Glutamate Carboxypeptidase II in Aging Rat Prefrontal Cortex Impairs Working Memory Performance

Glutamate carboxypeptidase II (GCPII) expression in brain is increased by inflammation, and reduces NAAG (N-acetyl aspartyl glutamate) stimulation of mGluR3 signaling. Genetic insults in this signaling cascade are increasingly linked to cognitive disorders in humans, where increased GCPII and or decreased NAAG-mGluR3 are associated with impaired prefrontal cortical (PFC) activation and cognitive impairment. As aging is associated with increased inflammation and PFC cognitive deficits, the current study examined GCPII and mGluR3 expression in the aging rat medial PFC, and tested whether GCPII inhibition with 2-(3-mercaptopropyl) pentanedioic acid (2-MPPA) would improve working memory performance. We found that GCPII protein was expressed on astrocytes and some microglia as expected from previous studies, but was also prominently expressed on neurons, and showed increased levels with advancing age. Systemic administration of the GCPII inhibitor, 2-MPPA, improved working memory performance in young and aged rats, and also improved performance after local infusion into the medial PFC. As GCPII inhibitors are well-tolerated, they may provide an important new direction for treatment of cognitive disorders associated with aging and/or inflammation.

Cacao powder supplementation attenuates oxidative stress, cholinergic impairment, and apoptosis in d-galactose-induced aging rat brain

Aging, a critical risk factor of several diseases, including neurodegenerative disorders, affects an ever-growing number of people. Cacao supplementation has been suggested to improve age-related neuronal deficits. Therefore, this study investigated the protective effects of raw cacao powder on oxidative stress-induced aging. Male Sprague–Dawley rats were divided into 4 groups: Control (C), d-galactose-induced aging (G), d-galactose injection with 10% (LC), and 16% (HC) cacao powder mixed diet. d-galactose (300 mg/3 mL/kg) was intraperitoneally injected into all but the control group for 12 weeks. Cacao supplemented diets were provided for 8 weeks. The levels of serum Malondialdehyde (MDA), Advanced Glycation End-products (AGEs), brain and liver MDA, the indicators of the d-galactose induced oxidative stress were significantly decreased in LC and HC but increased in G. The Acetylcholinesterase (AChE) activity of brain showed that the cholinergic impairment was significantly lower in LC, and HC than G. Furthermore, the expression levels of catalase (CAT), phospho-Akt/Akt, and procaspase-3 were significantly increased in LC and HC. In conclusion, cacao consumption attenuated the effects of oxidative stress, cholinergic impairment and apoptosis, indicating its potential in future clinical studies.

PROLONGED LIFESPAN OF AGING RAT AFTER XENOTRANPLANTATION OF HUMAN UMBILICAL CORD MESENCHYMAL STEM CELLS (hUC-MSCs)

Currently, mesenchymal stem cells (MSCs) for implementing regenerative medicine in aging become interest in medical research science, especially in degerative disease and other aging problems. This research was aimed to determine the effectiveness of hUC-MSCs on inhibiting the aging process through the lifetime of the rat and the effect of intravenous administration of hUC-MSCs in phisiologycally aging female rat on the blood analysis. This study was used 40 aged female rats with 29-30 months of age divided into four groups with 10 rats each. The control rat group was given physiological NaCl (0.9%) 0.5 mL, and the treated rat group was given hUC-MSCs 1x107 cells/kg body weight in 0.5 mL NaCl 0.9%, was injected intravenously in caudo lateralis tail vein with stratified frequency; one time injection (SC1), three times injections (SC3) and five times injections (SC5). Perifer blood was collected from retro-ortbital sinus vein 30 days before and after injection of hUC-MSCs for hematology and blood chemistry analysis. Based on the results were obtained, it indicated that hUC-MSCs increased the survival of aging rat were in treatment group, life span of rats was extended up to 40 months compared to the average life of control rat aged up to 34±2 months. The injection of hUC-MSCs 1x107 cells/kg of body weight with one, three and five times injection were affected to blood profiles and blood chemistry with correlation were low. The conclusions are hUC-MSCs extend the lifespan of aging rat and were affect the blood in general but in normal range of aging rat, affect in ALT and creatinin as tissue repair and tolerated by aging rat.