Chronomics of circulating plasma lipid peroxides and anti-oxidant enzymes and other related molecules in cirrhosis of liver

The Influence of Circadian Rhythm on the Activity of Oxidative Stress Enzymes

The circadian system synchronizes daily with the day-night cycle of our environment. Disruption of this rhythm impacts the emergence and development of many diseases caused, for example, by the overproduction of free radicals, leading to oxidative damage of cellular components. The goal of this study was to determine the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione transferase (GST), glutathione reductase (R-GSSG), and the concentration of glutathione (GSH) in the circadian rhythm. The study group comprised 66 healthy volunteers (20-50 years; 33 women; 33 men). The blood was collected at 2, 8 a.m., and 2, 8 p.m. All samples marked the serum melatonin concentration to confirm the correct sleeping rhythm and wakefulness throughout the day. The activity of study enzymes and the concentration of GSH were measured by the spectrophotometric method. Confirmed the existence of circadian regulation of oxidative stress enzymes except for GST activity. The peak of activity of study enzymes and GSH concentration was observed at 2 a.m. The increased activity of enzymes and the increase in GSH concentration observed at night indicate that during sleep, processes allowing to maintain of the redox balance are intensified, thus limiting the formation of oxidative stress.

Snoring and napping independently increased the serum uric acid levels and hyperuricemia risk: The Henan Rural Cohort Study

BACKGROUND AND AIMS

Evidence on the association of snoring, daily sleep duration (daytime napping and night sleep duration) with hyperuricemia (HUA) was limited, especially in the resources-poor areas. This study aimed to investigate the independent effect of snoring frequency and daily sleep duration on HUA prevalence in rural Chinese adults.

METHODS AND RESULTS

29,643 participants aged 18-79 years were included in the final cross-sectional analysis from the Henan Rural Cohort Study. Multivariate logistic regression and linear regression models with HUA and serum uric acid (SUA) levels as dependent variables were conducted, respectively. Of the 29,643 included adults, 3498 suffered from HUA. Compared to never snoring, the adjusted odds ratio (OR) and 95% confidence interval (CI) of HUA for rare snoring, occasional snoring, and habitual snoring were 1.35 (1.17, 1.56), 1.30 (1.14, 1.47), and 1.59 (1.47, 1.73), respectively (P for trend <0.001). Compared with no napping, participants who had daytime napping of 61-90 and > 91 min were associated with a 29% and 30% increase in the prevalence of HUA, respectively (P for trend <0.001). But in night sleep duration groups, no significant associations were observed. The positive associations between snoring and HUA were attenuated in people aged ≥65 and people with type 2 diabetes mellitus (both P for interaction <0.05).

CONCLUSION

Habitual snoring or longer daytime napping was independently associated with increased HUA prevalence and SUA levels in rural Chinese adults, which indicates the significance of early intervention and treatment of snoring and longer daytime napping to prevent hyperuricemia.

Daytime Napping Duration Is Positively Associated With Risk of Hyperuricemia in a Chinese Population

CONTEXT

Loss of sleep or disturbance of sleep-wake cycles has been related to metabolic impairments. However, few studies have investigated the association between daily sleep duration and hyperuricemia.

OBJECTIVE

We investigated daily sleep duration (daytime napping and nocturnal sleep) with hyperuricemia risk.

METHODS

We cross-sectionally analyzed data from the China Multi-Ethnic Cohort (CMEC), Yunnan region. A total of 22 038 participants aged 30 to 79 years were recruited in 2018. Hyperuricemia was defined as serum uric acid (SUA) above 7.0 mg/dL in men and above 6.0 mg/dL in women. Outcomes were associations between daily sleep duration and hyperuricemia.

