High sex hormone-binding globulin concentration is a risk factor for high fibrosis-4 index in middle-aged Japanese men

Low endogenous testosterone and sex hormone-binding globulin (SHBG) concentrations have been reported to be associated with metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). However, little is known about the relationships between testosterone or SHBG and liver fibrosis in NAFLD. Thus, we aimed to clarify the relationships between serum testosterone or SHBG concentration and fibrosis-4 (FIB-4) index, a marker of liver fibrosis. Serum testosterone was assayed in various forms (total testosterone [TT], calculated free testosterone [cFT], calculated bioavailable testosterone [cbT], and SHBG) and metabolic markers were also measured in 363 Japanese men (mean age 51.1 ± 8.7 years) at routine health examinations. We then attempted to identify the factors contributing to liver fibrosis by investigating the associations between the metabolic markers, including testosterone, and FIB-4 index. People with a relatively high FIB-4 index (≥1.3) demonstrated lower cFT, cbT, homeostasis model assessment (HOMA)-β, low-density lipoprotein-cholesterol, and blood urea nitrogen, but higher SHBG, than those with a lower FIB-4 index (<1.3). There were no significant differences in HbA1c, fasting glucose concentration, HOMA-R, or metabolic syndrome prevalence between the two groups. Binary regression analysis revealed that SHBG ≥52 nmol/L and cFT <8.0 ng/dL were statistically significant risk factors for FIB-4 index ≥1.3. Receiver operating characteristic analysis revealed that cFT <7.62 ng/dL (area under the curve [AUC] = 0.639) and SHBG ≥49.8 nmol/L (AUC = 0.649) were the strongest risk factors for FIB-4 index ≥1.3. In contrast to previous findings showing low SHBG concentrations in NAFLD, we provide evidence that high SHBG and low bioactive testosterone are associated with liver fibrosis.

High Prevalence of Diabetes in Patients With Primary Aldosteronism (PA) Associated With Subclinical Hypercortisolism and Prediabetes More Prevalent in Bilateral Than Unilateral PA: A Large, Multicenter Cohort Study in Japan

OBJECTIVE

To investigate the prevalence and causes of diabetes in patients with primary aldosteronism (PA) in a multi-institutional cohort study in Japan.

RESEARCH DESIGN AND METHODS

The prevalence of diabetes was determined in 2,210 patients with PA (diagnosed or glycated hemoglobin [HbA_1c] ≥6.5% [≥48 mmol/mol]; NGSP) and compared with that of the Japanese general population according to age and sex. In 1,386 patients with PA and clear laterality (unilateral or bilateral), the effects of plasma aldosterone concentration (PAC), hypokalemia (<3.5 mEq/L), suspected subclinical hypercortisolism (SH; serum cortisol ≥1.8 µg/dL after 1-mg dexamethasone suppression test), and PA laterality on the prevalence of diabetes or prediabetes (5.7% ≤ HbA_1c <6.5% [39 mmol/mol ≤ HbA_1c <48 mmol/mol]) were examined.

RESULTS

Of the 2,210 patients with PA, 477 (21.6%) had diabetes. This prevalence is higher than that in the general population (12.1%) or in 10-year cohorts aged 30-69 years. Logistic regression or χ² test revealed a significant contribution of suspected SH to diabetes. Despite more active PA profiles (e.g., higher PAC and lower potassium concentrations) in unilateral than bilateral PA, BMI and HbA_1c values were significantly higher in bilateral PA. PA laterality had no effect on the prevalence of diabetes; however, the prevalence of prediabetes was significantly higher in bilateral than unilateral PA.

CONCLUSIONS

Individuals with PA have a high prevalence of diabetes, which is associated mainly with SH. The prevalence of prediabetes is greater for bilateral than unilateral PA, suggesting a unique metabolic cause of bilateral PA.

Circular IRE-type RNAs of the NR5A1 gene are formed in adrenocortical cells

The recently discovered circular RNAs (circRNAs) are mostly formed by back-splicing where the downstream 5' splice site splices to the upstream 3' splice site by conventional pre-mRNA splicing. These circRNAs regulate gene expression by acting as sponges for micro-RNAs or RNA-binding proteins. Here we show that the NR5A1 (previously called Ad4BP or SF-1) gene which is exclusively expressed in the adrenal cortex and steroidogenic tissue can form atypical circRNAs by unconventional splicing. Two stem loops with inositol-requiring protein-1α (IRE1α) cleavage sites are connected by an IRE1α cleavage site to form a circRNA (circIRE RNA). From total RNA of normal human adrenal cortex, we detected a circIRE RNA with connected ends by IRE1α cleavage sites in exon 6 and exon 1 (circIRE NR5A1 ex6-1 RNA). circIRE NR5A1 ex6-1 RNA was not detected in the adrenocortical cancer cell line, H295R. When IRE1α was expressed in H295R cells a different circIRE NR5A1 RNA connecting IRE1-cleavage sites in exon 7 and exon 1 was detected (circIRE NR5A1 ex7-1 RNA). The expression of this circIRE RNA was inhibited by the IRE1 inhibitor 1, STF-083010, implicating that it was formed via the ER stress pathway, where IRE1α is a major factor. This is the first report of this type of circular RNA connected by IRE1-cleavage sites found to be expressed in mammalian cells in a tissue-specific manner. To our surprise, the concomitant expression of NR5A1 was increased by IRE1α implicating that NR5A1 was not subjected to IRE1-dependent decay of mRNA (RIDD) but rather activating a transcriptional regulatory network to cope with ER stress in steroidogenic tissue reminiscent to XBP1 in other tissue. We believe this is the first report of such tissue-specific transcriptional cascade responding to ER stress as well as the novel finding of circular RNAs connected by IRE1α cleavage sites expressed in mammalian tissue.

