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1.
Methods Mol Biol ; 2846: 243-261, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39141240

RESUMO

We have developed a novel method for genomic footprinting of transcription factors (TFs) that detects potential gene regulatory relationships from DNase-seq data at the nucleotide level. We introduce an assay termed cross-link (XL)-DNase-seq, designed to capture chromatin interactions of dynamic TFs. A mild cross-linking step in XL-DNase-seq improves the detection of DNase-based footprints of dynamic TFs. The footprint strengths and detectability depend on an optimal cross-linking procedure. This method may help extract novel gene regulatory circuits involving previously undetectable TFs. The XL-DNase-seq method is illustrated here for activated mouse macrophage-like cells, which share several features with inflammatory macrophages.


Assuntos
Pegada de DNA , Fatores de Transcrição , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Animais , Camundongos , Pegada de DNA/métodos , Cromatina/genética , Cromatina/metabolismo , Macrófagos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Desoxirribonucleases/metabolismo , Análise de Sequência de DNA/métodos
2.
Int Immunopharmacol ; 140: 112843, 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39098224

RESUMO

Neutrophils and macrophages confine pathogens by entrapping them in extracellular traps (ETs) through activating TLR9 function. However, plasmodial parasites secreted TatD-like DNases (TatD) to counteract ETs-mediated immune clearance. We found that TLR9 mutant mice increased susceptibility to rodent malaria, suggesting TLR9 is a key protein for host defense. We found that the proportion of neutrophils and macrophages in response to plasmodial parasite infection in the TLR9 mutant mice was significantly reduced compared to that of the WT mice. Importantly, PbTatD can directly bind to the surface TLR9 (sTLR9) on macrophages, which blocking the phosphorylation of mitogen-activated protein kinase and nuclear factor-κB, negatively regulated the signaling of ETs formation by both macrophages and neutrophils. Such, P. berghei TatD is a parasite virulence factor that can inhibit the proliferation of macrophages and neutrophils through directly binding to TLR9 receptors on the cell surface, thereby blocking the activation of the downstream MyD88-NF-kB pathways.


Assuntos
Desoxirribonucleases , Imunidade Inata , Macrófagos , Malária , Neutrófilos , Plasmodium berghei , Transdução de Sinais , Animais , Humanos , Camundongos , Desoxirribonucleases/metabolismo , Armadilhas Extracelulares/imunologia , Armadilhas Extracelulares/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Malária/imunologia , Malária/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Neutrófilos/imunologia , NF-kappa B/metabolismo , Plasmodium berghei/imunologia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/genética , Receptor Toll-Like 9/metabolismo
3.
Int J Biol Macromol ; 277(Pt 4): 134518, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39111496

RESUMO

Bacterial biofilm-related infections have become a significant global concern in public health and economy. Extracellular DNA (eDNA) is regarded as one of the key elements of extracellular polymeric substances (EPS) in bacterial biofilm, providing robust support to maintain the stability of bacterial biofilms for fighting against environmental stresses (such as antibiotics, reactive oxygen species (ROS), and hyperthermia). In this study, ternary AuAgCu hydrogels nanozyme with porous network structures were utilized for the immobilization of DNase (AuAgCu@DNase hydrogels) to realize enhanced biofilm decomposition and antibacterial therapy of MRSA. The prepared AuAgCu@DNase hydrogels can efficiently hydrolyze eDNA in biofilms so that the generated ROS and hyperthermia by laser irradiation can permeate into the interior of the biofilm to achieve deep sterilization. The typical interface interactions between AuAgCu hydrogels and DNase and the excellent photothermal-boost peroxidase-like performances of AuAgCu hydrogels take responsibility for the enhanced antibacterial activity. In the MRSA-infected wounds model, the in vivo antibacterial results revealed that the AuAgCu@DNase hydrogels possess excellent drug-resistant bacteria-killing performance with superb biocompatibility. Meanwhile, the pathological analysis of collagen deposition and fibroblast proliferation of wounds demonstrate highly satisfactory wound healing. This work offers an innovative path for developing nanozyme-enzyme antibacterial composites against drug-resistant bacteria and their biofilms.


