PubMed | Hebei Province Geriatric Hospital, the Bethune International Peace Hospital of PLA and Hebei Medical University
Type: | Journal: Scientific reports | Year: 2016
Histone modifications have been implicated in learning and memory. Our previous transcriptome data showed that expression of sirtuins 6 (SIRT6), a member of Histone deacetylases (HDACs) family in the hippocampal cornu ammonis 1 (CA1) was decreased after contextual fear conditioning. However, the role of SIRT6 in the formation of memory is still elusive. In the present study, we found that contextual fear conditioning inhibited translational expression of SIRT6 in the CA1. Microinfusion of lentiviral vector-expressing SIRT6 into theCA1 region selectively enhanced the expression of SIRT6 and impaired the formation of long-term contextual fear memory without affecting short-term fear memory. The overexpression of SIRT6 in the CA1 had no effect on anxiety-like behaviors or locomotor activity. Also, we also found that SIRT6 overexpression significantly inhibited the expression of insulin-like factor 2 (IGF2) and amounts of proteins and/or phosphoproteins (e.g. Akt, pAkt, mTOR and p-mTOR) related to the IGF2 signal pathway in the CA1. These results demonstrate that the overexpression of SIRT6 in the CA1 impaired the formation of long-term fear memory, and SIRT6 in the CA1 may negatively modulate the formation of contextual fear memory via inhibiting the IGF signaling pathway.
PubMed | The Bethune International Peace Hospital of PLA
Type: Journal Article | Journal: Clinical and investigative medicine. Medecine clinique et experimentale | Year: 2010
Damage to the intestinal barrier often occurs following severe trauma. It has been reported that enteral nutrition with dietary fiber (DF) could mitigate impairment of the intestinal barrier and might therefore be effective in clinical application; however, the conclusions from existing trials are controversial and the nature of the protective mechanism is far from clear. This study investigated the protective mechanism of dietary fiber on intestinal barrier in rats under bilateral closed femur fracture.Twenty-four Sprague-Dawley rats were divided into four groups: normal control without any manipulation, trauma control with normal feeding, DF and dietary fiber-free (NF) groups fed with Nutrison Fibre and Nutrison, respectively. The later two groups were further divided into 1, 4, 7 and 10 days post-trauma groups.The trauma caused body weight decline, promoted bacterial translocation, and decreased immune function. The levels of portal vein endoxin in DF group was significantly lower than in NF group (p=0.013). Levers of both serum TNF-alpha and IL-6 on post-trauma day 10 showed no statistical differences between DF and NF groups. The incidence of bacterial translocation recovered to normal in DF group. Only secreted immunoglobulin a (sIgA) levels in DF group was higher than in NF group (p=0.005).Early enteral nutrition with dietary fiber could alleviate damage to intestinal barrier function and decreased the incidence of bacterial translocation caused by trauma and endotoxemia in rats under extra-abdominal trauma.