% increase Estrogen Progesterone Est/IL-1� Est/Prog/IL-1�

MMP3 12 25 191 203CCL20 �9 65 52 53

Conclusion: MMP-3 and MT1-MMP are both collagenases andknown activators of MMP-9 and MMP-2 respectively. Est/Prog stim-ulated increases in MMP-3 expression may be a possible mechanismfor increased activation of MMP-9. Unlike MMP-2, MMP-9 is notproduced constitutively in vascular tissue. However, MMP-9 activityhas been found to increase following vascular injury and has beencorrelated to neointimal VSMC migration. Macrophages are majorsource of MMP-9, and CCL20 is a strong macrophage chemoattrac-tant. Prog may exacerbate the inflammatory response through up-regulation of CCL20, possibly by increasing macrophage infiltrationand the availability of MMP-9 protein. Collectively these hormonallyregulated genes may be contributing factors to increased VSMCmigration and accelerated intimal hyperplasia in women undergoinghormone replacement therapy at the time of vascular interventions.

QS155. ESTROGEN PREVENTS THE TESTOSTERONE-INDUCED DEPRESSION OF MESENCHYMAL STEMCELL VEGF PRODUCTION. Rinki Ray, Christine Her-ring, Troy Markel, Paul Crisostomo, Meijing Wang, YueWang, Keith D. Lillemoe, Daniel R. Meldrum; Indiana Uni-versity, Indianapolis, IN

Introduction: Modulating the paracrine effects of stem cells toobtain maximum growth factor production may help in formulatingthe best use of these cells in the treatment of ischemic tissue. En-dogenous estrogen has previously been shown to enhance VEGFproduction by mesenchymal stem cells (MSCs). However, little infor-mation exists regarding the effect of testosterone (T) on stem cellfunction. We therefore hypothesized that the addition of testosteroneto MSCs would decrease VEGF production in ovariectomized fe-males, but not normal females. Method: Bone marrow mesenchymalstem cells were collected from femurs and tibias of normal andovariectomized adult female rats. Cells were incubated at 37C in5%CO2, and exposed to 1) no hormone (NH), or 2) increasing doses oftestosterone (T�1nM, 10nM, and 100nM) for 48 hrs. 100,000 cellswere then isolated and incubated in normal media for an additional24 hours. Cells supernatants were collected, and VEGF productionwas measured by ELISA. P�0.05 was considered to be statisticallysignificant. Results: Exogenous testosterone significantly reducedVEGF production in non-stressed cells from ovariectomized femalesin a dose-dependent manner (NH: 875.3 �/�148.6 pg/ml; 1nM 775�/� 52.29 pg/ml; 10nm 623.8 �/� 68.11 pg/ml; 100nM 404.6 �/�50.06 pg/ml). The addition of 100nM of testosterone to cell culturessignificantly depressed VEGF production compared to NH (p�0.05).Interestingly, testosterone induced VEGF depression was ablated instem cells harvested from normal females (NH: 593.3 �/� 70.00pg/ml; 1 nM 600.8 �/� 58.33 pg/ml; 10nM 606.8 �/� 49.1 pg/ml,100nM 592.7 �/� 68.35 pg/ml). Conclusion: Estrogen prevents thedose dependent depression of MSC VEGF production that is inducedby exogenous testosterone. Understanding sex differences in stemcell function has obviously clinical implications regarding the iden-tification of the best source and ultimate pretreatment conditions.Furthermore, manipulating the mechanisms that stem cells use toproduce growth factors may allow us to engineer a stem cell thatproduces maximum amounts of protective growth factors duringtherapeutic use.

