Are TrkB receptor agonists the right tool to fulfill the promises for a therapeutic value of the brain-derived neurotrophic factor?

Brain-derived neurotrophic factor signaling via its receptor tro pomyosin receptor kinase B regulates several crucial physiological processes.It has been shown to act in the brain,promoting neuronal survival,growth,and plasticity as well as in the rest of the body where it is involved in regulating for instance aspects of the metabolism.Due to its crucial and very pleiotro pic activity,reduction of brain-derived neurotrophic factor levels and alterations in the brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling have been found to be associated with a wide spectrum of neurological diseases.Howeve r,because of its poor bioavailability and pharmacological properties,brain-derived neurotrophic factor itself has a very low therapeutic value.Moreover,the concomitant binding of exogenous brain-derived neurotrophic factor to the p75 neurotrophin receptor has the potential to elicit several unwanted and deleterious side effects.Therefo re,developing tools and approaches to specifically promote tropomyosin receptor kinase B signaling has become an important goal of translational research.Among the newly developed tools are different categories of tropomyosin receptor kinase B receptor agonist molecules.In this review,we give a comprehensive description of the diffe rent tro pomyosin receptor kinase B receptor agonist drugs developed so far and of the res ults of their application in animal models of several neurological diseases.Moreover,we discuss the main benefits of tropomyosin receptor kinase B receptor agonists,concentrating especially on the new tropomyosin receptor kinase B agonist antibodies.The benefits observed both in vitro and in vivo upon application of tropomyosin receptor kinase B receptor agonist drugs seem to predominantly depend on their general neuroprotective activity and their ability to promote neuronal plasticity.Moreover,tro pomyosin receptor kinase B agonist antibodies have been shown to specifically bind the tropomyosin receptor kinase B receptor and not p75 neurotrophin receptor.Therefore,while,based on the current knowledge,the tropomyosin receptor kinase B receptor agonists do not seem to have the potential to reve rse the disease pathology per se,promoting brainderived neurotrophic factor/tro pomyosin receptor kinase B signaling still has a very high therapeutic relevance.

D₁and TrkB Receptors Take Charge of the Molecular Antidepressant Action in Cultured Astroglial Cells

In psychopharmacology of depression, we observe two ways of research. One group is focused on catecholamines action. Second one fixes attention on neuronal morphogenesis and synaptic plasticity. The intimate connection of astrocytes, neurons and synaptic endings determines glial participation in neural homeostasis. Consequently this situation enlarges the role of astrocytes in the CNS synaptic plasticity. Brain Derived Neurotrophic factor and its receptor TrkB suppose to coordinate both of the above mentioning signaling pathways in depression disturbances. In our experiment, we have exploited striatal tissue because in our opinion this structure is misjudged in pathophysiology of depression alas;Several hypothesis proposed striatum as important in future intention activity structure. RT-PCR analysis was used to determine D1, BDNF and TrkB mRNA expression in cultured striatal astroglial cells. Administration of three representative antidepressants (ADs) like amitriptyline, moclobemide and sertraline to astroglial culture medium increase the D1, BDNF/TrkB mRNA expression. Our previous study showed that the stimulation of cAMP to CREB pathway after D1 receptors excitation constituted a common response to ADs. The present results signify that D1, BDNF/TrkB link which is next neural track (after cAMP/PKA) involved in the CNS adaptation to external conditions altered by chronic ADs treatment. Moreover, the striatum tissue appears to be important formation which takes an active part in antidepressant action thus essential in depression disorder etiology.

Effects of senescence on the expression of BDNF and TrkB receptor in the lateral geniculate nucleus of cats

To explore the neural mechanisms mediating agingrelated visual function declines, we compared the expressions of brain-derived neurotrophic factor（BDNF） and its high affinity receptor-tyrosine kinase B（Trk B） between young and old adult cats. Nissl staining was used to display neurons in each layer of the lateral geniculate nucleus（LGN）. The BDNF- and Trk B receptor-immunoreactive neurons were labeled immunohistochemically, observed under optical microscope and photographed. Their neuronal density and immunoreactive intensity were measured. Results showed that the mean density of the Nissl stained neurons in each LGN layer were comparable between old and young adult cats, and their BDNF and Trk B proteins were widely expressed in all LGN layers. However, compared with young adult cats, both the density and optical absorbance intensity of BDNF- and Trk B-immunoreactive cells in each LGN layer in old cats were significantly decreased. These findings indicate that the decreased expressions of BDNF and Trk B proteins in the LGN may be an important factor inducing the compromised inhibition in the central visual nucleus and the functional visual decline in senescent individuals.

