Gastroprotective Effects of Oral Glycosaminoglycans with Sodium Alginate in an Indomethacin-Induced Gastric Injury Model in Rats

The gastrointestinal (GI) mucosal barrier is often exposed to inflammatory and erosive insults, resulting in gastric lesions. Glycosaminoglycans (GAGs), such as hyaluronic acid (HA), chondroitin sulfate (CS), and N-acetylglucosamine (NAG) have shown potential beneficial effects as GI protectants. This study aimed to evaluate the gastroprotective effects of oral GAGs in rats with indomethacin-induced GI lesions. Forty-five Sprague-Dawley rats (8-9 weeks-old, 228 ± 7 g) were included in the study, divided into five study groups, and given, administered orally, either sucralfate (positive control group; PC), NAG (G group), sodium alginate plus HA and CS (AHC group), sodium alginate plus HA, CS, and NAG (AHCG group), or no treatment (negative control group; NC). Animals were administered 12.5 mg/kg indomethacin orally 15 min after receiving the assigned treatment. After 4 h, stomach samples were obtained and used to perform a macroscopic evaluation of gastric lesions and to allow histological assessment of the gastric wall (via H/E staining) and mucous (via PAS staining). The AHCG group showed significant gastroprotective improvements compared to the NC group, and a similar efficacy to the PC group. This combination of sodium alginate with GAGs might, therefore, become a safe and effective alternative to prescription drugs for gastric lesions, such as sucralfate, and have potential usefulness in companion animals

Pharmacodynamics of TRPV1 Agonists in a Bioassay Using Human PC-3 Cells

Altres ajuts: La Fundació Marató de TV3Purpose. TRPV1 is a multimodal channel mainly expressed in sensory neurons. We aimed to explore the pharmacodynamics of the TRPV1 agonists, capsaicin, natural capsaicinoids, and piperine in an in vitro bioassay using human PC-3 cells and to examine desensitization and the effect of the specific antagonist SB366791. Methods. PC-3 cells expressing TRPV1 were incubated with Fluo-4. Fluorescence emission changes following exposition to agonists with and without preincubation with antagonists were assessed and referred to maximal fluorescence following the addition of ionomycin. Concentration-response curves were fitted to the Hill equation. Results. Capsaicin and piperine had similar pharmacodynamics (E 204.8 ± 184.3% piperine versus 176.6 ± 35.83% capsaicin, P = 0.8814, Hill coefficient 0.70 ± 0.50 piperine versus 1.59 ± 0.86 capsaicin, P = 0.3752). In contrast, capsaicinoids had lower E (40.99 ± 6.14% capsaicinoids versus 176.6 ± 35.83% capsaicin, P < 0.001). All the TRPV1 agonists showed significant desensitization after the second exposition and their effects were strongly inhibited by SB366791. Conclusion. TRPV1 receptor is successfully stimulated by capsaicin, piperine, and natural capsaicinoids. These agonists present desensitization and their effect is significantly reduced by a TRPV1-specific antagonist. In addition, PC-3 cell bioassays proved useful in the study of TRPV1 pharmacodynamics

First translational consensus on terminology and definitions of colonic motility in animals and humans studied by manometric and other techniques

Alterations in colonic motility are implicated in the pathophysiology of bowel disorders, but high-resolution manometry of human colonic motor function has revealed that our knowledge of normal motor patterns is limited. Furthermore, various terminologies and definitions have been used to describe colonic motor patterns in children, adults and animals. An example is the distinction between the high-amplitude propagating contractions in humans and giant contractions in animals. Harmonized terminology and definitions are required that are applicable to the study of colonic motility performed by basic scientists and clinicians, as well as adult and paediatric gastroenterologists. As clinical studies increasingly require adequate animal models to develop and test new therapies, there is a need for rational use of terminology to describe those motor patterns that are equivalent between animals and humans. This Consensus Statement provides the first harmonized interpretation of commonly used terminology to describe colonic motor function and delineates possible similarities between motor patterns observed in animal models and humans in vitro (ex vivo) and in vivo. The consolidated terminology can be an impetus for new research that will considerably improve our understanding of colonic motor function and will facilitate the development and testing of new therapies for colonic motility disorders. This Consensus Statement provides a conceptual and methodological framework to expand research on colonic motility in experimental animals and humans. The work is intended to facilitate the development of new drugs for common colonic motility disorders and of appropriate diagnostic and therapeutic algorithms for the management of paediatric and adult patients

