Discoveries In Cell Biology Research Articles

RaMALDI: Enabling simultaneous Raman and MALDI imaging of the same tissue section

Multimodal tissue imaging techniques that integrate two complementary modalities are powerful discovery tools for unraveling biological processes and identifying biomarkers of disease. Combining Raman spectroscopic imaging (RSI) and matrix-assisted laser-desorption/ionization (MALDI) mass spectrometry imaging (MSI) to obtain fused images with the advantages of both modalities has the potential of providing spatially resolved, sensitive, specific biomolecular information, but has so far involved two separate sample preparations, or even consecutive tissue sections for RSI and MALDI MSI, resulting in images with inherent disparities. We have developed RaMALDI, a streamlined, integrated, multimodal imaging workflow of RSI and MALDI MSI, performed on a single tissue section with one sample preparation protocol. We show that RaMALDI imaging of various tissues effectively integrates molecular information acquired from both RSI and MALDI MSI of the same sample, which will drive discoveries in cell biology, biomedicine, and pathology, and advance tissue diagnostics.

Towards an unbiased shape classification of super-resolution microscopy localizations.

Single molecule localization microscopy (SMLM) captures biological structures at nanoscale spatial resolution and has become an important tool for discovery in cell biology in recent years. However, tools that enable robust quantification of complex biological structures have lagged behind. In this study, we developed a new method to quantitatively describe and classify a wide range of diverse biological structures in SMLM data and have applied it to describe the degradation process of neuronal Tau protein aggregates, an important precursor in neurodegenerative diseases.

Super resolution live imaging: The key for unveiling the true dynamics of membrane traffic around the Golgi apparatus in plant cells.

In contrast to the relatively static image of the plants, the world inside each cell is surprisingly dynamic. Membrane-bounded organelles move actively on the cytoskeletons and exchange materials by vesicles, tubules, or direct contact between each other. In order to understand what is happening during those events, it is essential to visualize the working components in vivo. After the breakthrough made by the application of fluorescent proteins, the development of light microscopy enabled many discoveries in cell biology, including those about the membrane traffic in plant cells. Especially, super-resolution microscopy, which is becoming more and more accessible, is now one of the most powerful techniques. However, although the spatial resolution has improved a lot, there are still some difficulties in terms of the temporal resolution, which is also a crucial parameter for the visualization of the living nature of the intracellular structures. In this review, we will introduce the super resolution microscopy developed especially for live-cell imaging with high temporal resolution, and show some examples that were made by this tool in plant membrane research.

The path to condensates—19th Wiley Prize in Biomedical Sciences laureates share their discovery stories

AbstractPreface by Prof. Titia de Lange, Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, NY 10065, USAThe 19th Annual Wiley Prize in Biomedical Sciences celebrated a breakthrough in cell biology: how membrane‐less cellular compartments are formed. The existence of membrane‐less organelles, often called bodies or puncta, has been known for a long time, but what exactly they represented and how they were formed was not known. This problem was solved by a physicist, Clifford Brangwynne, a cell biologist, Anthony Hyman, and a chemist, Michael Rosen. Each, synergistically, made groundbreaking contributions to the discovery that membrane‐less organelles are liquid–liquid phase‐separated entities. The two independent discoveries leading to the principle that multivalent low‐affinity interactions between selected sets of macromolecules, some containing intrinsically disordered regions, formed a molecular condensate with unique dynamic properties, gave birth to the large, blossoming field of biomolecular condensates. The implications of those findings have influenced almost all further research of intracellular processes, including RAS signaling, immune synapses, DNA repair, transcriptional activation, and the functions of nuclear pores, the nucleolus and centrosomes. In this perspective article, the laureates of the award take us on their personal and professional trip that led to their scientific discoveries. Their stories are a celebration of the interdisciplinary essence of Natural Sciences and the potential unlocked when scientists from different fields work together to solve mysteries.

Light and Scanning Electron Microscopy of Red Blood Cells From Humans and Animal Species Providing Insights into Molecular Cell Biology.

We reviewed the many discoveries in cell biology, made since the 17th century, which have been based on red blood cells (RBCs). The advances in molecular and structural biology in the past 40 years have enabled the discovery with these cells, most notably, of the first water channel protein (WCP) called today aquaporin1 (AQP1). The main aim of our work reviewed was to examine by light and electron microscopy a very wide range of RBCs from reptiles, birds, monotremes, marsupials and placentals, in order to estimate from these images the RBC cell volume and surface area. The diffusional water permeability of the RBC membrane from these species has further been measured with a nuclear magnetic resonance (NMR) spectroscopy technique. The significance of the observed permeability of RBCs to water and possible influences on the whole body are discussed.

