Mostramos que proteínas que interagem com o promotor distal da PC podem ser possíveis alvos relacionados ao controle da função e biogênese mitocondrial e, portanto, da secreção de insulina em células pancreáticas MIN6. Em especial, nossos achados são bastante significativos por indicarem o Sp1 como um importante fator de transcrição com potencial para regular o processo de biogênese mitocondrial em células β-pancreática. O estudo dos mecanismos moleculares envolvidos na proteção das células β contra a falha da função mitocondrial/secreção de insulina, certamente, trará informações importantes na busca de novas moléculas com potencial terapêutico, capazes de melhorar a função e sobrevivência das células produtoras de insulina. O conhecimento do mecanismo pelo qual esses alvos regulam a função mitocondrial certamente poderá abrir novas perspectivas terapêuticas no controle da disfunção mitocondrial em células β e o consequente desenvolvimento DM2.
6. Referências Bibliográficas
Bradford M. 1976. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry 7(72): 248–254.
Cabrera O, Berman DM, Kenyon NS, Ricordi C, Berggren PO, Caicedo A. 2006. The unique cytoarchitecture of human pancreatic islets has implications for islet cell function. Proceedings of the National Academy of Sciences of the United States of America 103(7):2334-2339.
Cunha DA., Hekerman P, Ladriere L, Bazarra-Castro A, Ortis F, Wakeham MC, Moore F, Rasschaert J, Cardozo AK, Bellomo E, Overbergh L, Mathieu C, Lupi R, Hai T, Herchuelz A, Marchetti P, Rutter GA, Eizirik DL, Cnop M. 2008. Initiation and execution of lipotoxic ER stress in pancreatic beta-cells. J. Cell. Sci. 121, 2308–2318. DeFronzo RA, Ferrannini E. 1991. Insulin resistance. A multifaceted syndrome responsible for
NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes care 14(3):173-194.
Dominy JE and Puigserver P. 2013. Mitochondrial biogenesis through activation of nuclear signaling proteins. Cold Spring Harbor Perspectives in Biology 5(7): a015008.
Edlund H. 1998. Transcribing pancreas. Diabetes 47(12):1817-1823.
Feige JN and Auwerx J. 2007. Transcriptional coregulators in the control of energy homeostasis. Trends in Cell Biology 17(6):292-301.
Fransson U, Rosengren AH, Schuit FC, Renström E, Mulder H. 2006. Anaplerosis via pyruvate carboxylase is required for the fuel-induced rise in the ATP:ADP ratio in rat pancreatic islets. Diabetologia 49(7):1578-86.
Fu Z, Gilbert ER, Liu D. 2013. Regulation of insulin synthesis and secretion and pancreatic Beta-cell dysfunction in diabetes. Current diabetes reviews 9(1):25-53.
Gao T, McKenna B, Li C, Reichert M, Nguyen J, Singh T, Yang C, Pannikar A, Doliba N, Zhang T, Stoffers DA, Edlund H, Matschinsky F, Stein R, Stanger BZ. 2014. Pdx1 maintains beta cell identity and function by repressing an alpha cell program. Cell metabolism 19(2):259-271.
Gao T, Zhou D, Yang C, Singh T, Penzo-Mendez A, Maddipati R, Tzatsos A, Bardeesy N, Avruch J, Stanger BZ. 2013. Hippo signaling regulates differentiation and maintenance in the exocrine pancreas. Gastroenterology 144(7):1543-1553, 1553.e1541.
Gauthier BR, Wiederkehr A, Baquie M, Dai C, Powers AC, Kerr-Conte J, Pattou F, MacDonald RJ, Ferrer J, Wollheim CB. 2009. PDX1 deficiency causes mitochondrial dysfunction and defective insulin secretion through TFAM suppression. Cell metabolism 10(2):110- 118.
Grabe N. 2002. AliBaba2.1: context specific identification of transcription factor binding sites. In Silico Biology 2(1):S1-15.
