Ultrasensitive detection of nucleic acids is of great significance for precision medicine.Digital polymerase chain reaction(dPCR)is the most sensitive method but requires sophisticated and expensive instruments and a ...Ultrasensitive detection of nucleic acids is of great significance for precision medicine.Digital polymerase chain reaction(dPCR)is the most sensitive method but requires sophisticated and expensive instruments and a long reaction time.Digital PCR-free technologies,which mean the digital assay not relying on thermal cycling to amplify the signal for quantitative detection of nucleic acids at the singlemolecule level,include the digital isothermal amplification techniques(d IATs)and the digital clustered regularly interspaced short palindromic repeats(CRISPR)technologies.They combine the advantages of d PCR and IATs,which could be fast and simple,enabling absolute quantification of nucleic acids at a single-molecule level with minimum instrument,representing the next-generation molecular diagnostic technology.Herein,we systematically summarized the strategies and applications of various dIATs,including the digital loop-mediated isothermal amplification(dLAMP),the digital recombinase polymerase amplification(dRPA),the digital rolling circle amplification(dRCA),the digital nucleic acid sequencebased amplification(d NASBA)and the digital multiple displacement amplification(d MDA),and evaluated the pros and cons of each method.The emerging digital CRISPR technologies,including the detection mechanism of CRISPR and the various strategies for signal amplification,are also introduced comprehensively in this review.The current challenges as well as the future perspectives of the digital PCR-free technology were discussed.展开更多
Metabolism is a general term for a series of ordered chemical reactions in an organism used to maintain life,mainly divided into anabolic and catabolic metabolism.Nucleic acid therapy can not only precisely up-regulat...Metabolism is a general term for a series of ordered chemical reactions in an organism used to maintain life,mainly divided into anabolic and catabolic metabolism.Nucleic acid therapy can not only precisely up-regulate and down-regulate the expression of target genes but also correct mutated disease-causing genes,which demonstrates irreplaceable and outstanding advantages in the treatment of metabolismrelated diseases and has been applied to the clinical treatment of metabolism-related diseases.In this review,we introduce the structures of several major nucleic acid drugs and the mechanism of nucleic acid therapy.Subsequently,we describe the mechanisms of various biomolecular and tissue metabolisms and the etiology of metabolic disorders,classified according to metabolic substrates.We analyze the signal pathways and potential targets affecting the metabolism of each substrate and describe the nucleic acid drugs applied to these targets and their delivery technologies.This review aims to provide new ideas and targets for treating these diseases by investigating the role played by metabolism in developing diseases and providing guidance for the selection and design of nucleic acid drugs.展开更多
Diabetic kidney disease(DKD)is recognized as a severe complication in the development of diabetes mellitus(DM),posing a significant burden for global health.Major characteristics of DKD kidneys include tubulointerstit...Diabetic kidney disease(DKD)is recognized as a severe complication in the development of diabetes mellitus(DM),posing a significant burden for global health.Major characteristics of DKD kidneys include tubulointerstitial oxidative stress,inflammation,excessive extracellular matrix deposition,and progressing renal fibrosis.However,current treatment options are limited and cannot offer enough efficacy,thus urgently requiring novel therapeutic approaches.Tetrahedral framework nucleic acids(tFNAs)are a novel type of self-assembled DNA nanomaterial with excellent structural stability,biocompatibility,tailorable functionality,and regulatory effects on cellular behaviors.In this study,we established an in vitro high glucose(HG)-induced human renal tubular epithelial cells(HK-2 cells)pro-fibrogenic model and explored the antioxidative,anti-inflammatory,and antifibrotic capacity of tFNAs and the potential molecular mechanisms.tFNAs not only effectively alleviated oxidative stress through reactive oxygen species(ROS)-scavenging and activating the serine and threonine kinase(Akt)/nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway but also inhibited the production of proinflammatory factors such as tumor necrosis factor(TNF-α),interleukin-1β(IL-1β),and interleukin-6(IL-6)in diabetic HK-2 cells.Additionally,tFNAs significantly downregulated the expression of Collagen I andα-smooth muscle actin(α-SMA),two representative biomarkers of pro-fibrogenic myofibroblasts in the renal tubular epithelial-mesenchymal transition(EMT).Furthermore,we found that tFNAs exerted this function by inhibiting the Wnt/β-catenin signaling pathway,preventing the occurrence of EMT and fibrosis.The findings of this study demonstrated that tFNAs are naturally endowed with great potential to prevent fibrosis progress in DKD kidneys and can be further combined with emerging pharmacotherapies,providing a secure and efficient drug delivery strategy for future DKD therapy.展开更多
Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the S...Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the Systematic Evolution ofLigands by Exponential Enrichment process, exhibit high affinity and specificity toward their targets, such as DNA, RNA,proteins, and other biomolecules. Nucleic acid aptamers offer significant advantages over traditional therapeutic agents,including superior biological stability, minimal immunogenicity, and the capacity for universal chemical modifications thatenhance their in vivo performance and targeting precision. In the realm of osseous tissue repair and regeneration, a complexphysiological process essential for maintaining skeletal integrity, aptamers have shown remarkable potential in influencingmolecular pathways crucial for bone regeneration, promoting osteogenic differentiation and supporting osteoblast survival. Byengineering aptamers to regulate inflammatory responses and facilitate the proliferation and differentiation of fibroblasts,these oligonucleotides can be integrated into advanced drug delivery systems, significantly improving bone repair efficacywhile minimizing adverse effects. Aptamer-mediated strategies, including the use of siRNA and miRNA mimics or inhibitors,have shown efficacy in enhancing bone mass and microstructure. These approaches hold transformative potential for treatinga range of orthopedic conditions like osteoporosis, osteosarcoma, and osteoarthritis. This review synthesizes the molecularmechanisms and biological roles of aptamers in orthopedic diseases, emphasizing their potential to drive innovative andeffective therapeutic interventions.展开更多
