Mitochondrial dysfunction in human immunodeficiency virus-1 transgenic mouse cardiac myocytes

HIV and Drug Use: A Tale of Synergy in Pulmonary Vascular Disease Development

Over the past two decades, with the advent and adoption of highly active anti-retroviral therapy, HIV-1 infection, a once fatal and acute illness, has transformed into a chronic disease with people living with HIV (PWH) experiencing increased rates of cardio-pulmonary vascular diseases including life-threatening pulmonary hypertension. Moreover, the chronic consequences of tobacco, alcohol, and drug use are increasingly seen in older PWH. Drug use, specifically, can have pathologic effects on the cardiovascular health of these individuals. The "double hit" of drug use and HIV may increase the risk of HIV-associated pulmonary arterial hypertension (HIV-PAH) and potentiate right heart failure in this population. This article explores the epidemiology and pathophysiology of PAH associated with HIV and recreational drug use and describes the proposed mechanisms by which HIV and drug use, together, can cause pulmonary vascular remodeling and cardiopulmonary hemodynamic compromise. In addition to detailing the proposed cellular and signaling pathways involved in the development of PAH, this article proposes areas ripe for future research, including the influence of gut dysbiosis and cellular senescence on the pathobiology of HIV-PAH. © 2023 American Physiological Society. Compr Physiol 13:4659-4683, 2023.

Human Immunodeficiency Virus Infection and Variation in Heart Failure Risk by Age, Sex, and Ethnicity: The HIV HEART Study

OBJECTIVES

To evaluate the risk of heart failure (HF) linked to human immunodeficiency virus (HIV) infection, how risk varies by demographic characteristics, and whether it is explained by atherosclerotic disease or risk factor treatment.

PATIENTS AND METHODS

We performed a retrospective cohort study of persons with HIV (PWHs) from January 1, 2000, through December 31, 2016, frequency-matched 1:10 to persons without HIV on year of entry, age, sex, race/ethnicity, and treating facility. We evaluated the risk of incident HF associated with HIV infection, overall and by left ventricular systolic function, and whether HF risk varied by demographic characteristics.

RESULTS

Among 38,868 PWHs and 386,586 matched persons without HIV, mean ± SD age was 41.4±10.8 years, with 12.3% female, 21.1% Black, 20.5% Hispanic, and 3.9% Asian/Pacific Islander. During median follow-up of 3.8 years (interquartile range, 1.4-9.0 years), the rate (per 100 person-years) of incident HF was 0.23 in PWHs vs 0.15 in those without HIV (P<.001). The PWHs had a higher adjusted HF rate (adjusted hazard ratio [aHR], 1.73; 95% confidence interval [CI], 1.57 to 1.91), which was only modestly attenuated after accounting for interim acute coronary syndrome events. Results were similar by systolic function category. The adjusted risk of HF in PWHs was more prominent for those 40 years and younger (aHR, 2.45; 95% CI, 1.92 to 3.03), women (aHR, 2.48; 95% CI, 1.90 to 3.26), and Asian/Pacific Islanders (aHR, 2.46; 95% CI, 1.27 to 4.74).

CONCLUSION

HIV infection increases the risk of HF, which varied by demographic characteristics and was not primarily mediated through atherosclerotic disease pathways or differential use of cardiopreventive medications.

SARS-CoV-2 infection enhances mitochondrial PTP complex activity to perturb cardiac energetics

SARS-CoV-2 is a newly identified coronavirus that causes the respiratory disease called coronavirus disease 2019 (COVID-19). With an urgent need for therapeutics, we lack a full understanding of the molecular basis of SARS-CoV-2-induced cellular damage and disease progression. Here, we conducted transcriptomic analysis of human PBMCs, identified significant changes in mitochondrial, ion channel, and protein quality-control gene products. SARS-CoV-2 proteins selectively target cellular organelle compartments, including the endoplasmic reticulum and mitochondria. M-protein, NSP6, ORF3A, ORF9C, and ORF10 bind to mitochondrial PTP complex components cyclophilin D, SPG-7, ANT, ATP synthase, and a previously undescribed CCDC58 (coiled-coil domain containing protein 58). Knockdown of CCDC58 or mPTP blocker cyclosporin A pretreatment enhances mitochondrial Ca2+ retention capacity and bioenergetics. SARS-CoV-2 infection exacerbates cardiomyocyte autophagy and promotes cell death that was suppressed by cyclosporin A treatment. Our findings reveal that SARS-CoV-2 viral proteins suppress cardiomyocyte mitochondrial function that disrupts cardiomyocyte Ca2+ cycling and cell viability.

