Insights into Molecular and Cellular Functions of the Golgi Calcium/Manganese-Proton Antiporter TMEM165.

The Golgi compartment performs a number of crucial roles in the cell. However, the exact molecular mechanisms underlying these actions are not fully defined. Pathogenic mutations in genes encoding Golgi proteins may serve as an important source for expanding our knowledge. For instance, mutations in the gene encoding Transmembrane protein 165 (TMEM165) were discovered as a cause of a new type of congenital disorder of glycosylation (CDG). Comprehensive studies of TMEM165 in different model systems, including mammals, yeast, and fish uncovered the new realm of Mn2+ homeostasis regulation. TMEM165 was shown to act as a Ca2+/Mn2+:H+ antiporter in medial- and trans-Golgi network, pumping the metal ions into the Golgi lumen and protons outside. Disruption of TMEM165 antiporter activity results in defects in N- and O-glycosylation of proteins and glycosylation of lipids. An impaired glycosylation of TMEM165-CDG arises from lack of Mn2+ within the Golgi. Nevertheless, Mn2+ insufficiency in the Golgi is compensated by the activity of the ATPase SERCA2. TMEM165 turnover has also been found to be regulated by Mn2+ cytosolic concentration. Besides causing CDG, recent investigations have demonstrated the functional involvement of TMEM165 in several other pathologies including cancer and mental health disorders. This systematic review summarizes the available information on TMEM165 molecular structure, cellular function, and its roles in health and disease.

Endothelial Extracellular Vesicles Enriched in microRNA-34a Predict New-Onset Diabetes in Coronavirus Disease 2019 (COVID-19) Patients: Novel Insights for Long COVID Metabolic Sequelae.

Emerging evidence indicates that the relationship between coronavirus disease 2019 (COVID-19) and diabetes is 2-fold: 1) it is known that the presence of diabetes and other metabolic alterations poses a considerably high risk to develop a severe COVID-19; 2) patients who survived a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have an increased risk of developing new-onset diabetes. However, the mechanisms underlying this association are mostly unknown, and there are no reliable biomarkers to predict the development of new-onset diabetes. In the present study, we demonstrate that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells reliably predicts the risk of developing new-onset diabetes in COVID-19. This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. SIGNIFICANCE STATEMENT: We demonstrate for the first time that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells is able to reliably predict the risk of developing diabetes after having contracted coronavirus disease 2019 (COVID-19). This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. Our findings are also relevant when considering the emerging importance of post-acute sequelae of COVID-19, with systemic manifestations observed even months after viral negativization (long COVID).

Endothelial microRNAs in INOCA patients with diabetes mellitus.

Ischemia with non-obstructive coronary artery (INOCA) is a common cause of hospital admissions, leading to negative outcomes and reduced quality of life. Central to its pathophysiology is endothelial dysfunction, which contributes to myocardial ischemia despite the absence of significant coronary artery blockage. Addressing endothelial dysfunction is essential in managing INOCA to alleviate symptoms and prevent cardiovascular events. Recent studies have identified diabetes mellitus (DM) as a significant factor exacerbating INOCA complications by promoting endothelial impairment and coronary microvascular dysfunction. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets in various biological processes, including endothelial dysfunction and cardiovascular diseases. However, research on miRNA biomarkers in INOCA patients is sparse. In this study, we examined a panel of circulating miRNAs involved in the regulation of endothelial function in INOCA patients with and without DM. We analyzed miRNA expression using RT-qPCR in a cohort of consecutive INOCA patients undergoing percutaneous coronary intervention. We detected a significant dysregulation of miR-363-5p and miR-92a-3p in INOCA patients with DM compared to those without DM, indicating their role as biomarkers for predicting and monitoring endothelial dysfunction in INOCA patients with DM.

Infiltrating macrophages amplify doxorubicin-induced cardiac damage: role of catecholamines.

