Oxidative stress-mediated beta cell death and dysfunction as a target for diabetes management

Downregulation of Glis3 in INS1 cells exposed to chronically elevated glucose contributes to glucotoxicity-associated β cell dysfunction

Chronically elevated levels of glucose are deleterious to pancreatic β cells and contribute to β cell dysfunction, which is characterized by decreased insulin production and a loss of β cell identity. The Krüppel-like transcription factor, Glis3 has previously been shown to positively regulate insulin transcription and mutations within the Glis3 locus have been associated with the development of several pathologies including type 2 diabetes mellitus. In this report, we show that Glis3 is significantly downregulated at the transcriptional level in INS1 832/13 cells within hours of being subjected to high glucose concentrations and that diminished expression of Glis3 is at least partly attributable to increased oxidative stress. CRISPR/Cas9-mediated knockdown of Glis3 indicated that the transcription factor was required to maintain normal levels of both insulin and MafA expression and reduced Glis3 expression was concomitant with an upregulation of β cell disallowed genes. We provide evidence that Glis3 acts similarly to a pioneer factor at the insulin promoter where it permissively remodels the chromatin to allow access to a transcriptional regulatory complex including Pdx1 and MafA. Finally, evidence is presented that Glis3 can positively regulate MafA transcription through its pancreas-specific promoter and that MafA reciprocally regulates Glis3 expression. Collectively, these results suggest that decreased Glis3 expression in β cells exposed to chronic hyperglycemia may contribute significantly to reduced insulin transcription and a loss of β cell identity.

Tangningtongluo Tablet ameliorates pancreatic damage in diabetic mice by inducing autophagy and inhibiting the PI3K/Akt/mTOR signaling pathway

BACKGROUND

Diabetes is a metabolic disease characterized by hyperglycaemia. Tangningtongluo Tablet (TNTL) is an inpatient formula extensively utilized to treat diabetes mellitus (DM), but the protective mechanism is not clear. This study aimed to investigate the relevant mechanisms by which TNTL affects pancreatic damage in diabetic mice and autophagy.

METHODS

The impact of TNTL on pancreatic damage in diabetic mice in vitro and in vivo was investigated via glucose and lipid metabolism analyses, HE staining, CCK-8, TUNEL staining, Annexin V/PI, and Western blotting. Molecular docking and Western blotting were used to verify the results of network pharmacological analysis, which was carried out to explore the mechanism by which TNTL affects DM. The autophagosome levels were visualized via RFP-GFP-LC3 and transmission electron microscopy, and lysosomal function was evaluated via Lysotracker red staining. Western blot, immunohistochemistry and immunofluorescence staining were used to detect the expression of the autophagy proteins LC3, p62 and LAMP2.

RESULTS

Compared with the model group, TNTL protected pancreas from oxidative stress, decreased the level of MDA, increased the levels of SOD and GSH-px, induced the occurrence of autophagy and decreased the levels of apoptotic factors. Moreover, TNTL inhibited the protein expression of p-PI3K, p-Akt and p-mTOR, increased the levels of LC3 and LAMP2 and decreased the level of p62, and the autophagy inhibitor CQ blocked the protective effect of TNTL on pancreatic damage in diabetic mice.

CONCLUSION

These results demonstrated that TNTL ameliorated pancreatic damage in diabetic mice by inhibiting the PI3K/Akt/mTOR signaling and regulating autophagy.

Nitration of Tyr37 alters the aggregation pathway of hIAPP and enhances its cytotoxicity

The amyloid aggregation of hIAPP and the increased level of oxidative stress are closely related to the occurrence and development of type 2 diabetes (T2D). Protein tyrosine nitration is a common post-translational modification under oxidative stress conditions. We previously found that tyrosine nitrated hIAPP (3-NT-hIAPP) has higher cytotoxicity than wild type hIAPP. In order to further elucidate the mechanism by which tyrosine nitration enhances the toxicity of hIAPP, we systematically studied the effect of tyrosine nitration on hIAPP aggregation and its impact on INS-1 cells. Collective experimental data from ThT, RLS, DLS, zeta potentials, Bis-ANS, 1H NMR, TEM, dye leakage and hemolysis confirmed that tyrosine nitration accelerates hIAPP aggregation, consistent with tyrosine nitration reducing hIAPP zeta potential, but 3-NT-hIAPP mainly undergoes an off-pathway aggregation to form amorphous aggregates, even in the presence of POPC/POPG LUVs. Further, our results confirmed that the most toxic species are the small amorphous aggregates formed by 3-NT-hIAPP, which is more stable and toxic than hIAPP oligomers. Collectively, these data suggest that tyrosine nitration can increase cytotoxicity of hIAPP by modulating its amyloidogenicity. This study provides new support for the fact that oxidative stress promotes the development of T2D from the view of nitrative stress.

Theoretical investigations of some isolated compounds from Calophyllum flavoramulum as potential antioxidant agents and inhibitors of AGEs

In this paper, we have attempted a theoretical calculation of some plant-isolated compounds as potential inhibitors of oxidative stress and Advanced Glycation Endproducts (AGEs). Herein, theoretical reactivity indices based on the CDFT theory were computed to explore the reactivity of five isolated products from Calophyllum flavoramulum. Global reactivity indices based on HOMO and LUMO energy such as electronic chemical potential, hardness, electrophilicity and the local reactivity descriptors Parr function, molecular electrostatic potentials(MEP), electrostatic potential (ESP) and thermodynamic parameters for the studied compounds are computed and discussed using DFT method and two functionals B3LYP and CAM-B3LYP with 6-31 G(d,p) basis set. The free radical scavenging activity mechanisms (HAT, SET-PT, and SPLET) of some of the isolated products with DPPH are also presented in this work. SET-PT mechanism of the antiradical activity is found to be thermodynamically favorable. Furthermore, a molecular docking study with RAGE receptor and AtGSTF2 enzyme was conducted, in which flavonoids 4 and 5 show a low binding affinity with -8.42 and -10.49 kcal/mol for RAGE, -8.67 and -9.00 kcal/mol for AtGSTF2. After the encouraging outcomes from the molecular docking study, the 4-AtGSTF2 and 5-RAGE complex were subjected to 200 ns molecular dynamics simulation using Desmond, where both studied systems exhibited remarkable stability throughout the 200 ns simulations. Also, the MM-GBSA method was measured by calculating the binding free energy using the individual energy components. Finally, the ADMET predictions were assessed to anticipate the behavior of a drug candidate within the human body.

