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Biology subjects

Maddala, R.

Publications and source records attributed to Maddala, R..

2 recordsLinked to original sources

Chromatin dynamics identifies 78 genes at loci associated with elevated intraocular pressure and primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is a chronic neurodegenerative disorder, and elevated intraocular pressure (IOP) represents the major, and only modifiable, risk factor for the disease. We modeled increased IOP by treating three primary human trabecular meshwork (TM) cell strains with dexamethasone, then generated a high-resolution map of promoter-centered chromatin contacts and regulatory modules to decipher how the genomic architecture and epigenetic state of disease-associated loci contribute to pathogenesis. We identify dynamic changes in chromatin compartments and looping, cis-regulatory elements and transcription factor hubs corresponding to altered transcriptional profile. By integrating GWAS-associated variants with dexamethasone-induced 3D chromatin landscape, we discovered 26 IOP- and 52 POAG- candidate causal genes, which belong to vesicle transport, TLR, MAPK and hippo-YAP signaling pathways. We also uncovered transcriptional regulatory role of 103 non-coding lead variants. Our studies provide a mechanistic framework of genetic complexity associated with ocular hypertension and POAG pathogenesis in addition to targets for therapies.

genomics↗

Ankyrin-B is required for the establishment and maintenance of lens cytoarchitecture, mechanics, and clarity

Summary StatementThis study illustrates a vital role for ankyrin-B in lens architecture, growth and function through its involvement in membrane protein and spectrin-actin cytoskeletal organization and stability The transparent ocular lens is essential for vision by focusing light onto the retina. Despite recognizing the importance of its unique cellular architecture and mechanical properties, the molecular mechanisms governing these attributes remain elusive. This study aims to elucidate the role of ankyrin-B (AnkB), a membrane scaffolding protein, in lens cytoarchitecture, growth and function using a conditional knockout (cKO) mouse model. AnkB cKO mouse has no defects in lens morphogenesis, but exhibited changes that supported a global role for AnkB in maintenance of lens clarity, size, cytoarchitecture, and stiffness. Notably, absence of AnkB led to nuclear cataract formation, evident from P16. AnkB cKO lens fibers exhibit progressive disruption in membrane organization of the spectrin-actin cytoskeleton, channel proteins, cell-cell adhesion, shape change, loss and degradation of several membrane proteins (e.g., NrCAM. N-cadherin and aquaporin-0) along with a disorganized plasma membrane and impaired ball-and-socket membrane interdigitations. Furthermore, absence of AnkB led to decreased lens stiffness. Collectively, these results illustrate the essential role for AnkB in lens architecture, growth and function through its involvement in membrane protein and cytoskeletal organization.

cell biology↗