Histologic subtypes of non-muscle invasive bladder cancer

The majority of bladder cancers(BCs)are non-muscle invasive BCs(NMIBCs)and show the morphology of a conventional urothelial carcinoma(UC).Aberrant morphology is rare but can be observed.The classification and characterization of histologic subtypes(HS)in UC in BC have mainly been described in muscle in-vasive bladder cancer(MIBC).However,the currently used classification is ap-plied for invasive urothelial neoplasm and therefore,also valid for a subset of NMIBC.The standard transurethral diagnostic work-up misses the presence of HS in NMIBC in a considerable percentage of patients and the real prevalence is not known.HS in NMIBC are associated with an aggressive phenotype.Conse-quently,clinical guidelines categorize HS of NMIBC as“(very)high-risk”tumors and recommend offering radical cystectomy to these patients.Alternative strategies for bladder preservation can only be offered to highly selected patients and ideally within clinical trials.Novel treatment strategies and biomarkers have been established MIBC and NMIBC but have not been comprehensively invest-igated in the context of HS in NMIBC.Further evaluation prior to implementation into clinical practice is needed.

Influence of Angiotensin II on α1-Adrenergic Receptors Function in Rat Aorta and Expression in Vascular Smooth Muscle Cells

Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT1 and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α1-adrenergic receptors (α1-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10−5 M), and in some experiments, 5-Methylurapidil (α1A-AR antagonist), AH11110A (α1B-AR antagonist), or BMY-7378 (α1D-AR antagonist), were used to identify the α1-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α1D-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α1-ARs proteins were evaluated. α1D-AR increased at 30 and 60 min post Ang II exposure, the α1A-AR diminished from 1 to 4 h, while α1B-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α1D-AR at short times, and BMY-7378 protected α1D-AR from desensitization.

MicroRNA-146a Promotes Embryonic Stem Cell Differentiation towards Vascular Smooth Muscle Cells through Regulation of Kruppel-like Factor 4

Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs.

Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs

AIM: To investigate the effect of rhubarb on contractile response of isolated gallbladder muscle strips from guinea pigs and its mechanism.METHODS: Guinea pigs were killed to remove the whole gallbladder. Two or three smooth muscle strips (8 mm×3mm) were cut along the longitudinal direction. The mucosa on each strip was carefully removed. Each longitudinal muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution (37 ℃), bubbled continuously with 950 mL/L O2 and 50 mL/L CO2. The resting tension (g), mean contractile amplitude (mm),and contractile frequency (waves/min) were simultaneously recorded on recorders. After 2-h equilibration, rhubarb (10, 20, 70, 200, 700, 1 000 g/L) was added cumulatively to the tissue chamber in turns every 2 min to observe their effects on gallbladder.Antagonists were given 3 min before administration of rhubarb to investigate the possible mechanism.RESULTS: Rhubarb increased the resting tension (from 0 to 0.40±0.02, P＜0.001), and decreased the mean contractile amplitude (from 5.22±0.71 to 2.73±0.41,P＜0.001). It also increased the contractile frequency of the gallbladder muscle strips in guinea pigs (from 4.09±0.46to 6.08±0.35, P＜0.001). The stimulation of rhubarb on the resting tension decreased from 3.98±0.22 to 1.58±0.12by atropine (P＜0.001), from3.98±0.22 to 2.09±0.19 by verapamil (P＜0.001) and from 3.98±0.22 to 2.67±0.43by phentolamine (P＜0.005). But the effect was not inhibited by hexamethonium (P＞0.05). In addition, the action of mean amplitude and frequency was not inhibited by the above antagonists.CONCLUSION: Rhubarb can stimulate the motility of isolated gallbladder muscle strips from guinea pigs. The stimulation of rhubarb might be relevant with M receptor,Ca2+ channel and α receptor partly.

