Sulforaphane reduction of testicular apoptotic cell death in diabetic mice is associated with the upregulation of Nrf2 expression and function

2014 ◽  
Vol 307 (1) ◽  
pp. E14-E23 ◽  
Author(s):  
Yonggang Wang ◽  
Zhiguo Zhang ◽  
Weiying Guo ◽  
Weixia Sun ◽  
Xiao Miao ◽  
...  

Diabetes-induced testicular cell death is due predominantly to oxidative stress. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an important transcription factor in controlling the antioxidative system and is inducible by sulforaphane (SFN). To test whether SFN prevents diabetes-induced testicular cell death, an insulin-defective stage of type 2 diabetes (IDS-T2DM) was induced in mice. This was accomplished by feeding them a high-fat diet (HFD) for 3 mo to induce insulin resistance and then giving one intraperitoneal injection of streptozotocin to induce hyperglycemia while age-matched control mice were fed a normal diet (ND). IDS-T2DM and ND-fed control mice were then further subdivided into those with or without 4-mo SFN treatment. IDS-T2DM induced significant increases in testicular cell death presumably through receptor and mitochondrial pathways, shown by increased ratio of Bax/Bcl2 expression and cleavage of caspase-3 and caspase-8 without significant change of endoplasmic reticulum stress. Diabetes also significantly increased testicular oxidative damage and inflammation. All of these diabetic effects were significantly prevented by SFN treatment with upregulated Nrf2 expression. These results suggest that IDS-T2DM induces testicular cell death presumably through caspase-8 activation and mitochondria-mediated cell death pathways and also by significantly downregulating testicular Nrf2 expression and function. SFN upregulates testicular Nrf2 expression and its target antioxidant expression, which was associated with significant protection of the testis from IDS-T2DM-induced germ cell death.

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1827 ◽  
Author(s):  
Khurshid Ahmad ◽  
Vishal M. Balaramnavar ◽  
Navaneet Chaturvedi ◽  
Saif Khan ◽  
Shafiul Haque ◽  
...  

Caspase 8 is a central player in the apoptotic cell death pathway and is also essential for cytokine processing. The critical role of this protease in cell death pathways has generated research interest because its activation has also been linked with neural cell death. Thus, blocking the activity of caspase 8 is considered a potential therapy for neurodegenerative diseases. To extend the repertoire of caspase 8 inhibitors, we employed several computational approaches to identify potential caspase 8 inhibitors. Based on the structural information of reported inhibitors, we designed several individual and consensus pharmacophore models and then screened the ZINC database, which contains 105,480 compounds. Screening generated 5332 candidates, but after applying stringent criteria only two candidate compounds, ZINC19370490 and ZINC04534268, were evaluated by molecular dynamics simulations and subjected to Molecular Mechanics/Poisson Boltzmann Surface Area (MM-PBSA) analysis. These compounds were stable throughout simulations and interacted with targeted protein by forming hydrogen and van der Waal bonds. MM-PBSA analysis showed that these compounds were comparable or better than reported caspase 8 inhibitors. Furthermore, their physical properties were found to be acceptable, and they are non-toxic according to the ADMET online server. We suggest that the inhibitory efficacies of ZINC19370490 and ZINC04534268 be subjected to experimental validation.


2021 ◽  
Vol 55 (1) ◽  
pp. 235-263
Author(s):  
Daichao Xu ◽  
Chengyu Zou ◽  
Junying Yuan

The receptor-interacting protein kinase 1 (RIPK1) is recognized as a master upstream regulator that controls cell survival and inflammatory signaling as well as multiple cell death pathways, including apoptosis and necroptosis. The activation of RIPK1 kinase is extensively modulated by ubiquitination and phosphorylation, which are mediated by multiple factors that also control the activation of the NF-κB pathway. We discuss current findings regarding the genetic modulation of RIPK1 that controls its activation and interaction with downstream mediators, such as caspase-8 and RIPK3, to promote apoptosis and necroptosis. We also address genetic autoinflammatory human conditions that involve abnormal activation of RIPK1. Leveraging these new genetic and mechanistic insights, we postulate how an improved understanding of RIPK1 biology may support the development of therapeutics that target RIPK1 for the treatment of human inflammatory and neurodegenerative diseases.


2014 ◽  
Vol 8 (3) ◽  
pp. 596-608 ◽  
Author(s):  
Yves Matthess ◽  
Monika Raab ◽  
Rainald Knecht ◽  
Sven Becker ◽  
Klaus Strebhardt

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4585-4585
Author(s):  
Christian Scholz ◽  
Antje Richter ◽  
Anja Richter ◽  
Bernd Dörken ◽  
Peter T. Daniel

Abstract Arsenic trioxide (As2O3, arsenite) efficiently kills cells from various hematologic malignancies and has successfully been employed for the treatment of acute promyelocytic leukaemia, myelodysplastic syndrome, and multiple myeloma. Investigating the mechanisms of arsenic trioxide-induced cell death, we recently demonstrated that arsenite-mediated cell demise has a partially necrotic phenotype, occurs independently of the extrinsic death receptor pathway of apoptosis, and is not hampered by the absence of functioning caspases. On the contrary, cell death proceeded entirely via an intrinsic, mitochondrial pathway and was efficiently blocked by the anti-apoptotic Bcl-2 family members Bcl-2 or Bcl-xL. Here, we address the role of the pro-apoptotic multi-domain Bcl-2 family members Bax and Bak. By employing different cell lines deficient for Bax and/or Bak, we demonstrate that Bax- or Bak-deficiency as well as the combined absence only partially blocks arsenite-induced cell death. While the detection of an additive effect of the combined Bax-/Bak-deficiency argues for a non redundant function of Bax and Bak, the persistence of a substantial percentage of arsenite-mediated cell demise in different double deficient cell lines nevertheless suggests a mode of arsenic trioxide-mediated cell death independent from these central inducers of apoptotic cell demise. The presented data add to the notion that arsenic trioxide kills tumor cells independent of the apoptotic machinery, and warrants further investigation on the efficacy of this compound in malignancies with deficiencies of the apoptotic cell death pathways.


