Regulation of Glucose Insulinotropic Peptide and Intestinal Glucose Transporters in the Diet-Induced Obese Mouse.

Our recent studies have shown that glucose-dependent insulinotropic polypeptide (GIP), but not glucagon-like peptide 1 (GLP-1), augments Na-glucose transporter 1- (SGLT1-) mediated glucose absorption in mouse jejunum. Na-dependent glucose absorption sharply rose and peaked in 3 months of high-fat (i.e., obese) compared to normal (i.e., normal weight) diet fed animals. Previous studies have shown that GIP-augmented SGLT1 and PEPT1 (peptide transporter 1) are regulated by protein kinase A (PKA) signaling in mouse jejunum. Additional studies have indicated that cAMP and PI3 kinase signaling augment PEPT1 through EPAC and AKT activation pathways, respectively, through increased apical PEPT1 trafficking in intestinal epithelial cells. However, little is known about how the signaling glucose transport paradigm is altered over a long period. Early on, increased glucose absorption occurs through SGLT1, but as the obesity and diabetes progress, there is a dramatic shift towards a Na-independent mechanism. Surprisingly, at the peak of glucose absorption during the fifth month of the progression of obesity, the SGLT1 activity was severely depressed, while a Na-independent glucose absorptive process begins to appear. Since glucose transporter 2 (GLUT2) is expressed on the apical membrane of the small intestine in obese patients and animal models of obesity, it was hypothesized to be the new more efficient route. Western blot analyses and biotinylation of the apical membrane revealed that the GIP expression increases in the obese animals and its trafficking to the apical membrane increases with the GIP treatment.

Discovery of Mycobacterium tuberculosis Rv3364c-Derived Small Molecules as Potential Therapeutic Agents to Target SNX9 for Sepsis.

The serine protease inhibitor Rv3364c of Mycobacterium tuberculosis (MTB) is highly expressed in cells during MTB exposure. In this study, we showed that the 12WLVSKF17 motif of Rv3364c interacts with the BAR domain of SNX9 and inhibits endosome trafficking to interact with p47phox, thereby suppressing TLR4 inflammatory signaling in macrophages. Derived from the structure of this Rv3364c peptide motif, 2,4-diamino-6-(4-tert-butylphenyl)-1,3,5-trazine, DATPT as a 12WLVSKF17 peptide-mimetic small molecule has been identified. DATPT can block the SNX9-p47phox interaction in the endosome and suppress reactive oxygen species and inflammatory cytokine production; it demonstrated significant therapeutic effects in a mouse model of cecal ligation and puncture-induced sepsis. DATPT has considerably improved potency, with an IC50 500-fold (in vitro) or 2000-fold (in vivo) lower than that of the 12WLVSKF17 peptide. Furthermore, DATPT shows potent antibacterial activities by reduction in ATP production and leakage of intracellular ATP out of bacteria. These results provide evidence for peptide-derived small molecule DATPT with anti-inflammatory and antibacterial functions for the treatment of sepsis.

Activating BK channels ameliorates vascular smooth muscle calcification through Akt signaling.

