Mitochondrial Dynamics, Diabetes, and Cardiovascular Disease

Mitochondria are multifaceted organelles that possess a complex metabolic machinery that mediates the conversion of multiple metabolic substrates to ATP, thereby providing energy for most cellular functions. In addition to their essential role in metabolism, mitochondria also regulate cell death pathways, buffer intracellular calcium, and serve as signaling hubs in the cell. Thus, mitochondria regulate not only cellular energy production but also cell survival and signal transduction (1). Importantly, mitochondria are dynamically regulated, undergoing repeated cycles of fusion and fission, a phenomenon known as mitochondrial dynamics. This process represents a critical homeostatic mechanism for mitochondrial quality control (2). Therefore, alterations in mitochondrial dynamics occur under various physiological and pathological conditions leading to mitochondrial morphological changes to meet cellular energetic demands and to adapt to stress.

Several studies have emphasized the physiological role of mitochondrial dynamics and mitochondrial quality control and how perturbations to these processes could contribute to the pathophysiology of obesity, type 2 diabetes (T2D), and cardiovascular disease (CVD) (3,4). In this article, we will discuss seminal findings addressing the role of mitochondrial dynamics in development of insulin resistance (IR) and CVD. We also attempt to reconcile seemingly disparate findings in the literature, where in some cases disruption of mitochondrial dynamics seems to play a causal role in disease progression, whereas in other circumstances it leads to the activation of compensatory mechanisms that confer metabolic protection and resistance to diet-induced obesity (DIO) and IR. Finally, we also discuss therapeutic implications of modulating mitochondrial dynamics proteins for treatment of metabolic disorders and CVD.

IR is associated with dysfunctional mitochondria, characterized by reduced bioenergetic responses to insulin stimulation and decreased mitochondrial biogenesis. The mechanisms involved in this phenomenon include transcriptional repression of mitochondrial genes, lipotoxicity, glucotoxicity, and direct effects of IR (5). It is widely accepted that once mitochondrial dysfunction ensues, it can lead to additional defects such as overproduction of reactive oxygen species (ROS), impaired fatty acid oxidation, and reduced energy expenditure, thereby aggravating IR (5). Results of recent studies suggest that perturbations in mitochondrial dynamics in insulin-responsive tissues such as skeletal muscle (6,7) and adipose tissue (8,9) may contribute to the pathophysiology of IR.

Mitochondrial dynamics is a highly regulated process (10,11). Briefly, several dynamin-related GTPases constitute the core machinery of mitochondrial fusion/fission processes (3). Mitofusin (MFN)1 and MFN2 are responsible for outer mitochondrial membrane (OMM) fusion (12,13), whereas optic atrophy 1 (OPA1) protein, which is also involved in maintenance of the mitochondrial cristae structure, regulates fusion on the inner mitochondrial membrane. Mitochondrial fission is regulated by a different set of proteins that includes dynamin-related protein 1 (DRP1) and fission protein 1 (FIS1). Other OMM proteins that mediate the recruitment of DRP1 are mitochondrial fission factor (MFF) and the mitochondrial dynamic proteins of 49 (MiD49) and 51 kDa (MiD51), the latter two being sufficient to mediate fission in the absence of FIS1 and MFF (2,14) (Fig. 1). Mitochondrial dynamics can be further modulated via posttranslational modifications of its regulatory proteins (3,15–18). Generally, while mitochondrial fusion is believed to play an important role in mitochondrial biogenesis and provides a mechanism by which mitochondrial DNA can be exchanged to maintain the mitochondrial genomes, mitochondrial fission represents an important mechanism for removal of damaged mitochondria by mitophagy (14).

Patients with diabetes have more fragmented mitochondria in skeletal muscle, compared with healthy individuals (19). Indeed, hyperglycemia results in mitochondrial fragmentation in various tissues such as heart, liver, and pancreas (19,20). It is generally believed that caloric excess promotes mitochondrial fission via mechanisms that may involve DRP1-mediated fission or impaired mitochondrial fusion. If not resolved, persistent mitochondrial fragmentation exacerbates ROS production and impairs insulin signaling. Therefore, alterations in mitochondrial dynamics can contribute to oxidative stress, mitochondrial dysfunction, and metabolic alterations, ultimately promoting the development of IR and T2D (1) (Fig. 2).

Several studies have investigated changes in expression levels of mitochondrial dynamics proteins in animal models and in humans with obesity and IR. Studies of MFN2 revealed reduced mRNA and protein levels in skeletal muscles of Zucker fatty rats and in humans with T2D (21). Furthermore, decreased MFN2 levels correlate with skeletal muscle IR, while increased MFN2 levels are observed following bariatric surgery–induced weight loss (12). OPA1 protein expression has also been shown to be reduced in skeletal muscle from individuals with obesity and in T2D (21). Moreover, there have been multiple reports of decreased fusion proteins and increased expression of fission proteins in rodent models of DIO (22–24). In response to DIO, OPA1 levels are induced in brown adipose tissue (BAT) (9), while studies in humans revealed that Opa1 mRNA levels are reduced in adipocytes of subjects with obesity (25). The rhomboid protease presenilin associated rhomboid like (PARL) is reduced in obese animals and in humans with T2D. PARL was initially discovered as an OPA1 protease, but it also regulates Opa1 and Mfn2 gene expression (26). Furthermore, reduced levels of PARL, OPA1, and MFN2 have been described in humans with IR and in obese primates (2).

Interventions in human subjects with obesity also suggest a link between mitochondrial dynamics and IR (27). A study showed increased Opa1 and Mfn2 gene expression in skeletal muscle after a 12-week aerobic exercise intervention in individuals with overweight or obesity. Meanwhile, DRP1 phosphorylation at Ser⁶¹⁶, which promotes fission, was reduced and associated with improvements in insulin sensitivity and fat oxidation (28). Furthermore, exercise reversed the diet-induced reduction in MFN2 and OPA1 levels in skeletal muscle of mice (29). Interestingly, in a recent study using Caenorhabditis elegans as a model organism, results showed that a single exercise session induces a cycle of mitochondrial fragmentation followed by fusion after a recovery period and that daily exercise sessions delay the mitochondrial fragmentation and physical fitness decline that occur with aging. Mechanistically, this study suggests that exercise may enhance muscle function through AMPK regulation of mitochondrial dynamics (30). These studies underscore the complex interactions among mitochondrial dynamics, metabolic homeostasis, and IR but leave unresolved a precise understanding of the tissue-specific role of these various mitochondrial dynamics proteins in the regulation of insulin sensitivity in vivo.

Additional insight has been gained from germline and conditional mouse mutants generated for several of the proteins regulating mitochondrial dynamics (4). In general, disruption of either mitochondrial fusion or mitochondrial fission is detrimental for mitochondrial well-being, indicating that a healthy balance between fusion and fission is necessary for maintaining cellular and mitochondrial homeostasis (4,21,31). Knockout of MFN2 in liver (13) or in muscle/heart/brain significantly disrupts metabolic homeostasis, causing IR likely due to increased endoplasmic reticulum (ER) stress or oxidative stress, with no major changes in body weight (13). These alterations occurred in parallel with defective mitochondrial respiratory rates and increased ROS, while ATP synthesis was maintained, suggesting that, mechanistically, MFN2 deficiency in skeletal muscle results in metabolic derangements mainly through inducing oxidative stress rather than affecting mitochondrial bioenergetics. Conversely, MFN1 deletion in liver led to a dramatically fragmented mitochondrial network and enhanced lipid droplet size but was associated with a greater preference for lipid use as energy substrate and increased hepatic mitochondrial function. These adaptations led to protection against high-fat diet (HFD)-induced glucose intolerance and IR, despite no major changes in body weight gain (32). Similarly, DRP1 liver knockout mice had decreased fat mass and were protected from DIO, while markers of ER stress were highly elevated. Furthermore, expression of fibroblast growth factor 21 (FGF21) was increased via induction of activating transcription factor 4 (ATF4), a master regulator of the integrated stress response (ISR). Thus, disruption of mitochondrial fission in the liver caused activation of ER stress and induced ATF4-mediated FGF21 expression to increase energy expenditure and promote resistance to DIO (24). Together, these findings reveal that the deletion of different mitochondrial dynamics proteins may lead to divergent effects on mitochondrial morphology and liver metabolism and raise the possibility that selectively targeting MFN1 or DRP1 could ameliorate IR and T2D.

In β-cells, double deletion of Mfn1/2 causes elevated fed and fasted glycemia and a dramatic decrease in plasma insulin. In contrast, oral glucose tolerance is only modestly affected in this model, and glucagon-like peptide 1 or glucose-dependent insulinotropic peptide receptor agonists largely corrected defective glucose-stimulated insulin secretion (GSIS). These data reveal that mitochondrial dynamics are essential in the β-cells to maintain normal glucose levels, but not incretin sensing, and expand our understanding of the role of mitochondrial dynamics in β-cell homeostasis and in development of diabetes (33). Indeed, a recent study expands on the underlying mechanisms of β-cell dysfunction in the context of Mfn1/2 deletion. Overall, combined Mfn1/2 deletion in β-cells leads to reduced mtDNA content, impairs mitochondrial morphology and networking, and decreases respiratory function. This ultimately results in impaired GSIS and severe glucose intolerance, which could be ameliorated by overexpressing the mitochondrial transcription factor TFAM (34). Regarding DRP1, mice with β-cell–specific Drp1 deletion are glucose intolerant due to impaired GSIS but do not develop fasting hyperglycemia as adults. Despite markedly abnormal mitochondrial morphology, islets deficient for DRP1 exhibited normal oxygen consumption rates and an unchanged glucose threshold for intracellular calcium mobilization. Instead, they revealed impaired second-phase insulin secretion and glucose-stimulated amplification of insulin secretion (35). In contrast, Drp1 overexpression slightly improves the triggering mechanism of insulin secretion in Drp1 knockdown cells and has no adverse effect on mitochondrial metabolism in wild-type cells. However, the constitutive expression of Drp1 unexpectedly impairs insulin content, which leads to a reduction in the absolute values of secreted insulin (36). Collectively, these findings confirm the important role of DRP1 for insulin secretion, but reveal off-target effects of Drp1 overexpression on insulin content that warrant caution when manipulating this protein in disease therapy.

Whole-body deletion of the mitochondrial protease OMA1, which regulates OPA1 cleavage, leads to obesity, hyperleptinemia, and liver steatosis following high-fat feeding, but unexpectedly, does not exacerbate diet-induced IR (37). Moreover, short-term insulin treatment transiently increases mitochondrial metabolism in cardiac and skeletal muscle via increased OPA1 expression in vivo and in vitro promoting mitochondrial fusion (38). Thus, mitochondrial fusion represents an acute action of insulin that seems essential for its short-term metabolic effects, and therefore, OPA1 deletion in muscle might precipitate IR. Indeed, OPA1 deficiency in skeletal muscle in vivo impaired mitochondrial cristae morphology and bioenergetics. However, surprisingly, mice in which partial inducible skeletal muscle OPA1 deficiency was induced at an early age were resistant to aging- and HFD-associated IR. This phenotype was mediated by ER stress–dependent secretion of fibroblast growth factor 21 (FGF21) as a myokine. Noteworthy, inducible reduction of OPA1 in skeletal muscle of mice fed HFD led to a dramatic reversal in obesity and diabetes (6). Thus, like Drp1 deletion in liver, OPA1 deficiency in skeletal muscle induces a hormetic response that maintains whole-body insulin sensitivity during metabolic stress (Fig. 3). In contrast, complete deletion of OPA1 in skeletal muscle either inducibly (39) or constitutively in older animals (40) leads to exacerbated ER stress, severe muscle atrophy, inflammation, and ultimately death. These studies reveal important roles for OPA1 in overall muscle health and underscore that fine tuning of mitochondrial dynamics proteins may be required to yield beneficial metabolic effects. They also support the notion that skeletal muscle could be harnessed as a potential endogenous source of FGF21, if a mechanistic target is identified that can be safely manipulated by pharmacological means (6).

Obesity in rodents and humans is associated with reduced expression of MFN2 in white and brown adipocytes, suggesting that mitochondrial dynamics plays a role in the regulation of adipose tissue function (41). Indeed, adipocyte-specific knockdown of Mfn2 in adult mice exacerbates adiposity, due in part to increased adipocyte proliferation and adipogenesis, while impairing glucose homeostasis (41). In contrast, mice constitutively lacking Mfn2 in adipocytes had similar body weight and body composition after 8 weeks of HFD, although epididymal adipose tissue mass was increased due to higher expandability. Interestingly, these mice had improved glucose tolerance and insulin sensitivity relative to wild-type mice, on the account of increased glycolytic rates in MFN2-deficient BAT (42). Selective Mfn2 deletion in BAT also conferred resistance from DIO and IR by mechanisms that involved a sex-specific remodeling of BAT mitochondria (43). Finally, although Mfn2 deletion resulted in impaired BAT thermogenesis (42,43), Mfn1 deletion in adipocytes did not affect BAT thermogenic capacity (42), suggesting that mechanisms additional to changes in mitochondrial dynamics underlie the thermogenic defects in Mfn2-deficient BAT, including communication between mitochondria and lipid droplets and potentially other organelles.

