ObjectiveTo explore the effect of JNK-c-Jun signal pathwayon connexin 43 (Cx43) expression and its role in renal tubular epithelial-myofibroblast transition (TEMT) induced by TGF-β1.Methods Normal rat kidney tubular epithelial cells(NRK-52E) were cultured in Dulbecco's modified eagle medium(DMEM) with 10％ fetal bovine serum,then were randomly divided into 3 groups: control group,TGF-β1 group (treated with TGF-β1 10 μg/L),and TGF-β1+SP600125 (selective JNK inhibitor,50 μmol/L) group. The protein expressions of JNK,c-Jun,α-SMA,Cx43 and E-cadherin were assayed by immunocytochemistry and Western blotting.The Cx43mRNA was assayed by RT-PCR.Gap junction intercellular communication(CJIC) was measured by fluorescence recovery after photobleaching assay(FRAP).Results TGF-β1increased the expressions of JNK,c-Jun and α-SMA(P＜0.05),reduced the expressions of Cx43 and E-cadherin (P＜0.05),and inhibited GJIC of NRK-52E(P ＜0.05).SP600125 could alleviate the above expressions changes and enhanced GJIC induced by TGF-β1.Conclusion JNK-c-Jun signal pathway induces TEMT ofNRK-52E treated with TGF-β1 viadown-regulation of connexin 43expression and inhibition of GJIC.

ObjectiveTo investigate the role of Nav1.7 in dorsal root ganglia (DRG) in a rat model of diabetic neuropathic pain (DNP).MethodsThirty-two female Wistar rats aged 3 months weighing 180-220 g were randomly divided into 4 groups ( n ＝ 8 each):control group ( group C),sham operation group ( group S),DNP group and ProTx- Ⅱ (a selective Nav1.7 blocker) group (group E).Diabetes mellitus was induced by intraperitoneal streptozocin 65 mg/kg.Blood glucose level and mechanical paw withdrawal threshold (MWT)to von Froy filamentstimulation were measured 2 weeks later.DNP was confirmed by blood glucose level ≥ 16.0 mmol/L and MWT decreased by more than 50％ of the baseline value.Intrathecal catheter was implanted at L5,6 interspace on day 10 after successful induction of DNP.On day 4 after placement of the intrathecal catheter,ProTx- Ⅱ 10 μg/kg was injected intrathecally in group E,while the equal volume of normal saline was given in groups DNP and S.MWT and never conduction velocity (NCV) were measured 1 h after intrathecal injection.The rats were then sacrificed and DRGs of the lumbar segment (L4-6) were removed for determination of Nav1.7 protein expression (by immuno-histochemistry and Western blot) and Nav1.7 mRNA expression (by RT-PCR).ResultsThe MWT and NCV were significantly lower and the Nav1.7 mRNA and protein expression was significantly higher in groups DNP and E than in group C.ProTx- Ⅱ significantly attenuated the diabetes-induced changes in MWT,but had no effect on NCV and Nav1.7 mRNA and protein expression.ConclusionNav1.7 in DRG is involved in the maintenance of DNP in rats.

Objective To investigate the effects of matrix metalloproteinase-3 (MMP-3) in the development of neuropathic pain (NP) in rats.Methods One hundred and eighty male Wistar rats weighing 200-250 g were randomly divided into 4 groups (n =45 each):sham operation group (S group),NP group,MMP-3-siRNA group (Msi group) and MMP-3-siRNA negative control group (NC group).NP was induced by ligation of L5 spinal nerve (SNL).Lentivirus with MMP-3-siRNA was injected intrathecally after SNL in group Msi.Lentivirus with NC-siRNA was injected intrathecally after SNL in group NC.The mechanical pain threshold was measured at day 7,14 and 21 after SNL.The rats were then sacrificed after the last measurement of the mechanical pain threshold.The lumbar segment of the spinal cord (L4-6) was removed for determination of the expression of MMP-3 and TNF-a protein and mRNA by RT-PCR and Western blot.Results The mechanical pain threshold was significantly decreased and the expression of MMP-3 and TNF-α protein and mRNA was up-regulated at each time point in groups NP and NC as compared with group S (P ＜ 0.05).The mechanical pain threshold was significantly higher and the expression of MMP-3 and TNF-α protein and mRNA was lower at each time point in Msi group than in NP group (P ＜ 0.05).Conclusion Up-regulation of the expression of MMP-3 activates microglia and induces the release of TNF-α,resulting in NP in rats.

