PPARγ preservation via promoter demethylation alleviates osteoarthritis in mice

2019 ◽  
Vol 78 (10) ◽  
pp. 1420-1429 ◽  
Author(s):  
Xiaobo Zhu ◽  
Fang Chen ◽  
Ke Lu ◽  
Ai Wei ◽  
Qing Jiang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Knockout Mice ◽  
Cartilage Damage ◽  
Critical Role ◽  
Methylation Status ◽  
Promoter Hypermethylation ◽  
Dna Methyltransferases ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Peroxisome Proliferator

ObjectivesOsteoarthritis (OA) is the most common degenerative joint disease in aged population and its development is significantly influenced by aberrant epigenetic modifications of numerous OA susceptible genes; however, the precise mechanisms that DNA methylation alterations affect OA pathogenesis remain undefined. This study investigates the critical role of epigenetic PPARγ (peroxisome proliferator–activated receptor-gamma) suppression in OA development.MethodsArticular cartilage expressions of PPARγ and bioactive DNA methyltransferases (DNMTs) from OA patients and mice incurred by DMM (destabilisation of medial meniscus) were examined. DNA methylation status of both human and mouse PPARγ promoters were assessed by methylated specific PCR and/or bisulfite-sequencing PCR. OA protections by a pharmacological DNA demethylating agent 5Aza (5-Aza-2'-deoxycytidine) were compared between wild type and PPARγ knockout mice.ResultsArticular cartilages from both OA patients and DMM mice display substantial PPARγ suppressions likely due to aberrant elevations of DNMT1 and DNMT3a and consequential PPARγ promoter hypermethylation. 5Aza known to inhibit both DNMT1 and DNMT3a reversed the PPARγ promoter hypermethylation, recovered the PPARγ loss and effectively attenuated the cartilage damage in OA mice. 5Aza also inhibited the OA-associated excessive inflammatory cytokines and deficit anti-oxidant enzymes, which were blocked by a specific PPARγ inhibitor in cultured chondrocytes. Further, 5Aza-confered protections against the cartilage damage and the associated abnormalities of OA-susceptible factors were significantly abrogated in PPARγ knockout mice.ConclusionEpigenetic PPARγ suppression plays a key role in OA development and PPARγ preservation via promoter demethylation possesses promising therapeutic potentials in clinical treatment of OA and the related joint diseases.

scholarly journals DNA methylome signatures of prenatal exposure to synthetic glucocorticoids in hippocampus and peripheral whole blood of female guinea pigs in early life

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aya Sasaki ◽  
Margaret E. Eng ◽  
Abigail H. Lee ◽  
Alisa Kostaki ◽  
Stephen G. Matthews
Keyword(s):  
Dna Methylation ◽  
Whole Blood ◽  
Guinea Pigs ◽  
Critical Role ◽  
Methylation Status ◽  
Peripheral Tissues ◽  
Epigenetic Biomarkers ◽  
Differentially Methylated Genes ◽  
Increased Risk ◽  
Synthetic Glucocorticoids

AbstractSynthetic glucocorticoids (sGC) are administered to women at risk of preterm delivery, approximately 10% of all pregnancies. In animal models, offspring exposed to elevated glucocorticoids, either by administration of sGC or endogenous glucocorticoids as a result of maternal stress, show increased risk of developing behavioral, endocrine, and metabolic dysregulation. DNA methylation may play a critical role in long-lasting programming of gene regulation underlying these phenotypes. However, peripheral tissues such as blood are often the only accessible source of DNA for epigenetic analyses in humans. Here, we examined the hypothesis that prenatal sGC administration alters DNA methylation signatures in guinea pig offspring hippocampus and whole blood. We compared these signatures across the two tissue types to assess epigenetic biomarkers of common molecular pathways affected by sGC exposure. Guinea pigs were treated with sGC or saline in late gestation. Genome-wide modifications of DNA methylation were analyzed at single nucleotide resolution using reduced representation bisulfite sequencing in juvenile female offspring. Results indicate that there are tissue-specific as well as common methylation signatures of prenatal sGC exposure. Over 90% of the common methylation signatures associated with sGC exposure showed the same directionality of change in methylation. Among differentially methylated genes, 134 were modified in both hippocampus and blood, of which 61 showed methylation changes at identical CpG sites. Gene pathway analyses indicated that prenatal sGC exposure alters the methylation status of gene clusters involved in brain development. These data indicate concordance across tissues of epigenetic programming in response to alterations in glucocorticoid signaling.

