Study of pregnant rat maternal serum effects on chondrogenesis in osteoarthritis in vitro model

Fetomaternal Microchimerism defined as the presence of fetal cells inside the maternal circulation during pregnancy. Our study addressed its possible regenerative capacity role for osteoarthritis (OA) invitro by challenging its chondrogenesis ability on the osteoarthritic chondrocyte that harvested from an osteoarthritic patient. After primary culturing the chondrocyte from an OA patient, cells were subcultured on a 24-well plate and divided into four different groups for study. Our examination group composed of the cells treated with pregnant rat maternal serum (PRMS). For comparison, we considered a main, negative, and positive control groups by not adding anything extra than normal complete medium, adding non-pregnant rat serum (NPRS), and adding Hanks' Balanced Salt with calcium and magnesium solution respectively. All of the independent variabilities added at the same time and for 10% of total media in culture plates. We consider the same add-on amount for the main control group from the normal complete medium as well. After the subculturing day, cell media were refreshed with the same explained method for the next 10 days. On the day 11th wells were fixed and stained with Alician blue, Sirius Red, and Alizarin red for evaluating chondroitin and keratan sulfate, collagen, and calcium deposition respectively. The cellular morphology, chondron processes' length, cell and chondron counts were also considered as comparison factors in our study. The group treated with PRMS shown much higher cell and chondron counts, less chondron process length, and higher Sirius red stain (P.Values: Collagen staining intensity<0.001, chondron count<0.000, chondron length<0.015). In addition, we found better qualitative data in PRMS treated group as cellular and chondron geometric morphology (Polygonality), normal chondrocyte similar shapes with good amount and distribution in the intraterritorial and extracellular matrixes as well as less chondroptosis. Pregnant maternal serum shown its potential to being considered as a promising therapeutic way for OA treatment.