scholarly journals IL-6 Promotes the Proliferation and Immunosuppressive Function of Myeloid-Derived Suppressor Cells via the MAPK Signaling Pathway in Bladder Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Zhong Zheng ◽  
Xinyi Zheng ◽  
Yiwen Zhu ◽  
Zhixian Yao ◽  
Weiguang Zhao ◽  
...  

Muscle-invasive bladder cancer (MIBC) is characterized by a highly complex immune environment, which is not well understood. Interleukin-6 (IL-6) is generated and secreted by multifarious types of cells, including tumor cells. This study was aimed at demonstrating that the levels of IL-6 and the number of myeloid-derived suppressor cells (MDSCs), with a positive correlation between them, increased in MIBC tissues, promoting MIBC cell proliferation, especially in patients with recurrence. In coculture analysis, MDSCs, with the stimulation of IL-6, could significantly lower the proliferation ability of CD4+ or CD8+ T lymphocytes. Further, this study demonstrated that IL-6 could upregulate the mitogen-activated protein kinase (MAPK) signaling pathway in MDSCs. The MAPK signaling inhibitor, aloesin, partially reversed the effects of IL-6 on MDSCs. These data suggested that IL-6 promoted MIBC progression by not only accelerating proliferation but also improving the immune suppression ability of MDSCs through activating the MAPK signaling pathway.

2020 ◽  
Vol 10 (2) ◽  
pp. 163-168
Author(s):  
Sheng Wang ◽  
Zhonghan Min ◽  
Run Gu ◽  
Zhongwei Yu ◽  
Pingquan Chen ◽  
...  

During OP bone metabolism, activated MAPK signaling can promote the proliferation and differentiation of osteoclasts. miRNAs involve in bone diseases. Our study aimed to evaluate miR-200c’s effect on ERK/MAPK signaling pathway in OP. miR-200c expression in OP mice and normal mice was detected by qPCR. BMSCs were cultured and transfected with siRNA to establish a miR-200c knockout model. Flow cytometry was used to detect cell apoptosis and ERK/MAPK signaling protein was detected by Western blot. miR-200c expression in OP mice was significantly lower than that in normal mice. Bone marrow mesenchymal stem cells (BMSCs) contain a large amount of siRNA particles under a fluorescence microscope. siRNA transfection can effectively inhibit miR-200c expression without difference of BMSCs apoptosis between miR-200c siRNA group and NC group. However, ERK1/2 and P38 expression in experimental group were significantly higher than those in NC siRNA group with reduced ALP activity. In addition, BMSCs osteogenic differentiation was further diminished when miR-200c expression was inhibited. miR-200c expression is lower in OP mice. miR-200c siRNA inhibits BMSCs osteogenic differentiation via ERK/MAPK signaling, thereby promoting OP progression.


2019 ◽  
Author(s):  
Yeojin Hong ◽  
Thu Thao Pham ◽  
Jiae Lee ◽  
Hyun S. Lillehoj ◽  
Yeong Ho Hong

Abstract Background Defensins are antimicrobial peptides composed of three conserved disulfide bridges, a β-sheet, and both hydrophobic and cationic amino acids. In this study, we aimed to demonstrate the immunomodulation role of avian β-defensin 8 (AvBD8) in a chicken macrophage cell line.Results Chicken AvBD8 stimulated the expression of proinflammatory cytokines (interleukin (IL)-1β, interferon-γ, and IL-12p40) and chemokines (CCL4, CXCL13, and CCL20) in macrophages. Furthermore, by western blotting and immunocytochemistry, we confirmed that AvBD8 activated the mitogen-activated protein kinase (MAPK) signaling pathway via extracellular regulated kinases 1/2 (ERK1/2) and p38 signaling molecules.Conclusion Overall, AvBD8 plays a crucial role in host defense as not only an antimicrobial peptide, but also an immunomodulator by activating the MAPK signaling pathway and inducing the expression of proinflammatory cytokines and chemokines.


mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjun Sun ◽  
Ying Yu ◽  
Jiao Chen ◽  
Bin Yu ◽  
Tianpeng Chen ◽  
...  

