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.

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.

Effects of glucagon-like peptide-1 receptor agonists on renal function

Glucagon-like peptide-1(GLP-1)receptor agonists result in greater improvements in glycemic control than placebo and promote weight loss with minimal hypoglycemia in patients with type 2 diabetes mellitus.A number of case reports show an association of GLP-1receptor agonists,mainly exenatide,with the development of acute kidney injury.The present review aims to present the available data regarding the effects of GLP-1 receptor agonists on renal function,their use in subjects with chronic renal failure and their possible association with acute kidney injury.Based on the current evidence,exenatide is eliminated by renal mechanisms and should not be given in patients with severe renal impairment or end stage renal disease.Liraglutide is not eliminated by renal or hepatic mechanisms,but it should be used with caution since there are only limited data in patients with renal or hepatic impairment.There is evidence from animal studies that GLP-1 receptor agonists exert protective role in diabetic nephropathy with mechanisms that seem to be independent of their glucose-lowering effect.Additionally,there is evidence that GLP-1 receptor agonists influence water and electrolyte balance.These effects may represent new ways to improve or even prevent diabetic nephropathy.

Effects of glucagon-like peptide-1 receptor agonists on non-alcoholic fatty liver disease and inflammation

Glucagon-like peptide1 (GLP-1) is secreted from Langerhans cells in response to oral nutrient intake. Glucagon- like peptide-1 receptor agonists (GLP-1RAs) are a new class of incretin-based anti-diabetic drugs. They function to stimulate insulin secretion while suppressing glucagon secretion. GLP-1-based therapies are now well established in the management of type 2 diabetes mellitus (T2DM), and recent literature has suggested potential applications of these drugs in the treatment of obesity and for protection against cardiovascular and neurological diseases. As we know, along with change in lifestyles, the prevalence of non-alcoholic fatty liver disease (NAFLD) in China is rising more than that of viral hepatitis and alcoholic fatty liver disease, and NAFLD has become the most common chronic liver disease in recent years. Recent studies further suggest that GLP-1RAs can reduce transaminase levels to improve NAFLD by improving blood lipid levels, cutting down the fat content to promote fat redistribution, directly decreasing fatty degeneration of the liver, reducing the degree of liver fibrosis and improving inflammation. This review shows the NAFLD-associated effects of GLP-1RAs in animal models and in patients with T2DM or obesity who are participants in clinical trials. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Transient receptor potential channel A1 involved in calcitonin gene-related peptide release in neurons

Transient receptor potential channel A1 is one of the important transducers of noxious stimuli in the primary afferents, which may contribute to generation of neurogenic inflammation and hyperalgesia. The present study was designed to investigate if activation of transient receptor potential channel A1 may induce calcitonin gene-related peptide release from the primary afferent neurons. We found that application of allyl isothiocyanate, a transient receptor potential channel A1 activator, caused calcitonin gene-related peptide release from the cultured rat dorsal root ganglion neurons. Knock- down of transient receptor potential channel A1 with an antisense oligodeoxynucleotide prevented calcitonin gene-related peptide release by allyl isothiocyanate application in cultured dorsal root ganglion neurons. Thus, we concluded that transient receptor potential channel A1 activation caused calcitonin gene-related peptide release in sensory neurons.

Glucagon-like peptide-1 receptor agonists favorably address all components of metabolic syndrome

Cardiovascular death is the leading cause of mortality for patients with type 2 diabetes mellitus. The etiologyof cardiovascular disease in diabetes may be divided into hyperglycemia per se and factors operating through components of metabolic syndrome(Met S). Hyperglycemia causes direct injury to vascular endothelium and possibly on cardiac myocytes. Met S is a cluster of risk factors like obesity, hyperglycemia, hypertension and dyslipidemia. The incidence of this syndrome is rising globally. Glucagon-like peptide-1 receptor agonists(GLP-1RA) are a group of drugs, which address all components of this syndrome favorably. Experimental evidence suggests that they have favorable actions on myocardium as well. Several compounds belonging to GLP-1RA class are in market now and a large number awaiting their entry. Although, originally this class of drugs emerged as a treatment for type 2 diabetes mellitus, more recent data generated revealed beneficial effects on multiple metabolic parameters. We have studied literature published between 2000 and 2016 to look into effects of GLP-1RA on components of Met S. Results from recently concluded clinical trials suggest that some of the molecules in this class may have favorable effects on cardiovascular outcome.

Review on the Effect of Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease（NAFLD） is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus（T2DM）, dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1（GLP-1） analogues and dipeptidyl peptidase-4（DPP-4） inhibitors were widely used to treat T2 DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor（GLP-1R） is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride（TG） content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and m RNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Development of therapeutic options on type 2 diabetes in years:Glucagon-like peptide-1 receptor agonist’s role intreatment; from the past to future

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia.Type 2 diabetes (T2DM) accounting for 90% of cases globally.The worldwide prevalence of DM is rising dramatically over the last decades,from 30 million cases in 1985 to 382 million cases in 2013.It’s estimated that 451 million people had diabetes in 2017.As the pathophysiology was understood over the years,treatment options for diabetes increased.Incretin-based therapy is one of them.Glucagon-like peptide-1 receptor agonist (GLP-1 RA) not only significantly lower glucose level with minimal risk of hypoglycemia but also,they have an important advantage in themanagement of cardiovascular risk and obesity.Thus,we will review here GLP-1 RAsrole in the treatment of diabetes.

Glucagon-like peptide 1 receptor governs Wnt signaling to promote bone formation

Our previous investigation found that exendin-4 （Ex-4） , a peptide analogue of glucagon-like peptide 1 （GLP-1） , induced bone formation probably by osteoblast activation. Nevertheless, previous investigations did not observe any expression of GLP-1 receptors in osteoblasts, indicating that the direct cell target of GLP-1 and its ana- logues might not be osteoblasts but some other types of cells yet to be identified. To elucidate the underlying mecha- nisms, we performed further investigation in the present study and found that GLP-1 receptor was only identified in bone marrow mesenchymal stem cells （BMSCs）. Furthermore, activation of GLP-1 receptor by Ex-4 promoted the differentiation of B MSCs into osteoblast, which was associated with activation of PKA, nuclear translocation of [5- catenin, activation of PI3K/AKT and inhibition of GSK3β. Ex-4 also inhibited the adipocyte differentiation of BM- SCs, as evidenced by inhibition of PPARγ, lipoprotein lipase expression and lipid production. Blockade of GLP-1 receptor, PKA, PI3K or Wnt pathway, or respective knock-down of GLP-1 receptor and β-catenin in BMSCs inhib- ited the Ex-4 mediated effects. The results indicated that the GLP-1 receptor mediated osteoblastic differentiation and bone formation through stimulation of PKA/β-catenin signaling and inhibition of PKA/PI3IC/AKT/GSK3β？ signaling pathway in BMSCs. The findings reveal a new role of GLP-1 receptor for regulating osteoblastic differentia- tion of B MSCs and may provide a molecular basis for novel anabolic therapeutics against osteoporosis.

Tumor specifically internalizing peptide ‘HN-1’: Targeting the putative receptor retinoblastoma-regulated discoidin domain receptor 1 involved in metastasis

