BLACK CYBER WEEK! Publikacje i multimedia nawet do 80% taniej i darmowa dostawa od 350 zł! Sprawdź >
Inhibitory karboksylazy acetylokoenzymu A
Karboksylaza acetylo-CoA katalizuje nieodwracalną karboksylację malonylo-CoA podczas biosyntezy kwasów tłuszczowych. Krążące wolne kwasy tłuszczowe i zwiększone stężenie wewnątrzkomórkowych lipotoksycznych metabolitów kwasów tłuszczowych (FACoA, DAG i ceramidy) wywołują insulinooporność w wątrobie oraz mięśniach szkieletowych i hamują wydzielanie insuliny.2 Nie zaskakuje więc wykazanie, że inhibitor karboksylazy acetylo-CoA, NDI-630, zwiększa insulinowrażliwość, zmniejsza stężenie wolnych kwasów tłuszczowych i glukozy w osoczu oraz koryguje zaburzenia lipidowe w zwierzęcych modelach otyłości i cukrzycy typu 2.139
Inne doustne leki przeciwcukrzycowe
Różne inne doustne leki przeciwcukrzycowe są obiecujące, jeżeli chodzi o poprawę glikemii w cukrzycy typu 2, w tym leki wiążące kwasy żółciowe,140 aktywatory farnezoidowego receptora X kwasów żółciowych,141 aktywatory kinazy aktywowanej przez monofosforan adenozyny (AMPK),142-144 modulatory mikroflory jelitowej,145 aktywatory syntazy glikogenu,146 inhibitory fosforylazy glikogenu147 oraz ranolazyna.148 Ranolazyna została zarejestrowana przez FDA jako lek przeciwdławicowy, który działa przez hamowanie późnego prądu sodowego w miocytach serca. Nie jest jasne, w jaki sposób wiąże się to ze zmniejszeniem stężenia HbA1C obserwowanym u chorych na cukrzycę typu 2, chociaż wykazano, że w większych dawkach niż stosowane klinicznie ranolazyna zmniejsza wydzielanie glukagonu przez komórki α trzustki przez hamowanie kanałów sodowych.149,150
W badaniach przedklinicznych wykazano, że aktywacja deacetylazy białkowej SIRT1 za pomocą SRT3025 sprzyjała redukcji masy ciała, hamowała glukoneogenezę i lipogenezę w wątrobie oraz zwiększała wrażliwość na insulinę.151 Nie wiadomo, czy podobne efekty będą obserwowane u ludzi. Ostatnio w próbie klinicznej sponsorowanej przez NIH wykazano, że kwas obetycholowy jest skuteczny w leczeniu niealkoholowej stłuszczeniowej choroby wątroby (NAFLD), a u chorych na cukrzycę typu 2 i NAFLD lek ten zwiększał wrażliwość tkanek na insulinę. Wywołało to zainteresowanie możliwością zastosowania kwasu obetycholowego w leczeniu chorych na cukrzycę typu 2.
Leki przeciwko otyłości
Obecna epidemia cukrzycy jest napędzana przez epidemię otyłości, czyli stanu przeładowania tkanek tłuszczem. Nagromadzenie lipotoksycznych metabolitów w komórkach β hamuje wydzielanie insuliny, natomiast zwiększone stężenie FACoA, DAG i ceramidów w wątrobie i mięśniach wywołuje insulinooporność.2,119 Ostatnio FDA zarejestrowała preparaty Qsymia (połączenie fenterminy i topiramatu o przedłużonym uwalnianiu) oraz Belviq (lorkaseryna) jako leki zmniejszające masę ciała u osób otyłych. Lorkaseryna jest selektywnym agonistą receptora 5-hydroksytryptaminy (serotoniny) typu C (5-HTC), który zmniejsza spożycie pokarmów przez wpływ na układ proopiomelanokortyny. Fentermina jest sympatykomimetykiem o działaniu hamującym łaknienie, natomiast topiramat jest modulatorem receptora kwasu γ-aminomasłowego, chociaż mechanizm jego działania sprzyjającego redukcji masy ciała jest słabo poznany.
W badaniu Behavioral Modification and Lorcaserin for Obesity and Overweight Management in Diabetes Meillitus (BLOOM-DM)152 lorkaseryna spowodowała zmniejszenie masy ciała o około 5%, a średniego stężenia HbA1C o około 1,0%, mimo że zużycie leków przeciwcukrzycowych się zmniejszyło. W 2-letnim badaniu SEQUEL153 kombinacja fenterminy i topiramatu zmniejszyła masę ciała o około 10%, a w podgrupie otyłych chorych na cukrzycę typu 2 spowodowała większy spadek wartości HbA1C w porównaniu z placebo i wiązała się z rzadszą potrzebą intensyfikacji leczenia przeciwcukrzycowego. W grupie pacjentów bez cukrzycy leczonych fenterminą i topiramatem zaobserwowano istotnie rzadszą progresję do cukrzycy typu 2 (0,9 vs 3,7%; p <0,001).153
Obecnie nie jest jasne, czy lorkaseryna lub połączenie fenterminy z topiramatem wywierają działanie przeciwcukrzycowe wykraczające poza efekt redukcji masy ciała. Mimo to te leki zmniejszające masę ciała skutecznie poprawiają kontrolę glikemii u otyłych chorych na cukrzycę typu 2.
Wnioski
Na cukrzycę typu 2 składa się wiele zaburzeń patofizjologicznych. Dalsze prace nad nowymi lekami mają zasadnicze znaczenie, ponieważ epidemia cukrzycy trwa i w ciągu najbliższych kilku dziesięcioleci prawdopodobnie się nasili. Opracowano i nadal opracowuje się obiecujące leki, z których część to nowe odmiany już dostępnych klas leków (agoniści receptora GLP-1, inhibitory DPP-4, inhibitory SGLT-2, metformina, tiazolidynediony/modulatory mTOT oraz leki wiążące kwasy żółciowe), niektóre są lekami przeciwko otyłości, dla których uzyskano obiecujące wyniki w odniesieniu do cukrzycy typu 2 (fentermina/topiramat oraz lorkaseryna), a inne są unikatowymi klasami, które w przyszłości znajdą ostatecznie zastosowanie w leczeniu cukrzycy lub też nie (inhibitory PDHK, inhibitory PTP-1B, analogi FGF-21, inhibitory 11-β-HSD-1, inhibitory DGAT-1, antagoniści receptora glukagonu, aktywatory glukokinazy, inhibitory fruktozo-1,6-bisfosfatazy, inhibitory karboksylazy acetylo-CoA, leki przeciwzapalne, aktywatory AMPK oraz modulatory mikroflory jelitowej). Czas ujawni prawdziwy potencjał każdego z tych kandydatów, ale nie ulega wątpliwości, że w farmakoterapii cukrzycy istnieje wiele nowych możliwości.