Semaphorin 7A promotes human vascular smooth muscle cell proliferation and migration through theβ-catenin signaling pathway

Background:Vascular smooth muscle cells(VSMCs)undergo a conversion from a contractile phenotype to a proliferative synthetic phenotype,contributing to the pathogenesis of cardiovascular diseases.Semaphorin 7A(SEMA7A)is a glycosylphosphatidylinositol-anchored membrane protein that plays an important role in vascular homeostasis by regulating endothelial cell behaviors.However,the expression and role of SEMA7A in VSMCs remain unclear.Methods:In this study,we screened for VSMC-regulating genes in publicly available datasets and analyzed the expression of SEMA7A in human coronary artery smooth muscle cells(hCASMCs)treated with platelet-derived growth factor-BB(PDGF-BB).The effects of SEMA7A overexpression and knockdown on hCASMC proliferation and migration were examined.The signaling pathways involved in the action of SEMA7A in hCASMCs were determined.Results:Bioinformatic analysis showed that SEMA7A was significantly dysregulated in VSMCs treated with oxidized low-density lipoprotein or overexpressing progerin,a pro-atherogenic gene.The PDGF-BB stimulation led to a concentration-and time-dependent induction of SEMA7A.Depletion of SEMA7A attenuated PDGF-BB-induced hCASMC proliferation and migration.Conversely,overexpression of SEMA7A enhanced hCASMC proliferation and migration.Mechanistically,SEMA7A stimulated the activation of theβ-catenin pathway and upregulated c-Myc,CCND1,and MMP7.Knockdown ofβ-catenin impaired SEMA7A-induced hCASMC proliferation and migration.Conclusions:SEMA7A triggers phenotype switching in VSMCs through theβ-catenin signaling pathway and may serve as a potential therapeutic target for cardiovascular diseases.

Inhibitory Effect of PPARδAgonist GW501516 on Proliferation of Hypoxia-induced Pulmonary Arterial Smooth Muscle Cells by Regulating the mTOR Pathway

Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.Methods PASMCs were incubated with different concentrations of GW501516(10,30,100 nmol/L)under the hypoxic condition.The proliferation was determined by a CCK-8 assay.The cell cycle progression was analyzed by flow cytometry.The expression of PPARδ,S phase kinase-associated protein 2(Skp2),and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting.Then PASMCs were treated with 100 nmol/L GW501516,100 nmol/L mammalian target of rapamycin(mTOR)inhibitor rapamycin and/or 2µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.Results The presented data demonstrated that hypoxia reduced the expression of PPARδin an oxygen concentration-and time-dependent manner,and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle.In accordance with these findings,GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs.Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation,arresting the cell cycle,regulating the expression of Skp2 and p27,and inactivating mTOR in hypoxia-exposed PASMCs.Moreover,MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.Conclusion GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway.

Actions of genistein on contractile response of smooth muscle isolated from guinea pig gallbladder

BACKGROUND: Defective contractile motility of the gallbladder is an important factor for gallstone formation. Estrogen might increase the risk of gallstones and cholecystitis, and estradiol inhibits the contractile activity of isolated strips of guinea pig gallbladder. The potential risks associated with hormone replacement therapy (HRT) include symptomatic gallstones. Phytoestrogen have been used to treat menopause syndromes by replacing traditional estrogen. This experiment aimed to determine the effects of the phytoestrogen genistein on the contractile response of smooth muscle strips isolated from guinea pig gallbladder and its possible mechanism of action. METHODS: Guinea pigs were sacrificed to remove the whole gallbladder. Two or three smooth muscle strips were cut longitudinally. Each strip was suspended in a tissue chamber containing Krebs solution. After 2 hours of equilibration, contractile response indexes were recorded. Different concentrations of genistein were added to the chamber and the contractile responses were measured. Each antagonist was added 2 minutes before genistein to study possible mechanisms. The effect of genistein on calcium-dependent contraction curves and biphasic contraction in calcium-free Krebs solution were measured. RESULTS: Genistein decreased the resting tension dose-dependently, and reduced the mean contractile amplitude and frequency in gallbladder strips. Ranitidine partly inhibited the effect of genistein, but methylene blue, N(omega)-nitro-L-arginine, and propranolol hydrochloride did not influence this action. Genistein had no significant effects on calcium-dependent contraction. Genistein reduced the first contraction induced by acetylcholine chloride, but did not affect the second contraction caused by CaCl(2). CONCLUSIONS: Genistein relaxed smooth muscle isolated from the gallbladder of guinea pigs and this might contribute to the formation of gallstones. The inhibitory action might be related to H(2) receptors and the release of intracellular Ca(2+) from sarcoplasmic reticulum. Replacing traditional estrogen with phytoestrogen to treat menopause syndromes may increase the risk of gallstone formation.

