Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase...Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase (p38 MAPK) pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin (30 mg/kg) for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.展开更多
AIM To investigate the antioxidant effect of caffeic acid phenethyl ester (CAPE) in hepatic stellate cell-T6 (HSC-T6) cells cultured in vitro and the potential mechanisms. METHODS HSC-T6 cells were cultured in vitro a...AIM To investigate the antioxidant effect of caffeic acid phenethyl ester (CAPE) in hepatic stellate cell-T6 (HSC-T6) cells cultured in vitro and the potential mechanisms. METHODS HSC-T6 cells were cultured in vitro and treated with various concentrations of CAPE for 24, 48 and 72 h, respectively. Cell proliferation was investigated using the MTT assay, and cell ultrastructural alterations were observed by transmission electron microscopy. Flow cytometry was employed to investigate the effects of CAPE on apoptosis and the levels of reactive oxygen species in HSC-T6 cells cultured in vitro. An enzyme immunoassay instrument was used to evaluate antioxidant enzyme expression. The effect on alpha-smooth muscle actin was shown using immunofluorescence. Gene and protein levels of Nrf2, related factors, and mitogen activated protein kinases (MAPKs), in HSC-T6 cells were detected using RT-PCR and Western blot, respectively. RESULTS CAPE inhibited the proliferation and activation of HSC-T6 cells cultured in vitro. CAPE increased the antioxidant levels and the translocation of Nrf2 from the cytoplasm to the nucleus in HSC-T6 cells. Moreover, the phosphorylation of MAPKs in cells decreased in response to CAPE. Interestingly, CAPE-induced oxidative stress in the cells was significantly attenuated by pretreatment with MAPKs inhibitors. CONCLUSION CAPE inhibits cell proliferation and up-regulates the antioxidant levels in HSC-T6 cells partly through the Nrf2-MAPKs signaling pathway.展开更多
We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis fac...We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.展开更多
Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultu...Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.展开更多
Objective To study the cardioprotective effects of hypoxic preconditioning (HPC) on aged rat ventricular myocytes and the cellular mechanism of protection Methods In the model of hypoxia/reoxygenation (H/R) of ...Objective To study the cardioprotective effects of hypoxic preconditioning (HPC) on aged rat ventricular myocytes and the cellular mechanism of protection Methods In the model of hypoxia/reoxygenation (H/R) of isolated ventricular myocytes of aged rat, the effects of HPC on aged rat ventricular myocytes against lethal H/R stimulated ischemia/reperfusion (I/R) injury 24 hours later and the changes of mitogen activated protein kinase (MAPK) system were observed in the present study Results HPC attenuated the lactate dehydrogenase (LDH) release and ATP depletion in myocytes and increased the viability of myocytes It was also found that MAPK and its down stream kinase—S6 kinase were also activated after HPC Conclusion There is delayed cardioprotection in cardiac myocytes of aged rat and the cellular mechanism underlying might involve the activation of MAPK system展开更多
Objective:To investigate the effect of Dan-gua Fang(丹瓜方) on adenosine 5’-monophosphate(AMP) activated protein kinase(AMPK) α expression in liver and subsequent improvement of glucose and lipid metabolism.M...Objective:To investigate the effect of Dan-gua Fang(丹瓜方) on adenosine 5’-monophosphate(AMP) activated protein kinase(AMPK) α expression in liver and subsequent improvement of glucose and lipid metabolism.Methods:Forty 13-week-old diabetic Goto-Kakizaki(GK) rats were randomly divided into model,Dan-gua Fang,metformin and simvastatin groups(n=10 for each),and fed high-fat diet ad libitum.Ten Wistar rats were used as normal group and fed normal diet.After 24 weeks,liver expression of AMPK α mRNA was assessed by real-time PCR.AMPK α and phospho-AMPK α protein expression in liver was evaluated by Western blot.Liver histomorphology was carried out after hematoxylin-eosin staining,and blood glucose(BG),glycosylated hemoglobin A1c(HbA1c),food intake and body weight recorded.Results:Similar AMPK α mRNA levels were found in the Dan-gua Fang group and normal group,slightly higher than the values obtained for the remaining groups(P〈0.05).AMPK α protein expression in the Dan-gua Fang group animals was similar to other diabetic rats,whereas phospho-AMPK α(Thr-172) protein levels were markedly higher than in the metformin group and simvastatin group(P〈0.05),respectively.However,phosphor-AMPKa/AMPK α ratios were similar in all groups.Dan-gua Fang reduced fasting blood glucose with similar strength to metformin,and was superior in reducing cholesterol,triglycerides,high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin.Dan-gua Fang decreases plasma alanine aminotransferase(ALT) significantly.Conclusion:Dan-gua Fang,while treating phlegm-stasis,could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet,and effectively protect liver histomorphology and function.This may be partly explained by increased AMPK expression in liver.Therefore,Dan-gua Fang might be an ideal drug for comprehensive Intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.展开更多