Copyright 2014 American Diabetes Association. From Diabetes Spectrum, Vol. 27, No. 2, 2014, p. 100. Novel agents for the treatment of type 2 diabetes. Reprinted with permission from The American Diabetes Association.
Piśmiennictwo
1. DeFronzo RA: Lilly Lecture: the triumvirate: beta cell, muscle, liver: a collusion responsible for NIDDM. Diabetes 37:667–687, 1988
2. DeFronzo RA: Banting Lecture: from the triumvirate to the ominous octet: a new paradigm for the treatment of type 2 diabetes mellitus. Diabetes 58:773–795, 2009
3. Ferrannini E, Gastaldelli A, Miyazaki Y, Matsuda M, Mari A, DeFronzo RA: Beta cell function in subjects spanning the range from normal glucose tolerance to overt diabetes mellitus: a new analysis. J Clin Endocrinol Metab 90:493–500, 2005
4. Abdul-Ghani M, Jenkinson C, Richardson D, Tripathy D, DeFronzo RA: Insulin secretion and insulin action in subjects with impaired fasting glucose and impaired glucose tolerance: results from the Veterans Administration Genetic Epidemiology Study (VAGES). Diabetes 55:1430–1435, 2006
5. Gastaldelli A, Ferrannini E, Miyazaki Y, Matsuda M, DeFronzo RA: Beta cell dysfunction and glucose intolerance: results from the San Antonio Metabolism (SAM) study. Diabetologia 47:31–39, 2004
6. Jallut D, Golay A, Munger R, Frascarolo P, Schutz Y, Jequier E, Felber JP: Impaired glucose tolerance and diabetes in obesity: a 6-year follow-up study of glucose metabolism. Metabolism 39:1068–1075, 1990
7. DeFronzo RA, Ferrannini E, Simonson DC: Fasting hyperglycemia in non-insulindependent diabetes mellitus: contributions of excessive hepatic glucose production and impaired tissue glucose uptake. Metabolism 38:387–395, 1989
8. DeFronzo RA, Gunnarssons R, Bjorkman O, Olsson M, Wahren J: Effects of insulin on peripheral and splanchnic glucose metabolism in noninsulin-dependent (type II) diabetes mellitus. J Clin Invest 76:149–155, 1985
9. Rossetti L, Giaccari A, DeFronzo RA: Glucose toxicity. Diabetes Care 13: 610– 630, 1990
10. Bays H, Mandarino L, DeFronzo RA: Role of the adipocytes, FFA, and ectopic fat in the pathogenesis of type 2 diabetes mellitus: PPAR agonists provide a rational therapeutic approach. J Clin Endocrinol Metab 89:463–478, 2004
11. DeFronzo RA, Abdul-Ghani MA: Preservation of beta cell function: the key to diabetes prevention. J Clin Endocrinol Metab 96:2354–2366, 2011
12. Abdul-Ghani M, Tripathy D, DeFronzo RA: Contribution of beta cell dysfunction and insulin resistance to the pathogenesis of impaired glucose tolerance and impaired fasting glucose. Diabetes Care 29:1130– 1139, 2006
13. Butler AE, Janson J, Bonner-Weir S, Ritzel R, Rizza RA, Butler PC: beta-cell deficit and increased β-cell apoptosis in human with type 2 diabetes. Diabetes 52:102–110, 2003
14. DeFronzo RA: Pathogenesis of type 2 diabetes: metabolic and molecular implications for identifying diabetes genes. Diabetes Rev 5:177–269, 1997
15. Groop L, Bonadonna R, Simonson DC, Petrides A, Hasan S, DeFronzo RA: Effect of insulin on oxidative and non-oxidative pathways of glucose and free fatty acid metabolism in human obesity. Am J Physiol 263:E79–E84, 1992
16. Gastaldelli A, Miyazaki Y, Pettiti M, Buzzigoli E, Mahankali S, Ferrannini E, DeFronzo RA: Separate contribution of diabetes, total fat mass, and fat topography to glucose production, gluconeogenesis, and glycogenolysis. J Clin Endocrinol Metab 89:3914–3921, 2004
17. DeFronzo RA, Tobin JD, Andres R: Glucose clamp technique: a method for quantifying insulin secretion and resistance. Am J Physiol 237:E214–E223, 1979
18. Pendergrass M, Bertoldo A, Bonadonna R, Nucci G, Mandarino L, Cobelli C, DeFronzo RA: Muscle glucose transport and phosphorylation in type 2 diabetic, obese non-diabetic, and genetically predisposed individuals. Am J Physiol Endocrinol Metab 292:E92– E100, 2007
19. Bajaj M, DeFronzo RA: Metabolic and molecular basis of insulin resistance. J Nuclear Cardiol 10:311–323, 2003
20. Cusi K, Maezono K, Osman A, Pendergrass M, Patti ME, Pratipanawatr T, DeFronzo RA, Kahn CR, Mandarino LJ: Insulin resistance differentially affects the PI 3-kinase and MAP kinase-mediated signaling in human muscle. J Clin Invest 105:311–320, 2000
21. Miyazaki Y, He H, Mandarino LJ, DeFronzo RA: Rosiglitazone improves downstream insulin-receptor signaling in type 2 diabetic patients. Diabetes 52:1943– 1950, 2003
22. Belfort R, Mandarino L, Kashyap S, Wirfel K, Pratipanawatr T, Berria R, Cusi K, DeFronzo RA: Dose response effect of elevated plasma FFA on insulin signaling. Diabetes 54:1640–1648, 2005
23. Kashyap S, Belfort R, Gastaldelli A, Pratipanawatr T, Berria R, Pratipanawatr W, Bajaj M, Mandarino L, DeFronzo RA, Cusi K: A sustained increase in plasma free fatty acids impairs insulin secretion in nondiabetic subjects genetically predisposed to develop type 2 diabetes. Diabetes 52:2461– 2474, 2003
24. Nauck M, Stockmann F, Ebert R, Creutzfeldt W: Reduced incretin effect in type 2 (non-insulin-dependent) diabetes. Diabetologia 29:46–52, 1986
