Related Experiment Video
Updated: Sep 15, 2025
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Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes
Published on: September 18, 2017
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Mitochondrial Calcium Uniporter Regulates Metabolic Remodeling and Smooth Muscle Cell Proliferation in Type 2
Olha M Koval1, Emily K Nguyen1, Dylan J Mittauer1
1Abboud Cardiovascular Research Center, Division of Cardiovascular Medicine, Department of Internal Medicine, Carver College of Medicine University of Iowa Iowa City IA USA.
Journal of the American Heart Association
|July 17, 2025
Summary
Mitochondrial dysfunction in type 2 diabetes (T2D) drives vascular smooth muscle cell (VSMC) proliferation. Inhibiting the mitochondrial calcium uniporter (MCU) complex normalizes VSMC proliferation and reduces restenosis, highlighting MCU as a therapeutic target.
Area of Science:
- Cardiovascular Biology
- Mitochondrial Physiology
- Diabetes Complications
Background:
- Type 2 diabetes (T2D) exacerbates atherosclerosis and restenosis risk due to excessive vascular smooth muscle cell (VSMC) proliferation.
- Mitochondrial dysfunction, characterized by increased reactive oxygen species (ROS) and intracellular calcium ([Ca2+]), contributes to VSMC proliferation in T2D.
- The mitochondrial calcium uniporter (MCU) complex regulates calcium influx and is implicated in T2D-associated cellular changes.
Purpose of the Study:
- To investigate the role of mitochondrial dysfunction in T2D-driven VSMC proliferation.
- To determine if and how the MCU complex mediates increased ROS and [Ca2+] in T2D VSMCs.
- To explore MCU as a potential therapeutic target for T2D-related vascular complications.
Main Methods:
- Utilized a mouse model of T2D induced by high-fat diet and streptozotocin.
- Performed in vivo phenotyping post-mechanical injury and in vitro studies on cultured VSMCs.
- Investigated VSMC-specific inhibition of mitochondrial Ca2+/calmodulin-dependent kinase II (mtCaMKII), a regulator of MCU-mediated calcium entry.
Main Results:
- Inhibition of MCU in T2D VSMCs reduced neointima formation and in vitro proliferation.
- T2D VSMCs exhibited altered MCU complex composition (loss of MICU1) and activity, with elevated mitochondrial ROS and blunted respiration.
- MCU or MICU1 inhibition normalized ROS levels, preserved mitochondrial function, reduced G6PD activity, and normalized VSMC proliferation.
Conclusions:
- Mitochondrial calcium uniporter (MCU) complex remodeling in T2D drives neointimal restenosis.
- The MCU complex regulates a T2D-induced metabolic switch promoting VSMC proliferation.
- Targeting the MCU complex presents a promising therapeutic strategy for T2D-related vascular restenosis.
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