Capsule Fibroblasts Research Articles

Inhibitive effect of TAK-242 on Tenon's capsule fibroblasts proliferation in rat eyes.

To study the inhibition effect of TAK-242 on the proliferation of rat eye Tenon's capsule fibroblasts via the toll-like receptor 4 (TLR4) signaling pathway. SD rat Tenon's capsule fibroblasts were extracted and cultured, then the cells were divided into normal control group, lipopolysaccharide (LPS) group (10 g/mL LPS) and TAK-242 group (1 µmol/L TAK-242, and 10 µg/mL LPS after 30min). The expressions of TLR4, transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6) in each group were detected by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Cell proliferation was detected by cell counting kit-8 (CCK-8). Double immunofluorescent labeling in the extracted cells showed negative keratin staining and positive vimentin staining. Western blot showed that the LPS group had the highest expression of TLR4 and TGF-β1 (P<0.01). Enzyme linked immunosorbent assay (ELISA) also showed that the secretion of IL-6 was the highest in LPS group (P<0.01). But there was no significant difference in TLR4 and TGF-1, as well as IL-6 expressions between the TAK-242 group and the normal control group (P>0.05). RT-PCR showed that the IL-6 mRNA expression in LPS group was the highest in the three groups (P<0.01). TAK-242 inhibits the proliferation of LPS-induced Tenon's capsule fibroblasts and the release of inflammatory factors by regulating the TLR4 signaling pathway, providing a new idea for reducing the scarring of the filter passage after glaucoma filtration surgery.

Sulfasalazine Resolves Joint Stiffness in a Rabbit Model of Arthrofibrosis

Joint stiffness due to fibrosis/capsule contracture is a seriously disabling complication of articular injury that surgical interventions often fail to completely resolve. Fibrosis/contracture is associated with the abnormal persistence of myofibroblasts, which over-produce and contract collagen matrices. We hypothesized that intra-articular therapy with drugs targeting myofibroblast survival (sulfasalazine), or collagen production (β-aminopropionitrile and cis-hydroxyproline), would reduce joint stiffness in a rabbit model of fibrosis/contracture. Drugs were encapsulated in poly[lactic-co-glycolic] acid pellets and implanted in joints after fibrosis/contracture induction. Capsule α-smooth muscle actin (α-SMA) expression and intimal thickness were evaluated by immunohistochemistry and histomorphometry, respectively. Joint stiffness was quantified by flexion-extension testing. Drawer tests were employed to determine if the drugs induced cruciate ligament laxity. Joint capsule fibroblasts were tested in vitro for contractile activity and α-SMA expression. Stiffness in immobilized joints treated with blank pellets (control) was significantly higher than in non-immobilized, untreated joints (normal) (p = 0.0008), and higher than in immobilized joints treated with sulfasalazine (p = 0.0065). None of the drugs caused significant cruciate ligament laxity. Intimal thickness was significantly lower than control in the normal and sulfasalazine-treated groups (p = 0.010 and 0.025, respectively). Contractile activity in the cells from controls was significantly increased versus normal (p = 0.001). Sulfasalazine and β-aminopropionitrile significantly inhibited this effect (p = 0.005 and 0.0006, respectively). α-SMA expression was significantly higher in control versus normal (p = 0.0021) and versus sulfasalazine (p = 0.0007). These findings support the conclusion that sulfasalazine reduced stiffness by clearing myofibroblasts from fibrotic joints. Statement of clinical significance: The results provide proof-of-concept that established joint stiffness can be resolved non-surgically. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:629-638, 2020.

LncRNA NR_003923 promotes cell proliferation, migration, fibrosis, and autophagy via the miR-760/miR-215-3p/IL22RA1 axis in human Tenon\u2019s capsule fibroblasts