Selective deletion of OPA1 in BAT also impairs fatty acid oxidation and thermogenic activation but induces compensatory browning of white adipose tissue (WAT), thereby improving thermoregulation and systemic metabolic health. These metabolic adaptations were regulated, at least in part, via ATF4-mediated induction of FGF21 as a batokine (9). In contrast, OPA1 deletion in both BAT and WAT impairs adipose tissue expansion and lipid synthesis and mobilization. OPA1 deficiency in white adipocytes resulted in adipocyte senescence, adipose tissue inflammation, hepatic steatosis, and impaired glucose homeostasis (8). Importantly, results of a recent study showed that mild induction of OPA1 levels increases adipose tissue expandability in response to HFD, thereby improving glucose homeostasis in mice (25), suggesting that OPA1 is crucial for adipose tissue function and expandability in response to caloric excess (Fig. 3). These studies unravel contrasting roles for OPA1 and MFN2 in lipid metabolism, adipose tissue expandability, and metabolic regulation. While enhanced adipocyte expandability in Mfn2-deficient mice was associated with improved systemic glucose homeostasis in obesity, OPA1 deletion impaired glucose homeostasis by preventing adipocyte expandability.

Recently, OPA1 was also shown to play a key role in regulation of cold-induced browning of WAT, which was attenuated by OPA1 deficiency (8), while its overexpression promoted browning (25). The mitochondrial fission protein DRP1 is also required for browning of human white adipocytes (44), and to amplify BAT thermogenesis (45). Accordingly, DRP1 deficiency in adipose tissue of mice impairs lipolysis and reduces whole-body energy expenditure (46). Thus, mitochondrial dynamics is essential for brown and beige adipose tissue–mediated thermogenesis. Taken together, the results of these studies demonstrate that in IR states mitochondrial dynamics is affected, favoring a more fragmented phenotype, thereby contributing to exacerbation of IR. Furthermore, disruption of mitochondrial dynamics proteins in metabolic tissues may contribute to development of IR and other metabolic disorders. Conversely, adaptative pathways such as the ISR may be induced in response to changes in mitochondrial dynamics in various tissues, attenuating obesity and IR, and promoting overall systemic metabolic protection (Fig. 3).

Although studies in mutant mice have suggested that mitochondrial dynamics play an important role in mitochondrial quality control, energy metabolism and IR, less is known about the impact of environmental or hemodynamic stress on the regulation of mitochondrial dynamics in the heart (1). Mitochondria comprise 25–30% of the total cell volume in the heart (47). Not unexpectedly, dysfunction in mitochondria has been revealed to play multiple pathogenic roles in the development of heart failure (HF) and other CVDs (11). Dysfunctional mitochondria limit energy production, promote ROS generation, promulgate apoptotic signals, and decrease mtDNA content, thereby affecting cell survival and fate (48). Hence, maintenance of mitochondrial function and integrity is crucial for proper cardiac structure and function both at baseline and under stress conditions (11).

Several studies suggest that alterations in mitochondrial dynamics in the heart are relevant to various aspects of cardiac biology, including cardiac development (49), responses to ischemia/reperfusion (I/R) injury (50), cardiomyopathy (51), and vascular diseases (52). Indeed, mitochondrial dynamics changes remarkably in the heart following cardiac stress or injury. I/R injury promotes DRP1 translocation to the OMM, causing excessive fission (50). In mice, HFD-induced hyperlipidemia and hyperglycemia activate DRP1 phosphorylation leading to mitochondrial fission, thereby promoting myocardial IR, contractile dysfunction, and cardiomyocyte death (53). Furthermore, patients with diabetic cardiomyopathy have decreased length of the interfibrillar mitochondria in the heart, which is associated with a reduction in Mfn1 expression levels (51,54).

