Neural stem cells neuroprotection by simvastatin via autophagy induction and apoptosis inhibition.

OBJECTIVE: This study was conducted to investigate the effects of Simvastatin (SIM), a member of statin family, on the cellular antioxidant system, autophagy and apoptosis in NSCs exposed to hydrogen peroxide. BACKGROUND: Reduction in cellular oxidative stress increases the survival of neural stem cells (NSCs) after transplantation into the damaged area of the affected central nervous system. MATERIAL AND METHODS: NSCs derived from bone marrow stromal cells (BMSCs) were exposed to H2O2 (100 µM) for 48 hours after pretreatment with SIM (2 µM). Next, the expressions of the master antioxidant transcription factor, Nrf2/nuclear factor erythroid 2 (NFE2)-related factor 2, autophagy-related proteins (microtubule-associated proteins 1A/1B light chain 3B known as LC3I and LC3II and also p62/Sequestosome), and apoptosis (Bcl-2/ B-cell lymphoma 2 and Bax/BCL2 associated X protein) were analyzed. RESULTS: SIM caused Nrf2 over-activation (more localizations in the cellular nucleus), reduction in reactive oxygen species (ROS), induction of autophagy (decrease in p62 expression and increase in LC3II/LC3I ratio) and inhibition of apoptosis (decrease in Bax protein and increase in Bcl-2) in NSCs exposed to H2O2-induced oxidative stress, thereby prolonging the cell viability within 48 hours at low concentration (2 µM). CONCLUSION: SIM protects NSCs against H2O2-induced apoptosis in a pleiotropic signaling manner (Fig. 7, Ref. 35).

Lithium prevents cell apoptosis through autophagy induction.

OBJECTIVE: Bone marrow stromal stem cells (BMSCs) are widely used as an available source for cell therapy, tissue engineering, and cellular differentiation-based techniques. Therefore, it is necessary to apply a simple method through which BMSCs can be protected from cell apoptosis under tough conditions of cell differentiation. Lithium treatment is one of the simple methods in this regard. METHODS: The isolated BMSCs were divided into three groups: (a) control, (b) serum deprivation and (c) LiCl. Cell proliferation and apoptosis and autophagy markers in the presence and absence of LiCl were evaluated. RESULTS: LiCl has shown to increase survival rate of BMSCs under serum deprivation conditions through autophagy induction (reduced P62 and increased LC3II) and apoptosis inhibition (expression of XIAP), so that the cell survival rate, after 12 hours, was 29 %, 59 %, 83 %, 74 %, 49 % for the groups, which received 0, 1, 5, 10, 20 millimolar of LiCl, respectively, as compared to the control group. CONCLUSION: LiCl leads to decreased apoptosis and increased survival rate through autophagy induction under serum deprivation conditions (Ref. 5, Ref. 37).

Effects of microwaves (950 MHZ mobile phone) on morphometric and apoptotic changes of rabbit epididymis.

The effect of mobile phone radiation on human reproduction system is still a matter of debate. In this study, 18 male rabbits were randomly divided into two experimental groups and one control group. Experimental groups received simulated microwaves with the frequency of 950 MHz and the output power of 3 and 6 watts for 2 weeks, 2 h a day. After a week of rest, the microscopic slides from the quada of the excised epididymis were prepared. Then, the diameter of epididymis, the height of epithelium and the number of apoptotic cells in epithelium in study groups were determined. The data were compared using spss software and one-way anova test. The epithelial height and diameter of the epididymis in 3 watt and 6 watt groups had a significant decrease compared to the control group (P < 0.001), while the testosterone level only in 6 watt group was significantly decreased compared to control group. The rate of apoptosis in the epithelial cells of the epididymis had a significant increase only in 6 watt group compared to the control group (P < 0.001). This study showed that the microwaves with the frequency of 950 MHz can have negative impacts on morphometric and apoptotic changes of rabbit epididymis.

Liver and breast feather mercury in piscivorous birds of the Caspian Sea: monitoring changes.

