RESUMO
Heterosis, or enhancement through outbreeding, is one of the most promising approaches for increasing crop yield. Male sterility (MS), which promotes heterosis, has been widely applied in hybrid crop production. Medicago truncatula is a model legume species and is closely related to M. sativa, an important legume forage plant. Although the molecular mechanisms of MS in M. truncatula and M. sativa remain unclear, several studies of MS have been conducted in Arabidopsis thaliana. Previous research has shown that MS is associated with the destruction of tapetal cell layers. Disruption of tapetum developmental processes may result in pollen abortion. In an effort to identify genes useful for breeding in M. sativa, we identified MS related genes in M. truncatula using BLAST and homology to A. thaliana genes. In this study, we identified 63 tapetum specific male sterility (TSMS) related genes. The length of TSMS genes varied from 225 to 3747 bp. We identified 15 conserved domains and 8 cis-elements associated with TSMS related genes. Analysis of the phylogenetic relationships among these genes allowed them to be classified into three groups, MtTsms A, MtTsms B, and MtTsms C. Expression analyses revealed that these genes may be involved in developmental processes and response to abiotic stress.
Assuntos
Medicago truncatula/genética , Infertilidade das Plantas/genética , Sequência de Aminoácidos , Arabidopsis/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Vigor Híbrido/genética , Medicago sativa/genética , Filogenia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genéticaRESUMO
Osteoporosis poses a major public health threat in aging societies. Adipose-derived stem cells (ADSCs) are multipotent adult stem cells that have the ability to yield mesenchymal stem cells, and have the potential to undergo osteogenesis and bone regeneration. Bone morphogenetic proteins (BMPs) have been demonstrated to upregulate bone gene expression after mechanical injury and to improve bone injury repair. This study aimed to produce BMP-2 expression in ADSCs by using lentiviral vectors. Subcutaneous adipose tissue from 4-week-old male Sprague-Dawley rats was used. Oil red O staining was used to detect adipocyte formation from ADSCs. Induction of ADSC osteogenesis was confirmed with Alizarin red S staining. The recombinant lenti-hBMP-2/neo was constructed to infect ADSCs, BMP-2 expression was measured by immunoblotting analysis, and cellular alkaline phosphatase levels were examined. We found that >70% of ADSC cells could be induced to differentiate into osteocytes or adipocytes. Under osteogenic induction, ADSCs showed increased intracellular calcium deposition, the formation of calcium tubercles, and the disappearance of cellular structures in calcium tubercles. After infection of ADSCs by lenti-hBMP-2/neo, BMP-2 was expressed after doxycycline induction. We, thus, conclude that ADSCs maintain vigorous growth ex vivo and possess stem cell-like properties. When infected with lenti-hBMP-2/neo, ADSCs can be induced to promote BMP-2 expression.
Assuntos
Tecido Adiposo/citologia , Células-Tronco Adultas/citologia , Proteína Morfogenética Óssea 2/metabolismo , Condrogênese , Células-Tronco Adultas/metabolismo , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Animais , Proteína Morfogenética Óssea 2/genética , Vetores Genéticos , Lentivirus/genética , Masculino , Osteogênese , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Endothelial thrombomodulin (TM) is critically involved in anticoagulation, anti-inflammation, cytoprotection and normal fetal development. Tumor necrosis factor alpha (TNFα) suppresses TM expression. OBJECTIVE: TNFα has been shown to down-regulate TM partly via activation of nuclear factor kappa B (NF-κB). However, because the TM promoter lacks an NF-κB binding site, the direct involvement of NF-κB has been controversial. We investigated the role of the upstream regulatory serine kinase, inhibitory kappa-B kinase-ß (IKKß), in TM expression and function with or without TNFα treatment. METHODS: Inhibition of IKKß was achieved by specific chemical inhibitors, siRNA or shRNA. TM expression was assessed by qRT-PCR, Western blot, flow cytometry, luciferase reporter assay and chromatin immune-precipitation (ChIP) assay. TM function was estimated by generation of activated protein C (APC). NF-κB activation was determined by immunocytochemistry. RESULTS AND CONCLUSIONS: IKKß inhibition increased TM expression and function, and attenuated TNFα-mediated TM down-regulation. In contrast, inhibition of downstream canonical NF-κB protein family members p50 and p65 (RelA) failed to up-regulate TM expression and did not affect IKKß inhibition-mediated TM over-expression. However, knockdown of cRel and RelB, family members of the canonical and non-canonical NF-κB pathway, respectively, resulted in TM over-expression. IKKß inhibition caused over-expression, increased promoter activity and enhanced binding of Krüppel-like factor 2 (Klf2) to the TM promoter, which positively regulates TM expression. Finally, knockdown of Klf2 completely attenuated IKKß inhibition-mediated TM up-regulation. We conclude that IKKß regulates TM in a Klf2-dependent manner.
