Objective To observe the effects of extracellular-signal regulated kinase (ERK) 1/2 inhibitor U0126 on hepatoma carcinoma cell proliferation and apoptosis. Methods Hepatoma SMMC-7721 cell strain was divided into blank control group and different concentrations of U0126 groups. The proliferation inhibition was measured by MTT assay. FCM was used to analyze the cell cycle distribution and apoptosis. Results U0126 obviously inhibited cell proliferation, induced cell apoptosis and G0/G1 phase cell cycle arrest. There were significant differences between control group and different concentrations of U0126 groups on cell proliferation and apoptosis （P＜0.05， P＜0.01）. Conclusion Blocking ERK1/2 pathway may be an important treatment strategy for liver cancer.
Objective To observe the protein expression of c-Jun amino-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in normal skin and keloid and to explore their influences on the formation of kloid. Methods Keloid tissues and normal skin tissues were collected from 16 keloid resection patients (experimental group) and 10 voluntary plastic surgery patients (control group). In the experimental group, the keloid formation time ranged from 8 months to 10 years; the keloid tissues were collected from the chest in 6 cases, the ear lobe in 4 cases, the perineum in 2 cases, the shoulder in 3 cases, and the abdomen in 1 case; and all keloid tissues were confirmed by pathological examination. In the control group, normal skin tissues were collected from the abdomen in 4 cases, the thighs in 3 cases, the shoulder in 2 cases, and the back in 1 case. Two-step l ine of Envision immunohistochemical staining was performed to observe the expressions of nonphosphorylated and phosphorylated JNK and ERK; Image Pro Plus 4.5 image analysis system was used to measure the integrated absorbance (IA) and to observe the positive staining strength. Results The immunohistochemical staining showed that no obvious expressions of phosphorylated and non-phosphorylated ERK, JNK were observed in the fibroblasts of the control group, and the expressions of phosphorylated JNK and ERK proteins were significantly higher in the experimental group than in the control group (P lt; 0.05). There was no significant difference in the expressions of non-phosphorylated JNK and ERK proteins between 2 groups (P gt; 0.05). Conclusion Activation of ERK and JNK pathways might be involved in formation of keloid.
Objective To evaluate the mechanisms of p42/p44 kinase phosphorylation in cell models and to investigate the effect of simvastatin on the prevention and treatment of aseptic loosening of prosthesis by observing the influence of simvastatin on the levels of tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) of human peri pheral blood mononuclear cell (PBMC) challenged with titanium particles. Methods PBMC from 45 mL peripheral blood of healthy adult voluntary donators, were separated and cultured, and divided into 5 groups according to different culturemedium: group A, PBMC and titanium particles; group B, PBMC and titanium particles with 1 × 10-5 mol/L simvastatin; group C, PBMC and titanium particles with 1 × 10-6 mol/L simvastatin; group D, PBMC and titanium particles with 1 × 10-7 mol/L simvastatin; and group E, PBMC and titanium particles with the extracellular signal-regulated kinase (ERK1/2) inhibitor U0126. The contents of TNF-α and MCP-1 were tested by ELISA after 24 hours of culture. PBMC were pretreated with different medium grouping as groups A, B, C, D, and E for 60 minutes, and were challenged with titanium particles for 30 minutes and 60 minutes, then the level of ERK1/2 expression was tested by Western blot. Results In groups A, B, C, D, and E, the absorbance (A) values of TNF-α were 1.115 5 ± 0.243 6, 0.693 6 ± 0.354 3, 0.695 7 ± 0.387 3, 0.716 4 ± 0.478 9, and 0.263 5 ± 0.101 6, respectively; and the A values of MCP-1 were 1.421 0 ± 0.105 3, 0.915 1 ± 0.411 3, 1.003 5 ± 0.464 2, 1.102 0 ± 0.353 9, and 0.271 3 ± 0.145 1, respectively. The levels of TNF-α and MCP-1 in group A were significantly higher than others, showing significant differences (P lt; 0.05). There were significant differences between group E and groups B, C, and D (P lt; 0.05), between group B and groups C, D (P lt; 0.05); no significant difference between group C and group D (P gt; 0.05). Western blot results showed the expression of ERK1/2 in all groups at 30 minutes and 60 minutes of culture. The levels of ERK1/2 expression were 1.612 1 ± 0.068 2, 1.078 1 ± 0.072 8, 1.268 7 ± 0.223 1, 1.439 7 ± 0.180 1, and 0.732 0 ± 0.110 4 in groups A, B, C, D, and E, respectively; showing significant differences between groups (P lt; 0.05). Conclusion ERK1/2 is a phosphorylated protein after stimulated by wear particles; it is also one of the most important cell signal ing activation of macrophage. Simvastatin can inhibit the expression of bone absorptive factors induced by wear particles and may be used in the prevention and treatment of aseptic loosening of prosthesis.
