Restoration of CpG Methylation in the Egf promoter region during rat liver regeneration

Epidermal growth factor [EGF] is an important factor for healing after tissue damage in diverse experimental models. It plays an important role in liver regeneration [LR]. The objective of this experiment is to investigate the methylation variation of 10 CpG sites in the Egf promoter region and their relevance to Egf expression during rat liver regeneration. As a follow up of our previous study, rat liver tissue was collected after rat 2/3 partial hepatectomy [PH] during the re-organization phase [from days 14 to days 28]. Liver DNA was extracted and modified by sodium bisulfate. The methylation status of 10 CpG sites in Egf promoter region was determined using bisulfite sequencing polymerase chain reaction [PCR], as BSP method. The results showed that 3 [sites 3, 4 and 9] out of 10 CpG sites have strikingly methylation changes during the re-organization phase compared to the regeneration phase [from 2 hours to 168 hours, P=0.002, 0.048 and 0.018, respectively]. Our results showed that methylation modification of CpGs in the Egf promoter region could be restored to the status before PH operation and changes of methylation didn't affect Egf mRNA expression during the re-organization phase

Application of hydrodynamics-based transgene to gene transfection in rat fatty liver / 解剖学报

Objective To study the condition and method of hydrodynamics-based transgene(HDT) in rat fatty liver. Methods Inject different dosages and concentrations of green fluorescent protein plasmid pEGFP-C1 at different speeds, then collect 4 rats' liver leaves at different time points after injection and prepare their frozen section, finally observe and quantify the GFP expression with fluo rescence microscope at 488 nm excitation wavelength. Results Plasmid pEGFP-C1 concentration 33mg/L, injection speed 2ml/s, injection volume 8.5%of rat body weight, injected plasmid. After 6 hours of injection, GFP-positive cells rate of pedicel leaf is about 18%, left leaf about 14%, middle leaf about 12.5%;R3ight leaf about 10% and tail leaf about 8%. GFP begin to gradually reduce since 24 hours, until 72 hours almost no GFP-positive cells were checked in all liver leaves. Conclusion Hydrodynamics-based transgene can be applied to rat fatty liver, the appropriate conditions of this method are 33mg/L plasmid concentration, 8.5% rat avoirdupois, 2ml/s injection speed, and the suitable time to observe the proportion of GFP-positive cells is 6-24 hours after gene injection.