scholarly journals Tau and Caspase 3 as Targets for Neuroprotection

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Anat Idan-Feldman ◽  
Regina Ostritsky ◽  
Illana Gozes

The peptide drug candidate NAP (davunetide) has demonstrated protective effects in variousin vivoandin vitromodels of neurodegeneration. NAP was shown to reduce tau hyperphosphorylation as well as to prevent caspase-3 activation and cytochrome-3 release from mitochondria, both characteristic of apoptotic cell death. Recent studies suggest that caspases may play a role in tau pathology. The purpose of this study was to evaluate the effect of NAP on tau hyperphosphorylation and caspase activity in the same biological system. Our experimental setup used primary neuronal cultures subjected to oxygen-glucose deprivation (OGD), with and without NAP or caspase inhibitor. Cell viability was assessed by measuring mitochondrial activity (MTS assay), and immunoblots were used for analyzing protein level. It was shown that apoptosis was responsible for all cell death occurring following ischemia, and NAP treatment showed a concentration-dependent protection from cell death. Ischemia caused an increase in the levels of active caspase-3 and hyperphosphorylated tau, both of which were prevented by either NAP or caspase-inhibitor treatment. Our data suggest that, in this model system, caspase activation may be an upstream event to tau hyperphosphorylation, although additional studies will be required to fully elucidate the cascade of events.

2019 ◽  
Vol 169 (2) ◽  
pp. 333-352 ◽  
Author(s):  
Chunjuan Song ◽  
Adhithiya Charli ◽  
Jie Luo ◽  
Zainab Riaz ◽  
Huajun Jin ◽  
...  

Abstract Chronic exposure to pesticides is implicated in the etiopathogenesis of Parkinson’s disease (PD). Previously, we showed that dieldrin induces dopaminergic neurotoxicity by activating a cascade of apoptotic signaling pathways in experimental models of PD. Here, we systematically investigated endosulfan’s effect on the interplay between apoptosis and autophagy in dopaminergic neuronal cell models of PD. Exposing N27 dopaminergic neuronal cells to endosulfan rapidly induced autophagy, indicated by an increased number of autophagosomes and LC3-II accumulation. Prolonged endosulfan exposure (>9 h) triggered apoptotic signaling, including caspase-2 and -3 activation and protein kinase C delta (PKCδ) proteolytic activation, ultimately leading to cell death, thus demonstrating that autophagy precedes apoptosis during endosulfan neurotoxicity. Furthermore, inhibiting autophagy with wortmannin, a phosphoinositide 3-kinase inhibitor, potentiated endosulfan-induced apoptosis, suggesting that autophagy is an early protective response against endosulfan. Additionally, Beclin-1, a major regulator of autophagy, was cleaved during the initiation of apoptotic cell death, and the cleavage was predominantly mediated by caspase-2. Also, caspase-2 and caspase-3 inhibitors effectively blocked endosulfan-induced apoptotic cell death. CRISPR/Cas9-based stable knockdown of PKCδ significantly attenuated endosulfan-induced caspase-3 activation, indicating that the kinase serves as a regulatory switch for apoptosis. Additional studies in primary mesencephalic neuronal cultures confirmed endosulfan’s effect on autophagy and neuronal degeneration. Collectively, our results demonstrate that a functional interplay between autophagy and apoptosis dictate pesticide-induced neurodegenerative processes in dopaminergic neuronal cells. Our study provides insight into cell death mechanisms in environmentally linked neurodegenerative diseases.


2021 ◽  
Vol 22 (4) ◽  
pp. 2006
Author(s):  
Mi Jin Kim ◽  
Jinhong Park ◽  
Jinho Kim ◽  
Ji-Young Kim ◽  
Mi-Jin An ◽  
...  

Mercury is one of the detrimental toxicants that can be found in the environment and exists naturally in different forms; inorganic and organic. Human exposure to inorganic mercury, such as mercury chloride, occurs through air pollution, absorption of food or water, and personal care products. This study aimed to investigate the effect of HgCl2 on cell viability, cell cycle, apoptotic pathway, and alters of the transcriptome profiles in human non-small cell lung cancer cells, H1299. Our data show that HgCl2 treatment causes inhibition of cell growth via cell cycle arrest at G0/G1- and S-phase. In addition, HgCl2 induces apoptotic cell death through the caspase-3-independent pathway. Comprehensive transcriptome analysis using RNA-seq indicated that cellular nitrogen compound metabolic process, cellular metabolism, and translation for biological processes-related gene sets were significantly up- and downregulated by HgCl2 treatment. Interestingly, comparative gene expression patterns by RNA-seq indicated that mitochondrial ribosomal proteins were markedly altered by low-dose of HgCl2 treatment. Altogether, these data show that HgCl2 induces apoptotic cell death through the dysfunction of mitochondria.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1204
Author(s):  
Heike Wanka ◽  
Philipp Lutze ◽  
Alexander Albers ◽  
Janine Golchert ◽  
Doreen Staar ◽  
...  

