Spinal protein kinase A and phosphorylated extracellular signal-regulated kinase signaling are involved in the antinociceptive effect of phytohormone abscisic acid in rats / A proteína quinase A da medula espinhal e a sinalização da quinase fosforilada regulada por sinal extracelular estão envolvidas no efeito antinociceptivo do ácido fito-hormônio abscísico em ratos

Abstract Objective: The phytohormone abscisic acid (ABA) as a signaling molecule exists in various types of organisms from early multicellular to animal cells and tissues. It has been demonstrated that ABA has an antinociceptive effect in rodents. The present study was designed to assess the possible role of PKA and phosphorylated ERK (p-ERK) on the antinociceptive effects of intrathecal (i.t.) ABA in male Wistar rats. Methods: The animals were cannulated intrathecally and divided into different experimental groups (n=6‒7): Control (no surgery), vehicle (received ABA vehicle), ABA-treated groups (received ABA in doses of 10 or 20 µg/rat), ABA plus H.89 (PKA inhibitor)-treated group which received the inhibitor 15 min prior to the ABA injection. Tail-flick and hot-plate tests were used as acute nociceptive stimulators to assess ABA analgesic effects. p-ERK was evaluated in the dorsal portion of the spinal cord using immunoblotting. Results: Data showed that a microinjection of ABA (10 and 20 µg/rat, i.t.) significantly increased the nociceptive threshold in tail flick and hot plate tests. The application of PKA inhibitor (H.89, 100 nM/rat) significantly inhibited ABA-induced analgesic effects. Expression of p-ERK was significantly decreased in ABA-injected animals, which were not observed in the ABA+H.89-treated group. Conclusions: Overall, i.t. administration of ABA (10 µg/rat) induced analgesia and p-ERK down-expression likely by involving the PKA-dependent mechanism.

Resumo Objetivo: O ácido fito-hormônio abscísico (ABA) existe como molécula sinalizadora em vários tipos de organismos, de multicelulares a células e tecidos animais. Foi demonstrado que o ABA tem efeito antinociceptivo em roedores. O presente estudo foi desenhado para avaliar o possível papel da PKA e da ERK fosforilada (p-ERK) nos efeitos antinociceptivos do ABA intratecal (i.t.) em ratos Wistar machos. Métodos: Os animais foram canulados por via i.t. e divididos em diferentes grupos experimentais (n=6‒7): controle (sem cirurgia), veículo (veículo ABA recebido), grupos tratados com ABA (recebeu ABA em doses de 10 ou 20 µg/rato), grupo tratado com ABA mais H.89 (inibidor de PKA) que recebeu o inibidor 15 minutos antes da injeção de ABA. Os testes de movimento da cauda e placa quente foram utilizados como estimuladores nociceptivos agudos para avaliar os efeitos analgésicos da ABA. A p-ERK foi avaliada na porção dorsal da medula espinhal por imunotransferência. Resultados: A microinjeção de ABA (10 e 20 µg/rato, i.t.) aumentou significativamente o limiar nociceptivo nos testes de movimento da cauda e placa quente. A aplicação de inibidor de PKA (H.89, 100 nM/rato) inibiu significativamente os efeitos analgésicos induzidos por ABA. A expressão de p-ERK diminuiu significativamente em animais injetados com ABA que não foram observados no grupo tratado com ABA+H.89. Conclusões: No geral, a administração i.t. de ABA (10 µg/rato) induziu a analgesia e expressão negativa de p-ERK provavelmente envolvendo mecanismo dependente de PKA.

Analgesic effect of Fengshi Qutong Capsules on mice with chronic inflammatory pain caused by complete Freund's adjuvant / 中国中药杂志

