Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.

Expression of Pigment Epithelium-derived Factor in Bladder Tumour Is Correlated with Interleukin-8 yet Not with Interleukin-1α

Pigment epithelium-derived factor （PEDF） is an antiangiogenic factor which is effective in tumour inhibition in a variety of tumours and has not yet been studied in bladder tumour before. In this study the expression of PEDF, interleukin-1α （IL-1α） and -8 （IL-8） in bladder tumours was investigated. Immunohistochemistry was performed on 64 bladder tumour and 23 normal uroepithelium samples. Expression change of the factors was compared with clinicopathological parameters. Correlations between PEDF, IL-1α and IL-8 were analyzed. None of the factors was in relation to gender, tumour occurrence, and size or onset pattern. PEDF （P=0.014） and IL-1α （P=0.049） expression was down-regulated with grade progression. PEDF expression was lower in normal uroepithelium than in papillary urothelial neoplasm of low malignant potential （PUNLMP） （P=0.000） and carcinoma （P=0.009） whilst IL-1α （P=0.000 and P=0.000 respectively） and IL-8 （P=0.000 and P=0.023 respectively） expression was higher in the same grouping. PEDF expression had a negative correlation with IL-8 in PUNLMP （P=0.049, r=-0.578） as well as in tumour grouping （P=0.033, r=-0.276）. Deranged expressional change of PEDF, IL-1α and IL-8 could be in relation to loss of differentiation from normal uroepithelium to papillary lesion and eventually to carcinoma.

Dan Huang Ming Mu Recipe Suppresses the Progression of Streptozotocin-induced Diabetic Retinopathy After Retinal Laser Photocoagulation in Brown Norway Rats via Down-regulating Vascular Endothelial Growth Factor and Up-regulating Pigment Epithelium-derived

Objective To analyze the effects of Dan Huang Ming Mu Recipe(DHMMR)(a pharmaceutical preparation from herbs and having the function of replenishing vital essence,removing heat,promoting blood circulation and excreting pathogenic water) on diabetic retinopathy(DR) after retinal laser photocoagulation through regulating the expression of vascular endothelial growth factor(VEGF) and pigment epithelium-derived factor(PEDF).Methods Forty male Brown Norway(BN) rats were randomly divided into blank group(group A,10 BN rats) and model group(30 BN rats).DR models were induced by 40 mg/kg streptozotocin(STZ) and the body weight and blood glucose of rats were monitored.After 12-week injection,fluorescein fundus angiography(FFA) and histopathological examination were detected to confirm the successful establishment of DR models.Subsequently,the right eyes of model group rats were conducted retinal laser photocoagulation with the left eyes having no retinal laser photocoagulation and rats of the model group were randomly divided into group B(the model control group),group C(the positive control group),and group D(the DHMMR group),with 10 rats in each group.Rats of the group A and the group B were given vehicle,and the group C were given calcium dobesilate suspension by gavage,and the group D were given DHMMR by gavage.After 4-week gavage,FFA was carried out to observe the fundus microvascular change.Then,the rats were sacrificed to do histopathological examinations and the serum levels of P-selectin,cAMP,cGMP,and the relative expression of the protein of VEGF and PEDF in retina were detected.Results After 12-week STZ injection,the blood glucose of the model group were pronouncedly higher than the blank group(P < 0.01).Fundus micro-hemangioma changes were observed in the rats of the model group through FFA,and the rats of the blank group did not see any changes.The pictures of HE staining showed that the retinal structure of the model group was more disordered than the blank group.After 4-week gavage,treatments with DHMMR showed dramatic reduction of serum levels of Pselectin,cAMP and cGMP compared with the group B(P < 0.01).FFA and histopathological examinations of DHMMR-treated rats revealed significantly suppression of retinal edema,fundus microvascular destruction and retinal destruction distinguishing from the group B.And the relative expression of VEGF protein of the group D and the group A was markedly lower than that of the group B(P < 0.01).The relative expression of PEDF protein of the group D and the group A was dramatically higher than that of the group B to the contrary(P < 0.01).Conclusions DHMMR demonstrates pronounced suppressive effects on the progression of DR after retinal laser photocoagulation,through down-regulating VEGF and upregulating PEDF.

