Profiling of Unfolded Protein Response Markers and Effect of IRE1α-specific Inhibitor in Pituitary Neuroendocrine Tumor.

CONTEXT: Inositol-requiring enzyme 1α (IRE1α) and PKR-like ER kinase (PERK), which are endoplasmic reticulum (ER) membrane proteins, regulate the unfolded protein response (UPR). These molecules have recently gained attention as a novel therapeutic target in secretory tumors. The roles of the UPR in pituitary neuroendocrine tumors (PitNETs) are unclear. OBJECTIVE: To clarify UPR profiling of PitNETs and to investigate the effect of pharmacological modulation of UPR by KIRA8, a newly developed IRE1α-specific inhibitor. METHODS: In 131 patients with PitNETs, we evaluated RNA expression of UPR markers in PitNETs and their clinical phenotypes. Using GH3 cells, we examined the effects of KIRA8 and its combination with octreotide on UPR profiling, cell growth, and apoptosis. RESULTS: Cytoprotective adaptive-UPR (A-UPR) markers were more increased in functioning PitNETs (FPitNETs, n = 112) than in nonfunctioning PitNETs (NFPitNETs, n = 19), while there was no difference in proapoptotic terminal-UPR (T-UPR) markers. Similarly, overt somatotroph tumors (STs, acromegaly, n = 11) increased A-UPR compared with silent STs (n = 10). In STs, serum IGF-1 levels were inversely correlated with Txnip mRNA expression, a representative T-UPR marker. KIRA8 inhibited cell growth and facilitated apoptosis in GH3 cells with increased expressions of T-UPR markers, which was enhanced by the combination with octreotide. Octreotide increased mRNA expression of Txnip and Chop, but decreased spliced Xbp1 under ER stress. Octreotide is suggested to inhibit activation of IRE1α but to reciprocally induce T-UPR under PERK. CONCLUSION: UPR markers in FPitNETs are implicated as dominant A-UPR but blunted T-UPR. KIRA8, enhanced with octreotide, unbalances the UPR, leading to antitumor effects. Targeting IRE1α may provide a novel strategy to treat PitNETs.

Renoprotective potential of concomittant medications with SGLT2 inhibitors and renin-angiotensin system inhibitors in diabetic nephropathy without albuminuria: a retrospective cohort study.

The renal protective effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors and renin-angiotensin system (RAS) inhibitors on diabetic nephropathy without albuminuria have not been fully investigated. This retrospective cohort study focused on patients with type 2 diabetes mellitus who had a baseline estimated glomerular filtration rate (eGFR) of > 30 mL/min/1.73 m2, and a urinary albumin-to-creatinine ratio < 30 mg/gCr. After propensity score matching, using covariates such as age, body mass index, systolic blood pressure, hemoglobin A1c levels, and prescription history of RAS inhibitors, we established a cohort of 58 patients: the SGLT2 inhibitor group (n = 28) and the control group (n = 28). In this cohort, we compared the annual eGFR decline rate between the two groups. The SGLT2 inhibitor group exhibited a significantly smaller eGFR change than the control group (- 1.15 vs. - 2.18 mL/min/1.73 m2/year). Within the SGLT2 inhibitor group, patients prescribed RAS inhibitors had demonstrated an even smaller eGFR change (- 0.70 mL/min/1.73 m2/year). In conclusion, SGLT2 inhibitors also have safeguarding effects in the stage of diabetic nephropathy without albuminuria, and the combined use of a SGLT2 inhibitor and a RAS inhibitor appears to be more effective than the single use of each.

Allosteric Inhibition of c-Abl to Induce Unfolded Protein Response and Cell Death in Multiple Myeloma.