The aim was to observe the analgesic effect of Fengshi Qutong Capsules(FSQTC) on chronic inflammatory pain in mice, and investigate its effect on p-ERK/COX-2 signal molecular activity. A model of chronic inflammatory pain was induced in mice by complete Freund's adjuvant(CFA). The mice were divided into normal control group, model group, model+FSQTC 0.3, 0.6 and 1.2 g·kg~(-1 )groups, model+positive control drug ibuprofen(IBP, 0.34 mg·kg~(-1)·d~(-1)) group, and normal control+ FSQTC 1.2 g·kg~(-1)group. FSQTC or IBP was given once a day by oral administration. Standard Von Frey fiber was used to evaluate the mechanical pain threshold, and the acetone stimulation was used to induce inflammatory plantar and observe the cold pain reaction scores. The mechanical pain threshold and cold pain reaction scores were observed before administration and 1, 2, 3, 4, 6 h after administration on the first day, as well as 3 h after administration on the 3 rd to 7 th day. The protein levels of PGE_2, COXs-1,2 and p-ERK in the spinal cord of the inflammatory foot and lumbar 4-5 were detected by enzyme-linked immunosorbent assay, Western blot, immunohistochemistry and immunofluorescence. The results showed that the mechanical pain threshold of the model group decreased and the cold pain reaction score increased as compared with the normal group. FSQTC application could dose-dependently increase the mechanical pain threshold and decrease the cold pain reaction score. The effect lasted for 6 h, most significant at 3 h. The effect of ibuprofen was similar to that of the 0.6 g·kg~(-1) dose group. In addition, FSQTC could reduce the abnormally increased protein content of PGE_2, COX-2 and p-ERK in the inflammatory foot and/or spinal cord of the model group, and the effect was most significant in middle and high dose groups. However, it had no effect on COX-1 in the inflammatory foot and spinal cord of mice. The results suggest that FSQTC has ob-vious analgesic effect on chronic inflammatory pain in mice, which may be related to inhibition of p-ERK/COX-2 signaling pathway.

Establishment of gefitinib resistant lung cancer cell line and changes of EGFR signaling pathway / 中国药理学通报

Aim To establish gefitinib resistant epidermal growth factor receptor(EGFR) mutant lung cancer cell lines and to explore the changes of downstream signaling pathway of EGFR. Methods Gefitinib concentration gradient method was used to induce the establishment of H3255 and HCC827 resistant cell lines, and CCK8 assay was used to detect the proliferation of gefitinib resistant cell lines H3255/GR and HCC827/ GR. Western blot was used to detect the changes of EGFR downstream signals in H3255, HCC827, H3255/GR and HCC827/GR cells. Results The proliferation of H3255/GR and HCC827/GR cells was significantly lower than that of non-drug resistant cells. The phosphorylation signal molecules p-AKT, p-ERK1/2 and p-STAT3 of H3255/GR and HCC827/ GR drug-resistant cell lines were no significantly changed compared with their non-drug-resistant cell lines. There was no significant change in the expression of p-STAT3 and p-ERKl/2 in H3255/GR cells treated with gefitinib, but the expression of p-AKT was significantly down-regulated, while gefitinib only slightly inhibited the expression of p-ERKl/2 in drugresistant H3255/GR cells. In HCC827/GR cells, p-AKT and p-STAT3 were not inhibited by gefitinib, while p-ERKl/2 was moderately inhibited. Conclusion There are significant differences in the signal mechanism of drug resistance between H3255/GR and HCC827/GR cell lines.

Effect of sulindac derivative K-80003 in combination with MEK inhibitor cobimetinib in breast cancer cells / 中国药理学通报

Aim: To determine whether the inhibition of K-80003-activated p-ERK could potentiate the anticancer effect of K-80003 in vitro and in vivo. Methods: The effects of K-80003 in combination with the MEK inhibitor cobimetinib on ERK activation and tumor cell apoptosis in breast cancer cells were detected by Western blot and immunohistochemical staining in MCF-7 breast cancer cells and MMTV-PyMT mammary transgenic mice. Results: K-80003 activation of ERK in MCF-7 breast cancer cells and in MMTV-PyMT mammary transgenic mice was strongly inhibited by co-treatment with cobimetinib. The co-treatment also resulted in a strong induction of apoptosis and inhibition of the growth of tumor cells in vitro and in animals, as compared with K-80003 alone. It was detected that K-80003 in combination with cobimetinib synergistically inhibited the growth of MMTV-PyMT tumor strongly, suggesting that K-80003 activation of ERK serves as an escape mechanism by which tumor cells develop resistance to K-80003 treatment. Conclusion: An attractive approach is identified to enhance the therapeutic effect of K-80003 and to overcome potential resistance associated with the K-80003 therapy.

