Regulation of CREB Phosphorylation in Nucleus Accumbens after Relief Conditioning

The Pathological Effects of Circulating Hydrophobic Bile Acids in Alzheimer's Disease

Recent clinical studies have revealed that the serum levels of toxic hydrophobic bile acids (deoxy cholic acid, lithocholic acid [LCA], and glycoursodeoxycholic acid) are significantly higher in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) when compared to control subjects. The elevated serum bile acids may be the result of hepatic peroxisomal dysfunction. Circulating hydrophobic bile acids are able to disrupt the blood-brain barrier and promote the formation of amyloid-β plaques through enhancing the oxidation of docosahexaenoic acid. Hydrophobic bile acid may find their ways into the neurons via the apical sodium-dependent bile acid transporter. It has been shown that hydrophobic bile acids impose their pathological effects by activating farnesoid X receptor and suppressing bile acid synthesis in the brain, blocking NMDA receptors, lowering brain oxysterol levels, and interfering with 17β-estradiol actions such as LCA by binding to E2 receptors (molecular modelling data exclusive to this paper). Hydrophobic bile acids may interfere with the sonic hedgehog signaling through alteration of cell membrane rafts and reducing brain 24(S)-hydroxycholesterol. This article will 1) analyze the pathological roles of circulating hydrophobic bile acids in the brain, 2) propose therapeutic approaches, and 3) conclude that consideration be given to reducing/monitoring toxic bile acid levels in patients with AD or aMCI, prior/in combination with other treatments.

Mechanism of Stat1 in the neuronal Ca2+ overload after intracerebral hemorrhage via the H3K27ac/Trpm7 axis

Intracerebral hemorrhage (ICH) is classified as a subtype of stroke and Calcium (Ca²⁺) overload is a catalyst for ICH. This study explored the mechanisms of Stat1 (signal transducer and activator of transcription 1) in the neuronal Ca²⁺ overload after ICH. ICH mouse models and in vitro cell models were established. Stat1 and transient receptor potential melastatin 7 (Trpm7) were detected up-regulated in ICH models. Afterwards, the mice were infected with the lentivirus containing sh-Stat1, and HT22 cells were treated with si-Stat1 and the lentivirus containing pcDNA3.1-Trpm7. The neurologic functional impairment, histopathological damage, and Nissl body in mice were all measured. HT22 cell viability and apoptosis were identified. The levels of Ca²⁺, Trpm7 mRNA, H3K27 acetylation (H3K27ac), CaMKII-α, and p-Stat1 protein in the tissues and cells were determined. We found that silencing Stat1 alleviated ICH damage and repressed the neuronal Ca²⁺ overload after ICH. H3K27ac enrichment in the Trpm7 promoter region was examined and we found that p-Stat1 accelerated Trpm7 transcription via promoting H3K27ac in the Trpm7 promoter region. Besides, Trpm7 overexpression increased Ca²⁺ overload and aggravated ICH. Overall, p-Stat1 promoted Trpm7 transcription and further aggravated the Ca²⁺ overload after ICH.