Endoplasmic reticulum stress activates inositol-requiring enzyme 1α (IRE1α) and protein kinase, R-like endoplasmic reticulum kinase (PERK), the two principal regulators of the unfolded protein response (UPR). In multiple myeloma, adaptive IRE1α signaling is predominantly activated and regulates cell fate along with PERK. Recently, we demonstrated that GNF-2, an allosteric c-Abl inhibitor, rheostatically enhanced IRE1α activity and induced apoptosis through c-Abl conformational changes in pancreatic ß cells. Herein, we analyzed whether the pharmacological modulation of c-Abl conformation resulted in anti-myeloma effects. First, we investigated the effects of GNF-2 on IRE1α activity and cell fate, followed by an investigation of the anti-myeloma effects of asciminib, a new allosteric c-Abl inhibitor. Finally, we performed RNA sequencing to characterize the signaling profiles of asciminib. We observed that both GNF-2 and asciminib decreased cell viability and induced XBP1 mRNA splicing in primary human myeloma cells and myeloma cell lines. RNA sequencing identified the induction of UPR- and apoptosis-related genes by asciminib. Asciminib re-localized c-Abl to the endoplasmic reticulum, and its combination with a specific IRE1α inhibitor, KIRA8, enhanced cell death with the reciprocal induction of CHOP mRNA expression. Together, the allosteric inhibition of c-Abl-activated UPR with anti-myeloma effects; this could be a novel therapeutic target for multiple myeloma.

Spatial and transcriptional heterogeneity of pancreatic beta cell neogenesis revealed by a time-resolved reporter system.

AIMS/HYPOTHESIS: While pancreatic beta cells have been shown to originate from endocrine progenitors in ductal regions, it remains unclear precisely where beta cells emerge from and which transcripts define newborn beta cells. We therefore investigated characteristics of newborn beta cells extracted by a time-resolved reporter system. METHODS: We established a mouse model, 'Ins1-GFP; Timer', which provides spatial information during beta cell neogenesis with high temporal resolution. Single-cell RNA-sequencing (scRNA-seq) was performed on mouse beta cells sorted by fluorescent reporter to uncover transcriptomic profiles of newborn beta cells. scRNA-seq of human embryonic stem cell (hESC)-derived beta-like cells was also performed to compare newborn beta cell features between mouse and human. RESULTS: Fluorescence imaging of Ins1-GFP; Timer mouse pancreas successfully dissected newly generated beta cells as green fluorescence-dominant cells. This reporter system revealed that, as expected, some newborn beta cells arise close to the ducts (ßduct); unexpectedly, the others arise away from the ducts and adjacent to blood vessels (ßvessel). Single-cell transcriptomic analyses demonstrated five distinct populations among newborn beta cells, confirming spatial heterogeneity of beta cell neogenesis such as high probability of glucagon-positive ßduct, musculoaponeurotic fibrosarcoma oncogene family B (MafB)-positive ßduct and musculoaponeurotic fibrosarcoma oncogene family A (MafA)-positive ßvessel cells. Comparative analysis with scRNA-seq data of mouse newborn beta cells and hESC-derived beta-like cells uncovered transcriptional similarity between mouse and human beta cell neogenesis including microsomal glutathione S-transferase 1 (MGST1)- and synaptotagmin 13 (SYT13)-highly-expressing state. CONCLUSIONS/INTERPRETATION: The combination of time-resolved histological imaging with single-cell transcriptional mapping demonstrated novel features of spatial and transcriptional heterogeneity in beta cell neogenesis, which will lead to a better understanding of beta cell differentiation for future cell therapy. DATA AVAILABILITY: Raw and processed single-cell RNA-sequencing data for this study has been deposited in the Gene Expression Omnibus under accession number GSE155742.

Hypopituitarism and cranial nerve involvement mimicking Tolosa-Hunt syndrome as the initially presenting feature of diffuse large B-cell lymphoma: a case report.

