目的 探讨肝癌裸鼠移植瘤细胞DNA合成与端粒酶表达的近日节律。方法 在时辰同步化裸鼠中构建肝癌细胞SMMC27721裸鼠移植瘤,继续在程控光照条件下饲养,于光照后3 、9 、15 、21h取样，用流式细胞仪测定各时期细胞DNA含量，细胞周期分布及端粒酶活性水平。结果 肝癌裸鼠移植瘤细胞DNA 合成随近日节律变化,且伴随端粒酶活性的同步节律变化,呈近日节律特征。结论 肝癌裸鼠移植瘤的生长与端粒酶活性表达在静止相达高峰，为制定肿瘤时辰化疗方案提供了有价值的参考。

Background The success of any gene-therapy approach depends on the survival of the genetically engineered cells that are implanted in the patient to deliver the therapeutic product. Immunoisolation of nonautologous cells within a microcapsule is a unique approach for gene therapy. Methods We employed an immunoisolation device that protects nonautologous cells from destruction, to implant human atrial natriuretic peptide (hANP)-producing Chinese hamster ovary (CHO) cells in two-kidney, one-clip (2K1C) hypertensive rats. CHO cells transfected with the plasmid CMV-cANP were encapsulated in biocompatible polycaprolactone (PCL) capsules, and then the PCL capsules were implanted into 2K1C hypertensive rats intraperitoneally. Results The implantation of encapsulated hANP-producing cells caused a significant delay of blood pressure (BP) increase 2 weeks post-implantation and the effect lasted for more than 5 months. The implantation of encapsulated hANP-producing cells also caused significant increases in renal blood flow (RBF), glomerular filtration rate (GFR), sodium output, urine excretion, and urinary cGMP levels. These beneficial effects were reflected morphologically by an attenuation of the glomerular sclerotic lesions, reduct on in cardiomyocyte size, tubular injury and renal arterial thickening. Immunoreactive hANP can be detected in the blood of 2K1C rats after implantation of the PCL capsules containing hANP-producing cells. Conclusions This study demonstrates the usefulness of encapsulated ANP gene transfected cells as a new tool for ANP gene delivery in studying renovascular hypertension and cardiovascular diseases. Thus, our results may have important implications for clinical use of transgene cells as therapeutic agents in the treatment of cardiovascular diseases.

Renal excretion in experimental hypertensive rats implanted with encapsulated human atrial natriuretic peptide (hANP)-producing cells is circadian periodic. Chinese hamster ovary (CHO) cells transfected with the plasmid hANP-cDNA were encapsulated in biocompatible polycaprolactone capsules for intraperitoneal implantation into two-kidney, one-clip (2K1C) hypertensive rats. During a 12:12 light-dark cycle, as compared to control CHO cells, the implantation of encapsulated hANPproducing CHO cells was associated with an increase in the net excretion of water, sodium and potassium, and with a reversal of the advanced circadian phases related to renovascular hypertension in 2K1C rats. The increase in blood pressure postimplantation was delayed, and increases in renal blood flow, glomerular filtration rate, sodium output, urinary excretion and urinary cyclic GMP concentrations were also found. Implantation of encapsulated hANP-producing cells affects circadian rhythms in kidney excretion functions of 2K1C rats, and may be useful for the treatment of cardiovascular disease.

cultured neuroglial cells, we found that human Clock protein DNA-binding peptide [residue 35-47, hClock-(35-47)] had a translocation activity very similar to Tat-(48-60). The cellular uptake of hClock-(35-47) increases with the increase of incubation time and concentration. The internalization effect at 4℃ was same as that at 37℃. Internalization of hClock-(35-47) was saturable and could be inhibited by the excess of the other MPPs. Moreover, The uptake of these peptides were ignificantly inhibited in the presence of heparan sulfate. These results strongly suggested that the hClock-(35-47) shared a common or very similar internalization pathway with other MPPs. Furthermore, we injected rat through the common carotid artery with hClock-(35-47)-FITC peptide, and cryostat sections of the brain were prepared and observed using a fluorescence microscope. Result showed that the peptide had the ability to translocate through the blood-brain barrier. It is promising to provide a new safe carrier for the intracellular and encephalic treatment.