scholarly journals Epigenetic Contribution and Genomic Imprinting Dlk1-Dio3 miRNAs in Systemic Lupus Erythematosus

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 680
Author(s):  
Rujuan Dai ◽  
Zhuang Wang ◽  
S. Ansar Ahmed
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Dna Methylation ◽  
Lupus Erythematosus ◽  
Critical Role ◽  
Methylation Status ◽  
Transcriptional Level ◽  
Dna Hypomethylation ◽  
Systemic Lupus ◽  
Multiple Organs ◽  
Genetic Imprinting

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease that afflicts multiple organs, especially kidneys and joints. In addition to genetic predisposition, it is now evident that DNA methylation and microRNAs (miRNAs), the two major epigenetic modifications, are critically involved in the pathogenesis of SLE. DNA methylation regulates promoter accessibility and gene expression at the transcriptional level by adding a methyl group to 5′ cytosine within a CpG dinucleotide. Extensive evidence now supports the importance of DNA hypomethylation in SLE etiology. miRNAs are small, non-protein coding RNAs that play a critical role in the regulation of genome expression. Various studies have identified the signature lupus-related miRNAs and their functional contribution to lupus incidence and progression. In this review, the mutual interaction between DNA methylation and miRNAs regulation in SLE is discussed. Some lupus-associated miRNAs regulate DNA methylation status by targeting the DNA methylation enzymes or methylation pathway-related proteins. On the other hand, DNA hyper- and hypo-methylation are linked with dysregulated miRNAs expression in lupus. Further, we specifically discuss the genetic imprinting Dlk1-Dio3 miRNAs that are subjected to DNA methylation regulation and are dysregulated in several autoimmune diseases, including SLE.

scholarly journals Polyamine Metabolism and Gene Methylation in Conjunction with One-Carbon Metabolism

2018 ◽  
Vol 19 (10) ◽  
pp. 3106 ◽  
Author(s):  
Kuniyasu Soda
Keyword(s):  
Dna Methylation ◽  
Carbon Metabolism ◽  
Methylation Status ◽  
Significant Risk ◽  
Significant Risk Factor ◽  
Dna Methyltransferases ◽  
Polyamine Metabolism ◽  
Methyl Group ◽  
Wide Range ◽  
One Carbon Metabolism

Recent investigations have revealed that changes in DNA methylation status play an important role in aging-associated pathologies and lifespan. The methylation of DNA is regulated by DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) in the presence of S-adenosylmethionine (SAM), which serves as a methyl group donor. Increased availability of SAM enhances DNMT activity, while its metabolites, S-adenosyl-l-homocysteine (SAH) and decarboxylated S-adenosylmethionine (dcSAM), act to inhibit DNMT activity. SAH, which is converted from SAM by adding a methyl group to cytosine residues in DNA, is an intermediate precursor of homocysteine. dcSAM, converted from SAM by the enzymatic activity of adenosylmethionine decarboxylase, provides an aminopropyl group to synthesize the polyamines spermine and spermidine. Increased homocysteine levels are a significant risk factor for the development of a wide range of conditions, including cardiovascular diseases. However, successful homocysteine-lowering treatment by vitamins (B6, B12, and folate) failed to improve these conditions. Long-term increased polyamine intake elevated blood spermine levels and inhibited aging-associated pathologies in mice and humans. Spermine reversed changes (increased dcSAM, decreased DNMT activity, aberrant DNA methylation, and proinflammatory status) induced by the inhibition of ornithine decarboxylase. The relation between polyamine metabolism, one-carbon metabolism, DNA methylation, and the biological mechanism of spermine-induced lifespan extension is discussed.

