The N-formyl peptide receptors: contemporary roles in neuronal function and dysfunction

N-formyl peptide receptors(FPRs)were first identified upon phagocytic leukocytes,but more than four decades of research has unearthed a plethora of non-myeloid roles for this receptor family.FPRs are expressed within neuronal tissues and markedly in the central nervous system,where FPR interactions with endogenous ligands have been implicated in the pathophysiology of several neurodegenerative diseases including Alzheimer's disease and Parkinson's disease,as well as neurological cancers such as neuroblastoma.Whilst the homeostatic function of FPRs in the nervous system is currently undefined,a variety of novel physiological roles for this receptor family in the neuronal context have been posited in both human and animal settings.Rapid developments in recent years have implicated FPRs in the process of neurogenesis and neuronal differentiation which,upon greater characterisation,could represent a novel pharmacological target for neuronal regeneration therapies that may be used in the treatment of brain/spinal cord injury,stroke and neurodegeneration.This review aims to summarize the recent progress made to determine the physiological role of FPRs in a neuronal setting,and to put forward a case for FPRs as a novel pharmacological target for conditions of the nervous system,and for their potential to open the door to novel neuronal regeneration therapies.

Glucagon-like peptide 1 receptor activation:anti-inflammatory effects in the brain

The glucagon-like peptide 1 is a pleiotropic hormone that has potent insulinotropic effects and is key in treating metabolic diseases such as diabetes and obesity.Glucagon-like peptide 1 exerts its effects by activating a membrane receptor identified in many tissues,including diffe rent brain regions.Glucagon-like peptide 1 activates several signaling pathways related to neuroprotection,like the support of cell growth/survival,enhancement promotion of synapse formation,autophagy,and inhibition of the secretion of proinflammatory cytokines,microglial activation,and apoptosis during neural morphogenesis.The glial cells,including astrocytes and microglia,maintain metabolic homeostasis and defe nse against pathogens in the central nervous system.After brain insult,microglia are the first cells to respond,followed by reactive astrocytosis.These activated cells produce proinflammato ry mediators like cytokines or chemokines to react to the insult.Furthermore,under these circumstances,mic roglia can become chro nically inflammatory by losing their homeostatic molecular signature and,consequently,their functions during many diseases.Several processes promote the development of neurological disorders and influence their pathological evolution:like the formation of protein aggregates,the accumulation of abnormally modified cellular constituents,the formation and release by injured neurons or synapses of molecules that can dampen neural function,and,of critical impo rtance,the dysregulation of inflammato ry control mechanisms.The glucagonlike peptide 1 receptor agonist emerges as a critical tool in treating brain-related inflammatory pathologies,restoring brain cell homeostasis under inflammatory conditions,modulating mic roglia activity,and decreasing the inflammato ry response.This review summarizes recent advances linked to the anti-inflammato ry prope rties of glucagon-like peptide 1 receptor activation in the brain related to multiple sclerosis,Alzheimer’s disease,Parkinson’s disease,vascular dementia,or chronic migraine.

Glucagon-like peptide 1 receptor agonist:A potential game changer for cholangiocarcinoma

Glucagon-like peptide-1 receptor(GLP-1R)agonist,a subgroup of incretin-based anti-diabetic therapies,is an emerging medication with benefits in reducing blood glucose and weight and increasing cardiovascular protection.Contrarily,concerns have been raised about GLP-1R agonists increasing the risk of particular cancers.Recently,several epidemiological studies reported contradictory findings of incretin-based therapy on the risk modification for cholangiocarcinoma(CCA).The first cohort study demonstrated that incretin-based therapy was associated with an increased risk of CCA.Later studies,however,showed a null effect of incretinbased therapy on CCA risk for dipeptidyl peptidase-4 inhibitor nor GLP-1R agonist.Mechanistically,glucagon-like peptide 1 receptor is multifunctional,including promoting cell growth.High GLP-1R expressions were associated with progressive phenotypes of CCA cells in vitro.Unexpectedly,the GLP-1R agonist showed anti-tumor effects on CCA cells in vitro and in vivo with unclear mechanisms.Our recent report also showed that GLP-1R agonists suppressed the expression of GLP-1R in CCA cells in vitro and in vivo,leading to the inhibition of CCA tumor growth.This editorial reviews recent evidence,discusses the potential effects of GLP-1R agonists in CCA patients,and proposes underlying mechanisms that would benefit from further basic and clinical investigation.

