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1.
Cell Rep Methods ; 4(4): 100744, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38582075

ABSTRACT

A comprehensive analysis of site-specific protein O-glycosylation is hindered by the absence of a consensus O-glycosylation motif, the diversity of O-glycan structures, and the lack of a universal enzyme that cleaves attached O-glycans. Here, we report the development of a robust O-glycoproteomic workflow for analyzing complex biological samples by combining four different strategies: removal of N-glycans, complementary digestion using O-glycoprotease (IMPa) with/without another protease, glycopeptide enrichment, and mass spectrometry with fragmentation of glycopeptides using stepped collision energy. Using this workflow, we cataloged 474 O-glycopeptides on 189 O-glycosites derived from 79 O-glycoproteins from human plasma. These data revealed O-glycosylation of several abundant proteins that have not been previously reported. Because many of the proteins that contained unannotated O-glycosylation sites have been extensively studied, we wished to confirm glycosylation at these sites in a targeted fashion. Thus, we analyzed selected purified proteins (kininogen-1, fetuin-A, fibrinogen, apolipoprotein E, and plasminogen) in independent experiments and validated the previously unknown O-glycosites.


Subject(s)
Glycoproteins , Proteome , Proteomics , Workflow , Humans , Glycosylation , Glycoproteins/metabolism , Glycoproteins/chemistry , Proteomics/methods , Proteome/metabolism , Proteome/analysis , Glycopeptides/analysis , Glycopeptides/chemistry , Glycopeptides/metabolism , Kininogens/metabolism , Kininogens/chemistry , Polysaccharides/metabolism , Apolipoproteins E/metabolism , Apolipoproteins E/chemistry , Fibrinogen/metabolism , Fibrinogen/chemistry , alpha-2-HS-Glycoprotein/metabolism , alpha-2-HS-Glycoprotein/analysis
2.
Adv Mater ; : e2403896, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38663435

ABSTRACT

Small-reactor-based polymerase chain reaction (PCR) has attracted considerable attention. A significant number of tiny reactors must be prepared in parallel to capture, amplify, and accurately quantify few target genes in clinically relevant large volume, which, however, requires sophisticated microfabrication and longer sample-to-answer time. Here, single plasmonic cavity membrane is reported that not only enriches and captures few nucleic acids by taking advantage of both capillarity and hydrodynamic trapping but also quickly amplifies them for sensitive plasmonic detection. The plasmonic cavity membrane with few nanoliters in a void volume is fabricated by self-assembling gold nanorods with SiO2 tips. Simulations reveal that hydrodynamic stagnation between the SiO2 tips is mainly responsible for the trapping of the nucleic acid in the membrane. Finally, it is shown that the plasmonic cavity membrane is capable of enriching severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genes up to 20 000-fold within 1 min, amplifying within 3 min, and detecting the trace genes as low as a single copy µL-1. It is anticipated that this work not only expands the utility of PCR but also provides an innovative way of the enrichment and detection of trace biomolecules in a variety of point-of-care testing applications.

3.
ACS Nano ; 18(14): 10045-10053, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38527965

ABSTRACT

Hybridization of microbial cells with inorganic nanoparticles that could dramatically improve cellular functions such as electron transfer has been realized by the random attachment or stochastic entry of the nanoparticles. Clearly, the selective growth of inorganic nanoparticles on target functional organelles is ideal for such hybridization. Here, we report the selective growth of gold nanocrystals in the intermembrane space (IMS) of Escherichia coli by exploiting the electron transport chain (ETC). We systematically show that gold ions are permeated through porins in the outer membrane of E. coli and further reduced to gold nanocrystals by the ETC in live E. coli. We directly observe that the resulting gold nanocrystals exist only in the IMS by transmission electron microscopy measurements of cross-sectioned E. coli. Molecular dynamics simulations suggest that once gold ions are reduced to small nuclei by the ETC, the nuclei can be stably physisorbed onto ETC complexes, further supporting the ETC-mediated growth. Finally, we show that the ATP synthesis of E. coli where gold nanocrystals are formed in the IMS is up to 9 times higher than that of E. coli alone. We believe that our work can significantly contribute to not only improving microbial metabolic functions for biological energy conversion but also restoring physiological dysfunctions of microbial cells for biomedicine.


Subject(s)
Escherichia coli , Nanoparticles , Gold/chemistry , Electrons , Ions
4.
ACS Appl Mater Interfaces ; 16(13): 15730-15740, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38527279

ABSTRACT

Neural differentiation is crucial for advancing our understanding of the nervous system and developing treatments for neurological disorders. The advanced methods and the ability to manipulate the alignment, proliferation, and differentiation of stem cells are essential for studying neuronal development and synaptic interactions. However, the utilization of human induced pluripotent stem cells (iPSCs) for disease modeling of neurodegenerative conditions may be constrained by the prolonged duration and uncontrolled cell differentiation required for functional neural cell differentiation. Here, we developed a microfluidic chip to enhance the differentiation and maturation of specific neural lineages by placing aligned microelectrodes on the glass surface to regulate the neural differentiation of human iPSCs. The utilization of electrical stimulation (ES) in conjunction with neurotrophic factors (NF) significantly enhanced the efficiency in generating functional neurons from human iPSCs. We also observed that the simultaneous application of NF and ES to human iPSCs promoted their differentiation and maturation into functional neurons while increasing synaptic interactions. Our research demonstrated the effect of combining NF and ES on human iPSC-derived neural differentiation.


Subject(s)
Induced Pluripotent Stem Cells , Humans , Microfluidics , Neurons , Cell Differentiation , Nerve Growth Factors/metabolism , Electrodes
5.
Plant Commun ; 5(4): 100814, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38213026

ABSTRACT

Ambient temperature affects flowering time in plants, and the MADS-box transcription factor SHORT VEGETATIVE PHASE (SVP) plays a crucial role in the response to changes in ambient temperature. SVP protein stability is regulated by the 26S proteasome pathway and decreases at high ambient temperature, but the details of SVP degradation are unclear. Here, we show that SVP degradation at high ambient temperature is mediated by the CULLIN3-RING E3 ubiquitin ligase (CRL3) complex in Arabidopsis thaliana. We identified a previously uncharacterized protein that interacts with SVP at high ambient temperature and contains a BTB/POZ domain. We named this protein LATE FLOWERING AT HIGH TEMPERATURE 1 (LFH1). Single mutants of LFH1 or CULLIN3A (CUL3A) showed late flowering specifically at 27°C. LFH1 protein levels increased at high ambient temperature. We found that LFH1 interacts with CUL3A in the cytoplasm and is important for SVP-CUL3A complex formation. Mutations in CUL3A and/or LFH1 led to increased SVP protein stability at high ambient temperature, suggesting that the CUL3-LFH1 complex functions in SVP degradation. Screening E2 ubiquitin-conjugating enzymes (UBCs) using RING-BOX PROTEIN 1 (RBX1), a component of the CRL3 complex, as bait identified UBC15. ubc15 mutants also showed late flowering at high ambient temperature. In vitro and in vivo ubiquitination assays using recombinant CUL3A, LFH1, RBX1, and UBC15 showed that SVP is highly ubiquitinated in an ATP-dependent manner. Collectively, these results indicate that the degradation of SVP at high ambient temperature is mediated by a CRL3 complex comprising CUL3A, LFH1, and UBC15.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Ubiquitin-Protein Ligases , Arabidopsis/metabolism , Arabidopsis Proteins/metabolism , Ligases/metabolism , Temperature , Ubiquitins/metabolism , Ubiquitin-Protein Ligases/metabolism
6.
Cancers (Basel) ; 16(2)2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38254898

ABSTRACT

NSCLC, the most common type of lung cancer, is often diagnosed late due to minimal early symptoms. Its high risk of recurrence or metastasis post-chemotherapy makes DC-based immunotherapy a promising strategy, offering targeted cancer destruction, low side effects, memory formation, and overcoming the immune evasive ability of cancers. However, the limited response to DCs pulsed with single antigens remains a significant challenge. To overcome this, we enhanced DC antigen presentation by pulsing with TAAs. Our study focused on enhancing DC-mediated immune response specificity and intensity by combinatorial pulsing of TAAs, selected for their prevalence in NSCLC. We selected four types of TAAs expressed in NSCLC and pulsed DCs with the optimal combination. Next, we administered TAAs-pulsed DCs into the LLC1 mouse model to evaluate their anti-tumor efficacy. Our results showed that TAAs-pulsed DCs significantly reduced tumor size and promoted apoptosis in tumor tissue. Moreover, TAAs-pulsed DCs significantly increased total T cells in the spleen compared to the unpulsed DCs. Additionally, in vitro stimulation of splenocytes from the TAAs-pulsed DCs showed notable T-cell proliferation and increased IFN-γ secretion. Our findings demonstrate the potential of multiple TAA pulsing to enhance the antigen-presenting capacity of DCs, thereby strengthening the immune response against tumors.

7.
Aging Cell ; 23(2): e14049, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38062989

ABSTRACT

Subcutaneous adipose tissue (SAT), a vital energy reservoir and endocrine organ for maintaining systemic glucose, lipid, and energy homeostasis, undergoes significant changes with age. However, among the existing aging-related markers, only few genes are associated with SAT aging. In this study, weighted gene co-expression network analysis was used on a transcriptome of SAT obtained from the Genotype-Tissue Expression portal to identify biologically relevant, SAT-specific, and age-related marker genes. We found modules that exhibited significant changes with age and identified GYG2 as a novel key aging associated gene. The link between GYG2 and mitochondrial function as well as brown/beige adipocytes was supported using additional bioinformatics and experimental analyses. Additionally, we identified PPARG as the transcription factor of GYG2 expression. The newly discovered GYG2 marker can be used to not only determine the age of SAT but also uncover new mechanisms underlying SAT aging.


Subject(s)
Subcutaneous Fat , Transcriptome , Humans , Adipose Tissue/metabolism , Aging/genetics , Biomarkers/metabolism , Mitochondria/genetics , Subcutaneous Fat/metabolism , Transcriptome/genetics
8.
Stem Cell Res Ther ; 14(1): 355, 2023 12 10.
Article in English | MEDLINE | ID: mdl-38072946

ABSTRACT

BACKGROUND: Urine-derived stem cells (UDSCs) can be easily isolated from urine and possess excellent stem cell characteristics, making them a promising source for cell therapeutics. Due to their kidney origin specificity, UDSCs are considered a superior therapeutic alternative for kidney diseases compared to other stem cells. To enhance the therapeutic potential of UDSCs, we developed a culture method that effectively boosts the expression of Klotho, a kidney-protective therapeutic factor. We also optimized the Good Manufacturing Practice (GMP) system to ensure stable and large-scale production of clinical-grade UDSCs from patient urine. In this study, we evaluated the in vivo safety and distribution of Klotho-enhanced UDSCs after intravenous administration in accordance with Good Laboratory Practice (GLP) regulations. METHODS: Mortality and general symptoms were continuously monitored throughout the entire examination period. We evaluated the potential toxicity of UDSCs according to the administration dosage and frequency using clinical pathological and histopathological analyses. We quantitatively assessed the in vivo distribution and retention period of UDSCs in major organs after single and repeated administration using human Alu-based qPCR analysis. We also conducted long-term monitoring for 26 weeks to assess the potential tumorigenicity. RESULTS: Klotho-enhanced UDSCs exhibited excellent homing potential, and recovered Klotho expression in injured renal tissue. Toxicologically harmful effects were not observed in all mice after a single administration of UDSCs. It was also verified that repeated administration of UDSCs did not induce significant toxicological or immunological adverse effects in all mice. Single and repeated administrated UDSCs persisted in the blood and major organs for approximately 3 days and cleared in most organs, except the lungs, within 2 weeks. UDSCs that remained in the lungs were cleared out in approximately 4-5 weeks. There were no significant differences according to the variation of sex and administration frequency. The tumors were found in the intravenous administration group but they were confirmed to be non-human origin. Based on these results, it was clarified that UDSCs have no tumorigenic potential. CONCLUSIONS: Our results demonstrate that Klotho-enhanced UDSCs can be manufactured as cell therapeutics through an optimized GMP procedure, and they can be safely administered without causing toxicity and tumorigenicity.


