Introduction: MicroRNAs (miRNAs) have been recognized as promising diagnostic biomarkers for Diabetic Retinopathy (DR) due to their notable upregulation in individuals with the condition. However, the development of highly sensitive miRNAs assays for the rapid diagnosis of DR in clinical settings remains a challenging task.
Methods: In this study, we introduce an enhanced CRISPR/Cas12a assay, leveraging suboptimal PAM (sPAM)-mediated Cas12a trans-cleavage in conjunction with rolling circle amplification (RCA). sPAM was found to perform better than canonical PAM (cPAM) in the detection of Cas12a-mediated ssDNA detection at low concentrations and was used instead of canonical PAM (cPAM) to mediate the detection. The parameters of reactions have also been optimized.
Results And Discussion: In comparison with cPAM, sPAM has higher sensitivity in the detection of ssDNA at concentrations lower than 10 pM by Cas12a. By replacing cPAM with sPAM in the padlock template of RCA, ultra-high sensitivity for miR-183 detection is achieved, with a detection limit of 0.40 aM. within 25 min and a linear range spanning from 1 aM. to 1 pM. Our assay also exhibits exceptional specificity in detecting miR-183 from other miRNAs. Furthermore, the applicability of our assay for the sensitive detection of miR-183 in clinical serum samples is also validated. This study introduces a groundbreaking assay with excellent performance through a simple modification, which not only addresses existing diagnostic challenges, but also opens exciting new avenues for clinical diagnosis in the realm of DR.
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http://dx.doi.org/10.3389/fbioe.2024.1444908 | DOI Listing |
Anal Chem
January 2025
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China.
Tumor-derived extracellular vesicles (T-EVs) PD-L1 are an important biomarker for predicting immunotherapy response and can help us understand the mechanism of resistance to immunotherapy. However, this is due to the interference from a large proportion of nontumor-derived EVs. It is still challenging to accurately analyze T-EVs PD-L1 in complex human fluids.
View Article and Find Full Text PDFNanoscale
January 2025
Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China.
Rolling circle amplification (RCA) is a widely used method for the synthesis of DNA nanoparticles and macro-hydrogels. Several strategies, including oscillation-promoted entanglement of DNA chains, multi-round chain amplification, hybridization between DNA chains, and hybridization with functional moieties, were applied to synthesize DNA macro-hydrogels; alternatively, flower-like nanoparticles were also produced. Here we report a straightforward yet effective method to manipulate the morphology of RCA products from nanoparticles to 3D hydrogels using an additional cold treatment step of the circular DNA template prior to elongation using phi29 DNA polymerase.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Medical Technology, Beijing Institute of Technology, Beijing, 100081, China.
A point-of-care testing (POCT) assay based on commercial HCG strip was proposed for miRNA21 detection by integrating RCA-HCR cascaded isothermal amplification with CRISPR/Cas12a. Three modules were integrated in the proposed platform: target amplification module composed of rolling circle amplification (RCA) cascaded with hybridization chain reaction (HCR), signal transduction module composed of CRISPR/Cas12a combined with HCG-agarose gel beads probes, and signal readout module composed of commercial HCG strips. The proposed RCA-HCR-CRISPR/Cas12a-HCG strip assay for miRNA21 detection had high sensitivity, and the limit of detection was as low as 37 fM.
View Article and Find Full Text PDFGenome Res
January 2025
University Medical Center Utrecht, Utrecht University, Oncode Institute, Cyclomics
Shallow genome-wide cell-free DNA (cfDNA) sequencing holds great promise for non-invasive cancer monitoring by providing reliable copy number alteration (CNA) and fragmentomic profiles. Single nucleotide variations (SNVs) are, however, much harder to identify with low sequencing depth due to sequencing errors. Here we present Nanopore Rolling Circle Amplification (RCA)-enhanced Consensus Sequencing (NanoRCS), which leverages RCA and consensus calling based on genome-wide long-read nanopore sequencing to enable simultaneous multimodal tumor fraction estimation through SNVs, CNAs, and fragmentomics.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798-7348, USA. Electronic address:
Coupling interactions between the alpha (α) subunit of the polymerase III core (α-Pol III core) and the tau (τ) subunit of the clamp loader complex (τ-CLC) are vital for efficient and rapid DNA replication in Escherichia coli (E. coli). Specific and targeted mutations in the C-terminal τ-interaction region of the Pol III α-subunit disrupted efficient coupled rolling circle DNA synthesis in vitro and caused significant genomic defects in CRISPR-Cas9 dnaE edited cell strains.
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