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

Ricardo Ferrari, Bowen Xie, Edwyn Assaf, Kristin Morder, Melanie Scott, Hong Liao, Michael J. Calderon, Mark Ross, Patricia Loughran, Simon C. Watkins, Iraklis Pipinos, George Casale, Edith Tzeng, Ryan McEnaney, Ulka Sachdev

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


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.

Original languageEnglish (US)
Article number1163
Issue number7
StatePublished - Apr 1 2022


  • Caspase-5
  • Inflammasomes
  • Myoblasts
  • Peripheral arterial disease

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology


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