Association Between Selenium and Malondialdehyde as an Efficient Biomarker of Oxidative Stress in Infantile Cardiac Surgery

Pioglitazone protects PC12 cells against oxidative stress injury: An in vitro study of its antiapoptotic effects via the PPARγ pathway

To the best of our knowledge, the role of peroxisome proliferator-activated receptor γ (PPARγ) in oxidative stress-induced PC12 cell damage is unknown. Using a PC12 cell model with H2O2 treatment, the present study investigated the expression levels of apoptosis-related genes and neuronal apoptosis after oxidative stress injury. The present study further investigated the protective effect and mechanism of pioglitazone, a PPARγ agonist. PC12 cells treated with H2O2 were used as a model of oxidative stress injury. An MTT assay and flow cytometry were used to detect the effect of H2O2 on PC12 cell viability and the protective effect of pioglitazone. A TUNEL assay was used to detect neuronal apoptosis. The expression levels of PPARγ, Bax, Bcl-2 and caspase-3 were examined by reverse transcription-quantitative PCR and western blotting. H2O2 reduced PC12 cell viability in a dose- and time-dependent manner. H2O2 significantly upregulated the protein expression levels of Bax and the cleaved caspase-3/caspase-3 ratio (P<0.01), decreased the protein expression levels of Bcl-2 (P<0.01), and increased the apoptosis rate of PC12 cells. Pioglitazone significantly reduced the protein expression levels of Bax and the cleaved caspase-3/caspase-3 ratio (P<0.01), increased the expression levels of Bcl-2 (P<0.01), decreased the Bax/Bcl-2 expression ratio (P<0.01) and increased the viability of H2O2-damaged PC12 cells in a dose-dependent manner. Treatment with the PPARγ antagonist GW9662 or PPARγ small interfering RNA counteracted the protective effect of pioglitazone on PC12 cells to different extents (P<0.01). Therefore, the present study reported the role of PPARγ in protecting PC12 cells against oxidative stress injury, which may lead to novel therapeutic approaches for neurodegenerative diseases.

Association Between the Ratios of Selenium to Several Elements and Mild Cognitive Impairment in the Elderly

To investigate the relationship between the correlation ratios of selenium (Se) and other elements and mild cognitive impairment (MCI) among older adults. A total of 1000 individuals participated in our research analysis. The concentrations of elements in whole blood were determined using inductively coupled plasma mass spectrometry to reflect their exposure levels. Participants' cognitive function was assessed using the Mini-Mental State Examination. Logistic regression analysis was used to evaluate the relationship between elemental ratios and MCI. Se concentration was positively correlated with red blood cell count (r = 0.219, p < 0.001), haemoglobin level (r = 0.355, p < 0.001), haematocrit (r = 0.215, p < 0.001), mean corpuscular haemoglobin (r = 0.294, p < 0.001) and mean corpuscular haemoglobin concentration (r = 0.428, p < 0.001) and negatively correlated with red cell volume distribution width-standard deviation (r = -0.232, p < 0.001) and platelet distribution width (r = -0.382, p < 0.001). Compared with the normal group, the ratios of Se/vanadium (V), Se/lead (Pb) and Se/cadmium (Cd) in the whole blood of the MCI group were significantly lower (all p < 0.001), while the ratios of manganese (Mn)/Se and iron (Fe)/Se were higher (all p < 0.001). The increase in the ratios of Se/V, Se/Pb and Se/Cd is related to a decreased risk of MCI among older adults; contrarily, an increase in the ratios of Mn/Se and Fe/Se may be a risk factor for MCI.

Combination of sodium butyrate and probiotics ameliorates severe burn-induced intestinal injury by inhibiting oxidative stress and inflammatory response