Obejctives To study mitogen activated protein kinase (MAPKs) activation in fibroblast like synoviocytes (FLS) of rheumatoid arthritis (RA) under the stimulation of IL 1β, and to elucidate the role of protein tyro...Obejctives To study mitogen activated protein kinase (MAPKs) activation in fibroblast like synoviocytes (FLS) of rheumatoid arthritis (RA) under the stimulation of IL 1β, and to elucidate the role of protein tyrosine kinase (PTK) in the activation of MAPKs Methods Primary cultures of RA FLS were used Western blot was applied to examine transient changes in protein tyrosine phosphorylation status and MAPKs activation in RA FLS stimulated with IL 1β at various doses, and over different periods Genistein, the specific PTK inhibitor, was used to evaluate the inhibitory role in activation of MAPKs by IL 1β Results IL 1β transiently increased protein tyrosine phosphorylation, and activated the MAPKs cascades (mainly ERK 2, JNK 2 and P 38 ) in RA FLS There was no obvious difference in MAPKs activation among different doses of IL 1β (1?IU/ml,10?IU/ml, 100?IU/ml), but the peak activation of ERK 2, JNK 2 and P 38 took place at 5?min, 15?min and 1?min, respectively, after stimulation with IL 1β The activation of ERK 2 was inhibited by genistein, but the inhibitory role on that of JNK and P 38 was relatively weak Conclusions During signal transduction of IL 1β in RA FLS, tyrosine phosphorylation was increased transiently, the MAPKs cascade was activated in a few minutes, and there was heterogenicity in the activation among three subfamily members PTK had a role in the activation of ERK, but had weak effects on that of JNK and P 38展开更多
Background Acute lung infection due to Pseudomonas aeruginosa (P. Aeruginosa) is a serious problem, especially in patients with structural lung conditions or immune compromised hosts, leading to an overwhelming thre...Background Acute lung infection due to Pseudomonas aeruginosa (P. Aeruginosa) is a serious problem, especially in patients with structural lung conditions or immune compromised hosts, leading to an overwhelming threat with a high risk of morbidity and mortality. As an outcome of infection, fibrosis can be linked with chronic lung diseases. But some fibrotic manifestations, such as an irreversible decrease of lung function and fibrous bands seen on chest imaging, have been found after an acute infection with P. Aeruginosa. Fibrogenesis/remodeling resulting from acute lung infection by P.aeruginosa is rarely reported. This study was designed to explore the relation between fibrogenesis/remodeling and acute infection by P. Aeruginosa in vitro. We used flagellin protein from P. Aeruginosa, a key initiator of acute P.aeruginosa lung infection, to elucidate mechanisms by which acute lung infection with P. Aeruginosa can cause fibrogenesis/remodeling.Methods We studied the effect of flagellin from P. Aeruginosa (flagellin for short) on the transforming growth factor beta 1 (TGF-β1) and interleukin-8 (IL-8) expression, and the possible involvement of the signaling pathway, tumor necrosis factor receptor-associated factor 6 (TRAF6)/mitogen activated protein kinase (MAPK) pathway. Flagellin was purified from the P. Aeruginosa standard strain, PAO1. Normal bronchial epithelial cells BEAS-2B were challenged with different concentrations of flagellin, and cell viability assessment was performed by cell counting kit-8. BEAS-2B cells were incubated with flagellin with the specific MAPK inhibitors or TRAF6 siRNA. Cell lysates and the cultured supernatant were collected. The level of TGF-β1 and IL-8 were detected by enzyme-linked immunosorbant assay (ELISA). Western blotting was used to detect the protein levels of MAPK signal proteins p38, c-Jun NH2-terminal kinase (JNK) and extracellular regulated kinase (ERK).Results Expression of TGF-β1 in BEAS-2B cells was elevated by flagellin vs. Control groups ((104.3±20.8) vs.(44.6±4.4) pg/ml (P 〈0.01)) and was ablated by either p38 or JNK inhibitors compared with flagellin treatment ((45.1±18.8)vs. (104.3±20.8) pg/ml and (48.1±20.8) vs. (104.3±20.8) pg/ml, respectively (P 〈0.05)). Flagellin also elevated the expression of IL-8 in BEAS-2B cells vs. The control groups ((554.9±57.7) vs. (51.4±2.2.9) pg/ml (P 〈0.01)), and p38 MAPK inhibitors weaken the expression by flagellin ((301.1 ±155.1) vs. (554.9±57.7) pg/ml (P 〈0.05)). Western blotting revealed that all three MAPK proteins, p38, JNK and ERK were activated by flagellin challenge in an early phase, respectively in 15 minutes (P 〈0.01), 30 minutes (P 〈0.01) and 15 minutes (P 〈0.01). TRAF6 siRNA which decreased expression of TRAF6, altered the activation of JNK, p38, and ERK following flagellin treatment, but its influence on the expression of TGF-β1 and IL-8 has no statistical significance.Conclusions Flagellin from P. Aeruginosa PAO1 induces TGF-β1 expression in normal bronchial epithelial cells,BEAS-2B, through the MAPK signal cascade in vitro. It suggests that the fibrogenesis/remodeling process may be initiated from an early stage of acute lung infection due to P. Aeruginosa.展开更多
Background Complement receptor type 2 (CR2) is the receptor for C3d and C3dg and for Epstein Barr virus The aim of our study was to explore whether CR2 can independently mediate the activation of mitogen activated pro...Background Complement receptor type 2 (CR2) is the receptor for C3d and C3dg and for Epstein Barr virus The aim of our study was to explore whether CR2 can independently mediate the activation of mitogen activated protein kinases (MAPKs, including ERK, JNK, and p38MAPK), and to highlight the molecular mechanism of CD 4 + cell deletion in AIDS Methods HOS cells (HOS CR2) and HOS CD4 cells (HOS CD4CR2) stably expressing CR2 were established and then identified by FACS and Western blotting Activation and blocking tests of MAPKs were assessed by Western blot Cell proliferation was determined using Cell Titer 96 Aqueous One Solution Reagent Results FACS results showed that the positive rates of HOS CR2 and HOS CD4CR2 cells were greater than 96%, and Western blot showed that the CR2 expression levels on HOS CR2 and HOS CD4CR2 cells were high Activation and blocking tests of MAPKs (ERK, JNK, and p38MAPK) were carried out in HOS CR2, HOS CD4, and HOS CD4CR2 cells The activation of MAPKs in HOS CR2 cells stimulated with PMA (100 ng/ml) and NHS (10%) was identical The activation of MAPKs increased at 5 minutes, reached a peak at 10 