Visualizing Pyrazinamide Action by Live Single-Cell Imaging of Phagosome Acidification and Mycobacterium tuberculosis pH Homeostasis.

Mycobacterium tuberculosis segregates within multiple subcellular niches with different biochemical and biophysical properties that, upon treatment, may impact antibiotic distribution, accumulation, and efficacy. However, it remains unclear whether fluctuating intracellular microenvironments alter mycobacterial homeostasis and contribute to antibiotic enrichment and efficacy. Here, we describe a live dual-imaging approach to monitor host subcellular acidification and M. tuberculosis intrabacterial pH. By combining this approach with pharmacological and genetic perturbations, we show that M. tuberculosis can maintain its intracellular pH independently of the surrounding pH in human macrophages. Importantly, unlike bedaquiline (BDQ), isoniazid (INH), or rifampicin (RIF), the drug pyrazinamide (PZA) displays antibacterial efficacy by disrupting M. tuberculosis intrabacterial pH homeostasis in cellulo. By using M. tuberculosis mutants, we confirmed that intracellular acidification is a prerequisite for PZA efficacy in cellulo. We anticipate this imaging approach will be useful to identify host cellular environments that affect antibiotic efficacy against intracellular pathogens. IMPORTANCE We still do not completely understand why tuberculosis (TB) treatment requires the combination of several antibiotics for up to 6 months. M. tuberculosis is a facultative intracellular pathogen, and it is still unknown whether heterogenous and dynamic intracellular populations of bacteria in different cellular environments affect antibiotic efficacy. By developing a dual live imaging approach to monitor mycobacterial pH homeostasis, host cell environment, and antibiotic action, we show here that intracellular localization of M. tuberculosis affects the efficacy of one first-line anti-TB drug. Our observations can be applicable to the treatment of other intracellular pathogens and help to inform the development of more effective combined therapies for tuberculosis that target heterogenous bacterial populations within the host

Azilsartan and chlorthalidone-new powerful fixed dose antihypertensive combination

Arterial hypertension is a disease that still affects a major part of the population worldwide, and leads to fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarc-tions. From the CDC statistical analysis, as regarding to United States, 1 of every 3 adults has high blood pressure, and οnly about half (54%) of them have it under control. Furthermore, all that leads to a nation cost about $46 billion each year. Efforts to find new ways to regulate arterial hypertension are therefore imperative. In our days, a lot of references have been made to the use of a new therapeutic combination, that of azilsartan – an innovative ARB, in combination with chlorthalidone. Ιn fact, it is a combination now prescribed in a number of countries. A significant number of trials shows both azilsartan vs popular antihypertensive drugs, as well as chlorthalidone vs chlorothiazide, to present a better antihypertensive effect. This effect is even greater when the two substances are combined. In this article, we will try to present the latest findings concerning the efficacy, safety and clinical utility of this combination, as well as its adverse events, in comparison with other widely used therapeutic options. © 2018 Bentham Science Publishers

Imaging modalities for cardiovascular phenotyping in asymptomatic people living with HIV

Cardiovascular disease (CVD) has emerged as a leading cause of non-HIV-related mortality among people living with HIV (PLWH). Despite the growing CVD burden in PLWH, there is concern that general population risk score models may underestimate CVD risk in these patients. Imaging modalities have received mounting attention lately to better understand the pathophysiology of subclinical CVD and provide improved risk assessment in this population. To date, traditional and well-established techniques such as echocardiography, pulse wave velocity, and carotid intima thickness continue to be the basis for the diagnosis and subsequent monitoring of vascular atherosclerosis and heart failure. Furthermore, novel imaging tools such as cardiac computed tomography (CT) and cardiac CT angiography (CCTA), positron emission tomography/CT (PET/CT), and cardiac magnetic resonance (CMR) have provided new insights into accelerated cardiovascular abnormalities in PLWH and are currently evaluated with regards to their potential to improve risk stratification. © The Author(s) 2021

ATG7 and ATG14 restrict cytosolic and phagosomal Mycobacterium tuberculosis replication in human macrophages.

Autophagy is a cellular innate-immune defence mechanism against intracellular microorganisms, including Mycobacterium tuberculosis (Mtb). How canonical and non-canonical autophagy function to control Mtb infection in phagosomes and the cytosol remains unresolved. Macrophages are the main host cell in humans for Mtb. Here we studied the contributions of canonical and non-canonical autophagy in the genetically tractable human induced pluripotent stem cell-derived macrophages (iPSDM), using a set of Mtb mutants generated in the same genetic background of the common lab strain H37Rv. We monitored replication of Mtb mutants that are either unable to trigger canonical autophagy (Mtb ΔesxBA) or reportedly unable to block non-canonical autophagy (Mtb ΔcpsA) in iPSDM lacking either ATG7 or ATG14 using single-cell high-content imaging. We report that deletion of ATG7 by CRISPR-Cas9 in iPSDM resulted in increased replication of wild-type Mtb but not of Mtb ΔesxBA or Mtb ΔcpsA. We show that deletion of ATG14 resulted in increased replication of both Mtb wild type and the mutant Mtb ΔesxBA. Using Mtb reporters and quantitative imaging, we identified a role for ATG14 in regulating fusion of phagosomes containing Mtb with lysosomes, thereby enabling intracellular bacteria restriction. We conclude that ATG7 and ATG14 are both required for restricting Mtb replication in human macrophages

