Dhruva Gopalakrishnan
Pronouns: He/Him
Research Mentor(s): Swati Bhattacharyya
Research Mentor School/College/Department: Internal Medicine, Rheumatology / Medicine
Program:
Authors: Dhruva Gopalakrishnan, Sonia Ling, Priyanka Verma, Matija Bajzelj, Swati Bhattacharyya
Session: Session 5: 2:40 pm – 3:30 pm
Poster: 97
Abstract
Scleroderma, or Systemic Sclerosis(SSc), is a rare, autoimmune connective tissue disorder with severe multi-organ fibrosis, and no effective treatments. It has an incidence rate of 300,000 Americans aged 25 to 55 years, affecting five females to every male. Transforming growth factor-ß(TGF-ß) is a well-documented pro-fibrotic mediator that can stimulate collagen synthesis. Prior research showed that the histone acetyltransferase(HAT) p300 is upregulated in SSc patients. Moreover, p300-catalyzed histone hyperacetylation plays a key role in TGF-ß-driven collagen stimulation. Library screening of small-molecule discovered A485 as potent and specific blocker of p300 HAT activity. Here we sought to determine the impact of inhibiting HAT activity of fibrosis using normal skin fibroblasts, and SSc-explanted skin fibroblasts. OBJECTIVE:To investigate the novel anti-fibrotic role of A485, a highly selective p300 HAT inhibitor, in TGF-ß-induced skin fibroblasts and skin fibroblasts derived from SSc patients. METHODS:Skin fibroblasts from SSc patients were treated with A485. Normal human skin fibroblasts from healthy subjects were pre-treated with A485, and then stimulated with TGF-ß1. Protein samples were immunoblotted with antibodies against alpha-smooth muscle actin, collagen type I and GAPDH(loading control). RNA followed by qPCR was tested for fibrosis-related genes(COL1A1, COL1A2, ASMA) and GAPDH(endogenous control). RESULTS:Our results demonstrate that inhibiting p300 HAT activity by A485 abrogated TGF-ß1-stimulated collagen synthesis and myofibroblasts differentiation in healthy skin fibroblasts. Interestingly, treatment of SSc skin fibroblasts with A485-ameliorated constitutive activation as shown by qPCR, western-blotting, and immunofluorescent imaging. CONCLUSIONS:Our findings suggest that A485 is a potent suppressor of pro-fibrotic signaling in SSc patients and warrants further investigation.
