Abstract
The somatotropic axis, composed essentially of the growth hormone (GH) and insulin-like growth factors (IGFs), is the main regulator of somatic growth in vertebrates. However, these protein hormones are also involved in various other major physiological processes. Although the importance of IGFs in mechanisms involving tissue regeneration has already been established, little is known regarding the direct effects of GH in these processes. In this study, we used a transgenic zebrafish (Danio rerio) model, which overexpresses GH from the beta-actin constitutive promoter. The regenerative ability of the caudal fin was assessed after repeated amputations, as well as the expression of genes related to the GH/IGF axis. The results revealed that GH overexpression increased the regenerated area of the caudal fin in transgenic fish after the second amputation. Transgenic fish also presented a decrease in gene expression of the GH receptor (ghrb), in opposition to the increased expression of the IGF1 receptors (igf1ra and igf1rb). These results suggest that transgenic fish have a higher sensitivity to IGFs than to GH during fin regeneration. With respect to the different IGFs produced locally, a decrease in igf1a expression and a significant increase in both igf2a and igf2b expression was observed, suggesting that igf1a is not directly involved in fin regeneration. Overall, the results revealed that excess GH enhances fin regeneration in zebrafish through igf2a and igf2b expression, acting indirectly on this major physiological process.
References
Annunziata M, Granata R, Ghigo E (2011) The IGF system. Acta Diabetol 48:1–9. doi:10.1007/s00592-010-0227-z
Azevedo AS, Grotek B, Jacinto A, Weidinger G, Saúde L (2011) The regenerative capacity of the zebrafish caudal fin is not affected by repeated amputations. PLoS ONE 6:1–8. doi:10.1371/journal.pone.0022820
Chablais F, Jazwinska A (2010) IGF signaling between blastema and wound epidermis is required for fin regeneration. Development 137:871–879. doi:10.1242/dev.043885
Dai XY, Zhang W, Zhuo ZJ, He JY, Yin Z (2015) Neuroendocrine regulation of somatic growth in fishes. Sci China Life Sci 58:137–147. doi:10.1007/s11427-015-4805-8
Figueiredo MA, Lanes CFC, Almeida DV, Marins LF (2007a) Improving the production of transgenic fish germlines: in vivo evaluation of mosaicism in zebrafish (Danio rerio) using flourescent protein (GFP) and growth hormone cDNA transgene co-injection strategy. Genet Mol Biol 30:31–36. doi:10.1590/S1415-47572007000100008
Figueiredo MA, Lanes CFC, Almeida DV, Proietti MC, Marins LF (2007b) The effect of GH overexpression on GHR and IGF-I gene regulation in different genotypes of GH-transgenic zebrafish. Comp Biochem Physiol Part D Genom Proteom 2:228–233. doi:10.1016/j.cbd.2007.04.004
Fuentes EN, Valdés JA, Molina A, Björnsson BT (2013) Regulation of skeletal muscle growth in fish by the growth hormone-insulin-like growth factor system. Gen Comp Endocrinol 192:136–148. doi:10.1016/j.ygcen.2013.06.009
Gemberling M, Bailey TJ, Hyde DR, Poss KD (2013) The zebrafish as a model for complex tissue regeneration. Trends Genet 29:611–620. doi:10.1016/j.tig.2013.07.003
Huang Y, Harrison MR, Osorio A, Kim J, Baugh A, Duan C, Sucov HM, Lien CL (2013) IGF signaling is required for cardiomyocyte proliferation during zebrafish heart development and regeneration. PLoS ONE 8:628–633. doi:10.1371/journal.pone.0067266
Iovine M (2007) Conserved mechanisms regulate outgrowth in zebrafish fins. Nat Chem Biol 3:613–618. doi:10.1038/nchembio.2007.36
