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

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

Cloning of Encoding Sequences for Chemokine Receptors CXCR4 and CCR5 from a Chinese Lymphocyte cDNAs

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Transient receptor potential channels as predictive marker and potential indicator of chemoresistance in colon cancer

Transient receptor potential(TRP)channels are strongly associated with colon cancer development and progression.This study leveraged a multivariate Cox regression model on publicly available datasets to construct a TRP channels-associated gene signature,with further validation of signature in real world samples from our hospital treated patient samples.Kaplan-Meier(K-M)survival analysis and receiver operating characteristic(ROC)curves were employed to evaluate this gene signature’s predictive accuracy and robustness in both training and testing cohorts,respectively.Additionally,the study utilized the CIBERSORT algorithm and single-sample gene set enrichment analysis to explore the signature’s immune infiltration landscape and underlying functional implications.The support vector machine algorithm was applied to evaluate the signature’s potential in predicting chemotherapy outcomes.The findings unveiled a novel three TRP channels-related gene signature(MCOLN1,TRPM5,and TRPV4)in colon adenocarcinoma(COAD).The ROC and K-M survival curves in the training dataset(AUC=0.761;p=1.58e-05)and testing dataset(AUC=0.699;p=0.004)showed the signature’s robust predictive capability for the overall survival of COAD patients.Analysis of the immune infiltration landscape associated with the signature revealed higher immune infiltration,especially an increased presence of M2 macrophages,in high-risk group patients compared to their low-risk counterparts.High-risk score patients also exhibited potential responsiveness to immune checkpoint inhibitor therapy,evident through increased CD86 and PD-1 expression profiles.Moreover,the TRPM5 gene within the signature was highly expressed in the chemoresistance group(p=0.00095)and associated with poor prognosis(p=0.036)in COAD patients,highlighting its role as a hub gene of chemoresistance.Ultimately,this signature emerged as an independent prognosis factor for COAD patients(p=6.48e-06)and expression of model gene are validated by public data and real-world patients.Overall,this bioinformatics study provides valuable insights into the prognostic implications and potential chemotherapy resistance mechanisms associated with TRPs-related genes in colon cancer.

METTL5 promotes cell proliferation,invasion,and migration by up-regulating Toll-like receptor 8 expression in colorectal cancer

BACKGROUND N6-methyladenosine(m6A)modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors.However,despite its significance,the comprehensive investigation of METTL5,a key m6A methyltransferase,in colorectal cancer(CRC)remains limited.AIM To investigate the role of METTL5 in CRC.METHODS We assessed METTL5 expression levels in clinical samples obtained from CRC patients as well as in CRC cell lines.To elucidate the downstream targets of METTL5,we performed RNA-sequencing analysis coupled with correlation analysis,leading us to identify Toll-like receptor 8(TLR8)as a potential downstream target.In vitro functional assessments of METTL5 and TLR8 were conducted using CCK-8 assays,scratch assays,as well as assays measuring cell migration and invasion.RESULTS Our findings reveal a pronounced upregulation of METTL5 expression in both CRC cells and tissues,which correlated significantly with an unfavorable prognosis.In vitro experiments unequivocally demonstrated the oncogenic role of METTL5,as evidenced by its promotion of CRC cell proliferation,invasion,and migration.Notably,we identified TLR8 as a downstream target of METTL5,and subsequent down-regulation of TLR8 led to a significant inhibition of CRC cell proliferation,invasion,and tumor growth.CONCLUSION The heightened expression of METTL5 in CRC is strongly associated with clinicopathological features and a poor prognosis,thereby underscoring its potential utility as a critical marker for facilitating early diagnosis and prognostication in CRC.