Adenoid cystic carcinoma cells produce exosomes that promote tumor cell proliferation / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of exosomes released by adenoid cystic carcinoma (ACC) cell line SACC-83 on the proliferation of ACC cells.</p><p><b>METHODS</b>Exosomes were isolated from SACC-83 cell culture supernatants using total exosome isolation reagents. The whole-mount exosomes were characterized using transmission electron microscope and Western blotting. The exosomes were labeled with green fluorescent dye PKH67 and co-cultured with SACC-83 cells for 48 h, followed by staining with Alexa Fluor 594 phalloidin and DAPI to observe exosome uptake by the cells using laser scanning confocal microscopy (LSCM). The cell proliferation was assessed using MTT assay and wound healing assay, and the expressions of ERK and P-ERK in the co-cultured SACC-83 cells were detected using Western blotting.</p><p><b>RESULTS</b>The exosomes isolated from SACC-83 cells showed a size range of 30-100 nm and expressed the exosomal markers CD9, CD63 and TSG101. LSCM showed exosome uptake by SACC-83 cells, which exhibited accelerated proliferation and significantly enhanced P-ERK expression ( < 0.05) without significant changes in ERK expression.</p><p><b>CONCLUSIONS</b>SACC-83 cells produce exosomes that promote the tumor cell proliferation and enhances the cellular expression of P-ERK, suggesting a potential role of MAPK/ERK pathway activation in exosome-mediated acceleration of ACC cell proliferation.</p>

Effect of allicin on proliferation and apoptosis of KG-1 cells and its molecular mechanism / 中国中药杂志

Allicin is one of the main bioactive substances in garlic, with antibacterial, hypolipidemic and other pharmacological effects. In this study, apoptosis-related indicators were detected to explore the molecular mechanism of allicin on KG-1 cell proliferation inhibition. The apoptosis rate of KG-1 cells induced by allicin was detected by flow cytometry. The effect of allicin on the expressions of Bax, Bcl-2, survivin and ERK mRNA in KG-1 cells was detected by RT-qPCR. Western blot was used to detect the expressions of caspase 3, cleaved caspase 3, ERK1/2, p-ERK1/2 and survivin protein in KG-1 cells. According to the findings, compared with the control group, allicin could significantly inhibit the proliferation activity of KG-1 cells in a concentration-dependent and time-dependent manner. Flow cytometry showed that allicin could induce the apoptosis of KG-1 cells, which was mainly late apoptosis. The results of RT-qPCR showed that the expressions of Bax mRNA, Bcl-2, survivin and ERK mRNA in KG-1 cells increased after treatment with allicin. The results of Western-blot showed that after KG-1 cells were treated with allicin, the expressions of caspase 3 and its active form cleaved caspase 3 increased, the expressions of survivin, ERK1/2 and its active form p-ERK1/2 were decreased, of which p-ERK1/2 was down-regulated in a dose-dependent manner. The above results suggest that allicin inhibited the proliferation of KG-1 cells primarily by inducing late apoptosis; the execution of apoptosis involved cleaved caspase 3; the induction of apoptosis involved the protein expression, the decrease of ERK1/2andexpression of survivin and the dose-dependent decrease of p-ERK1/2; the mRNA expression involved the increase of Bax, and the down-regulation of survivin, Bcl-2 and ERK1/2.

Effects of cisplatin on autophagy and apoptosis and their correlation in bladder cancer cells / 基础医学与临床

Objective To identify whether cisplatin can induce autophagy of bladder cancer T24 cells and the possible mechanism, and to observe the relationship between outophagy and apoptosis.Methods MTT assay was applied to investigate the effects of various concentration of cisplatin( 0 , 10 , 20 and 40 μg/mL) on T24 survival.TEM was performed to detect the autophagosome formation .Western blot assay was used to analyze the expression changes of LC3-Ⅱ, P62 and extracellular signal-regulated kinase ( ERK1/2 ) and p-ERK at the protein level.The effects of autophagy on the survival and apoptosis of bladder cancer cells were investiga-ted.Results DDP observably inhibited proliferation of bladder cancer cells in a dose-dependent manner ( P<0.05), the 50% inhibiting concentration(IC50) was (30.3 ±2.4)μg/mL;DDP induced autophagy of bladder cancer cells, observably increased autophagosome induced by DDP; up-regulated expression levels of LC3-Ⅱproteins ( P<0.05 ) , down-regulated expression of P62 proteins ( P<0.05 );DDP increased the protein level of p-ERK (P<0.05); The inhibitor of ERK pathway U0126 inhibited DDP-induced autophagy, as evidenced by decrease in the expression of LC3-Ⅱproteins ( P<0.05 ) .After inhibition of autophagy by WTM in DDP-treated cells, cell viability was obviously decreased and apoptosis was increased (P<0.05);DDP combined with WTM observably enhanced cleavage of poly ADP-ribose polymerase 1 ( PARP-1 ) and cleaved-caspase-3 which is apop-tosis related proteins ( P<0.05 ) .Conclusions Autophagy can protect T24 cells against ciplatin-induced apop-tosis, the possible mechanism of autophagy is the ERK signaling pathway is activated .

