Skip to main content

Advertisement

SpringerLink
Log in

AMP-activated protein kinase regulates normal rat somatotroph cell function and growth of rat pituitary adenomatous cells

  • Published:
Pituitary Aims and scope Submit manuscript

Abstract

AMP-activated protein kinase (AMPK) is activated under conditions that deplete cellular ATP and elevate AMP levels such as glucose deprivation and hypoxia. The AMPK system is primarily thought of as a regulator of metabolism and cell proliferation. Little is known about the regulation and the effects of AMPK in somatotroph cells. We present results from “in vitro” studies showing that AMPK activity has a role in regulating somatotroph function in normal rat pituitary and is a promising target for the development of new pharmacological treatments affecting cell proliferation and viability of pituitary adenomatous cells. In parallel, we show “in vivo” data obtained in the rat suggesting that AMPK is an intracellular transducer that may play a role in mediating the effects of the pharmacological treatment with dexamethasone on somatotrophs. In rat pituitary cell cultures, the AMP analog AICAR induced a rapid and clear-cut activation of AMPK. AICAR decreased GH release and total cellular GH content. An appropriate level of AMPK activation was essential for GH3 adenomatous cells. Remarkably, over-activation by AICAR induced apoptosis of GH3 whereas the AMPK inhibitor compound C was more effective at reducing cell proliferation. The role of endocrine or paracrine factors in regulating AMPK phosphorylation and activity in GH3 cells has been also studied. As to “in vivo” studies, western blot analysis revealed a significant decrease of phosphorylated AMPK alpha-subunit in pituitary homogenates of DEX-treated rats versus controls, suggesting reduced AMPK activity. In conclusion, our studies showed that AMPK has a role in regulating somatotroph function in normal rat pituitary and proliferation of pituitary adenomatous cells.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Tomas E, Tsao TS, Saha AK, Murrey HE, Zhang Cc C, Itani SI, Lodish HF, Ruderman NB (2002) Enhanced muscle fat oxidation and glucose transport by ACRP30 globular domain: acetyl-CoA carboxylase inhibition and AMP-activated protein kinase activation. Proc Natl Acad Sci USA 99:16309–16313

    Article  PubMed  CAS  Google Scholar 

  2. Lim CT, Kola B, Korbonits M (2009) AMPK as a mediator of hormonal signalling. J Mol Endocrinol 44:87–97

    Article  PubMed  Google Scholar 

  3. Hawley SA, Boudeau J, Reid JL, Mustard KJ, Udd L, Mäkelä TP, Alessi DR, Hardie DG (2003) Complexes between the LKB1 tumor suppressor, STRAD alpha/beta and MO25 alpha/beta are upstream kinases in the AMP-activated protein kinase cascade. J Biol 2:28

    Article  PubMed  Google Scholar 

  4. Woods A, Johnstone SR, Dickerson K, Leiper FC, Fryer LG, Neumann D, Schlattner U, Wallimann T, Carlson M, Carling D (2003) LKB1 is the upstream kinase in the AMP-activated protein kinase cascade. Curr Biol 13:2004–2008

    Article  PubMed  CAS  Google Scholar 

  5. Hurley RL, Anderson KA, Franzone JM, Kemp BE, Means AR, Witters LA (2005) The Ca2+/calmoldulin-dependent protein kinase kinases are AMP-activated protein kinase kinases. J Biol Chem 280:29060–29066

    Article  PubMed  CAS  Google Scholar 

  6. Winder WW, Hardie DG (1996) Inactivation of acetyl-CoA carboxylase and activation of AMP-activated protein kinase in muscle during exercise. Am J Physiol 270:E299–E304

    PubMed  CAS  Google Scholar 

  7. Young ME, Radda GK, Leighton B (1996) Activation of glycogen phosphorylase and glycogenolysis in rat skeletal muscle by AICAR–an activator of AMP-activated protein kinase. FEBS Lett 382:43–47

    Article  PubMed  CAS  Google Scholar 

  8. Towler MC, Hardie GD (2007) AMP-activated protein kinase in metabolic control and insulin signaling. Circ Res 100:328–341