Vascular calcification (VC) is characterized by pathological depositions of calcium and phosphate in the arteries and veins via an active cell-regulated process, in which vascular smooth muscle cells (VSMCs) transform into osteoblast/chondrocyte-like cells as in bone formation. VC is associated with significant morbidity and mortality in chronic kidney disease (CKD) and cardiovascular disease, but the underlying mechanisms remain unclear. In this study we investigated the role of large-conductance calcium-activated potassium (BK) channels in 3 experimental VC models. VC was induced in vascular smooth muscle cells (VSMCs) by ß-glycerophosphate (ß-GP), or in rats by subtotal nephrectomy, or in mice by high-dosage vitamin D3. We showed that the expression of BK channels in the artery of CKD rats with VC and in ß-GP-treated VSMCs was significantly decreased, which was functionally confirmed by patch-clamp recording. In ß-GP-treated VSMCs, BK channel opener NS1619 (20 µM) significantly alleviated VC by decreasing calcium content and alkaline phosphatase activity. Furthermore, NS1619 decreased mRNA expression of ostoegenic genes OCN and OPN, as well as Runx2 (a key transcription factor involved in preosteoblast to osteoblast differentiation), and increased the expression of α-SMA protein, whereas BK channel inhibitor paxilline (10 µM) caused the opposite effects. In primary cultured VSMCs from BK-/- mice, BK deficiency aggravated calcification as did BK channel inhibitor in normal VSMCs. Moreover, calcification was more severe in thoracic aorta rings of BK-/- mice than in those of wild-type littermates. Administration of BK channel activator BMS191011 (10 mg· kg-1 ·d-1) in high-dosage vitamin D3-treated mice significantly ameliorated calcification. Finally, co-treatment with Akt inhibitor MK2206 (1 µM) or FoxO1 inhibitor AS1842856 (3 µM) in calcified VSMCs abrogated the effects of BK channel opener NS1619. Taken together, activation of BK channels ameliorates VC via Akt/FoxO1 signaling pathways. Strategies to activate BK channels and/or enhance BK channel expression may offer therapeutic avenues to control VC.

Trans-Chalcone Plus Baicalein Synergistically Reduce Intracellular Amyloid Beta (Aß42) and Protect from Aß42 Induced Oxidative Damage in Yeast Models of Alzheimer's Disease.

Finding an effective therapeutic to prevent or cure AD has been difficult due to the complexity of the brain and limited experimental models. This study utilized unmodified and genetically modified Saccharomyces cerevisiae as model organisms to find potential natural bioactive compounds capable of reducing intracellular amyloid beta 42 (Aß42) and associated oxidative damage. Eleven natural bioactive compounds including mangiferin, quercetin, rutin, resveratrol, epigallocatechin gallate (EGCG), urolithin A, oleuropein, rosmarinic acid, salvianolic acid B, baicalein and trans-chalcone were screened for their ability to reduce intracellular green fluorescent protein tagged Aß42 (GFP-Aß42) levels. The two most effective compounds from the screens were combined in varying concentrations of each to study the combined capacity to reduce GFP-Aß42. The most effective combinations were examined for their effect on growth rate, turnover of native Aß42 and reactive oxygen species (ROS). The bioactive compounds except mangiferin and urolithin A significantly reduced intracellular GFP-Aß42 levels. Baicalein and trans-chalcone were the most effective compounds among those that were screened. The combination of baicalein and trans-chalcone synergistically reduced GFP-Aß42 levels. A combination of 15 µM trans-chalcone and 8 µM baicalein was found to be the most synergistic combination. The combination of the two compounds significantly reduced ROS and Aß42 levels in yeast cells expressing native Aß42 without affecting growth of the cells. These findings suggest that the combination of baicalein and trans-chalcone could be a promising multifactorial therapeutic strategy to cure or prevent AD. However, further studies are recommended to look for similar cytoprotective activity in humans and to find an optimal dosage.

Alteration of gene expression in reactive astrocytes induced by Aß1-42 using low dose of methamphetamine.

BACKGROUND: Alzheimer's disease (AD) is a degenerative brain disorder. Due to the relationship between the functional loss of astrocytes and AD, the present study aims to evaluate the effects of the low dose of methamphetamine (METH) on primary fetal human astrocytes under a stress paradigm as a possible model for AD. METHODS AND RESULTS: The groups in this study included Aß (Group 1), METH (Group 2), Aß + METH (METH after adding Aß for 24 h) (Group 3 as treated group), METH + Aß (Aß after adding METH for 24 h) (Group 4 as prevention group), and control group. Then, the gene expression of Bax, Bcl-X, PKCα, GSK3ß, and Cdk5 was evaluated. In addition, phosphorylated tau, p-GSK3ß, GSK3ß, and GSK3α proteins were assessed by western blotting. Further, cell cycle arrest and apoptosis were checked by flow cytometry and Hoechst staining. Based on the results, the expression of GSK3ß, Cdk5, and PKCα genes decreased in the prevention group, while GSK3ß and Cdk5 were amplified in the treatment group. Furthermore, the level of GSK3α and GSK3ß proteins in the treatment group increased, while it decreased in the prevention group. Additionally, a decrease occurred in the percentage of necrosis and early apoptosis in the treatment and prevention groups. The results of the cell cycle indicated that G1 increased, while G2 decreased in the prevention group. CONCLUSION: The pure form of METH can prevent from activating GSK-3ß and CdK-5, as well as enhanced activity of PKCα to inhibit phosphorylated tau protein. Therefore, a low dose of METH may have a protective effect or reducing role in the pathway of tau production in reactive astrocytes.

