SKF96365 activates calcium-sensing receptors in pulmonary arterial smooth muscle cells

• Published in: Biochemical and biophysical research communications 2022-06, Vol.607, p.44-48
• Main Authors: Miyaki, Riko, Yamamura, Aya, Kawade, Akiko, Fujiwara, Moe, Kondo, Rubii, Suzuki, Yoshiaki, Yamamura, Hisao
• Format: Article
• Language: English
• Subjects: Calcium - metabolism; Calcium-sensing receptor; Cell Proliferation; Cells, Cultured; Cytosolic calcium concentration; Familial Primary Pulmonary Hypertension - pathology; Humans; Hypertension, Pulmonary - metabolism; Imidazoles; Myocytes, Smooth Muscle - metabolism; Pulmonary artery; Pulmonary Artery - pathology; Pulmonary hypertension; Receptors, Calcium-Sensing - metabolism; SKF96365; Smooth muscle
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2022.03.121

In pulmonary arterial smooth muscle cells (PASMCs), an increase in the cytosolic Ca2+ concentration ([Ca2+]cyt) is involved in many physiological processes such as cell contraction and proliferation. However, chronic [Ca2+]cyt increases cause pulmonary vasoconstriction and vascular remodeling, resulting in pulmonary arterial hypertension (PAH). Therefore, [Ca2+]cyt signaling plays a substantial role in the regulation of physiological and pathological functions in PASMCs. In the present study, the effects of SKF96365 on [Ca2+]cyt were examined in PASMCs from normal subjects and idiopathic pulmonary arterial hypertension (IPAH) patients. SKF96365 is widely used as a blocker of non-selective cation channels. SKF96365 did not affect the resting [Ca2+]cyt in normal-PASMCs. However, SKF96365 increased [Ca2+]cyt in IPAH-PASMCs in a concentration-dependent manner (EC50 = 18 μM). The expression of Ca2+-sensing receptors (CaSRs) was higher in IPAH-PASMCs than in normal-PASMCs. The SKF96365-induced [Ca2+]cyt increase was inhibited by CaSR antagonists, NPS2143 and Calhex 231. The CaSR-mediated [Ca2+]cyt increase was facilitated by SKF96365 and the activation was blocked by NPS2143 or Calhex 231. In addition, the SKF96365-induced [Ca2+]cyt increase was reduced by siRNA knockdown of CaSRs. Taken together, SKF96365 activates CaSRs in IPAH-PASMCs and promotes [Ca2+]cyt signaling. •SKF96365 is widely used as a blocker of non-selective cation channels.•Ca2+-sensing receptor (CaSR) functions in the regulation of cytosolic [Ca2+].•Expression of CaSR upregulates in patients with pulmonary arterial hypertension.•SKF96365 activates CaSRs and increases cytosolic [Ca2+].•Off-target effects of SKF96365 must be considered in the pharmacological experiments.