Assuntos
Antibacterianos , Biofilmes , Desoxirribonucleases , Ouro , Hidrogéis , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Biofilmes/efeitos dos fármacos , Hidrogéis/química , Hidrogéis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Desoxirribonucleases/química , Desoxirribonucleases/farmacologia , Desoxirribonucleases/metabolismo , Ouro/química , Ouro/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Animais , Cobre/química , Cobre/farmacologia , Testes de Sensibilidade Microbiana , Camundongos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/farmacologia , Cicatrização/efeitos dos fármacos
4.
EMBO J ; 43(16): 3523-3544, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38977850

RESUMO

Cellular senescence is a response to many stressful insults. DNA damage is a consistent feature of senescent cells, but in many cases its source remains unknown. Here, we identify the cellular endonuclease caspase-activated DNase (CAD) as a critical factor in the initiation of senescence. During apoptosis, CAD is activated by caspases and cleaves the genomic DNA of the dying cell. The CAD DNase is also activated by sub-lethal signals in the apoptotic pathway, causing DNA damage in the absence of cell death. We show that sub-lethal signals in the mitochondrial apoptotic pathway induce CAD-dependent senescence. Inducers of cellular senescence, such as oncogenic RAS, type-I interferon, and doxorubicin treatment, also depend on CAD presence for senescence induction. By directly activating CAD experimentally, we demonstrate that its activity is sufficient to induce senescence in human cells. We further investigate the contribution of CAD to senescence in vivo and find substantially reduced signs of senescence in organs of ageing CAD-deficient mice. Our results show that CAD-induced DNA damage in response to various stimuli is an essential contributor to cellular senescence.


Assuntos
Senescência Celular , Dano ao DNA , Humanos , Animais , Camundongos , Apoptose , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética , Camundongos Knockout , Doxorrubicina/farmacologia
5.
Microb Biotechnol ; 17(7): e14524, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38980956

RESUMO

The coral reef microbiome plays a vital role in the health and resilience of reefs. Previous studies have examined phage therapy for coral pathogens and for modifying the coral reef microbiome, but defence systems against coral-associated bacteria have received limited attention. Phage defence systems play a crucial role in helping bacteria fight phage infections. In this study, we characterized a new defence system, Hma (HmaA-HmaB-HmaC), in the coral-associated Halomonas meridiana derived from the scleractinian coral Galaxea fascicularis. The Swi2/Snf2 helicase HmaA with a C-terminal nuclease domain exhibits antiviral activity against Escherichia phage T4. Mutation analysis revealed the nickase activity of the nuclease domain (belonging to PDD/EXK superfamily) of HmaA is essential in phage defence. Additionally, HmaA homologues are present in ~1000 bacterial and archaeal genomes. The high frequency of HmaA helicase in Halomonas strains indicates the widespread presence of these phage defence systems, while the insertion of defence genes in the hma region confirms the existence of a defence gene insertion hotspot. These findings offer insights into the diversity of phage defence systems in coral-associated bacteria and these diverse defence systems can be further applied into designing probiotics with high-phage resistance.


Assuntos
Antozoários , DNA Helicases , Halomonas , Halomonas/genética , Halomonas/enzimologia , Animais , Antozoários/microbiologia , Antozoários/virologia , DNA Helicases/genética , DNA Helicases/metabolismo , Bacteriófagos/genética , Bacteriófagos/enzimologia , Bacteriófagos/fisiologia , Desoxirribonucleases/genética , Desoxirribonucleases/metabolismo
6.
Cell Death Differ ; 31(7): 924-937, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38849575

RESUMO

Mitochondria react to infection with sub-lethal signals in the apoptosis pathway. Mitochondrial signals can be inflammatory but mechanisms are only partially understood. We show that activation of the caspase-activated DNase (CAD) mediates mitochondrial pro-inflammatory functions and substantially contributes to host defense against viral infection. In cells lacking CAD, the pro-inflammatory activity of sub-lethal signals was reduced. Experimental activation of CAD caused transient DNA-damage and a pronounced DNA damage response, involving major kinase signaling pathways, NF-κB and cGAS/STING, driving the production of interferon, cytokines/chemokines and attracting neutrophils. The transcriptional response to CAD-activation was reminiscent of the reaction to microbial infection. CAD-deficient cells had a diminished response to viral infection. Influenza virus infected CAD-deficient mice displayed reduced inflammation in lung tissue, higher viral titers and increased weight loss. Thus, CAD links the mitochondrial apoptosis system and cell death caspases to host defense. CAD-driven DNA damage is a physiological element of the inflammatory response to infection.


