RESUMEN
Flying insects rely mainly upon visual motion to detect and track objects. There has been a lot of research on fly inspired algorithms for object detection, but few have been developed based on visual motion alone. One of the daunting difficulties is that the neural and circuit mechanisms underlying the foreground-background segmentation are still unclear. Our previous modeling study proposed that the lobula held parallel pathways with distinct directional selectivity, each of which could retinotopically discriminate figures moving in its own preferred direction based on relative motion cues. The previous model, however, did not address how the multiple parallel pathways gave the only detection output at their common downstream. Since the preferred directions of the pathways along either horizontal or vertical axis were opposite to each other, the background moving in the opposite direction to an object also activated the corresponding lobula pathway. Indiscriminate or ungated projection from all the pathways to their downstream would mix objects with the moving background, making the previous model fail with non-stationary background. Here, we extend the previous model by proposing that the background motion-dependent gating of individual lobula projections is the key to object detection. Large-field lobula plate tangential cells are hypothesized to perform the gating to realize bioinspired background subtraction. The model is shown to be capable of implementing a robust detection of moving objects in video sequences with either a moving camera that induces translational optic flow or a static camera. The model sheds light on the potential of the concise fly algorithm in real-world applications.
Asunto(s)
Percepción de Movimiento , Animales , Percepción de Movimiento/fisiología , Biomimética/métodos , Algoritmos , Simulación por Computador , Insectos/fisiología , Modelos Neurológicos , Vías Visuales/fisiología , Dípteros/fisiologíaRESUMEN
The transformation of myelodysplastic syndrome (MDS) into acute myeloid leukemia (AML) poses a significant clinical challenge. The trimethylation of H3 on lysine 27 (H3K27me3) methylase and demethylase pathway is involved in the regulation of MDS progression. The present study investigated the functional mechanisms of the MEK/ERK and PI3K/AKT pathways in the MDStoAML transformation. MDSAML mouse and SKM1 cell models were first established and this was followed by treatment with the MEK/ERK pathway inhibitor, U0126, the PI3K/AKT pathway inhibitor, Ly294002, or their combination. H3K27me3 methylase, enhancer of zeste homolog (EZH)1, EZH2, demethylase Jumonji domaincontaining protein3 (JMJD3) and ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) and H3K27me3 protein levels were determined using western blot analysis. Cell viability, cycle distribution and proliferation were assessed using CCK8, flow cytometry, EdU and colony formation assays. The ERK and AKT phosphorylation levels in clinical samples and established models were determined, and SKM1 cell behaviors were assessed. The levels of H3K27me3 methylases and demethylases and distalless homeobox 5 (DLX5) were measured. The results revealed that the ERK and AKT phosphorylation levels were elevated in patients with MDS and MDSAML, and in mouse models. Treatment with U0126, a MEK/ERK pathway inhibitor, and Ly294002, a PI3K/AKT pathway inhibitor, effectively suppressed ERK and AKT phosphorylation in mice with MDSAML. It was observed that mice with MDS treated with U0126/Ly294002 exhibited reduced transformation to AML, delayed disease transformation and increased survival rates. Treatment of the SKM1 cells with U0126/Ly294002 led to a decrease in cell viability and proliferation, and to an increase in cell cycle arrest by suppressing ERK/PI3K phosphorylation. Moreover, treatment with U0126/Ly294002 downregulated EZH2/EZH1 expression, and upregulated JMJD3/UTX expression. The effects of U0126/Ly294002 were nullified when EZH2/EZH1 was overexpressed or when JMJD3/UTX was inhibited in the SKM1 cells. Treatment with U0126/Ly294002 also resulted in a decreased H3K27me3 protein level and H3K27me3 level in the DLX5 promoter region, leading to an increased DLX5 expression. Overall, the findings of the present study suggest that U0126/Ly294002 participates in MDSAML transformation by modulating the levels of H3K27me3 methylases and demethylases, and regulating DLX5 transcription and expression.
