (n=64) and DMTU+sham group (n=16). Six rats in each group were used to observe the delayed neuronal death (DND) in hippocampal CA1 region by thionin staining at 7 d after the end of operation. Other 10 rats in each group were used to de-tect the expression of p38 MAPK and ERK in hippocampal CA1 region by immunohistochemistry and Western blot. RE-SULTS: Lethal CI resulted in obvious DND in hippocampal CA1 region. However, LIP reversed the above injurious changes, represented by the decrease in histological grade and the increase in neuronal density compared with CI group (P<0. 01). Moreover, LIP significantly up-regulated the expression of p38 MAPK and ERK in hippocampal CA1 region com-pared with CI group (P<0. 01). Administration of free radical scavenger DMTU via femoral vein before LIP partially re-versed the neuroprotective effect of LIP, and blocked the up-regulation of p38 MAPK and ERK expression in hippocampal CA1 region in rats compared with LIP+CI group (P<0. 01). CONCLUSION: Free radicals are involved in the neuropro-tection and up-regulation of p38 MAPK and ERK expression induced by LIP in rats.

Type III secretory protein SINC of Chlamydia psittaci promotes host cell autophagy by activating the MAPK/ERK signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effects of SINC, a secreted protein of Chlamydia psittaci, on autophagy of host cells and the role of MAPK/ERK signaling pathway in mediating SINC-induced autophagy.@*METHODS@#RAW 264.7 cells treated with recombinant SINC were examined for changes in expression levels of LC3-II, Beclin-1, phosphorylated and total ERK1/2 using Western blotting. The expression level of LC3 in the treated cells was detected using immunofluorescence analysis, and the formation of autophagosomes and autolysosomes was observed with transmission electron microscopy (TEM). The effect of pretreatment with U0126 (a specific ERK inhibitor) on the expression levels of LC3-II and Beclin-1 in RAW 264.7 cells exposed to different concentrations of SINC was examined using Western blotting, and LC3 puncta in the cells was detected with immunofluorescence analysis.@*RESULTS@#The expression levels of LC3-II and Beclin-1 were the highest in RAW 264.7 cells treated with 2 μg/mL SINC for 12h. Immunofluorescence analysis showed exposure to SINC significantly increased the number of cells containing LC3 puncta, where the presence of autophagosomes and autolysosomes was detected. Exposure to 2 μg/mL SINC for 15 min resulted in the most significant increase of the ratios of p-ERK1/2/ERK1/2 in RAW 264.7 cells. Pretreatment of the cells with U0126 prior to SINC exposure significantly decreased the ratio of p-ERK1/2/ERK1/2, lowered the expression levels of LC3-II and Beclin-1, and decreased LC3 aggregation in the cells.@*CONCLUSIONS@#SINC exposure can induce autophagy in RAW 264.7 cells by activating the MAPK/ERK signaling pathway.

DUSP6: Potential interactions with FXR1P in the nervous system

Fragile X syndrome (FXS) is a leading genetic cause of autism intellectual disorder and autism spectrum disorder (ASD), with either limited treatment options or incurable. Fragile X-related gene 1 (FXR1) is a homolog of the Fragile X mental retardation gene 1 (FMR1), the causative gene of FXS, and both are highly homologous and functionally identical. In FXS, both PI3K (AKT/mTOR signaling pathway) and ERK1/2 (MAPK signaling pathway) expression levels were abnormal. Dual speci?city phosphatase 6 (DUSP6) is a member of the mitogen-activated protein kinases (MAPKs) that participates in the crosstalk between the two signaling systems of MEK/ERK and mTOR. By interacting with multiple nodes of MAPK and PI3K/AKT signaling pathways (including the mTOR complex), DUSP6 regulates cellular growth, proliferation, metabolism and participates in pathological processes of cancer and cognitive impairment. However, whether there is an interaction between FXR1P and DUSP6 and the effects of DUSP6 on the growth of SK-N-SH cells remains elusive. As demonstrated by our results, FXR1P was identified in the cytoplasm and nucleus of SK-N-SH cells co-localized with DUSP6, which might have regulated ERK1/2 signaling pathways in SK-N-SH cells. To a certain extent, FXR1P may reverse the negative regulation of ERK1/2 by DUSP6. Moreover, we discovered that not only does DUSP6 inhibit proliferation, but it also promotes the apoptosis of SK-N-SH cells.

Lithocarpus polystachyus (Sweet Tea) water extract promotes human hepatocytes HL7702 proliferation through activation of HGF/AKT/ERK signaling pathway / 中草药·英文版

Objective: Sweet Tea (ST), derived from the leaves of Lithocarpus polystachyus, is a Chinese folk medicine with wide pharmacological activities. However, the promotive effects of ST water extract on hepatocytes proliferation and its underlying mechanism remains still unknown. In the present study, the beneficial effects of ST water extract on human hepatocytes and its possible mechanism were investigated. Methods: MTT assay was used to detect the safety range of ST; HL7702 cells were divided into four groups: control group, ST low- (50 μg/mL), medium- (200 μg/mL) and high-concentration (800 μg/mL) groups; BrdU ELISA and EDU staining were used to observe DNA content and cell proliferation; Moreover, flow cytometry was applied to analyze the distribution of cell cycle. Furthermore, the expression of cyclin D1, CDK4, HGF/c-Met, Akt, Erk1/2 were detected by Western blot. Results: It was found that ST water extract concentration-dependent promoted human hepatocytes HL7702 cell proliferation within 72 h through accumulating the cells in S phase and G2/M phase. Furthermore, ST water extract up-regulated expression of Cyclin D1 and CDK4 proteins. Moreover, ST water extract not only increased HGF expression and phosphorylation of c-Met level, but also activated the phosphorylation levels of AKT, ERK1/2. Interestingly, both of AKT inhibitor A6730 and ERK1/2 inhibitor U0126 reversed the promotive effects of ST water extract, which further confirmed that activation of AKT and ERK1/2 were involved. Conclusion: The findings reveal that ST water extract promoted HL7702 cells proliferation through the stimulation of cell cycle mediated by activating the AKT- and ERK1/2-related pathway.