TY - JOUR
T1 - Role of mitochondria in the myopathy of juvenile dermatomyositis and implications for skeletal muscle calcinosis
AU - Duvvuri, Bhargavi
AU - Pachman, Lauren M.
AU - Hermanson, Payton
AU - Wang, Ting
AU - Moore, Richard
AU - Ding-Hwa Wang, Dennis
AU - Long, Aaron
AU - Morgan, Gabrielle A.
AU - Doty, Stephen
AU - Tian, Rong
AU - Sancak, Yasemin
AU - Lood, Christian
N1 - Funding Information:
This work was supported by Seattle Children's Hospital Cure JM Center of Excellence grant, National Institutes of Health grant R21AR077565 , National Institutes of Health grant R21AR079542 , and National Institutes of Health grant R01HL158606 to CL, National Institutes of Health (NIH) UL1TR001422 and The Cure JM Foundation for Maintenance of the JM Repository; Jacque Den Uyl and other appreciated donors to LMP.
Publisher Copyright:
© 2023 The Authors
PY - 2023/7
Y1 - 2023/7
N2 - Objectives: To elucidate mechanisms contributing to skeletal muscle calcinosis in patients with juvenile dermatomyositis. Methods: A well-characterized cohorts of JDM (n = 68), disease controls (polymyositis, n = 7; juvenile SLE, n = 10, and RNP + overlap syndrome, n = 12), and age-matched health controls (n = 17) were analyzed for circulating levels of mitochondrial (mt) markers including mtDNA, mt-nd6, and anti-mitochondrial antibodies (AMAs) using standard qPCR, ELISA, and novel-in-house assays, respectively. Mitochondrial calcification of affected tissue biopsies was confirmed using electron microscopy and energy dispersive X-ray analysis. A human skeletal muscle cell line, RH30, was used to generate an in vitro calcification model. Intracellular calcification is measured by flow cytometry and microscopy. Mitochondria were assessed for mtROS production and membrane potential by flow cytometry and real-time oxygen consumption rate by Seahorse bioanalyzer. Inflammation (interferon-stimulated genes) was measured by qPCR. Results: In the current study, patients with JDM exhibited elevated levels of mitochondrial markers associated with muscle damage and calcinosis. Of particular interest are AMAs predictive of calcinosis. Human skeletal muscle cells undergo time- and dose-dependent accumulation of calcium phosphate salts with preferential localization to mitochondria. Calcification renders skeletal muscle cells mitochondria stressed, dysfunctional, destabilized, and interferogenic. Further, we report that inflammation induced by interferon-alpha amplifies mitochondrial calcification of human skeletal muscle cells via the generation of mitochondrial reactive oxygen species (mtROS). Conclusions: Overall, our study demonstrates the mitochondrial involvement in the skeletal muscle pathology and calcinosis of JDM and mtROS as a central player in the calcification of human skeletal muscle cells. Therapeutic targeting of mtROS and/or upstream inducers, such as inflammation, may alleviate mitochondrial dysfunction, leading to calcinosis. AMAs can potentially identify patients with JDM at risk for developing calcinosis.
AB - Objectives: To elucidate mechanisms contributing to skeletal muscle calcinosis in patients with juvenile dermatomyositis. Methods: A well-characterized cohorts of JDM (n = 68), disease controls (polymyositis, n = 7; juvenile SLE, n = 10, and RNP + overlap syndrome, n = 12), and age-matched health controls (n = 17) were analyzed for circulating levels of mitochondrial (mt) markers including mtDNA, mt-nd6, and anti-mitochondrial antibodies (AMAs) using standard qPCR, ELISA, and novel-in-house assays, respectively. Mitochondrial calcification of affected tissue biopsies was confirmed using electron microscopy and energy dispersive X-ray analysis. A human skeletal muscle cell line, RH30, was used to generate an in vitro calcification model. Intracellular calcification is measured by flow cytometry and microscopy. Mitochondria were assessed for mtROS production and membrane potential by flow cytometry and real-time oxygen consumption rate by Seahorse bioanalyzer. Inflammation (interferon-stimulated genes) was measured by qPCR. Results: In the current study, patients with JDM exhibited elevated levels of mitochondrial markers associated with muscle damage and calcinosis. Of particular interest are AMAs predictive of calcinosis. Human skeletal muscle cells undergo time- and dose-dependent accumulation of calcium phosphate salts with preferential localization to mitochondria. Calcification renders skeletal muscle cells mitochondria stressed, dysfunctional, destabilized, and interferogenic. Further, we report that inflammation induced by interferon-alpha amplifies mitochondrial calcification of human skeletal muscle cells via the generation of mitochondrial reactive oxygen species (mtROS). Conclusions: Overall, our study demonstrates the mitochondrial involvement in the skeletal muscle pathology and calcinosis of JDM and mtROS as a central player in the calcification of human skeletal muscle cells. Therapeutic targeting of mtROS and/or upstream inducers, such as inflammation, may alleviate mitochondrial dysfunction, leading to calcinosis. AMAs can potentially identify patients with JDM at risk for developing calcinosis.
KW - Calcinosis
KW - Interferon
KW - Juvenile dermatomyositis
KW - Mitochondria
KW - Mitochondrial reactive oxygen species
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U2 - 10.1016/j.jaut.2023.103061
DO - 10.1016/j.jaut.2023.103061
M3 - Article
C2 - 37244073
AN - SCOPUS:85162212194
SN - 0896-8411
VL - 138
JO - Journal of Autoimmunity
JF - Journal of Autoimmunity
M1 - 103061
ER -
