Sonic hedgehog signaling from the urethral epithelium controls external genital development

External genital development begins with formation of paired genital swellings, which develop into the genital tubercle. Proximodistal outgrowth and axial patterning of the genital tubercle are coordinated to give rise to the penis or clitoris. The genital tubercle consists of lateral plate mesoderm, surface ectoderm, and endodermal urethral epithelium derived from the urogenital sinus. We have investigated the molecular control of external genital development in the mouse embryo. Previous work has shown that the genital tubercle has polarizing activity, but the precise location of this activity within the tubercle is unknown. We reasoned that if the tubercle itself is patterned by a specialized signaling region, then polarizing activity may be restricted to a subset of cells. Transplantation of urethral epithelium, but not genital mesenchyme, to chick limbs results in mirror-image duplication of the digits. Moreover, when grafted to chick limbs, the urethral plate orchestrates morphogenetic movements normally associated with external genital development. Signaling activity is therefore restricted to urethral plate cells. Before and during normal genital tubercle outgrowth, urethral plate epithelium expresses Sonic hedgehog (Shh). In mice with a targeted deletion of Shh, external genitalia are absent. Genital swellings are initiated, but outgrowth is not maintained. In the absence of Shh signaling, Fgf8, Bmp2, Bmp4, Fgf10, and Wnt5a are downregulated, and apoptosis is enhanced in the genitalia. These results identify the urethral epithelium as a signaling center of the genital tubercle, and demonstrate that Shh from the urethral epithelium is required for outgrowth, patterning, and cell survival in the developing external genitalia.     

Pre- and Posttranslational Regulation of β-Endorphin Biosynthesis in the CNS: Effects of Chronic Naltrexone Treatment

Abstract: There appear to be two anatomically distinct β-endorphin (βE) pathways in the brain, the major one originating in the arcuate nucleus of the hypothalamus and a smaller one in the area of the nucleus tractus solitarius (NTS) of the caudal medulla. Previous studies have shown that these two proopiomelanocortin (POMC) systems may be differentially regulated by chronic morphine treatment, with arcuate cells down-regulated and NTS cells unaffected. In the present experiments, we examined the effects of chronic opiate antagonist treatment on βE biosynthesis across different CNS regions to assess whether the arcuate POMC system would be regulated in the opposite direction to that seen after opiate agonist treatment and to determine whether different βE-containing areas might be differentially regulated. Male adult rats were administered naltrexone (NTX) by various routes for 8 days (subcutaneous pellets, osmotic minipumps, or repeated intraperitoneal injections). Brain and spinal cord regions were assayed for total βE-ir, different molecular weight immunoreactive β-endorphin (βE-ir) peptides, and POMC mRNA. Chronic NTX treatment, regardless of the route of administration, reduced total βE-ir concentrations by 30–40% in diencephalic areas (the arcuate nucleus, the remaining hypothalamus, and the thalamus) and the midbrain, but had no effect on βE-ir in the NTS or any region of the spinal cord. At the same time, NTX pelleting increased POMC mRNA levels in the arcuate to ～ 140% of control values. These data suggest that arcuate POMC neurons are up-regulated after chronic NTX treatment (whereas NTS and spinal cord systems remain unaffected) and that they appear to be under tonic inhibition by endogenous opioids. Chromatographic analyses demonstrated that, after chronic NTX pelleting, the ratio of full length βE_1–31 to more processed βE-ir peptides (i.e., βE_1–27 and βE_1–26) tended to increase in a dose-dependent manner in diencephalic areas. Because βE_1–31 is the only POMC product that possesses opioid agonist properties, and βE_1–27 has been posited to function as an endogenous anatgonist of βE_1–31, the NTX-induced changes in the relative concentrations of βE_1–31 and βE_1–27/βE_1–26 may represent a novel regulatory mechanism of POMC cells to alter the opioid signal in the synapse.     

Coaggregation between Aquatic Bacteria Is Mediated by Specific-Growth-Phase-Dependent Lectin-Saccharide Interactions

Coaggregating strains of aquatic bacteria were identified by partial 16S rRNA gene sequencing. The coaggregation abilities of four strains of Blastomonas natatoria and one strain of Micrococcus luteus varied with culture age but were always maximum in the stationary phase of growth. Each member of a coaggregating pair carried either a heat- and protease-sensitive protein (lectin) adhesin or a saccharide receptor, as coaggregation was reversed by sugars.     

Multivariate analysis of metastasis risk in laryngeal carcinoma. II. Immune response

The presence of inflammatory reaction, plasma cells, and eosinophils in peritumoral connective tissue and in neoplastic stroma was evaluated with morphometrical method in 181 patients affected by laryngeal carcinoma. A logistic multiple regression model was applied making it with the use of an independent variable represented by the "infiltrating" or "expansive" types of tumor growth, in order to evaluate the probability of nodal metastatsis of each parameter. The results suggest an inverse correlationship between plasma cells and inflammatory infiltration and incidence of nodal metastatsis only in the comparison of the extreme conditions: those with scarce infiltration versus the ones with large infiltration. Inflammatory or plasmacellular infiltration may represent both a defense mechanism against cancer and an aspecific or allergic reaction. The eosinophilic infiltration shows no value in the prevention of nodal involvement.     