P2Y1 receptor in Alzheimer’s disease

Alzheimer’s disease is the most frequent form of dementia characterized by the deposition of amyloid-beta plaques and neurofibrillary tangles consisting of hyperphosphorylated tau.Targeting amyloid-beta plaques has been a primary direction for developing Alzheimer’s disease treatments in the last decades.However,existing drugs targeting amyloid-beta plaques have not fully yielded the expected results in the clinic,necessitating the exploration of alternative therapeutic strategies.Increasing evidence unravels that astrocyte morphology and function alter in the brain of Alzheimer’s disease patients,with dysregulated astrocytic purinergic receptors,particularly the P2Y1 receptor,all of which constitute the pathophysiology of Alzheimer’s disease.These receptors are not only crucial for maintaining normal astrocyte function but are also highly implicated in neuroinflammation in Alzheimer’s disease.This review delves into recent insights into the association between P2Y1 receptor and Alzheimer’s disease to underscore the potential neuroprotective role of P2Y1 receptor in Alzheimer’s disease by mitigating neuroinflammation,thus offering promising avenues for developing drugs for Alzheimer’s disease and potentially contributing to the development of more effective treatments.

Melanocortin 3,5 receptors immunohistochemical expression in colonic mucosa of inflammatory bowel disease patients:A matter of disease activity?

BACKGROUND Melanocortin 3 and 5 receptors(i.e.,MC3R and MC5R)belong to the melanocortin family.However,data regarding their role in inflammatory bowel diseases(IBD)are currently unavailable.AIM This study aims to ascertain their expression profiles in the colonic mucosa of Crohn’s disease(CD)and ulcerative colitis(UC),aligning them with IBD disease endoscopic and histologic activity.METHODS Colonic mucosal biopsies from CD/UC patients were sampled,and immunohisto-chemical analyses were conducted to evaluate the expression of MC3R and MC5R.Colonic sampling was performed on both traits with endoscopic scores(Mayo endoscopic score and CD endoscopic index of severity)consistent with inflamed mucosa and not consistent with disease activity(i.e.,normal appearing mucosa).RESULTS In both CD and UC inflamed mucosa,MC3R(CD:+7.7 fold vs normal mucosa,P<0.01;UC:+12 fold vs normal mucosa,P<0.01)and MC5R(CD:+5.5 fold vs normal mucosa,P<0.01;UC:+8.1 fold vs normal mucosa,P<0.01)were significantly more expressed compared to normal mucosa.CONCLUSION MC3R and MC5R are expressed in the colon of IBD patients.Furthermore,expression may differ according to disease endoscopic activity,with a higher degree of expression in the traits affected by disease activity in both CD and UC,suggesting a potential use of these receptors in IBD pharmacology.

Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome

BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain conditions.The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea(IBS-D)was investigated in the present study.AIM To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with IBS-D.METHODS Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy controls.The expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain scores.The IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap restraint.Alterations in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1(TRPV1)expression were examined following 5-HT2B receptor antagonist adminis-tration.Changes in visceral sensitivity after administration of the TRPV1 antago-INTRODUCTION Irritable bowel syndrome(IBS)is a chronic functional bowel disorder characterized by recurrent abdominal pain with altered bowel habits that affects approximately 15%of the population worldwide[1].IBS significantly impacts the quality of life of patients.Although the pathogenesis of IBS is not completely understood,the role of abnormal visceral sensitivity in IBS has recently emerged[2,3].5-Hydroxytryptamine(5-HT)is known to play a key role in the physiological states of the gastrointestinal tract.Plasma 5-HT levels in IBS with diarrhea(IBS-D)patients were greater than those in healthy controls[4],suggesting a possible role of 5-HT in the pathogenesis of IBS-D.The serotonin receptor 2(5-HT2 receptor)family comprises three subtypes:5-HT2A,5-HT2B,and 5-HT2c.All 5-HT2 receptors exhibit 46%-50%overall sequence identity,and all of these receptors preferentially bind to Gq/11 to increase inositol phosphates and intracellular calcium mobilization[5].5-HT2B receptors are widely expressed throughout the gut,and experimental evidence suggests that the primary function of 5-HT2B receptors is to mediate contractile responses to 5-HT through its action on smooth muscle[6].The 5-HT2B receptor is localized to both neurons of the myenteric nerve plexus and smooth muscle in the human colon.The 5-HT2B receptor mediates 5-HT-evoked contraction of longitudinal smooth muscle[6].These findings suggest that the 5-HT2B receptor could play an important role in modulating colonic motility,which could affect sensory signaling in the gut.Other laboratories have shown that the 5-HT2B receptor participates in the development of mechanical and formalin-induced hyperalgesia[7,8].A 5-HT2B receptor antagonist reduced 2,4,6-trinitrobenzene sulfonic acid(TNBS)and stress-induced visceral hyperalgesia in rats[9,10].However,the role of the 5-HT2B receptor in IBS-D patients and in acetic acid-and wrap restraint-induced IBS-D rat models was not investigated.

