Zebrafish Neurovascular Development: A Model for Human Cerebrovascular Disease
Primary Faculty Mentor’s Name
Vinoth Sittaramane, PhD
Proposal Track
Student
Session Format
Paper Presentation
Abstract
Zebrafish Neurovascular Development: A Model for Human Cerebrovascular Disease
Kayla Smith*, Louise Zehr*, Vinoth Sittaramane, PhD
(*indicates equal contribution and shared first authorship)
Vascular diseases are one of the leading causes of mortality in the United States and the world. Of particular importance is the cerebrovascular disease, which is primarily associated with senility. The World Health Organization estimates that cerebrovascular disease contributed to 5.5 million deaths globally (or 9.6% of all deaths) in 2001. Cerebrovascular disease is characterized by thinning cerebral blood vessel endothelia, which could lead to internal hemorrhaging, ischemia, stroke, and death. While the pathophysiology of the disease is well studied, the molecular signaling underlying the disease is largely unknown. Recently, human Integrin alpha 6 (ITGA6), a cell adhesion molecule, has been linked to cerebrovascular diseases, especially intracerebral hemorrhage. However, the role of ITGA6 in vascular development is known. Therefore, we wish to investigate the developmental contributions of itga6 by using zebrafish as a model system. Zebrafish have many advantages such as cost-effectiveness, transparent embryos, rapid development, and availability of genetic, molecular and pharmacological tools. When we examined zebrafish embryos that lacked itga6, we uncovered interesting phenotypical findings on morphology, neurovascular structure, and cellular migration patterns. On a gross level, the itga6 deficient phenotype was characterized by cerebral edema, cardiac edema, and truncated morphology. The neurovascular structure in the hindbrain was also significantly affected: endothelia appeared thinner, hemorrhaging appeared, and the embryos had fewer central arteries (CtAs) when compared to the control group. On a cellular level, we noted that the itga6 deficient blood vessels were wider and had higher numbers of protrusions growing from the CtAs. The blood vessel dilation could indicate a wider lumen or the lack of a lumen, which would account for hemorrhaging events. The elevated prevalence of projections indicate that the endothelial cells have lost their sense of direction, and are not properly forming a lumen but aggregating at certain points on the CtAs. These results indicated that itga6 holds a functional role in vascular development that is conserved in zebrafish. To compensate for the itga6 deficiency, we injected itga6 RNA to promote functional protein synthesis. We are able to rescue several neurovascular defects in itga6 deficient embryos. Many “rescue” embryos still lacked certain CtAs. We believe that the improved CtA prevalence and decreased protrusion counts in the “rescues” can be contributed to increased itga6 communication between the extracellular matrix and the cell membrane, thus encouraging proper endothelial migration patterns. These results indicate that itga6 is required for the neurovascular development in zebrafish embryos consistent with human role. Our future aims are to further investigating the methodology of hemorrhage formation during the itga6 deficient embryo development.
Keywords
Cerebrovascular disease, itga6 protein, Zebrafish, Hemorrhaging
Award Consideration
1
Location
Room 1909
Presentation Year
2014
Start Date
11-15-2014 8:30 AM
End Date
11-15-2014 9:30 AM
Publication Type and Release Option
Presentation (Open Access)
Recommended Citation
Smith, Kayla D., "Zebrafish Neurovascular Development: A Model for Human Cerebrovascular Disease" (2014). Georgia Undergraduate Research Conference (2014-2015). 4.
https://digitalcommons.georgiasouthern.edu/gurc/2014/2014/4
Zebrafish Neurovascular Development: A Model for Human Cerebrovascular Disease
Room 1909
Zebrafish Neurovascular Development: A Model for Human Cerebrovascular Disease
Kayla Smith*, Louise Zehr*, Vinoth Sittaramane, PhD
(*indicates equal contribution and shared first authorship)
Vascular diseases are one of the leading causes of mortality in the United States and the world. Of particular importance is the cerebrovascular disease, which is primarily associated with senility. The World Health Organization estimates that cerebrovascular disease contributed to 5.5 million deaths globally (or 9.6% of all deaths) in 2001. Cerebrovascular disease is characterized by thinning cerebral blood vessel endothelia, which could lead to internal hemorrhaging, ischemia, stroke, and death. While the pathophysiology of the disease is well studied, the molecular signaling underlying the disease is largely unknown. Recently, human Integrin alpha 6 (ITGA6), a cell adhesion molecule, has been linked to cerebrovascular diseases, especially intracerebral hemorrhage. However, the role of ITGA6 in vascular development is known. Therefore, we wish to investigate the developmental contributions of itga6 by using zebrafish as a model system. Zebrafish have many advantages such as cost-effectiveness, transparent embryos, rapid development, and availability of genetic, molecular and pharmacological tools. When we examined zebrafish embryos that lacked itga6, we uncovered interesting phenotypical findings on morphology, neurovascular structure, and cellular migration patterns. On a gross level, the itga6 deficient phenotype was characterized by cerebral edema, cardiac edema, and truncated morphology. The neurovascular structure in the hindbrain was also significantly affected: endothelia appeared thinner, hemorrhaging appeared, and the embryos had fewer central arteries (CtAs) when compared to the control group. On a cellular level, we noted that the itga6 deficient blood vessels were wider and had higher numbers of protrusions growing from the CtAs. The blood vessel dilation could indicate a wider lumen or the lack of a lumen, which would account for hemorrhaging events. The elevated prevalence of projections indicate that the endothelial cells have lost their sense of direction, and are not properly forming a lumen but aggregating at certain points on the CtAs. These results indicated that itga6 holds a functional role in vascular development that is conserved in zebrafish. To compensate for the itga6 deficiency, we injected itga6 RNA to promote functional protein synthesis. We are able to rescue several neurovascular defects in itga6 deficient embryos. Many “rescue” embryos still lacked certain CtAs. We believe that the improved CtA prevalence and decreased protrusion counts in the “rescues” can be contributed to increased itga6 communication between the extracellular matrix and the cell membrane, thus encouraging proper endothelial migration patterns. These results indicate that itga6 is required for the neurovascular development in zebrafish embryos consistent with human role. Our future aims are to further investigating the methodology of hemorrhage formation during the itga6 deficient embryo development.
