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Wnt Signaling Prevents Oxidative Hepatic Injury Through Enhanced Mitochondrial Function
ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS against acute alcohol-induced liver injury. Methods: C57BL/6 female mice were treated with a binge ethanol dose [6 g/kg body weight] by gastric gavage +/- pre-treatment, simultaneous treatment or post-treatment (n ¼ 5) with varying doses of IAP [100 U or 200 U/gavage]. Control mice were gavaged with dextran maltose. In a second set of experiments, mice were gavaged with a binge ethanol dose [5 g/kg body weight] every 12 hours for a total of 3 doses +/- pretreatment with IAP [200 U/gavage]. Mice were sacrificed at different times up until 4 hours following the last dose, and investigated for hematological, inflammatory and histopathological liver changes. Results: In the single dose study, pretreatment with IAP resulted in significantly lower serum alanine aminotransferase (ALT) than the ethanol (EtOH) group in a dose dependent fashion (there was an approximate 38 % inhibition with the high dose of IAP, 200 U). Simultaneous treatment(sim) with IAP (100 U/gavage) also lowered serum ALT (EtOH vs. EtOH+simIAP ¼ 110 6 6.6 vs. 89.8 6 5.7 U/L, p ¼0.04). In contrast, when IAP was gavaged (100 U) 60 min after EtOH gavage, there was no beneficial impact in regard to ALT levels. In the 3 dose study, pretreatment with IAP (200 U) significantly lowered serum LPS (EtOH vs. EtOH+IAP ¼ 2.1 6 0.35 vs. 1.0 6 0.21 EU/ml, p ¼0.027), serum ALT (EtOH vs. EtOH+IAP ¼ 114 6 16.1 vs. 68.9 6 6.7 U/L, p ¼0.034) and protected against hepatic steatosis (Fig; EtOH vs. EtOH+IAP ¼ 4 vs. 2, Hepatic Steatosis Score). Furthermore, hepatotoxicity due to acute ethanol administration was further evidenced by elevated liver TNF-alpha which was also attenuated by IAP (EtOH vs. EtOH+IAP ¼ 80.44 6 7.9 vs. 55.01 6 7.0 pg/mg protein, p ¼ 0.035). Conclusions: Treatment with Oral IAP protected mice from acute alcohol-induced hepatotoxicity and steatosis. Oral IAP supplementation could represent a novel therapy to prevent against alcoholic liver disease in humans.
24.4. Wnt Signaling Prevents Oxidative Hepatic Injury Through Enhanced Mitochondrial Function. B. Liu,1 R. Zhang,1 G. Tao,1 N. C. Lehwald,1 B. Liu,1 Y. Koh,1 K. G. Sylvester1; 1Department of Surgery, Division of Pediatric Surgery, Stanford University, School of Medicine, Stanford, CA; 2Department of General, Visceral and Pediatric Surgery, School of Medicine, Heinrich Heine University, Duesseldorf, Dsseldorf Introduction: The Wnt signaling pathway has established biologic roles in liver development, regeneration and carcinogenesis. Given the common need for cellular energy utilization in each of these processes, we hypothesized that Wnt/b-catenin signaling would directly regulate hepatocyte mitochondrial function. Methods: To investigate the role of Wnt pathway on mitochondrial function, mice were engineered to over express Wnt1 in hepatocytes under the control of a tetracycline analog (Lap-tta-tetOWnt1)(TWNT). TWNT and WT mice (n>5) underwent ischemia / reperfusion injury (IRI) to provide oxidative mitochondrial injury. AML12 hepatocytes were exposed to Wnt agonists (Wnt3a, LiCl) for in vitro experiments. Results: We observed increased mitochondrial DNA copy number and membrane potential stabilization as well as reduced reactive oxygen species (ROS) levels in TWNT mice compared to controls following IRI. Reduced levels of hepatocyte apoptosis involving the mitochondrial pathway (caspase 9, 3 and 7, released cytoC) were also observed in TWNT mice. In-
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creased tricarboxylic acid cycle (TCA) activity and ATP levels in TWNT mice demonstrate that mitochondrial activity is preserved by Wnt over-expression following IRI. AML12 cells treated by Wnt3a or the GSK3B inhibitor LiCl and exposed to hypoxia (2% for 36 hours) demonstrated decreased reactive oxygen species (ROS) by immunostainings for 8-hydroxyguanosine. Wnt3a and LiCl also reduced measures of mitochondrial damage (CytoC, SOD2) in cells following hypoxia compared to controls. Conclusions: Wnt/b-catenin signaling protects hepatocytes against oxidative injury and apoptosis through mitochondrial stabilization, enhanced TCA function, and reduced ROS generation. These findings significantly expand the understanding of Wnt signaling biology in hepatocytes and suggest the potential for the therapeutic application of Wnt pathway manipulation in a variety of clinical applications.