Pigment epithelium-derived factor protects retinal ganglion cells from hypoxia-induced apoptosis by preventing mitochondrial dysfunction

AIM： To investigate the potential of pigment epitheliumderived factor（PEDF） to protect the immortalized rat retinal ganglion cells-5（RGC-5） exposed to Co Cl2-induced chemical hypoxia. METHODS： After being differentiated with staurosporine（SS）, RGC-5 cells were cultured in four conditions： control group cells cultured in Dulbecco ＇s modified eagle medium（DMEM） supplemented with 10% fetal bovine serum, 100 μmol/m L streptomycin and penicillin（named as normal conditions）; hypoxia group cells cultured in DMEM containing 300 μmol/m L Co Cl2; cells in the group protected by PEDF were first pretreated with 100 ng/m L PEDF for 2h and then cultured in the same condition as hypoxia group cells; and PEDF group cells that were cultured in the presence of 100 ng/m L PEDF under normal conditions. The cell viability was assessed by MTT assay, the percentage of apoptotic cells was quantified using Annexin V-FITC apoptosis kit, and intra-cellar reactive oxygen species（ROS） was measured by dichloro-dihydro-fluorescein diacetate（DCFH-DA） probe. The mitochondria-mediated apoptosis was also examined to further study the underlying mechanism of the protective effect of PEDF. The opening of mitochondrial permeability transition pores（m PTPs） and membrane potential（Δψm） were tested as cellular adenosine triphosphate（ATP） level and glutathione（GSH）. Also, the expression and distribution of Cyt C and apoptosis inducing factor（AIF） were observed.RESULTS： SS induced differentiation of RGC-5 cells resulting in elongation of their neurites and establishing contacts between outgrowths. Exposure to 300 μmol/m L Co Cl2 triggered death of 30% of the total cells in cultures within 24 h. At the same time, pretreatment with 100 ng/m L PEDF significantly suppressed the cell death induced by hypoxia（P〈0.05）. The apoptosis induced by treatment of Co Cl2 was that induced cell death accompanied with increasing intracellar ROS and decreasing GSH and ATP level. PEDF pretreatment suppressed these effects（P〈0.05）. Additionally, PEDF treatment inhibited the opening of m PTPs and suppressed decreasing of Δψm in RGC-5 cells, resulting in blocking of the mitochondrial apoptotic pathway.CONCLUSION： Pretreatment of RGC-5 cells with 100 ng/m L PEDF significantly decreases the extent of apoptosis. PEDF inhibits the opening of m PTPs and suppresses decreasing of Δψm. Moreover, PEDF also reduces ROS production and inhibits cellular ATP level＇s reduction. Cyt C and AIF activation in PEDF-pretreated cultures are also reduced. These results demonstrate the potential for PEDF to protect RGCs against hypoxic damage in vitro by preventing mitochondrial dysfunction.

Effect of local injection of pigment epithelium-derived factor on angiogenesis, inflammatory response and apoptosis in the retina of diabetic rats

Objective: To study the effect of local injection of pigment epithelium-derived factor (PEDF) on angiogenesis, inflammatory response and apoptosis in the retina of diabetic rats. Methods:Adult male SD rats were selected as experimental animals and randomly divided into control group, DM group and PEDF group, DM group and PEDF group were made into diabetes models through intraperitoneal injection of streptozotocin, and PEDF group were given local injection of PEDF. The contents of angiogenesis molecules and inflammatory response molecules as well as the expression of apoptosis genes in retinal tissue were measured after intervention. Results: mTOR, VEGF, VEGFR, Ang-2, Tie-2, NF-κB, COX2, iNOS, SDF-1 and CXCR4 contents as well as ASK1, JNK, p38MAPK and Caspase-3 mRNA expression in retinal tissue of DM group were significantly higher than those of control group whereas Survivin and Bcl-2 mRNA expression were significantly lower than those of control group;mTOR, VEGF, VEGFR, Ang-2, Tie-2, NF-κB, COX2, iNOS, SDF-1 and CXCR4 contents as well as ASK1, JNK, p38MAPK and Caspase-3 mRNA expression in retinal tissue of PEDF group were significantly lower than those of DM group whereas Survivin and Bcl-2 mRNA expression were significantly higher than those of control group. Conclusion: Local injection of PEDF has inhibitory effect on the angiogenesis, inflammatory response and apoptosis in the retina of diabetic rats.