A stimulated renin-angiotensin system is known to promote oxidative stress, apoptosis, necrosis and fibrosis. Renin transcripts (renin-b; renin-c) encoding a cytosolic renin isoform have been discovered that may in contrast to the commonly known secretory renin (renin-a) exert protective effects Here, we analyzed the effect of renin-a and renin-b overexpression in H9c2 cardiomyoblasts on apoptosis and necrosis as well as on potential mechanisms involved in cell death processes. To mimic ischemic conditions, cells were exposed to glucose starvation, anoxia or combined oxygen–glucose deprivation (OGD) for 24 h. Under OGD, control cells exhibited markedly increased necrotic and apoptotic cell death accompanied by enhanced ROS accumulation, loss of mitochondrial membrane potential and decreased ATP levels. The effects of OGD on necrosis were exaggerated in renin-a cells, but markedly diminished in renin-b cells. However, with respect to apoptosis, the effects of OGD were almost completely abolished in renin-b cells but interestingly also moderately diminished in renin-a cells. Under glucose depletion we found opposing responses between renin-a and renin-b cells; while the rate of necrosis and apoptosis was aggravated in renin-a cells, it was attenuated in renin-b cells. Based on our results, strategies targeting the regulation of cytosolic renin-b as well as the identification of pathways involved in the protective effects of renin-b may be helpful to improve the treatment of ischemia-relevant diseases.


2001 ◽  
Vol 79 (11) ◽  
pp. 953-958 ◽  
Author(s):  
Ellyawati Candra ◽  
Kimihiro Matsunaga ◽  
Hironori Fujiwara ◽  
Yoshihiro Mimaki ◽  
Yutaka Sashida ◽  
...  

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (β-D-glucopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 µM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 µM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.Key words: steroidal saponin, tigogenin hexasaccharide, apoptosis, DNA fragmentation, murine leukemic L1210 cells.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sweena Parmar ◽  
Xiaokun Geng ◽  
Changya Peng ◽  
Murali Guthikonda ◽  
Yuchuan Ding

Objectives: Normobaric oxygenation (NBO) has been shown to provide neuroprotection in vivo and in vitro . Yet, a recent Phase 2 clinical trial investigating NBO therapy in acute ischemic stroke was terminated due to questionable therapeutic benefit. NBO therapy alone may be insufficient to produce improved outcomes. In our recent study, we demonstrated a strong neuroprotective effect of ethanol at a dose of 1.5 g/kg (equivalent to the human legal driving limit). In this study, we sought to identify whether low-dose ethanol administration enhances the neuroprotection offered by NBO and whether combined administration of NBO with ethanol is associated with reduced apoptosis. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion (MCAO) for 2 h, followed by reperfusion. Ischemic animals received either an intraperitoneal injection of 1.0 g/kg ethanol, 2 h of 100% NBO, or both ethanol and NBO. The Cell Death Detection ELISA Assay (Roche) was performed to determine apoptotic cell death at 24 h after reperfusion. Levels of pro-apoptotic (Caspase-3, Bcl-2-associated X-BAX, and Apoptosis-Inducing Factor-AIF) and anti-apoptotic proteins (Bcl-2 and Bcl-xL) were determined by Western blot analysis at 3 and 24 h after reperfusion. Results: As expected, untreated ischemic rats had the highest apoptotic cell death. Combined NBO/ethanol therapy decreased cell death by 48%, as compared to 29% with ethanol and 22% with NBO. Similarly, combined NBO/ethanol therapy promoted the greatest expression of anti-apoptotic factors and the lowest expression of pro-apoptotic proteins at 3 h after reperfusion. This effect was maintained at 24 h and even more pronounced for AIF and Caspase-3. Conclusions: Given singularly, NBO and ethanol improved the degree of cell death, decreased the expression of pro-apoptotic proteins, and increased the expression of anti-apoptotic proteins. Yet, when administered together, their effects largely compounded. These results suggest a synergistic neuroprotection offered by NBO with ethanol, which may be attributed at least in part to their shared role in modulating neuronal apoptosis.


2004 ◽  
Vol 32 (03) ◽  
pp. 377-387 ◽  
Author(s):  
Hyung-Jin Kim ◽  
Seon Il Jang ◽  
Young-Jun Kim ◽  
Hyun-Ock Pae ◽  
Hae-Young Won ◽  
...  

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.


2004 ◽  
Vol 17 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Anna Csiszar ◽  
Zoltan Ungvari ◽  
Akos Koller ◽  
John G. Edwards ◽  
Gabor Kaley

