Welcome to Applied Biological Materials growth factors and cytokines video series! In this
video, we will introduce what are growth factors and cytokines, how they function, and how
they can be applied in scientific research in clinical settings.
Growth factors and cytokines are vital signaling molecules that control cell activities in
an autocrine, paracrine or endocrine manner. They are key to a cell’s biological function
by binding to specific receptors and activating associated downstream signaling pathways which
in turn, regulate gene transcription in the nucleus and ultimately stimulate a biological
response. Serving such a crucial role in cells, growth factors and cytokines are absolutely
indispensible to human physiology research. At Applied Biological Materials, or abm, we
offer a wide range of recombinant human growth factors and cytokines at competitive prices
for all your growth factor needs. Growth factors and cytokines affect a wide
variety of physiological processes such as cell proliferation, differentiation, apoptosis,
morphogenesis, metabolism, wound healing, and tissue homeostasis
in adult organisms. Abnormal expression or regulation of growth factors and cytokines
can instead cause various diseases such as cancer, liver fibrosis, and bronchopulmonary
dysplasia. In the past growth factors and cytokines were
thought to respectively serve as cell growth components and immunological response factors.
More recently, as different lines of research have converged, it has been found that cytokines
and growth factors can have similar functions and therefore, these terms are now
used interchangeably. There are several different signaling mechanisms
a cell uses to best suit its purpose. Paracrine signaling occurs between neighboring
cells where the signals elicit quick responses and last only a short while due to the degradation
of the paracrine ligands. In autocrine signaling, a cell signals itself through a component
that it synthesizes, leading to a biological response within the same cell. Lastly in endocrine
signaling, growth factor and cytokine components are secreted into the blood and are then carried by
blood and tissue fluids onto target cells whereby subsequent responses are triggered.
Growth factors can also be divided into various families or superfamilies based on structural
and functional characteristics. An example of a major growth factor family includes:
The Transforming Growth Factor Beta (TGF-beta) Superfamily. In this example, all family members
have dimeric structures and their heterodimeric receptor complexes consisting of type I and
type II receptor subunits with serine or threonine kinase domains. Within the family, complex
interaction remains the same. Following ligand binding, the type II receptor phosphorylates
and activates the type I receptor which then activates a Smad-dependent signaling pathway
that regulates gene transcription. For research purposes, growth factors are
used in a wide variety of cell models to study their functions and their intricate
signaling pathways. Based on their roles, many growth factors and cytokines have
also been utilized for preclinical and clinical applications. Recombinant Human Platelet-Derived
Growth Factor (PDGF), for example, has been used to stimulate angiogenesis, migration
and mitosis of mesenchymal cells in preclinical studies.
Although clinical applications of cytokines are considered standard treatment for certain
diseases, there are also side effects accompanied with them. For example, the administration
of G-CSF has been reported to cause osteoporosis, bone marrow necrosis and acute coronary syndrome
High quality growth factors must pass rigorous quality control testing for purity,
quantification, and activity. Purity tests such as SDS-PAGE can determine whether or
not the product is contaminated with non-specific proteins and/or endotoxins that can trigger
undesirable effects such as cell differentiation. Quantification is used to achieve product
size and results. Commonly used protein quantification methods are: Bradford colorimetric dye,
UV-Visible Spectroscopy, and Densitometric comparison. Growth factor activity is tested
through specific bioassays that determine the relative strength of the growth factor
to a standard. At abm our growth factor and cytokine products
are extensively tested through these quality control standards
before they are delivered to our customers. If you have any questions and comments please leave them below
and we will answer them as soon as possible. If you enjoyed this video, check out our other video series and subscribe to get the latest updates! Thank you for watching!