TIMP-2基因转染FDM豚鼠后极部巩膜MMP-2蛋白早期动态表达

目的探讨外源性基质金属蛋白酶组织抑制剂-2(tissue inhibitor of matrix metalloproteinases,TIMP)对豚鼠形觉剥夺性近视(form deprivation myopia,FDM)眼后极部巩膜基质金属蛋白酶-2(matrix metalloproteinases-2,MMP-2)蛋白表达的影响。方法单眼形觉遮盖法制备FDM豚鼠右眼模型,45只豚鼠分为TIMP-2组、空质粒组和生理盐水组,每组15只,右眼脉络膜上腔内分别注射转染TIMP-2基因的脂质体、空质粒和生理盐水,左眼暴露为自身对照;另15只豚鼠持续遮盖右眼,不作任何处理,为对照组。各组分别于注药后的第2天、第7天和第14天处死豚鼠,取眼球后极部巩膜组织,用明胶酶谱法检测MMP-2蛋白的表达。结果转染第2天、第7天和第14天TIMP-2组豚鼠后极部巩膜MMP-2酶原及活性酶的相对表达量分别为0.9012±0.0056和0.3006±0.0051、0.8876±0.0060和0.2858±0.0065、0.8915±0.0068和0.2915±0.0076,表达均降低,与自身对照组、对照组组间比较,差异均有统计学意义(均为P<0.05),而空质粒组和生理盐水组与对照组相比,转染后第2天、第7天和第14天差异均无统计学意义(均为P>0.05)。TIMP-2组豚鼠后极部巩膜MMP-2酶原及活性酶表达水平从第2天开始降低,第7天最低,第14天时略有回升,第2天与第7天、第14天之间差别均有统计学意义(均为P<0.05),第7天与第14天比较差异无统计学意义(P>0.05)。结论外源性TIMP-2基因注入FDM豚鼠后,早期即可有效抑制后极部巩膜MMP-2蛋白的表达,减缓巩膜的重塑,但随时间的延长抑制作用逐渐减弱。     

外源性视黄酸对鸡后巩膜基质MMP-2/TIMP-2表达作用的动态观察

目的探讨外源性视黄酸(RA)对小鸡后极部巩膜基质MMP-2表达的作用。方法新孵化来亨鸡90只随机分为三组,实验组右眼球后注射RA,隔日1次;左眼为自身对照;阴性对照组右眼球后注射生理盐水;正常对照组不做任何处理。于4、8、14 d时各组取10只测量眼轴和屈光度后摘取眼球,采用一步法逆转录-多聚酶链反应(RT-PCR法)检测每组小鸡后极部巩膜MMP-2与TIMP-2 mRNA转录水平。结果实验组眼轴明显延长,屈光度增加,后极部巩膜MMP-2 mRNA转录明显增高,与正常组与阴性对照组比较,差异有显著性统计学意义(P<0.01)。注射后随时间延长眼轴及屈光度逐渐增加,组内不同时间差异有显著性统计学意义(P<0.01),MMP-2 mRNA转录上调,组内不同时间差异无显著性统计学意义(P>0.05)。TIMP-2 mRNA转录与之相反。自身对照组眼轴及屈光度均有增加,MMP-2 mRNA转录较同龄正常对照组有轻度上调,TIMP-2有下调,与正常组与阴性对照组比较,差异有显著性统计学意义(P<0.01)。结论外源性RA能够调节巩膜MMP-2/TIMP-2的转录,并可能通过这一途径促进眼轴及屈光度的增加。     

