Project description:Human pericytes demonstrate multilineage differentiation potential, and their descendants participate in tissue homeostasis and repair. Increasing evidence from developmental biology and tissue engineering suggest that regional specification by tissue of origin exists among human pericytes. Here, we sought to define the differentiation of CD146+ human pericytes from skeletal and soft tissue sources. Uncultured CD146+CD31-CD45- pericytes were derived by fluorescent activated cell sorting from human periosteum, adipose, or dermal tissue. Periosteal CD146+CD31-CD45- cells retained canonical features of pericytes, including cell surface marker expression, multilineage differentiation potential, and paracrine induced tubulogenesis. Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis, while soft tissue pericytes did not in vitro or in vivo. Microarray analysis demonstrated substantive differences between periosteal pericytes in comparison to their soft tissue pericyte counterparts. In sum, skeletal and soft tissue pericytes differ in their relative lineage differentiation potential and ability to form bone. Human tissues were microdissected, digested, and FACS sorted to derived a CD146+CD31-CD45- pericyte population, and cells were expanded in standard growth medium (DMEM, 10% FBS, 1% pen/strep) and nucleic acid isolated at subconfluency
Project description:Human pericytes demonstrate multilineage differentiation potential, and their descendants participate in tissue homeostasis and repair. Increasing evidence from developmental biology and tissue engineering suggest that regional specification by tissue of origin exists among human pericytes.Here, we sought to define the differentiation of CD146+ human pericytes from skeletal and soft tissue sources. Uncultured CD146+CD31-CD45- pericytes were derived by fluorescent activated cell sorting from human periosteum, adipose, or dermal tissue. Periosteal CD146+CD31-CD45- cells retained canonical features of pericytes, including cell surface marker expression, multilineage differentiation potential, and paracrine induced tubulogenesis. Periosteal pericytes demonstrated a striking tendency to undergo osteoblastogenesis, while soft tissue pericytes did not in vitro or in vivo. Microarray analysis demonstrated enrichment in CXCR4 and BMP signaling among periosteal pericytes in comparison to their soft tissue pericyte counterparts. Signaling pathway manipulation of CXCR4 among soft tissue pericytes led to an increase in osteoblastogenesis and bone formation. In sum, skeletal and soft tissue pericytes differ in their relative lineage differentiation potential and ability to form bone. Plasticity exists, however, and manipulation of CXCR4 signaling pathway may ‘coax’ a soft tissue pericyte toward an osteoblastogenic cell fate.
Project description:Pericytes derived from skin dermis can substantially enhance the short-term tissue-regenerative capacity of human epidermal cells already committed to differentiation; they also display both phenotypic and functional properties of mesenchymal stem cells. In this microarray analysis, we compared the gene expression profile of dermal pericytes to that of the remaining dermal cells of neonatal human foreskin. Experiment Overall Design: Human neonatal foreskin was digested overnight in dispase II at 4°C to separate the epidermis from the dermis. Subsequently the dermis was digested for 1-2 hours at 37°C in a mixed dispase and collagenase solution and then fractionated into two populations, i.e. pericytes (HD-1bri) and the remaining dermal cells (HD-1dim), on the basis of differential VLA-1 expression using fluorescence-activated cell sorting. Total RNA from 15,000 cells of each population was extracted from 4 independent replicate sorts. mRNAs were amplified using a T7-primer-based-2-round linear RNA amplification protocol (GeneChip Two-Cycle cDNA synthesis kit). Fragmented and biotin-labelled cRNA from each individual sample was hybridised to Affymetrix HG-U133 plus 2.0 arrays and scanned on a Affymetrix GeneChip scanner. Probe intensities were RMA normalized and log2-transformed expression values were compared using moderated t statistics to quantify differences between individual samples.
Project description:Mesenchymal stromal cells (MSCs) are cultured cells that can give rise to mature mesenchymal cells under appropriate conditions, and secrete a number of biologically relevant molecules that may play an important role in regenerative medicine. Evidence indicates that pericytes (PCs) correspond to mesenchymal stem cells in vivo and can give rise to MSCs when cultured, but a comparison between the gene expression profiles of cultured PCs (cPCs) and MSCs is lacking. We have devised a novel methodology to isolate PCs from human adipose tissue, and compared cPCs to MSCs obtained through traditional methods. Freshly isolated PCs expressed CD34, CD140b, and CD271 on their surface, but not CD146. Both MSCs and cPCs were able to differentiate along mesenchymal pathways in vitro, displayed an essentially identical surface immunophenotype, and exhibited the ability to suppress CD3+ lymphocyte proliferation in vitro. Microarray expression data of cPCs and MSCs formed a single cluster among other cell types. Further analyses showed that the gene expression profiles of cPCs and MSCs are extremely similar, although MSCs differentially expressed endothelial cell-specific transcripts. These results confirm, using the power of transcriptomic analysis, that PCs give rise to MSCs, and suggest that low levels of endothelial cells may persist in MSC cultures established using traditional protocols. Highly purified human adipose-tissue pericytes (AT3G5Cs) were isolated based on the expression of the antigen detected by the 3G5 antibody, lack of expression of CD31, and ability to adhere to tissue-cultured plastic whithin a short time. The in vitro properties of cultured AT3G5Cs were compared to those of adipose tissue mesenchymal stromal cells (ATMSCs) obtained through traditional methods. Gene expression profiles of cultured AT3G5Cs (n = 3 different biological samples) and ATMSCs (n = 3 different biological samples) were compared to each other by statistical analyses. Gene expression profiles of cultured AT3G5Cs and ATMSCs were compared to those of other cell types by clustering analyses.