N-acetylcysteine and zinc sulphate abate di-2-ethylhexyl phthalate-mediated reproductive dysfunction in rats:Focus on oxidative and sex hormone receptors mechanisms

Objective:To investigate the potential of N-acetylcysteine(NAC)and zinc sulphate(ZnSO_(4))in mitigating reproductive dysfunction caused by di-2-ethylhexyl phthalate(DEHP)in rats and to understand the underlying mechanisms,specifically oxidative stress and sex hormone receptor activity.Methods:Thirty-five male Wistar rats were randomly divided into five equal groups(n=7 per group).Group 1 was administered 0.5 mL of distilled water and served as the control group.Group 2 was given only DEHP(750 mg/kg/day),while group 3,4 and 5 were given DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day),DEHP(750 mg/kg/day)plus ZnSO_(4)(0.5 mg/kg/day),and DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day)as well as ZnSO_(4)(0.5 mg/kg/day),respectively.All treatments lasted for 21 days.Samples were obtained after the rats were sacrificed,and hormones levels in the serum and markers of oxidative stress in the testicles were analyzed using the enzyme-linked immunosorbent assay.The amount of androgen receptors in the testicles was determined by immunohistochemistry,and the susceptibility of testosterone and DEHP to bind to androgen receptor and 5α-reductase was determined by molecular docking studies.Results:DEHP decreased reproductive hormones,testicular antioxidant enzymes,increased malondialdehyde levels,and negatively impacted histology of the pituitary and testes.NAC or ZnSO_(4) treatment showed a marked improvement in testicular antioxidant status and hormone levels,as well as a positive effect on the histology of the pituitary and testes.The combination of both treatments appeared to be more effective.The affinity of DEHP to bind to androgen receptors may lead to disruption of androgen receptor signaling,which can further result in dysfunction of hormones related to androgen.However,NAC is more likely to form stronger binding interactions with follicle stimulating hormone and luteinizing hormone receptors,as well as gonadotropin-releasing hormone receptors,when compared to DEHP.Conclusions:The possibility that NAC and ZnSO_(4) could downregulate DEHP-induced sex hormone changes is suggested by their potential to reduce toxicity.

Argon preconditioning protects neuronal cells with a Toll-like receptor-mediated effect

The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this study,human neuroblastoma SH-SY5Y cells were treated with different concentrations of argon(25%,50%,and 74%;21%O_(2),5%CO_(2),balance nitrogen)at different time intervals before inflicting damage with rotenone(20μM,4 hours).Apoptosis was determined by flow cytometry after annexin V and propidium iodide staining.Surface expressions of Toll-like receptors 2 and 4 were also examined.Cells were also processed for analysis by western blot and qPCR to determine the expression of apoptotic and inflammatory proteins,such as extracellular-signal regulated kinase(ERK1/2),nuclear transcription factor-κB(NF-κB),protein kinase B(Akt),caspase-3,Bax,Bcl-2,interleukin-8,and heat shock proteins.Immunohistochemical staining was performed for TLR2 and 4 and interleukin-8.Cells were also pretreated with OxPAPC,an antagonist of TLR2 and 4 to elucidate the molecular mechanism.Results showed that argon preconditioning before rotenone application caused a dose-dependent but not a time-dependent reduction in the number of apoptotic cells.Preconditioning with 74%argon for 2 hours was used for further experiments showing the most promising results.Argon decreased the surface expression of TLR2 and 4,whereas OxPAPC treatment partially abolished the protective effect of argon.Argon increased phosphorylation of ERK1/2 but decreased NF-κB and Akt.Preconditioning inhibited mitochondrial apoptosis and the heat shock response.Argon also suppressed the expression of the pro-inflammatory cytokine interleukin-8.Immunohistochemistry confirmed the alteration of TLRs and interleukin-8.OxPAPC reversed the argon effect on ERK1/2,Bax,Bcl-2,caspase-3,and interleukin-8 expression,but not on NF-κB and the heat shock proteins.Taken together,argon preconditioning protects against apoptosis of neuronal cells and mediates its action via Toll-like receptors.Argon may represent a promising therapeutic alternative in various clinical settings,such as the treatment of stroke.

