MiR-146a reduces fibrosis after glaucoma filtration surgery in rats.

PURPOSE: To explore the impact of microRNA 146a (miR-146a) and the underlying mechanisms in profibrotic changes following glaucoma filtering surgery (GFS) in rats and stimulation by transforming growth factor (TGF)-ß1 in rat Tenon's capsule fibroblasts. METHODS: Cultured rat Tenon's capsule fibroblasts were treated with TGF-ß1 and analyzed with microarrays for mRNA profiling to validate miR-146a as the target. The Tenon's capsule fibroblasts were then respectively treated with lentivirus-mediated transfection of miR-146a mimic or inhibitor following TGF-ß1 stimulation in vitro, while GFS was performed in rat eyes with respective intraoperative administration of miR-146a, mitomycin C (MMC), or 5-fluorouracil (5-FU) in vivo. Profibrotic genes expression levels (fibronectin, collagen Iα, NF-KB, IL-1ß, TNF-α, SMAD4, and α-smooth muscle actin) were determined through qPCR, Western blotting, immunofluorescence staining and/or histochemical analysis in vitro and in vivo. SMAD4 targeting siRNA was further used to treat the fibroblasts in combination with miR-146a intervention to confirm its role in underlying mechanisms. RESULTS: Upregulation of miR-146a reduced the proliferation rate and profibrotic changes of rat Tenon's capsule fibroblasts induced by TGF-ß1 in vitro, and mitigated subconjunctival fibrosis to extend filtering blebs survival after GFS in vivo, where miR-146a decreased expression levels of NF-KB-SMAD4-related genes, such as fibronectin, collagen Iα, NF-KB, IL-1ß, TNF-α, SMAD4, and α-smooth muscle actin(α-SMA). Additionally, SMAD4 is a key target gene in the process of miR-146a inhibiting fibrosis. CONCLUSIONS: MiR-146a effectively reduced TGF-ß1-induced fibrosis in rat Tenon's capsule fibroblasts in vitro and in vivo, potentially through the NF-KB-SMAD4 signaling pathway. MiR-146a shows promise as a novel therapeutic target for preventing fibrosis and improving the success rate of GFS.

17ß-estradiol inhibits TGF-ß-induced collagen gel contraction mediated by human Tenon fibroblasts via Smads and MAPK signaling pathways.

AIM: To investigate the impact of 17ß-estradiol on the collagen gels contraction (CGC) and inflammation induced by transforming growth factor (TGF)-ß in human Tenon fibroblasts (HTFs). METHODS: HTFs were three-dimensionally cultivated in type I collagen-generated gels with or without TGF-ß (5 ng/mL), 17ß-estradiol (12.5 to 100 µmol/L), or progesterone (12.5 to 100 µmol/L). Then, the collagen gel diameter was determined to assess the contraction, and the development of stress fibers was analyzed using immunofluorescence staining. Immunoblot and gelatin zymography assays were used to analyze matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) being released into culture supernatants. Enzyme-linked immunosorbent assay (ELISA) and reverse transcription-quantitative polymerase chain reaction (RT-PCR) were used to detect interleukin (IL)-6, monocyte chemoattractant proteins (MCP)-1, and vascular endothelial growth factor (VEGF) in HTFs at the translational and transcriptional levels. The phosphorylation levels of Sma- and Mad-related proteins (Smads), mitogen-activated protein kinases (MAPKs), and protein kinase B (AKT) were measured by immunoblotting. Statistical analysis was performed using either the Tukey-Kramer test or Student's unpaired t-test to compare the various treatments. RESULTS: The CGC caused by TGF-ß in HTFs was significantly inhibited by 17ß-estradiol (25 to 100 µmol/L), and a statistically significant difference was observed when comparing the normal control group with 17ß-estradiol concentrations exceeding 25 µmol/L (P<0.05). The suppressive impact of 17ß-estradiol became evident 24h after administration and peaked at 72h (P<0.05), whereas progesterone had no impact. Moreover, 17ß-estradiol attenuated the formation of stress fibers, and the production of MMP-3 and MMP-1 in HTFs stimulated by TGF-ß. The expression of MCP-1, IL-6, and VEGF mRNA and protein in HTFs were suppressed by 100 µmol/L 17ß-estradiol (P<0.01). Additionally, the phosphorylation of Smad2 Smad3, p38, and extracellular signal-regulated kinase (ERK) were downregulated (P <0.01). CONCLUSION: 17ß-estradiol significantly inhibits the CGC and inflammation caused by TGF-ß in HTFs. This inhibition is likely related to the suppression of stress fibers, inhibition of MMPs, and attenuation of Smads and MAPK (ERK and p38) signaling. 17ß-estradiol may have potential clinical benefits in preventing scar development and inflammation in the conjunctiva.

