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1.
Pestic Biochem Physiol ; 170: 104700, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980067

RESUMO

Argonautes (Ago) are important core proteins in RNA interference (RNAi) pathways of eukaryotic cells. Generally, it is thought that Ago1, Ago2 and Ago3 are involved in the miRNA (microRNA), siRNA (small interfering RNA) and piRNA (Piwi-interacting RNA)-mediated RNAi pathways, respectively. As a main component of the RNA-induced silencing complex (RISC), Ago2 plays an indispensable role in using siRNA to recognize and cut target messenger RNAs resulting in suppression of transcript levels, but the contributions of Ago1 and Ago3 to the siRNA-mediated RNAi pathway remain to be explored in many insect species. In this study, we investigated the contributions of four Ago genes (named LmAgo1, LmAgo2a and LmAgo2b and LmAgo3) to RNAi efficiency in Locusta migratoria by using both in vivo and in vitro experiments. Our results showed that suppression of each of the Ago genes significantly impaired RNAi efficiency when targeting Lmß-tubulin transcripts, resulting in recovery of 48, 43.3, 61.4 or 26% of Lmß-tubulin transcripts following RNAi-mediated suppression of LmAgo1, LmAgo2a, LmAgo2b, and LmAgo3, respectively. Furthermore, overexpression of LmAgo1, LmAgo2a, LmAgo2b, or LmAgo3 in a PAc5.1-V5/HisB vector and co-transfection with psicheck2 fluorescence vector in S2 cells reduced luciferase fluorescence by 38.3, 58.9, 53.3 or 55.6%, respectively. Taken together, our results showed that LmAgo1, LmAgo2a, LmAgo2b, and LmAgo3 each make significant contributions to RNAi efficiency in L. migratoria and suggest that the involvement of all four enzymes could be one of the major factors supporting robust RNAi responses observed in this species.


Assuntos
Locusta migratoria/genética , MicroRNAs/genética , Animais , Proteínas Argonauta/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA Interferente Pequeno/genética
2.
mBio ; 11(5)2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934084

RESUMO

Bats are primary reservoirs for multiple lethal human viruses, such as Ebola, Nipah, Hendra, rabies, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome-related coronavirus (MERS-CoV), and, most recently, SARS-CoV-2. The innate immune systems of these immensely abundant, anciently diverged mammals remain insufficiently characterized. While bat genomes contain many endogenous retroviral elements indicative of past exogenous infections, little is known about restrictions to extant retroviruses. Here, we describe a major postentry restriction in cells of the yinpterochiropteran bat Pteropus alecto Primate lentiviruses (HIV-1, SIVmac) were potently blocked at early life cycle steps, with up to 1,000-fold decreases in infectivity. The block was specific, because nonprimate lentiviruses such as equine infectious anemia virus and feline immunodeficiency virus were unimpaired, as were foamy retroviruses. Interspecies heterokaryons demonstrated a dominant block consistent with restriction of incoming viruses. Several features suggested potential TRIM5 (tripartite motif 5) or myxovirus resistance protein 2 (MX2) protein restriction, including postentry action, cyclosporine sensitivity, and reversal by capsid cyclophilin A (CypA) binding loop mutations. Viral nuclear import was significantly reduced, and this deficit was substantially rescued by cyclosporine treatment. However, saturation with HIV-1 virus-like particles did not relieve the restriction at all. P. alecto TRIM5 was inactive against HIV-1 although it blocked the gammaretrovirus N-tropic murine leukemia virus. Despite major divergence in a critical N-terminal motif required for human MX2 activity, P. alecto MX2 had anti-HIV activity. However, this did not quantitatively account for the restriction and was independent of and synergistic with an additional CypA-dependent restriction. These results reveal a novel, specific restriction to primate lentiviruses in the Pteropodidae and advance understanding of bat innate immunity.IMPORTANCE The COVID-19 pandemic suggests that bat innate immune systems are insufficiently characterized relative to the medical importance of these animals. Retroviruses, e.g., HIV-1, can be severe pathogens when they cross species barriers, and bat restrictions corresponding to retroviruses are comparatively unstudied. Here, we compared the abilities of retroviruses from three genera (Lentivirus, Gammaretrovirus, and Spumavirus) to infect cells of the large fruit-eating bat P. alecto and other mammals. We identified a major, specific postentry restriction to primate lentiviruses. HIV-1 and SIVmac are potently blocked at early life cycle steps, but nonprimate lentiviruses and foamy retroviruses are entirely unrestricted. Despite acting postentry and in a CypA-dependent manner with features reminiscent of antiretroviral factors from other mammals, this restriction was not saturable with virus-like particles and was independent of P. alecto TRIM5, TRIM21, TRIM22, TRIM34, and MX2. These results identify a novel restriction and highlight cyclophilin-capsid interactions as ancient species-specific determinants of retroviral infection.


Assuntos
Quirópteros/imunologia , Gammaretrovirus/imunologia , Imunidade Inata/imunologia , Lentivirus de Primatas/imunologia , Spumavirus/imunologia , Células 3T3 , Animais , Aotidae , Gatos , Linhagem Celular , Quirópteros/virologia , Ciclofilina A/metabolismo , Furões , Gammaretrovirus/crescimento & desenvolvimento , Células HEK293 , Humanos , Lentivirus de Primatas/crescimento & desenvolvimento , Camundongos , Interferência de RNA , RNA Interferente Pequeno/genética , Spumavirus/crescimento & desenvolvimento , Proteínas com Motivo Tripartido/metabolismo
3.
Anticancer Res ; 40(9): 5035-5041, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32878791

RESUMO

BACKGROUND/AIM: Based on the cytotoxic agent (-)-zampanolide, N,N'-(arylmethylene)bisamides were designed and synthesized as candidate anti-cancer agents. Among them, N,N'-[(3,4-dimethoxyphenyl)methylene]biscinnamide (DPMBC) was identified as the most potent cytotoxic analog against cancer cells. In this study, we investigated the mechanisms underlying DPMBC-induced cell death in HL-60 human promyelocytic leukemia and PC-3 human prostate cancer cells. MATERIALS AND METHODS: Cell growth was assessed by the WST-8 assay. Induction of apoptosis was assessed by nuclear morphology, DNA ladder formation, and flow cytometry using Annexin V staining. Activation of factors in the apoptotic signaling pathway was assessed by western blot analyses. Knockdown of death receptor 5 (DR5) was performed using siRNA. RESULTS: DPMBC up-regulated expression levels of DR5 protein and induced apoptosis through the extrinsic apoptotic pathway mediated by DR5 and caspases. CONCLUSION: DPMBC is an extrinsic apoptosis inducer, which has potential as a therapeutic agent for cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Macrolídeos/farmacologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Antineoplásicos/química , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA , Relação Dose-Resposta a Droga , Humanos , Macrolídeos/química , Estrutura Molecular , RNA Interferente Pequeno/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo
4.
Anticancer Res ; 40(9): 4895-4905, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878777

RESUMO

BACKGROUND/AIM: Nicotinamide phosphoribosyl-transferase (NAMPT) is a rate-limiting enzyme in the pathway synthesizing nicotinamide adenine dinucleotide (NAD (+)) from nicotinamide (NAM). Glioma tissues exhibit up-regulated NAMPT expression associated with a poor prognosis of patients. To determine if NAMPT can be a molecular therapeutic target, we investigated the effects of short hairpin RNA (shRNA)-mediated NAMPT down-regulation. MATERIALS AND METHODS: We designed shRNA to NAMPT and transfected to T98G cells. The characteristics of these cells were analyzed. RESULTS: The NAMPT shRNA-transfected cells exhibited delayed cell growth. However, there was no difference in the increase of sensitivity to temozolomide (TMZ) or X-ray irradiation between the NAMPT and scramble shRNA-transfected cells. The expression of NAMPT in the NAMPT shRNA-transfected cells increased with cell passage. Additionally, the shRNA-mediated transfection was associated with enhanced expression of quinolinic acid phosphoribo-syltransferase (QPRT). CONCLUSION: shRNA-mediated NAMPT down-regulation may not decrease the NADt to a sufficient level to increase TMZ/radiation sensitivity.


Assuntos
Citocinas/metabolismo , Regulação para Baixo , Glioma/enzimologia , Nicotinamida Fosforribosiltransferase/metabolismo , Antineoplásicos Alquilantes/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Citocinas/genética , Glioma/metabolismo , Glioma/patologia , Humanos , NAD/metabolismo , Nicotinamida Fosforribosiltransferase/genética , Pentosiltransferases/genética , Pentosiltransferases/metabolismo , RNA Interferente Pequeno/genética , Temozolomida/farmacologia
5.
Int J Nanomedicine ; 15: 6183-6200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922001

RESUMO

Purpose: Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications. Methods: An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE12-CH-PEG-FA2/siRNA). Based on the guidelines from the International Organization for Standardization (ISO), the American Society for Testing and Materials (ASTM), and the Nanotechnology Characterization Laboratory (NCL), we evaluated the effects of the interaction between these nanoparticles and blood components. In vitro screening assays such as hemolysis, hemagglutination, complement activation, platelet aggregation, coagulation times, cytokine production, and reactive species, such as nitric oxide (NO) and reactive oxygen species (ROS), were performed on erythrocytes, plasma, platelets, peripheral blood mononuclear cells (PBMC) and Raw 264.7 macrophages. Moreover, MTS and LDH assays on Raw 264.7 macrophages, PBMC and MG-63 cells were performed. Results: Our results show that a targeted theoretical plasma concentration (TPC) of DEAE12-CH-PEG-FA2/siRNA nanoparticles falls within the guidelines' thresholds: <1% hemolysis, 2.9% platelet aggregation, no complement activation, and no effect on coagulation times. ROS and NO production levels were comparable to controls. Cytokine secretion (TNF-α, IL-6, IL-4, and IL-10) was not affected by nanoparticles except for IL-1ß and IL-8. Nanoparticles showed a slight agglutination. Cell viability was >70% for TPC in all cell types, although LDH levels were statistically significant in Raw 264.7 macrophages and PBMC after 24 and 48 h of incubation. Conclusion: These DEAE12-CH-PEG-FA2/siRNA nanoparticles fulfill the existing ISO, ASTM and NCL guidelines' threshold criteria, and their low toxicity and blood biocompatibility warrant further investigation for potential clinical applications.


Assuntos
Quitosana/química , Terapia Genética , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Ácido Fólico/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Nanopartículas/administração & dosagem , Óxido Nítrico/metabolismo , Células RAW 264.7 , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
6.
Nat Commun ; 11(1): 4709, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948765

RESUMO

Glioblastoma cancer-stem like cells (GSCs) display marked resistance to ionizing radiation (IR), a standard of care for glioblastoma patients. Mechanisms underpinning radio-resistance of GSCs remain largely unknown. Chromatin state and the accessibility of DNA lesions to DNA repair machineries are crucial for the maintenance of genomic stability. Understanding the functional impact of chromatin remodeling on DNA repair in GSCs may lay the foundation for advancing the efficacy of radio-sensitizing therapies. Here, we present the results of a high-content siRNA microscopy screen, revealing the transcriptional elongation factor SPT6 to be critical for the genomic stability and self-renewal of GSCs. Mechanistically, SPT6 transcriptionally up-regulates BRCA1 and thereby drives an error-free DNA repair in GSCs. SPT6 loss impairs the self-renewal, genomic stability and tumor initiating capacity of GSCs. Collectively, our results provide mechanistic insights into how SPT6 regulates DNA repair and identify SPT6 as a putative therapeutic target in glioblastoma.


Assuntos
Reparo do DNA , Instabilidade Genômica , Glioblastoma/genética , Células-Tronco Neoplásicas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Animais , Apoptose , Proteína BRCA1 , Neoplasias Encefálicas/genética , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Inativação Gênica , Glioblastoma/patologia , Células HEK293 , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Células-Tronco Neoplásicas/patologia , RNA Interferente Pequeno/genética , Tolerância a Radiação , Radiação Ionizante , Transcriptoma
7.
Anticancer Res ; 40(10): 5545-5556, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988878

RESUMO

BACKGROUND/AIM: The p38 family of mitogen-activated protein kinases (MAPK) includes four isoforms: p38α, -ß, -γ and -δ. The aim of this study was to elucidate possible functions of p38α and p38ß in human pancreatic cancer. MATERIALS AND METHODS: Isoform expression was determined in seven human pancreatic cancer cell lines. After shRNA based selective knockdown of p38α and p38ß, in vitro growth and migration as well as in vivo tumorigenicity were assessed. RESULTS: All pancreatic cancer cells expressed p38 isoforms. Knockdown of p38α and p38ß inhibited in vitro growth. Migration was markedly reduced in p38α shRNA expressing clones, but not altered by p38ß knockdown. While in vivo inhibition of p38ß decreased tumor formation and growth, the knockdown of p38α significantly enhanced tumorigenicity. CONCLUSION: p38 MAPKs may exert isoform specific functions in pancreatic cancer. Selective targeting may contribute to individualized treatment of pancreatic cancer in the future.


