Extracellular RNA transfer from non-malignant human cholangiocytes can promote cholangiocarcinoma growth.

Extracellular vesicles (EV) within the cellular secretome are emerging as modulators of pathological processes involved in tumor growth through their ability to transfer donor-derived RNA into recipient cells. While the effects of tumor and stromal cell EVs within the tumor microenvironment have been studied, less is known about the contributions of normal, nontransformed cells. We examined the impact of EVs within the cellular secretome from nonmalignant cells on transformed cell growth and behavior in cholangiocarcinoma cells. These effects were enhanced in the presence of the pro-fibrogenic mediator TGF-ß. We identified miR-195 as a TGF-ß responsive miRNA in normal cells that can be transferred via EV to tumor cells and regulate cell growth, invasion, and migration. The effects of miR-195 involve modulation of the epithelial-mesenchymal transition through direct effects on the transcription factor Snail. These studies provide in vitro and in vivo evidence for the impact of normal cellular secretome on transformed cell growth, show the importance of EV RNA transfer, and identify mechanisms of EV-mediated transfer of miRNA as a contributor to tumor development, which may provide new therapeutic opportunities for targeting human cholangiocarcinoma.

Receptor-Mediated Bioassay Reflects Dynamic Change of Glucose-Dependent Insulinotropic Polypeptide by Dipeptidyl Peptidase 4 Inhibitor Treatment in Subjects With Type 2 Diabetes.

Objective: We recently observed a greater increase in plasma levels of bioactive glucose-dependent insulinotropic polypeptide (GIP) than glucagon-like peptide 1 (GLP-1) using the receptor-mediated bioassays in the subjects with normal glycemic tolerance (NGT) treated with dipeptidyl peptidase 4 (DPP-4) inhibitors, which may be unappreciated using conventional enzyme-linked immunosorbent assays (ELISAs) during oral glucose tolerance test. Thus, we determined incretin levels in addition to glucagon level using the bioassays in type 2 diabetes mellitus (T2DM) subjects with or without treatment of DPP-4 inhibitor, to evaluate whether these assays can accurately measure bioactivity of these peptides. Methods: We performed single meal tolerance test (MTT) by using a cookie meal (carbohydrate 75.0 g, protein 8.0 g, fat 28.5 g) in the subjects with NGT (n = 9), the subjects with T2DM treated without DPP-4 inhibitor (n = 7) and the subjects with T2DM treated with DPP-4 inhibitor (n = 10). All subjects fasted for 10-12 h before the MTT, and blood samples were collected at 0, 30, 60, and 120 min. We used the cell lines stably cotransfected with human-form GIP, GLP-1 or glucagon receptor, and a cyclic adenosine monophosphate-inducible luciferase expression construct for the bioassays. We measured active GIP, active GLP-1, and glucagon by the bioassays. To evaluate the efficacy of bioassay, we measured identical samples via ELISA kits. Results: During the single MTT study, postprandial active GIP bioassay levels of T2DM with DPP-4 inhibitor treatment were drastically higher than those of NGT and T2DM without DPP-4 inhibitor, although the DPP-4 inhibitor-treated group showed moderate increase of active GIPELISA and active GLP-1 bioassay , while active GLP-1 bioassay levels of T2DM subjects without DPP-4 inhibitor were comparable to those of NGT subjects. During the serial MTT, administration of DPP-4 inhibitor significantly increased active GIP bioassay levels, but not active GLP-1 bioassay . Conclusions: In comparison to conventional ELISA, receptor-mediated bioassay reflects dynamic change of GIP polypeptide by DPP-4 inhibitor treatment in subjects with type 2 diabetes.

Establishment of novel specific assay for short-form glucose-dependent insulinotropic polypeptide and evaluation of its secretion in nondiabetic subjects.

The short-form glucose-dependent insulinotropic polypeptide (GIP) (1-30) is released from islet alpha cells and promotes insulin secretion in a paracrine manner in vitro. However, it is not well elucidated how GIP (1-30) is involved in glucose metabolism in vivo, since a specific assay system for GIP (1-30) has not yet been established. We first developed a sandwich enzyme-linked immunosorbent assay (ELISA) specific for GIP (1-30) by combining a novel antibody specific to the GIP (1-30) C terminus with the common antibody against GIP N terminus. Then, we explored cross-reactivities with incretins and glucagon-related peptides in this ELISA. GIP (1-30) amide, but not GIP (1-42), GLP-1, or glucagon increased absorbance in a dose-dependent manner. We next measured plasma GIP (1-30) concentrations in nondiabetic participants (ND) during a 75-g oral glucose tolerance test or cookie meal test (carbohydrates 75 g, lipids 28.5 g, proteins 8.5 g). Both glucose and cookie load increased GIP (1-30) concentrations in ND, but the increases were much lower than those of GIP (1-42). Furthermore, the DPP-4 inhibitor significantly increased GIP (1-30) concentrations similarly to GIP (1-42) in ND. In conclusion, we for the first time developed an ELISA specific for GIP (1-30) and revealed its secretion in ND.

