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.

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.

Clinicopathological Features and Long-Term Prognostic Role of Human Epidermal Growth Factor Receptor-2 Low Expression in Chinese Patients with Early Breast Cancer:A Single-Institution Study

Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC.Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups.Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszelχ^(2)test,P<0.001,Pearson’s R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%.Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.

Leukocyte immunoglobulin-like receptor B2:A promising biomarker for colorectal cancer

According to the latest global cancer statistics,colorectal cancer(CRC)has emerged as the third most prevalent malignant tumor across the globe.In recent decades,the medical field has implemented several levels of CRC screening tests,encompassing fecal tests,endoscopic examinations,radiological examinations and blood tests.Previous studies have shown that leukocyte immunoglobulin-like receptor B2(LILRB2)is involved in inhibiting immune cell function,immune evasion,and promoting tumor progression in acute myeloid leukemia and nonsmall cell lung cancer.However,its interaction with CRC has not been reported yet.Recently,a study published in the World Journal of Gastroenterology revealed that LILRB2 and its ligand,angiopoietin-like protein 2,are markedly overexpressed in CRC.This overexpression is closely linked to tumor progression and is indicative of a poor prognosis.The study highlights the potential of utilizing the concentration of LILRB2 in serum as a promising biomarker for tumors.However,there is still room for discussion regarding the data processing and analysis in this research.

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance.Human epidermal growth factor receptor 2(HER2)is one of the most important targets in targeted therapy for gastric cancer.Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer.The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified.However,monoclonal antibodies,due to their large molecular weight,inability to penetrate the blood-brain barrier,and drug resistance,lead to decreased therapeutic efficacy,so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer.Small-molecule tyrosine kinase inhibitors,such as lapatinib and pyrrotinib,have the advantages of small molecular weight,penetrating the blood-brain barrier and high oral bioavailability,and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future.Antibo-drug conjugate,such as T-DM1 and T-DXd,can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing,and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab.Therefore,after more detailed stratification of gastric cancer patients,various gastric cancer drugs targeting HER2 are expected to play a more significant role.

PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

Adenosine A_(2A)receptor blockade attenuates excitotoxicity in rat striatal medium spiny neurons during an ischemic-like insult

During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membrane ion gradients,occurs in vivo or in vitro during an energy failure.The neuromodulator adenosine is released in huge amounts during cerebral ischemia and exerts its effects by activating specific metabotropic receptors,namely:A_(1),A_(2A),A_(2B),and A_(3).The A_(2A)receptor subtype is highly expressed in striatal medium spiny neurons,which are particularly susceptible to ischemic damage.Evidence indicates that the A2Areceptors are upregulated in the rat striatum after stroke and the selective antagonist SCH58261 protects from exaggerated glutamate release within the first 4 hours from the insult and alleviates neurological impairment and histological injury in the following 24 hours.We recently added new knowledge to the mechanisms by which the adenosine A2Areceptor subtype participates in ischemia-induced neuronal death by performing patch-clamp recordings from medium spiny neurons in rat striatal brain slices exposed to oxygen and glucose deprivation.We demonstrated that the selective block of A2Areceptors by SCH58261 significantly reduced ionic imbalance and delayed the anoxic depolarization in medium spiny neurons during oxygen and glucose deprivation and that the mechanism involves voltage-gated K+channel modulation and a presynaptic inhibition of glutamate release by the A2Areceptor antagonist.The present review summarizes the latest findings in the literature about the possibility of developing selective ligands of A2Areceptors as advantageous therapeutic tools that may contribute to counteracting neurodegeneration after brain ischemia.

A Retrospective Analysis of Glucagon-Like Peptide 1 Receptor Agonists in Treating Type 2 Diabetes Mellitus Complicated by Nonalcoholic Fatty Liver Disease

Background: The objective of this study was to compare and analyze the variations in clinical indices before and after treatment of type 2 mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) that were treated with glucagon-like peptide 1 receptor agonists (GLP-1RAs). Methods: The electronic medical record system was utilized to search for a total of 16 patients with type 2 diabetes complicated by NAFLD who were hospitalized at the First Affiliated Hospital of Yangtze University from October 2022 to April 2023 and treated with GLP-1RA for the first time. The clinical indices were compared before and after 12 weeks of treatment with GLP-1RA. Results: The liver-spleen CT ratio (L/S), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) in all patients treated with GLP-1RA after 12 weeks were significantly different (P 0.05). The patients were categorized into two groups based on the types of GLP-1RAs. The changes in L/S, TC, TG, and LDL-C in the long-acting group after treatment were statistically significant (P Conclusions: GLP-1RAs can improve liver function, regulate lipid metabolism, and reduce the severity of fatty liver in patients with T2DM complicated by NAFLD, which demonstrates the importance of clinical applications.

