Exosomal miR-19a decreases insulin production by targeting Neurod1 in pancreatic cancer associated diabetes.

BACKGROUND: New onset diabetes mellitus demonstrates a roughly correlation with pancreatic cancer (PaC), which is unique in PaC and was named as PaC-induced DM, but the inner mechanism remains unclear. Exosomes mediate intercellular communication and bearing microRNAs might be direct constituent of effect in target cells. METHODS AND RESULTS: The isolated exosomes from PaC cells were used to treat pancreatic ß cells or the primary mice islets, and the glucose stimulated insulin secretions were measured. We validated the exosomal miR-19a from PaC cells to be an important mediator in the down regulation of insulin secretion by targeting Neurod1, the validated gene involved in insulin secretion, by using the quantitative real-time PCR, western blot, and promoter luciferase activity. The relative insulin, cAMP and Ca2+ expressions were also assayed to verify the inverse correlation between cancerous miR-19a and pancreatic islets Neurod1. CONCLUSIONS: Our study indicated that signal changes between cancer cells and ß cells via exosomes might be important in the pathogenesis of PaC-induced DM and supplemented the pathogenesis of PaC-induced DM and provide a possible access of PaC screening strategy.

Bone mineral density and trabecular bone score in Chinese subjects with sarcopenia.

BACKGROUND: As the general population is aging worldwide, the incidence of sarcopenia and osteoporosis is also rapidly increasing. Studies have found the link between sarcopenia and osteoporosis, but the relationship between sarcopenia and osteoporosis, especially bone microarchitecture, remains unclear. AIMS: To investigate the relationship between components of sarcopenia (muscle mass, handgrip strength, and gait speed) and components of osteoporosis [bone mass measured by bone mineral density (BMD) and bone microarchitecture measured by trabecular bone score (TBS)] in Chinese subjects. METHODS: 318 Chinese men and 203 Chinese women were included in our study. Muscle mass and BMD were measured by dual-energy X-ray absorptiometry (DXA). TBS iNsight® software was used for TBS. Jamar hydraulic hand dynamometer was used to assess muscle strength, and gait speed was used to assess physical performance. RESULTS: We found that the relative appendicular skeletal muscle mass (RASM) in both genders and handgrip strength in women correlated positively with TBS, RASM in men and handgrip strength in women correlated positively with BMDs. In the multiple linear regression model, RASM was positively associated with TBS in both genders, but no significant association was observed between RASM and BMDs. Interestingly, handgrip strength showed positive association with all evaluated BMDs and TBS in women, but not in men. Women with sarcopenia had lower TBS and BMDs at all evaluated sites. Men with sarcopenia had lower BMDs only at femur neck and total hip. CONCLUSIONS: The reduction of muscle mass and strength was significantly associated with decreased bone mass and deteriorated bone microarchitecture. More importantly, low muscle mass is an independent risk factor for bone microarchitecture in Chinese subjects.

Islet ß cell: An endocrine cell secreting miRNAs.

The pancreas is an important endocrine organ. Pancreatic beta (ß) cells secrete insulin to regulate the metabolism of glucose and maintain the stability of blood glucose. MicroRNAs (miRNAs), small (20-25 nt) non-coding RNA molecules, function in target gene silencing through post-transcriptional patterns, and multiple miRNAs regulate insulin secretion, insulin signaling pathways in pancreatic ß cells and islet activity. In recent years, it has been found that many types of cells can secrete regulatory miRNA, but whether islet cells can secrete miRNA has not been clarified yet. In this study, we detected miRNA expressions in cell culture medium of primary mouse islet cells and islet cell line MIN6. And we found that islet cells can selectively and actively secrete miRNAs, mainly through the way of exosome package, and that miRNA secretion profiling patterns vary according to different insulin secretion stimulating conditions (high Glucose, high Kcl, high Arginine and high Free fat acid (FFA)). Additionally, we found that these miRNAs secreted by islet cells can be transported and have gene-regulating functions on recipient tissue cells, such as liver and muscles. In conclusion, we find another secretory function of the islet ß cells: not only insulin, but also miRNAs.

Adipose tissue-targeted 11ß-hydroxysteroid dehydrogenase type 1 inhibitor protects against diet-induced obesity.

