Gastrointestinal symptom prevalence depends on disease duration and gastrointestinal region in type 2 diabetes mellitus.

AIM: To unravel relationships between gastrointestinal (GI) symptoms impairing quality of life (QOL) and clinical profiles of diabetes mellitus (DM) patients. METHODS: We enrolled 134 outpatients with type 2 DM. Mean age was 64.7 years, mean body mass index was 24.7 kg/m2, mean glycated hemoglobin was 7.1%, and mean DM duration was 13.7 years. GI symptom-related QOL was determined using the Izumo scale, based on five factors, i.e., heartburn, gastralgia, postprandial fullness, constipation and diarrhea. The sum of scores obtained for the three questions in each domain was calculated, and subjects with a score of 5 or higher were considered to be symptomatic with impaired QOL. JMP Clinical version 5.0 was used for all statistical analyses. RESULTS: Lower abdominal symptoms were found to be more frequent than those affecting the upper abdomen. Diabetic duration and medications showed associations with GI symptoms. We identified differences in peak prevalences of the five symptoms. Gastralgia (P = 0.02 vs 10-14 years) and total GI symptoms (P = 0.01 and P = 0.02 vs 5-9 years and 10-14 years, respectively) peaked at a diabetes duration of 15-19 years. Heartburn (P = 0.004) and postprandial fullness (P = 0.03) tended to increase with disease duration. Constipation and diarrhea showed bimodal peaks, with the first early and the second late (e.g., P = 0.03 at 15-19 years vs 10-14 years for diarrhea) in the disease course. Finally, GI symptoms showed clustering that reflected the region of the GI tract affected, i.e., constipation and diarrhea had similar frequencies (P < 0.0001). CONCLUSION: Our study highlights the importance of questioning patients about QOL impairment due to abdominal symptoms, especially in the early and the late periods of diabetes.

The Improvement of the Hepatic Histological Findings in a Patient with Non-alcoholic Steatohepatitis with Type 2 Diabetes after the Administration of the Sodium-glucose Cotransporter 2 Inhibitor Ipragliflozin.

The patient was a 67-year-old woman with type 2 diabetes and non-alcoholic steatohepatitis (NASH). The administration of the sodium-glucose cotransporter 2 (SGLT2) inhibitor, ipragliflozin improved her liver dysfunction clinically and histologically. The serum alanine aminotransferase (ALT) and ferritin levels decreased to normal limits after treatment for four months. Type IV collagen and hyaluronic acid, both of which were serum fibrotic markers, decreased after treatment. Ultrasonography and computed tomography showed a decrease in the fat deposits in her liver. Her liver sample showed marked improvement, especially in steatosis, inflammation, and ballooning. The SGLT2 inhibitor ipragliflozin may be useful as a specific therapeutic drug for NASH.

LST8 level controls basal p70 S6 kinase and Akt phosphorylations, and mTORC1 and mTORC2 negatively regulate each other by competing for association with LST8.

SUMMARY: LST8 is a component of both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Herein, to examine the role of LST8, a common component of mTOR complexes, in the regulation of mTORC1 and mTORC2, first, we showed over-expression of LST8 in HepG2 to markedly enhance basal phosphorylation levels of not only p70 S6 kinase but also Akt. In contrast, LST8 knockdown by siRNA in HepG2 decreased phosphorylation levels of both p70 S6 kinase and Akt. These results indicate the LST8 expression level to determine basal mTORC1 and mTORC2 activities, since LST8 appears to be the component present at the lowest level in both mTORC1 and mTORC2 complexes. Previously, we reported S6 kinase phosphorylation to be reduced by over-expression of the Cterminally deleted Raptor mutant (Raptor-ΔCT) not binding to mTOR or LST8, while phosphorylation levels of Akt were markedly enhanced with no alteration in IRS-1 phosphorylation or PI 3-kinase activity. Using Raptor-ΔCT, we investigated the competition for association with LST8 between mTORC1 and mTORC2. Over-expression of Raptor-ΔCT abolished formation of the Raptor, S6 kinase, mTOR and LST8 complex, while the amount of LST8 in the Rictor-mTOR complex was increased. Therefore, it is likely that Raptor-mTOR and Rictor-mTOR complexes compete for association with LST8, and this mechanism may contribute to the reciprocal negative regulations of mTORC1 and mTORC2 activities, in terms of their LST8 components.:

Decreased SIRT1 expression and LKB1 phosphorylation occur with long-term high-fat diet feeding, in addition to AMPK phosphorylation impairment in the early phase.

