scholarly journals Sirt6 Deacetylase: A Potential Key Regulator in the Prevention of Obesity, Diabetes and Neurodegenerative Disease

2020 ◽  
Vol 11 ◽  
Author(s):  
Swapnil Raj ◽  
Liston Augustine Dsouza ◽  
Shailendra Pratap Singh ◽  
Abhinav Kanwal

Sirtuins, NAD + dependent proteins belonging to class III histone deacetylases, are involved in regulating numerous cellular processes including cellular stress, insulin resistance, inflammation, mitochondrial biogenesis, chromatin silencing, cell cycle regulation, transcription, and apoptosis. Of the seven mammalian sirtuins present in humans, Sirt6 is an essential nuclear sirtuin. Until recently, Sirt6 was thought to regulate chromatin silencing, but new research indicates its role in aging, diabetes, cardiovascular disease, lipid metabolism, neurodegenerative diseases, and cancer. Various murine models demonstrate that Sirt6 activation is beneficial in alleviating many disease conditions and increasing lifespan, showing that Sirt6 is a critical therapeutic target in the treatment of various disease conditions in humans. Sirt6 also regulates the pathogenesis of multiple diseases by acting on histone proteins and non-histone proteins. Endogenous and non-endogenous modulators regulate both activation and inhibition of Sirt6. Few Sirt6 specific non-endogenous modulators have been identified. Hence the identification of Sirt6 specific modulators may have potential therapeutic roles in the diseases described above. In this review, we describe the development of Sirt6, the role it plays in the human condition, the functional role and therapeutic importance in disease processes, and specific modulators and molecular mechanism of Sirt6 in the regulation of metabolic homeostasis, cardiovascular disease, aging, and neurodegenerative disease.

2020 ◽  
Vol 4 (5) ◽  
Author(s):  
Nooshin Koolaji ◽  
Balakrishnan Shammugasamy ◽  
Aaron Schindeler ◽  
Qihan Dong ◽  
Fariba Dehghani ◽  
...  

ABSTRACT Citrus fruit and in particular flavonoid compounds from citrus peel have been identified as agents with utility in the treatment of cancer. This review provides a background and overview regarding the compounds found within citrus peel with putative anticancer potential as well as the associated in vitro and in vivo studies. Historical studies have identified a number of cellular processes that can be modulated by citrus peel flavonoids including cell proliferation, cell cycle regulation, apoptosis, metastasis, and angiogenesis. More recently, molecular studies have started to elucidate the underlying cell signaling pathways that are responsible for the flavonoids’ mechanism of action. These growing data support further research into the chemopreventative potential of citrus peel extracts, and purified flavonoids in particular. This critical review highlights new research in the field and synthesizes the pathways modulated by flavonoids and other polyphenolic compounds into a generalized schema.


2021 ◽  
pp. 1-9
Author(s):  
Fan Ye ◽  
Anshi Wu

Silent information-regulated transcription factor 1 (SIRT1) is the most prominent and widely studied member of the sirtuins (a family of mammalian class III histone deacetylases). It is a nuclear protein, and the deacetylation of the peroxisome proliferator-activated receptor coactivator-1 has been extensively implicated in metabolic control and mitochondrial biogenesis and is the basis for studies into its involvement in caloric restriction and its effects on lifespan. The present study discusses the potentially protective mechanism of SIRT1 in the regulation of the mitochondrial biogenesis and autophagy involved in the modulation of Alzheimer’s disease, which may be correlated with the role of SIRT1 in affecting neuronal morphology, learning, and memory during development; regulating metabolism; counteracting stress responses; and maintaining genomic stability. Drugs that activate SIRT1 may offer a promising approach to treating Alzheimer’s disease


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthew R. Swiatnicki ◽  
Eran R. Andrechek