Circulating extracellular vesicle-encapsulated HULC is a potential biomarker for human pancreatic cancer.

The role of long noncoding RNAs (lncRNAs) in the epithelial-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) is unclear. Some lncRNAs can be transferred by extracellular vesicles (EVs) and have potential as biomarkers. Here, we identify an lncRNA that could serve as a biomarker for PDAC and show the functional roles of the lncRNA. Expression profiling of lncRNAs revealed that highly upregulated in liver cancer (HULC) was highly expressed, and induced, by transforming growth factor-ß in PDAC cells and their EVs. Knockdown of HULC decreased PDAC cell invasion and migration by inhibiting the EMT. Thus, HULC could be transferred by EVs, and promote EMT, invasion, and migration in recipient PDAC cells. To assess the roles of HULC, PDAC cell xenografts in nude mice were established. Knockdown of HULC in PDAC cells implanted in mice inhibited tumor growth. Moreover, microRNA-133b suppressed PDAC cell invasion and migration by inhibiting the EMT through targeting HULC. Furthermore, serum samples were obtained from 20 PDAC and 22 intraductal papillary mucinous neoplasm (IPMN) patients, as well as 21 healthy individuals. Analysis of serum EV HULC expression by digital PCR showed that HULC expression was significantly increased in PDAC patients compared to healthy individuals or IPMN patients. Additionally, HULC showed good predictive performance for discriminating PDAC, suggesting that the analysis of EV-encapsulated HULC would contribute to the diagnosis for human PDAC. Extracellular vesicle-transported HULC promotes cell invasion and migration by inducing the EMT, and microRNA-133b suppresses the EMT by targeting HULC. Extracellular vesicle-encapsulated HULC could be a potential circulating biomarker for human PDAC.

Increment of plasma glucose by exogenous glucagon is associated with present and future renal function in type 2 diabetes:a retrospective study from glucagon stimulation test.

BACKGROUND: Glucagon stimulation test (GST) is often employed to assess the insulin reserve of the pancreatic beta cells in diabetic subjects. The clinical significance of the increment of plasma glucose (Δglucose) by exogenous glucagon during GST has not been elucidated. We investigated the relationship between Δglucose and clinical parameters including the liver and renal function in type 2 diabetic subjects, since we hypothesized that Δglucose is associated with the liver and renal function reflecting the capacity for gluconeogenesis in the organs. METHODS: A total of 209 subjects with type 2 diabetes who underwent GST during admission were included in this cross-sectional study. We defined the difference between plasma glucose at fasting and 6 min after intravenous injection of 1 mg glucagon as Δglucose. We assessed correlations between Δglucose and clinical parameters such as diabetic duration, BMI, HbA1c, beta cell function, serum free fatty acids (FFA) which is known to stimulate gluconeogenesis, liver function, the indices of liver function, renal function, and urinary albumin excretion (UAE). RESULTS: In correlation analysis, Δglucose positively correlated to FFA and estimated glomerular filtration rate (eGFR), but inversely to serum creatinine and cystatin C, although Δglucose showed no correlation with both liver function and the indices of residual liver function. Multiple regression analysis revealed that Δglucose was an independent determinant for the eGFR after 1 year, equally BMI, HbA1c, serum lipids, and UAE, which are known as the predictors for the development of chronic kidney disease. CONCLUSION: Our results suggest that Δglucose during GST might be related to gluconeogenesis in the kidney and could be the determinant of future renal function in type 2 diabetes.

N-Acetyl-seryl-aspartyl-lysyl-proline is a potential biomarker of renal function in normoalbuminuric diabetic patients with eGFR ≥ 30 ml/min/1.73 m2.

