Human diabetic heart failure (diHF) is a major contributor to cardiovascular morbidity and mortality and is characterized by myocardial lipid overload and oxidative injury; however, the specific lipid species and molecular mechanisms driving myocardial dysfunction remain unclear. To identify lipid species and integrated molecular networks underlying human diHF using an untargeted multi-omics approach. We performed integrated lipidomic, metabolomic, and proteomic profiling of human diabetic failing hearts and matched non-diabetic controls. Lipidomic and metabolomic analyses were conducted using high-resolution UPLC-MS/MS, and quantitative proteomics was performed using tandem mass tag-based LC-MS/MS. Multivariate modeling, differential abundance testing, pathway enrichment, and cross-platform network integration were used to define coordinated lipid-metabolite-protein signatures associated with diHF. Multi-omics integration identified “electrostatic lipidopathy”, a charge-dependent remodeling of membrane and metabolic lipid species, as a defining feature of diHF. Diabetic hearts exhibited enrichment of negatively charged polyunsaturated phospholipids and sphingolipids together with increased diradylglycerols, ceramides, and lactosylceramides, generating a highly anionic lipid environment consistent with increased susceptibility to lipid peroxidation and ferroptosis-related injury. Metabolomic profiling revealed disruption of the myocardial lipid-energy axis characterized by a pattern consistent with increased fatty-acid influx, acylcarnitine accumulation, incomplete β-oxidation, and metabolic inflexibility. Proteomic remodeling demonstrated coordinated suppression of oxidative phosphorylation, mitochondrial dysfunction, inflammatory activation, and extracellular matrix remodeling. Network analysis linked lipid charge remodeling with mitochondrial energetic failure, oxidative stress, and fibrotic remodeling in diHF myocardium. Electrostatic lipidopathy represents a previously unrecognized mechanism of diabetic cardiac remodeling. By linking membrane lipid charge architecture with mitochondrial dysfunction, redox imbalance, and inflammatory-fibrotic signaling, these findings highlight lipid charge imbalance and ferroptosis-related vulnerability as potential therapeutic targets in diabetic heart failure. What is currently known about this topic? Diabetic heart failure (diHF) is associated with excess cardiovascular mortality and is characterized by myocardial lipid overload, mitochondrial dysfunction, oxidative stress, and metabolic inflexibility. However, the specific lipid species and integrated molecular networks that drive diabetic cardiac remodeling in humans remain unclear. What is the key research question? What lipid species and coordinated lipid-metabolite-protein networks define human diHF, and could charge-dependent lipid remodeling represent a systems-level organizing feature of diabetic cardiac dysfunction? What is new? This study identifies electrostatic lipidopathy - a charge-dependent remodeling of membrane and metabolic lipid species - as a previously unrecognized molecular phenotype of human diHF. Integrated multi-omics analysis reveals enrichment of negatively charged lipid species, disruption of the myocardial lipid-energy axis, mitochondrial dysfunction, ferroptosis-associated signatures, and inflammatory activation, defining a coordinated lipid-metabolic-proteomic remodeling network. How might this study influence clinical practice? By reframing diabetic cardiac remodeling through the lens of membrane electrostatics and metabolic inflexibility, these findings highlight charge-defined lipid species and ferroptosis-associated pathways as potential biomarkers and therapeutic targets, supporting future studies aimed at precision risk stratification and treatment of diabetic heart failure.

Gut dysbiosis is increasingly recognized as a contributor to heart failure; however, its specific role in the development of metabolic syndrome-induced heart failure (MetS-HF) remains poorly defined. A defining feature of MetS-HF is cardiac steatosis, which drives lipotoxicity, maladaptive remodeling, and progressive cardiac dysfunction. This review integrates mechanistic and translational evidence showing how gut microbiota dysbiosis initiates and exacerbates MetS-HF by disrupting lipid homeostasis, leading to myocardial steatosis, metabolic remodeling, cardiomyocyte death, adverse structural remodeling, and impaired cardiac performance. We also highlight how gut dysbiosis promotes systemic inflammation and hypertension, further aggravating cardiac dysfunction in MetS-HF. Finally, we discuss the potential of artificial intelligence, integrative multiomics, and network-based bioinformatics to elucidate the molecular pathways linking gut dysbiosis to MetS-HF and to identify novel therapeutic targets.