minutes, and decreased to baseline within 30 minutes, all in a time dependent manner; the activation of MAPKs was blocked by anti CR2 McAb, PD98059 (inhibitor of ERK), and Wortmanin (inhibitor of PI 3K), respectively In HOS CD4 cells, MAPKs were activated by HIV gp160 In HOS CD4CR2 cells, MAPK activation was induced by HIV gp160, 10% NHS, and HIV gp160+10%NHS; phosphorylation of p38MAPK was dramatically induced by HIV gp160+NHS, and lasted for 1 hour The cell proliferation results showed that HIV gp160 inhibited the proliferation of HOS CD4 and HOS CD4CR2 cells ( P <0 01) and that NHS enhanced the effect of HIV gp160 ( P <0 01) Conclusions The activation of MAPKs is independently mediated by CR2 and that anti CR2 McAb, PD98059, and Wortmanin block the activation of MAPKs, respectively The results of the signal transduction and cell proliferation assays of HOS CD4CR2 cells show that CR2 plays a role in the pathogenesis of HIV infection, especially in the inhibition of CD 4 + cell proliferation展开更多
Very few selected species of primates are known to be capable of entering torpor. This exciting discovery means that the ability to enter a natural state of dormancy is an ancestral trait among primates and, in phylog...Very few selected species of primates are known to be capable of entering torpor. This exciting discovery means that the ability to enter a natural state of dormancy is an ancestral trait among primates and, in phylogenetic terms, is very close to the human lineage. To explore the regulatory mechanisms that underlie primate torpor, we analyzed signal transduction cascades to discover those involved in coordinating tissue responses during torpor. The responses of mitogen-activated protein kinase(MAPK) family members to primate torpor were compared in six organs of control(aroused) versus torpid gray mouse lemurs, Microcebus murinus. The proteins examined include extracellular signal-regulated kinases(ERKs), c-jun NH2-terminal kinases(JNKs), MAPK kinase(MEK), and p38, in addition to stress-related proteins p53 and heat shock protein 27(HSP27). The activation of specific MAPK signal transduction pathways may provide a mechanism to regulate the expression of torpor-responsive genes or the regulation of selected downstream cellular processes. In response to torpor, each MAPK subfamily responded differently during torpor and each showed organ-specific patterns of response. For example, skeletal muscle displayed elevated relative phosphorylation of ERK1/2 during torpor. Interestingly, adipose tissues showed the highest degree of MAPK activation. Brown adipose tissue displayed an activation of ERK1/2 and p38, whereas white adipose tissue showed activation of ERK1/2, p38, MEK, and JNK during torpor. Importantly, both adipose tissues possess specialized functions that are critical for torpor, with brown adipose required for non-shivering thermogenesis and white adipose utilized as the primary source of lipid fuel for torpor. Overall, these data indicate crucial roles of MAPKs in the regulation of primate organs during torpor.展开更多
Ninety male Wistar rats were selected under the "Guide for the Care and Use of Laboratory Animals" for skin-muscle wound models. Three groups of animals were examined respectively for inoculation of inhibitor of p38...Ninety male Wistar rats were selected under the "Guide for the Care and Use of Laboratory Animals" for skin-muscle wound models. Three groups of animals were examined respectively for inoculation of inhibitor of p38 MAPK (mitogen activated protein kinase) SB 203580 and JNK inhibitor SP 600125, and a control. Light microscopy, immunohistochemistry, and tensometry revealed that the inhibition of p38 or JNK cascades have modified the formation of the connective tissue scar. The degree of connective tissue growth in the area of surgical wound had been significantly reduced by the end of observation (30 d) as the SB 203580 was applied (% volume of collagen 43.60 (41.05 - 60.15) vs. 73.54 (66.87 - 78.01) in control, p = 0.002). Conversely, when we have applied the JNK blocker, the density of collagen in scar tissue increased (78.14 (72.77 - 81.14), p = 0.022 vs. control). SB203580 inhibits the expression of p38, c-Jun and c-Fos. When we have used the JNK blocker, the expression of c-Fos and c-Jun decreased, but the expression of p38 increased. This determines the high functional activity of fibroblasts after using SP 600125. Obtained results show the importance of studying regulators of cell differentiation as potential drugs, which significantly affect the outcome of the pathological processes.展开更多
Background The plasma concentration of very low density lipoprotein (VLDL) is negatively correlated to renal function in glomerular diseases. Effects of VLDL on renal function have been partially attributed to the p...Background The plasma concentration of very low density lipoprotein (VLDL) is negatively correlated to renal function in glomerular diseases. Effects of VLDL on renal function have been partially attributed to the proliferation of mesangial cells. This study examined the potential role of the p42/44 mitogen activated protein kinase (MAPK) in mesangial cell proliferation induced by VLDL. Methods Mesangial cells were treated with VLDL at different concentrations or for different time. The cell cycle of the mesangial cells was analyzed by Xl-r assay and flow-cytometry; MAPK activity was also assayed. In some experiments, cells were treated with VLDL together with or without 0.1 pmol/L PD 98059. Results Ten to 500 μg/ml VLDL stimulated the proliferation of mesangial cells cultured in vitro in a concentration-dependent manner. The effect was associated with an increase in p42/44 MAPK activity. Increased proliferation of mesangial cells by VLDL was significantly attenuated by PD98059, a specific p42/44 MAPK inhibitor. Conclusion These results indicate that the p42/44 MAPK pathway is an important regulator of mesangial cell proliferation and of renal functions.展开更多
Lysophosphatidic acid (LPA) is a pleiotropic lipid med-iator that promotes motility, survival, and the synthesis of chemokines/cytokines in human fbroblast-like syno-viocytes (FLS) from patients with rheumatoid ar...Lysophosphatidic acid (LPA) is a pleiotropic lipid med-iator that promotes motility, survival, and the synthesis of chemokines/cytokines in human fbroblast-like syno-viocytes (FLS) from patients with rheumatoid arthritis. LPA activates several proteins within the mitogen acti-vated protein (MAP) kinase signaling network, including extracellular signal-regulated kinases (ERK) 1/2 and p38 MAP kinase (MAPK). Upon docking to mitogen and stress-activated kinases (MSKs), ERK1/2 and p38 MAPK phosphorylate serine and threonine residues within its C-terminal domain and cause autophosphorylation of MSKs. Activated MSKs can then directly phosphorylate cAMP response element-binding protein (CREB) at Ser133 in FLS. Phosphorylation of CREB by MSKs is essential for the production of pro-inflammatory and anti-infammatory cytokines. However, other downstream effectors of MSK1/2 such as nuclear factor-kappa B, histone H3, and high mobility group nucleosome binding domain 1 may also regulate gene expression in immune cells involved in disease pathogenesis. MSKs are master regulators of cell function that integrate signals induced by growth factors, proinflammatory cytokines, and cellular stresses, as well as those induced by LPA.展开更多
The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for ...The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for 60 min followed by reperfusion for 24 h. Eighteen male C57BL/6 mice were randomly divided into three groups: sham-operated group(sham), IRI+saline group(IRI group), IRI+Fenofibrate(FEN) group. Normal saline or Fenofibrate(3 mg/kg) was intravenously injected 60 min before renal ischemia in IRI group and FEN group, respectively. Blood samples and renal tissues were collected at the end of reperfusion. The renal function, histopathologic changes, and the expression levels of pro-inflammatory cytokines [interleukin-8(IL-8), tumor necrosis factor alpha(TNF-α) and IL-6] in serum and renal tissue homogenate were assessed. Moreover, the effects of Fenofibrate on activating phosphoinositide 3 kinase/protein kinase B(PI3K/Akt) signaling and peroxisome proliferator-activated receptor-α(PPAR-α) were also measured in renal IRI. The results showed that plasma levels of blood urea nitrogen and creatinine, histopathologic scores and the expression levels of TNF-α, IL-8 and IL-6 were significantly lower in FEN group than in IRI group. Moreover, Fenofibrate pretreatment could further induce PI3K/Akt signal pathway and PPAR-α activation following renal IRI. These findings indicated PPAR-α activation by Fenofibrate exerts protective effects on renal IRI in mice by suppressing inflammation via PI3K/Akt activation. Thus, Fenofibrate could be a novel therapeutic alternative in renal IRI.展开更多
Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has ...Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.展开更多
The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to al...The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and展开更多
AIM: To investigate the functional significance of insulin-like growth factor binding protein-5 (IGFBP-5) overexpression in pancreatic cancer (PaC).METHODS: The effects of IGFBP-5 on cell growth were assessed by...AIM: To investigate the functional significance of insulin-like growth factor binding protein-5 (IGFBP-5) overexpression in pancreatic cancer (PaC).METHODS: The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses. Changes in cell survival and signal transduction were evaluated after mitogen and phosphatidylinositol activated protein kinase 3-kinase (PI3K) inhibitor treatment.RESULTS: After serum deprivation, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 (ERK1/2) activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION: These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.展开更多
Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in ...Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in teleost.Identification,characterization,classification,and expression profiling of totally 15 mapk genes in black rockfish(Sebastes schlegelii)were conducted.Phylogenetic relationships show that these mapk genes could be divided into extracellular signal-regulated kinase(ERK),c-Jun N-terminal kinase(JNK),and p38 sub-families.In addition,gene structures,syntenic analysis,and selective pressure analysis are performed to confirm their annotations.Results of selective pressure analysis indicate that mapk1,mapk3,mapk7,mapk10,mapk11,and mapk12 underwent significantly-positive selections,while the others genes such as mapk4,mapk6,mapk15,mapk8a,mapk8b,mapk9,mapk13,mapk14a,and mapk14b were under purifying selections.Moreover,results of qRT-PCR indicate that mapk genes in 8 healthy tissues displayed different expression patterns.The expression patterns of several mapk genes including mapk12,mapk13,mapk14a,mapk14b,and mapk15 were significantly changed in mucosal tissues after Edwardsiella piscicida infection.This study demonstrates that mapk genes in black rockfish play vital prevention roles against bacterial infection,which not only helps us understand the structure and function of mapk genes in black rockfish,but also provides a reference to understand the role of mapk genes in teleost immune responses.展开更多
基金supported in part by grants from the Young Scientists Awards Foundation of Shandong Province of China,No.BS2013YY049the China Postdoctoral Science Foundation,No.2012M511036
文摘Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase (p38 MAPK) pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin (30 mg/kg) for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.
