Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q00604 (X-linked)
 16,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have recently reported that the RD114-pseudotyped MFGS-gp91phox vector achieves unprecedented levels of correction of the NADPH-oxidase gp91phox (approved gene symbol CYBB) defect in CD34(+) cells from patients with X-linked chronic granulomatous disease in the NOD/SCID mouse model. Considering clinical use of this vector, we transplanted autologous mobilized peripheral blood CD34(+) progenitor cells, transduced with the RD114-MFGS-gp91phox vector, into two healthy rhesus macaques following nonmyeloablative conditioning. The moderately high levels of in vivo marking seen in the first months following transduction decreased and stabilized at about 8 months posttransplant. Marking for both healthy animals after 15 months was 0.3 to 1.3 vector copies per 100 cells in lymphocytes, neutrophils, and monocytes. Vector insertion analyses performed by linear amplification-mediated PCR and sequencing identified 32 and 45 separate insertion sites in the animals. Identical insertion sites were found in myeloid cells and lymphocytes, demonstrating the successful transduction of lymphomyeloid progenitors. Some inserts landed in the vicinity of genes controlling cell cycle and proliferation. Statistical analyses of insertion sites 1 year posttransplant suggest a high diversity of insertion sites despite low marking.
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PMID:Polyclonal long-term MFGS-gp91phox marking in rhesus macaques after nonmyeloablative transplantation with transduced autologous peripheral blood progenitor cells. 1660 Jun 88

In this study, we have identified an altered B cell compartment in patients with chronic granulomatous disease (CGD), a disorder of phagocyte function, characterized by pyogenic infections and granuloma formation caused by defects in NADPH activity. This is characterized by an expansion of CD5-expressing B cells, and profound reduction in B cells expressing the memory B cell marker, CD27. Both findings were independent of the age, genotype, and clinical status of the patients, and were not accompanied by altered CD5 and CD27 expression on T cells. Focusing on CD27-positive B cells, considered to be memory cells based on somatically mutated Ig genes, we found that the reduction was not caused by CD27 shedding or abnormal retention of CD27 protein inside the cell. Rather, it was determined that CD27-negative B cells were, appropriately, CD27 mRNA negative, consistent with a naive phenotype, whereas CD27-positive B cells contained abundant CD27 mRNA and displayed somatic mutations, consistent with a memory B cell phenotype. Thus, it appears that CGD is associated with a significant reduction in the peripheral blood memory B cell compartment, but that the basic processes of somatic mutation and expression of CD27 are intact. X-linked carriers of CGD revealed a significant correlation between the percentage of CD27-positive B cells and the percentage of neutrophils with normal NADPH activity, reflective of the degree of X chromosome lyonization. These results suggest a role for NADPH in the process of memory B cell formation, inviting further exploration of secondary Ab responses in CGD patients.
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PMID:Patients with chronic granulomatous disease have a reduced peripheral blood memory B cell compartment. 1670 72

Amyotrophic lateral sclerosis (ALS), one of the most common adult-onset neurodegenerative diseases, has no known cure. Enhanced redox stress and inflammation have been associated with the pathoprogression of ALS through a poorly defined mechanism. Here we determined that dysregulated redox stress in ALS mice caused by NADPH oxidases Nox1 and Nox2 significantly influenced the progression of motor neuron disease caused by mutant SOD1(G93A) expression. Deletion of either Nox gene significantly slowed disease progression and improved survival. However, 50% survival rates were enhanced significantly more by Nox2 deletion than by Nox1 deletion. Interestingly, female ALS mice containing only 1 active X-linked Nox1 or Nox2 gene also had significantly delayed disease onset, but showed normal disease progression rates. Nox activity in spinal cords from Nox2 heterozygous female ALS mice was approximately 50% that of WT female ALS mice, suggesting that random X-inactivation was not influenced by Nox2 gene deletion. Hence, chimerism with respect to Nox-expressing cells in the spinal cord significantly delayed onset of motor neuron disease in ALS. These studies define what we believe to be new modifier gene targets for treatment of ALS.
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PMID:Redox modifier genes in amyotrophic lateral sclerosis in mice. 1785 44

