Antonio Avelino

Publications of Antonio Avelino

• Transient receptor potential vanilloid 1 mediates nerve growth factor-induced bladder hyperactivity and noxious input.

  Authors: Barbara Frias, Ana Charrua, Antonio Avelino, Martin C Michel, Francisco Cruz, Celia D Cruz

  BJU international. 04/2012;

  What's known on the subject? and What does the study add? The interaction between the TRPV1 and NGF systems has been addressed only in the context of acute somatic pain. The present study expandsWhat's known on the subject? and What does the study add? The interaction between the TRPV1 and NGF systems has been addressed only in the context of acute somatic pain. The present study expands this view and indicates that this interaction remains operative and is important as a mechanism for chronic visceral pain and dysfunction. Moreover, it further stresses the need to develop more specific and effective TRPV1 antagonists for clinical use. OBJECTIVES: •  To explore the role of transient receptor potential vanilloid 1 (TRPV1) in the excitatory effects of chronic administration of nerve growth factor (NGF) on bladder-generated sensory input and reflex activity. •  To explore new therapeutic targets for bladder dysfunction. MATERIALS AND METHODS: •  Wild-type (WT) and TRPV1 knockout (KO) mice received daily intraperitoneal injections of NGF (1 µg/10 g) or saline for a period of 4 days, during which time thermal sensitivity was evaluated daily. On the 5th day, mice were anaesthetized and cystometries were performed. The frequency, amplitude and area under the curve (AUC) of bladder reflex contractions were determined. •  c-Fos expression was evaluated on L6 spinal cord sections of WT and TRPV1 KO mice treated with saline or chronic NGF by immunohistochemistry. •  TrkA receptor staining intensity was determined in L6 spinal cord sections and respective dorsal root ganglia of WT and TRPV1 KO mice. RESULTS: •  Repeated administration of NGF induced thermal hypersensitivity in WT but not in TRPV1 KO mice. •  The frequency of bladder contractions of saline-treated WT and TRPV1 KO mice was similar, the values respectively being 0.45 ± 0.12/min and 0.46 ± 0.16/min. Treatment with NGF enhanced bladder reflex activity in WT mice to 1.23 ± 0.41/min (P < 0.05). In NGF-treated KO mice, the frequency of bladder contractions was 0.60 ± 0.05/min. Irrespective of treatment, no differences were observed in the amplitude of bladder contractions of WT and TRPV1 KO mice. The AUC was significantly increased in NGF-treated WT-mice, when compared with saline-treated WT-mice. No changes were found in AUC of saline-treated and NGF-treated TRPV1 KO mice. •  Chronic administration of NGF resulted in a significant increase of spinal c-Fos expression in WT mice (P < 0.05 vs KO animals), but not in TRPV1 KO animals. •  TrkA expression was similar in WT and TRPV1 KO mice. CONCLUSIONS: •  NGF-induced bladder overactivity and noxious input depend on the interaction of NGF with TRPV1. •  The lack of bladder overactivity in TRPV1 KO mice treated with NGF does not represent loss of TrkA expression. •  TRPV1 is essential for NGF-driven bladder dysfunction and represents a bottleneck target in bladder pathologies associated with NGF up-regulation.

• VEGF signaling mediates bladder neuroplasticity and inflammation in response to BCG.

  Authors: Marcia R Saban, Carole A Davis, Antonio Avelino, Francisco Cruz, Julie Maier, Dale E Bjorling, Thomas J Sferra, Robert E Hurst, Ricardo Saban

  BMC physiology. 11/2011; 11:16.