The potential of messenger RNA(m RNA)as a therapeutic tool for treating diseases has garnered considerable interest,especially in the wake of the successful creation of m RNA vaccines to counter corona virus disease 2...The potential of messenger RNA(m RNA)as a therapeutic tool for treating diseases has garnered considerable interest,especially in the wake of the successful creation of m RNA vaccines to counter corona virus disease 2019(COVID-19).Nucleic acid-based drug gene therapies have emerged as exceptionally promising avenues for combating disease.Furthermore,lipid nanoparticles(LNPs)are ideal carriers for nucleic acid delivery owing to their ionic nature,which enables nucleic acids to electrostatically interact with intracellular membranes,thereby promoting efficient intracellular nucleic acid release.Unfortunately,the effectiveness of LNPs in targeting organs beyond the liver is relatively poor.Thus,enhanced extrahepatic targeting is another important property that would lead to improved in vivo delivery by LNPs.This review focuses on the fundamental characteristics and functions of LNPs developed to facilitate cellular uptake and ensure effective intracellular release of m RNAs.Promising applications,possible advantages and potential challenges associated with use of LNPs in organ specific delivery and release of m RNAs are summarized.Furthermore,the need for future research to address limitations of currently developed LNPs for clinical applications of the m RNA technology is emphasized.展开更多
Hyperglycemia resulting from diabetes mellitus(DM)exacerbates osteoporosis and fractures,damaging bone regeneration due to impaired healing capacity.Stem cell therapy offers the potential for bone repair,accelerating ...Hyperglycemia resulting from diabetes mellitus(DM)exacerbates osteoporosis and fractures,damaging bone regeneration due to impaired healing capacity.Stem cell therapy offers the potential for bone repair,accelerating the healing of bone defects by introducing stem cells with osteogenic differentiation ability.Dental follicle stem cells(DFSCs)are a newly emerging type of dental stem cells that not only have the potential for multipotent differentiation but also hold easy accessibility and can stand longterm storage.However,DM-associated oxidative stress and inflammation elevate the risk of DFSCs dysfunction and apoptosis,diminishing stem cell therapy efficacy.Recent nanomaterial advances,particularly in DNA nanostructures like tetrahedral framework nucleic acids(tFNAs),have been promising candidates for modulating cellular behaviors.Accumulating experiments have shown that tFNAs’cell proliferation and migration-promoting ability and induce osteogenic differentiation of stem cells.Meanwhile,tFNAs can scavenge reactive oxygen species(ROS)and downregulate the secretion of inflammatory factors by inhibiting various inflammation-related signaling pathways.Here,we applied tFNAs to modify DFSCs and observed enhanced osteogenic differentiation alongside ROS scavenging and anti-inflammatory effects mediated by suppressing the ROS/mitogen-activated protein kinases(MAPKs)/nuclear factor kappa-B(NF-κB)signaling pathway.This intervention reduced stem cell apoptosis,bolstering stem cell therapy efficacy in DM.Our study establishes a simple yet potent tFNAs-DFSCs system,offering potential as a bone repair agent for future DM treatment.展开更多
We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBO...We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBOV),which are intended for screening bats as well as other hosts and reservoirs of these three viruses.Our triplex NALFIA is a two-step assay format:the target nucleic acid in the sample is first amplified using tagged primers,and the tagged dsDNA amplicons are captured by antibodies immobilized on the NALFIA device,resulting in signal development from the binding of a streptavidin-colloidal gold conjugate to a biotin tag on the captured amplicons.Triplex amplification of the N gene of NiV,the UpE gene of MERS-CoV,and the Vp40 gene of REBOV was optimized,and three compatible combinations of hapten labels and antibodies were identified for end point detection.The lowest RNA copy numbers detected by the triplex NALFIA were 8.21e4 for the NiV N target,7.09e1 for the MERS-CoV UpE target,and 1.83e4 for the REBOV Vp40 target.Using simulated samples,the sensitivity and specificity for MERS-CoV and REBOV targets were estimated to be 100%,while the sensitivity and specificity for the NiV target were 91%and 93.3%,respectively.The compliance rate between triplex NALFIA and real-time RT‒PCR was 92%for the NiV N target and 100%for the MERS-CoV UpE and REBOV Vp40 targets.展开更多
[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from di...[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different development stages were detected by the colorimetry. [Result] RNA content of non-diapause pupae was 4.614 0-7.946 3 μg/mg, while diapause pupae was 4.326 0-5.885 3 μg/mg and eclosion-adult from diapause pupae was 20.779 3 μg/mg at initial stage. DNA content of non-diapause pupae was 0.448 7-0.535 0 μg/mg, while diapause pupae was 0.452 0-0.828 3 μg/mg and eclosion-adult from diapause pupae was 1.727 0 μg/mg at initial stage. [Conclusion] The nucleic acid content and change is related to the development stage.展开更多
Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of ini...Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process.展开更多
During infections,nucleic acids of pathogens are also engaged in recognition via several exogenous and cytosolic pattern recognition receptors,such as the toll-like receptors,retinoic acid inducible gene-I-like recept...During infections,nucleic acids of pathogens are also engaged in recognition via several exogenous and cytosolic pattern recognition receptors,such as the toll-like receptors,retinoic acid inducible gene-I-like receptors,and nucleotide-binding and oligomerization domain-like receptors.The binding of the pathogen-derived nucleic acids to their corresponding sensors initiates certain downstream signaling cascades culminating in the release of type-I interferons(IFNs),especially IFN-αand other cytokines to induce proinflammatory responses towards invading pathogens leading to their clearance from the host.Although these sensors are hardwired to recognize pathogen associated molecular patterns,like viral and bacterial nucleic acids,under unusual physiological conditions,such as excessive cellular stress and increased apoptosis,endogenous self-nucleic acids like DNA,RNA,and mitochondrial DNA are also released.The presence of these self-nucleic acids in extranuclear compartments or extracellular spaces or their association with certain proteins sometimes leads to the failure of discriminating mechanisms of nucleic acid sensors leading to proinflammatory responses as seen in autoimmune disorders,like systemic lupus erythematosus,psoriasis and to some extent in type 1 diabetes(T1D).This review discusses the involvement of various nucleic acid sensors in autoimmunity and discusses how aberrant recognition of self-nucleic acids by their sensors activates the innate immune responses during the pathogenesis of T1D.展开更多
Hepatocellular carcinoma(HCC), with its high incidence and mortality rate, is one of the most common malignant tumors. Despite recent development of a diagnostic and treatment method, the prognosis of HCC remains poor...Hepatocellular carcinoma(HCC), with its high incidence and mortality rate, is one of the most common malignant tumors. Despite recent development of a diagnostic and treatment method, the prognosis of HCC remains poor. Therefore, to provide optimal treatment for each patient with HCC, more precise and effective biomarkers are urgently needed which could facilitate a more detailed individualized decision-making during HCC treatment, including the following; risk assessment, early cancer detection, prediction of treatment or prognostic outcome. In the blood of cancer patients, accumulating evidence about circulating tumor cells and cell-free nucleic acids has suggested their potent clinical utilities as novel biomarker. This concept, so-called "liquid biopsy" is widely known as an alternative approach to cancer tissue biopsy. This method might facilitate a more sensitive diagnosis and better decision-making by obtaining genetic and epigenetic aberrations that are closely associated with cancer initiation and progression. In this article, we review recent developments based on the available literature on both circulating tumor cells and cell-free nucleic acids in cancer patients, especially focusing on Hepatocellular carcinoma.展开更多
The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy,yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunologi...The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy,yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved.Based on poly(lactic-co-glycolic acid)(PLGA)delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion(w/o/w)solvent evaporation method,we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E(VZV-g E)as an antigen and nucleic acids including polyinosinic-polycytidylic acid(Poly I:C)and phosphodiester Cp G oligodeoxynucleotide(Cp G ODN),encapsulated as immune stimulators.While cationic lipids(DOTAP)have more potential than neutral lipids(DOPC)for activating g E-specific cell-mediated immunity(CMI)in immunized mice,especially when g E is encapsulated in and presented on the surface of nanoparticles,PLGA particles without lipids have the greatest potential to induce not only the highest g Especific Ig G titers but also the strongest g E-specific CMI responses,including the highest proportions of interferon-c(IFNc)-and interleukin-2(IL-2)-producing CD4?/CD8?T cells according to a flow cytometry assay and the greatest numbers of IFN-c-and IL-2-producing splenocytes according to an enzyme-linked immunospot(ELISPOT)assay.These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.展开更多
To improve the clinical outcomes of cancer patients, early detection and accurate monitoring of diseases are necessary. Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression, and...To improve the clinical outcomes of cancer patients, early detection and accurate monitoring of diseases are necessary. Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression, and analyses of these changes have been increasingly utilized for diagnostic, prognostic and therapeutic purposes in malignant diseases including gastric cancer (GC). Surgical and/or biopsy specimens are generally used to understand the tumor-associated alterations; however, those approaches cannot always be performed because of their invasive characteristics and may fail to reflect current tumor dynamics and drug sensitivities, which may change during the therapeutic process. Therefore, the importance of developing a non-invasive biomarker with the ability to monitor real-time tumor dynamics should be emphasized. This concept, so called “liquid biopsy”, would provide an ideal therapeutic strategy for an individual cancer patient and would facilitate the development of “tailor-made” cancer management programs. In the blood of cancer patients, the presence and potent utilities of circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) such as DNA, mRNA and microRNA have been recognized, and their clinical relevance is attracting considerable attention. In this review, we discuss recent developments in this research field as well as the relevance and future perspectives of CTCs and cfNAs in cancer patients, especially focusing on GC.展开更多
Circulating free nucleic acids; cell free DNA and circulating micro-RNA, are found in the plasma of patients with hematologic and solid malignancies at levels higher than that of healthy individuals. In patients with ...Circulating free nucleic acids; cell free DNA and circulating micro-RNA, are found in the plasma of patients with hematologic and solid malignancies at levels higher than that of healthy individuals. In patients with hematologic malignancy cell free DNA reflects the underlying tumor mutational profile, whilst micro-RNAs reflect genetic interference mechanisms within a tumor and potentially the surrounding microenvironment and immune effector cells. These circulating nucleic acids offer a potentially simple, non-invasive, repeatable analysis that can aid in diagnosis, prognosis and therapeutic decisions in cancer treatment.展开更多
Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of fo...Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of four specially designed primers and a Bst DNA polymerase with strand displacement activity. The basic principle, characteristics, development of LAMP and its applications are summarized in this article.展开更多
Nucleic acid-based bioactive substances have recently emerged as a new class of nextgeneration therapeutics, but their development has been limited by their relatively weakdelivery into target cells. Cationic liposome...Nucleic acid-based bioactive substances have recently emerged as a new class of nextgeneration therapeutics, but their development has been limited by their relatively weakdelivery into target cells. Cationic liposomes have been studied as a means to enhance thestability of nucleic acid therapeutics in the bloodstream and improve their cellular delivery.As nucleic acid therapeutics, siRNA and plasmid DNA have been extensively tested fordelivery using cationic liposomes. This review discusses recent progress in the applicationof cationic liposomes for the delivery of nucleic acid therapeutics.展开更多
Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current...Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current therapeutic approaches lack efficacy and immunomodulatory capacity.Thus,a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance.Here,we synthesized a tetrahedral framework nucleic acid(tFNA)nanoparticle that carried resveratrol(RSV)to inhibit tissue inflammation and improve insulin sensitivity in obese mice.The prepared nanoparticles,namely tFNAs-RSV,possessed the characteristics of simple synthesis,stable properties,good water solubility,and superior biocompatibility.The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy.In high-fat diet(HFD)-fed mice,the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status.tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages.As for adaptive immunity,the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg,leading to the alleviation of insulin resistance.Furthermore,this study is the first to demonstrate that tFNAs,a nucleic acid material,possess immunomodulatory capacity.Collectively,our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice,suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.展开更多
