Grb2 Induces Cardiorenal Syndrome Type 3: Roles of IL-6, Cardiomyocyte Bioenergetics, and Akt/mTOR Pathway

Proteomic Analysis of Prehypertensive and Hypertensive Patients: Exploring the Role of the Actin Cytoskeleton

Hypertension is a pervasive and widespread health condition that poses a significant risk factor for cardiovascular disease, which includes conditions such as heart attack, stroke, and heart failure. Despite its widespread occurrence, the exact cause of hypertension remains unknown, and the mechanisms underlying the progression from prehypertension to hypertension require further investigation. Recent proteomic studies have shown promising results in uncovering potential biomarkers related to disease development. In this study, serum proteomic data collected from Qatar Biobank were analyzed to identify altered protein expression between individuals with normal blood pressure, prehypertension, and hypertension and to elucidate the biological pathways contributing to this disease. The results revealed a cluster of proteins, including the SRC family, CAMK2B, CAMK2D, TEC, GSK3, VAV, and RAC, which were markedly upregulated in patients with hypertension compared to those with prehypertension (fold change ≥ 1.6 or ≤-1.6, area under the curve ≥ 0.8, and q-value < 0.05). Pathway analysis showed that the majority of these proteins play a role in actin cytoskeleton remodeling. Actin cytoskeleton reorganization affects various biological processes that contribute to the maintenance of blood pressure, including vascular tone, endothelial function, cellular signaling, inflammation, fibrosis, and mechanosensing. Therefore, the findings of this study suggest a potential novel role of actin cytoskeleton-related proteins in the progression from prehypertension to hypertension. The present study sheds light on the underlying pathological mechanisms involved in hypertension and could pave the way for new diagnostic and therapeutic approaches for the treatment of this disease.

Cardiorenal Syndrome Type 3 Review

The management of patients with complex comorbidity involving several organ systems can use an approach focused on each organ system independently or can use an approach trying to integrate various injuries and dysfunction into a single syndrome. Cardiorenal syndromes can develop with an initial injury to either the heart or kidney and then sequential involvement of the second organ. This can occur acutely or chronically. Cardiorenal syndrome type 3 is defined by acute renal injury with subsequent cardiac injury and/or dysfunction. Studies on these patients must use strict inclusion criteria. Pavan reported information on 100 patients with acute kidney injury in India to determine the frequency of cardiorenal syndrome type 3. He excluded patients with significant prior comorbidity. The most frequent causes of acute kidney injury in these patients were drug toxicity, gastroenteritis with volume contraction, and obstetrical complications. This study included 100 patients with acute kidney injury, and 29 developed cardiorenal syndrome type 3. Important outcomes included frequent mortality and chronic renal failure. Other studies have reported that cardiorenal syndrome type 3 occurs relatively infrequently. The analysis of large data bases has demonstrated that the development of acute kidney injury in hospitalized patients has important consequences, including the development of heart failure and increased mortality, but the complexity of these cohorts makes it difficult to determine the time course for the development of multisystem disorders. The pathogenesis of cardiorenal syndrome type 3 involves mitochondrial dysfunction, immune dysregulation, and ischemia-reperfusion. Cardiac events occur secondary to fluid overload, electrolyte disorders, and uremic toxins. These patients need increased attention during hospitalization and outpatient management in an effort to slow the progression of the primary disorder and treat complications.

Protein-protein interaction network-based integration of GWAS and functional data for blood pressure regulation analysis

BACKGROUND

It is valuable to analyze the genome-wide association studies (GWAS) data for a complex disease phenotype in the context of the protein-protein interaction (PPI) network, as the related pathophysiology results from the function of interacting polyprotein pathways. The analysis may include the design and curation of a phenotype-specific GWAS meta-database incorporating genotypic and eQTL data linking to PPI and other biological datasets, and the development of systematic workflows for PPI network-based data integration toward protein and pathway prioritization. Here, we pursued this analysis for blood pressure (BP) regulation.