The miniature (mini) Ossabaw pigs are proposed as a translational preclinical model for testing and developing novel therapeutics for human diseases, including cystic fibrosis, cancer, and metabolic syndrome (MetS). In recent years, pigs have gained similar attention for studying retinal abnormalities and disorders owing to their close resemblance in size, anatomy, vasculature, and pathology to the human eye compared with their rodent counterparts. In our previous study, Ossabaw minipigs fed a Western diet for 10 weeks and followed for 3.5 months exhibited early signs of retinal degeneration and vascular abnormalities, mimicking the early stages of diabetic retinopathy (DR). To further evaluate pathomorphological alterations across neuronal and non-neuronal cell types, the present study comprehensively investigated individual retinal layers using cell-type-specific immunostaining. We found that the Western diet-fed mini pigs had reduced rhodopsin and blue opsins, changes in bipolar and ganglion cells, and reduced density of pre- and post-synaptic connections. Moreover, the retinas of obese mini pigs showed evidence of gliosis and microglial activation. Our findings suggest that a Western diet-induced metabolic disorder exhibits an early neurodegenerative milieu and further demonstrate the suitability of Ossabaw mini pigs as a model for human retinal diseases associated with MetS, such as DR and diabetic macular edema (DME).

Although the collagenase enzyme activity of matrix metalloproteinase-9 (MMP9) is well-documented, its non-enzymatic functions remain less understood. The interaction between intracellular superoxide dismutase-1 (SOD1) and MMP9 is known, with SOD1 suppressing MMP9. However, the mechanism by which MMP9, a secretory protein, influences the extracellular antioxidant superoxide dismutase-3 (SOD3) is not yet clear. To explore MMP9's regulatory impact on SOD3, we employed human embryonic kidney-293 cells, transfecting them with MMP9 overexpresssion and catalytic-site mutant plasmids. Additionally, MMP9 overexpressing cells were treated with an MMP9 activator and inhibitor. Analyses of both cell lysates and culture medium provided insights into MMP9's intracellular and extracellular regulatory roles. In-silico analysis and experimental approaches like proximal ligation assay and co-immunoprecipitation were utilized to delineate the protein-protein interactions between MMP9 and SOD3. Our findings indicate that activated MMP9 enhances SOD3 levels, a regulation not hindered by MMP9 inhibitors. Intriguingly, catalytically inactive MMP9 appeared to reduce SOD3 levels, likely due to MMP9's binding with SOD3, leading to their proteolytic degradation. This MMP9 influence on SOD3 was consistent in both intracellular and extracellular environments, suggesting a parallel in MMP9-SOD3 interactions across these domains. Ultimately, this study unveils a novel interaction between MMP9 and SOD3, highlighting the unique regulatory role of catalytically inactive MMP9 in diminishing SOD3 levels, contrasting its usual upregulation by active MMP9.

Gene therapy has a pivotal role in treating new diseases. In addition to the recent mRNA-based COVID-19 vaccines produced by Pfizer-BioNTech and Moderna against severe acute respiratory syndrome corona virus 2, several new gene therapies have recently been approved as effective treatments for fatal genetic disorders such as Duchenne’s muscular dystrophy, familial transthyretin amyloidosis, hemophilia A, hemophilia B, spinal muscle atrophy, early cerebral autoleukodystrophy, and β-thalassemia. This review provides novel insights into RNA therapeutics focusing on endogenous RNA species, RNA structure and function, and chemical modifications that improve the stability and distribution of RNAs. Furthermore, it includes updated knowledge on clinically approved gene therapies rendering a comprehensive understanding of the biochemical basis and clinical application of gene therapies. Significance Statement There have recently been significant advances in clinical translation of RNA therapeutics. This review discusses the diverse types of RNA species, RNA structure and function, backbone and chemical modifications to RNAs, and every RNA therapeutic approved for clinical use at the time of writing.

