IL-6 Promotes compensatory liver regeneration in cirrhotic rat after partial hepatectomy

Major hepatic resection in cirrhotic patients is associated with impaired liver regeneration and failure, leading to high peri-operative mortality. In this work, the causes of defective regeneration in cirrhotic liver and the utility of IL-6 treatment were investigated in an experimental model combining cirrhosis and partial hepatectomy in the rat. Relative to normal controls, decompensated cirrhotic animals showed decreased survival, while compensated cirrhotic animals showed similar survival but reduced hepatic DNA synthesis and newly regenerated liver mass amount. Defective liver regeneration was associated with a decrease in STAT3 and NF-kB activation, consistent with an increased accumulation of their respective inhibitors PIAS3 and IkBα, and with a decreased induction of Bcl-xL. Treatment with recombinant IL-6 enhanced survival of decompensated cirrhotic animals, while it did not affect survival of compensated cirrhotic animals but sustained liver regeneration, by restoring STAT3 and NF-kB activation and Bcl-xL induction to the levels found in normal controls. The pro-growth effects exerted by IL-6 treatment in cirrhotic liver were attained also at low, pharmacologically acceptable doses. In conclusion, our results suggest that IL-6 treatment may be therapeutic in major resection of cirrhotic liver.     

S-100 protein in “follicular dendritic” cells of rat lymphoid organs

The presence as well as the cellular and subcellular distribution of S-100 protein were investigated in lymphoid organs of the adult rat by quantitative microcomplement fixation assay and by the immunocytochemical PAP method at the ultrastructural level. The protein appeared to be confined to the "follicular dendritic" cells both in the lymph node and the spleen, which are known to be exclusively associated with B lymphocytes in secondary follicles. The present data show an additional location for S-100 outside the nervous system. The protein may also be a useful tool to provide information on the origin and function of "follicular dendritic" cells, which are still poorly understood.     

Biosynthesis of isochorismate in Klebsiella pneumoniae: origin of O-2

The shikimate metabolites are key precursors to a large number of natural products, including aromatic amino acids. Chorismic acid is an important branch point in the biosynthetic pathway to aromatic amino acids. Chorismic acid is also unique among natural products since it is the only compound known to undergo an enzymatic Claisen rearrangement. A metabolite of chorismic acid, isochorismic acid, first observed in Aerobacter aerogenes differs in its chemical structure by the location of the hydroxyl group and the double bonds. Isochorismic acid is a precursor to a growing number of shikimate-derived metabolites. Isochorismic acid has also been postulated to be an intermediate of m-carboxyaromatic amino acids, implying another enzymatic Claisen rearrangement. In this publication, we have isolated isochorismate synthase and found that on lyophilization the enzyme is stable for at least 6 months at -20 degrees C. Incubation of chorismate with this preparation in water enriched with 18O led to incorporation of one atom of 18O as proven from the fast atom bombardment mass spectra of the HPLC purified derived isochorismate.     

Synthesis of chiral arogenic acid via immobilized microbial proteins

Although l-(8S)-arogenate has been recognized as a potential precursor of l-phenylalanine or l-tyrosine biosynthesis for only a few years, it is widely distributed in nature. The biochemical formation of arogenate has involved its isolation from the culture supernatant of a mutant strain of Neurospora crassa, a lengthy procedure of 20-day duration. We now report an improved approach using immobilized crude enzyme extracts from a cyanobacterium. The starting materials, chorismic acid or prephenic acid, are readily available, and overall yields ranging from 40 to 60% are obtained. The whole procedure takes only 1 day. Crude, unfractionated enzyme extracts from Synechocystis sp. ATCC 29108 are immobilized on a phenoxyacetyl cellulose solid support. The hydrophobic binding of the extract proteins did not denature chorismate mutase or prephenate aminotransferase, the enzymes catalyzing the conversion of chorismate to prephenate and prephenate to arogenate, respectively. This microbial system was ideally suited for preparation of arogenate, since other enzyme activities which might compete for prephenate or chorismate as substrates, or which might further metabolize arogenate, were absent or inactive under the conditions used. In addition to the substrates prephenate or chorismate, pyridoxal-5′-phosphate (the coenzyme required for transamination), as well as leucine (amino donor for transamination of prephenate), was added. The reaction product, arogenate, was separated from the starting materials by preparative thin-layer chromatography.     