Lanning NJ, Carter-Su C (2006) Recent advances in growth hormone signaling. Rev Endocr Metab Disord 7:225–235. doi:10.1007/s11154-007-9025-5
Nornberg BF, Figueiredo MA, Marins LF (2016) Expression profile of IGF paralog genes in liver and muscle of a GH-transgenic zebrafish. Gen Comp Endocrinol 226:36–41. doi:10.1016/j.ygcen.2015.12.017
Pennisi PA, Kopchick JJ, Thorgeirsson S, LeRoith D, Yakar S (2004) Role of growth hormone (GH) in liver regeneration. Endocrinol 145:4748–4755. doi:10.1210/en.2004-0655
Poss KD (2010) Advances in understanding tissue regenerative capacity and mechanisms in animals. Nat Rev Genet 11:710–722. doi:10.1006/dbio.2000.9722
Ren H, Yin P, Duan C (2008) IGFBP-5 regulates muscle cell differentiation by binding to IGF-II and switching on the IGF-II auto-regulation loop. J Cell Biol 182:979–991. doi:10.1083/jcb.200712110
Reznick AZ, Carmeli E, Roisman I (1996) Effects of growth hormone on skeletal muscles of aging systems. Age 19:39–44. doi:10.1007/BF02434069
Schuck JB, Sun H, Penberthy WT, Cooper NG, Li X, Smith ME (2011) Transcriptomic analysis of the zebrafish inner ear points to growth hormone mediated regeneration following acoustic trauma. BMC Neurosci 12:88. doi:10.1186/1471-2202-12-88
Singh SP, Holdway JE, Poss KD (2012) Regeneration of amputated zebrafish fin rays from de novo osteoblasts. Dev Cell 22:879–886. doi:10.1016/j.devcel.2012.03.006
Sun H, Lin CH, Smith ME (2011) Growth Hormone promotes hair cell regeneration in the zebrafish (Danio rerio) inner ear following acoustic trauma. PLoS ONE 6:e28372. doi:10.1371/journal.pone.0028372
Tryon RC, Johnson SL (2014) Clonal analysis of kit ligand a functional expression reveals lineage-specific competence to promote melanocyte rescue in the mutant regenerating caudal fin. PLoS ONE 9:1–9. doi:10.1371/journal.pone.0102317
Vandesompele J, De Preter K, Poppe B, Van Roy N, De Paepe A, Speleman F (2002) Accurate normalization of real-time quantitative RT-PCR data by geometric averaging of multiple internal control genes. Genome Biol 3:1–12
Varga M, Sass M, Papp D, Takács-Vellai K, Kobolak J, Dinnyés A Klionsky DJ, Vellai T (2014) Autophagy is required for zebrafish caudal fin regeneration. Cell Death Differ 21:547–556. doi:10.1038/cdd.2013.175
Wehner D, Weidinger G (2015) Signaling networks organizing regenerative growth of the zebrafish fin. Trends Genet 31:336–343. doi:10.1016/j.tig.2015.03.012
Westerfield M (1995) The zebrafish book: a guide for the laboratory use of zebrafish (Danio rerio), 2nd edn. University of Oregon Press, Eugene
Wood AW, Duan C, Bern H (2005) Insulin-like growth factor signaling in fish. Int Rev Cytol 243:215–285. doi:10.1016/S0074-7696(05)43004-1
Zou S, Kamei H, Modi Z, Duan C (2009) Zebrafish IGF genes: gene duplication, conservation and divergence, and novel roles in midline and notochord development. PLoS ONE 4:e7026. doi:10.1371/journal.pone.0007026
Acknowledgments
This work was financially supported by Brazilian CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Proc. No. 453966/2014-4). Luis Fernando Marins is a research fellow from CNPq (Proc. No. 305928/2015-5).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nornberg, B.F., Almeida, D.V., Figueiredo, M.A. et al. GH indirectly enhances the regeneration of transgenic zebrafish fins through IGF2a and IGF2b. Transgenic Res 25, 743–749 (2016). https://doi.org/10.1007/s11248-016-9957-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11248-016-9957-1