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Home > Faculty
> Xiaohua Gong
Reseach Interests
Research in our lab has been directed toward the study of molecular
and cellular mechanisms that control vertebrate organ-genesis and
diseases, mainly, eye development and ocular diseases, by using
multidisciplinary techniques from the fields of molecular and cellular
biology, genetics, biochemistry, and electrophysiology, etc.
We are particularly interested in the identification and characterization
of novel genetic factors that play essential roles in the development
of the eye as well as in pathological process of diseases such as
retinal degeneration, vascular disorders, and cataract.
Ultimately, we’d like to develop additional biological and
chemical tools to diagnose, prevent or cure related human eye diseases.
Current Projects
Eye Development and Diseases: This research involves a
forward genetic approach to identify and characterize the genes
that play essential roles in eye development and diseases. An ENU-induced
saturation mutagenesis mouse program in C57BL/6J strain has been
screened for ocular phenotypes by clinical examinations using an
indirect ophthalmoscope and a slit lamp. Defined genetic mutants
were subjected to chromosomal mapping of their mutations using a
genome wide mapping strategy. Their ocular phenotypes were further
characterized morphologically and biochemically.
So far, more than dozens eye mutations have been identified. These
mutants develop clinical symptoms like yellow spots, white spots
or hyperpigmentation in the retina, lens cataracts, corneal dystrophies,
respectively. Further analyses verified distinctive cellular and
molecular alterations in each mutation.
For example, morphological data showed abnormal aggregations between
retinal pigment epithelium and photoreceptor cells, a loss of outer
segment of photoreceptor cells, selective death of photoreceptor
cells, and a loss of cells in the inner nuclear layer in the eyes
of two dominant and two recessive retinal mutations respectively.
We are continuing to study the molecular and cellular mechanisms
in these mutants that develop similar ocular disorders as in human.
The Lens Biology: This research involves the studies
of cell-to-cell communication and intracellular signaling pathways
in the lens. The development of vertebrate lens uses a sophisticated
cell-cell communication network via gap junction channels, which
are made up of at least three connexin isoforms, alpha8 (Cx50),
alpha3 (Cx46) and alpha1 (Cx43). A gap junction channel is formed
by the docking of two hemichannels called “connexons”
from adjacent cells. Each connexon consists of 6 subunit proteins
called “connexins.”
So far, at least 20 different connexin genes have been reported
in this multi-gene family from humans and mice. The mutations of
different connexin genes have been reported to be linked to many
different human diseases, including cataracts, hearing loss, heart
diseases, and neurodegeneration.
The MAP kinase pathways have been reported to mediate two major
extracellular cues to regulate intracellular responses: growth stimuli
and environmental stresses. We have found that three distinctive
MAP kinase pathways are utilized in the differentiation process
of lens epithelial cells into fiber cells in the mouse lens and
have established a database of lens gene expression and proteins
by using DNA chip technology and proteomic technique like multi-dimensional
mass-spectrometry.
So far, we have identified hundreds of proteins in human lens epithelium
isolated from cataract patients and in the lens fibers from human
and mice.
We are trying to define specific posttranslational modifications
of downstream targets that are regulated by different MAP kinase
pathways in lens.
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