Alveolar macrophage suppression in sepsis is associated with high mobility group box 1 transmigration.
Macrophage dysfunction occurs late in sepsis and is implicated in increased mortality. Interferon gamma (IFN-gamma) stimulates transmigration of high mobility group box 1 (HMGB-1) from the nucleus into cytoplasm of macrophages and subsequent release. Because HMGB-1 release also occurs late, and because one of the actions of HMGB-1 in the nucleus is to enhance transcription factors, we investigated if HMGB-1 transmigration is involved in macrophage suppression in sepsis. Alveolar macrophages were isolated 12 and 24 h from sham controls, cecal ligation and puncture (CLP), and CLP rats given IFN-gamma antibody (1.2 mg/kg, i.v.). All injections were given immediately after surgery. At 12 h, 60% of cells from sham controls had HMGB-1 located primarily in the nucleus, whereas 35% of cells had diffuse staining in both cytoplasm and nucleus. In CLP rats, HMGB-1 was located predominantly in the cytoplasm of 37% of cells, and 48% had diffuse staining, whereas in IFN-gamma antibody (Ab)-treated rats, HMGB-1 was located predominantly in the nucleus of 56% of cells, whereas 32% had diffuse staining. At 24 h, most cells from CLP rats (82%) had HMGB-1 located in the cytoplasm, whereas in contrast, HMGB-1 was located in the nucleus of 80% and 82% of cells from sham control and IFN-gamma Ab-treated rats, respectively. Gene expression of TNF-alpha was not significantly changed 12 h after surgery, but at 24 h, alveolar macrophages from CLP rats had reduced gene expression of TNF-alpha. Interferon gamma Ab treatment prevented the reduction in TNF-alpha gene expression. TNF-alpha release was not altered at 12 h. At 24 h, LPS-stimulated release of TNF-alpha was decreased in macrophages from CLP rats compared with sham controls. Interferon gamma Ab treatment prevented the decrease in LPS-stimulated TNF-alpha release. The results suggest that alveolar macrophage suppression after CLP is associated with HMGB-1 transmigration out of the cell nucleus and provides evidence that intranuclear HMGB-1 may play an integral role in macrophage activation in sepsis.
Pahuja
Madhuri
M
Department of Cell Biology, University of Medicine and Dentistry, NJ-School of Osteopathic Medicine, Stratford, NJ 08084, USA.
Tran
Cindy
C
Wang
Haichao
H
Yin
Kingsley
K
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism* / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins / Q000378:metabolism*; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D016676:Macrophages, Alveolar / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012097:Repressor Proteins / Q000378:metabolism*; D018805:Sepsis / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000906:Antibodies; D024243:HMGB1 Protein; C104200:Hbp1 protein, rat; D006609:High Mobility Group Proteins; D008070:Lipopolysaccharides; D012097:Repressor Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma