Category Archives: 研究發表

Role of the stress-responsive two-component system CpxAR in regulating fimbriae expression in Klebsiella pneumoniae CG43

彭慧玲教授研究團隊發表研究成果於J Microbiol Immunol Infect.

連結網址:https://pubmed.ncbi.nlm.nih.gov/36898943/

Abstract

Background: CpxAR is a two-component system that allows bacteria to reorganize
envelope structures in response to extracellular stimuli. CpxAR negatively affects type 1 fimbriae expression in Klebsiella pneumoniae CG43, a hypervirulent strain. The involvement of CpxAR in the regulation of type 3 fimbriae expression was investigated.
Methods: cpxAR, cpxA, and cpxR gene-specific deletion mutants were generated. The deletion effects on the expression of type 1 and type 3 fimbriae were analyzed via measuring the promoter activity, mannose sensitive yeast agglutination activity, biofilm formation, and the production of the major pilins FimA and MrkA respectively. RNA sequencing analysis of CG43S3, DcpxAR, DcpxR and Dfur was employed to study the regulatory mechanism influencing the expression of type 3 fimbriae.
Results: Deletion of cpxAR increased type 1 and type 3 fimbrial expression. Comparative transcriptomic analysis showed that the expression of oxidative stress-responsive enzymes, type 1 and type 3 fimbriae, and iron acquisition and homeostasis control systems were differentially affected by cpxAR or cpxR deletion. Subsequent analysis revealed that the small RNA RyhB negatively affects the expression of type 3 fimbriae, while CpxAR positively controls ryhB expression. Finally, the site-directed mutation of the predicted interacting sequences of RyhB with the mRNA of MrkA attenuated the RyhB repression of type 3 fimbriae.

A genome-wide association study (GWAS) of the personality constructs in CPAI-2 in Taiwanese Hakka populations

林勇欣副教授研究團隊發表研究成果於PLOS ONE

連結網址:https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0281903

Abstract

Here in this study we adopted genome-wide association studies (GWAS) to investigate the genetic components of the personality constructs in the Chinese Personality Assessment Inventory 2 (CPAI-2) in Taiwanese Hakka populations, who are likely the descendants of a recent admixture between a group of Chinese immigrants with high emigration intention and a group of the Taiwanese aboriginal population generally without it. A total of 279 qualified participants were examined and genotyped by an Illumina array with 547,644 SNPs to perform the GWAS. Although our sample size is small and that unavoidably limits our statistical power (Type 2 error but not Type 1 error), we still found three genomic regions showing strong association with Enterprise, Diversity, and Logical vs. Affective Orientation, respectively. Multiple genes around the identified regions were reported to be nervous system related, which suggests that genetic variants underlying the certain personalities should indeed exist in the nearby areas. It is likely that the recent immigration and admixture history of the Taiwanese Hakka people created strong linkage disequilibrium between the emigration intention-related genetic variants and their neighboring genetic markers, so that we could identify them despite with only limited statistical power.

A lesion‑selective albumin‑CTLA4Ig as a safe and effective treatment for collagen‑induced arthritis

鄒協成副教授研究團隊發表研究成果於 Inflammation and Regeneration

連結網址:https://pubmed.ncbi.nlm.nih.gov/36797799/

Abstract

Background: CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG1 that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.

Methods: We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.

Results: Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.

Conclusions: Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

Adaptive neuroplasticity in the default mode network contributing to absence of central sensitization in primary dysmenorrhea

謝仁俊教授研究團隊發表研究成果於Frontiers in Neuroscience

連結網址:https://pubmed.ncbi.nlm.nih.gov/36845415/

Abstract

Introduction: Primary dysmenorrhea (PDM), the most prevalent gynecological problem among women of reproductive age, presents as a regular pattern of cyclic menstrual pain. The presence or absence of central sensitization (i.e., pain hypersensitivity) in cases of PDM is a contentious issue. Among Caucasians, the presence of dysmenorrhea is associated with pain hypersensitivity throughout the menstrual cycle, indicating pain amplification mediated by the central nervous system. We previously reported on the absence of central sensitization to thermal pain among Asian PDM females. In this study, functional magnetic resonance imaging was used to reveal mechanisms underlying pain processing with the aim of explaining the absence of central sensitization in this population.

Methods: Brain responses to noxious heat applied to the left inner forearm of 31 Asian PDM females and 32 controls during their menstrual and periovulatory phases were analyzed.

Results and discussion: Among PDM females experiencing acute menstrual pain, we observed a blunted evoked response and de-coupling of the default mode network from the noxious heat stimulus. The fact that a similar response was not observed in the non-painful periovulatory phase indicates an adaptive mechanism aimed at reducing the impact of menstrual pain on the brain with an inhibitory effect on central sensitization. Here we propose that adaptive pain responses in the default mode network may contribute to the absence of central sensitization among Asian PDM females. Variations in clinical manifestations among different PDM populations can be attributed to differences in central pain processing.

SWEET: a single-sample network inference method for deciphering individual features in disease

林峻宇助理教授研究團隊發表研究成果於Brief Bioinform.

連結網址:https://pubmed.ncbi.nlm.nih.gov/36719112/

Abstract

Recently, extracting inherent biological system information (e.g. cellular networks) from genome-wide expression profiles for developing personalized diagnostic and therapeutic strategies has become increasingly important. However, accurately constructing single-sample networks (SINs) to capture individual characteristics and heterogeneity in disease remains challenging. Here, we propose a sample-specific-weighted correlation network (SWEET) method to model SINs by integrating the genome-wide sample-to-sample correlation (i.e. sample weights) with the differential network between perturbed and aggregate networks. For a group of samples, the genome-wide sample weights can be assessed without prior knowledge of intrinsic subpopulations to address the network edge number bias caused by sample size differences. Compared with the state-of-the-art SIN inference methods, the SWEET SINs in 16 cancers more likely fit the scale-free property, display higher overlap with the human interactomes and perform better in identifying three types of cancer-related genes. Moreover, integrating SWEET SINs with a network proximity measure facilitates characterizing individual features and therapy in diseases, such as somatic mutation, mut-driver and essential genes. Biological experiments further validated two candidate repurposable drugs, albendazole for head and neck squamous cell carcinoma (HNSCC) and lung adenocarcinoma (LUAD) and encorafenib for HNSCC. By applying SWEET, we also identified two possible LUAD subtypes that exhibit distinct clinical features and molecular mechanisms. Overall, the SWEET method complements current SIN inference and analysis methods and presents a view of biological systems at the network level to offer numerous clues for further investigation and clinical translation in network medicine and precision medicine.

A flexible liposomal polymer complex as a platform of specific and regulable immune regulation For individual cancer immunotherapy

廖光文教授研究團隊發表研究成果於 J Exp Clin Cancer Res

連結網址:https://jeccr.biomedcentral.com/articles/10.1186/s13046-023-02601-8

Abstract

Background

The applicability and therapeutic efficacy of specific personalized immunotherapy for cancer patients is limited by the genetic diversity of the host or the tumor. Side-effects such as immune-related adverse events (IRAEs) derived from the administration of immunotherapy have also been observed. Therefore, regulatory immunotherapy is required for cancer patients and should be developed.

Methods

The cationic lipo-PEG-PEI complex (LPPC) can stably and irreplaceably adsorb various proteins on its surface without covalent linkage, and the bound proteins maintain their original functions. In this study, LPPC was developed as an immunoregulatory platform for personalized immunotherapy for tumors to address the barriers related to the heterogenetic characteristics of MHC molecules or tumor associated antigens (TAAs) in the patient population. Here, the immune-suppressive and highly metastatic melanoma, B16F10 cells were used to examine the effects of this platform. Adsorption of anti-CD3 antibodies, HLA-A2/peptide, or dendritic cells’ membrane proteins (MP) could flexibly provide pan-T-cell responses, specific Th1 responses, or specific Th1 and Th2 responses, depending on the host needs. Furthermore, with regulatory antibodies, the immuno-LPPC complex properly mediated immune responses by adsorbing positive or negative antibodies, such as anti-CD28 or anti-CTLA4 antibodies.

Results

The results clearly showed that treatment with LPPC/MP/CD28 complexes activated specific Th1 and Th2 responses, including cytokine release, CTL and prevented T-cell apoptosis. Moreover, LPPC/MP/CD28 complexes could eliminate metastatic B16F10 melanoma cells in the lung more efficiently than LPPC/MP. Interestingly, the melanoma resistance of mice treated with LPPC/MP/CD28 complexes would be reversed to susceptible after administration with LPPC/MP/CTLA4 complexes. NGS data revealed that LPPC/MP/CD28 complexes could enhance the gene expression of cytokine and chemokine pathways to strengthen immune activation than LPPC/MP, and that LPPC/MP/CTLA4 could abolish the LPPC/MP complex-mediated gene expression back to un-treatment.

