MicroRNA miR-466 inhibits Lymphangiogenesis by targeting prospero-related homeobox 1 in the alkali burn corneal injury model

Abstract

BackgroundLymphangiogenesis is one of the major causes of corneal graft rejection. Among the lymphangiogenic factors, vascular endothelial growth factor (VEGF)-C and -D are considered to be the most potent. Both bind to VEGF receptor 3 (VEGFR3) to activate Prospero homeobox 1 (Prox1), a transcription factor essential for the development and maintenance of lymphatic vasculature. MicroRNAs (miRNAs) bind to the 3' untranslated regions (3' UTRs) of target genes in a sequence-specific manner and suppress gene expression. In the current study, we searched for miRNAs that target the pro-lymphangiogenic factor Prox1.ResultsAmong the miRNAs predicted by the bioinformatic analysis to seed match with the 3' UTR of Prox-1, we chose 3 (miR-466, miR-4305, and miR-4795-5p) for further investigation. Both the miR-466 and miR-4305 mimics, but not the miR-4795-5p mimic, significantly reduced the luciferase activity of the Prox-1 3' UTR reporter vector. In primary lymphatic endothelial cells (HDLEC), miR-466 mimic transfection suppressed Prox1 mRNA and protein expression, while miR-4305 mimic transfection did not. Experiments using mutated reporter constructs of the two possible seed match sites on the 3' UTR of Prox1 suggested that the target site 2 directly bound miR-466. HDLEC transfected with the miR-466 mimic suppressed tube formation as compared to the scrambled control. Furthermore, HDLEC transfected with a miR-466 inhibitor showed enhanced tube formation as compared to control inhibitor transfected cells, and this inhibitory effect was counteracted by Prox1 siRNA. The miR-466 mimic reduced angiogenesis and lymphangiogenesis resulting in clearer corneas in an cornea injury rat model compared to the scrambled control.ConclusionsOur data suggest that miR-446 may have a protective effect on transplanted corneas by suppressing Prox1 expression at the post-transcriptional level. The results of the current study may provide insights into the mechanisms of lymphangiogenesis resulting from corneal graft rejection and alkali-burn injuries, as well as into the development of new treatments for lymphangiogenic eye diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12929-014-0104-0) contains supplementary material, which is available to authorized users.

MicroRNA-126a Directs Lymphangiogenesis Through Interacting With Chemokine and Flt4 Signaling in Zebrafish

“…Because miR-126 KO mouse embryos show systemic edema at E15.5, 25 the function of miR-126 in lymphangiogenesis might be conserved in mice. Although several miRNAs are involved in lymphangiogenesis, [19][20][21][22][23] our work reported here illuminates the guidance role of miRNA in lymphangiogenesis in vivo.…”

“…17,18 Recently, several miRNAs have been reported to play important functions in lymphangiogenesis. [19][20][21][22][23] MiR-31, miR-181, and miR-466 function as negative regulators of LEC differentiation by directly binding to PROX1 3′ untranslated region (UTR). [20][21][22] In addition, miR-1236 represses the inflammatory lymphangiogenesis by targeting Vegfr3.…”

“…[19][20][21][22][23] MiR-31, miR-181, and miR-466 function as negative regulators of LEC differentiation by directly binding to PROX1 3′ untranslated region (UTR). [20][21][22] In addition, miR-1236 represses the inflammatory lymphangiogenesis by targeting Vegfr3. 19 These findings point to the important function of miRNAs in LVs formation; however, the miRNA functioning as a director of LEC migration and lymphatic assembly is still unidentified.…”

The function of homeobox genes and lncRNAs in cancer

“…Well-studied miRNAs, including miR-196a/b, miR-10a/b and lncRNAs (such as HOTAIR, HOTAIRM1 and HOXA11-AS), were observed to dysregulate gene expression and were associated with tumor development (24,32,36). miR-464, miR-10 and miR-414 are located in the tammar HOX clusters and were identified to have an effect on these, for example inhibiting lymphangiogenesis (miR-414) and promoting active tumor cell invasion (miR-10) (102,103). In addition, certain novel miRNAs are transcribed from elsewhere on the tammar genome and regulate the expressions of HOXB and HOXD clusters by specifically interacting with the mRNAs transcribed from them (104).…”

Features of mir-466-3p binding sites in mRNA genes with different functions

“…The type of disease will depends on the ratio of the concentrations of miR-466-3p and target mRNAs of target genes in specific cells and tissues of the body [12][13][14][15][16][17][18].…”