scholarly journals STING promotes senescence, apoptosis, and extracellular matrix degradation in osteoarthritis via the NF-κB signaling pathway

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiang Guo ◽  
Ximiao Chen ◽  
Jiaoxiang Chen ◽  
Gang Zheng ◽  
Chenglong Xie ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Dna Damage ◽  
Interleukin 1 ◽  
Signaling Cascade ◽  
Mechanistic Study ◽  
Novel Approach ◽  
Induced Apoptosis ◽  
Human And Mouse

AbstractDamaged deoxyribonucleic acid (DNA) is a primary pathologic factor for osteoarthritis (OA); however, the mechanism by which DNA damage drives OA is unclear. Previous research demonstrated that the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) participates in DNA damage response. As a result, the current study aimed at exploring the role STING, which is the major effector in the cGAS-STING signaling casacde, in OA progress in vitro, as well as in vivo. In this study, the expression of STING was evaluated in the human and mouse OA tissues, and in chondrocytes exposed to interleukin-1 beta (IL-1β). The influences of STING on the metabolism of the extracellular matrix (ECM), apoptosis, and senescence, were assessed in STING overexpressing and knocking-down chondrocytes. Moreover, the NF-κB-signaling casacde and its role in the regulatory effects of STING on ECM metabolism, apoptosis, and senescence were explored. The STING knockdown lentivirus was intra-articularly injected to evaluate its therapeutic impact on OA in mice in vivo. The results showed that the expression of STING was remarkably elevated in the human and mouse OA tissues and in chondrocytes exposed to IL-1β. Overexpression of STING promoted the expression of MMP13, as well as ADAMTS5, but suppressed the expression of Aggrecan, as well as Collagen II; it also enhanced apoptosis and senescence in chondrocytes exposed to and those untreated with IL-1β. The mechanistic study showed that STING activated NF-κB signaling cascade, whereas the blockage of NF-κB signaling attenuated STING-induced apoptosis and senescence, and ameliorated STING-induced ECM metabolism imbalance. In in vivo study, it was demonstrated that STING knockdown alleviated destabilization of the medial meniscus-induced OA development in mice. In conclusion, STING promotes OA by activating the NF-κB signaling cascade, whereas suppression of STING may provide a novel approach for OA therapy.

scholarly journals TP5, a Peptide Inhibitor of Aberrant and Hyperactive CDK5/p25: A Novel Therapeutic Approach against Glioblastoma

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1935
Author(s):  
Emeline Tabouret ◽  
Herui Wang ◽  
Niranjana Amin ◽  
Jinkyu Jung ◽  
Romain Appay ◽  
...  
Keyword(s):  
Dna Damage ◽  
Therapeutic Option ◽  
Selective Inhibition ◽  
G1 Arrest ◽  
Cyclin Dependent Kinase ◽  
Dna Damaging Agents ◽  
Induced Apoptosis ◽  
Cyclin Dependent Kinase 5

We examined the efficacy of selective inhibition of cyclin-dependent kinase 5 (CDK5) in glioblastoma by TP5. We analyzed its impact in vitro on CDK5 expression and activity, cell survival, apoptosis and cell cycle. DNA damage was analyzed using the expression of γH2A.X and phosphorylated ATM. Its tolerance and efficacy were assessed on in vivo xenograft mouse models. We showed that TP5 decreased the activity but not the expression of CDK5 and p35. TP5 alone impaired cell viability and colony formation of glioblastoma cell lines and induced apoptosis. TP5 increased DNA damage by inhibiting the phosphorylation of ATM, leading to G1 arrest. Whereas CDK5 activity is increased by DNA-damaging agents such as temozolomide and irradiation, TP5 was synergistic with either temozolomide or irradiation due to an accumulation of DNA damage. Concomitant use of TP5 and either temozolomide or irradiation reduced the phosphorylation of ATM, increased DNA damage, and inhibited the G2/M arrest induced by temozolomide or irradiation. TP5 alone suppressed the tumor growth of orthotopic glioblastoma mouse model. The treatment was well tolerated. Finally, alone or in association with irradiation or temozolomide, TP5 prolonged mouse survival. TP5 alone or in association with temozolomide and radiotherapy is a promising therapeutic option for glioblastoma.

scholarly journals BH3-only proteins Puma and Bim are rate-limiting for γ-radiation– and glucocorticoid-induced apoptosis of lymphoid cells in vivo

