[Diagnostic and prognostic values of flow cytometry in diffuse large B-cell lymphoma with bone marrow involvement].

Objective: To analyze the diagnostic and prognostic values of flow cytometry (FC) in diffuse large B cell lymphoma (DLBCL) with bone marrow involvement (BMI). Methods: The clinical data of 412 patients with newly diagnosed DLBCL, including 243 males and 169 females, aged 64 (28-92) years old, in the Department of Hematology at Peking University Third Hospital from December 2012 to June 2022 were retrospectively analyzed. All patients underwent bone marrow biopsy (BMB) and bone marrow FC. The patients with BMI by FC were further detected by fluorescence in situ hybridization (FISH) for gene analysis. The positive rates and consistency of BMI detected by BMB and FC were evaluated. According to the results of BMB and FC examinations, all patients were divided into four groups: the BMB+FC+group (115 cases), the BMB-FC+group (50 cases), the BMB+FC-group (8 cases, the results did not include in statistical analysis because of small sample size), and the BMB-FC-group (239 cases). The clinical features, treatment response rates, 5-year survival rates, and immunophenotype characteristics by FC in different groups were analyzed. Results: Among the 412 patients with DLBCL, the positivity rates of BMB and FC for BMI detection were 29.9% (123/412) and 40.0% (165/412), respectively. Good consistency between BMB and FC was found (Kappa=0.841, P=0.001). The numbers of extranodal involvement≥2, splenomegaly, huge mass, higher Ki-67 score, higher international prognostic index (IPI) score, thrombocytopenia, and elevated lactate dehydrogenase level were more prevalent in the BMB+FC+group than those in the BMB-FC+group and the BMB-FC-group (all P<0.05). The treatment response rate in BMB+FC+group was 63.5% (73/115), which was lower than those in BMB-FC+group (88.0%, 44/50, P=0.048) and BMB-FC-group (90.0%, 215/239, P=0.032), respectively. The 5-year overall survival rates in three groups were (53.6±9.7) %, (72.5±8.6) %, and (75.2±7.6) %, respectively, with a statistically significant difference (P=0.037). According to the FISH results of bone marrow, 102 cases were diagnosed as not otherwise specified (NOS), 48 cases were diagnosed as double hit lymphoma (DHL), and 15 cases were diagnosed as triple hit lymphoma (THL). Compared with NOS subtypes, the tumor cells in DHL or THL subtypes had higher proportion of increased side scatter (SSC), higher positive rates of CD10 expression, CD38 strong expression and CD56 expression, and lower proportion of surface immunoglobulin light chain restriction (all P<0.05). Conclusions: FC is well consistent with BMB in diagnosing DLBCL with BMI. Combined with FISH detection, FC can contribute to the auxiliary diagnosis and risk stratification for DHL and THL, and provide reference for the prognostic evaluation in DLBCL with BMI.

[Study on mechanisms of Th17/Treg imbalance in patients with cystic echinococcosis based on miRNA expression profiles].