  This work tests the hypothesis that increased levels of vascular endothelial growth factor (VEGF) observed during bladder inflammation modulates nerve plasticity. Chronic inflammation was induced byThis work tests the hypothesis that increased levels of vascular endothelial growth factor (VEGF) observed during bladder inflammation modulates nerve plasticity. Chronic inflammation was induced by intravesical instillations of Bacillus Calmette-Guérin (BCG) into the urinary bladder and the density of nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) or pan-neuronal marker PGP9.5 was used to quantify alterations in peripheral nerve plasticity. Some mice were treated with B20, a VEGF neutralizing antibody to reduce the participation of VEGF. Additional mice were treated systemically with antibodies engineered to specifically block the binding of VEGF to NRP1 (anti-NRP1B) and NRP2 (NRP2B), or the binding of semaphorins to NRP1 (anti-NRP1 A) to diminish activity of axon guidance molecules such as neuropilins (NRPs) and semaphorins (SEMAs). To confirm that VEGF is capable of inducing inflammation and neuronal plasticity, another group of mice was instilled with recombinant VEGF165 or VEGF121 into the urinary bladder. The major finding of this work was that chronic BCG instillation resulted in inflammation and an overwhelming increase in both PGP9.5 and TRPV1 immunoreactivity, primarily in the sub-urothelium of the urinary bladder. Treatment of mice with anti-VEGF neutralizing antibody (B20) abolished the effect of BCG on inflammation and nerve density.NRP1A and NRP1B antibodies, known to reduce BCG-induced inflammation, failed to block BCG-induced increase in nerve fibers. However, the NRP2B antibody dramatically potentiated the effects of BCG in increasing PGP9.5-, TRPV1-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)-immunoreactivity (IR). Finally, instillation of VEGF121 or VEGF165 into the mouse bladder recapitulated the effects of BCG and resulted in a significant inflammation and increase in nerve density. For the first time, evidence is being presented supporting that chronic BCG instillation into the mouse bladder promotes a significant increase in peripheral nerve density that was mimicked by VEGF instillation. Effects of BCG were abolished by pre-treatment with neutralizing VEGF antibody. The present results implicate the VEGF pathway as a key modulator of inflammation and nerve plasticity, introduces a new animal model for investigation of VEGF-induced nerve plasticity, and suggests putative mechanisms underlying this phenomenon.

• Severe burn injury induces a characteristic activation of extracellular signal-regulated kinase 1/2 in spinal dorsal horn neurons.

  Authors: John P M White, Chin Wing Ko, Antonio Rei Fidalgo, Mario Cibelli, Cleoper C Paule, Peter J Anderson, Celia Cruz, Szabolcs Gomba, Klara Matesz, Gabor Veress, Antonio Avelino, Istvan Nagy

  European journal of pain (London, England). 03/2011; 15(7):683-90.

  We have studied scalding-type burn injury-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the spinal dorsal horn, which is a recognised marker for spinal nociceptiveWe have studied scalding-type burn injury-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in the spinal dorsal horn, which is a recognised marker for spinal nociceptive processing. At 5min after severe scalding injury to mouse hind-paw, a substantial number of phosphorylated ERK1/2 (pERK1/2) immunopositive neurons were found in the ipsilateral dorsal horn. At 1h post-injury, the number of pERK1/2-labelled neurons remained substantially the same. However, at 3h post-injury, a further increase in the number of labelled neurons was found on the ipsilateral side, while a remarkable increase in the number of labelled neurons on the contralateral side resulted in there being no significant difference between the extent of the labelling on both sides. By 6h post-injury, the number of labelled neurons was reduced on both sides without there being significant difference between the two sides. A similar pattern of severe scalding injury-induced activation of ERK1/2 in spinal dorsal horn neurons over the same time-course was found in mice which lacked the transient receptor potential type 1 receptor (TRPV1) except that the extent to which ERK1/2 was activated in the ipsilateral dorsal horn at 5 min post-injury was significantly greater in wild-type animals when compared to TRPV1 null animals. This difference in activation of ERK1/2 in spinal dorsal horn neurons was abolished within 1h after injury, demonstrating that TRPV1 is not essential for the maintenance of ongoing spinal nociceptive processing in inflammatory pain conditions in mouse resulting from at least certain types of severe burn injury.

• Reply to Tomasz Drewa, Zbigniew Wolski and Janusz Tyloch's Letter to the Editor re: João Silva, Rui Pinto, Tiago Carvallho, et al. Mechanisms of Prostate Atrophy after Glandular Botulinum Neurotoxin Type A Injection: An Experimental Study in the Rat. Eur Urol 2009;56:134-41.

  Authors: Francisco Cruz, João Silva, Rui Pinto, Tiago Carvallho, Ana Coelho, Antonio Avelino, Paulo Dinis

  European urology. 08/2009;

• Mechanisms of prostate atrophy after glandular botulinum neurotoxin type a injection: an experimental study in the rat.

  Authors: João Silva, Rui Pinto, Tiago Carvallho, Ana Coelho, Antonio Avelino, Paulo Dinis, Francisco Cruz

  European urology. 07/2009; 56(1):134-40.

