RESUMO
The traditional Chinese medicine Chan Su (toad venom) comprises dried secretions of the ear-side gland of Bufo gargarizans. Chan Su is known for its small molecular components, which include telocinobufagin, marinobufagin, and bufalin, while in other amphibians, studies mainly focus on peptide components. Until recently, no genes expressed in the ear-side gland of B. gargarizans gland had been cloned. In this study, cathelicidin-Bg, a coding sequence of anti-microbial peptide (AMP), was cloned. The predicted amino acid sequence of cathelicidin-Bg was very similar to that from other amphibians, with a 34-amino acid mature peptide predicted in the C-terminus. The functions of this mature peptide were verified by microbe and tumor cell inhibition assays. Our results showed that the mature peptide of cathelicidin-Bg could inhibit the proliferation of Staphylococcus aureus and Pseudomonas aeruginosa. The mature peptide was also shown to selectively inhibit tumor cells. These results indicate that the identified coding sequence represents an active peptide of Chan Su.
Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Anuros/genética , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bufanolídeos , Medicina Tradicional Chinesa , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , CatelicidinasRESUMO
Whether callose deposition is the cause or result of ovule sterility in Medicago sativa remains controversial, because it is unclear when and where changes in callose deposition and dissolution occur during fertile and sterile embryo sac formation. Here, alfalfa spontaneous multi-pistil mutant (mp1) and wild-type plants were used to compare the dynamics of callose deposition during embryo sac formation using microscopy. The results showed that both mutant and wild-type plants experienced megasporogenesis and megagametogenesis, and there was no significant difference during megasporogenesis. In contrast to the wild-type plants, in which the mature embryo sac was observed after three continuous cycles of mitosis, functional megaspores of mutant plants developed abnormally after the second round of mitosis, leading to degeneration of synergid, central, and antipodal cells. Callose deposition in both mutant and wild-type plants was first observed in the walls of megasporocytes, and then in the megaspore tetrad walls. After meiosis, the callose wall began to degrade as the functional megaspore underwent mitosis, and almost no callose was observed in the mature embryo sac in wild-type plants. However, callose deposition was observed in mp1 plants around the synergid, and increased with the development of the embryo sac, and was mainly deposited at the micropylar end. Our results indicate that synergid, central, and antipodal cells, which are surrounded by callose, may degrade owing to lack of nutrition. Callose accumulation around the synergid and at the micropylar end may hinder signals required for the pollen tube to enter the embryo sac, leading to abortion.
Assuntos
Flores/genética , Glucanos/biossíntese , Medicago sativa/genética , Sementes/crescimento & desenvolvimento , Gametogênese Vegetal/genética , Glucanos/genética , Medicago sativa/embriologia , Meiose/genética , Mitose/genética , Mutação , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Tubo Polínico/genética , Tubo Polínico/crescimento & desenvolvimento , Sementes/genéticaRESUMO
Dysregulation of miRNAs is associated with cancer development and progression. For example, aberrant expression of miR-874 has been found in some types of cancer. However, miR-874 expression and its clinical significance in colorectal cancer (CRC) have not yet been explored. The aim of the current study was to explore the effects of miR-874 in CRC tumorigenesis and development. Quantitative reverse-transcription PCR was performed to evaluate miR-874 levels in CRC cell lines and in 135 pairs of primary human CRC specimens and adjacent noncancerous tissues. The association of miR-874 expression with clinicopathological factors and prognosis was also analyzed. Furthermore, the effects of miR-874 on the biological behavior of CRC cells in vitro were investigated. Our results revealed that miR-874 expression was significantly downregulated in CRC cancer tissues and cell lines. Decreased miR-874 expression was significantly associated with larger tumor size, deeper invasion depth, and advanced TNM stage in vivo. Additionally, low miR-874 expression in CRC was an independent predictor of poor survival. Moreover, overexpression of miR-874 inhibited cell proliferation, invasion, and migration, and promoted cell apoptosis of the SW620 CRC cell line in vitro. Taken together, these findings indicate that miR-874 may act as a tumor suppressor in CRC, and may serve as a novel therapeutic target for miR-based therapy.
RESUMO
Powdery mildew (Pm) is one of the most harmful diseases in wheat. Three Pm-resistance genes, Pm3, Pm21, and Pm8, have been cloned but most Pm3/Pm8 alleles have lost their resistance to Pm in hexaploid wheat. In this study, a new Pm3 homolog gene (TmPm3) was isolated from Triticum monococcum L. using a homology-based cloning strategy, being the first report of a functional Pm3 homolog gene from a diploid wheat species. The transient expression of TmPm3 in leaf epidermal cells showed that over-expressed TmPm3 could significantly inhibit the penetration of Blumeria graminis f. sp tritici conidia spores and the formation of haustoria. Sequence analysis of Pm3 alleles shed new light on the evolution of Pm3 genes, providing a better understanding of the molecular basis of disease resistance. This study also suggested that homology-based cloning of resistance genes is a feasible method for the isolation of functional resistance genes from wheat germplasm.
