Improved contractile potential in detrusor microtissues from pediatric patients with end stage lower urinary tract dysfunction

Autologous cell-based tissue engineering has been proposed as a treatment option for end stage lower urinary tract dysfunction (ESLUTD). However, it is generally accepted that cells isolated from patient bladders retain the pathological properties of their tissue of origin and therefore need to be improved before they can serve as a cell source for tissue engineering applications. We hypothesize that human three-dimensional (3D) microtissues of detrusor smooth muscle cells (SMCs) are valuable ex vivo disease models and potent building blocks for bladder tissue engineering. Detrusor SMCs isolated from bladder wall biopsies of pediatric ESLUTD patients and healthy controls were expanded and cultured into 3D microtissues. Gene and protein analyses were performed to explore the effect of microtissue formation on SMC viability, contractile potential, bladder wall specific extracellular matrix (ECM) composition and mediators of ECM remodeling. Through microtissue formation, remodeling and intensified cell-cell interactions, the ESLUTD SMCs lost their characteristic disease phenotype. These microtissues exhibited similar patterns of smooth muscle related contractile proteins and essential bladder wall-specific ECM components as microtissues from healthy control subjects. Thus, the presented data suggest improved contractile potential and ECM composition in detrusor SMC microtissues from pediatric ESLUTD patients. These findings are of great relevance, as 3D detrusor SMC microtissues might be an appropriate cell source for autologous cell-based bladder tissue engineering

The Lymnaea Cardioexcitatory Peptide (LyCEP) Receptor: A G-Protein–Coupled Receptor for a Novel Member of the RFamide Neuropeptide Family

A novel G-protein–coupled receptor (GRL106) resembling neuropeptide Y and tachykinin receptors was cloned from the molluscLymnaea stagnalis. Application of a peptide extract from the Lymnaea brain to Xenopus oocytes expressing GRL106 activated a calcium-dependent chloride channel. Using this response as a bioassay, we purified the ligand for GRL106,Lymnaea cardioexcitatory peptide (LyCEP), an RFamide-type decapeptide (TPHWRPQGRF-NH2) displaying significant similarity to the Achatina cardioexcitatory peptide (ACEP-1) as well as to the recently identified family of mammalian prolactin-releasing peptides. In the Lymnaeabrain, the cells that produce egg-laying hormone are the predominant site of GRL106 gene expression and appear to be innervated by LyCEP-containing fibers. Indeed, LyCEP application transiently hyperpolarizes isolated egg-laying hormone cells. In theLymnaea pericardium, LyCEP-containing fibers end blindly at the pericardial lumen, and the heart is stimulated by LyCEPin vitro. These data confirm that LyCEP is an RFamide ligand for GRL10

Decreased Survival of B Cells of HIV-viremic Patients Mediated by Altered Expression of Receptors of the TNF Superfamily

Human immunodeficiency virus (HIV) infection leads to numerous perturbations of B cells through mechanisms that remain elusive. We performed DNA microarray, phenotypic, and functional analyses in an effort to elucidate mechanisms of B cell perturbation associated with ongoing HIV replication. 42 genes were up-regulated in B cells of HIV-viremic patients when compared with HIV-aviremic and HIV-negative patients, the majority of which were interferon (IFN)-stimulated or associated with terminal differentiation. Flow cytometry confirmed these increases and indicated that CD21low B cells, enhanced in HIV-viremic patients, were largely responsible for the changes. Increased expression of the tumor necrosis factor (TNF) superfamily (TNFSF) receptor CD95 correlated with increased susceptibility to CD95-mediated apoptosis of CD21low B cells, which, in turn, correlated with HIV plasma viremia. Increased expression of BCMA, a weak TNFSF receptor for B lymphocyte stimulator (BLyS), on CD21low B cells was associated with a concomitant reduction in the expression of the more potent BLyS receptor, BAFF-R, that resulted in reduced BLyS binding and BLyS-mediated survival. These findings demonstrate that altered expression of genes associated with IFN stimulation and terminal differentiation in B cells of HIV-viremic patients lead to an increased propensity to cell death, which may have substantial deleterious effects on B cell responsiveness to antigenic stimulation