Histone deacetylase as therapeutic target in a rodent model of hemorrhagic shock: Effect of different resuscitation strategies on lung and liver Tom Lin, MD, MPH, a,b Huazhen Chen, MD, b Elena Koustova, PhD, b Elizabeth A. Sailhamer, MD, c Yongqing Li, MD, PhD, c Christian Shults, MD, a Baoling Liu, MD, c Peter Rhee, MD, MPH, b John Kirkpatrick, MD, a,b and Hasan B. Alam, MD, b,c Washington, DC, Bethesda, Md, and Boston, Mass Background. DNA transcription is regulated in part by acetylation of nuclear histones, controlled by 2 groups of enzymes: histone deacetylases (HDAC) and histone acetyl transferases (HAT). We have shown previously that hemorrhage and resuscitation are associated with HDAC/HAT imbalance, which influences the acetylation status of cardiac histones. The goals of this study were to determine whether: (1) resuscitation after hemorrhage affects histone acetylation in a fluid- and organ-specific fashion; and (2) administration of HDAC inhibitors influences histone acetylation and subsequent gene expression. Methods. In the first experiment, rats (n = 6/group) were subjected to volume-controlled hemorrhage and resuscitated with: (1) racemic lactated Ringer’s (DL-LR); (2) L-lactated Ringer’s (L-LR); (3) 7.5% hypertonic saline (HTS); (4) ketone Ringer’s (KR); or (5) pyruvate Ringer’s (PR). Control groups included: (6) no hemorrhage (Sham); and (7) hemorrhage with no resuscitation (NR). In the second experiment (n = 5/group), 3 HDAC inhibitors, valproic acid (VPA), trichostatin A (TSA), and suberoylanilide hydroxamic acid (SAHA), were added to normal saline and used as fluid for resuscitation. At the end of resuscitation, lung and liver tissues were subjected to subcellular protein fractionation and Western blotting to analyze histone acetylation. In addition, cDNA microarrays and RT-PCR were used to measure expression of selected genes. Results. Hemorrhage did not change the level of histone acetylation in lungs, whereas resuscitation predominantly hyperacetylated histones. An analysis of histone acetylation on 10 lysine sites showed that L-LR, HTS, and KR resuscitation caused the largest number of changes (7, 6, and 6 respectively). SAHA hyperacetylated 7 sites in liver and affected expression of 57 genes (44 up, 13 down). Conclusions. Resuscitation with various fluids, as well as infusion of pharmacologic HDAC inhibitors affects histone acetylation in a fluid- and organ-specific fashion, even when administered post-insult for a limited period of time. Uniquely affected genes are associated with metabolism, cellular growth, proliferation, differentiation, transformation, and cellular signaling. (Surgery 2007;141:784-94.) From the Department of Surgery, Washington Hospital Center, Washington, DC, a Uniformed Services University of the Health Sciences, Bethesda, MD, b and Massachusetts General Hospital/Harvard Medical School, Boston c Severe hemorrhage is a major cause of death after trauma and as many as 50% of trauma patients that survive the initial period of shock later develop multiple organ dysfunction, 1,2 such as acute lung injury, acute respiratory distress syndrome, and acute liver injury. Multiple organ failure (MOF) as a consequence of shock, develops in some, but not all patients. Researchers have focused on bio- logic, genomic, and genetic aspects to understand the disease heterogeneity and its complex patho- Presented at the 1st Annual Meeting of the Academic Surgical Congress, San Diego, CA (February 2006). Supported in part by the Office of Naval Research grants MDA 905-99-1-0022 (E.K.) and MDA905-03-1-004 (H.B.A.). Accepted for publication January 12, 2007. Reprint requests: Hasan B. Alam, MD, Division of Trauma, Emergency Surgery and Surgical Critical Care, Massachusetts General Hospital, 165 Cambridge St, Suite 810, Boston, MA 02114. E-mail: hbalam@partners.org. 0039-6060/$ - see front matter © 2007 Mosby, Inc. All rights reserved. doi:10.1016/j.surg.2007.01.014 784 SURGERY