Comparative Analysis of the Effect of Uridine on Oxidative and Energy Metabolism in the Blood during Administration of Rotenone and 6-Hydroxydopamine in Rats.

In this study, oxidative energy metabolism was determined in 5 captive bottlenose dolphins (Tursiops truncatus), and subsequently compared to 6 Thoroughbred riding horses, and 12 lactating Holstein cows in order to assess symmorphosis of each animal species.Plasma metabolites profile, plasma MDH (M) and LDH (L) activities, M/L ratio, and plasma LDH isoenzyme distribution patterns were all examined.Overall, dolphins appear to have the greatest level of oxidative energy metabolism amongst horses and cows, due to having the greatest levels of plasma MDH activity.In addition, dolphin energy production/usage efficiency, via oxidative metabolism, was considered to be second (M/L ratio = 0.49) behind that of horses (M/L ratio = 0.79), possibly due to an increased reliance of non-oxidative energy metabolism over horses.In spite of demonstrating the lowest oxidative energy production/usage efficiency (M/L ratio = 0.15), cows also demonstrated the highest plasma LDH activity amongst all animal species.Although all animal groups displayed differing plasma LDH isoenzyme distribution patterns, dolphins and horses demonstrated a similarity with LDH-3 isoenzyme predominating in plasma; whereas LDH-1 isoenzyme predominates in cow plasma, thus inferring differences in oxidative/non-oxidative metabolism for energy generation/usage.Therefore, plasma MDH and LDH activity levels, M/L ratio, and plasma LDH isoenzyme pattern can all be useful indicators for better understanding oxidative energy metabolism and monitoring of captive animals' health.As it is not easy to obtain tissue samples from animals, the development of blood indicators for evaluating whole body metabolic state is necessary.

Cardiomyopathies are among the most severe myocardial pathologies, which are characterized by resistance to therapy and high mortality due to increasing heart failure and arrhythmia. Cardiomyocyte pathological changes upon cardiomyopathies are associated with mitochondrial dysfunction, leading to excessive formation of reactive oxygen species and the development of oxidative stress. In this regard, the study of the therapeutic potential of antioxidants in cardiomyopathies, as well as the mechanisms of their action on the functioning of mitochondria, is relevant and of high practical importance. The aim of this study was to determine the effect of oral 14-day administration of dihydroquercetin in a water-soluble form (DHQWF) on the activity of the key marker of mitochondrial respiration [succinate dehydrogenase (SDH)] and the cytoplasmic marker of glycolysis [lactate dehydrogenase (LDH)] in blood lymphocytes, as well as on the serum level of lipid peroxidation (LPO) in control rats and rats with experimental cardiomyopathy. Material and methods. Adult male Wistar rats (body weight 220-240 g) were used for the study. Isoprenaline hydrochloride was used to induce cardiomyopathy (IIC) in animals (twice subcutaneous injection at a dose of 150 mg/kg body weight, with a break of 24 hours). DHQ-WF was added to the drinking water for 14 days at the dose of 15 or 30 mg/kg body weight. SDH and LDH activity in lymphocytes was measured using a highly sensitive cytobiochemical method on a blood smear according to the reduction of nitrotetrazolium blue chloride to diformazan of dark blue color. The content of malone dialdehyde (MDA) in the blood serum, heart and liver mitochondria was determined spectrophotometrically using thiobarbituric acid. Mitochondria were isolated from rat tissues by the conventional method of differential centrifugation. Mitochondrial respiration was recorded using a polarographic method. Results. Experimental cardiomyopathy in rats was accompanied by a twofold increase in blood serum MDA level, as well as by a significant increase in SDH and LDH activity in blood lymphocytes. The oral administration of DHQ-WF in cardiomyopathy at a dose of 15 mg/kg body weight led to a significant decrease in serum MDA level, but did not reduce the activity of SDH and LDH in blood lymphocytes, compared with animals with cardiomyopathy that did not receive DHQ-WF. In the control group of animals, the use of DHQ-WF at a dose of 15 mg/kg body weight significantly increased blood lymphocyte LDH activity, but did not have a statistically significant effect on SDH activity and the parameters of mitochondrial respiration and oxidative phosphorylation, the level of MDA in heart and liver mitochondria. Increasing the dose of DHQ-WF administered to 30 mg/kg had less effect on changes in these parameters in control animals. Conclusion. The data obtained indicate that in experimental cardiomyopathy in rats, the course application of DHQ-WF at a dose of 15 mg/kg of body weight acts as an effective antioxidant that prevents the development of lipid peroxidation in blood serum, and can modulate energy metabolism towards the enhancement of glycolysis in blood lymphocytes in control animals.

