Upregulated NLRP3 inflammasome activation in patients with type 2 diabetes

Despite the recent attention focused on the roles of the nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in the pathogenesis of type 2 diabetes, little is known about the ex vivo profile of inflammasome activation in type 2 diabetic patients. In this study, we investigated patterns of NLRP3 inflammasome activation in monocyte-derived macrophages (MDMs) from drug-naïve patients with newly diagnosed type 2 diabetes. Type 2 diabetic subjects had significantly increased mRNA and protein expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and proinflammatory cytokines in MDMs cultured with autologous sera compared with healthy controls. Upregulated interleukin (IL)-1β maturation, IL-18 secretion, and caspase-1 cleavage were observed in MDMs from type 2 diabetic patients after stimulation with various danger molecules (ATP, high-mobility group protein B1, free fatty acids, islet amyloid polypeptide, and monosodium uric acid crystals). Mitochondrial reactive oxygen species and NLRP3 were required for IL-1β synthesis in MDMs. Finally, 2 months of therapy with the antidiabetic drug metformin significantly inhibited the maturation of IL-1β in MDMs from patients with type 2 diabetes through AMP-activated protein kinase (AMPK) activation. Taken together, these data suggest that NLRP3 inflammasome activation is elevated in myeloid cells from type 2 diabetic patients and that antidiabetic treatment with metformin contributes to modulation of inflammasome activation in type 2 diabetes.

The Roles of Adipokines, Proinflammatory Cytokines, and Adipose Tissue Macrophages in Obesity-Associated Insulin Resistance in Modest Obesity and Early Metabolic Dysfunction

The roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in obesity-associated insulin resistance have been explored in both animal and human studies. However, our current understanding of obesity-associated insulin resistance relies on studies of artificial metabolic extremes. The purpose of this study was to explore the roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in human patients with modest obesity and early metabolic dysfunction. We obtained omental adipose tissue and fasting blood samples from 51 females undergoing gynecologic surgery. We investigated serum concentrations of proinflammatory cytokines and adipokines as well as the mRNA expression of proinflammatory and macrophage phenotype markers in visceral adipose tissue using ELISA and quantitative RT-PCR. We measured adipose tissue inflammation and macrophage infiltration using immunohistochemical analysis. Serum levels of adiponectin and leptin were significantly correlated with HOMA-IR and body mass index. The levels of expression of MCP-1 and TNF-α in visceral adipose tissue were also higher in the obese group (body mass index ≥ 25). The expression of mRNA MCP-1 in visceral adipose tissue was positively correlated with body mass index (r = 0.428, p = 0.037) but not with HOMA-IR, whereas TNF-α in visceral adipose tissue was correlated with HOMA-IR (r = 0.462, p = 0.035) but not with body mass index. There was no obvious change in macrophage phenotype or macrophage infiltration in patients with modest obesity or early metabolic dysfunction. Expression of mRNA CD163/CD68 was significantly related to mitochondrial-associated genes and serum inflammatory cytokine levels of resistin and leptin. These results suggest that changes in the production of inflammatory biomolecules precede increased immune cell infiltration and induction of a macrophage phenotype switch in visceral adipose tissue. Furthermore, serum resistin and leptin have specific roles in the regulation of adipose tissue macrophages in patients with modest obesity or early metabolic dysfunction.

Signal transducer and activator of transcription-3 (Stat3) plays a critical role in implantation via progesterone receptor in uterus

Recent studies have shown that activation of the signal transducer and activator of transcription-3 (Stat3) is required for decidualization, interacting with progesterone receptor (PR) in uterus. Based on previous reports, we hypothesized that crosstalk between STAT3 and PR signaling is required for successful implantation. To identify the interaction between STAT3 and PR isoforms, we performed immunoprecipitation following transient cotransfection and found that STAT3 physically interacted with PR-A, which is known to be important for uterine development and function, but not with PR-B. To further investigate the role of Stat3 in uterine function, Stat3 was conditionally ablated only in the PR-positive cells (PR(cre/+) Stat3(f/f); Stat3(d/d)). Our studies revealed that ovarian function and uterine development of Stat3(d/d) mice were normal. However, Stat3(d/d) female mice were infertile due to defective embryo implantation. Unlike Stat3(f/f) mice, Stat3(d/d) mice exhibited an unclosed uterine lumen. Furthermore, uteri of Stat3(d/d) mice were unable to undergo a well-characterized hormonally induced decidual reaction. The expression of stromal PR was decreased during decidualization and preimplantation period in Stat3(d/d) mice, and PR target genes were significantly down-regulated after progesterone induction. Our results suggest that STAT3 and PR crosstalk is required for successful implantation in the mouse uterus.

