scholarly journals Inhibition of Autophagy Prevents Panax Notoginseng Saponins (PNS) Protection on Cardiac Myocytes Against Endoplasmic Reticulum (ER) Stress-Induced Mitochondrial Injury, Ca2+ Homeostasis and Associated Apoptosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Chen ◽  
Li Li ◽  
Xueyang Bai ◽  
Lili Xiao ◽  
Jiahong Shangguan ◽  
...  

Endoplasmic reticulum (ER) stress is often closely linked to autophagy, hypoxia signaling, mitochondrial biogenesis and reactive oxygen species (ROS) responses. Understanding the interaction between ER stress, mitochondrial function and autophagy is of great importance to provide new mechanisms for the pathology, prevention and treatment of cardiovascular diseases. Our previous study has reported that Panax notoginseng saponins (PNS) protection against thapsigargin (TG)-induced ER stress response and associated cell apoptosis in cardiac myocytes is calcium dependent and mediated by ER Ca2+ release through RyR2. However, whether its protection upon ER stress and associated apoptosis is related to mitochondrial function and autophagy remains largely unknown. Here, we investigated the roles of PNS played in TG-induced mitochondrial function, ROS accumulation and autophagy. We also assessed its effects on Ca2+ homeostasis, ER stress response and associated cell death in the presence of autophagy inhibition. PNS-pretreated primary cultured neonatal rat cardiomyocytes were stimulated with TG to induce ER stress response. Mitochondrial potential (Δψm) was measured by JC-1. The general and mitochondrial ROS were measured by DCFH-DA and MitoSOX Red, respectively. Autophagy was evaluated by immunofluorescence of LC3, and immunoblots of LC3, p62, ATG7 and PINK1. In addition, mRFP-GFP-LC3 labeling was used to assess the autophagic influx. SiATG7 transfected H9c2 cells were generated to inhibit autophagy. Cytosolic and ER Ca2+ dynamics were investigated by calcium imaging. RyR2 oxidation was tested by oxyblot. Cell viability was examined by TUNEL assay. ER stress response and cell apoptosis were detected by immunoblots of BiP, CHOP, Cleaved Caspase-3 and Caspase-12. The results demonstrated that firstly, PNS protects against TG-induced mitochondrial injury and ROS accumulation. Secondly, PNS enhances autophagy in TG-induced cardiac myocytes. Thirdly, inhibition of autophagy diminishes PNS prevention of TG-induced mitochondrial injury, ROS accumulation and disruption of Ca2+ homeostasis. Last but not least, inhibition of autophagy abolishes PNS protection against TG-induced ER stress response and associated apoptosis. In summary, PNS protection against ER stress response and associated apoptosis is related to the regulation of mitochondrial injury and ROS overproduction via modulation of autophagy. These data provide new insights for molecular mechanisms of PNS as a potential preventive approach to the management of cardiovascular diseases.

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Oanh H. Pham ◽  
Bokyung Lee ◽  
Jasmine Labuda ◽  
A. Marijke Keestra-Gounder ◽  
Mariana X. Byndloss ◽  
...  

ABSTRACT The inflammatory response to Chlamydia infection is likely to be multifactorial and involve a variety of ligand-dependent and -independent recognition pathways. We previously reported the presence of NOD1/NOD2-dependent endoplasmic reticulum (ER) stress-induced inflammation during Chlamydia muridarum infection in vitro, but the relevance of this finding to an in vivo context is unclear. Here, we examined the ER stress response to in vivo Chlamydia infection. The induction of interleukin 6 (IL-6) production after systemic Chlamydia infection correlated with expression of ER stress response genes. Furthermore, when tauroursodeoxycholate (TUDCA) was used to inhibit the ER stress response, an increased bacterial burden was detected, suggesting that ER stress-driven inflammation can contribute to systemic bacterial clearance. Mice lacking both NOD1 and NOD2 or RIP2 exhibited slightly higher systemic bacterial burdens after infection with Chlamydia. Overall, these data suggest a model where RIP2 and NOD1/NOD2 proteins link ER stress responses with the induction of Chlamydia-specific inflammatory responses. IMPORTANCE Understanding the initiation of the inflammatory response during Chlamydia infection is of public health importance given the impact of this disease on young women in the United States. Many young women are chronically infected with Chlamydia but are asymptomatic and therefore do not seek treatment, leaving them at risk of long-term reproductive harm due to inflammation in response to infection. Our manuscript explores the role of the endoplasmic reticulum stress response pathway initiated by an innate receptor in the development of this inflammation.