scholarly journals Selonsertib Alleviates the Progression of Rat Osteoarthritis: An in vitro and in vivo Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiyuan Yan ◽  
Yingchi Zhang ◽  
Gaohong Sheng ◽  
Bowei Ni ◽  
Yifan Xiao ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Cartilage Damage ◽  
Cartilage Degradation ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Therapeutic Effects ◽  
Exact Role

Osteoarthritis (OA) is a prevalent degenerative joint disease. Its development is highly associated with inflammatory response and apoptosis in chondrocytes. Selonsertib (Ser), the inhibitor of Apoptosis Signal-regulated kinase-1 (ASK1), has exhibited multiple therapeutic effects in several diseases. However, the exact role of Ser in OA remains unclear. Herein, we investigated the anti-arthritic effects as well as the potential mechanism of Ser on rat OA. Our results showed that Ser could markedly prevent the IL-1β-induced inflammatory reaction, cartilage degradation and cell apoptosis in rat chondrocytes. Meanwhile, the ASK1/P38/JNK and NFκB pathways were involved in the protective roles of Ser. Furthermore, intra-articular injection of Ser could significantly alleviate the surgery induced cartilage damage in rat OA model. In conclusion, our work provided insights into the therapeutic potential of Ser in OA, indicating that Ser might serve as a new avenue in OA treatment.

scholarly journals Andrographis paniculata Extract Relieves Pain and Inflammation in Monosodium Iodoacetate-Induced Osteoarthritis and Acetic Acid-Induced Writhing in Animal Models

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 873
Author(s):  
Donghun Lee ◽  
Chae Yun Baek ◽  
Ji Hong Hwang ◽  
Mi-Yeon Kim
Keyword(s):  
Acetic Acid ◽  
Weight Bearing ◽  
Cartilage Damage ◽  
Degenerative Joint Disease ◽  
Andrographis Paniculata ◽  
Joint Disease ◽  
Tnf Α ◽  
Monosodium Iodoacetate ◽  
History Of

Osteoarthritis (OA), being the most prominent degenerative joint disease is affecting millions of elderly people worldwide. Although Andrographis paniculata is an ethnic medicine with a long history of being used as analgesic agent, no study using a monosodium iodoacetate (MIA) model has investigated its potential activities against OA. In this study, experimental OA was induced in rats with a knee injection of MIA, which represents the pathological characteristics of OA in humans. A. paniculata extract (APE) substantially reversed the loss of hind limb weight-bearing and the cartilage damage resulted from the OA induction in rats. Additionally, the levels of serum pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α as well as the concentration of matrix metalloproteinases, including MMP-1, MMP-3, MMP-8, and MMP-13 were decreased by APE administration. Acetic acid-induced writhing responses in mice which quantitatively measure pain were significantly reduced by APE. In vitro, APE inhibited the generation of NO and downregulated the expression of IL-1β, IL-6, COX-2, and iNOS in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The above results suggest the potential use APE as a therapeutic agent against OA.

scholarly journals Developmentally Regulated DNA Methylation in Dictyostelium discoideum

2006 ◽  
Vol 5 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Mariko Katoh ◽  
Tomaz Curk ◽  
Qikai Xu ◽  
Blaz Zupan ◽  
Adam Kuspa ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genomic Dna ◽  
Dna Methyltransferase ◽  
Critical Role ◽  
Methylation Status ◽  
Cpg Islands ◽  
Developmentally Regulated ◽  
Unusual Distribution ◽  
Methyltransferase Gene ◽  
Morphological Defects