Elucidation of Akkermansia muciniphila Probiotic Traits Driven by Mucin Depletion

Akkermansia muciniphila is widely considered a next-generation beneficial microbe. This bacterium resides in the mucus layer of its host and regulates intestinal homeostasis and intestinal barrier integrity by affecting host signaling pathways. However, it remains unknown how the expression of genes encoding extracellular proteins is regulated in response to dynamic mucosal environments. In this study, we elucidated the effect of mucin on the gene expression and probiotic traits of A. muciniphila. Transcriptome analysis showed that the genes encoding most mucin-degrading enzymes were significantly upregulated in the presence of mucin. By contrast, most genes involved in glycolysis and energy metabolic pathways were upregulated under mucin-depleted conditions. Interestingly, the absence of mucin resulted in the upregulation of 79 genes encoding secreted protein candidates, including Amuc-1100 as well as members of major protein secretion systems. These transcript level changes were consistent with the fact that administration of A. muciniphila grown under mucin-depleted conditions to high-fat diet-induced diabetic mice reduced obesity and improved intestinal barrier integrity more efficiently than administration of A. muciniphila grown under mucin-containing conditions. In conclusion, mucin content in the growth medium plays a critical role in the improvement by A. muciniphila of high-fat diet-induced obesity, intestinal inflammation, and compromised intestinal barrier integrity related to a decrease in goblet cell density. Our findings suggest the depletion of animal-derived mucin in growth medium as a novel principle for the development of A. muciniphila for human therapeutics.

GDF15 Is a Novel Biomarker for Impaired Fasting Glucose

BACKGROUND

Growth differentiation factor-15 (GDF15) is a protein that belongs to the transforming growth factor β superfamily. An elevated serum level of GDF15 was found to be associated with type 2 diabetes mellitus (T2DM). T2DM is an inflammatory disease that progresses from normal glucose tolerance (NGT) to impaired fasting glucose (IFG). Hence, we aimed to validate the relationship between GDF15 and IFG.

METHODS

The participants were divided into the following three groups: NGT (n=137), IFG (n=29), and T2DM (n=75). The controls and T2DM outpatients visited the hospital for routine health check-ups. We used fasting blood glucose to detect IFG in nondiabetic patients. We checked the body mass index (BMI), C-reactive protein level, metabolic parameters, and fasting serum GDF15 level.

RESULTS

Age, BMI, triglyceride, insulin, glucose, homeostatic model assessment-insulin resistance (HOMA-IR), and GDF15 levels were elevated in the IFG and T2DM groups compared to the NGT group. In the correlation analysis between metabolic parameters and GDF15, age and HOMA-IR had a significant positive correlation with GDF15 levels. GDF15 significantly discriminated between IFG and NGT, independent of age, BMI, and HOMA-IR. The serum levels of GDF15 were more elevated in men than in women. As a biomarker for IFG based on the receiver operating characteristic curve analysis, the cutoff value of GDF15 was 510 pg/mL in males and 400 pg/mL in females.

CONCLUSION

GDF15 had a positive correlation with IR independent of age and BMI, and the serum level of GDF15 was increased in the IFG and T2DM groups. GDF15 may be a novel biomarker for detecting IFG in nondiabetic patients.

T-cell senescence contributes to abnormal glucose homeostasis in humans and mice

Chronic inflammation is a driving force for the development of metabolic disease including diabetes and obesity. However, the functional characteristics of T-cell senescence in the abnormal glucose homeostasis are not fully understood. We studied the patients visiting a hospital for routine health check-ups, who were divided into two groups: normal controls and people with prediabetes. Gene expression profiling of peripheral blood mononuclear cells from normal controls and patients with type 2 diabetes was undertaken using microarray analysis. We also investigated the immunometabolic characteristics of peripheral and hepatic senescent T cells in the normal subjects and patients with prediabetes. Moreover, murine senescent T cells were tested functionally in the liver of normal or mice with metabolic deterioration caused by diet-induced obesity. Human senescent (CD28^-CD57⁺) CD8⁺ T cells are increased in the development of diabetes and proinflammatory cytokines and cytotoxic molecules are highly expressed in senescent T cells from patients with prediabetes. Moreover, we demonstrate that patients with prediabetes have higher concentrations of reactive oxygen species (ROS) in their senescent CD8⁺ T cells via enhancing capacity to use glycolysis. These functional properties of senescent CD8⁺ T cells contribute to the impairment of hepatic insulin sensitivity in humans. Furthermore, we found an increase of hepatic senescent T cells in mouse models of aging and diet-induced obesity. Adoptive transfer of senescent CD8⁺ T cells also led to a significant deterioration in systemic abnormal glucose homeostasis, which is improved by ROS scavengers in mice. This study defines a new clinically relevant concept of T-cell senescence-mediated inflammatory responses in the pathophysiology of abnormal glucose homeostasis. We also found that T-cell senescence is associated with systemic inflammation and alters hepatic glucose homeostasis. The rational modulation of T-cell senescence would be a promising avenue for the treatment or prevention of diabetes.

ARID1A Is Essential for Endometrial Function during Early Pregnancy

AT-rich interactive domain 1A gene (ARID1A) loss is a frequent event in endometriosis-associated ovarian carcinomas. Endometriosis is a disease in which tissue that normally grows inside the uterus grows outside the uterus, and 50% of women with endometriosis are infertile. ARID1A protein levels were significantly lower in the eutopic endometrium of women with endometriosis compared to women without endometriosis. However, an understanding of the physiological effects of ARID1A loss remains quite poor, and the function of Arid1a in the female reproductive tract has remained elusive. In order to understand the role of Arid1a in the uterus, we have generated mice with conditional ablation of Arid1a in the PGR positive cells (Pgrcre/+Arid1af/f; Arid1ad/d). Ovarian function and uterine development of Arid1ad/d mice were normal. However, Arid1ad/d mice were sterile due to defective embryo implantation and decidualization. The epithelial proliferation was significantly increased in Arid1ad/d mice compared to control mice. Enhanced epithelial estrogen activity and reduced epithelial PGR expression, which impedes maturation of the receptive uterus, was observed in Arid1ad/d mice at the peri-implantation period. The microarray analysis revealed that ARID1A represses the genes related to cell cycle and DNA replication. We showed that ARID1A positively regulates Klf15 expression with PGR to inhibit epithelial proliferation at peri-implantation. Our results suggest that Arid1a has a critical role in modulating epithelial proliferation which is a critical requisite for fertility. This finding provides a new signaling pathway for steroid hormone regulation in female reproductive biology and furthers our understanding of the molecular mechanisms that underlie dysregulation of hormonal signaling in human reproductive disorders such as endometriosis.

The Impact of Social Support on Self-care of Patients With Diabetes: What Is the Effect of Diabetes Type? Systematic Review and Meta-analysis

Purpose This meta-analysis examined relationships between social support and self-care in type 1 (T1DM) and 2 diabetes mellitus (T2DM). Methods We searched for published and unpublished studies using the following databases: PubMed, Embase, PsycINFO, the Cochrane Library, and Medline. MeSH search terms included "diabetes mellitus," "social support," "caregiver," "self-care," "self-management," "self-care skills," and "coping behavior." Studies reporting correlations between social support and self-care were included. Results Initially, 2 095 studies were extracted. After eliminating duplicate and irrelevant studies, 28 studies involving 5 242 patients with diabetes were included. Of these, 22 studies examined T2DM subjects. Social support was significantly associated with self-care ( k = 28, r = .28, 95% CI: .21-.34, P < .001). Among the diabetes self-care types, the strongest effect was found for glucose monitoring ( k = 6, r = .21, 95% CI: .08-.33). The relationship between social support and self-care was stronger in T2DM ( k = 22, r = .30, 95% CI: .22-.37), relative to T1DM, samples ( k = 5, r = .22, 95% CI: .02-.38). Conclusion It was concluded that the overall effect size for social support on self-care was moderate, and its strength differed by ethnic majority within the sample, type of social support measures, and publication status.

Extracellular signal-regulated kinase 1/2 signaling pathway is required for endometrial decidualization in mice and human

Decidualization is a crucial change required for successful embryo implantation and the maintenance of pregnancy. During this process, endometrial stromal cells differentiate into decidual cells in response to the ovarian steroid hormones of early pregnancy. Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) are known to regulate cell proliferation and apoptosis in multiple cell types, including uterine endometrial cells. Aberrant activation of ERK1/2 has recently been implicated in the pathological processes of endometriosis and endometrial cancer. However, the function of ERK1/2 signaling during implantation and decidualization is still unknown. To determine the role and regulation of ERK1/2 signaling during implantation and decidualization, we examine ERK1/2 signaling in the mouse uterus during early pregnancy using immunostaining and qPCR. Interestingly, levels of phospho-ERK1/2 were highest within decidual cells located at the implantation sites. Expression levels of ERK1/2 target genes were also significantly higher at implantation sites, when compared to either inter-implantation sites. To determine if ERK1/2 signaling is also important during human endometrial decidualization, we examined levels of phospho-ERK1/2 in cultured human endometrial stromal cells during in vitro decidualization. Following treatment with a well-established decidualization-inducing steroidogenic cocktail, levels of phospho-ERK1/2 were markedly increased. Treatment with the ERK1/2 inhibitor, U0126, significantly decreased the expression of the known decidualization marker genes, IGFBP1 and PRL as well as inhibited the induction of known ERK1/2 target genes; FOS, MSK1, STAT1, and STAT3. Interestingly, the phosphorylation level of CCAAT/ enhancer binding protein β (C/EBPβ), a protein previously shown to be critical for decidualization, was significantly reduced in this model. These results suggest that ERK1/2 signaling is required for successful decidualization in mice as well as human endometrial stromal cells and implicates C/EBPβ as a downstream target of ERK1/2.

Serum Meteorin-like protein levels decreased in patients newly diagnosed with type 2 diabetes

We analyzed circulating Meteorin-like (METRNL) levels in human. Serum METRNL levels were significantly lower in subjects with diabetes mellitus compared with those without diabetes. Serum METRNL was negatively correlated with the serum glucose level and insulin resistance. Metformin treatment did not increase the serum METRL levels after 12 weeks.

Association between Growth Differentiation Factor 15 (GDF15) and Cardiovascular Risk in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

We investigated an association between serum Growth Differentiation Factor 15 (GDF15) level and cardiovascular risk in patients with newly diagnosed type 2 diabetes mellitus (T2D). A total of 107 participants were screened for T2D and divided into a T2D group and a control group (without diabetes). We used the Framingham risk score (FRS) and the New Pooled Cohort Equation score to estimate the 10-year risk of atherosclerotic cardiovascular disease. Serum GDF15 levels were measured using an enzyme-linked immunosorbent assay. Correlation analyses were performed to evaluate the associations between GDF15 level and cardiovascular risk scores. The mean serum GDF15 level was elevated in the T2D group compared to the control group (P < 0.001). A positive correlation was evident between serum GDF15 level and age (r = 0.418, P = 0.001), the FRS (r = 0.457, P < 0.001), and the Pooled Cohort Equation score (r = 0.539, P < 0.001). After adjusting for age, LDL-C level, and body mass index (BMI), the serum GDF15 level was positively correlated with the FRS and the New Pooled Cohort Equation score. The serum GDF15 level is independently associated with cardiovascular risk scores of newly diagnosed T2D patients. This suggests that the level of GDF15 may be a useful predictive biomarker of cardiovascular risk in newly diagnosed T2D patients.

Growth Differentiation Factor 15 Predicts Chronic Liver Disease Severity

Background/Aims

Growth differentiation factor 15 (GDF-15) belongs to the transforming growth factor-β superfamily. GDF-15 is emerging as a biomarker for several diseases. The aim of this study was to determine the clinical performances of GDF-15 for the prediction of liver fibrosis and severity in chronic liver disease.

Methods

The serum GDF-15 levels were examined via enzyme immunoassay in 145 patients with chronic liver disease and 101 healthy individuals. The patients with chronic liver disease consisted of 54 patients with chronic hepatitis, 44 patients with compensated liver cirrhosis, and 47 patients with decompensated liver cirrhosis.

Results

Of the patients with chronic liver diseases, the decompensated liver cirrhosis patients had an increased serum GDF-15 (3,483 ng/L) level compared with the patients with compensated liver cirrhosis (1,861 ng/L) and chronic hepatitis (1,232 ng/L). The overall diagnostic accuracies of GDF-15, as determined by the area under the receiver operating characteristic curves, were as follows: chronic hepatitis=0.656 (>574 ng/L, sensitivity, 53.7%; specificity, 79.2%), compensated liver cirrhosis=0.886 (>760 ng/L, sensitivity, 75.6%; specificity, 92.1%), and decompensated liver cirrhosis=0.984 (>869 ng/L, sensitivity, 97.9%; specificity, 94.1%).

Conclusions

This investigation represents the first study to demonstrate the availability of GDF-15 in chronic liver disease. GDF-15 comprised a useful biomarker for the prediction of liver fibrosis and severity in chronic liver disease.

