Enzymatic properties of human glucuronyltransferase and a sensitive method for its assay in a stable B lymphocyte cell line

Properties of lymphocyte glucuronyltransferase were studied in homogenates of SN1006 cells. A sensitive assay procedure for lymphocyte glucuronyltransferase was developed utilizing radioactive testosterone as the acceptor substrate and TLC for separation of the metabolite. The method is capable of detecting picomolar quantities of the product. The enzyme activity exhibited a broad pH optimum, and was subject to activation by the detergent Lubrol WX and Mn++ ions. The activity conformed to the Michaelis-Menten kinetics giving apparent Km values of 0.8 mM and 11 microM, for UDPGA and testosterone, respectively. 4-Methylumbelliferone, a-naphthol and p-nitrophenol behaved as competitive inhibitors of testosterone glucuronidation. The results indicate that the method could be used for genetic studies of human lymphocyte glucuronyltransferase, and that the enzyme is of consequence in detoxication of exogenous as well as endogenous substrates.     

Are you what you eat? A highly transient and prey‐influenced gut microbiome in the grey house spider Badumna longinqua

Stable core microbial communities have been described in numerous animal species and are commonly associated with fitness benefits for their hosts. Recent research, however, highlights examples of species whose microbiota are transient and environmentally derived. Here, we test the effect of diet on gut microbial community assembly in the spider Badumna longinqua. Using 16S rRNA gene amplicon sequencing combined with quantitative PCR, we analyzed diversity and abundance of the spider's gut microbes, and simultaneously characterized its prey communities using nuclear rRNA markers. We found a clear correlation between community similarity of the spider's insect prey and gut microbial DNA, suggesting that microbiome assembly is primarily diet‐driven. This assumption is supported by a feeding experiment, in which two types of prey—crickets and fruit flies—both substantially altered microbial diversity and community similarity between spiders, but did so in different ways. After cricket consumption, numerous cricket‐derived microbes appeared in the spider's gut, resulting in a rapid homogenization of microbial communities among spiders. In contrast, few prey‐associated bacteria were detected after consumption of fruit flies; instead, the microbial community was remodelled by environmentally sourced microbes, or abundance shifts of rare taxa in the spider's gut. The reshaping of the microbiota by both prey taxa mimicked a stable core microbiome in the spiders for several weeks post feeding. Our results suggest that the spider's gut microbiome undergoes pronounced temporal fluctuations, that its assembly is dictated by the consumed prey, and that different prey taxa may remodel the microbiota in drastically different ways.     

Beyond the landscape: Resistance modelling infers physical and behavioural gene flow barriers to a mobile carnivore across a metropolitan area

Urbanization affects key aspects of wildlife ecology. Dispersal in urban wildlife species may be impacted by geographical barriers but also by a species’ inherent behavioural variability. There are no functional connectivity analyses using continuous individual‐based sampling across an urban‐rural continuum that would allow a thorough assessment of the relative importance of physical and behavioural dispersal barriers. We used 16 microsatellite loci to genotype 374 red foxes (Vulpes vulpes) from the city of Berlin and surrounding rural regions in Brandenburg in order to study genetic structure and dispersal behaviour of a mobile carnivore across the urban‐rural landscape. We assessed functional connectivity by applying an individual‐based landscape genetic optimization procedure. Three commonly used genetic distance measures yielded different model selection results, with only the results of an eigenvector‐based multivariate analysis reasonably explaining genetic differentiation patterns. Genetic clustering methods and landscape resistance modelling supported the presence of an urban population with reduced dispersal across the city border. Artificial structures (railways, motorways) served as main dispersal corridors within the cityscape, yet urban foxes avoided densely built‐up areas. We show that despite their ubiquitous presence in urban areas, their mobility and behavioural plasticity, foxes were affected in their dispersal by anthropogenic presence. Distinguishing between man‐made structures and sites of human activity, rather than between natural and artificial structures, is thus essential for better understanding urban fox dispersal. This differentiation may also help to understand dispersal of other urban wildlife and to predict how behaviour can shape population genetic structure beyond physical barriers.     

The expression of Galectin-3 in endometrial cancer: a systematic review of the literature

Molecular Biology Reports - Galectin-3 is part of a protein group called lectins and acts as a multifunctional glycoprotein due to its expression location. Galectin-3 is expressed by different...     

SARS-CoV-2 RNA screening in routine pathology specimens

Virus detection methods are important to cope with the SARS-CoV-2 pandemics. Apart from the lung, SARS-CoV-2 was detected in multiple organs in severe cases. Less is known on organ tropism in patients developing mild or no symptoms, and some of such patients might be missed in symptom-indicated swab testing. Here, we tested and validated several approaches and selected the most reliable RT-PCR protocol for the detection of SARS-CoV-2 RNA in patients’ routine diagnostic formalin-fixed and paraffin-embedded (FFPE) specimens available in pathology, to assess (i) organ tropism in samples from COVID-19-positive patients, (ii) unrecognized cases in selected tissues from negative or not-tested patients during a pandemic peak, and (iii) retrospectively, pre-pandemic lung samples. We identified SARS-CoV-2 RNA in seven samples from confirmed COVID-19 patients, in two gastric biopsies, one small bowel and one colon resection, one lung biopsy, one pleural resection and one pleural effusion specimen, while all other specimens were negative. In the pandemic peak cohort, we identified one previously unrecognized COVID-19 case in tonsillectomy samples. All pre-pandemic lung samples were negative. In conclusion, SARS-CoV-2 RNA detection in FFPE pathology specimens can potentially improve surveillance of COVID-19, allow retrospective studies, and advance our understanding of SARS-CoV-2 organ tropism and effects.     

Enzymatic synthesis of perillyl alcohol derivatives and investigation of their antiproliferative activity

The monoterpene perillyl alcohol (POH), an intermediate in the plant terpenoid biosynthetic pathway, has well-established tumor chemopreventive and chemotherapeutic potential. We have previously shown that the primary hydroxyl group of POH is essential for its antitumor and anti-angiogenic activities. In the current study we present the enzymatic synthesis of two POH derivatives with different polar and hydrophobic characteristics, namely perillyl glucoside and perillyl glucoside fatty ester, through a two-step modification. Initial glucosylation of POH on its active hydroxyl group with D-(+)-glucose and subsequent esterification of the perillyl glucoside product with vinyl laurate were carried out using almond β-glucosidase and lipase B from Candida antarctica, respectively, in a low-water system. Optimization of enzymatic reactions was performed to achieve the highest possible conversion yields. The antitumor cell proliferation activity against mouse Lewis lung carcinoma cells was retained in both derivatives, although the perillyl glucoside ester showed greater inhibition than perillyl glucoside. Our results underline the feasibility of enzymatically producing novel bioactive analogs of phytochemicals displaying useful physicochemical properties.