Liang Shiting, Wang Youliang, Kang Meixia, Deng Juan, Chen Liting, Hong Xizhen, Hou Fan Fan, Zhang Fujian
Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou, China.
Front Cell Dev Biol. 2023 May 5;11:1171637. doi: 10.3389/fcell.2023.1171637. eCollection 2023.
Protein reabsorption in renal proximal tubules is essential for maintaining nutrient homeostasis. Renal proximal tubule-specific gene knockout is a powerful method to assess the function of genes involved in renal proximal tubule protein reabsorption. However, the lack of inducible renal proximal tubule-specific Cre recombinase-expressing mouse strains hinders the study of gene function in renal proximal tubules. To facilitate the functional study of genes in renal proximal tubules, we developed an knock-in mouse strain expressing a Cre recombinase-estrogen receptor fusion protein under the control of the promoter of the gene, a protein reabsorption receptor in renal proximal tubules. knock-in mice were generated using the CRISPR/Cas9 strategy, and the tissue specificity of Cre activity was investigated using the Cre/loxP reporter system. We showed that the expression pattern of CreERT2-mEGFP in mice was consistent with that of the endogenous gene. Furthermore, we showed that the Cre activity in knock-in mice was only detected in renal proximal tubules with high tamoxifen induction efficiency. As a proof-of-principle study, we demonstrated that renal proximal tubule-specific knockout of using AMN led to albumin accumulation in renal proximal tubular epithelial cells. The mouse is a powerful tool for conditional gene knockout in renal proximal tubules and should offer useful insight into the physiological function of genes expressed in renal proximal tubules.
肾近端小管中的蛋白质重吸收对于维持营养物质稳态至关重要。肾近端小管特异性基因敲除是评估参与肾近端小管蛋白质重吸收的基因功能的有力方法。然而,缺乏可诱导的表达肾近端小管特异性Cre重组酶的小鼠品系阻碍了对肾近端小管中基因功能的研究。为了促进对肾近端小管中基因的功能研究,我们构建了一种敲入小鼠品系,该品系在肾近端小管中的一种蛋白质重吸收受体基因的启动子控制下表达Cre重组酶-雌激素受体融合蛋白。使用CRISPR/Cas9策略生成了敲入小鼠,并使用Cre/loxP报告系统研究了Cre活性的组织特异性。我们发现CreERT2-mEGFP在敲入小鼠中的表达模式与内源性基因的表达模式一致。此外,我们发现只有在高剂量他莫昔芬诱导下,敲入小鼠的肾近端小管中才能检测到Cre活性。作为一项原理验证研究,我们证明使用AMN对进行肾近端小管特异性敲除会导致肾近端小管上皮细胞中白蛋白积累。该敲入小鼠是在肾近端小管中进行条件性基因敲除的有力工具,应该能够为肾近端小管中表达的基因的生理功能提供有用的见解。