ATP6AP2 is robustly expressed in pancreatic ß cells and neuroendocrine tumors, and plays a role in maintaining cellular viability.

ATP6AP2, also known as (pro)renin receptor, has been shown to be expressed in several tissues including pancreatic ß cells. Whereas ATP6AP2 plays an important role in regulating insulin secretion in mouse pancreatic ß cells, the expression profiles and roles of ATP6AP2 in human pancreatic endocrine cells and neuroendocrine tumor cells remain unclear. Here in this study, we investigated the expression profiles of ATP6AP2 in pancreatic endocrine cells, and found that ATP6AP2 is robustly expressed in pancreatic insulinoma cells as well as in normal ß cells. Although ATP6AP2 was also expressed in low-grade neuroendocrine tumors, it was not or faintly detected in intermediate- and high-grade neuroendocrine tumors. Knockdown experiments of the Atp6ap2 gene in rat insulinoma-derived INS-1 cells demonstrated decreased cell viability accompanied by a significant increase in apoptotic cells. Taken together, these findings suggest that ATP6AP2 plays a role in maintaining cellular homeostasis in insulinoma cells, which could lead to possible therapeutic approaches for endocrine tumors.

Adult Thyroid Outcomes of Congenital Hypothyroidism.

Background: More than 40 years have passed since the introduction of newborn screening (NBS) for congenital hypothyroidism (CH), and many early diagnosed patients have reached adulthood. Their thyroid morphology and function have been little studied. This cross-sectional, observational study was conducted to characterize the thyroid morphology and function of adult CH patients diagnosed in the framework of NBS for CH. Methods: A total of 103 adult CH patients born after 1979 were enrolled at Ito Hospital, Tokyo, Japan, and were classified into Goiter, Normal gland, and Dysgenesis groups based on ultrasonographic findings. For 60 patients, genetic analysis was performed. Thyroid function test results and the proportion of patients with thyroid nodules were compared among the three groups and between 56 female CH patients and 168 non-CH women matched for thyrotropin levels. Results: A significantly low serum free triiodothyronine/free thyroxine ratio (0.22) was observed in the Dysgenesis group. Thyroid nodules were detected in 14.3% (8/56) of female CH patients, more frequently than in non-CH women. Thyroid nodules were detected most frequently in the Goiter group (71%, 10/14). Genetic defects were identified in 89% (8/9) of patients belonging to the Goiter group, including thyroglobulin defect (33%, 3/9), thyroid peroxidase defect (33%, 3/9), and dual oxidase 2 defect (22%, 2/9). Conclusions: Our results suggest that adults with thyroid dysgenesis on levothyroxine replacement therapy have relative triiodothyronine deficiency. Most adults with goitrous CH have genetic dyshormonogenesis. They are at high risk of developing thyroid nodules. Our findings support the current guideline recommendation that CH patients with dyshormonogenesis should undergo periodic thyroid ultrasonography.

Identification of plasma binding proteins for glucose-dependent insulinotropic polypeptide.

Glucose-dependent insulinotropic polypeptide (GIP), secreted from enteroendocrine K cells, has potent insulin-releasing and extrapancreatic glucoregulatory activities. However, exogenous GIP has less potent biological effects compared with another incretin hormone, GLP-1, which limits its use for the treatment of type 2 diabetes. The fate and secretion of administered native GIP remain unclear. The aim of this study was to identify plasma binding proteins for human GIP. Fluorescent-labelled GIP was added to fresh human plasma and subjected to clear native polyacrylamide gel electrophoresis (CN-PAGE). Then fluorescent protein bands were in-gel trypsin-digested and subjected to liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis, revealing the presence of albumin, immunoglobulin G (IgG) and transferrin. In contrast to GIP, the binding of fluorescent GLP-1 and glucagon to plasma protein fractions were minimal. CN-PAGE analysis of synthetic GIP incubated with human serum albumin, purified IgG or transferrin, and subsequent western blot analysis revealed that GIP binds to each of these proteins. Taken together, these results indicate that GIP readily binds to albumin, IgG and transferrin, three plasma proteins highly abundant in the human peripheral circulation. Separation of protein complexes using CN-PAGE and the identification of in-gel digested proteins by LC-MS/MS analysis provide a promising strategy to identify plasma binding proteins for bioactive peptides.

Effect of Helicobacter pylori eradication on elder cases: Observational study in community-based medicine.

AIM: To examine the effect of Helicobacter pylori (H. pylori) eradication therapy on the extra-gastrointestinal factors in elderly patients by a before-after observational study in community medicine. METHODS: Medical records (1 May 2013-31 January 2014) of 130 patients who underwent H. pylori eradication therapy with 2-year after-eradication observation in our institute were reviewed. Data on sex; age; body weight; body mass index (BMI); mean corpuscular volume (MCV); total protein; low-density lipoprotein cholesterol, triglyceride, haemoglobin A1c and haemoglobin levels and gastric hyperplastic polyps (GHPs) at eradication was extracted. Two-year after-eradication change in data was analysed by paired-sample t-test; relationship between GHPs and subclinical iron deficiency anaemia (IDA) improvement was evaluated. RESULTS: The mean patient age (median, interquartile range) at eradication was 69.6 (71.5, 64-77) years. Paired-sample t-tests showed that body weight, BMI and MCV increased by 0.52 kg (P = 0.018), 0.25 kg/m2 (P = 0.006) and 0.83 fL (P < 0.001), respectively. The nonparametric Mann-Whitney test showed no significant difference in the change rate of MCV after eradication between the groups with and without GHPs (P = 0.892). CONCLUSION: H. pylori eradication therapy prevented weight loss and subclinical IDA in elderly individuals. GHPs were not associated with subclinical IDA.

Diagnosis and management of giant hepatic hemangioma: the usefulness of contrast-enhanced ultrasonography.

Giant hepatic hemangiomas, though often asymptomatic, may require intervention if rapid growth occurs. The imaging studies including the computed tomography, magnetic resonance imaging, and ultrasonography, and so on are effective for the diagnosis and the management of this tumor; however, due to its size and various patterns of these studies, we need to carefully consider the therapeutic methods. Compared to the cost needed for these modalities, recently developed and approved Perflubutane- (Sonazoid-) based contrast agent enhanced ultrasonography is reasonable and safe. The major advantage is the real-time observation of the vascular structure and function of the Kupffer cells. By this procedure, we can carefully follow the tumor growth or character change in a hemangioma and decide the timing of therapeutic intervention, since abdominal pain, abdominal mass, consumptive coagulopathy, and hemangioma growth are the signs for the therapeutic intervention. We reviewed recent reports about Sonazoid-based enhancement and also showed the representative images collected in our department. This is the first review showing the detailed findings of the giant hemangiomas using Perflubutane (Sonazoid). This review will help the physician in making the decision, and we hope that Sonazoid will gain widespread acceptance in the near future.