Displaying publications 81 - 100 of 139 in total

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  1. Khan MA, Sattar MA, Abdullah NA, Johns EJ
    Acta Pharmacol Sin, 2008 Feb;29(2):193-203.
    PMID: 18215348 DOI: 10.1111/j.1745-7254.2008.00727.x
    This study examined whether alpha1B-adrenoceptors are involved in mediating adrenergically-induced renal vasoconstrictor responses in rats with pathophysiological and normal physiological states.
    Matched MeSH terms: Adrenergic beta-Agonists/pharmacology
  2. Lim WK, Kanelakis KC, Neubig RR
    Cell Signal, 2013 Feb;25(2):389-96.
    PMID: 23153586 DOI: 10.1016/j.cellsig.2012.11.002
    G protein-coupled receptors (GPCRs) transduce extracellular signals to the interior of the cell by activating membrane-bound guanine nucleotide-binding regulatory proteins (G proteins). An increasing number of proteins have been reported to bind to and regulate GPCRs. We report a novel regulation of the alpha(2A) adrenergic receptor (α(2A)-R) by the ubiquitous stress-inducible 70kDa heat shock protein, hsp70. Hsp70, but not hsp90, attenuated G protein-dependent high affinity agonist binding to the α(2A)-R in Sf9 membranes. Antagonist binding was unchanged, suggesting that hsp70 uncouples G proteins from the receptor. As hsp70 did not bind G proteins but complexed with the α(2A)-R in intact cells, a direct interaction with the receptor seems likely. In the presence of hsp70, α(2A)-R-catalyzed [(35)S]GTPγS binding was reduced by approximately 70%. In contrast, approximately 50-fold higher concentrations of hsp70 were required to reduce agonist binding to the stress-inducible 5-hydroxytryptamine(1A) receptor (5-HT(1A)-R). In heat-stressed CHO cells, the α(2A)-R was significantly uncoupled from G proteins, coincident with an increased localization of hsp70 at the membrane. The contrasting effect of hsp70 on the α(2A)-R compared to the 5-HT(1A)-R suggests that during stress, upregulation of hsp70 may attenuate signaling from specific GPCRs as part of the stress response to foster survival.
    Matched MeSH terms: Adrenergic alpha-2 Receptor Agonists/metabolism
  3. Wang S, Liu F, Tan KS, Ser HL, Tan LT, Lee LH, et al.
    J Cell Mol Med, 2020 01;24(1):722-736.
    PMID: 31680470 DOI: 10.1111/jcmm.14780
    Evidence demonstrates that M1 macrophage polarization promotes inflammatory disease. Here, we discovered that (R)-salbutamol, a β2 receptor agonist, inhibits and reprograms the cellular metabolism of RAW264.7 macrophages. (R)-salbutamol significantly inhibited LPS-induced M1 macrophage polarization and downregulated expressions of typical M1 macrophage cytokines, including monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α). Also, (R)-salbutamol significantly decreased the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and reactive oxygen species (ROS), while increasing the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. In contrast, (S)-salbutamol increased the production of NO and ROS. Bioenergetic profiles showed that (R)-salbutamol significantly reduced aerobic glycolysis and enhanced mitochondrial respiration. Untargeted metabolomics analysis demonstrated that (R)-salbutamol modulated metabolic pathways, of which three metabolic pathways, namely, (a) phenylalanine metabolism, (b) the pentose phosphate pathway and (c) glycerophospholipid metabolism were the most noticeably impacted pathways. The effects of (R)-salbutamol on M1 polarization were inhibited by a specific β2 receptor antagonist, ICI-118551. These findings demonstrated that (R)-salbutamol inhibits the M1 phenotype by downregulating aerobic glycolysis and glycerophospholipid metabolism, which may propose (R)-salbutamol as the major pharmacologically active component of racemic salbutamol for the treatment of inflammatory diseases and highlight the medicinal value of (R)-salbutamol.
    Matched MeSH terms: Adrenergic beta-2 Receptor Agonists/pharmacology
  4. Madden L, Bojko MJ, Farnum S, Mazhnaya A, Fomenko T, Marcus R, et al.
    Int J Drug Policy, 2017 11;49:48-53.
    PMID: 28957756 DOI: 10.1016/j.drugpo.2017.07.025
    BACKGROUND: Opioid agonist therapies (OAT) like methadone and buprenorphine maintenance treatment remain markedly under-scaled in Ukraine despite adequate funding. Clinicians and administrators were assembled as part of an implementation science strategy to scale-up OAT using the Network for Improvement of Addiction Treatment (NIATx) approach.

    METHODS: Nominal Group Technique (NGT), a key ingredient of the NIATx toolkit, was directed by three trained coaches within a learning collaborative of 18 OAT clinicians and administrators to identify barriers to increase OAT capacity at the regional "oblast" level, develop solutions, and prioritize local change projects. NGT findings were supplemented from detailed notes collected during the NGT discussion.