Assuntos
Proteína Quinase 11 Ativada por Mitógeno/genética , Proteína Quinase 14 Ativada por Mitógeno/genética , Neoplasias Pancreáticas/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pancreáticas/patologia , Fosforilação , Isoformas de Proteínas/genética , RNA Interferente Pequeno/genética
8.
Pharm Res ; 37(10): 196, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32944844

RESUMO

PURPOSE: Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules. METHODS: In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth. RESULTS: The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells. CONCLUSIONS: These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFß, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Experimentais/terapia , Compostos de Piridínio/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Quitosana/química , Grafite/química , Ácido Hialurônico/química , Camundongos , Nanopartículas/química , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Compostos de Piridínio/química , Compostos de Piridínio/farmacocinética , RNA Interferente Pequeno/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacocinética
9.
PLoS One ; 15(8): e0237577, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790741

RESUMO

Abnormal skin melanin homeostasis results in refractory pigmentary diseases. Melanogenesis is influenced by gene regulation, ultraviolet radiation, and host epigenetic responses. Steroid receptor RNA activator (SRA), a long noncoding RNA, is known to regulate steroidogenesis and tumorigenesis. However, how SRA contributes to melanogenesis remains unknown. Using RNA interference against SRA in B16 and A375 melanoma cells, we observed increased pigmentation and increased expression of TRP1 and TRP2 at transcriptional and translational levels only in B16 cells. The constitutive phosphorylation of p38 in B16-shCtrl cells was inhibited in cells with knocked down SRAi. Moreover, the melanin content of control B16 cells was increased by SB202190, a p38 inhibitor. Furthermore, reduced p38 phosphorylation, enhanced TRP1 expression, and hypermelanosis were observed in A375 cells with RNA interference. These results indicate that SRA-p38-TRP1 axis has a regulatory role in melanin homeostasis and that SRA might be a potential therapeutic target for treating pigmentary diseases.


Assuntos
Oxirredutases Intramoleculares/metabolismo , Melaninas/metabolismo , Melanoma Experimental/patologia , Glicoproteínas de Membrana/metabolismo , Oxirredutases/metabolismo , RNA Longo não Codificante/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Regulação Neoplásica da Expressão Gênica , Oxirredutases Intramoleculares/genética , Melanoma Experimental/genética , Melanoma Experimental/metabolismo , Glicoproteínas de Membrana/genética , Camundongos , Oxirredutases/genética , Fosforilação , RNA Longo não Codificante/genética , RNA Interferente Pequeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genética
10.
Nat Commun ; 11(1): 3806, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732922

RESUMO

Most triple-negative breast cancer (TNBC) patients fail to respond to T cell-mediated immunotherapies. Unfortunately, the molecular determinants are still poorly understood. Breast cancer is the disease genetically linked to a deficiency in autophagy. Here, we show that autophagy defects in TNBC cells inhibit T cell-mediated tumour killing in vitro and in vivo. Mechanistically, we identify Tenascin-C as a candidate for autophagy deficiency-mediated immunosuppression, in which Tenascin-C is Lys63-ubiquitinated by Skp2, particularly at Lys942 and Lys1882, thus promoting its recognition by p62 and leading to its selective autophagic degradation. High Tenascin-C expression is associated with poor prognosis and inversely correlated with LC3B expression and CD8+ T cells in TNBC patients. More importantly, inhibition of Tenascin-C in autophagy-impaired TNBC cells sensitizes T cell-mediated tumour killing and improves antitumour effects of single anti-PD1/PDL1 therapy. Our results provide a potential strategy for targeting TNBC with the combination of Tenascin-C blockade and immune checkpoint inhibitors.


Assuntos
Autofagia/imunologia , Linfócitos T CD8-Positivos/imunologia , Tenascina/metabolismo , Neoplasias de Mama Triplo Negativas/imunologia , Evasão Tumoral/imunologia , Animais , Antineoplásicos Imunológicos/farmacologia , Autofagia/genética , Antígeno B7-H1/antagonistas & inibidores , Linfócitos T CD8-Positivos/transplante , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Imunoterapia Adotiva , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Prognóstico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/terapia , Evasão Tumoral/genética
11.
Nat Commun ; 11(1): 4124, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807787

RESUMO

In response to DNA damage, a synthetic lethal relationship exists between the cell cycle checkpoint kinase MK2 and the tumor suppressor p53. Here, we describe the concept of augmented synthetic lethality (ASL): depletion of a third gene product enhances a pre-existing synthetic lethal combination. We show that loss of the DNA repair protein XPA markedly augments the synthetic lethality between MK2 and p53, enhancing anti-tumor responses alone and in combination with cisplatin chemotherapy. Delivery of siRNA-peptide nanoplexes co-targeting MK2 and XPA to pre-existing p53-deficient tumors in a highly aggressive, immunocompetent mouse model of lung adenocarcinoma improves long-term survival and cisplatin response beyond those of the synthetic lethal p53 mutant/MK2 combination alone. These findings establish a mechanism for co-targeting DNA damage-induced cell cycle checkpoints in combination with repair of cisplatin-DNA lesions in vivo using RNAi nanocarriers, and motivate further exploration of ASL as a generalized strategy to improve cancer treatment.