Combined treatment with DPP-4 inhibitor linagliptin and SGLT2 inhibitor empagliflozin attenuates neointima formation after vascular injury in diabetic mice

Incretin therapy has emerged as one of the most popular medications for type 2 diabetes. We have previously reported that the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin attenuates neointima formation after vascular injury in non-diabetic mice. In the present study, we examined whether combined treatment with linagliptin and the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin attenuates neointima formation in diabetic mice after vascular injury. Diabetic db/db mice were treated with 3 mg/kg/day linagliptin and/or 30 mg/kg/day empagliflozin from 5 to 10 weeks of age. Body weight was significantly decreased by empagliflozin and the combined treatment. Blood glucose levels and glucose tolerance test results were significantly improved by empagliflozin and the combined treatment, but not by linagliptin. An insulin tolerance test suggested that linagliptin and empagliflozin did not improve insulin sensitivity. In a model of guidewire-induced femoral artery injury in diabetic mice, neointima formation was significantly decreased in mice subjected to combined treatment. In an in vitro assay using rat aortic smooth muscle cells (RASMC), 100, 500, or 1000 nM empagliflozin significantly decreased the RASMC number in a dose-dependent manner. A further significant reduction in RASMC proliferation was observed after combined treatment with 10 nM linagliptin and 100 nM empagliflozin. These data suggest that combined treatment with the DPP-4 inhibitor linagliptin and SGLT2 inhibitor empagliflozin attenuates neointima formation after vascular injury in diabetic mice in vivo and smooth muscle cell proliferation in vitro.

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Linagliptin and empagliflozin attenuate neointima formation in diabetic mice.

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Linagliptin and empagliflozin attenuate VSMC proliferation in vitro.

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Linagliptin and empagliflozin attenuate VSMC DNA synthesis without apoptosis.

SUN-144 High Prevalence of Diabetes in Patients with Primary Aldosteronism (PA) Associated with Subclinical Hypercortisolism and Prediabetes More Prevalent in Bilateral Than Unilateral PA

INTRODUCTION: Primary aldosteronism (PA) is characterized by the autonomous production of aldosterone, usually from an aldosterone producing adenoma in one adrenal gland or idiopathic hyperaldosteronism, with bilateral adrenal lesions. It has been suggested that aldosterone overproduction, hypokalemia, or the complication of subclinical hypercortisolism (SH) in patients with PA, are related to impaired glucose homeostasis and insulin resistance. However, the true contributions of these factors to disturbances of carbohydrate metabolism in PA have not been investigated thoroughly from a large-scale epidemiologic viewpoint. In the present study, the true prevalence of glucose intolerance in more than 2000 patients with PA and its association with aldosterone concentration, hypokalemia, and SH were studied in a multicenter collaborative study. METHODS: The prevalence of diabetes was determined in 2210 patients with PA (diagnosed or HbA_1c ≥6.5%, NGSP) and compared with that of the Japanese general population from the National Survey of the Ministry of Health, Labour and Welfare in 2016, according to age and sex. In 1386 patients with PA and clear laterality (unilateral or bilateral), the effects of plasma aldosterone concentration (PAC), hypokalemia (<3.5 mEq/L), suspected SH (serum cortisol ≥1.8 μg/dL after 1-mg dexamethasone suppression test) and PA laterality on the prevalence of diabetes or prediabetes (5.7%≤HbA_1c<6.5%) were examined. RESULTS: Of the 2210 patients with PA, 477 (21.6%) had diabetes, this prevalence of being higher than that of the general population (12.1%) or in 10 year cohorts aged 30 to 69 years. According to the χ² test, diabetes was present significantly more frequently in PA patients with suspected SH (26.8%) than in those with F-1mgDST <1.8 μg/dL (16.9%; p=0.001). When using logistic regression analysis, it was found that age, sex, BMI, and F-1mgDST ≥1.8 μg/dL were significant contributing factors to the presence of diabetes, whereas laterality of PA was not a significant factor. Despite more active PA profiles (e.g. higher PAC, lower potassium concentrations) in unilateral than bilateral PA, BMI and HbA_1c values were significantly higher in bilateral PA. PA laterality had no effect on prevalence of diabetes; however, prevalence of prediabetes was significantly higher in bilateral than unilateral PA. CONCLUSIONS: Individuals with PA have a high prevalence of diabetes, which is associated mainly with SH. The prevalence of prediabetes is greater for bilateral than unilateral PA, suggesting a unique metabolic cause of bilateral PA. SUPPORT: This research was supported by the Japan Agency for Medical Research and Development (AMED) for the Practical Research Project for Rare/Intractable Disease.

