1. Preparing and counting the Namalwa cells
<ol>
	<li>Remove cells from culture flask and centrifuge the cells to pellet. Remove supernatant and resuspend cells in a known volume of PBS. The cells used in this protocol are suspension cells. If you are using adherent cells you will need to trypsinize before collecting.</li>
	<li>To determine the number of live cells, stain an aliquot of the cell suspension by mixing it 1:1 with a 0.4% trypan blue solution and pipet 10 &#956;l of the mixture onto a counting slide, and then insert the slide into the TC10 automated cell counter (Bio-Rad Laboratories, Inc).</li>
	<li>The TC10 cell counter will autofocus to assure the most accurate count, and then proceed with counting. It automatically determines the density of live cells and total cells in the sample.</li>
	<li>Select view image to display the cells on the viewscreen. Then select the dilution calculator to have the TC10 cell counter automatically calculate the amount of cell mixture that will be needed.</li>
	<li>This experiment is using a total of three siRNAs: one control siRNA and two different siRNAs targeting the STAT6 gene, plus untransfected controls. This requires 3.6 ml at a final concentration of 5 X 106 cells per ml.</li>
	<li>Enter the desired concentration and final volume values into the dilution calculator, and it calculates the volume of cell suspension needed based on the live cell count for that sample. Alternatively, perform the calculation manually. Then transfer the required volume of cell mixture for these experiments into a new tube.</li>
	<li>Spin the cell mixtures to pellet the cells and remove all the PBS. Resuspend in 3.6 ml of Gene Pulser electroporation buffer (Bio-Rad Laboratories). Transfer 800 &#956;l aliquots into tubes containing the appropriate siRNAs and mix gently. The cells are now ready for electroporation.</li>
</ol>
2. Electroporating the cells in 96-well Plates
<ol>
	<li>The 96-well electroporation plate allows the replicates for all four treatments to be electroporated together.</li>
	<li>Transfer 150 &#956;l of the cell suspension into the appropriate wells of a 96-well electroporation plate.</li>
	<li>Insert the plate in the MXcell electroporation plate chamber and close the lid.</li>
	<li>Electroporate using settings optimized for the cell line and buffer being used. These cells are electroporated using an exponential decay wave with instrument settings of 250 V, 350 &#956;F, and 1000 &#937; resistance.</li>
	<li>After electroporation is complete, pipette up and down gently in each well to mix and then transfer cells to a tissue culture plate containing pre-warmed media. Namalwa cells are grown in RPMI (Life Technologies) supplemented with 7.5% FCS and 1% pyruvate.</li>
	<li>Control samples that have not been electroporated are taken from the remaining cell suspension and added to culture dishes of pre-warmed culture medium identically to the electroporated cells.</li>
	<li>Incubate cells overnight at 37&#176;C with 5% CO2.</li>
	<li>After 24 hr, one set of cells was induced with 10 ng/ml final concentration recombinant IL-4 (R&#38;D Systems). The second set of control cells only receive additional media. All cells are incubated an additional 24 hr at 37&#176;C and 5% CO2.</li>
</ol>
3. Extract and check RNA
<ol>
	<li>After a total of 48 hr of growth, count the cells in each well, and transfer one aliquot from each well to a microfuge tube for RNA extraction, and freeze a second aliquot for western blotting or other protein analysis.</li>
	<li>Centrifuge samples to pellet the cells, and then remove and discard the supernatant from each tube.</li>
	<li>Proceed with the RNA extraction. We typically use the Aurum total RNA kit (Bio-Rad) according to the included protocol.</li>
	<li>When monitoring siRNA mediated gene knockdown it is particularly important to verify RNA quality because degraded RNA will give misleading results. The 260/280 ratio does not indicate RNA integrity therefore it is important to run the samples on a gel or microfluidic device to confirm RNA are not degraded.</li>