Noncoding RNAs (ncRNAs), including long ncRNAs (lncRNA) have manifested an important role in the pathophysiology of many diseases. Glaucoma is a primary cause of irreversible blindness worldwide. However, the involvement of lncRNAs in glaucoma remains largely unknown. Here, we performed the lncRNA expression assay based on clinical tissues and identified a specific functional lncRNA, NR_003923, and investigated its potential role in glaucoma. Knockdown of NR_003923 in human Tenon’s capsule fibroblast cells (HTFs) inhibited TGF-β-induced cell migration, proliferation, fibrosis, and autophagy. The dual luciferase reporter assay confirmed that miR-760 and miR-215-3p interacted with NR_003923. miR-760 and miR-215-3p inhibitor reversed the effects of NR_003923 and TGF-β-induced cell apoptosis. Moreover, the expression of miR-760 and miR-215-3p was decreased in glaucoma comparing with control. Furthermore, through microarray we found IL22RA1 was increased in glaucoma and both of miR-760 and miR-215-3p bound to the 3′ UTR of IL22RA1. Overexpression of IL22RA1 enhanced HTFs migration and proliferation, while miR-760 and miR-215-3p mimics reversed these promotive biological roles induced by IL22RA1. In conclusion, NR_003923 and IL22RA1 might contribute to glaucoma progression and be a novel and potential biomarkers and therapeutic targets for glaucoma.

Transforming Growth Factor-β1–induced Human Subconjunctival Fibrosis is Mediated by MicroRNA 143/145 Expression

To investigate the roles and pathways of microRNAs 143 and 145 in transforming growth factor (TGF)-β1-induced human subconjunctival fibrosis. Human tenon's capsule fibroblasts (HTFs) were obtained from a healthy eye. After treating cultured HTFs with TGF-β1, the expression of microRNAs 143 and 145 was evaluated using polymerase chain reaction. To identify the pathways of TGF-β1-induced microRNA 143/145 expression, HTFs were treated with specific inhibitors of p38MAPK, PI3K/Akt, JNK, ERK, and with siRNAs for SMAD2 and SMAD4. Mutagenesis studies were performed to evaluate the role of the CArG box and SMAD-binding element (SBE). To investigate the role of microRNA 143/145 in TGF-β1-induced myofibroblast transdifferentiation, microRNA 143/145 mimics and microRNA 143/145 inhibitors were applied to the HTFs. Array analysis revealed that TGF-β1 induced the expression of microRNA 143/145 in a dose- and time-dependent manner. When inhibitors and siRNAs for p38MAPK, PI3K/Akt, ERK, and JNK were applied, the TGF-β1-induced expression of microRNA 143/145 was inhibited; however, SMAD2 and SMAD4 inhibition did not affect the TGF-β1-induced expression of these microRNAs. In the mutagenesis studies, both the CArG box and SBE were associated with TGF-β1-induced expression of microRNA 143/145. Mimics of microRNA 143/145 induced increased myofibroblast formation, whereas their inhibitors had the opposite effect. TGF-β1-induced human subconjunctival fibrosis was mediated by the expression of microRNA 143/145, mainly via SMAD-independent pathways. Inhibition of TGF-β1-induced microRNA 143/145 expression in HTFs might represent a novel strategy to prevent subconjunctival fibrosis.

Differential effects of dexamethasone and indomethacin on Tenon's capsule fibroblasts: Implications for glaucoma surgery

Dysregulated wound healing and subsequent fibrosis represents the most common cause of failure in glaucoma filtration surgery. Primary means to prevent this outcome are the anti-metabolite surgical adjuvants, however, topical corticosteroids are commonly used postoperatively to permit further control of wound healing and development of the filtration bleb. Unfortunately, they carry important side effects such as raised intraocular pressure, cataract and increased infection risk. Non-steroidal anti-inflammatory drugs (NSAIDs) show promising results in clinical trials as an alternative wound modulatory drug. NSAIDs exhibit non-inferiority to steroids in terms of post-operative intraocular pressure control and secondary IOP lowering interventions, however there is little known about the differing effects these drugs exert on human Tenon's capsule fibroblast (HTCF) mediated wound healing. The purpose of this study was to assess the individual effects of dexamethasone and indomethacin on the extracellular matrix modifying actions of HTCFs in vitro. To this end, HTCFs were cultured in 3D collagen matrices as well as in 2D monolayers and exposed to clinically relevant concentrations of dexamethasone or indomethacin for up to seven days. HTCF-mediated wound healing functions were assayed through collagen matrix contraction, extracellular matrix morphology, estimation of HCTF proliferation and differentiation into myofibroblasts within the collagen matrices, as well as western blot. Both drugs significantly reduced HTCF-mediated collagen contraction relative to control however there was a significant trend towards greater inhibition with indomethacin exposure compared to dexamethasone. Indomethacin exposure significantly reduced HTCF-mediated collagen remodelling activity compared vehicle control, whereas dexamethasone was unable to reduce remodelling activity at any of the studied exposures. Both drugs reduced myofibroblast differentiation, however indomethacin alone demonstrated an inhibitory effect on final cell number relative to control whereas dexamethasone had no significant effect at any studied exposure. These findings demonstrate that both steroidal and NSAID treatment can mitigate HTCF-mediated collagen contraction and αSMA expression. However, NSAIDs may function to better impede HTCF proliferation and remodelling activity. Taken in the context of previous glaucoma surgical trials, NSAIDs appear to be a viable alternative to steroids for post-operative wound modulation.

