Targeting α7 nicotinic acetylcholine receptors: a future potential for neuroprotection from traumatic brain injury

Traumatic brain injury （TBI） poses a significant socioeconomic burden in the world. The long lasting consequences in cognitive impairments are often underreported and its mechanisms are unclear. In this perspective, cholinergic dysfunction and thera-peutic strategy targeting this will be reviewed. Novel agents that can target specific subtype of acetylcholine receptors have been developed over the recent years and are at various stages of development, which include AR-R 17779, GTS-21, SSR- 180711A, AR-R17779, and PNU-282987. A detailed review on this topic has been previously published （Shin and Dixon, 2015）.

Activities of nicotinic acetylcholine receptors modulate neurotransmission and synaptic architecture

The cholinergic system is involved in a broad spectrum of brain function, and its failure has been implicated in Alzheimer＇s disease. Acetylcholine transduces signals through muscarinic and nicotinic acetylcholine receptors, both of which influence synaptic plasticity and cognition. However, the mechanisms that relate the rapid gating of nicotinic acetylcholine receptors to persistent changes in brain function have remained elusive. Recent evidence indicates that nicotinic acetylcholine receptors activities affect synaptic morphology and density, which result in persistent rearrangements of neural connectivity. Further investigations of the relationships between nicotinic acetylcholine receptors and rearrangements of neural circuitry in the central nervous system may help understand the pathogenesis of Alzheimer＇s disease.

Altered Expression of Nicotinic Receptors in Perinatal Life Related to Prenatal Exposure to Toxics—An Overview of the Research Carried Out on This Topic at the “Lino Rossi” Research Center of the Milan University

The article aims to underline the impact of nicotine and pesticides on neuronal α7-nicotinic acetylcholine receptors expression in brainstem regions receiving cholinergic projections, given their fundamental role during the neuronal development. The in-depth histopathological/immunohistochemical examination of the autonomic nervous system performed at the “Lino Rossi” Research Center of the Milan University on a wide group of sudden unexpected fetal and infant deaths, highlighted the frequent hypodevelopment of brainstem structures checking the vital functions associated to altered expression of α7-nicotinic acetylcholine receptors and smoke absorption in pregnancy. A dysregulation of the catecholamine system was also observed in the cerebellar cortex of the same cases. However, in a not negligible percentage of sudden deaths with altered expression of α7-nicotinic receptors, the mothers never smoked but lived in rural areas. Specific analytical procedures showed the presence of agricultural pesticides in cerebral cortex samples of these victims. Therefore, it is possible to believe that the exposition to pesticides during pregnancy can produce the same harmful effects as nicotine on the nicotinic acetylcholine receptors. Moreover, alterations of α7-nicotinic acetylcholine receptors receptor expression were also detected in the lungs of many sudden perinatal death victims, allowing to consider even these findings as possible consequence of maternal exposure to toxic factors.

Effect of soman on the neuro-muscle junctional and extrajunctional nicotinic acetylcholine receptors

Autoradiography of nicotinic acetytcholine receptors(N-ACHR)with the application ofhistochemical staining location of cholinesterase was used to observe the effect of soman onjunctional and extrajunctional N-AChR.Testing with the diaphragms and extensor digitorum longusmuscles of mice and rats,we found that soman mainly increased the number of extrajunctionalN-AChR.It did not alter the number of junctional N-AChR significantly,nor did it have any pro-nouneed effects on the gtycoprotein property and isoelectfic point(pI)of junctional andextrajunctional N-AChR.The change of extrajunctional N-AChR number caused by somanis similar to the phenomenon of increased extrajunctional N-AChR number and sensitivity resultingfrom denervation,but the mechanism of action is different from the latter.The increase ofN-AChR number is one of the important characteristics of soman poisoning which make it differ-ent from other nerve agents.To maintain the metabofic balance of N-AChR may be an importantnew approach to the treatment of soman poisoning.

Neuroprotective and anti-inflammatory effects of a therapy combining agonists of nicotinic α7 and σ1 receptors in a rat model of Parkinson’s disease