OBJECTIVE: To investigate the serum microRNA (miRNA) expression and examine the impact of miRNA expression profiles on T helper type 17 (Th17)/regulatory T cells (Treg) imbalance among patients with cystic echinococcosis, so as to provide insights into the illustration of the mechanisms underlying chronic Echinococcus granulosus infections, and long-term pathogenesis. METHODS: Total RNA was extracted from the sera of cystic echinococcosis patients and healthy controls, and subjected to high-throughput sequencing with the Illumina sequencing platform. Known miRNAs were annotated and new miRNAs were predicted using the miRBase database and the miRDeep2 tool, and differentially expressed miRNAs were identified. The target genes of differentially expressed miRNAs were predicted using the software miRanda and TargetScan, and the intersection was selected for Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Among the differentially expressed miRNAs with the 20 highest fold changes, miRNAs that targeted genes relating to key transcription factors RORC and FOXP3 that determine the production of Th17 and Treg cells or their important regulatory pathways (PI3K-Akt and mTOR pathways) were matched. RESULTS: A total of 53 differentially expressed miRNAs were screened in sera of cystic echinococcosis patients and healthy controls, including 47 up-regulated miRNAs and 6 down-regulated miRNAs. GO enrichment analysis showed that these differentially expressed miRNA were involved DNA transcription and translation, cell components, cell morphology, neurodevelopment and metabolic decomposition, and KEGG pathway analysis showed that the differentially expressed miRNA were mainly involved in MAPK, PI3K-Akt and mTOR signaling pathways. Among the differentially expressed miRNAs with the 20 highest fold changes, there were 3 miRNAs that had a potential for target regulation of RORC, and 15 miRNAs that had a potential to target the PI3K-Akt and mTOR signaling pathways. CONCLUSIONS: Significant changes are found in serum miRNA expression profiles among patients with E. granulosus infections, and differentially expressed miRNAs may lead to Th17/Treg imbalance through targeting the key transcription factors of Th17/Treg or PI3K-Akt and mTOR pathways, which facilitates the long-term parasitism of E. granulosus in hosts and causes a chronic disease.

Nuclear export protein CSE1L interacts with P65 and promotes NSCLC growth via NF-κB/MAPK pathway.

Non-small cell lung cancer (NSCLC) is characterized with high morbidity and mortality, mainly due to frequent recurrence and metastasis. However, the underlying molecular mechanisms of NSCLC tumorigenesis are largely unclear. Through data mining in the ONCOMINE and Gene Expression Omnibus (GEO) databases, the expression of CSE1L (chromosome segregation like 1 protein/CAS), an exportin, was identified to be significantly upregulated in NSCLC and positively associated with poor prognosis of patients. By use of in vitro and in vivo gain- and loss-of-function experiments, we found that CSE1L can promote NSCLC cell proliferation while inhibiting cell apoptosis. Through immunoprecipitation and mass spectrometry experiments, we demonstrated that CSE1L interacted with RELA (named as P65) and affected its location in the nucleus. Moreover, we found that one of the mechanisms by which CSE1L promotes proliferation and inhibits apoptosis is through activating the nuclear factor-κB (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway. In summary, our findings indicated an oncogenic role of CSE1L in NSCLC tumorigenesis.

[The pathological diagnosis and differential diagnosis of hematopoietic cell tumors of ambiguous lineage].

Objective: To explore the key points of the pathological and differential diagnoses of extra-medullary masses of hematopoietic cell tumors of ambiguous lineage, and to discuss the possible solutions. Methods: Five hematopoietic cell tumors of ambiguous lineage cases were collected, including myeloid sarcoma, mixed phenotype acute leukemia, B/myeloid, T-lymphoblastic lymphoma combined with acute myeloid leukemia, acute undifferentiated leukemia with cutaneous MPDCP and early T-precursor cell acute lymphoblastic leukemia. The data including morphology, immunostaining, and flow cytometry analysis were collected, and we explored the problems and differential diagnosis in the diagnosis of hematopoietic cell tumors of ambiguous lineage. Results: The five cases showed that the accurate pathological diagnosis and classification of hematopoietic cell tumors of ambiguous lineage should be based on lineage-specific antigens. Moreover, tumor cells have the potential of multi-directional differentiation. In different sites or different periods, the differentiation of tumor cells may be different. Biopsy and detection of all related markers should be performed for the initial diagnosis, and the detection should be repeated when the condition of the patient changes. Combined application of multi-techniques, including morphology and flow cytometry analysis, is recommend for the diagnosis of hematopoietic cell tumors of ambiguous lineage, since the conventional morphology and immunophenotyping methods are limited. Conclusion: Hematopoietic cell tumors of ambiguous lineage are derived from hematopoietic stem cells with a potential of multi-differentiation. The differentiation of tumor cells is variable. We need to integrate cell morphology, flow cytometry, pathology, clinical data, and molecular genetics to make a comprehensive diagnosis.

[Advances of studies on the occurrence of the upper respiratory disease correlative with immunity and tobacco].