BACKGROUND Less than 0.5%of intravenously injected drugs reach tumors,contributing to side effects.To limit damage to healthy cells,various delivery vectors have been formulated;yet,previously developed vectors suffer from poor penetration into solid tumors.This issue was resolved by the discovery of HN-1 peptide isolated via biopanning a phage-display library.HN-1 targets human head and neck squamous cell carcinoma(HNSCC)(breast,thyroid;potentially lung,cervix,uterine,colon cancer),translocates across the cell membrane,and efficiently infiltrates solid tumors.HN-1 peptide has been conjugated to various anticancer drugs and imaging agents though the identity of its receptor remained enigmatic.AIM To decipher the clues that pointed to retinoblastoma(Rb)-regulated discoidindomain receptor 1 as the putative receptor for HN-1 is described.METHODS HN-1 peptide was synthesized and purified using reverse-phase highperformance liquid chromatography and gel electrophoresis.The predicted mass was confirmed by mass spectroscopy.To image the 3-dimensional structure of HN-1 peptide,PyMOL was used.Molecular modeling was also performed with PEP-FOLD3 software via RPBS bioinformatics web portal(INSERM,France).The immunohistochemistry results of discoidin domain receptor 1(DDR1)protein were obtained from the publicly accessible database in the Human Protein Atlas portal,which contained the images of immunohistochemically labeled human cancers and the corresponding normal tissues.RESULTS The clues that led to DDR1 involved in metastasis as the putative receptor mediating HN-1 endocytosis are the following:(1)HN-1 is internalized in phosphate-buffered saline and its uptake is competitively inhibited;(2)HN-1(TSPLNIHNGQKL)exhibits similarity with a stretch of amino acids in alpha5 beta3 integrin(KLLITIHDRKEF).Aside from two identical residues(Ile-His)in the middle,the overall distribution of polar and nonpolar residues throughout the sequences is nearly identical.As HN-1 sequence lacks the Arg-Gly-Asp motif recognized by integrins,HN-1 may interact with an"integrin-like"molecule.The tertiary structure of both peptides showed similarity at the 3-dimensional level;(3)HN-1 is internalized by attached cells but not by suspended cells.As culture plates are typically coated with collagen,collagen-binding receptor(expressed by adherent but not suspended cells)may represent the receptor for HN-1;(4)DDR1 is highly expressed in head and neck cancer(or breast cancer)targeted by HN-1;(5)Upon activation by collagen,DDR1 becomes internalized and compartmentalized in endosomes consistent with the determination of’energy-dependent clathrin-mediated endocytosis’as the HN-1 entry route and the identification of HN-1 entrapped vesicles as endosomes;and(6)DDR1 is essential for the development of mammary glands consistent with the common embryonic lineage rationale used to identify breast cancer as an additional target of HN-1.In summary,collagenactivated tyrosine kinase receptor DDR1 overexpressed in HNSCC assumes a critical role in metastasis.Further studies are warranted to assess HN-1 peptide’s interaction with DDR1 and the therapeutic potential of treating metastatic cancer.Additionally,advances in delivery(conformation,endocytic mechanism,repertoire of targeted cancers of HN-1 peptide),tracking(HN-1 conjugated imaging agents),and activity(HN-1 conjugated therapeutic agents)are described.CONCLUSION The discovery of DDR1 as HN-1 peptide’s putative receptor represents a significant advance as it enables identification of metastatic cancers or clinical application of previously developed therapeutics to block metastasis.

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.

Type-2 Diabetes Mellitus and Glucagon-Like Peptide-1 Receptor toward Predicting Possible Association

