Wenxiao Powder Alleviates Depression by Promoting Neurogenesis via BDNF/TrkB/ERK/CREB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo decipher the mechanism of Wenxiao powder in alleviating corticosterone-induced depression-like behaviors in mice. MethodMale ICR mice were randomized into normal， model， paroxetine （20 mg·kg-1）， and low- and high-dose （3.27， 6.54 g·kg-1， respectively） Wenxiao powder groups. The mice in normal and model groups received equal volume of saline. Other groups except the normal group were injected with corticosterone subcutaneously 0.5 h after gavage to induce depression. Mice were tested for depression-like behaviors after drug administration. Enzyme-linked immunosorbent assay （ELISA） was performed to measure the corticosterone content in the serum. Nissl staining was performed to observe the damage of hippocampal neurons. Immunofluorescence staining was employed to observe the expression of double cortin （DCX） in the dentate gyrus （DG） of the hippocampus. Western blot was employed to determine the expression of proteins in the brain-derived neurotrophic factor （BDNF）/tyrosine kinase receptor B （TrkB）/extracellular signal-regulated kinase （ERK）/cAMP-response element-binding protein （CREB） pathway in the hippocampus. ResultCompared with the normal group， the model group showed decreased sucrose preference rate， increased immobility time in the tail suspension test （P<0.01）， and reduced residence time in the central area of the open field and the total movement distance （P<0.05， P<0.01）. In addition， the modeling elevated the corticosterone level in the serum （P<0.01）， decreased the volume and intensified the nuclear staining of hippocampal neurons in the DG area， reduced the expression of DCX in the DG area， and down-regulated the protein levels of BDNF， phosphorylated （p）-TrkB， p-ERK， and p-CREB in the hippocampus （P<0.05， P<0.01）. Compared with the model group， low-dose Wenxiao powder improved the mouse behavivors in the sucrose preference， open field， and tail suspension tests （P<0.05， P<0.01）， and high-dose Wenxiao powder improved the behaviors in the sucrose preference and open field tests （P<0.05， P<0.01）. In addition， Wenxiao powder lowered the serum corticosterone level （P<0.01） and recovered the structure and morphology of neurons with obvious nuclei and presence of Nissl bodies in the DG area of the hippocampus. Moreover， Wenxiao powder at both doses promoted the expression of DCX in the DG area， and high-dose Wenxiao powder up-regulated the protein levels of BDNF， p-TrkB， p-ERK， and p-CREB in the hippocampus （P<0.05， P<0.01）. ConclusionWenxiao powder can alleviate corticosterone-induced depression-like behaviors and promote neurogenesis in mice possibly by activating the BDNF/TrkB/ERK/CREB signaling pathway.

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.

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.

Effect of Shufeng Tongluo Prescription on Eotaxin and CCR3 Protein Expression and ERK Phosphorylation Level of Asthma Mice / 中国实验方剂学杂志

