Liver Glucose Research Articles

Effects of Rumen-Protected Creatine Pyruvate on Meat Quality, Hepatic Gluconeogenesis, and Muscle Energy Metabolism of Long-Distance Transported Beef Cattle

Pre-slaughter long-distance transport resulted in a rapid depletion of muscle glycogen and led to a higher rate of dark, firm and dry (DFD) meat. Therefore, enhancing muscle glycogen reserves is critical for beef cattle prior to transportation. Creatine pyruvate (CrPyr) can provide simultaneous pyruvate and creatine and both are proven to promote the glycogen reserves. This study aimed to investigate the effects of transport treatment and dietary supplementation of rumen-protected (RP)-CrPyr on the meat quality, muscle energy metabolism, and hepatic gluconeogenesis of beef cattle. Twenty 18 month-old male Simmental crossbred cattle (659 ± 16 kg) were allotted 4 treatments based on a 2 × 2 factorial arrangement with two RP-CrPyr levels (140 g/d or 0 g/d) and two transport treatments (12 h or 5 min): ST_CrPyr0, ST_CrPyr140, LT_CrPyr0 and LT_CrPyr140. Three cattle per group were slaughtered after 30 days of feeding. The interaction of transport and RP-CrPyr had a significant effect on the muscle pH45 min, redness, glycogen content, GP, and AMP level (P < 0.05). Compared with short-distance transport, long-distance transport increased the muscle pH45 min value, redness, yellowness, drip loss, creatine level (P < 0.05), decreased muscle glycogen content, glycolytic potential (GP), and liver glucose amount (P < 0.05). Supplementation of RP-CrPyr decreased the activities of creatine kinase and lactate dehydrogenase in serum, muscle pH24 h value, redness, yellowness, lactate content, AMP level, and AMP/ATP (P < 0.05), increased the muscle glycogen content, GP, hexokinase activity, ATP and ADP levels, and ATP/ADP, liver pyruvate and glucose contents, activity of pyruvate carboxylase in the liver of cattle than those in the nonsupplemented treatments (P < 0.05). These results indicated that dietary RP-CrPyr supplementation might be favorable to improve meat quality and regulatory capacity of energy metabolism of beef cattle suffering long-distance transport followed with recovery treatment by increasing muscle glycogen storage, energy supply, and hepatic gluconeogenesis.

PAR2 promotes impaired glucose uptake and insulin resistance in NAFLD through GLUT2 and Akt interference.

Insulin resistance and poor glycemic control are key drivers of the development of NAFLD and have recently been shown to be associated with fibrosis progression in NASH. However, the underlying mechanisms involving dysfunctional glucose metabolism and relationship with NAFLD/NASH progression remain poorly understood. We set out to determine whether protease-activated receptor 2 (PAR2), a sensor of extracellular inflammatory and coagulation proteases, links NAFLD and NASH with liver glucose metabolism. Here, we demonstrate that hepatic expression of PAR2 increases in patients and mice with diabetes and NAFLD/NASH. Mechanistic studies using whole-body and liver-specific PAR2-knockout mice reveal that hepatic PAR2 plays an unexpected role in suppressing glucose internalization, glycogen storage, and insulin signaling through a bifurcating Gq -dependent mechanism. PAR2 activation downregulates the major glucose transporter of liver, GLUT2, through Gq -MAPK-FoxA3 and inhibits insulin-Akt signaling through Gq -calcium-CaMKK2 pathways. Therapeutic dosing with a liver-homing pepducin, PZ-235, blocked PAR2-Gq signaling and afforded significant improvements in glycemic indices and HbA1c levels in severely diabetic mice. This work provides evidence that PAR2 is a major regulator of liver glucose homeostasis and a potential target for the treatment of diabetes and NASH.

Prevalence and Risk Factors for Hepatic Steatosis in Children With Perinatal HIV on Early Antiretroviral Therapy Compared to HIV-Exposed Uninfected and HIV-Unexposed Children.

