We have investigated the regulatory role of DNA methylation in the expression of the human histo-blood group ABO genes. The ABO gene promoter region contains a CpG island whose methylation status correlates well with gene expression in the cell lines tested. The CpG island was found hypomethylated in some cell lines that expressed ABO genes, whereas the other cell lines that did not express ABO genes were hypermethylated. The ABO blood group system discovered by Karl Landsteiner (1) at the beginning of this century is of great importance in blood transfusions and organ transplantations. Two carbohydrate antigens, A-and B-antigens, and their antibodies constitute this system. The A and B functional alleles at the ABO genetic locus encode glycosyltransferases ␣133GalNAc transferase (designated A-transferase) and ␣133Gal transferase (designated B-transferase), respectively. A-transferase transfers a GalNAc residue from UDP-GalNAc to the precursor H substrate, producing A antigens as defined by the trisaccharide determinant structure, GalNAc␣133(Fuc␣132)Gal13 R. Similarly, B-transferase catalyzes the transfer of a Gal from UDP-Gal to the same H substrate, producing B antigens defined by Gal␣133(Fuc␣132)Gal13 R (2-5). Molecular genetic studies of the human ABO genes have identified two critical single base substitutions that result in amino acid substitutions responsible for the different donor nucleotidesugar substrate specificity between A-and B-transferases. A single base deletion, which shifts the reading frame of codons and abolishes the function of A-transferase, has been identified in most O alleles (6, 7).The ABO genes are expressed in a cell type-specific manner; the isoantigens A, B, and H of blood groups A, B, and O are not confined to red cells only but are also found in most secretions and on some epithelial cells. However, they are absent in connective tissues and the central nervous system (8). ABH antigens are known to undergo drastic changes during development, differentiation, and maturation of normal cells (9). In addition to these physiological processes, profound changes have also been documented in pathological processes such as tumorigenesis. Reduction or complete deletion of A/B antigen expression in bladder and oral cancers has been documented, as well as the apparent onco-developmental expression of the ABH antigens in gastric and distal colon tumors (10 -12). Moreover, the loss of ABH antigens has been correlated with tumor progression of various carcinomas including lung and bladder carcinomas (13-16). Thus, delineation of regulatory mechanism is essential to understand these complicated expression patterns of the ABO genes.In an initial attempt to elucidate the molecular mechanism controlling the expression of the human ABO genes, we isolated several genomic clones that covered the ABO genes over 18 kb 1 (17). A 4.7-kb EcoRI/NcoI 5Ј-upstream fragment flanking the coding sequence in exon 1 of the human ABO gene was subcloned into the promoterless pGL3-basic vector upstream of the lucifer...
Buoyant density gradient centrifugation has been used to separate bacteria from complex food matrices, as well as to remove compounds that inhibit rapid detection methods, such as PCR, and to prevent false-positive results due to DNA originating from dead cells. Applying a principle of buoyant density gradient centrifugation, we developed a method for rapid separation and concentration following filtration and low-and highspeed centrifugation, as well as flotation and sedimentation buoyant density centrifugation, for 12 food-borne pathogens (Salmonella enterica, Escherichia coli, Yersinia enterocolitica, Campylobacter jejuni, Vibrio cholerae O139, Vibrio parahaemolyticus O3K6, Vibrio vulnificus, Providencia alcalifaciens, Aeromonas hydrophila, Bacillus cereus, Staphylococcus aureus, and Clostridium perfringens) in 13 different food homogenates. This method can be used prior to real-time quantitative PCR (RTi-qPCR) and viable-cell counting. Using this combined method, the target organisms in the food samples theoretically could be concentrated 250-fold and detected at cell concentrations as low as 10 1 to 10 3 CFU/g using the RTi-qPCR assay, and amounts as small as 10 0 to 10 1 CFU/g could be isolated using plate counting. The combined separation and concentration methods and RTi-qPCR confirmed within 3 h the presence of 10 1 to 10 2 CFU/g of Salmonella and C. jejuni directly in naturally contaminated chicken and the presence of S. aureus directly in remaining food items in a poisoning outbreak. These results illustrated the feasibility of using these assays for rapid inspection of bacterial food contamination during a real-world outbreak.