Inhibiting 5-hydroxytryptamine receptor 3 alleviates pathological changes of a mouse model of Alzheimer's disease

Extracellular amyloid beta(Aβ) plaques are main pathological feature of Alzheimer’s disease.However,the specific type of neuro ns that produce Aβ peptides in the initial stage of Alzheimer’s disease are unknown.In this study,we found that 5-hydroxytryptamin receptor 3A subunit(HTR3A) was highly expressed in the brain tissue of transgenic amyloid precursor protein and presenilin-1 mice(an Alzheimer’s disease model) and patients with Alzheimer’s disease.To investigate whether HTR3A-positive interneurons are associated with the production of Aβ plaques,we performed double immunostaining and found that HTR3A-positive interneurons were clustered around Aβ plaques in the mouse model.Some amyloid precursor protein-positive or β-site amyloid precursor protein cleaving enzyme-1-positive neurites near Aβ plaques were co-localized with HTR3A interneurons.These results suggest that HTR3A-positive interneurons may partially contribute to the generation of Aβ peptides.We treated 5.0-5.5-month-old model mice with tro pisetron,a HTR3 antagonist,for 8 consecutive weeks.We found that the cognitive deficit of mice was partially reversed,Aβ plaques and neuroinflammation we re remarkably reduced,the expression of HTR3 was remarkably decreased and the calcineurin/nuclear factor of activated T-cell 4 signaling pathway was inhibited in treated model mice.These findings suggest that HTR3A interneurons partly contribute to generation of Aβ peptide at the initial stage of Alzheimer’s disease and inhibiting HTR3 partly reve rses the pathological changes of Alzheimer’s disease.

Inhibition of 5-HT_3 Receptors-activated Currents by Cannabinoids in Rat Trigeminal Ganglion Neurons

This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.

Null Single Nucleotide Polymorphism in Chemokine Receptor 5 (CCR5) Genes among the Ijaw Ethnic Population of Nigeria

Background: A deletion of 32 bp in the nucleotide sequence of CCR5 gene results in a defective CCR5 which confers protection from HIV infection in the homozygous state, while reducing the rate of disease progression to AIDS and death in the heterozygous state. The status of the CCR5Δ32 gene has not been reported in Nigeria. Aim: This study was aimed at analyzing single nucleotide polymorphism of CCR5 gene among the Ijaws resident in Yenagoa, Nigeria. Methods: 100 subjects (75 HIV negative and 25 HIV positive control) were recruited for this study. The CCR5 genes were amplified by 2 Stage PCR reaction using GeneAmp 9700 PCR system utilizing specific primers that would flank 32 bp deletion, followed by agarose gel electrophoresis, DNA sequencing of 20 subjects was done followed by phylogenetic and polymorphism analysis. Results: The results showed that 75 (100%) of the HIV negative subjects had 189 base pair in their CCR5 gene. Nucleotide of the 20 (100%) of the sequenced samples were conservatively same and no SNP was observed. Conclusion: This study documented no SNPs in CCR5 gene of the study population hence;the study population has no protection from HIV infection.

Relationship between expression of chemokine receptors CCR3, CCR5 and CXCR3 on CD4^＋ T cells and spontaneous abortion in mice

