The present study provides a novel approach for klotho gene therapy and demonstrates that direct up-regulation of klotho in the brain might improve aging-related memory impairments and decrease oxidative stress. The underlying mechanism of this effect likely involves the inhibition of the Akt/FoxO1 pathway.
BackgroundPeroxiredoxins (Prxs) are proposed to function as damage-associated molecular patterns (DAMPs) and contribute to post-ischemic neuroinflammation and brain injury by activating Toll-like receptor (TLR) 4 at the acute and subacute phases after ischemic stroke. However, there are few studies concerning the inflammatory profiles of six distinct subtypes of Prxs (Prx1–Prx6). Our previous study demonstrated that the protective effect of ligustilide (LIG) against cerebral ischemia was associated with inhibition of neuroinflammatory response and Prx/TLR4 signaling in rats. Herein, the present study explored the inflammatory members of Prxs and the effect of LIG on their inflammatory responses in macrophages.Methodology/Principal FindingsThe murine RAW264.7 macrophages were treated with each of exogenous recombinant Prxs at a range of 1 to 50 nM for 24 h. The WST-1 test showed that Prx3 exhibited a significant cytotoxicity, whereas the rest five Prxs did not affect cellular viability. The quantitative measurements with spectrometry or ELISA indicated that three subtypes, Prx1, Prx2 and Prx4, increased production of proinflammatory mediators, including nitric oxide (NO) metabolites, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in a concentration-dependent manner. Immunostaining demonstrated that 20 nM Prx1, Prx2 or Prx4 significantly increased expression of TLR4 and iNOS and nuclear translocation of NF-κB p65. However, Prx5 and Prx6 showed no poinflammatory effect in macrophages. Remarkably, LIG treatment effectively inhibited the inflammatory response induced by Prx1, Prx2 and Prx4.ConclusionThree members of Prxs, Prx1, Prx2 and Prx4, are inflammatory DAMPs that induce TLR4 activation and inflammatory response in macrophages, which is effectively inhibited by LIG. These results suggest that inflammatory Prxs-activated macrophages may provide a novel cellular model for screening the potential inhibitors of DAMPs-associated inflammatory diseases such as stroke. Moreover, selective blocking strategies targeting the inflammatory subtypes of Prxs probably provide promising therapeutic approaches with a prolonged time window for stroke.
BackgroundThe aim of this study was to investigate the effects of Atractylenolide-I (AT-I), a naturally occurring sesquiterpene lactone isolated from Atractylodes macrocephala Koidz, on human ovarian cancer cells.Material/MethodsThe viability and anchorage-independent growth of ovarian cancer cells were evaluated using MTT and colony formation assay, respectively. Cell cycle and apoptosis were detected with flow cytometry analysis. The level of cyclin B1 and CDK1 was measured using qPCR and ELISA analysis. The expression of Bax, cleaved caspase-9, cleaved caspase-3, cytochrome c, AIF, and Bcl-2, and phosphorylation level of PI3K, AKT, and mTOR were determined with Western blot analysis.ResultsAT-I decreased the cell viability and suppressed anchorage-independent growth of A2780 cells. Cell cycle was arrested in G2/M phase transition by AT-I treatment, which was related to decreased expression of cyclin B1 and CDK1 in a dose-dependent manner. In addition, the treatment induced apoptosis, as shown by up-regulation of Bax, cleaved caspase-9, cleaved caspase-3, and cytosolic release of cytochrome c and AIF, and down-regulation of Bcl-2, in a dose-dependent manner. Then, the effects of AT-I on PI3K/Akt/mTOR pathways were examined to further investigate the underlying anti-cancer mechanism of AT-I, and the results showed that treatment with AT-I significantly decreased the phosphorylation level of PI3K, Akt, and mTOR.ConclusionsThis study demonstrated that AT-I induced cell cycle arrest and apoptosis through inhibition of PI3K/Akt/mTOR pathway in ovarian cancer cells. These results suggest that AT-I might be a potential therapeutic agent in the treatment of ovarian cancer.
In the studies of chemoprevention, the Nrf2-ARE signaling pathway has received widespread attention due to its anti-inflammatory and anti-oxidation effects. Our previous study indicated that atractylenolide II, which is an active component of Atractylodes macrocephala Koidz, is a potential activator of Nrf2-ARE signaling pathway. In this study, we observed that atractylenolide II significantly increased Nrf2 expressing, nuclear translocation and the expression of its downstream detoxifying enzymes, thus decreasing 17β-Estradiol induced malignant transformation in MCF 10A cells, and we found that atractylenolide II acted through JNK/ERK-Nrf2-ARE pathway. Furthermore, atractylenolide II significantly reduced N-Nitroso-N-methylurea induced tumor incidence, multiplicity and volume, with activation of Nrf2-ARE pathway and decreased inflammation and oxidative stress in rat mammary tissue. Collectively, our results suggested that atractylenolide II could protect against mammary tumorigenesis both in vivo and in vitro via activating Nrf2-ARE signaling pathway, which supported atractylenolide II as a novel chemopreventive agent of breast cancer.
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