Epidermal growth factor receptor inhibition attenuates non-alcoholic fatty liver disease in diet-induced obese mice

Non-alcoholic fatty liver disease (NAFLD) is one of the main causes of chronic liver disease. NAFLD begins with excessive lipid accumulation in the liver and progresses to nonalcoholic steatohepatitis (NASH) and cirrhosis. NAFLD is closely linked to dysregulated hepatic lipid metabolism. Although recent studies have reported that epidermal growth factor receptor (EGFR) signaling regulates lipid metabolism, the roles of EGFR and EGFR inhibitors as modulators of lipid metabolism are largely unknown. Here, we investigated whether inhibiting EGFR using the EGFR tyrosine kinase inhibitor (TKI) PD153035 improves NAFLD. Our results demonstrate that EGFR was activated in liver tissues from high fat diet (HFD)-induced NAFLD mice. Inhibiting EGFR using PD153035 significantly reduced phosphatidylinositol-3-kinase/protein kinase B signaling and sterol responsive elementary binding protein 1 and 2 expression, which prevented HFD-induced hepatic steatosis and hypercholesterolemia by reducing de novo lipogenesis and cholesterol synthesis and enhancing fatty acid oxidation. Additionally, inhibiting EGFR improved HFD-induced glucose intolerance. In conclusion, these results indicate that EGFR plays an important role in NAFLD and is a potential therapeutic target.

Lobeglitazone and pioglitazone as add-ons to metformin for patients with type 2 diabetes: a 24-week, multicentre, randomized, double-blind, parallel-group, active-controlled, phase III clinical trial with a 28-week extension

We aimed to compare the efficacy and safety of lobeglitazone and pioglitazone as add-ons to metformin in patients with type 2 diabetes. Patients who were inadequately controlled by metformin were randomized and treated once daily with either lobeglitazone (0.5 mg, n = 128) or pioglitazone (15 mg, n = 125) for 24 weeks, with a 28-week extension trial of lobeglitazone treatment in patients who consented. The primary endpoint was the change in glycated haemoglobin (HbA1c) concentration from baseline to week 24. At week 24, the mean change from baseline in HbA1c was -0.74% for the lobeglitazone group and -0.74% for the pioglitazone group, with a mean difference of 0.01% [95% confidence interval (CI) of difference, -0.16 to 0.18]. The effects of lobeglitazone on lipid variables and the adverse events associated with lobeglitazone were similar to those observed with pioglitazone. Lobeglitazone was not inferior to pioglitazone as an add-on to metformin in terms of their efficacy and safety.

Mig-6 suppresses endometrial cancer associated with Pten deficiency and ERK activation

PTEN mutations are the most common genetic alterations in endometrial cancer. Loss of PTEN and subsequent AKT activation stimulate estrogen receptor α-dependent pathways that play an important role in endometrial tumorigenesis. The major pathologic phenomenon of endometrial cancer is the loss of ovarian steroid hormone control over uterine epithelial cell proliferation and apoptosis. However, the precise mechanism of PTEN/AKT signaling in endometrial cancer remains poorly understood. The progesterone signaling mediator MIG-6 suppresses estrogen signaling and it has been implicated previously as a tumor suppressor in endometrial cancer. In this study, we show that MIG-6 also acts as a tumor suppressor in endometrial cancers associated with PTEN deficiency. Transgenic mice, where Mig-6 was overexpressed in progesterone receptor-expressing cells, exhibited a relative reduction in uterine tumorigenesis caused by Pten deficiency. ERK1/2 was phosphorylated in uterine tumors and administration of an ERK1/2 inhibitor suppressed cancer progression in PR(cre/+)Pten(f/f) mice. In clinical specimens of endometrial cancer, MIG-6 expression correlated inversely with ERK1/2 phosphorylation during progression. Taken together, our findings suggest that Mig-6 regulates ERK1/2 phosphorylation and that it is crucial for progression of PTEN-mutant endometrial cancers, providing a mechanistic rationale for the evaluation of ERK1/2 inhibitors as a therapeutic treatment in human endometrial cancer.

Efficacy and safety of teneligliptin, a dipeptidyl peptidase-4 inhibitor, combined with metformin in Korean patients with type 2 diabetes mellitus: a 16-week, randomized, double-blind, placebo-controlled phase III trial

The aim of the present study was to assess the efficacy and safety of teneligliptin in combination with metformin in Korean patients with type 2 diabetes mellitus who were inadequately controlled with metformin monotherapy. Patients [glycated haemoglobin (HbA1c) 7.0-10.0%, on stable metformin ≥1000 mg/day] were randomized 2 : 1 to receive 20 mg teneligliptin plus metformin (n = 136) or placebo plus metformin (n = 68). The primary endpoint was the change in HbA1c levels from baseline to week 16. The mean baseline HbA1c was 7.9% in the teneligliptin group and 7.8% in the placebo group. The differences between the teneligliptin and placebo groups regarding changes in HbA1c and fasting plasma glucose levels were -0.78 % and -1.24 mmol/l (22.42 mg/dl), respectively, at week 16. The incidence of adverse events was similar between the groups. The addition of teneligliptin once daily to metformin was effective and generally well tolerated in Korean patients with type 2 diabetes.