    RESULTS: The top three identified barriers included: (1) Strict regulations and inflexible policies dictating distribution and dispensing of OAT; (2) No systematic approach to assessing OAT needs on regional or local level; and (3) Limited funding and financing mechanisms combined with a lack of local/regional control over funding for OAT treatment services.

    CONCLUSIONS: NGT provides a rapid strategy for individuals at multiple levels to work collaboratively to identify and address structural barriers to OAT scale-up. This technique creates a transparent process to address and prioritize complex issues. Targeting these priorities allowed leaders at the regional and national level to advocate collectively for approaches to minimize obstacles and create policies to improve OAT services.

    Matched MeSH terms: Narcotics/agonists*
  5. Safi SZ, Shah H, Qvist R, Bindal P, Mansor M, Yan GOS, et al.
    Cell Physiol Biochem, 2018;51(3):1429-1436.
    PMID: 30485834 DOI: 10.1159/000495591
    BACKGROUND/AIMS: NF-κB induces transcription of a number of genes, associated with inflammation and apoptosis. In this study, we have investigated the effect of β-adrenergic receptor stimulation on NF-κB and IκBα in HUVECs.

    METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in high and low glucose concentrations. All HUVECs were treated with different concentrations of isoproterenol and propranolol for different time periods. The analytical procedures consisted of Western Blot, ELISA, DCFH-DA and TUNEL assays.

    RESULTS: Isoproterenol (agonist of a beta-adrenergic receptor) significantly reduced phosphorylation at Ser-536 of NF-κB; and Ser-32 and Ser-36 of IκBα in hyperglycemic HUVECs. Isoproterenol also significantly reduced apoptosis and ROS generation. No effect of IκBα was observed on Tyr-42 phosphorylation. The effect of isoproterenol was reversed by the antagonist propranolol. We also checked if NF-κB inhibitor MG132 causes any change at the level of apoptosis. However, we observed an almost similar effect.

    CONCLUSION: Given data demonstrates that beta-adrenergic receptors stimulation has a protective effect on HUVECs that might be occuring via NF-κβ and IκBα pathway.

    Matched MeSH terms: Adrenergic beta-Agonists/pharmacology*
  6. Tan SZK, Temel Y, Chan AY, Mok ATC, Perucho JAU, Blokland A, et al.
    Brain Struct Funct, 2020 Sep;225(7):1957-1966.
    PMID: 32594260 DOI: 10.1007/s00429-020-02102-w
    Electrical stimulation of the dorsolateral periaqueductal gray (dlPAG) in rats has been shown to elicit panic-like behaviour and can be a useful as an unconditioned stimulus for modelling anticipatory fear and agoraphobia in a contextual fear conditioning paradigm. In this study, we further analysed our previous data on the effects of escitalopram (a selective serotonin reuptake inhibitor, SSRI) and buspirone (a 5-HT1A receptor partial agonist) on dlPAG-induced anticipatory fear behaviour in a rat model using freezing as a measure. We then attempted to unravel some of the interactions with dopamine signalling using tyrosine hydroxylase (TH) immunohistochemistry to probe the effects on dopaminergic neurons. We showed that acute treatment of escitalopram, but not buspirone, was effective in reducing anticipatory freezing behaviour, while chronic administrations of both drugs were effective. We found that the dlPAG stimulation induced increase number of dopaminergic neurons in the ventral tegmental area (VTA) which was reversed in both chronic buspirone and escitalopram groups. We further found a strong positive correlation between the number of dopaminergic neurons and freezing in the VTA and showed positive correlations between dopaminergic neurons in the VTA and substantia nigra pars compacta (SNpc) in escitalopram and buspirone groups, respectively. Overall, we showed that chronic treatment with an SSRI and a 5-HT1A agonist reduced anticipatory freezing behaviour which seems to be associated, through correlative studies, with a reversal of dlPAG stimulation induced increase in number of dopaminergic neurons in the VTA and/or SNpc.
    Matched MeSH terms: Serotonin Receptor Agonists/pharmacology*
  7. Chai BK, Lau YS, Loong BJ, Rais MM, Ting KN, Dharmani DM, et al.
    Physiol Res, 2018 Nov 14;67(5):729-740.
    PMID: 29750886
    The cis(c)-9, trans(t)-11 (c9,t11) and t10,c12 isomers of conjugated linoleic acid (CLA) have been reported as agonists of peroxisome proliferator-activated receptor (PPAR) and beneficial in lipidemia and glycemia. However, it is unclear whether CLA isomers enhance or antagonize effects of conventional drugs targeting PPAR. Male Sprague-Dawley rats were fed high fat diet (HFD) for 8 weeks and treated without or with CLA, rosiglitazone or both for 4 weeks. Oral glucose tolerance and surrogate markers of insulin resistance were not significantly different for all treatments compared to untreated normal diet (ND) or HFD group, except lipoprotein levels. The combination of CLA and rosiglitazone had suppressed levels of low and high density lipoproteins (46 % and 25 %, respectively), compared to HFD-alone. Conversely, the atherogenic co-efficient of the animals received HFD or HFD+rosiglitazone+CLA was 2-folds higher than ND, HFD+rosiglitazone or HFD+CLA. Isolated aortic rings from the combined CLA and rosiglitazone treated animals were less sensitive to isoprenaline-induced relaxation among endothelium-denuded aortas with a decreased efficacy and potency (R(max)=53+/-4.7 %; pEC50=6+/-0.2) compared to endothelium-intact aortas (R(max)=100+/-9.9 %; pEC50=7+/-0.2). Our findings illustrate that the combination of CLA and rosiglitazone precede the atherogenic state with impaired endothelium-independent vasodilatation before the onset of HFD-induced insulin resistance.
    Matched MeSH terms: Adrenergic beta-Agonists/pharmacology
  8. Ibrahim NNIN, Rasool AHG
    Skin Res Technol, 2017 Aug;23(3):321-325.
    PMID: 27868242 DOI: 10.1111/srt.12338
    BACKGROUND: Pulse wave analysis (PWA) and laser Doppler fluximetry (LDF) are non-invasive methods of assessing macrovascular endothelial function and microvascular reactivity respectively. The aim of this study was to assess the correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF.

