Introduction. Alzheimer’s disease (AD), the most common neurodegenerative disorder, is characterized by the accumulation of amyloid-β (Aβ) peptide and hyperphosphorylated tau protein. Accumulating evidence has revealed that the slow progressive deterioration of AD is associated with oxidative stress and chronic inflammation in the brain. Nuclear factor erythroid 2- (NF-E2-) related factor 2 (Nrf2), which acts through the Nrf2/ARE pathway, is a key regulator of the antioxidant and anti-inflammatory response. Although recent data show a link between Nrf2 and AD-related cognitive decline, the mechanism is still unknown. Thus, we explored how Nrf2 protects brain cells against the oxidative stress and inflammation of AD in a mouse model of AD (APP/PS1 transgenic (AT) mice) with genetic removal of Nrf2. Methods. The spatial learning and memory abilities of 12-month-old transgenic mice were evaluated using a Morris water maze test. Hippocampal levels of Nrf2, Aβ, and p-tauS404 and of astrocytes and microglia were determined by immunostaining. Inflammatory cytokines were determined by ELISA and quantitative real-time polymerase chain reaction (qRT-PCR). Oxidative stress was measured by 8-hydroxydeoxyguanosine immunohistochemistry, and the antioxidant response was determined by qRT-PCR. Results. The spatial learning and memory abilities of AT mice were impaired after Nrf2 deletion. Aβ and p-tauS404 accumulation was increased in the hippocampus of AT/Nrf2-KO mice. Astroglial and microglial activation was exacerbated, followed by upregulation of the proinflammatory cytokines IL-1β, IL-6, and TNF-α. Conclusion. Our present results show that Nrf2 deficiency aggravates AD-like pathology in AT mice. This phenotype was associated with increased levels of oxidative and proinflammatory markers, which suggests that the Nrf2 pathway may be a promising therapeutic target for AD.
Objective: The current meta-analysis evaluated the association between vitamin B 12 intake and blood vitamin B 12 level and colorectal cancer (CRC) risk. Design: The PubMed and EMBASE databases were searched. A dose-response analysis was performed with generalized least squares regression, with the relative risk (RR) and 95 % CI as effect values. Setting: The meta-analysis included seventeen studies. Subjects: A total of 10 601 patients. Results: The non-linear dose-response relationship between total vitamin B 12 intake and CRC risk was insignificant (P = 0·690), but the relationship between dietary vitamin B 12 intake and CRC risk was significant (P < 0·001). Every 4·5 μg/d increment in total and dietary vitamin B 12 intake was inversely associated with CRC risk (total intake: RR = 0·963; 95 % CI 0·928, 0·999; dietary intake: RR = 0·914; 95 % CI 0·856, 0·977). The inverse association between vitamin B 12 intake and CRC risk was also significant when vitamin B 12 intake was over a dosage threshold, enhancing the non-linear relationship. The non-linear dose-response relationship between blood vitamin B 12 level and CRC risk was insignificant (P = 0·219). There was an insignificant association between every 150 pmol/l increment in blood vitamin B 12 level and CRC risk (RR = 1·023; 95 % CI 0·881, 1·187). Conclusions: Our meta-analysis indicates that evidence supports the use of vitamin B 12 for cancer prevention, especially among populations with high-dose vitamin B 12 intake, and that the association between CRC risk and total vitamin B 12 intake is stronger than between CRC risk and dietary vitamin B 12 intake only.
The study investigated the expression of monoacylglycerol lipase (MGL) during the skin-incised wound healing in mice and applicability of the time-dependent expression of MGL to wound age determination by immunofluorescent staining, Western blotting, and real-time PCR. Furthermore, cell types were identified by double immunofluorescence. A total of 45 BALB/c male mice were used in this study. After a 1.5-cm-long incision in the central dorsum skin, mice were killed at intervals ranging from 6 h to 14 days, followed by the sampling of wound margin. In the control, there was a low-level expression of MGL in the epidermis, hair follicles, and glandulae sebaceae. In the injured skin, MGL immunoreactivity was mainly detected in the neutrophils, macrophages, and myofibroblasts. Morphometrically, the average ratios of MGL-positive cells were more than 50% at 5 and 7 days post-wounding, whereas it was <50% at the other posttraumatic intervals. By Western blotting analysis, the average ratio of MGL protein expression was highest at 5 days after injury, which had a ratio of >2.30. Similarly, the relative quantity of MGL mRNA expression maximized at posttraumatic 5 days in comparison with control as detected by real-time PCR, with an average ratio of >2.54. In conclusion, MGL expression is detected in neutrophils, macrophages, and myofibroblasts and significantly up-regulated, suggesting that it may play roles in response to inflammation during skin-incised wound healing. From the viewpoint of forensic pathology, MGL detection is applicable to skin wound age determination.
Background: Neuroinflammation is recognized as one of the main pathological mechanisms of secondary injury caused by traumatic brain injury (TBI). It has been reported that interleukin (IL)-18 is expressed in glial cells and involved in the regulation of neuroinflammation. Further studies have revealed that IL-18 expression is upregulated and may contribute to pathogenesis in the later phases of TBI; however, the mechanism underlying the effect of IL-18 on TBI remains unclear. Our present study assessed the roles of IL-18 in inflammatory and neurodegenerative pathology in mice subjected to TBI.Methods: A controlled cortical impact (CCI) injury model was conducted to mimic TBI, and brains were collected at 3 and 7 days post TBI (dpi). The levels of IL-18 were detected by qRT-PCR and immunofluorescence staining. In addition, neurological severity score (NSS) was used to assess neurological deficits after TBI. Furthermore, neuronal cell death, glial activation, and inflammatory cytokine and chemokine secretion were evaluated in wild-type ( WT ) and Il18-knockout ( Il18 -KO) mice to explore the role of IL-18 in TBI.Results: IL-18 levels were upregulated post TBI, accompanied by reactive glial activation. Il-18 deficiency significantly ameliorated glial activation and improved neuronal cell death and neurological deficits. In addition, Il-18 deficiency reduced the TBI-induced M1-like microglia frequency. Interestingly, the levels of all pro- and anti-inflammatory cytokines, including IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p40, IL-12p70, IL-13, IL17A, G-CSF, GM-CSF, IFN-γ, and TNF-α, were downregulated in Il18 -KO mice. The deletion of Il-18 attenuated the levels of most chemokines induced by TBI, including CCL2, CCL3, CCL4, CCL5, CCL7, CCL12, CCL20, CXCL1, CXCL2, CXCL10, CXCL12, CXCL13, and CXCL16.Conclusions: These data demonstrated that IL-18 is involved in TBI induced neuroinflammation, which suggests that IL-18 is important for the development of secondary injury induced by TBI.
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