BACKGROUND: A biomarker, by which we can predict alterations of renal function in normoalbuminuric diabetic patients, is not available. Here, we report that endogenous anti-fibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) represents a potential biomarker to predict alterations in eGFR in normoalbuminuric diabetic patients. METHODS: We analyzed 21 normoalbuminuric diabetic patients with eGFR ≥ 30 ml/min/1.73 m2 and measured AcSDKP levels in first morning void urine. We divided patients into two groups based on the median values: low or high urinary AcSDKP groups (uAcSDKP/Crlow or uAcSDKP/Crhigh). At baseline, no significant differences in sex, age, HbA1c, BMI, serum creatinine levels, etc., were observed between the two groups. RESULTS: During ~ 4 years, the alteration in eGFR [ΔeGFRop (ΔeGFR observational periods)] was significantly stable in uAcSDKP/Crhigh group compared with uAcSDKP/Crlow group over time (P = 0.003, χ2 = 8.58). We also evaluated urine kidney injury molecule-1 (uKim-1) levels and found that ΔeGFRop was also stable in low uKim-1 group compared with high uKim-1 group over time (P = 0.004, χ2 = 8.38). Patients who fulfilled the criteria for both uAcSDKP/Crhigh and uKim-1low exhibited stable ΔeGFRop (P < 0.001, χ2 = 30.4) when compared to the remaining patients. Plasma AcSDKP (P = 0.015, χ2 = 5.94) and urine ß2-microglobulin (P = 0.038, χ2 = 4.31) also display weak but significant predictor of ΔeGFRop as well. CONCLUSION: AcSDKP represents a potentially useful biomarker to predict alterations in the renal function of patients with diabetes presenting normoalbuminuria.

Amplified Association Between Blood Pressure and Albuminuria in Overweight Patients With Biopsy-Proven Hypertensive Nephrosclerosis.

BACKGROUND: An overweight person is at high risk for hypertensive renal damage. The effect of weight on the association between systolic blood pressure (SBP) and albuminuria remains unknown in patients with histologically diagnosed hypertensive nephrosclerosis. METHODS: A total of 97 patients with biopsy-confirmed hypertensive nephrosclerosis were recruited from 13 centers throughout Japan. We examined the relationship between SBP and proteinuria among those who were overweight, which is defined as a body mass index ≥25 kg/m2, and those who were not. We examined the interaction of weight and SBP with albuminuria at baseline and with the changes in estimated glomerular filtration rate (eGFR) during the observational period. RESULTS: Our results included mean age (54 years old), blood pressure (138/80), eGFR (53 ml/min/1.73 m2), and urine albumin levels (0.2 g/day). SBP was significantly correlated with log-transformed urine albumin levels (r = 0.4, P = 0.01) in patients who were overweight (n = 38) compared with patients who were not overweight (n = 59). Multiple regression analysis revealed that the interaction between being overweight and SBP with respect to albuminuria was significantly correlated with the log-transformed urine albumin level (ß = 0.39, P = 0.047) and was independent of age, sex, and potential confounding factors. The interaction between weight and SBP ≥140 mm Hg was significantly associated with a greater decrease in eGFR in the following 3 years. CONCLUSIONS: Being overweight may enhance susceptibility to hypertensive glomerular damage and may eventually lead to renal progression in patients with hypertensive nephrosclerosis.

Secular changes in clinical manifestations of kidney disease among Japanese adults with type 2 diabetes from 1996 to 2014.

AIMS/INTRODUCTION: Diabetic kidney disease is characterized by increased albuminuria and/or a reduced glomerular filtration rate (GFR). We analyzed secular changes in the prevalence of albuminuria and reduced estimated GFR (eGFR) in Japanese patients with type 2 diabetes, and identified factors associated with these changes. MATERIALS AND METHODS: Using 1996, 2001, 2006 and 2014 cohort data from the Japanese serial cross-sectional studies conducted at Shiga University of Medical Science, secular changes in the prevalence of diabetic kidney disease (albuminuria and/or reduced eGFR), patient characteristics and their associations were analyzed. RESULTS: The prevalence of microalbuminuria and macroalbuminuria decreased over time, whereas the prevalence of moderately reduced eGFR (30-60 mL/min/1.73 m2 ) and severely reduced eGFR (<30 mL/min/1.73 m2 ) increased. Severely reduced eGFR was observed mainly in the patients with macroalbuminuria, regardless of year. Conversely, the prevalence of moderately reduced eGFR increased in the patients without macroalbuminuria. Both macroalbuminuria and moderately reduced eGFR without macroalbuminuria in the 2014 cohort were refractory to the recently recommended intensive therapy. Finally, we showed that obesity accompanied by vascular dysfunction was a risk factor for the development of albuminuria, and that age-dependent arterial stiffness was associated with reduced eGFR without macroalbuminuria in the 2014 cohort. CONCLUSIONS: During the past 20 years in Japan, the prevalence of albuminuria declined, whereas that of reduced eGFR increased. Additionally, obesity- and high age-related vascular damage seems to be associated with macroalbuminuria and reduced eGFR without macroalbuminuria, respectively.

Impacts of Diabetes and an SGLT2 Inhibitor on the Glomerular Number and Volume in db/db Mice, as Estimated by Synchrotron Radiation Micro-CT at SPring-8.

