Yuka Akagi

Ms. Yuka Akagi

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 April 2020 in Scientific Reports
Verified
Journal Article
Open access
PDF file
NMNobuhito Mori
Nobuhito Mori
YAYuka Akagi
Yuka Akagi
YIYukiko Imai
Yukiko Imai
YTYuzo Takayama
Yuzo Takayama
YKYasuyuki S Kida
Yasuyuki S Kida
Although various production methods for 3D vascularised tissues have been developed, constructing capillary-like structures branching from perfusable large channels remains difficult. This study describes a method to fabricate tube-shaped 3D liver-like tissue (tubular liver tissue) with large channels and capillary-like structures using a perfusion device. The perfusion device functions as an interface between the tissue and an external pump, as it has connectors equipped with anchors that hold the tissue in response to its shrinkage, which is accompanied by the self-organisation of capillary-like structures. Histological analysis revealed that perfusion via the large channel induced capillary formation around the channel and maintained proper tissue functions. Accompanied by structural examinations, global gene expression analysis supported this finding; specifically, genes involved in angiogenesis were enriched in the perfused condition. Furthermore, we confirmed the penetrability of the capillary-like structures by infusing India ink, as well as substance exchange by measuring the amounts of secreted albumin. These lines of evidence indicate that our method can be used to construct 3D tissues, which is useful for fields of in vitro tissue regeneration for drug development and regenerative medicine.

8 March 2022 in Cancers
Verified
Journal Article
Open access
PDF file
YMYoshihiro Miyazaki
Yoshihiro Miyazaki
NMNobuhito Mori
Nobuhito Mori
YAYuka Akagi
Yuka Akagi
TOTatsuya Oda
Tatsuya Oda
YKYasuyuki S Kida
Yasuyuki S Kida
Cancer-associated fibroblasts (CAFs) in the tumor microenvironment perform glycolysis to produce energy, i.e., ATP. Since the origin of CAFs is unidentified, it is not determined whether the intracellular metabolism transitions from oxidative phosphorylation (OXPHOS) to glycolysis when normal tissue fibroblasts differentiate into CAFs. In this study, we established an experimental system and induced the in vitro differentiation of mesenchymal stem cells (MSCs) to CAFs. Additionally, we performed metabolomic and RNA-sequencing analyses before and after differentiation to investigate changes in the intracellular metabolism. Consequently, we discovered that OXPHOS, which was the primary intracellular metabolism in MSCs, was reprogrammed to glycolysis. Furthermore, we analyzed the metabolites in pancreatic tumor tissues in a mice model. The metabolites extracted as candidates in the in vitro experiments were also detected in the in vivo experiments. Thus, we conclude that normal tissue fibroblasts that differentiate into CAFs undergo a metabolic reprogramming from OXPHOS to glycolysis. Moreover, we identified the CAF-specific metabolites expressed during metabolic reprogramming as potential future biomarkers for pancreatic cancer.

Verified
Journal Article
Open access
PDF file
YTYuzo Takayama
Yuzo Takayama
YAYuka Akagi
Yuka Akagi
YKYasuyuki S Kida
Yasuyuki S Kida
In vitro derivation of human neurons in the autonomic nervous system (ANS) is an important technology, given its regulatory roles in maintaining homeostasis in the human body. Although several induction protocols for autonomic lineages have been reported, the regulatory machinery remains largely undefined, primarily due to the absence of a comprehensive understanding of the molecular mechanism regulating human autonomic induction in vitro. In this study, our objective was to pinpoint key regulatory components using integrated bioinformatics analysis. A protein–protein interaction network construction for the proteins encoded by the differentially expressed genes from our RNA sequencing data, and conducting subsequent module analysis, we identified distinct gene clusters and hub genes involved in the induction of autonomic lineages. Moreover, we analyzed the impact of transcription factor (TF) activity on target gene expression, revealing enhanced autonomic TF activity that could lead to the induction of autonomic lineages. The accuracy of this bioinformatics analysis was corroborated by employing calcium imaging to observe specific responses to certain ANS agonists. This investigation offers novel insights into the regulatory machinery in the generation of neurons in the ANS, which would be valuable for further understanding and precise regulation of autonomic induction and differentiation.

