HMBOX1 interacts with MT2A to regulate autophagy and apoptosis in vascular endothelial cells

HanLin Ma; Le Su; HongWei Yue; XiaoLei Yin; Jing Zhao; ShangLi Zhang; HsiangFu Kung; ZhiGang Xu; JunYing Miao

doi:10.1038/srep15121

HMBOX1 interacts with MT2A to regulate autophagy and apoptosis in vascular endothelial cells

Sci Rep. 2015 Oct 12:5:15121. doi: 10.1038/srep15121.

Authors

HanLin Ma¹, Le Su¹, HongWei Yue¹, XiaoLei Yin¹, Jing Zhao¹, ShangLi Zhang¹, HsiangFu Kung^{1

2}, ZhiGang Xu¹, JunYing Miao^{1

3}

Affiliations

¹ Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China.
² Institute of Pathology and Southwest Cancer Center, Third Military Medical University, Chongqing, 400038, China.
³ The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, 250012, China.

Abstract

We previously found that Homeobox containing 1 (HMBOX1) was required for bone mesenchymal stem cell (BMSC) and mouse embryonic stem cell (ESC) differentiation into vascular endothelial cells (VECs). However, the function of HMBOX1 in VECs is still unknown. In this study, we found that HMBOX1 was abundantly expressed in the cytoplasm of human umbilical vascular endothelial cells (HUVECs). Knockdown of HMBOX1 induced apoptosis and inhibited autophagy. Overexpression of HMBOX1 inhibited apoptosis induced by fibroblast growth factor 2 deprivation and promoted autophagy. Metallothionein 2A (MT2A) was identified as an interaction protein with HMBOX1 by yeast two-hybrid assay, and confirmed by co-immunoprecipitation. Overexpression of HMBOX1 elevated intracellular free zinc level. Knockdown of MT2A inhibited this phenomenon. Moreover, N,N,N = ,N = -tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a zinc chelator, reversed the anti-apoptosis and pro-autophagy effects of HMBOX1. In conclusion, HMBOX1 regulated intracellular free zinc level by interacting with MT2A to inhibit apoptosis and promote autophagy in VECs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Apoptosis / drug effects
Apoptosis / genetics
Autophagy / drug effects
Autophagy / genetics
Caspase 3 / genetics
Caspase 3 / metabolism
Ethylamines / pharmacology
Fibroblast Growth Factor 2 / pharmacology
Gene Expression Regulation
HEK293 Cells
Homeodomain Proteins / antagonists & inhibitors
Homeodomain Proteins / genetics*
Homeodomain Proteins / metabolism
Human Umbilical Vein Endothelial Cells / cytology
Human Umbilical Vein Endothelial Cells / drug effects
Human Umbilical Vein Endothelial Cells / metabolism*
Humans
Immunoprecipitation
Metallothionein / antagonists & inhibitors
Metallothionein / genetics*
Metallothionein / metabolism
Pyridines / pharmacology
RNA, Small Interfering / genetics
RNA, Small Interfering / metabolism
Signal Transduction
TOR Serine-Threonine Kinases / genetics
TOR Serine-Threonine Kinases / metabolism
Two-Hybrid System Techniques
Zinc / metabolism*

Substances

Ethylamines
HMBOX1 protein, human
Homeodomain Proteins
MT2A protein, human
N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine
Pyridines
RNA, Small Interfering
Fibroblast Growth Factor 2
Metallothionein
MTOR protein, human
TOR Serine-Threonine Kinases
CASP3 protein, human
Caspase 3
Zinc