production-arbuscular-mycorrhizal-am-fungal-inoculum-phenotypic

Production of Arbuscular Mycorrhizal (AM) Fungal Inoculum and Phenotypic Evaluation of Rice and AM Symbiosis Under Saline Conditions

Rice (Oryza sativa L.) is a vital food crop for more than half of the global population. However, its growth is severely impacted by saline soils, which ...

National Taiwan University

This study aimed to examine the trends and factors associated with antipsychotic prescriptions for elderly outpatients with dementia in Taiwan from 2005 to 2013. We assessed the annual prescription patterns of antipsychotic medications among elderly patients attending outpatient visits for dementia between 2005 and 2013 using the National Health Insurance Research Database in Taiwan. We also carried out logistic regression analyses to test the trends and associated factors. We found that any antipsychotic prescriptions for elderly patients making visits for dementia increased slightly, from 25.5 to 26.5%, over the 9-year period. From 2005 to 2013, prescriptions for first-generation antipsychotics only decreased from 7.8 to 3.3%, whereas second-generation antipsychotic prescriptions only increased from 17.0 to 22.2%. Elderly dementia patients who were female, older, concomitantly using other psychotropic drugs (antidepressants, benzodiazepines, and Z-drugs), and treated by psychiatrists and at regional/local hospitals were prescribed significantly more antipsychotics, whereas patients with comorbid hypertension, hyperlipidemia, diabetes, and stroke used antipsychotics significantly less. Although physicians seemed to avoid prescribing antipsychotics for elderly outpatients with dementia and certain comorbid physical disorders, second-generation antipsychotic use increased during the study period. Physicians should balance the benefits and risks of antipsychotic use to ensure the safety of dementia patients.

Trends and factors associated with antipsychotic use among elderly patients with dementia in Taiwan from 2005 to 2013: a population-based study.

 pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA have been evolved to generate genetically encoded noncanonical amino acids (ncAAs). Use of tryptophan (Trp) analogues with pyrrole ring modification for their spatial and polarity tuning in enzyme activity and substrate specificity is still limited. Herein, we report the application of an evolved PylRS, FOWRS2, for efficient incorporation of five Trp analogues into the deubiquitinase USP30 to decipher the role of W475 for diubiquitin selectivity. Structures of the five FOWRS-C/Trp analogue complexes at 1.7-2.5 Å resolution showed multiple ncAA binding modes. The W475 near the USP30 active site was replaced with Trp analogues, and the effect on the activity as well as the selectivity toward diubiquitin linkage types was examined. It was found that the Trp analogue with a formyl group attached to the nitrogen atom of the indole ring led to an improved activity of USP30 likely due to enhanced polar interactions and that another Trp analogue, 3-benzothienyl-l-alanine, induced a unique K6-specificity. Collectively, genetically encoded noncanonical Trp analogues by evolved PylRS· pair unravel the spatial role of USP30-W475 in its diubiquitin selectivity.

Probing the Active Site of Deubiquitinase USP30 with Noncanonical Tryptophan Analogues.

Ubiquitination and SUMOylation of protein are crucial for various biological responses. The recent unraveling of cross-talk between SUMO and ubiquitin (Ub) has shown the pressing needs to develop the platform for the synthesis of Ub tagged SUMO2 dimers to decipher its biological functions. Still, the platforms for facile synthesis of dimers under native condition are less explored and remain major challenges. Here, we have developed the platform that can expeditiously synthesize all eight Ub tagged SUMO2 and SUMOylated proteins under native condition. Expanding genetic code (EGC) method was employed to incorporate Se-alkylselenocysteine at lysine positions. Oxidative selenoxide elimination generates the electrophilic center, dehydroalanine, which upon Michael addition with C-terminal modified ubiquitin, a nucleophile, yield Ub tagged SUMO2. The dimers were further interrogated with USP7, a SUMO2 deubiquitinase, which is involved in DNA repair, to understand specificity toward the Ub tagged SUMO2 dimer. Our results have shown that the C-terminal domain of USP7 is crucial for USP7 efficiency and selectivity for the Ub tagged SUMO2 dimer.

Revealing USP7 Deubiquitinase Substrate Specificity by Unbiased Synthesis of Ubiquitin Tagged SUMO2.

This study reports the application of expanding genetic codes in developing protein cage-based delivery systems. The evolved Methanosarcina mazei pyrrolysyl-tRNA synthetase (PylRS)•tRNA pairs derived from directed evolution are examined to probe their recognition for para-substituted phenylalanine analogs. The evolved MmPylRS, AzFRS, harboring a wide range of substrates, is further engineered at the C-terminal region into another variant, AzFRS-MS. AzFRS-MS shows suppression of the elevated sfGFP protein amount up to 10 TAG stop codons when charging p-azido-l-phenylalanine (AzF, ), which allows the occurrence of click chemistry. Since protein nanocages used as drug delivery systems that encompass multiple drugs through a site-specific loading approach remain largely unexplored, as a proof of concept, the application of AzFRS-MS for the site-specific incorporation of AzF on human heavy chain ferritin (Ftn) is developed. The Ftn- conjugate is shown to be able to load multiple fluorescence dyes or a therapeutic agent, doxorubicin (Dox), through the strain-promoted azide-alkyne cycloaddition (SPAAC) click reaction. Aiming to selectively target Her2 breast cancer cells, Ftn--DOX conjugates fused with a HER2 receptor recognition peptide, anti-Her2/neu peptide (AHNP), is developed and demonstrated to be able to deliver Dox into the cell and to prolong the drug release. This work presents another application of evolved MmPylRS systems, whose potential in developing a variety of protein conjugates is noteworthy.

