Fine-tuned cholesterol solubilizer, mono-6-O-α-D-maltosyl-γ-cyclodextrin, ameliorates experimental Niemann-Pick disease type C without hearing loss.

Niemann-Pick disease type C (NPC) is a fatal disorder with abnormal intracellular cholesterol trafficking resulting in neurodegeneration and hepatosplenomegaly. A cyclic heptasaccharide with different degrees of substitution of 2-hydroxypropyl groups, 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD), acts as a strong cholesterol solubilizer and is under investigation for treating this disease in clinical trials, but its physicochemical properties and ototoxicity remain a concern. Here, we evaluated the potential of mono-6-O-α-maltosyl-γ-CD (G2-γ-CD), a single-maltose-branched cyclic octasaccharide with a larger cavity than HP-ß-CD, for treating NPC. We identified that G2-γ-CD ameliorated NPC manifestations in model mice and showed lower ototoxicity in mice than HP-ß-CD. To investigate the molecular mechanisms of action behind the differential ototoxicity of these CDs, we performed cholesterol solubility analysis, proton nuclear magnetic resonance spectroscopy, and molecular modeling, and estimated that the cholesterol inclusion mode of G2-γ-CD maintained solely the 1:1 inclusion complex, whereas that of HP-ß-CD shifted to the highly-soluble 2:1 complex at higher concentrations. We predicted the associations of these differential complexations of CDs with cholesterol with the profile of disease attenuation and of the auditory cell toxicity using specific cell models. We proposed that G2-γ-CD can serve as a fine-tuned cholesterol solubilizer for treating NPC, being highly biocompatible and physicochemically suitable for clinical application.

Role of Dach1 revealed using a novel inner ear-specific Dach1-knockdown mouse model.

The Dach1 gene is expressed in the inner ear of normal mouse embryos in the area that differentiates into the cochlear stria vascularis (SV). We hypothesised that Dach1 downregulation in the inner ear would lead to SV dysplasia. However, because Dach1 knockout is embryonic lethal in mice, the role of Dach1 in the inner ear is unclear. Here, we established inner ear-specific Dach1-knockdown mice and showed that Dach1 downregulation resulted in hearing loss, reduced endocochlear potential and secondary outer hair cell loss. There were no abnormalities in marginal cells and basal cells in the SV or spiral ligament in inner ear-specific Dach1-knockdown mature mice. However, intermediate cell dysplasia and thinning of the SV were observed. Moreover, dynamic changes in the expression of key genes related to the epithelial-mesenchymal transition were observed in the lateral wall of the cochlear epithelium, which differentiated into the SV in inner ear-specific Dach1-knockdown mice at embryonic stages. In summary, suppression of Dach1 expression in the inner ear caused the epithelial-mesenchymal transition in the lateral wall of cochlear epithelium, resulting in loss of intermediate cells in the SV and SV dysplasia.This article has an associated First Person interview with the first author of the paper.

Introduction of glycated albumin measurement for all blood donors and the prevalence of a high glycated albumin level in Japan.

UNLABELLED: (J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00224.x, 2012) Aims/Introduction: The Japanese Red Cross Society introduced measurement of glycated albumin (GA) for all blood donors as a glycemic control marker. The GA levels were examined by sex and age. MATERIALS AND METHODS: GA was measured in 3.14 million blood donors who donated between April 2009 and March 2010. For the reference range for GA, values that were three times the reference range for glycated hemoglobin (Japan Diabetes Society value) were used. All donors were notified of their GA levels. For repeat donors, a comparison was made between the GA levels at the first and second donations to verify the GA change after notification. RESULTS: The mean GA was significantly lower in males than in females in donors aged <60 years. The mean GAs of both sexes increased with age and reached the same level of 14.8% in their 60s. The percentage of donors with prediabetes/diabetes (GA ≥16.5%) was 2.8% in males and 2.3% in females. In the normal high group (15.6% ≤ GA < 16.5%), the mean GA at the second donation was lower by 0.20% than at the first donation. In 42.4% of these donors, GA decreased to the normal range at the second donation. CONCLUSIONS: Overall, 2.7% of otherwise healthy Japanese blood donors had a high GA (GA ≥16.5%). Donor blood screening for GA represents an effective measure to identify people at risk of diabetes. The decrease in the GA level after GA notification might indicate the potential usefulness of this strategy to improve glycemic control among people with high GA.

Photoimmobilized array of panel cells for assay of antibodies.