Anti-scarring effects of conbercept on human Tenon's fibroblasts: comparisons with bevacizumab.

BACKGROUND: Safely inhibiting the formation of scar in the glaucoma filtration surgery (GFS) has always been an issue for clinical glaucoma doctors. Anti-vascular endothelial growth factor (VEGF) agents can reduce angiogenesis, and anti-placental growth factor (PIGF) agents can affect reactive gliosis. However, the effect of conbercept, which can bind to both VEGF and PIGF, on human Tenon's fibroblasts (HTFs) is unknown. METHODS: HTFs were cultured in vitro and treated with conbercept or bevacizumab (BVZ). No drug was added to the control group. The effects of drugs on cell proliferation were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the collagen type I alpha1(Col1A1) mRNA expression level was measured using quantitative polymerase chain reaction (qPCR). HTF cell migration after drug interventions was evaluated using the scratch wound assay along with the measurement of the expression levels of VEGF and PIGF in human umbilical vein endothelial cells (HUVECs) using enzyme-linked immunosorbent assay, as well as the detection of the VEGF(R) mRNA expression level in HTFs using qPCR. RESULTS: After the addition of conbercept (0.01, 0.1, and 1 mg/mL) to the cultured HTFs or HUVECs, no significant cytotoxicity was observed compared with the control group, while the cytotoxicity of 2.5 mg/mL BVZ on HTFs was obvious. Conbercept significantly inhibited HTF cell migration and Col1A1 mRNA expression level in HTFs. It was superior to BVZ in inhibiting HTF migration. After the intervention with conbercept, the expression level of PIGF and VEGF in HUVECs significantly decreased; and the inhibitory effect of conbercept on the expression level of VEGF in HUVECs was weaker than that of BVZ. Conbercept was more advantageous than BVZ in inhibiting the expression level of VEGFR-1 mRNA in HTFs. However, its effect in terms of inhibiting the expression level of VEGFR-2 mRNA in HTFs was weaker than that of BVZ. CONCLUSION: The results suggested the low cytotoxicity and significant anti-scarring effect of conbercept in HTF with significant anti-PIGF and inferior anti-VEGF effects compared with BVZ, thus providing a better understanding of the role of conbercept in the GFS wound healing process.

Effects of EW-7197 on the proliferation and migration of TGF-β1 induced human Tenon fibroblasts and its mechanism / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of ALK5 inhibitor EW-7197 on the proliferation and migration of human Tenon fibroblasts(HTFs)induced by transforming growth factor-β1(TGF-β1)and its mechanism.METHODS: The cell proliferation rate was detected by MTS assay, and the optimal concentration and time of EW-7197 were explored. Then HTFs were divided into three groups: normal control group, TGF-β1 induced group and TGF-β1+EW-7197 group. Cell migration was observed by Transwell assay. The protein expression levels of Fibronectin, α-SMA, as well as the phosphorylated Smad2, Smad3(p-Smad2, p-Smad3)were measured by Western blot.RESULTS: MTS assay showed that the proliferation rate of cells treated with 6.0 μmol/L EW-7197 for 24h was the lowest(all P&#x003C;0.01). Transwell assay showed that the migrated number of HTFs in TGF-β1 induced group was 228.0±17.0/field, which was significantly more than that in normal control group(149.0±15.0/field)and TGF-β1+EW-7197 group(46.0±8.0/field; all P&#x003C;0.01). Western blot showed that the protein relative expression levels of Fibronectin, α-SMA and p-Smad2, p-Smad3 of HTFs in TGF-β1 induced group were significantly higher than that in normal control group and TGF-β1+EW-7197 group(all P&#x003C;0.001).CONCLUSION:EW-7197 can suppress the proliferation and migration of TGF-β1-induced HTFs through TGF-β/Smad signaling pathways.

Emerging Evidence of Noncoding RNAs in Bleb Scarring after Glaucoma Filtration Surgery.

