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The transforming growth factor-β (TGF-β) signalling pathway participates in various biological processes. Dysregulation of Smad4, a central cellular transducer of TGF-β signalling, is implicated in a wide range of human diseases and developmental disorders. However, the mechanisms underlying Smad4 dysregulation are not fully understood. Using a functional screening approach based on luciferase reporter assays, we identified 39 microRNAs (miRNAs) as potential regulators of Smad4 from an expression library of 388 human miRNAs. The screening was supported by bioinformatic analysis, as 24 of 39 identified miRNAs were also predicted to target Smad4. MiR-199a, one of the identified miRNAs, was inversely correlated with Smad4 expression in various human cancer cell lines and gastric cancer tissues, and repressed Smad4 expression and blocked canonical TGF-β transcriptional responses in cell lines. These effects were dependent on the presence of a conserved, but not perfect seed paired, miR-199a-binding site in the Smad4 3′-untranslated region (UTR). Overexpression of miR-199a significantly inhibited the ability of TGF-β to induce gastric cancer cell growth arrest and apoptosis in vitro, and promoted anchorage-independent growth in soft agar, suggesting that miR-199a plays an oncogenic role in human gastric tumourigenesis. In conclusion, our functional screening uncovers multiple miRNAs that regulate the cellular responsiveness to TGF-β signalling and reveals important roles of miR-199a in gastric cancer by directly targeting Smad4.

Previous microRNA (miRNA) array results have shown that the expression of miR-27b is upregulated in heart tissues from human cardiomyopathy and pressure-overloaded hypertrophic mouse model, implying that miR-27b might play an important role in heart diseases. To study the in vivo function of miR-27b, we generated a transgenic mouse line overexpressing miR-27b under the control of the 5.5 kb promoter of a-myosin heavy chain (a-MHC). Real-time PCR results demonstrated that miR-27b precursor and mature miR-27b were significantly increased in the heart tissues of miR-27b transgenic mice. miR-27b transgenic mice not only displayed cardiac hypertrophy, but also exhibited significant cardiac fibrosis. Further study showed that matrix metalloproteinase 13 (MMP13), a key regulator involved in cardiac fibrosis, was the target of miR-27b. The expression of MMP13 was decreased and the expression of Col I and III was increased in miR-27b transgenic mice.. In addition, defects in ultrastructral architecture were also found in miR-27b trans-genic mice. The above results demonstrated that miR-27b might promote cardiac fibrosis through inhibiting MMP13.

Job scheduling technology is one of the Hadoop platform’s key technologies, whose main function is to control the execute sequence of job and the distribution of computing resources, which directly relates to the Hadoop platform’s overall performance and system resources, usage. However, the existing job scheduling algorithms such as FIFO Scheduler, Fair Scheduler and Capacity Scheduler all have some defects. To overcome theses defects, this paper proposed a new algorithm Hadoop Greedy Scheduler Based on the Fair (HGSF). Firstly, the job pools are sorted by priority from high to low; pools in the same priority are sorted by their minimum requirements. Then their minimum requirements are met in turn. If have spare computing resources, it will be assigned to the job pool which has the highest priority and the minimum difference between the ideal requirement and the minimum requirement. Finally, the algorithm uses delay allocation strategy to improve the localization of the data for computing tasks. The experimental results testified the effectiveness of the proposed algorithm.

Recent studies have begun to reveal critical roles of microRNAs (miRNAs) in the pathogenesis of cardiac hypertrophy and dysfunction. In this study, we tested whether a transforming growth factor-β (TGF-β)-regulated miRNA played a pivotal role in the development of cardiac hypertrophy and heart failure (HF). We observed that miR-27b was upregulated in hearts of cardiomyocyte-specific Smad4 knockout mice, which developed cardiac hypertrophy. In vitro experiments showed that the miR-27b expression could be inhibited by TGF-β1 and that its overexpression promoted hypertrophic cell growth, while the miR-27b suppression led to inhibition of the hypertrophic cell growth caused by phenylephrine (PE) treatment. Furthermore, the analysis of transgenic mice with cardiomyocyte-specific overexpression of miR-27b revealed that miR-27b overexpression was sufficient to induce cardiac hypertrophy and dysfunction. We validated the peroxisome proliferator-activated receptor-γ (PPAR-γ) as a direct target of miR-27b in cardiomyocyte. Consistently, the miR-27b transgenic mice displayed significantly lower levels of PPAR-γ than the control mice. Furthermore, in vivo silencing of miR-27b using a specific antagomir in a pressure-overload-induced mouse model of HF increased cardiac PPAR-γ expression, attenuated cardiac hypertrophy and dysfunction. The results of our study demonstrate that TGF-β1-regulated miR-27b is involved in the regulation of cardiac hypertrophy, and validate miR-27b as an efficient therapeutic target for cardiac diseases.

