Vitamin D resistant genes - promising therapeutic targets of chronic diseases

Integrated analysis of blood DNA methylation, genetic variants, circulating proteins, microRNAs, and kidney failure in type 1 diabetes

Variation in DNA methylation (DNAmet) in white blood cells and other cells/tissues has been implicated in the etiology of progressive diabetic kidney disease (DKD). However, the specific mechanisms linking DNAmet variation in blood cells with risk of kidney failure (KF) and utility of measuring blood cell DNAmet in personalized medicine are not clear. We measured blood cell DNAmet in 277 individuals with type 1 diabetes and DKD using Illumina EPIC arrays; 51% of the cohort developed KF during 7 to 20 years of follow-up. Our epigenome-wide analysis identified DNAmet at 17 CpGs (5'-cytosine-phosphate-guanine-3' loci) associated with risk of KF independent of major clinical risk factors. DNAmet at these KF-associated CpGs remained stable over a median period of 4.7 years. Furthermore, DNAmet variations at seven KF-associated CpGs were strongly associated with multiple genetic variants at seven genomic regions, suggesting a strong genetic influence on DNAmet. The effects of DNAmet variations at the KF-associated CpGs on risk of KF were partially mediated by multiple KF-associated circulating proteins and KF-associated circulating miRNAs. A prediction model for risk of KF was developed by adding blood cell DNAmet at eight selected KF-associated CpGs to the clinical model. This updated model significantly improved prediction performance (c-statistic = 0.93) versus the clinical model (c-statistic = 0.85) at P = 6.62 × 10-14. In conclusion, our multiomics study provides insights into mechanisms through which variation of DNAmet may affect KF development and shows that blood cell DNAmet at certain CpGs can improve risk prediction for KF in T1D.

Exploring Lactoferrin as a novel marker for disease pathology and ferroptosis regulation in gestational diabetes

Iron overload is linked to heightened susceptibility to ferroptosis, a process increasingly implicated in diabetes pathogenesis. This present study aims to assess the utility of Lactoferrin in predicting different stages of GDM and explore its association with disease pathology and ferroptosis. In this observational study, 72 pregnant women were recruited and categorized into three groups: healthy pregnant women without diabetes (NGDM, n = 24), early gestational diabetes (eGDM, n = 24), and established gestational diabetes (GDM, n = 24), all receiving standard antenatal care at 12 weeks of gestation. Circulating levels of ferritin, soluble transferrin receptor (sTFR), and Lactoferrin using multiplexed bead-based cytokine immunoassay. Gene expression analysis focused on analyzing crucial ferroptosis regulators, SLC7A11 and GPX4, in isolated peripheral blood mononuclear cells (PBMCs). A significant elevation in ferritin levels and a decrease in the sTFR: Ferritin ratio supported iron overload and disrupted iron homeostasis in GDM subjects. Notably, Lactoferrin levels were significantly lower in women with GDM than in the control group and those with eGDM. This decline in Lactoferrin correlated with increased hyperglycemia indicators and reduced expression of ferroptosis regulators among GDM patients. Furthermore ROC curve analysis demonstrated that Lactoferrin shows promise as a valuable marker for distinguishing individuals with GDM from those with eGDM. Lactoferrin shows promise as a biomarker for detecting GDM. These findings indicate its role as a potential biomarker and highlight Lactoferrin as a critical regulator of hyperglycemia and ferroptosis in women with GDM.

Transcriptomics and systems network-based molecular mechanism of herbal formula Huosu-Yangwei inhibited gastric cancer in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

The efficacy of the herbal formula Huosu-Yangwei (HSYW) in the treatment of advanced gastric cancer and chronic atrophic gastritis with precancerous lesions has been reported in clinical trials. However, the molecular mechanisms underlying its inhibition of gastric tumor are not well-understood.

AIM OF THE STUDY

Combined with transcriptomics and systems network-based molecular mechanism to explore the potential circRNA-miRNA-mRNA network of HSYW in the treatment of gastric cancer.

