Oxidative Modification Of Proteins Research Articles

EXECUTER2 modulates the EXECUTER1 signalosome through its singlet oxygen-dependent oxidation

Oxidative post-translational modifications of specific chloroplast proteins contribute to the initiation of retrograde signaling. The Arabidopsis thaliana EXECUTER1 (EX1) protein, a chloroplast-localized singlet oxygen (1O2) sensor, undergoes tryptophan (Trp) 643 oxidation by 1O2, a chloroplast-derived and light-dependent reactive oxygen species. The indole side chain of Trp is vulnerable to 1O2, leading to the generation of oxidized Trp variants and priming EX1 for degradation by a membrane-bound FtsH protease. The perception of 1O2 via Trp643 oxidation and subsequent EX1 proteolysis facilitate chloroplast-to-nucleus retrograde signaling. In this study, we discovered that the EX1-like protein EX2 also undergoes 1O2-dependent Trp530 oxidation and FtsH-dependent turnover, which attenuates 1O2 signaling by decelerating EX1-Trp643 oxidation and subsequent EX1 degradation. Consistent with this finding, the loss of EX2 function reinforces EX1-dependent retrograde signaling by accelerating EX1-Trp643 oxidation and subsequent EX1 proteolysis, whereas overexpression of EX2 produces molecular phenotypes opposite to those observed in the loss–of- function mutants of EX2. Intriguingly, phylogenetic analysis suggests that EX2 may have emerged evolutionarily to attenuate the sensitivity of EX1 toward 1O2. Collectively, these results suggest that EX2 functions as a negative regulator of the EX1 signalosome through its own 1O2-dependent oxidation, providing a new mechanistic insight into the regulation of EX1-mediated 1O2 signaling.

In vivo and In vitro Anti Oxidant Activity of Ethanolic Extraction of Justicia gendarussa Burm Leaves

Oxidation is very essential to many living organisms for the production of energy to fuel biological processes. The free radicals and other reactive oxygen species (ROS), which are continuously, produced in vivo, responsible for oxidation. The aim of the present study was to investigate in vitro and in vivo antioxidant potential of ethanolic extraction of justicia gendarussa burm leaves [EEJG]. The study was done by using various in vitro and In vivo methods such as Hydroxyl Radical scavenging activity, Determination of Reducing Power, Metal chelating activity, Carbon tetrachloride (CCl4) induced lipid peroxidation and Inhibitory Test on Protein Oxidative Modification and in vivo Lipid peroxidation, reduced glutathione and Catalase was studied. The ethyl acetate extract showed the highest total phenolic content and total flavonoid content among other extracts of justicia gendarussa burm leaves. The percentage inhibition and IC50 value of all the extracts were followed dose-dependency and found significant (P < 0.01) as compared to standard (ascorbic acid). The oxidative stress markers as Lipid peroxidation (LPO) (CAT) and reduced glutathione (GSH) were increased significantly (P < 0.01) at 250 and 500 mg/kg of EEJG treated animals and decreased significantly the thiobarbituric acid reactive substances [TBARS] level at 500 mg/kg of EEJG as compared to control group. These results revealed that the ethanol extract of Justicia gendarussa burm leaves exhibits both In vitro antioxidant activity against DPPH and In vivo antioxidant activity by modulating brain enzymes in the rat. This could be further correlated with its potential to neuroprotective activity due to the presence of flavonoids and phenolic contents in the extract.

THE IMPACT OF METFORMIN AND ROSUVASTATIN ON THE MARKERS OF OXIDATIVE STRESS, GLYCEMIC CONTROL, AND LIPID PROFILE IN RATS WITH STREPTOZOTOCIN-NICOTINAMIDE-INDUCED DIABETES AFTER ACUTE INTRACEREBRAL HEMORRHAGE

Hyperproduction of highly active carbonyl compounds and reactive oxygen species initiates the development of oxidative stress in various pathological conditions and protein carbonylation is considered to be one of the key factors in the progression of diabetes mellitus and associated complications. This comparative research aimed to study the effect of metformin and rosuvastatin on the levels of biochemical markers of oxidative stress, glycemic control, and lipid profile in rats with type 2 diabetes mellitus (T2DM) complicated by a brain hemorrhage.T2DM was simulated with a single intraperitoneal injection of nicotinamide and streptozotocin (NA/STZ) to male Wistar rats (n=38). Intracerebral hemorrhage (ICH) was induced by microinjection of 1 μL of bacterial collagenase 0.2 IU/μL into the striatum. Animals were randomized into 5 groups: negative control, intact rats; positive control 1, NA/STZ; positive control 2, NA/STZ+ICH; metformin, 250 mg/kg +NA/STZ+ICH; rosuvastatin, 15 mg/kg+NA/STZ+ICH. Drug effects were assessed by the area under the glycemic curve (AUC), the content of glucose, glycated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), homocysteine (Hcy), advanced glycation end products (AGEs), and the markers of oxidative modification of proteins – aldehyde- and ketonephenylhydrazones (APH/KPH) in blood serum.It was found that brain hemorrhage in rats with T2DM can intensify the manifestations of oxidative modification of molecules and worsen glycemic control and lipid profile. Under these conditions, rosuvastatin improved lipid metabolism and reduced the levels of AGEs by 35.1% but did not affect glycemia and content of APH/KPH. Metformin reduced oxidative stress (AGEs by 35.4%, KPH by 21.2%) as well as improved both glycemic status and lipid profile (TG level by 20.2%, TG/HDL ratio by 31.9%). Both drugs did not produce any effect on Hcy level.Thus, metformin in conditions of T2DM complicated by acute ICH has advantages over rosuvastatin in relation to the markers of oxidative modification and glycemic control.

