Ryan David G, Oliveira-Fernandes Michelle, Lavker Robert M
Department of Dermatology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Mol Vis. 2006 Oct 17;12:1175-84.
In mammals, endogenous, noncoding RNAs, designated as microRNAs (miRNAs), inhibit the translation of a target messenger RNA, thereby silencing protein production. MiRNAs have been shown to regulate many aspects of development and differentiation in a wide range of tissues. Surprisingly, little consideration has been directed towards characterizing the expression of miRNAs in mammalian ocular tissues.
Low molecular weight (LMW) RNA isolated from the adult mouse corneal epithelium, lens/ciliary body, and a retina fractions of the eye was analyzed by miRNA arrays. The validity of the miRNA expression profiles were confirmed by northern blots and the tissue distribution of selected miRNAs was determined by in situ hybridization.
MiRNAs exhibited distinct tissue and cell-type specificity in the ocular regions studied. MiRNA (mir)-184 had the highest hybridization signal in the corneal and lens arrays. In situ hybridization analysis revealed that mir-184 was expressed in the basal and immediately suprabasal cells of the corneal epithelium. In contrast, expression of mir-205 was detected throughout the anterior segmental epithelia as well as in the epidermis. Within the lens, expression of mir-184 was more strongly expressed in the epithelial cells of the germinative zone, whereas expression of mir-204 was uniformly expressed in all lens epithelial cells. Mir-181, -182, and -183 were detected in retinal and brain tissues, and their distribution patterns within the retina were both distinct and overlapping.
The tissue and cell specificity of ocular miRNAs suggests that these noncoding RNAs may be regulating aspects of development and differentiation.
在哺乳动物中，内源性非编码RNA，即微RNA（miRNA），可抑制靶信使RNA的翻译，从而使蛋白质合成沉默。已证明miRNA可调节多种组织发育和分化的许多方面。令人惊讶的是，很少有人关注哺乳动物眼组织中miRNA表达的特征。
通过miRNA阵列分析从成年小鼠角膜上皮、晶状体/睫状体和眼视网膜部分分离的低分子量（LMW）RNA。通过Northern印迹证实miRNA表达谱的有效性，并通过原位杂交确定所选miRNA的组织分布。
在研究的眼区中，miRNA表现出明显的组织和细胞类型特异性。miRNA（mir）-184在角膜和晶状体阵列中具有最高的杂交信号。原位杂交分析显示，mir-184在角膜上皮的基底细胞和紧邻基底上方的细胞中表达。相比之下，在整个前段上皮以及表皮中均检测到mir-205的表达。在晶状体中，mir-184在生发区的上皮细胞中表达更强，而mir-204在所有晶状体上皮细胞中均有均匀表达。在视网膜和脑组织中检测到mir-181、-182和-183，它们在视网膜内的分布模式既不同又有重叠。
眼miRNA的组织和细胞特异性表明这些非编码RNA可能在调节发育和分化方面发挥作用。