Objective The biological effects of fibroblast growth factor (FGF) may be different under different intensities and durations. To investigate the impact of sustained increasing FGF signal upon the development of epiphyseal plate. Methods Epiphyseal plates cultured in vitro were obtained from embryonic C57BL/6J mice, and were divided into control group (0.1% DMSO), basic FGF (bFGF) group (100 μg/L bFGF and 0.1% DMSO), and PD98059 group (100 μg/L bFGF and 50 μmol/L PD98059 with 0.1% DMSO). The total length (TL) and ossified tissue length (OSL) of the cultured bones weremeasured with Calcein staining 6 days after culture. The expressions of Indian hedgehog (Ihh), collagen type II (Col II), and Col X genes were detected by real-time fluorescent quantative PCR 7 days after culture. Results The embryonic bones cultured in vitro continued growth. At 6 days after culture, there was no significant difference in increased percentage of TL between bFGF group and control group (P gt; 0.05), the increased percentage of OSL in bFGF group was significantly less than that in control group (P lt; 0.05). There was no significant difference in the increased percentage of TL and OSL between PD98059 group and control group (P gt; 0.05), but they were significantly higher than those of bFGF group (P lt; 0.05). At 7 days after culture, the gene expressions of Ihh, Col II, and Col X in bFGF group significantly decreased when compared with those in control group (P lt; 0.05). There was no significant difference in the gene expressions of Col II and Col X between PD98059 group and control group (P gt; 0.05), but the gene expressions were significantly higher than those of bFGF group (P lt; 0.05); the expression of Ihh in PD98059 group was significantly higher than that in control group and bFGF group (P lt; 0.05). Conclusion Sustained increasing FGF signal may affect the Col II and Col X expressions by down-regulating Ihh, which may lead to the development retardation of epiphyseal plate cultured in vitro. The external signal regulated kinase pathway may play an important role in the process.
Objective To study the function of platelet-derived growth factor (PDGF) in inducing phosphorylation extracellular signalregulated kinase 1/2 (pERK1/2) localization in osteoblasts. Methods Primary osteoblasts were isolated and cultured from cranial bone of 10 mice atthe age of 3 days, weighting 6-9 g without limitation in male and female.The sixth passage osteoblasts were incubated in 1% serum for 12 hours and divided into 2 groups: treated with DMSO(control group) or with PP2(experimentalgroup) for 30 minutes. Each group was further divided into 2 subgroups according to with or without PDGF (20ng/ml) stimulation for 10 minutes. pERK1/2 localization was analysized by immunofluorescence staining in osteoblasts pretreated with or without Src inhibitor PP2. The sixth passage osteoblasts were divided into 2 groups treated with DMSO (control group) or with PP2 (experimental group) for 30 minutes. Each group was further divided into two subgroupsaccording to with or without PDGF (20 ng/ml) stimulation for 10 mintues. The ability of osteoblast migration was determined by wound healing assay. The sixth passage osteoblasts were divided into 2 groups treated with DMSO (control group) or 10 μmol/L PP2 (experimental group) for 30 mintues. Each group was further divided into 2 subgroups according to with or without PDGF (20 ng/ml) stimulation.The pERK1/2 was determined by Western blot in osteoblastic cytoskeleton inducedby PDGF. Results Immunofluorescence staining showed pERK1/2 localization in osteoblastic nuclears and focal adhesions after PDGF stimulation. PP2 significantly inhibited ERK1/2 localization in focal adhesions, but not in nuclears. The wound healing assay results showed that PP2 significantly inhibited osteoblast migration induced by PDGF. The result of Western blot demonstrated that pERK1/2 in osteoblastic cytoskeleton was significantly inhibitedSrc activation is required for pERK1/2 translocalization to focal adhesions and osteoblasts migration.
