The Orai Ca²⁺ channel inhibitor CM4620 targets both parenchymal and immune cells to reduce inflammation in experimental acute pancreatitis

Abstract

Key points This work confirms previous reports that CM4620, a small molecule inhibitor of Ca2+ entry via store operated Ca2+ entry (SOCE) channels formed by stromal interaction molecule 1 (STIM1)/Orai complexes, attenuates acinar cell pathology and acute pancreatitis in mouse experimental models. Here we report that intravenous administration of CM4620 reduces the severity of acute pancreatitis in the rat, a hitherto untested species. Using CM4620, we probe further the mechanisms whereby SOCE via STIM1/Orai complexes contributes to the disease in pancreatic acinar cells, supporting a role for endoplasmic reticulum stress/cell death pathways in these cells. Using CM4620, we show that SOCE via STIM1/Orai complexes promotes neutrophil oxidative burst and inflammatory gene expression during acute pancreatitis, including in immune cells which may be either circulating or invading the pancreas. Using CM4620, we show that SOCE via STIM1/Orai complexes promotes activation and fibroinflammatory gene expression within pancreatic stellate cells. Abstract Key features of acute pancreatitis include excess cellular Ca2+ entry driven by Ca2+ depletion from the endoplasmic reticulum (ER) and subsequent activation of store‐operated Ca2+ entry (SOCE) channels in the plasma membrane. In several cell types, including pancreatic acinar, stellate cells (PaSCs) and immune cells, SOCE is mediated via channels composed primarily of Orai1 and stromal interaction molecule 1 (STIM1). CM4620, a selective Orai1 inhibitor, prevents Ca2+ entry in acinar cells. This study investigates the effects of CM4620 in preventing or reducing acute pancreatitis features and severity. We tested the effects of CM4620 on SOCE, trypsinogen activation, acinar cell death, activation of NFAT and NF‐κB, and inflammatory responses in ex vivo and in vivo rodent models of acute pancreatitis and human pancreatic acini. We also examined whether CM4620 inhibited cytokine release in immune cells, fibro‐inflammatory responses in PaSCs, and oxidative burst in neutrophils, all cell types participating in pancreatitis. CM4620 administration to rats by i.v. infusion starting 30 min after induction of pancreatitis significantly diminished pancreatitis features including pancreatic oedema, acinar cell vacuolization, intrapancreatic trypsin activity, cell death signalling and acinar cell death. CM4620 also decreased myeloperoxidase activity and inflammatory cytokine expression in pancreas and lung tissues, fMLF peptide‐induced oxidative burst in human neutrophils, and cytokine production in human peripheral blood mononuclear cells (PBMCs) and rodent PaSCs, indicating that Orai1/STIM1 channels participate in the inflammatory responses of these cell types during acute pancreatitis. These findings support pathological Ca2+ entry‐mediated cell death and proinflammatory signalling as central mechanisms in acute pancreatitis pathobiology.

Auxora versus standard of care for the treatment of severe or critical COVID-19 pneumonia: results from a randomized controlled trial

“…Evidence suggests that calcium release-activated calcium (CRAC) channels play a role in inflammationinduced injury of pulmonary endothelial cells, resulting in loss of alveolar-capillary barrier function and extravasation of fluid into the alveoli [6][7][8][9]. CRAC channel activation is also linked to the production of proinflammatory cytokines associated with worsened outcomes in COVID-19 [7][8][9][10][11]. Thus, inhibition of CRAC channels may be beneficial in preserving pulmonary endothelial integrity, reducing proinflammatory cytokine levels, and improving oxygenation in patients with COVID-19 pneumonia [8,[11][12][13][14].…”

Auxora Versus Standard of Care For The Treatment of Severe or Critical COVID-19 Pneumonia: Results From A Randomized Controlled Trial

“…[7][8][9] CRAC channel activation also initiates the production and release of proin ammatory cytokines from immune cells. 10,11 The resulting development of pulmonary edema, hypoxemia, and ultimately ARDS contributes to the signi cant morbidity and mortality seen in COVID-19 pneumonia, particularly in those who eventually require invasive mechanical ventilation. 14,18 As demonstrated in animal models, inhibition of CRAC channels stabilizes pulmonary endothelial cells, blocks the release of proin ammatory cytokines and decreases vascular in ammation and permeability.…”

“…Baseline demographics were balanced across the Auxora and standard of care groups in Arm A (Table 2), but more patients in the Auxora group had diabetes (47%) than in the standard of care group (22%). The median time (min, max) from symptom onset to randomization was nine (4, 34) days in the Auxora group and seven (4,11) days in the standard of care group. The baseline mean imputed PaO 2 /FiO 2 was 178±74 in the Auxora group and 168±78 in the standard of care group.…”

p.E152K-STIM1 mutation deregulates Ca2+signaling contributing to chronic pancreatitis

“…The sustained Ca 2+ signals and cytosolic Ca 2+ overload contribute to the development of acute pancreatitis (Gerasimenko et al, 2009;Lur et al, 2011;Wen et al, 2015) through initiating activation of intracellular proteases responsible for cell autodigestion (Raraty et al, 2000;Gerasimenko et al, 2013;Zhu et al, 2018). Actually, the inhibition of calcium channel activity has been described as protective in pancreatitis and represents a therapeutic option (Son et al, 2019;Waldron et al, 2019).…”