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  • 1
    In: Biomolecules, MDPI AG, Vol. 9, No. 12 ( 2019-12-12), p. 864-
    Abstract: Antizyme (AZ) is a protein that negatively regulates ornithine decarboxylase (ODC). AZ achieves this inhibition by binding to ODC to produce AZ-ODC heterodimers, abolishing enzyme activity and targeting ODC for degradation by the 26S proteasome. In this study, we focused on the biomolecular interactions between the C-terminal domain of AZ (AZ95–228) and ODC to identify the functional elements of AZ that are essential for binding, inhibiting and degrading ODC, and we also identified the crucial factors governing the differential binding and inhibition ability of AZ isoforms toward ODC. Based on the ODC inhibition and AZ-ODC binding studies, we demonstrated that amino acid residues reside within the α1 helix, β5 and β6 strands, and connecting loop between β6 and α2 (residues 142–178), which is the posterior part of AZ95–228, play crucial roles in ODC binding and inhibition. We also identified the essential elements determining the ODC-degradative activity of AZ; amino acid residues within the anterior part of AZ95–228 (residues 120–145) play crucial roles in AZ-mediated ODC degradation. Finally, we identified the crucial factors that govern the differential binding and inhibition of AZ isoforms toward ODC. Mutagenesis studies of AZ1 and AZ3 and their binding and inhibition revealed that the divergence of amino acid residues 124, 150, 166, 171, and 179 results in the differential abilities of AZ1 and AZ3 in the binding and inhibition of ODC.
    Type of Medium: Online Resource
    ISSN: 2218-273X
    Language: English
    Publisher: MDPI AG
    Publication Date: 2019
    detail.hit.zdb_id: 2701262-1
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  • 2
    In: Nutrients, MDPI AG, Vol. 12, No. 12 ( 2020-12-17), p. 3867-
    Abstract: Background: Human ornithine decarboxylase (ODC) is a well-known oncogene, and the discovery of ODC enzyme inhibitors is a beneficial strategy for cancer therapy and prevention. Methods: We examined the inhibitory effects of a variety of flavone and flavonol derivatives on ODC enzymatic activity, and performed in silico molecular docking of baicalein, 7,8-dihydroxyflavone and myricetin to the whole dimer of human ODC to investigate the possible binding site of these compounds on ODC. We also examined the cytotoxic effects of these compounds with cell-based studies. Results: Baicalein, 7,8-dihydroxyflavone and myricetin exhibited significant ODC suppression activity with IC50 values of 0.88 µM, 2.54 µM, and 7.3 µM, respectively, which were much lower than that of the active-site irreversible inhibitor α-DL-difluoromethylornithine (IC50, the half maximal inhibitory concentration, of approximately 100 µM). Kinetic studies and molecular docking simulations suggested that baicalein, and 7,8-dihydroxyflavone act as noncompetitive inhibitors that are hydrogen-bonded to the region near the active site pocket in the dimer interface of the enzyme. Baicalein and myricetin suppress cell growth and induce cellular apoptosis, and both of these compounds suppress the ODC-evoked anti-apoptosis of cells. Conclusions: Therefore, we suggest that the flavone or flavonol derivatives baicalein, 7,8-dihydroxyflavone, and myricetin are potent chemopreventive and chemotherapeutic agents that target ODC.
    Type of Medium: Online Resource
    ISSN: 2072-6643
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2518386-2
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  • 3
    In: Cells, MDPI AG, Vol. 9, No. 6 ( 2020-05-27), p. 1339-
    Abstract: Amyloid β (Aβ) is a peptide fragment of the amyloid precursor protein that triggers the progression of Alzheimer’s Disease (AD). It is believed that Aβ contributes to neurodegeneration in several ways, including mitochondria dysfunction, oxidative stress and brain insulin resistance. Therefore, protecting neurons from Aβ-induced neurotoxicity is an effective strategy for attenuating AD pathogenesis. Recently, applications of stem cell-based therapies have demonstrated the ability to reduce the progression and outcome of neurodegenerative diseases. Particularly, Nanog is recognized as a stem cell-related pluripotency factor that enhances self-renewing capacities and helps reduce the senescent phenotypes of aged neuronal cells. However, whether the upregulation of Nanog can be an effective approach to alleviate Aβ-induced neurotoxicity and senescence is not yet understood. In the present study, we transiently overexpressed Nanog—both in vitro and in vivo—and investigated the protective effects and underlying mechanisms against Aβ. We found that overexpression of Nanog is responsible for attenuating Aβ-triggered neuronal insulin resistance, which restores cell survival through reducing intracellular mitochondrial superoxide accumulation and cellular senescence. In addition, upregulation of Nanog expression appears to increase secretion of neurotrophic factors through activation of the Nrf2 antioxidant defense pathway. Furthermore, improvement of memory and learning were also observed in rat model of Aβ neurotoxicity mediated by upregulation of Nanog in the brain. Taken together, our study suggests a potential role for Nanog in attenuating the neurotoxic effects of Aβ, which in turn, suggests that strategies to enhance Nanog expression may be used as a novel intervention for reducing Aβ neurotoxicity in the AD brain.
