Metabolic Regulation of Insulin-like Growth Factor-1 Expression

쥐의 insulin-like growth tractor리 유전자 발현의 대사조절기전에 관안 연구

  • 안미라 (전남대학교 수의과대학 수의학과 및 생물공학연구소)
  • Published : 2002.06.01

Abstract

The present study was aimed at investigating the metabolic regulation of insulin-like growth factor-I(IGF-I) expression in fasting animals. The expression of IGF-I gene was determined by a solution hybridization/RNase protection assay using total RNA from control, 4d-fasting, and 2d-fasting-refed rats. The levels of IGF-I transcripts were reduced in 4d-fasting than in control by decreasing its transcriptional rate, which was measured through nuclear nun-on assay. DNase I footprinting, which was performed using nuclear extracts from fasting rat, demonstrated protein binding to a sequence that extended from +179 to +210 (termed region B). These data suggest that the expression of IGF-I is transcriptionally regulated through DNA-liver enriched protein binding in a sequence which is located downstream from major transcription initiation site of IGF-I gene.

Insulin-like growth factor-I(IGF-I)은 성장호르몬의 여러 가지 성정촉진 작용을 매개하는 분열 유발성 폴리펩티드이며, 조직의 수선과 재생, 창상치유 및 골대사와 같은 과정들에서 중요한 역할을 하는 것으로 알려져 있고, 비교적 여러 조직에서 발현되고 있는 IGF-I 유전자의 전사조절에 대한 정확한 분자적 기전과 호르몬 및 대사 상태가 그것을 어떻게 조절하는지 아직 밝혀져 있지 않다. 쥐를 절삭시키므로써 대사 상태를 변조시켰을 때, 간 조직내 IGF-I mRNA의 발현에 미치는 절식의 영향을 살펴보기 위하여 solution hybridizatioon/RNase protection 방법으로 분석 하였다. IGF-I의 exon 1 및 exon 2에 의하여 encode된 tran-scripts 모두가 감소된 결과를 얻었고, 이러한 감소는 전사 수준에서 일어난 것으로 nuclear run-on 분석에 의하여 확인하였다. 또한 절식시킨 쥐에서 IGF-I mRNA의 양을 조절하는 cia-acting elements를 IGF-I 유전자의 5'-flanking 지역과 exon 1과 econ 2에서 밝히고자 절식시킨 쥐의 신선한 간조직에서 핵 추출물을 얻어 IGF-I의 여러 가지 DNA fragments와 반응시켜 DNase I protection 분석을 한 결과, IGF-I 유전자의 주요한 전사 개 시점으로부터 downstream에 있는 sequences가 절식으로 변조시킨 대사상태에서 IGF-I의 발현 조절에 중요하며 이곳에는 전사인자인 C/EBP family의 isoform들을 포함한 간조직에 풍부하게 존재하는 여러 전사인자들이 결합할 것으로 제안하였다.

