Kaposi's Sarcoma Associated Herpes Virus (KSHV) Induced COX-2: A Key Factor in Latency, Inflammation, Angiogenesis, Cell Survival and Invasion

Kaposi's sarcoma (KS), an enigmatic endothelial cell vascular neoplasm, is characterized by the proliferation of spindle shaped endothelial cells, inflammatory cytokines (ICs), growth factors (GFs) and angiogenic factors. KSHV is etiologically linked to KS and expresses its latent genes in KS lesion endothelial cells. Primary infection of human micro vascular endothelial cells (HMVEC-d) results in the establishment of latent infection and reprogramming of host genes, and cyclooxygenase-2 (COX-2) is one of the highly up-regulated genes. Our previous study suggested a role for COX-2 in the establishment and maintenance of KSHV latency. Here, we examined the role of COX-2 in the induction of ICs, GFs, angiogenesis and invasive events occurring during KSHV de novo infection of endothelial cells. A significant amount of COX-2 was detected in KS tissue sections. Telomerase-immortalized human umbilical vein endothelial cells supporting KSHV stable latency (TIVE-LTC) expressed elevated levels of functional COX-2 and microsomal PGE2 synthase (m-PGES), and secreted the predominant eicosanoid inflammatory metabolite PGE2. Infected HMVEC-d and TIVE-LTC cells secreted a variety of ICs, GFs, angiogenic factors and matrix metalloproteinases (MMPs), which were significantly abrogated by COX-2 inhibition either by chemical inhibitors or by siRNA. The ability of these factors to induce tube formation of uninfected endothelial cells was also inhibited. PGE2, secreted early during KSHV infection, profoundly increased the adhesion of uninfected endothelial cells to fibronectin by activating the small G protein Rac1. COX-2 inhibition considerably reduced KSHV latent ORF73 gene expression and survival of TIVE-LTC cells. Collectively, these studies underscore the pivotal role of KSHV induced COX-2/PGE2 in creating KS lesion like microenvironment during de novo infection. Since COX-2 plays multiple roles in KSHV latent gene expression, which themselves are powerful mediators of cytokine induction, anti-apoptosis, cell survival and viral genome maintainence, effective inhibition of COX-2 via well-characterized clinically approved COX-2 inhibitors could potentially be used in treatment to control latent KSHV infection and ameliorate KS

Tabaco na mídia: análise de matérias jornalísticas no ano de 2006 Tobacco in the media: analysis of journalistic texts in the year of 2006

Visando compreender a relação entre saúde, imprensa e políticas públicas sobre tabaco no Brasil, foram analisadas matérias sobre tabaco divulgadas na imprensa brasileira no ano de 2006. Através de clipping jornalístico de oito principais jornais e revistas do país, as matérias sobre tabaco foram identificadas e posteriormente submetidas à análise de conteúdo, que permitiu categorização e classificação dos textos. A frequência de matérias de 2006 foi comparada aos anos de 2000 e 2003. Foi observado predomínio de matérias com abordagem factual (46,7%). A maioria das matérias fez menção a consequências negativas, como problemas de saúde física (44,2%), morte (20%) e dependência (14,2%). Na análise das manchetes e lides, as principais categorias observadas foram políticas de controle e o movimentos antitabagistas e divulgação de pesquisas. A frequência de matérias de 2006 (N=120) foi semelhante ao ano de 2003 (N=124) e inferior a 2000 (N=174). A cobertura jornalística sobre tabaco em 2006 foi predominantemente restrita aos danos a saúde e ações antitabagistas. A elevada proporção de abordagem factual e a estabilização da frequência de matérias (2003-2006) podem indicar um empobrecimento na discussão sobre o tema no país.<br>Aiming at understanding the relation among health, press and public policies on Tobacco in Brazil, this article analyses the texts about Tobacco published in the Brazilian press in 2006. In the clipping process of eight newspapers and magazines, the information about Tobacco were identified and then submitted to content analysis allowing categorization and classification of the texts. The frequency of the texts in 2006 was compared to that of in 2000 and 2003. We observed a higher prevalence of factual approach among the texts (46.7%). Most of the texts mentioned the negative consequences, such as physical health problems (44.2%), death (20%) and dependence (14.2%). The analysis of the headlines and lead-ins showed control policies, anti-smoking movements and spreading of results as the main categories observed. The frequency of the articles in 2006 was similar to that of in 2003 and lower to that of in 2000. The journalistic coverage on Tobacco in 2006 was restricted predominantly to harm to health and anti-smoking movements. The high proportion of the factual approach and the stabilization in the frequency of texts (2003-2006) might suggest an impoverishment of the discussion on this issue in the country

The sodium chloride cotransporter SLC12A3: new roles in sodium, potassium, and blood pressure regulation

SLC12A3 encodes the thiazide-sensitive sodium chloride cotransporter (NCC), which is primarily expressed in the kidney, but also in intestine and bone. In the kidney, NCC is located in the apical plasma membrane of epithelial cells in the distal convoluted tubule. Although NCC reabsorbs only 5 to 10 % of filtered sodium, it is important for the fine-tuning of renal sodium excretion in response to various hormonal and non-hormonal stimuli. Several new roles for NCC in the regulation of sodium, potassium, and blood pressure have been unraveled recently. For example, the recent discoveries that NCC is activated by angiotensin II but inhibited by dietary potassium shed light on how the kidney handles sodium during hypovolemia (high angiotensin II) and hyperkalemia. The additive effect of angiotensin II and aldosterone maximizes sodium reabsorption during hypovolemia, whereas the inhibitory effect of potassium on NCC increases delivery of sodium to the potassium-secreting portion of the nephron. In addition, great steps have been made in unraveling the molecular machinery that controls NCC. This complex network consists of kinases and ubiquitinases, including WNKs, SGK1, SPAK, Nedd4-2, Cullin-3, and Kelch-like 3. The pathophysiological significance of this network is illustrated by the fact that modification of each individual protein in the network changes NCC activity and results in salt-dependent hypotension or hypertension. This review aims to summarize these new insights in an integrated manner while identifying unanswered questions

Adeno-associated virus inverted terminal repeats stimulate gene editing

Advancements in genome editing have relied on technologies to specifically damage DNA which, in turn, stimulates DNA repair including homologous recombination (HR). As off-target concerns complicate the therapeutic translation of site-specific DNA endonucleases, an alternative strategy to stimulate gene editing based on fragile DNA was investigated. To do this, an episomal gene-editing reporter was generated by a disruptive insertion of the adeno-associated virus (AAV) inverted terminal repeat (ITR) into the egfp gene. Compared with a non-structured DNA control sequence, the ITR induced DNA damage as evidenced by increased gamma-H2AX and Mre11 foci formation. As local DNA damage stimulates HR, ITR-mediated gene editing was investigated using DNA oligonucleotides as repair substrates. The AAV ITR stimulated gene editing >1000-fold in a replication-independent manner and was not biased by the polarity of the repair oligonucleotide. Analysis of additional human DNA sequences demonstrated stimulation of gene editing to varying degrees. In particular, inverted yet not direct, Alu repeats induced gene editing, suggesting a role for DNA structure in the repair event. Collectively, the results demonstrate that inverted DNA repeats stimulate gene editing via double-strand break repair in an episomal context and allude to efficient gene editing of the human chromosome using fragile DNA sequences