Effect of Linseed Oil Supplementation on Lipid Peroxidation and Antioxidant Capacity in Pregnant Overfed Obese Rats and Their Offspring

Effect of Linseed Oil Supplementation on Lipid Peroxidation and Antioxidant Capacity in Pregnant Overfed Obese Rats and Their Offspring

Effects of Extracts Derived from Roots and Stems of Chelidonium majus L. on Oxidative Stress Biomarkers in the Model of Equine Plasma

Greater celandine (Chelidonium majus L., Papaveraceae) is a perennial herbaceous plant, with an upright and spreading stem, large leaves, and yellow flowers collected on the tops of the stems in rare umbel inflorescence. The main aim of the study was an assessment of the oxidative stress biomarkers [2-thiobarbituric acid reactive substances (TBARS), carbonyl derivatives content of protein oxidative modification (OMP), total antioxidant capacity (TAC)] and also activity of antioxidant enzymes (catalase, ceruloplasmin) in the equine plasma after treatment by extracts derived from roots and stems of C. majus collected from rural and urban agglomerations. Plant materials were collected from natural habitats on the territory of the Kartuzy district in the Pomeranian province (northern part of Poland). Our results demonstrated that statistically significant reductions in lipid peroxidation byproducts were noted after incubation with extracts derived from roots of C. majus collected from both urban (by 35 %, p <0.05) and rural (by 34 %, p <0.05) agglomerations compared to the control samples. Stem extracts derived from C. majus also reduced TBARS levels, but only extracts derived from C. majus were collected from the rural areas; a statistically significant decrease (by 21 %, p <0.05) was observed compared to the control samples. The lowest values in the content of the aldehydic derivatives of OMP were observed after incubation with extracts derived from roots of C. majus collected from both rural and urban areas. On the other hand, levels of ketonic derivatives of OMP were significantly increased after incubation with extracts derived from stems of C. majus collected from both rural and urban areas compared to the control samples, in contrast to extracts derived from roots of C. majus collected from urban areas, where there was a statistically significant reduction in ketonic derivatives of OMP (by 15 %, p<0.05) compared to the control samples. A significant increase in the TAC levels was observed after incubation with root and stem extracts of C. majus collected from both urban and rural areas, but the highest values were observed after incubation with extracts derived from roots of C. majus collected from rural areas (by 66.7 %, p <0.05) compared to the control samples. Stem extracts of C. majus collected from urban agglomerations were found to be most effective in increasing catalase activity (by 115 %, p <0.05). Both root and stem extracts of C. majus collected from rural areas caused a statistically significant reduction in ceruloplasmin levels. These in vitro studies indicate that extracts from this plant are a significant source of natural antioxidants that could prevent the progression of various disorders caused by oxidative stress. However, the proportions of secondary metabolites responsible for the antioxidant activity of C. majus extracts are currently unclear. Therefore, further studies are needed to isolate and identify the antioxidant compounds present in the plant extracts. Screening of C. majus plant for other biological activities including antioxidant activities is essential and may be effective for searching the preventive agents in the pathogenesis of some metabolic diseases.

Effect of 2-Cys Peroxiredoxins Inhibition on Redox Modifications of Bull Sperm Proteins.

Sperm peroxiredoxins (PRDXs) are moonlighting proteins which, in addition to their antioxidant activity, also act as redox signal transducers through PRDX-induced oxidative post-translational modifications of proteins (oxPTMs). Despite extensive knowledge on the antioxidant activity of PRDXs, the mechanisms related to PRDX-mediated oxPTMs are poorly understood. The present study aimed to investigate the effect of bull sperm 2-Cys PRDX inhibition by Conoidin A on changes in oxPTM levels under control and oxidative stress conditions. The results showed that a group of sperm mitochondrial (LDHAL6B, CS, ACO2, SDHA, ACAPM) and actin cytoskeleton proteins (CAPZB, ALDOA, CCIN) is oxidized due to the action of 2-Cys PRDXs under control conditions. In turn, under oxidative stress conditions, 2-Cys PRDX activity seems to be focused on antioxidant function protecting glycolytic, TCA pathway, and respiratory chain enzymes; chaperones; and sperm axonemal tubulins from oxidative damage. Interestingly, the inhibition of PRDX resulted in oxidation of a group of rate-limiting glycolytic proteins, which is known to trigger the switching of glucose metabolism from glycolysis to pentose phosphate pathway (PPP). The obtained results are expected to broaden the knowledge of the potential role of bull sperm 2-Cys in both redox signal transmission and antioxidant activity.

