E-Cadherin mediates UVR- and calcium-induced melanin transfer in human skin cells

yesSkin pigmentation is directed by epidermal-melanin units, characterized by long-lived and dendritic epidermal melanocytes (MC) that interact with viable keratinocytes (KC) to contribute melanin to the epidermis. Previously we reported that MC:KC contact is required for melanosome transfer, that this can be enhanced by filopodial and by UVR/UVA irradiation, which can up-regulate melanosome transfer via Myosin X-mediated control of MC filopodia. Both MC and KC express Ca2+-dependent E-cadherins. These homophilic adhesion contacts induce transient increases in intra-KC Ca2+, while ultraviolet radiation (UVR) raises intra-MC Ca2+ via calcium selective ORAI1 ion channels; both are associated with regulating melanogenesis. However, how Ca2+ triggers melanin transfer remains unclear, and here we evaluated the role of E-Cadherin in UVR-mediated melanin transfer in human skin cells. MC and KC in human epidermis variably express filopodia-associated E-Cadherin, Cdc42, VASP and β-catenin, all of which were upregulated by UVR/UVA in human MC in vitro. Knockdown of E-cadherin revealed that this cadherin is essential for UVR-induced MC filopodia formation and melanin transfer. Moreover, Ca2+ induced a dose-dependent increase in filopodia formation and melanin transfer, as well as increased β-catenin, Cdc42, Myosin X, and E-Cadherin expression in these skin cells. Together these data suggest that filopodial proteins and E-Cadherin, which are upregulated by intracellular (UVR-stimulated) and extracellular Ca2+ availability, are required for filopodia formation and melanin transfer. This may open new avenues to explore how Ca2+ signalling influences human pigmentation

Refining the phenotype associated with biallelic DNAJC21 mutations

Accepted manuscriptInherited bone marrow failure syndromes (IBMFS) are caused by mutations in genes involved in genomic stability. Although they may be recognized by the association of typical clinical features, variable penetrance and expressivity are common, and clinical diagnosis is often challenging. DNAJC21, which is involved in ribosome biogenesis, was recently linked to bone marrow failure. However, the specific phenotype and natural history remain to be defined. We correlate molecular data, phenotype, and clinical history of 5 unreported affected children and all individuals reported in the literature. All patients present features consistent with IBMFS: bone marrow failure, growth retardation, failure to thrive, developmental delay, recurrent infections, and skin, teeth or hair abnormalities. Additional features present in some individuals include retinal abnormalities, pancreatic insufficiency, liver cirrhosis, skeletal abnormalities, congenital hip dysplasia, joint hypermobility, and cryptorchidism. We suggest that DNAJC21-related diseases constitute a distinct IBMFS, with features overlapping Shwachman-Diamond syndrome and Dyskeratosis congenita, and additional characteristics that are specific to DNAJC21 mutations. The full phenotypic spectrum, natural history, and optimal management will require more reports. Considering the aplastic anemia, the possible increased risk for leukemia, and the multisystemic features, we provide a checklist for clinical evaluation at diagnosis and regular follow-up.FCT—Fundação para a Ciência e a Tecnologia (SFRH/BD/84650/2010)info:eu-repo/semantics/publishedVersio

Targeting Bone Alleviates Osteoarthritis in Osteopenic Mice and Modulates Cartilage Catabolism