Pigment epithelium derived factor(PEDF)prevents methyl methacrylate monomer-induced cytotoxicity in H9c2 cells

Acrylic bone cements are currently the most frequently and extensively used materials in orthopedic implant treatment. However, adverse effects have been described of acrylic bone cement on the cardiovascular system. In the present study, we examined the cytotoxicity of bone cement ingredient methyl methacrylate（MMA） to cardiomyocytes and the potential detoxifying effect of pigment epithelium-derived factor（PEDF） in H9c2 cells.We found that high concentration of MM A（〉 120 mmol/L） led to necrotic cell death in H9c2 cells. However, MMA at low concentrations（30-90 mmol/L） caused apoptosis. Pretreatment of PEDF prevented MMA-induced cytotoxicity. In addition, PEDF enhanced total superoxide dismutase activities, and decreased MMA-induced production of malonaldehyde. Furthermore, MMA-induced downregulation of Akt activity was suppressed by PEDF.PEDF also increased the levels of peroxisome proliferator activated receptor gamma（PPARγ）and lysophosphatidic acids（LPA） through PEDF receptor. These results indicated that PEDF inhibited MMA-induced cytotoxicity through attenuating oxidative stress, activating the phosphatidylinositol 3-kinase（PI3K）/Akt pathway and/or PEDF receptorLPA-PPARy pathways in H9c2 cells. PEDF may be explored as a candidate therapeutic agent for alleviating bone cement implantation syndrome during orthopedic surgery.

Autophagy: a new mechanism for regulating VEGF and PEDF expression in retinal pigment epithelium cells

AIM: To investigate the regulation of vascular endothelial growth factors(VEGF) and pigment epithelium-derived factor(PEDF) expression by autophagy in retinal pigment epithelium(RPE) cells on exposure to hypoxia. METHODS: ARPE-19, an RPE cell line, was treated as following: the control group was kept in a normoxic incubator; the hypoxia group was incubated in a hypoxic incubator with 1% O_2/5% CO_2/94% N_2 for 24 h; the hypoxia + 3-methyladenine(3-MA) group was pretreated with 10 mmol/L 3-MA for 1 h and then in the hypoxic incubator for 24 h; and the hypoxia + chloroquine(CQ) group was pretreated with 50 μmol/L CQ for 1 h and then in the hypoxic incubator for 24 h. The morphology and ultrastructure of the cells was observed by an inverted microscope or a transmission electronic microscope(TEM). Western blot was performed to assay the expression of autophagy-associated markers, including microtubule associated protein 1 light chain 3 B(LC3 B), Beclin-1, Atg5 and p62. The concentration of VEGF and PEDF in the culture supernatant was determined by ELISA, and the ratio of VEGF/PEDF was calculated. RESULTS: There were no obvious differences in cell morphology among different groups and autolysosomes could be observed in the cytoplasm in all groups. Compared to the control cells, the LC3 B-II/I ratio and levels of Beclin-1 and Atg5 were significantly increased and p62 level was significantly decreased in the hypoxia group. With the increase of VEGF and decrease of PEDF concentration, the VEGF/PEDF ratio was significantly increased in the hypoxia group compared to the control cells. The LC3 B-II/I ratio was significantly reduced by 3-MA treatment and increased by CQ treatment. The expressions of Beclin-1 and Atg5 were significantly reduced by 3-MA or CQ treatment, while expression of p62 was increased in the 3-MA or CQ treated cells. The concentration of VEGF was significantly decreased and PEDF increased, thereby the VEGF/PEDF ratio was decreased in the hypoxia + 3-MA group and hypoxia + CQ group compared with that in the hypoxia group. CONCLUSION: Hypoxia leads to elevated autophagy in RPE cells, and expression of VEGF and PEDF might be regulated by autophagy on exposure to hypoxia to further participate in regulating the formation of retinal neovascularization.

