複雜的
衰老
機理
By Wing In Chau
鄒穎姸
A
GING
The Intricacies of
Chromosome
染色體
Telomeres
端粒
As cells divide over time...
隨著時間，細胞分裂 ...
...telomeres shorten, and eventually
cell division stops.
... 端粒縮短，最終細胞停止分裂。
Cell
細胞
Nucleus
細胞核
The
fountain of youth is a quest that
has transcended time and cultures. Applying
modern technology to this mission has multiplied
the types of products available on the market
claiming to reverse aging. In the next few years,
the global anti-aging industry is expected to grow
into a US$346 billion market [1]. Most products
at the consumer level target the symptoms or
appearance of aging, but researchers may have
made significant discoveries toward understanding
the root of aging.
To tackle aging, it is important to understand
what aging is. Biological functions rely on a
cycle of cell division and cell death. This process,
however, is finite and cells cannot divide forever.
Every division involves cellular timekeepers, known
as telomeres, located at the end of chromosomes.
After numerous cell divisions, telomeres become
shor ter and eventually reach thei r minimum
length, where cells will no longer be able to divide
and lose its original function. These dysfunctional
cells can contribute to the process of aging in
a negative way. In 2014, scientists Timothy M.
Tucey and Victoria Lundblad published a study
of a cellular on-and-off “switch” that controls
the mechan i sm of telomere shor ten i ng [2].
The mechanism involves an enzyme known as
telomerase, which bears the ability to reconstruct
telomeres. They discovered that telomerase could
be switched on and off, which could prolong
the telomere shortening process and achieve
continuous tissue regeneration [2]. Harnessing this
technology has the potential to regenerate vital
organs in old age, and lead to the development of
treatments for aging related diseases.
Current anti-aging ‘remedies’ can be divided
into two main categories –
in-vivo
supplement
and appearance restorers. The former is carried
out by hormone replacement therapy, claiming to
increase one’s metabolic rate. However, no official
investigations have thus far been able to support
the claim that hormonal replacement therapy can
extend one’s lifespan or prevent age-related frailty
[3]. On the contrary, certain studies have reported
that this type of therapy may cause harmful side
effects, such as increased risk of breast cancer,
cardiovascular diseases, and stroke [4]. On the
