scholarly journals Molecular basis of spectrin deficiency in hereditary pyropoikilocytosis

Blood ◽  
1993 ◽  
Vol 82 (5) ◽  
pp. 1652-1660 ◽  
Author(s):  
M Hanspal ◽  
JS Hanspal ◽  
KE Sahr ◽  
E Fibach ◽  
J Nachman ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Mononuclear Cells ◽  
Mrna Levels ◽  
Two Phase ◽  
Peripheral Blood Mononuclear ◽  
Asymptomatic Carriers ◽  
Direct Demonstration ◽  
Liquid Culture System ◽  
Alpha Spectrin ◽  
Self Association

Abstract Hereditary pyropoikilocytosis (HPP) is a recessively inherited hemolytic anemia characterized by severe poikilocytosis and red blood cell fragmentation. HPP red blood cells are partially deficient in spectrin and contain a mutant alpha or beta-spectrin that is defective in terms of spectrin self-association. Although the nature of the latter defect has been studied in considerable detail and many mutations of alpha-spectrin and beta spectrin have been identified, the molecular basis of spectrin deficiency is unknown. Here we report two mechanisms underlying spectrin deficiency in HPP. The first mechanism involves a thalassemia-like defect characterized by a reduced synthesis of alpha-spectrin as shown by studies involving synthesis of spectrin in two unrelated HPP probands and their parents: One parent carries the elliptocytogenic spectrin mutation, whereas the other parent is fully asymptomatic. Peripheral blood mononuclear cells as a source of erythroid burst-forming unit (BFUe) were cultured in a two-phase liquid culture system that gives rise to terminally differentiated erythroblasts. Pulse-labeling studies of an equal number of erythroblasts or morphologically identical maturity showed that the synthesis of alpha-spectrin as well as the mRNA levels as measured by the competitive polymerase chain reaction (PCR) method are markedly reduced in the presumed asymptomatic carriers and the HPP probands. In contrast, the synthesis and mRNA levels of beta-spectrin were normal. These results constitute a direct demonstration of an alpha-spectrin synthetic defect in a subset of asymptomatic carriers of HPP and HPP probands. The second mechanism underlying spectrin deficiency involves increased degradation of mutant spectrin before its assembly on the membrane. This is evidenced by pulse labeling studies of erythroblasts from a patient with HPP associated with a homozygous state for spectrin alpha I/46 mutation (leu-pro mutation at AA 207 of alpha-spectrin). These studies showed that although spectrin is synthesized in the cytosol in normal amounts, the rate of turnover of alpha-spectrin is faster resulting in about 40% to 50% reduced assembly of alpha-spectrin and beta-spectrin on the membrane. Thus, spectrin deficiency in this case is at least in part caused by increased susceptibility of the mutant spectrin to degradation before its assembly on the membrane. We conclude that at least two separate mechanisms underlie the molecular basis of spectrin deficiency in HPP.

scholarly journals Molecular basis of spectrin deficiency in hereditary pyropoikilocytosis

Blood ◽  
1993 ◽  
Vol 82 (5) ◽  
pp. 1652-1660
Author(s):  
M Hanspal ◽  
JS Hanspal ◽  
KE Sahr ◽  
E Fibach ◽  
J Nachman ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Mononuclear Cells ◽  
Mrna Levels ◽  
Two Phase ◽  
Peripheral Blood Mononuclear ◽  
Asymptomatic Carriers ◽  
Direct Demonstration ◽  
Liquid Culture System ◽  
Alpha Spectrin ◽  
Self Association