PURPOSE: To conduct a narrative review of research articles on the potential anti- and pro-fibrotic mechanisms of noncoding RNAs following glaucoma filtration surgery. METHODS: Keyword searches of PubMed, and Medline databases were conducted for articles discussing post-glaucoma filtration surgeries and noncoding RNA. Additional manual searches of reference lists of primary articles were performed. RESULTS: Fifteen primary research articles were identified. Four of the included papers used microarrays and qRT-PCR to identify up- or down-regulated microRNA (miRNA, miR) profiles and direct further study, with the remainder focusing on miRNAs or long noncoding RNAs (lncRNAs) based on previous work in other organs or disease processes. The results of the reviewed papers identified miR-26a, -29b, -139, -155, and -200a as having anti-fibrotic effects. In contrast, miRs-200b and -216b may play pro-fibrotic roles in filtration surgery fibrosis. lncRNAs including H19, NR003923, and 00028 have demonstrated pro-fibrotic effects. CONCLUSIONS: Noncoding RNAs including miRNAs and lncRNAs are emerging and promising therapeutic targets in the prevention of post-glaucoma filtration surgery fibrosis.

Inhibitory effect of epigallocatechin gallate on human Tenon fibroblasts and its mechanism / 中华实验眼科杂志

Objective:To investigate the effect of epigallocatechin gallate (EGCG) on the activation of human Tenon fibroblasts (HTFs) and its mechanism.Methods:Tenon capsule tissues from nine eyes of nine advanced primary open angle glaucoma patients during trabeculectomy were obtained for primary cell culture.HTFs harvested were identified by immunofluorescence staining for vimentin and keratin.Cells at passage 4-6 were used for experiment.Viability of HTFs treated with EGCG at 0, 10, 20, 30, 40, 50, 60, 70 and 80 μmol/L was detected by cell counting kit-8 (CCK-8) assay.The cells were divided into blank control group, transforming growth factor (TGF)-β1-induced group, and EGCG-treated group, which were cultured in normal medium, medium containing 10 ng/ml TGF-β, medium containing 10 ng/ml TGF-β+ 50 μmol/L EGCG, respectively.The proliferation rate of HTFs was detected by BrdU labeling assay.Cell migration was observed by scratch wound healing assay.The expression of α-smooth muscle actin (α-SMA) was measured by immunofluorescence staining.The protein relative expression levels of Smad2/3, phosphoinositide-3-kinase (PI3K), protein kinase B (Akt) as well as the phosphorylated Smad2/3 (p-Smad2/3) and phosphorylated Akt (p-Akt) were measured by western blot.This study was approved by the Ethics Committee of Guangdong Provincial People's Hospital (NO.GDREC2019331H[R1]).Results:The HTFs harvested had spindle shape, grew regularly and were vimentin-positive.CCK-8 assay showed that there was no significant difference in the variability of HTFs treated with EGCG at 10, 20, 30, 40 and 50 μmol/L in comparison with 0 μmol/L EGCG treatment (all at P<0.05). BrdU labeling assay showed that cell proliferation in the TGF-β1-induced group was (66.37±12.65)%, which was significantly higher than (14.75±12.33)% in EGCG-treated group ( P<0.05). Three days after scratch, the relative scratch area in the TGF-β1-induced group was (47.33±12.22)%, which was significantly lower than (92.67±4.04)% in the EGCG-treated group ( P<0.05). Immunofluorescence assay showed that α-SMA fluorescence was significantly enhanced in the TGF-β1-induced group in comparison with the blank control group, which was reduced to blank control group level in EGCG-treated group.Western blot analysis showed that there were significant differences in the relative expression levels of p-Smad2/3, PI3K and p-Akt protein among the various groups ( F=58.820, 121.153, 69.289; all at P<0.001). The relative expressions of p-Smad2/3, PI3K and p-Akt in the TGF-β1-induced group were significantly higher than those in the blank control group, 10 μmol/L and 50 μmol/L EGCG-treated groups (all at P<0.05). Conclusions:EGCG can suppress TGF-β1-induced HTFs activation through Smad and PI3K/Akt signaling pathways.

