The current study was supported by Shanghai Innovation Funding (1402H294300) sponsored by the Science and Technology Commission of Shanghai Municipality (CN) to Dr. Wen Wang. We would like to thank Dr. Guangdong Zhou (National Tissue Engineering Center of China) for his technical assistance and scientific advice for this manuscript. We would also like to thank Mr. Huitang Xia (Shanghai Ninth People&#8217;s Hospital) for his help in animal welfare.

Procedures involving animal subjects were approved by the local Institutional Animal Care and Ethics Committee, with an effort to minimize animal suffering. The following protocol was approved by the Institutional Animal Care and Use Committee (IACUC) at Shanghai Ninth People&#8217;s Hospital affiliated to Shanghai JiaoTong University School of Medicine with the protocol number [2017]063.
1. Establishment of a Surgically-Induced Rat Knee Osteoarthritis Model
<ol>
	<li>For this surgical procedure, use 8 - 12 week old male Sprague Dawley (SD) rats with a body weight between 250 and 300 g.</li>
	<li>Anesthetize the animals with 40 mg/kg tiletamine and 40 mg/kg zolazepam via intramuscular injection.</li>
	<li>Place the animal in a left lateral position on a heated stage. Shave the right knee thoroughly with a razor. Disinfect the surgical area with 10% providone-iodine solution followed by 70% ethanol, repeat two more times and then paint with 10% providone-iodine solution and cover the non-surgical area with a surgical pad.</li>
	<li>Using a surgical scalpel, make a 2 cm incision laterally along the patellar tendon to expose the jointcapsules.</li>
	<li>Use a surgical scalpel to transect the medial collateral ligament. Reflect the meniscus toward the femur.</li>
	<li>Drip sterile 0.9% sodium chloride solution on the surface of articular cartilage during the operation to prevent the cartilage from drying out.</li>
	<li>Grab the medial meniscus with forceps and cut through the meniscus at its narrowest point from the tibial attachment with a scalpel (Figure 1A). Avoid injuring the cartilage.</li>
	<li>Close the joint capsule with a 4 - 0 absorbable suture.</li>
	<li>Monitor the surgical rats until they regain consciousness.</li>
	<li>Inject 20 mg/kg gentamicin to prevent infection and 0.05 mg/kg buprenorphine through an intramuscular route to relieve pain after surgery.</li>
	<li>Maintain the rats in a temperature-controlled animal facility under a 12 h light/dark cycle for 3 - 8 weeks to onset KOA. Animals continue to receive pain medication, including but not limited to Buprenorphine (0.05 mg/kg, i.m.) and Gentamicin (20 mg/kg, i.m.), if pain symptoms persist.</li>
</ol>
2. Histology Assessment of Rat KOA Model
<ol>
	<li>Sacrifice the rats with excessive CO2 inhalation (Add a fill rate of about 30% of the chamber volume per minute with carbon dioxide to the existing air in the chamber to make the animal unconsciousness within 2-3 min. Maintain CO2 flow for a minimum of 1 min after respiration ceases.) at indicated time points (representative results are shown at 8 weeks of KOA induction ranging from 3 to 8 weeks) after the surgery.&#160;</li>
	<li>Dissect the skin and muscle around the knee joints and cut off the knee joints with a scalpel.</li>
	<li>Fix the knee joints in 4% paraformaldehyde (PFA) for 3 days at room temperature. Afterwards, decalcify the samples in 20% ethylenediaminetetraacetic acid (EDTA) for about 4 weeks at 4 &#176;C, and change the EDTA every 3 days. 
	Caution: Paraformaldehyde is toxic, wear appropriate personal protective equipment (PPE), such as gloves and eyeglasses.</li>
	<li>Dehydrate the samples using an automatic tissue processor. Set the menu to start a flush cycle as follows: 70% ethanol for 1 h; then 80% ethanol and 95% ethanol for 1 h respectively; followed by 2 cycles of 100% ethanol for 1 h; subsequently, xylene twice for 1 h each time and paraffin 3 times at 58 &#176;C for 1 h each time. 
	Caution: Xylene is toxic, so wear appropriate PPE, such as gloves and eyeglasses. 
	NOTE: Optionally, use Coplin Jars for manual dehydration with the same set-up as the automatic tissue processor.</li>
	<li>Place the medial aspect of the intact joint face down and embed it into the paraffin block with tissue embedded into the center. 