ObjectivesWe evaluated the prevalence and risk factors for hepatic steatosis in South African children with perinatally acquired HIV (PHIV) who started treatment early and remain on long-term antiretroviral therapy (ART) compared to HIV-uninfected children.DesignA cross-sectional study from April 2019 to October 2021. PHIV, HIV-exposed uninfected (HEU) and HIV-unexposed (HU) children were enrolled from an ongoing cohort study.MethodsAll children had transient elastography (TE) with controlled attenuation parameter (CAP). Liver enzymes, lipogram, insulin and glucose were sent after an overnight fast. Multivariable linear regression analyses identified predictors of CAP. Hepatic steatosis was defined as CAP>248kPa.Results215 children (111 [52%] male; median age 14.1 years; IQR 12.7–14.9) participated in the study, 110 PHIV, 105 HIV-uninfected (36 HEU, 69 HU). PHIV initiated ART at a median age of 2.7 months (IQR 1.8–8.5). Hepatic steatosis prevalence was 9% in PHIV, 3% in HEU and 1% in HU children (p = 0.08). However, 8% of lean (body mass index z-score ≤ +1) PHIV had hepatic steatosis compared to zero lean HEU or HU children (p = 0.03). In multivariable linear regression analysis of all PHIV, body mass index (BMI) z-score was positively associated with CAP (p = 0.001) while CD4 count (p = 0.02) and duration of suppression of HIV viraemia (p = 0.009) were negatively associated with CAP, adjusting for age, sex and ethnicity.ConclusionsHepatic steatosis prevalence was higher in lean PHIV than lean HIV-uninfected South African children. Longer suppression of HIV viraemia and higher CD4 count were associated with lower CAP and might be protective factors for hepatic steatosis in PHIV children.

Chrysin Attenuates Fructose-Induced Nonalcoholic Fatty Liver in Rats via Antioxidant and Anti-Inflammatory Effects: The Role of Angiotensin-Converting Enzyme 2/Angiotensin (1-7)/Mas Receptor Axis.

Aim Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome, and if untreated, it may propagate into end-stage liver disease. The classical arm of the renin-angiotensin system (RAS) has a fundamental role in triggering oxidative stress and inflammation, which play potential roles in the pathogenesis of NAFLD. However, the nonclassical alternative axis of RAS, angiotensin- (Ang-) converting enzyme 2 (ACE2)/Ang (1-7)/Mas receptor, opposes the actions of the classical arm, mitigates the metabolic dysfunction, and improves hepatic lipid metabolism rendering it a promising protective target against NAFLD. The current study is aimed at investigating the impact of chrysin, a well-known antioxidant flavonoid, on this defensive RAS axis in NAFLD. Methods Rats were randomly distributed and treated daily for eight weeks as follows: the normal control, chrysin control (50 mg/kg, p.o), NAFLD group (received 20% fructose in drinking water), and treated groups (25 and 50 mg/kg chrysin given orally and concomitantly with fructose). Diminazene aceturate (DIZE) (15 mg/kg, s.c.) was used as a reference ACE2 activator. Key Findings. High fructose induced significant weight gain, hepatocyte degeneration with fat accumulation, and inflammatory cell infiltration (as examined by H&E staining). This was accompanied by a substantial increase in liver enzymes, glucose, circulating and hepatic triglycerides, lipid peroxides, inflammatory cytokines, and Ang II (the main component of classical RAS). At the same time, protein levels of ACE2, Ang (1-7), and Mas receptors were markedly reduced. Chrysin (25 and 50 mg/kg) significantly ameliorated these abnormalities, with a prominent effect of the dose of 50 mg/kg over DIZE and the lower dose in improving ACE2, Ang (1-7), and Mas. Significance. Chrysin is a promising efficient protective remedy against NAFLD; mechanisms include the activation of ACE2/Ang (1-7)/Mas axis.

Urine Proteome in Distinguishing Hepatic Steatosis in Patients with Metabolic-Associated Fatty Liver Disease.

Background: In patients with metabolic-associated fatty liver disease (MAFLD), hepatic steatosis is the first step of diagnosis, and it is a risk predictor that independently predicts insulin resistance, cardiovascular risk, and mortality. Urine biomarkers have the advantage of being less complex, with a lower dynamic range and fewer technical challenges, in comparison to blood biomarkers. Methods: Hepatic steatosis was measured by magnetic resonance imaging (MRI), which measured the proton density fat fraction (MRI-PDFF). Mild hepatic steatosis was defined as MRI-PDFF 5–10% and severe hepatic steatosis was defined as MRI-PDFF > 10%. Results: MAFLD patients with any kidney diseases were excluded. There were 53 proteins identified by mass spectrometry with significantly different expressions among the healthy control, mild steatosis, and severe steatosis patients. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of these significantly changed urinary molecular features correlated with the liver, resulting in the dysregulation of carbohydrate derivative/catabolic/glycosaminoglycan/metabolic processes, insulin-like growth factor receptor levels, inflammatory responses, the PI3K–Akt signaling pathway, and cholesterol metabolism. Urine alpha-1-acid glycoprotein 1 (ORM1) and ceruloplasmin showed the most significant correlation with the clinical parameters of MAFLD status, including liver fat content, fibrosis, ALT, triglycerides, glucose, HOMA-IR, and C-reactive protein. According to ELISA and western blot (30 urine samples, normalized to urine creatinine), ceruloplasmin (ROC 0.78, p = 0.034) and ORM1 (ROC 0.87, p = 0.005) showed moderate diagnostic accuracy in distinguishing mild steatosis from healthy controls. Ceruloplasmin (ROC 0.79, p = 0.028) and ORM1 (ROC 0.81, p = 0.019) also showed moderate diagnostic accuracy in distinguishing severe steatosis from mild steatosis. Conclusions: Ceruloplasmin and ORM1 are potential biomarkers in distinguishing mild and severe steatosis in MAFLD patients.

Effect of potassium supplementation on osmoregulatory and stress response of Pangasianodon hypophthalmus (Sauvage, 1878) with Spinacia oleracea L. in aquaponics.

This study evaluated the effect of different potassium supplementation dosages on the physiological responses of Pangasianodon hypophthalmus reared in an aquaponic system with Spinacia oleracea L. for 60 days. The system comprised of a rectangular fish tank of 168 l capacity (water volume=100 l) with nutrient film technique (NFT)-based hydroponic component with fish to plant ratio of 2.8kg m-3 : 28 plants m-2 in all the treatments. The osmoregulatory and stress parameters of P. hypophthalmus at four different potassium dosages of T1 (90 mg l-1 ), T2 (120 mg l-1 ), T3 (150 mg l-1 ) and T4 (180 mg l-1 ) were compared with C (control, 0mg l-1 ) to examine the potassium level to be applied to aquaponics. The water quality parameters and fish production were found to have no adverse impact due to potassium supplementation. The spinach yield during two harvests, i.e., before and after potassium supplementation, revealed that the yield was significantly higher (P < 0.05) after supplementation with the highest yield in T3 and T4. The osmoregulatory parameters such as plasma osmolality, Na+ , K+ ATPase activity in gill and plasma ionic profile (Cl- , Ca2+ and Na+ ) showed an insignificant variation (P > 0.05) between control and treatments except for higher plasma potassium concentration (1.98 ± 0.19 mmol l-1 ) in T4. The stress and antioxidant enzyme analysis exhibited significantly higher plasma glucose and superoxide dismutase (SOD) activity in gill and liver in T4, whereas cortisol and catalase showed an insignificant difference (P > 0.05). The experimental findings demonstrated that the potassium dosage up to 150 mg l-1 could be suggested as optimum for P. hypophthalmus and spinach aquaponics without impairing the health and oxidative status of P. hypophthalmus.

216-LB: Hepatocyte N6-Methyladenosine mRNA Modification in Hepatic Gluconeogenesis and Diabetes

The liver produces endogenous glucose to support life during fasting. Counterregulatory hormones, including glucagon, catecholamines, and glucocorticoids, stimulate the expression of gluconeogenic enzymes in the liver, thus driving liver glucose production. In contrast, insulin suppresses hepatic gluconeogenesis, thereby restraining postprandial glucose levels. Hepatic gluconeogenesis aberrantly increases in type 2 diabetes due to an imbalance between insulin and counterregulatory hormone actions, contributing to hyperglycemia and glucose intolerance. N6-methyladenosine (m6A) RNA methylation has emerged as a critical paradigm shaping cell identities and functions. The Mettl3/Mettl14 complex catalyzes m6A on RNA and RNA-binding proteins bind to the m6A motifs and determine the fate of client mRNAs (splicing, trafficking, stability, and/or translation) . However, m6A RNA modification has not been explored in liver gluconeogenesis. Here, we identified Mettl14 as an important positive regulator of hepatic gluconeogenesis. Liver Mettl14 levels were increased in db/db mice and mice with high fat diet (HFD) -induced obesity. Hepatocyte-specific deletion of Mettl14 decreased hepatic glucose production and ameliorated HFD-induced glucose intolerance; conversely, liver-specific overexpression of Mettl14 increased liver glucose production and HFD-induced glucose intolerance. Of note, Mettl14 did not alter liver insulin actions under our experimental conditions. Remarkably, hepatic deficiency of Mettl14 profoundly blunted the ability of glucagon to stimulate gluconeogenesis in mice. Consistently, deletion of Mettl14 largely blocked glucagon-stimulated gluconeogenesis ex vivo in liver slices as well as in primary hepatocyte cultures. In contrast, overexpression of Mettl14 had the opposite effects. Collectively, these data unravel a previously unrecognized glucagon/Mettl14/gluconeogenesis axis that is involved in hyperglycemia and glucose intolerance in diabetes. Disclosure Q. Zheng: None. X. Zhong: None. D. Ren: None. L. Rui: None. Funding National Institutes of Health (RO1DK127568) , American Heart Association (831585)

217-LB: Hepatic Mig6 Ablation Restores Glucose Homeostasis during Diet-Induced Obesity and Aging

Hepatic epidermal growth factor receptor (EGFR) expression and activation are decreased during steatosis in humans and animal models of obesity. Restoring EGFR activation in obesity-induced endoplasmic reticulum (ER) stress and diabetes is a potential therapy to improve liver function and metabolism in type 2 diabetes (T2D) . Mitogen-inducible gene 6 (Mig6) is an inducible feedback inhibitor of EGFR activity; we previously observed that liver Mig6 expression was increased during obesity-induced insulin resistance in mice and by both pharmacological- and fatty acid-driven ER stress in hepatocytes, leading to decreased EGF-mediated EGFR activation. To test Mig6 as a potential target to treat insulin resistance in T2D, we examined liver-specific Mig6 knockout mice (LKO) and their littermate controls (CON) . LKO mice exhibited reduced liver fat content and normalized glycogen storage with diet-induced obesity. In addition, we observed enhanced hepatic insulin action and whole-body glucose tolerance, due to increased hepatic glucose uptake, as determined by hyperinsulinemic-euglycemic clamps. Using whole transcriptome sequencing, peroxisomal and mitochondrial beta-oxidation genes were decreased by Mig6 ablation, correlating with a compromised gene expression of liver gluconeogenic enzymes. Moreover, analysis of mice aged for one year, a different physiological insult causing insulin resistance and liver oxidative stress, we were able to recapitulate the main findings as with diet-induced obesity: decreased gluconeogenesis, enhanced liver glucose uptake leading to increased glucose tolerance. Moreover, in aged LKO mice, liver oxidative stress markers were reduced. In conclusion, we postulate that hepatic Mig6 deficiency partially reverts the effects of diabetes by decreasing hepatic glucose output and reducing cellular oxidative stress, thereby establishing Mig6 as a therapeutic candidate for treating insulin resistance in obesity and T2D. Disclosure J. M. Irimia-dominguez: None. E. A. Bloom-saldana: None. P. T. Fueger: Consultant; Protomer Technologies.

Effect of SLC16A1 on Hepatic Glucose Metabolism in Newborn and Post-Weaned Holstein Bulls.

Background: Patterns of liver energy metabolism significantly differ from birth to adult in cattle undergoing change of rumen rumination. However, the genes involve in hepatic energy metabolism during bovine development and how regulate are still unclear. Methods: In this study, 0-day-old newborn calves (0W) and 9-week-old weaned calves (9W) were used to investigate differences in liver glucose metabolism at these stages of calf development. We did this primarily through the quantitation of energy metabolism indicators, then sequencing the liver transcriptome for each group of claves. Results: The transcriptome results showed 979 differentially expressed genes (DEGs), enriched in animal organ development, catabolic process, transmembrane transport. SLC16A1 involved in that and was locked to investigate. We explored the effects of SLC16A1 on glucose and lactate flux in vitro. We identified and verified its target, miR-22-3p, through bioinformatics and luciferase reporter assays. Moreover, this study found that miR-22-3p decreased cell activity by negatively regulating the SLC16A1. Importantly, our result showed the insulin-induced SLC16A1 mRNA expression decreased, regulated by promoter activity rather than miR-22-3p. Conclusions: Our study illustrates the role of SLC16A1 in the liver mediated metabolism of developing calves. These data enrich our knowledge of the regulatory mechanisms of liver mediated glucose metabolism in developing cattle.

A randomized controlled trial for response of microbiome network to exercise and diet intervention in patients with nonalcoholic fatty liver disease

Exercise and diet are treatments for nonalcoholic fatty liver disease (NAFLD) and prediabetes, however, how exercise and diet interventions impact gut microbiota in patients is incompletely understood. We previously reported a 8.6-month, four-arm (Aerobic exercise, n = 29; Diet, n = 28; Aerobic exercise + Diet, n = 29; No intervention, n = 29) randomized, singe blinded (for researchers), and controlled intervention in patients with NAFLD and prediabetes to assess the effect of interventions on the primary outcomes of liver fat content and glucose metabolism. Here we report the third primary outcome of the trial—gut microbiota composition—in participants who completed the trial (22 in Aerobic exercise, 22 in Diet, 23 in Aerobic exercise + Diet, 18 in No Intervention). We show that combined aerobic exercise and diet intervention are associated with diversified and stabilized keystone taxa, while exercise and diet interventions alone increase network connectivity and robustness between taxa. No adverse effects were observed with the interventions. In addition, in exploratory ad-hoc analyses we find that not all subjects responded to the intervention in a similar manner, when using differentially altered gut microbe amplicon sequence variants abundance to classify the responders and low/non-responders. A personalized gut microbial network at baseline could predict the individual responses in liver fat to exercise intervention. Our findings suggest an avenue for developing personalized intervention strategies for treatment of NAFLD based on host-gut microbiome ecosystem interactions, however, future studies with large sample size are needed to validate these discoveries. The Trial Registration Number is ISRCTN 42622771.

Prejuveniles of Mugil liza (Actinopterygii; Fam. Mugilidae) show digestive and metabolic flexibility upon different postprandial times and refeeding.

Many animals face periods of feeding restrictions implying fasting and refeeding. The determination of digestive/metabolic and body condition parameters at different times of food deprivation and after refeeding allows to evaluate the postprandial dynamics, the transition from feeding to fasting and the capacity to reverse digestive and metabolic alterations. In spite of its physiological importance, studies on estuarine-dependent detritivore fish are lacking. We determined total mass (TM), relative intestine length (RIL), hepatosomatic index (HSI), digestive enzymes activities in the intestine and energy reserves in liver and muscle at 0, 24, 72, 144 and 240h after feeding and at 72h after refeeding in prejuveniles of Mugil liza (Mugilidae) as a model species. After feeding, a decrease occurred in: TM (144h, 25%), RIL (144h, 23%); amylase and maltase (72h, 45 and 35%), sucrase (24h, 40%) and lipase (24h, 70%) in intestine; glycogen and free glucose (72h, 90 and 92%) in liver. In muscle, glycogen (72-144h) and free glucose (144h) (170% and 165%, respectively) peak increased; triglycerides decreased at 24-240h (50%). After refeeding TM, RIL, carbohydrases activities in intestine, glycogen and free glucose in liver were recovered. In muscle, glycogen and free glucose were similar to 0h; lipase activity and triglycerides were not recovered. Trypsin and APN in intestine, triglycerides in liver, protein in liver and muscle and HSI did not change. The differential modulation of key components of carbohydrates and lipid metabolism after feeding/refeeding would allow to face fasting and recover body condition. Our results improve lacking knowledge about digestive and metabolic physiology of detritivore fish.

Identification of novel indole derivatives as highly potent AMPK activators with anti-diabetic profiles

AMP-activated protein kinase (AMPK) has been shown to play an important role in the beneficial effects of exercise on glucose and lipid metabolism in skeletal muscle and liver. Therefore, activation of AMPK has been proposed as an attractive strategy for the treatment of metabolic disorders, such as type 2 diabetes. Many of existing AMPK activators bearing diverse chemical structure were reported. However, there have been few reports of direct AMPK activator with high potency for β2-AMPK isoform, which is thought to be important for glucose homeostasis, and their chemical structure is limited to benzimidazole core. We describe herein our efforts for identification of novel AMPK activator. Our newly designed 4-azaindole derivative 16g exhibited single-digit nM in vitro activity, and chronic treatment with 16g led to dose-dependent improvement in HbA1c as well as decrease in hepatic lipid accumulation in diabetic animal model.

Upregulation of the serine palmitoyltransferase subunit SPTLC2 by endoplasmic reticulum stress inhibits the hepatic insulin response

Endoplasmic reticulum (ER) stress is induced by various conditions, such as inflammation and the presence of excess nutrients. Abnormal accumulation of unfolded proteins leads to the activation of a collective signaling cascade, termed the unfolded protein response (UPR). ER stress is reported to perturb hepatic insulin response metabolism while promoting insulin resistance. Here, we report that ER stress regulates the de novo biosynthesis of sphingolipids via the activation of serine palmitoyltransferase (SPT), a rate-limiting enzyme involved in the de novo biosynthesis of ceramides. We found that the expression levels of Sptlc1 and Sptlc2, the major SPT subunits, were upregulated and that the cellular concentrations of ceramide and dihydroceramide were elevated by acute ER stress inducers in primary hepatocytes and HepG2 cells. Sptlc2 was upregulated and ceramide levels were elevated by tunicamycin in the livers of C57BL/6J wild-type mice. Analysis of the Sptlc2 promoter demonstrated that the transcriptional activation of Sptlc2 was mediated by the spliced form of X-box binding protein 1 (sXBP1). Liver-specific Sptlc2 transgenic mice exhibited increased ceramide levels in the liver and elevated fasting glucose levels. The insulin response was reduced by the inhibition of the phosphorylation of insulin receptor β (IRβ). Collectively, these results demonstrate that ER stress induces activation of the de novo biosynthesis of ceramide and contributes to the progression of hepatic insulin resistance via the reduced phosphorylation of IRβ in hepatocytes.

Sucrose-free hawthorn leathers formulated with fructooligosaccharides and xylooligosaccharides ameliorate high-fat diet induced inflammation, glucose and lipid metabolism in liver of mice

High sucrose content in traditional hawthorn leathers limits the potential consumption, particularly for elders and diabetics. In this study, sucrose-free hawthorn leathers were formulated with 75% fructooligosaccharides (FOS) and 25% xylooligosaccharides (XOS) (HLF75), which exhibited comparable morphology and sensory properties to the traditional ones. Then, the anti-obesity activity of HLF75 was investigated using high-fat diet (HFD) fed C57BL/6J mice. Comparing with traditional hawthorn leathers, HLF75 supplementation in HFD significantly decreased the levels of blood glucose and serum lipid. The histomorphologies of liver and subcutaneous fat tissues were ameliorated by HLF75, as well as the down-regulated mRNA expression levels of IL-1β, Nos2 and Cox-2 in the liver. Moreover, the protein levels of MyD88 and NF-κB in the liver were suppressed by HLF75 treatment with decreased F4/80-positive macrophage number. However, the expression levels of PI3K, phosphorylated-AKT (Thr308), and phosphorylated-mTOR (Ser2448) proteins related to glucose metabolism were increased in the liver. Moreover, fat synthesis-related gene expression in HLF75-fed mice was suppressed while expressions of lipolysis genes were improved. Thus, HLF75 supplementation alleviated HFD-induced obesity through the alleviation of inflammation and restoration of the disturbed glucose and lipid metabolism. Functional oligosaccharides could be effective sucrose substitutes in hawthorn leathers and enable their potential utilization as functional foods.

