This protocol describes a methodology for isolating and identifying adipose tissue-derived mesenchymal stem cells (MSCs) from Sprague Dawley rats.
Adult mesenchymal cells have revolutionized molecular and cell biology in recent decades. They can differentiate into different specialized cell types, in addition to their great capacity for self-renewal, migration, and proliferation. Adipose tissue is one of the least invasive and most accessible sources of mesenchymal cells. It has also been reported to have higher yields compared to other sources, as well as superior immunomodulatory properties. Recently, different procedures for obtaining adult mesenchymal cells from different tissue sources and animal species have been published. After evaluating the criteria of some authors, we standardized a methodology that is applicable to different purposes and easily reproducible. A pool of stromal vascular fraction (SVF) from perirenal and epididymal adipose tissue allowed us to develop primary cultures with optimal morphology and functionality. The cells were observed adhered to the plastic surface for 24 h, and exhibited a fibroblast-like morphology, with prolongations and a tendency to form colonies. Flow cytometry (FC) and immunofluorescence (IF) techniques were used to assess the expression of the membrane markers CD105, CD9, CD63, CD31, and CD34. The ability of adipose-derived stem cells (ASCs) to differentiate into the adipogenic lineage was also assessed using a cocktail of factors (4 µM insulin, 0.5 mM 3-methyl-iso-butyl-xanthine, and 1 µM dexamethasone). After 48 h, a gradual loss of fibroblastoid morphology was observed, and at 12 days, the presence of lipid droplets positive to oil red staining was confirmed. In summary, a procedure is proposed to obtain optimal and functional ASC cultures for application in regenerative medicine.
Mesenchymal stem cells (MSCs) have strongly impacted regenerative medicine due to their high capacity for self-renewal, proliferation, migration, and differentiation into different cell lineages1,2. Currently, a great deal of research is focusing on their potential for the treatment and diagnosis of various diseases.
There are different sources of mesenchymal cells: bone marrow, skeletal muscle, amniotic fluid, hair follicles, placenta, and adipose tissue, among others. They are obtained from different species, including humans, mice, rats, dogs, and horses3. Bone marrow-derived MSCs (BMSCs) have been used for many years as a major source of stem cells in regenerative medicine and as an alternative to the use of embryonic stem cells4. However, adipose-derived MSCs, or adipose-derived stem cells (ASCs), are an important alternative with great advantages due to their ease of collection and isolation, as well as the yield of cells obtained per gram of adipose tissue5,6. It has been reported that the harvest rate of ASCs is generally higher than that of BMSCs7. It was initially proposed that the reparative/regenerative capacity of ASCs was due to their ability to differentiate into other cell lineages8. However, research in recent years has reinforced the primary role of paracrine factors released by ASCs in their reparative potential9,10.
Adipose tissue (AT), in addition to being an energy reserve, interacts with the endocrine, nervous, and cardiovascular systems. It is also involved in postnatal growth and development, the maintenance of tissue homeostasis, tissue repair, and regeneration. The AT is composed of adipocytes, vascular smooth muscle cells, endothelial cells, fibroblasts, monocytes, macrophages, lymphocytes, preadipocytes, and ASCs. The latter possess an important role in regenerative medicine due to their low immunogenicity11,12. ASCs can be obtained by enzymatic digestion and mechanical processing or by adipose tissue explants. Primary cultures of ASCs are easy to maintain, grow, and expand. Phenotypic characterization of ASCs is essential to verify the identity of the cells by assessing the expression of specific membrane markers using methods such as immunofluorescence and flow cytometry13. The International Federation for Adipose Therapeutics and Science (IFATS) and the International Society for Cellular Therapy (ISCT) have defined that ASCs express CD73, CD90, and CD105, while lacking the expression of CD11b, CD14, CD19, CD45, and HLA-DR14. These markers, both positive and negative, are therefore considered reliable for the characterization of ASCs.
This project was focused on describing a procedure for the isolation and identification of adult mesenchymal cells extracted from rats’ AT, as this source of cells does not present ethical challenges, unlike embryonic stem cells. This solidifies the procedure as a viable option because of the ease of access and minimally invasive method compared to bone marrow-derived stem cells.
Mesenchymal cells from this tissue source have an important role in regenerative medicine because of their immunomodulatory capabilities and low immune rejection. Therefore, the present study is a fundamental part of future research into their secretome and their application as regenerative therapy in different diseases, including metabolic diseases such as diabetes.
In the last four decades since the discovery of MSCs, several groups of researchers have described procedures for obtaining MSCs from different tissues and species. One of the advantages of using rats as an animal model is their easy maintenance and rapid development, as well as the ease of obtaining MSCs from adipose tissue. Different tissue sources have been described for obtaining ASCs, such as visceral, perirenal, epididymal, and subcutaneous fat12,13,</…
The authors have nothing to disclose.
The authors are grateful to the Mexican Institute of Social Security (IMSS) and Children's Hospital of Mexico, Federico Gomez (HIMFG) and the Bioterio staff of the IMSS Research Coordination, for the support given to carry out this project. We thank the National Council of Science and Technology for the AOC (815290) scholarship and Antonio Duarte Reyes for the technical support in the audiovisual material.
