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1.
Background/ObjectiveMembrane flexibility can be a determining factor in pathophysiological mechanisms of type 2 diabetes (T2D). As a cofactor of delta-5 desaturase (D5D) and delta-6 desaturase (D6D), and gene expression regulator, zinc may play a role modulating membrane flexibility by increasing membrane polyunsaturated fatty acids (PUFA) abundance. The objective of this study was to evaluate the effect of a 24-month zinc supplementation (30 mg elemental zinc) on membrane fatty acid composition in patients with T2D.Subjects/methodsSixty patients with T2D were evaluated. Thirty were randomly assigned to the zinc supplemented group and thirty to the placebo group. Fatty acid composition in red blood cell (RBC) membranes was determined by gas chromatography. Expression of gene encoding for D5D (FADS1), and D6D (FADS2) were evaluated in peripheral blood mononuclear cells by real-time polymerase chain reaction.ResultsAfter 24 months of supplementation, a greater abundance of docosapentaenoic acid (C22:5 n-3), arachidonic acid (C20:4 n-6), adrenic acid (C22:4 n-6), and total n-6 PUFA was found (p = 0.001, p = 0.007, p = 0.033, p = 0.048, respectively). The unsaturated fatty acids/saturated fatty acids ratio, and unsaturation index was increased in the zinc supplemented group at month 24 (p = 0.003 and p = 0.000, respectively). FADS1 gene was upregulated in the zinc group in relation to placebo at month 12 (p = 0.020).ConclusionsSupplementation with 30 mg/d elemental zinc during 24 months in patients with T2D had an effect on the composition of RBC membranes increasing PUFA abundance and in turn, improving membrane flexibility. This effect may be mediated by induction of D5D gene expression.  相似文献   

2.
Red blood cells (RBCs) contain large amounts of iron and operate in highly oxygenated tissues. As a result, these cells encounter a continuous oxidative stress. Protective mechanisms against oxidation include prevention of formation of reactive oxygen species (ROS), scavenging of various forms of ROS, and repair of oxidized cellular contents. In general, a partial defect in any of these systems can harm RBCs and promote senescence, but is without chronic hemolytic complaints. In this review we summarize the often rare inborn defects that interfere with the various protective mechanisms present in RBCs. NADPH is the main source of reduction equivalents in RBCs, used by most of the protective systems. When NADPH becomes limiting, red cells are prone to being damaged. In many of the severe RBC enzyme deficiencies, a lack of protective enzyme activity is frustrating erythropoiesis or is not restricted to RBCs. Common hereditary RBC disorders, such as thalassemia, sickle-cell trait, and unstable hemoglobins, give rise to increased oxidative stress caused by free heme and iron generated from hemoglobin. The beneficial effect of thalassemia minor, sickle-cell trait, and glucose-6-phosphate dehydrogenase deficiency on survival of malaria infection may well be due to the shared feature of enhanced oxidative stress. This may inhibit parasite growth, enhance uptake of infected RBCs by spleen macrophages, and/or cause less cytoadherence of the infected cells to capillary endothelium.  相似文献   

3.
Abstract

Oxidative stress is implicated in the pathogenesis and complications of type 2 diabetes mellitus (NIDDM). Glycoxidation may damage the enzymes that synthesise glutathione (GSH), an endogenous intracellular antioxidant. Erythrocytes (RBCs) taken from NIDDM subjects, and non-diabetic controls, were GSH-depleted using 1-chloro-2,4-dinitrobenzene, incubated in a solution containing GSH-rebuilding substrates, and sampled for GSH using a 5,5′-γ-dithiobis-(2-nitrobenzoic acid)/enzymatic recycling procedure. NIDDM subjects, on average, had the same GSH concentration and synthesising ability as non-diabetic controls, indicating normal function of the synthesis enzymes. A positive correlation between synthesis and concentration of GSH seen in non-diabetic controls did not exist in NIDDM, due to their putatively larger oxidative load. The results, to the best of our knowledge, provide the first evidence that, despite a higher oxidative load, intact RBCs from NIDDM subjects are able to synthesise GSH normally. It is hypothesised that increased rates of GSH synthesis would maintain a normal steady-state GSH concentration.  相似文献   