Critical tumor suppressor function mediated by epithelial Mig-6 in endometrial cancer

Endometrial cancer is preceded by endometrial hyperplasia, unopposed estrogen exposure, and genetic alterations, but the precise causes of endometrial cancer remain uncertain. Mig-6, mainly known as a negative regulator of the EGF receptor, is an important mediator of progesterone signaling in the uterus, where it mediates tumor suppression by modulating endometrial stromal-epithelial communications. In this study, we investigated the function of Mig-6 in the uterine epithelium using a tissue-specific gene knockout strategy, in which floxed Mig-6 (Mig-6(f/f)) mice were crossed to Wnt7a-Cre mice (Wnt7a(cre+)Mig-6(f/f)). Wnt7a(cre+)Mig-6(f/f) mice developed endometrial hyperplasia and estrogen-dependent endometrial cancer, exhibiting increased proliferation in epithelial cells as well as apoptosis in subepithelial stromal cells. We documented increased expression of NOTCH1 and BIRC3 in epithelial cells of Wnt7a(cre+)Mig-6(f/f) mice and decreased expression of the progesterone receptor (PR) in stromal cells. Progesterone therapy controls endometrial growth and prevents endometrial cancer, but the effectiveness of progesterone as a treatment for women with endometrial cancer is less clear. We noted that the hyperplasic phenotype of Wnt7a(cre+)Mig-6(f/f) mice was prevented by progesterone treatment, whereas this treatment had no effect in PR(cre/+)Mig-6(f/f) mice where Mig-6 was deleted in both the epithelial and stromal compartments of the uterus. In contrast, activation of progesterone signaling in the stroma regulated proliferation and apoptosis in the epithelium via suppression of ERα signaling. In summary, our results establish that epithelial Mig-6 functions as a critical tumor suppressor that mediates the ability of progesterone to prevent the development of endometrial cancer.

Mig-6 plays a critical role in the regulation of cholesterol homeostasis and bile acid synthesis

The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, stresses, and hormones. To identify the metabolic role of Mig-6 in the liver, we conditionally ablated Mig-6 in the liver using the Albumin-Cre mouse model (Alb^cre/+Mig-6^f/f; Mig-6^d/d). Mig-6^d/d mice exhibit hepatomegaly and fatty liver. Serum levels of total, LDL, and HDL cholesterol and hepatic lipid were significantly increased in the Mig-6^d/d mice. The daily excretion of fecal bile acids was significantly decreased in the Mig-6^d/d mice. DNA microarray analysis of mRNA isolated from the livers of these mice showed alterations in genes that regulate lipid metabolism, bile acid, and cholesterol synthesis, while the expression of genes that regulate biliary excretion of bile acid and triglyceride synthesis showed no difference in the Mig-6^d/d mice compared to Mig-6^f/f controls. These results indicate that Mig-6 plays an important role in cholesterol homeostasis and bile acid synthesis. Mice with liver specific conditional ablation of Mig-6 develop hepatomegaly and increased intrahepatic lipid and provide a novel model system to investigate the genetic and molecular events involved in the regulation of cholesterol homeostasis and bile acid synthesis. Defining the molecular mechanisms by which Mig-6 regulates cholesterol homeostasis will provide new insights into the development of more effective ways for the treatment and prevention of cardiovascular disease.

Delay of insulin initiation in patients with type 2 diabetes mellitus inadequately controlled with oral hypoglycemic agents (analysis of patient- and physician-related factors): A prospective observational DIPP-FACTOR study in Korea

Aims/Introduction

To assess the time to initiation of insulin therapy, and concurrently investigate both patient‐ and physician‐related factors associated with delaying insulin therapy in Korean patients with type 2 diabetes uncontrolled by oral hypoglycemic agents (OHAs).

Materials and Methods

This prospective, observational disease registry study was carried out across 69 centers in Korea. Type 2 diabetes patients who had received two or more OHAs within the past 5 years, had a glycated hemoglobin ≥8% in the past 6 months and had not received insulin were included. Data recorded on data collection forms during a 12‐month period were analyzed.