Objective To investigate the possible signaling mechanisms by which recombinant human plateletderived growth factor (rhPDGF) accelerated healingof cutaneous wound in diabetic rats. Methods Four full-thickness skin woundswere incised in the back of 26 male Wistar diabetic rats. The wounded rats were divided into 3 groups (7 or 8 rats each group). One group without treatmentwas used as a control, and the other 2 groups were treated with rhPDGF at a dose of 7.0 μg/cm2 wound or vehicle (DMSO/09% NaCl, vol/vol 1∶1) from 1 to14 days. The wound healing was evaluated by the measurements of the wound volume and area. Immunofluorescent and immunohistochemical staining were used to examine the phosphorylation of extracellular signalregulated kinase 1/2 (ERK1/2) andthe expression of proliferative cell nuclear antigen (PCNA), respectively. Results Granulation tissue appeared in the bed of wound after injury. The number of blood capillary buds and fibroblasts was greater in the rhPDGF-treated group than that in the other 2 groups. A lot of inflammatory cells infiltration and collagen deposition were observed in the wound. The wound-volume in the rhPDGF-treated group was smaller than that in control group (Plt;0.05). The reepithelialization rate in rhPDGF-treated group was higher than that inthe other 2 groups at 7 days after injury (Plt;0.05). The expression of PCNA in reparative cells was higher in rhPDGF-treated group than in control group or vehicle-treated group at 3,7 days after injury(Plt;0.05). The phosphorylation of ERK1/2 was ber in rhPDGF-treated group than that in control group or vehicle group at 7 and 14 days after injury(Plt;0.05). Conclusion These results suggest that rhPDGF accelerates wound healing and improves healing quality by increasingthe phosphorylation of ERK1/2.
Objective To observe the effect of angiotensin Ⅱ (Ang Ⅱ) or/and transforming growth factor β(TGF-β) on human skin fibroblast proliferation, and to explore the possible signaling mechanism involved in their actions. Methods Cultured human skin fibroblasts were treated with different concentrations of Ang Ⅱ (1×10-10 , 1×10-9，1×10-8 and 1×10-7 mol/L) , TGF-β(0.1, 1.0 and 10.0 ng/ml), and 1×10 -10 mol/L Ang Ⅱ＋0.1 ng/ml TGF-β, respectively. The cell proliferation was determined by3Hthymidine (3H-TdR) incorporation. The phosphorylation of extracellular signalregulated kinases (ERK) was detected by Western blot. Results Ang Ⅱ at 1×10-9，1×10-8，1× 10-7 mol/L or TGF-β at 1.0, 10.0 ng/ml increased 3H-TdR incorporation into cultured skin fibroblasts dose-dependently. Ang Ⅱ and TGF-β at lower doses (1×10-10 mol/L and 0.1 ng/ml, respectively) did not affect 3H-TdR incorporation into fibroblasts (Pgt;0.05), whereas co-administration of both Ang Ⅱ and TGF-β at these doses significantly increased 3H-TdR incorporation intofibroblasts(Plt;0.05). Ang Ⅱ at 1×10-7 mol/L or TGF-β at 10.0 ng/ml significantly increased ERK phosphorylation of fibroblasts after stimulation (Plt;0.01). Smaller doses of Ang Ⅱ (1×10-10 mol/L) or TGF-β (0.1 ng/ml) did not influence ERKphosphorylation of fibroblasts, whereas co-administration of Ang II and TGF-β at these doses significantly enhanced ERK phosphorylation (Plt;0.05). Total protein levels of ERK did not differ at different doses. Conclusion These results indicate that Ang Ⅱ and TGF-β synergistically increase skin fibroblast proliferation, which is at least partly via enhancement of ERK activity.
