Prolactin improves hepatic steatosis via CD36 pathway

BACKGROUND & AIMS

Prolactin (PRL) is a multifunctional polypeptide with effects on metabolism, however, little is known about its effect on hepatic steatosis and lipid metabolism. Herein, we aimed to assess the role of PRL in the development of non-alcoholic fatty liver disease (NAFLD).

METHODS

The serum PRL levels of 456 patients with NAFLD, 403 controls without NAFLD diagnosed by ultrasound, and 85 individuals with liver histology obtained during metabolic surgery (44 female and 30 male patients with NAFLD and 11 age-matched non-NAFLD female individuals) were evaluated. The expression of the gene encoding the prolactin receptor (PRLR) and signalling molecules involved in hepatic lipid metabolism were evaluated in human liver and HepG2 cells. The effects of overexpression of PRLR or fatty acid translocase (FAT)/CD36 or knockdown of PRLR on hepatic lipid metabolism were tested in free fatty acid (FFA)-treated HepG2 cells.

RESULTS

Circulating PRL levels were lower in individuals with ultrasound-diagnosed NAFLD (men: 7.9 [range, 5.9-10.3] µg/L; women: 8.7 [range, 6.1-12.4] µg/L) than those with non-NAFLD (men: 9.1 [range, 6.8-13.0] µg/L, p = 0.002; women: 11.6 [range, 8.2-16.1] µg/L, p <0.001). PRL levels in patients with biopsy-proven severe hepatic steatosis were lower compared with those with mild-to-moderate hepatic steatosis in both men (8.3 [range, 5.4-9.5] µg/L vs. 9.7 [range, 7.1-12.3] µg/L, p = 0.031) and women (8.5 [range, 4.2-10.6] µg/L vs. 9.8 [range, 8.2-15.7] µg/L, p = 0.027). Furthermore, hepatic PRLR gene expression was significantly reduced in patients with NAFLD and negatively correlated with CD36 gene expression. In FFA-induced HepG2 cells, PRL treatment or PRLR overexpression significantly reduced the expression of CD36 and lipid content, effects that were abrogated after silencing of PRLR. Furthermore, overexpression of CD36 significantly reduced the PRL-mediated improvement in lipid content.

CONCLUSIONS

Our results reveal a novel association between the central nervous system and the liver, whereby PRL/PRLR improved hepatic lipid accumulation via the CD36 pathway.

LAY SUMMARY

Our clinical study suggests a negative association between prolactin (PRL)/prolactin receptor (PRLR) and the presence of non-alcoholic fatty liver disease (NAFLD). Using cell experiments, we found that PRL ameliorates hepatic steatosis via the hepatic PRLR and fatty acid translocase (FAT)/CD36, a key transporter of free fatty acid uptake in liver. Our findings suggest a novel approach to improving NAFLD using PRL and PRLR. Clinical trial number: NCT03296605.

Comparison of Glycemic Variability in Chinese T2DM Patients Treated with Exenatide or Insulin Glargine: A Randomized Controlled Trial

INTRODUCTION

Increasing the frequency of blood glucose monitoring aids the evaluation of glycemic variability and blood glucose control by antidiabetic drugs. It remains unclear, however, whether GLP-1 receptor agonists or basal insulin has a better effect on glycemic variability in type 2 diabetes mellitus (T2DM) patients who are inadequately controlled by metformin. We used a continuous glucose monitoring system (CGMS) to compare patients on a GLP-1 receptor agonist with patients on basal insulin in terms of glycemic variability.

METHODS

This prospective randomized study assigned T2DM patients treated with metformin (N = 39) to either exenatide treatment or insulin glargine treatment for 16 weeks. Glycemic variability was assessed using a CGMS; hemoglobin A1c (HbA1c), β-cell function, weight, body mass index (BMI), and waist circumference were also evaluated.