Blood ◽  
2005 ◽  
Vol 106 (13) ◽  
pp. 4131-4138 ◽  
Author(s):  
Miriam Erlacher ◽  
Ewa M. Michalak ◽  
Priscilla N. Kelly ◽  
Verena Labi ◽  
Harald Niederegger ◽  
...  
Keyword(s):  
Dna Damage ◽  
Target Genes ◽  
Cultured Cells ◽  
Lymphoid Cells ◽  
Whole Body ◽  
Γ Radiation ◽  
B Cell Leukemia ◽  
Induced Apoptosis

Numerous p53 target genes have been implicated in DNA damage–induced apoptosis signaling, but proapoptotic Bcl-2 (B-cell leukemia 2) family members of the BH3 (Bcl-2 homolog region [BH] 3)–only subgroup appear to play the critical initiating role. In various types of cultured cells, 3 BH3-only proteins, namely Puma (p53 up-regulated modulator of apoptosis), Noxa, and Bim (Bcl-2 interacting mediator of cell death), have been shown to initiate p53-dependent as well as p53-independent apoptosis in response to DNA damage and treatment with anticancer drugs or glucocorticoids. In particular, the absence of Puma or Bim renders thymocytes and mature lymphocytes refractory to varying degrees to death induced in vitro by growth factor withdrawal, DNA damage, or glucocorticoids. To assess the in vivo relevance of these findings, we subjected mice lacking Puma, Noxa, or Bim to whole-body γ-radiation or the glucocorticoid dexamethasone and compared lymphocyte survival with that in wild-type and BCL2–transgenic mice. Absence of Puma or Bcl-2 overexpression efficiently protected diverse types of lymphocytes from the effects of γ-radiation in vivo, and loss of Bim provided lower but significant protection in most lymphocytes, whereas Noxa deficiency had no impact. Furthermore, both Puma and Bim were found to contribute significantly to glucocorticoid-induced killing. Our results thus establish that Puma and Bim are key initiators of γ-radiation– and glucocorticoid-induced apoptosis in lymphoid cells in vivo.

Interruption of the MEK/ERK signaling cascade promotes dihydroartemisinin-induced apoptosis in vitro and in vivo

APOPTOSIS ◽  
2011 ◽  
Vol 16 (5) ◽  
pp. 511-523 ◽  
Author(s):  
Ning Gao ◽  
Amit Budhraja ◽  
Senping Cheng ◽  
E-Hu Liu ◽  
Cheng Huang ◽  
...  
Keyword(s):  
Erk Signaling ◽  
Signaling Cascade ◽  
Induced Apoptosis

scholarly journals Constitutive GLI1 expression in chondrosarcoma is regulated by major vault protein via mTOR/S6K1 signaling cascade

2021 ◽  
Author(s):  
Wei Wang ◽  
Taiqiang Yan ◽  
Wei Guo ◽  
Jianfang Niu ◽  
Zhiqing Zhao ◽  
...  
Keyword(s):  
Hedgehog Signaling ◽  
Affinity Purification ◽  
Hedgehog Pathway ◽  
Signaling Cascade ◽  
Major Vault Protein ◽  
Purification Method ◽  
Gli1 Expression ◽  
Induced Apoptosis

AbstractHedgehog signaling plays a pivotal role in embryonic pattern formation and diverse aspects of the postnatal biological process. Perturbation of the hedgehog pathway and overexpression of GLI1, a downstream transcription factor in the hedgehog pathway, are highly relevant to several malignancies including chondrosarcoma (CS). We previously found that knocking down expression of GLI1 attenuates the disrupted Indian hedgehog (IHH) signal pathway and suppresses cell survival in human CS cells. However, the underlying mechanisms regulating the expression of GLI1 are still unknown. Here, we demonstrated the implication of GLI1 in SMO-independent pathways in CS cells. A GLI1 binding protein, major vault protein (MVP), was identified using the affinity purification method. MVP promoted the nuclear transport and stabilization of GLI1 by compromising the binding affinity of GLI1 with suppressor of fused homolog (SUFU) and increased GLI1 expression via mTOR/S6K1 signaling cascade. Functionally, knockdown of MVP suppressed cell growth and induced apoptosis. Simultaneous inhibition of MVP and GLI1 strongly inhibits the growth of CS in vitro and in vivo. Moreover, IHC results showed that MVP, GLI1, and P-p70S6K1 were highly expressed and positively correlated with each other in 71 human CS tissues. Overall, our findings revealed a novel regulating mechanism for HH-independent GLI1 expression and provide a rationale for combination therapy in patients with advanced CS.

