Abstract: The development of age-related cardiovascular (CV) dysfunction increases the risk of CV disease as well as other chronic age-associated disorders, including chronic kidney disease, and Alzheimer's disease and related dementias. Major manifestations of age-associated CV dysfunction that increase disease risk are vascular dysfunction, primarily vascular endothelial dysfunction and arterial stiffening, and elevated systolic blood pressure. Declines in nitric oxide bioavailability secondary to increased oxidative stress and inflammation are established mechanisms of CV dysfunction with aging. Moreover, fundamental mechanisms of aging, termed the "hallmarks of aging" extend to the CV system and, as such, may be considered "hallmarks of CV aging". These mechanisms represent viable therapeutic targets for treating CV dysfunction with aging. Healthy lifestyle behaviors, such as regular aerobic exercise and certain dietary patterns, are considered "first-line" strategies to prevent and/or treat age-associated CV dysfunction. Despite the well-established benefits of these strategies, many older adults do not meet the recommended guidelines for exercise or consume a healthy diet. Therefore, it is important to establish alternative and/or complementary evidence-based approaches to prevent or reverse age-related CV dysfunction. Targeting fundamental mechanisms of CV aging with interventions such as time-efficient exercise training, food-derived molecules, termed nutraceuticals, or select synthetic pharmacological agents represents a promising approach. In the present review, we will highlight emerging topics in the field of healthy CV aging with a specific focus on how exercise, nutrition/dietary patterns, nutraceuticals and select synthetic pharmacological compounds may promote healthy CV aging, in part, by targeting the hallmarks of CV aging.

Abstract: Introduction: Arrhythmogenic cardiomyopathy (ACM) is hereditary cardiomyopathy caused by pathogenic variants (mutations) in genes encoding the intercalated disc (ID), particularly desmosome proteins. ACM caused by mutations in the DSP gene encoding desmoplakin (DSP) is characterized by the prominence of cell death, myocardial fibrosis, and inflammation, and is referred to as desmoplakin cardiomyopathy. Aim: The aim of this article was to gain insight into the pathogenesis of DSP cardiomyopathy. Methods and Results: The Dsp gene was exclusively deleted in cardiac myocytes using tamoxifen-inducible MerCreMer (Myh6-McmTam) and floxed Dsp (DspF/F) mice (Myh6-McmTam:DspF/F). Recombination was induced upon subcutaneous injection of tamoxifen (30 mg/kg/d) for 5 days starting post-natal day 14. Survival was analyzed by Kaplan-Meier plots, cardiac function by echocardiography, arrhythmias by rhythm monitoring, and gene expression by RNA-Seq, immunoblotting, and immunofluorescence techniques. Cell death was analyzed by the TUNEL assay and the expression levels of specific markers were by RT-PCR and immunoblotting. Myocardial fibrosis was assessed by picrosirius red staining of the myocardial sections, RT-PCR, and immunoblotting. The Myh6-McmTam: DspF/F mice showed extensive molecular remodeling of the IDs and the differential expression of ~10,000 genes, which predicted activation of KDM5A, IRFs, and NFκB and suppression of PPARGC1A and RB1, among others in the DSP-deficient myocytes. Gene set enrichment analysis predicted activation of the TNFα/NFκB pathway, inflammation, cell death programs, and fibrosis. Analysis of cell death markers indicated PANoptosis, comprised of apoptosis (increased CASP3, CASP8, BAD and reduced BCL2), necroptosis (increased RIPK1, RIPK3, and MLKL), and pyroptosis (increased GSDMD and ASC or PYCARD) in the DSP-deficient myocytes. Transcript levels of the pro-inflammatory and pro-fibrotic genes were increased and myocardial fibrosis comprised ~25% of the myocardium in the DSP-deficient hearts. The Myh6-McmTam:DspF/F mice showed severe cardiac systolic dysfunction and ventricular arrhythmias, and died prematurely with a median survival rate of ~2 months. Conclusion: The findings identify PANoptosis as a prominent phenotypic feature of DSP cardiomyopathy and set the stage for delineating the specific molecular mechanisms involved in its pathogenesis. The model also provides the opportunity to test the effects of pharmacological and genetic interventions on myocardial fibrosis and cell death.