Impact of glucagon-like peptide receptor agonists on endoscopy and its preoperative management: Guidelines, challenges, and future directions

Glucagon-like peptide receptor agonists(GLP-1RA)are used to treat type 2 diabetes mellitus and,more recently,have garnered attention for their effect-iveness in promoting weight loss.They have been associated with several gastrointestinal adverse effects,including nausea and vomiting.These side effects are presumed to be due to increased residual gastric contents.Given the potential risk of aspiration and based on limited data,the American Society of Anesthesi-ologists updated the guidelines concerning the preoperative management of patients on GLP-1RA in 2023.They included the duration of mandated cessation of GLP-1RA before sedation and usage of“full stomach”precautions if these medications were not appropriately held before the procedure.This has led to additional challenges,such as extended waiting time,higher costs,and increased risk for patients.In this editorial,we review the current societal guidelines,clinical practice,and future directions regarding the usage of GLP-1RA in patients undergoing an endoscopic procedure.

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

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

Molecular and evolutionary analyses of formyl peptide receptors suggest the absence of VNO-specific FPRs in primates

Formyl peptide receptors (FPRs) were observed to expand in rodents and were recently suggested as candidate vomeronasal chemo-sensory receptors. Since vomeronasal chemosensory receptors usually underwent positive selection and evolved concordantly with the vomeronasal organ (VNO) morphology, we surveyed FPRs in primates in which VNO morphology is greatly diverse and thus it would provide us a clearer view of VNO-FPRs evolution. By screening available primate genome sequences, we obtained the FPR repertoires in representative primate species. As a result, we did not find FPR family size expansion in primates. Further analyses showed no evolution-ary force variance between primates with or without VNO structure, which indicated that there was no functional divergence among pri-mates FPRs. Our results suggest that primates lack the VNO-specific FPRs and the FPR expansion is not a common phenomenon in mammals outside rodent lineage, regardless of VNO complexity.

THE EXPRESSION OF RECEPTORS FOR VASOACTIVE INTESTINAL PEPTIDE AND SECRETIN IN COLON NEOPLASMS

Objective: To investigate the expression of the receptors for vasoactive intestinal peptide (VIP) and secretin in colon cancer. Methods: This study visualized and characterized the receptors for VIP and secretin in the sequence of human tumor-free colon, adenoma, carcinoma, liver metastasis using storage phosphor autoradiography. Results: Receptors for VIP and secretin were demonstrated in tumor-free colon and colon tumors. A decrease in affinity of VIP receptors was shown in the colonic liver metastasis (Kd = 3.30 nmol) when compared with tumor-free colon (Kd = 0.82 nmol). An up-regulation of receptors for secretin was found in colonic liver metastases. Conclusions: VIP and secretin were both expressed on normal colon tissues. Binding of VIP decreased while secretin increased in colonic liver metastasis. A down-regulation of receptors for VIP in colonic liver metastases may helpful to understand the migration of colon cancer.