Alzheimer's Disease-Related Neuropathology Among Patients with Medication Treated Type 2 Diabetes in a Community-Based Autopsy Cohort.

BACKGROUND: Diabetes is a risk factor for Alzheimer's disease and related dementias (ADRD). Epidemiologic evidence shows an association between diabetes medications and ADRD risk; cell and mouse models show diabetes medication association with AD-related neuropathologic change (ADNC). OBJECTIVE: This hypothesis-generating analysis aimed to describe autopsy-measured ADNC for individuals who used diabetes medications. METHODS: Descriptive analysis of ADNC for Adult Changes in Thought (ACT) Study autopsy cohort who used diabetes medications, including sulfonylureas, insulin, and biguanides; total N = 118. ADNC included amyloid plaque distribution (Thal phasing), neurofibrillary tangle (NFT) distribution (Braak stage), and cortical neuritic plaque density (CERAD score). We also examined quantitative measures of ADNC using the means of standardized Histelide measures of cortical PHF-tau and Aß1-42. Adjusted analyses control for age at death, sex, education, APOE genotype, and diabetes complication severity index. RESULTS: Adjusted analyses showed no significant association between any drug class and traditional neuropathologic measures compared to nonusers of that class. In adjusted Histelide analyses, any insulin use was associated with lower mean levels of Aß1-42 (-0.57 (CI: -1.12, -0.02)) compared to nonusers. Five years of sulfonylureas and of biguanides use was associated with lower levels of Aß1-42 compared to nonusers (-0.15 (CI: -0.28, -0.02), -0.31 (CI: -0.54, -0.07), respectively). CONCLUSION: Some evidence exists that diabetes medications are associated with lower levels of Aß1-42, but not traditional measures of neuropathology. Future studies are needed in larger samples to build understanding of the mechanisms between diabetes, its medications, and ADRD, and to potentially repurpose existing medications for prevention or delay of ADRD.

Intranasal 15d-PGJ2 ameliorates brain glucose hypometabolism via PPARγ-dependent activation of PGC-1α/GLUT4 signalling in APP/PS1 transgenic mice.

Targeting the common molecular mechanism of type 2 diabetes mellitus and Alzheimer's disease (AD), including dysregulation of glucose metabolism, insulin resistance, and neuroinflammation, might be an efficient treatment strategy for AD. Previous studies have shown that 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), an endogenous PPARγ agonist, has anti-inflammatory, insulin sensitizing and anti-diabetic effects. However, whether 15d-PGJ2 has beneficial effects on AD remains to be elucidated. In the present study, we found that intranasal administration of 15d-PGJ2 (300 ng/30 µL/day) for 3 months significantly inhibited Aß plaques, suppressed neuroinflammation, and attenuated cognitive deficits in APP/PS1 transgenic mice. Interestingly, 15d-PGJ2 treatment could increase brain glucose uptake, as detected by 18F-FDG microPET imaging, and co-localization of GLUT4 and NeuN in the hippocampus of APP/PS1 mice. Furthermore, 15d-PGJ2 markedly increased the expression of PPARγ and PGC-1α, upregulated GLUT4, and decreased the phosphorylation of IRS-1 (Ser616) in the hippocampus of APP/PS1 mice. Importantly, co-administration of a PPARγ antagonist GW9662 abrogated these protective effects of 15d-PGJ2. Collectively, intranasal 15d-PGJ2 conferred protective effects against AD by activating PPARγ-dependent PGC-1α/GLUT4 signalling. The PPARγ agonist 15d-PGJ2 might be a potential therapeutic drug for AD.