scholarly journals TSC2-extracellular matrix crosstalk controls pulmonary vascular proliferation and pulmonary hypertension

2021 ◽  
Author(s):  
Yuanjun Shen ◽  
Dmitry A Goncharov ◽  
Andressa Pena ◽  
Jeffrey Baust ◽  
Andres Chavez Barragan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pulmonary Hypertension ◽  
Therapeutic Option ◽  
Pulmonary Arteries ◽  
Negative Regulator ◽  
Vascular Proliferation ◽  
Induced Apoptosis ◽  
Mtor Complex 1

Increased proliferation and survival of resident cells in small pulmonary arteries (PA) are important drivers of pulmonary hypertension (PH). Tuberous sclerosis complex 2 (TSC2) is a negative regulator of mTOR complex 1 and cell growth. Here we show that TSC2 is deficient in small remodeled PA/PA vascular smooth muscle cells (PAVSMC) from human PAH and experimental PH lungs. TSC2 deficiency was reproduced in vitro by maintaining PAVSMC on pathologically stiff substrates and was required for stiffness-induced proliferation, accumulation of transcriptional co-activators YAP/TAZ and up-regulation of mTOR. Depletion of TSC2 reproduced PH features in vitro in human PAVSMC and in vivo in SM22-Tsc2+/- mice. TSC2 loss in PAVSMC was supported by YAP and led to the up-regulation of YAP/TAZ and mTOR via modulating the extracellular matrix (ECM) composition. ECM, produced by TSC2-deficient PAVSMC, promoted growth of non-diseased PA adventitial fibroblasts and PAVSMC, which, in turn, was prevented by α5β1 integrin receptor antagonist ATN161. In vitro, molecular and pharmacological (SRT2104) restoration of TSC2 down-regulated YAP/TAZ, mTOR, and ECM pro-duction, inhibited proliferation and induced apoptosis in human PAH PAVSMC. In vivo, orally administrated SRT2104 restored TSC2, resolved pulmonary vascular remodeling, PH, and improved right heart in two rodent models of PH. Thus, PAVSMC TSC2 is a critical integrator of ECM composition and stiffness with pro-proliferative signaling and PH, and the restoration of functional TSC2 could be an attractive therapeutic option to treat PH.

scholarly journals Doxorubicin Induces Senescence in Intestinal Epithelial Cells

2021 ◽  
Author(s):  
Mandy Biraud ◽  
Jocsa Cortes ◽  
Paul Cray ◽  
Guy Kunzmann ◽  
Javid Mohammed ◽  
...  
Keyword(s):  
Dna Damage ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Homogeneous Population ◽  
Doxorubicin Treatment ◽  
Induced Apoptosis

AbstractDoxorubicin treatment induces DNA damage and apoptosis in rapidly dividing cell types like intestinal epithelial cells. This has been demonstrated both in vivo and in vitro. In certain cell types some cells do not undergo DNA damage-induced apoptosis in response to doxorubicin but instead become senescent. Induction of senescence in these cells can lead to dysfunction and chronic inflammation, which can lead to more damage. We questioned whether a single dose of doxorubicin would be able to induce apoptosis and senescence in intestinal epithelial cells in vitro. For these studies, we exposed IEC-6 small intestinal epithelial cells to doxorubicin to evaluate whether senescence is induced in a relatively homogeneous population of intestinal epithelial cells. Although some cells underwent apoptosis, those that did not showed traits of senescence. Our studies showed that doxorubicin treatment increased cell size and increased expression of senescence-associated β-galactosidase. Concomitantly, we observed increased mRNA expression of several genes associated with a senescence-associated secretory phenotype including IL-6, Ptges, Faim2, and Cdkn1a and decreased expression of Sirt1. We also observed release of HMGB1, a cellular alarmin, from treated cells. Together, these data suggest that doxorubicin induces senescence in intestinal epithelial cells. Furthermore, our data indicate that cellular responses to a DNA damaging agent, such as doxorubicin, can differ within a population of cells suggesting differing levels of sensitivity within a relatively homogenous cell population. Further studies are needed to delineate the mechanisms that determine whether a cell moves down an apoptotic or senescent pathway following DNA damage.