Current pharmacological treatments for obesity and metabolic syndrome have various limitations. Recently, adipose tissue 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) has been proposed as a novel therapeutic target for the treatment of obesity and metabolic syndrome. Nevertheless, there is no adipose tissue-targeted 11ß-HSD1 inhibitor available now. We sought to develop a new 11ß-HSD1 pharmacological inhibitor that homes specifically to the white adipose tissue and aimed to investigate whether adipose tissue-targeted 11ß-HSD1 inhibitor might decrease body weight gain and improve glucose tolerance in diet-induced obesity mice. BVT.2733, an 11ß-HSD1 selective inhibitor was connected with a peptide CKGGRAKDC that homes to white fat vasculature. CKGGRAKDC-BVT.2733 (T-BVT) or an equimolar mixture of CKGGRAKDC and BVT.2733 (NT-BVT) was given to diet-induced obesity mice for two weeks through subcutaneous injection. T-BVT decreased body weight gain, improved glucose tolerance and decreased adipocyte size compared with vehicle treated mice. In adipose tissue T-BVT administration significantly increased adiponectin, vaspin mRNA levels; In liver T-BVT administration decreased the mRNA level of phosphoenolpyruvate carboxykinase (PEPCK), increased the mRNA levels of mitochondrial carnitine palmi-toyltransferase-I (mCPT-I) and peroxisome proliferator-activated receptorα(PPARα). No significant differences in adipocyte size and hepatic gene expression were observed after treatment with NT-BVT compared with vehicle treated mice, though NT-BVT also decreased body weight gain, improved glucose tolerance, and increased uncoupling protein-2 (UCP-2) mRNA levels in muscle. These results suggest that an adipose tissue-targeted pharmacological inhibitor of 11ß-HSD1 may prove to be a new approach for the treatment of obesity and metabolic syndrome.

Pancreatic cancer-derived exosomal microRNA-19a induces ß-cell dysfunction by targeting ADCY1 and EPAC2.

New-onset diabetes mellitus has a rough correlation with pancreatic cancer (PaC), but the underlying mechanism remains unclear. This study aimed to explore the exosomal microRNAs and their potential role in PaC-induced ß-cell dysfunction. The pancreatic ß cells were treated with isolated exosomes from PaC cell lines, SW1990 and BxPC-3, before measuring the glucose-stimulated insulin secretion (GSIS), validating that SW1990 and BxPC-3 might disrupt GSIS of both ß cell line MIN6 and primary mouse pancreatic islets. The difference in expression profiles between exosomes and exosome-free medium of PaC cell lines was further defined, revealing that miR-19a secreted by PaC cells might be an important signaling molecule in this process. Furthermore, adenylyl cyclase 1 (Adcy1) and exchange protein directly activated by cAMP 2 (Epac2) were verified as the direct targets of exogenous miR-19a, which was involved in insulin secretion. These results indicated that exosomes might be an important mediator in the pathogenesis of PaC-DM, and miR-19a might be the effector molecule. The findings shed light on the pathogenesis of PaC-DM.

The correlation of muscle thickness and pennation angle assessed by ultrasound with sarcopenia in elderly Chinese community dwellers.

Background: Sarcopenia is typically defined as the loss of muscle mass, strength and low physical performance with aging. Ultrasound is a safe and easy method for evaluating muscle mass and quality by muscle thickness (MT) and pennation angle (PA), respectively. Although the positive correlations between MT and muscle mass and handgrip strength were observed, the relationship between MT, PA and physical performance remains unclear. Purpose: This study aimed to investigate the correlation of aforementioned ultrasound parameters with muscle mass, muscle strength and physical performance and explore the utility of ultrasound in predicting sarcopenia. Patients and methods: A total of 265 elderly Chinese community dwellers were included. MT of both forearm and lower leg as well as PA of gastrocnemius was assessed by ultrasound. Muscle mass was assessed by dual-energy X-ray absorptiometry. Muscle strength was measured by a Jamar hand dynamometer. Physical performance was assessed by the Short Physical Performance Battery (SPPB). Results: Anterior radial MT in men and regional MTs except posterior fibula in women were negatively correlated with the age. No significant correlation was observed between PA and the age in both genders. Posterior tibial MT and posterior fibula MT were positively correlated with the relative appendicular skeletal muscle mass in men and women, respectively. Anterior ulnar MT was positively correlated with grip strength in both genders. Moreover, gastrocnemius medialis PA showed a positive association with gait speed and SPPB in women but not in men. Conclusion: A combination of posterior fibula MT, anterior ulnar MT and gastrocnemius medialis PA measured by muscle ultrasound is helpful for the assessment of sarcopenia in Chinese elderly women. In addition, a combination of posterior tibial MT and anterior ulnar MT measured by muscle ultrasound is helpful for the assessment of sarcopenia in Chinese elderly men.