Keywords

References

  1. Rotwein, P. (1991), Structure, evolution, expression and regulation of insulin-like growth factors I and II, Growth Factors, 5, 3-18 https://doi.org/10.3109/08977199109000267
  2. Pao, C. I., J-I. Zhu, D. G. Robertson, K-w. M. Lin, P. K. Farmer, S. Begovic, G-j. Wu, and L. S. Phillips (1995), Transcriptional regulation of the rat insulin-like growth factor-I gene involves metabolism-dependent binding of nuclear proteins to a down stream region, J. BioI. Chern. 270, 24917-24923 https://doi.org/10.1074/jbc.270.42.24917
  3. Lowe., W. L. (1991) In: Insulin-Like Growth Factors: Molecular and Cellular Aspects (LeRoith, D., ed.), pp. 49-85, CRC press, Boca Raton
  4. Cohick, W. S. and D. R. Clemmons (1993), The insulinlike growth factors, Annu. Rev. Physiol. 55, 131-153 https://doi.org/10.1146/annurev.ph.55.030193.001023
  5. Lamothe, B., A. Baudry, P. Desbois, L. Lamotte, D. Bucchini, P. De Meyts, and R. L. Joshe (1998), Genetic engineering in mice : impact on insulin signalling and action, Biochem. J. 335, 193-204 https://doi.org/10.1042/bj3350193
  6. Dor, S., S. Kar, and R. Quirion (1997), Rediscovering an old friend, IGF-I: potential used in the treatment of neurodegenerative diseases, Trends Neurosci. 20, 326-331 https://doi.org/10.1016/S0166-2236(96)01036-3
  7. Mittanck, D. W., S. W. Kim, and P. Rotwein (1997), Essential promoter elements are located within the 5' untranslated region of human insulin-like growth factor-I exon I, J. Mol. Cell. Endocrinol. 126, 153-163 https://doi.org/10.1016/S0303-7207(96)03979-2
  8. Thissen, J. P., J. M. Ketelslegers, and L. E. Underwood (1994), Nutritional regulation of the insulin-like growth factors, Endocrine Rev. 15, 80-101 https://doi.org/10.1210/edrv-15-1-80
  9. Lowe, W. L., M. L. Adamo, H. Werner, C. T. Roberts Jr.. and D. LeRoith (1989), Regulation by fasting of rat insulin-like growth factor I and its receptor : effects on gene expression and binding, J. Clin. Invest. 84, 619-626 https://doi.org/10.1172/JCI114207
  10. Hayden, J. M., N. W. Marten, E. J. Burke, and D. S. Straus (1994), The effect of fasting on insulin-like growth factor-I nuclear transcript abundance in rat liver, Endoerinol. 134, 760-768 https://doi.org/10.1210/en.134.2.760
  11. An, M. R., C-C. Hsieh, P. D. Reisner, J. P. Rabek, S. G. Scott, D. T. Kuninger, and J. Papaconstantinou (1996), Evidence for posttranscriptional regulation of C/EBP $\alpha$ and C/EBP $\beta$ isoform expression during the lipopolysaccharidemediated acute-phase response, Mol. Cell. BioI. 16, 2295-2306 https://doi.org/10.1128/MCB.16.5.2295
  12. Chomczynski, P., and N. Sacchi (1987), Single-step method of RNA isolation by acid guanidinium thiocyanatephenol-chloroform extraction, Anal. Biochem. 162, 456-159 https://doi.org/10.1016/0003-2697(87)90021-2
  13. Shoba, L., M. R. An, S. J. Frank, and W. L. Lowe (1999), Developmental regulation of insulin-like growth factor-I and growth hormone receptor gene expression, Mol. Cell. Endoerinol. 152, 125-136 https://doi.org/10.1016/S0303-7207(99)00045-3
  14. Bradford, M. M. (1976), a rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding, Anal. Biochem. 72, 248-254 https://doi.org/10.1016/0003-2697(76)90527-3
  15. An, M. R. and W. L. Lowe (1995), The major promoter of the rat insulin-like growth factor-I gene binds a protein complex that is required for basal expression, Mol. Cell. Endocrinol. 114, 77-89 https://doi.org/10.1016/0303-7207(95)03644-M
  16. Ziegler, T. R., A. Almahfouz, M. T. Pedrini, and R. J. Smith (1995), A comparison of rat small intestinal insulin and insulin-like frowth factor I receptors during fasting and refeeding, Endocrinol. 136, 5148-5154 https://doi.org/10.1210/en.136.11.5148