    Type of Medium: Online Resource
    ISSN: 2073-4409
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2661518-6
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  • 4
    In: Symmetry, MDPI AG, Vol. 12, No. 2 ( 2020-02-02), p. 213-
    Abstract: From traditional face-to-face courses, asynchronous distance learning, synchronous live learning, to even blended learning approaches, the learning approach can be more learner-centralized, enabling students to learn anytime and anywhere. In this study, we applied educational data mining to explore the learning behaviors in data generated by students in a blended learning course. The experimental data were collected from two classes of Python programming related courses for first-year students in a university in northern Taiwan. During the semester, high-risk learners could be predicted accurately by data generated from the blended educational environment. The f1-score of the random forest model was 0.83, which was higher than the f1-score of logistic regression and decision tree. The model built in this study could be extrapolated to other courses to predict students’ learning performance, where the F1-score was 0.77. Furthermore, we used machine learning and symmetry-based learning algorithms to explore learning behaviors. By using the hierarchical clustering heat map, this study could define the students’ learning patterns including the positive interactive group, stable learning group, positive teaching material group, and negative learning group. These groups also corresponded with the student conscious questionnaire. With the results of this research, teachers can use the mid-term forecasting system to find high-risk groups during the semester and remedy their learning behaviors in the future.
    Type of Medium: Online Resource
    ISSN: 2073-8994
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2518382-5
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  • 5
    In: Journal of Personalized Medicine, MDPI AG, Vol. 12, No. 2 ( 2022-01-19), p. 132-
    Abstract: Aims: Pressure injury is a gradually increasing disease in the aging society. The reconstruction of a pressure ulcer requires a patient and surgical technique. The patients were exposed to the radiation risk under other ways of detection of perforators such as computed tomographic angiography and magnetic resonance angiography. Here, we compared two radiation-free methods of a superior gluteal artery perforator (SGAP), flap harvesting and anchoring. One is the traditional method of detecting only handheld acoustic Doppler sonography (ADS) (Group 1). The other involves the assistance of intraoperative indocyanine green fluorescent near-infrared angiography (ICGFA) and handheld ADS (Group 2). Materials and Methods: This is a single-center, retrospective, observational study that included patients with sacral pressure injury grades III and IV, who had undergone reconstructive surgery with an SGAP flap between January 2019 and January 2021. Two detection methods were used intraoperatively. The main outcome measures included the operative time, estimated blood loss, major perforator detection numbers, wound condition, and incidence of complications. Results: Sixteen patients underwent an SGAP flap reconstruction. All patients were diagnosed with grade III to IV sacral pressure injury after a series of examinations. Group 1 included 8 patients with a mean operative time of 91 min, and the mean estimated blood loss was 50 mL. The mean number of perforators was 4. Postoperative complications included one wound infection in one case and wound edge dehiscence in one case. No mortality was associated with this procedure. The mean total hospital stay was 16 days. Group 2 included 8 patients with a mean operative time of 107.5 min, and the mean estimated blood loss was 50 mL. The mean number of perforators was 5. Postoperative complications included one wound infection. No mortality was associated with this procedure. The mean total hospital stay was 13 days. Conclusions: The combination of detection of the SGAP by ICGFA and handheld ADS for the reconstruction of a sacral pressure injury provides a more accurate method and provides the advantage of being radiation-free.
