The human RecQ helicase BLM is involved in the DNA damage response, DNA metabolism, and genetic stability. Loss of function mutations in BLM cause the genetic instability/cancer predisposition syndrome Bloom syndrome. However, the molecular mechanism underlying the regulation of BLM in cancers remains largely elusive. Here, we demonstrate that the deubiquitinating enzyme USP37 interacts with BLM and that USP37 deubiquitinates and stabilizes BLM, thereby sustaining the DNA damage response (DDR). Mechanistically, DNA double-strand breaks (DSB) promotes ATM phosphorylation of USP37 and enhances the binding between USP37 and BLM. Moreover, knockdown of USP37 increases BLM polyubiquitination, accelerates its proteolysis, and impairs its function in DNA damage response. This leads to enhanced DNA damage and sensitizes breast cancer cells to DNA-damaging agents in both cell culture and in vivo mouse models. Collectively, our results establish a novel molecular mechanism for the USP37–BLM axis in regulating DSB repair with an important role in chemotherapy and radiotherapy response in human cancers. 相似文献
Abstract Thirty-one isolates of Campylobacter pylori , screened for their ability to agglutinate a panel of erythrocyte species, could be divided into two phenotypic groups on the basis of their ability to agglutinate human A and O erythrocytes, a property which correlated strongly with their ability to agglutinate horse and cat erythrocytes. Isolates which agglutinated human red blood cells exhibited a broad-spectrum haemagglutination profile on other red blood cells including dog, goat, guinea-pig, ox, rat and sheep erythrocytes. Agglutination dog, guinea-pig, horse and human erythrocytes by C. pylori was mannose-resistant. Haemagglutination was not inhibited by other saccharides tested nor by two glycoproteins or serine. The bacterial ligand was protease- and heat-sensitive. Neither protease nor neuraminidase treatment of erythrocytes prevented agglutination. 相似文献
High quality clinical practice guidelines (CPGs) can provide clinicians with explicit recommendations on how to manage health conditions and bridge the gap between research and clinical practice. Unfortunately, the quality of CPGs for multiple sclerosis (MS) has not been evaluated.
Objective
To evaluate the methodological quality of CPGs on MS using the AGREE II instrument.
Methods
According to the inclusion and exclusion criteria, we searched four databases and two websites related to CPGs, including the Cochrane library, PubMed, EMBASE, DynaMed, the National Guideline Clearinghouse (NGC), and Chinese Biomedical Literature database (CBM). The searches were performed on September 20th 2013. All CPGs on MS were evaluated by the AGREE II instrument. The software used for analysis was SPSS 17.0.
Results
A total of 27 CPGs on MS met inclusion criteria. The overall agreement among reviews was good or substantial (ICC was above 0.70). The mean scores for each of all six domains were presented as follows: scope and purpose (mean ± SD: 59.05±16.13), stakeholder involvement (mean ± SD: 29.53±17.67), rigor of development (mean ± SD: 31.52±21.50), clarity of presentation (mean ± SD: 60.39±13.73), applicability (mean ± SD: 27.08±17.66), editorial independence (mean ± SD: 28.70±22.03).
Conclusions
The methodological quality of CPGs for MS was acceptable for scope, purpose and clarity of presentation. The developers of CPGs need to pay more attention to editorial independence, applicability, rigor of development and stakeholder involvement during the development process. The AGREE II instrument should be adopted by guideline developers. 相似文献
MicroRNA (miRNA) is critically involved in lipogenesis occurring in various body parts of humans and animals. In this study, to further investigate the role and distribution of miRNA in porcine intramuscular adipose tissue, small RNAs were extracted from Jinhua and Landrace pigs to identify the expression profiles of miRNAs. miRNA expression profiles revealed that 558 miRNAs including 287 known and 271 novel miRNAs were identified, and 220 of them showed differential expression in the pigs. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis suggested that the target genes of the differentially expressed miRNAs were involved in fatty metabolism. In conclusion, the current study reveals the active participation of miRNAs in the regulation of adipogenesis in the intramuscular adipose tissue of Jinhua and Landrace pigs. 相似文献
Over the last century, anthropogenic activities have increased nitrogen (N) deposition considerably, which significantly affects ecosystem processes and has the potential to induce N saturation in the future. The continuous increase in N deposition may cause a non-linear response in soil respiration (Rs), an important component of carbon (C) cycling. However, little is known about N saturation threshold of soil respiration. In this study, we conducted coordinated experiments in four grassland types across northern China with four N addition levels to explore patterns in the Rs saturation threshold. Our results showed that an Rs saturation threshold generally exists in grassland ecosystems in response to N addition gradients. The N saturation threshold of Rs occurred at an average rate of 50 kg N ha−1 yr−1, but varied widely with grassland type; the N saturation threshold occurred at rates of 100, 50, 50, and 25 kg N ha−1 yr−1 in the alpine meadow, meadow steppe, typical steppe, and desert steppe, respectively. Autotrophic respiration (Ra) and heterotrophic respiration (Rh) responded to N addition gradients differently. Ra increased initially and became saturated at a rate of 50 kg N ha−1 yr−1 and declined thereafter. In contrast, Rh decreased monotonically after N addition. Structural equation models further confirmed that the effects of N addition gradients on Rs were primarily determined by the non-linear response of belowground biomass. Interestingly, the compiled global dataset showed that the N saturation threshold of Rs increased with precipitation and soil moisture. These findings indicate that the stimulating effect of N deposition on Rs and Ra might diminish with increasing N deposition in the future, especially in dry grassland ecosystems.