Assembly and regulation of the cytokinetic apparatus in budding yeast

The identification of an actomyosin-based contractile ring in budding yeast has recently established this organism as a general model for studying cytokinesis. Work over the past three years has provided important new insights into the conserved mechanisms underlying the assembly and regulation of the cytokinetic structures. This review covers the recent progress in studying cytokinesis in budding yeast.     

L-5-Hydroxytryptophan: antioxidant and anti-apoptotic principle of the intertidal sponge Hymeniacidon heliophila

The intertidal sponge Hymeniacidon heliophila which survives under intense sunlight contains the antioxidant amino acid L-5-hydroxytryptophan (L-5-HTP) as major constituent. The content of L-5-HTP was determined as (0.45 +/- 0.23)% of the dry weight by quantitative NMR-spectroscopical analysis with an internal standard. Other known antioxidants such as flavonoids, carotenoids or tocopherol derivatives were absent. Both the oxidation potential and the concentration of L-5-HTP in H. heliophila correspond to the values observed for flavonoids being major antioxidants in plants. It was shown that L-5-HTP suppresses UV-induced apoptosis in human monocytes at the same concentrations as it occurs in the sponge tissue.     

Quantitative capillary electrophoresis determination of oversulfated chondroitin sulfate as a contaminant in heparin preparations

A simple, accurate, and robust quantitative capillary electrophoresis (CE) method for the determination of oversulfated chondroitin sulfate (OSCS) as a contaminant in heparin (Hep) preparations is described. After degradation of the polysaccharides by acidic hydrolysis, the hexosamines produced (i.e., GlcN from Hep and GalN from OSCS) were derivatized with anthranilic acid (AA) and separated by means of CE in approximately 10 min with high sensitivity detection at 214 nm (limit of detection [LOD] of ∼200 pg). Furthermore, AA-derivatized GlcN and GalN showed quite similar molar absorptivity, allowing direct and simple quantification of OSCS in Hep samples. Moreover, a preliminary step of specific enzymatic treatment by using chondroitin ABC lyase may be applied for the specific elimination of interference in the analysis due to the possible presence in Hep samples of natural chondroitin sulfate and dermatan sulfate impurities, making this analytical approach highly specific for OSCS contamination given that chondroitin ABC lyase is unable to act on this semisynthetic polymer. The CE method was validated for specificity, linearity, accuracy, precision, LOD, and limit of quantification (LOQ). Due to the very high sensitivity of CE, as little as 1% OSCS contaminant in Hep sample could be detected and quantified. Finally, a contaminated raw Hep sample was found to contain 38.9% OSCS, whereas a formulated contaminated Hep was calculated to have 39.7% OSCS.     

Cyclin-dependent kinase inhibitors enhance the resolution of inflammation by promoting inflammatory cell apoptosis

Apoptosis is essential for clearance of potentially injurious inflammatory cells and subsequent efficient resolution of inflammation. Here we report that human neutrophils contain functionally active cyclin-dependent kinases (CDKs), and that structurally diverse CDK inhibitors induce caspase-dependent apoptosis and override powerful anti-apoptosis signals from survival factors such as granulocyte-macrophage colony-stimulating factor (GM-CSF). We show that the CDK inhibitor R-roscovitine (Seliciclib or CYC202) markedly enhances resolution of established neutrophil-dependent inflammation in carrageenan-elicited acute pleurisy, bleomycin-induced lung injury, and passively induced arthritis in mice. In the pleurisy model, the caspase inhibitor zVAD-fmk prevents R-roscovitine-enhanced resolution of inflammation, indicating that this CDK inhibitor augments inflammatory cell apoptosis. We also provide evidence that R-roscovitine promotes apoptosis by reducing concentrations of the anti-apoptotic protein Mcl-1. Thus, CDK inhibitors enhance the resolution of established inflammation by promoting apoptosis of inflammatory cells, thereby demonstrating a hitherto unrecognized potential for the treatment of inflammatory disorders.     

Biomarkers for atherosclerosis: pathophysiological role and pharmacological modulation

PURPOSE OF REVIEW: The aim of this article is to discuss the potential value of biomarkers for atherosclerosis in the assessment of risk for cardiovascular disease, in the pathogenesis of atherosclerosis, and in the monitoring of pharmacological treatment. RECENT FINDINGS: In an attempt to improve global cardiovascular risk prediction, considerable effort has been made in the discovery and characterization of soluble biomarkers which can go beyond the measure of total and LDL cholesterol levels. In particular, circulating molecules related to chronic inflammation have emerged as potential biomarkers for atherosclerosis. Evidence, obtained from in-vitro and in-vivo experimental models, has also documented that the majority of biomarkers play a pathological role in atherogenesis. Multiple screening of different biomarkers may therefore improve the assessment of risk, diagnosis, and prognosis for cardiovascular disease. In addition, soluble biomarkers have been shown to be modulated by hypolipidemic drugs and to be potentially useful in determining the clinical benefits of pharmacological therapies that do not alter serum lipid levels. SUMMARY: Altered levels of soluble biomarkers are associated with cardiovascular disease, and profiling of multiple biomarkers for atherosclerosis will be a useful indicator for better risk assessment, diagnosis, and prognosis, as well as monitoring pharmacological treatments for atherosclerosis.