Rats with experimental Parkinson's syndrome induced by seven-day intraperitoneal administration of rotenone at a dose of 2.75 mg/kg have an increased activity of prolylendopeptidase (EC 3.4.21.26, PREP) in blood serum and a decreased activity of adenosine deaminase (EC 3.5.4.4, ADA) in serum and in the prefrontal cortex. PREP and ADA activity in other brain structures (in the striatum, hypothalamus and hippocampus) did not change; dipeptidyl peptidase IV activity (EC 3.4.14.5, DPP-4, CD26) also remained constant in serum and in all the brain structures investigated. Afobazole and levodopa, which exhibit antiparkinsonian activity in this model of Parkinson's syndrome, decrease elevated PREP activity in serum and increase reduced ADA activity in the prefrontal cortex of rats with the experimental pathology. Meanwhile, treatment with the study drugs was associated with a decrease of ADA activity in the other brain structures.

Uridine is a precursor of the metabolic activator of the mitochondrial potassium channel leading to tissue protection from hypoxic damage under oxidative stress. In this research, we studied its effects in rats with lactacystin (LC)-induced Parkinson's disease (PD). The biological effect was recorded by the cytobiochemical method for detecting the physiological regulation of enzyme activity in lymphocytes on a blood smear. The activity of succinate dehydrogenase (SDH), an enzyme of mitochondrial energy supply, and lactate dehydrogenase (LDH), a glycolytic enzyme, was measured. Uridine at a dose of 30 mg/kg for 28 days in the modelled preclinical stage (MPS) of PD causes a decrease in hyperactive SDH to the control level. At the same time, in the modelled clinical stage (MCS), uridine exhibited no such effects. Regarding the LDH glycolysis enzyme, the modelled preclinical stage of PD was characterized by a twofold increase in the activity of this enzyme, with uridine having only a slight effect. In the clinical stage of PD, lactocystin also increased the activity of SDH, with virtually no effect on the activity of LDH, while uridine increased the activity of both enzymes. The revealed protective effect of uridine in MPS in rats is explained by the restoration of early pathological disorders of mitochondria in lymphocytes, with an increase in glycolysis over respiration. This effect is not detected in the MCS, where, apparently, irreversible mitochondrial pathology develops.

To determine the mitochondrial dysfunction in multiple sclerosis (MS). Fourteen adult patients with MS and 23 healthy people were examined. Cytochemical analysis of lymphocytes in peripheral blood was carried out. The activity of the mitochondrial enzymes involved in metabolism of carbohydrates (lactate dehydrogenase, LDH), amino acids (glutamate dehydrogenase, GDH), fatty acids (alpha-glycerophosphate, α-GPDH) and II complex of the mitochondrial respiratory chain (succinate dehydrogenase, LDH), and the level of lactate in the blood were measured. The activity of α-GPDH was reduced in 62.5% patients and increased in 37.5%. GDH activity in all patients was lowered. LDH activity was reduced in 71.4% patients and compensatory increased in 28.6%. In 66.7% patients, LDH activity was reduced and in 33.3% compensatory increased. Increased blood lactate was observed in 33.3% patients before meal and 44.4% after carbohydrate loading. After carbohydrate loading, in 33.3% patients lactate levels in the blood increased and in 11.1% increased above normal values. Therefore, the enzyme activity have decreased in most patients that suggests the decompensation of mitochondrial function. The results indicate the advisability of administering the energotrophic drugs carnicetin and coenzyme Q10 (idebenone) in patients with MS.

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases. To date, among medications used to treat PD, only levodopa exhibits a limited disease-modifying effect on early-onset PD, but it cannot delay the progression of the disease. In 2018, for the first time, the World Health Organization included traditional Chinese medicine (TCM) in its influential global medical compendium. The use of TCM in the treatment of PD has a long history. At present, TCM can help treat and prevent PD. Iron metabolism is closely associated with PD. Ferroptosis, which is characterized by the accumulation of lipid peroxides, is a recently discovered form of iron-dependent cell death. The research literature indicates that ferroptosis in dopaminergic neurons is an important pathogenetic mechanism of PD. TCM may thus play unique roles in the treatment of PD and provide new ideas for the treatment of PD by regulating pathways associated with ferroptosis.