ABSTRACT Methylation of cytosine residues in DNA plays a critical role in the silencing of gene expression, organization of chromatin structure, and cellular differentiation of eukaryotes. Previous studies failed to detect 5-methylcytosine in Dictyostelium genomic DNA, but the recent sequencing of the Dictyostelium genome revealed a candidate DNA methyltransferase gene (dnmA). The genome sequence also uncovered an unusual distribution of potential methylation sites, CpG islands, throughout the genome. DnmA belongs to the Dnmt2 subfamily and contains all the catalytic motifs necessary for cytosine methyltransferases. Dnmt2 activity is typically weak in Drosophila melanogaster, mouse, and human cells and the gene function in these systems is unknown. We have investigated the methylation status of Dictyostelium genomic DNA with antibodies raised against 5-methylcytosine and detected low levels of the modified nucleotide. We also found that DNA methylation increased during development. We searched the genome for potential methylation sites and found them in retrotransposable elements and in several other genes. Using Southern blot analysis with methylation-sensitive and -insensitive restriction endonucleases, we found that the DIRS retrotransposon and the guaB gene were indeed methylated. We then mutated the dnmA gene and found that DNA methylation was reduced to about 50% of the wild-type level. The mutant cells exhibited morphological defects in late development, indicating that DNA methylation has a regulatory role in Dictyostelium development. Our findings establish a role for a Dnmt2 methyltransferase in eukaryotic development.

scholarly journals The DNA Methylation Landscape of Giant Viruses

2019 ◽  
Author(s):  
Sandra Jeudy ◽  
Sofia Rigou ◽  
Jean-Marie Alempic ◽  
Jean-Michel Claverie ◽  
Chantal Abergel ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Single Molecule ◽  
Defense Mechanism ◽  
Methylation Status ◽  
Purifying Selection ◽  
Dna Methyltransferases ◽  
Epigenetic Mark ◽  
Host Defense Mechanism ◽  
Domains Of Life ◽  
Giant Viruses

AbstractDNA methylation is an important epigenetic mark that contributes to various regulations in all domains of life. Prokaryotes use it through Restriction-Modification (R-M) systems as a host-defense mechanism against viruses. The recently discovered giant viruses are widespread dsDNA viruses infecting eukaryotes with gene contents overlapping the cellular world. While they are predicted to encode DNA methyltransferases (MTases), virtually nothing is known about the DNA methylation status of their genomes. Using single-molecule real-time sequencing we studied the complete methylome of a large spectrum of families: the Marseilleviridae, the Pandoraviruses, the Molliviruses, the Mimiviridae along with their associated virophages and transpoviron, the Pithoviruses and the Cedratviruses (of which we report a new strain). Here we show that DNA methylation is widespread in giant viruses although unevenly distributed. We then identified the corresponding viral MTases, all of which are of bacterial origins and subject to intricate gene transfers between bacteria, viruses and their eukaryotic host. If some viral MTases undergo pseudogenization, most are conserved, functional and under purifying selection, suggesting that they increase the viruses’ fitness. While the Marseilleviridae, Pithoviruses and Cedratviruses DNA MTases catalyze N6-methyl-adenine modifications, some MTases of Molliviruses and Pandoraviruses unexpectedly catalyze the formation of N4-methyl-cytosine modifications. In Marseilleviridae, encoded MTases are paired with cognate restriction endonucleases (REases) forming complete R-M systems. Our data suggest that giant viruses MTases could be involved in different kind of virus-virus interactions during coinfections.

Avulsion Fractures of the Femoral Head: Internal Fixation Using a Ventral Approach to the Hip Joint

1997 ◽  
Vol 10 (01) ◽  
pp. 23-26 ◽  
Author(s):  
P. M. Montavon ◽  
H. F. L’Eplattenier
Keyword(s):  
Femoral Head ◽  
Surgical Technique ◽  
Hip Joint ◽  
Cartilage Damage ◽  
Kirschner Wire ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Joint Surface ◽  
Avulsion Fractures ◽  
Lag Screw