Human epidermal growth factor receptor 2 expression level and combined positive score can evaluate efficacy of advanced gastric cancer

BACKGROUND Although treatment options for gastric cancer(GC)continue to advance,the overall prognosis for patients with GC remains poor.At present,the predictors of treatment efficacy remain controversial except for high microsatellite instability.AIM To develop methods to identify groups of patients with GC who would benefit the most from receiving the combination of a programmed cell death protein 1(PD-1)inhibitor and chemotherapy.METHODS We acquired data from 63 patients with human epidermal growth factor receptor 2(HER2)-negative GC with a histological diagnosis of GC at the Cancer Hospital,Chinese Academy of Medical Sciences between November 2020 and October 2022.All of the patients screened received a PD-1 inhibitor combined with chemotherapy as the first-line treatment.RESULTS As of July 1,2023,the objective response rate was 61.9%,and the disease control rate was 96.8%.The median progression-free survival(mPFS)for all patients was 6.3 months.The median overall survival was not achieved.Survival analysis showed that patients with a combined positive score(CPS)≥1 exhibited an extended trend in progression-free survival(PFS)when compared to patients with a CPS of 0 after receiving a PD-1 inhibitor combined with oxaliplatin and tegafur as the first-line treatment.PFS exhibited a trend for prolongation as the expression level of HER2 increased.Based on PFS,we divided patients into two groups:A treatment group with excellent efficacy and a treatment group with poor efficacy.The mPFS of the excellent efficacy group was 8 months,with a mPFS of 9.1 months after excluding a cohort of patients who received interrupted therapy due to surgery.The mPFS was 4.5 months in patients in the group with poor efficacy who did not receive surgery.Using good/poor efficacy as the endpoint of our study,univariate analysis revealed that both CPS score(P=0.004)and HER2 expression level(P=0.015)were both factors that exerted significant influence on the efficacy of treatment the combination of a PD-1 inhibitor and chemotherapy in patients with advanced GC(AGC).Finally,multivariate analysis confirmed that CPS score was a significant influencing factor.CONCLUSION CPS score and HER2 expression both impacted the efficacy of immunotherapy combined with chemotherapy in AGC patients who were non-positive for HER2.

Relationship of Toll-Like Receptors 2 and 4 Gene Polymorphisms with Essential Hypertension in Chinese Han Population

Objective: There are numerous studies suggesting that genetic polymor-phisms of inflammation factors Toll-like receptors 2 and 4 (TLR2, TLR4) might play a role in the pathophysiological process of hypertension. In this study, we evaluated the association in a sample of members of the Chinese Han population. Method: We selected four single nucleotide polymor-phisms (SNP) of TLR2 (rs3804099, rs3804100, rs7656411) and TLR4 (rs1927906) genes, and measured the distributions of genotypic and allelic frequencies in 1063 participants, including 391 essential hypertension pa-tients and 672 controls. Result: No significant differences in the genotypic and allelic frequencies of the four SNPs were detected between cases and controls. However, three haplotypes, CCG, TTG and TTT of TLR2, were significantly associated with a decrease in the risk of essential hyperten-sion (OR: 0.512, 95% CI: 0.397 - 0.660, P P = 0.0038;OR: 0.797, 95% CI: 0.667 - 0.952, P = 0.0122, respectively). Inversely, the risk of essential hypertension increased sig-nificantly in patients with the CTG, TCG or TCT haplotypes (OR: 2.924, 95% CI: 2.157 - 3.963, P P P Conclusion: Our study suggested that haplotypes (CCG, TTG, TTT, CTG, TCG and TCT) of TLR2 might have profound effects on the development of essential hypertension in the Chinese Han population.

MicroRNA-155 mediates endogenous angiotensin II type 1 receptor regulation:implications for innovative type 2 diabetes mellitus management

Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.

Expression of c-erbB-2 oncogene protein, epidermal growth factor receptor, and TGF-β1 in human pancreatic ductal adenocarcinoma

Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.

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.

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.

Leukocyte immunoglobulin-like receptor B2 overexpression as a promising therapeutic target and noninvasive screening biomarker for colorectal cancer