Background and Hypothesis: Metabolic Syndrome (MetS) is a leading cause of heart failure; however, the underlying mechanisms remain unclear. We hypothesized that altered metabolic flux, particularly in long-chain fatty acids (LCFA) and glucose, and impaired mitochondrial function contributes to cardiac remodeling in MetS. Methods: Isolated hearts from Insulin2 mutant Akita mice were used as a model of MetS to investigate oxidative metabolism and substrate flux. Hearts from 14-week-old male Akita mice and their normoglycemic wild-type (WT) littermates (both n = 4) were studied using Langendorff perfusion with Krebs–Henseleit buffer containing 8 mM [1,6- 13 C]glucose, 1.2 mM [2- 13 C]lactate, 0.12 mM [2- 13 C]pyruvate, and 0.3 mM [U- 13 C]LCFA. Oxygen consumption (MVO 2 ) was measured using a blood gas analyzer and used to calculate absolute metabolic fluxes. 13 C-labeling patterns allowed differentiation of substrate-specific oxidation. Glycolytic flux was quantified by analyzing the effluent perfusate with 1 H-NMR spectroscopy. Coronary flow rates and heart weight-to-body weight ratios were recorded to assess cardiac perfusion and relative heart size. Results: The metabolic flux analysis revealed a marked shift toward fatty acid metabolism in the Akita heart, as evidenced by significantly increased LCFA oxidation (0.692 ± 0.013 vs. 0.473 ± 0.024 µmol/mg; p < 0.001). In contrast, glucose oxidation was severely impaired in Akita hearts (0.072 ± 0.012 vs. 0.199 ± 0.020 µmol/mg in WT; p < 0.0001), reflecting a substantial reduction in pyruvate dehydrogenase (PDH) flux (0.98 ± 0.18 vs. 2.16 ± 0.18 µmol/min/mg; p < 0.0001). A significantly lower oxygen consumption rates (7.61 ± 0.63 vs. 9.49 ± 0.52 µmol/min/mg; p < 0.01) and diminished TCA cycle flux (2.63 ± 0.22 vs. 3.25 ± 0.18 µmol/min/mg; p < 0.05) in the Akita heart demonstrate impaired mitochondrial function. Additionally, Akita hearts exhibited reduced production of labeled lactate and alanine from glucose, indicating impaired glycolytic oxidative fluxes. Coronary flow rates remained comparable between the groups, and heart weight-to-body weight ratios showed no significant differences. Conclusion: The Akita diabetic hearts demonstrate significant metabolic inflexibility, characterized by enhanced fatty acid oxidation, suppressed glucose utilization, and impaired mitochondrial function. These findings highlight the critical metabolic shifts associated with cardiac remodeling in MetS and underscore the need for therapeutic strategies targeting substrate utilization and mitochondrial function. This research was supported by AHA Grants 23SCEFIA1154964, 24IPA1272385, 24TPA1297929 (to G.S.); and NIH Grants R56HL156806, R01HL155618, 1P50AA030407 (to P.K.M.). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Diabetes significantly increases the risk of heart failure by inducing myocardial cell death, potentially through ferroptosis—an iron-dependent, non-apoptotic cell death pathway characterized by lipid peroxidation. The role of cardiac ferroptosis in human heart failure, however, remains poorly understood. In this study, we compared cardiac ferroptosis in humans with diabetic heart failure to that in healthy controls. Our findings reveal that diabetes not only intensifies myocardial cell death but also upregulates markers of ferroptosis in human hearts. This is linked to decreased transcription and activity of glutathione peroxidase-4 (GPX4), influenced by reduced levels of activating transcription factor-4 (ATF4) and nuclear factor erythroid-2-related factor-2 (NRF2), and downregulation of glutathione reductase (GSR). Additionally, diabetic hearts showed an increased labile iron pool due to enhanced heme metabolism by heme oxygenase-1 (HMOX1), elevated iron import via divalent metal transporter-1 (DMT1), reduced iron storage through ferritin light chain (FLC), and decreased iron export via ferroportin-1 (FPN1). The reduction in FPN1 levels likely results from decreased stabilization by amyloid precursor protein (APP) and diminished NRF2-mediated transcription. Furthermore, diabetes upregulates lysophosphatidylcholine acyltransferase-3 (LPCAT3), facilitating the integration of polyunsaturated fatty acids (PUFA) into phospholipid membranes, and downregulates acyl-CoA thioesterase-1 (ACOT1), which further promotes ferroptosis. LC–MS/MS analysis identified several novel proteins implicated in diabetes-induced cardiac ferroptosis, including upregulated ceruloplasmin, which enhances iron metabolism, and cytochrome b-245 heavy chain (CYBB), a key component of NADPH oxidase that aids in the production of reactive oxygen species (ROS), along with downregulated voltage-dependent anion-selective channel protein-2 (VDAC2), essential for maintaining mitochondrial membrane potential. In conclusion, our study not only confirms the presence and potentially predominant role of cardiac ferroptosis in humans with diabetic heart failure but also elucidates its molecular mechanisms, offering potential therapeutic targets to mitigate heart failure complications in diabetic patients.