Antibodies in blood are checked with panel blood cells before blood transfusion. In this investigation, for the first time, a panel cell-microarray was prepared by using a photoimmobilization method. Different types of red blood cells were microarrayed on a plate. A water-soluble photoreactive polymer as a matrix was synthesized by the coupling reaction of azidoaniline with poly(2-methacryloyloxyethylphosphorylcholine-co-methacrylic acid). The polymer was mixed with cells and the mixtures were microspotted on substrate and photoirradiated after drying in air. For the antibody assay, monoclonal antibodies or human serum was added to the cell-arrayed plate and adsorbed antibodies were detected by horseradish peroxidase-labeled secondary antibody, which recognized the adsorbed antibodies. Antibodies specifically adsorbed on the immobilized cells as expected. The aggregation method has been available for this type of assay, but extensive experience was needed to apply it correctly. The method using a cell array will be useful for antibody detection.

Secondary anti-D immunization by Del red blood cells.

BACKGROUND: Recent molecular studies of the RHD gene have revealed that D(el) individuals retain a grossly intact RHD gene or have a portion of RHD in their genomes. No D(el) phenotype has yet been shown to induce a primary or secondary alloanti-D immunization, however. CASE REPORT: A 67-year-old D- Japanese woman with a history of allosensitization from transfusion of D+ red blood cells (RBCs) was negative for anti-D at admission. After she received RBCs from 19 apparently D- donors, she developed anti-D with an 8-fold titer. The titer of anti-D increased further to 128-fold after transfusions of cross-match-compatible D- negative RBCs from 40 donors over the next 2 years. Two of 59 donors were found to be RHD gene-positive and antigen D- with a D(el) phenotype, that is, RHD(K409K). CONCLUSION: This is the first case in which RBCs having the D(el) phenotype induced a secondary alloanti-D immunization. A D- donor with the RHD(K409K) allele was associated with the development of anti-D. Adverse episodes or evidence of hemolysis was not observed after the transfusion of RHD(K409K) RBCs. Further clinical evidence is needed to reveal whether the D(el) phenotype has a clinically relevant potential for anti-D immunization.

A subject with a novel type I bare lymphocyte syndrome has tapasin deficiency due to deletion of 4 exons by Alu-mediated recombination.

HLA class I expression depends on the formation of a peptide-loading complex composed of class I heavy chain; beta(2)-microglobulin; the transporter associated with antigen processing (TAP); and tapasin, which links TAP to the heavy chain. Defects in TAP result in a class I deficiency called the type I bare lymphocyte syndrome (BLS). In the present study, we examined a subject with a novel type I BLS who does not exhibit apparent TAP abnormalities but who has a tapasin defect. The subject's TAPASIN gene has a 7.4-kilobase deletion between introns 3 and 7; an Alu repeat-mediated unequal homologous recombination may be the cause of the deletion. No tapasin polypeptide was detected in the subject's cells. The cell surface class I expression level in tapasin-deficient cells was markedly reduced but the reduction was not as profound as in TAP-deficient cells. These results suggest that tapasin deficiency is another cause of type I BLS.

The clinical significance of human leukocyte antigen (HLA) allele compatibility in patients receiving a marrow transplant from serologically HLA-A, HLA-B, and HLA-DR matched unrelated donors.

To improve the clinical outcome of allogeneic hematopoietic stem cell transplantation from an unrelated donor, the identification of human leukocyte antigen (HLA) alleles responsible for immunologic events such as graft-versus-host disease (GVHD), engraftment failure, and graft-versus-leukemia effect is essential. Genomic typing of HLA-A, -B, -C, -DRB1, and -DQB1 was retrospectively performed in 1298 donor-patient pairs in cases where marrow was donated from serologically HLA-A, -B, and -DR compatible donors. Single disparities of the HLA-A, -B, -C, or -DRB1 allele were independent risk factors for acute GVHD, and the synergistic effect of the HLA-C allele mismatch with other HLA allele mismatches on acute GVHD was remarkable. HLA-A and/or HLA-B allele mismatch was found to be a significant factor for the occurrence of chronic GVHD. HLA class I (A, B, and/or C) allele mismatch caused a significantly higher incidence of engraftment failure than HLA match. Significant association of HLA-C allele mismatch with leukemia relapse was not observed. As the result of these events, HLA-A and/or HLA-B allele mismatch reduced overall survival remarkably in both standard-risk and high-risk leukemia cases, whereas the HLA-C mismatch or HLA-class II (DRB1 and/or DQB1) mismatch did not. Furthermore, multiple mismatch of the HLA locus was found to reduce survival in leukemia cases. Thus, the role of the HLA class I allele in unrelated bone marrow transplantation was elucidated. Notably, HLA-C alleles had a different mode from HLA-A or -B alleles for acute GVHD and survival.