The pharmacology of CGRP-responsive receptors in cultured and transfected cells

Hay, Debbie L.; Conner, Alex C.; Howitt, Stephen G; Takhshid, Mohammad Ali; Simms, John; Mahmoud, Kamel Z.; Poyner, David R.

doi:10.1016/j.peptides.2004.06.007

Cited by 26 publications

(25 citation statements)

References 43 publications

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“…However, despite the proposed role for AM and CGRP in various pathologies, the therapeutic potential of regulating their action in humans remains unclear. This is a result of the limited information about the distribution of endogenous AM and CGRP receptors, as well as mechanisms regulating their function (Hay et al, 2004;Kuwasako et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…However, no interaction of either peptide with EndoCL in vascular cells has yet been demonstrated. Furthermore, whereas pharmacological studies suggest the heterogeneity among endogenous AM and CGRP receptors, their nature, and a role for CL in particular, remains unclear (reviewed by Sexton et al, 2001) (Poyner et al, 2002;Kuwasako et al, 2004;Hay et al, 2004). For example, the CL-RAMP1 heterodimer matches the pharmacology of the CGRP 1 receptor in cell lines and tissues, and is mainly characterised by high affinity for CGRP antagonists such as CGRP and BIBN4096BS (Poyner et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

“…However, in some tissues, another CGRP-responsive receptor is present, the CGRP 2 receptor, which has a low affinity for CGRP antagonists. There is no simple molecular correlate for this receptor, but it has been suggested that the phenotype might be a result of expression of complexes such as CL-RAMP3 (AM2 receptor), since it has appreciable affinity to CGRP 8-37 (Hay et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Adrenomedullin and CGRP interact with endogenous calcitonin-receptor-like receptor in endothelial cells and induce its desensitisation by different mechanisms

Nikitenko

Blucher

Fox

et al. 2006

Journal of Cell Science

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Adrenomedullin (AM) and calcitonin gene-related peptide (CGRP) are related peptides with distinct pharmacological profiles. Calcitonin-receptor-like receptor (CRLR, now known as CL) can function as either an AM receptor or a CGRP receptor, when cotransfected with receptor-activity-modifying proteins (RAMPs) that define ligand-binding specificity. The aim of the present study was to determine the role of endogenously expressed CL (EndoCL) in generating endogenous AM and CGRP receptors. We raised anti-human CL antibody and identified microvascular endothelial cells (MVECs) as a major CL-expressing cell type in tissues by immunohistochemistry. Cultured MVECs continue to express EndoCL as well as fully active endogenous AM- and CGRP-sensitive receptors in vitro, as demonstrated by the ability of both peptides to induce migration and Akt phosphorylation. We therefore tested the hypothesis that endothelial EndoCL can interact with both AM and CGRP by examining receptor internalisation and desensitisation (loss of the ability to induce Akt phosphorylation). We found that agonist-mediated internalisation of EndoCL occurs in response to AM but not CGRP in MVECs. However, AM-induced EndoCL internalisation was blocked by antagonists of both AM and CGRP receptors: AM22-52 and CGRP8-37, respectively. Furthermore, AM-induced EndoCL internalisation resulted in desensitisation not only of AM but also of CGRP receptors. Finally, CGRP also induced desensitisation of both endogenous AM and CGRP receptors, but did not mediate EndoCL internalisation despite interaction with this receptor. Thus, EndoCL interacts with both AM and CGRP, and simultaneously acts as a receptor for both peptides (i.e acting as an endogenous AM/CGRP receptor) in endothelial cells. Interaction with either ligand is sufficient to induce EndoCL desensitisation to both AM and CGRP, but differential mechanisms are involved since only AM induces EndoCL internalisation. These novel findings regarding regulation of EndoCL function in endothelial cells are likely to be of importance in conditions where AM or CGRP levels are elevated, such as cardiovascular disease, diabetes and inflammation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Adrenomedullin and CGRP interact with endogenous calcitonin-receptor-like receptor in endothelial cells and induce its desensitisation by different mechanisms