Abstract: The Cre-LoxP technology, including the tamoxifen (TAM) inducible MerCreMer (MCM), is increasingly used to delineate gene function, understand the disease mechanisms, and test therapeutic interventions. We set to determine the effects of TAM-MCM on cardiac myocyte transcriptome. Expression of the MCM was induced specifically in cardiac myocytes upon injection of TAM to myosin heavy chain 6-MCM (Myh6-Mcm) mice for 5 consecutive days. Cardiac function, myocardial histology, and gene expression (RNA-sequencing) were analyzed 2 weeks after TAM injection. A total of 346 protein coding genes (168 up- and 178 down-regulated) were differentially expressed. Transcript levels of 85 genes, analyzed by a reverse transcription-polymerase chain reaction in independent samples, correlated with changes in the RNA-sequencing data. The differentially expressed genes were modestly enriched for genes involved in the interferon response and the tumor protein 53 (TP53) pathways. The changes in gene expression were relatively small and mostly transient and had no discernible effects on cardiac function, myocardial fibrosis, and apoptosis or induction of double-stranded DNA breaks. Thus, TAM-inducible activation of MCM alters cardiac myocytes gene expression, provoking modest and transient interferon and DNA damage responses without exerting other discernible phenotypic effects. Thus, the effects of TAM-MCM on gene expression should be considered in discerning the bona fide changes that result from the targeting of the gene of interest.

Abstract: The development of novel therapies based on understanding the pathophysiologic basis of disease is a major goal of biomedical research. Despite an explosion in new knowledge on the molecular mechanisms of disease derived from animal model investigations, translation into effective treatment for human patients has been disappointingly slow. Several fundamental problems may explain the translational failures. First, the emphasis on novel and highly significant findings selectively rewards implausible, low-probability observations and high-magnitude effects, providing a biased perspective of the pathophysiology of disease that underappreciates the complexity and redundancy of biological systems. Second, even when a sound targetable mechanism is identified, animal models cannot recapitulate the pathophysiologic heterogeneity of the human disease, and are poor predictors of therapeutic success. Third, traditional classifications of most complex diseases are based primarily on clinical criteria and do not reflect the diverse pathophysiologic mechanisms that may be involved. The development of a flexible and dynamic conceptual paradigm that takes into account the totality of the evidence on the mechanisms of disease, and pathophysiologic stratification of patients to identify subpopulations with distinct pathogenetic mechanisms, are crucial for the development of new therapeutics.

Abstract: Introduction: Aging is associated with cardiac myocyte loss, sarcopenia, and cardiac dysfunction. Adult cardiac myocytes are postmitotic cells with an insufficient proliferative capacity to compensate for myocyte loss. The canonical WNT (cWNT) pathway is involved in the regulation of cell cycle reentry in various cell types. The effects of the cWNT pathway on the expression of genes involved in cell cycle reentry in the postmitotic cardiac myocytes are unknown. Aim: The aim of the study was to identify genes whose expression is regulated by the β-catenin, the indispensable component to the cWNT signaling, in the postmitotic myocytes. Methods and Results: Cardiac myocyte-specific tamoxifen-inducible MerCreMer (Myh6-Mcm) mice were used to delete the floxed exon 3 or exons 8 to 13 of the Ctnnb1 gene to induce gain-of-function (GoF) or loss-of-function (LoF) the β-catenin, respectively. Deletion of exon 3 leads to the expression of a stable β-catenin. In contrast, deletion of exons 8–13 leads to the expression of transcriptionally inactive truncated β-catenin, which is typically degraded. GoF or LoF of the β-catenin was verified by reverse transcription-polymerase chain reaction (RT-PCR), immunoblotting, and immunofluorescence. Myocyte transcripts were analyzed by RNA-Sequencing (RNA-Seq) at 4 weeks of age. The GoF of β-catenin was associated with differential expression of ~1700 genes, whereas its LoF altered expression of ~400 genes. The differentially expressed genes in the GoF myocytes were enriched in pathways regulating the cell cycle, including karyokinesis and cytokinesis, whereas the LoF was associated with increased expression of genes involved in mitochondrial oxidative phosphorylation. These findings were validated by RT-PCR in independent samples. Short-term GoF nor LoF of β-catenin did not affect the number of cardiac myocytes, cardiac function, myocardial fibrosis, myocardial apoptosis, or adipogenesis at 4 weeks of age. Conclusion: Activation of the β-catenin of the cWNT pathway in postmitotic myocytes leads to cell cycle reentry and expression of genes involved in cytokinesis without leading to an increase in the number of myocytes. In contrast, suppression of the β-catenin modestly increases the expression of genes involved in oxidative phosphorylation. The findings provide insights into the role of β-catenin of the cWNT pathway in the regulation of cell cycle reentry and oxidative phosphorylation in the postmitotic cardiac myocytes.