Heavy alcohol use is the leading etiology of non-ischemic dilated cardiomyopathy. Alcohol-Associated Cardiomyopathy (ACM) is a specific cardiac muscle disease which is characterized by inflammation, abnormal fatty acid metabolism, and oxidative stress. TP-R, a G-protein coupled receptor, is widely expressed in the myocardium, and plays a critical role in the pathogenesis of various cardiac diseases including hypertensive heart disease and dilated cardiomyopathy. TP-R is activated by thromboxane A2 (TXA2) and 8-isoprostane. Of note, clinical studies have shown that chronic alcohol use markedly increases the level of thromboxane B2, a stable metabolite of TXA2, in plasma of alcohol use disorder patients. However, the role of TP-R signaling in the pathogenesis of ACM remains unclear. Therefore, we hypothesize that TP-R signaling mediates adverse effects of alcohol on the myocardium. To test this hypothesis, we used the chronic plus binge ethanol feeding model. C57BL/6 wild-type male mice (8-week) were fed with Lieber-Decarli ethanol (5% v/v) diet (ET, n = 10) or isocaloric control diet (CON, n = 6) for ten days followed by single binge of ethanol or maltose-dextrin via oral gavage. A cohort of ethanol-fed mice received SQ 29,548, a TP-R antagonist (ET+SQ, n = 8). Our data indicated that mouse myocardial protein levels of thromboxane A2 synthase (TBXAS1, P <0.001), an enzyme responsible for synthesis of TXA2, was increased in response to ethanol exposure. Concomitantly, ethanol-fed mice displayed upregulated myocardial protein levels of pro-inflammatory mediators including tumor necrosis factor alpha (TNF-α, P <0.001) and secreted interleukin 1 beta (IL1β, P <0.001) compared with their controls. These adverse alterations induced by the ethanol diet were ameliorated by the pharmacological inhibition of TP-R. Interestingly, RNA-sequencing and western blotting analysis showed that expression of thioredoxin-interacting protein (TXNIP) was upregulated in response to ethanol exposure ( P <0.001). Meanwhile, mice fed with ethanol diet had the increased myocardial protein level of NLR family pyrin domain containing 3 (NLRP3, P <0.01) compared with CON mice. These ethanol-induced increases in protein levels of TXNIP ( P <0.001) and NLRP3 ( P <0.01) were attenuated due to SQ 29,548 administration. Accordingly, these findings lead us to suggest that pharmaceutical inhibiting TP-R has protective effects on attenuating ethanol-induced myocardial inflammation by inhibiting TXNIP-NLRP3-IL1β axis.

