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1.
Gut Pathog ; 15(1): 48, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37848994

RESUMO

BACKGROUND: Zoonotic microorganisms are increasingly impacting human health worldwide. Due to the development of the global population, humans and animals live in shared and progressively crowded ecosystems, which enhances the risk of zoonoses. Although Campylobacter species are among the most important bacterial zoonotic agents worldwide, the molecular mechanisms of many host and pathogen factors involved in colonisation and infection are poorly understood. Campylobacter jejuni colonises the crypts of the human colon and causes acute inflammatory processes. The mucus and associated proteins play a central host-protective role in this process. The aim of this study was to explore the regulation of specific glycosyltransferase genes relevant to differential mucin-type O-glycosylation that could influence host colonisation and infection by C. jejuni. RESULTS: Since microRNAs are known to be important regulators of the mammalian host cell response to bacterial infections, we focussed on the role of miR-125a-5p in C. jejuni infection. Combining in vitro and in vivo approaches, we show that miR-125a-5p regulates the expression of the sialyltransferase ST3GAL1 in an infection-dependent manner. The protein ST3GAL1 shows markedly increased intestinal levels in infected mice, with enhanced distribution in the mucosal epithelial layer in contrast to naïve mice. CONCLUSION: From our previous studies and the data presented here, we conclude that miR-125a-5p and the previously reported miR-615-3p are involved in regulating the glycosylation patterns of relevant host cell response proteins during C. jejuni infection. The miRNA-dependent modulation of mucin-type O-glycosylation could be part of the mucosal immune response, but also a pathogen-driven modification that allows colonisation and infection of the mammalian host.

2.
Insects ; 14(1)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36662005

RESUMO

The western honey bee Apis mellifera is globally distributed due to its beekeeping advantages and plays an important role in the global ecology and economy. In recent decades, several studies have raised concerns about bee decline. Discussed are multiple reasons such as increased pathogen pressure, malnutrition or pesticide use. Insecticides are considered to be one of the major factors. In 2013, the use of three neonicotinoids in the field was prohibited in the EU. Flupyradifurone was introduced as a potential successor; it has a comparable mode of action as the banned neonicotinoids. However, there is a limited number of studies on the effects of sublethal concentrations of flupyradifurone on honey bees. Particularly, the larval physiological response by means of protein expression has not yet been studied. Hence, the larval protein expression was investigated via 2D gel electrophoresis after following a standardised protocol to apply sublethal concentrations of the active substance (flupyradifurone 10 mg/kg diet) to larval food. The treated larvae did not show increased mortality or an aberrant development. Proteome comparisons showed clear differences concerning the larval metabolism, immune response and energy supply. Further field studies are needed to validate the in vitro results at a colony level.

3.
BMC Vet Res ; 18(1): 355, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36138476

RESUMO

BACKGROUND: Circulating microRNAs (miRNAs) are described as promising non-invasive biomarkers for diagnostics and therapeutics. Human studies have shown that haemolysis occurring during blood collection or due to improper sample processing/storage significantly alters the miRNA content in plasma and serum. Nevertheless, no similar research has been performed in dogs so far. We therefore investigated the effects of different degrees of haemolysis on the levels of selected miRNAs in serum and serum-derived extracellular vesicles (EVs) from dogs, by inducing a controlled in vitro haemolysis experiment. RESULTS: The abundance of miR-16, miR-92a, miR-191, miR-451 and miR-486 was significantly sensitive to haemolysis in serum and serum-derived EVs, while other selected miRNAs were not influenced by haemolysis. Furthermore, we found that the abundance of some canine miRNAs differs from data reported in the human system. CONCLUSIONS: Our results describe for the first time the impact of haemolysis on circulating miRNAs not only in whole serum, but also in serum-derived EVs from dogs. Hence, we provide novel data for further analyses in the discovery of canine circulating biomarkers. Our findings suggest that haemolysis should be carefully assessed to assure accuracy when investigating circulating miRNA in serum or plasma-based tests.