TIMP-2基因转染豚鼠巩膜成纤维细胞基质金属蛋白酶2及其抑制剂表达

目的观察转染基质金属蛋白酶2抑制剂(tissue inhibitor of matrix metalloproteinase2,TIMP-2)基因的豚鼠巩膜成纤维细胞不同时间增生能力及基质金属蛋白酶2(matrix metalloproteinase2,MMP-2)和TIMP-2的表达,探讨基因治疗近视的可行性。方法随机选取三色健康豚鼠,组织块法体外培养原代巩膜成纤维细胞,免疫组织化学法进行波形蛋白的鉴定,取第3～6代细胞进行实验。分子克隆构建携带TIMP-2基因的真核表达载体,转染豚鼠巩膜成纤维细胞,MTT法观察转染后12h、24h、48h、3d、5d、7d细胞增生能力。提取总RNA,二步法逆转录-聚合酶链反应检测MMP-2mRNA及TIMP-2mRNA的表达水平。结果豚鼠巩膜成纤维细胞原代、传代培养生长良好,波形蛋白鉴定阳性。转染3d、5d、7d TIMP-2基因转染组成纤维细胞的增生速度分别为0.6724±0.0092、0.7963±0.0060、0.8462±0.0064,明显快于正常对照组成纤维细胞(0.5810±0.0120、0.6525±0.0072、0.7129±0.0132),差异均具有显著统计学意义(均为P<0.01)。转染48h MMP-2mRNA表达即开始减少,转染3d时表达明显减少,达到最低,除转染12h与24h之间外,转染组与正常对照组、各转染不同时间组间MMP-2mRNA表达差异均有统计学意义(均为P<0.05)。TIMP-2mRNA表达在转染48h时即开始增加,除12h与24h外,转染组与正常对照组、各转染不同时间组间TIMP-2mRNA表达差异均有统计学意义(均为P<0.05)。结论转染TIMP-2基因对豚鼠巩膜成纤维细胞有促增生作用,TIMP-2基因转染豚鼠巩膜成纤维细胞抑制MMP-2mRNA的表达,可在一定程度上阻止近视发展中巩膜组织的丢失与重塑。     

康柏西普对豚鼠形觉剥夺性近视的干预作用及相关机制分析

目的　探讨抗新生血管生长因子融合蛋白康柏西普（Conbercept）球结膜下注射对豚鼠形觉剥夺性近视的干预作用及其可能的作用机制。方法　普通级3周龄断乳花色豚鼠48只随机分为空白对照组、单纯手术组、生理盐水组、Conbercept组，每组各12只。其中空白对照组豚鼠不作处理，单纯手术组、生理盐水组、Conbercept组使用眼睑缝合法遮盖右眼，生理盐水组、Conbercept组分别在缝合时、缝合后7 d右眼球结膜下注射0.05 mL生理盐水、0.5 mg（0.05 mL）Conbercept。记录各组眼睑缝合前及缝合后7 d、14 d时的眼轴长度、屈光度，并取后极部巩膜组织采用RT-PCR、Western blot方法检测各组豚鼠巩膜中基质金属蛋白酶2（MMP-2）、基质金属蛋白酶抑制剂-2（TIMP-2）、转化生长因子（TGF）-β1、TGF-β2 mRNA和蛋白表达情况。结果　眼睑缝合后7 d、14 d，单纯手术组较空白对照组豚鼠右眼眼轴长度、屈光度均增加，MMP-2、TGF-β2 mRNA和蛋白相对表达量均增加，TGF-β1、TIMP-2相对表达量均减少，差异均具有统计学意义（均为P<0.05）；单纯手术组与生理盐水组各指标相比差异均无统计学意义（均为P>0.05)。眼睑缝合后7 d，与生理盐水组相比，Conbercept组眼轴长度、屈光度及TIMP-2、TGF-β1 mRNA和蛋白相对表达量差异均无统计学意义（均为P>0.05），MMP-2、TGF-β2 mRNA和蛋白相对表达量均减少，差异均有统计学意义（均为P<0.05）；眼睑缝合后14 d时，与生理盐水组相比，Conbercept组眼轴长度、屈光度及MMP-2、TGF-β2、TGF-β1 mRNA和蛋白相对表达量差异均有统计学意义（均为P<0.05）。结论　0.5 mg Conbercept球结膜下注射可延缓豚鼠形觉剥夺性近视形成，且可能是通过调节巩膜中的MMP-2、TGF-β1、TGF-β2表达而发挥作用。     

豚鼠形觉剥夺早期后极部巩膜基质金属蛋白酶2及其抑制剂动态表达

目的探讨豚鼠形觉剥夺性近视（form-deprivation myopia, FDM ）早期后极部巩膜基质金属蛋白酶2（matrix metalloproteinase-2, MMP-2）及基质金属蛋白酶抑制剂2（tissue inhibitor of matrix metalloproteinase-2,TIMP-2）mRNA的表达。方法4周龄三色豚鼠50只,随机分成实验组和正常对照组各25只,实验组又随机分为5组,单眼形觉剥夺（monocular deprivation, MD）右眼1、4、7、14、21d制备FDM动物模型,未遮盖眼为自身对照组。各组豚鼠进行检影验光和A超测量眼轴长度。提取后极部巩膜总RNA,二步法逆转录聚合酶链反应检测各组后极部巩膜MMP-2及TIMP-2mRNA的表达水平。结果除1d外,各组MD后极部巩膜MMP-2mRNA的表达与正常对照组、自身对照组差异均有统计学意义（P〈0,05）,MD组间差异也有统计学意义（P〈0．01）;而TIMP-2mRNA的表达则逐渐下降。各自身对照组MMP-2、TIMP-2mRNA的表达与MD组变化趋势大致相同。结论MMP-2／TIMP-2之间动态平衡失调可能是启动豚鼠FDM巩膜细胞外基质早期主动重塑的重要因素。（中国跟耳鼻喉科杂志,2010,10：75—78）     

