Original Article Time Course of Axotomy-induced Changes in Synaptophysin Pattern and Synaptic Reaction of Spinal Motoneurons in Adult Rat

ABSTRACT Background and Objective: Evaluation of degenerative changes of motoneurons and thei

Self-organization of developing embryo using scale-invariant approach

<p>Abstract</p> <p>Background</p> <p>Self-organization is a fundamental feature of living organisms at all hierarchical levels from molecule to organ. It has also been documented in developing embryos.</p> <p>Methods</p> <p>In this study, a scale-invariant power law (SIPL) method has been used to study self-organization in developing embryos. The SIPL coefficient was calculated using a centro-axial skew symmetrical matrix (CSSM) generated by entering the components of the Cartesian coordinates; for each component, one CSSM was generated. A basic square matrix (BSM) was constructed and the determinant was calculated in order to estimate the SIPL coefficient. This was applied to developing <it>C. elegans </it>during early stages of embryogenesis. The power law property of the method was evaluated using the straight line and Koch curve and the results were consistent with fractal dimensions (fd). Diffusion-limited aggregation (DLA) was used to validate the SIPL method.</p> <p>Results and conclusion</p> <p>The fractal dimensions of both the straight line and Koch curve showed consistency with the SIPL coefficients, which indicated the power law behavior of the SIPL method. The results showed that the ABp sublineage had a higher SIPL coefficient than EMS, indicating that ABp is more organized than EMS. The fd determined using DLA was higher in ABp than in EMS and its value was consistent with type 1 cluster formation, while that in EMS was consistent with type 2.</p

The Effects of Pentoxifylline on Mouse Epididymal Sperm Parameters, Fertilization and Cleavage Rates after Short Time Preservation

Background: Pentoxifylline (PX) prevents cAMP breakdown by inhibiting the activity of the cAMP-phosphatase and presumably, stimulates sperm motion. Incubation with PX causes hyperactivation of sperm, an important step in achieving fertilization, and leads to changes in membranes associated with sperm capacitation. Objective: The purpose of this study was to examine the effects of pentoxifylline on sperm viability, motility and fertilization rate after mouse sperm preservation. Materials & Methods: Epididymal spermatozoa from adult NMRI mice were collected in T6 medium supplemented with 5% BSA and divided into four control and four experimental groups. The control groups included: (1) Fresh sperm sample (2) Preserved sperm sample at room temperature for 18 hours. (3) Preserved sperm sample at incubator 37°C for 18 hours. (4) Preserved sperm sample at 4°C for 18 hours. Experimental groups were the same groups after treatment with 3mmol/L PX. All the samples were assessed according to World Health Organization Criteria. Oocytes from superovulated NMRI female mice were inseminated in-vitro incubated sperm of all the control and experimental groups. After insemination and washing, the fertilization rate and cleavage rate were assessed by the presence of two pronucleus (2PN) and 2-cell stage embryos. To study the acrosomal reaction of control and treated spermatozoa transmission electron microscopy (TEM) technique was used. Results: The results showed that addition of 3mmol PX to preserved mouse spermatozoa at 4 ºC and 37 ºC could increase the motility rate significantly (P<0.05) and also it could enhance abnormal morphology rate. Significant increase of fertilization rate was seen after preservation of treated sperm at 4 ºC (P<0.05), but there was not seen significant difference regarding cleavage rate comparing treated and non-treated spermatozoa (P>0.05). Studies with electron microscopy showed that addition of PX to the preserved spermatozoa prevent early acrosomal reaction. Conclusion: The results of this study demonstrated that addition of pentoxifylline in mouse sperm samples after short time preservation can enhance the motility and fertilization rate, although it can enhance the abnormal morphology. It also can increase the number of intact sperm after preservation

The effects of cinnamaldehyde and eugenol on human adipose-derived mesenchymal stem cells viability, growth and differentiation: a cheminformatics and in vitro study

Objective: The aim of this study was to estimate the cheminformatics and qualitative structure-activity relationship (QSAR) of cinnamaldehyde and eugenol. The effects of cinnamaldehyde and eugenol on the viability, doubling time and adipogenic or osteogenic differentiations of human adipose-derived mesenchymal stem cells (hASCs) were also investigated.  Materials and Methods: QSAR and toxicity indices of cinnamaldehyde and eugenol were evaluated using cheminformatics tools including Toxtree and Toxicity Estimation Software Tool (T.E.S.T) and molinspiration server. Besides, their effects on the hASCs viability, doubling time and differentiation to adipogenic or osteogenic lineages were evaluated. Results: Cinnamaldehyde is predicted to be more lipophilic and less toxic than eugenol. Both phytochemicals may be developmental toxicants. They probably undergo hydroxylation and epoxidation reactions by cytochrome-P450. The 2.5 µM/ml cinnamaldehyde and 0.1 µg/ml eugenol did not influence hASCs viability following 72 hr of treatment. But higher concentrations of these phytochemicals insignificantly increased hASCs doubling time till 96 hr, except 1 µg/ml eugenol for which the increase was significant. Only low concentrations of both phytochemicals were tested for their effects on the hASCs differentiation. The 2.5 µM/ml cinnamaldehyde and 0.1 µg/ml eugenol enhanced the osteogenesis and decreased the adipogenesis of hASCs meaningfully. Conclusion: According to the cheminformatics analysis and in vitro study, cinnamaldehyde and eugenol are biocompatible and low toxic for hASCs. Both phytochemicals may be suitable for regenerative medicine and tissue engineering when used at low concentrations, but maybe useful for neoplastic growth inhibition when used at high concentrations