To date there is no treatment able to stop or slow down the loss of dopaminergic neurons that characterizes Parkinson’s disease.It was recently observed in a rodent model of Alzheimer’s disease that the interaction between the α7 subtype of nicotinic acetylcholine receptor(α7-nAChR)and sigma-1 receptor(σ1-R)could exert neuroprotective effects through the modulation of neuroinflammation which is one of the key components of the pathophysiology of Parkinson’s disease.In this context,the aim of the present study was to assess the effects of the concomitant administration of N-(3R)-1-azabicyclo[2.2.2]oct-3-yl-furo[2,3-c]pyridine-5-carboxamide(PHA)543613 as an α7-nAChR agonist and 2-(4-morpholinethyl)1-phenylcyclohexanecarboxylate(PRE)-084 as aσ1-R agonist in a well-characterized 6-hydroxydopamine rat model of Parkinson’s disease.The animals received either vehicle separately or the dual therapy PHA/PRE once a day until day 14 postlesion.Although no effect was noticed in the amphetamine-induced rotation test,our data has shown that the PHA/PRE treatment induced partial protection of the dopaminergic neurons(15-20%),assessed by the dopamine transporter density in the striatum and immunoreactive tyrosine hydroxylase in the substantia nigra.Furthermore,this dual therapy reduced the degree of glial activation consecutive to the 6-hydroxydopamine lesion,i.e,the 18 kDa translocation protein density and glial fibrillary acidic protein staining in the striatum,and the CD11b and glial fibrillary acidic protein staining in the substantia nigra.Hence,this study reports for the first time that concomitant activation of α7-nAChR andσ1-R can provide a partial recovery of the nigro-striatal dopaminergic neurons through the modulation of microglial activation.The study was approved by the Regional Ethics Committee(CEEA Val de Loire n°19)validated this protocol(Authorization N°00434.02)on May 15,2014.

Modulation by desensitized nicotinic receptors on metabolism of DA in striatum derived from the hemiparkinsonian model

Objective: The purpose of this study was to investigate the effects of desensitized nicotinic receptors(n ACh Rs) on striatal dopaminergic system in the hemiparkinsonian rats treated with 6-hydroxydopamine(6-OHDA). Methods: We examined the effects of desensitized n ACh Rs on the levels of dopamine(DA) and its metabolites, m RNA expression of dopamine receptor D1,D2 and monoamine oxidase B(MAO-B) in the striatum of 6-OHDA-lesioned rats using high-performance liquid chromatography and reverse transcription-polymerase chain reaction. Results: The results showed that n ACh Rs desensitization following repeated nicotine stimulation could reverse significantly the decrease of striatal DA and its metabolites levels and the increase in DA turnover in lesioned side striatum of hemiparkinsonian rats. Dopamine D1 receptor m RNA expression increased significantly, whereas dopamine D2 receptor m RNA expression remained unchanged in lesioned side striatum of nicotine-treated rats compared to 6-OHDA-lesioned rats when n ACh Rs were desensitized. Meanwhile, nicotine-treated rats displayed a significant decrease in MAO-B m RNA expression in lesioned side striatum compared to 6-OHDA-lesioned rats after n ACh Rs desensitization. Conclusion: These results suggest that n ACh Rs desensitization could promote DA level, upregulate dopamine D1 receptor expression and downregulate MAO-B expression in striatum of hemiparkinsonian rats.

Synthesis of 2-[^(18)F]fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine as a radioligand for imaging nicotinic acetylcholine receptors

Nicotinic acetylcholine receptors(nChRs) are involved in the various pharmacological effects or disease states.In order to study the central nChRs by PET or SPECT,some radioligands have been investigated.In this paper,the procedure for synthesis of 2-[^18F] fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine(2-[^18F0-A-85380),a potential PET ligand for in vivo imaging nicotinic acetylcholine receptor was described.2-[^18F]-A-85380 was prepared from the precursor,2-nitro-3-[(1-(tert-butoxycarbonyl)-2-(S0-azetidinyl)methoxy] pyridine(4),which was synthesized with commercial (S)-2-zaetid-inecarboxylic acid as starting material.The whole procedure for radiosynthesis and purification was executed in about 1h and 45-55% of the added fluorine-18 was found in the purified 2-[^18F]-A-85380,with specific activity of 1.0-2.2×10^11 Bq/umol.

Retinal ganglion cell neuroprotection induced by activation of alpha7 nicotinic acetylcholine receptors

Glaucoma is a group of degenerative retinal diseases that damage the eye’s optic nerve and can result in vision loss and blindness.It is characterized by optic neuropathy,cupping of the optic disk.

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.

Metabotropic glutamate receptors(mGluRs)in epileptogenesis:an update on abnormal mGluRs signaling and its therapeutic implications

Epilepsy is a neurological disorder characterized by high morbidity,high recurrence,and drug resistance.Enhanced signaling through the excitatory neurotransmitter glutamate is intricately associated with epilepsy.Metabotropic glutamate receptors(mGluRs)are G protein-coupled receptors activated by glutamate and are key regulators of neuronal and synaptic plasticity.Dysregulated mGluR signaling has been associated with various neurological disorders,and numerous studies have shown a close relationship between mGluRs expression/activity and the development of epilepsy.In this review,we first introduce the three groups of mGluRs and their associated signaling pathways.Then,we detail how these receptors influence epilepsy by describing the signaling cascades triggered by their activation and their neuroprotective or detrimental roles in epileptogenesis.In addition,strategies for pharmacological manipulation of these receptors during the treatment of epilepsy in experimental studies is also summarized.We hope that this review will provide a foundation for future studies on the development of mGluR-targeted antiepileptic drugs.