Exosomal micro RNA(mi RNA) is an ideal candidate of noninvasive biomarker for the early diagnosis of cancer. Sensitive and accurate sensing of abnormal exosomal mi RNA plays essential role for clinical promotion due t...Exosomal micro RNA(mi RNA) is an ideal candidate of noninvasive biomarker for the early diagnosis of cancer. Sensitive and accurate sensing of abnormal exosomal mi RNA plays essential role for clinical promotion due to its close correlation with tumor proliferation and progression. Herein, a microfluidic surface-enhanced Raman scattering(SERS) sensor was proposed for an on-line detection of exosomal mi RNA based on rolling circle amplification(RCA) and tyramine signal amplification(TSA) strategy. The microfluidic chip consists of a magnetic enrichment chamber, a serpentine fluidic mixer and a plasmonic SERS substrate functionalized with capture probes. The released mi RNA activates the capture probe, triggers RCA reaction, and generates a large number of single-stranded DNA products to drive the catalysis of nanotags deposition via TSA, producing numerous “hot spots” to enhance the SERS signals. In merit of the microfluidics chip and nucleic acid-tyramine cascade amplification, the developed SERS sensor significantly improves the sensitivity for the exosomal mi RNA assay, resulting in a limit of detection(LOD) as low as 1 pmol/L and can be successfully applied in the analysis of exosomes secreted from breast tumor cells, which demonstrates the potential utility in practical applications.展开更多
Although a prophylactic vaccine is available,hepatitis B virus(HBV)remains a major cause of liver-related morbidity and mortality.Current treatment options are improving clinical outcomes in chronic hepatitis B;howeve...Although a prophylactic vaccine is available,hepatitis B virus(HBV)remains a major cause of liver-related morbidity and mortality.Current treatment options are improving clinical outcomes in chronic hepatitis B;however,true functional cure is currently the exception rather than the rule.Nucleic acid vaccines are among the emerging immunotherapies that aim to restore weakened immune function in chronically infected hosts.DNA vaccines in particular have shown promising results in vivo by reducing viral replication,breaking immune tolerance in a sustained manner,or even decimating the intranuclear covalently closed circular DNA reservoir,the hallmark of HBV treatment.Although DNA vaccines encoding surface antigens administered by conventional injection elicit HBVspecific T cell responses in humans,initial clinical trials failed to demonstrate additional therapeutic benefit when administered with nucleos(t)ide analogs.In an attempt to improve vaccine immunogenicity,several techniques have been used,including codon/promoter optimization,coadministration of cytokine adjuvants,plasmids engineered to express multiple HBV epitopes,or combinations with other immunomodulators.DNA vaccine delivery by electroporation is among the most efficient strategies to enhance the production of plasmid-derived antigens to stimulate a potent cellular and humoral anti-HBV response.Preliminary results suggest that DNA vaccination via electroporation efficiently invigorates both arms of adaptive immunity and suppresses serum HBV DNA.In contrast,the study of mRNA-based vaccines is limited to a few in vitro experiments in this area.Further studies are needed to clarify the prospects of nucleic acid vaccines for HBV cure.展开更多
Peptide nucleic acids (PNAs) are synthetic oligonucleotides with chemically modified backbones. PNAs can bind to both DNA and RNA targets in a sequence-specific manner to form PNA/DNA and PNA/RNA duplex structures. Wh...Peptide nucleic acids (PNAs) are synthetic oligonucleotides with chemically modified backbones. PNAs can bind to both DNA and RNA targets in a sequence-specific manner to form PNA/DNA and PNA/RNA duplex structures. When bound to double-stranded DNA (dsDNA) targets, the PNA molecule replaces one DNA strand in the duplex by strand invasion to form a PNA/DNA/PNA [or (PNA)2/DNA] triplex structure and the displaced DNA strand exists as a singlestranded D-loop. PNA has been used in many studies as research tools for gene regulation and gene targeting. The Dloops generated from the PNA binding have also been demonstrated for its potential in initiating transcription and inducing gene expression. PNA provides a powerful tool to study the mechanism of transcription and an innovative strategy to regulate target gene expression. An understanding of the PNA-mediated gene regulation will have important clinical implications in treatment of many human diseases including genetic, cancerous, and age-related diseases.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2023YFC2307305,2021YFF0703300)the Shenzhen Medical Research Fund(No.B2303003)+3 种基金Shenzhen Research Funding Program(Nos.JCYJ20220818102014028,RCBS20210609104339043)National Natural Science Foundation of China(No.22174167)Guangdong Basic and Applied Basic Research(No.2024A1515011281)Fundamental Research Funds for the Central Universities(No.24qnpy087)from Sun Yat-sen University。
文摘Ultrasensitive detection of nucleic acids is of great significance for precision medicine.Digital polymerase chain reaction(dPCR)is the most sensitive method but requires sophisticated and expensive instruments and a long reaction time.Digital PCR-free technologies,which mean the digital assay not relying on thermal cycling to amplify the signal for quantitative detection of nucleic acids at the singlemolecule level,include the digital isothermal amplification techniques(d IATs)and the digital clustered regularly interspaced short palindromic repeats(CRISPR)technologies.They combine the advantages of d PCR and IATs,which could be fast and simple,enabling absolute quantification of nucleic acids at a single-molecule level with minimum instrument,representing the next-generation molecular diagnostic technology.Herein,we systematically summarized the strategies and applications of various dIATs,including the digital loop-mediated isothermal amplification(dLAMP),the digital recombinase polymerase amplification(dRPA),the digital rolling circle amplification(dRCA),the digital nucleic acid sequencebased amplification(d NASBA)and the digital multiple displacement amplification(d MDA),and evaluated the pros and cons of each method.The emerging digital CRISPR technologies,including the detection mechanism of CRISPR and the various strategies for signal amplification,are also introduced comprehensively in this review.The current challenges as well as the future perspectives of the digital PCR-free technology were discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.32225029,22205240,52073287,22075289,82071552 and 22376006)National Key R&D Program of China(No.2023YFC2605003)。
文摘Metabolism is a general term for a series of ordered chemical reactions in an organism used to maintain life,mainly divided into anabolic and catabolic metabolism.Nucleic acid therapy can not only precisely up-regulate and down-regulate the expression of target genes but also correct mutated disease-causing genes,which demonstrates irreplaceable and outstanding advantages in the treatment of metabolismrelated diseases and has been applied to the clinical treatment of metabolism-related diseases.In this review,we introduce the structures of several major nucleic acid drugs and the mechanism of nucleic acid therapy.Subsequently,we describe the mechanisms of various biomolecular and tissue metabolisms and the etiology of metabolic disorders,classified according to metabolic substrates.We analyze the signal pathways and potential targets affecting the metabolism of each substrate and describe the nucleic acid drugs applied to these targets and their delivery technologies.This review aims to provide new ideas and targets for treating these diseases by investigating the role played by metabolism in developing diseases and providing guidance for the selection and design of nucleic acid drugs.