OR02-2 CX-4945 as a Potential Drug for Adrenocortical Carcinoma That Induces Multiple Exon-Skipping and Circular RNA of NR5A1

Orphan nuclear receptor NR5A1 (also called adrenal 4-binding protein/steroidogenic factor-1) is the major regulator of differentiation and function of the adrenal cortex. Adrenocortical carcinoma is rare and deadly with few therapeutic options and is known to have the tendency of increased NR5A1expression along with increased steroidogenesis. Most splicing regulatory compounds are known to have an anti-cancer effect. Thus, we tested these splicing regulatory compounds on the H295R adrenocortical carcinoma cell line and found that CX-4945 had a strong inhibitory effect on growth (IC₅₀=6.4 µM, 72h); four times stronger than the conventional drug, mitotane. In H295R cells treated with CX-4945 for 24 hours, enlarged lysosome and autophagy-related apoptosis were observed. NR5A1was suppressed in mRNA and protein level in these cells, and found CX-4945 strongly induced multiple exon-skipping of the gene. We also found a circular RNA comprised of exon 2 to 4 of NR5A1. CX-4945 suppressed cortisol and aldosterone production and expression of steroid metabolic genes. CX-4945 was originally developed as a casein kinase 2 (CK2) inhibitor. However, CK2 subunit alpha suppression by siRNA for CSNK2 did not affect cell proliferation and expression of NR5A1, suggesting that CX-4945 effect on H295R cells is not through CK2 inhibition. These results suggest CX-4945 attenuates NR5A1-mediated proliferation and steroidogenesis via splicing modification. During analysis of circular RNAs, we found peculiar circular RNAs with endoplasmic reticulum (ER) stress response-related IRE1a-binding sites at the joined ends expressed in normal adrenal cortex, not to be expressed but induced by transiently expressing IRE1a in H295R cells. Taken together, CX-4945 has a strong potential in treating adrenocortical carcinoma since it does not show adrenal failure in its on-going clinical trials of other cancers.

SUN-026 Selective Androgen Receptor Modulator S42 Has Anabolic and Anti-Catabolic Effects on Cultured Myotubes

Introduction: In an effort to develop a selective androgen receptor modulator (SARM) with beneficial activity in energy homeostasis, we previously screened 119 steroid analogs for the ability to induce uncoupling protein-1 (UCP-1) mRNA without increasing prostate-specific antigen promoter activity in human prostate cancer cell line, LNCap. As a result, we identified a novel SARM, S42, which is structural analog of testosterone. S42 dose not stimulate prostate growth but has a beneficial effect on lipid metabolism and also increased muscle weight of lavator ani in orchiectomized Sprague-Dawley rats. These findings prompted us to investigate whether S42 has a direct effect on cultured C2C12 myotubes. Method: Mouse myoblast C2C12 were seeded into 6well-plates at 2×10⁵cells/well and maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS). When the cultured cells became 80-90% confluent, the medium was changed to DMEM supplemented with 2% horse serum (HS) and cells were further cultured for 4 days to induce differentiation into myotubes. Next, the medium was changed to DMEM containing 2% dextran-coated-stripped HS from one day before treatment with various drugs: S42, 5α-dihydrotestosterone (DHT), insulin and rapamycin were tested. Protein and mRNA expression levels were detected by Western blotting and Real time RT-PCR, respectively. Results: Muscle atrophy is mainly controlled by two specific genes encoding muscle ubiquitin ligase, atrogin1 and Muscle RING-Finger Protein1 (MuRF1). S42 significantly lowered expression levels of atrogin1 and MuRF1 in C2C12 myotubes, as determined by Real time RT-PCR. Phosphorylation of p70 S6 kinase (p70S6K), an essential factor for promoting protein synthesis in skeletal muscle, was significantly increased by S42 to almost the same extent as by insulin, but this was prevented by treatment with rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1). However, phosphorylation of Akt upstream regulator mTORC1, was not changed by S42. S42 did not increase insulin-like growth factor 1 (IGF1) mRNA levels in C2C12 myotubes. Conclusion: These results suggest that S42 may have an anabolic effect through activation of mTORC1-p70S6K signaling, independent of IGF1-Akt signaling and may exert an anti-catabolic effect through inhibition of the degradation pathway in cultured C2C12 myotubes.