T2D is associated with many changes in myocardial metabolism and mitochondrial function, including an increase in fatty acid utilization, and increased mitochondrial ROS generation (55). Recently, results of a study using a mouse model with low-level overexpression of the enzyme acyl CoA synthetase (ACStg) showed that lipid overload results in increased ROS, decreased phosphorylation of DRP1 on Ser⁶³⁷, and impaired proteolytic cleavage of OPA1, resulting in remodeling of the mitochondrial network (56). Taken together, results of this study revealed that lipid excess modifies signaling pathways that regulate mitochondrial dynamics in the heart. Similarly, hyperglycemia, a hallmark of diabetes, suppresses the expression Opa1 and Mfn1 in cardiomyocytes, while increasing the expression of Drp1 to regulate fission (51). Therefore, changes in mitochondrial dynamics may contribute to diabetic cardiomyopathy.

Endothelial dysfunction, which is associated with development of atherosclerosis, is characterized by increased ROS production, leading to lipid peroxidation, mtDNA damage, and changes in mitochondrial dynamics. Damaged mtDNA, which has been shown to play a regulatory role in mitochondrial dynamics either through inducing OPA1 or through inhibiting DRP1, is an early event in atherosclerosis, and it may contribute to disease progression (57,58). Vascular smooth muscle cells proliferation and migration contribute to pathological hypertrophy of the arterial wall. Changes in the gene expression and regulation of Drp1, Mfn1, Mfn2, and Opa1 have been shown to regulate the proliferation and migration of vascular smooth muscle cells in rodent models of atherosclerosis (52,59). Together, these studies suggest that both the induction of mitochondrial fission and the reduction in mitochondrial fusion are hallmark features of CVD and might contribute to the pathophysiology of HF, diabetic cardiomyopathy, and atherosclerosis (Fig. 4).

Indeed, studies in transgenic mouse models revealed that deletion or reduced expression of mitochondrial dynamics–related genes can cause HF in vivo (Table 1). Disruption of mitochondrial fusion through targeting MFN1 and MFN2 leads to eccentric cardiac remodeling and early mortality, whereas loss of DRP1 precipitates dilated HF (60). Intriguingly, when both mitochondrial fusion and fission were conditionally inhibited in the heart through deleting MFN1/2 and DRP1 simultaneously, although these animals survived longer than animals with disruption of fission or fusion pathways, respectively, they manifested a phenotype of accelerated myocardial senescence on the basis of impaired mitochondrial quality control (60). Constitutive combined deletion of Mfn1 and Mfn2 in cardiomyocytes leads to embryonic lethality, whereas inducible deletion in adult hearts leads to mitochondria fragmentation and impaired respiration, leading to dilation and HF (49). In an independent study, inducible deletion of Mfn2 and Mfn1 in the heart of 4- to 6-week-old mice resulted in fragmented mitochondria, decreased mitochondrial respiratory function, and impaired myocardial contractile function. However, these mice were protected against acute myocardial infarction due to impaired mitochondria/sarcoplasmic reticulum tethering (61). Cardiac-specific knockout of DRP1 showed exacerbated cardiac dysfunction following pressure overload hypertrophy and I/R injury (62) due to impaired mitophagy (62,63).

Regarding OPA1, cardiac-specific ablation of the i-AAA protease YME1L1, which converts long OPA1 forms (L-OPA1) into short forms (S-OPA1) in mice, activated OMA1-triggered mitochondrial fragmentation and altered cardiac metabolism. These changes ultimately lead to dilated cardiomyopathy and HF, which was rescued by OMA1 deletion that prevented OPA1 cleavage. Intriguingly, HFD feeding or skeletal muscle deletion of YME1L1, both of which increased the availability of fatty acid substrates to the heart, rescued the lethal phenotype of these animals. This study suggested that unprocessed OPA1 is sufficient to maintain heart function and revealed a close link between mitochondrial morphology and cardiac metabolism and cross talk between skeletal muscle mitochondrial dynamics and cardiac function (64). Partial deficiency of OPA1 in cardiomyocytes leads to increased infarct size in mice exposed to I/R (65), whereas mild OPA1 overexpression conferred protection against ischemic damage in mouse hearts (66). Consistently, increasing fusion by DRP1 haploinsufficiency was associated with protection against I/R injury via increases in the expression of autophagic markers (67). Taken together, these studies reveal critical roles for mitochondrial dynamics in cardiac pathophysiology. Baseline mitochondrial dynamics is essential for long-term mitochondrial quality control, but shifting mitochondria toward increased fusion might confer cardioprotection in response to hemodynamic stress.

Maintaining an optimal balance between mitochondrial fusion and fission is essential for the regulation of metabolic and cardiovascular homeostasis. Given the potential role of mitochondrial dynamics in the pathophysiology of metabolic diseases, pharmacological approaches targeting mitochondrial dynamics proteins could be purposed to treat these conditions. Indeed, as previously reviewed (68), several compounds such as mdivi-1, P110, dynasore, and S3 are candidates for reducing excessive mitochondrial fragmentation through interfering with DRP1 function or through inhibiting MFN1/2 degradation and therefore, could be of interest for the treatment of metabolic disorders. However, the side effects of long-term treatment with such compounds should be taken into consideration, as some have been associated with detrimental effects such as cell death and reduced mitochondrial mass (68,69). Moreover, differential tissue-specific responses to altered mitochondrial dynamics could have complex effects when systemically manipulated. While the outcome and efficacy of chemical compounds inducing mitochondrial fusion remain to be elucidated, the compounds listed above provide tools that can be explored for therapeutic application to diseases associated with changes in mitochondrial dynamics (69).

Pharmacological or exercise-induced regulation of mitochondrial dynamics also holds therapeutic potential for CVD. Current evidence suggests that the promotion of fusion and/or inhibition of fission may improve and reduce I/R-related heart injury (70). Aerobic training and treatment with cordycepin induce the expression of fusion-related proteins and reduce infarct size (71,72). Similarly, treatment with hydralazine decreases infarct size in part through the inactivation of DRP1 (73). In the context of diabetic cardiomyopathy, Orai1-mediated inhibition of Ca²⁺ influx into the mitochondria suppresses DRP1-mediated fission during hyperglycemia (51).

Several new-class antihyperglycemic drugs, such as glucagon-like peptide 1 receptor agonists and sodium–glucose cotransporter 2 inhibitors (SGLT2i), can improve cardiovascular health beyond their ability to control glycemia and body weight (74). Although the mechanisms are still incompletely understood, studies have shown that both glucagon-like peptide 1 receptor agonists and SGLT2i may act through increasing the protein levels of MFN2 and OPA1, while reducing DRP1 levels in cardiomyocytes in models of cardiac stress (75,76). These changes in mitochondrial dynamics seem to correlate with reduced oxidative stress and ER stress (74). Furthermore, in a model of diabetic cardiomyopathy, SGLT2i increased mitochondrial respirations and the protein expression levels of the mitochondrial dynamics proteins DRP1, MFN1, and OPA1. The results of this study suggest that SGLT2i might attenuate the defects in mitochondrial function in diabetic cardiomyopathy by modulating mitochondrial dynamics (77). Further studies should focus on the requirement of different mitochondrial dynamics proteins for the improvements observed in the metabolic profile as well as in the cardiac phenotypes upon treatment with these drugs.

As various approaches continue to be developed and tested for the treatment of conditions associated with impaired mitochondrial dynamics, important consideration should be given to the tissue-specific effects of modulating mitochondrial dynamics proteins. As mentioned above, alterations in these proteins may lead to activation of compensatory mechanisms, including elevated ER stress and activation of the ISR, which may result in improved metabolic health (Fig. 3) or, if unresolved, may aggravate pathology. Therefore, considering the mitochondrial dynamics protein primarily affected by the treatment, the main target tissue, and the degree of potential mitochondrial stress will be crucial for development of effective and safe therapies. Additionally, studies focusing on elucidating the mechanistic links between changes in mitochondrial dynamics and activation of stress response pathways will be important to define additional regulatory components that may be leveraged for therapeutic purposes. Lastly, finely tuned, tissue-specific approaches to modulate mitochondrial dynamics using new technologies, such as aptamers (78), could be of interest to test the role of various mitochondrial dynamics proteins in preclinical models of diabetes and CVD.

Funding. This work was supported by National Institutes of Health (NIH) grant DK125405 to R.O.P., NIH grants HL127764 and HL112413, American Heart Association (AHA) grant 20SFRN35120123 and the Teresa Benoit Diabetes research fund to E.D.A. (who is an established investigator of the AHA), and NIH grant 1R25GM116686 to L.M.G.-P.

Duality of Interest. No potential conflicts of interest relevant to this article were reported.

Prior Presentation. Parts of this study were presented at the 83rd Scientific Sessions of the American Diabetes Association, San Diego, CA, 23–26 June 2023.