Project description:The objective of this array was to determine the global gene expression profile of human placental pericytes for comparison with other publicly available arrays of pericytes and mesenchymal stromal cells isolated from various human tissues. Pericytes are critical cellular components of the microvasculature that play a major role in vascular development and pathologies, yet their study has been hindered by lack of a standardized method for their isolation and growth. Here we report a method for culturing human pericytes from a readily available tissue source, placenta, and provide a thorough characterization of resultant cell populations. We developed an optimized protocol for obtaining pericytes by outgrowth from microvessel fragments recovered after enzymatic digestion of human placental tissue. We characterized outgrowth populations by immunostaining, by gene expression analysis, and by functional evaluation of cells implanted in vivo. Our approach yields human pericytes that may be serially expanded in culture and that uniformly express the cellular markers NG2, CD90, CD146, α-SMA, and PDGFR-β, but lack markers of smooth muscle cells, endothelial cells, and leukocytes. When co-implanted with human endothelial cells into C.B-17 SCID/bg mice, human pericytes invest and stabilize developing human endothelial cell-lined microvessels. We conclude that our method for culturing pericytes from human placenta results in the expansion of functional pericytes that may be used to study a variety of questions related to vascular biology. Total RNA from three different pericyte isolations at subculture 1 was collected and examined for relative gene expression.
Project description:The objective of this array was to determine the global gene expression profile of human placental pericytes for comparison with other publicly available arrays of pericytes and mesenchymal stromal cells isolated from various human tissues. Pericytes are critical cellular components of the microvasculature that play a major role in vascular development and pathologies, yet their study has been hindered by lack of a standardized method for their isolation and growth. Here we report a method for culturing human pericytes from a readily available tissue source, placenta, and provide a thorough characterization of resultant cell populations. We developed an optimized protocol for obtaining pericytes by outgrowth from microvessel fragments recovered after enzymatic digestion of human placental tissue. We characterized outgrowth populations by immunostaining, by gene expression analysis, and by functional evaluation of cells implanted in vivo. Our approach yields human pericytes that may be serially expanded in culture and that uniformly express the cellular markers NG2, CD90, CD146, α-SMA, and PDGFR-β, but lack markers of smooth muscle cells, endothelial cells, and leukocytes. When co-implanted with human endothelial cells into C.B-17 SCID/bg mice, human pericytes invest and stabilize developing human endothelial cell-lined microvessels. We conclude that our method for culturing pericytes from human placenta results in the expansion of functional pericytes that may be used to study a variety of questions related to vascular biology.
Project description:Mesenchymal stromal cells (MSCs) are cultured cells that can give rise to mature mesenchymal cells under appropriate conditions, and secrete a number of biologically relevant molecules that may play an important role in regenerative medicine. Evidence indicates that pericytes (PCs) correspond to mesenchymal stem cells in vivo and can give rise to MSCs when cultured, but a comparison between the gene expression profiles of cultured PCs (cPCs) and MSCs is lacking. We have devised a novel methodology to isolate PCs from human adipose tissue, and compared cPCs to MSCs obtained through traditional methods. Freshly isolated PCs expressed CD34, CD140b, and CD271 on their surface, but not CD146. Both MSCs and cPCs were able to differentiate along mesenchymal pathways in vitro, displayed an essentially identical surface immunophenotype, and exhibited the ability to suppress CD3+ lymphocyte proliferation in vitro. Microarray expression data of cPCs and MSCs formed a single cluster among other cell types. Further analyses showed that the gene expression profiles of cPCs and MSCs are extremely similar, although MSCs differentially expressed endothelial cell-specific transcripts. These results confirm, using the power of transcriptomic analysis, that PCs give rise to MSCs, and suggest that low levels of endothelial cells may persist in MSC cultures established using traditional protocols.
Project description:Dermal white adipose tissue (dWAT) is one of the peripheral tissues directly adjacent to hair follicle(HF) and acts as critical macroenvironmental niche of HF. dWAT directly contribute to HF aging by paracrine signals secretion. However, the altered interrelationship between dWAT and HF with aging has not been thoroughly understood
Project description:Analysis of Nestin-GFP+ pericytes flow sorted from 3-day-old mouse cutaneous adipose tissue, comparing controls with wild type PDGFRa, and mutants with increased PDGFRa signaling driven by a Cre/lox-inducible D842V knockin mutation in the PDGFRa kinase domain. The control cells have adipogenic properties in vitro or when transplanted subcutaneously into recipient mice. The D842V mutant cells show altered behavior in the same assays, with poor adipogenic differentiation but a propensity to transition into profibrotic cells that secrete collagen