  Previous studies in humans, dogs, and rats have shown that intraprostatic injection of botulinum neurotoxin type A (BoNTA) reduces gland size. To investigate the role of eventual impairment ofPrevious studies in humans, dogs, and rats have shown that intraprostatic injection of botulinum neurotoxin type A (BoNTA) reduces gland size. To investigate the role of eventual impairment of sympathetic, parasympathetic, and sensory nerves to gland atrophy after intraprostatic BoNTA administration. Adult male Wistar rats weighing 300-350 g were used. Animals were injected in the prostate ventral lobes with 0.2 ml of saline (n=6) or the same volume containing 10 U BoNTA (BOTOX) (n=18). Six rats treated with BoNTA further received the adrenergic agent phenylephrine (PHE, 0.05 mg/kg per day), six received the cholinergic drug bethanechol (2 mg/kg per day), and six received subcutaneous saline. Animals were sacrificed 1 wk later. Prostates were weighed, fixed, and stained for sympathetic (tyrosine hydroxylase [TH]), parasympathetic (vesicular acetylcholine [ACh] transporter [VAChT]), and sensory nerve (calcitonin gene-related peptide [CGRP]) visualisation. Terminal deoxynucleotidyl transferase biotin-dUTP nick-end labelling (TUNEL) reaction was performed to investigate apoptosis. Prostate weight in controls was 1.82+/-0.24 mg/100 g of rat weight. In BoNTA-treated rats, weight decreased to 1.28+/-0.18 mg /100 g of rat weight (p=0.002). In BoNTA plus PHE-treated rats, prostate weight was similar to controls: 1.78+/-0.27 (p=0.87). In rats treated with BoNTA plus bethanechol, weight was less than controls: 1.41+/-0.17 (p=0.01). The number of TH-positive fibres was markedly reduced after BoNTA (p<0.001). VAChT- and CGRP-positive fibres were scarce in controls, preventing further evaluation. Rats treated with BoNTA had more TUNEL-positive cells than controls (p<0.001) and rats treated with BoNTA plus PHE (p<0.001). There were no differences between the BoNTA and BoNTA plus bethanechol groups (p=0.81). Although showing atrophy after BoNTA injection, rat prostates do not develop benign prostatic hyperplasia (BPH). Thus, present findings should be used cautiously to explain prostate atrophy seen in men with BPH treated with BoNTA. Prostate atrophy induced by BoNTA in the rat may be the result of sympathetic nerve impairment and decreased adrenergic stimulation of the gland. Data indirectly suggest that sympathetic drive plays a role in prostate-size regulation.

• N-acyldopamines control striatal input terminals via novel ligand-gated cation channels.

  Authors: Samira G Ferreira, Tonia Lomaglio, Antonio Avelino, Francisco Cruz, Catarina R Oliveira, Rodrigo A Cunha, Attila Köfalvi

  Neuropharmacology. 01/2009;

  Endogenous analogues of capsaicin, N-acyldopamines, were previously identified from striatal extracts, but the putative presynaptic role of their receptor, the TRPV(1)R (formerly: vanilloid orEndogenous analogues of capsaicin, N-acyldopamines, were previously identified from striatal extracts, but the putative presynaptic role of their receptor, the TRPV(1)R (formerly: vanilloid or capsaicin receptor) in the caudate-putamen is unclear. We found that the endogenous TRPV(1)R agonists, N-arachidonoyldopamine (NADA) and oleoyldopamine (OLDA) with EC(50) values in the nanomolar range, as well as the synthetic TRPV(1)R activator 2-aminoethoxydiphenylborane (2APB), and palmytoyldopamine (PALDA, another endogenous N-acyldopamine inactive at the TRPV(1)R), but not capsaicin or other endogenous and synthetic cannabinoids, triggered a rapid Ca(2+) entry with the concomitant stimulation of glutamate and dopamine release. These effects persisted in the TRPV(1)R null-mutant mice, and were insensitive to antagonists of common ionotropic receptors, to several TRPV(1)R antagonists and to the absence of K(+). Furthermore, these N-acyldopamine receptors in glutamatergic and dopaminergic terminals are different based on their different sensitivity to anandamide, capsazepine and Gd(3+) at nanomolar concentrations. Altogether, novel ion channels instead of the TRPV(1)R mediate the presynaptic action of N-acyldopamines in the striatum of adult rodents.

• Neurochemical characterization of insulin receptor-expressing primary sensory neurons in wild-type and vanilloid type 1 transient receptor potential receptor knockout mice.

