Contemporary Approaches for Identifying Rare Bone Disease Causing Genes

Recent improvements in the speed and accuracy of DNA sequencing, together with increasingly sophisticated mathematical approaches for annotating gene networks, have revolutionized the field of human genetics and made these once time consuming approaches assessable to most investigators. In the field of bone research, a particularly active area of gene discovery has occurred in patients with rare bone disorders such as osteogenesis imperfecta (OI) that are caused by mutations in single genes. In this perspective, we highlight some of these technological advances and describe how they have been used to identify the genetic determinants underlying two previously unexplained cases of OI. The widespread availability of advanced methods for DNA sequencing and bioinformatics analysis can be expected to greatly facilitate identification of novel gene networks that normally function to control bone formation and maintenance.     

大鼠PEDF基因RNA干扰慢病毒载体的构建与鉴定

目的 构建针对大鼠PEDF 基因的RNA干扰（RNAi）慢病毒表达载体并进行鉴定,探讨PEDF基因对缺血心肌血管新生的影响.方法 构建PEDF基因过表达质粒,测序鉴定.针对PEDF基因不同干扰靶点构建4种RNAi 病毒载体质粒pGCsi-U6/Neo/GFP/shRNA,测序鉴定.过表达质粒和RNAi质粒共转染293T细胞后应用Western blot方法进行外源筛靶确定PEDF基因RNAi 有效靶序列.有效RNAi 病毒质粒和其他3种辅助包装原件载体质粒通过Lipofectamine 2000共转染293T细胞,培养48 h后, 收集细胞培养上清液,将其浓缩后用孔稀释法测定病毒滴度.结果 过表达质粒及4种RNAi质粒构建成功.Western blot外源筛靶显示2个靶点能有效敲减目的基因的表达.PEDF shRNA慢病毒表达载体Serpinf1-RNAi-LV经293T细胞包装成功,收集293T细胞分泌的病毒上清测定浓缩病毒悬液的滴度为2×1012Tu/L.结论 成功构建了PEDF基因的RNAi慢病毒载体,为研究PEDF基因对缺血心肌血管新生的影响打下基础.     

Heterogeneity of hepatocellular carcinoma contributes to cancer progression

Hepatocellular carcinoma (HCC) is a highly heterogeneous disease displaying differences in angiogenesis, extracellular matrix proteins, the immune microenvironment and tumor cell populations. Additionally, genetic variations and epigenetic changes of HCC cells could lead to aberrant signaling pathways, induce cancer stem cells and enhance tumor progression. Thus, the heterogeneity in HCC contributes to disease progression and a better understanding of its heterogeneity will greatly aid in the development of strategies for the HCC treatment.     

Metformin inhibits prostate cancer cell proliferation,migration, and tumor growth through upregulation of PEDF expression

Metformin has been reported to inhibit the growth of various types of cancers, including prostate cancer. Yet the mode of anti-cancer action of metformin and the underlying mechanisms remain not fully elucidated. We hypothesized that the antitumorigenic effects of metformin are mediated through upregulation of pigment epithelium-derived factor (PEDF) expression in prostate cancer cells. In this report, metformin treatment significantly inhibited the proliferation and colony formation of prostate cancer cells, in a dose- and time-dependent manner. Meanwhile, Metformin markedly suppressed migration and invasion and induced apoptosis of both LNCaP and PC3 cancer cells. Metformin also reduced PC3 tumor growth in BALB/c nude mice in vivo. Furthermore, metformin treatment was associated with higher PEDF expression in both prostate cancer cells and tumor tissue. Taken together, metformin inhibits prostate cancer cell proliferation, migration, invasion and tumor growth, and these activities are mediated by upregulation of PEDF expression. These findings provide a novel insight into the molecular functions of metformin as an anticancer agent.     

色素上皮细胞衍生因子(PEDF)与代谢综合征(MS)关系的研究进展

 色素上皮细胞衍生因子(pigment epithelium derived factor,PEDF)是最先在视网膜色素上皮细胞培养液中被发现的一种分泌性糖蛋白。PEDF具有神经保护、抗炎、抗血管生成、抗肿瘤等生物学功能,对糖尿病微血管并发症包括糖尿病视网膜病变和肾病有保护作用。近年来发现肥胖、代谢综合征(metabolic syndrome,MS)患者的血清PEDF水平明显升高,PEDF与MS各组分密切相关,可能是MS发生发展的生物学标志。     

老年糖尿病患者血清Irisin和PEDF水平检测在早期肾损伤风险筛查中的应用价值

目的　研究老年糖尿病患者血清鸢尾素（Irisin）、色素上皮衍生因子（pigment epithelium-derived factor, PEDF）在早期肾损伤风险筛查中的应用价值。方法　收集2018年3月～2020年9月102例糖尿病患者,根据病情将102例患者分为A组（28例,单纯糖尿病）、B组[24例,早期糖尿病肾病（diabetic nephropathy, DN）]及C组（50例,临床DN）。比较三组血清Irisin和PEDF水平。根据肾小球滤过率（eGFR）是否<60ml/min·1.73 m2,记录肾损伤发生率。采用Cox风险回归模型分析糖尿病肾损伤的独立影响因素,以受试者工作曲线（receiver operating characteristic, ROC）分析血清Irisin,PEDF预测肾损伤的价值。结果　A,B和C三组患者血清Irisin,PEDF水平比较,差异均有统计学意义（F=34.47,48.64,均P<0.05）。102例糖尿病患者中,30例发生肾损伤,发生率为29.41%。血清Irisin（95%CI=0.24~0.65,HR=0.40,P<0.01）、血清PEDF（95%CI=1.77~2.30,HR=2.02,P<0.01）是老年糖尿病早期肾损伤的独立影响因素。血清Irisin和PEDF联合检测判断老年糖尿病患者发生肾损伤风险的AUC为0.77（95%CI=0.66~0.88,P<0.01）,敏感度和特异度分别为0.85和0.59。结论　血清Irisin,PEDF参与老年糖尿病病理进程,血清Irisin与PEDF联合检测作为早期筛查老年糖尿病患者发生肾损伤风险的方法,敏感度高。     

