The 2003 American Urological Association (AUA) guideline on management of benign prostatic hyperplasia (BPH) was released at the AUA annual meeting in Chicago, April 2003 and the diagnosis and ...treatment recommendations were published later in 2003. It is likely that the 2003 AUA guideline on the management of BPH will have a profound effect on clinical urologic practice in the USA, but its influence on Canadian urological practice will be different because of our socialized medical system, manpower issues, availability of expensive technology and our unique Canadian perspective. The authors review the 2003 AUA guideline on the management of BPH and based on a perspective obtained from recent publications, consensus/consultant meetings, focus groups and anecdotal experience, attempt to put the recommendations into Canadian context. We conclude that the 2003 AUA guideline for the management of BPH is an important document that should be studied, evaluated and understood by Canadian urologists. Although our perspective is clearly different than our US colleagues, it is likely that the guideline will influence the management of BPH in Canada.
Complex cellular networks regulate regeneration, detoxification and differentiation of hepatocytes. By combining experimental data with mathematical modelling, systems biology holds great promises to ...elucidate the key regulatory mechanisms involved and predict targets for efficient intervention. For the generation of high-quality quantitative data suitable for mathematical modelling a standardised in vitro system is essential. Therefore the authors developed standard operating procedures for the preparation and cultivation of primary mouse hepatocytes. To reliably monitor the dynamic induction of signalling pathways, the authors established starvation conditions and evaluated the extent of starvation-associated stress by quantifying several metabolic functions of cultured primary hepatocytes, namely activities of glutathione-S-transferase, glutamine synthetase, CYP3A as well as secretion of lactate and urea into the culture medium. Establishment of constant metabolic activities after an initial decrease compared with freshly isolated hepatocytes showed that the cultured hepatocytes achieve a new equilibrium state that was not affected by our starving conditions. To verify the highly reproducible dynamic activation of signalling pathways in the in vitro system, the authors examined the JAK-STAT, SMAD, PI3 kinase, MAP kinase, NF-kappaB and Wnt/beta-catenin signalling pathways. For the induction of gp130, JAK1 and STAT3 phosphorylation IL6 was used, whereas TGFbeta was applied to activate the phosphorylation of SMAD1, SMAD2 and SMAD3. Both Akt/PKB and ERK1/2 phosphorylation were stimulated by the addition of hepatocyte growth factor. The time-dependent induction of a pool of signalling competent beta-catenin was monitored in response to the inhibition of GSK3beta. To analyse whether phosphorylation is actually leading to transcriptional responses, luciferase reporter gene constructs driven by multiple copies of TGFbeta-responsive motives were applied, demonstrating a dose-dependent increase in luciferase activity. Moreover, the induction of apoptosis by the TNF-like cytokine Fas ligand was studied in the in vitro system. Thus, the mouse hepatocyte in vitro system provides an important basis for the generation of high-quality quantitative data under standardised cell culture conditions that is essential to elucidate critical hepatocellular functions by the systems biology approach.
Bone morphogenetic protein-2 (BMP-2) and other members of the TGF-beta superfamily regulate the development, maintenance and regeneration of tissues and organs. Binding epitopes for these ...extracellular signaling proteins have been defined, but hot spots specifying binding affinity and specificity have so far not been identified. In this study, mutational and structural analyses show that epitopes of BMP-2 and the BRIA receptor form a new type of protein-protein interface. The main chain atoms of Leu 51 and Asp53 of BMP-2 represent a hot spot of binding to BRIA. The BMP-2 variant L51P was deficient in type I receptor binding only, whereas its overall structure and its binding to type II receptors and modulator proteins, such as noggin, were unchanged. Thus, the L51P substitution converts BMP-2 into a receptor-inactive inhibitor of noggin. These results are relevant for other proteins of the TGF-beta superfamily and provide useful clues for structure-based drug design.
Bone morphogenetic protein‐2 (BMP‐2) induces bone formation and regeneration in adult vertebrates and regulates important developmental processes in all animals. BMP‐2 is a homodimeric cysteine knot ...protein that, as a member of the transforming growth factor‐β (TGF‐β) superfamily, signals by oligomerizing type I and type II receptor serine‐kinases in the cell membrane. The binding epitopes of BMP‐2 for BMPR‐IA (type I) and BMPR‐II or ActR‐II (type II) were characterized using BMP‐2 mutant proteins for analysis of interactions with receptor ectodomains. A large epitope 1 for high‐affinity BMPR‐IA binding was detected spanning the interface of the BMP‐2 dimer. A smaller epitope 2 for the low‐affinity binding of BMPR‐II was found to be assembled by determinants of a single monomer. Symmetry‐related pairs of the two juxtaposed epitopes occur near the BMP‐2 poles. Mutations in both epitopes yielded variants with reduced biological activity in C2C12 cells; however, only epitope 2 variants behaved as antagonists partially or completely inhibiting BMP‐2 activity. These findings provide a framework for the molecular description of receptor recognition and activation in the BMP/TGF‐β superfamily.
The "Multidisciplinary Approach to the Study of Chronic Pelvic Pain" (MAPP) Research Network was established by the NIDDK to better understand the pathophysiology of urologic chronic pelvic pain ...syndromes (UCPPS), to inform future clinical trials and improve clinical care. The evolution, organization, and scientific scope of the MAPP Research Network, and the unique approach of the network's central study and common data elements are described.
The primary scientific protocol for the Trans-MAPP Epidemiology/Phenotyping (EP) Study comprises a multi-site, longitudinal observational study, including bi-weekly internet-based symptom assessments, following a comprehensive in-clinic deep-phenotyping array of urological symptoms, non-urological symptoms and psychosocial factors to evaluate men and women with UCPPS. Healthy controls, matched on sex and age, as well as "positive" controls meeting the non-urologic associated syndromes (NUAS) criteria for one or more of the target conditions of Fibromyalgia (FM), Chronic Fatigue Syndrome (CFS) or Irritable Bowel Syndrome (IBS), were also evaluated. Additional, complementary studies addressing diverse hypotheses are integrated into the Trans-MAPP EP Study to provide a systemic characterization of study participants, including biomarker discovery studies of infectious agents, quantitative sensory testing, and structural and resting state neuroimaging and functional neurobiology studies. A highly novel effort to develop and assess clinically relevant animal models of UCPPS was also undertaken to allow improved translation between clinical and mechanistic studies. Recruitment into the central study occurred at six Discovery Sites in the United States, resulting in a total of 1,039 enrolled participants, exceeding the original targets. The biospecimen collection rate at baseline visits reached nearly 100%, and 279 participants underwent common neuroimaging through a standardized protocol. An extended follow-up study for 161 of the UCPPS participants is ongoing.
The MAPP Research Network represents a novel, comprehensive approach to the study of UCPPS, as well as other concomitant NUAS. Findings are expected to provide significant advances in understanding UCPPS pathophysiology that will ultimately inform future clinical trials and lead to improvements in patient care. Furthermore, the structure and methodologies developed by the MAPP Network provide the foundation upon which future studies of other urologic or non-urologic disorders can be based.
ClinicalTrials.gov identifier: NCT01098279 "Chronic Pelvic Pain Study of Individuals with Diagnoses or Symptoms of Interstitial Cystitis and/or Chronic Prostatitis (MAPP-EP)". http://clinicaltrials.gov/show/NCT01098279.
Growth and differentiation factor 5 (GDF-5), a member of the TGF-β superfamily, is involved in many developmental processes, like chondrogenesis and joint formation. Mutations in GDF-5 lead to ...diseases, e.g. chondrodysplasias like Hunter-Thompson, Grebe and DuPan syndromes and brachydactyly. Similar to other TGF-β superfamily members, GDF-5 transmits signals through binding to two different types of membrane-bound serine-/threonine-kinase receptors termed type I and type II. In contrast to the large number of ligands, only seven type I and five type II receptors have been identified to date, implicating a limited promiscuity in ligand–receptor interaction. However, in contrast to other members of the TGF-β superfamily, GDF-5 shows a pronounced specificity in type I receptor interaction in cross-link experiments binding only to BMP receptor IB (BMPR-IB). In mice, deletion of either GDF-5 or BMPR-IB results in a similar phenotype, indicating that GDF-5 signaling is highly dependent on BMPR-IB. Here, we demonstrate by biosensor analysis that GDF-5 also binds to BMP receptor IA (BMPR-IA) but with ∼12-fold lower affinity. Structural and mutational analyses revealed a single residue of GDF-5, Arg57 located in the pre-helix loop, being solely responsible for the high binding specificity to BMPR-IB. In contrast to wild-type GDF-5, variant GDF-5R57A interacts with BMPR-IA and BMPR-IB with a comparable high binding affinity. These results provide important insights into how receptor-binding specificity is generated at the molecular level and might be useful for the generation of receptor subtype specific activators or inhibitors.
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