Assessment of the Microbiome Role in Skin Protection Against UV Irradiation Via Network Analysis
JOURNAL OF LASERS IN MEDICAL SCIENCES
Authors: Heidari, Mohammad Hossein; Razzaghi, Mohammadreza; Baghban, Alireza Akbarzadeh; Rostami-Nejad, Mohammad; Rezaei-Tavirani, Mostafa; Azodi, Mona Zamanian; Zali, Alireza; Ahmadzadeh, Alireza
Abstract
Introduction: Diverse microbiotas which have some contributions to gene expression reside in human skin. To identify the protective role of the skin microbiome against UV exposure, protein-protein interaction (PPI) network analysis is used to assessment gene expression alteration. Methods: A microarray dataset, GEO accession number GSE117359, was considered in this respect. Differential expressed genes (DEGs) in the germ-free (GF) and specific pathogen-free (SPF) groups are analyzed by GEO2R. The top significant DEGs were assigned for network analysis via Cytoscape 3.7.2 and its applications. Results: A total of 28 genes were identified as significant DEGs and the centrality analysis of the network indicated that only one of the seven hub-bottlenecks was from queried genes. The gene ontology analysis of Il6, Cxcl2, Cxcl1, TNF, Il10, Cxcl10, and Mmp9 showed that the crucial genes were highly enriched in the immune system. Conclusion: The skin microbiome plays a significant role in the protection of skin against UV irradiation and the role of TNF and IL6 is prominent in this regard.
In vitro methionine supplementation during lipopolysaccharide stimulation modulates immunometabolic gene network expression in isolated polymorphonuclear cells from lactating Holstein cows
JOURNAL OF DAIRY SCIENCE
Authors: Vailati-Riboni, M.; Xu, T.; Qadir, B.; Bucktrout, R.; Parys, C.; Loor, J. J.
Abstract
Methionine (Met) is one of the 2 most limiting amino acids for milk production in dairy cow diets. The accepted "ideal" ratio of lysine (Lys) to Met (L:M) when formulating diets is 3:1. However, blood from cows fed corn silage-based diets without supplemental rumen-protected Met averages approximately 3.6:1 L:M. Recent in vivo research on cattle immunonutrition has revealed that the immune system could benefit from greater Met supply. To study more closely the effects of different L: M ratios, blood polymorphonuclear cells (PMN) were isolated from 5 Holstein cows in mid-lactation (238 +/- 20 d postpartum, 33.8 +/- 3.8 kg of milk/d; mean +/- SD). The PMN were incubated at 3 different levels of L: M (3.6:1, 2.9:1, or 2.4:1) and stimulated with lipopolysaccharide (LPS) at either 0 or 50 mu g/mL for 2 h at 37 degrees C. Target genes were associated with cytokines, pathogen recognition, nuclear receptors, killing mechanisms, and Met and glutathione metabolism. Data were subjected to ANOVA using PROC MIXED in SAS, with L: M, LPS, and their interaction as fixed effects. Stimulation with LPS upregulated genes related to cytokines (IL1B, TNF, IL10 and IL6) and nuclear receptors, including nuclear factor kappa B (NFKB1) and glucocorticoid receptor (NR3C1), and downregulated the mRNA abundance of chemokine receptor 1 (CXCR1), lysozyme (LYZ) and glutathione reductase (GSR). A linear decrease was observed in the mRNA abundance of TNF when L: M was decreased. A similar response was observed for interleukin-1 receptor-associated kinase 1 (IRAK1) and NFKB1 abundance in cells stimulated with LPS (linear effect). A linear increase of LYZ mRNA expression as L: M decreased was detected in unstimulated cells. Furthermore, a decrease in L: M led to a linear decrease of superoxide dismutase 1 (SOD1) mRNA abundance in cells challenged with LPS. Overall, LPS challenge triggered the activation of isolated PMN from mid-lactation cows. However, data suggest the use of a shorter incubation time to capture the peak response and not the resolution of the inflammatory response as in the present study. Our results indicate a possible involvement of Met in modulating PMN inflammatory and oxidative stress status and in helping the resolution of inflammation after initial stimulation.