Role of Cannabinoid CB1 Receptor in Object Recognition Memory Impairment in Chronically Rapid Eye Movement Sleep-deprived Rats

Objective We aimed to investigate whether antagonism of the cannabinoid CB1 receptor(CB1R)could affect novel object recognition(NOR)memory in chronically rapid eye movement sleep-deprived(RSD)rats.Methods The animals were examined for recognition memory following a 7-day chronic partial RSD paradigm using the multiple platform technique.The CB1R antagonist rimonabant(1 or 3 mg/kg,i.p.)was administered either at one hour prior to the sample phase for acquisition,or immediately after the sample phase for consolidation,or at one hour before the test phase for retrieval of NOR memory.For the reconsolidation task,rimonabant was administered immediately after the second sample phase.Results The RSD episode impaired acquisition,consolidation,and retrieval,but it did not affect the reconsolidation of NOR memory.Rimonabant administration did not affect acquisition,consolidation,and reconsolidation;however,it attenuated impairment of the retrieval of NOR memory induced by chronic RSD.Conclusions These findings,along with our previous report,would seem to suggest that RSD may affect different phases of recognition memory based on its duration.Importantly,it seems that the CB1R may,at least in part,be involved in the adverse effects of chronic RSD on the retrieval,but not in the acquisition,consolidation,and reconsolidation,of NOR memory.

利莫那班对肝纤维化C57小鼠肝组织大麻素受体1及α-SMA表达的影响

目的研究大麻素受体1(CB1)拮抗剂利莫那班对肝纤维化模型C57小鼠肝组织中CB1、α-平滑肌肌动蛋白(α-SMA)表达的影响,及其抗肝纤维化的作用机制。方法 30只C57小鼠随机分为3组,分别为正常对照组、模型对照组及利莫那班组,每组10只。采用四氯化碳腹腔注射诱导形成小鼠肝纤维化模型。造模2周后于继续造模同时,正常对照组和模型对照组每天生理盐水灌胃,利莫那班组用利莫那班灌胃。第8周造模结束时处死小鼠,留取肝脏组织标本,分别进行HE和Masson三色染色,应用免疫组织化学方法检测肝组织中CB1和α-SMA的表达,并进行肝组织纤维化评分(S评分)。结果模型对照组和利莫那班组肝组织S评分、CB1和α-SMA阳性表达量均高于正常对照组(均P<0.05),利莫那班组均低于模型对照组(均P<0.05);正常对照组、模型对照组和利莫那班组CB1评分、α-SMA评分与S评分相互之间均呈正相关(均P<0.05)。结论肝组织CB1的激活可促进肝纤维化的形成,CB1拮抗剂利莫那班通过抑制CB1表达,进而抑制肝星状细胞的增殖和激活,从而起到抗肝纤维化的作用。

大麻素受体1拮抗剂ZH-101-S对糖尿病大鼠肾脏的保护作用

目的:探讨新型大麻素受体1拮抗剂ZH-101-S对糖尿病大鼠肾脏的作用及机制。方法:通过腹腔注射链脲佐菌素建立糖尿病大鼠模型,随机分为糖尿病组和低、中、高剂量组,每组6只,低、中、高剂量组分别于每天腹腔注射0.3,1.0,3.0 mg/kg ZH-101-S,另以健康大鼠作为对照组,对照组和糖尿病组腹腔注射等量生理盐水,8周后检测各组大鼠血尿素氮、血肌酐和尿白蛋白排泄率(urine albumin excretion rate,UAER),测定肾组织丙二醛含量和超氧化物歧化酶(SOD)活力,HE染色观察肾组织病理改变,免疫印迹法检测肾组织细胞电压依赖性离子通道(voltage-dependent anion channel,VDAC)蛋白的表达。结果:与对照组比较,糖尿病组大鼠血肌酐、血尿素氮和UAER明显增高;肾组织SOD活性降低,丙二醛含量升高(P<0.05);肾组织细胞VDAC表达明显降低(P<0.01);肾小球体积增大,肾小管上皮细胞水肿,系膜基质增多。与糖尿病组比较,高剂量组大鼠UAER、血肌酐和血尿素氮明显降低;肾组织SOD活性明显升高,丙二醛含量明显降低;肾脏细胞VDAC表达增加(P<0.05);肾组织病理形态得到一定改善。结论:ZH-101-S对糖尿病肾病大鼠肾脏具有保护作用,可能与抑制氧化应激和改善肾脏线粒体功能有关。

Novel Method for Synthesis of Diarylpyrazole Derivatives as Cannabinoid CB_1 Receptor Antagonists

A novel and efficient method was developed for the synthesis of diarylpyrazole derivatives as cannabinoid CB1 receptor antagonist via four step reactions. The key step was the synthesis of a diarylpyrazole skeleton, which involved initial condensation of the sodium salt of compound 12 with diazonium compounds, and further cyclization by heating at reflux in acetic acid. Eight diarylpyrazole derivatives and nine new synthesized compounds were characterized by 1H NMR, IR, MS, and elemental analysis. The reaction conditions were mild and the overall yields of the target compounds ranged from 26% to 44%.