NR4A1 enhances glycolysis in hypoxia-exposed pulmonary artery smooth muscle cells by upregulating HIF-1αexpression

Background:Pulmonary arterial hypertension(PAH)is a chronic and progressive disease that is strongly associated with dysregulation of glucose metabolism.Alterations in nuclear receptor subfamily 4 group A member 1(NR4A1)activity alter the outcome of PAH.This study aimed to investigate the effects of NR4A1 on glycolysis in PAH and its underlying mechanisms.Methods:This study included twenty healthy volunteers and twenty-three PAH patients,and plasma samples were collected from the participants.To mimic the conditions of PAH in vitro,a hypoxia-induced model of pulmonary artery smooth muscle cell(PASMC)model was established.The proliferation of PASMCs was assessed using CCK8 assays.Results:Levels of NR4A1,hypoxia-inducible factor-1α(HIF-1α),and various glycolysis-related enzymes were measured.In addition,extracellular glucose and lactate production were assessed.The interaction between NR4A1 and HIF-1αwas evaluated by co-immunoprecipitation assays.Levels of NR4A1 and HIF-1αwas increased in PAH patients,and exposure to hypoxia resulted in increased levels of NR4A1 and HIF-1αin PASMCs.NR4A1 interacted with HIF-1α.NR4A1 overexpression enhanced hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,decreased glucose levels,increased lactate levels and promoted hypoxic PASMC viability.Conversely,silencing NR4A1 decreased hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,promoted glucose production,reduced lactate levels and inhibited hypoxic PASMC viability.Furthermore,overexpression of HIF-1αreversed the regulation of glycolysis caused by NR4A1 knockdown.Conclusion:NR4A1 enhances glycolysis in hypoxia-induced PASMCs by upregulating HIF-1α.Our findings indicate that the management of NR4A1 activity may be a promising strategy for PAH therapy.

A bioinformatics-based study of the mechanism of JQ-1 on BET protein and atherosclerosis induced by vascular smooth muscle cell proliferation

Background:Based on previous theoretical studies,JQ-1 as a common inhibitor of bromodomain and extraterminal(BET)proteins was used to treat a variety of diseases.Therefore,we aimed to explore the mechanism of action of JQ-1 on BET proteins based on bioinformatics and build the novel hypothesis of JQ-1 in treating atherosclerosis(AS)caused by proliferation of vascular smooth muscle cells(VSMCs).Methods:We selected the chip GSE138323 which was searched with the key words“Vascular smooth muscle cell proliferation”in Gene Expression Omnibus(GEO)database,and differential gene analysis was performed between the GRO and JQ-1 groups.Then the top twenty significantly up-regulated genes and the top twenty significantly down-regulated genes were selected for Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis.Thirdly,structured the PPI network of forty differential genes,and the core genes were screened by using the MCC algorithm which in“Cytohubba”plugin in the Cytoscapev3.9.1 software.After that,single gene Gene Set Enrichment Analysis(GSEA)enrichment analysis was performed on the selected core genes in R language.Finally molecular docking validation was performed.Results:Five core genes was selected:H3C2,H3C4,H3C7,H3C10 and AREG.The GO enrichment analysis results showed that there were twenty-five entries in biological process,eight entries in cellular components(CC),and twenty-five entries in molecular function.The KEGG enrichment analysis results showed that there were seven pathways,mainly including systemic lupus erythematosus and external neutrophil trap formation.The GSEA results showed that the five genes were mainly through the regulation of cytochrome P450 metabolism,PPAR signaling pathway and other pathways.The molecular docking results showed that JQ-1 had binding activity with these five genes.Conclusions:JQ-1 may regulate the expression of the genes that H3C2,H3C4,H3C7,H3C10 and AREG,to mainly regulate the genes in cytochrome P450 metabolism,PPAR singling pathway and other pathways,to make some influence in the proliferation of VSMCs,and improved atherosclerotic symptoms due to vascular smooth muscle proliferation,thus treating cardiovascular disease.

