Faculty Bibliography

Senior housestaff and junior faculty are often expected to perform clinical research, yet may not always have the requisite knowledge and skills to do so successfully. Formal degree programs provide such knowledge, but require a significant commitment of time and money. Short-term training programs (days to weeks) provide alternative ways to accrue essential information and acquire fundamental methodological skills. Unfortunately, published information about short-term programs is sparse. To encourage discussion and exchange of ideas regarding such programs, we here share our experience developing and implementing INtensive Training in Research Statistics, Ethics, and Protocol Informatics and Design (INTREPID), a 24-day immersion training program in clinical research methodologies. Designing, planning, and offering INTREPID was feasible, and required significant faculty commitment, support personnel and infrastructure, as well as committed trainees. Clin Trans Sci 2014; Volume #: 1-7.

Bisphosphonates inhibit osteoclast differentiation/function via inhibition of Rap1A isoprenylation. As Rap1 is the effector of exchange protein directly activated by cAMP (EPAC) proteins, we determined the role of EPAC in osteoclast differentiation. We examined osteoclast differentiation as the number of primary murine/human bone-marrow precursors that differentiated into multinucleated TRAP-positive cells in the presence of EPAC-selective stimulus (8-pCTP-2'-O-Me-cAMP, 100 muM; 8-pCTP-2'-O-Me-cAMP-AM, 1 muM) or inhibitor brefeldin A (BFA), ESI-05, and ESI-09 (10 muM each). Rap1 activity was assessed, and signaling events, as well as differentiation in EPAC1/2-knockdown RAW264.7 cells, were studied. Direct EPAC1/2 stimulation significantly increased osteoclast differentiation, whereas EPAC1/2 inhibition diminished differentiation (113+/-6%, P<0.05, and 42+/-10%, P<0.001, of basal, respectively). Rap1 activation was maximal 15 min after RANKL stimulation (147+/-9% of basal, P<0.001), whereas silencing of EPAC1/2 diminished activated Rap1 (43+/-13 and 20+/-15% of control, P<0.001) and NFkB nuclear translocation. TRAP-staining revealed no osteoclast differentiation in EPAC1/2-KO cells. Cathepsin K, NFATc1, and osteopontin mRNA expression decreased in EPAC1/2-KO cells when compared to control. RhoA, cdc42, Rac1, and FAK were activated in an EPAC1/2-dependent manner, and there was diminished cytoskeletal assembly in EPAC1/2-KO cells. In summary, EPAC1 and EPAC2 are critical signaling intermediates in osteoclast differentiation that permit RANKL-stimulated NFkB nuclear translocation and actin rearrangements. Targeting this signaling intermediate may diminish bone destruction in inflammatory arthritis.-Mediero, A., Perez-Aso, M., Cronstein, B. N. Activation of EPAC1/2 is essential for osteoclast formation by modulating NFkappaB nuclear translocation and actin cytoskeleton rearrangements.