The effects of ipragliflozin on the liver-to-spleen attenuation ratio as assessed by computed tomography and on alanine transaminase levels in Japanese patients with type 2 diabetes mellitus.

We assessed the effects of a 12-week ipragliflozin treatment on the liver-to-spleen attenuation ratio (L/S ratio) using computed tomography and on alanine transaminase (ALT) levels in Japanese patients with type 2 diabetes mellitus (T2DM). Sixty-two patients with T2DM [age, 56 ± 8 years; hemoglobin A1c (HbA1c) levels, 8.1 ± 0.9%; body mass index (BMI), 27.5 ± 3.3 kg/m2] were randomly assigned in a 2:1 ratio to receive ipragliflozin (50 mg/day; ipragliflozin group; n = 40) or continued treatment (control group; n = 22) for 12 weeks. The primary endpoints were changes in ALT levels; the secondary endpoints included changes in the L/S ratio and in the visceral fat area (VFA) and subcutaneous fat area (SFA) before and after 12 weeks of the treatment as assessed by computed tomography. ALT levels (-12.45 vs. +5.82 IU/l, P < 0.001), L/S ratio (+0.07 vs. -0.08, P < 0.001), SFA (-5.8 vs. +13.3 cm2, P < 0.05), and VFA (+1.4 vs. +20.4 cm2, P < 0.05) significantly changed from baseline in the ipragliflozin group compared with the values in the control group. Multiple regression analysis among all subjects revealed that the independent factor contributing to the %ΔALT and %ΔL/C ratio was treatment group alone (ipragliflozin group = 1; control group = 0; ß coefficient = -32.08, P < 0.001 and ß coefficient = 19.98, P < 0.05, respectively). Thus, ipragliflozin may lower ALT levels associated with increased L/S ratios, indicating its potential therapeutic efficacy in T2DM-associated hepatic steatosis.

Selenoprotein P as a diabetes-associated hepatokine that impairs angiogenesis by inducing VEGF resistance in vascular endothelial cells.

AIMS/HYPOTHESIS: Impaired angiogenesis induced by vascular endothelial growth factor (VEGF) resistance is a hallmark of vascular complications in type 2 diabetes; however, its molecular mechanism is not fully understood. We have previously identified selenoprotein P (SeP, encoded by the SEPP1 gene in humans) as a liver-derived secretory protein that induces insulin resistance. Levels of serum SeP and hepatic expression of SEPP1 are elevated in type 2 diabetes. Here, we investigated the effects of SeP on VEGF signalling and angiogenesis. METHODS: We assessed the action of glucose on Sepp1 expression in cultured hepatocytes. We examined the actions of SeP on VEGF signalling and VEGF-induced angiogenesis in HUVECs. We assessed wound healing in mice with hepatic SeP overexpression or SeP deletion. The blood flow recovery after ischaemia was also examined by using hindlimb ischaemia model with Sepp1-heterozygous-knockout mice. RESULTS: Treatment with glucose increased gene expression and transcriptional activity for Sepp1 in H4IIEC hepatocytes. Physiological concentrations of SeP inhibited VEGF-stimulated cell proliferation, tubule formation and migration in HUVECs. SeP suppressed VEGF-induced reactive oxygen species (ROS) generation and phosphorylation of VEGF receptor 2 (VEGFR2) and extracellular signal-regulated kinase 1/2 (ERK1/2) in HUVECs. Wound closure was impaired in the mice overexpressing Sepp1, whereas it was improved in SeP (-/-)mice. SeP (+/-)mice showed an increase in blood flow recovery and vascular endothelial cells after hindlimb ischaemia. CONCLUSIONS/INTERPRETATION: The hepatokine SeP may be a novel therapeutic target for impaired angiogenesis in type 2 diabetes.

Proteasome dysfunction mediates obesity-induced endoplasmic reticulum stress and insulin resistance in the liver.

Chronic endoplasmic reticulum (ER) stress is a major contributor to obesity-induced insulin resistance in the liver. However, the molecular link between obesity and ER stress remains to be identified. Proteasomes are important multicatalytic enzyme complexes that degrade misfolded and oxidized proteins. Here, we report that both mouse models of obesity and diabetes and proteasome activator (PA)28-null mice showed 30-40% reduction in proteasome activity and accumulation of polyubiquitinated proteins in the liver. PA28-null mice also showed hepatic steatosis, decreased hepatic insulin signaling, and increased hepatic glucose production. The link between proteasome dysfunction and hepatic insulin resistance involves ER stress leading to hyperactivation of c-Jun NH2-terminal kinase in the liver. Administration of a chemical chaperone, phenylbutyric acid (PBA), partially rescued the phenotypes of PA28-null mice. To confirm part of the results obtained from in vivo experiments, we pretreated rat hepatoma-derived H4IIEC3 cells with bortezomib, a selective inhibitor of the 26S proteasome. Bortezomib causes ER stress and insulin resistance in vitro--responses that are partly blocked by PBA. Taken together, our data suggest that proteasome dysfunction mediates obesity-induced ER stress, leading to insulin resistance in the liver.