Abstract: Introduction The adult heart lacks the regenerative capacity to self-repair. Serum response factor (SRF) is essential for heart organogenesis, sarcomerogenesis, and contractility. SRF interacts with co-factors, such as NKX2.5 and GATA4, required for cardiac specified gene activity. ETS factors such as ELK1 interact with SRF and drive cell replication. To weaken SRF interactions with NKX2.5 and GATA4, one mutant, SRF153(A3) named STEMIN, did not bind CArG boxes, yet induced stem cell factors such as NANOG and OCT4, cardiomyocyte dedifferentiation, and cell cycle reentry. The mutant YAP5SA of the Hippo pathway also promotes cardiomyocyte proliferation and growth. Aim Infarcted adult mouse hearts were injected with translatable STEMIN and YAP5SA mmRNA to evaluate their clinical potential. Methods and Results Mice were pulsed one day later with alpha-EDU and then heart sections were DAPI stained. Replicating cells were identified by immuno-staining against members of the DNA replisome pathway that mark entry to S phase of the cell cycle. Echocardiography was used to determine cardiac function following infarcts and mRNA treatment. To monitor cardiac wall repair, microscopic analysis was performed, and the extent of myocardial fibrosis was analyzed for immune cell infiltration. Injections of STEMIN and YAP5SA mmRNA into the left ventricles of infarcted adult mice promoted a greater than 17-fold increase in the DAPI stained and alpha-EDU marked cardiomyocyte nuclei, within a day. We observed de novo expression of phospho-histone H3, ORC2, MCM2, and CLASPIN. Cardiac function was significantly improved by four weeks post-infarct, and fibrosis and immune cell infiltration were diminished in hearts treated with STEMIN and YAP5SA mmRNA than each alone. Conclusion STEMIN and YAP5SA mmRNA improved cardiac function and myocardial fibrosis in left ventricles of infarcted adult mice. The combinatorial use of mmRNA encoding STEMIN and YAP5SA has the potential to become a powerful clinical strategy to treat human heart disease.

Abstract: Introduction: Aortic stiffness offers important insight into vascular aging and cardiovascular disease (CVD) risk. The referent measure of aortic stiffness is carotid-femoral pulse wave velocity (cfPWV). cfPWV can be estimated (ePWV) from age and mean arterial pressure. Few studies have directly compared the association of ePWV to measured cfPWV, particularly in non-White adults. Moreover, whether ePWV and cfPWV correlate similarly with CVD risk remains unexplored. Aim: (1) To estimate the strength of the agreement between ePWV and cfPWV in both Black and White older adults; and (2) to compare the associations of ePWV and cfPWV with CVD risk factors and determine whether these associations were consistent across races. Methods and Results: We evaluated 4478 [75.2 (SD 5.0) years] Black and White older adults in the Atherosclerosis Risk in Communities (ARIC) Study. cfPWV was measured using an automated pulse waveform analyzer. ePWV was derived from an equation based on age and mean arterial pressure. Association and agreement between the two measurements were determined using Pearson’s correlation coefficient (r), standard error of estimate (SEE), and Bland-Altman analysis. Associations between traditional risk factors with ePWV and cfPWV were evaluated using linear mixed regression models. We observed weak correlations between ePWV and cfPWV within White adults (r = 0.36) and Black adults (r = 0.31). The mean bias for Bland-Altman analysis was low at −0.17 m/s (95%CI: −0.25 to −0.09). However, the inspection of the Bland-Altman plots indicated systematic bias (P < 0.001), which was consistent across race strata. The SEE, or typical absolute error, was 2.8 m/s suggesting high variability across measures. In models adjusted for sex, prevalent diabetes, the number of prevalent cardiovascular diseases, and medication count, both cfPWV and ePWV were positively associated with heart rate, triglycerides, and fasting glucose, and negatively associated with body mass index (BMI) and smoking status in White adults (P < 0.05). cfPWV and ePWV were not associated with heart rate, triglycerides, and fasting glucose in Black adults, while both measures were negatively associated with BMI in Black adults. Conclusions: Findings suggest a weak association between ePWV and cfPWV in older White and Black adults from ARIC. There were similar weak associations between CVD risk factors with ePWV and cfPWV in White adults with subtle differences in associations in Black adults.

