The Anti-fibrosis Role Of MiR-29c In Rat Leptomeninge After Experimental Subarachnoid Hemorrhage

BackgroudSubarachnoid hemorrhage(SAH) is a type of acute cerebrovascular disease with incidence lower than cerebral infarction and cerebral hemorrhage. Chronic communicating hydrocephalus is one of the common complications after subarachnoid hemorrhage, literature reported incidence was 8%-67%, which can seriously affect the prognosis of patients. It is accepted that leptomeninges fibrosis is the main cause of hydrocephalus after subarachnoid hemorrhage.MicroRNAs are a kind of non-coding endogenous single chain small RNA molecules with the length about 20-24 nucleotides. They inhibit the transcription or prompt the degradation of target gene by combining target gene’s mRNA. MiR-29 family have the members of miR-29 a, miR-29-1 b, miR-29-2 b, miR-29 c.In addition to participate in tumor growth、cell apoptosis and differentiation process, inhibition of tissue fibrosis is the main function of miR-29 family reported by literature.The expression of mir-29 families are decreased in the process of tissue fibrosis including the liver, kidneys, heart, lungs, etc. Our previous studies have found that the expression of miR-29c were also decreased in the leptomeninges of experimental subarachnoid hemorrhage rats. The expression changes of miR-29a and miR-29b has no statistical significance. This study using a lentivirus to elevate the expression of miR-29c, observation miR-29 c on the influence of the leptomeninges fibrosis.ObjectiveTo explore the role of miR-29c in rat leptomeningeal fibrosis after subarachnoid hemorrhage.MethodsA total of 26 healthy Sprague-Dawley (SD) rats were randomly divided into sham group (n=6), empty lentiviral group (n=8), and LV-rno-miRNA-29c group (n=12). 5μL saline, empty lentivirus and LV-rno-miRNA-29c were respectively injected into the lateral cerebral ventricle of rats in each group. The SAH models were induced by injecting autologous blood twice into the cisterna magna, and 21 days later the rats were killed. Realtime PCR was used to detect the expressions of TGF-β1 and miR-29c. Masson staining was performed to observe collagen fiber. Elisa was adopted to measure the level of PICP in CSF.Results1. Realtime PCR showed that the expression of TGF-β1mRNA in LV-rno-miRNA-29c group was higher than Empty lentiviral group by (0.0209±0.0018VS0.0025±0.0008, P<0.05),while the expression of miRNA-29c was lower by (0.0148±0.0054 VS 0.0177±0.0031, P<0.05)2. Elisa showed that,compared with Empty lentiviral group, the expression of PICP was reduced in LV-rno-miRNA-29c group (P<0.01)3. Masson staining showed that the leptomeningeal fibrosis in Empty lentiviral group group with less expression of miRNA-29c was more severe than that in LV-rno-miRNA-29c group.Conclusions1. Rats with SAH have the higher experssion of TGF-01 and the lower experssion of miR-29c in leptomeningeal.2. The expression of miR-29c was successfully elevated by lentivirus in LV-rno-miRNA-29c group.3. High expression of miR-29c may have potential therapeutic effects for leptomeningeal fibrosis by inhibiting collagen synthesis after SAH.