Quantification of F2-isoprostanes by gas chromatography/mass spectrometry as a measure of oxidant stress

Oxidative Stress and Its Related Factors in Latent Autoimmune Diabetes in Adults

AIMS

Few research was reported to explore oxidative stress in individuals with latent autoimmune diabetes in adults (LADA). Therefore, our goal is to study oxidative stress and related factors in LADA patients.

METHODS

In this study, 250 Chinese inpatients were diagnosed with LADA (n = 110) and type 2 diabetes mellitus (n = 140) and 140 healthy volunteers were recruited. Moreover, individuals with LADA were followed for 6 months to evaluate whether short-term glycemic control during hospitalization can improve oxidative stress. Clinical and laboratory measurements of height, weight, blood pressure, glycosylated hemoglobin (HbA1c), blood lipids, 8-isoprostaglandin F2α (8-iso-PGF2α), and superoxide dismutase (SOD) were performed. Stepwise multiple regression analyses were used to assess factors that related to oxidative stress in individuals with LADA.

RESULTS

Compared with patients with type 2 diabetes, individuals with LADA have better oxidative stress and worse oxidative stress than healthy volunteers. After multiple regression analyses, systolic blood pressure, HbA1c, duration of diabetes, and diabetic retinopathy were associated with 8-iso-PGF2α and HbA1c. Diabetic retinopathy and diabetic ketosis were associated with SOD in individuals with LADA. Our results also revealed that, after 6 months of follow-up, oxidative stress was improved to some extent in persons with LADA.

CONCLUSIONS

Our results show that compared with type 2 diabetes, LADA means less oxidative stress, and compared with healthy volunteers, it means more oxidative stress. Systolic blood pressure, HbA1c, duration of diabetes, diabetic retinopathy, and ketosis were associated with oxidative stress in individuals with LADA. Furthermore, short-term glycemic control can improve oxidative stress to some extent in individuals with LADA.

A Review of Oxidative Stress Products and Related Genes in Early Alzheimer's Disease

Oxidative stress is associated with the progression of Alzheimer’s disease (AD). Reactive oxygen species can modify lipids, DNA, RNA, and proteins in the brain. The products of their peroxidation and oxidation are readily detectable at incipient stages of disease. Based on these oxidation products, various biomarker-based strategies have been developed to identify oxidative stress levels in AD. Known oxidative stress-related biomarkers include lipid peroxidation products F2-isoprostanes, as well as malondialdehyde and 4-hydroxynonenal which both conjugate to specific amino acids to modify proteins, and DNA or RNA oxidation products 8-hydroxy-2’-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG), respectively. The inducible enzyme heme oxygenase type 1 (HO-1) is found to be upregulated in response to oxidative stress-related events in the AD brain. While these global biomarkers for oxidative stress are associated with early-stage AD, they generally poorly differentiate from other neurodegenerative disorders that also coincide with oxidative stress. Redox proteomics approaches provided specificity of oxidative stress-associated biomarkers to AD pathology by the identification of oxidatively damaged pathology-specific proteins. In this review, we discuss the potential combined diagnostic value of these reported biomarkers in the context of AD and discuss eight oxidative stress-related mRNA biomarkers in AD that we newly identified using a transcriptomics approach. We review these genes in the context of their reported involvement in oxidative stress regulation and specificity for AD. Further research is warranted to establish the protein levels and their functionalities as well as the molecular mechanisms by which these potential biomarkers are involved in regulation of oxidative stress levels and their potential for determination of oxidative stress and disease status of AD patients.

The inhibitory effect of manganese on acetylcholinesterase activity enhances oxidative stress and neuroinflammation in the rat brain

BACKGROUND

Manganese (Mn) is a naturally occurring element and an essential nutrient for humans and animals. However, exposure to high levels of Mn may cause neurotoxic effects. The pathological mechanisms associated with Mn neurotoxicity are poorly understood, but several reports have established it is mediated, at least in part, by oxidative stress.

OBJECTIVES

The present study was undertaken to test the hypothesis that a decrease in acetylcholinesterase (AChE) activity mediates Mn-induced neurotoxicity.

METHODS

Groups of 6 rats received 4 or 8 intraperitoneal (i.p.) injections of 25mg MnCl(2)/kg/day, every 48 h. Twenty-four hours after the last injection, brain AChE activity and the levels of F(2)-isoprostanes (F(2)-IsoPs) and F(4)-neuroprostanes (F(4)-NPs) (biomarkers of oxidative stress), as well as prostaglandin E(2) (PGE(2)) (biomarker of neuroinflammation) were analyzed.

RESULTS

The results showed that after either 4 or 8 Mn doses, brain AChE activity was significantly decreased (p<0.05), to 60 ± 16% and 55 ± 13% of control levels, respectively. Both treated groups exhibited clear signs of neurobehavioral toxicity, characterized by a significant (p<0.001) decrease in ambulation and rearings in open-field. Furthermore, Mn treatment caused a significant increase (p<0.05) in brain F(2)-IsoPs and PGE(2) levels, but only after 8 doses. In rats treated with 4 Mn doses, a significant increase (p<0.05) in brain F(4)-NPs levels was found. To evaluate cellular responses to oxidative stress, we assessed brain nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) and Mn-superoxide dismutase (Mn-SOD, SOD2) protein expression levels. A significant increase in Mn-SOD protein expression (p<0.05) and a trend towards increased Nrf2 protein expression was noted in rat brains after 4 Mn doses vs. the control group, but the expression of these proteins was decreased after 8 Mn doses. Taken together, these results suggest that the inhibitory effect of Mn on AChE activity promotes increased levels of neuronal oxidative stress and neuroinflammatory biomarkers.