Axonal growth inhibitors and their receptors in spinal cord injury:from biology to clinical translation

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2DM.Various considerations can make selecting and switching between different GLP-1 RAs challenging.Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

癫痫持续状态大鼠血清与海马TrkB及BDNF动态变化情况与分析

分析癫痫持续状态大鼠血清、海马TrkB变化情况及脑源性神经营养因子(BDNF)变化情况。方法 以成年雄性SD大鼠48只为研究对象并分为两组,以氯化锂-匹罗卡品及腹腔注射的方式将癫痫持续状态组大鼠制作成大鼠癫痫持续状态模型,给予对照组大鼠生理盐水腹腔注射,对比各组大鼠致痫24h后、致痫30d后BDNF mRNA表达水平及致痫30d后TrkB表达水平,分析各组大鼠海马BDNF及TrkB免疫组化染色结果。结果 两组比较,大鼠致痫24h后癫痫持续状态组大鼠具有更高的BDNF mRNA表达水平(P<0.05),致痫30d后BDNF mRNA大鼠表达水平无显著差异(P>0.05)。两组比较,大鼠致痫24h后癫痫持续状态组大鼠具有更高的TrkB表达水平(P<0.05),致痫30d后大鼠TrkB表达水平组间对比不显著(P>0.05)。结论 癫痫持续状态大鼠血清与海马TrkB与BDNF致痫24h后表达水平较低,致痫30d后表达水平明显升高。

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.

温和灸对寒湿凝滞型原发性痛经大鼠下丘脑BDNF/TrkB信号通路蛋白表达的影响

目的观察温和灸对寒湿凝滞型原发性痛经(PD)大鼠的镇痛效果及对下丘脑BDNF/TrkB信号通路蛋白表达的影响,探讨其治疗痛经的作用机制。方法将32只Wistar雌性未孕大鼠随机分为空白组、模型组、西药组和温和灸组,每组8只。除空白组外,其余组采用苯甲酸雌二醇腹腔注射联合冰水浴+缩宫素腹腔注射建立寒湿凝滞型PD大鼠模型,造模第8日起,温和灸组选取“神阙”“关元”温和灸10 min,西药组予布洛芬溶液灌胃,连续4 d。观察大鼠扭体潜伏期并计算扭体评分,Western blot和PCR检测下丘脑组织c-fos、脑源性神经营养因子(BDNF)、酪氨酸激酶受体B(TrkB)蛋白及mRNA表达。结果与空白组比较,模型组大鼠扭体潜伏期缩短、扭体评分增加(P<0.01),下丘脑组织c-fos、BDNF、TrkB蛋白和mRNA表达升高(P<0.01,P<0.05);与模型组比较,温和灸组大鼠扭体潜伏期延长、扭体评分降低(P<0.01),下丘脑组织c-fos、BDNF、TrkB蛋白和mRNA表达升高(P<0.01,P<0.05)。结论温和灸可有效改善寒湿凝滞型PD大鼠疼痛状态,其机制可能与下调c-fos表达、抑制BDNF/TrkB信号通路激活,从而抑制疼痛信号传递,调节疼痛发生和维持有关。

Activation of G-protein-coupled receptor 39 reduces neuropathic pain in a rat model

Activated G-protein-coupled receptor 39(GPR39)has been shown to attenuate inflammation by interacting with sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α).However,whether GPR39 attenuates neuropathic pain remains unclear.In this study,we established a Sprague-Dawley rat model of spared nerve injury-induced neuropathic pain and found that GPR39 expression was significantly decreased in neurons and microglia in the spinal dorsal horn compared with sham-operated rats.Intrathecal injection of TC-G 1008,a specific agonist of GPR39,significantly alleviated mechanical allodynia in the rats with spared nerve injury,improved spinal cord mitochondrial biogenesis,and alleviated neuroinflammation.These changes were abolished by GPR39 small interfering RNA(siRNA),Ex-527(SIRT1 inhibitor),and PGC-1αsiRNA.Taken together,these findings show that GPR39 activation ameliorates mechanical allodynia by activating the SIRT1/PGC-1αpathway in rats with spared nerve injury.

