Leading Medical Innovation
Today, we are facing the challenge of not only tackling a wide variety but also new types of diseases as our society continues to develop. Multidisciplinary research technologies have been conducted to deal with the current situations.
Based on omics studies such as metabolomics, proteomics, genomics, and systems biology, molecular recognition research center conducts research on study of molecular mechanism of diseases, and identification of molecular biomarkers for disease diagnosis and drug monitoring. Discovery of new drug action points for treatment through validation of their biological functions in various disease physiology is also ongoing.
Our research interests are also focused on developing the On-Demand detection platforms of biomarkers through material science and chemical biology, and to link them to clinical intermediation research.
Man Ho Choi, Ph.D.
Head, Principal Research Scientist
Figure. Multiplex miRNA profiling based on particle RT-qPCR. (a) Bright-field microscopic image. Each target is distinguished by codes. Scale bar is 500 μm. (b) Encoded particles for each target. (c) Image sequence during amplification. The fluorescence intensity of each particle was recorded. (d) Amplification curves from two independent multiplex particle RT-qPCR assays. (e) A photograph of highly multiplexed particle RT-qPCR chip.
Title : In-particle stem-loop RT-qPCR for specific and multiplex microRNA profiling
PI : Sang Kyung Kim
MicroRNAs (miRNAs) are small non-coding RNAs that can regulate the translation of messenger RNAs (mRNAs) through binding with target mRNAs. Although several approaches have been reported to profile miRNAs so far, they still have the limitations such as poor multiplicity or specificity. Here we report a novel method of miRNA profiling with particle-based multiplex quantitative reverse transcription polymerase chain reaction (RT-qPCR). To achieve target-specific reaction in a particle, the stem-loop RT primer and forward primer for each target miRNA were chemically immobilized to the particle. Target-specific cDNA synthesis proceeds with the stem-loop RT primer and then qPCR subsequently proceeds with the forward primer to rapidly achieve a quantitative result. High-fidelity multiplex assay was also accomplished in a single PCR process by loading multiple particles for each specific miRNA. The method for primer supply in the particles, involving confinement of the target-specific RT and PCR primers in the matrix of particles, led to the reduction of nonspecific reactions and improved the selectivity of the miRNA assay while minimizing labor in a multiple target assay. Specifically, this particle-based assay enabled the differentiation of mature miRNA from precursor with selectivity of 270:1 in terms of amplification speed. This advanced method also showed good discrimination among highly homologous let-7 family members, with cross-reaction rates of less than 5%. We demonstrated a very simple process of five-plex miRNA profiling in total RNA, and the measured changes in expression level were consistent with those from a conventional singleplex method. (Biosensors and Bioelectronics, 2020)
Figure. Design of an integrated sampling/monitoring platform. (A) Experimental setup of bioaerosol sampling in the artificial aerosolization chamber (B) Working principle of airborne pathogen sampling/monitoring kit incorporated into the air sampler (C) Schemetic illustration of airborne pathogen detection in indoor spaces
Title : An Integrated Bioaerosol Sampling/Monitoring Platform: On-Site Detection of Airborne Viruses.