Background: The DMCM-AHEAD trial showed that lipotoxicity is a distinct feature of diabetic heart failure, which initiates and exacerbates cardiac pathogenesis in diabetic patients. Circulating iron levels are increased in diabetic patients. The combined presence of lipids and iron suggests a predominant role of ferroptosis in diabetes-induced heart failure. However, molecular targets for diabetes-induced myocardial ferroptosis remain unclear. In the T1DM heart, matrix metalloproteinase-9 (MMP9), a protease, is upregulated, and targeted deletion of MMP9 is cardioprotective. Hypothesis: Targeted deletion of MMP9 mitigates T1DM-induced myocardial ferroptosis. Methods and results: We performed in vitro studies on the loss and gain-of-function of MMP9 using human cardiomyocytes (AC16 cells). Overexpression of MMP9 downregulates (-1.55-fold p<0.001) GPX4, a key marker of ferroptosis, while inhibition of MMP9 upregulates (+2.03-fold p<0.001) GPX4 (n=6), suggesting a key role of MMP9 in GPX4 regulation and ferroptosis signaling. To determine the specific role of MMP9 in T1DM-induced ferroptosis, we evaluated ferroptosis markers in the heart (LV) tissue of male Insulin2 mutant (Ins2+/-) Akita (T1DM), littermate euglycemic Ins2+/+ WT, Akita/MMP9 knockout (MMP9KO), and MMP9KO mice (n=3-6). The cardiac levels of Acyl-CoA synthetase long-chain family member-4 (ASCL4), which initiates the formation of lipid peroxides, and divalent metal transporter-1 (DMT1), which increases redox-active iron, were upregulated in the Akita while downregulated in the Akita/MMP9KO hearts (Akita vs WT: ASCL4: +1.42-fold p<0.05, DMT1: +1.34-fold p<0.05; Akita/MMP9 vs Akita: ACSL4: -1.46-fold p<0.05, DMT1: -1.03-fold p<0.05). Furthermore, cardiac levels of Ferritin-Light Chain (FLC), which stores iron to suppress ferroptosis, was downregulated in the Akita but upregulated in the Akita/MMP9KO hearts (Akita vs WT: -2.01-fold p<0.01, Akita/MMP9 vs Akita: +1.36-fold p<0.05). These results suggest that upregulation of MMP9 promotes while inhibition of MMP9 mitigates ferroptosis in the T1DM heart. Conclusion: This is the first report to reveal MMP9 as a promising therapeutic target for T1DM-induced myocardial ferroptosis. This work was supported in part by the National Institutes of Health (NIH) Grant R56HL156806 to PKM, and University of Nebraska Medical Center (UNMC) Presidential Graduate Fellowship to FIG. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

EDITORIAL article Front. Cardiovasc. Med., 22 March 2024Sec. Cardiovascular Biologics and Regenerative Medicine Volume 11 - 2024 | https://doi.org/10.3389/fcvm.2024.1392073

Cardiovascular research relies heavily on the veracity of in vitro cardiomyocyte models, with H9c2 and HL-1 cell lines at the forefront due to their cardiomyocyte-like properties. However, the variability stemming from nonstandardized culturing and transfection methods poses a significant challenge to data uniformity and reliability. In this study, we introduce meticulously crafted protocols to enhance the culture and transfection of H9c2 and HL-1 cells, emphasizing the reduction of cytotoxic effects while improving transfection efficiency. Through the examination of polymer-based and lipid-based transfection methods, we offer a comparative analysis that underscores the heightened efficiency and reduced toxicity of these approaches. Our research provides an extensive array of step-by-step procedures designed to foster robust cell cultures and outlines troubleshooting practices to rectify issues of low transfection rates. We discuss the merits and drawbacks of both transfection techniques, equipping researchers with the knowledge to choose the most fitting method for their experimental goals. By offering a definitive guide to these cell lines' culturing and transfection, our work seeks to set a new standard in procedural consistency, ensuring that the cardiovascular research community can achieve more dependable and reproducible results, thereby pushing the boundaries of current methodologies toward impactful clinical applications. NEW & NOTEWORTHY We have developed standardized protocols that significantly reduce cytotoxicity and enhance transfection efficiency in H9c2 and HL-1 cardiomyocyte cell lines. Our detailed comparative analysis of polymer-based and lipid-based transfection methods has identified optimized approaches with superior performance. Accompanying these protocols are comprehensive troubleshooting strategies to address common issues related to low transfection rates. Implementing these protocols is expected to yield more consistent and reproducible results, driving the field of cardiovascular research toward impactful clinical breakthroughs.