Assuntos
Pontos de Checagem do Ciclo Celular/fisiologia , Reparo do DNA/fisiologia , Animais , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Dano ao DNA/genética , Dano ao DNA/fisiologia , Reparo do DNA/genética , Células HCT116 , Humanos , Immunoblotting , Camundongos , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Nanomedicina/métodos , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
12.
Nat Commun ; 11(1): 3812, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732889

RESUMO

Vascular endothelial cell (EC) dysfunction plays a key role in diabetic complications. This study discovers significant upregulation of Quaking-7 (QKI-7) in iPS cell-derived ECs when exposed to hyperglycemia, and in human iPS-ECs from diabetic patients. QKI-7 is also highly expressed in human coronary arterial ECs from diabetic donors, and on blood vessels from diabetic critical limb ischemia patients undergoing a lower-limb amputation. QKI-7 expression is tightly controlled by RNA splicing factors CUG-BP and hnRNPM through direct binding. QKI-7 upregulation is correlated with disrupted cell barrier, compromised angiogenesis and enhanced monocyte adhesion. RNA immunoprecipitation (RIP) and mRNA-decay assays reveal that QKI-7 binds and promotes mRNA degradation of downstream targets CD144, Neuroligin 1 (NLGN1), and TNF-α-stimulated gene/protein 6 (TSG-6). When hindlimb ischemia is induced in diabetic mice and QKI-7 is knocked-down in vivo in ECs, reperfusion and blood flow recovery are markedly promoted. Manipulation of QKI-7 represents a promising strategy for the treatment of diabetic vascular complications.


Assuntos
Diabetes Mellitus Experimental/patologia , Células Endoteliais/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/metabolismo , Doenças Vasculares/patologia , Animais , Antígenos CD/genética , Aterosclerose/patologia , Caderinas/genética , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular Neuronais/genética , Células Cultivadas , Regulação da Expressão Gênica/genética , Humanos , Hiperglicemia/patologia , Isquemia/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/genética
13.
PLoS One ; 15(8): e0237015, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760098

RESUMO

Graves' orbitopathy (GO) is characterised in early stages by orbital fibroblast inflammation, which can be aggravated by oxidative stress and often leads to fibrosis. Protein tyrosine protein 1B (PTP1B) is a regulator of inflammation and a therapeutic target in diabetes. We investigated the role of PTP1B in the GO mechanism using orbital fibroblasts from GO and healthy non-GO subjects. After 24 hours of transfection with PTPN1 siRNA, the fibroblasts were exposed to interleukin (IL)-1ß, cigarette smoke extract (CSE), H2O2, and transforming growth factor (TGF)-ß stimulations. Inflammatory cytokines and fibrosis-related proteins were analysed using western blotting and/or enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) release was detected using an oxidant-sensitive fluorescent probe. IL-1ß, tumor necrosis factor (TNF)-α, bovine thyroid stimulating hormone (bTSH), high-affinity human stimulatory monoclonal antibody of TSH receptor (M22), and insulin-like growth factor-1 (IGF-1) significantly increased PTP1B protein production in GO and non-GO fibroblasts. PTPN1 silencing significantly blocked IL-1ß-induced inflammatory cytokine production, CSE- and H2O2-induced ROS synthesis, and TGF-ß-induced expression of collagen Iα, α-smooth muscle actin (SMA), and fibronectin in GO fibroblasts. Silencing PTPN1 also decreased phosphorylation levels of Akt, p38, and c-Jun N-terminal kinase (JNK) and endoplasmic reticulum (ER)-stress response proteins in GO cells. PTP1B may be a potential therapeutic target of anti-inflammatory, anti-oxidant and anti-fibrotic treatment of GO.


