Immortalized multipotent pericytes derived from the vasa vasorum in the injured vasculature. A cellular tool for studies of vascular remodeling and regeneration

Abstract

Adventitial microvessels, vasa vasorum in the vessel walls, have an active role in the vascular remodeling, although its mechanisms are still unclear. It has been reported that microvascular pericytes (PCs) possess mesenchymal plasticity. Therefore, microvessels would serve as a systemic reservoir of stem cells and contribute to the tissues remodeling. However, most aspects of the biology of multipotent PCs (mPCs), in particular of pathological microvessels are still obscure because of the lack of appropriate methods to detect and isolate these cells. In order to examine the characteristics of mPCs, we established immortalized cells residing in adventitial capillary growing at the injured vascular walls. We recently developed in vivo angiogenesis to observe adventitial microvessels using collagen-coated tube (CCT), which also can be used as an adventitial microvessel-rich tissue. By using the CCT, CD146-or NG2-positive cells were isolated from the adventitial microvessels in the injured arteries of mice harboring a temperature-sensitive SV40 T-antigen gene. Several capillary-derived endothelial cells (cECs) and PCs (cPCs) cell lines were established. cECs and cPCs maintain a number of key endothelial and PC features. Co-incubation of cPCs with cECs formed capillary-like structure in Matrigel. Three out of six cPC lines, termed capillary mPCs demonstrated both mesenchymal stem cell-and neuronal stem cell-like phenotypes, differentiating effectively into adipocytes, osteoblasts, as well as schwann cells. mPCs differentiated to ECs and PCs, and formed capillary-like structure on their own. Transplanted DsRed-expressing mPCs were resident in the capillary and muscle fibers and promoted angiogenesis and myogenesis in damaged skeletal muscle. Adventitial mPCs possess transdifferentiation potential with unique phenotypes, including the reconstitution of capillary-like structures. Their phenotype would contribute to the pathological angiogenesis associated with vascular remodeling. These cell lines also provide a reproducible cellular tool for high-throughput studies on angiogenesis, vascular remodeling, and regeneration as well.

Brain pericytes serve as microglia-generating multipotent vascular stem cells following ischemic stroke

“…Why do reactive PCs acquire hematopoietic potential? Although adult brain PCs lack angiogenic properties under normal conditions, multipotent PCs do exhibit vasculogenic traits [ 40 , 43 , 55 ]. In addition, APCs expressed both PC (PDGFRβ, NG2) and hematopoietic stem cell (CD34) markers [ 40 , 43 , 55 ].…”

“…Although adult brain PCs lack angiogenic properties under normal conditions, multipotent PCs do exhibit vasculogenic traits [ 40 , 43 , 55 ]. In addition, APCs expressed both PC (PDGFRβ, NG2) and hematopoietic stem cell (CD34) markers [ 40 , 43 , 55 ]. Furthermore, we recently demonstrated that following ischemia/hypoxia, adult brain PCs display a complex angioblastic phenotype that includes the expression of various hematopoietic stem cell markers such as CD34 and CD144 in addition to their original mesenchymal properties [ 20 ].…”

Pericyte-Specific Ninjurin1 Deletion Attenuates Vessel Maturation and Blood Flow Recovery in Hind Limb Ischemia

“…For confirmation of pericyte-specific knockout of Ninj1 gene, Ninj1 expression in NG2 + cells was estimated by real-time polymerase chain reaction. 16 , 18 …”

“…Capillary derived immortalized ECs/pericytes or primary pericytes isolated form GFP (green fluorescent protein)–expressing mouse were used for in vitro experiments as described previously. 18 Briefly, skeletal muscle stroma cells were prepared from gastrocnemius muscle tissues of Ninj1-knockout mouse (as described above) or GFP-expressing mice, and NG2 + pericytes were isolated from skeletal muscle stroma cells by using a fluorescence magnetic activated cell sorting or magnetic activated cell sorting systems with anti-NG2 antibody–conjugated microbeads. For label the living cells, the immortalized cells were infected with a retrovirus harboring the GFP or DsRed gene.…”

Pharmaceutical efficacy of human epiphyseal chondrocytes with differential replication numbers for cellular therapy products

“…Chondrocytes in culture have an ability to generate cartilage in vivo, and can be a tool to simulate developmental process. Our previous study demonstrated that human infant epiphyseal chondrocytes can also simulate developmental process of epiphyseal cartilage as well as other cell types [2, 3]. Chondrocytes in culture regenerate the cartilaginous tissue by a short-term implantation in vivo and exhibited enchondral ossification after a longer period.…”