    METHOD: 297 healthy and non-smoking subjects (159 females, mean age (±SD) 23.56 ± 4.54 years) underwent microvascular reactivity assessment using LDF followed by macrovascular endothelial function assessments using PWA.

    RESULTS: Pearson's correlation showed no correlation between macrovascular endothelial function and microvascular reactivity (r = -0.10, P = 0.12).

    CONCLUSION: There was no significant correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF in healthy subjects.

    Matched MeSH terms: Adrenergic beta-2 Receptor Agonists/pharmacology
  9. Nam HY, Balaji Raghavendran HR, Pingguan-Murphy B, Abbas AA, Merican AM, Kamarul T
    PLoS One, 2017;12(6):e0178117.
    PMID: 28654695 DOI: 10.1371/journal.pone.0178117
    The role for mechanical stimulation in the control of cell fate has been previously proposed, suggesting that there may be a role of mechanical conditioning in directing mesenchymal stromal cells (MSCs) towards specific lineage for tissue engineering applications. Although previous studies have reported that calcium signalling is involved in regulating many cellular processes in many cell types, its role in managing cellular responses to tensile loading (mechanotransduction) of MSCs has not been fully elucidated. In order to establish this, we disrupted calcium signalling by blocking stretch-activated calcium channel (SACC) in human MSCs (hMSCs) in vitro. Passaged-2 hMSCs were exposed to cyclic tensile loading (1 Hz + 8% for 6, 24, 48, and 72 hours) in the presence of the SACC blocker, gadolinium. Analyses include image observations of immunochemistry and immunofluorescence staining from extracellular matrix (ECM) production, and measuring related tenogenic and apoptosis gene marker expression. Uniaxial tensile loading increased the expression of tenogenic markers and ECM production. However, exposure to strain in the presence of 20 μM gadolinium reduced the induction of almost all tenogenic markers and ECM staining, suggesting that SACC acts as a mechanosensor in strain-induced hMSC tenogenic differentiation process. Although cell death was observed in prolonged stretching, it did not appear to be apoptosis mediated. In conclusion, the knowledge gained in this study by elucidating the role of calcium in MSC mechanotransduction processes, and that in prolonged stretching results in non-apoptosis mediated cell death may be potential useful for regenerative medicine applications.
    Matched MeSH terms: Calcium Channel Agonists/pharmacology*
  10. Kosni NN, Ganti N, Noor MH, Razak IS, Ajat MM, Omar AR
    J Cancer Res Ther, 2016 Apr-Jun;12(2):590-6.
    PMID: 27461615 DOI: 10.4103/0973-1482.146066
    BACKGROUND: Complement system is theoretically believed to halt the progression of tumor by the activity of C5a/CD88. Protein C5a is a potent pro.inflammatory mediator that activates the complement system by binding to its receptor.
    OBJECTIVES: The purpose of this study is to determine the expression of the anaphylatoxin C5a receptor on 4T1 cell line and to study the viability of the cells after being treated with the C5a peptides.
    MATERIALS AND METHODS: The cells 4T1 had undergone immunofluorescence staining, conventional polymerase chain reaction (PCR) and real-time PCR for the expression of determination part. Whereas Alamar Blue and MTT assays were conducted for the viability study of the cells.
    RESULTS: The cells showed positive result in expressing the receptor of the C5a through immunostaining and PCR. The CT value recorded at initial dilution was 22.24. In cell viability assay, the cell was treated with C5a peptides, PMX205 and EP54. The purpose of this treatment was to see whether C5a had a direct effect on the cell itself using both assays. The result showed that PMX205, which is an antagonist, gave more effects towards the cell as compared with the treatment of EP54.
    CONCLUSION: This experiment shows the presence of C5a receptor on 4T1 cell line. We believe that the antagonist peptide is eligible to be used widely in cancer immunotherapy field; but in vivo studies need to be carried out first in the future, as it will determine how these drugs affect the tumor cell growth.
    Matched MeSH terms: Receptor, Anaphylatoxin C5a/antagonists & inhibitors; Receptor, Anaphylatoxin C5a/agonists
  11. Ab Ghani NS, Ramlan EI, Firdaus-Raih M
    Nucleic Acids Res, 2019 07 02;47(W1):W350-W356.
    PMID: 31106379 DOI: 10.1093/nar/gkz391
