Vitamin D Alleviates Type 2 Diabetes Mellitus by Mitigating Oxidative Stress-Induced Pancreatic β-Cell Impairment

The acetylation of Ganoderma applanatum polysaccharides on ameliorating T2DM-induced hepatic and colonic injuries by modulating the Nrf2/keap1-TLR4/NFκB-Bax/Bcl-2 pathways

It was imperative to discover and utilize high-efficiency, non-toxic substances for the prevention and management of type 2 diabetes mellitus (T2DM) and its associated complications, given the escalating prevalence and significant global health burden. In the present study, the acetylated Ganoderma applanatum polysaccharide (A-GAP) was successfully obtained and characterized, demonstrating excellent efficacy in ameliorating organ damage induced by T2DM through targeted modulation of the gut-liver axis. The physiological and molecular biological findings indicated that A-GAP may modulate the Nrf2/Keap1-TLR4/NFκB-Bax/Bcl-2 signaling pathway network, thereby mitigating oxidative stress and the subsequent inflammatory response, ultimately alleviating the inhibitory effects of IRS and insulin resistance. Besides, the regulatory impact of A-GAP on the gut-liver axis had been confirmed by its ability to maintain intestinal barrier integrity and increase levels of intestinal tight junction proteins, effectively preventing endotoxin translocation to the liver. This discovery highlighted the potential of A-GAP as a promising option for functional or nutritional foods and pharmaceuticals in managing T2DM and its complications, showcasing the significance of acetylation in enhancing the bioactivities of natural substances.

Exploring the anti-inflammatory potential of vitamin D in cardiometabolic diseases

The prevalence of cardiometabolic diseases is rising, and this is fuelled by inflammation, which tends to be worse in individuals with vitamin D (VD) deficiency. While non-steroidal anti-inflammatory interventions are available, they present with coagulation events. Hence, alternative therapy in the form of VD supplements is gaining research interest. This study reviewed the effect of VD supplementation on inflammation, focusing on nuclear factor kappa-beta (NF-κβ), tumour necrosis factor-alpha (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) across different cardiometabolic disease. Thirty-seven studies, 16 rodent models and 21 clinical studies were evaluated. The study considered evidence from rodent models to understand the effect of VD on these markers of inflammation and its translatability to clinical studies. While the potential benefits of VD were notable in rodents, these effects were less consistent in clinical studies. Notably, rodent models showed a more pronounced impact of VD in reducing NF-κβ and TNF-α; however, clinical trials reported conflicting findings. Furthermore, the VD was important in reducing MCP-1 across different rodent models; this was partially demonstrated in clinical trials. Based on these findings, VD modulates inflammation in cardiometabolic disease by inhibiting the activation of NF-κβ and suppressing the production of TNF-α and MCP-1. Although VD has some possible benefits in rodent models, the translatability of these findings in clinical trials is limited. Hence, the presented evidence in this study calls for further randomised controlled trials to assess the effect of VD on inflammation in patients living with different conditions as a therapy to curb the inflammation and the risk thereof. Future trials should also focus on exploring the VD dose-response, optimal dose, and duration of VD intervention among these patients that may offer optimal benefits on inflammation.

Metformin and vitamin D combination therapy ameliorates type 2 diabetes mellitus-induced renal injury in male Wistar rats

Diabetic kidney disease is a major microvascular diabetes mellitus (DM) complication clinically associated with a gradual renal function decline. Although metformin is a common drug for managing DM, however, monotherapy treatment with any antidiabetic drug will necessitate dosage increment since type 2 DM (T2DM) deteriorates over time due to the increasing pancreatic β-cell dysfunction and will eventually require a combination therapy approach with another antidiabetic medication. Vitamin D is a food supplement that has been proven to have antidiabetic and reno-protective activities. Hence, we explore the combination of vitamin D and metformin on T2DM-induced renal dysfunction. Thirty male Wistar rats were randomized into five (5) groups: control, diabetes untreated, diabetics treated with metformin, vitamin D, and vitamin D + metformin. Vitamin D and metformin significantly reversed DM-induced hyperglycemia, electrolyte imbalance, and dyslipidemia. Also, vitamin D and metformin reversed T2DM-induced increase in serum creatinine and urea and renal lactate, LDH, and oxido-inflammatory response. These observed alterations were accompanied by an increase in proton pump activities and modulation of Nrf2/Nf-κB and XO/UA signaling. This study revealed that vitamin D and/or metformin ameliorated T2DM-induced renal injury.