TIMP-2基因转染后豚鼠形觉剥夺眼后极部巩膜Ⅰ型胶原和纤维连接蛋白的表达

背景细胞外基质（ECM）蛋白和酶参与眼球后极部巩膜主动的重塑过程,主要通过影响I型胶原蛋白（Col-Ⅰ）纤维连接蛋白（FN）发挥作用。目的通过对形觉剥夺性近视（FDM）豚鼠经脉络膜上腔注入转染有TIMP-2基因的脂质体,观察基质金属蛋白酶抑制剂-2（TIMP-2）对细胞外基质中Ⅰ型胶原蛋白（Col-Ⅰ）和FNmRNA表达的影响。方法半透明眼罩遮盖36只豚鼠的右眼14d建立FDM动物模型,用随机数字表法分组后分别于右眼脉络膜上腔注入5p,1TIMP-2脂质体质粒、空质粒和生理盐水,每组12只眼,左眼为自身对照。另12只豚鼠持续遮盖右眼为模型对照组。分别于脉络膜上腔注药后的2、7、14d过量麻醉处死豚鼠,获取眼球后极部巩膜组织,用RT-PCR法分别检测各组豚鼠眼巩膜组织中Col-Ⅰ和FNmRNA的表达。结果TIMP-2组豚鼠后极部巩膜Col-Ⅰ mRNA表达降低,FNmRNA表达升高,与自身对照相比差异均有统计学意义（P〈0．05）。注入TIMP-2后,Col-I mRNA表达水平从第2天开始升高,第7天达到高峰,第14天时有所回落;FNmRNA表达水平则呈相反变化。二者在第7天、第14天的表达与其他3组间比较差异均有统计学意义（P〈0．05）。C01．ImRNA和FNmRNA表达水平在注射后第7天与第2天或第14天比较差异均有统计学意义（P〈0．01）。结论TIMP-2注入FDM豚鼠脉络膜上腔可上调Col-I mRNA表达,下调FNmRNA表达,早期可有减缓豚鼠FDM巩膜重塑的作用。     

形觉剥夺下雏鸡后极部巩膜中MMP-2 TIMP-2及RARβ表达变化

目的 分析雏鸡形觉剥夺性近视眼及形觉剥夺性近视恢复眼后极部巩膜中基质金属蛋白酶2(matrix metallopmteinaae 2,MMP-2)、组织金属蛋白酶抑制剂2(tissue inhibitor of matrix metallopro-teinase 2,TIMP-2)及视黄酸受体-β(retinoic acid receptor-β,RARβ)的水平及其相关性.方法 选用新孵出家鸡75只,半透明眼罩遮盖的方法对左眼进行形觉剥夺,分为形觉剥夺组,遮盖14d;形觉剥夺恢复组,遮盖11d后,去遮盖3d.右眼为对照眼.取直径8mm的后极部眼组织块,分离出巩膜纤维层和软骨层.RT-PCR检测MMP-2、TIMP-2及RARβ mRNA的相对含量,并将MMP-2、TIMP-2 mRNA水平分别与RARβ的mRNA水平作线性相关分析.结果 形觉剥夺14d后,纤维层中MMP-2的表达增强(P<0.01),TIMP-2的表达减弱(P<0.01);去剥夺3d后,MMP-2的表达减弱(P<0.01),而TIMP-2的表达恢复到接近对照眼的水平(P>0.05).软骨层表达没有明显变化.形觉剥夺14d后,RARβ的表达均增强,但纤维层中的表达更为强烈(P<0.01).去剥夺3d后,RARβ的表达均明显下降(P<0.01).MMP-2与RARβmRNA水平呈正相关(P<0.05,r=0.944);TIMP-2与RARβmRNA水平呈负相关(P<0.05,r=-0.863).结论 雏鸡形觉剥夺性近视眼及形觉剥夺性近视恢复眼后极部巩膜纤维层中MMP-2、TIMP-2及RARβ的水平均发生明显变化,并有相关性.RARβ参与了巩膜纤维层细胞外基质的降解过程.     