METHODS

The relational scheme of the implemented in Microsoft SQL Server BP-GWAS meta-database enabled the combined storage of: GWAS data and attributes mined from GWAS Catalog and the literature, Ensembl-defined SNP-transcript associations, and GTEx eQTL data. The BP-protein interactome was reconstructed from the PICKLE PPI meta-database, extending the GWAS-deduced network with the shortest paths connecting all GWAS-proteins into one component. The shortest-path intermediates were considered as BP-related. For protein prioritization, we combined a new integrated GWAS-based scoring scheme with two network-based criteria: one considering the protein role in the reconstructed by shortest-path (RbSP) interactome and one novel promoting the common neighbors of GWAS-prioritized proteins. Prioritized proteins were ranked by the number of satisfied criteria.

RESULTS

The meta-database includes 6687 variants linked with 1167 BP-associated protein-coding genes. The GWAS-deduced PPI network includes 1065 proteins, with 672 forming a connected component. The RbSP interactome contains 1443 additional, network-deduced proteins and indicated that essentially all BP-GWAS proteins are at most second neighbors. The prioritized BP-protein set was derived from the union of the most BP-significant by any of the GWAS-based or the network-based criteria. It included 335 proteins, with ~ 2/3 deduced from the BP PPI network extension and 126 prioritized by at least two criteria. ESR1 was the only protein satisfying all three criteria, followed in the top-10 by INSR, PTN11, CDK6, CSK, NOS3, SH2B3, ATP2B1, FES and FINC, satisfying two. Pathway analysis of the RbSP interactome revealed numerous bioprocesses, which are indeed functionally supported as BP-associated, extending our understanding about BP regulation.

CONCLUSIONS

The implemented workflow could be used for other multifactorial diseases.

Dual-specificity phosphatase 1 interacts with prohibitin 2 to improve mitochondrial quality control against type-3 cardiorenal syndrome

Type-3 cardiorenal syndrome (CRS-3) is acute kidney injury followed by cardiac injury/dysfunction. Mitochondrial injury may impair myocardial function during CRS-3. Since dual-specificity phosphatase 1 (DUSP1) and prohibitin 2 (PHB2) both promote cardiac mitochondrial quality control, we assessed whether these proteins were dysregulated during CRS-3-related cardiac depression. We found that DUSP1 was downregulated in heart tissues from a mouse model of CRS-3. DUSP1 transgenic (DUSP1Tg) mice were protected from CRS-3-induced myocardial damage, as evidenced by their improved heart function and myocardial structure. CRS-3 induced the inflammatory response, oxidative stress and mitochondrial dysfunction in wild-type hearts, but not in DUSP1Tg hearts. DUSP1 overexpression normalized cardiac mitochondrial quality control during CRS-3 by suppressing mitochondrial fission, restoring mitochondrial fusion, re-activating mitophagy and augmenting mitochondrial biogenesis. We found that DUSP1 sustained cardiac mitochondrial quality control by binding directly to PHB2 and maintaining PHB2 phosphorylation, while CRS-3 disrupted this physiological interaction. Transgenic knock-in mice carrying the Phb2S91D variant were less susceptible to cardiac depression upon CRS-3, due to a reduced inflammatory response, suppressed oxidative stress and improved mitochondrial quality control in their heart tissues. Thus, CRS-3-induced myocardial dysfunction can be attributed to reduced DUSP1 expression and disrupted DUSP1/PHB2 binding, leading to defective cardiac mitochondrial quality control.

Network pharmacology and molecular docking to explore the mechanism of Sheng Xue Bao mixture against iron deficiency anemia

Based on network pharmacology and molecular docking, we investigated the mechanism of action of Sheng Xue Bao mixture (SXBM) in treating iron deficiency anemia (IDA). We screened the HERB and traditional Chinese medicine systems pharmacology database and analysis platform databases to identify the active ingredients and targets of SXBM. The targets associated with "iron deficiency anemia" were collected from GeneCards, TTD, and OMIM databases. A component-target interaction network was constructed using Cytoscape 3.8.2. The protein-protein interaction network of candidate targets was generated using the STRING database and visualized with Cytoscape 3.8.2 software. Core modules obtained from clustering analysis were subjected to Gene Ontology and Kyoto encyclopedia of genes and genomes enrichment analysis. Finally, molecular docking validation of key targets and active components was performed using Autodock Vina software. A total of 174 active components and 111 genes were identified as potential active components and targets for IDA treatment, including quercetin, kaempferol, luteolin, beta-sitosterol, and other flavonoids as main active components. Gene Ontology enrichment analysis show that interleaved genes are enriched in 2328 biological processes, 71 cellular component expression processes, and 157 molecular function processes. Kyoto encyclopedia of genes and genomes analysis mainly envolved Prostate cancer, Hepatitis B, Kaposi sarcoma-associated herpesvirus infection, Endocrine resistance, Lipid and atherosclerosis, Central carbon metabolism in cancer, Human cytomegalovirus infection and HIF-1 signaling pathway. STAT3, SRC, PIK3R1, and GRB2 were selected as core targets. The molecular docking results demonstrated strong interactions between key components and their respective target proteins. Network pharmacological analysis suggested that SXBM could treat IDA by regulating various biological processes and related signaling pathways. It laid the foundation for further elucidating the molecular mechanism of SXBM treatment of IDA.

