scholarly journals Prep1 Directly Regulates the Intrinsic Apoptotic Pathway by Controlling Bcl-XL Levels

2008 ◽  
Vol 29 (5) ◽  
pp. 1143-1151 ◽  
Author(s):  
Nicola Micali ◽  
Carmelo Ferrai ◽  
Luis C. Fernandez-Diaz ◽  
Francesco Blasi ◽  
Massimo P. Crippa

ABSTRACT The Prep1 homeodomain transcription factor is essential in embryonic development. Prep1 hypomorphic mutant mouse (Prep1 i/i ) embryos (embryonic day 9.5) display an increased terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling reaction compared to wild-type (WT) littermates. Prep1 i/i mouse embryo fibroblasts (MEFs) show an increased basal level of annexin V binding activity, reduction of the mitochondrial-membrane potential, and increased caspase 9 and 3 activation, indicating increased apoptosis. Prep1 i/i MEFs also respond faster than WT MEFs to genotoxic stress, indicating increased activation of the intrinsic apoptotic pathways. We did not observe an increase in p53 or an abnormal p53 response to apoptotic stimuli. However, hypomorphic MEFs have decreased endogenous levels of antiapoptotic Bcl-XL mRNA and protein, and Bcl-x overexpression rescues the defect of Prep1 i/i MEFs. Using transient transfections and chromatin immunoprecipitation, we identified the Bcl-x promoter as a novel target of Prep1. Thus, Prep1 directly controls mitochondrial homeostasis (and the apoptotic potential) by modulating Bcl-x gene expression.

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Dongxu Zhang ◽  
Houxian Liu ◽  
Binbin Yang ◽  
Jiasheng Hu ◽  
Yue Cheng

Abstract The present study aims to evaluate the anticancer effect of L-securinine on androgen-independent prostate cancer (AIPC) DU145 cells. L-securinine (2.5, 5, and 10 μM) treatment for 24, 48 and 72 h displayed strong growth inhibitory effect on DU145 cells in a concentration and time-dependent fashion but has less toxicity toward normal androgen-dependent LNCaP cells. Hoechst 332582 staining of DU145 cells and Annexin V-FITC/ PI dual-labeling followed by flow cytometry assay identified that this growth inhibition by L-securinine would be due to the induction of apoptosis. Moreover Transwell assay revealed that L-securinine significantly inhibited the cell migration/invasion ability of DU145 cells. Furthermore, results of western blotting showed that the involvement of mitochondrial apoptotic pathway in the L-securinine-induced apoptosis of DU145 cell, as evidenced by an increase in the protein expression of Bax, cleaved caspase-9, cleaved caspase-3, cytosolic cytochrome c, and cleaved PARP, together with a unchanged cleaved caspase-8 and decreased Bcl-2 protein expression. Also, L-securinine-induced antimetastatic activity in DU145 cells was associated with decreased protein expression of MMP-2 and MMP-9 and concurrent reduction of VEGF. In addition, further studies revealed that L-securinine may inhibit the protein expression of AGTR1, p-MEK1/2, p-ERK1/2, p-STAT3, PAX2, and p-PAX2, while the expression of ERK1/2, MEK1/2, and STAT3 protein retains intact. These findings suggest that L-securinine may be a promising chemopreventive agent against AIPC.


2018 ◽  
Vol 8 (3) ◽  
pp. 208-216 ◽  
Author(s):  
Andrea Breglia ◽  
Grazia Maria Virzì ◽  
Silvia Pastori ◽  
Alessandra Brocca ◽  
Massimo de Cal ◽  
...  

