Parasitic Cuscuta factor(s) and the detection by tomato initiates plant defense

Dodders (Cuscuta spp.) are holoparasitic plants that enwind stems of host plants and penetrate those by haustoria to connect to the vascular bundles. Having a broad host plant spectrum, Cuscuta spp infect nearly all dicot plants – only cultivated tomato as one exception is mounting an active defense specifically against C. reflexa. In a recent work we identified a pattern recognition receptor of tomato, “Cuscuta Receptor 1“ (CuRe1), which is critical to detect a “Cuscuta factor” (CuF) and initiate defense responses such as the production of ethylene or the generation of reactive oxygen species. CuRe1 also contributes to the tomato resistance against C. reflexa. Here we point to the fact that CuRe1 is not the only relevant component for full tomato resistance but it requires additional defense mechanisms, or receptors, respectively, to totally fend off the parasite

Cardioprotective Effects of Osteopontin-1 during Development of Murine Ischemic Cardiomyopathy

Repetitive brief ischemia and reperfusion (I/R) is associated with ventricular dysfunction in pathogenesis of murine ischemic cardiomyopathy and human hibernating myocardium. We investigated the role of matricellular protein osteopontin-1 (OPN) in murine model of repetitive I/R. One 15-min LAD-occlusion followed by reperfusion was performed daily over 3, 5, and 7 consecutive days in C57/Bl6 wildtype- (WT-) and OPN−/−-mice (n=8/group). After echocardiography hearts were processed for histological and mRNA-studies. Cardiac fibroblasts were isolated, cultured, and stimulated with TGF-β1. WT-mice showed an early, strong, and cardiomyocyte-specific osteopontin-expression leading to interstitial macrophage infiltration and consecutive fibrosis after 7 days I/R in absence of myocardial infarction. In contrast, OPN−/−-mice showed small, nontransmural infarctions after 3 days I/R associated with significantly worse ventricular dysfunction. OPN−/−-mice had different expression of myocardial contractile elements and antioxidative mediators and a lower expression of chemokines during I/R. OPN−/−-mice showed predominant collagen deposition in macrophage-rich small infarctions. We found lower induction of tenascin-C, MMP-9, MMP-12, and TIMP-1, whereas MMP-13-expression was higher in OPN−/−-mice. Cultured OPN−/−-myofibroblasts confirmed these findings. In conclusion, osteopontin seems to modulate expression of contractile elements, antioxidative mediators, and inflammatory response and subsequently remodel in order to protect cardiomyocytes in murine ischemic cardiomyopathy

Ações afirmativas e o debate sobre racismo no Brasil Afirmative actions and the debate on racism in Brazil

O tema "ações afirmativas" tem dividido a opinião pública e esquentado o debate acadêmico. Enquanto alguns especialistas e militantes negros entendem a introdução de ações afirmativas como uma forma de combate ao racismo, uma vez que, segundo esta interpretação, a discriminação positiva ajudará os historicamente desprivilegiados a criar e fortalecer uma identidade positiva, outros vêem em tais medidas um ataque perigoso contra a "maneira tradicional brasileira" de se relacionar com as "diferenças humanas" e temem que políticas como essas possam instigar conflitos raciais abertos. Embora os defensores e opositores à introdução de projetos de ação afirmativa raramente explicitem o que entendem por racismo e como interpretam este fenômeno social, é possível detectar nesses discursos distintas linhas de argumentação que remetem a orientações teóricas diferentes no que diz respeito à análise de categorias como "raça" e "cor".<br>The "affirmative action" issue has split the public opinion and heated up the academic debate. While some experts and black activists see the affirmatives actions as a way to fight racism, since the positive discrimination could help the historically underprivileged to create and empower a positive identity, others see such measures as a dangerous attack against the "traditional brazilian way" of dealing with "human differences". The latter fear that such policies may unleash racial conflicts. Although both sides barely explain what they mean for racism and how they understand that social phenomenon, it is possible to discern in those discourses different lines of argument, which can be related to different theoretical orientations about the analysis of such concepts as "race" and "color"