title: Platelet-rich plasma greatly potentiates insulin-induced adipogenic differentiation of human adipose-derived stem cells through a serine/threonine kinase Akt-dependent mechanism and promotes clinical fat graft maintenance.
abstract: The potential plasticity and therapeutic utility in tissue regeneration of human adipose-derived stem cells (ASCs) isolated from adult adipose tissue have recently been highlighted. The use of autologous platelet-rich plasma (PRP) represents an alternative strategy in regenerative medicine for the local release of multiple endogenous growth factors. Here we investigated the signaling pathways and effects of PRP and human recombinant insulin on proliferation and adipogenic differentiation of ASCs in vitro. PRP stimulated proliferation (EC(50) = 15.3 ± 1.3% vol/vol), whereas insulin's effect was the opposite (IC(50) = 3.0 ± 0.5 μM). Although PRP alone did not increase adipogenesis, in association with insulin it prevented ASC proliferative arrest, greatly enhanced intracytoplasmic lipid accumulation, strongly increased serine/threonine kinase Akt phosphorylation and mouse monoclonal anti-sterol regulatory element binding protein-1 accumulation, and downregulated Erk-1 activity; adipogenic effects were markedly prevented by the Akt inhibitor wortmannin. PRP with insulin synergistically upregulated fibroblast growth factor receptor (FGFR) and downregulated epidermal growth factor receptor (ErbB) expression; moreover, PRP in association prevented insulin-induced insulin-like growth factor-1 receptor and insulin receptor downregulation. The inhibition of FGFR-1, epidermal growth factor receptor (EGFR), and epidermal growth factor receptor-2 (ErbB2) activity reduced ASC proliferation, but only that of FGFR-1 reduced adipogenesis and Akt phosphorylation, whereas the ErbB2 inhibition effects were the opposite. However, EGFR activity was needed for ErbB2-mediated inhibition of ASC adipogenesis. Clinically, the injection of insulin further ameliorated patients' 1-year PRP-induced fat graft volume maintenance and contour restoring. Our results ascertain that PRP in association with insulin greatly potentiates adipogenesis in human ASCs through a FGFR-1 and ErbB2-regulated Akt mechanism. The ameliorated clinical fat graft maintenance suggests additional useful translational applications of combined PRP-insulin treatment in regenerative medicine.
authors.affiliation: Plastic Surgery Department, Tor Vergata University, Rome, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Cervelli
authors.forename: Maria G
authors.initials: MG
authors.lastname: Scioli
authors.forename: Pietro
authors.initials: P
authors.lastname: Gentile
authors.forename: Elena
authors.initials: E
authors.lastname: Doldo
authors.forename: Elena
authors.initials: E
authors.lastname: Bonanno
authors.forename: Luigi G
authors.initials: LG
authors.lastname: Spagnoli
authors.forename: Augusto
authors.initials: A
authors.lastname: Orlandi
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D000273:Adipose Tissue / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D017209:Apoptosis; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005434:Flow Cytometry; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010766:Phosphorylation / Q000187:drug effects; D053657:Platelet-Rich Plasma / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D016222:Fibroblast Growth Factor 2; D007004:Hypoglycemic Agents; D007328:Insulin; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; C508053:ERBB2 protein, human