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1.
This research investigated the effect of enzymatically digested low molecular weight (MW) chitosan oligosaccharide on type 2 diabetes prevention. Three different chitosan oligosaccharide samples with varying MW were evaluated in vitro for inhibition of rat small intestinal α-glucosidase and porcine pancreatic α-amylase (GO2KA1; <1000 Da, GO2KA2; 1000–10,000 Da, GO2KA3; MW > 10,000 Da). The in vitro results showed that all tested samples had similar rat α-glucosidase inhibitory and porcine α-amylase inhibitory activity. Based on these observations, we decided to further investigate the effect of all three samples at a dose of 0.1 g/kg, on reducing postprandial blood glucose levels in Sprague-Dawley (SD) rat model after sucrose loading test. In the animal trial, all tested samples had postprandial blood glucose reduction effect, when compared to control, however GO2KA1 supplementation had the strongest effect. The glucose peak (Cmax) for GO2KA1 and control was 152 mg/dL and 193 mg/dL, respectively. The area under the blood glucose-time curve (AUC) for GO2KA1 and control was 262 h mg/dL and 305 h mg/dL, respectively. Furthermore, the time of peak plasma concentration of blood glucose (Tmax) for GO2KA1 was significantly delayed (0.9 h) compared to control (0.5 h). These results suggest that GO2KA1 could have a beneficial effect for blood glucose management relevant to diabetes prevention in normal and pre-diabetic individuals. The suggested mechanism of action is via inhibition of the carbohydrate hydrolysis enzyme α-glucosidase and since GO2KA1 (MW < 1000 Da) had higher in vivo effect, we hypothesize that it is more readily absorbed and might exert further biological effect once it is absorbed in the blood stream, relevant to blood glucose management.  相似文献   

2.
Current attempts to prevent and manage type 2 diabetes have been moderately effective, and a better understanding of the molecular roots of this complex disease is important to develop more successful and precise treatment options. Recently, we initiated the collective diabetes cross, where four mouse inbred strains differing in their diabetes susceptibility were crossed with the obese and diabetes-prone NZO strain and identified the quantitative trait loci (QTL) Nidd13/NZO, a genomic region on chromosome 13 that correlates with hyperglycemia in NZO allele carriers compared to B6 controls. Subsequent analysis of the critical region, harboring 644 genes, included expression studies in pancreatic islets of congenic Nidd13/NZO mice, integration of single-cell data from parental NZO and B6 islets as well as haplotype analysis. Finally, of the five genes (Acot12, S100z, Ankrd55, Rnf180, and Iqgap2) within the polymorphic haplotype block that are differently expressed in islets of B6 compared to NZO mice, we identified the calcium-binding protein S100z gene to affect islet cell proliferation as well as apoptosis when overexpressed in MIN6 cells. In summary, we define S100z as the most striking gene to be causal for the diabetes QTL Nidd13/NZO by affecting β-cell proliferation and apoptosis. Thus, S100z is an entirely novel diabetes gene regulating islet cell function.  相似文献   

3.
Propolis is a honeybee product with various biological activities, including antidiabetic effects. We previously reported that artepillin C, a prenylated cinnamic acid derivative isolated from Brazilian green propolis, acts as a peroxisome proliferator-activated receptor γ (PPARγ) ligand and promotes adipocyte differentiation. In this study, we examined the effect of baccharin, another major component of Brazilian green propolis, on adipocyte differentiation. The treatment of mouse 3T3-L1 preadipocytes with baccharin resulted in increased lipid accumulation, cellular triglyceride levels, glycerol-3-phosphate dehydrogenase activity, and glucose uptake. The mRNA expression levels of PPARγ and its target genes were also increased by baccharin treatment. Furthermore, baccharin enhanced PPARγ-dependent luciferase activity, suggesting that baccharin promotes adipocyte differentiation via PPARγ activation. In diabetic ob/ob mice, intraperitoneal administration of 50 mg/kg baccharin significantly improved blood glucose levels. Our results suggest that baccharin has a hypoglycemic effect on glucose metabolic disorders, such as type 2 diabetes mellitus.  相似文献   