Effect of Fructus Psoraleae on motility of gallbladder isolated smooth muscle strips from guinea pigs

AIM： To observe the effect of Fructus Psoraleae on motility of isolated gallbladder muscle strips of guinea pigs and its mechanism. METHODS： Guinea pigs were hit to lose consciousness and the whole gallbladder was removed quickly. Two or three smooth muscle strips （8 mm×3mm） were cut along a longitudinal direction. The mucosa was gently removed. Every longitudinal muscle strip was suspended in a tissue chamber which was continuously perfused with 5 mL Krebs solution （37℃）, pH 7.4, and aerated with 950 mL/L 02 and 50 mL/L CO2. The isometric response was recorded with an ink-writing recorder. After 2 h equilibration under i g-load, 50 μL Fructus Psoraleae （10, 20, 70, 200, 700, 1000 g/L） was added cumulatively into the tissue chamber in turn every 2 rain to observe their effects on gallbladder muscle strips （cumulating final concentration of Fructus Psoraleae was 0.1, 0.3, 1.0, 3.0, 10.0, 20.0 g/L）. The antagonists, including 4-DAMP, benzhydramine, hexamethonium, phentolamine, verapamil and idomethine were given 2 min before Fructus Psoraleae respectively to investigate the mechanisms involved. RESULTS： Fructus Psoraleae dose-dependently increased the resting tension （r=0.992, P〈0.001）, decreased the mean contractile amplitude （r=0.970, P〈0.001） and meanwhile increased the contractile frequency of the gallbladder muscle strip in vitro （r=0.965, P〈0.001）. The exciting action of Fructus Psoraleae on the resting tension could be partially blocked by 4-DAMP （the resting tension decreased from 1.37 ± 0.41 to 0.70 ± 0.35, P〈0.001）, benzhydramine （from 1.37 ±0.41 to 0.45±0.38, P〈0.001）, hexamethonium （from 1.37 ± 0.41 to 0.94 ± 0.23, P〈0.05）, phentolamine （ from 1.37±0.41 to 0.89±0.22, P〈0.01） and verapamil （from 1.37±0.41 to 0.94±0.26, P〈0.05）. But the above antagonists had no significant effect on the action of Fructus Psoraleae-induced mean contractile amplitude （P〉0.05）. Moreover, the increase of the contractile frequency due to Fructus Psoraleae was inhibited by 4-DAMP （decreased from 8.3 ± 1.2 to 6.8 ± 0.5, P 〈 0.01） and hexamethonium （from 8.3 ±1.2 to 7.0 ± 0.9, P 〈 0.05）. Idomethine had no significant effect on the Fructus Psoraleae- induced responses （P〉 0.05）. CONCLUSION： Fructus Psoraleae enhances the motility of isolated gallbladder muscle strips from guinea pigs, in a dose-dependent manner. The effect of Fructus Psoraleae is partly related to M3, N receptor, α receptor, H1 receptor, Ca^2＋ channel, but not related to prostaglandin.

Overexpression of heme oxygenase-1 protects smooth muscle cells against oxidative injury and inhibits cell proliferation

To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we established an in vitro transfection of human HO-1 gene into rat VSMC mediated by a retroviral vector. The results showed that the profound expression of HO-1 protein as well as HO activity was 1.8- and 2.0-fold increased respectively in the transfected cells compared to the non-transfected ones. The treatment of VSMC with different concentrations of H2O2 led to the remarkable cell damage as indicated by survival rate and LDH leakage. However, the resistance of the HO-1 transfected VSMC against H2O2 was significantly raised. This protective effect was dramatically diminished when the transfected VSMC were pretreated with ZnPP-IX, a specific inhibitor of HO, for 24 h. In addition, we found that the growth potential of the transfected cells was significantly inhibited directly by increased activity of HO-1, and this effect might be related to decreased phosphorylation of MAPK. These results suggest that the overexpression of introduced hHO-1 is potentially able to reduce the risk factors of atherosclerosis, partially due to its cellular protection against oxidative injury and to its inhibitory effect on cellular proliferation.

