Endocrine Journal
Online ISSN : 1348-4540
Print ISSN : 0918-8959
ISSN-L : 0918-8959
Volume 62 , Issue 8
Showing 1-10 articles out of 10 articles from the selected issue
OPINION
ORIGINALS
  • Yemin Zhang, Mao Ye, Leyuan Jack Chen, Mingxin Li, Zhao Tang, Changhua ...
    2015 Volume 62 Issue 8 Pages 673-686
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: May 10, 2015
    JOURNALS FREE ACCESS
    The ubiquitin-proteasome system (UPS) and autophagy are two conserved intracellular proteolytic pathways, responsible for degradation of most cellular proteins in living cells. Currently, both the UPS and autophagy have been suggested to be associated with pathogenesis of insulin resistance and diabetes. However, underlying mechanism remains largely unknown. The purpose of the present study is to investigate the impact of the UPS and autophagy on insulin sensitivity in serum-starved 3T3-L1 adipocytes. Our results show that serum depletion resulted in activation of the UPS and autophagy, accompanied with increased insulin sensitivity. Inhibition of the UPS with bortezomib (BZM), a highly selective, reversible 26S proteasome inhibitor induced compensatory activation of autophagy but did not affect significantly insulin action. Genetic and pharmacological inhibition of autophagy dramatically mitigated serum starvation-elevated insulin sensitivity. In addition, autophagy inhibition compromised UPS function and led to endoplasmic reticulum (ER) stress and unfolded protein response (UPR). Inability of the UPS by BMZ exacerbated autophagy inhibition-induced ER stress and UPR. These results suggest that protein quality control maintained by the UPS and autophagy is required for preserving insulin sensitivity. Importantly, adaptive activation of autophagy plays a critical role in serum starvation-induced insulin sensitization in 3T3-L1 adipocytes.
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  • Renata Swiatkowska-Stodulska, Anna Skibowska-Bielinska, Piotr Wisniews ...
    2015 Volume 62 Issue 8 Pages 687-694
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: May 13, 2015
    JOURNALS FREE ACCESS
    It is universally acknowledged that glucocorticoids are hormones that exert a significant effect on hemostasis. The aim of this study was to analyze the activities of coagulation factors VIII, von Willebrand (vW), IX, X, and XI, in patients with overt and subclinical hypercortisolism, as well as to examine possible associations between activities of these factors and the degree of hypercortisolism. Thirty endogenous hypercortisolemic patients were included in the study. Twelve of them were diagnosed with overt Cushing’s syndrome (OCS), and eighteen with subclinical Cushing’s syndrome (SCS). Healthy, age- and sex-matched volunteers comprised the control group. Activities of coagulation factors VIII, IX, X, and XI were examined using a coagulometric method, and von Willebrand factor (vWF) using an immunoturbidimetric method. Mean activities of examined coagulation factors were significantly higher in OCS patients in comparison to healthy controls. SCS patients had significantly higher mean vWF activities versus controls; and a clear trend toward higher mean activities of other factors in SCS patients versus controls was recorded (but no significant differences). Furthermore, statistically significant positive correlations were found between activities of factor IX and: morning serum cortisol concentrations, 24-hour urinary cortisol excretion values, cortisol concentrations in the overnight suppression test with 1 mg of dexamethasone. Activities of factors X and XI positively correlated with cortisol levels in the overnight suppression test. In endogenous hypercortisolemic patients the coagulation pathway is hyperactivated as indicated by increased activities of coagulation factors. These disorders are evident among patients with overt hypercortisolism.
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  • Yasuko Hayashikawa, Minoru Iwata, Minehiko Inomata, Yukio Kawagishi, K ...
    2015 Volume 62 Issue 8 Pages 695-709
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: May 15, 2015
    JOURNALS FREE ACCESS
    Conflicting findings have been reported regarding the role of adiponectin in asthma. The aim of this study was to evaluate the association of adiponectin with pulmonary functions and asthma in the Japanese population. First, among a general population that participated in a previous study (group 1), we selected 329 subjects after excluding those with asthma, chronic obstructive pulmonary disease, and a smoking history and examined the associations of the serum total adiponectin levels with pulmonary functions. In a second cohort (group 2) consisting of 61 asthmatic patients and 175 control non-asthmatic subjects, we examined the associations between asthma and the levels of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms as well as the ratio of each isoform to total adiponectin level. Although the total adiponectin levels were not significantly different between the asthmatic and control subjects in group 2, the levels were significantly and positively associated with the forced expiratory volume in 1 s after adjustments for confounding factors (P < 0.05) in women in group 1. In group 2, the LMW adiponectin level was significantly higher and the MMW/total adiponectin ratio was significantly lower among the asthmatic subjects than among the control subjects after adjustments for confounding factors in both sexes (P < 0.05). The present study showed that a low total adiponectin level may lead to airway narrowing compatible with asthmatic airways in women, and higher LMW adiponectin levels and lower MMW/total adiponectin ratio are significantly associated with current asthma in both sexes.