Subchondral bone modifications occur early in the development of osteoarthritis (OA). The level of bone resorption might impact cartilage remodeling. We therefore assessed the in vivo and in vitro effects of targeting bone resorption in OA and cartilage metabolism.OA was induced by meniscectomy (MNX) in ovariectomized osteopenic mice (OP) treated with estradiol (E2), pamidronate (PAM), or phosphate buffered saline (PBS) for 6 weeks. We assessed the subchondral bone and cartilage structure and the expression of cartilage matrix proteases. To assess the involvement of bone soluble factors in cartilage metabolism, supernatant of human bone explants pre-treated with E2 or PAM were transferred to cartilage explants to assess proteoglycan release and aggrecan cleavage. OPG/RANKL mRNA expression was assessed in bone explants by real-time quantitative PCR. The role of osteoprotegerin (OPG) in the bone-cartilage crosstalk was tested using an OPG neutralizing antibody.Bone mineral density of OP mice and osteoclast number were restored by E2 and PAM (p<0.05). In OP mice, E2 and PAM decreased ADAMTS-4 and -5 expression, while only PAM markedly reduced OA compared to PBS (2.0±0.63 vs 5.2±0.95; p<0.05). OPG/RANKL mRNA was increased in human bone explants treated with both drugs (2.2-3.7-fold). Moreover, supernatants from bone explants cultured with E2 or PAM reduced aggrecan cleavage and cartilage proteoglycan release (73±8.0% and 80±22% of control, respectively, p<0.05). This effect was reversed with osteoprotegerin blockade.The inhibition of bone resorption by pamidronate in osteopenic mice alleviates the histological OA score with a reduction in the expression of aggrecanases. Bone soluble factors, such as osteoprotegerin, impact the cartilage response to catabolic factors. This study further highlights the importance of subchondral bone in the regulation of joint cartilage damage in OA

Pessaries in multiple pregnancy as a prevention of preterm birth: the ProTwin Trial

Contains fulltext : 79491.pdf (publisher's version ) (Open Access)BACKGROUND: Multiple pregnancies are at high risk for preterm birth, and therefore an important cause of infant mortality and morbidity. A pessary is a simple and potentially effective measure for the prevention of preterm birth. Small studies have indicated its effectiveness, but large studies with sufficient power on the subject are lacking. Despite this lack of evidence, the treatment is at present applied by some gynaecologists in The Netherlands. METHODS/DESIGN: We aim to investigate the hypothesis that prophylactic use of a cervical pessary will be effective in the prevention of preterm delivery and the neonatal mortality and morbidity resulting from preterm delivery in multiple pregnancy. We will evaluate the costs and effects of this intervention. At study entry, cervical length will be measured. Eligible women will be randomly allocated to receive either a cervical pessary or no intervention. The cervical pessary will be placed in situ at 16 to 20 weeks, and will stay in situ up to 36 weeks gestation or until delivery, whatever comes first.The primary outcome is composite bad neonatal condition (perinatal death or severe morbidity). Secondary outcome measures are time to delivery, preterm birth rate before 32 and 37 weeks, days of admission in neonatal intensive care unit, maternal morbidity, maternal admission days for preterm labour and costs. We need to include 660 women to indicate a reduction in bad neonatal outcome from 7.2% without to 3.9% with a cervical pessary, using a two-sided test with an alpha of 0.05 and a power of 0.80. DISCUSSION: This trial will provide evidence on whether a cervical pessary will decrease the incidence of early preterm birth and its concomitant bad neonatal outcome in multiple pregnancies. TRIAL REGISTRATION: Current Controlled Trials: NTR 1858

Non-Antioxidant Properties of α-Tocopherol Reduce the Anticancer Activity of Several Protein Kinase Inhibitors In Vitro

The antioxidant properties of α-tocopherol have been proposed to play a beneficial chemopreventive role against cancer. However, emerging data also indicate that it may exert contrasting effects on the efficacy of chemotherapeutic treatments when given as dietary supplement, being in that case harmful for patients. This dual role of α-tocopherol and, in particular, its effects on the efficacy of anticancer drugs remains poorly documented. For this purpose, we studied here, using high throughput flow cytometry, the direct impact of α-tocopherol on apoptosis and cell cycle arrest induced by different cytotoxic agents on various models of cancer cell lines in vitro. Our results indicate that physiologically relevant concentrations of α-tocopherol strongly compromise the cytotoxic and cytostatic action of various protein kinase inhibitors (KI), while other classes of chemotherapeutic agents or apoptosis inducers are unaffected by this vitamin. Interestingly, these anti-chemotherapeutic effects of α-tocopherol appear to be unrelated to its antioxidant properties since a variety of other antioxidants were completely neutral toward KI-induced cell cycle arrest and cell death. In conclusion, our data suggest that dietary α-tocopherol could limit KI effects on tumour cells, and, by extent, that this could result in a reduction of the clinical efficacy of anti-cancer treatments based on KI molecules

