Maternal Obesogenic Diet Attenuates Microbiome-Dependent Offspring Weaning Reaction with Worsening of Steatotic Liver Disease

The mechanisms by which maternal obesity increases the susceptibility to steatotic liver disease in offspring are incompletely understood. Models using different maternal obesogenic diets (MODEs) display phenotypic variability, likely reflecting the influence of timing and diet composition. This study compared three maternal obesogenic diets using standardized exposure times to identify differences in offspring disease progression. This study found that the severity of hepatic inflammation and fibrosis in the offspring depends on the composition of the maternal obesogenic diet. Offspring cecal microbiome composition was shifted in all MODE groups relative to control. Decreased α-diversity in some MODE offspring with shifts in abundance of multiple genera were suggestive of delayed maturation of the microbiome. The weaning reaction typically characterized by a spike in intestinal expression of Tnfa and Ifng was attenuated in MODE offspring in an early microbiome-dependent manner using cross-fostering. Cross-fostering also switched the severity of disease progression in offspring dependent on the diet of the fostering dam. These results identify maternal diet composition and timing of exposure as modifiers in mediating transmissible changes in the microbiome. These changes in the early microbiome alter a critical window during weaning that drives susceptibility to progressive liver disease in the offspring.

Thermal Transport in Nanoelectronic Devices Cooled by On-Chip Magnetic Refrigeration

On-chip demagnetization refrigeration has recently emerged as a powerful tool for reaching microkelvin electron temperatures in nanoscale structures. The relative importance of cooling on-chip and off-chip components and the thermal subsystem dynamics are yet to be analyzed. We study a Coulomb blockade thermometer with on-chip copper refrigerant both experimentally and numerically, showing that dynamics in this device are captured by a first-principles model. Our work shows how to simulate thermal dynamics in devices down to microkelvin temperatures, and outlines a recipe for a low-investment platform for quantum technologies and fundamental nanoscience in this novel temperature range.

Trophic and spatial patterns of contaminants in fishes from the Republic of the Marshall Islands in the equatorial Pacific

The Republic of the Marshall Islands (RMI) has been affected by marine pollution from militarization and urbanization. To address concerns raised by the Marshall Islands Marine Resources Authority, this study examined concentrations of dissolved contaminants in reef and pelagic fishes in the RMI and assessed potential associated risks. Metals, organochlorine pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were examined in reef and pelagic fishes from six atolls: Kwajalein, Majuro, Jaluit, Utirik, Rongelap, and Wotje. Clear trophic patterns emerged for metals. Total arsenic was highest in higher trophic level reef fishes, particularly in the camouflage grouper (Epinephelus polyphekadion) (>100 μg g^-1 total As), but inorganic arsenic was negligible in higher trophic levels and showed an inverse trend with the highest percentages present in parrotfishes and herbivores. Copper and mercury were elevated in higher trophic level reef and pelagic fishes, respectively, and the maximum mercury concentrations (6.45 μg g^-1 in Gymnosarda unicolor) were among the highest reported in the Pacific. Conversely, cadmium and lead were highest in lower trophic levels, like surgeonfishes and parrotfishes. PCBs were more clearly linked to locations and were highest at two atolls with military history (Kwajalein and Jaluit) (>U.S. EPA Screening Value of 2.5 ppb). PAHs were ubiquitous across taxa (detected in 97% of samples), but the highest concentrations were in lower trophic levels. Organochlorine pesticides were detected at very low concentrations that do not likely pose a risk. We compare concentrations to established thresholds for human health and find that - for specific locations and species - contaminant concentrations may pose a risk to fish and other marine taxa, as well as human consumers. This study provides baseline information that aids the development of marine conservation and public health recommendations and addresses a data gap that persists for marine pollution throughout the Pacific Islands.

Maternal Exercise Protects Male Offspring From Maternal Diet-Programmed Nonalcoholic Fatty Liver Disease Progression

Maternal obesity programs the risk for development of nonalcoholic fatty liver disease (NAFLD) in offspring. Maternal exercise is a potential intervention to prevent developmentally programmed phenotypes. We hypothesized that maternal exercise would protect from progression of NAFLD in offspring previously exposed to a maternal obesogenic diet. Female mice were fed chow (CON) or high fat, fructose, cholesterol (HFFC) and bred with lean males. A subset had an exercise wheel introduced 4 weeks after starting the diet to allow for voluntary exercise. The offspring were weaned to the HFFC diet for 7 weeks to induce NAFLD. Serum, adipose, and liver tissue were collected for metabolic, histologic, and gene expression analyses. Cecal contents were collected for 16S sequencing. Global metabolomics was performed on liver. Female mice fed the HFFC diet had increased body weight prior to adding an exercise wheel. Female mice fed the HFFC diet had an increase in exercise distance relative to CON during the preconception period. Exercise distance was similar between groups during pregnancy and lactation. CON-active and HFFC-active offspring exhibited decreased inflammation compared with offspring from sedentary dams. Fibrosis increased in offspring from HFFC-sedentary dams compared with CON-sedentary. Offspring from exercised HFFC dams exhibited less fibrosis than offspring from sedentary HFFC dams. While maternal diet significantly affected the microbiome of offspring, the effect of maternal exercise was minimal. Metabolomics analysis revealed shifts in multiple metabolites including several involved in bile acid, 1-carbon, histidine, and acylcarnitine metabolism. This study provides preclinical evidence that maternal exercise is a potential approach to prevent developmentally programmed liver disease progression in offspring.

