Seeing is believing: multi-scale spatio-temporal imaging towards in vivo cell biology

Abstract

Life is driven by a set of biological events that are naturally dynamic and tightly orchestrated from the single molecule to entire organisms. Although biochemistry and molecular biology have been essential in deciphering signaling at a cellular and organismal level, biological imaging has been instrumental for unraveling life processes across multiple scales. Imaging methods have considerably improved over the past decades and now allow to grasp the inner workings of proteins, organelles, cells, organs and whole organisms. Not only do they allow us to visualize these events in their most-relevant context but also to accurately quantify underlying biomechanical features and, so, provide essential information for their understanding. In this Commentary, we review a palette of imaging (and biophysical) methods that are available to the scientific community for elucidating a wide array of biological events. We cover the most-recent developments in intravital imaging, light-sheet microscopy, superresolution imaging, and correlative light and electron microscopy. In addition, we illustrate how these technologies have led to important insights in cell biology, from the molecular to the whole-organism resolution. Altogether, this review offers a snapshot of the current and state-of-the-art imaging methods that will contribute to the understanding of life and disease.

Intravital microscopy of biosensor activities and intrinsic metabolic states

“…This is critical, since cellular pathologies develop while integrated within the complex tissue environment in vivo . To examine the origins of pathologies it is necessary to study them in the setting of the full cellular organization, ideally in 3D and in real-time, inside the living animal [40]. However, imaging in highly scattering biological tissue presents substantial challenges to the quantitative analysis of the optical signals.…”

Molecular mobility and activity in an intravital imaging setting – implications for cancer progression and targeting

“…New multimodal imaging approaches whereby IVM is combined with electron microscopy, such as intravital correlative light and electron microscopy (CLEM) can help to reveal ultrastructural details of cells and ECM. The coupling of IVM in live tissue and electron microscopy in fixed tissue imposes several challenges on the user, including tissue fixation or retrieving the IVM region of interest (ROI) in the EM sample (discussed in more detail in de Boer et al, 2015;Follain et al, 2017;Karreman et al, 2016a). For example, near-infrared branding (NIRB) was used to permanently label intravital ROIs and to precisely localise them in the EM sample.…”

“…This is essential for imaging thick samples, without the need for a confocal pinhole, thereby reducing the effect of sample aberration on the image quality relative to confocal microscopy. The relative advantages of different microscope platforms are discussed in detail elsewhere (Follain et al, 2017;Pantazis and Supatto, 2014;Timpson et al, 2011).…”

Unraveling the host's immune response to infection: Seeing is believing

“…). Murine models are the most commonly used and well established for IVM; however, many species are amenable to this approach . In this review, we will discuss the recent discoveries IVM has brought forth to the world of host‐pathogen interactions, specifically focusing on the innate immune system's response to bacterial infection.…”