scholarly journals 5-Aminolevulinic Acid Attenuates Glucose-Regulated Protein 78 Expression and Hepatocyte Lipoapoptosis via Heme Oxygenase-1 Induction

2021 ◽  
Vol 22 (21) ◽  
pp. 11405
Author(s):  
Takaaki Hashimoto ◽  
Takaaki Sugihara ◽  
Tsutomu Kanda ◽  
Tomoaki Takata ◽  
Hajime Isomoto

Endoplasmic reticulum (ER) stress plays a pivotal role in the progression of steatohepatitis. 5-aminolevulinic acid (5-ALA), a precursor in the heme biosynthetic pathway, has recently been reported to induce heme oxygenase (HO)-1. HO-1 exerts important cytoprotective actions. In this study, we aimed to explore the therapeutic potential of 5-ALA on palmitate-induced ER stress and lipoapoptosis. Huh-7 cells were treated with palmitic acid (PA) (800 μM) to induce steatosis for eight hours. Steatosis was evaluated by Lipi-green staining. 5-ALA (200 μM) was added with PA. The gene expression levels of the nuclear factor erythroid 2–related factor 2 (NRF2), HO-1, Glucose-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), PKR-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), C/EBP homologous protein (CHOP), and B-cell lymphoma 2 (BCL-2) were evaluated by RT-PCR. Caspase-3/7 activity was evaluated by fluorescein active Caspase-3/7 staining. Cell death was evaluated by Annexin V/SYTOX green staining. PA significantly induced steatosis and increased GRP78 expression in Huh-7 cells. 5-ALA significantly induced HO-1 and decreased GRP78 expression. ATF6 was subsequently decreased. However, NRF2 and CHOP expression were not altered. Anti-apoptotic BCL-2 expression significantly increased, and Caspase 3/7 activity and cell death also decreased. 5-ALA has a therapeutic potential on hepatic steatosis by suppressing ER stress and lipoapoptosis by attenuating GRP78 via HO-1 induction.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Son ◽  
Ju Hwan Lee ◽  
Yong-Kwan Cheong ◽  
Hun-Taeg Chung ◽  
Hyun-Ock Pae

Although there is a therapeutic treatment to combat diabetes, the identification of agents that may deal with its more serious aspects is an important medical field for research. Diabetes, which contributes to the risk of cardiovascular disease, is associated with a low-grade chronic inflammation (inflammatory stress), oxidative stress, and endoplasmic reticulum (ER) stress. Because the integration of these stresses is critical to the pathogenesis of diabetes, agents and cellular molecules that can modulate these stress responses are emerging as potential targets for intervention and treatment of diabetic diseases. It has been recognized that heme oxygenase-1 (HO-1) plays an important role in cellular protection. Because HO-1 can reduce oxidative stress, inflammatory stress, and ER stress, in part by exerting antioxidant, anti-inflammatory, and antiapoptotic effects, HO-1 has been suggested to play important roles in pathogenesis of diabetes. In the present review, we will explore our current understanding of the protective mechanisms of HO-1 in diabetes and present some emerging therapeutic options for HO-1 expression in treating diabetic diseases, together with the therapeutic potential of curcumin analogues that have their ability to induce HO-1 expression.


2020 ◽  
Vol 19 (8) ◽  
pp. 1685-1691
Author(s):  
Zhongkui Li ◽  
Lufang Gao ◽  
Daokang Xiang ◽  
Wenbo Liu

Purpose: To investigate the myocardial protective effect of huperzine A (HPA), a sesquiterpene alkaloid, in a rat model of isoproterenol (ISP)- provoked MI and ER stress.Methods: Three groups of rats were used: control, ISP and ISP+HPA groups. The following indices were assayed using standard protocols: oxidative stress parameters, including NADPH oxidase 4 (NOX4), reactive oxygen species (ROS), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1); indices of calcium homeostasis, namely, sarcoplasmic and endoplasmic reticulum calcium ATPase isoform 2a (SERCA2a); ER stress parameters, viz, protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), glucose-regulated protein 78 (GRP78), and C/EBP homologous protein (CHOP); and indices of apoptosis, i.e., B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-12].Results: Oxidative/ER stress and cardiomyocyte apoptosis were up-modulated (p < 0.05), while SERCA2a, a key calcium handling channel, was downmodulated in the ISP group (p < 0.05). In contrast, HPA treatment ameliorated these ISP-induced myocardial aberrations. (p < 0.05).Conclusion: These results indicate that HPA might be a potential therapeutic candidate for MI and associated cardiac problems. Keywords: Caspase-12, ER stress, Huperzine A, Myocardial infarction, SERCA2a


2005 ◽  
Vol 25 (3) ◽  
pp. 358-370 ◽  
Author(s):  
Koji Aoyama ◽  
David M Burns ◽  
Sang Won Suh ◽  
Philippe Garnier ◽  
Yasuhiko Matsumori ◽  
...  

