There exist
a variety of ways for scientists to go about studying aging. Ever since the
creation of the biology of aging as a field with the hope of addressing
emergent problems associated with global population aging, this complex subject
has triggered myriad scientific imaginations.
Some hold
that aging is a developmental stage, which manifests itself through breakdowns
of various physiological architectures, thus understanding aging relies on
studies in developmental biology. Others disagree, emphasizing the role of
environmental damages and errors in protective machinery of organisms. For
example, one research program studies the age-related dynamics between the processes
of the damage and repair of DNA, molecules that carry the information of life.
Yet others do not regard the mechanism of aging, whatever it is, is as
important as the physiological programs that ensure individual life span.
Centenarian genetics, and the molecular signaling triggered by caloric
restriction, fall into the category of studying biological basis of life span
and longevity, whose results often feed the drug development industry with
potential schemes of making “Elixir”.
In some
sense, even the most brilliant mind in biology can only grasp limited aspects
of aging. When a group of curious blinds poke around a big elephant, however
sensitive and discerning they are, what they learn largely depends on the
particular location of their footholds. In the case of biogerontologists, the
scientific footings are constrained by various theoretical predilections and
experimental arrangements. But still, where do those diverse footholds come
from?
The author
visited the Intramural Research Program of National Institute on Aging (NIA)
located in Baltimore for an afternoon this August, chatting with six
researchers there. Those conversations were initially intended to help explore
the landscape of aging research, and they turned out to shed light on the lineage
of various takes of aging among biogerontologists. As a nascent branch of
biology and biomedicine, the study of aging does not enjoy many researchers
trained native in the field. Most of them came to focus on aging from the
trajectory of their original studies, along with their former disciplinary
leanings. Consequently, the approaches in aging are often the fruits of
cross-fertilizations between the motive of studying aging and the methods from
branches of biology and biomedicine.
David
Schlessinger arranged the marriage between genomics and the study of
age-related disease. Having worked for his PhD in Harvard in the wake of the
discovery of the DNA “double helix” in the 1950s and thereafter a researcher in
the Pasteur Institute on gene regulatory expression in bacteria, Schlessinger
joked that he always ended up in the right place at the right time. His timely
contribution also includes a 10-year directorship of the Human Genome Center at
Washington University. Witnessing the unfolding of human genome, Shlessinger
regarded the technologies needed for genetic and genomic study on human aging
became mature. Geneticists could now identify the different genetic sequences
and expression patterns between phenotypically differed cohorts using chips and
locate relevant loci on chromosomes through database at researchers’
fingertips. In 1997, he undertook the position of Chief of the Laboratory of
Genetics in NIA. Working along the methods of genomics and population genetics,
he constructed X chromosome map, discovering a number of disease genes, some of
which related to human aging.
Other researchers also drew their methods largely from former experiences. Sige Zou focuses his research on the change of life span in fruit flies and round worms brought by dietary restriction (DR) and deprivation, which was related to his work before on such model organisms. Weidong Wang brought his expertise in biochemistry to the study of a progeric disease, Fanconi anemia. Yie Liu transferred her molecular study in cancer cells, with considerations on DNA repair and telomere maintenance, into the study of cells at the intersection of senescence and malignancy.
Developed
late relative to other subdisciplines of biology, the biology of aging became a
topic that engaged a variety of existing methods from other branches and
adapted them into its own utilization. The lack of consensus on the causes of
aging, and the prioritization of research on various age-related diseases
further expanded the purview of biology of aging, allowing researchers from
many fields wield their disciplinary skills. The discrete but multiple
scientific programs welcome alternatives in researching aging, which made
complementary studies possible. However, also due to this status quo, the
limited resources of aging research are dispersed into scattered efforts, which
may inhibit the productivity and efficiency of the truly important approaches.
In addition, how to connect the dots derived from various approaches into a
coherent understanding of aging is an issue yet to resolve. A tentative
question is whether it is possible to combine various approaches and melt them
down to a grand methodology of aging research in biology, without compromising
the current richness and diversity. Before those questions are answered, the
biology of aging will continue to display its exceptional chirography in
theoretical diversity and experimental multiplicity on its scientific frontier.
About the author:
Lijing Jiang is a doctoral student in Biology and Society and is a
participant in CSPO’s research cluster Alternative
Imaginations. She maintains a blog Science
in a Mirror.
