Effects of PM10 in human peripheral blood monocytes and J774 macrophages

Background

Asthma is characterized by type 2 T-helper cell (Th2) inflammation, goblet cell hyperplasia, airway hyperreactivity, and airway fibrosis. Monocyte chemoattractant protein-1 (MCP-1 or CCL2) and its receptor, CCR2, have been shown to play important roles in the development of Th2 inflammation. CCR2-deficient mice have been found to have altered inflammatory and physiologic responses in some models of experimental allergic asthma, but the role of CCR2 in contributing to inflammation and airway hyperreactivity appears to vary considerably between models. Furthermore, MCP-1-deficient mice have not previously been studied in models of experimental allergic asthma.

Methods

To test whether MCP-1 and CCR2 are each required for the development of experimental allergic asthma, we applied an Aspergillus antigen-induced model of Th2 cytokine-driven allergic asthma associated with airway fibrosis to mice deficient in either MCP-1 or CCR2. Previous studies with live Aspergillus conidia instilled into the lung revealed that MCP-1 and CCR2 play a role in anti-fungal responses; in contrast, we used a non-viable Aspergillus antigen preparation known to induce a robust eosinophilic inflammatory response.

Results

We found that wild-type C57BL/6 mice developed eosinophilic airway inflammation, goblet cell hyperplasia, airway hyperreactivity, elevations in serum IgE, and airway fibrosis in response to airway challenge with Aspergillus antigen. Surprisingly, mice deficient in either MCP-1 or CCR2 had responses to Aspergillus antigen similar to those seen in wild-type mice, including production of Th2 cytokines.

Conclusion

We conclude that robust Th2-mediated lung pathology can occur even in the complete absence of MCP-1 or CCR2.     

An edit script for taxonomic classifications

Background  

The NCBI taxonomy provides one of the most powerful ways to navigate sequence data bases but currently users are forced to formulate queries according to a single taxonomic classification. Given that there is not universal agreement on the classification of organisms, providing a single classification places constraints on the questions biologists can ask. However, maintaining multiple classifications is burdensome in the face of a constantly growing NCBI classification.     

Neuroendocrine regulation of thymus hormones: hypothalamic dependence of "facteur thymique serique" level

The influence of the hypothalamus extract (HE) on the blood level of the "facteur thymique serique" (FTS) was studied. Hypothalami collected from young mice were pooled, homogenated in saline, and centrifuged; finally, the supernatant injected in old or thymectomized mice with no detectable levels of FTS. In the old mice the treatment results in a reappearance of this circulating thymic hormone; in contrast, in adult thymectomized animals, the HE injection was not able to induce FTS activity. When HE donors were pretreated with thymosin fraction 3, known to contain FTS among other active peptides, the capacity of such a hypothalamus preparation to induce reappearance of FTS in old animals is greatly diminished. The data presented here suggest that the capacity of the thymus to secrete FTS depends on a hypothalamic factor, and therefore the absence of this thymic hormone in the aged reflects a failure of the thymus linked to its impaired neurologic control. On the other hand it seems evident that a feedback system operates in order to regulate the release of this hypothalamus stimulatory factor.     

Evidence of repetitive patterns of chromatin distribution in cell nuclei of rat liver

Samples of rat livers were fixed in glutaraldehyde, contrasted en bloc with phosphotungstic acid, embedded in an epoxy resin and serially sectioned. The study of three-dimensional models of 20 complete nuclei shows that all of them share some general features: they have more than one nucleolus (2-4), an irregular layer of compact chromatin adjacent to the nuclear membrane and well-delimited clumps of chromatin both in the nuclear sap and surrounding the nucleoli. A space of 8 sections containing the central nucleolus and a lateral one was studied in detail. In this space, 8 clumps of compact chromatin were found in 17 nuclei and 9 clumps in the other 3 nuclei. No other number of clumps was found in those zones. In all the nuclei studied the compact chromatin surrounding the central nucleolus contacts the nuclear envelope. This contact takes place in a region almost diametrically opposed to the lateral nucleolus in 13 nuclei. In 7 nuclei, these structures were at angles between 50 and 125 degrees. These results support the existence of nonrandom repetitive patterns of chromatin distribution in liver cells.     

