Rabbit Anti-Human Collagen I Polyclonal antibody

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.

Basal cell carcinoma (BCC) is a malignant skin tumor originating from cells of the epidermal basal layer and adnexal epithelium, especially in sun-exposed areas. Unlike squamous cell carcinoma (SCC), BCC has a propensity to grow only locally possibly due to differences in the surrounding microenvironment including the basement membrane (BM) and stroma. To investigate the components constituting the BM and surrounding connective tissue in BCC and SCC, we analyzed the expression of BM proteins, nidogen 1 (NID1) and type IV collagen (COL4). We compared the immunohistochemical expressions of NID1 and COL4 among tumor specimens from BCC, SCC and its precancerous condition, actinic keratosis (AK), (n=5 each condition). The expressions of NID1 and COL4 were both decreased around the tumor nest of SCC. In contrast, the expressions of both NID1 and COL4 around the nest of BCC were much higher than in the peri-lesional normal skin not only at the BM, but also in the surrounding stromal tissue. Our findings imply that the surrounding stromal cells of BCC, but not SCC or AK, excessively produce NID1 and COL4, which may be involved in preventing BCC cells from destroying the BM and invading the dermis.