SAT-062 National PA Registry as a Platform for Standardized Clinical Practice of Primary Aldosteronism in Japan

Background: Primary aldosteronism (PA) is a representative cause of endocrine hypertension characterized by an excess production of aldosterone, hypertension, and cardiovascular complications. Although clinical practice guidelines have been published, diagnostic steps have not been standardized and heterogeneous clinical practice between centers remain to be the major issue of public health in Japan. Aim: To develop PA registry and to produce evidence for clinical practice of PA. Methods: PA registry was developed by Japan PA Study (JPAS) as one of the Incurable Disease Platform Project by the Japan Agency of Medical Research and Development (AMED) and the Ministry of Health, Labor and Welfare in Japan. 2850 PA patients who underwent AVS between 2006 and 2016 in 28 referral centers were registered. Major clinical questions were selected. Results: Evidence produced was as follows. 1) Prevalence of cardiovascular diseases was higher in PA than essential hypertension. Hypokalemia, unilateral subtype and/or PAC greater than 12.5ng/dl were at greater risk of cardiovascular diseases. 2) Since clinical manifestation of PA in elderly was similar to that in younger patients, diagnostic process should essentially follow the same steps. 3) Saline infusion test as a confirmatory test was also useful for subtype diagnosis. 4) More than 90% of PA patients with normokalemia and bilateral disease on CT had bilateral subtype on AVS and needed AVS less weakly. Those aged more than 35 yrs. with marked PA could be spared AVS. 5) While biochemical benefit after ADX was achieved solely with LI greater than 4 of AVS, clinical benefit was largely affected by clinical findings such as age, BMI, and blood pressure. 6) Since prevalence of cortisol co-secretion was high in PA with adrenal tumor smaller than 2cm, DEX suppression test was mandatory. LI greater than 4 was applicable for PA subtype diagnosis even in patients with cortisol co-secretion, but not in those with overt Cushing syndrome. 7) ADX provided superior results in correcting hypertension and hypokalemia than medication in unilateral PA. Conclusions: National PA registry was developed for standardized clinical practice of PA in Japan. Various evidence for elaboration and simplification of clinical practice guideline of PA was created by excluding institutional bias. The PA registry has started to be operated as a part of more comprehensive registry by Japan Rare Adrenal Disease Study (JRAS) for a sustainable platform of future research and development. (Supported by AMED for the Practical Research Project for Rare/Intractable Disease under Grant Number JP17ek0109122; JP18ek0109352).

A High Serum Cortisol/DHEA-S Ratio Is a Risk Factor for Sarcopenia in Elderly Diabetic Patients

Context

Elderly patients with type 2 diabetes mellitus (T2DM) have a high prevalence of frailty and/or sarcopenia. Sarcopenia is thought to be related to discordant secretions of the adrenal hormones cortisol and dehydroepiandrosterone (DHEA), as well as the sulfate ester of DHEA (DHEA-S). The current study sought to evaluate the risk factors for sarcopenia in elderly patients with T2DM.

Design and Patients

We enrolled 108 consecutive elderly patients aged ≥65 years with T2DM (mean age, 76.2 ± 7.3 years; 43.5% males). Sarcopenia was assessed and diagnosed based on the Asian version of the diagnostic criteria regarding muscular strength, physical function, and muscle mass. We assessed various physical parameters, blood tests, and atherosclerosis markers and statistically determined the risk factors for sarcopenia.

Results

Multiple regression analysis showed that the independent risk factors for sarcopenia were a serum cortisol/DHEA-S ratio ≥0.2, diastolic blood pressure <70 mm Hg, Hb concentration <13 g/dL, and an ankle brachial index <1.0. The strongest risk factor for sarcopenia was a serum cortisol/DHEA-S ratio ≥0.2. An increase in the serum cortisol/DHEA-S ratio reflected higher cortisol values and lower DHEA-S values in patients with sarcopenia compared with those in nonsarcopenic patients. The concentrations of cortisol and DHEA-S, as well as the cortisol/DHEA-S ratio, changed in accordance with the severity of sarcopenia.

Conclusions

A relative increase in cortisol may reflect the presence of stress and stimulate muscle catabolism, whereas a relative decrease in DHEA-S may cause a decrease in the anabolic action of DHEA on muscle; the combination of these factors may lead to sarcopenia.

Differences in the actions of adrenaline and noradrenaline with regard to glucose intolerance in patients with pheochromocytoma

Glucose intolerance is often observed in patients with pheochromocytoma. However, it remains controversial issue that glucose intolerance on pheochromocytoma is caused by impaired insulin secretion and/or by increased insulin resistance. We aimed to reveal the mechanism of glucose intolerance on pheochromocytoma with regard to the type and amount of catecholamines released. We evaluated 12 individuals diagnosed with pheochromocytoma and who underwent surgery to remove it. We examined glycemic parameters before and after surgery and investigated the association between the change of parameters of insulin secretion (homeostasis model assessment of β-cell function (HOMA-β)), insulin resistance (homeostasis model assessment of insulin resistance (HOMA-IR)) and that of urinary levels of metanephrine/normetanephrine before and after surgery. Overall, fasting plasma glucose, glycated hemoglobin (HbA1c), HOMA-β, and HOMA-IR were improved significantly after surgery. Regression analysis showed that the improvement in HOMA-β from before to after surgery was significantly positively associated with an improvement in urinary levels of metanephrine from before to after surgery and showed a significantly negative association with improvement in urinary levels of normetanephrine from before to after surgery. The improvement in HOMA-IR from before to after surgery was significantly positively associated with an improvement in urinary levels of normetanephrine from before to after surgery. Our results showed that pheochromocytoma extirpation improved glycemic parameters. Furthermore, the different effects elicited by excess amounts of adrenaline and noradrenaline on glucose intolerance were demonstrated.

