Comparative study of differentiating human pluripotent stem cells into vascular smooth muscle cells in hydrogel-based culture methods

Vascular smooth muscle cells (VSMCs), which provides structural integrity and regulates the diameter of vasculature, are of great potential for modeling vascular-associated diseases and tissue engineering. Here, we presented a detailed comparison of differentiating human pluripotent stem cells (hPSCs) into VSMCs (hPSCs-VSMCs) in four different culture methods, including 2-dimensional (2D) culture, 3-dimensional (3D) PNIPAAm-PEG hydrogel culture, 3-dimensional (3D) alginate hydrogel culture, and transferring 3- dimensional alginate hydrogel culture to 2-dimensional (2D) culture. Both hydrogel-based culture methods could mimic in vivo microenvironment to protect cells from shear force, and avoid cells agglomeration, resulting in the extremely high culture efficiency (e.g., high viability, high purity and high yield) compared with 2D culture. We demonstrated hPSC-VSMCs produced from hydrogel-based culture methods had better contractile phenotypes and the potential of vasculature formation. The transcriptome analysis showed the hPSC-VSMCs derived from hydrogel-based culture methods displayed more upregulated genes in vasculature development, angiogenesis and blood vessel development, extracellular matrix compared with 2D culture. Taken together, hPSC-VSMCs produced from hydrogel-based culture system could be applied in various biomedical fields, and further indicated the suitable development of alginate hydrogel for industrial production by taking all aspects into consideration

The Sirtuin-2 Inhibitor AK7 Is Neuroprotective in Models of Parkinson’s Disease but Not Amyotrophic Lateral Sclerosis and Cerebral Ischemia

Sirtuin deacetylases regulate diverse cellular pathways and influence disease processes. Our previous studies identified the brain-enriched sirtuin-2 (SIRT2) deacetylase as a potential drug target to counteract neurodegeneration. In the present study, we characterize SIRT2 inhibition activity of the brain-permeable compound AK7 and examine the efficacy of this small molecule in models of Parkinson’s disease, amyotrophic lateral sclerosis and cerebral ischemia. Our results demonstrate that AK7 is neuroprotective in models of Parkinson’s disease; it ameliorates alpha-synuclein toxicity in vitro and prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopamine depletion and dopaminergic neuron loss in vivo. The compound does not show beneficial effects in mouse models of amyotrophic lateral sclerosis and cerebral ischemia. These findings underscore the specificity of protective effects observed here in models of Parkinson’s disease, and previously in Huntington’s disease, and support the development of SIRT2 inhibitors as potential therapeutics for the two neurodegenerative diseases

Comparative Study of Human Pluripotent Stem Cell-Derived Endothelial Cells in Hydrogel-Based Culture Systems

Human pluripotent stem cell (hPSC)-derived endothelial cells (ECs) are promising cell sources for drug discovery, tissue engineering, and studying or treating vascular diseases. However, hPSC-ECs derived from different culture methods display different phenotypes. Herein, we made a detailed comparative study of hPSC-ECs from three different culture systems (e.g., 2D, 3D PNIPAAm-PEG hydrogel, and 3D alginate hydrogel cultures) based on our previous reports. We expanded hPSCs and differentiated them into ECs in three culture systems. Both 3D hydrogel systems could mimic an in vivo physiologically relevant microenvironment to protect cells from shear force and prevent cell agglomeration, leading to a high culture efficiency and a high volumetric yield. We demonstrated that hPSC-ECs produced from both hydrogel systems had similar results as 2D-ECs. The transcriptome analysis showed that PEG-ECs and alginate-ECs displayed a functional phenotype due to their higher gene expressions in vasculature development, extracellular matrix, angiogenesis, and glycolysis, while 2D-ECs showed a proliferative phenotype due to their higher gene expressions in cell proliferation. Taken together, both PEG- and alginate-hydrogel systems will significantly advance the applications of hPSC-ECs in various biomedical fields