Maternal obesogenic diet enhances cholestatic liver disease in offspring

Human and animal model data show that maternal obesity promotes nonalcoholic fatty liver disease in offspring and alters bile acid (BA) homeostasis. Here we investigated whether offspring exposed to maternal obesogenic diets exhibited greater cholestatic injury. We fed female C57Bl6 mice conventional chow (CON) or high fat/high sucrose (HF/HS) diet and then bred them with lean males. Offspring were fed 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) for 2 weeks to induce cholestasis, and a subgroup was then fed CON for an additional 10 days. Additionally, to evaluate the role of the gut microbiome, we fed antibiotic-treated mice cecal contents from CON or HF/HS offspring, followed by DDC for 2 weeks. We found that HF/HS offspring fed DDC exhibited increased fine branching of the bile duct (ductular reaction) and fibrosis but did not differ in BA pool size or intrahepatic BA profile compared to offspring of mice fed CON. We also found that after 10 days recovery, HF/HS offspring exhibited sustained ductular reaction and periportal fibrosis, while lesions in CON offspring were resolved. In addition, cecal microbiome transplant from HF/HS offspring donors worsened ductular reaction, inflammation, and fibrosis in mice fed DDC. Finally, transfer of the microbiome from HF/HS offspring replicated the cholestatic liver injury phenotype. Taken together, we conclude that maternal HF/HS diet predisposes offspring to increased cholestatic injury after DDC feeding and delays recovery after returning to CON diets. These findings highlight the impact of maternal obesogenic diet on hepatobiliary injury and repair pathways during experimental cholestasis.

Maternal obesogenic diet regulates offspring bile acid homeostasis and hepatic lipid metabolism via the gut microbiome in mice

Mice exposed in gestation to maternal high-fat/high-sucrose (HF/HS) diet develop altered bile acid (BA) homeostasis. We hypothesized that these reflect an altered microbiome and asked if microbiota transplanted from HF/HS offspring change hepatic BA and lipid metabolism to determine the directionality of effect. Female mice were fed HF/HS or chow (CON) for 6 wk and bred with lean males. 16S sequencing was performed to compare taxa in offspring. Cecal microbiome transplantation (CMT) was performed from HF/HS or CON offspring into antibiotic-treated mice fed chow or high fructose. BA, lipid metabolic, and gene expression analyses were performed in recipient mice. Gut microbiomes from HF/HS offspring segregated from CON offspring, with increased Firmicutes to Bacteriodetes ratios and Verrucomicrobial abundance. After CMT was performed, HF/HS-recipient mice had larger BA pools, increased intrahepatic muricholic acid, and decreased deoxycholic acid species. HF/HS-recipient mice exhibited downregulated hepatic Mrp2, increased hepatic Oatp1b2, and decreased ileal Asbt mRNA expression. HF/HS-recipient mice exhibited decreased cecal butyrate and increased hepatic expression of Il6. HF/HS-recipient mice had larger livers and increased intrahepatic triglyceride versus CON-recipient mice after fructose feeding, with increased hepatic mRNA expression of lipogenic genes including Srebf1, Fabp1, Mogat1, and Mogat2. CMT from HF/HS offspring increased BA pool and shifted the composition of the intrahepatic BA pool. CMT from HF/HS donor offspring increased fructose-induced liver triglyceride accumulation. These findings support a causal role for vertical transfer of an altered microbiome in hepatic BA and lipid metabolism in HF/HS offspring.NEW & NOTEWORTHY We utilized a mouse model of maternal obesogenic diet exposure to evaluate the effect on offspring microbiome and bile acid homeostasis. We identified shifts in the offspring microbiome associated with changes in cecal bile acid levels. Transfer of the microbiome from maternal obesogenic diet-exposed offspring to microbiome-depleted mice altered bile acid homeostasis and increased fructose-induced hepatic steatosis.

A clinical model to predict fibrosis on liver biopsy in paediatric subjects with nonalcoholic fatty liver disease

The incidence of nonalcoholic fatty liver disease (NAFLD) in children is rapidly increasing. Liver fibrosis is a poor prognostic feature that independently predicts cirrhosis. The time that intercedes the first medical encounter and biopsy is rate-limiting to multi-modal treatment. This study aimed to identify non-invasive parameters to predict advanced NAFLD and fibrosis. We conducted a single-center, retrospective 10-year analysis of 640 paediatric patients who underwent liver biopsy. 55 patients, age 3-21 years, had biopsy-confirmed NAFLD. We assessed primary outcomes, NAFLD activity score (NAS) and fibrosis scores, against non-invasive parameters by linear regression, by using binary cutoff values, and by a multivariate logistic regression fibrosis prediction model. NAS correlated with platelets and female sex. Fibrosis scores correlated with platelet counts, gamma glutamyl transferase (GGT), and ultrasound shear wave velocity. 25-hydroxy-vitamin D and GGT differentiated mild versus moderate-to-advanced fibrosis. Our multivariate logistical regression model-based scoring system predicted F2 or higher (parameters: BMI%, vitamin D, platelets, GGT), with sensitivity and specificity of 0.83 and 0.95 (area under the ROC curve, 0.944). We identify a clinical model to identify high-risk patients for expedited biopsy. Stratifying patients to abbreviate time-to-biopsy can attenuate delays in aggressive therapy for high-risk patients.

Program Evaluation Through the Use of Logic Models

INTRODUCTION

In order to effectively design and evaluate the effectiveness of a new clinical program or intervention, pharmacists must be equipped with the skills and knowledge that are obtained by familiarity and use of a logic model. Currently, most pharmacy school curricula do not include logic model exercises to instill these necessary skills into the knowledge base of doctor of pharmacy students. This report provides understanding of how a logic model can be permanently implemented into pharmacy curricula in order to develop critical thinking skills that will allow students to become more well-rounded in their future practice of pharmacy.

METHODS

A 23-point questionnaire was developed by the principal investigator, primarily based on feedback from the student reflection papers and areas of interest with the author's prior experience and use of logic models. They were distributed to assess the knowledge, attitudes, and perspectives of students enrolled or previously enrolled in the course.

RESULTS

Questionnaires were received from 128 students, representing approximately 32% of those provided the opportunity to participate. The majority of students (72.98%) viewed the potential benefits of learning about logic models favorably. Overall, 64.86% of students agreed that the experience gained through constructing their own logic model was an intellectually stimulating activity.

CONCLUSIONS

The logic model is an effective tool that can be used to teach pharmacy students how planned program development would contribute to combating various public health issues.