Assuntos
Evolução Molecular , Genes de Plantas , Imunidade Vegetal/genética , Triticum/genética , Ascomicetos/patogenicidade , Clonagem Molecular , Triticum/imunologia , Triticum/microbiologiaRESUMO
Venous thromboembolism (VTE) is a multifactorial disorder involving both acquired and genetic risk factors. The common genetic factors in Western populations have been studied and reported for several decades, while studies on Asian populations are relatively scarce. Evidence suggests that the prevalence and genetic risk factors of VTE vary significantly among ethnic populations. In this review, we summarize the common genetic risk factors of VTE in both Western and Asian populations. In addition to the development of DNA sequencing technology, genome-wide association studies have many advantages and are becoming more important in identifying new genetic risk factors and susceptible loci. They can therefore help in the prediction and prevention of VTE.
Assuntos
Predisposição Genética para Doença , Tromboembolia Venosa/genética , Povo Asiático/genética , Etnicidade/genética , Estudo de Associação Genômica Ampla , Humanos , Prevalência , Fatores de Risco , Análise de Sequência de DNA , Tromboembolia Venosa/epidemiologia , População Branca/genéticaRESUMO
SQUAMOSA promoter-binding protein-like (SPL) proteins play crucial roles in plant growth, development, and responses to environmental stressors. The peanut (Arachis hypogaea L.) is a globally important oil crop. In this study, we cloned the full-length cDNA of 15 SPLs in the peanut by transcriptome sequencing and rapid amplification of cDNA ends, and analyzed their genomic DNA sequences. cDNA lengths varied significantly, from 369 to 3102 bp. The SBP domain of the peanut SPL proteins was highly conserved compared to SPLs in other plant species. Based on their sequence similarity to SPLs from other plant species, the peanut SPLs could be grouped into five subgroups. In each subgroup, lengths of individual genes, conserved motif numbers, and distribution patterns were similar. Seven of the SPLs were predicted to be targets of miR156. The SPLs were ubiquitously expressed in the roots, leaves, flowers, gynophores, and seeds, with different expression levels and accumulation patterns. Significant differences in the expression of most of the SPLs were observed between juvenile and adult leaves, suggesting that they are involved in developmental regulation. Dynamic changes occurred in transcript levels at stage 1 (aerial grown green gynophores), stage 2 (gynophores buried in soil for about three days), and stage 3 (gynophores buried in soil for about nine days with enlarged pods). Possible roles that these genes play in peanut pod initiation are discussed.
Assuntos
Arachis/metabolismo , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Arachis/genética , Sequência de Bases , Regulação da Expressão Gênica no Desenvolvimento , Genes de Plantas , MicroRNAs , Especificidade de Órgãos , Filogenia , Componentes Aéreos da Planta/genética , Componentes Aéreos da Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , RNA Mensageiro , Alinhamento de Sequência , Análise de Sequência de DNA , Análise de Sequência de RNA , Fatores de Transcrição/química , Fatores de Transcrição/metabolismoRESUMO
We explored the molecular mechanism of the regulation of vacuolar-type-H+-ATPase B1 (VHAB1) in elvers in the response to salinity. The full-length cDNA of VHAB1 in Anguilla marmorata (designated as AmVHAB1), which was 1741 base pairs (bp) in length, was found to encompass a 1512-bp open reading frame encoding a polypeptide with 503 amino acids (55.9 kDa), an 83-bp 5'-untranslated region, and a 146-bp 3'-untranslated region. The mRNA and protein expression levels of AmVHAB1 in the gill were evaluated at different time points (0, 1, 3, 6, 12, 24, 48, 72, and 96 h, and 15 days) during the exposure to various salinity levels (0, 10, and 25). The results indicated that the expression levels of AmVHAB1 mRNA in the gill significantly increased and reached the highest level at 1 h exposure in the brackish water (BW, 10) group and at 6 h exposure in the seawater (SW, 25) group. The salinity level affected the relative expression level of AmVHAB1 mRNA in the gill, which was increased by approximately 44-fold in the SW group when compared with that in fresh water. Immunoblotting analysis showed that VHA expression was significantly higher in the BW and SW groups, with the highest expression level was detected at 96 h exposure. We found that the AmVHAB1 gene in elvers from A. marmorata plays an important role in the adaptation to seawater.