	<li>To assess both quality and quantity in one step, these samples will be analyzed using the Experion automated electrophoresis system (Bio-Rad).</li>
	<li>First, heat samples. Then, prime, load, and vortex the Experion RNA chip. Insert the chip into the Experion electrophoresis station and start run.</li>
	<li>After the run is complete, the Experion software will display results automatically in the form of an electropherogram, results table (that displays RNA concentration, ribosomal ratio, and the RNA quality indicator number), and virtual gel (which looks similar to a traditional RNA gel). High quality total RNA samples will typically have an RQI of 8-10.</li>
</ol>
4. Real-time PCR
<ol>
	<li>After verifying the RNA quality, proceed with the cDNA reactions. This experiment used the iScript one-step RT-PCR mix (Bio-Rad) to combine cDNA synthesis and real-time PCR in one reaction.</li>
	<li>Make a master mix containing all the reaction components other than the RNA templates for each primer set, and distribute those into the PCR plate.</li>
	<li>After diluting the RNA to a uniform concentration, add the RNA samples to the appropriate wells. Each reaction is set up in triplicate.</li>
	<li>Seal the plate, and place it into the CFX384 real-time PCR system (Bio-Rad). Select the appropriate protocol and begin the run.</li>
	<li>Once the run is complete, gene expression is determined by comparing gene expression of the gene of interest normalized to a reference gene in cells electroporated with experimental siRNA to the same normalization of cells electroporated with a control siRNA.</li>
</ol>
5. Analysis of siRNA knockdown
<ol>
	<li>The expression of CCL17 was monitored using quantitative real-time PCR to investigate the role of the transcriptional activator STAT6 in IL-4 dependent induction of CCL17. For this experiment, GAPDH was used as a reference gene. Alternate reference genes or multiple reference genes can be used in the same manner.</li>
	<li>The CFX Manager software automatically normalized CCL17 expression to expression of the reference gene from the same sample and automatically compared the resulting normalized values to control treatments by simply selecting GAPDH as &#34;reference&#34; and the control treatment (control siRNA without IL-4 induction) as &#34;control&#34; in the experiment settings window of the CFX manager software.</li>
	<li>Without IL-4 induction, transcription of CCL17 remained at low, constitutive levels comparable to the control treatment.</li>
	<li>Cells induced with IL-4 and retaining a normal STAT6 pathway (i.e., control siRNA or untransfected control treatments) showed 8-10 fold induction of CCL17 expression.</li>
	<li>Cells induced with IL-4 but with STAT6 expression inhibited by introduction of either STAT6 siRNA showed only about 2 fold higher CCL17 expression than the uninduced cells confirming the role of STAT6 in the IL-4 induced expression of CCL17.</li>
</ol>
6. Representative Results
<img alt="Figure 1" src="/files/ftp_upload/1904/1904fig1.jpg" /> 
Figure 1. Overview of the IL-4 signaling pathway. 
A) Binding of IL-4 to its receptor leads to dimerization and activation of STAT6. Activated STAT6 translocates to the nucleus and activates transcription of its target genes, such as CC17. 
B) Without IL-4 induction, transcription of CCL17 will remain at low, constitutive levels. 
C) After siRNA-mediated silencing of the STAT6 gene, treatment with IL4 should lead to little or no increase in CCL17 expression.
<img alt="Figure 2" src="/files/ftp_upload/1904/1904fig2.jpg" /> 
Figure 2. Induction of CCL17 by IL4 measured by different conditions by quantitative real time PCR. 
A) Samples grown without IL-4 had a low constitutive level of expression regardless of gene expression. 
B) As shown in green and blue, control samples responded normally to treatment with IL-4; with an 8-10 fold induction of CCL17. However, cells transfected with siRNAs targeting STAT6, shown in red and pink, had diminished CCL17 expression in response to IL-4, supporting the idea that STAT6 plays a role in the IL-4 induced expression of CCL17.