The Smad2/3/4 complex binds miR-139 promoter to modulate TGFβ-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 β1 (TGFβ1)/Smads signaling has been reported to promote fibrosis. In our previous study, we revealed that TGFβ1-induced orbital fibroblast activation and proliferation through Wnt/β-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 TGFβ1-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 TGFβ1 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.

Inhibition of hepatocyte growth factor on proliferation and transdifferentiation of human Tenon capsule fibroblasts triggered by transforming growth factor-β1in vitro

Objective To investigate the effects of hepatocyte growth factor (HGF) on proliferation and transdifferentiation of human Tenon capsule fibroblasts induced by transforming growth factor -β1 (TGF-β1) in vitro. Methods Human Tenon capsule fibroblasts were cultured and divided into blank control group, TGF-β1 treated group and different concentrations HGF+ TGF-β1 groups.The TGF-β1 at 10 μg/L was added into culture medium of the TGF-β1 treated group, and different concentrations of HGF (25, 50, 100, 200 μg/L) and 10 μg/L TGF-β1 were added into culture medium of the HGF25 μg/L+ TGF-β1, HGF50 μg/L+ TGF-β1, HGF100 μg/L+ TGF-β1, HGF200 μg/L+ TGF-β1 group respectively, Methyl thiazolyl tetrazolium (MTT) was employed to measure the cell proliferation (absorbance at 560 nm). Immunofluorescence staining was used to evaluate and locate the expression of α-smooth muscle action (α-SMA) in the cells.The expression of α-SMA protein in the cells was detected by Western blot assay. Results Cultured cells showed fusiform in shape with the positive response for vimentin.The proliferation value of the cells was 0.203±0.025, 0.497±0.101, 0.426±0.062, 0.354±0.040, 0.272±0.084, 0.241±0.011 in the blank control group, TGF-β1 treated group, HGF25 μg/L+ TGF-β1 group, HGF50 μg/L+ TGF-β1 group, HGF100 μg/L+ TGF-β1 group and HGF200 μg/L+ TGF-β1 group, respectively, showing a significant difference among the groups (F=9.210, P=0.003). Compared with the TGF-β1 treated group, the proliferation values of the cells were significantly reduced in the blank control group and HGF+ TGF-β1 group (all at P<0.05). Immunofluorescence staining showed that α-SMA protein mainly located in cytoplasm with the strong red fluorescence in the cells of the TGF-β1 treated group and weak red fluorescence in HGF+ TGF-β1 group, and the expression of α-SMA was absent in the blank control group.The percentage of α-SMA-positive cells was (60.0±4.7)% in the TGF-β1 treated group and (14.3±3.1)% in the HGF+ TGF-β1 group, with significant difference between the two groups (t=19.856, P<0.001). The relative expression levels of the α-SMA protein in the cells were 0.642±0.032, 1.330±0.069 and 0.884±0.040 in the blank control group, TGF-β1 group and HGF100 μg/L+ TGF-β1 group, respectively, showing a significant difference among the groups (F=13.370, P<0.001), and relative expression levels of the α-SMA protein in the cells were significantly lower in the blank control group and HGF100 μg/L+ TGF-β1 group than that in the TGF-β1 treated group (all at P<0.05). Conclusions HGF can inhibit the proliferation of human Tenon capsule fibroblasts, down-regulate the expression of α-SMA protein induced by TGF-β1 and arrest the phenotype transformation of fibroblasts in vitro. Key words: Tenon capsule/cytology; Fibroblasts/metabolism; Hepatocyte growth factor/administration & dosage; Transforming growth factor beta type 1; Fibrosis/prevention & control; α-Smooth muscular actin; Humans; Cells, cultured

Effect of Lignocaine Concentration on Human Fibroblasts Growth in Eyes Undergoing Trabeculectomy: An in vitro Study