Carta de Marcelo Jiménez Farrerons al Rector de la UB sol·licitant la revisió de les decisions en la convocatòria de plaça de Professor Titular de Fisiologia Animal

Relacionat amb 22-022, 22-023, 22-024, 22-026, 22-027 i 22-028

Detection of Abnormal Cardiac Response Patterns in Cardiac Tissue Using Deep Learning

This study reports a method for the detection of mechanical signaling anomalies in cardiac tissue through the use of deep learning and the design of two anomaly detectors. In contrast to anomaly classifiers, anomaly detectors allow accurate identification of the time position of the anomaly. The first detector used a recurrent neural network (RNN) of long short-term memory (LSTM) type, while the second used an autoencoder. Mechanical contraction data present several challanges, including high presence of noise due to the biological variability in the contraction response, noise introduced by the data acquisition chain and a wide variety of anomalies. Therefore, we present a robust deep-learning-based anomaly detection framework that addresses these main issues, which are difficult to address with standard unsupervised learning techniques. For the time series recording, an experimental model was designed in which signals of cardiac mechanical contraction (right and left atria) of a CD-1 mouse could be acquired in an automatic organ bath, reproducing the physiological conditions. In order to train the anomaly detection models and validate their performance, a database of synthetic signals was designed (n = 800 signals), including a wide range of anomalous events observed in the experimental recordings. The detector based on the LSTM neural network was the most accurate. The performance of this detector was assessed by means of experimental mechanical recordings of cardiac tissue of the right and left atria

Pharmacodynamics of TRPV1 Agonists in a Bioassay Using Human PC-3 Cells

Altres ajuts: La Fundació Marató de TV3Purpose. TRPV1 is a multimodal channel mainly expressed in sensory neurons. We aimed to explore the pharmacodynamics of the TRPV1 agonists, capsaicin, natural capsaicinoids, and piperine in an in vitro bioassay using human PC-3 cells and to examine desensitization and the effect of the specific antagonist SB366791. Methods. PC-3 cells expressing TRPV1 were incubated with Fluo-4. Fluorescence emission changes following exposition to agonists with and without preincubation with antagonists were assessed and referred to maximal fluorescence following the addition of ionomycin. Concentration-response curves were fitted to the Hill equation. Results. Capsaicin and piperine had similar pharmacodynamics (E 204.8 ± 184.3% piperine versus 176.6 ± 35.83% capsaicin, P = 0.8814, Hill coefficient 0.70 ± 0.50 piperine versus 1.59 ± 0.86 capsaicin, P = 0.3752). In contrast, capsaicinoids had lower E (40.99 ± 6.14% capsaicinoids versus 176.6 ± 35.83% capsaicin, P < 0.001). All the TRPV1 agonists showed significant desensitization after the second exposition and their effects were strongly inhibited by SB366791. Conclusion. TRPV1 receptor is successfully stimulated by capsaicin, piperine, and natural capsaicinoids. These agonists present desensitization and their effect is significantly reduced by a TRPV1-specific antagonist. In addition, PC-3 cell bioassays proved useful in the study of TRPV1 pharmacodynamics

