Name: scratch migration assay and dorsal skinfold chamber for in vitro and in vivo analysis of wound healing
Uploaded: 2019-09-26T13:00:00
Description: Watch this Scientific Journal Video about Scratch Migration Assay and Dorsal Skinfold Chamber for In Vitro and In Vivo Analysis of Wound Healing at JoVE.com

We thank Dr. Petra Weissgerber and the Transgene Unit of the SPF animal facility (project P2 of SFB 894) of the Medical Faculty and the animal facility at the Institute of Clinical and Experimental Surgery at the Medical Faculty of Saarland University, Homburg. We thank Dr. Andreas Beck for critical reading of the manuscript. This study was funded by the Deutsche Forschungsgemeinschaft (DFG) Sonderforschungsbereich (SFB) 894, project A3 to A.B. and V.F.).

All experimental procedures were approved and performed in accordance with the ethics regulations and the animal welfare committees of Saarland and Saarland University.
1 Primary cell culture and siRNA transfection
NOTE: In the described method, primary fibroblasts are used. These cells play a crucial role in wound healing and tissue remodeling11. In this experiment, the Cacnb3 gene, encoding the Cav&#946;3 subunit of high voltage-gate...

<ol>
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In this manuscript, we describe an in vitro and in vivo wound healing assay and correlate the results obtained. For the in vitro assay, we used primary mouse fibroblasts4,14,15 which play an important role in wound healing and tissue remodeling11. Other adherent cell types growing as monolayers (e.g., epithelial cells, endothelial cells, keratinocytes) can be used as well. Plating the same number of viabl...

Skin wound healing starts immediately after the skin injury in order to restore the skin&#39;s integrity and to protect the organism from infections. The wound healing process goes through four overlapping phases; coagulation, inflammation, new tissue formation, and tissue remodeling1. Cell migration is crucial during these phases. Inflammatory cells, immune cells, keratinocytes, endothelial cells, and fibroblasts are activated at different time points and invade the wound area2. Methods to investigate wound healing in vitro and in vivo are of great interest not only to understand the underlying mechanisms but also to test new drugs and to develop new strategies aiming to ameliorate and accelerate skin wound healing.
To monitor and analyze cell migration, the scratch migration assay can be used. It is often referred to as in vitro wound healing assay. This method requires a cell culture facility3. It is a simple procedure, there is no need of high-end equipment and the assay can be performed in most cell biology laboratories. In this assay, a cell-free area is created by the mechanical disruption of a confluent cell monolayer, preferably epithelial- or endothelial-like cells or fibroblasts. Cells on the edge of the scratch will migrate in order to repopulate the created gap. Quantification of the decreasing cell-free area over time resembles the migration rate and indicates the time, which the cells need to close the gap. For this purpose, investigators can use either acutely isolated cells from WT mice or mice lacking a gene of interest4, or immortalized cells available from reliable cell repositories. The scratch assay allows studying the influence of pharmacologically active compounds or the effect of transfected cDNAs or siRNAs on cell migration.
In vivo, wound healing is a complex physiological process, requiring different cell types including keratinocytes, inflammatory cells, fibroblasts, immune cells and endothelial cells in order to restore the skin&#8217;s physical integrity as fast as possible1. Different methods to study in vivo wound healing have been developed and used in the past5,6,7,8. The dorsal skinfold chamber described in this article was previously used for wound healing assays9. It is used as a modified dorsal skinfold chamber preparation for mice. The modified skinfold chamber model has several advantages. 1) It minimizes skin contraction, which prevents observing the wound healing process and might influence wound repair in mice. 2) This chamber makes use of covering the wound with a glass coverslip, reducing tissue infections and desiccation, which could delay the healing process. 3) Blood flow and vascularization can be directly monitored. 4) It allows repetitive topical application of pharmacologically active compounds and reagents in order to treat the wound and accelerate healing9,10.
We identified the &#946;3 subunit of high voltage-gated calcium channels (Cav&#946;3) as a potential target molecule to influence skin wound healing using two independent protocols, i.e., the in vitro scratch migration assay and the in vivo dorsal skinfold chamber model. For the in vitro assay, we used primary fibroblasts, these cells do express the Cacnb3 gene encoding the Cav&#946;3 protein but lack depolarization-induced Ca2+ influx or voltage-dependent Ca2+ currents. We described a novel function of Cav&#946;3 in these fibroblasts: Cav&#946;3 binds to the inositol 1,4,5-trisphosphate receptor (IP3R) and constraints calcium release from the endoplasmic reticulum. Deletion of the Cacnb3 gene in mice leads to increased sensitivity of the IP3R for IP3, enhanced cell migration and increased skin wound repair4.

