RESUMEN
Maternal diabetes has been associated with a greater risk of neurodevelopmental disorders in offspring. It has been established that hyperglycemia alters the expression of genes and microRNAs (miRNAs) regulating the fate of neural stem cells (NSCs) during brain development. In this study, the expression of methyl-CpG-binding protein-2 (Mecp2), a global chromatin organizer and a crucial regulator of synaptic proteins, was analyzed in NSCs obtained from the forebrain of embryos of diabetic mice. Mecp2 was significantly downregulated in NSCs derived from embryos of diabetic mice when compared to controls. miRNA target prediction revealed that the miR-26 family could regulate the expression of Mecp2, and further validation confirmed that Mecp2 is a target of miR-26b-5p. Knockdown of Mecp2 or overexpression of miR-26b-5p altered the expression of tau protein and other synaptic proteins, suggesting that miR-26b-5p alters neurite outgrowth and synaptogenesis via Mecp2. This study revealed that maternal diabetes upregulates the expression of miR-26b-5p in NSCs, resulting in downregulation of its target, Mecp2, which in turn perturbs neurite outgrowth and expression of synaptic proteins. Overall, hyperglycemia dysregulates synaptogenesis that may manifest as neurodevelopmental disorders in offspring from diabetic pregnancy.
Asunto(s)
Diabetes Mellitus Experimental , Hiperglucemia , MicroARNs , Células-Madre Neurales , Embarazo , Femenino , Animales , Ratones , Diabetes Mellitus Experimental/genética , MicroARNs/genética , MicroARNs/metabolismo , Células-Madre Neurales/metabolismo , Neurogénesis/genética , Hiperglucemia/genética , Proteína 2 de Unión a Metil-CpG/genéticaRESUMEN
Breast carcinoma is the most prevalent cancer in women globally, with complex genetic and molecular mechanisms that underlie its development and progression. Several challenges such as metastasis and drug resistance limit the prognosis of breast cancer, and hence a constant search for better treatment regimes, including novel molecular therapeutic targets is necessary. Complement component 1, q subcomponent binding protein (C1QBP), a promising molecular target, has been implicated in breast carcinogenesis. In this study, the role of C1QBP in breast cancer progression, in particular cancer cell growth, was determined in triple negative MDA-MB-231 breast cancer cells. Depletion of C1QBP decreased cell proliferation, whereas the opposite effect was observed when C1QBP was overexpressed in MDA-MB-231 cells. Furthermore, gene expression profiling and pathway analysis in C1QBP depleted cells revealed that C1QBP regulates several signaling pathways crucial for cell growth and survival. Taken together, these findings provide a deeper comprehension of the role of C1QBP in triple negative breast cancer, and could possibly pave the way for future advancement of C1QBP-targeted breast cancer therapy.
Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Femenino , Humanos , Neoplasias de la Mama/metabolismo , Proteínas Mitocondriales/metabolismo , Transducción de Señal , Proteínas Portadoras/metabolismo , Proliferación Celular , Línea Celular Tumoral , Neoplasias de la Mama Triple Negativas/genéticaRESUMEN
Maternal diabetes alters the global epigenetic mechanisms and expression of genes involved in neural tube development in mouse embryos. Since DNA methylation is a critical epigenetic mechanism that regulates gene functions, gene-specific DNA methylation alterations were estimated in human neural progenitor cells (hNPCs) exposed to high glucose (HG) in the present study. The DNA methylation pattern of genes involved in several signalling pathways including axon guidance (SLIT1-ROBO2 pathway), and Hippo pathway (YAP and TAZ) was altered in hNPCs exposed to HG. The expression levels of SLIT1-ROBO2 pathways genes (including its effectors, SRGAP1 and CDC42) which mediates diverse cellular processes such as proliferation, neurogenesis and axon guidance, and Hippo pathway genes (YAP and TAZ) which regulates proliferation, stemness, differentiation and organ size were downregulated in hNPCs exposed to HG. A recent report suggests a possible cross-talk between SLIT1-ROBO2 and TAZ via CDC42, a mediator of actin dynamics. Consistent with this, SLIT1 knockdown downregulated the expression of its effectors and TAZ in hNPCs, suggesting that HG perturbs the cross-talk between SLIT1-ROBO2 and TAZ in hNPCs. Overall, this study demonstrates that HG epigenetically alters the SLIT1-ROBO2 and Hippo signalling pathways in hNPCs, forming the basis for neurodevelopmental disorders in offspring of diabetic pregnancy.
Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Metilación de ADN/efectos de los fármacos , Glucosa/farmacología , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Encéfalo/citología , Relación Dosis-Respuesta a Droga , Epigénesis Genética/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Genómica , Vía de Señalización Hippo , Humanos , Proteínas del Tejido Nervioso/metabolismo , Células-Madre Neurales/citología , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Aim: This study was aimed to understand if Zika virus (ZIKV) alters the DNA methylome of human neural progenitor cells (hNPCs). Materials & methods: Whole genome DNA methylation profiling was performed using human methylationEPIC array in control and ZIKV infected hNPCs. Results & conclusion: ZIKV infection altered the DNA methylation of several genes such as WWTR1 (TAZ) and RASSF1 of Hippo signaling pathway which regulates organ size during brain development, and decreased the expression of several centrosomal-related microcephaly genes, and genes involved in stemness and differentiation in human neural progenitor cells. Overall, ZIKV downregulated the Hippo signaling pathway genes which perturb the stemness and differentiation process in hNPCs, which could form the basis for ZIKV-induced microcephaly.
Asunto(s)
Biomarcadores/análisis , Diferenciación Celular , Metilación de ADN , Regulación de la Expresión Génica , Células-Madre Neurales/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Infección por el Virus Zika/virología , Células Cultivadas , Vía de Señalización Hippo , Humanos , Células-Madre Neurales/citología , Células-Madre Neurales/virología , Transducción de Señal , Transactivadores/antagonistas & inhibidores , Transactivadores/genética , Transactivadores/metabolismo , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Proteínas Supresoras de Tumor/antagonistas & inhibidores , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Virus Zika/fisiología , Infección por el Virus Zika/genética , Infección por el Virus Zika/metabolismoRESUMEN
Y-box binding protein-1 (YB-1), an important transcription and translation regulator protein, is known to increase cancer cell invasiveness and spreading. Here, we report its role in breast cancer, particularly in mediating cell invasion in triple-negative breast cancer (TNBC). YB-1 stable knockdown (shYB-1) significantly reduced the invasive potential of MDA-MB-231 TNBC cells in 2D and 3D (spheroid) cultures. Whole proteome mass spectrometry analysis showed an enrichment of cell adhesion and cell to matrix interaction proteins, notably, matrix metalloproteinase-1 (MMP1) and beta-catenin (CTNNB1), which are known to play critical roles in cancer metastasis. shYB-1â¯cells exhibited substantial downregulation of MMP1 and CTNNB1 mRNA and protein expression, with reduced MMP1 enzyme activity. YB-1 was also observed to bind to the promoter of MMP1 and overexpression of MMP1 plasmid in shYB-1â¯cells increased cell invasion. Finally, analysis of tumour samples from the Gene Expression-Based Outcome for Breast Cancer Online (GOBO) database revealed that high gene expressions of YBX1, MMP1 and CTNNB1 predict for a significantly lower 10-year distant metastasis free survival. Altogether, this study shows that YB-1 mediates breast cancer invasion and metastasis via regulation of MMP1 and beta-catenin.
Asunto(s)
Metaloproteinasa 1 de la Matriz/biosíntesis , Neoplasias de la Mama Triple Negativas/patología , Proteína 1 de Unión a la Caja Y/genética , beta Catenina/biosíntesis , Movimiento Celular/genética , Proliferación Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Metaloproteinasa 1 de la Matriz/genética , Invasividad Neoplásica/genética , Regiones Promotoras Genéticas/genética , Interferencia de ARN , ARN Mensajero/biosíntesis , ARN Interferente Pequeño/genética , Esferoides Celulares , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/mortalidad , Células Tumorales Cultivadas , beta Catenina/genéticaRESUMEN
INTRODUCTION: Chronic activation of microglia is the hallmark of numerous neuropathologies such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. The activated microglia perpetuate inflammation by releasing an array of pro-inflammatory and neurotoxic factors, which eventually exacerbate neurotoxicity and neurodegeneration upon chronic activation of these cells. However, under acute conditions, activated microglia elicit pro-inflammatory as well as anti-inflammatory responses that are associated with neuroprotection. Given the role of microglia in neuroinflammation, recent studies have attempted to unravel the mechanisms that aid to establish microglial cell-based therapy. Areas covered: While total suppression of microglial activation may compromise its beneficial role in tissue repair in the aftermath of an insult, the benefits of modulating microglial activation and promoting microglia polarization to a neuroprotective phenotype have been highlighted recently. Expert opinion: So far, the therapeutic strategy focussed on neutralizing microglia-mediated neuroinflammation using drugs that block the release of pro-inflammatory mediators has limitations, such as unwarranted side effects. Recent advances reveal several alternative molecular targets and potential epi-drugs that are capable of modulating microglial function and promoting neuroprotection. This review discusses the recent progress made in understanding the mechanisms of microglia-mediated neuroinflammation in various neuropathologies, and the emerging anti-inflammatory therapeutic strategies in this field.
