Circulating levels of microRNA-122 and hepatic fat change in response to weight-loss interventions: CENTRAL Trial

Purpose Little is known about the relations between changes in circulating microRNA-122 (miR-122) and liver fat in response to weight-loss interventions. We aimed to investigate the association between miR-122 and changes of hepatic fat content during 18-month diet and physical activity interventions. Methods The CENTRAL trial is an 18-month randomized, controlled trial among adults with abdominal obesity or dyslipidemia. Subjects were randomly assigned to a low-fat diet or a Mediterranean/low-carbohydrate diet. After six months of dietary intervention, each diet group was further randomized into added physical activity groups or no added physical activity groups for the following 12 months of intervention. The current study included 220 participants at baseline and 134 participants with repeated measurements on serum miR-122 and hepatic fat content over 18 months. Results Serum miR-122 significantly increased from baseline to 18 months, while no difference was observed across the four intervention groups. We found a significant association between miR-122 and hepatic fat content at baseline, as per unit increment in log-transformed miR-122 was associated with 3.79 higher hepatic fat content (P<0.001). Furthermore, we found that higher elevations in miR-122 were associated with less reductions in hepatic fat percentage during 18-month interventions (β=1.56, P=0.002). We also found a significant interaction between changes in miR-122 and baseline fasting plasma glucose with hepatic fat content changes in 18 months (P interaction=0.02). Conclusions Our data indicate that participants with higher elevation in serum miR-122 may benefit less in reduction of hepatic fat content in response to diet and physical activity interventions.

The relationship between Lipocalin-2 level and hepatic steatosis in obese patients with NAFLD after bariatric surgery

Background Lipocalin-2 (LCN2) has a critical effect on obesity as well as its associated comorbidities. The present study focused on analyzing serum LCN2 levels of obese patients with nonalcoholic fatty liver disease (NAFLD) and on determining relationship of hepatic steatosis improvement with LCN2 levels after laparoscopic sleeve gastrectomy (LSG). Methods This work enrolled ninety patients with obesity and NAFLD. Twenty-three of them underwent LSG. Anthropometric and biochemical parameters and serum LCN2 levels were determined at baseline and those at 6-month post-LSG. Controlled attenuation parameter (CAP) measured by FibroScan was adopted for evaluating hepatic steatosis. Results Among severe obesity patients, serum LCN2 levels were significantly increased (111.59 ± 51.16 ng/mL vs. 92.68 ± 32.68 ng/mL, P = 0.035). The CAP value was higher indicating higher liver fat content (360.51 ± 45.14 dB/m vs. 340.78 ± 45.02 dB/m, P = 0.044). With regard to surgical patients, liver function, glucose, and lipid levels were significantly improved after surgery. Serum LCN2 levels significantly decreased (119.74 ± 36.15 ng/mL vs. 87.38 ± 51.65 ng/mL, P = 0.001). Decreased CAP indicated a significant decrease in liver fat content (358.48 ± 46.13 dB/m vs. 260.83 ± 69.64 dB/m, P < 0.001). The decrease in LCN2 levels was significantly related to the reduced hepatic fat content and improvement in steatosis grade after adjusting for gender, age, and BMI decrease. Conclusions Serum LCN2 levels are related to obesity and NAFLD. The decreased serum LCN2 levels could be an indicator of hepatic steatosis improvement.

Dietary Beta-Hydroxy-Beta-Methyl Butyrate Supplementation Inhibits Hepatic Fat Deposition via Regulating Gut Microbiota in Broiler Chickens

The present study is aimed to explore the effects of different dietary beta-hydroxy-beta-methyl butyrate (HMB) levels (0, 0.05%, 0.10%, or 0.15%) on liver lipid metabolism on Wenshi broiler chickens. Results showed that HMB reduced the liver weight as well as liver concentrations of triacylglycerol (TG) and total cholesterol (TC) (quadratically, p < 0.05), and the lowest values were observed in the 0.10% HMB group. Meanwhile, HMB supplementation significantly altered the expression levels of key genes related to lipid metabolism in the liver of broiler chickens (p < 0.05). Furthermore, 16S rRNA gene sequencing revealed that HMB supplementation could greatly change the richness, diversity, and composition of the broiler gut microbiota, and the Bacteroidetes relative abundance at the phylum level and the Alistipes relative abundance at the genus level were affected (p < 0.05). Correlation analysis further suggested a strong association between Bacteroidetes relative abundance and lipid metabolism-related parameters (p < 0.05). Together, these data suggest that 0.10% HMB supplementation could inhibit hepatic fat deposition via regulating gut microbiota in broilers.

Noninvasive estimation of local speed of sound by pulse-echo ultrasound in a rat model of nonalcoholic fatty liver

Objective: Speed of sound has previously been demonstrated to correlate with fat concentration in the liver. However, estimating speed of sound in the liver noninvasively can be biased by the speed of sound of the tissue layers overlying the liver. Here, we demonstrate a noninvasive local speed of sound estimator, which is based on a layered media assumption, that can accurately capture the speed of sound in the liver. We validate the estimator using an obese Zucker rat model of non-alcoholic fatty liver disease and correlate the local speed of sound with liver steatosis. Approach: We estimated the local and global average speed of sound noninvasively in 4 lean Zucker rats fed a normal diet and 16 obese Zucker rats fed a high fat diet for up to 8 weeks. The ground truth speed of sound and fat concentration were measured from the excised liver using established techniques. Main Results: The noninvasive, local speed of sound estimates of the livers were similar in value to their corresponding "ground truth'' measurements, having a slope ± standard error of the regression of 0.82 ± 0.15 (R2 = 0.74 and p < 0.001). Measurement of the noninvasive global average speed of sound did not reliably capture the ``ground truth'' speed of sound in the liver, having a slope of 0.35 ± 0.07 (R2 = 0.74 and p < 0.001). Decreasing local speed of sound was observed with increasing hepatic fat accumulation (approximately -1.7 m/s per 1% increase in hepatic fat) and histopathology steatosis grading (approximately -10 to -13 m/s per unit increase in steatosis grade). Local speed of sound estimates were highly correlated with steatosis grade, having Pearson and Spearman correlation coefficients both ranging from -0.87 to -0.78. In addition, a lobe-dependent speed of sound in the liver was observed by the ex vivo measurements, with speed of sound differences of up to 25 m/s (p < 0.003) observed between lobes in the liver of the same animal. Significance: The findings of this study suggest that local speed of sound estimation has the potential to be used to predict or assist in the measurement of hepatic fat concentration and that the global average speed of sound should be avoided in hepatic fat estimation due to significant bias in the speed of sound estimate.

Chrysanthemum morifolium Flower Extract Ameliorates Obesity-Induced Inflammation and Increases the Muscle Mitochondria Content and AMPK/SIRT1 Activities in Obese Rats

Decreased energy expenditure and chronically positive energy balance contribute to the prevalence of obesity and associated metabolic dysfunctions, such as dyslipidemia, hepatic fat accumulation, inflammation, and muscle mitochondrial defects. We investigated the effects of Chrysanthemum morifolium Ramat flower extract (CE) on obesity-induced inflammation and muscle mitochondria changes. Sprague–Dawley rats were randomly divided into four groups and fed either a normal diet, 45% high-fat diet (HF), HF containing 0.2% CE, or 0.4% CE for 13 weeks. CE alleviated HF-increased adipose tissue mass and size, dyslipidemia, hepatic fat deposition, and systematic inflammation, and increased energy expenditure. CE significantly decreased gene expression involved in adipogenesis, pro-inflammation, and the M1 macrophage phenotype, as well as glycerol-3-phosphate dehydrogenase (GPDH) and nuclear factor-kappa B (NF-kB) activities in epididymal adipose tissue. Moreover, CE supplementation improved hepatic fat accumulation and modulated gene expression related to fat synthesis and oxidation with an increase in adenosine monophosphate-activated protein kinase (AMPK) activity in the liver. Furthermore, CE increased muscle mitochondrial size, mitochondrial DNA (mtDNA) content, and gene expression related to mitochondrial biogenesis and function, including sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), and PGC-1α-target genes, along with AMPK-SIRT1 activities in the skeletal muscle. These results suggest that CE attenuates obesity-associated inflammation by modulating the muscle AMPK-SIRT1 pathway.

Advances in Unhealthy Nutrition and Circadian Dysregulation in Pathophysiology of NAFLD

Unhealthy diets and lifestyle result in various metabolic conditions including metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Much evidence indicates that disruption of circadian rhythms contributes to the development and progression of excessive hepatic fat deposition and inflammation, as well as liver fibrosis, a key characteristic of non-steatohepatitis (NASH) or the advanced form of NAFLD. In this review, we emphasize the importance of nutrition as a critical factor in the regulation of circadian clock in the liver. We also focus on the roles of the rhythms of nutrient intake and the composition of diets in the regulation of circadian clocks in the context of controlling hepatic glucose and fat metabolism. We then summarize the effects of unhealthy nutrition and circadian dysregulation on the development of hepatic steatosis and inflammation. A better understanding of how the interplay among nutrition, circadian rhythms, and dysregulated metabolism result in hepatic steatosis and inflammation can help develop improved preventive and/or therapeutic strategies for managing NAFLD.

