ABSTRACT
Potent and selective chemical probes are valuable tools for discovery of novel treatments for human diseases. NF‐κβ‐inducing kinase (NIK) is a key trigger in the development of liver injury ...and fibrosis. Whether inhibition of NIK activity by chemical probes ameliorates liver inflammation and injury is largely unknown. In this study, a small‐molecule inhibitor of NIK, B022, was found to be a potent and selective chemical probe for liver inflammation and injury. B022 inhibited the NIK signaling pathway, including NIK‐induced p100‐to‐p52 processing and inflammatory gene expression, both in vitro and in vivo. Furthermore, in vivo administration of B022 protected against not only NIK but also CCl4‐induced liver inflammation and injury. Our data suggest that inhibition of NIK is a novel strategy for treatment of liver inflammation, oxidative stress, and injury.—Ren, X., Li, X., Jia, L., Chen, D., Hou, H., Rui, L., Zhao, Y., Chen, Z. A small‐molecule inhibitor of NF‐κβ‐inducing kinase (NIK) protects liver from toxin‐induced inflammation, oxidative stress, and injury. FASEB J. 31, 711–718 (2017). http://www.fasebj.org
Abstract Background Tendon stem/progenitor cell (TSPC) senescence contributes to tendon degeneration and impaired tendon repair, resulting in age-related tendon disorders. Ferroptosis, a unique ...iron-dependent form of programmed cell death, might participate in the process of senescence. However, whether ferroptosis plays a role in TSPC senescence and tendon regeneration remains unclear. Recent studies reported that Platelet-derived exosomes (PL-Exos) might provide significant advantages in musculoskeletal regeneration and inflammation regulation. The effects and mechanism of PL-Exos on TSPC senescence and tendon regeneration are worthy of further study. Methods Herein, we examined the role of ferroptosis in the pathogenesis of TSPC senescence. PL-Exos were isolated and determined by TEM, particle size analysis, western blot and mass spectrometry identification. We investigated the function and underlying mechanisms of PL-Exos in TSPC senescence and ferroptosis via western blot, real-time quantitative polymerase chain reaction, and immunofluorescence analysis in vitro. Tendon regeneration was evaluated by HE staining, Safranin-O staining, and biomechanical tests in a rotator cuff tear model in rats. Results We discovered that ferroptosis was involved in senescent TSPCs. Furthermore, PL-Exos mitigated the aging phenotypes and ferroptosis of TSPCs induced by t-BHP and preserved their proliferation and tenogenic capacity. The in vivo animal results indicated that PL-Exos improved tendon-bone healing properties and mechanical strength. Mechanistically, PL-Exos activated AMPK phosphorylation and the downstream nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathway, leading to the suppression of lipid peroxidation. AMPK inhibition or GPX4 inhibition blocked the protective effect of PL-Exos against t-BHP-induced ferroptosis and senescence. Conclusion In conclusion, ferroptosis might play a crucial role in TSPC aging. AMPK/Nrf2/GPX4 activation by PL-Exos was found to inhibit ferroptosis, consequently leading to the suppression of senescence in TSPCs. Our results provided new theoretical evidence for the potential application of PL-Exos to restrain tendon degeneration and promote tendon regeneration.