	NOTE: Optionally, use forceps to embed the samples into the paraffin block manually.</li>
	<li>Start to cut 5 &#181;m sagittal sections from the medial margin of the joint for 30 &#181;m intervals with 2 serial sections by rotary microtome.</li>
	<li>Mount sections on glass slides and deparaffinize the slides in xylene. Between the 2 serial sections, stain one slide with Hematoxylin &#38; Eosin (H&#38;E) staining: 0.1% Hematoxylin for 15 min, 1% Acetic Acid Solution for 10 s and 0.5% Eosin for 10 min. And stain the other slide with Safranin O/Fast Green staining: 0.1% Hematoxylin for 15 min, 0.02% Fast Green for 3 min, 1% Acetic Acid Solution for 10 s and 0.1% Safranin O for 3 min. 
	Caution: Xylene is toxic, wear appropriate PPE, such as gloves, eyeglasses.</li>
	<li>Score the stained slides using Osteoarthritis Research Society International (OARSI) Histopathology Assessment System in rats6.</li>
</ol>
3. Labelling of Human Mesenchymal Stem Cells with the Fluorescent Dye DiD
<ol>
	<li>Prepare DiD cell-labeling solution in 100% ethanol at a concentration of 1 mM. Protect the cell-labeling solution from light and store it at room temperature up for 6 months.</li>
	<li>Grow haMSCs with standard cell culture procedures in Dulbecco&#39;s modified Eagle&#39;s medium (DMEM) supplemented with 1% penicillin and streptomycin and 10% fetal calf serum (FCS) in a 10 cm petri dish.</li>
	<li>Detach haMSCs with 2 mL 0.25% trypsin with 1 mM EDTA prior to around 80% confluence.</li>
	<li>Neutralize trypsin with 4 mL culture medium and spin the cells at 800 x g for 3 min at room temperature.</li>
	<li>Suspend the cells at a density of 1 x 106 cells/mL in 5 mL serum-free culture medium.</li>
	<li>Label the cells by adding 50 &#181;L DiD cell-labeling solution in 5 mL serum-free culture medium at 37 &#176;C for 50 min.</li>
	<li>Spin the labeled cells at 800 x g for 3 min.</li>
	<li>Wash the cells two more times with 5 mL phosphate buffer saline (PBS) at 800 x g for 3 min each.</li>
	<li>Check the labelled haMSCs using a fluorescent microscope with a Cy5 filter set.</li>
	<li>Count the cells with trypan blue staining and obtain 2.5 x 106 viable cells in 100 &#181;L PBS for injection.</li>
</ol>
4. In Vivo Fluorescent Imaging to Track haMSCs
<ol>
	<li>Eight weeks after the surgery (Step 1), anesthetize the KOA rats by intramuscular injection of 25 mg/kg tiletamine and 25 mg/kg zolazepam.</li>
	<li>Shave the right knee thoroughly with a razor to expose the joint area. Disinfect the joint area with 70% ethanol.</li>
	<li>Using a 26 G syringe needle, inject 2.5 x 106 labeled cells suspended in 100 &#181;L PBS at the center of the triangle area formed by the medial side of the patellar ligament, the medial femoral condyle, and the medial tibial condyle (Figure 1B).</li>
	<li>Open the imaging software and initialize the in vivo bioluminescence imaging system.</li>
	<li>Position rats in the supine position in the central stage of the imaging system and close the door of the chamber.</li>
	<li>Check the &#34;fluorescent&#34; checkbox and select fluorescent filter sets of 640 nm for excitation, and 680 nm for emission (Figure 2A).</li>
	<li>Select field of view to D. Set pixel binning to medium (8), F/Stop to 2 and exposure time to auto. Maintain the optimal exposure time consistent to obtain comparable results across the entire study (Figure 2A).</li>
	<li>Remove the animal from the stage and monitor for recovery from anesthesia. 
	NOTE: Place animal on an heating pad covered with 2-3 layers of toweling.</li>
	<li>Choose the units of radiant efficiency for the measurement of fluorescence (Figure 2B). Select regions of interest (ROI) for analysis and quantify fluorescent signals from each image (Figure 2C).</li>
	<li>Repeat the procedure of in vivo imaging for each rat sequentially to study haMSCs longitudinal retention in the joint. 
	NOTE:&#160;We suggest imaging the animals&#39; fluorescent signals by in vivo imaging system once every two days for the first week after injection and once every week until the signal cannot be detected.</li>
</ol>

<ol>
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Meng Li, Ming Hao and Wen Wang are current employees and stock option holders of Cellular Biomedicine Group (Nasdaq: CBMG). The other authors declare no conflict of interest.