Asunto(s)
Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Humanos , Ratones , Animales , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Histonas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Síndromes Mielodisplásicos/tratamiento farmacológico , Leucemia Mieloide Aguda/tratamiento farmacológicoRESUMEN
We have identified that NUDT21 plays a vital role in MDS transformations, while the transcription factor RUNX1 is essential for normal hematopoiesis, which is a high expression in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), and we aim to explore the linkage between the two genes and new pathways for MDS transformation to AML. Prediction of RUNX1 expression levels and its relationship with NUDT21 in AML and MDS patients was performed using bioinformatics techniques and validated in patients. Using lentiviral packaging technology, NUDT21 knockdown and overexpression models were developed in AML and MDS cell lines. These models were validated using quantitative polymerase chain reaction (qPCR) and western blotting. The cell cycle, apoptosis, differentiation, and cytokines were examined by flow cytometry, CCK-8 analyzed proliferation, and the intracellular localization of NUDT21 and RUNX1 was examined by immunofluorescence. mRNA transcriptome sequencing was performed on THP-1, MUTZ-1, and Dapars analyzed SKM-1 cell lines and the sequencing data to observe the knockdown effect of NUDT21 on RUNX1. qPCR and western blot revealed a positive correlation between NUDT21 and RUNX1; both were located in the nucleus. Overexpression of NUDT21 reduced apoptosis, promoted cell proliferation, and possibly increased the invasive ability of cells. It also altered the APA site in the RUNX1 3'-UTRs region. NUDT21 regulates RUNX1 gene expression and promotes AML transformation in MDS through an APA mechanism.
Asunto(s)
Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Humanos , Apoptosis , Proliferación Celular , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genéticaRESUMEN
Myelodysplastic syndrome (MDS) is characterized by clonal hematopoiesis and impaired differentiation, and may develop to acute myeloid leukemia (AML). We explored the mechanism of histone methyltransferase EZH2/EHMT2 during the transformation of MDS into AML. Expression of EZH2/EHMT2 in patients and NHD13 mice was detected. EZH2 and EHMT2 were silenced or overexpressed in SKM-1 cells. The cell proliferation and cycle were evaluated. Levels of DLX5, H3K27me3, and H3K9me2 in SKM-1 cells were detected. Binding of DLX5 promoter region to H3K27me3 and H3K9me2 was examined. Levels of H3K27me3/H3K9me2 were decreased by EZH2/EHMT2 inhibitor (EPZ-6438/BIX-01294), and changes of DLX5 expression and cell proliferation were observed. EZH2 was poorly expressed in MDS patients but highly expressed in MDS-AML patients. EHMT2 was promoted in both MDS and MDS-AML patients. EZH2 expression was reduced and EHMT2 expression was promoted in NHD13 mice. NHD13 mice with overexpressing EZH2 or EHMT2 transformed into AML more quickly. Intervention of EZH2 or EHMT2 inhibited SKM-1 cell proliferation and promoted DLX5 expression. When silencing EZH1 and EZH2 in SKM-1 cells, the H3K27me3 level was decreased. EZH2 silencing repressed the proliferation of SKM-1 cells. Transcription level of DLX5 in SKM-1 cells was inhibited by H3K27me3 and H3K9me2. Enhanced DLX5 repressed SKM-1 cell proliferation. In conclusion, EZH2/EHMT2 catalyzed H3K27me3/H3K9me2 to inhibit the transcription of DLX5, thus promoting the transformation from MDS to AML.
RESUMEN
MicroRNAs play important roles in the initiation and progression of acute myeloid leukemia (AML). This study aimed to detect serum miR-203 expression levels in AML and explore its potential clinical significance. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed to measure the serum miR-203 levels in 134 patients with AML and 70 healthy controls. The results demonstrated that serum miR-203 expression was significantly reduced in AML patients compared with healthy controls. Receiver operating characteristic curve (ROC) analysis revealed miR-203 could distinguish AML cases from normal controls. Low serum miR-203 levels were associated with worse clinical features, as well as poorer overall survival and relapse free survival of AML patients. Moreover, multivariate analysis confirmed low serum miR-203 expression to be an independent unfavorable prognostic predictor for AML. The bioinformatics analysis showed that the downstream genes and pathways of miR-203 was closely associated with tumorigenesis. Downregulation of miR-203 in AML cell lines upregulated the expression levels of oncogenic promoters such as CREB1, SRC and HDAC1. Thus, these findings demonstrated that serum miR-203 might be a promising biomarker for the diagnosis and prognosis of AML.