24.5. Comparative Quality of Life Effectiveness for Bariatric Surgery. N. Leva J. Morton; Stanford Hospital and Clinics Department of Surgery, Stanford, CA Introduction: Morbid obesity is the leading public health crisis in the US. Little is known about specific effects of different bariatric surgeries on quality of life. The purpose of this study was to analyze changes in quality of life of patients before and 12 months after bariatric surgery using the Short Form (36) Health Survey (SF-36). Methods: Preoperative and 12 month postoperative data were prospectively collected for 270 consecutive surgeries (174 Roux-en-Y-gastric bypass, 53 sleeve gastrectomy, and 43 adjustable gastric band) at a single academic institution. At each clinic visit, patients completed an SF-36 survey, divided into physical and mental health subtests. Patients were compared on the basis of age, gender, BMI, surgery type, insurance status and diabetes status. Demographic, preoperative, and postoperative data were compared with SF-36 scores by a one-way ANOVA for continuous variables and chi-squared analysis for dichotomous variables using GraphPad PrisimÒ software. Results: To date, 72.3% of 270 patients completed their 12-month questionnaire. Patient demographics between surgical groups and major preoperative comorbidities showed no significant differences and included an average BMI 44, age 47, 65% white, income $67,000, 81% with private insurance, and 4 total preoperative comorbidities. Men and women both demonstrated significant score improvements between their preoperative and 12-month time points (all p’s < 0.001). However, no statistically significant difference existed between men and women’s score improvements (all p’s > 0.11). Preoperatively, government insured patients scored lower than their privately insured counterparts regarding views of their physical (p < 0.001) and mental health (p ¼ 0.01). However, 12 months after bariatric surgery no difference existed between government and privately insured patient scores. Bypass and sleeve patients had more positive change in their view of physical health at 12 months postoperatively as compared with adjustable gastric band patients (p ¼<0.01). Bypass and sleeve patients also showed greater improvement in their view of mental health, although this finding was not statistically significant (p ¼ 0.13). No correlation existed between change in patient’s physical or mental health and age, number of preoperative comorbidities %EWL, or BMI. Conclusions: All bariatric surgeries resulted in an improved perception of both physical and mental health. Patients who underwent Roux-en-y-gastric bypass and sleeve gastrectomy surgeries showed greater improvements in physical health, with a trending improvement in mental health. As no correlation existed between changes in physical and mental health and %EWL or BMI, this effect appears independent of weight loss alone. Prior to surgery, government insured patients viewed their health more negatively than privately insured patients. Twelve months following surgery, this difference no longer existed.