    Type of Medium: Online Resource
    ISSN: 2075-4426
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662248-8
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  • 6
    Online Resource
    Online Resource
    MDPI AG ; 2015
    In:  International Journal of Molecular Sciences Vol. 16, No. 12 ( 2015-05-07), p. 10426-10442
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 16, No. 12 ( 2015-05-07), p. 10426-10442
    Type of Medium: Online Resource
    ISSN: 1422-0067
    Language: English
    Publisher: MDPI AG
    Publication Date: 2015
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 7
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 22, No. 16 ( 2021-08-05), p. 8424-
    Abstract: Huntington’s disease (HD) is an autosomal-dominant brain disorder caused by mutant huntingtin (mHtt). Although the detailed mechanisms remain unclear, the mutational expansion of polyglutamine in mHtt is proposed to induce protein aggregates and neuronal toxicity. Previous studies have shown that the decreased insulin sensitivity is closely related to mHtt-associated impairments in HD patients. However, how mHtt interferes with insulin signaling in neurons is still unknown. In the present study, we used a HD cell model to demonstrate that the miR-302 cluster, an embryonic stem cell-specific polycistronic miRNA, is significantly downregulated in mHtt-Q74-overexpressing neuronal cells. On the contrary, restoration of miR-302 cluster was shown to attenuate mHtt-induced cytotoxicity by improving insulin sensitivity, leading to a reduction of mHtt aggregates through the enhancement of autophagy. In addition, miR-302 also promoted mitophagy and stimulated Sirt1/AMPK-PGC1α pathway thereby preserving mitochondrial function. Taken together, these results highlight the potential role of miR-302 cluster in neuronal cells, and provide a novel mechanism for mHtt-impaired insulin signaling in the pathogenesis of HD.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 8
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 22, No. 4 ( 2021-02-09), p. 1720-
    Abstract: Long non-coding RNA steroid receptor RNA activators (LncRNA SRAs) are implicated in the β-cell destruction of Type 1 diabetes mellitus (T1D), but functional association remains poorly understood. Here, we aimed to verify the role of LncRNA SRA regulation in β-cells. LncRNA SRAs were highly expressed in plasma samples and peripheral blood mononuclear cells (PBMCs) from T1D patients. LncRNA SRA was strongly upregulated by high-glucose treatment. LncRNA SRA acts as a microRNA (miR)-146b sponge through direct sequence–structure interactions. Silencing of lncRNA SRA increased the functional genes of Tregs, resulting in metabolic reprogramming, such as decreased lactate levels, repressed lactate dehydrogenase A (LDHA)/phosphorylated LDHA (pLDHA at Tyr10) expression, decreased reactive oxygen species (ROS) production, increased ATP production, and finally, decreased β-cell apoptosis in vitro. There was a positive association between lactate level and hemoglobin A1c (HbA1c) level in the plasma from patients with T1D. Recombinant human interleukin (IL)-2 treatment repressed lncRNA SRA expression and activity in β-cells. Higher levels of lncRNA-SRA/lactate in the plasma are associated with poor regulation in T1D patients. LncRNA SRA contributed to T1D pathogenesis through the inhibition of miR-146b in β-cells, with activating signaling transduction of interleukin-1 receptor-associated kinase 1 (IRAK1)/LDHA/pLDHA. Taken together, LncRNA SRA plays a critical role in the function of β-cells.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 9
    In: Cancers, MDPI AG, Vol. 15, No. 16 ( 2023-08-17), p. 4150-
    Abstract: Background: Diffuse large B-cell lymphoma (DLBCL) is a malignant lymphoid tumor disease that is characterized by heterogeneity, but current treatment does not benefit all patients, which highlights the need to identify oncogenic genes and appropriate drugs. G9a is a histone methyltransferase that catalyzes histone H3 lysine 9 (H3K9) methylation to regulate gene function and expression in various cancers. Methods: TCGA and GTEx data were analyzed using the GEPIA2 platform. Cell viability under drug treatment was assessed using Alamar Blue reagent; the interaction between G9a and niclosamide was assessed using molecular docking analysis; mRNA and protein expression were quantified in DLBCL cell lines. Finally, G9a expression was quantified in 39 DLBCL patient samples. Results: The TCGA database analysis revealed higher G9a mRNA expression in DLBCL compared to normal tissues. Niclosamide inhibited DLBCL cell line proliferation in a time- and dose-dependent manner, reducing G9a expression and increasing p62, BECN1, and LC3 gene expression by autophagy pathway regulation. There was a correlation between G9a expression in DLBCL samples and clinical data, showing that advanced cancer stages exhibited a higher proportion of G9a-expressing cells. Conclusion: G9a overexpression is associated with tumor progression in DLBCL. Niclosamide effectively inhibits DLBCL growth by reducing G9a expression via the cellular autophagy pathway; therefore, G9a is a potential molecular target for the development of therapeutic strategies for DLBCL.
    Type of Medium: Online Resource
    ISSN: 2072-6694
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2527080-1
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  • 10
    In: Life, MDPI AG, Vol. 12, No. 4 ( 2022-04-10), p. 566-
    Abstract: Brainstem tumors are heterogenous and cancerous glioma tumors arising from the midbrain, pons, and the medulla that are relatively common in children, accounting for 10% to 20% of all pediatric brain tumors. However, the prognosis of aggressive brainstem gliomas remains extremely poor despite aggressive treatment with chemotherapy and radiotherapy. That means there are many life-threatening patients who have exhausted all available treatment options and are beginning to face end-of-life stage. Therefore, the unique properties of highly selective heavy particle irradiation with boron neutron capture therapy (BNCT) may be well suited to prolong the lives of patients with end-stage brainstem gliomas. Herein, we report a case series of life-threatening patients with end-stage brainstem glioma who eligible for Emergency and Compassionate Use, in whom we performed a scheduled two fractions of salvage BNCT strategy with low treatment dosage each time. No patients experienced acute or late adverse events related to BNCT. There were 3 patients who relapsed after two fractionated BNCT treatment, characterized by younger age, lower T/N ratio, and receiving lower treatment dose. Therefore, two fractionated low-dose BNCT may be a promising treatment for end-stage brainstem tumors. For younger patients with low T/N ratios, more fractionated low-dose BNCT should be considered.
    Type of Medium: Online Resource
    ISSN: 2075-1729
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2662250-6
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