Endoplasmic reticulum (ER) stress leads to activation of caspase-12, which in turn can lead to activation of caspase-3 and cell death. Here we report that transient acidosis induces ER stress and caspase-12-mediated cell death in mouse astrocytes. After a 3-hour incubation at pH 6.0, astrocytes exhibited delayed cell death associated with nuclear condensation and fragmentation. Cell death was reduced by the protein synthesis inhibitor cycloheximide, further suggesting an active cell death program. Acidosis increased the expression of the ER chaperone protein GRP-78, indicative of ER stress. Acidosis also increased caspase-12 mRNA expression, caspase-12 protein expression, cleavage of caspase-12 to its active form, and activation of caspase-3. Each of these effects was suppressed in astrocytes pretreated with caspase-12 antisense phosphorodiamidate morpholino oligodeoxynucleotides (PMOs). Caspase-12 antisense PMOs also reduced the cell death induced by acidosis. Immunoprecipitation studies showed dissociation of both caspase-12 and Ire1-α from GRP-78, thereby suggesting a mechanism by which acidosis can initiate the ER stress response. To evaluate caspase-12 activation in vivo, rats were subjected to middle cerebral artery ischemia–reperfusion. Immunostaining of brain sections harvested 24 hours later showed increased caspase-12 expression and nuclear condensation in astrocytes of the periinfarct region exposed to acidosis during ischemia. These findings suggest that acidosis induces ER stress and caspase-12 activation, and that these changes may contribute to delayed cell death after ischemia.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dávid Pethő ◽  
Zoltán Hendrik ◽  
Annamária Nagy ◽  
Lívia Beke ◽  
Andreas Patsalos ◽  
...  

AbstractHemorrhage and hemolysis with subsequent heme release are implicated in many pathologies. Endothelial cells (ECs) encounter large amount of free heme after hemolysis and are at risk of damage from exogenous heme. Here we show that hemorrhage aggravates endoplasmic reticulum (ER) stress in human carotid artery plaques compared to healthy controls or atheromas without hemorrhage as demonstrated by RNA sequencing and immunohistochemistry. In EC cultures, heme also induces ER stress. In contrast, if cultured ECs are pulsed with heme arginate, cells become resistant to heme-induced ER (HIER) stress that is associated with heme oxygenase-1 (HO-1) and ferritin induction. Knocking down HO-1, HO-2, biliverdin reductase, and ferritin show that HO-1 is the ultimate cytoprotectant in acute HIER stress. Carbon monoxide-releasing molecules (CORMs) but not bilirubin protects cultured ECs from HIER stress via HO-1 induction, at least in part. Knocking down HO-1 aggravates heme-induced cell death that cannot be counterbalanced with any known cell death inhibitors. We conclude that endothelium and perhaps other cell types can be protected from HIER stress by induction of HO-1, and heme-induced cell death occurs via HIER stress that is potentially involved in the pathogenesis of diverse pathologies with hemolysis and hemorrhage including atherosclerosis.


2016 ◽  
Vol 22 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Zhi-Yu Shi ◽  
Yue Liu ◽  
Li Dong ◽  
Bo Zhang ◽  
Meng Zhao ◽  
...  

Objectives: The endoplasmic reticulum (ER) stress-induced apoptotic pathway is associated with the development of acute myocardial infarction (AMI). Cortistatin (CST) is a novel bioactive peptide that inhibits apoptosis-related injury. Therefore, we investigated the cardioprotective effects and potential mechanisms of CST in a rat model of AMI. Methods: Male Wistar rats were randomly divided into sham, AMI, and AMI + CST groups. Cardiac function and the degree of infarction were evaluated by echocardiography, cardiac troponin I activity, and 2,3,5-triphenyl-2H-tetrazolium chloride staining after 7 days. The expression of CST, ER stress markers, and apoptotic markers was examined using immunohistochemistry and Western blotting. Results: Compared to the AMI group, the AMI + CST group exhibited markedly better cardiac function and a lower degree of infarction. Electron microscopy and terminal deoxynucleotidyl transferase dUTP nick end labeling confirmed that myocardial apoptosis occurred after AMI. Cortistatin treatment reduced the expression of caspase 3, cleaved caspase 3, and Bax (proapoptotic proteins) and promoted the expression of Bcl-2 (antiapoptotic protein). In addition, the reduced expression of glucose-regulated protein 94 (GRP94), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding proteins homologous protein, and caspase 12 indicated that ER stress and the apoptotic pathway associated with ER stress were suppressed. Conclusions: Exogenous CST has a notable cardioprotective effect after AMI in a rat model in that it improves cardiac function by suppressing ER stress and myocardial apoptosis.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yukari Mae ◽  
Yui Kobayashi ◽  
Tomoaki Takata ◽  
Kohshiro Hosokawa ◽  
Takaaki Sugihara ◽  
...  

