Biology subjects

Hara, H.

Publications and source records attributed to Hara, H..

4 recordsLinked to original sources

bioRxiv2021

The first transchromosomic rat model with human chromosome 21 shows robust Down syndrome features

Progress in earlier detection and symptom management has increased life expectancy and quality of life in people with Down syndrome (DS). However, no drug has been approved to help individuals with DS live independently and fully. Although rat models could support more robust physiological, behavioral, and toxicology analysis than mouse models during preclinical validation, no DS rat model is available due to technical challenges. We developed the first transchromosomic rat model of DS, TcHSA21rat, which contains a freely segregating, EGFP-inserted, human chromosome 21 (HSA21) with >93% of its protein coding genes. RNA-Seq of neonatal forebrains demonstrates that TcHSA21rat not only expresses HSA21 genes but also has an imbalance in global gene expression. Using EGFP as a marker for trisomic cells, flow cytometry analyses of peripheral blood cells from 361 adult TcHSA21rat animals show that 81% of animals retain HSA21 in >80% of cells, the criterion for a "Down syndrome karyotype" in people. TcHSA21rat exhibits learning and memory deficits and shows increased anxiety and hyperactivity. TcHSA21rat recapitulates well-characterized DS brain morphology, including smaller brain volume and reduced cerebellar size. In addition, the rat model shows reduced cerebellar foliation, a prominent feature of DS that is not observed in DS mouse models. Moreover, TcHSA21rat exhibits anomalies in craniofacial morphology, heart development, husbandry, and stature. TcHSA21rat is a robust DS animal model that can facilitate DS basic research and provide a unique tool for preclinical validation to accelerate DS drug development.

genetics↗

bioRxiv2021

Transcriptomic analysis of astaxanthin hyper-producing Coelastrum sp. mutant obtained by chemical mutagenesis

A newly isolated green microalga, Coelastrum sp. has the capability to produce and accumulate astaxanthin under various stress conditions. At present, a mutant G1-C1 of Coelastrum sp. obtained through chemical mutagenesis using ethyl methane sulfonate displayed an improvement in astaxanthin accumulation, which was 2-fold higher than that of the wild-type. However, lack of genomic information limits the understanding of the molecular mechanism that leads to a high level of astaxanthin in the mutant G1-C1. In this study, transcriptome sequencing was performed to compare the transcriptome of astaxanthin hyper-producing mutant G1-C1 and wild-type of Coelastrum sp. with respect to astaxanthin biosynthesis. This is to clarify why the mutant produced higher astaxanthin yield compared to the wild-type strain. Based on the transcriptomic analysis, the differentially expressed genes involved in astaxanthin biosynthesis were significantly upregulated in the mutant G1-C1 of Coelastrum sp. Genes coding phytoene synthase, phytoene desaturase,{zeta} -carotene desaturase, and lycopene {beta}-cyclase involved in {beta}-carotene biosynthesis in the mutant cells were upregulated by 10-, 9.2-, 8.4-, and 8.7-fold, respectively. Genes coding beta-carotene ketolase and beta-carotene 3-hydroxylase involved in converting {beta}-carotene into astaxanthin were upregulated by 7.8- and 8.0-fold, respectively. In contrast, the lycopene {varepsilon}-cyclase gene was downregulated by 9.7-fold in mutant G1-C1. Together, these results contribute to higher astaxanthin accumulation in mutant G1-C1. Overall, the data in this study provided molecular insight for a better understanding of the differences in astaxanthin biosynthesis between the wild-type and mutant G1-C1 strains.

molecular biology↗

bioRxiv2020

Comparison of porcine corneal decellularization methods and importance of preserving corneal limbus through decellularization

BackgroundThe aim of this study is to compare the three previously applied, conventional porcine corneal decellularization methods and to demonstrate the importance of preserving the corneal limbus through decellularization. MethodsFresh, wild-type (with or without) limbus porcine corneas were decellularized using three different methods, including (i) sodium dodecyl sulfate (SDS), (ii) hypertonic saline (HS), and (iii) N2 gas (NG). Post-treatment evaluation was carried out using histological, residual nuclear material, and ultrastructural analyses. Glycerol was used to help reduce the adverse effects of decellularization. The corneas were preserved for two weeks in cornea storage medium. ResultsAll three decellularization methods reduced the number of keratocytes at different rates in the stromal tissue. However, all methods, except SDS, resulted in the retention of large numbers of cells and cell fragments. The SDS method (0.1% SDS, 48h) resulted in almost 100% decellularization in corneas without limbus. Low decellularization capacity of the NG method (<50%) could make it unfavorable. Although HS method had a more balanced damage-decellularization ratio, its decellularization capacity was lower than SDS method. Preservation of the corneoscleral limbus could partially prevent structural damage and edema, but it would reduce the decellularization capacity. ConclusionOur results suggest that SDS is a very powerful decellularization method, but it damages the cornea irreversibly. Preserving the corneoscleral limbus reduces the efficiency of decellularization, but also reduces the damage.

bioengineering↗

bioRxiv2020

Human bronchial epithelial cell-derived extracellular vesicle therapy for pulmonary fibrosis via inhibition of TGF-β-WNT crosstalk

Idiopathic pulmonary fibrosis (IPF) is characterized by devastating and progressive lung parenchymal fibrosis, resulting in poor patient prognosis. An aberrant recapitulation of developmental lung gene expression, including genes for transforming growth factor (TGF)-{beta} and WNT, has been widely implicated in the pathogenic IPF wound healing process that results from repetitive alveolar epithelial injury. Extracellular vesicles (EVs) have been shown to carry bioactive molecules and to be involved in various physiological and pathological processes. Here, we demonstrate that, by attenuating WNT signaling, human bronchial epithelial cell-derived EVs (HBEC EVs) inhibit TGF-{beta} mediated induction of both myofibroblast differentiation and lung epithelial cellular senescence. This effect of HBEC EVs is more pronounced than that observed with mesenchymal stem cell-derived EVs. Mechanistically, the HBEC EV microRNA (miRNA) cargo is primarily responsible for attenuating both myofibroblast differentiation and cellular senescence. This attenuation occurs via inhibition of canonical and non-canonical WNT signaling pathways. Among enriched miRNA species present in HBEC EVs, miR-16, miR-26a, miR-26b, miR-141, miR-148a, and miR-200a are mechanistically involved in reducing WNT5A and WNT10B expression in LFs, and in reducing WNT3A, WNT5A, and WNT10B expression in HBECs. Mouse models utilizing intratracheal administration of EVs demonstrate efficient attenuation of bleomycin-induced lung fibrosis development accompanied by reduced expression of both {beta}-catenin and markers of cellular senescence. These findings indicate that EVs derived from normal resident lung HBECs may possess anti-fibrotic properties. They further suggest that, via miRNA-mediated inhibition of TGF-{beta}-WNT crosstalk, HBEC EVs administration can be a promising anti-fibrotic modality of treatment for IPF.

molecular biology↗