Summary Human induced pluripotent stem cells (hiPSCs) hold promise for myocardial repair following injury, but preclinical studies in large animal models are required to determine optimal cell preparation and delivery strategies to maximize functional benefits and to evaluate safety. Here, we utilized a porcine model of acute myocardial infarction (MI) to investigate the functional impact of intramyocardial transplantation of hiPSC-derived cardiomyocytes, endothelial cells, and smooth muscle cells, in combination with a 3D fibrin patch loaded with insulin growth factor (IGF)-encapsulated microspheres. hiPSC-derived cardiomyocytes integrated into host myocardium and generated organized sarcomeric structures, and endothelial and smooth muscle cells contributed to host vasculature. Tri-lineage cell transplantation significantly improved left ventricular function, myocardial metabolism, and arteriole density, while reducing infarct size, ventricular wall stress and apoptosis without inducing ventricular arrhythmias. These findings in a large animal MI model highlight the potential of utilizing hiPSC-derived cells for cardiac repair.

A bioengineered spinal cord is fabricated via extrusion-based multimaterial 3D bioprinting, in which clusters of induced pluripotent stem cell (iPSC)derived spinal neuronal progenitor cells (sNPCs) and oligodendrocyte progenitor cells (OPCs) are placed in precise positions within 3D printed biocompatible scaffolds during assembly. The location of a cluster of cells, of a single type or multiple types, is controlled using a point-dispensing printing method with a 200 µm center-to-center spacing within 150 µm wide channels. The bioprinted sNPCs differentiate and extend axons throughout microscale scaffold channels, and the activity of these neuronal networks is confirmed by physiological spontaneous calcium flux studies. Successful bioprinting of OPCs in combination with sNPCs demonstrates a multicellular neural tissue engineering approach, where the ability to direct the patterning and combination of transplanted neuronal and glial cells can be beneficial in rebuilding functional axonal connections across areas of central nervous system (CNS) tissue damage. This platform can be used to prepare novel biomimetic, hydrogel-based scaffolds modeling complex CNS tissue architecture in vitro and harnessed to develop new clinical approaches to treat neurological diseases, including spinal cord injury.

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occurs to an apolar or budding mode of growth. This is University of Idaho, Moscow, ID 83844 and 2 VADMS Center, followed by the formation of two layers of uninucleate Department Osmani, 1994).Analysis of aconidial mutants and mutants that develop The Aspergillus nidulans Stunted protein (StuAp) reguaberrant conidiophore morphology has revealed genetic lates multicellular complexity during asexual reproducinteractions required for multicellular development tion by moderating the core developmental program (Clutterbuck, 1969; Martinelli and Clutterbuck, 1971). that directs differentiation of uninucleate, terminally bristle (brlA) null mutants fail to differentiate beyond the differentiated spores from multinucleate, vegetative formation of aerial hyphae. abacus (abaA) mutants do not hyphae. StuAp is also required for ascosporogenesis complete terminal differentiation to form conidia but and multicellular development during sexual reproducdevelop chains of reiterating phialide-like cells. brlA and tion. StuAp is a member of a family of fungal transcripabaA encode transcription factors that form a linear tion factors that regulate development or cell cycle pathway activating expression of many sporulationprogression. Further, StuAp characterizes a sub-family specific genes (Boylan et al., 1987;Adams et al., 1988; possessing the conserved APSES domain. We demon- Mirabito et al., 1989). A brlA-abaA positive feedback strate for the first time that the APSES domain is a regulatory loop promotes conidiation. Morphological sequence-specific DNA-binding domain that can be modifiers encoded by stunted (stuA) and medusa (medA) modeled as a basic helix-loop-helix (bHLH)-like modulate expression of the BrlAp-AbaAp pathway. stuA structure. We have found that StuAp response elements and medA null mutants exhibit dramatically altered ( A / T CGCG T / A N A / C ) are located upstream of both conidiophore complexity but conidia formation is not critical developmental regulatory genes and cell cycle prohibited (Miller et al., 1992;Busby et al., 1996). genes in A.nidulans. StuAp is shown to act as aThe Stunted protein (StuAp) is an important regulator transcriptional repressor in A.nidulans, but as a weak of multicellular development in A.nidulans. stuA null activator in budding yeast. Our data suggest that mutants form aerial hyphae that are much shorter than the differentiation of pseudohyphal-like sterigmatal those of the wild-type. Reduced conidiophores lack the cells during multicellular conidiophore development uninuclear cell types, the metulae and phialides. Limited requires correct StuAp-regulated expression of both numbers of single, abnormally shaped spores differentiate developmental and cell cycle genes in A.nidulans.

Age-related macular degeneration (AMD) is the leading cause of blindness among older adults. It has been suggested that mitochondrial defects in the retinal pigment epithelium (RPE) underlies AMD pathology. To test this idea, we developed primary cultures of RPE to ask whether RPE from donors with AMD differ in their metabolic profile compared with healthy age-matched donors. Analysis of gene expression, protein content, and RPE function showed that these cultured cells replicated many of the cardinal features of RPE in vivo. Using the Seahorse Extracellular Flux Analyzer to measure bioenergetics, we observed RPE from donors with AMD exhibited reduced mitochondrial and glycolytic function compared with healthy donors. RPE from AMD donors were also more resistant to oxidative inactivation of these two energy-producing pathways and were less susceptible to oxidation-induced cell death compared with cells from healthy donors. Investigation of the potential mechanism responsible for differences in bioenergetics and resistance to oxidative stress showed RPE from AMD donors had increased PGC1α protein as well as differential expression of multiple genes in response to an oxidative challenge. Based on our data, we propose that cultured RPE from donors phenotyped for the presence or absence of AMD provides an excellent model system for studying “AMD in a dish”. Our results are consistent with the ideas that (i) a bioenergetics crisis in the RPE contributes to AMD pathology, and (ii) the diseased environment in vivo causes changes in the cellular profile that are retained in vitro.