Hunter CS, Stein RW. 2017. Evidence for Loss in Identity, De-Differentiation, and Trans- Differentiation of Islet beta-Cells in Type 2 Diabetes. Frontiers in genetics 8:35. Ijichi N, Shigekawa T, Ikeda K, Horie-Inoue K, Fujimura T, Tsuda H, Osaki A, Saeki T, Inoue
S. 2011. Estrogen-related receptor gamma modulates cell proliferation and estrogen signaling in breast cancer. The Journal of Steroid Biochemistry and Molecular Biology 123(1-2): 1–7.
Jensen MV, Joseph JW, Ronnebaum SM, Burgess SC, Sherry AD, Newgard CB. 2008. Metabolic cycling in control of glucose-stimulated insulin secretion. American journal of physiology Endocrinology and metabolism 295(6):E1287-1297.
Jitrapakdee S, Gong Q, MacDonald MJ, Wallace JC. 1998. Regulation of rat pyruvate carboxylase gene expression by alternate promoters during development, in genetically obese rats and in insulin-secreting cells. Multiple transcripts with 5'-end heterogeneity modulate translation. The Journal of biological chemistry 273(51):34422-34428. Kahn SE, Hull RL, Utzschneider KM. 2006. Mechanisms linking obesity to insulin resistance
and type 2 diabetes. Nature 444(7121):840-846.
Kelly DP and Scarpulla RC. 2004. Transcriptional regulatory circuits controlling mitochondrial biogenesis and function. Genes & Development 15;18(4):357-68.
Kent WJ, Sugnet CW, Furey TS, Roskin KM, Pringle TH, Zahler AM, Haussler D. 2002. The human genome browser at UCSC. Genome Research 12(6):996-1006.
Klingenberg M, Rottenberg H. 1977. Relation between the gradient of the ATP/ADP ratio and the membrane potential across the mitochondrial membrane. Eur J Biochem 73:125– 130.
Kulkarni RN. 2004. The islet beta-cell. The international journal of biochemistry & cell biology 36(3):365-371.
Lee J, Jung I, Choi S, Lee S, Lee SJ, Han SJ, Kim HJ, Kim DJ, Lee K, Kang Y. 2014. Toxicity generated through inhibition of pyruvate carboxylase and carnitine palmitoyl transferase-1 is similar to high glucose/palmitate-induced glucolipotoxicity in INS-1 beta cells. Molecular and Cellular Endocrinology 383 (2014) 48–59.
Lee SE, Koo YD, Lee JS, Kwak SH, Jung HS, Cho TM, Park YJ, Chung SS, Park KS. 2015. Retinoid x receptor α overexpression alleviates mitochondrial dysfunction-induced insulin resistance through transcriptional regulation of insulin receptor substrate. Molecules and Cells 38(4): 356–361.
Li P, Fan W, Xu J, Lu M, Yamamoto H, Auwerx J, Sears DD, Talukdar S, Oh D, Chen A, Bandyopadhyay G, Scadeng M, Ofrecio JM, Nalbandian S, Olefsky JM. 2011. Adipocyte NCoR knockout decreases PPARγ phosphorylation and enhances PPARγ activity and insulin sensitivity. Cell. 11;147(4):815-26.
Liu YQ, Jetton TL and Leahy JL. 2002. β-cell adaptation to insulin resistance - Increased pyruvate carboxylase and malate-pyruvate shuttle activity in islets of nondiabetic zucker fatty rats. The Journal of Biological Chemistry 277, 39163-39168.
Lu H, Koshkin V, Allister EM., Gyulkhandanyan AV, Wheeler MB. 2010. Molecular and metabolic evidence for mitochondrial defects associated with beta-cell dysfunction in a mouse model of type 2 diabetes. Diabetes 59,448–459.
MacDonald MJ, Longacre MJ, Langberg EC, Tibell A, Kendrick MA, Fukao T, Ostenson CG. 2009. Decreased levels of metabolic enzymes in pancreatic islets of patients with type 2 diabetes. Diabetologia 52(6):1087-1091.