AIMS: Energy sensing systems including AMPK and SIRT1 play important roles in the regulation of hepatic gluconeogenesis and fatty acid oxidation. In this study, we investigated how hepatic LKB1-AMPK signaling and SIRT1 expression are altered after 2 or 8 weeks of HFD feeding. METHODS: The livers of male mice fed a HFD or a standard diet for 2 or 8 weeks were removed. The expression and phosphorylation levels of LKB1, AMPK, ACC and TORC2, and SIRT1 expression levels were examined by immunoblotting. RESULTS: In mice fed a HFD for 2 weeks, the phosphorylations of AMPKα and ACC were decreased without significant alterations in LKB1 phosphorylation or SIRT1 protein levels, while TORC2 protein levels were increased. In mice fed a HFD for 8 weeks, marked reductions in LKB1 phosphorylation and SIRT1 protein amount were observed in addition to the decreased phosphorylations of AMPKα and ACC. CONCLUSIONS: The mechanisms underlying impaired energy sensing signaling differ with the duration of HFD feeding. In the early phase of HFD feeding, LKB1 and SIRT1 were not impaired, while in the later phase of HFD feeding, decreased SIRT1 expression and LKB1 phosphorylation may be involved in the development of severe glucose and lipid intolerance.

Hepatic overexpression of a dominant negative form of raptor enhances Akt phosphorylation and restores insulin sensitivity in K/KAy mice.

Several serine/threonine kinases reportedly phosphorylate serine residues of IRS-1 and thereby induce insulin resistance. In this study, to investigate the effect of mTOR/raptor on insulin signaling and metabolism in K/KAy mice with genetic obesity-associated insulin resistance, a dominant negative raptor, COOH-terminally deleted raptor (raptor-DeltaC(T)), was overexpressed in the liver via injection of its adenovirus into the circulation. Hepatic raptor-DeltaC(T) expression levels were 1.5- to 4-fold that of endogenously expressed raptor. Glucose tolerance in raptor-DeltaC(T)-overexpressing mice improved significantly compared with that of LacZ-overexpressing mice. Insulin-induced activation of p70S6 kinase (p70(S6k)) was significantly suppressed in the livers of raptor-DeltaC(T) overexpressing mice. In addition, insulin-induced IRS-1, Ser(307), and Ser(636/639) phosphorylations were significantly suppressed in the raptor-DeltaC(T)-overexpressing liver, whereas tyrosine phosphorylation of IRS-1 was increased. PI 3-kinase activation in response to insulin stimulation was increased approximately twofold, and Akt phosphorylation was clearly enhanced under both basal and insulin-stimulated conditions in the livers of raptor-DeltaC(T) mice. Thus, our data indicate that suppression of the mTOR/p70(S6k) pathway leads to improved glucose tolerance in K/KAy mice. These observations may contribute to the development of novel antidiabetic agents.

[A case of optic nerve drusen associated with Grönblad-Strandberg syndrome].

PURPOSE: We report a rare case of optic nerve drusen associated with Grönblad-Strandberg syndrome. CASE: The patient was a 29-year-old woman who had pseudoxanthoma elasticum on her neck. OBSERVATIONS: On eye examination, there were no abnormal findings in the anterior segment or ocular media. Ophthalmoscopic examination revealed milky white granular lesions on the optic nerve disc, and angioid streaks around the disc in both eyes. Orbital computerized tomography(CT), B-scan echography and photography with a fluorescein angiography filter identified the granular lesions as optic nerve drusen. With a scanning laser ophthalmoscope(SLO), poorly-visible drusen buried below the nerve head could be detected. The optic nerve drusen could be seen more clearly by infrared laser than by helium-neon laser. CONCLUSIONS: SLO using infrared laser is useful for evaluation of superficial and buried drusen.