Biology subjects

Kim, Y.-E.

Publications and source records attributed to Kim, Y.-E..

6 recordsLinked to original sources

bioRxiv2025

Rejuvenation-Responsive and Senolytic-Sensitive Muscle Stem Cells Unveiled by CD200 and CD63 in Geriatric Muscle

Muscle stem cells (MuSCs) are parenchymal cells in skeletal muscle regeneration and maintenance. With aging, MuSCs experience a decline in their regenerative function and reduction in their number. However, recent evidence points to substantial heterogeneity within the aged MuSC population, raising questions about the underlying mechanisms of age-associated dysfunction. Here, we used Pax7CreERT2;RosaYFP mice (MuSCYFP) to label Pax7-expressing MuSCs and chronologically traced MuSCs until geriatric age. Genetic labeling and chronological tracing revealed that the number of YFP+ MuSC remained comparable between young, middle and geriatric ages. At geriatric age, YFP+ MuSCs exhibited reduced expression of traditional MuSC markers such as VCAM1 and PAX7. A previously unrecognized subpopulation emerged, characterized by loss of VCAM1 and low or absent PAX7. Despite their altered marker profile, these cells retained transcriptional signatures of quiescence and myogenic potential, but displayed significantly reduced proliferative and regenerative capacities. They displayed gene expression patterns indicative of senescence-like state and were selectively ablated by senolytic treatment. DHT restored regenerative function in aged mice and re-induced VCAM1 expression in YFP+/Pax7-/low/VCAM1- cells, indicating responsiveness to rejuvenation. Based on their emergence with aging, functional impairment and responsiveness to rejuvenation, we termed this population GERI-MuSCs (Geriatric Emerging Rejuvenation-responsive and Impaired MuSCs). CD63 and CD200 were identified as novel surface markers that together with VCAM1, reliably detect GERI-MuSCs as well as classical Pax7+/VCAM1High MuSCs, providing a tool for comprehensive isolation of MuSCs from aged wild-type mice. Together, our findings provide a refined framework for studying MuSC aging and offer new tools for isolating functionally distinct MuSC subsets from aged skeletal muscle.

developmental biology↗

bioRxiv2024

Muscle-resident mesenchymal progenitors sense and repair peripheral nerve injury via the GDNF-BDNF axis

Fibro-adipogenic progenitors (FAPs) are muscle-resident mesenchymal progenitors that can contribute to muscle tissue homeostasis and regeneration, as well as postnatal maturation and lifelong maintenance of the neuromuscular system. Recently, traumatic injury to the peripheral nerve was shown to activate FAPs, suggesting that FAPs can respond to nerve injury. However, questions of how FAPs can sense the anatomically distant peripheral nerve injury and whether FAPs can directly contribute to nerve regeneration remained unanswered. Here, utilizing single-cell transcriptomics and mouse models, we discovered that a subset of FAPs expressing GDNF receptors Ret and Gfra1 can respond to peripheral nerve injury by sensing GDNF secreted by Schwann cells. Upon GDNF sensing, this subset becomes activated and expresses Bdnf. FAP-specific inactivation of Bdnf (Prrx1Cre; Bdnffl/fl) resulted in delayed nerve regeneration owing to defective remyelination, indicating that GDNF-sensing FAPs play an important role in the remyelination process during peripheral nerve regeneration. In aged mice, significantly reduced Bdnf expression in FAPs was observed upon nerve injury, suggesting the clinical relevance of FAP-derived BDNF in the age-related delays in nerve regeneration. Collectively, our study revealed the previously unidentified role of FAPs in peripheral nerve regeneration, and the molecular mechanism behind FAPs response to peripheral nerve injury.

neuroscience↗

bioRxiv2024

Monosynaptically-interconnected Network Module (MNM) Approach for High-Resolution Brain Sub-Network Analysis

We introduce the Monosynaptically-interconnected Network Module (MNM) approach, an innovative method designed for efficiently analyzing the anatomical structure and functional dynamics of specific brain network modules in vivo. Utilizing an Intein-mediated split-Cre system combined with bidirectional adeno-associated viruses, this technique precisely targets and manipulates monosynaptically interconnected modular subnetworks in freely moving animals. We demonstrate its utility through anatomical and functional mapping of a specific MNM encompassing the prefrontal cortex (PFC), basolateral amygdala (BLA), and intermediary hub regions. Specifically, the MNM approach with Cre-reporter mice visualizes detailed network architecture and enables the tracing of axonal connections among the nodes in the network. Furthermore, integration of the MNM approach with Cre-dependent Ca2+ indicator and multi-fiber photometry in freely moving mice reveals enhanced correlative network activities in social contexts. This versatile technique offers significant potential for advancing our understanding of network functions that underlie complex behaviors, providing a modular network perspective.

