Functional analysis of the long-range regulatory element of BMP2 gene.

Recently, several pedigree-based studies have shown that abnormal replication of an enhancer element regulatory region in the downstream of the bone morphogenetic protein 2 (BMP2) gene is the cause of brachydactyly type A2 (BDA2). However, the exact molecular function of this regulatory region is unclear, and even conflicting results have emerged. In this study, based on bioinformatics analysis, we amplified target fragments of different lengths in this regulatory region by PCR technology, including a highly conserved 2.1 kb core sequence and 3 fragments that can completely cover the core 2.1 kb fragment. Then, the gene recombination vectors were constructed, and the biological function of these fragments was analyzed by the dual-luciferase reporter gene technology system. We found that the highly conserved 2.1 kb fragment did not have enhancer activity, while all of three truncated fragments showed strong enhancer activity. The results suggest that the expression regulation mode of the BMP2 gene is very complex. For the downstream regulatory region, selecting fragments of different lengths may have different effects on the regulation of BMP2 expression, which may due to the fragments with different lengths carrying different regulatory elements in the number of types. In summary, this study revealed the complexity of BMP2 gene regulatory elements, and provided new clues and directions for the subsequent in-depth exploration of the molecular pathogenic mechanism of BDA2.

DPD Study on the Interfacial Properties of PEO/PEO-PPO-PEO/PPO Ternary Blends: Effects of Pluronic Structure and Concentration.

Using the method of dissipative particle dynamics (DPD) simulations, we investigated the interfacial properties of PEO/PEO-PPO-PEO/PPO ternary blends composed of the Pluronics L64(EO13PO30EO13), F68(EO76PO29EO76), F88(EO104PO39EO104), or F127(EO106PO70EO106) triblock copolymers. Our simulations show that: (i) The interfacial tensions (γ) of the ternary blends obey the relationship γF68 < γL64 < γF88 < γF127, which indicates that triblock copolymer F68 is most effective in reducing the interfacial tension, compared to L64, F88, and F127; (ii) For the blends of PEO/L64/PPO and the F64 copolymer concentration ranging from ccp = 0.2 to 0.4, the interface exhibits a saturation state, which results in the aggregation and micelle formation of F64 copolymers added to the blends, and a lowered efficiency of the L64 copolymers as a compatibilizer, thus, the interfacial tension decreases slightly; (iii) For the blends of PEO/F68/PPO, elevating the Pluronic copolymer concentration can promote Pluronic copolymer enrichment at the interfaces without forming the micelles, which reduces the interfacial tension significantly. The interfacial properties of the blends contained the PEO-PPO-PEO triblock copolymer compatibilizers are, thus, controlled by the triblock copolymer structure and the concentration. This work provides important insights into the use of the PEO-PPO-PEO triblock copolymer as compatibilizers in the PEO and PPO homopolymer blend systems.