    A common drug repositioning strategy is the re-application of an existing drug to address alternative targets. A crucial aspect to enable such repurposing is that the drug's binding site on the original target is similar to that on the alternative target. Based on the assumption that proteins with similar binding sites may bind to similar drugs, the 3D substructure similarity data can be used to identify similar sites in other proteins that are not known targets. The Drug ReposER (DRug REPOSitioning Exploration Resource) web server is designed to identify potential targets for drug repurposing based on sub-structural similarity to the binding interfaces of known drug binding sites. The application has pre-computed amino acid arrangements from protein structures in the Protein Data Bank that are similar to the 3D arrangements of known drug binding sites thus allowing users to explore them as alternative targets. Users can annotate new structures for sites that are similarly arranged to the residues found in known drug binding interfaces. The search results are presented as mappings of matched sidechain superpositions. The results of the searches can be visualized using an integrated NGL viewer. The Drug ReposER server has no access restrictions and is available at http://mfrlab.org/drugreposer/.
    Matched MeSH terms: Proteins/antagonists & inhibitors; Proteins/agonists
  12. Chua P, Lim WK
    Sci Rep, 2021 04 14;11(1):8096.
    PMID: 33854099 DOI: 10.1038/s41598-021-87431-4
    Stroke causes death and disability globally but no neuroprotectant is approved for post-stroke neuronal injury. Neuroprotective compounds can be identified using oxygen glucose deprivation (OGD) of neuronal cells as an in vitro stroke model. Nerve growth factor (NGF)-differentiated PC12 pheochromocytoma cells are frequently used. However, investigators often find their clonal variant undifferentiable and are uncertain of optimal culture conditions. Hence we studied 3 commonly used PC12 variants: PC12 Adh, PC12 from Riken Cell Bank (PC12 Riken) and Neuroscreen-1 (NS-1) cells. We found DMEM the optimal media for PC12 Riken and NS-1 cells. Using a novel serum-free media approach, we identified collagen IV as the preferred adhesive substrate for both cell lines. We found PC12 Adh cells cannot attach without serum and is unable to differentiate using NGF. NS-1 cells differentiated to a maximal 72.7 ± 5.2% %, with substantial basal differentiation. We optimised differentiated NS-1 cells for an in vitro stroke model using 3 h of OGD resulting in ~ 70% viable cells. We screened 5 reported neuroprotectants and provide the first report that serotonin is antiapoptotic in a stroke model and the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) is neuroprotective in PC12 cells. Thus we demonstrate the optimisation and validation for a PC12 cell-based in vitro stroke model.
    Matched MeSH terms: Serotonin 5-HT1 Receptor Agonists/pharmacology
  13. Khor KH, Shiels IA, Campbell FE, Greer RM, Rose A, Mills PC
    Vet J, 2014 Feb;199(2):229-35.
    PMID: 24321367 DOI: 10.1016/j.tvjl.2013.11.006
    Analysis of heart rate (HR) and heart rate variability (HRV) are powerful tools to investigate cardiac diseases, but current methods, including 24-h Holter monitoring, can be cumbersome and may be compromised by movement artefact. A commercially available data capture and analysis system was used in anaesthetised healthy cats to measure HR and HRV during pharmacological manipulation of HR. Seven healthy cats were subjected to a randomised crossover study design with a 7 day washout period between two treatment groups, placebo and atenolol (1mg/kg, IV), with the efficacy of atenolol to inhibit β1 adrenoreceptors challenged by epinephrine. Statistical significance for the epinephrine challenge was set at P<0.0027 (Holm-Bonferroni correction), whereas a level of significance of P<0.05 was set for other variables. Analysis of the continuous electrocardiography (ECG) recordings showed that epinephrine challenge increased HR in the placebo group (P=0.0003) but not in the atenolol group. The change in HR was greater in the placebo group than in the atenolol group (P=0.0004). Therefore, compared to cats pre-treated with placebo, pre-treatment with atenolol significantly antagonised the tachycardia while not significantly affecting HRV. The increased HR in the placebo group following epinephrine challenge was consistent with a shift of the sympathovagal balance towards a predominantly sympathetic tone. However, the small (but not significant at the critical value) decrease in the normalised high-frequency component (HFnorm) in both groups of cats suggested that epinephrine induced a parasympathetic withdrawal in addition to sympathetic enhancement (increased normalised low frequency component or LFnorm). In conclusion, this model is a highly sensitive and repeatable model to investigate HRV in anaesthetised cats that would be useful in the laboratory setting for short-term investigation of cardiovascular disease and subtle responses to pharmacological agents in this species.
    Matched MeSH terms: Adrenergic beta-1 Receptor Agonists/pharmacology
  14. Mohamad NV, Soelaiman IN, Chin KY
    Endocr Metab Immune Disord Drug Targets, 2017 Nov 16;17(4):276-284.
    PMID: 28925899 DOI: 10.2174/1871530317666170919112757
    BACKGROUND AND OBJECTIVE: Prostate cancer is the most prevalent non-cutaneous cancer in men, which causes significant mortality among the patients. Since prostate cancer cells are stimulated by androgen, effective androgen ablation in men is one of the essential strategies in the management of prostate cancer.

    DISCUSSION: Several treatment options are available for different stages of prostate cancer. Hormone therapy known as androgen deprivation therapy (ADT) is the first line treatment used to treat advanced prostate cancer. Chemical castration by gonadotropin-releasing hormone agonists suppresses lutenizing hormone production, which in turn inhibits the production of testosterone and dihydrotestosterone. This will prevent the growth of prostate cancer cells. However, ADT causes deleterious effects on bone health because the androgens are essential in preserving optimal bone health in men.

    CONCLUSION: Various observational studies showed that long-term ADT for advanced or metastatic prostate cancer was associated with decreased bone mineral density, as well as altered body composition that might affect bone health. Considering the potential impact of osteoporotic fracture, interventions to mitigate these skeletal adverse effects should be considered by physicians when initiating ADT on their patients.

    Matched MeSH terms: Androgen Antagonists/pharmacology; Androgen Antagonists/therapeutic use*; Gonadotropin-Releasing Hormone/agonists
  15. Yusoff NHM, Mansor SM, Müller CP, Hassan Z
    Behav Brain Res, 2018 06 01;345:65-71.
    PMID: 29499286 DOI: 10.1016/j.bbr.2018.02.039
    Mitragynine is the major alkaloid found in the leaves of M. speciosa Korth (Rubiaceae), a plant that is native to Southeast Asia. This compound has been used, either traditionally or recreationally, due to its psychostimulant and opioid-like effects. Recently, mitragynine has been shown to exert conditioned place preference (CPP), indicating the rewarding and motivational properties of M. speciosa. Here, the involvement of GABAB receptors in mediating mitragynine reward is studied using a CPP paradigm in rats. First, we examined the effects of GABAB receptor agonist baclofen (1.25, 2.5 and 5 mg/kg) on the acquisition of mitragynine (10 mg/kg)-induced CPP. Second, the involvement of GABAB receptors in the expression of mitragynine-induced CPP was tested. We found that the acquisition of mitragynine-induced CPP could be blocked by higher doses (2.5 and 5 mg/kg) of baclofen. Baclofen at a high dose inhibited locomotor activity and caused a CPP. Furthermore, we found that baclofen (2.5 and 5 mg/kg) also blocked the expression of mitragynine-induced CPP. These findings suggest that both, the acquisition and expression of mitragynine's reinforcing properties is controlled by the GABAB receptor.
    Matched MeSH terms: GABA-B Receptor Agonists/pharmacology*
  16. Mohamad NV, Che Zulkepli MAA, May Theseira K, Zulkifli N, Shahrom NQ, Ridzuan NAM, et al.
    Int J Med Sci, 2018;15(4):300-308.
    PMID: 29511366 DOI: 10.7150/ijms.22732
    Introduction: Orchidectomy is currently the preferred method to induce bone loss in preclinical male osteoporosis model. Gonadotropin-releasing hormone (GnRH) agonists used in prostate cancer treatment can induce testosterone deficiency but its effects on bone in preclinical male osteoporosis model are less studied. Objective: This study aimed to evaluate the skeletal effect of buserelin (a GnRH agonist) in male rats and compare it with orchidectomy. Methods: Forty-six three-month-old male Sprague-Dawley rats were divided into three experimental arms. The baseline arm (n=6) was sacrificed at the onset of the study. In the buserelin arm, the rats received a daily subcutaneous injection of either normal saline (n=8), buserelin acetate at 25 µg/kg (n=8) or 75 µg/kg (n=8). In the orchidectomy arm, the rats were either sham-operated (n=8) or orchidectomized (n=8). All groups underwent in-vivo X-ray micro-computed tomography scanning at the left proximal tibia every month. Blood was collected at the beginning and the end of the study for testosterone level evaluation. The rats were euthanized after the three-month treatment. The femurs were harvested for biomechanical strength and bone calcium determination. Results: The results showed that buserelin at both doses caused a significant decline in testosterone level and deterioration in bone microstructure (p<0.05), but did not affect bone calcium content (p>0.05). Buserelin at 25 µg/kg decreased displacement and strain of the femur significantly (p<0.05). Similar changes were observed in the orchidectomized group compared to the sham-operated group but without any significant changes in biomechanical strength (p>0.05). Conclusion: Buserelin can induce testosterone deficiency and the associated deterioration of bone microarchitecture similar to orchidectomy in three months. However, it may require a longer time to show significant effects on bone strength and mineral content.
    Matched MeSH terms: Gonadotropin-Releasing Hormone/agonists
  17. Safi SZ, Saeed L, Shah H, Latif Z, Ali A, Imran M, et al.
    Mol Biol Rep, 2022 Oct;49(10):9473-9480.
    PMID: 35925485 DOI: 10.1007/s11033-022-07816-0
    BACKGROUND: The current study aimed to investigate the stimulatory effect of beta-adrenergic receptors (β-ARs) on brain derived neurotropic factor (BDNF) and cAMP response element binding protein (CREB).

