Cerebral hemorrhage in Fabry's disease

Fabry's disease is an X-linked lysosomal storage disorder resulting from alpha-galactosidase A deficiency. Although ischemic stroke is recognized as an important manifestation of Fabry's disease, hemorrhagic stroke is considered to be rare. Here, we report our recent clinical experience with three hemizygous male patients with Fabry's disease who developed cerebral hemorrhage. One patient had classic type Fabry's disease with p.Ala37Val mutation and others had cerebrovascular variant with p.Glu66Gln mutation. Degeneration of the cerebral small arteries secondary to deposition of glycosphingolipids and aging, in addition to hypertension and antiplatelet/anticoagulant agents, are considered to be contributing factors for hemorrhage. Fabry's disease is frequently associated with not only ischemic but also hemorrhagic stroke, especially in elderly patients. Journal of Human Genetics ( 2010) 55, 259-261; doi:10.1038/jhg.2010.18; published online 19 March 2010ArticleJOURNAL OF HUMAN GENETICS. 55(4):259-261 (2010)journal articl

A weighted q-gram method for glycan structure classification

<p>Abstract</p> <p>Background</p> <p>Glycobiology pertains to the study of carbohydrate sugar chains, or glycans, in a particular cell or organism. Many computational approaches have been proposed for analyzing these complex glycan structures, which are chains of monosaccharides. The monosaccharides are linked to one another by glycosidic bonds, which can take on a variety of comformations, thus forming branches and resulting in complex tree structures. The <it>q</it>-gram method is one of these recent methods used to understand glycan function based on the classification of their tree structures. This <it>q</it>-gram method assumes that for a certain <it>q</it>, different <it>q</it>-grams share no similarity among themselves. That is, that if two structures have completely different components, then they are completely different. However, from a biological standpoint, this is not the case. In this paper, we propose a weighted <it>q</it>-gram method to measure the similarity among glycans by incorporating the similarity of the geometric structures, monosaccharides and glycosidic bonds among <it>q</it>-grams. In contrast to the traditional <it>q</it>-gram method, our weighted <it>q</it>-gram method admits similarity among <it>q</it>-grams for a certain <it>q</it>. Thus our new kernels for glycan structure were developed and then applied in SVMs to classify glycans.</p> <p>Results</p> <p>Two glycan datasets were used to compare the weighted <it>q</it>-gram method and the original <it>q</it>-gram method. The results show that the incorporation of <it>q</it>-gram similarity improves the classification performance for all of the important glycan classes tested.</p> <p>Conclusion</p> <p>The results in this paper indicate that similarity among <it>q</it>-grams obtained from geometric structure, monosaccharides and glycosidic linkage contributes to the glycan function classification. This is a big step towards the understanding of glycan function based on their complex structures.</p

Antibody titers against SARS-CoV-2 decline, but do not disappear for several months

Background: To develop an effective vaccine against a novel viral pathogen, it is important to understand the longitudinal antibody responses against its first infection. Here we performed a longitudinal study of antibody responses against SARS-CoV-2 in symptomatic patients. Methods: Sequential blood samples were collected from 39 individuals at various timepoints between 0 and 154 days after onset. IgG or IgM titers to the receptor binding domain (RBD) of the S protein, the ectodomain of the S protein, and the N protein were determined by using an ELISA. Neutralizing antibody titers were measured by using a plaque reduction assay. Findings: The IgG titers to the RBD of the S protein, the ectodomain of the S protein, and the N protein peaked at about 20 days after onset, gradually decreased thereafter, and were maintained for several months after onset. Extrapolation modeling analysis suggested that the IgG antibodies were maintained for this amount of time because the rate of reduction slowed after 30 days post-onset. IgM titers to the RBD decreased rapidly and disappeared in some individuals after 90 days post-onset. All patients, except one, possessed neutralizing antibodies against authentic SARS-CoV-2, which they retained at 90 days after onset. The highest antibody titers in patients with severe infections were higher than those in patients with mild or moderate infections, but the decrease in antibody titer in the severe infection cohort was more remarkable than that in the mild or moderate infection cohort. Interpretation: Although the number of patients is limited, our results show that the antibody response against the first SARS-CoV-2 infection in symptomatic patients is typical of that observed in an acute viral infection

