Posts Tagged: diet

Environmental Determinants of Cardiovascular Disease

Environmental Determinants of Cardiovascular Disease

Aruni Bhatnagar

The effect of sunlight on cardiovascular health. The visible range of sunlight regulates the master clock located in the pacemaker neurons of the suprachiasmatic nucleus, which sets the intrinsic 24-h cycle and synchronizes the light-insensitive peripheral clocks to coordinate cycles of waking, sleeping, and feeding. The UVB radiation converts 7-dehydrocholesterol in the epidermis to pre–vitamin D3, which undergoes thermal isomerization to vitamin D. Vitamin D3 formed in the skin appear in the circulation and is then transported to the liver where it is converted to 25(OH)D3. In kidney, 25(OH) D3 undergoes hydroxylation to form biologically active 1,25(OH)2D. The UVA radiation induces photodegradation of nitrosothiols, such as S-nitrosylglutathione, which leads to the generation of NO, an important regulator of blood pressure. (Illustration credit: Ben Smith.) [Powerpoint File]

Epigenetics and Metabolism

Epigenetics and Metabolism

Samuel T. Keating, Assam El-Osta

The chromatin code. Gene function is primarily regulated by chromatin accessibility. Cytosine bases covalently modified by addition of methyl groups are recognized by methyl-binding proteins that associate with chromatin remodeling factors to establish transcriptionally incompetent chromatin architectures. The nucleosome is comprised of ≈147 bp of DNA encircling an octamer of 2 copies of each of the 4 core histone proteins H2A, H2B, H3, and H4. Post-translational modification (PTM) of nucleosomal histones further regulates transition between active euchromatin and silent heterochromatin. Shown here is a summary of acetyl (green) and methyl (red) modifications of specific arginine (R) and lysine (K) residues on N-terminal tails of the heavily modified H3 and H4 histones. Adding a greater level of complexity, arginine residues can be mono- and di-methylated, and lysines mono-, di-, or trimethylated. CR indicates chromatin remodelling; and ME, methylation. [Powerpoint File]

Epigenetics and Metabolism

Epigenetics and Metabolism

Samuel T. Keating, Assam El-Osta

Genome-wide distribution of histone methylation. Graphical representation of the aorta showing the endothelial cell layer and flow of CD14+ monocytes and blood cells. The circos plot shows the genomic distribution of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) on human autosomes of vascular endothelial cells and primary CD14+ monocytes. Genome-wide maps are derived from chromatin immunoprecipitation combined with sequencing (ChIP-seq) data accessed from the ENCODE project using the UCSC browser. H3K4me3 and H3K27me3 peaks were considered overlapping using a minimum of 5% coverage. The percentage of genome coverage for each peak represents the sum of the total length of all peaks divided by the total number of base pairs in the genome. Alignability scores used were derived from ENCODE (UCSC assession: wgEncodeEH000318). Base pairs with an alignability score of ≥1 were considered mappable. Histone methylation unique to vascular endothelial cells are shown in blue and those unique to monocytes are shown in orange. Regions of histone methylation overlap in vascular endothelial and monocytes (minimum 5% overlap) are shown in yellow. [Powerpoint File]

Lifestyle Effects on Hematopoiesis and Atherosclerosis

Lifestyle Effects on Hematopoiesis and Atherosclerosis

Matthias Nahrendorf, Filip K. Swirski

The hematopoietic niche. The cartoon depicts components that indirectly regulate the activity of hematopoietic stem cells. Upper, left, An original microscopy image of the mouse bone marrow, illustrating sympathetic nerve fibers traveling along bone marrow vessels. Lower, left, Obtained in the bone marrow of a mouse after ischemic stroke and shows replicating hematopoietic progenitor cells (arrows). Both images are adapted from Courties et al83 with permission. CXCL indicates C-x-c chemokine ligand; GM-CSF, granulocyte macrophage colony-stimulating factor; HSC, hematopoietic stem cell; MSC, mesenchymal stem cell; VCAM, vascular cell adhesion protein; and VE, vascular endothelial. [Powerpoint File]

Lifestyle Effects on Hematopoiesis and Atherosclerosis

Lifestyle Effects on Hematopoiesis and Atherosclerosis

Matthias Nahrendorf, Filip K. Swirski

The hematopoietic tree on the move. The cartoon illustrates the hypothetical contribution of lifestyle factors toward shifting the macrophage supply peripherally and associating with atherosclerosis progression and complication. HSPC indicates hematopoietic stem and progenitor cell. [Powerpoint File]