Inhibition Of Methamphetamine-induced Neurotoxicity And Self-administration By Central Blockade Of The PLCβ1-PKCα-CREB Signaling Pathway In Rats

Objective: Methamphetamine(METH),a potent psychostimulant and neurotoxin,belongs to phenethylamine and amphetamine class of psychoactive drugs.Long-term METH exposure has been shown to produce a wide range of psychological problems,including cognitive impairment,depression,anxiety,and substance use disorders.disease.The present study aimed to investigate the underlying mechanisms of METH-induced neurotoxicity with cognitive deficits.The underlying mechanisms of METH use disorder is still unknown.Currently,there is no effective pharmacological treatment for METH use disorder.We need to further explore the neurobiological mechanism of mental disorders with METH use disorders,and find the potential therapeutic target for METH addition.Our previous studies have showed that angiotensin II receptor subtype 1(AT1R)blockade effectively reduces METH self-administration(SA)and impairments in spatial learning memory.Phospholipase Cβ1(PLCβ1)may play an essential role in METH-induced behavioral disorders during this process.The present study is the first to demonstrate the role of PLCβ1 and its mediated signaling pathways in METH-induced neurotoxicity and METH use disorder.Methods: In Experiments 1,The protein and m RNA expression of PLCβ1 in SH-SY5Y cells and various brain were determined by Western blotting and q RT-PCR.In Experiments 2,Cell apoptosis and reactive oxygen species(ROS)were detected by CCK-8,FDA/PI staining,DCFHDA fluorescent probe and flow cytometry in SH-SY5 Y cell,knock down or knock out PLCβ1 SHSY5Y cell lines respectively.As well as oxidative stress factors in cells were detected by Superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)kits.In Experiments 3,Locomotor activity and METH SA behaviors were tested following administration of PLCβ1 inhibitor,U73122.The protein expression of PLCβ1,protein kinase C α(PKCα)-c AMP response element-binding protein(CREB)in NAc of brain and synaptophysin(SYP),postsynaptic density protein 95(PSD-95)in PFC region of brain were detected by Western blotting.Results: Here,we revealed that repeated METH administration significantly upregulated the expression of PLCβ1 in the PFC and Hip of rats.And compared with the sham operation group,the expression of PLCβ1 was significantly upregulated in the PFC,NAC,VTA and Hip of METH SA rats.The m RNA and protein expression of PLCβ1 increased in a dose-and time-dependent manner in METH treated SH-SY5 Y cells.METH-induced oxidative stress and cell apoptosis was sufficient attenuated by U73122 and in cell lines which knockdown or knockout the PLCβ1.Moreover,PLCβ1,PKCα,and CREB protein expression in METH-exposed SH-SY5 Y cells was significantly recovered by treatment with U73122.METH-triggered hyperlocomotion in rats was significantly attenuated by U73122.Administration of U73122 at 3 or 10 mg/kg significantly affected the response maintained on the FR1 schedule and breakpoints obtained under the PR schedule.Both cue-and drug-induced reinstatement of METH SA were suppressed by 3 and 10mg/kg U73122 administration.METH treatment upregulated the protein expression of PLCβ1,PKCα,and CREB in NAc of rats that self-administered METH under the FR1 schedule.The increase protein expression of SYP and PSD-95 in PFC of brain induced by METH were significantly reduced by U73122.Conclusion: PLCβ1 plays an important role in METH-induced neurotoxicity and selfadministration.The PLCβ1-PKCα-CREB signaling pathway was involved in METH-induced neurotoxicity,cell apoptosis and intracellular oxidative stress level in SH-SY5Y cells.METHinduced self-administration and reinstatement were suppressed by U73122 administration possibly through the PLCβ1-PKCα-CREB signaling pathway in rats.In conclusion,our findings reveal an unappreciated role of the PLCβ1-PKCα-CREB signaling pathway with regard to alleviating a multitude of effects produced by METH.Our data may provide a potential therapeutic target for METH addition.