This protocol allows one to identify factors that modulate functional beta cell mass to find potential therapeutic targets for the treatment of diabetes. The protocol consists of a streamlined method to assess islet replication and beta cell function in isolated rat islets following manipulation of gene expression with adenoviruses.
1Department of Biotechnology & Bioinformatics, California State University Channel Islands, 2Department of Diabetes, Endocrinology and Metabolism, Beckman Research Institute of City of Hope, 3The Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope
A three-dimensional clonogenic assay that allows pancreatic-like progenitors to differentiate into insulin-expressing colonies is described. This method takes advantage of semi-solid media containing methylcellulose, Matrigel and growth factors, in which single progenitors proliferate and differentiate in vitro, permitting quantification of the number of functional progenitors in a population.
A novel impulsive cell pressurization experiment has been developed using a Kolsky bar device to investigate the molecular/cellular mechanisms of blast-induced traumatic brain injury.
Generation of T lymphocytes from induced pluripotent stem (iPS) cells gives an alternative approach of using embryonic stem cells for T cell-based immunotherapy. The method shows that by utilizing either in vitro or in vivo induction system, iPS cells are able to differentiate into both conventional and antigen-specific T lymphocytes.
The following protocol provides techniques for encapsulating pancreatic β-cells in step-growth PEG-peptide hydrogels formed by thiol-ene photo-click reactions. This material platform not only offers a cytocompatible microenvironment for cell encapsulation, but also permits user-controlled rapid recovery of cell structures formed within the hydrogels.
Computer-assisted Large-scale Visualization and Quantification of Pancreatic Islet Mass, Size Distribution and Architecture
1Department of Medicine, University of Chicago, 2Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 3Department of Surgery, University of Chicago, 4Diabetes Division, University of Massachusetts
Novel computer-assisted methods of large-scale procurement and analysis of immunohistochemically stained pancreatic specimens are described: (1) Virtual Slice capture of the entire section; (2) Mass analysis of large-scale data; (3) Reconstruction of 2D Virtual Slices; (4) 3D islet mapping; and (5) Mathematical analysis.
In this report we describe a method for the isolation and culture of the progenitor cell niche from the embryonic mouse kidney that can be used to study signaling pathways regulating stem/progenitor cells of the developing kidney. These cultured cells are highly accessible to small molecule and recombinant protein treatment, and importantly also to viral transduction, which allows efficient manipulation of candidate pathways.
The following protocol outlines the process of pancreatic dissection for virtual slice imaging, and the subsequent quantification of all GFP-tagged beta-cells in the entire pancreas.
1Department of Cell and Developmental Biology, Center for Stem Cell Biology, Vanderbilt University Medical Center, 2Department of Pharmacology, Center for Stem Cell Biology, Vanderbilt University Medical Center, 3Vanderbilt University Medical Center
Isolation of embryonic neural crest from the neural tube facilitates the use of in vitro methods for studying migration, self-renewal, and multipotency of neural crest.
1Department of Biochemistry & Molecular Biology, Wayne State University School of Medicine, 2Cardiovascular Research Institute, Wayne State University School of Medicine, 3Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine
Cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial chloride channel, has been reported to interact with various proteins and regulate important cellular processes; among them the CFTR PDZ motif-mediated interactions have been well documented. This protocol describes methods we developed to assemble a PDZ-dependent CFTR macromolecular signaling complex in vitro.
A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation
We present a variation of the QUICK (QUantitative Immunoprecipitation Combined with Knockdown) approach that was introduced previously to distinguish between true and false protein-protein interactions. Our approach is based on 15N metabolic labeling, the modulation of affinities of protein-protein interactions by the presence/absence of ATP, immunoprecipitation, and quantitative mass spectrometry.
Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia, Institute of Diabetes Obesity and Metabolism, Institute for Regenerative Medicine, Department of Pediatrics, University of Pennsylvania-School of Medicine
We have derived a strategy to detect sequential incorporation of thymidine analogues (CldU and IdU) into tissues of adult mice to quantify two successive rounds of cell division. This strategy is useful to detect cell turnover of long-lived tissues, oncogenic transformation, or transit-amplifying cells.
Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry
1Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 2Deparment of Biochemistry, Research and Innovation Centre, University of Regina, 3Department of Medical Genetics and Microbiology, University of Toronto
Affinity purification of tagged proteins in combination with mass spectrometry (APMS) is a powerful method for the systematic mapping of protein interaction networks and for investigating the mechanistic basis of biological processes. Here, we describe an optimized sequential peptide affinity (SPA) APMS procedure developed for the bacterium Escherichia coli that can be used to isolate and characterize stable multi-protein complexes to near homogeneity even starting from low copy numbers per cell.
Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography
The cell permeable crosslinker DSP [dithiobis-(succinimidyl propionate)] stabilizes transient and labile interactions in vivo, which allows their isolation using stringent protein complex purification techniques. Here we present a technique for crosslinking cells grown in culture followed by isolation of protein complexes by immunoprecipitation.
This video demonstrates procedures for characterization of human pancreatic islets using hematoxylin and eosin (H&E) and immunohistochemistry (IHC). Pancreatic sections from head, body, and tail regions are stained by both H&E and IHC to determine islet endocrine composition (insulin, glucagon, and pancreatic polypeptide), cell replication (Ki67), and inflammatory infiltrates (H&E, CD3). The uncinate region is localized using IHC for pancreatic polypeptide.
Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization
1Department of Pathology, New York University School of Medicine, 2New York University Center for Health Informatics and Bioinformatics, 3NYU Cancer Institute, 4Department of Pathology and Yale Cancer Center, Yale University School of Medicine
Here we describe a protocol for simultaneous detection of histone modifications by immunofluorescence and DNA sequences by DNA FISH followed by 3D microscopy and analyses (3D immuno-DNA FISH).
1UCSF Diabetes Center and Department of Cell and Tissue Biology, University of California, San Francisco, 2Department of Biology, University of Copenhagen, Denmark, 3National Institute of Nutrition and Seafood Research, Bergen, Norway
Primary white preadipocytes isolated from white adipose tissues in mice can be differentiated into beige/brite cells. Presented here is a reliable cellular model system to study the molecular regulation of "browning" of white fat.
1Department of Neurology, Emory University School of Medicine, 2Coulter Department of Biomedical Engineering, Laboratory for Neuroengineering, Georgia Institute of Technology and Emory, University School of Medicine, 3Emory University School of Medicine
This protocol provides the necessary information for setting up, caring for, recording from and electrically stimulating cultures on MEAs. In vitro networks provide a means for asking physiologically relevant questions at the network and cellular levels leading to a better understanding of brain function and dysfunction.
Described is a two-step labeling process using β-glucosyltransferase (β-GT) to transfer an azide-glucose to 5-hmC, followed by click chemistry to transfer a biotin linker for easy and density-independent enrichment. This efficient and specific labeling method enables enrichment of 5-hmC with extremely low background and high-throughput epigenomic mapping via next-generation sequencing.
1Department of Energy, Environmental and Chemical Engineering, Washington University, 2Department of Biology, Washington University, 3Department of Energy, Environmental and Chemical Engineering and Department of Biology, Washington University
13C-isotope labeling is a useful technique for determining the cell central metabolism for various types of microorganisms. After cells have been cultured with a specific labeled substrate, GC-MS measurement can reveal functional metabolic pathways based on unique labeling patterns in proteinogenic amino acids.
Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding
1College of Nursing, Interdisciplinary Life Sciences Research Laboratory, Seattle University, 2College of Science and Engineering, Interdisciplinary Life Sciences Research Laboratory, Seattle University, 3School of Medicine, University of Washington
An in vitro method for preparing functional glucocorticoid receptor (GR)•hsp90 protein complexes from purified proteins and cellular lysates is described. The method utilizes immunoadsorption of recombinant GR followed by salt-stripping and protein complex reconstitution. The importance of cofactors and buffer conditions are discussed, as are potential method applications.
We describe a set of assays to analyze expression levels of H1 linker histones. mRNA of individual H1 genes are quantitatively measured by random primer based reverse transcription followed by real-time PCR, whereas protein quantification of H1 histones is achieved by HPLC analysis.
MamA is a unique Magnetosome associated protein which was shown to be involved in magnetosome activation. Here we present the purification protocol of MamA deletion mutant (MamAΔ41) from M. magneticum AMB-1.
A lensless on-chip fluorescent microscopy platform is demonstrated that can image fluorescent objects over an ultra-wide field-of-view of e.g., >0.6-8 cm2 with <4μm resolution using a compressive sampling based decoding algorithm. Such a compact and wide-field fluorescent on-chip imaging modality could be valuable for high-throughput cytometry, rare-cell research and microarray-analysis.
Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis
This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS).
Plant viral nanoparticles (VNPs) are promising platforms for applications in biomedicine. Here, we describe the procedures for plant VNP propagation, purification, characterization, and bioconjugation. Finally, we show the application of VNPs for tumor homing and imaging using a mouse xenograft model and fluorescence imaging.
1Molecular and Cellular Biochemistry, Center for Molecular Neurobiology, The Ohio State University, 2Integrated Biomedical Science Graduate Program, The Ohio State University, 3Comprehensive Cancer Center, The Ohio State University
Transplantation of isolated islets has been proposed to be a potential treatment for type 1 diabetes. Here we describe a method to isolate islets from mouse pancreata and transplant them to the subcapsular space of the kidney.
1Undergraduate Program, Rice University, 2Proteomics Facility, Department of Pathology, University of Texas MD Anderson Cancer Center, 3Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, 4University of Texas Graduate School of Biological Sciences at Houston
A specific and sensitive method to gain insight into the expression profile of glycosphingolipid antigens in immune organs and cells is described. The method takes advantage of the ion trap mass spectrometry allowing step-wise fragmentation of glycosphingolipid molecules for structural analysis in comparison to chemically synthesized standards.
Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry (CCMS)
Capture Compounds are trifunctional small molecules to reduce the complexity of the proteome by functional reversible small molecule-protein interaction followed by photo-crosslinking and purification. Here we use a Capture Compound with S-adenosyl-L-homocysteine-binding as selectivity function to isolate methyltransferases from an Escherichia coli whole cell lysate and identify them by MS.
Biophysical and biochemical studies of interactions among membrane-embedded protein domains face many technical challenges, the first of which is obtaining appropriate study material. This article describes a protocol for producing and purifying disulfide-stabilized transmembrane peptide complexes that are suitable for structural analysis by solution nuclear magnetic resonance (NMR) and other analytical applications.
A rapid way is described to gain insights into the structure of polysaccharides in an extracellular matrix. The method takes advantage of the specificity of glycosylhydrolases and the sensitivity of mass spectrometry allowing minute amounts of materials to be analyzed. This technique is adaptable to be used directly on tissue itself.
The Logic, Experimental Steps, and Potential of Heterologous Natural Product Biosynthesis Featuring the Complex Antibiotic Erythromycin A Produced Through E. coli
The heterologous biosynthesis of erythromycin A through E. coli includes the following experimental steps: 1) genetic transfer; 2) heterologous reconstitution; and 3) product analysis. Each step will be explained in the context of the motivation, potential, and challenges in producing therapeutic natural products using E. coli as a surrogate host.
Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises
The experiments demonstrate an easy approach for students to gain experience in examining muscle structure, synaptic responses, the effects of ion gradients and permeability on membrane potentials. Also, a sensory-CNS-motor-muscle circuit is presented to show a means to test effects of compounds on a neuronal circuit.
Near Infrared Optical Projection Tomography for Assessments of β-cell Mass Distribution in Diabetes Research
1Umeå Centre for Molecular Medicine, Umeå University, 2Cell Transplant Center, Diabetes Research Institute, University of Miami,, 3EMBL-CRG Systems Biology Program, Centre for Genomic Regulation, Catalan Institute of Research and Advanced Studies, 4Dept. of Computing Science, Umeå University
We describe the adaptation of optical projection tomography (OPT)1 to imaging in the near infrared spectrum, and the implementation of a number of computational tools. These protocols enable assessments of pancreatic β-cell mass (BCM) in larger specimens, increase the multichannel capacity of the technique and increase the quality of OPT data.
Basic Surgical Techniques in the Göttingen Minipig: Intubation, Bladder Catheterization, Femoral Vessel Catheterization, and Transcardial Perfusion
1Department of Neurosurgery, Aarhus University Hospital, 2Department of Neurobiology, Institute of Anatomy, Faculty of Health Sciences, Aarhus University, 3Positron Emission Tomography (PET) Centre, Aarhus University Hospital
The use of domestic and miniature pigs in science has increased significantly in recent years. By demonstrating how to perform intubation, transurethral bladder catheterization, femoral artery and vein catheterization, as well as transcardial perfusion, we aim to further increase the value of Göttingen minipigs in biomedical research.
