Chromatin topology dynamics of dexamethasone-treated trabecular meshwork identifies 78 causal genes for intraocular pressure and primary open angle glaucoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE301525 | GEO | 2026/04/10
REPOSITORIES: GEO
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Project description:The physiology of trabecular meshwork (TM) controls aqueous humor outflow resistance and thereby intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma (POAG). To decipher how GWAS-identified non-coding variants contribute to IOP and POAG, we generated a high-resolution map of genome topology and regulatory modules from primary human TM cell lines. Integrated analyses with dexamethasone-treated TM cells, a model of augmented IOP, demonstrate extensive changes in chromatin compartments, accessibility, looping, and histone marks that are highly concordant with transcriptional changes. By combining GWAS-associated variants with dexamethasone-induced chromatin looping, we discovered 26 IOP- and 52 POAG- candidate causal genes, belonging to key TM pathways, including integrin, transcriptional regulation of VENTX, and TNF signaling. Our studies provide a mechanistic framework for elucidating genetic complexity of IOP and pathogenesis of POAG and suggest new targets for therapies.
2026-04-10 | GSE301522 | GEO
Project description:The physiology of trabecular meshwork (TM) controls aqueous humor outflow resistance and thereby intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma (POAG). To decipher how GWAS-identified non-coding variants contribute to IOP and POAG, we generated a high-resolution map of genome topology and regulatory modules from primary human TM cell lines. Integrated analyses with dexamethasone-treated TM cells, a model of augmented IOP, demonstrate extensive changes in chromatin compartments, accessibility, looping, and histone marks that are highly concordant with transcriptional changes. By combining GWAS-associated variants with dexamethasone-induced chromatin looping, we discovered 26 IOP- and 52 POAG- candidate causal genes, belonging to key TM pathways, including integrin, transcriptional regulation of VENTX, and TNF signaling. Our studies provide a mechanistic framework for elucidating genetic complexity of IOP and pathogenesis of POAG and suggest new targets for therapies.
2026-04-10 | GSE301516 | GEO
Project description:The physiology of trabecular meshwork (TM) controls aqueous humor outflow resistance and thereby intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma (POAG). To decipher how GWAS-identified non-coding variants contribute to IOP and POAG, we generated a high-resolution map of genome topology and regulatory modules from primary human TM cell lines. Integrated analyses with dexamethasone-treated TM cells, a model of augmented IOP, demonstrate extensive changes in chromatin compartments, accessibility, looping, and histone marks that are highly concordant with transcriptional changes. By combining GWAS-associated variants with dexamethasone-induced chromatin looping, we discovered 26 IOP- and 52 POAG- candidate causal genes, belonging to key TM pathways, including integrin, transcriptional regulation of VENTX, and TNF signaling. Our studies provide a mechanistic framework for elucidating genetic complexity of IOP and pathogenesis of POAG and suggest new targets for therapies.
2026-04-10 | GSE301519 | GEO
Project description:The physiology of trabecular meshwork (TM) controls aqueous humor outflow resistance and thereby intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma (POAG). To decipher how GWAS-identified non-coding variants contribute to IOP and POAG, we generated a high-resolution map of genome topology and regulatory modules from primary human TM cell lines. Integrated analyses with dexamethasone-treated TM cells, a model of augmented IOP, demonstrate extensive changes in chromatin compartments, accessibility, looping, and histone marks that are highly concordant with transcriptional changes. By combining GWAS-associated variants with dexamethasone-induced chromatin looping, we discovered 26 IOP- and 52 POAG- candidate causal genes, belonging to key TM pathways, including integrin, transcriptional regulation of VENTX, and TNF signaling. Our studies provide a mechanistic framework for elucidating genetic complexity of IOP and pathogenesis of POAG and suggest new targets for therapies.
2026-04-10 | GSE301517 | GEO
Project description:The physiology of trabecular meshwork (TM) controls aqueous humor outflow resistance and thereby intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma (POAG). To decipher how GWAS-identified non-coding variants contribute to IOP and POAG, we generated a high-resolution map of genome topology and regulatory modules from primary human TM cell lines. Integrated analyses with dexamethasone-treated TM cells, a model of augmented IOP, demonstrate extensive changes in chromatin compartments, accessibility, looping, and histone marks that are highly concordant with transcriptional changes. By combining GWAS-associated variants with dexamethasone-induced chromatin looping, we discovered 26 IOP- and 52 POAG- candidate causal genes, belonging to key TM pathways, including integrin, transcriptional regulation of VENTX, and TNF signaling. Our studies provide a mechanistic framework for elucidating genetic complexity of IOP and pathogenesis of POAG and suggest new targets for therapies.