Assuntos
MicroRNA Circulante , Doenças do Cão , Vesículas Extracelulares , MicroRNAs , Animais , Biomarcadores , Cães , Hemólise , MicroRNAs/genética
4.
Int J Mol Sci ; 24(1)2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36613799

RESUMO

Honey bees are important managed pollinators that fulfill important ecological and economic functions. In recent decades, the obligate ectoparasite Varroa destructor severely affected the survival of honey bees, as it weakened them by different means. A common treatment against V. destructor is formic acid fumigation, which has been used for decades by beekeepers across the world. This treatment is known to be effective, but many beekeepers report adverse effects of formic acid on bees, which include damage to the brood, worker bee mortality, and queen loss. Little is known about the molecular mechanisms of formic acid detoxification in honey bees. Recently, we reported upregulation of the bee enzyme, 10-formyl-THFDH, under formic acid fumigation. Here, the active site of this enzyme is characterized by an interdisciplinary approach combining homology modeling and protein mutagenesis. In addition, the limitations of the 3D protein structure prediction program AlphaFold2 are shown in regard to docking studies. This study provides a more thorough understanding of the molecular detoxification mechanisms of formic acid in Apis mellifera.


Assuntos
Formiatos , Fumigação , Animais , Abelhas , Domínio Catalítico
5.
Front Insect Sci ; 2: 829869, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38468756

RESUMO

Honeybees are important managed pollinators that perform important ecological and economic functions. In recent decades, the obligate ectoparasite Varroa destructor severely affected survival of honeybees as it either feeds on hemolymph and fat bodies or acts as a vector for viruses. A common treatment against the varroa mite is formic acid, which has been used for many years by beekeepers. This treatment is known to be effective, but the therapeutic index is very narrow. Many beekeepers report negative effects of formic acid on bees, which include damage to brood, worker bee mortality, and queen loss. Little is yet known about the molecular mechanisms of formic acid detoxification in honeybees. Our previous study shows the upregulation of predicted 10-formyl tetrahydrofolate dehydrogenase (10-FTHFDH) transcripts in honeybees exposed to formic acid. Here, the predicted honeybee-specific 10-FTHFDH is recombinantly expressed, and its hydrolase and dehydrogenase activities are investigated. As a result, the enzyme shows similar dehydrogenase activity in comparison to known 10-FTHFDHs. This study provides further knowledge to better understand the detoxification mechanisms of formic acid in Apis mellifera.

6.
Gut Pathog ; 13(1): 42, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183045

RESUMO

BACKGROUND: Campylobacter jejuni (C. jejuni) infections are of increasing importance worldwide. As a typical mucosal pathogen, the interaction of C. jejuni with mucins is a prominent step in the colonisation of mucosal surfaces. Despite recent advances in understanding the interaction between bacterial pathogens and host mucins, the mechanisms of mucin glycosylation during intestinal C. jejuni infection remain largely unclear. This prompted us to identify relevant regulatory networks that are concerted by miRNAs and could play a role in the mucin modification and interaction. RESULTS: We firstly used a human intestinal in vitro model, in which we observed altered transcription of MUC2 and TFF3 upon C. jejuni NCTC 11168 infection. Using a combined approach consisting of in silico analysis together with in vitro expression analysis, we identified the conserved miRNAs miR-125a-5p and miR-615-3p associated with MUC2 and TFF3. Further pathway analyses showed that both miRNAs appear to regulate glycosyltransferases, which are related to the KEGG pathway 'Mucin type O-glycan biosynthesis'. To validate the proposed interactions, we applied an in vivo approach utilising a well-established secondary abiotic IL-10-/- mouse model for infection with C. jejuni 81-176. In colonic tissue samples, we confirmed infection-dependent aberrant transcription of MUC2 and TFF3. Moreover, two predicted glycosyltransferases, the sialyltransferases ST3GAL1 and ST3GAL2, exhibited inversely correlated transcriptional levels compared to the expression of the identified miRNAs miR-125a-5p and miR-615-3p, respectively. In this study, we mainly focused on the interaction between miR-615-3p and ST3GAL2 and were able to demonstrate their molecular interaction using luciferase reporter assays and RNAi. Detection of ST3GAL2 in murine colonic tissue by immunofluorescence demonstrated reduced intensity after C. jejuni 81-176 infection and was thus consistent with the observations made above. CONCLUSIONS: We report here for the first time the regulation of glycosyltransferases by miRNAs during murine infection with C. jejuni 81-176. Our data suggest that mucin type O-glycan biosynthesis is concerted by the interplay of miRNAs and glycosyltransferases, which could determine the shape of intestinal glycosylated proteins during infection.

7.
Sci Rep ; 10(1): 21943, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33318550

RESUMO

Formic acid (FA) has been used for decades to control Varroa destructor, one of the most important parasites of the western honey bee, Apis mellifera. The rather unselective molecular mode of action of FA and its possible effects on honeybees have long been a concern of beekeepers, as it has undesirable side effects that affect the health of bee colonies. This study focuses on short-term transcriptomic changes as analysed by RNAseq in both larval and adult honey bees and in mites after FA treatment under applied conditions. Our study aims to identify those genes in honey bees and varroa mites differentially expressed upon a typical FA hive exposure scenario. Five detoxification-related genes were identified with significantly enhanced and one gene with significantly decreased expression under FA exposure. Regulated genes in our test setting included members of various cytochrome P450 subfamilies, a flavin-dependent monooxygenase and a cytosolic 10-formyltetrahydrofolate dehydrogenase (FDH), known to be involved in formate metabolism in mammals. We were able to detect differences in the regulation of detoxification-associated genes between mites and honey bees as well as between the two different developmental stages of the honey bee. Additionally, we detected repressed regulation of Varroa genes involved in cellular respiration, suggesting mitochondrial dysfunction and supporting the current view on the mode of action of FA-inhibition of oxidative phosphorylation. This study shows distinct cellular effects induced by FA on the global transcriptome of both host and parasite in comparison. Our expression data might help to identify possible differences in the affected metabolic pathways and thus make a first contribution to elucidate the mode of detoxification of FA.


Assuntos
Abelhas , Formiatos/farmacologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Varroidae/metabolismo , Animais , Abelhas/metabolismo , Abelhas/parasitologia
8.
PLoS Biol ; 18(12): e3000982, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33332353

RESUMO

Toll-like receptors (TLRs) play a crucial role in the innate immune response. Although endosomal TLR7 recognizes single-stranded RNAs, their endogenous RNA ligands have not been fully explored. Here, we report 5'-tRNA half molecules as abundant activators of TLR7. Mycobacterial infection and accompanying surface TLR activation up-regulate the expression of 5'-tRNA half molecules in human monocyte-derived macrophages (HMDMs). The abundant accumulation of 5'-tRNA halves also occur in HMDM-secreted extracellular vehicles (EVs); the abundance of EV-5'-tRNAHisGUG half molecules is >200-fold higher than that of the most abundant EV-microRNA (miRNA). Sequence identification of the 5'-tRNA halves using cP-RNA-seq revealed abundant and selective packaging of specific 5'-tRNA half species into EVs. The EV-5'-tRNAHisGUG half was experimentally demonstrated to be delivered into endosomes in recipient cells and to activate endosomal TLR7. Up-regulation of the 5'-tRNA half molecules was also observed in the plasma of patients infected with Mycobacterium tuberculosis. These results unveil a novel tRNA-engaged pathway in the innate immune response and assign the role of "immune activators" to 5'-tRNA half molecules.


Assuntos
Vesículas Extracelulares/genética , RNA de Transferência de Histidina/metabolismo , Receptor 7 Toll-Like/metabolismo , Endossomos/metabolismo , Vesículas Extracelulares/metabolismo , Regulação da Expressão Gênica/genética , Humanos , Imunidade Inata/genética , Imunidade Inata/fisiologia , Macrófagos/metabolismo , RNA de Transferência/metabolismo , RNA de Transferência de Histidina/genética , RNA de Transferência de Histidina/fisiologia , Células THP-1 , Receptor 7 Toll-Like/fisiologia
9.
Pestic Biochem Physiol ; 170: 104703, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980071