Activation of Oncogenic Pathways in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. The most recent hypotheses on IPF pathogenesis suggest a central role of epithelial cell damage, followed by a dysregulated molecular cross talk between epithelial cells and fibroblasts. Thus, IPF progression has often been assimilated to that of cancer, and several signaling patterns appear to be disrupted in both diseases. Here, we analyze the expression in an IPF series of a panel of molecules, which are known to play a role in tumorigenic process. Our findings, although preliminary, reveal that IPF landscape is enriched in neoplastic potential expressed in a context of complex genomic polyclonality and cellular heterogeneity. These results provide a rationale for further investigations aimed to exploit—in a similar fashion to cancer—targeted therapies for a “precision medicine” approach to IPF.     

Knowledge of Malaria and Its Association with Malaria-Related Behaviors—Results from the Malaria Indicator Survey,Ethiopia, 2007

Background

In 2005, the Ministry of Health in Ethiopia launched a major effort to distribute over 20 million long-lasting insecticidal nets, provide universal access to artemisinin-based combination therapy (ACTs), and train 30,000 village-based health extension workers.

Methods and Findings

A cross-sectional, nationally representative Malaria Indicator Survey was conducted during the malaria transmission season in 2007. Multivariate logistic regression analyses were performed to assess the effect of women''s malaria knowledge on household ITN ownership and women''s ITN use. In addition, we investigated the effect of mothers'' malaria knowledge on their children under 5 years of age''s (U5) ITN use and their access to fever treatment on behalf of their child U5. Malaria knowledge was based on a composite index about the causes, symptoms, danger signs and prevention of malaria. Approximately 67% of women (n = 5,949) and mothers of children U5 (n = 3,447) reported some knowledge of malaria. Women''s knowledge of malaria was significantly associated with household ITN ownership (adjusted Odds Ratio [aOR] = 2.1; 95% confidence interval [CI] 1.6–2.7) and with increased ITN use for themselves (aOR = 1.8; 95% CI 1.3–2.5). Knowledge of malaria amongst mothers of children U5 was associated with ITN use for their children U5 (aOR = 1.6; 95% CI 1.1–2.4), but not significantly associated with their children U5 seeking care for a fever. School attendance was a significant factor in women''s ITN use (aOR = 2.0; 95% CI 1.1–3.9), their children U5′s ITN use (aOR = 4.4; 95% CI 1.6–12.1), and their children U5 having sought treatment for a fever (aOR = 6.5; 95% CI 1.9–22.9).

Conclusions

Along with mass free distribution of ITNs and universal access to ACTs, delivery of targeted malaria educational information to women could improve ITN ownership and use. Efforts to control malaria could be influenced by progress towards broader goals of improving access to education, especially for women.     

4-oxo-N-(4-hydroxyphenyl)retinamide: two independent ways to kill cancer cells

Background

The retinoid 4-oxo-N-(4-hydroxyphenyl)retinamide (4-oxo-4-HPR) is a polar metabolite of fenretinide (4-HPR) very effective in killing cancer cells of different histotypes, able to inhibit 4-HPR-resistant cell growth and to act synergistically in combination with the parent drug. Unlike 4-HPR and other retinoids, 4-oxo-4-HPR inhibits tubulin polymerization, leading to multipolar spindle formation and mitotic arrest. Here we investigated whether 4-oxo-4-HPR, like 4-HPR, triggered cell death also via reactive oxygen species (ROS) generation and whether its antimicrotubule activity was related to a ROS-dependent mechanism in ovarian (A2780), breast (T47D), cervical (HeLa) and neuroblastoma (SK-N-BE) cancer cell lines.