Subject(s)
Acute Kidney Injury , Kidney , Animals , Humans , Mice , Acute Kidney Injury/therapy , Kidney/pathology , Stem Cells/metabolism , Tissue Distribution
9.
J Control Release ; 364: 383-392, 2023 12.
Article in English | MEDLINE | ID: mdl-37914000

ABSTRACT

Cancer is a leading cause of the death worldwide. However, the conventional cancer therapy still suffers from several limitations, such as systemic side effects, poor efficacy, and patient compliance due to limited accessibility to the tumor site. To address these issues, the localized drug delivery system has emerged as a promising approach. In this study, we developed an iontophoresis-based transdermal drug delivery system (TDDS) controlled by a smartphone application for cancer treatment. Iontophoresis, a low-intensity electric current-based TDDS, enhances drug permeation across the skin to provide potential for localized drug delivery and minimize systemic side effects. The fundamental mechanism of our system was modeled using finite element analysis and its performance was corroborated through the flow-through skin permeation tests using a plastic-based microfluidic chip. The results of in vitro cell experiments and skin deposition tests successfully demonstrated that our smartphone-controlled iontophoresis system significantly enhanced the drug permeation for cancer treatment. Therefore, this hand-held smartphone-based iontophoresis TDDS could be a powerful tool for self-administrated anticancer drug delivery applications.


Subject(s)
Neoplasms , Skin Absorption , Humans , Iontophoresis/methods , Smartphone , Administration, Cutaneous , Skin/metabolism , Pharmaceutical Preparations , Drug Delivery Systems/methods , Neoplasms/drug therapy , Neoplasms/metabolism
10.
Mol Cells ; 46(11): 688-699, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37968983

ABSTRACT

We set up this study to understand the underlying mechanisms of reduced ceramides on immune cells in acute rejection (AR). The concentrations of ceramides and sphingomyelins were measured in the sera from hepatic transplant patients, skin graft mice and hepatocyte transplant mice by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Serum concentrations of C24 ceramide, C24:1 ceramide, C16:0 sphingomyelin, and C18:1 sphingomyelin were lower in liver transplantation (LT) recipients with than without AR. Comparisons with the results of LT patients with infection and cardiac transplant patients with cardiac allograft vasculopathy in humans and in mouse skin graft and hepatocyte transplant models suggested that the reduced C24 and C24:1 ceramides were specifically involved in AR. A ceramide synthase inhibitor, fumonisin B1 exacerbated allogeneic immune responses in vitro and in vivo, and reduced tolerogenic dendritic cells (tDCs), while increased P3-like plasmacytoid DCs (pDCs) in the draining lymph nodes from allogeneic skin graft mice. The results of mixed lymphocyte reactions with ceranib-2, an inhibitor of ceramidase, and C24 ceramide also support that increasing ceramide concentrations could benefit transplant recipients with AR. The results suggest increasing ceramides as novel therapeutic target for AR, where reduced ceramides were associated with the changes in DC subsets, in particular tDCs.


Subject(s)
Ceramides , Liver Transplantation , Humans , Mice , Animals , Sphingomyelins , Chromatography, Liquid , Skin Transplantation , Tandem Mass Spectrometry , Hepatocytes , Dendritic Cells
11.
Mol Cell Proteomics ; 22(11): 100661, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37806341

ABSTRACT

The postsynaptic density (PSD) of excitatory synapses contains a highly organized protein network with thousands of proteins and is a key node in the regulation of synaptic plasticity. To gain new mechanistic insight into experience-induced changes in the PSD, we examined the global dynamics of the hippocampal PSD proteome and phosphoproteome in mice following four different types of experience. Mice were trained using an inhibitory avoidance (IA) task and hippocampal PSD fractions were isolated from individual mice to investigate molecular mechanisms underlying experience-dependent remodeling of synapses. We developed a new strategy to identify and quantify the relatively low level of site-specific phosphorylation of PSD proteome from the hippocampus, by using a modified iTRAQ-based TiSH protocol. In the PSD, we identified 3938 proteins and 2761 phosphoproteins in the sequential strategy covering a total of 4968 unique protein groups (at least two peptides including a unique peptide). On the phosphoproteins, we identified a total of 6188 unambiguous phosphosites (75%

