title: PGC-1α expression is increased in leukocytes in experimental acute pancreatitis.
abstract: Severe acute pancreatitis (AP) induces a systemic inflammatory disease that is responsible for high mortality rates, particularly when it is complicated by infection. Therefore, differentiating sepsis from the systemic inflammation caused by AP is a serious clinical challenge. Considering the high metabolic rates of leukocytes in response to stress induced by infection, we hypothesized that the transcription coactivator peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1α), a master regulator of mitochondrial biogenesis and function, would be distinctly expressed during inflammation or infection and, therefore, could constitute a useful marker to differentiate between these two conditions. Rats were subjected to injection of taurocholate into the main pancreatic duct, which caused a severe AP with high amylase levels and white blood cell counts. In these animals, a marked increase in PGC-1α mRNA levels in circulating leukocytes was observed 48 h after the surgical procedure, a time when bacteremia is present. Antibiotic treatment abolished PGC-1α up-regulation. Moreover, PGC-1α expression was higher in peritoneal macrophages from animals subjected to a bacterial insult (cecal ligation and puncture) than in animals with AP. In isolated macrophages, we also observed that PGC-1α expression is more prominent in the presence of a phagocytic stimulus (zymosan) when compared to lipopolysaccharide-induced aseptic inflammation. Moreover, abolishing PGC-1α expression with antisense oligos impaired zymosan phagocytosis. Together, these findings suggest that PGC-1α is differentially expressed during aseptic inflammation and infection and that it is necessary for adequate phagocytosis. These results could be useful in developing new tests for differentiating infection from inflammation for clinical purposes in patients with AP.
authors.affiliation: Emergency Medicine Department, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Arnaldo, 455, Room 3189, LIM51, 01246-903, São Paulo, SP, Brazil.
authors.forename: Flávia
authors.initials: F
authors.lastname: Llimona
authors.forename: Thais Martins
authors.initials: TM
authors.lastname: de Lima
authors.forename: Ana Iochabel
authors.initials: AI
authors.lastname: Moretti
authors.forename: Mariana
authors.initials: M
authors.lastname: Theobaldo
authors.forename: Jose
authors.initials: J
authors.lastname: Jukemura
authors.forename: Irineu Tadeu
authors.initials: IT
authors.lastname: Velasco
authors.forename: Marcel C C
authors.initials: MC
authors.lastname: Machado
authors.forename: Heraldo Possolo
authors.initials: HP
authors.lastname: Souza
mesh_terms: D000208:Acute Disease; D000818:Animals; D002432:Cecum / Q000601:surgery; D005786:Gene Expression Regulation; D007249:Inflammation / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D010195:Pancreatitis / Q000139:chemically induced / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010587:Phagocytosis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018805:Sepsis / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D016376:Oligonucleotides, Antisense; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D012333:RNA, Messenger; D014157:Transcription Factors