Long-range ballistic transport of Brown-Zak fermions in graphene superlattices

In quantizing magnetic fields, graphene superlattices exhibit a complex fractal spectrum often referred to as the Hofstadter butterfly. It can be viewed as a collection of Landau levels that arise from quantization of Brown-Zak minibands recurring at rational (p/q) fractions of the magnetic flux quantum per superlattice unit cell. Here we show that, in graphene-on-boron-nitride superlattices, Brown-Zak fermions can exhibit mobilities above 10⁶ cm² V⁻¹ s⁻¹ and the mean free path exceeding several micrometers. The exceptional quality of our devices allows us to show that Brown-Zak minibands are 4q times degenerate and all the degeneracies (spin, valley and mini-valley) can be lifted by exchange interactions below 1 K. We also found negative bend resistance at 1/q fractions for electrical probes placed as far as several micrometers apart. The latter observation highlights the fact that Brown-Zak fermions are Bloch quasiparticles propagating in high fields along straight trajectories, just like electrons in zero field.

Here, the authors show that Brown-Zak fermions in graphene-on-boron-nitride superlattices exhibit mobilities above 10⁶ cm²/V s and micrometer scale ballistic transport.

Interaction between physical activity and polygenic risk score for type-2 diabetes in older Americans

Background

Genetics plays an important role in the development of type-2 diabetes (T2D). Polygenic risk scores (PRS) are increasingly used to quantify genetic risk of T2D in epidemiological studies. These scores, when integrated into analyses of modifiable lifestyle factors, may improve understanding of T2D etiology, as the strength of association with T2D and some lifestyle or demographic factors may vary according to genetic predisposition.

Methods

We examined PRS-lifestyle factor interactions on T2D with data from the United States Health and Retirement Study (HRS), a prospective longitudinal cohort of older adults (≥50 at baseline). HRS contains nationally representative samples of Black and White Americans with pre-calculated PRS for T2D (N = 14,001). Covariates included sex, education, BMI, smoking, alcohol, and physical activity. Predicted prevalence and incidence of T2D were calculated with logistic regression models. Nonparametric bootstrap method was performed to calculate differences in T2D prevalence and incidence by PRS percentiles and interaction variables.

Results

Significant interaction (p_interaction=0.0096) was detected between PRS and physical activity among Whites only. In those with the lowest decile of PRS, T2D prevalence was similar (∼10%) for those reporting no physical activity compared to low or moderate activity. In those with the top decile of PRS, lower T2D prevalence (17%, 95%CI:14.8,19.6) was observed among those with moderate compared to no activity (24%, 95%CI:20.4,27.5). Incident T2D in Whites followed a similar pattern (p_interaction=0.0194). Among Black participants, no significant interaction with any lifestyle variables was detected.

Conclusions

Interaction of different genetic risk profiles with lifestyle factors may inform understanding of why certain inventions are more or less effective in different groups of people, potentially improving clinical and prevention interventions.

Key messages

Protection conferred by physical activity on T2D varied by underlying genetic risk. Gene-environment interaction studies provide insights on why lifestyle factors vary in their associations with T2D.

Developmental Programming of NAFLD by Parental Obesity

The surge of obesity across generations has become an increasingly relevant issue, with consequences for associated comorbidities in offspring. Data from longitudinal birth cohort studies support an association between maternal obesity and offspring nonalcoholic fatty liver disease (NAFLD), suggesting that perinatal obesity or obesogenic diet exposure reprograms offspring liver and increases NAFLD susceptibility. In preclinical models, offspring exposed to maternal obesogenic diet have increased hepatic steatosis after diet-induced obesity; however, the implications for later NAFLD development and progression are still unclear. Although some models show increased NAFLD incidence and progression in offspring, development of nonalcoholic steatohepatitis with fibrosis may be model dependent. Multigenerational programming of NAFLD phenotypes occurs after maternal obesogenic diet exposure; however, the mechanisms for such programming remain poorly understood. Likewise, emerging data on the role of paternal obesity in offspring NAFLD development reveal incomplete mechanisms. This review will explore the impact of parental obesity and obesogenic diet exposure on offspring NAFLD and areas for further investigation, including the impact of parental diet on disease progression, and consider potential interventions in preclinical models.

A maternal high-fat, high-sucrose diet induces transgenerational cardiac mitochondrial dysfunction independently of maternal mitochondrial inheritance

Maternal obesity is correlated with cardiovascular disease in offspring, with a 1.3-fold increase in events observed in offspring of obese women. We have observed that obesity-exposed oocytes demonstrate impaired mitophagy and transmit damaged mitochondria to the offspring. Accordingly, we hypothesized that maternal obesity induces cardiac mitochondrial dysfunction in the offspring via transgenerational inheritance of abnormal oocyte mitochondria. We mated female mice fed a high-fat/high-sucrose (HFS) diet (or chow) with chow-fed males and assessed cardiac structure and function in their descendants that were chow fed in each generation. All F1 to F3 descendants bred via the female in each generation were nonobese and demonstrated cardiac mitochondrial abnormalities with crystal rarefaction and reduced oxygen consumption pointing to a transgenerational effect, while obese F0 dams' hearts were unaffected. Furthermore, male offspring from F1 to F3 generations and female F1 and F2 offspring developed increased left ventricular (LV) mass (vs. chow-fed controls). Increased LV mass was also observed in offspring generated by in vitro fertilization of obesity-exposed oocytes and gestation in nonobese surrogates, ruling out a gestational environment effect. Contrary to our hypothesis, male F1 also transmitted these effects to their offspring, ruling out maternal mitochondria as the primary mode of transmission. We conclude that transmission of obesity-induced effects in the oocyte nucleus rather than abnormal mitochondria underlie transgenerational inheritance of cardiac mitochondrial defects in descendants of obese females. These findings will spur exploration of epigenetic alterations in the oocyte genome as potential mechanisms whereby a family history of maternal obesity predisposes to cardiovascular disease in humans.

Transgenerational impact of maternal obesogenic diet on offspring bile acid homeostasis and nonalcoholic fatty liver disease

Studies show maternal obesity is a risk factor for metabolic syndrome and nonalcoholic fatty liver disease (NAFLD) in offspring. Here we evaluated potential mechanisms underlying these phenotypes. Female C57Bl6 mice were fed chow or an obesogenic high-fat/high-sucrose (HF/HS) diet with subsequent mating of F1 and F2 female offspring to lean males to develop F2 and F3 generations, respectively. Offspring were fed chow or fibrogenic (high transfat, cholesterol, fructose) diets, and histopathological, metabolic changes, and bile acid (BA) homeostasis was evaluated. Chow-fed F1 offspring from maternal HF/HS lineages (HF/HS) developed periportal fibrosis and inflammation with aging, without differences in hepatic steatosis but increased BA pool size and shifts in BA composition. F1, but not F2 or F3, offspring from HF/HS showed increased steatosis on a fibrogenic diet, yet inflammation and fibrosis were paradoxically decreased in F1 offspring, a trend continued in F2 and F3 offspring. HF/HS feeding leads to increased periportal fibrosis and inflammation in chow-fed offspring without increased hepatic steatosis. By contrast, fibrogenic diet-fed F1 offspring from HF/HS dams exhibited worse hepatic steatosis but decreased inflammation and fibrosis. These findings highlight complex adaptations in NAFLD phenotypes with maternal diet.

Gate-Defined Quantum Confinement in InSe-Based van der Waals Heterostructures

Indium selenide, a post-transition metal chalcogenide, is a novel two-dimensional (2D) semiconductor with interesting electronic properties. Its tunable band gap and high electron mobility have already attracted considerable research interest. Here we demonstrate strong quantum confinement and manipulation of single electrons in devices made from few-layer crystals of InSe using electrostatic gating. We report on gate-controlled quantum dots in the Coulomb blockade regime as well as one-dimensional quantization in point contacts, revealing multiple plateaus. The work represents an important milestone in the development of quality devices based on 2D materials and makes InSe a prime candidate for relevant electronic and optoelectronic applications.

Myxedema Coma Secondary to Central Hypothyroidism: A Rare but Real Cause of Altered Mental Status in Pediatrics

BACKGROUND

Myxedema coma (MC), a medical emergency defined as severe hypothyroidism leading to altered mental status, is more common in older women with hypothyroidism.

METHODS/RESULTS

A 7-year-old Caucasian male with chromosome 1q deletion presented with altered mental status preceded by milestone regression. His presenting labs results were: thyroid-stimulating hormone (TSH) 0.501 μIU/ml and free thyroxine (T4) <0.5 ng/dl. His morning cortisol level was 8.1 μg/dl with repeat testing, while TSH was 1.119 μIU/ml and free T4 was 0.5 ng/dl. Low-dose cosyntropin test showed baseline and peak cortisol levels of 1.9 and 16 μg/dl, respectively. Aside from altered mental status, heart block was present in addition to hypothermia and hypercarbia. Diffuse cerebral cortical and corpus callosum atrophy were seen on MRI. An intravenous (i.v.) stress dose of hydrocortisone was administered for 24 h prior to an i.v. loading dose of levothyroxine. His activity level subsequently returned to baseline within 48 h after treatment had been initiated.

CONCLUSION

Though MC is rare, occurring mainly with noncompliance in primary hypothyroidism, it may occur at the diagnosis of secondary hypothyroidism. Based on features like hypothermia, hypoventilation, and cardiovascular instability occurring in the setting of central hypothyroidism, it should be suspected and managed urgently in order to avert the associated high mortality resulting from treatment delays.

β-Catenin regulation of farnesoid X receptor signaling and bile acid metabolism during murine cholestasis

Cholestatic liver diseases result from impaired bile flow and are characterized by inflammation, atypical ductular proliferation, and fibrosis. The Wnt/β-catenin pathway plays a role in bile duct development, yet its role in cholestatic injury remains indeterminate. Liver-specific β-catenin knockout mice and wild-type littermates were subjected to cholestatic injury through bile duct ligation or short-term exposure to 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet. Intriguingly, knockout mice exhibit a dramatic protection from liver injury, fibrosis, and atypical ductular proliferation, which coincides with significantly decreased total hepatic bile acids (BAs). This led to the discovery of a role for β-catenin in regulating BA synthesis and transport through regulation of farnesoid X receptor (FXR) activation. We show that β-catenin functions as both an inhibitor of nuclear translocation and a nuclear corepressor through formation of a physical complex with FXR. Loss of β-catenin expedited FXR nuclear localization and FXR/retinoic X receptor alpha association, culminating in small heterodimer protein promoter occupancy and activation in response to BA or FXR agonist. Conversely, accumulation of β-catenin sequesters FXR, thus inhibiting its activation. Finally, exogenous suppression of β-catenin expression during cholestatic injury reduces β-catenin/FXR complex activation of FXR to decrease total BA and alleviate hepatic injury.

CONCLUSION

We have identified an FXR/β-catenin interaction whose modulation through β-catenin suppression promotes FXR activation and decreases hepatic BAs, which may provide unique therapeutic opportunities in cholestatic liver diseases. (Hepatology 2018;67:955-971).

Room-Temperature Mid-Infrared Emission from Faceted InAsSb Multi Quantum Wells Embedded in InAs Nanowires

There is considerable interest in the development of InAsSb-based nanowires for infrared photonics due to their high tunability across the infrared spectral range, high mobility, and integration with silicon electronics. However, optical emission is currently limited to low temperatures due to strong nonradiative Auger and surface recombination. Here, we present a new structure based on conical type II InAsSb/InAs multiquantum wells within InAs nanowires which exhibit bright mid-infrared photoluminescence up to room temperature. The nanowires are grown by catalyst-free selective area epitaxy on silicon. This unique geometry confines the electron-hole recombination to within the quantum wells which alleviates the problems associated with recombination via surface states, while the quantum confinement of carriers increases the radiative recombination rate and suppresses Auger recombination. This demonstration will pave the way for the development of new integrated quantum light sources operating in the technologically important mid-infrared spectral range.

Elevation of circulating microRNA levels in obese children compared to healthy controls

As childhood obesity increases, it is becoming important to understand the complications of obesity in children and develop novel biomarkers. Evidence indicates that microRNAs (miRNA) are dys-regulated in obesity and may serve as sensitive and specific circulating biomarkers. Non-alcoholic fatty liver disease (NAFLD) is a complication of obesity that ultimately requires a liver biopsy to determine disease severity. While studies have been conducted in adults, no study to date has examined circulating miRNAs in children with obesity and NAFLD. The goal of this study was to evaluate a panel of selected circulating miRNAs in obese children compared to healthy controls. We present here an analysis of a pre-selected panel of 20 candidate miRNAs in obese children compared to healthy controls. The miRNAs were chosen based on having been previously reported to be involved in NAFLD. We found that 16 out of 20 miRNAs tested were elevated at least twofold in children with obesity compared to controls. miR-122 and miR-199a showed the greatest increase in children with obesity versus controls. Both also had a high area under the curve when receiver-operator curves were plotted. Several circulating miRNAs correlated with body mass index (BMI) or serum transaminases. This study provides initial evidence that circulating miRNAs can be measured in the paediatric population and provides several diagnostic candidates increased in children with obesity that may be relevant to NAFLD.

Maternal high fat diet exposure is associated with increased hepcidin levels, decreased myelination, and neurobehavioral changes in male offspring

Maternal obesity induces chronic inflammatory responses that impact the fetus/neonate during the perinatal period. Inflammation, iron regulation, and myelination are closely interconnected and disruptions in these processes may have deleterious effects on neurodevelopment. Hepcidin levels are increased in response to inflammation causing subsequent decreases in ferroportin and available iron needed for myelination. Our current studies were designed to test the hypotheses that: 1) maternal high fat diet (HFD) prior to and during pregnancy is sufficient to induce inflammation and alter iron regulation in the brain of the offspring, and 2) HFD exposure is associated with altered myelination and neurobehavioral deficits in the offspring. Our data revealed modest increases in inflammatory cytokines in the serum of dams fed HFD prior to pregnancy compared to dams fed a control diet (CD). Early increases in IL-5 and decreases in IL-10 were observed in serum at PN7 while IL-5 remained elevated at PN21 in the HFD-exposed pups. At PN0, most cytokine levels in whole brain homogenates were higher in the pups born to HFD-fed dams but were not different or were lower than in pups born to CD-fed dams at PN21. Conversely, the inflammation mediated transcription factor Nurr77 remained elevated at PN21. At birth, brain hepcidin, ferroportin, and l-ferritin levels were elevated in pups born to HFD-fed dams compared to pups born to CD-fed dams. Hepcidin levels remained elevated at PN7 and PN21 while ferroportin and l-ferritin levels were lower at PN7 and were not different at PN21. Decreases in myelination in the medial cortex were observed in male but not in female pups born to maternal HFD-fed dams at PN21. These structural changes correlated with changes in behavior (novel object recognition) in at 4months in males only. Our data indicate that maternal obesity (HFD) results in disruption of iron regulation in the brains of the offspring with structural and neurobehavioral deficits in males.

Addressing Nonadherence in the Schizophrenic Population

Nonadherence within the schizophrenic population is a challenge for both the patient and the clinician. This problem not only causes an increase in health care use and cost but also places the patient at risk of relapse and dissatisfaction with medical care. Nonadherence is influenced by several factors including disease, treatment, and psychological and social factors. All of these factors must be addressed if the clinician hopes to reduce nonadherence within this patient population. This article will attempt to identify factors that contribute to nonadherence and review strategies that can be implemented to address each of these factors.

Abstract P3-11-04: Metabolic profiles in female Sprague-Dawley rats receiving either a standard (4% fat) or Western (20% fat) diet and changes in rats bearing mammary cancers

The methylnitrosourea(MNU)-induced model of ER+ mammary cancers in female Sprague-Dawley rats has been routinely used in our laboratories for screening chemopreventive agents. We recently reported that metformin was ineffective in preventing mammary cancers in this model when given to rats on a standard diet (Thompson, et al, Cancer Prev Res. 2015;8:231-9). In this study, we evaluated metformin in rats placed on either standard diet (4% fat) or a Western diet (20% fat, low calcium). As fat calories, these diets were 8% and 42%, respectively. The rats were placed on standard diet or Western diet at 43 days of age, given MNU (via the jugular vein) once at 50 days of age, and administered metformin or vehicle at 57 days of age for the remainder of the study. Serum of the rats in the various groups was obtained at 78 days of age, and at the end of the study (when mammary tumors were present). The levels of approximately 500 metabolites were compared in the serum based on data obtained by Metabolon (Research Triangle Park, NC). These studies showed that each of the four groups [(standard diet (early and late) or Western diet (early and late)] yielded four clearly distinct patterns based on an unsupervised principal component analysis. Certain of the metabolites which were differentially expressed in serum from standard vs Western diets at the early time point were alpha-10-undecanoate, 13-methylmyristic acid, 4-hydroxy-benzoate, 2-amino-heptanpate, tocopherol, and nicotinamide. Certain of these were fatty acids and lipid soluble vitamins that one would expect to be altered. Comparing serum from standard vs Western diets at the late time point confirmed many of these metabolic differences. We also compared serum from the early and late time points since the latter serums were typically from animals with a significant number of mammary cancers. We observed a number of metabolite changes including 4-hydroxy-butyrate, acetyl-carnitine, oxalate, and threonate. These cancer- related profiles will be discussed at greater lengths. Altered profiles caused by the administration of metformin and other chemopreventive agents will also be discussed. Of interest, metformin was consistently ineffective in preventing mammary cancers in rats given either standard or Western diet. Supported by NCI contract HHSN261201200021I.

Citation Format: Thompson MD, Grubbs CJ, Moeinpour F, Steele VE, Miller MS, Lubet RA. Metabolic profiles in female Sprague-Dawley rats receiving either a standard (4% fat) or Western (20% fat) diet and changes in rats bearing mammary cancers. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-11-04.

Low Leakage-Current InAsSb Nanowire Photodetectors on Silicon

Axially doped p-i-n InAs0.93Sb0.07 nanowire arrays have been grown on Si substrates and fabricated into photodetectors for shortwave infrared detection. The devices exhibit a leakage current density around 2 mA/cm(2) and a 20% cutoff of 2.3 μm at 300 K. This record low leakage current density for InAsSb based devices demonstrates the suitability of nanowires for the integration of III-V semiconductors with silicon technology.

