Apart from integrins, cadherins, selectins, and cadherins, other cell surface
receptors have also been described to be crucial for stem cell niche interactions
which include EGF, frizzled, Notch, TGF-ß, c-kits, gap junctions, VCAM 1, and
CD44 (Chen et al. 2013)
12.3.3 Basement Membrane
Basement membrane is thin and densely organized sheet like structure consisting of
self-organized ECM surrounding most of the animal tissues. Recent studies have
demonstrated that basement membrane is a component of stem cell niches in many
tissues including testis of Drosophila, mammary gland, epidermis, ovary and gut,
and prostate (Hall et al. 2006; Kendrick et al. 2008; Lawson et al. 2007; O’Reilly
et al. 2008; Ohlstein and Spradling 2006; Shackleton et al. 2006; Tanentzapf et al.
2007; Tumbar et al. 2004).
Laminins are the key proteins forming a component of the basement membrane
proteins and consist of α6-containing integrin dimers which serve as receptors for the
laminin protein. Studies have proven that stem cell properties are altered on disruption of the stem cell niche. For example, Lechler and Fuchs in 2005 demonstrated
that on deleting β1 integrin or α-catenin from basal keratinocytes the orientation of
the cell division plane changes resulting in altered epidermal homeostasis. Research
has shown that in some mammalian tissues which include brain, intestine, mammary
glands, and prostate gland, stem cells are in close contact to the basement membrane.
In mammalian intestine these stem cells are localized at the base of the crypts and are
in direct contact with the basement membrane (Barker et al. 2008; Haegebarth and
Clevers 2009; Walker and Stappenbeck 2008). Similarly, stem cells in mammary
and prostate glands reside in the basal compartment of the epithelium and interact
with the underlying basement membrane directly (Lawson et al. 2007). Basement
membrane-like structures in the neurogenic zones of the brain have been shown by
Krever et al (2007).
12.4 Stem Cell a Target for Environmental Pollution
Extensive studies on the effect of environmental pollution on stem cells properties
and accumulation of vast information has led to the development of new branch of
toxicology, i.e. stem cell toxicology.
12.4.1 Stem Cell Toxicology
It is the branch of toxicology aiming to provide solution to evaluate the cellular,
developmental, reproductive, and functional toxicity of the pollutant of interest using
stem cells as a model system mimicking the human physiology in vitro (Faiola et al.
2015). Several pollutants such as industrial waste, pesticides, drugs, cosmetics, food
12 Environmental Interaction and Impact on the Life Span of Stem Cells
255
receptors have also been described to be crucial for stem cell niche interactions
which include EGF, frizzled, Notch, TGF-ß, c-kits, gap junctions, VCAM 1, and
CD44 (Chen et al. 2013)
12.3.3 Basement Membrane
Basement membrane is thin and densely organized sheet like structure consisting of
self-organized ECM surrounding most of the animal tissues. Recent studies have
demonstrated that basement membrane is a component of stem cell niches in many
tissues including testis of Drosophila, mammary gland, epidermis, ovary and gut,
and prostate (Hall et al. 2006; Kendrick et al. 2008; Lawson et al. 2007; O’Reilly
et al. 2008; Ohlstein and Spradling 2006; Shackleton et al. 2006; Tanentzapf et al.
2007; Tumbar et al. 2004).
Laminins are the key proteins forming a component of the basement membrane
proteins and consist of α6-containing integrin dimers which serve as receptors for the
laminin protein. Studies have proven that stem cell properties are altered on disruption of the stem cell niche. For example, Lechler and Fuchs in 2005 demonstrated
that on deleting β1 integrin or α-catenin from basal keratinocytes the orientation of
the cell division plane changes resulting in altered epidermal homeostasis. Research
has shown that in some mammalian tissues which include brain, intestine, mammary
glands, and prostate gland, stem cells are in close contact to the basement membrane.
In mammalian intestine these stem cells are localized at the base of the crypts and are
in direct contact with the basement membrane (Barker et al. 2008; Haegebarth and
Clevers 2009; Walker and Stappenbeck 2008). Similarly, stem cells in mammary
and prostate glands reside in the basal compartment of the epithelium and interact
with the underlying basement membrane directly (Lawson et al. 2007). Basement
membrane-like structures in the neurogenic zones of the brain have been shown by
Krever et al (2007).
12.4 Stem Cell a Target for Environmental Pollution
Extensive studies on the effect of environmental pollution on stem cells properties
and accumulation of vast information has led to the development of new branch of
toxicology, i.e. stem cell toxicology.
12.4.1 Stem Cell Toxicology
It is the branch of toxicology aiming to provide solution to evaluate the cellular,
developmental, reproductive, and functional toxicity of the pollutant of interest using
stem cells as a model system mimicking the human physiology in vitro (Faiola et al.
2015). Several pollutants such as industrial waste, pesticides, drugs, cosmetics, food
12 Environmental Interaction and Impact on the Life Span of Stem Cells
255