title: Utility of telomerase-pot1 fusion protein in vascular tissue engineering.
abstract: While advances in regenerative medicine and vascular tissue engineering have been substantial in recent years, important stumbling blocks remain. In particular, the limited life span of differentiated cells that are harvested from elderly human donors is an important limitation in many areas of regenerative medicine. Recently, a mutant of the human telomerase reverse transcriptase enzyme (TERT) was described, which is highly processive and elongates telomeres more rapidly than conventional telomerase. This mutant, called pot1-TERT, is a chimeric fusion between the DNA binding protein pot1 and TERT. Because pot1-TERT is highly processive, it is possible that transient delivery of this transgene to cells that are utilized in regenerative medicine applications may elongate telomeres and extend cellular life span while avoiding risks that are associated with retroviral or lentiviral vectors. In the present study, adenoviral delivery of pot1-TERT resulted in transient reconstitution of telomerase activity in human smooth muscle cells, as demonstrated by telomeric repeat amplification protocol (TRAP). In addition, human engineered vessels that were cultured using pot1-TERT-expressing cells had greater collagen content and somewhat better performance in vivo than control grafts. Hence, transient delivery of pot1-TERT to elderly human cells may be useful for increasing cellular life span and improving the functional characteristics of resultant tissue-engineered constructs.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Petersen
authors.forename: Thomas
authors.initials: T
authors.lastname: Hitchcock
authors.forename: Akihito
authors.initials: A
authors.lastname: Muto
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Calle
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.forename: Zhaodi
authors.initials: Z
authors.lastname: Gong
authors.forename: Liqiong
authors.initials: L
authors.lastname: Gui
authors.forename: Alan
authors.initials: A
authors.lastname: Dardik
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Bowles
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Counter
authors.forename: Laura E
authors.initials: LE
authors.lastname: Niklason
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000328:Adult; D000818:Animals; D019149:Bioreactors / Q000592:standards; D001808:Blood Vessels / Q000166:cytology / Q000637:transplantation*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics; D003094:Collagen / Q000378:metabolism; D005822:Genetic Vectors / Q000627:therapeutic use; D006085:Graft Survival / Q000235:genetics; D006801:Humans; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000637:transplantation; D051381:Rats; D011923:Rats, Nude; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000627:therapeutic use*; D000089804:Shelterin Complex; D019098:Telomerase / Q000235:genetics / Q000627:therapeutic use*; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000627:therapeutic use*; D023822:Tissue Engineering / Q000379:methods*; D014162:Transfection / Q000379:methods*
chemical_list: C440849:POT1 protein, human; D011993:Recombinant Fusion Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D003094:Collagen; D019098:Telomerase