Diabetes mellitus (DM) is characterized by chronic hyperglycemia, and despite intensive glycemic control, the risk of heart failure in patients with diabetes remains high. Diabetes-induced heart failure (DHF) presents a unique metabolic challenge, driven by significant alterations in cardiac substrate metabolism, including increased reliance on fatty acid oxidation, reduced glucose utilization, and impaired mitochondrial function. These metabolic alterations lead to oxidative stress, lipotoxicity, and energy deficits, contributing to the progression of heart failure. Emerging research has identified novel mechanisms involved in the metabolic remodeling of diabetic hearts, such as autophagy dysregulation, epigenetic modifications, polyamine regulation, and branched-chain amino acid (BCAA) metabolism. These processes exacerbate mitochondrial dysfunction and metabolic inflexibility, further impairing cardiac function. Therapeutic interventions targeting these pathways—such as enhancing glucose oxidation, modulating fatty acid metabolism, and optimizing ketone body utilization—show promise in restoring metabolic homeostasis and improving cardiac outcomes. This review explores the key molecular mechanisms driving metabolic remodeling in diabetic hearts, highlights advanced methodologies, and presents the latest therapeutic strategies for mitigating the progression of DHF. Understanding these emerging pathways offers new opportunities to develop targeted therapies that address the root metabolic causes of heart failure in diabetes.

Ferroptosis, defined by the suppression of glutathione peroxidase-4 (GPX4) and iron overload, is a distinctive form of regulated cell death. Our in-depth research identifies matrix metalloproteinase-9 (MMP9) as a critical modulator of ferroptosis through its influence on GPX4 and iron homeostasis. Employing an innovative MMP9 construct without collagenase activity, we reveal that active MMP9 interacts with GPX4 and glutathione reductase, reducing GPX4 expression and activity. Furthermore, MMP9 suppresses key transcription factors (SP1, CREB1, NRF2, FOXO3, and ATF4), alongside GPX1 and ferroptosis suppressor protein-1 (FSP1), thereby disrupting the cellular redox balance. MMP9 regulates iron metabolism by modulating iron import, storage, and export via a network of protein interactions. LC-MS/MS has identified 83 proteins that interact with MMP9 at subcellular levels, implicating them in ferroptosis regulation. Integrated pathway analysis (IPA) highlights MMP9's extensive influence on ferroptosis pathways, underscoring its potential as a therapeutic target in conditions with altered redox homeostasis and iron metabolism.

Differential gene expression is associated with diabetic cardiomyopathy (DMCM) and culminates in adverse remodeling in the diabetic heart. Genome editing is a technology utilized to alter endogenous genes. Genome editing also provides an option to induce cardioprotective genes or inhibit genes linked to adverse cardiac remodeling and thus has promise in ameliorating DMCM. Non-coding genes have emerged as novel regulators of cellular signaling and may serve as potential therapeutic targets for DMCM. Specifically, there is a widespread change in the gene expression of fetal cardiac genes and microRNAs, termed genetic reprogramming, that promotes pathological remodeling and contributes to heart failure in diabetes. This genetic reprogramming of both coding and non-coding genes varies with the progression and severity of DMCM. Thus, genetic editing provides a promising option to investigate the role of specific genes/non-coding RNAs in DMCM initiation and progression as well as developing therapeutics to mitigate cardiac remodeling and ameliorate DMCM. This chapter will summarize the research progress in genome editing and DMCM and provide future directions for utilizing genome editing as an approach to prevent and/or treat DMCM.