Selective androgen receptor modulator, S42 has anabolic and anti-catabolic effects on cultured myotubes

We previously identified a novel selective androgen receptor modulator, S42, that does not stimulate prostate growth but has a beneficial effect on lipid metabolism. S42 also increased muscle weight of the levator ani in orchiectomized Sprague–Dawley rats. These findings prompted us to investigate whether S42 has a direct effect on cultured C2C12 myotubes. S42 significantly lowered expression levels of the skeletal muscle ubiquitin ligase (muscle atrophy-related gene), atrogin1 and Muscle RING-Finger Protein 1(MuRF1) in C2C12 myotubes, as determined by real time PCR. Phosphorylation of p70 S6 kinase (p70S6K), an essential factor for promoting protein synthesis in skeletal muscle, was significantly increased by S42 to almost the same extent as by insulin, but this was significantly prevented by treatment with rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1). However, phosphorylation of Akt, upstream regulator of mTORC1, was not changed by S42. S42 did not increase insulin-like growth factor 1 (Igf1) mRNA levels in C2C12 myotubes. These results suggest that S42 may have an anabolic effect through activation of mTORC1–p70S6K signaling, independent of IGF-1-Akt signaling and may exert an anti-catabolic effect through inhibition of the degradation pathway in cultured C2C12 myotubes.

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A SARM, S42 lowered expression levels of atrogin1 and MuRF1 mRNA in C2C12 myotubes.

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S42 increased phosphorylation of p70S6K through activation of mTORC1 in C2C12 myotubes.

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S42 may have anti-catabolic and anabolic effect in vitro.

Clinical Characteristics and Postoperative Outcomes of Primary Aldosteronism in the Elderly

CONTEXT

Primary aldosteronism (PA) in the elderly has increased in importance in association with population aging.

OBJECTIVE

To investigate the characteristics and outcomes of elderly patients with PA undergoing adrenalectomy.

PATIENTS AND METHODS

Using a database of patients with PA who underwent adrenal venous sampling (AVS), we compared elderly patients (≥65 years old) with nonelderly patients (<65 years old) in terms of characteristics, subtype classification in ACTH-stimulated AVS, and outcomes after adrenalectomy.

RESULTS

The elderly group had a higher prevalence of comorbidities than the nonelderly group. The proportion of the unilateral subtype [defined as a lateralization index (LI) >4] was comparable between the age groups. In patients who received adrenalectomy, biochemical cure was comparable between the groups, whereas persistent hypertension was more common in the elderly group. The prevalences of hyperkalemia and renal impairment (chronic kidney disease stage 3b or higher) were higher in the elderly group. Multiple regression analysis showed that the duration of hypertension predicted persistent hypertension and hyperkalemia and that preoperative estimated glomerular filtration rate predicted renal impairment in the elderly group. LI >4 in AVS was an independent predictor of biochemical cure after adrenalectomy in the elderly group but not in the nonelderly group. Age was negatively associated with biochemical cure in patients with LI ≤4.

CONCLUSION

Adrenalectomy contributes to biochemical improvement in elderly patients if determined in accordance with AVS. The treatment strategy should be determined considering the high postoperative incidence of persistent hypertension and hyperkalemia in elderly patients with a long history of hypertension or renal impairment in those with reduced renal function.

Clinical Investigation of Adrenal Incidentalomas in Japanese Patients of the Fukuoka Region with Updated Diagnostic Criteria for Sub-clinical Cushing's Syndrome

Objectives We retrospectively investigated the clinical and endocrinological characteristics of adrenal incidentalomas. Methods We studied 61 patients who had been diagnosed with adrenal incidentalomas and had undergone detailed clinical and endocrinological evaluations while hospitalized. We used common criteria to diagnose the functional tumors, but for sub-clinical Cushing's syndrome, we used an updated set of diagnosis criteria: serum cortisol ≥1.8 μg/dL after a positive response to a 1-mg dexamethasone suppression test if the patient has a low morning adrenocorticotropic hormone (ACTH) level (<10 pg/mL) and a loss of the diurnal serum cortisol rhythm. Results Of the 61 patients, none (0%) had malignant tumors, 8 (13.1%) had pheochromocytoma, and 15 (24.6%) had primary aldosteronism; when diagnosed by our revised criteria, 13 (21.3%) had cortisol-secreting adenomas (Cushing's syndrome and sub-clinical Cushing's syndrome), and 25 (41.0%) had non-functional tumors. Compared with the non-functional tumor group, the primary aldosteronism group and the cortisol-secreting adenoma group were significantly younger and had significantly higher rates of hypokalemia, whereas the pheochromocytoma group had significantly larger tumors and a significantly lower body mass index. Conclusion Our study found a larger percentage of functional tumors among adrenal incidentalomas than past reports, partly because we used a lower serum cortisol level after a dexamethasone suppression test to diagnose sub-clinical Cushing's syndrome and because all of the patients were hospitalized and could therefore receive more detailed examinations. Young patients with hypokalemia or lean patients with large adrenal tumors warrant particularly careful investigation.

