Differentiation of GDNF and NT-3 dual gene-modified rat bone marrow mesenchymal stem cells into enteric neuron-like cells

Promoting Immortalized Adipose-Derived Stem Cell Transdifferentiation and Proliferation into Neuronal-Like Cells through Consecutive 525 nm and 825 nm Photobiomodulation

Neuronal cells can be generated from adipose-derived stem cells (ADSCs) through biological or chemical inducers. Research has shown that this process may be optimized by the introduction of laser irradiation in the form of photobiomodulation (PBM) to cells. This in vitro study is aimed at generating neuronal-like cells with inducers, chemical or biological, and at furthermore treating these transdifferentiating cells with consecutive PBM of a 525 nm green (G) laser and 825 nm near-infrared (NIR) laser light with a fluence of 10 J/cm². Cells were exposed to induction type 1 (IT1): 3-isobutyl-1-methylxanthine (IBMX) (0.5 mM)+indomethacin (200 μM)+insulin (5 μg/ml) for 14 days, preinduced with β-mercaptoethanol (BME) (1 mM) for two days, and then incubated with IT2: β-hydroxyanisole (BHA) (100 μM)+retinoic acid (RA) (10-6 M)+epidermal growth factor (EGF) (10 ng/ml)+basic fibroblast growth factor (bFGF) (10 ng/ml) for 14 days and preinduced with β-mercaptoethanol (BME) (1 mM) for two days and then incubated with indomethacin (200 μM)+RA (1 μM)+forskolin (10 μM) for 14 days. The results were evaluated through morphological observations, viability, proliferation, and migration studies, 24 h, 48 h, and 7 days post-PBM. The protein detection of an early neuronal marker, neuron-specific enolase (NSE), and late, ciliary neurotrophic factor (CNTF), was determined with enzyme-linked immunosorbent assays (ELISAs). The genetic expression was also explored through real-time PCR. Results indicated differentiation in all experimental groups; however, cells that were preinduced showed higher proliferation and a higher differentiation rate than the group that was not preinduced. Within the preinduced groups, results indicated that cells treated with IT2 and consecutive PBM upregulated differentiation the most morphologically and physiologically.

The bone marrow-derived mesenchymal stem cells (BMSCs) alleviate diabetic peripheral neuropathy induced by STZ via activating GSK-3β/β-catenin signaling pathway

BACKGROUND

Diabetic peripheral neuropathy, a common complication of diabetic mellitus, has brought a threaten on patients' health. The bone marrow-derived mesenchymal stem cells (BMSCs) were reported to play an important role in diverse diseases. Nevertheless, the specific function of BMSCs in diabetic peripheral neuropathy remained uncharacterized.

METHODS

A wide range of experiments including RT-qPCR, western blot, H&E staining, oxidative stress assessment, measurement of thermal sensitivity, ELISA, urine protein and CCK-8 assays were implemented to explore the function and mechanism of BMSCs in vivo and vitro.

RESULTS

The experimental results displayed that BMSCs improve STZ-induced diabetes symptoms in rats by decreasing blood glucose and urinary protein. Functionally, BMSCs ameliorate oxidative stress, painful diabetic neuropathy, neurotrophic status and angiogenesis in STZ-induced rats. Moreover, BMSCs participate in the regulation of sciatic neuro morphology in diabetic neuropathy rat model. In mechanism, BMSCs alleviate diabetic peripheral neuropathy via activating GSK-3β/β-catenin signaling pathway in rats and improve Schwann's cells viability by activating GSK-3β/β-catenin signaling pathway under high glucose.

CONCLUSIONS

We verified that BMSCs alleviate diabetic peripheral neuropathy of rats induced by STZ via activating GSK-3β/β-catenin signaling pathway, which implied a novel biomarker for diabetic peripheral neuropathy treatment.