Nikitenko

Blucher

Fox

et al. 2006

Journal of Cell Science

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“…Moreover, pharmacological studies with the most well characterized receptor⅐RAMP pairs, CLR⅐RAMP1-3 and calcitonin⅐RAMP1-3, demonstrate varying degrees of overlap in the absolute ligand binding affinity imparted by the different RAMPs. For example, CLR⅐RAMP1-3 complexes can all bind AM or CGRP but with different affinities (11)(12)(13), and calcitonin⅐RAMP1-3 complexes can form amylin receptors with highly variable affinities (3,14) or CGRP receptors (15,16), depending on the cell type studied. Thus, it remains unclear to what degree the three mammalian RAMPs have overlapping functions or whether they can functionally compensate for each other in vivo.…”

mentioning

confidence: 99%

Receptor Activity-modifying Proteins 2 and 3 Have Distinct Physiological Functions from Embryogenesis to Old Age

Dackor

Kim

Smithies

et al. 2007

Journal of Biological Chemistry

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RAMPs (receptor activity modifying proteins) impart remarkable effects on G protein-coupled receptor (GPCR) signaling. First identified through an interaction with the calcitonin receptor-like receptor (CLR), these single transmembrane proteins are now known to modulate the in vitro ligand binding affinity, trafficking, and second messenger pathways of numerous GPCRs. Consequently, the receptor-RAMP interface represents an attractive pharmacological target for the treatment of disease. Although the three known mammalian RAMPs differ in their sequences and tissue expression, results from in vitro biochemical and pharmacological studies suggest that they have overlapping effects on the GPCRs with which they interact. Therefore, to determine whether RAMP2 and RAMP3 have distinct functions in vivo, we generated mice with targeted deletions of either the RAMP2 or RAMP3 gene. Strikingly, we found that, although RAMP2 is required for survival, mice that lack RAMP3 appear normal until old age, at which point they have decreased weight. In addition, mice with reduced expression of RAMP2 (but not RAMP3) display remarkable subfertility. Thus, each gene has functions in vivo that cannot be accomplished by the other. Because RAMP2, RAMP3, and CLR transduce the signaling of the two potent vasodilators adrenomedullin and calcitonin gene-related peptide, we tested the effects of our genetic modifications on blood pressure, and no effects were detected. Nevertheless, our studies reveal that RAMP2 and RAMP3 have distinct physiological functions throughout embryogenesis, adulthood, and old age, and the mice we have generated provide novel genetic tools to further explore the utility of the receptor-RAMP interface as a pharmacological target.The identification of receptor activity modifying proteins (RAMPs) 2 1-3 has revolutionized our current understanding of the mechanism through which class II G protein-coupled receptors (GPCRs) bind to their peptide ligands. First identified in association with the calcitonin receptor-like receptor (CLR; formerly called CRLR), either of these three single pass transmembrane proteins can bind to a GPCR, chaperone it to the plasma membrane, and alter the ligand binding affinity of the receptor (1). For example, a CLR⅐RAMP1 complex preferentially and specifically binds to calcitonin gene-related peptide (CGRP), whereas a CLR⅐RAMP2 or CLR⅐RAMP3 complex will preferentially bind to adrenomedullin (AM), another peptide vasodilator. Thus, the different spatial and temporal expression patterns of RAMP1, RAMP2, and RAMP3 determine how a cell or tissue will sense and respond to either extracellular CGRP or AM.Biochemical studies using heterologous overexpression of RAMPs in cultured cells have demonstrated that this general mechanism also applies to several other GPCRs of the class II family, including calcitonin receptor, parathyroid receptors 1 and 2, vasointestinal peptide/pituitary adenylate cyclase-activating peptide 1 (VIP/VPAC1) receptor, and glucagon receptor (2, 3). More recently, Bouschet et al....