Altered Serum MicroRNA Profile May Serve as an Auxiliary Tool for Discriminating Aggressive Thyroid Carcinoma from Nonaggressive Thyroid Cancer and Benign Thyroid Nodules.

Thyroid cancers are the most common malignancy of the endocrine system; however, there is no reliable blood biomarkers for thyroid cancer diagnosis and even for aggressive and nonaggressive thyroid cancers as well as benign nodule discrimination. The present study is aimed at evaluating whether circulating microRNA (miRNA) can differentiate aggressive and nonaggressive thyroid cancer from benign thyroid nodules. In this study, we performed a multiphase, case-control study to screen serum miRNA expression profile in 100 patients with papillary thyroid cancer (PTC), 15 patients with aggressive medullary thyroid carcinoma (MTC), 91 patients with benign nodules, and 89 healthy controls using TaqMan low-density array followed by extensive reverse transcription quantitative real-time PCR validation. The results showed that the serum levels of miR-222-3p, miR-17-5p, and miR-451a were markedly increased, while miR-146a-5p, miR-132-3p, and miR-183-3p were significantly decreased in the PTC and benign nodule groups compared with the control group. There was no difference in the miRNA expression profile between the PTC group and the benign nodule group. Nevertheless, the serum levels of miR-222-3p and miR-17-5p were significantly increased in the MTC group than the benign nodule and control group. Moreover, receiver operating characteristic curve analyses demonstrated that the 2 miRNAs and their panel can accurately discriminate MTC from the benign nodule group and healthy controls. These findings indicated that the altered circulating miRNAs may discriminate PTC and benign thyroid nodules from controls, and serum miR-222-3p and miR-17-5p have the potential to serve as auxiliary tools for diagnosing more aggressive thyroid carcinomas, such as MTC.

Assessment of Fat distribution and Bone quality with Trabecular Bone Score (TBS) in Healthy Chinese Men.

Whether fat is beneficial or detrimental to bones is still controversial, which may be due to inequivalence of the fat mass. Our objective is to define the effect of body fat and its distribution on bone quality in healthy Chinese men. A total of 228 men, aged from 38 to 89 years, were recruited. BMD, trabecular bone score (TBS), and body fat distribution were measured by dual-energy X-ray absorptiometry. Subcutaneous and visceral fat were assessed by MRI. In the Pearson correlation analysis, lumbar spine BMD exhibited positive associations with total and all regional fat depots, regardless of the fat distribution. However, the correlation disappeared with adjusted covariables of age, BMI, HDL-C, and HbA1c%. TBS was negatively correlated with fat mass. In multiple linear regression models, android fat (and not gynoid, trunk, or limbs fat) showed significant inverse association with TBS (ß = -0.611, P < 0.001). Furthermore, visceral fat was described as a pathogenic fat harmful to TBS, even after adjusting for age and BMI (ß = -0.280, P = 0.017). Our findings suggested that body fat mass, especially android fat and visceral fat, may have negative effects on bone microstructure; whereas body fat mass contributes to BMD through mechanical loading.

Increased serum microRNAs are closely associated with the presence of microvascular complications in type 2 diabetes mellitus.

Circulating microRNAs (miRNAs) are emerging biomarkers for type 2 diabetes mellitus (T2DM). However, a comprehensive characterization of the serum miRNA profile in patients with T2DM-associated microvascular disease (T2DMC) has rarely been reported. In this study, we obtained serum samples from 184 T2DM patients (92 with microvascular complications and 92 free of complications) and 92 age/gender-matched controls. The levels of 754 miRNAs were initially analyzed using a TaqMan Low Density Array (TLDA) in three pooled samples from 24 T2DM patients, 24 T2DMC patients and 24 controls. Markedly upregulated miRNAs in the patients' groups were subsequently validated individually by quantitative reverse-transcription PCR (RT-qPCR) in the same samples used for TLDA and further confirmed in another larger cohort consisting of 68 patients with T2DM, 68 patients with T2DMC and 68 controls. Five miRNAs were significantly upregulated in T2DM patients (p < 0.05) including miR-661, miR-571, miR-770-5p, miR-892b and miR-1303. Moreover, the levels of the five miRNAs were higher in patients with complications than in those without complications. Regression analyses revealed the five miRNAs were significantly correlated with microvascular complications (p < 0.05). The five serum miRNAs identified in our study hold potential as auxiliary biomarkers and novel risk factors for T2DM-associated microvascular complications.

Essential roles of 11ß-HSD1 in regulating brown adipocyte function.