RESUMO

For the last decade, scientists have reported a loss of honeybee colonies. Multiple factors like parasites, pathogens and pesticides are dealt as possible drivers of honeybee losses. In particular, insecticides are considered as a major factor of pollinator poisoning. We applied sublethal concentrations of four insecticidal substances to honeybee larval food and analyzed the effects on transcriptome. The aim was to identify candidate genes indicating early negative impacts after application of insecticidal substances. Honeybee larvae were kept in-vitro under hive conditions (34-35 °C) and fed with dimethoate, fenoxycarb, chlorantraniliprole and flupyradifurone in sublethal concentrations between day 3-6 after grafting. Larvae at day 4, 6 and 8 were sampled and their transcriptome analyzed. By use of a RT-qPCR array differences in gene expression of selected gene families (immune system, development detoxification) were measured. Targets mainly involved in development, energy metabolism and the immune system were significantly affected by the insecticidal substances tested, selectively inducing genes of the detoxification system, immune response and nutritional stress.


Assuntos
Inseticidas/farmacologia , Inseticidas/toxicidade , Animais , Abelhas/genética , Dimetoato , Larva/genética , RNA Mensageiro/genética , Transcriptoma
10.
FEBS Open Bio ; 10(5): 802-816, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32133790

RESUMO

The tumour microenvironment comprises a diverse range of cells, including fibroblasts, immune cells and endothelial cells, along with extracellular matrix. In particular, fibroblasts are of significant interest as these cells are reprogrammed during tumorigenesis to become cancer-associated fibroblasts (CAFs), which in turn support cancer cell growth. MicroRNAs (miRNAs) have been shown to be involved in this intercellular crosstalk in humans. To assess whether miRNAs are also involved in the activation of fibroblasts in dogs, we cocultured primary canine skin fibroblasts with the canine mast cell tumour cell line C2 directly or with C2-derived exosomes, and measured differential abundance of selected miRNAs. Expression of the CAF markers alpha-smooth muscle actin (ACTA2) and stanniocalcin 1 confirmed the activation of our fibroblasts after coculture. We show that fibroblasts displayed significant downregulation of miR-27a and let-7 family members. These changes correlated with significant upregulation of predicted target mRNAs. Furthermore, RNA interference knockdown of miR-27a revealed that cyclin G1 (CCNG1) exhibited negative correlation at the mRNA and protein level, suggesting that CCNG1 is a target of miR-27a in canine fibroblasts and involved in their activation. Importantly, miR-27a knockdown itself resulted in fibroblast activation, as demonstrated by the formation of ACTA2 filaments. In addition, interleukin-6 (IL-6) was strongly induced in our fibroblasts when cocultured, indicating potential reciprocal signalling. Taken together, our findings are consistent with canine fibroblasts being reprogrammed into CAFs to further support cancer development and that downregulation of miR-27a may play an important role in the tumour-microenvironment crosstalk.


Assuntos
Fibroblastos Associados a Câncer/metabolismo , Mastócitos/metabolismo , MicroRNAs/genética , Animais , Fibroblastos Associados a Câncer/fisiologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Técnicas de Cocultura , Doenças do Cão/genética , Doenças do Cão/metabolismo , Cães , Células Endoteliais/metabolismo , Exossomos/genética , Exossomos/metabolismo , Fibroblastos/metabolismo , Mastocitoma Cutâneo/genética , Mastocitoma Cutâneo/metabolismo , Mastocitoma Cutâneo/fisiopatologia , MicroRNAs/metabolismo , Transdução de Sinais/genética , Microambiente Tumoral/genética , Microambiente Tumoral/fisiologia
11.
Gut Pathog ; 12: 8, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32064001

RESUMO

BACKGROUND: Campylobacter jejuni (C. jejuni) has been assigned as an important food-borne pathogen for human health but many pathogenicity factors of C. jejuni and human host cell responses related to the infection have not yet been adequately clarified. This study aimed to determine further C. jejuni pathogenicity factors and virulence genes based on a random mutagenesis approach. A transposon mutant library of C. jejuni NCTC 11168 was constructed and the ability of individual mutants to adhere to and invade human intestinal epithelial cells was evaluated compared to the wild type. We identified two mutants of C. jejuni possessing altered phenotypes with transposon insertions in the genes Cj1492c and Cj1507c. Cj1492c is annotated as a two-component sensor and Cj1507c is described as a regulatory protein. However, functions of both mutated genes are not clarified so far. RESULTS: In comparison to the wild type, Cj::1492c and Cj::1507c showed around 70-80% relative motility and Cj::1492c had around 3-times enhanced adhesion and invasion rates whereas Cj::1507c had significantly impaired adhesive and invasive capability. Moreover, Cj::1492c had a longer lag phase and slower growth rate while Cj::1507c showed similar growth compared to the wild type. Between 5 and 24 h post infection, more than 60% of the intracellular wild type C. jejuni were eliminated in HT-29/B6 cells, however, significantly fewer mutants were able to survive intracellularly. Nevertheless, no difference in host cell viability and induction of the pro-inflammatory chemokine IL-8 were determined between both mutants and the wild type. CONCLUSION: We conclude that genes regulated by Cj1507c have an impact on efficient adhesion, invasion and intracellular survival of C. jejuni in HT-29/B6 cells. Furthermore, potential signal sensing by Cj1492c seems to lead to limiting attachment and hence internalisation of C. jejuni. However, as the intracellular survival capacities are reduced, we suggest that signal sensing by Cj1492c impacts several processes related to pathogenicity of C. jejuni.

12.
Sci Rep ; 9(1): 18915, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831783

RESUMO

In a recent one-year feeding study, we observed no adverse effects on tissue level in organs of rats fed with the genetically-modified maize MON810. Here, we assessed RNA expression levels of 86 key genes of the apoptosis-, NF-кB-, DNA-damage response (DDR)-, and unfolded-protein response (UPR) pathways by RT-qPCR in the rat liver. Male and female rats were fed either with 33% MON810 (GMO), isogenic- (ISO), or conventional maize (CONV) and RNAs were quantified from eight rats from each of the six feeding groups. Only Birc2 transcript showed a significant (p ≤ 0.05) consistent difference of ≥1.5-fold between the GMO and ISO groups in both sexes. Unsupervised cluster analysis showed a strong separation of male and female rats, but no clustering of the feeding groups. Individual analysis of the pathways did not show any clustering of the male or female feeding groups either, though transcript levels of UPR pathway-associated genes caused some clustering of the male GMO and CONV feeding group samples. These differences were not seen between the GMO and ISO control or within the female cohort. Our data therefore does not support an adverse effect on rat liver RNA expression through the long-term feeding of MON810 compared to isogenic control maize.


Assuntos
Ração Animal , Alimentos Geneticamente Modificados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Fígado/metabolismo , Plantas Geneticamente Modificadas , Zea mays , Animais , Feminino , Masculino , Ratos
13.
Microorganisms ; 7(3)2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30818784

RESUMO

Pathogenic mycobacteria are able to persist intracellularly in macrophages, whereas non-pathogenic mycobacteria are effectively combated and eliminated after their phagocytosis. It is known that TGF-ß plays an important role in this context. Infection with pathogenic mycobacteria such as Mycobacterium tuberculosis or M. avium leads to production of active TGF-ß, which blocks the ability of IFN-γ and TNF-α to inhibit intracellular replication. On the other hand, it is known that the long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) is involved in the regulation of TGF-ß. In this study, we show how the infection of THP-1-derived human macrophages with the saprophytic M. smegmatis but not with the facultatively pathogenic M. avium subsp. hominissuis leads to increased MEG3 expression. This is associated with the downregulation of DNA methyltransferases (DNMT) 1 and 3b, which are known to regulate MEG3 expression via promoter hypermethylation. Consequently, we observe a significant downregulation of TGF-ß in M. smegmatis-infected macrophages but not in M. avium subsp. hominissuis pointing to lncRNAs as novel mediators of host cell response during mycobacterial infections.