Characterization of Domeless receptors and the role of Bd Domeless3 in anti-symbiont-like virus defense in Bactrocera dorsalis

The Janus kinase/signal transducers and activators of transcription(JAK/STAT)signaling pathway play a pivotal role in innate immunity.Among invertebrates,Domeless receptors serve as the key upstream regulators of this pathway.In our study on Bactrocera dorsalis,we identified three cytokine receptors:BdDomeless1,BdDomeless2,and BdDomeless3.Each receptor encompasses five fibronectin-type-III-like(FN III)extracellular domains and a transmembrane domain.Furthermore,these receptors exhibit the increased responsiveness to diverse pathogenic challenges.Notably,only BdDomeless3 is upregulated during symbiont-like viral infections.Moreover,silencing BdDomeless3 enhanced the infectivity of Bactrocera dorsalis cripavirus(BdCV)and B.dorsalis picorna-like virus(BdPLV),underscoring BdDomeless3’s crucial role in antiviral defense of B.dorsalis.Following the suppression of Domeless3 expression,six antimicrobial peptide genes displayed decreased expression,potentially correlating with the rise in viral infectivity.To our knowledge,this is the first study identifying cytokine receptors associated with the JAK/STAT pathway in tephritid flies,shedding light on the immune mechanisms of B.dorsalis.

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.

Role of bitter contributors and bitter taste receptors:a comprehensive review of their sources,functions and future development

Bitterness,one of the 5“basic tastes”,is usually undesired by humans.However,abundant literature reported that bitter fruits and vegetables have beneficial health effects due to their bitter contributors.This review provided an updated overview of the main bitter contributors of typical bitter fruits and vegetables and their health benefits.The main bitter contributors,including phenolics,terpenoids,alkaloids,amino acids,nucleosides and purines,were summarized.The bioactivities and wide range of beneficial effects of them on anti-cancers,anti-inflammations,anti-microbes,neuroprotection,inhibiting chronic and acute injury in organs,as well as regulating behavior performance and metabolism were reported.Furthermore,not only did the bitter taste receptors(taste receptor type 2 family,T2Rs)show taste effects,but extra-oral T2Rs could also be activated by binding with bitter components,regulating physiological activities via modulating hormone secretion,immunity,metabolism,and cell proliferation.This review provided a new perspective on exploring and explaining the nutrition of bitter foods,revealing the relationship between the functions of bitter contributors from food and T2Rs.Future trends may focus on revealing the possibility of T2Rs being targets for the treatment of diseases,exploring the mechanism of T2Rs mediating the bioactivities,and making bitter foods more acceptable without getting rid of bitter contributors.

Exploring the vital role of microglial membrane receptors in Alzheimer’s disease pathogenesis: a comprehensive review

Neurodegenerative diseases constitute a broad category of diseases caused by the degeneration of the neurons.They are mainly manifested by the gradual loss of neuron structure and function and eventually can cause death or loss of neurons.As the global population ages rapidly,increased people are being diagnosed with neurodegenerative diseases.It has been established that the onset of Alzheimer’s disease(AD)is closely linked with increasing age and its major pathological features include amyloid-beta plaques(Aβ),Tau hyperphosphorylation,Neurofibrillary tangles(NFTs),neuronal death as well as synaptic loss.The involvement of microglia is crucial in the pathogenesis and progression of AD and exhibits a dual role.For instance,in the early stage of AD,microglia surface membrane proteins or receptors can participate in immunophagocytosis,and anti-inflammatory functions and act as a physical barrier after recognizing various ligands such as Aβand NFTs.However,in the later stage of the disease,membrane receptors on the surface of microglia can cause its activation to release a substantial quantity of pro-inflammatory factors.Which can amplify the neuroinflammatory response.The rapid decline of normal immune phagocytosis can result in the continuous accumulation of abnormal proteins,leading to neuronal dysfunction and destruction of the formed physical barrier as well as the neurovascular microenvironment.It can also increase the transformation of microglia from anti-inflammatory phenotype M2 to pro-inflammatory phenotype M1,induce severe neuronal injury or apoptosis,and aggravate the progression of AD.Due to few articles have focused on the AD-related membrane protein receptors on microglia,thus in this paper,we have reviewed several representative microglial membrane proteins or receptors about their specific roles and functions implicated in AD,and expect that there will be more in-depth research and scientific research results in the treatment of AD by targeted regulation of microglia membrane protein receptors in the future.

