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Biology subjects

Ananthan, A. S.

Publications and source records attributed to Ananthan, A. S..

2 recordsLinked to original sources

Mindin is essential for cutaneous fibrogenesis in a new mouse model of systemic sclerosis

Fibrosis is a result of chronically activated fibroblasts leading to the overproduction of extracellular matrix (ECM), causing tissue hardening and loss of organ function. Systemic sclerosis (SSc) is a fibrotic skin disease marked by inflammation, autoimmunity and vasculopathy along with progressive fibrosis of the skin and internal organs. A major bottleneck in understanding the etiology of SSc has been the lack of a holistic animal model that can mimic the human SSc disease. We found that the transcription factor Snail is overexpressed in the epidermis of SSc patients and a transgenic mouse recapitulating this expression pattern is sufficient to induce hallmark clinical features of the human disease. Using this mouse model as a discovery platform, we have uncovered a critical role for the matricellular protein Mindin in fibrogenesis. Mindin is produced by Snail transgenic skin keratinocytes and aids fibrogenesis by inducing inflammatory cytokine and collagen production in resident dermal fibroblasts. Given the dispensability of Mindin in normal tissue physiology, targeting this protein holds promise as an effective therapy for fibrosis.

pathology↗

Extracellular Caspase-1 regulates migration of hair follicle stem cells upon wounding

The wound-healing process is a paradigm of the directed migration of various pools of stem cells from their niche to the site of injury where they replenish damaged cells. Two decades have elapsed since the observation that wounding activates multipotent hair follicle stem cells to infiltrate the epidermis, but the cues that coax these cells out of their niche remains unknown. Using an excisional wound and genetic mouse models of wound healing, we discovered that Caspase-1, a protein classically known as an integral component of the cytosolic inflammasome, is secreted and has a non-canonical role in the extracellular milieu. Through its Caspase Activation Recruitment Domain (CARD), Caspase-1 is sufficient to initiate chemotaxis of hair follicle stem cells into the epidermis. Uncovering this novel function of Caspase-1 also facilitates a deeper understanding of the mechanistic basis of the epithelial hyperplasia found to accompany numerous inflammatory skin diseases.

cell biology↗