Assuntos
Oftalmopatia de Graves/enzimologia , Oftalmopatia de Graves/terapia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Adulto , Animais , Apoptose , Bovinos , Sobrevivência Celular , Citocinas/biossíntese , Estresse do Retículo Endoplasmático , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Inativação Gênica , Oftalmopatia de Graves/patologia , Humanos , Técnicas In Vitro , Mediadores da Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
14.
PLoS One ; 15(8): e0236968, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745140

RESUMO

Many circumstantial evidences from human and animal studies suggest that complement cascade dysregulation may play an important role in pregnancy associated complications including preeclampsia. Deletion of rodent specific complement inhibitor gene, Complement Receptor 1-related Gene/Protein y (Crry) produces embryonic lethal phenotype due to complement activation. It is not clear if decreased expression of Crry during pregnancy produces hypertensive phenotype. We downregulated Crry in placenta by injecting inducible lentivialshRNA vectors into uterine horn of pregnant C57BL/6 mice at the time of blastocyst hatching. Placenta specific downregulation of Crry without significant loss of embryos was achieved upon induction of shRNA using an optimal doxycycline dose at mid gestation. Crry downregulation resulted in placental complement deposition. Late-gestation measurements showed that fetal weights were reduced and blood pressure increased in pregnant mice upon downregulation of Crry suggesting a critical role for Crry in fetal growth and blood pressure regulation.


Assuntos
Desenvolvimento Fetal/fisiologia , Placenta/metabolismo , Receptores de Complemento 3b/genética , Animais , Pressão Sanguínea/genética , Ativação do Complemento/genética , Complemento C3/metabolismo , Inativadores do Complemento/farmacologia , Feminino , Desenvolvimento Fetal/genética , Regulação da Expressão Gênica/genética , Camundongos , Camundongos Endogâmicos C57BL , Placenta/fisiologia , Pré-Eclâmpsia/genética , Gravidez , RNA Interferente Pequeno/genética , Receptores de Complemento/genética , Receptores de Complemento 3b/metabolismo
15.
PLoS One ; 15(8): e0237675, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797066

RESUMO

RNA interference (RNAi), a technique used to investigate gene function in insects and other organisms, is attracting attention as a potential new technology for mosquito control. Saccharomyces cerevisiae (baker's yeast) was recently engineered to produce interfering RNA molecules that silence genes required for mosquito survival, but which do not correspond to genes in humans or other non-target organisms. The resulting yeast pesticides, which facilitate cost-effective production and delivery of interfering RNA to mosquito larvae that eat the yeast, effectively kill mosquitoes in laboratory and semi-field trials. In preparation for field evaluation of larvicides in Trinidad, a Caribbean island with endemic diseases resulting from pathogens transmitted by Aedes mosquitoes, adult residents living in the prospective trial site communities of Curepe, St. Augustine, and Tamana were engaged. Open community forums and paper surveys were used to assess the potential acceptability, societal desirability, and sustainability of yeast interfering RNA larvicides. These assessments revealed that Trinidadians have good working knowledge of mosquitoes and mosquito-borne illnesses. A majority of the respondents practiced some method of larval mosquito control and agreed that they would use a new larvicide if it were proven to be safe and effective. During the community engagement forums, participants were educated about mosquito biology, mosquito-borne diseases, and the new yeast larvicides. When invited to provide feedback, engagement forum attendees were strongly supportive of the new technology, raised few concerns, and provided helpful advice regarding optimal larvicide formulations, insecticide application, operational approaches for using the larvicides, and pricing. The results of these studies suggest that the participants are supportive of the potential use of yeast interfering RNA larvicides in Trinidad and that the communities assessed in this investigation represent viable field sites.


Assuntos
Aedes/genética , Engenharia Genética/métodos , Controle de Mosquitos/métodos , Interferência de RNA , Saccharomyces cerevisiae/genética , Adulto , Animais , Feminino , Humanos , Larva/genética , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/genética , Controle Biológico de Vetores/métodos , RNA Interferente Pequeno/genética , Características de Residência , Inquéritos e Questionários , Trinidad e Tobago
16.
Nat Protoc ; 15(9): 3064-3087, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32807907

RESUMO

Targeted downregulation of select endogenous plant genes is known to confer disease or pest resistance in crops and is routinely accomplished via transgenic modification of plants for constitutive gene silencing. An attractive alternative to the use of transgenics or pesticides in agriculture is the use of a 'green' alternative known as RNAi, which involves the delivery of siRNAs that downregulate endogenous genes to confer resistance. However, siRNA is a molecule that is highly susceptible to enzymatic degradation and is difficult to deliver across the lignin-rich and multi-layered plant cell wall that poses the dominant physical barrier to biomolecule delivery in plants. We have demonstrated that DNA nanostructures can be utilized as a cargo carrier for direct siRNA delivery and gene silencing in mature plants. The size, shape, compactness and stiffness of the DNA nanostructure affect both internalization into plant cells and subsequent gene silencing efficiency. Herein, we provide a detailed protocol that can be readily adopted with standard biology benchtop equipment to generate geometrically optimized DNA nanostructures for transgene-free and force-independent siRNA delivery and gene silencing in mature plants. We further discuss how such DNA nanostructures can be rationally designed to efficiently enter plant cells and deliver cargoes to mature plants, and provide guidance for DNA nanostructure characterization, storage and use. The protocol described herein can be completed in 4 d.