HMGA1a induces alternative splicing of estrogen receptor alpha in MCF-7 human breast cancer cells

The high-mobility group A protein 1a (HMGA1a) protein is known as an oncogene whose expression level in cancer tissue correlates with the malignant potential, and known as a component of senescence-related structures connecting it to tumor suppressor networks in fibroblasts. HMGA1 protein binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. Our previous studies have shown that sequence-specific RNA-binding of HMGA1a induces exon-skipping of Presenilin-2 exon 5 in sporadic Alzheimer disease. Here we show that HMGA1a induced exon-skipping of the estrogen receptor alpha (ERα) gene and increased ERα46 mRNA expression in MCF-7 breast cancer cells. An RNA-decoy of HMGA1a efficiently blocked this event and reduced ERα46 protein expression. Blockage of HMGA1a RNA-binding property consequently induced cell growth through reduced ERα46 expression in MCF-7 cells and increased sensitivity to tamoxifen in the tamoxifen-resistant cell line, MCF-7/TAMR1. Stable expression of an HMGA1a RNA-decoy in MCF-7 cells exhibited decreased ERα46 protein expression and increased estrogen-dependent tumor growth when these cells were implanted in nude mice. These results show HMGA1a is involved in alternative splicing of the ERα gene and related to estrogen-related growth as well as tamoxifen sensitivity in MCF-7 breast cancer cells.

Efficacy and safety of sodium-glucose cotransporter 2 inhibitor ipragliflozin on glycemic control and cardiovascular parameters in Japanese patients with type 2 diabetes mellitus; Fukuoka Study of Ipragliflozin (FUSION)

Sodium-glucose co-transporter-2 inhibitors are newly established anti-diabetic agents with a unique glucose-lowering mechanism. In the present study, we investigated the efficacy and safety of the sodium-glucose co-transporter-2 inhibitor ipragliflozin (Ipra) for metabolic markers and cardiovascular parameters in Japanese patients with type 2 diabetes mellitus (T2DM). This study was an investigator-initiated, open-label, single-arm, multicenter prospective study. Patients with T2DM were treated with 50 mg Ipra for 24 and 52 weeks. The primary outcome investigated was the reduction of glycated hemoglobin (HbA1c) level. The secondary outcome was the change in other metabolic and cardiovascular parameters by 24 weeks. Before and after 52 weeks of treatment, carotid intima-media thickening (IMT) was measured by echography. A total of 134 patients were recruited in the study. A 24-week treatment with 50 mg Ipra daily significantly reduced HbA1c level (-0.6%, p < 0.01). Body mass index (BMI), blood pressure and serum C-peptide were reduced significantly (p < 0.05), while serum glucagon level was unchanged. Interestingly, the serum adiponectin and high-density lipoprotein (HDL) cholesterol levels were significantly increased by Ipra. However, 52 weeks of Ipra treatment did not change carotid IMT. Multiple regression analysis revealed that the only significant contributing factor for HbA1c reduction by Ipra was baseline HbA1c level. These data suggest that Ipra decreased not only glucose level but also BMI, blood pressure and serum C-peptide, and the contributing factor for HbA1c reduction by Ipra was baseline HbA1c level. Further, Ipra improved serum adiponectin and HDL cholesterol levels.

GLP-1 Receptor Agonist Exendin-4 Attenuates NR4A Orphan Nuclear Receptor NOR1 Expression in Vascular Smooth Muscle Cells

AIMS

Recently, incretin therapy has attracted increasing attention because of its potential use in tissue-protective therapy. Neuron-derived orphan receptor 1 (NOR1) is a nuclear orphan receptor that regulates vascular smooth muscle cell (VSMC) proliferation. In the present study, we investigated the vascular-protective effect of Exendin-4 (Ex-4), a glucagon-like peptide-1 receptor agonist, by inhibiting NOR1 expression in VSMCs.

METHODS

We classified 7-week-old male 129X1/SvJ mice into control group and Ex-4 low- and high-dose-treated groups fed normal or high-fat diets, respectively. Endothelial denudation injuries were induced in the femoral artery at 8 weeks of age, followed by the evaluation of neointima formation at 12 weeks of age. To evaluate VSMC proliferation, bromodeoxyuridine incorporation assay and cell cycle distribution analysis were performed. NOR1 and cell cycle regulators were detected using immunohistochemistry, western blotting, quantitative reverse-transcription polymerase chain reaction, and luciferase assays.

RESULTS

Ex-4 treatment reduced vascular injury-induced neointima formation compared with controls. In terms of VSMCs occupying the neointima area, VSMC numbers and NOR1-expressing proliferative cells were significantly decreased by Ex-4 in a dose-dependent manner in both diabetic and non-diabetic mice. In vitro experiments using primary cultured VSMCs revealed that Ex-4 attenuated NOR1 expression by reducing extracellular signal-regulated kinase-mitogen-activated protein kinase and cAMP-responsive element-binding protein phosphorylations. Furthermore, in the cell cycle distribution analysis, serum-induced G1-S phase entry was significantly attenuated by Ex-4 treatment of VSMCs by inhibiting the induction of S-phase kinase-associated protein 2.

