Dr. Calvert's lab is studying how the cilia on photoreceptors, small organelles that contain important signaling machinery, regulate molecular movement and localization and how genetic mutations that interrupt these processes lead to blinding diseases.
Over the last decade hundreds of genetic mutations that lead to devastating, multiple organ diseases, including those causing blindness, deafness, cancer, kidney disease, obesity, mental retardation and many others, have been attributed to genes that are responsible for the construction, maintenance and signaling of cilia. Together, these diseases are known as ciliopathies.
Like many cells in the body, photoreceptors in the eye possess cilia. Photoreceptors begin the transformation of light into the electrical activity in the brain that is vision within their cilia. Dr. Calvert's lab uses sophisticated microscopy techniques and mathematical models to understand how cilia work, and what goes wrong in ciliopathic diseases.
"Understanding how cells and cilia regulate the movement of molecules is of paramount importance for finding therapies and cures for the debilitating and life-threatening ciliopathic diseases", says Dr. Calvert.
Why is this research important?
Hundreds of mutations in genes important for ciliary construction and functions lead to diseases that impact multiple organs. A particularly devastating example is Bardet-Biedl syndrome, where affected individuals lose their vision through a form of retinitis pigmentosa and may become obese, be mentally retarded, have extra digits at birth and have renal failure. Another example is Usher syndrome , which is characterized by deafness followed by slow loss of vision. Leber congenital amaurosis , a disease that causes severe vision loss at or soon after birth and central nervous system deficits that cause developmental delay, seizures, and motor skill impairment in some patients, also results from mutations in genes thought to be important for normal cilia function. Many forms of Retinitis pigmentosa result from mutations in ciliary proteins that also cause patients to suffer loss of hearing, mental retardation and birth defects.
Studying how cilia are constructed and maintained in normal cells and how mutations in genes cause them to malfunction is essential to finding therapies and cures for these blinding and multiple organ diseases.
Ciliopathies result in:
- Loss of vision, either at birth or slowly over a person’s lifetime.
- Loss of hearing.
- Birth defects of the eyes and other parts of the body.
- Mental deficits, either mild or more severe.
- Seizure disorders or epilepsy.
What are Ciliopathies?
Ciliopathies are diseases that result from mutations in genes that cause cilia to malfunction. Cilia are small organelles that are found on most cells in the body. Most cilia are very thin, hair-like projections from the surface of cells and are thought to act as antennas that sense the cell's environment. Mutations in genes that are involved in the construction, maintenance and transport of molecules to, from and within cilia can cause the cells to die, leading to tissue degeneration as is found in retinitis pigmentosa, or to abnormally divide, leading to some types of cancer.