Abstract: Numerous studies have revealed the critical role of premature senescence induced by various cancer treatment modalities in the pathogenesis of aging-related diseases. Senescence-associated secretory phenotype (SASP) can be induced by telomere dysfunction. Telomeric DNA damage response induced by some cancer treatments can persist for months, possibly accounting for long-term sequelae of cancer treatments. Telomeric DNA damage-induced mitochondrial dysfunction and increased reactive oxygen species production are hallmarks of premature senescence. Recently, we reported that the nucleus-mitochondria positive feedback loop formed by p90 ribosomal S6 kinase (p90RSK) and phosphorylation of S496 on ERK5 (a unique member of the mitogen-activated protein kinase family that is not only a kinase but also a transcriptional co-activator) were vital signaling events that played crucial roles in linking mitochondrial dysfunction, nuclear telomere dysfunction, persistent SASP induction, and atherosclerosis. In this review, we will discuss the role of NAD+ depletion in instigating SASP and its downstream signaling and regulatory mechanisms that lead to the premature onset of atherosclerotic cardiovascular diseases in cancer survivors.

Abstract: Introduction: Postoperative atrial fibrillation (POAF), characterized as AF that arises 1-3 days after surgery, occurs after 30%-40% of cardiac and 10%-20% of non-cardiac surgeries, and is thought to arise due to transient surgery-induced triggers acting on a preexisting vulnerable atrial substrate often associated with inflammation and autonomic nervous system dysfunction. Current experimental studies often rely on human atrial tissue samples, collected during surgery prior to arrhythmia development, or animal models such as sterile pericarditis and atriotomy, which have not been robustly characterized. Aim: To characterize the demographic, electrophysiologic, and inflammatory properties of a POAF mouse model. Methods and Results: A total of 131 wild-type C57BL/6J mice were included in this study. A total of 86 (65.6%) mice underwent cardiothoracic surgery (THOR), which consisted of bi-atrial pericardiectomy with 20 s of aortic cross-clamping; 45 (34.3%) mice underwent a sham procedure consisting of dissection down to but not into the thoracic cavity. Intracardiac pacing, performed 72 h after surgery, was used to assess AF inducibility. THOR mice showed greater AF inducibility (38.4%) compared to Sham mice (17.8%, P = 0.027). Stratifying the cohort by tertiles of age showed that the greatest risk of POAF after THOR compared to Sham occurred in the 12-19-week age group. Stratifying by sex showed that cardiothoracic (CT) surgery increased POAF risk in females but had no significant effect in males. Quantitative polymerase chain reaction of atrial samples revealed upregulation of transforming growth factor beta 1 (TGF-β1) and interleukin 6 (IL6) and 18 (IL18) expression in THOR compared to Sham mice. Conclusion: Here, we demonstrate that the increased POAF risk associated with CT surgery is most pronounced in female and 12-19-week-old mice, and that the expression of inflammatory cytokines is upregulated in the atria of THOR mice prone to inducible AF.