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		<tr>
			<td>0.9 % NaCl</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1 ml syringes</td>
			<td>BD Plastipak</td>
			<td>303172</td>
			<td></td>
		</tr>
		<tr>
			<td>6 well plate</td>
			<td>Corning</td>
			<td>3516</td>
			<td></td>
		</tr>
		<tr>
			<td>Biopsy punch</td>
			<td>Kai Industries</td>
			<td>48201</td>
			<td>2 mm</td>
		</tr>
		<tr>
			<td>Cacnb3 Mouse siRNA Oligo Duplex (Locus ID 12297)</td>
			<td>Origene</td>
			<td>SR415626</td>
			<td></td>
		</tr>
		<tr>
			<td>Depilation cream</td>
			<td></td>
			<td></td>
			<td>any depilation cream</td>
		</tr>
		<tr>
			<td>Dexpanthenol 5% (BEPANTHEN)</td>
			<td>Bayer</td>
			<td>3400935940179.00</td>
			<td>(BEPANTHEN)</td>
		</tr>
		<tr>
			<td>Dihydroxylidinothiazine hydrochloride (Xylazine)</td>
			<td>Bayer Health Care</td>
			<td></td>
			<td>Rompun 2%</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium (DMEM)</td>
			<td>Gibco by life technologies</td>
			<td>41966-029</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Gibco by life technologies</td>
			<td>10270-106</td>
			<td></td>
		</tr>
		<tr>
			<td>Hexagon full nut</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine hydrochloride</td>
			<td>Zoetis</td>
			<td></td>
			<td>KETASET</td>
		</tr>
		<tr>
			<td>Light microscope</td>
			<td>Keyence, Osaka, Japan</td>
			<td>BZ-8000</td>
			<td>Similar microscopes might be used</td>
		</tr>
		<tr>
			<td>Lipofectamine RNAiMAX Transfection Reagent</td>
			<td>Thermo Fisher Scientific</td>
			<td>13778075</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-forceps</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-Scissors</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse restrainer</td>
			<td>Home-made</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Normal scissors</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Objective</td>
			<td>Nikon</td>
			<td>plan apo 10x/0.45</td>
			<td></td>
		</tr>
		<tr>
			<td>Opti-MEM</td>
			<td>Gibco by life technologies</td>
			<td>51985-026</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene sutures</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Screwdriver</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Skin disinfectant (octeniderm)</td>
			<td>Sch&#252;lke &#38; Mayr GmbH</td>
			<td>118212</td>
			<td></td>
		</tr>
		<tr>
			<td>Slotted cheese head screw</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Snap ring</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Snap ring plier</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical microscope with camera</td>
			<td>Leica</td>
			<td>Leica M651</td>
			<td></td>
		</tr>
		<tr>
			<td>Titanium frames for the skinfold chamber</td>
			<td>IROLA</td>
			<td>160001</td>
			<td>Halteblech M</td>
		</tr>
		<tr>
			<td>Wire piler</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
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scratch migration assay and dorsal skinfold chamber for in vitro and in vivo analysis of wound healing