外源性视黄酸对人巩膜成纤维细胞MMP-2及TIMP-2 mRNA水平的影响

目的 研究外源性视黄酸（RA）对人巩膜成纤维细胞（HSF）生长的调控,以及对基质金属蛋白酶2（MMP-2）和基质金属蛋白酶2组织抑制剂（TIMP-2）mRNA水平的影响.方法 体外培养HSF,取第5～7代细胞,经10^-10、10^-9、10^-8、10^-7、10^-6mol/L浓度的RA作用6 d后,进行细胞计数,观察RA对HSF生长的调控情况;用Real-time PCR检测RA作用后HSF中MMP-2、TIMP-2的mRNA水平.对不同浓度组问比较采用单因素方差分析,两两比较采用t检验.结果 RA作用HSF 6 d后,浓度≥10^-9 mol/L RA组对细胞的生长抑制作用差异均有统计学意义（P〈0.05）,随着RA浓度增高,细胞数量逐渐减少,抑制作用呈剂量效应.RA作用6 d后,RA≥10^-8 mol/L时,HSF中MMP-2 mRNA水平有升高趋势,但各组差异无统计学意义（P〉0.05）;RA≥10^-9 mol/L时,TIMP-2 mRNA水平下降（P〈0.05）.结论 RA能够抑制HSF的生长,并可能通过调控TIMP-2的mRNA水平,使巩膜主动重塑.     

牛磺酸对大鼠视神经损伤后MMP-2和MMP-9表达的促进作用

目的观察视神经损伤后基质金属蛋白酶(matrix metalloproteinases,MMP)-2和MMP-9的表达及牛磺酸对其表达的影响,探讨牛磺酸在视神经再生修复方面的作用。方法 84只大鼠随机分为4组,正常组(12只)不作处理,对照组、预治疗组、治疗组(每组24只)建立大鼠视神经不完全损伤模型,预治疗组于造模前3d、治疗组于造模后1h开始每天1次给予体积分数5%牛磺酸腹腔注射,对照组造模后1h每天1次给予等量蒸馏水腹腔注射。各组分别于伤后3d、7d、14d、28d取视神经采用免疫组织化学法检测MMP-9平均光密度值,用逆转录-聚合酶链反应(RT-PCR)检测MMP-2mRNA。结果对照组、预治疗组、治疗组视神经损伤后MMP-9和MMP-2mRNA的表达较正常组均增高,预治疗组及治疗组与对照组相比,各时间点MMP-9和MMP-2mRNA的阳性表达均明显升高(均为P<0.05)。在视神经损伤后3d时预治疗组MMP-9光密度值为39.53±4.05、MMP-2mRNA灰度值为1.746±0.268,其阳性表达与治疗组的MMP-9光密度值32.96±3.62、MMP-2mRNA灰度值1.303±0.289相比均明显增高(均为P<0.05),其后两组相近,差异均无统计学意义(均为P>0.05)。结论视神经损伤后MMP-2和MMP-9的表达增强,牛磺酸治疗可以提高视神经组织中MMP-2、MMP-9的表达,对视神经损伤后的再生修复有一定的促进作用。     

外源性视黄酸对鸡后巩膜基质MMP-2表达作用的动态观察

注射后随时间延长眼轴及屈光度逐渐增加,不同时间组间差异极显著(P<0.01),MMP-2mRNA表达上调,不同时间组间差异无显著性(P>0.05)。自身对照组眼轴及屈光度均有增加,MMP-2mRNA表达较同龄正常对照组有轻度上调,组间差异极显著(P<0.01)。免疫组化显示,MMP-2表达的增高主要在巩膜成纤维细胞层。结论外源性视黄酸能够上调巩膜MMP-2的转录和表达,并可能通过这一途径促进眼轴及屈光度的增加。     

