Abstract
We have used an in vitro culture system to study the role of extracellular matrix (ECM) in the fragmentation of guinea pig bone marrow megakaryocytes (MK) and the formation of proplatelet fragments from these cells. Proplatelet formation is stimulated by culturing the cells on a hydrated type I collagen gel in the presence of serum. MK express integrin proteins alpha5, alpha6, beta1, and the alpha(v) beta3 complex as demonstrated by immunofluorescence. A monoclonal antibody, LM 609, to the alpha(v) beta3 vitronectin receptor blocked proplatelet formation, whereas the monoclonal antibodies to the beta1, alpha5, and alpha6 integrin proteins did not inhibit proplatelet formation. The tetrapeptide Arg-Gly-Asp-Ser (RGDS) inhibits proplatelet formation; however, there was no inhibition by the fibronectin receptor-specific peptide GRGDdSP. The fibrinogen gamma chain peptide HHLGGAKQAGDV, which binds to the platelet membrane glycoprotein complex IIb-IIIa but not to the vitronectin receptor (VnR), did not inhibit proplatelet formation, nor did two different laminin peptides. In the absence of serum, 5.7% of MK spontaneously formed processes or fragmented. The addition of 50 μg/ml of vitronectin to serum-free cultures increased proplatelet formation to 21.5% of the MK, equal to cultures with 10% serum. Stimulation of proplatelet formation by vitronectin in serum-free cultures was inhibited by LM 609. Antibody staining with anti-bovine vitronectin antibody showed that MK contain intracellular vitronectin. These data show that guinea pig MK express alpha5, alpha6, beta1, and alpha(v) beta3 integrins. However, only the MK vitronectin receptor and its interaction with vitronectin plays an essential role in proplatelet formation in vitro.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1316-1322 |
| Number of pages | 7 |
| Journal | Experimental Hematology |
| Volume | 20 |
| Issue number | 11 |
| State | Published - 1992 |
| Externally published | Yes |
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Keywords
- extracellular matrix
- integrin proteins
- megakaryocytes
- vitronectin receptor
ASJC Scopus subject areas
- Cancer Research
- Cell Biology
- Genetics
- Hematology
- Oncology
- Transplantation
Cite this
Extracellular matrix stimulation of guinea pig megakaryocyte proplatelet formation in vitro is mediated through the vitronectin receptor. / Leven, R. M.; Tablin, Fern.
In: Experimental Hematology, Vol. 20, No. 11, 1992, p. 1316-1322.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Extracellular matrix stimulation of guinea pig megakaryocyte proplatelet formation in vitro is mediated through the vitronectin receptor
AU - Leven, R. M.
AU - Tablin, Fern
PY - 1992
Y1 - 1992
N2 - We have used an in vitro culture system to study the role of extracellular matrix (ECM) in the fragmentation of guinea pig bone marrow megakaryocytes (MK) and the formation of proplatelet fragments from these cells. Proplatelet formation is stimulated by culturing the cells on a hydrated type I collagen gel in the presence of serum. MK express integrin proteins alpha5, alpha6, beta1, and the alpha(v) beta3 complex as demonstrated by immunofluorescence. A monoclonal antibody, LM 609, to the alpha(v) beta3 vitronectin receptor blocked proplatelet formation, whereas the monoclonal antibodies to the beta1, alpha5, and alpha6 integrin proteins did not inhibit proplatelet formation. The tetrapeptide Arg-Gly-Asp-Ser (RGDS) inhibits proplatelet formation; however, there was no inhibition by the fibronectin receptor-specific peptide GRGDdSP. The fibrinogen gamma chain peptide HHLGGAKQAGDV, which binds to the platelet membrane glycoprotein complex IIb-IIIa but not to the vitronectin receptor (VnR), did not inhibit proplatelet formation, nor did two different laminin peptides. In the absence of serum, 5.7% of MK spontaneously formed processes or fragmented. The addition of 50 μg/ml of vitronectin to serum-free cultures increased proplatelet formation to 21.5% of the MK, equal to cultures with 10% serum. Stimulation of proplatelet formation by vitronectin in serum-free cultures was inhibited by LM 609. Antibody staining with anti-bovine vitronectin antibody showed that MK contain intracellular vitronectin. These data show that guinea pig MK express alpha5, alpha6, beta1, and alpha(v) beta3 integrins. However, only the MK vitronectin receptor and its interaction with vitronectin plays an essential role in proplatelet formation in vitro.
AB - We have used an in vitro culture system to study the role of extracellular matrix (ECM) in the fragmentation of guinea pig bone marrow megakaryocytes (MK) and the formation of proplatelet fragments from these cells. Proplatelet formation is stimulated by culturing the cells on a hydrated type I collagen gel in the presence of serum. MK express integrin proteins alpha5, alpha6, beta1, and the alpha(v) beta3 complex as demonstrated by immunofluorescence. A monoclonal antibody, LM 609, to the alpha(v) beta3 vitronectin receptor blocked proplatelet formation, whereas the monoclonal antibodies to the beta1, alpha5, and alpha6 integrin proteins did not inhibit proplatelet formation. The tetrapeptide Arg-Gly-Asp-Ser (RGDS) inhibits proplatelet formation; however, there was no inhibition by the fibronectin receptor-specific peptide GRGDdSP. The fibrinogen gamma chain peptide HHLGGAKQAGDV, which binds to the platelet membrane glycoprotein complex IIb-IIIa but not to the vitronectin receptor (VnR), did not inhibit proplatelet formation, nor did two different laminin peptides. In the absence of serum, 5.7% of MK spontaneously formed processes or fragmented. The addition of 50 μg/ml of vitronectin to serum-free cultures increased proplatelet formation to 21.5% of the MK, equal to cultures with 10% serum. Stimulation of proplatelet formation by vitronectin in serum-free cultures was inhibited by LM 609. Antibody staining with anti-bovine vitronectin antibody showed that MK contain intracellular vitronectin. These data show that guinea pig MK express alpha5, alpha6, beta1, and alpha(v) beta3 integrins. However, only the MK vitronectin receptor and its interaction with vitronectin plays an essential role in proplatelet formation in vitro.
KW - extracellular matrix
KW - integrin proteins
KW - megakaryocytes
KW - vitronectin receptor
UR - http://www.scopus.com/inward/record.url?scp=0026489564&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026489564&partnerID=8YFLogxK
M3 - Article
C2 - 1283596
AN - SCOPUS:0026489564
VL - 20
SP - 1316
EP - 1322
JO - Experimental Hematology
JF - Experimental Hematology
SN - 0301-472X
IS - 11
ER -