Biology subjects

Lee, C. J.

Publications and source records attributed to Lee, C. J..

6 recordsLinked to original sources

bioRxiv2020

Platycodin D prevents both lysosome- and TMPRSS2-driven SARS-CoV-2 infection in vitro by hindering membrane fusion

An ongoing pandemic of coronavirus disease 2019 (COVID-19) is now the greatest threat to the global public health. Herbal medicines and their derived natural products have drawn much attention to treat COVID-19, but there has been no natural product showing inhibitory activity against SARS-CoV-2 infection with detailed mechanism. Here, we show that platycodin D (PD), a triterpenoid saponin abundant in Platycodon grandiflorum (PG), a dietary and medicinal herb commonly used in East Asia, effectively blocks the two main SARS-CoV-2 infection-routes via lysosome- and transmembrane protease, serine 2 (TMPRSS2)-driven entry. Mechanistically, PD prevents host-entry of SARS-CoV-2 by redistributing membrane cholesterol to prevent membrane fusion, which can be reinstated by treatment with a PD-encapsulating agent. Furthermore, the inhibitory effects of PD are recapitulated by a pharmacological inhibition or gene-silencing of NPC1, which is mutated in Niemann-Pick type C (NPC) patients displaying disrupted membrane cholesterol. Finally, readily available local foods or herbal medicines containing PG root show the similar inhibitory effects against SARS-CoV-2 infection. Our study proposes that PD is a potent natural product for preventing or treating COVID-19 and that a brief disruption of membrane cholesterol can be a novel therapeutic approach against SARS-CoV-2 infection.

pharmacology and toxicology↗

bioRxiv2020

Chromatin accessibility profiles of castration-resistant prostate cancers reveal novel subtypes and therapeutic vulnerabilities

In castration-resistant prostate cancer (CRPC), the loss of androgen receptor (AR)-dependence due to lineage plasticity, which has become more prevalent, leads to clinically highly aggressive tumors with few therapeutic options and is mechanistically poorly defined. To identify the master transcription factors (TFs) of CRPC in a subtype-specific manner, we derived and collected 29 metastatic human prostate cancer organoids and cell lines, and generated ATAC-seq, RNA-seq and DNA sequencing data. We identified four subtypes and their master TFs using novel computational algorithms: AR-dependent; Wnt-dependent, driven by TCF; neuroendocrine, driven by ASCL1 and NEUROD1 and stem cell-like (SCL), driven by the AP-1 family. The transcriptomic signatures of these four subtypes enabled the classification of 370 patients. We find that AP-1 co-operates with the inhibitable YAP/TAZ/TEAD pathway in the SCL subtype, the second most common group of CRPC tumors after AR-dependent. Together, this molecular classification reveals new drug targets and can potentially guide therapeutic decisions.

cancer biology↗

bioRxiv2020

CRISPR/Cas9-mediated gene editing induces neurological recovery in an A53T-SNCA overexpression rat model of Parkinson's disease

To date, no publicly available disease-modifying therapy for Parkinsons disease has been developed. This can be partly attributed to the absence of techniques for in vivo deletion of the SNCA gene (encoding -synuclein), which is one of the key players in Parkinsons disease pathology. In particular, A53T-mutated SNCA (A53T-SNCA) is one of the most studied familial pathologic mutations in Parkinsons disease. Here we utilized a recently discovered genome editing technique, CRISPR/Cas9, to delete A53T-SNCA in vitro and in vivo. Among various CRISPR/Cas9 systems, SaCas9-KKH with a single guide RNA (sgRNA) targeting A53T-SNCA was packaged into adeno-associated virus. Adeno-associated virus carrying SaCas9-KKH significantly reduced A53T-SNCA levels in A53T-SNCA-overexpressed HEK293T cells, without off-target effects on wild-type SNCA. Furthermore, we tested the techniques in vivo therapeutic potential in a viral A53T-SNCA overexpression rat model of Parkinsons disease. Gene deletion of A53T-SNCA significantly prevented the overexpression of -synuclein, dopaminergic neurodegeneration, and parkinsonian motor symptoms, whereas a negative control without sgRNA did not. Our findings propose CRISPR/Cas9 system as a potential therapeutic tool for A53T-SNCA familial Parkinsons disease.

genetics↗

bioRxiv2020

Mutations in TMEM43 cause autosomal dominant auditory neuropathy spectrum disorder via interaction with Connexin-mediated passive conductance channels