AbstractThe E2F family of transcription factors is important for many cellular processes, from their canonical role in cell cycle regulation to other roles in angiogenesis and metastasis. Alteration of the Rb/E2F pathway occurs in various forms of cancer, including breast cancer. E2F1 ablation has been shown to decrease metastasis in MMTV-Neu and MMTV-PyMT transgenic mouse models of breast cancer. Here we take a bioinformatic approach to determine the E2F1 regulated genomic alterations involved in the metastatic cascade, in both Neu and PyMT models. Through gene expression analysis, we reveal few transcriptome changes in non-metastatic E2F1−/− tumors relative to transgenic tumor controls. However investigation of these models through whole genome sequencing found numerous differences between the models, including differences in the proposed tumor etiology between E2F1−/− and E2F1+/+ tumors induced by Neu or PyMT. For example, loss of E2F1 within the Neu model led to an increased contribution of the inefficient double stranded break repair signature to the proposed etiology of the tumors. While the SNV mutation burden was higher in PyMT mouse tumors than Neu mouse tumors, there was no statistically significant differences between E2F WT and E2F1 KO mice. Investigating mutated genes through gene set analysis also found a significant number of genes mutated in the cell adhesion pathway in E2F1−/− tumors, indicating this may be a route for disruption of metastasis in E2F1−/− tumors. Overall, these findings illustrate the complicated nature of uncovering drivers of the metastatic process.


Author(s):  
Catherine A. Powell ◽  
Jian Zhang ◽  
John D. Bowman ◽  
Mahua Choudhury

Cardiovascular disease (CVD) is the leading cause of death in both men and women and has largely been attributed to genetic makeup and lifestyle factors. However, genetic regulation does not fully explain the pathophysiology. Recently, epigenetic regulation, the regulation of the genetic code by modifications that affect the transcription and translation of target genes, has been shown to be important. Silent information regulator-2 proteins or sirtuins are an epigenetic regulator family of class III histone deacetylases (HDACs), unique in their dependency on coenzyme NAD+, that are postulated to mediate the beneficial effects of calorie restriction, thus promoting longevity by reducing the incidence of chronic diseases such as cancer, diabetes, and CVD. Emerging evidence shows that SIRT1 is ubiquitously expressed throughout the body. Resveratrol, a plant polyphenol, has cardioprotective effects and its mechanism of action is attributed to regulation of SIRT1. Incoproation of resveratrol into the diet may be a powerful therapeutic option for the prevention and treatment of CVD.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3287 ◽  
Author(s):  
Berin Karaman Mayack ◽  
Wolfgang Sippl ◽  
Fidele Ntie-Kang

Natural products have been used for the treatment of human diseases since ancient history. Over time, due to the lack of precise tools and techniques for the separation, purification, and structural elucidation of active constituents in natural resources there has been a decline in financial support and efforts in characterization of natural products. Advances in the design of chemical compounds and the understanding of their functions is of pharmacological importance for the biomedical field. However, natural products regained attention as sources of novel drug candidates upon recent developments and progress in technology. Natural compounds were shown to bear an inherent ability to bind to biomacromolecules and cover an unparalleled chemical space in comparison to most libraries used for high-throughput screening. Thus, natural products hold a great potential for the drug discovery of new scaffolds for therapeutic targets such as sirtuins. Sirtuins are Class III histone deacetylases that have been linked to many diseases such as Parkinson`s disease, Alzheimer’s disease, type II diabetes, and cancer linked to aging. In this review, we examine the revitalization of interest in natural products for drug discovery and discuss natural product modulators of sirtuins that could serve as a starting point for the development of isoform selective and highly potent drug-like compounds, as well as the potential application of naturally occurring sirtuin inhibitors in human health and those in clinical trials.