Subject(s)
Membrane Proteins , Proteome , Mice , Animals , Proteome/metabolism , Membrane Proteins/metabolism , Nerve Tissue Proteins/metabolism , Hippocampus/metabolism , Synapses/metabolism , Peptides/metabolism , Phosphoproteins/metabolism , Disks Large Homolog 4 Protein/metabolism
12.
Allergy Asthma Immunol Res ; 15(5): 682-694, 2023 09.
Article in English | MEDLINE | ID: mdl-37827983

ABSTRACT

Dysregulation of the arachidonic acid metabolic pathway is the most widely known pathomechanism of aspirin-exacerbated respiratory disease (AERD). This study aimed to perform integrative analysis of transcriptomic and epigenomic profiling with network analysis to determine the novel pathogenic features of AERD. Ten patients with asthma including 5 patients with AERD and another 5 patients with aspirin tolerant asthma (ATA) were enrolled. Nasal scraping was performed and nasal mucosa was used in omics profiling. Peripheral eosinophil counts, sputum eosinophil counts, fractional exhaled nitric oxide levels, and pulmonary function test results were evaluated. Differentially expressed genes (DEGs), differentially methylated probes (DMPs) and differentially correlated genes (DCGs) between patients with AERD and those with ATA were analyzed. Network analysis using ingenuity pathway analysis (IPA) was performed to determine the gene connection network and signaling pathways. In total, 1,736 DEGs, 1,401 DMPs, and 19 pairs for DCGs were identified. Among DCGs, genes related to vesicle transport (e.g., RAB3B and STX2) and sphingolipid dysregulation (e.g., SMPD3) were found to be hypo-methylated and up-regulated in AERD. Using the canonical pathway analysis of IPA with 78 asthma-related DEGs, signaling pathways of T helper cell differentiation/activation and Fcε receptor I were generated. Up-regulation of RORγt and FcER1A were noted in AERD. Gene expression levels of RAB3B, SYNE1, STX2, SMPD3 and RORγt were significantly associated with sputum eosinophil counts. Quantitative real-time polymerase chain reaction was performed and mRNA expression levels of STX2, SMPD3, RORγt, and FcER1A were significantly higher in AERD compared to ATA. Distinct pathogenic features were identified by using integrative multi-omics data analysis in patients with AERD.

13.
J Am Soc Mass Spectrom ; 34(10): 2087-2092, 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37657774

ABSTRACT

Although tandem mass tag (TMT)-based isobaric labeling has become a powerful approach for multiplexed protein quantitation, automating the workflow for this technique has not been easy to achieve for widespread adoption. This is because preparation of TMT-labeled peptide samples involves multiple steps ranging from protein extraction, denaturation, reduction, and alkylation to tryptic digestion, desalting, labeling, and cleanup, all of which require a high level of proficiency. The variability resulting from multiple processing steps is inherently problematic, especially with large-scale clinical studies that involve hundreds of samples where reproducibility is critical for quantitation. Here, we sought to compare the performance of a recently introduced platform, AccelerOme, for an automated proteomic workflow employing TMT labeling with the manual processing of samples. Cell pellets were prepared and subjected to a 16-plex experiment using an automated platform and a conventional manual protocol. Single-shot liquid chromatography with tandem mass spectrometry analysis revealed a higher number of proteins and peptides identified using the automated platform. Efficiency of tryptic digestion, alkylation, and TMT labeling were similar in both manual and automated processes. In addition, comparison of quantitation accuracy and precision showed similar performance in an automated workflow compared to manual sample preparation by an expert. Overall, we demonstrated that the automated platform performs at a level similar to a manual process performed by an expert for TMT-based proteomics. We anticipate that this automated workflow will increasingly replace manual pipelines and has the potential to be applied to large-scale TMT-based studies, providing robust results and high sample throughput.