QS156. SOY ISOFLAVONE EQUOL BLOCKS RITONAVIR-INDUCED VASCULAR DYSFUNCTION IN PORCINEPULMONARY ARTERIES. Charlie Cheng, XinwenWang, Peter Lin, Qizhi Yao, Changyi J. Chen; Baylor Col-lege of Medicine, Houston, TX

Objective: Long term HIV infection and highly active antiretroviraltherapy (HAART) may be associated with many clinical complica-tions including pulmonary artery hypertension. Recently, we havefound that HIV protease inhibitor ritonavir (RTV) can induce vascu-lar dysfunction through oxidative stress. Soy isoflavones have potentantioxidative effects in many systems. The purpose of this study wasto determine whether equol, a new soy isoflavone, could preventRTV-induced vascular injury in porcine pulmonary arteries. Meth-ods: Porcine lungs were harvested and pulmonary artery rings wereincubated in 15 �M of RTV with or without equol in concentrationsof 0.1, 1, and 10 �M for 24 hours. Vasomotor function was measuredby a myograph tension system. Endothelial nitric oxide synthase(eNOS) mRNA and protein levels were determined using real-timePCR, western blot, and immunohistochemistry. Superoxide anionlevels were assayed by using lucigenin enhanced chemiluminescenceand dihydroethidium (DHE) staining. Results: RTV significantlyreduced the vessel contraction in response to thromboxane A2 analogU-46619, the endothelium-dependent vasorelaxation in response tobradykinin, and endothelium-independent vasorelaxation in re-sponse to sodium nitroprusside (SNP) in porcine pulmonary arteryrings. This vascular dysfunction was effectively blocked by co-treatment of equol in a concentration dependent manner. As molec-ular mechanisms, RTV reduced eNOS expression at both mRNA andprotein levels, while increased superoxide anion production in pul-monary artery rings and human pulmonary artery endothelial cells(HPAEC). Equol effectively blocked these RTV-induced molecularchanges. Conclusions: HIV protease inhibitor RTV causes signifi-cant vascular dysfunction of porcine pulmonary arteries throughdownregulation of eNOS expression and increase of superoxide anionproduction. Equol effectively blocks RTV-induced vascular dysfunc-tion and molecular regulations in this porcine pulmonary arterymodel. Thus, soy isoflavone equol may have clinical applications inHIV patients to prevent vascular and pulmonary complications ofantiretroviral drugs.

QS157. MECHANISMS OTHER THAN ACUTE HYPERGLY-CEMIA MEDIATE ENDOTHELIAL CELL ACTIVA-TION IN SYSTEMIC INFLAMMATORY RESPONSES.Peter B. Brant-Zawadzki, Andrew S. Weyrich, Guy A. Zim-merman, Larry W. Kraiss; University of Utah, Salt LakeCity, UT

Introduction: Recent clinical studies have shown a reduction insurgical ICU patient morbidity and mortality when intensive bloodglucose control (80-110 mg/dl) is achieved. The pathophysiology re-sponsible for the deleterious effects of hyperglycemia in these pa-tients is poorly understood, but it appears to be linked to the devel-opment of sepsis and an uncontrolled systemic inflammatory state.We hypothesized that acute hyperglycemia induces endothelial cellactivation by upregulating leukocyte adhesion and correspondinggenes known to mediate cell adhesion and inflammatory signaling.Methods: Human umbilical vein endothelial cells (HUVECs or ECs)were cultured to confluence in standard EC growth media and thensubjected to 24 hours of hyperglycemia (20mM or approximately 270mg/dl) versus hyper-osmolar control (mannitol, 20mM). Additionally,tumor necrosis factor-alpha (TNF-�) served as an inflammatorystimulus and was administered to cultures in escalating concentra-tions to determine if hyperglycemia primed EC activation. Afterpre-incubation under hyperglycemic or control conditions, ECs wereincubated with indium-111 labeled polymorphonuclear leukoyctes(PMNs) for five minutes and assayed to quantitatively determineleukocyte adhesion. In addition, real-time PCR was performed usingprimers for IL-6, IL-8, E-Selectin, ICAM and VCAM to quantifymRNA levels in the ECs under both hyperglycemic and controlconditions. Results: Hyperglycemia alone failed to increase adhe-siveness of ECs for PMNs when compared to mannitol or standardEC growth media (an iso-osmolar control with stock 5.5 mM glucoseconcentration). Hyperglycemia also failed to incur a measurable

329ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS