miR-135A Regulates Preimplantation Embryo Development through Down-Regulation of E3 Ubiquitin Ligase Seven in Absentia Homolog 1A (SIAH1A) Expression

Abstract

BackgroundMicroRNAs (miRNAs) are small non-coding RNA molecules capable of regulating transcription and translation. Previously, a cluster of miRNAs that are specifically expressed in mouse zygotes but not in oocytes or other preimplantation stages embryos are identified by multiplex real-time polymerase chain reaction-based miRNA profiling. The functional role of one of these zygote-specific miRNAs, miR-135a, in preimplantation embryo development was investigated.Methodology/Principal FindingsMicroinjection of miR-135a inhibitor suppressed first cell cleavage in more than 30% of the zygotes. Bioinformatics analysis identified E3 Ubiquitin Ligase Seven In Absentia Homolog 1A (Siah1a) as a predicted target of miR-135a. Western blotting and 3′UTR luciferase functional assays demonstrated that miR-135a down-regulated the expression of Siah1 in HeLa cells and in mouse zygotes. Siah1a was expressed in preimplantation embryos and its expression pattern negatively correlated with that of miR-135a. Co-injection of Siah1a-specific antibody with miR-135a inhibitor partially nullified the effect of miR-135a inhibition. Proteasome inhibition by MG-132 revealed that miR-135a regulated proteasomal degradation and potentially controlled the expression of chemokinesin DNA binding protein (Kid).Conclusions/SignificanceThe present study demonstrated for the first time that zygotic specific miRNA modulates the first cell cleavage through regulating expression of Siah1a.

Epigenetic Risk Factors for Diseases: A Transgenerational Perspective

“…The role of sperm-delivered miRNAs in the oocyte remains unclear because endogenous miRNAs have been shown to only poorly repress target mRNAs in the oocyte (Ma et al 2010 ). However, some studies have found that individual sperm-borne miRNAs, miR-135a and miR-34c, regulate key genes in the zygote and are crucial for normal embryo development (Pang et al 2011 ;Liu et al 2012 ). In addition, piRNAs are known to play a role in germ cell development, especially in the silencing of transposons by guiding DNAme (Aravin et al 2008 ;Law and Jacobsen 2010 ).…”

Neurobiological disease etiology and inheritance: an epigenetic perspective

“…As some miRNAs are stable, with a half-life of over 24 h (Winter and Diederichs, 2011), which is within the maturation time of a fertilized oocyte, it is conceivable that paternally derived miRNAs regulate translation immediately upon fertilization or at later stages of embryonic development. Accordingly, individual sperm-borne miRNAs, miR-135a and miR34c, have recently been shown to regulate key genes in the mouse zygote essential for normal embryonic development (Liu et al, 2012;Pang et al, 2011). Specifically, inhibition of miR-135a via microinjection of a synthetic antagomir reduced the percentage of zygotes developing to the two-cell stage (Pang et al, 2011).…”

“…Accordingly, individual sperm-borne miRNAs, miR-135a and miR34c, have recently been shown to regulate key genes in the mouse zygote essential for normal embryonic development (Liu et al, 2012;Pang et al, 2011). Specifically, inhibition of miR-135a via microinjection of a synthetic antagomir reduced the percentage of zygotes developing to the two-cell stage (Pang et al, 2011). This effect could be almost completely rescued by co-injection of an antibody against Siah1, a ubiquination/proteasome pathway protein, which is a direct target of miR-135a.…”

MIR135A1 (microRNA 135a-1)

“…When miR135a is inhibited, first cell cleavage is suppressed. mir-135a regulates proteosomal degradation (Pang et al, 2011).…”