Biology subjects

Ochiya, T.

Publications and source records attributed to Ochiya, T..

8 recordsLinked to original sources

bioRxiv2025

Therapeutic ability of extracellular vesicles derived from angio-miRNA-modified mesenchymal stromal cells in ischemic animal models

BackgroundRegenerative therapy using extracellular vesicles (EVs) is expected to be an option for supportive therapy of chronic limb-threatening ischemia. In this study, we examined the angiogenic potential of EVs derived from genetically modified MSCs, focusing on the angio-miRNAs in these vesicles. MethodsBone marrow mesenchymal stromal cells (BM-MSCs) were transfected with a lentiviral vector containing specific angio-miRNAs (miRNA-126, -135b, or -210). EVs were separated from the culture medium of BM-MSCs via ultracentrifugation. The quality and quantity of the EVs were evaluated using nanoparticle tracking analysis, fluorometry, and an ExoScreen assay. Tube formation assays were conducted using human umbilical vein endothelial cells to assess the angiogenic potency of the EVs in vitro. The EVs were injected into the ischemic hind limb muscles of mice. The grades of limb ischemia, blood perfusion, and muscle tissues were analyzed to assess the angiogenic potency of the EVs in vivo. ResultsAngio-miRNAs were overexpressed in MSCs transfected with a lentiviral vector. Tube formation was significantly enhanced when endothelial cells were cultured with the EVs (P < 0.05). Compared to non-contact co-culture with BM-MSCs, EVs derived from modified BM-MSCs significantly promoted tube formation in endothelial cells (P < 0.05). The severity of limb ischemia on day 7 was alleviated when a combination of two or three EVs derived from modified BM-MSCs was injected compared with native EVs. Toe blood perfusion on day 14 significantly recovered when a combination of two or three EVs derived from modified BM-MSCs was injected (P < 0.05). Tissue analysis revealed that the number of newly formed endothelial cells in ischemic muscles increased when a combination of two or three EVs derived from modified BM-MSCs was injected. ConclusionsThe use of a combination of EVs derived from genetically modified MSCs stimulated angiogenesis both in vitro and in vivo.

cell biology↗

bioRxiv2024

Stress-induced brain extracellular vesicles ameliorate anxiety behaviour.

Extracellular vesicles (EVs), nano particles secreted by all types of cells, serve as a communication network, carrying information through the bloodstream to distant cells1,2. Notably, brain cells secrete EVs that play a crucial role in regulating neurological functions3-5. Meanwhile the brain detects acute stress and activates mechanisms to enhance stress resistance and maintain homeostasis6,7. However, the specific contribution of brain-derived extracellular vesicles (BDEVs) in modulating the stress response remains elusive. Here we found that administration of the acute stress-induced BDEVs to mice reduced anxiety-related behaviours, and this reduction was also induced by the administration of only three microRNAs (miRNAs) (miR-199a-3p, miR-99b-3p and miR-140-5p) included in the acute stress-induced BDEVs. Furthermore, we showed that miR-199a-3p contributes to the mechanism of the anxiolytic effect through the suppression of Mecp2 in neurons. These findings elucidate the role of BDEVs in modulating mental activity under acute stress and provide insights into the underlying molecular mechanisms. Our results open up new avenues for therapeutic strategies in the treatment of anxiety disorders using EVs or miRNAs.

animal behavior and cognition↗

bioRxiv2023

Evidence for in vitro extensive proliferation of adult hepatocytes and biliary epithelial cells

Over the last several years, a method has emerged which endows adult hepatocytes with in vitro proliferative capacity, producing chemically-induced liver progenitors (CLiPs). However, a recent study questioned the origin of these cells, suggesting that resident liver progenitor cells, but not hepatocytes, proliferate. Here, we provide lineage tracing-based evidence that adult hepatocytes acquire proliferative capacity in vitro. Unexpectedly, we also found that the CLiP method allows biliary epithelial cells to acquire extensive proliferative capacity. Interestingly, after long-term culture, hepatocyte-derived cells (hepCLiPs) and biliary-derived cells (bilCLiPs) become similar in their gene expression patterns, and they both exhibit differentiation capacity to form hepatocyte-like cells. Finally, we provide evidence that hepCLiPs can repopulate chronically injured mouse livers, reinforcing our earlier argument that CLiPs can be a cell source for liver regenerative medicine. Moreover, this study offers bilCLiPs as a potential cell source for liver regenerative medicine.

cell biology↗

bioRxiv2022

Aberrant regulation of serine metabolite drives extracellular vesicle release and cancer progression

