Blood mononuclear cells and platelets have abnormal fatty acid composition in homozygous sickle cell disease

Leukocyte adhesion to vascular endothelium contributes to vaso-occlusion and widespread organ damage in sickle cell disease (SCD). Previously, we found high expression of the adhesion molecules _M2 integrin and L-selectin in HbSS individuals with severe disease. Since membrane n-6 and n-3 polyunsaturated fatty acids modulate cell adhesion, inflammation, aggregation and vascular tone, we investigated the fatty acid composition of mononuclear cells (MNC) and platelets of HbSS patients in steady state (n=28) and racially matched, healthy HbAA controls with similar age and sex distribution living in the same environment (n=13). MNC phospholipids of the patients had lower levels of docosahexaenoic acid (DHA, p<0.01) and increased arachidonic acid (AA, p<0.005) relative to HbAA controls. Similarly, platelets from HbSS patients had less eicosapentaenoic acid (EPA, p<0.05) and more AA (p<0.05) in choline phosphoglycerides (CPG), with reduced DHA (p<0.05) in ethanolamine phosphoglycerides. Platelet CPG had lower DHA levels in SCD patients with complications compared to those without (p<0.05). Reduced cell content of EPA and DHA relative to AA favours the production of aggregatory and proinflammatory eicosanoids that activate leukocytes and platelets. This facilitates inflammation, leukocyte adhesion, platelet aggregation and vaso-occlusion in SCD.     

Asymmetric dimethylarginine increases mononuclear cell adhesiveness in hypercholesterolemic humans

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is elevated in hypercholesterolemia. This study was designed to determine the role of ADMA in the increased mononuclear cell adhesiveness observed in human hypercholesterolemia. In patient studies, plasma ADMA levels were determined by high-performance liquid chromatography. Functional mononuclear leukocyte adhesion assays were performed in parallel, and flow cytometry was used to characterize bound monocytes and T lymphocytes. Hypercholesterolemic patients were then placed on an oral L-arginine regimen of 14 or 21 g/d and studied over 12 weeks. In cell culture studies, bovine aortic endothelial cells were incubated with varied concentrations of ADMA. Monocytoid cells were cocultured with these bovine aortic endothelial cells, and their adhesiveness was assessed by use of a binding assay. Flow cytometry was used to quantify adhesion molecule expression. Plasma ADMA levels and adhesiveness of mononuclear cells (specifically, monocytes and T lymphocytes) were elevated in hypercholesterolemic patients. Adhesiveness was inversely correlated with the plasma L-arginine/ADMA ratio. Oral administration of L-arginine normalized plasma L-arginine/ADMA ratios and attenuated monocyte and T-lymphocyte adhesiveness. ADMA had no direct effect on the adhesiveness of mononuclear cells. However, monocytes became hyperadhesive when cocultured with ADMA-exposed endothelial cells. In human hypercholesterolemia, the plasma L-arginine/ADMA ratio is inversely correlated with mononuclear cell adhesiveness. Restoration of the L-arginine/ADMA ratio to control levels normalizes mononuclear cell adhesiveness. Our studies suggest that the elaboration of endothelium-derived nitric oxide affects the behavior of circulating T lymphocytes and monocytes.     

Low density lipoprotein metabolism in a family of familial hypercholesterolemic patients

A low-density lipoprotein turnover study was performed on six heterozygous familial hypercholesterolemic subjects and five control subjects. The diagnosis of the condition was clear-cut on biochemical, clinical, and genetic grounds. Kinetic analysis of the plasma decay curves gave the following mean values: (1) The plasma concentration of low density lipoprotein apoprotein (apoLDL) in the affected subjects was 247 mg/dl, a 2.5-fold increase over control values (98 mg/dl). (2) The calculated fractional catabolic rate of the intravascular apoLDL pool in the dyslipoproteinemics was reduced with respect to control data (16.4%/day versus 31.2%/day), and the half-life of the apolipoprotein was correspondingly increased (6.07 days versus 3.63 days). (3) The absolute catabolic rate of the apoLDL was 15.6 mg/kg/day in contrast to the lower value of 11.6 mg/kg/day in the control group. (4) A strong negative correlation was observed between the plasma apoLDL concentration and the fractional catabolic rate (r = 0.96).We conclude from our data that increased apoLDL synthesis coupled with a defective or saturated catabolic mechanism is implicated in the pathogenesis of familial hypercholesterolemia.     

Aminopeptidase activity in populations of human blood mononuclear cells

The aminopeptidase N (AP N, EC 3.4.11.2) is an ectoenzyme of the plasma membrane, playing presumably an important role in the regulation of immunological processes. The specific activities of Ala-pNA and Leu-pNA cleavage (per cell) are distributed in monocytes T- and non-T-lymphocytes in a proportion of 1:0.2:0.25 and 1:0.17:0.18, respectively. The capacities of Ala-pNA and Leu-pNA hydrolysis in the total fraction T- and non-T-cells are distributed as 1:0.8 and 1:0.7, respectively. The main part of Ala-pNA cleavage was shown to be caused by AP N on the basis of the KM-value (0.5 mmol/l), the activation by CO2+ ions and the pH optimum (7.0-7.5). The Leu-pNA cleavage is dependent on CO2+ and DTT and distinct from the classical cytosolic leucyl aminopeptidase.     

