Scanning X-ray diffraction on cardiac tissue: automatized data analysis and processing

Abstract

A scanning X-ray diffraction study of cardiac tissue has been performed, covering the entire cross section of a mouse heart slice. To this end, moderate focusing by compound refractive lenses to micrometer spot size, continuous scanning, data acquisition by a fast single-photon-counting pixel detector, and fully automated analysis scripts have been combined. It was shown that a surprising amount of structural data can be harvested from such a scan, evaluating the local scattering intensity, interfilament spacing of the muscle tissue, the filament orientation, and the degree of anisotropy. The workflow of data analysis is described and a data analysis toolbox with example data for general use is provided. Since many cardiomyopathies rely on the structural integrity of the sarcomere, the contractile unit of cardiac muscle cells, the present study can be easily extended to characterize tissue from a diseased heart.

Radiation damage studies in cardiac muscle cells and tissue using microfocused X-ray beams: experiment and simulation

“…A beamstop is used to block the primary (unscattered) beam. (B) Map of the integrated intensity of a tissue section described in detail byNicolas et al (2017a). (C) Scan parameters that can be varied to minimize the detrimental effect of radiation damage.…”

Multiscale X-Ray Analysis of Biological Cells and Tissues by Scanning Diffraction and Coherent Imaging

“…It is widely considered that protein crystallography has been the driving force in the development of synchrotron radiation. However, the first beamline installed at a synchrotron was not built to determine the structure of organic compounds or proteins, but to understand in greater detail the mechanism of muscle contraction [1]. What happens when muscle actively contracts?…”

“…1.1(D). The interfilament spacing d (1,0) typically ranges between 35.0 nm and 38.3 nm for intact rat myocardium. We have published a more extensive list with literature references online (https://irpgoe.github.io/nanodiffraction/ ).…”

“…The myosin and actin reflections as well as the (1,0) and (1,1) equatorial reflections are shown in Fig. 1.1(F).…”

The Dual Functional Reflecting Iris of the Zebrafish

“…Thus, a single scan could contain over 400 000 diffraction patterns, covering the entire surface area of the iris at an overall scan time of about 1 h per sample. To analyze the data in a standardized, robust, and model‐independent fashion, we used a custom Matlab‐based principal component analysis (PCA) based on Bernhardt et al as part of a Nano‐diffraction toolbox described by Nicolas et al (Supporting Information). Using this PCA algorithm, we extracted the anisotropy and orientation of light scattering and, subsequently, inferred the orientation of the crystals.…”