Abstract
Purpose :
Lubricin is the body’s unique anti-adhesive, anti-fibrotic, anti-friction and anti-inflammatory glycoprotein. It is produced by numerous tissues, including the cornea, heart, lung, liver, cartilage, kidney, brain, testis, placenta and small intestine. At these locations lubricin may regulate a number of processes, such as homeostasis, shear stress, tissue development, inflammation and wound healing. We hypothesize that lubricin is also synthesized and expressed by the amniotic membrane (AM). Our rationale is that the AM possesses anti-adhesive, anti-fibrotic and anti-inflammatory properties, and promotes tissue redevelopment and wound healing. We believe that lubricin, at least in part, mediates these AM capabilities.
Methods :
We obtained ten de-identified samples of human AMs and positive control placentas from the Tissue Repository of the Massachusetts General Hospital Pathology Service (Boston). These tissues originated from healthy donors (29 to 38 years old) following Cesarean sections. Our studies were approved by the Human Studies Committee of the Massachusetts Eye and Ear Infirmary (Boston). We also obtained one cryopreservated (CP-AM) and five freeze-dried (FD-AM) AMs. The FD-AMs were evaluated with or without incubation overnight at 4°C with recombinant human (rh) lubricin (50 µl, 0.675 mg/ml, gift from Lµbris BioPharma, Framingham, MA). Samples were processed for immunofluorescence and Western blot analyses.
Results :
Our results demonstrate that all placental and AM samples contained lubricin. Lubricin was expressed in placental chorionic villi and AM epithelial and stromal cells. Lubricin was also present in CP-AM epithelia, but not in the FD-AMs. Lubricin expression could be restored in FD-AM after overnight incubation with rhlubricin.
Conclusions :
This study demonstrates that lubricin is expressed in human AMs, and that preservation methods influence the extent of this expression. Given lubricin's biological activities, it is possible that this glycoprotein may mediate, at least in part, the anti-adhesive, anti-fibrotic and anti-inflammatory properties of AMs.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.