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

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

FPR1 Antagonist (BOC-MLF) Inhibits Amniotic Epithelial-mesenchymal Transition

Objective:Premature rupture of membranes(PROM)is a common pregnancy disorder that is closely associated with structural weakening of fetal membranes.Studies have found that formyl peptide receptor 1(FPR1)activates inflammatory pathways and amniotic epithelial-mesenchymal transition(EMT),stimulates collagen degradation,and leads to membrane weakening and membrane rupture.The purpose of this study was to investigate the anti-inflammatory and EMT inhibitory effects of FPR1 antagonist(BOC-MLF)to provide a basis for clinical prevention of PROM.Methods:The relationship between PROM,FPR1,and EMT was analyzed in human fetal membrane tissue and plasma samples using Western blotting,PCR,Masson staining,and ELISA assays.Lipopolysaccharide(LPS)was used to establish a fetal membrane inflammation model in pregnant rats,and BOC-MLF was used to treat the LPS rat model.We detected interleukin(IL)-6 in blood from the rat hearts to determine whether the inflammatory model was successful and whether the anti-inflammatory treatment was effective.We used electron microscopy to analyze the structure and collagen expression of rat fetal membrane.Results:Western blotting,PCR and Masson staining indicated that the expression of FPR1 was significantly increased,the expression of collagen was decreased,and EMT appeared in PROM.The rat model indicated that LPS caused the collapse of fetal membrane epithelial cells,increased intercellular gaps,and decreased collagen.BOC-MLF promoted an increase in fetal membrane collagen,inhibited EMT,and reduced the weakening of fetal membranes.Conclusion:The expression of FPR1 in the fetal membrane of PROM was significantly increased,and EMT of the amniotic membrane was obvious.BOC-MLF can treat inflammation and inhibit amniotic EMT.

New perspectives in the management of diabetic nephropathy

Diabetic nephropathy(DN)is the leading cause of end-stage renal disease and is also associated with increased risk for cardiovascular events.Until recently,strict glycemic control and blockade of the renin-angiotensin system(RAS)constituted the mainstay of treatment of DN.However,randomized controlled trials showed that sodium-glucose cotransporter 2 inhibitors further reduce the progression of DN.Therefore,these agents are recommended in all patients with DN regardless of DN stage and HbA1c levels.Moreover,additional blockade of the RAS with finerenone,a selective non-steroidal mineralocorticoid receptor antagonist,was also shown to prevent both the decline of renal function and cardiovascular events in this population.Finally,promising preliminary findings suggest that glucagon-like peptide 1 receptor agonists might also exert reno-and cardioprotective effects in patients with DN.Hopefully,this knowledge will improve the outcomes of this high-risk group of patients.

Semaglutide for the management of diabesity:The real-world experience

BACKGROUND Diabesity(diabetes as a consequence of obesity)has emerged as a huge healthcare challenge across the globe due to the obesity pandemic.Judicious use of antidiabetic medications including semaglutide is important for optimal management of diabesity as proven by multiple randomized controlled trials.However,more real-world data is needed to further improve the clinical practice.AIM To study the real-world benefits and side effects of using semaglutide to manage patients with diabesity.METHODS We evaluated the efficacy and safety of semaglutide use in managing patients with diabesity in a large academic hospital in the United States.Several parameters were analyzed including demographic information,the data on improvement of glycated hemoglobin(HbA1c),body weight reduction and insulin dose adjustments at 6 and 12 months,as well as at the latest follow up period.The data was obtained from the electronic patient records between January 2019 to May 2023.RESULTS 106 patients(56 males)with type 2 diabetes mellitus(T2DM),mean age 60.8±11.2 years,mean durations of T2DM 12.4±7.2 years and mean semaglutide treatment for 2.6±1.1 years were included.Semaglutide treatment was associated with significant improvement in diabesity outcomes such as mean weight reductions from baseline 110.4±24.6 kg to 99.9±24.9 kg at 12 months and 96.8±22.9 kg at latest follow up and HbA1c improvement from baseline of 82±21 mmol/mol to 67±20 at 12 months and 71±23 mmol/mol at the latest follow up.An insulin dose reduction from mean baseline of 95±74 units to 76.5±56.2 units was also observed at the latest follow up.Side effects were mild and mainly gastrointestinal like bloating and nausea improving with prolonged use of semaglutide.CONCLUSION Semaglutide treatment is associated with significant improvement in diabesity outcomes such as reduction in body weight,HbA1c and insulin doses without major adverse effects.Reviews of largescale real-world data are expected to inform better clinical practice decision making to improve the care of patients with diabesity.