BACKGROUND: Recent large-scale clinical studies demonstrate that sodium-glucose cotransporter 2 (SGLT2) inhibitors protect the diabetic kidney. However, clinical and animal studies have not shown the changes of the total glomeruli in the whole kidney treated with SGLT2 inhibitors. METHODS: We performed computed tomography (CT) imaging on mice using synchrotron radiation to investigate the impact of luseogliflozin, a SGLT2 inhibitor, on the number and volume of glomeruli in the whole kidney. FINDINGS: We did not observe a significant difference in the total glomerular number (Nglom) among mice. Luseogliflozin redistributed the number of glomeruli in different regions, accompanied by the normalization of diabetes-augmented renal volume (Vkidney). Diabetic db/db mice had a larger glomerular volume in the mid-cortex than did control db/m mice, and luseogliflozin increased the glomerular volume in all renal cortical zones of the whole kidney in db/db mice. According to the multivariate regression analysis, hemoglobin A1c level was the most relevant determinant of Vkidney, not Nglom or mean glomerular volume (Vglom), indicating that hyperglycemia induced renal (tubular) hypertrophy, but not glomerular enlargement. Luseogliflozin increased hypoxia in the juxtamedullary region, sustained upregulated renal renin expression and plasma renin activity, and failed to decrease albuminuria by downregulating megalin in db/db mice. INTERPRETATION: Based on our findings, SGLT2 inhibitors may alter glomerular distribution and size in addition to their glucose-lowering effects, presumably by affecting oxygen metabolism and humoral factors. FUND: Funding for this research was provided by The Japan Society for the Promotion of Science, the Japan Diabetes Foundation, and Asahikawa Medical University.

Extracellular vesicle-encapsulated miR-30e suppresses cholangiocarcinoma cell invasion and migration via inhibiting epithelial-mesenchymal transition.

Early-staged cholangiocarcinoma (CCA) is difficult to diagnose due to its high potential for invasion and metastasis. Epithelial-mesenchymal transition (EMT) is induced by transforming growth factor-ß (TGF-ß) in a process thought to be important for invasion and metastasis in several cancers, including CCA. Although microRNAs (miRNAs) have been implicated in the pathogenesis of several malignancies, their roles to CCA are not clearly understood. Some miRNAs were reported to be included in extracellular vesicles (EVs) and transferred from their donor cells to other cells, modulating recipient cell behaviors. In this study, the involvement and functional roles of EV-contained miRNAs during EMT in human CCA were determined. Expression profiling identified a subset of miRNAs that were reduced by TGF-ß in CCA cells. Among these, miR-30e was highly downregulated by TGF-ß and predicted to target Snail, which is an EMT-inducible transcription factor. MiR-30e overexpression suppressed cell invasion and migration via inhibiting EMT, whereas miR-30e inhibition promoted EMT, cell invasion and migration. Moreover, miR-30e was enriched in EVs derived from CCA cells after miR-30e overexpression, and miR-30e intercellular transfer through EVs suppressed EMT, cell invasion and migration in recipient CCA cells. Together, our results suggest that EV-mediated miR-30e transfer could inhibit EMT via directly targeting Snail, which subsequently suppresses CCA cell invasion and migration. These findings provide several new insights into regulatory mechanisms of tumor invasion and metastasis in human CCA.

Pharmacokinetics and Pharmacodynamics of Luseogliflozin, a Selective SGLT2 Inhibitor, in Japanese Patients With Type 2 Diabetes With Mild to Severe Renal Impairment.

This open-label, parallel-group, multicenter study aimed to assess the effects of renal impairment on the pharmacokinetics, pharmacodynamics, and safety of luseogliflozin. A single 5-mg dose of luseogliflozin was administered to Japanese patients with type 2 diabetes mellitus in the following groups: G1, normal renal function; G2, mild renal impairment; G3a, mild to moderate impairment; G3b, moderate to severe impairment; G4, severe impairment, based on estimated glomerular filtration rate (eGFR; ≥90, 60-89, 45-59, 30-44, 15-29 mL/min/1.73 m2 , respectively). While luseogliflozin pharmacokinetics were similar for patients across all renal function groups, the increase in plasma concentration was slightly slower and maximum concentration was slightly reduced in the lower eGFR groups compared with the other groups. However, luseogliflozin pharmacodynamics were affected by the severity of renal impairment. Urinary glucose excretion (UGE) increased in all groups relative to baseline levels, but the degree of UGE increase was smaller in the lower eGFR groups. Moreover, plasma glucose AUC changes from baseline tended to be smaller in the lower eGFR groups. No clear trends were observed between eGFR and incidence, type, or severity of adverse events. Thus, luseogliflozin administration should be carefully considered, as patients with renal impairment may show an insufficient response to treatment.

