Antidepressant-like Effect And Mechanisms Of Hypidone Hydrochloride (YL-0919)

Depression is a mental illness which has highest morbidity and disability.Because of its high morbidity, high suicide, high recurrence, high disability and lowrecognition,low response, low treatment rates, depression becomes a serious globalpublic health issues and highlight social problems.WHO predicts that by2020,depression will become the second largest hazard to human health.Currently, thefirst-line clinical antidepressant drugs most widely used, including5-HT reuptakeinhibitors (SSRIs, such as fluoxetine),5-HT/NE dual reuptake inhibitors (SNRIs, suchas duloxetine), etc, have many shortages including onset latency, low efficiency andsevere side effects (such as sexual dysfunction and suicidal tendencies).In recent years,based on the "monoamine optimization strategy”,novel serotonin partial agonist andreuptake inhibitors(SPARIs), have become the representative direction of the newdrugs development for its advantage of potent, rapid onset, low suicidal rate of andlow adverse reactions (including sexual dysfunction and weight gain).Hypidone hydrochloride (YL-0919) is a novel patented SPARIs antidepressantdeveloped by Institute of Pharmacology and Toxicology, Academy of MilitaryMedical Science. It has strong prospects for drug development.This study aimed toinvestigate the behavior activity and its target mechanisms.Objective: To explore the antidepression effect and targeting mechanism of YL-0919,a new antidepressant with dual the5-HT1Areceptor agonist and serotonin transporterinhibitor.Methods: Radioligand receptorbinding assays were used to study the affinity andreceptor selectivity of YL-0919to5-HT transporter (SERT) and5-HT1Areceptor inrat brain synaptosomes protein.We further prepared rat synaptosomes protein withSERT and HEK-293cell lines expressing human SERT (hSERT) to study the5-HTreuptake inhibitioneffect of YL-0919.We evaluate the acute antidepressant-like activity of YL-0919in two classicbehavioral despair models, mouse tail suspensiontest (TST) and forced swimming test(FST) respectively. Based on the literature, we combined applicated YL-0919withdepression-related receptor blockade agent to confirm related receptor of YL-0919’s antidepressant-like effects. We evaluated antidepressant-like activity ofsub-chronicYL-0919treatment on learned helplessness model in mice, anxiolyticactivityof chronic YL-0919treatment in rats elevated-zeromazetest, elevated-plusmazetest,Vogel’sconflict test, novelty-suppressed feeding test. The antidepressant-likeand anxiolytic effects of YL-0919and vilazodone were compared during chronictreatment using novelty-suppressed feeding test, TST and FST.In vitro, we detected the affection of YL-0919to the level of AC activity insynaptic membrane of normal rat prefrontal cortex by the homogeneous time-resolvedfluorescence resonance energy transfer (TR-FRET) immunoassay, while we observedthe effects with5-HT1Areceptor antagonist WAY-100635. The AC activity changes inprefrontal cortex and mouse hippocampus were detected after the long-termadministration. PKA activity in the hippocampus of mice was observed usingenzyme-linked immunosorbent assay (ELISA) test after long-term administration.Mouse tail suspension and forced swimming models were used after Intraventricularinjection blocker H-89(PKA inhibitor) to observe the blocking effect toantidepressant-like activity of YL-0919. We studied BDNF, p-CREB, p-ERKexpression in mouse hippocampal after chronic administration using Western blotanalysis (Western Blot).Results: YL-0919had high affinity to both SERT and5-HT1Areceptor with Kiof0.72nM and0.19nM respectively, and low affinityto NET (NE transporter) and DAT (DAtransporter). YL-0919potently inhibited [3H]-5-HT reuptakein the rat prefrontalcortex crude synaptosomes and HEK-293cell lines expressing human SERT, withIC50of1.78nand1.93nMrespectively. YL-0919had low affinity to19kinds ofreceptors (D3, D2, D4, D1, D5,5-HT1B,5-HT1D,5-HT2A,5-HT2C,5-HT5A,5-HT6, α1A, α1B,α2A, M1, M2, M3, M4, M5) at a concentration of10μM, suggesting that YL-0919binding5-HT1Areceptor and SERT with high selectivity.Single oral treatment with YL-09190.625-2.5mg/kg, i.g significantly reducedthe immobility time in a dose-dependent manner in both the mouse tail suspensiontest and forcedswimming test and5-HT1Areceptor antagonist WAY-100635cancompletely block the antidepressant-like activity of YL-09192.5mg/kg, i.g. The5-HT2receptor antagonist mianserin,5-HT3receptor antagonist tropisetron, α2adrenoceptor antagonist yohimbine showed non-blocking effects on theantidepressant-like activity of YL-0919. It poited YL-0919exertedantidepressant-likeeffect afer acute administration and5-HT1Areceptor activation might be underlying the antidepressant effect of it. YL-09191.25-5mg/kg, i.g significantly shortened theescape latency and reduce the number of escape failureduring sub-chronicadministration (day2-5) in learned helplessnessmodel, showing antidepressantactivity. Chronic YL-09190.625-2.5mg/kg, i.g treatment significantly reduced therats’latency to feeding in the novelty-suppressed feeding test, increased theopen armsentries and time spent in open arms in the zero-maze test,significantly increased thepercentage of open arms entries and time spent in open arms in the elevated-plusmaze test, increased the number of shock drinking water, suggesting anxiolytic effects.YL-09190.625-2.5mg/kg, i.g. and vilazodone1-4mg/kg, i.g. both reduced thelatency to feeding in the novelty-suppressed feeding test afer administration for twoweeks, significantlyreduce the immobility time in tail suspension and swimmingtest,indicated that YL-0919and vilazodone exerted antidepressant-like and anxiolyticactivity equivalently,moreover the effective dose of YL-0919was smaller thanvilazodone.YL-0919(10-9-10-5mol/L)significantly increased AC activity in prefrontalcortical synaptic membrane of normal rats;5-HT1Areceptor antagonist WAY-100635significantly antagonized the effect. Chronic YL-09191.25-2.5mg/kg, i.g. andvilazodone4mg/kg, i.g. administration can enhance the AC activity in mousehippocampus, prefrontal cortex, significantly increased BDNF, p-CREB, p-ERKexpression in mouse hippocampal, enhanced PKA activity in mouse hippocampal.Intraventricular injection of PKA inhibitor H-89blocked the antidepressant-likeactivity of YL-09192.5mg/kg, i.g. in the mouse tail suspension and forced swimmodels.Conclusion: YL-0919had high affinity to SERT and5-HT1Areceptor selectivity,exerted a strong5-HT reuptake inhibiting function. YL-0919showedantidepressant-like effect afer acute administration and5-HT1Areceptor activationmight be underlying the antidepressant effect of it. Sub-chronic, chronic YL-0919administration showed significant antidepressant-like, anxiolytic effects in variouskinds of animal models. YL-0919and vilazodone exerted antidepressant-like andanxiolytic activity equivalently, moreover the effective dose of YL-0919was smallerthan vilazodone.5-HT1Areceptor activation, the prefrontal cortex, hippocampusAC-cAMP-PKA signaling pathway enhancementand upregulation of hippocampalBDNF signaling pathway to promote neurotrophic effects might be underlying theantidepressant effect of YL-0919.