Expressions of ERK and p-ERK in advanced prostate cancer / 中华男科学杂志

Objective@#To investigate the expressions of extracellular signal-regulated kinase (ERK) and p-ERK in benign and malignant prostate tissues, and whether it can be used as a marker for the prognosis of advanced prostate cancer (PCa).@*METHODS@#Using immunohistochemical Envision, we detected the expressions of ERK1/2 and p-ERK1/2 in 20 cases of benign prostatic hyperplasia (BPH) and 40 cases of advanced PCa and analyzed their correlation with PCa metastasis, Gleason score, PSA level, and prognosis.@*RESULTS@#The expression of ERK1/2 was remarkably higher in the advanced PCa than in the BPH cases (82.5% vs 55%, P5 yr, and survival ≤ 5 yr groups were 61.9%, 89.5%, 57.9%, and 90.5%, respectively, with statistically significant differences among these groups (P<0.05).@*CONCLUSIONS@#ERK1/2 and p-ERK1/2 proteins are highly expressed in advanced PCa and p-ERK1/2 is associated with the metastasis and prognosis of advanced PCa.

Alteration of Akt, p-Akt, ERK, and p-ERK Proteins Expression in the Kidney of Hypokalemic Rat / 체질인류학회지

Hypokalemia causes metabolic alkalosis and morphological changes of the kidney. K⁺ balance is regulated not only by ion channels or pump gene, but also by various genes including NF-E2-related factor 2 (Nrf2). Previous study suggested the possibility that Akt and ERK kinase may be involved in Nrf2 transcriptional gene activation. In present study, we investigate the alterations of Akt, p-Akt, ERK, p-ERK protein in both normal kidney and K⁺-deficient diet kidney using Western blot analysis, and immunohistochemisrty. Our western blot data showed that the expression of Akt and p-Akt was increased gradually in K⁺-depleted diet (from 1W-3W) compared to normal group. The expression of ERK and p-ERK was markedly increased in K⁺-depleted diet 2W in comparison with normal group. Based on our immunostaining results, Akt protein immunoreactivity was prominently increased in outer medullary collecting duct, especially in K⁺-depleted diet 2 weeks. The localization of p-Akt proteins in K⁺-depleted groups was not different from normal group, but the immunoreactivity was significantly increased in distal convoluted tubule, macula densa and outer medullary thick ascending limb in K⁺-depleted diet 1 and 2 weeks groups. ERK protein immunoreactivity was prominently increased in outer medullary collecting duct, especially in K⁺-depleted diet 2 and 3 weeks. The localization of p-ERK proteins in K⁺-depleted groups was not different from normal group, but the immunoreactivity was prominently increased in the nucleus of outer medullary collecting duct especially in K⁺-depleted diet 2 weeks. Taken together, we suggest that the expression of p-Akt was gradually increased in K⁺-depleted groups of kidney, but the expression of p-ERK was markedly increased in K⁺-depleted diet 2 week group. Hence, the promotion of AKT and ERK phosphorylation in hypokalemic condition may be involved in the regulation of ion channels, ion transporters and subsequent intracellular signal transduction.

Effects of DNMT1-siRNA on the pain behavior and the expression of SOCS1,p-ERK,p-CERB in CCI rats / 临床麻醉学杂志

