Az inzulinszerű növekedési faktorok (IGF-ek) létezését a porcba történő szulfátbeépítés stimulálása kapcsán ismerték fel. Az IGF-ek a növekedési hormonnal (GH) kölcsönhatásban részt vesznek az embrionális fejlődésben és a születés utáni növekedésben. Az IGF1-ek fiziológiai hatása a szövetek növekedése és fejlődése, lipid- és szénhidrát-metabolizmus, túlélés/’anti-aging’, gyulladáscsökkentő, anabolikus antioxidáns, neuro- és hepatoprotektív tulajdonságok. A GH–IGF-tengelyről szóló ismereteink szerteágazóak, részben ellentmondásosak, kutatásuk napjainkban is intenzíven folyik. Ezért tartottuk érdemesnek e hatalmas ismeretanyag áttekintését és interpretálását. A GH–IGF-szisztéma működésével kapcsolatos közlemények tanulmányozása, különös tekintettel a kevésbé ismert anyagcsere-szabályozásra. A növekedési faktorok 75%-ban a májban keletkeznek GH- és inzulinstimulációra, hatásaikat specifikus receptoraikon fejtik ki, és kötőfehérjék módosítják. Az IGF1 növeli az izomtömeget és a csontsűrűséget. A mikrobióta indukálja az IGF1-et, ami elősegíti a csontnövekedést és -átépülést. A rövid láncú zsírsavak, melyek a mikrobióták által fermentált rostokban keletkeznek, IGF1-et indukálnak, ami arra utal, hogy a mikrobióta a csont egészségét is befolyásolja. Az IGF1-nek direkt és indirekt glükózszintcsökkentő hatása is van, fokozza az izomban a szabadzsírsav-oxidációt; ez csökkenti a szabadzsírsav-beáramlást a májba, így az inzulin-jelátvitel javul, csökken a máj glükózkibocsátása. Az inzulinszerű peptidek bioaktivitását az agyban a neuronalis túlélés, az izgalmi és gátló neurotranszmisszió, a normális szabadzsírsav-szint fenntartása, a kognitív funkció javítása, a sejtkárosodás elleni védelem, neurogenezis, angiogenezis jellemzik. Az IGF1 közvetlenül befolyásolja a cirkadián BMAL1-gén expresszióját a hypothalamicus sejtekben. Ez a szabályozás az IGF1 újonnan felismert ’zeitgeber’ szerepére utal. Az IGF2 hatásai kevésbé tisztázottak, bár releváns szerepe van a fetus fejlődésében, és protektíven hat az agyra. Az IGF-ek hiánya vagy éppen túlzott jelenléte számos betegségben kimutatható, illetve ezekkel oki összefüggésbe hozható. E felismerés hasznosítása a klinikai orvostudomány legközelebbi feladatai közé tartozik. Orv Hetil. 2019; 160(45): 1774–1783.
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