cAMP-dependent chloride secretion mediates tubule enlargement and cyst formation by cultured mammalian collecting duct cells.

Polycystic kidney diseases result from disruption of the genetically defined program that controls the size and geometry of renal tubules. Cysts which frequently arise from the collecting duct (CD) result from cell proliferation and fluid secretion. From mCCD(cl1) cells, a differentiated mouse CD cell line, we isolated a clonal subpopulation (mCCD-N21) that retains morphogenetic capacity. When grown in three-dimensional gels, mCCD-N21 cells formed highly organized tubular structures consisting of a palisade of polarized epithelial cells surrounding a cylindrical lumen. Subsequent addition of cAMP-elevating agents (forskolin or cholera toxin) or of membrane-permeable cAMP analogs (CPT-cAMP) resulted in rapid and progressive dilatation of existing tubules, leading to the formation of cystlike structures. When grown on filters, mCCD-N21 cells exhibited a high transepithelial resistance as well as aldosterone- and/or vasopressin-induced amiloride-sensitive and -insensitive current. The latter was in part inhibited by Na(+)-K(+)-2Cl(-) cotransporter (bumetanide) and chloride channel (NPPB) inhibitors. Real-time PCR analysis confirmed the expression of NKCC1, the ubiquitous Na(+)-K(+)-2Cl(-) cotransporter and cystic fibrosis transmembrane regulator (CFTR) in mCCD-N21 cells. Tubule enlargement and cyst formation were prevented by inhibitors of Na(+)-K(+)-2Cl(-) cotransporters (bumetanide or ethacrynic acid) or CFTR (NPPB or CFTR inhibitor-172). These results further support the notion that cAMP signaling plays a key role in renal cyst formation, at least in part by promoting chloride-driven fluid secretion. This new in vitro model of tubule-to-cyst conversion affords a unique opportunity for investigating the molecular mechanisms that govern the architecture of epithelial tubes, as well as for dissecting the pathophysiological processes underlying cystic kidney diseases.

Més enllà de les filferrades: la resiliència i els infants de l'èxode republicà al camp de Rivesaltes

Treball de recerca realitzat per alumnes d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2010. La recerca duta a terme pretén donar veu a persones que, essent infants, van patir el tancament en els camps de concentració del sud de França, i especialment el de Rivesaltes, a la fi de la Guerra Civil espanyola. S'intenta esbrinar si la situació traumàtica viscuda per aquests infants els hi ha permès, posteriorment, portar una vida satisfactòria, si han estat capaços de superar el record dur del seu tancament. L’objectiu és posar de manifest que els nens són les principals víctimes dels conflictes d'abans i d'ara i aquests conflictes poden deixar seqüeles que els dificultin dur una vida plena.

Jornada de Camp de l'Arròs 2013

L’arròs és el conreu amb més rellevància mediambiental, econòmica i social en el nostre territori. Aquesta jornada de camp ens ofereix l’oportunitat d’estar al dia dels avanços que es van introduint, a més de ser un lloc de trobada i intercanvi d’experiències entre tots els assistents. Enguany, com a novetat, presentem el programa Origens de Kellogg’s i els assajos d’estrès hídric de la Comunitat de Regants de la Dreta. A més, la vitrina tecnològica s’està consolidant com a eina per a difondre noves tecnologies. La visita als diferents assajos es durà a terme simultàniament, però amb grups reduïts. La jornada va adreçada a tots aquells arrossers i tècnics vinculats al món de l’arròs.

Mémoire sur le camp retranché de Barrault

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

Report on a special investigation of the University of Northern Iowa, Camp Adventure Youth Services program for the period April 1, 2007 through March 31, 2008

Report on a special investigation of the University of Northern Iowa, Camp Adventure Youth Services program for the period April 1, 2007 through March 31, 2008

Un edifici volcànic inèdit a Caldes de Malavella (la Selva, Girona): el volcà del camp dels Ninots

Es descriu la morfologia i els dipòsits del volcà inèdit del camp dels Ninots (Caldes de Malavella)

Complex poliesportiu de Camp Clar

Concurs d’avantprojectes del Complex Poliesportiu de Camp Clar

Remodelació del Nou Camp del F.C. Barcelona

Proposta presentada per al Concurs de Remodelació del Nou Camp del Futbol Club Barcelona.

The promoter of the gene encoding 3',5'-cyclic adenosine monophosphate (cAMP) response element binding protein contains cAMP response elements: evidence for positive autoregulation of gene transcription.

The transcriptional transactivational activities of the phosphoprotein cAMP-response element-binding protein (CREB) are activated by the cAMP-dependent protein kinase A signaling pathway. Dimers of CREB bind to the palindromic DNA element 5'-TGACGTCA-3' (or similar motifs) called cAMP-responsive enhancers (CREs) found in the control regions of many genes, and activate transcription in response to phosphorylation of CREB by protein kinase A. Earlier we reported on the cyclical expression of the CREB gene in the Sertoli cells of the rat testis that occurred concomitant with the FSH-induced rise in cellular cAMP levels and suggested that transcription of the CREB gene may be autoregulated by cAMP-dependent transcriptional proteins. We now report the structure of the 5'-flanking sequence of the human CREB gene containing promoter activity. The promoter has a high content of guanosines and cytosines and lacks canonical TATA and CCAAT boxes typically found in the promoters of genes in eukaryotes. Notably, the promoter contains three CREs and transcriptional activities of a promoter-luciferase reporter plasmid transfected to placental JEG-3 cells are increased 3- to 5-fold over basal activities in response to either cAMP or 12-O-tetradecanoyl phorbol-14-acetate, and give 6- to 7-fold responses when both agents are added. The CREs bind recombinant CREB and endogenous CREB or CREB-like proteins contained in placental JEG-3 cells and also confer cAMP-inducible transcriptional activation to a heterologous minimal promoter. Our studies suggest that the expression of the CREB gene is positively autoregulated in trans.