Browsing by Subject "REGENERATION"

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    A new non-enzymatic method for isolating human intervertebral disc cells preserves the phenotype of nucleus pulposus cells.
    (Cytotechnology, 2014-12) Tang, Xinyan; Richardson, William J; Fitch, Robert D; Brown, Christopher R; Isaacs, Robert E; Chen, Jun
    Cells isolated from intervertebral disc (IVD) tissues of human surgical samples are one of potential sources for the IVD cellular therapy. The purpose of this study was to develop a new non-enzymatic method, "tissue incubation", for isolating human IVD cells. The IVD tissues of annulus fibrosus (AF) and nucleus pulposus (NP) were incubated separately in tissue culture flasks with culture medium. After 7-10 days incubation, cells were able to migrate out of IVD tissues and proliferate in vitro. After 3-4 weeks culture, expanded cells were harvested by trypsinization, and the remaining tissues were transferred to a new flask for another round of incubation. The molecular phenotype of IVD cells from juvenile and adult human samples was evaluated by both flow cytometry analysis and immunocytochemical staining for the expression of protein markers of NP cells (CD24, CD54, CD239, integrin α6 and laminin α5). Flow cytometry confirmed that both AF and NP cells of all ages positively expressed CD54 and integrin α6, with higher expression levels in NP cells than in AF cells for the juvenile group sample. However, CD24 expression was only found in juvenile NP cells, and not in AF or older disc cells. Similar expression patterns for NP markers were also confirmed by immunocytochemistry. In summary, this new non-enzymatic tissue incubation method for cell isolation preserves molecular phenotypic markers of NP cells and may provide a valuable cell source for the study of NP regeneration strategies.
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    Macrophage cells secrete factors including LRP1 that orchestrate the rejuvenation of bone repair in mice.
    (Nature communications, 2018-12-05) Vi, Linda; Baht, Gurpreet S; Soderblom, Erik J; Whetstone, Heather; Wei, Qingxia; Furman, Bridgette; Puviindran, Vijitha; Nadesan, Puviindran; Foster, Matthew; Poon, Raymond; White, James P; Yahara, Yasuhito; Ng, Adeline; Barrientos, Tomasa; Grynpas, Marc; Mosely, M Arthur; Alman, Benjamin A
    The pace of repair declines with age and, while exposure to a young circulation can rejuvenate fracture repair, the cell types and factors responsible for rejuvenation are unknown. Here we report that young macrophage cells produce factors that promote osteoblast differentiation of old bone marrow stromal cells. Heterochronic parabiosis exploiting young mice in which macrophages can be depleted and fractionated bone marrow transplantation experiments show that young macrophages rejuvenate fracture repair, and old macrophage cells slow healing in young mice. Proteomic analysis of the secretomes identify differential proteins secreted between old and young macrophages, such as low-density lipoprotein receptor-related protein 1 (Lrp1). Lrp1 is produced by young cells, and depleting Lrp1 abrogates the ability to rejuvenate fracture repair, while treating old mice with recombinant Lrp1 improves fracture healing. Macrophages and proteins they secrete orchestrate the fracture repair process, and young cells produce proteins that rejuvenate fracture repair in mice.