24.4. Wnt Signaling Prevents Oxidative Hepatic Injury Through Enhanced Mitochondrial Function. B. Liu,1 R. Zhang,1 G. Tao,1 N. C. Lehwald,1 B. Liu,1 Y. Koh,1 K. G. Sylvester1; 1Department of Surgery, Division of Pediatric Surgery, Stanford University, School of Medicine, Stanford, CA; 2Department of General, Visceral and Pediatric Surgery, School of Medicine, Heinrich Heine University, Duesseldorf, Dsseldorf Introduction: The Wnt signaling pathway has established biologic roles in liver development, regeneration and carcinogenesis. Given the common need for cellular energy utilization in each of these processes, we hypothesized that Wnt/b-catenin signaling would directly regulate hepatocyte mitochondrial function. Methods: To investigate the role of Wnt pathway on mitochondrial function, mice were engineered to over express Wnt1 in hepatocytes under the control of a tetracycline analog (Lap-tta-tetOWnt1)(TWNT). TWNT and WT mice (n>5) underwent ischemia / reperfusion injury (IRI) to provide oxidative mitochondrial injury. AML12 hepatocytes were exposed to Wnt agonists (Wnt3a, LiCl) for in vitro experiments. Results: We observed increased mitochondrial DNA copy number and membrane potential stabilization as well as reduced reactive oxygen species (ROS) levels in TWNT mice compared to controls following IRI. Reduced levels of hepatocyte apoptosis involving the mitochondrial pathway (caspase 9, 3 and 7, released cytoC) were also observed in TWNT mice. In-
233
creased tricarboxylic acid cycle (TCA) activity and ATP levels in TWNT mice demonstrate that mitochondrial activity is preserved by Wnt over-expression following IRI. AML12 cells treated by Wnt3a or the GSK3B inhibitor LiCl and exposed to hypoxia (2% for 36 hours) demonstrated decreased reactive oxygen species (ROS) by immunostainings for 8-hydroxyguanosine. Wnt3a and LiCl also reduced measures of mitochondrial damage (CytoC, SOD2) in cells following hypoxia compared to controls. Conclusions: Wnt/b-catenin signaling protects hepatocytes against oxidative injury and apoptosis through mitochondrial stabilization, enhanced TCA function, and reduced ROS generation. These findings significantly expand the understanding of Wnt signaling biology in hepatocytes and suggest the potential for the therapeutic application of Wnt pathway manipulation in a variety of clinical applications.
24.5. Comparative Quality of Life Effectiveness for Bariatric Surgery. N. Leva J. Morton; Stanford Hospital and Clinics Department of Surgery, Stanford, CA Introduction: Morbid obesity is the leading public health crisis in the US. Little is known about specific effects of different bariatric surgeries on quality of life. The purpose of this study was to analyze changes in quality of life of patients before and 12 months after bariatric surgery using the Short Form (36) Health Survey (SF-36). Methods: Preoperative and 12 month postoperative data were prospectively collected for 270 consecutive surgeries (174 Roux-en-Y-gastric bypass, 53 sleeve gastrectomy, and 43 adjustable gastric band) at a single academic institution. At each clinic visit, patients completed an SF-36 survey, divided into physical and mental health subtests. Patients were compared on the basis of age, gender, BMI, surgery type, insurance status and diabetes status. Demographic, preoperative, and postoperative data were compared with SF-36 scores by a one-way ANOVA for continuous variables and chi-squared analysis for dichotomous variables using GraphPad PrisimÒ software. Results: To date, 72.3% of 270 patients completed their 12-month questionnaire. Patient demographics between surgical groups and major preoperative comorbidities showed no significant differences and included an average BMI 44, age 47, 65% white, income $67,000, 81% with private insurance, and 4 total preoperative comorbidities. Men and women both demonstrated significant score improvements between their preoperative and 12-month time points (all p’s < 0.001). However, no statistically significant difference existed between men and women’s score improvements (all p’s > 0.11). Preoperatively, government insured patients scored lower than their privately insured counterparts regarding views of their physical (p < 0.001) and mental health (p ¼ 0.01). However, 12 months after bariatric surgery no difference existed between government and privately insured patient scores. Bypass and sleeve patients had more positive change in their view of physical health at 12 months postoperatively as compared with adjustable gastric band patients (p ¼<0.01). Bypass and sleeve patients also showed greater improvement in their view of mental health, although this finding was not statistically significant (p ¼ 0.13). No correlation existed between change in patient’s physical or mental health and age, number of preoperative comorbidities %EWL, or BMI. Conclusions: All bariatric surgeries resulted in an improved perception of both physical and mental health. Patients who underwent Roux-en-y-gastric bypass and sleeve gastrectomy surgeries showed greater improvements in physical health, with a trending improvement in mental health. As no correlation existed between changes in physical and mental health and %EWL or BMI, this effect appears independent of weight loss alone. Prior to surgery, government insured patients viewed their health more negatively than privately insured patients. Twelve months following surgery, this difference no longer existed.