The role of innate immunity and bioactive lipid mediators in COVID-19 and influenza

In this review, we discuss spatiotemporal kinetics and inflammatory signatures of innate immune cells specifically found in response to SARS-CoV-2 compared to influenza virus infection. Importantly, we cover the current understanding on the mechanisms by which SARS-CoV-2 may fail to engage a coordinated type I response and instead may lead to exaggerated inflammation and death. This knowledge is central for the understanding of available data on specialized pro-resolving lipid mediators in severe SARS-CoV-2 infection pointing toward inhibited E-series resolvin synthesis in severe cases. By investigating a publicly available RNA-seq database of bronchoalveolar lavage cells from patients affected by COVID-19, we moreover offer insights into the regulation of key enzymes involved in lipid mediator synthesis, critically complementing the current knowledge about the mediator lipidome in severely affected patients. This review finally discusses different potential approaches to sustain the synthesis of 3-PUFA-derived pro-resolving lipid mediators, including resolvins and lipoxins, which may critically aid in the prevention of acute lung injury and death from COVID-19.Proteomic

RefGenes: identification of reliable and condition specific reference genes for RT-qPCR data normalization

Background RT-qPCR is a sensitive and increasingly used method for gene expression quantification. To normalize RT-qPCR measurements between samples, most laboratories use endogenous reference genes as internal controls. There is increasing evidence, however, that the expression of commonly used reference genes can vary significantly in certain contexts. Results Using the Genevestigator database of normalized and well-annotated microarray experiments, we describe the expression stability characteristics of the transciptomes of several organisms. The results show that a) no genes are universally stable, b) most commonly used reference genes yield very high transcript abundances as compared to the entire transcriptome, and c) for each biological context a subset of stable genes exists that has smaller variance than commonly used reference genes or genes that were selected for their stability across all conditions. Conclusion We therefore propose the normalization of RT-qPCR data using reference genes that are specifically chosen for the conditions under study. RefGenes is a community tool developed for that purpose. Validation RT-qPCR experiments across several organisms showed that the candidates proposed by RefGenes generally outperformed commonly used reference genes. RefGenes is available within Genevestigator at http://www.genevestigator.com

HIV-1 Nef increases astrocyte sensitivity towards exogenous hydrogen peroxide

<p>Abstract</p> <p>Background</p> <p>HIV-1 infected individuals are under chronic exposure to reactive oxygen species (ROS) considered to be instrumental in the progression of AIDS and the development of HIV-1 associated dementia (HAD). Astrocytes support neuronal function and protect them against cytotoxic substances including ROS. The protein HIV-1 Nef, a progression factor in AIDS pathology is abundantly expressed in astrocytes in patients with HAD, and thus may influence its functions.</p> <p>Results</p> <p>Endogenous expressed HIV-1 Nef leads to increased sensitivity of human astrocytes towards exogenous hydrogen peroxide but not towards TNF-alpha. Cell death of <it>nef</it>-expressing astrocytes exposed to 10 μM hydrogen peroxide for 30 min occurred within 4 h.</p> <p>Conclusion</p> <p>HIV-1 Nef may contribute to neuronal dysfunction and the development of HAD by causing death of astrocytes through decreasing their tolerance for hydrogen peroxide.</p

Effects of pine pollen extracts on the proliferation and mRNA expression of porcine ileal cell cultures

Masson pine pollen has been used in the traditional Chinese medicine for several hundred years and is attributed a variety of health promoting effects including effectiveness against disorders of the digestive system. But only in recent years some evidence has been found that pine pollen and its compounds do influence e.g. inflammatory activities in mice or mRNA expression profiles in piglets. At least apart of these effects have been attributed to the content of polyphenols in pollen.In the present study different extracts of Pinus massoniana pollen were analyzed for their effects on cell proliferation and mRNA expression levels of selected genes. Cell proliferation was analyzed using an electronic cell impedance sensing technique and relative gene expression profiles were investigated using qRT-PCR. It was found that water and 50% ethanol extracts of Masson pine pollen at a concentration equivalent to 1 % unprocessed pollen decreased cell proliferation significantly (