A Link Between Methylglyoxal and Heart Failure During HIV-1 Infection

Early-onset heart failure (HF) continues to be a major cause of morbidity and mortality in people living with human immunodeficiency virus type one (HIV-1) infection (PLWH), yet the molecular causes for this remain poorly understood. Herein NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ humanized mice (Hu-mice), plasma from PLWH, and autopsied cardiac tissues from deceased HIV seropositive individuals were used to assess if there is a link between the glycolysis byproduct methylglyoxal (MG) and HF in the setting of HIV-1 infection. At five weeks post HIV infection, Hu-mice developed grade III-IV diastolic dysfunction (DD) with an associated two-fold increase in plasma MG. At sixteen-seventeen weeks post infection, cardiac ejection fraction and fractional shortening also declined by 26 and 35%, and plasma MG increased to four-fold higher than uninfected controls. Histopathological and biochemical analyses of cardiac tissues from Hu-mice 17 weeks post-infection affirmed MG increase with a concomitant decrease in expression of the MG-degrading enzyme glyoxalase-1 (Glo1). The endothelial cell marker CD31 was found to be lower, and coronary microvascular leakage and myocardial fibrosis were prominent. Increasing expression of Glo1 in Hu-mice five weeks post-infection using a single dose of an engineered AAV2/9 (1.7 × 10¹² virion particles/kg), attenuated the increases in plasma and cardiac MG levels. Increasing Glo1 also blunted microvascular leakage, fibrosis, and HF seen at sixteen weeks post-infection, without changes in plasma viral loads. In plasma from virally suppressed PLWH, MG was also 3.7-fold higher. In autopsied cardiac tissues from seropositive, HIV individuals with low viral log, MG was 4.2-fold higher and Glo1 was 50% lower compared to uninfected controls. These data show for the first time a causal link between accumulation of MG and HF in the setting of HIV infection.

Human immunodeficiency virus infection and risks of morbidity and death in adults with incident heart failure

AIMS

Human immunodeficiency virus (HIV) increases the risk of heart failure (HF), but whether it influences subsequent morbidity and mortality remains unclear.

METHODS AND RESULTS

We investigated the risks of hospitalization for HF, HF-related emergency department (ED) visits, and all-cause death in an observational cohort of incident HF patients with and without HIV using data from three large US integrated healthcare delivery systems. We estimated incidence rates and adjusted hazard ratios (aHRs) by HIV status at the time of HF diagnosis for subsequent outcomes. We identified 448 persons living with HIV (PLWH) and 3429 without HIV who developed HF from a frequency-matched source cohort of 38 868 PLWH and 386 586 without HIV. Mean age was 59.5 ± 11.3 years with 9.8% women and 31.8% Black, 13.1% Hispanic, and 2.2% Asian/Pacific Islander. Compared with persons without HIV, PLWH had similar adjusted rates of HF hospitalization [aHR 1.01, 95% confidence interval (CI): 0.81-1.26] and of HF-related ED visits [aHR 1.22 (95% CI: 0.99-1.50)], but higher adjusted rates of all-cause death [aHR 1.31 (95% CI: 1.08-1.58)]. Adjusted rates of HF-related morbidity and all-cause death were directionally consistent across a wide range of CD4 counts but most pronounced in the subset with a baseline CD4 count <200 or 200-499 cells/μL.

CONCLUSION

In a large, diverse cohort of adults with incident HF receiving care within integrated healthcare delivery systems, PLWH were at an independently higher risk of all-cause death but not HF hospitalizations or HF-related ED visits. Future studies investigating modifiable HIV-specific risk factors may facilitate more personalized care to optimize outcomes for PLWH and HF.

Mitochondria and ageing with HIV

PURPOSE OF REVIEW

Some older people living with HIV (PLWH) exhibit features of unsuccessful ageing, such as frailty. Mitochondrial dysfunction is one of the best characterized ageing mechanisms. There has been recent interest in whether some people ageing with HIV may have an excess of mitochondrial dysfunction. This review aims to address this question through: analogy with ageing and chronic disease; discussion of the key unknowns; suggested ways that measures of mitochondrial dysfunction might be incorporated into HIV research studies.

RECENT FINDINGS

Recent data suggest that mitochondrial dysfunction in PLWH may not be wholly a legacy effect of historical nucleoside analog reverse transcriptase inhibitor exposures. Research in the non-HIV setting has altered our understanding of the important mediators of mitochondrial dysfunction in ageing.

SUMMARY

Mitochondrial dysfunction is a very plausible driver of adverse ageing phenotypes in some older PLWH. As such it may be a target for therapeutic interventions. Currently, however, there remain considerable uncertainties around the extent of this phenomenon, and its relative importance. Current studies are likely to clarify these questions over the next few years.