RESULTS

Mean blood glucose level, continuous overlapping net glycemic action, mean amplitude of glycemic excursions, percentage of the time that the blood glucose value was > 10.0 mmol/L, and highest blood glucose level (P  < 0.01-0.05) significantly decreased in both groups. Standard deviation of the mean glucose value, largest amplitude of glycemic excursions, and waist circumference significantly decreased for those treated with exenatide (P  < 0.05), while no changes were observed with insulin glargine treatment. Percentage of the time that the blood glucose value was > 7.8 mmol/L decreased after insulin glargine use (P  < 0.05) but not with the exenatide intervention. Similar decreases in fasting blood glucose and HbA1c and increases in the 1/homeostasis model assessment of insulin resistance, disposition index 30, and disposition index 120 were observed in both groups (P  < 0.01-0.05). Reductions in weight and BMI were greater with exenatide than with insulin glargine treatment (P  < 0.05).

CONCLUSIONS

In overweight and obese patients with T2DM inadequately controlled by metformin, exenatide and insulin glargine have similar efficacies in terms of glycemic variability, HbA1c alleviation, and β-cell function, but exenatide has a greater effect on body weight and BMI.

Altered Odor-Induced Brain Activity as an Early Manifestation of Cognitive Decline in Patients With Type 2 Diabetes

Type 2 diabetes is reported to be associated with olfactory dysfunction and cognitive decline. However, whether and how olfactory neural circuit abnormalities involve cognitive impairment in diabetes remains uncovered. This study thus aimed to investigate olfactory network alterations and the associations of odor-induced brain activity with cognitive and metabolic parameters in type 2 diabetes. Participants with normal cognition, including 51 patients with type 2 diabetes and 41 control subjects without diabetes, underwent detailed cognitive assessment, olfactory behavior tests, and odor-induced functional MRI measurements. Olfactory brain regions showing significantly different activation between the two groups were selected for functional connectivity analysis. Compared with the control subjects, patients with diabetes demonstrated significantly lower olfactory threshold score, decreased brain activation, and disrupted functional connectivity in the olfactory network. Positive associations of the disrupted functional connectivity with decreased neuropsychology test scores and reduced pancreatic function were observed in patients with diabetes. Notably, the association between pancreatic function and executive function was mediated by olfactory behavior and olfactory functional connectivity. Our results suggested the alteration of olfactory network is present before clinically measurable cognitive decrements in type 2 diabetes, bridging the gap between the central olfactory system and cognitive decline in diabetes.

Insulin Glargine Combined with Oral Antidiabetic Drugs for Asians with Type 2 Diabetes Mellitus: A Pooled Analysis to Identify Predictors of Dose and Treatment Response

INTRODUCTION

In Asia, patients with type 2 diabetes mellitus (T2DM) often have suboptimal glycemic control for many years prior to initiating basal insulin. Active titration of basal insulin is also required to improve glycemic outcomes. This pooled analysis was conducted to determine the impact of patient baseline covariates on the required dose of basal insulin and treatment response, for the improved management of Asian patients with T2DM.

METHODS

Data on insulin-naïve Asian patients with T2DM who initiated and fully titrated insulin glargine 100 U/mL (Gla-100) for ≥ 20 weeks were pooled from seven randomized, controlled, treat-to-target trials. Covariance and multivariate linear/logistic regression analyses were applied to determine the impact of the baseline covariates on Gla-100 dose (primary outcome) and treatment response (secondary outcomes) at week 24 for patients from Asia (N = 724) and from China alone (n = 249). Based on the multivariate analysis for the primary outcome in the Asian population, a nomogram was developed.

RESULTS

The dose of Gla-100 at week 24 was negatively correlated with age and positively correlated with body mass index (BMI) and fasting plasma glucose (FPG) at baseline in both Asian and Chinese populations. In both populations, higher baseline glycated hemoglobin (HbA_1c) was associated with a lower reduction in HbA_1c from baseline, higher HbA_1c at week 24, and a lower chance of achieving HbA_1c < 7% at week 24. The constructed nomogram enables calculation of the likely dose of Gla-100 required by Asian patients with T2DM to achieve HbA_1c < 7% at week 24.

CONCLUSIONS

Higher doses of Gla-100 are likely to be required in younger patients or patients with higher baseline BMI or FPG. The nomogram developed in this study can aid clinicians to titrate the dose of Gla-100 appropriately. Evidence in this pooled analysis also indicates that initiating basal insulin at a lower HbA_1c can lead to greater glycemic control.

FUNDING

Sanofi China Investment Company.

