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Background: Post‐translational histone modifications are among the most common epigenetic modifications that orchestrate gene expression, playing a pivotal role during embryonic development and in various pathological conditions. Among histone lysine demethylases, KDM7A, also known as KIAA1718 or JHDM1D, catalyzes the demethylation of H3K9me1/2 and H3K27me1/2, leading to transcriptional regulation. Previous data suggest that KDM7A plays a central role in several biological processes, including cell proliferation, commitment, differentiation, apoptosis, and maintenance. However, information on the expression pattern of KDM7A in whole organisms is limited, and its functional role is still unclear. Results: In Xenopus development, kdm7a is expressed early, undergoing spatiotemporal regulation in various organs and tissues, including the central nervous system and the eye. Focusing on retinal development, we found that kdm7a overexpression does not affect the expression of genes critically involved in early neural development and eye‐field specification, whereas unbalances the distribution of neural cell subtypes in the mature retina by disfavoring the development of ganglion cells while promoting that of horizontal cells. Conclusions: Kdm7a is dynamically expressed during embryonic development, and its overexpression influences late retinal development, suggesting a potential involvement in the molecular machinery regulating the spatiotemporally ordered generation of retinal neuronal subtypes. Key Findings: Histone methylation are among the most common epigenetic modifications that orchestrate gene expression.Although the histone demethylases kdm7a has been involved in various biological processes, data about its expression pattern and functional role during embryogenesis are still limited.Herein, we analyze the spatio‐temporal expression pattern of kdm7a in Xenopus laevis development and found that kdm7a overexpression specifically affects retinogenesis by disfavouring the development of ganglion cells while promoting that of horizontal cells. [ABSTRACT FROM AUTHOR]

All biomaterials initiate a tissue response when implanted in living tissues. Ultimately this reaction causes fibrous encapsulation and hence isolation of the material, leading to failure of the intended therapeutic effect of the implant. There has been extensive bioengineering research aimed at overcoming or delaying the onset of encapsulation. Nanotechnology has the potential to address this problem by virtue of the ability of some nanomaterials to modulate interactions with cells, thereby inducing specific biological responses to implanted foreign materials. To this effect in the present study, we have characterised the growth of fibroblasts on nano-structured sheets constituted by BaTiO3, a material extensively used in biomedical applications. We found that sheets of vertically aligned BaTiO3 nanotubes inhibit cell cycle progression - without impairing cell viability - of NIH-3T3 fibroblast cells. We postulate that the 3D organization of the material surface acts by increasing the availability of adhesion sites, promoting cell attachment and inhibition of cell proliferation. This finding could be of relevance for biomedical applications designed to prevent or minimize fibrous encasement by uncontrolled proliferation of fibroblastic cells with loss of material-tissue interface underpinning long-term function of implants. [ABSTRACT FROM AUTHOR]

The tRNA-histidine guanylyltransferase 1-like ( THG1L ), also known as induced in high glucose-1 ( IHG-1 ), encodes for an essential mitochondria-associated protein highly conserved throughout evolution, that catalyses the 3'-5' addition of a guanine to the 5'-end of tRNA-histidine (tRNA His ). Previous data indicated that THG1L plays a crucial role in the regulation of mitochondrial biogenesis and dynamics, in ATP production, and is critically involved in the modulation of apoptosis, cell-cycle progression and survival, as well as in cellular stress responses and redox homeostasis. Dysregulations of THG1L expression play a central role in various pathologies, including nephropathies, and neurodevelopmental disorders often characterized by developmental delay and cerebellar ataxia. Despite the essential role of THG1L, little is known about its expression during vertebrate development. Herein, we examined the detailed spatio-temporal expression of this gene in the developing Xenopus laevis . Our results show that thg1l is maternally inherited and its temporal expression suggests a role during the earliest stages of embryogenesis. Spatially, thg1l mRNA localizes in the ectoderm and marginal zone mesoderm during early stages of development. Then, at tadpole stages, thg1l transcripts mostly localise in neural crests and their derivatives, somites, developing kidney and central nervous system, therefore largely coinciding with territories displaying intense energy metabolism during organogenesis in Xenopus .

The 3-D spatial and mechanical features of nano-topography can create alternative environments, which influence cellular response. In this paper, murine fibroblast cells were grown on surfaces characterized by protruding nanotubes. Cells cultured on such nano-structured surface exhibit stronger cellular adhesion compared to control groups, but despite the fact that stronger adhesion is generally believed to promote cell cycle progression, the time cells spend in G1 phase is doubled. This apparent contradiction is solved by confocal microscopy analysis, which shows that the nano-topography inhibits actin stress fiber formation. In turn, this impairs RhoA activation, which is required to suppress the inhibition of cell cycle progression imposed by p21/p27. This finding suggests that the generation of stress fibers, required to impose the homeostatic intracellular tension, rather than cell adhesion/spreading is the limiting factor for cell cycle progression. Indeed, nano-topography could represent a unique tool to inhibit proliferation in adherent well-spread cells., (Copyright © 2018 Elsevier Inc. All rights reserved.)