Thyroglobulin gene mutation with cold nodule on thyroid scintigraphy.

Thyroglobulin gene mutation is a rare cause of congenital hypothyroidism, but thyroglobulin gene mutations are thought to be associated with thyroid cancer development. A 21-year-old Japanese man treated with levothyroxine for congenital hypothyroidism had an enlarged thyroid gland with undetectable serum thyroglobulin despite elevated serum TSH level. The patient was diagnosed with thyroglobulin gene mutation, with compound heterozygosity for Gly304Cys missense mutation and Arg432X nonsense mutation. Ultrasonography showed a hypovascular large tumor in the left lobe that appeared as a cold nodule on thyroid scintigraphy. He underwent total thyroidectomy, but pathological study did not reveal findings of thyroid carcinoma, but rather a hyperplastic nodule with hemorrhage. Strong cytoplasmic thyroglobulin immunostaining was observed, but sodium iodide symporter immunostaining was hardly detected in the hyperplastic nodule. The clinical characteristics of patients with thyroglobulin gene mutations are diverse, and some patients are diagnosed by chance on examination of goiter in adults. The presence of thyroid tumors that appear as cold nodules on thyroid scintigraphy should consider the potential for thyroid carcinoma, if the patient has relatively low serum thyroglobulin concentration in relation to the degree of TSH without thyroglobulin autoantibody.

Duodenal adenocarcinoma with neuroendocrine features in a patient with acromegaly and thyroid papillary adenocarcinoma: a unique combination of endocrine neoplasia.

A 67-year-old woman with familial clustering of thyroid papillary adenocarcinoma was diagnosed with acromegaly due to pituitary macroadenoma. She had multiple skin vegetations, but had no parathyroid and pancreas diseases. Before transsphenoidal surgery, she was further diagnosed as having a duodenal tumor and multiple hypervascular liver nodules. Biopsy specimens from the duodenal tumor and liver nodules were diagnosed histologically as moderately differentiated adenocarcinoma. Immunohistochemically, the tumor cells were positive for chromogranin, synaptophysin and somatostatin receptor 2a, suggestive for neuroendocrine features. After surgery, the patient was not in biochemical remission, and octreotide treatment was initiated. The duodenal cancer was treated with chemotherapy (neoadjuvant cisplatin and S-1). After 24 months, the patient's insulin-like growth factor I level had been normalized, and her liver tumors had not progressed macroscopically. This is a rare case of acromegaly associated with multiple endocrine tumors, not being categorized as conventional multiple endocrine neoplasia. Octreotide treatment might have had beneficial effects on our patient's duodenal adenocarcinoma and liver metastases, both directly via SSTR2a and indirectly via GH suppression, thereby contributing to their slow progression.

Pharmacokinetics and pharmacodynamics of insulin aspart in patients with type 2 diabetes: assessment using a meal tolerance test under clinical conditions.

1. Few studies have evaluated the pharmacokinetics of rapid-acting insulin analogues in patients with Type 2 diabetes, especially under clinical conditions. The aim of the present study was to assess both the pharmacokinetics and pharmacodynamics of insulin aspart in Type 2 diabetic patients who were being treated with the analogue alone. 2. Meal tolerance tests with and without self-injection of a customary dose of insulin aspart (0.05-0.22 U/kg) were conducted in 20 patients in a randomized cross-over study. 3. The dose of insulin aspart (per bodyweight) was significantly correlated with both the maximum concentration (r(2) = 0.59; P < 0.01) and area under the concentration-time curve for insulin aspart (r(2) = 0.53; P < 0.01). However, the time to maximum concentration (T(max)), which varied widely from < 60 to ≥ 120 min, was not associated with either dosage (r(2) = 0.02; P = 0.51) or body mass index (r(2) = 0.02; P = 0.57). Injection of insulin aspart exacerbated delayed hyperinsulinaemia after meal loading, mainly in patients with T(max) ≥ 120 min. With regard to pharmacodynamics, insulin aspart had favourable effects on postprandial hyperglycaemia, hyperglucagonaemia and hyperlipidaemia. 4. The T(max) for this insulin analogue differed greatly between individuals and delayed hyperinsulinaemia was particularly exacerbated in patients with higher T(max) values. Identification of the factors contributing to interindividual variation in the absorption lag time is essential for improving the efficacy and safety of insulin aspart.

Inverse correlation between serum levels of selenoprotein P and adiponectin in patients with type 2 diabetes.