2型糖尿病合并白内障患者晶状体上皮细胞中PEDF和VEGF的表达及意义

目的:观察糖尿病合并年龄相关性白内障患者晶状体上皮细胞(LECs)中色素上皮衍生因子(PEDF)、血管内皮细胞生长因子(VEGF)的表达水平,探讨糖尿病合并年龄相关性白内障的发病机制。方法:回顾性研究。收集2020-08/2021-04在蚌埠医学院第一附属医院眼科就诊的年龄相关性白内障和2型糖尿病合并年龄相关性白内障患者各30例。所有患者白内障超声乳化术中收取术眼晶状体中央区5.5~6.0mm直径的前囊膜标本,采用蛋白免疫印迹法(Western-blot)检测LECs中PEDF、VEGF蛋白表达水平。实时荧光定量PCR(qRT-PCR)方法检测PEDF、VEGF mRNA的相对表达量。结果:两组患者LECs中均存在PEDF、VEGF的表达,2型糖尿病合并年龄相关性白内障组患者VEGF mRNA相对表达量为1.364±0.062,高于年龄相关性白内障组的1.000±0.0(P<0.01),PEDF mRNA的相对表达量为0.398±0.053,明显低于年龄相关性白内障组的1.000±0.0(P<0.001)。2型糖尿病合并年龄相关性白内障组患者LECs中VEGF和PEDF蛋白表达量为2.053±0.026、0.579±0.045,年龄相关性白内障组为1.680±0.064、1.058±0.007(均P<0.01)。结论:2型糖尿病合并年龄相关性白内障患者LECs中PEDF和VEGF表达水平发生变化,可能与糖尿病患者白内障的发生和发展有关。

PEDF在肿瘤中的研究进展

色素上皮源性因子(PEDF)是一种内源性的非抑制性丝氨酸蛋白酶抑制剂,具有营养神经、神经保护、抗血管生成、抗血管渗漏和促进凋亡等生物学活性。研究表明:PEDF可以直接或间接地抑制肿瘤,从而有望成为潜在的抗肿瘤策略。现就其分子结构,生理功能,抗新生血管及抗肿瘤等机制方面的研究进展进行综述。

PEDF在植入型凶险性前置胎盘中的表达及其对血管内皮细胞迁移、侵袭的影响

目的探讨色素上皮衍生因子(pigment epithelium-derived factor,PEDF)在植入型凶险性前置胎盘中的表达及其对脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)迁移、侵袭能力的影响。方法选择2014年7月~2015年7月福建省立医院剖宫产分娩的植入型凶险性前置胎盘(PA)组14例,前置胎盘(PP)组16例。采用免疫组化法检测两组胎盘的PEDF和VEGF的定位表达及微血管密度(microvascular vascular density,MVD);用RT-PCR及Western blot检测胎盘的PEDF和VEGF的mRNA和蛋白质表达;用ELISA检测外周血清中PEDF和VEGF水平。培养脐静脉内皮细胞,设阴性对照组和不同浓度的PDEF干预组,用平板划痕和Transwell侵袭实验检测HUVEC细胞的迁移和侵袭能力,用ELISA检测培养上清液中VEGF水平。结果 PA组与PP组相比,胎盘PEDF的mRNA和蛋白表达明显降低而VEGF则明显升高,差异均有统计学意义(均P<0.05)。胎盘PEDF表达与胎盘VEGF、MVD及胎盘植入深度呈负相关关系(均P<0.05),与外周血清PEDF水平呈正相关关系(P<0.05)。各PEDF干预组的迁移和侵袭细胞数显著低于阴性对照组(均P<0.05)。随干预浓度增加,HUVEC细胞的迁移和侵袭能力降低(均P<0.05)。结论 PEDF可以反映植入型凶险性前置胎盘的异常血管密度和植入程度,抑制血管内皮细胞的迁移和侵袭能力,可作为影像学检查的重要补充诊断方法和潜在的治疗切入点。

Predictive Value of Serum Vascular Endothelial Growth Factor and Pigment Epithelium-derived Factor in Ovarian Hyperstimulation Syndrome

