Curcumin suppresses the expression of extracellular matrix genes in activated hepatic stellate cells by inhibiting gene expression of connective tissue growth factor

Upon liver injury, quiescent hepatic stellate cells (HSCs), the most relevant cell type for hepatic fibrogenesis, become active and overproduce extracellular matrix (ECM). Connective tissue growth factor (CTGF) promotes ECM production. Overexpression of CTGF during hepatic fibrogenesis is induced by transforming growth factor (TGF)-beta. We recently demonstrated that curcumin reduced cell growth and inhibited ECM gene expression in activated HSCs. Curcumin induced gene expression of peroxisome proliferator-activated receptor (PPAR)-gamma and stimulated its activity in activated HSCs, which was required for curcumin to suppress ECM gene expression, including alphaI(I)-collagen. The underlying mechanisms remain largely unknown. The aim of this study was to elucidate the mechanisms by which curcumin suppresses alphaI(I)-collagen gene expression in activated HSCs. We hypothesize that inhibition of alphaI(I)-collagen gene expression in HSCs by curcumin is mediated by suppressing CTGF gene expression through attenuating oxidative stress and interrupting TGF-beta signaling. The present report demonstrated that curcumin significantly reduced the abundance of CTGF in passaged HSCs and suppressed its gene expression. Exogenous CTGF dose dependently abrogated the inhibitory effect of curcumin. Activation of PPAR-gamma by curcumin resulted in the interruption of TGF-beta signaling by suppressing gene expression of TGF-beta receptors, leading to inhibition of CTGF gene expression. The phytochemical showed its potent antioxidant property by significantly increasing the level of total glutathione (GSH) and the ratio of GSH to GSSG in activated HSCs. De novo synthesis of cellular GSH was a prerequisite for curcumin to interrupt TGF-beta signaling and inhibited gene expression of CTGF and alphaI(I)-collagen in activated HSCs. Taken together, our results demonstrate that inhibition of alphaI(I)-collagen gene expression by curcumin in activated HSCs results from suppression of CTGF gene expression through increasing cellular GSH contents and interruption of TGF-beta signaling. These results provide novel insights into the mechanisms underlying inhibition of HSC activation by curcumin.     

淋巴细胞发育相关基因在鼻腔NK/T细胞淋巴瘤中表达的研究

探索鼻腔NK/T细胞淋巴瘤(N-NK/T-L)中淋巴细胞发育相关基因的表达及意义。方法:通过对EOMEs,ETS-1和MEF基因进行克隆、探针制备和组织芯片制备,对25例N-NK/T-L以及同部位11例B细胞淋巴瘤(BCL)、6例T细胞淋巴瘤(TCL)、3例正常脾组织和5例慢性炎性鼻黏膜组织进行了原位杂交检测。结果:EOMES、ETS-1、MEF基因在N-NL/T-L、BCL、TCL、脾和鼻粘膜中均有表达,但阳性率和表达强度不同。EOMES基因在N-NK/T-L的表达强度与BCL和TCL间有差异,MEF基因在N-NK/T-L的表达阳性率和强度与TCL间有差异,而ETS-1基因在N-NK/T-L与对照组间的表达无差异。T-bet、EOMES和MEF基因在N-NK/T-L的表达具有相关性。结论EOMES和MEF基因在N-NK/T-L中高表达,可能在该肿瘤发生和组织坏死中起重要作用,而ETS-1因在N-NK/T-L和对照组中普遍表达,提示其可能在淋巴造血系统的发育和功能中起基础性的共同通路。     

Stimulatory effect of polyethylene glycol (PEG) on gene expression in mouse liver following hydrodynamics-based transfection