    METHODS: Human Müller cells were cultured in low and high glucose conditions. Cells were treated with xamoterol (selective agonist for β1-AR), salmeterol (selective agonist for β2-AR), isoproterenol (β-ARs agonist) and propranolol (β-ARs antagonist), at 20 µM concentration for 24 h. Western Blotting assay was performed for the gene expression analysis. DNA damage was evaluated by TUNEL assay. DCFH-DA assay was used to check the level of reactive oxygen species (ROS). Cytochrome C release was measured by ELISA.

    RESULTS: Xamoterol, salmeterol and isoproterenol showed no effect on Caspase-8 but it reduced the apoptosis and increased the expression of BDNF in Müller cells. A significant change in the expression of caspase-3 was observed in cells treated with xamoterol and salmeterol as compared to isoproterenol. Xamoterol, salmeterol and isoproterenol significantly decreased the reactive oxygen species (ROS) when treated for 24 hours. Glucose-induced cytochrome c release was disrupted in Müller cells.

    CONCLUSION: β-ARs, stimulated by agonist play a protective role in hyperglycemic Müller cells, with the suppression of glucose-induced caspase-3 and cytochrome c release. B-Ars may directly mediate the gene expression of BDNF.

    Matched MeSH terms: Adrenergic beta-Agonists/pharmacology
  18. Ni H, Moe S, Soe Z, Myint KT, Viswanathan KN
    Cochrane Database Syst Rev, 2018 Dec 11;12(12):CD011594.
    PMID: 30536566 DOI: 10.1002/14651858.CD011594.pub2
    BACKGROUND: Several dual bronchodilator combinations of long-acting beta2-agonist (LABA) and long-acting muscarinic antagonist (LAMA) have been approved for treatment of stable chronic obstructive pulmonary disease (COPD). The current GOLD (Global Initiative for Chronic Obstructive Lung Disease) recommendations suggest the use of LABA/LAMA combinations in people with group B COPD with persistent symptoms, group C COPD with further exacerbations on LAMA therapy alone and group D COPD with or without inhaled corticosteroids (ICS). Fixed-dose combination (FDC) of aclidinium/formoterol is one of the approved LABA/LAMA therapies for people with stable COPD.

    OBJECTIVES: To assess the efficacy and safety of combined aclidinium bromide and long-acting beta2-agonists in stable COPD.

    SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, World Health Organization (WHO) trials portal, United States Food and Drug Administration (FDA) and manufacturers' websites as well as the reference list of published trials up to 12 October 2018.

    SELECTION CRITERIA: Parallel-group randomised controlled trials (RCTs) assessing combined aclidinium bromide and LABAs in people with stable COPD.

    DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane for data collection and analysis. The primary outcomes were exacerbations requiring a short course of an oral steroid or antibiotic, or both; quality of life measured by a validated scale and non-fatal serious adverse events (SAEs). Where the outcome or study details were not reported, we contacted the study investigators or pharmaceutical company trial co-ordinators (or both) for missing data.