K-115 enhances autophagic activity and attenuates TGF-β1-induced activation of human Tenon's fibroblasts / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the influence of K-115 on the proliferation and migration of human Tenon's fibroblasts(HTFs)and to access the possible mechanism. Furthermore, to provide new ideas for anti-scar treatment after glaucoma surgery.METHODS: The Tenon capsule tissues were collected from patients who underwent glaucoma surgery in Hebei General Hospital from September 2018 to September 2019. Primary culture of HTFs was performed by tissue block method. The transforming growth factor-β1(TGF-β1)was used to induce HTFs activation that can mimic glaucoma filtration surgery. The cells were treated with K-115 and divided into 4 groups: the control group was treated with dimethyl sulfoxide(DMSO); TGF-β1 group was treated with 10μg/L TGF-β1 for 24h; TGF-β1 +5 K-115 group was pretreated with 5μmol/L K-115 for 2h and then treated with 10μg/L TGF-β1 for 24h; TGF-β1+10 K-115 group was pretreated with 10μmol/L K-115 for 2h and then 10μg/L TGF-β1 was added for 24h. Cell proliferation was observed by cell proliferation experiment. The migration ability of cells was detected by scratch test. The formation of autophagosomes was observed by transmission electron microscopy. Apoptosis was visualized by Hoechst 33342/PI staining.RESULTS: Cell proliferation experiment revealed that K-115 could inhibit the proliferation of HTFs induced by TGF-β1. Scratch test suggested that K-115 could inhibit the migration of HTFs induced by TGF-β1. Transmission electron microscope results showed that K-115 could enhance autophagy of HTFs induced by TGF-β1. Hoechst 33342/PI staining suggested that K-115 did not induce apoptosis.CONCLUSIONS: K-115 may regulate the proliferation and migration of HTFs induced by TGF-β1 by increasing autophagy rather than inducing apoptosis.

[Pirfenidone inhibits proliferation of rabbit tenon fibroblasts by down-regulating TGF-ß3 in the TGF-ß/Smad pathway].

OBJECTIVE: To investigate the molecular mechanism by which pirfenidone inhibits scar formation through the TGF-ß/Smad pathway. METHODS: Cultured rabbit tenon fibroblasts (RTFs) were treated with different concentrations of pirfenidone to determine its initial active concentration and optimum concentration of pirfenidone for inhibiting RTF proliferation using CCK-8 assay. In RTFs treated with pirfenidone at the initial and optimal concentrations, expressions of TGF-ß3, collagen I and collagen III were examined with both immunofluorescence assay and Western blotting, and their mRNA expression levels were detected using RT-PCR. RESULTS: The initial and optimal concentrations of pirfenidone for inhibiting RTF proliferation were 0.1 mg/mL and 0.27 mg/mL, respectively. In RTFs treated with pirfenidone at the two concentrations for 24 h, both immunofluorescence assay and Western blotting showed significantly lowered protein expressions of TGF-ß3, collagen I and collagen III as compared with those in the control group (P < 0.05). The mRNA expressions of TGF-ß3, collagen I and collagen III in the RTFs were also significantly lowered after treatment with pirfenidone at the initial and optimal concentrations (P < 0.05). CONCLUSIONS: Pirfenidone concentration-dependently inhibits the proliferation of RTFs possibly by down-regulating the expression of TGF-ß3 in the TGF-ß/Smad pathway.

Forkhead domain inhibitory-6 attenuates subconjunctival fibrosis in rabbit model with trabeculectomy.

Antiproliferative therapies are crucially important for improving the success rate of the glaucoma filtration surgeries. In this study, we investigated the potential efficacy of Forkhead Domain Inhibitory-6 (FDI-6) in inhibiting post-trabeculectomy subconjunctival fibrosis. In vitro, the effect of FDI-6 (10 µM) on fibrotic response and its underlying mechanism were investigated in rabbit tenon's fibroblasts (RTFs) treated with or without transforming growth factor-ß1 (TGF-ß1, 20 ng/mL). In vivo, FDI-6 (40 µM) was injected subconjunctivally to a rabbit trabeculectomy model. Intraocular pressure (IOP) changes were monitored within the 14-day period post-surgery. Bleb morphology and subepithelial fibrosis at the operating area were evaluated with slit lamp and confocal microscopic examinations and with histologic examinations. The results showed that, in cell culture studies, FDI-6 suppressed the proliferation, migration, collagen gel contraction and the expression levels of fibronectin (FN) and α-smooth muscle actin (α-SMA) in RTFs with TGF-ß treatment by down-regulating the TGF-ß1/Smad2/3 signaling pathway. In animal studies, the IOPs of the FDI-6-treated group were significantly lower than those of the saline-treated group after trabeculectomy. The FDI-6-treated eyes showed a better bleb appearance with fewer blood vessels compared to the saline-treated eyes. The analysis of confocal microscopy in vivo and histopathology revealed that subconjunctival fibrosis after trabeculectomy was significantly attenuated in the FDI-6-treated group compared to the controls. In conclusion, our studies indicate that FDI-6 exerts an inhibitory effect on subconjunctival fibrosis caused by trabeculectomy, holding potentials as a new antiproliferative agent used in anti-glaucoma filtration surgeries in the future.

Effects of Qingguang'an containing serum on the expression levels of autophagy-related genes in human Tenon's fibroblasts induced by transforming growth factor beta 1.