BACKGROUND: Rapid intravenous injection of a large volume of plasmid DNA (pDNA), i.e. a transfection procedure based on hydrodynamics, is known to be an efficient and liver-specific method of in vivo gene delivery. However, the gene expression is transient. METHODS: We investigated the effect of addition of polyethylene glycol (PEG) to a solution of naked pDNA (luciferase) on the expression of the gene in mouse liver following transfection by the hydrodynamics-based technique. In addition, the mechanism leading to the enhancement of the gene expression was studied. RESULTS: The addition of 1% (w/v) PEG2000 to the pDNA solution enhanced the resulting gene expression in the liver. Increasing the PEG2000 concentration to more than 1 and up to 10% (w/v) rather diminished the gene expression level. By contrast, increasing the molecular weight of PEG to over 2000 up to 10 000 did not affect the level of gene expression. Histopathological and serum-chemistry examinations indicated that hydrostatic or osmotic pressure increased tissue and hepatocellular damage in a PEG-concentration-dependent manner, and resulted in a decrease in gene expression. Quantitative evaluation showed that the enhanced gene expression resulted from stabilization of the pDNA introduced into the hepatocytes and an enhancement of the transport of intact pDNA to the nucleus. CONCLUSIONS: For most gene therapy applications and gene function studies, sustained expression of the introduced gene(s) is necessary. This simple method to achieve enhanced gene expression in liver may have a great potential for a wide variety of laboratory studies in molecular and cellular biology as well as possibly for future clinical applications in humans.     

Upregulation of hepatic prolactin receptor gene expression by 17beta-estradiol following trauma-hemorrhage.

Although studies show protective effects of 17beta-estradiol (E2) or prolactin (PRL) treatment in male rats after trauma-hemorrhage (TH), the mechanism of the salutary effects of these agents remains unknown. Because E2 modulates PRL receptor (PRL-R) expression in the liver, we examined whether E2 treatment after T-H has any effects on hepatic PLR-R gene expression. Male Sprague-Dawley rats were subjected to trauma (i.e., 5-cm midline laparotomy) and hemorrhage (35-40 mmHg for 90 min) followed by fluid resuscitation (Ringer lactate) or sham operation and then treated with E2 (50 microg/kg body wt sc) or vehicle immediately before resuscitation. Liver samples were collected at 3 h thereafter, and PRL-R mRNA expression was determined by PCR. Liver expression of PRL-R short-form gene was unaffected by T-H, whereas that of the long-form gene was suppressed. Treatment of T-H rats with E2 significantly increased PRL-R short-form gene expression and normalized PRL-R long-form gene expression to sham levels. In the isolated hepatocytes, PRL-R short-form gene expression was predominant compared with the long-form gene. In contrast, only the short form was detected in Kupffer cells. In vitro treatment by E2 demonstrated an increase in the PRL-R long-form gene in hepatocytes, but E2 had no effect on PRL-R short-form gene expression in either the Kupffer cells or hepatocytes. Thus E2 treatment after T-H in males appears to directly upregulate PRL-R long-form gene expression in hepatocytes. However, the upregulation of the PRL-R short form might involve the interaction of multiple cell types in the liver.     

Wrestling with pleiotropy: genomic and topological analysis of the yeast gene expression network

The vast majority (>95%) of single-gene mutations in yeast affect not only the expression of the mutant gene, but also the expression of many other genes. These data suggest the presence of a previously uncharacterized "gene expression network"--a set of interactions between genes which dictate gene expression in the native cell environment. Here, we quantitatively analyze the gene expression network revealed by microarray expression data from 273 different yeast gene deletion mutants.(1) We find that gene expression interactions form a robust, error-tolerant "scale-free" network, similar to metabolic pathways(2) and artificial networks such as power grids and the internet.(3-5) Because the connectivity between genes in the gene expression network is unevenly distributed, a scale-free organization helps make organisms resistant to the deleterious effects of mutation, and is thus highly adaptive. The existence of a gene expression network poses practical considerations for the study of gene function, since most mutant phenotypes are the result of changes in the expression of many genes. Using principles of scale-free network topology, we propose that fragmenting the gene expression network via "genome-engineering" may be a viable and practical approach to isolating gene function.     

eQTL结合ASE分析显示帕金森病相关基因Lrrk2表达受顺式作用调控

富亮氨酸重复激酶2（Lrrk2）基因与家族性及散发性帕金森病(Parkinson′s disease, PD)密切相关,但其作用机制仍不十分清楚.本文以单核苷酸多态性(single nucleotide polymorphism, SNP)为切入点,对其调控机制进行研究. 以近交系C57BL/6J (B6)和DBA/2J (D2)小鼠杂交1代小鼠为实验动物,借助基因表达数量性状基因座(expression quantitative trait loci, eQTL)分析技术,结合等位基因特异性表达（allele specific expression difference, ASE）技术,验证帕金森病相关基因Lrrk2的顺式调控机制. eQTL分析显示,Lrrk2基因所在的位置有1个具有显著统计学意义（LRS值≥20）的顺式调节基因座.针对Lrrk2基因外显子区域错意突变SNP的ASE分析得出： rs50098646位点在cDNA水平上G∶A两碱基比值偏离1∶1,与gDNA水平中G∶A两碱基比值差异显著（P<0.01）,表达受顺式作用调节. 本研究结果表明,Lrrk2基因的表达受到顺式作用的调控.     