Metabolic and inflammatory functions of cannabinoid receptor type 1 are differentially modulated by adiponectin

BACKGROUND Antagonists of cannabinoid type 1 receptor(CB1)have been shown to promote body weight loss and improve insulin sensitivity.Cannabinoids decrease adiponectin,and CB1 blocker increase adiponectin.However,the mediators of CB1 actions are not well defined.AIM To investigate whether the beneficial effects of CB1 inhibition are,at least in part,mediated by adiponectin.METHODS We compared metabolic and inflammatory phenotypes of wild-type(WT)mice,CB1-null(CB1^(-/-))and CB1/adiponectin double-knockout(DKO)mice.We assessed the insulin sensitivity using insulin tolerance test and glucose tolerance test,and inflammation using flow cytometry analysis of macrophages.RESULTS CB1^(-/-)mice exhibited significantly reduced body weight and fat mass when compared to WT mice.While no significance was found in total daily food intake and locomotor activity,CB1^(-/-)mice showed increased energy expenditure,enhanced thermogenesis in brown adipose tissue(BAT),and improved insulin sensitivity compared to WT mice.DKO showed no difference in body weight,adiposity,nor insulin sensitivity;only showed a modestly elevated thermogenesis in BAT compared to CB1^(-/-)mice.The metabolic phenotype of DKO is largely similar to CB1^(-/-)mice,suggesting that adiponectin is not a key mediator of the metabolic effects of CB1.Interestingly,CB1^(-/-)mice showed reduced pro-inflammatory macrophage polarization in both peritoneal macrophages and adipose tissue macrophages compared to WT mice;in contrast,DKO mice exhibited increased pro-inflammatory macrophage polarization in these macrophages compared to CB1^(-/-)mice,suggesting that adiponectin is an important mediator of the inflammatory effect of CB1.CONCLUSION Our findings reveal that CB1 functions through both adiponectin-dependent and adiponectin-independent mechanisms:CB1 regulates energy metabolism in an adiponectin-independent manner,and inflammation in an adiponectin-dependent manner.The differential effects of adiponectin on CB1-mediated metabolic and inflammatory functions should be taken into consideration in CB1 antagonist utilization.

Signal Peptide and Denaturing Temperature are Critical Factors for Efficient Mammalian Expression and Immunoblotting of Cannabinoid Receptors

Many researchers employed mammalian expression system to artificially express cannabinoid receptors, but immunoblot data that directly prove efficient protein expression can hardly be seen in related research reports. In present study, we demonstrated cannabinoid receptor protein was not able to be properly expressed with routine mammalian expression system. This inefficient expression was rescued by endowing an exogenous signal peptide ahead of cannabinoid receptor peptide. In addition, the artificially synthesized cannabinoid receptor was found to aggregate under routine sample denaturing temperatures (i.e.,≥95°C), forming a large molecular weight band when analyzed by immuno-blotting. Only denaturing temperatures ≤75°C yielded a clear band at the predicted molecular weight. Collectively, we showed that efficient mammalian expression of cannabinoid receptors need a signal peptide sequence, and described the requirement for a low sample denaturing temperature in immuno-blot analysis. These findings provide very useful information for efficient mammalian expression and immuno-blotting of membrane receptors.

