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PloS One 2024Alternative splicing (AS) is a universal phenomenon in eukaryotes, and it is still challenging to identify AS events. Several methods have been developed to identify AS...
Alternative splicing (AS) is a universal phenomenon in eukaryotes, and it is still challenging to identify AS events. Several methods have been developed to identify AS events, such as expressed sequence tags (EST), microarrays and RNA-seq. However, EST has limitations in identifying low-abundance genes, while microarray and RNA-seq are high-throughput technologies, and PCR-based technology is needed for validation. To overcome the limitations of EST and shortcomings of high-throughput technologies, we established a method to identify AS events, especially for low-abundance genes, by reverse transcription (RT) PCR with gene-specific primers (GSPs) followed by nested PCR. This process includes two major steps: 1) the use of GSPs to amplify as long as the specific gene segment and 2) multiple rounds of nested PCR to screen the AS and confirm the unknown splicing variants. With this method, we successfully identified three new splicing variants, namely, GenBank Accession No. HM623886 for the bdnf gene (GenBank GeneID: 12064), GenBank Accession No. JF417977 for the trkc gene (GenBank GeneID: 18213) and GenBank Accession No. HM623888 for the glb-18 gene (GenBank GeneID: 172485). In addition to its reliability and simplicity, the method is also cost-effective and labor-intensive. In conclusion, we developed an RT-nested PCR method using gene-specific primers to efficiently identify known and novel AS variants. This approach overcomes the limitations of existing methods for detecting rare transcripts. By enabling the discovery of new isoforms, especially for low-abundance genes, this technique can aid research into aberrant splicing in disease. Future studies can apply this method to uncover AS variants involved in cancer, neurodegeneration, and other splicing-related disorders.
Topics: Alternative Splicing; Humans; Brain-Derived Neurotrophic Factor; Reverse Transcriptase Polymerase Chain Reaction; DNA Primers
PubMed: 38935635
DOI: 10.1371/journal.pone.0305201 -
International Journal of Molecular... Jun 2024Affinity reagents, or target-binding molecules, are quite versatile and are major workhorses in molecular biology and medicine. Antibodies are the most famous and... (Review)
Review
Affinity reagents, or target-binding molecules, are quite versatile and are major workhorses in molecular biology and medicine. Antibodies are the most famous and frequently used type and they have been used for a wide range of applications, including laboratory techniques, diagnostics, and therapeutics. However, antibodies are not the only available affinity reagents and they do have significant drawbacks, including laborious and costly production. Aptamers are one potential alternative that have a variety of unique advantages. They are single stranded DNA or RNA molecules that can be selected for binding to many targets including proteins, carbohydrates, and small molecules-for which antibodies typically have low affinity. There are also a variety of cost-effective methods for producing and modifying nucleic acids in vitro without cells, whereas antibodies typically require cells or even whole animals. While there are also significant drawbacks to using aptamers in therapeutic applications, including low in vivo stability, aptamers have had success in clinical trials for treating a variety of diseases and two aptamer-based drugs have gained FDA approval. Aptamer development is still ongoing, which could lead to additional applications of aptamer therapeutics, including antitoxins, and combinatorial approaches with nanoparticles and other nucleic acid therapeutics that could improve efficacy.
Topics: Aptamers, Nucleotide; Humans; Animals; SELEX Aptamer Technique
PubMed: 38928448
DOI: 10.3390/ijms25126742 -
International Journal of Molecular... Jun 2024Selenium is an essential inorganic compound in human and animal nutrition, involved in the proper functioning of the body. As a micronutrient, it actively contributes to...
Selenium is an essential inorganic compound in human and animal nutrition, involved in the proper functioning of the body. As a micronutrient, it actively contributes to the regulation of various metabolic activities, i.e., thyroid hormone, and protection against oxidative stress. However, Se exhibits a narrow concentration window between having a positive effect and exerting a toxic effect. In higher doses, it negatively affects living organisms and causes DNA damage through the formation of free radicals. Increased reactivity of Se anions can also disrupt the integrity and function of DNA-repairing proteins. As the permissible concentration of Se in drinking water is 10 µg/L, it is vital to develop sensitive and robust methods of Se detection in aqueous samples. In this study, for the first time, we proposed a selective aptamer for selenate ion detection, chosen following the SELEX process, and its application in the construction of an electrochemical aptasensor towards SeO ions. Measurement conditions such as the used redox marker and pH value of the measurement solution were chosen. The proposed aptasensor is characterized by good selectivity and an LOD of 1 nM. Conditions for biosensor regeneration and storage were also investigated in this research.
