Hepatology Commons^™

Fibroblast Growth Factor 19 Secretion And Function In Perinatal Development, Caitlin Vonderohe, Gregory Guthrie, Douglas G Burrin

Faculty, Staff and Students Publications

Limited work has focused on fibroblast growth factor-19 (FGF19) secretion and function in the perinatal period. FGF19 is a potent growth factor that coordinates development of the brain, eye, inner ear, and skeletal system in the embryo, but after birth, FGF19 transitions to be an endocrine regulator of the classic pathway of hepatic bile acid synthesis. FGF19 has emerged as a mediator of metabolism and bile acid synthesis in aged animals and adults in the context of liver disease and metabolic dysfunction. FGF19 has also been shown to have systemic insulin-sensitizing and skeletal muscle hypertrophic effects when induced or supplemented …

Hepatocytes Demarcated By Ephb2 Contribute To The Progression Of Nonalcoholic Steatohepatitis, Yang Xiao, Kirill Batmanov, Wenxiang Hu, Kun Zhu, Alexander Y Tom, Dongyin Guan, Chunjie Jiang, Lan Cheng, Sam J Mccright, Eric C Yang, Matthew R Lanza, Yifan Liu, David A Hill, Mitchell A Lazar

Faculty, Staff and Students Publications

Current therapeutic strategies for treating nonalcoholic steatohepatitis (NASH) have failed to alleviate liver fibrosis, which is a devastating feature leading to hepatic dysfunction. Here, we integrated single-nucleus transcriptomics and epigenomics to characterize all major liver cell types during NASH development in mice and humans. The bifurcation of hepatocyte trajectory with NASH progression was conserved between mice and humans. At the nonalcoholic fatty liver (NAFL) stage, hepatocytes exhibited metabolic adaptation, whereas at the NASH stage, a subset of hepatocytes was enriched for the signatures of cell adhesion and migration, which were mainly demarcated by receptor tyrosine kinase ephrin type B receptor …

Eosinophils Protect Against Acetaminophen-Induced Liver Injury Through Cyclooxygenase-Mediated Il-4/Il-13 Production, Long Xu, Yang Yang, Jiali Jiang, Yankai Wen, Jong-Min Jeong, Christoph Emontzpohl, Constance L Atkins, Kangho Kim, Elizabeth A Jacobsen, Hua Wang, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND AND AIMS: A better understanding of the underlying mechanism of acetaminophen (APAP)-induced liver injury (AILI) remains an important endeavor to develop therapeutic approaches. Eosinophils have been detected in liver biopsies of patients with APAP overdose. We recently demonstrated a profound protective role of eosinophils against AILI; however, the molecular mechanism had not been elucidated.

APPROACH AND RESULTS: In agreement with our previous data from experiments using genetic deletion of eosinophils, we found that depletion of eosinophils in wild-type (WT) mice by an anti-IL-15 antibody resulted in exacerbated AILI. Moreover, adoptive transfer of eosinophils significantly reduced liver injury and mortality …

Regulation Of Skeletal Muscle Protein Synthesis In The Preterm Pig By Intermittent Leucine Pulses During Continuous Parenteral Feeding, Marko Rudar, Agus Suryawan, Hanh V Nguyen, Shaji K Chacko, Caitlin Vonderohe, Barbara Stoll, Douglas G Burrin, Marta L Fiorotto, Teresa A Davis

Faculty, Staff and Students Publications

BACKGROUND: Extrauterine growth restriction is a common complication of preterm birth. Leucine (Leu) is an agonist for the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) signaling pathway that regulates translation initiation and protein synthesis in skeletal muscle. Previously, we showed that intermittent intravenous pulses of Leu to neonatal pigs born at term receiving continuous enteral nutrition increases muscle protein synthesis and lean mass accretion. Our objective was to determine the impact of intermittent intravenous pulses of Leu on muscle protein anabolism in preterm neonatal pigs administered continuous parenteral nutrition.