25. Toft-Nielsen MB, Madsbad S, Holst JJ: Determinants of the effectiveness of glucagon-like peptide-1 in type 2 diabetes. J Clin Endocrinol Metab 86: 3853– 3860, 2001
26. Triplitt C, DeFronzo RA: Exenatide: firstin- class incretin mimetic for the treatment of type 2 diabetes mellitus. Expert Rev Endocrinol Metab 1:329–341, 2006
27. Nauck MA, Vardarli I, Deacon CF, Holst JJ, Meier JJ: Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up and what is down? Diabetologia 54:10–18, 2011
28. Kjems LL, Holst JJ, Volund A, Madsbad S: The influence of GLP-1 on glucose-stimulated insulin secretion: effects on beta-cell sensitivity in type 2 and nondiabetic subjects. Diabetes 52:380–386, 2003
29. Baron AD, Schaeffer L, Shragg P, Kolterman OG: Role of hyperglucagonemia in maintenance of increased rates of hepatic glucose output in type II diabetics. Diabetes 36:274–283, 1987
30. Matsuda M, DeFronzo RA, Glass L, Consoli A, Giordano M, Bressler P, Del Prato S: Glucagon dose response curve for hepatic glucose production and glucose disposal in type 2 diabetic patients and normal individuals. Metabolism 51:1111–1119, 2002
31. Abdul-Ghani M, Norton L, DeFronzo RA: Role of sodium-glucose cotransporter 2 (SGLT2) inhibitors in the treatment of type 2 diabetes. Endocr Rev 32:515–531, 2011
32. Wright EM, Loo DD, Hirayama BA: Biology of human glucose transporters. Physiol Rev 91:733–794, 2011
33. Farber SJ, Berger EY, Earle DP: Effect of diabetes and insulin of the maximum capacity of the renal tubules to reabsorb glucose. J Clin Invest 30:125–129, 1951
34. DeFronzo RA, Hompesch M, Kasichavanula S, Liu X, Hong Y, Pfister M, Morrow LA, Leslie BR, Boulton DW, Ching A: Characterization of renal glucose reabsorption in response to dapagliflozin in healthy subjects with type 2 diabetes. Diabetes Care 36:3169–176, 2013
35. Rahmoune H, Thompson PW, Ward JM, Smith CD, Hong G, Brown J: Glucose transporters in human renal proximal tubular cells isolated from the urine of patients with non-insulin-dependent diabetes. Diabetes 54:3427–3434, 2005
36. Matsuda M, Liu Y, Mahankali S, Pu Y, Mahankali A, Wang J, DeFronzo RA, Fox PT, Gao JH: Altered hypothalamic function in response to glucose ingestion in obese humans. Diabetes 48:1801–1806, 1999
37. Obici S, Feng Z, Tan J, Liu L, Karkanias G, Rossetti L: Central melanocortin receptors regulate insulin action. J Clin Invest 108:1079–1085, 2001
38. DeFronzo RA: Bromocriptine: a sympatholytic d2-dopamine agonist for the treatment of type 2 diabetes. Diabetes Care 34:789– 794, 2011
39. Abu-Hamdah R, Rabiee A, Meneilly GS, Shannon RP, Andersen DK, Elahi D: Clinical review: the extrapancreatic effects of glucagon- like peptide-1 and related peptides. J Clin Endocrinol Metab 94:1843–1852, 2009
40. Holst JJ: The physiology of glucagon-like peptide 1. Physiol Rev 87:1409–1439, 2007
41. Chilton R, Wyatt J, Nandish S, Oliveros R, Lujan M: Cardiovascular comorbidities of type 2 diabetes mellitus: defining the potential of glucagonlike peptide-1-based therapies. Am J Med 124 (Suppl. 1):S35–S53, 2011
42. Christensen M, Knop FK: Once-weekly GLP-1 agonists: how do they differ from exenatide and liraglutide? Curr Diab Rep 10:124–132, 2010
43. Werner U, Haschke G, Herling AW, Kramer W: Pharmacological profile of lixisenatide: a new GLP-1 receptor agonist for the treatment of type 2 diabetes. Regul Pept 164:58–64, 2010
44. Ratner RE, Rosenstock J, Boka G; DR16012 Study Investigators: Dosedependent effects of the once-daily GLP-1 receptor agonist lixisenatide in patients with type 2 diabetes inadequately controlled with metformin: a randomized, doubleblind, placebo-controlled trial. Diabet Med 27:1024–1032, 2010
45. Fonseca VA, Alvardo-Ruiz R, Raccach D, Boka G, Miossec P, Gerich JE; EFC6018 GetGoal-Mono Study Investigators: Efficacy and safety of the once-daily GLP-1 receptor agonist lixisenatide in mono-therapy: a randomized, double-blind, placebo-controlled trial in patients with type 2 diabetes (GetGoal-M). Diabetes Care 35:1225– 1231, 2012
46. Ahren B, Leguizamo Dimas A, Miossec P, Saubadu S, Aronson R: Efficacy and safety of lixisenatide once-daily morning or evening injections in type 2 diabetes inadequately controlled on metformin (GetGoal-M). Diabetes Care 36:2543–2550, 2013
47. Bolli G, Munteanu M, Dotsenko S, Niemoeller E, Boka G, Wu Y, Hanefield M: Efficacy and safety of lixisenatide oncedaily versus placebo in patients with T2DM insufficiently controlled on metformin (GetGoal-F1). Diabet Med 2013 Sep 30. Epub ahead of print (doi: 10.1111/dme.12328)
48. Pinget M, Goldenberg R, Niemoeller E, Muehlen-Bartmer I, Guo H, Aronson R: Efficacy and safety of lixisenatide once daily versus placebo in patients with type 2 diabetes insufficiently controlled on pioglitazone (GetGoal-P). Diabetes Obes Metab 15:1000– 1007, 2013
49. Riddle MC, Aronson R, Home P, Marre M, Niemoeller E, Miossec P, Ping L, Ye J, Rosenstock J: Adding once-daily lixisenatide for type-2 diabetes inadequately conrolled by established basal insulin: a 24-week, randomized, placebo-controlled comparison (GetGoal-L). Diabetes Care 36:2489– 2496, 2013