Hereditary pyropoikilocytosis (HPP) is a recessively inherited hemolytic anemia characterized by severe poikilocytosis and red blood cell fragmentation. HPP red blood cells are partially deficient in spectrin and contain a mutant alpha or beta-spectrin that is defective in terms of spectrin self-association. Although the nature of the latter defect has been studied in considerable detail and many mutations of alpha-spectrin and beta spectrin have been identified, the molecular basis of spectrin deficiency is unknown. Here we report two mechanisms underlying spectrin deficiency in HPP. The first mechanism involves a thalassemia-like defect characterized by a reduced synthesis of alpha-spectrin as shown by studies involving synthesis of spectrin in two unrelated HPP probands and their parents: One parent carries the elliptocytogenic spectrin mutation, whereas the other parent is fully asymptomatic. Peripheral blood mononuclear cells as a source of erythroid burst-forming unit (BFUe) were cultured in a two-phase liquid culture system that gives rise to terminally differentiated erythroblasts. Pulse-labeling studies of an equal number of erythroblasts or morphologically identical maturity showed that the synthesis of alpha-spectrin as well as the mRNA levels as measured by the competitive polymerase chain reaction (PCR) method are markedly reduced in the presumed asymptomatic carriers and the HPP probands. In contrast, the synthesis and mRNA levels of beta-spectrin were normal. These results constitute a direct demonstration of an alpha-spectrin synthetic defect in a subset of asymptomatic carriers of HPP and HPP probands. The second mechanism underlying spectrin deficiency involves increased degradation of mutant spectrin before its assembly on the membrane. This is evidenced by pulse labeling studies of erythroblasts from a patient with HPP associated with a homozygous state for spectrin alpha I/46 mutation (leu-pro mutation at AA 207 of alpha-spectrin). These studies showed that although spectrin is synthesized in the cytosol in normal amounts, the rate of turnover of alpha-spectrin is faster resulting in about 40% to 50% reduced assembly of alpha-spectrin and beta-spectrin on the membrane. Thus, spectrin deficiency in this case is at least in part caused by increased susceptibility of the mutant spectrin to degradation before its assembly on the membrane. We conclude that at least two separate mechanisms underlie the molecular basis of spectrin deficiency in HPP.

scholarly journals Blood functional assay for rapid clinical interpretation of germline TP53 variants

2020 ◽  
pp. jmedgenet-2020-107059 ◽  
Author(s):  
Sabine Raad ◽  
Marion Rolain ◽  
Sophie Coutant ◽  
Céline Derambure ◽  
Raphael Lanos ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Transcriptional Response ◽  
Functional Assay ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Patients With Cancer ◽  
Pathogenic Variants ◽  
Functional Variants ◽  
Multiplex Ligation Probe Amplification ◽  
P53 Mrna

BackgroundThe interpretation of germline TP53 variants is critical to ensure appropriate medical management of patients with cancer and follow-up of variant carriers. This interpretation remains complex and is becoming a growing challenge considering the exponential increase in TP53 tests. We developed a functional assay directly performed on patients’ blood.MethodsPeripheral blood mononuclear cells were cultured, activated, exposed to doxorubicin and the p53-mediated transcriptional response was quantified using reverse transcription–multiplex ligation probe amplification and RT-QMPSF assays, including 10 p53 targets selected from transcriptome analysis, and two amplicons to measure p53 mRNA levels. We applied this blood functional assay to 77 patients addressed for TP53 analysis.ResultsIn 51 wild-type TP53 individuals, the mean p53 functionality score was 12.7 (range 7.5–22.8). Among eight individuals harbouring likely pathogenic or pathogenic variants, the scores were reduced (mean 4.8, range 3.1–7.1), and p53 mRNA levels were reduced in patients harbouring truncating variants. We tested 14 rare unclassified variants (p.(Pro72His), p.(Gly105Asp), p.(Arg110His), p.(Phe134Leu), p.(Arg158Cys), p.(Pro191Arg), p.(Pro278Arg), p.(Arg283Cys), p.(Leu348Ser), p.(Asp352Tyr), p.(Gly108_Phe109delinsVal), p.(Asn131del), p.(Leu265del), c.-117G>T) and 12 yielded functionally abnormal scores. Remarkably, the assay revealed that the c.*1175A>C polymorphic variant within TP53 poly-adenylation site can impact p53 function with the same magnitude as a null variant, when present on both alleles, and may act as a modifying factor in pathogenic variant carriers.ConclusionThis blood p53 assay should therefore be a useful tool for the rapid clinical classification of germline TP53 variants and detection of non-coding functional variants.