Effects of exogenous ghrelin treatment on oxidative stress, inflammation and histological parameters in a fat-fed streptozotocin rat model

In this study, the anti-inflammatory, antioxidative, and protective effects of ghrelin were investigated in a fat-fed streptozotocin (STZ) rat model and compared with metformin, diabetes and the healthy control groups. Histopathological evaluations were performed on H&E-stained pancreas and brain sections. Biochemical parameters were investigated by enzyme-linked immunosorbent assay. Blood glucose levels were significantly decreased with ghrelin or metformin treatments than the diabetes group. STZ administration increased brain, renal and pancreatic IL-1β, TNF-α and MDA while decreasing GPX, CAT, SOD, and NGF levels. Ghrelin increased renal GPX, CAT, NGF pancreatic GPX, SOD, CAT, NGF and brain SOD, NGF while it decreased renal, pancreatic and brain IL-1β, TNF-α and MDA levels. Ghrelin reduced neuronal loss and degeneration in the cerebral cortex and hippocampus and greatly ameliorated diabetes-related damage in pancreas. In conclusion, the data suggested that ghrelin is an effective candidate as a protectant for reducing the adverse effects of diabetes.

Hallmarks of diabetes mellitus and insights into the therapeutic potential of synergy-based combinations of phytochemicals in reducing oxidative stress-induced diabetic complications

Diabetes mellitus (DM) is a serious health issue and is still one of the major causes of mortality around the globe. Natural products have progressively integrated into modern, advanced medical practices. Phytoconstituents from some medicinal plants have demonstrated therapeutic activity in treating different metabolic disorders and have been used to treat DM and its severe complications. The present review provides details of the major anti-diabetic targets identified in the literature and also provides comprehensive information regarding the therapeutic role of a synergy-based combination of phytoconstituents that functions by controlling specific molecular pathways synchronously by inhibiting certain key regulators involved in the development and progression of DM. The review also implicated the role of oxidative stress in diabetic complications and presented scientific validations of phytochemicals and their synergy-based combination using in vitro and or in vivo approaches.

Evaluation of folliculogenesis and oxidative stress parameters in type 1 diabetes mellitus women with different glycemic profiles

BACKGROUND

Despite enormous advances in diabetes treatment, women with type 1 diabetes mellitus (DM) still experience delayed menarche, menstrual irregularities, fewer pregnancies, and a higher rate of stillbirths compared to women without the disease. Due to the fact that type 1 DM occurs at a young age, the preservation of reproductive health is one of the most important goals of treatment.

AIMS

The aim of this study was to evaluate the relationship between different glycemic profiles and changes in the pro-oxidant-antioxidant balance and ovarian follicular apparatus in reproductive-age patients with type 1 DM.

METHODS

We examined 50 reproductive-age (19-38 years) women with type 1 DM with a disease duration of at least ten years. Carbohydrate metabolism was assessed with the continuous glucose monitoring (CGM) system and glycated hemoglobin (HbA1c) concentration measurement. CGM was performed using the FreeStyle Libre flash glucose monitoring system (Abbott Diabetes Care, Witney, UK). In each patient, malondialdehyde level, catalase activity and 3-nitrotyrosine level in the blood serum were determined. To assess the ovarian function, we measured the ovarian volume, the antral follicle count, and the serum levels of anti-Müllerian hormone and follicle-stimulating hormone. All patients were divided into four groups (glucotypes) based on the CGM results. Group 1 included type 1 DM patients with satisfactory compensation of carbohydrate metabolism; group 2 consisted of patients with frequent hypoglycemic conditions and pathological glucose variability; group 3 included individuals with prolonged hyperglycemic conditions and maximum HbA1c levels; and group 4 comprised patients with the glycemic profile characterized by all the presented types of dysglycemia (intermittent glycemia).

RESULTS

We revealed a negative correlation between serum catalase activity and time of hypoglycemic conditions in patients with type 1 DM based on the CGM results (rs = -0.47, p < 0.01). In group 4 (intermittent glycemia), patients demonstrated the lowest serum catalase activity and increased serum 3-nitrotyrosine level, while in group 3, women with chronic hyperglycemia (HbA1c 8.4 [8.1; 9.9]%; 68 [65; 85] mmol/mol) had a moderate change in antioxidant defense and oxidative stress parameters. Correlation analysis of ovarian volume, the antral follicle count, and the serum anti-Müllerian hormone level in type 1 DM women with different glycemic profiles established a negative relationship (rs = -0.82, p < 0.05) between the antral follicle count and glucose variability in group 1, a positive relationship (rs = 0.68, p < 0.05) between ovarian volume and glucose variability in group 2, and a positive relationship (rs = 0.88, p < 0.05) between ovarian volume and time of hypoglycemic conditions, which, according to the CGM results, amounted to a critical value of 57.5 [40.0; 82.0]%.

CONCLUSIONS

The data obtained indicate the relationship between the ovarian volume, serum anti-Müllerian hormone level, the antral follicle count and oxidative stress parameters not only in patients with hyperglycemia, but also in those with hypoglycemic conditions, as well as with pathological glucose variability.

Advancing the understanding of diabetic encephalopathy through unravelling pathogenesis and exploring future treatment perspectives

Diabetic encephalopathy (DE), a significant micro-complication of diabetes, manifests as neurochemical, structural, behavioral, and cognitive alterations. This condition is especially dangerous for the elderly because aging raises the risk of neurodegenerative disorders and cognitive impairment, both of which can be made worse by diabetes. Despite its severity, diagnosis of this disease is challenging, and there is a paucity of information on its pathogenesis. The pivotal roles of various cellular pathways, activated or influenced by hyperglycemia, insulin sensitivity, amyloid accumulation, tau hyperphosphorylation, brain vasculopathy, neuroinflammation, and oxidative stress, are widely recognized for contributing to the potential causes of diabetic encephalopathy. We also reviewed current pharmacological strategies for DE encompassing a comprehensive approach targeting metabolic dysregulations and neurological manifestations. Antioxidant-based therapies hold promise in mitigating oxidative stress-induced neuronal damage, while anti-diabetic drugs offer neuroprotective effects through diverse mechanisms, including modulation of insulin signaling pathways and neuroinflammation. Additionally, tissue engineering and nanomedicine-based approaches present innovative strategies for targeted drug delivery and regenerative therapies for DE. Despite significant progress, challenges remain in translating these therapeutic interventions into clinical practice, including long-term safety, scalability, and regulatory approval. Further research is warranted to optimize these approaches and address remaining gaps in the management of DE and associated neurodegenerative disorders.

Crucial Interactions between Altered Plasma Trace Elements and Fatty Acids Unbalance Ratio to Management of Systemic Arterial Hypertension in Diabetic Patients: Focus on Endothelial Dysfunction

The coexistence of SAH with T2DM is a common comorbidity. In this study, we investigated the link between altered plasma antioxidant trace elements (ATE: manganese, selenium, zinc, and copper) and fatty acids ratio (FAR: polyunsaturated/saturated) imbalance as transition biomarkers between vascular pathology (SAH) to metabolic pathology (T2DM). Our data revealed strong correlation between plasma ATE and FAR profile, which is modified during SAH-T2DM association compared to the healthy group. This relationship is mediated by lipotoxicity (simultaneously prominent visceral adipose tissue lipolysis, significant flow of non-esterified free fatty acids release, TG-Chol-dyslipidemia, high association of total SFA, palmitic acid, arachidonic acid, and PUFA ω6/PUFA ω3; drop in tandem of PUFA/SFA and EPA + DHA); oxidative stress (lipid peroxidation confirmed by TAS depletion and MDA rise, concurrent drop of Zn/Cu-SOD, GPx, GSH, Se, Zn, Se/Mn, Zn/Cu; concomitant enhancement of Cu, Mn, and Fe); endothelial dysfunction (endotheline-1 increase); athero-thrombogenesis risk (concomitant rise of ApoB100/ApoA1, Ox-LDL, tHcy, and Lp(a)), and inflammation (higher of Hs-CRP, fibrinogen and ferritin). Our study opens to new therapeutic targets and to better dietary management, such as to establishing dietary ATE and PUFA ω6/PUFA ω3 or PUFA/SFA reference values for atherosclerotic risk prevention in hypertensive/diabetic patients.

Therapeutic effect of oral insulin-chitosan nanobeads pectin-dextrin shell on streptozotocin-diabetic male albino rats

The current study inspects the therapeutic effects of orally ingested insulin-loaded chitosan nanobeads (INS-CsNBs) with a pectin-dextrin (PD) coating on streptozotocin (STZ)-induced diabetes in Wistar rats. The study also assessed antioxidant effects in pancreatic tissue homogenate, insulin, C-peptide, and inflammatory markers interleukin-1 beta and interleukin-6 (IL-1β and IL-6) in serum. Additionally, histopathological and immunohistochemical examination of insulin granules, oxidative stress, nuclear factor kappa B (NF-κB P65), and sirtuin-1 (SIRT-1) protein detection, as well as gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl2), and Bcl-2-associated X protein (Bax) in pancreatic tissue were investigated. After induction of diabetes with STZ, rats were allocated into 6 groups: the normal control (C), the diabetic control (D), and the diabetic groups treated with INS-CsNBs coated with PD shell (50 IU/kg) (NF), free oral insulin (10 IU/kg) (FO), CsNBs-PD shell (50 IU/kg) (NB), and subcutaneous insulin (10 IU/kg) (Sc). The rats were treated daily for four weeks. Treatment of diabetic rats with INS-CsNBs coated with PD shell resulted in a significant improvement in blood glucose levels, elevated antioxidant activities, decreased NF-κB P65, IL-1β, and IL-6 levels, upregulated Nrf-2 and HO-1, in addition to a marked improvement in the histological architecture and integrity compared to the diabetic group. The effects of oral INS-CsNBs administration were comparable to those of subcutaneous insulin. In conclusion, oral administration of INS-loaded Cs-NBs with a pectin-dextrin shell demonstrated an ameliorative effect on STZ-induced diabetes, avoiding the drawbacks of subcutaneous insulin.

Liposome Encapsulation Enhances the Antidiabetic Efficacy of Silibinin

Silibinin has considerable therapeutic potential for the treatment of diabetes through anti-inflammatory, antioxidant, and immunomodulatory properties. However, the therapeutic application of silibinin is quite limited due to its poor bioavailability. In the present study, an attempt was made to improve the antidiabetic efficacy of silibinin by its encapsulation in liposomal vesicles. The liposomes with a high encapsulation efficiency of silibinin (96%) and a zeta potential of -26.2 ± 0.6 mV were developed and studied using nicotinamide/streptozotocin-induced diabetic rats. Administration of silibinin-loaded liposomes to diabetic rats lowered glucose levels, increased insulin levels, and improved pancreatic islet architecture. The anti-inflammatory effect of silibinin-loaded liposomes was demonstrated by a decrease in serum C-reactive protein (CRP) levels and a reduced deposition of collagen fibers in the islets of diabetic rats. Furthermore, silibinin-loaded liposomes were more efficient in lowering glucose, alanine transaminase, triglyceride, and creatinine levels in diabetic rats than pure silibinin. In addition, silibinin-loaded liposomes had a significantly better effect on beta-cell mass and Glut2 glucose receptor distribution in diabetic islets than pure silibinin. The present results clearly show that liposome encapsulation of silibinin enhances its antidiabetic efficacy, which may contribute to the therapeutic benefit of silibinin in the treatment of diabetes and its complications.

The antiglycation potential of H1 receptor antagonists - in vitro studies in bovine serum albumin model and in silico molecular docking analyses

The H1 receptor belongs to the family of rhodopsin-like G-protein-coupled receptors activated by the biogenic amine histamine. H1 receptor antagonists are widely used in the treatment of allergies. However, these drugs could have a much broader spectrum of activity, including hypoglycemic effects, which can broaden the spectrum of their use. The aim of the study was to evaluate the antiglycation potential of twelve H1 receptor antagonists (diphenhydramine, antazoline, promethazine, ketotifen, clemastine, pheniramine, cetirizine, levocetirizine, bilastine, fexofenadine, desloratadine, and loratadine). Bovine serum albumin (BSA) was glycated with sugars (glucose, fructose, galactose, and ribose) and aldehydes (glyoxal and methylglyoxal) in the presence of H1 blockers. The tested substances did not induce a significant decrease in the content of albumin glycation end-products, and the inhibition rate of glycoxidation was not influenced by the chemical structure or generation of H1 blockers. None of the tested H1 receptor antagonists exhibited strong antiglycation activity. Antiglycemic potential of H1 blockers could be attributed to their antioxidant and anti-inflammatory activity, as well as their effects on carbohydrate metabolism/metabolic balance at the systemic level.

