The CXCL12γ Chemokine Displays Unprecedented Structural and Functional Properties that Make It a Paradigm of Chemoattractant Proteins

The CXCL12γ chemokine arises by alternative splicing from Cxcl12, an essential gene during development. This protein binds CXCR4 and displays an exceptional degree of conservation (99%) in mammals. CXCL12γ is formed by a protein core shared by all CXCL12 isoforms, extended by a highly cationic carboxy-terminal (C-ter) domain that encompass four overlapped BBXB heparan sulfate (HS)-binding motifs. We hypothesize that this unusual domain could critically determine the biological properties of CXCL12γ through its interaction to, and regulation by extracellular glycosaminoglycans (GAG) and HS in particular. By both RT-PCR and immunohistochemistry, we mapped the localization of CXCL12γ both in mouse and human tissues, where it showed discrete differential expression. As an unprecedented feature among chemokines, the secreted CXCL12γ strongly interacted with cell membrane GAG, thus remaining mostly adsorbed on the plasmatic membrane upon secretion. Affinity chromatography and surface plasmon resonance allowed us to determine for CXCL12γ one of the higher affinity for HS (Kd = 0.9 nM) ever reported for a protein. This property relies in the presence of four canonical HS-binding sites located at the C-ter domain but requires the collaboration of a HS-binding site located in the core of the protein. Interestingly, and despite reduced agonist potency on CXCR4, the sustained binding of CXCL12γ to HS enabled it to promote in vivo intraperitoneal leukocyte accumulation and angiogenesis in matrigel plugs with much higher efficiency than CXCL12α. In good agreement, mutant CXCL12γ chemokines selectively devoid of HS-binding capacity failed to promote in vivo significant cell recruitment. We conclude that CXCL12γ features unique structural and functional properties among chemokines which rely on the presence of a distinctive C-ter domain. The unsurpassed capacity to bind to HS on the extracellular matrix would make CXCL12γ the paradigm of haptotactic proteins, which regulate essential homeostatic functions by promoting directional migration and selective tissue homing of cells

Inclusion of MUC1 (Ma695) in a panel of immunohistochemical markers is useful for distinguishing between endocervical and endometrial mucinous adenocarcinoma*

BACKGROUND: Distinguishing endocervical adenocarcinoma (ECA) from endometrial mucinous adenocarcinoma (EMMA) is clinically significant in view of the differences in their management and prognosis. In this study, we used a panel of tumor markers to determine their ability to distinguish between primary endocervical adenocarcinoma and primary endometrial mucinous adenocarcinoma. METHODS: Immunohistochemistry using monoclonal antibodies to MUC1 (Ma695), p16, estrogen receptor (ER), progesterone receptor (PR), and vimentin, was performed to examine 32 cases, including 18 EMMAs and 14 ECAs. For MUC1, cases were scored based on the percentage of staining pattern, apical, apical and cytoplasmic (A/C), or negative. For p16, cases were scored based on the percentage of cells stained. For the rest of the antibodies, semiquantitative scoring system was carried out. RESULTS: For MUC1, majority of EMMA (14 of 18 cases, 78%) showed A/C staining, whereas only few ECA (2 of 14, 14%) were positive. The difference of MUC1 expression in the two groups of malignancy was statistically significant (p < 0.001). Staining for p16 was positive in 10 of 14 (71%) ECA and 4 of 18 (22%) EMMA. Estrogen receptor was positive in 3 of 14 (21%) ECA and 17 of 18 (94%) EMMA. Progesterone receptor was positive in 3 of 14 (21%) ECA and 16 of 18 (89%) EMMA. Vimentin was positive in 1 of 14 (7%) ECA, and 9 of 18 (50%) EMA, with median and range of 0 (0–6), and 1.5 (0–9) respectively. CONCLUSION: A panel of immunohistochemical markers including MUC1, p16, ER, PR, and vimentin is recommended, when there is morphological and clinical doubt as to the primary site of endocervical or endometrial origin

Modulatory effects of heparin and short-length oligosaccharides of heparin on the metastasis and growth of LMD MDA-MB 231 breast cancer cells in vivo

Expression of the chemokine receptor CXCR4 allows breast cancer cells to migrate towards specific metastatic target sites which constitutively express CXCL12. In this study, we determined whether this interaction could be disrupted using short-chain length heparin oligosaccharides. Radioligand competition binding assays were performed using a range of heparin oligosaccharides to compete with polymeric heparin or heparan sulphate binding to I125 CXCL12. Heparin dodecasaccharides were found to be the minimal chain length required to efficiently bind CXCL12 (71% inhibition; P<0.001). These oligosaccharides also significantly inhibited CXCL12-induced migration of CXCR4-expressing LMD MDA-MB 231 breast cancer cells. In addition, heparin dodecasaccharides were found to have less anticoagulant activity than either a smaller quantity of polymeric heparin or a similar amount of the low molecular weight heparin pharmaceutical product, Tinzaparin. When given subcutaneously in a SCID mouse model of human breast cancer, heparin dodecasaccharides had no effect on the number of lung metastases, but did however inhibit (P<0.05) tumour growth (lesion area) compared to control groups. In contrast, polymeric heparin significantly inhibited both the number (P<0.001) and area of metastases, suggesting a differing mechanism for the action of polymeric and heparin-derived oligosaccharides in the inhibition of tumour growth and metastases