C-type natriuretic-peptide-potentiated relaxation response of gastric smooth muscle in streptozotocin-induced diabetic rats

AIM: To study the sensitivity of gastric smooth muscle to C-type natriuretic peptide (CNP) in streptozotocin (STZ)-induced diabetic rats. METHODS: The spontaneous contraction of a gastric smooth muscle strip was recorded by using physiological methods in rats. The expressions of CNP and natriuretic peptide receptor-B (NPR-B) in gastric tissue were examined by using immunohistochemistry techniques in the diabetic rat. RESULTS: At 4 wk after injection of STZ and vehicle, the frequency of spontaneous contraction of gastric smooth muscle was significantly reduced in diabetic rats, and the frequency was decreased from 3.10 ± 0.14 cycle/min in controls to 2.23 ± 0.13 cycle/min (n = 8, P < 0.01). However, the amplitude of spontaneous contraction was not significant different from the normal rat. CNP significantly inhibited spontaneous contraction of gastric smooth muscle in normal and diabetic rats, but the inhibitory effect was significantly potentiated in the diabetic rats. The amplitudes of spontaneous contraction were suppressed by 75.15% ± 0.71% and 58.92% ± 1.32% while the frequencies were decreased by 53.33% ± 2.03% and 26.95% ± 2.82% in diabetic and normal rats, respectively (n = 8, P < 0.01). The expression of CNP in gastric tissue was not changed in diabetic rats, however the expression of NPR-B was significantly increased in diabetic rats, and the staining indexes of NPR-B were 30.67 ± 1.59 and 17.63 ± 1.49 in diabetic and normal rat, respectively (n = 8, P < 0.01).CONCLUSION: The results suggest that CNP induced an inhibitory effect on spontaneous contraction of gastric smooth muscle, potentiated in diabetic rat via up-regulation of the natriuretic peptides-NPR-B-particulate guanylyl cyclase-cyclic GMP signal pathway.

Progastrin-releasing peptide and gastrin-releasing peptide receptor mRNA expression in non-tumor tissues of the human gastrointestinal tract

AIM： To investigate the expression of gastrin-releasing peptide （GRP） and GRP-receptor mRNA in non-tumor tissues of the human esophagus, gastrointestinal tract, pancreas and gallbladder using molecular biology techniques. METHODS： Poly A^＋ mRNA was isolated from total RNA extracts using an automated nucleic acid extractor and, subsequently, converted into single-stranded cDNA （sscDNA）. PCR amplifications were carried out using genespecific GRP and GRP-receptor primers. The specificity of the PCR amplicons was further confirmed by Southern blot analyses using gene-specific GRP and GRP-receptor hybridization probes. RESULTS： Expression of GRP and GRP-receptor mRNA was detected at various levels in nearly all segments of the non-tumor specimens analysed, except the gallbladder. In most of the biopsy specimens, coexpression of both GRP and GRP-receptor mRNA appeared to take place. However, expression of GRP mRNA was more prominent than was GRP-receptor mRNA. CONCLUSION： GRP and GRP-receptor mRNAs are expressed throughout the gastrointestinal tract and provides information for the future mapping and determination of its physiological importance in normal and tumor cells.

Vasoactive intestinal peptide,a promising agent for myopia?

AIM： To investigate the role of vasoactive intestinal peptide（VIP） in form-deprivation myopia（FDM）.METHODS： FDM was created in three groups of eight chicks by placing a translucent diffuser on their right eyes.Intravitreal injections of saline and VIP were applied once a day into the occluded eyes of groups 2 and 3,respectively.Retinoscopy and axial length（AL） measurements were performed on the first and 8^th days of diffuser wear.The retina mR NA levels of the VIP receptors and the ZENK protein in right eyes of the three groups and left eyes of the first group on day 8 were determined using real time polymerase chain reaction（PCR）.RESULTS： The median final refraction（D） in right eyes were-13.75（-16.00,-12.00）,-11.50（-12.50,-7.50）,and-1.50（-4.75,-0.75） in groups 1,2,and 3,respectively（P〈0.001）.The median AL（mm） in right eyes were 10.65（10.00,11.10）,9.90（9.70,10.00）,and 9.20（9.15,9.25） in groups 1,2,and 3,respectively（P〈0.001）.The median delta-delta cycle threshold（CT） values for the VIP2 receptors were 1.07（0.82,1.43）,1.22（0.98,1.65）,0.29（0.22,0.45） in right eyes of groups 1,2,and 3,and 1.18（0.90,1.37） in left eyes of group 1,respectively（P=0.001）.The median delta-delta CT values for the ZENK protein were 1.07（0.63,5.03）,3.55（2.20,5.55）,undetectable in right eyes of groups 1,2,and 3 and 1.89（0.21,4.73） in left eyes of group 1,respectively（P=0.001）.CONCLUSION： VIP has potential inhibitory effects in the development of FDM.