2020 ◽  
Vol 30 (9) ◽  
pp. 672-675 ◽  
Author(s):  
Kashi Raj Bhattarai ◽  
Manoj Chaudhary ◽  
Hyung-Ryong Kim ◽  
Han-Jung Chae

Author(s):  
Fernanda L.B. Mügge ◽  
Aristóbolo M. Silva

AbstractOver the past decade, a handful of evidence has been provided that nonsteroidal anti-inflammatory drugs (NSAIDs) display effects on the homeostasis of the endoplasmic reticulum (ER). Their uptake into cells will eventually lead to activation or inhibition of key molecules that mediate ER stress responses, raising not only a growing interest for a pharmacological target in ER stress responses but also important questions how the ER-stress mediated effects induced by NSAIDs could be therapeutically advantageous or not. We review here the toxicity effects and therapeutic applications of NSAIDs involving the three majors ER stress arms namely PERK, IRE1, and ATF6. First, we provide brief introduction on the well-established and characterized downstream events mediated by these ER stress players, followed by presentation of the NSAIDs compounds and mode of action, and finally their effects on ER stress response. NSAIDs present promising drug agents targeting the components of ER stress in different aspects of cancer and other diseases, but a better comprehension of the mechanisms underlying their benefits and harms will certainly pave the road for several diseases’ therapy.


2008 ◽  
Vol 283 (25) ◽  
pp. 17020-17029 ◽  
Author(s):  
Yukihiro Yamaguchi ◽  
Dennis Larkin ◽  
Roberto Lara-Lemus ◽  
Jose Ramos-Castañeda ◽  
Ming Liu ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ken-ichiro Tanaka ◽  
Misato Kasai ◽  
Mikako Shimoda ◽  
Ayane Shimizu ◽  
Maho Kubota ◽  
...  

Trace metals such as zinc (Zn), copper (Cu), and nickel (Ni) play important roles in various physiological functions such as immunity, cell division, and protein synthesis in a wide variety of species. However, excessive amounts of these trace metals cause disorders in various tissues of the central nervous system, respiratory system, and other vital organs. Our previous analysis focusing on neurotoxicity resulting from interactions between Zn and Cu revealed that Cu2+ markedly enhances Zn2+-induced neuronal cell death by activating oxidative stress and the endoplasmic reticulum (ER) stress response. However, neurotoxicity arising from interactions between zinc and metals other than copper has not been examined. Thus, in the current study, we examined the effect of Ni2+ on Zn2+-induced neurotoxicity. Initially, we found that nontoxic concentrations (0–60 μM) of Ni2+ enhance Zn2+-induced neurotoxicity in an immortalized hypothalamic neuronal cell line (GT1-7) in a dose-dependent manner. Next, we analyzed the mechanism enhancing neuronal cell death, focusing on the ER stress response. Our results revealed that Ni2+ treatment significantly primed the Zn2+-induced ER stress response, especially expression of the CCAAT-enhancer-binding protein homologous protein (CHOP). Finally, we examined the effect of carnosine (an endogenous peptide) on Ni2+/Zn2+-induced neurotoxicity and found that carnosine attenuated Ni2+/Zn2+-induced neuronal cell death and ER stress occurring before cell death. Based on our results, Ni2+ treatment significantly enhances Zn2+-induced neuronal cell death by priming the ER stress response. Thus, compounds that decrease the ER stress response, such as carnosine, may be beneficial for neurological diseases.


2010 ◽  
Vol 340 (2) ◽  
pp. 335-346 ◽  
Author(s):  
Ihsane Marhfour ◽  
Jean-Christophe Jonas ◽  
Joëlle Marchandise ◽  
Alberte Lefevre ◽  
Jacques Rahier ◽  
...  

2012 ◽  
Vol 303 (1) ◽  
pp. G54-G59 ◽  
Author(s):  
Anne S. Henkel ◽  
Amanda M. Dewey ◽  
Kristy A. Anderson ◽  
Shantel Olivares ◽  
Richard M. Green

Endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of nonalcoholic steatohepatitis. The ER stress response is activated in the livers of mice fed a methionine- and choline-deficient (MCD) diet, yet the role of ER stress in the pathogenesis of MCD diet-induced steatohepatitis is unknown. Using chemical chaperones on hepatic steatosis and markers of inflammation and fibrosis in mice fed a MCD diet, we aim to determine the effects of reducing ER stress. C57BL/6J mice were fed a MCD diet with or without the ER chemical chaperones 4-phenylbutyric acid (PBA) and tauroursodeoxycholic acid (TUDCA) for 2 wk. TUDCA and PBA effectively attenuated the ER stress response in MCD diet-fed mice, as evidenced by reduced protein levels of phosphorylated eukaryotic initiation factor 2α and phosphorylated JNK and suppression of mRNA levels of CCAAT/enhancer binding protein homologous protein, glucose-regulated protein 78 kDa, and X-box binding protein 1. However, PBA and TUDCA did not decrease MCD diet-induced hepatic steatosis. MCD diet-induced hepatic inflammation, as evidenced by increased plasma alanine aminotransferase and induction of hepatic TNFα expression, was also not reduced by PBA or TUDCA. PBA and TUDCA did not attenuate MCD diet-induced upregulation of the fibrosis-associated genes tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-9. ER chemical chaperones reduce MCD diet-induced ER stress, yet they do not improve MCD diet-induced hepatic steatosis, inflammation, or activation of genes associated with fibrosis. These data suggest that although the ER stress response is activated by the MCD diet, it does not have a primary role in the pathogenesis of MCD diet-induced steatohepatitis.


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