| Objective: It is reported that expression change of long noncoding RNA(lnc RNA)and factors influencing lnc RNA expression are related with the nervous system diseases.The aim of the project is to study the effect of lnc RNA uc.48+ si RNA on diabetic neuropathic pain(DNP)mediated by calcitonin gene related peptide(CGRP)and purinergic 2X7 receptor(P2X7R)of dorsal root ganglia(DRGs)and spine cord(SC)in type 2 diabetic rats,and to find its possible mechanism,and provide new experimental evidences for the prevention and treatment of DNP.Methods: The male Sprague-Dawley rats were fed with a high-fat and fructose diet for 4 weeks to develop insulin resistance,then injected twice intraperitoneal streptozocin(STZ)(30mg/kg).The fasting blood glucose(FBG)of rats was detected and the rats having FBG?11.1 mmol/L were selected as the model of type 2 diabetic rats.And the mechanical withdrawal threshold(MWT)and the thermal withdrawal latency(TWL)of the type 2 diabetic rats were measured after STZ injection for 3 weeks.Those rats of which MWT and TWL were less than 80%of the baseline were selected as the type 2 DNP rats.The type 2 DNP rats were randomly divided into 4 groups(n=36):(1)Normal control group(Control);(2)DNP rats treated with saline group(DNP);(3)DNP rats treated with uc.48 + si RNA group(DNP+uc.48+ si RNA);(4)DNP rats treated with scramble si RNA group(DNP+scramble si RNA).After 3 days of intrathecal injection with uc.48+ small interfering RNA,observe changes of MWT and TWL.Meanwhile DRGs and SC of the lumbar segment 4-6 were removed.Reverse transcription-polymerase chain reaction(RT-PCR),immunohistochemistry(IHC)and Western blot(WB)were used to determinate the expression of CGRP and P2X7 R.And the phosphorylation of P38 and ERK1/2 of the DRGs and SC were observed by WB.Determinations of serum interleukin-1?(interleukin,IL-1?)and tumor necrosis factor ?(TNF-?)levels were measured by enzyme-linked immunosorbent assay(ELISA)method.Results: After the type 2 DNP rat model established successfully,the MWT and TWL of DNP group compared with Control group significantly decreased(P<0.01).And after 3 days of intrathecal injection with uc.48+ small interfering RNA,the MWT and TWL of DNP rats significantly increased(P<0.01).With the methods of RT-PCR,IHC and WB,the result showed that the expression of lnc RNAuc.48+,CGRP,P2X7,OX-42 or GFAP in DRGs and SC of DNP group and DNP+scramble si RNA group was much higher than that of Control group(P<0.01),but the expression in DNP+uc.48+ si RNA group decreased significantly compared with DNP group(P<0.01).The phosphorylation of p38 and ERK1/2 of DRGs and SC in DNP group was significantly raised compared with Control group(P<0.01).Uc.48 + si RNA can significantly reduce the phosphorylation of p38 and ERK1/2 pathway in DRGs and SC of DNP rats(P<0.01).ELISA results showed that small interfering uc.48+ could significantly decrease the high level of IL-1? and TNF-? in serum of DNP rats(P < 0.01).Conclusion: Lnc RNA uc.48+ may play an important role in transmission of DNP.Small interfering lnc RNA uc.48+ might alleviate the hyperalgesia and allodynia of DNP rats by suppressing the the expression of CGRP and P2X7 in DRGs and SC of DNP rats. |
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