The Up-Regulation of miR-199b-5p in Erythroid Differentiation Is Associated with GATA-1 and NF-E2

Yuxia Li,Hua Bai,Zhongzu Zhang,Weihua li,Lei Dong,Xueju Wei,Yanni Ma,Junwu Zhang,Jia Yu,Guotao Sun,Fang Wang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.3

MicroRNAs (miRNAs) represent a class of small non-co-ding regulatory RNAs that play important roles in normal hematopoiesis, including erythropoiesis. Although studies have identified several miRNAs that regulate erythroid commitment and differentiation, we do not understand the mechanism by which the crucial erythroid transcription factors, GATA-1and NF-E2 directly regulate and control differentiation via miRNA pathways. In this study, we identified miR-199b-5p as a key regulator of human erythropoiesis, and its expression was up-regulated during the erythroid differentiation of K562 cells. Furthermore, the increase of miR-199b-5p in erythroid cells occurred in a GATA-1- and NF-E2-dependent manner during erythrocyte maturation. Both GATA-1 and NF-E2 bound upstream of the miR-199b gene locus and activated its transcription. Forced expression of miRNA-199b-5p in K562 cells affected erythroid cell proliferation and maturation. Moreover, we identified c-Kit as a direct target of miR-199b-5p in erythroid cells. Taken together, our results establish a functional link among the erythroid transcription factors GATA-1/NF-E2, miR-199b-5p and c-Kit, and provide new insights into the coupling of transcription and post-transcription regulation in erythroid differentiation.

The Up-Regulation of miR-199b-5p in Erythroid Differentiation Is Associated with GATA-1 and NF-E2

Li, Yuxia,Bai, Hua,Zhang, Zhongzu,li, Weihua,Dong, Lei,Wei, Xueju,Ma, Yanni,Zhang, Junwu,Yu, Jia,Sun, Guotao,Wang, Fang Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.3

MicroRNAs (miRNAs) represent a class of small non-coding regulatory RNAs that play important roles in normal hematopoiesis, including erythropoiesis. Although studies have identified several miRNAs that regulate erythroid commitment and differentiation, we do not understand the mechanism by which the crucial erythroid transcription factors, GATA-1and NF-E2 directly regulate and control differentiation via miRNA pathways. In this study, we identified miR-199b-5p as a key regulator of human erythropoiesis, and its expression was up-regulated during the erythroid differentiation of K562 cells. Furthermore, the increase of miR-199b-5p in erythroid cells occurred in a GATA-1- and NF-E2-dependent manner during erythrocyte maturation. Both GATA-1 and NF-E2 bound upstream of the miR-199b gene locus and activated its transcription. Forced expression of miRNA-199b-5p in K562 cells affected erythroid cell proliferation and maturation. Moreover, we identified c-Kit as a direct target of miR-199b-5p in erythroid cells. Taken together, our results establish a functional link among the erythroid transcription factors GATA-1/NF-E2, miR-199b-5p and c-Kit, and provide new insights into the coupling of transcription and post-transcription regulation in erythroid differentiation.

Effect of Basalt Fiber on the Strength Properties of Polymer Reinforced Sand

Jin Liu,Yuxia Bai,Zezhuo Song,Ying Wang,Zhihao Chen,Qiongya Wang,Debi Prasanna Kanungo,Wei Qian 한국섬유공학회 2018 Fibers and polymers Vol.19 No.11

This paper displays an experimental study of the effect of basalt fiber on the strength properties of polymer reinforced sand. Laboratory trials of unconfined compression test (UCS), direct shear test, and tensile test were conducted on the specimens treated with polymer and basalt fiber, and several factors including polymer content, fiber content and dry density of sand that will influence the strength behaviors are investigated in detail. Based on test results and scanning electron microscope (SEM) images, the reinforcement mechanism was analyzed. The results showed that the polymer content, basalt fiber content and dry density of sand had greatly improved the strength behaviors of reinforced specimens. The increase in polymer and fiber content had an active effect on strength characteristics, while the angle of internal decreased slightly. The strength properties were enhanced with the increase in dry density, and the effect of dry density on tensile strength is affected by fiber content. The presence of randomly distributed fibers has formed a spatial fiber-sand net in sand, and the additive of polymer solution formed membrane to enwrap sand particles and connect sand and fibers, thereby formed a stable structure in sand. These structures have increased the bonding and interlocking forces between sand and fibers, and decreased the void ratio of reinforced specimens.

Influence of Polyurethane Polymer on the Strength and Mechanical Behavior of Sand-root Composite

Jin Liu,Zhihao Chen,Zhaojun Zeng,Debi Prasanna Kanungo,Fan Bu,Yuxia Bai,Changqing Qi,Wei Qian 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

Vegetation has good application in slope stabilization, but its beneficial effects on reinforcing topsoil are generallylimited by the soil properties it was cultivated in. This study aims at evaluating the strength improvements of sand-rootcomposite by treating with polyurethane polymer and hence investigating the mechanism of polymer-root-soil interactions. Vegetation roots were selected and mixed with dry sand and polymer solution to prepare remolded specimens. A series ofexperimental tests were then performed at different percentages of root content (0, 0.4, 0.8, 1.2, and 1.6 % by weight of drysand) and polymer content (1, 2, and 4 % by weight of dry sand) to evaluate the shear parameters and unconfinedcompressive strength (UCS). The combined mechanism was studied by scanning electron microscopy (SEM) images. Theresults showed that the strengthening effect has greater efficiency with higher polymer content. Through varying contents ofvegetation root, it was found that low root content induced an undesirable weakening effect on the strength of the treated soil. However, this situation was somewhat improved with the increase in root content. The good flexibility of polymers not onlypromote the capacity of soil to energy absorption, but also impart good ductility to soil. The presence of polymers greatlystrengthens soil stability due to its special network structure, by which the improved shear resistance at the root-soil interfaceprovides sufficient anchorage effect for the tensile strength of roots to be fully mobilized. Overall, the synergistic effect ofroot reinforcement and polymer treatment has the potential for its use in soil stabilization.

Study on the Brittleness Characteristics of Sand Reinforced with Polypropylene Fiber and Polyurethane Organic Polymer

Jin Liu,Ying Wang,Debi Prasanna Kanungo,Jihong Wei,Yuxia Bai,Ding Li,Zezhuo Song,Yi Lu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.3

The brittleness characteristics of sand reinforced with polypropylene fiber (PF) and polyurethane organic polymer(POP) was investigated in detail using direct tensile and unconfined compression tests. The effects of POP/PF content, curing time and sand density on the brittleness of reinforced sand were studied. The reinforcement mechanism was analyzed with images of scanning electron microscope (SEM) and sample failure mode. The test results indicated that the brittleness of sand increases with curing time, and it has no obvious change after 48 h. The brittleness was decreased obviously with the increase in POP and PF contents. The brittleness of reinforced sand reaches a relative stable state when the POP and fiber contents reach 3 % and 0.6 % respectively. The brittleness also increased with sand density and it reaches a plateau at 1.55 g/cm3. The POP forms a large number of polymer films with water volatilizing in the sand, and the sand particles were wrapped. Fibers improved the compressive strength of reinforced sand and changed it to a more ductile one. Polypropylene fiber plays the role of reinforcing the sand, effectively improving the strength of the sand and reducing the brittleness of the reinforced sand.