Using primate neural stem cells cultured in self-assembling peptide nanofiber scaffolds to repair injured spinal cords in rats.

STUDY DESIGN: Transplanted primates' neural stem cells (NSCs) tissue engineering complex into spinal cord injury (SCI) model rats, analyze and evaluate the long-term effects of repairing. OBJECTIVES: Primate NSCs were cultured in self-assembling peptide nanofiber scaffolds to repair SCI. SETTING: Sun Yat-sen Memorial Hospital, Guangzhou, China. METHODS: Primate NSCs were isolated and cultured in self-assembling peptide nanofiber scaffolds. T10 SCI model was established; the rats were randomly divided into four groups: NSC plus self-assembling peptide scaffold group; NSC group; self-assembling peptide scaffold group; and control group. Immunohistochemical staining and electronic microscope were used to investigate the growth and differentiation of transplanted NSCs. The motor function of the hind limbs of rats was evaluated (P<0.05 was considered as statistically significant). RESULTS: NSCs and NSCs cultured in self-assembling peptide nanofiber scaffolds could be induced to differentiation into neurons, glial cells and oligodendrocytes in vitro. The primate NSC culture was established in self-assembling peptide scaffolds. No significant difference was seen in the differentiation rate between primate NSCs cultured in self-assembling peptide nanofiber scaffolds and primate NSCs cultured in regular medium. The motor function of the hind limbs in the NSC plus self-assembling peptide scaffold group was significantly better than that of the other three groups. In addition, the NSCs of the NSC group mainly differentiated into astrocytes. CONCLUSION: Transplantation of primate NSCs cultured in self-assembling peptide scaffolds is efficient for repairing the injured spinal cord and for improving the motor function of spinal cord in rats. SPONSORSHIP: The National Natural Science Foundation of China; Science and Technology Office of Guangdong Province.

Neurotrophin-3 stimulates migration of mesenchymal stem cells overexpressing TrkC.

BACKGROUND AND PURPOSE: Transplantation/infusion of mesenchymal stem cells (MSCs) is a promising new approach for treatment of spinal cord injury (SCI). Considering some defined chemokines of MSCs that may have adverse side effects in SCI repair, it is therefore desirable to search for a new chemokine, which should not only be harmless to the host, but also would attract more MSCs to the injury area of spinal cord. This study sought to demonstrate if neurotrophin- 3 (NT-3) would attract migration of MSCs with overexpressing tyrosine kinase C (TrkC) a NT-3 receptor. EXPERIMENTAL APPROACH: A micropipette containing NT-3 was placed in cell culture dish. After this, movement of TrkC gene modified MSCs was monitored for 240 min under an inverted microscope equipped with an imaging system. In vivo, a gelatin sponge scaffold containing TrkC gene modified MSCs was transplanted into the injury area of transected rat spinal cord. Following this, replication-deficient recombinant adenoviral vectors carrying human NT-3 gene (Ad-NT-3) was injected 1 mm caudal to the transplantation site to create an NT-3 enriched area. KEY RESULTS: The results showed that TrkC overexpressing MSCs migrated actively towards the source of NT-3 in the NT-3+TrkC-GFP-MSCs group in vitro. A similar phenomenon was not observed in the control groups. In vivo, transplanted MSCs overexpressing TrkC migrated into the NT-3 enriched area. The incidence of migrating MSCs as well as migration distance was significantly higher than the control groups. CONCLUSION AND IMPLICATIONS: The present results suggest that NT-3 may play a role in attracting MSCs with its high affinity for TrkC as a chemokine receptor.

A new combined therapeutic strategy of governor vessel electro-acupuncture and adult stem cell transplantation promotes the recovery of injured spinal cord.

Spinal cord injury (SCI) is a very severe traumatic disease of the central nervous system (CNS). Because of its high incidence rate in causing disabilities, it brings great burdens to patients and society. Both Traditional Chinese Medicine (TCM) and Western Medicine have been adopted to ameliorate SCI with promising outcomes. In TCM, the use of Governor Vessel electro-acupuncture has achieved remarkable results on the rehabilitation of patients with SCI. In the past decade, Governor Vessel electro-acupuncture has also been used in experimentally induced SCI and this has resulted in promising functional recovery. Both neural stem cells (NSCs) and bone marrow mesenchymal cells (MSCs) have been used extensively in recent years for improvement of functional recovery of CNS disorders. We have used a combined approach by integrating the basic and clinical research in SCI in recent years. In this connection, transplantation of NSCs or MSCs coupled with the Governor Vessel electro-acupuncture (GV-EA) has been adopted to improve the recovery of SCI. Our study suggests that GV-EA may activate the process of cell metabolism, and initiate synthesis and secretion of endogenous neurotrophic factors in the ambient tissues at the lesion site of spinal cord. It is proposed that the new combined strategy could promote a better structural and functional recovery of injured spinal cord.

