scholarly journals Role of Nicotinamide in DNA Damage, Mutagenesis, and DNA Repair

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Devita Surjana ◽  
Gary M. Halliday ◽  
Diona L. Damian
Keyword(s):  
Dna Repair ◽  
Cellular Responses ◽  
Water Soluble ◽  
Vitamin B3 ◽  
Atp Production ◽  
Amide Form ◽  
Parp 1

Nicotinamide is a water-soluble amide form of niacin (nicotinic acid or vitamin B3). Both niacin and nicotinamide are widely available in plant and animal foods, and niacin can also be endogenously synthesized in the liver from dietary tryptophan. Nicotinamide is also commercially available in vitamin supplements and in a range of cosmetic, hair, and skin preparations. Nicotinamide is the primary precursor of nicotinamide adenine dinucleotide (NAD+), an essential coenzyme in ATP production and the sole substrate of the nuclear enzyme poly-ADP-ribose polymerase-1 (PARP-1). Numerousin vitroandin vivostudies have clearly shown that PARP-1 and NAD+status influence cellular responses to genotoxicity which can lead to mutagenesis and cancer formation. This paper will examine the role of nicotinamide in the protection from carcinogenesis, DNA repair, and maintenance of genomic stability.

scholarly journals The Role of Herbal Bioactive Components in Mitochondria Function and Cancer Therapy

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fangfang Tao ◽  
Yanrong Zhang ◽  
Zhiqian Zhang
Keyword(s):  
Cancer Therapy ◽  
Cancer Cell ◽  
Apoptotic Cell ◽  
Redox Status ◽  
Cancer Therapies ◽  
Bioactive Components ◽  
Atp Production

Mitochondria are highly dynamic double-membrane organelles which play a well-recognized role in ATP production, calcium homeostasis, oxidation-reduction (redox) status, apoptotic cell death, and inflammation. Dysfunction of mitochondria has long been observed in a number of human diseases, including cancer. Targeting mitochondria metabolism in tumors as a cancer therapeutic strategy has attracted much attention for researchers in recent years due to the essential role of mitochondria in cancer cell growth, apoptosis, and progression. On the other hand, a series of studies have indicated that traditional medicinal herbs, including traditional Chinese medicines (TCM), exert their potential anticancer effects as an effective adjunct treatment for alleviating the systemic side effects of conventional cancer therapies, for reducing the risk of recurrence and cancer mortality and for improving the quality of patients’ life. An amazing feature of these structurally diverse bioactive components is that majority of them target mitochondria to provoke cancer cell-specific death program. The aim of this review is to summarize the in vitro and in vivo studies about the role of these herbs, especially their bioactive compounds in the modulation of the disturbed mitochondrial function for cancer therapy.

Abstract MP247: Mitochondrial Complex V Is Regulated By GRK2 In The Heart

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Kimberly Ferrero ◽  
Jessica M Pfleger ◽  
Kurt Chuprun ◽  
Eric Barr ◽  
Erhe Gao ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Cardiac Injury ◽  
Atp Synthesis ◽  
Cardiac Metabolism ◽  
Neonatal Rat ◽  
Interacting Proteins ◽  
Atp Production

The GPCR kinase GRK2 is highly expressed the heart; importantly, during cardiac injury or heart failure (HF) both levels and activity of GRK2 increase. The role of GRK2 during HF is canonically studied upstream of β-adrenergic desensitization. However, GRK2 has a large interactome and noncanonical functions for this kinase are being uncovered. We have discovered that in the heart, GRK2 translocates to mitochondria ( mtGRK2 ) following injury and is associated with negative effects on cardiac metabolism. Thus, we have sought to identify the mechanism(s) by which GRK2 can regulate mitochondrial function. We hypothesize that mtGRK2 interacts with proteins which regulate bioenergetics and substrate utilization, and this never-before-described role may partially explain the altered mitochondrial phenotype seen following cardiac injury or HF. Stress-induced mitochondrial translocation of GRK2 was validated in neonatal rat ventricular myocytes, murine heart tissue and a cardiac-derived cell line. Consequently, the GRK2 interactome was mapped basally and under stress conditions in vitro, in vivo , and with tagged recombinant peptides. GRK2-interacting proteins were isolated via immunoprecipitation and analyzed via liquid chromatography-mass spectroscopy (LCMS). Proteomics analysis (IPA; Qiagen) identified mtGRK2 interacting proteins which were also involved in mitochondrial dysfunction. Excitingly, Complexes I, II, IV and V (ATP synthase) of the electron transport chain (ETC) were identified in the subset of mtGRK2-dysfunction partners. Several mtGRK2-ETC interactions were increased following stress, particularly those in Complex V. We further established that mtGRK2 phosphorylates some of the subunits of Complex V, particularly the ATP synthase barrel which is critical for ATP production in the heart. Specific amino acid residues on these subunits have been identified using PTM-LCMS and are currently being validated in a murine model of myocardial infarction. To support these data, we have also determined that alterations in either the levels or kinase activity of GRK2 appear to alter the enzymatic activity of Complex V in vitro , thus altering ATP production. In summary, the phosphorylation of the ATP synthesis machinery by mtGRK2 may be regulating some of the phenotypic effects of injured or failing hearts such as increased ROS production and reduced fatty acid metabolism. Research is ongoing in our lab to elucidate the novel role of GRK2 in regulating mitochondrial bioenergetics and cell death, thus uncovering an exciting, druggable novel target for rescuing cardiac function in patients with injured and/or failing hearts.

