Fish oil supplementation reverses the effect of cholesterol on apoptotic gene expression in smooth muscle cells

The In Vitro, Ex Vivo, and In Vivo Effect of Edible Oils: A Review on Cell Interactions

Consumption of edible oils is a significant part of the dietary pattern in the developed and developing world. Marine and vegetable oils are assumed to be part of a healthy food pattern, especially if one takes into account their potential role in protecting against inflammation, cardiovascular disease, and metabolic syndrome due to the presence of polyunsaturated fatty acids and minor bioactive compounds. Exploring the potential effect of edible fats and oils on health and chronic diseases is an emerging field worldwide. This study reviews the current knowledge of the in vitro, ex vivo, and in vivo effect of edible oils in contact with various cell types and aims to demonstrate which nutritional and bioactive components of a variety of edible oils present biocompatibility, antimicrobial properties, antitumor activity, anti-angiogenic activity, and antioxidant activity. Through this review, a wide variety of cell interactions with edible oils and their potential to counteract oxidative stress in pathological conditions are presented as well. Moreover, the gaps in current knowledge are also highlighted, and future perspectives on edible oils and their health benefits and potential to counteract a wide variety of diseases through possible molecular mechanisms are also discussed.

Omega-3 fatty acid protects cardiomyocytes against hypoxia-induced injury through targeting MiR-210-3p/CASP8AP2 axis

MicroRNAs (miRs) regulate diverse biological functions in both normal and pathological cellular conditions by post-transcriptional regulation of various genes expression. Nevertheless, the role of miRs in regulating the protective functions of omega-3 fatty acid in relation to hypoxia in cardiomyocytes remains unknown. The aim of this study was to investigate the effects of omega-3 fatty acid supplementation on cardiomyocyte apoptosis and further delineate the mechanisms underlying microRNA-210 (miRNA-210)-induced cardiomyocyte apoptosis in vitro. H9C2 cultured cells were first subjected to hypoxia followed by a subsequent treatment with main component of the Omega-3 fatty acid, Docosahexaenoic Acid (DHA). Cell apoptosis were detected by flow cytometry and the expression of miR-210-3p were detected by RT-qPCR and caspase-8-associated protein 2 (CASP8AP2) at protein levels by immunoblotting. Dual luciferase assay was used to verify the mutual effect between miR-210-3p and the 3'-untranslated region (UTR) of CASP8AP2 gene. DHA was shown to reduce apoptosis in H9C2 cells subjected to hypoxia. While DHA caused a significant increase in the expression of miR-210-3p, there was a marked reduction in the protein expression of CASP8AP2. MiR-210-3p and CASP8AP2 were significantly increased in H9C2 cardiomyocyte subjected to hypoxia. Overexpression of miR-210-3p could ameliorate hypoxia-induced apoptosis in H9C2 cells. MiR-210-3p negatively regulated CASP8AP2 expression at the transcriptional level. Both miR-210-3p mimic and CASP8AP2 siRNA could efficiently inhibit apoptosis in H9C2 cardiomyocyte subjected to hypoxia. We provide strong evidence showing that Omega-3 fatty acids can attenuate apoptosis in cardiomyocyte under hypoxic conditions via the up-regulation of miR-210-3p and targeting CASP8AP2 signaling pathway.

25-hydroxycholesterol down-regulates oxysterol binding protein like 2 (OSBPL2) via the p53/SREBF2/NFYA signaling pathway

Oxysterol Binding Protein Like 2 (OSBPL2) is a lipid-binding protein implicated in various cellular processes. Previous studies have shown that depression of OSBPL2 significantly increases the level of cellular 25-hydroxycholesterol (25-OHC) which regulates the expression of lipid-metabolism-related genes. However, whether 25-OHC can regulate the expression of OSBPL2 remains unanswered. This study aimed to explore the molecular mechanism of 25-OHC regulating the expression of OSBPL2. Using dual-luciferase reporter assay, we found a decrease of nuclear transcription factor Y subunit alpha (NFYA) bound with OSBPL2 promoter when HeLa cells were treated with 25-OHC. Furthermore, transcriptome sequencing and RNA interference results revealed that the p53/sterol regulatory element binding transcription factor 2 (SREBF2) signaling pathway was involved in the NFYA-dependent transcription of OSBPL2 induced by 25-OHC. Based on these results, we concluded that pleomorphic adenoma gene 1 (PLAG1) and NFYA participated in the basal transcription of OSBPL2 and that 25-OHC decreased the transcription of OSBPL2 via the p53/SREBF2/NFYA signaling pathway. 25-OHC will accumulate over time in OSBPL2 knockdown cells. These results may provide a new insight into the deafness caused by OSBPL2 mutation.

Polyunsaturated fatty acids ameliorate aging via redox-telomere-antioncogene axis

Polyunsaturated fatty acids (PUFA), a group of nourishing and health-promoting nutrients, ameliorate age-related chronic diseases. However, how PUFA especially n-3 PUFA exert anti-aging functions remains poorly understood. Here we link fish oil, docosahexaenoic acid (DHA) and arachidonic acid (AA) to the aging etiology via a redox-telomere-antioncogene axis based on D-galactose-induced aging mice. Both fish oil and PUFA enhanced hepatic superoxide dismutase (SOD) and catalase activities and cardiac SOD activities within the range of 18%-46%, 26%-65% and 19%-58%, respectively, whereas reduced cerebral monoamine oxidase activity, plasma F₂-isoprostane level and cerebral lipid peroxidation level by 56%-90%, 20%-79% and 16%-54%, respectively. Thus, PUFA improve the in vivo redox and oxidative stress induced aging process, which however does not exhibit a dose-dependent manner. Notably, both PUFA and fish oil effectively inactivated testicular telomerase and inhibited c-Myc-mediated telomerase reverse transcriptase expression, whereas n-3 PUFA rather than n-6 PUFA protected liver and testes against telomere shortening within the range of 13%-25% and 25%-27%, respectively. Therefore, n-3 PUFA may be better at inhibiting the DNA damage induced aging process. Surprisingly, only DHA significantly suppressed cellular senescence pathway evidenced by testicular antioncogene p16 and p53 expression. This work provides evident support for the crosstalk between PUFA especially n-3 PUFA and the aging process via maintaining the in vivo redox homeostasis, rescuing age-related telomere attrition and down-regulating the antioncogene expression.

Cardiomyocyte apoptosis in ischaemia-reperfusion due to the exogenous oxidants at the time of reperfusion

Various studies performed on different models have demonstrated that apoptosis occurs in ischaemic-reperfused myocardium in vivo; however, the individual contribution of ischaemia and reperfusion to CMC (cardiomyocyte) apoptosis remains uncertain. We have determined the main inducer of CMC apoptosis in ischaemia-reperfusion by exposing CMCs to either 30 min ischaemia followed by reperfusion or to 25-OH-cholesterol (25-hydroxycholesterol) for 1-3 days. Both ischaemia-reperfusion and exogenous oxidants increased the Bax/Bcl-2 ratio, a favourable effect for the apoptotic process. However, apoptosis was not observed in ischaemic CMCs in the absence of reperfusion. Moreover, reperfusion after 30 min ischaemia did not make an important contribution to CMC apoptosis in culture in terms of caspase 3 activation. In contrast, 25-OH-cholesterol promoted CMC apoptosis by a caspase 3-dependent mechanism that involved the transcriptional activation of the pro-apoptotic protein, Bax and post-translational degradation of the anti-apoptotic protein, Bcl-2. From these results, we conclude that CMC apoptosis is not induced by ischaemia per se, but by the oxidants from the surrounding environment at the time of reperfusion. These exogenous oxidants exacerbate the alterations induced by ischaemia and complete the apoptotic process at the time when ATP and glucose levels are restored.