BACKGROUND: Early diagnosis of lymphoma involving the central nervous system is sometimes difficult but emergent to avoid the delay of therapeutic initiation. Pituitary insufficiencies are usually associated with lymphoma in the pituitary gland. There have been no cases of lymphoma originating from extra pituitary gland with hypopituitarism that simultaneously presenting unilateral upper cranial nerve palsies and ophthalmalgia. These symptoms are mostly caused by neoplastic involvement of the skull base or benign diseases such as Tolosa-Hunt syndrome (THS). We report a case of lymphoma with unique clinical courses initially presenting hypopituitarism and symptoms mimicking THS with a mass in sphenoidal and cavernous sinuses accompanying sphenoidal bone erosion. CASE PRESENTATION: A 71-year-old woman visited our hospital with left ophthalmalgia, ptosis, and diplopia. Neurological findings revealed left oculomotor, trochlear and abducent nerve palsies. Endocrine tests indicated partial hypopituitarism. Initial CT and MRI revealed that a mass in sphenoidal and cavernous sinuses had invaded the sella with osteolysis of the sphenoid bone. At around four weeks, almost all the symptoms of cranial nerve palsies were relieved. Seven weeks later, she had a high fever and cervical lymph node (CLN) swellings. CLN biopsy revealed CD20-positive B-cells. She was diagnosed with diffuse large B-cell lymphoma (DLBCL). 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) revealed elevated uptake at the erosion lesion of the sphenoidal bone, but not the pituitary gland. After chemotherapy, all the symptoms related to systemic lymphoma were relieved, but partial hypopituitarism remained. The mass in sphenoidal and cavernous sinuses and elevated uptake by PET/CT were dissolved. CONCLUSION: This case of DLBCL had a unique clinical course; initial presentation of hypopituitarism and symptoms mimicking THS. There was also rare demonstration of mass lesions related to DLBCL in the sphenoidal and cavernous sinuses compressing the pituitary gland through an eroded area of the sphenoidal bone. It should be clinically cautioned that DLBCL can be associated with erosion of the sphenoidal bone and cause both hypopituitarism and THS-mimicking symptoms.

Reduced Fat Taste Sensitivity in Obese Japanese Patients and Its Recovery after a Short-Term Weight Loss Program.

Fat taste has recently attracted attention as the 'sixth taste.' However, the relationship between fat and sweet taste in Japanese obesity has not yet been examined, and no reports have ascertained whether improvement of fat taste can be obtained by weight loss. Patients were recruited into obesity group (BMI≥30 kg/m2; n=15) or control group (BMI<25 kg/m2; n=11). They answered a questionnaire on smoking, eating behavior, lifestyle, and food frequency, and their taste thresholds were measured (fat, umami, and sweet). The obesity group was tested twice (on admission and before discharge). They showed several eating behavior abnormalities, higher total energy intake, and less physical activity. There were some gender differences: physical inactivity was more prominent in females, and high total energy intake in males, which correlates with fat taste rank. Fat taste rank was significantly higher in obesity group, whereas taste rank of umami and sweet were not significantly different. Gender-specific analysis of fat taste rank revealed only male obesity showed significant difference. Reduced sensitivity of fat may be specific to male gender or obesity by overeating, but not by physical inactivity. Multiple logistic regression analysis revealed that fat taste was a factor relevant to obesity. Fat taste significantly improved after a weight loss program, with average duration of 11.3 d. Japanese obese people, especially males and those who are obese by overeating, have reduced sensitivity to fat taste. This can be recovered by even a short-term weight loss program.

Characterisation of Ppy-lineage cells clarifies the functional heterogeneity of pancreatic beta cells in mice.