ショウホウタイ タンパク デアル calreticulin ノ ジカン クウカンテキ カジョウ ハツゲン トランスジェニック マウス ノ サクセイ ト ソノ ヒョウゲンガタ ニ ツイテノ ケントウ

今回我々は、組織の発生や機能獲得におけるcalreticulinの役割を解明するためにcre-loxPシステムを用いて任意の組織特異的にcalreticulinを過剰発現するトランスジェニックマウスを作製した。特に、心臓発生におけるcalreticUlinの役割をさらに解明するために、心臓発生に必要な転写調節因子であるNKx2.5のプロモーター下にcalreticulinを過剰発現するトランスジェニックマウスを作製した。このトランスジェニックマウスを解析することにより、calreticulinの発生、機能獲得における役割を明らかにすることを目的とした

Stable Isotope-Labeled Collagen: A Novel and Versatile Tool for Quantitative Collagen Analyses Using Mass Spectrometry

Collagens are the most abundant proteins in animals and are involved in many physiological/pathological events. Although various methods have been used to quantify collagen and its post-translational modifications (PTMs) over the years, it is still difficult to accurately quantify type-specific collagen and minor collagen PTMs. We report a novel quantitative method targeting collagen using stable isotope-labeled collagen named “SI-collagen”, which was labeled with isotopically heavy lysine, arginine, and proline in fibroblasts culture. We prepared highly labeled and purified SI-collagen for use as an internal standard in mass spectrometric analysis, particularly for a new approach using amino acid hydrolysis. Our method enabled accurate collagen analyses, including quantification of (1) type-specific collagen (types I and III in this paper), (2) total collagen, and (3) collagen PTMs by LC–MS with high sensitivity. SI-collagen is also applicable to other diverse analyses of collagen and can be a powerful tool for various studies, such as detailed investigation of collagen-related disorders

Highly Accurate Quantification of Hydroxyproline-Containing Peptides in Blood Using a Protease Digest of Stable Isotope-Labeled Collagen

Collagen-derived hydroxyproline (Hyp)-containing dipeptides and tripeptides, which are known to possess physiological functions, appear in blood at high concentrations after oral ingestion of gelatin hydrolysate. However, highly accurate and sensitive quantification of the Hyp-containing peptides in blood has been challenging because of the analytical interference from numerous other blood components. We recently developed a stable isotope-labeled collagen named “SI-collagen” that can be used as an internal standard in various types of collagen analyses employing liquid chromatography–mass spectrometry (LC-MS). Here we prepared stable isotope-labeled Hyp-containing peptides from SI-collagen using trypsin/chymotrypsin and plasma proteases by mimicking the protein degradation pathways in the body. With the protease digest of SI-collagen used as an internal standard mixture, we achieved highly accurate simultaneous quantification of Hyp and 13 Hyp-containing peptides in human blood by LC-MS. The area under the plasma concentration–time curve of Hyp-containing peptides ranged from 0.663 ± 0.022 nmol/mL·h for Pro-Hyp-Gly to 163 ± 1 nmol/mL·h for Pro-Hyp after oral ingestion of 25 g of fish gelatin hydrolysate, and the coefficient of variation of three separate measurements was <7% for each peptide except for Glu-Hyp-Gly, which was near the detection limit. Our method is useful for absorption/metabolism studies of the Hyp-containing peptides and development of functionally characterized gelatin hydrolysate

Efficient Absorption of X‑Hydroxyproline (Hyp)-Gly after Oral Administration of a Novel Gelatin Hydrolysate Prepared Using Ginger Protease

