Molecular characterization of chloride cells and their mechanism of differentiation

氯细胞的分子特征及其分化机制

• 批准号: 14104002
• 负责人: HIROSE Shigehisa
• 金额: $ 72.55万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (S)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14104002/
• 关键词: chloride cell; Osorezan dace; mitochondria; acid adaptation; channel; transporter; mitochondria-rich cell; foxi3a; V-ATPase; ゼブラフィッシュ; 淡水型塩類細胞; Carbonic anhydrase; Delta-notch; Sodium Green; Na感受性蛍光色素; ミトコンドリア; 細胞内トラフィック; エラ; 柱細胞; pilla

We mainly focused on the chloride cells that are very unique in the structure and function and play key roles in adapting to low or high salt conditions and acidic or alkaline conditions. Our analyses contributed to pushing the forefront of not only osmoregulation of aquatic animals but also fluid homeostasis of the mammalian system. Furthermore mitochondrion-rich nature of chloride cells led us to explore the mitochondrial morphology and to discover a novel regulator of mitochondrial fusion and fission factors. (1) We have clarified the molecular mechanism underlying the acid adaptation of Osorezan dace living in a pH 3.5 lake by identifying molecules associated with gross morphological and functional changes of chloride cells. Increased expression of glutamate dehydrogenase was also observed in various tissues of acid-adapted dace suggesting a significant role of ammonia and bicarbonate generated by glutamine catabolism. (2) We succeeded in visualizing mitochondrion-rich cells (MRCs) … More responsible for uptake of Na^+ in freshwater using a fluorescent dye, Sodium Green. Combined with immunohistochemistry, we revealed that the Na^+-absorbing MRCs were exceptionally rich in vacuolar-type H^+-ATPase (H^+-ATPase) but moderately rich in Na^+/K^+-ATPase. (3) Through molecular, functional, and immunohistochemical characterization of ammonia transporters in fish for the first time, we demonstrated a tight link of ammonia excretion with MRCs and suggested a functional coupling between ion homeostasis and nitrogen metabolism. (4) We also addressed the function of foxi3a, a transcription factor that is specifically expressed in the H^+-ATPase-rich MR cells. When foxi3a was depleted from zebrafish embryos by antisense morpholino oligonucleotide injection, differentiation of the MRCs was completely blocked and Na+ influx was severely reduced, indicating that MRCs are the primary sites for Na^+ absorption. Considering these results with onset of the expression at gastrula stage, we proposed that foxi3a is a key gene for the control of MRC differentiation. The delta-notch signaling system has also been demonstrated to be involved in the differentiation and distribution of MRCs. (5) Mitochondria frequently fuse and divide to form a dynamic network in various eukaryotic cells. We showed that MARCH5 is a mitochondrial outer membrane protein and plays a crucial role in control of mitochondrial morphology by regulating Mfn2 (a fusion factor) and Drp1 (a fission factor) activities. Less

我们主要关注在结构和功能上非常独特的氯细胞，它们在适应低盐或高盐条件和酸性或碱性条件方面起着关键作用。我们的分析不仅推动了水生动物的水调节，而且推动了哺乳动物系统的流体稳态的最前沿。此外，氯细胞的富含钙离子的性质使我们探索线粒体形态，并发现一种新的线粒体融合和分裂因子的调节剂。(1)我们通过鉴定与氯细胞总体形态和功能变化相关的分子，阐明了生活在pH 3.5湖泊中的奥索雷赞鲹鱼酸适应的分子机制。谷氨酸脱氢酶的表达增加，也观察到在各种组织的酸适应的？提示氨和碳酸氢盐产生的谷氨酰胺催化剂的显着作用？(2)我们成功地可视化了富含钙离子的细胞（MRCs） ...更多信息 利用荧光染料钠绿色吸收淡水中的Na^+。结合免疫组化结果，我们发现，Na^+吸收的MRCs异常富含空泡型H^+-ATP酶（H^+-ATP酶），但Na^+/K^+-ATP酶中等丰富。(3)通过分子，功能和免疫组织化学特性的氨转运蛋白在鱼的第一次，我们证明了氨排泄与MRCs的紧密联系，并建议离子稳态和氮代谢之间的功能耦合。(4)我们还研究了foxi 3a的功能，foxi 3a是一种在富含H^+-ATP酶的MR细胞中特异性表达的转录因子。当通过注射反义morpholino寡核苷酸去除斑马鱼胚胎中的foxi 3a时，MRCs的分化被完全阻断，Na+内流严重减少，表明MRCs是Na^+吸收的主要部位。考虑到在原肠胚阶段表达开始的这些结果，我们提出foxi 3a是控制MRC分化的关键基因。delta-notch信号系统也被证明参与了MRC的分化和分布。(5)在各种真核细胞中，线粒体频繁地融合和分裂以形成动态网络。我们发现MARCH 5是一种线粒体外膜蛋白，通过调节Mfn 2（融合因子）和Drp 1（裂变因子）的活性在控制线粒体形态中起着至关重要的作用。少

项目成果

Hirata, T. et al.: "Mechanism of acid adaptation of a fish living in a pH 3.5 lake."Am.J.Physiol.Regulatory Integrative Comp.Physiol.. 284. R1199-R1212 (2003)

Hirata, T. 等人：“生活在 pH 3.5 湖泊中的鱼的酸适应机制。”Am.J.Physiol.Regulatory Integrative Comp.Physiol.. 284. R1199-R1212 (2003)

Inoue K, et al.: "Growth hormone and insulin-like growth factor I of a euryhaline fish Cottus kazika : cDNA cloning and expression after seawater."Gen Comp Endocrinol.. 131(1). 77-84 (2003)

Inoue K 等人：“广盐鱼 Cottus kazika 的生长激素和胰岛素样生长因子 I：海水后的 cDNA 克隆和表达。”Gen Comp Endocrinol.. 131(1)。

Hirose, S. et al.: "Natriuretic peptide receptors in the eel"Camp. Biochem. Physiol.. 134A. S45-S46 (2002)

Hirose, S. 等人：“鳗鱼中的钠尿肽受体”Camp。

Takei, Y., Hirose, S.: "The natriuretic peptide system in eels : a key endocrine system for euryhalinity?"Am. J. Physiol.. 282(4). R940-R951 (2002)

Takei, Y., Hirose, S.：“鳗鱼中的利钠肽系统：广盐性的关键内分泌系统？”Am。

(2007) Visualization in zebrafish larvae of Na^+ uptake in mitochondria-rich cells whose differentiation is dependent on foxi3a

(2007) 斑马鱼幼虫富含线粒体的细胞中 Na^ 吸收的可视化，其分化依赖于foxi3a

• 发表时间: 2007
• 期刊: Am.J.Physiol. 292
• 作者: Esaki;M.;Hoshijima;K.;Kobayashi;S.;Fukuda;H.;Kawakami;K.;Hirose;S.
• 通讯作者: S.