Related Experiment Video

Updated: Jun 12, 2026

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

β-arrestin 2 regulates Toll-like receptor 4-mediated apoptotic signalling through glycogen synthase kinase-3β

Hui Li1, Xiuli Sun, Gene LeSage

  • 1Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Immunology
|May 26, 2010
PubMed

Insights

Toll-like receptor 4 (TLR4) accelerates cell apoptosis via the GSK-3beta pathway. Beta-arrestin 2 inhibits this process by stabilizing inactive GSK-3beta, offering a new therapeutic target for apoptosis regulation.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Signaling

Background:

  • Toll-like receptor 4 (TLR4) is known for its role in innate immunity and inflammation.
  • Its involvement in apoptosis, particularly through specific molecular mechanisms, remains an area of significant interest.
  • Glycogen synthase kinase-3beta (GSK-3beta) is implicated in cellular apoptosis pathways.

Purpose of the Study:

  • To elucidate the mechanism by which TLR4 influences apoptosis.
  • To investigate the role of the GSK-3beta pathway in TLR4-mediated apoptosis.
  • To determine the function of beta-arrestin 2 in regulating TLR4-induced apoptotic signaling.

Main Methods:

  • Utilized a serum-deprivation-induced apoptosis model.
  • Investigated the activation of GSK-3beta in the presence and absence of TLR4.
  • Examined the effect of beta-arrestin 2 on TLR4-mediated apoptotic signaling and GSK-3beta phosphorylation status.

Main Results:

  • TLR4 promotes apoptosis by activating the GSK-3beta pathway.
  • This TLR4-induced apoptotic cascade is amplified by TLR4 and attenuated by beta-arrestin 2.
  • Beta-arrestin 2 stabilizes phospho-GSK-3beta (inactive form), thereby inhibiting TLR4-mediated apoptosis.

Conclusions:

  • TLR4 accelerates GSK-3beta activation, exacerbating serum-deprivation-induced apoptosis.
  • Beta-arrestin 2 inhibits TLR4-mediated apoptosis by regulating GSK-3beta activation/inactivation homeostasis.
  • These findings highlight a novel role for TLR4 and beta-arrestin 2 in apoptosis regulation via GSK-3beta signaling.

More Related Videos

Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with β-arrestin13:45

Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with β-arrestin

Published on: December 23, 2010

Related Concept Videos

PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
Enzyme-linked Receptors01:00

Enzyme-linked Receptors

Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...