Purpose: To evaluate the effect of lignocaine on growth and apoptosis indication of primary human Tenon’s capsule fibroblast (HTFs) in an in vitro model. Patients and Methods: Tenon’s capsule tissue obtained from patients undergoing trabeculectomy were grown in cell culture medium. The effect of different concentrations of lignocaine (0.5, 1.0, 1.5, and 2%) on the morphology and growth of the fibroblasts was studied using microscopy, cell viability, and proliferation assay, and apoptosis was detected using the FITC Annexin V Apoptosis Kit. Results: Morphological changes similar to those of apoptotic cells, including cytoplasmic vacuolation, shrinkage, and rounding were visualized in the cells treated with concentrations greater than 1.0% (i.e., 1.5, 2.0%). Though proliferation inhibition was found with all four concentrations (0.5–2.0%), the viability of cells decreased from 1.0% lignocaine. Conclusion: 0.5% lignocaine prevents proliferation of fibroblasts without causing apoptosis in vitro.

TGF-β2 induces proliferation and inhibits apoptosis of human Tenon capsule fibroblast by miR-26 and its targeting of CTGF

AimThe aim of this study was to research the effect of TGF-β2 on human enon capsule fibroblasts proliferation and apoptosis and its potential mechanism. MethodsHuman eyeball fascia tissues (n = 45) were derived from ocular fascia tissues of patients who were underwent glaucoma filtration surgery, and Tenon capsule fibroblasts were obtained from these tissues. Liposome-mediated transfection, CCK8 assay, Hoechst33258 staining, qRT-PCR detection, western blot, and luciferase reporter assay were performed. ResultsTGF-β2 promoted proliferation and inhibited apoptosis of human Tenon capsule fibroblasts in a dose-dependent manner. TGF-β2 induced down-regulation of miR-26 and up-regulation of CTGF in a dose-dependent manner. CTGF was the target gene of miR-26 and miR-26 had a negative regulatory effect on CTGF expression. miR-26 up-regulation could significantly decrease proliferation and increase apoptosis of human Tenon capsule fibroblasts after induced by TGF-β2 (P < 0.05). Down-regulation of CTGF could markly decrease proliferation and increase apoptosis of human Tenon capsule fibroblasts after induced by TGF-β2 (P < 0.05). ConclusionmiR-26 could inhibit proliferation and promote apoptosis of human Tenon capsule fibroblasts after they were induced by TGF-β2 through suppressing CTGF expression.

Tacrolimus inhibits proliferation and induces apoptosis by decreasing survivin in scar fibroblasts after glaucoma surgery.

To investigate the effect of tacrolimus on the proliferation of fibroblasts after glaucoma surgery. Biopsy was applied in this study. Under aseptic conditions, tissues were collected from rabbits, cut into small pieces and cultured. Morphology of fibroblasts was observed under a microscope. Features of fibroblasts were identified via immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Western blotting and RT-PCR were performed to detect the expressions of related proteins after treatment. Flow cytometry and cell counting kit-8 (CCK-8) assay were employed to examine the proliferation of human Tenon's capsule fibroblasts (HTFs) after tacrolimus treatment. Tacrolimus decreased the levels of survivin and α-smooth muscle actin (α-SMA) after transforming growth factor-β (TGF-β) treatment. Besides, it inhibited proliferation and induced apoptosis of HTFs. Tacrolimus reduces proliferation and promotes apoptosis of HTFs by inhibiting the expression of survivin, which may be a strategy for treating hypertrophic scar after glaucoma surgery.

Is Autophagy Dysfunction a Key to Exfoliation Glaucoma?

In this short report we review previous work toward the identification of the protein and cellular sources of exfoliation glaucoma and described our recent finding on dysfunction of autophagy in Tenon capsule fibroblasts obtained from exfoliation syndrome glaucoma patients at the time of surgery and discuss the potential implications of these findings for understanding the cellular sources of the disease.

Induction of pluripotent stem cells by reprogramming human ocular fibroblasts under xeno-free conditions