Erythropoietin alleviates hepatic steatosis by activating SIRT1-mediated autophagy

Erythropoietin (EPO), besides its stimulatory effect on erythropoiesis, is beneficial to insulin resistance and obesity. However, its role in hepatic steatosis remains unexplored. Activating autophagy seems a promising mechanism for improving fatty liver disease. The present study investigated the role of EPO in alleviating hepatic steatosis and sought to determine whether its function is mediated by the activation of autophagy. Here, we show that EPO decreased hepatic lipid content significantly in vivo and in vitro. Furthermore, EPO/EPO receptor (EPOR) signalling induced autophagy activation in hepatocytes as indicated by western blot assay, transmission electron microscopy, and confocal microscopy. In addition, EPO increased the co-localization of autophagosomes and cellular lipids as shown by double labelling of the autophagy marker light chain microtubule-associated protein 3 (LC3) and lipids. Importantly, suppression of autophagy by an inhibitor or small interfering RNA (siRNA) abolished the EPO-mediated alleviation hepatic steatosis in vitro. Furthermore, EPO up-regulated sirtuin 1 (SIRT1) expression, and siRNA-mediated SIRT1 silencing abrogated the EPO-induced increases in LC3 protein and deacetylation levels, thereby preventing the alleviation of hepatic steatosis. Taken together, this study revealed a new mechanism wherein EPO alleviates hepatic steatosis by activating autophagy via SIRT1-dependent deacetylation of LC3. This finding might have therapeutic value in the treatment of hepatic steatosis.

Unique molecular events during reprogramming of human somatic cells to induced pluripotent stem cells (iPSCs) at naïve state

Derivation of human naïve cells in the ground state of pluripotency provides promising avenues for developmental biology studies and therapeutic manipulations. However, the molecular mechanisms involved in the establishment and maintenance of human naïve pluripotency remain poorly understood. Using the human inducible reprogramming system together with the 5iLAF naïve induction strategy, integrative analysis of transcriptional and epigenetic dynamics across the transition from human fibroblasts to naïve iPSCs revealed ordered waves of gene network activation sharing signatures with those found during embryonic development from late embryogenesis to pre-implantation stages. More importantly, Transcriptional analysis showed a significant transient reactivation of transcripts with 8-cell-stage-like characteristics in the late stage of reprogramming, suggesting transient activation of gene network with human zygotic genome activation (ZGA)-like signatures during the establishment of naïve pluripotency. Together, Dissecting the naïve reprogramming dynamics by integrative analysis improves the understanding of the molecular features involved in the generation of naïve pluripotency directly from somatic cells.

[Status and related factors for gestational weight gain of Chinese pregnant women during 2010-2012]

Objective: To examine the status and related factors for gestational weight gain of Chinese pregnant women at different trimesters in 2010-2012. Methods: Participants were from Chinese National Nutrition and Health Surveillance in 2010-2012. Using a multi-stage stratified cluster random sampling method, we recruited 2 805 singleton pregnant women with gestational age 13 weeks or more from 31 provinces of China. A standard questionnaire was used to collect general information and pre-pregnancy weight; body weight and height of pregnant women were measured using a unified weighing scale and stadiometer, dietary intake during the previous year was collected using a food frequency questionnaire. A multiple logistic regression was used to analyze potential factors associated with appropriate gestational weight gain. Results: Among 2 805 pregnant women, 1 441 were in the second (13-27 weeks) and 1 364 in the third trimesters (≥28 weeks) . In the 2(nd) trimester, 229 cases (15.9%), 440 cases (30.5%) and 772 cases (53.6%) were insufficient gestational weight gain, appropriate gestational weight gain and excessive gestational weight gain respectively. So were 256 cases (18.8%), 474 cases (34.8%), 634 cases (46.5%) in the 3(rd) trimester respectively. In the multivariate unconditional logistic model, less fruit intake was associated with insufficient weight gain for women in the 2(nd) trimester (OR (95%CI): 1.58 (1.06-2.34)). Pregnant women with Han ethnicity who live in the small/medium city had lower risk of insufficient weight gain in the 3(rd) trimester (OR (95%CI): 0.58 (0.34-0.98)). Those pregnant women with physical activity <1 hour/day had a higher risk of excessive weight gain (OR (95%CI): 1.33 (1.02-1.73)). Conclusion: The prevalence of appropriate gestational weight gain was low in China. Our study suggests that pregnant weight gain is associated with fruit intake, types of residential area and physical activity.