14.
Sci Rep ; 9(1): 1571, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733564

RESUMO

Paratuberculosis is a major disease in cattle that severely affects animal welfare and causes huge economic losses worldwide. Development of alternative diagnostic methods is of urgent need to control the disease. Recent studies suggest that long non-coding RNAs (lncRNAs) play a crucial role in regulating immune function and may confer valuable information about the disease. However, their role has not yet been investigated in cattle with respect to infection towards Paratuberculosis. Therefore, we investigated the alteration in genomic expression profiles of mRNA and lncRNA in bovine macrophages in response to Paratuberculosis infection using RNA-Seq. We identified 397 potentially novel lncRNA candidates in macrophages of which 38 were differentially regulated by the infection. A total of 820 coding genes were also significantly altered by the infection. Co-expression analysis of lncRNAs and their neighbouring coding genes suggest regulatory functions of lncRNAs in pathways related to immune response. For example, this included protein coding genes such as TNIP3, TNFAIP3 and NF-κB2 that play a role in NF-κB2 signalling, a pathway associated with immune response. This study advances our understanding of lncRNA roles during Paratuberculosis infection.


Assuntos
Doenças dos Bovinos/genética , Doenças dos Bovinos/microbiologia , Macrófagos/metabolismo , Mycobacterium avium subsp. paratuberculosis/fisiologia , Paratuberculose/genética , Paratuberculose/microbiologia , RNA Longo não Codificante , RNA Mensageiro , Animais , Bovinos , Doenças dos Bovinos/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Genômica/métodos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Macrófagos/imunologia , Paratuberculose/imunologia , Interferência de RNA , Reprodutibilidade dos Testes , Transcrição Gênica , Transcriptoma
15.
Biochem Biophys Res Commun ; 508(3): 832-837, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30528739

RESUMO

The hedgehog signaling pathway is a crucial regulator of the postnatal intestinal development. Regulation of hedgehog expression itself is poorly understood. MicroRNAs were demonstrated to control differentiation and proliferation in postnatal intestinal development. This study identifies members of the miR-15 family to regulate the expression of key hedgehog factors employing in silico and in vitro experiments. Physiological relevance is demonstrated by incorporation of in vivo expression data from the ileum and colon from 7 to 56 days old piglets. Results presented in this study improve the understanding of the complex regulation of hedgehog signaling during intestinal development and disease.


Assuntos
Proteínas Hedgehog/genética , Intestinos/crescimento & desenvolvimento , MicroRNAs/metabolismo , Animais , Linhagem Celular Tumoral , Colo/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteínas Hedgehog/metabolismo , Humanos , Transdução de Sinais/genética , Suínos
16.
Artigo em Inglês | MEDLINE | ID: mdl-28401065

RESUMO

Bacterial pathogens have coevolved with their hosts and acquired strategies to circumvent defense mechanisms of host cells. It was shown that bacteria interfere with the expression of mammalian microRNAs to modify immune signaling, autophagy, or the apoptotic machinery. Recently, a new class of regulatory RNAs, long non-coding RNAs (lncRNAs), was reported to have a pivotal role in the regulation of eukaryotic gene expression. A growing body of literature reports on specific involvement of lncRNAs in the host cell response toward bacterial infections. This mini review summarizes recent data that focuses on lncRNA function in host cells during bacterial infection and provides a perspective where future research in this regard may be going.


Assuntos
Bactérias/patogenicidade , Infecções Bacterianas/imunologia , Interações Hospedeiro-Patógeno/imunologia , RNA Longo não Codificante/fisiologia , Animais , Apoptose , Autofagia , Bactérias/genética , Infecções Bacterianas/metabolismo , Infecções Bacterianas/microbiologia , Regulação da Expressão Gênica , Humanos , Imunidade , MicroRNAs/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/imunologia , Transdução de Sinais
18.
Cell Death Discov ; 3: 16106, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28149533