Targeted VEGFA therapy in regulating early acute kidney injury and late fibrosis

Damage to peritubular capillaries is a key process that contributes to acute kidney injury (AKI) progression. Vascular endothelial growth factor A (VEGFA) plays a critical role in maintaining the renal microvasculature. However, the physiological role of VEGFA in various AKI durations remains unclear. A severe unilateral ischemia‒reperfusion injury model was established to provide an overview of VEGFA expression and the peritubular microvascular density from acute to chronic injury in mouse kidneys. Therapeutic strategies involving early VEGFA supplementation protecting against acute injury and late anti-VEGFA treatment for fibrosis alleviation were analyzed. A proteomic analysis was conducted to determine the potential mechanism of renal fibrosis alleviation by anti-VEGFA. The results showed that two peaks of extraglomerular VEGFA expression were observed during AKI progression: one occurred at the early phase of AKI, and the other occurred during the transition to chronic kidney disease (CKD). Capillary rarefaction progressed despite the high expression of VEGFA at the CKD stage, and VEGFA was associated with interstitial fibrosis. Early VEGFA supplementation protected against renal injury by preserving microvessel structures and counteracting secondary tubular hypoxic insults, whereas late anti-VEGFA treatment attenuated renal fibrosis progression. The proteomic analysis highlighted an array of biological processes related to fibrosis alleviation by anti-VEGFA, which included regulation of supramolecular fiber organization, cell-matrix adhesion, fibroblast migration, and vasculogenesis. These findings establish the landscape of VEGFA expression and its dual roles during AKI progression, which provides the possibility for the orderly regulation of VEGFA to alleviate early acute injury and late fibrosis.

NAC Pre-Administration Prevents Cardiac Mitochondrial Bioenergetics, Dynamics, Biogenesis, and Redox Alteration in Folic Acid-AKI-Induced Cardio-Renal Syndrome Type 3

The incidence of kidney disease is increasing worldwide. Acute kidney injury (AKI) can strongly favor cardio-renal syndrome (CRS) type 3 development. However, the mechanism involved in CRS development is not entirely understood. In this sense, mitochondrial impairment in both organs has become a central axis in CRS physiopathology. This study aimed to elucidate the molecular mechanisms associated with cardiac mitochondrial impairment and its role in CRS development in the folic acid-induced AKI (FA-AKI) model. Our results showed that 48 h after FA-AKI, the administration of N-acetyl-cysteine (NAC), a mitochondrial glutathione regulator, prevented the early increase in inflammatory and cell death markers and oxidative stress in the heart. This was associated with the ability of NAC to protect heart mitochondrial bioenergetics, principally oxidative phosphorylation (OXPHOS) and membrane potential, through complex I activity and the preservation of glutathione balance, thus preventing mitochondrial dynamics shifting to fission and the decreases in mitochondrial biogenesis and mass. Our data show, for the first time, that mitochondrial bioenergetics impairment plays a critical role in the mechanism that leads to heart damage. Furthermore, NAC heart mitochondrial preservation during an AKI event can be a valuable strategy to prevent CRS type 3 development.

