Amyloid-β peptides (Aβ) exist in several forms and are known as key modulators of Alzheimer’s disease (AD). Fibrillary Aβ (fAβ) has been found to disrupt the blood-brain barrier (BBB) by triggering and promoting inflammation. In this study, luteolin, a naturally occurring flavonoid that has shown beneficial properties in the central nervous system, was evaluated as a potential agent to preserve barrier function and inhibit inflammatory responses at the BBB that was injured by fAβ1–40. We established an in vitro BBB model by co-culturing human brain microvascular endothelial cells (hBMECs) and human astrocytes (hAs) under fAβ1–40-damaged conditions and investigated the effect of luteolin by analyzing cellular toxicity, barrier function, cytokine production and inflammation-related intracellular signaling pathways. Our results demonstrated that, in cells injured by fAβ1–40, luteolin increased cell viability of hBMECs and hAs. The cytoprotection of the co-culture against the damage induced by fAβ1–40 was also increased at both the apical and basolateral sides. Luteolin protected the barrier function by preserving transendothelial electrical resistance and relieving aggravated permeability in the human BBB model after being exposed to fAβ1–40. Moreover, in both the apical and basolateral sides of the co-culture, luteolin reduced fAβ1–40-induced inflammatory mediator and cytokine production, including cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin 1 β (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8), however it did not show sufficient effects on scavenging intracellular reactive oxygen species (ROS) in hBMECs and hAs. The mechanism of BBB protection against fAβ1–40-induced injury may be related to the regulation of inflammatory signal transduction, which involves inhibition of p38 mitogen-activated protein kinase (MAPK) activation, downregulation of phosphorylated inhibitory κB kinase (phosphor-IKK) levels, relief of inhibitory κB α (IκBα) degradation, blockage of nuclear factor κB (NF-κB) p65 nuclear translocation, and reduction of the release of inflammatory cytokines. Moreover, the employment of p38 MAPK and NF-κB inhibitors reversed luteolin-mediated barrier function and cytokine release. Taken together, luteolin may serve as a potential therapeutic agent for BBB protection by inhibiting inflammation following fAβ1–40-induced injury.

Alzheimer’s disease (AD) is characterized by two landmark pathologies, the overproduction of amyloid-beta peptides (Aβ), predominated by the β-amyloid protein precursor cleaving enzyme 1 (BACE1), and hyperphosphorylation of the microtubule protein, tau, because of an imbalance in a kinase/phosphatase system that involves the activation of the protein kinase A (PKA). Current evidence indicates that brain microRNAs participate in multiple aspects of AD pathology. Here, the role and underlying molecular mechanisms of microRNA-200a-3p (miR-200a-3p) in mediating neuroprotection against AD-related deficits were investigated. The expression of miR-200a-3p was measured in the hippocampus of APP/PS1 and SAMP8 mice and in an AD cell model in vitro , as well as in blood plasma extracted from AD patients. The targets of miR-200a-3p were determined using bioinformatics and dual-luciferase assay analyses. In addition, cell apoptosis was detected using flow cytometry, and related protein levels were measured using Western blot and enzyme-linked immunosorbent assay (ELISA) techniques. miR-200a-3p was confirmed to be depressed in microarray miRNA profile analysis in vitro and in vivo , suggesting that miR-200a-3p is a potential biomarker of AD. Subsequently, miR-200a-3p was demonstrated to inhibit cell apoptosis accompanied by the inactivation of the Bax/caspase-3 axis and downregulation of Aβ 1-42 and tau phosphorylation levels in vitro . Further mechanistic studies revealed that miR-200a-3p reduced the production of Aβ 1-42 and decreased hyperphosphorylation of tau by regulating the protein translocation of BACE1 and the protein kinase cAMP-activated catalytic subunit beta ( PRKACB ) associated with the three prime untranslated regions, respectively. Importantly, the function of miR-200a-3p was reversed by overexpression of BACE1 or PRKACB in cultured cells. This resulted in an elevation in cell apoptosis and increases in Aβ 1-42 and tau hyperphosphorylation levels, involving the epitopes threonine 205 and serine 202, 214, 396, and 356, the favorable phosphorylated sites of PKA. In conclusion, our study suggests that miR-200a-3p is implicated in the pathology of AD, exerting neuroprotective effects against Aβ-induced toxicity by two possible mechanisms: one involving the inhibition of Aβ overproduction via suppression of the expression of BACE1 and synergistically decreasing the hyperphosphorylation of tau via attenuation of the expression of PKA.

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Pseudocontact shifts (PCS) generated by paramagnetic metal ions present valuable long-range information in the study of protein structural biology by nuclear magnetic resonance (NMR) spectroscopy. Faithful interpretation of PCSs, however, requires complete immobilization of the metal ion relative to the protein, which is difficult to achieve with synthetic metal tags. We show that two histidine residues in sequential turns of an α-helix provide a binding site for a Co ion, which positions the metal ion in a uniquely well-defined and predictable location. Exchange between the bound and free cobalt is slow on the timescale defined by chemical shifts, but the NMR resonance assignments are nonetheless readily transferred from the diamagnetic to the paramagnetic NMR spectrum by an I S -exchange experiment. The double-histidine-Co motif offers a straightforward, inexpensive, and convenient way of generating precision PCSs in proteins.