Chronic granulomatous disease (CGD) is a hereditary illness generally occurring in childhood, in the form of recurrent severe infections. The main pathogens are staphylococci and aspergilli. It results from a failure of professional phagocytes, and particularly neutrophils, to produce superoxide ions O2- and their derivatives, which protect cells from bacterial, invasion through an oxidative and toxic defence mechanism. At an infection site. contact between the neutrophils and microorganisms or an inflammatory mediator triggers a respiratory burst, which results in the activation of the NADPH oxidase enzyme complex. NADPH depletes surrounding oxygen to yield O2-. In its active form. NADPH oxidase is an assembly of two components, namely the membrane cytochrome b558 (consisting o two subunits, gp91-phox and p22-phox) and soluble protein factors present in the resting neutrophil cytoplasm. Transfer of these cytosolic factors and their anchorage to cytochrome b558 determines the activity of NADPH oxidase. The respiratory burst lasts no more than a few minutes, but the precise mechanisms underlying its termination are not well known. In chronic granulomatous disease, neutrophils have lost their bactericidal capacity The most frequent form is hereditary and X-linked; in this case, the affected gene is CYBB, which encodes gp91-phox, the catalytic subunit of cytochrome b558. In autosomal and recessive forms of CGD the mutations affect the genes encoding p22-phox, p67-phox or p47-phox. We have unraveled the assembly mechanisms of the NADPH oxidase complex and have demonstrated that the cytosolic factor p67-phox is the determining element: it triggers both the assembly and the activation of NI4DPH oxidase. Binding of p67-phox to cytochrome b558 induces a gradual conformational change of cytochrome b558, which then becomes capable of transferring electrons produced in the cytoplasm from NADPH to oxygen, reducing the latter to O2-. The isolation of NADPH oxidase in its active and assembled form has allowed us to identify the activation partners of the oxidase complex. We also demonstrated that calcium-binding myeloid-related proteins (MRP). that are abundant in neutrophil cytoplasm, play a fundamental role in this activation. CGD patient management is essentially based on long-term high-dose prophylactic antibiotic administration. Gene therapy is promising but some distance away from practical application. We are currently investigating a new therapeutic concept that consists of transferring cytochrome b558 protein directly into deficient cells (initially the PLB 985 X cell line), encapsulated in proteoliposomes, which are hydrophobic.
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PMID:[Molecular aspects of chronic granulomatous disease. "the NADPH oxidase complex"]. 1796 55

Mutations in any of four known NADPH-oxidase components lead to CGD. X-linked CGD (X-CGD) is caused by defects in CYBB, the gene that encodes gp91-phox. Autosomal recessive (AR) CGD is caused by defects in the genes for p47 phox, p22-phox or p67-phox. The aim of this study was to screen the molecular defect in the fetus of an X-CGD carrier mother and postnatal confirmation of the results. In a family whose first-born child died from X-CGD, fetal DNA was obtained from an ongoing pregnancy by chorionic villus sampling (CVS). Direct sequencing was used to detect the previously identified CYBB gene mutation. The NADPH oxidase activity in the neutrophils from the carrier mother and from the newborn was analyzed by the DHR assay. Our studies predicted that the fetus in question was not affected by chronic granulomatous disease, which was demonstrated to be correct at birth. For prenatal screening in a pregnant X-CGD carrier, direct sequencing is a good method for detecting the mutation in the fetal DNA. Postnatal confirmation of results with the DHR assay is more practical than mutation screening to show whether the newborn have normal NADPH oxidase activity or does not.
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PMID:Prenatal diagnosis of chronic granulomatous disease in a male fetus. 1927 61

X-linked chronic granulomatous disease (X-CGD) is an inherited immunodeficiency with absent phagocyte NADPH-oxidase activity caused by defects in the gene-encoding gp91(phox). Here, we evaluated strategies for less intensive conditioning for gene therapy of genetic blood disorders without selective advantage for gene correction, such as might be used in a human X-CGD protocol. We compared submyeloablative with ablative irradiation as conditioning in murine X-CGD, examining engraftment, oxidase activity and vector integration in mice transplanted with marrow transduced with a gamma-retroviral vector for gp91(phox) expression. The frequency of oxidase-positive neutrophils in the donor population was unexpectedly higher in many 300 cGy-conditioned mice compared with lethally irradiated recipients, as was the fraction of vector-marked donor secondary CFU-S12. Vector integration sites in marrow, spleen and secondary CFU-S12 DNA from primary recipients were enriched for cancer-associated genes, including Evi1, and integrations in or near cancer-associated genes were more frequent in marrow and secondary CFU-S12 from 300 cGy-conditioned mice compared with fully ablated mice. These findings support the concept that vector integration can confer a selection bias, and suggest that the intensity of the conditioning regimen may further influence the effects of vector integration on clonal selection in post-transplant engraftment and hematopoiesis.
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PMID:Retroviral vector integration in post-transplant hematopoiesis in mice conditioned with either submyeloablative or ablative irradiation. 1965 70