Objective To investigate the effects of DNMT1 on neuropathic pain behavior and neuropathic pain modulation.Methods Thirty-two male SD rats, weighing 200-250 g, were randomly assigned into 4 groups (n =8 each):sham operation group (group S),chronic constrictive injury group (group CCI),CCI+ DNMT1-siRNA group (group CDS),CCI+ control-siRNA group (group CCS).Group CDS were intrathcally injected of DNMT1-siRNA (2 μg/10 μl),and group CCS were intrathcally injected of control-siRNA 7,8,9 days after operation.Mechanical withdrawal threshold (MWT)and thermal withdrawal latency (TWL)were measured before operation and on day 3,5,7,9,12,14 after operation.The rats were then sacrificed and L4-L6 segments of the spinal cord were removed for determination of SOCS1,p-ERK,p-CREB expression using Western blot on day 14.Results Compared with group S,MWT and TWL in group CCI and CCS were significantly decreased on day 3,5,7,9,12,14 after operation (P <0.05).Compared with group CCS,MWT and TWL in group CDS were significantly increased on day 9,12,14 after operation (P < 0.05 ). Compared with group S and CDS,SOCS1 was significantly downregulated,p-ERK and p-CREB were significantly upregulated in group CCI and CCS (P <0.05 ).Conclusion Intrathcal injection of DN-MT1-siRNA significantly relieves neuropathic pain by upregulating SOCS1,downregulating p-ERK and p-CREB in rats spinal cords.

Ursolic Acid Inhibition on Human Hepatic Stellate Cells Proliferation through PDGF-ERK Signaling Pathway / 世界科学技术-中医药现代化

This study was aimed to investigate the effects of ursolic acid on human hepatic stellate cells (HSC-LX-2) proliferation and its mechanism.Different doses of ursolic acid were incubated with HSC-LX-2 cellin vitrof or 48 h.MTT was used for the detection of HSC-LX-2 cell proliferation.The expressions of PDGF-ERK signaling pathway associated proteins were measured by western blot.The results showed that the proliferation of HSC- LX-2 cells was inhibited by ursolic acid in a dose-dependent manner.The inhibition rate of 20,30 and 40μmol·L-1 of ursolic acid was 9.1%,42.3% and 62.6%,respectively.The IC50 was 35.2μmol·L-1.After incubated with ursolic acid for 48 h,protein levels of PDGF-R and p-ERK in 30 and 40μmol·L-1 group were significantly decreased when compared with the normal group (P<0.05 orP<0.01),except the ERK protein.It was concluded that ursolic acid can inhibit HSC-LX-2 cell proliferation.Its mechanism may be related to the blockage of PDGF-ERK signaling pathway.

EZH2 plays a role in HSC-T6 cell proliferation and activation affecting MAPK/ERK and PI3 K/AKT pathway / 中国药理学通报

Aim To investigate the effects of cell pro-liferation and activation in HSC-T6 cells by inhibiting the expression of EZH2 , and its partial relevant mech-anism. Methods By introducing the inhibitor DZNep in activated HSC-T6 cells stimulated by TGF-β1 , the protein expression levels of EZH2, p-ERK, p-AKT andα-SMA were detected by Western blot. The siRNA targeting EZH2 was designed and synthesized according to its nucleotide sequence, and their corresponding ex-pression vectors were constructed and transfected into HSC-T6 cells with LipofectamineTM 2000. The prolifer-ation of HSC-T6 cells was determined by MTT. And the protein expression levels of EZH2, p-ERK, p-AKT and α-SMA were measured by Western blot. Results By introducing the inhibitor DZNep in activated HSC-T6 cells stimulated by TGF-β1 , it effectively de-creased the protein levels of EZH2 and also the protein levels of p-ERK, p-AKT and α-SMA. By introducing EZH2-siRNA in activated HSC-T6 cells, it effectively inhibited the cell proliferation, and also the protein levels of EZH2, p-ERK, p-AKT andα-SMA. Conclu-sion Silencing EZH2 expression inhibits HSC-T6 cell proliferation and activation, and EZH2 may be a poten-tial therapeutic target gene for hepatic fibrosis.

Degenerative Changes of Auditory Functions and Age -related Expression of p-ERK1/2 in the Cochlea of the Senescence Accelerated Mouse / 听力学及言语疾病杂志