Neuropeptide Y Induces Cardiomyocyte Hypertrophy via Attenuating miR-29a-3p in Neonatal Rat Cardiomyocytes

BACKGROUND

Neuropeptide Y (NPY) has been well known to induce Cardiomyocyte Hypertrophy (CH), which is possibly caused by disruption of cardiac cell energy balance. As mitochondria is losely related to energy metabolism, in this study, we investigated the changes in mitochondrial Dynamics-related protein (Drp1) expression under the action of NPY. miRNA-29a, a endogenous noncoding small molecule RNA which is involved in many cardiac diseases, by using a bioinformatics tool, we found a potential binding site of miRNA-29a on the Drp1 mRNA, and suggesting that miRNA-29a might play a regulatory role.

OBJECTIVE

To investigate the role of miR-29a-3p in the process of NPY-induced CH, and further explore it's predicted relationship with Drp1.

METHODS

The expression levels of miR-29a-3p and Atrial Natriuretic Peptide (ANP) were performed by the method of fluorescence quantitative PCR, in addition, expression of Drp1 in treated and control groups were performed by western blot analysis.] Results: We found NPY leads to the CH and up-regulation of ANP expression levels. We also found significant up-regulation of Drp1 expression and down-regulation of miR-29a-3p expression in NPY-treated cells. The decrease in miR-29a-3p expression may lead the increase expression level of Drp1. We found that the expression of ANP increased after NPY treatment. When Drp1 protein was silenced, the high expression of ANP was inhibited.

CONCLUSION

In this study, we found up-regulation of Drp1 in cells treated with NPY. Drp1 mRNA is a predicted target for miR-29a-3p, and the expression of Drp1 was attenuated by miR-29a-3p. Therefore, NPY leads to down-regulation of miR-29a-3p expression, up-regulation of Drp1 expression, and NPY leads to CH. Correspondingly, miR-29a-3p can counteract the effects of NPY. This may be a new way, which could be used in diagnosis and treatment plan for CH.

β-Arrestin-Biased AT1 Agonist TRV027 Causes a Neonatal-Specific Sustained Positive Inotropic Effect Without Increasing Heart Rate

The treatment of pediatric heart failure is a long-standing unmet medical need. Angiotensin II supports mammalian perinatal circulation by activating cardiac L-type Ca²⁺ channels through angiotensin type 1 receptor (AT₁R) and β-arrestin. TRV027, a β-arrestin-biased AT₁R agonist, that has been reported to be safe but not effective for adult patients with heart failure, activates the AT₁R/β-arrestin pathway. We found that TRV027 evokes a long-acting positive inotropic effect specifically on immature cardiac myocytes through the AT₁R/β-arrestin/L-type Ca²⁺ channel pathway with minimum effect on heart rate, oxygen consumption, reactive oxygen species production, and aldosterone secretion. Thus, TRV027 could be utilized as a valuable drug specific for pediatric heart failure.

Multiple Progressive Thermopreconditioning Improves Cardiac Ischemia/Reperfusion-induced Left Ventricular Contractile Dysfunction and Structural Abnormality in Rat

BACKGROUND

Triple progressive thermopreconditioning (3PTP) may induce high Hsp-70 expression to maintain cardiac function. We suggest that 3PTP may reduce myocardial ischemia/reperfusion (I/R) injury during organ transplantation through Bag3/Hsp-70 mediated defense mechanisms.

METHODS

Male Wistar rats were divided into sham control group and 72 h after 3PTP in a 42°C water bath (3PTP) group. Rats underwent 60 min of ischemia by occlusion of the left anterior descending coronary artery followed by 240 min reperfusion. Hemodynamic parameters, including the electrocardiogram, microcirculation, heart rate, left ventricular end-diastolic pressure, maximal rate of rise (+dp/dt), and fall (-dp/dt) in the left ventricular pressure for index of contraction and relaxation were determined. Myocardial infarct size was evaluated by the Evans blue-2,3,5-triphenyltetrazolium chloride method. 3PTP-induced protective mechanisms were determined by Western blot and immunohistochemistry.

RESULTS

Cardiac I/R depressed cardiac microcirculation, induced S-T segment elevation, and R-R and P-R interval elongation increased infarct size associated with erythrocyte extravasation, leukocytes and macrophage/monocyte infiltration, granulocyte colony-stimulating factor, poly(ADP-ribose) polymerase 1 stain, and transferase-mediated dUTP-biotin nick end labeling positive cells. However, 3PTP evoked significant cardioprotection against I/R injury, characterized by the increased +dp/dt value and the decreased elevated left ventricular end-diastolic pressure, erythrocyte extravasation, leukocyte and macrophage/monocyte infiltration, granulocyte colony-stimulating factor expression, poly(ADP-ribose) polymerase 1 expression, transferase-mediated dUTP-biotin nick end labeling positive cells, and fragmentation and infarct area. In addition, 3PTP increased Hsp-70 and Bag3 expression and decreased Bax/Bcl-2 ratio, but did not affect the Beclin-1 and LC3-II/LC3-I ratio in the heart with I/R injury.