Impaired cutaneous wound healing is a major concern for patients suffering from diabetes and for elderly people, and there is a need for an effective treatment. Appropriate in vitro and in vivo approaches are essential for the identification of new target molecules for drug treatments to improve the skin wound healing process. We identified the &#946;3 subunit of voltage-gated calcium channels (Cav&#946;3) as a potential target molecule to influence the wound healing in two independent assays, i.e., the in vitro scratch migration assay and the in vivo dorsal skinfold chamber model. Primary mouse embryonic fibroblasts (MEFs) acutely isolated from wild-type (WT) and Cav&#946;3-deficient mice (Cav&#946;3 KO) or fibroblasts acutely isolated from WT mice treated with siRNA to down-regulate the expression of the Cacnb3 gene, encoding Cav&#946;3, were used. A scratch was applied on a confluent cell monolayer and the gap closure was followed by taking microscopic images at defined time points until complete repopulation of the gap by the migrating cells. These images were analyzed, and the cell migration rate was determined for each condition. In an in vivo assay, we implanted a dorsal skinfold chamber on WT and Cav&#946;3 KO mice, applied a defined circular wound of 2 mm diameter, covered the wound with a glass coverslip to protect it from infections and desiccation, and monitored the macroscopic wound closure over time. Wound closure was significantly faster in Cacnb3-gene-deficient mice. Because the results of the in vivo and the in vitro assays correlate well, the in vitro assay may be useful for the high-throughput screening before validating the in vitro hits by the in vivo wound healing model. What we have shown here for wild-type and Cav&#946;3-deficient mice or cells might also be applicable for specific molecules other than Cav&#946;3.

The scratch assay was performed on a confluent cell monolayer of wild-type and &#946;3-deficient MEFs (Figure 1c). After performing the &#34;scratch&#34;&#160;using a 200 &#956;L pipette tip, cells from both genotypes migrate into the scratch area and close the gap. Images were taken after 6, 10 and 30 h (Figure 1a). Cell migration was quantified as the percentage (%) of scratch area repopulated by migrating cells 6 hours after ...

Watch this Scientific Journal Video about Scratch Migration Assay and Dorsal Skinfold Chamber for In Vitro and In Vivo Analysis of Wound Healing at JoVE.com

Scratch Migration Assay and Dorsal Skinfold Chamber for In Vitro and In Vivo Analysis of Wound Healing

Here, we present a protocol for an in vitro scratch assay using primary fibroblasts and for an in vivo skin wound healing assay in mice. Both assays are straightforward methods to assess in vitro and in vivo wound healing.

Impaired cutaneous wound healing is a major concern for patients suffering from diabetes and for elderly people, and there is a need for an effective ...