JAK1/JAK2 inhibition by baricitinib in diabetic kidney disease: results from a Phase 2 randomized controlled clinical trial.

Background: Inflammation signaled by Janus kinases (JAKs) promotes progression of diabetic kidney disease (DKD). Baricitinib is an oral, reversible, selective inhibitor of JAK1 and JAK2. This study tested the efficacy of baricitinib versus placebo on albuminuria in adults with Type 2 diabetes at high risk for progressive DKD. Methods: In this Phase 2, double-blind, dose-ranging study, participants were randomized 1:1:1:1:1 to receive placebo or baricitinib (0.75 mg daily; 0.75 mg twice daily; 1.5 mg daily; or 4 mg daily), for 24 weeks followed by 4-8 weeks of washout. Results: Participants (N = 129) were 63±9.1 (mean±standard deviation) years of age, 27.1% (35/129) women and 11.6% (15/129) African-American race. Baseline hemoglobin A1c (HbA1c) was 7.3±1% and estimated glomerular filtration rate was 45.0±12.1 mL/min/1.73 m2 with first morning urine albumin-creatinine ratio (UACR) of 820 (407-1632) (median; interquartile range) mg/g. Baricitinib, 4 mg daily, decreased morning UACR by 41% at Week 24 compared with placebo (ratio to baseline 0.59, 95% confidence interval 0.38-0.93, P = 0.022). UACR was decreased at Weeks 12 and 24 and after 4-8 weeks of washout. Baricitinib 4 mg decreased inflammatory biomarkers over 24 weeks (urine C-X-C motif chemokine 10 and urine C-C motif ligand 2, plasma soluble tumor necrosis factor receptors 1 and 2, intercellular adhesion molecule 1 and serum amyloid A). The only adverse event rate that differed between groups was anemia at 32.0% (8/25) for baricitinib 4 mg daily versus 3.7% (1/27) for placebo. Conclusions: Baricitinib decreased albuminuria in participants with Type 2 diabetes and DKD. Further research is required to determine if baricitinib reduces DKD progression.

Nationwide multicentre kidney biopsy study of Japanese patients with type 2 diabetes.

Background: The clinical and pathologic manifestations of nephropathy due to type 2 diabetes are diverse, but large-scale pathologic studies with long-term observations are limited. Methods: Kidney biopsies and clinical data of 600 patients with type 2 diabetes were collected retrospectively from 13 centres across Japan. Thirteen pathologic findings (nine glomerular lesions, two interstitial lesions and two vascular lesions) were clearly defined and scored. Results: During the observation period, there were 304 composite kidney events [dialysis, doubling of creatinine or reduction of estimated glomerular filtration rate (eGFR) by half], 31 instances of chronic kidney disease (CKD) G5D, 76 cardiovascular events and 73 deaths. The mean observation period was 72.4 months. The distribution of CKD heat map categories for the 600 patients was 103 green or yellow, 149 orange and 348 red. Even in the cases in the green and yellow category, diffuse lesions (81.6%), polar vasculosis (42.6%) and subendothelial space widening (35.1%) were commonly detected. Cox proportional hazard analysis revealed that the presence of nodular lesions [hazard ratio (HR) 21.1, 95% confidence interval (CI) 5.3-84.6], exudative lesions (HR 5.1, 95% CI 1.3-20.3) and mesangiolysis (HR 7.6, 95% CI 2.0-28.8) in cases in the green and yellow category were associated with significantly great impact on composite kidney events after adjustment for clinical risk factors. Conclusions: This nationwide study on kidney biopsy of 600 cases with type 2 diabetes revealed that pathologic findings (presence of nodular lesions, exudative lesions and mesangiolysis) were strong predictors of kidney events in low-risk patients.

Nationwide multicenter kidney biopsy study of Japanese patients with hypertensive nephrosclerosis.

BACKGROUND: Nephrosclerosis is an increasingly reason for dialysis in Japan. However, kidney biopsy specimens for hypertensive nephrosclerosis are very limited; thus, the pathologic evaluation of hypertensive nephrosclerosis currently remains unclear. METHODS: Clinical and pathologic data of a total of 184 biopsy-confirmed hypertensive nephrosclerosis patients were collected from 13 centers throughout Japan. Seven pathological findings were assessed in this study. The outcomes of interest for this study were dialysis, composite kidney events, cardiovascular events, and all-cause mortality. RESULTS: The Green and Yellow (G&Y), Orange, and Red groups of the chronic kidney diseases (CKD) heat map contained 36, 57, and 91 cases, respectively. The mean observation period was 7.3 ± 5.2 (median, IQR; 6.1, 2.6-9.7) years. Global glomerulosclerosis (GScle), interstitial fibrosis and tubular atrophy (IFTA), arteriolar hyalinosis in Red exhibited higher scores than those in G&Y and Orange. The incidence rates of the composite kidney end points in 100 person-years for the G&Y, Orange, and Red groups were 1.42, 2.16, and 3.98, respectively. In the univariate Cox analysis for the composite kidney end points, GScle, IFTA and interstitial cell infiltration exhibited statistically significant high hazard ratios (1.18, 1.84, 1.69, respectively). However, after adjustment for clinical and medication data, the Red group in the CKD heat map category was risk factor for the composite kidney end points (HR 9.51). CONCLUSIONS: In summary, although pathologic findings had minor impacts on the prediction of composite outcomes in this study, the clinical stage of the CKD heat map is a good predictor of composite kidney events.