Vitamin K2 protects against Aß42-induced neurotoxicity by activating autophagy and improving mitochondrial function in Drosophila.

OBJECTIVE: Alzheimer disease is characterized by progressive decline in cognitive function due to neurodegeneration induced by accumulation of Aß and hyperphosphorylated tau protein. This study was conducted to explore the protective effect of vitamin K2 against Aß42-induced neurotoxicity. METHODS: Alzheimer disease transgenic Drosophila model used in this study was amyloid beta with the arctic mutation expressed in neurons. Alzheimer disease flies were treated with vitamin K2 for 28 days after eclosion. Aß42 level in brain was detected by ELISA. Autophagy-related genes and NDUFS3, the core subunit of mitochondrial complex I, were examined using real-Time PCR (RT-PCR) and western blot analysis. RESULTS: Vitamin K2 improved climbing ability (P = 0.0105), prolonged lifespan (P < 0.0001) and decreased Aß42 levels (P = 0.0267), upregulated the expression of LC3 and Beclin1(P = 0.0012 and P = 0.0175, respectively), increased the conversion of LC3I to LC3II (P = 0.0206) and decreased p62 level (P =0.0115) in Alzheimer disease flies. In addition, vitamin K2 upregulated the expression of NDUFS3 (P = 0.001) and increased ATP production (P = 0.0033) in Alzheimer disease flies. CONCLUSION: It seems that vitamin K2 protect against Aß42-induced neurotoxicity by activation of autophagy and rescue mitochondrial dysfunction, which suggests that it may be a potential valuable therapeutic approach for Alzheimer disease.

Deferoxamine reduces amyloid-beta peptides genesis and alleviates neural apoptosis after traumatic brain injury.

Traumatic brain injury (TBI) is recognized as the most influential risk factor for neurodegenerative diseases later in life, including Alzheimer's disease. The aberrant genesis of amyloid-ß peptides, which is triggered by TBI, is associated with the development of Alzheimer's disease. Evidence suggests that iron plays a role in both the production of amyloid-ß and its neurotoxicity, and iron overload has been noted in the brain after TBI. We therefore investigated the effects of an iron-chelating treatment on amyloid-ß genesis in a weight-drop model of TBI in mice. Human brain samples were obtained from patients undergoing surgery for severe brain trauma. The Institute of Cancer Research mice were treated with deferoxamine by intraperitoneal injection after TBI induction. Changes in amyloid-ß(1-42) were assessed using western blot and immunohistochemical staining. Ferritin was also detected using western blot to investigate iron deposition in the mice brain. Immunofluorescent terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was also performed to evaluate neural apoptosis. The amyloid-ß(1-42) was markedly elevated after TBI in both humans and mice. Deferoxamine treatment in mice significantly decreased the levels of both amyloid-ß(1-42) and ferritin in the brain, and reduced TBI-induced neural cell apoptosis. The iron chelator deferoxamine can alleviate the increase of amyloid-ß(1-42) in the brain after TBI, and may therefore be a potential therapeutic strategy to prevent TBI patients from undergoing neurodegenerative processes.

Inhibition of tau amyloid formation and disruption of its preformed fibrils by Naphthoquinone-Dopamine hybrid.

Misfolding and aggregation of tau protein, into pathological amyloids, are hallmarks of a group of neurodegenerative diseases collectively termed tauopathies and their modulation may be therapeutically valuable. Herein, we describe the synthesis and characterization of a dopamine-based hybrid molecule, naphthoquinone-dopamine (NQDA). Using thioflavin S assay, CD, transmission electron microscopy, dynamic light scattering, Congo Red birefringence, and large unilamellar vesicle leakage assays, we demonstrated its efficacy in inhibiting the in vitro aggregation of key tau-derived amyloidogenic fragments, PHF6 (VQIVYK) and PHF6* (VQIINK), prime drivers of aggregation of full-length tau in disease pathology. Isothermal titration calorimetry analysis revealed that the interaction between NQDA and PHF6 is spontaneous and has significant binding efficiency driven by both entropic and enthalpic processes. Furthermore, NQDA efficiently disassembled preformed fibrils of PHF6 and PHF6* into nontoxic species. Molecular dynamic simulations supported the in vitro results and provided a plausible mode of binding of NQDA with PHF6 fibril. NQDA was also capable of inhibiting the aggregation of full-length tau protein and disrupting its preformed fibrils in vitro in a dose-dependent manner. In a comparative study, the IC50 value (50% inhibition of fibril formation) of NQDA in inhibiting the aggregation of PHF6 (25 µm) was ~ 17 µm, which is lower than for other bona fide amyloid inhibitors, naphthoquinone-tryptophan, rosmarinic acid, epigallocatechin gallate, ~ 21, ~ 77, or ~ 19 µm, respectively. Comparable superiority of NQDA was observed for inhibition of PHF6*. These findings suggest that NQDA can be a useful scaffold for designing new therapeutics for Alzheimer's disease and other tauopathies.

