Northern Blot Research Articles

RNA Blotting by Electrotransfer and RNA Detection.

Northern blot, or RNA blot, is a widely used technique in molecular biology to detect and semi-quantify specific RNAs. The advantage of this method is its ability to simultaneously estimate the sizes and quantities of degraded or processed RNA products. Northern blotting involves the use of electrophoresis to separate RNA samples by size. These RNAs are then transferred and immobilized on a membrane, and the RNAs of interest are detected by hybridization using a sequence-specific labeled DNA probe. Agarose gels are typically used in routine procedures to allow for the separation and specific detection of high molecular weights (ranging from tRNA size to several kb RNAs). However, acrylamide gels are preferred when the separation of lower weight RNAs (ranging from 20 to 200 nucleotides) is required. Both approaches for RNA separation are presented here. The term "northern blot" originally referred to the capillary transfer of RNA from the electrophoresis gel to the blotting membrane. However, RNA transfer to the membrane by electrotransfer has also been proven to be a suitable and fast method for transferring RNAs from acrylamide and agarose gels to the membrane.

Northern Blotting: Protocols for Radioactive and Nonradioactive Detection of RNA.

Northern blotting is a common technique in RNA biology, allowing to detect and quantify RNAs of interest following separation by gel electrophoresis, transfer to a membrane, and hybridization of specific anti-complementary labelled probes. In this chapter, we describe our protocol for efficient RNA extraction from yeast, separation on agarose gel, and capillary transfer to a membrane. We provide two different methods for strand-specific detection of several types of RNAs using oligonucleotide probes, the first using radioactive 32P-labelled probes, the second based on nonradioactive digoxigenin-labelled probes.

Measurement of rRNA Synthesis and Degradation Rates by 3H-Uracil Labeling in Yeast.

In order to measure the actual synthesis and degradation rates (SR, DR) for rRNA in yeast, we developed a method based on the pulse labeling and quantification of newly synthesized large rRNA molecules by a known mass of cells. The SR is calculated as the ratio of new rRNA molecules (synthesized after a short [5,6-3H]-uracil pulse) to total rRNA (a proxy of cell mass), calculated by northern blotting after hybridization with a 32P-labeled rRNA probe. Then to measure the DR we perform a chase of the existing 3H-labeled rRNA for several hours during yeast culture growth. We have used this method in control experiments where the yeast cell volume varies as a way to check if the SR and DR are constant with the cell volume.

Dynamic Evolution of Poly-A Tail Lengths Visualized by RNAse H Assay and Northern Blot Using Nonradioactive Probes in Yeast.

Poly-A tail length dynamics have been extensively studied from yeast to human, mostly using reporter transcripts. Recent studies have been carried out genome-wide to determine the status of poly-A tails at steady state. However, poly-A tail measurement at equilibrium gives an overall length that reflects a mixture of the different poly-A tail sizes for a single transcript. New genome-scale techniques are emerging to estimate dynamic of poly-A tails lengths, but they are not yet routine and individual validation experiments are useful. In this chapter we describe a protocol for visualizing poly-A tail lengths following transcription inhibition for a reporter mRNA using denaturing poly-acrylamide gel electrophoresis and northern blot assay. This protocol is quick to set up, requires the purchase of only a few specific reagents, does not rely on radioactivity for RNA monitoring, and can be easily implemented in any molecular biology laboratory.

Nascent and Mature RNA Profiling by Subcellular Fractionation in Human Cells.

Transcription and RNA decay determine steady-state RNA levels in cells available for translation and RNA-mediated regulatory functions. Both processes can be assessed by various techniques, for majority, based on RNA labelling or chromatin immunoprecipitation, but require a high level of expertise. Here, we describe a cost-effective, fast, and simple protocol that enables the profiling of nascent and mature RNA in the cytoplasm, nucleoplasm, and chromatin through subcellular fractionation. The workflow can include α-amanitin inhibition of RNA Polymerase II to assess nascent RNAs as a proxy of transcriptional activity, or it can be used without this treatment to investigate distribution of partially processed or mature transcripts across distinct subcellular compartments. It is applicable for studying any of RNA biotypes, including small and long noncoding RNAs, mRNAs, and their splice variants, on both transcript-specific and transcriptome-wide scales. Nascent or mature RNAs isolated from each fraction can be further analyzed by any technique of choice (northern blot, reverse transcription, RNA sequencing).

Extensive import of nucleus-encoded tRNAs into chloroplasts of the photosynthetic lycophyte, Selaginella kraussiana

Over the course of evolution, land plant mitochondrial genomes have lost many transfer RNA (tRNA) genes and the import of nucleus-encoded tRNAs is essential for mitochondrial protein synthesis. By contrast, plastidial genomes of photosynthetic land plants generally possess a complete set of tRNA genes and the existence of plastidial tRNA import remains a long-standing question. The early vascular plants of the Selaginella genus show an extensive loss of plastidial tRNA genes while retaining photosynthetic capacity, and represent an ideal model for answering this question. Using purification, northern blot hybridization, and high-throughput tRNA sequencing, a global analysis of total and plastidial tRNA populations was undertaken in Selaginella kraussiana. We confirmed the expression of all plastidial tRNA genes and, conversely, observed that nucleus-encoded tRNAs corresponding to these plastidial tRNAs were generally excluded from the chloroplasts. We then demonstrated a selective and differential plastidial import of around forty nucleus-encoded tRNA species, likely compensating for the insufficient coding capacity of plastidial-encoded tRNAs. In-depth analysis revealed differential import of tRNA isodecoders, leading to the identification of specific situations. This includes the expression and import of nucleus-encoded tRNAs expressed from plastidial or bacterial-like genes inserted into the nuclear genome. Overall, our results confirm the existence of molecular processes that enable tRNAs to be selectively imported not only into mitochondria, as previously described, but also into chloroplasts, when necessary.

Perspective: Transcriptomics of Cryopreserved Cells

Cryopreservation is a well-known strategy to conserve genetic resources at ultra-low temperature. However, there is still limited knowledge on the cellular processes and molecular adjustments that allow cells to withstand the multiple stresses to which they are exposed during cryopreservation. To evaluate these processes, transcriptomics, the sub-discipline of omics that simultaneously examines mRNA transcripts formed by transcription from the genome, has been recently used. This article reviews recent scientific studies which use the basic principles of cryopreservation practices together with transcriptomics approaches, within the conceptual framework of cryobiomics. Moreover, the connections between factors that may be useful to optimize and validate approaches for mammalian or plant cell cryopreservation are also assessed. Transcriptomic applications are mainly performed with methods such as reverse transcriptase polymerase chain reaction (RT-PCR), simultaneous polymerase chain reaction (real-time PCR), northern blot, microarray/biochip and gene expression analysis (SAGE). Transcriptomic technologies allow a global view of gene expression profiles of different mammalian or plant cell types to be obtained before and after cryopreservation under multiple stress conditions. For these processes, small amounts of RNA enable efficient transcriptomics analysis. Transcriptomic analysis of cryopreserved mammalian and plant cells provides a conceptual way to identify the genes and their relative alterations in transcriptional abundances together with non-coding RNAs involved in important pathways related to cell viability and proliferation during and after cryopreservation. Moreover, it greatly contributes to understanding of non-fatal cryodamage and related developmental disorders in cryopreserved mammalian oocytes and sperm. In addition, single cell transcriptomics has the potential to non-invasely monitor immune actions and to diagnose the stage of the inflammatory process in kidney. Finally, qRT-PCR and RNA-seq studies have also revealed that some transcription factors are effective at inducing cold tolerance in many plants by elevating the levels of soluble sugars, proline and unsaturated fatty acids in cells. Hence transcriptomics studies may also aid investigations of the main mechanisms behind the so-called 'cryo-recalcitrance' that is observed mostly in plant cells.

Preferential cleavage of the coronavirus defective viral genome by cellular endoribonuclease with characteristics of RNase L

In testing whether coronavirus defective viral genome 12.7 (DVG12.7) with transcription regulating sequence (TRS) can synthesize subgenomic mRNA (sgmRNA) in coronavirus-infected cells, it was unexpectedly found by Northern blot assay that not only sgmRNA (designated sgmDVG 12.7) but also an RNA fragment with a size less than sgmDVG 12.7 was identified. A subsequent study demonstrated that the identified RNA fragment (designated clvDVG) was a cleaved RNA product originating from DVG12.7, and the cleaved sites were located in the loop region of stem‒loop structure and after UU and UA dinucleotides. clvDVG was also identified in mock-infected HRT-18 cells transfected with DVG12.7 transcript, indicating that cellular endoribonuclease is responsible for the cleavage. In addition, the sequence and structure surrounding the cleavage sites can affect the cleavage efficiency of DVG12.7. The cleavage features are therefore consistent with the general criteria for RNA cleavage by cellular RNase L. Furthermore, both the cleavage of rRNA and the synthesis of clvDVG were also identified in A549 cells. Because (i) the cleavage sites occurred predominantly after single-stranded UA and UU dinucleotides, (ii) the sequence and structure surrounding the cleavage sites affected the cleavage efficiency, (iii) the cleavage of rRNA is an index of the activation of RNase L, and (iv) the cleavage of both rRNA and DVG12.7 was identified in A549 cells, the results together indicated that the preferential cleavage of DVG12.7 is correlated with cellular endoribonuclease with the characteristics of RNase L and such cleavage features have not been previously characterized in coronaviruses.

Asiatic acid inhibits HBV cccDNA transcription by promoting HBx degradation

BackgroundHepatitis B virus (HBV) infection is a persistent global public health problem, and curing for chronic hepatitis B (CHB) through the application of existing antiviral drugs is beset by numerous challenges. The viral protein HBx is a critical regulatory factor in the life cycle of HBV. Targeting HBx is a promising possibility for the development of novel therapeutic strategies.MethodsThe Nano-Glo® HiBiT Lysis Detection System was used to screen the herbal monomer compound library for compounds that inhibit HBx expression. Western blotting was used to examine proteins expression. Southern blotting or Northern blotting were used to detect HBV DNA or HBV RNA. ELISA was performed to detect the HBsAg level. The effect of asiatic acid on HBV in vivo was investigated by using recombinant cccDNA mouse model.ResultsAsiatic acid, an extract of Centella asiatica, significantly reduced the HBx level. Mechanistic studies demonstrated that asiatic acid may promote the degradation of HBx in an autophagy pathway-dependent manner. Subsequently, asiatic acid was found to reduce the amount of HBx bound to covalently closed circular DNA (cccDNA) microchromosomes, and repressive chromatin modifications then occurred, ultimately inhibiting cccDNA transcriptional activity. Moreover, in HBV-infected cells and a mouse model of persistent HBV infection, asiatic acid exhibited potent anti-HBV activity, as evidenced by decreased levels of HBV RNAs, HBV DNA and HBsAg.ConclusionsAsiatic acid was identified as a compound that targets HBx, revealing its potential for application as an anti-HBV agent.

The full transcription map of cottontail rabbit papillomavirus in tumor tissues.

Cottontail rabbit papillomavirus (CRPV), the first papillomavirus associated with tumor development, has been used as a powerful model to study papillomavirus pathogenesis for more than 90 years. However, lack of a comprehensive analysis of the CRPV transcriptome has impeded the understanding of CRPV biology and molecular pathogenesis. Here, we report the construction of a complete CRPV transcription map from Hershey CRPV-induced skin tumor tissues. By using RNA-seq in combination with long-reads PacBio Iso-seq, 5' and 3' RACE, primer-walking RT-PCR, Northern blot, and RNA in situ hybridization, we demonstrated that the CRPV genome transcribes its early and late RNA transcripts unidirectionally from at least five distinct major promoters (P) and polyadenylates its transcripts at two major polyadenylation (pA) sites. The viral early transcripts are primarily transcribed from three "early" promoters, P90, P156, and P907 and polyadenylated at nt 4368 by using an early polyadenylation signal (PAS) at nt 4351. Like other low-risk human papillomaviruses and animal papillomaviruses, CRPV E6 and E7 transcripts are transcribed from three separate early promoters. Transcripts from two "late" promoters, P7525, and P1225, utilize either an early PAS for E1^E4 or a late PAS at 7399 for L2 and L1 RNA polyadenylation at nt 7415 to express capsid L2 and L1 proteins respectively. By using the mapped four 5' splice sites and three 3' splice sites, CRPV RNA transcripts undergo extensive alternative splicing to produce more than 33 viral RNA isoforms for production of at least 12 viral proteins, some of which without codon optimization are expressible in rabbit RK13 and human HEK293T cells. The constructed full CRPV transcription map in this study for the first time will enhance our understanding of the structures and expressions of CRPV genes and their contribution to molecular pathogenesis and tumorigenesis.

MIR194-2HG, a miRNA host gene activated by HNF4A, inhibits gastric cancer by regulating microRNA biogenesis

BackgroundMicroRNA host gene (MIRHG) lncRNA is a particular lncRNA subclass that can perform both typical and atypical lncRNA functions. The biological function of MIRHG lncRNA MIR194-2HG in cancer is poorly understood.MethodsLoss-of-function studies were performed in vivo and in vitro to reveal the biological function of MIR194-2HG in GC. MicroRNA PCR array, northern blotting, RNA sequencing, chromatin immunoprecipitation, and rescue assays were conducted to uncover the molecular mechanism of MIR194-2HG.ResultsIn this study, we reported an atypical lncRNA function of MIR194-2HG in GC. MIR194-2HG downregulation was clinically associated with malignant progression and poor prognosis in GC. Functional assays confirmed that MIR194-2HG knockdown significantly promoted GC proliferation and metastasis in vitro and in vivo. Mechanismically, MIR194-2HG was required for the biogenesis of miR-194 and miR-192, which were reported to be tumor-suppressor genes in GC. Moreover, hepatocyte nuclear factor HNF4A directly activated the transcription of MIR194-2HG and its derived miR-194 and miR-192. Meanwhile, BTF3L4 was proved to be a common target gene of miR-192 and miR-194. Rescue assay further confirmed that MIR194-2HG knockdown promotes GC progression through maintaining BTF3L4 overexpression in a miR-194/192-dependent manner.ConclusionThe dysregulated MIR194-2HG/BTF3L4 axis is responsible for GC progression. Targeting HNF4A to inhibit miR-192/194 expression may be a promising strategy for overcoming GC.

Alternative Splicing of the Last TKFC Intron Yields Transcripts Differentially Expressed in Human Tissues That Code In Vitro for a Protein Devoid of Triokinase and FMN Cyclase Activity.

The 18-exon human TKFC gene codes for dual-activity triokinase and FMN cyclase (TKFC) in an ORF, spanning from exon 2 to exon 18. In addition to TKFC-coding transcripts (classified as tkfc type by their intron-17 splice), databases contain evidence for alternative TKFC transcripts, but none of them has been expressed, studied, and reported in the literature. A novel full-ORF transcript was cloned from brain cDNA and sequenced (accession no. DQ344550). It results from an alternative 3' splice-site in intron 17. The cloned cDNA contains an ORF also spanning from exon 2 to exon 18 of the TKFC gene but with a 56-nt insertion between exons 17 and 18 (classified as tkfc_ins56 type). This insertion introduces an in-frame stop, and the resulting ORF codes for a shorter TKFC variant, which, after expression, is enzymatically inactive. TKFC intron-17 splicing was found to be differentially expressed in human tissues. In a multiple-tissue northern blot using oligonucleotide probes, the liver showed a strong expression of the tkfc-like splice of intron 17, and the heart preferentially expressed the tkfc_ins56-like splice. Through a comparison to global expression data from massive-expression studies of human tissues, it was inferred that the intestine preferentially expresses TKFC transcripts that contain neither of those splices. An analysis of transcript levels quantified by RNA-Seq in the GTEX database revealed an exception to this picture due to the occurrence of a non-coding short transcript with a tkfc-like splice. Altogether, the results support the occurrence of potentially relevant transcript variants of the TKFC gene, differentially expressed in human tissues. (This work is dedicated in memoriam to Professor Antonio Sillero, 1938-2024, for his lifelong mentoring and his pioneering work on triokinase).

Localized hybridization chain reaction amplifier utilizing three-dimensional DNA nanostructures for efficient and reliable microRNA imaging in living cells

MicroRNAs (miRNAs) are pivotal in regulating biological processes such as cell proliferation and disease progression. Traditional miRNA detection methods like qRT-PCR and Northern blotting do not allow for monitoring dynamic changes in living cells and typically require invasive sample collection. This research presents a robust, non-enzymatic technique known as the Localized Hybridization Chain Reaction Amplifier (LHCRA), designed for real-time, in vivo miRNA imaging. This method addresses these limitations by providing rapid and sensitive detection of miRNAs, crucial for progressing clinical diagnostics and research. The LHCRA utilizes hairpin chain reaction probes embedded within self-assembled DNA micelles (DM), significantly amplifying miRNA signals. LHCRA demonstrated exceptional performance, with a detection limit of 100 pM and a response time of 10 min. Importantly, it effectively differentiated between cancerous and normal cells using clinical peripheral blood samples, showcasing high specificity and stability under physiological conditions. Additionally, LHCRA maintained consistent performance in complex biological media, including 10 % serum and 2 U/mL DNase I, confirming its broad applicability in various diagnostic scenarios. This performance highlights LHCRA's potential as a transformative tool in miRNA-based diagnostics. The introduction of LHCRA marks a significant advancement in miRNA detection technology. By enabling accurate, non-invasive, and real-time monitoring of miRNA dynamics within living cells, this method offers substantial potential to enhance diagnostic accuracy and deepen our understanding of disease mechanisms, particularly in cancer. Thus, it could greatly improve therapeutic strategies and patient outcomes in clinical environment.

Bacterial persistence to antibiotics activated by tRNA mutations.

Bacterial persistence is a significant cause of the intractability of chronic and relapsing infections. Despite its importance, many of the underlying mechanisms are still not well understood. Antibiotic-tolerant mutants of Burkholderia thailandensis were isolated through exposure to lethal doses of AMP or MEM, followed by whole-genome sequencing to identify mutations. Subsequently, these mutants underwent comprehensive characterization via killing curves, growth curves, and persistence-fraction plots. Northern blot analysis was employed to detect uncharged tRNA, while the generation of relA and spoT null mutations served to confirm the involvement of the stringent response in this persistence mechanism. Phenotypic reversion of the persistence mutation was demonstrated by incubating the mutants without antibiotics for 2 weeks. We have discovered a novel mechanism of persistence triggered by specific mutations at positions 32 or 38 within the anticodon loop of tRNAAsp. This leads to heightened persistence through a RelA-dependent stringent response. Notably, this persistence can be easily reverted to wild-type physiology by losing the mutant tRNA allele within the tRNA gene cluster when persistence is no longer essential for survival. This distinct form of persistence underscores the novel function of tRNA mutations at positions 32 or 38 within the anticodon loop, as well as the significance of the tRNA gene cluster in conferring adaptability to regulate persistence for enhanced survival.

Simple Analysis of Gel Images With IOCBIO Gel Software.

Gel image analyses are often difficult to reproduce, as the most commonly used software, the ImageJ Gels plugin, does not automatically record any steps in the analysis process. This protocol provides detailed steps for image analysis using IOCBIO Gel software with western blot as an example; however, the protocol is applicable to all images obtained by electrophoresis, such as Southern blotting, northern blotting, and isoelectric focusing. IOCBIO Gel allows multiple sample analyses, linking the original image to all the operations performed on it, which can be stored in a central database or on a PC, ensuring ease of access and the possibility to perform corrections at each analysis stage. In addition, IOCBIO Gel is lightweight, with only minimal computer requirements. Key features • Free and open-source software for analyzing gel images. • Reproducibility. • Can be used with images obtained by electrophoresis, such as western blotting, Southern blotting, isoelectric focusing, and more.

