Rab7 GTPase controls lipid metabolic signaling in myeloidderived suppressor cells

Xinchun Ding, Wenjing Zhang, Ting Zhao, Cong Yan, Hong Du

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Lysosomal acid lipase (LAL) is a critical neutral lipid metabolic enzyme that regulates metabolic reprogramming in myeloid-derived suppressor cells (MDSCs) through over-activation of mammalian target of rapamycin (mTOR). Affymetrix GeneChip microarray analysis of MDSCs from LAL deficient mouse (lal-/- ) revealed upregulation of Rab7 GTPase protein, which belongs to a superfamily of smallmolecular- weight GTPase known to regulate intracellular membrane trafficking from early to late endosomes and lysosomes. Here, the physical protein-protein interaction between Rab7 GTPase and mTOR has been detected by co-immunoprecipitation in the cell extract of wild type HD1A and lal-/- MDSC-like HD1B myeloid cell lines. The GST pull down assay using the recombinant GST-Rab7 GTPase fusion protein showed that Rab7 GTPase interacts with the mTOR N-terminal heat repeat domain. Rab7 GTPase siRNA knocking down reversed the altered lysosome/mTOR distribution and expression levels in HD1B cells. Rab7 GTPase siRNA knocking down in isolated bone marrow lal-/- MDSCs or HD1B cells not only reduced over-activation of mTOR and its downstream effector S6, but also decreased glucose consumption, decreased ROS over-production, and increased healthy mitochondria by membrane potential measurement. Inhibition of Rab7 GTPase led to reduced lal-/- MDSCs differentiation from bone marrow Lin- progenitor cells, reduced lal-/- MDSCs trans-endothelial migration, and reversed lal-/- MDSCs suppression of T cell proliferation. Furthermore, inhibition of Rab7 GTPase reduced lal-/- MDSCs ability to stimulate tumor cell proliferation in vitro, tumor growth in vivo, and tumor invasion. Together, these results showed that Rab7 GTPase is critically involved in MDSCs homeostasis and pathogenic functions.

Original languageEnglish (US)
Pages (from-to)30123-30137
Number of pages15
JournalOncotarget
Volume8
Issue number18
DOIs
StatePublished - 2017

Fingerprint

GTP Phosphohydrolases
Lipids
Sirolimus
Lysosomes
Small Interfering RNA
Bone Marrow
Cell Proliferation
Sterol Esterase
Myeloid-Derived Suppressor Cells
S 6
Neoplasms
Intracellular Membranes
Terminal Repeat Sequences
Endosomes
Myeloid Cells
Microarray Analysis
Cell Extracts
Immunoprecipitation
Membrane Potentials
Cell Differentiation

Keywords

  • Lipid metabolism
  • Myeloid-derived suppressor cells
  • Rab7 GTPase
  • Tumor growth

ASJC Scopus subject areas

  • Oncology

Cite this

Rab7 GTPase controls lipid metabolic signaling in myeloidderived suppressor cells. / Ding, Xinchun; Zhang, Wenjing; Zhao, Ting; Yan, Cong; Du, Hong.

In: Oncotarget, Vol. 8, No. 18, 2017, p. 30123-30137.

Research output: Contribution to journalArticle

Ding, Xinchun ; Zhang, Wenjing ; Zhao, Ting ; Yan, Cong ; Du, Hong. / Rab7 GTPase controls lipid metabolic signaling in myeloidderived suppressor cells. In: Oncotarget. 2017 ; Vol. 8, No. 18. pp. 30123-30137.
@article{fc36c49db15f4bceaf49ff43a56279a9,
title = "Rab7 GTPase controls lipid metabolic signaling in myeloidderived suppressor cells",
abstract = "Lysosomal acid lipase (LAL) is a critical neutral lipid metabolic enzyme that regulates metabolic reprogramming in myeloid-derived suppressor cells (MDSCs) through over-activation of mammalian target of rapamycin (mTOR). Affymetrix GeneChip microarray analysis of MDSCs from LAL deficient mouse (lal-/- ) revealed upregulation of Rab7 GTPase protein, which belongs to a superfamily of smallmolecular- weight GTPase known to regulate intracellular membrane trafficking from early to late endosomes and lysosomes. Here, the physical protein-protein interaction between Rab7 GTPase and mTOR has been detected by co-immunoprecipitation in the cell extract of wild type HD1A and lal-/- MDSC-like HD1B myeloid cell lines. The GST pull down assay using the recombinant GST-Rab7 GTPase fusion protein showed that Rab7 GTPase interacts with the mTOR N-terminal heat repeat domain. Rab7 GTPase siRNA knocking down reversed the altered lysosome/mTOR distribution and expression levels in HD1B cells. Rab7 GTPase siRNA knocking down in isolated bone marrow lal-/- MDSCs or HD1B cells not only reduced over-activation of mTOR and its downstream effector S6, but also decreased glucose consumption, decreased ROS over-production, and increased healthy mitochondria by membrane potential measurement. Inhibition of Rab7 GTPase led to reduced lal-/- MDSCs differentiation from bone marrow Lin- progenitor cells, reduced lal-/- MDSCs trans-endothelial migration, and reversed lal-/- MDSCs suppression of T cell proliferation. Furthermore, inhibition of Rab7 GTPase reduced lal-/- MDSCs ability to stimulate tumor cell proliferation in vitro, tumor growth in vivo, and tumor invasion. Together, these results showed that Rab7 GTPase is critically involved in MDSCs homeostasis and pathogenic functions.",
keywords = "Lipid metabolism, Myeloid-derived suppressor cells, Rab7 GTPase, Tumor growth",
author = "Xinchun Ding and Wenjing Zhang and Ting Zhao and Cong Yan and Hong Du",
year = "2017",
doi = "10.18632/oncotarget.16280",
language = "English (US)",
volume = "8",
pages = "30123--30137",
journal = "Oncotarget",
issn = "1949-2553",
publisher = "Impact Journals",
number = "18",

