TY - JOUR
T1 - Mir-181c activates mitochondrial calcium uptake by regulating micu1 in the heart
AU - Banavath, Hemanth N.
AU - Roman, Barbara
AU - Mackowski, Nathan
AU - Biswas, Debjit
AU - Afzal, Junaid
AU - Nomura, Yohei
AU - Solhjoo, Soroosh
AU - O’Rourke, Brian
AU - Kohr, Mark
AU - Murphy, Elizabeth
AU - Steenbergen, Charles
AU - Das, Samarjit
N1 - Publisher Copyright:
© 2019 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
PY - 2019
Y1 - 2019
N2 - Background-—Translocation of miR-181c into cardiac mitochondria downregulates the mitochondrial gene, mt-COX1. miR-181c/d-/- hearts experience less oxidative stress during ischemia/reperfusion (I/R) and are protected against I/R injury. Additionally, miR-181c overexpression can increase mitochondrial matrix Ca2+ ([Ca2+]m), but the mechanism by which miR-181c regulates [Ca2+]m is unknown. Methods and Results-—By RNA sequencing and analysis, here we show that hearts from miR-181c/d-/- mice overexpress nuclear-encoded Ca2+ regulatory and metabolic pathway genes, suggesting that alterations in miR-181c and mt-COX1 perturb mitochondria-to-nucleus retrograde signaling and [Ca2+]m regulation. Quantitative polymerase chain reaction validation of transcription factors that are known to initiate retrograde signaling revealed significantly higher Sp1 (specificity protein) expression in the miR-181c/d-/- hearts. Furthermore, an association of Sp1 with the promoter region of MICU1 was confirmed by chromatin immunoprecipitation-quantitative polymerase chain reaction and higher expression of MICU1 was found in the miR-181c/d-/- hearts. Conversely, downregulation of Sp1 by small interfering RNA decreased MICU1 expression in neonatal mouse ventricular myocytes. Changes in PDH activity provided evidence for a change in [Ca2+]m via the miR-181c/MICU1 axis. Moreover, this mechanism was implicated in the pathology of I/R injury. When MICU1 was knocked down in the miR-181c/d-/- heart by lentiviral expression of a short-hairpin RNA against MICU1, cardioprotective effects against I/R injury were abrogated. Furthermore, using an in vitro I/R model in miR-181c/d-/- neonatal mouse ventricular myocytes, we confirmed the contribution of both Sp1 and MICU1 in ischemic injury. Conclusions-—miR-181c regulates mt-COX1, which in turn regulates MICU1 expression through the Sp1-mediated mitochondriato-nucleus retrograde pathway. Loss of miR-181c can protect the heart from I/R injury by modulating [Ca2+]m through the upregulation of MICU1.
AB - Background-—Translocation of miR-181c into cardiac mitochondria downregulates the mitochondrial gene, mt-COX1. miR-181c/d-/- hearts experience less oxidative stress during ischemia/reperfusion (I/R) and are protected against I/R injury. Additionally, miR-181c overexpression can increase mitochondrial matrix Ca2+ ([Ca2+]m), but the mechanism by which miR-181c regulates [Ca2+]m is unknown. Methods and Results-—By RNA sequencing and analysis, here we show that hearts from miR-181c/d-/- mice overexpress nuclear-encoded Ca2+ regulatory and metabolic pathway genes, suggesting that alterations in miR-181c and mt-COX1 perturb mitochondria-to-nucleus retrograde signaling and [Ca2+]m regulation. Quantitative polymerase chain reaction validation of transcription factors that are known to initiate retrograde signaling revealed significantly higher Sp1 (specificity protein) expression in the miR-181c/d-/- hearts. Furthermore, an association of Sp1 with the promoter region of MICU1 was confirmed by chromatin immunoprecipitation-quantitative polymerase chain reaction and higher expression of MICU1 was found in the miR-181c/d-/- hearts. Conversely, downregulation of Sp1 by small interfering RNA decreased MICU1 expression in neonatal mouse ventricular myocytes. Changes in PDH activity provided evidence for a change in [Ca2+]m via the miR-181c/MICU1 axis. Moreover, this mechanism was implicated in the pathology of I/R injury. When MICU1 was knocked down in the miR-181c/d-/- heart by lentiviral expression of a short-hairpin RNA against MICU1, cardioprotective effects against I/R injury were abrogated. Furthermore, using an in vitro I/R model in miR-181c/d-/- neonatal mouse ventricular myocytes, we confirmed the contribution of both Sp1 and MICU1 in ischemic injury. Conclusions-—miR-181c regulates mt-COX1, which in turn regulates MICU1 expression through the Sp1-mediated mitochondriato-nucleus retrograde pathway. Loss of miR-181c can protect the heart from I/R injury by modulating [Ca2+]m through the upregulation of MICU1.
KW - Heart failure
KW - MiRNA
KW - MicroRNA
KW - Mitochondria
KW - Mitochondrial calcium
KW - MitomiR
UR - http://www.scopus.com/inward/record.url?scp=85076049791&partnerID=8YFLogxK
U2 - 10.1161/JAHA.119.012919
DO - 10.1161/JAHA.119.012919
M3 - Article
C2 - 31801413
AN - SCOPUS:85076049791
SN - 2047-9980
VL - 8
JO - Journal of the American Heart Association
JF - Journal of the American Heart Association
IS - 24
M1 - e012919
ER -