Assuntos
Endotélio Vascular/metabolismo , Regulação da Expressão Gênica , Quinase I-kappa B/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , NF-kappa B/metabolismo , Trombomodulina/metabolismo , Anti-Inflamatórios/química , Anticoagulantes/química , Sítios de Ligação , Imunoprecipitação da Cromatina , Regulação para Baixo , Citometria de Fluxo , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Proteína C/metabolismo , RNA Interferente Pequeno/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We sequenced the complete mitochondrial genome (mitogenome) of Cheirotonus jansoni (Coleoptera: Scarabaeidae), an endangered insect species from Southeast Asia. This long legged scarab is widely collected and reared for sale, although it is rare and protected in the wild. The circular genome is 17,249 bp long and contains a typical gene complement: 13 protein-coding genes, 2 rRNA genes, 22 putative tRNA genes, and a non-coding AT-rich region. Its gene order and arrangement are identical to the common type found in most insect mitogenomes. As with all other sequenced coleopteran species, a 5-bp long TAGTA motif was detected in the intergenic space sequence located between trnS(UCN) and nad1. The atypical cox1 start codon is AAC, and the putative initiation codon for the atp8 gene appears to be GTC, instead of the frequently found ATN. By sequence comparison, the 2590-bp long non-coding AT-rich region is the second longest among the coleopterans, with two tandem repeat regions: one is 10 copies of an 88-bp sequence and the other is 2 copies of a 153-bp sequence. Additionally, the A+T content (64%) of the 13 protein-coding genes is the lowest among all sequenced coleopteran species. This newly sequenced genome aids in our understanding of the comparative biology of the mitogenomes of coleopteran species and supplies important data for the conservation of this species.
Assuntos
Besouros/genética , Genoma de Inseto , Genoma Mitocondrial , Animais , Sequência de Bases , Besouros/classificação , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Análise de Sequência de DNARESUMO
OBJECTIVE: This retrospective analysis evaluates the clinical outcomes of extensive-stage small cell lung cancer (SCLC) patients who received second-line chemotherapy after platinum-based first-line chemotherapy, especially focusing on efficacy and toxicity between single-agent and combination chemotherapy. METHODS: We retrospectively reviewed 193 patients who received second-line chemotherapy for extensive-stage SCLC. Patients relapsing or progressing beyond 90 days were defined as sensitive recurrence patients, and below 90 days as refractory recurrence patients. Survival curves were plotted using the Kaplan-Meier method. The Cox proportional hazard model was used for multivariate analysis. RESULTS: 138 patients received combination chemotherapy and 55 received single-agent treatment. The objective response rate (ORR) was 25.4 % in the combination group and 9.1 % in the single-agent group (p = 0.012). The disease control rate (DCR) was 65.2 and 34.5 %, respectively, (p < 0.001). The progression-free survival (PFS) was 3.80 months in the combination group and 2.13 months in the single-agent group (p = 0.001). In the sensitive recurrence group, the median PFS was 3.80 months in combination group and 3.23 months in single-agent group (p = 0.092). In the refractory recurrence group, the median PFS was 2.83 and 1.30 months, respectively (p = 0.001). The grade III/IV toxicity in single-agent group is much lower than the combination group (56.4 vs. 74.6 %, p = 0.013). CONCLUSION: Our retrospective data suggest a potential role of prolonging the PFS for combination treatment in extensive-stage SCLC second-line treatment, especially for the refractory recurrence patients, but with more toxicity as compared to single-agent.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Terapia de Salvação , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Idoso , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Docetaxel , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Irinotecano , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Paclitaxel/administração & dosagem , Platina/administração & dosagem , Prognóstico , Estudos Retrospectivos , Carcinoma de Pequenas Células do Pulmão/patologia , Taxa de Sobrevida , Taxoides/administração & dosagem , Topotecan/administração & dosagemRESUMO
Proinflammatory and immunoregulatory products from C3 play a major role in phagocytosis, respiratory burst, and airways inflammation. C3 is critical in adaptive immunity; studies in mice deficient in C3 demonstrate that features of asthma are significantly attenuated in the absence of C3. To test the hypothesis that the C3 gene on chromosome 19p13.3-p13.2 contains variants associated with asthma and related phenotypes, we genotyped 25 single nucleotide polymorphism (SNP) markers distributed at intervals of approximately 1.9 kb within the C3 gene in 852 African Caribbean subjects from 125 nuclear and extended pedigrees. We used the multiallelic test in the family-based association test program to examine sliding windows comprised of 2-6 SNPs. A five-SNP window between markers rs10402876 and rs366510 provided strongest evidence for linkage in the presence of linkage disequilibrium for asthma, high log[total IgE], and high log[IL-13]/[log[IFN-gamma] in terms of global P-values (P = 0.00027, 0.00013, and 0.003, respectively). A three-SNP haplotype GGC for the first three of these markers showed best overall significance for the three phenotypes (P = 0.003, 0.007, 0.018, respectively) considering haplotype-specific tests. Taken together, these results implicate the C3 gene as a priority candidate controlling risk for asthma and allergic disease in this population of African descent.
