RESUMO
The RNA-binding protein DEAD-box protein 5 (DDX5) is a polyfunctional regulator of gene expression, but its role in CD8+ T cell biology has not been extensively investigated. In this study, we demonstrate that deletion of DDX5 in murine CD8+ T cells reduced the differentiation of terminal effector, effector memory T, and terminal effector memory cells while increasing the generation of central memory T cells, whereas forced expression of DDX5 elicited the opposite phenotype. DDX5-deficient CD8+ T cells exhibited increased expression of genes that promote central memory T cell differentiation, including Tcf7 and Eomes. Taken together, these findings reveal a role for DDX5 in regulating the differentiation of effector and memory CD8+ T cell subsets in response to microbial infection.
Assuntos
Linfócitos T CD8-Positivos , Subpopulações de Linfócitos T , Animais , Camundongos , Diferenciação Celular , Memória Imunológica , Ativação Linfocitária , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismoRESUMO
OBJECTIVE: Tuft cells residing in the intestinal epithelium have diverse functions. In the small intestine, they provide protection against inflammation, combat against helminth and protist infections, and serve as entry portals for enteroviruses. In the colon, they had been implicated in tumourigenesis. Commitment of intestinal progenitor cells to the tuft cell lineage requires Rho GTPase Cell Division Cycle 42 (CDC42), a Rho GTPase that acts downstream of the epidermal growth factor receptor and wingless-related integration site signalling cascades, and the master transcription factor POU class 2 homeobox 3 (POU2F3). This study investigates how this pathway is regulated by the DEAD box containing RNA binding protein DDX5 in vivo. DESIGN: We assessed the role of DDX5 in tuft cell specification and function in control and epithelial cell-specific Ddx5 knockout mice (DDX5ΔIEC) using transcriptomic approaches. RESULTS: DDX5ΔIEC mice harboured a loss of intestinal tuft cell populations, modified microbial repertoire, and altered susceptibilities to ileal inflammation and colonic tumourigenesis. Mechanistically, DDX5 promotes CDC42 protein synthesis through a post-transcriptional mechanism to license tuft cell specification. Importantly, the DDX5-CDC42 axis is parallel but distinct from the known interleukin-13 circuit implicated in tuft cell hyperplasia, and both pathways augment Pou2f3 expression in secretory lineage progenitors. In mature tuft cells, DDX5 not only promotes integrin signalling and microbial responses, it also represses gene programmes involved in membrane transport and lipid metabolism. CONCLUSION: RNA binding protein DDX5 directs tuft cell specification and function to regulate microbial repertoire and disease susceptibility in the intestine.
Assuntos
RNA Helicases DEAD-box/metabolismo , Mucosa Intestinal , Animais , Carcinogênese/metabolismo , RNA Helicases DEAD-box/genética , Suscetibilidade a Doenças , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Proteínas de Ligação a RNA/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
Peripheral nerve injury elicits spinal microgliosis, contributing to neuropathic pain. The aurora kinases A (AURKA), B (AURKB), and C (AURKC) are potential therapeutic targets in proliferating cells. However, their role has not been clarified in microglia. The aim of this study was to examine the regulation of aurora kinases and their roles and druggability in spinal microgliosis and neuropathic pain. Sprague-Dawley rats received chronic constriction injury (CCI). Gene expression of aurora kinases A-C was evaluated by quantitative RT-PCR and western blot, respectively, in spinal cords at 1, 3, 7, and 14 days after CCI. AURKB gene and protein expression was up-regulated concomitantly with the development of spinal microgliosis and neuropathic pain. Using lentiviral over-expression and adeno-associated viral knockdown approaches, the function of AURKB was further investigated by western blot, immunohistochemistry, RNA sequencing, and pain behavior tests. We found that AURKB over-expression in naive rats caused spinal microgliosis and pain hypersensitivity, whereas AURKB knockdown reduced microgliosis and alleviated CCI-induced neuropathic pain. Accordingly, RNA sequencing data revealed down-regulation of genes critically involved in signaling pathways associated with spinal microgliosis and neuropathic pain after AURKB knockdown in CCI rats. To examine its therapeutic potential for treatment of neuropathic pain, animals were treated intrathecally with the pharmacological AURKB inhibitor AZD1152-HQPA resulting in the alleviation of CCI-induced pain. Taken together, our findings indicated that AURKB plays a critical role in spinal microgliosis and neuropathic pain. Targeting AURKB may be an efficient method for treatment of neuropathic pain subsequent to peripheral nerve injury.
Assuntos
Aurora Quinase B/antagonistas & inibidores , Microglia/fisiologia , Neuralgia/terapia , Traumatismos dos Nervos Periféricos/fisiopatologia , Animais , Aurora Quinase B/genética , Aurora Quinase B/fisiologia , Modelos Animais de Doenças , Regulação para Baixo , Inibidores Enzimáticos/uso terapêutico , Expressão Gênica , Técnicas de Silenciamento de Genes , Masculino , Microglia/enzimologia , Microglia/patologia , Neuralgia/enzimologia , Traumatismos dos Nervos Periféricos/enzimologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/enzimologia , Medula Espinal/patologiaRESUMO
Despite advanced clinical treatments, mortality in patients with metastatic colorectal cancer (CRC) remains high. Three critical determinants in CRC progression include the epithelial proliferation checkpoints, epithelial-to-mesenchymal transition (EMT) and inflammatory cytokines in the tumour microenvironment. Genes involved in these three processes are regulated at the transcriptional and post-transcriptional level. Recent studies revealed previously unappreciated roles of non-coding ribonucleic acids (ncRNAs) in modulating the proliferation checkpoints, EMT, and inflammatory gene expression in CRC. In this review, we will discuss the mechanisms underlying the roles of ncRNAs in CRC as well as examine future perspectives in this field. Better understanding of ncRNA biology will provide novel targets for future therapeutic development.
Assuntos
Neoplasias Colorretais/genética , Regulação da Expressão Gênica , Inflamação/genética , RNA não Traduzido/genética , Animais , Biomarcadores , Biomarcadores Tumorais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Inflamação/metabolismo , Inflamação/patologia , Mediadores da Inflamação/metabolismo , MicroRNAs/genética , RNA Longo não Codificante/genéticaRESUMO
Gene transcription regulation is critical for the development of spinal microgliosis and neuropathic pain after peripheral nerve injury. Using a model of chronic constriction injury (CCI) of the sciatic nerve, this study characterized the role of SET domain containing lysine methyltransferase 7 (SETD7) which monomethylates histone H3 lysine 4 (H3K4me1), a marker for active gene transcription. SETD7 protein expression in the spinal dorsal horn ipsilateral to nerve lesion was increased from one day to 14â¯days after CCI, concomitantly with the expression of inflammatory genes, Ccl2, Il-6 and Il-1ß. The CCI-induced SETD7 expression was predominantly localized to microglia, as demonstrated by immunohistochemistry and western blot from magnetic activated cell sorted spinal microglia. SETD7 knockdown by intrathecal lentivirus shRNA delivery prior to CCI prevented spinal microgliosis and neuropathic pain, whereas lentiviral SETD7 transduction exacerbated these symptoms. In addition, SETD7 regulated H3K4me1 level and expression of inflammatory mediators both in CCI rats and in the HAPI rat microglia cell line. Accordingly, PFI-2, a specific inhibitor of SETD7 monomethylation activity, suppressed the lipopolysaccharides-induced amoeboid morphology of primary microglia and the expression of inflammatory genes, Ccl2, Il-6 and Il-1ß. Moreover, intrathecal administration of PFI-2 alleviated CCI-induced neuropathic pain. However, this effect was observed in male but not in female rats. These results demonstrate a critical role of SETD7 in the development of spinal microgliosis and neuropathic pain subsequently to peripheral nerve injury. The pharmacological approach further suggests that SETD7 is a new target for the treatment of neuropathic pain. The underlying mechanisms may involve H3K4me1-dependent regulation of inflammatory gene expression in microglia.
Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Microglia/metabolismo , Neuralgia/metabolismo , Animais , Feminino , Gânglios Espinais/metabolismo , Hiperalgesia/metabolismo , Masculino , Traumatismos dos Nervos Periféricos/metabolismo , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões , Medula Espinal/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Coluna Vertebral/metabolismoRESUMO
UNLABELLED: Sirtuin 6 (SIRT6) is a member of the sirtuin family of NAD+-dependent deacetylases. Genetic deletion of Sirt6 in mice results in a severe degenerative phenotype with impaired liver function and premature death. The role of SIRT6 in development and progression of hepatocellular carcinoma is currently unknown. We first investigated SIRT6 expression in 153 primary human liver cancers and in normal and cirrhotic livers using microarray analysis. SIRT6 was significantly down-regulated in both cirrhotic livers and cancer. A Sirt6 knockout (KO) gene expression signature was generated from primary hepatoctyes isolated from 3-week-old Sirt6-deficient animals. Sirt6-deficient hepatocytes showed up-regulation of established hepatocellular carcinoma (HCC) biomarkers alpha-fetoprotein (Afp), insulin-like growth factor 2 (Igf2), H19, and glypican-3. Furthermore, decreased SIRT6 expression was observed in hepatoma cell lines that are known to be apoptosis-insensitive. Re-expression of SIRT6 in HepG2 cells increased apoptosis sensitivity to CD95-stimulation or chemotherapy treatment. Loss of Sirt6 was characterized by oncogenic changes, such as global hypomethylation, as well as metabolic changes, such as hypoglycemia and increased fat deposition. The hepatocyte-specific Sirt6-KO signature had a prognostic impact and was enriched in patients with poorly differentiated tumors with high AFP levels as well as recurrent disease. Finally, we demonstrated that the Sirt6-KO signature possessed a predictive value for tumors other than HCC (e.g., breast and lung cancer). CONCLUSION: Loss of SIRT6 induces epigenetic changes that may be relevant to chronic liver disease and HCC development. Down-regulation of SIRT6 and genes dysregulated by loss of SIRT6 possess oncogenic effects in hepatocarcinogenesis. Our data demonstrate that deficiency in one epigenetic regulator predisposes a tumorigenic phenotype that ultimately has relevance for outcome of HCC and other cancer patients.
Assuntos
Carcinoma Hepatocelular/fisiopatologia , Epigênese Genética/fisiologia , Neoplasias Hepáticas/fisiopatologia , Sirtuínas/genética , Sirtuínas/fisiologia , Idoso , Idoso de 80 Anos ou mais , Animais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Células Cultivadas , Progressão da Doença , Regulação para Baixo/fisiologia , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Estresse Oxidativo/fisiologia , Prognóstico , Transdução de Sinais/fisiologia , Taxa de SobrevidaRESUMO
Astrocyte swelling is implicated in various neurological disorders. However, whether astrocyte swelling contributes to neuropathic pain remains elusive. This study elucidates the pivotal role of the nuclear factor of activated T-cells 5 (NFAT5) emerges as a master regulator of astrocyte swelling in the spinal dorsal horn (SDH) during neuropathic pain. Despite the ubiquitous expression of NFAT5 protein in SDH cell types, it selectively induces swelling specifically in astrocytes, not in microglia. Mechanistically, NFAT5 directly controls the expression of the water channel aquaporin-4 (AQP4), a key regulator exclusive to astrocytes. Additionally, aurora kinase B (AURKB) orchestrates NFAT5 phosphorylation, enhancing its protein stability and nuclear translocation, thereby regulating AQP4 expression. The findings establish NFAT5 as a crucial regulator for neuropathic pain through the modulation of astrocyte swelling. The AURKB-NFAT5-AQP4 pathway in astrocytes emerges as a potential therapeutic target to combat neuropathic pain.
Assuntos
Astrócitos , Neuralgia , Humanos , Astrócitos/metabolismo , Microglia/metabolismo , Fosforilação , Neuralgia/metabolismo , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND AND AIMS: Gloxinia (Sinningia speciosa) is a popular commercial plant for its attractive and colourful flowers. However, the genetic mechanism of flowering time regulation in gloxinia is largely unknown. Recent studies on model plants have elucidated that miR159 acts as a negative regulator of floral transition in short-day photoperiods. The aim of this study was to investigate whether genetic modification of miR159 expression can offer an effective approach for regulation of flowering characteristics in gloxinia. METHODS: Transgenic gloxinia plants were generated that over-express or suppress miR159 by means an efficient Agrobacterium-mediated transformation system in order to study the effect of miR159 on flowering time. In addition, the full-length cDNA of gloxinia GAMYB (SsGAMYB) was also cloned, and was verified to be a target of miR159 by modified RNA ligase-mediated 5' rapid amplification of cDNA ends. KEY RESULTS: Transgenic gloxinia plants that over-express or suppress miR159 exhibited significantly late or early flowering, respectively. During flower development, the expression level of miR159 was negatively correlated with SsGAMYB in gloxinia. MiR159-mediated SsGAMYB expression affected the expression levels of SsLEAFY (SsLFY) and three MADS-box genes (SsAP1, SsAP3 and SsAG), which regulated floral transition downstream of GAMYB. In addition, suppression of miR159 caused a conversion of petals and sepals in a few transgenic plants. CONCLUSIONS: miR159-regulated GAMYB expression is an effective pathway of flowering time control in gloxinia. Transgenic manipulation of miR159 can be used as an applicable strategy to regulate flowering time in commercial ornamental plants.
Assuntos
Arabidopsis/genética , Flores/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Lamiaceae/genética , Lamiaceae/fisiologia , MicroRNAs/genética , Sequência de Bases , Flores/anatomia & histologia , Genes de Plantas/genética , MicroRNAs/metabolismo , Dados de Sequência Molecular , Organogênese/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Alinhamento de Sequência , Análise de Sequência de Proteína , Fatores de TempoRESUMO
The long non-coding RNA (lncRNA) Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) maintains the integrity of the intestinal epithelial barrier and regulates local inflammation. However, its influences on intestinal microbial communities and tissue susceptibility to cancer development remain unexplored. Here, we report that MALAT1 regulates host anti-microbial response gene expression and the composition of mucosal-associated microbial communities in a region-specific manner. In the APC mutant mouse model of intestine tumorigenesis, knocking out MALAT1 results in higher polyp counts in the small intestine and colon. Interestingly, intestine polyps that developed in the absence of MALAT1 were smaller in size. These findings highlight the unexpected bivalent role of MALAT1 in restricting and promoting cancer progression at different disease stages. Among the 30 MALAT1-targets shared by both the small intestine and colon, ZNF638 and SENP8 levels are predictive of colon adenoma patient overall survival and disease-free survival. Genomic assays further revealed that MALAT1 modulates intestinal target expression and splicing through both direct and indirect mechanisms. This study expands the role of lncRNAs in regulating intestine homeostasis, microbial communities, and cancer pathogenesis.
RESUMO
Retinoid-related orphan receptor (RAR) gamma (RORγt)-expressing regulatory T cells (RORγt+ Tregs) play pivotal roles in preventing T cell hyperactivation and maintaining tissue homeostasis, in part by secreting the anti-inflammation cytokine interleukin-10 (IL-10). Here, we report that hypoxia-induced factor 1α (HIF1α) is the master transcription factor for Il10 in RORγt+ Tregs. This critical anti-inflammatory pathway is negatively regulated by an RNA binding protein DEAD box helicase 5 (DDX5). As a transcriptional corepressor, DDX5 restricts the expression of HIF1α and its downstream target gene Il10 in RORγt+ Tregs. T cell-specific Ddx5 knockout (DDX5ΔT) mice have augmented RORγt+ Treg suppressor activities and are better protected from intestinal inflammation. Genetic ablation or pharmacologic inhibition of HIF1α restores enteropathy susceptibility in DDX5ΔT mice. The DDX5-HIF1α-IL-10 pathway is conserved in mice and humans. These findings reveal potential therapeutic targets for intestinal inflammatory diseases.
Assuntos
Interleucina-10 , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Humanos , Camundongos , Animais , Interleucina-10/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Regulação da Expressão Gênica , Fatores de Transcrição/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Ligação ProteicaRESUMO
PRMT5 is a type II arginine methyltransferase abundantly expressed in the colonic epithelium. It is up-regulated in inflammatory bowel disease and colorectal cancer. However, its role in mucosal defense against enteric infection has not been studied. Here, we report that Prmt5 in the murine colon is up-regulated in response to Citrobacter rodentium infection. Pathogen clearance in mice with haploinsufficient expression of Prmt5 is significantly delayed compared with wildtype littermate controls. Transcriptomic analyses further reveal that PRMT5 regulates the expression of canonical crypt goblet cell genes involved in mucus production, assembly, and anti-microbial responses via methyltransferase activity-dependent and -independent mechanisms. Together, these findings uncover PRMT5 as a novel regulator of mucosal defense and a potential therapeutic target for treating intestinal diseases.