50. Seino Y, Min KW, Niemoeller E, Takami A; EFC10887 GETGOAL-L Asia Study Investigators: Randomized, double-blind, placebo-controlled trial of the once-daily GLP-1 receptor agonist lixisenatide in Asian patients with type 2 diabetes insufficiently controlled on basal insulin with or without a sulfonylurea (GetGoal-L-Asia). Diabetes Obes Metab 14:910–917, 2012
51. Rosenstock J, Raccah D, Koranyi L, Maffei L: Efficacy and safety of lixisenatide once daily versus exenatide twice daily in type 2 diabetes inadequately controlled on metformin. Diabetes Care 36:2945–2951, 2013
52. Buse J, Gough SCL, Woo V, Rodbard H, Linjawi S, Poulsen, P, Damgaard LH, Bode BW: IDegLira, a novel fixed ratio combination of insulin degludec and liraglutide, is efficacious and safe in subjects with type 2 diabetes: a large, randomized phase 3 trial [Abstract]. Diabetes 62 (Suppl. 1):A16, 2013
53. Gough SCL, Buse JB, Woo BC, Rodbard HW, Linjawi S, Poulsen P, Damgaard LH, Bode BW: IDegLira, a novel fixed ratio combination of insulin degludec and liraglutide, is efficacious and safe in subjects with type 2 diabetes [Abstract]. Diabetologia 56 (Suppl. 1):S96–S97, 2013
54. St. Onge LE, Miller AS: Albiglutide: a new GLP-1 analog for the treatment of type 2 diabetes. Expert Opin Biol Ther 10:801– 806, 2010
55. Pratley ER, Barnett A, Feinglos MM, Harman-Boehm I, Nauck M, Ovalle F, Johnson S, Stewart M, Ye J, Rosenstock J: Efficacy and safety of once-weekly (QW) albiglutide vs. once-daily (QD) liraglutide in type 2 diabetes (T2D) inadequately controlled on oral agents [Abstract]. Diabetes 61 (Suppl. 1):A240, 2012
56. Luskey K, Rosenstock J, Alessi T, Henry RR: Long-term, injection-free treatment with ITCA 650, a continuous subcutaneous delivery of exentide via DUROS device, leads to stable glycaemic and weight control for 48 weeks in metformin-treated type 2 diabetes [Abstract]. Diabetologia 54 (Suppl. 1):S39, 2011
57. Wysham C, Blevins T, Arakaki R, Colon G, Garcia P, Atisso C, Kuhstoss D, Bacon- Scism J, Lakshmanan M: Efficacy and safety of dulaglutide versus placebo and exenatide in type 2 diabetes (Award-1) [Abstract]. Diabetes 62 (Suppl. 1):A16, 2013
58. Umpierrez GE, Manghi FP, Povedano S, Shurzinske L, Pechtner V: Efficacy and safety of dulaglutide vs metformin in type 2 diabetes (Award-3) [Abstract]. Diabetes 62 (Suppl. 1):A17, 2013
59. Nauck MA, Petrie JR, Sesti G, Mannucci E, Courreges JP, Atkin S, During M, Jensen CB, Heller S: The once-weekly human GLP-1 analogue semaglutide provides significant reductions in HbA1c and body weight in patients with type 2 diabetes [Abstract]. Diabetologia 55 (Suppl. 1):S7, 2012
60. Krishna R, Addy C, Tatosian D, Hou XS, Gendrano IN, Martucci AN, Wagner JA, Stoch SA: Single/multiple dose pharmacokinetics (PK) and pharmacodynamics (PD) of omarigliptin, a once-weekly dipeptidyl peptidase- 4 (DPP-4) inhibitor, in healthy subjects [Abstract]. Diabetes 62 (Suppl. 1):A284, 2013
61. Gantz I, Chen M, Mirza A, Suryawanshi S, Davies MJ, Goldstein BJ: Effect of MK-3102, a novel once-weekly DPP-4 inhibitor, over 12 weeks in patients with type 2 diabetes mellitus [Abstract]. Diabetologia 55 (Suppl. 1):S51, 2012
62. Nagasumi K, Esaki R, Iwachidow K, Yasuhara Y, Ogi K, Tanaka H, Nakata M, Yano T, Shimakawa K, Taketomi S, Takeuchi K, Odaka H, Kaisho Y: Overexpression of GPR40 in pancreatic beta-cells augments glucose-stimulated insulin secretion and improves glucose tolerance in normal and diabetic mice. Diabetes 58:1067–1076, 2009
63. Burant CF, Viswanathan P, Marcinak J, Cao C, Vakilynejad M, Xie B, Leifke E: TAK- 875 versus placebo or glimepiride in type 2 diabetes mellitus; a phase 2, randomised, double-blind, placebo-controlled trial. Lancet 379:1403–1411, 2012
64. Hansen KB, Knop FK, Anderson NW, Diep TA, Rosenkilde MM, Holst JJ, Hansen HH: A naturally occurring ligand activates the GPR119 receptor and induces secretion of GLP-1 in vivo [Abstract]. Diabetes 59 (Suppl. 1):A174, 2010
65. Nagarathnam D, Varanasi K, Routhu K, Muthuppalaniappan M, Merikapudi G, Veeraraghavan S, Prasanna R, Viswanadha S, Vakkalanka S: Anti-diabetic potential of novel, small molecule GPR119 agonists [Abstract]. Diabetes 61 (Suppl. 1):A76, 2012
66. Du F, Carroll C, Chu Z, Lehmann J, Jones MR, Xu J, Leonard J, Sarich T, Gordon- Andrade P, Demarest K, Liang Y: The GPR119 agonist JNJ-38431055/APD597 improves blood glucose control in rats and cynomologous monkeys [Abstract]. Diabetes 61 (Suppl. 1):A76, 2012
67. Fell JB, Williams LL, Mcvean M, Lee P, Neitzel NA, Larson P, Baer B, Aicher TD, Boyd SA, Hinklin RJ, Turner TM, Fischer JP, Winkler JD, Koch K: ARRY-981, a novel GPR119 agonist with durable reductions in blood glucose levels [Abstract]. Diabetes 61 (Suppl. 1):A288, 2012
68. Barnes WG, Nguyen L, Reinhart G, Doebel- Hickok M, Diggs J, Dyck B, Tran J, Harriott ND, Johns M, O-Brien J, Grigoriadis DE: GPR119 demonstrates robust tachyphylaxis following chronic administration of small molecule agonists in Zucker diabetic fatty (ZDF) rats [Abstract]. Diabetes 59 (Suppl. 1):A185, 2010