Amphotericin B | HyClone | SV30078.01 | |
Analytical balance | Sartorius | AX224 | |
Antibody anti- CD9 (C-4) | Santa Cruz | Sc-13118 | |
Antibody anti-CD34 (C-18) | Santa Cruz | Sc-7045 | |
Antibody anti-C63 | Santa Cruz | Sc-5275 | |
Antibody anti-Endoglin/CD105 (P3D1) Alexa Fluor 594 | Santa Cruz | Sc-18838A594 | |
Antibody anti-CD31/PECM-1 Alexa Fluor 680 | Santa Cruz | Sc-18916AF680 | |
Antibody Goat anti-rabitt IgG (H+L) Cy3 | Novus | NB 120-6939 | |
Antibody Donkey anti-goat IgG (H+L) DyLight 550 | Invitrogen | SA5-10087 | |
Antibody anti-mouse IgG FITC conjugated goat F (ab´) | RD Systems. | No. F103B | |
Bottle Top Filter Sterile | CORNING | 10718003 | |
Cell and Tissue Culture Flasks | BIOFIL | 170718-312B | |
Cell Counter Bright-Line Hemacytometer with cell counting chamber slides | SIGMA Aldrich | Z359629 | |
Cell wells: 6 well with Lid | CORNING | 25810 | |
Centrifuge conical tubes | HeTTICH | ROTANA460R | |
Centrifuge eppendorf tubes | Fischer Scientific | M0018242_44797 | |
Collagen IV | Worthington | LS004186 | |
Cryovial | SPL Life Science | 43112 | |
Culture tubes | Greiner Bio-One | 191180 | |
CytExpert 2.0 | Beckman Coulter | Free version | |
CytoFlex LX cytometer | Beckman Coulter | FLOW-2463VID03.17 | |
DMEM | GIBCO | 31600-034 | |
DMSO | SIGMA Aldrich | 67-68-5 | |
DraQ7 Dye | Thermo Sc. | D15106 | |
EDTA | SIGMA Aldrich | 60-00-4 | |
Eosin yellowish | Hycel | 300 | |
Ethanol 96% | Baker | 64-17-5 | |
Falcon tubes 15 mL | Greiner Bio-One | 188271 | |
Falcon tubes 50 mL | Greiner Bio-One | 227261 | |
Fetal Bovine Serum | CORNING | 35-010-CV | |
Gelatin | SIGMA Aldrich | 128111163 | |
Gentamicin | GIBCO | 15750045 | |
Glycerin-High Purity | Herschi Trading | 56-81-5 | |
Hematoxylin | AMRESCO | 0701-25G | |
Heracell 240i CO2 Incubator | Thermo Sc. | 50116047 | |
Ketamin Pet (Ketamine clorhidrate) | Aranda | SV057430 | |
L-Glutamine | GIBCO/ Thermo Sc. | 25030-081 | |
LSM software Zen 2009 V5.5 | Free version | ||
Biological Safety Cabinet Class II | NuAire | 12082100801 | |
Epifluorescent microscope | Zeiss Axiovert 100M | 21.0028.001 | |
Inverted microscope | Olympus CK40 | CK40-G100 | |
Non-essential amino acids 100X | GIBCO | 11140050 | |
Micro tubes 2 mL | Sarstedt | 72695400 | |
Micro tubes 1,5 mL | Sarstedt | 72706400 | |
Micropipettes 0.2-2 μL | Finnpipette | E97743 | |
Micropipettes 2-20 μL | Finnpipette | F54167 | |
Micropipettes 20-200 μL | Finnpipette | G32419 | |
Micropipettes 100-1000 μL | Finnpipette | FJ39895 | |
Nitrogen tank liquid | Taylor-Wharton | 681-021-06 | |
Paraformaldehyde | SIGMA Aldrich | SLBC3029V | |
Penicillin / Streptomycin | GIBCO/ Thermo Sc. | 15140122 | |
Petri dish Cell culture | CORNING Inc | 480167 | |
Pipet Tips | Axygen Scientific | 301-03-201 | |
Pisabental (pentobarbital sodium) | PISA Agropecuaria | Q-7833-215 | |
Potassium chloride | J.T.Baker | 7447-40-7 | |
Potassium Phosphate Dibasic | J.T Baker | 2139900 | |
S1 Pipette Fillers | Thermo Sc | 9531 | |
Serological pipette 5 mL | PYREX | L010005 | |
Serological pipette 10 mL | PYREX | L010010 | |
Sodium bicarbonate | J.T Baker | 144-55-8 | |
Sodium chloride | J.T.Baker | 15368426 | |
Sodium Phosphate Dibasic Anhydrous | J.T Baker | 7558-79-4 | |
Sodium pyruvate | GIBCO BRL | 11840-048 | |
Syringe Filter Sterile | CORNING | 431222 | |
Spectrophotometer | PerkinElmer Lambda 25 | L6020060 | |
Titer plate shaker | LAB-LINE | 1250 | |
Transfer pipets | Samco/Thermo Sc | 728NL | |
Trypan Blue stain | GIBCO | 1198566 | |
Trypsin From Porcine Pancreas | SIGMA Aldrich | 102H0234 | |
Tween 20 | SIGMA Aldrich | 9005-64-5 | |
Universal Blocking Reagent 10x | BioGenex | HK085-GP | |
Xilapet 2% (xylazine hydrochloride) | Pet's Pharma | Q-7972-025 |