Background Previous studies have shown that local immune cells in the feto-maternal interface are recruited from peripheral blood, and that chemokines and their receptors play an initial and key role in this recruitment process. In this study, we aimed to determine whether spontaneous abortion is associated with the expression of chemokine receptors CCR3, CCR5, and CXCR3 on CD4^＋ T cells. Methods Peripheral blood, spleen, and thymus were collected from the spontaneous abortion mouse model CBA/JxDBA/2 （SA group, n=14）, the normal pregnant mouse model CBA/JxBALB/c （NP group, n=13）, and normal non-pregnant CBA/J mice （NNP group, n=11）. The number of chemokine receptors CCR3, CCR5, and CXCR3 expressed on CD4^＋ T cells was measured by double-label flow cytometry （FCM） method. Results In peripheral blood, the SA group had significantly lower CCR3 expression （P 〈0.01） and higher CCR5 and CXCR3 expression （P 〈0.01） on CD4^＋ T cells than did the NP group. But comparing these chemokines between the SA and NNP groups, there was no significant difference （P 〉0.05）. In spleen, the SA group expressed significantly lower CCR3 expression （P 〈0.01） and higher CCR5 and CXCR3 expression （P 〈0.05） on CD4^＋ T cells than did the NP group. When compared with the NNP group, the SA group had significantly higher CCR3 expression （P 〈0.01）, but was not statistically different with regards to the other two chemokines （P 〉0.05）. In thymus, the SA group had significantly lower CCR3 expression （P 〈0.05） and higher CXCR3 expression （P 〈0.05） on CD4^＋ T cells than the NP group, with no significant difference in CCR5 expression （P 〉0.05）. Compared with the NNP group, the SA group had higher CCR3 expression （P 〈0.01）, but there was no statistical difference in CXCR3 and CCR5 expression （P 〉0.05） between the two groups. Conclusion The abnormal expression of CCR3, CCR5 and CXCR3 on CD4^＋ T cells may play an important role in the pathogenesis of spontaneous abortion.

Bile acid receptors and nonalcoholic fatty liver disease

With the high prevalence of obesity, diabetes, and otherfeatures of the metabolic syndrome in United States, nonalcoholic fatty liver disease(NAFLD) has inevitably become a very prevalent chronic liver disease and is now emerging as one of the leading indications for liver transplantation. Insulin resistance and derangement of lipid metabolism, accompanied by activation of the pro-inflammatory response and fibrogenesis, are essential pathways in the development of the more clinically significant form of NAFLD, known as nonalcoholic steatohepatitis(NASH). Recent advances in the functional characterization of bile acid receptors, such as farnesoid X receptor(FXR) and transmembrane G protein-coupled receptor(TGR) 5, have provided further insight in the pathophysiology of NASH and have led to the development of potential therapeutic targets for NAFLD and NASH. Beyond maintaining bile acid metabolism, FXR and TGR5 also regulate lipid metabolism, maintain glucose homeostasis, increase energy expenditure, and ameliorate hepatic inflammation. These intriguing features have been exploited to develop bile acid analogues to target pathways in NAFLD and NASH pathogenesis. This review provides a brief overview of the pathogenesis of NAFLD and NASH, and then delves into the biological functions of bile acid receptors, particularly with respect to NASH pathogenesis, with a description of the associated experimental data, and, finally, we discuss the prospects of bile acid analogues in the treatment of NAFLD and NASH.

Electroacupuncture improves neuropathic pain Adenosine, adenosine 5'-triphosphate disodium and their receptors perhaps change simultaneously

Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.

Targeting androgen receptor and trail： a novel treatment paradigm for breast cancer

OBJECTIVE TNF-related apoptosis-inducing ligand(TRAIL)is a promising cancer therapeutic agent due to its minimal toxicity to normal tissues and remarkable apoptotic activity in tumors.However,most breast cancer cells are resistant to TRAIL-induced apoptosis.Our objectives are to investigate the underlying molecular mechanisms and to develop strategies to overcome such resistance.METHODS To identify modulators of TRAIL-induced apoptosis,we carried out a genome wide si RNA screen.To validate the screening result,we either silenced or overexpressed the identified genes in various breast cancer cells and changes in growth and TRAIL-induced cell apoptosis were determined in vitro and in an orthotopic xenograft mouse model.Finally,we investigated whether small molecules targeting the identified genes improve the effectiveness of TRAIL-therapy.RESULTS We unexpectedly identified androgen receptor(AR)to be responsible for TRAIL resistance.While AR is classically viewed as the key factor in prostate cancer progression,we found that AR expression levels were markedly elevated in human invasive breast cancer specimens including triple-negative breast cancers(TNBC)that are highly aggressive with poor prognosis.Importantly,breast cancer cell lines express different levels of AR that correlated with their TRAIL resistance.AR overexpression in MDA-MB-231 and MDA-MB-436 cells suppressed the TRAIL sensitivity whereas knockdown of AR rendered MCF-7 and MDA-MB-453 cells sensitive to TRAIL-induced apoptosis.AR overexpression also induced TRAIL resistance in breast tumors in vivo.Further,we observed an upregulation of the TRAIL receptor,death receptor 5(DR5)in breast cancer cells,following the removal or inhibition of AR by its antagonists Casodex and MDV3100.Treatment with AR antagonists also enhanced TRAIL-induced breast cancer cell apoptosis.CONCLUSION AR signaling suppresses TRAIL-induced breast cancer cell apoptosis,in part,by suppressing DR5 expression,and a combination of AR antagonists together with TRAIL may be a novel and effective therapy for TNBC.

