Differentiation of human umbilical cord-derived mesenchymal stem cells, WJ-MSCs, into chondrogenic cells in the presence of pulsed electromagnetic fields.

During cartilage regeneration, proliferation and differentiation of new chondrocytes are required and towards this goal, in humans electromagnetic stimulation has been used in order to increase the spontaneous regenerative capacity of bone and cartilage tissue. In vivo tissue engineering has pointed out that the absence of an abundant source of cells accelerating the healing process is a limiting factor in the ability to repair articular cartilage. Considering that the umbilical cord is a viable alternative source of mesenchymal stem cells (MSC), our study evaluated the possibility of a combined use of Wharton's jelly - mesenchymal stem cells (WJ-MSCs) and pulsed electromagnetic field (PMEF). The first effect observed was that compared with the untreated cells, when the WJ-MSCs were treated with PMEF, there was an increase in the division of cells and a rapid increase in cell density and the morphological and biochemical data showed that the treatment with PMEF reduced the time to obtain chondrocyte cell differentiation and deposition of extracellular matrix. Taken together these data indicate the capacity of PEMF to induce early differentiation of WJ-MSCs cells towards cartilaginous tissue.

Localization and modulation of NEDD8 protein in the human placenta.

BACKGROUND: Neural precursor cell-expressed, developmentally down-regulated-8 (NEDD8) is a 76-amino-acid ubiquitin-like polypeptide. NEDD8 affects the signaling of various molecules but the major cellular target proteins are cullins. The neddylation process is correlated closely with apoptosis, cell-cycle regulation, embryogenesis and development. AIM: The purpose of the present work was to investigate NEDD8 distribution and expression in the human placenta during gestation. MATERIALS AND METHODS: A total of 30 samples, 15 chorionic villous samples from first trimester and 15 from full-term placentae, were used for the immunohistochemical analysis of NEDD8 expression. The gestation period ranged from 5 to 40 weeks. RESULTS: NEDD8 was highly expressed in the cytotrophoblast of the first trimester of gestation, whereas in the third trimester, it was localized in the endothelial cells and stroma of placental villi. CONCLUSION: Our results suggest that NEDD8 may play an important role in the control of proliferation and differentiation of human placenta throughout pregnancy.

Suppression of pre adipocyte differentiation and promotion of adipocyte death by anti-HIV drugs.

In the present study, we investigated the ability of anti-HIV drugs to interfere with normal cell cycle progression and to induce oxidative stress by perturbing the redox environment. Our results provide evidence that anti-HIV drugs have a differential effect on adipocyte cell cycle and differentiation, being able to modify the response to oxidative stress through an increase of reactive oxygen species (ROS) that compromises the induction of phase-2 and antioxidant enzymes. In detail, saquinavir, efavirenz, and stavudine exert antiadipogenic influences on the model 3T3-L1 cell line, perturbing the oxidative response and inducing of apoptosis. When considered together, the effects of anti-HIV drugs on 3T3-L1 pre adipocytes are distinct but commonly antiadipogenic, thus suggesting another additional possible mechanism by which antiretroviral therapies could contribute to lipoatrophy.