Assuntos
Dano ao DNA , Inflamação , Mitocôndrias , Animais , Humanos , Camundongos , Apoptose , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/deficiência , Inflamação/patologia , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Nucleotidiltransferases , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/metabolismo , Transdução de Sinais
7.
Front Cell Infect Microbiol ; 14: 1379206, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38938878

RESUMO

Enteroaggregative E. coli (EAEC) is a major cause of diarrhea worldwide. EAEC are highly adherent to cultured epithelial cells and make biofilms. Both adherence and biofilm formation rely on the presence of aggregative adherence fimbriae (AAF). We compared biofilm formation from two EAEC strains of each of the five AAF types. We found that AAF type did not correlate with the level of biofilm produced. Because the composition of the EAEC biofilm has not been fully described, we stained EAEC biofilms to determine if they contained protein, carbohydrate glycoproteins, and/or eDNA and found that EAEC biofilms contained all three extracellular components. Next, we assessed the changes to the growing or mature EAEC biofilm mediated by treatment with proteinase K, DNase, or a carbohydrate cleavage agent to target the different components of the matrix. Growing biofilms treated with proteinase K had decreased biofilm staining for more than half of the strains tested. In contrast, although sodium metaperiodate only altered the biofilm in a quantitative way for two strains, images of biofilms treated with sodium metaperiodate showed that the EAEC were more spread out. Overall, we found variability in the response of the EAEC strains to the treatments, with no one treatment producing a biofilm change for all strains. Finally, once formed, mature EAEC biofilms were more resistant to treatment than biofilms grown in the presence of those same treatments.


Assuntos
Biofilmes , Desoxirribonucleases , Endopeptidase K , Escherichia coli , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Endopeptidase K/farmacologia , Endopeptidase K/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Desoxirribonucleases/metabolismo , Desoxirribonucleases/farmacologia , Fímbrias Bacterianas/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Humanos , Ácido Periódico/farmacologia
8.
Appl Environ Microbiol ; 90(6): e0032824, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38712952

RESUMO

Cells of Vibrio fischeri colonize the light organ of Euprymna scolopes, providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of V. fischeri. To discover the gene(s) responsible for this activity, we screened a V. fischeri transposon mutant library for nuclease-deficient strains. Interestingly, only one strain, whose transposon insertion mapped to nuclease gene VF_1451, showed a complete loss of nuclease activity in our screens. A database search revealed that VF_1451 is homologous to the nuclease-encoding gene xds in Vibrio cholerae. However, V. fischeri strains lacking xds eventually revealed slight nuclease activity on plates upon prolonged incubation. This led us to hypothesize that a second secreted nuclease, identified through a database search as VF_0437, a homolog of V. cholerae dns, might be responsible for the residual nuclease activity. Here, we show that Xds and/or Dns are involved in essential aspects of V. fischeri biology, including natural transformation, aggregation, and phosphate scavenging. Furthermore, strains lacking either nuclease were outcompeted by the wild type for squid colonization. Understanding the specific role of nuclease activity in the squid colonization process represents an intriguing area of future research.IMPORTANCEFrom soil and water to host-associated secretions such as mucus, environments that bacteria inhabit are awash in DNA. Extracellular DNA (eDNA) is a nutritious resource that microbes dedicate significant energy to exploit. Calcium binds eDNA to promote cell-cell aggregation and horizontal gene transfer. eDNA hydrolysis impacts the construction of and dispersal from biofilms. Strategies in which pathogens use nucleases to avoid phagocytosis or disseminate by degrading host secretions are well-documented; significantly less is known about nucleases in mutualistic associations. This study describes the role of nucleases in the mutualism between Vibrio fischeri and its squid host Euprymna scolopes. We find that nuclease activity is an important determinant of colonization in V. fischeri, broadening our understanding of how microbes establish and maintain beneficial associations.


