Renal structural changes in non-insulin-dependent diabetes mellitus

Identifying the Potential Diagnostic Gene Biomarkers and Forecasting the Potential Therapeutic Agents for Advanced Diabetic Nephropathy Based on Pyroptosis and Ferroptosis

Background

Diabetic nephropathy (DN) is a prevalent complication of diabetes, often leading to end-stage kidney disease (ESKD). Advanced DN progresses to ESKD rapidly, yet effective diagnostic indicators and treatments are lacking.

Methods

Two DN-related datasets were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the R packages. Pyroptosis-related genes (PRGs) and ferroptosis-related genes (FRGs) were collected from their respective database. Pyroptosis- and ferroptosis-related differentially expressed genes (PFRDEGs) were identified by overlapping DEGs, PRGs, and FRGs for further analysis, including functional enrichment and immune infiltration. Hub genes were identified using a PPI network via MCODE-plugin in Cytoscape. GeneMANIA was utilized to explore intermolecular interactions among hub genes. Based on these hub genes, a diagnostic model was constructed using the receiver operating characteristic curve and potential therapeutic agents were retrieved. Correlation analysis between hub genes and estimated glomerular filtration rate was performed using Nephroseq v5 database, and expression of hub genes was validated in external GEO database, Nephroseq v5 database and DN mice in vivo.

Results

Four hub genes (CYBB, LCN2, JUN and ADIPOQ) were identified, and three of the four hub genes (CYBB, LCN2 and ADIPOQ) were found to be potential biomarkers for advanced DN. On this basis, three potential therapeutic agents were screened. More importantly, a series of biological experiments confirmed that CYBB and LCN2 were significantly up-regulated in DN mice.

Conclusion

This study identifies three hub genes as diagnostic biomarkers and mines three potential therapeutic agents for advanced DN, providing new insights into the role of pyroptosis and ferroptosis in advanced DN and laying the foundation for future research.

Diagnosis and treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is the most common cause of chronic kidney disease in the United States. In the last several years, there have been several new developments in the field of the DKD. In 2007, the National Kidney Foundation and Kidney Disease Outcomes Quality Initiative released clinical practice guidelines that included new definitions and summarized diagnostic and therapeutic approaches for DKD. The results of several recent randomized controlled trials provided novel insights regarding effects of glycemic and lipid control on vascular and renal outcomes in patients with diabetes. Additionally, the findings of the Action to Control Cardiovascular Risk in Diabetes-Blood Pressure trial played a critical role in the revision of blood pressure target guidelines in patients with diabetes. The goal of this review article is to summarize recent updates and recommendations for the diagnosis and treatment of DKD.

Renal histopathology of a baboon model with type 2 diabetes

Naturally occurring type 2 diabetes has been found in a colony of baboons. Ongoing characterization of the baboon colony maintained at the Southwest National Primate Research Center has revealed a significant range of glucose sensitivity with some animals clearly diabetic.   Seven baboons, four with diabetes and three without diabetes, underwent histopathological investigation. Three diabetic animals were diagnosed using fasting blood glucose, hemoglobin A1C, and intravenous glucose tolerance test, and a fourth one was known to have hyperglycemia. One control baboon and three baboons with diabetes had microalbuminuria. On kidney biopsy, diabetic baboons had thickening of the glomerular basement membrane and mesangial matrix expansion compared to controls. Immunohistochemistry showed the diabetic animals had increased mesangial expression of cellular fibronectin ED-A. Two diabetic animals with microalbuminuria had evidence of mesangiolysis with the formation of an early nodule. One diabetic animal had a Kimmestiel-Wilson nodule. We conclude that the baboon represents a useful primate model of diabetes and nephropathy that resembles the nephropathy associated with type 2 diabetes in humans.

Determinants of coronary artery calcification in diabetics with and without nephropathy

BACKGROUND

In the general population, including those with diabetes mellitus, coronary artery calcification (CAC) correlates with atherosclerotic plaque burden. On the other hand, accumulating evidence suggests that disordered mineral metabolism significantly contributes to the vascular calcification in individuals with end-stage renal disease (ESRD).

METHODS

In order to determine the relative contribution of accelerated atherosclerosis and disordered mineral metabolism to CAC in chronic kidney disease, a pilot study of 90 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30; diabetic nephropathy (DN), N= 60].

RESULTS

CAC was more prevalent and severe among individuals with DN compared to diabetic controls (odds ratio for prevalence 8.1, 95% CI 2.3-28.5; median scores, 66 vs. 4, P < 0.001). None of the 4 measures of disordered mineral metabolism evaluated in this study (serum calcium, phosphorus, parathyroid hormone, and 1,25 di-hydroxy vitamin D levels) correlated with the prevalence or severity of CAC, or accounted for the differences seen between DN and diabetic controls. On the other hand, the difference in the severity of hypertension (number of antihypertensive medications) appeared to account for the differences in CAC burden seen between DN and diabetic controls.

CONCLUSION

This first such study of nondialyzed individuals with DN suggests that, unlike ESRD patients, the high CAC burden seen at earlier stages of diabetic chronic kidney disease is probably unrelated to disordered mineral metabolism. The relationship between the severity of hypertension and CAC burden provides a probable target for intervention in the predialysis phase of DN.