Effects of a GSK-3β inhibitor on the renal expression levels of RANK, RANKL and NF-κB in a rat model of diabetic nephropathy

A case of minimal change disease after the administration of anti receptor activator of nuclear factor kappa B ligand (RANKL) monoclonal antibody: a case report

BACKGROUND

Minimal change disease (MCD) is one of the causes of idiopathic nephrotic syndrome in adults. The pathogenesis of proteinuria in MCD has not been fully understood. Recently, it has been reported that the receptor activator of nuclear factor-kappa B (RANK)/RANK ligand (RANKL) may contribute to the podocyte biology in kidney diseases. Denosumab is a human anti-RANKL monoclonal antibody used to treat osteoporosis. Here we report a case of MCD after denosumab administration.

CASE PRESENTATION

A 59-year-old male without any episodes of proteinuria was given denosumab to treat osteoporosis. Two weeks after its administration, he noticed a foamy urine and bilateral pretibial edema. Laboratory tests revealed that he had severe proteinuria (15g/g Cr), hypoproteinemia (4.0g/dL), and hypoalbuminemia (1.5g/dL). Based on the results, he was diagnosed with nephrotic syndrome. The proteinuria selectivity index was 0.05, indicating selective proteinuria. Renal biopsy showed minor glomerular abnormality with less tubulointerstitial damage, and electron microscopy showed extensive foot process effacement, indicating MCD. With all these results, glucocorticoid therapy of 50mg/day prednisolone was started. After 4weeks of treatment, the urinary protein level remains high (3.1g/g Cr). Prednisolone therapy was continued, and the levels of proteinuria decreased gradually to the range of partial remission (1.2g/g Cr) with another 7weeks of prednisolone treatment, but complete remission was not achieved.

CONCLUSIONS

This might be a case wherein RANKL inhibition is associated with the pathogenesis of MCD. Further studies will be needed to elucidate the causal relationship of RANK-RANKL signaling to the pathogenesis of MCD.

[Lithium chloride arrests HK-2 cell cycle in G2 phase through AKT/GSK-3β signal pathway]

OBJECTIVE

To investigate the effect of lithium chloride (LiCl) on cell cycle of HK-2 cells and explore the possible pathways involved.

METHODS

HK-2 cells were treated with LiCl at different concentrations (5, 12.5, 20, and 25 mmol/L) for 12, 24, 48, or 72 h, and the changes in cell cycle and viability were detected using flow cytometry and CCK-8 assay, respectively. Western blotting was used to analyze the changes in the expressions of cyclin B1 and CDK1 (the two G2 phase-related proteins) and those of AKT/GSK-3β signaling pathway-related proteins in the treated cells.

RESULTS

LiCl treatment time- and concentration-dependently increased HK-2 cell percentage in G2 phase and decreased the cell vitality. The expressions of cyclin B1, CDK1, p-GSK-3β, and β-catenin increased and the expression of p-AKT decreased significantly in the cells as LiCl treatment time and concentration increased.

CONCLUSION

LiCl may cause HK-2 cell cycle arrest in G2 phase through activation of the AKT/GSK-3β signaling pathway.

[Lithium chloride arrests HK-2 cell cycle in G2 phase through AKT/GSK-3β signal pathway]

OBJECTIVE

To investigate the effect of lithium chloride (LiCl) on cell cycle of HK-2 cells and explore the possible pathways involved.

METHODS

HK-2 cells were treated with LiCl at different concentrations (5, 12.5, 20, and 25 mmol/L) for 12, 24, 48, or 72 h, and the changes in cell cycle and viability were detected using flow cytometry and CCK-8 assay, respectively. Western blotting was used to analyze the changes in the expressions of cyclin B1 and CDK1 (the two G2 phase-related proteins) and those of AKT/GSK-3β signaling pathway-related proteins in the treated cells.

RESULTS

LiCl treatment time- and concentration-dependently increased HK-2 cell percentage in G2 phase and decreased the cell vitality. The expressions of cyclin B1, CDK1, p-GSK-3β, and β-catenin increased and the expression of p-AKT decreased significantly in the cells as LiCl treatment time and concentration increased.

CONCLUSION

LiCl may cause HK-2 cell cycle arrest in G2 phase through activation of the AKT/GSK-3β signaling pathway.

Identification of two potential glycogen synthase kinase 3β inhibitors for the treatment of osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor among adolescents worldwide with high mortality rate. Glycogen synthase kinase 3β (GSK3β) is a serine/threonine kinase and is considered as a validated target in osteosarcoma therapy. Therefore, the study of GSK3β inhibitors is one of the most popular fields in anti-osteosarcoma drug development. Here, the tools of bioinformatics were used to screen novel effective inhibitors of GSK3β from ZINC Drug Database. The molecular docking, molecular dynamic simulations, MM/GBSA, and energy decomposition analysis were performed to identify the inhibitors. Finally, ZINC08383479 and ZINC08441251 were selected as potential GSK3β inhibitors. These two inhibitors were evaluated by GSK3β kinase inhibition assay in vitro. The inhibition of cell proliferation was tested in osteosarcoma cell lines U2OS and MG63 in vitro. The result showed that ZINC08383479 and ZINC08441251 had high inhibition activity against GSK3β. We found that CHIR99021 (a known GSK3β inhibitor), ZINC08383479, and ZINC08441251 had significant inhibition activity in U2OS cells and MG63 cells. These findings may provide new ideas for the design of more potent GSK3β inhibitors and therapeutic targets for osteosarcoma.