Estrous cycle and ovariectomy-induced changes in visceral pain are microbiota-dependent

Visceral hypersensitivity (VH) is a hallmark of many functional gastrointestinal disorders including irritable bowel syndrome and is categorized by a dull, diffuse sensation of abdominal pain. Recently, the gut microbiota has been implicated in VH in male mice, but the effects in females have yet to be explored fully. To this end, we now show that somewhat surprisingly, female germ-free mice have similar visceral pain responses to colorectal distension (CRD) as their conventional controls. However, we show that although sensitivity to CRD is estrous cycle stage-dependent in conventional mice, it is not in germ-free mice. Further, ovariectomy (OVX) induced VH in conventional but not germ-free mice, and induced weight gain regardless of microbiota status. Finally, we show that estrogen-replacement ameliorated OVX-induced VH. Taken together, this study provides evidence for a major role of female sex hormones and the gut microbiota in sensation of visceral pain in females.Funding: This work was funded by Science Foundation Ireland through the Irish Government’s National Development Plan in the form of a center grant (APC Microbiome Institute Grant Number SFI/12/RC/2273_P2)

BAMBI (bone morphogenetic protein and activin membrane-bound inhibitor) reveals the involvement of the transforming growth factor-beta family in pain modulation

Transforming growth factors- (TGF- s) signal through type I and type II serine–threonine kinase receptor complexes. During ligand binding, type II receptors recruit and phosphorylate type I receptors, triggering downstream signaling. BAMBI [bone morphogenetic protein (BMP) and activin membrane-bound inhibitor] is a transmembrane pseudoreceptor structurally similar to type I receptors but lacks the intracellular kinase domain. BAMBI modulates negatively pan-TGF- family signaling; therefore, it can be used as an instrument for unraveling the roles of these cytokines in the adult CNS. BAMBI is expressed in regions of the CNS involved in pain transmission and modulation. The lack of BAMBI in mutant mice resulted in increased levels of TGF- signaling activity, which was associated with attenuation of acute pain behaviors, regardless of the modality of the stimuli (thermal, mechanical, chemical/inflammatory). The nociceptive hyposensitivity exhibited by BAMBI / mice was reversed by the opioid antagonist naloxone. Moreover, in a model of chronic neuropathic pain, the allodynic responses of BAMBI / mice also appeared attenuated through a mechanism involving -opioid receptor signaling. BasalmRNAand protein levels of precursor proteins of the endogenous opioid peptides proopiomelanocortin (POMC) and proenkephalin (PENK) appeared increased in the spinal cords of BAMBI / . Transcript levels of TGF- s and their intracellular effectors correlated directly with genes encoding opioid peptides, whereas BAMBI correlated inversely. Furthermore, incubation of spinal cord explants with activin A or BMP-7 increased POMC and/or PENK mRNA levels. Our findings identify TGF- family members as modulators of acute and chronic pain perception through the transcriptional regulation of genes encoding the endogenous opioids

Identification of Epigenetic Interactions between MicroRNA-30c-5p and DNA Methyltransferases in Neuropathic Pain

Neuropathic pain is a prevalent and severe chronic syndrome, often refractory to treatment, whose development and maintenance may involve epigenetic mechanisms. We previously demonstrated a causal relationship between miR-30c-5p upregulation in nociception-related neural structures and neuropathic pain in rats subjected to sciatic nerve injury. Furthermore, a short course of an miR-30c-5p inhibitor administered into the cisterna magna exerts long-lasting antiallodynic effects via a TGF-?1-mediated mechanism. Herein, we show that miR-30c-5p inhibition leads to global DNA hyper-methylation of neurons in the lumbar dorsal root ganglia and spinal dorsal horn in rats subjected to sciatic nerve injury. Specifically, the inhibition of miR-30-5p significantly increased the expression of the novo DNA methyltransferases DNMT3a and DNMT3b in those structures. Furthermore, we identified the mechanism and found that miR-30c-5p targets the mRNAs of DNMT3a and DNMT3b. Quantitative methylation analysis revealed that the promoter region of the antiallodynic cytokine TGF-?1 was hypomethylated in the spinal dorsal horn of nerve-injured rats treated with the miR-30c-5p inhibitor, while the promoter of Nfyc, the host gene of miR-30c-5p, was hypermethylated. These results are consistent with long-term protection against neuropathic pain development after nerve injury. Altogether, our results highlight the key role of miR-30c-5p in the epigenetic mechanisms' underlying neuropathic pain and provide the basis for miR-30c-5p as a therapeutic target.Funding: This work was supported by: Grant SAF2016-77732-R funded by MCIN/AEI/10.13039/ 501100011033 and by “ERDF A way of making Europe”; Grant PID2019-104398RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and Instituto de Investigación Sanitaria Valdecilla (IDIVAL) (NVAL17/23). R.F. was the recipient of a pre-doctoral fellowship of the Foundation Tatiana Pérez de Guzmán el Bueno. Acknowledgments: We acknowledge the excellent technical assistance of Nieves García Iglesias

Comparativa entre las prácticas de farmacología de la uc clásicas y las adaptadas a las tecnologías virtuales. Opinión del alumnado

En la Facultad de Medicina de la Universidad de Cantabria hemos incorporado metodología guiada por ordenadores a las clases prácticas de laboratorio. Los alumnos de los cursos académicos (1999-2000 y 2010/2011) han evaluado la utilidad de estas clases prácticas para la comprensión global de la asignatura, mediante la realización de un cuestionario voluntario y anónimo. En 1999-2000 los estudiantes trabajaban con animales de laboratorio en las prácticas, mientras que en el año académico 2010/2011 se sustituyeron por programas informatizados de aprendizaje. Con este estudio intentamos evaluar desde la perspectiva del alumno si los programas virtuales de ordenador son una buena alternativa a la experimentación animal como método de enseñanza en las clases prácticas de Farmacología en términos de la satisfacción del estudiante

