title: In vitro requirement for periostin in B lymphopoiesis.
abstract: B lymphopoiesis arrests in rabbits by 4 months of age. To identify molecules that contribute to this arrest, cDNA-representational difference analysis on BM stromal cells from young and adult rabbits showed that expression of Postn that encodes for the extracellular matrix protein periostin dramatically reduced with age. Postn-small interfering RNA OP9 cells lost their capacity to support B-cell development from rabbit or murine BM cells, and reexpression of periostin restored this potential, indicating an in vitro requirement for periostin in B lymphopoiesis. In our system, we determined that periostin deficiency leads to increased cell death and decreased proliferation of B-lineage progenitors. Further, RGD peptide inhibition of periostin/α(v)β(3) interaction resulted in a marked decrease in B lymphopoiesis in vitro. Microarray analysis of the Postn-small interfering RNA OP9 cells showed decreased expression of key B-lymphopoietic factors, including IL-7 and CXCL12. In vivo, unidentified molecule(s) probably compensate periostin loss because Postn(-/-) mice had normal numbers of B-cell progenitors in BM. We conclude that the decline in periostin expression in adult rabbit BM does not solely explain the arrest of B lymphopoiesis. However, the interaction of periostin with α(v)β(3) on lymphoid progenitors probably provides both proliferative and survival signals for cells in the B-cell development pathway.
authors.affiliation: Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, 2160 S. First Ave., Maywood, IL 60153, USA.
authors.forename: Basile T
authors.initials: BT
authors.lastname: Siewe
authors.forename: Susan L
authors.initials: SL
authors.lastname: Kalis
authors.forename: Phong T
authors.initials: PT
authors.lastname: Le
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Witte
authors.forename: Sangdun
authors.initials: S
authors.lastname: Choi
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Conway
authors.forename: Laurel
authors.initials: L
authors.lastname: Druschitz
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Knight
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D038041:Lymphopoiesis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D054448:Precursor Cells, B-Lymphoid / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D034741:RNA, Small Interfering / Q000494:pharmacology; D011817:Rabbits
chemical_list: D015815:Cell Adhesion Molecules; C082838:Postn protein, mouse; D034741:RNA, Small Interfering