Vitamin D and Type 2 Diabetes Mellitus: Molecular Mechanisms and Clinical Implications-A Narrative Review

Vitamin D has been widely studied for its implications on type 2 diabetes mellitus, a chronic condition characterized by insulin resistance, inflammation, and metabolic dysfunction. This review explores the molecular mechanisms underpinning vitamin D's effects on glucose metabolism, inflammation, and adipogenesis, while assessing its potential clinical applications in type 2 diabetes. In its 1,25-dihydroxyvitamin D3 form, vitamin D modulates various metabolic processes, affecting proinflammatory cytokines and activating the AMPK pathway, inhibiting mTOR signaling, and promoting adipocyte differentiation. These effects enhance insulin sensitivity and reduce chronic inflammation, key contributors to metabolic dysfunction. In this context, the progression of prediabetes has been linked to vitamin D, which limits pathological progression and increases the likelihood of restoring a normal metabolic state, crucial in diabetes progression. Moreover, vitamin D has been reported to reduce the likelihood of developing diabetes by 15%, particularly in doses higher than the traditional recommendations for bone health. Despite promising evidence, discrepancies in study designs, serum vitamin D measurements, and population-specific factors highlight the need for standardized methodologies and personalized approaches. In conclusion, vitamin D has complementary therapeutic potential in treating type 2 diabetes, revealing gaps in research, such as optimal dosing and long-term effects across populations. Future studies should integrate molecular insights into clinical practice to optimize vitamin D's impact on metabolic health.

Relevant Serum Endoplasmic Reticulum Stress Biomarkers in Type 2 Diabetes and Its Complications: A Systematic Review and Meta-Analysis

Endoplasmic reticulum stress (ERS) is activated in all cells by stressors such as hyperglycemia. However, it remains unclear which specific serum biomarkers of ERS are consistently altered in type 2 diabetes (T2D). We aimed to identify serum ERS biomarkers that are consistently altered in T2D and its complications, and their correlation with metabolic and anthropometric variables. We performed a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-Analyses and Systematic Reviews of Observational Studies (MOOSE). The risk of bias was assessed using the Newcastle-Ottawa scale. Random-effects models weighted by the inverse variance were employed to estimate the standardized mean difference and correlations as effect size measures. Indicators of heterogeneity and meta-regressions were evaluated. Of the 1206 identified studies, 22 were finally included, representing 11,953 subjects (2224 with T2D and 9992 non-diabetic controls). Most studies were of high quality. Compared with controls, subjects with T2D had higher circulating levels of heat shock protein 70 (HSP70; SMD: 2.30, 95% CI 1.13-3.46; p < 0.001) and secretagogin (SMD: 0.60, 95%CI 0.19-1.01; p < 0.001). They also had higher serum levels of peroxiredoxin-1, -2, -4, and -6. Secretagogin inversely correlated with HOMA-IR, yet positively correlated with HOMA-B, HbA1c, and FPG. PRX4 negatively correlated with HbA1c and FPG, while HSP70 positively correlated with HbA1c. In conclusion, six ERS biomarkers are consistently elevated in human T2D and correlate with glycemic control, insulin resistance, and β-cell function. Emerging evidence links serum ERS biomarkers to diabetes complications, but further research should evaluate their prognostic implications.

Physical exercise improved the hematological effect of vitamin D in type 2 diabetes mellitus-induced nephrotoxicity in rats

Introduction

Globally, one of the major causes of renal dysfunction is diabetes mellitus (DM), and diabetic-induced nephrotoxicity has been linked with anemia. Presently, numerous antidiabetic drugs have been designed for the management of this disorder but they possess their undesirable effects such as anemia and acute kidney injury. Hence, we explore the use of vitamin D with or without exercise for the management of DM-induced renal dysfunction.

Methods

Thirty-six (36) Wistar rats were randomly separated into six (6) groups: control (vehicle treated), diabetes untreated (HFD + STZ), diabetes + vitamin D (HFD + STZ + vitamin D), diabetes + exercise (HFD + STZ + exercise), diabetes + vitamin D + exercise (HFD + STZ + vitamin D+ exercise), diabetes + metformin (HFD + STZ + metformin).