BACKGROUND Colorectal cancer(CRC)has become the second most deadly malignancy in the world,and the exploration of screening markers and precise therapeutic targets is urgent.Our previous research identified leukocyte immunoglobulin-like receptor B2(LILRB2)protein as a characteristic protein of CRC,but the association between LILRB2 expression and clinicopathological features,the internal mechanism related to CRC progression,and screening diagnostic efficacy are not clear.Therefore,we hypothesized that LILRB2 is significantly highly expressed in CRC tissues,correlated with advanced stage and a poor prognosis,and could be used as a therapeutic target and potential screening biomarker for CRC.AIM To explore whether LILRB2 can be used as a potential therapeutic target and noninvasive screening biomarker for CRC.METHODS Patients who underwent radical surgery for CRC at China-Japan Friendship Hospital between February 2021 and October 2022 were included.Cancer and paracancerous tissues were collected to verify LILRB2 expression,and the association between LILRB2 expression and clinicopathological features was analysed.Serum was collected from CRC patients,adenoma patients and healthy controls during the same period to assess the diagnostic value of LILRB2 as a noninvasive screening biomarker,and its diagnostic value was further compared with that of the traditional markers carcinoembryonic antigen(CEA)and carbohydrate antigen 19-9(CA19-9).RESULTS A total of 58 CRC patients were included,and LILRB2 protein was significantly overexpressed in cancer tissues compared with paracancerous tissues(P<0.001).Angiopoietin-like protein 2(ANGPTL2)protein,as the ligand of LILRB2,was synergistically overexpressed in CRC tissues(P<0.001),and overexpression of LILRB2 and ANGPTL2 protein was significantly correlated with poor to moderate differentiation,vascular involvement,lymph node metastasis,distant metastasis,advanced tumor-node-metastasis stage and a poor prognosis(P<0.05),which suggested that LILRB2 and ANGPTL2 are closely associated with CRC progression.In addition,serum LILRB2 concentrations increased stepwise in healthy individuals,adenoma patients and CRC patients with statistically significant differences.The sensitivity of serum LILRB2 for the diagnosis of CRC was 89.74%,the specificity was 88.89%,the area under the curve was 0.95,and the diagnostic efficacy was better than that of conventional CEA and CA19-9.CONCLUSION LILRB2 protein can be used as a potential novel therapeutic target and noninvasive screening biomarker for CRC,which is beneficial for early screening and precise treatment.

The transient receptor potential melastatin 2:a new therapeutical target for Parkinson's disease?

The transient receptor potential melastatin 2 is a calcium-permeable cation channel member of the TRP family. Also known as an oxidative stress-activated channel, the transient receptor potential melastatin 2 gating mechanism is dependent on reactive oxygen species. In pathological conditions, transient receptor potential melastatin 2 is overactivated, leading to a Ca~(2+) influx that alters cell homeostasis and promotes cell death. The role of transient receptor potential melastatin 2 in neurodegenerative diseases, including Alzheimer's disease and ischemia, has already been described and reviewed. However, data on transient receptor potential melastatin 2 involvement in Parkinson's disease pathology has emerged only in recent years and the issue lacks review studies that focus specifically on this topic. The present review aims to elucidate the role of the transient receptor potential melastatin 2 channel in Parkinson's disease by reviewing, summarizing, and discussing the in vitro, in vivo, and human studies published until August 2022. Here we describe fourteen studies that evaluated the transient receptor potential melastatin 2 channel in Parkinson's disease. The Parkinson's disease model used, transient receptor potential melastatin 2 antagonist and genetic approaches, and the main outcomes reported were discussed. The studies described transient receptor potential melastatin 2 activation and enhanced expression in different Parkinson's disease models. They also evidenced protective and restorative effects when using transient receptor potential melastatin 2 antagonists, knockout, or silencing. This review provides a literature overview and suggests where there is a need for more research. As a perspective point, this review shows evidence that supports transient receptor potential melastatin 2 as a pharmacological target for Parkinson's disease in the future.

Transcriptome sequencing and experiments reveal the effect of formyl peptide receptor 2 on liver homeostasis

BACKGROUND Formyl peptide receptor 2(Fpr2)is an important receptor in host resistance to bacterial infections.In previous studies,we found that the liver of Fpr2-/-mice is the most severely damaged target organ in bloodstream infections,although the reason for this is unclear.AIM To investigate the role of Fpr2 in liver homeostasis and host resistance to bacterial infections.METHODS Transcriptome sequencing was performed on the livers of Fpr2-/-and wild-type(WT)mice.Differentially expressed genes(DEGs)were identified in the Fpr2-/-and WT mice,and the biological functions of DEGs were analyzed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis.Quantitative real time-polymerase chain reaction(qRT-PCR)and western blot(WB)analyses were used to further validate the expression levels of differential genes.Cell counting kit-8 assay was employed to investigate cell survival.The cell cycle detection kit was used to measure the distribution of cell cycles.The Luminex assay was used to analyze cytokine levels in the liver.The serum biochemical indices and the number of neutrophils in the liver were measured,and hepatic histopathological analysis was performed.RESULTS Compared with the WT group,445 DEGs,including 325 upregulated genes and 120 downregulated genes,were identified in the liver of Fpr2-/-mice.The enrichment analysis using GO and KEGG showed that these DEGs were mainly related to cell cycle.The qRT-PCR analysis confirmed that several key genes(CycA,CycB1,Cdc20,Cdc25c,and Cdk1)involved in the cell cycle had significant changes.The WB analysis confirmed a decrease in the expression of CDK1 protein.WRW4(an antagonist of Fpr2)could inhibit the proliferation of HepG2 cells in a concentration dependent manner,with an increase in the number of cells in the G0/G1 phase,and a decrease in the number of cells in the S phase.Serum alanine aminotransferase levels increased in Fpr2-/-mice.The Luminex assay measurements showed that interleukin(IL)-10 and chemokine(C-X-C motif)ligand(CXCL)-1 levels were significantly reduced in the liver of Fpr2-/-mice.There was no difference in the number of neutrophils,serum C-reactive protein levels,and liver pathology between WT and Fpr2-/-mice.CONCLUSION Fpr2 participates in the regulation of cell cycle and cell proliferation,and affects the expression of IL-10 and CXCL-1,thus playing an important protective role in maintaining liver homeostasis.