Safety standards and biodistribution studies of stem cell therapy are urgently needed before we can bring regenerative stem cell treatment for KOA from the bench to the bedside. However, the pathological environment of disease plays an important role in the persistence and biodistribution of transplanted haMSCs10. Recently, our group demonstrated that intra-articular injection of haMSCs persisted longer in a pathological KOA environment than did injections under normal conditions...

Knee osteoarthritis (KOA) is a degenerative disorder resulting from articular cartilage loss and progressive inflammation, which has become a major chronic disease in the elderly around the world1. However, current therapies using anti-inflammatory drugs, physical supplements, and surgical procedures may only provide temporary relief for symptomatic pain2.
Human adipose-derived mesenchymal stem cells (haMSCs) have become a promising regenerative remedy for knee osteoarthritis, owing to their multipotent differentiation potential for cartilage regeneration and immunomodulatory properties3,4. Compared with pharmacological routes to investigate mechanisms of action in vivo, tracking live haMSCs in small KOA animal models is currently instructive to establish the rationale for and feasibility of haMSC therapy prior to clinical application. For preclinical testing, medial meniscectomy (MM) destabilizes the mechanical load of the joint to induce KOA in rats, which provides a relatively feasible model with consistent reproducibility5. The onset of KOA induced by MM is earlier than anterior cruciate ligament transection alone or combined with partial medial meniscectomy6. Therefore, the long-term interactions between injected haMSCs with the pathological microenvironment of KOA are often assessed in rats induced by MM7,8.
Though the therapeutic efficacy of haMSCs has been extensively reported, relevant knowledge on the in vivo persistence of implanted haMSCs via intra-articular (IA) injection is scarce9,10. Hence, various cellular labeling methods have been developed, including immunohistology11, luciferase12, green fluorescent protein13 transfection, iron oxide labeling for magnetic resonance imaging (MRI)14, and numerous fluorescent cell dyes8,15,16. Compared with labor-intensive histology analyses, in vivo non-invasive imaging employs optical devices to detect the real-time distribution and dynamics of cells labeled with fluorescent signals10,17. For functional live cell imaging, cytocompatible fluorescent labeling is a sophisticated radioactive-free tracking technique to reveal cellular activities after stem cell transplantation18. Moreover, multicolor fluorescent lipophilic dyes possess advantages over amino-reactive hydrophilic dyes or fluorescent proteins, including their improved cell permeability and enhanced fluorescence quantum yields19.
Thus, the protocols included here utilize a red laser to excite cells labeled with lipophilic carbocyanines DiD (DilC18(5)), which is a far-red fluorescent Dil (dialkylcarbocyanines) analog20. The red-shifted excitation and emission spectra of DiD avoids autofluorescent interference and allows deep-tissue imaging over a long period of time in live animals8. This method of tracking cells in vivo labeled with DiD is valid for monitoring transplanted stem cells, such as haMSCs, in animal models, which is essential to understand and improve current stem cell regenerative therapy.