Inhibition of cholesterol biosynthesis in freshly isolated blood mononuclear cells from normolipidemic subjects and hypercholesterolemic patients treated with bezafibrate

Bezafibrate was given for 15 days at a dose of 200 mg t.i.d. to 4 normolipidemic subjects, to 5 patients with putative heterozygous familial hypercholesterolemia, and to 6 patients with primary hypercholesterolemia of the non-familial type. At the end of the treatment, the rate of incorporation of labelled acetate into non-saponifiable lipids in freshly isolated blood mononuclear cells decreased in all subjects. On the average, acetate incorporation decreased by 31% in cells from normolipidemic subjects, 41% in cells from familial, and 45% in cells from non-familial hypercholesterolemia patients. Results of the present study suggest that the lowering effect of bezafibrate on serum cholesterol is mainly due to the inhibition of cholesterol synthesis through the suppression of HMG-CoA reductase as was demonstrated in rat hepatocytes and in cultured human blood mononuclear cells.     

A family of homozygous familial hyperalphalipoproteinemia with complete deficiency of cholesteryl ester transfer activity

The propositus was a 43-year-old Japanese male with a plasma total cholesterol (chol) level of 252 mg/dl and a high density lipoprotein (HDL)-chol of 169 mg/dl. His brother also had a markedly higher HDL-chol level of 149 mg/dl. In addition, his mother, sister and all 3 children had higher HDL-chol levels of 75-91 mg/dl. These data suggest that the propositus and his brother were homozygous for familial hyperalphalipoproteinemia (FHALP), whereas his mother, sister and 3 children were heterozygous for FHALP. None had any clinical signs of atherosclerosis. The propositus and his brother (homozygous FHALP) also showed markedly higher levels of apo AI (greater than or equal to 190 mg/dl) and E (greater than 16 mg/dl). Ultracentrifugal analysis disclosed an increase of HDL2-chol in the propositus. Cholesteryl ester transfer activity (CETA) was completely absent in the propositus (0.0% transfer/5 microliters/18 hr) and his brother (0.3% transfer/5 microliters/18 hr). It is concluded that this case is a family of homozygous FHALP probably caused by complete deficiency of CETA.     

克罗恩病患者外周血单个核细胞中miR-27a的表达水平及意义

目的 探究克罗恩病(CD)患者外周血单个核细胞中miR-27a的表达水平及意义.方法 选择2016年8月至2017年3月在浙江衢化医院就诊的114例CD患者作为研究对象.采用Ficoll密度梯度离心法提取CD患者外周血中的单个核细胞.采用实时荧光定量PCR法检测外周血单个核细胞中miR-27a的表达水平,并分析其与患者...     

Procoagulant activity associated with mononuclear cells in active rheumatic fever

Acute rheumatic fever (ARF) is associated with disseminated inflammation and tissue lesions with heavy fibrin deposition, specially in heart valves and myocardium. The immune pathogenesis of ARF has been suspected, but not satisfactorily proven. An active cellular immune reaction generates cell activators (lymphokines) from T cells, which are able to induce a procoagulant activity (PCA) in mononuclear cells. We studied PCA in peripheral blood mononuclear cells isolated form ARF patients as well as normal controls. The PCA from ARF was 1.5 to 15 times higher than the PCA from controls. This activity was associated with the presence of C-reactive protein and other acute phase markers. The PCA from mononuclear cells in ARF may be one of the mechanisms responsible for fibrin deposition.     

Low burst-promoting activity (BPA) production by cord mononuclear cells is due to functional immaturity of monocytes

Cord blood mononuclear cells produced lower burst-promoting activity (BPA) than adult peripheral blood mononuclear cells when stimulated with phytohemagglutinin (PHA). In order to examine the cellular basis of the low production of BPA by PHA-stimulated cord blood mononuclear cells in the context of the functional immaturity of T cells or monocytes, we studied BPA production by T cells or monocytes from cord blood and adult peripheral blood. Cord T cells produced as much BPA as adult T cells. Monocytes themselves did not produce significant BPA at the concentration used in this experiment (1 x 10(5)/ml). BPA production by adult T cells was significantly enhanced by the presence of autologous monocytes. BPA production by cord T cells was also enhanced by the presence of adult monocytes but not by that of cord monocytes. Cord monocytes did not enhance BPA production by adult T cells either. These results indicate that cord monocytes are primarily responsible for the low BPA production by PHA-stimulated cord mononuclear cells.     

