scholarly journals Modulation of γ-Secretase Activity by a Carborane-Based Flurbiprofen Analogue

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2843
Author(s):  
Stefan Saretz ◽  
Gabriele Basset ◽  
Liridona Useini ◽  
Markus Laube ◽  
Jens Pietzsch ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Pharmaceutical Research ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Blood Brain ◽  
Secretase Activity ◽  
Number Of Patients ◽  
Aging Populations ◽  
A Cell

All over the world, societies are facing rapidly aging populations combined with a growing number of patients suffering from Alzheimer’s disease (AD). One focus in pharmaceutical research to address this issue is on the reduction of the longer amyloid-β (Aβ) fragments in the brain by modulation of γ-secretase, a membrane-bound protease. R-Flurbiprofen (tarenflurbil) was studied in this regard but failed to show significant improvement in AD patients in a phase 3 clinical trial. This was mainly attributed to its low ability to cross the blood–brain barrier (BBB). Here, we present the synthesis and in vitro evaluation of a racemic meta-carborane analogue of flurbiprofen. By introducing the carborane moiety, the hydrophobicity could be shifted into a more favourable range for the penetration of the blood–brain barrier, evident by a logD7.4 value of 2.0. Furthermore, our analogue retained γ-secretase modulator activity in comparison to racemic flurbiprofen in a cell-based assay. These findings demonstrate the potential of carboranes as phenyl mimetics also in AD research.

scholarly journals Recent Progress in Microfluidic Models of the Blood-Brain Barrier

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 375 ◽  
Author(s):  
Lili Jiang ◽  
Shu Li ◽  
Junsong Zheng ◽  
Yan Li ◽  
Hui Huang
Keyword(s):  
Blood Brain Barrier ◽  
Pharmaceutical Research ◽  
Experimental Models ◽  
Brain Barrier ◽  
Design Parameters ◽  
Tight Junction Formation ◽  
Blood Brain ◽  
Micrometer Scale ◽  
Physical And Chemical

The blood-brain barrier (BBB) is a critical physical and chemical barrier that maintains brain homeostasis. Researchers in academia and industry are highly motivated to develop experimental models that can accurately mimic the physiological characteristics of the BBB. Microfluidic systems, which manipulate fluids at the micrometer scale, are ideal tools for simulating the BBB microenvironment. In this review, we summarized the progress in the design and evaluation of microfluidic in vitro BBB models, including advances in chip materials, porous membranes, the use of endothelial cells, the importance of shear stress, the detection specific markers to monitor tight junction formation and integrity, measurements of TEER and permeability. We also pointed out several shortcomings of the current microfluidic models. The purpose of this paper is to let the readers understand the characteristics of different types of model design, and select appropriate design parameters according to the research needs, so as to obtain the best experimental results. We believe that the microfluidics BBB models will play an important role in neuroscience and pharmaceutical research.

scholarly journals Robust Pharmacodynamic Effect of LY3202626, a Central Nervous System Penetrant, Low Dose BACE1 Inhibitor, in Humans and Nonclinical Species

2022 ◽  
pp. 1-15
Author(s):  
Brian A. Willis ◽  
Stephen L. Lowe ◽  
Scott A. Monk ◽  
Patrick J. Cocke ◽  
Christopher D. Aluise ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Low Dose ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Neuronal Cultures ◽  
Pharmacodynamic Effect ◽  
Bace1 Inhibitor ◽  
Blood Brain ◽  
Pharmacodynamic Profile

Background: The development of beta-site amyloid-beta precursor protein cleaving enzyme (BACE) 1 inhibitors for the treatment of Alzheimer’s disease requires optimization of inhibitor potency, selectivity, and brain penetration. Moreover, there is a need for low-dose compounds since liver toxicity was found with some BACE inhibitors. Objective: To determine whether the high in vitro potency and robust pharmacodynamic effect of the BACE inhibitor LY3202626 observed in nonclinical species translated to humans. Methods: The effect of LY3202626 versus vehicle on amyloid-β (Aβ) levels was evaluated in a series of in vitro assays, as well as in in vivo and multi-part clinical pharmacology studies. Aβ levels were measured using analytical biochemistry assays in brain, plasma, and cerebrospinal fluid (CSF) of mice, dogs and humans. Nonclinical data were analyzed using an ANOVA followed by Tukey’s post hoc test and clinical data used summary statistics. Results: LY3202626 exhibited significant human BACE1 inhibition, with an IC50 of 0.615±0.101 nM in a fluorescence resonance energy transfer assay and an EC50 of 0.275±0.176 nM for lowering Aβ 1–40 and 0.228±0.244 nM for Aβ 1–42 in PDAPP neuronal cultures. In dogs, CSF Aβ 1hboxx concentrations were significantly reduced by ∼80% at 9 hours following a 1.5 mg/kg dose. In humans, CSF Aβ 1–42 was reduced by 73.1±7.96 % following administration of 6 mg QD. LY3202626 was found to freely cross the blood-brain barrier in dogs and humans. Conclusion: LY3202626 is a potent BACE1 inhibitor with high blood-brain barrier permeability. The favorable safety and pharmacokinetic/pharmacodynamic profile of LY3202626 supports further clinical development.

