title: SPARC deficiency affects bone marrow stromal function, resulting in impaired B lymphopoiesis.
abstract: It has been demonstrated that B cells were decreased in the BM of SPARC-null mice, accompanied by a lack of immune response to LPS. However, the effect of SPARC deficiency on B lymphopoiesis remains unclear. Herein, we investigated the role of SPARC in the regulation of B lymphopoiesis, as well as the underlying molecular mechanisms. In present study, we found that the size of B-lineage progenitors (pro-B and pre-B plus immature B cells) and primitive hematopoietic cells (LSK and LTC cells) were reduced, whereas multipotent progenitors (CFU-S12) were increased in BM of SPARC-null mice. When SPARC-null BM cells were transplanted into lethally irradiated WT mice, the B cell population in recipients was restored to a level equivalent to that generated by WT BM cells, suggesting that the changes of the BM microenvironment in SPARC-null mice affect B lymphopoiesis. Furthermore, we found that SPARC-null BMSCs did not support the differentiation of WT BM cells into the B cell population in vitro, and conditioned medium derived from SPARC-null BMSCs inhibited B cell differentiation. However, the addition of rmSPARC to the coculture system did not restore the impaired B lymphopoiesis. In summary, our findings suggest that SPARC plays a crucial role in the regulation of early B lymphopoiesis.
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and Departments of Clinical Laboratory, Third Xiangya Hospital, and.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Neurosurgery, Second Xiangya Hospital, Central South University, Changsha, China;
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and Department of Oncology, First Hospital of Yueyang, Yueyang, China;
authors.forename: Pan
authors.initials: P
authors.lastname: Luo
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and.
authors.forename: Na
authors.initials: N
authors.lastname: Xiao
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and National Engineering Research Center of Human Stem Cells, Changsha, China; and.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Biological Structure, School of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and National Engineering Research Center of Human Stem Cells, Changsha, China; and lugxdirector@aliyun.com mmlamei@163.com.
authors.forename: Guangxiu
authors.initials: G
authors.lastname: Lu
authors.affiliation: Institute of Reproductive and Stem Cell Engineering and National Engineering Research Center of Human Stem Cells, Changsha, China; and lugxdirector@aliyun.com mmlamei@163.com.
authors.forename: Lamei
authors.initials: L
authors.lastname: Cheng
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000502:physiology*; D018920:Coculture Techniques; D038041:Lymphopoiesis / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains; D039902:Multipotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D015676:Osteonectin / Q000235:genetics / Q000378:metabolism*; D054448:Precursor Cells, B-Lymphoid / Q000166:cytology / Q000378:metabolism*; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D015676:Osteonectin; C578250:SPARC protein, mouse
keywords: B cell progenitors; BM stromal cells; primitive hematopoietic cells