Burns are a common traumatic injuries with considerable morbidity and mortality rates. Post-burn intestinal injuries are closely related to oxidative stress and inflammatory response. The aim of the current study was to investigate the combined effect of sodium butyrate (NaB) and probiotics (PROB) on severe burn-induced oxidative stress and inflammatory response and the underlying mechanism of action. Sprague-Dawley rats with severe burns were treated with NaB with or without PROB. Pathomorphology of skin and small intestine tissue was observed using hematoxylin and eosin staining and severe burn-induced apoptosis in small intestine tissue was examined via terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The release of factors related to inflammation was quantified using ELISA kits and qRT-PCR and levels of oxidative stress markers were evaluated using biochemical assays. Furthermore, mitochondrial morphological changes in small intestinal epithelial cells were observed using transmission electron microscopy. In addition, the underlying mechanism associated with the combined effect of NaB and PROB on severe burn-induced oxidative stress and inflammatory response was investigated using western blotting. The combination of NaB and PROB exerted protective effects against severe burn-induced intestinal barrier injury by reducing the levels of diamine oxidase and intestinal fatty acid binding protein. Combined NaB and PROB treatment inhibited severe burn-induced oxidative stress by increasing superoxide dismutase levels and decreasing those of malondialdehyde and myeloperoxidase levels. Severe burn-induced inflammation was suppressed by combined NaB and PROB administration, as demonstrated by the decreased mRNA expression of tumor necrosis factor-α, interleukin-6, interleukin-1β, and high mobility group box-1 in the small intestine. In addition, this study showed that combined NaB and PROB administration increased nuclear factor-erythroid 2-related factor 2 (Nrf2) protein expression and decreased the phosphorylation of nuclear factor (NF)-κB and extracellular signal-regulated kinase 1/2 (ERK 1/2). In conclusion, our findings indicate that combined NaB and PROB treatment may inhibit severe burn-induced inflammation and oxidative stress in the small intestine by regulating HMGB1/NF-κB and ERK1/2/Nrf2 signaling, thereby providing a new therapeutic strategy for intestinal injury induced by severe burn.

Dietary Selenium Alleviated Mouse Liver Oxidative Stress and NAFLD Induced by Obesity by Regulating the KEAP1/NRF2 Pathway

Nonalcoholic fatty liver disease (NAFLD) occurs when excess fat is stored in the liver and it is strongly linked with metabolic syndrome and oxidative stress. Selenium (Se) is an essential micronutrient in animals, which has a variety of biological functions, including antioxidant and anti-inflammatory. However, the exact effect of dietary selenium on NAFLD and the underlying molecular mechanism are not yet clear. Herein, we fed a high-fat diet (HFD) to C57BL/6 mice to construct an in vivo NAFLD model, treated AML-12 cells with palmitic acid (PA) to construct an in vitro NAFLD model, and AML-12 cells were stimulated with H₂O₂ to induce hepatocyte oxidative stress and then treated with adequate selenium. We observed that adequate selenium significantly improved the hepatic injury and insulin resistance in HFD mice, and decreased the fat accumulation and the expression of lipogenic genes in PA-induced AML-12 cells. Meanwhile, selenium significantly inhibited the production of reactive oxygen species (ROS), inhibited apoptosis, and restored mitochondrial number and membrane potential in PA- induced AML-12 cells. In addition, selenium can promote selenoproteinP1 (SEPP1) synthesis to regulate the Kelch-like ECH-associated protein 1 (KEAP1)/NF-E2-related factor 2 (NRF2) pathway, so as to defend against hepatocyte oxidative stress. These findings suggest that dietary selenium supplementation can effectively resist hepatic injury and insulin resistance during NAFLD development, and regulate the KEAP1/NRF2 pathway to resist oxidative stress by promoting SEPP1 synthesis.

Serum Inflammatory Factors and Oxidative Stress Factors Are Associated With Increased Risk of Frailty and Cognitive Frailty in Patients With Cerebral Small Vessel Disease

Objective: To study the correlation between serum inflammatory factors, oxidative stress factors and frailty, and cognitive frailty in patients with cerebral small vessel disease (CSVD).

Methods: A total of 281 patients with CSVD were selected from Tianjin Huanhu Hospital and Inner Mongolia People's Hospital from March 2019 to March 2021. CSVD was diagnosed by MRI. The FRAIL scale was used to evaluate the frailty of patients. Patients with CSVD with frailty and MMSE score <27 were considered to have cognitive frailty. Patients with non-cognitive frailty were included in the control group. The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were used to evaluate the cognitive function of patients with CSVD. The serum interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase 3 (MMP-3), superoxide dismutase (SOD), and malondialdehyde (MDA) of patients with CSVD were detected. The correlation between blood inflammatory factors and oxidative stress factors with the frailty and cognitive frailty patients of CSVD were analyzed. Univariate and multivariate logistic regression were used to analyze the correlation between cognitive frailty and CSVD.