Metal stresses modify soluble proteomes and toxin profiles in two Mediterranean strains of the distributed dinoflagellate Alexandrium pacificum

HABs involving Alexandrium pacificum have been reported in metal-contaminated ecosystems, suggesting that this distributed species adapts to and/or can tolerate the effects of metals. Modifications in soluble proteomes and PST contents were characterized in two Mediterranean A. pacificum strains exposed to mono- or polymetallic stresses (zinc, lead, copper, cadmium). These strains were isolated from two anthropized locations: Santa Giusta Lagoon (Italy, SG C10-3) and the Tarragona seaport (Spain, TAR C5-4F). In both strains, metals primarily downregulated key photosynthesis proteins. Metals also upregulated other proteins involved in photosynthesis (PCP in both strains), the oxidative stress response (HSP 60, proteasome and SOD in SG C10-3; HSP 70 in TAR C5-4F), energy metabolism (AdK in TAR C5-4F), neoglucogenesis/glycolysis (GAPDH and PEP synthase in SG C10-3) and protein modification (PP in TAR C5-4F). These proteins, possibly involved in adaptive proteomic responses, may explain the development of these A. pacificum strains in metal-contaminated ecosystems. The two strains showed different proteomic responses to metals, with SG C10-3 upregulating more proteins, particularly PCP. Among the PSTs, regardless of the metal and the strain studied, C2 and GTX4 predominated, followed by GTX5. Under the polymetallic cocktail, (i) total PSTs, C2 and GTX4 reached the highest levels in SG C10-3 only, and (ii) total PSTs, C2, GTX5 and neoSTX were higher in SG C10-3 than in TAR C5-4F, whereas in SG C10-3 under copper stress, total PSTs, GTX5, GTX1 and C1 were higher than in the controls, revealing variability in PST biosynthesis between the two strains. Total PSTs, C2, GTX4 and GTX1 showed significant positive correlations with PCP, indicating that PST production may be positively related to photosynthesis. Our results showed that the A. pacificum strains adapt their proteomic and physiological responses to metals, which may contribute to their ecological success in highly anthropized areas.

Changes in biomarkers of endothelial function in the blood after intracerebral hemorrhage in rats with type 2 diabetes mellitus

Clinical evidence suggests that type 2 diabetes mellitus can increase the risk of intracerebral hemorrhage and provocation of neurodegeneration. This study was aimed at evaluating biomarkers of glycemic control, lipid profile, oxidative modification of proteins, as well as the functional state of endothelium in Wistar rats with type 2 diabetes mellitus complicated by intracerebral hemorrhage. Experimental type 2 diabetes mellitus was induced by intraperitoneal injection of streptozotocin (65 mg/kg) and nicotinamide (230 mg/kg). The intracerebral hemorrhage was induced by microinjection of sterile saline containing 0.2 IU bacterial collagenase into the striatum. Assessed biomarkers included the area under glycemic curve, glycated hemoglobin, total cholesterol, triglyceride, high-density lipoprotein, advanced glycation end products, markers of oxidative modification of proteins – aldehyde- and ketonephenylhydrazones, and markers of endothelial dysfunction – homocysteine, endothelin-1, von Willebrand factor and asymmetric dimethylarginine in blood serum. Both rats with type 2 diabetes mellitus and rats with intracerebral hemorrhage and diabetes had a significant elevated glycemic control as compared to intact animals. But combined pathology was additionally characterized by an impairment of lipid profile (increased triglyceride level and decreased as total cholesterol and high-density lipoprotein) resulting in a rise in the atherogenic index of plasma. A significant increase in the content of the markers of oxidative modification of proteins was observed in both experimental groups. But the rats with intracerebral hemorrhage and diabetes only had higher levels of advanced glycation end products in comparison with intact animals. The highest levels of endothelin-1, as a biomarker of endothelial dysfunction, were observed in animals with intracerebral hemorrhage and diabetes. Homocysteine and von Willebrand factor were elevated in rats with type 2 diabetes mellitus, while acute intracerebral hemorrhage did not potentiate the further growth in its levels. Such effect was not accompanied by a marked increase of asymmetric dimethylarginine level in blood serum, although there was a clear trend. In conclusion, the development of intracerebral hemorrhage in rats with type 2 diabetes mellitus can intensify the manifestations of oxidative stress, worsen lipid profile, and aggravate endothelial dysfunction. In this case, the pathological process may have the character of a “vicious circle”.