Ferroptosis is a newly identified myocardial cell death mechanism driven by iron-dependent lipid peroxidation. The presence of elevated intramyocardial lipid levels and excessive iron in patients with diabetes suggest a predominant role of ferroptosis in diabetic cardiomyopathy. As myocardial cell death is a precursor of heart failure, and intensive glycemic control cannot abate the increased risk of heart failure in patients with diabetes, targeting myocardial cell death via ferroptosis is a promising therapeutic avenue to prevent and/or treat diabetic cardiomyopathy. This review provides updated and comprehensive molecular mechanisms underpinning ferroptosis, clarifies several misconceptions about ferroptosis, emphasizes the importance of ferroptosis in diabetes-induced myocardial cell death, and offers valuable approaches to evaluate and target ferroptosis in the diabetic heart. Furthermore, basic concepts and ideas presented in this review, including glutathione peroxidase-4-independent and mitochondrial mechanisms of ferroptosis, are also important for investigating ferroptosis in other diabetic organs, as well as nondiabetic and metabolically compromised hearts.

Cytomegalovirus (CMV) is a widely prevalent herpesvirus that reaches seroprevalence rates of up to 95% in several parts of the world. The majority of CMV infections are asymptomatic, albeit they have severe detrimental effects on immunocompromised individuals. Congenital CMV infection is a leading cause of developmental abnormalities in the USA. CMV infection is a significant risk factor for cardiovascular diseases in individuals of all ages. Like other herpesviruses, CMV regulates cell death for its replication and establishes and maintains a latent state in the host. Although CMV-mediated regulation of cell death is reported by several groups, it is unknown how CMV infection affects necroptosis and apoptosis in cardiac cells. Here, we infected primary cardiomyocytes, the contractile cells in the heart, and primary cardiac fibroblasts with wild-type and cell-death suppressor deficient mutant CMVs to determine how CMV regulates necroptosis and apoptosis in cardiac cells. Our results reveal that CMV infection prevents TNF-induced necroptosis in cardiomyocytes; however, the opposite phenotype is observed in cardiac fibroblasts. CMV infection also suppresses inflammation, reactive oxygen species (ROS) generation, and apoptosis in cardiomyocytes. Furthermore, CMV infection improves mitochondrial biogenesis and viability in cardiomyocytes. We conclude that CMV infection differentially affects the viability of cardiac cells.

Metabolic remodeling is at the heart of diabetic cardiomyopathy. High glycemic fluctuations increase metabolic stress in the type 1 diabetes mellitus (T1DM) heart. There is a lack of understanding on how metabolites and genes affect metabolic remodeling in the T1DM heart. We hypothesize that differential expression of metabolic genes and metabolites synergistically influence metabolic remodeling preceding T1DM cardiomyopathy. To test our hypothesis, we conducted high throughput analysis of hearts from adult male hyperglycemic Ins2+/− (Akita) and littermate normoglycemic Ins2+/+ (WT) mice. The Akita mouse is a spontaneous, genetic model of T1DM that develops increased levels of consistent glycemic variability without the off-target cardiotoxic effects present in chemically- induced models of T1DM. After validating the presence of a T1DM phenotype, we conducted metabolomics via LC-MS analysis and genomics via next-generation sequencing in left ventricle tissue from the Akita heart. Ingenuity Pathway Analyses revealed that 108 and 30 metabolic pathways were disrupted within the metabolomics and genomics datasets, respectively. Notably, a comparison between the two analyses showed 15 commonly disrupted pathways, including ketogenesis, ketolysis, cholesterol biosynthesis, acetyl CoA hydrolysis, and fatty acid biosynthesis and beta-oxidation. These identified metabolic pathways predicted by the differential expression of metabolites and genes provide the foundation for understanding metabolic remodeling in the T1DM heart. By limited experiment, we revealed a predicted disruption in the metabolites and genes behind T1DM cardiac metabolic derangement. Future studies targeting these genes and metabolites will unravel novel therapies to prevent/improve metabolic remodeling in the T1DM heart.