Solamargine acts as an antiviral by interacting to MZF1 and targeting the core promoter of the hepatitis B virus gene.

Hepatitis B virus (HBV) infection is still a serious threat to global health and can lead to a variety of liver diseases, including acute and chronic hepatitis, liver cirrhosis, liver failure, hepatocellular carcinoma (HCC), and so on. At present, there are mainly two kinds of drugs for the treatment of hepatitis B at home and abroad: interferon (IFN) and nucleoside/nucleotide analogs (NAs). In recent years, natural compounds have been considered an important source for the development of new anti-HBV drugs due to their complex structure, diverse components, high efficiency, and low toxicity. Many studies have demonstrated that Solamargine has significant anticancer activity, but the antiviral effect is rarely studied. This study aimed to verify the anti-HBV effect of Solamargine and to explore the specific mechanism. The relative expression of HBV pregenomic RNA (pgRNA) was detected by reverse transcription real-time fluorescence quantitative PCR (RT-qPCR). Northern blot and western blot were used to detect the relative expression of HBV pgRNA and target protein. PCR was used in the construction of HBV pg-promoter, ENII/BCP, and a series of gene deletion mutant fluorescent reporter vectors. The fluorescence relative expression of each mutant was detected by Renilla luciferase assay. By binding to MZF1 (Myeloid zinc finger protein 1, MZF1), Solamargine inhibits HBV core promoter activity, reduces pregenomic RNA level, and inhibits HBV, achieving antiviral effects.

Recent Strategies for MicroRNA Detection: A Comprehensive Review of SERS-Based Nanobiosensors

With advances in technology, diagnostic techniques have become more sophisticated and efficient at detecting biomarkers rapidly. Biomarkers such as microRNA (miRNA), which exhibit exceptional specificity and sensitivity compared with other biomarkers, have garnered particular interest. Composed of 21–24 nucleotides, miRNAs constitute a noncoding RNA group that regulates gene expression, immune system activation, apoptosis, and other cellular processes; hence, they are frequently used as biomarkers for various diseases. This has sparked significant interest regarding the identification of the specific miRNAs implicated in many diseases. Presently, miRNA detection methods include northern blots, reverse transcription-quantitative polymerase chain reaction, and next-generation sequencing. While these methods are all sensitive, they are time-consuming, complex, and expensive, which renders them unsuitable for on-site detection. Surface-enhanced Raman scattering (SERS) can overcome these limitations to enable the sensitive and rapid detection of miRNA. This technique amplifies Raman signals, with signal enhancement levels changing sensitively depending on the distance between the target molecule and substrate. Therefore, this review covers the principle of SERS as a method for detecting miRNAs using nanomaterials, along with examples of nanomaterials and SERS applications. Based on the available literature, SERS is anticipated to enable the convenient, early diagnosis of various diseases, potentially lowering mortality rates. This review could therefore contribute significantly to the advancement of medical and diagnostic technologies.

Interferon-stimulated gene (ISG12a) suppresses hepatitis B virus replication in Huh 7 cells line