Assuntos
Infecções por Enterobacteriaceae , Intestinos , Animais , Camundongos , Peptídeos e Proteínas de Sinalização Intracelular , Proteína-Arginina N-Metiltransferases/genética , Colo , Infecções por Enterobacteriaceae/genéticaRESUMO
Alcohol-associated liver disease is accompanied by intestinal mycobiome dysbiosis, yet the impacts on liver disease are unclear. We demonstrate that Candida albicans-specific T helper 17 (Th17) cells are increased in circulation and present in the liver of patients with alcohol-associated liver disease. Chronic ethanol administration in mice causes migration of Candida albicans (C. albicans)-reactive Th17 cells from the intestine to the liver. The antifungal agent nystatin decreased C. albicans-specific Th17 cells in the liver and reduced ethanol-induced liver disease in mice. Transgenic mice expressing T cell receptors (TCRs) reactive to Candida antigens developed more severe ethanol-induced liver disease than transgene-negative littermates. Adoptively transferring Candida-specific TCR transgenic T cells or polyclonal C. albicans-primed T cells exacerbated ethanol-induced liver disease in wild-type mice. Interleukin-17 (IL-17) receptor A signaling in Kupffer cells was required for the effects of polyclonal C. albicans-primed T cells. Our findings indicate that ethanol increases C. albicans-specific Th17 cells, which contribute to alcohol-associated liver disease.
Assuntos
Candida albicans , Células Th17 , Camundongos , Animais , Candida , Camundongos Transgênicos , Etanol/toxicidadeRESUMO
⢠MicroRNA (miRNA)-mediated regulation of auxin signaling components plays a critical role in plant development. miRNA expression and functional diversity contribute to the complexity of regulatory networks of miRNA/target modules. ⢠This study functionally characterizes two members of the rice (Oryza sativa) miR393 family and their target genes, OsTIR1 and OsAFB2 (AUXIN SIGNALING F-BOX), the two closest homologs of Arabidopsis TRANSPORT INHIBITOR RESPONSE 1 (TIR1). ⢠We found that the miR393 family members possess distinctive expression patterns, with miR393a expressed mainly in the crown and lateral root primordia, as well as the coleoptile tip, and miR393b expressed in the shoot apical meristem. Transgenic plants overexpressing miR393a/b displayed a severe phenotype with hallmarks of altered auxin signaling, mainly including enlarged flag leaf inclination and altered primary and crown root growth. Furthermore, OsAFB2- and OsTIR1-suppressed lines exhibited increased inclination of flag leaves at the booting stage, resembling miR393-overexpressing plants. Moreover, yeast two-hybrid and bimolecular fluorescence complementation assays showed that OsTIR1 and OsAFB2 interact with OsIAA1. ⢠Expression diversification of miRNA393 implies the potential role of miRNA regulation during species evolution. The conserved mechanisms of the miR393/target module indicate the fundamental importance of the miR393-mediated regulation of auxin signal transduction in rice.
Assuntos
MicroRNAs/genética , Oryza/crescimento & desenvolvimento , Oryza/genética , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Ácido 2,4-Diclorofenoxiacético/toxicidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Genes de Plantas/genética , Resistência a Herbicidas/genética , MicroRNAs/metabolismo , Oryza/anatomia & histologia , Oryza/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimentoRESUMO
MicroRNA*s are about 22nt noncoding RNAs, which are processed from precursors with a characteristic hairpin secondary structure in the biogenesis of microRNAs. Recently, miRNA* strands were shown to mediate post-transcriptional regulatory networks, rather than serve merely as non-functional by-product in general view. Unlike miRNAs bound to AGO1, miRNA* strands are bound to AGO2 to form RISC duplex to mediate RNAi, which is similar to siRNA. This paper mainly reviewed the recent research progresses on miRNA*, such as the biosynthesis, biological characteristics, and functions.
Assuntos
MicroRNAs/fisiologia , Animais , Humanos , Interferência de RNARESUMO
This protocol describes an ex vivo cell culture system for simultaneously generating a mixture of CD4+ T helper lineages, including T helper 17 (Th17), RORγt+ Treg, and conventional Treg (cTreg), in proportions representative of those found in mucosal tissues in vivo. When combined with a co-culture approach, this system allows a more rapid assessment of a candidate molecule's T cell-intrinsic and -extrinsic functions over the traditional bone marrow chimera and co-transfer approaches. For complete details on the use and execution of this protocol, please refer to Ma et al. (2022).