Mercury in the liver and breast feathers of the Common Cormorant, and in three species of Grebes from the southern coast of the Caspian Sea, were determined. The Common Cormorant had significantly more mercury in its tissues (liver: 8.5 ± 1.5; feather 8 ± 1 mg/kg dry weight) than Grebes (Great Crested Grebe: 3 ± 0.5, 8 ± 1.5; Black-necked Grebe: 3 ± 0.5, 5.5 ± 1; Little Grebe 2.5 ± 0.5, 4 ± 0.5). Unlike Common Cormorants, Grebes had less mercury in the liver than in breast feathers. Mercury in the Common Cormorant was not different between 2002 and 2008 collections. The mercury threshold for adverse effects is currently 5 ppm, which was exceeded by all but Little Grebes in this study.

Cerebellar Purkinje cells fire paroxysmal depolarization shift (PDS)-like events in response to epileptogenic drugs.

OBJECTIVE: Cerebellar Purkinje cells (PCs) fire burst of Na(+) spikes riding on a Ca(2+) spike which basically involves the same ionic channels and currents establishing the paroxysmal depolarization shift (PDS) discharges. METHODS: Intracellular recordings were taken from somata of PCs to explore effects of the epileptogenic drugs of pentylenetetrazol (PTZ), bicuculline methiodide (BCC) and 4-aminopyridine (4-AP) on the firing behavior of these cells. RESULTS: PCs showed spontaneous PDS-like events in presence of these drugs. Generally, PTZ and BCC-induced PDSs were similar in shape and properties but were remarkably different from 4-AP-induced PDSs. Blockade of glutamate transmission inhibited generation of PDSs by PTZ and BCC but it did not affect discharge of PDSs induced by 4-AP. Careful analysis of PDS discharges revealed that they have remarkable differences with normal and 4-AP-induced spontaneous activity. DISCUSSION: Data presented here indicate that PDS discharges in PCs are induced either by the imbalance between excitatory and inhibitory synaptic transmission or by the suppression of 4-AP-sensitive currents.

Biocompatibility evaluation of HDPE-UHMWPE reinforced ß-TCP nanocomposites using highly purified human osteoblast cells.

Biocompatibility of ß-TCP/HDPE-UHMWPE nanocomposite as a new bone substitute material was evaluated by using highly purified human osteoblast cells. Human osteoblast cells were isolated from bone tissue and characterized by immunofluorescence Staining before and after purification using magnetic bead system. Moreover, proliferation, alkaline phosphatase production, cell attachment, calcium deposition, gene expression, and morphology of osteoblast cells on ß-TCP/HDPE-UHMWPE nanocomposites were evaluated. The results have shown that the human osteoblast cells were successfully purified and were suitable for subsequent cell culturing process. The high proliferation rate of osteoblast cells on ß-TCP/HDPE-UHMWPE nanocomposite confirmed the great biocompatibility of the scaffold. Expression of bone-specific genes was taken place after the cells were incubated in composite extract solutions. Furthermore, osteoblast cells were able to mineralize the matrix next to composite samples. Scanning electron microscopy demonstrated that cells had normal morphology on the scaffold. Thus, these results indicated that the nanosized ß-TCP/HDPE-UHMWPE blend composites could be potential scaffold, which is used in bone tissue engineering.

Topographical and quantitative distribution of the projecting neurons to main divisions of the septal area.

OBJECTIVE: Septal area is a limbic structure that is involved in the regulation of several autonomic, learning-related and behavioral functions. Participation of this area in various physiologic functions is indicative of its extensive connections with different brain areas. It contains two major divisions: lateral septum (LS) and medial septum/diagonal band of Broca (MS/DBB). In the present work, we examined topographical distribution of projecting neurons to these divisions and quantitatively verified them. METHODS: Horseradish peroxidase (HRP) retrograde tract tracing was performed. RESULTS: Our results show that about two-thirds of projections to the septal area terminate in the LS. They mostly originate ipsilaterally from the septal area itself (8%), hippocampal formation (38%), non-specific thalamic nuclei (23%), lateral pre-optic area, lateral hypothalamus, perifornical area and mammillary complex in hypothalamus (20%), ventral tegmental area, raphe and tegmental nuclei, and also locus coeruleus in brainstem (10%). Most afferents to the MS come ipsilaterally from the septal area itself (18%), hippocampal formation (12%), lateral pre-optic area, lateral hypothalamus and mammillary complex in hypothalamus (42%), ventral tegmental area, raphe and tegmental nuclei, central gray matter and also locus coeruleus in brainstem (20%). Some afferents to the septal area originate contralaterally from the lateral hypothalamus, supramammillary area, raphe nuclei and locus coeruleus. DISCUSSION: Afferents from the interanterodorsal and mediodorsal thalamic nuclei, which increase the role of the septal area in arousal and awareness, are reported for the first time. Projecting cells to the MS support the learning-related function of this area. Projecting cells to the LS that are more scattered throughout the brain indicate its involvement in more diverse functions.