The author is employed by Bio-Rad Laboratories that produces reagents and instruments used in this article.

This article has demonstrated how to electroporate siRNAs into a difficult to transfect suspension cell line and how to follow gene expression in these cells. When doing this procedure it s important to remember to keep things as consistent as possible across all the samples.

using an automated cell counter to simplify gene expression studies: sirna knockdown of il-4 dependent gene expression in namalwa cells

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only to study the effects of downregulating single genes, but also to interrogate signaling pathways and other complex interaction networks.  These pathway analyses require both the use of relevant cellular models and methods that cause less perturbation to the cellular physiology.  Electroporation is increasingly being used as an effective way to introduce siRNA and other nucleic acids into difficult to transfect cell lines and primary cells without altering the signaling pathway under investigation. There are multiple critical steps to a successful siRNA experiment, and there are ways to simplify the work while improving the data quality at several experimental stages.  To help you get started with your siRNA mediated gene knockdown project, we will demonstrate how to perform a pathway study complete from collecting and counting the cells prior to electroporation through post transfection real-time PCR gene expression analysis.  The following study investigates the role of the transcriptional activator STAT6 in IL-4 dependent gene expression of CCL17 in a Burkitt lymphoma cell line (Namalwa).  The techniques demonstrated are useful for a wide range of siRNA-based experiments on both adherent and suspension cells.  We will also show how to streamline cell counting with the TC10 automated cell counter, how to electroporate multiple samples simultaneously using the MXcell electroporation system, and how to simultaneously assess RNA quality and quantity with the Experion automated electrophoresis system.

Watch this Scientific Journal Video about Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells at JoVE.com

Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells

This procedure describes a quick and easy workflow to introduce siRNA into difficult to transfect cell lines and follow gene expression by real-time PCR. Use of an automated cell counter, multi-well electroporation plate, and automated electrophoresis station provide quick and reliable results without the need for expensive robotic handling.

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only ...

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Video: Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells

Using RNA-interference to Investigate the Innate Immune Response in Mouse Macrophages

Macrophages are key phagocytic innate immune cells. When macrophages encounter a pathogen, they produce antimicrobial proteins and compounds to kill the pathogen, produce various cytokines and chemokines to recruit and stimulate other immune cells, and present antigens to stimulate the adaptive immune response. Thus, being able to efficiently manipulate macrophages with techniques such as RNA-interference (RNAi) is critical to our ability to investigate this important innate immune cell. However, macrophages can be technically challenging to transfect and can exhibit inefficient RNAi-induced gene knockdown. In this protocol, we describe methods to efficiently transfect two mouse macrophage cell lines (RAW264.7 and J774A.1) with siRNA using the Amaxa Nucleofector 96-well Shuttle System and describe procedures to maximize the effect of siRNA on gene knockdown. Moreover, the described methods are adapted to work in 96-well format, allowing for medium and high-throughput studies. To demonstrate the utility of this approach, we describe experiments that utilize RNAi to inhibit genes that regulate lipopolysaccharide (LPS)-induced cytokine production.

In this protocol, we describe methods to efficiently transfect murine macrophage cell lines with siRNAs using the Amaxa Nucleofector 96-well Shuttle System, stimulate the macrophages with lipopolysaccharide, and monitor the effects on inflammatory cytokine production.

Macrophages are key phagocytic innate immune cells.  When macrophages encounter a pathogen, they produce antimicrobial proteins and compounds to kill the ...

Immunology and Infection

Highly Efficient Transfection of Human THP-1 Macrophages by Nucleofection

Macrophages, as key players of the innate immune response, are at the focus of research dealing with tissue homeostasis or various pathologies. Transfection with siRNA and plasmid DNA is an efficient tool for studying their function, but transfection of macrophages is not a trivial matter. Although many different approaches for transfection of eukaryotic cells are available, only few allow reliable and efficient transfection of macrophages, but reduced cell vitality and severely altered cell behavior like diminished capability for differentiation or polarization are frequently observed. Therefore a transfection protocol is required that is capable of transferring siRNA and plasmid DNA into macrophages without causing serious side-effects thus allowing the investigation of the effect of the siRNA or plasmid in the context of normal cell behavior. The protocol presented here provides a method for reliably and efficiently transfecting human THP-1 macrophages and monocytes with high cell vitality, high transfection efficiency, and minimal effects on cell behavior. This approach is based on Nucleofection and the protocol has been optimized to maintain maximum capability for cell activation after transfection. The protocol is adequate for adherent cells after detachment as well as cells in suspension, and can be used for small to medium sample numbers. Thus, the method presented is useful for investigating gene regulatory effects during macrophage differentiation and polarization. Apart from presenting results characterizing macrophages transfected according to this protocol in comparison to an alternative chemical method, the impact of cell culture medium selection after transfection on cell behavior is also discussed. The presented data indicate the importance of validating the selection for different experimental settings.

This protocol presents an efficient and reliable method to transfect human THP-1 macrophages with siRNA or plasmid DNA by electroporation with high transfection efficiency while maintaining high cell vitality and full macrophage capacity for differentiation and polarization.

Macrophages, as key players of the innate immune response, are at the focus of research dealing with tissue homeostasis or various pathologies. ...

Antisense Oligonucleotides as a Tool for Prolonged Knockdown of Nuclear lncRNAs in Human Cell Lines

Long noncoding RNAs (lncRNAs) play key regulatory roles in gene expression at the transcriptional level. Experimental evidence has established that a substantial fraction of lncRNA preferentially accumulates in the nucleus. For analysis of the function of nuclear lncRNAs, it is important to achieve efficient knockdown of these transcripts inside the nucleus. In contrast to the use of RNA interference, a technology that depends on the cytoplasmic silencing machinery, an antisense oligonucleotide (ASO) technology can achieve RNA knockdown by recruiting RNase H to the RNA-DNA duplexes for nuclear RNA cleavage. Unlike the use of CRISPR-Cas tools for genome engineering, where possible alterations in the chromatin state can occur, ASOs allow the efficient knockdown of nuclear transcripts without modifying the genome. Nevertheless, one of the major obstacles to ASO-mediated knockdown is its transitory effect. For the study of long-lasting effects of lncRNA silencing, maintaining efficient knockdown for a long time is needed. In this study, a protocol was developed to achieve a knockdown effect for over 21 days. The purpose was to evaluate the cis-regulatory effects of lncRNA knockdown on the adjacent coding gene RFC4, which is related to chromosomal instability, a condition that is observed only through time and cell aging. Two different human cell lines were used: PrEC, normal primary prostate epithelial cells, and HCT116, an epithelial cell line isolated from colorectal carcinoma, achieving successful knockdown in the assayed cell lines.

To analyze the function of lncRNAs in time-dependent processes such as chromosomal instability, a prolonged knockdown effect must be achieved. To that purpose, presented here is a protocol that uses modified antisense oligonucleotides to achieve effective knockdown in cell lines for 21 days.

Long noncoding RNAs (lncRNAs) play key regulatory roles in gene expression at the transcriptional level. Experimental evidence has established that a ...

Cancer Research

Production of siRNA-Loaded Lipid Nanoparticles using a Microfluidic Device

The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based RNA delivery systems, namely, RNA-loaded LNPs have attracted attention for RNA therapy. In particular, mRNA-loaded LNP vaccines were approved to prevent COVID-19, thereby leading to the paradigm shift toward the development of next-generation nanomedicines. For the LNP-based nanomedicines, the LNP size is a significant factor in controlling the LNP biodistribution and LNP performance. Therefore, a precise LNP size control technique is indispensable for the LNP production process. Here, we report a protocol for size controlled LNP production using a microfluidic device, named iLiNP. siRNA loaded LNPs are also produced using the iLiNP device and evaluated by in vitro experiment. Representative results are shown for the LNP size, including siRNA-loaded LNPs, Z-potential, siRNA encapsulation efficiency, cytotoxicity, and target gene silencing activity.

Microfluidic-based lipid nanoparticle (LNP) production methods have attracted attention in drug delivery systems (DDSs), including RNA delivery. This protocol describes the fabrication, LNP (siRNA-loaded LNP) production, and LNP evaluation processes using our original microfluidic device named iLiNP.

The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based ...

Biochemistry

MISSION esiRNA for RNAi Screening in Mammalian Cells

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as small interfering RNAs (siRNAs). The short double-stranded RNAs originate from longer double stranded precursors by the activity of Dicer, a protein of the RNase III family of endonucleases. The resulting fragments are components of the RNA-induced silencing complex (RISC), directing it to the cognate target mRNA. RISC cleaves the target mRNA thereby reducing the expression of the encoded protein1,2,3. RNAi has become a powerful and widely used experimental method for loss of gene function studies in mammalian cells utilizing small interfering RNAs.
Currently two main methods are available for the production of small interfering RNAs. One method involves chemical synthesis, whereas an alternative method employs endonucleolytic cleavage of target specific long double-stranded RNAs by RNase III in vitro. Thereby, a diverse pool of siRNA-like oligonucleotides is produced which is also known as endoribonuclease-prepared siRNA or esiRNA. A comparison of efficacy of chemically derived siRNAs and esiRNAs shows that both triggers are potent in target-gene silencing. Differences can, however, be seen when comparing specificity. Many single chemically synthesized siRNAs produce prominent off-target effects, whereas the complex mixture inherent in esiRNAs leads to a more specific knockdown10.
In this study, we present the design of genome-scale MISSION esiRNA libraries and its utilization for RNAi screening exemplified by a DNA-content screen for the identification of genes involved in cell cycle progression. We show how to optimize the transfection protocol and the assay for screening in high throughput. We also demonstrate how large data-sets can be evaluated statistically and present methods to validate primary hits. Finally, we give potential starting points for further functional characterizations of validated hits.

Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results.

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as ...

Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms

In mammalian cells, the endoplasmic reticulum (ER) plays a key role in protein biogenesis as well as in calcium signalling1. The heterotrimeric Sec61 complex in the ER membrane provides an aqueous path for newly-synthesized polypeptides into the lumen of the ER. Recent work from various laboratories suggested that this heterotrimeric complex may also form transient Ca2+ leak channels2-8. The key observation for this notion was that release of nascent polypeptides from the ribosome and Sec61 complex by puromycin leads to transient release of Ca2+ from the ER. Furthermore, it had been observed in vitro that the ER luminal protein BiP is involved in preventing ion permeability at the level of the Sec61 complex9,10. We have established an experimental system that allows us to directly address the role of the Sec61 complex as potential Ca2+ leak channel and to characterize its putative regulatory mechanisms11-13. This system combines siRNA mediated gene silencing and live cell Ca2+ imaging13. Cells are treated with siRNAs that are directed against the coding and untranslated region (UTR), respectively, of the SEC61A1 gene or a negative control siRNA. In complementation analysis, the cells are co-transfected with an IRES-GFP vector that allows the siRNA-resistant expression of the wildtype SEC61A1 gene. Then the cells are loaded with the ratiometric Ca2+-indicator FURA-2 to monitor simultaneously changes in the cytosolic Ca2+ concentration in a number of cells via a fluorescence microscope. The continuous measurement of cytosolic Ca2+ also allows the evaluation of the impact of various agents, such as puromycin, small molecule inhibitors, and thapsigargin on Ca2+ leakage. This experimental system gives us the unique opportunities to i) evaluate the contribution of different ER membrane proteins to passive Ca2+ efflux from the ER in various cell types, ii) characterize the proteins and mechanisms that limit this passive Ca2+ efflux, and iii) study the effects of disease linked mutations in the relevant components.

Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms

The endoplasmic reticulum plays a key role in protein biogenesis and in calcium homeostasis. We have established an experimental system that allows us to address the role of Ca2+ leak channels and to characterize their putative regulatory mechanisms. This system involves siRNA mediated gene silencing and live cell Ca2+ imaging.

In mammalian cells, the endoplasmic reticulum (ER) plays a key role in protein biogenesis as well as in calcium signalling1. The heterotrimeric Sec61 ...

