Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2020.02.22.960559

Visualizing ultrastructural details of placental tissue with super-resolution structured illumination microscopy

Villedgas-Hernandez, L. E.·Nystad, M.·Strohl, F.·Basnet, P.·Acharya, G.·Ahluwalia, B. S.
View original source ↗Export metadata ↓

Abstract

Super-resolution fluorescence microscopy is a widely employed technique in cell biology research, yet remains relatively unexplored in the field of histo-pathology. Here, we describe the sample preparation steps and acquisition parameters necessary to obtain fluorescent multicolor super-resolution structured illumination microscopy (SIM) images of both formalin-fixed paraffin-embedded and cryo-preserved placental tissue sections. We compare super-resolved images of chorionic villi against diffraction-limited deconvolution microscopy and demonstrate the significant contrast and resolution enhancement attainable with SIM. We show that SIM resolves ultrastructural details such as the syncytiotrophoblasts microvilli brush border, which up until now has been only resolvable by electron microscopy.

Source connections

Explore related subjects

pathologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Villedgas-Hernandez, L. E., Nystad, M., Strohl, F., Basnet, P., Acharya, G., Ahluwalia, B. S.. 2020-02-25. Visualizing ultrastructural details of placental tissue with super-resolution structured illumination microscopy. https://doi.org/10.1101/2020.02.22.960559

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

NAE1-Dependent Protein Neddylation Preserves Endothelial Identity and Vascular Integrity

Background: Endothelial dysfunction is a central driver of cardiovascular and inflammatory diseases, yet the post-translational mechanisms that preserve endothelial homeostasis remain incompletely understood. Protein neddylation, the covalent conjugation of a ubiquitin-like modifier, regulates diverse cellular processes, yet its physiological role in the vascular endothelium remains unknown. This study investigated whether protein neddylation is required to preserve endothelial identity and vascular homeostasis. Methods: We generated tamoxifen-inducible endothelial-specific Nae1 knockout mice to inhibit neddylation and combined bulk RNA sequencing, single-cell and single-nucleus transcriptomics, quantitative proteomics, biochemical analyses, and gain- and loss-of-function approaches to define the role of endothelial neddylation in vascular homeostasis and inflammatory injury. Results: Endothelial-specific Nae1 deletion caused rapid mortality associated with vascular leakage, platelet accumulation, inflammation, and multi-organ injury. Multi-omics analyses demonstrated profound loss of endothelial identity, characterized by suppression of core endothelial programs and activation of inflammatory, procoagulant, and pyroptotic pathways. Single-cell analyses revealed progressive endothelial dysfunction culminating in depletion of the endothelial population and remodeling of the vascular niche. Mechanistically, endothelial neddylation deficiency activated gasdermin D (GSDMD)- and gasdermin E (GSDME)-dependent pyroptosis, whereas dual inhibition of GSDMD and GSDME markedly attenuated inflammatory transcriptomic remodeling, vascular injury, hepatocyte death, immune cell infiltration, and platelet accumulation. Translational analyses demonstrated reduced endothelial neddylation in experimental endotoxemia and decreased expression of neddylation pathway components in human atherosclerosis and COVID-19 datasets. Conversely, restoration of endothelial neddylation partially reversed inflammatory endothelial transcriptomic reprogramming in vivo. Conclusions: NAE1-dependent protein neddylation is an essential regulator of endothelial identity and vascular integrity. Loss of endothelial neddylation promotes gasdermin-dependent pyroptosis and thrombo-inflammatory vascular injury, whereas restoration of the neddylation pathway mitigates inflammatory endothelial dysfunction. These findings identify endothelial neddylation as a fundamental mechanism maintaining vascular homeostasis and a potential therapeutic target for cardiovascular and inflammatory diseases.

pathology↗
bioRxiv2020

Accurate Diagnosis of Colorectal Cancer Based on Histopathology Images Using Artificial Intelligence

BackgroundAccurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on their daily image analyses. MethodsBased on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC prediction/diagnosis using weakly labeled pathological whole slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, >14,680 WSIs, from >9,631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, U.S., and Germany. ResultsOur innovative AI tool was consistently nearly perfectly agreed with (average Kappa-statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multi-centers. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.981 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells. ConclusionsThis first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. Hence, it will drastically alleviate the heavy clinical burden of daily pathology diagnosis, and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

pathology↗
bioRxiv2020

Angioplasty-induced epigenomic remodeling entails BRD4 and EZH2 hierarchical regulations

Atherosclerosis is commonly treated with angioplasty which, however, evokes neointimal hyperplasia (IH) and recurrent stenotic diseases. Epigenomic investigation was lacking on post-angioplasty IH. The histone acetylation reader BRD4 and H3K27me3 writer EZH2 are potent epigenetic factors; their relationship is little understood. Through genome-wide survey in the rat angioplasty model, we studied BRD4 and EZH2 functional regulations involved in IH. We performed chromatin immunoprecipitation sequencing (ChIPseq) using rat carotid arteries. While H3K27me3 ChIPseq signal prevalently intensified in balloon-injured (vs uninjured) arteries, BRD4 and H3K27ac became more enriched at Ezh2. Indeed, BRD4-siRNA or CRISPR-deletion of BRD4-associated enhancer abated the smooth muscle cell (SMC) expression of EZH2, and SMC-specific BRD4 knockout in BRD4fl/fl; Myh11CreERT2 mice reduced both H3K27me3 and IH in wire-injured femoral arteries. In accordance, post-angioplasty IH was exacerbated and mitigated, respectively, by lentiviral expression and pharmacological inhibition of EZH2/1; EZH2 (or EZH1) loss- and gain-of-function respectively attenuated and aggravated pro-IH SMC proliferative behaviors. Furthermore, while H3K27me3 ChIPseq signal magnified at P57 and ebbed at Ccnd1 and Uhrf1 after injury, silencing either EZH2 or EZH1 in SMCs up-regulated P57 and down-regulated Ccnd1 and Uhrf1. In summary, our results reveal an upsurge of EZH2/H3K27me3 after angioplasty, BRD4s control over EZH2 expression, and non-redundant EZH2/1 functions. As such, this study unravels angioplasty-induced loci-specific H3K27me3/ac redistribution in the epigenomic landscape rationalizing BRD4/EZH2-governed pro-IH regulations.

pathology↗