Effectiveness of oxidative stress correction at non-alcoholic steatohepatitis and diabetic kidney disease in patients with type 2 diabetes mellitus

Objective — to study the state of oxidative‑antioxidant homeostasis, intensity of hepatocytes’ apoptosis based on the blood levels of cytokeratin‑18 in patients with non‑alcoholic steatohepatitis (NASH) and type 2 diabetes mellitus (DM 2) depending on the stage of diabetic kidney disease, and to investigate effects of the medications’ complex on the above factors.
 Materials and methods. The investigation was performed in the dynamics of treatment of 75 NASH patients with DM 2 and DKD of stage I — III. Depending on the treatment type, patients were divided into two groups. The control group (37 patients) was administered a hypocaloric diet with account of dietary restrictions #9, received essential phospholipids (Essentiale forte H) 300 mg 2 caps. 3 times a day) during 30 days for the NASH treatment, and antidiabetic and lipid‑lowering therapy with metformin hydrochloride (Metformin ‑Teva) 1000 mg per day, rosuvastatin (5 mg 1 time per day) for 1 month. The main group consisted of 38 patients and in addition to the similar 30 days of dietary recommendations, essential phospholipids, hypoglycemic and hypolipidemic therapy, received quercetin and povidone (Corvitin) 500 mg intravenously in 100 ml of isotonic sodium 10 mg for 10 days. The mean age of patients was (54.7 ± 3.56) years. Both groups were randomized by age, gender ratio and disease duration.
 Results. Before the treatment, the significant degree of oxidative stress was established, which was accompanied by accumulation in the blood of intermediate and final products of lipid peroxidation and oxidative modification of proteins. Blood plasma levels of malonic aldehyde exceeded the reference values in 2.1 times (p < 0.05). The state of the antioxidant defense system was significantly disbalanced. The blood levels of reduced glutathione were in 1.7 times lower than in healthy individuals (p < 0.05), glutathione peroxidase activity was inhibited in 1.3 times (p < 0.05), which explains the high intensity of oxidative stress in the examined patients.
 Conclusions. In patients with type 2 diabetes mellitus, accompanied by diabetic kidney disease with comorbid non‑alcoholic steatohepatitis, the significant increase in the oxidative stress intensity was observed, together with 1 to 3‑fold raise (p < 0.05) in the blood levels of intermediate and final products of lipid peroxidation and oxidative proteins’ modification.

Homocysteine in Schizophrenia: Independent Pathogenetic Factor with Prooxidant Activity or Integral Marker of Other Biochemical Disturbances?

A wide range of studies have demonstrated that hyperhomocysteinemia is associated with the risk of schizophrenia, but currently available assumptions about the direct involvement of homocysteine (Hcy) in the pathogenesis of schizophrenia are hypothetical. It is possible that in vivo Hcy is only a marker of folate metabolism disturbances (which are involved in methylation processes) and is not a pathogenetic factor per se. Only one study has been conducted in which associations of hyperhomocysteinemia with oxidative stress in schizophrenia (oxidative damage to protein and lipids) have been found, and it has been suggested that the oxidative stress may be induced by the elevated Hcy in schizophrenic patients. But the authors did not study the level of reduced glutathione (GSH), as well as possible causes of hyperhomocysteinemia—disturbances of folate metabolism. The aim of this work is to analyze the association of Hcy levels with the following: (1) redox markers in schizophrenia GSH, markers of oxidative damage of proteins and lipids, and the activity of antioxidant enzymes in blood serum; (2) with the level of folate and cobalamin (В12); and (3) with clinical features of schizophrenia measured using the Positive and Negative Syndrome Scale (PANSS). 50 patients with schizophrenia and 36 healthy volunteers, matched by sex and age, were examined. Hcy in patients is higher than in healthy subjects (p = 0.0041), and this may be due to the lower folate level in patients (p = 0.0072). In patients, negative correlation was found between the level of Hcy both with the level of folate (ρ = −0.38, p = 0.0063) and with the level of B12 (ρ = −0.36, p = 0.0082). At the same time, patients showed higher levels of oxidative modification of serum proteins (p = 0.00046) and lower catalase (CAT) activity (p = 0.014). However, Hcy is not associated with the studied markers of oxidative stress in patients. In the group of patients with an increased level of Hcy (>10 μmol/l, n = 42) compared with other patients (n = 8), some negative symptoms (PANSS) were statistically significantly more pronounced: difficulty in abstract thinking (N5, p = 0.019), lack of spontaneity and flow in conversation (N6, p = 0.022), stereotyped thinking (N7, p = 0.013), and motor retardation (G7, p = 0.050). Thus, in patients with schizophrenia, hyperhomocysteinemia caused by deficiency of folate and B12 is confirmed and can be considered a marker of disturbances of vitamin metabolism. The redox imbalance is probably not directly related to hyperhomocysteinemia and is hypothetically caused by other pathological processes or by an indirect effect of Hcy, for example, on the enzymatic antioxidant defence system (CAT activity), which requires further exploration. Further study of the role of Hcy in the pathogenesis of schizophrenia is relevant, since the proportion of patients with hyperhomocysteinemia is high and correlations of its level with negative symptoms of schizophrenia are noted.