Oct4GiP Reporter Assay to Study Genes that Regulate Mouse Embryonic Stem Cell Maintenance and Self-renewal

Pluripotency and self-renewal are two defining characteristics of embryonic stem cells (ES cells). Understanding the underlying molecular mechanism will greatly facilitate the use of ES cells for developmental biology studies, disease modeling, drug discovery, and regenerative medicine (reviewed in 1,2).
To expedite the identification and characterization of novel regulators of ES cell maintenance and self-renewal, we developed a fluorescence reporter-based assay to quantitatively measure the self-renewal status in mouse ES cells using the Oct4GiP cells 3. The Oct4GiP cells express the green fluorescent protein (GFP) under the control of the Oct4 gene promoter region 4,5. Oct4 is required for ES cell self-renewal, and is highly expressed in ES cells and quickly down-regulated during differentiation 6,7. As a result, GFP expression and fluorescence in the reporter cells correlates faithfully with the ES cell identity 5, and fluorescence-activated cell sorting (FACS) analysis can be used to closely monitor the self-renewal status of the cells at the single cell level 3,8.
Coupled with RNAi, the Oct4GiP reporter assay can be used to quickly identify and study regulators of ES cell maintenance and self-renewal 3,8. Compared to other methods for assaying self-renewal, it is more convenient, sensitive, quantitative, and of lower cost. It can be carried out in 96- or 384-well plates for large-scale studies such as high-throughput screens or genetic epistasis analysis. Finally, by using other lineage-specific reporter ES cell lines, the assay we describe here can also be modified to study fate specification during ES cell differentiation.

We describe a fluorescence reporter assay to quickly identify and characterize genes that regulate mouse embryonic stem cell maintenance and self-renewal.

Pluripotency and self-renewal are two defining characteristics of embryonic stem cells (ES cells). Understanding the underlying molecular mechanism will ...

Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death

Functional inactivation of gene expression in mammalian cells is crucial for the study of the contribution of a protein of interest to various pathways1,2. However, conditional knockdown of gene expression is required in cases when constitutive knockdown is not tolerated by cells for a long period of time3-5. Here we describe a protocol for preparation of cell lines allowing conditional knockdown of subunits of the ACF chromatin remodeling factor. These cell lines facilitate the determination of the contribution of ACF to induction of cell death by the adenovirus E4orf4 protein6. Sequences encoding short hairpin RNAs for the Acf1 and SNF2h subunits of the ACF chromatin remodeling factor were cloned next to a doxycycline-inducible promoter in a plasmid also containing a gene for the neomycin resistance gene. Neomycin-resistant cell clones were selected in the presence of G418 and isolated. The resulting cell lines were induced by doxycycline treatment, and once Acf1 or SNF2h expression levels were reduced, the cells were transfected with a plasmid encoding E4orf4 or an empty vector. To confirm the specific effect of the shRNA constructs, Acf1 or SNF2h protein levels were restored to WT levels by cotransfection with a plasmid expressing Acf1 or SNF2h which were rendered resistant to the shRNA by introduction of silent mutations. The ability of E4orf4 to induce cell death in the various samples was determined by a DAPI assay, in which the frequency of appearance of nuclei with apoptotic morphologies in the transfected cell population was measured7-9.
The protocol described here can be utilized for determination of the functional contribution of various proteins to induction of cell death by their protein partners in cases when constitutive knockdown may be cell lethal.

Contribution of the ACF chromatin remodeling factor to E4orf4-induced cell death was measured. The protocol includes selection of cell clones in which doxycycline treatment induces conditional knockdown of the ACF subunits Acf1 and SNF2h, and use of the DAPI assay to measure E4orf4-induced cell death in the inducible cell lines.

Functional inactivation of gene expression in mammalian cells is crucial for the study of the contribution of a protein of interest to various ...