Absolute configuration of the diterpenoids icetexone and conacytone from Salvia ballotaeflora

Detailed literature inspections regarding the diterpenoids icetexone ( 1 ) and conacytone ( 3 ) reveal that the absolute configuration (AC) of these natural occurring compounds is not rigorously proven, despite they were originally isolated in 1976. This task is now completed by single‐crystal X‐ray diffraction Flack and Hooft parameters determination after processing data collected with Cu Kα graphite monochromated radiation. The AC of both compounds is further determined by vibrational circular dichroism measurements performed on icetexone acetate ( 2 ) and conacytone triacetate ( 4 ) since the solubility of 1 and 3 is limited. Comparison of the substituent chemical shifts (SCS) induced by acetylation of 1 and 3 to afford 2 and 4 , respectively, reveals that in the case of icetexone, all six SCS values of the quinone ring are in excellent agreement with the expected values, while in the case of conacytone, three agree and three do not agree due to the presence of additional acetates near the quinone ring. Density functional theory calculations performed on 3‐hydroxythymoquinone ( 6 ) and its tautomer 4‐hydroxy‐1,2‐quinone 7 , on 6‐hydroxythymoquinone ( 8 ) and its tautomer ortho‐quinone 9 , and on icetexone ( 1 ) and the claimed natural occurring ortho‐quinone tautomer romulogarzone ( 5 ) indicate that 2‐hydroxy‐1,4‐quinones are more stable, by some 11‐14 kcal/mol, than their 4‐hydroxy‐1,2‐quinone tautomers, and therefore, romulogarzone ( 5 ) is inexistent.     

TBMap: a taxonomic perspective on the phylogenetic database TreeBASE

Background  

TreeBASE is currently the only available large-scale database of published organismal phylogenies. Its utility is hampered by a lack of taxonomic consistency, both within the database, and with names of organisms in external genomic, specimen, and taxonomic databases. The extent to which the phylogenetic knowledge in TreeBASE becomes integrated with these other sources is limited by this lack of consistency.     

Autophagy inhibition enhances vorinostat‐induced apoptosis via ubiquitinated protein accumulation

Autophagy is an evolutionarily conserved cell survival pathway that enables cells to recoup ATP and other critical biosynthetic molecules during nutrient deprivation or exposure to hypoxia, which are hallmarks of the tumour microenvironment. Autophagy has been implicated as a potential mechanism of resistance to anticancer agents as it can promote cell survival in the face of stress induced by chemotherapeutic agents by breaking down cellular components to generate alternative sources of energy. Disruption of autophagy with chloroquine (CQ) induces the accumulation of ubiquitin‐conjugated proteins in a manner similar to the proteasome inhibitor bortezomib (BZ). However, CQ‐induced protein accumulation occurs at a slower rate and is localized to lysosomes in contrast to BZ, which stimulates rapid buildup of ubiquitinated proteins and aggresome formation in the cytosol. The histone deacetylase (HDAC) inhibitor vorinostat (VOR) blocked BZ‐induced aggresome formation, but promoted CQ‐mediated ubiquitinated protein accumulation. Disruption of autophagy with CQ strongly enhanced VOR‐mediated apoptosis in colon cancer cells. Accordingly, knockdown of the essential autophagy gene Atg7 also sensitized cells to VOR‐induced apoptosis. Knockdown of HDAC6 greatly enhanced BZ‐induced apoptosis, but only marginally sensitized cells to CQ. Subsequent studies determined that the CQ/VOR combination promoted a large increase in superoxide generation that was required for ubiquitinated protein accumulation and cell death. Finally, treatment with the CQ/VOR combination significantly reduced tumour burden and induced apoptosis in a colon cancer xenograft model. Collectively, our results establish that inhibition of autophagy with CQ induces ubiquitinated protein accumulation and VOR potentiates CQ‐mediated aggregate formation, superoxide generation and apoptosis.