Enhanced Steatosis and Fibrosis in Liver of Adult Offspring Exposed to Maternal High-Fat Diet

Early life exposures can increase the risk of developing chronic diseases including nonalcoholic fatty liver disease. Maternal high-fat diet increases susceptibility to development of steatosis in the offspring. We determined the effect of maternal high-fat diet exposure in utero and during lactation on offspring liver histopathology, particularly fibrosis. Female C57Bl/6J mice were fed a control or high-fat diet (HFD) for 8 weeks and bred with lean males. Nursing dams were continued on the same diet with offspring sacrificed during the perinatal period or maintained on either control or high-fat diet for 12 weeks. Increased hepatocyte proliferation and stellate cell activation were observed in the liver of HFD-exposed pups. Offspring exposed to perinatal high-fat diet and high-fat diet postweaning showed extensive hepatosteatosis compared to offspring on high-fat diet after perinatal control diet. Offspring exposed to perinatal high-fat diet and then placed on control diet for 12 weeks developed steatosis and pericellular fibrosis. Importantly, we found that exposure to perinatal high-fat diet unexpectedly promotes more rapid disease progression of nonalcoholic fatty liver disease, with a sustained fibrotic phenotype, only in adult offspring fed a postweaning control diet.

Severe hyponatraemia with absence of hyperkalaemia in rapidly progressive Addison's disease

We present a case of rapidly progressing Addison's disease in adrenal crisis with severe hyponatraemia and absence of hyperkalaemia in a 10-year-old girl. She presented with 2 weeks of vomiting, fatigue and weight loss. Her serum electrolytes obtained 1 week prior to presentation were normal, except for mild hyponatraemia at 131 mmol/L, which dropped to 112 mmol/L on admission. She had normal serum potassium, low-serum osmolality, with elevated urine sodium and osmolality, indistinguishable from syndrome of inappropriate antidiuretic hormone (SIADH). Subsequently, Addison's disease was diagnosed on the basis of gingival hyperpigmentation and undetectable cortisol on adrenocorticotropic hormone stimulation test. She rapidly responded to stress dose hydrocortisone, followed by hydrocortisone and fludrocortisone replacement therapy. The absence of hyperkalaemia in the presence of severe hyponatraemia cannot rule out Addison's disease in children. The mechanism of hypo-osmolar hyponatraemia in primary adrenal insufficiency and clinical clues to differentiate it from SIADH are discussed.

Spontaneous repopulation of β-catenin null livers with β-catenin-positive hepatocytes after chronic murine liver injury

Prolonged exposure of mice to diet containing 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) results in hepatobiliary injury, atypical ductular proliferation, oval cell appearance, and limited fibrosis. Previously, we reported that short-term ingestion of DDC diet by hepatocyte-specific β-catenin conditional knockout (KO) mice led to fewer A6-positive oval cells than wildtype (WT) littermates. To examine the role of β-catenin in chronic hepatic injury and repair, we exposed WT and KO mice to DDC for 80 and 150 days. Paradoxically, long-term DDC exposure led to significantly more A6-positive cells, indicating greater atypical ductular proliferation in KO, which coincided with increased fibrosis and cholestasis. Surprisingly, at 80 and 150 days in KO we observed a significant amelioration of hepatocyte injury. This coincided with extensive repopulation of β-catenin null livers with β-catenin-positive hepatocytes at 150 days, which was preceded by appearance of β-catenin-positive hepatocyte clusters at 80 days and a few β-catenin-positive hepatocytes at earlier times. Intriguingly, occasional β-catenin-positive hepatocytes that were negative for progenitor markers were also observed at baseline in the KO livers, suggesting spontaneous escape from cre-mediated recombination. These cells with hepatocyte morphology expressed mature hepatocyte markers but lacked markers of hepatic progenitors. The gradual repopulation of KO livers with β-catenin-positive hepatocytes occurred only following DDC injury and coincided with a progressive loss of hepatic cre-recombinase expression. A few β-catenin-positive cholangiocytes were observed albeit only after long-term DDC exposure and trailed the appearance of β-catenin-positive hepatocytes.

CONCLUSION

In a chronic liver injury model, β-catenin-positive hepatocytes exhibit growth and survival advantages and repopulate KO livers, eventually limiting hepatic injury and dysfunction despite increased fibrosis and intrahepatic cholestasis.

Pegylated interferon alpha targets Wnt signaling by inducing nuclear export of β-catenin

BACKGROUND & AIMS

Pegylated-Interferon-α2a (peg-IFN), a first line therapy for Hepatitis C virus (HCV) patients, also impacts the recurrence of hepatocellular carcinoma (HCC). The activation of the Wnt pathway due to β-catenin gene mutations contributes to the development of a significant subset of HCC. Herein, we explored the effect of peg-IFN on Wnt/β-catenin signaling in vitro and in vivo.

METHODS

Multiple human hepatoma cell lines were treated with Peg-IFN to assess its effect on the Wnt pathway and the mechanisms involved. Transgenic (TG) mice expressing stable β-catenin mutant in the liver were exposed to diethylnitrosamine (DEN) and treated with peg-IFN.

RESULTS

In vitro, peg-IFN decreased the transcriptional activity of β-catenin/Tcf and did so independently of JAK/Stat signaling. Peg-IFN treatment led to increased mRNA and protein expression of RanBP3, a known β-catenin nuclear export factor, in all hepatoma cells. Co-precipitation studies showed an increased association between RanBP3 and β-catenin after peg-IFN treatment. The siRNA-mediated RanBP3 knockdown abrogated Peg-IFN-induced decrease in TOPFlash reporter activity. In vivo, Peg-IFN treatment led to increased nuclear RanBP3, decreased nuclear β-catenin and cyclin D1, and decreased cytoplasmic glutamine synthetase. Increased association of RanBP3 and β-catenin was also observed in vivo in response to Peg-IFN that led to decreased hepatocyte proliferation.

CONCLUSIONS

Peg-IFN inhibits β-catenin signaling through the up-regulation of RanBP3, which may be a contributory mechanism for the delayed HCC and improved survival in treated HCV patients. This observation might have chemo-preventive or chemo-therapeutic implications in tumor with aberrant Wnt pathway activation.