硫化氢对H2O2诱导的视网膜神经节细胞氧化损伤的保护作用

目的 探讨硫化氢对H2O2诱导的视网膜神经节细胞(retinal ganglion cell,RGC)-5氧化损伤的保护作用及可能机制.方法 将RGC-5分为4组,RGC-5组为正常对照组;RGC-5+ H2O2组:RGC-5在500 μmol·L-H2 O2中培养24 h诱导氧化损伤;RGC-5+ NaHS+ H2O2组:RGC-5置于50μmol·L-1NaHS中30 min后在500 μmol·L-1H2O2中培养24 h;RGC-5+ NaHS组:RGC-5置于50 μmol·L-1 NaHS中30 min.Western blot检测线粒体内、外细胞色素C和视神经萎缩蛋白1(optic atrophy 1,OPA1)表达;用荧光探针JC-1检测线粒体膜电位,用透射电镜观察线粒体形态.结果 与RGC-5组相比,RGC-5+ H2O2组RGC-5细胞质内细胞色素C表达增加,而线粒体内的OPA1表达减少(均为P＜0.05).RGC-5组和RGC-5+ NaHS+ H2O2组线粒体内、外细胞色素C的表达差异均无统计学意义(均为P＞0.05).与RGC-5组相比,RGC-5+ NaHS组细胞质内细胞色素C表达减少,而线粒体内的细胞色素C表达增加(均为P＜0.05).与RGC-5组相比,RGC-5+H2O2组RGC-5细胞质内OPA1表达显著增加,而线粒体内的OPA1表达减少(均为P＜0.05).RGC-5+ NaHS+H2O2组和RGC-5+NaHS组RGC6线粒体内、外OPA1的表达与RGC-5组相似,差异均无统计学意义(均为P＞0.05).RGC6 +H2O2组线粒体膜电位与其他3组比较明显下降,其余3组间线粒体膜电位比较,差异无统计学意义(P＞0.05).RGC-5+H2O2组线粒体肿胀呈球状,而其余3组线粒体肿胀不明显.结论 硫化氢可能通过阻止线粒体释放OPA1来减轻H2O2导致的RGC-5氧化损伤.     

MMP-2 gene polymorphisms in type 2 diabetes mellitus diabetic retinopathy

AIM: To study the association between polymorphisms of the MMP-2 gene and diabetic retinopathy (DR). METHODS:MMP-2 C-1306T and C-735T SNPs was genotyped by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) analysis in 151 DR patients and 150 healthy individuals served as control. RESULTS: There is no significant difference between the patient and control groups in allele or genotype distributions of MMP-2 C-735T (P=0.263 and P=0.248). Also, there is no significant difference between the patient and control in allele of MMP-2 C-1306T (P=0.03). However the result has significant deviation of C/C, C/T, T/T genotypic frequencies between the patient and control groups in MMP-2 C-1306T (P=0.008). We found that subjects with the MMP-2 C-1306T genotype had an overall 2-fold increase in the risk of developing DR [adjusted odds ratio (OR)=2.446; 95% confidence interval (CI)=1.239-4.829] compared with those with the T-1306T or C-1306T genotype. Stratification analysis showed that the MMP-2 -1306C/T and -735C/T SNPs are not associated with the development of NPDR to PDR of DR in North Chinese Han population. CONCLUSION: MMP-2 C-1306T genotypes may be associated with DR development in the Chinese population. However, there is no relationship between the MMP-2 C-735T genotypes with the development of DR.     

Genotype-phenotype correlation in X-linked retinitis pigmentosa 2 (RP2)

In order to understand the underlying molecular genetic defect causing aniridia in India, eight probands from sporadic cases were screened for all 14 exons of the PAX6 gene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). Direct sequencing of the SSCP variants revealed a nonsense mutation (R317X) in the eleventh exon leading to a premature termination of the PAX6 protein in the proline-serine-threonine (PST)-rich domain in two probands. Another proband exhibited an intronic polymorphism (IVS 9–12 C-T). The mutation resulted in loss of function of the PAX6 protein along with variable phenotypic manifestations in the probands. This is the first report describing a PAX6 gene mutation in aniridia cases from India and highlights the variable expressivity in phenotypes due to haploinsufficiency.     

Pseudopapilledema in neurofibromatosis type 2

PURPOSE: To report a case of neurofibromatosis type 2 with pseudopapilledema secondary to a prepapillary gliotic membrane. METHOD: Case report. Results of an ocular examination and fluorescein angiography of a patient are described. RESULTS: Fundus examination of a 14-year-old male with neurofibromatosis type 2 revealed an irregular elevation of the optic nerve and a perifoveal epiretinal membrane in the right eye. Fluorescein angiography demonstrated no autofluorescence nor leakage in the area of the optic nerve. CONCLUSION: The patient has pseudopapilledema secondary to an epiretinal membrane overlying the optic disk of the right eye. The possibility of pseudopapilledema should be considered when evaluating patients with neurofibromatosis type 2 and abnormal optic nerves.     

