Pathophysiology of osteoarthritis (OA) is characterized by progressive loss of articular cartilage in the knee-joints. To impart regenerative ability in lowly metabolizing chondrocytes, the bone marrow stem cells (BMSCs) has recently been recognized as a superior alternative treatment for OA. However, study of primary BMSCs-mediated chondrogenesis is difficult due to progressive cellular aging and replicative senescence. To obtain a therapeutic cell population for OA, BMSCs were immortalized by human papilloma virus (HPV)-16 E6/E7 along with mCherry luciferase (mCL), a gene marker for non-invasive imaging, and designated as iBMSCs-mCL. Next, their cell morphology, population doubling time (PDT) and colony forming ability (CFU) were evaluated. Furthermore, pluripotency and immunophenotypic markers were investigated. To deduce therapeutic ability, iBMSCs-mCL were intra-articularly injected into right knee of anterior cruciate ligament transaction (ACLT)-OA mice model and tracked through non-invasive bioluminescence imaging. Cell morphology of iBMSCs-mCL was similar to parental BMSCs. PDT and CFU ability of iBMSCs-mCLs were significantly increased. Pluripotency and immunophenotypic markers were highly expressed in iBMSC-mCL. Long-term survival and tri-lineage differentiation particularly chondrogenic potential of iBMSCs-mCL were also demonstrated in vitro and then in vivo which was monitored through non-invasive imaging. Intensive bioluminescent signals in iBMSCs-mCL administered knee-joint indicated a marked in vivo survival and proliferation of iBMSCs-mCL. Immunohistochemical staining for type II collagen (IHC of Col II) and alcian blue & safranin o staining of proteoglycans also corroborated cartilage regeneration by iBMSCs-mCL. Conclusively, iBMSCs-mCL maintains stemness and in vivo cartilage regeneration potential suggesting a promising avenue for development of OA therapeutics.

Benign prostatic hyperplasia (BPH) is the most common urologic disease among elderly men. A well-established in vitro cell model is required to determine the therapeutic mechanism of BPH inflammation. In this study, we attempted to establish an immortalized human prostate stromal cell line by transfecting with HPV-16 E6/E7 and designated as ihPSC. No significant difference was found in fibroblast-like morphology between primary hPSC and ihPSC. The ihPSC possessed a significantly higher cell proliferation rate than primary hPSC. The prostate-specific markers and proteins including cytoskeleton (α-SMA and vimentin) and smooth muscle (calponin), especially the androgen receptor (AR) were also examined in ihPSC, almost identical to the primary hPSC. To create an in vitro model featuring chronic prostatic inflammation, ihPSC was stimulated with IFN-γ+IL-17 and then treated with the high molecular weight hyaluronic acid hylan G-F 20 as an alternative strategy for inhibiting BPH inflammation. Hylan G-F 20 could dose-dependently diminish the inflammation-induced proliferation in ihPSC. The enhanced expressions of inflammatory molecules including IL-1β, IL-6, IL-8, cyclooxygenase 2 (COX2), inducible nitrogen oxide synthase (iNOS), and Toll-like receptor 4 (TLR4) were all abolished by hylan G-F 20. For inflammatory signaling, hylan G-F 20 can also diminish the IFN-γ+IL-17-increased expression of iNOS and p65 in ihPSC. These findings suggest that ihPSC could provide a mechanism-based platform for investigating prostate inflammation. The hylan G-F 20 showed strong anti-inflammatory effects by decreasing inflammatory cytokines and signalings in the ihPSC, indicating its therapeutic potentials in BPH treatment in the future.