Ang (1-7)/Mas receptor-axis activation promotes amyloid beta-induced altered mitochondrial bioenergetics in discrete brain regions of Alzheimer's disease-like rats.

Renin Angiotensin System plays significant role in the memory acquisition and consolidation apart from its hemodynamic function in the pathophysiology of Alzheimer's disease (AD). It has been reported that Ang (1-7) ameliorates the cognitive impairment in experimental animals. However, the effect of Ang (1-7)/Mas receptor signaling is yet to be explored in Aß42-induced memory impairment. Aß42 was intracerebroventricularly injected into the male rats on day-1 (D-1) of the experimental schedule of 14 days. All the drugs were administered from D-1 to D-14 in the study design. Aß42 significantly increased the escape latency during Morris water maze (MWM) test on D-10 to13 in the animals. Further, Aß42 significantly decreased the time spent and percentage of total distance travelled in the target quadrant of the rats on D-14 in the MWM test. Aß42 also significantly decreased the spontaneous alteration behavior on D-14 during Y-maze test. Moreover, there was a significant increase in the level of Aß42, decrease in the cholinergic function (in terms of decreased acetylcholine and activity of cholinesterase, and increased activity of acetylcholinesterase), mitochondrial function, integrity and bioenergetics, and apoptosis in all the rat brain regions. Further, Aß42 significantly decreased the level of expression of heme oxygenase-1 in all the rat brain regions. Ang (1-7) attenuated Aß42-induced changes in the behavioral, biochemical and molecular observations in all the selected rat brain regions. However, A779, Mas receptor blocker, significantly abolished the beneficial effects of Ang (1-7) in Aß42-induced cognitive deficit animals. These observations clearly indicate that the Ang (1-7)/Mas receptor activation could be a potential alternative option in the management of AD.

PERK activator CCT020312 prevents inflammation-mediated osteoporosis in the ovariectomized rats.

OBJECTIVE: To investigate the therapeutic effects of PERK activator CCT020312 (CCT) on inflammation-mediated osteoporosis (IMO) in ovariectomized rats. METHODS: Rats were divided into Sham, IMO, IMO + 1 mg/kg CCT and IMO + 2 mg/kg CCT groups. IMO models were constructed by bilateral ovariectomy (OVX) on 1st day followed by injection with magnesium silicate (Talc) on the 59th day. Sham rats did not undergo OVX surgery and were injected with saline instead of Talc. From 60th to 79th day, rats were treated with DMSO (vehicle control) in the Sham and IMO groups, and 1 or 2 mg/kg CCT020312 in treatment groups. Osteopontin (OPN), osteocalcin (OCN), tartrate-resistant acid phosphatase (TRAP), C-terminal telopeptide of type I collagen (CTX-I), and pro-inflammatory factors were measured on the 80th day. ProdigyDEXA was used to evaluate bone mineral density and content (BMD/BMC). Bone volume/total volume (BV/TV), connectivity density (Conn.D), trabecular number (Tb.N), and trabecular separation (Tb.Sp) was assessed using 3D micro-CT scanner. RESULTS: CCT up-regulated Conn.D, BV/TV, and Tb.N, but down-regulated Tb.Sp in IMO rats. Besides, the declined femoral BMD and BMC in IMO rats were elevated after CCT treatment. Besides, IMO rats represented declined OPN and OCN, as well as increased TRAP, CTX-I, and pro-inflammatory factors, whereas those in the treatment groups were ameliorated regarding these indexes, with 2 mg/kg CCT showing better effect. CONCLUSION: PERK activator CCT020312 can be served as a new therapeutic option for the protection against bone loss in the OVX rat model associated with inflammation probably by manipulating inflammatory factors.