CONCLUSION

Ex-4 attenuates neointima formation after vascular injury and VSMC proliferation possibly by inhibiting NOR1 expression.

HMGA1a Induces Alternative Splicing of the Estrogen Receptor-αlpha Gene by Trapping U1 snRNP to an Upstream Pseudo-5' Splice Site

Objectives: The high-mobility group A protein 1a (HMGA1a) protein is known as a transcription factor that binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. We were prompted to decipher the mechanism of HMGA1a-induced alternative splicing of the estrogen receptor alpha (ERα) that we recently reported would alter tamoxifen sensitivity in MCF-7 TAMR1 cells.

Methods: Endogenous expression of full length ERα66 and its isoform ERα46 were evaluated in MCF-7 breast cancer cells by transient expression of HMGA1a and an RNA decoy (2′-O-methylated RNA of the HMGA1a RNA-binding site) that binds to HMGA1a. RNA-binding of HMGA1a was checked by RNA-EMSA. In vitro splicing assay was performed to check the direct involvement of HMGA1a in splicing regulation. RNA-EMSA assay in the presence of purified U1 snRNP was performed with psoralen UV crosslinking to check complex formation of HMGA1a-U1 snRNP at the upstream pseudo-5′ splice site of exon 1.

Results: HMGA1a induced exon skipping of a shortened exon 1 of ERα in in vitro splicing assays that was blocked by the HMGA1a RNA decoy and sequence-specific RNA-binding was confirmed by RNA-EMSA. RNA-EMSA combined with psoralen UV crosslinking showed that HMGA1a trapped purified U1 snRNP at the upstream pseudo-5′ splice site.

Conclusions: Regulation of ERα alternative splicing by an HMGA1a-trapped U1 snRNP complex at the upstream 5′ splice site of exon 1 offers novel insight on 5′ splice site regulation by U1 snRNP as well as a promising target in breast cancer therapy where alternative splicing of ERα is involved.

Correlation Between Lateralization Index of Adrenal Venous Sampling and Standardized Outcome in Primary Aldosteronism

Objectives

The aim of this study was to investigate the impact of adrenal venous sampling (AVS) lateralization cutoffs on surgical outcomes.

Patients and Methods

Cosyntropin-stimulated AVS was used to guide surgical management of 377 patients with primary aldosteronism (PA) who were evaluated 6 months after surgery.

Main Outcome Measures

The proportion of patients that achieved clinical benefit and complete biochemical success based on the AVS aldosterone lateralization index (LI) was determined.

Results

Clinical benefit was achieved in 29 of 47 patients with an LI between 2 and 4, in 66 of 101 with an LI between 4 and 10, and in 158 of 203 with an LI > 10 (P < 0.01 for trend). Complete biochemical success was achieved in 27 of 42 with an LI between 2 and 4, in 60 of 76 with an LI between 4 and 10, and in 127 of 155 with an LI > 10 (P = 0.024 for trend). After adjustment for confounders and using those patients with an LI between 2 and 4 as a reference, a clinical benefit was associated only with those with an LI > 10 (OR, 2.30; 95% CI, 1.03 to 5.16), whereas complete biochemical success was associated with those with an LI between 4 and 10 (OR, 2.83; 95% CI, 1.14 to 7.01) or LI > 10 (OR, 3.55; 95% CI, 1.47 to 8.55).

Conclusions

Difference of clinical outcome was relatively small when strict LI diagnostic threshold was used; biochemical cure was sufficiently achieved when an LI > 4 was used. Our study by standardized outcome measures validated that an LI > 4 may be appropriate for determining unilateral disease in PA.

Accuracy of adrenal computed tomography in predicting the unilateral subtype in young patients with hypokalaemia and elevation of aldosterone in primary aldosteronism

CONTEXT

The current Endocrine Society Guideline suggests that patients aged <35 years with marked primary aldosteronism (PA) and unilateral adrenal lesions on adrenal computed tomography (CT) scan may not need adrenal vein sampling (AVS) before proceeding to unilateral adrenalectomy. This suggestion is, however, based on the data from only one report in the literature.

OBJECTIVE

We sought to determine the accuracy of CT findings in young PA patients who had unilateral adrenal disease on CT with hypokalaemia and elevation of aldosterone.

DESIGN AND PATIENTS

We retrospectively studied 358 PA patients (n = 30, aged <35 years; n = 39, aged 35-40 years; n = 289, aged ≥40 years) with hypokalaemia and elevation of aldosterone and unilateral disease on CT who had successful AVS.

MAIN OUTCOME MEASURE

Accuracy of CT findings is determined by AVS findings and/or surgical outcomes in patients aged <35 years.

RESULTS

Concordance of the diagnosis between CT and AVS was 90% (27/30) in patients aged <35 years, 79% (31/39) in patients aged 35-40 years and 69% (198/289) in those aged ≥40 years (trend for P < .01). Surgical benefit was confirmed in three patients aged <35 years and in three patients aged 35-40 years with the available surgical data who had discordance between CT and AVS findings. Collectively, the diagnostic accuracy of CT findings was 100% (30/30) if aged <35 years and 87% (34/39) if aged 35-40 years.