Synthesis of Nine-atom Deltahedral Zintl Ions of Germanium and their Functionalization with Organic Groups
We present the high-temperature synthesis of intermetallic precursors K4Ge9, their dissolution in ethylenediamine to form Ge94- deltahedral Zintl ions, and the reaction of the clusters with alkynes to form organo-Zintl ions. The latter are characterized by electrospray mass spectrometry in solutions and by single-crystal X-ray diffraction in the solid state.
Preparation of Synaptoneurosomes from Mouse Cortex using a Discontinuous Percoll-Sucrose Density Gradient
1Department of Pathology and Laboratory Medicine, Waisman Center for Developmental Disabilities, University of Wisconsin, 2Department of Biochemistry, Waisman Center for Developmental Disabilities, University of Wisconsin
A method to prepare translationally active, intact synaptoneurosomes (SNs) from mouse brain cortex is described. The method uses a discontinuous Percoll-sucrose density gradient allowing for the quick preparation of active SNs.
Ion mobility-mass spectrometry is an emerging gas-phase technology that separates ions, based on their collision cross-section and mass. The method provides three-dimensional information on the overall topology and shape of protein complexes. Here, we outline a basic procedure for instrument setting and optimization, calibration of drift times, and data interpretation.
Mass spectrometry has proven to be a valuable tool for analyzing large protein complexes. This method enables insights into the composition, stoichiometry and overall architecture of multi-subunit assemblies. Here, we describe, step-by-step, how to perform a structural mass spectrometry analysis, and characterize macromolecular structures.
We seek to define the neural immune signaling responsible for cold-preconditioning as means to identify novel targets for therapeutics development to protect brain before injury onset. We present strategies for such work that require biological systems, experimental manipulations plus technical capacities that are highly reproducible and sensitive.
Identification and Characterization of Protein Glycosylation using Specific Endo- and Exoglycosidases
Using specific glycosidases to remove sugars from glycoproteins followed by SDS-PAGE is a valuable method to detect glycan modifications on protein samples and is a good choice for initial glycobiology studies. Changes following deglycosylation can be detected as shifts in gel mobility or by staining with glycan sensitive reagents.
A method of functional imaging of mouse brown adipose tissue (BAT) is described in which cold-stimulated uptake of 18F-Fluorodeoxyglucose (FDG) in BAT is non-invasively assessed with a standardized micro-PET/CT protocol. This method is robust and sensitive to detect differences in BAT activities in mouse models.
Here we describe a growth assay for Staphylococcus aureus using hemoglobin as the sole source of available nutrient iron. This assay establishes the role of bacterial factors involved in hemoglobin-derived iron acquisition.
1Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 2Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, 3Department of Neurology, University of California, Los Angeles
Photo-induced cross-linking of unmodified proteins (PICUP) allows characterization of oligomer size distribution in metastable protein mixtures. We demonstrate application of PICUP to three representative amyloidogenic peptides the 40- and 42-residue forms of amyloid β-protein, and calcitonin, and a control peptide growth-hormone releasing factor.
Stable isotope labeling workflows employing 18O-enriched water (LeO-workflows) are versatile tools for quantitative and qualitative proteomics studies. In protease-assisted (PALeO) workflows, 18O-atoms are introduced by proteolytic cleavage and carboxyl oxygen exchange reactions mediated by proteases. In the acid-catalyzed (ALeO) workflow, 18O-atoms are introduced by carboxyl oxygen exchange at low pH.
This report provides a visual depiction of parallel-plate flow chamber analysis for studying leukocyte endothelial interactions under physiologic shear stress. This method is particularly useful for investigating the role of endothelial (E)-selectin and leukocyte E-selectin ligands that trigger leukocyte rolling on endothelial cell surfaces.
1Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, 2London Regional Cancer Program, Children's Health Research Institute, and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario
Determining the cell cycle position of a population of cells, or understanding how signals affect proliferation, can be readily measured by flow cytometry using this protocol. We report a simple experimental approach to staining cells and quantifying their position in the cell cycle.
In this video, we demonstrate the procedure of CD40-activation and expansion of murine B cells from splenocytes of C57BL/6 mice, which can be used as a model antigen-presenting cell (APC) to study induction of immunity.
We aimed to develop a reproducible protocol for isolating and maintaining long-term cultures of human fungiform taste papillae cells. Cells from human fungiform papillae obtained by biopsy were successfully maintained in culture for more than eight passages (12 months) without loss of viability.
We present a protocol to produce antigen-specific mouse T-cells using retroviral transduction