AB059.Expression patterns of CB1R,NAPE-PLD,and FAAH in the primary visual cortex of vervet monkeys

Background:The expression,localization,and function of the endocannabinoid system has been well characterized in recent years in the monkey retina and in the primary thalamic relay,the lateral geniculate nucleus(dLGN).Few data are available on cortical recipients’structures of the dLGN,namely the primary visual cortex(V1).The goal of this study is to characterize the expression and localization of the metabotropic cannabinoid receptor type 1(CB1R),the synthesizing enzyme N-acyl phosphatidyl-ethanolamine phospholipase D(NAPE-PLD),and the degradation enzyme fatty acid amide hydrolase(FAAH)in the vervet monkey area V1.Methods:Using Western blots and immunohistochemistry,we investigated the expression patterns of CB1R,NAPE-PLD,and FAAH in the vervet monkey primary visual cortex.Results:CB1R,NAPE-PLD,and FAAH were expressed in the primary visual cortex throughout the rostro-caudal axis.CB1R showed very low levels of staining in cortical layer 4,with higher expressions in all other cortical layers,especially layer 1.NAPE-PLD and FAAH expressions were highest in layers 1,2 and 3,and lowest in layer 4.Conclusions:Interestingly enough,CB1R was very low in layer 4 of V1 in comparison to the other cortical layers.The visual information coming from the dLGN and entering layer 4Calpha(magno cells)and 4Cbeta(parvo cells)may be therefore modulated by the higher expression levels of CB1R in cortical layers 2 and 3 on the way to the dorsal and ventral visual streams.This is further supported by the higher expression of NAPE-PLD and FAAH in the outer cortical layers.These data indicate that CB1R system can influence the network of activity patterns in the visual stream after the visual information has reached area V1.These novel results provide insights for understanding the role of the endocannabinoids in the modulation of cortical visual inputs,and hence,visual perception.

AB007. Expression and localization of CB1R,NAPE-PLD,and FAAH in the primary visual cortex of vervet monkeys

Background:The goal of this study is to determine the expression and localization of the cannabinoid receptor type 1(CB1R),the synthesizing enzyme N-acyl phosphatidyl-ethanolamine phospholipase D(NAPE-PLD),and the degradation enzyme fatty acid amide hydrolase(FAAH)in the vervet monkey area V1 to better understand the mechanisms underlying the effects of eCB system modulation on cortical visual processing.Methods:Using Western blots and immunohistochemistry,we investigated the laminar and cellular expression patterns of CB1R,NAPE-PLD,and FAAH across the rostrocaudal axis of the vervet monkey(Chlorocebus sabaeus)primary visual cortex.Results:CB1R,NAPE-PLD,and FAAH were expressed in V1 throughout the rostrocaudal axis.CB1R showed very low staining in layer(L)4,with higher expression in all other layers,especially L1,followed by L2 and L3.NAPE-PLD and FAAH expression patterns were similar,but not quite as low in L4.CB1R,NAPE-PLD,and FAAH were localized in vGlut2-positive cells,representing glutamatergic projection neurons,and in somatostatin(SST)-positive cells,a class of GABAergic interneurons.Conclusions:The low level of CB1R in L4 indicates less direct endocannabinoid modulation of V1 afferents from the dLGN,but that greater modulation may occur via the higher expression of CB1R in L2 and L3 on the way to the dorsal and ventral visual streams.This is further supported by the higher expression of NAPE-PLD and FAAH in these layers.Expression in vGlut2-positive and SST-positive cells represents a role at both glutamatergic and GABAergic neurons.These data indicate that CB1R may influence the network of activity patterns in the visual streams after the visual information has reached V1,and thus may influence visual perception.

Induction of Anxiety-Like Phenotypes by Knockdown of Cannabinoid Type-1 Receptors in the Amygdala of Marmosets

The amygdala is an important hub for regulating emotions and is involved in the pathophysiology of many mental diseases,such as depression and anxiety.Meanwhile,the endocannabinoid system plays a crucial role in regulating emotions and mainly functions through the cannabinoid type-1 receptor(CB1R),which is strongly expressed in the amygdala of non-human primates(NHPs).However,it remains largely unknown how the CB1Rs in the amygdala of NHPs regulate mental diseases.Here,we investigated the role of CB1R by knocking down the cannabinoid receptor 1(CNR1)gene encoding CB1R in the amygdala of adult marmosets through regional delivery of AAV-SaCas9-gRNA.We found that CB1R knockdown in the amygdala induced anxiety-like behaviors,including disrupted night sleep,agitated psychomotor activity in new environments,and reduced social desire.Moreover,marmosets with CB1R-knockdown had up-regulated plasma cortisol levels.These results indicate that the knockdown of CB1Rs in the amygdala induces anxiety-like behaviors in marmosets,and this may be the mechanism underlying the regulation of anxiety by CB1Rs in the amygdala of NHPs.