ObjectiveTo preliminarily explore the mechanism of Shufeng Tongluo prescription （SFTLP） in inhibiting airway inflammation in asthma mice by affecting the expression levels of eotaxin in the serum， CC type chemokine receptor 3 （CCR3）， and extracellular signal-regulated kinase （ERK） phosphorylation in lung tissues. MethodSeventy C57BL/6 mice were randomly divided into a blank group， a model group， low-， medium-， and high-dose SFTLP groups （7.75， 15.5， 30 g·kg-1）， a pertussis toxin （PTX） group， a CCR3 inhibitor （SB328437） group， a phosphoinositide 3-kinase （PI3K） inhibitor （LY294002） group， a p38 protein kinase antagonist inhibitor （SB203580） group， and an ERK inhibitor （PD98059） group. The asthma model was induced in mice by intraperitoneal injection of ovalbumin （OVA） and aluminum hydroxide ［Al（OH）3］ combined with OVA atomization （0.2 mL for all）. After modeling， hematoxylin-eosin staining （HE staining） was used to observe the inflammatory infiltration of lung tissues in mice. Enzyme-linked immunosorbent assay （ELISA） was used to detect the serum levels of eotaxin ［CC chemokine ligand （CCL） 11 and CCL24） in each group. Western blot was used to detect the levels of ERK phosphorylation and CCR3 in lung tissues. ResultCompared with the blank group， the model group showed obvious bronchial constriction， lumen stenosis， damaged alveolar structure， massive inflammatory cell infiltration in lung tissues， mucous plug in the bronchus， edema in the submucosal tissues of the trachea， increased folds， increased serum levels of CCL11 and CCL24 （P<0.01）， and increased expression of CCR3 protein in lung tissues （P<0.05）. The ERK levels in lung tissues of the model group and the PTX group increased （P<0.05）. The level of p-ERK in lung tissues of the model group and the low-dose SFTLP group increased （P<0.05）. As revealed by pathological results， compared with the model group， the high-dose SFTLP group showed relieved lung lesions. The high-dose SFTLP group and the SB328437 group showed reduced CCL11 content （P<0.05）. The low- and high-dose SFTLP group， the PTX group， the SB203580 group， the PD98059 group， and the SB328437 group showed decreased CCR3 protein expression in lung tissues （P<0.05）. The high-dose SFTLP group and the PD98059 group showed reduced p-ERK level （P<0.05）. The PD98059 group showed reduced ERK level （P<0.05）. ConclusionSFTLP can inhibit airway inflammation in asthma， and the mechanism may be related to the inhibition of eosinophil activation by down-regulating CCR3 and CCL11 expression and ERK phosphorylation.

Effect of Notoginseng Total Saponins on Changing Multidrug Resistance in HepG2/ Adriamycin Cells Through ERK/Akt Signaling / 中国实验方剂学杂志

Objective:To investigate the effect of notoginseng total saponins （TNS） on adriamycin （Adr） resistance in HepG2/Adr cells and the expression and activity of the mechanisms as the modulators of multi-drug resistance， so as to explore the possible mechanism of extracellular signal-regulated kinase （ERK） and protein kinase B （Akt） signaling pathways in reversing the resistance of HepG2/Adr cells mechanism. Method:Effect of TNS on HepG2/Adr cell proliferation was detected by thiazole blue （MTT） method. HepG2/Adr cells were treated with different concentrations （100， 50， 25， 0 mg·L^-1） of TNS and （20 μmol·L^-1） Adr respectively， and a blank group was set. The high-content screening platform was used to detect the accumulation of Adr in HepG2/Adr cells after 40 minutes， 3 hours and 6 hours. Western blot was used to detect the expression of P-glycoprotein /multidrug resistance/ATP binding cassette subfamily B member 1（P-gp/MDR1/ABCB1） and other drug resistance-related proteins and the main protein expression of ERK/Akt signaling pathway. The change of MDR1 on cell membranes was observed by laser confocal microscopy. Result:Compared with HepG2 cells， the expression of MDR1 in HepG2/Adr cells was significantly increased （<italic>P</italic><0.01）. Compared with the Adr group， the half-inhibitory concentration （IC₅₀） of TNS （25， 50， 100 mg·L^-1） and Adr （20 μmol·L^-1） co-administration group on HepG2/Adr cells <italic>in vitro</italic> significantly reduced （<italic>P</italic><0.01）， and the highest reversal multiple was 10 times. Compared with the Adr group， the co-administration group could significantly increase the accumulation of Adr in the cells （<italic>P</italic><0.05） in a dose-dependent manner. Compared with the blank group， the co-administration group could significantly reduce MDR1， ABC semitransporter （ABCG2）， multidrug resistance associated protein （MRP1）， ERK， phosphorylated extracellular regulatory protein kinase （p-ERK）， Akt， phosphorylated protein kinase B （p-Akt）， mammals， rapamycin target protein （mTOR） and phosphorylated mammalian rapamycin target protein （p-mTOR） （<italic>P</italic><0.05）， with the same results in the doxorubicin group. Compared with the blank group， there was no significant difference in the distribution and fluorescence intensity of MDR1 on the cell membrane between the Adr group and the notoginseng total saponins （25 mg·L^-1） group. Compared with the blank group and the doxorubicin group， TNS could significantly reduce the distribution of MDR1 on the cell membrane （<italic>P</italic><0.05）. Conclusion:TNS can inhibit the ERK/Akt pathway， reduce the expression of MDR1， and significantly increase the accumulation of doxorubicin in HepG2/Adr cells， which may be one of the mechanisms of notoginseng total saponins in reversing resistance.