<table>
	<tbody>
		<tr>
			<td>Matrx VMR animal anesthesia system</td>
			<td>Midmark</td>
			<td>VIP3000</td>
			<td></td>
		</tr>
		<tr>
			<td>4-0 suture</td>
			<td>Shanghai Jinhuan</td>
			<td>KC439</td>
			<td></td>
		</tr>
		<tr>
			<td>Razor</td>
			<td>Pritech</td>
			<td>LD-9987</td>
			<td></td>
		</tr>
		<tr>
			<td>Gentamicin</td>
			<td>Zhejiang Jindakang Animal Health Product Co., Ltd.</td>
			<td>None</td>
			<td></td>
		</tr>
		<tr>
			<td>0.9% Sodium chloride solution</td>
			<td>Hunan Kelun Pharmaceutical Co., Ltd.</td>
			<td>H43020455</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin</td>
			<td>Shanghai Kangfu chemical pharmaceutical Co., Ltd.</td>
			<td>None</td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>Tianjin Pharmaceutical Research Institute Pharmaceutical Co., Ltd.</td>
			<td>None</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma-Aldrich</td>
			<td>16005</td>
			<td>Dilute to final concentration of 10% in PBS</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sigma-Aldrich</td>
			<td>E9884</td>
			<td>Dilute to final concentration of 20% in PBS</td>
		</tr>
		<tr>
			<td>0.1% Hematoxylin Solution, Mayer&#8217;s</td>
			<td>Sigma-Aldrich</td>
			<td>MHS16</td>
			<td></td>
		</tr>
		<tr>
			<td>0.5% Eosin Y solution, alcoholic</td>
			<td>Sigma-Aldrich</td>
			<td>HT110116</td>
			<td></td>
		</tr>
		<tr>
			<td>Safranin O</td>
			<td>Sigma-Aldrich</td>
			<td>S8884</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast Green</td>
			<td>Sigma-Aldrich</td>
			<td>F7258</td>
			<td></td>
		</tr>
		<tr>
			<td>Shandon Excelsior ESTM Tissue Processor</td>
			<td>Thermo Fisher</td>
			<td>A78400006</td>
			<td></td>
		</tr>
		<tr>
			<td>Shandon Histocentre&#8482; 3 Tissue Embedding Center</td>
			<td>Thermo Fisher</td>
			<td>B64100010</td>
			<td></td>
		</tr>
		<tr>
			<td>Fully Automated Rotary Microtome</td>
			<td>Leica</td>
			<td>RM2255</td>
			<td></td>
		</tr>
		<tr>
			<td>DiD</td>
			<td>Molecular Probes, Life 
			Technologies</td>
			<td>V-22887</td>
			<td></td>
		</tr>
		<tr>
			<td>D-MEM High Glucose</td>
			<td>Sigma-Aldrich</td>
			<td>D5648</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>GIBCO, Life Technologies</td>
			<td>14190-144</td>
			<td></td>
		</tr>
		<tr>
			<td>0.25% Trypsin-EDTA</td>
			<td>Invitrogen</td>
			<td>25200-114</td>
			<td></td>
		</tr>
		<tr>
			<td>10 cm Petri Dish</td>
			<td>Corning</td>
			<td>V118877</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Beckman</td>
			<td>Optima MAX-TL</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescent microscope</td>
			<td>Olympus</td>
			<td>BX53</td>
			<td></td>
		</tr>
		<tr>
			<td>0.4% Trypan Blue solution</td>
			<td>Sigma-Aldrich</td>
			<td>93595</td>
			<td></td>
		</tr>
		<tr>
			<td>Titetamme</td>
			<td>Virbac (Zoletil 50)</td>
			<td>1000000188</td>
			<td></td>
		</tr>
		<tr>
			<td>Zolazepam</td>
			<td>Virbac (Zoletil 50)</td>
			<td>1000000188</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile hyposermic syringe for single use 26G</td>
			<td>Shanghai Misawa Medical Industry</td>
			<td>None</td>
			<td></td>
		</tr>
		<tr>
			<td>IVIS Spectrum In Vivo Imaging System</td>
			<td>PerkinElmer</td>
			<td>124262</td>
			<td></td>
		</tr>
		<tr>
			<td>Living Imaging 4.0 software</td>
			<td>PerkinElmer</td>
			<td>None</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vivo tracking of human adipose-derived mesenchymal stem cells in a rat knee osteoarthritis model with fluorescent lipophilic membrane dye

In order to support the clinical application of human adipose-derived mesenchymal stem cell (haMSC) therapy for knee osteoarthritis (KOA), we examined the efficacy of cell persistence and biodistribution of haMSCs in animal models. We demonstrated a method to label the cell membrane of haMSCs with lipophilic fluorescent dye. Subsequently, intra-articular injection of the labeled cells in rats with surgically induced KOA was monitored dynamically by an in vivo imaging system. We employed the lipophilic carbocyanines DiD (DilC18 (5)), a far-red fluorescent Dil (dialkylcarbocyanines) analog, which utilized a red laser to avoid excitation of the natural green autofluorescence from surrounding tissues. Furthermore, the red-shifted emission spectra of DiD allowed deep-tissue imaging in live animals and the labeling procedure caused no cytotoxic effects or functional damage to haMSCs. This approach has been shown to be an efficient tracking method for haMSCs in a rat KOA model. The application of this method could also be used to determine the optimal administration route and dosage of MSCs from other sources in pre-clinical studies.