Previously we demonstrated that aging in coronary arteries is associated with proinflammatory phenotypic changes and decreased NO bioavailability, which, we hypothesized, promotes vascular disease by enhancing endothelial apoptosis. To test this hypothesis we characterized proapoptotic alterations in the phenotype of coronary arteries of aged (26 mo old) and young (3 mo old) F344 rats. DNA fragmentation analysis and TUNEL assay showed that in aged vessels there was an approximately fivefold increase in the number of apoptotic endothelial cells. In aged coronary arteries there was an increased expression of TNFα, TNFβ, and caspase 9 (microarray, real-time PCR), as well as increased caspase 9 and caspase 3 activity, whereas expression of TNFR1, TNFα-converting enzyme (TACE), Bcl-2, Bcl-X(L), Bid, Bax, caspase 8, and caspase 3 were unchanged. In vessel culture (18 h) incubation of aged coronary arteries with a TNF blocking antibody or the NO donor S-nitroso-penicillamine (SNAP) decreased apoptotic cell death. Incubation of young arteries with exogenous TNFα increased caspase 9 activity and elicited endothelial apoptosis, which was attenuated by SNAP. Inhibition of NO synthesis in cultured young coronary arteries also induced apoptotic cell death and potentiated the apoptotic effect of TNFα. Thus we propose that age-related upregulation of TNFα and caspase 9 and decreased bioavailability of NO promote endothelial apoptosis in coronary arteries that may lead to impaired endothelial function and ischemic heart disease in the elderly.


2009 ◽  
Vol 37 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Mathieu Vinken ◽  
Elke Decrock ◽  
Elke De Vuyst ◽  
Luc Leybaert ◽  
Tamara Vanhaecke ◽  
...  

This study was set up to critically evaluate a commonly-used in vitro model of hepatocellular apoptotic cell death, in which freshly isolated hepatocytes, cultured in a monolayer configuration, are exposed to a combination of Fas ligand and cycloheximide for six hours. A set of well-acknowledged cell death markers was addressed: a) cell morphology was studied by light microscopy; b) apoptotic and necrotic cell populations were quantified by in situ staining with Annexin-V, Hoechst 33342 and propidium iodide (PI); c) apoptotic and necrotic activities were monitored by probing caspase 3-like activity and measuring the extracellular leakage of lactate dehydrogenase (LDH), respectively; and d) the expression of apoptosis regulators was investigated by immunoblotting. The initiation of apoptosis was evidenced by the activation of caspase 8 and caspase 9, and increased Annexin-V reactivity. Progression through the apoptotic process was confirmed by the activation of caspase 3 and Bid, the enhanced expression of Bax, and the occurrence of nuclear fragmentation. Late transition to a necrotic appearance was demonstrated by an increased number of PI-positive cells and augmented extracellular release of LDH. Thus, the in vitro model allows the study of the entire course of Fas-mediated hepatocellular apoptotic cell death, which is not possible in vivo. This experimental system can serve a broad range of in vitro pharmaco-toxicological purposes, thereby directly assisting in the reduction of animal experimentation.


Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 207 ◽  
Author(s):  
Yi-Yue Wang ◽  
Jun Hyeok Kwak ◽  
Kyung-Tae Lee ◽  
Tsegaye Deyou ◽  
Young Pyo Jang ◽  
...  

The seeds of Millettia ferruginea are used in fishing, pesticides, and folk medicine in Ethiopia. Here, the anti-cancer effects of isoflavones isolated from M. ferruginea were evaluated in human ovarian cancer cells. We found that isoflavone ferrugone and 6,7-dimethoxy-3’,4’-methylenedioxy-8-(3,3-dimethylallyl)isoflavone (DMI) had potent cytotoxic effects on human ovarian cancer cell A2780 and SKOV3. Ferrugone and DMI treatment increased the sub-G1 cell population in a dose-dependent manner in A2780 cells. The cytotoxic activity of ferrugone and DMI was associated with the induction of apoptosis, as shown by an increase in annexin V-positive cells. Z-VAD-fmk, a broad-spectrum caspase inhibitor, and z-DEVD-fmk, a caspase-3 inhibitor, significantly reversed both the ferrugone and DMI-induced apoptosis, suggesting that cell death stimulated by the isoflavones is mediated by caspase-3-dependent apoptosis. Additionally, ferrugone-induced apoptosis was found to be caspase-8-dependent, while DMI-induced apoptosis was caspase-9-dependent. Notably, DMI, but not ferrugone, increased the intracellular levels of reactive oxygen species (ROS), and antioxidant N-acetyl-L-cysteine (NAC) attenuated the pro-apoptotic activity of DMI. These data suggest that DMI induced apoptotic cell death through the intrinsic pathway via ROS production, while ferrugone stimulated the extrinsic pathway in human ovarian cancer cells.


2008 ◽  
Vol 5 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Sang Chan Kim ◽  
Sook Jahr Park ◽  
Jong Rok Lee ◽  
Jung Cheol Seo ◽  
Chae Ha Yang ◽  
...  

Licorice,Glycyrrhizae radix, is one of the herbal medicines in East Asia that has been commonly used for treating various diseases, including stomach disorders. This study investigated the effect of licorice on arsenite (As)-induced cytotoxicity in H4IIE cells, a rat hepatocyte-derived cell line. Cell viability was significantly diminished in As-treated H4IIE cells in a time and concentration-dependent manner. Furthermore, results from flow cytometric assay and DNA laddering in H4IIE cells showed that As treatment induced apoptotic cell death by activating caspase-3. Licorice (0.1 and 1.0 mg ml−1) treatment significantly inhibited cell death and the activity of caspase-3 in response to As exposure. These results demonstrate that licorice induced a cytoprotective effect against As-induced cell death by inhibition of caspase-3.


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