Serum amyloid A and pairing formyl peptide receptor 2 are expressed in corneas and involved in inflammation-mediated neovascularization

AIM:To solidify the involvement of Saa-related pathway in corneal neovascularization(CorNV).The pathogenesis of inflammatory CorNV is not fully understood yet,and our previous study implicated that serum amyloid A(Saa)1(Saa1)and Saa3 were among the genes up-regulated upon CorNV induction in mice.METHODS:Microarray data obtained during our profiling project on CorNV were analyzed for the genes encoding the four SAA family members(Saa1-4),six reported SAA receptors(formyl peptide receptor 2,Tlr2,Tlr4,Cd36,Scarb1,P2rx7)and seven matrix metallopeptidases(Mmp)1a,1b,2,3,9,10,13reportedly to be expressed upon SAA pathway activation.The baseline expression or changes of interested genes were further confirmed in animals with CorNV using molecular or histological methods.CorNV was induced in Balb/c and C57BL/6 mice by placing either three interrupted 10-0 sutures or a 2 mm filter paper soaked with sodium hydroxide in the central area of the cornea.At desired time points,the corneas were harvested for histology examination or for extraction of mRNA and protein.The mRNA levels of Saa1,Saa3,Fpr2,Mmp2and Mmp3 in corneas were detected using quantitative reverse transcription-PCR,and SAA3 protein in tissues detected using immunohistochemistry or western blotting.RESULTS:Microarray data analysis revealed that Saa1,Saa3,Fpr2,Mmp2,Mmp3 messengers were readily detected in normal corneas and significantly upregulated upon CorNV induction.The changes of these five genes were confirmed with real-time PCR assay.Onthe contrary,other SAA members(Saa2,Saa4),other SAA receptors(Tlr2,Tlr4,Cd36,P2rx7,etc),or other Mmps(Mmp1a,Mmp1b,Mmp9,Mmp10,Mmp13)did not show consistent changes.Immunohistochemistry study and western blotting further confirmed the expression of SAA3 products in normal corneas as well as their upregulation in corneas with CorNV.CONCLUSION:SAA-FPR2 pathway composing genes were expressed in normal murine corneas and,upon inflammatory stimuli challenge to the corneas,their expressions were up-regulated,suggesting their roles in pathogenesis of CorNV.The potential usefulness of SAA-FPR2 targets in future management of CorNVrelated diseases deserves investigation.

The sex peptide receptor in the Asian gypsy moth,Lymantria dispar,is involved in development and stress resistance

The G protein-coupled receptor(GPCR)regulates downstream genes by binding to a heterotrimeric G protein.However,the function of sex peptide receptor(SPR)in lepidopteran species is mostly unknown.Understanding the physiological functions of SPR in insects is essential for exploring new insecticidal targets.In the present study,the functions of an SPR in Lymantria dispar(Asian gypsy moth;LdSPR)were investigated.The expression of LdSPR was the highest in the 6 th instar larval stage,and there was a large difference in expression between male and female adults.After LdSPR gene silencing,L.dispar larvae showed increased sensitivity to high temperature,starvation,and oxidative stress,indicating that LdSPR enhances stress resistance.These results enrich our knowledge of the function of the insect SPRs,which will lead to a better understanding of other insect GPCR family members and the identification of new targets for the development of environmentally friendly pesticides.

