Effect of diflunisal and purine synthesis inhibitors on AMP-activated protein kinase and insulin action in skeletal muscle cells

Dolinar, Klemen (avtor), Pirkmajer, Sergej (mentor), Garcia-Roves, Pablo Miguel (komentor)

BACKGROUND: Skeletal muscles are an important site of glucose uptake and utilization and therefore play an important role in whole-body glucose homeostasis, making them an important target for the treatment of diabetes. One promising approach for the treatment of diabetes is activation of AMP-activated protein kinase (AMPK), as activation of AMPK has many beneficial metabolic effects, including increased basal and insulin-stimulated glucose uptake in skeletal muscles. AIM: The main aim of this study was to examine the effects of anti-inflammatory drug diflunisal and several clinically used purine synthesis inhibitors on AMPK, insulin signaling and basal and insulin-stimulated glucose uptake in skeletal muscle cells in vitro to determine if these compounds have the potential to activate AMPK and increase insulin signaling, basal and insulin-stimulated glucose uptake in skeletal muscles in vivo. Diflunisal could activate AMPK directly and/or indirectly by uncoupling mitochondria, while purine synthesis inhibitors could activate AMPK indirectly by inhibiting metabolism of purine synthesis intermediate and direct activator of AMPK 5-aminoimidazole-4-carboxamide ribonucleotide (ZMP). RESULTS: Diflunisal activated AMPK and increased basal glucose uptake but had no effect on insulin signaling or insulin-stimulated glucose uptake. Purine synthesis inhibitors had no effect or various positive or negative effects on AMPK, basal glucose uptake, insulin signaling and/or insulin-stimulated glucose uptake. One of them, mercaptopurine, activated AMPK and increased basal glucose uptake but suppressed insulin signaling and insulin-stimulated glucose uptake. Several other purine synthesis inhibitors (mycophenolate mofetil, trimetrexate and methotrexate) promoted activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR; pharmacological precursor of ZMP) and AICAR-stimulated glucose uptake. CONCLUSIONS: Our results suggest that diflunisal and some purine synthesis inhibitors have the potential to affect AMPK, basal glucose uptake, insulin signaling and/or insulin stimulated glucose uptake in skeletal muscles and thus whole-body glucose homeostasis.

• Jezik: Angleški jezik
• Ključne besede: AMP-activated protein kinase (AMPK), diflunisal, inhibitors of de novo purine synthesis, inhibitors of folate metabolism, insulin, skeletal muscle cells
• Vrsta gradiva: Doktorsko delo/naloga
• Organizacija: MF - Medicinska fakulteta
• Leto izida: 2025
• PID: 20.500.12556/RUL-177543
• Datum objave v RUL: 24.12.2025

Sekundarni jezik

• Jezik: Slovenski jezik
• Naslov: Učinek diflunisala in zaviralcev sinteze purinov na z AMP aktivirano protein kinazo in delovanje inzulina v skeletnomišičnih celicah

Izvleček

UVOD: Skeletne mišice so pomembno mesto privzema in porabe glukoze in zato pomemben igralec pri vzdrževanju homeostaze glukoze v telesu in posledično pomembna tarča za zdravljenje sladkorne bolezni. En obetaven pristop za zdravljenje sladkorne bolezni je aktivacija z AMP aktivirane protein kinaze (AMPK), saj ima aktivacija AMPK številne ugodne presnovne učinke, med katerimi je tudi povečan osnovni in z inzulinom spodbujeni privzem glukoze v skeletnih mišicah. NAMEN: Glavni namen te raziskave je bil preučiti učinke protivnetnega zdravila diflunisal in več zdravil, ki zavirajo sintezo purinov, na AMPK, osnovni privzem glukoze, inzulinsko signalizacijo in z inzulinom spodbujeni privzem glukoze v skeletnomišičnih celicah in vitro, da bi ugotovili, ali bi ta zdravila lahko povečala aktivnost AMPK, osnovni privzem glukoze, inzulinsko signalizacijo in z inzulinom-spodbujeni privzem glukoze v skeletnih mišicah in vivo. Diflunisal bi AMPK lahko aktiviral neposredno in/ali posredno preko razklopa mitohondrijev, zaviralci sinteze purinov pa bi AMPK lahko aktivirali posredno preko zavore presnove intermediata sinteze purinov in neposrednega aktivatorja AMPK 5-aminoimidazol-4-karboksamid ribonukleotida (ZMP). REZULTATI: Diflunisal je aktiviral AMPK in spodbudil osnovni privzem glukoze, na inzulinsko signalizacijo in z inzulinom spodbujeni privzem glukoze pa ni imel vpliva. Zaviralci sinteze purinov niso imeli učinka ali so imeli različne pozitivne ali negativne učinke na AMPK, osnovni privzem glukoze, inzulinsko signalizacijo in/ali z inzulinom spodbujeni privzem glukoze. Eden od njih, merkaptopurin, je aktiviral AMPK in povečal osnovni privzem glukoze, a hkrati zavrl inzulinsko signalizacijo in z inzulinom spodbujeni privzem glukoze. Več drugih zaviralcev sinteze purinov (mikofenolat mofetil, trimetreksat in metotreksat) je spodbudilo aktivacijo AMPK s 5-aminoimidazol-4-karboksamid ribonukleozidom (AICAR; farmakološki prekurzor ZMP) in z AICAR stimulirani privzem glukoze. ZAKLJUČKI: Naši rezultati kažejo, da bi diflunisal in nekateri zaviralci sinteze purinov lahko vplivali na AMPK, osnovni privzem glukoze, inzulinsko signalizacijo in/ali z inzulinom spodbujeni privzem glukoze v skeletnih mišicah in s tem tudi na homeostaze glukoze v telesu.

• Ključne besede: z AMP aktivirana protein kinaza (AMPK), diflunisal, zaviralci de novo sinteze purinov, zaviralci presnove folatov, inzulin, celice skeletnih mišic