To develop an efficient and xeno-free standard eye-derived induced pluripotent stem cell reprogramming protocol for use during induced pluripotent stem cell-based cell therapies in treating retinal degenerative diseases and to compare the relative effectiveness of both animal- and non-animal-derived culture systems in the generation of induced pluripotent stem cells. Primary cultured human pterygium fibroblasts and human Tenon's capsule fibroblasts were induced to induced pluripotent stem cells using a non-in-tegrated virus under two xeno-free systems; as part of this study, a traditional non-xeno-free reprogramming system was also assessed. Induced pluripotent stem cell clones were selected and counted by live staining. Reprogramming efficiencies were evaluated between the fibroblasts and among different culture systems. In a series of experiments, such as PCR and immunofluorescence staining, the induced pluripotent stem cells were characterized. Human pterygium fibroblast- and human Tenon's capsule fibroblast-derived induced pluripotent stem cells were successfully established using different reprogramming systems, under which they exhibited properties of induced pluripotent stem cells. Reprogramming efficiencies of induced pluripotent stem cells using the cell therapy system, the traditional system, and the E6/E8 system were 0.014%, 0.028%, and 0.001%, respectively, and those of human pterygium fibroblast- and human Tenon's capsule fibroblast-derived induced pluripotent stem cells-using the aforementioned systems-were 0.018% and 0.017%, respectively. Sendai virus facilitates induced pluripotent stem cell reprogramming of ocular fibroblasts-both human pterygium and human Tenon's capsule fibroblasts being safe and efficient for induced pluripotent stem cell reprogramming. Although the reprogramming efficiencies of ocular-derived induced pluripotent stem cells under xeno-free conditions were not superior to those observed using the traditional reprogramming system, the cell therapy system reprogramming system is a good option when induced pluripotent stem cells are to be induced under xeno-free conditions.

Effects of Valproic Acid on the Survival of Human Tennon's Capsule Fibroblasts

Effects of Valproic Acid on the Survival of Human Tennon's Capsule Fibroblasts

The Anti-fibrotic Effect of Nilotinib on Tenon's Capsule Fibroblastsin Vitro

The Anti-fibrotic Effect of Nilotinib on Tenon's Capsule Fibroblasts<i>in Vitro</i>

Involvement of Rho-associated coiled-coil kinase signaling inhibition in TGF-β1/Smad2, 3 signal transduction in vitro.

To research the effect of Y-27632, a selective Rho-associated coiled-coil kinase (ROCK) inhibitor, on TGF-β1/Smad2, 3 signal transduction in ocular Tenon's capsule fibroblasts (OTFs). Primary ocular Tenon's capsule fibroblasts had been cultured in vitro. The effect of Y27632 on proliferation of OTF stimulated by lysophosphatidic acid (LPA) was evaluated by MTT colorimetric assay so as to sift out the proper concentrations range of Y-27632 for the next experiment. Real time-polymerase chain reactor (RT-PCR) was to analyze the changes of Smad2 and Smad3 genes of cells affected by Y-27632, though unaffected by transforming growth factor-beta1 (TGF-β1). Proteins of Smad2, Smad3, phosphorylated Smad2 (Ser245/250/255), and phosphorylated Smad3 (Ser423/425/203) were respectively quantified by Western blot after OTFs were successively incubated by TGF-β1 and Y-27632. Meanwhile, α-smooth muscular actin (α-SMA) protein was also quantified after the small intervening gene fragments of human Smad2 and Smad3 were designed, synthesized, and then transfected to OTFs. Y-27632 significantly inhibited OTFs proliferation stimulated by LPA. Also Y-27632 significantly suppressed the expressions of Smad2 mRNA, Smad2, 3 proteins expressions, Smad3 phosphorylation at the carboxylic terminals of Ser423/425/203 which had been radically promoted by TGF-β1. SiRNA-Smad2, 3 suppressed α-SMA expressions, but less effectively than Y-27632. The inhibition of ROCK signaling may be a potential therapeutic candidate for the treatment of the filtration channel fibrosis.

Posttranscriptional Regulation of LOXL1 Expression Via Alternative Splicing and Nonsense-Mediated mRNA Decay as an Adaptive Stress Response.