Changes of RNA m6A/m5C Modification Regulatory Molecules in Ferroptosis of T2DM Rat Pancreas

N6-methyladenine (m6A) and 5-methylcytosine (m5C) are two common forms of RNA methylation that play an important role in the epigenetics of type 2 diabetes mellitus (T2DM). One type of cell death, ferroptosis, has been implicated in islet β-cell damage in T2DM. Notably, RNA methylation, an upstream regulatory mechanism of mRNAs, can regulate the expression of ferroptosis signaling molecules, thereby affecting cell proliferation and death. Here, we found that the ferroptosis signaling pathway was activated in pancreas of T2DM rats, followed by significant changes in m6A/m5C modification regulatory molecules. These detection data together with the prediction results that m6A and m5C exist in the mRNAs of ferroptosis molecules, we speculate that m6A and m5C are probably involved in pancreatic cell damage by modifying of ferroptosis signaling molecules. In short, our findings provide a new research idea for future studies on the molecular mechanisms of pancreatic cell damage and point to a new direction for exploring the mechanisms of ferroptosis from the perspective of RNA methylation modification.

Exploring Anthracycline-Induced Cardiotoxicity from the Perspective of Protein Quality Control

Anthracyclines are effective anticancer drugs; however, their use is restricted because of their dose-dependent, time-dependent and irreversible myocardial toxicity. The mechanism of anthracycline cardiotoxicity has been widely studied but remains unclear. Protein quality control is crucial to the stability of the intracellular environment and, ultimately, to the heart because cardiomyocytes are terminally differentiated. Two evolutionarily conserved mechanisms, autophagy, and the ubiquitin-proteasome system, synergistically degrade misfolded proteins and remove defective organelles. Recent studies demonstrated the importance of these mechanisms. Further studies will reveal the detailed metabolic pathway and metabolic control of the protein quality control mechanism integrated into anthracycline-induced cardiotoxicity. This review provides theoretical support for clinicians in the application and management of anthracyclines.

Silibinin as a promising treatment for diabetes: Insights into behavioral and metabolic changes in an animal model

Diabetes mellitus is causing serious health problems in the chronic period. Silibinin is a flavonoid obtained from the milk thistle (Silybum marianum), which is among the herbal ethnopharmacological administrations. In studies with silibinin, it has been reported that it increases the activity of pancreatic beta cells and insulin sensitivity and has a hyperglycemia-reducing effect. However, behavioral parameters have not been evaluated together with insulin levels and liver function tests. Our aim in this study was to examine the effects of silibinin on insulin secretion, anxiety-like behaviors, and learning in a streptozotocin (STZ)-induced rat diabetes model. Wistar albino rats weighing 200-250 g were divided into 4 groups. Control: Saline solution, Diabetes: STZ 45 mg/kg, S 100: STZ 45 mg/kg + Silibinin 100 mg/kg, S 200: STZ 45 mg/kg + Silibinin 200 mg/kg. Administrations were continued for 21 days. On the 21st day, open field and elevated plus maze as unconditional anxiety tests; Barnes maze for learning and memory; and rotarod test for locomotor activity were conducted. Following behavioral tests, blood samples were taken under anesthesia. Blood glucose levels and ALT values were measured. Insulin levels were measured with an ELISA plate reader. Silibinin shortened the time to find the correct hole. Silibinin prevented the decrease in insulin due to STZ, exhibited a hyperglycemia-reducing effect and decreased the elevation of ALT.

Pancreatic Crosstalk in the Disease Setting: Understanding the Impact of Exocrine Disease on Endocrine Function

The exocrine and endocrine are functionally distinct compartments of the pancreas that have traditionally been studied as separate entities. However, studies of embryonic development, adult physiology, and disease pathogenesis suggest there may be critical communication between exocrine and endocrine cells. In fact, the incidence of the endocrine disease diabetes secondary to exocrine disease/dysfunction ranges from 25% to 80%, depending on the type and severity of the exocrine pathology. Therefore, it is necessary to investigate how exocrine-endocrine "crosstalk" may impact pancreatic function. In this article, we discuss common exocrine diseases, including cystic fibrosis, acute, hereditary, and chronic pancreatitis, and the impact of these exocrine diseases on endocrine function. Additionally, we review how obesity and fatty pancreas influence exocrine function and the impact on cellular communication between the exocrine and endocrine compartments. Interestingly, in all pathologies, there is evidence that signals from the exocrine disease contribute to endocrine dysfunction and the progression to diabetes. Continued research efforts to identify the mechanisms that underlie the crosstalk between various cell types in the pancreas are critical to understanding normal pancreatic physiology as well as disease states. © 2024 American Physiological Society. Compr Physiol 14:5371-5387, 2024.

Novel lipid mediator 7S,14R-docosahexaenoic acid: biogenesis and harnessing mesenchymal stem cells to ameliorate diabetic mellitus and retinal pericyte loss

Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by improved glucose tolerance and higher blood insulin levels. 7S,14R-diHDHA-treated MSCs increased insulin+ β-cell ratio and decreased glucogan+ α-cell ratio in islets, as well as reduced macrophages in pancreas. 7S,14R-diHDHA induced MSC functions in promoting MIN6 β-cell viability and insulin secretion. 7S,14R-diHDHA induced MSC paracrine functions by increasing the generation of hepatocyte growth factor and vascular endothelial growth factor. Furthermore, 7S,14R-diHDHA enhanced MSC functions to ameliorate diabetes-caused pericyte loss in diabetic retinopathy by increasing their density in retina in db/db mice. Discussion: Our findings provide a novel strategy for improving therapy for diabetes and diabetic retinopathy using 7S,14R-diHDHA-primed MSCs.