4.
5.
Previous studies suggest that statins may disturb skeletal muscle lipid metabolism potentially causing lipotoxicity with insulin resistance. We investigated this possibility in wild-type mice (WT) and mice with skeletal muscle PGC-1α overexpression (PGC-1α OE mice). In WT mice, simvastatin had only minor effects on skeletal muscle lipid metabolism but reduced glucose uptake, indicating impaired insulin sensitivity. Muscle PGC-1α overexpression caused lipid droplet accumulation in skeletal muscle with increased expression of the fatty acid transporter CD36, fatty acid binding protein 4, perilipin 5 and CPT1b but without significant impairment of muscle glucose uptake. Simvastatin further increased the lipid droplet accumulation in PGC-1α OE mice and stimulated muscle glucose uptake. In conclusion, the impaired muscle glucose uptake in WT mice treated with simvastatin cannot be explained by lipotoxicity. PGC-1α OE mice are protected from lipotoxicity of fatty acids and triglycerides by increased the expression of FABP4, formation of lipid droplets and increased expression of CPT1b.  相似文献   

6.
Type 2 diabetes (T2D) typically occurs in the setting of obesity and insulin resistance, where hyperglycemia is associated with decreased pancreatic β-cell mass and function. Loss of β-cell mass has variably been attributed to β-cell dedifferentiation and/or death. In recent years, it has been proposed that circulating epigenetically modified DNA fragments arising from β cells might be able to report on the potential occurrence of β-cell death in diabetes. Here, we review published literature of DNA-based β-cell death biomarkers that have been evaluated in human cohorts of islet transplantation, type 1 diabetes, and obesity and type 2 diabetes. In addition, we provide new data on the applicability of one of these biomarkers (cell free unmethylated INS DNA) in adult cohorts across a spectrum from obesity to T2D, in which no significant differences were observed, and compare these findings to those previously published in youth cohorts where differences were observed. Our analysis of the literature and our own data suggest that β-cell death may occur in subsets of individuals with obesity and T2D, however a more sensitive method or refined study designs are needed to provide better alignment of sampling with disease progression events.  相似文献   

7.
The increasing prevalence of metabolic syndrome-related diseases, including type-2 diabetes and obesity, makes it urgent to develop new alternative therapies, such as probiotics. In this study, we have used Caenorhabditis elegans under a high-glucose condition as a model to examine the potential probiotic activities of Pediococcus acidilactici CECT9879 (pA1c). The supplementation with pA1c reduced C. elegans fat accumulation in a nematode growth medium (NGM) and in a high-glucose (10 mM) NGM medium. Moreover, treatment with pA1c counteracted the effect of the high glucose by reducing reactive oxygen species by 20%, retarding the aging process and extending the nematode median survival (>2 days in comparison with untreated control worms). Gene expression analyses demonstrated that the probiotic metabolic syndrome-alleviating activities were mediated by modulation of the insulin/IGF-1 signaling pathway (IIS) through the reversion of the glucose-nuclear-localization of daf-16 and the overexpression of ins-6 and daf-16 mediators, increased expression of fatty acid (FA) peroxisomal β-oxidation genes, and downregulation of FA biosynthesis key genes. Taken together, our data suggest that pA1c could be considered a potential probiotic strain for the prevention of the metabolic syndrome-related disturbances and highlight the use of C. elegans as an appropriate in vivo model for the study of the mechanisms underlying these diseases.  相似文献   

8.
Long non-coding RNA steroid receptor RNA activators (LncRNA SRAs) are implicated in the β-cell destruction of Type 1 diabetes mellitus (T1D), but functional association remains poorly understood. Here, we aimed to verify the role of LncRNA SRA regulation in β-cells. LncRNA SRAs were highly expressed in plasma samples and peripheral blood mononuclear cells (PBMCs) from T1D patients. LncRNA SRA was strongly upregulated by high-glucose treatment. LncRNA SRA acts as a microRNA (miR)-146b sponge through direct sequence–structure interactions. Silencing of lncRNA SRA increased the functional genes of Tregs, resulting in metabolic reprogramming, such as decreased lactate levels, repressed lactate dehydrogenase A (LDHA)/phosphorylated LDHA (pLDHA at Tyr10) expression, decreased reactive oxygen species (ROS) production, increased ATP production, and finally, decreased β-cell apoptosis in vitro. There was a positive association between lactate level and hemoglobin A1c (HbA1c) level in the plasma from patients with T1D. Recombinant human interleukin (IL)-2 treatment repressed lncRNA SRA expression and activity in β-cells. Higher levels of lncRNA-SRA/lactate in the plasma are associated with poor regulation in T1D patients. LncRNA SRA contributed to T1D pathogenesis through the inhibition of miR-146b in β-cells, with activating signaling transduction of interleukin-1 receptor-associated kinase 1 (IRAK1)/LDHA/pLDHA. Taken together, LncRNA SRA plays a critical role in the function of β-cells.  相似文献   