BACKGROUND: The functional contribution of non-myocyte cardiac cells, such as inflammatory cells, in the setup of heart failure in response to doxorubicin (Dox) is recently becoming of growing interest. OBJECTIVES: The study aims to evaluate the role of macrophages in cardiac damage elicited by Dox treatment. METHODS: C57BL/6 mice were treated with one intraperitoneal injection of Dox (20 mg/kg) and followed up for 5 days by cardiac ultrasounds (CUS), histological, and flow cytometry evaluations. We also tested the impact of Dox in macrophage-depleted mice. Rat cardiomyoblasts were directly treated with Dox (D-Dox) or with a conditioned medium from cultured murine macrophages treated with Dox (M-Dox). RESULTS: In response to Dox, macrophage infiltration preceded cardiac damage. Macrophage depletion prevents Dox-induced damage, suggesting a key role of these cells in promoting cardiotoxicity. To evaluate the crosstalk between macrophages and cardiac cells in response to DOX, we compared the effects of D-Dox and M-Dox in vitro. Cell vitality was lower in cardiomyoblasts and apoptosis was higher in response to M-Dox compared with D-Dox. These events were linked to p53-induced mitochondria morphology, function, and autophagy alterations. We identify a mechanistic role of catecholamines released by Dox-activated macrophages that lead to mitochondrial apoptosis of cardiac cells through ß-AR stimulation. CONCLUSIONS: Our data indicate that crosstalk between macrophages and cardiac cells participates in cardiac damage in response to Dox.

Mitochondrial microRNAs Are Dysregulated in Patients with Fabry Disease.

Fabry disease (FD) is a lysosomal storage disorder caused by mutations in the gene for α-galactosidase A, inducing a progressive accumulation of globotriaosylceramide (GB3) and its metabolites in different organs and tissues. GB3 deposition does not fully explain the clinical manifestations of FD, and other pathogenetic mechanisms have been proposed, requiring the identification of new biomarkers for monitoring FD patients. Emerging evidence suggests the involvement of mitochondrial alterations in FD. Here, we propose mitochondrial-related microRNAs (miRs) as potential biomarkers of mitochondrial involvement in FD. Indeed, we demonstate that miRs regulating different aspects of mitochondrial homeostasis including expression and assembly of respiratory chain, mitogenesis, antioxidant capacity, and apoptosis are consistently dysregulated in FD patients. Our data unveil a novel noncoding RNA signature of FD patients, indicating mitochondrial-related miRs as new potential pathogenic players and biomarkers in FD. SIGNIFICANCE STATEMENT: This study demonstrates for the first time that a specific signature of circulating mitochondrial miRs (mitomiRs) is dysregulated in FD patients. MitomiRs regulating fundamental aspects of mitochondrial homeostasis and fitness, including expression and assembly of the respiratory chain, mitogenesis, antioxidant capacity, and apoptosis are significantly dysregulated in FD patients. Taken together, these new findings introduce mitomiRs as unprecedented biomarkers of FD and point at mitochondrial dysfunction as a novel potential mechanistic target for therapeutic approaches.

Cardiovascular Implications of microRNAs in Coronavirus Disease 2019.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to be a global challenge due to resulting morbidity and mortality. Cardiovascular (CV) involvement is a crucial complication in coronavirus disease 2019 (COVID-19), and no strategies are available to prevent or specifically address CV events in COVID-19 patients. The identification of molecular partners contributing to CV manifestations in COVID-19 patients is crucial for providing early biomarkers, prognostic predictors, and new therapeutic targets. The current report will focus on the role of microRNAs (miRNAs) in CV complications associated with COVID-19. Indeed, miRNAs have been proposed as valuable biomarkers and predictors of both cardiac and vascular damage occurring in SARS-CoV-2 infection. SIGNIFICANCE STATEMENT: It is essential to identify the molecular mediators of coronavirus disease 2019 (COVID-19) cardiovascular (CV) complications. This report focused on the role of microRNAs in CV complications associated with COVID-19, discussing their potential use as biomarkers, prognostic predictors, and therapeutic targets.

Exosomal miR-145 and miR-885 Regulate Thrombosis in COVID-19.

We hypothesized that exosomal microRNAs could be implied in the pathogenesis of thromboembolic complications in coronavirus disease 2019 (COVID-19). We isolated circulating exosomes from patients with COVID-19, and then we divided our population in two arms based on the D-dimer level on hospital admission. We observed that exosomal miR-145 and miR-885 significantly correlate with D-dimer levels. Moreover, we demonstrate that human endothelial cells express the main cofactors needed for the internalization of the "Severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), including angiotensin converting enzyme 2, transmembrane protease serine 2, and CD-147. Interestingly, human endothelial cells treated with serum from COVID-19 patients release significantly less miR-145 and miR-885, exhibit increased apoptosis, and display significantly impaired angiogenetic properties compared with cells treated with non-COVID-19 serum. Taken together, our data indicate that exosomal miR-145 and miR-885 are essential in modulating thromboembolic events in COVID-19. SIGNIFICANCE STATEMENT: This work demonstrates for the first time that two specific microRNAs (namely miR-145 and miR-885) contained in circulating exosomes are functionally involved in thromboembolic events in COVID-19. These findings are especially relevant to the general audience when considering the emerging prominence of post-acute sequelae of COVID-19 systemic manifestations known as Long COVID.