Conclusions

Overall, we proved a convenient and flexible immunotherapy platform for developing personalized cancer therapy.

Hierarchical ensembles of FeCo metal-organic frameworks reinforced nickel foam as an impedimetric sensor for detection of IL-1RA in human samples

王雲銘教授研究團隊發表研究成果於 Chemical Engineering Journal

連結網址:https://www.sciencedirect.com/science/article/pii/S1385894723001754#f0040

Abstract

Early surveillance of oral cancer demands utmost concern owing to its alarming prevalence in the modern world. An efficient electrochemical impedimetric immunosensor is fabricated based on bimetallic amino-functionalized FeCo metal–organic frameworks uniformly grown on porous nickel foam solid supports (FeCo-MOF/NF) as a transducer for the detection of oral squamous cell carcinoma (OSCC). Herein, the interleukin-1 receptor antagonist (IL-1RA) antibody is used as a biorecognition element for the first time in the determination of oral cancer in real human blood samples using electrochemical impedance spectroscopy (EIS). Furthermore, the presence of specific functional groups ensures selectivity and rapid sensitivity against the target analyte IL-1RA when compared to the other biomarkers including interleukin-6 (IL-6), interleukin-8 (IL-8), CYFRA 21-1, and so on. The immunosensor shows a wide linear dynamic detection range of IL-1RA (10 fg/mL to 10 ng/mL) with a limit of detection (LOD) of 7.30 fg/mL in buffer and 7.22 fg/mL in serum conditions and a limit of quantification (LOQ) of 22.14 fg/mL in PBS and 21.88 fg/mL in serum. For a real-life demonstration, IL-1RA in human samples is detected by the immunosensor for the first time and compared with the gold standard method. The immunosensor also displays an excellent correlation with the standard detection of IL-1RA in human samples. Altogether, this work demonstrates that the electrochemical immunosensor has a high clinical significance by being a promising alternative to conventional approaches.

Nature-Inspired Surface Structures Design for Antimicrobial Applications

張家靖教授研究團隊發表研究成果於 Int. J. Mol. Sci.

連結網址:https://www.mdpi.com/1422-0067/24/2/1348

Abstract

Surface contamination by microorganisms such as viruses and bacteria may simultaneously aggravate the biofouling of surfaces and infection of wounds and promote cross-species transmission and the rapid evolution of microbes in emerging diseases. In addition, natural surface structures with unique anti-biofouling properties may be used as guide templates for the development of functional antimicrobial surfaces. Further, these structure-related antimicrobial surfaces can be categorized into microbicidal and anti-biofouling surfaces. This review introduces the recent advances

in the development of microbicidal and anti-biofouling surfaces inspired by natural structures and discusses the related antimicrobial mechanisms, surface topography design, material application, manufacturing techniques, and antimicrobial efficiencies.

Targeting EGFR and Monitoring Tumorigenesis of Human Lung Cancer Cells In Vitro and In Vivo Using Nanodiamond-Conjugated Specific EGFR Antibody

趙瑞益教授研究團隊發表研究成果於Pharmaceutics

連結網址:https://www.mdpi.com/1999-4923/15/1/111

Abstract

Abstract: Nanoprobes provide advantages for real-time monitoring of tumor markers and tumorigenesis during cancer progression and development. Epidermal growth factor receptor (EGFR) is a key protein that plays crucial roles for tumorigenesis and cancer therapy of lung cancers. Here, we show a carbon-based nanoprobe, nanodiamond (ND), which can be applied for targeting EGFR and monitoring tumorigenesis of human lung cancer cells in vitro and in vivo. The optimal fluorescent intensities of ND particles were observed in the human lung cancer cells and nude mice under in vivo imaging system. The fluorescence signal of ND particles can be real-time detected in the xenografted human lung tumor formation of nude mice. Moreover, the ND-conjugated specific EGFR antibody cetuximab (Cet) can track the location and distribution of EGFR proteins of lung cancer cells in vitro and in vivo. ND-Cet treatment increased cellular uptake ability of nanocomposites in the EGFR-expressed cells but not in the EGFR-negative lung cancer cells. Interestingly, single ND-Cet complex can be directly observed on the protein G bead by immunoprecipitation and confocal microscopy. Besides, the EGFR proteins were transported to lysosomes for degradation. Together, this study demonstrates that ND-conjugated Cet can apply for targeting EGFR and monitoring tumorigenesis during lung cancer progression and therapy.

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.

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