scholarly journals Decreased levels of miR-28-5p and miR-361-3p and increased levels of insulin-like growth factor 1 mRNA in mononuclear cells from patients with hereditary hemorrhagic telangiectasia

2019 ◽  
Vol 97 (6) ◽  
pp. 562-569 ◽  
Author(s):  
Anthony Cannavicci ◽  
Qiuwang Zhang ◽  
Si-Cheng Dai ◽  
Marie E. Faughnan ◽  
Michael J.B. Kutryk
Keyword(s):  
Growth Factor ◽  
Peripheral Blood ◽  
Hereditary Hemorrhagic Telangiectasia ◽  
Mononuclear Cells ◽  
Quantitative Polymerase Chain Reaction ◽  
Clinical Manifestations ◽  
Mrna Levels ◽  
Insulin Like Growth Factor ◽  
Peripheral Blood Mononuclear ◽  
Micro Rnas

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disorder inherited in an autosomal dominant manner. Patients with HHT can develop vascular dysplasias called telangiectasias and arteriovenous malformations (AVMs). Our objective was to profile and characterize micro-RNAs (miRNAs), short noncoding RNAs that regulate gene expression posttranscriptionally, in HHT patient-derived peripheral blood mononuclear cells (PBMCs). PBMCs, comprised mostly of lymphocytes and monocytes, have been reported to be dysfunctional in HHT. A total of 40 clinically confirmed HHT patients and 22 controls were enrolled in this study. PBMCs were isolated from 16 mL of peripheral blood and purified for total RNA. MiRNA expression profiling was conducted with a human miRNA array analysis. Select dysregulated miRNAs and miRNA targets were validated with reverse transcription–quantitative polymerase chain reaction. Of the 377 miRNAs screened, 41 dysregulated miRNAs were identified. Both miR-28-5p and miR-361-3p, known to target insulin-like growth factor 1 (IGF1), a potent angiogenic growth factor, were found to be significantly downregulated in HHT patients. Consequently, IGF1 mRNA levels were found to be significantly elevated. Our research successfully identified miRNA dysregulation and elevated IGF1 mRNA levels in PBMCs from HHT patients. This novel discovery represents a potential pathogenic mechanism that could be targeted to alleviate clinical manifestations of HHT.

Reduced Expression of Annexin A2 is Associated with Impaired Cell Surface Fibrinolysis and Venous Thromboembolism

Blood ◽  
2021 ◽  
Author(s):  
Hannah Fassel ◽  
Huigen Chen ◽  
Mary Ruisi ◽  
Neha Kumar ◽  
Maria T DeSancho ◽  
...  
Keyword(s):  
Risk Factor ◽  
Venous Thromboembolism ◽  
Cell Surface ◽  
Mononuclear Cells ◽  
Annexin A2 ◽  
Clot Lysis ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Intravascular Thrombosis

Reduced plasma fibrinolysis has been identified as a potential risk factor for venous thromboembolism (VTE), but the role of cell surface fibrinolysis in VTE is unknown. The annexin A2/S100A10 complex serves as a co-receptor for plasminogen and tissue plasminogen activator (tPA), augmenting plasmin generation by 60-fold on the endothelial cell surface. Several studies in both mice and humans support the concept that A2 regulates fibrin homeostasis and intravascular thrombosis in vivo. Here, we examined A2 protein expression and function in 115 adult subjects with venous thromboembolism (VTE) and 87 healthy controls. Using peripheral blood mononuclear cells (PBMCs) as a surrogate for endothelial cells, we found a 41% mean decrease in cell surface tPA-dependent fibrinolytic activity in subjects who had a positive personal and family history of VTE, but tested negative for known inherited thrombophilias. A2 protein was reduced on average by 70%, and mRNA levels by 30%, but neither decrease correlated with anticoagulant therapy. [Sentence omitted] Neither cell A2 protein nor cell surface plasmin generation correlated with plasma-based clot lysis times, suggesting that the plasma and cell surface fibrinolytic systems operate independently of one another. These data suggest that reduced expression of annexin A2 protein is associated with cell surface hypofibrinolysis and may represent a novel risk factor for inherited thrombophilia.

