Related Experiment Video

Updated: May 20, 2026

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay
11:38

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay

Published on: September 14, 2021

Lipopolysaccharide regulates MMP-9 expression through TLR4/NF-κB signaling in human arterial smooth muscle cells

Hongli Li1, Hao Xu, Baogui Sun

  • 1Department of Cardiology, Shanghai First People's Hospital, College of Medicine, Shanghai Jiaotong University, Shanghai, PR China.

Molecular Medicine Reports
|July 31, 2012
PubMed

Insights

Lipopolysaccharides (LPS) increase matrix metalloproteinase-9 (MMP-9) in human arterial smooth muscle cells. This occurs via the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) pathway, potentially contributing to atherosclerosis.

Area of Science:

  • Vascular Biology
  • Immunology
  • Cellular Signaling

Background:

  • Matrix metalloproteinases (MMPs) are crucial for vascular smooth muscle cell migration.
  • MMP dysregulation contributes to atherosclerosis, arterial remodeling, and aneurysm formation.
  • Lipopolysaccharides (LPS) are a significant risk factor for atherosclerosis development.

Purpose of the Study:

  • To investigate the mechanism by which LPS influences MMP-9 expression in human arterial smooth muscle cells (HASMCs).
  • To elucidate the role of Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) in LPS-induced MMP-9 expression.

Main Methods:

  • Reverse transcription-polymerase chain reaction (RT-PCR) to quantify MMP-9 mRNA.
  • Western blot analysis to assess MMP-9 protein levels.
  • Electrophoretic mobility shift assay (EMSA) to determine NF-κB binding activity.
  • Inhibition of NF-κB binding using pyrrolidine dithiocarbamate.

Main Results:

  • LPS significantly induced both MMP-9 mRNA and protein expression in HASMCs.
  • The LPS-induced MMP-9 expression was dependent on Toll-like receptor 4 (TLR4).
  • Blocking NF-κB activation abrogated LPS-induced MMP-9 expression, confirming the involvement of the TLR4/NF-κB pathway.

Conclusions:

  • LPS induces MMP-9 expression in HASMCs through the TLR4/NF-κB signaling pathway.
  • This pathway represents a potential mechanism linking LPS exposure to the pathogenesis of atherosclerosis.
  • Targeting the TLR4/NF-κB pathway could offer therapeutic strategies for atherosclerosis.

More Related Videos

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces07:55

A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces

Published on: January 7, 2020

Myeloid Innate Signaling Pathway Regulation by MALT1 Paracaspase Activity07:09

Myeloid Innate Signaling Pathway Regulation by MALT1 Paracaspase Activity

Published on: January 7, 2019

Related Concept Videos

Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
Role of Matrix Metalloproteases in Degradation of ECM01:23

Role of Matrix Metalloproteases in Degradation of ECM

Matrix metalloproteases (MMPs) are enzymes involved in the hydrolysis of proteins and glycoproteins of the extracellular matrix. MMPs are essential for the migration and proliferation of cells through the dense matrix network, throughout embryonic development, and throughout morphogenesis. The first MMP activity discovered was a collagenase in a tadpole's tail undergoing metamorphosis. The active collagen deposition and modifications lead to the morphogenesis of tadpoles into the adult body.
A...
Nitric Oxide Signaling Pathway01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...