4.
ATP release from erythrocytes in response to low oxygen tension requires an increase in cAMP, the level of which is regulated by phosphodiesterase 3 (PDE3). Such release is defective in erythrocytes of humans with type 2 diabetes (DM2). This study tested a hypothesis that direct delivery of the clinically useful PDE3 inhibitor, cilostazol, to erythrocytes of humans with type 2 diabetes using liposomes would restore low-oxygen tension-induced ATP release. Cilostazol was incorporated into liposomes prepared from dimyristoylphosphatidylcholine (DMPC). Liposome-delivery of cilostazol restored ATP release from DM2 erythrocytes to levels which were not different from that released from non-cilostazol treated healthy erythrocytes under the same conditions. There were no observed adverse effects of the liposomes on either healthy or DM2 erythrocytes. The directed liposomal delivery of PDE inhibitors to erythrocytes may help prevent or slow the development of peripheral vascular disease in individuals with DM2 by restoring an important physiological controller of microvascular perfusion while minimizing side effects associated with systemic delivery of some of these inhibitors.  相似文献   

5.
Doxorubicin (DOX) and idarubicin (IDA) are anthracycline antibiotics, widely used in human cancer treatment. The present study addressed the effects of these two drugs on lipid bilayer fluidity, protein conformation and microviscosity in erythrocytes from acute myeloid leukaemia patients, using electron spin resonance (ESR) spectroscopy and fluorescence measurements. Only DOX caused statistically significant changes in the parameters examined. Within 30 min of drug injection, changes were observed in the fluidity of the hydrophobic parts of the lipid bilayer and erythrocyte membrane protein conformation. These changes persisted for up to 24h. Analysis of the EPR Tempamine spectrum also showed that the microviscosity of the erythrocyte interior increased during the early stages of the drug effect. Idarubicin, in contrast, caused no identifiable change in any of the parameters studied and therefore seems to be safe for erythrocytes. We conclude that IDA is markedly less toxic than DOX to erythrocytes from acute myeloid leukaemia patients.  相似文献   

6.
7.
Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. The aim of this study was to investigate the effect of ethanolic extract of Eugenia jambolana seed kernel on antioxidant defense systems of plasma and pancreas in streptozotocin-induced diabetes in rats. The levels of glucose, vitamin-C, vitamin-E, ceruloplasmin, reduced glutathione and lipidperoxides were estimated in plasma of control and experimental groups of rats. The levels of lipidperoxides, reduced glutathione and activities of superoxide dismutase, catalase and glutathione peroxidase were assayed in pancreatic tissue of control and experimental groups of rats. A significant increase in the levels of plasma glucose, vitamin-E, ceruloplasmin, lipid peroxides and a concomitant decrease in the levels of vitamin-C, reduced glutathione were observed in diabetic rats. The activities of pancreatic antioxidant enzymes were altered in diabetic rats. These alterations were reverted back to near normal level after the treatment with Eugenia jambolana seed kernel and glibenclamide. Histopathological studies also revealed that the protective effect of Eugenia jambolana seed kernel on pancreatic beta-cells. The present study shows that Eugenia jambolana seed kernel decreased oxidative stress in diabetic rats, which inturn may be due to its hypoglycemic property.  相似文献   

8.
As an essential nutrient involved in carbohydrate and lipid metabolism, chromium is of extraordinary importance for patients with diabetes. Plasma concentrations do not reflect the chromium supply; thus, we determined the element’s content in blood cells in order to evaluate the body status. We investigated 86 blood donors (C) and 35 diabetics type 2 (Dm2). After the isolation of the blood cells by using a density centrifugation, the chromium concentrations were determined by electrothermal atomic absorption spectrometry. Compared to C, Dm2 had higher values in plasma, erythrocytes, and platelets (248%, 61%, and 91%, respectively) and lower contents in polymorphonuclear and mononuclear leukocytes (each −35%, age- and sex-matched groups with n=35, each p<0.01). The poorer the metabolic control assessed by HbA1c, the higher were the chromium concentrations in plasma (r=+0.46, n=33, p=0.007, increase 11.1% per %HbA1c) and the lower were the values in mononuclear leukocytes (r=−0.45, n=33, p=0.008, decrease 17.8% per %HbA1c). The changed amounts in plasma and in mononuclear cells in increasing hyperglycemia could be the result of an intracellular/extracellular redistribution of the element. High plasma levels might explain the renal chromium losses of diabetics, whereas the lymphocytes could reflect a decreasing chromium body state.  相似文献   