Aim: This study aimed to investigate the effect of non-synonymous SNPs (nsSNPs) of the Glucagon-like peptide-1 Receptor (GLP-1R) gene in protein function and structure using different computational software. Introduction: The GLP1R gene provides the necessary instruction for the synthesis of the insulin hormones which is needed for glucose catabolism. Polymorphisms in this gene are associated with diabetes. The protein is an important drug target for the treatment of type-2 diabetes and stroke. Material and Methods: Different nsSNPs and protein-related sequences were obtained from NCBI and ExPASY database. Gene associations and interactions were predicted using GeneMANIA software. Deleterious and damaging effects of nsSNPs were analyzed using SIFT, Provean, and Polyphen-2. The association of the nsSNPs with the disease was predicted using SNPs & GO software. Protein stability was investigated using I-Mutant and MUpro software. The structural and functional impact of point mutations was predicted using Project Hope software. Project Hope analyzes the mutations according to their size, charge, hydrophobicity, and conservancy. Results: The GLP1R gene was found to have an association with 20 other different genes. Among the most important ones is the GCG (glucagon) gene which is also a trans membrane protein. Overall 7229 variants were seen, and the missense variants or nsSNPs (146) were selected for further analysis. The total number of nsSNPs obtained in this study was 146. After being subjected to SIFT software (27 Deleterious and 119 Tolerated) were predicted. Analysis with Provean showed that (20 deleterious and 7 neutral). Analysis using Polyphen-2 revealed 17 probably damaging, 2 possibly damaging and 1 benign nsSNPs. Using two additional software SNPs & GO and PHD-SNPs showed that 14 and 17 nsSNPs had a disease effect, respectively. Project Hope software predicts the effect of the 14 nsSNPs on the protein function due to differences in charge, size, hydrophobicity, and conservancy between the wild and mutant types. Conclusion: In this study, the 14 nsSNPs which were highly affected the protein function. This protein is providing the necessary instruction for the synthesis of the insulin hormones which is needed for glucose catabolism. Polymorphisms in this gene are associated with diabetes and also affect the treatment of diabetic patients due to the fact that the protein acts as an important drug target.

Endogenous Endothelin-1 Regulates Hypoxia-Induced Atrial Natriuretic Peptide Secretion by Activating the MAPK/ERK and PI3K/Akt Signaling Pathways in Isolated Beating Rabbit Atria

The present study investigated a possible mechanism for endogenous endothelin-1 (ET-1) regulation of atrial natriuretic peptide (ANP) secretion in isolated perfused acute hypoxic rabbit atria. Acute hypoxia significantly enhanced the release of ET-1 and the expression of the ET receptor (ETR) type A and B (ETRA and ETRB) in atrial tissues, with a concomitant increase in ANP secretion. The ETRA or ETRB antagonist, BQ123 (0.3 μmol/L) or BQ788 (0.3 μmol/L), respectively attenuated hypoxia-induced ANP secretion. Both antagonists significantly attenuated the levels of hypoxiainduced atrial phosphorylated (p)-extracellular signal-regulated kinase (ERK) and p-protein kinase B (Akt). The ERK and Akt inhibitors, PD098059 (30 μmol/L) and LY294002 (30 μmol/L), respectively mimicked the effect of the ETR antagonists. These results demonstrated that acute hypoxia- mediated atrial ET-1 regulated ANP secretion through ETR and the subsequent mitogenactivated protein kinase (MAPK)/ERK and ETR-phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways. These pathways may mediate atrial endocrine functions under hypoxic conditions.

Signal Peptide and Denaturing Temperature are Critical Factors for Efficient Mammalian Expression and Immunoblotting of Cannabinoid Receptors

Many researchers employed mammalian expression system to artificially express cannabinoid receptors, but immunoblot data that directly prove efficient protein expression can hardly be seen in related research reports. In present study, we demonstrated cannabinoid receptor protein was not able to be properly expressed with routine mammalian expression system. This inefficient expression was rescued by endowing an exogenous signal peptide ahead of cannabinoid receptor peptide. In addition, the artificially synthesized cannabinoid receptor was found to aggregate under routine sample denaturing temperatures (i.e.,≥95°C), forming a large molecular weight band when analyzed by immuno-blotting. Only denaturing temperatures ≤75°C yielded a clear band at the predicted molecular weight. Collectively, we showed that efficient mammalian expression of cannabinoid receptors need a signal peptide sequence, and described the requirement for a low sample denaturing temperature in immuno-blot analysis. These findings provide very useful information for efficient mammalian expression and immuno-blotting of membrane receptors.

Screening and Identification of a Targeting Peptide to nGLP-1R from Phage Display Peptide Library

In order to provide the structure information for designing new exendin-4 analogues, a phage display peptide library was screened by targeting the N-terminal extracellular domain of GLP-1R（nGLP-1R）. After four rounds of selection, nine sequences were obtained, four of them have higher affinity for nGLP-1R than the others. We chose two of them named X and Y peptides. Islet β-cell proliferation assay suggested that X and Y peptides didn＇t have any activity to increase islet β-cell proliferation. In other words, X and Y peptides were not agonists to GLP-1R. However, the conservative motifs of X and Y peptides provided us useful information to design new exendin-4 analogues.