Molecular Mechanisms Underlying Pluripotency and Self-Renewal of Embryonic Stem Cells.

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the blastocyst. ESCs have two distinctive properties: ability to proliferate indefinitely, a feature referred as "self-renewal", and to differentiate into different cell types, a peculiar characteristic known as "pluripotency". Self-renewal and pluripotency of ESCs are finely orchestrated by precise external and internal networks including epigenetic modifications, transcription factors, signaling pathways, and histone modifications. In this systematic review, we examine the main molecular mechanisms that sustain self-renewal and pluripotency in both murine and human ESCs. Moreover, we discuss the latest literature on human naïve pluripotency.

Diabetes and restenosis.

Restenosis, defined as the re-narrowing of an arterial lumen after revascularization, represents an increasingly important issue in clinical practice. Indeed, as the number of stent placements has risen to an estimate that exceeds 3 million annually worldwide, revascularization procedures have become much more common. Several investigators have demonstrated that vessels in patients with diabetes mellitus have an increased risk restenosis. Here we present a systematic overview of the effects of diabetes on in-stent restenosis. Current classification and updated epidemiology of restenosis are discussed, alongside the main mechanisms underlying the pathophysiology of this event. Then, we summarize the clinical presentation of restenosis, emphasizing the importance of glycemic control in diabetic patients. Indeed, in diabetic patients who underwent revascularization procedures a proper glycemic control remains imperative.

Correlation of physical and cognitive impairment in diabetic and hypertensive frail older adults.

BACKGROUND: Diabetes and hypertension are common in older adults and represent established risk factors for frailty. Frailty is a multidimensional condition due to reserve loss and susceptibility to stressors with a high risk of death, hospitalizations, functional and cognitive impairment. Comorbidities such as diabetes and hypertension play a key role in increasing the risk of mortality, hospitalization, and disability. Moreover, frail patients with diabetes and hypertension are known to have an increased risk of cognitive and physical impairment. Nevertheless, no study assessed the correlation between physical and cognitive impairment in frail older adults with diabetes and hypertension. METHODS: We evaluated consecutive frail older patients with diabetes and hypertension who presented at ASL (local health unit of the Italian Ministry of Health) Avellino, Italy, from March 2021 to October 2021. The inclusion criteria were: a previous diagnosis of diabetes and hypertension with no evidence of secondary causes; age > 65 years; a frailty status; Montreal Cognitive Assessment (MoCA) score < 26. RESULTS: 179 patients successfully completed the study. We found a strong and significant correlation between MoCA score and 5-m gait speed test (r: 0.877; p < 0.001). To further verify our results, we performed a linear multivariate analysis adjusting for potential confounding factors, with MoCA score as dependent variable, which confirmed the significant association with glycemia (p < 0.001). CONCLUSIONS: This is the first study showing a significant correlation between 5-m gait speed test and MoCA score in frail diabetic and hypertensive older adults.

Cognitive dysfunction correlates with physical impairment in frail patients with acute myocardial infarction.

BACKGROUND: To the best of our knowledge, the association of physical impairment and cognitive decline has never been investigated in frail patients with acute myocardial infarction. AIM: The aim of our study is to assess the correlation between physical and cognitive dysfunction in frail patients with ST-elevation myocardial infarction (STEMI). METHODS: We examined consecutive frail patients with first STEMI treated with primary percutaneous coronary intervention (PPCI). All patients were evaluated via Mini Mental State Examination (MMSE) and 5-m gait speed test after PPCI. RESULTS: A total of 871 frail patients with suspected STEMI were admitted and 301 patients successfully completed the study. We found that the gait speed significantly correlated with the MMSE score (r: 0.771; p: < 0.001). The independent effects on MMSE score were confirmed in a linear multivariate analysis. CONCLUSIONS: Taken together, our findings indicate that an assessment of both cognitive and physical conditions should be included in the comprehensive geriatric evaluation of hospitalized older STEMI patients.

miR-142 Targets TIM-1 in Human Endothelial Cells: Potential Implications for Stroke, COVID-19, Zika, Ebola, Dengue, and Other Viral Infections.