Results: Among the patients with CSVD selected in this study, female patients and older patients had a higher proportion of frailty (p < 0.001). In the Frail group, MoCA score and MMSE score were significantly lower than in the Pre-Frail and Robust groups, Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA) scores were significantly higher than the Pre-Frail and Robust groups, and the differences were statistically significant (p < 0.05). Serum CRP, IL-6, TNF-α, MMP-3, and MDA levels in the Frail group were higher, but SOD levels were lower. The levels of serum CRP, IL-6, TNF-α, MMP-3, and MDA in patients with CSVD in the Cognitive Frailty group were significantly higher than those of the Control group, while the levels of SOD were significantly lower than those of the Control group, and the differences were significant (p < 0.001). The results of univariate and multivariate logistic regression analysis showed that CRP, TNF-α, MMP-3, and MDA levels were associated with cognitive frailty in patients with CSVD (p < 0.05).

Conclusion: The increase of serum CRP, TNF-α, MMP-3, and MDA levels are significantly related to the increased risk of frailty and cognitive frailty in patients with CSVD.

Alginate oligosaccharide alleviates D-galactose-induced cardiac ageing via regulating myocardial mitochondria function and integrity in mice

Ageing is a crucial risk factor for the development of age‐related cardiovascular diseases. Therefore, the molecular mechanisms of ageing and novel anti‐ageing interventions need to be deeply studied. Alginate oligosaccharide (AOS) possesses high pharmacological activities and beneficial effects. Our study was undertaken to investigate whether AOS could be used as an anti‐ageing drug to alleviate cardiac ageing. D‐galactose (D‐gal)‐induced C57BL/6J ageing mice were established by subcutaneous injection of D‐gal (200 mg·kg^‐1·d^‐1) for 8 weeks. AOS (50, 100 and 150 mg·kg^‐1·d^‐1) were administrated intragastrically for the last 4 weeks. As a result, AOS prevented cardiac dysfunction in D‐gal‐induced ageing mice, including partially preserved ejection fraction (EF%) and fractional shortening (FS%). AOS inhibited D‐gal‐induced up‐regulation of natriuretic peptides A (ANP), brain natriuretic peptide (BNP) and ageing markers p53 and p21 in a dose‐dependent manner. To further explore the potential mechanisms contributing to the anti‐ageing protective effect of AOS, the age‐related mitochondrial compromise was analysed. Our data indicated that AOS alleviated D‐gal‐induced cardiac ageing by improving mitochondrial biogenesis, maintaining the mitochondrial integrity and enhancing the efficient removal of impaired mitochondria. AOS also decreased the ROS production and oxidative stress status, which, in turn, further inhibiting cardiac mitochondria from being destroyed. Together, these results demonstrate that AOS may be an effective therapeutic agent to alleviate cardiac ageing.

The Immp2l Mutation Causes Ovarian Aging Through ROS-Wnt/β-Catenin-Estrogen Pathway: Preventive Effect of Melatonin

Mitochondria play important roles in ovarian follicle development. Mitochondrial dysfunction, including mitochondrial gene deficiency, impairs ovarian development. Here, we explored the role and mechanism of mitochondrial inner membrane gene Immp2l in ovarian follicle growth and development. Our results revealed that female Immp2l-/- mice were infertile, whereas Immp2l+/- mice were normal. Body and ovarian weights were reduced in the female Immp2l-/- mice, ovarian follicle growth and development were stunted in the secondary follicle stage. Although a few ovarian follicles were ovulated, the oocytes were not fertilized because of mitochondrial dysfunction. Increased oxidative stress, decreased estrogen levels, and altered genes expression of Wnt/β-catenin and steroid hormone synthesis pathways were observed in 28-day-old Immp2l-/- mice. The Immp2l mutation accelerated ovarian aging process, as no ovarian follicles were detected by age 5 months in Immp2l-/- mice. All the aforementioned changes in the Immp2l-/- mice were reversed by administration of antioxidant melatonin to the Immp2l-/- mice. Furthermore, our in vitro study using Immp2l knockdown granulosa cells confirmed that the Immp2l downregulation induced granulosa cell aging by enhancing reactive oxygen species (ROS) levels, suppressing Wnt16, increasing β-catenin, and decreasing steroid hormone synthesis gene cyp19a1 and estrogen levels, accompanied by an increase in the aging phenotype of granulosa cells. Melatonin treatment delayed granulosa cell aging progression. Taken together, Immp2l causes ovarian aging through the ROS-Wnt/β-catenin-estrogen (cyp19a1) pathway, which can be reversed by melatonin treatment.

