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

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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.

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.

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.

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.

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.

TypeⅠinositol 1, 4, 5-triphosphate receptors increase in kidney of mice with fulminant hepatic failure

AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant hepatic failure （FHF）. METHODS： FHF was induced by lipopolysaccharide （LPS） in D-galactosamine （GAIN） sensitized BALB/c mice. There were 20 mice in normal saline （NS）-treated group, 20 mice in LPS-treated group, 20 mice in GaIN- treated group, and 60 mice in GalN/LPS-treated group （FHF group）. Liver and kidney tissues were obtained at 2, 6, and 9 h after administration. The liver and kidney specimens were stained with hematoxylin-eosin for studying morphological changes under light microscope. The expression of IP3R I in kidney tissue was tested by immunohistochemistry, Western blot and reverse transcription （RT）-PCR. RESULTS： Kidney tissues were morphologically normal at all time points in all groups. IP3R I proteins were found localized in the plasma region of glomerular mesangial cells （GMC） and vascular smooth muscle cells （VSMC） in kidney by immunohistochemical staining. In kidney of mice with FHF at 6 h and 9 h IP3R I staining was upregulated. Results from Western blot demonstrated consistent and significant increment of IP3R I expression in mice with FHF at 6 h and 9 h （t = 3.16, P 〈 0.05; t = 5.43, P 〈 0.01）. Furthermore, we evaluated IP3R I mRNA expression by RT-PCR and observed marked upregulation of IP3R I mRNA in FHF samples at 2 h, 6 h and 9 h compared to controls （t = 2.97, P 〈 0.05; t = 4.42, P 〈 0.01; t = 3.81, P 〈 0.01）. CONCLUSION： The expression of IP3R I protein increased in GMC and renal VSMC of mice with FHF, possibly caused by up-regulation of IP3R I mRNA.

Inhibition of α5 GABAA receptors has preventive but not therapeutic effects on isoflurane-induced memory impairment in aged rats

The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents in hippocampal neurons. These tonic currents can be enhanced by low-dose isoflurane, which is associated with learning and memory impairment. Inverse agonists of α5 GABAARs, such as L-655,708, are able to reverse the short-term memory deficit caused by low-dose isoflurane in young animals. However, whether these negative allosteric modulators have the same effects on aged rats remains unclear. In the present study, we mainly investigated the effects of L-655,708 on low-dose(1.3%) isoflurane-induced learning and memory impairment in elderly rats. Young(3-month-old) and aged(24-month-old) Wistar rats were randomly assigned to receive L-655,708 0.5 hour before or 23.5 hours after 1.3% isoflurane anesthesia.The Morris Water Maze tests demonstrated that L-655,708 injected before or after anesthesia could reverse the memory deficit in young rats. But in aged rats, application of L-655,708 only before anesthesia showed similar effects. Reverse transcription-polymerase chain reaction showed that low-dose isoflurane decreased the mRNA expression of α5 GABAARs in aging hippocampal neurons but increased that in young animals. These findings indicate that L-655,708 prevented but could not reverse 1.3% isoflurane-induced spatial learning and memory impairment in aged Wistar rats. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Academy of Military Medical Science of China(approval No. NBCDSER-IACUC-2015128) in December 2015.

UFLC‑PDA‑MS/MS Profling of Seven Uncaria Species Integrated with Melatonin/5‑Hydroxytryptamine Receptors Agonistic Assay

Uncariae Ramulus Cum Uncis(Gou-Teng),the dried hook-bearing stems of several Uncaria plants(Rubiaceae),is a wellknown herbal medicine in China.The clinical application of Gou-Teng is bewildered for the morphological and chemical similarity between diferent species.In order to discern their chemical and biological diference,an ultra-fast liquid chromatography equipped with ion trap time-of-fight mass spectrometry(UFLC-IT/TOF-MS)combining with melatonin(MT1 and MT2)and 5-hydroxytryptamine(5-HT1A and 5-HT2C)receptors agonistic assay in vitro was conducted on seven Uncaria species.As a result,57 compounds including 35 indole alkaloids,ten favonoids,fve triterpenoids,fve chlorogenic analogues,and two other compounds were characterized based on their MS/MS patterns and UV absorptions.Specifcally,cadambine-type and corynanthein-type alkaloids were exclusively present in U.rhynchophylla and U.scandens,whereas corynoxine-type alkaloids were commonly detected in all the seven Uncaria plants.Three Uncaria species,U.rhynchophylla,U.macrophylla,and U.yunnanensis showed obviously agnostic activity on four neurotransmitter receptors(MT1,MT2,5-HT1A,and 5-HT_(2C)).This frst-time UFLCMS-IT-TOF analyses integrated with biological assay on seven Uncaria plants will provide scientifc viewpoints for the clinical application of Gou-Teng.

Down-regulation of Cardiac Bradykinin B2 Receptors and eNOs mRNA in Rats with Remnant Kidneys

The changes in the expression of cardiac bradykinin B2 receptors (BKB2Rs) and endogenous nitrix oxide synthase (eNOs) mRNA were studied in rats with remnant kidneys. Thirty-two rats were divided into sham-operated and experimental groups randomly (n=16 in each group). The remnant kidney model was established by 2-stage 5/6 nephrectomy. Blood pressure and serum Cr were measured before operation and 15, 30, 60, 120 days after 5/6 nephrectomy. Eight animals in each group were killed at the first month and 4th month after the operation. The expression of BKB2Rs and eNOs mRNAs was detected by using RT-real time PCR from isolated left ventricle, and their correlation was also analyzed. The results showed that blood pressure and serum Cr were increased significantly 15 days after 5/6 nephrectomy (both P<0.01), and the hypertension and azomia existed constantly till 120 days but had no significant fluctuation. Cardiac BKB2Rs and eNOs mRNA was declined time-dependently (both P<0.05). And there was a close positive correlation between cardiac BKB2Rs and eNOs mRNA (r=0.82, P<0.01). It was suggested that a significant chronic renal failure can be produced at least 15 days after 5/6 nephrotomy and can sustain more than 4 months. The expression of BKB2Rs and eNOs was down-regulated time-dependently in this model, and there was a significant correlation between them.

Effects of Activation and Blockade of Serotonin 5-HT1A Receptors on the Immune Response in Rats Selected for Different Levels of Aggressiveness

The present study examines the effects of serotonin (5-HT) 1A receptor ligands on humoral im-mune response in two rat lines selected for over 75 generations for the enhancement or elimination of aggression. Activation of presynaptic 5-HT1A receptors with a low dose of the selective 5-HT1A receptor agonist 8-OH-DPAT (0.1 mg/kg) or the blockade of postsynaptic 5-HT1A receptors with the antagonist WAY-100635 (1.0 mg/kg) did not affect the numbers of IgM-antibody forming cells (IgM-AFC) in the spleen of highly aggressive rats, which were characterized by higher immune responsiveness compared to nonaggressive line. On the other hand, the same doses of 8-OH-DPAT and WAY-100635, as well as a higher dose of 8-OH-DPAT (1.0 mg/kg), which is known to activate postsynaptic 5-HT1A receptors, produce immunostimulation in nonaggressive rats. However, only the highest dose of 8-OH-DPAT (5.0 mg/kg) was able to cause immunosuppression in nonaggressive rats that was mainly dependent on stimulation of postsynaptic 5-HT1A receptors. In contrast to nonaggressive rats, the dose of 1.0 mg/kg 8-OH-DPAT was sufficient to produce a decrease in the numbers of IgM-AFC in highly aggressive rats. Thus, pharmacological activation of pre- and postsynaptic 5-HT1A receptors, as well as the blockade of postsynaptic 5-HT1A receptors, produced different effects on the immune response in two lines of rats selected for high level of aggression or its absence. These data may have implications for more efficient treatments of a number of mental disorders associated with abnormal aggression.

Role of 5-HT2A Receptors in Immunomodulation in Animal Models of Aggressive Behavior

Serotonin 5-HT2A receptors are playing an important role in the pathophysiology of aggressive behaviors and in the control of immune function. In the present study, we analyzed the effects of activation and blockade of 5-HT2A receptors with selective ligands on the immune response formation in animals with aggressive behaviors induced by genetic factors (rats selected for the increased aggressiveness toward human) or by chronic social stress (mice of the CBA/Lac strain engaged in 10 days of social confrontations). Activation of 5-HT2A receptors with DOI at 1.0 mg/kg reduced the immune response level both in aggressive rats and mice compared to the corresponding vehicle-treated groups, while DOI administration did not alter the immune reaction in nonaggressive animals. The blockade of 5-HT2A receptors with ketanserin at 1.0 mg/kg resulted in immunostimulation both in mice of the CBA strain not subjected to social stress (the controls) and in nonaggressive rats selected for elimination of aggressiveness. On the other hand, its administration to CBA mice demonstrating offensive aggression enhanced the immune reaction, while the same dose of ketanserin did not modify the immune response level in rats with genetic predisposition to the increased defensive aggression. Thus, our data suggest that the role of 5-HT2A receptors in immunomodulation depends on the specific type of aggression that may be taking into account in the treatment of some neuropsychiatric disorders with the antipsychotic drugs and antidepressants targeting 5-HT2A receptors.

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.

Anti-Anxiety Effects of Prelimbic 5-HT4 Receptors in the Rat Model of Parkinson’s Disease: Evidence from Behavioral and Electrophysiological Study

Objective:Clinical and laboratory studies have demonstrated that prelimbic(PrL)and serotonin-4(5-HT4)receptors may have the key role in regulating anxiety.However,the pathophysiology of anxiety in Parkinson’s disease(PD)remains obscure.In this research,the effects of PrL 5-HT4 receptors on anti-anxiety behaviors in hemiparkinsonian rats were investigated.Methods:PD model rats were used as the research subjects,starting with behavioral changes,from the point of view of electrophysiology,the regulatory effect of PrL 5-HT4 receptors on PD-related anxiety and the possible mechanism were explored.Results:Anxiety-like behaviors were induced via MFB lesion in rats.Intra-PrL injection of 5-HT4 receptors agonist RS67333 induced anti-anxiety effects in both sham and PD group.In the sham group,PrL administration of 5-HT4 receptors antagonist SB204070 produce anti-anxiety effects,but in the PD group,the expression of anxiety-like behavior was increased.Compared to the sham group,the effective dose of the behavioral effects of the two drugs in the PD group was obviously higher.Electrophysiological data suggested that PrL administration of RS67333(SB204070)increased(decreased)the firing activities ofγ-aminobutyric acid(GABA)neurons in both groups.Compared with rats in sham group,lesioned rats had a shorter duration of the excitation(inhibition)effects on firing activities of GABA neurons.Conclusion:PrL 5-HT4 receptors regulate anxiety behaviors in PD rats,and its mechanism may be related to the down-regulation of expression or function of PrL 5-HT4 receptors in PD.

Distribution of serotonin 5-HT_(2A) and 5-HT_7 receptors in the Onuf’s nucleus of the rat spinal cord

BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytryptamine, 5-HT） regulates motoneuron activity from the Onuf’s nucleus of the spinal cord. However, few studies exist that describe 5-HT receptor distribution in the Onuf’s nucleus. In addition, the nature of the effects of 5-HT receptor on the innervating striated muscle of the pelvic floor is controversial. OBJECTIVE： To investigate the distribution of serotonin 5-HT2A and 5-HT7 receptors in motoneurons of Onuf’s nucleus in the spinal cord of male rats, and to analyze the relationship of 5-HT2A and 5-HT7 receptor to central modulation of urogenital function. DESIGN, TIME AND SETTING： The neural morphology experiment was performed at the Ultramicro-structure Laboratory of Reproductive Medicine, Basic Medical College, Chongqing Medical University, China from April to December 2007. MATERIALS： Ten adult, Sprague Dawley rats （eight males and two females） were randomly divided into gender control group （n = 4, 50% male and 50% female） and a retrograde tracing group （n = 6, 100% male） Recombinant pseudorabies virus （PRV-152） was provided by Professor LW Enquist from Princeton University, USA. Rabbit anti-5-HT2A and 5-HT7 receptor antibodies were purchased from Diasorin, France. METHODS： In the gender control group, the spinal L5-6 segments were harvested, sliced, and then incubate antibodies specific against 5-HT2A or 5-HT7 receptors for immunohistochemical staining. In the retrograde tracing group, PRV-152 was separately injected into the right ischiocavernosus （ischiocavernosus subgroup, n = 3） and the right external urethral sphincter （external urethral sphincter subgroup, n = 3）. Four days after injection, L5-6 segments were harvested, sliced, and incubated with antibodies specific against 5-HT2A or 5-HT7 receptors for double-labeling immunofluorescence staining. MAIN OUTCOME MEASURES： Distribution analysis of 5-HT2A and 5-HT7 receptors in Onuf’s nucleus utilizing optical or laser confocal microscopy. RESULTS： 5-HT2A receptor immunoreactivity was revealed primarily in the medial region of the dorsolateral nucleus of Onuf’s nucleus. 5-HT7 receptor expression was observed in the lateral part of the dorso-lateral nucleus. 5-HT2A and 5-HT7 receptor expressions in the Onuf’s nucleus were significantly greater in male rats, compared to female rats. Double-labeling immunofluorescence demonstrated that 5-HT2A recepto were distributed primarily in the surrounding motoneurons innervating the ischiocavernosus, and 5-HT7 receptors were primarily expressed in motoneurons innervating the external urethral sphincter. CONCLUSION： Motoneurons innervating the ischiocavernosus and external urethral sphincter are located primarily in the medial and lateral region of the dorsolateral nucleus of L5-6 segments. The 5-HT2A receptor-innervating ischiocavernosus may be preferentially involved in the regulation of sexual reflex, and the 5-HT7 receptor-innervating external urethral sphincter may mainly join in regulating micturition reflex.