Impaired microvascular circulation in distant organs following renal ischemia

Mortality in acute kidney injury (AKI) patients remains very high, although very important advances in understanding the pathophysiology and in diagnosis and supportive care have been made. Most commonly, adverse outcomes are related to extra-renal organ dysfunction and failure. We and others have documented inflammation in remote organs as well as microvascular dysfunction in the kidney after renal ischemia. We hypothesized that abnormal microvascular flow in AKI extends to distant organs. To test this hypothesis, we employed intravital multiphoton fluorescence imaging in a well-characterized rat model of renal ischemia/reperfusion. Marked abnormalities in microvascular flow were seen in every organ evaluated, with decreases up to 46% observed 48 hours postischemia (as compared to sham surgery, p = 0.002). Decreased microvascular plasma flow was found in areas of erythrocyte aggregation and leukocyte adherence to endothelia. Intravital microscopy allowed the characterization of the erythrocyte formations as rouleaux that flowed as one-dimensional aggregates. Observed microvascular abnormalities were associated with significantly elevated fibrinogen levels. Plasma flow within capillaries as well as microthrombi, but not adherent leukocytes, were significantly improved by treatment with the platelet aggregation inhibitor dipyridamole. These microvascular defects may, in part, explain known distant organ dysfunction associated with renal ischemia. The results of these studies are relevant to human acute kidney injury.

Autologous Extracellular Vesicles Attenuate Cardiac Injury in Experimental Atherosclerotic Renovascular Disease More Effectively Than Their Parent Mesenchymal Stem/Stromal Cells

Atherosclerotic renovascular disease (RVD) leads to hypertension, chronic kidney disease (CKD), and heart disease. Intrarenal delivery of mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (EVs) attenuate renal injury and suppress release of inflammatory cytokines in porcine RVD. We hypothesized that this strategy would also be useful for cardioprotection. Pigs with renovascular hypertension and metabolic syndrome were studied 4 weeks after treatment with a single intrarenal infusion of autologous MSCs, EVs, or vehicle. Cardiac structure and function were assessed in vivo, and myocardial remodeling and expression of the pro-fibrotic factor growth factor receptor-bound protein-2 (Grb2) were measured ex-vivo. Inflammatory cytokine levels were measured in the systemic circulation and myocardial tissue. Blood pressure was elevated in all RVD groups, but serum creatinine increased in RVD and decreased in both RVD + MSCs and RVD + EVs. RVD-induced diastolic dysfunction (lower E/A ratio) was normalized in both MSCs- and EVs- treated pigs. Intrarenal delivery of MSCs and EVs also attenuated RVD-induced myocardial fibrosis, collagen deposition, and Grb2 expression, yet EVs restored capillary density and inflammation more effectively than MSCs. These observations suggest that autologous EVs attenuate cardiac injury in experimental RVD more effectively than their parent MSCs.

Urinary insulin signaling pathway related proteins may serve as potential biomarkers for monitoring diabetes mellitus without hypertension and hyperlipidemia

The insulin signaling pathway plays an important role in the development of diabetes mellitus. The expression of insulin signaling pathway related proteins in the urine of diabetic patients has not been reported. The aim of this study was to analyze and verify the expression of insulin signaling pathway related proteins in the urine of diabetic patients without hypertension and hyperlipidemia, and to explore their clinical application value. Based on data-independent acquisition proteomics technology and bioinformatics, the urinary protein expression profile of diabetic patients without hypertension and hyperlipidemia was established. Western blot and enzyme-linked immunoassay were performed to verify the expression of insulin signaling pathway related proteins in the urine of diabetic patients. Sixteen proteins related to the insulin signaling pathway were screened in urine, and 7 of them were differentially expressed in the urine of diabetic patients without hypertension and hyperlipidemia. Further quantitative analysis showed that the downregulation of protein kinase CAMP-dependent type II regulatory subunit α, growth factor receptor bound protein 2, and guanine nucleotide-binding protein G(s) in the urine of diabetic patients without hyperlipidemia and hypertension was consistent with the preliminary screening results. In this exploratory study, we detected the expression of insulin signaling pathway related proteins in the urine of diabetic patients without hypertension and hyperlipidemia. protein kinase CAMP-dependent type II regulatory subunit α, growth factor receptor bound protein 2, and guanine nucleotide-binding protein G(s) in the urine of diabetic patients were downregulated, which was associated with diabetes. They may be promising noninvasive biomarkers for monitoring diabetes.