【摘要】 目的 探讨坎地沙坦干预后海仁藻酸（kainic acid，KA）致痫大鼠肾脏细胞外信号调节激酶（ERK1/2）的表达及其变化的机制。 方法 105只雄性Wistar大鼠随机分为3组:A1-5对照组、B1-5 致痫组、C1-5坎地沙坦组，每组各35只，1-5分别表示癫痫后0、2、6、12及24 h。采用立体定位仪下杏仁核内注射KA方法制备大鼠癫痫模型，于致痫后不同时程，进行灌流固定、肾脏组织的石蜡包埋、切片及免疫，组织化学染色，检测不同时程肾脏ERK1/2表达的灰度值。 结果 与对照组相比，致痫组及坎地沙坦组肾组织于致痫后2 h ERK1/2表达均开始增加（致痫后2 h ERK1/2，致癫组：20 229.18±2 067.27，坎地沙坦组：16 878.19±2 693.97，对照组:8 054.24±975.90， Plt;0.01），致痫后6 h两组大鼠肾组织ERK1/2的表达均达到高峰（致痫后6 h ERK1/2，致痫组:39 217.34±4 443.33，坎地沙坦组：31 924.85±4 383.80，对照组：8 575.24±1 040.82， Plt;0.01），随后逐渐下降，致痫后24 h两组大鼠肾组织ERK1/2表达均回到0 h水平（Pgt;0.05），对致痫组及坎地沙坦干预两组大鼠肾组织ERK1/2蛋白表达进行组间比较结果显示，坎地沙坦组2 h（致痫组：20 229.18±2 067.27，坎地沙坦组：16 878.19±2 693.97，Plt;0.01）、6 h（致痫组：39 217.34±4 443.33，坎地沙坦组：31 924.85±4 383.80，Plt;0.01）、12 h（致痫组：16 610.11±2 953.03，坎地沙坦组：13 393.16±2 269.42， Plt;0.05）ERK1/2表达降低。 结论 ERK1/2在KA致痫大鼠肾组织中表现为短时程表达增加，坎地沙坦可使肾组织ERK1/2表达降低。【Abstract】 Objective To study the effect of candesartan on extracellular signal-regulated kinase (ERK) 1/2 protein expression of renal cells in epilepsy rats induced by kainic acid (KA) and its mechanism. Methods A total of 105 male Wistar rats were randomly divided into three groups: control group (A1-5, n=35), epilepsy group (B1-5, n=35), and candesartan group (C1-5, n=35). The sign 1-5 meant respectively 0, 2, 6, 12, and 24 hours after epilepsy. Epilepsy rat models were made by injecting KA into amygdala under three-dimensional positioning devices. Lavage fixation, paraffin embedding of the renal tissue, and immunohistological test were carried out at different time points after epilepsy was induced, and ERK1/2 protein expression level was tested. Results Compared with the control group, the protein expression of ERK1/2 increased significantly 2 hours after epilepsy in groups B and C (ERK1/2 level 2 hours after epilepsy, group B: 20 229.18±2 067.27, group C: 16 878.19±2 693.97 vs. group A: 8 054.24±975.90, P＜0.01), and both attained its peak 6 hours after epilepsy (ERK1/2 level 6 hours after epilepsy, group B: 39 217.34±4 443.33, group C: 31 924.85±4 383.80 vs. group A: 8 575.24±1 040.82, P＜0.01), and then decreased gradually to the level immediately after epilepsy 24 hours later. There were significant differences in the level of ERK1/2 protein expression between group B and C 2, 6, and 12 hours after epilepsy was induced (2 hours, group B: 20 229.18±2 067.27 vs. group C: 16 878.19±2 693.97, P＜0.01; 6 hours, group B: 39 217.34±4 443.33 vs. group C: 31 924.85±4 383.80, P＜0.01; 12 hours, group B: 16 610.11±2 953.03 vs. group C: 13 393.16±2 269.42, P＜0.05). Conclusions The Extracellular signal-regulated kinase1/2 protein expression of renal tissue in epilepsy rats induced by KA increases shortly after epilepsy. Candesartan can decrease the protein expression of ERK1/2 in the renal tissue of epilepsy rats.