The effects of hydrogen sulfide on HEK-293 cells and human primary bronchial fibroblasts

Kaura, Vikas

Abstract

Hydrogen sulfide (H2S) is a key biologically relevant signalling molecule and has been recognised as the third endogenous gasotransmitter. H2S modulates various biological functions through complex mechanisms which may involve Transient Receptor Potential (TRP) channels such as TRPA1. TRPA1 is postulated to play a prominent role in pulmonary inflammation and airway hypersensitivity. H2S has been found to also modulate cell growth and survival, with high concentrations leading to reactive airway disease, acute respiratory failure and pulmonary fibrosis. N-Acetylcysteine (NAC) is a thiol precursor of L-Cysteine which elicits antioxidant effects and has been implicated in preventing the progression of pulmonary fibrosis. The aim of the study was to examine the effects of H2S on TRPA1 and human primary bronchial fibroblasts (HPBF).

Initial experiments sought to examine the effects of NaHS on HEK293 cells transfected with TRPA1 (HEK-TRPA1) using fluorometric calcium assays. These assays were hampered by a direct reaction between the H2S donor NaHS and the fluorescent dye. However this has led to the identification of a putative new H2S sensor.

Next, untransfected HPBF and HEK-TRPA1 were treated with NaHS or with NAC, and the effects assessed using a five-day growth assay. Chronic NaHS exposure induced a significant reduction in the growth of HEK-TRPA1 cells. Furthermore an acute 30 minute treatment with NaHS significantly reduced the growth of both HEK-TRPA1 cells and HPBFs, whereas NAC only inhibited growth of the latter.

The NAC mediated inhibition in HPBF growth provides in vitro evidence for the potential anti-fibrotic actions of NAC in the lung. The inhibitory effects on growth at day five following a brief 30 minute NaHS exposure is a novel finding that requires further investigation to elucidate the mechanism of action. This could potentially provide a better understanding of the effects of H2S in modulating the progression from inflammation to fibrosis.

Citation

Kaura, V. The effects of hydrogen sulfide on HEK-293 cells and human primary bronchial fibroblasts. (Thesis). Hull York Medical School, the University of Hull and the University of York. https://hull-repository.worktribe.com/output/4218567

• Thesis Type: Thesis
• Deposit Date: Oct 14, 2016
• Publicly Available Date: Feb 23, 2023
• Keywords: Medicine
• Public URL: https://hull-repository.worktribe.com/output/4218567
• Additional Information: Hull York Medical School, The University of Hull and the University of York
• Award Date: Oct 1, 2015