Dual effects of aliphatic carboxylic acids on cresolase and catecholase reactions of mushroom tyrosinase.

Catecholase and cresolase activities of mushroom tyrosinase (MT) were studied in presence of some n-alkyl carboxylic acid derivatives. Catecholase activity of MT achieved its optimal activity in presence of 1.0, 1.25, 2.0, 2.2 and 3.2 mM of pyruvic acid, acrylic acid, propanoic acid, 2-oxo-butanoic acid, and 2-oxo-octanoic acid, respectively. Contrarily, the cresolase activity of MT was inhibited by all type of the above acids. Propanoic acid caused an uncompetitive mode of inhibition (K(i)=0.14 mM), however, the pyruvic, acrylic, 2-oxo-butanoic and 2-oxo-octanoic acids showed a competitive manner of inhibition with the inhibition constants (K(i)) of 0.36, 0.6, 3.6 and 4.5 mM, respectively. So, it seems that, there is a physical difference in the docking of mono- and o-diphenols to the tyrosinase active site. This difference could be an essential determinant for the course of the catalytic cycle. Monophenols are proposed to bind only the oxyform of the tyrosinase. It is likely that the binding of acids occurs through their carboxylate group with one copper ion of the binuclear site. Thus, they could completely block the cresolase reaction, by preventing monophenol binding to the enzyme. From an allosteric point of view, n-alkyl acids may be involved in activation of MT catecholase reactions.

Analysis of DNA fragmentation of porcine embryos exposed to cryoprotectants.

The chemical toxicity of cryoprotectants to porcine embryos was examined by the evaluation of survival and DNA damage after exposure to cryoprotectants. Porcine blastocysts were exposed to 10% of ethylene glycol (EG), 1,2-propanediol (PD) or glycerol (GLY) for 1 h at room temperature (23-25 degrees C) and then cultured in vitro for 24 h. The survival rates of blastocysts exposed to PD and GLY were significantly lower than those of control blastocysts in which the embryos were exposed to carrier solution without cryoprotectants. Significantly more DNA-fragmented nuclei occurred in the cryoprotectant-exposed blastocysts, compared with the control blastocysts. Moreover, the indices of DNA-fragmented nuclei in the blastocysts without blastocoele re-formation after culture were significantly higher than those with blastocoele re-formation, irrespective of the exposure treatment. These results indicate that the exposure of porcine blastocysts to cryoprotectant decreases the survival rates and increases the DNA-fragmented nuclei in embryos.

Effects of cooling ovaries before oocyte aspiration on meiotic competence of porcine oocytes and of exposing in vitro matured oocytes to ambient temperature on in vitro fertilization and development of the oocytes.

Experiments were conducted to evaluate the effects of cooling porcine ovaries to low temperature (4 degrees C, 15 degrees C, 20 degrees C, 25 degrees C or 30 degrees C) for 1 h on the meiotic competence of their oocytes. Moreover, it was determined whether or not the exposure of in vitro matured oocytes to ambient temperature (20 degrees C, 25 degrees C or 30 degrees C) for 1 h affects the fertilization and developmental competence of the oocytes. There was no difference between the proportions of oocytes that underwent maturation to metaphase II when isolated from control ovaries held at 35 degrees C and ovaries exposed to 30 degrees C. However, the percentages of oocytes from ovaries exposed to 25 degrees C or less were significantly lower than those of oocytes from ovaries exposed to 30 degrees C and control ovaries. The proportions of total and normal fertilization of oocytes that had been exposed to 20 degrees C before in vitro fertilization (IVF) were significantly lower than those of control oocytes maintained at 38.5 degrees C. However, cooling in vitro matured oocytes had no effects on their cleavage and development to blastocysts after IVF. These data suggest that exposing porcine ovaries to a low temperature of 25 degrees C or less before aspiration of oocytes may adversely affect their subsequent in vitro maturation. It may be necessary to maintain the oocytes at a temperature of more than 25 degrees C during manipulation of oocytes for retaining the fertilizability of the oocytes.