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

BACKGROUND Computed tomography(CT)technology has been gradually used in the differen-tiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.AIM To explore the value of enhanced CT in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.METHODS Clinical data of patients with gastric mesenchymal or gastric smooth muscle tu-mours who were treated in our hospital from May 2018 to April 2023 were retrospectively analysed.Patients were divided into the gastric mesenchymal tumor group and the gastric smooth muscle tumor group respectively(n=50 cases per group).Clinical data of 50 healthy volunteers who received physical examinations in our hospital during the same period were selected and included in the control group.Serum levels of carcinoembryonic antigen(CEA),alpha-fetoprotein(AFP),carbohydrate antigen 19-9(CA19-9),CA-125 and cytokeratin 19 fragment antigen 21-1 were compared among the three groups.The value of CEA and CA19-9 in the identification of gastric mesenchymal tumours was analysed using the receiver operating characteristic(ROC)curve.The Kappa statistic was used to analyse the consistency of the combined CEA and CA19-9 test in identi-fying gastric mesenchymal tumours.RESULTS CEA levels varied among the three groups in the following order:The gastric mesenchymal tumour group>the control group>the gastric smooth muscle tumour group.CA19-9 levels varied among the three groups in the following order:The gastric mesenchymal group>the gastric smooth muscle group>the control group,the difference was statistically significant(P<0.05).ROC analysis showed that the area under the curve of CEA and CA19-9 was 0.879 and 0.782,respectively.CONCLUSION Enhanced CT has shown value in differentiating small mesenchymal tumors of the stomach and intestines from smooth muscle tumors.

Effects and its possible mechanism of Radix Saposhnikoviae on rat colonic smooth muscle in vitro

Objective： To determine the effect of different concentrations of Radix Saposhnikoviae （RS） on the contraction of smooth muscle strips and the Ca2＋ mobilization of cultured smooth muscle ceils of rat colon and its possible mechanism of action. Methods： Strips of rat colon longitudinal muscle were prepared and smooth muscle cells from rat colon were isolated and cultured. In the experiments, in vitro muscle strips were suspended in an organ bath and the contraction of the strips was recorded. In the cell- experiments, intracellular Ca2＋ was assessed using fluorescent intensity （FI） of smooth muscle cells loaded with Fluo-4/AM, measured with a laser scanning confocal microscope and related software. Results： In the in vitro experiment, RS （0.02, 0.2, 2, 20 g/L） inhibited contraction of muscle strips in a concentration-dependent manner, and this inhibition was significant for the three higher RS concentrations （P 〈 0.01） for both Peak （the maximal contraction amplitude） and Area （the area under curves）. Similarly, RS inhibited Ach-induced contraction. In these experiments the inhibition of the Peak values in the RS 2 and 20 g/L groups was significant （P 〈 0.01）, as was the inhibition of the Area values in all RS groups （P 〈 0.05）. Naloxone and propranolol did not significantly affect the inhibitory effect of RS on smooth muscle contractility, while phentolamine significantly reduced the inhibitory effect （P 〈 0.01）. In experiments using primary smooth muscle cell cultures in Ca2＋ - containing buffer, the post-treatment fluorescence of cells in the RS 0.2, 2 and 20 g/L groups differed significantly from pre-treatment values （P 〈 0.05）, and the percent inhibition of fluorescence in the RS 2 g/L and 20 g/L groups was significant （P 〈 0.01）. However, in Ca2＋-free buffer, FS had no significant effect on cell fluorescence. Conclusion： RS inhibited both the spontaneous and Ach-stimulated contraction of rat colonic smooth muscle strips. This RS effect appeared to involve α -adrenoceptors, but not β -adrenoceptors or opioid receptors. In cultured primary smooth muscle cells, RS reduced the mobilization of Ca2＋ from extracellular sources, but may had no effect on the release of Ca2＋ from sarcoplasmic reticulum and endoplasmic reticulum.

