Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia
Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia
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DOI：
10.1152/ajpregu.00168.2015
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发表时间：
2015-11-15
影响因子：
2.8
通讯作者：
Seale, Andre P.
中科院分区：
文献类型：
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作者：
Inokuchi, Mayu;Breves, Jason P.;Seale, Andre P.
本研究研究了细胞外渗透压和催乳素（PRL）对莫桑比克罗非鱼鳃离子调节功能的局部影响。首先，从淡水（FW）驯化的罗非鱼身上解剖出鳃丝，并在四种不同的渗透压（280、330、380和450 mosmol/kg H2O）下孵育。随着介质渗透压的降低，Na+/K+ - atp酶α 1a （NKA α 1a）和Na+/Cl-共转运体（NCC） mRNA表达量增加，Na+/K+/2Cl（-）共转运体1a （NKCC1a）和PRL受体2 (PRLR2) mRNA表达量上调。然后，我们将鳃丝在含有绵羊PRL（oPRL）和本地罗非鱼PRL（tPRL（177）和tPRL(188)）的培养基中孵育。oPRL和两种天然tprl对NCC、NKA α 1a和PRLR1的表达呈浓度依赖性；与tPRLs孵育24 H后，Na+/H+交换物3 （NHE3）表达增加。免疫组化观察显示，oPRL和两种tprl在培养的纤维中保持了高密度的NCC-和nka免疫反应性离子细胞。此外，我们发现tPRL177和tPRL188诱导这些离子转运体表达的差异取决于孵育时间。总之，这些结果提供了证据，证明莫桑比克罗非鱼的离子细胞可能作为渗透受体，并直接响应PRL调节鳃离子调节功能。
This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia (Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na+/K+ -ATPase alpha 1a (NKA alpha 1a) and Na+/Cl- cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na+/K+/2Cl(-) cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL(177) and tPRL(188)). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKA alpha 1a, and PRLR1 expression; Na+/H+ exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.