title: Long-term dietary restriction differentially affects the expression of BDNF and its receptors in the cortex and hippocampus of middle-aged and aged male rats.
abstract: Dietary restriction (DR) exerts significant beneficial effects in terms of aging and age-related diseases in many organisms including humans. The present study aimed to examine the influence of long-term DR on the BDNF system at the transcriptional and translational levels in the cortex and hippocampus of middle-aged (12-month-old) and aged (24-month-old) male Wistar rats. The obtained results revealed that the DR upregulated the expression of exon-specific BDNF transcripts in both regions, followed by elevated levels of mBDNF only in the cortex in middle-aged animals. In aged animals, DR modulated BDNF protein levels by increasing proBDNF and by declining mBDNF levels. Additionally, elevated levels of the full-length TrkB accompanied by a decreased level of the less-glycosylated TrkB protein were observed in middle-aged rats following DR, while in aged rats, DR amplified only the expression of the less-glycosylated form of TrkB. The levels of phosphorylated TrkB(Y816) were stable during aging regardless of feeding. Reduced levels of p75(NTR) were detected in both regions of middle-aged DR-fed animals, while a significant increase was measured in the cortex of aged DR-fed rats. These findings shed additional light on DR as a modulator of BDNF system revealing its disparate effects in middle-aged and aged animals. Given the importance of the proBDNF/BDNF circuit-level expression in different brain functions and various aspects of behavior, it is necessary to further elucidate the optimal duration of the applied dietary regimen with regard to the animal age in order to achieve its most favorable effects.
authors.affiliation: Laboratory of Molecular Neurobiology, Department of Neurobiology, Institute for Biological Research ''Sinisa Stankovic'', University of Belgrade, Bul D.Stefana 142, 11060, Belgrade, Serbia.
authors.forename: Kosara
authors.initials: K
authors.lastname: Smiljanic
authors.forename: Vesna
authors.initials: V
authors.lastname: Pesic
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Mladenovic Djordjevic
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Pavkovic
authors.forename: Marjana
authors.initials: M
authors.lastname: Brkic
authors.forename: Sabera
authors.initials: S
authors.lastname: Ruzdijic
authors.forename: Selma
authors.initials: S
authors.lastname: Kanazir
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D031204:Caloric Restriction; D002540:Cerebral Cortex / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger; D020800:Receptor, Nerve Growth Factor; D011505:Protein-Tyrosine Kinases; D020813:Receptor, trkB