RESUMO
DICER1 syndrome is a tumor predisposition syndrome caused by familial genetic mutations in DICER1. Pathogenic variants of DICER1 have been discovered in many rare cancers, including cystic liver tumors. However, the molecular mechanisms underlying liver lesions induced by these variants remain unclear. In the present study, we sought to gain a better understanding of the pathogenesis of these variants by generating a mouse model of liver-specific DICER1 syndrome. The mouse model developed bile duct hyperplasia with fibrosis, similar to congenital hepatic fibrosis, as well as cystic liver tumors resembling those in Caroli's syndrome, intrahepatic cholangiocarcinoma, and hepatocellular carcinoma. Interestingly, the mouse model of DICER1 syndrome showed abnormal formation of primary cilia in the bile duct epithelium, which is a known cause of bile duct hyperplasia and cyst formation. These results indicated that DICER1 mutations contribute to cystic liver tumors by inducing defective primary cilia. The mouse model generated in this study will be useful for elucidating the potential mechanisms of tumorigenesis induced by DICER1 variants and for obtaining a comprehensive understanding of DICER1 syndrome. © 2024 The Pathological Society of Great Britain and Ireland.
Assuntos
Cílios , RNA Helicases DEAD-box , Modelos Animais de Doenças , Neoplasias Hepáticas , Ribonuclease III , Animais , Ribonuclease III/genética , Ribonuclease III/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/deficiência , Cílios/patologia , Cílios/metabolismo , Camundongos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Mutação , Fígado/patologia , Fígado/metabolismo , Ductos Biliares/patologiaRESUMO
BACKGROUND: Previous studies showed that microRNA-29b (miR-29b) inhibits renal fibrosis. Therefore, miR-29b replacement therapy represents a promising approach for treating renal fibrosis. However, an efficient method of kidney-targeted miRNA delivery has yet to be established. Recombinant adeno-associated virus (rAAV) vectors have great potential for clinical application. For kidney-targeted gene delivery, the most suitable AAV serotype has yet to be established. Here, we identified the most suitable AAV serotype for kidney-targeted gene delivery and determined that AAV-mediated miR-29b delivery can suppress renal fibrosis in vivo. METHOD: To determine which AAV serotype is suitable for kidney cells, GFP-positive cells were identified by flow cytometry after the infection of rAAV serotype 1-9 vectors containing the EGFP gene. Next, we injected rAAV vectors into the renal pelvis to determine transduction efficiency in vivo. GFP expression was measured seven days after injecting rAAV serotype 1-9 vectors carrying the EGFP gene. Finally, we investigated whether rAAV6-mediated miR-29b delivery can suppress renal fibrosis in UUO mouse model. RESULTS: We found that rAAV6 vector is the most suitable for targeting kidney cells regardless of animal species in vitro and rAAV6 is the most suitable vector for kidney-targeted in vivo gene delivery in mice. Intra-renal pelvic injection of rAAV vectors can transduce genes into kidney TECs. Furthermore, rAAV6-mediated miR-29b delivery attenuated renal fibrosis in UUO model by suppressing Snail1 expression. CONCLUSION: Our study has revealed that rAAV6 is the most suitable serotype for kidney-targeted gene delivery and rAAV6-mediated miR-29b delivery into kidney TECs can suppress established renal fibrosis.