scholarly journals Blood-Brain Barrier Permeable 2-Phenylbenzothiazolyl Iridi-um Complexes as Inhibitors and Probes of Aβ Aggregation

2021 ◽  
Author(s):  
Yiran Huang ◽  
Hanah Na ◽  
Liang Sun ◽  
Karna Terpstra ◽  
Kai Gui ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Day Treatment ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Blood Brain ◽  
Aβ Aggregation ◽  
D Values ◽  
Aβ Fibrils

The aggregation of amyloid β (Aβ) peptides is a significant hallmark of Alzheimer’s Disease (AD) and the inhibition and detection of Aβ aggregates are important for the treatment and diagnosis of AD. Herein, a series of benzothiazole-based luminescent Ir(III) complexes <b>HN-1</b> to <b>HN-8</b> were reported, which exhibit appreciable Aβ aggregation inhibition ability <i>in vitro</i> and in living cells. In addition, they are capable of inducing a fluorescence turn-on effect when binding to Aβ fibrils and oligomers. Most importantly, compared to previously reported cationic metal complexes, the neutral Ir complexes reported here show optimal Log D values, which suggest these compounds should have enhanced blood brain barrier (BBB) permeability. Most importantly, <i>in vivo</i> studies show that the neutral Ir complexes <b>HN-2</b>, <b>HN-3</b>, and <b>HN-8</b> successfully penetrate the BBB and stain amyloid plaques in AD mice brains after a 10-day treatment via i.p. injection, which is unprecedented for Ir(III) complexes, and thus can be used as lead compounds for AD therapeutics development.

scholarly journals Blood-Brain Barrier Permeable 2-Phenylbenzothiazolyl Iridi-um Complexes as Inhibitors and Probes of Aβ Aggregation

2021 ◽  
Author(s):  
Yiran Huang ◽  
Hanah Na ◽  
Liang Sun ◽  
Karna Terpstra ◽  
Kai Gui ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Day Treatment ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Blood Brain ◽  
Aβ Aggregation ◽  
D Values ◽  
Aβ Fibrils

The aggregation of amyloid β (Aβ) peptides is a significant hallmark of Alzheimer’s Disease (AD) and the inhibition and detection of Aβ aggregates are important for the treatment and diagnosis of AD. Herein, a series of benzothiazole-based luminescent Ir(III) complexes <b>HN-1</b> to <b>HN-8</b> were reported, which exhibit appreciable Aβ aggregation inhibition ability <i>in vitro</i> and in living cells. In addition, they are capable of inducing a fluorescence turn-on effect when binding to Aβ fibrils and oligomers. Most importantly, compared to previously reported cationic metal complexes, the neutral Ir complexes reported here show optimal Log D values, which suggest these compounds should have enhanced blood brain barrier (BBB) permeability. Most importantly, <i>in vivo</i> studies show that the neutral Ir complexes <b>HN-2</b>, <b>HN-3</b>, and <b>HN-8</b> successfully penetrate the BBB and stain amyloid plaques in AD mice brains after a 10-day treatment via i.p. injection, which is unprecedented for Ir(III) complexes, and thus can be used as lead compounds for AD therapeutics development.

scholarly journals Ketone Bodies Promote Amyloid-β1–40 Clearance in a Human in Vitro Blood–Brain Barrier Model

2020 ◽  
Vol 21 (3) ◽  
pp. 934 ◽  
Author(s):  
Romain Versele ◽  
Mariangela Corsi ◽  
Andrea Fuso ◽  
Emmanuel Sevin ◽  
Rita Businaro ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Ketone Bodies ◽  
Amyloid Β ◽  
Brain Barrier ◽  
Therapeutic Approaches ◽  
Protein Levels ◽  
Blood Brain ◽  
Aβ Clearance ◽  
The Brain

