27 research outputs found
Integrated MicroRNA-mRNA-Analysis of Human Monocyte Derived Macrophages upon Mycobacterium avium subsp. hominissuis Infection
Many efforts have been made to understand basal mechanisms of mycobacterial infections. Macrophages are the first line of host immune defence to encounter and eradicate mycobacteria. Pathogenic species have evolved different mechanisms to evade host response, e.g. by influencing macrophage apoptotic pathways. However, the underlying molecular regulation is not fully understood. A new layer of eukaryotic regulation of gene expression is constituted by microRNAs. Therefore, we present a comprehensive study for identification of these key regulators and their targets in the context of host macrophage response to mycobacterial infections.We performed microRNA as well as mRNA expression analysis of human monocyte derived macrophages infected with several Mycobacterium avium hominissuis strains by means of microarrays as well as quantitative reverse transcription PCR (qRT-PCR). The data revealed the ability of all strains to inhibit apoptosis by transcriptional regulation of BCL2 family members. Accordingly, at 48 h after infection macrophages infected with all M. avium strains showed significantly decreased caspase 3 and 7 activities compared to the controls. Expression of let-7e, miR-29a and miR-886-5p were increased in response to mycobacterial infection at 48 h. The integrated analysis of microRNA and mRNA expression as well as target prediction pointed out regulative networks identifying caspase 3 and 7 as potential targets of let-7e and miR-29a, respectively. Consecutive reporter assays verified the regulation of caspase 3 and 7 by these microRNAs.We show for the first time that mycobacterial infection of human macrophages causes a specific microRNA response. We furthermore outlined a regulatory network of potential interactions between microRNAs and mRNAs. This study provides a theoretical concept for unveiling how distinct mycobacteria could manipulate host cell response. In addition, functional relevance was confirmed by uncovering the control of major caspases 3 and 7 by let-7e and miR-29a, respectively
Forest Ecosystem as a Source of Co2 During Growing Season: Relation to Weather Conditions
Net ecosystem production reflects the potential of
the ecosystem to sequestrate atmospheric CO2. Daily net ecosystem
production of a mountain Norway spruce forest of the temperate
zone (Czech Republic) was determined using the eddy covariance
method. Growing season days when the ecosystem was a CO2
source were examined with respect to current weather conditions.
During the 2005, 2006, and 2007 growing seasons, there were 44,
65, and 39 days, respectively, when the forest was a net CO2
source. The current weather conditions associated with CO2 release
during the growing seasons were: cool and overcast conditions
at the beginning or end of the growing seasons characterized
by a 3-year mean net ecosystem production of -7.2 kg C ha-1 day-1;
overcast or/and rainy days (-23.1 kg C ha-1 day-1); partly cloudy
and hot days (-11.8 kg C ha-1 day-1); and overcast and hot days
(-13.5 kg C ha-1 day-1). CO2 release was the highest during the
overcast or/and rainy conditions (84%, average from all years),
which had the greatest impact during the major production periods.
As forests are important CO2 sinks and more frequent weather
extremes are expected due to climate change, it is important to
predict future forest carbon balances to study the influence of
heightened variability in climatic variables
Forest ecosystem as a source of CO2 during growing season: relation to weather conditions
Net ecosystem production reflects the potential of
the ecosystem to sequestrate atmospheric CO2. Daily net ecosystem
production of a mountain Norway spruce forest of the temperate
zone (Czech Republic) was determined using the eddy covariance
method. Growing season days when the ecosystem was a CO2
source were examined with respect to current weather conditions.
During the 2005, 2006, and 2007 growing seasons, there were 44,
65, and 39 days, respectively, when the forest was a net CO2
source. The current weather conditions associated with CO2 release
during the growing seasons were: cool and overcast conditions
at the beginning or end of the growing seasons characterized
by a 3-year mean net ecosystem production of -7.2 kg C ha-1 day-1;
overcast or/and rainy days (-23.1 kg C ha-1 day-1); partly cloudy
and hot days (-11.8 kg C ha-1 day-1); and overcast and hot days
(-13.5 kg C ha-1 day-1). CO2 release was the highest during the
overcast or/and rainy conditions (84%, average from all years),
which had the greatest impact during the major production periods.
As forests are important CO2 sinks and more frequent weather
extremes are expected due to climate change, it is important to
predict future forest carbon balances to study the influence of
heightened variability in climatic variables
The effects of oxytocin and its analog, carbetocin, on genetic deficits in sensorimotor gating
Isolation and characterisation of Mycobacterium avium and Rhodococcus equi from granulomatous lesions of swine lymph nodes in Slovenia
Bis-naphthopyrone pigments protect filamentous ascomycetes from a wide range of predators
It is thought that fungi protect themselves from predation by the production of compounds
that are toxic to soil-dwelling animals. Here, we show that a nontoxic pigment, the bisnaphthopyrone
aurofusarin, protects Fusarium fungi from a wide range of animal predators.
We find that springtails (primitive hexapods), woodlice (crustaceans), and mealworms
(insects) prefer feeding on fungi with disrupted aurofusarin synthesis, and mealworms and
springtails are repelled by wheat flour amended with the fungal bis-naphthopyrones aurofusarin,
viomellein, or xanthomegnin. Predation stimulates aurofusarin synthesis in several
Fusarium species and viomellein synthesis in Aspergillus ochraceus. Aurofusarin displays low
toxicity in mealworms, springtails, isopods, Drosophila, and insect cells, contradicting
the common view that fungal defence metabolites are toxic. Our results indicate that bisnaphthopyrones
are defence compounds that protect filamentous ascomycetes from predators
through a mechanism that does not involve toxicity.National Natural Science Foundation of China/[21876152]//ChinaChina Scholarship Concil///ChinaMinistry for Science and Culture of Lower Saxony///GermanyGerman Academic Exchange Service///GermanyGerman Research Foundation/[DFG IRTG 2172]//GermanyUCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS