Related Experiment Video

Updated: Aug 3, 2026

Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages
10:07

Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages

Published on: June 23, 2013

Pyk2 regulates multiple signaling events crucial for macrophage morphology and migration

M Okigaki1, C Davis, M Falasca

  • 1Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.

Proceedings of the National Academy of Sciences of the United States of America
|September 10, 2003
PubMed

Insights

The protein tyrosine kinase Pyk2 is essential for macrophage migration and function. Pyk2 knockout mice exhibit impaired inflammatory responses due to defective macrophage polarization, migration, and signaling.

Area of Science:

  • Cell Biology
  • Immunology
  • Biochemistry

Background:

  • Protein tyrosine kinases play crucial roles in cellular signaling pathways.
  • Pyk2 (proline-rich tyrosine kinase 2) is a non-receptor tyrosine kinase implicated in various cellular processes.

Purpose of the Study:

  • To elucidate the biological role of Pyk2 in mammalian cells, particularly in macrophages.
  • To investigate the impact of Pyk2 deficiency on macrophage morphology, migration, and signaling.

Main Methods:

  • Homologous recombination was used to generate Pyk2 knockout (Pyk2-/-) mice.
  • Macrophage behavior, including polarization, membrane ruffling, migration, and contractile activity, was assessed.
  • Optical tweezers were employed to measure lamellipodia contractility.
  • Macrophage infiltration into inflammatory sites in vivo was evaluated.
  • Chemokine and integrin-induced signaling pathways were analyzed in Pyk2-/- macrophages.

Main Results:

  • Pyk2-/- mice were viable and fertile with no apparent developmental or behavioral defects.
  • Pyk2-/- macrophages exhibited impaired polarization, membrane ruffling, and chemokine-induced migration.
  • Macrophage contractile activity in lamellipodia was significantly reduced in the absence of Pyk2.
  • Infiltration of macrophages into inflammatory sites was strongly inhibited in Pyk2-/- mice.
  • Chemokine-induced inositol triphosphate production, Ca2+ release, and integrin-induced activation of Rho and phosphatidyl inositol 3 kinase were compromised in Pyk2-/- macrophages.

Conclusions:

  • Pyk2 plays a critical role in regulating macrophage migration and function.
  • Pyk2 is essential for proper cell signaling pathways governing macrophage motility and inflammatory responses.
  • Targeting Pyk2 may offer therapeutic strategies for modulating inflammatory diseases.

More Related Videos

Protrusion Force Microscopy: A Method to Quantify Forces Developed by Cell Protrusions06:37

Protrusion Force Microscopy: A Method to Quantify Forces Developed by Cell Protrusions

Published on: June 16, 2018

Reprograming Model of Human Monocyte-derived Macrophages for In-vitro Assays08:37

Reprograming Model of Human Monocyte-derived Macrophages for In-vitro Assays

Published on: April 18, 2025

Related Concept Videos

Cell Migration01:09

Cell Migration

Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
Cell Polarization by Rho Proteins01:21

Cell Polarization by Rho Proteins

Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...
Cytoskeletal Coordination in Cell Migration01:32

Cytoskeletal Coordination in Cell Migration

A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker proteins that...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...