The insurgent need for treatment of skin wounds. To identify your target molecules for drug treatments, in vitro and in vivo test systems are required. Appropriate systems are the in vitro scratch assay, and the in vivo dorsal skin fold chamber.Both are straight forward procedures for monitoring cell migration and skin wound healing, in the absence and presence of pharmacologically active compounds. Although both techniques are straight forward, investigators should practice the scratch application. And the dorsal skin fold chamber implantation, and wounding to obtain reliable and reproducible results.Demonstration of the procedures will be done by Dr.Matthias Laschke, a surgeon and professor from the institute of clinical and experimental surgery. Before beginning the procedure, use an ultra fine permanent marker to mark one six well plate per cell type, with a horizontal line at the bottom of each well to delineate the scratch region for each culture. Next plate primary fiber blasts isolated from wild type and beta 3 deficient mice, in a six well plate at a 5 times 10 to the fifth fiber blasts per well concentration.In 2mL of DMEM supplemented with 10%fetal bovine serum. Label the plates with the cell type, genotype and date. And place the plates in the cell culture incubator for 24 hours.The next morning add 9 micro liters of each lipid based transfection reagent of interest, to individual micro centrifuge tubes containing 150 micro liters of reduced serum medium per tube. Add 1.5 micro liters of siRNA to a second micro centrifuge tube per transfection reagent containing 150 micro liters of reduced serum medium per tube. And mix each siRNA solution with a single tube of transfection reagent solution.After briefly vortexing place the mixtures at 21 degrees Celsius for 5 minutes. During the incubation carefully replace the supernate in each well. With 2.25mL of fresh culture medium down the side of the wells.At the end of the incubation add 250 micro liters of the appropriate siRNA transfection reagent mixture, drop wise into each corresponding well of cells. And return the plates to the cell culture incubator for 72 hours. When the cells have reached 100%confluency, discard the culture supernatant from each well.And use a 200 micro liter pipette tip to create scratch in the confluent cell monolayer. Vertical to the marked horizontal line at the bottom of each well. Then carefully rinse each wounded well 2 times with 2mL of PPS per wash.To remove any released factors from the damaged cells, loose cells or debris from the scratched area. After the second wash add 2mL of fresh cell culture medium supplemented with 1 or 10 percent serum to each well. And capture images of the wounds in each plate on the stage of a light microscope.Immediately after scratching at a 10X magnification. Then return the plate to the cell culture incubator. Continuing to capture images at the appropriate experimental time points for the next 30 hours.At the end of the experiment quantify the initial cell free area and remaining area after 6, 10 and 30 hours of culture. To determine the percentage of the scratch area repopulated by the migrating cells relative to the initial scratch area. After confirming a lack of response to toe pinch, in the wild type or beta three knockout C57 black six mouse, carefully shave the dorsum.And apply ointment to the animal's eyes. Apply depilatory cream to eliminate any remaining hair. Removing the cream after 10 minutes.To prepare the titanium chamber, fix one part of the symmetrical titanium chamber frame, with the connecting screws with nuts. To maintain 400 to 500 micrometers between the two symmetrical parts of the chamber. To avoid compression of the blood vesicles in the skin.Disinfect the exposed skin with 70%ethanol. And grasp a fold of skin in front of a light source. Position the middle line of the double layer of skin to where the titanium chamber will be implanted.And cranially and caudally fix the skin fold with a polypropylene suture. Tighten the other side of the suture on a metal rack to lift the folded skin. And adjust the height of the rack to allow the mouse to sit comfortably.Suture the first frame of the titanium chamber by polypropylene sutures on it superior edge to the back of the dorsal skin fold. After reconfirming sedation use fine scissors to make small incisions in the skin. And pass the two connecting screws attached to the first half of the titanium chamber through the base of the skin fold.Remove the mouse from the rack, and place the animal in a lateral position. Place the second complimentary half of the titanium chamber on top of the 3 connecting screws. And manually apply slight pressure to pass these screws through the second half of the titanium frame.The folded skin layer is now sandwiched between the two symmetrical halves of the titanium frame. Then fix both symmetrical parts with stainless steel nuts. Using a standardized 2mL diameter biopsy punch, mark the wound area in the center of the skin, within the observation window of the skin fold chamber.And use fine forceps and scissors to remove the entire epidermis and dermis within the mark. To create a circular wound. Clean the 3 and a half to 4 and a half milometer squared wound with 0.5mL of steril saline.And cover the wound with a glass coverslip. Use the snap ring plier on the titanium chamber to fix the coverslip in place. And immediately transfer the mouse to the imaging stage of a stereomicroscope.Then image the wound at a 40X magnification. Before placing the mouse into a cage with monitoring until full recovery. After creating a scratch using a 200 micro liter pipette tip as demonstrated, in this representative experiment, cells from both genotypes migrated into the scratch area and closed the gap.The cell migration was then quantified as the percentage of scratch area repopulated by migrating cells 6 hours after performing the scratch. For example in this experiment migrating Cav beta 3 deficient fiber blasts closed the scratch area significantly earlier than fiber blasts from wild type mice. To confirm the Cav beta 3 dependent effect observed in Cav beta 3 deficient fiber blasts, wild type fiber blasts were transfected with siRNA to down regulate the Cav beta 3 protein.Fiber blasts treated with the Cav beta 3 specific siRNAs behaved like beta 3 deficient fiber blasts. To compare skin wound healing between both genotypes, the wound area in the skin fold chamber was photographed directly after wounding. And the wound was imaged over the next 2 weeks.The sizes of the wounds were measured on the images and the wound area, on a given day was expressed as, the percentage of the initial wound area. As expected the rate of wound closure was increased in Cav beta 3 deficient mice compared to wild type controls. Be sure to apply equal pressure to the pipette tip, for each scratch and to match the scratches to the marked lines on the plate bottom as closely as possible.The observation window of the dorsal skin fold chamber can be opened at anytime during the healing process. Allowing for the topical application of different pharmacologically active compounds. It is also possible to excise the wounded area at different stages of the healing process.For molecular protein biochemical or histological analysis.