AIMS/HYPOTHESIS: Pancreatic polypeptide (PP) cells, which secrete PP (encoded by the Ppy gene), are a minor population of pancreatic endocrine cells. Although it has been reported that the loss of beta cell identity might be associated with beta-to-PP cell-fate conversion, at present, little is known regarding the characteristics of Ppy-lineage cells. METHODS: We used Ppy-Cre driver mice and a PP-specific monoclonal antibody to investigate the association between Ppy-lineage cells and beta cells. The molecular profiles of endocrine cells were investigated by single-cell transcriptome analysis and the glucose responsiveness of beta cells was assessed by Ca2+ imaging. Diabetic conditions were experimentally induced in mice by either streptozotocin or diphtheria toxin. RESULTS: Ppy-lineage cells were found to contribute to the four major types of endocrine cells, including beta cells. Ppy-lineage beta cells are a minor subpopulation, accounting for 12-15% of total beta cells, and are mostly (81.2%) localised at the islet periphery. Unbiased single-cell analysis with a Ppy-lineage tracer demonstrated that beta cells are composed of seven clusters, which are categorised into two groups (i.e. Ppy-lineage and non-Ppy-lineage beta cells). These subpopulations of beta cells demonstrated distinct characteristics regarding their functionality and gene expression profiles. Ppy-lineage beta cells had a reduced glucose-stimulated Ca2+ signalling response and were increased in number in experimental diabetes models. CONCLUSIONS/INTERPRETATION: Our results indicate that an unexpected degree of beta cell heterogeneity is defined by Ppy gene activation, providing valuable insight into the homeostatic regulation of pancreatic islets and future therapeutic strategies against diabetes. DATA AVAILABILITY: The single-cell RNA sequence (scRNA-seq) analysis datasets generated in this study have been deposited in the Gene Expression Omnibus (GEO) under the accession number GSE166164 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE166164 ).

Association of abdominal obesity with crossing capillaries in the finger nailfold in type 2 diabetes mellitus.

AIM: Increased crossing of finger nailfold capillaries could be a novel visual marker of early microvascular damage among type 2 diabetes mellitus patients. Although abdominal obesity is an important driver of early microvascular damage, its association with an increase in the percentage of crossing capillaries remains uncertain. We investigated the association between abdominal obesity and an increase in the percentage of crossing capillaries in the finger nailfold in patients with type 2 diabetes mellitus. METHODS: This cross-sectional study enrolled 123 type 2 diabetes mellitus patients (age 40-75 years) who visited the outpatient diabetic clinic at Osaka University Hospital between May and October 2019. Abdominal obesity was defined as a waist circumference ≥ 90 cm in women and ≥ 85 cm in men. Capillary morphology was assessed by nailfold capillaroscopy based on the simple capillaroscopic definitions of the European League Against Rheumatism Study Group. The association between abdominal obesity and a high percentage of crossing capillaries in the finger nailfold (defined as the highest tertile of crossing capillaries) was analyzed using multivariable logistic regression. RESULTS: After adjusting for age, sex, smoking status, regular exercise, duration of diabetes, glycated hemoglobin, hypertension, and dyslipidemia, abdominal obesity was significantly associated with a high percentage of crossing capillaries (multivariable-adjusted odds ratios [95% confidence interval] = 2.70 [1.05-6.90], p = 0.038). CONCLUSIONS: Abdominal obesity may play an important role in the increase in the percentage of crossing capillaries in the finger nailfold in patients with type 2 diabetes mellitus.

Evaluation of change in metabolome caused by comprehensive diabetes treatment: A prospective observational study of diabetes inpatients with gas chromatography/mass spectrometry-based non-target metabolomic analysis.

AIMS/INTRODUCTION: Diabetes patients develop a variety of metabolic abnormalities in addition to hyperglycemia. However, details regarding change in various metabolites after comprehensive diabetes treatment remain unknown. This study aimed to identify the short-term change in metabolome in inpatients who were subject to comprehensive diabetes treatment, using gas chromatography/mass spectrometry-based non-target metabolomics techniques. MATERIALS AND METHODS: Participants of the present study were randomly recruited from the patients with type 2 diabetes hospitalized due to problems with glycemic control (n = 31) and volunteers without diabetes (n = 30), both of whom were aged between 20 and 75 years. A metabolomic analysis of fasting plasma samples on the 2nd (pre-treatment) and 16th hospital (post-treatment) day with gas chromatography/mass spectrometry using a multiple reaction monitoring mode was carried out. RESULTS: A principal component analysis showed that metabolome of fasting plasma was different between individuals with and without diabetes. The metabolome of fasting plasma in diabetes patients after treatment was different from that of pre-treatment, as well as individuals without diabetes. Many amino acids (proline, glycine, serine, threonine, methionine, pyroglutamic acid, glutamine and lysine) were significantly increased by >10% after administering the inpatient diabetes treatment. A hierarchical clustering analysis showed that in the case of patients with markedly decreased monosaccharide levels and increased 1,5-anhydroglucitol, the levels of amino acids increased more significantly. CONCLUSIONS: After a 2-week comprehensive treatment, the plasma levels of various amino acids increased in conjunction with the reduction in monosaccharide levels in poorly controlled type 2 diabetes patients.