Results

Vitamin D with or without exercise significantly reduced T2DM-induced hyperglycemia. Also, a decrease in T2DM-induced increase in urea, creatinine, lactate dehydrogenase, lactate, cholesterol, and triglyceride and a rise in DM-associated reduction in high-density lipoprotein. These events were associated with a significant increase in red blood cells, hematocrit value, hemoglobin, erythropoietin, and a decrease in white blood cell count. Furthermore, vitamin D with or without exercise reversed T2DM-induced increase in pro-oxidant and pro-inflammatory markers. This observed oxido-inflammatory response was associated with a significant increase in xanthine oxidase activities and uric acid concentration. Interestingly, better recovery rates from DM-associated hematological imbalance were discovered in rats co-treated with vitamin D and exercise.

Conclusion

Our findings revealed that exercise enhanced the hematological effect of vitamin D in HFD + STZ-induced T2DM animals.

Relationship of thyroid parameters with chronic inflammation in patients with euthyroid type 2 diabetes

Aims

We evaluated the association of multiple thyroid parameters with the levels interleukin 6 (IL6) and interleukin 8 (IL8) in patients with euthyroid type 2 diabetes (T2D).

Methods

A total of 166 adults with euthyroid T2D were examined. Serum IL6, IL8, triiodothyronine (FT3), free thyroxin (FT4), thyroid-stimulating hormone (TSH), five thyroid sensitivity indexes (FT3/FT4, TSH index [TSHI], thyrotroph T4 resistance index [TT4RI], thyroid feedback quantile-based index by FT3 [TFQIFT3], and TFQIFT4), and biochemical parameters were determined.

Results

The median age was 64 years (IQR: 54.75,70) and the median duration of diabetes was 10 years (IQR: 3,18). Patients with high levels of IL6 (≥2.38 pg/mL) had lower levels of FT3 and TFQIFT3 (P<0.05). Patients with high levels of IL8 (≥18.1 pg/mL) had lower levels of TSH and higher levels of FT4 (P<0.05). IL6 was negatively correlated with FT3 (r=-0.359, P<0.001), TFQIFT3 (r=-0.273, P=0.009), and FT3/FT4 (r=-0.22, P=0.037). IL8 was negatively correlated with TSH (r=-0.256, P=0.01), TSHI (r=-0.226, P=0.033), and TT4RI (r=-0.244, P=0.021). Binary logistic regression analysis with multiple adjusted models showed that a high level of IL6 was negatively associated with FT3 (aOR: 0.529; 95%CI: 0.302, 0.926, P=0.026), and that a high level of IL8 was negatively associated with TSH (aOR: 0.343; 95%CI: 0.155, 0.759; P=0.008) and TT4RI (aOR: 0.398;95%CI: 0.191, 0.831; P=0.014).

Conclusion

Patients with euthyroid T2D who had lower levels of FT3 had significantly higher levels of IL6, and those with lower levels of TSH and TT4RI had significantly higher levels of IL8.

Vitamin D3 attenuates autoimmune thyroiditis by regulating Th17/Treg cell differentiation via YAP/JAK1/STAT1 axis

BACKGROUND

Autoimmune thyroiditis (AITD) is an organ-specific autoimmune disease. Substantial evidence suggests that Vitamin D (VitD) deficiency is closely associated with an increased risk of AITD. However, the effects of VitD3 on immune cells, especially Th17/Treg cell subsets, and the underlying molecular mechanism in AITD have not yet been investigated.

METHODS

An experimental autoimmune thyroiditis (EAT) mouse model was established with a high-iodine diet. After 8 weeks, thyroid injury was assessed using hematoxylin and eosin (H&E) staining. ELISA was employed to measure serum levels of thyroxine (T3 and T4), thyroid autoimmune antibodies (Tg-Ab and TPO-Ab), and inflammatory cytokines. Flow cytometry and multiplex fluorescence immunohistochemical (mIHC) assays were used to analyze Th17/Treg cell subsets. The CCK-8 and flow cytometry assays were used to determine cell viability and apoptosis.

RESULTS

Administration of VitD3 reduced thyroid follicle destruction, decreased lymphocyte infiltration, and lowered T3, T4, Tg-Ab, and TPO-Ab serum levels in EAT mice. VitD3 treatment also reduced the frequency of Th17 cells while promoting the Treg cell subset both in the thyroid tissue and in the splenocytes cultured in vitro. Furthermore, VitD3 administration suppressed the production of inflammatory cytokines in EAT mice. VitD3 was also found to regulate Treg cells' differentiation, viability, and apoptosis. Mechanistically, we discovered that VitD3 treatment upregulated YAP expression and activated the JAK/STAT pathway. Rescue assays confirmed that depletion of YAP counteracted the effects of VitD3 on Treg cell differentiation and function.

CONCLUSION

Vitamin D3 attenuates AITD by modulating Th17/Treg cell balance via regulating the YAP/JAK1/STAT1 axis.

Research Progress of Pyroptosis in Diabetic Kidney Disease

Pyroptosis, known as one typical mode of programmed cell death, is generally characterized by the cleaved gasdermin family (GSDMs) forming pores in the cell membrane and inducing cell rupture, and the activation of aspartate-specific proteases (caspases) has also been found during this process. Diabetic Kidney Disease (DKD) is caused by the complication of diabetes in the kidney, and the most important kidney's function, Glomerular Filtration Rate (GFR), happens to drop to less than 90% of its usual and even lead to kidney failure in severe cases. The persistent inflammatory state induced by high blood glucose implies the key pathology of DKD, and growing evidence shows that pyroptosis serves as a significant contributor to this chronic immune-mediated inflammatory disorder. Currently, the expanded discovery of GSDMs, pyroptosis, and its association with innate immunity has been more attractive, and overwhelming research is needed to sort out the implication of pyroptosis in DKD pathology. In this review, we comb both classical studies and newly founds on pyroptosis, prick off the novel awakening of pyroptosis in DKD, and center on the significance of pyroptosis in DKD treatment, aiming to provide new research targets and treatment strategies on DKD.

Correlation between insulin resistance and the rate of neutrophils-lymphocytes, monocytes-lymphocytes, platelets-lymphocytes in type 2 diabetic patients

BACKGROUND

Insulin resistance (IR) was a prominent feature commonly observed in individuals with type 2 diabetes mellitus (T2DM). T2DM Individuals often exhibited a concomitant presence of low-grade chronic inflammation. In this study conducted retrospectively, the aim was to investigate the connection between neutrophils-lymphocytes rate (NLR), monocytes-lymphocytes rate (MLR), platelets-lymphocytes rate (PLR) and IR, specifically among individuals with T2DM.

METHOD

This study encompassed a cohort of 405 individuals diagnosed with T2DM, comprising cases from January 2021 to November 2022. On the basis of whether there was IR or not, these sufferers were categorized into two cohorts, namely T2DM with IR group (292 cases) and T2DM without IR group (113 cases), as determined by a homeostasis model assessment-IR (HOMA-IR) value exceeding 2.0.

RESULTS

The findings of this study demonstrated compelling evidence of distinct biomarker profiles between individuals with T2DM who had IR and those without IR. Specifically, the IR individuals displayed notably raise NLR, MLR, PLR, C reactive protein (CRP) and serum amyloid A (SAA). Additionally, there was a noticeable decrease in superoxide dismutase (SOD) levels. Furthermore, IR was negatively correlated with SOD values, while positive associations were found between IR and NLR, CRP, and SAA levels (p < 0.05). Moreover, a rise in NLR and PLR levels demonstrated an identical relationship with the prevalence of IR (p = 0.007, p = 0.025, separately). The Receiver operating characteristic (ROC) curve demonstrated that the areas under the curve (AUC) for NLR, MLR, PLR, CRP, SAA and SOD in predicting occurrence of IR in T2DM patients were 0.603, 0.575, 0.581, 0.644, 0.594 and 0.632 respectively, with sensitivity of 79.5%, 95.2%, 46.9%,54.1% (or 51.4), 47.6% (or 45.7%) and 98.6% and specificity of 37.2%, 19.5%, 69.9%, 69% (or 71.7%), 71.6% (or 73.5%) and 23% respectively.

CONCLUSION

Our findings support the notion that higher magnitude of NLR, PLR, MLR, CRP, and SAA values, corresponded to lower SOD levels, indicating a more severe degree of IR in T2DM patients. Additionally, NLR, PLR, MLR, CRP, SAA, and SOD demonstrated predictive potential for assessing IR. Regrettably, due to the retrospective nature of this study, it was not feasible to take a measurement the majority of inflammatory factors and reactive oxygen species (ROS).

Effects of vitamin family members on insulin resistance and diabetes complications

The following letter to the editor highlights the article "Effects of vitamin D supplementation on glucose and lipid metabolism in patients with type 2 diabetes mellitus and risk factors for insulin resistance" in World J Diabetes 2023 Oct 15; 14 (10): 1514-1523. It is necessary to explore the role of vitamin family members in insulin resistance and diabetes complications.