Shikonin Affects Uterine Leiomyoma in Rats by Regulating ERK Signaling Pathway / 中国实验方剂学杂志

Objective:To investigate the effect of shikonin on uterine leiomyoma in rats and its molecular mechanism. Method:Sixty female SD rats， of SPF grade and weighing 200-250 g， were randomly divided into the control group， model group， low-， medium-， and high-dose （5， 10， 20 mg·kg^-1） shikonin groups， and mifepristone group. A rat model of uterine leiomyoma was established， and the changes in uterine wet weight， uterine coefficient， and smooth muscle thickness were detected after drug administration for four successive weeks. The pathological changes in uterine tissue were observed by hematoxylin-eosin （HE） staining. The contents of estrogen receptor （ER） and progesterone receptor （PR） in serum and uterus were measured by enzyme-linked immunosorbent assay （ELISA）， and the protein expression levels of ER， PR， phosphorylated extracellular signal-regulated kinase （p-ERK）， and ERK in the uterine tissue were assayed by Western blot. Result:Compared with the control group， the model group exhibited significantly increased uterine wet weight， uterine coefficient， and smooth muscle thickness （<italic>P</italic><0.01）， uterus deformity， focal smooth muscle cell necrosis and hyperplasia， neutrophil infiltration. elevated serum and uterine ER and PR （<italic>P</italic><0.01）， and up-regulated p-ERK protein expression in the uterine tissue （<italic>P</italic><0.01）. Compared with the model group， shikonin at the middle and high doses and mifepristone significantly reduced the uterine wet weight， uterine coefficient， and smooth muscle thickness （<italic>P</italic><0.01）， relieved the pathological changes in uterus，and lowered serum and uterine ER and PR， and down-regulated the p-ERK protein expression in the uterine tissue （<italic>P</italic><0.05）. In addition， the uterine wet weight， smooth muscle thickness， serum ER， and uterine PR and p-ERK protein expression in the low-dose shikonin group were significantly lower than those in the model group （<italic>P</italic><0.05）. Conclusion:Shikonin produces the anti-uterine leiomyoma activity possibly by inhibiting the activation of ERK pathway.

Research progress of ERK small molecule inhibitors / 中国药科大学学报

@#Extracellular signal-regulated kinase (ERK) is a kind of serine/threonine protein kinase. As a key downstream protein in RAS-RAF-MEK-ERK signaling pathway, its abnormal activation plays an important role in the development of tumors. Selective ERK1/2 inhibitors can block ERK signaling pathway while overcoming drug resistance caused by upstream target mutation. In this paper, the components of MAPK signaling pathway, the structure and functions of ERK and the role of ERK signaling pathway in tumor development are summarized, and some representative ERK inhibitors in clinical or preclinical studies are emphasized.

Propofol activates rat hippocampal astrocytes time-dependently via ERK signaling pathway / 上海交通大学学报（医学版）