Recent studies have reported that oral intake of gelatin hydrolysate has various beneficial effects, such as reduction of joint pain and lowering of blood sugar levels. In this study, we produced a novel gelatin hydrolysate using a cysteine-type ginger protease having unique substrate specificity with preferential peptide cleavage with Pro at the P₂ position. Substantial amounts of X-hydroxyproline (Hyp)-Gly-type tripeptides were generated up to 2.5% (w/w) concomitantly with Gly-Pro-Y-type tripeptides (5%; w/w) using ginger powder. The in vivo absorption of the ginger-degraded gelatin hydrolysate was estimated using mice. The plasma levels of collagen-derived oligopeptides, especially X-Hyp-Gly, were significantly high (e.g., 2.3-fold for Glu-Hyp-Gly, <i>p</i> < 0.05) compared with those of the control gelatin hydrolysate, which was prepared using gastrointestinal proteases and did not contain detectable X-Hyp-Gly. This study demonstrated that orally administered X-Hyp-Gly was effectively absorbed into the blood, probably due to the high protease resistance of this type of tripeptide

Identification of Collagen-Derived Hydroxyproline (Hyp)-Containing Cyclic Dipeptides with High Oral Bioavailability: Efficient Formation of Cyclo(X-Hyp) from X‑Hyp-Gly-Type Tripeptides by Heating

Cyclic dipeptides (2,5-diketopiperazines) are present in a variety of foods and are reported to demonstrate antioxidant, antidepressant, and other beneficial effects. We recently developed a novel collagen hydrolysate characterized by a high content of X-hydroxyproline (Hyp)-Gly-type tripeptides using ginger protease. In the present study, we found that, through heating, X-Hyp-Gly can be easily converted into Hyp-containing cyclic dipeptides. After heating for 3 h at 85 °C and pH 4.8, Ala-Hyp-Gly was almost completely cyclized to cyclo­(Ala-Hyp), in contrast to a slight cyclization of Ala-Hyp. The contents of cyclo­(Ala-Hyp) and cyclo­(Leu-Hyp) reached 0.5–1% (w/w) each in the ginger-degraded collagen hydrolysate under the heating conditions. Oral administration experiments using mice revealed that cyclo­(Ala-Hyp) and cyclo­(Leu-Hyp) were absorbed into the blood at markedly higher efficiencies compared to collagenous oligopeptides, including Pro-Hyp. The high productivity and oral bioavailability of the collagen-specific cyclic dipeptides suggest significant health benefits of the heat-treated ginger-degraded collagen hydrolysate

Production of a novel wheat gluten hydrolysate containing dipeptidyl peptidase-IV inhibitory tripeptides using ginger protease

<p>Wheat gluten is a Pro-rich protein complex comprising glutenins and gliadins. Previous studies have reported that oral intake of enzymatic hydrolysates of gluten has beneficial effects, such as suppression of muscle injury and improvement of hepatitis. Here, we utilized ginger protease that preferentially cleaves peptide bonds with Pro at the P₂ position to produce a novel type of wheat gluten hydrolysate. Ginger protease efficiently hydrolyzed gluten, particularly under weak acidic conditions, to peptides with an average molecular weight of <600 Da. In addition, the gluten hydrolysate contained substantial amounts of tripeptides, including Gln-Pro-Gln, Gln-Pro-Gly, Gln-Pro-Phe, Leu-Pro-Gln, and Ser-Pro-Gln (e.g. 40.7 mg/g at pH 5.2). These gluten-derived tripeptides showed high inhibitory activity on dipeptidyl peptidase-IV with IC₅₀ values of 79.8, 70.9, 71.7, 56.7, and 78.9 μM, respectively, suggesting that the novel gluten hydrolysate prepared using ginger protease can be used as a functional food for patients with type 2 diabetes.</p> <p>Production of DPP-IV inhibitory tripeptides from gluten using ginger protease.</p