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage T2DM is widely documented. These dietary compounds exert their beneficial effects through several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorate diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

Gene expression analysis reveals diabetes-related gene signatures

BACKGROUND

Diabetes is a spectrum of metabolic diseases affecting millions of people worldwide. The loss of pancreatic β-cell mass by either autoimmune destruction or apoptosis, in type 1-diabetes (T1D) and type 2-diabetes (T2D), respectively, represents a pathophysiological process leading to insulin deficiency. Therefore, therapeutic strategies focusing on restoring β-cell mass and β-cell insulin secretory capacity may impact disease management. This study took advantage of powerful integrative bioinformatic tools to scrutinize publicly available diabetes-associated gene expression data to unveil novel potential molecular targets associated with β-cell dysfunction.

METHODS

A comprehensive literature search for human studies on gene expression alterations in the pancreas associated with T1D and T2D was performed. A total of 6 studies were selected for data extraction and for bioinformatic analysis. Pathway enrichment analyses of differentially expressed genes (DEGs) were conducted, together with protein-protein interaction networks and the identification of potential transcription factors (TFs). For noncoding differentially expressed RNAs, microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), which exert regulatory activities associated with diabetes, identifying target genes and pathways regulated by these RNAs is fundamental for establishing a robust regulatory network.

RESULTS

Comparisons of DEGs among the 6 studies showed 59 genes in common among 4 or more studies. Besides alterations in mRNA, it was possible to identify differentially expressed miRNA and lncRNA. Among the top transcription factors (TFs), HIPK2, KLF5, STAT1 and STAT3 emerged as potential regulators of the altered gene expression. Integrated analysis of protein-coding genes, miRNAs, and lncRNAs pointed out several pathways involved in metabolism, cell signaling, the immune system, cell adhesion, and interactions. Interestingly, the GABAergic synapse pathway emerged as the only common pathway to all datasets.

CONCLUSIONS

This study demonstrated the power of bioinformatics tools in scrutinizing publicly available gene expression data, thereby revealing potential therapeutic targets like the GABAergic synapse pathway, which holds promise in modulating α-cells transdifferentiation into β-cells.

A novel clinical model for risk prediction and stratification of new-onset diabetes mellitus after distal pancreatectomy

Background

The incidence of new-onset diabetes mellitus (NODM) after distal pancreatectomy (DP) remains high. Few studies have focused on NODM in patients with pancreatic benign or low-grade malignant lesions (PBLML). This study aimed to develop and validate an effective clinical model for risk prediction and stratification of NODM after DP in patients with PBLML.

Methods

A follow-up survey was conducted to investigate NODM in patients without preoperative DM who underwent DP. Four hundred and forty-eight patients from Peking Union Medical College Hospital (PUMCH) and 178 from Guangdong Provincial People's Hospital (GDPH) met the inclusion criteria. They constituted the training cohort and the validation cohort, respectively. Univariate and multivariate Cox regression, as well as least absolute shrinkage and selection operator (LASSO) analyses, were used to identify the independent risk factors. The nomogram was constructed and verified. Concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) were applied to assess its predictive performance and clinical utility. Accordingly, the optimal cut-off point was determined by maximally selected rank statistics method, and the cumulative risk curves for the high- and low-risk populations were plotted to evaluate the discrimination ability of the nomogram.

Results

The median follow-up duration was 42.8 months in the PUMCH cohort and 42.9 months in the GDPH cohort. The postoperative cumulative 5-year incidences of DM were 29.1% and 22.1%, respectively. Age, body mass index (BMI), length of pancreatic resection, intraoperative blood loss, and concomitant splenectomy were significant risk factors. The nomogram demonstrated significant predictive utility for post-pancreatectomy DM. The C-indexes of the nomogram were 0.739 and 0.719 in the training and validation cohorts, respectively. ROC curves demonstrated the predictive accuracy of the nomogram, and the calibration curves revealed that prediction results were in general agreement with the actual results. The considerable clinical applicability of the nomogram was certified by DCA. The optimal cut-off point for risk prediction value was 2.88, and the cumulative risk curves of each cohort showed significant differences between the high- and low-risk groups.

Conclusions

The nomogram could predict and identify the NODM risk population, and provide guidance to physicians in monitoring and controlling blood glucose levels in PBLML patients after DP.

Oxidative stress signaling in the pathogenesis of diabetic cardiomyopathy and the potential therapeutic role of antioxidant naringenin

Diabetes mellitus (DM) is one of the most prevalent metabolic disorders that poses a global threat to human health. It can lead to complications in multiple organs and tissues, owing to its wide-ranging impact on the human body. Diabetic cardiomyopathy (DCM) is a specific cardiac manifestation of DM, which is characterized by heart failure in the absence of coronary heart disease, hypertension and valvular heart disease. Given that oxidative stress is a key factor in the pathogenesis of DCM, intervening to mitigate oxidative stress may serve as a therapeutic strategy for managing DCM. Naringenin is a natural product with anti-oxidative stress properties that can suppress oxidative damage by regulating various oxidative stress signaling pathways. In this review, we address the relationship between oxidative stress and its primary signaling pathways implicated in DCM, and explores the therapeutic potential of naringenin in DCM.

Necrosis, netosis, and apoptosis in pulmonary tuberculosis and type-2 diabetes mellitus. Clues from the patient's serum

Pulmonary tuberculosis (PTB) and type 2 diabetes mellitus (T2DM) are two inflammatory diseases whose pathology involves neutrophils (NEU) as key participants. Countless inflammatory elements produced at the lesion sites leak into the blood and are distributed systemically. The study aimed to investigate the effect of the serum of patients with PTB, T2DM, and PTB + T2DM on the cellular and nuclear morphology of healthy NEU. Monolayers of NEU were prepared and incubated with sera from PTB (n꓿ 10), T2DM (n꓿10), PTB + T2DM (n꓿ 10) patients, or sera from healthy people (n = 10). Monolayers were stained for histones, elastase, and myeloperoxidase for NETosis, annexin V for apoptosis, and Iris fuchsia for necrosis. Hoechst stain (DNA) was used to identify the nuclear alterations. Necrosis was the predominant alteration. Sera from PTB + T2DM were the most potent change inducers. Normal sera did not induce cell alterations. The blood of TBP and T2DM patients carries a myriad of abnormal elements that induce necrosis of NEU in normal people, thus reflecting what might occur in the neutrophils of the patients themselves. These findings reinforce the participation of NEU in the pathology of these diseases. Necrosis is expected to be the most frequent neutrophil-induced alteration in tuberculosis and diabetes mellitus.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic human embryonic stem cell-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional roles of many loci remain unexplored. Here, we engineered isogenic knockout human embryonic stem cell lines for 20 genes associated with T2D risk. We examined the impacts of each knockout on β cell differentiation, functions, and survival. We generated gene expression and chromatin accessibility profiles on β cells derived from each knockout line. Analyses of T2D-association signals overlapping HNF4A-dependent ATAC peaks identified a likely causal variant at the FAIM2 T2D-association signal. Additionally, the integrative association analyses identified four genes (CP, RNASE1, PCSK1N, and GSTA2) associated with insulin production, and two genes (TAGLN3 and DHRS2) associated with β cell sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental line and identified a single likely functional variant at each of 23 T2D-association signals.