Abstract: Introduction: Aging is associated with sarcopenia, myocyte loss, and dysfunction. The problem is compounded as the adult heart lacks the regenerative capacity to self-repair. Serum response factor’s (SRF’s) dual activity is essential for cell replication and heart cell differentiation. SRF interacts with cofactors, such as NKX2-5 and GATA4, which give cardiac-specific gene activity, and ETS factors such as ELK1 drive cell replication. Recently, the mutant YAP-5SA of the Hippo pathway was implicated in cardiomyocyte proliferation and growth. Aim: We hypothesized that disruption of interactions of SRF with NKX2-5 and GATA4 would lead to dedifferentiation of cardiomyocytes to a proliferative stem cell state and complement YAP-5SA to generate undifferentiated cardiomyocytes in a more primitive replicative state. Methods and results: To weaken SRF interactions with NKX2-5 and GATA4, alanine scanning mutations were generated across the SRF N-terminus of the MADS-box. One SRF mutant, SRF153(A3), was tested along with the YAP-5SA mutant, as degradable synthetic modified mRNAs (mmRNAs), in rat primary cardiomyocytes. To measure cell replication, adult cardiomyocytes were pulsed with alpha-EdU and then DAPI stained, while gene activity was assayed by RNA sequencing. To measure chromatin remodeling, Transposon 5 was used in ATAC sequencing. We observed that single and triple alanine substitutions of mutants centering over SRF-Lys154 essentially blocked myocyte differentiation, and NKX2-5 and GATA4 failed to stabilize mutated SRF DNA binding. Instead, many stem cell factors including NANOG and OCT4 were induced. SRF153(A3) does not recognize SRF response elements per ATAC sequencing and consequently induces stem cell factors such as NANOG and OCT4, cardiomyocyte dedifferentiation, and cell cycle reentry. SRF153(A3) and YAP5SA mmRNA led to alpha-EDU incorporation in ~35% of the cardiomyocytes. DIAPH 3, a marker of the contractile ring during anaphase, appeared between and around replicated nuclei in three-month-old adult mouse cardiac myocytes. The combination of these synthetic mRNA increased nuclei replication with the expression of origin of replication genes, while genes associated with cardiomyocyte differentiation were down-regulated. ATAC sequencing revealed SRF153(A3) and YAP5SA mmRNA-induced chromatin remodeling of cell cycle, spindle, and growth factor genes by additive and synergistic activities. Conclusion: SRF153(A3) synthetic mmRNA and the mutant YAP-5SA mmRNA induced cardiomyocyte dedifferentiation, to nuclear replication in adult cardiac myocytes. The combinatorial use of mmRNA encoding SRF153(A3) and YAP-5SA has the potential to become a powerful clinical strategy for treating human heart disease.

Abstract: Cardiovascular disease and myocardial infarction are leading causes of morbidity and mortality in aged populations. Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) are under evaluation as a therapeutic option for the treatment of myocardial infarction.This study aimed to develop a large-scale manufacturing procedure to harvest clinical-grade EVs required for the translation of EVs to the clinic.We compared the efficiency of large scale MSC-derived EV production and characterized EV miRNA cargo using the Quantum bioreactor with either fetal bovine serum or human platelet lysate (PLT)-containing expansion media. We tested the potency of the EV products in a murine model of acute myocardial infarction. Our results demonstrate an advantage of the Quantum bioreactor as a large-scale platform for EV production using PLT media; however, both media produced EVs with similar effects in vivo. The systemic delivery of EV products improved cardiac function following myocardial infarctions as indicated by a significant improvement in ejection fraction as well as parameters of cardiac performance, afterload, contractility and lusitropy.These findings have important implications for scale-up strategies of EVs and will facilitate clinical trials for their clinical evaluation.

Abstract: OAE Publishing Inc. is an international scholarly publisher specializing in peer-reviewed academic journals. To promote academic exchange and knowledge sharing, OAE provides an outstanding academic platform for biomedical experts and scholars all over the world.

Abstract: Cardiac aging is accompanied by progressive loss of cellular function, leading to impaired heart function and heart failure. There is an urgent need for efficient strategies to combat this age-related cardiac dysfunction. A growing number of events suggest that age-related cardiac diseases are tightly related to metabolic imbalance. This review summarizes recent findings concerning metabolic changes during cardiac aging and highlights the therapeutic approaches that target metabolic pathways in cardiac aging.

Abstract: © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Abstract: Ischemic heart disease and heart failure (HF) remain the leading causes of death worldwide. The inability of the adult heart to regenerate itself following ischemic injury and subsequent scar formation may explain the poor prognosis in these patients, especially when necrosis is extensive and leads to severe left ventricular dysfunction. Under physiological conditions, the crosstalk between cardiomyocytes and cardiac interstitial/vascular cells plays a pivotal role in cardiac processes by limiting ischemic damage or promoting repair processes, such as angiogenesis, regulation of cardiac metabolism, and the release of soluble paracrine or endocrine factors. Cardiovascular risk factors are the main cause of accelerated senescence of cardiomyocytes and cardiac stromal cells (CSCs), causing the loss of their cardioprotective and repairing functions. CSCs are supportive cells found in the heart. Among these, the pericytes/mural cells have the propensity to differentiate, under appropriate stimuli in vitro, into adipocytes, smooth muscle cells, osteoblasts, and chondroblasts, as well as other cell types. They contribute to normal cardiac function and have an antifibrotic effect after ischemia. Diabetes represents a condition of accelerated senescence. Among the new pharmacological armamentarium with hypoglycemic effect, gliflozins have been shown to reduce the incidence of HF and re-hospitalization, probably through the anti-remodeling and anti-senescent effect on the heart, regardless of diabetes. Therefore, either reducing the senescence of CSC or removing senescent cells from the infarcted heart could represent future antisenescence strategies capable of preventing the deterioration of heart function leading to HF.

