Experimental Renovascular Disease Induces Endothelial Cell Mitochondrial Damage and Impairs Endothelium-Dependent Relaxation of Renal Artery Segments

Human Obesity Attenuates Cardioprotection Conferred by Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells

To explore the impact of obesity on reparative potency of adipose tissue-derived mesenchymal stromal/stem cells (A-MSC) in hypertensive cardiomyopathy, A-MSC were harvested from subcutaneous fat of obese and age-matched non-obese human subjects during bariatric or kidney donation surgeries, and then injected into mice 2 weeks after inducing renovascular hypertension (RVH) or sham surgery. Two weeks later, left ventricular (LV) function and deformation were estimated in vivo by micro-magnetic resonance imaging and myocardial damage ex vivo. Blood pressure and myocardial wall thickening were elevated in RVH + Vehicle and normalized only by lean-A-MSC. Both A-MSC types reduced LV mass and normalized the reduced LV peak strain radial in RVH, yet obese-A-MSC also impaired LV systolic function. A-MSC alleviated myocardial tissue damage in RVH, but lean-A-MSC decreased oxidative stress more effectively. Obese-A-MSC also showed increased cellular inflammation in vitro. Therefore, obese-A-MSC are less effective than lean-A-MSC in blunting hypertensive cardiomyopathy in mice with RVH.

Renal involvement is frequent in adults with primary mitochondrial disorders: an observational study

Background

Mitochondrial functions are controlled by genes of both mitochondrial and nuclear DNA. Pathogenic variants affecting any of these are responsible for primary mitochondrial disorders (MIDs), which can be diagnosed during adulthood. Kidney functions are highly dependent on mitochondrial respiration. However, the prevalence of MID-associated nephropathies (MIDANs) is unknown in the adult population. We aimed to address this point and to provide a full characterization of MIDANs in this population.

Methods

We retrospectively included for observational study adults (≥16 years of age) with genetically diagnosed MID between 2000 and 2020 in our tertiary care academic centre when they had a chronic kidney disease (CKD) evaluation. MIDANs were ascertained by CKD occurring in MIDs. The phenotypic, biological, histopathological and genotypic characteristics were recorded from the medical charts.

Results

We included 80 MID-affected adults and ascertained MIDANs in 28/80 (35%). Kidney diseases under the care of a nephrologist occurred in only 14/28 (50%) of the adults with MIDAN. MIDANs were tubulointerstitial nephropathy in 14/28 patients (50%) and glomerular diseases in 9/28 (32.1%). In adults with MID, MIDAN was negatively associated with higher albumin levels {odds ratio [OR] 0.79 [95% confidence interval (CI) 0.67-0.95]} and vision abnormalities [OR 0.17 (95% CI 0.03-0.94)] and positively associated with hypertension [OR 4.23 (95% CI 1.04-17.17)].

Conclusion

MIDANs are frequent among adult MIDs. They are mostly represented by tubulointerstitial nephropathy or glomerular disease. Vision abnormalities, hypertension and albumin levels were independently associated with MIDANs. Our results pave the way for prospective studies investigating the prevalence of MIDANs among undetermined kidney disease populations.

PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity

T-2 toxin can cause mitochondrial impairment and subsequent renal damage. PINK1/Parkin-mediated mitophagy can mitigate renal impairment by alleviating mitochondrial damage. Nevertheless, the impact of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced renal injury remains unclear. Here, we studied the role of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced nephrotoxicity. Mitochondrial damage was accompanied by NLRP3-inflammasome activation and PINK1/Parkin-mediated mitophagy in the kidney of T-2 toxin-exposed C57BL/6N mice. Knocking out Parkin inhibited the mitophagy but aggravated the structural and functional damage, NLRP3-inflammasome activation, mitochondrial damage, and apoptosis. Correlation analysis revealed that NLRP3-inflammasome activation was correlated with apoptosis. These results show that PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity.

Emergent players in renovascular disease

Renovascular disease (RVD) remains a common etiology of secondary hypertension. Recent clinical trials revealed unsatisfactory therapeutic outcomes of renal revascularization, leading to extensive investigation to unravel key pathophysiological mechanisms underlying irreversible functional loss and structural damage in the chronically ischemic kidney. Research studies identified complex interactions among various players, including inflammation, fibrosis, mitochondrial injury, cellular senescence, and microvascular remodeling. This interplay resulted in a shift of our understanding of RVD from a mere hemodynamic disorder to a pro-inflammatory and pro-fibrotic pathology strongly influenced by systemic diseases like metabolic syndrome (MetS), hypertension, diabetes mellitus, and hyperlipidemia. Novel diagnostic approaches have been tested for early detection and follow-up of RVD progression, using new imaging techniques and biochemical markers of renal injury and dysfunction. Therapies targeting some of the pathological pathways governing the development of RVD have shown promising results in animal models, and a few have moved from bench to clinical research. This review summarizes evolving understanding in chronic ischemic kidney injury.