RESUMEN
Multiple myeloma (MM) is one of the most common causes of mortality from hematological malignancy in China. Recent studies have demonstrated that cancerous inhibitor of protein phosphatase 2A (CIP2A) may exhibit a role in promoting the growth of cancer; however, the function of CIP2A in MM remains unknown. In the present study, the expression and molecular mechanism underlying the effects of CIP2A in patients with MM and in MM cell lines were elucidated. Firstly, the expression of CIP2A was detected in patients with MM and in MM cell lines by reverse transcriptionquantitative polymerase chain reaction. Furthermore, silencing of CIP2A with short hairpin RNA was performed in MM cells, and the impact on the proliferation and apoptosis of RPMI8226 cells was analyzed (as endogenous CIP2A is highly expressed in RPMI8226 cell lines compared with other cells). CIP2A was significantly elevated in patients with MM and in MM cell lines, and silencing of CIP2A could inhibit the proliferation ability of RPMI8226 cells in vitro. In addition, CIP2A knockdown induced apoptosis and led to substantial reduction of cMyc protein levels in MM cell lines. This study suggested that CIP2A inhibition may provide a promising therapeutic strategy for patients with MM.
Asunto(s)
Apoptosis/genética , Autoantígenos/genética , Expresión Génica , Proteínas de la Membrana/genética , Mieloma Múltiple/genética , Autoantígenos/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Técnicas de Silenciamiento del Gen , Humanos , Péptidos y Proteínas de Señalización Intracelular , Proteínas de la Membrana/metabolismo , Mieloma Múltiple/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , Transducción de SeñalRESUMEN
This study investigated the cytotoxic effect of uvangoletin on HL-60 cells, and the effects of uvangoletin on myelosuppression, leucopenia, gastrointestinal tract disturbances and the possible cytotoxic mechanisms by using CCK-8, flow cytometry, western blot, xenograft, cyclophosphamide-induced leucopenia, copper sulfate-induced emesis and ethanol-induced gastric mucosal lesions assays. The results of CCK-8, flow cytometry and western blot assays indicated that uvangoletin showed the cytotoxic effect on HL-60 cells and induced the apoptosis of HL-60 cells by downregulating the expression levels of anti-apoptotic proteins (Survivin, Bcl-xl and Bcl-2), upregulating the expression levels of pro-apoptotic proteins (Smac, Bax, Bad, c-caspase-3 and c-caspase-9), and promoting the release of cytochrome c from mitochondria to cytoplasm. Further, the results of xenograft assay suggested that uvangoletin inhibited the HL-60-induced tumor growth without adverse effect on body weight of nude mice in vivo by regulating the expression levels of above apoptotic proteins. The results indicated that the reductions of WBCs count and thighbone marrow granulocytes percentage in cyclophosphamide-induced leucopenia assay, the incubation period and number of emesis in copper sulfate-induced emesis assay and the gastric mucosal lesions in ethanol-induced gastric mucosal lesions assay were not exacerbated or reversed by uvangoletin. In conclusion, the research preliminarily indicated that uvangoletin induced apoptosis of HL-60 cells in vitro and in vivo without adverse reactions of myelosuppression, leucopenia and gastrointestinal tract disturbances, and the pro-apoptotic mechanisms may be related to mitochondria-mediated apoptotic pathway.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Mitocondrias/efectos de los fármacos , Animales , Antineoplásicos Fitogénicos/uso terapéutico , Antineoplásicos Fitogénicos/toxicidad , Proteínas Reguladoras de la Apoptosis/biosíntesis , Proteínas Reguladoras de la Apoptosis/genética , Enfermedades de la Médula Ósea/inducido químicamente , Columbidae , Sulfato de Cobre/toxicidad , Ciclofosfamida/toxicidad , Medicamentos Herbarios Chinos/uso terapéutico , Medicamentos Herbarios Chinos/toxicidad , Etanol/toxicidad , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Leucopenia/inducido químicamente , Ratones , Ratones Desnudos , Náusea/inducido químicamente , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Distribución Aleatoria , Ratas , Úlcera Gástrica/inducido químicamente , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
This study aimed to develop a specific and sensitive method for the rapid detection of NF-κB activity in pancreatic tissue. Male Wistar rats were randomly divided into two groups: (1) 16 rats in the acute pancreatitis (AP) group received retrograde injection of 5% sodium taurocholate (STC) into the biliopancreatic duct, and (2) 16 rats in the Control group received saline. NF-κB activation in rat pancreatic acinar cells was assessed by flow cytometry (FCM). We found that the NF-κB activity in the AP group significantly increased at 1.5 h (29.80%±7.83), had a peak at 3 h (65.17%±13.22), and then decreased gradually to 12 h time point, close to the level after 1.5 h stimulation of STC. The NF-κB activity of the Control group did not significantly vary at different time points (P>0.05). FCM is a specific and sensitive assay for the rapid detection of NF-κB activity in pancreatic tissue.