METHODS: Following preterm delivery (on day 105 of 115 gestation), …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Interplay Between Liver Type 1 Innate Lymphoid Cells And Nk Cells Drives The Development Of Alcoholic Steatohepatitis, Chen Cheng, Qian Zhang, Yue Li, Jiali Jiang, Linxi Xie, Haiyuan Shen, Dongqing Wu, Hejiao Zhang, Huiru Zhang, Xuan Wang, Hongyu Wu, Jingjing Xu, Li Gui, Bao Li, Cynthia Ju, Hui Peng, Shi Yin, Long Xu

Faculty, Staff and Student Publications

BACKGROUND & AIMS: Liver contains high frequency of group 1 innate lymphoid cells (ILC), which are composed of comparable number of type 1 ILC (ILC1) and natural killer (NK) cells in steady state. Little is known about whether and how the interaction between ILC1 and NK cells affects the development of alcoholic liver disease.

METHODS: A mouse model of chronic alcohol abuse plus single-binge (Gao-Binge model) was established. The levels of alanine aminotransferase/aspartate aminotransferase, hepatic lipid, and inflammatory cytokines or neutrophils were measured to evaluate the degree of liver injury, steatosis, and inflammation. Flow cytometric analysis, cell depletion, or adoptive …

In Vitro And In Vivo Phototoxicity On Gastric Mucosa Induced By Methylene Blue, Hui Yeong Oh, Hyun Ho Choi, Eui Jin Kim, Ji Hye Choi, Sung Sook Choi, Hae Kyung Lee, Hyung-Keun Kim, Sang Woo Kim, Won Sang H Park, Hiun Suk Chae

Faculty, Staff and Student Publications

BACKGROUND: Methylene blue (MB) is used endoscopically to demarcate tumors and as a photosensitizer in photodynamic therapy (PDT). However, there are few in vivo studies about its toxicity in healthy stomach tissue. We performed sequential in vitro and in vivo analyses of MB-induced phototoxicity.

METHODS: We performed in vitro experiments using the AGS human gastric cancer cell line treated with light-emitting diode (LED) irradiation (3.6 J/cm

RESULTS: In vitro, increased concentrations of MB led to higher TUNEL scores. However, cell viability was significantly lower after MB plus LED irradiation than after treatment with MB alone (P < 0.001). In vivo, the TUNEL score was highest immediately after treatment with 0.1% or 0.5% MB plus light irradiation, and the score was significantly higher in the LED illumination plus MB group than in the control group (P < 0.05). The elevated TUNEL score was maintained for 3 days in the MB plus light irradiation group but returned to normal levels on day 10.

CONCLUSIONS: : Endoscopic light …

Infant Behavioral State And Stool Microbiome In Infants Receiving Lactocaseibacillus Rhamnosus Gg In Formula: Randomized Controlled Trial, Robert J Shulman, Maciej Chichlowski, Fabiola Gutierrez Orozco, Cheryl L Harris, Jennifer L Wampler, Nicholas A Bokulich, Carol Lynn Berseth

Faculty, Staff and Students Publications

BACKGROUND: Our aim was to evaluate infant behavioral state, stool microbiome profile and calprotectin in infants with infantile colic receiving a partially hydrolyzed protein formula with or without added Lacticaseibacillus (formerly Lactobacillus) rhamnosus GG (LGG).

METHODS: In this single-center, double-blind, controlled, parallel, prospective study, term infants (14-28 days of age) identified with colic (using modified Wessel's criteria: cried and/or fussed ≥ 3 h/day for ≥ 3 days/week, in a one-week period) were randomized to receive one of two formulas over a three-week feeding period: marketed partially hydrolyzed cow's milk-based infant formula (PHF, n = 35) or a similar formula with …

Hepatic Circadian And Differentiation Factors Control Liver Susceptibility For Fatty Liver Disease And Tumorigenesis, Baharan Fekry, Aleix Ribas-Latre, Rachel Van Drunen, Rafael Bravo Santos, Samay Shivshankar, Yulin Dai, Zhongming Zhao, Seung-Hee Yoo, Zheng Chen, Kai Sun, Frances M Sladek, Mamoun Younes, Kristin Eckel-Mahan