Madla A. Passos et.al., 2018. Pyruvate carboxylase overexpression induces metabolic shift and improvement of mitochondrial function through increase on NAD+/NADH ratio. Manuscrito submetido a revista Biochimica et Biophysica Acta.
Martin CC, Oeser JK, O'Brien RM. 2004. Differential regulation of islet-specific glucose-6- phosphatase catalytic subunit-related protein gene transcription by Pax-6 and Pdx-1. The Journal of biological chemistry 279(33):34277-34289.
McKnight SL, Lane MD, Gluecksohn-Waelsch S. 1989. Is CCAAT/enhancer-binding protein a central regulator of energy metabolism? Genes & development 3(12b):2021-2024. Menefee AL, Zeczycki TN. 2014. Nearly 50 years in the making: defining the catalytic
mechanism of the multifunctional enzyme, pyruvate carboxylase. The FEBS journal 281(5):1333-1354.
Newgard CB. 2002. While tinkering with the beta-cell...metabolic regulatory mechanisms and new therapeutic strategies: American Diabetes Association Lilly Lecture, 2001. Diabetes 51(11):3141-3150.
Périer RC, Praz V, Junier T, Bonnard C, Bucher P. 2000. The eukaryotic promoter database (EPD) Nucleic Acids Research 28(1):302–303.
Poitout V, Robertson RP. 2008. Glucolipotoxicity: fuel excess and beta-cell dysfunction. Endocrine Reviews. 29, 351–366.
Samson SL, Wong NC. 2002. Role of Sp1 in insulin regulation of gene expression. Journal of molecular endocrinology 29(3):265-279.
Seidell JC. 2000. Obesity, insulin resistance and diabetes--a worldwide epidemic. The British journal of nutrition 83 Suppl 1:S5-8.
Silva JP, Kohler M, Graff C, Oldfors A, Magnuson MA, Berggren PO, Larsson NG. 2000. Impaired insulin secretion and beta-cell loss in tissue-specific knockout mice with mitochondrial diabetes. Nature genetics 26(3):336-340.
Scarpulla RC. 2008. Transcriptional paradigms in mammalian mitochondrial biogenesis and function. Physiolical Reviews 88(2): 611–638
Towbin H, Staehelin T, Gordon J. 1979. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.Proc Natl Acad Sci U S A. 76(9):4350-4.
Thonpho A, Rojvirat P, Jitrapakdee S, MacDonald MJ. 2013. Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells. PloS one 8(1):e55139.
Wang H, Maechler P, Ritz-Laser B, Hagenfeldt KA, Ishihara H, Philippe J, Wollheim CB. 2001. Pdx1 level defines pancreatic gene expression pattern and cell lineage differentiation. The Journal of biological chemistry 276(27):25279-25286.
Xu J, Han J, Long YS, Epstein PN, Liu YQ. 2008. The role of pyruvate carboxylase in insulin secretion and proliferation in rat pancreatic beta cells. Diabetologia 51(11):2022-2030. Yoon JC, Xu G, Deeney JT, Yang SN, Rhee J, Puigserver P, Levens AR, Yang R, Zhang CY, Lowell BB, Berggren PO, Newgard CB, Bonner-Weir S, Weir G, Spiegelman BM. 2003. Suppression of beta cell energy metabolism and insulin release by PGC-1alpha. Developmental cell 5(1):73-83.
Yu C, Markan K, Temple KA, Deplewski D, Brady MJ and Cohen RN. 2005. The nuclear receptor corepressors NCoR and SMRT decrease reroxisome proliferator-activated receptor γ transcriptional activity and repress 3T3-L1 adipogenesis.The Journal of Biological Chemistry 280, 13600-13605.
Zhang CY, Baffy G, Perret P, Krauss S, Peroni O, Grujic D, Hagen T, Vidal-Puig AJ, Boss O, Kim YB, Zheng XX, Wheeler MB, Shulman GI, Chan CB, Lowell BB. 2001. Uncoupling protein-2 negatively regulates insulin secretion and is a major link between obesity, beta cell dysfunction, and type 2 diabetes. Cell 105(6):745-755.