MOLECULAR PERTURBATIONS IN SYNUCLEINOPATHY DISORDERS: INSIGHTS FROM PRE-CLINICAL TO HUMAN NEUROPATHOLOGY

Effects of myogenin on muscle fiber types and key metabolic enzymes in gene transfer mice and C2C12 myoblasts

NMN recruits GSH to enhance GPX4-mediated ferroptosis defense in UV irradiation induced skin injury

The main pathological hallmark of diabetes is the loss of functional β-cells. Among several types of β-cell death in diabetes, the involvement of ferroptosis remains elusive. Therefore, we investigated the potential of diabetes-mimicking factors: high glucose (HG), proinflammatory cytokines, hydrogen peroxide (H2O2), or diabetogenic agent streptozotocin (STZ) to induce ferroptosis of β-cells in vitro. Furthermore, we tested the contribution of ferroptosis to injury of pancreatic islets in an STZ-induced in vivo diabetic model. All in vitro treatments increased loss of Rin-5F cells along with the accumulation of reactive oxygen species, lipid peroxides and iron, inactivation of NF-E2-related factor 2 (Nrf2), and decrease in glutathione peroxidase 4 expression and mitochondrial membrane potential (MMP). Ferrostatin 1 (Fer-1), ferroptosis inhibitor, diminished the above-stated effects and rescued cells from death in case of HG, STZ, and H2O2 treatments, while failed to increase MMP and to attenuate cell death after the cytokines' treatment. Moreover, Fer-1 protected pancreatic islets from STZ-induced injury in diabetic in vivo model, since it decreased infiltration of macrophages and accumulation of lipid peroxides and increased the population of insulin-positive cells. Such results revealed differences between diabetogenic stimuli in determining the destiny of β-cells, emerging HG, H2O2, and STZ, but not cytokines, as contributing factors to ferroptosis and shed new light on an antidiabetic strategy based on Nrf2 activation. Thus, targeting ferroptosis in diabetes might be a promising new approach for preservation of the β-cell population. Our results obtained from in vivo study strongly justify this approach.

Asthma exacerbations and airway redox imbalance under type 2 inflammatory conditions

During the pathological process of spinal cord injury (SCI), ferroptosis is closely related to mitochondrial homeostasis. Following the occurrence of SCI, the interruption of local blood supply leads to mitochondrial damage within cells and a reduction in Adenosine triphosphate (ATP) production. This results in the loss of transmembrane ion gradients, causing an influx of Ca2+ into the cells, which in turn generates a significant amount of Reactive oxygen species (ROS) and reactive nitrogen species. This leads to severe mitochondrial dysfunction and an imbalance in mitochondrial homeostasis. Ferroptosis is a form of programmed cell death that differs from other types of apoptosis, as it is dependent on the accumulation of iron and lipid peroxides, along with their byproducts. The double bond structures in intracellular polyunsaturated fatty acids (PUFA) are particularly susceptible to attack by ROS, leading to the formation of lipid alkyl free radicals. This accumulation of lipid peroxides within the cells triggers ferroptosis. After SCI, the triggering of ferroptosis is closely associated with the “death triangle”—a core network that catalyzes cell death through the interaction of three factors: local iron overload, collapse of antioxidant defenses, and dysregulation of PUFA metabolism (where PUFA are susceptible to attack by reactive ROS leading to lipid peroxidation). These three elements interact to form a central network driving cell death. In the pathological cascade of SCI, mitochondria serve as both a major source of ROS and a primary target of their attack, playing a crucial role in the initiation and execution of cellular ferroptosis. Mitochondrial homeostasis imbalance is not only a key inducer of the “death triangle” (such as the intensification of lipid peroxidation by mitochondrial ROS), but is also reverse-regulated by the “death triangle” (such as the destruction of mitochondrial structure by lipid peroxidation products). Through the cascade reaction of this triangular network, mitochondrial homeostasis imbalance and the “death triangle” jointly drive the progression of secondary damage. This study aims to synthesize the mechanisms by which various therapeutic approaches mitigate SCI through targeted regulation of mitochondrial homeostasis and inhibition of ferroptosis. Unlike previous research, we integrate the bidirectional regulatory relationship between “mitochondrial homeostasis disruption” and “ferroptosis” in SCI, and emphasize their importance as a synergistic therapeutic target. We not only elaborate in detail how mitochondrial homeostasis—including biogenesis, dynamics, and mitophagy—modulates the initiation and execution of ferroptosis, but also summarize recent strategies that simultaneously target both processes to achieve neuroprotection and functional recovery. Furthermore, this review highlights the translational potential of various treatments in blocking the pathological cascade driven by oxidative stress and lipid peroxidation. These insights provide a novel theoretical framework and propose combinatory therapeutic approaches, thereby laying the groundwork for designing precise and effective comprehensive treatment strategies for SCI in clinical settings.