2026-04-10 | GSE301512 | GEO
Project description:To identify the specific genes in human trabecular meshwork (TM) related to POAG.Primary open-angle glaucoma TM specimens were obtained from routine trabeculectomy surgery. Nonglaucomatous control TM specimens were dissected from donor eyes using the same approach as a standard trabeculectomy. All cases were screened for myocilin (MYOC) mutations. Total RNA was extracted, labeled, and hybridized to Illumina HumanWG-6 BeadChips. Expression data were normalized and analyzed using the R package limma in Bioconductor. Pathway analyses were performed using DAVID Bioinformatics Resources.Our study included surgical TM specimens from 15 cases and 13 controls. One case was identified with a heterozygous Q368X MYOC mutation. If TMs were available from both eyes in an individual, the expression data were combined for analysis. The following three comparisons were performed for differential analyses: (1) MYOC POAG case versus 14 non-MYOC POAG cases, (2) MYOC POAG case versus 13 controls, and (3) 14 non-MYOC POAG cases versus 13 controls. Limited by one MYOC case in comparisons 1 and 2, expression changes were reported comparing the fold changes but without P values. Comparison 3 identified 483 genes, including 36 components of TM exosomes. Gene ontology analysis identified several enriched functional clusters, including cell adhesion, extracellular matrix, and secretion.This is the largest TM expression study of POAG cases and controls performed to date and represents the first report of TM expression in a patient having POAG with a Q368X MYOC mutation. Our data suggest the potential role of endocytic and exosome pathways in the pathogenesis of POAG.
| S-EPMC3787658 | biostudies-literature
Project description:We previously identified and characterized human trabecular meshwork stem cells (TMSCs) based on high expression of ABCG2/p75 positivity and high nucleus to cytoplasmic ratio. These TMSCs expressing high ABCG2 and p75 were located to the insert region of the human TM. Additionally, we demonstrated an age-related reduction in the TMSC content which was significantly associated with TM cell loss. In continuation, this study was aimed to determine the TMSC content in glaucomatous donor eyes wherein a drastic reduction in TM cellularity has already been reported. Anterior segments from known glaucomatous (n = 6) and age-matched normal (n = 8) donors were dissected into four quadrants. A minimum of three sections from each quadrant were used for histopathological analysis as well as immunostaining. Analysis of hematoxylin and eosin-stained sections from glaucomatous tissues revealed a decrease in total TM cellularity, thickening of trabecular beams, fusion of trabeculae, absence of patent Schlemm's canal compared to age-matched controls. In addition, the TM thickness at various positions of the meshwork and the coronal as well as the meridional diameters of the Schlemm's canal were observed to be significantly reduced in glaucomatous eyes. Further, sections from both the groups were immunostained for universal stem cell marker ABCG2 and neural crest derived stem cell marker p75. The images were acquired using Leica SP8 confocal microscope. Quantification of total TM cellularity based on nuclear counterstain (mean ± SD) using ImageJ identified 69.33 ± 12.77 cells/section in control eyes. In glaucomatous donors, the TM cellularity was found to be reduced significantly to 41.83 ± 9.0 (p = 0.0007). In addition, a reduction in the percentage of TMSCs (cells with high ABCG2 expression and p75 positivity) was evident in glaucomatous donors (0.14 ± 0.17%) compared to age-matched controls (4.73 ± 5.46%) (p = 0.064). Thus, the present study confirmed the significant decline in TM cellularity and a reducing trend in the TMSC content, though this reduction was non-significant in glaucomatous donor eyes. Further studies are essential to elucidate the role of TMSCs in the pathogenesis of primary open angle glaucoma.
