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Updated: Jun 20, 2025
Tissue-specific miRNA Expression Profiling in Mouse Heart Sections Using In Situ Hybridization
Published on: September 15, 2018
Sensitive fluorescence detection of miRNA-124 in cardiomyocytes under oxidative stress using a nucleic acid probe
Shuo Li1,2, Xiang-Yu Pei1,2, Xin-Yi Liu1,2
1Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266000, Shandong, China.
Abstract:
MicroRNAs (miRNAs) are small noncoding RNAs of 18-25 bases. miRNAs are also important new biomarkers that can be used for disease diagnosis in the future. Studies have shown that miR-124 levels are significantly elevated during acute myocardial infarction (AMI) and play a key role in the cardiovascular system. A variety of methods have been established to detect myocardial infarction-related miRNAs. However, most require complex miRNA extraction and isolation, and these methods are virtually undetectable when RNA levels are low in the sample. It may lead to biased results. Thus, it is necessary to develop a technique that can detect miRNA without extracting it, which means that intracellular detection is of great significance. Here, we improved the traditional silicon spheres and obtained a biosensor that could effectively capture and detect specific noncoding nucleic acids through the layer-by-layer assembly method. The sensor is protected by hyaluronic acid so it can successfully escape the lysosome into the cell and achieve detection. With the help of a full-featured microplate reader, we determined that the detection limit of the biosensor could reach 1 fM, meeting the needs of intracellular detection. At the same time, we prepared an oxidative stress cardiomyocyte infarction model and successfully captured the overexpressed miR-124 in the infarcted cells to achieve in situ detection. This study could provide a new potential tool to develop miRNAs for sensitive diagnosis in AMI, and the proposed strategy implies its potential for biomedical research.
Insights
Researchers developed a novel biosensor for detecting microRNAs (miRNAs) directly within cells, crucial for diagnosing conditions like acute myocardial infarction (AMI) without invasive sample extraction.
Area of Science:
- Biomedical Engineering
- Molecular Diagnostics
- Cardiovascular Research
Background:
- MicroRNAs (miRNAs) are key biomarkers for disease diagnosis, with miR-124 elevation linked to acute myocardial infarction (AMI).
- Existing miRNA detection methods require complex extraction, limiting sensitivity for low RNA levels and potentially causing biased results.
- Intracellular miRNA detection is significant for accurate and timely diagnosis, especially in cardiovascular diseases.
Purpose of the Study:
- To develop a novel biosensor for direct intracellular detection of specific microRNAs.
- To enable sensitive and accurate diagnosis of conditions like AMI by overcoming limitations of traditional miRNA detection methods.
Main Methods:
- Improved traditional silicon spheres using layer-by-layer assembly to create a biosensor for specific noncoding nucleic acid capture.
- Incorporated hyaluronic acid for lysosome escape, enabling intracellular sensor function.
- Utilized a microplate reader for sensitive detection and validated the biosensor in an oxidative stress cardiomyocyte infarction model.
Main Results:
- The developed biosensor achieved a detection limit of 1 fM, suitable for intracellular miRNA analysis.
- Successfully captured overexpressed miR-124 in infarcted cells, demonstrating effective in situ detection.
- The hyaluronic acid coating facilitated sensor entry into cells, bypassing lysosomal degradation.
Conclusions:
- The novel biosensor enables direct, sensitive intracellular detection of miRNAs, offering a significant advancement over existing methods.
- This technology provides a potential new tool for sensitive miRNA-based diagnosis of AMI.
- The proposed strategy has broad implications for future biomedical research and diagnostics.
