title: Human mesenchymal stem/stromal cells suppress spinal inflammation in mice with contribution of pituitary adenylate cyclase-activating polypeptide (PACAP).
abstract: BACKGROUND
  Adult human mesenchymal stem/stromal cells (hMSCs) from bone marrow have been reported to exhibit beneficial effects on spinal cord injury (SCI). A neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP) is known to decrease neuronal cell death and inflammatory response after ischemia, SCI, and other neuronal disorders. Recently, we found that expression of the gene for mouse PACAP (Adcyap1) was greater in animals receiving hMSCs with neural injury such as ischemia. However, the association of PACAP with hMSCs to protect nerve cells against neural injuries is still unclear.
  
  
  METHODS
  Wild-type and PACAP-gene-deficient (Adcyap1 (+/-) ) mice were subjected to spinal cord transection, and hMSCs (5 × 10(5) cells) were injected into the intervertebral spinal cord on day 1 post-operation (p.o.). Locomotor activity, injury volume, retention of hMSCs, mouse and human cytokine genes (which contribute to macrophage (MΦ) and microglial activation), and Adcyap1 were evaluated.
  
  
  RESULTS
  hMSCs injected into wild-type mice improved locomotor activity and injury volume compared with vehicle-treated mice. In contrast, non-viable hMSCs injected into wild-type mice, and viable hMSCs injected into Adcyap1 (+/-) mice, did not. Wild-type mice injected with hMSCs exhibited increased Adcyap1 expression, and observed PACAP immunoreaction in neuron-like cells. Gene expression levels for IL-1, tumor necrosis factor α (TNFα), interleukin-10 (IL-10), and transforming growth factor β (TGFβ) decreased, while that for interleukin-4 (IL-4) increased, in hMSC-injected wild-type mice. In contrast, IL-1, TGFβ, and IL-4 gene expression levels were all abolished in hMSC-injected Adcyap1 (+/-) mice on day 7 post-operation. Moreover, the mice-implanted hMSCs increased an alternative activating macrophage/microglial marker, arginase activity. The human gene profile indicated that hMSCs upregulated the gene of IL-4 and growth factors which were reported to enhance Adcyap1 expression. Finally, we demonstrated that hMSCs express human ADCYAP1 and its receptor gene after the inflammation-related interferon-γ (IFNγ) in vitro.
  
  
  CONCLUSIONS
  These results suggest that hMSCs attenuate the deleterious effects of SCI by reducing associated inflammatory responses and enhancing IL-4 production. This effect could be mediated in part by cell-cell cross-talk involving the neuropeptide PACAP.
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. milky-t9@wg8.so-net.ne.jp.|Department of Orthopedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama, Kanagawa, 227-8501, Japan. milky-t9@wg8.so-net.ne.jp.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Tsumuraya
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. taki@med.showa-u.ac.jp.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ohtaki
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. dandansong1202@gmail.com.
authors.forename: Dandan
authors.initials: D
authors.lastname: Song
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. atsushi@med.showa-u.ac.jp.|Department of Orthopedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama, Kanagawa, 227-8501, Japan. atsushi@med.showa-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sato
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. watanabe@med.showa-u.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Watanabe
authors.affiliation: Department of Orthopedic Surgery, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. hiraizum@med.showa-u.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hiraizumi
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. nakamachi@sci.u-toyama.ac.jp.|Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama, 930-8555, Japan. nakamachi@sci.u-toyama.ac.jp.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nakamachi
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. xuzhifang@med.showa-u.ac.jp.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. kdoppy@jikei.ac.jp.|Department of Emergency Medicine, Tokyo Jikei University School of Medicine, 3-25-8 Nishishinnbashi, Minato-ku, Tokyo, 105-8461, Japan. kdoppy@jikei.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Dohi
authors.affiliation: Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan. hasimoto@phs.osaka-u.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hashimoto
authors.affiliation: Department of Orthopedic Surgery, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama, Kanagawa, 227-8501, Japan. atsumi@med.showa-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Atsumi
authors.affiliation: Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan. shioda@med.showa-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shioda
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D064987:Cell- and Tissue-Based Therapy; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000628:therapy*; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008124:Locomotion / Q000502:physiology; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000235:genetics / Q000378:metabolism*; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I / Q000235:genetics / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000150:complications / Q000628:therapy*; D013997:Time Factors
chemical_list: C495402:Adcyap1 protein, mouse; D016207:Cytokines; D008070:Lipopolysaccharides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D007371:Interferon-gamma