Results

Of 2168 patients enrolled, 1959 were evaluated and classified as the insulin‐initiated or insulin‐delayed group. Insulin was prescribed for just 20% of the patients during a 1‐year follow‐up period, and less than half (44.5%) of the patients who were taking two OHAs started insulin after 6 years. Patient‐related factors for delay in insulin initiation included older age, shorter duration of diabetes and lower glycated hemoglobin. Physician‐related factors included age (~50 to <60 years), sex (women) and number (<1000) of patients consulted per month. Patient refusal (33.6%) and physicians’ concerns of patient non‐compliance (26.5%) were the major physician‐reported reasons for delaying insulin therapy. Inconvenience of insulin therapy (51.6%) and fear of injection (48.2%) were the major reasons for patient refusal.

Conclusions

Insulin initiation is delayed in patients with type 2 diabetes uncontrolled by two or more OHAs in Korea. Patient‐ and physician‐related factors associated with this delay need to be addressed for better diabetes management.

Gut microbiome signatures distinguish type 2 diabetes mellitus from non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is closely associated with type 2 diabetes mellitus (T2D), and these two metabolic diseases demonstrate bidirectional influences. The identification of microbiome profiles that are specific to liver injury or impaired glucose metabolism may assist understanding of the role of the gut microbiota in the relationship between NAFLD and T2D. Here, we studied a biopsy-proven Asian NAFLD cohort (n = 329; 187 participants with NAFLD, 101 with NAFLD and T2D, and 41 with neither) and identified Enterobacter, Romboutsia, and Clostridium sensu stricto as the principal taxa associated with the severity of NAFLD and T2D, whereas Ruminococcus and Megamonas were specific to NAFLD. In particular, the taxa that were associated with both severe liver pathology and T2D were also significantly associated with markers of diabetes, such as fasting blood glucose and Hb1Ac. Enterotype analysis demonstrated that participants with NAFLD had a significantly higher proportion of Bacteroides and a lower proportion of Ruminococcus than a Korean healthy twin cohort (n = 756). However, T2D could not be clearly distinguished from NAFLD. Analysis of an independent T2D cohort (n = 185) permitted us to validate the T2D-specific bacterial signature identified in the NAFLD cohort. Functional inference analysis revealed that endotoxin biosynthesis pathways were significantly enriched in participants with NAFLD and T2D, compared with those with NAFLD alone. These findings may assist with the development of effective therapeutic approaches for metabolic diseases that are associated with specific bacterial signatures.

The Role of Circulating Slit2, the One of the Newly Batokines, in Human Diabetes Mellitus

BACKGROUND

Slit2 is a new secreted protein from adipose tissue that improves glucose hemostasis in mice; however, there is no study about the serum levels and precise role of Slit2 in human. The aim of this study is to explore the serum level of Slit2 in human, and to identify the role of Slit2 in diabetes mellitus (DM).

METHODS

The participants of this study consist of 38 subjects with newly diagnosed DM, and 75 healthy subjects as a control group. Serum Slit2 levels were measured using an enzyme-linked immunosorbent assay. Relationship between circulating Slit2 and diabetic related factors was investigated in diabetic group compared with non-diabetic group. Additionally, the correlations between the serum level of Slit2 and diverse metabolic parameters were analyzed.

RESULTS

Circulating Slit2 level was more decreased in diabetic group than in control group, but there was no significant difference statistically. Interestingly, serum levels of Slit2 were significantly negatively correlated to the serum concentrations of fasting glucose (coefficient r=-0.246, P=0.008), the serum concentrations of postprandial glucose (coefficient r=-0.233, P=0.017), and glycosylated hemoglobin (HbA1c; coefficient r=-0.357, P<0.001).

CONCLUSION

From our study, the first report of circulating Slit2 levels in human, circulating Slit2 level significantly negatively correlated with serum glucose and HbA1c. Our results suggest that the circulating Slit2 may play a role in maintainence of glucose homeostasis in human, even though exact contribution and mechanism are not yet known.

Predictive Value of the Preablation Serum Thyroglobulin Level After Thyroidectomy Is Combined With Postablation 131I Whole Body Scintigraphy for Successful Ablation in Patients With Differentiated Thyroid Carcinoma

OBJECTIVES

To investigate the clinical importance of the combined use of serum thyroglobulin (Tg) levels measured just before ablation (ablation-Tg) and postablation 131I whole body scintigraphy (WBS) patterns for predicting ablation success in patients with differentiated thyroid carcinoma who received total thyroidectomy and 131I ablation therapy.