Background: Cardiorenal syndrome type 1 (CRS type 1) is characterized by a rapid worsening of cardiac function leading to acute kidney injury (AKI). Its pathophysiology is complex and not completely understood. In this study, we examined the role of apoptosis and the caspase pathways involved. Material and Methods: We enrolled 40 acute heart failure (AHF) patients, 11 of whom developed AKI characterizing CRS type 1. We exposed the human cell line U937 to plasma from the CRS type 1 and AHF groups and then we evaluated apoptotic activity by annexin-V evaluation, determination of caspase-3, -8 and -9 levels, and BAX, BAD, and FAS gene expression. Results: We observed significant upregulation of apoptosis in monocytes exposed to CRS type 1 plasma compared to AHF, with increased levels of caspase-3 (p < 0.01), caspase-9 (p < 0.01), and caspase-8 (p < 0.03) showing activation of both intrinsic and extrinsic pathways. Furthermore, monocytes exposed to CRS type 1 plasma had increased gene expression of BAX and BAD (intrinsic pathways) (p = 0.010 for both). Furthermore, strong significant correlations between the caspase-9 levels and BAD and BAX gene expression were observed (Spearman ρ = – 0.76, p = 0.011, and ρ = – 0.72, p = 0.011). Conclusion: CRS type 1 induces dual apoptotic pathway activation in monocytes; the two pathways converged on caspase-3. Many factors may induce activation of both intrinsic and extrinsic apoptotic pathways in CRS type 1 patients, such as upregulation of proinflammatory cytokines and hypoxia/ischemia. Further investigations are necessary to corroborate the present findings, and to better understand the pathophysiological mechanism and consequent therapeutic and prognostic implications for CRS type 1.


Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1872-1877 ◽  
Author(s):  
Vanessa S. Marsden ◽  
Thomas Kaufmann ◽  
Lorraine A. O'Reilly ◽  
Jerry M. Adams ◽  
Andreas Strasser

Cytokines promote survival of mast cells by inhibiting apoptotic pathways regulated by the Bcl-2 protein family. We previously showed that lymphocyte apoptosis can proceed via a Bcl-2-inhibitable pathway independent of the canonical initiator caspase, caspase-9, and its adaptor, Apaf-1. Here we report that mast cells lacking caspase-9 or Apaf-1 are refractory to apoptosis after cytotoxic insults but still lose effector function and ability to proliferate. In response to cytokine deprivation or DNA damage, fetal liver-derived mast cells lacking Apaf-1 or caspase-9 failed to undergo apoptosis. Nevertheless, the cytokine-starved cells were not functionally alive, because, unlike those overexpressing Bcl-2, they could not degranulate on Fcϵ receptor stimulation or resume proliferation on re-addition of cytokine. Furthermore, mast cells lacking Apaf-1 or caspase-9 had no survival advantage over wild-type counterparts in vivo. These results indicate that the Apaf-1/caspase-9-independent apoptotic pathway observed in lymphocytes is ineffective in cytokine-deprived mast cells. However, although Apaf-1 and caspase-9 are essential for mast cell apoptosis, neither is required for the functional or clonogenic death of the cells, which may be due to mitochondrial dysfunction.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3290-3290 ◽  
Author(s):  
Mitchell Reed Smith ◽  
Fang Jin ◽  
Indira Joshi

Abstract Monoclonal antibodies and chemotherapy can be effective, but not curative, therapy for non-Hodgkin s lymphoma (NHL). Rituximab acts by several mechanisms, including directly signaling apoptosis of CD20+ cells via the mitochondrial pathway involving caspase 9. Chemotherapy also activates this apoptotic pathway. TRAIL-R1 and -R2 signaling induces apoptosis via a pathway that activates caspase 8. Thus, we investigated the effects of agonistic monoclonal antibodies to TRAIL-R1 and -R2 on NHL cell lines (DoHH2, WSU-FSCCL and FC-TxFL2, each t(14;18)+, EBV-). TRAIL-R1 (HGS-ETR1) and -R2 (HGS-ETR2) antibodies were from Human Genome Sciences (Rockville, MD). FC-TxFL2 expressed the highest cell surface levels of TRAIL-R1 (DR4, target of HGS-ETR1) and TRAIL-R2 (DR5, target of HGS-ETR2). WSU-FSCCL expressed lower, but significant, levels of each. DoHH2 expressed dim TRAIL-R1 and the lowest levels of TRAIL-R2 of the 3 cell lines. IC50 (MTT assay after 72 hr incubation with antibody) was 0.25mcg/ml for WSU-FSCCL and FC-TxFL2 with either HGS-ETR1 or HGS-ETR2, while DoHH2 was minimally inhibited by either antibody. Both HGS-ETR1 and HGS-ETR2 antibodies induced dose dependent increases in apoptosis (annexin V assay) of WSU-FSCCL and FC-TxFL-2, but not DoHH2. Caspase activation (flow cytometry using fluorescent substrates; Western analysis) was seen 4–6 hr after antibody addition. As expected, caspases 3 and 8 were activated by both antibodies in the two sensitive cell lines. Caspase 9, however, was also activated. Thus, TRAIL-R1 and TRAIL-R2 antibody binding inhibits growth, induces apoptosis and activates caspases 3, 8 and 9 in NHL cells expressing the targets. The induction of caspase 9 suggests cross-talk between the extrinsic and intrinsic pathways, in which activation of caspase 8 leads to cleavage and translocation of bid, which in turn leads to activation of caspase 9, and ultimately caspase 3. We have confirmed that bid cleavage does occur in these NHL cells after HGS-ETR1 and HGS-ETR2 binding. We have further shown that both the pan-caspase inhibitor ZVAD and a specific caspase 8 inhibitor block HGS-ETR1 and HGS-ETR2 induced apoptosis. As predicted, a specific inhibitor of caspase 9 only partially blocks apoptosis. This suggests that combination of the agonist HGS-ETR1 and HGS-ETR2 antibodies with agents that act via the caspase 9 pathway would be rational combinations to test for therapeutic potential in NHL.


2019 ◽  
Vol 126 (6) ◽  
pp. 1661-1672 ◽  
Author(s):  
Yi-Yuan Lin ◽  
Yi Hong ◽  
Shao-Hong Yu ◽  
Xu-Bo Wu ◽  
Woei-Cherng Shyu ◽  
...  

This study was to investigate the effects of exercise training on antiapoptotic pathways and mitochondrial biogenesis in ovariectomized hypertensive rats. Histopathological analysis, TUNEL assay, and Western blotting were performed on the excised hearts from female spontaneously hypertensive rats (SHR), which were divided into a sham-operated sedentary hypertensive (SHR-S), a sedentary hypertensive ovariectomized (SHR-O), and hypertensive ovariectomized rats that underwent treadmill exercise training (SHR-OT; 60 min/day, 5 days/wk) for 8 wk, along with normotensive Wistar Kyoto rats (WKY). When compared with the WKY group, the SHR-S group exhibited decreased protein levels of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and mitochondrial OPA-1 (mitochondrial biogenesis) and decreased further in the SHR-O group. The protein levels of p-PI3K, p-Akt, Bcl-2, Bcl-xL (prosurvival pathways), and the protein levels of PGC-1α and mitochondrial OPA1 (mitochondrial biogenesis) were increased in the SHR-OT group, but estrogen receptor (ER)α and ERβ were not changed when compared with the SHR-O group. The protein levels of t-Bid, Bad, Bax, cytosolic cytochrome c, activated caspase 9, and activated caspase 3 (mitochondria-dependent apoptotic pathways), as well as Fas ligand, TNF-α, Fas receptors, Fas-associated death domain, activated caspase 8 (Fas receptor-dependent apoptotic pathways) were decreased in the SHR-OT group, when compared with the SHR-O group. Exercise training protection on the coexistence of hypertension and ovariectomy-induced cardiac mitochondria-dependent and Fas receptor-dependent apoptotic pathways by enhancing the Bcl2-related and mitochondrial biogenetic prosurvival pathways might provide a new therapeutic effect on cardiac protection in oophorectomized early postmenopausal hypertensive women. NEW & NOTEWORTHY Widely dispersed cardiac apoptosis was found in the coexistence of hypertension and ovariectomy. Exercise training on a treadmill could prevent ovariectomized hypertension-induced widely dispersed cardiac apoptosis via mitochondria-dependent apoptotic pathway (t-Bid, Bad, Bax, cytosolic cytochrome c, activated caspase 9, and activated caspase 3) and Fas receptor-dependent apoptotic pathway (Fas ligand, tumor necrosis factor-α, Fas receptors, Fas-associated death domain, activated caspase 8, and activated caspase 3) through enhancing the Bcl2-related (p-PI3K, p-Akt, Bcl-2, Bcl-xL) and mitochondrial biogenetic (PGC-1α and mitochondrial optic atrophy 1) prosurvival pathways.


Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1375
Author(s):  
Fatin Jannus ◽  
Marta Medina-O’Donnell ◽  
Francisco Rivas ◽  
Luis Díaz-Ruiz ◽  
Eva E. Rufino-Palomares ◽  
...  

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Our recent studies have shown that the diamine-(PEG)ylated oleanolic acid (OADP) has strong anti-tumor effects in HCCs. In this study, we evaluated the anti-tumor mechanisms of OADP in the HepG2 HCC cell line. The cytotoxicity results showed that HepG2 cell viability was markedly reduced, with a very low 50% of cell growth inhibitory concentration (IC50, 0.14 µg/mL). We then investigated the anti-tumor mechanisms of OADP in HepG2 cells. The flow-cytometry analysis was used to evaluate cell apoptosis, indicating that 74–95% of cells were apoptotic. OADP caused cell cycle arrest in the G0/G1 phase and the loss of the mitochondrial membrane potential (MMP). Western blot analysis was performed to assess the expression levels of key proteins associated with the underlying molecular mechanism. The results showed the clear upregulation of caspase-8, caspase-9, caspase-3, Bak, p21, and p53, accompanied by the downregulation of Bcl-2. Similar results were obtained by the cotreatment with OADP and the c-Jun N-terminal kinase (JNK) inhibitor SP600125. Agents such as OADP, which are capable of activating extrinsic and intrinsic apoptotic pathways, may represent potential HCC cancer therapies.


2021 ◽  
Author(s):  
Gabriel Krasovec ◽  
Eric Qeinnec ◽  
Jean-Philippe Chambon

Apoptosis is characterised by an analogous set of morphological features1 that depend on a proteolytic multigenic family, the caspases. Each apoptotic signalling pathway involves a specific initiator caspase, upstream of the pathway regulation, which finally converges to common executioner caspases. Intrinsic apoptosis, previously known as the mitochondrial apoptotic pathway, is often considered as ancestral and evolutionary conserved among animals. First identified in the nematode Caenorhabditis elegans, intrinsic apoptosis was next characterised in fruit fly Drosophila melanogaster and mammals. Intrinsic apoptosis depends on the key initiator caspase-9 (named Ced-3 and Dronc in Caenorhabditis and Drosophila, respectively), the activator Apaf-1 and the Bcl-2 multigenic family. Many functional studies have led to a deep characterisation of intrinsic apoptosis based on those classical models. Nevertheless, the biochemical role of mitochondria, the pivotal function of cytochrome c and the modality of caspases activation remain highly heterogeneous and hide profound molecular divergences among apoptotic pathways in animals. Independent of functional approaches, the phylogenetic history of the signal transduction actors, mostly the caspase family, is the Rosetta Stone to shed light on intrinsic apoptosis evolution. Here, after exhaustive research on CARD-caspases, we demonstrate by phylogenetic analysis that the caspase-9, the fundamental key of intrinsic apoptosis, is deuterostomes-specific, while it is the caspase-2 which is ancestral and common to bilaterians. Our analysis of Bcl-2 family and Apaf-1 confirm the high heterogeneity in apoptotic pathways elaboration in animals. Taken together, our results support convergent emergence of distinct intrinsic apoptotic pathways during metazoan evolution.