We have studied the expression of human histo-blood group ABO genes during erythroid differentiation, using an ex vivo culture of AC133 ؊ CD34 ؉ cells obtained from peripheral blood. 5-Rapid amplification of cDNA ends analysis of RNA from those cells revealed a novel transcription start site, which appeared to mark an alternative starting exon (1a) comprising 27 bp at the 5-end of a CpG island in ABO genes. Results from reverse transcription-PCR specific to exon 1a indicated that the cells of both erythroid and epithelial lineages utilize this exon as the transcription starting exon. Transient transfection experiments showed that the region just upstream from the transcription start site possesses promoter activity in a cell type-specific manner when placed 5 adjacent to the reporter luciferase gene. Results from bisulfite genomic sequencing and reverse transcription-PCR analysis indicated that hypermethylation of the distal promoter region correlated with the absence of transcripts containing exon 1a, whereas hypermethylation in the interspersed repeats 5 adjacent to the distal promoter was commonly observed in all of the cell lines examined. These results suggest that a functional alternative promoter is located between the hypermethylated region of repetitive elements and the CpG island in the ABO genes.In 1900 Karl Landsteiner discovered the ABO blood group system, which is important in blood transfusions and personal identification in criminal investigations (1). Two carbohydrate antigens, A and B, and their antibodies constitute this system. The functional A and B alleles at the ABO genetic locus encode glycosyltransferases ␣133GalNAc transferase (A-transferase) and ␣133Gal transferase (B-transferase), respectively. A-transferase transfers a GalNAc residue from UDP-GalNAc to the precursor H substrate, producing A antigens as defined by the trisaccharide determinant structure GalNAc␣133-(Fuc␣132)Gal13 R. Similarly, B-transferase catalyzes the transfer of a Gal from UDP-Gal to the same H substrate, producing B antigens defined by Gal␣133(Fuc␣132)-Gal13 R (2-5). Molecular genetic studies of human ABO genes have demonstrated that ABO genes consist of at least seven exons spanning over 18 kb of genomic DNA and that two critical single base substitutions in the last coding exon result in amino acid substitutions responsible for the different donor nucleotide sugar substrate specificity between A-and B-transferases. A single base deletion in exon 6 was ascribed to shift the reading frame of codons and to abolish the transferase activity of A-transferase in most O alleles (6 -9).The ABO antigens are expressed in a cell type-specific manner; the isoantigens A, B, and H of blood groups A, B, and O are not confined to red cells but are also found in most secretions and on some epithelial cells. However, they are absent in connective tissues, muscles, and the central nervous system (10). Moreover, ABH antigens are known to undergo drastic changes during development, differentiation, and maturation of cells in epithe...
The expression of the ABO promoter appears to be influenced by the binding of Sp1 or Sp1-like protein(s) in both erythroid and epithelial cell lineages.
We have cloned murine genomic and complementary DNA that is equivalent to the human ABO gene. The murine gene consists of at least six coding exons and spans at least 11 kilobase pairs. Exon-intron boundaries are similar to those of the human gene. Unlike human A and B genes that encode two distinct glycosyltransferases with different donor nucleotide-sugar specificities, the murine gene is a cis-AB gene that encodes an enzyme with both A and B transferase activities, and this cis-AB gene prevails in the mouse population. Cloning of the murine AB gene may be helpful in establishing a mouse model system to assess the functionality of the ABO genes in the future.Histo-blood group A/B antigens are clinically important antigens in blood transfusion and organ transplantation. These antigens are oligosaccharide antigens whose immunodominant structures are defined as GalNAc ␣133 (Fuc ␣132) Gal-and Gal ␣133 (Fuc ␣132) Gal-for A and B antigen, respectively. Functional alleles at the ABO locus encode enzymes that catalyze the final step of synthesis. A alleles encode for A transferase, which transfers the GalNAc residues from the UDPGalNAc nucleotide-sugar to the galactose residue of the acceptor H substrates defined by Fuc ␣132 Gal-. B alleles encode for B transferase that transfers the galactose residue from UDP-galactose to the same H substrates. O alleles are nonfunctional, null alleles. During the past decade, we have been studying the molecular genetic basis of the histo-blood group ABO system (1). From a human gastric carcinoma cell line cDNA library, we were able to clone human A transferase cDNA (2) based on the partial amino acid sequence of the soluble form of A transferase purified from human lung (3). Using cross-hybridization with A transferase cDNA probes, we then cloned B transferase cDNA and nonfunctional O allelic cDNA from cDNA libraries made with RNA from colon adenocarcinoma cell lines that exhibited different ABO phenotypes (4). Possible allele-specific mutations were identified. Four amino acid substitutions were discovered between A and B transferases. O alleles were more homologous to A alleles than to B alleles. A single base deletion was found near the N terminus of the coding sequence in most of the O alleles, which caused the codon frame to shift. This resulted in a truncated protein without glycosyltransferase activity. In addition to the three major alleles (A
We investigated 998 serial Japanese forensic autopsy cases (0-101 years old, mean age 61.7 ± 21.9), with no case selection, using immunohistochemistry to detect cases with progressive supranuclear palsy (PSP). Twenty-nine cases (mean age 82.3 ± 7.2 years, 11 males, 18 females) fulfilled the National Institute of Neuronal Disorders and Stroke (NINDS)-PSP pathological criteria (2.9% of all cases, 4.6% of cases over 60). All had neuronal and glial inclusions in the basal ganglia and brainstem. However, 13 cases had low tau pathology and were categorized as atypical PSP. In addition to PSP pathology, multiple types of astrocytic inclusions and comorbid proteinopathies, particularly a high prevalence of argyrophilic grain disease, were found. All cases had not been diagnosed with PSP and had preserved daily functioning prior to death. However, 14 (48.3%), 11 (37.9%), and 16 (55.2%) cases showed signs of dementia, depressive state, and gait disturbance, respectively. Sixteen accidental death cases (55.2%), including from falls and getting lost, and 11 suicide cases (37.9%) appear to have a relationship with incipient PSP pathology. Cluster analysis using the distribution and amount of 4-repeat-tau pathology classified the cases into three subgroups: Group 1 (10 cases) had typical PSP pathology and seven cases (70.0%) had dementia as the most frequent symptom; Group 2 (7 cases) had significantly higher frequency of gait disorder (6 cases, 85.7%), and less neocortical tau pathology than Group 1; Group 3 (12 cases) had relatively mild PSP pathology and high argyrophilic grain burdens. Granular-shaped astrocytes were the dominant astrocytic inclusion in all cases. We conclude that in forensic cases incipient PSP occurs with a higher prevalence than expected. If these findings can be extrapolated to other population-based cohorts, PSP may be more common than previously thought.
