Transplanting p75-suppressed bone marrow stromal cells promotes functional behavior in a rat model of spinal cord injury

Stem cell transplantation and functional recovery after spinal cord injury: a systematic review and meta-analysis

Spinal cord injury is a significant cause of motor dysfunctions. There is no definite cure for it, and most of the therapeutic modalities are only symptomatic treatment. In this systematic review and meta-analysis, the effectiveness of stem cell therapy in the treatment of the spinal cord injuries in animal models was studied and evaluated. A systematic search through medical databases by using appropriate keywords was conducted. The relevant reports were reviewed in order to find out cases in which inclusion and exclusion criteria had been fulfilled. Finally, 89 articles have been considered, from which 28 had sufficient data for performing statistical analyses. The findings showed a significant improvement in motor functions after cell therapy. The outcome was strongly related to the number of transplanted cells, site of injury, chronicity of the injury, type of the damage, and the induction of immune-suppression. According to our data, improvements in functional recovery after stem cell therapy in the treatment of spinal cord injury in animal models was noticeable, but its outcome is strongly related to the site of injury, number of transplanted cells, and type of transplanted cells.

Combination of RNA Interference and Stem Cells for Treatment of Central Nervous System Diseases

RNA interference (RNAi), including microRNAs, is an important player in the mediation of differentiation and migration of stem cells via target genes. It is used as a potential strategy for gene therapy for central nervous system (CNS) diseases. Stem cells are considered vectors of RNAi due to their capacity to deliver RNAi to other cells. In this review, we discuss the recent advances in studies of RNAi pathways in controlling neuronal differentiation and migration of stem cells. We also highlight the utilization of a combination of RNAi and stem cells in treatment of CNS diseases.

Coadministration of Dexamethasone and Melissa officinalis Has Neuroprotective Effects in Rat Animal Model with Spinal Cord Injury

Objective

Spinal cord injury (SCI) causes inflammation, deformity and cell loss. It has been shown that Melissa officinalis (MO), as herbal medicine, and dexamethasone (DEX) are useful in the prevention of various neurological diseases. The present study evaluated combinational effects of DEX and MO on spinal cord injury.

Materials and Methods

Thirty six adult male Wistar rats were used in this experimental study. The weight-drop contusion method was employed to induce spinal cord injury in rats. DEX and MO were administrated alone and together in different treatment groups. Intra-muscular injection of DEX (1 mg/kg) was started three hours after injury and continued once a day for seven days after injury. Intra-peritoneal (I.P) injection of MO (150 mg/ kg) was started one day after injury and continued once a day for 14 days.

Results

Our results showed motor and sensory functions were improved significantly in the group received a combination of DEX and MO, compared to spinal cord injury group. Mean cavity area was decreased and loss of lower motor neurons and astrogliosis in the ventral horn of spinal cord was significantly prevented in the group received combination of DEX and Melissa officinalis, compared to spinal cord injury group. Furthermore, the findings showed a significant augmentation of electromyography (EMG) recruitment index, increase of myelin diameter, and up-regulation of myelin basic protein in the treated group with combination of DEX and MO.

Conclusion

Results showed that combination of DEX and MO could be considered as a neuroprotective agent in spinal cord injury.

Exogenous Expression of Nt-3 and TrkC Genes in Bone Marrow Stromal Cells Elevated the Survival Rate of the Cells in the Course of Neural Differentiation

Bone marrow stromal cells (BMSCs) are attractive cellular sources for cell therapy of many diseases, specifically neurodegenerative ones. The potential capability of BMSCs could be further augmented by enhancing their neuroprotective property, differentiation potential, and survival rate subsequent to transplantation. Therefore, a concurrent upregulation of neurotrophin-3 (NT-3) and its high affinity receptor, tyrosin kinase C (TrkC), was utilized in our study. BMSCs were cotransfected with pDsRed1-N1-NT-3 and pCMX-TrkC plasmids before induction of neural differentiation. pEGFP-N1-transfected BMSCs were also employed as a control. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was employed for gene expression analysis. Cell viability was evaluated by MTT assay, while apoptosis rate was assessed by flow cytometry after PI and Annexin V staining. NT-3 and TrkC mRNA levels were greatly elevated following cotransfection of cells with pDsRed1-N1-NT-3 and pCMX-TrkC vectors. The expression of neural markers (i.e., NFM, and NeuroD1) was augmented in cotransfected BMSCs, compared to the control ones, after neural induction. At each time point, the viability and apoptosis rates of the cells over-expressing NT-3 and TrkC showed increased and reduced patterns, respectively. Our data demonstrated that NT-3/TrkC-co-transfected BMSCs, compared to those of intact cells, could be more beneficial graft candidates for the upcoming treatment strategies of neurogenic disorders due to their increased viability and expression of neural markers. This may be due to their increased level of neural differentiation potential and/or their enhanced rate of survival and/or their useful capacity to secrete NT-3.

Assessment of Neuroprotective Properties of Melissa officinalis in Combination With Human Umbilical Cord Blood Stem Cells After Spinal Cord Injury

INTRODUCTION

The pathophysiology of spinal cord injury (SCI) has a classically bad prognosis. It has been demonstrated that human umbilical cord blood stem cells (hUCBSCs) and Melissa officinalis (MO) are useful for the prevention of neurological disease.

METHODS

Thirty-six adult male rats were randomly divided into intact, sham, control (SCI), MO, hUCBSC, and MO-hUCBSC groups. Intraperitoneal injection of MO (150 mg/kg) was commenced 24 hr post-SCI and continued once a day for 14 days. Intraspinal grafting of hUCBSCs was commenced immediately in the next day. The motor and sensory functions of all animals were evaluated once a week after the commencement of SCI. Electromyography (EMG) was performed in the last day in order to measure the recruitment index. Immunohistochemistry, reverse transcription-polymerase chain reaction, and transmission electron microscopy evaluations were performed to determine the level of astrogliosis and myelination.

RESULTS

The results revealed that motor function (MO-hUCBSC: 15 ± 0.3, SCI: 8.2 ± 0.37, p < .001), sensory function (MO-hUCBSC: 3.57 ± 0.19, SCI: 6.38 ± 0.23, p < .001), and EMG recruitment index (MO-hUCBSC: 3.71 ± 0.18, SCI: 1.6 ± 0.1, p < .001) were significantly improved in the MO-hUCBSC group compared with SCI group. Mean cavity area (MO-hUCBSC: 0.03 ± 0.03, SCI: 0.07 ± 0.004, p < .001) was reduced and loss of lower motor neurons (MO-hUCBSC: 7.6 ± 0.43, SCI: 3 ± 0.12, p < .001) and astrogliosis density (MO-hUCBSC: 3.1 ± 0.15, SCI: 6.25 ± 1.42, p < 0.001) in the ventral horn of spinal cord were prevented in MO-hUCBSC group compared with SCI group.

CONCLUSION

The results revealed that the combination of MO and hUCBSCs in comparison with the control group has neuroprotective effects in SCI.

VGF (TLQP-62)-induced neurogenesis targets early phase neural progenitor cells in the adult hippocampus and requires glutamate and BDNF signaling

The neuropeptide VGF (non-acronymic), which has antidepressant-like effects, enhances adult hippocampal neurogenesis as well as synaptic activity and plasticity in the hippocampus, however the interaction between these processes and the mechanism underlying this regulation remain unclear. In this study, we demonstrate that VGF-derived peptide TLQP-62 specifically enhances the generation of early progenitor cells in nestin-GFP mice. Specifically, TLQP-62 significantly increases the number of Type 2a neural progenitor cells (NPCs) while reducing the number of more differentiated Type 3 cells. The effect of TLQP-62 on proliferation rather than differentiation was confirmed using NPCs in vitro; TLQP-62 but not scrambled peptide PEHN-62 increases proliferation in a cell line as well as in primary progenitors from adult hippocampus. Moreover, TLQP-62 but not scrambled peptide increases Cyclin D mRNA expression. The proliferation of NPCs induced by TLQP-62 requires synaptic activity, in particular through NMDA and metabotropic glutamate receptors. The activation of glutamate receptors by TLQP-62 activation induces phosphorylation of CaMKII through NMDA receptors and protein kinase D through metabotropic glutamate receptor 5 (mGluR5). Furthermore, pharmacological antagonists to CaMKII and PKD inhibit TLQP-62-induced proliferation of NPCs indicating that these signaling molecules downstream of glutamate receptors are essential for the actions of TLQP-62 on neurogenesis. We also show that TLQP-62 gradually activates Brain-Derived Neurotrophic Factor (BDNF)-receptor TrkB in vitro and that Trk signaling is required for TLQP-62-induced proliferation of NPCs. Understanding the precise molecular mechanism of how TLQP-62 influences neurogenesis may reveal mechanisms by which VGF-derived peptides act as antidepressant-like agents.