Glutathione Induces Keap1 S-Glutathionylation and Mitigates Oscillating Glucose-Induced ß-Cell Dysfunction by Activating Nrf2.

Glutathione (GSH), a robust endogenous antioxidant, actively participates in the modulation of the redox status of cysteine residues in proteins. Previous studies have indicated that GSH can prevent ß-cell failure and prediabetes caused by chronic oscillating glucose (OsG) administration. However, the precise mechanism underlying the protective effect is not well understood. Our current research reveals that GSH is capable of reversing the reduction in Nrf2 levels, as well as downstream genes Grx1 and HO-1, in the islet ß-cells of rats induced by chronic OsG. In vitro experiments have further demonstrated that GSH can prevent ß-cell dedifferentiation, apoptosis, and impaired insulin secretion caused by OsG. Additionally, GSH facilitates the translocation of Nrf2 into the nucleus, resulting in an upregulation of Nrf2-targeted genes such as GCLC, Grx1, HO-1, and NQO1. Notably, when the Nrf2 inhibitor ML385 is employed, the effects of GSH on OsG-treated ß-cells are abrogated. Moreover, GSH enhances the S-glutathionylation of Keap1 at Cys273 and Cys288, but not Cys151, in OsG-treated ß-cells, leading to the dissociation of Nrf2 from Keap1 and facilitating Nrf2 nuclear translocation. In conclusion, the protective role of GSH against OsG-induced ß-cell failure can be partially attributed to its capacity to enhance Keap1 S-glutathionylation, thereby activating the Nrf2 signaling pathway. These findings provide novel insights into the prevention and treatment of ß-cell failure in the context of prediabetes/diabetes, highlighting the potential of GSH.

Glutathione prevents high glucose-induced pancreatic fibrosis by suppressing pancreatic stellate cell activation via the ROS/TGFß/SMAD pathway.

The activation of pancreatic stellate cells (PSCs) is the key mechanism of pancreatic fibrosis, which can lead to ß-cell failure. Oxidative stress is an important risk factor for PSC activation. There is no direct evidence proving if administration of glutathione can inhibit fibrosis and ß-cell failure. To explore the role of glutathione in pancreatic fibrosis and ß-cell failure induced by hyperglycaemia, we established a rat model of pancreatic fibrosis and ß-cell failure. The model was founded through long-term oscillating glucose (LOsG) intake and the setup of a sham group and a glutathione intervention group. In vitro, rat PSCs were treated with low glucose, high glucose, or high glucose plus glutathione to explore the mechanism of high glucose-induced PSC activation and the downstream effects of glutathione. Compared with sham rats, LOsG-treated rats had higher reactive oxygen species (ROS) levels in peripheral leukocytes and pancreatic tissue while TGFß signalling was upregulated. In addition, as the number of PSCs and pancreatic fibrosis increased, ß-cell function was significantly impaired. Glutathione evidently inhibited the upregulation of TGFß signalling and several unfavourable outcomes caused by LOsG. In vitro treatment of high glucose for 72 h resulted in higher ROS accumulation and potentiated TGFß pathway activation in PSCs. PSCs showed myofibroblast phenotype transformation with upregulation of α-SMA expression and increased cell proliferation and migration. Treatment with either glutathione or TGFß pathway inhibitors alleviated these changes. Together, our findings suggest that glutathione can inhibit PSC activation-induced pancreatic fibrosis via blocking ROS/TGFß/SMAD signalling in vivo and in vitro.

Inflammation/Coagulopathy/Immunology Responsive Index Predicts Poor COVID-19 Prognosis.