| S-EPMC8720087 | biostudies-literature
Project description:The receptor-associated prorenin system (RAPS) is associated with several pathologic conditions, including diabetic retinopathy, age-related macular degeneration, and uveitis. Here, we show the involvement of RAPS in the trabecular meshwork (TM) from patients with primary open-angle glaucoma (POAG) and neovascular glaucoma (NVG) due to proliferative diabetic retinopathy. Anterior chamber (AC) levels of prorenin significantly increased in both POAG and NVG, as did those of angiotensin II in NVG alone, compared to cataract. In surgically excised TM tissues, (pro)renin receptor ((P)RR) and angiotensin II type 1 receptor (AT1R) co-localized with prorenin and angiotensinogen, respectively. In screening for various genes related to glaucoma, prorenin stimulation to human TM cells exclusively upregulated cell junction constituents connexin 43 and zona occludens 1, while downregulating an extracellular matrix-degrading enzyme tissue plasminogen activator, all of which were reversed by (P)RR blockade. In contrast, angiotensin II application upregulated a pro-angiogenic factor placental growth factor alone, which was abolished by AT1R blockade. Consistently, (P)RR and AT1R co-localized with these corresponding proteins in patient TM tissues. Oxidative stress, a known etiology for glaucoma, induced the expression of prorenin and angiotensinogen in human TM cells. These data suggest the contribution of RAPS to the molecular pathogenesis of POAG and NVG through TM tissue remodeling and AC angle angiogenesis.
| S-EPMC7465309 | biostudies-literature
Project description:PurposeTreatment with corticosteroids can result in ocular hypertension and may lead to the development of steroid-induced glaucoma. The extent to which biomechanical changes in trabecular meshwork (TM) cells and extracellular matrix (ECM) contribute toward this dysfunction is poorly understood.MethodsPrimary human TM (HTM) cells were cultured for either 3 days or 4 weeks in the presence or absence of dexamethasone (DEX), and cell mechanics, matrix mechanics and proteomics were determined, respectively. Adult rabbits were treated topically with either 0.1% DEX or vehicle over 3 weeks, and mechanics of the TM were determined.ResultsTreatment with DEX for 3 days resulted in a 2-fold increase in HTM cell stiffness, and this correlated with activation of extracellular signal-related kinase 1/2 (ERK1/2) and overexpression of α-smooth muscle actin (αSMA). Further, the matrix deposited by HTM cells chronically treated with DEX is approximately 4-fold stiffer, more organized, and has elevated expression of matrix proteins commonly implicated in glaucoma (decorin, myocilin, fibrillin, secreted frizzle-related protein [SFRP1], matrix-gla). Also, DEX treatment resulted in a 3.5-fold increase in stiffness of the rabbit TM.DiscussionThis integrated approach clearly demonstrates that DEX treatment increases TM cell stiffness concurrent with elevated αSMA expression and activation of the mitogen-activated protein kinase (MAPK) pathway, stiffens the ECM in vitro along with upregulation of Wnt antagonists and fibrotic markers embedded in a more organized matrix, and increases the stiffness of TM tissues in vivo. These results demonstrate glucocorticoid treatment can initiate the biophysical alteration associated with increased resistance to aqueous humor outflow and the resultant increase in IOP.
| S-EPMC4509060 | biostudies-literature
Project description:PurposeTo contrast genome-wide gene expression profiles of cultured human trabecular meshwork (HTM) cells to that of control and primary open angle glaucoma (POAG) HTM tissues.MethodsCultured HTM cells, HTM tissue dissected from control donors, and HTM tissue from POAG donors receiving medication for glaucoma were fixed in RNA latertrade mark. Total RNA extracted from these samples was linearly amplified with the Ovation Biotin RNA Amplification and Labeling System and individually hybridized to Affymetrix Human Genome U133 Plus 2.0 high density microarrays. Data analysis was performed using GeneSpring Software 7.0. Selected genes showing significant differential expression were validated by quantitative real-time PCR in nonamplified RNA.ResultsCultured HTM cells retained the expression of some genes characteristic of HTM tissue, including chitinase 3-like 1 and matrix Gla protein, but demonstrated downregulation of physiologically important genes such as myocilin. POAG HTM tissue showed relatively small changes compared to that of control donors. These changes included the statistically significant upregulation of several genes associated with inflammation and acute-phase response, including selectin-E (ELAM-I), as well as the downregulation of the antioxidants paraoxonase 3 and ceruloplasmin.ConclusionsDownregulation in cultured HTM cells of genes potentially relevant for outflow pathway function highlights the importance of developing new conditions for the culture of TM cells capable of preserving the characteristics of TM cells in vivo. Comparative analysis between control and POAG tissues suggests that the upregulation of inflammation-associated genes might be involved in the progression of glaucoma.
| S-EPMC3152462 | biostudies-literature