Expression of transcription factors in MEN1-associated pancreatic neuroendocrine tumors.

MEN1-associated pancreatic neuroendocrine tumors (pNETs) may potentially express distinct hormones, but the mechanism has not been elucidated. Transcription factors such as MafA and Pdx1 have been identified to lead to beta cell differentiation, while Arx and Brn4 to alpha cell differentiation in developing pancreas. We hypothesized those transcription factors are important to produce specific hormones in pNETs, similarly to developing pancreas, and examined the expression of transcription factors in a case of MEN1 who showed immunohistological coexistence of several hormone-producing pNETs including insulinoma. A 70-year-old woman was found to manifest hypoglycemia with non-suppressed insulinemia and hypercalcemia with elevated PTH level. She was diagnosed as MEN1 based on the manifestation of primary hyperparathyroidism, pituitary adenoma and insulinoma, with genetic variation of MEN1 gene. She had pylorus-preserving pancreaticoduodenectomy because CT scan and SACI test indicated that insulinoma was localized in the head of the pancreas. Histopathological finding was MEN1-associated NET, G1. Interestingly, immunohistological examination of the resected pancreas revealed that two insulinomas, a glucagon-positive NET and a multiple hormone-positive NET coexisted. Hence, we examined the expression of transcription factors immunohistochemically to elucidate the role of the transcription factors in MEN1-associated hormone-producing pNETs. We observed homogeneous expressions of MafA and Pdx1 in insulinomas and Arx in glucagon-positive NET, respectively. Moreover, multiple hormone-positive NETs expressed several transcription factors heterogeneously. Collectively, our results suggested that transcription factors could play important roles in the production of specific hormones in MEN1-associated pNETs, similar to islet differentiation. LEARNING POINTS: To date, it has been shown that different hormone-producing tumors coexist in MEN1-associated pNETs; however, the underlying mechanism of the hormone production in MEN1-associated pNETs has not been well elucidated.Although this case presented symptomatic hypoglycemia, several hormone-producing pNETs other than insulinoma also coexisted in the pancreas.Immunohistochemical analysis showed MafA and Pdx1 expressions distinctly in insulinoma, and Arx expression particularly in a glucagon-positive NET, while a multiple hormone-positive NET expressed MafA, Pdx1 and Arx.Collectively, clinicians should consider that several hormone-producing pNETs may coexist in a MEN1 case and examine both endocrinological and histopathological analysis of pNETs, regardless of whether symptoms related to the excess of hormones are observed or not.

Causes of death in Japanese patients with diabetes based on the results of a survey of 45,708 cases during 2001-2010: Report of the Committee on Causes of Death in Diabetes Mellitus.

The principal causes of death among 45,708 patients with diabetes (29,801 men and 15,907 women) who died in 241 hospitals throughout Japan during 2001-2010 were determined based on a survey of the hospital records. Autopsy had been conducted in 978 of the 45,708 cases. The most frequent cause of death was malignant neoplasia (38.3%), followed by, in order of descending frequency: infections (17.0%); and then vascular diseases (14.9%), including renal failure (3.5%), ischemic heart diseases (4.8%) and cerebrovascular diseases (6.6%). Diabetic coma associated with hyperglycemia with or without ketoacidosis accounted for only 0.6% of the deaths. In regard to the relationship between the age and cause of death in patients with diabetes, the incidence of death due to vascular diseases was higher in patients over the age of 30 or 40 years, and the 97.0% of the total death due to vascular diseases was observed in patients over the age of 50 years. The incidence of death due to infectious diseases, especially pneumonia, increased in an age-dependent fashion, and the 80.7% of the total death due to pneumonia was observed in patients over the age of 70 years. 'Poorer' glycemic control was associated with the reduced lifespan of patients with diabetes, especially of those with nephropathy. The average age at death in the survey population was 72.6 years. The lifespan was 1.6 years shorter in patients with 'poorer' glycemic control than in those with 'better' glycemic control. In patients with diabetes of less than 10 years' duration, the incidence of death due to macroangiopathy was higher than that due to nephropathy. Of the 45,708 patients with diabetes, 33.9% were on oral medication, 41.9% received insulin therapy and 18.8% were treated by diet alone. Among the patients in whom the cause of death was diabetic nephropathy, a high percentage, 53.7%, was on insulin therapy. The average age at death of the 45,708 patients with diabetes was 71.4 years in men and 75.1 years in women. However, the report of the Ministry of Health and Welfare of Japan in 2010 set the average lifespan of the Japanese at 79.6 years for men and 86.3 years for women. Thus, the average lifespan of patients with diabetes still appears to be shorter than that of the general population in Japan. However, the differences in lifespan between patients with diabetes and the general population were shorter than those in the former surveys.