18 years of results with cemented primary hip prostheses in the Norwegian Arthroplasty Register: Concerns about some newer implants

Background and purpose Few studies have compared the long-term survival of cemented primary total hip arthroplasties (THAs), and several prostheses have been used without adequate knowledge of their endurance. We studied long-term outcome based on data in the Norwegian Arthroplasty Register

Effects of clusterin over-expression on metastatic progression and therapy in breast cancer

<p>Abstract</p> <p>Background</p> <p>Clusterin is a secreted glycoprotein that is upregulated in a variety of cell lines in response to stress, and enhances cell survival. A second nuclear isoform of clusterin that is associated with cell death has also been identified. The aim of this study was to determine the role(s) of the secretory isoform in breast tumor progression and metastasis.</p> <p>Methods</p> <p>To investigate the role of secretory clusterin in the biology of breast cancer tumor growth and resistance to therapy we have engineered an MCF-7 cell line (MCF-7CLU) that over-expresses clusterin. We have measured the <it>in vitro </it>effects of clusterin over-expression on cell cycle, cell death, and sensitivity to TNFalpha and tamoxifen. Using an orthotopic model of breast cancer, we have also determined the effects of over-expression of clusterin on tumor growth and metastatic progression.</p> <p>Results</p> <p>In vitro, over-expression of secretory clusterin alters the cell cycle kinetics and decreases the rate of cell death, resulting in the enhancement of cell growth. Over-expression of secretory clusterin also blocks the TNFalpha-mediated induction of p21 and abrogates the cleavage of Bax to t-Bax, rendering the MCF-7CLU cells significantly more resistant to the cytokine than the parental cells. Orthotopic primary tumors derived from MCF-7CLU cells grow significantly more rapidly than tumors derived from parental MCF-7 cells and, unlike the parental cells, metastasize frequently to the lungs.</p> <p>Conclusions</p> <p>These data suggest that secretory clusterin, which is frequently up-regulated in breast cancers by common therapies, including anti-estrogens, may play a significant role in tumor growth, metastatic progression and subsequent drug resistance in surviving cells.</p