Glycolysis and gluconeogenesis are involved of glucose metabolism adaptation during fasting and re-feeding in black carp (Mylopharyngodon piceus)

Both in nature and in aquaculture, fish may experience periods of food scarcity or hunger. The metabolic regulation of fish when nutritional state changes is a complex process that involves many factors. To study glucose metabolism adaptability during fasting and re-feeding in the black carp (Mylopharyngodon piceus), we measured changes in some biochemical indicators related to glucose metabolism. Five fish were sampled on days 0, 1, 3, 5, and 10 of fasting (F, S1, S3, S5, and S10, respectively) and days 1, 3, and 5 of re-feeding (RF1, RF3, and RF5, respectively). The serum glucose concentration decreased significantly at S1, reached the lowest point at S10, and increased significantly at RF1 (P < 0.05). The concentration of liver glycogen decreased significantly at S1 and reached the lowest level at S3, whereas the muscle glycogen level decreased significantly at S5 and reached the lowest value at S10 (P < 0.05). Both liver and muscle glycogen levels returned to the pre-fasting level at RF5 (P < 0.05). Regarding glycolysis, the concentrations of pyruvate kinase (PK) and hexokinase (HK) decreased significantly at S5 and increased significantly at RF5 and RF1, respectively (P < 0.05). The concentrations of glucokinase (GCK) and insulin decreased significantly at S1 and increased significantly at RF1 and RF3, respectively (P < 0.05). The mRNA expression levels of liver GCK and glucose transporter 2 (GLUT2) decreased significantly at S1 and increased significantly at RF1 and RF5, respectively (P < 0.05). As for gluconeogenesis, the concentration of glucose-6-phosphatase (G6PC) increased significantly at S1 and decreased significantly at RF1 (P < 0.05). The concentrations of glucagon and glucocorticoid (GC) increased significantly at S3 and significantly decreased at RF1 and RF5, respectively (P < 0.05). The mRNA expression levels of liver G6PC and phosphoenolpyruvate carboxykinase (PEPCK) increased significantly at S3 and S1, and both decreased significantly at RF1 (P < 0.05). These results indicate that coordination between glycolysis and gluconeogenesis might be crucial for glucose homeostasis during fasting and re-feeding in the black carp.

Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter.

Grey mouse lemurs (Microcebus murinus) are primates that respond to environmental energetic constraints through strong physiological seasonality. They notably fatten during early winter (EW), and mobilize their lipid reserves while developing glucose intolerance during late winter (LW), when food availability is low. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, whose seasonal regulations are comparable to their wild counterparts. We highlight profound hepatic changes that reflect fat accretion in EW at the whole-body level, without triggering an ectopic storage of fat in the liver, however. Moreover, molecular regulations are consistent with the decrease in liver glucose utilization in LW, and therefore with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways. Fat mobilization in LW appeared possibly linked to the reactivation of the reproductive system while enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Overall, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while opposing the development of a pathological state despite large lipid fluxes.

Biological variation in clozapine and metabolite reporting during therapeutic drug monitoring

BackgroundClozapine (CLO) is an atypical antipsychotic used in management of treatment-resistant schizophrenia. Adverse drug reactions are caused by both CLO and its primary metabolite, norclozapine (NCLO). We defined the biological variability of CLO, NCLO, and the CLO to NCLO ratio (CNR) as well as assess the impact of reporting CLO and NCLO routinely. MethodsThe CVi and CVg were calculated from 1904 results from 247 patients by CV-ANOVA, and ANOVA, respectively, for CLO, NCLO, and the CNR. Association between each were also analyzed against a number of parameters including age and gender, complete blood count (CBC), kidney and liver function tests, lipids, and glucose within 24 h of CLO measurement. ResultsFor CLO, NCLO and CNR, the CVi was calculated as 19.3%, 19.2%, and 14.7%, and the CVg was 46.9%, 51.4%, and 36.3%, respectively. A total of 87 patients (19.7%) demonstrated higher NCLO results than CLO, with a ratio as low as 0.47. Kidney function was also found to have a statistically significant relationship to CLO and NCLO levels. ConclusionsWe provide data for biological variability of CLO metabolism as well as while providing some evidence for reporting NCLO values clinically.

Anti-obesity, slimming, biochemical and genotoxic effects of Cordia ecalyculata in diet-induced obese rats.