Topics: Aptamers, Nucleotide; Selenic Acid; Biosensing Techniques; Electrochemical Techniques; Ions; SELEX Aptamer Technique; Humans; Limit of Detection
PubMed: 38928366
DOI: 10.3390/ijms25126660 -
International Journal of Molecular... Jun 2024Polymerase Chain Reaction (PCR) amplification is widely used for retrieving information from DNA storage. During the PCR amplification process, nonspecific pairing...
Polymerase Chain Reaction (PCR) amplification is widely used for retrieving information from DNA storage. During the PCR amplification process, nonspecific pairing between the 3' end of the primer and the DNA sequence can cause cross-talk in the amplification reaction, leading to the generation of interfering sequences and reduced amplification accuracy. To address this issue, we propose an efficient coding algorithm for PCR amplification information retrieval (ECA-PCRAIR). This algorithm employs variable-length scanning and pruning optimization to construct a codebook that maximizes storage density while satisfying traditional biological constraints. Subsequently, a codeword search tree is constructed based on the primer library to optimize the codebook, and a variable-length interleaver is used for constraint detection and correction, thereby minimizing the likelihood of nonspecific pairing. Experimental results demonstrate that ECA-PCRAIR can reduce the probability of nonspecific pairing between the 3' end of the primer and the DNA sequence to 2-25%, enhancing the robustness of the DNA sequences. Additionally, ECA-PCRAIR achieves a storage density of 2.14-3.67 bits per nucleotide (bits/nt), significantly improving storage capacity.
Topics: Algorithms; Polymerase Chain Reaction; DNA; Information Storage and Retrieval; DNA Primers; Base Sequence
PubMed: 38928155
DOI: 10.3390/ijms25126449 -
Genes Jun 2024Despite remarkable advances in the diagnosis of invasive fungal infections (IFIs), rapid, specific, sensitive, and cost-effective detection methods remain elusive. Due... (Review)
Review
Despite remarkable advances in the diagnosis of invasive fungal infections (IFIs), rapid, specific, sensitive, and cost-effective detection methods remain elusive. Due to their stability, ease of production, and specificity to signature molecules of fungal pathogens, short single-stranded sequences of DNA, RNA, and XNA, collectively called aptamers, have emerged as promising diagnostic markers. In this perspective, we summarize recent progress in aptamer-based diagnostic tools for IFIs and discuss how these tools could potentially meet the needs and provide economical and simple solutions for point-of-care for better management of IFIs.
Topics: Humans; Aptamers, Nucleotide; Invasive Fungal Infections; Fungi; SELEX Aptamer Technique
PubMed: 38927669
DOI: 10.3390/genes15060733 -
Biomolecules Jun 2024De-differentiation and subsequent increased proliferation and inflammation of vascular smooth muscle cells (VSMCs) is one of the mechanisms of atherogenesis. Maintaining...
De-differentiation and subsequent increased proliferation and inflammation of vascular smooth muscle cells (VSMCs) is one of the mechanisms of atherogenesis. Maintaining VSMCs in a contractile differentiated state is therefore a promising therapeutic strategy for atherosclerosis. We have reported the 18-base myogenetic oligodeoxynucleotide, iSN04, which serves as an anti-nucleolin aptamer and promotes skeletal and myocardial differentiation. The present study investigated the effect of iSN04 on VSMCs because nucleolin has been reported to contribute to VSMC de-differentiation under pathophysiological conditions. Nucleolin is localized in the nucleoplasm and nucleoli of both rat and human VSMCs. iSN04 without a carrier was spontaneously incorporated into VSMCs, indicating that iSN04 would serve as an anti-nucleolin aptamer. iSN04 treatment decreased the ratio of 5-ethynyl-2'-deoxyuridine (EdU)-positive proliferating VSMCs and increased the expression of α-smooth muscle actin, a contractile marker of VSMCs. iSN04 also suppressed angiogenesis of mouse aortic rings ex vivo, which is a model of pathological angiogenesis involved in plaque formation, growth, and rupture. These results demonstrate that antagonizing nucleolin with iSN04 preserves VSMC differentiation, providing a nucleic acid drug candidate for the treatment of vascular disease.
Topics: Nucleolin; Animals; RNA-Binding Proteins; Muscle, Smooth, Vascular; Aptamers, Nucleotide; Cell Proliferation; Phosphoproteins; Cell Differentiation; Humans; Rats; Myocytes, Smooth Muscle; Mice; Cells, Cultured; Oligodeoxyribonucleotides; Male; Rats, Sprague-Dawley; Mice, Inbred C57BL
PubMed: 38927112
DOI: 10.3390/biom14060709 -
Biomolecules Jun 2024MicroRNAs (miRNAs) are highly conserved endogenous single-stranded non-coding RNA molecules that play a crucial role in regulating gene expression to maintain normal...
Downregulation of miR-1388 Regulates the Expression of Antiviral Genes via Tumor Necrosis Factor Receptor ()-Associated Factor 3 Targeting Following poly(I:C) Stimulation in Silver Carp ().
MicroRNAs (miRNAs) are highly conserved endogenous single-stranded non-coding RNA molecules that play a crucial role in regulating gene expression to maintain normal physiological functions in fish. Nevertheless, the specific physiological role of miRNAs in lower vertebrates, particularly in comparison to mammals, remains elusive. Additionally, the mechanisms underlying the control of antiviral responses triggered by viral stimulation in fish are still not fully understood. In this study, we investigated the regulatory impact of miR-1388 on the signaling pathway mediated by IFN regulatory factor 3 (). Our findings revealed that following stimulation with the viral analog poly(I:C), the expression of miR-1388 was significantly upregulated in primary immune tissues and macrophages. Through a dual luciferase reporter assay, we corroborated a direct targeting relationship between miR-1388 and tumor necrosis factor receptor ()-associated factor 3 (). Furthermore, our study demonstrated a distinct negative post-transcriptional correlation between miR-1388 and . We observed a significant negative post-transcriptional regulatory association between miR-1388 and the levels of antiviral genes following poly(I:C) stimulation. Utilizing reporter plasmids, we elucidated the role of miR-1388 in the antiviral signaling pathway activated by . By intervening with siRNA-, we validated that miR-1388 regulates the expression of antiviral genes and the production of type I interferons () through its interaction with . Collectively, our experiments highlight the regulatory influence of miR-1388 on the -mediated signaling pathway by targeting post poly(I:C) stimulation. These findings provide compelling evidence for enhancing our understanding of the mechanisms through which fish miRNAs participate in immune responses.
Topics: Animals; MicroRNAs; Poly I-C; Carps; TNF Receptor-Associated Factor 3; Down-Regulation; Interferon Regulatory Factor-3; Gene Expression Regulation; Fish Proteins; Signal Transduction
PubMed: 38927097
DOI: 10.3390/biom14060694 -
Biomolecules May 2024Ovarian cancer (OC) is one of the most lethal gynecologic cancers that is typically diagnosed at the very late stage of disease progression. Thus, there is an unmet need...
Ovarian cancer (OC) is one of the most lethal gynecologic cancers that is typically diagnosed at the very late stage of disease progression. Thus, there is an unmet need to develop diagnostic probes for early detection of OC. One approach may rely on RNA as a molecular biomarker. In this regard, lncRNA is an RNA biomarker that is over-expressed in ovarian cancer (OC) and in cancer-associated fibroblasts (CAFs). CAFs appear early on in OC as they provide a metastatic niche for OC progression. FIT-PNAs (forced intercalation-peptide nucleic acids) are DNA analogs that are designed to fluoresce upon hybridization to their complementary RNA target sequence. In recent studies, we have shown that the introduction of cyclopentane PNAs into FIT-PNAs (cpFIT-PNA) results in superior RNA sensors. Herein, we report the design and synthesis of cpFIT-PNAs for the detection of this RNA biomarker in living OC cells (OVCAR8) and in CAFs. cpFIT-PNA was compared to FIT-PNA and the cell-penetrating peptide (CPP) of choice was either a simple one (four L-lysines) or a CPP with enhanced cellular uptake (CLIP6). The combination of CLIP6 with cpFIT-PNA resulted in a superior sensing of FLJ22447 lncRNA in OVCAR8 cells as well as in CAFs. Moreover, incubation of CLIP6-cpFIT-PNA in OVCAR8 cells leads to a significant decrease (ca. 60%) in lncRNA levels and in cell viability, highlighting the potential theranostic use of such molecules.