9.
The entrocytes of the small intestine can only absorb monosaccharides such as glucose and fructose from our diet. The intestinal absorption of dietary carbohydrates such as maltose and sucrose is carried out by a group of α-glucosidases. Inhibition of these enzymes can significantly decrease the postprandial increase of blood glucose level after a mixed carbohydrate diet. Therefore, the inhibitory activity of Omija (Schizandra chinensis) extract against rat intestinal α-glucosidase and porcine pancreatic α-amylase were investigated in vitro and in vivo. The in vitro inhibitory activities of water extract of Omija pulp/skin (OPE) on α-glucosidase and α-amylase were potent when compared to Omija seeds extract (OSE). The postprandial blood glucose lowering effect of Omija extracts was compared to a known type 2 diabetes drug (Acarbose), a strong α-glucosidase inhibitor in the Sprague-Dawley (SD) rat model. In rats fed on sucrose, OPE significantly reduced the blood glucose increase after sucrose loading. Furthermore, the oxygen radical absorbance capacity (ORAC) of OSE and OPE was evaluated. OPE had higher peroxyl radical absorbing activity than OSE. These results suggest that Omija, which has high ORAC value with α-glucosidase inhibitory activity and blood glucose lowering effect, could be physiologically useful for treatment of diabetes, although clinical trials are needed.  相似文献   

10.
A huge effort has been devoted to developing drugs targeting integrins over 30 years, because of the primary roles of integrins in the cell-matrix milieu. Five αv-containing integrins, in the 24 family members, have been a central target of fibrosis. Currently, a small molecule against αvβ1 is undergoing a clinical trial for NASH-associated fibrosis as a rare agent aiming at fibrogenesis. Latent TGFβ activation, a distinct talent of αv-integrins, has been intriguing as a therapeutic target. None of the αv-integrin inhibitors, however, has been in the clinical market. αv-integrins commonly recognize an Arg-Gly-Asp (RGD) sequence, and thus the pharmacophore of inhibitors for the 5-integrins is based on the same RGD structure. The RGD preference of the integrins, at the same time, dilutes ligand specificity, as the 5-integrins share ligands containing RGD sequence such as fibronectin. With the inherent little specificity in both drugs and targets, “disease specificity” has become less important for the inhibitors than blocking as many αv-integrins. In fact, an almighty inhibitor for αv-integrins, pan-αv, was in a clinical trial. On the contrary, approved integrin inhibitors are all specific to target integrins, which are expressed in a cell-type specific manner: αIIbβ3 on platelets, α4β1, α4β7 and αLβ2 on leukocytes. Herein, “disease specific” integrins would serve as attractive targets. α8β1 and α11β1 are selectively expressed in hepatic stellate cells (HSCs) and distinctively induced upon culture activation. The exceptional specificity to activated HSCs reflects a rather “pathology specific” nature of these new integrins. The monoclonal antibodies against α8β1 and α11β1 in preclinical examinations may illuminate the road to the first medical agents.  相似文献   