Nurses' workload and its relation with physiological stress reactions

OBJECTIVE: to analyze the relation between the workload and the physiological stress reactions among nurses working at a hospital service. METHODS: cross-sectional, correlational, quantitative study, involving 95 nurses, in 2011 and 2012. Spearman's bivariate Correlation Test was used. RESULTS: most subjects are female, between 23 and 61 years old and working between 21 and 78 hours per week. The most frequent physiological reactions were back pain, fatigue/exhaustion, stiff neck and stomach acidity, with 46.3% of the subjects presenting low and 42.1% moderate physiological stress responses. No correlation was found between the workload and the physiological stress responses. CONCLUSION: although most of the nurses work more than 36 hours/week, physiologically, they do not present high reaction levels in response to stress. These workers deal with conflicts in the vertical and horizontal relations between professionals, family members and patients. In that sense, taking care of professionals who offer health services can be a fundamental strategy, as good user care mainly depends on healthy teams.OBJETIVO: analisar a relação entre a carga horária de trabalho e as reações fisiológicas do estresse, entre enfermeiros de unidade hospitalar. MÉTODOS: estudo transversal, correlacional, quantitativo, realizado com 95 enfermeiros em 2011 e 2012. De forma bivariada, utilizou-se o teste de correlação de Spearman. RESULTADOS: a maioria dos sujeitos pertencia ao sexo feminino, faixa etária entre 23 e 61 anos, trabalhando de 21 a 78 horas semanais. As reações fisiológicas mais frequentes foram dores lombares, fadiga/exaustão, rigidez no pescoço e acidez estomacal, sendo que 46,3% dos sujeitos apresentaram baixas respostas fisiológicas ao estresse e moderadas em 42,1%. Não houve correlação entre a carga horária de trabalho e as reações fisiológicas do estresse. CONCLUSÃO: embora a maioria dos enfermeiros exercesse suas funções por mais de 36 horas/semana, fisiologicamente não apresentavam reações elevadas de resposta ao estresse. Tais trabalhadores lidavam com conflitos nas relações verticais e horizontais entre profissionais, familiares e pacientes. Nesse sentido, cuidar de profissionais que oferecem serviços de saúde pode ser estratégia fundamental, uma vez que bons atendimentos aos usuários dependem, principalmente, de equipes saudáveis.OBJETIVO: analizar la relación entre la carga horaria de trabajo y las reacciones fisiológicas de estrés entre enfermeros de servicio hospitalario. MÉTODOS: estudio trasversal, correlacional, cuantitativo, desarrollado con 95 enfermeros en 2011 y 2012. De forma bivariada, fue utilizada la Prueba de Correlación de Spearman. RESULTADOS: la mayoría de los sujetos es del sexo femenino, rango de edad entre 23 y 61 años y trabaja de 21 a 78 horas semanales. Las reacciones fisiológicas más frecuentes fueron dolores de espalda, fatiga/agotamiento, rigidez en el cuello y acidez estomacal, siendo que 46,3% de los sujetos revelaron bajas respuestas fisiológicas al estrés y moderadas en 42,1%. No fue encontrada correlación entre la carga horaria de trabajo y las reacciones fisiológicas del estrés. CONCLUSIÓN: aunque la mayoría de los enfermeros ejerza su función por más de 36 horas/semana, fisiológicamente no muestran reacciones elevadas de respuesta al estrés. Tales trabajadores lidian con conflictos en las reacciones verticales y horizontales entre profesionales, familiares y pacientes. En ese sentido, cuidar de profesionales que ofrecen servicios de salud puede ser estrategia fundamental, ya que buena atención a los usuarios depende principalmente de equipos saludables

Terapia comunitária integrativa: situações de sofrimento emocional e estratégias de enfrentamento apresentadas por usuários

A Terapia Comunitária Integrativa (TCI) surge como uma estratégia de apoio à saúde mental dos usuários do Sistema Único de Saúde. O estudo tem como objetivo identificar os principais problemas apresentados pelos usuários da terapia comunitária e identificar as estratégias que utilizam no enfrentamento das situações que provocam sofrimento emocional. Pesquisa do tipo documental realizada na Secretaria Municipal de Saúde, tendo como fontes de informações fichas de organização de dados da TCI. Os resultados demonstraram que o problema mais frequente é o estresse, que a estratégia de enfrentamento mais utilizada é a espiritualidade, e que através dos discursos dos participantes é possível perceber a opinião positiva que eles têm dos encontros. A TCI é um espaço onde as relações construídas transmitem apoio emocional, fortalecem vínculos e diminuem os casos de exclusão social

Heparan sulfate/heparin oligosaccharides protect stromal cell-derived factor-1 (SDF-1)/CXCL12 against proteolysis induced by CD26/dipeptidyl peptidase IV.

International audienceStromal cell-derived factor-1 (SDF-1) is a CXC chemokine that is constitutively expressed in most tissues and displayed on the cell surface in association with heparan sulfate (HS). Its numerous biological effects are mediated by a specific G protein-coupled receptor, CXCR4. A number of cells inactivate SDF-1 by specific processing of the N-terminal domain of the chemokine. In particular, CD26/dipeptidyl peptidase IV (DPP IV), a serine protease that co-distributes with CXCR4 at the cell surface, mediates the selective removal of the N-terminal dipeptide of SDF-1. We report here that heparin and HS specifically prevent the processing of SDF-1 by DPP IV expressed by Caco-2 cells. The level of processing increases with the level of differentiation of these cells, which correlates with an increase of DPP IV activity. A mutant SDF-1 that does not interact with HS is readily cleaved by DPP IV, a process that is not inhibited by HS, demonstrating that a productive interaction between HS and SDF-1 is required for the protection to take place. Moreover, we found that protection depends on the degree of polymerization of the HS sulfated S-domains. Finally a structural model of SDF-1, in complex with HS oligosaccharides of defined length, rationalizes the experimental data. The mechanisms by which HS regulates SDF-1 may thus include, in addition to its ability to locally concentrate the chemokine at the cell surface, a control of selective protease cleavage events that directly affect the chemokine activity