Topics: Humans; Ovarian Neoplasms; Female; RNA, Long Noncoding; Peptide Nucleic Acids; Cyclopentanes; Cell Line, Tumor; Biomarkers, Tumor
PubMed: 38927013
DOI: 10.3390/biom14060609 -
Applied Microbiology and Biotechnology Jun 2024The human gut microbiota refers to a diverse community of microorganisms that symbiotically exist in the human intestinal system. Altered microbial communities have been...
The human gut microbiota refers to a diverse community of microorganisms that symbiotically exist in the human intestinal system. Altered microbial communities have been linked to many human pathologies. However, there is a lack of rapid and efficient methods to assess gut microbiota signatures in practice. To address this, we established an appraisal system containing 45 quantitative real-time polymerase chain reaction (qPCR) assays targeting gut core microbes with high prevalence and/or abundance in the population. Through comparative genomic analysis, we selected novel species-specific genetic markers and primers for 31 of the 45 core microbes with no previously reported specific primers or whose primers needed improvement in specificity. We comprehensively evaluated the performance of the qPCR assays and demonstrated that they showed good sensitivity, selectivity, and quantitative linearity for each target. The limit of detection ranged from 0.1 to 1.0 pg/µL for the genomic DNA of these targets. We also demonstrated the high consistency (Pearson's r = 0.8688, P < 0.0001) between the qPCR method and metagenomics next-generation sequencing (mNGS) method in analyzing the abundance of selected bacteria in 22 human fecal samples. Moreover, we quantified the dynamic changes (over 8 weeks) of these core microbes in 14 individuals using qPCR, and considerable stability was demonstrated in most participants, albeit with significant individual differences. Overall, this study enables the simple and rapid quantification of 45 core microbes in the human gut, providing a promising tool to understand the role of gut core microbiota in human health and disease. KEY POINTS: • A panel of original qPCR assays was developed to quantify human gut core microbes. • The qPCR assays were evaluated and compared with mNGS using real fecal samples. • This method was used to dynamically profile the gut core microbiota in individuals.
Topics: Humans; Real-Time Polymerase Chain Reaction; Gastrointestinal Microbiome; Feces; Bacteria; Metagenomics; High-Throughput Nucleotide Sequencing; Sensitivity and Specificity; DNA Primers; DNA, Bacterial
PubMed: 38922447
DOI: 10.1007/s00253-024-13204-4 -
Mikrochimica Acta Jun 2024The enumeration of circulating tumor cells (CTCs) in peripheral blood plays a crucial role in the early diagnosis, recurrence monitoring, and prognosis assessment of...
The enumeration of circulating tumor cells (CTCs) in peripheral blood plays a crucial role in the early diagnosis, recurrence monitoring, and prognosis assessment of cancer patients. There is a compelling need to develop an efficient technique for the capture and identification of these rare CTCs. However, the exclusive reliance on a single criterion, such as the epithelial cell adhesion molecule (EpCAM) antibody or aptamer, for the specific recognition of epithelial CTCs is not universally suitable for clinical applications, as it usually falls short in identifying EpCAM-negative CTCs. To address this limitation, we propose a straightforward and cost-effective method involving triplex fluorescently labelled aptamers (FAM-EpCAM, Cy5-PTK7, and Texas Red-CSV) to modify FeO-loaded dendritic SiO nanocomposite (dmSiO@FeO/Apt). This multi-recognition-based strategy not only enhanced the efficiency in capturing heterogeneous CTCs, but also facilitated the rapid and accurate identification of CTCs. The capture efficiency of heterogenous CTCs reached up to 93.33%, with a detection limit as low as 5 cells/mL. Notably, the developed dmSiO@FeO/Apt nanoprobe enabled the swift identification of captured cells in just 30 min, relying solely on the fluorescently modified aptamers, which reduced the identification time by approximately 90% compared with the conventional immunocytochemistry (ICC) technique. Finally, these nanoprobe characteristics were validated using blood samples from patients with various types of cancers.
Topics: Humans; Neoplastic Cells, Circulating; Silicon Dioxide; Aptamers, Nucleotide; Nanocomposites; Fluorescent Dyes; Immunomagnetic Separation; Epithelial Cell Adhesion Molecule; Limit of Detection; Cell Line, Tumor; Ferrosoferric Oxide
PubMed: 38922365
DOI: 10.1007/s00604-024-06504-z