SummaryTobacco smoke exposure has obvious and complex effects on the immune system of the human upper respiratory tract, including pro-inflammatory and anti-immune effects. Exposure to tobacco smoke is closely related to the occurrence and development of allergic rhinitis, the common rhinitis and sinusitis. The innate immune system is influenced by tobacco smoking through its effects on the respiratory mucosa and its adjuncts, natural killer cells, dendritic cells, neutrophils and innate immune receptors. Cigarette smoke can also affect the humoral immunity and cellular immunity, altering the acquired immune condition of the upper respiratory tract. Tobacco smoke exposure promotes the occurrence and development of the upper respiratory tract infectious diseases and allergic diseases by changing the composition of microflora in the upper respiratory tract.

Expression of long non-coding RNA MAGI2­AS3 in human gliomas and its prognostic significance.

OBJECTIVE: It has been confirmed that the dysregulation of long noncoding RNAs (lncRNAs) is associated with various diseases, especially cancer. LncRNA MAGI2 antisense RNA 3 (MAGI2-AS3) has been reported to be involved in the progression of bladder cancer and breast cancer. In this study, we aimed to explore its expression and clinical significance in glioma. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assays were performed to detect the expression levels of MAGI2-AS3 in fresh glioma and matched adjacent normal brain tissue specimens, which were collected from 178 patients. Then the association between MAGI2-AS3 expression and clinical-pathological parameters were further evaluated using the Chi-square test. The overall survival (OS) was analyzed by the log-rank test, and the survival curves were plotted according to Kaplan-Meier. Univariate and multivariate analyses were performed to analyze the prognostic significance of MAGI2-AS3 expression. RESULTS: We found that the relative expression level of MAGI2-AS3 in glioma tissues was significantly lower than those in adjacent normal brain tissues (p<0.01). Lower MAGI2-AS3 expression was observed to be positively correlated with the World Health Organization (WHO) grade (p=0.031) and KPS score (p=0.003) in glioma patients. The Kaplan-Meier analysis indicated that patients with low MAGI2-AS3 expression levels tended to have worse overall survival than those with high levels of MAGI2-AS3 expression (p=0.0042). In the multivariate analysis, we further observed that MAGI2-AS3 expression in glioma tissues was an independent prognostic factor for overall survival (HR=3.098, 95% CI: 1.289-4.118, p=0.014). CONCLUSIONS: MAGI2-AS3 expression represents a significant favorable prognostic factor for patients with glioma.

Genome-wide association analysis reveals genomic regions on Chromosome 13 affecting litter size and candidate genes for uterine horn length in Erhualian pigs.

Litter size has a great impact on the profit of swine producers. Uterine development is an important determinant of reproduction efficiency and could hence affect litter size. Chinese Erhualian pig is one of the most prolific breeds in the world, even though large phenotypic variation in litter size was observed within Erhualian sows. To dissect the genetic basis of the phenotypic variation, we herein conducted genome-wide association studies for total number born and number born alive (NBA) of Erhualian sows. In total, one significant single nucleotide polymorphism (SNP) (P<1.78e-06) and 11 suggestive SNPs (P<3.57e-05) were identified on 10 chromosomes, confirming seven previously reported quantitative trait loci (QTL) and uncovering six QTL for litter size or uterus length. One locus on Sus scrofa chromosome (SSC) 13 (79.28 to 90.43 Mb) harbored a cluster of suggestive SNPs associated with multiparous NBA. The SNP (rs81447100) within this region was confirmed to be significantly (P<0.05) associated with litter size in Erhualian (n=313), Sutai (n=173) and Yorkshire (n=488) populations. Retinol binding protein 2 and retinol binding protein 1 functionally related to the development of uterus were located in a region of 2 Mb around rs81447100. Moreover, four genes related to embryo implantation and development were also detected around other significant SNPs. Taken together, our findings provide a potential marker (rs81447100) for the genetic improvement of litter size not only in Chinese Erhualian pigs but also in European commercial pig breeds like Yorkshire, and would facilitate the final identification of causative variant(s) underlying the effect of SSC13 QTL on litter size.