Asunto(s)
Antiinflamatorios/farmacología , Enfermedades Neurodegenerativas/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Animales , Antiinflamatorios/efectos adversos , Diseño de Fármacos , Humanos , Inflamación/tratamiento farmacológico , Inflamación/fisiopatología , Mediadores de Inflamación/metabolismo , Microglía/metabolismo , Terapia Molecular Dirigida , Enfermedades Neurodegenerativas/fisiopatología , Fármacos Neuroprotectores/efectos adversosRESUMEN
microRNAs (miRNAs) regulate diverse cellular functions and signaling pathways via inhibiting the expression of their target genes. Given that miR-128 mediates mitogen-activated protein kinase signaling and production of reactive oxygen species and pro-inflammatory chemokines in various types of cells and tissues, and that miR-128 is differentially expressed in aged and diseased kidneys, we hypothesized that miR-128 may play key roles in kidney inflammation. Hence, in this study, we evaluated the biological effects of miR-128 in normal rat kidney (NRK) cells in vitro. Our results revealed that overexpression of miR-128 enhanced expression of genes associated with inflammation, pro-inflammatory cytokines and fibrosis in NRK cells. The recent reports showing that expression of miR-128 is increased in liver and lung fibrosis, together with the findings in this study, suggest that miR-128 may be a pro-fibrotic miRNA that regulates fibrosis in various tissues. Anat Rec, 301:913-921, 2018. © 2017 Wiley Periodicals, Inc.
Asunto(s)
Fibrosis/genética , Regulación de la Expresión Génica , Inflamación/genética , Riñón/metabolismo , Riñón/patología , MicroARNs/genética , Animales , Línea Celular , Fibrosis/metabolismo , Fibrosis/patología , Inflamación/metabolismo , Inflamación/patología , Ratones , MicroARNs/metabolismo , Ratas , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Maternal diabetes is known to cause neural tube defects (NTDs) in embryos and neuropsychological deficits in infants. Several metabolic pathways and a plethora of genes have been identified to be deregulated in developing brain of embryos by maternal diabetes, although the exact mechanism remains unknown. Recently, miRNAs have been shown to regulate genes involved in brain development and maturation. Therefore, we hypothesized that maternal diabetes alters the expression of miRNAs that regulate genes involved in biological pathways critical for neural tube development and closure during embryogenesis. To address this, high throughput miRNA expression profiling in neural stem cells (NSCs) isolated from the forebrain of embryos from normal or streptozotocin-induced diabetic pregnancy was carried out. It is known that maternal diabetes results in fetal hypoglycemia/hyperglycemia or hypoxia. Hence, NSCs from embryos of control pregnant mice were exposed to low or high glucose or hypoxia in vitro. miRNA pathway analysis revealed distinct deregulation of several biological pathways, including axon guidance pathway, which are critical for brain development in NSCs exposed to different treatments. Among the differentially expressed miRNAs, the miRNA-30 family members which are predicted to target genes involved in brain development was upregulated in NSCs from embryos of diabetic pregnancy when compared to control. miRNA-30b was found to be upregulated while its target gene Sirtuin 1 (Sirt1), as revealed by luciferase assay, was down regulated in NSCs from embryos of diabetic pregnancy. Further, overexpression of miRNA-30b in NSCs, resulted in decreased expression of Sirt1 protein, and altered the neuron/glia ratio. On the other hand, siRNA mediated knockdown of Sirt1 in NSCs promoted astrogenesis, indicating that miRNA-30b alters lineage specification via Sirt1. Overall, these results suggest that maternal diabetes alters the genes involved in neural tube formation via regulating miRNAs.
RESUMEN
BACKGROUND: Y-box binding protein-1 is an evolutionary conserved transcription and translation regulating protein that is overexpressed in various human malignancies, including breast cancer. Despite reports of YB-1 and its association with distant spread of breast cancer, the intrinsic mechanism underlying this observation remains elusive. This study investigates the role of YB-1 in mediating metastasis in highly invasive breast cancer cell lines. METHODS: Silencing the YBX1 gene (which encodes the YB-1 protein) by small interfering RNA (siRNA) was performed in MDA-MB-231 and Hs578T breast cancer cell lines, followed by phenotypic assays including cell migration and invasion assays. Gene expression profiling using Affymetrix GeneChip® Human Transcriptome 2.0 array was subsequently carried out in YB-1 silenced MDA-MB-231 cells. Overexpression and silencing of YBX1 were performed to assess the expression of CORO1C, one of the differentially regulated genes from the transcriptomic analysis. A Gaussia luciferase reporter assay was used to determine if CORO1C is a putative YB-1 downstream target. siRNA-mediated silencing of CORO1C and down-regulation of YBX1 in CORO1C overexpressing MDA-MB-231 cells were performed to evaluate cell migration and invasion. RESULTS: Downregulation of the YB-1 protein inhibited cell migration and invasion in MDA-MB-231 breast cancer cells. Global gene expression profiling in the YBX1 silenced MDA-MB-231 cells identified differential expression of several genes, including CORO1C (which encodes for an actin binding protein, coronin-1C) as a potential downstream target of YB-1. While knockdown of YBX1 gene decreased CORO1C gene expression, the opposite effects were seen in YB-1 overexpressing cells. Subsequent verification using the reporter assay revealed that CORO1C is an indirect downstream target of YB-1. Silencing of CORO1C by siRNA in MDA-MB-231 cells was also observed to reduce cell migration and invasion. Silencing of YBX1 caused a similar reduction in CORO1C expression, concomitant with a significant decrease in migration in Hs578T cells. In coronin-1C overexpressing MDA-MB-231 cells, increased migration and invasion were abrogated by YB-1 knockdown. CONCLUSION: It would appear that YB-1 could regulate cell invasion and migration via downregulation of its indirect target coronin-1C. The association between YB-1 and coronin-1C offers a novel approach by which metastasis of breast cancer cells could be targeted and abrogated.
Asunto(s)
Neoplasias de la Mama/genética , Proteínas de Microfilamentos/genética , Invasividad Neoplásica/genética , Proteína 1 de Unión a la Caja Y/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica , HumanosRESUMEN
Despite advances in treatment, the highly metastatic nature of breast tumors has given rise to the urgent need for development of novel therapeutic and prognostic markers. miR-93 is known to regulate the epithelial to mesenchymal transition process and to influence metastatic spread in breast carcinoma, although the exact mechanism(s)/genes involved remain unknown. In the present study, we examined the role of miR-93 in MDA-MB-231 breast cancer cells. Overexpression of mature miR-93-5p in MDA-MB-231 cells decreased cell migratory capability and invasive potential, as well as increased adhesion. In contrast, inhibition of miR-93 induced the opposite effects. miRNA-mRNA target prediction (TargetScan) identified WNK lysine deficient protein kinase 1 (WNK1), which is known to interact with diverse signaling pathways and regulate cell proliferation, survival, angiogenesis and metastasis, as one of the potential targets of miR-93. Furthermore, we showed by luciferase assay that WNK1 is a putative miR-93 target. siRNA mediated silencing of WNK1 also decreased the invasive ability of the cells, suggesting that the effects of miR-93 may be attributed at least in part to decreased WNK1 expression. Further in vivo studies are required to ascertain the miR-93-WNK1-metastasis cascade, that has potential implications in breast cancer therapy.