Ferritin Conjugates With Multiple Clickable Amino Acids Encoded by C-Terminal Engineered Pyrrolysyl-tRNA Synthetase.

Camouflaging is a coping strategy used by some autistic and other neurodivergent people to fit in neurotypical social contexts. The self-reported Camouflaging Autistic Traits Questionnaire has been validated for use in research with adults in some Western societies, but not in non-Western cultural-ethnic groups. We translated Camouflaging Autistic Traits Questionnaire into traditional Chinese and examined the use of this measure in Taiwanese adolescents via both self-report and caregiver-report in 100 autistic and 105 non-autistic adolescents. Both self-reported and caregiver-reported Chinese version Camouflaging Autistic Traits Questionnaire were composed of two factors (i.e. a "compensation-masking" subscale and an "assimilation" subscale). Both adolescent self-reported and caregiver-reported Chinese version Camouflaging Autistic Traits Questionnaire total score and subscales were reliable in measurement, and they highly correlated with each other. Taiwanese autistic adolescents were more likely to camouflage than non-autistic adolescents, especially on assimilation. Female autistic adolescents showed higher assimilation than male autistic adolescents. Higher camouflaging, especially assimilation, was associated with higher stress in autistic and non-autistic adolescents alike. Both self-reported and caregiver-reported Chinese version Camouflaging Autistic Traits Questionnaire were reliable and offered meaningful information to help us understand the social coping experiences of autistic and non-autistic adolescents.

Exploring camouflaging by the Chinese version Camouflaging Autistic Traits Questionnaire in Taiwanese autistic and non-autistic adolescents: An initial development.

Dementia development is a complex process in which the occurrence and sequential relationships of different diseases or conditions may construct specific patterns leading to incident dementia.

Using Hypothesis-Led Machine Learning and Hierarchical Cluster Analysis to Identify Disease Pathways Prior to Dementia: Longitudinal Cohort Study.

Once thought to be non-naturally occurring, D-amino acids (DAAs) have in recent years been revealed to play a wide range of physiological roles across the tree of life, including in human systems. Synthetic biologists have since exploited DAAs' unique biophysical properties to generate peptides and proteins with novel or enhanced functions. However, while peptides and small proteins containing DAAs can be efficiently prepared , producing large-sized heterochiral proteins poses as a major challenge mainly due to absence of pre-existing DAA translational machinery and presence of endogenous chiral discriminators. Based on our previous work demonstrating pyrrolysyl-tRNA synthetase's (PylRS') remarkable substrate polyspecificity, this work attempts to increase PylRS' ability in directly charging tRNA with D-phenylalanine analogs (DFAs). We here report a novel, polyspecific  PylRS mutant, DFRS2, capable of incorporating DFAs into proteins via ribosomal synthesis . To validate its utility,  translational DAA substitution were performed in superfolder green fluorescent protein and human heavy chain ferritin, successfully altering both proteins' physiochemical properties. Furthermore, aminoacylation kinetic assays further demonstrated aminoacylation of DFAs by DFRS2 .

Rational design of the genetic code expansion toolkit for  encoding of D-amino acids.

Osimertinib (AZD9291) is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that has shown significant clinical benefits in patients with EGFR-sensitizing mutations or the EGFR T790M mutation. The homologous recombination (HR) pathway is crucial for repairing DNA double-strand breaks (DSBs). Rad51 plays a central role in HR, facilitating the search for homology and promoting DNA strand exchange between homologous DNA molecules. Rad51 is overexpressed in numerous types of cancer cells. B02, a specific small molecule inhibitor of Rad51, inhibits the DNA strand exchange activity of Rad51. Previous studies have indicated that B02 disrupted Rad51 foci formation in response to DNA damage and inhibited DSBs repair in human cells and sensitized them to chemotherapeutic drugs in vitro and in vivo. However, the potential therapeutic effects of combining osimertinib with a Rad51 inhibitor are not well understood. The aim of this study was to elucidate whether the downregulation of Rad51 expression and activity can enhance the osimertinib-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells.

Article	Year
Trends and factors associated with antipsychotic use among elderly patients with dementia in Taiwan from 2005 to 2013: a population-based study. International clinical psychopharmacology\| PubMed ID: 28542035	2017
Probing the Active Site of Deubiquitinase USP30 with Noncanonical Tryptophan Analogues. Biochemistry\| PubMed ID: 32484330	2020
Revealing USP7 Deubiquitinase Substrate Specificity by Unbiased Synthesis of Ubiquitin Tagged SUMO2. Biochemistry\| PubMed ID: 33006472	2020
Ferritin Conjugates With Multiple Clickable Amino Acids Encoded by C-Terminal Engineered Pyrrolysyl-tRNA Synthetase. Frontiers in chemistry\| PubMed ID: 34900939	2021
Exploring camouflaging by the Chinese version Camouflaging Autistic Traits Questionnaire in Taiwanese autistic and non-autistic adolescents: An initial development. Autism : the international journal of research and practice\| PubMed ID: 37427427	2024
Using Hypothesis-Led Machine Learning and Hierarchical Cluster Analysis to Identify Disease Pathways Prior to Dementia: Longitudinal Cohort Study. Journal of medical Internet research\| PubMed ID: 37494081	2023
Rational design of the genetic code expansion toolkit for encoding of D-amino acids. Frontiers in genetics\| PubMed ID: 37904728	2023
Downregulation of Rad51 Expression and Activity Potentiates the Cytotoxic Effect of Osimertinib in Human Non-Small Cell Lung Cancer Cells. Chemotherapy\| PubMed ID: 39128459	2025

Pei-Jung Chen

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