EVs-mediated delivery of CB2 receptor agonist for Alzheimer’s disease therapy

Alzheimer’s disease(AD)is a typical neurodegenerative disease that leads to irreversible neuronal degeneration,and effective treatment remains elusive due to the unclear mechanism.We utilized biocompatible mesenchymal stem cell-derived extracellular vesicles as carriers loaded with the CB2 target medicine AM1241(EVs-AM1241)to protect against neurodegenerative progression and neuronal function in AD model mice.According to the results,EVs-AM1241 were successfully constructed and exhibited better bioavailability and therapeutic effects than bare AM1241.The Morris water maze(MWM)and fear conditioning tests revealed that the learning and memory of EVs-AM1241-treated model mice were significantly improved.In vivo electrophysiological recording of CA1 neurons indicated enhanced response to an auditory conditioned stimulus following fear learning.Immunostaining and Western blot analysis showed that amyloid plaque deposition and amyloidβ(Aβ)-induced neuronal apoptosis were significantly suppressed by EVs-AM1241.Moreover,EVs-AM1241 increased the number of neurons and restored the neuronal cytoskeleton,indicating that they enhanced neuronal regeneration.RNA sequencing revealed that EVs-AM1241 facilitated Aβphagocytosis,promoted neurogenesis and ultimately improved learning and memory through the calcium-Erk signaling pathway.Our study showed that EVs-AM1241 efficiently reversed neurodegenerative pathology and enhanced neurogenesis in modelmice,indicating that they are very promising particles for treating AD.

Study of the roles of caspase-3 and nuclear factor kappa B in myenteric neurons in a P2X7 receptor knockout mouse model of ulcerative colitis

BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.

Adenosine 2A receptor contributes to the facilitation of postinfectious irritable bowel syndrome by γδ T cells via the PKA/CREB/NF-κB signaling pathway

BACKGROUND Immunological dysfunction-induced low-grade inflammation is regarded as one of the predominant pathogenetic mechanisms in post-infectious irritable bowel syndrome(PI-IBS).γδT cells play a crucial role in innate and adaptive immunity.Adenosine receptors expressed on the surface ofγδT cells participate in intestinal inflammation and immunity regulation.AIM To investigate the role ofγδT cell regulated by adenosine 2A receptor(A2AR)in PI-IBS.METHODS The PI-IBS mouse model has been established with Trichinella spiralis(T.spiralis)infection.The intestinal A2AR and A2AR inγδT cells were detected by immunohistochemistry,and the inflammatory cytokines were measured by western blot.The role of A2AR on the isolatedγδT cells,including proliferation,apoptosis,and cytokine production,were evaluated in vitro.Their A2AR expression was measured by western blot and reverse transcription polymerase chain reaction(RT-PCR).The animals were administered with A2AR agonist,or A2AR antagonist.Besides,γδT cells were also injected back into the animals,and the parameters described above were examined,as well as the clinical features.Furthermore,the A2AR-associated signaling pathway molecules were assessed by western blot and RT-PCR.RESULTS PI-IBS mice exhibited elevated ATP content and A2AR expression(P<0.05),and suppression of A2AR enhanced PI-IBS clinical characteristics,indicated by the abdominal withdrawal reflex and colon transportation test.PI-IBS was associated with an increase in intestinal T cells,and cytokine levels of interleukin-1(IL-1),IL-6,IL-17A,and interferon-α(IFN-α).Also,γδT cells expressed A2AR in vitro and generated IL-1,IL-6,IL-17A,and IFN-α,which can be controlled by A2AR agonist and antagonist.Mechanistic studies demonstrated that the A2AR antagonist improved the function ofγδT cells through the PKA/CREB/NF-κB signaling pathway.CONCLUSION Our results revealed that A2AR contributes to the facilitation of PI-IBS by regulating the function ofγδT cells via the PKA/CREB/NF-κB signaling pathway.