Transcription profiling of inner ears from Pou4f3ddl/ddl identifies Gfi1 as a target of the Pou4f3 deafness gene
Transcription profiling of inner ears from Pou4f3ddl/ddl identifies Gfi1 as a target of the Pou4f3 deafness gene
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DOI：
10.1093/hmg/ddh218
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发表时间：
2004-09-15
影响因子：
3.5
通讯作者：
Avraham, KB
中科院分区：
文献类型：
--
作者：
Hertzano, R;Montcouquiol, M;Avraham, KB
Pou 4f 3（Brn3.1，Brn 3c）是IV类POU结构域转录因子，其在人和小鼠内耳感觉上皮中的所有毛细胞的发育中具有中心功能。POU 4F 3突变是人类常染色体显性非综合征性进行性听力损失DFNA 15的基础。通过使用高密度寡核苷酸芯片比较E16.5野生型和Pou 4f 3突变型耳聋小鼠的内耳基因表达谱，我们确定了编码生长因子独立性1（Gfi 1）的基因可能是Pou 4f 3调控的体内靶基因。为了验证这一结果，我们进行了半定量RT-PCR和原位杂交野生型和Pou 4f 3突变小鼠的Gfi 1。我们的研究结果表明，Pou 4f 3的缺陷导致Gfi 1表达水平的统计学显着降低，Gfi 1 mRNA丰度的动态密切遵循Pou 4f 3的表达模式。为了研究Gfi 1在Pou 4f 3相关耳聋发病机制中的作用，我们使用免疫组织化学和扫描电子显微镜对Pou 4f 3和Gfi 1突变小鼠的胚胎内耳进行了比较分析。Gfi 1的缺失导致外毛细胞变性，这似乎与Pou 4f 3突变体中观察到的情况相当。这些结果鉴定Gfi 1作为毛细胞特异性转录因子的第一下游靶标，并表明Pou 4f 3突变体中的外毛细胞变性主要或完全是Gfi 1表达丧失的结果。
Pou4f3 (Brn3.1, Brn3c) is a class IV POU domain transcription factor that has a central function in the development of all hair cells in the human and mouse inner ear sensory epithelia. A mutation of POU4F3 underlies human autosomal dominant non-syndromic progressive hearing loss DFNA15. Through a comparison of inner ear gene expression profiles of E16.5 wild-type and Pou4f3 mutant deaf mice using a high density oligonucleotide microarray, we identified the gene encoding growth factor independence 1 (Gfi1) as a likely in vivo target gene regulated by Pou4f3. To validate this result, we performed semi-quantitative RT-PCR and in situ hybridizations for Gfi1 on wild-type and Pou4f3 mutant mice. Our results demonstrate that a deficiency of Pou4f3 leads to a statistically significant reduction in Gfi1 expression levels and that the dynamics of Gfi1 mRNA abundance closely follow the pattern of expression for Pou4f3. To examine the role of Gfi1 in the pathogenesis of Pou4f3-related deafness, we performed comparative analyses of the embryonic inner ears of Pou4f3 and Gfi1 mouse mutants using immunohistochemistry and scanning electron microscopy. The loss of Gfi1 results in outer hair cell degeneration, which appears comparable to that observed in Pou4f3 mutants. These results identify Gfi1 as the first downstream target of a hair cell specific transcription factor and suggest that outer hair cell degeneration in Pou4f3 mutants is largely or entirely a result of the loss of expression of Gfi1.