Faculty Opinions recommendation of Hematopoietic insults damage bone marrow niche by activating p53 in vascular endothelial cells.

Pulmonary vascular endothelial function may be impaired by oxidative stress in endotoxemia-derived acute lung injury. Growing evidence suggests that endothelial-to-mesenchymal transition (EndMT) could play a pivotal role in various respiratory diseases; however, it remains unclear whether EndMT participates in the injury/repair process of septic acute lung injury. Here, we analyzed lipopolysaccharide (LPS)-treated mice whose total number of pulmonary vascular endothelial cells (PVECs) transiently decreased after production of reactive oxygen species (ROS), while the population of EndMT-PVECs significantly increased. NAD(P)H oxidase inhibition suppressed EndMT of PVECs. Most EndMT-PVECs derived from tissue-resident cells, not from bone marrow, as assessed by mice with chimeric bone marrow. Bromodeoxyuridine-incorporation assays revealed higher proliferation of capillary EndMT-PVECs. In addition, EndMT-PVECs strongly expressed c- kit and CD133. LPS loading to human lung microvascular endothelial cells (HMVEC-Ls) induced reversible EndMT, as evidenced by phenotypic recovery observed after removal of LPS. LPS-induced EndMT-HMVEC-Ls had increased vasculogenic ability, aldehyde dehydrogenase activity, and expression of drug resistance genes, which are also fundamental properties of progenitor cells. Taken together, our results demonstrate that LPS induces EndMT of tissue-resident PVECs during the early phase of acute lung injury, partly mediated by ROS, contributing to increased proliferation of PVECs.

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The bone marrow niche components are adversely affected in sepsis

Molecular Biomedicine ◽

10.1186/s43556-020-00010-3 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Fan Yin ◽

Han Qian ◽

Caiwen Duan ◽

Botao Ning

Keyword(s):

Bone Marrow ◽

Vascular Endothelial Cells ◽

Cecal Ligation ◽

Treg Cells ◽

Multiple Organ ◽

Bone Marrow Niche ◽

Vascular Endothelial ◽

Bm Niche ◽

Cell Components ◽

The Impact

Abstract Multiple organ dysfunction is an important cause of death in patients with sepsis. Currently, few studies have focused on the impact of sepsis on bone marrow (BM), especially on the cell components of BM niche. In this study, we performed mouse sepsis models by intraperitoneal injection of LPS and cecal ligation and puncture (CLP). The changes of niche major components in the mouse BM among vascular structures, mesenchymal stem cells and Treg cells were observed and analyzed. The results showed that pathological changes in BM was earlier and more prominent than in other organs, and various cell components of the BM niche changed significantly, of which vascular endothelial cells increased transiently with vascular remodeling and the regulatory T cells decreased over a long period of time. These results indicated that the components of the BM niche underwent series of adaptive changes in sepsis.

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PTPN21 Overexpression Promotes Osteogenic and Adipogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells but Inhibits the Immunosuppressive Function

Stem Cells International ◽

10.1155/2019/4686132 ◽

2019 ◽

Vol 2019 ◽

pp. 1-19 ◽

Cited By ~ 1

Author(s):

Huafang Wang ◽

Xiaohang Ye ◽

Haowen Xiao ◽

Ni Zhu ◽

Cong Wei ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Bone Marrow ◽

Endothelial Cells ◽

Mesenchymal Stem Cells ◽

Tumor Cells ◽

Vascular Endothelial Cells ◽

Adipogenic Differentiation ◽

Target Cells ◽

Vascular Endothelial

Protein tyrosine phosphatases (PTPs) act as key regulators in various cellular processes such as proliferation, differentiation, and migration. Our previous research demonstrated that non-receptor-typed PTP21 (PTPN21), a member of the PTP family, played a critical role in the proliferation, cell cycle, and chemosensitivity of acute lymphoblastic leukemia cells. However, the role of PTPN21 in the bone marrow microenvironment has not yet been elucidated. In the study, we explored the effects of PTPN21 on human bone marrow-derived mesenchymal stem cells (BM-MSCs) via lentiviral-mediated overexpression and knock-down of PTPN21 in vitro. Overexpressing PTPN21 in BM-MSCs inhibited the proliferation through arresting cell cycle at the G0 phase but rendered them a higher osteogenic and adipogenic differentiation potential. In addition, overexpressing PTPN21 in BM-MSCs increased their senescence levels through upregulation of P21 and P53 and dramatically changed the levels of crosstalk with their typical target cells including immunocytes, tumor cells, and vascular endothelial cells. BM-MSCs overexpressing PTPN21 had an impaired immunosuppressive function and an increased capacity of recruiting tumor cells and vascular endothelial cells in a chemotaxis transwell coculture system. Collectively, our data suggested that PTPN21 acted as a pleiotropic factor in modulating the function of human BM-MSCs.

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