In order to induce KOA model, MM was performed in the right knee joint of SD rats (Figure 3). Eight weeks after surgery, rats were sacrificed and the serial sections of knee joints were evaluated with both H&#38;E and Safranin O/Fast Green staining (Figure 4). For H&#38;E staining, the surface of the articular cartilage exhibited rougher borders in the surgery knees than the normal joint without surgery. For Safranin-O/Fast green...

Watch this Scientific Journal Video about In Vivo Tracking of Human Adipose-derived Mesenchymal Stem Cells in a Rat Knee Osteoarthritis Model with Fluorescent Lipophilic Membrane Dye at JoVE.com

In Vivo Tracking of Human Adipose-derived Mesenchymal Stem Cells in a Rat Knee Osteoarthritis Model with Fluorescent Lipophilic Membrane Dye

This protocol describes an efficient way to monitor the cell persistence and biodistribution of human adipose-derived mesenchymal stem cells (haMSCs) by far-red fluorescence labeling in a rat knee osteoarthritis (KOA) model via intra-articular (IA) injection.

In Vivo Tracking of Human Adipose-derived Mesenchymal Stem Cells in a Rat Knee Osteoarthritis Model with Fluorescent Lipophilic Membrane Dye

In order to support the clinical application of human adipose-derived mesenchymal stem cell (haMSC) therapy for knee osteoarthritis (KOA), we examined the ...

in-vivo-tracking-human-adipose-derived-mesenchymal-stem-cells-rat

Research

JoVE Journal

Developmental Biology

8.9K Views.  Cellular Biomedicine Group, China. This protocol describes an efficient way to monitor the cell persistence and biodistribution of human adipose-derived mesenchymal stem cells (haMSCs) by far-red fluorescence labeling in a rat knee osteoarthritis (KOA) model via intra-articular (IA) injection.

Video: In Vivo Tracking of Human Adipose-derived Mesenchymal Stem Cells in a Rat Knee Osteoarthritis Model with Fluorescent Lipophilic Membrane Dye

Isolation and Enrichment of Human Adipose-derived Stromal Cells for Enhanced Osteogenesis

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) are considered the gold standard for stem cell-based tissue engineering applications. However, the process by which they must be harvested can be associated with significant donor site morbidity. In contrast, adipose-derived stromal cells (ASCs) are more readily abundant and more easily harvested, making them an appealing alternative to BM-MSCs. Like BM-MSCs, ASCs can differentiate into osteogenic lineage cells and can be used in tissue engineering applications, such as seeding onto scaffolds for use in craniofacial skeletal defects. ASCs are obtained from the stromal vascular fraction (SVF) of digested adipose tissue, which is a heterogeneous mixture of ASCs, vascular endothelial and mural cells, smooth muscle cells, pericytes, fibroblasts, and circulating cells. Flow cytometric analysis has shown that the surface marker profile for ASCs is similar to that for BM-MSCs. Despite several published reports establishing markers for the ASC phenotype, there is still a lack of consensus over profiles identifying osteoprogenitor cells in this heterogeneous population. This protocol describes how to isolate and use a subpopulation of ASCs with enhanced osteogenic capacity to repair critical-sized calvarial defects.

The transcriptional heterogeneity within human adipose-derived stromal cells can be defined on the single cell level using cell surface markers and osteogenic genes. We describe a protocol utilizing flow cytometry for the isolation of cell subpopulations with increased osteogenic potential, which may be used to enhance craniofacial skeletal reconstruction.

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) are considered the gold standard for stem cell-based tissue engineering applications. However, the ...

Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease.

In this study, we describe a straightforward method to perform Evans Blue Dye (EBD) analysis on zebrafish larvae. This technique is a powerful tool for the characterization of skeletal muscle integrity and delineation of zebrafish models of muscular dystrophy, and is a valuable method for the development of novel therapeutics.

The zebrafish model is an emerging system for the study of neuromuscular disorders.  In the study of neuromuscular diseases, the integrity of the muscle ...