基金supported by the National Natural Science Foundation of China(No.82101077)Sichuan Science and Technology Program(No.2023NSFSC1516)+2 种基金Postdoctoral Science Foundation of China(Nos.2021M692271,2023T160455)West China School/Hospital of Stomatology Sichuan University,No.RCDWJS2023-5,Fundamental Research Funds for the Central UniversitiesResearch and Develop Program,West China Hospital of Stomatology Sichuan University.
文摘Diabetic kidney disease(DKD)is recognized as a severe complication in the development of diabetes mellitus(DM),posing a significant burden for global health.Major characteristics of DKD kidneys include tubulointerstitial oxidative stress,inflammation,excessive extracellular matrix deposition,and progressing renal fibrosis.However,current treatment options are limited and cannot offer enough efficacy,thus urgently requiring novel therapeutic approaches.Tetrahedral framework nucleic acids(tFNAs)are a novel type of self-assembled DNA nanomaterial with excellent structural stability,biocompatibility,tailorable functionality,and regulatory effects on cellular behaviors.In this study,we established an in vitro high glucose(HG)-induced human renal tubular epithelial cells(HK-2 cells)pro-fibrogenic model and explored the antioxidative,anti-inflammatory,and antifibrotic capacity of tFNAs and the potential molecular mechanisms.tFNAs not only effectively alleviated oxidative stress through reactive oxygen species(ROS)-scavenging and activating the serine and threonine kinase(Akt)/nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway but also inhibited the production of proinflammatory factors such as tumor necrosis factor(TNF-α),interleukin-1β(IL-1β),and interleukin-6(IL-6)in diabetic HK-2 cells.Additionally,tFNAs significantly downregulated the expression of Collagen I andα-smooth muscle actin(α-SMA),two representative biomarkers of pro-fibrogenic myofibroblasts in the renal tubular epithelial-mesenchymal transition(EMT).Furthermore,we found that tFNAs exerted this function by inhibiting the Wnt/β-catenin signaling pathway,preventing the occurrence of EMT and fibrosis.The findings of this study demonstrated that tFNAs are naturally endowed with great potential to prevent fibrosis progress in DKD kidneys and can be further combined with emerging pharmacotherapies,providing a secure and efficient drug delivery strategy for future DKD therapy.
基金Key research and development projects of Sichuan Science and Technology Plan Project(2024YFFK0135)Fujian Provincial Natural Science Foundation of China(2024J011450).
文摘Precision medicine has become a cornerstone in modern therapeutic strategies, with nucleic acid aptamers emerging aspivotal tools due to their unique properties. These oligonucleotide fragments, selected through the Systematic Evolution ofLigands by Exponential Enrichment process, exhibit high affinity and specificity toward their targets, such as DNA, RNA,proteins, and other biomolecules. Nucleic acid aptamers offer significant advantages over traditional therapeutic agents,including superior biological stability, minimal immunogenicity, and the capacity for universal chemical modifications thatenhance their in vivo performance and targeting precision. In the realm of osseous tissue repair and regeneration, a complexphysiological process essential for maintaining skeletal integrity, aptamers have shown remarkable potential in influencingmolecular pathways crucial for bone regeneration, promoting osteogenic differentiation and supporting osteoblast survival. Byengineering aptamers to regulate inflammatory responses and facilitate the proliferation and differentiation of fibroblasts,these oligonucleotides can be integrated into advanced drug delivery systems, significantly improving bone repair efficacywhile minimizing adverse effects. Aptamer-mediated strategies, including the use of siRNA and miRNA mimics or inhibitors,have shown efficacy in enhancing bone mass and microstructure. These approaches hold transformative potential for treatinga range of orthopedic conditions like osteoporosis, osteosarcoma, and osteoarthritis. This review synthesizes the molecularmechanisms and biological roles of aptamers in orthopedic diseases, emphasizing their potential to drive innovative andeffective therapeutic interventions.
