Biology subjects

Hsu, C.-C.

Publications and source records attributed to Hsu, C.-C..

22 records · Page 2Linked to original sources

bioRxiv2019

High Spatial Resolution Ambient Ionization Mass Spectrometry Imaging Using Microscopy Image Fusion

Mass spectrometry imaging (MSI) using ambient ionization technique enables a direct chemical investigation of biological samples with minimal sample pretreatment. However, detailed morphological information of the sample is often lost due to its limited spatial resolution. In this study, predictive high-resolution molecular imaging was produced by the fusion of ambient ionization MSI with optical microscopy of routine hematoxylin and eosin (H&E) staining produces. Specifically, desorption electrospray ionization (DESI) and nanospray desorption electrospray ionization (nanoDESI) mass spectrometry are employed to visualize lipid and protein species on mice tissue sections. The resulting molecular distributions obtained by ambient ionization MSI-microscopy fusion are verified with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MSI and immunohistochemistry (IHC) staining. Label-free molecular imaging with 5-m spatial resolution can be acquired using DESI and nanoDESI, whereas the typical spatial resolution of ambient ionization MSI is ~100 m. In this regard, sharpened molecular histology of tissue sections is achieved, providing complementary references to the pathology. Such a multimodality integration enables the discovery of potential tumor biomarkers. After image fusion, more than a dozen of potential biomarkers that could be used to determine the tumor margins on a metastatic mouse lung tissue section and Luminal B breast tumor tissue section are identified.

bioinformatics↗

bioRxiv2019

Structural Lipidomics and Molecular Imaging of C=C Positional Isomers Enabled by mCPBA Epoxidation with Tandem Mass Spectrometry

Cellular lipidome is highly regulated through lipogenesis, rendering diverse double-bond positional isomers (C=C isomer) of a given unsaturated lipid species. In recent years, there are increasing reports indicating the physiological roles of C=C isomer compositions associated with diseases, while the biochemistry has not been fully understood due to the challenge in characterizing lipid isomers inherent to conventional mass spectrometry-based lipidomics. To address this challenge, we reported a universal, user-friendly, derivatization-based strategy, MELDI (mCPBA Epoxidation for Lipid Double-bond Identification), which enables both large-scale identification and spatial mapping of biological C=C isomers using commercial mass spectrometers without any instrument modification. With the developed liquid-chromatography mass spectrometry (LC-MS) lipidomics workflow, we elucidated more than 100 isomers among mono- and poly-unsaturated fatty acids and glycerophospholipids in both human serum, where novel isomers of low abundance were unambiguously quantified for the first time. The capability of MELDI-LC-MS in lipidome analysis was further demonstrated using the differentiated 3T3-L1 adipocytes, providing an insight into the cellular lipid reprogramming upon stearoyl-coenzyme A desaturase 1 (SCD1) inhibition. Finally, we highlighted the versatility of MELDI coupled with mass spectrometry imaging to spatially resolve cancer-associated alteration of lipid isomers in a metastatic mouse tissue section. Our results suggested that MELDI will contribute to current lipidomics pipelines with a deeper level of structural information, allowing us to investigate underlying lipid biochemistry.

biochemistry↗

bioRxiv2019

Application of TurboID-mediated proximity labeling for mapping a GSK3 kinase signaling network in Arabidopsis

Transient protein-protein interactions (PPIs), such as those between posttranslational modifying enzymes and their substrates, play key roles in cellular regulation, but are difficult to identify. Here we demonstrate the application of enzyme-catalyzed proximity labeling (PL), using the engineered promiscuous biotin ligase TurboID, as a sensitive method for characterizing PPIs in signaling networks. We show that TurboID fused with the GSK3-like kinase BIN2 or a PP2A phosphatase biotinylates their known substrate, the BZR1 transcription factor, with high specificity and efficiency. We optimized the protocol of biotin labeling and affinity purification in transgenic Arabidopsis expressing a BIN2-TurboID fusion protein. Subsequent quantitative mass spectrometry (MS) analysis identified about three hundred proteins biotinylated by BIN2-TurboID more efficiently than the YFP-TurboID control. These include a significant subset of previously proven BIN2 interactors and a large number of new BIN2-proximal proteins that uncover a broad BIN2 signaling network. Our study illustrates that PL-MS using TurboID is a powerful tool for mapping signaling networks, and reveals broad roles of BIN2 kinase in cellular signaling and regulation in plants.\n\nImpact StatementTurboID-mediated proximity labeling is a powerful tool for protein interactomics in plants.

plant biology↗

bioRxiv2018

Chronic pain with use of analgesics and mortality in the home healthcare elderly: a nationwide population-based study

BackgroundChronic pain may cause increased complications and all-cause mortality. However, nationwide data on elderly patients receiving home healthcare (HHC) remain unknown. Therefore, we conducted this study to address this issue.\n\nMethodsWe identified elderly individuals ([≥] 65 years) with chronic pain receiving HCC between 2002 and 2013 in the Taiwan National Health Insurance Research Database. The comparisons of the causes of chronic pain, comorbidities, follow-up mortality, and the use of analgesics between two sexes and among three age subgroups were performed.\n\nResultsA total of 1435 participants were identified, with a mean age of 77.8 {+/-} 7.1 years and male percentage of 46.7%. The prevalence of chronic pain was 5.8%. Chronic pain was most prevalent in the 75-84 years age group (46.5%). Malignancy was the most common cause of chronic pain (94.2%), followed by peripheral vascular diseases (6.0%), osteoarthritis (4.3%), pressure ulcer (3.9%), spine diseases (3.1%), osteoporosis (1.3%), and headache (1.3%). The follow-up mortality was 32.8% within 6 month, 64.1% within 1 year, 79.9% within 2 years, and 84.3% within 3 years without difference in two sexes and age subgroups. Acetaminophen was found to be the most common analgesics, followed by non-steroidal anti-inflammatory drugs and opioids. Morphine was the most commonly used opioid.\n\nConclusionsThis study delineates the causes of chronic pain, use of analgesics, and follow-up mortality in the HHC elderly, clarifying the relationship between chronic pain and the HCC elderly. This will facilitate the further investigation of this issue in the future.

epidemiology↗