Longwave ultraviolet light induces the aging-associated progerin in melanocytes Sheila Firoozan BA, Hirotaka Takeuchi MS, Thomas Ruenger MD PhD Department of Dermatology, Boston University School of Medicine BACKGROUND METHODS CONCLUSION

Expose neonatal and adult melanocytes to UVA and UVB Hutchinson Gilford Syndrome (HGPS): radiation. • genetic disorder resulting in the premature aging of many organs, including the skin These results provide preliminary evidence that • skin abnormalities: progerin accumulation may play a role in • light brown spots on the neck, scalp, Isolate mRNA at 8hr and 24 hr time points. thorax and photoaging of the human pigmentary system. limbs, predominantly at sun exposed areas Use q RT-PCR to determine levels of gene expression of • hypopigmentated regions CBS News progerin relative to unexposed sham. • indurated, inelastic and sclerodermatous skin • highly visible veins • loss of subcutaneous fat • skin is thin, dry and atrophic, with RESULTS FUTURE PROJECTS hyperkeratosis and decreased turgor • caused by an autosomal dominant mutation in the Neonatal melanocytes LMNA gene, resulting in alternative splicing and 3 Question: Does UV radiation Question: Does UVA radiation

production of a mutant lamin A protein, progerin Hennekam R. Hutchinson-Gilford Progeria Syndrome: Review of the Phenotype. 2.5 • isolated fibroblasts from HGPS patients feature: American Journal of Medical Genetics, 2006: 2603-2624 induce accumulation of progerin induce the HGPS-like abnormal • misshapen nuclei 2 protein in human melanocytes? nuclear morphology in human • increased lobulation of the nuclear 1.5 melanocytes? envelope 1 • thickening of the Expose neonatal and adult 0.5 Expose neonatal and adult • recent studies revealed that cells of healthy, of Progerin Expression Relative melanocytes to UVA and UVB radiation. melanocytes to UVA and UVB elderly individuals acquire nuclear defects similar 0 sham UVA UVA UVB sham UVA UVA UVB radiation. to those observed in acquired from HGPS 5J/cm2 10J/cm2 180mJ/cm2 5J/cm2 10J/cm2 180mJ/cm2

patients, due to sporadic activation of the same 8 hours 24 hours cryptic splice site affected in HGPS Exposure Isolate progerin at 72hr time • suggests that the process of aging may be point. Hennekam R. Hutchinson-Gilford Progeria Syndrome: Review of the Phenotype. related to the production of progerin American Journal of Medical Genetics, 2006: 2603-2624 Neonatal Melanocytes - repeat experiment Stain melanocyte nuclei for protein 6 Perform a Western Blot to products of the Lamin A gene to 5 detect presence and quantity of assess nuclear morphology. Aging: 4 progerin relative to sham. • Intrinsic aging: progressive degeneration, similar to that observed in internal organs 3 • Photoaging: a form of extrinsic aging that results from 2 environmental exposure, especially ultraviolet radiation Relative Expression of Progerin Expression Relative 1 • Photoaging may accelerate processes involved with 0 intrinsic aging Sham UVA UVA UVB sham UVA UVA UVB • Unlike keratinocytes, which have a high turnover rate, 3J/cm2 5J/cm2 80mJ/cm2 3J/cm2 5J/cm2 80mJ/cm2 REFERENCES 24 hours melanocytes do not proliferate greatly , and thus may be 8 hours Exposure more likely to accumulate progerin over time. • Previous studies in our lab indicate that progerin El-Domyati M. et al. Intrinsic aging vs. photoaging: a comparative histopathological, Adult Melanocytes accumulates in fibroblasts, a cell population which similarly immunohistochemical, and ultrastructural study of skin. Experimental Dermatology. 11:398-405 6 (2002)

has a low proliferation rate 5 Goldman, RD. et al. Accumulation of mutant lamin A causes progressive changes in nuclear architecture in Hutchinson–Gilford progeria syndrome. PNAS. 101: 8963- Overall Goal: to determine if the skin hypopigmentation 4 8985, 2004 observed in photoaging due to melanocyte senescence is Hennekam RCM. Hutchinson–Gilford progeria syndrome: Review of the phenotype. Am J Med caused by UV-induced progerin accumulation 3 Genet Part A 140A:2603–2624 (2006) Skinsight.com Mazereeuw-Hautier, LC. Hutchinson–Gilford progeria syndrome: clinical findings 2 in three patients carrying the G608G mutation in LMNA and review of the literature. Br J Derm Relative Expression of Progerin of Progerin Expression Relative 156:1308-1314 (2007) 1 Ruenger T, Takeuchi. J Clin Derm. In print.

0 Scaffidi P. et al. Lamin A-Dependent Nuclear Defects in Human Aging. Science. 312: 1056-1063 sham UVA UVA UVA UVB sham UVA UVA UVA UVB (2006) QUESTION 3J/cm2 5J/cm2 8JJ/cm2 80mJ/cm2 3JJ/cm2 5JJ/cm2 8J/cm2 80mJ/cm2 8 hours 24 hours Exposure Does UV radiation induce expression of Funding for this research was provided by: UVA, but not UVB, induces progerin mRNA in neonatal The Medical Student Science Research Program progerin in human melanocytes? and adult melanocytes in a dose-dependent manner. at Boston University School of Medicine