Oxidative stress-induced mitochondrial dysfunction is implicated in the pathogenesis of intervertebral disc degeneration (IVDD). Sirtuin 3 (SIRT3), a sirtuin family protein located in mitochondria, ...is essential for mitochondrial homeostasis; however, the role of SIRT3 in the process of IVDD has remained elusive. Here, we explored the expression of SIRT3 in IVDD in vivo and in vitro; we also explored the role of SIRT3 in senescence, apoptosis, and mitochondrial homeostasis under oxidative stress. We subsequently activated SIRT3 using honokiol to evaluate its therapeutic potential for IVDD. We assessed SIRT3 expression in degenerative nucleus pulposus (NP) tissues and oxidative stress-induced nucleus pulposus cells (NPCs). SIRT3 was knocked down by lentivirus and activated by honokiol to determine its role in oxidative stress-induced NPCs. The mechanism by which honokiol affected SIRT3 regulation was investigated in vitro, and the therapeutic potential of honokiol was assessed in vitro and in vivo. We found that the expression of SIRT3 decreased with IVDD, and SIRT3 knockdown reduced the tolerance of NPCs to oxidative stress. Honokiol (10 μM) improved the viability of NPCs under oxidative stress and promoted their properties of anti-oxidation, mitochondrial dynamics and mitophagy in a SIRT3-dependent manner. Furthermore, honokiol activated SIRT3 through the AMPK-PGC-1α signaling pathway. Moreover, honokiol treatment ameliorated IVDD in rats. Our study indicated that SIRT3 is involved in IVDD and showed the potential of the SIRT3 agonist honokiol for the treatment of IVDD.
The payment card industry has grown increasingly with the development of online business. However, payment card fraud has become a serious problem around the world. Companies and banks lost huge ...amounts of dollars annually due to fraud. It is necessary to investigate a learning algorithm to detect fraud in finance transaction automatically. In this paper, we put forward a fraud detection algorithm by using neural network. The neural network model and final result will be described to show the superiority of this model.
Deep learning-based cell segmentation is increasingly utilized in cell biology due to the massive accumulation of large-scale datasets and excellent progress in model architecture and instance ...representation. However, the development of specialist algorithms has long been hampered by a paucity of annotated training data, whereas the performance of generalist algorithms is limited without experiment-specific calibration. Here, we present Scellseg, an adaptive pipeline that utilizes a style-aware pre-trained model coupled to a contrastive fine-tuning strategy that also learns from unlabeled data. Scellseg achieves state-of-the-art transferability in average precision and Aggregated Jaccard Index on disparate datasets containing microscopy images at three biological levels, from organelle, cell to organism. Interestingly, when fine-tuning Scellseg, we show that performance plateaued after approximately eight images, implying that a specialist model can be obtained with few manual efforts. For convenient dissemination, we develop a graphical user interface that allows biologists to easily specialize their self-adaptive segmentation model.
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•Scellseg utilizes a style-aware pipeline to be more sensitive to different styles•Scellseg provides 3 benchmarked evaluation datasets with diverse biological levels•Scellseg achieves state-of-the-art transferability on three evaluation datasets•Scellseg explores the effects of pre-trained dataset and shot data
Artificial intelligence; Bioinformatics; Cell biology
Excessive activation of inflammation in chondrocyte has been considered to be a major reason cause of cellular death and degeneration in osteoarthritis (OA) development. The NLRP3 ...inflammasome-mediated pyroptosis pathway is closely related to inflammation regulation. This research was conducted to confirm whether NLRP3 expression and activity are impacted in the development of OA and to detect the role of CY-09, a selective and direct inhibitor of NLRP3 in the in vitro and in vivo models of OA. Our findings corroborated that the expression of NLRP3 is stimulated in OA cartilage. CY-09 can maintain extracellular matrix (ECM) homeostasis and regulate inflammation in TNF-α treated chondrocytes via inhibition of NLRP3 inflammasome-mediated pyroptosis. Moreover, the chondrocyte protective effects of CY-09 were further confirmed in vivo in a DMM-induced OA model. In conclusion, our research indicates that experimental OA activated the NLRP3 activity, and pharmacological inhibition of NLRP3 inflammasome activation by CY-09 protects chondrocytes against inflammation and attenuates OA development.
•NLRP3 inflammasome is activated in osteoarthritis cartilage.•Pharmacological inhibition of NLRP3 inflammasome by CY-09 alleviates inflammation and degeneration in chondrocytes.•CY-09 inhibits chondrocytes pyroptosis and cell death.•CY-09 attenuates mouse osteoarthritis development.