OBJECTIVE: To explore the effects of Qingguang'an () containing serum on the expression levels of autophagy related genes in the transforming growth factor beta 1 (TGF-ß1)-activated human Tenon's fibroblasts (HTFs). METHODS: (a) Primary HTFs were stimulated by TGF-ß1 and underwent immunohistochemistry, which established a cell model after Glaucoma filtration surgery (GFS). (b) The cell models were divided into 4 group: normal group (normal cells), model group (+TGF-ß1),treatment group (+TGF-ß1+ medicated serum), and positive control group (TGF-ß1+ rapamycin). Then, Qingguang'an medicated serum with optimum concentration was added to the corresponding group. The autophagy positive cells were identified by the Cyto-ID autophagy detection kits under fluorescent microscope and Cytation 5 multifunctional instrument for cell imaging. And the mean fluorescence intensity of autophagy positive cells was determined by flow cytometry. The expression levels of autophagy related genes － Beclin-1, autophagy related gene 5 (ATG-5), and microtubule-associated protein 1 light chain 3 (LC-3Ⅱ were detected by quantitative reverse transcription-polymerase chain reaction and Western blot analysis. RESULTS: Compared with the normal group and the model group, the relative mRNA expression levels of autophagy-related genes (Beclin-1, ATG-5 and LC-3Ⅱ in the experimental group were notably increased (P < 0.05, P < 0.01), and with the extension of treatment time, it had an increasing trend (48 h was more obvious), which showed a certain time dependency; the protein expression levels of autophagy-related genes (Beclin-1, ATG-5, and LC-3Ⅱ were significantly increased in the experimental group (P < 0.05, P < 0.01). With the prolongation of treatment time, there was an increasing trend (48 h was relatively obvious), and it revealed a certain time dependency. CONCLUSION: The Qingguang'an medicated serum could up-regulate autophagy related genes (Beclin1, ATG5, and LC3Ⅱ in the TGF-ß1-activated HTFs.

Epigallocatechin-3-gallate increases autophagic activity attenuating TGF-ß1-induced transformation of human Tenon's fibroblasts.

We previously found that epigallocatechin-3-gallate (EGCG) could inhibit the myofibroblast transformation of human Tenon's fibroblasts, however, the underlying mechanism remained unclear. We therefore investigated whether the autophagic regulation involved in the anti-fibrotic function of EGCG. The fibroblasts were subjected to transforming growth factor beta-1 (TGF-ß1) induction followed by EGCG treatments. The autophagic flux was examined by transmission electron microscopy and autophagic flux analysis. The levels of autophagy-related proteins (LC3ß and p62) and alpha-smooth muscle actin (α-SMA) were measured by Western blot and immunofluorescence. Results showed that TGF-ß1 partially inhibited the autophagic function of Tenon's fibroblasts. But this inhibition effect was rescued by LY2157299, a TGF-ßR1 selective inhibitor. Compared with the cells treated with TGF-ß1 alone, EGCG treatments increased the amount of autophagosomes and autolysosomes, evaluated the ratio of LC3-II to LC3-I and decreased p62 level. Our results indicated that EGCG could recover the activity of autophagy in the TGF-ß1-treated cells. Moreover, treatments with EGCG significantly decreased the α-SMA expression. Taken together, these findings revealed that autophagic regulation involved in the action of EGCG against TGF-ß1-induced transformation of Tenon's fibroblasts. Through increasing intracellular autophagy, EGCG could be a potential anti-fibrotic reagent for preventing subconjunctival fibrosis after glaucoma filtration surgery.

Epigallocatechin-3-gallate (EGCG) inhibits myofibroblast transformation of human Tenon's fibroblasts.

Myofibroblast transformation of human Tenon's fibroblasts severely challenges the outcome of glaucoma filtration surgery. epigallocatechin-3-gallate (EGCG) is considered as a potential reagent to overcome this issue for its anti-fibrosis effect on various human diseases, but it is unclear on the fibrosis of Tenon's fibroblasts. This study was conducted to investigate the effect of EGCG on TGF-ß1-induced myofibroblast transformation of human Tenon's fibroblasts. The human Tenon's fibroblasts were incubated in the medium containing 10 ng/mL TGF-ß1, and subsequently treated with EGCG or mitomycin C (MMC). The cell proliferation and migration were analyzed. The expression of alpha-smooth muscle actin (α-SMA), type I collagen (Col-I), and p-Smad2/3 were also evaluated. It showed that EGCG and MMC strongly inhibited the elevation in cell number in tissue explants compared to the tissues treated with TGF-ß1 alone. Scratch-Wound assay showed that 48 h after TGF-ß1 induction, only 10% of the wound width remained. But cells treated with EGCG still showed over 93% wound width. Further, EGCG effectively inhibited TGF-ß1-induced expression of α-SMA and Col-I as well as phosphorylation of Smad2/3 in Tenon's fibroblasts. Altogether, we concluded that EGCG suppressed the myofibroblast transformation in Tenon's fibroblasts through inactivating TGF-ß1/Smad signaling. These findings demonstrate that EGCG can be considered as one of the possible antifibrotic reagents for preventing postoperative scarring in glaucoma filtration surgery.

