062. DEVELOPMENTAL ORIGINS OF TYPE 2 DIABETES: EPIGENETIC MECHANISMS IN BETA CELL FAILURE

2009 ◽  
Vol 21 (9) ◽  
pp. 17
Author(s):  
R. Simmons
Keyword(s):  
Proximal Promoter ◽  
Histone Acetyl Transferase ◽  
Short Treatment ◽  
Homeobox Transcription Factor ◽  
Pancreatic B Cells ◽  
Glucagon Like Peptide 1 ◽  
Long Acting ◽  
And Function ◽  
Pdx1 Expression ◽  
H3 Acetylation

The abnormal intrauterine milieu of intrauterine growth retardation (IUGR) permanently alters gene expression and function of pancreatic b -cells leading to the development of diabetes in adulthood. Expression of the pancreatic homeobox transcription factor Pdx1 is permanently reduced in IUGR and epigenetic modifications are responsible for this decrease. Exendin-4 (Ex-4), a long-acting glucagon-like peptide 1 (GLP-1) analog, given on days 1-6 of life increases Pdx1 expression and prevents the development of diabetes in the IUGR rat. Here we show that Ex-4 increases USF-1 and PCAF association at the proximal promoter of Pdx1, thereby increasing histone acetyl transferase (HAT) activity leading to a permanent increase in histone H3 acetylation and H3K4 methylation. Normalization of these histone modifications precludes DNA methylation thereby preventing silencing of Pdx1 in islets of IUGR animals. These studies demonstrate a novel mechanism whereby a short treatment course of Ex-4 in the newborn period prevents diabetes in adulthood by restoring Pdx1 promoter chromatin structure thus preserving Pdx1 transcription.

scholarly journals Trichostatin A Promotes the Generation and Suppressive Functions of Regulatory T Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Cristian Doñas ◽  
Macarena Fritz ◽  
Valeria Manríquez ◽  
Gabriela Tejón ◽  
María Rosa Bono ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Trichostatin A ◽  
Gene Promoter ◽  
Treg Cells ◽  
Specific Subset ◽  
Global Increase ◽  
And Function ◽  
H3 Acetylation

Regulatory T cells are a specific subset of lymphocytes that suppress immune responses and play a crucial role in the maintenance of self-tolerance. They can be generated in the thymus as well as in the periphery through differentiation of naïve CD4+T cells. The forkhead box P3 transcription factor (Foxp3) is a crucial molecule regulating the generation and function of Tregs. Here we show that thefoxp3gene promoter becomes hyperacetylated inin vitrodifferentiated Tregs compared to naïve CD4+T cells. We also show that the histone deacetylase inhibitor TSA stimulated thein vitrodifferentiation of naïve CD4+T cells into Tregs and that this induction was accompanied by a global increase in histone H3 acetylation. Importantly, we also demonstrated that Tregs generated in the presence of TSA have phenotypical and functional differences from the Tregs generated in the absence of TSA. Thus, TSA-generated Tregs showed increased suppressive activities, which could potentially be explained by a mechanism involving the ectonucleotidases CD39 and CD73. Our data show that TSA could potentially be used to enhance the differentiation and suppressive function of CD4+Foxp3+Treg cells.

scholarly journals Oleoylethanolamide modulates glucagon-like peptide-1 receptor agonist signaling and enhances exendin-4-mediated weight loss in obese mice

2018 ◽  
Vol 315 (4) ◽  
pp. R595-R608 ◽  
Author(s):  
Jacob D. Brown ◽  
Danielle McAnally ◽  
Jennifer E. Ayala ◽  
Melissa A. Burmeister ◽  
Camilo Morfa ◽  
...  
Keyword(s):  
Weight Loss ◽  
Energy Expenditure ◽  
Receptor Agonist ◽  
Day Treatment ◽  
Mtor Pathway ◽  
Obese Mice ◽  
Promote Weight Loss ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Long Acting