Faculty, Staff and Student Publications

Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths, and the most common primary liver malignancy to present in the clinic. With the exception of liver transplant, treatment options for advanced HCC are limited, but improved tumor stratification could open the door to new treatment options. Previously, we demonstrated that the circadian regulator Aryl Hydrocarbon-Like Receptor Like 1 (ARNTL, or Bmal1) and the liver-enriched nuclear factor 4 alpha (HNF4α) are robustly co-expressed in healthy liver but incompatible in the context of HCC. Faulty circadian expression of HNF4α- either by isoform switching, or loss of expression- results in an increased …

Dietary Fat Composition Shapes Bile Acid Metabolism And Severity Of Liver Injury In A Pig Model Of Pediatric Nafld, Rodrigo Manjarín, Kayla Dillard, Morgan Coffin, Gabriella V Hernandez, Victoria A Smith, Trista Noland-Lidell, Tanvi R Gehani, Hayden J Smart, Kevin Wheeler, Kimberly A Sprayberry, Mark S Edwards, Rob K Fanter, Hunter Glanz, Chad Immoos, Tasha M Santiago-Rodriguez, Jason M Blank, Douglas G Burrin, Brian D Piccolo, Mohammed Abo-Ismail, Michael R La Frano, Magdalena Maj

Faculty, Staff and Students Publications

The objective of this study was to investigate the effect of dietary fatty acid (FA) composition on bile acid (BA) metabolism in a pig model of NAFLD, by using a multiomics approach combined with histology and serum biochemistry. Thirty 20-day-old Iberian pigs pair-housed in pens were randomly assigned to receive 1 of 3 hypercaloric diets for 10 wk: 1) lard-enriched (LAR; n = 5 pens), 2) olive oil-enriched (OLI; n = 5), and 3) coconut oil-enriched (COC; n = 5). Animals were euthanized on week 10 after blood sampling, and liver, colon, and distal ileum (DI) were …

Hepatic Recruitment Of Eosinophils And Their Protective Function During Acute Liver Injury, Long Xu, Yang Yang, Yankai Wen, Jong-Min Jeong, Christoph Emontzpohl, Constance L Atkins, Zhaoli Sun, Kyle L Poulsen, David R Hall, J Steve Bynon, Bin Gao, William M Lee, Jody Rule, Elizabeth A Jacobsen, Hua Wang, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND & AIMS: Beyond the classical description of eosinophil functions in parasite infections and allergic diseases, emerging evidence supports a critical role of eosinophils in resolving inflammation and promoting tissue remodeling. However, the role of eosinophils in liver injury and the underlying mechanism of their recruitment into the liver remain unclear.

METHODS: Hepatic eosinophils were detected and quantified using flow cytometry and immunohistochemical staining. Eosinophil-deficient (ΔdblGata1) mice were used to investigate the role of eosinophils in 3 models of acute liver injury. In vivo experiments using Il33

RESULTS: Hepatic accumulation of eosinophils was observed in patients with acetaminophen (APAP)-induced liver …

Mir-103-3p Promotes Hepatic Steatosis To Aggravate Nonalcoholic Fatty Liver Disease By Targeting Of Acox1, Jiexia Ding, Caixia Xia, Panpan Cen, Siying Li, Lifei Yu, Jing Zhu, Jie Jin

Faculty, Staff and Student Publications

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a major risk factor for hepatocellular carcinoma, and alterations in miRNA expression are related to the development of NAFLD. However, the role of miRNAs in regulating the development of NAFLD is still poorly understood.