[Prevalence of calf muscle cramps and influencing factors for pregnant women in China during 2010-2012]

Objective: To investigate the prevalence of calf muscle cramps and possible influencing factors for pregnant women in China. Methods: Using a multi-stage stratified probability proportional to size cluster randomization sampling method during 2010-2012. A total of 3 582 pregnant women were investigated at 150 counties from 31 provinces in China mainland. Information on calf muscle cramps, demographic socio-economic status, pregnancy information, and the physical activities was collected through questionnaires. The semi-quantitative food frequency questionnaire (FFQ) was used to collect food intake of pregnant women. Dynamic cluster analysis was used to assess dietary pattern. Multiple logistic regression was used to investigate the possible influencing factors for calf muscle cramps. Results: The prevalence of calf muscle cramps was 32.9% (1 180/3 582) in Chinese pregnant women, which was 11.6% (87/748), 28.2% (420/1 492), and 50.2% (673/1 342), respectively, during the first, second and third trimester. There were significant differences between them (χ(2)=349.16, P<0.001). Dietary patterns of the pregnant women were classified into three groups, which called relatively balanced pattern, high vegetables and fruits pattern, and high dairy pattern. Among the three groups, the prevalence of calf muscle cramps was 32.0% (952/2 971), 37.2% (186/500), and 37.8% (42/111), with significant differences (χ(2)=6.39, P=0.041). The OR (95%CI) values of calf muscle cramps in the second and third trimester was 2.96 (2.28-3.83), and 8.02 (6.16-10.44), respectively, comparing with the first trimester. The OR (95%CI) values of calf muscle cramps in the women taking calcium before pregnant was 1.45 (1.19-1.76), comparing with the one who was not taken. The OR (95%CI) values of calf muscle cramps in the women who had been diagnosed by pregnancy-induced hypertension was 5.76 (2.06-16.12), comparing with the one who had not been diagnosed. The OR (95%CI) values of calf muscle cramps in the high vegetables and fruits pattern and high dairy pattern was 1.13 (0.91-1.41), and 1.18 (0.76-1.81), respectively, comparing with the relatively balanced pattern. Conclusion: The prevalence of calf muscle cramps was relatively high in Chinese pregnant women, which was significantly different among three trimesters. The residential areas, occupation, and pregnancy-induced hypertension might be related to the prevalence of calf muscle cramps. However, there was no significant difference among different dietary patterns.

Oocyte-Specific Homeobox 1, Obox1, Facilitates Reprogramming by Promoting Mesenchymal-to-Epithelial Transition and Mitigating Cell Hyperproliferation

Mammalian oocytes possess fascinating unknown factors, which can reprogram terminally differentiated germ cells or somatic cells into totipotent embryos. Here, we demonstrate that oocyte-specific homeobox 1 (Obox1), an oocyte-specific factor, can markedly enhance the generation of induced pluripotent stem cells (iPSCs) from mouse fibroblasts in a proliferation-independent manner and can replace Sox2 to achieve pluripotency. Overexpression of Obox1 can greatly promote mesenchymal-to-epithelial transition (MET) at early stage of OSKM-induced reprogramming, and meanwhile, the hyperproliferation of THY1-positive cells can be significantly mitigated. Subsequently, the proportion of THY1-negative cells and Oct4-GFP-positive cells increased dramatically. Further analysis of gene expression and targets of Obox1 during reprogramming indicates that the expression of Obox1 can promote epithelial gene expression and modulate cell-cycle-related gene expression. Taken together, we conclude that the oocyte-specific factor Obox1 serves as a strong activator for somatic cell reprogramming through promoting the MET and mitigating cell hyperproliferation.

Levothyroxine monotherapy versus levothyroxine and selenium combination therapy in chronic lymphocytic thyroiditis

PURPOSE

New strategies are needed for prevention and treatment of chronic lymphocytic thyroiditis (CLT). This study aimed to assess whether combination of levothyroxine treatment and selenium (Se) supplementation results in improved therapeutic effects in CLT compared with levothyroxine monotherapy.