    MAIN RESULTS: We identified RCTs comparing aclidinium/formoterol FDC versus aclidinium, formoterol or placebo only. We included seven multicentre trials of four to 52 weeks' duration conducted in outpatient settings. There were 5921 participants, whose mean age ranged from 60.7 to 64.7 years, mostly men with a mean smoking pack-years of 46.4 to 61.3 of which 43.9% to 63.4% were current smokers. They had a moderate-to-severe degree of COPD with a mean postbronchodilator forced expiratory volume in one second (FEV1) between 50.5% and 61% of predicted normal and the baseline mean FEV1 of 1.23 L to 1.43 L. We assessed performance and detection biases as low for all studies whereas selection, attrition and reporting biases were either low or unclear.FDC versus aclidiniumThere was no evidence of a difference between FDC and aclidinium for exacerbations requiring steroids or antibiotics, or both (OR 0.95, 95% CI 0.71 to 1.27; 2 trials, 2156 participants; moderate-certainty evidence); quality of life measured by St George's Respiratory Questionnaire (SGRQ) total score (MD -0.92, 95% CI -2.15 to 0.30); participants with significant improvement in SGRQ score (OR 1.17, 95% CI 0.97 to 1.41; 2 trials, 2002 participants; moderate-certainty evidence); non-fatal SAE (OR 1.19, 95% CI 0.79 to 1.80; 3 trials, 2473 participants; moderate-certainty evidence); hospital admissions due to severe exacerbations (OR 0.62, 95% CI 0.29 to 1.29; 2 trials, 2156 participants; moderate-certainty evidence) or adverse events (OR 0.95, 95% CI 0.76 to 1.18; 3 trials, 2473 participants; moderate-certainty evidence). Compared with aclidinium, FDC improved symptoms (Transitional Dyspnoea Index (TDI) focal score: MD 0.37, 95% CI 0.07 to 0.68; 2 trials, 2013 participants) with a higher chance of achieving a minimal clinically important difference (MCID) of at least one unit improvement (OR 1.34, 95% CI 1.11 to 1.62; high-certainty evidence); the number needed to treat for an additional beneficial outcome (NNTB) being 14 (95% CI 9 to 39).FDC versus formoterolWhen compared to formoterol, combination therapy reduced exacerbations requiring steroids or antibiotics, or both (OR 0.78, 95% CI 0.62 to 0.99; 3 trials, 2694 participants; high-certainty evidence); may decrease SGRQ total score (MD -1.88, 95% CI -3.10 to -0.65; 2 trials, 2002 participants; low-certainty evidence; MCID for SGRQ is 4 units); increased TDI focal score (MD 0.42, 95% CI 0.11 to 0.72; 2 trials, 2010 participants) with more participants attaining an MCID (OR 1.30, 95% CI 1.07 to 1.56; high-certainty evidence) and an NNTB of 16 (95% CI 10 to 60). FDC lowered the risk of adverse events compared to formoterol (OR 0.78, 95% CI 0.65 to 0.93; 5 trials, 3140 participants; high-certainty evidence; NNTB 22). However, there was no difference between FDC and formoterol for hospital admissions, all-cause mortality and non-fatal SAEs.FDC versus placeboCompared with placebo, FDC demonstrated no evidence of a difference in exacerbations requiring steroids or antibiotics, or both (OR 0.82, 95% CI 0.60 to 1.12; 2 trials, 1960 participants; moderate-certainty evidence) or hospital admissions due to severe exacerbations (OR 0.55, 95% CI 0.25 to 1.18; 2 trials, 1960 participants; moderate-certainty evidence), although estimates were uncertain. Quality of life measure by SGRQ total score was significantly better with FDC compared to placebo (MD -2.91, 95% CI -4.33 to -1.50; 2 trials, 1823 participants) resulting in a corresponding increase in SGRQ responders who achieved at least four units decrease in SGRQ total score (OR 1.72, 95% CI 1.39 to 2.13; high-certainty evidence) with an NNTB of 7 (95% CI 5 to 12). FDC also improved symptoms measured by TDI focal score (MD 1.32, 95% CI 0.96 to 1.69; 2 studies, 1832 participants) with more participants attaining at least one unit improvement in TDI focal score (OR 2.51, 95% CI 2.02 to 3.11; high-certainty evidence; NNTB 4). There were no differences in non-fatal SAEs, adverse events and all-cause mortality between FDC and placebo.Combination therapy significantly improved trough FEV1 compared to aclidinium, formoterol or placebo.

    AUTHORS' CONCLUSIONS: FDC improved dyspnoea and lung function compared to aclidinium, formoterol or placebo, and this translated into an increase in the number of responders on combination treatment. Quality of life was better with combination compared to formoterol or placebo. There was no evidence of a difference between FDC and monotherapy or placebo for exacerbations, hospital admissions, mortality, non-fatal SAEs or adverse events. Studies reported a lower risk of moderate exacerbations and adverse events with FDC compared to formoterol; however, larger studies would yield a more precise estimate for these outcomes.