    Article  PubMed  CAS  Google Scholar 

  9. Steinberg GR, Jorgensen SB (2007) The AMP-activated protein kinase: role in regulation of skeletal muscle metabolism and insulin sensitivity. Mini Rev Med Chem 7:521–528

    Article  Google Scholar 

  10. Locatelli V, Torsello A (2005) Pyruvate and satiety: can we fool the brain? Endocrinology 146:1–2

    Article  PubMed  CAS  Google Scholar 

  11. Josie M, Evans M (2005) Metformin and reduced risk of cancer in diabetic patients. BMJ 330:1304–1305

    Article  Google Scholar 

  12. Motoshima H, Goldstein BJ, Igata M, Araki E (2006) AMPK and cell proliferation–AMPK as a therapeutic target for atherosclerosis and cancer. J Physiol 574:63–71

    Article  PubMed  CAS  Google Scholar 

  13. Zakikhani M, Dowling R, Fantus IG, Sonenberg N, Pollak M (2006) Metformin is an AMP kinase-dependent growth inhibitor for breast cancer cells. Cancer Res 66:10269–10273

    Article  PubMed  CAS  Google Scholar 

  14. Sengupta TK, Leclerc GM, Hsieh-Kinser TT, Leclerc GJ, Singh I, Barredo JC (2007) Cytotoxic effect of 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR) on childhood acute lymphoblastic leukemia (ALL) cells: implication for targeted therapy. Mol Cancer 6:46–58

    Article  PubMed  Google Scholar 

  15. Buzzai M, Jones RG, Amaravadi RK, Lum JJ, DeBerardinis RJ, Zhao F, Villet B, Thompson CB (2007) Systemic treatment with the antidiabetic drug metformin selectively impairs p53-deficient tumor cell growth. Cancer Res 67:6745–6752

    Article  PubMed  CAS  Google Scholar 

  16. Park HU, Suy S, Danner M, Dailey V, Zhang Y, Li H, Hyduke DR, Collins BT, Gagnon G, Kallakury B, Kumar D, Brown ML, Fornace A, Dritschilo A, Collins SP (2009) AMP-activated protein kinase promotes human prostate cancer cell growth and survival. Mol Cancer Ther 8:733–741

    Article  PubMed  CAS  Google Scholar 

  17. Corton JM, Gillespie JG, Hawley SA, Hardie DG (1995) 5-Aminoimidazole-4-carboxamide ribonucleoside: a specific method for activating AMP-activated protein kinase in intact cells? Eur J Biochem 229:558–565

    Article  PubMed  CAS  Google Scholar 

  18. Rattan R, Giri S, Singh AK, Singh I (2005) 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside inhibits cancer cell proliferation in vitro and in vivo via AMP-activated protein kinase. J Biol Chem 280:39582–39593

    Article  PubMed  CAS  Google Scholar 

  19. Gao Y, Zhou Y, Xu A, Wu D (2008) Effects of an AMP-activated protein kinase inhibitor, compound C, on adipogenic differentiation of 3T3–L1 cells. Biol Pharm Bull 31:1716–1722

    Article  PubMed  CAS  Google Scholar 

  20. Kanazawa I, Yamaguchi T, Yano S, Yamauchi M, Sugimoto T (2009) Activation of AMP kinase and inhibition of Rho kinase induce the mineralization of osteoblastic MC3T3E1 cells through endothelial NOS and BMP-2 expression. Am J Physiol Endocrinol Metab 296:139–146

    Article  Google Scholar 

  21. Iwasaki Y, Nishiyama M, Taguchi T, Kambayashi M, Asai M, Yoshida M, Nigawara T, Hashimoto K (2007) Activation of AMP-activated protein kinase stimulates proopiomelanocortin gene transcription in AtT20 corticotroph cells. Am J Physiol Endocrinol Metab 292:E1899–E1905

    Article  PubMed  CAS  Google Scholar 

  22. Lu M, Tang Q, Olefsky JM, Mellon PL, Webster NJ (2008) Adiponectin activates adenosine monophosphate-activated protein kinase and decreases luteinizing hormone secretion in LβT2 gonadotropes. Mol Endocrinol 22:760–771