METHODS

We retrospectively studied the early clinical outcomes for 81 differentiated thyroid carcinoma patients treated with total thyroidectomy and high-dose 131I ablation therapy between June 2001 and July 2004.

RESULTS

Ablation success was achieved in 42 (97.7%) of the 43 patients with uptake in the thyroid bed only and ablation-Tg levels less than 10 ng/mL, whereas successful ablation was achieved in 9 (75.0%) of the 12 patients with uptake in the thyroid bed only and ablation-Tg levels equal to or greater than 10 ng/mL (P = 0.029). Among 15 patients with uptake including a lymph node and ablation-Tg levels less than 10 ng/mL, 14 patients (93.3%) showed ablation success, whereas successful ablation was achieved in only 2 (18.2%) of the 11 patients with uptake including a lymph node and ablation-Tg levels equal to or greater than 10 ng/mL (P < 0.001).

CONCLUSIONS

These data indicate that the combined use of serum Tg levels measured just before ablation and the 131I WBS patterns after ablation may be an early predictor of ablation success in patients with differentiated thyroid carcinoma who received total thyroidectomy and high-dose 131I ablation therapy.

Amelioration of hypercholesterolemia by an EGFR tyrosine kinase inhibitor in mice with liver-specific knockout of Mig-6

Mitogen-inducible gene 6 (Mig-6) is a negative feedback inhibitor of epidermal growth factor receptor (EGFR) signaling. We previously found that Mig-6 plays a critical role in the regulation of cholesterol homeostasis and in bile acid synthesis. In this study, we investigated the effects of EGFR inhibition to identify a potential new treatment target for hypercholesterolemia. We used a mouse model with conditional ablation of the Mig-6 gene in the liver (Alb^cre/+Mig-6^f/f; Mig-6^d/d) to effectively investigate the role of Mig-6 in the regulation of liver function. Mig-6^d/d mice were treated with either the EGFR inhibitor gefitinib or statin for 6 weeks after administration of a high-fat or standard diet. We then compared lipid profiles and other parameters among each group of mice. After a high-fat diet, Mig-6^d/d mice showed elevated serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and glucose, characteristics resembling hypercholesterolemia in diabetic patients. We observed decreases in serum levels of lipids and glucose in high-fat-diet-fed Mig-6^d/d mice after 6 weeks of treatment with gefitinib or statin. Furthermore gefitinib-treated mice showed significantly greater decreases in serum levels of total, HDL and LDL cholesterol compared with statin-treated mice. Taken together, these results suggest that EGFR inhibition is effective for the treatment of hypercholesterolemia in high-fat-diet-fed Mig-6^d/d mice, and our findings provide new insights into the development of possible treatment targets for hypercholesterolemia via modulation of EGFR inhibition.

Addition of Ipragliflozin to Metformin Treatment in Korean Patients with Type 2 Diabetes Mellitus: Subgroup Analysis of a Phase 3 Trial

BACKGROUND

This is a subgroup analysis of Korean patients from a phase 3 clinical trial investigating the efficacy and safety of ipragliflozin in patients with type 2 diabetes mellitus inadequately controlled with metformin.

METHODS

This multicenter, placebo-controlled, double-blind, parallel-group study was carried out between November 2011 and January 2013. Patients entered a 2-week placebo pretreatment period, followed by a 24-week treatment period with either ipragliflozin (50 mg/day) or placebo, while continuing metformin. Efficacy outcomes (glycosylated hemoglobin [HbA1c], fasting plasma glucose [FPG], and body weight) and safety outcomes (treatment-emergent adverse events [TEAEs]) were measured and compared between the two treatment groups for patients enrolled in all 18 study sites in Korea.

RESULTS

Eighty-two Korean patients received ipragliflozin (n=43) or placebo (n=39) during the study period. Mean changes in HbA1c levels from baseline to the end of treatment were -0.97% in the ipragliflozin group and -0.31% in the placebo group, with an adjusted between-group difference of -0.60% (P<0.001). Compared to placebo, FPG and body weight also decreased significantly (both P<0.001) from baseline after treatment in the ipragliflozin group, with between-group differences of -21.4 mg/dL and -1.53 kg, respectively. Decreased weight was the most common TEAE in the ipragliflozin group (7.0%); there were no reports of genital and urinary tract infection.

CONCLUSION

Ipragliflozin treatment in addition to metformin led to significant improvement in glycemic outcomes and reduction in body weight in Korean patients with type 2 diabetes mellitus, compared with metformin treatment alone; the safety profile was comparable in both groups.