Macrophage ALDH2 (Aldehyde Dehydrogenase 2) Stabilizing Rac2 Is Required for Efferocytosis Internalization and Reduction of Atherosclerosis Development

Jian Zhang; Xiangkai Zhao; Yunyun Guo; Zhiping Liu; Shujian Wei; Qiuhuan Yuan; Haixia Shang; Wentao Sang; Sumei Cui; Tonghui Xu; Kehui Yang; Jialin Guo; Chang Pan; Jiali Wang; Jiaojiao Pang; Tianrui Han; Yuguo Chen; Feng Xu

doi:10.1161/ATVBAHA.121.317204

Macrophage ALDH2 (Aldehyde Dehydrogenase 2) Stabilizing Rac2 Is Required for Efferocytosis Internalization and Reduction of Atherosclerosis Development

Arterioscler Thromb Vasc Biol. 2022 Jun;42(6):700-716. doi: 10.1161/ATVBAHA.121.317204. Epub 2022 Mar 31.

Authors

Jian Zhang^#^{1

2

3

4

5}, Xiangkai Zhao^#^{1

2

3

4

5}, Yunyun Guo^{1

2

3

4

5}, Zhiping Liu⁶, Shujian Wei^{1

2

3

4

5}, Qiuhuan Yuan^{1

3

4

5}, Haixia Shang⁶, Wentao Sang^{1

3

4}, Sumei Cui^{1

2

3

4

5}, Tonghui Xu^{1

2

3

4

5}, Kehui Yang^{1

2

3

4

5}, Jialin Guo^{1

2

3

4

5}, Chang Pan^{1

2

3

4

5}, Jiali Wang^{1

2

3

4

5}, Jiaojiao Pang^{1

2

3

4

5}, Tianrui Han^{1

2

3

4

5}, Yuguo Chen^{1

2

3

4

5}, Feng Xu^{1

2

3

4

5}

Affiliations

¹ Department of Emergency Medicine (J.Z., X.Z., Y.G., S.W., Q.Y., W.S., S.C., T.X., K.Y., J.G., C.P., J.W., J.P., T.H., Y.C., F.X.), Qilu Hospital, Shandong University, Jinan, China.
² Chest Pain Center (J.Z., X.Z., Y.G., S.W., Q.Y., W.S., S.C., T.X., K.Y., J.G., C.P., J.W., J.P., T.H., Y.C., F.X.), Qilu Hospital, Shandong University, Jinan, China.
³ Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine, Institute of Emergency and Critical Care Medicine of Shandong University (J.Z., X.Z., Y.G., S.W., Q.Y., W.S., S.C., T.X., K.Y., J.G., C.P., J.W., J.P., T.H., Y.C., F.X.), Qilu Hospital, Shandong University, Jinan, China.
⁴ Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong Province, Shandong Provincial Engineering Laboratory for Emergency and Critical Care Medicine (J.Z., X.Z., Y.G., S.W., Q.Y., W.S., S.C., T.X., K.Y., J.G., C.P., J.W., J.P., T.H., Y.C., F.X.), Qilu Hospital, Shandong University, Jinan, China.
⁵ The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine (J.Z., X.Z., Y.G., S.W., Q.Y., W.S., S.C., T.X., K.Y., J.G., C.P., J.W., J.P., T.H., Y.C., F.X.), Qilu Hospital, Shandong University, Jinan, China.
⁶ Center of Intelligent Medical Engineering, School of Control Science and Engineering, Shandong University, Jinan, China (Z.L., H.S.).

^# Contributed equally.

Abstract

Background: Clinical studies show that the most common single-point mutation in humans, ALDH2 (aldehyde dehydrogenase 2) rs671 mutation, is a risk factor for the development and poor prognosis of atherosclerotic cardiovascular diseases, but the underlying mechanism remains unclear. Apoptotic cells are phagocytosed and eliminated by macrophage efferocytosis during atherosclerosis, and enhancement of arterial macrophage efferocytosis reduces atherosclerosis development.

Methods: Plaque areas, necrotic core size, apoptosis, and efferocytosis in aortic lesions were investigated in APOE^-/- mice with bone marrow transplanted from APOE^-^/-ALDH2^-^/- and APOE^-^/- mice. RNA-seq, proteomics, and immunoprecipitation experiments were used to screen and validate signaling pathways affected by ALDH2. Efferocytosis and protein levels were verified in human macrophages from wild-type and rs671 mutation populations.

Results: We found that transplanting bone marrow from APOE^-^/-ALDH2^-^/- to APOE^-^/- mice significantly increased atherosclerosis plaques compared with transplanting bone marrow from APOE^-^/- to APOE^-^/- mice. In addition to defective efferocytosis in plaques of APOE^-^/- mice bone marrow transplanted from APOE^-^/-ALDH2^-^/- mice in vivo, macrophages from ALDH2^-^/- mice also showed significantly impaired efferocytotic activity in vitro. Subsequent RNA-seq, proteomics, and immunoprecipitation experiments showed that wild-type ALDH2 directly interacted with Rac2 and attenuated its degradation due to decreasing the K48-linked polyubiquitination of lysine 123 in Rac2, whereas the rs671 mutant markedly destabilized Rac2. Furthermore, Rac2 played a more crucial role than other Rho GTPases in the internalization process in which Rac2 was up-regulated, activated, and clustered into dots. Overexpression of wild-type ALDH2 in ALDH2^-^/- macrophages, rather than the rs671 mutant, rescued Rac2 degradation and defective efferocytosis. More importantly, ALDH2 rs671 in human macrophages dampened the apoptotic cells induced upregulation of Rac2 and subsequent efferocytosis.

Conclusions: Our study has uncovered a pivotal role of the ALDH2-Rac2 axis in mediating efferocytosis during atherosclerosis, highlighting a potential therapeutic strategy in cardiovascular diseases, especially for ALDH2 rs671 mutation carriers.

Keywords: apoptosis; atherosclerosis; macrophage; proteomics.

Publication types

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

MeSH terms

Aldehyde Dehydrogenase, Mitochondrial / genetics
Aldehyde Dehydrogenase, Mitochondrial / metabolism
Animals
Apolipoproteins E / genetics
Apoptosis / physiology
Atherosclerosis* / genetics
Atherosclerosis* / metabolism
Atherosclerosis* / prevention & control
Cardiovascular Diseases* / metabolism
Macrophages / metabolism
Mice
Mice, Inbred C57BL
Mice, Knockout
Plaque, Atherosclerotic* / pathology
RAC2 GTP-Binding Protein
rac GTP-Binding Proteins / metabolism*

Substances

Apolipoproteins E
ALDH2 protein, mouse
Aldehyde Dehydrogenase, Mitochondrial
rac GTP-Binding Proteins