T-cell immunoglobulin and mucin domain 1 (TIM-1) has been recently identified as one of the factors involved in the internalization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human cells, in addition to angiotensin-converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), neuropilin-1, and others. We hypothesized that specific microRNAs could target TIM-1, with potential implications for the management of patients suffering from coronavirus disease 2019 (COVID-19). By combining bioinformatic analyses and functional assays, we identified miR-142 as a specific regulator of TIM-1 transcription. Since TIM-1 has been implicated in the regulation of endothelial function at the level of the blood-brain barrier (BBB) and its levels have been shown to be associated with stroke and cerebral ischemia-reperfusion injury, we validated miR-142 as a functional modulator of TIM-1 in human brain microvascular endothelial cells (hBMECs). Taken together, our results indicate that miR-142 targets TIM-1, representing a novel strategy against cerebrovascular disorders, as well as systemic complications of SARS-CoV-2 and other viral infections.

A Retinoic Acid Receptor ß 2 Agonist Improves Cardiac Function in a Heart Failure Model.

We previously demonstrated that the selective retinoic acid receptor (RAR) ß 2 agonist AC261066 reduces oxidative stress in an ex vivo murine model of ischemia/reperfusion. We hypothesized that by decreasing oxidative stress and consequent fibrogenesis, AC261066 could attenuate the development of contractile dysfunction in post-ischemic heart failure (HF). We tested this hypothesis in vivo using an established murine model of myocardial infarction (MI), obtained by permanent occlusion of the left anterior descending coronary artery. Treating mice with AC261066 in drinking water significantly attenuated the post-MI deterioration of echocardiographic indices of cardiac function, diminished remodeling, and reduced oxidative stress, as evidenced by a decrease in malondialdehyde level and p38 mitogen-activated protein kinase expression in cardiomyocytes. The effects of AC261066 were also associated with a decrease in interstitial fibrosis, as shown by a marked reduction in collagen deposition and α-smooth muscle actin expression. In cardiac murine fibroblasts subjected to hypoxia, AC261066 reversed hypoxia-induced decreases in superoxide dismutase 2 and angiopoietin-like 4 transcriptional levels as well as the increase in NADPH oxidase 2 mRNA, demonstrating that the post-MI cardioprotective effects of AC261066 are associated with an action at the fibroblast level. Thus, AC261066 alleviates post-MI cardiac dysfunction by modulating a set of genes involved in the oxidant/antioxidant balance. These AC261066 responsive genes diminish interstitial fibrogenesis and remodeling. Since MI is a recognized major cause of HF, our data identify RARß 2 as a potential pharmacological target in the treatment of HF. SIGNIFICANCE STATEMENT: A previous report showed that the selective retinoic acid receptor (RAR) ß 2 agonist AC261066 reduces oxidative stress in an ex vivo murine model of ischemia/reperfusion. This study shows that AC261066 attenuates the development of contractile dysfunction and maladaptive remodeling in post-ischemic heart failure (HF) by modulating a set of genes involved in oxidant/antioxidant balance. Since myocardial infarction is a recognized major cause of HF, these data identify RARß 2 as a potential pharmacological target in the treatment of HF.

Impact of thrombus aspiration in frail STEMI patients.

BACKGROUND: Despite primary percutaneous coronary intervention (PPCI) is generally considered the best therapy in older frail adults with ST-segment elevation myocardial infarction (STEMI), the incidence of re-hospitalization for cardiovascular diseases remains significant in these patients. AIMS: We hypothesized that thrombus aspiration (TA) before PPCI could be a useful treatment for reducing mortality and rehospitalizations in frail patients undergoing PPCI for STEMI. METHODS: We conducted a study comparing PPCI alone vs TA + PPCI in frail STEMI patients. We examined a cohort of consecutive frail patients aged ≥ 65 years with first STEMI treated with PPCI between February 2008 and July 2015 at the Department of Cardiology of the "Cardarelli" Hospital in Naples, Italy. RESULTS: The study was completed by 389 patients (PPCI: 195, TA + PPCI: 194). At 1-month follow-up, the rate of death from any cause was 7.0% in patients treated with PPCI alone vs 3.0% in patients treated with TA + PPCI (p 0.036), whereas death from cardiovascular causes was 6.0% in the PPCI group vs 3.0% in the TA + PPCI group (p 0.028). Equally important, the rate of re-hospitalization due to heart failure was 7.5% in the PPCI group vs 4.0% in TA + PPCI group (p 0.025) and the rate of re-hospitalization due to acute coronary syndrome was 10.0% in the PPCI group vs 4.5% in the TA + PPCI group (p 0.016). CONCLUSION: These results indicate the importance of TA in the treatment of STEMI in a group of high-risk patients such as elderly with frailty.