scholarly journals Ryanodine Receptor 1-mediated Ca2+ signaling and mitochondrial reprogramming modulate uterine serous cancer malignant phenotypes

2021 ◽  
Author(s):  
Li Zhang ◽  
Chunxian Huang ◽  
Tsz-Lun Yeung ◽  
Sammy Ferri-Borgogno ◽  
Chilam AuYeung ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Ryanodine Receptor ◽  
Functional Role ◽  
Patient Survival ◽  
Uterine Cancer ◽  
Atp Production ◽  
Ryanodine Receptor 1

Abstract Background Uterine serous cancer (USC) is the most common non-endometrioid subtype of uterine cancer, and is also the most aggressive. Most patients will die of progressively chemotherapy-resistant disease, and the development of new therapies that can target USC remains a major unmet clinical need. This study sought to determine the molecular mechanism by which a novel unfavorable prognostic biomarker RYR1 identified in advanced USC confers their malignant phenotypes, and demonstrated the efficacy of targeting RYR1 by repositioned FDA-approved compounds in USC treatment. Methods TCGA USC dataset was analyzed to identify top genes that are associated with patient survival and can be targeted by FDA-approved compounds. The top gene RYR1 was selected and the functional role of RYR1 in USC progression was determined by silencing and over-expressing RYR1 in USC cells in vitro and in vivo. The molecular mechanism and signaling networks associated with the functional role of RYR1 in USC progression were determined by reverse phase protein arrays (RPPA), Western blot, and transcriptomic profiling analyses. The efficacy of the repositioned compound dantrolene on USC progression was determined using both in vitro and in vivo models. Results High expression level of ryanodine receptor 1 (RYR1) in the tumors is associated with shortened overall survival. Inhibition of RYR1 suppressed proliferation, migration and enhanced apoptosis through the Ca2+-dependent AKT/CREB/PGC-1α and AKT/HK1/2 signaling pathways, which modulate mitochondrial bioenergetics properties, including oxidative phosphorylation, ATP production, mitochondrial membrane potential, ROS production and TCA metabolites, and glycolytic activities in USC cells. Repositioned compound dantrolene suppressed USC progression in both in vitro and mouse models. Conclusions These findings provide insight into the mechanism by which RYR1 modulates the malignant phenotypes of USC and could aid in the development of dantrolene as a repurposed therapeutic agent for the treatment of USC to improve patient survival.

Targeting DNA Repair Systems in Antitubercular Drug Development

2019 ◽  
Vol 26 (8) ◽  
pp. 1494-1505 ◽  
Author(s):  
Alina Minias ◽  
Anna Brzostek ◽  
Jarosław Dziadek
Keyword(s):  
Dna Repair ◽  
Protein Crystal ◽  
Model Organisms ◽  
Dna Repair Genes ◽  
Associated Proteins ◽  
Related Proteins ◽  
Repair Genes

Infections with Mycobacterium tuberculosis, the causative agent of tuberculosis, are difficult to treat using currently available chemotherapeutics. Clinicians agree on the urgent need for novel drugs to treat tuberculosis. In this mini review, we summarize data that prompts the consideration of DNA repair-associated proteins as targets for the development of new antitubercular compounds. We discuss data, including gene expression data, that highlight the importance of DNA repair genes during the pathogenic cycle as well as after exposure to antimicrobials currently in use. Specifically, we report experiments on determining the essentiality of DNA repair-related genes. We report the availability of protein crystal structures and summarize discovered protein inhibitors. Further, we describe phenotypes of available gene mutants of M. tuberculosis and model organisms Mycobacterium bovis and Mycobacterium smegmatis. We summarize experiments regarding the role of DNA repair-related proteins in pathogenesis and virulence performed both in vitro and in vivo during the infection of macrophages and animals. We detail the role of DNA repair genes in acquiring mutations, which influence the rate of drug resistance acquisition.

scholarly journals Nanostructures Control the Hepatocellular Responses to a Cytotoxic Agent “Cisplatin”