Assuntos
Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Linfócitos T Reguladores , Animais , Técnicas de Cocultura , Ativação Linfocitária , CamundongosRESUMO
RAR-related orphan receptor-γ (RORγt) is an essential transcription factor for thymic T cell development, secondary lymphoid tissue organogenesis, and peripheral immune cell differentiation. Serine 182 phosphorylation is a major post-translational modification (PTM) on RORγt. However, the in vivo contribution of this PTM in health and disease settings is unclear. We report that this PTM is not involved in thymic T cell development and effector T cell differentiation. Instead, it is a critical regulator of inflammation downstream of IL-1ß signaling and extracellular signal regulated kinases (ERKs) activation. ERKs phosphorylation of serine 182 on RORγt serves to simultaneously restrict Th17 hyperactivation and promote anti-inflammatory cytokine IL-10 production in RORγt+ Treg cells. Phospho-null RORγtS182A knockin mice experience exacerbated inflammation in models of colitis and experimental autoimmune encephalomyelitis (EAE). In summary, the IL-1ß-ERK-RORγtS182 circuit protects against T cell-mediated inflammation and provides potential therapeutic targets to combat autoimmune diseases.
Assuntos
Encefalomielite Autoimune Experimental , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Animais , Diferenciação Celular , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Fosforilação , Células Th17RESUMO
During an immune response to microbial infection, CD8+ T cells give rise to short-lived effector cells and memory cells that provide sustained protection. Although the transcriptional programs regulating CD8+ T cell differentiation have been extensively characterized, the role of long noncoding RNAs (lncRNAs) in this process remains poorly understood. Using a functional genetic knockdown screen, we identified the lncRNA Malat1 as a regulator of terminal effector cells and the terminal effector memory (t-TEM) circulating memory subset. Evaluation of chromatin-enriched lncRNAs revealed that Malat1 grouped with trans lncRNAs that exhibit increased RNA interactions at gene promoters and gene bodies. Moreover, we observed that Malat1 was associated with increased H3K27me3 deposition at a number of memory cell-associated genes through a direct interaction with Ezh2, thereby promoting terminal effector and t-TEM cell differentiation. Our findings suggest an important functional role of Malat1 in regulating CD8+ T cell differentiation and broaden the knowledge base of lncRNAs in CD8+ T cell biology.
Assuntos
RNA Longo não Codificante , Linfócitos T CD8-Positivos , Diferenciação Celular/genética , Repressão Epigenética , Ativação Linfocitária , RNA Longo não Codificante/genéticaRESUMO
We investigated the microRNA172 (miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, manipulation of which could be economically beneficial. Transgenic gloxinia plants, in which miR172 was either overexpressed or suppressed, were generated using Agrobacterium-mediated transformation. They were used to study the effect of altering the expression of this miRNA on time of flowering and to identify its mRNA target. Early or late flowering was observed in transgenic plants in which miR172 was overexpressed or suppressed, respectively. A full-length complementary DNA (cDNA) of gloxinia (Sinningia speciosa) APETALA2-like (SsAP2-like) was identified as a target of miR172. The altered expression levels of miR172 caused up- or down-regulation of SsAP2-like during flower development, which affected the time of flowering. Quantitative real-time reverse transcription PCR analysis of different gloxinia tissues revealed that the accumulation of SsAP2-like was negatively correlated with the expression of miR172a, whereas the expression pattern of miR172a was negatively correlated with that of miR156a. Our results suggest that transgenic manipulation of miR172 could be used as a universal strategy for regulating time of flowering in ornamental plants.
Assuntos
Proteínas de Arabidopsis/genética , Flores/fisiologia , Proteínas de Homeodomínio/genética , Lamiales/fisiologia , MicroRNAs/genética , Proteínas Nucleares/genética , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Clonagem Molecular , DNA Complementar/metabolismo , Flores/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Lamiales/genética , MicroRNAs/metabolismo , Proteínas Nucleares/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase , TransgenesRESUMO
Audible sound, one of the environmental factors, widely exists in natural world. However, the interaction between audible sound and biological materials is usually neglected in the field of biological research. Very little efforts have been put forth in studying the relation of organisms and audible sound. Here we investigated the response of Escherichia coli cells to the stimulation by audible sound under the normal condition and environmental stresses. The results showed that the audible sound treatment significantly increases the colony forming of E. coli under the normal growth condition. However, under osmotic stress induced by the sugar, audible sound stimulation may enhance the inhibitory effect of osmotic stress on E. coli growth. More interestingly, audible sound treatment seems to alleviate the inhibitory effect of salt stress on E. coli growth when the concentration of sodium chloride was increased to 30 g/l, although the action of sound waves of audible frequency is likely to evoke an inhibition of the growth of E. coli in the medium containing 20 g/l of sodium chloride. Some potential mechanisms may be involved in the responses of bacterial cells to audible sound stimulation.