Cardiac effects of renal ischemia

Mortality in acute kidney injury (AKI) remains very high, yet the cause of death is often failure of extrarenal organs. We and others have demonstrated remote organ dysfunction after renal ischemia. The term "cardiorenal syndrome" was first applied to the "cross talk" between the organs by the National Heart, Lung, and Blood Institute of the National Institutes of Health, and the clinical importance is being increasingly appreciated. Nevertheless, more information is needed to effectively address the consequences of renal injury on the heart. Since AKI often occurs in patients with comorbidities, we investigated the effect of renal ischemia in the setting of existing cardiac failure. We hypothesized that the cardiac effects of renal ischemia would be significantly amplified in experimental cardiomyopathy. Male Sprague-Dawley rats with preexisting cardiac and renal injury due to low-dose doxorubicin were subjected to bilateral renal artery occlusion. Cardiac structure and function were examined 2 days after reperfusion. Loss of functional myocardial tissue with decreases in left ventricular pressure, increases in apoptotic cell death, inflammation, and collagen, and greater disruption in ultrastructure with mitochondrial fragmentation were seen in the doxorubicin/ischemia group compared with animals in the groups treated with doxorubicin alone or following ischemia alone. Systemic inflammation and cardiac abnormalities persisted for at least 21 wk. These results suggest that preexisting comorbidities can result in much more severe distant organ effects of acute renal injury. The results of this study are relevant to human AKI.NEW & NOTEWORTHY Acute kidney injury is common, expensive, and deadly, yet morbidity and mortality are often secondary to remote organ dysfunction. We hypothesized that the effects of renal ischemia would be amplified in the setting of comorbidities. Sustained systemic inflammation and loss of functional myocardium with significantly decreased systolic and diastolic function, apoptotic cell death, and increased collagen and inflammatory cells were found in the heart after renal ischemia in the doxorubicin cardiomyopathy model (vs. renal ischemia alone). Understanding the remote effects of renal ischemia has the potential to improve outcomes in acute kidney injury.

Empagliflozin activates Wnt/β-catenin to stimulate FUNDC1-dependent mitochondrial quality surveillance against type-3 cardiorenal syndrome

Objectives

Cardiorenal syndrome type-3 (CRS-3) is an abrupt worsening of cardiac function secondary to acute kidney injury. Mitochondrial dysfunction is a key pathological mechanism of CRS-3, and empagliflozin can improve mitochondrial biology by promoting mitophagy. Here, we assessed the effects of empagliflozin on mitochondrial quality surveillance in a mouse model of CRS-3.

Methods

Cardiomyocyte-specific FUNDC1-knockout (FUNDC1^CKO) mice were subjected to CRS-3 prior to assessment of mitochondrial homeostasis in the presence or absence of empagliflozin.

Results

CRS-3 model mice exhibited lower heart function, increased inflammatory responses and exacerbated myocardial oxidative stress than sham-operated controls; however, empagliflozin attenuated these alterations. Empagliflozin stabilized the mitochondrial membrane potential, suppressed mitochondrial reactive oxygen species production, increased mitochondrial respiratory complex activity and restored the oxygen consumption rate in cardiomyocytes from CRS-3 model mice. Empagliflozin also normalized the mitochondrial morphology, mitochondrial dynamics and mitochondrial permeability transition pore opening rate in cardiomyocytes. Cardiomyocyte-specific ablation of FUN14 domain-containing protein 1 (FUNDC1) in mice abolished the protective effects of empagliflozin on mitochondrial homeostasis and myocardial performance. Empagliflozin activated β-catenin and promoted its nuclear retention, thus increasing FUNDC1-induced mitophagy in heart tissues; however, a β-catenin inhibitor reversed these effects.

Conclusions

In summary, empagliflozin activated Wnt/β-catenin to stimulate FUNDC1-dependent mitochondrial quality surveillance, ultimately improving mitochondrial function and cardiac performance during CRS-3. Thus, empagliflozin could be considered for the clinical management of heart function following acute kidney injury.

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Empagliflozin reduces myocardial damage and improves myocardial function after CRS-3.

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Empagliflozin normalizes the mitochondrial structure in cardiomyocytes during CRS-3.

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Empagliflozin attenuates cardiomyocyte mitochondrial dysfunction during CRS-3.

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Empagliflozin activates FUNDC1-dependent mitophagy and preserves mitochondrial integrity in the heart during CRS-3.

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Loss of FUNDC1 abolishes the cardioprotective effects of empagliflozin during CRS-3.