Correlation between expression of two transforming growth factor-beta 1 receptors and microvascular density in a rat model of cerebral ischemia and reperfusion injury

The effects of transforming growth factor-β1 （TGF-β1） are currently controversial. Whether TGF-β1 promotes or inhibits revascularization under different conditions remains poorly understood. Based on previous studies, the current experiment established rat models of cerebral ischemia and reperfusion injury （IRI）, and demonstrated that pathological and functional damage was also increased after IRI. The most serious damage was observed at 3 days after reperfusion, at which time microvascular density fell to its lowest level. Soon afterwards, microvascular density increased, new collateral circulation was gradually established at 4 to 7 days after reperfusion, and pathological damage and neurological deficits were improved. TGF-β1, activin receptor-like kinase 5 （ALK5） mRNA and protein expression levels increased gradually over time. In contrast, ALK1 mRNA and protein expression decreased over the same period. A significant negative correlation was detected between microvascular density and expression of the ALK5 gene transcript. There was no correlation between microvascular density and ALK1 gene transcriptional expression following cerebral IRI in a rat model. These findings suggest that ALK5, rather than ALK1, is the critical receptor in the TGF-β1 signal pathways after cerebral IRI.

Augmentative effect of tetrandrine on pentobarbital hypnosis mediated by 5-HT_(1A) and 5-HT_(2A/2C) receptors in mice

It has been reported that augmentative effect of tetrandrine on pentobarbital hypnosis in mice may be related to serotonergic system. The present study was undertaken to investigate the interaction of tetrandrine and different 5-HT receptors on pentobarbital-induced sleep by using the loss-of-righting reflex method. The results showed that augmentative effect of tetrandrine on pentobarbital hypnosis in mice were potentiated by the p-MPPI （5-HT1A receptor antagonist） （1 mg/kg, i.p.） and ketanserin （5-HT2A/2C receptor antagonist） （1.5 mg/kg, i.p.）, respectively. Pretreatment with either 8-OH-DPAT （5-HT1A receptor agonist） （0.1 mg/kg, s.c.） or DOI （5-HT2A/2C receptor agonist） （0.2 mg/kg, i.p.） significantly decreased pentobarbital-induced sleep time, and tetrandrine （60 mg/kg, i.g.） significantly reversed this effect. These results suggest that both the 5-HTLA and 5-HT2A/2C subfamily may be involved in the potentiating mechanism of tetrandrine＇s effects on pantobarbital hypnosis.

