STAR Protocols最新文献

The silk glands (SGs) of silkworms specifically synthesize silk proteins, thus strongly influencing the yield and quality of silk. Here, we present a protocol for isolating SG nuclei from silkworms and obtaining high-quality tissue slices for spatial transcriptomics. We describe steps for rearing, dissecting, and nucleus isolation. We then detail procedures for embedding, frozen section, and RNA capturing and sequencing. This protocol enables the exploration of the spatial distribution of SG cells at single-cell resolution. For complete details on the use and execution of this protocol, please refer to Ma et al.¹.

Liver sinusoidal endothelial cells (LSECs) line the liver sinusoids and play a crucial role in liver function. Isolating LSECs is beneficial for their functional evaluation in vitro. Here, we provide a protocol for obtaining purified LSECs from mice via gradient centrifugation and magnetic cell sorting (MACS), yielding cells suitable for culture and downstream analyses. We describe steps for culturing the purified LSECs and demonstrate their evaluation by flow cytometry. For complete details on the use and execution of this protocol, please refer to Papaioannou et al.¹.

Studies of human induced pluripotent stem cell (iPSC)-derived neurons promise important insights into neurodegenerative diseases. Here, we present a protocol for live imaging of axonal transport in glutamatergic iPSC-derived neurons (iNeurons). We describe steps for the differentiation of iPSCs into iNeurons via PiggyBac-mediated neurogenin 2 (NGN2) delivery, iNeuron culture and transfection, and the acquisition and analysis of time-lapse images. Our protocol is optimized for the widely available catalog of KOLF2.1J iPSCs with mutations relevant to neurodegenerative diseases but is also applicable to other iPSC lines. For complete details on the use and execution of this protocol, please refer to Dou et al.^1,2.

The endothelium is the gatekeeper of vessel health, and its dysfunction is pivotal in driving atherogenesis. Here, we present a protocol to replicate endothelial-macrophage crosstalk during atherogenesis, called the "atherogenesis-on-chip" model, based on the Emulate dual-channel perfusion system. We describe a model for studying endothelial-macrophage interactions during atherogenesis in human aortic endothelial cells and human macrophages using qPCR and secretome analysis, fluorescence microscopy, and flow cytometry. This protocol could be adapted toward more complex plaque microenvironment or other disease settings.

Voltage-dependent anion channel 1 (VDAC1) is a key protein in cellular metabolism and apoptosis. Here, we present a protocol to express and purify milligram amounts of recombinant VDAC1 in Escherichia coli. We detail steps for a fluorescence polarization-based high-throughput screening assay using NADH displacement, along with procedures for thermostability, fluorescence polarization, and X-ray crystallography. In this context, we demonstrate how 2-methyl-2,4-pentanediol (MPD), a crystallization reagent, interferes with VDAC1 small-molecule binding, hindering the detection of these ligands in the crystal. For complete details on the use and execution of this protocol, please refer to Conti Nibali et al.¹.

Human pluripotent stem cells (hPSCs) provide a powerful platform for generating hematopoietic progenitor cells (HPCs) and investigating hematopoietic development. Here, we present a protocol for maintaining hPSCs and inducing their differentiation into HPCs through the endothelial-to-hematopoietic transition (EHT) on vitronectin-coated plates. We outline steps for evaluating the efficiency of HPC generation and assessing their potential to differentiate into various hematopoietic lineages. This protocol serves as a framework for exploring human hematopoiesis and generating various functional blood cells. For complete details on the use and execution of this protocol, please refer to Shen et al.¹ and Qu et al.².

Mechanistic target of rapamycin complex 1 (mTorC1) activity plays a crucial role in brain development. Here, we present an approach for rapamycin microinjection into the habenula of larval zebrafish to achieve localized inhibition of the mTorC1 pathway and explore the role of mTorC1 in habenula function. We describe steps for performing microinjections and maintaining zebrafish larvae before and after the procedure. For complete details on the use and execution of this protocol, please refer to Doszyn et al.¹.

Angiogenesis begins as endothelial cells migrate, forming a sprouting tip and subsequent growth-rich stalk cells. Here, we present a protocol for transcriptomic and epigenomic analyses of tip-like cells in cultured endothelial cells. We describe steps for stimulating human umbilical vein endothelial cells (HUVECs) with vascular endothelial cell growth factor (VEGF) to generate tip-like cells. We then detail procedures for library preparation for single-cell RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq), and data analysis. This scalable protocol is also applicable to diverse omics studies, including proteomics and metabolomics. For complete details on the use and execution of this protocol, please refer to Miyamura et al.¹.

The recombinase polymerase amplification (RPA)-CRISPR-Cas12a-FQ system enables sensitive detection of environmental DNA (eDNA) in rare fish species. Here, we present a protocol for eDNA amplification and Cas12a for target recognition using RPA. We describe steps for identifying a target site, synthesis and purification of CRISPR RNA (crRNA), and RPA isothermal amplification. We then detail procedures for constructing the eDNA CRISPR-Cas12a detection system and verifying its sensitivity. This protocol offers a high-sensitivity approach for monitoring aquatic biodiversity and conservation efforts, even in low eDNA concentrations. For complete details on the use and execution of this protocol, please refer to Wei et al.¹.

Biotinylation by antibody recognition (BAR) is an antibody-based approach for mapping proximal protein interactions in cells. Here, we present a protocol to biotinylate and identify proximal proteins using BAR. We describe steps for defining proximity labeling reaction conditions, assessing enrichment using western blot, and sample preparation for mass spectroscopy analysis. We then detail procedures for data analysis and identifying proximal proteins. This approach differs from standard proximity labeling techniques, which rely on genetically engineered enzymes fused to the target protein. For complete details on the use and execution of this protocol, please refer to Rega et al.¹.