[Comparison of Criminal Characteristics in Depression Patients and Schizophrenics with Homicide Behavior].

OBJECTIVES: To explore the criminal characteristics of forensic psychiatry expertise in depression patients and schizophrenics with homicide behavior. METHODS: A total of 40 depression （depressive episode） patients and 50 schizophrenics with homicide behavior were randomly assigned into the study group and control group, respectively. Data of demographic and criminal characteristic of the two groups were collected by a self-designed questionnaire, and then were compared. RESULTS: There were no statistical differences in age, education level and career between study and control groups （P>0.05）. Compared with the control group, the victims in the study group were mainly the patient's children and parents, and most offenders had suicidal behavior after homicide （70%）. In study group, the motives of crime were mainly extended suicide and indirect suicide, and most offenders had attempted suicide （85%） and diminished capacity of criminal responsibility （70%）, which in control group had no capacity of criminal responsibility （56%）. Except for criminal site, there were statistical differences in other criminal characteristics between two groups （P<0.05）. CONCLUSIONS: There are different criminal characteristics between depression patients and schizophrenics with homicide behavior in forensic psychiatry, and these characteristics should be considered when these two diagnoses are distinguished in forensic psychiatry expertise.

[Patients of Escherichia coli bloodstream infection: analysis of antibiotic resistance and predictors of mortality].

Objective: To analyze the drug resistance of Escherichia coli (E.coli) from bloodstream infection (BSI) and the predictors of mortality in E. coli bloodstream infection (BSI). Methods: The clinical data of 139 E. coli BSI cases diagnosed from January 2012 to December 2015 in The Second Affiliated Hospital of Zhejiang University School of Medicine, Lanxi Branch (Lanxi People's Hospital), Zhejiang Province, were retrospectively analyzed. The antimicrobial susceptibility testing was performed using Vitek 2 system. Extended-spectrum beta-lactamases (ESBLs) were detected by disk diffusion confirmatory testing. The factors associated with ESBLs-producing strains were identified by univariate analysis. Multivariate analysis was used to identify independent predictors of infection mortality by applying Logistic regression. Results: 42.4% of E. coli isolates were ESBLs-producing. The resistant rate of imipenem was 0.7%. The percent of ESBLs in hospital-acquired infection was higher than that in community-acquired infection but without statistical significance (48.7% versus 40.0%, P=0.350). Univariate analysis suggested that the percent of ESBLs-producing strains in BSI happened on ≥15 d after admission and in BSI of biliary tract infection source was 76.9% and 68.0%, which were much higher than those in BSI happened on <15 d after admission and in BSI of non-biliary tract infection source (34.6% and 36.8%, P=0.013 and 0.004). The overall mortality of E. coli BSI was 13.7%. Multivariate Logistic regression analysis indicated that Sequential Organ Failure Assessment (SOFA ) score (OR=1.393, P<0.001), ceftazidime non-susceptibility (OR=4.444, P=0.018) and liver cirrhosis (OR=13.513, P=0.001) were independent risk factors of mortality. Conclusions: The frequency of ESBLs-producing E. coli was high in primary hospital of Zhejiang Province. SOFA score, ceftazidime non-susceptibility and cirrhosis were predictors of poor outcome in E. coli BSI.

[Retrospective analyses of CHOPE plus L-asparaginase regimen in treatment of T-cell lymphoma].