Activation of Cannabinoid Receptor 1 in GABAergic Neurons in the Rostral Anterior Insular Cortex Contributes to the Analgesia Following Common Peroneal Nerve Ligation

The rostral agranular insular cortex(RAIC)has been associated with pain modulation.Although the endogenous cannabinoid system(eCB)has been shown to regulate chronic pain,the roles of eCBs in the RAIC remain elusive under the neuropathic pain state.Neuropathic pain was induced in C57BL/6 mice by common peroneal nerve(CPN)ligation.The roles of the eCB were tested in the RAIC of ligated CPN C57BL/6J mice,glutamatergic,or GABAergic neuron cannabinoid receptor 1(CB1R)knockdown mice with the whole-cell patch-clamp and pain behavioral methods.The E/I ratio(amplitude ratio between mEPSCs and mIPSCs)was significantly increased in layer V pyramidal neurons of the RAIC in CPN-ligated mice.Depolarization-induced suppression of inhibition but not depolarization-induced suppression of excitation in RAIC layer V pyramidal neurons were significantly increased in CPN-ligated mice.The analgesic effect of ACEA(a CB1R agonist)was alleviated along with bilateral dorsolateral funiculus lesions,with the administration of AM251(a CB1R antagonist),and in CB1R knockdown mice in GABAergic neurons,but not glutamatergic neurons of the RAIC.Our results suggest that CB1R activation reinforces the function of the descending pain inhibitory pathway via reducing the inhibition of glutamatergic layer V neurons by GABAergic neurons in the RAIC to induce an analgesic effect in neuropathic pain.

The endocannabinoid system:A new pharmacological target for obesity treatment?

Being a great threaten for human health, obesity has become a pandemic chronic disease. There have been several therapeutic treatments for this social health issue, including diet and exercise therapy, medication and surgery, among which the diet is still the most common way. However, none of these therapeutic measures available is ideal, making it necessary to find an effective medical treatment. The endocannabinoid system, which is well known for its contributions in certain mental processes such as relaxation, amelioration of pain and anxiety, and sedation initiation, has been recently reported to play an essential role in regulating appetite and metabolism to maintain energy balance, leading to the belief that endocannabinoid system is closely related to obesity. This new discovery deepens our understanding of obesity, and provides us with a new direction for clinical obesity treatment. Rimonabant is an antagonist for CB1, and has entered the market in some countries. However, although effective as an anti-obesity drug, rimonabant also causes obviously adverse side-effects, thus is being doubted and denied for medical usage.

CB 1 cannabinoid receptor participates in the vascular hyporeactivity resulting from hemorrhagic shock in rats

Background Vascular hyporeactivity, which occurs in the terminal stage of hemorrhagic shock, is believed to be critical for treating hemorrhagic shock. The present study was designed to examine whether the CB1 cannabinoid receptor （CB1 R） was involved in the development of vascular hyporeactivity in rats suffering from hemorrhagic shock. Methods Sixteen animals were randomly divided into two groups （n=8 in each group）： sham-operated （Sham） and hemorrhagic shock （HS） groups. Hemorrhagic shock was induced by bleeding. The mean arterial pressure （MAP） was reduced to and stabilized at （25±5） mmHg for 2 hours. The vascular reactivity was determined by the response of MAP to norepinephrine （NE）. In later experiments another twelve animals were used in which the changes of CB1R mRNA and protein in aorta and superior mesenteric artery （SMA） were analyzed by RT-PCR and Western blotting. In addition, we investigated the effects of a CB1R antagonist on the vascular hyporeactivity and survival rates in rats with hemorrhagic shock. Survival rates were analyzed by the Fisher＇s exact probability test. The MAP response was analyzed by one-way analysis of variance （ANOVA）. Results Vascular hyporeactivity developed in all animals suffering from hemorrhagic shock. The expression of CBIR mRNA and protein in aorta and 2-3 branches of the SMA were significantly increased in the HS group after the development of vascular hyporeactivity when compared to those in Sham group. When SR141716A or AM251 was administered, the MAP response to NE was （41.75±4.08） mmHg or （44.78±1.80） mmHg respectively, which was higher than that in saline groups with （4.31±0.36） mmHg （P 〈0.01）. We also showed an increased 4-hour survival rate in the SR141716A or AM251-treated group with 20% or 30%, but with a statistically significant difference present between the AM251-treated and saline groups （P 〈0.05）. Conclusions CBIR is involved in vascular hyporeactivity resulting from hemorrhagic shock in rats, and CB1R antagonist may be useful in treating patients with traumatic, hemorrhagic shock who need field-rescue or initial treatment.