Ferroptosis is a type of regulated cell death caused by oxidative imbalance of the intracellular microenvironment. This causes the accumulation of toxic lipid peroxides, depicted by iron overload and lipid peroxidation, which results in disease development. The affected cell population displays unique morphological and biochemical features, which are distinct from other modes of cell death, like apoptosis, pyroptosis, and necroptosis. The individual pathways of each of these modes are interrelated and tend to counterbalance each other in the mechanism of cell death. The process of ferroptosis is associated with disturbances in iron metabolism, in conjunction with glutathione peroxidase and lipid peroxidation, culminating in a reduction of antioxidant capacity and accumulation of lipid peroxides in the dying cell. It has been observed that even excess cellular levels of iron can cause cell death, where ferroptosis is initiated by diminishing the levels of glutathione and glutathione peroxidase 4, and thus leading to excess build-up of lipid reactive oxygen species (ROS). In the case of a neoplastic cell, ferroptosis along with its regulators tends to orchestrate cell death and also affects cancer progression by modulation of proliferation activity, apoptosis suppression, metastasis, and drug resistance. Comprehending the complex network of molecular processes implicated in ferroptosis regulation is vital for developing targeted therapies for diseases where ferroptosis plays a significant role.

Ferroptosis, an iron-dependent cell death mechanism driven by an accumulation of lipid peroxides on cellular membranes, has emerged as a promising strategy to treat various diseases, including cancer. Ferroptosis inducers not only exhibit cytotoxic effects on multiple cancer cells, including drug-resistant cancer variants, but also hold potential as adjuncts to enhance the efficacy of other anti-cancer therapies, such as immunotherapy. In addition to synthetic inducers, natural compounds, such as artemisinin, can be considered ferroptosis inducers. Artemisinin, extracted from Artemisia annua L., is a poorly water-soluble antimalarial drug. For clinical applications, researchers have synthesized various water-soluble artemisinin derivatives such as dihydroartemisinin, artesunate, and artemether. Artemisinin and artemisinin derivatives (ARTEs) upregulate intracellular free iron levels and promote the accumulation of intracellular lipid peroxides to induce cancer cell ferroptosis, alleviating cancer development and resulting in strong anti-cancer effects in vitro and in vivo. In this review, we introduce the mechanisms of ferroptosis, summarize the research on ARTEs-induced ferroptosis in cancer cells, and discuss the clinical research progress and current challenges of ARTEs in anti-cancer treatment. This review deepens the current understanding of the relationship between ARTEs and ferroptosis and provides a theoretical basis for the clinical anti-cancer application of ARTEs in the future.

Anti-aging is a challenging and necessary research topic. Momordica charantia L. is a common edible medicinal plant that has various pharmacological activities and is often employed in daily health care. However, its anti-aging effect on mice and the underlying mechanism thereof remain unclear. Our current study mainly focused on the effect of Momordica charantia L. on d-galactose-induced subacute aging in mice and explored the underlying mechanism. UHPLC-Q-Exactive Orbitrap MS was applied to qualitatively analyze the chemical components of Momordica charantia L. ethanol extract (MCE). A subacute aging mice model induced by d-galactose (d-gal) was established to investigate the anti-aging effect and potential mechanism of MCE. The learning and memory ability of aging mice was evaluated using behavioral tests. The biochemical parameters, including antioxidant enzyme activity and the accumulation of lipid peroxides in serum, were measured to explore the effect of MCE on the redox imbalance caused by aging. Pathological changes in the hippocampus were observed using hematoxylin and eosin (H&E) staining, and the levels of aging-related proteins in the PI3K/AKT signaling pathway were assessed using Western blotting. The experimental results demonstrated that a total of 14 triterpenoids were simultaneously identified in MCE. The behavioral assessments results showed that MCE can improve the learning and memory ability of subacute mice. The biochemical parameters determination results showed that MCE can improve the activity of antioxidant enzymes and decrease the accumulation of lipid peroxides in aging mice significantly. Furthermore, aging and injury in the hippocampus were ameliorated. Mechanistically, the results showed a significant upregulation in the protein expression of P-PI3K/PI3K and P-AKT/AKT (p < 0.01), as well as a significant reduction in cleaved caspase-3/caspase-3, Bax and P-mTOR/mTOR (p < 0.01). Our results confirm that MCE could restore the antioxidant status and improve cognitive impairment in aging mice, inhibit d-gal-induced apoptosis by regulating the PI3K/AKT signaling pathway, and rescue the impaired autophagy caused by mTOR overexpression, thereby exerting an anti-aging effect.