Consequences of Parental Opioid Exposure on Neurophysiology, Behavior, and Health in the Next Generations.

Substance abuse and the ongoing opioid epidemic represents a large societal burden. This review will consider the long-term impact of opioid exposure on future generations. Prenatal, perinatal, and preconception exposure are reviewed with discussion of both maternal and paternal influences. Opioid exposure can have long-lasting effects on reproductive function, gametogenesis, and germline epigenetic programming, which can influence embryogenesis and alter the developmental trajectory of progeny. The potential mechanisms by which preconception maternal and paternal opioid exposure produce deleterious consequences on the health, behavior, and physiology of offspring that have been identified by clinical and animal studies will be discussed. The timing, nature, dosing, and duration of prenatal opioid exposure combined with other important environmental considerations influence the extent to which these manipulations affect parents and their progeny. Epigenetic inheritance refers to the transmission of environmental insults across generations via mechanisms independent of the DNA sequence. This topic will be further explored in the context of prenatal, perinatal, and preconception opioid exposure for both the maternal and paternal lineage.

Comparison of Aß (1-40, 1-28, 11-22, and 29-40) aggregation processes and inhibition of toxic species generated in early stages of aggregation by a water-soluble ruthenium complex.

Neurotoxicity of amyloid beta (Aß) species generated in early stages of aggregation has been associated with development of Alzheimer's disease (AD). Consequently, the field of action of compounds that can identify and inhibit the formation of these species has enlarged considerably. This study investigates the effect and influence of the luminescent, water soluble metal complex cis-[Ru(phen)2(3,4Apy)2]2+ (RuApy, 3,4Apy = 3,4-diaminopyridine, phen = 1,10-phenanthroline) on the aggregation process and toxicity of Aß1-40 and its Aß1-28, Aß11-22 and Aß29-40 fragments since their early stages. The absence of correlation between the conformations generated by Aß fragments and the full length 1-40 peptide during aggregation and the absence of toxicity of Aß fragments to PC12 cells in all stages of aggregation indicated that the aggregation pathway and toxicity found to the full-length Aß1-40 depends on specific interactions between the three fragments. The toxicity of Aß1-40 was dependent on the aggregation step investigated: species generated at the beginning (15 min) of aggregation were toxic, whereas mature (120 min) fibrils were not. The RuApy complex is not toxic to PC12 cells up to 60 µM, and does not interfere with the aggregation pathway of the Aß fragments, but interferes with the aggregation of Aß1-40 and protects the PC12 cells, maintaining 100% of cell viability against the toxicity of Aß1-40 species generated in early stages of aggregation.

Fast green FCF inhibits Aß fibrillogenesis, disintegrates mature fibrils, reduces the cytotoxicity, and attenuates Aß-induced cognitive impairment in mice.

Fast green FCF (FGF) is often used in foods, pharmaceuticals, and cosmetics. However, little is known about the interactions of FGF with amyloid-ß protein (Aß) associated with Alzheimer's disease. In this study, the inhibitory effects of FGF on Aß fibrillogenesis, the disruption of preformed Aß fibrils, the reduction of Aß-induced cytotoxicity, and the attenuation of Aß-induced learning and memory impairments in mice were investigated. FGF significantly inhibited Aß fibrillogenesis and disintegrated the mature fibrils as evidenced by thioflavin T fluorescence and atomic force microscopy studies. Co-incubation of Aß with FGF greatly reduced Aß-induced cytotoxicity in vitro. Moreover, FGF showed a protective effect against cognitive impairment in Aß-treated mice. Molecular dynamics simulations further showed that FGF could synergistically interact with the Aß17-42 pentamer via electrostatic interactions, hydrogen bonds and π-π interactions, which reduced the ß-sheet content, and disordered random coils and bend structures of the Aß17-42 pentamer. This study offers a comprehensive understanding of the inhibitory effects of FGF against Aß neurotoxicity, which is critical for the search of effective food additives that can combat amyloid-associated disease.