10 STARTUPS TO WATCH 2021: Early-stage companies advance precision medicine by applying AI, clinical genomics, and other new technologies

10 STARTUPS TO WATCH 2021: Early-stage companies advance precision medicine by applying AI, clinical genomics, and other new technologies

(Poly-cyanoacrylate) nanomedicines for cancer and beyond: Lessons learned

This « Magnum Opus » emphasizes that serendipity is a corner stone in research. The paths of discovery and innovation often result from the interdisciplinarity of scientific areas that are a priori disconnected from each other. In the 1970s, fundamental discoveries in cell biology led to unexpected advances in galenic pharmacy with the emergence of nanotechnologies for the intracellular delivery of non diffusing molecules. As well, fluorescein-loaded polyacrylamide nanocapsules were shown to deliver this fluorescent agent precisely into cellular lysosomes which represented a seminal observation. However, due to the lack of biodegradability of this carrier polymer, this approach was still far from therapeutic application. The use of cyanoacrylates as surgical glue inspired us to use this material in the design of the first biodegradable nanoparticles for human use. Capable of transporting compounds with anti-tumor activity, these polyalkylcyanoacrylate nanoparticles demonstrated the unexpected property of overcoming multi-drug resistance. This discovery led to the development of a nanomedicine that has completed phase III clinical trials for the treatment of resistant hepatocarcinoma. Going beyond the state-of-the art, a step ahead in the nanomedicine field was the drug « squalenoylation » technology, which represents a shift from the « physical » to the « chemical » encapsulation paradigm. The bioconjugation of anticancer and other drugs to squalene, a natural and biocompatible lipid, enabled a dramatic increase in drug payload, and eliminated the so-called « burst release » of drug: Two major drawbacks commonly associated with drug nanoencapsulation. The drug « squalenoylation » approach resulted in a generic nanomedicine platform with broad pharmacological applications.

CellMAPtracer: A User-Friendly Tracking Tool for Long-Term Migratory and Proliferating Cells Associated with FUCCI Systems.

Cell migration is a fundamental biological process of key importance in health and disease. Advances in imaging techniques have paved the way to monitor cell motility. An ever-growing collection of computational tools to track cells has improved our ability to analyze moving cells. One renowned goal in the field is to provide tools that track cell movement as comprehensively and automatically as possible. However, fully automated tracking over long intervals of time is challenged by dividing cells, thus calling for a combination of automated and supervised tracking. Furthermore, after the emergence of various experimental tools to monitor cell-cycle phases, it is of relevance to integrate the monitoring of cell-cycle phases and motility. We developed CellMAPtracer, a multiplatform tracking system that achieves that goal. It can be operated as a conventional, automated tracking tool of single cells in numerous imaging applications. However, CellMAPtracer also allows adjusting tracked cells in a semiautomated supervised fashion, thereby improving the accuracy and facilitating the long-term tracking of migratory and dividing cells. CellMAPtracer is available with a user-friendly graphical interface and does not require any coding or programming skills. CellMAPtracer is compatible with two- and three-color fluorescent ubiquitination-based cell-cycle indicator (FUCCI) systems and allows the user to accurately monitor various migration parameters throughout the cell cycle, thus having great potential to facilitate new discoveries in cell biology.

Organoids to model liver disease.

SummaryThe organoid model represents a major breakthrough in cell biology that has revolutionised biomedical research. Organoids are 3D physiological in vitro structures that recapitulate morphological and functional features of in vivo tissues and offer significant advantages over traditional cell culture methods. Liver organoids are of particular interest because of the pleiotropy of functions exerted by the human liver, their utility to model different liver diseases, and their potential application as cell-based therapies in regenerative medicine. Moreover, because they can be derived from patient tissues, organoid models offer new perspectives in personalised medicine and drug discovery. In this review, we discuss the current liver organoid models for the study of liver disease.

Potential of transposon-mediated cellular reprogramming towards cell-based therapies.

Induced pluripotent stem (iPS) cells present a seminal discovery in cell biology and promise to support innovative treatments of so far incurable diseases. To translate iPS technology into clinical trials, the safety and stability of these reprogrammed cells needs to be shown. In recent years, different non-viral transposon systems have been developed for the induction of cellular pluripotency, and for the directed differentiation into desired cell types. In this review, we summarize the current state of the art of different transposon systems in iPS-based cell therapies.

Budding yeast, a model and a tool… also for biomedical research

Yeast has been used for thousands of years as a leavening agent and for alcoholic fermentation, but it is only in 1857 that Louis Pasteur described the microorganism at the basis of these two tremendously important economic activities. From there, yeast strains could be selected and modified on a rational basis to optimize these uses, thereby also allowing the development of yeast as a popular eukaryotic model system. This model led to a cornucopia of seminal discoveries in cell biology. For about two decades yeast has also been used as a model and a tool for therapeutic research, from the production of therapeutics and the development of diagnostic tools to the identification of new therapeutic targets, drug candidates and chemical probes. These diverse chemobiological applications of yeast are presented and discussed in the present review article.