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.

达格列净联合胰高血糖素样肽-1受体激动剂对2型糖尿病的疗效研究

目的探讨达格列净联合胰高血糖素样肽-1受体激动剂(GLP-1 RAs)对2型糖尿病患者血液流变学及胰岛素抵抗的影响。方法将2020年11月—2022年10月泉州市中医院收治的102例2型糖尿病患者随机分为2组,每组51例。对照组给予达格列净治疗,研究组采用达格列净联合GLP-1 RAs(利拉鲁肽)的治疗方案。比较2组临床疗效、血糖指标[空腹血糖(FBG)、餐后2 h血糖(2 hPG)、糖化血红蛋白(HbA1c)]、空腹胰岛素(FINS)及胰岛素抵抗[胰岛素抵抗指数(HOMA-IR)、胰岛素分泌指数(HOMA-β)]、血脂指标[总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)]、血液流变学指标[红细胞聚集指数(EAI)、红细胞压积(HCT)、红细胞变形指数(EDI)、血浆黏度(PV)]和不良反应。结果研究组总有效率为94.12%,高于对照组的80.39%,差异有统计学意义(P<0.05)。研究组和对照组治疗后FBG、2 hPG、HbAlc、BMI均低于治疗前,且研究组治疗后FBG、2 hPG、HbAlc水平低于对照组,差异有统计学意义(P<0.05)。治疗后,研究组FINS、HOMA-β水平高于对照组,HOMA-IR水平低于对照组,差异有统计学意义(P<0.05)。研究组和对照组治疗后HDL-C均高于治疗前,TC、TG、LDL-C水平均低于治疗前;研究组治疗后HDL-C水平高于对照组,TC、TG、LDL-C水平低于对照组,差异均有统计学意义(P<0.05)。治疗后,研究组和对照组EAI、HCT、EDI、PV水平均低于治疗前,且研究组EAI、HCT、EDI、PV水平低于对照组,差异均有统计学意义(P<0.05)。研究组不良反应总发生率为11.76%,与对照组的9.80%比较,差异无统计学意义(P>0.05)。结论达格列净联合GLP-1 RAs(利拉鲁肽)治疗2型糖尿病的疗效确切,可有效调节患者血糖及血脂水平,缓解胰岛素抵抗,改善血液流变学指标。