CONCLUSION

Primary aldosteronism patients aged <35 years with hypokalaemia and elevation of aldosterone and unilateral disease on adrenal CT could be spared AVS.

New diagnostic criteria of adrenal subclinical Cushing's syndrome: opinion from the Japan Endocrine Society

New diagnostic criteria and the treatment policy for adrenal subclinical Cushing's syndrome (SCS) are proposed on behalf of the Japan Endocrine Society. The Japanese version has been published, and the essential contents are presented in this English-language version. The current diagnostic criteria for SCS have elicited two main problems: (i) the relatively low reliability of a low range of serum cortisol essential for the diagnosis by an overnight 1-mg dexamethasone suppression test (DST); (ii) different cutoff values for serum cortisol after a 1-mg DST compared with those of other countries. Thus, new criteria are needed. In the new criteria, three hierarchical cortisol cutoff values, 5.0, 3.0 and 1.8 μg/dL, after a 1-mg DST are presented. Serum cortisol ≥5 μg/dL after a 1-mg DST alone is considered sufficient to judge autonomous cortisol secretion for the diagnosis of SCS, and the current criterion based on serum cortisol ≥3 μg/dL after a 1-mg DST can continue to be used. Clinical evidence suggests that serum cortisol ≥1.8-2.9 μg/dL after a 1-mg DST is not always normal, so cases who meet the cutoff value as well as a basal adrenocorticotropic hormone (ACTH) level <10 pg/mL (or poor ACTH response to corticotropin-releasing hormone (CRH)) and nocturnal serum cortisol ≥5 μg/dL are proposed to have SCS. We suggest surgery if cases show serum cortisol ≥5 μg/dL after a 1-mg DST (or are disheartened by treatment-resistant problems) or suspicious cases of adrenal cancer according to tumor imaging.

Low glycated hemoglobin level is associated with severity of frailty in Japanese elderly diabetes patients

AIMS/INTRODUCTION

Previously, a study using a narrowly defined (physical base) frailty scale reported that both good and bad (U-shaped curve) glycated hemoglobin (HbA1c) levels were frailty risk factors in patients with type 2 diabetes mellitus. However, no such studies in Japan have shown this. We aimed to evaluate the frailty risk factors including HbA1c in elderly Japanese patients with type 2 diabetes mellitus using a broadly defined (both physical and psychosocial base) frailty scale, the Clinical Frailty Scale (CFS).

MATERIALS AND METHODS

We randomly enrolled 132 elderly patients with type 2 diabetes mellitus (aged ≥65 years) and categorized the patients into nine stages of frailty using CFS. Because no patient had CFS 9, patients with a CFS score of 1-4 and 5-8 were defined as non-frail and frail, respectively. We attempted to identify the risk factors of frailty by investigating the association between CFS stage and various patient factors.

RESULTS

Multiple regression analysis showed that an increase in age, low levels of albumin, high-density lipoprotein cholesterol, systolic blood pressure, HbA1c, total cholesterol, and bodyweight were statistically significant and strong independent risk factors for frailty, suggesting that reverse metabolism owing to malnutrition in elderly type 2 diabetes mellitus patients might be involved.

CONCLUSIONS

HbA1c level was not a U-shaped risk for frailty, suggesting that relatively good glycemic control might be more important for frailty than poor control in elderly type 2 diabetes mellitus patients.

Significance of Computed Tomography and Serum Potassium in Predicting Subtype Diagnosis of Primary Aldosteronism

CONTEXT

The number of centers with established adrenal venous sampling (AVS) programs for the subtype diagnosis of primary aldosteronism (PA) is limited.

OBJECTIVE

Aim was to develop an algorithm for AVS based on subtype prediction by computed tomography (CT) and serum potassium.

DESIGN

A multi-institutional retrospective cohort study in Japan.

PATIENTS

A total of 1591 patients with PA were classified into four groups according to CT findings and potassium status. Subtype diagnosis of PA was determined by AVS.

MAIN OUTCOME MEASURE

Prediction value of the combination of CT findings and potassium status for subtype diagnosis.

RESULTS

The percentages of unilateral hyperaldosteronism on AVS were higher in patients with unilateral disease on CT than those with bilateral normal results on CT (50.8% vs 14.6%, P < 0.01), and these percentages were higher in those with hypokalemia than those with normokalemia (58.4% vs 11.5%, P < 0.01). The prevalence and odds ratio for unilateral hyperaldosteronism on AVS were as follows: bilateral normal on CT with normokalemia, 6.2% (reference); unilateral disease on CT with normokalemia, 23.8% and 4.8 [95% confidence interval (CI), 3.1 to 7.2]; bilateral normal on CT with hypokalemia, 38.1% and 9.4 (95% CI, 6.2 to 14.1), and unilateral disease on CT with hypokalemia, 70.6% and 36.4 (95% CI, 24.7 to 53.5).

CONCLUSIONS

Patients with PA with bilateral normal results on CT and normokalemia likely have a low prior probability of a lateralized form of AVS and could be treated medically, whereas those with unilateral disease on CT and hypokalemia have a high probability of a lateralized form of AVS.