Alternative mRNA splicing coupled to nonsense-mediated decay (NMD) is a common mRNA surveillance pathway also known to dynamically modulate gene expression in response to cellular stress. Here, we investigated the involvement of this pathway in the regulation of lysyl oxidase-like 1 (LOXL1) expression in response to pseudoexfoliation (PEX)-associated pathophysiologic factors. Transcript levels of LOXL1 isoforms were determined in ocular tissues obtained from donor eyes without and with PEX syndrome. Pseudoexfoliation-relevant cell types, including human Tenon's capsule fibroblasts (hTCF) and trabecular meshwork cells (hTMC), were exposed to puromycin, caffeine, TGF-β1, homocysteine, IL-6, retinoic acid, UV-B radiation, oxidative stress, and mechanical stress for up to 48 hours. Western blot analysis was carried out using antibodies against LOXL1, (phosphorylated-) eukaryotic initiation factor 2-α (eIF2-α), and regulator of nonsense transcripts 2 (UPF2). RNA interference was used to knockdown UPF1-3 and Serine/threonine-protein kinase (SMG1). Constitutive expression of wild-type LOXL1 and alternatively spliced LOXL1-a transcripts was detected in all ocular tissues showing highest levels in trabecular meshwork and differential expression between PEX and control specimens. LOXL1-a transcripts were upregulated in hTCF and hTMC by NMD inhibitors puromycin and caffeine (≥6-fold; P < 0.01) or after knockdown of NMD core factors (≥2-fold; P < 0.05), whereas mRNA and protein levels of LOXL1 were reduced (≤0.8 fold; P < 0.05). Exposure of cells to various PEX-associated (stress) factors, including TGF-β1, UV-B light, oxidative stress, mechanical stress, and retinoic acid enhanced LOXL1-a transcript levels (≥1.5-fold; P < 0.05), while partially downregulating LOXL1 levels (≤0.7-fold; P < 0.05). Stress-induced inhibition of NMD was dependent on phosphorylation of eIF2α. These findings provide evidence for a functional role of alternative splicing coupled to NMD in the posttranscriptional regulation of LOXL1 gene expression and suggest this mechanism to represent a dynamic mode of adapting LOXL1 expression to PEX-associated environmental and nutritional cues.

Antiproliferative effect of double suicide gene delivery mediated by polyamidoamine dendrimers in human Tenon's capsule fibroblasts.

The aim of the present study was to investigate the therapeutic potential of a double suicide gene, thymidine kinase (TK) combined with cytosine deaminase (CD), mediated by generation of 5-polyamidoamine dendrimers (G5-PAMAM-D) on human Tenon's capsule fibroblasts (HTFs) as an anti-scarring agent. The pAcGFP1-Hyg-TK-CD plasmid was transfected into HTFs, and reverse-transcription polymerase chain reaction (RT-PCR) was used to detect TK-CD expression. MTT cell proliferation assay was used to evaluate the cytotoxic effects of ganciclovir (GCV) and 5-flurocytosine (5-FC) on HTFs. The optimal concentration of GCV and 5-FC in TK-CD transfected HTFs (HTF-TK-CD) was selected by accessing the lowest and highest cytotoxicity caused, respectively. The morphological changes of transfected HTFs following treatment with GCV and 5-FC were observed by light and transmission electron microscopy. Results demonstrated that the double suicide gene TK-CD mediated by the G5-PAMAM-D delivery system was successfully expressed in HTFs as determined by RT-PCR. A concentration of 3 µg/ml GCV and 200 µg/ml 5-FC was identified as optimal for these prodrugs. The growth rate and number of HTF-TK-CD cells decreased following treatment with GCV and 5-FC as revealed by light microscopy. Additionally, the prodrugs GCV and 5-FC not only demonstrated toxicity on transfected HTFs but also exerted a ‘bystander effect’. The present study illustrated that the double suicide gene TK-CD delivery mediated by G5-PAMAM-D was effective in reducing HTF proliferation and inducing cell apoptosis. Furthermore, TK-CD delivery mediated by G5-PAMAM-D may be used as an anti-scarring agent and provide a therapeutic potential for patients requiring glaucoma filtration surgery.

5-Aza-2′-deoxycytidine induces human Tenon's capsule fibroblasts differentiation and fibrosis by up-regulating TGF-β type I receptor

The principle reason of high failure rate of glaucoma filtration surgery is the loss of filtration function caused by postoperative scar formation. We investigated the effects of 5-aza-2′-deoxycytidine (5-Aza-dc), a DNA methyltransferases inhibitor, on human Tenon's capsule fibroblasts (HTFs) differentiation and fibrosis and its mechanism of action, especially in relation to transforming growth factor (TGF)-β1 signaling. TGF-β1 was used to induce differentiation of cultured HTFs. 5-Aza-dc suppressed DNA methyltransferases (DNMTs) activity 6 h after treatment with a course corresponding to that of TGF-β1-induced reduction of DNMT activity without affecting cell viability as measured by Cell Counting Kit-8 assay. 5-Aza-dc also reduced DNMT1 and DNMT3a protein expression from 24 to 48 h. HTFs migration evaluated by scratch-wound assay were significantly increased 24 h after 5-Aza-dc treatment, a time course similar to that of TGF-β1. Treatment with 5-Aza-dc significantly increased the mRNA and protein levels of α-smooth muscle actin (α-SMA), collagen-1A1 (Col1A1), fibronectin (FN) and TGF-β type I receptor (TGFβRI). Furthermore, the effects of 5-Aza-dc on DNMT activity suppression, cell migration, and fibrosis were all reversed by a TGFβRI inhibitor- SB-431542. Meanwhile, knockdown of DNMT1 upregulated TGFβRI expression and had the same fibrosis-inducing effect in HTFs, which was also inhibited by SB-431542. Thus, the results indicate that DNA hypomethylation induces HTFs differentiation and fibrosis through up-regulation of TGFβRI. DNA methylation status plays an important role in subconjunctival wound healing.