针刺调节BDNF/TrkB信号通路改善中枢神经系统疾病的研究进展

BDNF/TrkB信号通路作为神经元生长、发育和突触可塑性的关键调节器,广泛参与中枢神经系统疾病的发生发展,如缺血性脑卒中、阿尔茨海默病、帕金森病和脊髓损伤等。研究表明针刺能调节BDNF/TrkB信号通路的活性,对以上疾病具有显著的治疗潜力,其作用机制与参与突触结构重塑,抑制神经细胞凋亡,促进神经发生和突触再生等有关。本文综述了BDNF/TrkB相关信号通路在中枢神经系统疾病中的作用以及针刺对该通路的调控机制,以期为临床治疗提供新思路。未来研究应深入探究针刺对BDNF/TrkB信号通路的精准调控,以开发更高效安全的治疗策略。

基于BDNF/TrkB通路探讨清心开窍方对APP/PS1双转基因小鼠学习记忆能力的影响

目的 基于脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)/原肌球蛋白相关激酶B(Tropomyosin-related kinase B,TrkB)通路探讨清心开窍方对淀粉样前体蛋白/早老素-1(APP/PS1)双转基因小鼠认知功能及神经元保护作用的影响。方法 将30只APP/PS1小鼠按照随机数字表法分为模型组、安理申组(1.67 mg·kg^(-1)·d^(-1))、清心开窍方低剂量组(4.75 mg·kg^(-1)·d^(-1))、清心开窍方中剂量组(9.5 mg·kg^(-1)·d^(-1))和清心开窍方高剂量组(19 mg·kg^(-1)·d^(-1))。选取6只雄性C57/B6小鼠记为对照组,连续90 d于每日上午9点进行灌胃。完成灌胃后,通过Morris水迷宫测试小鼠的空间学习记忆能力;通过HE染色观察小鼠海马CA1区细胞形态变化;通过尼氏染色观察小鼠海马CA1区病理形态变化;通过实时荧光定量聚合酶链式反应(Real-time PCR)检测β位淀粉样前体蛋白裂解酶1(BACE1)、TrkB、BDNF mRNA在小鼠海马中的表达;通过蛋白免疫印迹法(Western blotting, WB)检测P-TrkB、TrkB、BACE1、BDNF蛋白的表达水平。结果 与对照组相比,模型组小鼠逃避潜伏期明显增多(P<0.01),而穿越平台次数以及在原平台所在象限滞留的时间明显增多(P<0.01),其小鼠海马神经元出现严重损伤,排列松散,尼氏体数量减少,染色变浅,BACE1表达增加(P<0.01),P-TrkB、TrkB、BDNF表达降低(P<0.01);与模型组相比,清心开窍方治疗组逃避潜伏期缩短,穿越平台次数以及目标象限停留时间明显增多(P<0.05或P<0.01),小鼠海马锥体细胞排列较紧密,形态完整,尼氏体数目增加,着色加深,BACE1表达降低(P<0.05或P<0.01),P-TrkB、TrkB、BDNF表达增加(P<0.05或P<0.01)。结论 清心开窍方可能通过BDNF/TrkB通路改善APP/PS1小鼠学习记忆能力,对神经细胞起保护作用。

