Ghrelin, Reseptor Ghrelin dan SNP Reseptor Ghrelin Terkait Obesitas dan Sindrom Metabolik
Abstract
Ghrelin merupakan hormon peptida yang terutama diproduksi oleh lambung dan berperan penting dalam regulasi keseimbangan energi, nafsu makan, metabolisme glukosa, serta homeostasis lipid. Efek biologis ghrelin dimediasi melalui Growth Hormone Secretagogue Receptor (GHS-R), khususnya subtipe GHS-R1a yang banyak diekspresikan pada hipotalamus dan berbagai jaringan perifer. Aktivasi jalur ghrelin–reseptor ghrelin diketahui dapat meningkatkan asupan makanan, merangsang sekresi hormon pertumbuhan, memengaruhi sensitivitas insulin, dan berkontribusi terhadap penyimpanan lemak tubuh. Dalam beberapa waktu terakhir, perhatian terhadap peran ghrelin dan reseptornya semakin meningkat karena keterkaitannya dengan obesitas dan sindrom metabolik. Selain regulasi hormonal, faktor genetik juga berkontribusi dalam perkembangan obesitas dan sindrom metabolik. Salah satu faktor genetik yang diteliti adalah single nucleotide polymorphism (SNP) pada gen reseptor ghrelin (GHSR). Variasi genetik tersebut diduga dapat memengaruhi ekspresi maupun fungsi reseptor ghrelin sehingga berdampak pada regulasi nafsu makan, berat badan, resistensi insulin, profil lipid, dan tekanan darah. Beberapa SNP pada gen GHSR telah dilaporkan berhubungan dengan peningkatan indeks massa tubuh, akumulasi lemak viseral, serta risiko sindrom metabolik pada populasi tertentu. Review ini bertujuan untuk membahas ghrelin, reseptor ghrelin, serta SNP reseptor ghrelin pada obesitas dan sindrom metabolik.
Ghrelin is a peptide hormone primarily produced by the stomach and plays an important role in the regulation of energy balance, appetite, glucose metabolism, and lipid homeostasis. The biological effects of ghrelin are mediated through the Growth Hormone Secretagogue Receptor (GHS-R), particularly the GHS-R1a subtype, which is widely expressed in the hypothalamus and various peripheral tissues. Activation of the ghrelin–ghrelin receptor pathway is known to increase food intake, stimulate growth hormone secretion, influence insulin sensitivity, and contribute to body fat storage. In recent years, increasing attention has been directed toward the role of ghrelin and its receptor due to their association with obesity and metabolic syndrome. In addition to hormonal regulation, genetic factors also contribute to the development of obesity and metabolic syndrome. One of the genetic factors that studied is the single nucleotide polymorphism (SNP) in the ghrelin receptor gene (GHSR). These genetic variations are thought to affect the expression and function of the ghrelin receptor, thereby influencing appetite regulation, body weight, insulin resistance, lipid profile, and blood pressure. Several SNPs in the GHSR gene have been reported to be associated with increased body mass index, visceral fat accumulation, and the risk of metabolic syndrome in certain populations. This review aims to discuss ghrelin, ghrelin receptors, and ghrelin receptor SNPs in obesity and metabolic syndrome.