Genes that are primarily expressed in cochlear glia-like supporting cells (GLSs) have never been clearly associated with progressive deafness. Herein, we present a novel deafness locus mapped to chromosome 3p25.1 and a new auditory neuropathy spectrum disorder (ANSD) gene TMEM43 mainly expressed in GLSs. We identify p.R372X of TMEM43 by linkage analysis and exome sequencing in two large Asian families. The knock-in (KI) mouse with p.R372X mutation recapitulates a progressive hearing loss with histological abnormalities exclusively in GLSs. Mechanistically, TMEM43 interacts with Cx26 and Cx30 gap junction channels, disrupting the passive conductance current in GLSs in a dominant-negative fashion when the p.R372X mutation is introduced. Based on the mechanistic insights, cochlear implant was performed on two patients and speech discrimination was successfully restored. Our study highlights a pathological role of cochlear GLSs by identifying a novel deafness gene and its causal relationship with ANSD.

genetics↗

bioRxiv2020

TRANsCre-DIONE transdifferentiates scar-forming reactive astrocytes into functional motor neurons

In spinal cord injury (SCI), the scar-forming reactive astrocytes with upregulated GFAP proliferate aberrantly near the injury site, allowing themselves as a prime target for transdifferentiation into neurons to replenish dead neurons. However, the conventional use of GFAP promoter to target reactive astrocytes has two inherent problems: inadvertent conversion of normal astrocytes and low efficiency due to progressive weakening of promoter activity during transdifferentiation. Here, we report that the scar-forming reactive astrocytes are selectively transdifferentiated into neurons with 87% efficiency and 96% specificity via TRANsCre-DIONE, a combination of the split-Cre system under two different promoters of GFAP and Lcn2 and a Cre-loxP-dependent inversion and expression of Neurog2 under the strong EF1 promoter. After SCI, TRANsCre-DIONE caused transdifferentiation into Isl1-positive motor neurons, reduced astrogliosis, enhanced regeneration in surrounding cells, and a significant motor recovery. Our study proposes TRANsCre-DIONE as the next-generation therapeutic approach for patients suffering from SCI. HighlightsTRANsCre-DIONE converts reactive astrocyte into neuron by over-expression of Neurog2 Reactive astrocytes are targeted using split-Cre under two promoters, GFAP and Lcn2 TRANsCre-DIONE reduces reactivity, replaces dead neurons and alleviates symptom of SCI Transdifferentiated-neurons are GABA+ in the striatum and Isl1+ in the spinal cord

neuroscience↗

bioRxiv2020

KDS2010, a newly developed reversible MAO-B inhibitor, as an effective therapeutic candidate for Parkinson's disease

Background and PurposeMonoamine oxidase-B (MAO-B) is a long-standing therapeutic target for Parkinsons disease (PD), however, previous clinical studies demonstrated discouraging effects of currently available irreversible MAO-B inhibitors. Since KDS2010, a novel, potent, selective, and reversible MAO-B inhibitor, has been developed, here we tested its therapeutic potential in animal models of PD. Experimental ApproachWe designed and synthesized -aminoamide derivatives and compared the specificity to MAO-B and reversibility of each compound with KDS2010. To investigate the in vivo therapeutic effect, we used MPTP mouse model with two different regimes of 3-day administration (pre-treatment or post-treatment) and 30-day administration. We assessed the therapeutic potential using behavioral and immunohistochemical analyses. Additionally, the functional recovery by KDS2010 was tested in 6-hydroxydopamine-induced and A53T-alpha-synuclein overexpression models. Lastly, to validate the potential as a clinical drug candidate, we investigated the pharmacokinetics and toxicity of KDS2010 in non-human primates. Key ResultsKDS2010 showed the highest potency, specificity, and reversibility among the -aminoamide derivatives, with high bioavailability (>100%) and BBB permeability. KDS2010 also showed significant neuroprotective and anti-neuroinflammatory effects in the nigrostriatal pathway, leading to an alleviation of MPTP-induced parkinsonism in all administration regimes. In particular, the therapeutic effect of KDS2010 was superior to selegiline, an irreversible MAO-B inhibitor. KDS2010 also showed a potent therapeutic effect in 6-hydroxydopamine and A53T models. Moreover, KDS2010 showed virtually no toxicity or side-effect in non-human primates. Conclusion and ImplicationsKDS2010 shows excellent therapeutic potential and safety in various PD animal models. KDS2010, therefore, could be a next-generation therapeutic candidate for PD. Representative Schematic O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY What is already knownKDS2010 is a recently developed potent, selective, and reversible MAO-B inhibitor. MAO-B is critical for PD pathology through astrocytic GABA and H2O2 synthesis. What this study addsKDS2010 treatment dramatically recovers from PD-related pathology and motor deficit after pre- and post-treatment regimes in several animal models of PD. KDS2010 exhibits low toxicity and excellent pharmacokinetic profile in non-human primates. What is the clinical significance?KDS2010 is a safe and promising therapeutic candidate for Parkinsons disease. Reversible MAO-B inhibitors could be more effective for treatment of Parkinsons disease, overcoming the short-lived actions of irreversible MAO-B inhibitors.

pharmacology and toxicology↗