PMID- 32736679 OWN - NLM STAT- MEDLINE DCOM- 20210222 LR - 20211204 IS - 1090-2104 (Electronic) IS - 0006-291X (Linking) VI - 529 IP - 3 DP - 2020 Aug 27 TI - The role of PI3K/Akt/mTOR signaling in dose-dependent biphasic effects of glycine on vascular development. PG - 596-602 LID - S0006-291X(20)31303-6 [pii] LID - 10.1016/j.bbrc.2020.06.085 [doi] AB - Glycine, a non-essential amino acid, exerts concentration-dependent biphasic effects on angiogenesis. Low-doses of glycine promote angiogenesis, whereas high-doses cause anti-angiogenesis. The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling participates in angiogenesis of both physiological development, and pathological events including tumor and inflammation. We assessed the role of PI3K/Akt/mTOR signaling in vascular development, and the interaction with glycine, using transgenic zebrafish Tg(fli1a:Myr-mCherry)(ncv1) embryos expressing fluorescent proteins in vascular endothelial cells. Treatment with inhibitors of mTORC1 (rapamycin and everolimus), mTORC1/mTORC2 (KU0063794), PI3K (LY29400), and Akt (Akt inhibitor) decreased the development of intersegmental vessels (ISVs). These inhibitors cancelled the angiogenic effects of a low-dose of glycine, while acted synergistically with a high-dose of glycine in anti-angiogenesis. mTOR signaling regulates the gene expression of vascular endothelial growth factor (VEGF), a major angiogenic factor, and nitric oxide (NO) synthase (NOS), an enzyme for the synthesis of an angiogenic mediator NO. Expressions of VEGF and NOS were consistent with the vascular features induced by glycine and an mTOR inhibitor. Our results suggest that PI3K/Akt/mTOR signaling may interact with dose-dependent biphasic effects of exogenous glycine on in vivo angiogenesis. mTOR signaling is a key target for cancer therapy, thus, the combining mTOR inhibitors with glycine may be a potential approach for controlling angiogenesis. CI - Copyright (c) 2020 Elsevier Inc. All rights reserved. FAU - Tsuji-Tamura, Kiyomi AU - Tsuji-Tamura K AD - Oral Biochemistry and Molecular Biology, Department of Oral Health Science, Faculty of Dental Medicine and Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo, 060-8586, Japan. Electronic address: ktamuratsuji@den.hokudai.ac.jp. FAU - Sato, Mari AU - Sato M AD - Oral Biochemistry and Molecular Biology, Department of Oral Health Science, Faculty of Dental Medicine and Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo, 060-8586, Japan. FAU - Fujita, Misato AU - Fujita M AD - Department of Biological Sciences, Faculty of Science, Kanagawa University, Hiratsuka, 259-1293, Japan. FAU - Tamura, Masato AU - Tamura M AD - Oral Biochemistry and Molecular Biology, Department of Oral Health Science, Faculty of Dental Medicine and Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo, 060-8586, Japan. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20200717 PL - United States TA - Biochem Biophys Res Commun JT - Biochemical and biophysical research communications JID - 0372516 RN - 0 (Angiogenesis Inhibitors) RN - 0 (Chromones) RN - 0 (Morpholines) RN - 0 (Pyrimidines) RN - 0 (Vascular Endothelial Growth Factor A) RN - 31M2U1DVID (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one) RN - 81HJG228AB (Ku 0063794) RN - 9HW64Q8G6G (Everolimus) RN - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) RN - TE7660XO1C (Glycine) RN - W36ZG6FT64 (Sirolimus) SB - IM MH - Angiogenesis Inhibitors/pharmacology MH - Animals MH - Blood Vessels/*drug effects/embryology MH - Chromones/pharmacology MH - Embryo, Nonmammalian/blood supply/drug effects/embryology MH - Everolimus/pharmacology MH - Gene Expression Regulation, Developmental/drug effects MH - Glycine/*pharmacology MH - Morpholines/pharmacology MH - Phosphatidylinositol 3-Kinases/*metabolism MH - Proto-Oncogene Proteins c-akt/antagonists & inhibitors/*metabolism MH - Pyrimidines/pharmacology MH - Signal Transduction/*drug effects MH - Sirolimus/pharmacology MH - TOR Serine-Threonine Kinases/antagonists & inhibitors/*metabolism MH - Vascular Endothelial Growth Factor A/genetics/metabolism MH - Zebrafish/embryology OTO - NOTNLM OT - Akt OT - Angiogenesis OT - Glycine OT - PI3K OT - Zebrafish OT - mTOR COIS- Declaration of competing interest Embryos obtained from fluorescent transgenic zebrafish line Tg(fli1a:Myr-mCherry)(ncv1) were treated with mTORC1 inhibitors (rapamycin and everolimus) and an mTORC1/mTORC2 dual inhibitor (KU0063794) at 5, 10, and 50 muM concentrations from 9 h post fertilization (hpf). Control embryos were exposed to 0.1% DMSO. The vascular structure in the midtrunk region was observed in embryos at 30 hpf. (A) Representative fluorescent images of vascular structure of embryos treated with each inhibitor (10 muM). Scale bars indicate 100 mum. Similar results were obtained from three independent experiments. DA, dorsal aorta; ISVs, intersegmental vessels; DLAVs, dorsal longitudinal anastomotic vessels. Arrowheads indicate loss of vessel. (B and C) The number (B) and length (C) of ISVs. * Significantly different from DMSO control (p < 0.05). (D) The survival rate of embryos at 24 hpf. The total number of embryos (B and D) or vessels (C) from three independent experiments is presented in the brackets. EDAT- 2020/08/02 06:00 MHDA- 2021/02/23 06:00 CRDT- 2020/08/02 06:00 PHST- 2020/06/12 00:00 [received] PHST- 2020/06/17 00:00 [accepted] PHST- 2020/08/02 06:00 [entrez] PHST- 2020/08/02 06:00 [pubmed] PHST- 2021/02/23 06:00 [medline] AID - S0006-291X(20)31303-6 [pii] AID - 10.1016/j.bbrc.2020.06.085 [doi] PST - ppublish SO - Biochem Biophys Res Commun. 2020 Aug 27;529(3):596-602. doi: 10.1016/j.bbrc.2020.06.085. Epub 2020 Jul 17.