Objective To investigate degenerative changes of auditory functions and age -related expression of phosphorylated extracellular signal -regulated protein kinases1/2(p-ERK1/2) in the cochlea of the senescence accelerated mouse .Methods The 3 ,5 ,7 months old mice were selected for the study and each group had 6 mice . The 8 kHz tone burst auditory thresholds and age -related expression of p -ERK1/2 in the cochlea were studied in the senescence accelerated mouse/prone 8(SAMP8) at 3 ,5 ,7 months .The expression of p -ERK1/2 was analyzed by the optical density of immunohistochemical staining .Results For the auditory function evaluation :The SAMP 8 developed a progressive hearing loss at 8 kHz which showed an age -related significant increase (P< 0 .05) .The ABR thresholds in 3 ,5 ,7 months old groups in the left ear were 31 .817 ± 1 .228 ,54 .329 ± 1 .459 ,58 .330 ± 1 .252 dB SPL ,respectively .In the right ears ,the ABR threshold were 32 .474 ± 1 .041 ,53 .485 ± 1 .385 ,57 .842 ± 1 .173 dB SPL ,respectively .p-ERK1/2 protein expressed in the cochlea of the SAMP8 throughout the development sta‐ges ,which developed an age-related significant decrease (P<0 .05) .The average optical density of p -ERK1/2 in the spiral ganglion cells in the 3 ,5 ,7 months old mice were 0 .699 7 ± 0 .018 8 ,0 .621 5 ± 0 .014 7 ,0 .575 3 ± 0 .015 5 ,respectively .In the hair cells ,they w ere 0 .651 9 ± 0 .025 2 ,0 .591 2 ± 0 .010 2 ,0 .559 3 ± 0 .006 7 respec‐tively .Conclusion The expression level of p -ERK1/2 protein decreases when the SAMP 8 develops a progressive hearing loss .This indicates that p-ERK1/2 protein probably has relationship with maintaining functional status of the cochlea and the auditory formation .

Effect of C3G gene on apoptosis and proliferation of H9C2 cardiomyocytes / 解放军医学杂志

ObjectiveTo study the effect of C3G gene on apoptosis and proliferation of H9C2 cardiomyocytes and its mechanism. MethodsThe RNA lentivirus was constructed, and pCXN2-Flag plasmid (empty plasmid) and pCXN2-Flag-hC3G plasmid (over-expressed human C3G mRNA) were purchased. H9C2 cardiomyocytes were respectively infected and transfected with blank reagent, negative lentivirus, C3G siRNA lentivirus, C3G siRNA lentivirus+pCXN2-Flag plasmid and C3G siRNA lentivirus+pCXN2-Flag-hC3G plasmid with stochastic method. Thus the experiments were randomly divided into five groups, namely blank group, negative control group, C3G silence group, C3G silence+empty plasmid group, and C3G silence+C3G overexpression group. Seventy two hours after plasmid transfection, the expression of C3G mRNA was detected by PT-RCR, cell apoptosis was determined by flow cytometry, cell proliferation rate was determined by MTT, and the protein levels of C3G, p-ERK1/2, Bax and Flag were determined by Western blotting. Results As screened by puromycin, it was found that more than 85% of the cells in negative control group and C3G silence group were labeled with green fluorescent protein, showing that more than 85% of the cells were infected with lentivirus. Compared with blank group and negative control group, the expressed Bax protein and cell apoptosis rate were increased significantly (P<0.01, P<0.05), and the expression levels of C3G mRNA, C3G protein and p-ERK1/2 protein and the cell proliferation rate were remarkably decreased in C3G silence group and C3G silence+empty plasmid group (P<0.01, P<0.05); Compared with C3G silence group and C3G silence+empty plasmid group, the expression level of Bax protein and the cell apoptosis rate were decreased obviously (P<0.01, P<0.05), while the expression levels of C3G mRNA, C3G protein and p-ERK1/2 protein and the cell proliferation rate were remarkably increased in C3G silence+C3G overexpression group (P<0.01, P<0.05). Conclusion C3G gene silence can induce apoptosis and inhibit proliferation in H9C2 cardiomyocytes, and overexpression of C3G gene can reverse the effects of C3G gene silence affecting in H9C2 cardiomyocytes, characterized by a reduction of apoptosis rate and promotion of proliferation, and they may be related to p-ERK1/2 protein and pro-apoptotic molecule Bax.

The Effects ofβ-Sheet Breaker Peptide H102 on ERK Signal Transduction Pathway in Brain of PAP Double Transgenic Mice / 天津医药