METHODS: We used qRT-PCR to detect the level of miR-103-3p in both cell and mouse models of NAFLD. Biochemical assays, DCF-DA assays, Oil red O staining and HE staining were used to detect the role of miR-103-3p in NAFLD development. Target genes of miR-103-3p were predicted using the TargetScan database and verified by qRT-PCR, western blot and dual-luciferase assays. …

A Phospholipid Mimetic Targeting Lrh-1 Ameliorates Colitis, Suzanne G Mays, Emma H D'Agostino, Autumn R Flynn, Xiangsheng Huang, Guohui Wang, Xu Liu, Elizabeth J Millings, C Denise Okafor, Anamika Patel, Michael L Cato, Jeffery L Cornelison, Diana Melchers, René Houtman, David D Moore, John W Calvert, Nathan T Jui, Eric A Ortlund

Faculty, Staff and Students Publications

Phospholipids are ligands for nuclear hormone receptors (NRs) that regulate transcriptional programs relevant to normal physiology and disease. Here, we demonstrate that mimicking phospholipid-NR interactions is a robust strategy to improve agonists of liver receptor homolog-1 (LRH-1), a therapeutic target for colitis. Conventional LRH-1 modulators only partially occupy the binding pocket, leaving vacant a region important for phospholipid binding and allostery. Therefore, we constructed a set of molecules with elements of natural phospholipids appended to a synthetic LRH-1 agonist. We show that the phospholipid-mimicking groups interact with the targeted residues in crystal structures and improve binding affinity, LRH-1 transcriptional activity, …

Opposing Roles Of Hdac6 In Liver Regeneration And Hepatocarcinogenesis, Sophors Phorl, Azra Memon, Yuri Seo, Thi Oanh Hoang, Trung Nghia Tran, Le Minh Tri Nguyen, Chang Hoon Lee, Woon Kyu Lee, Joo-Yong Lee

Faculty, Staff and Student Publications

Histone deacetylase 6 (HDAC6), a deacetylase of p53, has emerged as a privileged inhibitory target for cancer therapy because of its deacetylating activity for p53 at K120 and K373/382. However, intricate roles of HDAC6 in hepatocellular carcinogenesis have been suggested by recent evidence, namely that HDAC6 ablation suppresses innate immunity, which plays critical roles in tumor immunosurveillance and antitumor immune responses. Therefore, it is valuable to determine whether HDAC6 ablation inhibits hepatocellular carcinogenesis using in vivo animal models. Here, we firstly showed that HDAC6 ablation increased K320 acetylation of p53, known as pro-survival acetylation, in all tested animal models but …

Regulation Of Pgc1Α Downstream Of The Insulin Signaling Pathway Plays A Role In The Hepatic Proteotoxicity Of Mutant Α1-Antitrypsin Deficiency Variant Z, David A Rudnick, Jiansheng Huang, Tunda Hidvegi, Andrew S Chu, Pamela Hale, Admire Munanairi, Dennis J Dietzen, Paul F Cliften, Eric Tycksen, Andrew J Lutkewitte, Brian N Finck, Stephen C Pak, Gary A Silverman, David H Perlmutter

Faculty, Staff and Students Publications

BACKGROUND & AIMS: Insulin signaling is known to regulate essential proteostasis mechanisms.

METHODS: The analyses here examined effects of insulin signaling in the PiZ mouse model of α1-antitrypsin deficiency in which hepatocellular accumulation and proteotoxicity of the misfolded α1-antitrypsin Z variant (ATZ) causes liver fibrosis and cancer.

RESULTS: We first studied the effects of breeding PiZ mice to liver-insulin-receptor knockout (LIRKO) mice (with hepatocyte-specific insulin-receptor gene disruption). The results showed decreased hepatic ATZ accumulation and liver fibrosis in PiZ x LIRKO vs PiZ mice, with reversal of those effects when we bred PiZ x LIRKO mice onto a FOXO1-deficient background. …

Cholestasis Alters Brain Lipid And Bile Acid Composition And Compromises Motor Function In Neonatal Piglets, Nicole Lind Henriksen, Svend Høime Hansen, Matthew Domenic Lycas, Xiaoyu Pan, Thomas Eriksen, Lars Søndergaard Johansen, Richard R Sprenger, Christer Stenby Ejsing, Douglas G Burrin, Kerstin Skovgaard, Vibeke Brix Christensen, Thomas Thymann, Stanislava Pankratova