GRK5 is an essential co-repressor of the cardiac mineralocorticoid receptor and is selectively induced by finerenone

BACKGROUND In the heart,aldosterone(Aldo)binds the mineralocorticoid receptor(MR)to exert damaging,adverse remodeling-promoting effects.We recently showed that G protein-coupled receptor-kinase(GRK)-5 blocks the cardiac MR by directly phosphorylating it,thereby repressing its transcriptional activity.MR antagonist(MRA)drugs block the cardiac MR reducing morbidity and mortality of advanced human heart failure.Non-steroidal MRAs,such as finerenone,may provide better cardio-protection against Aldo than classic,steroidal MRAs,like spironolactone and eplerenone.AIM To investigate potential differences between finerenone and eplerenone at engaging GRK5-dependent cardiac MR phosphorylation and subsequent blockade.METHODS We used H9c2 cardiomyocytes,which endogenously express the MR and GRK5.RESULTS GRK5 phosphorylates the MR in H9c2 cardiomyocytes in response to finerenone but not to eplerenone.Unlike eplerenone,finerenone alone potently and efficiently suppresses cardiac MR transcriptional activity,thus displaying inverse agonism.GRK5 is necessary for finerenone’s inverse agonism,since GRK5 genetic deletion renders finerenone incapable of blocking cardiac MR transcriptional activity.Eplerenone alone does not fully suppress cardiac MR basal activity regardless of GRK5 expression levels.Finally,GRK5 is necessary for the antiapoptotic,anti-oxidative,and anti-fibrotic effects of both finerenone and eplerenone against Aldo,as well as for the higher efficacy and potency of finerenone at blocking Aldo-induced apoptosis,oxidative stress,and fibrosis.CONCLUSION Finerenone,but not eplerenone,induces GRK5-dependent cardiac MR inhibition,which underlies,at least in part,its higher potency and efficacy,compared to eplerenone,as an MRA in the heart.GRK5 acts as a co-repressor of the cardiac MR and is essential for efficient MR antagonism in the myocardium.

Effects of 5-HT2B, 5-HT3 and 5-HT4 receptor antagonists on gastrointestinal motor activity in dogs

AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious dogs.METHODS:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs before and after 5-HT2B,5-HT3 and 5-HT4 receptor antagonist administration.The force transducers were implanted on the serosal surfaces of the gastric antrum,terminal ileum,ileocecal sphincter and colon.Test materials or vehicle alone was administered as an intravenous bolus injection during a quiescent period of the whole colon in the interdigestive state.The effects of these receptor antagonists on normal gastrointestinal motor activity were analyzed.RESULTS:5-HT2B,5-HT3 and 5-HT4 receptor antagonists had no contractile effect on the fasting canine terminal ileum.The 5-HT3 and 5-HT4 receptor antagonists inhibited phaseⅢof the interdigestive motor complex of the antrum and significantly inhibited colonic motor activity.In the proximal colon,the inhibitory effect was dose dependent.Dose dependency,however,was not observed in the distal colon.The 5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.CONCLUSION:The 5-HT3 and 5-HT4 receptor antagonists inhibited normal colonic motor activity.The5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.

Casticin-induced apoptosis involves death receptor 5 upregulation in hepatocellular carcinoma cells

AIM:To investigate the apoptotic activities of casticin in hepatocellular carcinoma(HCC) cells and its molecular mechanisms.METHODS:PLC/PRF/5 and Hep G2 cell lines were cultured in vitro and the inhibitory effect of casticin on the growth of cells was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolim bromide(MTT) assay.The apoptotic cell death was examined using the cell apoptosis enzyme linked immunosorbent assay(ELISA) detection kit,flow cytometry(FCM) after propidium iodide(PI) staining and DNA agarose gel electrophoresis.The caspase activities were measured using ELISA.Reactive oxygen species(ROS) production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCFH-DA) probe labeling.Intracellular glutathione(GSH) content was measured using a glutathione assay kit.The expression of death receptor(DR)4 and DR5 proteins was analyzed by Western blotting and FCM.RESULTS:Casticin significantly inhibited the growth of human HCC(PLC/PRF/5 and Hep G2) cells in a dosedependent manner(P < 0.05).Casticin increased the percentage of the sub-G1 population in HCC cells in a concentration-dependent manner.The potency of casticin to PLC/PRF/5 cells was higher than that of 5-flurouracil(26.8% ± 4.8% vs 17.4% ± 5.1%) at 10 μmol/L for 24 h.Casticin increased the levels of Histone/DNA fragmentation and the levels of active caspase-3,-8 and-9 in a concentration-dependent manner(P < 0.05).Treatment with 30 μmol/L casticin for 24 h resulted in the formation of a DNA ladder.Casticin reduced the GSH content(P < 0.05),but did not affect the level of intracellular ROS in PLC/PRF/5 and Hep G2 cells.The thiol antioxidants,acetylcysteine(NAC) and GSH restored GSH content and attenuated casticin-induced apoptosis.In contrast,the nonthiol antioxidants,butylated hydroxyanisole and mannitol failed to do so.In the HCC cells treated with casticin for 24 h,DR5 protein level was increased.The expression of DR5 protein induced by casticin was inhibited by NAC.Pretreatment with DR5/Fc chimera protein,a blocking antibody,effectively attenuated the induction of apoptosis by casticin.CONCLUSION:Casticin-induced apoptosis of HCC cells is involved in GSH depletion and DR5 upregulation.

