Unraveling DDIT4 in the VDR-mTOR pathway: a novel target for drug discovery in diabetic kidney disease.

Introduction: Diabetic kidney disease (DKD) necessitates innovative therapeutic strategies. This study delves into the role of DNA damage-inducing transcription factor 4 (DDIT4) within the VDR-mTOR pathway, aiming to identify a novel target for DKD drug discovery. Methods: Transcriptome data from the Gene Expression Omnibus Database were analyzed to assess the expression of mTOR and VDR expression in human renal tissues. Clinical samples from DKD patients and minimal change disease (MCD) controls were examined, and a DKD animal model using 20-week-old db/db mice was established. DDIT4 plasmid transfection was employed to modulate the VDR-mTOR pathway, with its components evaluated using immunohistochemistry, real-time quantitative PCR (qRT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). Results: Changes in the expression of the VDR-mTOR pathway were observed in both DKD patients and the animal model. Overexpression of DDIT4 increased VDR expression and decreased levels of mTOR, p70s6k, and 4E-BP1. Furthermore, DDIT4 treatment regulated autophagy by upregulating LC3I expression and downregulating LC3II expression. Notably, DDIT4 alleviated oxidative stress by reducing the levels of lipid peroxidation product MDA, while simultaneously increasing the levels of superoxide dismutase (SOD) and glutathione (GSH), underscoring the role of DDIT4 in the pathological process of DKD and its potential as a therapeutic target. Conclusion: Unraveling DDIT4's involvement in the VDR-mTOR pathway provides insights for innovative DKD drug discovery, emphasizing its potential as a therapeutic target for future interventions.

Optimal assessment of the glomerular filtration rate in older chinese patients using the equations of the Berlin Initiative Study.

AIM: To evaluate the performances of the various estimated glomerular filtration rate (eGFR) equations of the Chronic Kidney Disease Epidemiology Collaboration, the Berlin Initiative Study (BIS), and the Full Age Spectrum (FAS) in older Chinese. METHODS: This study enrolled Chinese adults aged ≥ 65 years who underwent GFR measurements (via 99Tcm-DTPA renal dynamic imaging) in our hospital from 2011 to 2022. Using the measured glomerular filtration rate (mGFR) as the reference, we derived the bias, precision, accuracy, and consistency of each equation. RESULTS: We enrolled 519 participants, comprising 155 with mGFR ≥ 60 mL/min/1.73 m2 and 364 with mGFR < 60 mL/min/1.73 m2. In the total patients, the BIS equation based on creatinine and cystatin C (BIScr-cys) exhibited the lowest bias [median (95% confidence interval): 1.61 (0.77-2.18)], highest precision [interquartile range 11.82 (10.32-13.70)], highest accuracy (P30: 81.12%), and best consistency (95% limit of agreement: 101.5 mL/min/1.73 m2). In the mGFR ≥ 60 mL/min/1.73 m2 subgroup, the BIScr-cys and FAS equation based on creatinine and cystatin C (FAScr-cys) performed better than the other equations; in the mGFR < 60 mL/min/1.73 m2 subgroup, all equations exhibited relatively large deviations from the mGFR. Of all eight equations, the BIScr-cys performed the best. CONCLUSIONS: Although no equation was fully accurate in the mGFR < 60 mL/min/1.73 m2 subgroup, the BIScr-cys (of the eight equations) assessed the eGFRs of the entire population best. A new equation is urgently required for older Chinese and even East Asians, especially those with moderate-to-severe renal insufficiency.

Neutrophil extracellular trap is an important connection between hemodialysis and acute myocardial infarction.

The incidence of acute myocardial infarction (AMI) in hemodialysis (HD) patients is high and the prognosis is extremely poor. However, the potential connection between HD and AMI, and its regulatory mechanisms remain unclear. In this study, the gene expression profiles of HD (GSE15072) and AMI (GSE66360) were downloaded from the Gene Expression Omnibus database, common differentially expressed genes (DEGs) were obtained using the limma R package, the biological functions were analyzed according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, machine learning was conducted to identify hub genes. Receiver operating characteristic curves and gene set enrichment analyses were used to explore the characters and biological function of hub genes, networks were used for candidate identification of transcription factor (TF), microRNA (miRNA), and drug. After a total of 255 common DEGs were selected, GO and KEGG analyses indicated that neutrophil extracellular trap (NET) may be a potential connection between HD and AMI, LILRB2, S100A12, CYBB, ITGAM, and PPIF were finally identified as hub genes. The area under curve of LILRB2, S100A12, and PPIF was higher than 0.8 in both datasets. Networks show the relationship between hub genes, TF, and miRNA, also the relationship between potential drugs and protein. In conclusion, NETs may be the potential connection between AMI and HD. The potential hub gene, signaling pathways, and drugs provided by this study may contribute to future AMI prevention and intervention in HD patients.

A novel approach to improve the pharmacokinetic properties of 8-chloro-adenosine by the dual combination of lipophilic derivatisation and liposome formulation.

8-Chloro-adenosine (8CA) has shown promise in hematologic and solid tumor models and is in a phase I clinical trial. However, 8CA is intensively metabolized shortly after i.v. administration, with a t(1/2ß) of approximately 1h. Many carriers have failed to encapsulate 8CA efficiently. To improve its pharmacokinetic properties, 8-chloro-adenosine-5'-O-stearate (8CAS), a lipophilic octadecanoyl analogue of 8CA, was synthesized and incorporated into pegylated liposomes. The liposomes, comprising egg phosphatidylcholine, cholesterol and poly (ethylene glycol) 2000-distearoyl phosphatidylethanolamine (PEG-DSPE), had mean diameters of approximately 100 nm and an entrapment efficiency of 69-86%. MTT assays showed that the cytotoxicity of 8CAS and its pegylated liposomes (8CAS-PL) were retained, with IC(50) values of 1.0 µM and 1.9 µM at 72 h on MCF-7 cells, respectively, slightly higher than that of 8CA (0.6 µM). Pharmacokinetic studies in rats after i.v. injection showed that both 8CAS and 8 CAS-PL had increased elimination half-lives (t(1/2), 128.4, 249.2 vs. 74.7 min), decreased clearance rates (Cl, 0.0135, 0.00875 vs. 0.2398 L/min/kg) and increased area under the concentration-time curve (AUC(0-∞), 741.4, 1163.6 vs. 42.0 mg min/L) compared to 8CA. No obvious hematological toxicity was seen for Kunming mice receiving i.v. 8CA or 8CAS-PL at a dosage of 10mg/kg daily. These results indicate that the lipophilic derivation of 8CA and the incorporation of 8CAS is an effective strategy to improve the bioavailability of 8CA.

Separation and enrichment of trace ractopamine in biological samples by uniformly-sized molecularly imprinted polymers.

In order to prepare a high capacity packing material for solid-phase extraction with specific recognition ability of trace ractopamine in biological samples, uniformly-sized, molecularly imprinted polymers (MIPs) were prepared by a multi-step swelling and polymerization method using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and toluene as a porogen respectively. Scanning electron microscope and specific surface area were employed to identify the characteristics of MIPs. Ultraviolet spectroscopy, Fourier transform infrared spectroscopy, Scatchard analysis and kinetic study were performed to interpret the specific recognition ability and the binding process of MIPs. The results showed that, compared with other reports, MIPs synthetized in this study showed high adsorption capacity besides specific recognition ability. The adsorption capacity of MIPs was 0.063 mmol/g at 1 mmol/L ractopamine concentration with the distribution coefficient 1.70. The resulting MIPs could be used as solid-phase extraction materials for separation and enrichment of trace ractopamine in biological samples.