Faculty, Staff and Students Publications

Infants with neonatal cholestasis are prone to neurodevelopmental deficits, however, the underlying pathogenesis is unclear. Lipid malabsorption and accumulation of potentially neurotoxic molecules in the blood such as bile acids are important yet relatively unexplored pathways. Here, we developed a translational piglet model to understand how the molecular bile acid and lipid composition of the brain is affected by this disease and relates to motor function. Piglets (8-days old) had bile duct ligation or sham surgery and were fed a formula diet for 3 weeks. Alongside sensory-motor deficits observed in bile duct-ligated animals, we found a shift toward a more …

Maternal And Fetal Bile Acid Homeostasis Regulated By Sulfated Progesterone Metabolites Through Fxr Signaling Pathway In A Pregnant Sow Model, Peng Wang, Peiqiang Yuan, Sen Lin, Heju Zhong, Xiaoling Zhang, Yong Zhuo, Jian Li, Lianqiang Che, Bin Feng, Yan Lin, Shengyu Xu, De Wu, Douglas G Burrin, Zhengfeng Fang

Faculty, Staff and Students Publications

Abnormally elevated circulating bile acids (BA) during pregnancy endanger fetal survival and offspring health; however, the pathology and underlying mechanisms are poorly understood. A total of nineteen pregnant sows were randomly assigned to day 60 of gestation, day 90 of gestation (G60, G90), and the farrowing day (L0), to investigate the intercorrelation of reproductive hormone, including estradiol, progesterone and sulfated progesterone metabolites (PMSs), and BA in the peripheral blood of mother and fetuses during pregnancy. All data were analyzed by Student’s t-test or one-way ANOVA of GraphPad Prism and further compared by using the Student–Newman–Keuls test. Correlation analysis was …

Evaluation Of Heat Inactivation Of Human Norovirus In Freshwater Clams Using Human Intestinal Enteroids, Tsuyoshi Hayashi, Yoko Yamaoka, Atsushi Ito, Takashi Kamaishi, Ryuichi Sugiyama, Mary K Estes, Masamichi Muramatsu, Kosuke Murakami

Faculty, Staff and Students Publications

Foodborne disease attributed to the consumption of shellfish contaminated with human norovirus (HuNoV) is one of many global health concerns. Our study aimed to determine the conditions of the heat-inactivation of HuNoV in freshwater clams (Corbicula japonica) using a recently developed HuNoV cultivation system employing stem-cell derived human intestinal enteroids (HIEs). We first measured the internal temperature of the clam tissue in a water bath during boiling at 90 °C and found that approximately 2 min are required for the tissue to reach 90 °C. Next, GII.4 HuNoV was spiked into the center of the clam tissue, followed …

Tissue-Specific Mechanisms Of Bile Acid Homeostasis And Activation Of Fxr-Fgf19 Signaling In Preterm And Term Neonatal Pigs, Caitlin Vonderohe, Greg Guthrie, Barbara Stoll, Shaji Chacko, Harry Dawson, Douglas G Burrin

Children’s Nutrition Research Center Staff Publications

The tissue-specific molecular mechanisms involved in perinatal liver and intestinal farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling are poorly defined. Our aim was to establish how gestational age and feeding status affect bile acid synthesis pathway, bile acid pool size, ileal response to bile acid stimulation, genes involved in bile acid-FXR-FGF19 signaling and plasma FGF19 in neonatal pigs. Term (n = 23) and preterm (n = 33) pigs were born via cesarean section at 100% and 90% gestation, respectively. Plasma FGF19, hepatic bile acid and oxysterol profiles, and FXR target gene expression were assessed in pigs …

Loss Of H2r Signaling Disrupts Neutrophil Homeostasis And Promotes Inflammation-Associated Colonic Tumorigenesis In Mice, Zhongcheng Shi, Yuko Mori-Akiyama, Wa Du, Robert Fultz, Yanling Zhao, Wenly Ruan, Susan Venable, Melinda A Engevik, James Versalovic

Faculty, Staff and Students Publications

BACKGROUND & AIMS: We previously showed that histamine suppressed inflammation-associated colonic tumorigenesis through histamine type 2 receptor (H2R) signaling in mice. This study aimed to precisely elucidate the downstream effects of H2R activation in innate immune cells.