Association of obesity, diabetes, and physical frailty with dental and tongue-lip motor dysfunctions in patients with metabolic disease.

OBJECTIVE: This study aimed to reveal the clinical features associated with decreased dental (or shearing/crushing) and tongue-lip motor functions in patients with metabolic diseases. METHODS: One thousand patients with metabolic diseases including diabetes, dyslipidemia, hypertension, and hyperuricemia were recruited. Dental function was assessed with a gummy jelly test, wherein glucose elution from a chewed gummy jelly was measured. Tongue-lip motor function was measured as repeatedly pronounced syllables per second. The association of clinical variables with the two functions was analyzed using multivariate linear regression models. RESULTS: The mean measurement of dental function was 202 ± 73 mg/dL, and that of tongue-lip motor function was 5.5 ± 1.0 times/s. Clinical variables independently associated with dental function (mg/dL) were age (adjusted regression coefficient ß = -9.8 per standard deviation [SD]), smoking (ß = -14.4 and -25.9 for past and current smoking, respectively), body mass index (BMI) 25-30 and ≥30 versus 20-25 kg/m2 (ß = -14.7 and -23.1, respectively), diabetes (ß = -11.9), hemoglobin A1c level ≥64 mmol/mol (ß = -14.6), gait speed (ß = 6.2 per SD), and handgrip strength (ß = 7.5 and 7.7 per SD for males and females, respectively) (all P < 0.05). Clinical variables independently associated with tongue-lip motor function (times/s) were age (ß = -0.31 per SD), BMI ≥ 30 versus 20-25 kg/m2 (ß = -0.24), diabetes (ß = -0.22), dyslipidemia (ß = 0.16), gait speed (ß = 0.12 per SD), and handgrip strength (ß = 0.18 and 0.13 per SD for males and females, respectively) (all P < 0.05). CONCLUSIONS: Obesity, diabetes, physical frailty, and old age were shared risk factors for decreased dental and tongue-lip motor functions in patients with metabolic diseases.

Coincidence of Large Adrenal Cyst and Prominent Hyporeninemic Hyperaldosteronism.

A 67-year-old Japanese woman who had end-stage renal disease was referred to our hospital for kidney transplantation. Abdominal CT revealed a large adrenal mass with inhomogeneity. She had a history of hospitalization for stroke and heart failure and exhibited prominent hyporeninemic hyperaldosteronism. Histological examination of the resected tumor with anti-CYP11B2 antibody indicated that she had a vascular endothelial cyst with primary aldosteronism (PA) due to multiple adrenocortical micronodules. This report implicates the pathological interaction between adrenal vascular cysts and PA-mediated vascular damage of the adrenal vein.

Preoperative fundus examination in patients with diabetes scheduled for surgery.

This study aimed to show the proportion of fundus examinations in patients with diabetes who were scheduled for surgery. We retrospectively analyzed 455 consecutive patients with diabetes admitted for surgery. Just 49% had fundus examinations before hospitalization. The decision tree analysis showed that the type of family doctor was the first split associated with fundus examination; patients treated by a diabetes specialist were more likely to receive the examination. In this subgroup, glycated hemoglobin levels ≥8.0% and age ≥71 years were associated with a lower proportion of receiving the examination. In patients whose family doctor was not a diabetes specialist, glycated hemoglobin levels <7.2% and body mass index <27.4 kg/m2 without severe comorbidities were associated with a higher proportion of receiving the examination. In conclusion, half of patients scheduled for surgery did not receive fundus examinations. A high-risk population for not receiving the examination varied with the consultation setting.