Cancer cells secrete extracellular vesicles (EVs) to regulate cells in the tumor microenvironment to benefit their own growth and survive in the patients body. Although emerging evidence has demonstrated the molecular mechanisms of EV release, regulating cancer-specific EV secretion remains challenging. In this study, we applied a microRNA library to reveal the universal mechanisms of EV secretion from cancer cells. Here, we identified miR-891b and its direct target gene, phosphoserine aminotransferase 1 (PSAT1), which promotes EV secretion through the serine-ceramide synthesis pathway. Inhibition of PSAT1 affected EV secretion in multiple types of cancer, suggesting that the miR-891b/PSAT1 axis shares a common mechanism of EV secretion from cancer cells. Interestingly, aberrant PSAT1 expression also regulated cancer metastasis via EV secretion. Our data link between the PSAT1-controlled EV secretion mechanism and cancer metastasis and show the potential of this mechanism as a therapeutic target in multiple types of cancer.

cancer biology↗

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↗

bioRxiv2019

miR-26a regulates extracellular vesicle secretion from prostate cancer cells via targeting SHC4, PFDN4 and CHORDC1

Extracellular vesicles (EVs) are known to be involved in intercellular communication during cancer progression; thus, elucidating the detailed mechanism will contribute to the development of a novel strategy for EV-targeted cancer treatment. However, the biogenesis of EVs in cancer cells is not completely understood. MicroRNAs (miRNAs) regulate a variety of physiological and pathological phenomena; thus, miRNAs could regulate EV secretion. Here, we performed high-throughput miRNA-based screening to identify the regulators of EV secretion using an ExoScreen assay. By using this miRNA-based screening, we identified miR-26a, which was reported as a tumor suppressive miRNA, as a miRNA involved in EV secretion from prostate cancer (PCa) cells. In addition, we found that the SHC4, PFDN4, and CHORDC1 genes regulate EV secretion in PCa cells. Suppression of these genes by siRNAs significantly inhibited the secretion of EVs in PCa cells. Furthermore, the progression of PCa cells was inhibited in an in vivo study. On the other hand, injection of EVs isolated from PCa cells partially rescued this suppressive effect on tumor growth. Taken together, our findings suggest that miR-26a regulates EV secretion via targeting SHC4, PFDN4, and CHORDC1 in PCa cells, resulting in the suppression of PCa progression.

cancer biology↗

bioRxiv2019

Generation of human hepatic progenitor cells with regenerative and metabolic capacities from primary hepatocytes

Hepatocytes are regarded as the only effective cell source for cell transplantation to treat liver diseases; however, their availability is limited due to a donor shortage. Thus, a novel cell source must be developed. We recently reported that mature rodent hepatocytes can be reprogrammed into progenitor-like cells with a repopulative capacity using small molecule inhibitors. Here, we demonstrate that hepatic progenitor cells can be obtained from human infant hepatocytes using the same strategy. These cells, named human chemically induced liver progenitors (hCLiPs), had a significant repopulative capacity in injured mouse livers following transplantation. hCLiPs redifferentiated into mature hepatocytes in vitro upon treatment with hepatic maturation-inducing factors. These redifferentiated cells exhibited cytochrome P450 (CYP) enzymatic activities in response to CYP-inducing molecules and these activities were comparable with those in primary human hepatocytes. These findings will facilitate liver cell transplantation therapy and drug discovery studies.

cell biology↗

bioRxiv2017

A subgroup of mitochondrial extracellular vesicles discovered in human melanoma tissues are detectable in patient blood

Extracellular vesicles (EVs), including exosomes and microvesicles, are secreted from all cells, and convey messages between cells in health and disease. However, the diversity of EV subpopulations are only beginning to be explored. Since EVs have been implicated in tumor microenvironmental communication, we started to determine the diversity of EVs specifically in this tissue. To do this, we isolated EVs directly from patient melanoma metastatic tissues. Using EV membrane isolation and mass spectrometry analysis, we discovered enrichment of mitochondrial membrane proteins in the melanoma tissue-derived EVs, compared to non-melanoma-derived EVs. Specifically, EVs positive for a combination of the two mitochondrial inner membrane proteins MT-CO2 (mitochondrial genome) and COX6c (nuclear genome) were detected in the plasma of melanoma patients, and in ovarian and breast cancer patients. Furthermore, this subpopulation of EVs, contains active mitochondrial enzymes. Our findings show that tumor tissues are enriched in EVs with mitochondrial proteins and enzymatic activity, and these EVs can be detected in blood.

cancer biology↗