Mouse retinal progenitor cell (RPC) cocultivation with retinal pigment epithelial cell culture affects features of RPC differentiation

We provide evidence that coculturing of retinal progenitor cells (RPC) with retinal pigment epithelial cells significantly biases the standard in vitro RPC differentiation patterns. In particular, in cocultivation experiments RPCs lost the ability to differentiate spontaneously and displayed approximately 2.1-2.4-fold increase in immunoreactivity to the neural stem cell marker nestin and approximately 1.6-1.7-fold increase in rod photoreceptor cell rhodopsin marker immunoreactivity. The data suggest the influence of the intercellular interaction networks on RPC differentiation.     

Using single‐cell genomics to understand developmental processes and cell fate decisions

High‐throughput ‐omics techniques have revolutionised biology, allowing for thorough and unbiased characterisation of the molecular states of biological systems. However, cellular decision‐making is inherently a unicellular process to which “bulk” ‐omics techniques are poorly suited, as they capture ensemble averages of cell states. Recently developed single‐cell methods bridge this gap, allowing high‐throughput molecular surveys of individual cells. In this review, we cover core concepts of analysis of single‐cell gene expression data and highlight areas of developmental biology where single‐cell techniques have made important contributions. These include understanding of cell‐to‐cell heterogeneity, the tracing of differentiation pathways, quantification of gene expression from specific alleles, and the future directions of cell lineage tracing and spatial gene expression analysis.     

The biological function of a fragment of the neurotrophic factor from pigment epithelium: Structural and functional homology with the differentiation factor of the HL-60 cell line

It was shown that the full-size neurotrophic factor from pigment epithelium (PEDF) induces the cell differentiation of the human promyelocyte leukemia cell line HL-60. A structural analysis of PEDF revealed in itsC-terminal region a six-membered peptide fragment PEDF-(352-357) (PEDF-6) whose sequence is highly homologous to the 41–46 fragment of the active site of the human leukocyte differentiation factor HLDF (HLDF-6). The biological effect of PEDF and synthetic peptides PEDF-6 and HLDF-6 on the HL-60 cells and the early gastrula ectoderm ofXenopus laevis embryos was studied. On the basis of the structural and functional homologies of HLDF, PEDF, and their homologous peptides and the computer models of the spatial structures of the full-size PEDF and the PEDF with theC-terminal fragment split off tby the cleavage of the Leu³⁸⁰-Thr³⁸¹ bond in the serpin loop, a hypothesis on the functional role of the serpin loop in PEDF was put forward.     

Neurotrophin-4/5 (NT-4/5) increases adult rat retinal ganglion cell survival and neurite outgrowth in vitro

Retinal ganglion cell (RGC) survival and neurite outgrowth were investigated in retinal explants from adult rats. Neutrotrophin-4/5 (NT-4/5) caused dose-dependent increases in neurite outgrowth with one-half maximal effects at approximately 0.5 ng/ml and maximal effects at 5 ng/ml. In explants treated for 7 days, the actions of NT-4/5 were similar to those of brain-derived neurotrophic factor (BDNF); with either neurotrophin, nearly twice as many RGCs survived and there was a two- to threefold increase in the number of neurites formed by RGCs. Combinations of saturating concentrations of NT-4/5 and BDNF did not enhance these in vitro effects, implying that both neurotrophins share a common signaling pathway. In contrast, nerve growth factor (NGF), neurotrophin-3 (NT-3), or ciliary nuerotrophic factor (CNTF) appeared to exert minimal influences on RGC survival or neurite outgrowth. 1994 John Wiley & Sons, Inc.