基金supported by Guang Dong Basic and Applied Basic Research Foundation(No.2023B1515120001)Shenzhen University 2035 Program for Excellent Research(Nos.00000208 and 00000225)。
文摘The potential of messenger RNA(m RNA)as a therapeutic tool for treating diseases has garnered considerable interest,especially in the wake of the successful creation of m RNA vaccines to counter corona virus disease 2019(COVID-19).Nucleic acid-based drug gene therapies have emerged as exceptionally promising avenues for combating disease.Furthermore,lipid nanoparticles(LNPs)are ideal carriers for nucleic acid delivery owing to their ionic nature,which enables nucleic acids to electrostatically interact with intracellular membranes,thereby promoting efficient intracellular nucleic acid release.Unfortunately,the effectiveness of LNPs in targeting organs beyond the liver is relatively poor.Thus,enhanced extrahepatic targeting is another important property that would lead to improved in vivo delivery by LNPs.This review focuses on the fundamental characteristics and functions of LNPs developed to facilitate cellular uptake and ensure effective intracellular release of m RNAs.Promising applications,possible advantages and potential challenges associated with use of LNPs in organ specific delivery and release of m RNAs are summarized.Furthermore,the need for future research to address limitations of currently developed LNPs for clinical applications of the m RNA technology is emphasized.
基金supported by the National Natural Science Foundation of China (Nos. 82101077, 82370929)Sichuan Science and Technology Program (Nos. 2023NSFSC1516, 2023NSFSC1706)+3 种基金Postdoctoral Science Foundation of China (Nos. 2021M692271, 2023T160455, BX20220220, 2022M722251)West China School/Hospital of Stomatology Sichuan University (No. RCDWJS2023–5)Fundamental Research Funds for the Central UniversitiesResearch and Develop Program, West China Hospital of Stomatology Sichuan University
文摘Hyperglycemia resulting from diabetes mellitus(DM)exacerbates osteoporosis and fractures,damaging bone regeneration due to impaired healing capacity.Stem cell therapy offers the potential for bone repair,accelerating the healing of bone defects by introducing stem cells with osteogenic differentiation ability.Dental follicle stem cells(DFSCs)are a newly emerging type of dental stem cells that not only have the potential for multipotent differentiation but also hold easy accessibility and can stand longterm storage.However,DM-associated oxidative stress and inflammation elevate the risk of DFSCs dysfunction and apoptosis,diminishing stem cell therapy efficacy.Recent nanomaterial advances,particularly in DNA nanostructures like tetrahedral framework nucleic acids(tFNAs),have been promising candidates for modulating cellular behaviors.Accumulating experiments have shown that tFNAs’cell proliferation and migration-promoting ability and induce osteogenic differentiation of stem cells.Meanwhile,tFNAs can scavenge reactive oxygen species(ROS)and downregulate the secretion of inflammatory factors by inhibiting various inflammation-related signaling pathways.Here,we applied tFNAs to modify DFSCs and observed enhanced osteogenic differentiation alongside ROS scavenging and anti-inflammatory effects mediated by suppressing the ROS/mitogen-activated protein kinases(MAPKs)/nuclear factor kappa-B(NF-κB)signaling pathway.This intervention reduced stem cell apoptosis,bolstering stem cell therapy efficacy in DM.Our study establishes a simple yet potent tFNAs-DFSCs system,offering potential as a bone repair agent for future DM treatment.
基金funded by the Department of Biotechnology,Ministry of Science and Technology,Government of India(DBT)under grant number ADMaC DBT-NER/LIVS/11/2012.
文摘We report the development of a triplex nucleic acid lateral flow immunoassay(NALFIA)for the detection of the genomes of Nipah virus(NiV),Middle East respiratory syndrome coronavirus(MERS-CoV)and Reston ebolavirus(REBOV),which are intended for screening bats as well as other hosts and reservoirs of these three viruses.Our triplex NALFIA is a two-step assay format:the target nucleic acid in the sample is first amplified using tagged primers,and the tagged dsDNA amplicons are captured by antibodies immobilized on the NALFIA device,resulting in signal development from the binding of a streptavidin-colloidal gold conjugate to a biotin tag on the captured amplicons.Triplex amplification of the N gene of NiV,the UpE gene of MERS-CoV,and the Vp40 gene of REBOV was optimized,and three compatible combinations of hapten labels and antibodies were identified for end point detection.The lowest RNA copy numbers detected by the triplex NALFIA were 8.21e4 for the NiV N target,7.09e1 for the MERS-CoV UpE target,and 1.83e4 for the REBOV Vp40 target.Using simulated samples,the sensitivity and specificity for MERS-CoV and REBOV targets were estimated to be 100%,while the sensitivity and specificity for the NiV target were 91%and 93.3%,respectively.The compliance rate between triplex NALFIA and real-time RT‒PCR was 92%for the NiV N target and 100%for the MERS-CoV UpE and REBOV Vp40 targets.
基金Supported by the International Advanced Forestry Science and Technology Project Imported by State Forestry Administration (2005-4-59 and 2008-4-68)~~
文摘[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different development stages were detected by the colorimetry. [Result] RNA content of non-diapause pupae was 4.614 0-7.946 3 μg/mg, while diapause pupae was 4.326 0-5.885 3 μg/mg and eclosion-adult from diapause pupae was 20.779 3 μg/mg at initial stage. DNA content of non-diapause pupae was 0.448 7-0.535 0 μg/mg, while diapause pupae was 0.452 0-0.828 3 μg/mg and eclosion-adult from diapause pupae was 1.727 0 μg/mg at initial stage. [Conclusion] The nucleic acid content and change is related to the development stage.
文摘Real-time PCR is a closed DNA amplification system that skillfully integrates biochemical, photoelectric and computer techniques. Fluorescence data acquired once per cycle provides rapid absolute quantification of initial template copy numbers as PCR products are generated. This technique significantly simplifies and accelerates the process of producing reproducible quantification of nucleic acid molecules. It not only is a sensitive, accurate and rapid quantitative method, but it also provides an easier way to calculate the absolute starting copy number of nucleic acid molecules to be tested. Together with molecular bio-techniques, like microarray, real-time PCR will play a very important role in many aspects of molecular life science such as functional gene analysis and disease molecular diagnostics. This review introduces the detailed principles and application of the real-time PCR technique, describes a recently developed system for exact quantification of AUX/IAA genes In Arabidopsis, and discusses the problems with the real-time PCR process.