METHODS

An open-label, randomized controlled study was performed in 60 CLT patients assigned to two groups. Levothyroxine group (LT) patients (n = 24) received levothyroxine alone for 3 months; meanwhile, the combination (LTSS) group (n = 36) was administered levothyroxine with selenium yeast capsule. Blood selenium concentrations, anti-thyroid peroxidase (TPO) and anti-thyroglobulin (Tg) antibody levels, and inflammatory cytokine amounts were compared between both groups before and after treatment.

RESULTS

At baseline, similar values were obtained in both groups for all the parameters assessed (p > 0.05). After treatment, significantly increased blood selenium levels (µg/L) [90.05 (80.69, 107.76) vs. 39.64 (29.42, 51.10), p < 0.001] and decreased anti-TPO antibody (23.63 ± 9.31 vs. 32.00 ± 10.41%, p = 0.002), anti-Tg antibody (35.84 ± 15.21 vs. 45.47 ± 14.24%, p = 0.015) and IL-2 amounts (pg/mL) [159.29 (124.54, 189.70) vs. 226.48 (190.74, 266.56), p < 0.001] were observed in the LTSS group compared with the LT group post-treatment; meanwhile, similar IL-10 concentrations [23.14 (21.65, 28.56) pg/mL vs. 24.68 (21.71, 29.67) pg/mL] were obtained in both groups. Subgroup analysis of patients with hypothyroidism showed the same trend observed in the whole population; in patients with normal thyroid function, only Se and IL-2 amounts differed between the two treatment groups. Correlation analysis of of the indexes: in HT patients, the basal serum selenium concentration was positively correlated with TT₄ (r = 0.294, p < 0.05), significantly negatively correlated with TSH (r = -0.343, p < 0.01), and had no significant correlation with TT3 (p > 0.05).

CONCLUSIONS

These findings indicated that levothyroxine and selenium combination results in improved therapeutic effects than the levothyroxine monotherapy in preventing CLT progression.

Insulin restores UCP3 activity and decreases energy surfeit to alleviate lipotoxicity in skeletal muscle

An early insulin regimen ameliorates glucotoxicity but also lipotoxicity in type 2 diabetes; however, the underlying mechanism remains elusive. In the present study, we investigated the role of mitochondria in lipid regulation following early insulin administration in insulin-resistant skeletal muscle cells. Male C57BL/6 mice, fed a high-fat diet (HFD) for 8 weeks, were treated with insulin for 3 weeks, and L6 myotubes cultured with palmitate (PA) for 24 h were incubated with insulin for another 12 h. The results showed that insulin facilitated systemic glucose disposal and attenuated muscular triglyceride accumulation in vivo. Recovery of AMP-activated protein kinase (AMPK) phosphorylation, inhibition of sterol-regulated element binding protein-1c (SREBP-1c) and increased carnitine palmitoyltransferase‑1B (CPT1B) expression were observed after insulin administration. Moreover, increased ATP concentration and cellular energy charge elicited by over-nutrition were suppressed by insulin. Despite maintaining respiratory complex activities, insulin restored muscular uncoupling protein 3 (UCP3) protein expression in vitro and in vivo. By contrast, knockdown of UCP3 abrogated insulin-induced restoration of AMPK phosphorylation in vitro. Importantly, the PA-induced decrease in UCP3 was blocked by the proteasome inhibitor MG132, and insulin reduced UCP3 ubiquitination, thereby prohibiting its degradation. Our findings, focusing on energy balance, provide a mechanistic understanding of the promising effect of early insulin initiation on lipotoxicity. Insulin, by recovering UCP3 activity, alleviated energy surfeit and potentiated AMPK-mediated lipid homeostasis in skeletal muscle cells following exposure to PA and in gastrocnemius of mice fed HFD.

The Application of SUDOSCAN for Screening Diabetic Peripheral Neuropathy in Chinese Population

PURPOSE

Diabetic peripheral neuropathies are the common chronic complications of diabetes, but the diagnosis is insensitive by physical examination in busy outpatients. Here we evaluated the performance of SUDOSCAN in screening diabetic peripheral neuropathies in Chinese type 2 diabetic patients.

