title: Human amnion epithelial cells rescue cell death via immunomodulation of microglia in a mouse model of perinatal brain injury.
abstract: Human amnion epithelial cells (hAECs) are clonogenic and have been proposed to reduce inflammatory-induced tissue injury. Perturbation of the immune response is implicated in the pathogenesis of perinatal brain injury; modulating this response could thus be a novel therapy for treating or preventing such injury. The immunomodulatory properties of hAECs have been shown in other animal models, but a detailed investigation of the effects on brain immune cells following injury has not been undertaken. Here, we investigate the effects of hAECs on microglia, the first immune responders to injury within the brain.
  
  
  
  We generated a mouse model combining neonatal inflammation and perinatal hyperoxia, both of which are risk factors associated with perinatal brain injury. On embryonic day 16 we administered lipopolysaccharide (LPS), or saline (control), intra-amniotically to C57Bl/6 J mouse pups. On postnatal day (P)0, LPS pups were placed in hyperoxia (65% oxygen) and control pups in normoxia for 14 days. Pups were given either hAECs or saline intravenously on P4.
  
  
  
  At P14, relative to controls, LPS and hyperoxia pups had reduced body weight, increased density of apoptotic cells (TUNEL) in the cortex, striatum and white matter, astrocytes (GFAP) in the white matter and activated microglia (CD68) in the cortex and striatum, but no change in total microglia density (Iba1). hAEC administration rescued the decreased body weight and reduced apoptosis and astrocyte areal coverage in the white matter, but increased the density of total and activated microglia. We then stimulated primary microglia (CD45lowCD11b+) with LPS for 24 h, followed by co-culture with hAEC conditioned medium for 48 h. hAEC conditioned medium increased microglial phagocytic activity, decreased microglia apoptosis and decreased M1 activation markers (CD86). Stimulating hAECs for 24 h with LPS did not alter release of cytokines known to modulate microglia activity.
  
  
  
  These data demonstrate that hAECs can directly immunomodulate brain microglia, probably via release of trophic factors. This observation offers promise that hAECs may afford therapeutic utility in the management of perinatal brain injury.
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia. bryan.leaw@hudson.org.au.
authors.forename: Bryan
authors.identifier: 0000-0003-2113-2590
authors.initials: B
authors.lastname: Leaw
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhu
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Jean
authors.initials: J
authors.lastname: Tan
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Ruth
authors.initials: R
authors.lastname: Muljadi
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
authors.forename: Mohamed I
authors.initials: MI
authors.lastname: Saad
authors.affiliation: Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, 3168, Australia.
authors.forename: Joanne C
authors.initials: JC
authors.lastname: Mockler
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.|Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, 3168, Australia.
authors.forename: Euan M
authors.initials: EM
authors.lastname: Wallace
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.|Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, 3168, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Lim
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.|Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, 3168, Australia.|School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, 3083, Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Tolcos
mesh_terms: D000650:Amnion / Q000166:cytology* / Q000276:immunology; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000235:genetics / Q000276:immunology; D051940:B7-2 Antigen / Q000235:genetics / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D001930:Brain Injuries / Q000235:genetics / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000276:immunology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology / Q000637:transplantation*; D005260:Female; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics / Q000276:immunology; D006801:Humans; D018496:Hyperoxia / Q000235:genetics / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D056747:Immunomodulation; D008070:Lipopolysaccharides / Q000008:administration & dosage; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins / Q000235:genetics / Q000276:immunology; D017628:Microglia / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D018743:Perinatal Care; D011247:Pregnancy; D061251:Primary Cell Culture; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D051940:B7-2 Antigen; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D017077:Culture Media, Conditioned; D005904:Glial Fibrillary Acidic Protein; D008070:Lipopolysaccharides; D008840:Microfilament Proteins; C491049:Aif1 protein, mouse; C081026:CD68 protein, mouse; D000097382:CD68 Molecule; C497965:Cd86 protein, mouse; C528900:glial fibrillary astrocytic protein, mouse
keywords: Amnion cell; Brain development; Cell therapy; Hyperoxia; Immunotherapy; Inflammation; Microglia; Perinatal brain injury