胰高血糖素样肽1受体激动剂治疗阿尔茨海默病的潜在靶点预测及验证

背景:阿尔茨海默病的机制探究过程中揭示了生物信息学对共同靶点筛选的重要作用,能够利用其筛选结果为基础,探究药物对该疾病的治疗效果。目的:采用生物信息学与分子生物学等方法预测胰高血糖素样肽1受体激动剂利拉鲁肽治疗阿尔茨海默病的作用靶点。方法:利用DisGeNET数据库及SEA数据库获取阿尔茨海默病和利拉鲁肽作用的共同基因;利用DAVID在线数据库对共同靶点进行GO/KEGG富集分析;使用STRING数据库构建蛋白互作网络;使用CCK-8判断利拉鲁肽的最佳使用剂量;使用免疫荧光和免疫印迹技术对关键蛋白的表达情况进行分析。采用小鼠海马神经元HT22细胞系进行体外实验,细胞被随机分为3组:HT22组、HT22+Aβ组和HT22+Aβ+Lir组。HT22组不做特殊处理,HT22+Aβ组使用Aβ1-42干预HT22细胞系24 h构建Aβ损伤细胞模型,HT22+Aβ+Lir组在HT22+Aβ组的基础上添加利拉鲁肽12 h。结果与结论:①从DisGeNET数据库筛选出阿尔茨海默病相关联的基因,共得到3333个关联基因。再从SEA数据库中,得到利拉鲁肽的潜在作用靶点147个。最后使用R包筛选出阿尔茨海默病与利拉鲁肽共同靶点64个。②用DAVID数据库进行共同靶点的GO/KEGG分析,结果提示共同靶点主要富集在:神经活性配体-受体相互作用、肾素-血管紧张素系统、膀胱癌、内肽酶活性、肽受体活性、G蛋白偶联肽受体活性和转运囊泡等生物进程。③将已经得到的64个共同靶点蛋白导入至SRTING在线数据库进行蛋白互作网络构建,得到排名前3位的基因为基质金属蛋白酶2,9和白细胞介素1β。④采用CCK-8试剂盒检测了培养细胞的活性,确定利拉鲁肽拮抗Aβ1-42的最佳浓度为100 nmol/L。⑤在免疫印迹实验与免疫荧光实验中,较HT22组相比,在HT22+Aβ组内基质金属蛋白酶2,9和白细胞介素1β表达量明显上升(P<0.05);HT22+Aβ+Lir组较HT22+Aβ组相比基质金属蛋白酶2,9和白细胞介素1β的表达量显著下降(P<0.05)。⑥结合上述生物信息学数据及在GEO数据库的差异基因二次验证结果提示,基质金属蛋白酶2,9和白细胞介素1β均可作为利拉鲁肽治疗阿尔茨海默病的潜在作用靶点。

胰高血糖素样肽-1受体激动剂治疗儿童及青少年肥胖的疗效与安全性的系统评价

目的:系统评价胰高血糖素样肽-1(GLP-1)受体激动剂治疗儿童及青少年肥胖的疗效与安全性。方法:计算机检索PubMed、Embase、Web of Science、the Cochrane Library、中国知网、万方数据库、维普数据库中关于GLP-1受体激动剂对比安慰剂治疗儿童及青少年肥胖的随机对照试验(RCT)文献(数据库建库至2023年12月31日),根据纳入与排除标准进行文献筛选和数据提取后,运用RevMan 5.3软件进行Meta分析。结果:共纳入11篇RCT文献,涉及981例儿童及青少年肥胖患者,其中研究组542例(利拉鲁肽227例,艾塞那肽78例,司美格鲁肽134例,度拉糖肽103例),对照组439例。文献偏倚风险中等。Meta分析结果显示,与安慰剂相比,GLP-1受体激动剂可降低儿童及青少年肥胖患者的体重(MD=-3.83,95%CI=-5.94~-1.71,P=0.000 4)、体重指数(BMI)(MD=-1.94,95%CI=-3.17~-0.70,P=0.002)、BMI-Z评分(MD=-0.18,95%CI=-0.33~-0.03,P=0.02)、糖化血红蛋白水平(MD=-0.22,95%CI=-0.38~-0.07,P=0.005)、空腹血糖水平(MD=-4.43,95%CI=-8.18~-0.68,P=0.02),差异均有统计学意义。亚组分析结果显示,周制剂在降低患者体重方面可能不具有优势,但周制剂相比于日制剂能更好地降低患者的BMI、BMI-Z评分;同时,相比于不伴有2型糖尿病的儿童及青少年肥胖患者,GLP-1受体激动剂可以更好地降低伴有2型糖尿病的儿童及青少年肥胖患者的空腹血糖和糖化血红蛋白水平。相对于安慰剂,使用GLP-1受体激动剂的儿童及青少年肥胖患者的恶心(OR=3.13,95%CI=2.23~4.39,P<0.000 01)、呕吐(OR=5.97,95%CI=3.79~9.41,P<0.000 01)、腹泻(OR=1.45,95%CI=1.02~2.06,P=0.04)、头晕(OR=2.68,95%CI=1.36~5.26,P=0.004)等不良反应发生率升高,差异均有统计学意义。结论:GLP-1受体激动剂可降低儿童及青少年肥胖患者的体重、BMI、糖化血红蛋白、空腹血糖水平,但胃肠道不良反应发生率较高,使用时应注意。