Pro-inflammatory macrophages coupled with glycolysis remodel adipose vasculature by producing platelet-derived growth factor-B in obesity

Sci Rep. 2020 Jan 20;10(1):670. doi: 10.1038/s41598-019-57368-w.

Abstract

Adipose tissue macrophages (ATMs) play a central role in tissue remodeling and homeostasis. However, whether ATMs promote adipose angiogenesis in obesity remains unclear. We examined the impact of ATMs deletion on adipose angiogenesis and tissue expansion in the epididymal white adipose tissue (eWAT) of high-fat diet (HFD)-fed mice by using liposome-encapsulated clodronate. We further elucidated the induction mechanisms of platelet-derived growth factor (PDGF)-B in macrophages in response to obesity-associated metabolic stresses, since it plays a significant role in the regulation of pericyte behavior for the initiation of neoangiogenesis during tissue expansion. ATM depletion prevented adipose tissue expansion in HFD-fed mice by inhibiting pericyte detachment from vessels, resulting in less vasculature in eWAT. The lipopolysaccharide (LPS) stimulation and high glucose concentration augmented glucose incorporation and glycolytic capacity with the induction of Pdgfb mRNA. This effect was mediated through extracellular signal-regulated kinase (ERK) among mitogen-activated protein kinases coupled with glycolysis in RAW264.7 macrophages. The Pdgfb induction system was distinct from that of inflammatory cytokines mediated by mechanistic target of rapamycin complex 1 (mTORC1) and NFκB signaling. Thus, obesity-associated hyperglycemia and chronic inflammation fuels ERK signaling coupled with glycolysis in pro-inflammatory macrophages, which contribute to the expansion of eWAT through PDGF-B-dependent vascular remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, White / blood supply*
  • Adipose Tissue, White / cytology*
  • Animals
  • Diet, High-Fat / adverse effects
  • Glycolysis* / genetics
  • Inflammation
  • Lymphokines / genetics
  • Lymphokines / metabolism
  • MAP Kinase Signaling System
  • Macrophages / metabolism
  • Macrophages / physiology*
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Mice
  • NF-kappa B / metabolism
  • Neovascularization, Pathologic*
  • Obesity / etiology
  • Obesity / metabolism
  • Obesity / pathology*
  • Platelet-Derived Growth Factor / genetics
  • Platelet-Derived Growth Factor / metabolism
  • Proto-Oncogene Proteins c-sis / metabolism*
  • RAW 264.7 Cells
  • RNA, Messenger / metabolism
  • Signal Transduction
  • Vascular Remodeling / genetics*

Substances

  • Lymphokines
  • NF-kappa B
  • Pdgfd protein, mouse
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins c-sis
  • RNA, Messenger
  • Mechanistic Target of Rapamycin Complex 1