scratch-migration-assay-dorsal-skinfold-chamber-for-vitro-vivo

Research

JoVE Journal

Medicine

Murine Model of Wound Healing

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. Impaired wound healing, which occurs in diabetic patients for example, can lead to severe unfavorable outcomes such as amputation. There is, therefore, an increasing impetus to develop novel agents that promote wound repair. The testing of these has been limited to large animal models such as swine, which are often impractical. Mice represent the ideal preclinical model, as they are economical and amenable to genetic manipulation, which allows for mechanistic investigation. However, wound healing in a mouse is fundamentally different to that of humans as it primarily occurs via contraction. Our murine model overcomes this by incorporating a splint around the wound. By splinting the wound, the repair process is then dependent on epithelialization, cellular proliferation and angiogenesis, which closely mirror the biological processes of human wound healing. Whilst requiring consistency and care, this murine model does not involve complicated surgical techniques and allows for the robust testing of promising agents that may, for example, promote angiogenesis or inhibit inflammation. Furthermore, each mouse acts as its own control as two wounds are prepared, enabling the application of both the test compound and the vehicle control on the same animal. In conclusion, we demonstrate a practical, easy-to-learn, and robust model of wound healing, which is comparable to that of humans.

A murine model of cutaneous wound healing that can be used to assess therapeutic compounds in physiological and pathophysiological settings.

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. ...

Murine Endoscopy for In Vivo Multimodal Imaging of Carcinogenesis and Assessment of Intestinal Wound Healing and Inflammation

Mouse models are widely used to study pathogenesis of human diseases and to evaluate diagnostic procedures as well as therapeutic interventions preclinically. However, valid assessment of pathological alterations often requires histological analysis, and when performed ex vivo, necessitates death of the animal. Therefore in conventional experimental settings, intra-individual follow-up examinations are rarely possible. Thus, development of murine endoscopy in live mice enables investigators for the first time to both directly visualize the gastrointestinal mucosa and also repeat the procedure to monitor for alterations. Numerous applications for in vivo murine endoscopy exist, including studying intestinal inflammation or wound healing, obtaining mucosal biopsies repeatedly, and to locally administer diagnostic or therapeutic agents using miniature injection catheters. Most recently, molecular imaging has extended diagnostic imaging modalities allowing specific detection of distinct target molecules using specific photoprobes. In conclusion, murine endoscopy has emerged as a novel cutting-edge technology for diagnostic experimental in vivo imaging and may significantly impact on preclinical research in various fields.

Murine Endoscopy for In Vivo Multimodal Imaging of Carcinogenesis and Assessment of Intestinal Wound Healing and Inflammation

Small animal imaging techniques allow serial diagnostic examinations and therapeutic interventions in vivo. Recently, the scope of applications has significantly widened and currently includes assessment of colonic tumor development, wound healing and monitoring of inflammation. This protocol illustrates these diverse potential applications of murine endoscopy.

Mouse models are widely used to study pathogenesis of human diseases and to evaluate diagnostic procedures as well as therapeutic interventions ...

Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are still occurring, particularly in reconstructive flap surgery. Multiple experimental flap models have been developed to analyze underlying causes and mechanisms and to investigate treatment strategies to prevent ischemic complications. The limiting factor of most models is the lacking possibility to directly and repetitively visualize microvascular architecture and hemodynamics. The goal of the protocol was to present a well-established mouse model affiliating these before mentioned lacking elements. Harder et al. have developed a model of a musculocutaneous flap with a random perfusion pattern that undergoes acute persistent ischemia and results in ~50% necrosis after 10 days if kept untreated. With the aid of intravital epi-fluorescence microscopy, this chamber model allows repetitive visualization of morphology and hemodynamics in different regions of interest over time. Associated processes such as apoptosis, inflammation, microvascular leakage and angiogenesis can be investigated and correlated to immunohistochemical and molecular protein assays. To date, the model has proven feasibility and reproducibility in several published experimental studies investigating the effect of pre-, peri- and postconditioning of ischemically challenged tissue.

The window of the murine dorsal skinfold chamber presented visualizes a zone of acute persistent ischemia of a musculocutaneous flap. Intravital epi-fluorescence microscopy permits for direct and repetitive assessment of the microvasculature and quantification of hemodynamics. Morphologic and hemodynamic results can further be correlated with histological and molecular analyses.