OBJECTIVE: To investigate prognostic factors of the T-cell non-Hodgkin's lymphoma (T-NHL), and to study the clinical efficacy of CHOPE plus L-asparaginase(L-ASP) regimen for T-NHL. METHODS: Retrospective analyses were made of 61 T-NHL patients who were treated from July 2007 to August 2013. Randomly divided into two groups CHOPE and CHOPE+L group(Based on CHOPE, added with L-ASP on the 1st, 3rd, 5th, 7th, 9th and 11th day). RESULTS: Of the 61 patients evaluatd with the median survival was 22 (3-65) months,the complete remission rate was 52.50%, the partial remission rate 29.51%, and the response rate 80.01%. The complete remission rate was 57.89%, and the patial remission rate 84.21% in CHOPE+L and the complete remission rate 43.48%, the response rate 78.26% in CHOPE, respectively (both P>0.05). The 1-, 2-, and 5-year overall survival rates were 91.0%, 87.6% and 65.7% respectively (P>0.05). But the overall survival rate in CHOPE+L was significantly higher than that in CHOPE group in extranodal NK/T-cell lymphoma, nasal type (ENKTCL) (P<0.05). The analysis of the prognostic factors indicated that ENKTCL, the outside junction lesions, and the CR rate were poor factors with statistic significance in T-NHL. CONCLUSION: CHOPE+L regimen has better efficacy for ENKTCL, but whether CHOPE+L regimen is used in the treatment of T-NHL, large prospective clinical trials are worth for further investigation.

[Early immune reconstitution after hematopoietic stem cell transplantation].

OBJECTIVE: To search for differences in early immune reconstitution after allogenic or autologous hematopoietic stem cell transplantation (HSCT). METHODS: The peripheral blood (PB) from 31 adult patients undergoing allogenic HSCT (allo-HSCT, 15 patients) or autologous HSCT (auto-HSCT, 16 patients) for the treatment of hematological malignancies and from 20 related healthy controls (HC) from December 2011 to August 2014 was used to analyze the kinetic recovery of lymphocyte subsets by means of flow cytometry during 12 months after HSCT. The T cell receptor rearrangement excision circle (TREC) levels among CD3(+) T cells were measured in the patients and HC to evaluate the thymic-dependent T cell reconstitution. RESULTS: The allo- and auto-HSCT recipients did not differ significantly in CD4(+) T cells, CD8 naive T cells, effecter memory T cells (TEM), CD4 central memory T cells (TCM), mid-activated T cells and dendritic cells (DC)during the follow-up (P>0.05). But they both differed significantly from HC (P<0.05). CD8(+) T cells and NK cells reconstructed rapidly. There was no significant difference in the numbers of B cells between the allo- and auto-HSCT groups from M1 to M3 (P>0.05). B cells in both the groups were lower than those in HC (P<0.05). The recovery of B cells in auto-HSCT group was faster than in allo-HSCT group at M6 and M12 (P<0.05). The frequencies of CD4 naive T cells and later activated T cells in allo-HSCT group were significantly higher than in auto-HSCT group at M6 and M12 (P<0.05). The frequencies of CD8 TCM in auto-HSCT group were significantly higher than in allo-HSCT group at M6 and M12 (P<0.05). The TREC levels were significantly lower than in both the groups compared with the age-matched HC during the follow-up (P<0.05). No significant difference was observed between allo-HSCT and auto-HSCT groups (P>0.05). CONCLUSION: The differences of the nature and the speed of lymphocyte reconstitution observed between the two patents groups were minor. This leads us to conclude that in allografted patients, immune reconstitution and subpopulations of peripheral blood lymphocytes are probably not related to the allogenicity of the graft, but due to the impaired thymus functions and slow differentiation of T lymphocytes in thymus.

Pharmacokinetics of cefozopran by single and multiple intravenous infusions in healthy Chinese volunteers.

