Multiple Recurrent De Novo CNVs, Including Duplications of the 7q11.23 Williams Syndrome Region, Are Strongly Associated with Autism

SummaryWe have undertaken a genome-wide analysis of rare copy-number variation (CNV) in 1124 autism spectrum disorder (ASD) families, each comprised of a single proband, unaffected parents, and, in most kindreds, an unaffected sibling. We find significant association of ASD with de novo duplications of 7q11.23, where the reciprocal deletion causes Williams-Beuren syndrome, characterized by a highly social personality. We identify rare recurrent de novo CNVs at five additional regions, including 16p13.2 (encompassing genes USP7 and C16orf72) and Cadherin 13, and implement a rigorous approach to evaluating the statistical significance of these observations. Overall, large de novo CNVs, particularly those encompassing multiple genes, confer substantial risks (OR = 5.6; CI = 2.6–12.0, p = 2.4 × 10-7). We estimate there are 130–234 ASD-related CNV regions in the human genome and present compelling evidence, based on cumulative data, for association of rare de novo events at 7q11.23, 15q11.2-13.1, 16p11.2, and Neurexin 1

Co-cultured Mesenchymal Stem Cell Differentiation on 3D Printed Scaffolds for Bone Tissue Engineering

Mesenchymal stem cells (MSCs) have a great potential in the field of tissue engineering and regenerative medicine due to their ability to self-renew and differentiate into various lineages. They can be differentiated by chemical factors, mechanical stimulus, and electrical potential among others. However, one of the strategies to enhance osteogenic differentiation of MSCs is to co-culture them with endothelial cells (ECs) exploiting their cell-cell interactions. In addition to differentiating into osteogenic, adipogenic and chondrogenic lineages, MSCs can differentiate into endothelial phenotype in vivo behavior can be reflected more accurately by a three-dimensional (3D) scaffold environment than a two-dimensional (2D) planar surface. Hence, 3D bioprinting can be used to provide a new opportunity for stem cell distribution, positioning, and differentiation at the microscale to make the differentiated architecture of any tissue while maintaining precision and control over the cellular microenvironment

Regional Differentiation of Adipose-Derived Stem Cells Proves the Role of Constant Electric Potential in Enhancing Bone Healing

Mesenchymal stem cells (MSCs) have a great potential in the field of tissue engineering and regenerative medicine on account of their ability to self-renew and differentiate into various lineages. MSCs could be differentiated by a number of ways. Electric field is known to bring about differentiation, migration, proliferation, and reorientation of MSCs. Hence, we aim to create a bioreactor to attain osteodifferentiation of human-derived MSCs in the presence of osteoinduction medium (OIM) in combination with or without alternating current (AC) fields. A stimulation bioreactor was specially designed for the exposure of adipose-derived stem cells (ASCs) to an electric field of 20 mV/cm, 60 kHz. The electric field potential (E) within the chamber was simulated using COMSOL. The morphology, proliferation, and osteogenic differentiation of ASCs under the influence of electrical stimulation were studied. By week three, electrically stimulated ASCs exhibited their typical spindle-shaped morphology. Stimulated ASCs were more intensely stained with alkaline phosphatase and alizarin red, the markers of osteogenic differentiation, as compared to the unstimulated control groups. Darker stained regions correlated with the COMSOL simulation which showed constant electric potential at the same place. The results depicted a clear difference between the effect of constant and varying electric potential on osteodifferentiation of ASCs. Picogreen assay revealed lower DNA contents of electrically stimulated ASCs compared to the control group. In this study, we have additively enhanced the osteodifferentiation potential of ASCs by electrical stimulation and have proved that it is constant electric field potential which specifically augments osteogenic differentiation. We have successfully developed a bioreactor to improve the osteodifferentiation of ASCs by an electrical field, which could be applied in regenerative therapy strategies of bone fracture treatment

Effect of Patterned Electrospun Hierarchical Structures on Alignment and Differentiation of Mesenchymal Stem Cells: Biomimicking Bone

Considering the complex hierarchical structure of bone, biomimicking the micro and nano level features should be an integral part of scaffold fabrication for successful bone regeneration. We aim to biomimic the micro- and nano-structure of bone and study the effect of physical cues on cell alignment, proliferation and differentiation. To achieve this, we have divided the scaffolds into groups: electrospun SU-8 nanofibers, electrospun SU-8 nanofibers with UV treatment and micropatterned (20 μm sized ridges and grooves) SU-8 nanofibers by photolithography with UV treatment. Two types of culture conditions were applied: with and without osteoinduction medium. In-vitro cell proliferation assays, protein estimation, ALP osteodifferentiation assay, live dead assay and cell alignment studies were performed on these micro-patterned nanofiber domains. Our findings show that patterned surface induced an early osteodifferentiation of MSCs even in absence of osteoinduction medium. An interesting similarity with the helicoidal plywood model of the bone was observed. The cells showed layering and rotation along the patterns with time. This resembles the in-vivo anisotropic multi-lamellar bone tissue architecture thus, closely mimicking the sub-cellular features of bone. This might serve as a smart biomaterial surface for MSC differentiation in therapeutics where the addition of external chemical factors is a challenge