SummaryAvulsion fractures of the femoral head are encountered in conjunction with craniodorsal luxations of the hip joint and cannot be treated conservatively without risking either reluxation of the joint or considerable cartilage damage resulting in degenerative joint disease. Fixation of the fragment is possible by inserting a Kirschner wire and a lag screw from the articular surface, making sure the implants are well countersunk. A ventromedial approach to the hip joint allows good visibility of the joint surface and easy reduction of the fracture without severing the round ligament. The surgical technique described was used on three cases and combines a ventromedial approach to the hip joint with fixation of the fracture with a Kirschner wire and a lag screw inserted from the joint surface, and has the advantages of enabling good reconstruction of the joint surface as well as maintaining postoperative joint stability. Both these factors considerably reduce the development of degenerative joint disease and improve the prognosis for recovery of full limb function.A surgical technique for treatment of avulsion fractures of the femoral head is described. It combines a ventromedial approach to the hip joint with fixation of the fracture with a Kirschner wire and a lag screw inserted from the joint surface.

scholarly journals Aberrant DNA Methylation in Acute Myeloid Leukemia and Its Clinical Implications

2019 ◽  
Vol 20 (18) ◽  
pp. 4576 ◽  
Author(s):  
Xianwen Yang ◽  
Molly Pui Man Wong ◽  
Ray Kit Ng
Keyword(s):  
Dna Methylation ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Epigenetic Modification ◽  
Critical Role ◽  
Genetic Alterations ◽  
Dna Methyltransferases ◽  
Clinical Implications ◽  
Aberrant Dna Methylation ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a heterogeneous disease that is characterized by distinct cytogenetic or genetic abnormalities. Recent discoveries in cancer epigenetics demonstrated a critical role of epigenetic dysregulation in AML pathogenesis. Unlike genetic alterations, the reversible nature of epigenetic modifications is therapeutically attractive in cancer therapy. DNA methylation is an epigenetic modification that regulates gene expression and plays a pivotal role in mammalian development including hematopoiesis. DNA methyltransferases (DNMTs) and Ten-eleven-translocation (TET) dioxygenases are responsible for the dynamics of DNA methylation. Genetic alterations of DNMTs or TETs disrupt normal hematopoiesis and subsequently result in hematological malignancies. Emerging evidence reveals that the dysregulation of DNA methylation is a key event for AML initiation and progression. Importantly, aberrant DNA methylation is regarded as a hallmark of AML, which is heralded as a powerful epigenetic marker in early diagnosis, prognostic prediction, and therapeutic decision-making. In this review, we summarize the current knowledge of DNA methylation in normal hematopoiesis and AML pathogenesis. We also discuss the clinical implications of DNA methylation and the current therapeutic strategies of targeting DNA methylation in AML therapy.

scholarly journals Targeting Cartilage Degradation in Osteoarthritis

2021 ◽  
Vol 14 (2) ◽  
pp. 126
Author(s):  
Oliver McClurg ◽  
Ryan Tinson ◽  
Linda Troeberg
Keyword(s):  
Wnt Pathway ◽  
Cartilage Damage ◽  
Pharmaceutical Research ◽  
Cartilage Degradation ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Disease Modifying Drugs ◽  
Systemic Side Effects ◽  
Socio Economic Impact ◽  
Blocking Antibodies

Osteoarthritis is a common, degenerative joint disease with significant socio-economic impact worldwide. There are currently no disease-modifying drugs available to treat the disease, making this an important area of pharmaceutical research. In this review, we assessed approaches being explored to directly inhibit metalloproteinase-mediated cartilage degradation and to counteract cartilage damage by promoting growth factor-driven repair. Metalloproteinase-blocking antibodies are discussed, along with recent clinical trials on FGF18 and Wnt pathway inhibitors. We also considered dendrimer-based approaches being developed to deliver and retain such therapeutics in the joint environment. These may reduce systemic side effects while improving local half-life and concentration. Development of such targeted anabolic therapies would be of great benefit in the osteoarthritis field.

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