Alzheimer’s disease (AD) is characterized by the abnormal accumulation of amyloid-β (Aβ) peptides in the brain. The pathological process has not yet been clarified, although dysfunctional transport of Aβ across the blood–brain barrier (BBB) appears to be integral to disease development. At present, no effective therapeutic treatment against AD exists, and the adoption of a ketogenic diet (KD) or ketone body (KB) supplements have been investigated as potential new therapeutic approaches. Despite experimental evidence supporting the hypothesis that KBs reduce the Aβ load in the AD brain, little information is available about the effect of KBs on BBB and their effect on Aβ transport. Therefore, we used a human in vitro BBB model, brain-like endothelial cells (BLECs), to investigate the effect of KBs on the BBB and on Aβ transport. Our results show that KBs do not modify BBB integrity and do not cause toxicity to BLECs. Furthermore, the presence of KBs in the culture media was combined with higher MCT1 and GLUT1 protein levels in BLECs. In addition, KBs significantly enhanced the protein levels of LRP1, P-gp, and PICALM, described to be involved in Aβ clearance. Finally, the combined use of KBs promotes Aβ efflux across the BBB. Inhibition experiments demonstrated the involvement of LRP1 and P-gp in the efflux. This work provides evidence that KBs promote Aβ clearance from the brain to blood in addition to exciting perspectives for studying the use of KBs in therapeutic approaches.

scholarly journals Hollow Fiber Membranes of PCL and PCL/Graphene as Scaffolds with Potential to Develop In Vitro Blood—Brain Barrier Models

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 161
Author(s):  
Marián Mantecón-Oria ◽  
Nazely Diban ◽  
Maria T. Berciano ◽  
Maria J. Rivero ◽  
Oana David ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Cell Line ◽  
Blood Brain Barrier ◽  
Hollow Fiber ◽  
Water Flux ◽  
Pharmaceutical Research ◽  
Cell Types ◽  
Brain Barrier ◽  
Blood Brain

There is a huge interest in developing novel hollow fiber (HF) membranes able to modulate neural differentiation to produce in vitro blood–brain barrier (BBB) models for biomedical and pharmaceutical research, due to the low cell-inductive properties of the polymer HFs used in current BBB models. In this work, poly(ε-caprolactone) (PCL) and composite PCL/graphene (PCL/G) HF membranes were prepared by phase inversion and were characterized in terms of mechanical, electrical, morphological, chemical, and mass transport properties. The presence of graphene in PCL/G membranes enlarged the pore size and the water flux and presented significantly higher electrical conductivity than PCL HFs. A biocompatibility assay showed that PCL/G HFs significantly increased C6 cells adhesion and differentiation towards astrocytes, which may be attributed to their higher electrical conductivity in comparison to PCL HFs. On the other hand, PCL/G membranes produced a cytotoxic effect on the endothelial cell line HUVEC presumably related with a higher production of intracellular reactive oxygen species induced by the nanomaterial in this particular cell line. These results prove the potential of PCL HF membranes to grow endothelial cells and PCL/G HF membranes to differentiate astrocytes, the two characteristic cell types that could develop in vitro BBB models in future 3D co-culture systems.

scholarly journals Cellular Prion Protein Participates in Amyloid-β Transcytosis across the Blood—Brain Barrier

2012 ◽  
Vol 32 (4) ◽  
pp. 628-632 ◽  
Author(s):  
Thorsten Pflanzner ◽  
Benjamin Petsch ◽  
Bettina André-Dohmen ◽  
Andreas Müller-Schiffmann ◽  
Sabrina Tschickardt ◽  
...  
Keyword(s):  
Prion Protein ◽  
Blood Brain Barrier ◽  
Amyloid Β ◽  
Cellular Prion Protein ◽  
Brain Barrier ◽  
Putative Receptor ◽  
Blood Brain ◽  
In Vitro Bbb Model

The blood—brain barrier (BBB) facilitates amyloid-β (Aβ) exchange between the blood and the brain. Here, we found that the cellular prion protein (PrPc), a putative receptor implicated in mediating Aβ neurotoxicity in Alzheimer's disease (AD), participates in Aβ transcytosis across the BBB. Using an in vitro BBB model, [125I]-Aβ1–40 transcytosis was reduced by genetic knockout of PrPc or after addition of a competing PrPc-specific antibody. Furthermore, we provide evidence that PrPc is expressed in endothelial cells and, that monomeric Aβ1–40 binds to PrPc. These observations provide new mechanistic insights into the role of PrPc in AD.

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