Assuntos
Aliivibrio fischeri , Proteínas de Bactérias , Decapodiformes , Fosfatos , Simbiose , Aliivibrio fischeri/genética , Aliivibrio fischeri/fisiologia , Aliivibrio fischeri/enzimologia , Decapodiformes/microbiologia , Animais , Fosfatos/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética
9.
J Bacteriol ; 206(6): e0027323, 2024 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-38717111

RESUMO

Type VI secretion system (T6SS) is a potent weapon employed by various Pseudomonas species to compete with neighboring microorganisms for limited nutrients and ecological niches. However, the involvement of T6SS effectors in interbacterial competition within the phytopathogen Pseudomonas syringae remains unknown. In this study, we examined two T6SS clusters in a wild-type P. syringae MB03 and verified the involvement of one cluster, namely, T6SS-1, in interbacterial competition. Additionally, our results showed that two T6SS DNase effectors, specifically Tde1 and Tde4, effectively outcompeted antagonistic bacteria, with Tde4 playing a prominent role. Furthermore, we found several cognate immunity proteins, including Tde1ia, Tde1ib, and Tde4i, which are located in the downstream loci of their corresponding effector protein genes and worked synergistically to protect MB03 cells from self-intoxication. Moreover, expression of either Tde1 or C-terminus of Tde4 in Escherichia coli cells induced DNA degradation and changes in cell morphology. Thus, our results provide new insights into the role of the T6SS effectors of P. syringae in the interbacterial competition in the natural environment. IMPORTANCE: The phytopathogen Pseudomonas syringae employs an active type VI secretion system (T6SS) to outcompete other microorganisms in the natural environment, particularly during the epiphytic growth in the phyllosphere. By examining two T6SS clusters in P. syringae MB03, T6SS-1 is found to be effective in killing Escherichia coli cells. We highlight the excellent antibacterial effect of two T6SS DNase effectors, namely, Tde1 and Tde4. Both of them function as nuclease effectors, leading to DNA degradation and cell filamentation in prey cells, ultimately resulting in cell death. Our findings deepen our understanding of the T6SS effector repertoires used in P. syringae and will facilitate the development of effective antibacterial strategies.


Assuntos
Proteínas de Bactérias , Desoxirribonucleases , Pseudomonas syringae , Sistemas de Secreção Tipo VI , Pseudomonas syringae/genética , Pseudomonas syringae/metabolismo , Pseudomonas syringae/enzimologia , Sistemas de Secreção Tipo VI/metabolismo , Sistemas de Secreção Tipo VI/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética , Regulação Bacteriana da Expressão Gênica , Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos
10.
Cell Rep ; 43(5): 114251, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38761374

RESUMO

Phagocytic macrophages are crucial for innate immunity and tissue homeostasis. Most tissue-resident macrophages develop from embryonic precursors that populate every organ before birth to lifelong self-renew. However, the mechanisms for versatile macrophage differentiation remain unknown. Here, we use in vivo genetic and cell biological analysis of the Drosophila larval hematopoietic organ, the lymph gland that produces macrophages. We show that the developmentally regulated transient activation of caspase-activated DNase (CAD)-mediated DNA strand breaks in intermediate progenitors is essential for macrophage differentiation. Insulin receptor-mediated PI3K/Akt signaling regulates the apoptosis signal-regulating kinase 1 (Ask1)/c-Jun kinase (JNK) axis to control sublethal levels of caspase activation, causing DNA strand breaks during macrophage development. Furthermore, caspase activity is also required for embryonic-origin macrophage development and efficient phagocytosis. Our study provides insights into developmental signaling and CAD-mediated DNA strand breaks associated with multifunctional and heterogeneous macrophage differentiation.


Assuntos
Diferenciação Celular , Dano ao DNA , Proteínas de Drosophila , Macrófagos , Fagocitose , Animais , Macrófagos/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Transdução de Sinais , Caspases/metabolismo , Ativação Enzimática , Desoxirribonucleases/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo
11.
Nature ; 630(8018): 961-967, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38740055

RESUMO

Although eukaryotic Argonautes have a pivotal role in post-transcriptional gene regulation through nucleic acid cleavage, some short prokaryotic Argonaute variants (pAgos) rely on auxiliary nuclease factors for efficient foreign DNA degradation1. Here we reveal the activation pathway of the DNA defence module DdmDE system, which rapidly eliminates small, multicopy plasmids from the Vibrio cholerae seventh pandemic strain (7PET)2. Through a combination of cryo-electron microscopy, biochemistry and in vivo plasmid clearance assays, we demonstrate that DdmE is a catalytically inactive, DNA-guided, DNA-targeting pAgo with a distinctive insertion domain. We observe that the helicase-nuclease DdmD transitions from an autoinhibited, dimeric complex to a monomeric state upon loading of single-stranded DNA targets. Furthermore, the complete structure of the DdmDE-guide-target handover complex provides a comprehensive view into how DNA recognition triggers processive plasmid destruction. Our work establishes a mechanistic foundation for how pAgos utilize ancillary factors to achieve plasmid clearance, and provides insights into anti-plasmid immunity in bacteria.


Assuntos
Proteínas Argonautas , Proteínas de Bactérias , Plasmídeos , Vibrio cholerae , Proteínas Argonautas/química , Proteínas Argonautas/metabolismo , Proteínas Argonautas/ultraestrutura , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/ultraestrutura , Microscopia Crioeletrônica , Desoxirribonucleases/química , Desoxirribonucleases/metabolismo , Desoxirribonucleases/ultraestrutura , DNA Helicases/química , DNA Helicases/metabolismo , DNA Helicases/ultraestrutura , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Modelos Moleculares , Plasmídeos/genética , Plasmídeos/imunologia , Plasmídeos/metabolismo , Domínios Proteicos , Multimerização Proteica , Vibrio cholerae/genética , Vibrio cholerae/imunologia , Vibrio cholerae/patogenicidade
12.
Am J Physiol Lung Cell Mol Physiol ; 326(6): L796-L804, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38651338

RESUMO

Secreted deoxyribonucleases (DNases), such as DNase-I and DNase-IL3, degrade extracellular DNA, and endogenous DNases have roles in resolving airway inflammation and guarding against autoimmune responses to nucleotides. Subsets of patients with asthma have high airway DNA levels, but information about DNase activity in health and in asthma is lacking. To characterize DNase activity in health and in asthma, we developed a novel kinetic assay using a Taqman probe sequence that is quickly cleaved by DNase-I to produce a large product signal. We used this kinetic assay to measure DNase activity in sputum from participants in the Severe Asthma Research Program (SARP)-3 (n = 439) and from healthy controls (n = 89). We found that DNase activity was lower than normal in asthma [78.7 relative fluorescence units (RFU)/min vs. 120.4 RFU/min, P < 0.0001]. Compared to patients with asthma with sputum DNase activity in the upper tertile activity levels, those in the lower tertile of sputum DNase activity were characterized clinically by more severe disease and pathologically by airway eosinophilia and airway mucus plugging. Carbamylation of DNase-I, a post-translational modification that can be mediated by eosinophil peroxidase, inactivated DNase-I. In summary, a Taqman probe-based DNase activity assay uncovers low DNase activity in the asthma airway that is associated with more severe disease and airway mucus plugging and may be caused, at least in part, by eosinophil-mediated carbamylation.NEW & NOTEWORTHY We developed a new DNase assay and used it to show that DNase activity is impaired in asthma airways.


Assuntos
Asma , Desoxirribonuclease I , Escarro , Humanos , Asma/metabolismo , Asma/enzimologia , Feminino , Masculino , Escarro/metabolismo , Escarro/enzimologia , Adulto , Pessoa de Meia-Idade , Desoxirribonuclease I/metabolismo , Desoxirribonucleases/metabolismo
13.
Nat Microbiol ; 9(5): 1368-1381, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38622379

RESUMO

Two prokaryotic defence systems, prokaryotic Argonautes (pAgos) and CRISPR-Cas, detect and cleave invader nucleic acids using complementary guides and the nuclease activities of pAgo or Cas proteins. However, not all pAgos are active nucleases. A large clade of short pAgos bind nucleic acid guides but lack nuclease activity, suggesting a different mechanism of action. Here we investigate short pAgos associated with a putative effector nuclease, NbaAgo from Novosphingopyxis baekryungensis and CmeAgo from Cupriavidus metallidurans. We show that these pAgos form a heterodimeric complex with co-encoded effector nucleases (short prokaryotic Argonaute, DNase and RNase associated (SPARDA)). RNA-guided target DNA recognition unleashes the nuclease activity of SPARDA leading to indiscriminate collateral cleavage of DNA and RNA. Activation of SPARDA by plasmids or phages results in degradation of cellular DNA and cell death or dormancy, conferring target-specific population protection and expanding the range of known prokaryotic immune systems.


