Browsing by Subject "PKA"

Now showing 1 - 3 of 3
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    Crosstalk between G protein-coupled receptors (GPCRs) and tyrosine kinase receptor (TXR) in the heart after morphine withdrawal
    (2013-12-27) Almela Rojo, Pilar; García-Carmona, Juan-Antonio; Martínez Laorden, Elena; Laorden Carrasco, María Luisa; Milanés Maquilón, María Victoria; Farmacología
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    Different expression of protein kinase A (PKA) regulatory subunits in normal and neoplastic thyroid tissues
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Ferrero, Stefano; Vaira, Valentina; Del Gobbo, Alessandro; Vicentini, Leonardo; Bosari, Silvano; Beck-Peccoz, Paolo; Mantovan, Giovanna; Spada, Anna; Lania, Andrea G.
    The four regulatory subunits (R1A, R1B, R2A, R2B) of protein kinase A (PKA) are differentially expressed in several cancer cell lines and exert distinct roles in both cell growth and cell differentiation control. Mutations of the PRKAR1A gene have been found in patients with Carney complex and in a minority of sporadic anaplastic thyroid carcinomas. The aim of the study was to retrospectively evaluate the expression of different PKA regulatory subunits in benign and non benign human thyroid tumours and to correlate their expression with clinical phenotype. Immunohistochemistry demonstrated a significant increase in PRKAR2B expression in both differentiated and undifferentiated (anaplastic) thyroid tumors in comparison with normal thyroid tissues. Conversely, a significant increase in PRKAR1A expression was only demonstrated in undifferentiated thyroid carcinomas in comparison with normal thyroid tissue and differentiated thyroid tumors. In thyroid cancers without lymph nodal metastases PRKAR1A expression was higher in tumours of more than 2 cm in size (T2 and T3) compared to smaller ones (T1). In conclusion, our data shows that an increased PRKAR1A expression is associated with aggressive and undifferentiated thyroid tumors.
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    Manipulation of bicarbonate concentration in sperm capacitation media improves in vitro fertilisation output in porcine species
    (BioMed Central, 2019-03-11) Soriano-Úbeda, Cristina; Romero Aguirregomezcorta, Jon; Matas Parra, Carmen; Visconti, Pablo E.; García Vázquez, Francisco Alberto; Anatomía y Anatomía Patológica Comparada; Facultad de Veterinaria
    Background. The in vivo concentration of bicarbonate (HCO3−), one of the essential sperm capacitating effectors, varies greatly in the different environments sperm go through from cauda epididymis to the fertilisation site. On the contrary, porcine in vitro sperm capacitation and fertilisation media usually contains a standard concentration of 25 mmol/L, and one of the main problems presented is the unacceptable high incidence of polyspermy. This work hypothesised that by modifying the HCO3− concentration of the medium, the output of in vitro sperm capacitation and fertilisation could be increased. Results: Once exposed to the capacitation medium, the intracellular pH (pHi) of spermatozoa increased immediately even at low concentrations of HCO3−, but only extracellular concentrations of and above 15 mmol/L increased the substrates protein kinase A phosphorylation (pPKAs). Although with a significant delay, 15 mmol/L of HCO3− stimulated sperm linear motility and increased other late events in capacitation such as tyrosine phosphorylation (Tyr-P) to levels similar to those obtained with 25 mmol/L. This information allowed the establishment of a new in vitro fertilisation (IVF) system based on the optimization of HCO3− concentration to 15 mmol/L, which led to a 25.3% increment of the viable zygotes (8.6% in the standard system vs. 33.9%). Conclusions: Optimising HCO3− concentrations allows for establishing an IVF method that significantly reduced porcine polyspermy and increased the production of viable zygotes. A concentration of 15 mmol/L of HCO3− in the medium is sufficient to trigger the in vitro sperm capacitation and increase the fertilisation efficiency in porcine.