Solidification structure and high temperature oxidation resistance of nano titanium dioxide TiO2 added Inconel 718 deposits by arc melt

In order to refine the microstructure of Inconel 718 and achieve high performance, nanometer TiO _2 particles (nano-TiO _2 ) were adopted to modify the solidification structure. After pretreating nano-TiO _2 , oxide added 718 nickel alloy were prepared by using arc melting technology, and the microstructure and oxidation behavior were investigated in detail. The results show that the microstructures of Inconel 718 alloys with different content of nano-TiO _2 are all dendritic-like, and the size of dendrite gradually decreases and the shape tends to become equiaxed grain with the increase of TiO _2 content. The grain refinement effect is best for 0.6%TiO _2 added alloy. The precipitated phases become finer and more uniform due to grain refinement. The high temperature oxidation experiments of Inconel 718 alloy with different volume fractions of TiO _2 show that the main oxides are Cr _2 O _3 , accompanying with some Nb-Fe oxides. With the decrease of grain size, the size of oxides gradually decreases, and the oxidation layers are more and more compact, which effectively improves the oxidation resistance

Human neural stem cell transplantation rescues cognitive defects in APP/PS1 model of Alzheimer's disease by enhancing neuronal connectivity and metabolic activity

Alzheimer’s disease (AD), the most frequent type of dementia, is featured by Aβ pathology, neural degeneration and cognitive decline. To date, there is no cure for this disease. Neural stem cell (NSC) transplantation provides new promise for treating AD. Many studies report that intra-hippocampal transplantation of murine NSCs improved cognition in rodents with AD by alleviating neurodegeneration via neuronal complement or replacement. However, few reports examined the potential of human NSC transplantation for AD. In this study, we implanted human brain-derived NSCs (hNSCs) into bilateral hippocampus of an APP/PS1 transgenic mouse model of AD to test the effects of hNSC transplantation on Alzheimer’s behavior and neuropathology. Six weeks later, transplanted hNSCs engrafted into the brains of AD mice, migrated dispersedly in broad brain regions, and some of them differentiated into neural cell types of central nervous system. The hNSC transplantation restored the recognition, learning and memory deficits but not anxiety tasks in AD mice. Although Aβ plaques were not significantly reduced, the neuronal, synaptic and nerve fiber density was significantly increased in the frontal cortex and hippocampus of hNSC-treated AD mice, suggesting of improved neuronal connectivity in AD brains after hNSC transplantation. Ultrastructural analysis confirmed that synapses and nerve fibers maintained relatively well-structured shapes in these mice. Furthermore, in-vivo magnetic resonance spectroscopy showed that hNSC-treated mice had notably increased levels of NAA and Glu in the frontal cortex and hippocampus, suggesting that neuronal metabolic activity was improved in AD brains after hNSC transplantation. These results suggest that transplanted hNSCs rescued Alzheimer’s cognition by enhancing neuronal connectivity and metabolic activity through a compensation mechanism in APP/PS1 mice. This study provides preclinical evidence that hNSC transplantation can be a possible and feasible strategy for treating patients with AD

Comparative study of differentiating human pluripotent stem cells into vascular smooth muscle cells in hydrogel-based culture methods