The effect of swimming and running exercises on oxidant-antioxidant and lipid profiles in streptozotocin-induced diabetic rats

Background

Lifestyle changes in Diabetes Mellitus (DM) positively affect blood glucose and all risk factors. This study aims to determine the effect of swimming and running exercises on oxidant-antioxidant and lipid profiles in streptozotocin (STZ)-induced type 1 diabetic and non-diabetic rats.

Methods

We included forty-eight adult male Wistar albino rats in this study, and we randomly classified them into six groups (eight per group). The groups were organized as Control Sedentary, Control Exercise-swimming, Control Exercise-running (CE-r), Diabetes Sedentary (DS), Diabetes Exercise-swimming (DE-s), and Diabetes Exercise running (DE-r). Half of these rats were subjected to experimental diabetes via STZ. We evaluated total oxidant capacity (TOC), total antioxidant capacity (TAC), superoxide dismutase (SOD), and as lipid parameters: high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides. The rats were sacrificed at the end of the four weeks.

Results

We found a significant difference between DE-s and DE-r groups in terms of TOC (p =0.043) and SOD (p =0.030). The highest TAC was found in the CE-r group, and the highest TOC was found in the DS group. Exercise significantly reduced LDL levels. There was no significant difference between the DE-s and DE-r groups (p =0.084) for lipid profiles (HDL).

Conclusion

Based on the lower TOC (oxidant) and higher SOD (antioxidant) levels in the diabetic running group, these results suggest that running may be more beneficial than swimming for diabetics. HIPPOKRATIA 2023, 27 (4):148-154.

Systematic review of type 1 diabetes biomarkers reveals regulation in circulating proteins related to complement, lipid metabolism, and immune response

BACKGROUND

Type 1 diabetes (T1D) results from an autoimmune attack of the pancreatic β cells that progresses to dysglycemia and symptomatic hyperglycemia. Current biomarkers to track this evolution are limited, with development of islet autoantibodies marking the onset of autoimmunity and metabolic tests used to detect dysglycemia. Therefore, additional biomarkers are needed to better track disease initiation and progression. Multiple clinical studies have used proteomics to identify biomarker candidates. However, most of the studies were limited to the initial candidate identification, which needs to be further validated and have assays developed for clinical use. Here we curate these studies to help prioritize biomarker candidates for validation studies and to obtain a broader view of processes regulated during disease development.

METHODS

This systematic review was registered with Open Science Framework ( https://doi.org/10.17605/OSF.IO/N8TSA ). Using PRISMA guidelines, we conducted a systematic search of proteomics studies of T1D in the PubMed to identify putative protein biomarkers of the disease. Studies that performed mass spectrometry-based untargeted/targeted proteomic analysis of human serum/plasma of control, pre-seroconversion, post-seroconversion, and/or T1D-diagnosed subjects were included. For unbiased screening, 3 reviewers screened all the articles independently using the pre-determined criteria.

RESULTS

A total of 13 studies met our inclusion criteria, resulting in the identification of 266 unique proteins, with 31 (11.6%) being identified across 3 or more studies. The circulating protein biomarkers were found to be enriched in complement, lipid metabolism, and immune response pathways, all of which are found to be dysregulated in different phases of T1D development. We found 2 subsets: 17 proteins (C3, C1R, C8G, C4B, IBP2, IBP3, ITIH1, ITIH2, BTD, APOE, TETN, C1S, C6A3, SAA4, ALS, SEPP1 and PI16) and 3 proteins (C3, CLUS and C4A) have consistent regulation in at least 2 independent studies at post-seroconversion and post-diagnosis compared to controls, respectively, making them strong candidates for clinical assay development.

CONCLUSIONS

Biomarkers analyzed in this systematic review highlight alterations in specific biological processes in T1D, including complement, lipid metabolism, and immune response pathways, and may have potential for further use in the clinic as prognostic or diagnostic assays.

Antioxidant and anti-inflammatory properties of ginsenoside Rg1 for hyperglycemia in type 2 diabetes mellitus: systematic reviews and meta-analyses of animal studies

Background: According to existing laboratory data, ginsenoside Rg1 may help cure diabetes and its complications by reducing oxidative stress (OS) and managing inflammation. However, this conclusion lacks reliability and is unclear. As a result, the purpose of this systematic review and meta-analysis was to evaluate the antioxidant and anti-inflammatory effects of ginsenoside Rg1 in the treatment of diabetes and its complications. Methods: We searched for relevant studies published through December 2022, including electronic bibliographic databases such as PubMed, EMBASE, Web of Science, CNKI, and Wanfang. The SYstematic Review Center for Laboratory Animal Experimentation Risk of Bias (SYRCLE RoB) tool was used to conduct a meta-analysis to assess the methodological quality of animal research. The meta-analysis was conducted using RevMan5.4 software, following the Cochrane Handbook for Systematic Reviews of Interventions. This study is registered in the International Systems Review Prospective Registry (PROSPERO) as CRD42023386830. Results: Eighteen eligible studies involving 401 animals were included. Ginsenoside Rg1 was significantly correlated with blood glucose (BG), insulin levels, body weight, superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels. In addition, according to subgroup analysis, the hypoglycemic, anti-inflammatory, and antioxidant effects of ginsenoside Rg1 in type 2 diabetic animals were not affected by experimental species, modeling, experimental drug dosage, or course of treatment. Conclusion: This meta-analysis presents a summary of the hypoglycemic effects of ginsenoside Rg1, which are achieved through anti-inflammatory and antioxidant mechanisms. These findings provide evidence-based support for the medical efficacy of ginsenoside Rg1. Specifically, ginsenoside Rg1 reduced MDA levels and restored SOD activity to exert its antioxidant activity. It had a positive effect on the reduction of IL-6 and TNF-α levels. However, the inclusion of studies with low methodological quality and the presence of publication bias may undermine the validity of the results. Further investigation with a more rigorous experimental design and comprehensive studies is necessary to fully understand the specific glycemic mechanisms of ginsenosides. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier https://CRD42023386830.