基金Supported by the Liver Fibrosis Foundation of Wang BaoEn of China,No.20100033the Science and Technology Foundation of Shaanxi Province of China,No.2010K01-199
文摘AIM To investigate the antioxidant effect of caffeic acid phenethyl ester (CAPE) in hepatic stellate cell-T6 (HSC-T6) cells cultured in vitro and the potential mechanisms. METHODS HSC-T6 cells were cultured in vitro and treated with various concentrations of CAPE for 24, 48 and 72 h, respectively. Cell proliferation was investigated using the MTT assay, and cell ultrastructural alterations were observed by transmission electron microscopy. Flow cytometry was employed to investigate the effects of CAPE on apoptosis and the levels of reactive oxygen species in HSC-T6 cells cultured in vitro. An enzyme immunoassay instrument was used to evaluate antioxidant enzyme expression. The effect on alpha-smooth muscle actin was shown using immunofluorescence. Gene and protein levels of Nrf2, related factors, and mitogen activated protein kinases (MAPKs), in HSC-T6 cells were detected using RT-PCR and Western blot, respectively. RESULTS CAPE inhibited the proliferation and activation of HSC-T6 cells cultured in vitro. CAPE increased the antioxidant levels and the translocation of Nrf2 from the cytoplasm to the nucleus in HSC-T6 cells. Moreover, the phosphorylation of MAPKs in cells decreased in response to CAPE. Interestingly, CAPE-induced oxidative stress in the cells was significantly attenuated by pretreatment with MAPKs inhibitors. CONCLUSION CAPE inhibits cell proliferation and up-regulates the antioxidant levels in HSC-T6 cells partly through the Nrf2-MAPKs signaling pathway.
基金a grant from the Science and Technology Department of Jilin Province,No. 200705172
文摘We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.
基金in part by Natural Sciences Foundation of China (No. 39870239)by the Sasagawa Fellowship,Japan.
文摘Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.
文摘Objective To study the cardioprotective effects of hypoxic preconditioning (HPC) on aged rat ventricular myocytes and the cellular mechanism of protection Methods In the model of hypoxia/reoxygenation (H/R) of isolated ventricular myocytes of aged rat, the effects of HPC on aged rat ventricular myocytes against lethal H/R stimulated ischemia/reperfusion (I/R) injury 24 hours later and the changes of mitogen activated protein kinase (MAPK) system were observed in the present study Results HPC attenuated the lactate dehydrogenase (LDH) release and ATP depletion in myocytes and increased the viability of myocytes It was also found that MAPK and its down stream kinase—S6 kinase were also activated after HPC Conclusion There is delayed cardioprotection in cardiac myocytes of aged rat and the cellular mechanism underlying might involve the activation of MAPK system
基金Supported by the National Natural Science Foundation of China(No.81173179)the Natural Science Foundation of Fujian Province(No.2011J01198)+5 种基金the Fujian Medical Innovation Project(No.2009-CX-19)the Research Foundation of Fujian Health Department(No.Zlcnfm02)the Fujian Provincial Department of Education Category A Projects(No.JA09131)the Fujian Health Department of Traditional Chinese Medicine Research(No.WZY0920)the CHEN Ke-ji Integrative Medicine Development Fund(No.CKJ2008047,CKJ2009004)the Integrative Medicine of Fujian Key Laboratory of Age-related Diseases Funded Projects(No.2008J1004-10)
文摘Objective:To investigate the effect of Dan-gua Fang(丹瓜方) on adenosine 5’-monophosphate(AMP) activated protein kinase(AMPK) α expression in liver and subsequent improvement of glucose and lipid metabolism.Methods:Forty 13-week-old diabetic Goto-Kakizaki(GK) rats were randomly divided into model,Dan-gua Fang,metformin and simvastatin groups(n=10 for each),and fed high-fat diet ad libitum.Ten Wistar rats were used as normal group and fed normal diet.After 24 weeks,liver expression of AMPK α mRNA was assessed by real-time PCR.AMPK α and phospho-AMPK α protein expression in liver was evaluated by Western blot.Liver histomorphology was carried out after hematoxylin-eosin staining,and blood glucose(BG),glycosylated hemoglobin A1c(HbA1c),food intake and body weight recorded.Results:Similar AMPK α mRNA levels were found in the Dan-gua Fang group and normal group,slightly higher than the values obtained for the remaining groups(P〈0.05).AMPK α protein expression in the Dan-gua Fang group animals was similar to other diabetic rats,whereas phospho-AMPK α(Thr-172) protein levels were markedly higher than in the metformin group and simvastatin group(P〈0.05),respectively.However,phosphor-AMPKa/AMPK α ratios were similar in all groups.Dan-gua Fang reduced fasting blood glucose with similar strength to metformin,and was superior in reducing cholesterol,triglycerides,high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin.Dan-gua Fang decreases plasma alanine aminotransferase(ALT) significantly.Conclusion:Dan-gua Fang,while treating phlegm-stasis,could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet,and effectively protect liver histomorphology and function.This may be partly explained by increased AMPK expression in liver.Therefore,Dan-gua Fang might be an ideal drug for comprehensive Intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.