A Novel Mutation in Helical Domain 2 of NOD2 in Sporadic Blau Syndrome

We report a 12-year-old girl who presented with bilateral granulomatous anterior uveitis accompanied by boggy arthritis of knee and ankle joints, intermittent fever, and nodular skin rash. She was diagnosed with sporadic Blau syndrome (early-onset sarcoidosis) based on above clinical signs and presence of non-necrotising granuloma on iris biopsy. DNA sequencing revealed a previously unreported heterozygous mutation consisting of a G>A transition in exon 4 of the NOD2 gene. This resulted in a glutamic acid to lysine substitution in helical domain 2 of the nucleotide binding and oligomerization (NACHT) region, possibly reducing efficiency of auto-inhibition in NOD2 signaling. Interestingly, the ocular inflammation resolved completely following therapeutic vitrectomy in both eyes whereas the systemic symptoms of fever and arthritis continued to wax and wane while on treatment with oral methotrexate and corticosteroids.     

Cox-2 expression in retinoblastoma

PURPOSE: Cox-2, a prostaglandin synthase, is overexpressed in colorectal cancers and is involved in angiogenesis as well as in tumorigenesis. In this study, we investigate the expression of Cox-2 in retinoblastoma. METHODS: Twenty-nine formalin-fixed retinoblastoma specimens were examined by the labeled-streptavidin-biotin method using anti-Cox-2 antibody. RESULTS: Cox-2 positive immunoreactions were observed in 28 (96%) of 29 retinoblastomas specimens. CONCLUSION: This preliminary study suggests the overexpression of Cox-2 in both differentiated and undifferentiated retinoblastoma and its possible role in tumorigenesis.     

Changes in scleral MMP-2, TIMP-2 and TGFbeta-2 mRNA expression after imposed myopic and hyperopic defocus in chickens

Induction of myopia leads to a decreased glycosaminoglycan synthesis and smaller collagen fibrillar diameters, increased levels of gelatinase-A (MMP-2) and decreased amounts of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the fibrous sclera of both chicks and tree shrews. Another factor found to be involved in altered eye growth is the transforming growth factor beta-2 (TGFbeta-2). The aim of the current study was to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA expression changes separately in the two scleral layers of chicks, following myopic and hyperopic defocus. Chicks were treated unilaterally with positive and negative lenses for different time periods. All contralateral eyes wore plano lenses and additional controls, treated binocularly with plano lenses, were included. Real-time PCR was used to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA levels. Few changes in MMP-2 and TIMP-2 mRNA levels were measured following treatment with plus and minus lenses for up to 3 days. The mRNA levels of MMP-2 and TIMP-2 were either unchanged or co-regulated in both eyes, even though only the eye with the powered lens actually displayed changes in growth. In contrast, TGFbeta-2 mRNA was significantly up-regulated in the cartilaginous layer following treatment with plus lenses after 24 hr, compared to all other groups. These changes were confined to the eyes that also displayed reduced growth, suggesting a role of TGFbeta-2 in the final steps of visual eye growth regulation.     

Expression of P2Y1, P2Y2, P2Y4, and P2Y6 receptor subtypes in the rat retina

PURPOSE: To elucidate the expression pattern of different types of metabotropic P2Y receptors in the adult rat retina. METHODS: Qualitative RT-PCR was used to investigate the expression profile of different P2Y receptor subtypes (P2Y1, P2Y2, P2Y4, and P2Y6), and in situ hybridization studies were performed to show their cellular localization within the retina. Immunohistochemical staining was used to detect the corresponding P2Y proteins (P2Y1, P2Y2, and P2Y4) and their cellular localization. Southern blot analysis and sequencing verified the identity of the P2Y PCR products. RESULTS: RT-PCR revealed the presence of P2Y1, -2, -4, and -6 mRNA in the neural retina and the retinal pigment epithelium (RPE) and choroid. In situ hybridization showed labeling in the retinal ganglion cell layer for all four P2Y receptor subtypes, although the intensity varied. In addition, staining for P2Y1, -4, and -6 mRNA was shown in the inner nuclear layer, but was absent for the P2Y2 receptor subtype. Immunohistochemistry showed intense staining for P2Y1, -2, and -4 in the ganglion cell layer and the outer plexiform layer. There was also a specific subtype staining in the inner plexiform layer (P2Y2, -4), the inner (P2Y1, -4) and outer (P2Y1) nuclear layers and the inner segments of the photoreceptors (P2Y1, -2). discussion. The data suggest that extracellular nucleotides may play complex roles as autocrine-paracrine mediators and may have neuromodulatory effects in the retina through metabotropic P2Y receptors.