Actinidia deliciosa Extract as a Promising Supplemental Agent for Hepatic and Renal Complication-Associated Type 2 Diabetes (In Vivo and In Silico-Based Studies)

Type 2 diabetes (T2D) is a chronic metabolic condition associated with obesity, oxidative stress-mediated inflammation, apoptosis, and impaired insulin signaling. The utilization of phytochemical therapy generated from plants has emerged as a promising approach for the treatment of diabetes and its complications. Kiwifruit is recognized for its substantial content of antioxidative phenolics. Therefore, this work aimed to examine the effect of Actinidia deliciosa (kiwi fruit) on hepatorenal damage in a high-fat diet (HFD) and streptozotocin (STZ)-induced T2D in rats using in vivo and in silico analyses. An increase in hepatic and renal lipid peroxidation was observed in diabetic rats accompanied by a decrease in antioxidant status. Furthermore, it is important to highlight that there were observable inflammatory and apoptotic responses in the hepatic and renal organs of rats with diabetes, along with a dysregulation of the phosphorylation levels of mammalian target of rapamycin (mTOR), protein kinase B (Akt), and phosphoinositide 3-kinase (PI3K) signaling proteins. However, the administration of kiwi extract to diabetic rats alleviated hepatorenal dysfunction, inflammatory processes, oxidative injury, and apoptotic events with activation of the insulin signaling pathway. Furthermore, molecular docking and dynamic simulation studies revealed quercetin, chlorogenic acid, and melezitose as components of kiwi extract that docked well with potential as effective natural products for activating the silent information regulator 1(SIRT-1) pathway. Furthermore, phenolic acids in kiwi extract, especially syringic acid, P-coumaric acid, caffeic acid, and ferulic acid, have the ability to inhibit the phosphatase and tensin homolog (PTEN) active site. In conclusion, it can be argued that kiwi extract may present a potentially beneficial adjunctive therapy approach for the treatment of diabetic hepatorenal complications.

Protective Properties of Spheroidal Taxifolin Form in Streptozotocin-Induced Diabetic Rats

One of the key factors in the pathogenesis of diabetes and its complications is oxidative stress. To inhibit this process, antioxidants may be helpful. Herein, we focused on the protective properties of taxifolin spheroidal form (TS) in the streptozotocin rat model of diabetes mellitus. After 4 weeks of treatment with TS, the fasting blood glucose level of the diabetic animals decreased by 12% compared with the level right after the injection of streptozotocin. While the feed intake in the untreated diabetic rats increased by 5.3% compared with the healthy group, the TS-treated group showed a pronounced 15.3% decrease. Therapeutic administration of TS has a protective effect on the pancreas and the liver against the cytotoxic action of streptozotocin. The plasma antioxidant capacity of all diabetic groups appeared to be approximately 15% lower than in healthy rats with no significant difference between the TS-treated and untreated diabetic animals. Apparently, this can be attributed to taxifolin and plasma proteins binding. These data demonstrate the potential of TS in antidiabetic therapy.

Impacts of MicroRNA-483 on Human Diseases

MicroRNAs (miRNAs) are short non-coding RNA molecules that regulate gene expression by targeting specific messenger RNAs (mRNAs) in distinct cell types. This review provides a com-prehensive overview of the current understanding regarding the involvement of miR-483-5p and miR-483-3p in various physiological and pathological processes. Downregulation of miR-483-5p has been linked to numerous diseases, including type 2 diabetes, fatty liver disease, diabetic nephropathy, and neurological injury. Accumulating evidence indicates that miR-483-5p plays a crucial protective role in preserving cell function and viability by targeting specific transcripts. Notably, elevated levels of miR-483-5p in the bloodstream strongly correlate with metabolic risk factors and serve as promising diagnostic markers. Consequently, miR-483-5p represents an appealing biomarker for predicting the risk of developing diabetes and cardiovascular diseases and holds potential as a therapeutic target for intervention strategies. Conversely, miR-483-3p exhibits significant upregulation in diabetes and cardiovascular diseases and has been shown to induce cellular apoptosis and lipotoxicity across various cell types. However, some discrepancies regarding its precise function have been reported, underscoring the need for further investigation in this area.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic hESC-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional role of many loci has remained unexplored. In this study, we engineered isogenic knockout human embryonic stem cell (hESC) lines for 20 genes associated with T2D risk. We systematically examined β-cell differentiation, insulin production and secretion, and survival. We performed RNA-seq and ATAC-seq on hESC-β cells from each knockout line. Analyses of T2D GWAS signals overlapping with HNF4A-dependent ATAC peaks identified a specific SNP as a likely causal variant. In addition, we performed integrative association analyses and identified four genes ( CP, RNASE1, PCSK1N and GSTA2 ) associated with insulin production, and two genes ( TAGLN3 and DHRS2 ) associated with sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental hESC line, to identify a single likely functional variant at each of 23 T2D GWAS signals.