Assuntos
Anguilla/genética , Brânquias/enzimologia , ATPases Vacuolares Próton-Translocadoras/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Regulação Enzimológica da Expressão Gênica , Immunoblotting , Dados de Sequência Molecular , Filogenia , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Águas Salinas , Água do Mar , Fatores de Tempo , ATPases Vacuolares Próton-Translocadoras/química , ATPases Vacuolares Próton-Translocadoras/metabolismoRESUMO
To investigate the effect of treatment with resveratrol combined with imatinib mesylate on human chronic myelogenous leukemia K562 cell growth inhibition and apoptosis, in vitro cultured human chronic myelogenous leukemia K562 cells were incubated with different concentrations of resveratrol and imatinib mesylate when the cells were in the logarithmic phase. Next, the cell growth inhibition was evaluated using the MTT assay and cellular morphology observation. Apoptosis was determined using Annexin V fluorescein isothiocyanate/propidium iodide double staining. The results demonstrated that treatment with resveratrol (concentration-dependent) and imatinib mesylate showed significantly greater inhibition of K562 cell growth and a higher apoptosis rate of K562 cells than imatinib mesylate medication alone and the control group (P < 0.01). The imatinib mesylate medication alone group showed significant inhibition of K562 cell growth and apoptosis rate of K562 cells compared to the control group (P < 0.01). Our findings indicate that imatinib mesylate and resveratrol are potent drug treatments for human chronic myelogenous leukemia, offering a promising means of inhibiting cell growth and apoptosis.
Assuntos
Proliferação de Células/efeitos dos fármacos , Mesilato de Imatinib/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Estilbenos/administração & dosagem , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , ResveratrolRESUMO
The influence of ruminal acidosis on ruminal microbiology and metabolite production has received considerable attention, but little is known regarding the systemic manifestations that arise from ruminal acidosis. Lipopolysaccharide (LPS) is released in the gastrointestinal tract upon ingestion of high-grain or high-fat diets, and it has been implicated in the etiology of multiple energy- and lipid-related metabolic disturbances in ruminants. The liver plays a crucial role in the acute phase response to intruding pathogens. The effect of blood LPS in subacute ruminal acidosis on lipid metabolism in the liver has not been established. In this study, cell cultures were photographed using an inverted microscope. We observed that hepatocytes changed their morphologies from irregular triangle to circular (contraction) shapes; the number of contracted cells increased with the increasing LPS doses. This suggests that LPS can promote cell contraction and take off the wall, ultimately leading to cell apoptosis. With changes in LPS exposure, hepatocyte number also changes. We explored lipid metabolism in the liver using quantitative reverse transcription-polymerase chain reaction to detect the expression of key lipid metabolism enzymes in hepatocytes. We found that Toll-like receptor 4 signaling pathway mediated by LPS could attenuate mRNA expression of fatty acid synthesis genes and increase the expression of fatty acid transport genes in primary hepatocytes following LPS treatment in dairy cows.
Assuntos
Expressão Gênica/imunologia , Hepatócitos/metabolismo , Metabolismo dos Lipídeos , Lipopolissacarídeos/farmacologia , Animais , Bovinos , Forma Celular/imunologia , Células Cultivadas , Feminino , Regulação da Expressão Gênica/imunologia , Hepatócitos/imunologia , Cultura Primária de Células , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Receptor 4 Toll-Like/metabolismoRESUMO
Genetic mutations in microRNA gene can alter expression, which may interact to increase the risk of developing various diseases, including hepatitis B. However, published results are inconclusive or ambiguous. The aim of this review and meta-analysis is to more precisely estimate the association between polymorphisms in microRNA genes and hepatitis B risk. A digital search was performed of the MEDLINE EMBASE, CNKI, and CBM databases to identify relevant articles published up to February 18, 2014. Ten case-control studies were included, with a total of 6042 patients with hepatitis B and 6834 healthy controls. Nine single-nucleotide polymorphisms in the miRNA gene were examined, including miR-34b/c [rs4938723 (T>C)], miR-196a-2 [rs11614913 (C>T)], miR-146a [rs2910164 (G>C)], miR-499 [rs3746444 (T>C)], miR-122 [rs3783553 (ins/del)], miR-149 [rs2292832 (C>T)], miR-106b-25 [rs999885 (A>G)], miR-let-7c [rs6147150 (ins/del)], and miR-218 [rs11134527 (A>G)]. The meta-analysis results indicated that the miR-196a-2*T, miR-122*del, miR-106b-25*A, and miR-let-7c*del alleles/carriers increase the risk of hepatitis B among the Asian population. However, the miR-146a, miR- 499, miR-149, miR-218, and miR-34b/c polymorphisms may not be linked with the risk of hepatitis B. Further investigations are warranted to determine the exact associations between microRNA mutations and hepatitis B susceptibility.