The treatment of spinal cord injury in rats using bone marrow-derived neural-like cells induced by cerebrospinal fluid

This study aimed to evaluate the effect of bone mesenchymal stem cells (BMSCs) and BMSC neural-like cells (BMSC-Ns) on the spinal cord injury (SCI) in the rat model of SCI. BMSC-Ns were prepared from the third passage of BMSCs by induction of healthy cerebrospinal fluid (CSF) of an adult human. The SCI rat model was established through a surgical procedure, and after 7 days the rats were randomly divided into 3 (A, B and C) groups. Groups A (BMSC-Ns) and B (BMSCs) were treated with 1 × 10⁶/20 μl cells, while group C (saline) was treated with saline, all via intracerebroventricular injection. After transplantation, the BBB score of group A was significantly higher than that of group B, which in turn was significantly higher than that of group C (P < .05). The levels of Bdnf, Ngf, Ntf3 were statistically significantly higher in group A than those in groups B and C (P < .05). The levels of 5-HT, NA, Ach, DA, GABA in group A were significantly higher than those in groups B and C, whereas the level of Glu was significantly lower in group A than that in groups B and C (P < .05). The histopathological data showed remarkably less necrosis of the spinal cord in group A, compared to that in groups B and C. Transplanting BMSC-Ns or BMSCs into the lateral ventricles improved the neurological function of rats with SCI. Moreover, BMSC-Ns were significantly more effective than BMSCs, which provides a possible approach for the treatment of SCI.

MicroRNA-211 causes ganglion cell dysplasia in congenital intestinal atresia via down-regulation of glial-derived neurotrophic factor

BACKGROUND

MicroRNAs (miRNAs) are known to be involved in normal brain functions and nervous system diseases. Some evidence have pointed to the dysregulation of miRNAs in congenital intestinal atresia. In this study, we investigated the differential expression of miRNAs and the posttranscriptional regulation of glial-derived neurotrophic factor (GDNF) by endogenous miRNA in congenital intestinal atresia.

METHODS

Quantitative real-time PCR and a Western blot were performed to determine the regulation of miRNA and GDNF in patients with congenital intestinal atresia. The results were verified in rat model of intestinal atresia and bone marrow derived stem cell BMSCs-derived into intestinal ganglion cells. The effects of miRNA and GDNF on the cell proliferation and apoptosis of isolated intestinal ganglion cells were detected with an 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium (MTT) assay and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively.

KEY RESULTS

Only miR-211 was greatly up-regulated in the patients with congenital intestinal atresia. The other miRNAs examined showed no change. Overexpression of miR-211 suppressed the differentiation of BMSCs into intestinal ganglion cells. In retinal ganglion cells (RGC-5 cells), miR-211 regulated the expression of GDNF. The MTT and TUNEL assays revealed that miR-211 overexpression suppressed the cell proliferation of isolated intestinal ganglion cells and that GDNF overexpression reversed the effect of pre-miR-211 on cell proliferation and apoptosis.

CONCLUSIONS & INFERENCES

Our results indicate that overexpression of miR-211 suppresses the differentiation of BMSCs into intestinal ganglion cells by directly down-regulating the expression of GDNF. The findings elucidate the role of miRNA in congenital intestinal atresia.

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine

Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

Effects of brain‑derived neurotrophic factor and neurotrophin‑3 on the neuronal differentiation of rat adipose‑derived stem cells

Tissue engineering is a promising method that may be used to treat spinal cord injury (SCI). The underlying repair mechanism of tissue engineering involves the stable secretion of neurotrophins from seed cells, which eventually differentiate into neurons; therefore, the selection of appropriate seed cells, which stably secrete neurotrophins that easily differentiate into neurons requires investigation. Adipose‑derived stem cells (ADSCs), which are adult SCs, are advantageous due to convenience sampling and easy expansion; therefore, ADSCs are currently the most popular type of seed cell. Brain‑derived neurotrophic factor (BDNF) and neurotrophin‑3 (NT‑3) possess superior properties, when compared with other neurotrophic factors, in the maintenance of neuronal survival and promotion of SC differentiation into neurons. The present study used two lentiviruses, which specifically express BDNF and NT‑3 [Lenti‑BDNF‑green fluorescent protein (GFP), Lenti‑NT‑3‑red fluorescent protein (RFP)], to transfect third‑generation ADSCs. Three types of seed cell were obtained: i) Seed cells overexpressing BDNF (ADSC/Lenti‑BDNF‑GFP); ii) seed cells overexpressing NT‑3 (ADSC/Lenti‑NT‑3‑RFP); and iii) seed cells overexpressing BDNF and NT‑3 (ADSC/Lenti‑BDNF‑GFP and NT‑3‑RFP). The transfected cells were then induced to differentiate into neurons and were divided into a further four groups: i) The BDNF and NT‑3 co‑overexpression group; ii) the BDNF overexpression group; iii) the NT‑3 overexpression group; and iv) the control group, which consisted of untransfected ADSCs. The results of the present study demonstrate that BDNF and NT‑3 expression was higher 10 days after induction, as detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Neuron‑specific enolase is a neuronal marker, the expression of which was highest in the BDNF and NT‑3 co‑overexpression group, followed by the BDNF overexpression group and then by the NT‑3 overexpression group. The lowest expression levels of NSE were detected in the control group, as determined by RT‑qPCR, western blotting and immunofluorescent staining. These results indicate that BDNF and NT‑3 exert a synergistic effect, which may promote the neuronal differentiation of ADSCs. The present study provides a solid theoretical foundation for future experiments regarding the use of tissue engineering technology for the treatment of SCI.

GDNF and NT-3 induce progenitor bone mesenchymal stem cell differentiation into neurons in fetal gut culture medium

With the increasing use of bone marrow mesenchymal stem cells (BMSCs) in cell therapies, factors regulating BMSC differentiation have become the interest of current research. In this study, we investigated the effects of glial cell-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) on the course of BMSC differentiation. BMSCs were isolated from rat bone marrow and transfected with GDNF and NT-3 genes. Compared to mock-transfected BMSCs, GDNF and NT-3 induced BMSC differentiation to reveal neuron-like characteristics, i.e., the positive expression of neuronal marker MAP-2 and astrocyte marker GFAP, as detected by immunofluorescence assays. Semi-quantitative polymerase chain reaction (PCR) and western blot analyses showed that the increase of expression of GDNF and NT-3 in BMSCs also simultaneously elevated the mRNA expression of NSE, nestin, and MAP-2. Furthermore, the cell patch-clamp test demonstrated that the overexpression of GDNF and NT-3 in BMSCs enhanced voltage-activated potassium currents, implying that BMSCs possess great potential as a cell-based therapeutic candidate to treat neurological diseases.

In vivo tracking of neuronal-like cells by magnetic resonance in rabbit models of spinal cord injury

In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesenchymal stem cells can survive, migrate, integrate and help to restore the function and behaviors of spinal cord injury models, and that they may serve as a suitable approach to treating spinal cord injury. However, it is very difficult to track transplanted cells in vivo. In this study, we injected superparamagnetic iron oxide-labeled neuronal-like cells into the subarachnoid space in a rabbit model of spinal cord injury. At 7 days after cell transplantation, a small number of dot-shaped low signal intensity shadows were observed in the spinal cord injury region, and at 14 days, the number of these shadows increased on T2-weighted imaging. Perl's Prussian blue staining detected dot-shaped low signal intensity shadows in the spinal cord injury region, indicative of superparamagnetic iron oxide nanoparticle-labeled cells. These findings suggest that transplanted neuronal-like cells derived from bone marrow mesenchymal stem cells can migrate to the spinal cord injury region and can be tracked by magnetic resonance in vivo. Magnetic resonance imaging represents an efficient noninvasive technique for visually tracking transplanted cells in vivo.