title: The anti-inflammatory and antibacterial basis of human omental defense: selective expression of cytokines and antimicrobial peptides.
abstract: BACKGROUND
  The wound healing properties of the human omentum are well known and have extensively been exploited clinically. However, the underlying mechanisms of these effects are not well understood. We hypothesize that the omentum tissue promotes wound healing via modulation of anti-inflammatory pathways, and because the omentum is rich in adipocytes, the adipocytes may modulate the anti-inflammatory response. Factors released by human omentum may affect healing, inflammation and immune defense.
  
  
  METHODS
  Six human omentum tissues (non obese, free from malignancy, and any other systemic disorder) were obtained during diagnostic laparoscopies having a negative outcome. Healthy oral mucosa (obtained from routine oral biopsies) was used as control. Cultured adipocytes derived from human omentum were exposed to lipopolysaccharide (LPS) (1-50 ng/mL) for 12-72 hours to identify the non-cytotoxic doses. Levels of expression (mRNA and protein) were carried out for genes associated with pro- and anti-inflammatory cytokine responses and antibacterial/antimicrobial activity using qRT-PCR, western blotting, and cell-based ELISA assays.
  
  
  RESULTS
  The study shows significant higher levels of expression (mRNA and protein) of several specific cytokines, and antibacterial peptides in the omentum tissues when compared to oral sub-mucosal tissues. In the validation studies, primary cultures of adipocytes, derived from human omentum were exposed to LPS (5 and 10 ng/mL) for 24 and 48 h. The altered expressions were more pronounced in cultured adipocytes cells when exposed to LPS as compared to the omentum tissue.
  
  
  CONCLUSIONS
  Perhaps, this is the first report that provides evidence of expressional changes in pro- and anti-inflammatory cytokines and antibacterial peptides in the normal human omentum tissue as well as adipocytes cultured from this tissue. The study provides new insights on the molecular and cellular mechanisms of healing and defense by the omentum, and suggests the potential applicability of cultured adipocytes derived from the omentum for future therapeutic applications.
authors.affiliation: Department of Surgical Gastroenterology, Erstwhile KG Medical College, CSM Medical University, Lucknow, India.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Chandra
authors.forename: Ritesh Kumar
authors.initials: RK
authors.lastname: Srivastava
authors.forename: Mahendra Pratap
authors.initials: MP
authors.lastname: Kashyap
authors.forename: Raj
authors.initials: R
authors.lastname: Kumar
authors.forename: Rajeshwar Nath
authors.initials: RN
authors.lastname: Srivastava
authors.forename: Aditya Bhushan
authors.initials: AB
authors.lastname: Pant
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000893:Anti-Inflammatory Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D009852:Omentum / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D023181:Antimicrobial Cationic Peptides; D016207:Cytokines; D008070:Lipopolysaccharides; D012333:RNA, Messenger