The Age of Diabetes and AGE Presented by:Presented by: Ashwini KumarAshwini Kumar Doctoral Research ScholarDoctoral Research Scholar Department of BiotechnologyDepartment of Biotechnology National Institute of Technology RaipurNational Institute of Technology RaipurC.G

Diabetes….. Hyperglycemia Hyperglycemia IDDM (Type 1 Diabetes or T1D) IDDM (Type 1 Diabetes or T1D) NIDDM (Type 2 Diabetes or T2D) NIDDM (Type 2 Diabetes or T2D) Maturity Onset of Diabetes in Youngs (MODY) Maturity Onset of Diabetes in Youngs (MODY) Latent Autoimmune Diabetes in Adults (LADA) or Slow Onset T1D Latent Autoimmune Diabetes in Adults (LADA) or Slow Onset T1D Gestational Diabetes Gestational Diabetes PCOS PCOS 2

Diabetes Outcome Cardiovascular Disorders [CVD] Diabetic Neuropathy Diabetic Nephropathy Diabetic Retinopathy Diabetic Foot Pulmonary Disorders Impaired wound healing Source: Kumar A et al. Type 2 Diabetes Mellitus: The Concerned Complications and Target Organs. Apollo Medicine 2014;11(3):

Type 2 Diabetes Most common form of diabetes. Most common form of diabetes. Obesity, Diet, Environmental factors, Oxidative stress Obesity, Diet, Environmental factors, Oxidative stress Insulin resistance Insulin resistance Hereditary, TCF7L2 gene Hereditary, TCF7L2 gene Polyphagia, Polydipsia and Polyuria Polyphagia, Polydipsia and Polyuria AGEs AGEs 4

Advanced Glycation End Products (AGEs) Major result of uncontrolled hyperglycemia. Major result of uncontrolled hyperglycemia. Glycation = Non-enzymatic addition of a reducing sugar Glycation = Non-enzymatic addition of a reducing sugar Protein glycation = Reaction between free amino group of the protein and a carbonyl group from a reducing sugar to form a freely reversible Schiff base. Protein glycation = Reaction between free amino group of the protein and a carbonyl group from a reducing sugar to form a freely reversible Schiff base. Unstable shiff’s base undergoes Amadori rearrangement to form stable amadori product. Unstable shiff’s base undergoes Amadori rearrangement to form stable amadori product. Affects both intracellular and extracellular proteins. Affects both intracellular and extracellular proteins. 5

Source: Ahmed N. Advanced glycation end products—role in pathology of diabetic complications. Diab Res Clin Pract 2005; 67:3-21 6

Supporting content….. 7

Effects of AGEs Lipid peroxidation Modify proteins AGE-Immune Complex Amino groups of purines in DNA susceptible to glycation Alter enzyme activity Protein fragmentation Alter immunogenecity Decrease ligand binding 8

AGEs Receptors AGEs interact with their cellular receptors. Macrophage Scavenger Receptor Type 1 and 2 Galectin-3 (AGE-R3) RAGE (Receptors for AGE) 9

RAGE Multi-ligand receptor on cell surface 35 kDa protein Immunoglobulin superfamily Macrophages, endothelial cells, smooth muscle, astrocytes Expression increases in diabetes AGE interaction with macrophage RAGE induces oxidative stress. Mammalian, CAMs 10 Neeper M et al. Cloning and Expression of a Cell Surface Receptor for Advanced Glycosylation End Products of Protein. J Biol Chem 1992; 267(21): Sessa L et al. The Receptor for Advanced Glycation End-Products (RAGE) Is Only Present in Mammals, and Belongs to a Family of Cell Adhesion Molecules (CAMs). Plos One 2014; 9(1): e86903.

Effects of AGE + RAGE 11

AGEs and Inflammations Expression increases in inflammation; increased expression leads to inflammation. Found on immune cells like Macrophages, Neutrophills, T & B cells, Dendritic cells. Triggered by many ligands involved in inflammation. Expression in endothelial cells; leukocyte adhesion. Activation of NF-kB 12

AGEs and CVDs Most frequent effect of diabetes mellitus Targets vasculature and myocardium. Atherosclerosis Thickening of tunica intima; arterial occlusion Increased oxidation and glycation of LDL  Increased plasminogen activator inhibitor-1  Decreased TPA Glycated HDL – Less clearance of oxidized LDL, less ability to prevent monocyte-endothelial adhesion. Arteriosclerosis  Collagen damage  ECM Damage 13 AGEs LDL Glycoxidized LDL Atherosclerosis Thrombosis Embolism Arteriosclerosis Hypertension Vascular Damage Decreased NO

AGEs and Neuro-ailments Peripheral Neuropathy  Sensory & Motor Nerves  Nerve fiber degeneration  Endoneurial microangiopathy  Microvascular injury  Reduced myelination  Axonal cytoskeleton glycated  AGEs in every component of nerve tissue  AGEs induced inflammation 14

Contd….. Alzheimer’s disease  β -amyloid (A β ) deposition as extra-neural plaques  A β as ligand for neural and microglial RAGE  Cell death in RAGE expressing cells  AGE accumulation in AD  RAGE activation; BACE1 activity increases  Mitochondrial dysfunction in neurons  RAGE Transports A β across BBB  AGE + RAGE = Decreased cerebral blood flow. 15

AGE and Diabetic Retinopathy Major cause of blindness in diabetic population. Loss of pericytes, micro-aneurysm, vessel thickening, increased “leakyness”…..leading to macular oedema and macular damage Higher AGE (NCML) in retina and serum of DR patients. Muller cells are greatly damaged. RAGE expression increased in diabetic muller cells. AGE modified albumin was higher in retinal capillary of IDDM patients. AGE destroys Pigment Epithelium Derived Factor (PEDF) which protects against DR. AGE + RAGE = Retinal neuron death. 16

Sources of External - AGEs Obtained through food. Longer or intense heating or cooking Food with high carbohydrate, fats and (carb + protein) High food AGE consumption; greater serum AGE Milk tea, bakery, potato, white rice, meat products 17

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