Asunto(s)
Adhesión Celular/genética , Movimiento Celular/genética , Proliferación Celular/genética , Péptidos y Proteínas de Señalización Intracelular/genética , MicroARNs/genética , Antígenos de Histocompatibilidad Menor/genética , Proteínas Serina-Treonina Quinasas/genética , Neoplasias de la Mama Triple Negativas/patología , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Interferencia de ARN , ARN Interferente Pequeño/genética , Transducción de Señal/genética , Neoplasias de la Mama Triple Negativas/genética , Proteína Quinasa Deficiente en Lisina WNK 1RESUMEN
Nasopharyngeal carcinoma (NPC) is a cancer of the nasopharyngeal epithelium with distinct geographical, ethnic and racial distribution. Several genetic, ethnic and environmental risk factors, have been implicated in nasopharyngeal pathogenesis and of significance, is the Epstein - Barr virus (EBV)- latent infection observed in most patients. Patients with NPC are typically diagnosed only in advanced stages due to non-specific symptoms, and hence, they respond poorly to therapy. Currently, low survival rates, severe complications, tumour metastasis and recurrence following chemo-radiotherapy, delineate the need for better therapeutic options to combat the disease. Recent studies have shown that epigenetic mechanisms such as DNA methylation, histone modifications and microRNAs, which are altered in the EBV genome as well as in the host cells, may underlie the initiation and progression of NPC. Histone acetylation and deacetylation which are mediated by enzymes, namely histone acetyl transferases (HATs) and histone deacetylases (HDACs), are known to regulate gene expression and several cellular processes. HDACs are also involved in maintaining the EBV latent cycle and thus, HDAC inhibitors (HDACi) are potent inducers of EBV reactivation, which is critical for the expression of the lytic proteins, thereby providing novel targets for therapy, as well as mediating enhanced killing of cancer cells, when used alone or along with additional anti-cancer agents in EBV associated malignancies. Recently, three FDA- approved HDACi have been used for the treatment of T-cell lymphoma, while several others are in clinical trials, making histone modifications excellent candidates for targeted therapy. In this review, we summarize the epigenetic mechanisms altered in NPC, with a focus on histone modifications for targeted therapy.
Asunto(s)
Antivirales/farmacología , Inhibidores de Histona Desacetilasas/farmacología , Histonas/metabolismo , Terapia Molecular Dirigida , Neoplasias Nasofaríngeas/metabolismo , Antivirales/química , Epigénesis Genética/efectos de los fármacos , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Inhibidores de Histona Desacetilasas/química , Histona Desacetilasas/metabolismo , Humanos , Neoplasias Nasofaríngeas/tratamiento farmacológico , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/virologíaRESUMEN
With the growing advent of nanotechnology in medicine (therapeutic, diagnostic and imaging applications), cosmetics, electronics, clothing and food industries, exposure to nanomaterials (NMs) is on the rise and therefore exploring their toxic biological effects have gained great significance. In vitro and in vivo studies over the last decade have revealed that NMs have the potential to cause cytotoxicity and genotoxicity although some contradictory reports exist. However, there are only few studies which have explored the epigenetic mechanisms (changes to DNA methylation, histone modification and miRNA expression) of NM-induced toxicity, and there is a scarcity of information and many questions in this area remain unexplored and unaddressed. This review comprehensively describes the epigenetic mechanisms involved in the induction of toxicity of engineered NMs, and provides comparisons between similar effects observed upon exposure to small or nanometer-sized particles. Lastly, gaps in existing literature and scope for future studies that improve our understanding of NM-induced epigenetic toxicity are discussed.
Asunto(s)
Epigénesis Genética/efectos de los fármacos , Nanopartículas/toxicidad , Metilación de ADN/efectos de los fármacos , Histonas/metabolismo , Nanopartículas del Metal/toxicidad , MicroARNs/metabolismoRESUMEN
BACKGROUND: Maternal diabetes alters gene expression leading to neural tube defects (NTDs) in the developing brain. The mechanistic pathways that deregulate the gene expression remain unknown. It is hypothesized that exposure of neural stem cells (NSCs) to high glucose/hyperglycemia results in activation of epigenetic mechanisms which alter gene expression and cell fate during brain development. METHODS AND FINDINGS: NSCs were isolated from normal pregnancy and streptozotocin induced-diabetic pregnancy and cultured in physiological glucose. In order to examine hyperglycemia induced epigenetic changes in NSCs, chromatin reorganization, global histone status at lysine 9 residue of histone H3 (acetylation and trimethylation) and global DNA methylation were examined and found to be altered by hyperglycemia. In NSCs, hyperglycemia increased the expression of Dcx (Doublecortin) and Pafah1b1 (Platelet activating factor acetyl hydrolase, isoform 1b, subunit 1) proteins concomitant with decreased expression of four microRNAs (mmu-miR-200a, mmu-miR-200b, mmu-miR-466a-3p and mmu-miR-466 d-3p) predicted to target these genes. Knockdown of specific microRNAs in NSCs resulted in increased expression of Dcx and Pafah1b1 proteins confirming target prediction and altered NSC fate by increasing the expression of neuronal and glial lineage markers. CONCLUSION/INTERPRETATION: This study revealed that hyperglycemia alters the epigenetic mechanisms in NSCs, resulting in altered expression of some development control genes which may form the basis for the NTDs. Since epigenetic changes are reversible, they may be valuable therapeutic targets in order to improve fetal outcomes in diabetic pregnancy.