Skip to main content
Log in

Mertk deficiency alters expression of micrornas in the retinal pigment epithelium cells

  • Research Article
  • Published:
Metabolic Brain Disease Aims and scope Submit manuscript

Abstract

Phagocytic clearance of the spent photoreceptor outer segments (OS) by RPE cells is regulated by circadian rhythm cycle and is essential for photoreceptor integrity and function. Mertk regulates RPE phagocytosis and a deficiency in Mertk causes photoreceptor degeneration and visual loss. This study aimed to investigate Mertk regulation of the microRNAs (miRNA), potentially regulating expression of their target genes, which affect phagocytosis. The differentially expressed miRNAs were identified using miRCURYTM microRNA Arrays from total RNA isolated at 0900 h and 1900 h from the mechanically dissociated RPE sheets of the WT and Mertk −/− mice, which were housed in a 12-h light-dark cycle with the lighting onset at 0700 h (7:00am). Validation of the differentially expressed miRNAs and assessment of the putative miRNA target gene expression were performed by real-time PCR. Among the differentially expressed miRNAs in the Mertk −/− RPE, seven miRNAs were up-regulated and 13 were down-regulated in the morning groups. Similarly, 24 miRNAs were found to be up-regulated and 13 were down-regulated in the evening groups. To search for those that may participate in regulating expression of cytoskeletal proteins, we examined the predicted target genes that might participate in phagocytosis were examined by real-time PCR. Of nine potential altered targets, four deregulated genes were myosin subunits. Notably, multiple members of the 21 up-regulated miRNAs can theoretically recognize these down-regulated mRNAs, particularly MyH14 and Myl3. This study shows that loss of Mertk alters miRNA expression, which in turn affects expression of the downstream target genes, potentially affecting phagocytosis.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  • Bartel DP (2004) MicroRNAs: genomics, biogenesis, mechanism, and function. Cell 116:281–297

    Article  CAS  PubMed  Google Scholar 

  • Bok D, Hall MO (1971) The role of the pigment epithelium in the etiology of inherited retinal dystrophy in the rat. J Cell Biol 49:664–682

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • D'Cruz PM, Yasumura D, Weir J, Matthes MT, Abderrahim H et al (2000) Mutation of the receptor tyrosine kinase gene Mertk in the retinal dystrophic RCS rat. Hum Mol Genet 9:645–651

    Article  PubMed  Google Scholar 

  • Duncan JL, LaVail MM, Yasumura D, Matthes MT, Yang H et al (2003) An RCS-like retinal dystrophy phenotype in mer knockout mice. Invest Ophthalmol Vis Sci 44:826–838

    Article  PubMed  Google Scholar 

  • Edwards RB, Szamier RB (1977) Defective phagocytosis of isolated rod outer segments by RCS rat retinal pigment epithelium in culture. Science 197:1001–1003

    Article  CAS  PubMed  Google Scholar 

  • Gal A, Li Y, Thompson DA, Weir J, Orth U et al (2000) Mutations in MERTK, the human orthologue of the RCS rat retinal dystrophy gene, cause retinitis pigmentosa. Nat Genet 26:270–271

    Article  CAS  PubMed  Google Scholar 

  • Gibbs D, Kitamoto J, Williams DS (2003) Abnormal phagocytosis by retinal pigmented epithelium that lacks myosin VIIa, the Usher syndrome 1B protein. Proc Natl Acad Sci U S A 100:6481–6486

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • He L, Hannon GJ (2004) MicroRNAs: small RNAs with a big role in gene regulation. Nat Rev Genet 5:522–531

    Article  CAS  PubMed  Google Scholar 

  • Huang KM, Dentchev T, Stambolian D (2008) MiRNA expression in the eye. Mamm Genome 19:510–516

    Article  CAS  PubMed  Google Scholar 

  • Karali M, Peluso I, Marigo V, Banfi S (2007) Identification and characterization of microRNAs expressed in the mouse eye. Invest Ophthalmol Vis Sci 48:509–515

    Article  PubMed  Google Scholar 

  • LaVail MM (1973) Kinetics of rod outer segment renewal in the developing mouse retina. J Cell Biol 58:650–661

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • LaVail MM (1976) Rod outer segment disk shedding in rat retina: relationship to cyclic lighting. Science 194:1071–1074

    Article  CAS  PubMed  Google Scholar 

  • LaVail MM (1980) Circadian nature of rod outer segment disc shedding in the rat. Invest Ophthalmol Vis Sci 19:407–411

    CAS  PubMed  Google Scholar 

  • Loscher CJ, Hokamp K, Kenna PF, Ivens AC, Humphries P et al (2007) Altered retinal microRNA expression profile in a mouse model of retinitis pigmentosa. Genome Biol 8:R248

    Article  PubMed Central  PubMed  Google Scholar 

  • Lu Q, Gore M, Zhang Q, Camenisch T, Boast S et al (1999) Tyro-3 family receptors are essential regulators of mammalian spermatogenesis. Nature 398:723–728

    Article  CAS  PubMed  Google Scholar 

  • Lu H, Lu Q, Gaddipati S, Kasetti RB, Wang W et al (2014) IKK2 inhibition attenuates laser-induced choroidal neovascularization. PLoS One 9:e87530

