Bioinspired Nanofiber Scaffold for Differentiating Bone Marrow-Derived Neural Stem Cells to Oligodendrocyte-Like Cells: Design, Fabrication, and Characterization

BACKGROUND

Researchers are trying to study the mechanism of neural stem cells (NSCs) differentiation to oligodendrocyte-like cells (OLCs) as well as to enhance the selective differentiation of NSCs to oligodendrocytes. However, the limitation in nerve tissue accessibility to isolate the NSCs as well as their differentiation toward oligodendrocytes is still challenging.

PURPOSE

In the present study, a hybrid polycaprolactone (PCL)-gelatin nanofiber scaffold mimicking the native extracellular matrix and axon morphology to direct the differentiation of bone marrow-derived NSCs to OLCs was introduced.

MATERIALS AND METHODS

In order to achieve a sustained release of T3, this factor was encapsulated within chitosan nanoparticles and chitosan-loaded T3 was incorporated within PCL nanofibers. Polyaniline graphene (PAG) nanocomposite was incorporated within gelatin nanofibers to endow the scaffold with conductive properties, which resemble the conductive behavior of axons. Biodegradation, water contact angle measurements, and scanning electron microscopy (SEM) observations as well as conductivity tests were used to evaluate the properties of the prepared scaffold. The concentration of PAG and T3-loaded chitosan NPs in nanofibers were optimized by examining the proliferation of cultured bone marrow-derived mesenchymal stem cells (BMSCs) on the scaffolds. The differentiation of BMSCs-derived NSCs cultured on the fabricated scaffolds into OLCs was analyzed by evaluating the expression of oligodendrocyte markers using immunofluorescence (ICC), RT-PCR and flowcytometric assays.

RESULTS

Incorporating 2% PAG proved to have superior cell support and proliferation while guaranteeing electrical conductivity of 10.8 × 10-5 S/cm. Moreover, the scaffold containing 2% of T3-loaded chitosan NPs was considered to be the most biocompatible samples. Result of ICC, RT-PCR and flow cytometry showed high expression of O4, Olig2, platelet-derived growth factor receptor-alpha (PDGFR-α), O1, myelin/oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP) high expressed but low expression of glial fibrillary acidic protein (GFAP).

CONCLUSION

Considering surface topography, biocompatibility, electrical conductivity and gene expression, the hybrid PCL/gelatin scaffold with the controlled release of T3 may be considered as a promising candidate to be used as an in vitro model to study patient-derived oligodendrocytes by isolating patient's BMSCs in pathological conditions such as diseases or injuries. Moreover, the resulted oligodendrocytes can be used as a desirable source for transplanting in patients.

Nod-like receptor protein 3 and nod-like receptor protein 1 inflammasome activation in the hippocampal region of postmortem methamphetamine chronic user

OBJECTIVE AND BACKGROUND

Methamphetamine (Meth) is one of the most important central nervous system (CNS) stimulant abuse drugs that cause long-term or permanent damage to different regions of the brain, particularly hippocampus, by neuronal apoptosis and inflammation. In this study, we evaluated Nod-like Receptor Protein 3(NLRP3) and Nod-like Receptor Protein1 (NLRP1) Inflammasome Activation in the Hippocampal Region of postmortem Meth Chronic User.

METHODS

Molecular and histological analyses were conducted on the brain of 14 non-addicted and 11 Meth users separately. The expression level of NLRP1, NLRP3 was measured using western blotting and immunohistochemistry (IHC) techniques. Histopathological assessment was performed with stereological Cell Counting of hippocampal cells stained with hematoxylin and eosin (H et E). Moreover, Tunel staining was carried out in order to detect any kind of DNA damage.

RESULTS

Based on our findings using western blotting and immunohistochemistry assay, overexpression of NLRP1 and NLRP3 proteins in the hippocampal region of Meth addicts was observed. The stereological analysis in the hippocampus of the human brain revealed increased neurodegeneration. Furthermore, the increased rate of apoptosis and cell death were significant and confirmed by Tunel assay in the hippocampus of Meth groups.

CONCLUSION

Chronic Meth abuse could result in increases of NLRP1 and NLRP3 and induction of inflammation and apoptosis in the hippocampus in Meth groups (Tab. 1, Fig. 9, Ref. 40).

Evaluation of the effect of BMSCs condition media and methylprednisolone in TGF-β expression and functional recovery after an acute spinal cord injury

The purpose of this experimental study is evaluation of the effect of BMSCs Condition Media and Methylprednisolone in TGF-β expression and functional recovery after acute spinal cord injury in adult wistar rat.

MATERIAL AND METHODS

After an acute spinal cord injury, MP and BMSC-CM were injected intraperitoneally and the recovery rate was evaluated by BBB and narrow beam test. Real time PCR, H[et]E staining, cavity formation and stereology was done after 12 weeks post injury.

RESULT

There were significant differences in functional recovery between MP+CM group, relative to other groups. TGF-β1 expression decreased in MP+CM group compared to the control group. Cavity size in experimental groups decreased compared to the control group. The mean volume of spinal cord demonstrated a significant increase in the MP+CM group in comparison to the other experimental groups.

CONCLUSION

Simultaneous use of MP and BMSC-CM will improve recovery from the spinal cord injury, reduce inflammation and improve functional recovery (Tab. 1, Fig. 8, Ref. 26).

The Combined Effects of Mesenchymal Stem Cell Conditioned Media and Low-Level Laser on Stereological and Biomechanical Parameter in Hypothyroidism Rat Model

Introduction: Many studies have shown the positive effect of laser radiation and application of the mesenchymal stem cells (MSCs) and their secretion in stimulating bone regeneration. The aim of this study was determining effects of MSC conditioned media (CM) and low-level laser (LLL) on healing bone defects in the hypothyroid male rat. Methods: We assigned 30 male Wistar rats randomly to 3 groups: control, hypothyroidism, CM+LLL. Four weeks after surgery, the right tibia was removed. Biomechanical examination and histological examinations were performed immediately. Results: Our results showed significant increase in bending stiffness (116.09±18.49), maximum force (65.41±8.16), stress high load (23.30±7.14), energy absorption (34.57±4.10), trabecular bone volume (1.34±0.38) and the number of osteocyte, osteoblast, and osteoclast (12.77±0.54, 6.19±0.80, 1.12±0.16 respectively) in osteotomy site in the LLL+CM group compared to the hypothyroidism group (P<0.05). Conclusion: The results indicated that using the LLL + CM may improve fracture regeneration and it may hasten bone healing in the hypothyroid rat.