文摘During infections,nucleic acids of pathogens are also engaged in recognition via several exogenous and cytosolic pattern recognition receptors,such as the toll-like receptors,retinoic acid inducible gene-I-like receptors,and nucleotide-binding and oligomerization domain-like receptors.The binding of the pathogen-derived nucleic acids to their corresponding sensors initiates certain downstream signaling cascades culminating in the release of type-I interferons(IFNs),especially IFN-αand other cytokines to induce proinflammatory responses towards invading pathogens leading to their clearance from the host.Although these sensors are hardwired to recognize pathogen associated molecular patterns,like viral and bacterial nucleic acids,under unusual physiological conditions,such as excessive cellular stress and increased apoptosis,endogenous self-nucleic acids like DNA,RNA,and mitochondrial DNA are also released.The presence of these self-nucleic acids in extranuclear compartments or extracellular spaces or their association with certain proteins sometimes leads to the failure of discriminating mechanisms of nucleic acid sensors leading to proinflammatory responses as seen in autoimmune disorders,like systemic lupus erythematosus,psoriasis and to some extent in type 1 diabetes(T1D).This review discusses the involvement of various nucleic acid sensors in autoimmunity and discusses how aberrant recognition of self-nucleic acids by their sensors activates the innate immune responses during the pathogenesis of T1D.
文摘Hepatocellular carcinoma(HCC), with its high incidence and mortality rate, is one of the most common malignant tumors. Despite recent development of a diagnostic and treatment method, the prognosis of HCC remains poor. Therefore, to provide optimal treatment for each patient with HCC, more precise and effective biomarkers are urgently needed which could facilitate a more detailed individualized decision-making during HCC treatment, including the following; risk assessment, early cancer detection, prediction of treatment or prognostic outcome. In the blood of cancer patients, accumulating evidence about circulating tumor cells and cell-free nucleic acids has suggested their potent clinical utilities as novel biomarker. This concept, so-called "liquid biopsy" is widely known as an alternative approach to cancer tissue biopsy. This method might facilitate a more sensitive diagnosis and better decision-making by obtaining genetic and epigenetic aberrations that are closely associated with cancer initiation and progression. In this article, we review recent developments based on the available literature on both circulating tumor cells and cell-free nucleic acids in cancer patients, especially focusing on Hepatocellular carcinoma.
基金financially supported by the CAMS Initiative for Innovative Medicine(Grant Number 2017-I2M3-022)Central basic scientific research in colleges and universities(Grant Number 3332019162)+1 种基金the National Natural Science Foundation of China(Grant Number 81503117)the Foundation for Studying Abroad from the China Scholarship Council(Grant Number 201808110121)
文摘The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy,yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved.Based on poly(lactic-co-glycolic acid)(PLGA)delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion(w/o/w)solvent evaporation method,we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E(VZV-g E)as an antigen and nucleic acids including polyinosinic-polycytidylic acid(Poly I:C)and phosphodiester Cp G oligodeoxynucleotide(Cp G ODN),encapsulated as immune stimulators.While cationic lipids(DOTAP)have more potential than neutral lipids(DOPC)for activating g E-specific cell-mediated immunity(CMI)in immunized mice,especially when g E is encapsulated in and presented on the surface of nanoparticles,PLGA particles without lipids have the greatest potential to induce not only the highest g Especific Ig G titers but also the strongest g E-specific CMI responses,including the highest proportions of interferon-c(IFNc)-and interleukin-2(IL-2)-producing CD4?/CD8?T cells according to a flow cytometry assay and the greatest numbers of IFN-c-and IL-2-producing splenocytes according to an enzyme-linked immunospot(ELISPOT)assay.These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.
文摘To improve the clinical outcomes of cancer patients, early detection and accurate monitoring of diseases are necessary. Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression, and analyses of these changes have been increasingly utilized for diagnostic, prognostic and therapeutic purposes in malignant diseases including gastric cancer (GC). Surgical and/or biopsy specimens are generally used to understand the tumor-associated alterations; however, those approaches cannot always be performed because of their invasive characteristics and may fail to reflect current tumor dynamics and drug sensitivities, which may change during the therapeutic process. Therefore, the importance of developing a non-invasive biomarker with the ability to monitor real-time tumor dynamics should be emphasized. This concept, so called “liquid biopsy”, would provide an ideal therapeutic strategy for an individual cancer patient and would facilitate the development of “tailor-made” cancer management programs. In the blood of cancer patients, the presence and potent utilities of circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) such as DNA, mRNA and microRNA have been recognized, and their clinical relevance is attracting considerable attention. In this review, we discuss recent developments in this research field as well as the relevance and future perspectives of CTCs and cfNAs in cancer patients, especially focusing on GC.
文摘Circulating free nucleic acids; cell free DNA and circulating micro-RNA, are found in the plasma of patients with hematologic and solid malignancies at levels higher than that of healthy individuals. In patients with hematologic malignancy cell free DNA reflects the underlying tumor mutational profile, whilst micro-RNAs reflect genetic interference mechanisms within a tumor and potentially the surrounding microenvironment and immune effector cells. These circulating nucleic acids offer a potentially simple, non-invasive, repeatable analysis that can aid in diagnosis, prognosis and therapeutic decisions in cancer treatment.
基金General Administrationof Quality Supervision, Inspection and Quarantine of China(HK001-2007).
文摘Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid amplification method, which amplifies DNA with high specificity, sensitivity, rapidity and efficiency under isothermal conditions using a set of four specially designed primers and a Bst DNA polymerase with strand displacement activity. The basic principle, characteristics, development of LAMP and its applications are summarized in this article.
