This study demonstrates the ability of salinomycin to selectively target "CD133+" cell subpopulations and decrease the malignant traits in colorectal cancer lines.
Rice false smut disease is an increasing threat to rice production in the world. Despite of best efforts, research for the infection of the fungus has yielded equivocal and conflicting results about where and how the infection is initiated and developed. Here we show a stepwise infection pattern and sophisticated regulation during this process. Initial infection occurred on the filaments, which prevented the production of mature pollen thus blocked the pollination. In the following days, the pathogen invaded the stigmas and styles, occasionally the ovaries. Expression analysis indicated that the fungus mimicked a successful fertilization process and enabled the continuous supply of nutrients for fungus to produce false smut balls. The stepwise infection of flower organs and mimicry of ovary fertilization unveiled in this study guided the rice plant into supplying nutrients for false smut ball development and represents a new and unique biological process of host pathogen interactions.
IntroductionMesenchymal stem cell (MSC)-based therapies have had positive outcomes both in animal models of cardiovascular diseases and in clinical patients. However, the number and function of MSCs decline during hypoxia and serum deprivation (H/SD), reducing their ability to contribute to endogenous injury repair. MicroRNA-34a (miR-34a) is originally identified as a TP53-targeted miRNA that modulates cell functions, including apoptosis, proliferation, and senescence via several signaling pathways, and hence is an appealing target for MSC-based therapy for myocardial infarction.MethodsBone marrow-derived MSCs were isolated from 60–80 g male donor rats. Expression levels of miR-34a were determined by qRT-PCR. The roles of miR-34a in regulating cell vitality, apoptosis and senescence were investigated using the cell counting kit (CCK-8) assay, flow cytometric analysis of Annexin V-FITC/PI staining and senescence-associated β-galactosidase (SA-β-gal) staining, respectively. The expression of silent information regulator 1 (SIRT1) and forkhead box class O 3a (FOXO3a) and of apoptosis- and senescence-associated proteins in MSCs were analyzed by western blotting.ResultsThe results of the current study showed that miR-34a was significantly up-regulated under H/SD conditions in MSCs, while overexpression of miR-34a was significantly associated with increased apoptosis, impaired cell vitality and aggravated senescence. Moreover, we found that the mechanism underlying the proapoptotic function of miR-34a involves activation of the SIRT1/FOXO3a pathway, mitochondrial dysfunction and finally, activation of the intrinsic apoptosis pathway. Further study showed that miR-34a can also aggravate MSC senescence, an effect which was partly abolished by the reactive oxygen species (ROS) scavenger, N-acetylcysteine (NAC).ConclusionsOur study demonstrates for the first time that miR-34a plays pro-apoptotic and pro-senescence roles in MSCs by targeting SIRT1. Thus, inhibition of miR-34a might have important therapeutic implications in MSC-based therapy for myocardial infarction.
The relationship between academic achievement and the subjective well-being of elementary school children has received increasing attention. However, previous research on the relationship between these variables has yielded inconsistent conclusions – possibly due to the presence of potential moderating variables. This study investigated the relationship between the academic achievement and the emotional well-being (positive and negative affect) of elementary school children in China and the moderating effect of parent–school communication on this relationship. A total of 419 elementary school students and their parents participated. The elementary students’ positive and negative affect, their academic achievement on both midterm and final examinations of the most recent semester, and the frequency of parent–school communication were assessed. Academic achievement of elementary students was positively correlated with positive affect and negatively correlated with negative affect. Parent–school communication significantly moderated this relationship. Regardless of positive or negative affect, the correlation was only significant in the high parent–school communication group (one standard deviation higher than the mean) and in the mean group, whereas in the low parent–school communication group, no association was observed. These results indicate that parental engagement with school impacts both the academic achievements and subjective well-being of children in China.
False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (teleomorph: Villosiclava virens), is one of the most important diseases affecting rice worldwide. Agrobacterium tumefaciens-mediated transformation was used to identify functional genes in U. virens. In this study, we selected a single-copy insertion mutant T133 with deficiency in producing conidia by screening the T-DNA insertion mutant library of U. virens. The UvPRO1-deletion mutant was successfully obtained after cloning the targeted gene by analysis of the T-DNA insert site of mutant T133. Further research showed that the UvPRO1 mutant was reduced in growth rate and could not produce conidia in PSB medium, while sensitivities to sodium dodecyl sulfate, Congo red, and hyperosmotic stress increased. Moreover, the UvPRO1 deletion mutant hyphae could extend along the surface of spikelets at 1–3 dpi, but mycelia became shriveled and completely lost the ability to infect spikelets at 4 dpi. The relative expression level of UvPRO1 at 8 dpi was more than twice as high as that at 1–2 dpi. These results suggest that UvPRO1 plays a critical role in hyphal growth and conidiation, as well as in stress response and pathogenesis. These findings provide a novel mode of action for the PRO1 protein in fungi and improve the understanding of the function of UvPRO1 in the life cycle of U. virens.
The impact of social economic status (SES) on children's academic outcomes has been well documented. However, the mechanisms underlying this relationship remain poorly understood. Furthermore, the process by which SES relates to academic achievement needs to be studied separately for boys and girls. Using a sample of 598 Chinese children (299 boys, 299 girls) in grades 4 to 6 and their parents, this study examined the process of how family SES, specifically family income and parental education, indirectly relates to children's reading achievement through parental expectation and parental involvement and whether this process differs between boys and girls. The results revealed that parental expectation and specific parental involvement behaviors played critical mediating roles between family SES and reading achievement. Moreover, the exact nature of these links differed by the gender of children. For boys, both the effect of parental education and the effect of family income were partially mediated by parental expectation and parent-child communication orderly. For girls, the effect of parental education was partially mediated by three separate pathways: (1) home monitoring; (2) parent-child communication; and (3) parental expectation followed by parent-child communication, while the effect of family income was fully mediated by parent-child communication. These findings suggest a process through which SES factors are related to children's academic development and identify a context under which these associations may differ. The practical implications of these findings are discussed, along with possible future research directions.
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