11.
Type 1 diabetes (T1D) is caused by the destruction of β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective treatment for T1D. However, the survival of islet grafts is often disrupted by recurrent autoimmunity. Alpha-lipoic acid (ALA) has been reported to have immunomodulatory effects and, therefore, may have therapeutic potential in the treatment of T1D. In this study, we investigated the therapeutic potential of ALA in autoimmunity inhibition. We treated non-obese diabetic (NOD) mice with spontaneous diabetes and islet-transplantation mice with ALA. The onset of diabetes was decreased and survival of the islet grafts was extended. The populations of Th1 cells decreased, and regulatory T cells (Tregs) increased in ALA-treated mice. The in vitro Treg differentiation was significantly increased by treatment with ALA. The adoptive transfer of ALA-differentiated Tregs into NOD recipients improved the outcome of the islet grafts. Our results showed that in vivo ALA treatment suppressed spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Tregs. Our study also demonstrated the therapeutic potential of ALA in Treg-based cell therapies and islet transplantation used in the treatment of T1D.  相似文献   

12.
Idiopathic pulmonary fibrosis (IPF) is a chronic devastating disease with poor prognosis. Multiple pathological processes, including inflammation, epithelial mesenchymal transition (EMT), apoptosis, and oxidative stress, are involved in the pathogenesis of IPF. Recent findings suggested that nuclear factor-κB (NF-κB) is constitutively activated in IPF and acts as a central regulator in the pathogenesis of IPF. The aim of our study was to reveal the value of andrographolide on bleomycin-induced inflammation and fibrosis in mice. The indicated dosages of andrographolide were administered in mice with bleomycin-induced pulmonary fibrosis. On day 21, cell counts of total cells, macrophages, neutrophils and lymphocytes, alone with TNF-α in bronchoalveolar lavage fluid (BALF) were measured. HE staining and Masson’s trichrome (MT) staining were used to observe the histological alterations of lungs. The Ashcroft score and hydroxyproline content of lungs were also measured. TGF-β1 and α-SMA mRNA and protein were analyzed. Activation of NF-κB was determined by western blotting and electrophoretic mobility shift assay (EMSA). On day 21 after bleomycin stimulation, andrographolide dose-dependently inhibited the inflammatory cells and TNF-α in BALF. Meanwhile, our data demonstrated that the Ashcroft score and hydroxyproline content of the bleomycin-stimulated lung were reduced by andrographolide administration. Furthermore, andrographloide suppressed TGF-β1 and α-SMA mRNA and protein expression in bleomycin-induced pulmonary fibrosis. Meanwhile, andrographolide significantly dose-dependently inhibited the ratio of phospho-NF-κB p65/total NF-κB p65 and NF-κB p65 DNA binding activities. Our findings indicate that andrographolide compromised bleomycin-induced pulmonary inflammation and fibrosis possibly through inactivation of NF-κB. Andrographolide holds promise as a novel drug to treat the devastating disease of pulmonary fibrosis.  相似文献   

13.
Poor glycemic control and dyslipidemia are hallmarks of type 2 diabetes mellitus (T2DM), which predispose to cardiovascular diseases. Peroxisome proliferator-activated receptor-α (PPARα) has been associated with atherosclerosis, but its role in T2DM is less clear. Previously, we studied PPARα expression levels in diabetics with and without dyslipidemia (DD). In this study we described the association with fasting blood glucose, HbA1c levels and lipid levels of the study population. Patient demography and biochemical data were collected from hospitals in Islamabad, Pakistan, and RT-PCR data of PPARα expression were retrieved from our previous study from the same cohort. We performed t-tests and regression analysis to evaluate the relationships between PPARα expression and demographic and clinical variables. As expected, body mass index and HbA1c were elevated in T2DM and DD patients compared to controls. Blood lipids (total cholesterol, triglycerides, LDL and HDL) were significantly higher in the DD group compared to the other two groups. In the T2DM and DD groups, the PPARα expression was not associated with any of the physical and biochemical parameters measured in this study. Expression of the PPARα gene was independent of blood lipids and glycemic control in this study. Further research is necessary to better understand the biological parameters of PPARα expression.  相似文献   