Mecanismos implicados en el efecto protector de citoquinas pertenecientes a la familia Factores de Crecimiento Transformante-beta frente al desarrollo de dolor neuropático: XXXII Congreso Nacional de la SEF: premio Almirall

RB-101 fue generosamente facilitado por el Dr. Bernard Roques. El trabajo está financiado por: Sociedad Española de Farmacología y Laboratorios Almirall; Instituto de Salud Carlos III (RTICS: RD06/001/1016); Ministerio de Ciencia e Innovación (SAF2010-16894); Fundació La Marató de TV3 (Grant 072131)

TGF-β and opioid receptor signaling crosstalk results in improvement of endogenous and exogenous opioid analgesia under pathological pain conditions

Transforming growth factor-β1 (TGF-β1) protects against neuroinflammatory events underlying neuropathic pain. TGF-β signaling enhancement is a phenotypic characteristic of mice lacking the TGF-β pseudoreceptor BAMBI (BMP and activin membrane-bound inhibitor), which leads to an increased synaptic release of opioid peptides and to a naloxone-reversible hypoalgesic/antiallodynic phenotype. Herein, we investigated the following: (1) the effects of BAMBI deficiency on opioid receptor expression, functional efficacy, and analgesic responses to endogenous and exogenous opioids; and (2) the involvement of the opioid system in the antiallodynic effect of TGF-β1. BAMBI-KO mice were subjected to neuropathic pain by sciatic nerve crash injury (SNI). Gene (PCR) and protein (Western blot) expressions of μ- and δ-opioid receptors were determined in the spinal cord. The inhibitory effects of agonists on the adenylyl cyclase pathway were investigated. Two weeks after SNI, wild-type mice developed mechanical allodynia and the functionality of μ-opioid receptors was reduced. By this time, BAMBI-KO mice were protected against allodynia and exhibited increased expression and function of opioid receptors. Four weeks after SNI, when mice of both genotypes had developed neuropathic pain, the analgesic responses induced by morphine and RB101 (an inhibitor of enkephalin-degrading enzymes, which increases the synaptic levels of enkephalins) were enhanced in BAMBI-KO mice. Similar results were obtained in the formalin-induced chemical-inflammatory pain model. Subcutaneous TGF-β1 infusion prevented pain development after SNI. The antiallodynic effect of TGF-β1 was naloxone-sensitive. In conclusion, modulation of the endogenous opioid system by TGF-β signaling improves the analgesic effectiveness of exogenous and endogenous opioids under pathological pain conditions.This work was supported by Ministerio de Ciencia e Innovacio´n Grant SAF2010-16894, Fundacio´ La Marato´ de TV3 Grant 072131, Instituto de Salud Carlos III Grant RTICS:RD06/001/1016, and Sociedad Espan˜ola de Farmacología and Laboratorios Almirall-Prodesfarm

BAMBI (bone morphogenetic protein and activin membrane-bound inhibitor) reveals the involvement of the transforming growth factor-ß family in pain modulation

Transforming growth factors-beta (TGF-betas) signal through type I and type II serine-threonine kinase receptor complexes. During ligand binding, type II receptors recruit and phosphorylate type I receptors, triggering downstream signaling. BAMBI [bone morphogenetic protein (BMP) and activin membrane-bound inhibitor] is a transmembrane pseudoreceptor structurally similar to type I receptors but lacks the intracellular kinase domain. BAMBI modulates negatively pan-TGF-beta family signaling; therefore, it can be used as an instrument for unraveling the roles of these cytokines in the adult CNS. BAMBI is expressed in regions of the CNS involved in pain transmission and modulation. The lack of BAMBI in mutant mice resulted in increased levels of TGF-beta signaling activity, which was associated with attenuation of acute pain behaviors, regardless of the modality of the stimuli (thermal, mechanical, chemical/inflammatory). The nociceptive hyposensitivity exhibited by BAMBI(-/-) mice was reversed by the opioid antagonist naloxone. Moreover, in a model of chronic neuropathic pain, the allodynic responses of BAMBI(-/-) mice also appeared attenuated through a mechanism involving delta-opioid receptor signaling. Basal mRNA and protein levels of precursor proteins of the endogenous opioid peptides proopiomelanocortin (POMC) and proenkephalin (PENK) appeared increased in the spinal cords of BAMBI(-/-). Transcript levels of TGF-betas and their intracellular effectors correlated directly with genes encoding opioid peptides, whereas BAMBI correlated inversely. Furthermore, incubation of spinal cord explants with activin A or BMP-7 increased POMC and/or PENK mRNA levels. Our findings identify TGF-beta family members as modulators of acute and chronic pain perception through the transcriptional regulation of genes encoding the endogenous opioids.This work was supported by Ministerio de Ciencia e Innovación Grant SAF2007-65451, Instituto de Salud Carlos III Grant RD06/0001/1016, and Fundación La Marató de TV3 Grant 072131 (M.A.H.), by Instituto de Salud Carlos III Grant FIS-PI 060240, by Ministerio de Ciencia e Innovación Grant SAF2005-00811 (R.M.), and by the National Institutes of Health and the G. Harold and Leila Y. Mathers Charitable Foundation (J.C.I.-B.). We thank N. García, S. Pérez, M. F. Calderón, and C. Badía for their technical assistance