Localization and role of metabotropic glutamate receptors subtype 5 in the gastrointestinal tract

Metabotropic glutamate receptor subtype 5 (mGluR5) is a Group I mGlu subfamily of receptors coupled to the inositol trisphosphate/diacylglycerol pathway. Like other mGluR subtypes, mGluR5s contain a phylogenetically conserved, extracellular orthosteric binding site and a more variable allosteric binding site, located on the heptahelical transmembrane domain. The mGluR5 receptor has proved to be a key pharmacological target in conditions affecting the central nervous system (CNS) but its presence outside the CNS underscores its potential role in pathologies affecting peripheral organs such as the gastrointestinal (GI) tract and accessory digestive organs such as the tongue, liver and pancreas. Following identification of mGluR5s in the mouth, various studies have subsequently demonstrated its involvement in mechanical allodynia, inflammation, pain and oral cancer. mGluR5 expression has also been identified in gastroesophageal vagal pathways. Indeed, experimental and human studies have demonstrated that mGluR5 blockade reduces transient lower sphincter relaxation and reflux episodes. In the intestine, mGluR5s have been shown to be involved in the control of intestinal inflammation, visceral pain and the epithelial barrier function. In the liver, mGluR5s have a permissive role in the onset of ischemic injury in rat and mice hepatocytes. Conversely, livers from mice treated with selective negative allosteric modulators and mGluR5 knockout mice are protected against ischemic injury. Similar results have been observed in experimental models of free-radical injury and in vivo mouse models of acetaminophen intoxication. Finally, mGluR5s in the pancreas are associated with insulin secretion control. The picture is, however, far from complete as the review attempts to establish in particular as regards identifying specific targets and innovative therapeutic approaches for the treatment of GI disorders.

Differential roles of RIG-Ⅰ like receptors in SARS-CoV-2 infection

Retinoic acid-inducible gene Ⅰ (RIG-Ⅰ) and melanoma differentiation-associated protein 5 (MDA5) sense viral RNA and activate antiviral immune responses.Herein we investigate their functions in human epithelial cells,the primary and initial target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).A deficiency in MDA5,RIG-Ⅰ or mitochondrial antiviral signaling protein (MAVS) enhanced viral replication.The expression of the type I/III interferon(IFN) during infection was impaired in MDA5;and MAVS;,but not in RIG-Ⅰ;,when compared to wild type (WT) cells.The mRNA level of full-length angiotensin-converting enzyme 2 (ACE2),the cellular entry receptor for SARS-CoV-2,was approximately 2.5-fold higher in RIG-Ⅰ;than WT cells.These data demonstrate MDA5 as the predominant SARS-CoV-2 sensor,IFN-independent induction of ACE2 and anti-SARS-CoV-2 role of RIG-Ⅰ in epithelial cells.

Human embryonic stem cell lines with ccr5-del32 allele conferring resistance to HIV

A 32bp deletion in the chemokine receptor 5 (CCR5) gene (CMKBR5) was shown to be linked to HIV resistance. Bone marrow transplantation from the homozygous CCR5-del32 donor to a CDC Stage 2 HIV-positive recipient was demonstrated to confer a HIV resistance, resulting in discontinuation of antiretroviral therapy. In search for an unlimited source of CCR5-del32 cells for transplantation purposes, we tested 137 human embryonic stem cell (hESC) lines from the Reproductive Genetics Institute’s hESC lines collection, and report here the finding of 12 hESC lines with the CCR5-del32 allele, one of which represents a unique partenogenetic ESC line containing two copies of this deletion and may be studied for utility in stem cell transplantation treatment of HIV.

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.