Gozde Yucel

Permissive and instructive anterior patterning rely on mRNA localization in the wasp embryo

The long-germ mode of embryogenesis, in which segments arise simultaneously along the anteriorposterior axis, has evolved several times in different lineages of the holometabolous, or fully metamorphosing, insects. Drosophilas long-germ fate map is established largely by the activity of the dipteran-specific Bicoid (Bcd) morphogen gradient, which operates both instructively and permissively to accomplish anterior patterning. By contrast, all nondipteran long-germ insects must achieve anterior patterning independently of bcd. We show that bcds permissive function is mimicked in the wasp by a maternal repression system in which anterior localization of the wasp ortholog of giant represses anterior expression of the trunk gap genes so that head and thorax can properly form.

Morphogens: Precise Outputs from a Variable Gradient

The morphogen gradient as a source of embryonic patterning is one of the best accepted concepts in developmental biology. Morphogens can be transcription factors or extracellular signals, but in both cases, they are thought to provide concentration thresholds that position different cell fates within the developing embryo. Several recent papers examine the patterning activities of Drosophila Bicoid, the first known molecular morphogen and reach different conclusions about the patterning power of a single morphogen gradient.

State-dependent signaling by Cav1.2 regulates hair follicle stem cell function

The signals regulating stem cell activation during tissue regeneration remain poorly understood. We investigated the baldness associated with mutations in the voltage-gated calcium channel (VGCC) Cav1.2 underlying Timothy syndrome (TS). While hair follicle stem cells express Cav1.2, they lack detectable voltage-dependent calcium currents. Cav1.2(TS) acts in a dominant-negative manner to markedly delay anagen, while L-type channel blockers act through Cav1.2 to induce anagen and overcome the TS phenotype. Cav1.2 regulates production of the bulge-derived BMP inhibitor follistatin-like1 (Fstl1), derepressing stem cell quiescence. Our findings show how channels act in nonexcitable tissues to regulate stem cells and may lead to novel therapeutics for tissue regeneration.

Bovine Papillomavirus Type 2 Infection and Microscopic Patterns of Urothelial Tumors of the Urinary Bladder in Water Buffaloes

Microscopic patterns of thirty-four urothelial tumors of the urinary bladder of water buffaloes from the Marmara and Black Sea Regions of Turkey are here described. All the animals grazed on lands rich in bracken fern. Histological diagnosis was assessed using morphological parameters recently suggested for the urinary bladder tumors of cattle. Papillary carcinoma was the most common neoplastic lesion (22/34) observed in this study, and low-grade carcinoma was more common (seventeen cases) than high-grade carcinoma (five cases). Papilloma, papillary urothelial neoplasm of low malignant potential (PUNLMP), and invasive carcinomas were less frequently seen. Carcinoma in situ (CIS) was often detected associated with some papillary and invasive carcinomas. De novo (primary) CIS was rare representing 3% of tumors of this series. A peculiar feature of the most urothelial tumors was the presence in the tumor stroma of immune cells anatomically organized in tertiary lymphoid organs (TLOs). Bovine papillomavirus type-2 (PV-2) E5 oncoprotein was detected by molecular and immunohistochemistry procedures. Early protein, E2, and late protein, L1, were also detected by immunohistochemical studies. Morphological and molecular findings show that BPV-2 infection contributes to the development of urothelial bladder carcinogenesis also in water buffaloes.

Evaluation of macrophage activation syndrome associated with systemic juvenile idiopathic arthritis: single center experience over a one-year period

AIM This study aimed to evaluate the demographic, clinical, laboratory properties of patients with macrophage activation syndrome and treatment outcomes. MATERIAL AND METHODS The data of the patients who were diagnosed with macrophage activation syndrome secondary to systemic juvenile idiopathic arthritis between June 2013-May 2014 were evaluated by screening patient records. RESULTS Ten patients with macrophage activation syndrome were followed up in one year. The mean age at the time of diagnosis was found to be 7.6±4.5 years. The most common clinical finding at presentation (80%) was increased body temperature. Hepatosplenomegaly was found in half of the patients. The most common hematological finding (90%) was anemia. The mean erythrocyte sedimentation rate was found to be 71.8±36.2 mm/h, whereas it was measured to be lower (31.2±25.2 mm/h) at the time of the diagnosis of macrophage activation syndrome. Increased ferritin level was found in all of our patients (the mean ferritin level was found to be 23 957±15 525 ng/mL). Hypertriglyceridemia was found in nine patients (90%). The mean triglyceride level was found to be 397±332 mg/dL. Systemic steroid treatment was administered to all patients. Cyclosporine A was given to eight patients (80%), canakinumab was given to four patients (40%) and anakinra was given to five patients (50%). Plasmapheresis was performed in two patients. Improvement was found in all patients except for one patient. The patient in whom no improvement was observed showed a chronic course. CONCLUSIONS The diagnosis of macrophage activation syndrome should be considered in presence of sudden disturbance in general condition, resistant high fever and systemic inflammation findings in children with active rheumatic disease. Complete recovery can be provided with early and efficient treatment in macrophage activation syndrome which develops secondary to systemic juvenil idiopathic arthritis.