Objective To investigate the activation of β-sheet breaker peptide H102 on ERK signal transduction pathway in brain of PAP double transgenic mice. Methods PAP double transgenic mice were randomly divided into model group and H102 treatment group (n=10 for each group). A group of C57BL/6J mice with the same genetic background was served as controls. H102 (5.8 mg/kg) 5 μL was infused by intranasal administration to mice in H102 treatment group, and equal volume of blank solution of H102 (chitosan, BSA) was given to mice in control group and model group. The ability of spatial reference memory was tested by Morris water maze after 30 days of treatment. Then immunohistochemistry tests and Western blot technique were used to detect the content of RAS, P-MEK and P-ERK proteins in mouse brain. Results (1) The ability of learning and memory was significantly lower in model group than that of control group. The ability of learning and memory was significantly improved in treatment group than that in model group (P<0.05). (2) The contents of RAS, P-MEK and P-ERK in mouse brain were significantly lower in model group than those of control group, and these protein ex-pressions were significantly increased in treatment group than those in model group (P<0.01). Conclusion β-sheet break-er peptide H102 can activate ERK signal transduction pathway in brain of PAP double transgenic mice, increase PAS, P-MEK and P-ERK levels in nerve cells, and improve the ability of learning and memory in PAP mice.

Study on the intervention time windows of cell apoptosis in acute liver injury in mice / 中华急诊医学杂志

Objective To study the proliferation and apoptosis of related proteins in pathological liver tissues of alcohol-induced mice,and establish a model and time-evolution rule of liver cell apoptosis,which can be used to guide the clinical treatment of acute alcoholic liver injury.Methods A total of 30 male KM mice were fed in a clean grade animal room at the Capital Medical University and then randomly (random number) separated into two groups.The 10 mice in the normal group were fed without ethanol,while the other 20 mice in the experimental group were given a one-time grant of 50％ ethanol (12 mL/kg) by gavage.The mice in the experimental group were killed at two time points,6 h for 10 mice and 12 h for the other 10,after the intragastric administration.Hematoxylin and eosin (HE) staining was used to observe the morphological changes of liver in mice.The concentrations of T-ERK,p-ERK,PKC,p-PKC and caspase-3 were determined by the Western-blot method.The data were analyzed by Analysis of variance (ANOVA) method using statistical software SPSS 11.5 and criterion P ＜ 0.05 is chosen to determine differences that are statistically significant.Results By observing the behavioral changes and morphological indexes of mice,we confirmed the success of the model for acute alcoholic liver injury.During the process of re-building the model,no mice died.The mice in the experimental group appeared in drunken states,such as sleepiness and slowness of movement.Compared to the normal group,the experimental subgroup at the 6 h point showed no difference statistical significant; while the experimental subgroup at the 12 h point showed obvious histological changes in tissues,including the disorder of hepatic lobule structure and fatty vacuolization of hepatocytes.At the same time,in the experimental subgroup at the 12 h point,both P-ERK and P-PKC significantly decreased [(2.41 ±0.38),(0.97 ±0.25),F=4.82,P＜0.05; (0.16 ±0.00),(0.08 ± 0.01),F =29.63,P ＜ 0.05],but caspase-3 significantly increased [(0.30 ± 0.02),(0.11 ± 0.01),F =34.38,P ＜ 0.05].Conclusions In mice after intragastric administration of large doses of alcohol,the hepatic cell apoptosis appeared mainly after 6 h but before 12 h,therefore 6 ～ 12 h might be the time window to inhibit the cell apoptosis of mice' s acute liver injury from alcohol induction.

Altered APP Carboxyl-Terminal Processing Under Ferrous Iron Treatment in PC12 Cells

Amyloid-beta peptide (Abeta), generated by proteolytic cleavage of the amyloid precursor protein (APP), plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). The key step in the generation of Abeta is cleavage of APP by beta-site APP-cleaving enzyme 1 (BACE1). Levels of BACE1 are increased in vulnerable regions of the AD brain, but the underlying mechanism is unknown. In the present study, we reported the effects of ferrous ions at subtoxic concentrations on the mRNA levels of BACE1 and a-disintegrin-and-metalloproteinase 10 (ADAM10) in PC12 cells and the cell responses to ferrous ions. The cell survival in PC12 cells significantly decreased with 0 to 0.3 mM FeCl2, with 0.6 mM FeCl2 treatment resulting in significant reductions by about 75%. 4,6-diamidino-2-phenylindole (DAPI) staining showed that the nuclei appeared fragmented in 0.2 and 0.3 mM FeCl2. APP-alpha-carboxyl terminal fragment (APP-alpha-CTF) associations with ADAM10 and APP-beta-CTF with BACE1 were increased. Levels of ADAM10 and BACE1 mRNA increased in response to the concentrations of 0.25 mM, respectively. In addition, p-ERK and p-Bad (S112, S155) expressions were increased, suggesting that APP-CTF formation is related to ADAM10/BACE1 expression. Levels of Bcl-2 protein were increased, but significant changes were not observed in the expression of Bax. These data suggest that ion-induced enhanced expression of AMDA10/BACE1 could be one of the causes for APP-alpha/beta-CTF activation.

