ABSTRACT
Aim To investigate whether notoginsenoside Rl (PNS-R1) alleviates allergic rhinitis (AR) through AMP-activated protein kinase (AMPK)/mitochondrial fission critical protein (DRP1) -mediated mitochondrial fission. Methods Different doses of PNSRl were used to treat ovalbumin (OVA) -induced AR model mice,and the inhibitory effect of PNS-R1 on AR was investigated by observing allergic symptoms such as nasal rubbing and sneezing, as well as HE staining of nasal tissues. Serum IgE levels and nasal lavage fluid (NLF) inflammatory cytokine levels were detected by enzyme-linked immunosorbent assay (ELISA) and apoptosis-related proteins were detected by Western blot. In vitro human nasal epithelial cells (HNEpC) were stimulated with IL-13 to observe apoptosis, mitochondrial membrane potential, cellular ROS and mitochondrial ROS production, as well as the expression levels of AMPK/DRP1, expression levels of the TXNIP/NLRP3 inflammasomes and the translocation of DRP1. Results PNS-R1 attenuated allergic symptoms in AR mice, HE staining reduced inflammatory cells and reduced the levels of OVA-specific IgE in serum, and the levels of IL-4, IL-6, and IL-8 in NLF. PNS-R1 attenuated the apoptosis and ROS production of nasal epithelial cells in AR. In vitro PNS-R1 could up-regulate mitochondrial membrane potential after IL-13 stimulation, reduce ROS and mtROS production, the proportion of apoptotic positive cells, and reduce cleaved caspase-3, Bax, and up-regulate Bcl-2 expression, down-regulate DRP1 phosphorylation (Ser 616) and DRP1 translocation at the mitochondrial membrane in an AMPK-dependent manner, reducing TXNIP/NLRP3 expression. Conclusions PNS-R1 can protect mitochondrial integrity by inhibiting the AMPK/DRP1 signaling axis and its subsequent TXNIP/NLRP3 signaling axis,thereby alleviating rhinitis in AR mice.
ABSTRACT
We investigated whether Panax notoginseng saponin (PNS-R1) attenuates allergic rhinitis (AR) through AMPK/Drp1-mediated mitochondrial fission. AR model was established in mice by Ovalbumin (OVA). In vitro, human nasal epithelial cells (HNEpCs) were stimulated using recombinant human interleukin 13 (IL-13). PNS-R1 was administrated in vivo and in vitro. Then, HE staining of nasal tissue, ELISA detection of immunoglobulin E (IgE) and proinflammatory cytokine levels in serum and nasal lavage fluid, flow cytometry analysis of Th1/Th2 ratio and apoptosis, TUNEL staining, Western blot, detection of reactive oxygen species (ROS) and mitochondrial ROS, immunofluorescence analysis of Tom20 and mitochondrial fission protein Drp1 co-localization, and mitochondrial membrane potential detection, were performed. PNS-R1 attenuated allergic symptoms in AR mice, decreased OVA-specific IgE, IL-4, IL-6, IL-8, IL-13, and TNF-α levels, and restored the Th1/Th2 imbalance. Meanwhile, we found that PNS-R1 treatment significantly reduced apoptosis, ROS production, and co-localization of Tom20 and Drp1 in the nasal epithelium of AR mice. In vitro, we found that PNS-R1 upregulated mitochondrial membrane potential and reduced ROS and mitochondrial ROS production as well as Cleaved-caspase-3/9, Bax, Cyt-c, Apaf-1 expression and mitochondrial fission. Mechanistically, we found that PNS-R1 downregulated Drp1 phosphorylation (Ser 616) and Drp1 translocation in an AMPK-dependent manner, promoted MFN2 expression, and reduced TXNIP, NLRP3, Caspase-1, and IL-1ß expression. PNS-R1 may protect mitochondrial integrity by inhibiting AMPK/Drp1 and TXNIP/NLRP3 signaling pathway, thereby alleviating AR symptoms in mice. PNS-R1 may have great potential as a therapeutic agent for AR.
Subject(s)
Panax notoginseng , Rhinitis, Allergic , Saponins , AMP-Activated Protein Kinases , Animals , Disease Models, Animal , Humans , Immunoglobulin E , Interleukin-13/therapeutic use , Mice , Mitochondrial Dynamics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Ovalbumin , Panax notoginseng/metabolism , Reactive Oxygen Species/metabolism , Rhinitis, Allergic/chemically induced , Rhinitis, Allergic/drug therapy , Saponins/pharmacology , Saponins/therapeutic useABSTRACT
Dexamethasone (Dex) are widely used for the treatment of asthma. However, they may cause apoptosis of bronchial epithelial cells and delay the recovery of asthma. Therefore, it is an urgent problem to find effective drugs to reduce this side effects. Panax notoginseng saponins R1 (PNS-R1) is known to exhibit anti-oxidative and anti-apoptotic properties in many diseases. We aim to investigate whether PNS-R1 can reduce Dex-induced apoptosis in bronchial epithelial cells. In this study, the anti-apoptotic effects of PNS-R1 were investigated by conducting in vitro and in vivo. Annexin V-FITC/PI staining flow cytometry analysis and TUNEL assay were conducted to detect apoptotic cells. Mitochondrial membrane potential was detected by JC-1 analysis. Western blotting and immunohistochemical analysis were conducted to measure caspase3, Bcl-2, Bax, Cyt-c, Apaf-1, cleaved-caspase3 and cleaved-caspase9 levels in lung tissues and 16HBE cells. Our findings demonstrated that Dex could induce apoptosis of bronchial epithelial cells and upregulate caspase3 expression of lung tissues. Western blot showed that Dex increased Bax, Cyt-c, Apaf-1, cleaved-caspase9, cleaved-caspase3 expression and decreased Bcl-2 expression. PNS-R1 could suppress Dex-induced apoptosis of bronchial epithelial cells by inhibiting Bax, Cyt-c, Apaf-1, cleaved-caspase9, cleaved-caspase3 expression and upregulating Bcl-2 expression. Flow cytometry analysis showed PNS-R1 alleviated JC-1 positive cells induced by Dex in 16HBE cells. These results showed that PNS-R1 alleviated Dex-induced apoptosis in bronchial epithelial cells by inhibition of mitochondrial apoptosis pathway. Furthermore, our findings highlighted the potential use of PNS-R1 as an adjuvant drug to treat asthma.