Long-acting glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists (GLP-1RA), such as exendin-4 (Ex4), promote weight loss. On the basis of a newly discovered interaction between GLP-1 and oleoylethanolamide (OEA), we tested whether OEA enhances GLP-1RA-mediated anorectic signaling and weight loss. We analyzed the effect of GLP-1+OEA and Ex4+OEA on canonical GLP-1R signaling and other proteins/pathways that contribute to the hypophagic action of GLP-1RA (AMPK, Akt, mTOR, and glycolysis). We demonstrate that OEA enhances canonical GLP-1R signaling when combined with GLP-1 but not with Ex4. GLP-1 and Ex4 promote phosphorylation of mTOR pathway components, but OEA does not enhance this effect. OEA synergistically enhanced GLP-1- and Ex4-stimulated glycolysis but did not augment the hypophagic action of GLP-1 or Ex4 in lean or diet-induced obese (DIO) mice. However, the combination of Ex4+OEA promoted greater weight loss in DIO mice than Ex4 or OEA alone during a 7-day treatment. This was due in part to transient hypophagia and increased energy expenditure, phenotypes also observed in Ex4-treated DIO mice. Thus, OEA augments specific GLP-1RA-stimulated signaling but appears to work in parallel with Ex4 to promote weight loss in DIO mice. Elucidating cooperative mechanisms underlying Ex4+OEA-mediated weight loss could, therefore, be leveraged toward more effective obesity therapies.

scholarly journals Identification of expression and function of the glucagon-like peptide-1 receptor in colonic smooth muscle

Peptides ◽  
2019 ◽  
Vol 112 ◽  
pp. 48-55 ◽  
Author(s):  
Alexander T. May ◽  
Molly S. Crowe ◽  
Bryan A. Blakeney ◽  
Sunila Mahavadi ◽  
Hongxia Wang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
And Function

scholarly journals Do DLX3 and CD271 Protect Human Keratinocytes from Squamous Tumor Development?

2019 ◽  
Vol 20 (14) ◽  
pp. 3541 ◽  
Author(s):  
Elisabetta Palazzo ◽  
Alessandra Marconi ◽  
Carlo Pincelli ◽  
Maria I. Morasso
Keyword(s):  
Tumor Development ◽  
Human Keratinocytes ◽  
Epidermal Differentiation ◽  
Trk Receptor ◽  
Neurotrophin 3 ◽  
Homeobox Transcription Factor ◽  
Epidermal Homeostasis ◽  
Transcription Regulators ◽  
And Function ◽  
Normal Epidermis

Well-regulated epidermal homeostasis depends on the function of different classes of factors, such as transcription regulators and receptors. Alterations in this homeostatic balance may lead to the development of cutaneous squamous tumorigenesis. The homeobox transcription factor DLX3 is determinant for a p53-dependent regulation of epidermal differentiation and modulates skin carcinogenesis. The maintenance of skin homeostasis also involves the action of neurotrophins (NTs) and their receptors, Trk and CD271. While Trk receptor overexpression is a hallmark of cancer, there are conflicting data on CD271 expression and function in cutaneous SCC (cSCC). Previous studies have reported NT receptors expression in head and neck SSC (HNSCC). We show that CD271 is expressed at low levels in primary cSCC cells and the number of CD271+ cells correlates with cell cohesion in SCC spheroids. In normal epidermis, CD271 is expressed in proliferative progenitor cells and DLX3 in terminally differentiated keratinocytes. Brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) increase DLX3 expression. In the absence of a functional BDNF receptor TrkB in keratinocytes, we hypothesize that the BDNF-dependent DLX3 response could be mediated via CD271. Altogether, our results support a putative CD271-DLX3 connection in keratinocytes, which might be crucial to preventing squamous skin cancer.

scholarly journals The experience with the clinical application of liralgutide (victosa), the first analog of human glucagon-like peptide-1 in the patients with type 2 diabetes mellitus - expanding the range of possibilities

2012 ◽  
Vol 58 (3) ◽  
pp. 51-55
Author(s):  
E N Ostroukhova ◽  
O K Khmel'nitskiĭ ◽  
E I Krasil'nikova ◽  
K S Davidenko
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Body Weight ◽  
Adverse Reactions ◽  
Brand Name ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Long Acting

This paper reports the results of the treatment of 71 patients presenting with type 2 diabetes mellitus using liraglutide, a long-acting analog of glucagon-like peptide-1 (GLP-1) marketed under the brand name Victoza. Practically all the patients experienced either improvement or normalization of the parameters of carbohydrate metabolism in conjunction with a reduction of their body weight and arterial pressure. There were no severe hypoglycemic episodes and other adverse reactions to the therapy. It is recommended that Victoza should be more widely used for the treatment of the patients with type 2 diabetes mellitus.

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