Shinya Inoué: A Long Career Advancing Microscopy and Cell Biology (1921-2019).

Shinya Inoué: A Long Career Advancing Microscopy and Cell Biology (1921-2019).

VIPERnano: Improved Live Cell Intracellular Protein Tracking.

Tracking intracellular proteins in live cells has many challenges. The most widely used method, fluorescent protein fusions, can track proteins in their native cellular environment and has led to significant discoveries in cell biology. Fusion proteins add steric bulk to the target protein and can negatively affect native protein function. The use of exogenous probes such as antibodies or protein labels is problematic because these cannot cross the plasma membrane on their own and thus cannot label intracellular targets in cells. We developed a labeling platform, VIPERnano, for live cell imaging of intracellular proteins using a peptide fusion tag (CoilE) to the protein of interest and delivery of a fluorescently labeled probe peptide (CoilR). CoilR and CoilE form an α-helical heterodimer with the protein of interest, rendering a labeled protein. Delivery of CoilR into the cell uses hollow gold nanoshells (HGNs) as the primary delivery vehicle. The technology relies on the conjugation and light-activated release of the CoilR peptide on the surface of the HGNs. We demonstrate light-activated VIPERnano delivery and labeling with two intracellular proteins, localized either in the mitochondria or the nucleus. This technology has the ability to study intracellular protein dynamics and spatial tracking while lessening the steric bulk of tags associated with the protein of interest.

Echinoderm eggs as a model for discoveries in cell biology.

I happen to have been trained in cell and developmental biology in the early 1970s, which was near the beginning of the explosive growth of the field of cell biology. The American Society for Cell Biology had been founded in 1960 and so the field was in its early days. Cell biology research was dominated by the use of the electron microscope and by protein biochemistry. Molecular biology and the use of genetics were in their infancy. When we track the path of discoveries in cell biology contributed by research using echinoderm eggs, we follow the development of new technologies in genetics, molecular biology, biochemistry and biophysics, bioengineering, and imaging. The changes in approaches and methods have led to many key discoveries in cell biology through the use of sea urchin, sand dollar and sea star eggs. These include the discovery of cyclin, cytoplasmic dynein, rho activation for cytokinesis, new membrane addition as a late event in cytokinesis, multiple kinesins playing multiple roles, how flagella beat, the dynamics of microtubules in the mitotic apparatus, control over centrosomes and cell cycle checkpoints, the process of nuclear envelope breakdown for cell division, the discovery of 1-methyl adenine (hormones) as the trigger for meiotic maturation, Ca++ transients controlling cell activation and exocytosis among others. What I hope to provide in this perspective is to highlight some of those wonderful discoveries as my own career evolved to contribute to the field.

Amyloid-β and Tau at theCrossroads of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common form of dementia characterized neuropathologically by senile plaques and neurofibrillary tangles (NFTs). Early breakthroughs in AD research led to the discovery of amyloid-β as the major component of senile plaques and tau protein as the major component of NFTs. Shortly following the identification of the amyloid-β (Aβ) peptide was the discovery that a genetic mutation in the amyloid precursor protein (APP), a type1 transmembrane protein, can be a cause of autosomal dominant familial AD (fAD). These discoveries, coupled with other breakthroughs in cell biology and human genetics, have led to a theory known as the "amyloid hypothesis", which postulates that amyloid-β is the predominant driving factor in AD development. Nonetheless, more recent advances in imaging analysis, biomarkers and mouse models are now redefining this original hypothesis, as it is likely amyloid-β, tau and other pathophysiological mechanism such as inflammation, come together at a crossroads that ultimately leads to the development of AD.

Obituary.

Alessandro Moretta 1953–2018 [Color figure can be viewed at wileyonlinelibrary.com] Alessandro Moretta passed away on 17 February 2018 after a long struggle against cancer. Graduated as a medical doctor in 1978, Alessandro worked for several years at the Ludwig Institute for Cancer Research in Lausanne, Switzerland, then as full professor of histology at the University of Genua Medical School. His scientific career was mostly devoted to the identification and functional characterization of lymphocyte receptors. Significant research on human TCR alfa/beta and TCR gamma/delta was made in early years, but his most impressive studies were on Natural Killer (NK) cells, in which Alessandro and his group made fundamental advances on the biology and functions of the complex array of NK receptors. From 1988 to recent years the jigsaw puzzle of activatory and inhibitory NK molecules has been patiently fitted, with an impressive sequence of milestone papers on the newly discovered relationship between NK cells and the HLA system, the NK anti-tumor and anti-leukemia response and the transplant tolerance in haploidentical combinations. The cytometric community must feel indebted to Alessandro for having unveiled the mysterious map of NK world, making it possible to reliably distinguish reactive from clonal NK proliferations. But such discoveries in cell biology have also paved the way for innovative therapeutic approaches in allogeneic transplantation and anti-cancer treatments, with far-reaching impact in medical sciences. Alessandro has published >500 scientific papers in high rank journals, which made him to be included into the ‘ISI highly cited’ researcher group for immunology and rated as the most cited Italian immunologist over a 10-year period, with >55,000 citations. He has also received several prestigious awards like the “Award for Excellence in Biomedical Research” and the “Yvette Mayent-Institut Curie 2000”. Like all the real great minds, Alessandro was always amicable and collaborative, eager to disseminate and discuss his unsurpassable knowledge on NK cells on any occasion. Despite the worsening of his health he kept on accepting invitations to lecture, stubbornly until a few weeks before his death. We will long his lectures we have enjoyed at ESCCA events and at countless scientific meetings around the world, in which a good old friend, more than a tutor, would share his science, dressed up in that unmistakable, wry Genoese wit, full of bittersweetness. Bruno Brando, M.D. Milan, Italy On behalf of ESCCA / ISCCA