Assuntos
Proteínas Argonautas , Proteínas de Bactérias , Proteínas Argonautas/metabolismo , Proteínas Argonautas/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Sistemas CRISPR-Cas , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética , Desoxirribonucleases/química , Plasmídeos/genética , Plasmídeos/metabolismo , Bacteriófagos/genética , Bacteriófagos/metabolismo , DNA Bacteriano/metabolismo , DNA Bacteriano/genética , DNA/metabolismo , DNA/genética
14.
Int J Mol Sci ; 25(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38673878

RESUMO

Irritable bowel syndrome (IBS) involves low-grade mucosal inflammation. Among the various approaches capable of managing the symptoms, physical activity is still under investigation. Despite its benefits, it promotes oxidative stress and inflammation. Mitochondria impacts gut disorders by releasing damage-associated molecular patterns, such as cell-free mtDNA (cf-mtDNA), which support inflammation. This study evaluated the effects of a 12-week walking program on the cf-mtDNA and DNase in 26 IBS and 17 non-IBS subjects. Pro- and anti-inflammatory cytokines were evaluated by ELISA. Digital droplet PCR was used to quantify cf-mtDNA; DNase activity was assessed using a single radial enzyme diffusion assay. PCR-RFLP was used to genotype DNASE1 rs1053874 SNP. Significantly lower IL-10 levels were found in IBS than in non-IBS individuals. Exercise reduced cf-mtDNA in non-IBS subjects but not in IBS patients. DNase activity did not correlate with the cf-mtDNA levels in IBS patients post-exercise, indicating imbalanced cf-mtDNA clearance. Different rs1053874 SNP frequencies were not found between groups. The study confirms the positive effects of regular moderate-intensity physical activity in healthy subjects and its role in cf-mtDNA release and clearance. Walking alone might not sufficiently reduce subclinical inflammation in IBS, based on imbalanced pro- and anti-inflammatory molecules. Prolonged programs are necessary to investigate their effects on inflammatory markers in IBS.


Assuntos
Ácidos Nucleicos Livres , DNA Mitocondrial , Síndrome do Intestino Irritável , Caminhada , Humanos , Síndrome do Intestino Irritável/genética , Síndrome do Intestino Irritável/metabolismo , DNA Mitocondrial/genética , Masculino , Feminino , Adulto , Ácidos Nucleicos Livres/genética , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética , Exercício Físico/fisiologia
15.
Methods Mol Biol ; 2760: 95-114, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38468084

RESUMO

We describe a new way to trigger mRNA degradation in Saccharomyces cerevisiae synthetic gene circuits. Our method demands to modify either the 5'- or the 3'-UTR that flanks a target gene with elements from the pre-crRNA of type V Cas12a proteins and expresses a DNase-deficient Cas12a (dCas12a). dCas12a recognizes and cleaves the pre-crRNA motifs on mRNA sequences. Our tool does not require complex engineering operations and permits an efficient control of protein expression via mRNA degradation.


Assuntos
RNA Guia de Sistemas CRISPR-Cas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Genes Sintéticos , Desoxirribonucleases/metabolismo , Estabilidade de RNA , Sistemas CRISPR-Cas
16.
Angew Chem Int Ed Engl ; 63(20): e202403123, 2024 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-38516796