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  • Ken Takeshima, Hiroyuki Ariyasu, Hidefumi Inaba, Yuko Inagaki, Hiroyuk ...
    2015 Volume 62 Issue 8 Pages 711-717
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: May 20, 2015
    JOURNALS FREE ACCESS
    Immunoglobulin G4-related disease (IgG4-RD) is characterized by elevated serum IgG4 levels, IgG4-positive plasmacytes, and lymphocyte infiltration into multiple organs. IgG4 thyroiditis is a subset of patients with Hashimoto’s thyroiditis (HT) who exhibited histopathological features of IgG4-RD; its source of serum IgG4 is suggested to be the thyroid gland. Although a relationship between IgG4-RD and IgG4 thyroiditis has been reported, the meaning of serum IgG4 in HT is uncertain. In this report, we prospectively evaluated serum IgG4 levels and clinical features of patients with HT. A total of 149 patients with HT were prospectively recruited into this study. According to the comprehensive diagnostic criteria of IgG4-RD, patients were divided into two groups: elevated IgG4 (>135 mg/dL) and non-elevated IgG4 (≤135 mg/dL). Median serum IgG4 levels of HT patients were 32.0 mg/dL (interquartile range, 20.0-65.0), with a unimodal non-normal distribution. Six patients (4.0%) had elevated serum IgG4 levels above 135 mg/dL. The elevated IgG4 group was older and exhibited enlarged hypoechoic areas in the thyroid gland, as revealed by ultrasonography, relative to the non-elevated IgG4 group. Levothyroxine (L-T4) replacement doses and titers of anti-thyroid antibodies did not differ significantly between the two groups. Two out of six HT patients with elevated serum IgG4 levels had extra-thyroid organ involvement as seen in IgG4-RD. In conclusion, HT patients with elevated serum IgG4 levels shared clinical features with both IgG4-RD and IgG4 thyroiditis. Longer follow-up periods and histopathological assessments are needed to further understand the meaning of elevated serum IgG4 levels in HT.
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  • Shino Kang, Nobuyuki Amino, Takumi Kudo, Eijun Nishihara, Mitsuru Ito, ...
    2015 Volume 62 Issue 8 Pages 719-724
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: May 19, 2015
    JOURNALS FREE ACCESS
    A 54-year-old woman with subclinical hypothyroidism developed liver dysfunction after increasing dose of levothyroxine (L-T4) in tablet form (Thyradin S®) from 25μg to 50μg. Viral hepatitis, autoimmune hepatitis and NASH were ruled out with examinations. After cessation of levothyroxine in 50μg tablet form, liver enzymes gradually returned to normal. She was diagnosed levothyroxine-induced liver injury, based on criteria proposed in DDW-J 2004 workshop. Thyradin S® powder 0.01% (here in after referred to as L-T4 in powder form) was tried as an alternative, and liver enzymes have remained within normal range. As for Thyradin S® tablet, additives are different for each type of levothyroxine sodium content. The difference of additive is whether Fe2O3 is contained or not: it is not included in Thyradin S® 50μg tablet and powder form. Although there are two case reports in the Japanese literature and three case reports in the English literature of liver dysfunction suspected due to L-T4, we cannot find past reports about cases of drug induced liver dysfunction due to Fe2O3 free levothyroxine tablet form. This is a rare case report of drug induced liver injury due to Fe2O3 free levothyroxine tablet form, and administration of L-T4 in powder form may be useful for treatment of cases similar to this one.
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  • Ken Takeshima, Hidefumi Inaba, Hiroyuki Ariyasu, Yasushi Furukawa, Asa ...
    2015 Volume 62 Issue 8 Pages 725-731
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: June 07, 2015
    JOURNALS FREE ACCESS
    Riedel’s thyroiditis (RT) is a rare chronic fibrosing disorder characterized by a hard, infiltrative lesion in the thyroid gland, which is often associated with multifocal fibrosclerosis. Immunoglobulin G4-related disease (IgG4-RD) is typified by infiltration of IgG4-positive plasma cells into multiple organs, resulting in tissue fibrosis and organ dysfunction. In order to evaluate the clinicopathological features of RT and its relationship with IgG4-RD, we performed a Japanese literature search using the keywords “Riedel” and “Riedel’s thyroiditis.” We used the electronic databases Medline and Igaku Chuo Zasshi, the latter of which is the largest medical literature database in Japan. The diagnosis of RT was based on the presence of a fibroinflammatory process with extension into surrounding tissues. Only 10 patients in Japan fulfilled RT diagnostic criteria during the 25-year period between 1988 and 2012. Two patients with confirmed IgG4/IgG immunohistochemical findings demonstrated 43 and 13 IgG4-positive plasma cells per high-power field, respectively, and the IgG4-positive/IgG-positive plasma cell ratios of 20% and less than 5%. Of the 10 patients with RT, two received glucocorticoids, one of whom experienced marked shrinkage of the thyroid lesion. One patient had extra-thyroid involvement in the form of retroperitoneal fibrosis. Although the clinicopathological features of RT suggest that IgG4-RD may be the underlying condition in some cases, further investigation is needed to clarify the etiology of RT in relation to IgG4-RD.
