Page 36 - GPD-3-4

Gene & Protein in Disease Buccal mucosa and aging

microbial, and physical threats, serving as a barrier In addition, molecular modifications in the immune
between external aggressors and underlying tissues. Due system, including oral immunity and related immune cells
5
to its constant exposure to environmental hazards, cells in such as NK cells, can be used to identify the aging process.
this region, including buccal epithelial cells and immune Since the majority of human pathogens are transmitted
6,7
cells, such as natural killer (NK) cells, are particularly across mucosal surfaces, including the oral mucosae,
8
valuable for studying genetic and epigenetic changes. studying oral immunity and the role of NK cells in
Research on oral epithelial cells and oral immunity offers defending against pathogens is essential. Buccal mucosal
8
significant potential for identifying biomarkers of genetic cells can be collected using cotton swabs, cytobrushes,
damage, assessing the impacts of aging, and understanding the “swish and spit” method, or a modified version of
29
susceptibility to age-related diseases. By exploring genetic the Guthrie card for research related to identifying
5
changes within these cells, researchers may gain insights biomarkers and assessing risk factors such as exposure to
into the mechanisms of aging and develop strategies for the environmental hazards.
early detection of age-related conditions.
3. Environmental exposure
2. Buccal mucosa Humans are exposed to inherited, nutritional, and

30
The oral mucosal epithelium acts as a barrier between environmental health risks. Potentially harmful
31
the underlying tissues and the external environment, substances or situations, termed hazards, can cause
5
protecting the body from chemical, microbial, and physical toxic effects. 32,33 These substances may be produced by
23
/
threats. The oral epithelium consists of basal, prickle, agents in the workplace and or be prevalent in industrial
9
intermediate, and superficial layers, which comprise areas, where they can induce mutations, cancer, and
30
structural, progenitor, and mature cells. Due to constant congenital defects. Toxic materials typically enter the
5,10
exposure to environmental forces, oral mucosal epithelial body by crossing barriers through dermal absorption,
cells undergo continuous shedding and renewal. 12,13 inhalation through the respiratory tract, or ingestion. 31,34-36
11
Homeostasis in this tissue is maintained by a rich source In occupational settings, inhalation is the most important
of epithelial stem cells. Cell division in the basal stem route of entry for toxic materials, followed by dermal
13
cells of the stratified squamous layer continuously replaces contact and ingestion. Ingestion is generally considered the
4
shedding cells. Newly generated cells by mitosis in the least important route of entry. Injection and ingestion are
11
31
basal layer of the oral epithelium migrate to the surface rare routes of chemical intake. It appears that ingestion
10
to replace the sloughed-off epithelial cells. Potential risk may offer some protective role against increased sensitivity
factors for genetic damage in buccal cells include reactive to certain materials, such as metals. 37,38 However, chemical
oxygen species (ROS), viruses, seasonal changes, lifestyle absorption more commonly occurs through other routes
factors, and chemical and physical conditions in residential such as dermal adsorption of corrosive or irritants through
and occupational settings. As buccal cells form the first the skin, respiratory tract, and eyes. 31
14
barrier to inhaled and ingested substances, 12,15,16 they can Hazards can cause toxicological effects, including lethal
serve as an alternative tissue source for monitoring the or irreversible non-lethal outcomes, such as mutagenic
genotoxic effects of chemical exposure 11,17,18 in occupational effects after repeated or long-term exposure. The health
and environmental settings. 19-21 effects of chemical exposures can be acute, chronic, local,
In addition, the fact that 92% of human cancers systemic, reversible, or irreversible. The adverse biological
originate in epithelial cells highlights their significance for effects of hazards are classified as very toxic, toxic, harmful,
31
research 20,22 and molecular studies. Furthermore, the direct corrosive, and irritant. Figure 1 illustrates the entry routes
exposure of buccal cells to environmental pollutants and and health effects of chemical exposures. The severity of
their capability to metabolize carcinogens into reactive damage caused by hazards depends on the toxicity level
chemicals make them excellent sources for monitoring of the chemicals, the duration of exposure, the route of
genotoxicity 22,23 and for examining the relationship between entry, and the individual’s susceptibility to chemical effects
occupational exposure and biomarkers. Accordingly, (Table 1).
24
buccal cells are an accessible source for investigating DNA Since toxic exposure in occupational environments can
damage. 25-27 Interestingly, unlike blood lymphocytes, cause numerous health problems, 32,33 early identification
chromosomal damage in buccal cells continues to increase of potential hazards is of utmost importance. Workplace
33
with age, potentially making them a valid biomarker for conditions and workers’ behaviors are two major factors that
aging and a valuable resource for investigating genotoxicity increase the risk of toxic damage. For example, activities
31
and cytotoxicity parameters. 28 such as washing hands with petrol and contaminated

Volume 3 Issue 4 (2024) 2 doi: 10.36922/gpd.4418