2017 ◽  
Vol 114 (13) ◽  
pp. E2786-E2795 ◽  
Author(s):  
Lisa P. Daley-Bauer ◽  
Linda Roback ◽  
Lynsey N. Crosby ◽  
A. Louise McCormick ◽  
Yanjun Feng ◽  
...  

The complex interplay between caspase-8 and receptor-interacting protein (RIP) kinase RIP 3 (RIPK3) driving extrinsic apoptosis and necroptosis is not fully understood. Murine cytomegalovirus triggers both apoptosis and necroptosis in infected cells; however, encoded inhibitors of caspase-8 activity (M36) and RIP3 signaling (M45) suppress these antiviral responses. Here, we report that this virus activates caspase-8 in macrophages to trigger apoptosis that gives rise to secondary necroptosis. Infection with double-mutant ΔM36/M45mutRHIM virus reveals a signaling pattern in which caspase-8 activates caspase-3 to drive apoptosis with subsequent RIP3-dependent activation of mixed lineage kinase domain-like (MLKL) leading to necroptosis. This combined cell death signaling is highly inflammatory, greater than either apoptosis induced by ΔM36 or necroptosis induced by M45mutRHIM virus. IL-6 production by macrophages is dramatically increased during double-mutant virus infection and correlates with faster antiviral responses in the host. Collaboratively, M36 and M45 target caspase-8 and RIP3 pathways together to suppress this proinflammatory cell death. This study reveals the effect of antiviral programmed cell death pathways on inflammation, shows that caspase-8 activation may go hand-in-hand with necroptosis in macrophages, and revises current understanding of independent and collaborative functions of M36 and M45 in blocking apoptotic and necroptotic cell death responses.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Yonggang Wang ◽  
Hao Wu ◽  
Ying Xin ◽  
Yang Bai ◽  
Lili Kong ◽  
...  

Although angiotensin II (Ang II) was reported to facilitate sperm motility and intratesticular sperm transport, recent findings shed light on the efficacy of Ang II in stimulating inflammatory events in testicular peritubular cells, effect of which may play a role in male infertility. It is still unknown whether Ang II can induce testicular apoptotic cell death, which may be a more direct action of Ang II in male infertility. Therefore, the present study aims to determine whether Ang II can induce testicular apoptotic cell death and whether this action can be prevented by sulforaphane (SFN) via activating nuclear factor (erythroid-derived 2)-like 2 (NRF2), the governor of antioxidant-redox signalling. Eight-week-old male C57BL/6J wild type (WT) and Nrf2 gene knockout mice were treated with Ang II, in the presence or absence of SFN. In WT mice, SFN activated testicular NRF2 expression and function, along with a marked attenuation in Ang II-induced testicular oxidative stress, inflammation, endoplasmic reticulum stress, and apoptotic cell death. Deletion of the Nrf2 gene led to a complete abolishment of these efficacies of SFN. The present study indicated that Ang II may result in testicular apoptotic cell death, which can be prevented by SFN via the activation of NRF2.


2014 ◽  
Vol 15 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Tom Vanden Berghe ◽  
Andreas Linkermann ◽  
Sandrine Jouan-Lanhouet ◽  
Henning Walczak ◽  
Peter Vandenabeele

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1707
Author(s):  
Pratyusha Mandal ◽  
Lynsey N. Nagrani ◽  
Liliana Hernandez ◽  
Anita Louise McCormick ◽  
Christopher P. Dillon ◽  
...  

Programmed cell death pathways eliminate infected cells and regulate infection-associated inflammation during pathogen invasion. Cytomegaloviruses encode several distinct suppressors that block intrinsic apoptosis, extrinsic apoptosis, and necroptosis, pathways that impact pathogenesis of this ubiquitous herpesvirus. Here, we expanded the understanding of three cell autonomous suppression mechanisms on which murine cytomegalovirus relies: (i) M38.5-encoded viral mitochondrial inhibitor of apoptosis (vMIA), a BAX suppressor that functions in concert with M41.1-encoded viral inhibitor of BAK oligomerization (vIBO), (ii) M36-encoded viral inhibitor of caspase-8 activation (vICA), and (iii) M45-encoded viral inhibitor of RIP/RHIM activation (vIRA). Following infection of bone marrow-derived macrophages, the virus initially deflected receptor-interacting protein kinase (RIPK)3-dependent necroptosis, the most potent of the three cell death pathways. This process remained independent of caspase-8, although suppression of this apoptotic protease enhances necroptosis in most cell types. Second, the virus deflected TNF-mediated extrinsic apoptosis, a pathway dependent on autocrine TNF production by macrophages that proceeds independently of mitochondrial death machinery or RIPK3. Third, cytomegalovirus deflected BCL-2 family protein-dependent mitochondrial cell death through combined TNF-dependent and -independent signaling even in the absence of RIPK1, RIPK3, and caspase-8. Furthermore, each of these cell death pathways dictated a distinct pattern of cytokine and chemokine activation. Therefore, cytomegalovirus employs sequential, non-redundant suppression strategies to specifically modulate the timing and execution of necroptosis, extrinsic apoptosis, and intrinsic apoptosis within infected cells to orchestrate virus control and infection-dependent inflammation. Virus-encoded death suppressors together hold control over an intricate network that upends host defense and supports pathogenesis in the intact mammalian host.


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