METHODS

The study enrolled 180 patients for annually screening. All patients underwent neurological symptoms assessment, clinical examination, nerve conduction studies and cardiovascular autonomic reflex tests. SUDOSCAN was tested and evaluated with electrochemical skin conductance in hands and feet, asymmetry ratio in hands and feet and predicted cardiac neuropathy.

RESULTS

Patients enrolled had an average age of 56.1 years, 9.8 years of diabetic duration. Patients with diabetic sensorimotor polyneuropathy showed significantly lower electrochemical skin conductance in feet and higher asymmetry ratio in feet compared with those without. Sensitivity and specificity of asymmetry ratio in feet for diagnosing diabetic sensorimotor polyneuropathy were 88.2% and 46.9% and area under ROC curve was 0.713. Patients with cardiovascular autonomic neuropathy showed significantly lower electrochemical skin conductance in hands and feet, and higher asymmetry ratio in feet and predicted cardiac neuropathy compared with those without. Sensitivity and specificity of electrochemical skin conductance in feet in diagnosing cardiovascular autonomic neuropathy were 85.6% and 76.1% with an area under ROC curve of 0.859.

CONCLUSIONS

SUDOSCAN is a sensitive test to detect diabetic peripheral neuropathy in China and could be an effective screening tool in in busy outpatients and primary health care.

Gender and Age Differences in Lipid Profile Among Chinese Adults in Nanjing: a Retrospective Study of Over 230,000 Individuals from 2009 to 2015

Background Previous national survey suggested that dyslipidemia is an increasing burden in China and more severe in urban population. In this study, we retrospectively analyzed the gender and age differences in lipids and lipoproteins in a large Chinese urban population in Nanjing city.

Methods A total of 236, 945 adults (age ≥20 years old) who undertook a health check between 2009 and 2015 in our medical examination center were involved in the analysis. Fasting total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglyceride (TG) were measured by standard methods.

Results The age-standardized estimates of serum total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride were 4.77 (4.76–4.79), 1.19 (1.18–1.19), 2.53 (2.52–2.54) and 1.74 (1.72–1.76) mmol/L in males (n=130954), and 4.79 (4.78–4.80), 1.46 (1.45–1.46), 2.44 (2.43–2.45) and 1.21 (1.19–1.22) mmol/L in females (n=105991), respectively. The prevalence of dyslipidemia was significantly elevated in females above 50 years old, and the peak prevalence of dyslipidemia in males was in the age group of 40–59 years, earlier as compared to females (peaked at 60–69 years old). In addition, an increasing secular trend was observed in LDL cholesterol levels from 2009 to 2015 in both males and females.

Conclusions Dyslipidemia is an increasing epidemic in China, characterized by a rising trend of LDL cholesterol. The gender and age differences in serum levels of lipid profile as well as prevalence of dyslipidemia suggested that the middle-age men and postmenopausal women should be the prioritized target for better control of dyslipidemia and early prevention of cardiovascular disease.

[Dietary intake status of Chinese lactating women during the first month postpartum in 2013]

Objective: To assess the dietary intake status of Chinese lactating women during the first month postpartum. Methods: Data were extracted from Chinese National Nutrition and Health Surveillance, children aged 0-5 years and lactating women (2013). A total of 55 counties from 30 provinces in China (excluding the Tibet Autonomous Region) were selected using a multi-stage stratified cluster randomization sampling method. A group of 3 623 lactating women, at 1-6 months after delivery, were investigated in the study. The semi-quantitative food frequency questionnaire (FFQ) was used to collect information on frequencies and amounts of food consumed. Differences in food consumption rates and dietary intake in lactating women having different characteristics were analyzed and compared. Results: To eliminate abnormal values, 3 300 lactating women were included in the study. During the first month postpartum, food types with higher consumption rates were animal products (98.2%, 3 239) and vegetables (90.7%, 2 987), in addition to cereals (100%) and liquids (100%). The consumption rate of fruits was 67.4% (2 222) and the lowest consumption rate was for dairy products (38.3%, 1 262). The median intake of cereals, vegetables, fruits and animal products were 247.8, 150.0, 40.0 and 178.6 g/d, respectively. The daily median intake of dairy products and soybean/nut products was 0.0 g/d. Overall, the lactating women consumed 895.7 ml/d liquids. About 49.3% (1 627) of the subjects consumed less than the recommended intake for animal products in Chinese Dietary Guideline (2016). More than 50% of the lactating women consumed less than the recommended intakes for the other types of food, especially dairy, soybean/nut and liquids. The consumption rates for dairy products were 26.9%, 29.4%, 31.8% and 33.8% and those for soybean/nut products were 33.9% , 35.8% , 37.5% and 41.7% for the lactating women living in rural areas, with educations at junior high school level and below, with average family incomes under 15 000 yuan per capita in 2012 and who work as household mothers, respectively. These consumption rates for dairy and soybean/nuts were significantly lower than those in women living in cities (48.4%, 55.0%), with an education level of senior high school or above (48.8%, 55.7%), with average family income over 15 000 yuan per capita in 2012 (45.5%, 52.8%) and who work outside the home (43.7%, 49.4%). P values were <0.05 for all comparisons. Conclusion: The daily intake of all foods by lactating women during the first month postpartum was lower than the levels recommended in Chinese Dietary Guideline (2016). The consumption rate of dairy and soybean/nut products during this time period was low, especially for those living in rural areas, with education levels of junior high school and below, with average family incomes less than 15 000 yuan per capita in 2012 and who are housemothers.