Dipeptidyl peptidase-4 inhibitor treatment induces a greater increase in plasma levels of bioactive GIP than GLP-1 in non-diabetic subjects.

OBJECTIVE: Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) possess multiple bioactive isoforms that are rendered non-insulinotropic by the enzyme dipeptidyl peptidase-4 (DPP-4). Recently, some ELISA kits have been developed to specifically measure "active" GIP and GLP-1, but it is unclear if these kits can accurately quantify all bioactive forms. Therefore, it remains uncertain to what extent treatment with a DPP-4 inhibitor boosts levels of biologically active GIP and GLP-1. Thus, we evaluated our novel receptor-mediated incretin bioassays in comparison to commercially available ELISA kits using plasma samples from healthy subjects before and after DPP-4 inhibitor administration. METHODS: We utilized cell lines stably co-transfected with human GIP or GLP-1 receptors and a cAMP-inducible luciferase expression construct for the bioassays and commercially available ELISA kits. Assays were tested with synthetic GIP and GLP-1 receptor agonists and plasma samples collected from subjects during a 75 g oral glucose tolerance test (OGTT) performed before or following 3-day administration of a DPP-4 inhibitor. RESULTS: A GIP isoform GIP(1-30)NH2 increased luciferase activity similarly to GIP(1-42) in the GIP bioassay but was not detectable by either a total or active GIP ELISA kit. During an OGTT, total GIP levels measured by ELISA rapidly increased from 0 min to 15 min, subsequently reaching a peak of 59.2 ± 8.3 pmol/l at 120 min. In contrast, active GIP levels measured by the bioassay peaked at 15 min (43.4 ± 6.4 pmol/l) and then progressively diminished at all subsequent time points. Strikingly, at 15 min, active GIP levels as determined by the bioassay reached levels approximately 20-fold higher after the DPP-4 inhibitor treatment, while total and active GIP levels determined by ELISA were increased just 1.5 and 2.1-fold, respectively. In the absence of DPP-4 inhibition, total GLP-1 levels measured by ELISA gradually increased up to 90 min, reaching 23.5 ± 2.4 pmol/l, and active GLP-1 levels determined by the bioassay did not show any apparent peak. Following administration of a DPP-4 inhibitor there was an observable peak of active GLP-1 levels as determined by the bioassay at 15 min after oral glucose load, reaching 11.0 ± 0.62 pmol/l, 1.4-fold greater than levels obtained without DPP-4 inhibitor treatment. In contrast, total GLP-1 levels determined by ELISA were decreased after DPP-4 inhibitor treatment. CONCLUSION: Our results using bioassays indicate that there is a greater increase in plasma levels of bioactive GIP than GLP-1 in subjects treated with DPP-4 inhibitors, which may be unappreciated using conventional ELISAs.

Causes of death in Japanese patients with diabetes based on the results of a survey of 45,708 cases during 2001-2010: report of Committee on Causes of Death in Diabetes Mellitus.