Fluorescence nanoscopy in cell biology.

Fluorescence nanoscopy uniquely combines minimally invasive optical access to the internal nanoscale structure and dynamics of cells and tissues with molecular detection specificity. While the basic physical principles of 'super-resolution' imaging were discovered in the 1990s, with initial experimental demonstrations following in 2000, the broad application of super-resolution imaging to address cell-biological questions has only more recently emerged. Nanoscopy approaches have begun to facilitate discoveries in cell biology and to add new knowledge. One current direction for method improvement is the ambition to quantitatively account for each molecule under investigation and assess true molecular colocalization patterns via multi-colour analyses. In pursuing this goal, the labelling of individual molecules to enable their visualization has emerged as a central challenge. Extending nanoscale imaging into (sliced) tissue and whole-animal contexts is a further goal. In this Review we describe the successes to date and discuss current obstacles and possibilities for further development.

Foreword—Microphysiological Systems

It has been increasingly realized that the conventional planar cell cultures do not necessarily reproduce human physiology in vitro due to their limited ability to reproduce the structural and functional complexity of the in vivo counterparts, often resulting in biased outcomes of biological and pharmacological interrogations. On the other hand, the animal models, while competent in reproducing the complex physiology, their discrepancy in anatomy and the genetics against the humans inevitably lead to the mismatch in response towards drugs, chemicals, and toxins, thus resulting in inaccurate predictions. These facts apply to essentially every scenario that we can imagine, ranging from basic science discoveries in cell biology where studies are performed on single-cell levels all the way to systems biology where investigations at the tissue/organ levels are conducted—simply because that the three-dimensional, hierarchical microenvironment intertwined with multi-component biochemical and biophysical cues are so important that they significantly affect every level of biological function—from individual cells to tissue building units and to organs.

Impact of New Camera Technologies on Discoveries in Cell Biology.

New technologies can make previously invisible phenomena visible. Nowhere is this more obvious than in the field of light microscopy. Beginning with the observation of "animalcules" by Antonie van Leeuwenhoek, when he figured out how to achieve high magnification by shaping lenses, microscopy has advanced to this day by a continued march of discoveries driven by technical innovations. Recent advances in single-molecule-based technologies have achieved unprecedented resolution, and were the basis of the Nobel prize in Chemistry in 2014. In this article, we focus on developments in camera technologies and associated image processing that have been a major driver of technical innovations in light microscopy. We describe five types of developments in camera technology: video-based analog contrast enhancement, charge-coupled devices (CCDs), intensified sensors, electron multiplying gain, and scientific complementary metal-oxide-semiconductor cameras, which, together, have had major impacts in light microscopy.

Deep Imaging: the next frontier in microscopy.

The microscope is the quintessential tool for discovery in cell biology. From its earliest incarnation as a tool to make the unseen visible, microscopes have been at the center of most revolutionizing developments in cell biology, histology and pathology. Major quantum leaps in imaging involved the dramatic improvements in resolution to see increasingly smaller structures, methods to visualize specific molecules inside of cells and tissues, and the ability to peer into living cells to study dynamics of molecules and cellular structures. The latest revolution in microscopy is Deep Imaging-the ability to look at very large numbers of samples by high-throughput microscopy at high spatial and temporal resolution. This approach is rooted in the development of fully automated high-resolution microscopes and the application of advanced computational image analysis and mining methods. Deep Imaging is enabling two novel, powerful approaches in cell biology: the ability to image thousands of samples with high optical precision allows every discernible morphological pattern to be used as a read-out in large-scale imaging-based screens, particularly in conjunction with RNAi-based screening technology; in addition, the capacity to capture large numbers of images, combined with advanced computational image analysis methods, has also opened the door to detect and analyze very rare cellular events. These two applications of Deep Imaging are revolutionizing cell biology.