SummaryIncretins, hormones released by the gut after meal ingestion, are essential for maintaining systemic glucose homeostasis by stimulating insulin secretion. The effect of incretins on insulin secretion occurs only at elevated glucose concentrations and is mediated by cAMP signaling, but the mechanism linking glucose metabolism and cAMP action in insulin secretion is unknown. We show here, using a metabolomics-based approach, that cytosolic glutamate derived from the malate-aspartate shuttle upon glucose stimulation underlies the stimulatory effect of incretins and that glutamate uptake into insulin granules mediated by cAMP/PKA signaling amplifies insulin release. Glutamate production is diminished in an incretin-unresponsive, insulin-secreting β cell line and pancreatic islets of animal models of human diabetes and obesity. Conversely, a membrane-permeable glutamate precursor restores amplification of insulin secretion in these models. Thus, cytosolic glutamate represents the elusive link between glucose metabolism and cAMP action in incretin-induced insulin secretion.
Calcium plays a fundamental role as second messenger in intracellular signaling and bone serves as the body's calcium reserve to tightly maintain blood calcium levels. Calcium in ingested meal is the main supply and inadequate calcium intake causes osteoporosis and bone fracture. Here, we describe a novel mechanism of how ingested calcium is deposited on bone. Meal ingestion elicits secretion of the gut hormone gastric inhibitory polypeptide (GIP) from endocrine K cells in the duodenum. Bone histomorphometrical analyses revealed that bone formation parameters in the mice lacking GIP receptor (GIPR(-/-)) were significantly lower than those of wild-type (GIPR(+/+)) mice, and that the number of osteoclasts, especially multinuclear osteoclasts, was significantly increased in GIPR(-/-) mice, indicating that GIPR(-/-) mice have high-turnover osteoporosis. In vitro examination showed the percentage of osteoblastic cells undergoing apoptosis to be significantly decreased in the presence of GIP. Because GIPR(-/-) mice exhibited an increased plasma calcium concentration after meal ingestion, GIP directly links calcium contained in meal to calcium deposition on bone.
StatementFamilial hypercholesterolemia (FH) is an autosomal hereditary disease with the 3 major clinical features of hyper-LDL-cholesterolemia, premature coronary artery disease and tendon and skin xanthomas. As there is a considerably high risk of coronary artery disease (CAD), in addition to early diagnosis and intensive treatment, family screening (cascade screening) is required (Recommendation level A)For a diagnosis of FH, at least 2 of the following criteria should be satisfied:① LDL-C ≥ 180 mg/dL, ② Tendon/skin xanthomas, ③ History of FH or premature CAD within 2nd degree blood relatives (Recommendation level A)Intensive lipid-lowering therapy is necessary for the treatment of FH. First-line drug should be statins. (Recommendation level A, Evidence level 3)Screening for CAD as well as asymptomatic atherosclerosis should be conducted periodically in FH patients. (Recommendation level A)For homozygous FH, consider LDL apheresis and treatment with PCSK9 inhibitors or MTP inhibitors. (Recommendation level A)For severe forms of heterozygous FH who have resistant to drug therapy, consider PCSK9 inhibitors and LDL apheresis. (Recommendation level A)Refer FH homozygotes as well as heterozygotes who are resistant to drug therapy, who are children or are pregnant or have the desire to bear children to a specialist. (Recommendation level A)
Purpose Cisplatin plus 5-fluorouracil has been globally accepted as a standard regimen for the treatment for advanced gastric cancer. However, cisplatin has several disadvantages, including renal toxicity and the need for admission. S-1 plus cisplatin has become a standard treatment for advanced gastric cancer in East Asia. This phase III study was designed to evaluate the potential benefits of adding docetaxel to S-1 without a platinum compound in patients with advanced gastric cancer.MethodsPatients were randomly assigned to receive docetaxel plus S-1 or S-1 alone. The docetaxel plus S-1 group received docetaxel on day 1 and oral S-1 on days 1–14 of a 21-day cycle. The S-1 alone group received oral S-1 on days 1–28 of a 42-day cycle. The primary end point was overall survival.ResultsOf the 639 patients enrolled, 635 were eligible for analysis. The median overall survival was 12.5 months in the docetaxel plus S-1 group and 10.8 months in the S-1 alone group (p = 0.032). The median progression-free survival was 5.3 months in the docetaxel plus S-1 group and 4.2 months in the S-1 alone group (p = 0.001). As for adverse events, neutropenia was more frequent in the docetaxel plus S-1 group, but remained manageable.ConclusionAs first-line treatment for advanced gastric cancer, docetaxel plus S-1 significantly improves median overall and progression-free survival as compared with S-1 alone. (ClinicalTrials.gov number: NCT00287768).