14.
Hepatocellular carcinoma (HCC) is a male-oriented malignancy; its progression is affected by sex hormones. 17α-ethinylestradiol (EE2) is a synthetic estrogen widely used as an oral contraceptive; however, it is unknown whether EE2 regulates sex hormone action in HCC. We investigated whether EE2 influences HCC risk in male androgenic environments, using mice expressing human sex hormone-binding globulin (SHBG). Two-week-old male mice were injected with diethyl-nitrosamine (DEN, 25 mg/kg) and fed an EE2 diet for 10 weeks from 30 weeks of age. Development and characteristics of liver cancer were evaluated in 40-week-old mice via molecular and histological analyses. Although EE2 did not increase HCC progression in wild-type mice, SHBG mice exhibited remarkably higher HCC risk when fed EE2. The livers of EE2-treated SHBG mice exhibited substantially increased pro-inflammatory necrosis with high plasma levels of ALT and HMGB1, and intrahepatic injury and fibers. Additionally, increased androgen response and androgen-mediated proliferation in the livers of EE2-treated SHBG mice and EE2-exposed hepatocytes under SHBG conditions were observed. As a competitor of SHBG-androgen binding, EE2 could bind with SHBG and increase the bioavailability of androgen. Our results revealed that EE2 is a novel risk factor in androgen-dominant men, predisposing them to HCC risk.  相似文献   

15.
Pulmonary fibrosis is a progressive and fatal disorder characterized by dysregulated repair after recurrent injury. Destruction of the lung architecture with excess extracellular matrix deposition induces respiratory failure with hypoxia and progressive dyspnea. The impact of hypoxia on pulmonary endothelial cells during pulmonary fibrogenesis is unclear. Using a magnetic-activated cell sorting system, pulmonary endothelial cells were isolated from a mouse model of pulmonary fibrosis induced by intratracheally administered bleomycin. When endothelial cells were exposed to hypoxic conditions, a hypoxia-inducible factor (HIF)-2α protein was detected in CD31- and α-smooth muscle actin (SMA)-positive cells. Levels of plasminogen activator inhibitor 1, von Willebrand factor, and matrix metalloproteinase 12 were increased in endothelial cells isolated from bleomycin-treated mice exposed to hypoxic conditions. When endothelial cells were cultured under hypoxic conditions, levels of fibrotic mediators, transforming growth factor-β and connective tissue growth factor, were elevated only in endothelial cells from bleomycin-treated and not from saline-treated lungs. The increased expression of α-SMA and mesenchymal markers and collagen production in bleomycin- or hypoxia-stimulated endothelial cells were further elevated in endothelial cells from bleomycin-treated mouse lungs cultured under hypoxic conditions. Exposure to hypoxia damaged endothelial cells and enhanced fibrogenesis-related damage in bleomycin-treated pulmonary endothelial cells.  相似文献   

16.
Integrins are necessary for cell adhesion, migration, and positioning. Essential for inducing signalling events for cell survival, proliferation, and differentiation, they also trigger a variety of signal transduction pathways involved in mediating invasion, metastasis, and squamous-cell carcinoma. Several recent studies have demonstrated that the up- and down-regulation of the expression of αv and other integrins can be a potent marker of malignant diseases and patient prognosis. This review focuses on an arginine-glycine-aspartic acid (RGD)-dependent integrin αVβ6, its biology, and its role in healthy humans. We examine the implications of αVβ6 in cancer progression and the promotion of epithelial-mesenchymal transition (EMT) by contributing to the activation of transforming growth factor beta TGF-β. Although αvβ6 is crucial for proper function in healthy people, it has also been validated as a target for cancer treatment. This review briefly considers aspects of targeting αVβ6 in the clinic via different therapeutic modalities.  相似文献   

17.
Background: α-cyclodextrin (α-CD) is one of the dietary fibers that may have a beneficial effect on cholesterol and/or glucose metabolism, but its efficacy and mode of action remain unclear. Methods: In the present study, we examined the anti-hyperglycemic effect of α-CD after oral loading of glucose and liquid meal in mice. Results: Administration of 2 g/kg α-CD suppressed hyperglycemia after glucose loading, which was associated with increased glucagon-like peptide 1 (GLP-1) secretion and enhanced hepatic glucose sequestration. By contrast, 1 g/kg α-CD similarly suppressed hyperglycemia, but without increasing secretions of GLP-1 and insulin. Furthermore, oral α-CD administration disrupts lipid micelle formation through its inclusion of lecithin in the gut luminal fluid. Importantly, prior inclusion of α-CD with lecithin in vitro nullified the anti-hyperglycemic effect of α-CD in vivo, which was associated with increased intestinal mRNA expressions of SREBP2-target genes (Ldlr, Hmgcr, Pcsk9, and Srebp2). Conclusions: α-CD elicits its anti-hyperglycemic effect after glucose loading by inducing lecithin inclusion in the gut lumen and activating SREBP2, which is known to induce cholecystokinin secretion to suppress hepatic glucose production via a gut/brain/liver axis.  相似文献   