12 December 2023 in FEBS Open Bio
Verified
Journal Article
Open access
YAYuka Akagi
Yuka Akagi
YTYuzo Takayama
Yuzo Takayama
YNYuma Nihashi
Yuma Nihashi
AYAzusa Yamashita
Azusa Yamashita
RYRisa Yoshida
Risa Yoshida
YKYasuyuki S Kida
Yasuyuki S Kida
Food‐derived biological signals are transmitted to the brain via peripheral nerves through the paracrine activity of gastrointestinal (GI) hormones. The signal transduction circuit of the brain–gut axis has been analyzed in animals; however, species‐related differences and animal welfare concerns necessitate investigation using in vitro human experimental models. Here, we focused on the receptors of five GI hormones (CCK, GLP1, GLP2, PYY, and serotonin (5‐HT)), and established human induced pluripotent stem cell (iPSC) lines that functionally expressed each receptor. Compared to the original iPSCs, iPSCs expressing one of the receptors did not show any differences in global mRNA expression, genomic stability, or differentiation capacities of the three germ layers. We induced parasympathetic neurons from these established iPSC lines to assess vagus nerve activity. We generated GI hormone receptor‐expressing neurons (CCKAR, GLP1R, and NPY2R‐neuron) and tested their responsiveness to each ligand using Ca2+ imaging and microelectrode array recording. GI hormone receptor‐expressing neurons (GLP2R and HTR3A) were generated directly by gene induction into iPSC‐derived peripheral nerve progenitors. These receptor‐expressing neurons promise to contribute to a better understanding of how the body responds to GI hormones via the brain–gut axis, aid in drug development, and offer an alternative to animal studies.

20 January 2022 in Preprints.org
Verified
Preprint
Open access
YMYoshihiro Miyazaki
Yoshihiro Miyazaki
NMNobuhito Mori
Nobuhito Mori
YAYuka Akagi
Yuka Akagi
TOTatsuya Oda
Tatsuya Oda
YKYasuyuki S Kida
Yasuyuki S Kida
Cancer-associated fibroblasts (CAFs) in the tumor microenvironment perform glycolysis to produce energy, i.e., ATP. Since the origin of CAFs is unidentified, it is not determined whether the intracellular metabolism transitions from oxidative phosphorylation (OXPHOS) to glycolysis when normal tissue fibroblasts differentiate into CAFs. In this study, we established an experimental system and induced the in vitro differentiation of mesenchymal stem cells (MSCs) to CAFs. Additionally, we performed metabolomic and RNA-sequencing analyses before and after differentiation to investigate changes in the intracellular metabolism. Consequently, we discovered that OXPHOS, which was the primary intracellular metabolism in MSCs, was reprogrammed to glycolysis. In addition, we identified CAF-specific metabolites that were expressed during this reprogramming and determined their presence in the pancreatic tumor tissues of mouse models. Thus, we conclude that normal tissue fibroblasts that differentiate into CAFs undergo a metabolic reprogramming from OXPHOS to glycolysis. Moreover, we identified the CAF-specific metabolites expressed during metabolic reprogramming as potential future biomarkers for pancreatic cancer.

26 October 2020 in PLOS ONE
Verified
Journal Article
Open access
PDF file
YTYuzo Takayama
Yuzo Takayama
YAYuka Akagi
Yuka Akagi
YSYoichiro Shibuya
Yoichiro Shibuya
YKYasuyuki S Kida
Yasuyuki S Kida
Neural crest cells (NCCs) are a promising source for cell therapy and regenerative medicine owing to their multipotency, self-renewability, and capability to secrete various trophic factors. However, isolating NCCs from adult organs is challenging, because NCCs are broadly distributed throughout the body. Hence, we attempted to directly induce NCCs from human adipose-derived mesenchymal stem cells (ADSCs), which can be isolated easily, using small molecule cocktails. We established a controlled induction protocol with two-step application of small molecule cocktails for 6 days. The induction efficiency was evaluated based on mRNA and protein expression of neural crest markers, such as nerve growth factor receptor (NGFR) and sex-determining region Y-box 10 (SOX10). We also found that various trophic factors were significantly upregulated following treatment with the small molecule cocktails. Therefore, we performed global profiling of cell surface makers and identified distinctly upregulated markers, including the neural crest-specific cell surface markers CD271 and CD57. These results indicate that our chemical treatment can direct human ADSCs to developing into the neural crest lineage. This offers a promising experimental platform to study human NCCs for applications in cell therapy and regenerative medicine.