2007 ◽  
Vol 15 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Simone de Oliveira Camillo ◽  
Ana Lúcia da Silva ◽  
Alan Jefferson do Nascimento

This study aimed to identify and interpret the perceptions presented by undergraduate students of a Nursing course after internship in Mental Health. Twelve nursing undergraduate students at the Nursing School of ABC Foundation - Santo André, São Paulo, Brazil were interviewed. These interviews using a semi-structure script were performed and recorded in August 2004. Through Content Analysis, thematic modality, four categories were identified, 1. mental health: providing understanding of the other; 2. respect for the human being: the importance of listening, 3. mental health: contributing for a contextualized view of the patient and 4. nursing graduation: undesirable "signs and symptoms" of the profession. The analysis and the discussion of these categories suggest the possibility of teaching based on the human condition. Thus, we support the idea of new research been carried out, considering that the Mental Health discipline must be valued in the Political and Pedagogical projects of the Nursing Undergraduate Courses.


2013 ◽  
Vol 91 (3) ◽  
pp. 213-220 ◽  
Author(s):  
Biao Feng ◽  
Michael Anthony Ruiz ◽  
Subrata Chakrabarti

Oxidative stress plays an important role in the development and progression of chronic diabetic complications. Diabetes causes mitochondrial superoxide overproduction in the endothelial cells of both large and small vessels. This increased superoxide production causes the activation of several signal pathways involved in the pathogenesis of chronic complications. In particular, endothelial cells are major targets of glucose-induced oxidative damage in the target organs. Oxidative stress activates cellular signaling pathways and transcription factors in endothelial cells including protein kinase C (PKC), c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), forkhead box O (FOXO), and nuclear factor kappa-B (NF-κB). Oxidative stress also causes DNA damage and activates DNA nucleotide excision repair enzymes including the excision repair cross complimenting 1(ERCC1), ERCC4, and poly(ADP-ribose) polymerase (PARP). Augmented production of histone acetyltransferase p300, and alterations of histone deacetylases, including class III deacetylases sirtuins, are also involved in this process. Recent research has found that small noncoding RNAs, like microRNA, are a new kind of regulator associated with chronic diabetic complications. There are extensive and complicated interactions and among these molecules. The purpose of this review is to demonstrate the role of oxidative stress in the development of diabetic complications in relation to epigenetic changes such as acetylation and microRNA alterations.


2018 ◽  
Vol 30 (1) ◽  
pp. 167
Author(s):  
M. G. Kim ◽  
S. T. Shin ◽  
H. D. Shin ◽  
H. T. Lee

Sirtuin (Sirt), nicotinamide adenine dinucleotide dependent class III histone deacetylase, plays an important role in cellular processes including DNA repair, apoptosis, cell cycle, aging, and determining lifespan. In previous studies, levels of Sirt1 to Sirt3 mRNA were detected in porcine embryos for the first time and levels are lower in blastocysts relative to matured oocytes. In addition, mitochondrial dysfunction and hyperglycemia increases LC3 protein levels and apoptosis in porcine parthenotic embryos and modulation of autophagy also influences apoptosis, mitochondrial contents, abnormal autophagosome formation, and maternal mRNA degradation. However, Sirt-mediated mechanisms have not been examined in in vitro-produced embryos of pig. Therefore, we investigated the relationship between Sirt inhibition and autophagy/mitophagy in porcine pre-implantation embryos. After IVF, embryos were cultured in NCSU-23 media in the presence and absence of 100 μM sirtinol (Sirt inhibitor) until the expended blastocyst stage. As a result, there were no significant differences between the rate of cleavage in control (69.22 ± 1.29) and treated groups (72.66 ± 1.08). However, embryos treated with sirtinol had significantly decreased developmental rates to the morula as well as blastocyst stages. Especially, expanded blastocysts (9.90 ± 1.56 v. 2.92 ± 0.94%) were barely observed in sirtinol-treated group. In the levels of Sirt transcripts, Sirt2 mRNA was significantly lower in sirtinol-treated blastocysts compared with controls (P < 0.05), but the levels of Sirt1 and Sirt3 mRNA were similar in both groups. In addition, we found that sirtinol treatment induced autophagy by increasing the expressions of LC3, Beclin1, and ATG5 in blastocysts. Furthermore, we observed that the abundance of mitochondria stained with mitotracker was lower in sirtinol-treated blastocysts than that of control. Finally, we found that sirtinol treatment resulted in a higher total apoptotic index (6.88 ± 0.84) compared with the control (12.84 ± 0.99) in blastocysts. In summary, our findings in this study demonstrated that Sirt inhibition by sirtinol led to lower levels of Sirt2 transcript in blastocysts, reduced developmental capability and embryo quality with regulation of ATGs, LC3 proteins, apoptosis-related genes, and mitochondrial abundance. Therefore, these results suggest that Sirt2 may play an important role in the pre-implantation development of porcine embryos and their quality through the regulation of autophagy/mitophagy and apoptosis pathways. This research was supported by a Grant from the Bio & Medical Technology Development Program (2015M3A9C7030091) of the National Research Foundation (NRF) funded by the Korean government.