Relationship between CD158j expression and phosphorylated ERK levels in CD4 + CD28null T cells in cerebral infarction patients with carotid atherosclerosis / 中华微生物学和免疫学杂志

Objective To investigate the relationship between CD158j expression and phosphorylated ERK (p-ERK) in CD4+ CD28null T cells in cerebral infarction (CI) patients- with carotid atherosclerosis and its effects on carotid atherosclerotic plaque stability. Methods Percentage of peripheral CD4+ CD28null and the expression of CD158j and perform on CD4+ CD28null cells was analyzed with flow cytometry in 106 CI patients with carotid atherosclerosis, 33 CI patients with normal carotid arteries and in 50 normal controls, respectively; p-ERK expression was assayed with flow cytometry in 36 CI patients with unstable plaque, and serum IFN-γ was detected with ELISA. The intima-media thickness (IMT) of bilateral carotid arteries in all subjects was confirmed by the colour Doppler ultrasonograph imagingResults Percentage of the CD4+ CD28null T cells, expression of CD158j and perform on CD4+ CD28null T cells and the serum IFN-γ levels was dramatically higher in CI patients than that in normal controls, respectively (all P <0.01), which was decreased in an order of CI patients with patients with unstable plaque, stable plaque, carotid artery IMT and with normal carotid artery. A strong positive correlation was observed between the CD158j expression and degree of p-ERK in CI patients with unstable plaque (P < 0. 01). Conclusion CD4+ CD28null T cells were significantly increased in CI patients with carotid atherosclerosis. CD158j might up-regulate p-ERK expression and induce the proliferation of the CD4+ CD28nullT cells; consequently, higher cytokine production such as IFN-γ produced by CD4+ CD28null T cells may cause the formation of unstable plaque.

Effect of phosphorylated-ERK1/2 on NF-κB p65 expression in substantia nigra of mice with MPTP-induced Parkinson's disease / 第二军医大学学报

Objective To mvestigate the effect of phospholated-ERKl/2 on NF-κB p65 expresson nn the substania nigra(SN) of l-msthyi-4-phenyi-l,2, 3, 6-tetrahydropyeidine (MPTP)-induced mouse model of Parkinson's disease(PD). Methods PD mouse model was induced by MPTP and the behavoor of mouse was observed. Immunohistochemistry and Western bloiting analysis were used to observe the changes in expression of tyrosine hydroxylase (TH), NF-κB p65 and p-ERKl/2 in the SN of midbrain. Meanwhite, the above changes were also observed after treatment with U0126, a specific inhibitor of ERK. Results 1 h after the third MPTP administration, there were much more p-ERKl/2 positive cells than NF-κB p65 positive cells in the SN. 24 h after the fifth injection of MPTP, NF-κB p65 positive cells were significantly increased and p-ERKl/2 positive celiswere decreased, accompanted by marked loss of TH positive neurons. The above changes were greatly alleviated in animais treated with U0l26. Conclusion ERKl/2 pathway may regulate NF-κB p65 activation in MPTP-induced mouse model of Parkinson's disease, which leads to loss of dopamine neurons.

Effect of ERK1/2/c-Fos signal pathway on angiotensin-(1-7) inhibiting proliferation of rat glomerular mesangial cell strain induced by angiotensin Ⅱ / 中国病理生理杂志

AIM:To investigate the effect of ERK1/2/c-Fos signal pathway during angiotensin-(1-7)inhibiting proliferation of rat glomerular mesangial cell strain(GMCS)induced by angiotensin Ⅱ.METHODS:Rat glomerular mesangial cells(GMC)were co-cultured with angiotensin Ⅱ and different doses of angiotensin-(1-7).The numbers of GMC were evaluated by crystal violet staining.The amounts of p-ERK1/2 and c-Fos expressions were detected by Western blotting.RESULTS:Angiotensin-(1-7)showed its inhibitory effects on GMC number increasing induced by angiotensin Ⅱ as well as the amounts of p-ERK1/2 and c-Fos expressions in a concentration dependent manner.CONCLUSION:ERK/c-Fos signal pathway is involved in the inhibitory effects of angiotensin-(1-7)on angiotensin Ⅱ-induced GMC proliferation.