Isolation and Differentiation of Adipose-Derived Stem Cells from Porcine Subcutaneous Adipose Tissues

Obesity is an unconstrained worldwide epidemic. Unraveling molecular controls in adipose tissue development holds promise to treat obesity or diabetes. Although numerous immortalized adipogenic cell lines have been established, adipose-derived stem cells from the stromal vascular fraction of subcutaneous white adipose tissues provide a reliable cellular system ex vivo much closer to adipose development in vivo. Pig adipose-derived stem cells (pADSC) are isolated from 7- to 9-day old piglets. The dorsal white fat depot of porcine subcutaneous adipose tissues is sliced, minced and collagenase digested. These pADSC exhibit strong potential to differentiate into adipocytes. Moreover, the pADSC also possess multipotency, assessed by selective stem cell markers, to differentiate into various mesenchymal cell types including adipocytes, osteocytes, and chondrocytes. These pADSC can be used for clarification of molecular switches in regulating classical adipocyte differentiation or in direction to other mesenchymal cell types of mesodermal origin. Furthermore, extended lineages into cells of ectodermal and endodermal origin have recently been achieved. Therefore, pADSC derived in this protocol provide an abundant and assessable source of adult mesenchymal stem cells with full multipotency for studying adipose development and application to tissue engineering of regenerative medicine.

This protocol describes the isolation of pig adipose-derived stem cells (pADSC) from subcutaneous adipose tissues with examination of multipotency. The multipotent pADSC are used to delineate processes of adipocyte differentiation and study transdifferentiation into multiple cell lineages of mesodermal mesenchyme or further lineages of ectoderm and endoderm for regenerative studies.

Obesity is an unconstrained worldwide epidemic. Unraveling molecular controls in adipose tissue development holds promise to treat obesity or diabetes. ...

Immunomagnetic Separation of Fat Depot-specific Sca1high Adipose-derived Stem Cells (ASCs)

The isolation of adipose-derived stem cells (ASCs) is an important method in the field of adipose tissue biology, adipogenesis, and extracellular matrix (ECM) remodeling. In vivo, ECM-rich environment consisting of fibrillar collagens provides a structural support to adipose tissues during the progression and regression of obesity. Physiological ECM remodeling mediated by matrix metalloproteinases (MMPs) plays a major role in regulating adipose tissue size and function1,2. The loss of physiological collagenolytic ECM remodeling may lead to excessive collagen accumulation (tissue fibrosis), macrophage infiltration, and ultimately, a loss of metabolic homeostasis including insulin resistance3,4. When a phenotypic change of the adipose tissue is observed in gene-targeted mouse models, isolating primary ASCs from fat depots for in vitro studies is an effective approach to define the role of the specific gene in regulating the function of ASCs. In the following, we define an immunomagnetic separation of Sca1high ASCs.

Immunomagnetic Separation of Fat Depot-specific Sca1high Adipose-derived Stem Cells ASCs

We present the techniques required to isolate the stromal vascular fraction (SVF) from mouse inguinal (subcutaneous) and perigonadal (visceral) adipose tissue depots to assess their gene expression and collagenolytic activity. This method includes the enrichment of Sca1high adipose-derived stem cells (ASCs) using immunomagnetic cell separation.

The isolation of adipose-derived stem cells (ASCs) is an important method in the field of adipose tissue biology, adipogenesis, and extracellular matrix ...

Isolation and Expansion of Mesenchymal Stem/Stromal Cells Derived from Human Placenta Tissue

Mesenchymal stem/stromal cells (MSC) are promising candidates for use in cell-based therapies. In most cases, therapeutic response appears to be cell-dose dependent. Human term placenta is rich in MSC and is a physically large tissue that is generally discarded following birth. Placenta is an ideal starting material for the large-scale manufacture of multiple cell doses of allogeneic MSC. The placenta is a fetomaternal organ from which either fetal or maternal tissue can be isolated. This article describes the placental anatomy and procedure to dissect apart the decidua (maternal), chorionic villi (fetal), and chorionic plate (fetal) tissue. The protocol then outlines how to isolate MSC from each dissected tissue region, and provides representative analysis of expanded MSC derived from the respective tissue types. These methods are intended for pre-clinical MSC isolation, but have also been adapted for clinical manufacture of placental MSC for human therapeutic use.

Herein we describe methods for the dissection of fetal and maternal tissues from human term placenta, followed by isolation and expansion of mesenchymal stem/stromal cells (MSC) from these tissues.

Mesenchymal stem/stromal cells (MSC) are promising candidates for use in cell-based therapies. In most cases, therapeutic response appears to be cell-dose ...

Chondrogenic Differentiation Induction of Adipose-derived Stem Cells by Centrifugal Gravity

Impaired cartilage cannot heal naturally. Currently, the most advanced therapy for defects in cartilage is the transplantation of chondrocytes differentiated from stem cells using cytokines. Unfortunately, cytokine-induced chondrogenic differentiation is costly, time-consuming, and associated with a high risk of contamination during in vitro differentiation. However, biomechanical stimuli also serve as crucial regulatory factors for chondrogenesis. For example, mechanical stress can induce chondrogenic differentiation of stem cells, suggesting a potential therapeutic approach for the repair of impaired cartilage. In this study, we demonstrated that centrifugal gravity (CG, 2,400 &#215; g), a mechanical stress easily applied by centrifugation, induced the upregulation of sex determining region Y (SRY)-box 9 (SOX9) in adipose-derived stem cells (ASCs), causing them to express chondrogenic phenotypes. The centrifuged ASCs expressed higher levels of chondrogenic differentiation markers, such as aggrecan (ACAN), collagen type 2 alpha 1 (COL2A1), and collagen type 1 (COL1), but lower levels of collagen type 10 (COL10), a marker of hypertrophic chondrocytes. In addition, chondrogenic aggregate formation, a prerequisite for chondrogenesis, was observed in centrifuged ASCs.

Mechanical stress can induce the chondrogenic differentiation of stem cells, providing a potential therapeutic approach for the repair of impaired cartilage. We present a protocol to induce the chondrogenic differentiation of adipose-derived stem cells (ASCs) using centrifugal gravity (CG). CG-induced upregulation of SOX9 results in the development of chondrogenic phenotypes.

Impaired cartilage cannot heal naturally. Currently, the most advanced therapy for defects in cartilage is the transplantation of chondrocytes ...

Rapid Isolation of BMPR-IB+ Adipose-Derived Stromal Cells for Use in a Calvarial Defect Healing Model

Invasive cancers, major injuries, and infection can cause bone defects that are too large to be reconstructed with preexisting bone from the patient's own body. The ability to grow bone de novo using a patient's own cells would allow bony defects to be filled with adequate tissue without the morbidity of harvesting native bone. There is interest in the use of adipose-derived stromal cells (ASCs) as a source for tissue engineering because these are obtained from an abundant source: the patient's own adipose tissue. However, ASCs are a heterogeneous population and some subpopulations may be more effective in this application than others. Isolation of the most osteogenic population of ASCs could improve the efficiency and effectiveness of a bone engineering process. In this protocol, ASCs are obtained from subcutaneous fat tissue from a human donor. The subpopulation of ASCs expressing the marker BMPR-IB is isolated using FACS. These cells are then applied to an in vivo calvarial defect healing assay and are found to have improved osteogenic regenerative potential compared with unsorted cells.

Adipose-derived stromal cells may be useful for engineering new tissue from a patient's own cells. We present a protocol for the isolation of a subpopulation of human adipose-derived stromal cells (ASCs) with increased osteogenic potential, followed by application of the cells in an in vivo calvarial healing assay.

Invasive cancers, major injuries, and infection can cause bone defects that are too large to be reconstructed with preexisting bone from the patient's own ...

Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem cells (hPSCs). Until recently, efforts to differentiate hPSCs into HSCs have predominantly generated hematopoietic progenitors that lack HSC potential, and instead resemble yolk sac hematopoiesis.&#160;These resulting hematopoietic progenitors may have limited utility for in vitro disease modeling of various adult hematopoietic disorders, particularly those of the lymphoid lineages. However, we have recently described methods to generate erythro-myelo-lymphoid multilineage definitive hematopoietic progenitors from hPSCs using a stage-specific directed differentiation protocol, which we outline here. Through enzymatic dissociation of hPSCs on basement membrane matrix-coated plasticware, embryoid bodies (EBs) are formed. EBs are differentiated to mesoderm by recombinant BMP4, which is subsequently specified to the definitive hematopoietic program by the GSK3&#946; inhibitor, CHIR99021. Alternatively, primitive hematopoiesis is specified by the PORCN inhibitor, IWP2. Hematopoiesis is further driven through the addition of recombinant VEGF and supportive hematopoietic cytokines. The resulting hematopoietic progenitors generated using this method have the potential to be used for disease and developmental modeling, in vitro.

Here, we present human pluripotent stem cell (hPSC) culture protocols, used to differentiate hPSCs into CD34+ hematopoietic progenitors. This method uses stage-specific manipulation of canonical WNT signaling to specify cells exclusively to either the definitive or primitive hematopoietic program.