基金This work was supported by Research Settlement Fund for the new faculty of Seoul National University,and grants from Ministry of Science,ICT and Future Planning(No.2013035166)from Business for Cooperative R&D between Industry,Academy,and Research Institute funded Korea Small and Medium Business Administration in 2012(No.C0010962).
文摘Nucleic acid-based bioactive substances have recently emerged as a new class of nextgeneration therapeutics, but their development has been limited by their relatively weakdelivery into target cells. Cationic liposomes have been studied as a means to enhance thestability of nucleic acid therapeutics in the bloodstream and improve their cellular delivery.As nucleic acid therapeutics, siRNA and plasmid DNA have been extensively tested fordelivery using cationic liposomes. This review discusses recent progress in the applicationof cationic liposomes for the delivery of nucleic acid therapeutics.
基金National Key R&D Program of China(2019YFA0110600)National Natural Science Foundation of China(81970916,81671031)the LU JIAXI International team program supported by the K.C.Wong Education Foundation and CAS and the Youth Innovation Promotion Association of CAS(Grant No.2016236).
文摘Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current therapeutic approaches lack efficacy and immunomodulatory capacity.Thus,a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance.Here,we synthesized a tetrahedral framework nucleic acid(tFNA)nanoparticle that carried resveratrol(RSV)to inhibit tissue inflammation and improve insulin sensitivity in obese mice.The prepared nanoparticles,namely tFNAs-RSV,possessed the characteristics of simple synthesis,stable properties,good water solubility,and superior biocompatibility.The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy.In high-fat diet(HFD)-fed mice,the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status.tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages.As for adaptive immunity,the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg,leading to the alleviation of insulin resistance.Furthermore,this study is the first to demonstrate that tFNAs,a nucleic acid material,possess immunomodulatory capacity.Collectively,our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice,suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.
基金supported by the National Natural Science Foundation of China (Nos. 31671013, 22004096, 21874105and 21705124)the China Postdoctoral Science Foundation (Nos.2019M663658 and 2020T130096ZX)+2 种基金the Natural Science Basic Research Program of Shaanxi (Nos. 2020JQ-020, 2020JQ-021 and2018JC-001)the Fundamental Research Funds for the Central Universities (No. xzy012020034)“Young Talent Support Plan” of Xi’an Jiaotong University。
文摘Exosomal micro RNA(mi RNA) is an ideal candidate of noninvasive biomarker for the early diagnosis of cancer. Sensitive and accurate sensing of abnormal exosomal mi RNA plays essential role for clinical promotion due to its close correlation with tumor proliferation and progression. Herein, a microfluidic surface-enhanced Raman scattering(SERS) sensor was proposed for an on-line detection of exosomal mi RNA based on rolling circle amplification(RCA) and tyramine signal amplification(TSA) strategy. The microfluidic chip consists of a magnetic enrichment chamber, a serpentine fluidic mixer and a plasmonic SERS substrate functionalized with capture probes. The released mi RNA activates the capture probe, triggers RCA reaction, and generates a large number of single-stranded DNA products to drive the catalysis of nanotags deposition via TSA, producing numerous “hot spots” to enhance the SERS signals. In merit of the microfluidics chip and nucleic acid-tyramine cascade amplification, the developed SERS sensor significantly improves the sensitivity for the exosomal mi RNA assay, resulting in a limit of detection(LOD) as low as 1 pmol/L and can be successfully applied in the analysis of exosomes secreted from breast tumor cells, which demonstrates the potential utility in practical applications.
文摘Although a prophylactic vaccine is available,hepatitis B virus(HBV)remains a major cause of liver-related morbidity and mortality.Current treatment options are improving clinical outcomes in chronic hepatitis B;however,true functional cure is currently the exception rather than the rule.Nucleic acid vaccines are among the emerging immunotherapies that aim to restore weakened immune function in chronically infected hosts.DNA vaccines in particular have shown promising results in vivo by reducing viral replication,breaking immune tolerance in a sustained manner,or even decimating the intranuclear covalently closed circular DNA reservoir,the hallmark of HBV treatment.Although DNA vaccines encoding surface antigens administered by conventional injection elicit HBVspecific T cell responses in humans,initial clinical trials failed to demonstrate additional therapeutic benefit when administered with nucleos(t)ide analogs.In an attempt to improve vaccine immunogenicity,several techniques have been used,including codon/promoter optimization,coadministration of cytokine adjuvants,plasmids engineered to express multiple HBV epitopes,or combinations with other immunomodulators.DNA vaccine delivery by electroporation is among the most efficient strategies to enhance the production of plasmid-derived antigens to stimulate a potent cellular and humoral anti-HBV response.Preliminary results suggest that DNA vaccination via electroporation efficiently invigorates both arms of adaptive immunity and suppresses serum HBV DNA.In contrast,the study of mRNA-based vaccines is limited to a few in vitro experiments in this area.Further studies are needed to clarify the prospects of nucleic acid vaccines for HBV cure.
文摘Peptide nucleic acids (PNAs) are synthetic oligonucleotides with chemically modified backbones. PNAs can bind to both DNA and RNA targets in a sequence-specific manner to form PNA/DNA and PNA/RNA duplex structures. When bound to double-stranded DNA (dsDNA) targets, the PNA molecule replaces one DNA strand in the duplex by strand invasion to form a PNA/DNA/PNA [or (PNA)2/DNA] triplex structure and the displaced DNA strand exists as a singlestranded D-loop. PNA has been used in many studies as research tools for gene regulation and gene targeting. The Dloops generated from the PNA binding have also been demonstrated for its potential in initiating transcription and inducing gene expression. PNA provides a powerful tool to study the mechanism of transcription and an innovative strategy to regulate target gene expression. An understanding of the PNA-mediated gene regulation will have important clinical implications in treatment of many human diseases including genetic, cancerous, and age-related diseases.