Mosaic patterns of transgene expression in plants

The review describes the phenomenon of mosaic transgene (gene) expression in plants. Parallels with the mosaic transgene (gene) expression in other organisms are presented. Parallels with the mosaic patterns of gene (transgene) expression in other organisms (Drosophila, transgenic animals, and others) are made.     

Effect of selective ET(A) receptor blockade on natriuretic peptide gene expression in DOCA-salt hypertension

To determine the role of endothelin-1 (ET-1) in the upregulation of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) observed in deoxycorticosterone acetate (DOCA)-salt hypertension, the selective ET-1 type-A receptor (ET(A)) antagonist ABT-627 was chronically administered to normal controls and hypertensive rats. Chronic ET(A) blockade in DOCA-salt-treated rats prevented the increase in blood pressure and circulating natriuretic protein (NP) levels and partially prevented left ventricular hypertrophy. The changes observed in NP gene expression in the atria were not affected by ABT-627. In the ventricles, ABT-627 reduced NP gene expression. Rats receiving the ET(A) antagonist alone showed reduced left ventricular NP gene expression. ABT-627 did not affect ventricular collagen III gene expression but enhanced left ventricular alpha-myosin heavy chain expression. These findings suggest that in vivo, ventricular but not atrial NP production is regulated by ET-1. This difference in response between atrial and ventricular NP gene expression to ET(A) receptor blockade is similar to that observed by us after applying angiotensin-converting enzyme inhibitors in other hypertensive models. In general therefore, atrial NP gene expression may not be as sensitive to the endocrine environment as is ventricular NP gene expression.     

Mosaic patterns of transgene expression in plants

The review describes the phenomenon of mosaic transgene (gene) expression in plants. Parallels with the mosaic transgene (gene) expression in other organisms are presented. Parallels with the mosaic patterns of gene (transgene) expression in other organisms (Drosophila, transgenic animals, and others) are made.     

Dual bio-responsive gene delivery via reducible poly(amido amine) and survivin-inducible plasmid DNA

A bioreducible poly(amido amine) (SS-PAA) gene carrier, known as poly (amido-butanol) (pABOL), was used to transfect a variety of cancer and non-cancer cell lines. To obtain cancer-specific transgene expression for therapeutic efficiency in cancer treatment, we constructed survivin-inducible plasmid DNA expressing the soluble VEGF receptor, sFlt-1, downstream of the survivin promoter (pSUR-sFlt-1). Cancer-specific expression of sFlt-1 was observed in the mouse renal carcinoma (RENCA) cell line. pABOL enhanced the efficiency of gene delivery compared to traditional carriers used in the past. Thus, a dual bio-responsive gene delivery system was developed by using bioreducible p(ABOL) for enhanced intracellular gene delivery and survivin-inducible gene expression system (pSUR-sFlt-1 or pSUR-Luc reporter gene) that demonstrates increased gene expression in cancer that has advantages over current gene delivery systems.     

Alteration of Gene Expression in Rice Hybrid F1 and Its Parental Seedlings

Hybrid rice ( Oryza sativa L. ) seedling is more vigorous in root development and plant growth than its parental lines in the tested indica rice of hybridized combination (Shanyou 63 (Fl): Zhenshan 97A × ♂Minghui 63). Analysis of the difference in gene expression between the hybrid Fl and its parental seedlings by means of mRNA differential display indicated that gene expression of the parental lines was obviously altered the hybrid Fl both in quantity and quality., Quantitatively, there were over-expression and under-expression of genes in hybrid Fl with genetic expression trend forwards a single parent. Qualititatively, hybrid Fl could have specific gene expression, single parem (maternal or paternal) gene silence, co-suppression of paternal genes, and single paternal gene expression. The relationship between heterosis formation and alteration of gene expression of parental lines in hybrid Fl was also discussed.