Objective: To detect the effects of propofol on rat hippocampal astrocytes and clarify its mechanism. Methods: According to the time after propofol injection, twenty-four SD rats were randomly divided into three groups, i. e. 0 min, 45 min and 90 min group. Rats were administrated intraperitoneally with propofol (10 mg/mL, 100 mg/kg body weight). The levels of glial fibrillary acidic protein (GFAP) and S100β mRNA in rat hippocampus were evaluated by realtime PCR. And cell viabilities and levels of GFAP mRNA were examined in primary cultured hippocampal astrocytes induced by 10 μmol/L propofol with or without 10 μmol/L extracellular signal-regulated kinase (ERK) inhibitor PD98059 pretreatment. Results: The mRNA levels of GFAP in the hippocampal tissue were (1.32±0.12) times (P=0.000) and (1.12±0.09) times (P=0.012) that in 0 min group, respectively, 45 min and 90 min after injection of propofol. The mRNA levels of S100β in the hippocampal tissue were (1.14±0.11) times (P=0.005) and (1.05±0.10) times (P=0.284) that in 0 min group, respectively, 45 min and 90 min after injection of propofol. The mRNA levels of GFAP and S100β were timedependently altered, first increasing, and then decreasing. In vitro, the cell viabilities (P=0.041) and levels of GFAP mRNA (P=0.026) in primary cultured hippocampal astrocytes were significantly elevated after propofol treatment, and these effects of propofol were reversed by ERK inhibitor PD98059. Conclusion: Propofol time-dependently upregulated the expression of GFAP and S100β via ERK signaling pathway in rat hippocampal astrocytes, so as to activate astrocytes.

Propofol activates rat hippocampal astrocytes time-dependently via ERK signaling pathway / 上海交通大学学报（医学版）

Objective·To detect the effects of propofol on rat hippocampal astrocytes and clarify its mechanism.Methods·According to the time after propofol injection,twenty-four SD rats were randomly divided into three groups,i.e.0 min,45 min and 90 min group.Rats were administrated intraperitoneally with propofol (10 mg/mL,100 mg/kg body weight).The levels of glial fibrillary acidic protein (GFAP) and S100β mRNA in rat hippocampus were evaluated by realtime PCR.And cell viabilities and levels of GFAP mRNA were examined in primary cultured hippocampal astrocytes induced by 10 μmol/L propofol with or without 10 μmol/L extracellular signal-regulated kinase (ERK) inhibitor PD98059 pretreatment.Results·The mRNA levels of GFAP in the hippocampal tissue were (1.32±0.12) times (P=0.000) and (1.12±0.09) times (P=0.012) that in 0 min group,respectively,45 min and 90 min after injection of propofol.The mRNA levels of S100β in the hippocampal tissue were (1.14±0.11) times (P=0.005) and (1.05±0.10)times (P=0.284) that in 0 min group,respectively,45 min and 90 min after injection of propofol.The mRNA levels of GFAP and S100β were timedependently altered,first increasing,and then decreasing.In vitro,the cell viabilities (P=0.041) and levels of GFAP mRNA (P=0.026) in primary cultured hippocampal astrocytes were significantly elevated after propofol treatment,and these effects of propofol were reversed by ERK inhibitor PD98059.Conclusion·Propofol time-dependently upregulated the expression of GFAP and S100β via ERK signaling pathway in rat hippocampal astrocytes,so as to activate astrocytes.

Role of p-ERK1/2 in 17β estradiol-induced inhibition of propofol-caused neuroapoptosis in hippocampus of newborn rats / 中华麻醉学杂志