Objective To explore whether the serum concentrations of vascular endothelial growth factor （VEGF） and pigment epithelium-derived factor （PEDF） could serve as the predictors of ovarian hyperstimulation syndrome （OHSS） in patients undergoing in vitro fertilization-embryo transfer （IVF-ET）. Methods Enzyme-linked immunoadsordent assay （ELISA） was employed to measure the serum concentrations of VEGF and PEDF on the day of hCG administration, oocyte retrieval and embryo transfer, respectively. Based on OHSS classification of the criteria of Golan, 85 patients were divided into three groups. Patients in group A （n=10） showed symptoms of severe OHSS and patients in group B （n=13） suffered from moderate OHSS. The control group （group C, n=62） contained patients without symptoms of OHSS as well as patients with mild OHSS.Results In groups A, B and C, serum concentrations of PEDF on the day of hCG administration （h-PEDF）（166.54 ± 102.81 pg/ml, 159.45 ±136. 77 pg/ml, 172.05±170.95 pg/ml, P=0.48）, oocyte retrieval （o-PEDF）（176.91 ± 103.37 pg/ml, 122.52± 92.54 pg/ml, 179.82±177.47 pg/ml, P=0.27） and embryo transfer （e-PEDF）（169.02± 240.08 pg/ml, 136.80 ±139.21pg/ml, 157.38 ±222.54 pg/ml, P=0.95）, h-VEGF （175.55 ± 103.54 pg/ml, 218.84 ±179.70pg/ml, 153.39±145.06 pg/ml, P=0.36） and o- VEGF （171.93 ± 128.55 pg/ml, 220.36±149.82 pg/ml, 138. 74 ±% 139.30 pg/ml, P=0. 15） showed no significant differences. There was a statistical difference in serum concentration of e-VEGF between group A （197.04±156.63 pg/ml） and group C （110.69±49.55 pg/ml）（P=0.008）. The serum level of estradiol showed a positive correlation with the count of large follicles （r=0. 744）. The ratios of h-VEGF/h-PEDF, o-VEGF/o-PEDF and e-VEGF/e-PEDF were calculated and showed a clear difference among groups A, B and C （4.04±3.39, 2.10±2.14, 1.05± 4.80, P〈0.001; 4.54 5.69, 2.29 ±1.67, 0.94 ±0.59, P〈0.001; 5.43±6.16, 1.81±1.36, 2.42±2.60, P=0.04）. Conclusion While neither serum concentrations of VEGF nor PEDF can be used as an OHSS predictor, the ratios of h-VEGF/h-PEDF, o-VEGF/o-PEDF and e-VEGF/e-PEDF may have great predictive value.

PEDF与VEGF检测在非小细胞肺癌诊断中的应用探讨

探讨色素上皮衍生因子(PEDF)与血管内皮生长因子(VEGF)检测对于非小细胞肺癌的诊断价值,并将上述两项指标作比较、联合分析。经应用受试者工作特征曲线分析并选取最佳诊断界值,若以血清PEDF蛋白浓度≤584ng/L为临界值,则其诊断非小细胞肺癌的灵敏度为72.3%,特异度为89.0%,准确度为79.8%;以血清VEGF蛋白浓度≥854ng/L为临界值,则其诊断非小细胞肺癌的灵敏度为80.0%,特异度为76.9%,准确度为78.4%。PEDF与VEGF检测相互串联(即:若血清PEDF蛋白浓度≤584ng/L且血清VEGF蛋白浓度≥854ng/L,则判定为非小细胞肺癌;反之则否),用以诊断非小细胞肺癌的灵敏度57.8%,特异度为97.7%;PEDF与VEGF检测相互并联(即:若血清PEDF蛋白浓度≤584ng/L或血清VEGF蛋白浓度≥854ng/L,则判定为非小细胞肺癌;反之则否),用以诊断非小细胞肺癌的灵敏度为94.5%,特异度为68.4%。血清PEDF或VEGF检测对于非小细胞肺癌诊断可能具有一定的辅助参考价值,上述两项指标联合检测可提高诊断的灵敏度或特异度。