Subclinical Left Ventricular Systolic Dysfunction in HIV Patients: Prevalence and Associations with Carotid Atherosclerosis and Increased Adiposity

Background: Human immunodeficiency virus (HIV) is mainly detected in young, otherwise healthy, individuals. Cardiomyopathy and peripheral artery disease affecting these patients appears to be multifactorial. Prompt and potentially more effective implementation of therapeutic measures could be enabled by pre‐symptomatic diagnosis of myocardial dysfunction and peripheral artery damage. However, limited data is available to date on this specific topic. Μethods: We investigated the association between global longitudinal strain (GLS), an established index of subclinical left ventricular systolic dysfunction (LVSD) assessed by two‐dimensional speckle‐tracking echocardiography, and: (a) patient history; (b) demographic and clinical baseline characteristics; (c) carotid intima‐media thickness (IMT) and the presence of carotid atherosclerotic plaque(s), measured by ultrasonography; (d) temperature difference (ΔT) along each carotid artery, measured by microwave radiometry; and (e) basic blood panel measurements, including high-sensitivity troponin‐T (hsTnT) and NT‐proBNP in people living with HIV (PLWH) and no history of cardiovascular disease. Results: We prospectively enrolled 103 consecutive PLWH (95% male, age 47 ± 11 years, anti‐retroviral therapy 100%) and 52 age‐ and sex‐matched controls. PLWH had a significantly higher relative wall thickness (0.38 ± 0.08 vs. 0.36 ± 0.04, p = 0.048), and higher rate of LVSD (34% vs. 15.4%, p = 0.015), and carotid artery atherosclerosis (28% vs. 6%, p = 0.001) compared with controls. Among PLWH, LVSD was independently associated with the presence of carotid atherosclerosis (adj. OR:3.09; 95%CI:1.10–8.67, p = 0.032) and BMI (1.15; 1.03–1.29, p = 0.017), while a trend for association between LVSD and left ventricular hypertrophy was also noted (3.12; 0.73– 13.33, p = 0.124). No differences were seen in microwave radiometry parameters, NT‐proBNP, hs‐ TnT and c‐reactive protein between PLWH with and without LVSD. Conclusions: Subclinical LVSD and carotid atherosclerosis were significantly more frequent in PLWH compared to a group of healthy individuals, implying a possible link between HIV infection and these two pathological processes. Carotid atherosclerosis and increased adiposity were independently associated with impaired GLS in HIV‐infected individuals. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Arterial hypertension in patients under antineoplastic therapy: A systematic review

Background: Cardio-oncology aims to mitigate adverse cardiovascular manifestations in cancer survivors, but treatment-induced hypertension or aggravated hypertension has received less attention in these high cardiovascular risk patients. Methods: In this systematic review, we searched literature for contemporary data on the prevalence, pathophysiologic mechanisms, treatment implications and preventive strategies of hypertension in patients under antineoplastic therapy. Results: Several classes of antineoplastic drugs, including mainly vascular endothelial growth factor inhibitors, proteasome inhibitors, cisplatin derivatives, corticosteroids or radiation therapy were consistently associated with increased odds for new-onset hypertension or labile hypertensive status in previous controlled patients. Moreover, hypertension constitutes a major risk factor for chemotherapy-induced cardiotoxicity, which is the most serious cardiovascular adverse effect of antineoplastic therapy. Despite the heterogeneity of pooled studies, the pro-hypertensive profile of examined drug classes could be attributed to common structural and functional disorders. Importantly, certain antihypertensive drugs are considered to be more effective in the management of hypertension in this population and may partially attenuate indirect complications of cancer treatment, such as progressive development of cardiomyopathy and/or cardiovascular death. Nonpharmacological approaches to alleviate hypertension in cancer patients are also described, albeit adjudicated as less effective in general. Conclusion: A growing body of evidence suggests that multiple antineoplastic agents increase the rate of progression of hypertension. Physicians need to balance the life-saving cancer treatment and the inflated risk of adverse cardiovascular events due to suboptimal management of hypertension in order to achieve improved clinical outcomes and sustained survival for their patients. © 2019 Wolters Kluwer Health, Inc