PSXV-14 Level of spontaneous oxidative modification of sperm plasma proteins in stallions of different ages

Abstract The objective of the study was to assess the level of spontaneous oxidative modification of sperm plasma proteins (OMP) in young and mature stallions as indicators of the severity of oxidative stress. Sperm from 12 stallions aged 14–18 years (average age 15.8±1.9 years) (Group I) and 12 stallions aged 3–5 years (average age 4.3±0.6 years; Group II) was obtained during the breeding season (February-May). Each ejaculate was evaluated by volume, concentration, total number of spermatozoa, as well as by the progressive motility and survival of spermatozoa in diluted sperm during its hypothermic storage at +4°C. For a quantitative assessment of the OMP level, a spectrophotometric analysis of 2,4-dinitrophenylhydrazones formed during the interaction of carbonyl derivatives of proteins with 2,4-dinitrophenylhydrazine was carried out (SF-2000, Russia). The level of aldehyde- and ketone-dinitrophenylhydrazones of neutral (ADNPHn, KDNPHn) and basic (ADNPGb, KDNPGb), and the total level of OMP (S OMP) was measured. Significance of differences was assessed by the Mann-Whitney test, the results were statistically significant at P ≤ 0.05. The total level of spontaneous OMP of sperm plasma in aged stallions is statistically significantly higher than in young stallions (531.7 and 384.3 Uod/g protein, respectively, P < 0.05). This indicates a higher degree of oxidative stress in Group I, a more significant damage to the amino acid residues of sperm plasma proteins. In Group I a shift in the absorption spectrum towards neutral aldehyde derivatives (367.6 and 255.8 Uod/g protein, respectively, P < 0.05) was noted. We assume that the pro-oxidant systems in a stallion body increasingly prevail over the protective ones with the age. This leads to an increase in the level of OMP in the sperm and a decrease in the survival of spermatozoa during the hypothermic storage of diluted sperm. Authors acknowledge financial support from Russian Science Foundation, Grant No: 20-16-00101.

Lipid peroxidation and oxidative modification of proteins in tick-borne encephalitis and ixodic tick-borne borreliosis

BACKGROUND: In the South Ural region of Russia, the group of ITTB and TBE occupies the leading rank positions in the structure of infections that are ecologically associated with ixodic ticks. At the present stage, studies aimed at studying non-specific pathological biochemical processes that determine the degree of oxidative damage to cell membranes and organelle membranes, the reactivity of the body, its reserve-adaptive potential under the influence of a number of endogenous and exogenous factors are becoming particularly relevant. One of the most significant metabolic processes of this kind is the free radical oxidation of lipids and the oxidative modification of proteins.
 AIMS: To give a clinical and epidemiological characteristic and to study the role of oxidative stress in the pathogenesis of various clinical forms of tick-borne infections in an endemic region (on the example of the Chelyabinsk region).
 MATERIAL AND METHODS: The study was conducted at the clinical base of the Department of Infectious Diseases of the Southern State Medical University in the MAUZ GKB No. 8 in Chelyabinsk. The study randomly included 105 patients with tick-borne encephalitis, ixodic tick-borne borreliosis and mixed infection who were hospitalized in the hospital in the period from May to October 20182019. The diagnosis was verified by standard immunological methods (ELISA). Modern molecular genetic methods (PCR-RV) were used in the etiological diagnosis of ICD. Material for the study: leukocyte fraction and blood serum. The content of carbonyl products of oxidative modification of proteins was estimated by their reaction with 2.4-dinitrophenylhydrazine, followed by spectrophotometric registration of the interaction products-dinitrophenylhydrazones. When determining the content of primary and secondary products of lipid peroxidation, a method based on the phenomenon of rearrangement of double bonds into diene conjugates during the peroxidation of polyunsaturated fatty acids was used. Statistical processing of the obtained results was carried out by standard methods of nonparametric statistics using the Statistica 8.0 for Windows software package.
 RESULTS: In the structure of infections transmitted by ixodic ticks, ixodic tick-borne borreliosis was most often registered (50.5%), tick-borne encephalitis was observed in 44.8% of cases, mixed infection ― in 4.7%. Borrelia miyamotoi DNA was detected by PCR-RV in 8.6% of biological samples (blood serum, leukocyte fraction). When analyzing the results of oxidative modification of proteins and lipid peroxidation, a reliable picture of oxidative stress is observed, which is more pronounced in patients with ixodic tick-borne borreliosis.
 CONCLUSION: The revealed changes in the study of oxidative stress in patients with tick-borne encephalitis and ixodic tick-borne borreliosis not only indicate the prospects of developing new approaches to the pathogenetic therapy of tick-borne infections, providing for the use of antioxidants in complex therapy, but also suggest a greater effectiveness of direct-acting lipophilic antioxidants that limit diene conjugation, and thereby prevent the accumulation of secondary cytotoxic products of lipid peroxidation.

Erythrocytes of Little Ground Squirrels Undergo Reversible Oxidative Stress During Arousal From Hibernation.