PEDF、CCR7和 MMP9在食管癌中的研究进展

色素上皮衍生因子（pigment epithelium - derived factor,PEDF）作为丝氨酸蛋白酶抑制剂超家族中的非抑制性成员,具有抗血管生成和抗肿瘤特性。趋化因子受体（CC chemokine receptor,CCR）7属趋化因子受体超家族,与肿瘤侵袭、淋巴结转移密切相关。基质金属蛋白酶（ matrix metalloproteinase,MMP）9为MMP 家族成员之一,通过基质降解和促血管生长参与肿瘤发生发展过程。本文就 PEDF、CCR7和 MMP9在食管癌的最新研究进展作一综述。     

Changes in pigment epithelium-derived factor expression following kainic acid induced cerebellar lesion in rat

Pigment epithelium-derived factor (PEDF) is a potent and broad-acting neurotrophic factor that protects various types of cultured neurons against glutamate excitotoxicity and induced apoptosis. The expression pattern and functions of PEDF in the central nervous system (CNS) remain largely undetermined. In this study, we analyzed the spatial and temporal expression of PEDF in normal and kainic acid (KA)-induced lesioned rat cerebellum using immunoblotting, immunohistochemistry and fluorescent in situ hybridization techniques. In normal rat cerebellum, PEDF protein and mRNA were mostly confined and co-localized with calbindin-positive cells in the Purkinje cell layer of the cerebellum, but not with glial fibrillary acidic protein (GFAP)-, 2′, 3′-cyclic nucleotide 3′-phosphodiesterase (CNPase)-, and isolectin B4-positive cells. Injection of KA into the right cellebellum caused severe loss of calbindin-positive Purkinje neurons, and an increased number of GFAP-positive astrocytes and isolectin B4-positive microglia was observed on the ipsilateral side of the lesioned cerebellum. Although the PEDF level on the ipsilateral side of the cerebellum was dramatically decreased 2 days after KA treatment, significantly elevation of PEDF levels was observed at 7 days. In agreement with these results, PEDF protein and PEDF mRNA expression were co-localized with GFAP-positive reactive astrocytes in the ipsilateral side 7 days after KA treatment. Although the mechanism by which PEDF is induced in reactive astrocytes remains unclear, the increase in PEDF expression in injured brain may form part of a compensation mechanism against neuronal degeneration.     

Administration of Pigment Epithelium-Derived Factor Inhibits Airway Inflammation and Remodeling in Chronic OVA-Induced Mice via VEGF Suppression

Purpose

Pigment epithelium-derived factor (PEDF) is a recently discovered antiangiogenesis protein. PEDF possesses powerful anti-inflammatory, antioxidative, antiangiogenic, and antifibrosis properties. It has been reported that PEDF can regulate vascular endothelial growth factor (VEGF) expression. This study aimed to evaluate whether recombinant PEDF protein could attenuate allergic airway inflammation and airway remodeling via the negative regulation of VEGF using a murine model of chronic ovalbumin (OVA)-induced asthma and BEAS-2B human bronchial epithelial cells.

Methods

In an in vivo experiment, mice sensitized with OVA were chronically airway challenged with aerosolized 1% OVA solution for 8 weeks. Treated mice were given injections of recombinant PEDF protein (50 or 100 µg/kg body weight) via the tail vein. In an in vitro experiment, we investigated the effects of recombinant PEDF protein on VEGF release levels in BEAS-2B cells stimulated with IL-1β.

Results

Recombinant PEDF protein significantly inhibited eosinophilic airway inflammation, airway hyperresponsiveness, and airway remodeling, including goblet cell hyperplasia, subepithelial collagen deposition, and airway smooth muscle hypertrophy. In addition, recombinant PEDF protein suppressed the enhanced expression of VEGF protein in lung tissue and bronchoalveolar lavage fluid (BALF) in OVA-challenged chronically allergic mice. In the in vitro experiment, VEGF expression was increased after IL-1β stimulation. Pretreatment with 50 and 100 ng/mL of recombinant PEDF protein significantly attenuated the increase in VEGF release levels in a concentration-dependent manner in BEAS-2B cells stimulated by IL-1β.

Conclusions

These results suggest that recombinant PEDF protein may abolish the development of characteristic features of chronic allergic asthma via VEGF suppression, providing a potential treatment option for chronic airway inflammation diseases such as asthma.     

色素上皮细胞衍生因子在眼科中的作用

色素上皮细胞衍生因子(pigmentepithelium-derivedfactor,PEDF)是由视网膜色素上皮细胞分泌的一种蛋白质,属于丝氨酸蛋白酶抑制基因家族,具有多种生物学活性,PEDF具有营养神经的功效,通过保护神经元免受神经毒性侵害而发挥神经营养因子之作用;PEDF还能抑制血管内皮细胞的移行,具有抗新生血管诱导因子的作用,它能够影响视网膜的分化,发育和成熟,对视网膜的机械损伤.光损伤和缺血性损伤有修复作用,是一种非常有前景的新生血管抑制剂。