69. Nunez DJ, Bush MA, Collins DA: Evaluation of GSK1292263, a novel GPR119 agonist, in type 2 diabetes mellitus (T2DM): safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of single and multiple doses [Abstract]. Diabetes 60 (Suppl. 1):A273, 2011
70. Cefalu WT, Leiter LA, Yoon K, Arias P, Niskanen L, Xie J, Balis DA, Canovatchel W, Meininger G: Efficacy and safety of canagliflozin versus glimepiride in patients with type 2 diabetes inadequately controlled with metformin (CANTATA-SU): 52 week results from a randomised, double-blind, phase 3 non-inferiority trial. Lancet 382:941– 950, 2013
71. Schernthaner G, Gross JL, Rosenstock J, Guarisco M, Fu M, Yee J, Kawaguchi M, Canovatchel W, Meininger G: Canagliflozin compared with sitagliptin for patients with type 2 diabetes who do not have adequate glycemic control with metformin plus sulfonylurea. Diabetes Care 36:2508–2515, 2013
72. Liu JJ, Lee T, DeFronzo RA: Why do SGLT2 inhibitors inhibit only 30–50% of renal glucose reabsorption in humans? Diabetes 61:2199–2204, 2012
73. Abdul-Ghani MA, Norton L, DeFronzo RA: Role of sodium-glucose contransporter 2 (SGLT 2) inhibitors in the treatment of type 2 diabetes. Endocr Rev 32: 515–531, 2011
74. DeFronzo RA, Hompesch M, Kasichayanula S, Liu X, Hong Y, Pfister M, Morrow LA, Leslie BR, Boulton DW, Ching A, LaCreta FP, Griffin SC: Characterization of renal glucose reabsorption in response to dapagliflozin in healthy subjects and subjects with type 2 diabetes. Diabetes Care 36:3169–3176, 2013
75. Washburn WN, Poucher SM: Differentiating sodium-glucose co-transporter- 2 inhibitors in development for the treatment of type 2 diabetes mellitus. Expert Opin Investig Drugs 22:463–486, 2013
76. Merovci A, Solis-Herrera C, Daniele G, Eldor R, Fiorentino T, Tripathy D, Xiong J, Perez Z, Norton L, Abdul-Ghani MA, DeFronzo RA: Dapagliflozin improves muscle insulin sensitivity but enhances glucose production. J Clin Invest 124: 509–514, 2014
77. List JF, Woo V, Morales E, Tang W, Fiedorek FT: Sodium-glucose cotransport inhibition with dapagliflozin in type 2 diabetes. Diabetes Care 32:650–657, 2009
78. Zhang L, Feng Y, List J, Kasichayanula S, Pfister M: Dapagliflozin treatment in patients with different stages of type 2 diabetes mellitus: effects on glycaemic control and body weight. Diabetes Obes Metab 12:510– 516, 2010
79. Wilding JP, Norwood P, T’Joen C, Bastien A, List JF, Fiedorek FT: A study of dapagliflozin in patients with type 2 diabetes receiving high doses of insulin plus insulin sensitizers: applicability of a novel insulinindependent treatment. Diabetes Care 32:1656–1662, 2009
80. Haring H, Merker L, Becker-Seewaldt E, Weimer M, Meinicke T, Woerle HJ, Broedel UC, on behalf of the EMPA-REG METSU Trial Investigators: Empagliflozin as add-on to metformin plus sulfonylurea in patients with type 2 diabetes. Diabetes Care 36:3396–3404, 2013
81. Ferrannini E, Berk A, Hantel S, Pinnetti S, Hach T, Woerle HJ, Broedl UC: Long term safety and efficacy of empagliflozin, sitagliptin, and metformin: an active-controlled, parallel-group, randomized, 78-week open label extension study in patients with type 2 diabetes. Diabetes Care 36:4014–4021, 2013
82. Wright EM, Loo DD, Hirayama BA: Biology of human sodium glucose transporters. Physiol Rev 91:733–794, 2011
83. Powell DR, DaCosta CM, Gay J, Ding ZM, Smith M, Greer J, Doree D, Jeter-Jones S, Mseeh F, Rodriguez LA, Harris A, Buhring L, Platt KA, Vogel P, Brommage R, Shadoan MK, Sands AT, Zambrowicz B: Improved glycemic control in mice lacking SGLT1 and SGLT2. Am J Physiol Endocrinol Metab 304:E117–E130, 2013
84. Powell D, Smith M, Doree D, Harris A, Thompson A, Greer J, DaCosta C, Thompson A, Liu J, Jeter-Jones S, Carson K, Goodwin N, Harrison B, Rawlins D, Strobel E, Mseeh F, Sands A, Zambrowicz B, Ding ZM: LX2761, an SGLT1 inhibitor restricted to the intestine, improves glycemic control in mice [Abstract]. Diabetes 62 (Suppl. 1):A62, 2013
85. Powell DR, Smith M, Greer J, Harris A, Zhao S, DaCosta C, Mseeh F, Shadoan MK, Sands MK, Sands A, Zambrowicz B, Ding ZM: LX4211 increases serum GLD-1 PYY levels by reducing SGLT-1 mediated absorption of intestinal glucose. J Pharmacol Exp Ther 345:250–259, 2013
86. Zambrowicz B, Ding ZM, Ogbaa I, Frazier K, Banks P, Turnage A, Freiman J, Smith M, Ruff D, Sands A, Powell D: Effects of LX4211, a dual SGLT1/SGLT2 inhibitor, plus sitagliptin on postprandial active GLP-1 and glycemic control in type 2 diabetes. Clin Ther 35:273–285, 2013
87. Zambrowicz B, Freiman J, Brown PB, Frazier KS, Turnage A, Bronner J, Ruff D, Shadoan M, Banks P, Mseeh F, Rawlins DB, Goodwin NC, Mabon R, Harrison BA, Wilson A, Sands A, Powell DR: LX4211, a dual SGLT1/SGLT2 inhibitor, improved glycemic control in patients with type 2 diabetes in a randomized, placebo-controlled trial. Clin Pharmacol Ther 92:158–169, 2012
88. Lapuerta P, Rosenstock J, Zambrowicz B, Powell DR, Ogbaa I, Freiman J, Cefalu WT, Banks P, Frazier K, Kelly M, Sands A: Study design and rationale of a dose-ranging trial of LX4211, a dual inhibitor of SGLT1 and SGLT2, in type 2 diabetes inadequately controlled on metformin monotherapy. Clin Cardiol 36:367–371, 2013