The hibernation of small mammals is characterized by long torpor bouts alternating with short periods of arousal. During arousal, due to a significant increase in oxygen consumption, tissue perfusion, and the launch of thermogenesis in cells, a large amount of reactive oxygen species (ROS) and nitrogen (RNS) can be formed, which can trigger oxidative stress in cells. To estimate this possibility, we studied the intensity of free-radical processes in the red blood cells (RBCs) of little ground squirrels (LGS; Spermophilus pygmaeus) in the dynamics of arousal from hibernation. We found that in the torpid state, the degree of generation of ROS and RNS (8.3%, p>0.09; 20.7%, p<0.001, respectively), the degree of oxidative modification of membrane lipids and RBC proteins is at a low level (47%, p<0.001; 82.7%, p<0.001, respectively) compared to the summer control. At the same time, the activity of superoxide dismutase (SOD) and catalase (CAT) in RBC is significantly reduced (32.8%, p<0.001; 22.2%, p<0.001, respectively), but not the level of glutathione (GSH). In the torpid state, SOD is activated by exogenous GSH in concentration-dependent manner, which indicates reversible enzyme inhibition. During the arousal of ground squirrels, when the body temperature reaches 25°C, RBCs are exposed oxidative stress. This is confirmed by the maximum increase in the level of uric acid (25.4%, p<0.001) in plasma, a marker of oxidative modification of lipids [thiobarbituric acid reactive substances (TBARS); 82%, p < 0.001] and proteins (carbonyl groups; 499%, p < 0.001) in RBC membranes, as well as the decrease in the level of GSH (19.7%, p < 0.001) in erythrocytes relative to the torpid state and activity of SOD and CAT in erythrocytes to values at the Tb 20°C. After full recovery of body temperature, the level of GSH increases, the ratio of SOD/CAT is restored, which significantly reduces the degree of oxidative damage of lipids and proteins of RBC membranes. Thus, the oxidative stress detected at Tb 25°C was transient and physiologically regulated.

Enzymatic lysine oxidation as a posttranslational modification.

Oxidoreductases catalyze oxidation-reduction reactions and comprise a very large and diverse group of enzymes, which can be subclassified depending on the catalytic mechanisms of the enzymes. One of the most prominent oxidative modifications in proteins is carbonylation, which involves the formation of aldehyde and keto groups in the side chain of lysines. This modification can alter the local macromolecular structure of proteins, thereby regulating their function, stability, and/or localization, as well as the nature of any protein-protein and/or protein-nucleic acid interactions. In this review, we focus on copper-dependent amine oxidases, which catalyze oxidative deamination of amines to aldehydes. In particular, we discuss oxidation reactions that involve lysine residues and that are regulated by members of the lysyl oxidase (LOX) family of proteins. We summarize what is known about the newly identified substrates and how this posttranslational modification regulates protein function in different contexts.

The study of oxidative stress indicators in rats with a simulated acute hepatitis and correction with a thick extract from reishi mushrooms

The aim. To study the effect of a dry extract from reishi mushrooms on the activity of lipoperoxidation and oxidative modification of proteins under the conditions of a simulated paracetamol hepatitis in rats.&#x0D; Materials and methods. The study was performed on white male rats. The animals were divided into 10 groups, each included 6 animals. Acute hepatitis was simulated by the intragastric administration of paracetamol in the dose of 1250 mg/kg once per day (for 2 days). Correction of the pathology induced was performed with a dry extract of reishi mushrooms in the dose of 100 mg/kg of the body weight. The reference drug “Silybor” was administered in the dose of 20 mg/kg of the animal body weight. On Day 3, 7 and 10 from the beginning of the lesion, rats were euthanized using sodium barbamyl. The liver homogenate and blood serum were used for the studies. The activity of free radical oxidation processes under the conditions of acute toxic hepatitis and after the introduction of corrective factors was assessed by superoxide dismutase, catalase activity, the content of TBA-AP and OMP products.&#x0D; Results and discussion. The development of acute paracetamol hepatitis in rats and damage of hepatocyte membranes are indicated by an increase in the content of TBA-active products, products of oxidative modification of neutral and basic proteins in the serum and liver of animals. Simultaneously, a decrease in the activity of catalase and superoxide dismutase was observed. After correction of the pathology induced with a dry extract of reishi mushrooms a significant increase in the activity of antioxidant enzymes, a decrease in the content of lipid peroxidation products and oxidative modification of proteins in the serum and liver of the affected animals were observed.&#x0D; Conclusions. It has been experimentally proven that the use of dry extract of Reishi mushrooms in paracetamol hepatitis in rats caused a significant decrease in catalase and superoxide dismutase activity, a decrease in TBA-AP, neutral and basic 2,4-DNPH in the serum and liver of animals. The results of the research indicate an effective impact of reishi mushrooms dry extract on the normalization of lipoperoxidation, oxidative modification of proteins and antioxidant protection

Oxidative Post-Translational Modifications: A Focus on Cysteine S-Sulfhydration and the Regulation of Endothelial Fitness.

