scholarly journals Flavopiridol Protects Against Fungal Keratitis by Alleviating Inflammation Through the Promotion of Autophagy

Author(s):  
Lingwen Gu ◽  
Cui Li ◽  
Xudong Peng ◽  
Hao Lin ◽  
Yawen Niu ◽  
...  

Abstract Background: Fungal keratitis is a serious infectious keratopathy related to fungal virulence and excessive inflammatory responses. Autophagy exhibits a potent ability to resolve inflammation during fungal infection. This study aimed to investigate the protective function of flavopiridol in fungal keratitis and explore its effects on autophagy.Methods: A mouse model of fungal keratitis was established and then treated with 5 μM flavopiridol. RAW 264.7 cells were treated with 200 nM flavopiridol before fungal stimulation. The severity of corneal diseases was evaluated by slit-lamp microscopy. The expression levels of cytokines were detected by RT-PCR and ELISA. The protein levels of LC3, Beclin-1 and Atg7 were determined by western blot and immunofluorescence. A Cell Counting Kit-8 assay was used to test cell viability. Autolysosomes were detected by transmission electron microscopy (TEM). An inhibitor of autophagy, 3-methyladenine (3-MA), was used to pretreat RAW 264.7 cells. Phagocytosis of RAW 264.7 cells was evaluated by counting colony forming units. A. fumigatus was incubated with flavopiridol, and the hyphae were stained with calcofluor white. Absorbance assay, crystal violet staining and adherence assay were used to detect the antifungal activity of flavopiridol.Results: Flavopiridol treatment notably reduced corneal opacity and the clinical scores of infected corneas. Compared with DMSO treatment, flavopiridol treatment greatly downregulated IL-1β, IL-6 and TNF-a expression in infected corneas. In RAW 264.7 cells, flavopiridol treatment inhibited IL-1β, IL-6 and TNF-a expression but promoted IL-10 expression. TEM images showed that more autolysosomes were presented in infected corneas and RAW 264.7 cells after flavopiridol treatment than after DMSO treatment. Flavopiridol treatment notably upregulated the protein expression of LC3, Beclin-1 and Atg7 in infected corneas as well as in RAW 264.7 cells. 3-MA pretreatment counteracted the cytokine regulation induced by flavopiridol. Moreover, flavopiridol promoted the phagocytosis of RAW 264.7 cells. Flavopiridol also exhibited antifungal activity by restricting fungal growth and limiting fungal biofilm formation and conidial adhesion. Conclusions: Flavopiridol significantly alleviated the inflammation of fungal keratitis by activating autophagy. In addition, flavopiridol promoted the phagocytosis of RAW 264.7 cells and exhibited antifungal function, indicating the potential therapeutic role of flavopiridol in fungal keratitis.

Gene ◽  
2018 ◽  
Vol 675 ◽  
pp. 94-101 ◽  
Author(s):  
Lin Dong ◽  
Lei Yin ◽  
Rong Chen ◽  
Yuanbin Zhang ◽  
Shiyao Hua ◽  
...  

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 511 ◽  
Author(s):  
K. K. Asanka Sanjeewa ◽  
D. P. Nagahawatta ◽  
Hye-Won Yang ◽  
Jae Young Oh ◽  
Thilina U. Jayawardena ◽  
...  

Inflammation is a well-organized innate immune response that plays an important role during the pathogen attacks and mechanical injuries. The Toll-like receptors (TLR)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a major signal transduction pathway observed in RAW 264.7 macrophages during the inflammatory responses. Here, we investigated the anti-inflammatory effects of Octominin; a bio-active peptide developed from Octopus minor in RAW 264.7 macrophages in vitro. Octominin was found to inhibit lipopolysaccharides (LPS)-stimulated transcriptional activation of NF-κB in RAW 264.7 cells and dose-dependently decreased the mRNA expression levels of TLR4. Specifically, in silico docking results demonstrated that Octominin has a potential to inhibit TLR4 mediated inflammatory responses via blocking formation of TLR4/MD-2/LPS complex. We also demonstrated that Octominin could significantly inhibit LPS-induced secretion of pro-inflammatory cytokine (interleukin-β; IL-1β, IL-6, and tumor necrosis factor-α) and chemokines (CCL3, CCL4, CCL5, and CXCL10) from RAW 264.7 cells. Additionally, Octominin repressed the LPS-induced pro-inflammatory mediators including nitric oxide (NO), prostaglandin E2, inducible NO synthase, and cyclooxygenase 2 in macrophages. These results suggest that Octominin is a potential inhibitor of TLRs/NF-κB signal transduction pathway and is a potential candidate for the treatment of inflammatory diseases.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Dong-Woo Lim ◽  
Hee-Jin Choi ◽  
Sun-Dong Park ◽  
Hyuck Kim ◽  
Ga-Ram Yu ◽  
...  

Despite its deleterious effects on living cells, oxidative stress plays essential roles in normal physiological processes and provides signaling molecules for cell growth, differentiation, and inflammation. Macrophages are equipped with antioxidant mechanisms to cope with intracellular ROS produced during immune response, and Nrf2 (NF-E2-related factor 2)/HO-1 (heme oxygenase-1) pathway is an attractive target due to its protective effect against ROS-induced cell damage in inflamed macrophages. We investigated the effects of ethanol extract of A. villosum (AVEE) on lipopolysaccharide- (LPS-) stimulated inflammatory responses generated via the Nrf2/HO-1 signaling pathway in murine peritoneal macrophages and RAW 264.7 cells. AVEE was found to suppress the NF-κB signaling pathway, thus, to reduce proinflammatory cytokine, nitric oxide, and prostaglandin levels in peritoneal macrophages and Raw 264.7 cells treated with LPS, and to enhance HO-1 expression by activating Nrf2 signaling. Furthermore, these anti-inflammatory effects of AVEE were diminished when cells were pretreated with SnPP (a HO-1 inhibitor). HPLC analysis revealed AVEE contained quercetin, a possible activator of the Nrf2/HO-1 pathway. These results show A. villosum ethanol extract exerts anti-inflammatory effects by activating the Nrf2/HO-1 pathway in LPS-stimulated macrophages.


Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 593
Author(s):  
Shengnan Wang ◽  
Liying Ni ◽  
Xiaoting Fu ◽  
Delin Duan ◽  
Jiachao Xu ◽  
...  

Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated Saccharinajaponica polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells and zebrafish. Its chemical and structural properties were investigated via HPLC, GC, FTIR, and NMR spectroscopy. In vitro experiments demonstrated that LJPS significantly inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and suppressed pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production via the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways in LPS-induced RAW 264.7 cells. Moreover, LJPS showed strong protective effects against LPS-induced inflammatory responses in zebrafish, increasing the survival rate, reducing the heart rate and yolk sac edema size, and inhibiting cell death and the production of intracellular reactive oxygen species (ROS) and NO. Its convenience for large-scale production and significant anti-inflammatory activity indicated the potential application of LJPS in functional foods, cosmetics, and pharmaceutical industries.


2015 ◽  
Vol 29 (2) ◽  
pp. 528-537 ◽  
Author(s):  
Chul Won Lee ◽  
Sang Mi Park ◽  
Rongjie Zhao ◽  
Chu Lee ◽  
Wonjoo Chun ◽  
...  

2008 ◽  
Vol 31 (11) ◽  
pp. 1447-1456 ◽  
Author(s):  
Cheol-Ho Pan ◽  
Eun Sun Kim ◽  
Sang Hoon Jung ◽  
Chu Won Nho ◽  
Jae Kwon Lee

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