RESULTS

We found that the longest daytime napping duration was associated with a higher risk of hyperuricemia in the crude model (odds ratio [OR] [95% CI], 2.22 [1.88-2.61], P < .001) and in a multivariable adjustment model (OR, 1.69; 95% CI, 1.41-2.01, P < .001) after adjusting for demographic, sleep habits, and metabolic risk factors. The association was moderately attenuated with additionally adjusted for serum creatinine (OR, 1.54; 95% CI, 1.28-1.86, P < .001). Longer daytime napping duration was also related to higher risk of hyperuricemia combined with metabolic syndrome (MetS). Respondents in the group with daytime napping duration greater than or equal to 90 minutes presented with a higher risk of hyperuricemia combined with MetS (OR, 1.39; 95% CI, 1.06-1.79; P < .001) in the fully adjusted model. We did not observe any relation between nocturnal sleep duration and risk of hyperuricemia in the study.

CONCLUSION

Longer daytime napping duration (but not nocturnal sleep duration) was independently associated with risk of hyperuricemia in a Chinese population.

Chronic Exposure to Continuous Brightness or Darkness Modulates Immune Responses and Ameliorates the Antioxidant Enzyme System in Male Rats

Circadian rhythms are considered vital regulators of immune functions. This study aims to elucidate the effects of chronic circadian disruption on immune functions, clock genes expression, and antioxidant enzymes levels in lymphoid tissues. Adult male Sprague-Dawley rats were subjected to a normal light/dark cycle or either continuous light (LL) or continuous dark (DD) for 8 weeks. The results demonstrated (1) significant decreases in the circulating levels of interleukin 1β, interleukin 6 and tumor necrosis factor alpha (TNF-α) and significant increases in the levels of interleukin 10, interleukin 12, C-reactive protein (CRP) and corticosterone in both LL and DD groups; (2) upregulation in mRNA expression of core clock genes Cry1, Cry2, Per1, Per2, and Per3 in the spleen of the DD group and downregulation in Cry1 and Cry2 genes in the LL group; (3) elevation of total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), nitric oxide (NO) and the lipid peroxidation marker malondialdehyde (MDA) in the spleen, lymph node and bone marrow of both the LL and DD groups and decreases in the levels of the same markers in the thymus of the LL group; (4) decreased numbers of CD4⁺ and CD8⁺ cells in lymphoid tissues of both the LL and the DD groups; (5) reduced platelets count and suppressed immunoglobulin (IgM, IgE) in the LL and DD groups with marked erythropenia and leukocytosis in the DD group. Taken together, circadian misalignment leads to hematological disruptions, dysregulation of clock genes, and inflammatory mediators, which further enhances the antioxidant enzyme system that is crucial for an organism's adaptation to stresses.

Peroxisome Proliferator-Activated Receptors as Molecular Links between Caloric Restriction and Circadian Rhythm

The circadian rhythm plays a chief role in the adaptation of all bodily processes to internal and environmental changes on the daily basis. Next to light/dark phases, feeding patterns constitute the most essential element entraining daily oscillations, and therefore, timely and appropriate restrictive diets have a great capacity to restore the circadian rhythm. One of the restrictive nutritional approaches, caloric restriction (CR) achieves stunning results in extending health span and life span via coordinated changes in multiple biological functions from the molecular, cellular, to the whole-body levels. The main molecular pathways affected by CR include mTOR, insulin signaling, AMPK, and sirtuins. Members of the family of nuclear receptors, the three peroxisome proliferator-activated receptors (PPARs), PPARα, PPARβ/δ, and PPARγ take part in the modulation of these pathways. In this non-systematic review, we describe the molecular interconnection between circadian rhythm, CR-associated pathways, and PPARs. Further, we identify a link between circadian rhythm and the outcomes of CR on the whole-body level including oxidative stress, inflammation, and aging. Since PPARs contribute to many changes triggered by CR, we discuss the potential involvement of PPARs in bridging CR and circadian rhythm.

Tanshinone IIA exerts therapeutic effects by acting on endogenous stem cells in rats with liver cirrhosis

BACKGROUND AND OBJECTIVE

Liver cirrhosis (LC), the major pathway for the progression and development of chronic liver disease, is an advanced stage of liver disease. It is the third most common chronic noncommunicable disease after cardiovascular diseases and malignant tumors. Tanshinone IIA (Tan), an extract of Salvia miltiorrhiza (S. miltiorrhiza), has been proven to promote the proliferation and differentiation of stem cells. Moreover, its protective effect in liver injury has received widespread attention. The present study investigated whether Tan plays a therapeutic role in LC by promoting endogenous stem cell proliferation and differentiation.