Association between poor psychosocial conditions and diabetic nephropathy in Japanese type 2 diabetes patients: A cross-sectional study.

AIMS/INTRODUCTION: It is suggested that a positive psychosocial condition has a good effect on health and glycemic control. However, there has been no research to evaluate the association between positive psychosocial factors and diabetic nephropathy (DN). The aim of the present study was to evaluate the association between psychosocial factors and DN in patients with type 2 diabetes. MATERIAL AND METHODS: To assess psychosocial condition, six indicators (happiness score, Life Orientation Test-revised score as an indicator of dispositional optimism, laughter frequency, self-awareness of stress, social network and social support) were assessed by a self-administered questionnaire, and associations between these psychosocial indicators and the presence of DN were examined. RESULTS: A cross-sectional analysis of patients with (n = 123) and without DN (n = 220) showed that a high score for happiness (odds ratio [OR] per 1 standard deviation 0.71, 95% confidence interval [CI] 0.57-0.89, P = 0.003), high Life Orientation Test-revised score (OR per 1 standard deviation 0.77, 95% CI: 0.61-0.98, P = 0.035), less self-awareness of stress (OR 0.56, 95% CI: 0.34-0.90, P = 0.017), high connection of social network (OR 0.55, 95% CI: 0.35-0.87, P = 0.010) and high social support (OR 0.61, 95% CI: 0.38-0.96, P = 0.035) were associated with a reduced risk of prevalence of DN. Similar results were observed even after adjustment for the following conventional risk factors of DN: age, sex, duration of diabetes, hemoglobin A1c, hypertension, dyslipidemia and current smoking. CONCLUSIONS: The present study showed that five out of six prespecified indicators of psychosocial condition were significantly associated with the presence of DN in Japanese patients with type 2 diabetes.

Glucotoxicity induces abnormal glucagon secretion through impaired insulin signaling in InR1G cells.

The significance of glucagon in the pathophysiology of diabetes mellitus is widely recognized, but the mechanisms underlying dysregulated glucagon secretion are still unclear. Here, we explored the molecular mechanisms of glucagon dysregulation, using an in vitro model. Hamster-derived glucagon-secreting InR1G cells were exposed to high glucose (25 mM) levels for 12 h before analyzing glucagon secretion and the activity of components involved in insulin signaling. High-glucose treatment induced increased glucagon secretion in InR1G cells, which represents a hallmark of diabetes mellitus. This treatment reduced the phosphorylation of Akt, indicating the deterioration of insulin signaling. Simultaneously, oxidative stress and JNK activity were shown to be increased. The inhibition of JNK signaling resulted in the amelioration of high-glucose level-induced glucagon secretion. Abnormally elevated glucagon secretion in diabetes can be reproduced by high-glucose treatment of InR1G cells, and the involvement of high glucose-oxidative stress-JNK-insulin signaling pathway axis has been demonstrated. These data elucidate, at least partly, the previously unclear mechanism of abnormal glucagon secretion, providing insights into a potential novel approach to diabetes treatment, targeting glucagon.

Significant elevation of serum dipeptidyl peptidase-4 activity in young-adult type 1 diabetes.

AIMS: Currently, inhibition of dipeptidyl peptidase-4 (DPP-4) is widely used in the treatment of type 2 diabetes. Application of this strategy is awaited as a new therapeutic approach for type 1 diabetes, but the scientific basis is still lacking. This report describes the evaluation of serum DPP-4 activity in type 1 diabetes compared with control subjects, and assessment of relationships between DPP-4 activity and diabetic complication markers and metabolic variables in type 1 diabetes. METHODS: We examined serum DPP-4 activity in Japanese young-adult type 1 diabetes (n=76, females 69.7%, age 30.9 ± 6.2 years, duration of diabetes 16.5 ± 11.1 years; mean ± SD) and healthy controls (n=22). Association of the enzymatic activity with diabetic micro- and macro- vascular complication markers and clinical parameters was also assessed. RESULTS: Subjects with type 1 diabetes displayed significantly higher serum DPP-4 activity than healthy controls (relative value, control: 1.00 ± 0.28, T1D, 1.29 ± 0.38; p=0.0011) independent of other clinical parameters. In type 1 diabetes, DPP-4 activity was positively correlated with duration of diabetes (r=0.248, p=0.031), while not correlated with HbA1c level. In univariate correlation analysis of diabetic complication markers and other metabolic parameters, coefficient of variation of R-R intervals (CVR-R) and gamma (γ)-glutamyltransferase (GGT) levels were correlated with DPP-4 activity. GGT was extracted as an independent variable of DPP-4 activity in multivariate analysis (ß=0.213, p=0.035). CONCLUSIONS: Serum DPP-4 activity is significantly elevated in Japanese type 1 diabetes, suggesting pathophysiological significance of the enzyme in type 1 diabetes.