神经营养因子受体Trkb对湖羊垂体细胞增殖及促性腺激素分泌的影响

[目的]本研究旨在探究神经营养因子酪氨酸激酶B受体(Trkb)基因对湖羊垂体促性腺激素分泌的影响。[方法]利用qPCR方法对Trkb进行组织表达谱分析;构建Trkb过表达载体并转染至湖羊垂体细胞,利用qPCR、Western blot、EdU以及ELISA等技术检测过表达Trkb对垂体细胞增殖及促性腺激素分泌的影响。[结果]Trkb在湖羊心、肝、脾、肺、肾以及下丘脑和垂体等各个组织中均有表达,但在垂体中表达水平显著高于其他组织(P<0.05)。Trkb在湖羊垂体组织不同发育阶段差异表达,其中在6月龄垂体组织中高表达(P<0.05),在5日龄和3月龄表达水平较低。与对照组相比,过表达Trkb基因显著促进了垂体细胞增殖率(P<0.05),增殖标记基因Pcna表达水平与Bcl2/Bax比值均显著提高(P<0.05)。此外,过表达Trkb显著提高了促性腺激素相关基因Fshβ和Lhβ的表达水平,促进了垂体细胞促卵泡素(FSH)分泌(P<0.05)。[结论]过表达Trkb能够显著促进湖羊垂体细胞增殖,降低细胞凋亡水平从而显著提高促性腺激素的分泌水平。本研究初步验证Trkb基因在湖羊垂体细胞中功能,为深入研究Trkb调控垂体功能的分子机制提供了试验依据。

基于BDNF/TrkB/mTOR信号通路探讨通督醒脑针刺法改善脑缺血再灌注大鼠学习记忆障碍机制研究

目的:观察电针神庭、百会对脑缺血再灌注大鼠学习记忆能力的影响。方法:制备脑缺血再灌注大鼠(MCAO)模型,将40只雄性SD大鼠随机分为假手术组10只、模型组和电针组各15只,电针组行电针神庭、百会治疗,假手术组与模型组大鼠每天进行抓取,不进行其他治疗干预。观察治疗前后各组神经功能缺损评分、逃避潜伏期和穿越逃生平台次数、脑梗死体积、大鼠海马CA1区神经元形态,海马细胞形态、海马组织BDNF/TrkB/mTOR信号通路相关蛋白表达。结果:与假手术组比较,模型组的神经功能评分显著升高(P<0.01);逃避潜伏期显著延长(P<0.01);穿越原平台次数显著减少(P<0.01);海马CA1区神经元数量减少、萎缩,细胞排列紊乱和细胞肿胀;大鼠海马细胞排列稀疏,界限不清,胞质染色不均匀,胞核皱缩,周围表现为炎性细胞浸润。与模型组比较,治疗后电针组的神经功能评分显著降低(P<0.01);在手术后第13天逃避潜伏期显著缩短(P<0.01);第14天穿越原平台次数显著增加(P<0.01);脑梗死体积明显缩小(P<0.01);电针组海马组织中BDNF、TrkB、mTOR含量明显升高(P<0.01);电针组中海马细胞排列整齐,界限清楚,胞质染色均匀,胞核饱满,周围炎性浸润得到明显改善。结论:通督醒脑针刺法可激活BDNF/TrkB/mTOR信号通路,改善认知功能,改善学习记忆能力,减轻神经元损伤。

电针对甲基苯丙胺戒断后抑郁小鼠海马水通道蛋白4及BDNF/TrkB/CREB信号通路的影响

目的观察电针对甲基苯丙胺(MTHE)戒断后抑郁小鼠海马水通道蛋白4(AQP4)及脑源性神经营养因子(BDNF)/酪氨酸蛋白激酶B(TrkB)/环磷腺苷效应元件结合蛋白(CREB)信号通路的影响,探讨电针改善MTHE戒断后抑郁潜在的作用机制。方法健康雄性C57BL/6J小鼠随机分为空白组、模型组和电针组,每组10只。模型组、电针组采用条件性位置偏爱实验(CPP)复制小鼠MTHE成瘾模式,自然戒断后制备戒断后小鼠抑郁模型。空白组、模型组、电针组不给予任何干预,电针组取“百会”、“大椎”穴给予电针干预,选用连续波,频率2 Hz,1次/d,15 min/次,连续治疗28 d。分别于戒断后和干预后对各组小鼠进行强迫游泳试验和开放旷场试验,Western blot法检测小鼠海马AQP4、BDNF、TrkB、CREB和p-CREB等蛋白表达情况,免疫荧光染色法检测小鼠海马AQP4表达情况,实时荧光定量PCR法检测小鼠海马AQP4 mRNA表达。结果造模后,与空白组比较,模型组、电针组CPP值均升高(均P<0.01),模型组、电针组CPP值差异无统计学意义(P>0.05)。戒断后,与空白组比较,模型组、电针组水中自主不动状态持续时间均增加(均P<0.01)、中央区活动持续时间均减少(均P<0.01),模型组与电针组差异无统计学意义(P>0.05);干预后,与空白组比较,模型组、电针组水中自主不动状态持续时间增加(P<0.01)、中央区活动持续时间减少(P<0.01),与模型组比较,电针组水中自主不动状态持续时间减少(P<0.01),中央区活动持续时间增加(P<0.01);干预后,与空白组比较,模型组、电针组AQP4、BDNF、TrkB、CREB、p-CREB蛋白表达均减少(均P<0.01),与模型组比较,电针组AQP4、BDNF、TrkB、CREB、p-CREB蛋白表达均增加(均P<0.01)。干预后,与空白组比较,模型组、电针组AQP4阳性减少(P<0.01),与模型组比较,电针组AQP4阳性表达增加(P<0.01)。干预后,与空白组比较,模型组、电针组AQP4 mRNA表达减少(P<0.01)。干预后,与模型组比较,电针组AQP4 mRNA表达增加(P<0.01)。结论电针可改善METH戒断后小鼠抑郁样行为,其作用机制可能与调控AQP4表达,以及BDNF/TrkB/CREB信号通路活性相关。

