correlative-super-resolution-electron-microscopy-to-resolve-protein

Correlative Super-resolution and Electron Microscopy to Resolve Protein Localization in Zebrafish Retina

We present a method to investigate the subcellular protein localization in the larval zebrafish retina by combining super-resolution light microscopy and ...

University of Zurich

A dietary potassium load induces a rapid kaliuresis and natriuresis, which may occur even before plasma potassium and aldosterone (aldo) levels increase. Here we sought to gain insight into underlying molecular mechanisms contributing to this response. After gastric gavage of 2% potassium, the plasma potassium concentrations rose rapidly (0.25 h), followed by a significant rise of plasma aldo (0.5 h) in mice. Enhanced urinary potassium and sodium excretion was detectable as early as spot urines could be collected (about 0.5 h). The functional changes were accompanied by a rapid and sustained (0.25-6 h) dephosphorylation of the NaCl cotransporter (NCC) and a late (6 h) upregulation of proteolytically activated epithelial sodium channels. The rapid effects on NCC were independent from the coadministered anion. NCC dephosphorylation was also aldo-independent, as indicated by experiments in aldo-deficient mice. The observed urinary sodium loss relates to NCC, as it was markedly diminished in NCC-deficient mice. Thus, downregulation of NCC likely explains the natriuretic effect of an acute oral potassium load in mice. This may improve renal potassium excretion by increasing the amount of intraluminal sodium that can be exchanged against potassium in the aldo-sensitive distal nephron.

Rapid dephosphorylation of the renal sodium chloride cotransporter in response to oral potassium intake in mice.

The aim of this study was to determine whether remote ischemic preconditioning (RIPC) protects aged liver against ischemia reperfusion (IR).

Remote Ischemic Preconditioning: A Novel Strategy in Rescuing Older Livers From Ischemia-reperfusion Injury in a Rodent Model.

Fluorescence microscopy reveals molecular expression at nanometer resolution but lacks ultrastructural context information. This deficit often hinders a clear interpretation of results. Electron microscopy provides this contextual subcellular detail, but protein identification can often be problematic. Correlative light and electron microscopy produces complimentary information that expands our knowledge of protein expression in cells and tissue. Inherent methodological difficulties are however encountered when combining these two very different microscopy technologies. We present a quick, simple and reproducible method for protein localization by conventional and super-resolution light microscopy combined with platinum shadowing and scanning electron microscopy to obtain topographic contrast from the surface of ultrathin cryo-sections. We demonstrate protein distribution at nuclear pores and at mitochondrial and plasma membranes in the extended topographical landscape of tissue.

Topographic contrast of ultrathin cryo-sections for correlative super-resolution light and electron microscopy.

The pollen tube (PT) serves as a model system for investigating plant cell growth and morphogenesis. Ultrastructural studies are indispensable to complement data from physiological and genetic analyses, yet an effective method is lacking for PTs of the model plant Arabidopsis thaliana.

Article	Year
Rapid dephosphorylation of the renal sodium chloride cotransporter in response to oral potassium intake in mice. Kidney international\| PubMed ID: 23447069	2013
Remote Ischemic Preconditioning: A Novel Strategy in Rescuing Older Livers From Ischemia-reperfusion Injury in a Rodent Model. Annals of surgery\| PubMed ID: 27584570	2016
Topographic contrast of ultrathin cryo-sections for correlative super-resolution light and electron microscopy. Scientific reports\| PubMed ID: 27666401	2016
Efficient preparation of Arabidopsis pollen tubes for ultrastructural analysis using chemical and cryo-fixation. BMC plant biology\| PubMed ID: 29078752	2017

Gery Barmettler

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