Cotransplant of neural stem cells and NT-3 gene modified Schwann cells promote the recovery of transected spinal cord injury.

STUDY DESIGN: An animal model of transected spinal cord injury (SCI) was used to test the hypothesis that cografted neural stem cells (NSCs) and NT-3-SCs promote morphologic and functional recoveries of injured spinal cord. OBJECTIVE: To explore whether cotransplant of NSCs and NT-3-SCs could promote the injured spinal cord repair. SETTING: Zhongshan Medical College, Sun Yat-sen University, PR China. METHODS: Female Sprague-Dawley (SD) rats weighing on 200-220 g were used to prepare SCI models. The spinal cord was transected between T(9) and T(10), then NSCs, SCs+NSCs, LacZ-SCs+NSCs, or NT-3-SCs+NSCs were grafted into the transected site. RESULTS: (1) Part of NSCs could differentiate to neuron-like cells in the transected site and the percentage of differentiation was NT-3-SCs+NSCs group>SCs+NSCs group>NSCs group. (2) In the grafted groups, there were 5-HT, CGRP, and SP positive nerve fibres within the transected site. Some fluorogold (FG)-labeled cells were found in the spinal cord rostral to the transected site, the red nuclei and the inner pyramidal layer of sensorimotor cortex. (3) The cells grafted could enhance the injured neurons survival in inner pyramidal layer of sensorimotor cortex, red nuclei of midbrain, and Clark's nuclei of spinal cord's L1 segment, could decrease the latency and increase the amplitude of cortical somatosensory evoked potential (CSEP) and cortical motor evoked potential (CMEP), and could promote partly structural and functional recovery of the SCI rats. CONCLUSION: These results demonstrate that cografted NT-3-SCs and NSCs is a potential therapy for SCI. SPONSORSHIP: This research was supported by Chinese National Key Project for Basic Research (G1999054009), Chinese National Natural Science Foundation (30270700) and Social Developmental Foundation of Guangdong Province (2003C33808) to YS Zeng; Natural Science Foundation of Guangdong Province (04300468) and Medical Science Research Grant of Guangdong Province (A2004081) to JS Guo.

Single-assay combination of Epstein-Barr Virus (EBV) EBNA1- and viral capsid antigen-p18-derived synthetic peptides for measuring anti-EBV immunoglobulin G (IgG) and IgA antibody levels in sera from nasopharyngeal carcinoma patients: options for field screening.

Assessment of immunoglobulin A (IgA) antibody responses to various Epstein-Barr virus (EBV) antigen complexes, usually involving multiple serological assays, is important for the early diagnosis of nasopharyngeal carcinoma (NPC). Through combination of two synthetic peptides representing immunodominant epitopes of EBNA1 and viral capsid antigen (VCA)-p18 we developed a one-step sandwich enzyme-linked immunosorbent assay (ELISA) for the specific detection of EBV reactive IgG and IgA antibodies in NPC patients (EBV IgG/IgA ELISA). Sera were obtained from healthy donors (n = 367), non-NPC head and neck cancer patients (n = 43), and biopsy-proven NPC patients (n = 296) of Indonesian and Chinese origin. Higher values of optical density at 450 nm for EBV IgG were observed in NPC patients compared to the healthy EBV carriers, but the large overlap limits its use for NPC diagnosis. Using either EBNA1 or VCA-p18 peptides alone IgA ELISA correctly identified 88.5% and 79.8% of Indonesian NPC patients, with specificities of 80.1% and 70.9%, whereas combined single-well coating with both peptides yielded sensitivity and specificity values of 90.1 and 85.4%, respectively. The positive and negative predictive values (PPV and NPV, respectively) for the combined EBNA1 plus VCA EBV IgA ELISA were 78.7% and 93.9%, respectively. In the Indonesia panel, the level of EBV IgA reactivity was not associated with NPC tumor size, lymph node involvement, and metastasis stage, sex, and age group. In the China panel the sensitivity/specificity values were 86.2/92.0% (EBNA1 IgA) and 84.1/90.3% (VCA-p18 IgA) for single-peptide assays and 95.1/90.6% for the combined VCA plus EBNA1 IgA ELISA, with a PPV and an NPV for the combined EBV IgA ELISA of 95.6 and 89.3%, respectively. Virtually all NPC patients had abnormal anti-EBV IgG diversity patterns as determined by immunoblot analysis. On the other hand, healthy EBV carriers with positive EBV IgA ELISA result showed normal IgG diversity patterns. By using EBV IgG immunoblot diversity as confirmation assay for EBV IgA ELISA-positive samples, the sensitivity and specificity for NPC diagnosis increased to 98% and 99.2%, respectively, in the Indonesian NPC samples. The use of these combined methods for seroepidemiological screening studies is proposed.