RESUMO

The CRISPR-Cas12a system has emerged as a powerful tool for next-generation nucleic acid-based molecular diagnostics. However, it has long been believed to be effective only on DNA targets. Here, we investigate the intrinsic RNA-enabled trans-cleavage activity of AsCas12a and LbCas12a and discover that they can be directly activated by full-size RNA targets, although LbCas12a exhibits weaker trans-cleavage activity than AsCas12a on both single-stranded DNA and RNA substrates. Remarkably, we find that the RNA-activated Cas12a possesses higher specificity in recognizing mutated target sequences compared to DNA activation. Based on these findings, we develop the "Universal Nuclease for Identification of Virus Empowered by RNA-Sensing" (UNIVERSE) assay for nucleic acid testing. We incorporate a T7 transcription step into this assay, thereby eliminating the requirement for a protospacer adjacent motif (PAM) sequence in the target. Additionally, we successfully detect multiple PAM-less targets in HIV clinical samples that are undetectable by the conventional Cas12a assay based on double-stranded DNA activation, demonstrating unrestricted target selection with the UNIVERSE assay. We further validate the clinical utility of the UNIVERSE assay by testing both HIV RNA and HPV 16 DNA in clinical samples. We envision that the intrinsic RNA targeting capability may bring a paradigm shift in Cas12a-based nucleic acid detection and further enhance the understanding of CRISPR-Cas biochemistry.


Assuntos
Proteínas Associadas a CRISPR , Sistemas CRISPR-Cas , RNA , Humanos , Proteínas Associadas a CRISPR/metabolismo , Proteínas Associadas a CRISPR/genética , Sistemas CRISPR-Cas/genética , Desoxirribonucleases/metabolismo , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/química , RNA/metabolismo , RNA/química , RNA/genética
17.
J Transl Med ; 22(1): 246, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454482

RESUMO

BACKGROUND: Thrombo-inflammation and neutrophil extracellular traps (NETs) are exacerbated in severe cases of COVID-19, potentially contributing to disease exacerbation. However, the mechanisms underpinning this dysregulation remain elusive. We hypothesised that lower DNase activity may be associated with higher NETosis and clinical worsening in patients with COVID-19. METHODS: Biological samples were obtained from hospitalized patients (15 severe, 37 critical at sampling) and 93 non-severe ambulatory cases. Our aims were to compare NET biomarkers, functional DNase levels, and explore mechanisms driving any imbalance concerning disease severity. RESULTS: Functional DNase levels were diminished in the most severe patients, paralleling an imbalance between NET markers and DNase activity. DNase1 antigen levels were higher in ambulatory cases but lower in severe patients. DNase1L3 antigen levels remained consistent across subgroups, not rising alongside NET markers. DNASE1 polymorphisms correlated with reduced DNase1 antigen levels. Moreover, a quantitative deficiency in plasmacytoid dendritic cells (pDCs), which primarily express DNase1L3, was observed in critical patients. Analysis of public single-cell RNAseq data revealed reduced DNase1L3 expression in pDCs from severe COVID-19 patient. CONCLUSION: Severe and critical COVID-19 cases exhibited an imbalance between NET and DNase functional activity and quantity. Early identification of NETosis imbalance could guide targeted therapies against thrombo-inflammation in COVID-19-related sepsis, such as DNase administration, to avert clinical deterioration. TRIAL REGISTRATION: COVERAGE trial (NCT04356495) and COLCOV19-BX study (NCT04332016).


Assuntos
COVID-19 , Armadilhas Extracelulares , Doenças do Sistema Nervoso , Humanos , Armadilhas Extracelulares/metabolismo , Neutrófilos/metabolismo , Desoxirribonucleases/metabolismo , Desoxirribonuclease I/metabolismo , Inflamação/metabolismo
18.
Science ; 383(6687): 1111-1117, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38452081

RESUMO

The extent to which prophage proteins interact with eukaryotic macromolecules is largely unknown. In this work, we show that cytoplasmic incompatibility factor A (CifA) and B (CifB) proteins, encoded by prophage WO of the endosymbiont Wolbachia, alter long noncoding RNA (lncRNA) and DNA during Drosophila sperm development to establish a paternal-effect embryonic lethality known as cytoplasmic incompatibility (CI). CifA is a ribonuclease (RNase) that depletes a spermatocyte lncRNA important for the histone-to-protamine transition of spermiogenesis. Both CifA and CifB are deoxyribonucleases (DNases) that elevate DNA damage in late spermiogenesis. lncRNA knockdown enhances CI, and mutagenesis links lncRNA depletion and subsequent sperm chromatin integrity changes to embryonic DNA damage and CI. Hence, prophage proteins interact with eukaryotic macromolecules during gametogenesis to create a symbiosis that is fundamental to insect evolution and vector control.


