Inflammatory Caspase Activity Mediates HMGB1 Release and Differentiation in Myoblasts Affected by Peripheral Arterial Disease

• Published in: Cells (Basel, Switzerland) Vol. 11; no. 7; p. 1163
• Main Authors: Ferrari, Ricardo, Xie, Bowen, Assaf, Edwyn, Morder, Kristin, Scott, Melanie, Liao, Hong, Calderon, Michael J, Ross, Mark, Loughran, Patricia, Watkins, Simon C, Pipinos, Iraklis, Casale, George, Tzeng, Edith, McEnaney, Ryan, Sachdev, Ulka
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.03.2022; MDPI
• Subjects: Angiogenesis; Animal models; Animals; Apoptosis; Biopsy; Caspase 1 - metabolism; Caspase-1; Caspase-4; Caspase-5; Caspases - metabolism; Disease; DNA damage; Gangrene; HMGB1 Protein; Human subjects; Inflammasomes; Inflammasomes - metabolism; Inflammation; Intermittent claudication; Ischemia; Mice; mRNA; Myoblasts; Myoblasts - metabolism; MyoD protein; Myogenin; Nigericin; Peripheral Arterial Disease; Reagents; RNA, Messenger - metabolism; United States > US; Germany; caspase-5; myoblasts; peripheral arterial disease; inflammasomes
• ISSN: 2073-4409; 2073-4409
• DOI: 10.3390/cells11071163

Introduction: We previously showed that caspase-1 and -11, which are activated by inflammasomes, mediate recovery from muscle ischemia in mice. We hypothesized that similar to murine models, inflammatory caspases modulate myogenicity and inflammation in ischemic muscle disease. Methods: Caspase activity was measured in ischemic and perfused human myoblasts in response to the NLRP3 and AIM2 inflammasome agonists (nigericin and poly(dA:dT), respectively) with and without specific caspase-1 or pan-caspase inhibition. mRNA levels of myogenic markers and caspase-1 were assessed, and protein levels of caspases-1, -4, -5, and -3 were measured by Western blot. Results: When compared to perfused cells, ischemic myoblasts demonstrated attenuated MyoD and myogenin and elevated caspase-1 mRNA. Ischemic myoblasts also had significantly higher enzymatic caspase activity with poly(dA:dT) (p < 0.001), but not nigericin stimulation. Inhibition of caspase activity including caspase-4/-5, but not caspase-1, blocked activation effects of poly(dA:dT). Ischemic myoblasts had elevated cleaved caspase-5. Inhibition of caspase activity deterred differentiation in ischemic but not perfused myoblasts and reduced the release of HMGB1 from both groups. Conclusion: Inflammatory caspases can be activated in ischemic myoblasts by AIM2 and influence ischemic myoblast differentiation and release of pro-angiogenic HMGB1. AIM2 inflammasome involvement suggests a role as a DNA damage sensor, and our data suggest that caspase-5 rather than caspase-1 may mediate the downstream mediator of this pathway.