The purpose of this study was to quantify circulating tumor cells (CTCs) in advanced gastric cancer (AGC) patients, and to demonstrate the role of CTCs in cancer therapy. This study investigates the hypothesis that CTCs can predict clinical outcomes in patients with AGC. From November 2007 to June 2009, 52 patients with AGC were enrolled into a prospective study. The chemotherapy regimen was an S-1-based regimen (S-1 with or without cisplatin) or paclitaxel. CTCs of whole blood at baseline, 2 weeks, and 4 weeks after initiation of chemotherapy, were isolated and enumerated using immunomagnetics. Patients with ‡4 CTCs at 2-week points and 4-week points had a shorter median progression-free survival (PFS) (1.4, 1.4 months, respectively) than those with the median PFS of <4 CTCs (4.9, 5.0 months, respectively) (log-rank test; P < 0.001, P < 0.001, respectively). Patients with ‡4 CTCs at 2-week points and 4-week points had shorter median overall survival (OS) (3.5, 4.0 months, respectively) than those with the median PFS of <4 CTCs (11.7, 11.4 months, respectively) (log-rank test; P < 0.001, P = 0.001, respectively). In conclusion, this study demonstrates that CTC measurement may be useful as a surrogate marker for determining response to S-1-based or paclitaxel regimens in AGC. (Cancer Sci 2010; 101: 1067-1071 G astric cancer is more prevalent in Asia, Eastern Europe, and Central and South America than in other areas. In Japan, this cancer is one of the most common causes of cancerrelated mortality, despite dramatic advances in diagnosis and treatment. Outcomes are extremely poor in patients with unresectable gastric cancer, with the median survival ranging from 3 to 5 months with the best supportive care.(1-3) The ability to identify patients with the worst prognoses or those destined to progress quickly could have broad clinical applications.Circulating tumor cells (CTCs) or disseminated tumor cells (DTCs) in bone marrow and peripheral blood from patients with cancers have been documented.(4-6) Braun et al. (7,8) reported that 30% of women with primary breast cancer have DTCs in bone marrow, and a 10-year follow-up of these patients revealed a significantly decreased disease-free survival and overall survival (OS) when compared with patients without DTCs. However, aspiration of bone marrow is time consuming and, in many cases, uncomfortable for the patients precluding multiple samplings for therapy monitoring studies. Therefore, recent efforts have concentrated on the detection of CTCs in the peripheral blood of cancer patients. Cristofanilli et al. (9,10) showed in a prospective study that CTC detection provided significant prognostic information for patients with metastatic breast cancer. Cohen et al. (11) showed that the number of CTCs before and during treatment was an independent predictor of PFS and OS in patients with metastatic colorectal cancer. It is not clear whether CTC detection using this system provides prognostic information for patients with advanced gastric cancer. We initiated this study to eva...
BackgroundEndothelial dysfunction is an independent predictor for cardiovascular events in patients with type 2 diabetes (T2DM). Glucagon like peptide‐1 (GLP‐1) reportedly exerts vasodilatory actions, and inhibitors of dipeptidyl peptidase‐4 (DPP‐4), an enzyme‐degrading GLP‐1, are widely used to treat T2DM. We therefore hypothesized that DPP‐4 inhibitors (DPP‐4Is) improve endothelial function in T2DM patients and performed 2 prospective, randomized crossover trials to compare the DPP‐4I sitagliptin and an α‐glucosidase inhibitor, voglibose (in study 1) and the DPP‐4Is sitagliptin and alogliptin (in study 2).Methods and ResultsIn study 1, 24 men with T2DM (46±5 years) were randomized to sitagliptin or voglibose for 6 weeks without washout periods. Surprisingly, sitagliptin significantly reduced flow‐mediated vasodilatation (FMD; −51% compared with baseline, P<0.05) of the brachial artery despite improved diabetic status. In contrast, voglibose did not affect FMD. To confirm this result and determine whether it is a class effect, we conducted another trial (study 2) to compare sitagliptin and alogliptin in 42 T2DM patients (66±8 years) for 6 weeks with 4‐week washout periods. Both DPP‐4Is improved glycemic control but significantly attenuated FMD (7.2/4.3%, P<0.001, before/after sitagliptin; 7.0/4.8%, P<0.001, before/after alogliptin, respectively). Interestingly, FMD reduction was less evident in subjects who were on statins or whose LDL cholesterol levels were reduced by them, but this was not correlated with parameters including DPP‐4 activity and GLP‐1 levels or diabetic parameters.ConclusionsOur 2 independent trials demonstrated that DPP‐4 inhibition attenuated endothelial function as evaluated by FMD in T2DM patients. This unexpected unfavorable effect may be a class effect of DPP‐4Is.Clinical Trial RegistrationURL: http://center.umin.ac.jp, Unique Identifiers: UMIN000005682 (sitagliptin versus voglibose) and UMIN000005681 (sitagliptin versus alogliptin).
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