Assuntos
DNA/química , Portadores de Fármacos/química , Engenharia , Nanoestruturas/química , RNA Interferente Pequeno/metabolismo , Tabaco/metabolismo , DNA/metabolismo , Portadores de Fármacos/metabolismo , RNA Interferente Pequeno/genética , Tabaco/genética
17.
PLoS Genet ; 16(8): e1008915, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776928

RESUMO

Sequences homologous to human herpesvirus 6 (HHV-6) are integrated within the nuclear genome of about 1% of humans, but it is not clear how this came about. It is also uncertain whether integrated HHV-6 can reactivate into an infectious virus. HHV-6 integrates into telomeres, and this has recently been associated with polymorphisms affecting MOV10L1. MOV10L1 is located on the subtelomere of chromosome 22q (chr22q) and is required to make PIWI-interacting RNAs (piRNAs). As piRNAs block germline integration of transposons, piRNA-mediated repression of HHV-6 integration has been proposed to explain this association. In vitro, recombination of the HHV-6 genome along its terminal direct repeats (DRs) leads to excision from the telomere and viral reactivation, but the expected "solo-DR scar" has not been described in vivo. Here we screened for integrated HHV-6 in 7,485 Japanese subjects using whole-genome sequencing (WGS). Integrated HHV-6 was associated with polymorphisms on chr22q. However, in contrast to prior work, we find that the reported MOV10L1 polymorphism is physically linked to an ancient endogenous HHV-6A variant integrated into the telomere of chr22q in East Asians. Unexpectedly, an HHV-6B variant has also endogenized in chr22q; two endogenous HHV-6 variants at this locus thus account for 72% of all integrated HHV-6 in Japan. We also report human genomes carrying only one portion of the HHV-6B genome, a solo-DR, supporting in vivo excision and possible viral reactivation. Together these results explain the recently-reported association between integrated HHV-6 and MOV10L1/piRNAs, suggest potential exaptation of HHV-6 in its coevolution with human chr22q, and clarify the evolution and risk of reactivation of the only intact (non-retro)viral genome known to be present in human germlines.


Assuntos
Genoma Humano , Herpesvirus Humano 6/genética , Integração Viral , Grupo com Ancestrais do Continente Asiático/genética , Cromossomos Humanos Par 22/genética , Evolução Molecular , Mutação em Linhagem Germinativa , Humanos , Polimorfismo de Nucleotídeo Único , RNA Interferente Pequeno/genética
18.
Mol Cell Biol ; 40(20)2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32778571

RESUMO

Many proteins, including DICER1 and hAgo2, are involved in the biogenesis of microRNAs (miRNAs). Whether hAgo2 regulates DICER1 expression is unknown. Exogenously overexpressed hAgo2 suppressed DICER1 expression at the levels of both protein and mRNA, and the reduction in hAgo2 expression enhanced DICER1 expression. Precursor miRNA processing mediated by DICER1 was also modulated by hAgo2. However, hAgo2 protein did not suppress DICER1 promoter activity. Therefore, hAgo2 protein probably regulates DICER1 expression at the posttranscriptional level. Indeed, hAgo2 protein inhibited the reporter assay of the DICER1 mRNA 3' untranslated region (3'-UTR). Previous reports have demonstrated that miRNAs (e.g., let-7 and miR-103/107) inhibited DICER1 expression posttranscriptionally. However, hAgo2 still suppressed DICER1 expression in the cells depleted of these miRNAs. Moreover, the reporter activities of the DICER1 mRNA 3'-UTR without these miRNA binding sites were still suppressed by hAgo2. Therefore, in addition to an miRNA-dependent pathway, hAgo2 can also modulate DICER1 expression through an miRNA-independent mechanism. Downregulation of DICER1 expression was further proven to be dependent on both hAgo2 and AUF1 proteins. Interactions of hAgo2 and AUF1 proteins were demonstrated by the coimmunoprecipitation assay. As expected, hAgo2 could not suppress the DICER1 mRNA 3'-UTR reporter with a mutation in the potential AUF1-binding site. Thus, downregulation of DICER1 expression through the 3'-UTR requires both hAgo2 and AUF1.