MicroRNAs involved in keratinocyte migration and wound healing are largely unknown. Here, we revealed the indispensable role of miR-21 in keratinocyte migration and in re-epithelialization during wound healing in mice. In HaCaT cell, miR-21 could be upregulated by TGF-β1. Similar to the effect of TGF-β1, miR-21 overexpression promoted keratinocyte migration. Conversely, miR-21 knockdown attenuated TGF-β1-induced keratinocyte migration, suggesting that miR-21 was essential for TGF-β-driven keratinocyte migration. Furthermore, we found that miR-21 was upregulated during wound healing, coincident with the temporal expression pattern of TGF-β1. Consistently, knockdown of endogenous miR-21 using a specific antagomir dramatically delayed re-epithelialization possibly due to the reduced keratinocyte migration. TIMP3 and TIAM1, direct targets of miR-21, were verified to be regulated by miR-21 in vitro and in vivo, indicating that these two molecules might contribute to miR-21-induced keratinocyte migration. Taken together, our results demonstrate that miR-21 promotes keratinocyte migration and boosts re-epithelialization during skin wound healing.

Accumulating evidence has shown that miRNAs are aberrantly expressed in human gastric cancer and crucial to tumorigenesis. Herein, we identified the role of miR-148a in gastric cell proliferation. miR-148a knockdown inhibited cell proliferation in gastric cancer cell lines. Conversely, miR-148a overexpression promoted cell proliferation and cell cycle progression. p27, a key inhibitor of cell cycle, was verified as the target of miR-148a, indicating miR-148a might downregulate p27 expression to promote gastric cell proliferation. Moreover, we confirmed that miR-148a expression was frequently and dramatically downregulated in human advanced gastric cancer tissues, and observed a good inverse correlation between miR-148a and p27 expression in tumor samples. Thus, our results demonstrated that miR-148a downregulation might exert some sort of antagonistic function in cell proliferation, rather than promote cell proliferation in gastric cancer.

Geft is a guanine nucleotide exchange factor, which can specificallyactivate Rho family of small GTPase by catalyzing theexchange of bound GDP for GTP. Geft is highly expressed inthe excitable tissue as heart and skeletal muscle and plays importantroles in many cellular processes, such as cell proliferation,migration, and cell fate decision. However, the invivo role of Geft remains unknown. Here, we generated a Geftconditional knockout mouse by flanking exons 5-17 of Geftwith loxP sites. Cre-mediated deletion of the Geft gene in heartusing Mef2c-Cre transgenic mice resulted in a dramatic decreaseof Geft expression. Geft knockout mice develop normallyand exhibit no discernable phenotype, suggesting Geft isdispensable for the development of the second heart field inmouse. The Geft conditional knockout mouse will be a valuablegenetic tool for uncovering the in vivo roles of Geft duringdevelopment and in adult homeostasis. (BMB reports2012; 45(3): 153-158)

To prepare the polyclonal antibody against human Fkbp19 for future functional studies of Fkbp19.Prokaryotic expression vector pET21a-Fkbp19 was transformed into E.coli BL21-DE3, and then induced by IPTG. The recombinant protein was purified by Ni-NTA resin and used to immunize rabbits. Antiserums were used for Western blot and immunofluorescence to detect Fkbp19 in breast tumor cell.His-Fkbp19 fusion protein was successfully expressed in E.coli. High titer polyclonal antiserum was obtained by immunizing rabbits with purified His-Fkbp19 fusion protein. The antiserum could detect endogenous Fkbp19 protein in breast tumor cell very well by Western blot.The polyclonal antiserum against Fkbp19 was successfully generated.