BackgroundLeft ventricular noncompaction (LVNC) has since been classified as a primary genetic cardiomyopathy, but the genetic basis is not fully evaluated. The aim of the present study was to identify the genetic spectrum using next‐generation sequencing and to evaluate genotype–phenotype correlations in LVNC patients.Methods and ResultsUsing next‐generation sequencing, we targeted and sequenced 73 genes related to cardiomyopathy in 102 unrelated LVNC patients. We identified 43 pathogenic variants in 16 genes in 39 patients (38%); 28 were novel variants. Sarcomere gene variants accounted for 63%, and variants in genes associated with channelopathies accounted for 12%. MYH7 and TAZ pathogenic variants were the most common, and rare variant collapsing analysis showed variants in these genes contributed to the risk of LVNC, although patients carrying MYH7 and TAZ pathogenic variants displayed different phenotypes. Patients with pathogenic variants had early age of onset and more severely decreased left ventricular ejection fractions. Survival analysis showed poorer prognosis in patients with pathogenic variants, especially those with multiple variants: All died before their first birthdays. Adverse events were noted in 17 patients, including 13 deaths, 3 heart transplants, and 1 implantable cardioverter‐defibrillator insertion. Congestive heart failure at diagnosis and pathogenic variants were independent risk factors for these adverse events.ConclusionsNext‐generation sequencing revealed a wide spectrum of genetic variations and a high incidence of pathogenic variants in LVNC patients. These pathogenic variants were independent risk factors for adverse events. Patients harboring pathogenic variants showed poor prognosis and should be followed closely.
Background: Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy that is associated with high morbidity and mortality rates. Recently, LVNC was classified into several phenotypes including congenital heart disease (CHD). However, although LVNC and CHD are frequently observed, the role and clinical significance of genetics in these cardiomyopathies has not been fully evaluated. Therefore, we aimed to evaluate the impact on the perioperative outcomes of children with concomitant LVNC and CHD using next-generation sequencing (NGS). Methods: From Japanese probands with LVNC (25 males and 28 females) were enrolled and we screened 182 cardiomyopathy-associated genes in these patients using NGS. Results: The age at diagnosis of the enrolled patients ranged from 0 to 14 years (median: 0.3 months). A total of 23 patients (43.4%) were diagnosed with heart failure, 14 with heart murmur (26.4%), and 6 with cyanosis (11.3%). During the observation period, 31 patients (58.5%) experienced heart failure and 13 (24.5%) developed arrhythmias such as ventricular tachycardia, supraventricular tachycardia, and atrioventricular block. Moreover, 29 patients (54.7%) had ventricular septal defects (VSDs), 17 (32.1%) had atrial septal defects, 10 had patent ductus arteriosus (PDA), and 7 (13.2%) had Ebstein's anomaly and double outlet right ventricle. Among the included patients, 30 underwent surgery, 19 underwent biventricular repair, and 2 underwent pulmonary artery banding, bilateral pulmonary artery banding, and PDA ligation. Overall, 30 genetic variants were identified in 28 patients with LVNC and CHD. Eight variants were detected in MYH7 and two in TPM1. Echocardiography showed lower ejection fractions and more thickened trabeculations in the left ventricle in patients with LVNC and CHD than in age-matched patients with VSDs. During follow-up, 4 patients died and the condition of 8 worsened postoperatively. The multivariable proportional hazards model showed that heart failure, LV ejection fraction of < 24%, LV end-diastolic diameter z-score of > 8.56, and noncompacted-to-compacted ratio of the left ventricular apex of > 8.33 at the last visit were risk factors for survival. Conclusions: LVNC and CHD are frequently associated with genetic abnormalities. Knowledge of the association between CHD and LVNC is important for the awareness of clinical implications during the preoperative and postoperative periods to identify the populations who are at an increased risk of additional morbidity.
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