Objective To evaluate the role of phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) in 17β estradiol-induced inhibition of propofol-caused neuroapoptosis in the hippocampus of newborn rats.Methods Seventy-eight male Sprague-Dawley rats,aged 7 days,weighing ll-18 g,were divided into 6 groups (n =13 each) using a random number table:dimethyl sulfoxide (DMSO) group,fat emulsion group (group F),17β estradiol group (group E),propofol group (group P),propofol plus 17β estradiol group (group PE) and propofol plusl7β estradiol plus mitogen-activated protein kinase kinase 1/2 inhibitor U0126 group (group PEU).17β estradiol 600 μg/kg was injected subcutaneously every 24 h for 7 consecutive days in group E,and the equal volume of DMSO was given instead in group DMSO.Propofol 75 mg/kg was injected intraperitoneally every 24 h for 7 consecutive days in group P,and the equal volume of fat emulsion was injected instead in group F.Propofol 75 mg/kg was injected intraperitoneally,and 17β estradiol 600 μg/kg was injected subcutaneously every 24 h for 7 consecutive days in group PE.Propofol 75 mg/kg was injected intraperitoneally,17β estradiol 600 μg/kg was injected subcutaneously,and U0126 10 mg/kg was injected intraperitoneally every 24 h for 7 consecutive days in group PEU.At 15 min after the last injection,3 rats in each group were randomly selected,and arterial blood samples from the cardiac apex were collected for determination of arterial oxygen partial pressure.The animals were sacrificed at 24 h after the last injection for determination of the expression of activated caspase-3 (by immunohistochemistry) and p-ERK1/2 (by Western blot).Results There was no significant difference in arterial oxygen partial pressure between the six groups (P＞0.05).Compared with group F,the expression of activated caspase-3 was significantly up-regulated,and the expression of p-ERK1/2 was downregulated in group P (P＜0.05).Compared with group P,the expression of activated caspase-3 was significantly down-regulated,and the expression of p-ERK1/2 was up-regulated in group PE (P＜0.05).Compared with group PE,the expression of activated caspase-3 was significantly up-regulated,and the expression of p-ERK1/2 was down-regulated in group PEU (P＜0.05).Conclusion The mechanism by which 17β estradiol inhibits propofol-caused neuroapoptosis in the hippocampus is related to up-regulation of the expression of p-ERK1/2 in newborn rats.

Amniotic fluid exerts a neurotrophic influence on fetal neurodevelopment via the ERK/GSK-3 pathway

BACKGROUND: The fetus is surrounded by the amniotic fluid (AF) contained by the amniotic sac of the pregnant female. The AF is directly conveyed to the fetus during pregnancy. Although AF has recently been reported as an untapped resource containing various substances, it remains unclear whether the AF could influence fetal neurodevelopment. RESULTS: We used AF that was extracted from embryos at 16 days in pregnant SD rat and exposed the AF to the neural cells derived from the embryos of same rat. We found that the treatment of AF to cortical neurons increased the phosphorylation in ERK1/2 that is necessary for fetal neurodevelopment, which was inhibited by the treatment of MEK inhibitors. Moreover, we found the subsequent inhibition of glycogen synthase kinase-3 (GSK-3), which is an important determinant of cell fate in neural cells. Indeed, AF increased the neural clustering of cortical neurons, which revealed that the clustered cells were proliferating neural progenitor cells. Accordingly, we confirmed the ability of AF to increase the neural progenitor cells through neurosphere formation. Furthermore, we showed that the ERK/GSK-3 pathway was involved in AF-mediated neurosphere enlargement. CONCLUSIONS: Although the placenta mainly supplies oxygenated blood, nutrient substances for fetal development, these findings further suggest that circulating-AF into the fetus could affect fetal neurodevelopment via MAP kinases-derived GSK-3 pathway during pregnancy. Moreover, we suggest that AF could be utilized as a valuable resource in the field of regenerative medicine.

Role of extracellular signal-regulated kinase in central amygdala on fentanyl-induced hyperalgesia in rats / 中华麻醉学杂志