  17. Fedele, M. J., T. C. Vary, and P. A. Farrell (2001), Plasticity in skeletal, cardiac, and smooth muscle selected contribution: IGF-I antibody prevents increases in protein synthesis in epitrochlearis muscles from refed, diabetic rats, J. Appl. Physiol. 90, 1166-1173 https://doi.org/10.1152/jappl.2001.90.3.1166
  18. Zhang, J., R. E. Whitehead, and L. E. Underwood (1997), Effect of fasting on insulin-like growth factor (lGF)-IA and IGF-IB messenger ribonucleic acids and prehormones in rat liver, Endocrinol. 138, 3112-3118 https://doi.org/10.1210/en.138.8.3112
  19. Lowe, W. L., C. T. Roberts, S. R. Lasky, and D. LeRoith (1987), Differential expression of alternative 5' untranslated regions in mRNAs encoding rat insulin-like growth factor I, Proc. Natl. Acad. Sci. U. S. A. 84, 8946-8950 https://doi.org/10.1073/pnas.84.24.8946
  20. Straus, D. S., and C. D. Takemoto (1990), Effect of fasting on insulin-like growth factor-I (IGF-I) and growth hormone receptor mRNA levels and IGF-I gene transcription in rat liver, Mol. Endocrinol. 4, 91-100 https://doi.org/10.1210/mend-4-1-91
  21. Lowe, W. L., R. Z. Florkiewicz, M. A. Yorej-, R. G. Spanheimer, and B. N. Albrecht (1995), Regulation of growth factor mRNA levels in the eyes of diabetic rats, Metabolism, 44, 1038-1045 https://doi.org/10.1016/0026-0495(95)90102-7
  22. Alam, T., M, R. An, R. C. Mifflin, C.-C. Hsieh, X. Ge, and J. Papaconstantinou (1993), trans-Activation of the a I-acid glycoprotein gene acute phase responsive element by multiple isoforms of C/EBP and glucocorticoid receptor, J. Biolo. Chem. 268, 15681-15688
  23. Hall, L. J., Y. Kajimoto, D. Bichell, S.-W. Kim, P. L. James, D. Counts, L.,J. Nixon, G. Tobin, and P. Rotwein (1992), Functional analysis of the rat insukin-like growth factor I gene and identification of an IGF-I gene promoter, DNA Cell Bioi. 11, 301-313 https://doi.org/10.1089/dna.1992.11.301.
  24. Umayahara, Y., C. Ji, M. Centrella, P. Rotwein, and T. L. McCarthy (1997), CCAAT/enhancer-binding protein $\delta$ activates insulin-like growth factor-I gene transcription in osteoblasts. Identification of a novel cyclic AMP signaling pathway in bone, J. BioI. Chern. 272(50), 31793-31800 https://doi.org/10.1074/jbc.272.50.31793
  25. Zhang, Z.-H., V. Kumar, R. T. Rivera, J. Chisholm, and D. K. Biswas (1990), Cis-acting negative regulatory element of prolactin gene. J. BioI. Chern. 265, 4785-4788
  26. Delany, A. M. and E. Canalis (1995), Transcriptional repression of insulin-like frowth factor I by glucocorticoids in rat bone cells, Endocrinol. 136, 4776-4781 https://doi.org/10.1210/en.136.11.4776
  27. Li, S. and R. Baserga, (1996), Epidermal growth factor and platelet-derived growth factor regulate the activity of the insulin-like growth factor I gene promoter, Exp. Gerontal. 31, 195-206 https://doi.org/10.1016/0531-5565(95)02011-X
  28. Bui, T., C. Kuo, P. Rotwein, D. S. Straus (1997), Prostaglandin $A2$ specifically represses insulin-like growth factor-I gene expression in $C6$ rat glioma cells. Endocrinol. 138, 985-993 https://doi.org/10.1210/en.138.3.985
  29. Thomas, M. J., Y. Umayahara, H. Shu, M. Centrella, P. Rotwein, and T. L. McCarthy (1996), Identification of the cAMP response element that controls transcriptional activation of the insulin-like growth factor-I gene by prostaglandin E2 in osteoblasts, J. BioI. Chern. 271, 21835-21841 https://doi.org/10.1074/jbc.271.36.21835
  30. NoJten, L. A., P. H. Steenbergh, and J. S. Sussenbach (1995), Hepatocyte nuclear factor I a activates promoter 1 of the human insulin-like growth factor I gene via two distinct binding sites, Mol. Endocrinol. 9, 1488-1499 https://doi.org/10.1210/me.9.11.1488