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Shimaa A. Abdellatef ◽  
Riho Tange ◽  
Takeshi Sato ◽  
Akihiko Ohi ◽  
Toshihide Nabatame ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Chemotherapeutic Agent ◽  
Chromatin Condensation ◽  
Cellular Responses ◽  
Flat Surfaces ◽  
Flat Substrate ◽  
Cells Cultured

In drug discovery programs, the alteration betweenin vivoandin vitrocellular responses to drug represents one of the main challenges. Since the variation in the native extracellular matrix (ECM) betweenin vivoand 2Din vitroconditions is one of the key reasons for such discrepancies, thus the utilization of substrate that likely mimics ECM characteristics (topography, stiffness, and chemical composition) is needed to overcome such problem. Here, we investigated the role of substrate nanotopography as one of the major determinants of hepatic cellular responses to a chemotherapeutic agent “cisplatin.” We studied the substratum induced variations in cisplatin cytotoxicity; a higher cytotoxic response to cisplatin was observed for cells cultured on the nanopattern relative to a flat substrate. Moreover, the nanofeatures with grating shapes that mimic the topography of major ECM protein constituents (collagen) induced alterations in the cellular orientation and chromatin condensation compared to flat surfaces. Accordingly, the developments of biomimetic substrates with a particular topography could have potentials in drug development analyses to reflect more physiological mimicry conditionsin vitro.

Role of calcium in metabolic signaling between cardiac sarcoplasmic reticulum and mitochondria in vitro

2003 ◽  
Vol 284 (2) ◽  
pp. C285-C293 ◽  
Author(s):  
Robert S. Balaban ◽  
Salil Bose ◽  
Stephanie A. French ◽  
Paul R. Territo
Keyword(s):  
Energy Metabolism ◽  
Sarcoplasmic Reticulum ◽  
Atp Synthesis ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Atp Production ◽  
Wide Range ◽  
Reconstituted System

The role of Ca2+ as a cytosolic signaling molecule between porcine cardiac sarcoplasmic reticulum (SR) ATPase and mitochondrial ATP production was evaluated in vitro. The Ca2+ sensitivity of these processes was determined individually and in a reconstituted system with SR and mitochondria in a 0.5:1 protein-to-cytochrome aa 3 ratio. The half-maximal concentration ( K 1/2) of SR ATPase was 335 nM Ca2+. The ATP synthesis dependence was similar with a K 1/2 of 243 nM for dehydrogenases and 114 nM for overall ATP production. In the reconstituted system, Ca2+ increased thapsigargin-sensitive ATP production (maximum ∼5-fold) with minimal changes in mitochondrial reduced nicotinamide adenine dinucleotide (NADH). NADH concentration remained stable despite graded increases in NADH turnover induced over a wide range of Ca2+ concentrations (0 to ∼500 nM). These data are consistent with a balanced activation of SR ATPase and mitochondrial ATP synthesis by Ca2+ that contributes to a homeostasis of energy metabolism metabolites. It is suggested that this balanced activation by cytosolic Ca2+ is partially responsible for the minimal alteration in energy metabolism intermediates that occurs with changes in cardiac workload in vivo.

scholarly journals UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Jingyuan Sun ◽  
Zhenru Zhu ◽  
Wenwen Li ◽  
Mengying Shen ◽  
Chuanhui Cao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Dna Repair ◽  
Clinical Data ◽  
Underlying Mechanism ◽  
Cell Cycle Checkpoint ◽  
Cell Cycle Checkpoints

Abstract Background Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patients. However, the underlying mechanism have not been clearly understood. Methods We obtained 7 pairs of HCC tissues and corresponding non-tumor tissues, and UBE2T was identified as one of the most upregulated genes. The radioresistant role of UBE2T was examined by colony formation assays in vitro and xenograft tumor models in vivo. Comet assay, cell cycle flow cytometry and γH2AX foci measurement were used to investigate the mechanism by which UBE2T mediating DDR. Chromatin fractionation and immunofluorescence staining were used to assess cell cycle checkpoint kinase 1(CHK1) activation. Finally, we analyzed clinical data from HCC patients to verify the function of UBE2T. Results Here, we found that ubiquitin-conjugating enzyme E2T (UBE2T) was upregulated in HCC tissues, and the HCC patients with higher UBE2T levels exhibited poorer outcomes. Functional studies indicated that UBE2T increased HCC radioresistance in vitro and in vivo. Mechanistically, UBE2T-RNF8, was identified as the E2-E3 pair, physically bonded with and monoubiquitinated histone variant H2AX/γH2AX upon radiation exposure. UBE2T-regulated H2AX/γH2AX monoubiquitination facilitated phosphorylation of CHK1 for activation and CHK1 release from the chromatin to cytosol for degradation. The interruption of UBE2T-mediated monoubiquitination on H2AX/γH2AX, including E2-enzyme-deficient mutation (C86A) of UBE2T and monoubiquitination-site-deficient mutation (K119/120R) of H2AX, cannot effectively activate CHK1. Moreover, genetical and pharmacological inhibition of CHK1 impaired the radioresistant role of UBE2T in HCC. Furthermore, clinical data suggested that the HCC patients with higher UBE2T levels exhibited worse response to radiotherapy. Conclusion Our results revealed a novel role of UBE2T-mediated H2AX/γH2AX monoubiquitination on facilitating cell cycle arrest activation to provide sufficient time for radiation-induced DNA repair, thus conferring HCC radioresistance. This study indicated that disrupting UBE2T-H2AX-CHK1 pathway maybe a promising potential strategy to overcome HCC radioresistance.