Abstract: © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Abstract: Aging is an archetypical complex process influenced by genetic and environmental factors. Genetic variants impart a gradient of effect sizes, albeit the effect sizes seem to be skewed toward those with small effect sizes. On one end of the spectrum are the rare monogenic premature aging syndromes, such as Hutchinson Gilford Progeria Syndrome, whereby single nucleotide changes lead to rapidly progressive premature aging. On the end of the spectrum is the complex, slowly progressive process of living to an arbitrary-defined old age, i.e., longevity. Whereas the genetic basis of rare premature aging syndromes has been elucidated, only a small fraction of the genetic determinants of longevity and life span, time from birth to death, have been identified. The latter point to the complexity of the process and involvement of myriad of genetic and non-genetic factors and hence, the diluted effect of each determinant on longevity. The genetic discoveries point to the involvement of the DNA damage and activation of the DNA damage response pathway, particularly in the premature aging syndromes. Likewise, the insulin/insulin-like growth factor 1/mTOR/FOXO pathways have emerged as major regulators of life span. A notable fraction of the genetic variants that are associated with life span is also associated with age-related cardiovascular diseases, such as coronary artery disease and dyslipidemia, which places cardiovascular aging at the core of human life span. The clinical impact of the discoveries pertains to the identification of the pathways that are involved in life span, which might serve as targets of interventions to prevent, slow, and even possibly reverse aging.

Abstract: Cellular senescence is a concerted process that involves a stable cell cycle arrest despite continued metabolic activity, and the development of a pro-inflammatory response known as the senescence-associated secretory phenotype (SASP) [1] . Aging and senescence have long been associated, and studies employing senolytic approaches, i.e., the targeted removal of senescent cells, have demonstrated a causal role for their actions in aging-related phenotypes in various tissues [2] . Presumably, due to the nature of SASP, this process is largely non-cell autonomous and involves paracrine effects on neighboring cells to promote organ dysfunction. senolytic approaches aging-related tissue linked physiological aging and cellular to a decline in mechanotransduction mediated by decreased YAP/TAZ activity findings

Abstract: The molecular determinants of lifespan can be examined in animal models with the long-term objective of applying what is learned to the development of strategies to enhance longevity in humans. Here, we comment on a recent publication examining the molecular mechanisms that determine lifespan in worms, Caenorhabditis elegans (C. elegans), where it was shown that inhibiting protein synthesis increased levels of the transcription factor, ATF4. Gene expression analyses showed that ATF4 increased the expression of genes responsible for the formation of the gas, hydrogen sulfide (H2S). Further examination showed that H2S increased longevity in C. elegans by modifying proteins in ways that stabilize their structures and enhance their functions. H2S has been shown to improve cardiovascular performance in mouse models of heart disease, and clinical trials are underway to test the effects of H2S on cardiovascular health in humans. These findings support the concept that nutrient deprivation, which slows protein synthesis and leads to ATF4-mediated H2S production, may extend lifespan by improving the function of the cardiovascular system and other systems that influence longevity in humans.

Abstract: Introduction: The TNNI3 gene encodes the protein of cardiac troponin I (cTnI), which is an inhibitory subunit of sarcomeres. Mutations in this gene account for 3% of hypertrophic cardiomyopathy (HCM) and the molecular mechanism is complex. Recently, lipid metabolism has been revealed to be involved in HCM. Aim: The purpose of this work is to identify whether the pathological mechanism of the hotspot mutation TNNI3 p.R186Q in HCM is related to abnormal lipid metabolism. Methods and Results: A knock-in (KI) mouse model carrying the Tnni3 p.R186Q homozygous mutation (Tnni3R186Q/R186Q) was novelty generated by CRISPR/Cas9 technology and successfully constructed a typical phenotype of cardiac-myopathy. Likewise, neonatal rat cardiomyocytes (NRCMs) transfected with a mutant plasmid with the TNNI3 p.R186Q mutation showed the same phenomenon. In-depth experiments on related functions and molecular mechanisms were conducted, and Tnni3R186Q/R186Q mice exhibited abnormal fatty acid metabolism, which was induced by the activation of epidermal growth factor receptor (EGFR)-dependent high expression of fatty acid synthase (FASN) in vivo and in vitro. Specifically, the direct binding of EGFR and cTnI was destroyed by TNNI3 p.R186Q mutation, as observed through bioinformatics, Co-IP and GST-pull down analysis. Conclusion: In the present study, we successfully engineered Tnni3R186Q/R186Q mice with the typical phenotype of myocardial hypertrophy. We demonstrated that the TNNI3 p.R186Q mutation could induce HCM by the dissociation of EGFR and cTnI, which further led to EGFR-dependent increased expression of FASN and abnormal lipid metabolism.

