Embryonic stem cells derived kidney organoids as faithful models to target programmed nephrogenesis

Abstract The kidney is a complex organ that is comprised of thousands of nephrons developing through reciprocal inductive interactions between metanephric mesenchyme (MM) and ureteric bud (UB). The MM undergoes mesenchymal to epithelial transition (MET) in response to the signaling from the UB. The secreted protein Wnt4, one of the Wnt family members, is critical for nephrogenesis as mouse Wnt4−/− mutants fail to form pretubular aggregates (PTA) and therefore lack functional nephrons. Here, we generated mouse embryonic stem cell (mESC) line lacking Wnt4 by applying the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated systems 9 (Cas9). We describe here, differentiation of the wild type and Wnt4 knockout mESCs into kidney progenitors, and such cells induced to undergo nephrogenesis by the mouse E11.5 UB mediated induction. The wild type three-dimensional (3D) self-organized organoids depict appropriately segmented nephron structures, while the Wnt4-deficient organoids fail to undergo the MET, as is the case in the phenotype of the Wnt4 knockout mouse model in vivo. In summary, we have established a platform that combine CRISPR/Cas9 and kidney organoid technologies to model kidney development in vitro and confirmed that mutant organoids are able to present similar actions as in the in vivo studies

Denosumab treatment for aggressive multiple recurrent familial central giant-cell granulomas

Abstract Background: Aggressive familial giant-cell granulomas of the jaws can be severely deforming. Surgical and nonsurgical treatments may be associated with multiple recurrences. Denosumab, a new generation antiresorptive drug, is an osteoclast inhibitor, which may be particularly useful to manage such potentially disfiguring lesions. Materials and Methods: Two sisters, both with a history of multiple recurrent aggressive central giant-cell granuloma (CGCG)-like lesions in both jaws, were referred for management. All lesions were histologically consistent with the diagnosis of CGCG. The lesions were treated surgically with curettage and perilesional injection of triamcinolone. In particular, the older sister had four separate anatomic sites where some of her lesions had multiple recurrences necessitating three repeat procedures. A course of subcutaneous denosumab was administered following the last giant-cell granuloma removal in both sisters. Results: Bony healing was normal. No further recurrences were observed over 3.5 years of follow-up after denosumab therapy in either sister. Conclusions: In this small cohort comprising two sisters with multiple aggressive recurrent giant-cell granuloma lesions at multiple sites in the mouth, subcutaneous denosumab administration was associated with success over 3.5 years of follow-up. This report cautiously adds to the clinical experience in the use of denosumab for the treatment of recurrent aggressive familial CGCG lesions