HIF-1 mediates pathogenic inflammatory responses to intestinal ischemia-reperfusion injury.
Acute lung injury (ALI) and the development of the multiple organ dysfunction syndrome (MODS) are major causes of death in trauma patients. Gut inflammation and loss of gut barrier function as a consequence of splanchnic ischemia-reperfusion (I/R) have been implicated as the initial triggering events that contribute to the development of the systemic inflammatory response, ALI, and MODS. Since hypoxia-inducible factor (HIF-1) is a key regulator of the physiological and pathophysiological response to hypoxia, we asked whether HIF-1 plays a proximal role in the induction of gut injury and subsequent lung injury. Utilizing partially HIF-1α-deficient mice in a global trauma hemorrhagic shock (T/HS) model, we found that HIF-1 activation was necessary for the development of gut injury and that the prevention of gut injury was associated with an abrogation of lung injury. Specifically, in vivo studies demonstrated that partial HIF-1α deficiency ameliorated T/HS-induced increases in intestinal permeability, bacterial translocation, and caspase-3 activation. Lastly, partial HIF-1α deficiency reduced TNF-α, IL-1β, cyclooxygenase-2, and inducible nitric oxide synthase levels in the ileal mucosa after T/HS whereas IL-1β mRNA levels were reduced in the lung after T/HS. This study indicates that prolonged intestinal HIF-1 activation is a proximal regulator of I/R-induced gut mucosal injury and gut-induced lung injury. Consequently, these results provide unique information on the initiating events in trauma-hemorrhagic shock-induced ALI and MODS as well as potential therapeutic insights.
Feinman
Rena
R
UMDNJ-New Jersey Medical School, Dept. of Surgery, Newark, 07103, USA. feinmarr@umdnj.edu
Deitch
Edwin A
EA
Watkins
Anthony C
AC
Abungu
Billy
B
Colorado
Iriana
I
Kannan
Kolenkode B
KB
Sheth
Sharvil U
SU
Caputo
Francis J
FJ
Lu
Qi
Q
Ramanathan
Madhuri
M
Attan
Shirhan
S
Badami
Chirag D
CD
Doucet
Danielle
D
Barlos
Dimitrios
D
Bosch-Marce
Marta
M
Semenza
Gregg L
GL
Xu
Da-Zhong
DZ
D000818:Animals; D017209:Apoptosis; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D005838:Genotype; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics* / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism*; D007410:Intestinal Diseases / Q000378:metabolism* / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007422:Intestines / Q000293:injuries* / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000473:pathology; D055370:Lung Injury / Q000378:metabolism / Q000473:pathology; D051379:Mice; D010539:Permeability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D012771:Shock, Hemorrhagic / Q000378:metabolism / Q000473:pathology
D016207:Cytokines; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger