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[ ABSTRACT] AIM:To explore the effect of sterol regulatory element-binding protein 2 ( SREBP-2) on tunicamy-cin-induced endoplasmic reticulum stress ( ERS) in chondrocytes.METHODS:After isolation of human normal chondro-cytes and osteoarthritis ( OA) chondrocytes, the normal cells were cultured and treated with tunicamycin and SREBP-2 siR-NA.After 24 h treatment, fluorescent quantitative RT-PCR ( RT-qPCR) was applied to quantify microRNA-185 ( miR-185) levels.The cell apoptotic rate was determined by flow cytometry.The expression of SREBP-2 and ERS-related pro-teins, C/EBP homologous protein (CHOP), phosphorylated eukaryotic initiation factor-2α(p-eIF2α) and activating tran-scription factor 4 (ATF4), and the expression of apoptosis-related proteins, Bcl-2, Bax and caspase-3, were determined by Western blot.The caspase-3 activity kit was used to determine the caspase-3 activity.RESULTS: Compared with hu-man normal chondrocytes, both SREBP-2 up-regulation and miR-185 down-regulation were observed in OA chondrocytes (P<0.05).SREBP-2 siRNA transfection enhanced tunicamycin-inhibited miR-185 level (P<0.05).miR-185 overex-pression reduced tunicamycin-induced SREBP-2 expression ( P <0.05 ) .OA control group and tunicamycin treatment group consistently resulted in ERS and cell apoptosis with concomitant enhancement of CHOP, p-eIF2αand ATF4 proteins, increases in Bax and caspase-3 proteins, and reduction of Bcl-2 (P<0.05).However, SREBP-2 silencing significantly re-versed these effects ( P<0.05) .The apoptotic rates were consistent with the expression tendency of apoptosis-related pro-teins (P<0.05).SREBP-2 siRNA transfection markedly down-regulated tunicamycin-induced caspase-3 activity, which was notably blocked by miR-185 inhibition (P<0.05).CONCLUSION:SREBP-2 silencing may inhibit tunicamycin-in-duced ERS and cell apoptosis via up-regulating miR-185 expression.
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Objective To investigate the extent of cross-education between the pronation and supination muscles of the right and left forearms after unilateral isometric training.Methods Twenty healthy young girls were randomized into a training group and a control group using a random number table.The training group underwent isometric training of their right forearms for six weeks,while the control group continued ordinary life without exercises.Pronation peak torque (PPT) and supination peak torque (SPT) were assessed before and after the training for both groups.Results The differences in PPT or SPT between the training group and the control group were not significant before the training program.When the training had been completed,however,the average PPT and SPT on right side of those trained of course had increased significantly compared to before training or to the control group.More significantly,the average PPT and SPT on the left side in the training group were also significantly better than before training or in the control group after training.Conclusion Unilateral isometric training of the forearm pronation and supination muscles for six weeks can significantly increase muscle strength bilaterally,indicating good cross-education.
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Objective To investigate the effects on one hand of training the other with isometric wrist extension and flexion training and its underlying mechanism.Methods Twenty healthy young girls were recruited and randomized into a training group and a control group with 10 subjects in each,using a random number table.The subjects in the training group were accepted isometric training of the wrist extensors and flexors on the right side once every other day,4 days a week for 6 weeks according to a pre-programmed protocol,while those in the control group had no intervention.Peak torque and surface electromyography (sEMG) were recorded and assessed before and after 6 weeks of training.Results In the training group,the average peak torque of right wrist flexion and extension were both significantly higher than before training (within-group comparison) and higher than in the control group (between-group comparison) after 6 weeks of training.The average peak torques of the left wrist in the training group in flexion and extension were (12.9±2.0) Nm and (6.4 ± 1.3) Nm after training,both significantly higher than before the training and stronger than the control group.In the sEMG traces during wrist extension,after training the ascend velocity of the right extensor carpi ulnaris and the integrated area of the left extensor carpi ulnaris in the training group were significantly smaller than before training and in the control group.Conclusion Unilateral isometric resistance training of the wrist muscles can transfer to the contralateral side,probably by altering muscle recruitment.
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AIM:To investigate the effect of microRNA-16 ( miR-16) on the proliferation, invasion and cyto-kine secretion of rheumatoid arthritis ( RA) synovial fibroblasts ( RASFs) from the RA patients.METHODS: miR-16 mimic and miR-16 inhibitor were synthesized, and then Transfected into RASFs isolated from RA patients with lipo-fectamine.MTT assay, Transwell chamber and flow cytometry were used to determine the effect of miR-16 on proliferation, invasion and apoptosis of RASFs.The expression of matrix metalloproteinase 3/13 ( MMP3/13) and interleukin 1β( IL-1β) was measured by RT-PCR and Western blotting.RESULTS: The proliferation and invasion of RASFs were signifi-cantly inhibited by miR-16 mimic.The result of flow cytometry demonstrated that miR-16 had no effect on apoptosis of RASFs.Furthermore, miR-16 down-regulated the expression of MMP3/13 and IL-1β.CONCLUSION:miR-16 plays an important role in the development of RA and may inhibit the proliferation and invasion of RASFs through down-regulating the expression of MMP3/13 and IL-1β.