neuroscience↗

bioRxiv2022

Plasma miRNA-214 is a predictive candidate biomarker of progression speed in patients with ALS

This study was designed to develop and validate a reliable biomarker to predict the progression speed reflecting immune function of amyotrophic lateral sclerosis (ALS). After establishing the induced microglia model (iMGs) derived from peripheral blood monocytes, comparative studies to find factors related to phagocytic differences between iMGs of patients with rapidly progressive ALS [ALS(R)-iMGs, n = 15] and those of patients with slowly progressive ALS [ALS(S)-iMGs, n = 14] were conducted in the discovery cohort. To validate discovered candidate and whether it could be used as a reliable biomarker predicting the progression speed of ALS, we recruited 132 patients with ALS and 30 age-matched healthy controls as the validation cohort. ALS(R)-iMGs showed impaired phagocytic function. Transcriptomic analysis revealed that the perturbed phagocytosis in ALS(R)-iMGs was related to the decreased expression of NCKAP1 (NCK-associated protein 1) and NCKAP1 overexpression rescued the impaired phagocytic function. miRNA-214-3p targeting NCKAP1 in ALS-iMGs was correlated with progression speed in the discovery cohort. The validation cohort revealed that plasma miRNA-214-3p levels were significantly increased in ALS patients (p < 0.0001, AUC = 0.839), correlated with disease progression speed (p = 0.0005), and distinguished the rapidly progressive subgroup (Q1) from the slowly progressive (Q4, p = 0.029), respectively. Plasma miRNA-214-3p can predict the progression speed in ALS. Plasma miRNA-214-3p could be used as a simple and easily accessible biomarker for predicting the future progression speed related to phagocytic dysfunction in ALS patients.

neuroscience↗

bioRxiv2020

Pyronaridine and artesunate are potential antiviral drugs against COVID-19 and influenza

Since the first human case was reported in Wuhan Province, China in December 2019, SARS-CoV-2 has caused millions of human infections in more than 200 countries worldwide with an approximately 4.01% case-fatality rate (as of 27 July, 2020; based on a WHO situation report), and COVID-19 pandemic has paralyzed our global community. Even though a few candidate drugs, such as remdesivir (a broad antiviral prodrug) and hydroxychloroquine, have been investigated in human clinical trials, their therapeutic efficacy needs to be clarified further to be used to treat COVID-19 patients. Here we show that pyronaridine and artesunate, which are the chemical components of anti-malarial drug Pyramax(R), exhibit antiviral activity against SARS-CoV-2 and influenza viruses. In human lung epithelial (Calu-3) cells, pyronaridine and artesunate were highly effective against SARS-CoV-2 while hydroxychloroquine did not show any effect at concentrations of less than 100 M. In viral growth kinetics, both pyronaridine and artesunate inhibited the growth of SARS-CoV-2 and seasonal influenza A virus in Calu-3 cells. Taken together, we suggest that artesunate and pyronaridine might be effective drug candidates for use in human patients with COVID-19 and/or influenza, which may co-circulate during this coming winter season.

microbiology↗

bioRxiv2019

Mass Cytometry Study on the Heterogeneity in Cellular Association and Cytotoxicity of Silver Nanoparticles in Human Immune Cells

There have been many reports about the adverse effects of nanoparticles (NPs) on the environment and human health. Conventional toxicity assessments of NPs frequently assume uniform distribution of monodisperse NPs in homogeneous cell populations, and provide information on the relationships between the administered dose of NPs and cellular responses averaged for a large number of cells. They may have limitations in describing the wide heterogeneity of cell-NP interactions, caused by cell-to-cell and NP-to-NP variances. To achieve more detailed insight into the heterogeneity of cell-NP interactions, it is essential to understand the cellular association and adverse effects of NPs at single-cell level. In this study, we applied mass cytometry to investigate the interactions between silver nanoparticles (AgNPs) and primary human immune cells. High dimensionality of mass cytometry allowed us to identify various immune cell types and observe the cellular association and toxicity of AgNPs in each population. Our findings showed that AgNPs had higher affinity with phagocytic cells like monocytes and dendritic cells and caused more severe toxic effects than with T cells, B cells and NK cells. Multi-element detection capability of mass cytometry also enabled us to simultaneously monitor cellular AgNP dose and intracellular signaling of individual cells, and subsequently investigate the dose-response relationships of each immune population at single-cell level, which are often hidden in conventional toxicity assays at bulk-cell level. Our study will assist future development of single-cell dose-response models for various NPs and will provide key information for the safe use of nanomaterials for biomedical applications.

biochemistry↗