There is an emerging understanding of the importance of the vascular system within stem cell niches. Here we examine whether neural stem cells (NSCs) in the adult subventricular zone (SVZ) lie close to blood vessels, using 3-dimensional wholemounts, confocal microscopy and automated computer-based image quantification. We found that the SVZ contains a rich plexus of blood vessels that snake along and within neuroblast chains. Cells expressing stem cell markers, including GFAP, and proliferation markers, are closely apposed to the laminin-containing extracellular matrix (ECM) surrounding vascular endothelial cells. Apical GFAP+ cells are admixed within the ependymal layer and some span between the ventricle and blood vessels, occupying a specialized microenvironment. Adult SVZ progenitor cells express the laminin receptor alpha6beta1 integrin, and blocking this inhibits their adhesion to endothelial cells, altering their position and proliferation in vivo, indicating it plays a functional role in binding SVZ stem cells within the vascular niche.

Aims:The aims of the present study were to investigate voiding patterns, tissue constituents and the expressions of cyclooxygenase-2 (COX-2) and nitric oxide synthase (NOS) involved in ketamine-induced ulcerative cystitis in rat urinary bladder. Methods: Thirty Sprague-Dawley rats were distributed into three groups which received saline or ketamine (25 mg/kg/day) for a period of 14 and 28 days. In each group, cystometry was performed weekly and the concentration of ketamine and its metabolites (norketamine) was assayed. Paraffin-embedded sections were stained with Masson's trichrome stain, and ketamine-induced morphological changes were examined. Western blot analyses were carried out to examine the expressions of COX-2 and different NOS isoforms in bladder tissues. Immunofluorescence study was done to evaluate the expressions of COX-2 and macrophage infiltration (stained with ED-1 macrophage cell surface antigen) within the bladder. Results: Ketamine treatment resulted in bladder hyperactivity and the non-voiding contractions were significantly increased. The urine concentrations of ketamine and norketamine were much higher in ketamine-treated group. Moreover, ulcerated urothelium and mononuclear cell infiltration were noted in ketamine-treated group. These alterations in urodynamic functions and tissue constituents were accompanied by increases in the expression of COX-2. Two NOS isoforms (iNOS and eNOS) were also overexpressed, but no significant change was observed for nNOS. COX-2 positive stained cells were significantly increased. Meanwhile, increased amounts of ED-1 positive stained macrophages were present and most of COX-2 expressed cells were co-stained with ED-1 in the early stage of ketamine treatment. Conclusions: Ketamine treatment affected bladder tissues by enhancing interstitial fibrosis and accelerating macrophages infiltration. Ketamine also initiated the up-regulations of COX-2 and iNOS and eNOS expressions. These up-regulated enzymes might play an important role in contributing to ketamine-induced alterations in micturition patterns and ulcerative cystitis.

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What ' s known on the subject? and What does the study add? Ovary hormone defi ciency and the age-related changes in post-menopausal women are subjected to a number of urological dysfunctions, including overactive bladder syndrome. Green tea is a popular healthy drink worldwide and its extract catechin has strong anti-infl ammatory and antioxidant properties.EGCG, the major type of catechin, is an antioxidant polyphenol fl avonoid isolated from green tea. EGCG supplement could prevent ovariectomy-induced bladder dysfunction in a dose-related manner through its anti-oxidant, anti-fi brosis and anti-apoptosis effects.

The current study clearly demonstrates that coenzyme Q10 and alpha-lipoic acid supplementation can improve bladder function after outlet obstruction.