ABSTRACT
Alzheimer′s disease ( AD) , is a neurodegenerative disorder of the brain that is characterized by loss of memory and cognitive decline.At present, AD etiology remains unclear and there are no effective prevention and treatment measures in clinical practice.Peroxisome proliferator-activated receptorγ( PPARγ) is a ligand-regulated nuclear hormone receptor.Recent studies showed PPARγ-pathway played an important role in the pathogenesis of AD and some PPARγagonists have been proven to be neuroprotective in vitro and in vivo models.This paper reviews the roles of PPARγand related mechanisms in AD, summarizes affecting factors about PPARγpathway.Particularly, the effect of cyanidin-3-O-glucoside ( Cy3G) , one of the anthocyanidin glycoside forms, is a compound of naturally occurring phenolic compounds, suggesting the neuroprotective effect of Cy3G might be used as a potential natural PPARγagonist in the nervous system.
ABSTRACT
Chemically synthetic siRNA and miRNA have become powerful tools to study gene function in the past decade. Fluorescent dyes covalently attached to the 5′ or 3′ ends of synthetic small RNAs are widely used for fluorescently imaging and detection of these RNAs. However, the reliability of fluorescent tags as small RNA markers in different conditions has not attracted enough attention. We used Cy3-labelled small RNAs to explore the reliability of fluorescent tags as small RNA markers in cell cultures involving serum. A strong Cy3-fluorescence signal was observed in the cytoplasm of the cells transfected with Cy3-miR24 in the culture medium containing fetal bovine serum (FBS), but qRT-PCR results showed that little miR24 were detected in these cells. Further study demonstrated that small RNAs were degraded in the presence of FBS, suggesting that it was Cy3-RNA fragments, rather than the original Cy3-miR24, diffused into cells. These phenomena disappeared when FBS was replaced by boiled-FBS, further supporting that the Cy3-fluorescence we observed in cells in the presence of FBS could not represent the presence of intact small RNAs. These findings addressed that fluorescent tags are not reliable for small RNA transfection in the presence of serum in culture.
ABSTRACT
AIM: To investigate the possibility of transfecting siRNA into rabbit cervical cells in transformation zone by the method of solid phase in vivo and to verify the effectivity of siRNA transfection by modifying the permeability of the cervical epithelium. METHODS: A sense strand small-interference RNA (siRNA) for human papillomavirus type 16 (21 bp) was designed and labeled with Cy3. siRNA-Lipo2000-carbomer gum was prepared. Twelve rabbits were included in the study and divided into experimental group and control group. In order to modify the permeability of cervical epithelium, hypertonic saline solution at concentration of 200 mmol/L was used to infuse the cervix in the experimental rabbits for 10 min, and normal saline was used for the control animals. The siRNA-Lipo2000-carbomer gum was applied to the surface of the rabbit cervix. Twenty-four hours later, the rabbits were sacrificed, and the cervix was isolated, cut into 2 parts, one part was for rapid frozen sectioning and the efficiency of transfection was observed under fluorescence microscope, another part was prepared by paraffin embedding and sectioning, and the form of cervical histiocytes was observed. Twelve SCID mice with SiHa cell cervical tumor, divided into experimental group and control group, were also used in the study. The mice in experimental group were treated with siRNA-Lipo2000-carbomer gum for 7 d. The control mice were treated with Lipo2000-carbomer gum only. Five days later, the mice were sacrificed and the tumor was collected, and the HPV16-DNA was measured by PCR. RESULTS: (1) Red fluorescence (Cy3) in cervical epithelium was observed in all rabbits. However, no different effect of siRNA transfection was found between the ways of modifying the cervical epithelium permeability. (2) No abnormal change such as flare, swelling and ulcer at all cervical tissue was observed, the cervical cell form was normal. (3) The titer of HPV16-DNA was decreased significantly after siRNA transfection (P<0.05). CONCLUSION: Transfection of siRNA into rabbit cervical epithelium in vivo is successful by using the method of solid phase and inhibits the processes of HPV-DNA, indicating that using RNAi is a practical way to treat HPV infection in human cercix and to decrease the incidence of cercical carcinoma.