Cardiac and hepatic side effects of fluoxetine in male and female adolescent rats

BACKGROUND

Fluoxetine (FLX) is widely prescribed as an antidepressant medicine in the juvenile population.

OBJECTIVES

Although some adverse effects of FLX have been reported in adults, the present study aimed to investigate the side effects of FLX treatment during adolescence on the cardiac and hepatic systems.

METHODS

Male and female rats were gavaged with FLX (5 mg/kg/day) on postnatal days (PND) 21 to PND 60. Following treatment, blood samples were collected and hepatic enzymes were evaluated. The specimens of the liver and heart of animals were subjected to histopathological assessment.

RESULTS

Fluoxetine significantly raised serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in males, whereas the aspartate aminotransferase (AST) level increased in both male and female animals. In the histopathological study, hepatic plates were more seriously affected, and the sinusoids were irregular in adolescent male rats. Degenerative changes were observed especially in the first and second hepatic zones of FLX-treated male rats. Signs of inflammation and accumulation of lymphoid groups were frequently observed in the portal triad of the hepatic lobules. These alterations were more severe in male livers. Minimum or nearly normal changes were observed in female liver slides. In addition, the histological assessment indicated that treatment with FLX during adolescence also increased the heart's weight and the wall thickness of the right and left ventricles (hypertrophy) in male and especially female animals.

CONCLUSION

Our findings may provide new insights into the cardiac and hepatic adverse effects of FLX.

Carvedilol attenuates inflammatory reactions of lipopolysaccharide-stimulated BV2 cells and modulates M1/M2 polarization of microglia via regulating NLRP3, Notch, and PPAR-γ signaling pathways

Microglial cells coordinate immune responses in the central nervous system. Carvedilol (CVL) is a non-selective β-blocker with anti-inflammatory and anti-oxidant effects. This study aims to investigate the anti-inflammatory effects and the underlying mechanisms of CVL on lipopolysaccharide (LPS)-induced inflammation in microglial BV2 cells. BV2 cells were stimulated with LPS, and the protective effects of CVL were investigated via measurement of cell viability, reactive oxygen species (ROS), and interleukin (IL)-1β liberation. The protein levels of some inflammatory cascade, Notch, and peroxisome proliferator-activated receptor (PPAR)-γ pathways and relative markers of M1/M2 microglial phenotypes were assessed. Neuroblastoma SH-SY5Y cells were cultured with a BV2-conditioned medium (CM), and the capacity of CVL to protect cell viability was evaluated. CVL displayed a protective effect against LPS stress through reducing ROS and down-regulating of nuclear factor kappa B (NF-κB) p65, NLR family pyrin domain containing-3 (NLRP3), and IL-1β proteins. LPS treatment significantly increased the levels of the M1 microglial marker inducible nitric oxide synthase (iNOS) and M1-associated cleaved-NOTCH1 and hairy and enhancer of split-1 (HES1) proteins. Conversely, LPS treatment reduced the levels of the M2 marker arginase-1 (Arg-1) and PPAR-γ proteins. CVL pre-treatment reduced the protein levels of iNOS, cleaved-NOTCH1, and HES1, while increased Arg-1 and PPAR-γ. CM of CVL-primed BV2 cells significantly improved SH-SY5Y cell viability as compared with the LPS-induced cells. CVL suppressed ROS production and alleviated the expression of inflammatory markers in LPS-stimulated BV2 cells. Our results demonstrated that targeting Notch and PPAR-γ pathways as well as directing BV2 cell polarization toward the M2 phenotype may provide a therapeutic strategy to suppress neuroinflammation by CVL.

Anti-angiogenic effects of aqueous extract from Agrostemma githago L. seed in human umbilical vein endothelial cells via regulating Notch/VEGF, MMP2/9, ANG2, and VEGFR2