Disparate cellular basis of improved liver repair in beta-catenin-overexpressing mice after long-term exposure to 3,5-diethoxycarbonyl-1,4-dihydrocollidine

Administration of a hepatotoxic diet containing 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) induces biliary damage followed by hepatocyte injury, which is repaired through atypical ductular proliferation and oval cells and their subsequent differentiation to bile duct cells and hepatocytes. In this study, we examine whether excess β-catenin in transgenic (TG) mice would provide any reparative advantage in response to DDC. No differences in appearance or numbers of total A6-positive oval cells were observed after DDC administration. However, an increase in A6-positive "atypical hepatocytes" in the TG livers was observed after 14 and 28 days, coinciding with an increase in proliferating cell nuclear antigen-positive hepatocytes. Intriguingly, after chronic DDC administration for 150 days, a further increase in atypical hepatocytes was evident in TG mice, with higher numbers of proliferating cell nuclear antigen-positive hepatocytes exhibiting cytoplasmic/nuclear β-catenin and α-fetoprotein but not CK19, HNF1β, or Trop-2. Coincidently, we observed an improvement in intrahepatic cholestasis as seen by decreases in both serum bilirubin and alkaline phosphatase levels in TG mice, indicating an overall improvement in hepatic repair. TG mice exposed to DDC for 4 weeks followed by 2 days of normal chow showed decreases in alkaline phosphatase, atypical ductular proliferation, and periportal inflammation compared with wild-type animals, verifying improved biliary repair in TG livers. Thus, we report a potential role of β-catenin in liver repair, especially in enhancing the resolution of intrahepatic cholestasis after DDC injury.

Accelerated liver regeneration and hepatocarcinogenesis in mice overexpressing serine-45 mutant beta-catenin

The Wnt/beta-catenin pathway is implicated in the pathogenesis of hepatocellular cancer (HCC). We developed a transgenic mouse (TG) in the FVB strain that overexpresses Ser45-mutated-beta-catenin in hepatocytes to study the effects on liver regeneration and cancer. In the two independent TG lines adult mice show elevated beta-catenin at hepatocyte membrane with no increase in the Wnt pathway targets cyclin-D1 or glutamine synthetase. However, TG hepatocytes upon culture exhibit a 2-fold increase in thymidine incorporation at day 5 (D5) when compared to hepatocytes from wildtype FVB mice (WT). When subjected to partial hepatectomy (PH), dramatic increases in the number of hepatocytes in S-phase are evident in TG at 40 and WT at 72 hours. Coincident with the earlier onset of proliferation, we observed nuclear translocation of beta-catenin along with an increase in total and nuclear cyclin-D1 protein at 40 hours in TG livers. To test if stimulation of beta-catenin induces regeneration, we used hydrodynamic delivery of Wnt-1 naked DNA to control mice, which prompted an increase in Wnt-1, beta-catenin, and known targets, glutamine synthetase (GS) and cyclin-D1, along with a concomitant increase in cell proliferation. beta-Catenin-overexpressing TG mice, when followed up to 12 months, showed no signs of spontaneous tumorigenesis. However, intraperitoneal delivery of diethylnitrosamine (DEN), a known carcinogen, induced HCC at 6 months in TG mice only. Tumors in TG livers showed up-regulation of beta-catenin, cyclin-D1, and unique genetic aberrations, whereas other canonical targets were unremarkable.

CONCLUSION

beta-Catenin overexpression offers growth advantage during liver regeneration. Also, whereas no spontaneous HCC is evident, beta-catenin overexpression makes TG mice susceptible to DEN-induced HCC.

Beta-catenin deletion in hepatoblasts disrupts hepatic morphogenesis and survival during mouse development

Beta-catenin, the central component of the canonical Wnt pathway, plays important roles in the processes of liver regeneration, growth, and cancer. Previously, we identified temporal expression of beta-catenin during liver development. Here, we characterize the hepatic phenotype, resulting from the successful deletion of beta-catenin in the developing hepatoblasts utilizing Foxa3-cyclization recombination and floxed-beta-catenin (exons 2 through 6) transgenic mice. Beta-catenin loss in developing livers resulted in significantly underdeveloped livers after embryonic day 12 (E12) with lethality occurring at around E17 stages. Histology revealed an overall deficient hepatocyte compartment due to (1) increased cell death due to oxidative stress and apoptosis, and (2) diminished expansion secondary to decreased cyclin-D1 and impaired proliferation. Also, the remnant hepatocytes demonstrated an immature phenotype as indicated by high nuclear to cytoplasmic ratio, poor cell polarity, absent glycogen, and decreased expression of key liver-enriched transcription factors: CCAAT-enhancer binding protein-alpha and hepatocyte nuclear factor-4alpha. A paucity of primitive bile ducts was also observed. While the stem cell assays demonstrated no intrinsic defect in hematopoiesis, distorted hepatic architecture and deficient hepatocyte compartments resulted in defective endothelial cell organization leading to overall fetal pallor.

CONCLUSION

Beta-catenin regulates multiple, critical events during the process of hepatic morphogenesis, including hepatoblast maturation, expansion, and survival, making it indispensable to survival.

Wnt/beta-catenin signaling mediates oval cell response in rodents

Adult hepatic stem cells or oval cells are facultative stem cells in the liver that are activated during regeneration only during inhibition of innate hepatocyte proliferation. On the basis of its involvement in liver cancer, regeneration, and development, we investigated the role of the Wnt/beta-catenin pathway in oval cell response, which was initiated in male Fisher rats with 2-acetylaminofluorine and two-third partial hepatectomy (PHX). Extensive oval cell activation and proliferation were observed at 5 and 10 days post-PHX, as indicated by hematoxylin-eosin and proliferating cell nuclear antigen analysis. A noteworthy increase in total and active beta-catenin was observed at this time, which was localized to the oval cell cytoplasm and nuclei by immunohistochemistry and confirmed by double immunofluorescence. A concomitant increase in Wnt-1 in hepatocytes along with increased expression of Frizzled-2 in oval cells was observed. This paracrine mechanism coincided with a decrease in Wnt inhibitory factor-1 and glycogen synthase kinase-3beta down-regulation leading to beta-catenin stabilization. To strengthen its role, beta-catenin conditional knockout mice were treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine to induce oval cell activation. A dramatic decrease in the A6-positive oval cell numbers in the absence of beta-catenin demonstrated a critical role of beta-catenin in oval cell biology.

