Nutrient starvation-induced oxidative stress-mediated lipid accumulation in Tetradesmus obliquus KMC24

Author(s):  
Madonna Roy ◽  
Sounak Bera ◽  
Kaustubha Mohanty
Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 767
Author(s):  
He N. Xu ◽  
Joanna Floros ◽  
Lin Z. Li ◽  
Shaili Amatya

Employing the optical redox imaging technique, we previously identified a significant redox shift of nicotinamide adenine dinucleotide (NAD and the reduced form NADH) in freshly isolated alveolar macrophages (AM) from ozone-exposed mice. The goal here was twofold: (a) to determine the NAD(H) redox shift in cryopreserved AM isolated from ozone-exposed mice and (b) to investigate whether there is a difference in the redox status between cryopreserved and freshly isolated AM. We found: (i) AM from ozone-exposed mice were in a more oxidized redox state compared to that from filtered air (FA)-exposed mice, consistent with the results obtained from freshly isolated mouse AM; (ii) under FA exposure, there was no significant NAD(H) redox difference between fresh AM that had been placed on ice for 2.5 h and cryopreserved AM; however, under ozone exposure, fresh AM were more oxidized than cryopreserved AM; (iii) via the use of nutrient starvation and replenishment and H2O2-induced oxidative stress of an AM cell line, we showed that this redox difference between cryopreserved and freshly isolated AM is likely the result of the double “hit”, i.e., the ozone-induced oxidative stress plus nutrient starvation that prevented freshly isolated AM from a full recovery after being on ice for a prolonged time period. The cryopreservation technique we developed eliminates/minimizes the effects of oxidative stress and nutrient starvation on cells. This method can be adopted to preserve lung macrophages from animal models or clinical patients for further investigations.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 626
Author(s):  
Li Xiao ◽  
Nobuhiko Miwa

Reactive oxygen species (ROS)-induced oxidative stress in adipose tissue is associated with inflammation and the development of obesity-related metabolic disorders. The aim of this study is to investigate the effects of hydrogen nano-bubble water (HW) on ROS generation, adipogenesis, and interleukin-6 (IL-6) secretion in hydrogen peroxide (H2O2) or phorbol 12-myristate 13-acetate (PMA)-stimulated OP9 adipocytes, and three-dimensional (3D) subcutaneous adipose equivalents. Nanoparticle tracking analysis showed that fresh HW contains 1.17 × 108/mL of nano-sized hydrogen bubbles. Even after 8 to 13 months of storage, approximately half of the bubbles still remained in the water. CellROX® staining showed that HW could diminish H2O2- or PMA-induced intracellular ROS generation in human keratinocytes HaCaT and OP9 cells. We discovered that PMA could markedly increase lipid accumulation to 180% and IL-6 secretion 2.7-fold in OP9 adipocytes. Similarly, H2O2 (5 µM) also significantly stimulated lipid accumulation in OP9 cells and the 3D adipose equivalents. HW treatment significantly repressed H2O2- or PMA-induced lipid accumulation and IL-6 secretion in OP9 adipocytes and the 3D adipose equivalents. In conclusion, HW showed a possibility of repressing oxidative stress, inflammatory response, and adipogenesis at cellular/tissue levels. It can be used for preventing the development of metabolic disorders amongst obese people.


2021 ◽  
Vol 22 (16) ◽  
pp. 8847
Author(s):  
Fangfang Tie ◽  
Jin Ding ◽  
Na Hu ◽  
Qi Dong ◽  
Zhi Chen ◽  
...  

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases which lacks ideal treatment options. Kaempferol and kaempferide, two natural flavonol compounds isolated from Hippophae rhamnoides L., were reported to exhibit a strong regulatory effect on lipid metabolism, for which the mechanism is largely unknown. In the present study, we investigated the effects of kaempferol and kaempferide on oleic acid (OA)-treated HepG2 cells, a widely used in vitro model of NAFLD. The results indicated an increased accumulation of lipid droplets and triacylglycerol (TG) by OA, which was attenuated by kaempferol and kaempferide (5, 10 and 20 μM). Western blot analysis demonstrated that kaempferol and kaempferide reduced expression of lipogenesis-related proteins, including sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD-1). Expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer binding proteins β (C/EBPβ), two adipogenic transcription factors, was also decreased by kaempferol and kaempferide treatment. In addition, western blot analysis also demonstrated that kaempferol and kaempferide reduced expression of heme oxygenase-1 (HO-1) and nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Molecular docking was performed to identify the direct molecular targets of kaempferol and kaempferide, and their binding to SCD-1, a critical regulator in lipid metabolism, was revealed. Taken together, our findings demonstrate that kaempferol and kaempferide could attenuate OA-induced lipid accumulation and oxidative stress in HepG2 cells, which might benefit the treatment of NAFLD.


2021 ◽  
Author(s):  
Hua Zhao ◽  
yanbing Li

Abstract Objective MicroRNA (miR)-185-3p roles have been probed in multiple cancers, while the underlying function of miR-185-3p in hyperlipidemia remained obscure. This research was conducted to unravel miR-185-3p function in hyperlipidemia development via modulating mastermind-like 1 (MAML1). Methods The hyperlipidemia rat model was constructed. MiR-185-3p and MAML1 levels in hyperlipidemia rats were detected. Adenoviral vectors altering miR-185-3p and MAML1 levels were injected into hyperlipidemia rats to examine the levels of biochemical indices, inflammatory factors, oxidative stress, lipid accumulation and cellular morphology in liver tissues of hyperlipidemia rats. The targeting relation between miR-185-3p and MAML1 was manifested. Results MiR-185-3p levels were depleted while MAML1 expression was elevated in HH rats. MiR-185-3p overexpression or MAML1 silencing reduced levels of inflammatory factors in serum, mitigated oxidative stress and biochemical response, relieved lipid accumulation and cellular morphology in liver tissues; while up-regulated MAML1 reversed the effects of augmented MAML1 in hyperlipidemia rats. MiR-185-3p targeted MAML1. Conclusion Up-regulated miR-185-3p represses hyperlipidemia development via modulating MAML1. This research provides novel therapeutic candidates for the treatment of hyperlipidemia.


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