Exposure to traffic-generated air pollution promotes alterations in the integrity of the brain microvasculature and inflammation in female ApoE-/- mice.

Traffic-generated air pollutants have been correlated with alterations in blood-brain barrier (BBB) integrity, which is associated with pathologies in the central nervous system (CNS). Much of the existing literature investigating the effects of air pollution in the CNS has predominately been reported in males, with little known regarding the effects in females. As such, this study characterized the effects of inhalation exposure to mixed vehicle emissions (MVE), as well as the presence of female sex hormones, in the CNS of female ApoE-/- mice, which included cohorts of both ovariectomized (ov-) and ovary-intact (ov+) mice. Ov + and ov- were placed on a high-fat diet and randomly grouped to be exposed to either filtered-air (FA) or MVE (200 PM/m3: 50 µg PM/m3 gasoline engine + 150 µg PM/m3 from diesel engine emissions) for 6 h/d, 7d/wk, for 30d. MVE-exposure resulted in altered cerebral microvascular integrity and permeability, as determined by the decreased immunofluorescent expression of tight junction (TJ) proteins, occludin, and claudin-5, and increased IgG extravasation into the cerebral parenchyma, compared to FA controls, regardless of ovary status. Associated with the altered cerebral microvascular integrity, we also observed an increase in matrix metalloproteinases (MMPs) -2/9 activity in the MVE ov+, MVE ov-, and FA ov- groups, compared to FA ov+. There was also elevated expression of intracellular adhesion molecule (ICAM)-1, inflammatory interleukins (IL-1, IL-1ß), and tumor necrosis factor (TNF-α) mRNA in the cerebrum of MVE ov + and MVE ov- animals. IκB kinase (IKK) subunits IKKα and IKKß mRNA expressions were upregulated in the cerebrum of MVE ov- and FA ov- mice. Our findings indicate that MVE exposure mediates altered integrity of the cerebral microvasculature correlated with increased MMP-2/9 activity and inflammatory signaling, regardless of female hormones present.

Pharmacodynamic Comparison of Ticagrelor Monotherapy Versus Ticagrelor and Aspirin in Patients After Percutaneous Coronary Intervention: The TEMPLATE (Ticagrelor Monotherapy and Platelet Reactivity) Randomized Controlled Trial.

Background To assess differences in platelet inhibition during ticagrelor monotherapy (TIC) or dual therapy with ticagrelor and aspirin (TIC+ASP) in patients after percutaneous coronary intervention using a comprehensive panel of functional tests. Methods and Results In a single-center parallel group, open label, randomized controlled trial, 110 participants were randomized to receive either TIC (n=55) or TIC+ASP (n=55) for 4 weeks. The primary outcome was the platelet aggregation response with 10 µmol/L thrombin receptor activation peptide-6 (TRAP-6). The secondary outcomes were platelet aggregation responses and binding of surface activation markers with a panel of other activators. The mean percentage aggregation for 10 µmol/L TRAP-6 was similar for the TIC and TIC+ASP groups (mean difference+4.29; 95% CI, -0.87 to +9.46). Aggregation was higher in the TIC group compared with the TIC+ASP group with 1 µg/mL (+6.47; +2.04 to +10.90) and 0.5 µg/mL (+14.00; +7.63 to +20.39) collagen related peptide. Aggregation responses with 5 µmol/L TRAP-6, 5 µmol/L or 2.5 µmol/L thromboxane A2 receptor agonist and surface activation marker binding with 5 µmol/L TRAP-6 or 0.5 µg/mL collagen related peptide were the same between the treatment groups. Conclusions Patients with PCI show similar levels of inhibition of most platelet activation pathways with TIC compared with dual therapy with TIC + ASP. However, the greater aggregation response with collagen related peptide during TIC indicates incomplete inhibition of glycoprotein VI (collagen) receptor-mediated platelet activation. This difference in pharmacodynamic response to anti-platelet medication may contribute to the lower bleeding rates observed with TIC compared with dual antiplatelet therapy in recent clinical trials. Registration Information URL: https://www.isrctn.com; Unique Identifier ISRCTN84335288.

