title: Basic fibroblast growth factor (bFGF) and its receptor expression (bek and flg) In bone marrow stroma of murine AIDS.
abstract: Murine acquired immunodeficiency disease (MAIDS) induced by LPBM5 MuLV is characterized by a late-stage lymphoma and hematopoietic cytopenias similar to those observed in human AIDS. The pathogenesis of MAIDS-related lymphoma/cytopenia is unknown but it has been postulated to involve a defective marrow microenvironment or stroma. The basic Fibroblast Growth Factor (bFGF) of stromal origin is an important stimulator for hematopoietic progenitors of several lineages. Long-term bone marrow cultures (LTBMCs) were established and pure stromal cell cultures were used for in vitro infection hematopoietic reconstitution studies. Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze bFGF gene expression in stromal cells derived from either viral-infected marrow or uninfected marrow. RT-PCR analysis showed a 40% reduction in the expression of bFGF transcript expression from viral-infected stromal cells, however, the levels of bek and flg bFGF receptors remained unchanged indicating virus-infection only inhibited bFGF gene expression in stromal cells. Viral infection was associated with a progressive decrease in bFGF transcript expression 35% of control at day 7, 50% of control at day 14 and 60% of control at day 21 compared to the mock-infected cultures. In addition, for bek and flg the transcript expression in, in vitro-infected primary cultures were comparable to the mock-infected cultures and remained essentially unchanged throughout culture period. Western blot analysis revealed viral-infected stromal cells produced a 45% decrease in bFGF protein production. Reduction of bFGF protein was confirmed by indirect immunofluorescent staining. We report MuLV infection reduces bFGF transcript expression but not its surface-receptors (bek and flg) in infected stromal cells. Impaired hematopoiesis consistently exhibited from MuLV-infected stromal cultures was restored by exogenous bFGF; therefore, bFGF was responsible in restoration of normal marrow stromal support function. These results suggest a role for bFGF deficiency in the pathogenesis of MAIDS-related marrow failure.
authors.affiliation: Hematology/Oncology Division, Laboratory of Experimental Immunohematopoiesis and Developmental Therapeutics, Department of Internal Medicine,University of Kentucky, Lexington, KY 40536-0084, USA.
authors.forename: Kam-Fai
authors.initials: KF
authors.lastname: Tse
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Inayat
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Morrow
authors.forename: Richard
authors.initials: R
authors.lastname: DellaPuca
authors.forename: Nedda K
authors.initials: NK
authors.lastname: Hughes
authors.forename: Vincent S
authors.initials: VS
authors.lastname: Gallicchio
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism / Q000821:virology*; D002460:Cell Line; D003114:Colony-Forming Units Assay; D016222:Fibroblast Growth Factor 2 / Q000032:analysis / Q000235:genetics* / Q000494:pharmacology; D000091344:Filaggrin Proteins; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects; D009052:Leukemia Virus, Murine / Q000472:pathogenicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D016183:Murine Acquired Immunodeficiency Syndrome / Q000821:virology; D012333:RNA, Messenger / Q000032:analysis; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism / Q000821:virology*; D014158:Transcription, Genetic
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; C496354:Fgfr2 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2