    Matched MeSH terms: Adrenergic beta-2 Receptor Agonists/therapeutic use*
  19. Afzal S, Abdul Sattar M, Johns EJ, Eseyin OA
    PLoS One, 2020;15(11):e0229803.
    PMID: 33170841 DOI: 10.1371/journal.pone.0229803
    Pioglitazone, a therapeutic drug for diabetes, possesses full PPAR-γ agonist activity and increase circulating adiponectin plasma concentration. Plasma adiponectin concentration decreases in hypertensive patients with renal dysfunctions. Present study investigated the reno-protective, altered excretory functions and renal haemodynamic responses to adrenergic agonists and ANG II following separate and combined therapy with pioglitazone in diabetic model of hypertensive rats. Pioglitazone was given orally [10mg/kg/day] for 28 days and adiponectin intraperitoneally [2.5μg/kg/day] for last 7 days. Groups of SHR received either pioglitazone or adiponectin in combination. A group of Wistar Kyoto rats [WKY] served as normotensive controls, whereas streptozotocin administered SHRs served as diabetic hypertensive rats. Metabolic data and plasma samples were taken on day 0, 8, 21 and 28. In acute studies, the renal vasoconstrictor actions of Angiotensin II [ANGII], noradrenaline [NA], phenylephrine [PE] and methoxamine [ME] were determined. Diabetic SHRs control had a higher basal mean arterial blood pressure than the WKY, lower RCBP and plasma adiponectin, higher creatinine clearance and urinary sodium excretion compared to WKY [all P<0.05] which were normalized by the individual drug treatments and to greater degree following combined treatment. Responses to intra-renal administration of NA, PE, ME and ANGII were larger in diabetic SHR than WKY and SHRs [P<0.05]. Adiponectin significantly blunted responses to NA, PE, ME and ANG II in diabetic treated SHRs by 40%, whereas the pioglitazone combined therapy with adiponectin further attenuated the responses to adrenergic agonists by 65%. [all P <0.05]. These findings suggest that adiponectin possesses renoprotective effects and improves renal haemodynamics through adiponectin receptors and PPAR-γ in diabetic SHRs, suggesting that synergism exists between adiponectin and pioglitazone. A cross-talk relationship also supposed to exists between adiponectin receptors, PPAR-γ and alpha adrenoceptors in renal vasculature of diabetic SHRs.
    Matched MeSH terms: Adrenergic Agonists
  20. Rasheed ZBM, Lee YS, Kim SH, Rai RK, Ruano CSM, Anucha E, et al.
    Front Immunol, 2020;11:1899.
    PMID: 32983111 DOI: 10.3389/fimmu.2020.01899
    Background: Infection/inflammation is an important causal factor in spontaneous preterm birth (sPTB). Most mechanistic studies have concentrated on the role of bacteria, with limited focus on the role of viruses in sPTB. Murine studies support a potential multi-pathogen aetiology in which a double or sequential hit of both viral and bacterial pathogens leads to a higher risk preterm labour. This study aimed to determine the effect of viral priming on bacterial induced inflammation in human in vitro models of ascending and haematogenous infection. Methods: Vaginal epithelial cells, and primary amnion epithelial cells and myocytes were used to represent cell targets of ascending infection while interactions between peripheral blood mononuclear cells (PBMCs) and placental explants were used to model systemic infection. To model the effect of viral priming upon the subsequent response to bacterial stimuli, each cell type was stimulated first with a TLR3 viral agonist, and then with either a TLR2 or TLR2/6 agonist, and responses compared to those of each agonist alone. Immunoblotting was used to detect cellular NF-κB, AP-1, and IRF-3 activation. Cellular TLR3, TLR2, and TLR6 mRNA was quantified by RT-qPCR. Immunoassays were used to measure supernatant cytokine, chemokine and PGE2 concentrations. Results: TLR3 ("viral") priming prior to TLR2/6 agonist ("bacterial") exposure augmented the pro-inflammatory, pro-labour response in VECs, AECs, myocytes and PBMCs when compared to the effects of agonists alone. In contrast, enhanced anti-inflammatory cytokine production (IL-10) was observed in placental explants. Culturing placental explants in conditioned media derived from PBMCs primed with a TLR3 agonist enhanced TLR2/6 agonist stimulated production of IL-6 and IL-8, suggesting a differential response by the placenta to systemic inflammation compared to direct infection as a result of haematogenous spread. TLR3 agonism generally caused increased mRNA expression of TLR3 and TLR2 but not TLR6. Conclusion: This study provides human in vitro evidence that viral infection may increase the susceptibility of women to bacterial-induced sPTB. Improved understanding of interactions between viral and bacterial components of the maternal microbiome and host immune response may offer new therapeutic options, such as antivirals for the prevention of PTB.
    Matched MeSH terms: Toll-Like Receptor 2/agonists*; Toll-Like Receptor 3/agonists*; Toll-Like Receptor 6/agonists*
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