Mitochondria are of great importance in cell biology since they are major sites of adenosine triphosphate (ATP) production and are widely involved in different cellular pathways involved in the response to stress. During ATP production, reactive oxygen species (ROS) can be produced. While a small amount of ROS may be important for the regulation of physiological processes, at elevated levels they can turn into harmful agents leading to cellular damage. From a pathological perspective, it could be particularly interesting to focus on mitochondrial function in endothelial cells since they may be involved in the development of aging and in the onset of different diseases, including renal, cardio-metabolic, liver and neurodegenerative ones. However, to date, there are no surveys which address the above issues. To fill this gap, it may be valuable to collect recent findings about the role of mitochondria in the regulation of endothelial function, not only to increase knowledge about it but also for clinical applications. Here, we overview the most recent knowledge about the above issues in the view of characterizing the role of mitochondria in endothelial cells as an innovative potential target for the prevention of aging, as well as the treatment of the above pathological conditions.

Nitric oxide (NO), a fundamental gaseous signaling molecule, is indispensable for cardiovascular homeostasis. This review synthesizes the expansive field of NO biology within the unifying framework of Nitric Oxide Equilibrium (NOE), i.e., the critical balance between its synthesis, bioavailability, and degradation. In a physiological state, NOE maintains vascular health by regulating blood pressure, preventing thrombosis, suppressing inflammation, and optimizing both cardiac and mitochondrial function. Here, we analyze how NOE disruption, primarily through oxidative stress and enzymatic dysfunction, underlies the pathogenesis of major cardiovascular diseases, including atherosclerosis, heart failure, ischemia–reperfusion injury, and cerebrovascular diseases like stroke. A critical evaluation of therapeutic strategies designed to restore NOE is presented, encompassing classic NO donors and phosphodiesterase-5 inhibitors, alongside next-generation soluble guanylate cyclase modulators and precision nanomedicine approaches. By identifying key knowledge gaps and methodological hurdles, this review charts a course for future research focused on biomarker-guided interventions and personalized medicine. Ultimately, we frame the restoration of NOE as a paramount therapeutic goal, crucial to translating decades of molecular research into effective clinical practice.

Diabetic retinopathy (DR) is a leading cause of vision loss worldwide and represents a complex neurovascular complication of diabetes mellitus driven by chronic hyperglycemia. Increasing evidence identifies oxidative stress—defined as an imbalance between reactive oxygen species (ROS) production and antioxidant defenses—as a central pathogenic mechanism linking metabolic dysregulation to retinal injury. The retina is particularly vulnerable to oxidative damage due to its high metabolic demand, elevated oxygen consumption, and abundance of polyunsaturated fatty acids. Hyperglycemia activates multiple interconnected biochemical pathways, including the polyol and hexosamine pathways, protein kinase C signaling, advanced glycation end-product formation, and lipid peroxidation, all of which converge on excessive ROS production and mitochondrial dysfunction. Growing attention has focused on oxidative stress biomarkers as tools to characterize DR severity and progression. Elevated systemic markers of lipid, protein, and DNA oxidation, together with impaired antioxidant capacity, correlate with disease stage, while oxidative biomarkers detected in aqueous and vitreous humor reflect localized retinal injury. Importantly, oxidative stress biomarkers are also associated with functional outcomes, including best-corrected visual acuity and diabetic macular edema. Integration of systemic and ocular oxidative biomarkers with clinical staging may improve risk stratification and support personalized therapeutic strategies in DR.

Oxidative stress, the alteration of mitochondrial function, and the neurovascular unit (NVU), play a role in Amyotrophic Lateral Sclerosis (ALS) pathogenesis. We aimed to demonstrate the changes in the plasma redox system and nitric oxide (NO) in 32 new ALS-diagnosed patients in treatment with Acetyl-L-Carnitine (ALCAR) compared to healthy controls. We also evaluated the effects of plasma on human umbilical cord-derived endothelial vascular cells (HUVEC) and astrocytes. The analyses were performed at the baseline (T0), after three months (T1), and after six months (T2). In ALS patients at T0/T1, the plasma markers of lipid peroxidation, thiobarbituric acid reactive substances (TBARS) and 4-hydroxy nonenal (4-HNE) were higher, whereas the antioxidants, glutathione (GSH) and the glutathione peroxidase (GPx) activity were lower than in healthy controls. At T2, plasma TBARS and 4-HNE decreased, whereas plasma GSH and the GPx activity increased in ALS patients. As regards NO, the plasma levels were firmly lower at T0–T2 than those of healthy controls. Cell viability, and mitochondrial membrane potential in HUVEC/astrocytes treated with the plasma of ALS patients at T0–T2 were reduced, while the oxidant release increased. Those results, which confirmed the fundamental role of oxidative stress, mitochondrial function, and of the NVU in ALS pathogenesis, can have a double meaning, acting as disease markers at baseline and potential markers of drug effects in clinical practice and during clinical trials.

Oxidative stress, the alteration of mitochondrial function, and changes in the neurovascular unit (NVU) could play a role in Amyotrophic Lateral Sclerosis (ALS) pathogenesis. Our aim was to analyze the plasma redox system and nitric oxide (NO) in 25 ALS new-diagnosed patients and five healthy controls and the effects of plasma on the peroxidation/mitochondrial function in human umbilical cord-derived endothelial vascular cells (HUVEC) and astrocytes. In plasma, thiobarbituric acid reactive substances (TBARS), glutathione (GSH), and nitric oxide (NO) were analyzed by using specific assays. In HUVEC/astrocytes, the effects of plasma on the release of mitochondrial reactive oxygen species (mitoROS) and NO, viability, and mitochondrial membrane potential were investigated. In the plasma of ALS patients, an increase in TBARS and a reduction in GSH and NO were found. In HUVEC/astrocytes treated with a plasma of ALS patients, mitoROS increased, whereas cell viability and mitochondrial membrane potential decreased. Our results show that oxidative stress and NVU play a central role in ALS and suggest that unknown plasma factors could be involved in the disease pathogenesis. Quantifiable changes in ALS plasma related to redox state alterations can possibly be used for early diagnosis.

The increasing prevalence of liver diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD), presents considerable medical challenges, particularly given the absence of approved pharmacological treatments, which underscores the necessity to comprehend its underlying mechanisms. Extracellular vesicles (EVs), which are tiny particles released by cells, play a crucial role in facilitating communication and can transport harmful molecules that promote inflammation and tissue damage. These EVs are involved in the progression of various types of liver disorders since they aggravate inflammation and oxidative stress. Because of their critical role, it is believed that EVs are widely involved in the initiation and progression of MASLD, as well as in viral hepatitis, alcoholic liver disease, drug-induced liver injury, and hepatocellular carcinoma. This review emphasizes recent findings regarding the functions of EVs in the above liver pathologies and underscores their potential as new therapeutic targets, paving the way for innovative approaches to address those detrimental liver conditions.