Clinical and endocrinological characteristics of adrenal incidentaloma in Osaka region, Japan.

The aim of this study was to investigate the clinical and endocrinological characteristics of adrenal incidentalomas in Osaka region, Japan. The study was a multicenter retrospective analysis of 150 patients with adrenal incidentalomas who underwent radiographic and endocrine evaluations between 2005 and 2013. Most adrenal incidentalomas were discovered by computed tomography (77.0%) and the rest were identified by abdominal ultrasonography (14.6%), magnetic resonance imaging (4.2%), or positron emission tomography (4.2%). Adrenal incidentalomas were more frequently localized on the left side than on the right. The average diameter of tumors was 21 ± 11 mm. On endocrinological evaluation, 14 patients were diagnosed with primary aldosteronism (9.3%), 10 with subclinical Cushing's syndrome (6.7%), 7 with pheochromocytoma (4.7%), 7 with Cushing's syndrome (4.7%), 2 with both subclinical Cushing's syndrome and primary aldosteronism (1.3%), and 110 with non-functioning tumors (73.3%). Patients with functioning tumors were significantly younger and had larger tumor diameters than those with non-functioning tumors. Except for hypertension, complications were comparable between patients with functioning and non-functioning tumors, including the presence of glucose intolerance, cardiovascular disease, and dyslipidemia. In conclusion, a higher prevalence of primary aldosteronism was observed compared with a previous report. Complications were comparable between patients with functioning and non-functioning tumors, including the frequencies of glucose intolerance, cardiovascular disease, and dyslipidemia. Long-term follow-up is required in patients with non-functioning tumors because the frequency of complications, such as glucose intolerance, cardiovascular disease, and dyslipidemia, was equal to that in patients with functioning tumors.

Appropriate therapy for type 2 diabetes mellitus in view of pancreatic ß-cell glucose toxicity: "the earlier, the better".

Pancreatic ß-cells secrete insulin when blood glucose levels become high; however, when ß-cells are chronically exposed to hyperglycemia, ß-cell function gradually deteriorates, which is known as ß-cell glucose toxicity. In the diabetic state, nuclear expression of the pancreatic transcription factors pancreatic and duodenal homeobox 1 (PDX-1) and v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MafA) is decreased. In addition, incretin receptor expression in ß-cells is decreased, which is likely involved in the impairment of incretin effects in diabetes. Clinically, it is important to select appropriate therapy for type 2 diabetes mellitus (T2DM) so that ß-cell function can be preserved. In addition, when appropriate pharmacological interventions against ß-cell glucose toxicity are started at the early stages of diabetes, ß-cell function is substantially restored, which is not observed if treatment is started at advanced stages. These observations indicate that it is likely that downregulation of pancreatic transcription factors and/or incretin receptors is involved in ß-cell dysfunction observed in T2DM and it is very important to start appropriate pharmacological intervention against ß-cell glucose toxicity in the early stages of diabetes.

Activation of GLP-1 and gastrin signalling induces in vivo reprogramming of pancreatic exocrine cells into beta cells in mice.