Objective To evaluate the role of chemokine CXC ligand 13 (CXCL13) in spinal cord in neuropathic pain (NP) in rats.Methods One hundred and eight male Sprague-Dawley rats,weighing 150-200 g,were randomly divided into 4 groups (n =27 each):sham operation group (group S),group NP,small interference RNA (siRNA) negative control group (group NS) and CXCL13-siRNA group (group CS).The animals were anesthetized with intraperitoneal ketamine 50 mg/kg.NP was induced by ligation of L5 spinal nerve (SNL) in groups NP,NS and CS.L5 spinal nerve was only exposed but not occluded in group S.CXCL13-siRNA lentivirus and siRNA negative control lentivirus were injected intrathecally in groups CS and NS,respectively.Mechanical pain threshold was measured at 3,7 and 14 days after SNL.Then the rats were sacrificed and L4-6 segments of the spinal cord were obtained for determination of coexpression of CXCL13 and Neun (by immunofluorescence),activation of astrocytes,and expression of CXCL13 and glial fibrillary acidic protein (GFAP) protein (by Western blot) and mRNA (by RT-PCR) in spinal cord tissues.Results Compared with group S,mechanical pain threshold was significantly decreased and the expression of CXCL13 and GFAP protein and mRNA was up-regulated at each time point after operation in groups NP,NS and CS (P ＜ 0.05).Compared with group NP,mechanical pain threshold was significantly increased and the expression of CXCL13 and GFAP protein and mRNA was down-regulated at each time point after operation in group CS (P ＜ 0.05).There was no significant difference in the indexes mentioned above at each time point after operation between groups NP and NS (P ＞ 0.05).Conclusion CXCL13 is involved in the development and maintenance of NP in rats via activation of astrocytes.

Objective To investigate the effects of protocadherin 20 (PCDH20) in the spinal cord in the development of bone cancer pain (BCP) in rats.Methods Thirty-six SPF female Sprague-Dawley rats,weighing 180-200 g,were randomly divided into 4 groups (n =9 each):sham operation group (group S),BCP group,lentivirus control group (group LC) and PCDH20 siRNA lentivirus group (group P).Control lentivirus and lentivirus containing PCDH20 siRNA 4 μl were injected into the ipsilateral spinal cord in groups LC and P,respectively.One week later,BCP was induced by injection of Walker 256 breast cancer cells into the upper segment of bone marrow of right tibia.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before injection of lentivirus (T1),1 day before BCP (T2),and 7,14 and 21 days after BCP (T3-5).Three rats in each group were sacrificed after measurement of the MWT at 21 day after BCP and the tibia on the operated side was obtained for examination of invasion of the cancer cells with light microscope.The spinal cord was removed for determination of the expression of PCDH20 and postsynaptic density 95 (PSD95) protein (by Western blot) and mRNA (by RTPCR).Results In groups BCP,LC and P,the cancer cells grew out of the bone and destroyed the cortical bone seriously.Compared with group S,the MWT was significantly decreased at T3-5 in groups BCP,LC and P,the expression of PCDH20 and PSD95 protein and mRNA was up-regulated in groups BCP and LC,and the expression of PCDH20 was up-regulated in group P (P ＜ 0.05).Compared with BCP group,no significant change was found in the MWT and expression of PCDH20 and PSD95 protein and mRNA in group LC (P ＞ 0.05),and the MWT was significantly increased at T4,5 and the expression of PCDH20 and PSD95 protein and mRNA was down-regulated in group P (P ＜ 0.05).Conclusion PCDH20 is involved in the development of BCP through regulating the expression of PSD95 in the spinal cord and adjusting the function of excitatory synapse in rats.

Objective:To evaluate the relationship between spinal cord cytoplasmic activation/proliferation-associated protein-1 (Caprin-1)-mediated expression of calmodulin-dependent protein kinase Ⅱ alpha(CaMKⅡα) and pain perception in mice.Methods:Nestin CreERT2 mice and Caprin-1 flox/flox mice were hybridized to obtain Nestin CreERT2; Caprin-1 flox/flox homozygous mice. The mice were divided into 2 groups ( n=5 each) using a random number table method: Nestin CreERT2; Caprin-1 flox/floxsolventcontrol group (SC group) and Caprin-1 gene knockout group (KO group). Tamoxifen 100 mg/kg was intraperitoneally injected for 5 consecutive days to generate inducible knockout of the Caprin-1 gene in KO group. The mechanical paw withdrawal threshold was measured at day 1 before and day 5 after the end of administration. Then the mice were sacrificed, and L 4-6 segments of the spinal cord were removed for determination of the expression of Caprin-1 and CaMKⅡα protein and mRNA (by Western blot or real-time quantitative polymerase chain reaction) and co-expression of Caprin-1 with CaMKⅡα (by immunofluorescent double staining). Results:Compared with SC group, the mechanical paw withdrawal threshold was significantly increased at 5 days after the end of tamoxifen administration, the expression of Caprin-1 and CaMKⅡα protein and mRNA was down-regulated ( P<0.05), and the co-localization expression of Caprin-1 and CaMKⅡα in the spinal dorsal horn was down-regulated in KO group. Conclusions:Caprin-1 is involved in the development of pain perception by promoting CaMKⅡα expression.