Objective To investigate the role of extracellular signal-regulated kinase1/2 (ERK1/2) in the central amygdala on fentanyl-induced hyperalgesia in rats.Methods Thirty-two male SpragueDawley rats, weighing 60-100 g, were randomly divided into 4 groups (n =8 each) using a random number table: control group (group C), fentanyl-induced hyperalgesia group (group H), U0124 group (group U1) , and U0126 group (group U2).A catheter was implanted in the central amygdale.In group C, normal saline was injected subcutaneously, and 6.5 h later dimethyl sulfoxide (DMSO) was injected via the catheter.In group H, fentanyl was injected subcutaneously to induce hyperalgesia, and 6.5 h later DMSO was injected via the catheter.In group U1, hyperalgesia was induced, and 6.5 h later ERK1 inhibitor U0124 1.5 nmol was injected via the catheter.In group U2, hyperalgesia was induced, and 6.5 h later ERK1/2 inhibitor U0126 1.5 nmol was injected via the catheter.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal threshold (TWT) were measured before fentanyl injection, at 6.5 h after injection, and at 30 min after DMSO or U0124/U0126 administration via the catheter (T0-2).After the last measurement of pain threshold, the rats were sacrificed, and the amygdala tissues were sampled for detection of the expression of phosphorylated ERK1/2 (p-ERK1/2) by Western blot in groups C and H.Results Compared with group C, the MWT and TWT were significantly decreased at T1,2in H and U1 groups, and at T1in group U2 (P＜0.05) , the expression of p-ERK2 was up-regulated (P＜0.05) , and no significant change was found in the expression of p-ERK1 in group H (P＞0.05).Compared with group H,the MWT and TWT were significantly increased at T2 in group U2 (P＜0.05) , and no significant change was found in MWT, TWT in group U1 (P＞0.05).Conclusion ERK2 activation in the central amygdala is involved in the development of fentanyl-induced hyperalgesia in rats.

Down-regulation of HIV-1 Infection by Inhibition of the MAPK Signaling Pathway / 中国病毒学·英文版

The human immunodeficiency virus type 1(HIV-1)can interact with and exploit the host cellular machinery to replicate and propagate itself.Numerous studies have shown that the Mitogen-activated protein kinase(MAPK)signal pathway can positively regulate the replication of HIV-1,but exactly how each MAPK pathway affects HIV-1 infection and replication is not understood.In this study,we used the Extracellular signal-regulated kinase(ERK)pathway inhibitor,PD98059,the Jun N-terminal kinase(JNK)pathway inhibitor,SP600125,and the p38 pathway inhibitor,SB203580,to investigate the roles of these pathways in HIV-1replication.We found that application of PD98059 results in a strong VSV-G pseudotyped HIV-1NL4-3 luciferase reporter virus and HIV-1NL4-3 virus inhibition activity.In addition,SB203580 and SP600125 also elicited marked VSV-G pseudotyped HIV-1NL4-3 luciferase reporter virus inhibition activity but no HIV-1NL4-3 virus inhibition activity.We also found that SB203580 and SP600125 can enhance the HIV-1 inhibition activity of PD98059when cells were treated with all three MAPK pathway inhibitors in combination.Finally,we show that HIV-1virus inhibition activity of the MAPK pathway inhibitors was the result of the negative regulation of HIV-1 LTR promoter activity.

Effect of 2,3,5,4′-tetrahydroxy Stilbene-2-O-β-D-glucoside on Activation of ERK in APP Transgenic Model of Alzheimer's Disease / 中国康复理论与实践

@#Objective To investigate the deficit of extracellular-signal regulated kinase (ERK)1/2 activation in the different age of Alzheimer's disease (AD)-like animal model and the protective effect of 2,3,5,4′-tetrahydroxy stilbene-2-O-β-D-glucoside(TSG), which is the main component of Polygonum multiflorum, on ERK activation. Methods A generally accepted animal model of AD - PDAPPV717I transgenic (Tg) mouse was observed from 4 to 16 months old. Tg mice were randomly divided into 3 model groups(4, 10 and 16 months old mice)and TSG treated (at doses 120 and 240 μmol/kg/d) groups. TSG was administered to some Tg mice with an age range 4-10 months. In untreated 10 months old Tg mice, the TSG was administrated to those falling in the age range 10-16 months. For the control group we adopted the same age and background C57BL/6J mice. The ERK1/2 expression and phosphorylation were detected by Western blotting.Results In the 4-month-old PDAPPV717I Tg mice, phosphorylation of ERK1/2 decreased significantly in hippocampus and cortex compared with age matched control. In the 10-month-old Tg mice, decrease of ERK1/2 activation was aggravated in cortex but was less in hippocampus. The treatment of TSG at the doses of 120 and 240 μmol/kg for 6 months (from the age of 4 to 10 months) significantly up-regulated ERK1/2 activation in Tg mice. In the 16-month-old Tg mice, over-activation of ERK1/2 occurred in both hippocampus and cortex. The transgenic mice treated by TSG for 6 months (from the age of 10 months to 16 months) showed significant inhibition of over-activation of ERK1/2. Expression of total ERK1/2 showed no difference among control, Tg model and TSG treated groups.Conclusion PDAPPV717I transgenic mice with an age range from 4 to 16 months revealed the time-dependent deficit of ERK1/2 activation. TSG can bring the down or over activation of ERK1/2 into normal. Because ERK1/2 activation plays the crucial role in cellular signal transduction and learning-memory ability, TSG may have beneficial potential to the prevention and treatment of neurodegenerative diseases like AD.