BACKGROUND: We recently identified selenoprotein P (SeP) as a liver-derived secretory protein that causes insulin resistance in the liver and skeletal muscle; however, it is unknown whether and, if so, how SeP acts on adipose tissue. The present study tested the hypothesis that SeP is related to hypoadiponectinemia in patients with type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: We compared serum levels of SeP with those of adiponectin and other clinical parameters in 36 patients with type 2 diabetes. We also measured levels of blood adiponectin in SeP knockout mice. Circulating SeP levels were positively correlated with fasting plasma glucose (r = 0.35, P = 0.037) and negatively associated with both total and high-molecular adiponectin in patients with type 2 diabetes (r = -0.355, P = 0.034; r = -0.367, P = 0.028). SeP was a predictor of both total and high-molecular adiponectin, independently of age, body weight, and quantitative insulin sensitivity index (ß = -0.343, P = 0.022; ß = -0.357, P = 0.017). SeP knockout mice exhibited an increase in blood adiponectin levels when fed regular chow or a high sucrose, high fat diet. CONCLUSIONS/SIGNIFICANCE: These results suggest that overproduction of liver-derived secretory protein SeP is connected with hypoadiponectinemia in patients with type 2 diabetes.

Autoimmune polyglandular syndrome type 3 with anorexia.

A 71-year-old man with diabetes mellitus visited our hospital with complaints of anorexia and weight loss (12 kg/3 months). He had megaloblastic anemia, cobalamin level was low, and autoantibody to intrinsic factor was positive. He was treated with intramuscular cyanocobalamin, and he was able to consume meals. GAD autoantibody and ICA were positive, and he was diagnosed with slowly progressive type 1 diabetes mellitus (SPIDDM). Thyroid autoantibodies were positive. According to these findings, he was diagnosed with autoimmune polyglandular syndrome type 3 with SPIDDM, pernicious anemia, and Hashimoto's thyroiditis. Extended periods of cobalamin deficiency can cause serious complications such as ataxia and dementia, and these complications may not be reversible if replacement therapy with cobalamin is delayed. Although type 1 diabetes mellitus with coexisting pernicious anemia is very rare in Japan, physicians should consider the possibility of pernicious anemia when patients with diabetes mellitus have cryptogenic anorexia with the finding of significant macrocytosis (MCV > 100 fL).

Toxic multinodular goiter with low radioactive iodine uptake.

A 74-year-old woman was referred to our hospital for goiter and persistent thyrotoxicosis. She had no signs of ophthalmopathy. She was not taking thyroid hormone. Thyroid CT revealed multiple nodules. The thyroid gland was not detected on (99m)Tc scintigraphy, (123)I uptake rate was 4.5% at 24 hours without hot nodules, and aberrant goiter was negative. After partial thyroidectomy, she was treated with levothyroxine. TRAb was undetectable during the disease course, and focal destructive change or chronic lymphocytic thyroiditis on the pathological specimens was not evident. We report a rare case of toxic multinodular goiter with low radioactive iodine uptake.

Transition of thyroid autoantibodies by rituximab treatment for thyroid MALT lymphoma.

Thyroid MALT lymphoma is an extremely rare malignancy believed to arise against a background of Hashimoto's thyroiditis. Rituximab is a monoclonal antibody directed against B cell specific antigen CD20. Recently, there have been reports that rituximab is effective for autoimmune thyroid diseases such as Graves' disease as well as for treatment of B cell malignant lymphoma. We present the changes in thyroid autoantibodies in Hashimoto's thyroiditis after rituximab administration for 3 cases of thyroid MALT lymphoma. Case 1 had been taking levothyroxine and was diagnosed with thyroid MALT lymphoma. She was treated with rituximab monotherapy, and her thyroid enlargement improved. Anti-thyroid peroxidase antibody (TPOAb) turned negative after rituximab monotherapy, and TSH levels decreased with the same levothyroxine dosage. Case 2 was diagnosed with recurrent thyroid MALT lymphoma after chemotherapy (CHOP). He suffered from leg sensory disturbance because of vincristine sulfate. The patient was treated with rituximab. TPOAb decreased, but did not turn negative. TSH levels were within normal range during the disease course, but TSH levels were low in comparison with before rituximab therapy. Case 3 was diagnosed with thyroid MALT lymphoma after radiation therapy on the neck for laryngeal cancer. Thyroid enlargement improved after rituximab monotherapy, and thyroid autoantibody levels decreased. TSH increased transiently after radiation therapy, but TSH decreased gradually without levothyroxine after rituximab monotherapy. We report 3 cases in which thyroid autoantibody levels in Hashimoto's thyroiditis decreased after rituximab monotherapy for thyroid MALT lymphoma, but it is controversial whether thyroid dysfunction due to Hashimoto's thyroiditis is restored.

A liver-derived secretory protein, selenoprotein P, causes insulin resistance.