Pharmacological targets mediating colonic smooth muscle relaxation

Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2017-2018Els principals neurotransmissors excitatoris al còlon són l'Acetilcolina i les taquiquinines, mentre que l'adenosina trifosfat (ATP) (o purina relacionada) i l'òxid nitric (NO) són els principals neurotransmissors inhibitoris que causen hiperpolarització del múscul llis i la corresponent relaxació. Recentment, el sulfur d'hidrogen (H2S) ha estat proposat com un mediador inhibitori. A més, les vies relacionades amb la prostaglandina E2 (PGE2) han estat relacionades amb el control de la contractilitat gastrointestinal. El següents mecanismes d'acció de diferents mediadors "espasmolítics" han estat investigats: activació dels receptors acoblats a proteïnes G (GPCR) inhibitoris P2Y1 i EP2/EP4, inhibició dels GPCR excitatoris muscarinic i taquiquinèrgic i blocatge dels canals de calci voltage depenents (VDCC) de tipus L i T. En el còlon humà i de rata, la relaxació no nitrèrgica fou inhibida per MRS2500 i apamina, suggerint que la purina endògena activa receptors P2Y1 i canals de potassi activats per calci de baixa conductància. Diferents agonistes purinèrgics (ATP, ADP, β-NAD i ADP-ribosa) van ser capaços d'inhibir la contractilitat però no van ser antagonitzats per MRS2500 ni apamina. En canvi, α,β-meATP, anàleg estable de l'ATP considerat un agonista P2X, va imitar perfectament el perfil farmacològic del neurotransmissor purinèrgic en ambdues espècies. L'activació dels receptors inhibitoris EP2/EP4 va produir relaxació de la musculatura llisa circular del còlon de ratolí. En ratolins wild type (WT), PGE2 i butaprost van causar relaxació i hiperpolarització del múscul llis. La combinació dels antagonistes selectius dels receptors EP2 (PF-04418948) i EP4 (L-161,982) fou necessària per blocar els efectes de la PGE2, suggerint activació d'ambdós receptors. Els efectes inhibitoris de butaprost van ser totalment blocats per PF-04418948. En ratolins knockout pel receptor EP2 no es va observar cap efecte després de l'addició exògena de butaprost mentre que els efectes de la PGE2 van ser completament antagonitzats per L-161,982. En animals WT, els antagonistes dels receptors EP2 i EP4 van causar despolarització del múscul llis així com un increment en l'activitat mecànica, suggerint una producció constitutiva de prostaglandines activant ambdós receptors. En el còlon humà, la combinació dels inhibidors dels enzims de síntesi de H2S cistationina β-sintasa i la cistationina γ-liasa van despolaritzar el múscul llis i van produir un increment de to. NaHS, un donador de H2S, va inhibir les contraccions de forma concentració-depenent. Aquest efecte fou reduït per l'inhibidor de guanilat ciclasa ODQ i per l'inhibidor de la síntesi de NO L-NNA. NaHS va blocar de manera reversible les contraccions colinèrgiques i taquiquinèrgiques neuralment mediades així com l'increment d'activitat mecànica induïda per carbachol i neurokinina A (NKA). El H2S podria ser un gasomediador endogen capaç de regular la contractilitat de la musculatura llisa del còlon humà i els seus efectes inhibitoris podrien ser deguts tant a una possible sinèrgia amb NO com a la interacció amb les vies colinèrgiques i taquiquinèrgiques. Hem investigat també les propietats farmacològiques del fàrmac espasmolític bromur d'otiloni (OB). Els increments de calci citoplasmàtic i les contraccions mediades per canals de tipus L sensibles a nifedipina van ser inhibits per OB. En presència de nifedipina, OB va inhibir les respostes muscaríniques sensibles a atropina induïdes per carbacol i estímul elèctric de camp. A més, OB va blocar els increments de calci citoplasmàtic induïts per NKA i CaCl2. Aquests resultats demostren que el OB inhibeix els VDCC de tipus L i T així com les respostes muscaríniques i taquiquinèrgiques, efectes que actuant conjuntament expliquen les seves propietats farmacològiques. Els resultats presentats en aquest treball suggereixen que les vies inhibitòries relacionades amb els GPCR P2Y1 i EP2/EP4 i H2S podrien ser considerades com potencials dianes farmacològiques pel tractament de l'espasticitat associada a desordres motors colònics.The principal excitatory neurotransmitters in the colon are acetylcholine and tachykinins, while adenosine triphosphate (ATP) (or related purine) and nitric oxide (NO) are the main inhibitory neurotransmitters causing smooth muscle hyperpolarization and the corresponding relaxation. Recently, hydrogen sulphide (H2S) has been proposed as an inhibitory mediator. Moreover, prostaglandin E2 (PGE2) related pathways might be involved in the control of gastrointestinal contractility. Relaxation of colonic smooth muscle can be reached either by activation of the inhibitory pathways or by blockade of the excitatory ones. The mechanisms of action of several "spasmolytic" mediators capable for inhibiting smooth muscle contractility have been investigated: activation of inhibitory P2Y1 and EP2/EP4 G protein-coupled receptors (GPCR), inhibition of the excitatory muscarinic and tachykinergic GPCR and blockade of L-type and T-type voltage dependent calcium channels (VDCC). Both in the rat and human colon, the non-nitrergic relaxation was inhibited either by MRS2500 or apamin, suggesting that the endogenous purine is activating P2Y1 receptors and leading to the opening of small conductance calcium-activated potassium channels. Several purinergic agonists tested (ATP, ADP, β-NAD and ADP-ribose) inhibited spontaneous contractions but were not antagonized neither by MRS2500 nor apamin. On the contrary, α,β- meATP, a stable analogue of ATP widely considered as a P2X agonist, perfectly mimicked the pharmacological profile of the purinergic transmitter in both species. Activation of EP2/EP4 inhibitory GPCR led to relaxation of murine circular colonic smooth muscle. In wild type (WT) animals, PGE2 and butaprost concentration-dependently inhibited spontaneous contractions and hyperpolarized smooth muscle cells. Combination of both EP2 (PF-04418948) and EP4 receptor selective antagonists (L-161,982) was needed to block PGE2 effects, suggesting activation of both EP2 and EP4 receptors. Butaprost inhibitory responses were totally abolished by PF-04418948. In EP2-knockout mice, no effects were observed after butaprost exogenous addition whereas PGE2 induced relaxation and hyperpolarization was fully antagonized by L- 161,982. In WT animals, EP2 and EP4 receptor antagonists caused smooth muscle depolarization and increased spontaneous mechanical activity, suggesting a constitutive release of prostaglandins acting on such receptors. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are two enzymes responsible for H2S production. In the human colon, combination of the CSE inhibitor D,L-propargylglycine and the CBS inhibitor Aminooxyacetic acid depolarized the smooth muscle and elicited a transient tone increase. The H2S donor NaHS concentration-dependently inhibited spontaneous contractions in the presence of tetrodotoxin. This effect was partially reduced by the guanylyl cyclase inhibitor ODQ and by the NO synthases blocker L-NNA. NaHS reversibly blocked neural mediated cholinergic and tachykinergic contractions and also concentration dependently reduced the increase in spontaneous mechanical activity induced by carbachol and neurokinin A (NKA). H2S might be an endogenous gasomediator regulating human colonic contractility and its inhibitory effect could be due to a possible synergistic effect with NO as well as by an interaction with the cholinergic and tachykinergic pathways. The pharmacological properties of the spasmolytic drug otilonium bromide (OB) have also been investigated. OB concentration-dependently inhibited nifedipine sensitive calcium transients induced by KCl and BayK8644 and also CaCl2 induced contractions in colonic strips. In the presence of nifedipine, OB inhibited atropinesensitive carbachol-induced and electrical field stimulation-induced muscarinic responses. Moreover, OB inhibited NKA and CaCl2 induced calcium transients. These results demonstrate that OB causes inhibition of L-/T-type VDCC, muscarinic and tachykininergic responses that acting together might explain the pharmacological properties of the compound. The results presented in the present work suggest that the inhibitory pathways related to P2Y1 and EP2/EP4 GPCR and H2S should be considered as potential pharmacological targets that produce smooth muscle relaxation and therefore could be useful tools to treat spasticity in colonic motor disorders. Further investigation is needed in order to find out their real therapeutic potential