RESUMO

Tumour necrosis factor-α (TNF-α) is a double-edged cytokine associated with pathogenesis of inflammatory-related cancers being also able to induce cancer cell death. In the process of tumour development or metastasis, cancer cells can become resistant to TNF-α. In trefoil factor 3 (TFF3) overexpressing colorectal adenocarcinoma cells (HT-29/B6), we observed enhanced resistance against TNF-α/interferon gamma-induced apoptosis. TFF3 is a secreted small peptide that supports intestinal tissue repair but is also involved in intestinal tumour progression and scattering. We hypothesised that TFF3 rescues intestinal epithelial cancer cells from TNF-α-induced apoptosis by involving regulatory RNA networks. In silico-based expression analysis revealed TFF3-mediated regulation of selected microRNAs as well as long non-coding RNAs (lncRNAs), whereas miR-491-5p was identified to target the lncRNA 'psoriasis susceptibility-related RNA gene induced by stress' (PRINS). RNA interference-based gain- and loss-of-function experiments examined miR-491-PRINS axis to exert the TFF3-mediated phenotype. Chemical inhibition of selected pathways showed that phosphatidylinositol 3-kinase/AKT accounts for TFF3-mediated downregulation of miR-491-5p and accumulation of PRINS. Moreover, we showed that PRINS colocalises with PMAIP1 (NOXA) in nuclei of HT-29/B6 possessing inhibitory effects. Immunoprecipitation experiments proved molecular interaction of PMAIP1 with PRINS. Our study provides an insight into RNA regulatory networks that determine resistance of colorectal cancer cells to apoptosis.

19.
Eur J Microbiol Immunol (Bp) ; 6(2): 99-108, 2016 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-27429792

RESUMO

The role of microRNAs (miRNAs) in infectious diseases is becoming more and more apparent, and the use of miRNAs as a diagnostic tool and their therapeutic application has become the major focus of investigation. The aim of this study was to identify miRNAs involved in the immune signaling of macrophages in response to Arcobacter (A.) butzleri infection, an emerging foodborne pathogen causing gastroenteritis. Therefore, primary human macrophages were isolated and infected, and miRNA expression was studied by means of RNAseq. Analysis of the data revealed the expression of several miRNAs, which were previously associated with bacterial infections such as miR-155, miR-125, and miR-212. They were shown to play a key role in Toll-like receptor signaling where they act as fine-tuners to establish a balanced immune response. In addition, miRNAs which have yet not been identified during bacterial infections such as miR-3613, miR-2116, miR-671, miR-30d, and miR-629 were differentially regulated in A. butzleri-infected cells. Targets of these miRNAs accumulated in pathways such as apoptosis and endocytosis - processes that might be involved in A. butzleri pathogenesis. Our study contributes new findings about the interaction of A. butzleri with human innate immune cells helping to understand underlying regulatory mechanisms in macrophages during infection.

20.
Artigo em Inglês | MEDLINE | ID: mdl-27014637

RESUMO

Main survival mechanism of pathogenic mycobacteria is to escape inimical phagolysosomal environment inside the macrophages. Many efforts have been made to unravel the molecular mechanisms behind this process. However, little is known about the involvement of microRNAs (miRNAs) in the regulation of phagolysosomal biosynthesis and maturation. Based on a bottom up approach, we searched for miRNAs that were involved in phagolysosomal processing events in the course of mycobacterial infection of macrophages. After infecting THP-1 derived macrophages with viable and heat killed Mycobacterium bovis BCG (BCG), early time points were identified after co-localization studies of the phagosomal marker protein LAMP1 and BCG. Differences in LAMP1 localization on the phagosomes of both groups were observed at 30 min and 4 h. After in silico based pre-selection of miRNAs, expression analysis at the identified time points revealed down-regulation of three miRNAs: miR-3619-5p, miR-637, and miR-324-3p. Consequently, most likely targets were predicted that were supposed to be mutually regulated by these three studied miRNAs. The lysosomal cysteine protease Cathepsin S (CTSS) and Rab11 family-interacting protein 4 (RAB11FIP4) were up-regulated and were considered to be connected to lysosomal trafficking and autophagy. Interaction studies verified the regulation of CTSS by miR-3619-5p. Down-regulation of CTSS by ectopic miR-3619-5p as well as its specific knockdown by siRNA affected the process of autophagy in THP-1 derived macrophages.


Assuntos
Autofagia/genética , Catepsinas/metabolismo , Macrófagos/microbiologia , MicroRNAs/genética , Mycobacterium bovis/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Células HeLa , Humanos , Proteína 1 de Membrana Associada ao Lisossomo/metabolismo , Proteínas de Membrana/metabolismo , Fagossomos/metabolismo , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética
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