  Authors: Djalil Baiou, Peter Santha, Antonio Avelino, Ana Charrua, Timea Bacskai, Klara Matesz, Francisco Cruz, Istvan Nagy

  The Journal of comparative neurology. 08/2007; 503(2):334-47.

  The insulin receptor (IR) is expressed by a subpopulation of primary sensory neurons (PSN), including a proportion of cells expressing the nociceptive transducer vanilloid type 1 transient receptorThe insulin receptor (IR) is expressed by a subpopulation of primary sensory neurons (PSN), including a proportion of cells expressing the nociceptive transducer vanilloid type 1 transient receptor potential receptor (TRPV1). Recent data suggest functional links between the IR and other receptors, including TRPV1, which could be involved in the development of PSN malfunctions in pathological insulin secretion. Here we used combined immunohistochemical labelling on sections from L4-5 dorsal root ganglia of wild-type (WT) and TRPV1 knockout (KO) mice to examine the neurochemical properties of IR-expressing PSN and the possible effect of deletion of TRPV1 on those characteristics. We found that antibodies raised against the high-molecular-weight neurofilament (NF-200) and the neurofilament protein peripherin distinguished between small and large neurons. We also found that the IR was expressed predominantly by the small peripherin-immunopositive cells both in the WT and in the KO animals. IR expression, however, did not show any preference between the major subpopulations of the small cells, the calcitonin gene-related peptide (CGRP)-expressing and Bandeiraea simplicifolia isolectin B4 (IB4)-binding neurons, either in the WT or in the KO mice. Nevertheless, a significant proportion of the IR-expressing cells also expressed TRPV1. Comparison of the staining pattern of these markers showed no difference between WT and KO animals. These findings indicate that the majority of the IR-expressing PSN are small neurons, which are considered as nociceptive cells. Furthermore, these data show that deletion of the TRPV1 gene does not induce any additional changes in neurochemical phenotype of nociceptive PSN.

• Anandamide-evoked activation of vanilloid receptor 1 contributes to the development of bladder hyperreflexia and nociceptive transmission to spinal dorsal horn neurons in cystitis.

  Authors: Paulo Dinis, Ana Charrua, Antonio Avelino, Mohammed Yaqoob, Stuart Bevan, Istvan Nagy, Francisco Cruz

  The Journal of neuroscience : the official journal of the Society for Neuroscience. 01/2005; 24(50):11253-63.

  The role of anandamide in the development of inflammatory hyperalgesia and visceral hyperreflexia was studied in the rat urinary bladder. Animals were given intraperitoneal cyclophosphamideThe role of anandamide in the development of inflammatory hyperalgesia and visceral hyperreflexia was studied in the rat urinary bladder. Animals were given intraperitoneal cyclophosphamide injection, which evokes painful hemorrhagic cystitis accompanied by increased bladder reflex activity. The vanilloid receptor 1 [transient receptor potential vanilloid 1 (TRPV1)] antagonist capsazepine, applied onto the serosal surface of bladders, significantly reduced the hyperreflexia. Mass spectrometric analysis revealed that cyclophosphamide injection significantly and persistently increased the anandamide content of bladder tissues. The increase in the anandamide content paralleled the development of reflex hyperactivity. Anandamide (1-100 microm), applied onto the serosal surface of naive bladders, increased the reflex activity in a concentration-dependent manner. Repeated anandamide applications did not produce desensitization of the response. The anandamide-evoked effect was blocked by capsazepine or by instillation of resiniferatoxin, the ultrapotent TRPV1 agonist, into the bladders 24 hr before the anandamide challenge. The cannabinoid 1 receptor antagonist SR141716A [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide] significantly increased the potency of anandamide in enhancing bladder reflex activity in naive but not in cyclophosphamide-injected animals. Application of the fatty acid amide hydrolyze inhibitor palmitoylisopropylamine onto the serosal surface of bladders also increased the reflex activity both in naive and cyclophosphamide-injected rats. This latter effect in naive animals was blocked by capsazepine and by resiniferatoxin pretreatment. Finally, intravesical instillation of anandamide (50 microm) increased c-fos expression in the spinal cord, which was reduced by capsazepine or by resiniferatoxin pretreatment. These results suggest that anandamide, through activating TRPV1, contributes to the development of hyperreflexia and hyperalgesia during cystitis.