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic study in the liver. Here, numerous assays are described to comprehensively measure the phenotype and parameters of hepatic steatosis in mouse and hepatocyte models. 
Combining the physiological, histological, and biochemical methods, this system can be used to assess the progress of hepatic steatosis. In vivo, the measurements of body weight and nuclear magnetic resonance (NMR) provide a general understanding of mice in a non-invasive manner. Hematoxylin and Eosin (H&amp;E) and Oil Red O staining determine the histological morphology and lipid deposition of liver tissue under nutrient overload conditions, such as high-fat diet feeding. Next, the total lipid contents are isolated by chloroform/methanol extraction, which are followed by a biochemical analysis for triglyceride and cholesterol. Moreover, mouse primary hepatocytes are treated with high glucose plus insulin to stimulate lipid accumulation, an efficient in vitro model to mimic diet-induced hyperglycemia and hyperinsulinemia in vivo. Then, the lipid deposition is measured by Oil Red O staining and chloroform/methanol extraction. Oil Red O staining determines intuitive hepatic steatotic phenotypes, while the lipid extraction analysis determines the parameters that can be analyzed statistically. The present protocols are of interest to scientists in the fields of fatty liver diseases, insulin resistance, and type 2 diabetes.

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Here, optimized methods to generate in vivo and in vitro models of hepatic steatosis and to analyze the steatotic phenotypes and related physiological parameters are described.

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic ...

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During In Vitro Wound Healing

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated experimental procedures, while potentially lacking in precision. In vitro culture of epithelial cell lines provides a suitable platform for researching the cell migratory behavior in wound healing and the impact of treatments on these cells. The physiology of epithelial cells is often studied in non-confluent conditions; however, this approach may not resemble natural wound healing conditions. Disrupting the epithelium integrity by mechanical means generates a realistic model, but may impede the application of molecular techniques. Consequently, microscopy based techniques are optimal for studying epithelial cell migration in vitro. Here we detail two specific methods, the artificial wound scratch assay and the artificial migration front assay, that can obtain quantitative and qualitative data, respectively, on the migratory performance of epithelial cells.

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During  In Vitro Wound Healing

This manuscript describes how incision-like lesions made on cultured epithelial cell monolayers conveniently model wound healing in vitro, allowing for imaging by confocal or laser scanning microscopy, and which can provide high-quality quantitative and qualitative data for studying both cell behavior and the mechanisms involved in migration.

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated ...

Corneal Epithelial Abrasion with Ocular Burr As a Model for Cornea Wound Healing

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to injury. In fact, the most common type of eye injury found in clinic is a corneal abrasion. Here, we utilize an ocular burr to induce an abrasion resulting in removal of the corneal epithelium in vivo on anesthetized mice. This method allows for targeted and reproducible epithelial disruption, leaving other areas intact. In addition, we describe the visualization of the abraded epithelium with fluorescein staining and provide concrete advice on how to visualize the abraded cornea. Then, we follow the timeline of wound healing 0, 18, and 72 h after abrasion, until the wound is re-epithelialized. The epithelial abrasion model of corneal injury is ideal for studies on epithelial cell proliferation, migration and re-epithelialization of the corneal layers. However, this method is not optimal to study stromal activation during wound healing, because the ocular burr does not penetrate to the stromal cell layers. This method is also suitable for clinical applications, for example, pre-clinical test of drug effectiveness.

This protocol describes a method to inflict an abrasion to the ocular surface of the mouse, and to follow the wound healing process thereafter. The protocol takes advantage of an ocular burr to partially remove the surface epithelium of the eye in anaesthetized mice.

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to ...