Vascular smooth muscle cells (VSMCs), which provides structural integrity and regulates the diameter of vasculature, are of great potential for modeling vascular-associated diseases and tissue engineering. Here, we presented a detailed comparison of differentiating human pluripotent stem cells (hPSCs) into VSMCs (hPSCs-VSMCs) in four different culture methods, including 2-dimensional (2D) culture, 3-dimensional (3D) PNIPAAm-PEG hydrogel culture, 3-dimensional (3D) alginate hydrogel culture, and transferring 3-dimensional alginate hydrogel culture to 2-dimensional (2D) culture. Both hydrogel-based culture methods could mimic in vivo microenvironment to protect cells from shear force, and avoid cells agglomeration, resulting in the extremely high culture efficiency (e.g., high viability, high purity and high yield) compared with 2D culture. We demonstrated hPSC-VSMCs produced from hydrogel-based culture methods had better contractile phenotypes and the potential of vasculature formation. The transcriptome analysis showed the hPSC-VSMCs derived from hydrogel-based culture methods displayed more upregulated genes in vasculature development, angiogenesis and blood vessel development, extracellular matrix compared with 2D culture. Taken together, hPSC-VSMCs produced from hydrogel-based culture system could be applied in various biomedical fields, and further indicated the suitable development of alginate hydrogel for industrial production by taking all aspects into consideration

Dissociation between urate and blood pressure in mice and in people with early Parkinson's diseaseResearch in context

Background: Epidemiological, laboratory and clinical studies have established an association between elevated urate and high blood pressure (BP). However, the inference of causality remains controversial. A naturally occurring antioxidant, urate may also be neuroprotective, and urate-elevating treatment with its precursor inosine is currently under clinical development as a potential disease-modifying strategy for Parkinson's disease (PD). Methods: Our study takes advantage of a recently completed phase II trial evaluating oral inosine in de novo non-disabling early PD with no major cardiovascular and nephrological conditions, and of three lines of genetically engineered mice: urate oxidase (UOx) global knockout (gKO), conditional KO (cKO), and transgenic (Tg) mice with markedly elevated, mildly elevated, and substantially reduced serum urate, respectively, to systematically investigate effects of urate-modifying manipulation on BP. Findings: Among clinical trial participants, change in serum urate but not changes in systolic, diastolic and orthostatic BP differed by treatment group. There was no positive correlation between urate elevations and changes in systolic, diastolic and orthostatic BP ((p = .05 (in inverse direction), 0.30 and 0.63, respectively)). Between UOx gKO, cKO, or Tg mice and their respective wildtype littermates there were no significant differences in systolic or diastolic BP or in their responses to BP-regulating interventions. Interpretation: Our complementary preclinical and human studies of urate modulation in animal models and in generally healthy early PD do not support a hypertensive effect of urate elevation or an association between urate and BP. Fund: U.S. Department of Defense, RJG Foundation, Michael J. Fox Foundation LEAPS program, National Institutes of Health, American Federation for Aging Research, Parkinson's Disease Foundation Advancing Parkinson's Therapies initiative. Keywords: Urate, Hyperuricemia, Urate oxidase, Blood pressure, Hypertensio

Effects of AK7 in SOD1-G93A mouse model of ALS.

<p>Kaplan-Meier probability curves show no significant effects of AK7 treatment on (<b>A</b>) symptom onset (118 ± 10.0 days for AK7, 117 ± 8.6 days for vehicle-treated controls) or (<b>B</b>) survival (169 ± 12.7 days for AK7, 175 ± 12.4 days for controls) of SOD1-G93A mice in this study. Values are median age ± SD; n = 23 for AK7, n = 27 for vehicle-treated controls.</p

Protective effects of AK7 in acute MPTP mouse model of PD.

<p>Mice received a single injection (<i>i.p.</i>) of MPTP at 40 mg/kg or saline. AK7 30 mg/kg was injected <i>i.p.</i> 10 min before and 50 min after MPTP administration. Animals were sacrificed 7 days after the injection. Striatal DA (A) and metabolite DOPAC (B) were detected by HPLC-ECD (A&B, n = 8–10, *<i>p</i><0.05 vs CON; # <i>p</i><0.05 vs MPTP). (C) For determination of MPTP metabolism, mice were injected with MPTP and AK7 (10 min before and 50 min after MPTP) at indicated doses and sacrifice 90 min after MPTP treatment. MPP⁺ was detected in the striatum by HPLC (C, n = 5–6, ** ##, <i>p</i><0.01 vs corresponding MPTP control groups).</p