MATERIALS AND METHODS

LC models were established by intraperitoneal injection of an olive oil solution containing 50 % carbon tetrachloride (CCL₄) combined with 10 % alcohol in the drinking water. After successful model establishment, the animals were randomly divided into four groups and injected with physiological saline or low-, medium-, or high-dose (10, 20, or 40 mg/kg) Tan for seven consecutive days. The protective effect of Tan on LC was observed by western blotting, serological examination and histopathological staining. Furthermore, immunofluorescence double-labeling of 5-bromo-2-deoxyuridine (BrdU) and the liver cell markers albumin and CK-18 or the liver stem cell markers EPCAM and OV-6 was used to evaluate the proliferation and differentiation of endogenous liver stem cells.

RESULTS

We confirmed successful establishment of the LC model by observing transaminase levels and hematoxylin-eosin (HE) and Masson staining of liver sections in CCL₄-treated and healthy rats. After Tan treatment, HE and Masson staining of paraffin sections of liver tissue showed that Tan treatment significantly improved histological injury to the liver. Serological tests showed that albumin-bilirubin (ALBI) scores and models for end-stage liver disease (MELD) were lower. Immunofluorescence and immunohistochemical staining showed that the newly proliferated cells were colocalized with ALB, OV-6, EPCAM, and CK-18, indicating that new expression of these markers occurred after Tan injection. All results were most significant in the medium-dose treatment group.

CONCLUSION

Tan can alleviate liver injury induced by CCL₄ combined with alcohol in rats and plays a therapeutic role in LC by promoting the proliferation and differentiation of endogenous liver stem cells.

Effect of Morning vs. Evening Turmeric Consumption on Urine Oxidative Stress Biomarkers in Obese, Middle-Aged Adults: A Feasibility Study

The circadian rhythm of biological systems is an important consideration in developing health interventions. The immune and oxidative defense systems exhibit circadian periodicity, with an anticipatory increase in activity coincident with the onset of the active period. Spice consumption is associated with enhanced oxidative defense. The objective of this study was to test the feasibility of a protocol, comparing the effects of morning vs. evening consumption of turmeric on urine markers of oxidative stress in obese, middle-aged adults. Using a within-sample design, participants received each of four clock time x treatment administrations, each separated by one week: morning turmeric; evening turmeric; morning control; evening control. Participants prepared for each lab visit by consuming a low-antioxidant diet for two days and fasting for 12 h. Urine was collected in the lab at baseline and one-hour post-meal and at home for the following five hours. The results showed that the processes were successful in executing the protocol and collecting the measurements and that participants understood and adhered to the instructions. The findings also revealed that the spice treatment did not elicit the expected antioxidant effect and that the six-hour post-treatment urine collection period did not detect differences in urine endpoints across treatments. This feasibility study revealed that modifications to the spice treatment and urine sampling timeline are needed before implementing a larger study.

Effect of Light-Dark Cycle Misalignment on the Hypothalamic-Pituitary-Gonadal Axis, Testicular Oxidative Stress, and Expression of Clock Genes in Adult Male Rats

This study investigated the influence of circadian misalignment on the male reproductive system. Adult Sprague-Dawley male rats were exposed to prolonged light (20 h light : 4 h dark) or prolonged darkness (4 h light : 20 h dark) for 12 consecutive weeks. The somatic index of seminal vesicles and prostates increased due to prolonged light exposure. Sperm count and motility were enhanced solely by prolonged light exposure, whereas the percentage of sperm abnormalities was reduced by both prolonged light and darkness. The serum levels of reproductive hormones (follicle-stimulating hormone, luteinizing hormone, testosterone, and prolactin) were elevated, and the estradiol level was reduced by long-term light and dark exposure. Testicular total antioxidant capacity and antioxidant enzyme activities were improved, and lipid peroxidation was inhibited following chronic exposure to light or dark. Chronic light exposure increased, but chronic darkness decreased, testicular nitric oxide production. The mRNA expression of the hypothalamic and testicular clock genes including PER1-2, CRY1-2, BMAL1, CLOCK, and Rev-Erbα was altered by circadian disruption. Prolonged light exposure decreased the levels of thyroid hormones and suppressed the mRNA expression of adiponectin receptors 1 and 2. The immunohistochemical expression of proliferating cell nuclear antigen was decreased only by chronic darkness. The present study thus provides new insights into the physiological changes associated with long-term exposure to light or darkness, in which the expression levels of various clock gene mRNAs are modulated, reproductive hormones are increased, and the antioxidant enzyme system is ameliorated as mechanisms of adaptation to chronic circadian disruption.

Chronomics of Circulating Plasma Lipid Peroxides and Antioxidant Enzymes in Renal Stone Formers

The chronome of lipid peroxidation and anti-oxidant defense mechanisms may relate to the efficacy and management of time qualified preventive therapeutic and dietary interventions. One hundred renal stone patients, 20-60 years of age, and 50 clinically healthy volunteers, 21-45 years, were synchronized for 1 week with diurnal activity from 06:00 to 22:00 and nocturnal rest. All subjects took their usual meals three times daily (breakfast around 08:30, lunch around 13:00, and dinner around 20:30) with usual fluid intake. Drugs known to affect free radical system were not taken. Blood samples were collected at 6-h intervals for 24-h under standardized, presumably 24-h synchronized conditions. Determinations included plasma lipid peroxides, in terms of malondialdehyde (MDA) and blood superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CAT) activities. A marked circadian variation was demonstrated for each studied variable by population-mean cosinor in renal stone patients and healthy participants (p < 0.001). By comparison to healthy subjects, parameter tests indicate that the stone formers had a higher MESOR of MDA, but a lower MESOR of SOD, GPx, GR and CAT. Furthermore, the patients also differed from the healthy controls in terms of their circadian amplitude and acrophase (tested jointly) of all variables (p < 0.001). Mapping the broader time structure with multifrequency circadian characteristics of oxidants and anti-oxidants is needed for exploring their role as marker in the treatment and management of urolithiasis.

Night workers have lower levels of antioxidant defenses and higher levels of oxidative stress damage when compared to day workers

The effects of circadian misalignment and work shift on oxidative stress profile of shift workers have not been explored in the literature. The present study aimed to evaluate the role of shift work (day and night) and social jetlag - a measure of circadian misalignment - with oxidative stress markers. A cross-sectional study was performed with 79 men (21–65 years old, 27.56 ± 4.0 kg/m²) who worked the night shift (n = 37) or daytime (n = 42). The analyzed variables included anthropometric measures and determination of systemic levels of markers of oxidative damage and antioxidant defense. Social jetlag was calculated by the absolute difference between the mean sleep point on working and rest days. The night group presented higher systemic values of thiobarbituric acid reactive substances and hydrogen peroxide, and lower levels of nitrite, total antioxidant capacity, and catalase and superoxide dismutase activities in relation to the day group. However, social jetlag was not associated with oxidative stress-related biomarkers analyzed in the night group. These results suggest that the night worker has higher levels of oxidative stress damage and lower levels of antioxidant defenses, while social jetlag was not a possible responsible factor for this condition.

Neuroprotection afforded by circadian regulation of intracellular glutathione levels: A key role for miRNAs

Circadian rhythms are approximately 24-h oscillations of physiological and behavioral processes that allow us to adapt to daily environmental cycles. Like many other biological functions, cellular redox status and antioxidative defense systems display circadian rhythmicity. In the central nervous system (CNS), glutathione (GSH) is a critical antioxidant because the CNS is extremely vulnerable to oxidative stress; oxidative stress, in turn, causes several fatal diseases, including neurodegenerative diseases. It has long been known that GSH level shows circadian rhythm, although the mechanism underlying GSH rhythm production has not been well-studied. Several lines of recent evidence indicate that the expression of antioxidant genes involved in GSH homeostasis as well as circadian clock genes are regulated by post-transcriptional regulator microRNA (miRNA), indicating that miRNA plays a key role in generating GSH rhythm. Interestingly, several reports have shown that alterations of miRNA expression as well as circadian rhythm have been known to link with various diseases related to oxidative stress. A growing body of evidence implicates a strong correlation between antioxidative defense, circadian rhythm and miRNA function, therefore, their dysfunctions could cause numerous diseases. It is hoped that continued elucidation of the antioxidative defense systems controlled by novel miRNA regulation under circadian control will advance the development of therapeutics for the diseases caused by oxidative stress.