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Objective To study the expression of Gli1 protein and vascular endothelial growth factor (VEGF)-C in papillary thyroid carcinoma and their relationship with cervical lymph node metastasis.Methods The expression of Gli1 protein and VEGF-C were investigated by immunohistochemical EnVision method in 67 cases of papillary thyroid carcinoma and 32 cases of nodular goiter pathological specimen tissues.Nascent microvascular and micro-lymphatic of all pathological speimen tissues were examined by immunohistochemical monoclonal antibody CD34 and D2-40 staining assay respectively,and the microvascular density (MVD) and micro-lymphatic vessel density (MLVD) were calculated.The relationship between the positive expression of Gli1 protein and MVD,between the positive expression of VEGF-C and MLVD,and their relationship with cervical lymph node metastasis were analyzed.Results The positive rates of Gli1 protein,VEGF-C and MVD,MLVD were significantly higher in papillary thyroid carcinoma than those in nodular goiter [67.16％(45/67) vs.43.75％(14/32),70.15％(47/67) vs.31.25％(10/32),23.14 ± 2.06 vs.2.14 ± 0.31,13.36 ± 1.32 vs.3.53 ± 0.65,P ＜ 0.05].The positive expression of Gli1 protein was related to the patient' s age and the tumor size (P ＜ 0.05),while the positive expression of VEGF-C was not related to the patient' s age and the tumor size (P ＞ 0.05).The positive expression of Gli1 protein and VEGFC were significantly higher in TNM stage Ⅲ-Ⅳ of papillary thyroid carcinoma than those in TNM stage Ⅰ-Ⅱ (P ＜ 0.01) and also was significantly higher with cervical lymph node metastasis than without cervical lymph node metastasis (P ＜ 0.01).MVD and MLVD were significantly higher with cervical lymph node metastasis than without cervical lymph node metastasis (P ＜ 0.05).The positive expression of Gli1 protein was positively correlated with MVD (r =0.784,P＜ 0.01),the positive expression of VEGF-C was positively correlated with MLVD (r =0.529,P ＜ 0.01),the positive expression of Gli 1 protein was positively correlated with the positive expression of VEGF-C (r =0.586,P ＜0.01).Conclusions Gli1 protein which may participate in the formation of nascent microvascular is abnormally activated by the Hedgehog signaling pathway to express,VEGF-C which may be participate in the formation of nascent micro-lymphatic is mediated and started by the MAPK signaling pathways to express.Expressions of Gli1 protein is positively correlated with expressions of VEGF-C,therefore the Hedgehog signaling pathway may be associated with the MAPK signal pathway.Suppressing nascent microvascular and micro-lymphatic may become new target to blockingup papillary thyroid carcinoma cervical lymph node metastasis.
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@#ObjectiveTo compare the coordination characteristic of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) between patients with knee osteoarthritis and healthy subjects. Methods34 patients with knee osteoarthritis and 34 controls with normal knee were tested in isometric knee extension at knee joint angles of 10°, 60°, 100° flexion and isokinetic knee extension at velocities of 60°/s and 180°/s. Surface electromyogram (EMG) was recorded in the VM, RF and VL. The activation sequence of muscles and VM/VL EMG ratio were analyzed. ResultsThe VM started significantly later than the VL in isokinetic contraction at 180°/s in patients compared with the controls (P<0.05), and the VM/VL EMG ratio decreased in isometric contraction with knee extension at 10° (P<0.05). ConclusionThe coordination of the vastus medialis, rectus femoris and vastus lateralis decreases in the knee osteoarthritis patients.
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@#Objective To investigate the activation characteristics (contraction velocity, force and anti-fatigue) of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) by using surface electromyogram (sEMG) during isometric and isokinetic quadriceps femoris force tests in knee osteoarthritis. Methods The participants included an observation group (n=34) and a control group (n=34).The age, height, body weight, gender, dominant side and Q angle were matched between the two groups. The participants' quadriceps femoris force and sEMG of VM, RF and VL were tested in isometric knee extension at knee joint angles of 10°, 60°, 100° and isokinetic knee extension at velocities of 60°/s and 180°/s. Comparisons were made for recruitment rate, average amplitude, peak torque/bodyweight ratio, index of fatigue by independent-group t-test, with the alpha level set at 0.05 for significant differences between groups.Results ①Recruitment rate of VM in isometric contraction at 60° and isokinetic contraction at 60°/s and 180°/s, RF in isometric contraction at 60° and isokinetic contraction at 60°/s and VL in isometric contraction at 10°and 100° and isokinetic contraction at 60°/s were all significantly slower in the observation group than that in the control group(P<0.05). ②The average amplitudes of VM, RF in isokinetic contraction at 60°/s and 180°/s and RF, VL in isometric contraction at 10° were significantly higher in the observation group than that in the control group(P<0.05). ③Peak torque/bodyweight ratio of quadriceps was significantly lower in the observation group than that in the control group in isometric contraction at 10°, 60°, 100° and isokinetic contraction at 60°/s and 180°/s(P<0.05). ④In isokinetic contraction at 180°/s the index of fatigue was significantly higher in the observation group than that in the control group (P<0.05).Conclusion A significant decreasing contraction velocity and force, increasing anti-fatigue of the vastus medialis, rectus femoris and vastus lateralis were found in knee osteoarthritis patients when compared with healthy subjects.