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In recent years, bone marrow-derived cells have been found to be crucial for peripheral nerve regeneration. After traumatic peripheral nerve injury, bone marrow-derived macrophages quickly infiltrate into the distal regions of nerves. To explore the changes caused by bone marrow-derived cells within the proximal regions of the nerves, sciatic nerves of chimeric mice carrying bone marrow cells expressing green fluorescent protein were crushed to observe the infiltration of invading bone marrow-derived cells. Seven days after surgery, abundant bone marrow-derived cells had infiltrated into the damaged proximal nerve segments. The numbers of these cells increased to a peak at 2 weeks and then gradually returned to normal levels within 30 weeks. Through immunofluorescence staining, many of these cells were identified as macrophages, and they showed a similar infiltration tendency toward distal nerve segments. However, fewer cells infiltrated proximal segments than distal nerve segments. In conclusion, these findings suggest that bone marrow-derived cells response not only occurs within the distal nerve segments but may also take place within the proximal segments of nerve tissues after nerve injury.

// Zhen Gao 1 , Yu-Qing Jin 2 , Wei Wu 1 1 Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China 2 Department of Plastic Surgery, Shanghai International Medical Center, Shanghai, China Correspondence to: Wei Wu, email: babevivi@126.com Keywords: alopecia areata, SOCS3, IFN-γ, autoimmune, hair follicle Received: October 02, 2016 Accepted: February 23, 2017 Published: March 23, 2017 ABSTRACT Alopecia areata is one of the most common autoimmune diseases resulting from T cell-mediated damage of hair follicles. CD8+ T cells infiltrate hair follicles and are responsible for destruction of hair follicles. However the underlying mechanisms for hair loss remain still obscure. In the present study, we identified that suppressor of cytokine signaling-3 (SOCS3), a classical inhibitor of cytokine signaling, significantly inhibits CD8+T cell maturation, interferon-γ (IFN-γ) production and alopecia areata. SOCS3 is downregulated in the skin of alopecia areata patients and murine autoimmune alopecia model. Furthermore, SOCS3 treatment prevents the development of alopecia areata in the graft model. SOCS3 decreases the CD44 high CD62L low effector memory CD8+ T cells, resulting in the decrease of IFN-γ production. The expression of Fas and major histocompatibility complex-1 (MHC I) is upregulated in skin from C3H/HeJ alopecia areata mice, and this increase is suppressed by SOCS3. The SOCS3 level is negative correlation with the Fas and MHC I level in patients with alopecia areata. These results suggest that SOCS3 treatment may be an effective strategy to treat autoimmune alopecia as well as to more generally prevent cytokine-dependent tissue destruction in inflammatory diseases.

A variety of nerve conduits incorporated with chemical and biological factors have been developed to further stimulate nerve regeneration. Although most of the nerve guides in studies are basically limited to bridge a short gap of nerve defect in rat models, it is vital to evaluate effects of conduits on nerve regeneration over distance greater than 20 mm, or more clinically relevant nerve gap lengths in higher mammals. In this study, a poly(lactide-co-glycolide) (PLGA) nerve conduit, treated with pulsed plasma and coated with ciliary neurotrophic factor (CNTF) as well as chitosan, was used to repair 25-mm-long canine tibial nerve defects in eighteen cross-bred dogs. The canines were randomly divided into three groups (n = 6), a 25-mm segment of the tibial nerve was removed and replaced by a PLGA/chitosan-CNTF nerve conduit, PLGA/chitoson conduit and autologous nerve grafts were performed as the control. The results were evaluated by general observation, eletromyogram testing, S-100 histological immunostaining, and image analysis at 3 months after operation. The histological results demonstrated that the PLGA/chitosan-CNTF conduits and PLGA/chitosan conduits were capable of leading the damaged axons through the lesioned area. Through the comparation of the three groups, the results in PLGA/chitosan-CNTF conduits group were better than that of PLGA/chitosan conduits group, while they were similar to autologous nerve grafts group. Therefore, CNTF-coated PLGA/chitosan nerve conduits could be an alternative artificial nerve conduit for nerve regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.