scholarly journals Gene Expression of Adhesion Molecules in Endothelial Cells from Patients with Peripheral Arterial Disease Is Reduced after Surgical Revascularization and Pharmacological Treatment

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Franca Marino ◽  
Luigina Guasti ◽  
Matteo Tozzi ◽  
Laura Schembri ◽  
Luana Castiglioni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Mrna Expression ◽  
Adhesion Molecules ◽  
Mononuclear Cells ◽  
Venous Blood ◽  
Statin Treatment ◽  
Early Event ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear

Atherosclerosis is an inflammatory disease characterized by immunological activity, in which endothelial dysfunction represents an early event leading to subsequent inflammatory vascular damage. We investigated gene expression of the adhesion molecules (AMs) ICAM-1, VCAM-1, andβ1-integrin in endothelial cells (ECs) isolated from venous blood (circulating EC, cEC) and purified from femoral plaques (pEC) obtained from 9 patients with peripheral artery disease (PAD) submitted to femoral artery thrombendarterectomy (FEA). In addition, in peripheral blood mononuclear cells (PBMCs) of the same subjects, we investigated gene expression of IFN-γ, IL-4, TGF-β, and IL-10. Patients were longitudinally evaluated 1 month before surgery, when statin treatment was established, at the time of surgery, and after 2 and 5 months. All AM mRNA levels, measured by means of real-time PCR, in cEC diminished during the study, up to 41–50% of initial levels at followup. AM mRNA expression was significantly higher in pEC than in cEC. During the study, in PBMCs, TGF-βand IL-10 mRNA levels remained unchanged while IFN-γand IL-4 levels increased; however, the ratio IFN-γ/IL-4 showed no significant modification. In PAD patients, FEA and statin treatment induce a profound reduction of AM expression in cEC and affect cytokine mRNA expression in PBMCs.

Data on cytokine mRNA expression in CSF and peripheral blood mononuclear cells from MS patients as detected by PCR

1998 ◽  
Vol 4 (3) ◽  
pp. 143-146 ◽  
Author(s):  
Philippe Monteyne ◽  
Christian JM Sindic
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Inflammatory Diseases ◽  
Clinical Activity ◽  
Immune Reactivity ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Csf Cells ◽  
Blood Mononuclear Cells

Reverse transcription polymerase chain reaction (RT-PCR) was used to amplify the mRNA coding for different cytokines in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) cells from 18 multiple sclerosis (MS) patients as compared with 21 other neurological patients. mRNA levels were quantitated by radioactive hybridization of the PCR products. Expression of tumor necrosis factor (TNF)-a, interferon (IFN)-g, and interleukin (IL)-10 mRNA was elevated in CSF cells of MS patients. In many MS patients, both proinflammatory and immunoregulatory cytokine messages were detected in the CSF compartment. Such immune reactivity of CSF cells, as opposed to PBMC, was not associated with higher clinical activity of the disease. Expression of the B7.1 accessory molecule mRNA was similarly investigated. In the CSF, it was detected only in some clinically active MS cases and in other inflammatory diseases.

scholarly journals Molecular basis of spectrin and ankyrin deficiencies in severe hereditary spherocytosis: evidence implicating a primary defect of ankyrin

Blood ◽  
1991 ◽  
Vol 77 (1) ◽  
pp. 165-173 ◽  
Author(s):  
M Hanspal ◽  
SH Yoon ◽  
H Yu ◽  
JS Hanspal ◽  
S Lambert ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Hereditary Spherocytosis ◽  
Normal Values ◽  
Binding Protein ◽  
Mrna Levels ◽  
Slot Blot ◽  
Primary Defect ◽  
Control Range ◽  
Severe Deficiency ◽  
Alpha Spectrin