9.
Exposure of cells to hyperthermia is known to induce apoptosis, although the underlying mechanisms are only partially understood. Here, we examine the molecular requirements necessary for heat-induced apoptosis using genetically modified Jurkat T-lymphocytes. Cells stably overexpressing Bcl-2/Bcl-x(L) or stably depleted of Apaf-1 were completely resistant to heat-induced apoptosis, implicating the involvement of the mitochondria-mediated pathway. Pretreatment of wild-type cells with the cell-permeable biotinylated general caspase inhibitor b-VAD-fmk (biotin-Val-Ala-Asp(OMe)-CH(2)F) both inhibited heat-induced apoptosis and affinity-labeled activated initiator caspase-2, -8, and -9. Despite this finding, however, cells engineered to be deficient in caspase-8, caspase-2, or the caspase-2 adaptor protein RAIDD (receptor-interacting protein (RIP)-associated Ich-1/CED homologous protein with death domain) remained susceptible to heat-induced apoptosis. Additionally, b-VAD-fmk failed to label any activated initiator caspase in Apaf-1-deficient cells exposed to hyperthermia. Cells lacking Apaf-1 or the pro-apoptotic BH3-only protein Bid exhibited lower levels of heat-induced Bak activation, cytochrome c release, and loss of mitochondrial membrane potential, although cleavage of Bid to truncated Bid (tBid) occurred downstream of caspase-9 activation. Combined, the data suggest that caspase-9 is the critical initiator caspase activated during heat-induced apoptosis and that tBid may function to promote cytochrome c release during this process as part of a feed-forward amplification loop.  相似文献   

10.
Oxidative stress and oxidative damage to tissues are common end points of chronic diseases such as atherosclerosis, diabetes, and rheumatoid arthritis. Oxidative stress in diabetes coexists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. The aim of the present study was to evaluate the possible protective effects of Murraya koenigii leaves extract against beta-cell damage and antioxidant defense systems of plasma and pancreas in streptozotocin induced diabetes in rats. The levels of glucose and glycosylated hemoglobin in blood and insulin, Vitamin C, Vitamin E, ceruloplasmin, reduced glutathione and TBARS were estimated in plasma of control and experimental groups of rats. To assess the changes in the cellular antioxidant defense system such as the level of reduced glutathione and activities of superoxide dismutase, catalase and glutathione peroxidase were assayed in pancreatic tissue homogenate. The levels of glucose, glycosylated hemoglobin, insulin, TBARS, enzymatic and non-enzymatic antioxidants were altered in diabetic rats. These alterations were reverted back to near control levels after the treatment of M. koenigii leaves extract. Transmission electron microscopic studies also revealed the protective nature of M. koenigii leaves on pancreatic beta-cells. These findings suggest that M. koenigii treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and pancreatic beta-cell damage. The antioxidant effect of the M. koenigii extract was compared with glibenclamide, a well-known hypoglycemic drug.  相似文献   