龙眼肉调节肠道菌群和BDNF-TrkB通路抗AD的作用机制研究

目的:基于肠道菌群和脑源性神经营养因子(BDNF)-酪氨酸激酶受体B (TrkB)信号通路探讨龙眼肉抗阿尔茨海默病(AD)的作用机制。方法:采用煎煮法制备龙眼肉水提取物,采用D-半乳糖(140 mg·kg–1,ip)/AlCl3(20 mg·kg–1,ig)联合诱导建立小鼠AD模型,Morris水迷宫检测小鼠学习记忆能力,16S-rDNA测序检测小鼠粪便菌群多样性,Western blot检测小鼠海马区淀粉样前体蛋白(APP)、磷酸化Tau蛋白(p-Tau)、BDNF、TrkB和p-TrkB表达。结果:龙眼肉缩短了AD小鼠的逃避潜伏期(P<0.01);增加了其平台穿越次数、停留时间和停留时间百分比(P<0.001);降低了AD小鼠海马APP、p-Tau蛋白水平(P<0.05);改变了AD小鼠粪便微生物在界、门、纲、目、科、属、种7个层面上的多样性差异,以属水平为例,使异常升高的拟普雷沃菌属、瘤胃球菌科_UCG-014属、普雷沃氏菌科_UCG-001属、理研菌科RC9_gut_group属、瘤胃梭菌属和瘤胃球菌属_1丰度显著降低(P<0.05),鼠杆菌属和毛螺菌科_UCG-001属丰度显著升高(P<0.01);并且提高了BDNF、p-TrkB及p-TrkB/TrkB相对表达(P<0.05)。结论:龙眼肉可以改善AD小鼠的学习记忆能力,调节菌群多样性、激活BDNF-TrkB信号通路可能是其抗AD的作用机制。

Immunomodulation of Proton-activated G Protein-coupled Receptors in Inflammation

Proton-activated G protein-coupled receptors(GPCRs),initially discovered by Ludwig in 2003,are widely distributed in various tissues.These receptors have been found to modulate the immune system in several inflammatory diseases,including inflammatory bowel disease,atopic dermatitis,and asthma.Proton-activated GPCRs belong to the G protein-coupled receptor family and can detect alternations in extracellular pH.This detection triggers downstream signaling pathways within the cells,ultimately influencing the function of immune cells.In this review,we specifically focused on investigating the immune response of proton-activated GPCRs under inflammatory conditions.

Targeting TrkB–PSD-95 coupling to mitigate neurological disorders

Tropomyosin receptor kinase B(TrkB)signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and memory.The activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre-or postsynaptic TrkB resulting in the strengthening of synapses,reflected by long-term potentiation.Postsynaptically,the association of postsynaptic density protein-95 with TrkB enhances phospholipase Cγ-Ca^(2+)/calmodulin-dependent protein kinaseⅡand phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term potentiation.In this review,we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders.A reduction of TrkB signaling has been observed in neurodegenerative disorders,such as Alzheimer's disease and Huntington's disease,and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and depression.Treatment with brain-derived neurotrophic factor is problematic,due to poor pharmacokinetics,low brain penetration,and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 isoform.Although TrkB agonists and antibodies that activate TrkB are being intensively investigated,they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific functions.Targeting TrkB–postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.