Subject(s)
Proteins , Proteomics , Proteomics/methods , Workflow , Reproducibility of Results , Proteins/chemistry , Peptides , Proteome/analysis
14.
Mitochondrial DNA B Resour ; 8(8): 852-856, 2023.
Article in English | MEDLINE | ID: mdl-37583940

ABSTRACT

Pleuronectidae is a well-studied familyin the order Pleuronectiformes. In contrast, genetic research on the flatfish Acanthopsetta nadeshnyi of the Pleuronectidae family is limited. This study reports the complete mitogenome of A. nadeshnyi. The mitogenome was 17,206 bases long and included 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a putative control region. Phylogenetic analysis based on the nucleotide sequences of the 13 PCGs confirmed that A. nadeshnyi belongs to the Pleuronectidae family.

15.
Biosens Bioelectron ; 237: 115489, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37402347

ABSTRACT

Polymerase chain reaction (PCR) in small fluidic systems not only improves speed and sensitivity of deoxyribonucleic acid (DNA) amplification but also achieves high-throughput quantitative analyses. However, air bubble trapping and growth during PCR has been considered as a critical problem since it causes the failure of DNA amplification. Here we report bubble-free diatom PCR by exploiting a hierarchically porous silica structure of single-celled algae. We show that femtoliters of PCR solution can be spontaneously loaded into the diatom interior without air bubble trapping due to the surface hydrophilicity and pore structure of the diatom. We discover that a large pressure gradient between air bubbles and nanopores rapidly removes residual air bubbles through the periodically arrayed nanopores during thermal cycling. We demonstrate the DNA amplification by diatom PCR without air bubble trapping and growth. Finally, we successfully detect DNA fragments of SARS-CoV-2 with as low as 10 copies/µl by devising a microfluidic device integrated with diatoms assembly. We believe that our work can be applied to many PCR applications for innovative molecular diagnostics and provides new opportunities for naturally abundant diatoms to create innovative biomaterials in real-world applications.


Subject(s)
Biosensing Techniques , COVID-19 , Diatoms , Humans , Diatoms/genetics , Diatoms/chemistry , SARS-CoV-2/genetics , Polymerase Chain Reaction , DNA/genetics , COVID-19 Testing
16.
Foods ; 12(11)2023 May 30.
Article in English | MEDLINE | ID: mdl-37297447

ABSTRACT

In this research, the potential anti-obesity efficacy of Lactobacillus rhamnosus BST-L.601 and its fermented product (named SPY) with mashed sweet potato paste were investigated using 3T3-L1 preadipocytes and high-fat diet (HD)-induced obese mice. SPY (0-0.5 mg/mL) dose-dependently and significantly reduced lipid accumulation and TG content and the expression of adipogenic markers (C/EBPα, PPAR-γ, and aP2) and fatty acid synthetic pathway proteins (ACC and FAS) in 3T3-L1 adipocytes, demonstrating that SPY suppresses adipocyte differentiation and lipogenesis. Oral administration of SPY (4 × 107 CFU/kg body weight) to HD-induced obese mice for 12 weeks significantly reduced the body and liver weight, the size of adipocytes, and the weight of epididymal, visceral, and subcutaneous fat tissues. SPY was more effective in decreasing body weight gain in HD mice than in treatment with BST-L.601 alone. Administration of SPY or BST-L.601 also reduced the serum level of total cholesterol and LDL cholesterol and leptin secretion at a similar level. These results revealed that both SPY and BST-L.601 effectively suppress HD-induced adipogenesis and lipogenesis, suggesting that these materials would be useful in the functional foods industry to ameliorate and/or prevent obesity.