Safety, Tolerability, and Pharmacokinetics of a Novel Mitochondrial Modulator, TRC150094, in Overweight and Obese Subjects: A Randomized Phase-I Clinical Trial

TRC150094, a novel mitochondrial modulator, can restore metabolic flexibility by improving insulin resistance in preclinical studies. This study primarily aims to evaluate the safety, tolerability, and pharmacokinetics (PK) of oral TRC150094 after conducting two double-blind, randomized, Phase-I studies, single ascending dose (SAD) and multiple ascending dose (MAD), with n = 46, in overweight/obese adult and elderly subjects. In addition, the effect of TRC150094 on pharmacodynamic (PD) efficacy markers was evaluated. PK assessments, including maximum concentration (Cmax), area under the plasma concentration (AUC), time to Cmax (Tmax), and elimination half-life (t½), were assessed at pre-specified time points. PD assessments included apolipoprotein B (ApoB), triglycerides, hepatic fat by magnetic resonance spectroscopy (MRS) and cardiopulmonary exercise testing (CPET) parameters. TRC150094 was rapidly absorbed, and the AUC of TRC150094 increased in a dose-dependent manner across all doses in non-elderly and elderly cohorts. Cmax was more than the dose-proportional for all doses in all cohorts. Tmax ranged from 0.25 to 4 h, and t½ ranged from 15 to 18 h, making TRC150094 suitable for once-daily dosing. Food did not interfere with the overall absorption of the drug. The metabolites of TRC150094 were glucuronide and sulfate conjugates, and 20% of the drug was excreted unchanged in the urine. TRC150094 at 50 mg showed an improving trend in triglycerides. A significant reduction in Apo B was observed after 50 mg dose (−2.34 vs. 13.24%, p = 0.008), which was, however, not the case after 150 mg (8.78 vs. 13.24%, p = 0.1221). Other parameters such as hepatic fat and insulin sensitivity indices (HOMA-IR, MATSUDA Index derived from OGTT) showed an improving trend for the dose of 50 mg. In terms of safety, all the AEs reported were mild to moderate in severity. None of the adverse events was considered definitely or probably related to treatment, and there were no abnormal laboratory findings. In conclusion, the PK of TRC150094 was linear with no clinically significant food effect. TRC150094 and its metabolites suggest a lesser likelihood of drug-drug interactions. Overall, TRC150094 ensured safety and exhibited suitability for all subjects.Clinical Trial Registration: EUDRA CT: 2009-014941-10 (SAD) and CTR-India registration: CTRI/2009/091/000601 (MAD)

Lipid Profile and Hepatic Fat Content Measured by 1H MR Spectroscopy in Patients before and after Liver Transplantation

Increased hepatic fat content (HFC) is a hallmark of non-alcoholic fatty liver (NAFL) disease, a common condition in liver transplant recipients. Proton MR spectroscopy (1H MRS) and MR imaging-based proton density fat fraction as the only diagnosis modality enable precise non-invasive measurement of HFC and, also, fatty acid profiles in vivo. Using 1H MRS at 3T, we examined 47 liver transplantation candidates and 101 liver graft recipients. A point-resolved spectroscopy sequence was used to calculate the steatosis grade along with the saturated, unsaturated and polyunsaturated fractions of fatty acids in the liver. The steatosis grade measured by MRS was compared with the histological steatosis grade. HFC, represented by fat fraction values, is adept at distinguishing non-alcoholic steatohepatitis (NASH), NAFL and non-steatotic liver transplant patients. Relative hepatic lipid saturation increases while unsaturation decreases in response to increased HFC. Additionally, relative hepatic lipid saturation increases while unsaturation and polyunsaturation both decrease in liver recipients with histologically proven post-transplant NASH or NAFL compared to non-steatotic patients. HFC, measured by in vivo 1H MRS, correlated well with histological results. 1H MRS is a simple and fast method for in vivo analysis of HFC and its composition. It provides non-invasive support for NAFL and NASH diagnoses.