Phosphorylation and Expression of Extracellular Signal-regulated Kinase in Cerebral Ischemic Preconditioning Rats / 中国康复理论与实践

@#Objective To explore initially the role of extracellular signal-regulated kinase (ERK1/2) in cerebral ischemic preconditioning. Methods Healthy adult SD rats were randomly divided into 5 groups: normal control group; sham group; ischemic preconditioning or ischemia tolerance group; bee venom group; peripheral noxious tolerance group. SDS-PAGE, Western blot and Gel Doc imagine systems were applied to determine the ERK1/2 phosphorylation and protein expression in somatosensory cortex and hippocampus of rats. Results The phosphorylation level of ERK1 in somatosensory cortex increased significantly (P<0.05) after ischemic preconditioning, while no significant changes in ERK2 and that of ERK1/2 in hippocampus. No significant changes in ERK1/2 protein expression were found both in somatosensory cortex and hippocampus after ischemic preconditioning. Conclusion The increased ERK1 phosphorylation level in somatosensory cortex may be involved in cerebral ischemic preconditioning.

Regulation of Cell Proliferation and Apoptosis by ERK Signaling Pathway in Airway Smooth Muscle Cells of Rats / 中国生物化学与分子生物学报

The regulative role of extracellular signal-regulated kinase(ERK)signaling pathway on proliferation and apoptosis in rats' airway smooth muscle cells(ASMCs)was investigated.Primary cultures of ASMCs were established and cells between passages 4 and 7 were used for experiments.ASMCs were U-eated with ERK activator epidermal growth factor(EGF)and inhibitor PD98059.The expressions of ERK mRNA and protein were detected by RT-PCR and immunofluorescence staining.Proliferation of ASMCs were detected by MTT eolorimetric assay and [3H] thymidine incorporation.Apoptosis of ASMCs were detected by Hoechst staining and Annexin-V FITC PI donble staining.The levels of ERK1/2,phosphorylated forms of ERK1/2(p-ERK1/2) and proeaspase-3 protein were detected by Western blotting.The expressions of ERK mRNA and ERK protein were obviously observed in ASMCs. Compared with control,the absorbanee(A490) value and DNA synthesis index of PD-treated ASMCs were significantly decreased(P＜0.05).The apoptotic index and the percentage of the early apoptotic cells were significantly increased(P＜0.05).The expressions of ERK1/2 and pERK1/2 protein were significantly down-regulated.The expressions of procaspase-3 protein was significantly increased.Compared with c,ontrol,the A490 value and DNA synthesis index were significantly increased(P＜0.05)in EGF-treated cells.Apoptotic index and the percentage of the early apoptotic cells were significantly decreased(P＜0.05).The levels of ERK1/2 and pERK1/2 protein were significantly increased,and the levels of procaspase-3 protein were significantly decreased, There were no significant differences between control and P+E group(P＞0.05).ERK signaling pathway may play an important role in regulating ASMCs proliferation and apoptosis and ERK regulating the apoptosis of ASMCs possibly relates to the expressions of procaspase-3 protein. The finding will help to understand the mechanisms of asthmatic ASMCs involved in abnormal proliferation.

