Initially, biomedical research employed animals as study models to understand basic human physiology. The use of these models was ultimately limited to preclinical studies with the advent of in vitro culture. However, including in vivo investigations into research highlighted the necessity of appropriate in vitro models in order to improve reproducibility.
Mouse Primary Cells, therefore, offered an appropriate platform for in vitro research due to the extensive application of mice for in vivo studies. Due to their similarity with humans, they considerably augmented the knowledge base of tissue function, disease pathology, and drug response. This blog explores the utilization of mouse primary cell culture and its significance.
Why Mouse Primary Cells?
Mouse Primary Cells are cells isolated directly from mice tissues or organs. Despite their short lifespan, they have been used tremendously. Here are a few reasons why:
- Human cell extraction from tissues is not always feasible due to donor shortage or the need for a specific donor profile. Therefore, mouse primary cell culture is particularly beneficial in the absence of suitable human cells.
- Humans and mice share more than 95% genetic similarity, increasing their relevance as substitutes for human cells. Therefore, studies on mice often translate effectively into humans.
- Procuring human cells for research is preferred through a cell culture research company owing to regulatory, ethical, and cell quality issues. On the other hand, many research institutions incorporate animal housing facilities that facilitate cell isolation from mice.
- Mouse models are compatible with genetic manipulation. Therefore, primary cell culture from mice offer diverse options specific to disease modeling while also displaying relatively more homogeneity than human cells.
- Due to in-house breeding, the donor’s profile can be customized regarding age, gender, weight, etc. This gives some control over the study design.
- The easy availability of mouse cells also reduces its cost, making it a more practical alternative.
Mouse Strains for Primary Cell Isolation
The choice of strain impacts the biological behavior of the cultured primary cells. Here are a few common strains.
- Inbred Strains: They are genetically identical due to breeding over several generations. A few examples are-
- C57BL/6: A widely used black mouse strain has a well-characterized genome, with applications in immunology, neuroscience, and stem cell research.
- BALB/c: Often used in immunological studies due to its distinct immune profile.
- DBA/2 and SJL/J: Used in disease-specific research such as neurodegeneration and atherosclerosis.
- Outbred Strains: These are genetically diverse due to the mating between unrelated mice. For example, CD1 is an albino strain, which is applicable for pharmacological studies.
- Hybrid Strain: Such mice are developed by crossing two different inbred strains, showcasing different genetic profiles. For example, B6D2 was formed from DBA/2 and C57BL6.
- Spontaneous Mutant: These mice are bred to preserve the characteristics of spontaneous genetic mutations suitable for research into specific diseases.
For example,
- NOD (nonobese diabetic) Mice: It is beneficial for studying type 1 diabetes and other autoimmune disorders.
- Athymic nude mice: Lack a thymus due to a mutation, making them ideal for immunological studies and infectious disease research.
Selecting the appropriate strain helps tailor experiments depending on the physiological or pathological focus. Additionally, genetically engineering of these strains by deletion (knock-out) or insertion (knock-in) of particular genes can create more specific disease models.
Disadvantages of Mouse Primary Cells
Biomedical research aims to understand human biology and develop therapeutics. It employs mouse cells for the purpose, but they are not ideal due to several factors:
- The Encyclopedia of DNA Elements (ENCODE) analysis showed that despite genetic similarity, the regulatory pathways in humans and mice differ considerably.
- The size difference between the two species impacts several cellular pathways.
- Mice cannot mimic the complexities of human disease development, such as environmental factors, genetics, and lifestyle. Therefore, translation of studies on Mouse Primary Cell Culture into humans often falls short.
Mouse Cell Lines
Although mouse primary cells are valuable tools for research, their limited proliferation prompts multiple isolations from the organism. Therefore, in vitro culture often employs immortal mouse cell lines. They are developed in the laboratory or extracted from cancer models of mice. For instance, spontaneous immortalization in the lab created the 3T3 mouse cell line belonging to embryonic fibroblasts. These cell lines can serve as feeder layers and also have applications in DNA transfection studies. Many variants of 3T3 mouse cell lines are available in vitro for the study of specific diseases or cellular processes.
Mouse Primary Cell Culture
Isolating primary cells from mice typically involves harvesting tissue, mincing it, and incubation in an enzymatic solution or a culture medium. Centrifugation and strainer separates the cells from tissue pieces and debris. The last step involves cell characterization by surface markers via flow cytometry.
Primary cell culture usually requires optimized conditions for survival and proliferation, which vary by cell type. These conditions include a growth medium (DMEM, RPMI, IMDM) supplemented with serum, antibiotics, and growth factors if needed. Instead of a standard culture dish, cells might adhere to a coating on it like collagen, gelatin, fibronectin, etc. Standardization of the medium according to cells ensures optimal growth. Additionally, maintaining sterile conditions to avoid contamination, and routine monitoring aids in determining the density and health of cells.
Applications of Mouse Cells
The Mendelian inheritance in mice coat colors offered mice as a model for genetic studies. Since then, the applications of mice have expanded, leading to the development of more animal models and the culture of their cells.
- Developmental Biology: The development of embryonic mouse cell lines propelled the field of developmental biology. Mouse embryonic cells also became a foundation for understanding the development process. These studies have provided a definite timeline of different morphogenesis milestones.
- Immunological Research: Owing to the immunodeficient mouse strains, studies on mice cells have led to several achievements in immunological research such as defining immune response, understanding leukocyte development, detailing tumor microenvironment, etc.
- Neurological Disorders: Mice brain cells have driven the research on nervous system development and neurological disorders. It has encouraged the formulation of therapeutics and facilitated their screening.
- Cancer Research: Mouse cell lines have been critical for oncology. They have given novel insights into tumor growth, metastasis, and treatment response.
Conclusion
Mouse primary cells have opened various avenues of research and contributed to significant scientific developments over the years. Despite their disadvantages, they remain the most relevant in vitro platforms in the absence of their human counterpart. Their high availability and affordability have encouraged their application. Even though the inferences from these cells are not exactly precise as for human cells, the conclusions from them are still fairly accurate. However, culture optimization and careful strain selection are necessary for their culture. They enable researchers to harness their full potential in biomedical research, providing insights applicable to human health and disease. Kosheeka provides mouse primary cells from different strains and also offers donor profile customization to suit your research needs and enhance study results.
FAQ’s
Q- Why is the mouse primary cell culture widely used in biomedical research?
Mouse cells are favored because they are more readily available, cost-effective, and ethically easier to obtain than human cells, which require specific donor profiles and are limited by regulatory restrictions. Moreover, mice share more than 95% genetic similarity with humans, making mouse cells highly relevant substitutes.
Q- How does mouse strain impact primary cell culture experiments?
Each strain has different characteristics that influence the experimental outcomes of their cell cultures. For instance, C57BL/6 provide genetic consistency while CD1 are genetically diverse, leading to different applications.
Q- What are the main limitations of using mouse primary cells for studying human diseases?
Despite their advantages, mouse cells do not perfectly replicate human biology. The differences in the two species can result in incomplete translation of findings in human clinical studies.
Q- Why do researchers use immortalized mouse cell lines?
Immortal cell lines can proliferate indefinitely, providing a consistent and renewable resource for long-term studies.