Abstract: Rurik et al. [1] published in Science provide results from an elegant proof-of-concept study that modified messenger RNA (mRNA) encapsulated in targeted lipid nanoparticles (LNPs) can be delivered intravenously to produce functional engineered T cells in vivo . Specifically, they generated transient anti-fibrotic chimeric antigen receptor (CAR) T cells in vivo by delivering modified mRNA in CD5 T cell-targeted LNPs.

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Abstract: The Cre-loxP system is a powerful and versatile tool to control site-specific recombination of mammalian genomic DNA. Site-specific Cre recombinase-mediated DNA recombination allows for the conditional control of gene expression within transgenic animals in a tissuespecific manner by employing a promoter known to be expressed specifically in such tissue of interest. More specifically, the gene of interest is flanked (floxed) by two loxP (locus of x-over, P1) sites in the presence of Cre recombinase, which then catalyzes the site-specific recombination of DNA between those loxP sites, leading to tissue-specific gene editing. However, the approach is flawed by the lack of control over the timing of Cre recombinase expression which often parallels the expression of the chosen promoter. Consequently, Cre-

Abstract: Mitochondria are central arbiters of cell fate. Mitochondrial respiration produces ATP, the chemical fuel for most biological processes in multicellular organisms. Conversely, mitochondrial respiration that is not properly coupled to ATP synthesis produces mito- and cytotoxic reactive oxygen species (ROS) that can damage cell and organelle DNA, protein and lipid, thereby evoking premature cell senescence or programmed death. The dual role of mitochondria as sustainers of cell life vs engines of cell death requires cells to deploy surveillance and removal systems that identify, isolate and selectively

Abstract: Circadian rhythms are 24-h biological rhythms that are necessary for optimal health and daily variances in physiology and behavior. Circadian rhythms are maintained at the cellular level and are necessary for organ-specific functions. Cardiac tissue is no exception, and the heart maintains strong rhythms in gene expression as well as cellular metabolism throughout its lifespan [1] . Aging is associated with the gradual decline of circadian rhythms, raising the question of whether pharmacological or behavioral mechanisms that increase circadian robustness can slow the aging process. Time-restricted feeding is one mechanism to augment internal rhythms, decreased fat mass compared to ad libitum -fed mice); and (3) changes in circulating glucose in aged mice. Specifically, though insulin levels were similar in young AL and CR mice, circulating glucose was decreased in CR, suggesting increased insulin sensitivity. Upon aging, though all CR mice had lower insulin levels, even aged CR mice showed elevations in glucose, similar to AL groups. Thus, CR protects against insulin resistance across the lifespan.

Abstract: © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Abstract: © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Abstract: Identification of factors that lead to the severe clinical course of COVID-19 is crucial for timely allocation of resources. The purpose of this study was to evaluate possible sex differences in cardiac injury associated with HLA-C*04:01. High sensitivity troponin T on admission (hs-TnTa) and maximum high sensitivity troponin T (hs-TnTmax) were used to assess for cardiac injury in patients with COVID-19 (n = 435). We tested for the association of elevated hs-TnT with HLA-C* 04:01 and evaluated for potential sex-specific differences. An association between hs-TnTa and the severity of clinical course was identified. In addition, our study revealed that hs-TnTmax was higher in men who were carriers of HLA-C*04:01 compared to men without the risk allele. Male carriers of HLA-C*04:01 with COVID-19 developed higher hs-TnTmax, suggesting a larger extent of cardiac injury. This association suggests the presence of different pathomechanisms in COVID-19 based on sex.

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