Abstract Background and Aims A growing number of evidence indicates the association with dyslipidemia and the progression of chronic kidney disease. Endoplasmic reticulum (ER) stress and apoptosis in renal tubule are suggested to be linked to the pathophysiology of toxic lipid-induced kidney injury. 5-aminolevulinic acid (ALA) is a precursor of heme oxygenase (HO)-1, which plays an important role in protecting cells from various stresses. In the present study, we aimed to investigate the therapeutic effect of ALA, on toxic lipid-induced ER stress and apoptosis in the renal tubule. Method Renal proximal tubular epithelial cells (RPTECs) were treated with palmitic acid to induce ER stress and apoptosis. ALA was also added with palmitic acid (PA). The gene and protein expressions of NF E2-related factor 2, HO-1, glucose-regulated protein (GRP)78, and C/EBP-homologous protein (CHOP) were quantified. Apoptotic cells were evaluated by caspase-3/7 assay. An HO-1 inhibitor, Zn-protoporphyrin IX, was added to investigate the involvement of HO-1 in ALA-mediated therapeutic effect on the ER stress and apoptosis. Results The expressions of GRP78 and CHOP increased in cells treated with PA. Apoptotic signals also increased with PA treatment. ALA induced a significant increase in the HO-1 expression and that led to the suppression of ER stress response. Apoptotic signals in PA-treated cells also decreased with ALA and the effect of ALA disappeared when combined with Zn-protoporphyrin IX. Conclusion PA-induced ER stress and apoptosis in RPTECs. ALA has a therapeutic effect by suppressing ER stress, possibly through HO-1 induction.


2019 ◽  
Vol 20 (23) ◽  
pp. 5896 ◽  
Author(s):  
Kishino ◽  
Hayashi ◽  
Maeda ◽  
Jike ◽  
Hidai ◽  
...  

The aim of this study is to elucidate the detailed mechanism of endoplasmic reticulum (ER) stress-induced auditory cell death based on the function of the initiator caspases and molecular complex of necroptosis. Here, we demonstrated that ER stress initiates not only caspase-9-dependent intrinsic apoptosis along with caspase-3, but also receptor-interacting serine/threonine kinase (RIPK)1-dependent necroptosis in auditory cells. We observed the ultrastructural characteristics of both apoptosis and necroptosis in tunicamycin-treated cells under transmission electron microscopy (TEM). We demonstrated that ER stress-induced necroptosis was dependent on the induction of RIPK1, negatively regulated by caspase-8 in auditory cells. Our data suggested that ER stress-induced intrinsic apoptosis depends on the induction of caspase-9 along with caspase-3 in auditory cells. The results of this study reveal that necroptosis could exist for the alternative backup cell death route of apoptosis in auditory cells under ER stress. Interestingly, our data results in a surge in the recognition that therapies aimed at the inner ear protection effect by caspase inhibitors like zVAD-fmk might arrest apoptosis but can also have the unanticipated effect of promoting necroptosis. Thus, RIPK1-dependent necroptosis would be a new therapeutic target for the treatment of sensorineural hearing loss due to ER stress.


2019 ◽  
Vol 14 (12) ◽  
pp. 1934578X1989668 ◽  
Author(s):  
Phil Jun Lee ◽  
Hye-Jin Park ◽  
Hee Min Yoo ◽  
Namki Cho

