Drusen in patient-derived hiPSC-RPE models of macular dystrophies
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Authors: Galloway, Chad A.; Dalvi, Sonal; Hung, Sandy S. C.; MacDonald, Leslie A.; Latchney, Lisa R.; Wong, Raymond C. B.; Guymer, Robyn H.; Mackey, David A.; Williams, David S.; Chung, Mina M.; Gamm, David M.; Pebay, Alice; Hewitt, Alex W.; Singh, Ruchira
Abstract
Age-related macular degeneration (AMD) and related macular dystrophies (MDs) are a major cause of vision loss. However, the mechanisms underlying their progression remain ill-defined. This is partly due to the lack of disease models recapitulating the human pathology. Furthermore, in vivo studies have yielded limited understanding of the role of specific cell types in the eye vs. systemic influences (e.g., serum) on the disease pathology. Here, we use human induced pluripotent stem cell-retinal pigment epithelium (hiPSC-RPE) derived from patients with three dominant MDs, Sorsby's fundus dystrophy (SFD), Doyne honeycomb retinal dystrophy/malattia Leventinese (DHRD), and autosomal dominant radial drusen (ADRD), and demonstrate that dysfunction of RPE cells alone is sufficient for the initiation of sub-RPE lipoproteinaceous deposit (drusen) formation and extracellular matrix (ECM) alteration in these diseases. Consistent with clinical studies, sub-RPE basal deposits were present beneath both control (unaffected) and patient hiPSC-RPE cells. Importantly basal deposits in patient hiPSC-RPE cultures were more abundant and displayed a lipid-and protein-rich "drusen-like" composition. Furthermore, increased accumulation of COL4 was observed in ECM isolated from control vs. patient hiPSC-RPE cultures. Interestingly, RPE-specific up-regulation in the expression of several complement genes was also seen in patient hiPSC-RPE cultures of all three MDs (SFD, DHRD, and ADRD). Finally, although serum exposure was not necessary for drusen formation, COL4 accumulation in ECM, and complement pathway gene alteration, it impacted the composition of drusen-like deposits in patient hiPSC-RPE cultures. Together, the drusen model(s) of MDs described here provide fundamental insights into the unique biology of maculopathies affecting the RPE-ECM interface.
Follicular dendritic cell-secreted protein gene expression is upregulated and spread in nifedipine-induced gingival overgrowth
ODONTOLOGY
Authors: Nakayama, Yohei; Inoue, Eiko; Kato, Ayako; Iwai, Yasunobu; Takai-Yamazaki, Mizuho; Tsuruya, Yuto; Yamaguchi, Arisa; Noda, Keisuke; Nomoto, Takato; Ganss, Bernhard; Ogata, Yorimasa
Abstract
Follicular dendritic cell-secreted protein (FDC-SP) is secreted protein expressed in follicular dendritic cells, periodontal ligament and junctional epithelium (JE). Its expression could be controlled during inflammatory process of gingiva; however, responsible mechanism for gingival overgrowth and involvement of FDC-SP in clinical condition is still unclear. We hypothesized that JE-specific genes are associated with the initiation of drug-induced gingival enlargement (DIGE) called gingival overgrowth, and investigated the changes of JE-specific gene's expression and their localization in overgrown gingiva from the patients. Immunohistochemical analysis revealed that the FDC-SP localization was spread in overgrown gingival tissues.FDC-SPmRNA levels in GE1 and Ca9-22 cells were increased by time-dependent nifedipine treatments, similar to other JE-specific genes, such asAmelotin(Amtn) andLaminin beta 3subunit (Lam beta 3), whereastype 4 collagen(Col4) mRNA levels were decreased. Immunocytochemical analysis showed that FDC-SP, AMTN, and Lam beta 3 protein levels were increased in GE1 and Ca9-22 cells. Transient transfection analyses were performed using luciferase constructs including various lengths of humanFDC-SPgene promoter, nifedipine increased luciferase activities of -345 and -948FDC-SPconstructs. These results raise the possibility that the nifedipine-induced FDC-SP may be related to the mechanism responsible for gingival overgrowth does not occur at edentulous jaw ridges.