Silencing of p53 reduces cell migration in human Tenon's fibroblasts induced by TGF-ß.

PURPOSE: Growth factors are considered as key molecules that participating in fibrosis formation. This research aimed to clarify potential effects of p53 on regulation of transforming growth factor ß (TGF-ß) and fibrosis formation and investigate the associated mechanisms. METHODS: Vimentin was examined to identify human Tenon's fibroblasts (HTFs). p53-targeting small interfere RNA (siRNA) was synthesis and transfected into HTFs. Real-time PCR assay was utilized to evaluate p53 and microRNA-29b (miR-29b) expression. Immunocytochemical assay was used to observe TGF-ß expression. The wound healing assay was conducted to evaluate migration of HTFs. Dual-luciferase assay was employed to identify interaction between p53 and miR-29b in HTFs. RESULTS: Vimentin was extensively distributed in HTFs cells. HTFs at density of 5 × 104 cells/ml and 6 days exhibited the best growth. The p53 level in TGF-ß treatment group was significantly higher compared to that in blank group (p < 0.01). miR-29b level in siRNA targeting p53 group was significantly increased compared to that in blank group (p < 0.01). siRNA targeting p53 could significantly inhibit HTFs migration compared to that in single TGF-ß treating HTFs group (p < 0.01). Relative luciferase activity was significantly increased in p53 overexpressed HTFs compared to that in cells transfected with empty pcDNA3.0 plasmid (p < 0.01). CONCLUSIONS: p53 inhibited expression of TGF-ß, suppressed HTFs migration and inhibited HTFs growth, by reducing miR-29b expression and interacting with miR29b gene in HTFs.

Natural Plant Extract Berbamine Is a Potent Inhibitor of Cell Growth and Survival of Human Tenon's Fibroblasts.

INTRODUCTION: Post-trabeculectomy scarring due to excessive proliferation of human Tenon's fibroblasts (HTFs) often led to operation failure. Developing a new anti-fibrosis drug with high efficacy to inhibit HTF cell growth will greatly improve the effectiveness of trabeculectomy. OBJECTIVE: This study aims to investigate the effect of berbamine (BBM) treatment on the cell growth and survival of HTFs. METHODS: Cultured human fetal Tenon's fibroblasts (HFTFs) were treated with or without different concentrations of BBM. Cell morphology was observed with a phase contrast microscope. A CCK-8 method and Ki67 immunofluorescence were used to determine cell viability and cell proliferation. A scratch test was used to study cell migration. Flow cytometry and TUNEL staining were performed to detect cell apoptosis. The expression of BAX/BCL-2, ERK, and AKT/mTOR pathway components was determined by Western blotting. RESULTS: BBM treatment disrupted HFTF normal morphology and inhibited its cell growth in a dose-dependent manner. Ki67 immunofluorescence and scratch assay showed BBM suppressed HFTF cell proliferation and migration. Importantly, BBM dose-dependently increased the BAX/BCL-2 ratio and induced apoptosis in HFTF cells. Western blotting showed BBM significantly inhibited the ERK and AKT/mTOR pathway, and PTEN inhibition ameliorated the inhibitory effect of BBM on cell viability and survival in HFTFs. CONCLUSIONS: BBM potently inhibits the cell growth and survival of HTFs through AKT/mTOR and has the potential to serve as an anti-fibrosis drug after trabeculectomy.

Inhibition of LPA1 Signaling Impedes Conversion of Human Tenon's Fibroblasts into Myofibroblasts Via Suppressing TGF-ß/Smad2/3 Signaling.

