Browsing by Subject "Transforming Growth Factor beta2 / pharmacology"
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Item BMP and Activin Membrane Bound Inhibitor Regulates the Extracellular Matrix in the Trabecular Meshwork(ARVO Journals, 2018-04) Hernandez, Humberto; Millar, J. Cameron; Curry, Stacy M.; Clark, Abbot F.; McDowell, Colleen M.Purpose: The trabecular meshwork (TM) has an important role in the regulation of aqueous humor outflow and IOP. Regulation of the extracellular matrix (ECM) by TGFbeta2 has been studied extensively. Bone morphogenetic protein (BMP) and activin membrane-bound inhibitor (BAMBI) has been shown to inhibit or modulate TGFbeta2 signaling. We investigate the role of TGFbeta2 and BAMBI in the regulation of TM ECM and ocular hypertension. Methods: Mouse TM (MTM) cells were isolated from B6;129S1-Bambitm1Jian/J flox mice, characterized for TGFbeta2 and dexamethasone (DEX)-induced expression of fibronectin, collagen-1, collagen-4, laminin, alpha-smooth muscle actin, cross-linked actin networks (CLANs) formation, and DEX-induced myocilin (MYOC) expression. MTM cells were transduced with Ad5.GFP to identify transduction efficiency. MTM cells and mouse eyes were transduced with Ad5.Null, Ad5.Cre, Ad5.TGFbeta2, or Ad5.TGFbeta2 + Ad5.Cre to evaluate the effect on ECM production, IOP, and outflow facility. Results: MTM cells express TM markers and respond to DEX and TGFbeta2. Ad5.GFP at 100 MOI had the highest transduction efficiency. Bambi knockdown by Ad5.Cre and Ad5.TGFbeta2 increased fibronectin, collagen-1, and collagen-4 in TM cells in culture and tissue. Ad5.Cre, Ad5.TGFbeta2, and Ad5.TGFbeta2 + Ad5.Cre each significantly induced ocular hypertension and lowered aqueous humor outflow facility in transduced eyes. Conclusions: We show for the first time to our knowledge that knockdown of Bambi alters ECM expression in cultured cells and mouse TM, reduces outflow facility, and causes ocular hypertension. These data provide a novel insight into the development of glaucomatous TM damage and identify BAMBI as an important regulator of TM ECM and ocular hypertension.Item ID1 and ID3 are Negative Regulators of TGFbeta2-Induced Ocular Hypertension and Compromised Aqueous Humor Outflow Facility in Mice(ARVO Journals, 2021-05-03) Mody, Avani A.; Millar, J. Cameron; Clark, Abbot F.Purpose: In POAG, elevated IOP remains the major risk factor in irreversible vision loss. Increased TGFbeta2 expression in POAG aqueous humor and in the trabecular meshwork (TM) amplifies extracellular matrix (ECM) deposition and reduces ECM turnover in the TM, leading to a decreased aqueous humor (AH) outflow facility and increased IOP. Inhibitor of DNA binding proteins (ID1 and ID3) inhibit TGFbeta2-induced fibronectin and PAI-1 production in TM cells. We examined the effects of ID1 and ID3 gene expression on TGFbeta2-induced ocular hypertension and decreased AH outflow facility in living mouse eyes. Methods: IOP and AH outflow facility changes were determined using a mouse model of Ad5-hTGFbeta2C226S/C288S-induced ocular hypertension. The physiological function of ID1 and ID3 genes were evaluated using Ad5 viral vectors to enhance or knockdown ID1/ID3 gene expression in the TM of BALB/cJ mice. IOP was measured in conscious mice using a Tonolab impact tonometer. AH outflow facilities were determined by constant flow infusion in live mice. Results: Over-expressing ID1 and ID3 significantly blocked TGFbeta2-induced ocular hypertension (P < 0.0001). Although AH outflow facility was significantly decreased in TGFbeta2-transduced eyes (P < 0.04), normal outflow facility was preserved in eyes injected concurrently with ID1 or ID3 along with TGFbeta2. Knockdown of ID1 or ID3 expression exacerbated TGFbeta2-induced ocular hypertension. Conclusions: Increased expression of ID1 and ID3 suppressed both TGFbeta2-elevated IOP and decreased AH