Decreased Expression of Mitochondrial Calcium Uptake Protein 1 Leads to Skeletal Muscle Dysfunction in Septic Mice

LI Xue-xin , WU Song-lin, GUAN Fa-sheng, LIU Li

Abstract

To observe the effect of sepsis on skeletal muscle function and to explore the role of skeletal muscle mitochondrial calcium uptake protein 1 (MICU1).   Methods  A total of 40 specific-pathogen-free (SPF) healthy male C57BL/6J mice were randomly assigned to 4 groups, a sham operation group (Sham group, n=8), a sepsis modeling 6 h group (cecal ligation and puncture [CLP]-6 h group, n=10), a sepsis modeling 12 h group (CLP-12 h group, n=10), and a sepsis modeling 24 h group (CLP-24 h, n=12). The sepsis model was established by CLP. Mice in the Sham group only underwent laparotomic exploration of the cecum. Another 20 SPF mice were selected. The tibialis anterior muscle on one side was empty-transfected with adeno-associated virus (AAV) as controls (AAV-C), and the tibialis anterior muscle on the other side was transfected with AAV to enhance MICU1 expression (AAV-M). The mice were randomly assigned to two groups, a sham operation group (AAV-C-Sham and AAV-M-Sham, n=8) and a sepsis model 24 h group (AAV-C-CLP and AAV-M-CLP, n=12). The grip strength and compound muscle action potential (CMAP) of the tibialis anterior muscle were measured in each group at the corresponding time points. The levels of inflammatory factors, including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), in the skeletal muscle were measured by ELISA. The morphological changes of skeletal muscle cells were observed through H&E staining. The expression levels of MICU1 and muscle atrophy-related proteins, including muscle RING-finger containing protein 1 (MuRF1) and muscle atrophy Fbox protein (MAFbx), were determined by Western blot. The expression levels of MICU1 mRNA in skeletal muscle were determined by RT-qPCR.  Results  Compared with mice in the Sham group, mice in the CLP group showed decreased body weight (P<0.05); their grip strength decreased with the prolongation of CLP modeling time (P<0.05); the amplitude of CMAP decreased, showing prolonged duration and latency (P<0.05); the expression levels of inflammatory factors, including TNF-α and IL-6, in skeletal muscle increased gradually (P<0.05); the fiber diameter and cross-sectional area of skeletal muscle decreased gradually with the prolongation of modeling time (P<0.05); the protein expression levels of MuRF1and MAFbx proteins increased gradually (P<0.05); the expression levels of MICU1 protein and mRNA decreased gradually (P<0.05). There was no significant difference in all indices between AAV-M-Sham and AAV-C-Sham groups (P>0.05). Compared with mice in the AAV-C-CLP group, mice in the AAV-M-CLP group showed increased grip strength (P<0.05); the amplitude of CMAP increased, showing shortened duration and latency (P<0.05); the fiber diameter and cross-sectional area of skeletal muscle increased (P<0.05); the expression levels of MuRF1and MAFbx decreased (P<0.05).   Conclusion  Sepsis leads to skeletal muscle dysfunction, which is related to the decrease in mitochondrial MICU1 expression.

 

Keywords: Sepsis, Skeletal muscles, Muscle weakness, Mitochondria, Mitochondrial calcium uptake protein 1

 

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References


HABERECHT-MÜLLER S， KRÜGER E， FIELITZ J. Out of control: the role of the ubiquitin proteasome system in skeletal muscle during inflammation. Biomolecules，2021，11(9): 1327. doi: 10.3390/biom11091327.

VANKRUNKELSVEN W， DERDE S， GUNST J， et al. Obesity attenuates inflammation, protein catabolism, dyslipidaemia, and muscle weakness during sepsis, independent of leptin. J Cachexia Sarcopenia Muscle，2022，13(1): 418–433. doi: 10.1002/jcsm.12904.

WITTEVEEN E， WIESKE L， MANDERS E， et al . Muscle weakness in a S. pneumoniae sepsis mouse model. Ann Transl Med，2019，7(1): 9. doi: 10.21037/atm.2018.12.45.

SCHEFOLD J C， WOLLERSHEIM T， GRUNOW J J， et al. Muscular weakness and muscle wasting in the critically ill. J Cachexia Sarcopenia Muscle，2020，11(6): 1399–1412. doi: 10.1002/jcsm.12620.

VECELLIO REANE D， CERQUA C， SACCONI S， et al. The splicing of the mitochondrial calcium uniporter genuine activator MICU1 is driven by RBFOX2 splicing factor during myogenic differentiation. Int J Mol Sci，2022，23(5): 2517. doi: 10.3390/ijms23052517.