Assuntos
Asma/genética , População Negra , Complemento C3/genética , Predisposição Genética para Doença , Barbados/etnologia , População Negra/etnologia , Região do Caribe/etnologia , Variação Genética , Genótipo , Humanos , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Toxicity bioassays based on survival were carried out with cells of the marine dinoflagellate Gonyaulax polyedra exposed to mercury (Hg2+ ), cadmium (Cd2+), lead (Pb2+) and copper (Cu2+). The toxicity scale of these metals found was Hg2+ > Cu2+ > Cd2+ > Pb2+. Cells exposed to metals promptly underwent encystment, which is an important strategy for surviving metal exposure. Following 48 h exposure to Cu2+, complete excystment occurred within 96 h after reinoculation of cells in fresh metal-free media, and with Pb2+ partial recovery occurred in that time. Bioluminescence was affected by the metals in a dose-dependent manner primarily by increasing the frequency of flashing, but the glow emission was also altered with acute Cu2+ and Pb2+ treatments. Several physiological processes in G. polyedra are under circadian control. Chronic exposures to metals caused no substantial alterations in the circadian rhythm of bioluminescence glow, indicating that the biological clock of this dinoflagellate is not sensitive to these metals at the concentrations tested.
Assuntos
Cádmio/toxicidade , Cobre/toxicidade , Dinoflagellida/efeitos dos fármacos , Chumbo/toxicidade , Mercúrio/toxicidade , Animais , Relógios Biológicos/efeitos dos fármacos , Relógios Biológicos/fisiologia , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/fisiologia , Dinoflagellida/fisiologia , Relação Dose-Resposta a Droga , Medições Luminescentes , Testes de Toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
A practical triple energy window technique (TEW) is proposed, which is based on using the information in two lower energy windows and one single calibration, to estimate the scatter within the photopeak window. The technique is basically a conventional dual-window technique plus a modification factor, which can partially compensate object-distribution dependent scatters. The modification factor is a function of two lower scatter windows of both the calibration phantom and the actual object. In order to evaluate the technique, a Monte Carlo simulation program, which simulates the PENN-PET scanner geometry, was used. Different phantom activity distributions and phantom sizes were tested to simulate brain studies, including uniform and nonuniform distributions. The results indicate that the TEW technique works well for a wide range of activity distributions and object sizes. The comparisons between the TEW and dual window techniques show better quantitative accuracy for the TEW, especially for different phantom sizes. The technique is also applied to experimental data from a PENN-PET scanner to test its practicality.
RESUMO
The authors propose a new 2-D point source scattering deconvolution method. The cross-plane scattering is incorporated into the algorithm by modeling a scattering point source function. In the model, the scattering dependence on axial and transaxial directions is reflected in the exponential fitting parameters, and these parameters are directly estimated from a limited number of measured point response functions. The results comparing the standard in-plane line source deconvolution to the cross-plane point source deconvolution show that for a small source the former technique overestimates the scatter fraction in the plane of the source and underestimates the scatter fraction in adjacent planes. In addition, the authors also propose a simple approximation technique for deconvolution.