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a typical X-linked enzymopathy causing severe haemolytic anaemia in males, and mild to moderate anaemia in homozygous females. Haemolysis due to G6PD deficiency in patients with type 1 diabetes mellitus (T1DM) has been principally reported in males, but is uncommon. During the last 10 years 2 girls with an unknown incomplete G-6-PD deficiency showed haemolysis during the treatment of DKA at the onset of T1DM. We speculate that the patients here described showed haemolytic anaemia as a phenotypic expression of the lyonization process and/or an uncommon penetrance of the defective gene. Haemolysis occurred when blood glucose levels were returning to normal values. In normal red blood cells, G6PD provides a source of reducing power for maintaining sulphydryl groups (SH) and facilitating the detoxification of free radicals and peroxides. During insulin i.v. infusion the copious glucose available due to the hyperglycaemia progressively decreased and affected the old red blood cells to generate nicotinamide adenine dinucleotide (NADPH), a crucial source for energy-dependent functions. This NADPH loss could have enhanced the rate of all factors such as methaemoglobin generation, Heinz body formation, and lipid peroxidation, which occur in G6PD deficient cells in response to both endogenous and exogenous oxidants. The direct consequence of this phenomenon is an increased erytrocyte oxidant sensitivity and a loss of sulphydryl group availability causing premature red blood cell destruction.
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PMID:Haemolysis during diabetic ketoacidosis treatment in two girls with incomplete glucose-6-phosphate dehydrogenase deficiency. 1970 24

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common form of red blood cell enzymopathy. The disorder has reached polymorphic frequencies in different parts of the world due to the relative protection conferred against malaria. G6PD is a housekeeping X-linked gene encoding the first enzyme of the pentose phosphate pathway, an NADPH-producing dehydrogenase. Because erythrocytes do not generate NADPH in any other way than pentose phosphate pathway, they are more susceptible than any other cells to oxidative damages. G6PD deficiency is a prime example of a hemolytic anemia due to an interaction between an intracorpuscular cause and an extracorpuscular cause, because in the majority of cases an exogenous agent triggers hemolysis. Hemolysis, in fact, can be caused by exposure to oxidant agents. Although studies performed on epidemiology, genetics and molecular biology have broaden the information on G6pd deficiency, there are still no reliable and validated methods to test drug hemolytic potential in G6PD deficient patients. The review gives an overview of current knowledge on G6pd deficiency and on the methods that have been developed so far in order to identify drugs causing acute hemolytic anemia in G6pd deficiency. Moreover, we discuss the new potential preclinical strategies to assess, in vitro and in vivo, drug hemolytic risks.
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PMID:Discussion on pharmacogenetic interaction in G6PD deficiency and methods to identify potential hemolytic drugs. 2035 Feb 85

Murine models of human genetic disorders provide a valuable tool for investigating the scope for application of induced pluripotent stem cells (iPSC). Here we present a proof-of-concept study to demonstrate generation of iPSC from a mouse model of X-linked chronic granulomatous disease (X-CGD), and their successful differentiation into haematopoietic progenitors of the myeloid lineage. We further demonstrate that additive gene transfer using lentiviral vectors encoding gp91(phox) is capable of restoring NADPH-oxidase activity in mature neutrophils derived from X-CGD iPSC. In the longer term, correction of iPSC from human patients with CGD has therapeutic potential not only through generation of transplantable haematopoietic stem cells, but also through production of large numbers of autologous functional neutrophils.
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PMID:Generation of functional neutrophils from a mouse model of X-linked chronic granulomatous disorder using induced pluripotent stem cells. 2140 14

Chronic granulomatous disease (CGD) is a primary immunodeficiency, it has a defect in phagocytosis and its estimated incidence is 1 in 250,000 live births. Recurrent infections and granulomas are the most common clinical manifestations. CGD is caused by a functional defect in one of the subunits of the NADPH oxidase, the patients have mutations in NADPH genes. There are two patterns of transmission described in CGD, X-linked and autosomal recessive. The diagnosis of CGD is made by direct measurement of superoxide production, ferricytochrome c reduction, chemiluminescence, reduction of nitroblue tetrazolium or 1, 2, 3 dihydrorhodamine oxidation. After the diagnosis of CGD is important to identify the pattern of transmission in each case in order to provide genetic counseling to the patient's family, as well as inform Xlinked CGD carriers that have a major risk to develop autoimmune diseases. The 1, 2, 3, DHR help to identify the pattern of transmission and carriers of CGD Xlinked, it is considered as a screening method because of its easiness, sensitive and inexpensive cost.
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PMID:[Chronic granulomatous disease diagnosis: Patients and carriers]. 2196 72


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