2021 ◽  
Vol 22 (7) ◽  
pp. 3345
Author(s):  
Aleksandra Maria Juszczak ◽  
Robert Czarnomysy ◽  
Jakub Władysław Strawa ◽  
Marijana Zovko Končić ◽  
Krzysztof Bielawski ◽  
...  

Jasione montana L. (Campanulaceae) is used in traditional Belarusian herbal medicine for sleep disorders in children, but the chemical composition and biological activity have not been investigated. In this study, the activities of J. montana extracts, their fractions and main compounds were evaluated in amelanotic melanoma C32 (CRL-1585) cells and normal fibroblasts (PCS-201-012). The extracts and fractions were analyzed using liquid chromatography–photodiode array detection–electrospray ionization–mass spectrometry (LC–PDA–ESI–MS/TOF) to characterize 25 compounds. Further, three major and known constituents, luteolin (22) and its derivatives such as 7-O-glucoside (12) and 7-O-sambubioside (9) were isolated and identified. The cytotoxic activities against fibroblasts and the amelanotic melanoma cell line were determined using the fixable viability stain (FVS) assay. The influence of diethyl ether (Et2O) fraction (JM4) and 22 on apoptosis induction was investigated using an annexin V binding assay. The obtained results showed significant cytotoxicity of JM4 and 22 with IC50 values of 119.7 ± 3.2 and 95.1 ± 7.2 μg/mL, respectively. The proapoptotic potential after 22 treatment in the C32 human amelanotic melanoma cell line was comparable to that of vinblastine sulfate (VLB), detecting 29.2 ± 3.0% apoptotic cells. Moreover, 22 displayed less necrotic potential against melanoma cells than VLB. In addition, the influences of JM4 and 22 on the dysfunction of the mitochondrial membrane potential (MMP), cell cycle and activity of caspases 3, 8, 9, and 10 were established. The effects of JM4 on MMP change (74.5 ± 3.0% of the cells showed a reduced MMP) corresponded to the results obtained from the annexin V binding assay and activation of caspase-9. JM4 and 22 displayed a significant impact on caspase-9 (40.9 ± 2.4% of the cells contained active caspase-9 after JM4 treatment and 16.6 ± 0.8% after incubation with 22) and the intrinsic (mitochondrial) apoptotic pathway. Moreover, studies have shown that JM4 and 22 affect the activation of external apoptosis pathways by inducing the caspase-8 and caspase-10 cascades. Thus, activation of caspase-3 and DNA damage via external and internal apoptotic pathways were observed after treatment with JM4 and 22. The obtained results suggest that J. montana extracts could be developed as new topical preparations with potential anticancer properties due to their promising cytotoxic and proapoptotic potential.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2974
Author(s):  
Haneen T. Salah ◽  
Courtney D. DiNardo ◽  
Marina Konopleva ◽  
Joseph D. Khoury

Intrinsic apoptotic pathway dysregulation plays an essential role in all cancers, particularly hematologic malignancies. This role has led to the development of multiple therapeutic agents targeting this pathway. Venetoclax is a selective BCL-2 inhibitor that has been approved for the treatment of chronic lymphoid leukemia and acute myeloid leukemia. Given the reported resistance to venetoclax, understanding the mechanisms of resistance and the potential biomarkers of response is crucial to ensure optimal drug usage and improved patient outcomes. Mechanisms of resistance to venetoclax include alterations involving the BH3-binding groove, BCL2 gene mutations affecting venetoclax binding, and activation of alternative anti-apoptotic pathways. Moreover, various potential genetic biomarkers of venetoclax resistance have been proposed, including chromosome 17p deletion, trisomy 12, and TP53 loss or mutation. This manuscript provides an overview of biomarkers that could predict treatment response to venetoclax.


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