Effects of Maillard reaction and its product AGEs on aging and age-related diseases

Maillard reaction(MR)is a non-enzymatic browning reaction commonly seen in food processing,which occurs between reducing sugars and compounds with amino groups.Despite certain advantages based on Maillard reaction products(MRPs)found in some food for health and storage application have appeared,however,the MR occurring in human physiological environment can produce advanced glycation end products(AGEs)by non-enzymatic modification of macromolecules such as proteins,lipids and nucleic acid,which could change the structure and functional activity of the molecules themselves.In this review,we take AGEs as our main object,on the one hand,discuss physiologic aging,that is,age-dependent covalent cross-linking and modification of proteins such as collagen that occur in eyes and skin containing connective tissue.On the other hand,pathological aging associated with autoimmune and inflammatory diseases,neurodegenerative diseases,diabetes and diabetic nephropathy,cardiovascular diseases and bone degenerative diseases have been mainly proposed.Based on the series of adverse effects of accelerated aging and disease pathologies caused by MRPs,the possible harm caused by some MR can be slowed down or inhibited by artificial drug intervention,dietary pattern and lifestyle control.It also stimulates people's curiosity to continue to explore the potential link between the MR and human aging and health,which should be paid more attention to for the development of life sciences.

Does endurance training improve red blood cell aging and hemorheology in moderate-trained healthy individuals?

Objective:To examine the impact of a 6-week endurance training on red blood cell(RBC)aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.Methods:A total of 31 participants(17 females and 14 males)performed a 6-week moderate training protocol(three 1-h running sessions per week at 70%of maximal heart rate).Blood was sampled before and after the training.RBCs from each participant were fractioned according to density and age into 4 RBC subfractions.Subfractions were examined for changes of RBC properties,including aging distribution,RBC deformability,RBC microparticles,and phosphatidylserine concentrations.RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.Results:Aerobic performance,peak oxygen consumption,ventilatory thresholds,velocity at the aerobic-anaerobic threshold,and lactate at exhaustion improved after training.The relative amount of both young RBCs and old RBCs increased,and the amount of the main RBC fraction decreased.Phosphatidylserine externalization and RBC-derived microparticles decreased.Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs(p<0.001).Nitrite decreased in total(p=0.001),young(p<0.001),main(p<0.001),and old(p=0.020)aged RBCs and in plasma(p=0.002),but not in very old RBCs.Conclusion:These results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced,which might support oxygen supply in the microcirculation.

Immunosenescence and age-related viral diseases

Immunosenescence is described as a decline in the normal functioning of the immune system associated with physiologic ageing.Immunosenescence contributes to reduced efficacy to vaccination and increased susceptibility to infectious diseases in the elderly.Extensive studies of laboratory animal models of ageing or donor lymphocyte analysis have identified changes in immunity caused by the ageing process.Most of these studies have identified phenotypic and functional changes in innate and adaptive immunity.However,it is unclear which of these defects are critical for impaired immune defense against infection.This review describes the changes that occur in innate and adaptive immunity with ageing and some age-related viral diseases where defects in a key component of immunity contribute to the high mortality rate in mouse models of ageing.