title: CXCL14 and MCP1 are potent trophic factors associated with cell migration and angiogenesis leading to higher regenerative potential of dental pulp side population cells.
abstract: BACKGROUND
  The release of trophic factors from mesenchymal stem cells (MSCs) is critical for tissue regeneration. A systematic investigation of the regenerative potential of trophic factors from different MSCs, however, has not been performed. Thus, in the present study, the regenerative potential of conditioned medium (CM) from dental pulp, bone marrow, and adipose tissue-derived CD31(-) side population (SP) cells from an individual source was compared in an ectopic tooth transplantation model.
  
  
  METHODS
  The tooth root transplantation in an ectopic site model was used for investigation of the regenerative potential and trophic effects in vivo. Either pulp CD31(-) SP cell populations (1×10(6) cells) at the third to fourth passage or 5 μg/ml of CM from dental pulp, bone marrow, and adipose stem cells from four different individuals were injected into the root with collagen TE. Each root was transplanted subcutaneously in 5-week-old severe combined immunodeficiency mice. Each root with surrounding tissue was harvested for histology on days 7, 21, and 28 and for Western blot analysis and real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis on day 28. Furthermore, the trophic factors responsible for the regenerative potential were identified as the upregulated genes present in pulp CD31(-) SP cells when compared with the genes in both bone marrow and adipose CD31(-) SP cells by using microarray analysis, real-time RT-PCR, and Western blot analysis.
  
  
  RESULTS
  Transplantation of pulp CM yielded increased volume of pulp regeneration, more bromodeoxyuridine (BrdU)-positive migrated cells, and fewer caspase 3-positive cells in the regenerated pulp compared with the others. Pulp CM also demonstrated significantly increased cell migration, anti-apoptosis, and angiogenesis in C2C12 cells. Higher expression of CXCL14 and MCP1 in pulp SP cells suggested candidate trophic factors. The stimulatory effects on both migration and angiogenesis of CXCL14 and MCP1 were demonstrated in vitro. In the regenerated tissue, BrdU-positive migrated cells expressed CXCR4 and CCR2, receptors for CXCL14 and MCP1, respectively.
  
  
  CONCLUSIONS
  The higher regenerative potential of pulp SP cells may be due to potent trophic factors, including CXCL14 and MCP1, which promote migration and angiogenesis.
authors.affiliation: Department of Dental Regenerative Medicine, Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Research Institute, Morioka 7-430, Obu, Aichi, 474-8511, Japan. hys8y9@gmail.com.|Department of Pediatric Dentistry, School of Dentistry, Aichi-Gakuin University suemoridouri 2-11, Nagoya, Aichi, 464-8651, Japan. hys8y9@gmail.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Dental Regenerative Medicine, Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Research Institute, Morioka 7-430, Obu, Aichi, 474-8511, Japan. murakami@ncgg.go.jp.
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Dental Regenerative Medicine, Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Research Institute, Morioka 7-430, Obu, Aichi, 474-8511, Japan. 123d11@dpc.agu.ac.jp.|Department of Gerodontology, School of Dentistry, Aichi-Gakuin University suemoridouri 2-11, Nagoya, Aichi, 464-8651, Japan. 123d11@dpc.agu.ac.jp.
authors.forename: R
authors.initials: R
authors.lastname: Kawamura
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Aichi-Gakuin University suemoridouri 2-11, Nagoya, Aichi, 464-8651, Japan. ryo1685@yahoo.co.jp.
authors.forename: R
authors.initials: R
authors.lastname: Ishizaka
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Aichi-Gakuin University suemoridouri 2-11, Nagoya, Aichi, 464-8651, Japan. fukuta@dpc.aichi-gakuin.ac.jp.
authors.forename: O
authors.initials: O
authors.lastname: Fukuta
authors.affiliation: Department of Dental Regenerative Medicine, Center of Advanced Medicine for Dental and Oral Diseases, National Center for Geriatrics and Gerontology, Research Institute, Morioka 7-430, Obu, Aichi, 474-8511, Japan. misako@ncgg.go.jp.
authors.forename: M
authors.initials: M
authors.lastname: Nakashima
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002465:Cell Movement; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D019743:Chemokines, CXC / Q000235:genetics / Q000378:metabolism*; D003782:Dental Pulp / Q000166:cytology* / Q000502:physiology; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D051379:Mice; D018919:Neovascularization, Physiologic / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration / Q000502:physiology*; D058985:Side-Population Cells / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology
chemical_list: C517518:CXCL14 protein, mouse; D018932:Chemokine CCL2; D019743:Chemokines, CXC