Periodic variation in bile acids controls circadian changes in uric acid via regulation of xanthine oxidase by the orphan nuclear receptor PPARα

Xanthine oxidase (XOD), also known as xanthine dehydrogenase, is a rate-limiting enzyme in purine nucleotide degradation, which produces uric acid. Uric acid concentrations in the blood and liver exhibit circadian oscillations in both humans and rodents; however, the underlying mechanisms remain unclear. Here, we demonstrate that XOD expression and enzymatic activity exhibit circadian oscillations in the mouse liver. We found that the orphan nuclear receptor peroxisome proliferator-activated receptor-α (PPARα) transcriptionally activated the mouse XOD gene and that bile acids suppressed XOD transactivation. The synthesis of bile acids is known to be under the control of the circadian clock, and we observed that the time-dependent accumulation of bile acids in hepatic cells interfered with the recruitment of the co-transcriptional activator p300 to PPARα, thereby repressing XOD expression. This time-dependent suppression of PPARα-mediated transactivation by bile acids caused an oscillation in the hepatic expression of XOD, which, in turn, led to circadian alterations in uric acid production. Finally, we also demonstrated that the anti-hyperuricemic effect of the XOD inhibitor febuxostat was enhanced by administering it at the time of day before hepatic XOD activity increased. These results suggest an underlying mechanism for the circadian alterations in uric acid production and also underscore the importance of selecting an appropriate time of day for administering XOD inhibitors.

Circadian Periodicity of Circulating Plasma Lipid Peroxides, Uric Acid and Ascorbic Acid in Renal Stone Formers

Circadian periodicity of plasma lipid peroxides and serum ascorbic acid and uric acid levels were studied in one hundred renal stone formers (55 women and 45 men; age 20-60 years) and 50 clinically healthy volunteers (21 women and 29 men; age 21-45 years) with diurnal activity from 06:00 to 22:00 and nocturnal rest. A marked circadian variation was demonstrated by population-mean-cosinor for all studied variables in stone formers and healthy subjects. By comparison to the healthy controls, parameter tests indicate that the stone formers had a higher MESOR (±SE) of MDA (2.90 ± 0.03 vs. 2.28 ± 0.06; F = 94.929, p < 0.001), a lower MESOR of serum ascorbic acid (0.722 ± 0.010 vs. 0.839 ± 0.10; F = 32.083, p < 0.001), and a similar MESOR of serum uric acid. Furthermore, the patients also differed from the healthy subjects in terms of their circadian amplitude and acrophase (tested jointly) of all three variables (p < 0.001). The demonstration herein of a circadian rhythm in MDA, serum ascorbic and uric acid suggests that these variables could also serve as markers to optimize the timing of treatment and to assess the patient's response to treatment for further management.

Circadian rhythm connections to oxidative stress: implications for human health

SIGNIFICANCE

Oxygen and circadian rhythmicity are essential in a myriad of physiological processes to maintain homeostasis, from blood pressure and sleep/wake cycles, down to cellular signaling pathways that play critical roles in health and disease. If the human body or cells experience significant stress, their ability to regulate internal systems, including redox levels and circadian rhythms, may become impaired. At cellular as well as organismal levels, impairment in redox regulation and circadian rhythms may lead to a number of adverse effects, including the manifestation of a variety of diseases such as heart diseases, neurodegenerative conditions, and cancer.

RECENT ADVANCES

Researchers have come to an understanding as to the basics of the circadian rhythm mechanism, as well as the importance of the numerous species of oxidative stress components. The effects of oxidative stress and dysregulated circadian rhythms have been a subject of intense investigations since they were first discovered, and recent investigations into the molecular mechanisms linking the two have started to elucidate the bases of their connection.