outflow facility. ID1 and/or ID3 proteins thus may show promise as future candidates as IOP-lowering targets in POAG.Item Mirna Expression in Glaucomatous and TGFbeta2 Treated Lamina Cribrosa Cells(MDPI, 2021-06-08) Lopez, Navita N.; Rangan, Rajiv; Clark, Abbot F.; Tovar-Vidales, TaraGlaucoma is a group of optic neuropathies that leads to irreversible vision loss. The optic nerve head (ONH) is the site of initial optic nerve damage in glaucoma. ONH-derived lamina cribrosa (LC) cells synthesize extracellular matrix (ECM) proteins; however, these cells are adversely affected in glaucoma and cause detrimental changes to the ONH. LC cells respond to mechanical strain by increasing the profibrotic cytokine transforming growth factor-beta 2 (TGFbeta2) and ECM proteins. Moreover, microRNAs (miRNAs or miR) regulate ECM gene expression in different fibrotic diseases, including glaucoma. A delicate homeostatic balance between profibrotic and anti-fibrotic miRNAs may contribute to the remodeling of ONH. This study aimed to determine whether modulation of miRNAs alters the expression of ECM in human LC cells. Primary human normal and glaucoma LC cells were grown to confluency and treated with or without TGFbeta2 for 24 h. Differences in expression of miRNAs were analyzed using miRNA qPCR arrays. miRNA PCR arrays showed that the miR-29 family was significantly decreased in glaucomatous LC cell strains compared to age-matched controls. TGFbeta2 treatment downregulated the expression of multiple miRNAs, including miR-29c-3p, compared to controls in LC cells. LC cells transfected with miR-29c-3p mimics or inhibitors modulated collagen expression.Item TGFbeta2 Induces the Formation of Cross-Linked Actin Networks (CLANs) in Human Trabecular Meshwork Cells Through the Smad and Non-Smad Dependent Pathways(ARVO Journals, 2017-02) Montecchi-Palmer, Michela; Bermudez, Jaclyn Y.; Webber, Hannah C.; Patel, Gaurang C.; Clark, Abbot F.; Mao, WeimingPurpose: Increased intraocular pressure results from increased aqueous humor (AH) outflow resistance at the trabecular meshwork (TM) due to pathologic changes including the formation of cross-linked actin networks (CLANs). Transforming growth factor beta2 (TGFbeta2) is elevated in the AH and TM of primary open angle glaucoma (POAG) patients and induces POAG-associated TM changes, including CLANs. We determined the role of individual TGFbeta2 signaling pathways in CLAN formation. Methods: Cultured nonglaucomatous human TM (NTM) cells were treated with control or TGFbeta2, with or without the inhibitors of TGFbeta receptor, Smad3, c-Jun N-terminal kinases (JNK), extracellular signal regulated kinase (ERK), P38, or Rho-associated protein kinase (ROCK). NTM cells were cotreated with TGFbeta2 plus inhibitors for 10 days or pretreated with TGFbeta2 for 10 days followed by 1-hour inhibitor treatment. NTM cells were immunostained with phalloidin-Alexa-488 and 4',6-diamidino-2-phenylindole (DAPI). Data were analyzed using 1-way ANOVA and Dunnett's post hoc test. Results: TGFbeta2 significantly induced CLAN formation (n = 6 to 12, P < 0.05), which was completely inhibited by TGFbeta receptor, Smad3, and ERK inhibitors, as well as completely or partially inhibited by JNK, P38, and ROCK inhibitors, depending on cell strains. One-hour exposure to ROCK inhibitor completely resolved formed CLANs (P < 0.05), whereas TGFbeta receptor, Smad3 inhibitor, and ERK inhibitors resulted in partial or complete resolution. The JNK and P38 inhibitors showed partial or no resolution. Among these inhibitors, the ROCK inhibitor was the most disruptive to the actin stress fibers, whereas ERK inhibition showed the least disruption. Conclusions: TGFbeta2-induced CLANs in NTM cells were prevented and resolved using various pathway inhibitors. Apart from CLAN inhibition, some of these inhibitors also had different effects on actin stress fibers.