Intervertebral disc degeneration (IDD) is a complicated process that involves both cellular apoptosis and senescence. Metformin has been reported to stimulate autophagy, whereas autophagy is shown to ...protect against apoptosis and senescence. Therefore, we hypothesize that metformin may have therapeutic effect on IDD through autophagy stimulation. The effect of metformin on IDD was investigated both in vitro and in vivo. Our study showed that metformin attenuated cellular apoptosis and senescence induced by tert-butyl hydroperoxide in nucleus pulposus cells. Autophagy, as well as its upstream regulator AMPK, was activated by metformin in nucleus pulposus cells in a dose- and time-dependent manner. Inhibition of autophagy by 3-MA partially abolished the protective effect of metformin against nucleus pulposus cells' apoptosis and senescence, indicating that autophagy was involved in the protective effect of metformin on IDD. In addition, metformin was shown to promote the expression of anabolic genes such as Col2a1 and Acan expression while inhibiting the expression of catabolic genes such as Mmp3 and Adamts5 in nucleus pulposus cells. In vivo study illustrated that metformin treatment could ameliorate IDD in a puncture-induced rat model. Thus, our study showed that metformin could protect nucleus pulposus cells against apoptosis and senescence via autophagy stimulation and ameliorate disc degeneration in vivo, revealing its potential to be a therapeutic agent for IDD.
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It has been suggested that excessive apoptosis in intervertebral disc cells induced by inflammatory cytokines, such as interleukin (IL)-1β, is related to the process of intervertebral ...disc degeneration (IVDD). Hydrogen sulfide (H2S), a gaseous signaling molecule, has drawn attention for its anti-apoptosis role in various pathophysiological processes in degenerative diseases. To date, there has been no investigation of the correlation of H2S production and IVDD or of the effects of H2S on IL-1β-induced apoptosis in nucleus pulposus (NP) cells. Here, we found that the expression levels of cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE), two key enzymes in the generation of H2S, were significantly decreased in human degenerate NP tissues as well as in IL-1β-treated NP cells. NaHS (H2S donor) administration showed a protective effect by inhibiting the endoplasmic reticulum (ER) stress response and mitochondrial dysfunction induced by IL-1β stimulation in vitro, the effect was related to activation of the PI3K/Akt and ERK1/2 signaling pathways. Suppression of these pathways by specific inhibitors, LY294002 and PD98059, partially reduced the protective effect of NaHS. Moreover, in the percutaneous needle puncture disc degeneration rat tail model, disc degeneration was partially reversed by NaHS administration. Taken together, our results suggest that H2S plays a protective role in IVDD and the underlying mechanism involves PI3K/Akt and ERK1/2 signaling pathways-mediated suppression of ER stress and mitochondrial dysfunction in IL-1β-induced NP cells.
Recently, selective inhibition of BET BD2 is emerging as a promising strategy for drug discovery. Despite significant progress in this area, systematic studies of selective BET BD2 inhibitors are ...still few. In this study, we report the discovery of a potent and selective BET BD2 inhibitor BY27 (47). Our high resolution co-crystal structures of 47/BRD2 BD1 and BD2 showed that the triazole group of 47, water molecules, H433 and N429 in BRD2 BD2 established a water-bridged H-bonding network, which is responsible for the observed selectivities. DNA microarray analysis of HepG2 cells treated with 47 or OTX015 demonstrated the transcriptome impact differences between a BET BD2 selective inhibitor and a pan BET inhibitor. In a MV4-11 mouse xenograft model, 47 caused 67% of tumor growth inhibition and was less toxic than a pan BET inhibitor 1 at high doses. We conclude that the improved safety profile of selective BET BD2 inhibitors warrant future studies in BET associated diseases.
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•A potent and selectively inhibitor of BET BD2, BY27, has been synthesized.•Two co-crystal structures of BY27/BRD2 BD1 and BY27/BRD2 BD2 have been obtained.•DNA microarray analysis shows gene expression alteration features of BY27.•BY27 is efficacious in MV4-11 mouse tumor xenograft model.•In vivo data suggested BY27 has better safety profile in mice.
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