Over-activation of TRPM2 ion channel accelerates blood-spinal cord barrier destruction in diabetes combined with spinal cord injury rat

Spinal cord injury (SCI) is a devastating neurological disorder that often results in loss of motor and sensory function. Diabetes facilitates the blood-spinal cord barrier (BSCB) destruction and aggravates SCI recovery. However, the molecular mechanism underlying it is still unclear. Our study has focused on transient receptor potential melastatin 2 (TRPM2) channel and investigated its regulatory role on integrity and function of BSCB in diabetes combined with SCI rat. We have confirmed that diabetes is obviously not conductive to SCI recovery through accelerates BSCB destruction. Endothelial cells (ECs) are the important component of BSCB. It was observed that diabetes significantly worsens mitochondrial dysfunction and triggers excessive apoptosis of ECs in spinal cord from SCI rat. Moreover, diabetes impeded neovascularization in spinal cord from SCI rat with decreases of VEGF and ANG1. TRPM2 acts as a cellular sensor of ROS. Our mechanistic studies showed that diabetes significantly induces elevated ROS level to activate TRPM2 ion channel of ECs. Then, TRPM2 channel mediated the Ca²⁺ influx and subsequently activated p-CaMKII/eNOS pathway, and which in turn triggered the ROS production. Consequently, over-activation of TRPM2 ion channel results in excessive apoptosis and weaker angiogenesis during SCI recovery. Inhibition of TRPM2 with 2-Aminoethyl diphenylborinate (2-APB) or TRPM2 siRNA will ameliorate the apoptosis of ECs and promote angiogenesis, subsequently enhance BSCB integrity and improve the locomotor function recovery of diabetes combined with SCI rat. In conclusion, TRPM2 channel may be a key target for the treatment of diabetes combined with SCI rat.

Mechanisms of Oxidative Stress in Metabolic Syndrome

Metabolic syndrome is a cluster of conditions associated with the risk of diabetes mellitus type 2 and cardiovascular diseases (CVDs). Metabolic syndrome is closely related to obesity. Increased adiposity promotes inflammation and oxidative stress, which are precursors of various complications involving metabolic syndrome components, namely insulin resistance, hypertension, and hyperlipidemia. An increasing number of studies confirm the importance of oxidative stress and chronic inflammation in the etiology of metabolic syndrome. However, few studies have reviewed the mechanisms underlying the role of oxidative stress in contributing to metabolic syndrome. In this review, we highlight mechanisms by which reactive oxygen species (ROS) increase mitochondrial dysfunction, protein damage, lipid peroxidation, and impair antioxidant function in metabolic syndrome. Biomarkers of oxidative stress can be used in disease diagnosis and evaluation of severity.

Using mass spectrometry to identify neoantigens in autoimmune diseases: The type 1 diabetes example

In autoimmune diseases, recognition of self-antigens presented by major histocompatibility complex (MHC) molecules elicits unexpected attack of tissue by autoantibodies and/or autoreactive T cells. Post-translational modification (PTM) may alter the MHC-binding motif or TCR contact residues in a peptide antigen, transforming the tolerance to self to autoreactivity. Mass spectrometry-based immunopeptidomics provides a valuable mechanism for identifying MHC ligands that contain PTMs and can thus provide valuable insights into pathogenesis and therapeutics of autoimmune diseases. A plethora of PTMs have been implicated in this process, and this review highlights their formation and identification.

Systematic review of type 1 diabetes biomarkers reveals regulation in circulating proteins related to complement, lipid metabolism, and immune response

Aims

Type 1 diabetes (T1D) results from an autoimmune attack of the pancreatic β cells that progresses to dysglycemia and symptomatic hyperglycemia. Current biomarkers to track this evolution are limited, with development of islet autoantibodies marking the onset of autoimmunity and metabolic tests used to detect dysglycemia. Therefore, additional biomarkers are needed to better track disease initiation and progression. Multiple clinical studies have used proteomics to identify biomarker candidates. However, most of the studies were limited to the initial candidate identification, which needs to be further validated and have assays developed for clinical use. Here we curate these studies to help prioritize biomarker candidates for validation studies and to obtain a broader view of processes regulated during disease development.

Methods

This systematic review was registered with Open Science Framework (DOI 10.17605/OSF.IO/N8TSA). Using PRISMA guidelines, we conducted a systematic search of proteomics studies of T1D in the PubMed to identify putative protein biomarkers of the disease. Studies that performed mass spectrometry-based untargeted/targeted proteomic analysis of human serum/plasma of control, pre-seroconversion, post-seroconversion, and/or T1D-diagnosed subjects were included. For unbiased screening, 3 reviewers screened all the articles independently using the pre-determined criteria.

Results

A total of 13 studies met our inclusion criteria, resulting in the identification of 251 unique proteins, with 27 (11%) being identified across 3 or more studies. The circulating protein biomarkers were found to be enriched in complement, lipid metabolism, and immune response pathways, all of which are found to be dysregulated in different phases of T1D development. We found a subset of 3 proteins (C3, KNG1 & CFAH), 6 proteins (C3, C4A, APOA4, C4B, A2AP & BTD) and 7 proteins (C3, CLUS, APOA4, C6, A2AP, C1R & CFAI) have consistent regulation between multiple studies in samples from individuals at pre-seroconversion, post-seroconversion and post-diagnosis compared to controls, respectively, making them strong candidates for clinical assay development.

Conclusions

Biomarkers analyzed in this systematic review highlight alterations in specific biological processes in T1D, including complement, lipid metabolism, and immune response pathways, and may have potential for further use in the clinic as prognostic or diagnostic assays.

Ethyl-acetate fraction from a cinnamon-cortex extract protects pancreatic β-cells from oxidative stress damage

Background: The pathogenesis of diabetes mellitus is mediated mainly by oxidative stress produced by damaged pancreatic β-cells. We identified that an ethyl-acetate fraction (EA) from a cinnamon-cortex extract (CCE) is rich in flavonoid, and showed no toxicity to β cells. Objective: In this study, we evaluated the pharmacologic activities of EA on pancreatic β cells using a model of oxidative stress induced by H₂O₂ or alloxan. Results: The results showed that EA could significantly reduce reactive oxygen (ROS) accumulation to improve the survival of cells. Western blot showed that EA treatment upregulated expression of nuclear factor erythroid 2 related factor 2, heme oxygenase-1, and gamma glutamylcysteine synthetase. The same model study found that EA also can protect β cells against the apoptosis induced by oxidative stress. Furthermore, EA can enhance insulin secretion in rat and mouse β cell lines treated or not with alloxan or H₂O₂. The expression of the insulin transcription factor PDX-1 increased in an EA concentration-dependent manner. At last, the major functional compounds of EA analysis showed that three compounds, cinnamyl alcohol, coumarin, and cinnamic acid, had similar effects as EA. Conclusions: In sum, our data suggested that EA fraction from CCE can protect β cells from oxidative stress, and increase insulin secretion to improve the function of β cells. This function might be due to these three compounds found in EA. Our findings provide a theoretical basis and functional molecules for the use of CCE against diabetes mellitus.