Implications of AB0 blood group in hypertensive patients with covid-19.

BACKGROUND: Hypertension is the most frequent co-morbidity in patients with covid-19 infection, and we might speculate that a specific blood group could play a key role in the clinical outcome of hypertensive patients with covid-19. METHODS: In this prospective study, we compared 0 vs. non-0 blood group in hypertensive patients with covid-19 infection. In these patients, we evaluated inflammatory and thrombotic status, cardiac injury, and death events. RESULTS: Patients in non-0 (n = 92) vs. 0 blood group (n = 72) had significantly different values of activated pro-thrombin time, D-dimer, and thrombotic indexes as Von Willebrand factor and Factor VIII (p < 0.05). Furthermore, patients in non-0 vs. 0 blood group had higher rate of cardiac injury (10 (13.9%) vs. 27 (29.3%)) and death, (6 (8.3%) vs. 18 (19.6%)), (p < 0.05). At the multivariate analysis, Interleukin-6 (1.118, CI 95% 1.067-1.171) and non-0 blood group (2.574, CI 95% 1.207-5.490) were independent predictors of cardiac injury in hypertensive patients with covid-19. D-dimer (1.082, CI 95% 1.027-1.140), Interleukin-6 (1.216, CI 95% 1.082-1.367) and non-0 blood group (3.706, CI 95% 1.223-11.235) were independent predictors of deaths events in hypertensive patients with covid-19. CONCLUSIONS: Taken together, our data indicate that non-0 covid-19 hypertensive patients have significantly higher values of pro-thrombotic indexes, as well as higher rate of cardiac injury and deaths compared to 0 patients. Moreover, AB0 blood type influences worse prognosis in hypertensive patients with covid-19 infection.

Antidiabetic and Cardioprotective Effects of Pharmacological Inhibition of GRK2 in db/db Mice.

Despite the availability of several therapies for the management of blood glucose in diabetic patients, most of the treatments do not show benefits on diabetic cardiomyopathy, while others even favor the progression of the disease. New pharmacological targets are needed that might help the management of diabetes and its cardiovascular complications at the same time. GRK2 appears a promising target, given its established role in insulin resistance and in systolic heart failure. Using a custom peptide inhibitor of GRK2, we assessed in vitro in L6 myoblasts the effects of GRK2 inhibition on glucose extraction and insulin signaling. Afterwards, we treated diabetic male mice (db/db) for 2 weeks. Glucose tolerance (IGTT) and insulin sensitivity (ITT) were ameliorated, as was skeletal muscle glucose uptake and insulin signaling. In the heart, at the same time, the GRK2 inhibitor ameliorated inflammatory and cytokine responses, reduced oxidative stress, and corrected patterns of fetal gene expression, typical of diabetic cardiomyopathy. GRK2 inhibition represents a promising therapeutic target for diabetes and its cardiovascular complications.

New Insights in Cardiac Calcium Handling and Excitation-Contraction Coupling.

Excitation-contraction (EC) coupling denotes the conversion of electric stimulus in mechanic output in contractile cells. Several studies have demonstrated that calcium (Ca2+) plays a pivotal role in this process. Here we present a comprehensive and updated description of the main systems involved in cardiac Ca2+ handling that ensure a functional EC coupling and their pathological alterations, mainly related to heart failure.

Mechanistic Role of Kinases in the Regulation of Mitochondrial Fitness.

Mounting evidence indicates that mitochondria contain multiple phosphorylation substrates and that protein kinases translocate into mitochondria, suggesting that protein phosphorylation in this organelle could be fundamental for the regulation of its own function. Here we examine the mechanistic role of cellular kinases in the fine regulation of key mitochondrial activities, including mitochondrial quality control, fission/fusion processes, metabolism, and mitophagy.

Functional Role of Mitochondria in Arrhythmogenesis.

Growing evidence indicate that mitochondria play a functional role in arrhythmogenesis. We report here the molecular mechanisms underlying the action of these highly dynamic organelles in the regulation of cell metabolism, action potential and, overall, heart excitability. In particular, we examine the role of cardiac mitochondria in linking metabolism and cell excitability. The importance of the main mitochondrial channels is evaluated as well, including the recently identified calcium uniporter. Promises and pitfalls of potential therapeutic strategies targeting mitochondrial pathways are also assessed.