title: Interleukin-10 regulates the fetal hyaluronan-rich extracellular matrix via a STAT3-dependent mechanism.
abstract: BACKGROUND
  The midgestational fetus is capable of regenerative healing. We have recently demonstrated a novel role for the anti-inflammatory cytokine interleukin 10 (IL-10) as a regulator of hyaluronan (HA) in the extracellular matrix. The signaling pathway of IL-10 has been studied in monocytes but is unknown in dermal fibroblasts. We hypothesized IL-10 signals through its primary receptor, IL-10R1, to activate STAT3, resulting in HA synthesis.
  
  
  METHODS
  Murine midgestational (E14.5) fetal fibroblasts were evaluated in vitro. Pericellular matrix was quantified using a particle exclusion assay. STAT3 levels and cellular localization were evaluated by Western blot/band densitometry and immunocytochemistry/confocal microscopy. HA levels were quantified by enzyme-linked immunosorbent assay. The effects of IL-10R1 signal blockade by a neutralizing antibody and STAT3 inhibition were evaluated. An ex vivo midgestation fetal forearm culture incisional wound model in control and transgenic IL-10-/- mice was used to evaluate the role of STAT3 on the extracellular matrix.
  
  
  RESULTS
  Fetal fibroblasts produce a robust hyaluronan-rich pericellular matrix that is IL-10R1 and STAT3 dependent. Inhibition of IL-10R1 signaling results in decreased phosphorylated STAT3 levels and inhibition of nuclear localization. Inhibition of STAT3 results in decreased HA production. At day 3, midgestation fetal wounds have efficient re-epithelialization, which is significantly slowed in IL-10-/- wounds at the same gestation and with inhibition of STAT3.
  
  
  CONCLUSIONS
  Our data demonstrate that IL-10 regulates HA synthesis through its primary receptor IL-10R1 and STAT3 activation. This supports a novel nonimmunoregulatory mechanism of IL-10 in its role in fetal regenerative wound healing.
authors.affiliation: The Center for Molecular Fetal Therapy, Division of Pediatric, Thoracic and General Surgery, Cincinnati Children's Hospital and the University of Cincinnati College of Medicine, Cincinnati, Ohio 45229-3039, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: King
authors.forename: Swathi
authors.initials: S
authors.lastname: Balaji
authors.forename: Emily
authors.initials: E
authors.lastname: Marsh
authors.forename: Louis D
authors.initials: LD
authors.lastname: Le
authors.forename: Aimen F
authors.initials: AF
authors.lastname: Shaaban
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Crombleholme
authors.forename: Sundeep G
authors.initials: SG
authors.lastname: Keswani
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005865:Gestational Age; D006820:Hyaluronic Acid / Q000096:biosynthesis / Q000378:metabolism*; D056747:Immunomodulation / Q000502:physiology; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism*; D053709:Interleukin-10 Receptor alpha Subunit / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010766:Phosphorylation / Q000502:physiology; D011247:Pregnancy; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology
chemical_list: C556062:IL10 protein, mouse; D053709:Interleukin-10 Receptor alpha Subunit; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D016753:Interleukin-10; D006820:Hyaluronic Acid
keywords: Extracellular matrix; Fetal wound healing; Hyaluronan; IL-10; STAT3