Methodology/Principal Findings

We provided evidence that 4-oxo-4-HPR, besides acting as an antimicrotubule agent, induced apoptosis through a signaling cascade starting from ROS generation and involving endoplasmic reticulum (ER) stress response, Jun N-terminal Kinase (JNK) activation, and upregulation of the proapoptotic PLAcental Bone morphogenetic protein (PLAB). Through time-course analysis and inhibition of the ROS-related signaling pathway (upstream by vitamin C and downstream by PLAB silencing), we demonstrated that the antimitotic activity of 4-oxo-4-HPR was independent from the oxidative stress induced by the retinoid. In fact, ROS generation occurred earlier than mitotic arrest (within 30 minutes and 2 hours, respectively) and abrogation of the ROS-related signaling pathway did not prevent the 4-oxo-4-HPR-induced mitotic arrest.

Conclusions/Significance

These data indicate that 4-oxo-4-HPR anticancer activity is due to at least two independent mechanisms and provide an explanation of the ability of 4-oxo-4-HPR to be more potent than the parent drug and to be effective also in 4-HPR-resistant cell lines. In addition, the double mechanism of action could allow 4-oxo-4-HPR to efficiently target tumour and to eventually counteract the development of drug resistance.     

In situ assessment of oxidant and nitrogenic stress in bleomycin pulmonary fibrosis

Reactive oxygen species (ROS) and nitric oxide (NO) have a role in the development of pulmonary fibrosis after bleomycin administration. The ROS production induces an antioxidant response, involving superoxide dismutases (SODs), catalase, and glutathione peroxidases. We compared in situ oxidative burden and antioxidant enzyme activity in bleomycin-injured rat lungs and normal controls. ROS expression and catalase, glucose-6-phosphate-dehydrogenase (G6PHD), and NOS/NADPH-diaphorase activity were investigated by using histochemical reactions. Nitric oxide synthase (e-NOS and i-NOS) and SOD (MnSOD, Cu/ZnSOD, ECSOD) expression was investigated immunohistochemically. After treatment ROS production was enhanced in both phagocytes and in type II alveolar epithelial cells. Mn, Cu/Zn, and ECSOD were overexpressed in parenchymal cells, whereas interstitium expressed ECSOD. Catalase and G6PHD activity was moderately increased in parenchymal and inflammatory cells. NOS/NADPH-d activity and i-NOS expression increased in alveolar and bronchiolar epithelia and in inflammatory cells. It can be suggested that the concomitant activation of antioxidant enzymes is not adequate to scavenge the oxidant burden induced by bleomycin lung damage. Inflammatory cells and also epithelial cells are responsible of ROS and NO production. This oxidative and nitrosative stress may be a substantial trigger in TGF-β1 overexpression by activated type II pneumocytes, leading to fibrotic lesions.     

The Decrease of Mineralcorticoid Receptor Drives Angiogenic Pathways in Colorectal Cancer

Angiogenesis plays a crucial role in tumor growth and progression. Low expression of mineralocorticoid receptor (MR) in several malignant tumors correlates with disease recurrence and overall survival. Previous studies have shown that MR expression is decreased in colorectal cancer (CRC). Here we hypothesize that decreased MR expression can contribute to angiogenesis and poor patient survival in colorectal malignancies. In a cohort of CRC patients, we analyzed tumor MR expression, its correlation with tumor microvascular density and its impact on survival. Subsequently, we interrogated the role of MR in angiogenesis in an in vitro model, based on the colon cancer cell line HCT116, ingenierized to re-express a physiologically controlled MR. In CRC, decreased MR expression was associated with increased microvascular density and poor patient survival. In pchMR transfected HCT116, aldosterone or natural serum steroids largely inhibited mRNA expression levels of both VEGFA and its receptor 2/KDR. In CRC, MR activation may significantly decrease angiogenesis by directly inhibiting dysregulated VEGFA and hypoxia-induced VEGFA mRNA expression. In addition, MR activation attenuates the expression of the VEGF receptor 2/KDR, possibly dampening the activation of a VEGFA/KDR dependent signaling pathway important for the survival of tumor cells under hypoxic conditions.