89. Cusi K, DeFronzo RA: Metformin: a review of its metabolic effects. Diabetes Rev 6:89–131, 1998
90. Stepensky D, Friedman M, Raz I, Hoffman A: Pharmacokinetic-pharmacodynamic analysis of the glucose-lowering effect of metformin in diabetic rats reveals first-pass pharmacodynamics effect. Drug Metab Dispos 30:861–868, 2002
91. Mannucci E, Ognibene A, Cremasco F, Bardini G, Mencucci A, Pierazzuoli E, Ciani S, Messeri G, Rotella CM: Effect of metformin on glucagon-like peptide 1 (GLP-1) and leptin levels in obese nondiabetic subjects. Diabetes Care 24:489–494, 2001
92. DeFronzo RA, Buse JB, Kim T, Skare S, Baron A, Fineman M: Dissociation between metformin plasma exposure and its glucoselowering effect: a novel gut-mediated mechanism of action [Abstract]. Diabetes 62 (Suppl. 1):A281, 2013
93. Cusi K, Consoli A, DeFronzo RA: Metabolic effects of metformin on glucose and lactate metabolism in noninsulin-dependent diabetes mellitus. J Clin Endocrinol Metab 81:4059–4067, 1996
94. Chen Z, Vigueira PA, Chambers KT, Hall AM, Mitra MS, Qi N, McDonald WG, Colca JR, Kletzien RF, Finck BN: Insulin resistance and metabolic derangements in obese mice are ameliorated by a novel peroxisome proliferator-activated receptor γ-sparing thiazolidinedione. J Biol Chem 287:23537– 23548, 2012
95. Colca JR, Tanis SP, McDonald WG, Kletzien RF: Insulin sensitizers in 2013: new insights for the development of novel therapeutic agents to treat metabolic diseases. Expert Opin Investig Drugs 23:1–7, 2014
96. Colca JR, VanderLugt JT, Adams WJ, Shashlo A, McDonald WG, Liang J, Zhou R, Orloff DG: Clinical proof-of-concept study with MSDC-0160, a prototype mTOT-modulating insulin sensitizer. Clin Pharmacol Ther 93:352–359, 2013
97. Stacpoole PW: The pyruvate dehydrogenase complex as a therapeutic target for age-related diseases. Aging Cell 11:371–377, 2012
98. Jeoung NH, Harris RA: Role of pyruvate dehydrogenase kinase 4 in regulation of blood glucose levels. Korean Diabetes J 34:274– 283, 2010
99. Taniguchi CM, Emanuelli B, Kahn CR: Critical nodes in signaling pathways: insights into insulin action. Nat Rev Mol Cell Biol 7:85–96, 2006
100. Popov D: Novel protein tyrosine phosphatase 1B inhibitors: interaction requirements for improved intracellular efficacy in type 2 diabetes mellitus and obesity control. Biochem Biophys Res Commun 410:377–381, 2011
101. Thareja S, Aggarwal S, Bhardwaj TR, Kumar M: Protein tyrosine phosphatase 1B inhibitors: a molecular level legitimate approach for the management of diabetes mellitus. Med Res Rev 32:459–517, 2012
102. Elchebly M, Payette P, Michaliszyn E, Cromlish W, Collins S, Loy AL, Normandin D, Cheng A, Himms-Hagen J, Chan CC, Ramachandran C, Gresser MJ: Increased insulin sensitivity and obesity resistance in mice lacking the protein tyrosine phosphatase-1B gene. Science 283:1544–1548, 1999
103. Brandt TA, Crooke ST, Ackermann EJ, Xia S, Morgan ES, Liu Q, Geary RS, Bhanot S: ISIS 113715, a novel PTP-1B antisense inhibitor, improves glycemic control and dyslipidemia and increases adiponectin levels in T2DM subjects uncontrolled on stable sulfonylurea therapy [Abstract]. Diabetes 59 (Suppl. 1):A84, 2010
104. Kralisch S, Fasshauer M: Fibroblast growth factor 21: effects on carbohydrate and lipid metabolism in health and disease. Curr Opin Clin Nutr Metab Care 14:354–359, 2011
105. Gaich G, Chien JY, Fu H, Glass LC, Deeg MA, Holland WL, Kharitonenkov A, Bumol T, Schilske HK, Moller DE: The effects of LY2405319, an FGF21 analog, in obese human subjects with type 2 diabetes. Cell Metab 18:333–340, 2013
106. Gaich G, Chien J, Fu, H, Kharitonenkov A, Moller D: Effects of an FGF21 analog in patients with type 2 diabetes [Abstract]. Diabetes 62 (Suppl. 1):A28, 2013
107. Ge R, Huang Y, Liang G, Li X: 11betahydroxysteriod dehydrogenase type 1 inhibitors as promising therapeutic drugs for diabetes: status and development. Curr Med Chem 17:412–422, 2010
108. Fuerst-Recktenwald S, Heise T, Hompesch M, Pieber H, Haering U, Kapitza C, Abt M, Ramsauer M, Morrow L: Metabolic effects and safety of two selective 11β-HSD1 inhibitors (RO5093151 [RO151] and RO5027838 [RO838]) in metformin-treated patients with type 2 diabetes [Abstract]. Diabetologia 56 (Suppl. 1):S407–S408, 2013
109. Hawkins M, Hunter D, Kishore P, Schwartz S, Hompesch M, Hollis G, Levy R, Williams B, Huber R: INCB013739, a selective inhibitor of 11β-hydroxysteriod dehydrogenase type 1 (11βHSD1), improves insulin sensitivity and lowers plasma cholesterol over 28 days in patients with type 2 diabetes mellitus [Abstract]. Diabetes 57 (Suppl. 1):A99–A100, 2008
110. Andrews RC, Rooyackers O, Walker BR: Effects of the 11 beta-hydroxysteriod dehydrogenase inhibitor carbenoxolone on insulin sensitivity in men with type 2 diabetes. J Clin Endocrinol Metab 88:285–291, 2003
