Store-operated calcium entry-associated regulatory factor regulates airway inflammation and airway remodeling in asthma mice models

Abstract

Store-operated calcium entry (SOCE) is involved in the pathogenesis of airway inflammation and remodeling in asthma. Store-operated calcium entry-associated regulatory factor (SARAF) can downregulate SOCE. We sought to investigate the role of SARAF in the regulation of airway inflammation and remodeling in asthma mice models, as well as in the functional regulation of human airway smooth muscle cells (hASMCs). Balb/c mice were sensitized and challenged with ovalbumin to establish the asthma mice models. Mice were transfected with lentivirus, which expressed the SARAF gene + GFP (green fluorescence protein) or the negative control gene + GFP. Airway resistance was measured with the animal pulmonary function system. Airway inflammation and remodeling were evaluated via histological staining. In vitro cultured hASMCs were transfected with scrambled small interfering RNA (siRNA) or SARAF-specific siRNA, respectively. The proliferation, migration rate, hypertrophy, and SOCE activity of hASMCs were examined with Cell Counting Kit-8, wound healing test, bright field imaging, and Ca²⁺ fluorescence imaging, respectively. SARAF expression was measured by quantitative real-time PCR. Asthma mice models showed decreased SARAF mRNA expression in the lungs. SARAF overexpression attenuated airway inflammation, resistance, and also remodeling. Downregulation of SARAF expression with siRNA promoted the proliferation, migration, hypertrophy, and SOCE activity in hASMCs. SARAF plays a protective role against airway inflammation and remodeling in asthma mice models by blunting SOCE; SARAF may also be a functional regulating factor of hASMCs.

Keywords: airway inflammation; airway remodeling; airway smooth muscle cells; asthma; store-operated calcium entry-associated regulatory factor.