Silymarin protects against renal injury through normalization of lipid metabolism and mitochondrial biogenesis in high fat-fed mice

Obesity is associated with an increased risk of chronic kidney diseases and the conventional treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors is not enough to prevent renal injury and prolong the progression of disease. Recently, silymarin has shown protective effects on renal tissue injury, but the underlying mechanisms remain elusive. The goal of this study was to investigate the potential capacity of silymarin to prevent renal injury during obesity induced by high fat diet (HFD) in mice. In vivo, male C57BL/6 mice received HFD (60% of total calories) for 12 weeks, randomized and treated orally with vehicle saline or silymarin (30mg/kg body weight/d) for 4 weeks. In vitro, human proximal tubular epithelial cells (HK2) were exposed to 300μM palmitic acid (PA) for 36h followed by silymarin administration at different concentrations. The administration of silymarin significantly ameliorated HFD induced glucose metabolic disorders, oxidative stress and pathological alterations in the kidney. Silymarin significantly mitigated renal lipid accumulation, fatty acid β-oxidation and mitochondrial biogenesis in HFD mice and PA treated HK2 cells. Furthermore, silymarin partly restored mitochondrial membrane potential of HK2 cells after PA exposure. In conclusion, silymarin can improve oxidative stress and preserve mitochondrial dysfunction in the kidney, potentially via preventing accumulation of renal lipids and fatty acid β-oxidation.

Randomized trial comparing the effects of gliclazide, liraglutide, and metformin on diabetes with non-alcoholic fatty liver disease

BACKGROUND

The aim of the present study was to compare the effects of gliclazide, liraglutide, and metformin in type 2 diabetes mellitus (T2DM) patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

Eighty-seven subjects were randomized to receive liraglutide, metformin, or gliclazide for 24 weeks. Primary outcomes included HbA1c levels, intrahepatic fat (IHF) content, and liver function.

RESULTS

Both HbA1c levels and IHF content were reduced after treatment in all three groups. However, HbA1c levels were lower in the liraglutide- and metformin-treated groups than in the gliclazide-treated group, and reductions in IHF content were greater with liraglutide than with gliclazide. Liraglutide and metformin treatments reduced weight and improved liver function. Changes in IHF content were positively correlated with reductions in serum alanine aminotransferase and triglyceride levels, as well as weight. At 24 weeks, reductions in IHF content were greater in subjects with weight loss ≥5%, changes in waistline ≤0 cm (including decreases in waistline), HbA1c reductions ≥2.5%, and HbA1c levels <6.5%.

CONCLUSIONS

In T2DM patients with NAFLD, compared with liraglutide and metformin, gliclazide resulted in less improvement in liver function, reductions in IHF content and HbA1c levels, and less weight loss; in addition, slightly better improvements were achieved with liraglutide than with metformin.