Assuntos
Proteínas Argonauta/genética , RNA Helicases DEAD-box/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Neoplasias/genética , Ribonuclease III/genética , Regiões 3' não Traduzidas/genética , Células A549 , Proteínas Argonauta/metabolismo , Sítios de Ligação/genética , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , RNA Helicases DEAD-box/metabolismo , Células HEK293 , Células HeLa , Ribonucleoproteína Nuclear Heterogênea D0/genética , Ribonucleoproteína Nuclear Heterogênea D0/metabolismo , Humanos , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Ribonuclease III/metabolismo
19.
Int J Nanomedicine ; 15: 5575-5589, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801705

RESUMO

Purpose: The overexpression of Her-2 in 25-30% breast cancer cases and the crosstalk between Her-2 and fatty acid synthase (FASN) establishes Her-2 as a promising target for site-directed delivery. The present study aimed to develop the novel lipid base formulations to target and inhibit the cellular proliferation of Her-2-expressing breast cancer cells through the silencing of FASN. In order to achieve this goal, we prepared DSPC/Chol and DOPE/CHEMS immunoliposomes, conjugated with the anti-Her-2 fab' and encapsulated FASN siRNA against breast cancer cells. Methods: We evaluated the size, stability, cellular uptake and internalization of various formulations of liposomes. The antiproliferative gene silencing potential was investigated by the cell cytotoxicity, crystal violet, wound healing and Western blot analyses in Her-2+ and Her-2¯ breast cancer cells. Results: The data revealed that both nanosized FASN-siRNA-encapsulated liposomes showed significantly higher cellular uptake and internalization with enhanced stability. The cell viability of Her-2+ SK-BR3 cells treated with the targeted formulation of DSPC/Chol- and DOPE/CHEMS-encapsulating FASN-siRNA reduced to 30% and 20%, respectively, whereas it was found to be 45% and 36% in MCF-7 cells. The wounds were not only failed to close but they became broader in Her-2+ cells treated with targeted liposomes of siRNA. Consequently, the amount of FASN decreased by 80% in SK-BR3 cells treated with non-targeted liposomes and it was 30% and 60% in the MCF-7 cells treated with DSPC/Chol and DOPE/CHEMS liposomes, respectively. Conclusion: In this study, we developed the formulation that targeted Her-2 for the suppression of FASN and, therefore, inhibited the proliferation of breast cancer cells.


Assuntos
Neoplasias da Mama/genética , Ácido Graxo Sintase Tipo I/genética , Terapia de Alvo Molecular/métodos , Receptor ErbB-2/metabolismo , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Feminino , Inativação Gênica , Humanos , Concentração de Íons de Hidrogênio , Fragmentos Fab das Imunoglobulinas/química , Lipídeos/química , Lipossomos/administração & dosagem , Lipossomos/química , Lipossomos/imunologia , Células MCF-7 , RNA Interferente Pequeno/genética , Receptor ErbB-2/imunologia
20.
Nat Commun ; 11(1): 4242, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843637

RESUMO

Membraneless organelles are sites for RNA biology including small non-coding RNA (ncRNA) mediated gene silencing. How small ncRNAs utilise phase separated environments for their function is unclear. We investigated how the PIWI-interacting RNA (piRNA) pathway engages with the membraneless organelle P granule in Caenorhabditis elegans. Proteomic analysis of the PIWI protein PRG-1 reveals an interaction with the constitutive P granule protein DEPS-1. DEPS-1 is not required for piRNA biogenesis but piRNA-dependent silencing: deps-1 mutants fail to produce the secondary endo-siRNAs required for the silencing of piRNA targets. We identify a motif on DEPS-1 which mediates a direct interaction with PRG-1. DEPS-1 and PRG-1 form intertwining clusters to build elongated condensates in vivo which are dependent on the Piwi-interacting motif of DEPS-1. Additionally, we identify EDG-1 as an interactor of DEPS-1 and PRG-1. Our study reveals how specific protein-protein interactions drive the spatial organisation and piRNA-dependent silencing within membraneless organelles.


Assuntos
Proteínas Argonauta/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Inativação Gênica , RNA Interferente Pequeno/metabolismo , Animais , Proteínas Argonauta/genética , Sítios de Ligação , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Grânulos Citoplasmáticos/metabolismo , Células Germinativas/metabolismo , Mutação , Ligação Proteica , Proteômica , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/genética
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