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“…[25][26][27][28][29] CGRP is extensively localized in perivascular or periadventitia nerves throughout the body and exerts vasodilator effect through interaction with its receptors on endothelial and vascular smooth muscle cells via endothelium-dependent or independent mechanisms, depending on vessel type and species. [30][31][32][33][34] Localized in corpora cavernosa, CGRP also contributes to smooth muscle relaxation in the corpus cavernosum and is downregulated in the aging penis. 35,36 CGRP relaxes the smooth muscle of corpora cavernosa by hyperpolarization via K þ -channel opening and activation of adenylate cyclase, with subsequent increases in intracellular cAMP leading to erection.…”

Section: Cgrp Gene Therapy For Edmentioning

confidence: 99%

Gene and stem cell therapy for erectile dysfunction

2005

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Erectile dysfunction (ED) is defined as the inability to attain and/or maintain penile erection sufficient for satisfactory sexual performance. ED is a highly prevalent health problem with considerable impact on the quality of life of men and their partners. Although the treatment of ED with oral phosphodiesterase type V (PDE5) inhibitors is effective in a wide range of individuals, it is not efficacious in all patients. The failure of PDE5 inhibitors happens mainly in men with diabetes, non-nerve sparing radical prostatectomy, and high disease severity. Therefore, improved therapies based on a better understanding of the fundamental issues in erectile physiology and pathophysiology have recently been proposed. Here, we summarize studies on ED treatment using gene and stem cell therapies. Adenoviral-mediated intracavernosal transfer of therapeutic genes, such as endothelial nitric oxide synthase (eNOS), calcitonin gene-related peptide (CGRP), superoxide dismutase (SOD), and RhoA/Rho kinase and mesenchymal stem cell-based cell and gene therapy strategy for the treatment of age-and diabetes-related ED are the focus of this review. Penile erection, referred to as engorgement of the penis with blood, is the result of the penile arterial dilation which increases blood inflow, the relaxation of smooth muscle of the corpus cavernosum which increases blood storage, and penile venous occlusion which decreases blood outflow. The physiology of penile erection is complicated and this neurovascular event requires the functional integrity of nerves, endothelium, and smooth muscle. 1 Nitric oxide (NO), produced by both neuronal nitric oxide synthase (nNOS) in the nonadrenergic noncholinergic (NANC) nerves and endothelial nitric oxide synthase (eNOS) in the endothelium of penile arteries and cavernosal sinusoids is the principal mediator of penile erection. 2-5 NO formed in nerves or endothelial cells then diffuses to neighboring smooth muscle cells and activates soluble guanylyl cyclase. This activation results in increased cGMP formation, which mediates smooth muscle relaxation. 5 Besides NO, other molecules such as vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), substance P, and pituitary adenylate cyclase-activating polypeptide (PACAP) are also important for penile erection. 6 Causes contributing to erectile dysfunction (ED) can be broadly classified into two categories: organic and psychological. Aging, vascular diseases, neurological injuries, and diabetes mellitus are the common causes of organic ED. 7 Depressive stress is the common cause of psychological ED. 8,9 Although the treatment of ED with oral phosphodiesterase type V (PDE5) inhibitors (sildenafil, tadalafil, and vardenafil) is effective in a wide range of individuals with ED, it is not efficacious in all patients. For example, the response rate to sildenafil decreased from 72% in men 18-49 y of age to 53% in men 50 y or older. 10 The failure of sildenafil therapy happened mainly in men with diabetes, non-nerve sparing radical pr...

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The pharmacology of CGRP-responsive receptors in cultured and transfected cells

Cited by 26 publications

References 43 publications

Adrenomedullin and CGRP interact with endogenous calcitonin-receptor-like receptor in endothelial cells and induce its desensitisation by different mechanisms

Adrenomedullin and CGRP interact with endogenous calcitonin-receptor-like receptor in endothelial cells and induce its desensitisation by different mechanisms

Receptor Activity-modifying Proteins 2 and 3 Have Distinct Physiological Functions from Embryogenesis to Old Age

Gene and stem cell therapy for erectile dysfunction

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