    Article  PubMed Central  PubMed  Google Scholar 

  • McHenry CL, Liu Y, Feng W, Nair AR, Feathers KL et al (2004) MERTK arginine-844-cysteine in a patient with severe rod-cone dystrophy: loss of mutant protein function in transfected cells. Invest Ophthalmol Vis Sci 45:1456–1463

    Article  PubMed  Google Scholar 

  • Nandrot EF, Finnemann SC (2006) Altered rhythm of photoreceptor outer segment phagocytosis in beta5 integrin knockout mice. Adv Exp Med Biol 572:119–123

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Nandrot E, Dufour EM, Provost AC, Pequignot MO, Bonnel S et al (2000) Homozygous deletion in the coding sequence of the c-mer gene in RCS rats unravels general mechanisms of physiological cell adhesion and apoptosis. Neurobiol Dis 7:586–599

    Article  CAS  PubMed  Google Scholar 

  • Nandrot EF, Kim Y, Brodie SE, Huang X, Sheppard D et al (2004) Loss of synchronized retinal phagocytosis and age-related blindness in mice lacking alphavbeta5 integrin. J Exp Med 200:1539–1545

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Nandrot EF, Anand M, Sircar M, Finnemann SC (2006) Novel role for alphavbeta5-integrin in retinal adhesion and its diurnal peak. Am J Physiol Cell Physiol 290:C1256–C1262

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Pegoraro M, Tauber E (2008) The role of microRNAs (miRNA) in circadian rhythmicity. J Genet 87:505–511

    Article  CAS  PubMed  Google Scholar 

  • Prasad D, Rothlin CV, Burrola P, Burstyn-Cohen T, Lu Q et al (2006) TAM receptor function in the retinal pigment epithelium. Mol Cell Neurosci 33:96–108

    Article  CAS  PubMed  Google Scholar 

  • Robosky LC, Wade K, Woolson D, Baker JD, Manning ML et al (2008) Quantitative evaluation of sebum lipid components with nuclear magnetic resonance. J Lipid Res 49:686–692

    Article  CAS  PubMed  Google Scholar 

  • Ryan DG, Oliveira-Fernandes M, Lavker RM (2006) MicroRNAs of the mammalian eye display distinct and overlapping tissue specificity. Mol Vis 12:1175–1184

    CAS  PubMed  Google Scholar 

  • Smith RJ, Berlin CI, Hejtmancik JF, Keats BJ, Kimberling WJ et al (1994) Clinical diagnosis of the Usher syndromes. Usher Syndrome Consortium. Am J Med Genet 50:32–38

    Article  CAS  PubMed  Google Scholar 

  • Strick DJ, Feng W, Vollrath D (2009) Mertk drives myosin II redistribution during retinal pigment epithelial phagocytosis. Invest Ophthalmol Vis Sci 50:2427–2435

    Article  PubMed  Google Scholar 

  • Thompson DA, McHenry CL, Li Y, Richards JE, Othman MI et al (2002) Retinal dystrophy due to paternal isodisomy for chromosome 1 or chromosome 2, with homoallelism for mutations in RPE65 or MERTK, respectively. Am J Hum Genet 70:224–229

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Tschernutter M, Jenkins SA, Waseem NH, Saihan Z, Holder GE et al (2006) Clinical characterisation of a family with retinal dystrophy caused by mutation in the Mertk gene. Br J Ophthalmol 90:718–723

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Vicente-Manzanares M, Ma X, Adelstein RS, Horwitz AR (2009) Non-muscle myosin II takes centre stage in cell adhesion and migration. Nat Rev Mol Cell Biol 10:778–790

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Weil D, Blanchard S, Kaplan J, Guilford P, Gibson F et al (1995) Defective myosin VIIA gene responsible for Usher syndrome type 1B. Nature 374:60–61

    Article  CAS  PubMed  Google Scholar 

  • Xin Y, Lu Q, Li Q (2010) 14-3-3sigma controls corneal epithelial cell proliferation and differentiation through the Notch signaling pathway. Biochem Biophys Res Commun 392:593–598

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Xu S, Witmer PD, Lumayag S, Kovacs B, Valle D (2007) MicroRNA (miRNA) transcriptome of mouse retina and identification of a sensory organ-specific miRNA cluster. J Biol Chem 282:25053–25066

    Article  CAS  PubMed  Google Scholar 

  • Young RW (1967) The renewal of photoreceptor cell outer segments. J Cell Biol 33:61–72

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  • Young RW, Bok D (1969) Participation of the retinal pigment epithelium in the rod outer segment renewal process. J Cell Biol 42:392–403

    Article  CAS  PubMed Central  PubMed  Google Scholar 

Download references

Acknowledgments

This paper was supported by NIH grants R01EY018830 and Research to Prevent Blindness.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Qingxian Lu.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tang, Y., Lu, Q., Wei, Y. et al. Mertk deficiency alters expression of micrornas in the retinal pigment epithelium cells. Metab Brain Dis 30, 943–950 (2015). https://doi.org/10.1007/s11011-015-9653-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11011-015-9653-5

Keywords

Navigation