Related Experiment Video

Updated: Feb 20, 2026

Software-Assisted Quantitative Measurement of Osteoarthritic Subchondral Bone Thickness
08:52

Software-Assisted Quantitative Measurement of Osteoarthritic Subchondral Bone Thickness

Published on: March 18, 2022

3.5K

PDK1 promotes apoptosis of chondrocytes via modulating MAPK pathway in osteoarthritis

Qingtian Ge1, Hailin Wang1, Xinbao Xu1

  • 1Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong University, Nantong 226001, China.

Tissue & Cell
|October 25, 2017
PubMed

Insights

3-Phosphoinositide dependent protein kinase-1 (PDK1) promotes chondrocyte apoptosis in osteoarthritis (OA). PDK1 activation via the p38 MAPK pathway is implicated in OA pathogenesis, suggesting potential therapeutic targets.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Orthopedics

Background:

  • Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage breakdown and chondrocyte apoptosis.
  • 3-Phosphoinositide dependent protein kinase-1 (PDK1), a key AGC kinase family member, is implicated in cellular processes including apoptosis.

Purpose of the Study:

  • To investigate the expression of PDK1 in OA articular cartilage.
  • To analyze the relationship between PDK1 and chondrocyte apoptosis in OA.
  • To elucidate the role of PDK1 in OA-like chondrocyte injury in vitro.

Main Methods:

  • Immunohistochemistry and RT-PCR to assess PDK1 expression in human cartilage.
  • In vitro study using IL-1β-stimulated SW1353 cells to mimic OA chondrocyte injury.
  • Western blot, immunofluorescence, siRNA-mediated knockdown, and Annexin V/PI staining to evaluate PDK1's role in apoptosis and signaling pathways.

Main Results:

  • PDK1 expression was detected in articular cartilage of OA patients and controls.
  • IL-1β stimulation increased PDK1, apoptotic markers (PARP, caspase-3), and phosphorylated p38 in SW1353 cells.
  • PDK1 knockdown reduced IL-1β-induced chondrocyte apoptosis and p38 MAPK phosphorylation.

Conclusions:

  • PDK1 expression is present in articular cartilage and is upregulated in OA.
  • PDK1 promotes chondrocyte apoptosis in OA, potentially through the p38 MAPK signaling pathway.
  • PDK1 represents a potential therapeutic target for osteoarthritis.
Keywords:
Interleukin-1&βMapkOsteoarthritis apoptosisPDK1

More Related Videos

Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway07:15

Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway

Published on: August 23, 2024

972

Related Concept Videos

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...
8.7K
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...
7.4K
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...
8.8K
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
6.1K
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...
13.3K
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...
8.9K