Cortico-striatal gamma oscillations are modulated by dopamine D3 receptors in dyskinetic rats

Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.

Novel Role of Calcium-Sensitive Receptors in Chronic Hypoxia-Induced Proliferation of Pulmonary Vein Smooth Muscle Cells

Objective:Vascular remodeling due to chronic hypoxia(CH)occurs not only in the pulmonary arteries but also in the pulmonary veins.Pulmonary vascular remodeling arises from the proliferation of pulmonary vascular myocytes.However,the mechanism by which CH induces the proliferation of pulmonary vein smooth muscle cells(PVSMCs)is unknown.This study aimed to investigate the mechanism by which CH affects the proliferation of PVSMCs.Methods:PVSMCs were isolated from rat distal pulmonary veins and exposed to CH(4%O2,60h),and the expression of the calcium-sensitive receptor(CaSR)was detected by Western blotting and immunofluorescence.MTT assay was used to detect the proliferation viability of the cells,and the changes in the intracellular calcium concentration were detected by laser confocal scanning technique.Results:CaSR expression was present in rat distal PVSMCs,and CaSR protein expression was upregulated under hypoxia.The positive regulator spermine not only enhanced CH-induced CaSR upregulation but also enhanced CH-induced increase in cell viability and calcium ion concentration.The negative CaSR regulator NPS2143 not only attenuated CH-induced CaSR upregulation but also inhibited CH-induced cell viability and calcium ion concentration.Conclusion:CaSR-mediated hyperproliferation is a novel pathogenic mechanism for the development of proliferation in distal PVSMCs under CH conditions.

Nicotinic cholinergic receptors in esophagus:Early alteration during carcinogenesis and prognostic value

AIM: To compare expression of nicotinic cholinergic receptors(CHRNs) in healthy and squamous cell carcinoma-affected esophagus and determine the prognostic value.METHODS: We performed RT-q PCR to measure the expression of CHRNs in 44 esophageal samples from healthy individuals and in matched normal surrounding mucosa, and in tumors from 28 patientsdiagnosed with esophageal squamous cell carcinoma(ESCC). Next, we performed correlation analysis for the detected expression of these receptors with the habits and clinico-pathological characteristics of all study participants. In order to investigate the possible correlations between the expression of the different CHRN subunits in both healthy esophagus and tissues from ESCC patients, correlation matrices were generated. Subsequently, we evaluated whether the detected alterations in expression of the various CHRNs could precede histopathological modifications during the esophageal carcinogenic processes by using receiver operating characteristic curve analysis. Finally, we evaluated the impact of CHRNA5 and CHRNA7 expression on overall survival by using multivariate analysis.RESULTS: CHRNA3, CHRNA5, CHRNA7 and CHRNB4, but not CHRNA1, CHRNA4, CHRNA9 or CHRNA10, were found to be expressed in normal(healthy) esophageal mucosa. In ESCC, CHRNA5 and CHRNA7 were overexpressed as compared with patient-matched surrounding non-tumor mucosa(ESCC-adjacent mucosa; P < 0.0001 and P = 0.0091, respectively). Positive correlations were observed between CHRNA3 and CHRNB4 expression in all samples analyzed. Additionally, CHRNB4 was found to be differentially expressed in the healthy esophagus and the normalappearing ESCC-adjacent mucosa, allowing for distinguishment between these tissues with a sensitivity of 75.86% and a specificity of 78.95%(P = 0.0002). Finally, CHRNA5 expression was identified as an independent prognostic factor in ESCC; patients with high CHRNA5 expression showed an increased overall survival, in comparison with those with low expression. The corresponding age- and tumor stage-adjusted hazard ratio was 0.2684(95%CI: 0.075-0.97, P = 0.0448).CONCLUSION: Expression of CHRNs is homogeneous along healthy esophagus and deregulated in ESCC, suggesting a pathogenic role for these receptors in ESCC development and progression.