Abnormal angiogenesis contributes to the pathogenesis of various diseases. The medicinal usage of Agrostemma githago L. seed (A. githago herein) has been stated in traditional medicine. This study aims to investigate the anti-angiogenic potential of aqueous extract of A. githago. In order to test the effect of A. githago extract, its impact on HUVECs, T98G, and HGF2PI2 cells was assessed by looking at cellular viability, changes in the distribution of cells in different phases of the cell cycle, induction of oxidative stress, and apoptosis. In addition, the release of VEGF, ANG2, and MMP2/9 factors, along with the expressions of the critical Notch signaling pathway players and VEGF receptors (VEGFR), was measured. Furthermore, a γ-secretase inhibitor (LY411575) was applied to determine whether Notch inhibition restores A. githago effects. As a further characterization, total phenolic and flavonoid contents of A. githago were estimated, and five triterpene saponin compounds were identified using LC-ESI-MS. In response to A. githago extract, a reduction in total cell viability, along with the induction of ROS and apoptosis, was detected. Exposure to the A. githago extract could modulate the release of VEGF and ANG2 from T98G and HUVECs, respectively. In addition, A. githago reduced the release of MMP2/9. Furthermore, Notch1, DLL4, and HEY2 transcripts and protein expressions were up-regulated, while VEGFR2 was down-regulated in treated HUVEC cells. Treatment with the A. githago extract resulted in a dose-dependent inhibition of AKT phosphorylation. Inhibition of Notch signaling retrieved the viability loss, reduced intracellular ROS, and alleviated the impaired tube formation in A. githago-treated HUVECs. Overall, these data underscore the anti-angiogenic potential of A. githago via inducing apoptosis, modifying the expression levels of VEGF/VEGFR2, and impacting the release of MMP2/9 and ANG2, effects that are most probably modulated through the Notch/VEGF signaling axis.

Transdifferentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Dopaminergic Neurons in a Three-Dimensional Culture

Introduction

The induction of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) toward dopaminergic neurons is a major challenge in tissue engineering and experimental and clinical treatments of various neurodegenerative diseases, including Parkinson disease. This study aims to differentiate HUC-MSCs into dopaminergic neuron-like cells.

Methods

Following the isolation and characterization of HUC-MSCs, they were transferred to Matrigel-coated plates and incubated with a cocktail of dopaminergic neuronal differentiation factors. The capacity of differentiation into dopaminergic neuron-like cells in 2-dimensional culture and on Matrigel was assessed by real-time polymerase chain reaction, immunocytochemistry, and high-performance liquid chromatography.

Results

Our results showed that dopaminergic neuronal markers' transcript and protein levels were significantly increased on the Matrigel differentiated cells compared to 2D culture plates.

Conclusion

Overall, the results of this study suggest that HUC-MSCs can successfully differentiate toward dopaminergic neuron-like cells on Matrigel, having great potential for the treatment of dopaminergic neuron-related diseases.

Carvedilol attenuates brain damage in mice with hepatic encephalopathy

Brain injury is the most common and serious consequence of hepatic encephalopathy (HE), and its pathophysiology is poorly understood. Excessive inflammatory, oxidative and apoptotic responses are the major mechanisms involved in the progression of brain injury induced by HE. Carvedilol is an adrenergic receptor antagonist with pronouncedantioxidant and anti-inflammatory activity. The present study aimed to investigatethe effects and underlying mechanisms of carvedilol on HE-induced brain damage in mice. Experimental model of HE was induced by the injection of thioacetamide (200 mg/kg) for two consecutive days and then mice were treated with carvedilol (10 or 20 mg/kg/day, orally) for 3 days in treatment groups. After the behavioral test, animals were sacrificed and the brain tissues were collected for biochemical, real time PCR and immunohistochemical analysis. The results showed that carvedilol improved locomotor impairment and reduced mortality rate in mice with HE. Carvedilol treatment decreased the brain levels of oxidative stress markers and induced Nrf2/HO-1 pathway. Carvedilol inhibited the activity of nuclear factor kappa B (NF-κB) and the expression of pro-inflammatory cytokines TNF-α, IL1β and IL-6 in the brain tissues. Treatment of mice with carvedilol caused a significant reduction in the brain levels of iNOS/NO, myeloperoxidase (MPO), cyclooxygenase (COX)-2 and chemokine MCP-1 as proinflammatory mediators in HE. Moreover, the ratio of Bcl2/Bax was increased and apoptotic cell death was decreased in the brain of mice treated with carvedilol. In conclusion, carvedilol exerted protective effect against HE-induced brain injury through increasing antioxidant defense mechanisms and inhibitionof inflammatory and apoptotic pathways.

Methylsulfonylmethane protects against ethanol-induced brain injury in mice through the inhibition of oxidative stress, proinflammatory mediators and apoptotic cell death

Excessive ethanol consumption causes brain injury through oxidative stress, inflammation and apoptotic cell death. Methylsulfonylmethane (MSM) is a natural compound that has therapeutic effects on oxidative and inflammatory disorders. The aim of this study was to investigate the protective effect and underlying mechanisms of MSM on ethanol-induced brain injury in an experimental model. Male C57BL/6 mice were exposed to binge ethanol (5 g/kg/day, orally) and treated with MSM (200 and 400 mg/kg/day) concomitantly for 12 days. At the end of the experiment brain tissues were removed for histological and biochemical analysis. The results showed that MSM reduced ethanol-mediated oxidative stress by decreasing the levels of malondialdehyde (MDA) and carbonyl protein. The Nrf2/HO-1 pathway and the levels of cytoprotective antioxidants superoxide dismutase (SOD), catalase and glutathione (GSH) were increased by MSM in the brain tissue. MSM treatment reduced the ethanol-induced inflammatory factors including myeloperoxidase (MPO), iNOS/NO, cyclooxygenase (COX)-2, nuclear factor kappa B (NF-κB), NLRP3 inflammasome and proinflammatory cytokines including TNF-α, IL-1β, IL-6 and MCP-1. MSM also decreased the levels of pro-apoptotic caspase-3 and TUNEL positive cells while increased the level of anti-apoptotic Bcl-2 in the brain tissue. Our findings demonstrated that MSM protects against ethanol-induced brain injury by improving anti-oxidant defense mechanism and reducing ethanol-mediated inflammation and apoptosis. Therefore, MSM may be a potential protective approach for brain damage caused by high levels of alcohol.

Postnatal depletion of serotonin affects the morphology of neurons and the function of the hippocampus in male rats

Serotonin (5-HT) is an essential neurotransmitter for the refined organization of the cerebral cortex. Studies have suggested that altered serotonin signaling contributes to cognitive impairment and psychiatric disorders. However, the exact role of this neurotransmitter on the development of hippocampal neurons is not recognized. Here we aimed to examine the effects of the para- chlorophenylalanine (PCPA; 100mg/kg/daily, s.c during the postnatal days 10-20), a reversible inhibitor of 5-HT synthesis, on the serotonin level of the hippocampal and prefrontal cortex. We also focused on the morphology of the neurons in the hippocampus and spatial learning and memory. Our results indicated that the administration of PCPA led to a decrease in serotonin levels in the hippocampus and prefrontal cortex. Postnatal serotonin depletion also induced subtle alterations in the neuronal populations of the hippocampus and impaired spatial memory in the adulthood period of life. We found that critical developmental periods of serotonin depletion caused degeneration and swelling of neurons as well as significant neuronal loss in the hippocampal CA1, CA3, and dentate gyrus (DG) areas. Thus, serotonin, a strikingly important neurotransmitter, can affect neuronal morphology, development, and hippocampal-dependent memory.

Antibacterial effect of TiO2 modified with poly-amidoamine dendrimer - G3 on S. aureus and E. coli in aqueous solutions

This study investigated bacterial removal using TiO₂ nanoparticles (NPs) modified with poly-amidoamine dendrimer macromolecule (PAMAM, G3). The PAMAM G3/TiO₂ (nanohybrid) was used to specify antibacterial properties via broth microdilution (MBC-Minimum Bactericidal Concentration and MIC-Minimum Inhibitory Concentration-determination), paper disc diffusion, and surface plate count methods. The nanohybrid was characterized via the different techniques. The effects of different factors including initial bacteria count, run time, solution pH, and the nanohybrid concentration were studied. The nanohybrid cytotoxicity was studied on AGS and MKN45 cells line by MTT assay. It was revealed that the nanohybrid was effective in intercepting both bacterial strains growth. The MIC value for S. aureus and E. coli were determined to be 4 and 2 μg/mL, respectively. The MBC value for both strains were calculated to be 32 μg/mL. The results showed removal efficiency of 100% for S. aureus and E. coli bacteria in optimum situation. The decrease in cell viability in the dosage of 32 μg/mL after 72 h treatment for AGS and MKN45 cells line were shown to be 6.2 and 4.6%, respectively. The nanohybrid was able to decrease the S. aureus and E. coli count in solution, which meets the drinking water criterions aligned with WHO guidelines.

Differentiation of human dental pulp stem cells into functional motor neuron: In vitro and ex vivo study

There are several therapeutic options for spinal cord injury (SCI), among these strategies stem cell therapy is a potential treatment. The stem cells based therapies have been investigating in acute phase of clinical trials for promoting spinal repair in humans through replacement of functional neuronal and glial cells. The aim of this study was to evaluate the differentiation of Human Dental Pulp Stem Cells (hDPSCs) into functional motor neuron like cells (MNLCs) and promote neuroregeneration by stimulating local neurogenesis in the adult spinal cord slice culture. The immunocytochemistry analysis demonstrated that hDPSCs were positive for mesenchymal stem cell markers (CD73, CD90 and CD105) and negative for the hematopoietic markers (CD34 and CD45). hDPSCs were induced to neurospheres (via implementing B27, EGF, and bFGF) and then neural stem cells (NSC). The NSC differentiated into MNLCs in two steps: first by Shh and RA and ; then with GDNF and BDNF administration. The NS and the NSC were assessed for Oct4, nestin, Nanog, Sox2 expression while the MNLCs were evaluated by ISLET1, Olig2, and HB9 genes. Our results showed that hDPSC can be differentiated into motor neuron phenotype with expression of the motor neuron genes. The functionality of MNLCs was demonstrated by FM1-43, intracellular calcium ion shift and co- culture with C2C12. We co-cultivated hDPSCs with adult rat spinal slices in vitro. Immunostaining and hoechst assay showed that hDPSCs were able to migrate, proliferate and integrate in both the anterolateral zone and the edges of the spinal slices.

Role of cerebrospinal fluid in differentiation of human dental pulp stem cells into neuron-like cells

Human dental pulp stem cells (hDPSCs) could be differentiated into neuron like-cells under particular microenvironments. It has been reported that a wide range of factors, presented in cerebrospinal fluid (CSF), playing part in neuronal differentiation during embryonic stages, we herein introduce a novel culture media complex to differentiate hDPSCs into neuron-like cells. The hDPSCs were initially isolated and characterized. The CSF was prepared from the Cisterna magna of 19-day-old Wistar rat embryos, embryonic cerebrospinal fluid (E-CSF). The hDPSCs were treated by 5% E-CSF for 2 days, then neurospheres were cultured in DMEM/F12 supplemented with 10^-6 μm retinoic acid (RA), glial-derived neurotrophic factor and brain-derived neurotrophic factor for 6 days. The cells which were cultured in basic culture medium were considered as control group. Morphology of differentiated cells as well as process elongation were examined by an inverted microscope. In addition, the neural differentiation markers (Nestin and MAP2) were studied employing immunocytochemistry. Neuronal-like processes appeared 8 days after treatment. Neural progenitor marker (Nestin) and a mature neural marker (MAP2) were expressed in treated group. Moreover Nissl bodies were found in the cytoplasm of treated group. Taking these together, we have designed a simple protocol for generating neuron-like cells using CSF from the hDPSCs, applicable for cell therapy in several neurodegenerative disorders including Alzheimer's disease.

2,4-D causes oxidative stress induction and apoptosis in human dental pulp stem cells (hDPSCs)

2,4-Dicholorophenoxy acetic acid (2,4-D) is a worldwide used hormone herbicide. Human dental pulp stem cells (hDPSCs) as a potential source of mesenchymal stem cells provide a confident model system for the assessments of chemicals in vitro. The main objective of this study was to examine the biological effects and damages attributed to 2,4-D on hDPSCs. hDPSCs were isolated from third molar pulp tissues and their mesenchymal identity were evaluated. Then, hDPSCs were treated with increasing concentrations of 2,4-D (0.1 μM-10 mM). Cell viability assay and cumulative cell counting were carried out to address 2,4-D effects on biological parameters of hDPSCs. Cell cycle distribution, ROS level and ALP activity were measured before and after treatment. AO/EB staining and caspase 3/7 activity were investigated to detect the possible mechanisms of cell death. Flow-cytometric immunophenotyping and differentiation data confirmed the mesenchymal identity of cultivated hDPSCs. 2,4-D treatment caused a hormetic response in the viability and growth rate of hDPSCs. G0/G1 cell cycle arrest, enhanced ROS level, and reduced ALP activity were detected in hDPSCs treated with EC50 dose of 2,4-D. AO/EB staining showed a higher percentage of alive cells in lower concentrations of the herbicide. The increment in 2,4-D dose and the number of early and late apoptotic cells were increased. DAPI staining and caspase 3/7 assay validated the induction of apoptosis. 2,4-D concentrations up to 100 μM did not affect hDPSCs viability and proliferation. The intense cellular oxidative stress and apoptosis were observed at higher concentration.

Pharmacological Notch pathway inhibition leads to cell cycle arrest and stimulates ascl1 and neurogenin2 genes expression in dental pulp stem cells-derived neurospheres

OBJECTIVE

Human dental pulp-derived stem cells (hDPSCs) are becoming an attractive source for cell-based neurorestorative therapies. As such, it is important to understand the molecular mechanisms that regulate the differentiation of hDPSCs toward the neuronal fate. Notch signaling plays key roles in neural stem/progenitor cells (NS/PCs) maintenance and prevention of their differentiation. The aim of this study was to address the effects of Notch signaling inhibition on neurosphere formation of hDPSCs and neuronal differentiation of hDPSCs-neurospheres.

RESULTS

hDPSCs were isolated from third molar teeth. The cultivated hDPSCs highly expressed CD90 and CD44 and minimally presented CD34 and CD45 surface markers. The osteo/adipogenic differentiation of hDPSCs was documented. hDPSCs were cultured in neural induction medium and N-[N-(3,5-difluorophenacetyl-L-alanyl)]-Sphenylglycine t-butyl ester (DAPT) was applied to impede Notch signaling during transformation into spheres or on the formed neurospheres. Our results showed that the size and number of neurospheres decreased and the expression profile of nestin, sox1 and pax6 genes reduced provided DAPT. Treatment of the formed neurospheres with DAPT resulted in the cleaved Notch1 reduction, G0/G1 arrest and a decline in L-lactate production. DAPT significantly reduced hes1 and hey1 genes, while ascl1 and neurogenin2 expressions augmented. The number of MAP2 positive cells improved in the DAPT-treated group.

CONCLUSIONS

Our findings demonstrated the Notch activity in hDPSCs-neurospheres. DAPT treatment positively regulated proneural genes expression and increased neuronal-like differentiation.

Combination treatment of all-trans retinoic acid (ATRA) and γ-secretase inhibitor (DAPT) cause growth inhibition and apoptosis induction in the human gastric cancer cell line

Current medication for gastric cancer patients has a low success rate with resistance and side effects. According to recent studies, γ-secretase inhibitors is used as therapeutic drugs in cancer. Moreover, all-trans retinoic acid (ATRA) is a natural compound proposed for the treatment/chemo-prevention of cancers. The aim of this study was to explore the effects of ATRA in combination with N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester (DAPT) as γ-secretase inhibitor on viability and apoptosis of the AGS and MKN-45 derived from human gastric cancer. AGS and MKN-45 gastric cancer cell lines were treated with different concentrations of ATRA or DAPT alone or ATRA plus DAPT. The viability, death detection and apoptosis of cells was examined by MTT assay and Ethidium bromide/acridine orange staining. The distribution of cells in different phases of cell cycle was also evaluated through flow cytometry analyses. In addition, caspase 3/7 activity and the expression of caspase-3 and bcl-2 were examined. DAPT and ATRA alone decreased gastric cancer cells viability in a concentration dependent manner. The combination of DAPT and ATRA exhibited significant synergistic inhibitory effects. The greater percentage of cells were accumulated in G0/G1 phase of cell cycle in combination treatment. The combination of DAPT and ATRA effectively increased the proportion of apoptotic cells and the level of caspase 3/7 activities compared to single treatment. Moreover, augmented caspase-3 up-regulation and bcl-2 down-regulation were found following combined application of DAPT and ATRA. The combination of DAPT and ATRA led to more reduction in viability and apoptosis in respect to DAPT or ATRA alone in the investigated cell lines.

An Overview of Neural Differentiation Potential of Human Adipose Derived Stem Cells

There is wide interest in application of adult stem cells due to easy to obtain with a minimal patient discomfort, capable of producing cell numbers in large quantities and their immunocompatible properties without restriction by ethical concerns. Among these stem cells, multipotent mesenchymal stem cells (MSCs) from human adipose tissue are considered as an ideal source for various regenerative medicine. In spite of mesodermal origin of human adipose-derived stem cells (hADSCs), these cells have differentiation potential toward mesodermal and non-mesodermal lineages. Up to now, several studies have shown that hADSCs can undergo transdifferentiation and produce cells outside of their lineage, especially into neural cells when they are transferred to a specific cell environment. The purpose of this literature review is to provide an overview of the existing state of knowledge of the differentiation potential of hADSCs, specifically their ability to give rise to neuronal cells. The following review discusses different protocols considered for differentiation of hADSCs to neural cells, the neural markers that are used in each procedure and possible mechanisms that are involved in this differentiation.

Human platelet lysate versus minoxidil stimulates hair growth by activating anagen promoting signaling pathways

Minoxidil and human platelet lysate (HPL) are commonly used to treat patients with hair loss. However, the roles of HPL versus minoxidil in hair follicle biology largely remain unknown. Here, we hypothesized that bulge and dermal papilla (DP) cells may express specific genes, including Kras, Erk, Akt, Shh and β-catenin after exposure to minoxidil or HPL. The mouse hair follicles were isolated on day 10 after depilation and bulge or DP regions were dissected. The bulge and DP cells were cultured for 14days in DMEM/F12 medium. Then, the cells were treated with 100μM minoxidil and 10% HPL for 10 days. Nuclear morphology was identified using DAPi staining. Reverse transcriptase and real-time polymerase chain reaction (PCR) analysis were also performed to examine the expression of Kras, Erk, Akt, Shh and β-catenin mRNA levels in the treated bulge and DP regions after organ culture. Here, we found that minoxidil influences bulge and DP cell survival (P<0.05). Apoptosis in DP cells was also meaningfully decreased by HPL treatment (P=0.014). In addition, Kras, Akt, Erk, Shh and β-catenin mRNA levels were changed in response to minoxidil treatment in both bulge and DP cells. HPL mediated Erk upregulation in both bulge and DP cells (P<0.05), but Kras and Akt mRNA levels were not considerably different in the HPL-treated cells. β-catenin mRNA level was also significantly increased in the bulge region by HPL. We also found that Shh mRNA level was considerably higher in HPL-treated bulge cells than in minoxidil-treated bulge cells. In contrast, the expression of β-cateinin and Shh in the DP cells was not meaningfully increased after treatment with HPL. Our results suggest that minoxidil and HPL can promote hair growth by activating the main anagen inducing signaling pathways.

Efficacy of optimized in vitro predegeneration period on the cell count and purity of canine Schwann cell cultures

OBJECTIVES

Predegeneration is a standard technique to obtain mitotically activated and enriched cultures of Schwann cells (SCs). This study, for the first time, evaluated the impact of various duration of predegeneration on cell yield and enrichment of SCs from dog peripheral nerve.

MATERIALS AND METHODS

Dog sural nerves were subjected to 5, 10, 15 day-long in vitro predegeneration. The total cell yield and the purity of SCs were evaluated in each group on the first and seventh day after plating.

RESULTS

The maximum and minimum numbers of cells were counted in 15 day-long predegene-ration and control groups which underwent no predegeneration. The 10 day-long in vitro predegeneration group with 80±0.5% SCs enrichment had the best purity after plating day and could maintain its purity with elapsing on cultures.

CONCLUSION

10 day-long predegeneration results in the higher cell number and the better and prolonged purity of SCs in culture.

An efficient system for selection and culture of Schwann cells from adult rat peripheral nerves

Schwann cells (SCs), the supporting cells of the peripheral nerves, are indispensable for regenerating the peripheral and central nervous system. Copious preparation of these cells in a well-defined manner is to be a privileged position. SCs cultivation is overwhelmed by contaminating fibroblasts which are often outgrowing as the predominant cell type in an in vitro culture. This study introduces a technically simple and efficient procedure for SCs isolation and enrichment based on implementing recombinant and defined supplements. Collected adult rat sciatic nerves were cultured for 10 days as in vitro predegeneration. After dissociation and plating, the medium changed to knockout serum replacement supplemented DMDM/F12 medium containing various growth factors. The whole procedure took 3 weeks and SCs purity was then evaluated through implementing specific cytoplasmic and membranous markers. The viability of enriched SCs were evaluated by MTT assay. Within 10 days, over 99 % homogenous SCs were achieved and confirmed through immunofluorescence staining and flow-cytometry for P75(NTR) and S100 markers, respectively. MTT data revealed that the viability and metabolic activities of purified SCs were increased in expansion medium. This study provides a technically easy and efficient method with the benefits of not utilizing bovine serum or other animal products for SCs isolation and enrichment.

All trans retinoic acid modulates peripheral nerve fibroblasts viability and apoptosis

OBJECTIVE

Following peripheral nerve injury, residing fibroblasts start to proliferate and accumulate at the injury site and may participate in neuroma tissue evolution. Retinoic acid has been shown to regulate many cellular processes and to display anti-proliferative and anti-fibrotic properties. The aim of this study was to investigate the impact of all trans retinoic acid (ATRA) on rat peripheral nerve fibroblasts.

MATERIALS AND METHODS

Peripheral nerve fibroblasts and C166 cells were treated with increasing doses of ATRA (0.05 nM to 1 μM). The viability of cells was determined with 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, the number of peripheral nerve fibroblasts was counted after two days of ATRA treatment and alternatively up to the end of next week. Acridine orange/ethidium bromide double staining was implemented to morphologically visualize the possible mechanism of cell death. For apoptosis, caspase 3/7 activity was measured using Caspase-Glo 3/7 assay kit.

RESULTS

MTT assay revealed that 0.05-1 nM of ATRA reduces fibroblasts viabilities. Then, almost a plateau state was observed from 1 nM to 1 μM of ATRA exposure. Additionally, a deceleration in peripheral nerve fibroblasts growth was confirmed via cell counting. Quantification of acridine orange/ethidium bromide staining displayed highly increased number of early apoptotic cells following ATRA administration. Amplified activation of caspase 3/7 was in favor of apoptosis in ATRA treated peripheral nerve fibroblasts.

CONCLUSION

The data from the present study demonstrate that ATRA could interfere in peripheral nerve fibroblasts viabilities and induce apoptosis. Although more investigations are needed to be implemented, our in vitro results indicate that retinoic acid can probably help the regeneration of injured axon via reducing of fibroblasts growth.

Cotransplantation of Human Embryonic Stem Cell-Derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery

Cotransplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when cocultured with SCs in vitro and cotransplanted in a rat acute model of contused SCI. Cocultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was observed in all engrafted groups (NPs, SCs, NPs + SCs) relative to the vehicle and control groups. We also observed that animals receiving cotransplants established a better state as assessed with the BBB functional test. Immunohistofluorescence evaluation 5 weeks after transplantation showed invigorated neuronal differentiation and limited proliferation in the cotransplanted group when compared to the individual hESC-NP-grafted group. These findings have demonstrated that the cotransplantation of SCs with hESC-NPs could offer a synergistic effect, promoting neuronal differentiation and functional recovery.

Transplantation of undifferentiated and induced human exfoliated deciduous teeth-derived stem cells promote functional recovery of rat spinal cord contusion injury model

Regarding both the neural crest origin and neuronal potential of stem cells from human exfoliated deciduous teeth (SHED), here, we assessed their potential in addition to neural induced SHED (iSHED) for functional recovery when transplanted in a rat model for acute contused spinal cord injury (SCI). Following transplantation, a significant functional recovery was observed in both groups relative to the vehicle and control groups as determined by the open field locomotor functional test. We also observed that animals that received iSHED were in a better state as compared with the SHED group. Immunohistofluorescence evaluation 5 weeks after transplantation showed neuronal and glial differentiation and limited proliferation in both groups. However, myelin basic protein and chondroitin sulfate proteoglycan NG2-oligodendrocyte markers-were increased and glial fibrillary acidic protein-astrocyte marker-was decreased in the iSHED group in comparison with the SHED group. These findings have demonstrated that transplantation of SHED or its derivatives could be a suitable candidate for the treatment of SCI as well as other neuronal degenerative diseases.

Novel method to obtain highly enriched cultures of adult rat Schwann cells

Schwann cells (SCs) can be used to repair both the peripheral and central nervous systems. Therefore, establishment of a procedure to obtain activated, highly proliferative SCs, in an appropriate time for clinical applications, is a prerequisite. Purification is complicated by contamination with fibroblasts which often become the predominant cell type in an in vitro SC culture. This study describes a novel and efficient method to enrich SCs by utilizing the differential detachment properties of the two cell types. In culture, cells were treated with two different media and the chelator, EGTA, which detached SCs faster than fibroblasts and allowed for easy isolation of SCs. Within seven days, high yields of SCs with a purity of greater than 99% were achieved. This was confirmed by immunostaining characterization and flow-cytometric analyses using an antibody against the p75 low affinity nerve growth factor receptor (p75LNGFR). The entire procedure was completed in approximately 21 days. This method has the advantage of being technically easier, faster, and more efficient than other previously described methods. An SC culture that was about 99% homogenous was achieved.