Nitric oxide synthase inhibitors suppression against expression of ERK in spinal cord of morphine dependent and withdrawal rats / 中国药理学通报

Aim This study aimed to explore the effects of intrathecal injection of nitric oxide synthase inhibitors(L-NAME,7-NI) on morphine withdrawal response and the the spinal p-ERK expression.Methods Rats were divided into 5 groups: control group,dependence group,withdrawal group, L-NAME group(L-NAME,it) and 7-NI group(7-NI,it).Morphine withdrawal score,touch evoked agitation scores(TEA scores),immunohistochemical and western-blotting technique were used to evaluate morphine withdrawal response and the expression of Fos and p-ERK in the spinal cord,respectively.Results Intrathecal injection of non-specific NOS inhibitor L-NAME,nNOS inhibitor 7-NI significantly alleviated morphine withdrawal symptoms.Morphine withdrawal scores in the L-NAME(22.1?4.52) and 7-NI groups(16.2?3.99) were significantly lower than that of the withdrawal group(28.6?4.89)(P

Effect of Sodium tanshinone ⅡA sulfonate on activation of extracellular signal-regulated kinase1/2 in angiotensin Ⅱ-induced cardiomyocyte hypertrophy / 中国药理学通报

Aim To observe effects of Sodium tanshinoneⅡA sulfonate(STS) on angiotensionⅡ(AngⅡ)-induced cardiomyocyte hypertrophy and the expression of phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2). Methods In the primary culture of neonatal rat cardiomyocytes, as indexes of cardiomyocyte hypertrophy, the total protein was determined by coomassie brilliant blue and protein synthesis rate was measured by [3H]-Leucine incorporation. The expression of p-ERK1/2 was assessed using Western blot and fluorescence microscope. Results ① The total protein and protein synthesis rate stimulated by Ang Ⅱ(1 ?mol?L-1)in the cardiomyocytes increased significantly in contrast to that of control; STS could effectively decrease the increased total protein level induced by Ang Ⅱand markedly inhibit synthesis of protein. ② AngⅡ(1 ?mol?L-1) had the effect of promoting activation of ERK1/2 and then appeared in nucleus rapidly. The translocation process of ERK1/2 induced by AngⅡ was blocked distinctly by STS. ③ Cardiomyocyte pretreated with Ang Ⅱ(1 ?mol?L-1)for 5 min, the p-ERK1/2 protein expression began to increase ,the peak effect was at 10 min. While pretreatment with STS(2, 10, 50 ?mol?L-1) ,Ang Ⅱ-induced increase in p-ERK1/2 were inhibited evidently. ④ In pretreatment of cardiomyocyte with STS in different doses for 30 min, STS was found to be able to inhibit the expression of p-ERK1/2 stimulated by AngⅡ in a dose-dependent manner. Conclusions The results suggested that activation of ERK1/2 might play an important role in cardiomyocytes hypertrophy induced by Ang Ⅱ,and the anti-hypertrophic effect of STS on cardiomyocyte hypertrophy induced by AngⅡ might be associated to its inhibitory effect on ERK signaling pathway.

EFFECTS OF FOLIC ACID ON APOPTOSIS OF NEURAL CELLS IN RATS WITH FOCAL CEREBRAL ISCHEMIA INJURY / 营养学报

Objective To investigate the effects of folic acid on apoptosis of neural cells after focal cerebral ischemia injury in rats and the mechanisms.Method Thirty two adult male Sprague-Dawley(SD) rats were randomly divided into sham operation group(SO),middle cerebral artery occlusion group(MCAO),MCAO+ low dose folic acid group(MCAO+FA-L) and MCAO+ high dose folic acid group(MCAO+FA-H).The model of middle cerebral artery occlusion(MCAO) was set up by using intraluminal filament method.The rats were sacrificed at D7 day after cerebral ischemia.The apoptotic rate of neural cells was examined by TUNEL test,and the expression of pERK1/2 protein was detected by Western blotting method,The MDA content and serum SOD and GSH-Px activities in rats were measured before and 28d after folic acid treatment and 7th day after ischemia.Results Compared with ischemia group,the apoptotic rate of neural cells and MDA content in both folic acid supplemented groups were decreased significantly(P