Development and optimization of a cell screening system for farnesoid X receptor agonist / 生物工程学报

This study aims to develop an improved cell screening system for farnesoid X receptor (FXR) agonists based on a dual luciferase reporter gene system. FXR response element (FXRE) fragments from FXR target genes were cloned and inserted into upstream of firefly luciferase (Luc) gene in the plasmid pGL4-luc2P-Hygro. In combination with the internal reference plasmid containing renilla luciferase, a dual luciferase reporter gene system was developed and used for high throughput screening of FXR agonists. After studying the effects of over-expression of RXR, mouse or human FXR, various FXRE fragments, and different ratio of FXR plasmid amount to reporter gene plasmid, induction efficiency of the screening system was optimized by the known FXR agonist GW4064, and Z factor for the system reached 0.83 under optimized conditions. In summary, an improved cell screening system based on double luciferase reporter gene detection system was developed to facilitate the discovery of FXR agonists, where a new enhanced FXRE element was formed by a superposition of multiple FXRE fragments from FXR target genes, instead of a superposition of traditional IR-1 (inverted repeats-1) fragments.

Mechanism of miR-381 on macrophage infiltration in polymyositis by targeting stromal cell derived actor-1 / 解剖学报

Objective To explore the mechanism of miR-381 on the infiltration of polymyositis (PM) macrophages by targeting stromal cell derived factor-1 (SDF-1). Methods PM model mouse was constructed by rabbit myosin (1.5 mg), mycobacterium tuberculosis (5 mg) and pertussis toxin (500 ng). The 30 PM model mice were divided into control group and PM+miR-381 group (n = 15/group). During the same period, 15 healthy mice were used as a control group. Mice in the PM+miR-381 group were injected with miR-381 agomir (300 μg) intraperitoneally for 2 weeks. Serum creatine kinase (s-CK), interleukin (IL)-1β and IL-6 levels in serum of each group of mice, and the pathological changes of muscle tissue were detected and compared. The macrophage marker protein F4/80 was detected by immunohistochemical staining to assess the infiltration of macrophages. The expression levels of miR-381 and SDF-1 mRNA and protein in muscle tissues of each group were detected. The target relationship between miR-381 and SDF-1 was verified by dual luciferase report. Mouse macrophages were divided into miR-381 NC group and miR-381 mimic group. The SDF-1 mRNA and protein levels in each group were detected by Real-time PCR and Western blotting. Transwell was used to detect the level of cell migration to evaluate the infiltration capacity. Results The above indicators of the three groups were significantly different (P<0.05). The level of miR-381 in the muscle tissue of the PM group was significantly lower than that of the control group, s-CK, IL-1β, IL-6, histological score, macrophage infiltration, and SDF-1 mRNA and protein expression levels were significantly higher than those of the control group (P<0.05). The level of miR-381 in the muscle tissue of the PM+ miR-381 group was significantly higher than that of the PM group, s-CK, IL-1β, IL-6, histological score, macrophage infiltration, and SDF-1 mRNA and protein expression levels were significantly lower than those in the PM group (P<0.05). The dual luciferase report result indicated that miR-381 could target binding to SDF-1. The expression levels of SDF-1 mRNA and protein in macrophages in the miR-381 mimic group were significantly lower than those in the miR-381 NC group (P<0.05). The number of migrating cells in the miR-381 mimic group was significantly lower than that in the miR-381 NC group (P<0.05). Conclusion Increasing the level of miR-381 can inhibit the inflammatory infiltration ability of macrophages by targeting the expression of SDF-1, thereby alleviating PM.

MicroRNA￣513c￣5p expression in cervical cancer and targeting histone deacetylase 1 regulating cervical cancer cell migration and invasion / 解剖学报

Objective To investigate the expression of microRNA (miR)-513c-5p in cervical cancer and the mechanism of targeting histone deacetylase 1 (HDAC1) regulating cervical cancer cell migration and invasion. Methods Clinically collected 86 patients with cervical cancer. The levels of miR-513c-5p in tumor tissues and adjacent tissues were detected by Real-time PCR. The relationship between miR-513c-5p and pathological characteristics of cervical cancer was analyzed. It was verified that miR-513c-5p targets HDAC1 by a dual luciferase report. Cervical cancer HeLa cells were divided into four groups: control group, mimic group, mimic+HDAC1 group and HDAC1 group. MiR-513c-5p and(or) HDAC1 were overexpressed by plasmid transfection technology. Real-time PCR and Western blotting were used to detect the expression level of RNA or protein, respectively. The cell growth, migration, and invasion capabilities of each group were measured by CCK-8 method, cell scratch test, and Transwell test. Results The level of miR-513c-5p in cervical cancer tissues was significantly lower than that in adjacent tissues. Low levels of miR-513c-5p were associated with higher local invasion, lymphatic metastasis, and distal metastasis (P<0. 05). MiR-513-5p targeted HDAC1 expression. Overexpression of miR-513c-5p inhibited significantly the growth, migration and invasion of cervical cancer cells (P < 0. 05). Overexpression of HDAC1 promoted growth, migration and invasion (P<0. 05), and reversed the inhibitory effect of miR-513c-5p (P<0. 05). Conclusion Low levels of miR-513c-5p might be related to cervical cancer metastasis, and miR-513c-5p could inhibit the growth, migration and invasion of cervical cancer HeLa cells by targeted inhibition of HDAC1 protein expression.

Establishment of drug screening model targeting PRDM1 gene promoter / 重庆医学

Objective To construct a double luciferase reporter gene vector with PRDM1 gene promoter as target,and establish drug screening cell model in vitro,hope to find small molecule compounds in Chinese herbal medicine library by this model.Methods Total DNA was extracted from 293T cells and it was used for amplifying the fragment contained PRDM1 gene promoter (267 bp/1 257 bp) by PCR.The amplified product was inserted into pGL3-Basic vector.The PCR product and pGL3-PRDM1 vector were verified by sequencing and alignment.The pGL3-PRDM1 and pRL-TK vector were co-transfected into engineer cells.The activity of PRDM1 gene promoter could be assayed by measuring luciferase.The method was optimized by changing ratio of two vectors.Results The highest transfection efficiency and luciferase activity were found in ratio of n(pGL-PRDM1) ∶ n(pRL-TK)=2 ∶1,and with the recombinant luciferase report gene vector contained the length of 1 257 bp amplified fragment transfecting into U266 cells.Moreover,the inductor (5-Aza-CdR) of PRDM1 gene was used for authenticating the method(P＜0.01),the fluoresscence in tensity and promoter activity of PRDM1 gene were enhanced in a dose dependent manner with 5-Aza-CdR.The activity of the promoter of PRDM1 gene was significantly decreased from the concentration of 5 μmol/L of Artemisinid(P＜0.05).The total glucosides of paeoniflorin promoted the promoter activity of PRDM1 gene at a low concentration,and inhibited the promoter activity of PRDM1 gene at a high concentration.Artesunate has no effect on cell proliferation.The effect of total glucosides of paeony on cell proliferation was more complicated.Conclusion A drug selection model targeting PRDM1 gene promoter has been successfully established,and artesunate has been screened to inhibit the promoter activity of PRDM1 gene.