Effect of Eicosapentaenoic Acid Supplementation on Murine Preadipocytes 3T3-L1 Cells Activated with Lipopolysaccharide and/or Tumor Necrosis Factor-α

The beneficial effect of n-3 fatty acids can be related to anti-inflammatory properties. The aim of the study was to analyzed the effect of eicosapentaenoic acid (EPA) on 3T3-L1 cells (murine embryonic fibroblasts‒preadipocytes) activated with inflammatory factors (IF). Cells were incubated with 50 µmol of EPA for 48 h, and then activated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The level of cycloxygenase-2 (Prostaglandin-Endoperoxide Synthase 2, PTGS2, COX-2), cytosolic prostaglandin synthase E2 (cPGES), fatty acid binding protein 4 (FABP4), toll-like receptor 4 (TLR4), glucose receptor type 4 (GLUT-4), and cannabinoid receptor 2 (CB2) was determined using Western blot analysis. The phospholipase A2 (Pla2g4a), and prostaglandin-Endoperoxide Synthase 2 (Ptgs2) gene expression was analyzed by real-time qPCR. After EPA and IF activation, a significant decrease in the COX-2, cPGES, and TRL4 protein levels was observed. Incubation of cells with EPA and IF resulted in a decrease in Ptgs2 and an increase in the Pla2g4a gene. A significant increase in the CB2 protein was observed in adipocytes co-treated with EPA and IF. The results indicated an anti-inflammatory properties of EPA. Interestingly, the activation of the GLUT4 receptor by EPA suggests an unique role of this FA in the regulation of the adipocyte metabolism and prevention of insulin resistance.

Prostaglandin-Endoperoxide Synthase 2 (PTGS2) in the Oviduct: Roles in Fertilization and Early Embryo Development

The mammalian oviduct is a dynamic organ where important events such as final maturation of oocytes, transport of gametes, sperm capacitation, fertilization, embryo development, and transport take place. Prostaglandin-endoperoxide synthase 2 (PTGS2), also known as cyclooxygenase 2 (COX-2), is the rate-limiting enzyme in the production of prostaglandins (PGs) and plays an essential role during early pregnancy, including ovulation, fertilization, implantation, and decidualization. Even though the maternal-embryo communication originates in the oviduct, not many studies have systemically investigated PTGS2 signaling during early development. Most of the studies investigating implantation and decidualization processes in Ptgs2-/- mice employed embryo transfer into the uterus, thereby bypassing the mammalian oviduct. Consequently, an understanding of the mechanistic action as well as the regulation of PTGS2 and derived PGs in oviductal functions is far from complete. In this review, we aim to focus on the importance of PTGS2 and associated PGs signaling in the oviduct particularly in humans, farm animals, and laboratory rodents to provide a broad perspective to guide further research in this field. Specifically, we review the role of PTGS2-derived PGs in fertilization, embryo development, and transport. We focus on the actions of ovarian steroid hormones on PTGS2 regulation in the oviduct. Understanding of cellular PTGS2 function during early embryo development and transport in the oviduct will be an important step toward a better understanding of reproduction and may have potential implication in the assisted reproductive technology.

Transcriptomic analysis of tobacco-flavored E-cigarette and menthol-flavored E-cigarette exposure in the human middle ear

Electronic cigarettes (e-cigarettes) are the most widely used electronic nicotine delivery systems and are designed to imitate smoking and aid in smoking cessation. Although the number of e-cigarette users is increasing rapidly, especially among young adults and adolescents, the potential health impacts and biologic effects of e-cigarettes still need to be elucidated. Our previous study demonstrated the cytotoxic effects of electronic liquids (e-liquids) in a human middle ear epithelial cell (HMEEC-1) line, which were affected by the manufacturer and flavoring agents regardless of the presence of nicotine. In this study, we aimed to evaluate the gene expression profile and identify potential molecular modulator genes and pathways in HMEEC-1 exposed to two different e-liquids (tobacco- and menthol-flavored). HMEEC-1 was exposed to e-liquids, and RNA sequencing, functional analysis, and pathway analysis were conducted to identify the resultant transcriptomic changes. A total of 843 genes were differentially expressed following exposure to the tobacco-flavored e-liquid, among which 262 genes were upregulated and 581 were downregulated. Upon exposure to the menthol-flavored e-liquid, a total of 589 genes were differentially expressed, among which 228 genes were upregulated and 361 were downregulated. Among the signaling pathways associated with the differentially expressed genes mediated by tobacco-flavored e-liquid exposure, several key molecular genes were identified, including IL6 (interleukin 6), PTGS2 (prostaglandin-endoperoxide synthase 2), CXCL8 (C-X-C motif chemokine ligand 8), JUN (Jun proto-oncogene), FOS (Fos proto-oncogene), and TP53 (tumor protein 53). Under menthol-flavored e-liquid treatment, MMP9 (matrix metallopeptidase 9), PTGS2 (prostaglandin-endoperoxide synthase 2), MYC (MYC proto-oncogene, bHLH transcription factor), HMOX1 (heme oxygenase 1), NOS3 (nitric oxide synthase 3), and CAV1 (caveolin 1) were predicted as key genes. In addition, we identified related cellular processes, including inflammatory responses, oxidative stress and carcinogenesis, under exposure to tobacco- and menthol-flavored e-liquids. We identified differentially expressed genes and related cellular processes and gene signaling pathways after e-cigarette exposure in human middle ear cells. These findings may provide useful evidence for understanding the effect of e-cigarette exposure.

The Expression Pattern of Prostaglandin-Endoperoxide Synthase-2 in Immature Oocytes and Surrounding Cumulus Cells May Explain A Disrupted Oocyte Maturation Process

<p><strong>Objective:</strong> To evaluate the correlation between the gene expression of prostaglandin-endoperoxide synthase-2 in the cumulus-oocyte complex with the level of prostaglandin-endoperoxide synthase-2 in follicular fluid and follicle diameter, oocyte maturation, and fertilization capacity.</p><p><strong>Study Design:</strong> As the study group, 26 cumulus-oocyte complexes and 26 follicular fluids obtained from immature (n=10) or unfertilized mature oocytes (n=16) and as the control group, 26 cumulus complexes and 26 follicular fluids surrounding mature and fertilized oocytes were retrieved one by one totally from 32 patients in 32 intracytoplasmic sperm injection cycles. </p><p><strong>Results:</strong> There was no significant efficacy of prostaglandin-endoperoxide synthase-2 gene expressions in cumulus complexes and the level of prostaglandin-endoperoxide synthase-2 in follicular fluids in terms of oocyte maturation stage. The level of prostaglandin-endoperoxide synthase-2 in follicular fluids and follicle diameters showed a significantly positive correlation in the mature and fertilized oocyte group (r=0.414; p=0.035). </p><p><strong>Conclusions:</strong> Although the prostaglandin-endoperoxide synthase-2 gene expressions in immature oocytes and their cumulus cells were similar to those in oocytes that have completed their nuclear and cytoplasmic maturation, the level of prostaglandin-endoperoxide synthases-2 in the follicular fluid and follicle diameter correlation may lead to new clinical approaches in cases of premature follicular rupture before oocyte maturation is completed.</p>