11.
Human blood plasma chitotriosidase (CHIT1) is a glycoprotein with chitinolytic activity with not fully elucidated biological function. Its increased level is observed in type 2 diabetes mellitus (T2DM) and is associated with development of diabetic complications. The CHIT1 glycosylation profile and degree is still poorly studied and never investigated in T2DM. Therefore the aim of the present study was to examine the association between glycosylation profile and degree and diabetes with accompanying nephropathy. In blood plasma of 28 patients with T2DM and 11 healthy subjects the CHIT1 concentration and specific activity were examined. The profile and degree of CHIT1 glycosylation were determined by lectin-ELISA using lectins specific to O-glycans (Jacalin, MPL, VVL) and sialo-specific SNA and MAA. We revealed that both concentration and specific activity of CHIT1 significantly increased in T2DM, especially in nephropathy with elevated albuminuria. The relative reactivities with lectins, except Jacalin, decreased progressively with T2DM occurrence and albuminuria progression. The most significant differences were observed between control vs. albuminuric group (Micro and Macro). It is also possible that the observed differences in immunoblotting pattern in molecular masses of CHIT1 bands between T2DM patients and healthy subjects may be caused by the differences in degree of CHIT1 glycosylation. The analysis of CHIT1 glycosylation status and the determination of CHIT1 concentration together with its enzymatic activity in blood plasma might constitute additional valuable diagnosis tools for the evaluation the T2DM patients with accompanying nephropathy. Extension of the lectin panel specific to O-glycans occurs useful for the further research using microarray formats, which are expected to accelerate “lectin-based glycan profiling” of glycoproteins.  相似文献   

12.
Using reversed-phase high-performance liquid chromatography purine nucleotides, nucleosides and nucleobases as well as pyridine nucleotides were determined in extracts of reticulocytes and mature red blood cells of rabbits. The concentrations of almost all compounds measured decrease during the last phase of red blood cell maturation. These changes were interpreted with respect to the loss of mitochondria, accompanied by shifting the energy production from the preferentially oxidative mode to the exclusively glycolytic one and variations in the concentrations of purine compounds in blood plasma during reticulocytosis.  相似文献   

13.
Decreased GLUT4 expression and impaired GLUT4 cell membrane translocation are involved in type 2 diabetes mellitus (T2DM) pathogenesis so the factors impacting GLUT4 expression may be associated with T2DM. In this study, we identified four miRNAs: miR-31, miR-93, miR-146a, and miR-199a which suppress GLUT4 expression in HEK293T cells. Subsequently, we determined expression of these four miRNAs in plasma samples of T2DM patients, T2DM susceptible individuals, and healthy controls and found miR-199a was overexpressed in patients’ plasma compared with healthy control. Because the miR-199a binding site in GLUT4 3′UTR is highly conserved among vertebrates, we detected the glucose uptake in rat L6 myoblast cells through gain- and loss-of-function of miR-199a. We found that miR-199a can repress glucose uptake in L6 cells, which was rescued by GLUT4 overexpression. These results indicate that T2DM patients may have a high level miR-199a that reduce GLUT4 expression and contribute to the insulin resistance. Hence, miR-199a may be a novel biomarker for risk estimation and classification in T2DM patients.  相似文献   

14.
Abstract

Objectives

The presence of inflammatory cells indicates the development of epithelial cell injury in nasal polyposis (NP) and the potential for production of high levels of reactive oxygen and nitrogen species. The aim of our study was to clarify the role of oxidative stress and antioxidant status in the deterioration accompanying NP.

Methods

Twenty patients (11 men) aged 47.2 ± 17.0 years with nasal polyps were included in the study. Twenty healthy subjects (7 men) aged 48.2 ± 15.3 years formed the control group. The erythrocyte activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and plasma nitric oxide (NO) concentrations were measured. An alkaline comet assay was used to determine the extent of blood lymphocyte DNA damage of oxidized purines as glicosylo-formamidoglicosylase (Fpg) sites, and oxidized pyrimidines as endonuclease III (Nth) sites.

Results

A significant increase of NO (P < 0.05) and non-significant decreases of SOD (P > 0.05), CAT (P > 0.05), and GPx (P > 0.05) were seen in NP patients compared to healthy controls. The level of blood lymphocyte oxidative DNA damage in NP patients was significantly higher compared to the control group (P = 0.01).

Discussion

The blood lymphocyte DNA damage level increased in patients with NP. Elevated DNA damage may be related to overproduction of reactive oxygen and nitrogen species and/or decreased antioxidant protection.  相似文献   

15.
Red blood cell (RBC) susceptibility to oxidative and osmotic stress in vitro was investigated in cells from trained and untrained men before and after submaximal exercise. Whilst no significant change in peroxidative haemolysis occurred immediately after 1 h of cycling at 60% of maximal aerobic capacity ( max), a 20% increase was found 6 h later in both groups (P<0.05). The RBC osmotic fragility decreased by 15% immediately after exercise (P<0.001) and this was maintained for 6 h (Ps<0.001). There was an associated decrease in mean cell volume (P<0.05). Training decreased RBC susceptibility to peroxidative haemolysis (P<0.025) but it did not influence any other parameter. These exercise-induced changes were smaller in magnitude but qualitatively similar to those found in haemopathological states involving haem-iron incorporation into membrane lipids and the short-circuiting of antioxidant protection. To explore this similarity, a more strenuous and mechanically stressful exercise test was used. Running at 75% max for 45 min reduced the induction time of O2 uptake (peroxidation), consistent with reduced antioxidation capacity, and increased the maximal rate of O2 uptake in RBC challenged with cumene hydroperoxide (P<0.001). The proportion of high-density RBC increased by 10% immediately after running (P<0.001) but no change in membrane-incorporated haem-iron occurred. In contrast, treatment of RBC with oxidants (20–50 mol·l–1 in vitro increased cell density and membrane incorporation of haem-iron substantially. These results showed that single episodes of submaximal exercise caused significant changes in RBC susceptibility to oxidative and osmotic stress. Such responses may account for the increase in RBC turnover found in athletes undertaking strenuous endurance training.  相似文献   

16.

AIMS:

The aim of this study was to investigate the association between haptoglobin (Hp) phenotypes and risk of the development of diabetic retinopathy (DR) in patients of type 2 diabetes mellitus.

MATERIALS AND METHODS:

This cross-sectional study included 45 normotensive type 2 diabetic patients (duration more than 5 years) admitted in the hospital divided into two groups (with and without DR) on the basis of fundus examination by direct ophthalmoscopy. Serum samples of all patients were subjected for Hp phenotyping by polyacrylamide gel electrophoresis.

RESULTS:

DR was associated significantly in diabetic patients with Hp2-2 phenotype (79.31%) than diabetic patients with Hp2-1 phenotype (43.75%) and Hp2-2 had higher odds ratio (OR) for DR in univariate analysis (OR 4.929, [95% confidence interval [CI] (1.297-18.733)], P = 0.016) and multivariate analysis (OR 7.704 [95% CI (0.887-66.945)], P = 0.064). Furthermore, Hp2-2 was associated significantly with severe forms of DR.

CONCLUSION:

Hp2-2 phenotype is associated with susceptibility to DR showing a graded risk relationship to the number of Hp2 alleles. Determination of Hp phenotype may be useful in the risk assessment and management of DR.  相似文献   

17.
The type I inositol 1,4,5-trisphosphate (IP(3)) receptor is selectively down-regulated in several neurodegenerative diseases, including Alzheimer's disease, Huntington's chorea, and ischemia, all conditions in which apoptotic neuronal loss occurs. In the present study, we used a neuronal cell line, human neuroblastoma SH-SY5Y cells, to investigate whether the levels of IP(3) receptor are changed during apoptosis in these cells. Following induction of apoptosis by staurosporine, the immunoreactivity of the type I IP(3) receptor in microsome preparations from SH-SY5Y cells was reduced within 2 h, with a further reduction during subsequent hours. Immunoblot analyses, using antibodies to poly(ADP-ribose) polymerase and spectrin breakdown products, revealed proteolysis of these caspase-3 substrates within 3 h, confirming that IP(3) receptor cleavage is an early consequence of apoptosis. In vitro incubation of SH-SY5Y microsomes or immunopurified IP(3) receptor from rat cerebellum with recombinant caspase-3 led to generation of immunoreactive breakdown products similar to those observed in intact cells, suggesting that the type I IP(3) receptor is a potential substrate for caspase-3. Preincubation of the neuroblastoma cells with the caspase-3 inhibitor Z-Asp-Glu-Val-Asp-fluoromethyl ketone prevented IP(3) receptor degradation. These results show that the type I IP(3) receptor is a substrate for caspase-3 in neuronal cells and indicate that apoptotic down-regulation of IP(3) receptor levels may contribute to the pathology of neurodegenerative conditions.  相似文献   