Functionally diverse ligands modulate different activation states of the formyl peptide receptor 2,a G protein-coupled receptor

OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2(FPR2)mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner.METHODS Cells expressing FPR2 were incubated with weak agonists,Aβ42 and Ac2-26,before stimulation with a strong agonist,WKYMVm.Calcium mobilization,c AMP inhibition and MAP kinase activation were measured.Intramolecular FRET were determined using FPR2 constructs with an ECFP attached to the C-terminus and a Fl As H binding motif embedded in the first or third intracellular loop(IL1 or IL3,respectively).RESULTS Aβ42 did not induce significant Ca^(2+) mobilization,but positively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction in a dose-variable manner within a narrow range of ligand concentrations.Treating FPR2-expressing cells with Ac2-26,a peptide with anti-inflammatory activity,negatively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction.Intramolecular FRET assay showed that stimulation of the receptor constructs with Aβ42 brought the C-terminal domain closer to IL1 but away from IL3.An opposite conformational change was induced by Ac2-26.The FPR2 conformation induced by Aβ42 corresponded to enhanced ERK phosphorylation and attenuated p38 MAPK phosphorylation,whereas Ac2-26 induced FPR2 conformational change corresponding to elevated p38 MAPK phosphorylation and reduced ERK phosphorylation.CONCLUSION Aβ42 and Ac2-26 induce different conformational changes in FPR2.These findings provide a structural basis for FPR2 mediation of inflammatory vs anti-inflammatory functions and identify a type of receptor modulation that differs from the classic positive and negative allosteric modulation.

Ectopic expression of neurotrophic peptide derived from saposin C increases proliferation and upregulates androgen receptor expression and transcriptional activity in human prostate cancer cells

Aim： To determine the effects of the functional domain of saposin C （neurotrophic peptide [NP]） on androgen receptor （AR） expression and transcriptional activity. Methods： We constructed DNA vectors expressing NP or a chimeric peptide of the viral TAT transduction domain and NP （TAT-NP） using gene cloning technology. The effects of ectopic expression of NP or TAT-NP on cell growth were examined by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyl-2H-tetrazolium bromide （MTT） assay. Reverse transcription-polymerase chain reaction （RT-PCR）, Western blot, transient transfection and reporter gene assays were used to determine the effects of NP on AR expression and activation. Results： NP stimulated proliferation of androgen responsive LNCaP cells in the absence of androgens. RT-PCR and Western blot analyses showed that ectopic expression of NP resulted in induction of AR gene expression, and that the NP-stimulated expression of AR could be synergistically enhanced in the presence of androgens. Furthermore, reporter gene assay results showed that NP could enhance AR transactivation by increasing androgen-inducible gene reporter activity. Conclusion： We provided evidence that ectopic expression of saposin C-originated NP could upregulate AR gene expression and activate the AR transcriptional function in an androgen-independent manner in prostate cancer cells.

Controlling N-methyl-D-aspartate receptor subunit 1 with calcitonin gene related peptide after cerebral ischemic injury