2型糖尿病患者房水中PEDF，VEGF，Leptin水平测定的临床意义

目的检测2型糖尿病患者眼房水中色素上皮衍生因子（pigment epithelium-derived factor，PEDF）、血管内皮生长因子（vascular endothelial growth factor，VEGF）和瘦素（Leptin）的含量，并探讨其临床意义。方法对70例2型糖尿病患者房水中PEDF和VEGF的含量采用双抗体夹心酶联免疫吸附（ELISA）法检测，Leptin含量采用放射免疫法（RIA）检测。根据散瞳眼底检查和眼底荧光素血管造影检查后，实验组分为：无糖尿病视网膜病变组（NDR）22例，单纯型糖尿病性视网膜病变组（BDR）28例，增生型糖尿病性视网膜病变组（PDR）20例，对照组为健康的老年性白内障患者20例。结果NDR组，BDR组，PDR组的房水VEGF含量分别为250．32±26．77，300．11±58．89，496．23±91．06pg／ml；PEDF含量分别为0．41±0．55，0．37±0．42，0．29±0．19ng／ml；Leptin含量分别为69．80±21．37，155．08±32．76，230．27±56．92pg／ml。对照组房水VEGF含量为144．69±26．55pg／ml，PEDF含量为0．52±0．47ng／ml，Leptin含量为43．62±20．02pg／ml，对照组与实验组比较差异均有统计学意义（F=118．62，P〈0．01；F=-110．53，P〈0．01；F=101．22，P〈0．01）。4组房水VEGF，PEDF，Leptin含量有明显增加的趋势。房水中的VEGF与PEDF，Leptin含量有相关性（r=0．995，P〈0．01；r=0．776，P〈0．01）；房水中VEGF，PEDF，Leptin含量与糖尿病患者的病程及糖尿病视网膜病变的严重程度有相关性（r=0．722，P〈0．01；r=0．716，P〈0．01），（r=-0．869，P〈0．01；r=-0．865，P〈0．01），（r=0．776，P〈0．01；r=0．765，P〈0．01）。结论VEGF，PEDF，Leptin在糖尿病视网膜病变的形成过程中有重要作用，且VEGF与PEDF，VEGF与Leptin之间有相关性。

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。

PEDF对胎盘位置附着异常中异常胎盘微血管床形成的研究

目的探讨色素上皮衍生因子(PEDF)对胎盘位置附着异常中胎盘微血管床形成的影响。方法选择2014年6月至2015年8月我院剖宫产分娩的孕妇48例,其中胎盘植入(PA组)16例,前置胎盘(PP组)16例,对照组16例。胎盘进行病理学检查,免疫组化检测三组胎盘组织的MVD;RT-PCR及Western Blot检测胎盘组织中PEDF和VEGF的m RNA和蛋白质表达。结果①三组胎盘组织中PEDF及VEGF蛋白含量、PEDF及VEGF m RNA含量及MVD比较,差异均有统计学意义(P<0.05)。②胎盘中PEDF与VEGF、MVD均呈负相关关系(r=-0.778,P=0.000;r=-0.827,P=0.000)。③胎盘血管情况:PA组绒毛血管数量丰富,管径粗大,侵及肌壁间血管;PP组绒毛间血管增生程度有所减轻,未侵及肌层;对照组则无上述变化。结论①胎盘位置异常组中胎盘的PEDF表达过低是导致VEGF负性调节不足以及胎盘病理性血管形成的原因,参与了胎盘位置异常的发生。②三组胎盘中PEDF含量均有显著差异,提示PEDF含量可以反映异常胎盘血管的侵袭程度。

Ultrasound-mediated microbubble delivery of pigment epithelium-derived factor gene into retina inhibits choroidal neovascularization

