Mitophagy Upregulation Occurs Early in the Neurodegenerative Process Mediated by α-Synuclein.

Parkinson's disease (PD) is a progressive neurogenerative movement disorder characterized by dopaminergic cell death within the substantia nigra pars compacta (SNpc) due to the aggregation-prone protein α-synuclein. Accumulation of α-synuclein is implicated in mitochondrial dysfunction and disruption of the autophagic turnover of mitochondria, or mitophagy, which is an essential quality control mechanism proposed to preserve mitochondrial fidelity in response to aging and stress. Yet, the precise relationship between α-synuclein accumulation, mitochondrial autophagy, and dopaminergic cell loss remains unresolved. Here, we determine the kinetics of α-synuclein overexpression and mitophagy using the pH-sensitive fluorescent mito-QC reporter. We find that overexpression of mutant A53T α-synuclein in either human SH-SY5Y cells or rat primary cortical neurons induces mitophagy. Moreover, the accumulation of mutant A53T α-synuclein in the SNpc of rats results in mitophagy dysregulation that precedes the onset of dopaminergic neurodegeneration. This study reveals a role for mutant A53T α-synuclein in inducing mitochondrial dysfunction, which may be an early event contributing to neurodegeneration.

Exercise rehabilitation in cardiac resynchronization: systematic review and a meta-analysis.

The benefit of exercise training in cardiac resynchronization therapy (CRT) recipients is not well established. We conducted a systematic review and meta-analysis to determine the effect of exercise training on clinical outcomes in CRT recipients.A comprehensive search until 2019 was conducted of MEDLINE, Epub, Embase, CINAHL and Cochrane databases as well as a bibliographic hand search to identify additional studies. We included all studies that compared aerobic exercise interventions in adults treated with CRT devices with adults treated with usual CRT care. These studies evaluated patient clinical characteristics, exercise testing measures, hemodynamic measures, echocardiography parameters, biomarkers and adverse events. Independent reviewers evaluated study eligibility, abstracted data and assessed risk of bias in duplicate. We used random-effect meta-analysis methods to estimate mean differences and odds ratios. Grades of Recommendation, Assessment, Development and Evaluation system were used to quantify absolute effects and quality of evidence. I2 was used to evaluate heterogeneity.We identified seven studies, six randomized control trials and one observational study, totaling 332 CRT patients in the exercise intervention and 534 patients receiving usual care. Peak VO2 was 2.4 ml/kg/min higher in the exercise group in comparison with the control group (pooled mean difference 2.26, 95% CI 1.38-3.13, I2 = 53%, high quality). AT-VO2 improved with exercise rehabilitation, and heterogeneity was considered low (pooled mean difference 3.96, 95% CI 2.68-5.24, I2 = 0.0%, moderate quality).Peak VO2 and AT-VO2 are increased with aerobic exercise in CRT recipients, demonstrating a significant improvement in functional capacity.

Can improvement in hormonal and energy balance reverse cardiovascular risk factors in athletes with amenorrhea?

Female athletes display a high prevalence of hypothalamic amenorrhea as a result of energy imbalance. In these athletes with amenorrhea, decreased luteinizing hormone/follicule-stimulating hormone secretion leads to deficiency in endogenous estrogen. The severe estrogen deficiency in these athletes may increase cardiovascular risk similar to that in postmenopausal women. This review discusses the potential cardiovascular risk factors in athletes with amenorrhea as a result of hypoestrogenism, which include endothelial dysfunction and unfavorable lipid profiles. We also consider the potential to reverse the cardiovascular risk by restoring energy or hormonal imbalance along the reproductive axis in athletes with amenorrhea.

Biomarkers of Inflammation, Fibrosis, and Acute Kidney Injury in Patients with Heart Failure with and without Left Ventricular Assist Device Implantation.

BACKGROUND/AIMS: Renal dysfunction or renal failure is a common complication in left ventricular assist device (LVAD) recipients and is associated with reduced survival. To date, serum creatinine and glomerular filtration rate (GFR) are used for the evaluation of kidney function. However, serum creatinine and GFR have limitations. The objective of our study is to assess the levels of kidney biomarkers in LVAD recipients compared to heart failure patients and healthy controls and to examine their association with conventional clinical biomarkers. METHODS: The biomarkers neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), plasminogen activator inhibitor-1 (PAI-1), and adiponectin were assessed in 51 participants: 19 heart failure patients, 16 LVAD recipients, and 16 healthy controls. Linear regressions were performed to assess whether demographic and clinical variables predict the levels of biomarkers that are associated with acute kidney injury and the risk of chronic kidney disease. RESULTS: The levels of NGAL and adiponectin were higher in LVAD recipients and patients with heart failure as compared with healthy controls. The levels of PAI-1 and KIM-1 were not elevated in LVAD recipients. The results of linear regression analysis indicated that when controlling for the effect of CRP and BNP, 40.1% of the variance in NGAL levels can be explained by GFR (R2 = 0.401, F = 5.56, p = 0.005), while CRP can explain 35.3% of the variance in adiponectin levels (R2 = 0.353, F = 4.55, p = 0.01), when controlling for the effect of BNP and GFR. CONCLUSIONS: The levels of NGAL and adiponectin were augmented in LVAD recipients, suggesting that renal functions were not restored with circulatory support. Larger studies should assess the predictability of these biomarkers of renal dysfunction in LVAD recipients.

Effect of berberine on catecholamine levels in rats with experimental cardiac hypertrophy.

The aim of this study is to investigate the effect of berberine on catecholamine level (adrenaline and noradrenaline) in rats with experimental cardiac hypertrophy. Cardiac hypertrophy(CH) was induced by suprarenal abdominal aorta constriction, and the drugs were administered for 8 weeks starting from 4 weeks after surgery. The degree of cardiac hypertrophy was determined by heart and left ventricular weight. The level of adrenaline(AD) and noradrenaline(NA) was detected by HPLC. The data showed that in the CH model rats, the level of plasma and left ventricular tissue AD, and the level of NA in plasma were higher than that of the age-matched controls(indicating increased "total" sympathetic activity). The level of NA in left ventricular tissue of CH model rats was however lower than the age-matched controls. Berberine and captopril showed significant effect on inhibiting the development of cardiac hypertrophy. Berberine decreased plasma NA level and the AD level both in plasma and left ventricular tissue, but had no effect on improving the cardiac NA depletion. Captopril showed significant effect on increasing the depleted cardiac NA and in reducing the elevated plasma NA level. These findings show the efficacy of berberine on modulating the sympathetic nervous activity of rats with experimental cardiac hypertrophy, and reflect the therapeutic potentials of berberine in patients with cardiac hypertrophy and chronic heart failure.