Spectral unmixing of multi-color tissue specific in vivo fluorescence in mice

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

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Caenorhabditis elegans Junctophilin has tissue-specific functions and regulates neurotransmission with extended-synaptotagmin

Genetics ◽

10.1093/genetics/iyab063 ◽

2021 ◽

Author(s):

Christopher A Piggott ◽

Zilu Wu ◽

Stephen Nurrish ◽

Suhong Xu ◽

Joshua M Kaplan ◽

...

Keyword(s):

Calcium Channels ◽

Calcium Channel ◽

Tissue Specific ◽

Voltage Gated ◽

Membrane Contact Sites ◽

Contact Sites ◽

Pharyngeal Muscles ◽

Membrane Contact ◽

Null Mutants

Abstract The junctophilin family of proteins tether together plasma membrane (PM) and endoplasmic reticulum (ER) membranes, and couple PM- and ER-localized calcium channels. Understanding in vivo functions of junctophilins is of great interest for dissecting the physiological roles of ER-PM contact sites. Here, we show that the sole C. elegans junctophilin JPH-1 localizes to discrete membrane contact sites in neurons and muscles and has important tissue-specific functions. jph-1 null mutants display slow growth and development due to weaker contraction of pharyngeal muscles, leading to reduced feeding. In the body wall muscle, JPH-1 co-localizes with the PM-localized EGL-19 voltage-gated calcium channel and ER-localized UNC-68/RyR calcium channel, and is required for animal movement. In neurons, JPH-1 co-localizes with the membrane contact site protein Extended-SYnaptoTagmin 2 (ESYT-2) in soma, and is present near presynaptic release sites. Interestingly, jph-1 and esyt-2 null mutants display mutual suppression in their response to aldicarb, suggesting that JPH-1 and ESYT-2 have antagonistic roles in neuromuscular synaptic transmission. Additionally, we find an unexpected cell non-autonomous effect of jph-1 in axon regrowth after injury. Genetic double mutant analysis suggests that jph-1 functions in overlapping pathways with two PM-localized voltage-gated calcium channels, egl-19 and unc-2, and unc-68/RyR for animal health and development. Finally, we show that jph-1 regulates the colocalization of EGL-19 and UNC-68 and that unc-68/RyR is required for JPH-1 localization to ER-PM puncta. Our data demonstrate important roles for junctophilin in cellular physiology, and also provide insights into how junctophilin functions together with other calcium channels in vivo.

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The Radiation-Induced Regenerative Response of Adult Tissue-Specific Stem Cells: Models and Signaling Pathways

Cancers ◽

10.3390/cancers13040855 ◽

2021 ◽

Vol 13 (4) ◽

pp. 855

Author(s):

Paola Serrano Martinez ◽

Lorena Giuranno ◽

Marc Vooijs ◽

Robert P. Coppes

Keyword(s):

Signaling Pathways ◽

Progenitor Cells ◽

Tissue Regeneration ◽

Normal Tissue ◽

Cellular Response ◽

Adult Tissue ◽

Tissue Specific ◽

Radiation Induced

Radiotherapy is involved in the treatment of many cancers, but damage induced to the surrounding normal tissue is often inevitable. Evidence suggests that the maintenance of homeostasis and regeneration of the normal tissue is driven by specific adult tissue stem/progenitor cells. These tasks involve the input from several signaling pathways. Irradiation also targets these stem/progenitor cells, triggering a cellular response aimed at achieving tissue regeneration. Here we discuss the currently used in vitro and in vivo models and the involved specific tissue stem/progenitor cell signaling pathways to study the response to irradiation. The combination of the use of complex in vitro models that offer high in vivo resemblance and lineage tracing models, which address organ complexity constitute potential tools for the study of the stem/progenitor cellular response post-irradiation. The Notch, Wnt, Hippo, Hedgehog, and autophagy signaling pathways have been found as crucial for driving stem/progenitor radiation-induced tissue regeneration. We review how these signaling pathways drive the response of solid tissue-specific stem/progenitor cells to radiotherapy and the used models to address this.

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