Anti-scarring effects of butaprost on human subconjunctival Tenon's fibroblasts.

To investigate the toxicity of the E-prostanoid 2 (EP2) receptor agonist, butaprost against human subconjunctival (Tenon's capsule) fibroblasts, and to determine the underlying mechanism. We isolated Tenon's fibroblasts from the subconjunctival area of healthy subjects and evaluated the types of EP receptors expressed using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The toxicity of butaprost against the fibroblasts was evaluated using methyl thiazolyl tetrazolium and lactic dehydrogenase assays. The inhibition of conjunctival fibroblast proliferation by butaprost was assessed by measuring α-actin levels. The underlying mechanism was assessed by measuring intracellular cyclic adenosine monophosphate (cAMP) levels. Intergroup differences were statistically analyzed using an independent t-test. Densitometry of the Western blot bands was performed using the Image J software. Quantitative real-time RT-PCR revealed that the fibroblast EP2 receptor levels were higher than those of the other EP receptors. Butaprost did not show toxicity against Tenon's tissue, but inhibited conjunctival fibroblast proliferation by reducing collagen synthesis. EP2 receptor activation enhanced the cAMP cascade, which might be an important mechanism underlying this effect. Butaprost effectively reduces the subconjunctival scarring response. Given the significance of wound healing modulation in blebs, butaprost's inhibitory effect on subconjunctival Tenon's fibroblasts may be beneficial in managing postoperative scarring in glaucoma surgery.

Overexpression of ALK5 Induces Human Tenon’s Capsule Fibroblasts Transdifferentiation and Fibrosis In Vitro

ABSTRACTPurpose: To investigate the involvement of activin receptor-like kinase 5 (ALK5) in human Tenon’s capsule fibroblasts (HTFs) transdifferentiation and fibrosis.Methods: (1) Cultured HTFs were treated with transforming growth factor beta 1 (TGF-β1) at different concentrations for different durations, mRNA expression of ALK5 and plasminogen activator inhibitor-1 (PAI-1) was measured by quantitative polymerase chain reaction (PCR) while protein expression of ALK5, α-smooth muscle actin (α-SMA), and extracellular matrix deposition including fibronectin (FN) and collagen I (Col1) was assessed by western blot. HTFs with or without TGF-β1 were also treated with an ALK5 activity inhibitor, SB-431542, and fibrosis-related genes were assessed.(2) HTFs were transduced with ALK5 lentivirus (ALK5-OE group) or empty lentivirus (NC-OE) with or without the treatment of SB-431542. Protein expression of ALK5, α-SMA, FN, and Col1 was evaluated.(3) HTFs in the ALK5-OE group and NC-OE group were subjected to a scratch-wound assay and their migratory activities assessed.Results: (1) TGF-β1, in a concentration-dependent manner, upregulated ALK5 and PAI-1 expressions in the HTFs, which peaked between 24 and 36 h. These changes were associated with increases in protein levels of FN, Col1, and α-SMA. These TGF-β1 effects were blocked by the ALK5 inhibitor SB-431542.(2) Similarly, overexpression of ALK5 by lentiviral vector significantly increased protein expression of α-SMA, FN, and Col1. Addition of TGF-β1 to the ALK5-OE cells did not produce additional expression of any of the marker proteins. The upregulation of extracellular matrix and α-SMA can be reduced by SB-431542.(3) In ALK5-OE group, HTFs migration was significantly increased compared with normal control and TGF-β1 could still promote ALK5-OE cells migration.Conclusions: Our findings suggest that ALK5 is an important mediator of HTFs fibrosis. ALK5 is a potential therapeutic target to suppress scar formation after filtration surgery.