18.
目的:探讨2型糖尿病(T2DM)患者幽门螺杆菌(HP)感染与超敏c反应蛋白(hs-CRP)、血脂水平的关系。方法:以2009年1月1日至2009年12月31日在我院体检的683例2型糖尿病患者为研究对象,根据HP感染情况分成HP阳性组(n=306)和HP阴性组(n=377),采用单因素和多因素Logistic回归分析方法,分析HP感染与hs-CRP、血脂水平的关系。结果:(1)HP阳性组的hs-CRP水平高于HP阴性组(1.14mg/L vs 0.96mg/L),差异有统计学意义(P<0.05)。(2)HP阳性组的血脂异常率(59.8%vs 50.7%)和hs-CRP异常率(20.9%vs 14.3%)均高于HP阴性组,差异均有统计学意义(均P<0.05)。(3)单因素Logistic回归分析显示,血脂异常和hs-CRP异常对HP阳性的OR值及分别为1.449和1.582,均有统计学意义(均P<0.05),多因素Logistic回归分析显示,hs-CRP异常对HP阳性的OR值为1.509,有统计学意义(P<0.05)。结论:2型糖尿病患者,HP感染可能通过增高hs-CRP水平,影响脂质代谢,触发一系列生物、生物化学级联反应,可使患者并发心血管病变的风险性增高。  相似文献   

19.
目的:探讨2型糖尿病(T2DM)患者幽门螺杆菌(HP)感染与超敏c反应蛋白(hs-CRP)、血脂水平的关系。方法:以2009年1月1日至2009年12月31日在我院体检的683例2型糖尿病患者为研究对象,根据HP感染情况分成HP阳性组(n=306)和HP阴性组(n=377),采用单因素和多因素Logistic回归分析方法,分析HP感染与hs-CRP、血脂水平的关系。结果:(1)HP阳性组的hs-CRP水平高于HP阴性组(1.14mg/L vs 0.96mg/L),差异有统计学意义(P〈0.05)。(2)HP阳性组的血脂异常率(59.8%vs 50.7%)和hs-CRP异常率(20.9%vs 14.3%)均高于HP阴性组,差异均有统计学意义(均P〈0.05)。(3)单因素Logistic回归分析显示,血脂异常和hs-CRP异常对HP阳性的OR值及分别为1.449和1.582,均有统计学意义(均P〈0.05),多因素Logistic回归分析显示,hs-CRP异常对HP阳性的OR值为1.509,有统计学意义(P〈0.05)。结论:2型糖尿病患者,HP感染可能通过增高hs-CRP水平,影响脂质代谢,触发一系列生物、生物化学级联反应,可使患者并发心血管病变的风险性增高。  相似文献   

20.
Early onset in bipolar disorder (BPD) has been associated with greater familial risk and unfavorable clinical outcomes. We pooled data from seven international centers to analyze the relationships of family history and symptomatic as well as functional measures of adult morbidity to onset age, or onset in childhood (age <12), adolescence (12-18), or adulthood (19-55 years). In 1,665 adult, DSM-IV BPD-I patients, onset was 5% in childhood, 28% in adolescence, and 53% at peak ages 15-25. Adolescent and adult onset did not differ by symptomatic morbidity (episodes/year, percentage of months ill, co-morbidity, hospitalization, suicide attempts) or family history. Indications of favorable adult functional outcomes (employment, living independently, marriage and children, and a composite measure including education) ranked, by onset: adult > adolescent > child. Onset in childhood versus adolescence had more episodes/year and more psychiatric co-morbidity. Family history was most prevalent with childhood onset, similar over onset ages 12-40 years, and fell sharply thereafter. Multivariate modeling sustained the impression that family history and poor functional, but not symptomatic, outcomes were associated with younger, especially childhood onset. Early onset was more related to poor functional outcomes than greater symptomatic morbidity, with least favorable outcomes and greater family history with childhood onset.  相似文献   

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