111. Feig PU, Shah S, Hermanowski-Vosatka A, Plotkin D, Springer MS, Donahue S, Thach C, Klein EJ, Lai E, Kaufman KD: Effects of an 11β-hydroxysteriod dehydrogenase type 1 inhibitor, MK-0916, in patients with type 2 diabetes mellitus and metabolic syndrome. Diabetes Obes Metab 13:498–504, 2011
112. Morrow L, Heise T, Hompesch M, Pieber RT, Haering H, Kapitza C, Abt M, Ramsauer M, Fuerst-Recktenwald S: Metabolic effects and safety of two selective 11β-HSD1 inhibitors (RO5093151 [RO151] and RO5027838 [RO838]) in metformin-treated patients with type 2 diabetes (T2D) [Abstract]. Diabetes 62 (Suppl. 1):A293, 2013
113. Birch AM, Buckett LK, Turnbull AV: DGAT1 inhibitors as anti-obesity and antidiabetic agents. Curr Opin Drug Discov Devel 13:489–496, 2010
114. Denison H, Nilsson C, Kujacic M, Lofgren L, Karlsson C, Knutsson M, Eriksson JW: Proof of mechanism for the DGAT1 inhibitor AZD7687: results from a first-time-in-human single-dose study. Diabetes Obes Metab 15:136–143, 2013
115. Liu L, Zhang Y, Chen N, Shi X, Tsang B, Yu YH: Upregulation of myocellular DGAT1 augments triglyceride synthesis in skeletal muscle and protects against fat induced insulin resistance. J Clin Invest 117:1679–1689, 2007
116. Wellen KE, Hotamisligil GS: Obesityinduced inflammatory changes in adipose tissue. J Clin Invest 112:1785–1788, 2003
117. Ye J, Gao Z, Yin J, He Q: Hypoxia is a potential risk factor for chronic inflammation and adiponectin reduction in adipose tissue of ob/ob and dietary obese mice. Am J Physiol Endocrinol Metab 293:E1118–E1128, 2007
118. Gao ZG, Ye JP: Why do anti-inflammatory therapies fail to improve insulin sensitivity? Acta Pharmacol Sin 32:182–188, 2012
119. DeFronzo RA: Insulin resistance, lipotoxicity, type 2 diabetes and atherosclerosis: the missing links: the Claude Bernard Lecture 2009. Diabetologia 53:1270–1287, 2010
120. Fleischman A, Shoelson SE, Bernier R, Goldfine AB: Salsalate improves glycemia and inflammatory parameters in obese young adults. Diabetes Care 31:289–294, 2007
121. Sriwijitkamol A, Christ-Roberts C, Berria R, Eagan P, Pratipanawatr T, DeFronzo RA, Mandarino LJ, Musi N: Reduced skeletal muscle inhibitor of kappaB beta content is associated with insulin resistance in subjects with type 2 diabetes: reversal by exercise training. Diabetes 55:760–777, 2006
122. Yin MJ, Yamamoto Y, Gaynor RB: The anti-inflammatory agents aspirin and salicylate inhibit the activity of I(kappa) kinase-beta. Nature 396:77–80, 1998
123. Shoelson SE, Lee J, Goldfine AB: Inflammation and insulin resistance. J Clin Invest 116:1793–801, 2006
124. Goldfine AB, Fonseca V, Jablonski KA, Pyle L, Staten MA, Shoelson SE; TINSALT2D (Targeting inflammation Using Salsalate in Type 2 Diabetes) Study Team: The effects of salsalate on glycemic control in patients with type 2 diabetes: a randomized trial. Ann Intern Med 152:346–357, 2010
125. Goldfine AB, Fonseca V, Jablonski KA, Chen YD, Tipton L, Staten MA, Shoelson SE; Targeting Inflammation Using Salsalate (salsalate) in patients with type 2 diabetes: a randomized trial. Ann Intern Med 159:1–12, 2013
126. Sorensen H, Brand CL, Neschen S, Holst JJ, Fosgerau K, Nishimura E, Shulman GI: Immunoneutralization of endogenous glucagon reduces hepatic glucose output and improves long-term glycemic control in diabetic ob/ob mice. Diabetes 55:2843–2848, 2006
127. Mu J, Jiang G, Brady E, Dallas-Yang Q, Liu F, Woods J, Zycband E, Wright M, Li Z, Lu K, Zhu L, Shen X, Sinharoy R, Candelore ML, Qureshi SA, Shen DM, Zhang F, Parmee ER, Zhang BB: Chronic treatment with a glucagon receptor antagonist lowers glucose and moderately raises circulating glucagon and glucagon peptide 1 without severe alpha cell hypertrophy in diet-induced obese mice. Diabetologia 54:2381–2391, 2011
128. Engel SS, Reitman ML, Xu L, Andryuk PJ, Davies MJ, Kaufman KD, Goldstein BJ: Glycemic and lipid effects of the short-acting glucagon receptor antagonist MK-3577 in patients with type 2 diabetes [Abstract]. Diabetes 61 (Suppl. 1):A266, 2012
129. Kazda C, Headlee S, Ding Y, Kelly RP, Garhyan P, Hardy TA, Lewin A: The glucagon receptor antagonist LY2409021 significantly lowers HbA1c and is well tolerated in patients with T2DM: a 24 week phase 2 study [Abstract]. Diabetes 62 (Suppl. 1):A29, 2012
130. Matschinsky FM, Zelent B, Doliba N, Li C, Vanderooi JM, Naji A, Sarabu R, Grimsby J: Glucokinase activators for diabetes therapy. Diabetes Care 34: S236–S243, 2010
131. TransTech Pharma: First liver-selective glucokinase activator for type 2 diabetes demonstrates normalized HbA1c and no hypoglycemia in clinical trial [Press Release]. Available from http://www.ttpharma.com/PressReleases/2013/20130814TransTechPharmaPressRelease/tabid/253/Default.aspx. Accessed 16 January 2014
132. Ramanathan V, Vachharajani N, Patel R, Barbhaiya R: GKM-001, a liver-directed/pancreas-sparing glucokinase modulator (GKM), lowers fasting and post-prandial glucose without hypoglycemia in type 2 diabetic (T2D) patients [Abstract]. Diabetes 61 (Suppl. 1):A76, 2012
133. Mookhtiar KA, Umrani D, De S, Bhuniya D: The liver-directed/pancreas-sparing pharmacokinectic profile of GKM-001, a glucokinase modulator with robust glucose lowering properties and low hypoglycemia risk [Abstract]. Diabetes 61 (Suppl. 1):A291, 2012