The possible mechanism of inhalation anesthetics on the internal auditory impairment of the rat was investigated by determining the effect of nitrous oxide (N20) and isoflurane on the total RNA yield from the cochlea of the rats. Thirty healthy Wistar rats were randomly divided into 3 groups: group C (control group, n=10) with a 3-h unremitting inhalation of 50% O2 group N (ex-periment group, n= 10) with a continuous inhalation of 50% N2O+50% O2for 3 h, and group I (ex-periment group, n=10) with a 3-h sustained inhalation of 2.5% isoflurane. The TRIzol in combination with RNeasy was used to respectively extract the total RNA from cochlea of rats in the 3 groups. Spectrophotometry was used to detect total RNA yield and electrophoresis to detect the quality. The total RNA extracted from the cochlea of the rats in the groups C and N was 7.69 and 6.51 μg, respec- tively. There was a 15% decrease in the N group as compared with group C. The total RNA from the rats in the group I was 7.32 μg, and there was hardly any change in the group as compared with the group C. The value of A260/A280 in groups C, N and I was 2.07, 2.04 and 2.04, respectively, showing a very high RNA purity. The result of gel electrophoresis suggested that there was no degradation in the total RNA. It was suggested that the interference of N2O on the cochlear RNA yield might be one of the reasons which cause an injury of the ear. The isoflurane shows no harm on the heating.

Objective To investigate the role of spinal cord chemokine CXC ligand13(CXCL13) in the formation of rat bone cancer pain(BCP).Methods Twenty healthy female SD rats weighing 160-200 g were divided into four groups(n=5):sham operation group(S),BCP group(BP),small interference RNA(siRNA) negative control(NC-siRNA) group (NC) and CXCL13-siRNA group(CS).Normal saline was given by tibial medullary cavity injection in the S group.The tibial BCP model was established by tibial medullary cavity injection of equivalent Walker-256 breast cancer cells in the group BP,NC and CS.NC-siRNA lentivirus and CXCL13-siRNA lentivirus were injected intrathecally in the group NC and CS respectively.The mechanical pain threshold was measured on 1 d before model construction and on postoperative 7,9,14,21 d.The rats were killed after pain threshold measurement.The spinal cord and tibial tissue were taken.The co-expression of spinal CXCL13,microglia specific marker Iba-1 and neuron specific neucleoprotein NeuN was determined by using the immunofluorescence double standard staining,and expressions of CXCL13 and ionized calcium binding adaptor molecule-1 (Iba-1) protein and mRNA in spinal cord were detected by Western blot and RT-PCR;the HE staining microscopy was adopted to observe the tibial bone structure destroy situation.Results Compared with group S,the mechanical pain threshold in theBP group and NC group was decreased on 7-21 d after inoculation,CXCL13 expression in neuron was significantly increased and microglia was obviously activated,the expression of CXCL13 and Iba-1 protein and mRNA was significantly elevated (P＜0.05);compared with the NC group,the mechanical pain threshold on 9-21 d after model construction in the CS group was significantly increased,CXCL13 expression in neurons was significantly decreased,microglia activation was decreased and expression of CXCL13 and Iba-1 protein and mRNA was significantly decreased(P＜0.05);HE staining showed that the model groups appeared the tumor growth in bone marrow cavity,moreover which was eroded outwards and destroyed bone cortex,but no abnormality was found in the S group.Conclusion Spinal cord CXCL13 is involved in the BCP formation in rats by activating microglia.

This study was aimed to investigate the effect of sinomenine on the expression of tumor suppressor gene P 16 and P53 in rats with lung cancer.A total of 40 male SD rats were treated by left-lung vein injection of WALKER-256 cell suspension to establish transplanted lung cancer model.After 3 weeks,30 rats screened of tumor were randomly divided into the model group,cyclophosphamide (CP) group and the sinomenine treatment group.Another 10 healthy SD rats were set as the normal control group.Sinomenine treatment group was treated with the subcutaneous injection of 10％ sinomenine hydrochloride for 10 weeks.CP was injected in the CP group as positive control.The same amount of normal saline was injected in the normal control group and the model control group.After 10 weeks of treatments,lung tumors of each group were removed to measure the tumor volume and weight.And the tumor inhibition rate was calculated.Then,flow cytometry was used to detect the proportion of WALKER-256 cells in tumor tissues in G1,G2,M and S around four cycles.Immunohistochemistry was adopted to detect positive expression rates of P16 and P53 protein.Reverse transcription polymerase chain reaction (RT-PCR) were used to detect expression of P16mRNA and P53mRNA.The results showed that compared with the model control group,the inhibition rate of sinomenine group was 30.15％;the positive expression rate of P16mRNA and P53mRNA protein were significantly decreased;expressions of P 16mRNA and P53mRNA were lower;tumor volume and tumor weight in S period got down significantly.The rates of cells in G1 and G2 periods got higher (P＜0.05).It was concluded that sinomenine may inhibit the differentiation and proliferation of WALKER-256 transplanted lung cancer cells in rats by regulating the expression of tumor suppressor gene P 16 and P53,regulating the ratio of cells in G1,G2 and S periods.