Suppression of Rho-kinase 1 is responsible for insulin regulation of the AMPK/SREBP-1c pathway in skeletal muscle cells exposed to palmitate

AIMS

Clinical and experimental data suggest that early insulin therapy could reduce lipotoxicity in subjects and animal models with type 2 diabetes mellitus. However, the underlying mechanisms need to be clarified. Sterol regulatory element-binding protein 1c (SREBP-1c), which is negatively regulated by AMP-activated protein kinase (AMPK), plays a critical role in lipotoxicity and insulin resistance in skeletal muscle cells. Here, we investigated the effect and molecular mechanism of insulin intervention on the AMPK/SREBP-1c pathway in skeletal muscle cells with chronic exposure to palmitic acid (PA).

METHODS

Male C57BL/6 mice were fed with a high-fat diet for 12 weeks and were then treated with insulin, AMPK inhibitor, or metformin. L6 myotubes incubated with palmitic acid (PA) were treated with insulin or metformin. Dominant-negative AMPKα2 (DN-AMPKα2) lentivirus, AMPKα2 siRNA, or Rho-kinase 1 (ROCK1) siRNA were transfected into PA-treated L6 myotubes.

RESULTS

We found that the ability of PA to stimulate SREBP-1c and inhibit AMPK was reversed by insulin in L6 cells. Moreover, DN-AMPKα2 lentivirus and AMPKα2 siRNA were transfected into PA-treated L6 myotubes, and the decrease in SREBP-1c expression caused by insulin was blocked by AMPK inhibition independent of the phosphatidylinositol-4,5-biphosphate-3-kinase (PI3K)/AKT pathway. The serine/threonine kinase Rho-kinase (ROCK) 1, a downstream effector of the small G protein RhoA, was activated by PA. Interestingly, knockdown of ROCK1 by siRNA blocked the downregulation of AMPK phosphorylation under PA-treated L6 myotubes, which indicated that ROCK1 mediated the effect of insulin action on AMPK.

CONCLUSIONS

Our study indicated that insulin reduced lipotoxicity via ROCK1 and then improved AMPK/SREBP-1c signaling in skeletal muscle under PA-induced insulin resistance.

No association between SLC6A2, SLC6A3, DRD2 polymorphisms and schizophrenia in the Han Chinese population

This study was intended to ascertain whether SNPs in dopaminergic and serotoninergic pathway genes SLC6A2, SLC6A3 and DRD2 are associated with schizophrenia in Han Chinese people. We conducted a case-control study by genotyping 7 SNPs of the three genes in 1034 schizophrenia patients and 1034 controls. No significant difference in the allelic or genotypic frequency was detected between cases and controls despite one positive haplotype (rs1362621-rs2242446-rs5564). Stratified analysis of gender and gene-gene interaction analysis showed no positive results. In summary, our study denies the major role of these SNPs within the three genes for schizophrenia in Han Chinese.

Modulation of gut microbiota contributes to curcumin-mediated attenuation of hepatic steatosis in rats

BACKGROUND

Structural disruption of gut microbiota contributes to the development of non-alcoholic fatty liver disease (NAFLD) and modulating the gut microbiota represents a novel strategy for NAFLD prevention. Although previous studies have demonstrated that curcumin alleviates hepatic steatosis, its effect on the gut microbiota modulation has not been investigated.

METHODS

Next generation sequencing and multivariate analysis were utilized to evaluate the structural changes of gut microbiota in a NAFLD rat model induced by high fat-diet (HFD) feeding.

RESULTS

We found that curcumin attenuated hepatic ectopic fat deposition, improved intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD-fed rats. More importantly, curcumin dramatically shifted the overall structure of the HFD-disrupted gut microbiota toward that of lean rats fed a normal diet and altered the gut microbial composition. The abundances of 110 operational taxonomic units (OTUs) were altered by curcumin. Seventy-six altered OTUs were significantly correlated with one or more hepatic steatosis associated parameters and designated 'functionally relevant phylotypes'. Thirty-six of the 47 functionally relevant OTUs that were positively correlated with hepatic steatosis associated parameters were reduced by curcumin.

CONCLUSION

These results indicate that curcumin alleviates hepatic steatosis in part through stain-specific impacts on hepatic steatosis associated phylotypes of gut microbiota in rats.

GENERAL SIGNIFICANCE

Compounds with antimicrobial activities should be further investigated as novel adjunctive therapies for NAFLD.