Hepatitis B virus (HBV) and its associated chronic liver disease pose a significant health hazard. Chronic HBV infection is a major contributor to the development of liver cirrhosis, liver fibrosis, and liver cancer. This study focused on ISG12a and its inhibitory effect in Huh7 cells on HBV gene expression and replication. The mammalian hepatoma cells Huh7 were transfected with the pHBV1.3 vector (pCAGGS) or HA-tagged ISG12a to determine the overexpression, to test this hypothesis further, we did knockdown or silencing by transducing Huh7 cells with lentiviruses containing shRNAs targeting ISG12a or scramble control shRNA (shControl). The expression of ISG12a was evaluated through western blot analysis. The HBsAg and HBeAg secretion in the Huh7 cells’ culture media was examined using an ELISA test. The qRT-PCR confirmed the mRNA and 3.5 mRNA Kb of ISG12a. The HBV total RNA was extracted and evaluated through a Northern blot. The isolated DNA was detected through qPCR. Additionally, a mechanistic study of enhancer II (EnhII/Cp) was examined through luciferase reporter testing. Our research findings indicate that ISG12a, an interferon-stimulated gene (ISG), plays a crucial role in suppressing the replication and gene expression of HBV. According to our study using the Huh7 cell system, overexpression of ISG12a resulted in a notable reduction in HBV protein levels as well as intracellular core-associated DNA and RNA levels. On the other hand, silencing ISG12a in Huh7 cells resulted in increased HBV RNA transcripts, DNA, and secreted proteins, indicating that ISG12a plays a role in suppressing HBV replication. Additionally, the research revealed that ISG12a inhibits the function of the EnhII/Cp promoter, which results in reduced HBV gene expression. The EnhII/Cp promoter is involved in regulating HBV gene expression, and the study showed that ISG12a restricts its activity. ISG12a may have a regulatory role in controlling the expression of HBV genes. These findings highlight the importance of ISG12a in HBV gene expression and provide valuable insights for understanding its antiviral function.

Generation and Characterization of a Novel Knockin Mouse Model Expressing PSEN1 D385A: Implications for Investigating Herbal Drug Effects in γ-Secretase Activity.

Presenilin (PSEN, PS) is essential for γ-secretase function, and mutations can disrupt amyloid-β (Aβ) production in familial Alzheimer's disease. Targeting γ-secretase is complex due to its broad involvement in physiological processes. Our aim was to create a novel knockin (KI) mouse model expressing PSEN1 D385A mutation and investigate the efficacy of a Geniposide and Ginsenoside Rg1 combination (NeuroProtect modified formula, NP-2) in restoring γ-secretase activity. Using gene manipulation, we established the PS1 D385A KI mouse model and confirmed the mutation, mRNA, and protein levels using Southern blotting, northern blotting, and western blotting, respectively. In vitro γ-secretase assay was conducted to measure γ-secretase activity, while histological analyses examined neurogenesis effects. NP-2 administration evaluated its impact on γ-secretase activity. The PS1 D385A KI homozygotes displayed severe cerebral hemorrhage, postnatal lethality, developmental disorders, reduced proliferation of neural progenitor cells, and disrupted γ-secretase function. The mutation abolished PS1 protein self-shearing, leading to compromised γ-secretase activity. NP-2 intervention effectively restored γ-secretase activity in the heterozygous mice. PS1 D385A mutant disrupted PS1 protein self-cleaving, impairing γ-secretase activity in KI mice. NP-2 restored γ-secretase function, offering potential for novel AD treatment strategies despite the challenges posed by γ-secretase's complex role in physiological processes.

A Review of Nanotechnology in microRNA Detection and Drug Delivery.

MicroRNAs (miRNAs) are small, non-coding RNAs that play a crucial role in regulating gene expression. Dysfunction in miRNAs can lead to various diseases, including cancers, neurological disorders, and cardiovascular conditions. To date, approximately 2000 miRNAs have been identified in humans. These small molecules have shown promise as disease biomarkers and potential therapeutic targets. Therefore, identifying miRNA biomarkers for diseases and developing effective miRNA drug delivery systems are essential. Nanotechnology offers promising new approaches to addressing scientific and medical challenges. Traditional miRNA detection methods include next-generation sequencing, microarrays, Northern blotting, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Nanotechnology can serve as an effective alternative to Northern blotting and RT-qPCR for miRNA detection. Moreover, nanomaterials exhibit unique properties that differ from larger counterparts, enabling miRNA therapeutics to more effectively enter target cells, reduce degradation in the bloodstream, and be released in specific tissues or cells. This paper reviews the application of nanotechnology in miRNA detection and drug delivery systems. Given that miRNA therapeutics are still in the developing stages, nanotechnology holds great promise for accelerating miRNA therapeutics development.