基金ThestudywassupportedbythegrantfromtheNationalNaturalScienceFundationofChina (No 39730 430 )
文摘Obejctives To study mitogen activated protein kinase (MAPKs) activation in fibroblast like synoviocytes (FLS) of rheumatoid arthritis (RA) under the stimulation of IL 1β, and to elucidate the role of protein tyrosine kinase (PTK) in the activation of MAPKs Methods Primary cultures of RA FLS were used Western blot was applied to examine transient changes in protein tyrosine phosphorylation status and MAPKs activation in RA FLS stimulated with IL 1β at various doses, and over different periods Genistein, the specific PTK inhibitor, was used to evaluate the inhibitory role in activation of MAPKs by IL 1β Results IL 1β transiently increased protein tyrosine phosphorylation, and activated the MAPKs cascades (mainly ERK 2, JNK 2 and P 38 ) in RA FLS There was no obvious difference in MAPKs activation among different doses of IL 1β (1?IU/ml,10?IU/ml, 100?IU/ml), but the peak activation of ERK 2, JNK 2 and P 38 took place at 5?min, 15?min and 1?min, respectively, after stimulation with IL 1β The activation of ERK 2 was inhibited by genistein, but the inhibitory role on that of JNK and P 38 was relatively weak Conclusions During signal transduction of IL 1β in RA FLS, tyrosine phosphorylation was increased transiently, the MAPKs cascade was activated in a few minutes, and there was heterogenicity in the activation among three subfamily members PTK had a role in the activation of ERK, but had weak effects on that of JNK and P 38
基金This study was supported by a grant from the National Natural Science Foundation of China (No. 30872719).
文摘Background Acute lung infection due to Pseudomonas aeruginosa (P. Aeruginosa) is a serious problem, especially in patients with structural lung conditions or immune compromised hosts, leading to an overwhelming threat with a high risk of morbidity and mortality. As an outcome of infection, fibrosis can be linked with chronic lung diseases. But some fibrotic manifestations, such as an irreversible decrease of lung function and fibrous bands seen on chest imaging, have been found after an acute infection with P. Aeruginosa. Fibrogenesis/remodeling resulting from acute lung infection by P.aeruginosa is rarely reported. This study was designed to explore the relation between fibrogenesis/remodeling and acute infection by P. Aeruginosa in vitro. We used flagellin protein from P. Aeruginosa, a key initiator of acute P.aeruginosa lung infection, to elucidate mechanisms by which acute lung infection with P. Aeruginosa can cause fibrogenesis/remodeling.Methods We studied the effect of flagellin from P. Aeruginosa (flagellin for short) on the transforming growth factor beta 1 (TGF-β1) and interleukin-8 (IL-8) expression, and the possible involvement of the signaling pathway, tumor necrosis factor receptor-associated factor 6 (TRAF6)/mitogen activated protein kinase (MAPK) pathway. Flagellin was purified from the P. Aeruginosa standard strain, PAO1. Normal bronchial epithelial cells BEAS-2B were challenged with different concentrations of flagellin, and cell viability assessment was performed by cell counting kit-8. BEAS-2B cells were incubated with flagellin with the specific MAPK inhibitors or TRAF6 siRNA. Cell lysates and the cultured supernatant were collected. The level of TGF-β1 and IL-8 were detected by enzyme-linked immunosorbant assay (ELISA). Western blotting was used to detect the protein levels of MAPK signal proteins p38, c-Jun NH2-terminal kinase (JNK) and extracellular regulated kinase (ERK).Results Expression of TGF-β1 in BEAS-2B cells was elevated by flagellin vs. Control groups ((104.3±20.8) vs.(44.6±4.4) pg/ml (P 〈0.01)) and was ablated by either p38 or JNK inhibitors compared with flagellin treatment ((45.1±18.8)vs. (104.3±20.8) pg/ml and (48.1±20.8) vs. (104.3±20.8) pg/ml, respectively (P 〈0.05)). Flagellin also elevated the expression of IL-8 in BEAS-2B cells vs. The control groups ((554.9±57.7) vs. (51.4±2.2.9) pg/ml (P 〈0.01)), and p38 MAPK inhibitors weaken the expression by flagellin ((301.1 ±155.1) vs. (554.9±57.7) pg/ml (P 〈0.05)). Western blotting revealed that all three MAPK proteins, p38, JNK and ERK were activated by flagellin challenge in an early phase, respectively in 15 minutes (P 〈0.01), 30 minutes (P 〈0.01) and 15 minutes (P 〈0.01). TRAF6 siRNA which decreased expression of TRAF6, altered the activation of JNK, p38, and ERK following flagellin treatment, but its influence on the expression of TGF-β1 and IL-8 has no statistical significance.Conclusions Flagellin from P. Aeruginosa PAO1 induces TGF-β1 expression in normal bronchial epithelial cells,BEAS-2B, through the MAPK signal cascade in vitro. It suggests that the fibrogenesis/remodeling process may be initiated from an early stage of acute lung infection due to P. Aeruginosa.