The principal causes of death among 45,708 patients with diabetes (29,801 men and 15,907 women) who died in 241 hospitals throughout Japan during 2001-2010 were determined based on a survey of the hospital records. Autopsy had been conducted in 978 of the 45,708 cases. The most frequent cause of death was malignant neoplasia (38.3%), followed, in order of descending frequency, by infection (17.0%) and then vascular disease (14.9%), including renal failure (3.5%), ischemic heart disease (4.8%) and cerebrovascular disease (6.6%). Diabetic coma associated with hyperglycemia with or without ketoacidosis accounted for only 0.6% of the deaths. In regard to the relationship between the age and cause of death in patients with diabetes, the incidence of death due to vascular diseases was higher in patients over the age of 30 or 40 years, and 97.0% of the deaths due to vascular disease occurred in patients over the age of 50 years. The incidence of death due to infectious diseases, especially pneumonia, increased in an age-dependent fashion, and 80.7% of the deaths due to pneumonia occurred in patients over the age of 70 years. "Poorer" glycemic control was associated with the reduced lifespan of patients with diabetes, especially those with nephropathy. The average age at death in the survey population was 72.6 years. The lifespan was 1.6 years shorter in patients with "poorer" glycemic control than in those with "better" glycemic control. In patients with diabetes of less than 10 years' duration, the incidence of death due to macroangiopathy was higher than that due to nephropathy. Of the 45,708 patients with diabetes, 33.9% were on oral medication, 41.9% received insulin therapy, and 18.8% were treated by diet alone. Among the patients in whom the cause of death was diabetic nephropathy, a high percentage, 53.7%, were on insulin therapy. The average age at death of the 45,708 patients with diabetes was 71.4 years in men and 75.1 years in women. However, the report of the Ministry of Health and Welfare of Japan in 2010 set the average lifespan of the Japanese at 79.6 years for men and 86.3 years for women. Thus, the average lifespan of patients with diabetes still appears to be shorter than that of the general population in Japan. However, the difference in lifespan between patients with diabetes and the general population is smaller than found in previous surveys.

Patients with type 2 diabetes having higher glomerular filtration rate showed rapid renal function decline followed by impaired glomerular filtration rate: Japan Diabetes Complications Study.

AIMS: The Japan Diabetes Complications Study (JDCS), a nation-wide, multicenter, prospective study of patients with type 2 diabetes, reported that hemoglobin A1c (HbA1c), systolic blood pressure, and smoking were risk factors for the onset of macroalbuminuria. This study explored the risk factors for glomerular filtration rate (GFR) decline in the JDCS patients. METHODS: We examined the 1407 JDCS patients (667 women, mean age 59years, 974 normoalbuminuria, 433 microalbuminuria) whose urinary albumin-to-creatinine ratio (UACR) and estimated GFR (eGFR) were determined at baseline with an 8-year follow-up. We divided all the patients into four groups according to baseline eGFR: G1 (120≤eGFR), G2 (90≤eGFR<120), G3 (60≤eGFR<90), G4 (eGFR<60). RESULTS: The eGFRs in groups G1 and G2 decreased at follow-up compared to those at the baseline. The risk of annual eGFR decline rate≥3ml/min/1.73m2 (rapid decliners) increased as the baseline eGFR increased. Advanced age, high HbA1c, and UACR, or diabetic retinopathy at baseline were risk factors for the rapid decliners. Especially the G1 group had a significant risk for the rapid decliners. The frequency of the patients with GFR<60ml/min/1.73m2 at the follow-up amounted to 31.1% in the rapid decliners, which was higher than 12% in the non-rapid decliners. CONCLUSIONS: In normo- and microalbuminuric patients with type 2 diabetes, extra careful attention should be paid to patients with eGFR ≥120ml/min/1.73m2 to detect cases with rapidly decreased GFR under the normal range.

MicroRNA148b-3p inhibits mTORC1-dependent apoptosis in diabetes by repressing TNFR2 in proximal tubular cells.

Hypoxia causes proximal tubular cell damage in diabetes, even though proximal tubular cells have an adaptive system to combat hypoxia involving induction of hypoxia factor-1 (HIF-1) and inhibition of mechanistic target of rapamycin complex 1 (mTORC1). Here, we examined the interference effect of altered glucose and lipid metabolism on the hypoxia responses in proximal tubular cells. In culture, hypoxia alone induced HIF-1 and inhibited mTORC1, preventing death in proximal tubular cells. However, hypoxia with high glucose and palmitate increased mTORC1 activity and promoted apoptosis in proximal tubular cells, which was inhibited by pharmacological and genetic inactivation of mTORC1. Since inhibition of all mTORC1's physiological functions regulated by growth factors including insulin causes various adverse effects, we screened for a microRNA that can inhibit only pro-apoptotic effects of mTORC1 to discover a safe therapeutic target. This screen found microRNA-148b-3p was able to specifically inhibit mTORC1-dependent apoptosis in hypoxic proximal tubular cells exposed to high glucose and palmitate, without affecting insulin-dependent mTORC1 activation. Furthermore, tumor necrosis factor receptor (TNFR) 2 was the target of microRNA-148b-3p and its suppression inhibited apoptosis. Finally, enhanced apoptosis with TNFR2 overexpression was found in hypoxic and mTORC1-activated proximal tubular cells in diabetic rats. Thus, diabetes activated mTORC1 even in hypoxic proximal tubular cells, leading to apoptosis by reducing microRNA-148b-3p expression. Modulating this pathogenic pathway may be a novel therapy for proximal tubular cell damage in diabetes.