Workflow for High-content, Individual Cell Quantification of Fluorescent Markers from Universal Microscope Data, Supported by Open Source Software

Advances in understanding the control mechanisms governing the behavior of cells in adherent mammalian tissue culture models are becoming increasingly dependent on modes of single-cell analysis. Methods which deliver composite data reflecting the mean values of biomarkers from cell populations risk losing subpopulation dynamics that reflect the heterogeneity of the studied biological system. In keeping with this, traditional approaches are being replaced by, or supported with, more sophisticated forms of cellular assay developed to allow assessment by high-content microscopy. These assays potentially generate large numbers of images of fluorescent biomarkers, which enabled by accompanying proprietary software packages, allows for multi-parametric measurements per cell. However, the relatively high capital costs and overspecialization of many of these devices have prevented their accessibility to many investigators.
Described here is a universally applicable workflow for the quantification of multiple fluorescent marker intensities from specific subcellular regions of individual cells suitable for use with images from most fluorescent microscopes. Key to this workflow is the implementation of the freely available Cell Profiler software1&#160;to distinguish individual cells in these images, segment them into defined subcellular regions and deliver fluorescence marker intensity values specific to these regions. The extraction of individual cell intensity values from image data is the central purpose of this workflow and will be illustrated with the analysis of control data from a siRNA screen for G1 checkpoint regulators in adherent human cells. However, the workflow presented here can be applied to analysis of data from other means of cell perturbation (e.g., compound screens) and other forms of fluorescence based cellular markers and thus should be useful for a wide range of laboratories.

Presented is a flexible informatics workflow enabling multiplexed image-based analysis of fluorescently labeled cells. The workflow quantifies nuclear and cytoplasmic markers and computes marker translocation between these compartments. Procedures are provided for perturbation of cells using siRNA and reliable methodology for marker detection by indirect immunofluorescence in 96-well formats.

Advances in understanding the control mechanisms governing the behavior of cells in adherent mammalian tissue culture models are becoming increasingly ...

Adenofection: A Method for Studying the Role of Molecular Chaperones in Cellular Morphodynamics by Depletion-Rescue Experiments

Cellular processes such as mitosis and cell differentiation are governed by changes in cell shape that largely rely on proper remodeling of the cell cytoskeletal structures. This involves the assembly-disassembly of higher-order macromolecular structures at a given time and location, a process that is particularly sensitive to perturbations caused by overexpression of proteins. Methods that can preserve protein homeostasis and maintain near-to-normal cellular morphology are highly desirable to determine the functional contribution of a protein of interest in a wide range of cellular processes. Transient depletion-rescue experiments based on RNA interference are powerful approaches to analyze protein functions and structural requirements. However, reintroduction of the target protein with minimum deviation from its physiological level is a real challenge. Here we describe a method termed adenofection that was developed to study the role of molecular chaperones and partners in the normal operation of dividing cells and the relationship with actin remodeling. HeLa cells were depleted of BAG3 with siRNA duplexes targeting the 3&#39;UTR region. GFP-tagged BAG3 proteins were reintroduced simultaneously into &#62;75% of the cells using recombinant adenoviruses coupled to transfection reagents. Adenofection enabled to express BAG3-GFP proteins at near physiological levels in HeLa cells depleted of BAG3, in the absence of a stress response. No effect was observed on the levels of endogenous Heat Shock Protein chaperones, the main stress-inducible regulators of protein homeostasis. Furthermore, by adding baculoviruses driving the expression of fluorescent markers at the time of cell transduction-transfection, we could dissect mitotic cell dynamics by time-lapse microscopic analyses with minimum perturbation of normal mitotic progression. Adenofection is applicable also to hard-to-infect mouse cells, and suitable for functional analyses of myoblast differentiation into myotubes. Thus adenofection provides a versatile method to perform structure-function analyses of proteins involved in sensitive biological processes that rely on higher-order cytoskeletal dynamics.

We describe a method for depletion-rescue experiments that preserves cellular integrity and protein homeostasis. Adenofection enables functional analyses of proteins within biological processes that rely on finely tuned actin-based dynamics, such as mitotic cell division and myogenesis, at the single-cell level.

Cellular processes such as mitosis and cell differentiation are governed by changes in cell shape that largely rely on proper remodeling of the cell ...

Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells

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