title: A thermoreversible polymer mediates controlled release of glial cell line-derived neurotrophic factor to enhance kidney regeneration.
abstract: Previously, we reported that human mesenchymal stem cells (hMSCs) that were cultivated in growing embryos differentiated in an appropriate developmental milieu, thereby facilitating the development of a functional renal unit. However, this approach required transfection with an adenovirus that expressed glial cell line-derived neurotrophic factor (GDNF) to enhance the development of hMSC-derived renal tissue, and safety issues restrict the clinical use of such viral vectors. To circumvent this problem, we tested an artificial polymer as a means to diffuse GDNF. This GDNF-polymer, which exists in liquid form at 4 degrees C but becomes a hydrogel upon heating to 37 degrees C, was used as a thermoreversible switch, allowing the injection of hMSCs at low viscosity using a mouth pipette, with subsequent slow diffusion of GDNF as it solidified. The polymer, which was dissolved in a solution of GDNF at 4 degrees C and then maintained at 37 degrees C, acted as a diffuser of GDNF for more than 48 h. LacZ-transfected hMSCs and the GDNF-polymer (at 4 degrees C) were placed in the nephrogenic sites of growing rat embryos that were maintained at 37 degrees C. Forty-eight hours later, the resultant kidney anlagen were dissected out and allowed to continue developing for 6 days in vitro. Whole-organ X-Gal staining and fluorescence activated cell sorter analysis showed that the number of hMSC-derived cells was significantly increased in developed anlagen that have been generated from hMSCs plus GDNF-polymer compared with those from hMSCs plus GDNF-containing medium and was comparable to those from adenovirus-transfected hMSCs. These findings suggest that the GDNF-polymer can be used as a diffuser of GDNF for kidney organogenesis.
authors.affiliation: Project Laboratory for Kidney Regeneration, Institute of DNA Medicine, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Yousof
authors.initials: Y
authors.lastname: Gheisari
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokoo
authors.forename: Kei
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Akira
authors.initials: A
authors.lastname: Fukui
authors.forename: Naomi
authors.initials: N
authors.lastname: Sugimoto
authors.forename: Toya
authors.initials: T
authors.lastname: Ohashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kawamura
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Hosoya
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D019556:COS Cells; D002454:Cell Differentiation; D002522:Chlorocebus aethiops; D005260:Female; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000008:administration & dosage*; D007267:Injections; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011109:Polymethacrylic Acids / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D051437:Renal Insufficiency / Q000628:therapy*; D055471:Thermal Diffusion
chemical_list: C495039:GDNF protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D011109:Polymethacrylic Acids; C084450:poly(N-isopropylacrylamide-co-butyl methacrylate); D011092:Polyethylene Glycols