文摘Background Complement receptor type 2 (CR2) is the receptor for C3d and C3dg and for Epstein Barr virus The aim of our study was to explore whether CR2 can independently mediate the activation of mitogen activated protein kinases (MAPKs, including ERK, JNK, and p38MAPK), and to highlight the molecular mechanism of CD 4 + cell deletion in AIDS Methods HOS cells (HOS CR2) and HOS CD4 cells (HOS CD4CR2) stably expressing CR2 were established and then identified by FACS and Western blotting Activation and blocking tests of MAPKs were assessed by Western blot Cell proliferation was determined using Cell Titer 96 Aqueous One Solution Reagent Results FACS results showed that the positive rates of HOS CR2 and HOS CD4CR2 cells were greater than 96%, and Western blot showed that the CR2 expression levels on HOS CR2 and HOS CD4CR2 cells were high Activation and blocking tests of MAPKs (ERK, JNK, and p38MAPK) were carried out in HOS CR2, HOS CD4, and HOS CD4CR2 cells The activation of MAPKs in HOS CR2 cells stimulated with PMA (100 ng/ml) and NHS (10%) was identical The activation of MAPKs increased at 5 minutes, reached a peak at 10 minutes, and decreased to baseline within 30 minutes, all in a time dependent manner; the activation of MAPKs was blocked by anti CR2 McAb, PD98059 (inhibitor of ERK), and Wortmanin (inhibitor of PI 3K), respectively In HOS CD4 cells, MAPKs were activated by HIV gp160 In HOS CD4CR2 cells, MAPK activation was induced by HIV gp160, 10% NHS, and HIV gp160+10%NHS; phosphorylation of p38MAPK was dramatically induced by HIV gp160+NHS, and lasted for 1 hour The cell proliferation results showed that HIV gp160 inhibited the proliferation of HOS CD4 and HOS CD4CR2 cells ( P <0 01) and that NHS enhanced the effect of HIV gp160 ( P <0 01) Conclusions The activation of MAPKs is independently mediated by CR2 and that anti CR2 McAb, PD98059, and Wortmanin block the activation of MAPKs, respectively The results of the signal transduction and cell proliferation assays of HOS CD4CR2 cells show that CR2 plays a role in the pathogenesis of HIV infection, especially in the inhibition of CD 4 + cell proliferation
基金supported by a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada (Grant No. 6793)a grant from the Heart and Stroke Foundation of Canada (Grant No. G-140005874) to KBS. KBS holds the Canada Research Chair in Molecular PhysiologyKKB, CWW, and SNT all held NSERC postgraduate scholarships
文摘Very few selected species of primates are known to be capable of entering torpor. This exciting discovery means that the ability to enter a natural state of dormancy is an ancestral trait among primates and, in phylogenetic terms, is very close to the human lineage. To explore the regulatory mechanisms that underlie primate torpor, we analyzed signal transduction cascades to discover those involved in coordinating tissue responses during torpor. The responses of mitogen-activated protein kinase(MAPK) family members to primate torpor were compared in six organs of control(aroused) versus torpid gray mouse lemurs, Microcebus murinus. The proteins examined include extracellular signal-regulated kinases(ERKs), c-jun NH2-terminal kinases(JNKs), MAPK kinase(MEK), and p38, in addition to stress-related proteins p53 and heat shock protein 27(HSP27). The activation of specific MAPK signal transduction pathways may provide a mechanism to regulate the expression of torpor-responsive genes or the regulation of selected downstream cellular processes. In response to torpor, each MAPK subfamily responded differently during torpor and each showed organ-specific patterns of response. For example, skeletal muscle displayed elevated relative phosphorylation of ERK1/2 during torpor. Interestingly, adipose tissues showed the highest degree of MAPK activation. Brown adipose tissue displayed an activation of ERK1/2 and p38, whereas white adipose tissue showed activation of ERK1/2, p38, MEK, and JNK during torpor. Importantly, both adipose tissues possess specialized functions that are critical for torpor, with brown adipose required for non-shivering thermogenesis and white adipose utilized as the primary source of lipid fuel for torpor. Overall, these data indicate crucial roles of MAPKs in the regulation of primate organs during torpor.
文摘Ninety male Wistar rats were selected under the "Guide for the Care and Use of Laboratory Animals" for skin-muscle wound models. Three groups of animals were examined respectively for inoculation of inhibitor of p38 MAPK (mitogen activated protein kinase) SB 203580 and JNK inhibitor SP 600125, and a control. Light microscopy, immunohistochemistry, and tensometry revealed that the inhibition of p38 or JNK cascades have modified the formation of the connective tissue scar. The degree of connective tissue growth in the area of surgical wound had been significantly reduced by the end of observation (30 d) as the SB 203580 was applied (% volume of collagen 43.60 (41.05 - 60.15) vs. 73.54 (66.87 - 78.01) in control, p = 0.002). Conversely, when we have applied the JNK blocker, the density of collagen in scar tissue increased (78.14 (72.77 - 81.14), p = 0.022 vs. control). SB203580 inhibits the expression of p38, c-Jun and c-Fos. When we have used the JNK blocker, the expression of c-Fos and c-Jun decreased, but the expression of p38 increased. This determines the high functional activity of fibroblasts after using SP 600125. Obtained results show the importance of studying regulators of cell differentiation as potential drugs, which significantly affect the outcome of the pathological processes.