Purpose: Lysophosphatidic acid (LPA) is a growth factor-like phospholipid that has been recognized as a profibrotic mediator in numerous tissues, yet, whether it plays a role in subconjunctival fibrosis remains to be investigated. Therefore, this study was designed to examine the effect of LPA1-3 signaling inhibitor, Ki16425 on the conversion of human Tenon's fibroblasts (HTFs) into myofibroblasts. Methods: Primary cultured HTFs were incubated with transforming growth factor-ß1 (TGF-ß1) alone or combined with Ki16425, the cell proliferation and migration were measured by Cell Counting Kit-8 and the scratch wound assay, respectively. HTFs contractility was evaluated with 3-dimensional (3D) Collagen Contraction assay. The mRNA and protein levels of α-smooth muscle actin (α-SMA), Snail and the phosphorylation levels of Smad2/3, p38MAPK, and ERK1/2 were determined by real-time quantitative polymerase chain reaction (RT-qPCR), western blot, and immunofluorescence staining. Results: Ki16425 significantly prevent the proliferation and migration of Tenon's fibroblasts (HTFs) in a dose-dependent manner. Furthermore, Ki16425 blocked HTFs myofibroblast differentiation via downregulation of mRNA and protein expression of α-SMA. 3D collagen gel contraction assay demonstrated that Ki16425 effectively inhibits myofibroblast contraction induced by TGF-ß1. Mechanistically, we revealed that Ki16425 reduces Smad2/3 but not p38MAPK or ERK1/2 phosphorylation by TGF-ß1. By using an LPA1-specific inhibitor, AM095, we confirmed that LPA1 signaling but not LPA2 or LPA3 is involved in TGF-ß1 induced HTFs activation. Conclusions: Our results show that inhibition of LPA1 signaling presents potent antifibrotic effect in HTFs, which may serve as a promising intervention strategy for preventing subconjunctival fibrosis caused by glaucoma filtration surgery.

The Smad2/3/4 complex binds miR-139 promoter to modulate TGFß-induced proliferation and activation of human Tenon's capsule fibroblasts through the Wnt pathway.

The activation and proliferation of human Tenon's fibroblasts (HTFs) play a vital role in the fibrosis in the pathology of the scar formation after the glaucoma filtration surgery. Transforming growth factor ß1 (TGFß1)/Smads signaling has been reported to promote fibrosis. In our previous study, we revealed that TGFß1-induced orbital fibroblast activation and proliferation through Wnt/ß-catenin signaling. As microRNA (miR)-139 could target several factors in Wnt signaling to modulate fibrosis, here, the effect and mechanism of miR-139 in HTF activation and proliferation were investigated. miR-139 overexpression significantly reversed the TGFß1-induced increase in collagen I and α-smooth muscle actin contents and proliferation in HTFs. CTNNB1 and CTNND1 were direct downstream of miR-139 and can significantly restore the suppressive effect of miR-139 on the activation and proliferation in HTFs under TGFß1 stimulation. Smad2/3/4 complex inhibits the transcription activity of miR-139, most possibly by Smad4 binding to the miR-139 promoter. Taken together, we demonstrated a new mechanism of HTF activation and proliferation from the perspective of miRNA regulation, which may provide new strategies for improving the fibrosis after the glaucoma filtration surgery.

MEK inhibition prevents TGF­ß1­induced myofibroblast transdifferentiation in human tenon fibroblasts.

Subconjunctival fibrosis represents the primary cause of postoperative failure of trabeculectomy, and at present there is a lack of effective intervention strategies. The present study aimed to investigate the effect of the mitogen­activated protein kinase kinase (MEK) inhibitor U0126 on human tenon fibroblast (HTF) myofibrosis transdifferentiation, and to illuminate the underlying molecular mechanisms involved. It was demonstrated that U0126 significantly inhibited the proliferation, migration and collagen contraction of HTFs stimulated with TGF­ß1. In addition, U0126 largely attenuated the TGF­ß1­induced conversion of HTFs into myofibroblasts, as indicated by a downregulation of the mRNA and protein expression of α­smooth muscle actin and zinc finger protein SNAI1, and by ameliorating the 3D­collagen contraction response. Mechanistically, U0126 suppressed the TGF­ß1­stimulated phosphorylation of mothers against decapentaplegic homolog 2/3, P38 mitogen­activated protein kinase and extracellular signal­regulated kinase 1/2, indicating that U0126 may inhibit HTF activation through the canonical and non­canonical signaling pathways of TGF­ß1. Therefore, U0126 exhibits a potent anti­fibrotic effect among HTFs, and the inhibition of MEK signaling may serve as an alternative intervention strategy for the treatment of trabeculectomy­associated fibrosis.

TGF-ß1 Induces Human Tenon's Fibroblasts Fibrosis via miR-200b and Its Suppression of PTEN Signaling.