BACKGROUND AND OBJECTIVES: Cefozopran is a parenteral cephalosporin with a broad spectrum of activity against Gram-positive and Gram-negative bacteria. The objective of this study was to evaluate the pharmacokinetics of cefozopran after single- and multiple-dose intravenous administration in healthy subjects, to provide clinical guidance in its application. METHODS: This was a single-center, open-label, randomized, two-phase study conducted in 12 subjects. In the single-dose phase, subjects were randomly assigned to receive single doses of 0.5, 1.0 and 2.0 g of injected cefozopran hydrochloride in a three-way crossover design with a 5-day washout period between administrations. In the multiple-dose phase, subjects received 2.0 g every 12 h for 4 days. Plasma and urine pharmacokinetic samples were assayed by a validated high-performance liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated and analyzed statistically. Safety assessments were conducted throughout the study. RESULTS: Twelve healthy volunteers (six males and six females) were enrolled and completed the study. Following a single 1-h intravenous infusion of 0.5, 1.0 or 2.0 g cefozopran, maximum plasma concentration (C max) and area under the plasma concentration-time curve from time zero to the time of the last measurable concentration (AUClast) increased in a dose-proportional manner. The mean half-life in plasma (t ½) was in the range of 1.20-2.80 h. Cefozopran was mainly excreted in its unchanged form, with no tendency for accumulation, via the kidney, and varied from 65.99 to 73.33 %. No appreciable accumulation of either drug occurred with multiple intravenous doses of cefozopran, and pharmacokinetic parameters for cefozopran were similar on days 1 and 4. No serious adverse events were reported. Adverse events were generally mild. CONCLUSION: Cefozopran was safe and well tolerated in the volunteers and displayed linear increases in the C max and AUClast values.

Intracellular ASIC1a regulates mitochondrial permeability transition-dependent neuronal death.

Acid-sensing ion channel 1a (ASIC1a) is the key proton receptor in nervous systems, mediating acidosis-induced neuronal injury in many neurological disorders, such as ischemic stroke. Up to now, functional ASIC1a has been found exclusively on the plasma membrane. Here, we show that ASIC1a proteins are also present in mitochondria of mouse cortical neurons where they are physically associated with adenine nucleotide translocase. Moreover, purified mitochondria from ASIC1a(-/-) mice exhibit significantly enhanced Ca(2+) retention capacity and accelerated Ca(2+) uptake rate. When challenged with hydrogen peroxide (H2O2), ASIC1a(-/-) neurons are resistant to cytochrome c release and inner mitochondrial membrane depolarization, suggesting an impairment of mitochondrial permeability transition (MPT) due to ASIC1a deletion. Consistently, H2O2-induced neuronal death, which is MPT dependent, is reduced in ASIC1a(-/-) neurons. Additionally, significant increases in mitochondrial size and oxidative stress levels are detected in ASIC1a(-/-) mouse brain, which also displays marked changes (>2-fold) in the expression of mitochondrial proteins closely related to reactive oxygen species signal pathways, as revealed by two-dimensional difference gel electrophoresis followed by mass spectrometry analysis. Our data suggest that mitochondrial ASIC1a may serve as an important regulator of MPT pores, which contributes to oxidative neuronal cell death.

2-Aminoethoxydiphenyl borate as a common activator of TRPV1, TRPV2, and TRPV3 channels.

2-Aminoethoxydiphenyl borate (2APB) had been depicted as a universal blocker of transient receptor potential (TRP) channels. While evidence has accumulated showing that some TRP channels are indeed inhibited by 2APB, especially in heterologous expression systems, there are other TRP channels that are unaffected or affected very little by this compound. More interestingly, the thermosensitive TRPV1, TRPV2, and TRPV3 channels are activated by 2APB. This has been demonstrated both in heterologous systems and in native tissues that express these channels. A number of 2APB analogs have been examined for their effects on native store-operated channels and heterologously expressed TRPV3. These studies revealed a complex mechanism of action for 2APB and its analogs on ion channels. In this review, we have summarized the current results on 2APB-induced activation of TRPV1-3 and discussed the potential mechanisms by which 2APB may regulate TRP channels.

Activation of extracellular signal-regulated kinase by TGF-beta1 via TbetaRII and Smad7 dependent mechanisms in human bronchial epithelial BEP2D cells.