Overweight and obesity are associated with deaths and diseases worldwide. Cordia ecalyculata is a plant marketed as a slimmer. The study evaluated the anti-obesity effects of the dry extract from C. ecalyculata in rats fed with a standard diet (STD) or cafeteria diet (CD) receiving the dry extract from C. ecalyculata at 500, 1000, and 2000 mg/kg for 40 days. Furthermore, it evaluated the slimming effect on diet-induced obese rats by the treatment with the same doses for 30 days. The bodyweight of the rats, as well as the intake of food, was measured. Blood samples were collected to determine the liver function (albumin, alanine transaminase (ALT), alkaline phosphatase (ALP), glucose), renal function (urea and creatinine), and lipid profile (cholesterol, triglycerides). The genotoxic effect in peripheral blood was assessed through the comet assay. A lower C. ecalyculata dose significantly prevented the weight gain in rats fed with STD and CD and decreased body weight and intake food of obese rats. The biochemical parameters were not altered, except to increase the serum albumin. Only the higher dose induced DNA damage when evaluated in rats fed with CD in the slimming evaluation model used. These results reinforce the extract as an anti-obesity and slimming supplement.

Transcriptome Analysis of Liver Cancer Cell Huh-7 Treated With Metformin.

Metformin is a kind of widely used antidiabetic drug that regulates glucose homeostasis by inhibiting liver glucose production and increasing muscle glucose uptake. Recently, some studies showed that metformin exhibits anticancer properties in a variety of cancers. Although several antitumor mechanisms have been proposed for metformin action, its mode of action in human liver cancer remains not elucidated. In our study, we investigated the underlying molecular mechanisms of metformin's antitumor effect on Huh-7 cells of hepatocellular carcinoma (HCC) in vitro. RNA sequencing was performed to explore the effect of metformin on the transcriptome of Huh-7 cells. The results revealed that 4,518 genes (with log2 fold change > 1 or < −1, adjusted p-value < 0.05) were differentially expressed in Huh-7 cells with treatment of 25-mM metformin compared with 0-mM metformin, including 1,812 upregulated and 2,706 downregulated genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses identified 54 classical pathways that were significantly enriched, and 16 pathways are closely associated with cancer, such as cell cycle, DNA replication, extracellular matrix–receptor interaction, and so on. We selected 11 differentially expressed genes, which are closely associated with HCC, to validate their differential expressions through a quantitative real-time reverse transcription-polymerase chain reaction. The result exhibited that the genes of fatty acid synthase, mini-chromosome maintenance complex components 6 and 5, myristoylated alanine-rich C-kinase substrate, fatty acid desaturase 2, C-X-C motif chemokine ligand 1, bone morphogenetic protein 4, S-phase kinase-associated protein 2, kininogen 1, and proliferating cell nuclear antigen were downregulated, and Dual-specificity phosphatase-1 is significantly upregulated in Huh-7 cells with treatment of 25-mM metformin. These differentially expressed genes and pathways might play a crucial part in the antitumor effect of metformin and might be potential targets of metformin treating HCC. Further investigations are required to evaluate the metformin mechanisms of anticancer action in vivo.

Disrupting AMPK-Glycogen Binding in Mice Increases Carbohydrate Utilization and Reduces Exercise Capacity.

The AMP-activated protein kinase (AMPK) is a central regulator of cellular energy balance and metabolism and binds glycogen, the primary storage form of glucose in liver and skeletal muscle. The effects of disrupting whole-body AMPK-glycogen interactions on exercise capacity and substrate utilization during exercise in vivo remain unknown. We used male whole-body AMPK double knock-in (DKI) mice with chronic disruption of AMPK-glycogen binding to determine the effects of DKI mutation on exercise capacity, patterns of whole-body substrate utilization, and tissue metabolism during exercise. Maximal treadmill running speed and whole-body energy utilization during submaximal running were determined in wild type (WT) and DKI mice. Liver and skeletal muscle glycogen and skeletal muscle AMPK α and β2 subunit content and signaling were assessed in rested and maximally exercised WT and DKI mice. Despite a reduced maximal running speed and exercise time, DKI mice utilized similar absolute amounts of liver and skeletal muscle glycogen compared to WT. DKI skeletal muscle displayed reduced AMPK α and β2 content versus WT, but intact relative AMPK phosphorylation and downstream signaling at rest and following exercise. During submaximal running, DKI mice displayed an increased respiratory exchange ratio, indicative of greater reliance on carbohydrate-based fuels. In summary, whole-body disruption of AMPK-glycogen interactions reduces maximal running capacity and skeletal muscle AMPK α and β2 content and is associated with increased skeletal muscle glycogen utilization. These findings highlight potential unappreciated roles for AMPK in regulating tissue glycogen dynamics and expand AMPK’s known roles in exercise and metabolism.