State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Zhejiang University City College, Hangzhou, China.
State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
J Adv Res. 2024 Apr;58:129-138. doi: 10.1016/j.jare.2023.06.001. Epub 2023 Jun 14.
As one of the common psychiatric diseases, depression poses serious threats to human health. Although many genes have been nominated for depression, few of them were investigated in details at the molecular level.
To demonstrate Frizzled class receptor 6 (FZD6) functions in depression through disrupting Wnt/β-catenin signal pathway.
The FZD6 edited cell line and mouse model were generated by using CRISPR/Cas9 technique. The expression of key genes and proteins in Wnt/β-catenin pathway was determined by qRT-PCR and Western blotting, respectively. Animal behavioral tests, including open field test (OFT), elevated plus maze test (EPM), forced swimming test (FST), tail suspension test (TST), and sucrose preference test (SPT), were employed to determine anxiety- and depressive-like behaviors. Immunofluorescent staining was used to assess cell proliferation in the hippocampus of mouse brain.
Among patients with depression, FZD6, one of the receptors of Wnt ligand, was significantly decreased. In CRISPR/Cas9-based FZD6 knockdown cells, we showed that FZD6 plays a significant role in regulating expression of genes involved in Wnt/β-catenin pathway. Subsequently behavioral studies on Fzd6 knockdown mice (with a 5-nucleotide deletion; Fzd6-Δ5) revealed significant changes in depressive symptoms, including increased immobility duration in FST, less preference of sucrose in SPT, reduction of distance traveled in OFT, and decreased time spent in open arms in EPM. Immunofluorescent staining showed decreased cell proliferation in the hippocampus of Fzd6-Δ5 mice with reduced number of Ki67 and PCNA cells. Moreover, decreased Gsk3β mRNA expression, phosphorylated GSK3β, and cytoplasmic β-catenin in the hippocampus of Fzd6-Δ5 mice provided further evidence supporting the role of Fzd6 in depression.
Together, above findings proved the significant role of FZD6 in depression through its effect on hippocampal cell proliferation and its ability to regulate canonical Wnt/β-catenin pathway.
抑郁症作为一种常见的精神疾病，严重威胁着人类的健康。虽然已经有许多基因被提名用于抑郁症，但其中很少有基因在分子水平上进行详细研究。
通过破坏 Wnt/β-catenin 信号通路来证明卷曲受体 6（FZD6）在抑郁症中的作用。
利用 CRISPR/Cas9 技术构建 FZD6 编辑细胞系和小鼠模型。采用 qRT-PCR 和 Western blot 分别检测 Wnt/β-catenin 通路中关键基因和蛋白的表达。采用旷场实验（OFT）、高架十字迷宫实验（EPM）、强迫游泳实验（FST）、悬尾实验（TST）和蔗糖偏好实验（SPT）等动物行为学实验检测焦虑和抑郁样行为。免疫荧光染色检测小鼠大脑海马区细胞增殖情况。
在抑郁症患者中，Wnt 配体的受体之一 FZD6 显著降低。在基于 CRISPR/Cas9 的 FZD6 敲低细胞中，我们表明 FZD6 在调节 Wnt/β-catenin 通路相关基因的表达中起着重要作用。随后对 Fzd6 敲低小鼠（发生 5 个核苷酸缺失；Fzd6-Δ5）进行行为学研究表明，Fzd6 缺失导致抑郁症状发生显著变化，包括 FST 中不动时间延长、SPT 中蔗糖偏好减少、OFT 中移动距离减少和 EPM 中开放臂时间减少。免疫荧光染色显示 Fzd6-Δ5 小鼠海马区细胞增殖减少，Ki67 和 PCNA 细胞数量减少。此外，Fzd6-Δ5 小鼠海马区 Gsk3β mRNA 表达减少、磷酸化 GSK3β 和细胞质 β-catenin 减少进一步证实了 Fzd6 在抑郁症中的作用。
综上所述，FZD6 通过影响海马区细胞增殖和调节经典 Wnt/β-catenin 通路，在抑郁症中发挥重要作用。