Effects of High-Dose Selenium Supplementation on Oxidative Stress and Inflammatory Markers in Critically Ill Children After Gastrointestinal Surgery: A Randomized Clinical Trial

Background: Pediatric observational studies have indicated that most critically ill children have low serum selenium level, which is associated with the increased incidence of multiple organ failure and deteriorated clinical outcomes. Selenium plays a key role in the endogenous antioxidant defense mechanism and inflammatory pathways. Objectives: The present study aimed to assess the effects of high-dose selenium supplementation on the improvement of inflammatory and oxidative stress indices, as well as clinical outcomes, in pediatric patients with severe oxidative stress and inflammation following major gastrointestinal surgeries. Methods: This prospective, single-blind, randomized, parallel group superiority trial was conducted at the pediatric intensive care unit (PICU) of Akbar Pediatric Hospital in Mashhad, Iran in 2019. Patients were assigned to the supplementation (high-dose selenium: 20 µg/kg/d) and control groups (placebo with the recommended dietary allowance doses of selenium) using stratified blocks. Among 72 eligible critically ill children after gastrointestinal surgery, 66 patients completed the study. Inflammatory markers were measured and compared between the groups, including high-sensitivity C-reactive protein (hsCRP), interleukin 1 beta (IL-1β), prooxidant-antioxidant balance (PAB) assay, and clinical outcomes. Data analysis was performed in SPSS version 20 using the intention-to-treat approach. Results: Only 14 patients had optimal serum selenium concentrations before the surgery and PICU admission. At the end of the study, 90.6% of the patients (n = 29) in the intervention group and 100% (n = 34) of those in the placebo group had suboptimal serum selenium levels (< 50 ng/mL). Although supplementation with high-dose selenium decreased the inflammatory markers in the post-surgical critically ill children (-18 mg/mL and -37.5 pg/mL for hsCRP and IL-1β, respectively), the administered dose could not improve the serum glutathione peroxidase (GPx) concentrations as the selenium functional marker, as well as the PAB assay as the single test to assess the balance/imbalance of the oxidants and antioxidants simultaneously. Additionally, clinical outcomes such as infections, length of ICU stay, and 28-day mortality did not improve after the intervention. Conclusions: According to the results, high-dose selenium supplementation (20 µg/kg/d) in the post-surgical critically ill children could improve the serum inflammatory markers. However, the changes were suboptimal with no significant effects of the serum GPx concentrations, antioxidant defense system, and clinical outcomes.

Dynamics of plasma micronutrient concentrations and their correlation with serum proteins and thyroid hormones in patients with paracoccidioidomycosis

Minerals, such as zinc, copper, and iron are reported to play roles in chronic infectious diseases; however, their role in paracoccidioidomycosis (PCM) remains unknown. This study aimed to examine the micronutrient dynamics and their correlation with serum proteins and thyroid hormones in patients with PCM. In 14 patients with PCM and 10 healthy subjects, we evaluated the body mass index (BMI) along with serum levels of hemoglobin, iron, ferritin, zinc, copper, magnesium, albumin, globulin, thyroid stimulating hormone (TSH), thyroxine (free T4), and triiodothyronine (T3). Evaluations were conducted at the first appointment, before treatment, and at the end of the first, second, fourth, and sixth month of PCM treatment. The control group was only evaluated once. We observed that before treatment, patients with PCM, had higher levels of copper and lower level of iron than those of the control group. After one month of treatment, the iron levels increased, whereas the levels of copper after six months of treatment. Reduction in inflammatory activity, indicated by the normalization of C-reactive protein, ferritin, albumin, and globulin levels, was observed during treatment. However, no correlation was observed between the serum levels of minerals and inflammatory activity or thyroid function in this study. In conclusion, our results showed higher serum copper levels in control group compared to those in pretreatment patients; the clinical importance of this observation should be investigated in further studies. After treatment, serum copper levels showed a tendency to decrease. In addition, serum iron levels were decreased at the stage of active disease, and were increased after treatment. Thus, serum iron levels can be used as a better biomarker for treatment control.