Microbial hydroxylation of progesterone with Acremonium strictum

Microbial hydroxylation of progesterone occurred in the culture of Acremonium strictum PTCC 5282 to produce two hydroxylated pregnene-like steroids. The metabolites were purified and characterized using spectroscopic methods and identified as 15alpha-hydroxyprogesterone and 15alpha-hydroxydeoxycorticosterone.     

Bioconversion of Hydrocortisone by Cyanobacterium Fischerella ambigua PTCC 1635

Summary The bioconversion of hydrocortisone by a locally isolated strain of cyanobacterium Fischerella ambigua PTCC 1635 was investigated. Fischerella ambigua had not been previously examined for this potential. The fermentation led to production of 11β,17α, 20β, 21-tetrahydroxypregn-4-en-3-one and 11β-hydroxyandrost-4-en-3,17-dione. The metabolites were isolated and purified by chromatographic methods and identified using instrumental analyses.     

Promoter methylation analysis of WNT/β-catenin pathway regulators and its association with expression of DNMT1 enzyme in colorectal cancer

Background

Aberrant DNA methylation as the most important reason making epigenetic silencing of genes is a main mechanism of gene inactivation in patients with colorectal cancer. In this study, we decided to identify promoter methylation status of ten genes encoding WNT negative regulators, and measure the expression of DNMT1 enzyme in colorectal cancer samples.

Results

Aberrant methylation of APC gene was statistically significant associated with age over 50 (p = 0.017), DDK3 with male (p < 0.0001), SFRP4, WIF1, and WNT5a with increasing tumor stage (p = 0.004, p = 0.029, and p = 0.004), SFRP4 and WIF1 with tumor differentiation (p = 0.009 and p = 0.031) and SFRP2 and SFRP5 with histological type (p = 0.001 and p = 0.025). The increasing number of methylated genes correlated with the expression levels of the DNMT1 mRNA.

Conclusions

The rate of gene promoter methylation of WNT pathway regulators is high in colorectal cancer cells. Hyper-methylation is associated with increased expression of the DNMT1 enzyme.     

Improvement in efficiency of microspore culture to produce doubled haploid lines of Ethiopian mustard

Factors affecting microspore embryogenesis of Ethiopian mustard (Brassica carinata A. Braun) were evaluated, including flower bud length, pollen developmental stage, and microspore density. An embryogenic frequency of 300 embryos per Petri plate was observed with NLN (Nitsch-Lichter-Nitsch) medium supplemented with 13% sucrose, 3.0–3.4-mm-long buds, and a plating density of 65,000 microspores/ml. About 65% of the microspores from buds 3.0–3.4-mm long were at the late uninucleate stage. Microspore-derived embryos were successfully transferred to solid medium for germination. After 4 wk, the resulting plantlets were transplanted to a soilless potting mixture and grew well under greenhouse conditions.     

Bone marrow microenvironment: The guardian of leukemia stem cells

Bone marrow microenvironment(BMM) is the main sanctuary of leukemic stem cells(LSCs) and protects these cells against conventional therapies. However, it may open up an opportunity to target LSCs by breaking the close connection between LSCs and the BMM. The elimination of LSCs is of high importance, since they follow cancer stem cell theory as a part of this population. Based on cancer stem cell theory, a cell with stem cell-like features stands at the apex of the hierarchy and produces a heterogeneous population and governs the disease.Secretion of cytokines, chemokines, and extracellular vesicles, whether through autocrine or paracrine mechanisms by activation of downstream signaling pathways in LSCs, favors their persistence and makes the BMM less hospitable for normal stem cells. While all details about the interactions of the BMM and LSCs remain to be elucidated, some clinical trials have been designed to limit these reciprocal interactions to cure leukemia more effectively. In this review, we focus on chronic myeloid leukemia and acute myeloid leukemia LSCs and their milieu in the bone marrow, how to segregate them from the normal compartment, and finally the possible ways to eliminate these cells.     

Combined detection and introgression of QTL in outbred populations

Background

Detecting a QTL is only the first step in genetic improvement programs. When a QTL with desirable characteristics is found, e.g. in a wild or unimproved population, it may be interesting to introgress the detected QTL into the commercial population. One approach to shorten the time needed for introgression is to combine both QTL identification and introgression, into a single step. This combines the strengths of fine mapping and backcrossing and paves the way for introgression of desirable but unknown QTL into recipient animal and plant lines.

Methods

The method consisting in combining QTL mapping and gene introgression has been extended from inbred to outbred populations in which QTL allele frequencies vary both in recipient and donor lines in different scenarios and for which polygenic effects are included in order to model background genes. The effectiveness of the combined QTL detection and introgression procedure was evaluated by simulation through four backcross generations.

Results

The allele substitution effect is underestimated when the favourable QTL allele is not fixed in the donor line. This underestimation is proportional to the frequency differences of the favourable QTL allele between the lines. In most scenarios, the estimates of the QTL location are unbiased and accurate. The retained donor chromosome segment and linkage drag are similar to expected values from other published studies.

Conclusions

In general, our results show that it is possible to combine QTL detection and introgression even in outbred species. Separating QTL mapping and introgression processes is often thought to be longer and more costly. However, using a combined process saves at least one generation. With respect to the linkage drag and obligatory drag, the results of the combined detection and introgression scheme are very similar to those of traditional introgression schemes.     

Localization and Functionality of the Inflammasome in Neutrophils

Neutrophils represent the major fraction of circulating immune cells and are rapidly recruited to sites of infection and inflammation. The inflammasome is a multiprotein complex that regulates the generation of IL-1 family proteins. The precise subcellular localization and functionality of the inflammasome in human neutrophils are poorly defined. Here we demonstrate that highly purified human neutrophils express key components of the NOD-like receptor family, pyrin domain containing 3 (NLRP3), and absent in melanoma 2 (AIM2) inflammasomes, particularly apoptosis-associated speck-like protein containing a CARD (ASC), AIM2, and caspase-1. Subcellular fractionation and microscopic analyses further showed that inflammasome components were localized in the cytoplasm and also noncanonically in secretory vesicle and tertiary granule compartments. Whereas IL-1β and IL-18 were expressed at the mRNA level and released as protein, highly purified neutrophils neither expressed nor released IL-1α at baseline or upon stimulation. Upon inflammasome activation, highly purified neutrophils released substantially lower levels of IL-1β protein compared with partially purified neutrophils. Serine proteases and caspases were differentially involved in IL-1β release, depending on the stimulus. Spontaneous activation of the NLRP3 inflammasome in neutrophils in vivo affected IL-1β, but not IL-18 release. In summary, these studies show that human neutrophils express key components of the inflammasome machinery in distinct intracellular compartments and release IL-1β and IL-18, but not IL-1α or IL-33 protein. Targeting the neutrophil inflammasome may represent a future therapeutic strategy to modulate neutrophilic inflammatory diseases, such as cystic fibrosis, rheumatoid arthritis, or sepsis.