MATERIALS AND METHODS

Animal experiments were conducted to investigate the effect of HSYW on tumor growth in vivo. RNA sequencing (RNA-seq) was implemented to identify the differentially expressed (DE) genes. Predictive miRNA targets and mRNA were used to construct circRNA-miRNA-mRNA networks and protein-protein interaction (PPI) networks. Quantitative real-time PCR (qRT-PCR) was utilized to verify the accuracy of the proposed circRNA-miRNA-mRNA networks. Additionally, the differentially expressed target proteins between gastric cancer (GC) and normal patients were assessed using data from the TCGA (The Cancer Genome Atlas) and HPA (The Human Protein Atlas) databases.

RESULTS

We demonstrate HSYW significantly inhibits tumor growth of N87 cell-bearing Balb/c mice. Transcriptomic analysis revealed the existence of 119 differentially expressed (DE) circRNAs and 200 DE mRNAs between HSYW-treated and model mice. By associating predicted circRNA-miRNA pairs and miRNA-mRNA pairs, we constructed a circRNA-miRNA-mRNA (CMM) network. Furthermore, a protein-protein interaction (PPI) network was developed using the differential expressed mRNAs. Consequently, the reconstructed core CMM network and qRT-PCR validation indicated that 4 circRNAs, 5 miRNAs and 6 mRNAs could potentially serve as biomarkers to assess the therapeutic effects of HSYW-treated N87-bearing Balb/c mice. The TCGA and HPA databases also demonstrated that mRNA KLF15 and PREX1 had substantial differences between gastric cancer (GC) and healthy controls.

CONCLUSIONS

By combining the experimental and bioinformatics analysis, this study confirms that the circRNA_00240/hsa-miR-642a-5p/KLF15 and circRNA_07980/hsa-miR-766-3p/PREX1 pathways play critical roles in HSYW-treated gastric cancer.

Causal association between vitamin D and diabetic neuropathy: a Mendelian randomization analysis

OBJECTIVES

Vitamin D has been linked to diabetic neuropathy (DN) in previous epidemiological observational studies, however, their findings are inconsistent. The causal relationship between vitamin D and DN remains unknown. In this study we aim to investigate the causal association of serum 25-hydroxyvitamin D (25OHD) and DN.

METHODS

Based on summary statistics from publicly available genome-wide association studies (GWAS) database, we detected the genetic correlation between serum 25OHD levels and DN by a two-sample Mendelian randomization (MR) analysis. The inverse-variance weighted (IVW) method was used as the primary analysis, weighted median and MR-Egger were applied as complementary methods for MR estimates. In addition, we took sensitivity analyses including Cochran's Q test, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and leave-one-out analysis to ensure that we obtained stable and reliable results.

RESULTS

Our MR study showed no significant genetic association between serum 25OHD levels and DN (OR = 1.13, 95% CI = 0.81-1.57, P = 0.46). Furthermore, in the reverse direction analysis, we did not find a significant causal effect of DN and serum 25OHD levels (OR = 0.99, 95% CI = 0.98-1.00, P = 0.09). Results of MR-Egger, Weighted Median were consistent with those of the IVW method. The sensitivity analysis suggesting that no significant heterogeneity and genetic pleiotropy was observed.

CONCLUSIONS

Our results provided no evidence to support the causal association of serum 25OHD levels with DN.

On the Centennial of Vitamin D-Vitamin D, Inflammation, and Autoimmune Thyroiditis: A Web of Links and Implications

The 100th anniversary of the discovery of vitamin D3 (VitD3) coincides with significant recent advances in understanding its mechanism of action along with accumulating knowledge concerning its genomic and nongenomic activities. A close relationship between VitD3 and the immune system, including both types of immunity, innate and adaptive, has been newly identified, while low levels of VitD3 have been implicated in the development of autoimmune thyroiditis (AIT). Active 1,25(OH)₂ D3 is generated in immune cells via 1-α-hydroxylase, subsequently interacting with the VitD3 receptor to promote transcriptional and epigenomic responses in the same or adjacent cells. Despite considerable progress in deciphering the role of VitD3 in autoimmunity, its exact pathogenetic involvement remains to be elucidated. Finally, in the era of coronavirus disease 2019 (COVID-19), brief mention is made of the possible links between VitD3 deficiency and risks for severe COVID-19 disease. This review aims to commemorate the centennial of the discovery of VitD3 by updating our understanding of this important nutrient and by drawing up a framework of guidance for VitD3 supplementation, while emphasizing the necessity for personalized treatment in patients with autoimmune thyroid disease. A tailored approach based on the specific mechanisms underlying VitD3 deficiency in different diseases is recommended.