Background Many studies have suggested that the imbalance of angiogenic factor and anti-angiogenic factor expression contributes significantly to the development of choroidal neovascularization （CNV）, and ultrasound microbubble combination system can increase the gene transfection efficiency successfully. This study was designed to investigate whether ultrasound-mediated microbubble destruction could effectively deliver therapeutic plasmid into the retina of rat, and whether gene transfer of pigment epithelium-derived factor （PEDF） could inhibit CNV.Methods Human retinal pigment epithelial cells were isolated and treated either with ultrasound or plasmid alone, or with a combination of plasmid, ultrasound and microbubbles to approach feasibility of microbubble-enhanced ultrasound enhance PEDFgene expression; For in vivo animal studies, CNV was induced by argon lasgon laser in rats. These rats were randomly assigned to five groups and were treated by infusing microbubbles attached with the naked plasmid DNA of PEDF into the vitreous of rats followed by immediate ultrasound exposure （intravitreal injection）; infusing liposomes with the naked plasmid DNA of PEDF into the vitreous （lipofectamine ＋ PEDF）; infusing microbubbles attached with PEDF into the orbit of rats with ultrasound irradiation immediately （retrobular injection）; infusing microbubbles attached with PEDF into the femoral vein of rats with exposed to ultrasound immediately （vein injection）. The CNV rats without any treatment served as control. Rats were sacrificed and eyes were enucleated at 7, 14, and 28 days after treatment. Gene and protein expression of PEDF was detected by quantitative real-time RT-PCR, Western blotting and immunofluorescence staining, respectively. The effect of PEDF gene transfer on CNV was examined by fluorescein fundus angiography.Results In vitro cell experiments showed that microbubbles with ultrasound irradiation could significantly enhance PEDF delivery as compared with microbubbles or ultrasound alone. In the rat CNV model, transfection efficiency mediated by ultrasound/microbubbles was significantly higher than that by lipofectamine-mediated gene transfer at 28 days after treatment. The study also showed that with the administration of ultrasound-mediated microbubbles destruction, the CNV of rats was inhibited effectively. Conclusions Ultrasound-microbubble technique could increase PEDF gene transfer into rats＇ retina and chorioid, in association with a significant inhibition of the development of CNV, suggesting that this noninvasive gene transfer method may provide a useful tool for clinical gene therapy.

增殖性糖尿病视网膜病变患者玻璃体液中PEDF与TAOC的关系研究

目的探讨增殖性糖尿病视网膜病变(proliferative diabetic retinopathy,PDR)患者玻璃体液中色素上皮衍生因子(pigment epithelium-derived factor,PEDF)与总抗氧化能力(total anti-oxidant capacity,TAOC)的关系。方法选择行玻璃体切割术的增殖性糖尿病视网膜病变患者20例(20眼),其中PDR合并玻璃体出血组12眼,PDR无玻璃体出血组8眼。非糖尿病患者18例(18眼)作为对照组。采用ELISA方法测定玻璃体液中PEDF和TAOC的水平,并行统计学分析。结果与对照组比较,PDR患者玻璃体液中的TAOC明显降低(P<0.01)。玻璃体液中PEDF水平与TAOC呈正相关(r=0.35,P<0.05),和对照组呈正相关(r=0.39,P<0.05)。无玻璃体出血组PDR患者玻璃体液中PEDF水平与对照组和合并玻璃体出血组比较明显降低(P<0.05)。结论玻璃体液中PEDF水平与TAOC密切相关。PEDF可作为眼内源性抗氧化物并对PDR起到保护作用。

Inhibition of choroidal neovascularization by lentivirusmediated PEDF gene transfer in rats

AIM: To evaluate the effects of lentivirus-mediated pigment epithelium-derived factor (PEDF) gene transfer performed in treatment of rats with established choroidal neovascularization (CNV), and investigates the mechanism by which PEDF inhibits CNV in rats. METHODS: Brown Norway (BN) rats (n=204) were induced by exposure to a laser, and then randomly assigned to 3 groups: no treatment; treatments with intravitreal injection of lentivirus-PEDF-green fluorescent protein (GFP) or lentivirus-control GFP (free fluorescent protein). Following induction and treatment, the CNV tissue was assessed for form, size and vessel leakage by fluorescein fundus angiography (FFA), optical coherence tomography (OCT), histopathology, and examination of choroidal flat mounts. VEGF, Flk-1, and PEDF expression were evaluated by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: A stable laser-induced rat model of CNV was successfully established, and used to demonstrate lentivirus-mediated REDO gene transfer by intravitreal injection. Expression of green fluorescence labelled PEDF was observed in the retina up to 28d after injection. An intravitreal injection of lentivirus-PEDF-GFP at 7d led to a significant reduction in the size, thickness and area of CNV showed by FFA, OCT and choroidal flat mounts. PEDF was up-regulated while VEGF and Flk-1 were down-regulated in the lentivirus-PEDF-GFP group. The differences in VEGF and Flk-1 expression in the control and lentivirus-PEDF groups at 7, 14, 21 and 28d after laser induction were all statistically significant. CONCLUSION: Lentivirus-mediated PEDF gene transfer is effective for use in treatment of laser-induced CNV, and PEDF exerts its therapeutic effects by inhibiting expression of VEGF and Flk-1.