134. Kazierad D, Bergman A, Pfefferkorn JA, Wang X, Rolph T, Rusnak JM: Pharmacokinetics (PK) and pharmacodynamics (PD) of PF-04991532, a hepatoselective glucokinase activator (GKA), administered as monotherapy in Japanese and non Japanese T2DM patients [Abstract]. Diabetes 62 (Suppl. 1):A287, 2013
135. Pilkis SJ, Claus TH, Kurland IJ, Lange AJ: 6-Phosphofructo-2-kinase/fructose-2, 6-bisphosphatase: a metabolic signaling enzyme. Annu Rev Biochem 64:799–835, 1995
136. Erion MD, van Poelje PD, Dang Q, Kasibhatla SR, Potter SC, Reddy MR, Reddy KR, Jiang T, Lipscomb WN: MB06322 (CS-917): A potent and selective inhibitor of fructose 1, 6-bisphosphatase for controlling gluconeogenesis in type 2 diabetes. Proc Natl Acad Sci U S A 102:7970–7975, 2005
137. Van Poelje PD, Potter SC, Chandramouli VC, Landau BR, Dang Q, Erion MD: Inhibition of fructose 1, 6-biphosphatase reduces excessive endogenous glucose production and attenuates hyperglycemia in Zucker diabetic fatty rats. Diabetes 55:1747–1754, 2006
138. Gumbiner B, Van Poelje P, Bullough D, Watling S, Milad M, Stern T, Foyt H, Erion M: Pronounced glucose (G) reduction in poorly controlled T2DM with MB07803, a novel fructose-1,6-bisphosphatase inhibitor (FBPaseI) with reduced potential for acid-base disturbance vs the 1st generation FBPaseI CS-917 [Abstract]. Diabetes 58 (Suppl. 1A):LB4, 2009
139. Harriman G, Greenwood J, Bhat S, Kapeller R, Harwood JH: Acetyl-CoA carboxylase inhibition by NDI-630 inhibits fatty acid synthesis stimulates fatty acid oxidation, reduces body weight, improvise insulin sensitivity, and modulates dyslipidemia in rats [Abstract]. Diabetes 62 (Suppl. 1):A161, 2013
140. Hansen M, Mikkelsen KH, Sonne DP, Gluud LL, Vilsboll T, Knop FK: Bile acid sequestrants for glycemic control in type 2 diabetes: a systematic review with metaanalysis of randomized controlled trials [Abstract]. Diabetes 62 (Suppl. 1):A305, 2013
141. Mudaliar S, Henry RR, Sanyal AJ, Morrow L, Marschall HU, Kipnes M, Adorini L, Sciacca CI, Clopton P, Castelloe E, Dillon P, Pruzanski M, Shapiro D: Efficacy and safety of the farnesoid X receptor agonist obeticholic acid in patients with type 2 diabetes and nonalcoholic fatty liver disease. Gastroenterology 145:574–582, 2013
142. Pillarisetti S, Khanna I: Discovery of an orally efficacious, novel AMPK activator as potent insulin sensitizer [Abstract]. Diabetes 62 (Suppl. 1):A271, 2013
143. Hardie G: AMPK: a target for drugs and natural products with effects on both diabetes and cancer. Diabetes 62:2164–2172, 2013
144. Schimmack G, DeFronzo RA, Musi N: AMP-activated protein kinase: role in metabolism and therapeutic implications. Diabetes Obes Metab 8:591–602, 2006
145. Karlsson F, Tremaroli V, Nielsen J, Backhed F: Assessing the human gut microbiota in metabolic diseases. Diabetes 62:3341–3349, 2013
146. MacAulay K, Woodgett JR: Targeting glycogen synthase kinase-3 (GSK-3) in the treatment of type 2 diabetes. Expert Opin Ther Targets 12:1265–1274, 2008
147. Somsak L, Czifrak K, Toth M, Bokor E, Chrysina ED, Alexacou K-M, Hayes JM, Tiraidis C, Lazoura E, Leonidas DD, Zographos SE, Oikonomakos NG: New inhibitors of glycogen phosphorylase as potential antidiabetic agents. Curr Med Chem 15:2933–2983, 2008
148. Morrow DA, Scirica BM, Chaitman BR, McGuire DK, Murphy SA, Karwatowska-Prokopczuk E, McCabe CH, Braunwald E; for MERLIN-TIMI 36 Investigators: Evaluation of the glycometabolic effects of ranolazine in patients with and without diabetes mellitus in the MERLIN-TIMI 36 randomized controlled trial. Circulation 119:2032–2039, 2009
149. Kahlig K, Yang M, Xie C, Rajamani S, Dhalla AK, Belardinelli L: The mechanism of the anti-diabetic effect of ranolazine: inhibition of glucagon secretion in rat pancreatic islets via Na+ channel blockade [Abstract]. Diabetes 62 (Suppl. 1):A272, 2013
150. Dhalla A, Yang M, Chu R, Belardinelli L: Ranolazine inhibits glucagon secretion from human pancreatic islets via blockade of NAv1.3 channels in α-cells [Abstract]. Diabetes 62 (Suppl. 1):A277, 2013
151. Suri V, Qi Y, Davis ML, Nie Q, Johnson MO, Cote AM, Lainez E, Vlasuk GP, Ellis JL: SRT3025, a novel SIRT1 activator, reverses metabolic dysfunction induced by a high fat diet through transcriptional and post transcriptional modulation of multiple metabolic pathways [Abstract]. Diabetes 61 (Suppl. 1):A75, 2012
152. O’Neil PM, Smith SR, Weissman NJ, Fidler MC, Sanchez M, Zhang J, Raether B, Anderson CM, Shanahan WR: Randomized placebo-controlled clinical trial of lorcaserin for weight loss in type 2 diabetes mellitus: the BLOOM-DM study. Obesity (Silver Spring) 20:1426–1436, 2012
153. Garvey WT, Ryan DH, Look M, Gadde KM, Allison DB, Peterson CA, Schwiers M, Day WW, Bowden CH: Two-year sustained weight loss and metabolic benefits with controlled-release phentermine/topiramate in obese and overweight adults (SEQUEL): a randomized, placebo-controlled, phase 3 extension study. Am J Clin Nutr 95:297–308, 2012