    Article  PubMed  CAS  Google Scholar 

  23. Müller EE, Locatelli V, Cocchi D (1999) Neuroendocrine control of growth hormone secretion. Physiol Rev 79:511–607

    PubMed  Google Scholar 

  24. Tulipano G, Soldi D, Bagnasco M, Culler MD, Taylor JE, Cocchi D, Giustina A (2002) Characterization of new selective somatostatin receptor subtype-2 (sst2) antagonists, BIM-23627 and BIM-23454. Effects of BIM-23627 on GH release in anesthetized male rats after short-term high-dose dexamethasone treatment. Endocrinology 143:1218–1224

    Article  PubMed  CAS  Google Scholar 

  25. Miller M, Chen S, Woodliff J, Kansra S (2008) Curcumin (deferuloylmethane) inhibits cell proliferation, induces apoptosis, and decreases hormone levels and secretion in pituitary tumor cells. Endocrinology 149:4158–4167

    Article  PubMed  CAS  Google Scholar 

  26. Conejo R, Lorenzo M (2001) Insulin signaling leading to proliferation, survival and membrane ruffling in C2C12 myoblats. J Cell Physiol 187:96–108

    Article  PubMed  CAS  Google Scholar 

  27. Tulipano G, Spano PF, Cocchi D (2008) Effects of olanzapine on glucose transport, proliferation and survival in C2C12 myoblasts. Mol Cell Endocrinol 292:42–49

    Article  PubMed  CAS  Google Scholar 

  28. Girnita L, Wang M, Xie Y, Nilsson G, Dricu A, Wejde J, Larsson O (2000) Inhibition of N-linked glycosylation downregulates insulin-like growth factor-1 receptor at the cell surface and kills Ewing-’s sarcoma cells: therapeutic implications. Anticancer Drug Des 15:67–72

    PubMed  CAS  Google Scholar 

  29. Suzuki A, Kusakai G, Kishimoto A, Shimojo Y, Ogura T, Lavin MF, Esumi H (2004) IGF-1 phosphorylates AMPK-alpha subunit in ATM-dependent and LKB1-independent manner. Biochem Biophys Res Commun 324:986–992

    Article  PubMed  CAS  Google Scholar 

  30. Wehrenberg WB, Bergman PJ, Stagg L, Ndon J, Giustina A (1990) Glucocorticoid inhibition of growth in rats: partial reversal with somatostatin antibodies. Endocrinology 127:2705–2708

    Article  PubMed  CAS  Google Scholar 

  31. Tulipano G, Rossi E, Culler MD, Taylor JE, Bonadonna S, Locatelli V, Cocchi D, Giustina A (2005) The somatostatin subtype-2 receptor antagonist, BIM-23627, improves the catabolic effects induced by long-term glucocorticoid treatment in the rat. Regul Pept 125:85–92

    Article  PubMed  CAS  Google Scholar 

  32. Tulipano G, Taylor JE, Halem HA, Datta R, Dong JZ, Culler MD, Bianchi I, Cocchi D, Giustina A (2007) Glucocorticoid inhibition of growth in rats: partial reversal with the full-length ghrelin analog BIM-28125. Pituitary 10:267–274

    Article  PubMed  CAS  Google Scholar 

  33. Giustina A, Veldhuis JD (1998) Pathophysiology of the neuroregulation of growth hormone secretion in experimental animals and the human. Endocr Rev 19:717–797

    Article  PubMed  CAS  Google Scholar 

  34. Davies SP, Helps NR, Cohen PT, Hardie DG (1995) 5′-AMP inhibits dephosphorylation, as well as promoting phosphorylation, of the AMP-activated protein kinase. Studies using bacterially expressed human protein phosphatase-2C{alpha} and native bovine protein phosphatase-2AC. FEBS Lett 377:421–425

    Article  PubMed  CAS  Google Scholar 

  35. Christ-Crain M, Kola B, Lolli F, Fekete C, Seboek D, Wittmann G, Feltrin D, Igreja SC, Ajodha S, Harvey-White J, Kunos G, Müller B, Pralong F, Aubert G, Arnaldi G, Giacchetti G, Boscaro M, Grossman AB, Korbonits M (2008) AMP-activated protein kinase mediates glucocorticoid-induced metabolic changes: a novel mechanism in Cushing’s syndrome. FASEB J 22:1673–1683

