Category Archives: 研究發表

Sumoylation participates in the regulation of YB-1-mediated mismatch repair deficiency and alkylator tolerance

麥如村助理教授研究團隊發表研究成果於 Am J Cancer Res

連結網址:https://pubmed.ncbi.nlm.nih.gov/36628281/

Abstract

Numerous reports indicate that enhanced expression of Y-box binding protein-1 (YB-1) in tumor cells is strongly associated with tumorigenesis, aggressiveness, drug resistance, as well as poor prognosis in several types of cancers, and YB-1 is considered to be an oncogene. The molecular mechanism contributing to the regulation of the biological activities of YB-1 remains obscure. Sumoylation, a post-translational modification involving the covalent conjugation of small ubiquitin-like modifier (SUMO) proteins to a target protein, plays key roles in the modulation of protein functions. In this study, our results revealed that YB-1 is sumoylated and that Lys26 is a critical residue for YB-1 sumoylation. Moreover, YB-1 was found to directly interact with SUMO proteins, and disruption of the SUMO-interacting motif (SIM) of YB-1 not only interfered with this interaction but also diminished YB-1 sumoylation. The subcellular localization, protein stability, and transcriptional regulatory activity of YB-1 were not significantly affected by sumoylation. However, decreased sumoylation disrupted the interaction between YB-1 and PCNA as well as YB-1-mediated inhibition of the MutSα/PCNA interaction and MutSα mismatch binding activity, indicating a functional role of YB-1 sumoylation in inducing DNA mismatch repair (MMR) deficiency and spontaneous mutations. The MMR machinery also recognizes alkylator-modified DNA adducts to signal for cell death. We further demonstrated that YB-1 sumoylation is crucial for the inhibition of SN1-type alkylator MNNG-induced cytotoxicity, G2/M-phase arrest, apoptosis, and the MMR-dependent DNA damage response. Collectively, these results provide molecular explanations for the impact of YB-1 sumoylation on MMR deficiency and alkylator tolerance, which may provide insight for designing therapeutic strategies for malignancies and alkylator-resistant cancers associated with YB-1 overexpression.

Inhibition of IRAK1 Is an Effective Therapy for Autoimmune Hypophysitis in Mice

楊進木教授與鄒協成副教授研究團隊發表研究成果於International Journal of Molecular Sciences

連結網址:https://www.mdpi.com/1422-0067/23/23/14958

Abstract

Autoimmune hypophysitis (AH) is an autoimmune disease of the pituitary for which the pathogenesis is incompletely known. AH is often treated with corticosteroids; however, steroids may lead to considerable side effects. Using a mouse model of AH (experimental autoimmune hypophysitis, EAH), we show that interleukin-1 receptor-associated kinase 1 (IRAK1) is upregulated in the pituitaries of mice that developed EAH. We identified rosoxacin as a specific inhibitor for IRAK1 and found it could treat EAH. Rosoxacin treatment at an early stage (day 0–13) slightly reduced disease severity, whereas treatment at a later stage (day 14–27) significantly suppressed EAH. Further investigation indicated rosoxacin reduced production of autoantigen-specific antibodies. Rosoxacin downregulated production of cytokines and chemokines that may dampen T cell differentiation or recruitment to the pituitary. Finally, rosoxacin downregulated class II major histocompatibility complex expression on antigen-presenting cells that may lead to impaired activation of autoantigen-specific T cells. These data suggest that IRAK1 may play a pathogenic role in AH and that rosoxacin may be an effective drug for AH and other inflammatory diseases involving IRAK1 dysregulation.

Methotrexate inhibition of SARS-CoV-2 entry, infection and inflammation revealed by bioinformatics approach and a hamster model

楊進木教授研究團隊發表研究成果於Front. Immunol.

連結網址:https://www.frontiersin.org/articles/10.3389/fimmu.2022.1080897/full

Abstract

Background: Drug repurposing is a fast and effective way to develop drugs for

an emerging disease such as COVID-19. The main challenges of effective drug

repurposing are the discoveries of the right therapeutic targets and the right

drugs for combating the disease.

Methods: Here, we present a systematic repurposing approach, combining

Homopharma and hierarchal systems biology networks (HiSBiN), to predict 327

therapeutic targets and 21,233 drug-target interactions of 1,592 FDA drugs for

COVID-19. Among these multi-target drugs, eight candidates (along with

pimozide and valsartan) were tested and methotrexate was identified to

affect 14 therapeutic targets suppressing SARS-CoV-2 entry, viral replication, and COVID-19 pathologies. Through the use of in vitro (EC50 = 0.4 mM) and in

vivo models, we show that methotrexate is able to inhibit COVID-19 via

multiple mechanisms.

Results: Our in vitro studies illustrate that methotrexate can suppress SARSCoV-

2 entry and replication by targeting furin and DHFR of the host,

respectively. Additionally, methotrexate inhibits all four SARS-CoV-2 variants

of concern. In a Syrian hamster model for COVID-19, methotrexate reduced

virus replication, inflammation in the infected lungs. By analysis of

transcriptomic analysis of collected samples from hamster lung, we

uncovered that neutrophil infiltration and the pathways of innate immune

response, adaptive immune response and thrombosis are modulated in the

treated animals.

