Spinal cord injury elicits an inflammatory response that recruits macrophages to the injured spinal cord. Quantitative real-time PCR results have shown that a repair strategy combining peripheral nerve grafts with acidic fibroblast growth factor (aFGF) induced higher interleukin-4 (IL-4), IL-10, and IL-13 levels in the graft areas of rat spinal cords compared with transected spinal cords at 10 and 14 d. This led to higher arginase I-positive alternatively activated macrophage (M2 macrophage) responses. The gene expression of several enzymes involved in polyamine biosynthesis pathways was also upregulated in the graft areas of repaired spinal cords. The treatment induced a twofold upregulation of polyamine levels at 14 d, as confirmed by HPLC. Polyamines are important for the repair process, as demonstrated by the observation that treatment with inhibitors of arginase I and ornithine decarboxylase attenuates the functional recoveries of repaired rats. After 14 d, the treatment also induced the expression of neurotrophin nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), as well as M2 macrophages within grafted nerves expressing BDNF. IL-4 was upregulated in the injury sites of transected rats that received aFGF alone compared with those that received nerve grafts alone at 10 d. Conversely, nerve graft treatment induced NGF and BDNF expression at 14 d. Macrophages expressing polyamines and BDNF may benefit axonal regeneration at 14 d. These results indicate that aFGF and nerve grafts regulate different macrophage responses, and M2 macrophages may play an important role in axonal regeneration after spinal cord injury in rats.

Citrus grandis (L.) Osbeck (red wendun) leaves have been used in traditional Chinese medicine to treat several illnesses including diabetes. However, there is no scientific evidence supporting these actions and its active compounds. Two flavone glycosides, rhoifolin and cosmosiin were isolated for the first time from red wendun leaves and, identified these leaves are rich source for rhoifolin (1.1%, w/w). In differentiated 3T3‐L1 adipocytes, rhoifolin and cosmosiin showed dose‐dependent response in concentration range of 0.001–5 μM and 1–20 μM, respectively, in biological studies beneficial to diabetes. Particularly, rhoifolin and cosmosiin at 0.5 and 20 μM, respectively showed nearly similar response to that 10 nM of insulin, on adiponectin secretion level. Furthermore, 5 μM of rhoifolin and 20 μM of cosmosiin showed equal potential with 10 nM of insulin to increase the phosphorylation of insulin receptor‐β, in addition to their positive effect on GLUT4 translocation. These findings indicate that rhoifolin and cosmosiin from red wendun leaves may be beneficial for diabetic complications through their enhanced adiponectin secretion, tyrosine phosphorylation of insulin receptor‐β and GLUT4 translocation.

S: Background: Spinal cord injury (SCI) is a complex and severe neurological condition. Mesenchymal stem cells (MSCs) and their secreted factors show promising potential for regenerative medicine. Many studies have investigated MSC expansion efficacy of all kinds of culture medium formulations, such as growth factor-supplemented or xeno-free medium. However, very few studies have focused on the potential of human MSC (hMSC) culture medium formulations for injured spinal cord repair. In this study, we investigated the effect of hMSC-conditioned medium supplemented with bFGF, EGF, and patient plasma, namely, neural regeneration laboratory medium (NRLM), on SCI in vitro and in vivo.Methods: Commercial and patient bone marrow hMSCs were obtained for cultivation in standard medium and NRLM separately. Several characteristics, including CD marker expression, differentiation, and growth curves, were compared between MSCs cultured in standard medium and NRLM. Additionally, we investigated the effect of the conditioned medium (referred to as NRLM-CM) on neural repair, including inflammation inhibition, neurite regeneration, and spinal cord injury (SCI), and used a coculture system to detect the neural repair function of NRLM-MSCs.Results: Compared to standard culture medium, NRLM-CM had superior in inflammation reduction and neurite regeneration effects in vitro and improved functional restoration in SCI rats in vivo. In comparison with standard culture medium MSCs, NRLM-MSCs proliferated faster regardless of the age of the donor. NRLM-MSCs also showed increased adipose differentiative potential and reduced CD90 expression. Both types of hMSC CM effectively enhanced injured neurite outgrowth and protected against H₂O₂toxicity in spinal cord neuron cultures. Cytokine arrays performed in hMSC-CM further revealed the presence of at least 120 proteins. Among these proteins, 6 demonstrated significantly increased expression in NRLM-CM: adiponectin (Acrp30), angiogenin (ANG), HGF, NAP-2, uPAR, and IGFBP2.Conclusions: The NRLM culture system provides rapid expansion effects and functional hMSCs. The superiority of the derived conditioned medium on neural repair shows potential for future clinical applications.

Chondroitin sulfate proteoglycans (CSPGs) are glial scar-associated molecules considered axonal regeneration inhibitors and can be digested by chondroitinase ABC (ChABC) to promote axonal regeneration after spinal cord injury (SCI). We previously demonstrated that intrathecal delivery of low-dose ChABC (1 U) in the acute stage of SCI promoted axonal regrowth and functional recovery. In this study, high-dose ChABC (50 U) introduced via intrathecal delivery induced subarachnoid hemorrhage and death within 48 h. However, most SCI patients are treated in the sub-acute or chronic stages, when the dense glial scar has formed and is minimally digested by intrathecal delivery of ChABC at the injury site. The present study investigated whether intraparenchymal delivery of ChABC in the sub-acute stage of complete spinal cord transection would promote axonal outgrowth and improve functional recovery. We observed no functional recovery following the low-dose ChABC (1 U or 5 U) treatments. Furthermore, animals treated with high-dose ChABC (50 U or 100 U) showed decreased CSPGs levels. The extent and area of the lesion were also dramatically decreased after ChABC treatment. The outgrowth of the regenerating axons was significantly increased, and some partially crossed the lesion site in the ChABC-treated groups. In addition, retrograde Fluoro-Gold (FG) labeling showed that the outgrowing axons could cross the lesion site and reach several brain stem nuclei involved in sensory and motor functions. The Basso, Beattie and Bresnahan (BBB) open field locomotor scores revealed that the ChABC treatment significantly improved functional recovery compared to the control group at eight weeks after treatment. Our study demonstrates that high-dose ChABC treatment in the sub-acute stage of SCI effectively improves glial scar digestion by reducing the lesion size and increasing axonal regrowth to the related functional nuclei, which promotes locomotor recovery. Thus, our results will aid in the treatment of spinal cord injury.