Biology subjects

Hwang, D. W.

Publications and source records attributed to Hwang, D. W..

5 recordsLinked to original sources

bioRxiv2023

Spatial transcriptomic brain imaging reveals the effects of immunomodulation therapy upon specific regional brain cells in mouse dementia model

Increasing evidence of brain-immune crosstalk raises expectations for the efficacy of novel immunotherapies in Alzheimers disease (AD), but the lack of methods to understand brain tissues make it difficult to examine therapeutics. Here, we investigated the changes of spatial transcriptomic signatures and brain cell type using the 10x Genomics Visium platform in immune modulated AD models by various treatments. To proceed with an analysis suitable for a single spot-based transcriptomics, we first organized a workflow for segmentation of neuroanatomical regions, establishment of appropriate gene combinations, and comprehensive review of altered brain cell signatures. Ultimately, we investigated spatial transcriptomic changes following administration of immunomodulators, NK cell supplements and anti-CD4 antibody, that ameliorate behavior impairment, and designated brain cells and regions showing probable associations with behavior changes. We provided the customized analytic pipeline into an application named STquantool. Thus, we anticipate that our approach can help researchers to interpret real action of drug candidate by simultaneously investigating the dynamics of all transcripts for development of novel AD therapeutics.

neuroscience↗

bioRxiv2021

Extracellular vesicles induce aggressive phenotype of luminal breast cancer cells by PKM2 phosphorylation

The aerobic glycolysis is a hallmark of cancer glucose metabolism. Several studies have suggested that cancer-derived extracellular vesicles (EVs) can modulate glucose metabolism in adjacent cells and promote disease progression. Here we suggest that EVs originated from cancer cell with highly glycolytic activity can modulate glucose metabolism in the recipient cancer cells with relative low glycolytic activity, and further induce cell proliferation. Two types of breast cancer cell lines with different levels of glycolytic activity, MDA-MB-231 of a claudin low-type breast cancer cell and MCF7 of luminal type breast cancer cell, were selected and co-cultured using indirect co-culture system such as transwell system or microfluidic system. Glucose uptake of the recipient MCF7 cells was markedly increased after co-culture with MDA-MB-231 cells. MCF7 cells after co-culture with MDA-MB-231-tdTomato cells represented multiple tdTomato signal inside the cell, which proved that EVs originated from MDA-MB-231-tdTomato were transferred to MCF7 cell. In addition, serine phosphorylation of PKM2 necessary for tumorigenesis was highly activated, and tyrosine phosphorylation of PKM2 suggesting activated aerobic glycolysis was also increased in the co-cultured MCF7 cells. Proteomic profiling of the co-cultured MCF7 cells revealed the proliferation and dedifferentiation of MCF7 cells, and further confirmed epithelial-mesenchymal transition (EMT), which is a key phenomenon for cancer metastasis. In the transcriptomic analysis, glycolysis increased in co-cultured MCF7 cells, and the component analysis of genes associated with glycolysis revealed that the next major component after cytoplasm was extracellular exosome. Proteomic analysis of EVs revealed that there were important proteins in the EV such as EGFR, ERBB2 and MAPK for phosphorylating PKM2. This phenomenon suggests the potential for aggressive cancer cells to affect other cancer cells through EV mediators.

cancer biology↗

bioRxiv2019

Reconfiguration of neuronal subpopulation associated with disease-associated microglia in human Alzheimer’s disease brain

There is a growing evidence that a subset of microglia, disease-associated microglia (DAM), is crucially involved in the onset and progression of Alzheimer Disease (AD). However, it has been challenging to comprehensively know how DAM affects neuronal loss and reconstitute the complicated cellular composition. Here, we describe the relationship between neuronal reconfiguration and microglia by digitally dissecting the human brain transcriptome. We observed DAM enrichment associated with neuronal loss and the degree of amyloid deposits, which was commonly found in different brain regions. The neuronal subtype analyses showed that DAM enrichment was correlated with the proportion of two excitatory neurons located in the cortical layer 4. The direction of these relations was opposite, which implied excitatory neuronal reconfiguration in the specific cortical layer. Our results suggested immune reaction represented by DAM might mediate the reconfiguration of cellular components in AD, which may eventually have implications for diagnostics and therapeutics.\n\nOne sentence summaryThe enrichment of disease-associated microglia signature is associated with the reconfiguration of neuronal subtypes, particularly excitatory neurons in the cortical layer 4.

neuroscience↗

bioRxiv2018

Graphene-oxide quenching-based molecular beacon imaging of exosome-mediated transfer of neurogenic miR-193a on microfluidic platform

A microRNA (miR-193a) was found to be transferred in the exosomes of differentiated neural progenitors to undifferentiated clones. Graphene-oxide (GO) quenching-based molecular beacon was developed to detect RNAs in living cells and tissues quickly and sensitively. Here, we applied GO quencher-based molecular beacon sensor to visualize neurogenic miR-193a levels delivered via exosome during cell-non-autonomous neurogenesis of neural progenitor cells on microfluidic platform. Fluorescence signals of FAM-labeled peptide nucleic acid (PNA) against miR-193a quenched by GO nanosheets (FAM-PNA193a-GO) were recovered in undifferentiated recipient cells differentiated to the neuronal lineage by exosome-mediated neurogenesis 3 days after co-culture with differentiated donor cells. We propose that molecular beacon imaging using PNA-GO complex can be used to visualize individual cellular expression of mature microRNAs revealing their precise spatial localization and temporal sequences by the intercellular exosome delivery of messages to undergo processes such as cell-non-autonomous neurogenesis.

cell biology↗

bioRxiv2017

Graphene Oxide-Quenching-Based Fluorescence In Situ Hybridization (G-FISH) To Detect RNA In Tissue: Simple And Fast Tissue RNA Diagnostics

FISH-based RNA detection in paraffin-embedded tissue can be challenging, with complicated procedures producing uncertain results and poor image quality. Here, we developed a robust RNA detection method based on graphene oxide (GO) quenching and recovery of fluorescence in situ hybridization (G-FISH) in formalin-fixed paraffin-embedded (FFPE) tissues. Using G-FISH technique, the long noncoding BC1 RNA, {beta}-actin mRNA, miR-124a and miR-21 could be detected in the cytoplasm of a mouse brain, primary hippocampal neurons, and glioblastoma multiforme tumor tissues, respectively. G-FISH showed the increased BC1 RNA level in individual hippocampal neurons of Alzheimers disease brain. The fluorescence recovered by G-FISH correlated highly with the amount of miR-21, as measured by real time RT-PCR. We propose G-FISH as a simple, fast, inexpensive, and sensitive method for RNA detection, with very low background, which could be applied to a variety of researches or diagnostic purposes.

molecular biology↗