Conclusions: We demonstrate that this systematic repurposing approach is

potentially useful to identify pharmaceutical targets, multi-target drugs and

regulated pathways for a complex disease. Our findings indicate that

methotrexate is established as a promising drug against SARS-CoV-2 variants

and can be used to treat lung damage and inflammation in COVID-19,

warranting future evaluation in clinical trials.

Structure-guided product determination of the bacterial type II diterpene synthase Tpn2

張晉源助理教授研究團隊發表研究成果於Communications Chemistry

連結網址:https://www.nature.com/articles/s42004-022-00765-6

Abstract

A grand challenge in terpene synthase (TS) enzymology is the ability to predict function from protein sequence. Given the limited number of characterized bacterial TSs and significant sequence diversities between them and their eukaryotic counterparts, this is currently impossible. To contribute towards understanding the sequence-structure-function relationships of type II bacterial TSs, we determined the structure of the terpentedienyl diphosphate synthase Tpn2 from Kitasatospora sp. CB02891 by X-ray crystallography and made structureguided mutants to probe its mechanism. Substitution of a glycine into a basic residue changed the product preference from the clerodane skeleton to a syn-labdane skeleton, resulting in the first syn-labdane identified from a bacterial TS. Understanding how a single residue can dictate the cyclization pattern in Tpn2, along with detailed bioinformatics analysis of bacterial type II TSs, sets the stage for the investigation of the functional scope of bacterial type II TSs and the discovery of novel bacterial terpenoids.

Circular Polarization Luminescence of Groove Anchor Driving Optically Active Poly(methyl methacrylate) Stereocomplexes

李明家副教授研究團隊發表研究成果於ACS Macro Lett

連結網址:https://pubmed.ncbi.nlm.nih.gov/36326692/

Abstract

This paper presents a facile method for fabricating a thin-film sample with a high asymmetry value of induced circularly polarized luminescence (iCPL) (|glum| = 2.0 × 10-3). The method involves mixing stereoregular poly(methyl methacrylate) (PMMA) and chiral chromophore (2,2,2-trifluoro-1-(9-anthryl)ethanol (TFAE)) to form a complex with a dynamic helical conformation of poly(methyl methacrylate) (PMMA) associated with TFAE via hydrogen bonding. This dynamic helical conformation can be stabilized by the stereocomplexation of a pair of stereoregular PMMA, where the TFAE is sandwiched between a double-helix isotactic PMMA and single-helix syndiotactic PMMA, resulting in a preferential one-handed helical conformation with a high value of iCPL from self-assembly.

Engineering a High-Affinity Anti-Methoxy Poly(ethylene glycol) (mPEG) Antibody for Sensitive Immunosensing of mPEGylated Therapeutics and mPEG Molecules

蘇昱誠助理教授研究團隊發表研究成果於Bioconjug Chem.

連結網址:https://pubmed.ncbi.nlm.nih.gov/36320124/

Abstract

Sensitive quantification of methoxy poly(ethylene glycol) (mPEG)-conjugated therapeutics for pharmacokinetic determination is critical for mPEGylated drug development. However, sensitive measurement of low-molecular-weight (lmw) mPEG compounds remains challenging due to epitope competition between backbone-specific anti-PEG antibodies. Here, we engineered a high-affinity methoxy-specific anti-mPEG antibody for sensitive quantification of free mPEG molecules and mPEGylated therapeutics. The affinity-enhanced h15-2Y antibody variant shows a 10.3-fold increase in mPEG-binding activity compared to parental h15-2b. h15-2Y-based sandwich ELISA can effectively quantify lmw mPEG5K and high-molecular-weight (hmw) mPEG20K at concentrations as low as 3.4 and 5.1 ng mL-1, respectively. Moreover, lmw mPEG compounds (560, 750, 1000, and 2000 Da) can be efficiently quantified via h15-2Y-based competitive ELISA with detection limits at nanomolar levels. This study provides a promising approach for application in the quantitative analysis of the various sizes of mPEG molecules to accelerate the timeline of mPEG-conjugated drug development.

