Omega-3 PUFAs prevent bone impairment and bone marrow adiposity in mouse model of obesity

Obesity adversely affects bone and fat metabolism in mice and humans. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) have been shown to improve glucose metabolism and bone homeostasis in obesity. However, the impact of omega-3 PUFAs on bone marrow adipose tissue (BMAT) and bone marrow stromal cell (BMSC) metabolism has not been intensively studied yet. In the present study we demonstrated that omega-3 PUFA supplementation in high fat diet (HFD + F) improved bone parameters, mechanical properties along with decreased BMAT in obese mice when compared to the HFD group. Primary BMSCs isolated from HFD + F mice showed decreased adipocyte and higher osteoblast differentiation with lower senescent phenotype along with decreased osteoclast formation suggesting improved bone marrow microenvironment promoting bone formation in mice. Thus, our study highlights the beneficial effects of omega-3 PUFA-enriched diet on bone and cellular metabolism and its potential use in the treatment of metabolic bone diseases.

Large-Scale Phylogenetic Analysis of Trypanosomatid Adenylate Cyclases Reveals Associations with Extracellular Lifestyle and Host-Pathogen Interplay

Receptor adenylate cyclases (RACs) on the surface of trypanosomatids are important players in the host–parasite interface. They detect still unidentified environmental signals that affect the parasites’ responses to host immune challenge, coordination of social motility, and regulation of cell division. A lesser known class of oxygen-sensing adenylate cyclases (OACs) related to RACs has been lost in trypanosomes and expanded mostly in Leishmania species and related insect-dwelling trypanosomatids. In this work, we have undertaken a large-scale phylogenetic analysis of both classes of adenylate cyclases (ACs) in trypanosomatids and the free-living Bodo saltans. We observe that the expanded RAC repertoire in trypanosomatids with a two-host life cycle is not only associated with an extracellular lifestyle within the vertebrate host, but also with a complex path through the insect vector involving several life cycle stages. In Trypanosoma brucei, RACs are split into two major clades, which significantly differ in their expression profiles in the mammalian host and the insect vector. RACs of the closely related Trypanosoma congolense are intermingled within these two clades, supporting early RAC diversification. Subspecies of T. brucei that have lost the capacity to infect insects exhibit high numbers of pseudogenized RACs, suggesting many of these proteins have become redundant upon the acquisition of a single-host life cycle. OACs appear to be an innovation occurring after the expansion of RACs in trypanosomatids. Endosymbiont-harboring trypanosomatids exhibit a diversification of OACs, whereas these proteins are pseudogenized in Leishmania subgenus Viannia. This analysis sheds light on how ACs have evolved to allow diverse trypanosomatids to occupy multifarious niches and assume various lifestyles.

Frequent Recombination Events in Leishmania donovani: Mining Population Data

The Leishmania donovani species complex consists of all L. donovani and L. infantum strains mainly responsible for visceral leishmaniasis (VL). It was suggested that genome rearrangements in Leishmania spp. occur very often, thus enabling parasites to adapt to the different environmental conditions. Some of these rearrangements may be directly linked to the virulence or explain the reduced efficacy of antimonial drugs in some isolates. In the current study, we focused on a large-scale analysis of putative gene conversion events using publicly available datasets. Previous population study of L. donovani suggested that population variability of L. donovani is relatively low, however the authors used masking procedures and strict read selection criteria. We decided to re-analyze DNA-seq data without masking sequences, because we were interested in the most dynamic fraction of the genome. The majority of samples have an excess of putative gene conversion/recombination events in the noncoding regions, however we found an overall excess of putative intrachromosomal gene conversion/recombination in the protein coding genes, compared to putative interchromosomal gene conversion/recombination events.

[Evaluation of the reproductive potential of Encephalitozoon intestinalis in four different cell line]

Microsporidia are parasites that can cause infections in many vertebrate and invertebrate organisms and produce small spores resistant to environmental conditions. As they are obligate intracellular parasites, axenic cultures cannot be performed. The aim of this study was to investigate the reproductive potential of the parasite in human colon epidermal adenocarcinoma (Caco-2), human monocytic (U937), African green monkey renal epithelial (VERO) and human kidney epithelial (HEK-293) cell lines of tissue and organs where the parasite is located by following the culture of the parasites and the amount of spores for six weeks. RPMI-1640 medium was used for the cultivation of U937 cells, while DMEM was used for other cell lines and the immature U937 cells were stimulated with Phorbol-12-Myristate-13-Acetate before infection. All of the host cell groups were infected with freshly collected Encephalitozoon intestinalis spores in ratio 1:30 and free spores in the culture media were removed after overnight incubation at 37°C under 5% CO2 condition for parasite invasion. The first release of the spores from the infected cells was observed and recorded by following for six weeks. Furthermore, the spore density released from each cell groups was evaluated by measuring the parasite load by Thoma cell counting chamber and quantified by real-time PCR. As a result of the study, it was observed that four cell lines could be infected by E.intestinalis and the spore production can be maintained for six weeks. It was observed that the monolayer macrophages and CaCo-2 cells, started to be detached from the culture flasks in few days following the parasite invasion, thus decreasing the number of host cells. After 1-2 weeks, HEK-293 cells were also detached from the surface, thus negatively affected the pure spore production by contaminating the media with dead host cell suspension. Spores started to appear in VERO cell media at the end of the second week after initial infection, while it took longer time for other cells to start releasing spores. Over the course of six weeks, the VERO cell line had the highest spore-producing potential among the other cell lines. In conclusion, this study compared the potential for reproduction of E.intestinalis in three human cell lines and monkey originated VERO cell line. This study demonstrated that cells derived from the tissues or organs where Microsporidia species causes disseminated infections could be infected by the parasitic spores in vitro. Additionally, the parasite can survive and propagate longer than six weeks. The authors believe that the results of this study will contribute to the further studies related to the parasite in the area of genetics, pharmacology, biochemistry, immunology and eradication studies.

Evaluation of four commercial DNA extraction kits for the detection of Microsporidia and the importance of pretreatments in DNA isolation

Microsporidia are obligate intracellular parasitic protozoa infecting the wide variety of hosts and are commonly known as a cause of chronic diarrhea particularly in immunocompromised individuals. Molecular-based tests have high sensitivity and specificity in disease diagnosis. However, these tests' performance relies on the isolation of DNA in a good concentration. The standard procedures of commercial DNA extraction kits are usually insufficient for this purpose due to the tough walls of spores. This study aimed to test the significance of pretreatments by glass beads and freeze-thawing processes in DNA isolation from microsporidia spores. The parasite was cultured in growing Vero cells and seven serial dilutions were prepared from the collected spores. DNA purification was performed according to different tissue kits and stool kit procedures with and without any pretreatment. Concentration of isolated DNA samples were evaluated by real-time PCR. As a result of this study, the detectable amount of spores is minimum 10 spores in each 100 μ! sample according to the different tissue kits' standard protocols. However, according to the DNA stool mini kit, the detectable amount of spores was found to be 1,000 spores/100 μl of stool sample when pretreated with both the freeze-thawing and glass beads methods.In conclusion, the current study demonstrated that further pretreatments are an essential process for DNA extraction from the stool specimens in order to avoid possible false negativity in the diagnosis of microsporidiosis.