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Biology subjects

Jacob, P. M.

Publications and source records attributed to Jacob, P. M..

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↗

The plant immune receptors NRG1.1 and ADR1 are calcium influx channels

Plant nucleotide-binding leucine-rich repeat receptors (NLRs) regulate immunity and cell death. RPW8 domain-containing "helper" NLRs (RNLs) are required by many "sensor" NLRs. Our crystal structure of the RNL N REQUIREMENT GENE 1.1 (NRG1.1) N-terminal signaling domain resembled that of the resting state plant resistosome-forming HOPZ-ACTIVATED RESISTANCE 1 (ZAR1) and the animal MIXED-LINEAGE KINASE-LIKE (MLKL) cation channel. Active NRG1.1 oligomerized, was enriched in plasma membrane puncta and conferred cytoplasmic Ca2+ influx in plant and human HeLa cells. NRG1.1-dependent Ca2+ influx and cell death were sensitive to Ca2+ channel blockers. Ca2+ influx and cell death mediated by NRG1.1 and ACTIVATED DISEASE RESISTANCE 1 (ADR1), another RNL, required conserved negatively charged N-terminal residues. Thus, RNLs apparently form influx channels to directly regulate cytoplasmic [Ca2+] and consequent cell death. One Sentence SummaryA specific class of plant immune receptors function as calcium-permeable channels upon activation to induce cell death.

plant biology↗