CONCLUSION

The Wnt/beta-catenin pathway plays a key role in the normal activation and proliferation of adult hepatic stem cells.

beta-Catenin is critical for early postnatal liver growth

The Wnt/beta-catenin pathway plays an important role in embryonic liver development, morphogenesis, and organogenesis. Here, we report on the activation of beta-catenin during early postnatal liver growth. Modulation of beta-catenin expression was studied in CD-1 mice livers over a time course of 0 to 30 postnatal days (PD) and 3 mo. Increases in total and active beta-catenin were observed in developing livers from PD 5 to 20. A concomitant increase in the beta-catenin-transcription factor (TCF) complex along with nuclear and cytoplasmic beta-catenin was also evident, which coincided with ongoing hepatocyte proliferation by PCNA immunohistochemistry. This activation of beta-catenin was multifactorial, including cyclical inhibition of glycogen synthase kinase-3beta, suppression of casein kinase-IIalpha, and a transient increase in beta-catenin gene expression. Coprecipitation experiments revealed the formation of the beta-catenin-cadherin complex at PD 5, whereas adequate beta-catenin-c-Met complex at the hepatocyte membrane did not form until PD 20, which might be contributing to the free beta-catenin pool during early postnatal growth. Furthermore, beta-catenin liver-specific knockout mice exhibited smaller livers at PD 30, secondary to diminished hepatocyte proliferation. These data indicate that the activation of beta-catenin is critical for early postnatal liver growth and development.

WNT/beta-catenin signaling in liver health and disease

Wnt/beta-catenin signaling is emerging as a forerunner for its critical roles in many facets of human biology. Its roles in embryogenesis, organogenesis, and maintaining tissue and organ homeostasis demonstrate its munificent character. Its roles in pathological conditions such as cancer and other human disorders such as inflammatory disorders and fibrosis reveal its villainous disposition. In liver, it also maintains its dual personality and is clearly of essence in several physiological events such as development, regeneration, and growth. Its aberrant activation is also evident in many different tumors of the liver, and recent studies are beginning to identify its role in additional hepatic pathological conditions. It is contributing to liver physiology and pathology by regulating various basic cellular events, including differentiation, proliferation, survival, oxidative stress, morphogenesis, and others. This review discusses the contribution of the Wnt/beta-catenin signaling pathway in these events and simultaneously provides an essential overview of the major developments in the field of Wnt/beta-catenin and liver pathobiology. In addition, areas that are currently deficient or understudied are identified and discussed along with the avenues of translational and clinical relevance.

R-Etodolac decreases beta-catenin levels along with survival and proliferation of hepatoma cells

BACKGROUND/AIMS

Inhibition of hepatoma cells by cyclooxygenase (COX)-2-dependent and -independent mechanisms has been shown previously. Here, we examine the effect of Celecoxib, a COX-2-inhibitor and R-Etodolac, an enantiomer of the nonsteroidal anti-inflammatory drug Etodolac, which lacks COX-inhibitory activity, on the Wnt/beta-catenin pathway and human hepatoma cells.

METHODS

Hep3B and HepG2 cell lines were treated with Celecoxib or R-Etodolac, and examined for viability, DNA synthesis, Wnt/beta-catenin pathway components, and downstream target gene expression.

RESULTS

Celecoxib at high doses affected beta-catenin protein by inducing its degradation via GSK3beta and APC along with diminished tumor cell proliferation and survival. R-Etodolac at physiological doses caused decrease in total and activated beta-catenin protein secondary to decrease in its gene expression and post-translationally through GSK3beta activation. In addition, increased beta-catenin-E-cadherin was also observed at the membrane. An associated inhibition of beta-catenin-dependent Tcf reporter activity, decreased levels of downstream target gene products glutamine synthetase and cyclin-D1, and decreased proliferation and survival of hepatoma cells was evident.

CONCLUSIONS

The antitumor effects of Celecoxib (at high concentrations) and R-Etodolac (at physiological doses) on HCC cells were accompanied by the down-regulation of beta-catenin demonstrating a useful therapeutic strategy in hepatocellular cancer.

Evaluating operative risk in colorectal cancer surgery: ASA and POSSUM-based predictive models

OBJECTIVE

To review two predictive models, based on the American Society of Anaesthesiologists (ASA) and the Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (POSSUM)-used for estimating postoperative mortality in patients, undergoing surgery for colorectal disease, in the UK.

METHODS

Data was derived from three multicentre, UK-based studies involving a total of 16,006 patients with malignant or non-malignant bowel pathologies. Data sources were: The Colorectal-POSSUM (CR-POSSUM) Study population, comprising 6883 patients undergoing colorectal surgery in 15 UK hospitals between 1993 and 2001; The Association of Coloproctology of Great Britain and Ireland (ACPGBI) Colorectal Cancer (CRC) Database, encompassing 8077 newly diagnosed CRC patients, undergoing surgical resections in 79 hospitals, between April 2000 and March 2002; The ACPGBI Malignant Bowel Obstruction (MBO) Study, encompassing 1046 patients with MBO in 148 hospitals, treated between April 1998 and March 1999. Multifactorial logistic regression analyses were used to adjust for case-mix, identify risk factors for in-hospital/30-day operative mortality and to accommodate the variability of outcomes between hospitals.

RESULTS

In the ACPGBI CRC study, 7374 patients had surgery, 6622(89.8%) a major bowel resection and 1465(19.9%) emergency surgery. Nine hundred and eighty-nine (94.6%) patients with MBO had surgery and 854(86.3%) underwent bowel resection. In the CR-POSSUM study, of the 6790(98.6%) patients undergoing surgery, 3451(50.8%) had a major colorectal resection, including 2107(31.0%) as an emergency. The operative mortality was 7.5% for the ACPGBI CRC study, 15.7% for patients with MBO and 5.7% for patients in the CR-POSSUM study. When tested, the predictive models showed good discrimination, with an area under the receiver-operator characteristic curve of 77.5% for the ACPGBI CRC, 80.1% for the MBO and 89.8% for the CR-POSSUM.

CONCLUSIONS

Prediction of postoperative death can be made by the clinician using simple, numerical, tables derived from the ACPGBI CRC, MBO and CR-POSSUM models. The models can be used in everyday practice for pre-operative counselling of patients and their carers, as a part of the process of informed consent. They may also be used to compare the outcomes between multidisciplinary CRC teams.