Mesenchymal stem cell-derived apoptotic bodies alleviate alveolar bone destruction by regulating osteoclast differentiation and function / 国际口腔科学杂志·英文版

Periodontitis is caused by overactive osteoclast activity that results in the loss of periodontal supporting tissue and mesenchymal stem cells (MSCs) are essential for periodontal regeneration. However, the hypoxic periodontal microenvironment during periodontitis induces the apoptosis of MSCs. Apoptotic bodies (ABs) are the major product of apoptotic cells and have been attracting increased attention as potential mediators for periodontitis treatment, thus we investigated the effects of ABs derived from MSCs on periodontitis. MSCs were derived from bone marrows of mice and were cultured under hypoxic conditions for 72 h, after which ABs were isolated from the culture supernatant using a multi-filtration system. The results demonstrate that ABs derived from MSCs inhibited osteoclast differentiation and alveolar bone resorption. miRNA array analysis showed that miR-223-3p is highly enriched in those ABs and is critical for their therapeutic effects. Targetscan and luciferase activity results confirmed that Itgb1 is targeted by miR-223-3p, which interferes with the function of osteoclasts. Additionally, DC-STAMP is a key regulator that mediates membrane infusion. ABs and pre-osteoclasts expressed high levels of DC-STAMP on their membranes, which mediates the engulfment of ABs by pre-osteoclasts. ABs with knock-down of DC-STAMP failed to be engulfed by pre-osteoclasts. Collectively, MSC-derived ABs are targeted to be engulfed by pre-osteoclasts via DC-STAMP, which rescued alveolar bone loss by transferring miR-223-3p to osteoclasts, which in turn led to the attenuation of their differentiation and bone resorption. These results suggest that MSC-derived ABs are promising therapeutic agents for the treatment of periodontitis.

The modified peroneal artery perforator-based propeller flap for the reconstruction of distal lower extremity defect / 中华显微外科杂志

Objective To explore the feasibility and clinical effect of modified peroneal artery perforatorbased propeller flap which excludes small saphenous vein and sural nerve for coverage of the soft tissue defects of the ankle and foot.Methods From January,2009 to August,2013,20 patients with soft tissue defects of the foot or ankle underwent the procedures of reconstruction.After the proper perforators being identified with doppler sonography,the propeller flap was designed,which selected the location where terminal perforator vessels perforate deep fascia as the pivot point,the line from this point to the point where the second perforator near the wound around the line from the midpopliteal point to the midpoint of the achilles tendon and lateral malleolus perforated the deep facia as the axis.The flap was raised above the level of the deep fascia.The small extrinsic vessels around the sural nerve and small saphenous vein were contained in the flap,while the small saphenous vein and sural nerve were kept in the original position.The donor site was closed directly.The skin flaps measured from 7 cm × 4 cm to 21 cm × 7 cm.Results All 20 flaps survived completely without complications.During 10-28 months' followed-up (average 13 months),all flaps showed good texture matches and contour.All patients recovered walking and shoe wearing function.No one showed sensory disturbances at the lateral foot.Conclusion The modified peroneal artery perforator-based propeller flap excluding small saphenous vein and sural nerve still has stable blood supply,which is an idea way for covering skin and soft tissue defects in foot and ankle.