17.
Lab Chip ; 23(10): 2389-2398, 2023 05 16.
Article in English | MEDLINE | ID: mdl-37083004

ABSTRACT

Since the outbreak of coronavirus 2019 (COVID-19), detection technologies have been attracting a great deal of attention in molecular diagnosis applications. In particular, the droplet digital PCR (ddPCR) has become a promising tool as it offers absolute quantification of target nucleic acids with high specificity and sensitivity. In recent years, the combination of the isothermal amplification strategies has made ddPCR a popular method for on-site testing by enabling amplification at a constant temperature. However, the current isothermal ddPCR assays are still challenging due to inherent non-specific amplification. In this paper, we present a multiplexed droplet digital recombinase polymerase amplification (MddRPA) with precise initiation of the reaction. First, the reaction temperature and dynamic range of reverse transcription (RT) and RPA were characterized by real-time monitoring of fluorescence intensities. Using a droplet-based microfluidic chip, the master mix and the initiator were fractionated and rapidly mixed within well-confined droplets. Due to the high heat transfer and mass transfer of the droplets, the precise initiation of the amplification was enabled and the entire assay could be conducted within 30 min. The concentrations of target RNA in the range from 5 copies per µL to 2500 copies per µL could be detected with high linearity (R2 > 0.999). Furthermore, the multiplexed detection of three types of human coronaviruses was successfully demonstrated with high specificity (>96%). Finally, we compared the performance of the assay with a commercial RT-qPCR system using COVID-19 clinical samples. The MddRPA assay showed a 100% concordance with the RT-qPCR results, indicating its reliability and accuracy in detecting SARS-CoV-2 nucleic acids in clinical samples. Therefore, our MddRPA assay with rapid detection, precise quantification, and multiplexing capability would be an interesting method for molecular diagnosis of viral infections.


Subject(s)
COVID-19 , Recombinases , Humans , COVID-19/diagnosis , SARS-CoV-2/genetics , Reproducibility of Results , RNA , Sensitivity and Specificity , Real-Time Polymerase Chain Reaction/methods , Nucleic Acid Amplification Techniques/methods , RNA, Viral/genetics , RNA, Viral/analysis
18.
Mitochondrial DNA B Resour ; 8(2): 224-228, 2023.
Article in English | MEDLINE | ID: mdl-36816056

ABSTRACT

Microstomus achne (Jordan and Starks, 1904) is an economically valuable flatfish belonging to the family Pleuronectidae and the only flatfish that inhabits Korea. Here, we report on the complete mitochondrial genome of M. achne and the phylogenetic relationship between close species. The mitogenome is 16,971 bp long and encodes 13 protein-coding genes (PCGs), 22 transfer RNAs, and two ribosomal RNAs. The phylogenetic analysis showed that M. achne clustered with Glyptocephalus stelleri, which supports the conclusion that M. achne belongs to the family Pleuronectidae. The results of this study provide a better understanding of M. achne.

19.
Biochip J ; 17(1): 112-119, 2023.
Article in English | MEDLINE | ID: mdl-36687365

ABSTRACT

Since coronavirus disease 2019 (COVID-19) pandemic rapidly spread worldwide, there is an urgent demand for accurate and suitable nucleic acid detection technology. Although the conventional threshold-based algorithms have been used for processing images of droplet digital polymerase chain reaction (ddPCR), there are still challenges from noise and irregular size of droplets. Here, we present a combined method of the mask region convolutional neural network (Mask R-CNN)-based image detection algorithm and Gaussian mixture model (GMM)-based thresholding algorithm. This novel approach significantly reduces false detection rate and achieves highly accurate prediction model in a ddPCR image processing. We demonstrated that how deep learning improved the overall performance in a ddPCR image processing. Therefore, our study could be a promising method in nucleic acid detection technology.

20.
Nano Lett ; 22(24): 9861-9868, 2022 12 28.
Article in English | MEDLINE | ID: mdl-36484527

ABSTRACT

Plasmonic nanocavities have been used as a novel platform for studying strong light-matter coupling, opening access to quantum chemistry, material science, and enhanced sensing. However, the biomolecular study of cavity quantum electrodynamics (QED) is lacking. Here, we report the quantum electrodynamic behavior of chlorophyll-a in a plasmonic nanocavity. We construct an extreme plasmonic nanocavity using Au nanocages with various linker molecules and Au mirrors to obtain a strong coupling regime. Plasmon resonance energy transfer (PRET)-based hyperspectral imaging is applied to study the electrodynamic behaviors of chlorophyll-a in the nanocavity. Furthermore, we observe the energy level splitting of chlorophyll-a, similar to the cavity QED effects due to the light-matter interactions in the cavity. Our study will provide insight for further studies in quantum biological electron or energy transfer, electrodynamics, the electron transport chain of mitochondria, and energy harvesting, sensing, and conversion in both biological and biophysical systems.


Subject(s)
Chlorophyll , Electrons , Biophysics , Energy Transfer , Mitochondria
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