PI : Joonseok Lee
Serious pandemic diseases have previously been associated with airborne pathogen transmission. Severe acute respiratory syndrome (SARS) in 2003 resulted in greater than 700 fatalities in only a few months, and influenza A (H1N1) virus in 2009 caused over 10,000 infections across 41 countries. There is thus a great need for simple, portable, and cost-effective detection techniques for airborne pathogens. Rapid, accurate, and reliable diagnostics are crucial for monitoring and preventing the spread and emergence of airborne pathogens. Although advances have been made to point-of-care systems, these improvements have not been widely applied to detection of airborne viruses due to aerosol sampling requirements as well as technical barriers to combining sampling and analysis methods. We have resolved these problems and have produced an integrated bioaerosol sampling/monitoring platform for on-site detection of airborne viruses. The platform was designed as a portable system, enabling low-cost assembly and employing a disposable detection kit in a compact size air sampler. We tested our bioaerosol sampling/monitoring platform by artificially aerosolizing polystyrene beads, MS2 viruses, and Avian influenza viruses (AIVs) in the closed chamber, which controls temperature and humidity. Bioaerosols containing airborne virus were collected on the sampling zone of the strip, and then analyzed by near-infrared (NIR) emission of synthesized nanoprobes. The device was effective for detecting clinical samples of H9N2 virus collected from chickens. We believe that this integrated sampling/monitoring device will be highly valuable for the prevention, diagnosis, or rapid response to critical pandemic diseases in specific closed spaces (e.g., on an airplane, or in a hospital ward, or in an animal/farm/food processing facilities) where respiratory, livestock epidemic-related viruses or airborne bacteria are prevalent with risk of continually circulating aerosol. (ACS Sensors, 2020)
Figure. Cell-imaging of mitochondria and lysosome using fluorescent probes for subcellular organelle.
Title : BODIPY Based Fluorescent Probes for Imaging and Subcellular Chemical Proteomics in Living Cells.
PI : Jun-Seok Lee / Dhiraj P. Murale
Researchers are extensively trying to achieve comprehensive protein lists for the sub-cellular regions by using mass spectrometry. Organellar-based proteomics has emerged out to be the most rapidly advancing methods to obtain the protein list and functional analysis of those subcellular proteins. To study Organellar-based proteomics, identification and differentiation of different subcellular compartments is crucial factor. Proteins associated with the specific organelle region for example, nucleus, endoplasmic reticulum (ER), Golgi complex, mitochondria and lysosome – are active membrane-bounded partitions that have diverse structures and functions more-over govern the structure and function of that particular subcellular region. In our recent work we have developed a design of a novel photo-crosslinking fluorophore called photo-crosslinking BODIPY fluorophore (pcBD). The main success for this pcBD design is, this works better than benzophenone also it has BODIPY fluorophore so can be used as fluorescent tag. Also, we have studied the photocrosslinking of pcBD with the purified proteins. The major advantage of pcBD for photo-activated protein labeling is the capability to attach BODIPY fluorophore at any kinds of target proteins depending on the spatial vicinity. Likewise, we proved the utility of photo-crosslinking fluorophore for spatiotemporal protein labeling in complex mixture.
We envisioned to target the specific organelle, to study the protein tagging and identification of the proteins in that subcellular region. To encounter the proposed objective, we have designed and synthesized the organelle specific pcBD molecules by making the simple and the effective chemical modification in the pcBD probes. As a proof of concept, we have successfully improved the pcBD probes with pyridinium salt, morpholino moiety, and for mitochondria and lysosome respectively.
The Molecular Recognition Research Center has three main research scopes:
1) Biomolecular engineering and control team led mechanism study of disease development and biomarker discovery.
2) Development of NT/BT/IT-based sensing and biomarker diagnostic platform led by biochemical diagnostic research team
3) Biomarker verification and treatment development through disease modeling led by the endocrine hormone function verification team and application intermediation to clinical samples
Omics is a powerful research tool for understanding disease mechanisms and drug actions in biochemical systems. The team focuses on finding steroid hormones, primary metabolites, lipids, genes and proteins as signaling molecules. Through integrated epidemiological studies of biological samples of disease models, we can uncover multiple biomarkers for reliable diagnostic tools in clinical practice.
Biomarker detection with comprehensive selectivity and sensitivity is an important aspect of disease testing. The NT/BT/IT-based biochemical diagnostic team focuses on developing simple equipment with continuous monitor ability through the development of sensing and diagnostic platforms using new nanomaterials and test kits to recognize multiple biomarkers based on field demand. Biomarker validation in terms of molecular diagnosis and treatment is a prerequisite for shedding light on the biochemical workings of diseases and drugs. Endocrine hormone function validation teams validate biomarkers and drug action targets through disease modeling, and create stable cell lines and genome-edited animal models for mechanism research.