Background/Objectives: This review summarizes and analyzes current data on the toxicological effects of cerium dioxide nanoparticles (nanoceria) on various anatomical and functional systems in healthy murine models, as reported in both in vivo and ex vivo experimental settings. Methods: This systematic review was conducted and reported in accordance with the PRISMA 2020 guidelines and was prospectively registered in PROSPERO (CRD42024503240). A systematic literature search was conducted using the PubMed and ScienceDirect databases for the period 2019–2025, with the inclusion of earlier publications having significant scientific relevance. The final search update was conducted in July 2025 to ensure inclusion of the most recent studies. Results and Conclusions: Only in vivo and ex vivo studies in healthy murine models were included. Risk of bias was evaluated using the OHAT tool for animal studies, and data were synthesized narratively due to heterogeneity among studies. A total of 29 studies met the inclusion criteria. The pharmacokinetic properties of nanoceria were considered, encompassing biodistribution, elimination pathways (including oral, intravenous, intraperitoneal, inhalation, intratracheal, and instillation routes), and the influence of physicochemical characteristics on bioavailability and toxicity. The toxicological impact (TI) was assessed across major organ systems—respiratory, digestive, urinary, visual, reproductive, nervous, cardiovascular, immune, hematopoietic, endocrine, musculoskeletal, and skin. The liver, spleen, lungs, and kidneys were identified as primary accumulation sites, with clearance dependent on particle size and coating. The TI spectrum ranged from the absence of morphological changes to inflammation, fibrosis, or organ dysfunction, depending on dose, exposure route, and physicochemical parameters. The main limitations include variability of nanoparticle formulations and incomplete toxicity reporting. In general, CeO₂ nanoparticles with sizes of 2–10 nm and doses ≤ 5 mg/kg showed no signs of systemic toxicity in short-term studies on healthy mice, provided that optimal coating and dosing intervals were used.

In recent times, there has been a significant increase in researchers’ interest in the functions of microRNAs and the role of these molecules in the pathogenesis of many multifactorial diseases. This is related to the diagnostic and prognostic potential of microRNA expression levels as well as the prospects of using it in personalized targeted therapy. This review of the literature analyzes existing scientific data on the involvement of microRNAs in the molecular and cellular mechanisms underlying the development of pathologies such as Alzheimer’s disease, cerebral ischemia and reperfusion injury, and dysfunction of the blood–brain barrier.

The review discusses the potential relationship between hypoxia resistance and longevity, the influence of carbon dioxide on the mechanisms of aging of the mammalian organism, and intermittent hypercapnic–hypoxic effects on the signaling pathways of aging mechanisms. In the article, we focused on the potential mechanisms of the gero-protective efficacy of carbon dioxide when combined with hypoxia. The review summarizes the possible influence of intermittent hypoxia and hypercapnia on aging processes in the nervous system. We considered the perspective variants of the application of hypercapnic–hypoxic influences for achieving active longevity and the prospects for the possibilities of developing hypercapnic–hypoxic training methods.

In this study, the neurorehabilitation potential of combined and isolated intermittent hypercapnia and hypoxia exposure was evaluated following photochemically induced cerebral thrombosis in rats. Particular attention was given to the roles of possible neuroplasticity mechanisms mediated by VEGF and BDNF, as well as the potential of hypercapnic–hypoxic interventions to synergistically amplify the therapeutic effects of pharmacological neuroprotectants during recovery. A total of 50 male Wistar rats were randomly assigned to five equal groups (n = 10 per group), each undergoing a course of respiratory interventions lasting 30 min per day for 15 sessions. The groups included (1) a normobaric hypoxia (PO₂ ≈ 90 mmHg) group, (2) a permissive hypercapnia (PCO₂ ≈ 50 mmHg) group, (3) a combined hypercapnic hypoxia (PO₂ ≈ 90 mmHg, PCO₂ ≈ 50 mmHg) group, (4) a control group, and (5) a sham-operated group. Following the rehabilitation protocol, animals exposed to hypercapnic hypoxia exhibited a two-fold reduction in stroke volume compared with controls, significant improvement in motor coordination (as assessed via the rotarod test), and marked upregulation of VEGF and BDNF expression within the ischemic brain region. Notably, only the HH group showed a decrease in serum neuron-specific enolase (NSE) levels. These findings indicate that hypercapnic hypoxia exerts a possible neurorehabilitative effect after focal ischemic injury, superior to that of isolated hypoxia or hypercapnia. Possible mechanisms underlying this outcome may involve activation of neurotrophic (BDNF) and angiogenic (VEGF) signaling pathways.

A 60-year-old male with hypertrophic cardiomyopathy, conduction disorders, post-COVID-19 myopericarditis and heart failure was admitted to the hospital’s cardiology department. Blood tests revealed an increase in CPK activity, troponin T elevation and high titers of anticardiac antibodies. Whole exome sequencing showed the presence of the pathogenic variant NM_213599:c.2272C>T of the ANO5 gene. Results of the skeletal muscle biopsy excluded the diagnosis of systemic amyloidosis. Microscopy of the muscle fragment demonstrated sclerosis of the perimysium, moderate lymphoid infiltration, sclerosis of the microvessels, dystrophic changes and a lack of cross striations in the muscle fibers. Hypertrophy of the LV with a low contractile ability, atrial fibrillation, weakness of the distal skeletal muscles and increased plasma CPK activity and the results of the skeletal muscle biopsy suggested a diagnosis of a late form of distal myopathy (Miyoshi-like distal myopathy, MMD3). Post-COVID-19 myopericarditis, for which genetically modified myocardium could serve as a favorable background, caused heart failure decompensation.