AIMS/HYPOTHESIS: Lineage conversion of non-beta cells into insulin-producing cells has been proposed as a therapy for the cure of diabetes. Glucagon-like peptide-1 (GLP-1) and its derivatives can induce beta cell neogenesis in vitro and beta cell mass expansion in vivo, but GLP-1 signalling has not been shown to regulate cell fate decisions in vivo. We therefore tested the impact of GLP-1 receptor (GLP1R) expression on beta cell differentiation in vivo. METHODS: Mice overexpressing GLP1R in pancreatic exocrine cells were generated by Cre-mediated recombination in sex-determining region Y-box 9 (SOX9)-expressing cells and then treated with exendin-4 and/or gastrin. Histological analysis was performed to detect cellular reprogramming from the exocrine lineage into insulin-producing cells. RESULTS: Whereas no newly generated beta cells were detected in the mice treated with exendin-4 alone, treatment with gastrin only induced the conversion of exocrine cells into insulin-producing cells. Furthermore, the overexpression of GLP1R, together with gastrin and exendin-4, synergistically promoted beta cell neogenesis accompanied by the formation of islet-like clusters. These newly generated beta cells expressed beta cell specific transcription factors, such as pancreatic and duodenal homeobox 1 (PDX1), NK6 homeobox 1 (NKX6.1) and musculoaponeurotic fibrosarcoma oncogene family A (MafA). These mice showed no histological evidence of pancreatitis or pancreatic dysplasia in their acini and had normal plasma amylase levels. CONCLUSIONS/INTERPRETATION: Activation of GLP-1 and gastrin signalling induces beta cell neogenesis in the exocrine lineage without any deleterious pancreatic changes, which may lead to a potential therapy to cure diabetes by generating surrogate beta cells.

An inverse U-shaped association of late and peak insulin levels during an oral glucose load with glucose intolerance in a Japanese population: a cross-sectional study.

The current study investigated the association of post-load insulin levels with glucose tolerance in a Japanese population. A total of 1450 Japanese employees who underwent a 75-g oral glucose tolerance test (OGTT) were included. Glucose tolerance was assessed by 120-min glucose levels during a 75-g OGTT. A penalized cubic regression spline model analysis revealed that the 60- and 120-min insulin levels, but not 0- or 30-min insulin levels, had an inverse U-shaped relationship to the 120-min glucose level. Furthermore, peak insulin level followed an inverse U shape in relation to the 120-min glucose level, whereas the peak of insulin appeared at a later point in time as the 120-min glucose level increased. These associations were similarly observed in both obese and non-obese subgroups, although obesity was associated with higher insulin levels. Peak insulin levels also demonstrated an inverse U shape in association with 0-min glucose levels and indices of ß cell function, assessed by the disposition index and the ß-cell function index. In conclusion, peak insulin levels followed an inverse U shape in relation to glucose intolerance in a Japanese population, whereas the impairment of glucose tolerance was associated with a delay in the time to reach peak insulin levels.

Interferon stimulated gene 15 has an anti-apoptotic effect on MIN6 cells.

Type 1 diabetes, one of two major forms of diabetes, results from the complete destruction of pancreatic beta cells. Viral infection has been suggested to be a trigger of beta cell destruction, the pathogenesis of type 1 diabetes. The aim of this study was to clarify the role of the protein encoded by intherferon stimulated gene (ISG) 15, an antiviral effector, in the development of this clinical entity. We used the mouse beta cell line MIN6 to investigate the role of ISG15 and paid special attention to apoptosis. Although not detected in native MIN6 cells, free ISG15 and ISG15 conjugated proteins were both present in dose-dependently increased amounts following stimulation with interferon alpha. As assessed both by caspase 3/7 activity and an annexin V assay, the percentage of apoptotic MIN6 cells (after exposure to the inflammatory cytokines of interleukin-1beta plus interferon gamma or tumor necrosis factor alpha) was decreased by pretreatment with adenovirus-expressing ISG15 and increased by expressing a short hairpin RNA directed against ISG15. In conclusion, ISG15 has an anti-apoptotic effect on MIN6 cells. Thus, promoting ISG15 expression in the pancreatic beta cells could be a potential therapeutic approach for patients with type 1 diabetes.