Puttagunta, L. | bioRxiv Science

bioRxiv2024

Human pulmonary neuroendocrine cells respond to House dust mite extract with PAR-1 dependent release of CGRP

BackgroundPulmonary neuroendocrine cells (PNEC) are rare airway epithelial cells that have recently gained attention as potential amplifiers of allergic asthma. However, studying PNEC function in humans has been challenging due to a lack of cell isolation methods and little is known about human PNEC function in response to asthma relevant stimuli. Here we developed and characterized an in vitro human PNEC model and investigated the neuroendocrine response to extracts of the common aeroallergen house dust-mite. (HDM). MethodsPNEC enriched cultures were generated from human induced pluripotent stem cells (iPNEC) and primary bronchial epithelial cells (ePNEC). Characterized PNEC cultures were exposed to HDM extract, a volatile chemical odorant (Bergamot oil), or the bacterial membrane component, lipopolysaccharide (LPS) and neuroendocrine gene expression and neuropeptide release determined. ResultsBoth iPNEC and ePNEC models demonstrated similar baseline neuroendocrine characteristics and a stimuli specific modulation of gene expression. Most notably, exposure to HDM but not Bergamot oil or LPS, lead to dose dependent induction of the CGRP encoding gene, CALCB, and corresponding release of the neuropeptide. HDM induced CALCB expression and CGRP release could be inhibited by a protease activated receptor 1 (PAR1) antagonist or protease inhibitors and was mimicked by a PAR1 agonist. ConclusionsWe have characterized a novel model of PNEC enriched human airway epithelium and utilized this model to demonstrate a previously unrecognized role for human PNEC in mediating a direct neuroendocrine response to aeroallergen exposure and highlighting CGRP production by these cells as a potential therapeutic target in allergic asthma.

cell biology↗

bioRxiv2023

Identification and Characterization of Calcium Binding Protein, Spermatid Associated 1 (CABS1) in Selected Human Tissues and Fluids

Calcium binding protein, spermatid associated 1 (CABS1) is a protein most widely studied in spermatogenesis. However, mRNA for CABS1 has been found in numerous tissues, albeit with little information about the protein. Previously, we identified CABS1 mRNA and protein in human salivary glands and provided evidence that in humans CABS1 contains a heptapeptide near its carboxyl terminus that has anti-inflammatory activities. Moreover, levels of an immunoreactive form of CABS1 were elevated in psychological stress. To more fully characterize human CABS1 we developed additional polyclonal and monoclonal antibodies to different sections of the protein and used these antibodies to characterize CABS1 in an overexpression cell lysate, human salivary glands, saliva, serum and testes using western blot, immunohistochemistry and bioinformatics approaches exploiting the Gene Expression Omnibus (GEO) database. CABS1 appears to have multiple molecular weight forms, consistent with its recognition as a structurally disordered protein, a protein with structural plasticity. Interestingly, in human testes, its cellular distribution differs from that in rodents and pigs, and includes Leydig cells, primary spermatogonia, Sertoli cells and developing spermatocytes and spermatids, Geodata suggests that CABS1 is much more widely distributed than previously recognized, including in the urogenital, gastrointestinal and respiratory tracts, as well as in the nervous system, immune system and other tissues. Much remains to be learned about this intriguing protein.

cell biology↗