2020 ◽  
Vol 21 (18) ◽  
pp. 6686
Author(s):  
Yu Ah Hong ◽  
Ji Eun Kim ◽  
Minjee Jo ◽  
Gang-Jee Ko

Sirtuins (SIRTs) are class III histone deacetylases (HDACs) that play important roles in aging and a wide range of cellular functions. Sirtuins are crucial to numerous biological processes, including proliferation, DNA repair, mitochondrial energy homeostasis, and antioxidant activity. Mammals have seven different sirtuins, SIRT1–7, and the diverse biological functions of each sirtuin are due to differences in subcellular localization, expression profiles, and cellular substrates. In this review, we summarize research advances into the role of sirtuins in the pathogenesis of various kidney diseases including acute kidney injury, diabetic kidney disease, renal fibrosis, and kidney aging along with the possible underlying molecular mechanisms. The available evidence indicates that sirtuins have great potential as novel therapeutic targets for the prevention and treatment of kidney diseases.


2002 ◽  
Vol 76 (6) ◽  
pp. 2990-2996 ◽  
Author(s):  
Mary L. Spengler ◽  
Karen Kurapatwinski ◽  
Adrian R. Black ◽  
Jane Azizkhan-Clifford

ABSTRACT Human cytomegalovirus (HCMV) immediate-early protein IE1/IE72 is involved in undermining many cellular processes including cell cycle regulation, apoptosis, nuclear architecture, and gene expression. The multifunctional nature of IE72 suggests that posttranslational modifications may modulate its activities. IE72 is a phosphoprotein and has intrinsic kinase activity (S. Pajovic, E. L. Wong, A. R. Black, and J. C. Azizkhan, Mol. Cell. Biol. 17:6459-6464, 1997). We now demonstrate that IE72 is covalently conjugated to the small ubiquitin-like modifier (SUMO-1). SUMO-1 is an 11.5-kDa protein that is conjugated to multiple proteins and has been reported to exhibit multiple effects, including modulation of protein stability, subcellular localization, and gene expression. A covalently modified protein migrating at ∼92 kDa, which is stabilized by a SUMO-1 hydrolase inhibitor, is revealed by Western blotting with anti-IE72 of lysates from cells infected with HCMV or cells expressing IE72. SUMO modification of IE72 was confirmed by immunoprecipitation with anti-IE72 and anti-SUMO-1 followed by Western blotting with anti-SUMO-1 and anti-IE72, respectively. Lysine 450 is within a sumoylation consensus site (I,V,L)KXE; changing lysine 450 to arginine by point mutation abolishes SUMO-1 modification of IE72. Inhibition of protein phosphatase 1 and 2A, which increases the phosphorylation of IE72, suppresses the formation of SUMO-1-IE72 conjugates. Both wild-type IE72 and IE72K450R localize to nuclear PML oncogenic domains and disrupt them. Studies of protein stability, transactivation, and complementation of IE72-deficient HCMV (CR208) have revealed no significant differences between wild-type IE72 and IE72K450R.


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