Ex Vivo Corneal Organ Culture Model for Wound Healing Studies

The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two dimensional (2D) and three dimensional (3D) culture has generated a wealth of information not only about corneal biology but also about wound healing, myofibroblast biology, and scarring in general. The goal of the protocol is an assay system for quantifying myofibroblast development, which characterizes scarring. We demonstrate a corneal organ culture ex vivo model using pig eyes. In this anterior keratectomy wound, corneas still in the globe are wounded with a circular blade called a trephine. A plug of approximately 1/3 of the anterior cornea is removed including the epithelium, the basement membrane, and the anterior part of the stroma. After wounding, corneas are cut from the globe, mounted on a collagen/agar base, and cultured for two weeks in supplemented-serum free medium with stabilized vitamin C to augment cell proliferation and extracellular matrix secretion by resident fibroblasts. Activation of myofibroblasts in the anterior stroma is evident in the healed cornea. This model can be used to assay wound closure, the development of myofibroblasts and fibrotic markers, and for toxicology studies. In addition, the effects of small molecule inhibitors as well as lipid-mediated siRNA transfection for gene knockdown can be tested in this system.

A protocol for an ex vivo corneal organ culture model useful for wound healing studies is described. This model system can be used to assess the effects of agents to promote regenerative healing or drug toxicity in an organized 3D multicellular environment.

The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two ...

Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the lower extremities, hyperhidrosis, etc. It is commonly practiced to position the puncture needle tip in front of the anterior fascia of the psoas major muscle and inject the inactivating agent around the sympathetic trunk, which is defined as conventional CLS. Although relatively rare, ureteropelvic damage is the most frequently reported complication of conventional CLS and can cause serious harm to patients. We found that injecting the inactivating agent behind the anterior fascia, which only targets gray rami communicantes, helped achieve therapeutic efficacy in&#160;vasodilation, sweat reduction, and pain relief comparable to conventional CLS, and serious complications were largely reduced. We define this procedure as selective CLS. Here, we present a protocol of selective CLS. The precise needle tract and accurate evaluation of the spreading of the contrast agent are critical to ensure that the drug is injected behind the anterior fascia of the psoas major muscle. The needle tip is at approximately one-third the dividing line of the vertebral body in the lateral view of a lumbar X-ray. The contrast is mainly confined around the needle tip and spreads outward and downward along the psoas muscle fibers. In this way, the anterior fascia provides a natural barrier for the ureteropelvic area, and the psoas major muscle provides a natural barrier for the lumbar nerve root. There are several highlights of this article, including 1) a detailed description of the selective CLS procedures, 2) an explanation of the anatomical basis for the implementation of selective CLS, and 3) an explanation of the differences between selective and conventional CLS.

We present a protocol for selective chemical lumbar sympathectomy (CLS), which inactivates only gray rami communicantes and not the sympathetic trunk. Selective CLS can help achieve therapeutic efficacy in vasodilation, sweat reduction, and pain relief that are comparable to conventional CLS, and serious complications, particularly ureteropelvic damages, can be reduced.

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the ...

On-Site Sampling and Extraction of Brain Tumors for Metabolomics and Lipidomics Analysis

Despite the variety of tools available for cancer diagnosis and classification, methods that enable fast and simple characterization of tumors are still in need. In recent years, mass spectrometry has become a method of choice for untargeted profiling of discriminatory compound as potential biomarkers of a disease. Biofluids are generally considered as preferable matrices given their accessibility and easier sample processing while direct tissue profiling provides more selective information about a given cancer. Preparation of tissues for the analysis via traditional methods is much more complex and time-consuming, and, therefore, not suitable for fast on-site analysis. The current work presents a protocol combining sample preparation and extraction of small molecules on-site, immediately after tumor resection. The sampling device, which is of the size of an acupuncture needle, can be inserted directly into the tissue and then transported to the nearby laboratory for instrumental analysis. The results of metabolomics and lipidomics analyses demonstrate the capability of the approach for the establishment of phenotypes of tumors related to the histological origin of the tumor, malignancy, and genetic mutations, as well as for the selection of discriminating compounds or potential biomarkers. The non-destructive nature of the technique permits subsequent performance of routinely used tests e.g., histological tests, on the same samples used for SPME analysis, thus enabling attainment of more comprehensive information to support personalized diagnostics.

The manuscript presents on-site sampling of human brain tumors with solid phase microextraction followed by their biochemical profiling towards the discovery of biomarkers.

Despite the variety of tools available for cancer diagnosis and classification, methods that enable fast and simple characterization of tumors are still ...