The Urinary Tract Microbiome in Health and Disease

CONTEXT The urinary tract, previously considered a sterile body niche, has emerged as the host of an array of bacteria in healthy individuals, revolutionizing the urology research field. OBJECTIVE To review the literature on microbiome implications in the urinary tract and the usefulness of probiotics/prebiotics and diet as treatment for urologic disorders. EVIDENCE ACQUISITION A systematic review was conducted using PubMed and Medline from inception until July 2016. The initial search identified 1419 studies and 89 were included in this systematic review. EVIDENCE SYNTHESIS Specific bacterial communities have been found in the healthy urinary tract. Changes in this microbiome have been observed in certain urologic disorders such as urinary incontinence, urologic cancers, interstitial cystitis, neurogenic bladder dysfunction, sexually transmitted infections, and chronic prostatitis/chronic pelvic pain syndrome. The role of probiotics, prebiotics, and diet as treatment or preventive agents for urologic disorders requires further investigation. CONCLUSIONS There is a microbiome associated with the healthy urinary tract that can change in urologic disorders. This represents a propitious context to identify new diagnostic, prognostic, and predictive microbiome-based biomarkers that could be used in clinical urology practice. In addition, probiotics, prebiotics, and diet modifications appear to represent an opportunity to regulate the urinary microbiome. PATIENT SUMMARY We review the urinary microbiome of healthy individuals and its changes in relation to urinary disorders. The question to resolve is how we can modulate the microbiome to improve urinary tract health.

A feed-forward relay integrates the regulatory activities of Bicoid and Orthodenticle via sequential binding to suboptimal sites

The K50 (lysine at amino acid position 50) homeodomain (HD) protein Orthodenticle (Otd) is critical for anterior patterning and brain and eye development in most metazoans. In Drosophila melanogaster, another K50HD protein, Bicoid (Bcd), has evolved to replace Otds ancestral function in embryo patterning. Bcd is distributed as a long-range maternal gradient and activates transcription of a large number of target genes, including otd Otd and Bcd bind similar DNA sequences in vitro, but how their transcriptional activities are integrated to pattern anterior regions of the embryo is unknown. Here we define three major classes of enhancers that are differentially sensitive to binding and transcriptional activation by Bcd and Otd. Class 1 enhancers are initially activated by Bcd, and activation is transferred to Otd via a feed-forward relay (FFR) that involves sequential binding of the two proteins to the same DNA motif. Class 2 enhancers are activated by Bcd and maintained by an Otd-independent mechanism. Class 3 enhancers are never bound by Bcd, but Otd binds and activates them in a second wave of zygotic transcription. The specific activities of enhancers in each class are mediated by DNA motif variants preferentially bound by Bcd or Otd and the presence or absence of sites for cofactors that interact with these proteins. Our results define specific patterning roles for Bcd and Otd and provide mechanisms for coordinating the precise timing of gene expression patterns during embryonic development.

Dietary Fructose-Induced Hepatic Injury in Male and Female Rats: Influence of Resveratrol.

Purpose: Relatively little is known about gender-dependent susceptibility to hepatic injury induced by nutritional factors. In the current study, we investigated dietary fructose-induced hepatic degeneration and roles of endothelial nitric oxide synthase (eNOS), insulin receptor (IRβ) and substrate-1 (IRS-1) expressions in association with inflammatory markers in male and female rats. Moreover, we examined potential effect of resveratrol on fructose-induced changes. Methods: Male and female rats were divided into 4 groups as control, resveratrol, fructose and resveratrol plus fructose. All rats were fed with a standard diet with or without resveratrol (500 mg/kg). Fructose was given as 10% in drinking waterfor 24 weeks. Results: Long-term dietary fructose caused parenchymal degeneration and hyperemia in association with impaired eNOS mRNA/protein expressions in liver of male and female rats. This dietary intervention also led to increases in hepatic triglyceride content, TNFα and IL-1β levels in both genders. Gender-related differences to consequence of fructose consumption were not obvious. Resveratrol supplementation markedly attenuated hepatic degeneration, hyperemia and triglyceride content in association with reduced TNFα and IL-1β levels, but enhanced IRβ mRNA and IRS-1 protein, in male and female rats upon fructose feeding. Conclusion: Long-term dietary fructose causes hepatic degeneration possibly via a decrease in eNOS, but increase in TNFα and IL-1β, in both genders. Resveratrol supplementation improved fructose-induced hepatic injury.

Articular involvement in childhood Familial Mediterranean Fever

Familial Mediterranean fever is an autosomal recessively inherited autoinflammatory disease which is clinically manifested with periodic episodes of fever, serositis and arthritis. Articular involvement is also a frequent presentation after fever and peritonitis in childhood FMF.

Partial proteasome inhibitors induce hair follicle growth by stabilizing β-catenin.

The activation of tissue stem cells from their quiescent state represents the initial step in the complex process of organ regeneration and tissue repair. While the identity and location of tissue stem cells are becoming known, how key regulators control the balance of activation and quiescence remains mysterious. The vertebrate hair is an ideal model system where hair cycling between growth and resting phases is precisely regulated by morphogen signaling pathways, but how these events are coordinated to promote orderly signaling in a spatial and temporal manner remains unclear. Here, we show that hair cycle timing depends on regulated stability of signaling substrates by the ubiquitin‐proteasome system. Topical application of partial proteasomal inhibitors (PaPIs) inhibits epidermal and dermal proteasome activity throughout the hair cycle. PaPIs prevent the destruction of the key anagen signal β‐catenin, resulting in more rapid hair growth and dramatically shortened telogen. We show that PaPIs induce excess β‐catenin, act similarly to the GSK3β antagonist LiCl, and antagonize Dickopf‐related protein‐mediated inhibition of anagen. PaPIs thus represent a novel class of hair growth agents that act through transiently modifying the balance of stem cell activation and quiescence pathways. Stem Cells 2014;32:85–92