Significance: Changes in the oxidative balance can affect cellular physiology and adaptation through redox signaling. The endothelial cells that line blood vessels are particularly sensitive to reactive oxygen species, which can alter cell function by a number of mechanisms, including the oxidative post-translational modification (oxPTM) of proteins on critical cysteine thiols. Such modifications can act as redox-switches to alter the function of targeted proteins. Recent Advances: Mapping the cysteine oxPTM proteome and characterizing the effects of individual oxPTMs to gain insight into consequences for cellular responses has proven challenging. A recent addition to the list of reversible oxPTMs that contributes to cellular redox homeostasis is persulfidation or S-sulfhydration. Critical Issues: It has been estimated that up to 25% of proteins are S-sulfhydrated, making this modification almost as abundant as phosphorylation. In the endothelium, persulfides are generated by the trans-sulfuration pathway that catabolizes cysteine and cystathionine to generate hydrogen sulfide (H2S) and H2S-related sulfane sulfur compounds (H2Sn). This pathway is of particular importance for the vascular system, as the enzyme cystathionine γ lyase (CSE) in endothelial cells accounts for a significant portion of total vascular H2S/H2Sn production. Future Directions: Impaired CSE activity in endothelial dysfunction has been linked with marked changes in the endothelial cell S-sulfhydrome and can contribute to the development of atherosclerosis and hypertension. It will be interesting to determine how changes in the S-sulfhydration of specific networks of proteins contribute to endothelial cell physiology and pathophysiology. Antioxid. Redox Signal. 35, 1494-1514.

Біохімічні маркери вільнорадикального окиснення та обміну ліпідів у щурів з ожирінням, йододефіцитом та ожирінням у поєднанні з йододефіцитом

The purpose of the study was the content of lipid and protein peroxidation products, lipid spectrum parameters and the level of aminotransferases in obese, iodine deficient and obese rats in combination with iodine deficiency. Materials and methods. The study was performed on 45 white nonlinear rats weighing 120-180 g, which were divided into three experimental groups: obese rats (1st experimental group, n = 15), iodine-deficient animals (2nd experimental group), obese animals in combined with iodine deficiency (3rd experimental group, n = 15). The control group consisted of 15 intact rats. The content of products of lipid peroxidation and oxidative modification of proteins was determined in the blood and liver tissue of rats. Blood lipid spectrum was assessed by serum levels of triacylglycerols, total cholesterol, high-density lipoproteins and low-density lipoproteins, followed by calculation of the atherogenic factor. The activity of aspartate aminotransferase and alanine aminotransferase was determined in the blood. Results and discussion. It was found that in the liver tissue of rats and blood of experimental groups the content of lipid hydroperoxides and active products that react with thiobarbituric acid increases, which indicates the activation of lipoperoxidation processes. A variety of changes in protein peroxidation in both blood serum and liver tissue of animals of experimental groups was revealed. Regarding the lipid spectrum, the most pronounced differences in the indicators in relation to the control were found in obese animals in combination with iodine deficiency. In this group of animals, cholesterol was increased by 65% in reference to control, triacylglycerol content increased by 52%, low-density lipoprotein exceeded control by 60%, and high-density lipoprotein decreased by 61% in reference to control. The highest activity of aspartate aminotransferase was found in the group of animals with iodine deficiency, and alanine aminotransferase – in the group of obese animals. Conclusion. In the blood and liver tissue of rats with obesity, iodine deficiency and obesity in combination with iodine deficiency increases the content of products of free radical oxidation. The content of cholesterol, triacylglycerols, low-density lipoproteins increases in the blood, the content of high-density lipoproteins decreases, the activity of aspartate aminotransferase and alanine aminotransferase increases. The most pronounced differences in the indicators in reference to the control were found in obese animals in combination with iodine deficiency

Інтенсивна терапія новонароджених: удосконалення підходів корекції ренальних порушень за умови перинатальної патології