文摘Background The plasma concentration of very low density lipoprotein (VLDL) is negatively correlated to renal function in glomerular diseases. Effects of VLDL on renal function have been partially attributed to the proliferation of mesangial cells. This study examined the potential role of the p42/44 mitogen activated protein kinase (MAPK) in mesangial cell proliferation induced by VLDL. Methods Mesangial cells were treated with VLDL at different concentrations or for different time. The cell cycle of the mesangial cells was analyzed by Xl-r assay and flow-cytometry; MAPK activity was also assayed. In some experiments, cells were treated with VLDL together with or without 0.1 pmol/L PD 98059. Results Ten to 500 μg/ml VLDL stimulated the proliferation of mesangial cells cultured in vitro in a concentration-dependent manner. The effect was associated with an increase in p42/44 MAPK activity. Increased proliferation of mesangial cells by VLDL was significantly attenuated by PD98059, a specific p42/44 MAPK inhibitor. Conclusion These results indicate that the p42/44 MAPK pathway is an important regulator of mesangial cell proliferation and of renal functions.
基金Supported by A research grant from the Arthritis Society of CanadaNo.RG10/011(to Bourgoin SG)
文摘Lysophosphatidic acid (LPA) is a pleiotropic lipid med-iator that promotes motility, survival, and the synthesis of chemokines/cytokines in human fbroblast-like syno-viocytes (FLS) from patients with rheumatoid arthritis. LPA activates several proteins within the mitogen acti-vated protein (MAP) kinase signaling network, including extracellular signal-regulated kinases (ERK) 1/2 and p38 MAP kinase (MAPK). Upon docking to mitogen and stress-activated kinases (MSKs), ERK1/2 and p38 MAPK phosphorylate serine and threonine residues within its C-terminal domain and cause autophosphorylation of MSKs. Activated MSKs can then directly phosphorylate cAMP response element-binding protein (CREB) at Ser133 in FLS. Phosphorylation of CREB by MSKs is essential for the production of pro-inflammatory and anti-infammatory cytokines. However, other downstream effectors of MSK1/2 such as nuclear factor-kappa B, histone H3, and high mobility group nucleosome binding domain 1 may also regulate gene expression in immune cells involved in disease pathogenesis. MSKs are master regulators of cell function that integrate signals induced by growth factors, proinflammatory cytokines, and cellular stresses, as well as those induced by LPA.
基金supported by the National Natural Science Foundation of China(No.81070557)
文摘The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for 60 min followed by reperfusion for 24 h. Eighteen male C57BL/6 mice were randomly divided into three groups: sham-operated group(sham), IRI+saline group(IRI group), IRI+Fenofibrate(FEN) group. Normal saline or Fenofibrate(3 mg/kg) was intravenously injected 60 min before renal ischemia in IRI group and FEN group, respectively. Blood samples and renal tissues were collected at the end of reperfusion. The renal function, histopathologic changes, and the expression levels of pro-inflammatory cytokines [interleukin-8(IL-8), tumor necrosis factor alpha(TNF-α) and IL-6] in serum and renal tissue homogenate were assessed. Moreover, the effects of Fenofibrate on activating phosphoinositide 3 kinase/protein kinase B(PI3K/Akt) signaling and peroxisome proliferator-activated receptor-α(PPAR-α) were also measured in renal IRI. The results showed that plasma levels of blood urea nitrogen and creatinine, histopathologic scores and the expression levels of TNF-α, IL-8 and IL-6 were significantly lower in FEN group than in IRI group. Moreover, Fenofibrate pretreatment could further induce PI3K/Akt signal pathway and PPAR-α activation following renal IRI. These findings indicated PPAR-α activation by Fenofibrate exerts protective effects on renal IRI in mice by suppressing inflammation via PI3K/Akt activation. Thus, Fenofibrate could be a novel therapeutic alternative in renal IRI.
文摘Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.
文摘The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and
基金Supported by A grant from the Arkansas Master Tobacco Settlement and Arkansas Biosciences Institute
文摘AIM: To investigate the functional significance of insulin-like growth factor binding protein-5 (IGFBP-5) overexpression in pancreatic cancer (PaC).METHODS: The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses. Changes in cell survival and signal transduction were evaluated after mitogen and phosphatidylinositol activated protein kinase 3-kinase (PI3K) inhibitor treatment.RESULTS: After serum deprivation, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 (ERK1/2) activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION: These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.
基金Supported by the National Key R&D Program of China(No.2018YFD0900101)the Young Experts of Taishan Scholars(No.tsqn201909130)+2 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities in Shandong Province(No.2019KJF003)the“First Class Fishery Discipline”Program in Shandong Provincethe Shandong Technical System of Fish Industry(No.SDAIT-12-03)。
文摘Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in teleost.Identification,characterization,classification,and expression profiling of totally 15 mapk genes in black rockfish(Sebastes schlegelii)were conducted.Phylogenetic relationships show that these mapk genes could be divided into extracellular signal-regulated kinase(ERK),c-Jun N-terminal kinase(JNK),and p38 sub-families.In addition,gene structures,syntenic analysis,and selective pressure analysis are performed to confirm their annotations.Results of selective pressure analysis indicate that mapk1,mapk3,mapk7,mapk10,mapk11,and mapk12 underwent significantly-positive selections,while the others genes such as mapk4,mapk6,mapk15,mapk8a,mapk8b,mapk9,mapk13,mapk14a,and mapk14b were under purifying selections.Moreover,results of qRT-PCR indicate that mapk genes in 8 healthy tissues displayed different expression patterns.The expression patterns of several mapk genes including mapk12,mapk13,mapk14a,mapk14b,and mapk15 were significantly changed in mucosal tissues after Edwardsiella piscicida infection.This study demonstrates that mapk genes in black rockfish play vital prevention roles against bacterial infection,which not only helps us understand the structure and function of mapk genes in black rockfish,but also provides a reference to understand the role of mapk genes in teleost immune responses.