Telomerase activity and telomere length of peripheral blood mononuclear cells in SLE patients

We evaluated the clinical significance of the telomerase activity and telomere length of peripheral blood mononuclear cells (PBMC) in systemic lupus erythematosus (SLE). PBMC were isolated from 55 patients with SLE and the telomerase activity was measured by TRAP assay. The telomere length of PBMC was also measured in 30 of these subjects. As a control group, 45 healthy adults with no particular clinical history were studied. The results were compared with clinical data. In patients with active SLE, the telomerase activity of PBMC was significantly increased compared with the control group. In patients with inactive SLE, the PBMC telomerase activity was not different compared with the controls in their 20s, 30s and 40s, but it was significantly increased compared with the controls in their 50s. In SLE patients, the telomerase activity of PBMC was significantly correlated with modified SLEDAI. The telomere length of PBMC in younger SLE patients tended to be shorter than that in the controls, but no difference was observed in older patients. The correlation coefficient between the telomerase activity and telomere length of PBMC in SLE patients was not significant. Abnormalities in the telomerase activity and telomere length observed in SLE patients are considered to be important findings for evaluation of the pathology of SLE.     

Expression pattern of genes in peripheral blood mononuclear cells in diabetic nephropathy.

AIMS: Only one-third of Type 1 diabetes patients develop diabetic nephropathy, and a genetic predisposition is postulated. To obtain more insight into processes that lead to diabetic nephropathy, messenger RNA expression profiles of peripheral blood mononuclear cells from patients with and without diabetic nephropathy were compared. METHODS: We studied seven male patients with Type 1 diabetes and proteinuria and 12 male patients with Type 1 diabetes and normoalbuminuria after at least 20 years of diabetes duration. The expression of genes was examined using the microarray method with Human Genome U133A Arrays (Affymetrix, Santa Clara, CA, USA). We analysed the expression of all candidate genes suggested to be involved in the pathogenesis of diabetic nephropathy in previously published articles. Altogether, expression of 198 genes was analysed. RESULTS: We found that thrombospondin 1 (THBS1) and cyclooxygenase 1(COX1) genes were over-expressed in patients with diabetic nephropathy, and matrix metalloproteinase 9 (MMP9) and cyclooxygenase 2 (COX2) genes had lower expression in diabetic nephropathy. For other genes, we did not observe different expression between patients with and without diabetic nephropathy,or the expression was too low for analysis. CONCLUSIONS: The different gene expression pattern in peripheral blood mononuclear cells in patients with diabetic nephropathy might indicate an important pathway in the pathogenesis of this complication.     

急性髓系白血病骨髓单个核细胞CD11a的表达及临床意义

目的:探讨淋巴细胞功能相关抗原-1(LFA-1)的α链CD11a在急性髓系白血病(AML)的表达情况及临床意义。方法:采用免疫酶标ABC法检测25例初治AML患者和8例血液系统非恶性肿瘤患者为对照的骨髓单个核细胞CD11a的表达,并追踪观察AML患者的疗效。结果:CD11a在AML患者骨髓单个核细胞的表达率(37.02±13.30)%,明显低于对照组(87.13±5.38)%(P<0.05)。化疗后未缓解组AML患者发病时骨髓单个核细胞CD11a的表达率(47.09±10.55)较完全缓解组(29.11±9.36)%高(P<0.05)。结论:CD11a在AML患者骨髓单个核细胞表达异常,可能与白血病细胞逃脱机体免疫监控及从造血微环境释出有关。检测AML患者骨髓单个核细胞CD11a的表达水平对AML的预后判断有一定意义。     

Expression of functional estrogen receptor beta in locus coeruleus-derived Cath.a cells

Estrogen may have an important role in the brain beyond the development and regulation of reproductive function. Gender differences in the incidence of depression suggest that regulation of mood represents one such action. The locus coeruleus, a brain stem noradrenergic nucleus implicated in mood regulation, concentrates [(3)H]estradiol, but expression of the two estrogen receptor (ER) subtypes (ERalpha and ERbeta) varies across species. Further, the role of each subtype in estrogen action on noradrenergic neurons is unknown. We examined the expression of ERs in the Cath.a (central-adrenergic-tyrosine-hydroxylase-expressing) cell line derived from mouse brain stem and found that they express ERbeta protein but not ERalpha protein. Transient transfection assays using an estrogen-responsive reporter gene indicate that ERbeta is functional. The pure estrogen antagonist ICI 182,780 completely abolished estrogen's effects. Selective ER modulator results suggest that ER in Cath.a cells behaves in a manner consistent with ERbeta pharmacology. R,R-Tetrahydrochrysene, an ERalpha agonist, had no effect on luciferase-driven activity in Cath.a cells. This study provides the first report of a cell line that spontaneously expresses functional ERbeta protein. Cath.a cells may prove to be a useful tool in elucidating basic pharmacologic properties of ERbeta. It may also help reveal the molecular mechanisms involved in mood regulation by estrogen.