ABSTRACT Light is an important signal source in nature, which regulates the physiological cycle, morphogenetic pathways, and secondary metabolites of fungi. As an external pressure on Aspergillus niger, light signaling transmits stress signals into the cell via the mitogen-activated protein kinase (MAPK) signaling pathway. Studying the effect of light on the biofilm of A. niger will provide a theoretical basis for light in the cultivation of filamentous fungi and industrial applications. Here, the characterization of A. niger biofilm under different light intensities confirmed the effects of light signaling. Our results indicated that A. niger intensely accumulated protective mycelial melanin under light illumination. We also discovered that the RlmA transcription factor in the MAPK signaling pathway is activated by light signaling to promote the synthesis of melanin, chitin, and other exopolysaccharides. However, the importance of melanin to A. niger biofilm is rarely reported; therefore, we knocked out key genes of the melanin biosynthetic pathway—Abr1 and Ayg1. Changes in hydrophobicity and electrostatic forces resulted in the decrease of biofilm caused by the decrease of melanin in mutants. IMPORTANCE As an important industrial filamentous fungus, Aspergillus niger can perceive light. The link between light signaling and A. niger biofilm is worthy of further study since reports are lacking in this area. This study found that light signaling promotes biofilm production in A. niger, wherein melanin plays an important role. It was further discovered that the RlmA transcription factor in the mitogen-activated protein kinase (MAPK) signaling pathway was mediated by light signaling to promote the synthesis of melanin and extracellular polysaccharides. These findings set the stage for light signal regulation of biofilm in filamentous fungi and provide a theoretical basis for the development of a new light-controlled biofilm method to improve biofilm-based industrial fermentation.


Endocrinology ◽  
2001 ◽  
Vol 142 (4) ◽  
pp. 1554-1560 ◽  
Author(s):  
Chen-Jei Tai ◽  
Sung Keun Kang ◽  
Chii-Ruey Tzeng ◽  
Peter C. K. Leung

Abstract ATP has been shown to activate the phospholipase C/diacylglycerol/protein kinase C (PKC) pathway. However, little is known about the downstream signaling events. The present study was designed to examine the effect of ATP on activation of the mitogen-activated protein kinase (MAPK) signaling pathway and its physiological role in human granulosa-luteal cells. Western blot analysis, using a monoclonal antibody that detected the phosphorylated forms of extracellular signal-regulated kinase-1 and -2 (p42mapk and p44 mapk, respectively), demonstrated that ATP activated MAPK in a dose- and time-dependent manner. Treatment of the cells with suramin (a P2 purinoceptor antagonist), neomycin (a phospholipase C inhibitor), staurosporin (a PKC inhibitor), or PD98059 (an MAPK/ERK kinase inhibitor) significantly attenuated the ATP-induced activation of MAPK. In contrast, ATP-induced MAPK activation was not significantly affected by pertussis toxin (a Gi inhibitor). To examine the role of Gs protein, the intracellular cAMP level was determined after treatment with ATP or hCG. No significant elevation of intracellular cAMP was noted after ATP treatment. To determine the role of MAPK in steroidogenesis, human granulosa-luteal cells were treated with ATP, hCG, or ATP plus hCG in the presence or absence of PD98059. RIA revealed that ATP alone did not significantly affect the basal progesterone concentration. However, hCG-induced progesterone production was reduced by ATP treatment. PD98059 reversed the inhibitory effect of ATP on hCG-induced progesterone production. To our knowledge, this is the first demonstration of ATP-induced activation of the MAPK signaling pathway in the human ovary. These results support the idea that the MAPK signaling pathway is involved in mediating ATP actions in the human ovary.


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