Down-regulation Of Fenofibrate On Subconjunctival Fibrosis In Rats And Its Mechanism

Popurse:Subconjunctival tissue fibrosis is a common clinical disease,which often seen in need of long-term drop with preservative benzalkonium chloride eye drops to lower intraocular pressure in patients with glaucoma,and the poor control of intraocular pressure still requires surgery,but postoperative local scar problems are likely to cause the failure of surgery.Previous studies believed that fenofibrate had anti-fibrosis effect in other tissues and organs such as heart,liver,kidney,lung,etc.This study mainly discussed its anti-fibrosis effect and its mechanism in the subconjunctival tissues of rats.Methods:The experiment was divided into cell experiment and animal experiment.The subconjunctival tissues of adult male SD rats were selected to be used in the cell experiment,and the Primary stromal cells were digested and cultured.The experiments were conducted in the P2 generation of the cell,which were divided into the normal(Ctrl)group,modeling(TGFβ)group,vehicle control(V)group,and 0.2%fenofibrate(Feno)group.Then the expression levels of genes and proteins were observed by qRT-PCR and Western Blot(WB)of FN-1、α-SMA、PPARα、Smad2 and Smad3.24 adult male SD rats were used for animal experiment,divided into normal group(Ctrl),BAC modeling(BAC)of 0.01%,vehicle control group(V),0.2%fenofibrate(Feno)group,respectively made use of slit lamp photographic to observe ocular surface damage、paraffin embedding slice Hematoxylin-eosin staining(H&E)and Masson staining to observe the situation of collagen deposition.The number of conjunctival goblet cells was observed with an iodate-schiff stain(PAS stain).FN-1,α-SMA changes were observed after repairing antigen in histochemical staining.The changes of FN-1、α-SMA、PPARα、TGFβ2、Smad2 and Smad3 at protein level were detected by WB after the proteins in subconjunctiva tissues were collected.The changes of PPAR α、TGF β2、Smad2 and Smad3 at the gene level were observed by qRT-PCR after RNA was collected from subconjunctiva tissue.Results:In cell experiments,downstream Smad2/3 were activated after the addition of TGFβ2 at the gene and protein levels,followed by the upregulation of FN-1、α-SMA levels,which are classical fibrosis markers,and the reduction of PPARα,and the addition of fenofibrate could reverse the pathological disorders of the above indicators.In animal experiments,no obvious eye surface damage was observed in each group under white light and blue light after fluorescein sodium staining in slit lamp photography.Masson staining showed that the blue staining area of BAC group was larger and darker,while that of fenofibrate group was down-regulated.In immunohistochemical staining,the BAC group’s FN-1 and α-SMA positive cells increased significantly,while the fenofibrate group decreased,WB results further validate the above changes.qRT-PCR and WB showed the decrease of PPARa in the BAC group and the activation of TGFβ2 and Smad2/3,while the increase of PPARa and the down-regulation of TGFβ2、Smad2/3 at gene and protein levels in the fenofibrate group.Conclusion:Fenofibrate down-regulated the level of subconjunctival tissue fibrosis of rats by down-regulating the TGFβ2/Smad2/3 pathway.