METHODS: Analyses using online databases of single-cell RNA sequencing of intestinal epithelial cells in mice and RNA sequencing of mouse immune cells were performed to determine the relative abundances of 4 histamine receptors among different cell types. Mouse neutrophils, which expressed greater amounts of H2R, were collected from the peritoneum of wild-type and H2R-deficient mice, of which low-density and high-density neutrophils were extracted …

The Autophagic Protein P62 Is A Target Of Reactive Aldehydes In Human And Murine Cholestatic Liver Disease, Colin T Shearn, Aimee L Anderson, Michael W Devereux, David J Orlicky, Cole Michel, Dennis R Petersen, Colin G Miller, Sanjiv Harpavat, Edward E Schmidt, Ronald J Sokol

Faculty, Staff and Students Publications

Inflammatory cholestatic liver diseases, including Primary Sclerosing Cholangitis (PSC), are characterized by periportal inflammation with progression to cirrhosis. The objective of this study was to examine interactions between oxidative stress and autophagy in cholestasis. Using hepatic tissue from male acute cholestatic (bile duct ligated) as well as chronic cholestatic (Mdr2KO) mice, localization of oxidative stress, the antioxidant response and induction of autophagy were analyzed and compared to human PSC liver. Concurrently, the ability of reactive aldehydes to post-translationally modify the autophagosome marker p62 was assessed in PSC liver tissue and in cell culture. Expression of autophagy markers was upregulated in …

Pathologic Inflammation In Malnutrition Is Driven By Proinflammatory Intestinal Microbiota, Large Intestine Barrier Dysfunction, And Translocation Of Bacterial Lipopolysaccharide, Grace T Patterson, Elvia Y Osorio, Alex Peniche, Sara M Dann, Erika Cordova, Geoffrey A Preidis, Ji Ho Suh, Ichiaki Ito, Omar A Saldarriaga, Michael Loeffelholz, Nadim J Ajami, Bruno L Travi, Peter C Melby

Faculty, Staff and Students Publications

Acute malnutrition, or wasting, is implicated in over half of all deaths in children under five and increases risk of infectious disease. Studies in humans and preclinical models have demonstrated that malnutrition is linked to an immature intestinal microbiota characterized by increased prevalence of Enterobacteriaceae. Observational studies in children with moderate acute malnutrition (MAM) have also observed heightened systemic inflammation and increased circulating bacterial lipopolysaccharides (LPS; endotoxin). However, the mechanisms that underpin the systemic inflammatory state and endotoxemia, and their pathophysiological consequences, remain uncertain. Understanding these pathophysiological mechanisms is necessary to design targeted treatments that will improve the unacceptable rate …

Crosstalk Between Beta-Adrenergic And Insulin Signaling Mediates Mechanistic Target Of Rapamycin Hyperactivation In Liver Of High-Fat Diet-Fed Male Mice, Sadia Ashraf, Nadia Ashraf, Gizem Yilmaz, Romain Harmancey

Faculty, Staff and Student Publications

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. While increased nutrient intake and sympathetic activity have been associated with the disease, the pathogenesis of NAFLD remains incompletely understood. We investigated the impact of the interaction of high dietary fat and sugar intake with increased beta-adrenergic receptor (β-AR) signaling on the activity of nutrient-sensing pathways and fuel storage in the liver. C57BL/6J mice were fed a standard rodent diet (STD), a high-fat diet (HFD), a high-fat/high-sugar Western diet (WD), a high-sugar diet with mixed carbohydrates (HCD), or a high-sucrose diet (HSD). After 6 week on …