The introduction of metal−organic framework materials into photocatalysts is considered to be an effective strategy for improving the transfer and separation efficiency of photogenerated electron−hole pairs. In the present study, we demonstrate the delicate construction of NH 2 -UiO-66/ZnIn 2 S 4 (NU66/ZIS) composites as bifunctional photocatalysts with the degradation efficiency of malachite green (98%) and the hydrogen evolution rate of a 10% NU66/ZIS composite reaching up to 2199 μmol h −1 g −1 . The characterization of unique ZIS/NU66 shows that it can efficiently facilitate the separation and transfer of light-induced charges and exposed rich active sites for photocatalyst redox reaction. Moreover, the results of vitro cytotoxicity assay suggest that NU66/ZIS composites are potential safety photocatalysts to the environment and human beings. Furthermore, the DFT calculation indicates that the Zr site of NU66 and In site of ZnIn 2 S 4 interface should be the main active center in NU66/ZIS heterojunctions.

MicroRNAs (miRNAs) are small noncoding RNAs, which regulate numerous cell functions by targeting mRNA for cleavage or translational repression, and have been found to play an important role in Alzheimer's disease (AD). Our study aimed to identify differentially expressed miRNAs in AD brain as a reference of potential therapeutic miRNAs or biomarkers for this disease. We used amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mice and age-matched wild-type (WT) littermates to determine the expression of miRNAs in the brain. MiRNAs were profiled by microarray, and differentially expressed miRNAs underwent target prediction and enrichment analysis. Microarray analysis revealed 56 differentially expressed miRNAs in AD mouse brain, which involved 39 miRNAs that were significantly upregulated and 19 that were downregulated at different ages. Among those miRNAs, a total of 11 miRNAs, including miR-342-3p, miR-342-5p, miR-376c-3p, and miR-301b-3p, were not only conserved in human but also predicted to have targets and signaling pathways closely related to the pathology of AD. In conclusion, in this study, differentially expressed miRNAs were identified in AD brain and proposed as biomarkers, which may have the potential to indicate AD progression. Despite being preliminary, these results may aid in investigating pathological hallmarks and identify effective therapeutic targets.

Vascular dementia (VaD) is a common cause of cognitive decline and dementia of vascular origin, but the precise pathological mechanisms are unknown, and so effective clinical treatments have not been established. Tilianin, the principal active compound of total flavonoid extract from Dracocephalum moldavica L., is a candidate therapy for cardio-cerebrovascular diseases in China. However, its potential in the treatment of VaD is unclear. The present study is aimed at investigating the protective effects of tilianin on VaD and exploring the underlying mechanism of the action. A model of VaD was established by permanent 2-vessel occlusion (2VO) in rats. Human neurons (hNCs) differentiated from human-induced pluripotent stem cells were used to establish an oxygen-glucose deprivation (OGD) model. The therapeutic effects and potential mechanisms of tilianin were identified using behavioral tests, histochemistry, and multiple molecular biology techniques such as Western blot analysis and gene silencing. The results demonstrated that tilianin modified spatial cognitive impairment, neurodegeneration, oxidation, and apoptosis in rats with VaD and protected hNCs against OGD by increasing cell viability and decreasing apoptosis rates. A study of the mechanism indicated that tilianin restored p-CaMKII/ERK1/2/CREB signaling in the hippocampus, maintaining hippocampus-independent memory. In addition, tilianin inhibited an ox-CaMKII/p38 MAPK/JNK/NF-κB associated inflammatory response caused by cerebral oxidative stress imbalance in rats with VaD. Furthermore, specific CaMKIIα siRNA action revealed that tilianin-exerted neuroprotection involved increase of neuronal viability, inhibition of apoptosis, and suppression of inflammation, which was dependent on CaMKIIα. In conclusion, the results suggested the neuroprotective effect of tilianin in VaD and the potential mechanism associated with dysfunction in the regulation of p-CaMKII-mediated long-term memory and oxidation and inflammation involved with ox-CaMKII, which may lay the foundation for clinical trials of tilianin for the treatment of VaD in the future.

Introduction: Post-stroke cognitive impairment (PSCI), which has a high morbidity, is closely associated with the recurrence and rehabilitation of ischemic stroke. There are 2 different stages of PSCI, including post-stroke cognitive impairment with no dementia (PSCIND) and post-stroke dementia (PSD). The latter has a significantly higher mortality rate than the previous one. Therefore, preventing the onset of PSD is of vital importance. However, there is no unequivocally effective prevention or treatment for PSCI, except intensive secondary prevention of stroke. The primary aim of this protocol is to explore whether acupuncture can improve cognitive function of patients with PSCIND and reduce the chances of developing PSD. On this bias, we also want to explore its possible mechanisms. Methods and analysis: A prospective, multicenter, large sample, randomized controlled trial will be conducted. A total of 360 eligible patients will be recruited from 5 different hospitals and randomly allocated into the acupuncture group (AG), sham acupuncture group (NAG), and waiting-list group (WLG) in a 1:1:1 ratio. The intervention period of NAG and AG will last 3 months (30 minutes per day, 3 times per week). Primary and secondary outcomes will be measured at baseline, 12 weeks (at the end of the intervention), 24 weeks (after the 12-week follow-up period), and 36 weeks (after the 24-week follow-up period). Resting-state and task-state functional MRI will be conducted at baseline and 12 weeks. Ethics and dissemination: The ethic committee of First Teaching Hospital of University of Traditional Chinese Medicine approved the study. Study results will be first informed to each participant and later disseminated to researchers, and the general public through courses, presentations and the internet, regardless of the magnitude or direction of effect. The results will also be documented in a published peer-reviewed academic journal. Registration: We have registered at ClinicalTrials.gov(ChiCTR2000033801).