HS014 TFA is a potent and selective melanocortin MC4 receptor antagonist (Ki=3.16nM). HS014 TFA regulates appetite and energy balance by blocking the interaction between the MC4 receptor and endogenous ligands, while also reducing inflammatory responses by inhibiting IL-1β-induced Fos expression[1-2]. HS014 TFA is utilized in research related to obesity, diabetes, and metabolic syndrome[3-4].
In vitro, epidermal melanocytes were pretreated with HS014 TFA (10nM–200nM) for 30 minutes, followed by stimulation with β-MSH (200nM) or the N-terminally modified α-MSH analog NDP-α-MSH (200nM) for 72 hours. HS014 TFA significantly inhibited melanin formation and reduced cAMP production[5]. MC4R-overexpressing M1830 astrocytoma cells were treated with HS014 TFA (1nM) for 12 days. This treatment significantly downregulated the expression of p-JNK, ATF3, and c-Jun proteins, while also suppressing the activation of the JNK signaling pathway[6].
In vivo, HS014 TFA (1μg; 5μl) was administered via a single intracerebroventricular (icv) injection in rats that had been previously induced with fever by lipopolysaccharide (LPS; 30μg/kg; i.p.). HS014 TFA had no significant effect on the febrile response but completely blocked the antipyretic effect produced by the selective MC4R agonist MRLOB-0001 (150ng; icv)[7]. HS014 TFA (3.5ng or 100μg, intranasal infusion) was administered as a single dose 30 minutes before a single prolonged stress (SPS) exposure in rats. The 100μg dose significantly reduced the elevation in plasma corticosterone levels measured 30 minutes after the SPS stressor ended, while both doses prevented the stress-induced short-term increase in corticotropin-releasing hormone (CRH) mRNA levels in the basal medial hypothalamus, as well as the increase in tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH) mRNA levels in the locus coeruleus[8].
References:
[1] Schiöth HB, Mutulis F, Muceniece R, et al. Discovery of novel melanocortin4 receptor selective MSH analogues. Br J Pharmacol. 1998 May;124(1):75-82.
[2] Ercil NE, Galici R, Kesterson RA. HS014, a selective melanocortin-4 (MC4) receptor antagonist, modulates the behavioral effects of morphine in mice. Psychopharmacology (Berl). 2005 Jul;180(2):279-85.
[3] Kask A, Rägo L, Mutulis F, et al. Selective antagonist for the melanocortin 4 receptor (HS014) increases food intake in free-feeding rats. Biochem Biophys Res Commun. 1998 Apr 7;245(1):90-3.
[4] Gao Z, Lei D, Welch J, et al. Agonist-dependent internalization of the human melanocortin-4 receptors in human embryonic kidney 293 cells. J Pharmacol Exp Ther. 2003 Dec;307(3):870-7.
[5] Spencer JD, Schallreuter KU. Regulation of pigmentation in human epidermal melanocytes by functional high-affinity beta-melanocyte-stimulating hormone/melanocortin-4 receptor signaling. Endocrinology. 2009 Mar;150(3):1250-8.
[6] Zhao Y, Xin Y, Chu H. MC4R Is Involved in Neuropathic Pain by Regulating JNK Signaling Pathway After Chronic Constriction Injury. Front Neurosci. 2019 Sep 10;13:919.
[7] Loopuijt LD. Local application of L- threo-hydroxyaspartate and malonate in rats in vivo induces rigidity and damages neurons of the substantia nigra, pars compacta. J Neural Transm (Vienna). 2002 Oct;109(10):1275-94.
[8] Serova LI, Laukova M, Alaluf LG, et al, Blockage of melanocortin-4 receptors by intranasal HS014 attenuates single prolonged stress-triggered changes in several brain regions. J Neurochem. 2014 Dec;131(6):825-35.