ALEVRIADOU B R， PATEL A， NOBLE M， et al. Molecular nature and physiological role of the mitochondrial calcium uniporter channel. Am J Physiol Cell Physiol，2021，320(4): C465–C482. doi: 10.1152/ajpcell.00502. 2020.

TSAI C W， RODRIGUEZ M X， Van KEUREN A M， et al. Mechanisms and significance of tissue-specific MICU regulation of the mitochondrial calcium uniporter complex. Mol Cell，2022，82(19): 3661–3676.e8. doi: 10. 1016/j.molcel.2022.09.006.

DRECHSLER S， OSUCHOWSKI M. Cecal ligation and puncture. Sepsis: 2321. New York， NY: Springer US， 2021: 1−8.

ALVERDY J C， KESKEY R， THEWISSEN R. Can the cecal ligation and puncture model be repurposed to better inform therapy in human sepsis?Infect Immun， 2020， 88(9): e00942−19. doi: 10.1128/IAI.00942-19.

FUJINAMI Y， INOUE S， ONO Y， et al. Sepsis induces physical and mental impairments in a mouse model of post-intensive care syndrome. J Clin Med，2021，10(8): 1593. doi: 10.3390/jcm10081593.

POLLARI E， PRIOR R， ROBBERECHT W， et al. In Vivo electrophysiological measurement of compound muscle action potential from the forelimbs in mouse models of motor neuron degeneration. J Vis Exp，2018(136): 57741. doi: 10.3791/57741.

WANG J， WANG Y， XIE J， et al. Upregulated PD-L1 delays human neutrophil apoptosis and promotes lung injury in an experimental mouse model of sepsis. Blood，2021，138(9): 806–810. doi: 10.1182/blood. 2020009417.

FANG W， TSENG Y， LEE T， et al. Triptolide prevents LPS-induced skeletal muscle atrophy via inhibiting NF-κB/TNF-α and regulating protein synthesis/degradation pathway. Br J Pharmacol，2021，178(15): 2998–3016. doi: 10.1111/bph.15472.

LEDUC-GAUDET J P， MAYAKI D， REYNAUD O， et al. Parkin overexpression attenuates sepsis-induced muscle wasting. Cells，2020， 9(6): 1454. doi: 10.3390/cells9061454.

CAO Y， WANG Z， YU T， et al. Sepsis induces muscle atrophy by inhibiting proliferation and promoting apoptosis via PLK1-AKT signalling. J Cell Mol Med，2021，25(20): 9724–9739. doi: 10.1111/jcmm. 16921.

ZANDERS L， KNY M， HAHN A， et al. Sepsis induces interleukin 6, gp130/JAK2/STAT3, and muscle wasting. J Cachexia Sarcopenia Muscle， 2022，13(1): 713–727. doi: 10.1002/jcsm.12867.

WU W， ZHENG J， JIA Z. Structural characterization of the mitochondrial Ca2+ uniporter provides insights into Ca2+ uptake and regulation. iScience，2021，24(8): 102895. doi: 10.1016/j.isci.2021.102895.

FAN M， ZHANG J， TSAI C W， et al. Structure and mechanism of the mitochondrial Ca2+ uniporter holocomplex. Nature，2020，582(7810): 129–133. doi: 10.1038/s41586-020-2309-6.

ALI M， ZHANG X， LACANNA R， et al. MICU1-dependent mitochondrial calcium uptake regulates lung alveolar type 2 cell plasticity and lung regeneration. JCI Insight，2022，7(4): e154447. doi: 10.1172/jci. insight.154447.

DEBATTISTI V， HORN A， SINGH R， et al. Dysregulation of mitochondrial Ca2+ uptake and sarcolemma repair underlie muscle weakness and wasting in patients and mice lacking MICU1. Cell Rep， 2019，29(5): 1274–1286.e6. doi: 10.1016/j.celrep.2019.09.063.

SINGH R， BARTOK A， PAILLARD M， et al. Uncontrolled mitochondrial calcium uptake underlies the pathogenesis of neurodegeneration in MICU1-deficient mice and patients. Sci Adv，2022， 8(11): eabj4716. doi: 10.1126/sciadv.abj4716.

GHOSH S， ZULKIFLI M， JOSHI A， et al. MCU-complex-mediated mitochondrial calcium signaling is impaired in Barth syndrome. Hum Mol Genet，2022，31(3): 376–385. doi: 10.1093/hmg/ddab254.


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