P5434P300-mediated inactivation of p53 protects against doxorubicin-induced cardiotoxicity

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M Adam ◽  
K K Singh ◽  
K A Connelly
Keyword(s):  
Dna Damage ◽  
Topoisomerase Ii ◽  
Caspase 3 ◽  
P53 Expression ◽  
Doxorubicin Treatment ◽  
Chemotherapy Drugs ◽  
Pre Treatment ◽  
Induced Apoptosis

Abstract Introduction Doxorubicin is amongst the most widely prescribed chemotherapy drugs due to its effectiveness in cancer treatment. However, progressive treatment using doxorubicin severely increases the risk of congestive heart failure. Mechanistically, researchers have shown that doxorubicin (i) intercalates into DNA and disrupts topoisomerase-II-mediated DNA repair and (ii) generates free radicals which then causes damage to cellular membranes, DNA, and proteins. Ultimately these cellular insults induce cardiomyocyte (CM) death mediated by the tumour suppressor, p53. Currently, there are no clinically applicable preventative treatments for doxorubicin-induced cardiotoxicity and so, extensive research is being done in discovering a potential therapy. One such candidate is curcumin – a natural polyphenol compound non-toxic to humans. We have previously demonstrated that curcumin inhibits lysine acetyltransferase activity of p300, therefore reducing both histone and non-histone protein acetylation. To induce CM death, p53 requires acetylation by p300. Therefore, we hypothesize that curcumin protects against doxorubicin-induced CM death and cardiotoxicity via p300-mediated inactivation of p53. Methods Rat H9c2 cardiomyoblast cells were cultured and treated with a 2.5 μM dose of doxorubicin for 16 hours. One group of cells were pre-treated with curcumin (15μM) 4 hours prior to doxorubicin treatment, and controls were cultured with only diluent added. Following treatment, the cells were harvested for total protein. At end point, we performed immunoblotting to measure protein expression of key proteins involved in DNA damage (y-H2A.X, p53), and apoptosis (cleaved-Caspase 3). Results Our findings show that following doxorubicin treatment, p53 expression was significantly increased (p<0.001), confirming its role in doxorubicin-associated cardiotoxicity. Furthermore, doxorubicin was associated with increased DNA-damage as evidenced by increased expression and activation of DNA double-stranded breaks (DSBs) marker, y-H2A.X (p<0.001). Elevated levels of DNA-damage were further associated with significantly increased doxorubicin-induced apoptosis as measured by immunoblotting for cleaved-Caspase 3 (p<0.001). However, DNA-damage and apoptosis were attenuated by pre-treatment of cells with curcumin. Curcumin treatment led to a significant decrease in both y-H2A.X (p<0.01) and cleaved-Caspase 3 (p<0.01) expression compared to cells treated with only doxorubicin. Conclusions Our data provides the first evidence that curcumin protects against doxorubicin-induced apoptosis in rat cardiomyoblast cells in vitro. Further studies are warranted in vivo to confirm the potential of curcumin as a cardio-protective drug. Curcumin is a natural compound with little to no side-effects in humans, therefore our finding may provide a novel therapeutic target and treatment approach for doxorubicin-associated cardiotoxicity. Acknowledgement/Funding Heart & Stroke Foundation of Canada

scholarly journals E2F3 Is a Mediator of DNA Damage-Induced Apoptosis

2009 ◽  
Vol 30 (2) ◽  
pp. 524-536 ◽  
Author(s):  
Luis A. Martinez ◽  
Elzbieta Goluszko ◽  
Hui-Zi Chen ◽  
Gustavo Leone ◽  
Sean Post ◽  
...  
Keyword(s):  
Dna Damage ◽  
Phosphorylation Site ◽  
Dependent Manner ◽  
The Novel ◽  
Checkpoint Kinases ◽  
Damage Response ◽  
E2f Transcription Factors ◽  
Induced Apoptosis