Abstract While varying degrees of spectrin deficiency have been found in the majority of patients with hereditary spherocytosis (HS), a combined severe deficiency of both spectrin and the spectrin-binding protein, ankyrin, has been reported only in two patients with severe HS. To elucidate the molecular basis of these protein deficiencies, we have studied the synthesis, assembly, and the mRNA levels of spectrin and ankyrin in peripheral blood reticulocytes in one of the previously reported probands. Pulse-labeling studies showed that in HS reticulocytes, the synthesis of alpha-spectrin was comparable with control reticulocytes while that of beta-spectrin was increased about fourfold, presumably reflecting increased erythropoietic drive. On the HS reticulocyte membrane, the amount of newly assembled spectrin was reduced to about half of the control values, presumably reflecting a decrease in the synthesis of the spectrin binding protein, ankyrin: the ankyrin synthesis was nearly absent in the cytosol and the amounts of membrane-associated ankyrin were reduced to about half of the normal values. The changes in the amounts of spectrin and ankyrin mRNAs quantitated by slot blot and Northern blot analyses were comparable with changes in the synthesis of these proteins: The alpha spectrin mRNA was within a control range and the beta-spectrin mRNA was slightly increased, while the amounts of ankyrin mRNA were reduced to about 50% of control values. We conclude that the primary defect underlying the combined spectrin and ankyrin deficiency is a deficiency of ankyrin mRNA leading to a reduced synthesis of ankyrin which, in turn, underlies the decreased assembly of spectrin on the membrane.

Non-inertial lift induced migration for label-free sorting of cells in a co-flowing aqueous two-phase system

The Analyst ◽  
2019 ◽  
Vol 144 (8) ◽  
pp. 2574-2583 ◽  
Author(s):  
S. Hazra ◽  
K. S. Jayaprakash ◽  
K. Pandian ◽  
A. Raj ◽  
S. K. Mitra ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Mononuclear Cells ◽  
Phase System ◽  
Label Free ◽  
Two Phase ◽  
Peripheral Blood Mononuclear ◽  
Aqueous Two Phase System ◽  
System P ◽  
Blood Mononuclear Cells ◽  
Microfluidic Technique

We present a novel label-free passive microfluidic technique for isolation of cancer cells (EpCAM+ and CD45−) from peripheral blood mononuclear cells (PBMCs) (CD45+ and EpCAM−) in aqueous two-phase system (ATPS).

Systemic upregulation of CD40 and CD40 ligand mRNA expression in multiple sclerosis

2000 ◽  
Vol 6 (2) ◽  
pp. 61-65 ◽  
Author(s):  
Wen-Xin Huang ◽  
Ping Huang ◽  
Jan Hillert
Keyword(s):  
Multiple Sclerosis ◽  
Mononuclear Cells ◽  
Cd40 Ligand ◽  
Autoimmune Response ◽  
Mrna Levels ◽  
Healthy Controls ◽  
Peripheral Blood Mononuclear ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Organ Specific

It is increasingly clear that the CD40 and CD40 ligand (CD40L) receptor-ligand pair mediates a crucial activation signal in both cell-mediated and humoral immune responses. Here, we detected mRNA levels of CD40 and CD40L in non-stimulated peripheral blood mononuclear cells in 46 patients with multiple sclerosis (MS) and 46 healthy controls by a competitive RT-PCR procedure allowing quantification without previous culture or antigenic stimulation. The levels of CD40 and CD40L mRNA were markedly increased in MS patients (P <0.0001) compared with healthy controls. There was no difference between clinical MS subgroups or stage of disease. Our findings indicate that, although MS is an organ specific disorder an increased signaling via the CD40 and CD40L pathway may be present at the systemic level. The nature of this upregulation, whether primary or secondary to the organ-specific autoimmune response, is yet to be determined. Since interference with CD40/CD40L is an effective way to interfere with autoimmune model diseases such as experimental autoimmune encephalomyelitis, it may be relevant to investigate further the role of these molecules in the pathogenesis of MS.

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