Abordagem da artroplastia total do joelho no Brasil: estudo transversal

CONTEXT AND OBJECTIVE: Total knee arthroplasty (TKA) has evolved particularly since the 1970s, with improvements in implants and surgical instruments, and has thus become an effective intervention for treating knee arthrosis. Many studies have presented rates of satisfactory clinical and radiological results greater than 90%, from follow-ups of over ten years. Nevertheless, despite scientific evidence showing the efficacy of TKA, the approaches taken present controversies in certain respects. The objective of this study was to evaluate how the Brazilian orthopedists deal with TKA, with investigation of the main aspects of this procedure. DESIGN AND SETTING: Cross-sectional survey conducted during the 39th Brazilian Congress of Orthopedics and Traumatology, in São Paulo, Brazil, in November 2007. METHODS: We applied a questionnaire to orthopedists registered at the congress. The questionnaire was randomly distributed and participation was voluntary; 858 completed questionnaires were included in the analysis. RESULTS: Most of the Brazilian orthopedists were members of SBOT and worked in the southeastern region. They used imported cemented implants through an anterior access route centered on the patella, with replacement of the joint surface of the patella and preservation of the posterior cruciate ligament. They did not have experience with simultaneous bilateral TKA. Postoperatively, they used antibiotics and suction drains for 48 hours. There was no consensus regarding prophylaxis for venous thromboembolism or the frequency of the main complications. CONCLUSION: The majority of Brazilian orthopedists work in the southeastern region of the country and agree about the main aspects of the approaches towards TKA.CONTEXTO E OBJETIVO: A artroplastia total do joelho (ATJ) evoluiu sobremaneira desde os anos 70, com melhora dos implantes e do instrumental cirúrgico, tornando-se uma intervenção efetiva para o tratamento da artrose do joelho. Muitos estudos apresentam resultados clínicos e radiológicos satisfatórios superiores a 90% no acompanhamento acima de 10 anos. Apesar das evidências científicas sobre sua eficácia da ATJ, a sua abordagem apresenta controvérsias em alguns aspectos. O objetivo do estudo foi avaliar como o ortopedista brasileiro aborda a ATJ e os principais aspectos técnicos na realização deste procedimento. TIPO DE ESTUDO E LOCAL: Estudo transversal, realizado durante o 39º Congresso Brasileiro de Ortopedia e Traumatologia em São Paulo, Brasil, em novembro de 2007. MÉTODOS: Aplicamos um questionário aos ortopedistas inscritos no congresso. A distribuição foi aleatória com adesão voluntária. Foram incluídos 858 questionários para análise. RESULTADOS: A maioria dos Ortopedistas Brasileiros são membros da SBOT e atua na região sudeste. Usam o implante importado, cimentado, por via de acesso anterior centrada na patela, com substituição da superfície articular da patela e preservação do ligamento cruzado posterior e não tem experiência com a artroplastia total bilateral simultânea. No pós-operatório utilizam antibióticos e dreno de sucção por 48 horas. Não houve consenso quanto à profilaxia para tromboembolismo venoso e frequência das principais complicações. CONCLUSÃO: A maioria dos ortopedistas brasileiros trabalha na região sudeste e concorda quanto aos principais aspectos da abordagem da ATJ.Universidade Federal de São Paulo (UNIFESP) Department of Orthopedics and TraumatologyUniversidade Federal de São Paulo (UNIFESP) Department of Orthopedics and Traumatology Orthopedist and Head of the Knee GroupUNIFESP, Department of Orthopedics and TraumatologyUNIFESP, Department of Orthopedics and Traumatology Orthopedist and Head of the Knee GroupSciEL

Integrative Analysis of Epigenetic Modulation in Melanoma Cell Response to Decitabine: Clinical Implications

Decitabine, an epigenetic modifier that reactivates genes otherwise suppressed by DNA promoter methylation, is effective for some, but not all cancer patients, especially those with solid tumors. It is commonly recognized that to overcome resistance and improve outcome, treatment should be guided by tumor biology, which includes genotype, epigenotype, and gene expression profile. We therefore took an integrative approach to better understand melanoma cell response to clinically relevant dose of decitabine and identify complementary targets for combined therapy. We employed eight different melanoma cell strains, determined their growth, apoptotic and DNA damage responses to increasing doses of decitabine, and chose a low, clinically relevant drug dose to perform whole-genome differential gene expression, bioinformatic analysis, and protein validation studies. The data ruled out the DNA damage response, demonstrated the involvement of p21Cip1 in a p53-independent manner, identified the TGFβ pathway genes CLU and TGFBI as markers of sensitivity to decitabine and revealed an effect on histone modification as part of decitabine-induced gene expression. Mutation analysis and knockdown by siRNA implicated activated β-catenin/MITF, but not BRAF, NRAS or PTEN mutations as a source for resistance. The importance of protein stability predicted from the results was validated by the synergistic effect of Bortezomib, a proteasome inhibitor, in enhancing the growth arrest of decitabine in otherwise resistant melanoma cells. Our integrative analysis show that improved therapy can be achieved by comprehensive analysis of cancer cells, identified biomarkers for patient's selection and monitoring response, as well as targets for improved combination therapy