The liver may regulate glucose homeostasis by modulating the sensitivity/resistance of peripheral tissues to insulin, by way of the production of secretory proteins, termed hepatokines. Here, we demonstrate that selenoprotein P (SeP), a liver-derived secretory protein, causes insulin resistance. Using serial analysis of gene expression (SAGE) and DNA chip methods, we found that hepatic SeP mRNA levels correlated with insulin resistance in humans. Administration of purified SeP impaired insulin signaling and dysregulated glucose metabolism in both hepatocytes and myocytes. Conversely, both genetic deletion and RNA interference-mediated knockdown of SeP improved systemic insulin sensitivity and glucose tolerance in mice. The metabolic actions of SeP were mediated, at least partly, by inactivation of adenosine monophosphate-activated protein kinase (AMPK). In summary, these results demonstrate a role of SeP in the regulation of glucose metabolism and insulin sensitivity and suggest that SeP may be a therapeutic target for type 2 diabetes.

Cushing's syndrome and big IGF-II associated hypoglycaemia in a patient with adrenocortical carcinoma.

A 41-year-old woman had a general health examination and was diagnosed with a non-functioning adrenocortical carcinoma (ACC). Despite surgery and chemotherapy with mitotane, the ACC progressed with metastases to the lymph nodes, liver and lung. Initially, she developed adrenal insufficiency and was treated with hydrocortisone. As the ACC progressed, it produced superabundant cortisol, resulting in clinically overt Cushing's syndrome. As the liver metastases grew, the patient developed hypoglycaemia with suppression of endogenous insulin secretion. She had to be given large quantities of glucose intravenously to remain normoglycaemic. The serum insulin-like growth factor (IGF)-II/IGF-I ratio had increased to 84. We identified big IGF-II, a primary hormonal mediator of non-islet cell tumour hypoglycaemia (NICTH), in the serum and tumour using western blotting. This is the first case of ACC that showed both Cushing's syndrome and NICTH associated with big IGF-II.

Transient anti-GAD antibody positivity and acute pancreatitis with pancreas tail swelling in a patient with susceptible haplotype for type 1 diabetes mellitus.

A 57-year-old man was admitted to our hospital complaining of poor appetite. He had been diagnosed with diabetes mellitus and was anti-GAD antibody (GAD-Ab) negative 1 year previously, at the age of 56 years old. Abdominal CT revealed pancreas tail swelling; elastase-I level was elevated and he was diagnosed with pancreatitis. The level of GAD-Ab was increased and HLA haplotype was DRB1*0901-DQB1*0303, which is seen frequently in type 1 diabetic Japanese patients. However, his endogenous insulin secretion ability was not deteriorated. After elastase-I level and pancreas swelling improved, GAD-Ab returned to a normal range. One year after the onset of pancreas swelling, he was still not in an insulin-dependent state. In this case, transient GAD-Ab positivity with susceptible haplotype for type 1 diabetes mellitus might have been induced by a GAD antigen discharged from the destroyed islet due to pancreatitis.

Olmesartan ameliorates a dietary rat model of non-alcoholic steatohepatitis through its pleiotropic effects.

Insulin resistance is a major pathological condition associated with obesity and metabolic syndrome. Insulin resistance and the renin-angiotensin system are intimately linked. We evaluated the role of the renin-angiotensin system in the pathogenesis of insulin resistance-associated, non-alcoholic steatohepatitis by using the angiotensin II type 1 receptor blocker olmesartan medoxomil in a diabetic rat model. The effects of olmesartan on methionine- and choline-deficient (MCD) diet-induced steatohepatitis were investigated in obese, diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control Long-Evans Tokushima Otsuka (LETO) rats. Components of the renin-angiotensin system were up-regulated in the livers of OLETF rats, compared with LETO rats. In OLETF, but not LETO, rats, oral administration of olmesartan for 8 weeks ameliorated insulin resistance. Moreover, olmesartan suppressed MCD diet-induced hepatic steatosis and the hepatic expression of lipogenic genes (sterol regulatory element-binding protein-1c and fatty acid synthase) in OLETF, but not LETO, rats. In both OLETF and LETO rats, olmesartan inhibited hepatic oxidative stress (4-hydroxy-2-nonenal-modified protein) and expression of NADPH oxidase. Olmesartan also inhibited hepatic fibrosis, stellate cell activation, and expression of fibrogenic genes (transforming growth factor-beta, alpha 1 [I] procollagen, plasminogen activator inhibitor-1) in both OLETF and LETO rats. In conclusion, pharmacological blockade of the angiotensin II type 1 receptor slows the development of steatohepatitis in the OLETF rat model. This angiotensin II type 1 receptor blocker may exert insulin resistance-associated effects against hepatic steatosis and inflammation as well as direct effects against the generation of reactive oxygen species and fibrogenesis.