BACKGROUND: To determine the involvement of MicroRNA-200b (miR-200b) in human Tenon's fibroblasts (HTFs) fibrosis. METHODS: HTFs were treated with 10 ng/ml TGF-ß1 for 24 h. Expression of α-smooth muscle actin (α-SMA), Fibronectin and Collagen1A1 (COL1A1) was assessed by western blot and immunofluorescence. MiR-200b was detected by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR), and its potential target genes were validated by luciferase assay. The effects of miR-200b and PTEN (the target gene) on HTFs fibrogenesis were evaluated using miR-200b mimics or inhibitor transfected HTFs, and confirmed with PTEN-specific small interfering RNA (siRNA) and PTEN inhibitor. RESULTS: TGF-ß1 up-regulated miR-200b and promoted the expression of α-SMA, Fibronectin and COL1A1 in HTFs, and the effects could be strengthened or hampered by adding miR-200b mimics or inhibitor, respectively. Luciferase assay identified PTEN as the target gene of miR-200b, and decreased PTEN level due to up-regulation of miR-200b was found to correlate with intensified expression of α-SMA, Fibronectin and COL1A1. Determination of PTEN's role in fibrosis was carried out by adding PTEN specific siRNA or PTEN inhibitor into HTFs, which led to intensified expression of fibrosis-related proteins. CONCLUSION: TGF-ß1-mediated miR-200b induces HTFs fibrosis through suppressing PTEN signaling pathway.

Effects of titanium dioxide nanoparticles on the inhibition of cellular activity in human Tenon's fibroblasts under UVA exposure.

PURPOSE: To investigate the effect of titanium dioxide (TiO2) nanoparticles on the inhibition of the in vitro cellular activity of human Tenon's fibroblasts (HTFs) under UVA exposure. METHODS: The effects of TiO2 nanoparticles on human Tenon's fibroblasts were evaluated after 1, 4, 6, and 24 h of exposure to UVA at levels of 2.5, 5.0, and 10 J/cm2. The methyl thiazolyl tetrazolium (MTT) assay was performed to measure the suppression of cellular metabolic activity. The lactate dehydrogenase (LDH) assay was performed to determine the extent of cell membrane damage. Flow cytometric analysis and inverted phase-contrast and electron microscopy were performed. The scratch wound assay was performed to visualize suppression of cellular migration. RESULTS: MTT assay values were similar between the UVA-exposed groups and the control group without UVA exposure. However, the combined exposure of TiO2 nanoparticles and UVA exposure induced significant dose-dependent inhibition of cellular viability and damage to HTFs, especially at concentrations of TiO2 equal to or greater than 100 µg/mL and 2.5 J/cm2 of UVA irradiation. Changes in cellular morphology increased in a dose-dependent pattern with a TiO2 concentration greater than 100 µg/mL under UVA exposure. At a TiO2 concentration of 150 µg/mL, damage to the cellular morphology of the HTFs was significantly increased, and nanoparticles were seen inside of the cytoplasm in the affected HTFs exposed to UVA. There was a significant reduction of cellular migration at TiO2 concentrations higher than 150 µg/mL. CONCLUSION: TiO2 nanoparticles inhibited the cellular activity of HTFs under UVA irradiation and showed potential for use to prevent the wound scarring of Tenon's fibroblasts. Further studies will be necessary to determine the optimal concentration of TiO2 nanoparticles and UVA exposure dose for clinical applications.

A key role of microRNA-26a in the scar formation after glaucoma filtration surgery.

Glaucoma is one of the leading causes of blind worldwide. Post-operative scar formation of filtering tract was one of the main reasons for failure of glaucoma filtration surgery. In this study, we conducted several experiments to detect the expression of miR-26a in the scar tissue in filtering tract and then detect its potential biological effects as well as its target gene. In our present study, it was found that miR-26a was significantly down-regulated in filtering tract scar. Advanced study on the association between the miR-26a and connective tissue growth factor (CTGF) micro RNA (mRNA) showed that miR-26a was inversely correlated with CTGF mRNA level. Advanced biological studies showed that overexpression of miR-26a could decrease the cell viability and migration ability of human Tenon's fibroblasts (HTFs) fibrosis in vitro model. It was also found that miR-26a might up-regulate the apoptotic level of HTFs. Through protein expression detection and luciferase reporter assay, it was found that miR-26a could produce functions that directly target the CTGF. In conclusion, the key finding of the current study is that miR-26a can suppress the activation of HTFs by transforming growth factor (TGF)-ß by targeting CTGF. This data indicates that miR-26a plays an essential role in the formation of filtering tract scar and function as a potential drug target.