Blockade of mIL‐6R alleviated lipopolysaccharide‐induced systemic inflammatory response syndrome by suppressing NF‐κB‐mediated Ccl2 expression and inflammasome activation

Systemic inflammatory response syndrome (SIRS) is characterized by dysregulated cytokine release, immune responses and is associated with organ dysfunction. IL‐6R blockade indicates promising therapeutic effects in cytokine release storm but still remains unknown in SIRS. To address the issue, we generated the human il‐6r knock‐in mice and a defined epitope murine anti‐human membrane‐bound IL‐6R (mIL‐6R) mAb named h‐mIL‐6R mAb. We found that the h‐mIL‐6R and the commercial IL‐6R mAb Tocilizumab significantly improved the survival rate, reduced the levels of TNF‐α, IL‐6, IL‐1β, IFN‐γ, transaminases and blood urea nitrogen of LPS‐induced SIRS mice. Besides, the h‐mIL‐6R mAb could also dramatically reduce the levels of inflammatory cytokines in LPS‐treated THP‐1 cells in vitro. RNA‐seq analysis indicated that the h‐mIL‐6R mAb could regulate LPS‐induced activation of NF‐κB/Ccl2 and NOD‐like receptor signaling pathways. Furthermore, we found that the h‐mIL‐6R mAb could forwardly inhibit Ccl2 expression and NLRP3‐mediated pyroptosis by suppressing NF‐κB in combination with the NF‐κB inhibitor. Collectively, mIL‐6R mAbs suppressed NF‐κB/Ccl2 signaling and inflammasome activation. IL‐6R mAbs are potential alternative therapeutics for suppressing excessive cytokine release, over‐activated inflammatory responses and alleviating organ injuries in SIRS.

Mitochondrial Dysfunction: An Emerging Link in the Pathophysiology of Cardiorenal Syndrome

The crosstalk between the heart and kidney is carried out through various bidirectional pathways. Cardiorenal syndrome (CRS) is a pathological condition in which acute or chronic dysfunction in the heart or kidneys induces acute or chronic dysfunction of the other organ. Complex hemodynamic factors and biochemical and hormonal pathways contribute to the development of CRS. In addition to playing a critical role in generating metabolic energy in eukaryotic cells and serving as signaling hubs during several vital processes, mitochondria rapidly sense and respond to a wide range of stress stimuli in the external environment. Impaired adaptive responses ultimately lead to mitochondrial dysfunction, inducing cell death and tissue damage. Subsequently, these changes result in organ failure and trigger a vicious cycle. In vitro and animal studies have identified an important role of mitochondrial dysfunction in heart failure (HF) and chronic kidney disease (CKD). Maintaining mitochondrial homeostasis may be a promising therapeutic strategy to interrupt the vicious cycle between HF and acute kidney injury (AKI)/CKD. In this review, we hypothesize that mitochondrial dysfunction may also play a central role in the development and progression of CRS. We first focus on the role of mitochondrial dysfunction in the pathophysiology of HF and AKI/CKD, then discuss the current research evidence supporting that mitochondrial dysfunction is involved in various types of CRS.

Mitochondrial Bioenergetic and Proteomic Phenotyping Reveals Organ-Specific Consequences of Chronic Kidney Disease in Mice

Chronic kidney disease (CKD) results in reduced kidney function, uremia, and accumulation of uremic metabolites. Mitochondrial alterations have been suggested to play a role in the disease pathology within various tissues. The purpose of this study was to perform a comprehensive bioenergetic and proteomic phenotyping of mitochondria from skeletal muscle (SkM), cardiac muscle (CM), and renal tissue from mice with CKD. The 5-month-old C57BL/6J male mice were fed a casein control or adenine-supplemented diet for 6 months. CKD was confirmed by blood urea nitrogen. A mitochondrial diagnostic workflow was employed to examine respiratory function, membrane and redox potential, reactive oxygen species production, and maximal activities of matrix dehydrogenases and electron transport system (ETS) protein complexes. Additionally, tandem-mass-tag-assisted proteomic analyses were performed to uncover possible differences in mitochondrial protein abundance. CKD negatively impacted mitochondrial energy transduction (all p < 0.05) in SkM, CM, and renal mitochondria, when assessed at physiologically relevant cellular energy demands (ΔGATP) and revealed the tissue-specific impact of CKD on mitochondrial health. Proteomic analyses indicated significant abundance changes in CM and renal mitochondria (115 and 164 proteins, p < 0.05), but no differences in SkM. Taken together, these findings reveal the tissue-specific impact of chronic renal insufficiency on mitochondrial health.