In the early stage of coronavirus disease 2019 (COVID-19), most cases are identified as mild or moderate illnesses. Approximately 20% of hospitalised patients become severe or critical at the middle or late stage of the disease. The predictors and risk factors for prognosis in those with mild or moderate disease remain to be determined. Of 694 patients with COVID-19, 231 patients with mild or moderate disease, who were hospitalised at 10 hospitals in Wenzhou and nearby counties in China, were enrolled in this retrospective study from 17 January to 20 March 2020. The outcomes of these patients included progression from mild/moderate illness to severe or critical conditions. Among the 231 patients, 49 (21.2%) had a poor prognosis in the hospital. Multivariate logistic regression analysis showed that higher inflammation/coagulopathy/immunology responsive index (ICIRI=[c-reactive protein × fibrinogen × D-dimer]/CD8 T cell count) on admission (OR=345.151, 95% CI=23.014-5176.318) was associated with increased odds ratios for poor prognosis. The area under the receiver operating characteristic curve for ICIRI predicting severe and critical condition progression was 0.65 (95% CI=0.519-0.782) and 0.80 (95% CI=0.647-0.954), with cut-off values of 870.83 and 535.44, respectively. Conversely, age, sex, comorbidity, neutrophil/lymphocyte ratio, CD8 T cell count, and c-reactive protein, fibrinogen, and D-dimer levels alone at admission were not good predictors of poor prognosis in patients with mild or moderate COVID-19. At admission, a novel index, ICIRI, tends to be the most promising predictor of COVID-19 progression from mild or moderate illness to severe or critical conditions.

Inflammation/coagulopathy/fibrinolysis: Dynamic indicators of COVID-19 progression in patients with moderate COVID-19 in Wenzhou, China.

BACKGROUND: The majority of the coronavirus disease 2019 (COVID-19) non-survivors meet the criteria for disseminated intravascular coagulation (DIC). Although timely monitoring of clotting hemorrhagic development during the natural course of COVID-19 is critical for understanding pathogenesis, diagnosis, and treatment of the disease, however, limited data are available on the dynamic processes of inflammation/coagulopathy/fibrinolysis (ICF). METHODS: We monitored the dynamic progression of ICF in patients with moderate COVID-19. Out of 694 COVID-19 inpatients from 10 hospitals in Wenzhou, China, we selected 293 adult patients without comorbidities. These patients were divided into different daily cohorts according to the COVID-19 onset-time. Furthermore, data of 223 COVID-19 patients with comorbidities and 22 critical cases were analyzed. Retrospective data were extracted from electronic medical records. RESULTS: The virus-induced damages to pre-hospitalization patients triggered two ICF fluctuations during the 14-day course of the disease. C-reactive protein (CRP), fibrinogen, and D-dimer levels increased and peaked at day 5 (D) 5 and D9 during the 1st and 2nd fluctuations, respectively. The ICF activities were higher during the 2nd fluctuation. Although 12-day medication returned high CRP concentrations to normal and blocked fibrinogen increase, the D-dimer levels remained high on days 17 ±â€¯2 and 23 ±â€¯2 days of the COVID-19 course. Notably, although the oxygenation index, prothrombin time and activated partial thromboplastin time were within the normal range in critical COVID-19 patients at administration, 86% of these patients had a D-dimer level > 500 µg/L. CONCLUSION: COVID-19 is linked with chronic DIC, which could be responsible for the progression of the disease. Understanding and monitoring ICF progression during COVID-19 can help clinicians in identifying the stage of the disease quickly and accurately and administering suitable treatment.

Retraction: Size-selected silver nanoparticles for MALDI-TOF mass spectrometry of amyloid-beta peptides.

Retraction of 'Size-selected silver nanoparticles for MALDI-TOF mass spectrometry of amyloid-beta peptides' by Feng Ding et al., Nanoscale, 2018, 10, 22044-22054, DOI: 10.1039/C8NR07921H.

Glutathione prevents chronic oscillating glucose intake-induced ß-cell dedifferentiation and failure.

Modern lifestyles have altered diet and metabolic homeostasis, with increased sugar intake, glycemic index, and prediabetes. A strong positive correlation between sugar consumption and diabetic incidence is revealed, but the underlying mechanisms remain obscure. Here we show that oral intake of long-term oscillating glucose (LOsG) (4 times/day) for 38 days, which produces physiological glycemic variability in rats, can lead to ß-cells gaining metabolic memory in reactive oxygen species (ROS) stress. This stress leads to suppression of forkhead box O1 (FoxO1) signaling and subsequent upregulation of thioredoxin interacting protein, inhibition of insulin and SOD-2 expression, re-expression of Neurog3, and ß-cell dedifferentiation and functional failure. LOsG-treated animals develop prediabetes exhibiting hypoinsulinemia and glucose intolerance. Dynamic and timely administration of antioxidant glutathione prevents LOsG/ROS-induced ß-cell failure and prediabetes. We propose that ROS stress is the initial step in LOsG-inducing prediabetes. Manipulating glutathione-related pathways may offer novel options for preventing the occurrence and development of diabetes.

Size-selected silver nanoparticles for MALDI-TOF mass spectrometry of amyloid-beta peptides.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is one of the most efficient mass spectrometric techniques for the analysis of high-molecular-weight compounds with superior selectivity and sensitivity. Common MALDI matrices are low molecular weight (LMW) organics and will therefore produce a large amount of matrix-related ion peaks, which limits the use of MALDI-MS for the detection of LMW molecules. A major breakthrough of this limitation was made by the introduction of surface assisted desorption/ionization techniques, with graphite particles firstly as the matrix, followed by expansion into other types of nanoparticles or nanostructures. However, previous studies failed to address well the optimum size and concentration of Ag NPs to be used as the MALDI matrix. In this study, to explore and compare the efficiency of different sized silver nanoparticles (Ag NPs) as the MALDI matrix for the detection of LMW molecules, three different sized Ag NPs (2.8 ± 1.0, 12.8 ± 3.2 and 44.2 ± 5.0 nm) have been successfully developed as the MALDI time-of-flight MS (MALDI-TOF MS) matrix and amyloid-beta (Aß) peptides, crucially involved in Alzheimer's disease and a variety of cancers, were chosen as an example of LMW molecules in our MALDI-TOF MS analysis with Ag NPs as matrices. The results showed size-selected MS signals with the smallest (2.8 ± 1.0 nm) Ag NP matrix producing the highest spectral intensities, when compared with other larger sized Ag NP matrices and conventional matrices such as SA and DHB. Furthermore, the optimal concentrations for different sized Ag NPs as matrices were determined as follows: 0.125 nM (2.8 ± 1.0 nm Ag NPs), 0.0625 nM (12.8 ± 3.2 nm Ag NPs), and 0.03125 nM (44.2 ± 5.0 nm Ag NPs), respectively. These results not only corroborated that Ag NPs could act as a very suitable matrix to assist in the desorption/ionization of LMW molecules but also revealed size-selected mass spectrometry signals with smaller Ag NPs as the MALDI matrix bearing more advantages than their larger counterparts. These novel findings paved the way for wider applications of MALDI-MS using Ag NPs as matrices for the analysis of LMW molecules.

Chronic oscillating glucose challenges disarrange innate immune homeostasis to potentiate the variation of neutrophil-lymphocyte ratio in rats with or without hidden diabetes mellitus.