Morphological Characteristics of Smooth Muscle Cells Isolated from the Rat Ductus Deferens

The aim of this study was to establish a method of isolating and culturing smooth muscle cells from the ductus deferens of rats. Smooth muscle cells were prepared from ductus deferens by explanting technique after dissection of adventitia and intimae, and cultured in vitro. The identification of the smooth muscle cells were verified by using anti u-smooth muscle actin （a-SMA） immunohistochemistry studies. The result suggested that the cells are multi-morphous, showing long fusiform or star shapes. The apophysis of cells contacted and coalesced to each other, in some regions the cells overlapped in multilayer, while in the other regions they formed monolayer that fluctuated and showed a ＂peak-valley＂ shape. They presented a positive reaction through immunohistochemistry studies. The purity of the cells was more than 99% through this method. The culturing of smooth muscle cells by explanting technique is simple and stable.

Urocortin, the neuropeptide, inhibits the viability of ECV304 cells and rat vascular smooth muscle cells

Objective: This study aims to investigate the effects of urocortin (Ucn) on the viability of endothelial cells (ECV304) and rat vascular muscle cells (VSMC). Methods: Rat aortic VSMC were isolated from the rats' thoracic aorta. We studied the effect of Ucn on the viability of ECV304 cells and VSMC by using a tetrazolium (MTT) assay.Results: Ucn (10 -7 mol/L) inhibited the viability of ECV304 cells and VSMC. Inhibition rates are 13% and 15%, respectively(P<0.05, compared with Control). This inhibition was not dependent on the affecting time and was not affected by the addition of ATP-sensitive potassium channel (KATP channel) blocker, glybenclamide (Gly, 10 mol/L). Conclusion: Ucn inhibits the viability of ECV304 and VSMC. Our results suggest that Ucn may be a new vasoactive agent and may have a beneficial effect in the process of vascular remodeling (VR).

Epstein-Barr virus-associated smooth muscle tumors in immunocompromised patients:Six case reports

BACKGROUND Epstein-Barr virus associated smooth muscle tumor(EBV-SMT)is a rare oncological entity.However,there is an increasing incidence of EBV-SMTs,as the frequency of organ transplantation and immunosuppression grows.EBV-SMT diagnosis relies on histopathology and immunochemical staining to distinguish it from post-transplant lymphoproliferative disorder(PTLD).There is no clear consensus on the treatment of EBV-SMTs.However,surgical resection,chemotherapy,radiation therapy,and immunosuppression reduction have been explored with varying degrees of success.CASE SUMMARY Our case series includes six cases of EBV-SMTs across different age groups,with different treatment modalities,adding to the limited existing literature on this rare tumor.The median latency time between immunosuppression and disease diagnosis is four years.EBV-SMTs present with variable degrees of aggressiveness and seem to have worse clinical outcomes in patients with tumor multiplicity and worse immunocompetency.CONCLUSION It is imperative to continue building on this knowledge and keeping EBV-SMTs on the differential in immunocompromised individuals.

Mechanisms mediating cholinergic antral circular smooth muscle contraction in rats

AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.

Effects of Tetrandrine on Cytosolic Free Calcium in Cultured Bovine Aortic Smooth Muscle Cells

\ The effects of tetrandrine (Tet) on cytosolic free calcium ([Ca2+]i) in subcultured bovine aortic smooth muscle cells (SMC) were studied by Fura2 and ARCMMIC cation measurement system. Tet (1～100 μmol·L-1) had no effect on the resting [Ca2+]i, but had inhibitory effects on [Ca2+]i elevation induced by high K+, 5HT, ATP, Ang II and NE in the presence of extracellular Ca2+. High concentration of Tet also inhibited Pheinduced [Ca2+]i elevation in absence of extracellular Ca2+. Tet (1～100 μmol·L-1) inhibited KCl (60 mmol·L-1) induced [Ca2+]i elevation in dosedependent manner, the IC50 value was 9.2 (95% confidence limits: 5.7～14.9) mmol·L-1. The results suggested that Tet had blocking effects on both VOC and ROC in bovine aortic SMC. It appears that the mechanisms of blocking effect of Tet on ROC might be primarily due to its Ca2+ entry blocking effects.

