J Physiol. 2022 Nov;600(22):4827-4848. doi: 10.1113/JP283811. Epub 2022 Oct 19.
Chronic reduction of store operated Ca2+ entry is viable therapeutically but is associated with cardiovascular complications
Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar. Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA. College of Health and Life Science, Hamad bin Khalifa University, Doha, Qatar. Anti-Doping Lab Qatar, Doha, Qatar. Medical Program, Weill Cornell Medicine Qatar, Doha, Qatar. Heart Hospital, Hamad Medical Corporation, Doha, Qatar. Department of Pediatrics, Weill Cornell Medicine, New York, NY, USA. Division of Nephrology and Hypertension, Departments of Medicine and Transplantation Medicine, New York Presbyterian Hospital - Weill Cornell Medical College, New York, NY, USA.
Service type: Knock-in mice
Loss of function mutations in store-operated Ca2+ entry (SOCE) are associated with severe paediatric disorders in humans, including combined immunodeficiency, anaemia, thrombocytopenia, anhidrosis and muscle hypotonia. Given its central role in immune cell activation, SOCE has been a therapeutic target for autoimmune and inflammatory diseases. Treatment for such chronic diseases would require prolonged SOCE inhibition. It is, however, unclear whether chronic SOCE inhibition is viable therapeutically. Here we address this issue using a novel genetic mouse model (SOCE hypomorph) with deficient SOCE, nuclear factor of activated T cells activation, and T cell cytokine production. SOCE hypomorph mice develop and reproduce normally and do not display muscle weakness or overt anhidrosis. They do, however, develop cardiovascular complications, including hypertension and tachycardia, which we show are due to increased sympathetic autonomic nervous system activity and not cardiac or vascular smooth muscle autonomous defects. These results assert that chronic SOCE inhibition is viable therapeutically if the cardiovascular complications can be managed effectively clinically. They further establish the SOCE hypomorph line as a genetic model to define the therapeutic window of SOCE inhibition and dissect toxicities associated with chronic SOCE inhibition in a tissue-specific fashion. KEY POINTS: A floxed stromal interaction molecule 1 (STIM1) hypomorph mouse model was generated with significant reduction in Ca2+ influx through store-operated Ca2+ entry (SOCE), resulting in defective nuclear translocation of nuclear factor of activated T cells, cytokine production and inflammatory response. The hypomorph mice are viable and fertile, with no overt defects. Decreased SOCE in the hypomorph mice is due to poor translocation of the mutant STIM1 to endoplasmic reticulum-plasma membrane contact sites resulting in fewer STIM1 puncta. Hypomorph mice have similar susceptibility to controls to develop diabetes but exhibit tachycardia and hypertension. The hypertension is not due to increased vascular smooth muscle contractility or vascular remodelling. The tachycardia is not due to heart-specific defects but rather seems to be due to increased circulating catecholamines in the hypomorph. Therefore, long term SOCE inhibition is viable if the cardiovascular defects can be managed clinically.
Keywords: STIM1; hypertension; immunodeficiency; store-operated Ca2+ entry; tachycardia.