In Vitro Effects of (+)MK-801 (dizocilpine) and Memantine on ß-Amyloid Peptides Linked to Alzheimer's Disease.

An in vitro effect of (+)MK-801 (dizocilpine), an inhibitor of the glutamate/NMDA and nicotinic acetylcholine receptors, on the Aß[1-42] and Aß[1-40] peptides is described and compared to that of memantine. Memantine has been approved by the U.S. Food and Drug Administration for the treatment of mild-moderate Alzheimer's disease. Both compounds accelerated the formation of a ß-sheet structure by Aß[1-42], (+)MK-801 more rapidly than memantine, as observed in a thioflavin T fluorescence assay. The acceleration was followed by a decrease in the fluorescence signal that was not observed when the ligand was absent. Nuclear magnetic resonance spectra of the soluble peptides in the presence and absence of (+)MK-801 demonstrated that the monomeric form did not bind (+)MK-801 and that in the presence of (+)MK-801 the concentration of the monomeric form progressively decreased. Small angle X-ray scattering confirmed that the presence of (+)MK-801 resulted in a more rapid and characteristic transition to an insoluble form. These results suggest that (+)MK-801 and memantine accelerate the transition of Aß[1-42] and Aß[1-40] to ThT-negative insoluble forms.

Chiral gold nanoparticles enantioselectively rescue memory deficits in a mouse model of Alzheimer's disease.

Preventing aggregation of amyloid beta (Aß) peptides is a promising strategy for the treatment of Alzheimer's disease (AD), and gold nanoparticles have previously been explored as a potential anti-Aß therapeutics. Here we design and prepare 3.3 nm L- and D-glutathione stabilized gold nanoparticles (denoted as L3.3 and D3.3, respectively). Both chiral nanoparticles are able to inhibit aggregation of Aß42 and cross the blood-brain barrier (BBB) following intravenous administration without noticeable toxicity. D3.3 possesses a larger binding affinity to Aß42 and higher brain biodistribution compared with its enantiomer L3.3, giving rise to stronger inhibition of Aß42 fibrillation and better rescue of behavioral impairments in AD model mice. This conjugation of a small nanoparticle with chiral recognition moiety provides a potential therapeutic approach for AD.

Effect of escitalopram dose and treatment duration on CSF Aß levels in healthy older adults: A controlled clinical trial.

OBJECTIVE: To determine whether treatment with escitalopram compared with placebo would lower CSF ß-amyloid 42 (Aß42) levels. RATIONALE: Serotonin signaling suppresses Aß42 in animal models of Alzheimer disease (AD) and young healthy humans. In a prospective study in older adults, we examined dose and treatment duration effects of escitalopram. METHODS: Using lumbar punctures to sample CSF levels before and after a course of escitalopram treatment, cognitively normal older adults (n = 114) were assigned to placebo, 20 mg escitalopram × 2 weeks, 20 mg escitalopram × 8 weeks, or 30 mg escitalopram × 8 weeks; CSF sampled pretreatment and posttreatment and within-subject percent change in Aß42 was used as the primary outcome in subsequent analyses. RESULTS: An overall 9.4% greater reduction in CSF Aß42 was found in escitalopram-treated compared with placebo-treated groups (p < 0.001, 95% confidence interval [CI] 4.9%-14.2%, d = 0.81). Positive baseline Aß status (CSF Aß42 levels <250 pg/mL) was associated with smaller Aß42 reduction (p = 0.006, 95% CI -16.7% to 0.5%, d = -0.52) compared with negative baseline amyloid status (CSF Aß42 levels >250 pg/mL). CONCLUSIONS: Short-term longitudinal doses of escitalopram decreased CSF Aß42 in cognitively normal older adults, the target group for AD prevention. CLINICALTRIALSGOV IDENTIFIER: NCT02161458. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for cognitively normal older adults, escitalopram decreases CSF Aß42.