scholarly journals Endothelial-specific Crif1 deletion induces BBB maturation and disruption via the alteration of actin dynamics by impaired mitochondrial respiration

2020 ◽  
Vol 40 (7) ◽  
pp. 1546-1561
Author(s):  
Min Joung Lee ◽  
Yunseon Jang ◽  
Jeongsu Han ◽  
Soo J Kim ◽  
Xianshu Ju ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Motor Behavior ◽  
Actin Dynamics ◽  
Toxic Substances ◽  
Atp Production ◽  
Junctional Proteins ◽  
Peripheral Immune Cells

Cerebral endothelial cells (ECs) require junctional proteins to maintain blood–brain barrier (BBB) integrity, restricting toxic substances and controlling peripheral immune cells with a higher concentration of mitochondria than ECs of peripheral capillaries. The mechanism underlying BBB disruption by defective mitochondrial oxidative phosphorylation (OxPhos) is unclear in a mitochondria-related gene-targeted animal model. To assess the role of EC mitochondrial OxPhos function in the maintenance of the BBB, we developed an EC-specific CR6-interactin factor1 ( Crif1) deletion mouse. We clearly observed defects in motor behavior, uncompacted myelin and leukocyte infiltration caused by BBB maturation and disruption in this mice. Furthermore, we investigated the alteration in the actin cytoskeleton, which interacts with junctional proteins to support BBB integrity. Loss of Crif1 led to reorganization of the actin cytoskeleton and a decrease in tight junction-associated protein expression through an ATP production defect in vitro and in vivo. Based on these results, we suggest that mitochondrial OxPhos is important for the maturation and maintenance of BBB integrity by supplying ATP to cerebral ECs.

Abstract P370: The Role Of PJ-34 In The Protection Of Burn-induced Cardiomyopathy

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Jake J Wen ◽  
Ravi Radhakrishnan ◽  
Keyan Mobli ◽  
Geetha L Radhakrishnan
Keyword(s):  
Oxidative Stress ◽  
Culture Medium ◽  
Burn Injury ◽  
Sirtuin 1 ◽  
Post Translational Modification ◽  
Post Injury ◽  
Parp 1

Burn injury results in adverse myocardial remodeling and heart failure through circulatingcatecholamines and androgen and cytokine cascades. The DNA binding protein PARP1(poly ADP ribose polymerase 1) catalyzes a post translational modification to generatePARylation proteins,which changes the normal function of the modified proteins. Bothof PARP-1 and SIRT1 (sirtuin1) are NAD + dependent. In this study, we propose that PJ34 (PARP-1 inhibitor) would protect the function of burn-remodeled cardiomyocytes.Commercial rats were obtained and were subject to 60% total surface body area (TSBA)scald burns by immersing the abdomen and back in boiling water. They were immediatelytreated with the PJ34 post injury. Separately, the cardiomyocytes (Ac16) were exposedto burn-serum replaced culture medium with or without treatment of lentivirus-PARP1 KOand/or SIRT-PGC-1α agonists in vitro . The in vivo experiments showed that burn-ratsexhibited cardiac hypertrophy, fibrosis and an increase in the inflammatory markers IL-1β, IFN-γ and TNFα. Burned rats had an increased oxidative stress, concomitant withelevated PARP-1 activity and reduced Sirtuin-1 (SIRT1) expression. PJ34 treatment ledto increased SIRT1 and Peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) levels and attenuated oxidative stress, inflammation, and fibrosis. In vitro tests demonstrated that the treatments of PJ34 and SIRT1-PGC-1α axis agonists incardiomyocytes exposed to burn-serum replaced culture medium led to a significantreduction in mit ROS and mitochondrial dysfunction. In Conclusion, PARP1 depletion byPJ34 in vivo and Letivirus-PARP1 KO Ac16 in vitro attenuated cardiomyopathic featuresin burn-rats through the activation of SIRT1 and its downstream antioxidant defensemechanisms. The results of this study suggest a pivotal role of PARP-1 inhibition intreating burn-induced cardiomyopathy. Keywords: Burn injury; PJ34; PARP1; Cardiomyocyte; Lentivirus.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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