    Article  Google Scholar 

  36. Pollak M (2008) Insulin and insulin-like growth factor signalling in neoplasia. Nature Rev/Cancer 8:915–928

    Article  CAS  Google Scholar 

  37. Yamasaki H, Prager D, Gebremedhin S, Moise L, Melmed S (1991) Binding and action of insulin-like growth factor-1 in pituitary tumor cells. Endocrinology 128:857–862

    Article  PubMed  CAS  Google Scholar 

  38. Ceda GP, Fielder PJ, Donovan SM, Rosenfeld RG, Hoffman AR (1992) Regulation of insulin-like growth factor binding protein expression by thyroid hormone in rat GH3 pituitary tumor cells. Endocrinology 130:1483–1489

    Article  PubMed  CAS  Google Scholar 

  39. Castillo AI, Aranda A (1997) Differential regulation of pituitary specific gene expression by insulin-like growth factor-1 in rat pituitary GH4C1 and GH3 cells. Endocrinology 138:5442–5451

    Article  PubMed  CAS  Google Scholar 

  40. Wang L, Yang H, Adamo ML (2000) Glucose stravation reduces IGF-1 mRNA in tumor cells: evidence for an effect on mRNA stability. Biochem Biophys Res Comm 269:336–346

    Article  PubMed  CAS  Google Scholar 

  41. Zhou G, Myers R, Li Y, Chen Y, Shen X, Fenyk-Melody J, Wu M, Ventre J, Doebber T, Fujii N, Musi N, Hirshman MF, Goodyear LJ, Moller DE (2001) Role of AMPK-activated protein kinase in mechanism of metformin action. J Clin Invest 108:1167–1174

    PubMed  CAS  Google Scholar 

  42. Melmed S, Colao A, Barkan A, Molitch M, Grossman AB, Kleinberg D, Clemmons D, Chanson P, Laws E, Schlechte J, Vance ML, Ho K, Giustina A (2009) Guidelines for acromegaly management: an update. J Clin Endocrinol Metab 94:1509–1517

    Article  PubMed  CAS  Google Scholar 

  43. Giustina A, Chanson P, Bronstein MD, Klibanski A, Lamberts SW, Casanueva PP, Trainer P, Ghigo E, Ho K, Melmed S (2010) A consensus on criteria for cure of acromegaly. J Clin Endocrinol Metab 95:3141–3148

    Article  PubMed  CAS  Google Scholar 

Download references

Acknowledgments

This work was supported by grants (ex 60% 2007–2008) from the University of Brescia to G.T. and D.C. and a grant from Novartis Farma SpA to G.T (Italy).

Conflict of interest

M.G., D.C., V.S. have nothing to disclose. M.S. is employed by Novartis Farma SpA (Origgio, Italy). G.T. has received a research grant from Novartis in 2009. A. G. has received consulting and lecture fees from Novartis, Ipsen and Pfeizer.

Author information

Authors and Affiliations

  1. Department of Biomedical Sciences and Biotechnologies, Unit of Pharmacology, University of Brescia, Viale Europa 11, 25123, Brescia, Italy

    Giovanni Tulipano, Michela Giovannini & Daniela Cocchi

  2. Department of Medical and Surgical Sciences, Unit of Endocrinology, University of Brescia, Brescia, Italy

    Andrea Giustina

  3. Novartis Farma SpA, Origgio, Italy

    Maurizio Spinello

  4. Department of Pharmacology and Chemotherapy, University of Milan, Milan, Italy

    Valeria Sibilia

Authors
  1. Giovanni Tulipano
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Michela Giovannini
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Maurizio Spinello
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Valeria Sibilia
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Andrea Giustina
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Daniela Cocchi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Giovanni Tulipano.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tulipano, G., Giovannini, M., Spinello, M. et al. AMP-activated protein kinase regulates normal rat somatotroph cell function and growth of rat pituitary adenomatous cells. Pituitary 14, 242–252 (2011). https://doi.org/10.1007/s11102-010-0288-6

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11102-010-0288-6

Keywords

Search

Navigation