Antifibrotic role of low-dose mitomycin-c-induced cellular senescence in trabeculectomy models

Abstract

We assessed whether mitomycin-C (MMC) has different antifibrotic mechanisms in trabeculectomy wound healing. Methods We identified 2 concentrations of MMC as "low-dose" by using WST-1 assay, Lactic dehydrogenase assay, and fluorescence-activated cell sorting flow cytometry. Senescenceassociated β-galactosidase (SA-β-gal) and fibrotic gene expression was examined through immunocytochemistry, flow cytometry, real-time quantitative reverse transcription polymerase chain reaction, Western blotting, zymography, and modified scratch assay in vitro. In vivo, 0.1 mL of MMC or normal saline was injected to Tenon's capsule before trabeculectomy in a rabbit model. SA-β-gal expression, apoptotic cell death, and collagen deposition in sites treated and not treated with MMC were evaluated using terminal dUTP nick end labeling assay and histochemical staining. Bleb function and intraocular pressure (IOP) levels were examined 3, 7, 14, 21, 28, and 35 days after trabeculectomy. Results In vitro, human Tenon's fibroblast (HTF) senescence was confirmed by observing cell morphologic change, SA-β-gal accumulation, formation of senescence-associated heterochromatin, increased p16 INK4a and p21 CIP1/WAF1 expression, lower percentage of Ki-67-positive cells, and decreased COL1A1 release. Increased expression of α-SMA, COL1A1, and Smad2 signaling in TGF-β1-induced stress fibers were passivated in senescent HTFs. In addition, cellular migration enhanced by TGF-β1was inactivated. In vivo, histological examination indicated increased SA-β-gal accumulation, lower apoptosis ratios, and looser collagen deposition in sites treated with 0.2 μM MMC. Low-dose MMC-induced cellular

Protective effect of human amniotic membrane extract against hydrogen peroxide‐induced oxidative damage in human dermal fibroblasts

“…In addition, despite the observed irregularities in cell growth chart of H 2 O 2 ‐induced treated cells, AME maintained the normal fibroblast cell growth chart pattern as both pre‐ and post‐treatment regimen. Numerous studies revealed that aged cells undergo a cell cycle arrest but they do not enter the apoptotic phase[18, 21–24]. Our similar result showed that the ageing regimen (200 μM H 2 O 2 treatments for 2 h) has nonapoptotic effect on HFFs.…”

Dihydroartemisinin Inhibits TGF-β-Induced Fibrosis in Human Tenon Fibroblasts via Inducing Autophagy

“…To mimic the formation of HS in vitro, HTFs were stimulated with 10 ng/mL TGF-β (Sigma-Aldrich; Merck KGaA) as previously described. 19 , 20 The present study was approved by the Ethics Committee of Harbin Medical University. Written informed consent was obtained from all patients.…”

Resultado da ação da ciclofosfamida x mitomicina c em coelhos submetidos à trabeculectomia

“…Os fibroblastos ativos, conhecidos como miofibroblastos, são células que têm um papel fundamental na cicatrização normal e que tendem a desaparecer nas fases mais tardias da trabeculectomia. No entanto eles permanecem em alguns casos e causam cicatrização excessiva, incluindo a formação das bolhas encistadas em trabeculectomias (16).…”

“…Como ação antineoplásica, ela funciona como um agente alquilante que causa uma ligação cruzada do DNA e inibe o RNA e a síntese de proteínas. Topicamente, atua como um agente antiproliferativo, inibindo a atividade de fibroblastos (15,16). O efeito da MMC na cicatrização tem sido investigado, porém o exato mecanismo da sua ação antiproliferativa em fibroblastos permanece ainda um pouco obscuro (16).…”

“…Topicamente, atua como um agente antiproliferativo, inibindo a atividade de fibroblastos (15,16). O efeito da MMC na cicatrização tem sido investigado, porém o exato mecanismo da sua ação antiproliferativa em fibroblastos permanece ainda um pouco obscuro (16).…”