Co-inhibition of Aurora A and Haspin kinases enhances survivin blockage and p53 induction for mitotic catastrophe and apoptosis in human colorectal cancer

趙瑞益教授研究團隊發表研究成果於 Biochemical Pharmacology

連結網址:https://www.sciencedirect.com/science/article/pii/S0006295222003835

Abstract

Abstract

Colorectal cancer (CRC) is a leading cause and mortality worldwide. Aurora A and haspin kinases act pivotal roles in mitotic progression. However, the blockage of Aurora A and Haspin for CRC therapy is still unclear. Here we show that the Haspin and p-H3T3 protein levels were highly expressed in CRC tumor tissues of clinical patients. Overexpression of Haspin increased the protein levels of p-H3T3 and survivin in human CRC cells; conversely, the protein levels of p-H3T3 and survivin were decreased by the Haspin gene knockdown. Moreover, the gene knockdown of Aurora A induced abnormal chromosome segregation, mitotic catastrophe, and cell growth inhibition. Combined targeted by co-treatment of CHR6494, a Haspin inhibitor, and MLN8237, an Aurora A inhibitor, enhanced apoptosis and CRC tumor inhibition. MLN8237 and CHR6494 induced abnormal chromosome segregation and mitotic catastrophe. Meanwhile, MLN8237 and CHR6494 inhibited survivin protein levels but conversely induced p53 protein expression. Ectopic survivin expression by transfection with a survivin-expressed vector resisted the cell death in the MLN8237- and CHR6494-treated cells. In contrast, the existence of functional p53 increased the apoptotic levels by treatment with MLN8237 and CHR6494. Co-treatment of CHR6494 and MLN8237 enhanced the blockage of human CRC xenograft tumors in nude mice. Taken together, co-inhibition of Aurora A and Haspin enhances survivin inhibition, p53 pathway induction, mitotic catastrophe, apoptosis and tumor inhibition that may provide a potential strategy for CRC therapy.

CRISPRi-enhanced direct photosynthetic conversion of carbon dioxide to succinic acid by metabolically engineered cyanobacteria

蘭宜錚副教授研究團隊發表研究成果於 Bioresource Technology

連結網址:https://pubmed.ncbi.nlm.nih.gov/36252759/

Abstract

Engineering photoautotrophic microorganisms to directly convert carbon dioxide into platform chemicals is an attractive approach for chemical sustainability and carbon mitigation. Here, an engineered cyanobacterium Synechococcus elongatus PCC 7942 was developed to produce succinic acid directly from ambient carbon dioxide. Inhibition of succinate dehydrogenase and glycogen synthase by CRIPSR interference increased carbon flux towards succinic acid. Dual inhibition of these two genes led to an 82% increase in titer. The resulting strain produced 4.8 g/L of succinic acid in a 28-days cultivation. However, cells after the 28-days cultivation became non-viable and cannot continue production. This issue was addressed by re-inoculation with fresh cells into the production medium. This strategy enabled continuous succinic acid accumulation, reaching a final titer of 8.9 g/L. This study provides a sustainable route to succinic acid directly from carbon dioxide and a potential method to overcome the low titer limitation of cyanobacterial-based bioproduction for practical applications.

MOCHI: a comprehensive cross-platform tool for amplicon-based microbiota analysis

陳亭妏副教授研究團隊發表研究成果於 Bioinformatics

連結網址:https://academic.oup.com/bioinformatics/article/38/18/4286/6649618

Abstract

Motivation: Microbiota analyses have important implications for health and science. These analyses make use of 16S/18S rRNA gene sequencing to identify taxa and predict species diversity. However, most available tools for analyzing microbiota data require adept programming skills and in-depth statistical knowledge for proper implementation. While long-read amplicon sequencing can lead to more accurate taxa predictions and is quickly becoming more common, practitioners have no easily accessible tools with which to perform their analyses.

Results: We present MOCHI, a GUI tool for microbiota amplicon sequencing analysis. MOCHI preprocesses sequences, assigns taxonomy, identifies different abundant species and predicts species diversity and function. It takes either taxonomic count table or FASTQ of partial 16S/18S rRNA or full-length 16S rRNA gene as input. It performs analyses in real time and visualizes data in both tabular and graphical formats.

Availability and implementation: MOCHI can be installed to run locally or accessed as a web tool at https://mochi.life.nctu.edu.tw

Multimodal single-cell analysis provides novel insights on ankylosing spondylitis in females

柯泰名助理教授研究團隊發表研究成果於 Clin Transl Med.

連結網址:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9547115/

Summary

Ankylosing spondylitis (AS) is a chronic rheumatic disease that causes disability and severe impairment in the quality of life, especially in females. However, almost nothing is known about how large heterogenous circulating immune cells are involved in developing AS. Here we used droplet-based single-cell sequencing for multi-omic profiling of PBMCs obtained from female patients and sex-matched healthy individuals and performed multimodal single-cell analyses including single-cell-level unbiased transcriptome, surface protein expression, pseudotemporal trajectory analysis, cell-cell interaction analysis, and T-cell receptor repertoire. By applying multiple filtering strategies, we selected common single-cell blood features across the patients to reveal a unique T-cell state wherein GIMAP7 was up-regulated and NFKBIA was down-regulated. Furthermore, we identified a panel of cell-surface markers and dominant T-cell clonotypes on this unique T-cell subset (NFKBIA- GIMAP7+). We identified a unique VEGI signalling pathway between the T-cells and NK cells that uncovered potential triggers for developing exclusive T-cell states in female patients with AS. This finding could be valuable for developing innovative therapies that selectively target the aberrant immune response in female patients with AS.

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