CONCLUSIONS

3PTP therapies may through Bag3 upregulation alleviate I/R injury-induced left ventricular structural deterioration and dysfunction.

Come Together: Protein Assemblies, Aggregates and the Sarcostat at the Heart of Cardiac Myocyte Homeostasis

Homeostasis in vertebrate systems is contingent on normal cardiac function. This, in turn, depends on intricate protein-based cellular machinery, both for contractile function, as well as, durability of cardiac myocytes. The cardiac small heat shock protein (csHsp) chaperone system, highlighted by αB-crystallin (CRYAB), a small heat shock protein (sHsp) that forms ∼3–5% of total cardiac mass, plays critical roles in maintaining proteostatic function via formation of self-assembled multimeric chaperones. In this work, we review these ancient proteins, from the evolutionarily preserved role of homologs in protists, fungi and invertebrate systems, as well as, the role of sHsps and chaperones in maintaining cardiac myocyte structure and function. We propose the concept of the “sarcostat” as a protein quality control mechanism in the sarcomere. The roles of the proteasomal and lysosomal proteostatic network, as well as, the roles of the aggresome, self-assembling protein complexes and protein aggregation are discussed in the context of cardiac myocyte homeostasis. Finally, we will review the potential for targeting the csHsp system as a novel therapeutic approach to prevent and treat cardiomyopathy and heart failure.

Advances in the role and mechanism of BAG3 in dilated cardiomyopathy

The B cell lymphoma 2-associated anthanogene (BAG3) is an anti-apoptotic co-chaperone protein. Previous reports suggest that mutations in BAG3 are associated with dilated cardiomyopathy. This review aims to summarize the current understanding of the relationship between BAG3 mutations and dilated cardiomyopathy, primarily focusing on the role and protective mechanism of BAG3 in cardiomyocytes from individuals with dilated cardiomyopathy. The results of published studies show that BAG3 is critically important for reducing cardiomyocyte apoptosis, maintaining protein homeostasis, regulating mitochondrial stability, modulating myocardial contraction, and reducing cardiac arrhythmia, which suggests an indispensable protective mechanism of BAG3 in dilated cardiomyopathy. The significant role of BAG3 in protecting cardiomyocytes provides a new direction for the diagnosis and treatment of dilated cardiomyopathy. However, further research is required to explore the molecular mechanisms that regulate BAG3 expression, to identify a novel therapy for patients with dilated cardiomyopathy.

Sex-specific neurogenic deficits and neurocognitive disorders in middle-aged HIV-1 Tg26 transgenic mice

Varying degrees of cognitive deficits affect over half of all HIV-1 infected patients. Because of antiretroviral treatment (ART) regimens, the HIV-1 patient population is increasing in age. Very few epidemiological studies have focused on sex-specific differences in HIV-1-associated neurocognitive disorders (HAND). The purpose of this study is to examine any possible differences between male and female mice in the progression of cognitive dementia during persistent low-level HIV-1 protein exposure, mimicking the typical clinical setting in the post-ART era. Eight to ten-month old HIV-1 Tg26(+/-) transgenic mice were utilized to assess for specific learning and memory modalities. Initial physiological screening and fear conditioning assessments revealed that Tg26 mice exhibited no significant differences in general behavioral function, contextual fear conditioning, or cued fear conditioning responses when compared to their wild-type (WT) littermates, regardless of sex. However, Barnes maze testing revealed significantly impaired short and long-term spatial memory in males, while females had impaired spatial learning abilities and short-term spatial memory. The potential cellular mechanism underlying these sex-specific neurocognitive deficits was explored with hippocampal neurogenic analysis. Compared to WT mice, both male and female Tg26(+/-) mice had fewer quiescent neural stem cells and neuroblasts in their hippocampi. Male Tg26(+/-) mice had a more robust reduction of the quiescent neural stem cell pool than female Tg26(+/-) mice. While female WT mice had a higher number of neural progenitor cells than male WT mice, only female Tg26(+/-) mice exhibited a robust reduction in the number of neural progenitor cells. Altogether, these results suggest that middle-aged male and female Tg26(+/-) mice manifest differing impairments in cognitive functioning and hippocampal neurogenesis. This study emphasizes the importance of understanding sex related differences in HAND pathology, which would aid in designing more optimized therapeutic regimens for the treatment of HAND.