BACKGROUND: Activation of N-methyl-D-aspartate receptor (NMDAR) is a key link of exitotoxicity at the phase of cerebral ischemic injury. Because NMDAR is a main way to mediate internal flow of Ca2+ among glutamic acid receptors, over-excitation can cause neuronal apoptosis. Calcitonin gene related peptide has a strongly biological activity. On one hand, it can protect ischemic neurons through inhibiting the expression of NMDAR1 mRNA; on the other hand, it can play the protective effect through down-regulating the expression of NMDAR1 mRNA by exogenous calcitonin gene related peptide. OBJECTIVE: To observe the expression of NMDAR1 and the regulatory effect of calcitonin gene related peptide on the expression of NMDAR1 mRNA and protein in the cerebral cortex of rats with focal cerebral ischemia/reperfusion (I/R). DESIGN: Randomized controlled animal study. SETTING: China Medical University. MATERIALS: A total of 216 healthy male Wistar rats, general grade, weighing 250-280 g, were selected in this study. Twelve rats were randomly selected to regard as control group; meanwhile, other 204 rats were used to establish middle cerebral artery occlusion/reperfusion (MACO) models. The main reagents were detailed as follows: calcitonin gene related peptide (Sigma Company); calcitonin gene related peptide kit (Boster Company); antibody Ⅰ, Ⅱ and antibody β-actin Ⅰ, Ⅱ of NMDAR1 mRNA and chemiluminescence reagent (Santa Cruz Company, USA). METHODS: The experiment was carried out in the Laboratory of Neurobiology of China Medical University from August 2005 to June 2006. ① Right MCAO models of rats were established to cause focal ischemia and scored based on Zea Longa five-grade scale. If the scores were 1, 2 and 3 after wakefulness, the MACO models were established successfully and involved in the experiment. A total of 120 rats with successful modeling were randomly divided into I/R group and administration group with 60 in each group. All rats in the both groups were observed at five time points, including 6, 12, 24, 48 and 72 hours after reperfusion and after 2-hour ischemia, with 12 experimental animals at each time point. Six rats were prepared for detection of hybridization in situ, and the other 6 were used for Western blotting histochemical detection. Rats in the control group were opened their skin to separate common carotid artery and not treated with line and drugs. In addition, rats in the I/R group were treated with 1 mL saline at 2 hours after focal cerebral ischemia, and then, rats in the administration group were treated with 1 mL (1 g/L) calcitonin gene related peptide at 2 hours after focal cerebral ischemia. ② The expression of NMDAR1 mRNA was detected with hybridization in situ at various time points; moreover, the expression of NMDAR1 protein was measured with Western blotting method at various time points. The results were analyzed with Metamoph imaging analytical system. MAIN OUTCOME MEASURES: The expression of NMDAR1 mRNA and its protein in cortical neurons of rats at various time points. RESULTS: A total of 84 rats were excluded because of non-symptoms, exanimation or death; and then, 132 rats were involved in the final analysis. The expression of NMDAR1 mRNA and its protein in cortical neurons of rats in the control group was 0.205±0.001 and 0.184±0.001, respectively; after I/R, expression of NMDAR1 mRNA and its protein was up-regulated, especially, expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.245±0.003, 0.287±0.004, 0.354±0.008, 0.284±0.002 and 0.217±0.006, respectively; moreover, expression of protein at 6, 12, 24, 48 and 72 hours was 0.222±0.003, 0.261±0.028, 0.311±0.004, 0.259±0.013 and 0.210±0.008, respectively. There was significant difference between the two groups (0.205±0.001, P < 0.01). The expression was up-related in the former 24 hours, reached peak at 24 hours, down-regulated, and decreased to the level of control group at 72 hours. Except 72 hours, the expression of NMDAR1 mRNA and its protein was lower in administration group than that in I/R group at other four time points. In addition, the expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.223±0.005, 0.243±0.001, 0.292±0.002, 0.250±0.003 and 0.213±0.003, respectively; moreover, the expression of protein at 6, 12, 24, 48 and 72 hours was 0.216±0.006, 0.245±0.025, 0.276±0.003, 0.241±0.045 and 0.202±0.013, respectively. There was significant difference at various time points (P < 0.05). CONCLUSION: The expressions of NMDAR1 mRNA and its protein of peripheral cortical neurons are up-related in ischemic area after focal cerebral I/R. Meanwhile, exogenous calcitonin gene related peptide can protect cortical neurons through inhibiting expression of NMDAR1 mRNA and its protein after focal cerebral I/R.

Duodenal neuroendocrine tumor-tertiary care centre experience:A case report

BACKGROUND Neuroendocrine neoplasms(NENs)are a heterogeneous group of neoplasms arising from neuroendocrine cells,which contribute a small fraction of gastrointestinal malignancies.Duodenal neuroendocrine tumors(dNETs)represent 2%of all gastroenteropancreatic NENs.NENs are heterogeneous in terms of clinical symptoms,location,and prognosis.Non-functional NETs are mostly asymptomatic and need a high degree of clinical suspicion.Diagnosis of NETs is by endoscopic,endosonographic biopsy,and histopathological examination with immunohistochemistry staining for synaptophysin and chromogranin A.CASE SUMMARY We present case reports of 5 patients obtained over a period of 10 years in our center with dNETs.One patient had moderately differentiated NET and the remaining four had well-differentiated NET.Surveillance endoscopy was recommended in all the patients and is kept under regular follow-up after performing endoscopic therapy using endoscopic mucosal resection in 4 of them and one patient was advised to undergo a Whipple procedure.CONCLUSION Recently,the number of reported cases of NETs has increased due to advancements in diagnostic modalities and prevalence because of longer survival duration.The management differs based on the site,size,proliferation grade,and locally invasive pattern.They are slow-growing tumors with a good overall prognosis.The prognosis correlates with local lymph node status and metastasis.