ABSTRACT The E2F transcription factors have emerged as critical apoptotic effectors. Herein we report that the E2F family member E2F3a can be induced by DNA damage through transcriptional and posttranslational mechanisms. We demonstrate that the posttranslational induction of human E2F3a is dependent on the checkpoint kinases. Moreover, we show that human E2F3a is a substrate for the checkpoint kinases (chk kinases) and that mutation of the chk phosphorylation site eliminates the DNA damage inducibility of the protein. Furthermore, we demonstrate that E2F1 and E2F2 are transcriptionally induced by DNA damage in an E2f3-dependent manner. Finally, using both in vitro and in vivo approaches, we establish that E2f3 is required for DNA damage-induced apoptosis. Thus, our data reveal the novel ability of E2f3 to function as a master regulator of the DNA damage response.

scholarly journals 18 Peroxiredoxin1 is a therapeutic target in group-3 medulloblastoma

2018 ◽  
Vol 45 (S3) ◽  
pp. S16-S16
Author(s):  
BV. Sajesh ◽  
OH. Ngoc ◽  
R. Omar ◽  
H. Fediuk ◽  
L. Li ◽  
...  
Keyword(s):  
Dna Damage ◽  
Therapeutic Target ◽  
Oxidative Dna Damage ◽  
Tumor Burden ◽  
In Vivo Studies ◽  
Orthotopic Model ◽  
Group 3 ◽  
Induced Apoptosis

Group-3 medulloblastoma (MBL) is highly resistant to radiation (IR) and chemotherapy and has the worst prognosis. Hence, there is an urgent need to elucidate targets that sensitize these tumors to chemotherapy and IR. Employing standard assays for viability and sensitization to IR, we identified PRDX1 as a therapeutic target in Group-3 MBL. Specifically, targeting PRDX1 by RNAi or inhibition by Adenanthin led to specific killing and sensitization to IR of Group-3 MBL cells. We rescued sensitization of Daoy and UW228 cells by hypermorphic expression of PRDX1. PRDX1 knockdown caused oxidative DNA damage and induced apoptosis. We correlated PRDX1 expression to patient outcomes in a validated MBL tumor-microarray. Whole genome sequencing identified pathways/genes that were dysregulated with PRDX1 inhibition or silencing. Our in vivo studies in mice employing flank/orthotopic tumors from patient derived xenografts/Group-3 MBL cells confirmed in vitro observations. Animals with tumors in which PRDX1 was targeted by RNAi or Adenanthin (using mini osmotic pumps) showed decreased tumor burden and increased survival when compared to controls. Since, Adenanthin does not cross the blood brain barrier (BBB) we used HAV6 peptide to transiently disrupt the BBB and deliver Adenanthin to the tumor. Immunohistochemistry confirmed that targeting PRDX1 resulted in increased oxidative DNA damage, apoptosis and decreased proliferation. In summary, we have validated PRDX1 as a therapeutic target in group-3 MBL, identified Adenanthin as a potent chemical inhibitor of PRDX1 and confirmed the role of HAV peptide (in the transient modulation of BBB permeability) in an orthotopic model of group-3 MBL.

scholarly journals p73α Regulation by Chk1 in Response to DNA Damage

2003 ◽  
Vol 23 (22) ◽  
pp. 8161-8171 ◽  
Author(s):  
Susana Gonzalez ◽  
Carol Prives ◽  
Carlos Cordon-Cardo
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Dna Damage Checkpoint ◽  
Biochemical Pathway ◽  
Checkpoint Kinase ◽  
Checkpoint Kinase 1 ◽  
Related Transcription Factor ◽  
Induced Apoptosis

ABSTRACT The checkpoint kinase 1 (Chk1) is an essential component of the DNA damage checkpoint. Previous studies have demonstrated an indispensable role for the p53-related transcription factor p73α in DNA damage-induced apoptosis. Here, we provide evidence that p73α is a target of Chk1. We found that endogenous p73α is serine phosphorylated by endogenous Chk1 upon DNA damage, which is a mechanism required for the apoptotic-inducing function of p73α. Consistent with this, we discovered that endogenous p73α interacts with Chk1 and is phosphorylated by Chk1 at serine 47 in vitro and in vivo. In contrast, Chk2 does not phosphorylate p73α in vitro. Moreover, mutation of serine 47 abolishes both Chk1-dependent phosphorylation of p73α upon DNA damage in vivo and the ability of Chk1 to upregulate the transactivation capacity of p73α. Our data indicate a novel biochemical pathway through which the p73α proapoptotic function requires DNA damage-triggered p73α phosphorylation by Chk1.

Sign in / Sign up

Export Citation Format

Share Document