18.
Systemic inflammation, from gut translocation of organismal molecules, might worsen uremic complications in acute kidney injury (AKI). The monitoring of gut permeability integrity and/or organismal molecules in AKI might be clinically beneficial. Due to the less prominence of Candida albicans in human intestine compared with mouse gut, C. albicans were orally administered in bilateral nephrectomy (BiN) mice. Gut dysbiosis, using microbiome analysis, and gut permeability defect (gut leakage), which was determined by fluorescein isothiocyanate-dextran and intestinal tight-junction immunofluorescent staining, in mice with BiN-Candida was more severe than BiN without Candida. Additionally, profound gut leakage in BiN-Candida also resulted in gut translocation of lipopolysaccharide (LPS) and (1→3)-β-D-glucan (BG), the organismal components from gut contents, that induced more severe systemic inflammation than BiN without Candida. The co-presentation of LPS and BG in mouse serum enhanced inflammatory responses. As such, LPS with Whole Glucan Particle (WGP, a representative BG) induced more severe macrophage responses than LPS alone as determined by supernatant cytokines and gene expression of downstream signals (NFκB, Malt-1 and Syk). Meanwhile, WGP alone did not induced the responses. In parallel, WGP (with or without LPS), but not LPS alone, accelerated macrophage ATP production (extracellular flux analysis) through the upregulation of genes in mitochondria and glycolysis pathway (using RNA sequencing analysis), without the induction of cell activities. These data indicated a WGP pre-conditioning effect on cell energy augmentation. In conclusion, Candida in BiN mice accelerated gut translocation of BG that augmented cell energy status and enhanced pro-inflammatory macrophage responses. Hence, gut fungi and BG were associated with the enhanced systemic inflammation in acute uremia.  相似文献   

19.
The studies were performed to investigate the physiological characteristics of non-obese diabetic (NOD) mice treated with FTY720. At the age of 12 weeks, each mouse was fed with FTY720 or physiological saline once a day for 10 weeks running, and their blood glucose, weight, anti-GAD antibody and organ indexes were determined. No mouse in group FTY720 (NOD mice treated with FTY720) showed diabetic symptoms. The average content of serum anti-GAD antibody in group FTY720 decreased 48.75% (P < 0.01). It was concluded that the spleen, kidney and liver of NOD mice treated with FTY720 shriveled significantly in the progression of diabetes (P < 0.01 or P < 0.05). The body weight of group FTY720 mice was slightly lower than that of the model control (MC) group and these two groups both had less body weight than the normal control (NC) group (P < 0.01). The result of tests of anti-GAD antibody suggested that FTY720 treatment could suppress the anti-GAD response.  相似文献   

20.
The casein kinase 1 enzymes (CK1) form a family of serine/threonine kinases with seven CK1 isoforms identified in humans. The most important substrates of CK1 kinases are proteins that act in the regulatory nodes essential for tumorigenesis of hematological malignancies. Among those, the most important are the functions of CK1s in the regulation of Wnt pathways, cell proliferation, apoptosis and autophagy. In this review we summarize the recent developments in the understanding of biology and therapeutic potential of the inhibition of CK1 isoforms in the pathogenesis of chronic lymphocytic leukemia (CLL), other non-Hodgkin lymphomas (NHL), myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and multiple myeloma (MM). CK1δ/ε inhibitors block CLL development in preclinical models via inhibition of WNT-5A/ROR1-driven non-canonical Wnt pathway. While no selective CK1 inhibitors have reached clinical stage to date, one dual PI3Kδ and CK1ε inhibitor, umbralisib, is currently in clinical trials for CLL and NHL patients. In MDS, AML and MM, inhibition of CK1α, acting via activation of p53 pathway, showed promising preclinical activities and the first CK1α inhibitor has now entered the clinical trials.  相似文献   

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