Transforming growth factor-beta1 (TGF-beta1) can activate mitogen-activated protein kinases (MAPKs) in many types of cells. The mechanism of this activation is not well elucidated. Here, we explore the role of TGF-beta/Smads signaling compounds in TGF-beta1-mediated activation of extracellular signal-regulated kinase (ERK) MAPK in human papillomavirus (HPV)-18 immortalized human bronchial epithelial cell line BEP2D and the role of TGF-beta1-induced phosphorylation of ERK in proliferation and apoptosis of BEP2D. The cell models of siRNA-mediated silencing of TGF-beta receptor type II (TbetaRII), Smad2, Smad3, Smad4, and Smad7 were employed in this study. Our results demonstrate that TGF-beta1 activates ERK in a time-dependent manner with a maximum effect at 60 min; overexpression of Smad7 increased this TGF-beta1-mediated phosphorylation of the ERK; and siRNA-mediated silencing of TbetaRII, Smad3, Smad4, and Smad7 abrogated this effect. Moreover, we observed that overexpression of Smad7 restored TGF-beta1-mediated ERK phosphorylation in Smad4 knockdown cells but not in TbetaRII knockdown cells. In BEP2D cells, TGF-beta1 treatment effectively inhibited cells' proliferation and induced their apoptosis. Pretreatment with U0126, an inhibitor of ERK1/2, significantly enhanced the TGF-beta1-mediated antiproliferative and apoptosis induction effects in BEP2D cells. These data revealed that TbetaRII and Smad7 play the critical roles in TGF-beta1-mediated activation of ERK; Smad3 and Smad4 can play an indirect role through up-regulating Smad7 expression; and TGF-beta1-induced phosphorylation of ERK may participate in BEP2D cell proliferation and apoptosis regulation.

The P2Y purinergic receptor expressed by enteric neurones in guinea-pig intestine.

Electrophysiological recording methods provided evidence for presynaptic release of ATP from enteric neurones and postganglionic sympathetic fibres in the enteric nervous system (ENS) of guinea-pig intestine (J Physiol Lond 2003; 550: 493-504). The released ATP acted at postsynaptic P2Y(1) receptors to evoke slow synaptic excitation in neurones in the submucosal division of the ENS. Here, we report the cloning and characterization of the P2Y(1) receptor, which was found in the guinea-pig submucosal layer. A 1178 bp cDNA clone was isolated from guinea-pig submucosal RNA by reverse transcription polymerase chain reaction (RT-PCR). The cDNA contained an open-reading frame of 1119 bp, encoding a 373 amino acid polypeptide of the same length and with 95% identity to the human P2Y(1) receptor. Stable expression of the guinea-pig cDNA in human embryonic kidney (HEK)293 cells was accompanied by a marked increase in sensitivity for elevation of free intracellular calcium evoked by ATP or related nucleotides. The potency order for ATP and its analogues was: 2-methio-adenosine diphosphate > 2-methio-adenosine triphosphate > ADP > ATP-gamma-S > ATP. The selective P2Y(1) receptor antagonist, MRS2179, was a competitive antagonist for the receptor with a pA(2) value of 6.5. The results add to existing evidence for expression of a functional P2Y(1) purinergic receptor in neurones of the submucosal division of the ENS.

Slow excitatory synaptic transmission mediated by P2Y1 receptors in the guinea-pig enteric nervous system.

Electrophysiological recording was used to study a type of slow excitatory postsynaptic potential (slow EPSP) that was mediated by release of ATP and its action at P2Y1 receptors on morphologically identified neurones in the submucosal plexus of guinea-pig small intestine. MRS2179, a selective P2Y1 purinergic receptor antagonist, blocked both the slow EPSP and mimicry of the EPSP by exogenously applied ATP. Increased conductance accounted for the depolarization phase of the EPSP, which occurred exclusively in neurones with S-type electrophysiological behaviour and uniaxonal morphology. The purinergic excitatory input to the submucosal neurones came from neighbouring neurones in the same plexus, from neurones in the myenteric plexus and from sympathetic postganglionic neurones. ATP-mediated EPSPs occurred coincident with fast nicotinic synaptic potentials evoked by the myenteric projections and with noradrenergic IPSPs evoked by sympathetic fibres that innervated the same neurones. The P2Y1 receptor on the neurones was identified as a metabotropic receptor linked to activation of phospholipase C, synthesis of inositol 1,4,5-trisphosphate and mobilization of Ca2+ from intracellular stores.