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) has been considered as an inflammatory marker in various disorders, but it is not clear whether the NLR is also elevated with hidden diabetes (HD), which is normal in fasting blood glucose (FBG) but abnormal in the oral glucose tolerance test (OGTT). MATERIALS AND METHODS: An HD animal model for 27 days and an animal model with oscillating glucose (OG) for 7 days were applied on adult female Sprague-Dawley rats. OGTT, leukogram analysis, histology, and immunohistochemistry were carried out. RESULTS: In HD rats, the percentage of neutrophils increased but the percentage of lymphocytes decreased; hence, the NLR rose relative to sham. This may be a result of the OG levels often experienced by diabetic subjects, as normal rats given OG (6 g/kg/6 h) for 7 days had significantly reduced lymphocyte numbers and increased NLR compared with the values before and 1 h after oral glucose administration during OGTT. Glucose-induced disarrangement of partitions of circulating immune cells and NLR was involved in the increase in oxidative stress, as these changes were totally blocked by the antioxidant glutathione (GSH). GSH (50 mg/kg/6 h) totally blocked the glucose-induced alterations in lymphocyte and NLR values. CONCLUSION: HD associated with elevation of NLR values may be partly attributed to a homeostasis disorder of the innate inflammatory state, caused by oscillating hyperglycemia. Acute high glucose administration produced a significant decrease in lymphocyte number. OG administration potentiated this effect and increased the NLR value, which was blocked by GSH, suggesting that reactive oxygen species play a critical role in maintaining lymphocyte numbers.

Role of miRNA in Lung Cancer-Potential Biomarkers and Therapies.

MicroRNAs (miRNAs) are small noncoding RNAs, which downregulate gene expression by repressing or degrading mRNA targets. Lung cancer (LC), together with liver and colorectal cancers are the three leading causes of cancer death worldwide, and 80% of LCs belong to non-small cell lung cancers (NSCLCs). Despite a great advancement in developing distinct and delicate tools for early diagnosis and targeted therapies over the last decade, only about 15% of the NSCLC patients eventually survived. MiRNAs are frequently dysregulated in carcinoma, including LC. Numerous lines of evidence have demonstrated various roles played by miRNAs in the development and progression of LC. In this review, we propose to summarize the current understanding of miRNAs in LC, with a particular focus on translational application of miRNAs as novel diagnostic and prognostic biomarkers and tools for treatment.

Microarray Analysis of Differential Gene Expression Profile Between Human Fetal and Adult Heart.

Although many changes have been discovered during heart maturation, the genetic mechanisms involved in the changes between immature and mature myocardium have only been partially elucidated. Here, gene expression profile changed between the human fetal and adult heart was characterized. A human microarray was applied to define the gene expression signatures of the fetal (13-17 weeks of gestation, n = 4) and adult hearts (30-40 years old, n = 4). Gene ontology analyses, pathway analyses, gene set enrichment analyses, and signal transduction network were performed to predict the function of the differentially expressed genes. Ten mRNAs were confirmed by quantificational real-time polymerase chain reaction. 5547 mRNAs were found to be significantly differentially expressed. "Cell cycle" was the most enriched pathway in the down-regulated genes. EFGR, IGF1R, and ITGB1 play a central role in the regulation of heart development. EGFR, IGF1R, and FGFR2 were the core genes regulating cardiac cell proliferation. The quantificational real-time polymerase chain reaction results were concordant with the microarray data. Our data identified the transcriptional regulation of heart development in the second trimester and the potential regulators that play a prominent role in the regulation of heart development and cardiac cells proliferation.

Decreased miR-143 and increased miR-21 placental expression levels are associated with macrosomia.

Macrosomia, a birth weight ≥ 4,000 g, is associated with maternal and infant health problems. The dysregulation of microRNAs (miRNAs) in the placenta is associated with adverse birth outcomes, yet whether aberrantly expressed placental miRNAs are associated with macrosomia remains unknown. The aim of the current study was to characterize the expression of three placental miRNAs (miR­6, ­21 and ­143) and evaluate their association with macrosomia. The miRNA expression in placental tissues from 67 macrosomic pregnancies and 64 normal pregnancies were analyzed using reverse transcription­quantitative polymerase chain reaction. The expression of miR­21 was observed to be elevated in macrosomic placenta compared with control samples, while miR­143 expression was significantly lower than in control placenta (P<0.05). No significant differences were identified in the miR­16 expression levels between the groups (P=0.955). Following division of miRNA expression levels by quartile, logistic regression models demonstrated that the odds of macrosomia increased with miR­21 expression quartile: Q2, odds ratio (OR)=6.67 [95% confidence interval (CI), 1.39­32.05]; Q3, OR=4.10 (95% CI, 0.88­19.11); Q4, OR=16.19 (95% CI, 2.46­106.68). Conversely, higher levels of miR­143 expression were protective against macrosomia: Q2, OR=0.22 (95% CI, 0.049­0.98); Q3, OR=0.11 (95% CI, 0.024­0.55), and Q4, OR=0.16 (95% CI, 0.032­0.79). Thus, statistical analysis demonstrated that high levels of miR­21 expression and low levels of miR­143 expression predict the risk for macrosomia, indicating an interaction between the two miRNAs. Bioinformatic analysis suggested that they are likely to function in the mitogen­activated protein kinases signaling pathway to influence the risk of macrosomia. The results of the present study provide evidence that placental miR-21 and -143 are important in the formation of macrosomia.