A key pathologic event in neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, is endoplasmic reticulum (ER) stress-induced neuronal cell death. ER stress-induced generation of reactive oxygen species (ROS) has been implicated in neurological disease processes. Betulin is one of the major triterpenoids found in Betula platyphylla that possesses several biological properties, including cytoprotective and antioxidative effects. Therefore, we investigated whether betulin could prevent ER stress-induced neurotoxicity in HT-22 hippocampal neuronal cells. We observed that betulin reduced the thapsigargin (TG, an ER stress inducer)-induced apoptosis of HT-22 cells. Moreover, the cytoprotective effects of betulin were comparable to those of tauroursodeoxycholic acid, a potent ER stress-reducing agent. In our study, we confirmed that the ER stress-induced accumulation of ROS plays an important role in HT-22 cell death. Betulin also displayed cytoprotective effects in TG-injured HT-22 cells by reducing ROS generation; these results were comparable to those for N-acetyl-L-cysteine, a known ROS inhibitor. In addition, SnPP, a heme oxygenase-1 (HO-1) inhibitor significantly blocked the cytoprotective effects and ROS scavenging activity of betulin. Based on these results, we believe that betulin-mediated induction of HO-1 may contribute to the neuroprotective effects against ER stress in HT-22 hippocampal cells. We also found that betulin significantly inhibited the TG-induced expression of CHOP and caspase-12. These results demonstrated that betulin could serve as a potential therapeutic agent against ER stress-induced neurodegenerative diseases.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2952 ◽  
Author(s):  
Snehal M. Gaikwad ◽  
Zaw Phyo ◽  
Anaisa Quintanilla Arteaga ◽  
Sayeh Gorjifard ◽  
David R. Calabrese ◽  
...  

New approaches to target MYC include the stabilization of a guanine-rich, G-quadruplex (G4) tertiary DNA structure in the NHE III region of its promoter. Recent screening of a small molecule microarray platform identified a benzofuran, D089, that can stabilize the MYC G4 and inhibit its transcription. D089 induced both dose- and time-dependent multiple myeloma cell death mediated by endoplasmic reticulum induced stress. Unexpectedly, we uncovered two mechanisms of cell death: cellular senescence, as evidenced by increased levels of p16, p21 and γ-H2AX proteins and a caspase 3-independent mechanism consistent with pyroptosis. Cells treated with D089 exhibited high levels of the cleaved form of initiator caspase 8; but failed to show cleavage of executioner caspase 3, a classical apoptotic marker. Cotreatment with the a pan-caspase inhibitor Q-VD-OPh did not affect the cytotoxic effect of D089. In contrast, cleaved caspase 1, an inflammatory caspase downstream of caspases 8/9, was increased by D089 treatment. Cells treated with D089 in addition to either a caspase 1 inhibitor or siRNA-caspase 1 showed increased IC50 values, indicating a contribution of cleaved caspase 1 to cell death. Downstream effects of caspase 1 activation after drug treatment included increases in IL1B, gasdermin D cleavage, and HMGB1 translocation from the nucleus to the cytoplasm. Drug treated cells underwent a ‘ballooning’ morphology characteristic of pyroptosis, rather than ‘blebbing’ typically associated with apoptosis. ASC specks colocalized with NLRP3 in proximity ligation assays after drug treatment, indicating inflammasome activation and further confirming pyroptosis as a contributor to cell death. Thus, the small molecule MYC G4 stabilizer, D089, provides a new tool compound for studying pyroptosis. These studies suggest that inducing both tumor senescence and pyroptosis may have therapeutic potential for cancer treatment.


2019 ◽  
Vol 20 (15) ◽  
pp. 3675 ◽  
Author(s):  
Gáll ◽  
Balla ◽  
Balla

The prevalence of vascular disorders continues to rise worldwide. Parallel with that, new pathophysiological pathways have been discovered, providing possible remedies for prevention and therapy in vascular diseases. Growing evidence suggests that endoplasmic reticulum (ER) stress is involved in a number of vasculopathies, including atherosclerosis, vascular brain events, and diabetes. Heme, which is released from hemoglobin or other heme proteins, triggers various pathophysiological consequence, including heme stress as well as ER stress. The potentially toxic free heme is converted by heme oxygenases (HOs) into carbon monoxide (CO), iron, and biliverdin (BV), the latter of which is reduced to bilirubin (BR). Redox-active iron is oxidized and stored by ferritin, an iron sequestering protein which exhibits ferroxidase activity. In recent years, CO, BV, and BR have been shown to control cellular processes such as inflammation, apoptosis, and antioxidant defense. This review covers our current knowledge about how heme induced endoplasmic reticulum stress (HIERS) participates in the pathogenesis of vascular disorders and highlights recent discoveries in the molecular mechanisms of HO-mediated cytoprotection in heme stress and ER stress, as well as crosstalk between ER stress and HO-1. Furthermore, we focus on the translational potential of HIERS and heme oxygenase-1 (HO-1) in atherosclerosis, diabetes mellitus, and brain hemorrhage.


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