Activation of phospholipase C/Ca^<2+> system in thyroid cells and its physiological and pathological roles.

甲状腺细胞磷脂酶C/Ca^2系统的激活及其生理病理作用。

• 批准号: 07457217
• 负责人: OKAJIMA Fumikazu
• 金额: $ 4.16万
• 依托单位: Gunma University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07457217/
• 关键词: Thyroid; Thyrotropin; Calcium Ion; Adenylyl Cyclase; Adenosine; Phospholipase C; Sphingosine 1-phosphate; Basedou's Disease; スフィンゴシン1リン酸; TSH; カルシウムレスポンス; G-タンパク質; 受容体遺伝子; 情報伝達系; cAMPレスポンス; 増殖制御

We have recently found that adenosine inhibits TSH-induced activation of adenylyl cyclase/cAMP system and enhances TSH-induced activation of phospholipase C/Ca^<2+> system in rat thyroid cells. In thyroid cells, in addition to norepinephrine, acetylcholine and ATP,lysosphingolipids such as sphingosine 1-phosphate (SlP) and sphingosylsphosphorylcholine (SPC) has also been suggested to be a potent Ca^<2+> mobilizer. In this study, we planned to clarify the roles of phospholipase C/Ca^<2+> system in thyroid cells. We obtained the following novel findings. (1) In human thyroid cells as well, it was demonstrated that phospholipase C/Ca^<2+> system was regulated through the cross-talk of TSH and adenosine. (2) To clarify the cross-talk mechanism by which TSH and adenosine regulate phospholipase C activity, we used in vivo Cos-7 cell reconstitution system, in which cDNAs encoding receptors, each wild type G-protein subunit and mutant subunit. We found that adenosine-induced modification of two TSH-induced responses were mediated by a single type of Gi protein, Gi2 or Gi3 ; alpha subunit mediates inhibition of AC and betagamma subunits activation of phospholipase C.(3) Grave's IgG in the presence of adenosine induced activation of phospholipase C/Ca^<2+> system, and hence it was suggested that the measurement of phospholipase C/Ca^<2+> system is applied for a novel diagnosis of Grave's disease. (4) SlP and SPC regulated phospholipase C/Ca^<2+> system, H_2O_2 generation, cell proliferation and so on in thyroid cells. Thus, these lipid mediators were suggested to be novel agonists in these cells.

我们最近发现腺苷抑制tsh诱导的大鼠甲状腺细胞腺苷酸环化酶/cAMP系统的激活，并增强tsh诱导的磷脂酶C/Ca^<2+>系统的激活。在甲状腺细胞中，除去甲肾上腺素、乙酰胆碱和ATP外，溶解鞘脂如鞘磷脂1-磷酸（SlP）和鞘磷脂（SPC）也被认为是一种有效的Ca^<2+>动员剂。在本研究中，我们计划阐明磷脂酶C/Ca^<2+>系统在甲状腺细胞中的作用。我们获得了以下新发现。(1)在人甲状腺细胞中，也证实了磷脂酶C/Ca^<2+>系统是通过TSH和腺苷的串扰调节的。(2)为了明确TSH和腺苷调节磷脂酶C活性的串扰机制，我们利用体内Cos-7细胞重构系统，其中cdna编码受体，每种野生型g蛋白亚基和突变亚基。我们发现腺苷诱导的两种tsh诱导反应的修饰是由单一类型的Gi蛋白介导的，Gi2或Gi3；α亚基介导AC和β - γ亚基对磷脂酶C活化的抑制。(3)腺苷存在下Grave's IgG诱导磷脂酶C/Ca^<2+>系统活化，因此建议测定磷脂酶C/Ca^<2+>系统可用于graves病的新诊断。(4) SlP和SPC调节甲状腺细胞磷脂酶C/Ca^<2+>系统、H_2O_2生成、细胞增殖等。因此，这些脂质介质被认为是这些细胞中的新型激动剂。

项目成果

Fumikazu Okajima: "Pertussis toxin inhibits phospholipase C activation and Ca2+ mobilization by sphingosylphosphorylcholine and galactosylsphingosine in HL60 leukemia cells. Implications of GTP-binding protein-coupled receptors for lysosphingolipids." J.B

Fumikazu Okajima：“百日咳毒素抑制 HL60 白血病细胞中磷脂酶 C 的激活以及鞘氨醇磷酸胆碱和半乳糖鞘氨醇对 Ca2+ 的动员。GTP 结合蛋白偶联受体对溶血鞘脂的影响。”

Fumikazu Okajima: "Sphingosine 1-phosphate stimulate hydrogen peroxide generation through activation of phospholipase C-Ca2+ system in FRTL-5 thyroid cells : possible involvement of GTP-binding proteins the lipid singaling." Endocrinology. 138. 220-229 (1

Fumikazu Okajima：“1-磷酸鞘氨醇通过激活 FRTL-5 甲状腺细胞中的磷脂酶 C-Ca2 系统来刺激过氧化氢的产生：GTP 结合蛋白可能参与脂质信号传导。”

Dong-Soon Im: "Chracterization of sphingosine 1-phosphate-induced actions and its signaling pathways in rat hepatocytes." Am.J.Physiol.(in press). (1997)

Dong-Soon Im：“大鼠肝细胞中 1-磷酸鞘氨醇诱导作用及其信号通路的表征。”

T.Kimura: "Thyrotropin-induced hydrogen peroxide production in FRTL-5 thyroid cells is mediated not by adenosine 3',5'-monophosphate,but by Ca2+ signaling followed by phospholipase A2 activation and potentiated by an adenosine derivative." Endocrinology.

T.Kimura：“FRTL-5 甲状腺细胞中促甲状腺素诱导的过氧化氢产生不是由 3,5-单磷酸腺苷介导的，而是由 Ca2 信号传导、随后磷脂酶 A2 激活并由腺苷衍生物增强的。”

Yanagita,Y.: "An adenosine derivative cooperates with TSH and Graves'IgG to induceCa2+ mobilization in single human thyroid cells." Mol.Cell.Endorinol.118. 47-56 (1996)

Yanagita,Y.：“腺苷衍生物与 TSH 和 GravesIgG 协同作用，诱导单个人类甲状腺细胞中的 Ca2 动员。”