Related Experiment Video

Updated: Jul 17, 2026

Harvesting Murine Alveolar Macrophages and Evaluating Cellular Activation Induced by Polyanhydride Nanoparticles
11:26

Harvesting Murine Alveolar Macrophages and Evaluating Cellular Activation Induced by Polyanhydride Nanoparticles

Published on: June 8, 2012

Poly(I:C)-stimulated alveolar macrophages modulate extracellular matrix turnover and fibroblast activation through

Chen-Ni Chang1, Cheng-Fang Tsai2, Yen-Chang Chen1

  • 1Institute of Translational Medicine and New Drug Development, China Medical University, No.91 Hsueh-Shih Road, Taichung, 404333, Taiwan.

European Journal of Pharmacology
|July 15, 2026
PubMed
Abstract

Insights

Macrophages regulate lung fibrosis by secreting cystatin 6, which controls fibroblast activity via cathepsin B. This pathway offers insights into resolving fibrotic responses.

Area of Science:

  • Immunology
  • Cell Biology
  • Pulmonary Medicine

Background:

  • Pulmonary fibrosis involves fibroblast activation and extracellular matrix deposition.
  • Macrophages are key in tissue repair but their role in modulating fibroblast phenotypes is unclear.

Purpose of the Study:

  • To investigate the molecular mechanisms by which macrophages influence fibroblast behavior in pulmonary fibrosis.

Main Methods:

  • Alveolar macrophages were stimulated with poly(I:C) and their secretome analyzed.
  • Fibroblasts were exposed to macrophage conditioned medium (CM) to assess fibrogenic responses.

Main Results:

  • Poly(I:C)-stimulated macrophage CM reduced pro-fibrotic markers and fibroblast activation markers.
  • Macrophage CM induced cathepsin B in fibroblasts; its inhibition restored fibroblast activation.
  • Poly(I:C) reduced macrophage cystatin 6 secretion, impacting fibrogenesis.

Conclusions:

  • A novel macrophage cystatin 6-fibroblast cathepsin B axis regulates fibroblast behavior and fibrotic responses.
  • This pathway provides mechanistic insights into resolving fibrotic processes in the lung.
Keywords:
Alveolar macrophagesCathepsinCystatinFibroblastspoly(I:C)

More Related Videos

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition06:02

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition

Published on: June 10, 2016

Flow Cytometric Isolation of Primary Murine Type II Alveolar Epithelial Cells for Functional and Molecular Studies14:48

Flow Cytometric Isolation of Primary Murine Type II Alveolar Epithelial Cells for Functional and Molecular Studies

Published on: December 26, 2012

Related Concept Videos

The Extracellular Matrix01:29

The Extracellular Matrix

Overview
In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, the molecules in the ECM maintain the structural integrity of tissue as well as the remarkable specific properties of certain tissues.
Composition of the Extracellular Matrix
The extracellular matrix (ECM) is commonly composed of ground substance, a gel-like fluid, fibrous components, and many structurally and functionally diverse...
The Extracellular Matrix01:42

The Extracellular Matrix

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, the molecules in the ECM maintain the structural integrity of tissue as well as the remarkable specific properties of certain tissues.Composition of the Extracellular MatrixThe extracellular matrix (ECM) is commonly composed of ground substance, a gel-like fluid, fibrous components, and many structurally and functionally diverse molecules.
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...
Chronic Inflammation: Introduction01:12

Chronic Inflammation: Introduction

Chronic inflammation is a prolonged, dysregulated immune response that persists for weeks to years when the inciting stimulus is difficult to eradicate or when self‑antigens drive ongoing reactivity. Morphologically, it is defined by mononuclear cell infiltration, progressive tissue destruction, and concurrent attempts at healing via angiogenesis and fibrosis. Compared with acute inflammation, edema is less prominent while cellular infiltration predominates; triggers include persistent...
Structural Protein Function01:56

Structural Protein Function

Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity.  In bones and teeth, it mineralizes to form...
Extracellular Matrix01:26

Extracellular Matrix

Unlike epithelial tissue, which is composed of cells closely packed with little or no extracellular space in between, connective tissue cells are dispersed in a matrix. This extracellular matrix (ECM) is composed of fibrous proteins like collagen, elastin, and fibronectin in a ground substance consisting of interstitial fluid, cell adhesion proteins, and proteoglycans. The proteoglycans form a gel-like material in the spaces between cells and provide hydration, buffering, binding, and force...