Based on experimental data, we introduce and analyze a system of reaction-diffusion equations for the regeneration of planarian flatworms. We model dynamics of head and tail cells expressing positional control genes that translate into localized signals which in turn guide stem cell differentiation. Tissue orientation and positional information are encoded in a long range wnt-related signaling gradient. Our system correctly reproduces typical cut and graft experiments, and improves on previous models by preserving polarity in regeneration over orders of magnitude in body size during growth phases. Key to polarity preservation in our model flatworm is the sensitivity of cell differentiation to gradients of wnt-related signals relative to the tissue surface. This process is particularly relevant in small tissue layers close to cuts during their healing, and modeled in a robust fashion through dynamic boundary conditions.
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http://dx.doi.org/10.1007/s00285-021-01627-w | DOI Listing |
Cell Rep
January 2025
Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address:
Chromatin regulatory proteins are expressed broadly and assumed to exert the same intrinsic function across cell types. Here, we report that 14 chromatin regulators undergo evolutionary-conserved neuron-specific splicing events involving microexons. Among them are two components of a histone demethylase complex: LSD1 H3K4 demethylase and the H3K4me0-reader PHF21A.
View Article and Find Full Text PDFJ Physiol
January 2025
Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
Here we characterize seven Cx30.3 gene variants (R22H, S26Y, P61R, C86S, E99K, T130M and M190L) clinically associated with the rare skin disorder erythrokeratodermia variabilis et progressiva (EKVP) in tissue-relevant and differentiation-competent rat epidermal keratinocytes (REKs). We found that all variants, when expressed alone or together with wildtype (WT) Cx30.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China.
Nanoplastics (NPs) are ubiquitous in the environment, posing significant threats to biological systems, including nervous systems, across various trophic levels. Nevertheless, the molecular mechanisms behind the size-dependent neurotoxicity of NPs remain unclear. Here, we investigated the neurotoxicity of 20 and 100 nm polystyrene NPs (PS-NPs) to zebrafish.
View Article and Find Full Text PDFDevelopment
January 2025
Institute of Molecular Biology, Hannover Medical School, 30625 Hannover, Germany.
In the mammalian ureters, the lamina propria presents as a prominent layer of connective tissue underneath the urothelium. Despite its important structural and signaling functions, little is known how the lamina propria develops. Here, we show that in the murine ureter, the lamina propria arises at late fetal stages and massively increases by fibrocyte proliferation and collagen deposition after birth.
View Article and Find Full Text PDFImmunol Invest
January 2025
Department of Respiratory Medicine, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin, China.
Introduction: T helper 17 (Th17) cells have a significant effect in the pathogenesis of asthma, and signal transducer and activator of transcription 3 (STAT3) pathway activation is critical for Th17 cell differentiation. Timosaponin A-III (TA3) was reported to inhibit the STAT3 pathway. Here, we investigated whether TA3 improved asthma by inhibiting the STAT3 pathway.
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