Актуальність. З урахуванням важливої ролі сечовидільної системи в забезпеченні стабільності гомеостазу цілого організму та високої частоти ренальної дисфункції в доношених новонароджених дітей із патологічним перебігом постнатальної адаптації лікувальна тактика пацієнтів неонатальних відділень інтенсивної терапії вимагає системного підходу та спрямована на протекцію життєво важливих функцій, у тому числі на запобігання тяжким нирковим пошкодженням та їх віддаленим наслідкам. Мета дослідження: удосконалити комплекс інтенсивної терапії новонароджених із тяжкими формами перинатальної патології за наявності порушень функціонального стану сечовидільної системи. Матеріали та методи. Проведено комплексне клініко-параклінічне обстеження 100 доношених новонароджених дітей із перинатальною патологією тяжкого ступеня, з яких 60 дітям було призначено удосконалений терапевтичний комплекс (основна група), 40 дітей отримували загальноприйняту терапію (група порівняння). Новонародженим основної групи разом із традиційними заходами стабілізації гомеостазу було призначено препарат групи метилксантинів, діючою речовиною якого є теофілін, для запобігання аденозиніндукованій ренальній вазоконстрикції та препарат комплексної антигіпоксичної й антиоксидантної дії Цитофлавін. Результати. Застосування удосконаленого комплексу лікування порівняно з традиційною терапією надало змогу суттєво покращити якість функціонування сечовидільної системи при тяжких формах перинатальної патології, зокрема зменшити частоту випадків формування гострого пошкодження нирок. При лікуванні новонароджених відмічалися зростання погодинного діурезу, зменшення рівня креатиніну в сироватці крові, збільшення швидкості клубочкової фільтрації, покращання основних допплерометричних показників ренального кровотоку та стабілізація балансу маси тіла. Стимуляція антиоксидантного ефекту захисту організму підтверджувалася суттєвим зменшенням рівня малонового альдегіду в еритроцитах та окисної модифікації білків у плазмі крові, збільшенням активності глюкозо-6-фосфатдегідрогенази в еритроцитах, глутатіонредуктази та глутатіон-S-трансферази в плазмі крові. Висновки. Результати проведеного дослідження засвідчили доцільність використання призначеного комплексу лікування разом із традиційними терапевтичними заходами, що підтверджується нормалізацією становлення ренальних функцій за умови перинатальної гіпоксії та зменшенням тяжкості перебігу нозологічної патології в новонароджених дітей у ранньому неонатальному періоді.

Гістохімічне дослідження процесів окиснювальної модифікації білків та обмеженого протеолізу в ендотелії судин міометрію у проекції плацентарного ложа матки при залізодефіцитній анемії вагітних

Utero-placental bed is the cumulation of gestationally altered endometrium at the place of ovum attachment to the uterine wall. As far as the protein oxidative modification and limited proteolysis in iron deficiency anemia are due to the fact that in conditions of hypoxia, free radical processes in the blood and tissues are enhanced, and iron deficiency is additionally able to cause hemodynamic disorders because of endothelial dysfunction in the vessels of the utero-placental area. The purpose of the study was to establish histochemical features of protein oxidative modification and limited proteolysis in the endotheliocytes of myometrial vessels in the projection of the utero-placental area depending on the degree of iron deficiency anemia in pregnant women. Materials and methods. By histochemical methods of Mikel Calvo, using reactions with bromophenol blue on "acidic" and "basic" proteins, and the method of A. Yasumа and T. Ichikawa, ninhydrin-Schiff reaction to free amino groups of proteins to assess the degree of limited proteolysis, in combination with computer microspectrophotometry and microdensitometry, quantitative characteristics of oxidative modification of proteins and limited proteolysis in endotheliocytes of myometrial segments of the utero-placental vessels in iron deficiency anemia of pregnant women were established. 74 biopsies of the observed uterine-placental area in physiological pregnancy and gestation based on iron deficiency anemia of I, II and III degrees of severity were investigated. Results and discussion. In physiological pregnancy, the intensity of oxidative modification of proteins and limited proteolysis is the lowest in endotheliocytes of myometrial segments of the spiral arteries and the highest one is in the endothelium of the vessels of the microcirculatory tract of the utero-placental area. In gestations based on iron deficiency anemia, intensification of proteins oxidative modification and limited proteolysis in the endothelium of all types of myometrial vessels of the projection of the utero-placental bed correlates with the severity of anemia. Iron deficiency anemia greatly affects the modification of proteins in the endothelial cells mostly of myometrial segments of spiral arteries of the placental bed. Conclusion. Intensification of protein oxidative modification and limited proteolysis in endotheliocytes of all type vessels of myometrium of the uterine-placental area formed by iron deficiency can be considered as a significant factor of endothelial dysfunction and a predictor of hemodynamic disorders of the placental bed

Cisd2 Preserves the Youthful Pattern of the Liver Proteome during Natural Aging of Mice.

Cisd2 (CDGSH iron sulfur domain 2) is a pro-longevity gene that extends the lifespan and health span of mice, ameliorates age-associated structural damage and limits functional decline in multiple tissues. Non-alcoholic fatty liver disease (NAFLD), which plays an important role in age-related liver disorders, is the most common liver disease worldwide. However, no medicines that can be used to specifically and effectively treat NAFLD are currently approved for this disease. Our aim was to provide pathological and molecular evidence to show that Cisd2 protects the liver from age-related dysregulation of lipid metabolism and protein homeostasis. This study makes four major discoveries. Firstly, a persistently high level of Cisd2 protects the liver from age-related fat accumulation. Secondly, proteomics analysis revealed that Cisd2 ameliorates age-related dysregulation of lipid metabolism, including lipid biosynthesis and β-oxidation, in mitochondria and peroxisomes. Thirdly, Cisd2 attenuates aging-associated oxidative modifications of proteins. Finally, Cisd2 regulates intracellular protein homeostasis by maintaining the functionality of molecular chaperones and protein synthesis machinery. Our proteomics findings highlight Cisd2 as a novel molecular target for the development of therapies targeting fatty liver diseases, and these new therapies are likely to help prevent subsequent malignant progression to cirrhosis and hepatocellular carcinoma.