Nicotinic receptors modulate antitumor therapy response in triple negative breast cancer cells

BACKGROUND Triple negative breast cancer is more aggressive than other breast cancer subtypes and constitutes a public health problem worldwide since it has high morbidity and mortality due to the lack of defined therapeutic targets.Resistance to chemotherapy complicates the course of patients’treatment.Several authors have highlighted the participation of nicotinic acetylcholine receptors(nAChR)in the modulation of conventional chemotherapy treatment in cancers of the airways.However,in breast cancer,less is known about the effect of nAChR activation by nicotine on chemotherapy treatment in smoking patients.AIM To investigate the effect of nicotine on paclitaxel treatment and the signaling pathways involved in human breast MDA-MB-231 tumor cells.METHODS Cells were treated with paclitaxel alone or in combination with nicotine,administered for one or three 48-h cycles.The effect of the addition of nicotine(at a concentration similar to that found in passive smokers’blood)on the treatment with paclitaxel(at a therapeutic concentration)was determined using the 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.The signaling mediators involved in this effect were determined using selective inhibitors.We also investigated nAChR expression,and ATP“binding cassette”G2 drug transporter(ABCG2)expression and its modulation by the different treatments with Western blot.The effect of the treatments on apoptosis induction was determined by flow cytometry using annexin-V and 7AAD markers.RESULTS Our results confirmed that treatment with paclitaxel reduced MDA-MB-231 cell viability in a concentration-dependent manner and that the presence of nicotine reversed the cytotoxic effect induced by paclitaxel by involving the expression of functionalα7 andα9 nAChRs in these cells.The action of nicotine on paclitaxel treatment was linked to modulation of the protein kinase C,mitogen-activated protein kinase,extracellular signal-regulated kinase,and NF-κB signaling pathways,and to an up-regulation of ABCG2 protein expression.We also detected that nicotine significantly reduced the increase in cell apoptosis induced by paclitaxel treatment.Moreover,the presence of nicotine reduced the efficacy of paclitaxel treatment administered in three cycles to MDA-MB-231 tumor cells.CONCLUSION Our findings point to nAChRs as responsible for the decrease in the chemotherapeutic effect of paclitaxel in triple negative tumors.Thus,nAChRs should be considered as targets in smoking patients.

Expression and functional study of cholecystokinin-A receptors on the interstitial Cajal-like cells of the guinea pig common bile duct

BACKGROUND Many studies have shown that interstitial Cajal-like cell(ICLC)abnormalities are closely related to a variety of dynamic gastrointestinal disorders.ICLCs are pacemaker cells for gastrointestinal movement and are involved in the transmission of nerve impulses.AIM To elucidate the expression profile and significance of cholecystokinin-A(CCK-A)receptors in ICLCs in the common bile duct(CBD),as well as the role of CCK in regulating CBD motility through CCK-A receptors on CBD ICLCs.METHODS The levels of tyrosine kinase receptor(c-kit)and CCK-A receptors in CBD tissues and isolated CBD cells were quantified using the double immunofluorescence labeling technique.The CCK-mediated enhancement of the movement of CBD muscle strips through CBD ICLCs was observed by a muscle strip contraction test.RESULTS Immunofluorescence showed co-expression of c-kit and CCK-A receptors in the CBD muscularis layer.Observations of isolated CBD cells showed that c-kit was expressed on the surface of ICLCs,the cell body and synapse were colored and polygonal,and some cells presented protrusions and formed networks adjacent to the CBD while others formed filaments at the synaptic terminals of local cells.CCK-A receptors were also expressed on CBD ICLCs.At concentrations ranging from 10^(-6) mol/L to 10^(-10) mol/L,CCK promoted CBD smooth muscle contractility in a dose-dependent manner.In contrast,after ICLC removal,the contractility mediated by CCK in CBD smooth muscle decreased.CONCLUSION CCK-A receptors are highly expressed on CBD ICLCs,and CCK may regulate CBD motility through the CCK-A receptors on ICLCs.

The role of purinergic receptors in neural repair and regeneration after spinal cord injury

Spinal cord injury is a serious injury of the central nervous system that results in neurological deficits.The pathophysiological mechanisms underlying spinal cord injury,as well as the mechanisms involved in neural repair and regeneration,are highly complex.Although there have been many studies on these mechanisms,there is no effective intervention for such injury.In spinal cord injury,neural repair and regeneration is an important part of improving neurological function after injury,although the low regenerative ability of nerve cells and the difficulty in axonal and myelin regeneration after spinal cord injury hamper functional recovery.Large amounts of ATP and its metabolites are released after spinal cord injury and participate in various aspects of functional regulation by acting on purinergic receptors which are widely expressed in the spinal cord.These processes mediate intracellular and extracellular signalling pathways to improve neural repair and regeneration after spinal cord injury.This article reviews research on the mechanistic roles of purinergic receptors in spinal cord injury,highlighting the potential role of purinergic receptors as interventional targets for neural repair and regeneration after spinal cord injury.