Mechanisms simultaneously regulate smooth muscle proliferation and differentiation

Vascular smooth muscle cell （VSMC） differentiation and proliferation are two important physiological proc- esses during vascular development. The phenotypic alteration from differentiated to proliferative VSMC contrib- utes to the development of several major cardiovascular diseases including atherosclerosis, hypertension, resteno- sis after angioplasty or bypass, diabetic vascular complications, and transplantation arteriopathy. Since the VSMC phenotype in these pathological conditions resembles that of developing VSMC during embryonic development, understanding of the molecular mechanisms that control VSMC differentiation will provide fundamental insights into the pathological processes of these cardiovascular diseases. Although VSMC differentiation is usually ac- companied by an irreversible cell cycle exit, VSMC proliferation and differentiation occur concurrently during embryonic development. The molecular mechanisms simultaneously regulating these two processes, however, remain largely unknown. Our recent study demonstrates that cell division cycle 7, a key regulator of cell cycle, promotes both VSMC differentiation and proliferation through different mechanisms during the initial phase of VSMC differentiation. Conversely, Kriappel-like factor 4 appears to be a repressor for both VSMC differentia- tion and proliferation. This review attempts to highlight the novel role of cell division cycle 7 in TGF-β-induced VSMC differentiation and proliferation. The role of K141ppel-like factor 4 in suppressing these two processes will also be discussed.

Effect of tankyrase 1 on autophagy in the corpus cavernosum smooth muscle cells from ageing rats with erectile dysfunction and its potential mechanism

This study compared tankyrase 1 expression and autophagy quantity between erectile dysfunction （ED） and non-ED rats＇ corpus cavernosum smooth muscle cells （CSMCs）. This study aslo explored the effect and possible mechanism of tankyrase 1 on autophagy and cell proliferation in ageing ED rats＇ CSMCs. The intracavernous pres- sure and mean systemic arterial pressure were measured to investigate erectile function so that eight 24-month-old ED and eight 8-month-old male Wistar rats were choosed respectively. The rat CSMCs were isolated and cultured by enzyme digestion, in which tankyrase 1 expression and autophagy quantity were compared. Tankyrase 1 over-expression was induced with plasmid transfection by Lipofectamine^TM. The effect of tankyrase 1 overexpression on proliferation, autophagy and mTOR pathway in 24-month-old ED rats＇ CSMCs was measured by the cell growth curve in MTT assay, cell cycle analysis in flow cytometry （FCM）, key protein expression in Western blot, autophagy quantity in transmission electron microscopy, monodansylcadaverine staining and GFP-LC3 fluorescence. The primary CSMCs were confirmed by immunofluorescence, and the purity was 99.1% in FCM. Compared with that of 8-month-old rats, tankyrase 1 expression and autophagy quantity significantly decreased in 24-month-old ED rats＇ primary CSMCs （P 〈 0.01）. Tankyrase 1 overexpression significantly increased the growth rate （P 〈 0.05） and increased the S phase of cell cycle （P 〈 0.01）. The autophagosome quantity was remarkably increased （P 〈 0.01）, LC3-Ⅰ/Ⅱ and Beclin 1 were upregulated （P 〈 0.01 and P 〈 0.05）, and p-p70S6K （Thr389） was downregulated in 24-month-old ED rat CSMCs （P 〈 0.05）. In conclusion, Tankyrase 1 and autophagy decrease in the CSMCs from aging rats with ED, and tankyrase 1 may have a positive effect on proliferation by enhancing autophagy and regulating the mTOR signalling pathway.