Crosstalk Between Beta-Adrenergic And Insulin Signaling Mediates Mechanistic Target Of Rapamycin Hyperactivation In Liver Of High-Fat Diet-Fed Male Mice, Sadia Ashraf, Nadia Ashraf, Gizem Yilmaz, Romain Harmancey

Faculty, Staff and Student Publications

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. While increased nutrient intake and sympathetic activity have been associated with the disease, the pathogenesis of NAFLD remains incompletely understood. We investigated the impact of the interaction of high dietary fat and sugar intake with increased beta-adrenergic receptor (β-AR) signaling on the activity of nutrient-sensing pathways and fuel storage in the liver. C57BL/6J mice were fed a standard rodent diet (STD), a high-fat diet (HFD), a high-fat/high-sugar Western diet (WD), a high-sugar diet with mixed carbohydrates (HCD), or a high-sucrose diet (HSD). After 6 week on …

Sirt3 Is Required For Liver Regeneration But Not For The Beneficial Effect Of Nicotinamide Riboside, Sarmistha Mukherjee, James Mo, Lauren M Paolella, Caroline E Perry, Jade Toth, Mindy M Hugo, Qingwei Chu, Qiang Tong, Karthikeyani Chellappa, Joseph A Baur

Children’s Nutrition Research Center Staff Publications

Liver regeneration is critical to survival after traumatic injuries, exposure to hepatotoxins, or surgical interventions, yet the underlying signaling and metabolic pathways remain unclear. In this study, we show that hepatocyte-specific loss of the mitochondrial deacetylase SIRT3 drastically impairs regeneration and worsens mitochondrial function after partial hepatectomy. Sirtuins, including SIRT3, require NAD as a cosubstrate. We previously showed that the NAD precursor nicotinamide riboside (NR) promotes liver regeneration, but whether this involves sirtuins has not been tested. Here, we show that despite their NAD dependence and critical roles in regeneration, neither SIRT3 nor its nuclear counterpart SIRT1 is required for …

Hypoxia-Inducible Factor–1Α–Dependent Induction Of Mir122 Enhances Hepatic Ischemia Tolerance, Cynthia Ju, Meng Wang, Eunyoung Tak, Boyun Kim, Christoph Emontzpohl, Yang Yang, Xiaoyi Yuan, Huban Kutay, Yafen Liang, David R Hall, Wasim A Dar, J Steve Bynon, Peter Carmeliet, Kalpana Ghoshal, Holger K Eltzschig

Faculty, Staff and Student Publications

Hepatic ischemia and reperfusion (IR) injury contributes to the morbidity and mortality associated with liver transplantation. microRNAs (miRNAs) constitute a family of noncoding RNAs that regulate gene expression at the posttranslational level through the repression of specific target genes. Here, we hypothesized that miRNAs could be targeted to enhance hepatic ischemia tolerance. A miRNA screen in a murine model of hepatic IR injury pointed us toward the liver-specific miRNA miR122. Subsequent studies in mice with hepatocyte-specific deletion of miR122 (miR122loxP/loxP Alb-Cre+ mice) during hepatic ischemia and reperfusion revealed exacerbated liver injury. Transcriptional studies implicated hypoxia-inducible factor-1α (HIF1α) in the induction …

Vertical Sleeve Gastrectomy Confers Metabolic Improvements By Reducing Intestinal Bile Acids And Lipid Absorption In Mice, Lili Ding, Eryun Zhang, Qiaoling Yang, Lihua Jin, Kyle M Sousa, Bingning Dong, Yangmeng Wang, Jui Tu, Xiaoxiao Ma, Jingyan Tian, Hongli Zhang, Zhipeng Fang, Ana Guan, Yixin Zhang, Zhengtao Wang, David D Moore, Li Yang, Wendong Huang

