Improvement of Contused Spinal Cord in Rats by Cholinergic-like Neuron Therapy

Trans-Differentiation of Human Dental Pulp Stem Cells Into Cholinergic-Like Neurons Via Nerve Growth Factor

Introduction:

Cell therapy has been widely considered as a therapeutic approach for neurodegenerative diseases and nervous system damage. Cholinergic neurons as one of the most important neurons that play a significant role in controlling emotions, mobility, and autonomic systems. In this study, Human Dental Pulp Stem Cells (hDPSCs) were differentiated into the cholinergic neurons by β-mercaptoethanol in the preinduction phase and also by the nerve growth factor (NGF) in the induction phase.

Methods:

The hDPSCs were evaluated for CD73, CD31, CD34, and Oct-4. Concentration-time relationships for NGF were assessed by evaluating the viability rate of cells and the immune response to nestin, neurofilament 160, microtubule-associated protein-2, and choline acetyltransferase.

Results:

The hDPSCs had a negative response to CD34 and CD31. The optimal dose for the NGF was 50 ng/mL seven days after the induction when the highest percentage of expressing markers for the Cholinergic neurons (ChAT) was detected.

Conclusion:

The results of this study provided a method for producing cholinergic neurons by hDPSCs, which can be used in cytotherapy for degenerative diseases of the nervous system and also spinal cord injury.

Evaluating Effect of Mesenchymal Stem Cells on Expression of TLR2 and TLR4 in Mouse DCs

PURPOSE

Mesenchymal stem cells (MSCs) are multipotent cells and recent findings suggest immunomodulatory effect of them on immune cells including T cells and dendritic cells (DCs). DCs are the most potent antigen presenting cells. It seems because of immunoregulatory properties of MSCs, they can affect the maturation and differentiation of DCs. DCs express a kind of surface receptors called toll-like receptors (TLRs) and play a key role in maturation process and activation of DCs. The aim of this study was to evaluate expression of TLR2 and TLR4 on DCs after exposure to mesenchymal stem cell's supernatant in culture media containing LPS and devoid of it.

METHODS

In this experimental study, MSCs and DCs were extracted from adult Balb/c mouse bone marrow and spleen, respectively. MSCs supernatant were collected 24 and 48 h after 5(th) passage, and in adjusted with DCs culture. Isolated DCs were co-cultured with MSCs supernatant, incubation time were 24 and 48 hours. mRNA levels of TLR2 and TLR4 were evaluated using real time PCR technique.

RESULTS

The results demonstrated that although, expressions of these two receptors were up-regulated in culture media lacking LPS in comparison with the control group but the increase was not significant. There were no significant associations between LPS stimulated DCs with and without MSCs supernatants.

CONCLUSION

According to the results presented here, it appears that TLR2 and TLR4 gene expressions on the DCs are not affected by MSCs supernatant.

The change tendency of PI3K/Akt pathway after spinal cord injury

Spinal cord injury (SCI) refers to the damage of spinal cord's structure and function due to a variety of causes. At present, many scholars have confirmed that apoptosis is the main method of secondary injury in spinal cord injury. In view of understanding the function of PI3K/Akt pathway on spinal cord injury, this study observed the temporal variation of key molecules (PI3K, Akt, p-Akt) in the PI3K/Akt pathway after spinal cord injury by immunohistochemistry and Western-blot. The results showed that the expression of PI3K, Akt and p-Akt display a sharp increase one day after the spinal cord injury, and then it decreased gradually with the time passing by, but the absolute expression was certainly higher than the normal group. These results indicate that the PI3K/Akt signaling pathway is involved in the spinal cord injury and the mechanism may be related to apoptosis.

Transplantation of neurotrophin-3-transfected bone marrow mesenchymal stem cells for the repair of spinal cord injury

Bone marrow mesenchymal stem cell transplantation has been shown to be therapeutic in the repair of spinal cord injury. However, the low survival rate of transplanted bone marrow mesenchymal stem cells in vivo remains a problem. Neurotrophin-3 promotes motor neuron survival and it is hypothesized that its transfection can enhance the therapeutic effect. We show that in vitro transfection of neurotrophin-3 gene increases the number of bone marrow mesenchymal stem cells in the region of spinal cord injury. These results indicate that neurotrophin-3 can promote the survival of bone marrow mesenchymal stem cells transplanted into the region of spinal cord injury and potentially enhance the therapeutic effect in the repair of spinal cord injury.