Birth weight is associated with placental fat mass- and obesity-associated gene expression and promoter methylation in a Chinese population.

OBJECTIVE: To explore the relationship between birth weight and fat mass- and obesity-associated (FTO) gene expression and promoter methylation status in the Chinese population. METHODS: Seventy-five neonates and their mothers were recruited from Yuying Children's Hospital of Wenzhou Medical University. Subjects were divided into three groups by birth weight: low (< 3,500 g, n = 20), medium (3,500-3,999 g, n = 30) and high (≥ 4,000 g, n = 25). Placental FTO transcript levels and promoter methylation were determined by quantitative PCR and Sequenom MassARRAY®. RESULTS: Placental FTO mRNA expression was significantly increased in the high- and medium-weight groups compared to the low-weight group (p = 0.023). Methylation rates of CpG11 sites were significantly decreased in high-birth weight newborns (p = 0.018). Multiple linear regressions showed placental FTO mRNA, maternal pre-pregnancy body mass index (BMI) and CpG11 methylation rate were independently associated with increased fetal birth weight. Additionally, FTO mRNA expression was negatively associated with CpG6.7.8.9 methylation in mothers that underwent C-section. CONCLUSIONS: High placental FTO expression is associated with increased birth weight in Chinese neonates, and FTO promoter methylation level at a specific CpG site is negatively associated with birth weight. Further work is needed to determine the functionality of this CpG site in placentas.

[Correlation of insulin-like growth factor 1 expression in placenta with DNA methylation and fetal macrosomia].

OBJECTIVE: To explore the correlation between methylation of insulin-like growth factor 1 (IGF-1) gene promoter and its placenta-specific expression and fetal macrosoma. METHODS: One hundred twenty nine healthy pregnant women were recruited between April 2011 and March 2012. Baseline data were collected with self-report questionnaires. Real-time quantitative PCR was used to determine the expression of IGF-1 mRNA in the placenta. Methylation level of the IGF 1 gene was determined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry. RESULTS: The expression of IGF-1 in placenta and its methylation level showed no significant difference between macrosomic fetuses and controls. No linear correlation was found between IGF-1 mRNA expression and methylation level of IGF-1 promoter (r=0.128, P=0.295). IGF-1 promoter region in placenta showed a hypomethylation status. However, a positive correlation was found between IGF-1 expression and birth weight below 4260 g (r=0.264, P=0.022). The expression of IGF-1 mRNA was significantly higher in those with a birth weight below 4260 g, which suggested that placental IGF-1 expression may contribute to increased birth weight. In regard to fetal overgrowth, however, there seemed to be a negative correlation in which placental IGF-1 expression was downregulated to limit fetal overgrowth. CONCLUSION: No linear correlation was found between placental IGF-1 expression and methylation level of IGF-1 promoter with a hypomethylation status. The contribution of placental IGF-1 expression to birth weight is bidirectional. Increased expression seems to promote fetal growth, while decreased expressions may curb overgrowth, therefore control fetal growth in a relatively normal range.