Brown adipose tissue (BAT) increases energy expenditure and is an attractive therapeutic target for obesity. 11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1), an amplifier of local glucocorticoid activity, has been shown to modulate white adipose tissue (WAT) metabolism and function. In this study, we investigated the roles of 11ß-HSD1 in regulating BAT function. We observed a significant increase in the expression of BAT-specific genes, including UCP1, Cidea, Cox7a1, and Cox8b, in BVT.2733 (a selective inhibitor of 11ß-HSD1)-treated and 11ß-HSD1-deficient primary brown adipocytes of mice. By contrast, a remarkable decrease in BAT-specific gene expression was detected in brown adipocytes when 11ß-HSD1 was overexpressed, which effect was reversed by BVT.2733 treatment. Consistent with the in vitro results, expression of a range of genes related to brown fat function in high-fat diet-fed mice treated with BVT.2733. Our results indicate that 11ß-HSD1 acts as a vital regulator that controls the expression of genes related to brown fat function and as such may become a potential target in preventing obesity.

BVT.2733, a selective 11ß-hydroxysteroid dehydrogenase type 1 inhibitor, attenuates obesity and inflammation in diet-induced obese mice.

BACKGROUND: Inhibition of 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is being pursued as a new therapeutic approach for the treatment of obesity and metabolic syndrome. Therefore, there is an urgent need to determine the effect of 11ß-HSD1 inhibitor, which suppresses glucocorticoid action, on adipose tissue inflammation. The purpose of the present study was to examine the effect of BVT.2733, a selective 11ß-HSD1 inhibitor, on expression of pro-inflammatory mediators and macrophage infiltration in adipose tissue in C57BL/6J mice. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6J mice were fed with a normal chow diet (NC) or high fat diet (HFD). HFD treated mice were then administrated with BVT.2733 (HFD+BVT) or vehicle (HFD) for four weeks. Mice receiving BVT.2733 treatment exhibited decreased body weight and enhanced glucose tolerance and insulin sensitivity compared to control mice. BVT.2733 also down-regulated the expression of inflammation-related genes including monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α) and the number of infiltrated macrophages within the adipose tissue in vivo. Pharmacological inhibition of 11ß-HSD1 and RNA interference against 11ß-HSD1 reduced the mRNA levels of MCP-1 and interleukin-6 (IL-6) in cultured J774A.1 macrophages and 3T3-L1 preadipocyte in vitro. CONCLUSIONS/SIGNIFICANCE: These results suggest that BVT.2733 treatment could not only decrease body weight and improve metabolic homeostasis, but also suppress the inflammation of adipose tissue in diet-induced obese mice. 11ß-HSD1 may be a very promising therapeutic target for obesity and associated disease.

Correlation of obesity and osteoporosis: Effect of free fatty acids on bone marrow-derived mesenchymal stem cell differentiation.

Studies on the relationship between obesity and bone have recently become widespread. The aim of this study was to investigate the effect of obesity on bone, utilizing a diet-induced obese mouse model, and to explore the role of free fatty acids (FFAs) in the osteogenesis/adipogenesis of mouse bone marrow-derived mesenchymal stem cells (BMSCs). An obese mouse model was established by a high-fat diet (HFD). Proximal femurs were collected at sacrifice, and bone mineral density (BMD) in the proximal femurs was measured by dual-energy X-ray absorptiometry. Bone histomorphometry was performed using undecalcified sections of the proximal femurs. The effect of obesity on the differentiation of mouse BMSCs was assessed by colony formation assays and gene expression analysis. In vitro, various osteogenic and adipogenic genes were determined by real-time quantitative PCR in mouse BMSCs after exposure to conditioned medium (CM) from FFA-treated 3T3-L1 adipocytes. Western blotting was further performed to analyze the representative protein expression of PPARγ and Runx2. BMD and trabecular thickness were significantly greater in the HFD mice than in the control mice. CFU-osteo assay showed significantly increased osteogenesis of BMSCs. The mRNA level of Runx2 was significantly higher, while PPARγ and Pref-1 were significantly lower in BMSCs from the HFD mice compared to the control mice. In mouse BMSCs, the Sox9 and Runx2 genes were significantly up-regulated after exposure to CM from FFA-treated adipocytes, while PPARγ and CEBP-α were significantly down-regulated. Osteogenesis was significantly increased, while adipogenesis was significantly decreased. In conclusion, HFD-induced obesity may play a protective role in bone formation by concomitantly promoting osteogenic and suppressing adipogenic differentiation of BMSCs through factors secreted by FFA-treated adipocytes.