Faculty, Staff and Students Publications

Vertical sleeve gastrectomy (VSG) is a highly effective bariatric surgery that sustainably treats obesity and type 2 diabetes (T2D). However, the underlying mechanisms governing its metabolic benefits remain unclear. In this study, we have used four different genetically modified mouse lines to understand the link between bile acid circulation and metabolic effects of VSG. Instead of directly activating the nuclear bile acid receptor farnesoid X receptor (Fxr) in the liver or intestine, VSG reduces intestinal levels of bile acids, thereby decreasing fat absorption in the intestine. Given the rising popularity of bariatric surgeries to treat obesity and associated T2D, the …

Parenteral Lipids Shape Gut Bile Acid Pools And Microbiota Profiles In The Prevention Of Cholestasis In Preterm Pigs, Lee Call, Tiffany Molina, Barbara Stoll, Greg Guthrie, Shaji Chacko, Jogchum Plat, Jason Robinson, Sen Lin, Caitlin Vonderohe, Mahmoud Mohammad, Dennis Kunichoff, Stephanie Cruz, Patricio Lau, Muralidhar Premkumar, Jon Nielsen, Zhengfeng Fang, Oluyinka Olutoye, Thomas Thymann, Robert Britton, Per Sangild, Douglas Burrin

Children’s Nutrition Research Center Staff Publications

Multi-component lipid emulsions, rather than soy-oil emulsions, prevent cholestasis by an unknown mechanism. Here, we quantified liver function, bile acid pools, and gut microbial and metabolite profiles in premature parenterally fed pigs given a soy-oil lipid emulsion, Intralipid (IL), a multi component lipid emulsion, SMOFlipid (SMOF), a novel emulsion with a modified fatty-acid composition [experimental emulsion (EXP)], or a control enteral diet (ENT) for 22 days. We assayed serum cholestasis markers, measured total bile acid levels in plasma, liver, and gut contents, and analyzed colonic bacterial 16S rRNA gene sequences and metabolomic profiles. Serum cholestasis markers (i.e., bilirubin, bile acids, …

Hypoxia-Inducible Factor (Hif)-2Α Reprograms Liver Macrophages To Protect Against Acute Liver Injury Via The Production Of Interleukin-6, Rachel Y Gao, Meng Wang, Qihui Liu, Dechun Feng, Yankai Wen, Yang Xia, Sean P Colgan, Holger K Eltzschig, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND AND AIMS: Acetaminophen (APAP) overdose represents the most frequent cause of acute liver failure, resulting in death or liver transplantation in more than one third of patients in the United States. The effectiveness of the only antidote, N-acetylcysteine, declines rapidly after APAP ingestion, long before patients are admitted to the clinic with symptoms of severe liver injury. The direct hepatotoxicity of APAP triggers a cascade of innate immune responses that may exacerbate or limit the progression of tissue damage. A better understanding of this complex mechanism will help uncover targets for therapeutic interventions.

APPROACH AND RESULTS: We observed that …

Methyl-Sensing Nuclear Receptor Liver Receptor Homolog-1 Regulates Mitochondrial Function In Mouse Hepatocytes, Sungwoo Choi, Bingning Dong, Chih-Chun Janet Lin, Mi Jeong Heo, Kang Ho Kim, Zhen Sun, Martin Wagner, Nagireddy Putluri, Jae Myoung Suh, Meng C Wang, David D Moore

Faculty, Staff and Students Publications

Liver receptor homologue-1 (LRH-1; NR5A2) is a nuclear receptor that regulates metabolic homeostasis in the liver. Previous studies identified phosphatidylcholines as potential endogenous agonist ligands for LRH-1. In the liver, distinct subsets of phosphatidylcholine species are generated by two different pathways: choline addition to phosphatidic acid via the Kennedy pathway, or trimethylation of phosphatidylethanolamine via Phosphatidylethanolamine N-methyl Transferase (PEMT). Here we report that a PEMT - LRH-1 pathway specifically couples methyl metabolism and mitochondrial activities in hepatocytes. We show that the loss of Lrh-1 reduces mitochondrial number, basal respiration, beta-oxidation and ATP production in hepatocytes, and decreases expression of mitochondrial …