Study of lead-induced neurotoxicity in cholinergic cells differentiated from bone marrow-derived mesenchymal stem cells

The developing brain is susceptible to the neurotoxic effects of lead. Exposure to lead has main effects on the cholinergic system and causes reduction of cholinergic neuron function during brain development. Disruption of the cholinergic system by chemicals, which play important roles during brain development, causes of neurodevelopmental toxicity. Differentiation of stem cells to neural cells is recently considered a promising tool for neurodevelopmental toxicity studies. This study evaluated the toxicity of lead acetate exposure during the differentiation of bone marrow-derived mesenchyme stem cells (bone marrow stem cells, BMSCs) to cholinergic neurons. Following institutional animal care review board approval, BMSCs were obtained from adult rats. The differentiating protocol included two stages that were pre-induction with beta-mercaptoethanol (BME) for 24 h and differentiation to cholinergic neurons with nerve growth factor (NGF) over 5 days. The cells were exposed to different lead acetate concentrations (0.1-100 mu m) during three stages, including undifferentiated, pre-induction, and neuronal differentiation stages; cell viability was measured by MTT assay. Lead exposure (0.01-100 mu g/ml) had no cytotoxic effect on BMSCs but could significantly reduce cell viability at 50 and 100 mu m concentrations during pre-induction and neuronal differentiation stages. MAP2 and choline acetyltransferase (ChAT) protein expression were investigated by immunocytochemistry. Although cells treated with 100 mu m lead concentration expressed MAP2 protein in the differentiation stages, they had no neuronal cell morphology. The ChAT expression was negative in cells treated with lead. The present study showed that differentiated neuronal BMSCs are sensitive to lead toxicity during differentiation, and it is suggested that these cells be used to study neurodevelopmental toxicity

Relationship between the clinical scoring and demyelination in central nervous system with total antioxidant capacity of plasma during experimental autoimmune encephalomyelitis development in mice

Experimental autoimmune encephalomyelitis (EAE) was induced in a mouse model (C57/BL6) to investigate the antioxidant status of animals at various clinical stages of the disease. For this purpose, blood, brain and spinal cord samples from EAE mice were collected and examined at different scores following post-immunization with myelin oligodendrocyte glycoprotein (MOG). The clinical sign of mobility of animals on different days was associated with gradual increase in lipid peroxidation products (malondialdehyde, i.e. NIDA) in brain and spinal cord. Changes in lipid peroxidation during EAE progression was inversely related to superoxide dismutase (SOD) activity in erythrocyte preparation. However, suppression of catalase in erythrocytes, tissue glutathione (GSH) and plasma total antioxidant capacity (FRAP assay) were the early events in EAE, occurred during scores 1 and 2. Biochemical alterations were corroborated with histopathological observations showing demyelination and inflammatory foci in central nervous system (CNS) of animals suffering from partial hind limb paralysis (score 3). These data suggest that generation of NIDA in CNS is a continuous process during EAE induction and suppression of antioxidant factors are early events of the disease, but crucial in increasing the vulnerability of CNS to demyelinating lesions

Human wild-type superoxide dismutase 1 gene delivery to rat bone marrow stromal cells: its importance and potential future trends

Objective(s): Human superoxide dismutase 1 (SOD1) is the cytosolic form of this enzyme it detoxifies superoxide anions and attenuates their toxicities and concomitant detrimental effects on the cells. It is believed that the amount of these enzymes present in the oxidative stress-induced diseases is crucial for preventing disease progression. Transfection of rat bone marrow stromal cells (BMSCs) by a constructed vector carrying the human wild-type SOD1 gene, a non-viral gene transfer method, was the main aim of this study. Materials and Methods: For this purpose, the rat BMSCs were transfected with the vector using Turbofect reagent and then stabilized. Western-blot and real-time PCR were also used for evaluation of SOD1 expression. Results: Data analysis from RT-PCR and Western-blot techniques revealed that the stable transfected cells could secrete human wild-type SOD1 in the supernatant. Also, the total activity of SOD1 was about 0.5±0.09 U/ml and 0.005±0.002 U/ml in the supernatants of the transfected and not-transfected of rat BMSCs, respectively. Conclusion: This study showed that expansion of the stable transfected rat BMSCs by a constructed vector carrying the human wild-type SOD1 gene is capable of secreting the active SOD1 enzyme under ex-vivo conditions.  The recommendation of this study is that the same experiment would be applicable for expression of the other form of this enzyme, SOD3, as well. More valuable information could probably be provided about the variety of the diseases caused by superoxide anions toxicities by intervention and application of the non-viral method for expressions of SOD1 and SOD3 enzymes

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