Patient-Specific 3-Dimensional Model of Smooth Muscle Cell and Extracellular Matrix Dysfunction for the Study of Aortic Aneurysms.

INTRODUCTION: Abdominal aortic aneurysms (AAAs) are associated with overall high mortality in case of rupture. Since the pathophysiology is unclear, no adequate pharmacological therapy exists. Smooth muscle cells (SMCs) dysfunction and extracellular matrix (ECM) degradation have been proposed as underlying causes. We investigated SMC spatial organization and SMC-ECM interactions in our novel 3-dimensional (3D) vascular model. We validated our model for future use by comparing it to existing 2-dimensional (2D) cell culture. Our model can be used for translational studies of SMC and their role in AAA pathophysiology. MATERIALS AND METHODS: SMC isolated from the medial layer of were the aortic wall of controls and AAA patients seeded on electrospun poly-lactide-co-glycolide scaffolds and cultured for 5 weeks, after which endothelial cells (EC) are added. Cell morphology, orientation, mechanical properties and ECM production were quantified for validation and comparison between controls and patients. RESULTS: We show that cultured SMC proliferate into multiple layers after 5 weeks in culture and produce ECM proteins, mimicking their behavior in the medial aortic layer. EC attach to multilayered SMC, mimicking layer interactions. The novel SMC model exhibits viscoelastic properties comparable to biological vessels; cytoskeletal organization increases during the 5 weeks in culture; increased cytoskeletal alignment and decreased ECM production indicate different organization of AAA patients' cells compared with control. CONCLUSION: We present a valuable preclinical model of AAA constructed with patient specific cells with applications in both translational research and therapeutic developments. We observed SMC spatial reorganization in a time course of 5 weeks in our robust, patient-specific model of SMC-EC organization and ECM production.

Adverse effects of Δ9-tetrahydrocannabinol on neuronal bioenergetics during postnatal development.

Ongoing societal changes in views on the medical and recreational roles of cannabis increased the use of concentrated plant extracts with a Δ9-tetrahydrocannabinol (THC) content of more than 90%. Even though prenatal THC exposure is widely considered adverse for neuronal development, equivalent experimental data for young age cohorts are largely lacking. Here, we administered plant-derived THC (1 or 5 mg/kg) to mice daily during P5-P16 and P5-P35 and monitored its effects on hippocampal neuronal survival and specification by high-resolution imaging and iTRAQ proteomics, respectively. We found that THC indiscriminately affects pyramidal cells and both cannabinoid receptor 1+ (CB1R)+ and CB1R- interneurons by P16. THC particularly disrupted the expression of mitochondrial proteins (complexes I-IV), a change that had persisted even 4 months after the end of drug exposure. This was reflected by a THC-induced loss of membrane integrity occluding mitochondrial respiration and could be partially or completely rescued by pH stabilization, antioxidants, bypassed glycolysis, and targeting either mitochondrial soluble adenylyl cyclase or the mitochondrial voltage-dependent anion channel. Overall, THC exposure during infancy induces significant and long-lasting reorganization of neuronal circuits through mechanisms that, in large part, render cellular bioenergetics insufficient to sustain key developmental processes in otherwise healthy neurons.

Stereoselective Synthesis of the Isomers of Notoincisol A: Assigment of the Absolute Configuration of this Natural Product and Biological Evaluation.

The total syntheses of all stereoisomers of notoincisol A, a recently isolated natural product with potential anti-inflammatory activity, are reported. The asymmetric synthesis was conducted employing a lipase-mediated kinetic resolution, which enables easy access to all required chiral building blocks with the aim of establishing the absolute configuration of the naturally occurring isomer. This was achieved by comparison of optical properties of the isolated compound with the synthetic derivatives obtained. Moreover, an assessment of the biological activity on PPARγ (peroxisome proliferator-activated receptor gamma) as a prominent receptor related to inflammation is reported. Only the natural isomer was found to activate the PPARγ receptor, and this phenomenon could be explained based on molecular docking studies. In addition, the pharmacological profiles of the isomers were determined using the GABAA (gamma-aminobutyric acid A) ion channel receptor as a representative target for allosteric modulation related to diverse CNS activities. These compounds were found to be weak allosteric modulators of the α1ß3 and α1ß2γ2 receptor subtypes.

Molecular tools for GABAA receptors: High affinity ligands for ß1-containing subtypes.

γ-Aminobutyric acid type A (GABAA) receptors are pentameric GABA-gated chloride channels that are, in mammalians, drawn from a repertoire of 19 different genes, namely α1-6, ß1-3, γ1-3, δ, ε, θ, π and ρ1-3. The existence of this wide variety of subunits as well as their diverse assembly into different subunit compositions result in miscellaneous receptor subtypes. In combination with the large number of known and putative allosteric binding sites, this leads to a highly complex pharmacology. Recently, a novel binding site at extracellular α+/ß- interfaces was described as the site of modulatory action of several pyrazoloquinolinones. In this study we report a highly potent ligand from this class of compounds with pronounced ß1-selectivity that mainly lacks α-subunit selectivity. It constitutes the most potent ß1-selective positive allosteric modulatory ligand with known binding site. In addition, a proof of concept pyrazoloquinolinone ligand lacking the additional high affinity interaction with the benzodiazepine binding site is presented. Ultimately, such ligands can be used as invaluable molecular tools for the detection of ß1-containing receptor subtypes and the investigation of their abundance and distribution.