Related Experiment Videos
Platelet derived growth factor-BB induced calcium transients in cultured human peritoneal mesothelial cells
Abstract:
The peritoneal membrane is used as an artificial dialysis organ for patients with end-stage renal failure during continuous ambulatory peritoneal dialysis (CAPD). Resident peritoneal mast cells may influence the course of the inflammatory process during acute infection or prolonged exposure to dialysate in a paracrine fashion, with the release of preformed mediators, including platelet derived growth factor (PDGF), which may activate human peritoneal mesothelial cells (HPMC) and other peritoneal cells. PDGF receptor interactions have multiple intracellular effects, typified by cell proliferation, protein synthesis, cytoskeletal organization, extracellular matrix turnover, and angiogenesis. PDGF may mediate HPMC inflammatory response by stimulating cytokine release. The presence of transcripts for both PDGF-B polypeptide and PDGF-beta receptor in cultured HPMC was confirmed using a reverse transcriptase-polymerase chain reaction. To investigate the activity of PDGF-beta receptors in HPMC, the authors examined intracellular calcium (Ca2+(i)) mobilization in HPMC in response to PDGF-BB (100 ng/ml), histamine (1.0 mmol/L), and 4-brA23187 (1.0 micromol/L) using the calcium indicator, fura-2. HPMC calcium mobilization in response to PDGF was assessed in Krebs-Ringer saline, with and without added external calcium (Ca2+(ext)). HPMC responded to PDGF with a transient rise in Ca2+(i) (approximately 1.6-fold) that returned to an elevated resting value. In the absence of Ca2+(ext), PDGF produced a Ca2+(i) transient indicative of Ca2+ release from intracellular stores. These results suggest that HPMC have functional PDGF-beta receptors that may bind and respond to PDGF in both an autocrine and paracrine
Insights
Platelet-derived growth factor (PDGF) activates human peritoneal mesothelial cells (HPMC) via functional PDGF-beta receptors. This interaction influences intracellular calcium mobilization, suggesting a role in peritoneal dialysis inflammation.
Area of Science:
- Peritoneal dialysis
- Cell biology
- Inflammation research
Background:
- The peritoneal membrane serves as an artificial kidney in continuous ambulatory peritoneal dialysis (CAPD).
- Peritoneal mast cells and platelet-derived growth factor (PDGF) may play a role in inflammation during CAPD.
- PDGF signaling impacts cell proliferation, protein synthesis, and angiogenesis.
Purpose of the Study:
- To investigate the presence and function of PDGF-beta receptors in human peritoneal mesothelial cells (HPMC).
- To determine if PDGF can activate HPMC and influence intracellular calcium levels.
Main Methods:
- Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect PDGF-B and PDGF-beta receptor transcripts in cultured HPMC.
- Intracellular calcium (Ca2+(i)) mobilization in HPMC was measured using the fura-2 indicator in response to PDGF-BB, histamine, and 4-brA23187.
- Experiments were conducted with and without external calcium (Ca2+(ext)) to assess the source of calcium release.
Main Results:
- HPMC express transcripts for both PDGF-B and its beta receptor.
- HPMC responded to PDGF-BB with a transient increase in intracellular calcium (Ca2+(i)), indicating receptor activation.
- PDGF-induced calcium mobilization occurred even without external calcium, suggesting release from intracellular stores.
Conclusions:
- Human peritoneal mesothelial cells possess functional PDGF-beta receptors.
- PDGF can activate HPMC, potentially mediating inflammatory responses in the peritoneal membrane during CAPD through autocrine or paracrine signaling.