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  • Fang Liu, Hua Qu, Yingjie Li, Qian Tang, Zesong Yang, Hang Wang, Huaco ...
    2015 Volume 62 Issue 8 Pages 733-740
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: June 04, 2015
    JOURNALS FREE ACCESS
    Recent evidence suggests that serum secreted frizzled-related protein (SFRP) 4 may affect β-cell function. In a cross-sectional clinical study, 56 subjects with type 2 diabetes mellitus (T2DM), 52 subjects with impaired glucose tolerance (IGT) and 42 normal glucose tolerance (NGT) subjects were enrolled to investigate the relationship between SFRP4 levels and the first-phase of glucose-stimulated insulin secretion, glucose metabolism and inflammation. Intravenous glucose tolerance tests were conducted, and acute insulin response (AIR), the area under the curve of the first-phase (0-10 min) insulin secretion (AUC), and the glucose disposition index (GDI) were calculated. The serum levels of SFRP4, IL-1β, plasma glucose, serum lipid, and glycated hemoglobin (HbA1c) were measured. Levels of serum SFRP4 and IL-1β in the T2DM group and IGT group were significantly higher than those in the NGT group (P < 0.01). The AIR, AUC and GDI between the three groups showed a progressive decrease from the NGT to IGT groups with the lowest value in the T2DM groups (P < 0.01). The serum SFRP4 levels were negatively correlated with AIR, AUC, GDI and HOMA-β (P < 0.01) and were positively correlated with fasting plasma glucose, HbA1c, hs-CRP, and IL-1β (P < 0.01). Our study provides evidence that the concentrations of serum SFRP4 in T2DM and IGT subjects were increased and were correlated closely with glycose metabolic disorder, the first-phase of glucose-stimulated insulin secretion and chronic low-grade inflammation. SFRP4 may participate in the development of type 2 diabetes mellitus.
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NOTES
  • Fuminori Tatsumi, Hideaki Kaneto, Mitsuru Hashiramoto, Kazuhito Tawara ...
    2015 Volume 62 Issue 8 Pages 741-747
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: June 13, 2015
    JOURNALS FREE ACCESS
    It is known that reactive oxygen species (ROS) are involved in the development of insulin resistance as well as pancreatic β-cell dysfunction both of which are often observed in type 2 diabetes. In this study, we evaluated the effects of azelnidipine, a calcium channel blocker, on ROS-mediated insulin resistance in adipocytes. When 3T3-L1 adipocytes were exposed to ROS, insulin-mediated glucose uptake was suppressed, but such phenomena were not observed in the presence of azelnidipine. Phosphorylation of insulin receptor and phosphorylation of Akt were suppressed by ROS, which was mitigated by azelnidipine treatment. Activation of the JNK pathway induced by ROS was also reduced by azelnidipine. Various inflammatory cytokine levels were increased by ROS, which was also suppressed by azelnidipine treatment. In contrast, adiponectin mRNA and secreted adiponectin levels were reduced by ROS, which was refilled by azelnidipine treatment. In conclusion, azelnidipine preserves insulin signaling and glucose uptake against oxidative stress in 3T3-L1 adipocytes.
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  • Akira Shimatsu, Noriyuki Iwamoto, Toshiaki Tanaka, Akira Teramoto, Mas ...
    2015 Volume 62 Issue 8 Pages 749-756
    Published: 2015
    Released: August 29, 2015
    [Advance publication] Released: June 13, 2015
    JOURNALS FREE ACCESS
    In addition to impaired physical activity, adult GH deficiency (GHD) can decrease quality of life (QOL). Hence, assessment of QOL is important to evaluate the efficacy of GH replacement therapy. This study aimed to identify factors that may be predictive of long-term improvement in QOL among clinical/laboratory variables during GH replacement therapy. The analysis included 83 Japanese adults with GHD who participated in the Hypopituitary Control and Complications Study (HypoCCS). Correlations between the change from baseline in clinical/laboratory variables at 6 months and the change from baseline in Quality of life (Short-Form 36 [SF-36] component scores) at 12 months were examined. Unexpectedly, all component scores were negatively correlated with the change in fasting plasma glucose concentration (FPG) (physical component summary [PCS], r = -0.456; mental component summary [MCS], r = -0.523; role/social component summary [RCS], r = -0.433). The change in MCS was positively correlated with the change in insulin-like growth factor-1 standard deviation score (IGF-1 SDS) (r = 0.417). The change in PCS was positively correlated with the change in body fat (r = 0.551). The change in RCS was positively correlated with the change in waist circumference (r = 0.528). Short-term changes in several clinical/laboratory variables, most notably FPG and IGF-1 SDS, were correlated with long-term changes in QOL. The clinical importance of these correlations for predicting GH replacement treatment efficacy warrants further investigation.
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