CRITICAL ISSUES

While much is known about the mechanics and importance of oxidative stress systems and circadian rhythms, the front where they interact has had very little research focused on it. This review discusses the idea that these two systems are together intricately involved in the healthy body, as well as in disease.

FUTURE DIRECTIONS

We believe that for a more efficacious management of diseases that have both circadian rhythm and oxidative stress components in their pathogenesis, targeting both systems in tandem would be far more successful.

Exacerbation of alcohol-induced oxidative stress in rats by polyunsaturated Fatty acids and iron load

The hypothesis that excessive intake of vegetable oil containing polyunsaturated fatty acids and iron load precipitate alcohol-induced liver damage was investigated in a rat model. In order to elucidate the mechanism underlying this synergism, the serum levels of iron, total protein, serum glutamate pyruvate transaminase, liver thiobarbituric acid reactive substances, and activities of antioxidant enzymes superoxide dismutase, catalase in liver of rats treated with alcohol, polyunsaturated fatty acids and iron per se and in combination were examined. Alcohol was fed to the rats at a level of 10-30% (blood alcohol was maintained between 150-350 mg/dl by using head space gas chromatography), polyunsaturated fatty acids at a level of 15% of diet and carbonyl iron 1.5-2% of diet per se and in combination to different groups for 30 days. Hepatotoxicity was assessed by measuring serum glutamate pyruvate transaminase, which was elevated and serum total protein, which was decreased significantly in rats fed with a combination of alcohol, polyunsaturated fatty acids and iron. It was also associated with increased lipid peroxidation and disruption of antioxidant defense in combination fed rats as compared to rats fed with alcohol or polyunsaturated fatty acids or iron. The present study revealed significant exacerbation of the alcohol-induced oxidative stress in presence of polyunsaturated fatty acids and iron.

Changes in advanced oxidation protein products, advanced glycation end products, and s-nitrosylated proteins, in patients affected by polycythemia vera and essential thrombocythemia

OBJECTIVES

Oxidative stress has a clear pro tumoral effect in myeloproliferative neoplasms (MPDs). In this study, we analyzed oxidative stress in patients with essential thrombocythemia (ET) and polycythemia vera (PV). Design and methods We analyzed serum levels of advanced oxidation protein products (AOPPs) degradation, advanced glycation end products (AGEs), and protein nitrosylation in ET and PV patients. We also evaluated neutrophil gelatinase-associated lipocalin (NGAL) levels, an acute phase protein isolated in human neutrophils, the activation status of platelets and leukocytes, and the JAK2 (V617F) mutation status.

RESULTS

AOPPs and s-nitrosylated proteins were significantly higher in PV and ET subjects as compared to healthy volunteers, while AGEs were higher in ET subjects with respect to controls. Moreover, in PV patients we found a correlation between s-nitrosylated proteins and Hb value. In ET patients AGEs were significantly higher in patients with thrombosis compared with those without thrombotic events.

CONCLUSIONS

Our results suggest that oxidative stress could play a role in the physiopathology of MPDs and in the onset of myeloproliferative associated thrombotic risk.

Relationship between advanced oxidation protein products, advanced glycation end products, and S-nitrosylated proteins with biological risk and MDR-1 polymorphisms in patients affected by B-chronic lymphocytic leukemia

The aim of our study was to analyze the serum levels of advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEs), and protein nitrosylation in patients with B-chronic lymphocytic leukemia (B-CLL). AOPPs, AGEs, and S-nitrosylated were increased in B-CLL patients. The mutation of IgVH gene, CD 38, and Zap 70 expression were not associated with increased oxidative stress. The mutant 2677GT genotype was found to be associated with higher AGEs levels with respect to wild-type genotype, while as far the C3435T MDR1 polymorphism is concerned, subjects presenting wild-type genotype showed higher values of AOPPs with respect to heterozygous genotype. Our results suggest that B-CLL is associated with oxidative stress.