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem ...

In Vitro Differentiation of Human Mesenchymal Stem Cells into Functional Cardiomyocyte-like Cells

Myocardial infarction and the subsequent ischemic cascade result in the extensive loss of cardiomyocytes, leading to congestive heart failure, the leading cause of mortality worldwide. Mesenchymal stem cells (MSCs) are a promising option for cell-based therapies to replace current, invasive techniques. MSCs can differentiate into mesenchymal lineages, including cardiac cell types, but complete differentiation into functional cells has not yet been achieved. Previous methods of differentiation were based on pharmacological agents or growth factors. However, more physiologically relevant strategies can also enable MSCs to undergo cardiomyogenic transformation. Here, we present a differentiation method using MSC aggregates on cardiomyocyte feeder layers to produce cardiomyocyte-like contracting cells.
Human umbilical cord perivascular cells (HUCPVCs) have been shown to have a greater differentiation potential than commonly investigated MSC types, such as bone marrow MSCs (BMSCs). As an ontogenetically younger source, we investigated the cardiomyogenic potential of first-trimester (FTM) HUCPVCs compared to older sources. FTM HUCPVCs are a novel, rich source of MSCs that retain their in utero immunoprivileged properties when cultured in vitro. Using this differentiation protocol, FTM and term HUCPVCs achieved significantly increased cardiomyogenic differentiation compared to BMSCs, as indicated by the increased expression of cardiomyocyte markers (i.e., myocyte enhancer factor 2C, cardiac troponin T, heavy chain cardiac myosin, signal regulatory protein &#945;, and connexin 43). They also maintained significantly lower immunogenicity, as demonstrated by their lower HLA-A expression and higher HLA-G expression. Applying aggregate-based differentiation, FTM HUCPVCs showed increased aggregate formation potential and generated contracting cells clusters within 1 week of co-culture on cardiac feeder layers, becoming the first MSC type to do so. 
Our results demonstrate that this differentiation strategy can effectively harness the cardiomyogenic potential of young MSCs, such as FTM HUCPVCs, and suggests that in vitro pre-differentiation could be a potential strategy to increase their regenerative efficacy in vivo.

In Vitro Differentiation of Human Mesenchymal Stem Cells into Functional Cardiomyocyte-like Cells

Here, we present a method to efficiently harness the cardiac differentiation potential of young sources of human mesenchymal stem cells in order to generate functional, contracting, cardiomyocyte-like cells in vitro.

Myocardial infarction and the subsequent ischemic cascade result in the extensive loss of cardiomyocytes, leading to congestive heart failure, the leading ...

Culturing of Retinal Pigment Epithelial Cells on an Ex Vivo Model of Aged Human Bruch's Membrane

Aside from vitamins and antioxidants recommended by the Age-Related Eye Disease Study, there is no effective therapy for &#34;dry,&#34;&#160;or atrophic age-related macular degeneration (AMD) which represents 90% of the cases. Therapies are needed to slow or retard the development of geographic atrophy (GA), and understanding Bruch&#39;s membrane pathology is part of this process. Alterations in human Bruch&#39;s membrane precede the progression of AMD by contributing to the damage of retinal pigment epithelial (RPE) cells. Given the lack of sufficient animal models to study AMD, ex vivo models of aged human Bruch&#39;s membrane serve as a useful tool to study the behavior of RPE cells from immortalized and primary cell lines as well as RPE lines derived from induced pluripotent stem cells (iPSCs). Here, we present a detailed method that allows one to determine the effects of RPE cell behavior seeded on harvested human Bruch&#39;s membrane explants from human donors, including attachment, apoptosis and proliferation, ability to phagocytize photoreceptor outer segments, establishment of polarity, and gene expression. This assay provides an ex vivo model of aged Bruch&#39;s membrane to assess the functional characteristics of RPE cells when seeded on aged/compromised extracellular matrix.

Culturing of Retinal Pigment Epithelial Cells on an Ex Vivo Model of Aged Human Bruch's Membrane

The goal of this protocol is to demonstrate the culturing of retinal pigment epithelial (RPE) cells on aged and/or diseased human Bruch&#39;s membrane. This method is suitable to study RPE cell behavior on a compromised extracellular matrix.

Aside from vitamins and antioxidants recommended by the Age-Related Eye Disease Study, there is no effective therapy for &#34;dry,&#34;&#160;or atrophic ...