Neuroprotective effects of autophagy inhibition on hippocampal glutamate receptor subunits after hypoxia-ischemia-induced brain damage in newborn rats

Autophagy has been suggested to participate in the pathology of hypoxic-ischemic brain damage（HIBD）.However,its regulatory role in HIBD remains unclear and was thus examined here using a rat model.To induce HIBD,the left common carotid artery was ligated in neonatal rats,and the rats were subjected to hypoxia for 2 hours.Some of these rats were intraperitoneally pretreated with the autophagy inhibitor 3-methyladenine（10 m M in 10 μL） or the autophagy stimulator rapamycin（1 g/kg） 1 hour before artery ligation.Our findings demonstrated that hypoxia-ischemia-induced hippocampal injury in neonatal rats was accompanied by increased expression levels of the autophagy-related proteins light chain 3 and Beclin-1 as well as of the AMPA receptor subunit GluR 1,but by reduced expression of GluR 2.Pretreatment with the autophagy inhibitor 3-methyladenine blocked hypoxia-ischemia-induced hippocampal injury,whereas pretreatment with the autophagy stimulator rapamycin significantly augmented hippocampal injury.Additionally,3-methyladenine pretreatment blocked the hypoxia-ischemia-induced upregulation of Glu R1 and downregulation of GluR2 in the hippocampus.By contrast,rapamycin further elevated hippocampal Glu R1 levels and exacerbated decreased GluR2 expression levels in neonates with HIBD.Our results indicate that autophagy inhibition favors the prevention of HIBD in neonatal rats,at least in part,through normalizing Glu R1 and GluR2 expression.

chemokine/chemokine receptor pair CC L20/CC R6 in humancolorectal malignancy:An overview

Chemokines belong to a superfamily of small, cytokinelike proteins, which induce multiple physiological functions, particularly cytoskeletal rearrangement and compartment-specific migration through their interaction with G-protein-coupled receptors. Chemokines and their receptors have been widely acknowledged as essential and selective mediators in leukocyte migration in inflammatory response. It is now established that the chemokine/chemokine receptor system is also used by cancer cells to direct lymphatic and haematogenous spreading and additionally has an impact on the site of metastatic growth of different tumours. In recent years an increasing number of studies have drawn attention to CC-chemokine cysteine motif chemokine ligand 20(CCL20) and its physiological sole receptor CCR6 to play a role in the onset, development and metastatic spread of various gastrointestinal cancer entities. Among various cancer types CCR6 was also demonstrated to be significantly overexpressed in colorectal cancer(CRC) and stimulation by its physiological ligand CCL20 has been reported to promote CRC cell proliferation and migration in vitro. Further, the CCL20/CCR6 system apparently plays a role in the organ-selective liver metastasis of CRC. Here we review the literature on expression patterns of CCL20 and CCR6 and their physiological interactions as well as the currently presumed role of CCL20 and CCR6 in the formation of CRC and the development of liver metastasis, providing a potential basis for novel treatment strategies.