First translational consensus on terminology and definitions of colonic motility in animals and humans studied by manometric and other techniques

Alterations in colonic motility are implicated in the pathophysiology of bowel disorders, but high-resolution manometry of human colonic motor function has revealed that our knowledge of normal motor patterns is limited. Furthermore, various terminologies and definitions have been used to describe colonic motor patterns in children, adults and animals. An example is the distinction between the high-amplitude propagating contractions in humans and giant contractions in animals. Harmonized terminology and definitions are required that are applicable to the study of colonic motility performed by basic scientists and clinicians, as well as adult and paediatric gastroenterologists. As clinical studies increasingly require adequate animal models to develop and test new therapies, there is a need for rational use of terminology to describe those motor patterns that are equivalent between animals and humans. This Consensus Statement provides the first harmonized interpretation of commonly used terminology to describe colonic motor function and delineates possible similarities between motor patterns observed in animal models and humans in vitro (ex vivo) and in vivo. The consolidated terminology can be an impetus for new research that will considerably improve our understanding of colonic motor function and will facilitate the development and testing of new therapies for colonic motility disorders. This Consensus Statement provides a conceptual and methodological framework to expand research on colonic motility in experimental animals and humans. The work is intended to facilitate the development of new drugs for common colonic motility disorders and of appropriate diagnostic and therapeutic algorithms for the management of paediatric and adult patients