Anti-inflammatory effects of a synthetic peptide derived from pigment epithelium-derived factor on H2O2-induced corneal injury in vitro

Background The common pathological characteristics of corneal injury include inflammatory factors activation, vascular endothelial cells or inflammatory cells infiltration into lesions, corneal edema, corneal neovascularization （CNV）, and scar formation. PEDF-34 is the functional fragment of pigment epithelium-derived factor （PEDF） that has anti-angiogenic and anti-inflammatory properties and contains an N-terminal 34-amino acid peptide. This study was to investigate the anti- inflammatory effects of PEDF-34 on H202-induced corneal injury in vitro. Methods After cultured in H202 （0.1 mmol/L） for 2 hours, human corneal fibroblasts （HCFs） and human umbilical vein endothelial cells （HUVECs） were treated with PEDF-34-nanoparticles （NPs） at different concentrations （0.1, 0.5, 1.0, 2.0 μg/ml） or 2.0 μg/ml controI-NPs for 24 hours. The viable cells were quantified using the MTT assay. Western blotting or ELISA analysis was performed for measuring the human vascular endothelial growth factor （VEGF） and intercellular adhesion molecule-1 （ICAM-1） expression of both HCFs and HUVECs. VEGF and nuclear factor KB （NF-KB） mRNA levels of HCFs were semi-quantified by RT-PCR. Results The survival rates of HCFs or HUVECs stimulated by H202 did not decrease significantly （P 〉0.05） compared to those in the normal conditions. As compared to controI-NP group, PEDF-34-NPs had dose-dependent inhibitive effect on HUVECs with the MTT assay, but not HCFs. Western blotting analysis showed that the VEGF and ICAM-1 levels in the HCFs and HUVECs stimulated by H202 were significantly higher than those in the normal conditions, which were decreased dramatically in those treated with PEDF-34-NPs. RT-PCR analysis revealed that the VEGF mRNA and NF-KB mRNA levels increased in H202-stimulated HCFs, while both of them decreased in PEDF-34-NP groups dose dependently. Conclusions PEDF-34-NPs may play an important role in regulating the NF-kB pathway, inhibiting inflammatory activity. PEDF-34-NPs may be a potential new drug for treating corneal injury in the future.

Protective effects of piperine on the retina of mice with streptozotocin-induced diabetes by suppressing HIF-1/VEGFA pathway and promoting PEDF expression

AIM:To evaluate the protective mechanisms of piperine in the retina of mice with streptozotocin-induced diabetes.METHODS:In experiments in vitro,stimulation by chemical hypoxia was established in ARPE-19 cells.Then,the expression of hypoxia-inducible factor-1α(HIF-1α),vascular endothelial growth factor A(VEGFA),and pigment epithelium-derived factor(PEDF)was assessed at the m RNA and protein levels.In experiments in vivo,diabetes mellitus was established by intraperitoneally injecting 150 mg/kg streptozotocin once.After 3 wk of the onset of diabetes,15 mg/kg piperine was intraperitoneally injected once daily for 1 or 3 wk.Then,the retinal morphology and m RNA and protein expression were assessed.RESULTS:In hypoxia,1-100μmol/L piperine significantly decreased the expression of VEGFA m RNA and increased the expression of PEDF m RNA without affecting HIF-1αm RNA.Meanwhile,100μmol/L piperine substantially decreased the protein level of VEGFA and increased the protein level of PEDF.The HIF-1αprotein level was also hampered by piperine.In the diabetic retina of mice,the morphological damage was alleviated by piperine.Likewise,the retinal vascular leakage was substantially decreased by piperine.Further,the protein levels of HIF-1αand VEGFA were significantly reduced by piperine.Moreover,the level of the antiangiogenic factor of PEDF dramatically increased by piperine.CONCLUSION:Piperine may exert protective effects on the retina of mice with diabetes via regulating the pro-antiangiogenic homeostasis composed of HIF-1/VEGFA and PEDF.