}

TY - JOUR

T1 - Rab7 GTPase controls lipid metabolic signaling in myeloidderived suppressor cells

AU - Ding, Xinchun

AU - Zhang, Wenjing

AU - Zhao, Ting

AU - Yan, Cong

AU - Du, Hong

PY - 2017

Y1 - 2017

N2 - Lysosomal acid lipase (LAL) is a critical neutral lipid metabolic enzyme that regulates metabolic reprogramming in myeloid-derived suppressor cells (MDSCs) through over-activation of mammalian target of rapamycin (mTOR). Affymetrix GeneChip microarray analysis of MDSCs from LAL deficient mouse (lal-/- ) revealed upregulation of Rab7 GTPase protein, which belongs to a superfamily of smallmolecular- weight GTPase known to regulate intracellular membrane trafficking from early to late endosomes and lysosomes. Here, the physical protein-protein interaction between Rab7 GTPase and mTOR has been detected by co-immunoprecipitation in the cell extract of wild type HD1A and lal-/- MDSC-like HD1B myeloid cell lines. The GST pull down assay using the recombinant GST-Rab7 GTPase fusion protein showed that Rab7 GTPase interacts with the mTOR N-terminal heat repeat domain. Rab7 GTPase siRNA knocking down reversed the altered lysosome/mTOR distribution and expression levels in HD1B cells. Rab7 GTPase siRNA knocking down in isolated bone marrow lal-/- MDSCs or HD1B cells not only reduced over-activation of mTOR and its downstream effector S6, but also decreased glucose consumption, decreased ROS over-production, and increased healthy mitochondria by membrane potential measurement. Inhibition of Rab7 GTPase led to reduced lal-/- MDSCs differentiation from bone marrow Lin- progenitor cells, reduced lal-/- MDSCs trans-endothelial migration, and reversed lal-/- MDSCs suppression of T cell proliferation. Furthermore, inhibition of Rab7 GTPase reduced lal-/- MDSCs ability to stimulate tumor cell proliferation in vitro, tumor growth in vivo, and tumor invasion. Together, these results showed that Rab7 GTPase is critically involved in MDSCs homeostasis and pathogenic functions.

AB - Lysosomal acid lipase (LAL) is a critical neutral lipid metabolic enzyme that regulates metabolic reprogramming in myeloid-derived suppressor cells (MDSCs) through over-activation of mammalian target of rapamycin (mTOR). Affymetrix GeneChip microarray analysis of MDSCs from LAL deficient mouse (lal-/- ) revealed upregulation of Rab7 GTPase protein, which belongs to a superfamily of smallmolecular- weight GTPase known to regulate intracellular membrane trafficking from early to late endosomes and lysosomes. Here, the physical protein-protein interaction between Rab7 GTPase and mTOR has been detected by co-immunoprecipitation in the cell extract of wild type HD1A and lal-/- MDSC-like HD1B myeloid cell lines. The GST pull down assay using the recombinant GST-Rab7 GTPase fusion protein showed that Rab7 GTPase interacts with the mTOR N-terminal heat repeat domain. Rab7 GTPase siRNA knocking down reversed the altered lysosome/mTOR distribution and expression levels in HD1B cells. Rab7 GTPase siRNA knocking down in isolated bone marrow lal-/- MDSCs or HD1B cells not only reduced over-activation of mTOR and its downstream effector S6, but also decreased glucose consumption, decreased ROS over-production, and increased healthy mitochondria by membrane potential measurement. Inhibition of Rab7 GTPase led to reduced lal-/- MDSCs differentiation from bone marrow Lin- progenitor cells, reduced lal-/- MDSCs trans-endothelial migration, and reversed lal-/- MDSCs suppression of T cell proliferation. Furthermore, inhibition of Rab7 GTPase reduced lal-/- MDSCs ability to stimulate tumor cell proliferation in vitro, tumor growth in vivo, and tumor invasion. Together, these results showed that Rab7 GTPase is critically involved in MDSCs homeostasis and pathogenic functions.

KW - Lipid metabolism

KW - Myeloid-derived suppressor cells

KW - Rab7 GTPase

KW - Tumor growth

UR - http://www.scopus.com/inward/record.url?scp=85018939151&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85018939151&partnerID=8YFLogxK

U2 - 10.18632/oncotarget.16280

DO - 10.18632/oncotarget.16280

M3 - Article

AN - SCOPUS:85018939151

VL - 8

SP - 30123

EP - 30137

JO - Oncotarget

JF - Oncotarget

SN - 1949-2553

IS - 18

ER -