大鼠下丘脑薄片视上核神经元的细胞内生物电记录

从成年Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠用振动切片机制备含有视上核的下丘脑冠状薄片（５００μｍ厚）,并对视上核神经元（ｎ＝１７）进行常规细胞内生物电记录。测得静息电位－６０±８ｍＶ,膜输入电阻１７３±５８ＭΩ,时间常数１０．２±３．９ｍｓ,动作电位幅度６５±１２ｍＶ,阈电位－４４±７ｍＶ,由Ｉ─Ｖ曲线测得斜率电阻１５８±６２ＭΩ,大部分细胞还显示内向整流特性。在静息电位状态下,５７％细胞保持静息,４３％有自发锋电位发放。细胞的锋电位发放模式７８％为时相型,２２％为持续型。外源性去甲肾上腺素（ｎ＝７）或谷氨酸钠（ｎ＝５）可引起伴有膜电阻减小的去极化反应,并可导致锋电位的串发放。     

Conserved expression of the PRELI domain containing 2 gene (<Emphasis Type="Italic">Prelid2</Emphasis>) during mid-later-gestation mouse embryogenesis

Prelid2, which belongs to the PRELI domain containing family, is identified as a conserved evolution gene. The expression and regulation during embryonic development of the prelid2 gene is unknown. In this study, we investigated the prelid2 gene expression and regulation using mouse embryos model, by in situ hybridization analysis, RT-PCR and bisulfite sequencing. In situ hybridization analysis showed that prelid2 gene expression were found in midbrain, spinal cord, optic eminence, otic vesicle and tail at E9.5 and E10.5 embryos, in forebrain, hindbrain, heart, lung, liver and kidney at E13.5 and E15.5 embryos. Real-time quantitative RT-PCR results verified the expression pattern in the four major mouse organs, brain, heart, lung, and liver during organs differentiation and formation. Bisulfite sequencing illustrated the consistent result of expression and its unmethylation status in the genomic promoter region at E12.5, E18.5, and new born. Thus, the prelid2 gene is a widely-spread, persistently expressed and unmethylated gene in mouse embryonic development. Our results suggest that the PRELI domain containing 2 gene is involved in mouse embryonic development.     

Strongylocentrotus nudos Egg Polysaccharide induces autophagy and apoptosis in leukaemia cells by regulating mitochondrial function

In this study, we investigated the ability of the Polysaccharide from the Eggs of Strongylocentrotus nudus (SEP) to regulate cellular autophagy and apoptosis in leukaemia cells. Human acute myeloid leukaemia (AML) cells (HL60) and murine AML cells (L1210) treated with SEP were used to assess viability using Cell Counting Kit-8, cytotoxicity by measuring lactate dehydrogenase release, the generation of reactive oxygen species (ROS) by DCFH-DA staining. In addition, we utilized a mouse model of leukaemia in which L1210 cells were injected into DBA/2 mice by sub-axillary injection. Treatment with SEP decreased cell viability, increased in cytotoxicity and increased the release of ROS in a dose-dependent manner. SEP treatment was also associated with the activation of pro-apoptotic proteins cleaved caspase-3, cleaved caspase-9 and cleaved poly (ADP-ribose) polymerase (PARP). Activation of the apoptotic pathway led to the release of cytochrome C (CytoC) into the cytosol of the cell resulting in decreased membrane potential. The effect of SEP treatment was depended on the activation of the nuclear factor kappa-B (NF-κB) signalling pathway as SEP treatment led to an increase in NF-κB phosphorylation, and inhibition of NF-κB signalling using PDTC blocked SEP-mediated activation of apoptosis. Treatment with SEP also prolonged survival time in our leukaemia mouse model and was associated with diminished tumour volume, increased leucocyte and lymphocyte proliferation, promoted pro-inflammatory factor release in serum and enhanced immune function. Taken together, these data suggest that SEP inhibits the progression of leukaemia by initiating mitochondrial dysfunction, autophagy, and apoptosis via the NF-κB signalling pathway.