Assuntos
Proteínas de Bactérias , Desoxirribonucleases , Drosophila melanogaster , Herança Paterna , Prófagos , RNA Longo não Codificante , Espermatozoides , Proteínas Virais , Wolbachia , Animais , Masculino , Citoplasma/metabolismo , DNA/metabolismo , Prófagos/genética , Prófagos/metabolismo , RNA Longo não Codificante/metabolismo , Espermatozoides/crescimento & desenvolvimento , Espermatozoides/metabolismo , Wolbachia/metabolismo , Wolbachia/virologia , Proteínas Virais/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/microbiologia , Proteínas de Bactérias/metabolismo , Desoxirribonucleases/metabolismo
19.
Biomolecules ; 14(3)2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38540724

RESUMO

In this clinical era of intracytoplasmic sperm injection (ICSI), where a single spermatozoon is chosen for fertilization, the diagnostic functionality of the classical parameters typically associated with fertilization, such as sperm concentration, sperm motility, acrosome integrity, and mitochondria, is perhaps becoming less critical. In contrast, the contribution of sperm DNA quality to our understanding of the impact of male fertility within the context of ICSI is gaining increasing interest and importance. Even with respect to natural conception, high levels of sperm DNA fragmentation (SDF) in the ejaculate can adversely affect reproductive outcomes. However, the precise origin of SDF pathology in sperm cells is often ambiguous and most likely to be multifactorial. Hence, the genetic makeup of an individual, unbalanced REDOX processes, enzymatic activity, environmental and lifestyle factors, and even damage during sperm handling in the laboratory all operate in a unique and often synergistic manner to produce or induce sperm DNA damage. Surprisingly, the contribution of active enzymes as potential agents of SDF has received much less attention and, therefore, is likely to be underrated. This review highlights the roles of different enzymes related to the degradation of sperm DNA as possible effectors of DNA molecules in spermatozoa.


Assuntos
Sêmen , Motilidade dos Espermatozoides , Humanos , Masculino , Fragmentação do DNA , Espermatozoides/metabolismo , DNA/metabolismo , Desoxirribonucleases/metabolismo
20.
BMC Oral Health ; 24(1): 394, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539149

RESUMO

OBJECTIVE: The objective of this study was to assess the characterization of human acellular amniotic membrane (HAAM) using various decellularization methods and their impact on the proliferation and differentiation of human dental pulp stem cells (DPSCs). The goal was to identify scaffold materials that are better suited for pulp regeneration. METHODS: Six different decellularization methods were used to generate the amniotic membranes. The characteristics of these scaffolds were examined through hematoxylin and eosin (H&E) staining, scanning electron microscopy (SEM), and immunohistofluorescence staining (IHF). The DPSCs were isolated, cultured, and their capacity for multidirectional differentiation was verified. The third generation (P3) DPSCs, were then combined with HAAM to form the decellularized amniotic scaffold-dental pulp stem cell complex (HAAM-DPSCs complex). Subsequently, the osteogenic capacity of the HAAM-DPSCs complex was evaluated using CCK8 assay, live-dead cell staining, alizarin red and alkaline phosphatase staining, and real-time quantitative PCR (RT-PCR). RESULTS: Out of the assessed decellularization methods, the freeze-thaw + DNase method and the use of ionic detergent (CHAPS) showed minimal changes in structure after decellularization, making it the most effective method. The HAAM-DPSCs complexes produced using this method demonstrated enhanced biological properties, as indicated by CCK8, alizarin red, alkaline phosphatase staining, and RT-PCR. CONCLUSION: The HAAM prepared using the freeze-thaw + DNase method and CHAPS methods exhibited improved surface characteristics and significantly enhanced the proliferation and differentiation capacity of DPSCs when applied to them. The findings, therefore demonstrate the capacity for enhanced pulp regeneration therapy.


Assuntos
Âmnio , Antraquinonas , Polpa Dentária , Humanos , Âmnio/metabolismo , Células Cultivadas , Fosfatase Alcalina/metabolismo , Células-Tronco/metabolismo , Regeneração , Osteogênese , Diferenciação Celular , Desoxirribonucleases/metabolismo , Proliferação de Células
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