Federica Galloso

Chronic kidney disease (CKD) represents a major global health challenge, affecting more than 10% of the population and contributing substantially to morbidity and premature mortality. Growing evidence identifies oxidative stress and mitochondrial dysfunction as central drivers of renal injury and disease progression across diverse etiologies. The kidney is one of the most mitochondria-rich organs in the body, reflecting the high bioenergetic demands required for tubular reabsorption and metabolic homeostasis. Disruption of mitochondrial oxidative phosphorylation, excessive production of reactive oxygen species (ROS), and impaired mitochondrial quality control mechanisms promote tubular injury, inflammation, and fibrosis. In particular, dysfunction of the electron transport chain, activation of NADPH oxidase isoforms—especially NOX4—and alterations in mitochondrial dynamics create a vicious cycle of oxidative damage and bioenergetic failure. Emerging evidence highlights the importance of mitochondrial quality control pathways, including fusion–fission balance, PINK1/Parkin-mediated mitophagy, and mitochondrial biogenesis regulated by PGC-1α and TFAM. Additional mechanisms include ferroptosis, epigenetic regulation, mitochondrial DNA-mediated innate immune activation, and Na⁺/K⁺-ATPase-linked redox signaling. At the translational level, redox and mitochondrial biomarkers and targeted therapies are biologically compelling, but the evidence is uneven: most candidate biomarkers remain insufficiently standardized, and direct mitochondria-targeted interventions are supported predominantly by preclinical studies or small human proof-of-concept trials. This review therefore emphasizes not only mechanistic advances but also conflicting findings, model limitations, and the barriers that currently separate experimental efficacy from clinically meaningful CKD outcomes.

Chronic kidney disease (CKD) represents a major global health challenge, affecting more than 10% of the population and contributing substantially to morbidity and premature mortality. Growing evidence identifies oxidative stress and mitochondrial dysfunction as central drivers of renal injury and disease progression across diverse etiologies. The kidney is one of the most mitochondria-rich organs in the body, reflecting the high bioenergetic demands required for tubular reabsorption and metabolic homeostasis. Disruption of mitochondrial oxidative phosphorylation, excessive production of reactive oxygen species (ROS), and impaired mitochondrial quality control mechanisms promote tubular injury, inflammation, and fibrosis. In particular, dysfunction of the electron transport chain, activation of NADPH oxidase isoforms—especially NOX4—and alterations in mitochondrial dynamics create a vicious cycle of oxidative damage and bioenergetic failure. Emerging evidence highlights the importance of mitochondrial quality control pathways, including fusion–fission balance, PINK1/Parkin-mediated mitophagy, and mitochondrial biogenesis regulated by PGC-1α and TFAM. Recent studies have also identified additional mechanisms linking mitochondrial dysfunction to CKD progression, including ferroptosis, epigenetic regulation of mitochondrial genes, and mitochondrial DNA release acting as damage-associated molecular patterns that activate innate immune pathways. At the clinical level, redox and mitochondrial biomarkers—such as F2-isoprostanes, 8-hydroxy-2′-deoxyguanosine, advanced oxidation protein products, and circulating mitochondrial DNA—may improve early diagnosis and risk stratification. Therapeutically, both established nephroprotective drugs and emerging mitochondria-targeted interventions aim to restore mitochondrial homeostasis and represent promising strategies for slowing CKD progression.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by the loss of self-tolerance to nuclear and cytoplasmic antigens, triggering immune activation and tissue inflammation. Lupus nephritis (LN) is a major determinant of disease-related morbidity, disability, chronic kidney disease progression, kidney failure, and mortality in SLE, affecting approximately 30% of patients at diagnosis and up to 50–60% within the first decade. This review examines the disease’s pathogenic mechanisms, emphasizing the innate immune system’s role in the loss of self-tolerance and subsequent activation of the adaptive immune response. Mechanisms include dysregulated cell death pathways, impaired clearance of nucleic acid-containing debris and immune complexes, and involvement of antigen-presenting cells and other innate immune cells. These processes lead to the clonal expansion of autoreactive lymphocytes, generating effector T cells, memory B cells, and plasma cells that produce autoantibodies, resulting in renal injury. The review further explores the immunological processes driving kidney damage, beginning with autoantibody binding and immune complex deposition, followed by complement-mediated microvascular injury, kidney stromal cell activation, and leukocyte recruitment. Lastly, it discusses LN treatment strategies, from traditional to novel targeted therapies, with a focus on their systemic immunologic impacts and the protection of podocytes.