Cell Journal (Yakhteh)
Year:2009 | Volume:11 | Issue:1 (41)|Papers Count:13

Oct-4/ Pou5f1/ Oct-3, a POU domain family protein acts as a crucial transcription factor during embryonic development. It helps in maintenance of self renewal as well as pluripotential state of embryonic stem (ES) cells. Its expression starts right from 2 cell stage especially prior to 8 cell stage till the blastocyst stage where it is strongly expressed in inner cell mass (ICM). Thereafter, it is located predominantly in primordial germ cells (PGCs) till the birth. It targets particularly those genes which bear an octameric motif ATGCAAAT in promoter or enhancer region. Most of the target genes of Oct-4 are expressed in undifferentiated ES cells and knockdown of Oct-4 results in ES cell differentiation as a result of down regulation of targets of Oct-4 which are expressed in ES cells. Since, Oct-4 is crucial for embryo survival its expression needs tight regulation. Oct-4 is carefully regulated epigenetically as well as by several other factors. DNA methylation and histone modification play an important role in expression of Oct-4 while proximal promoter, enhancer and distal enhancer are the crucial regulatory elements present on Oct-4 upstream region. There is increasing evidence that Oct-4 is expressed in adult stem cells and these stem cells can get converted to cancer stem cells. Since, it is expressed in germ cells, immunohistochemical localization of Oct-4 and thereby its role as a marker for germ cell tumor detection is increasing. Thus, role of Oct-4 is not only restricted as a marker for undifferentiated cells; it is also proving to be crucial factor which targets several genes involved in ES cell survival as well as help in establishing germ cell origin of metastatic tumors.

Objective: Amiodarone as an iodinated benzofuran derivative is a potent antiarrhythmic agent currently used for the treatment of ventricular arrhythmias. Pulmonary toxicity is one of the complications of Amiodarone therapy. The aim of this study was to determine the toxicity of Amiodarone for pneumocytes.Materials and Methods: 14 male white New Zealand rabbits were divided in a control group and an experimental group. The experimental group was subjected to intra peritoneal injection with a single daily dose of 80 mg/kg Amiodarone for two weeks. The control group received only normal saline. At the end of the injection period, the two groups were anesthetized and perfused with Karnovsky fixative. The lung tissue was removed and fixed, then prepared for light and electron microscope studies. Morphometric studies were made on sections to find nucleus profile dimensions.Results: Light microscope observation showed acute changes in the alveolus including congestion of alveolar capillaries and infiltration of red blood cells (RBCs) into the lumen of the alveoli. Electron microscope study of lung tissue revealed abnormal inclusion bodies within type II & I pneumocytes. The micrographs also showed the presence of vacuoles in 5% of the type II pneumocytes. Morphometric studies showed that the nucleus of the cells in the experimental group were smaller than in the control group (p<0.01).Conclusion: These results indicate that Amiodarone administration can cause damage to pnuemocytes and the alveolus of rabbit lung, so the effectiveness of Amiodarone in long term treatment of heart failure patients is limited because of the development of lung toxicity.

Objective: Although in vitro studies have shown that high concentrations of glucose can induce dysmorphogenesis of the embryonic kidney, the possible adverse effects of exposure to intrauterine hyperglycemia on kidney development, especially in regard to nephrogenesis, has not been evaluated.The aim of this study is to investigate the effects of maternal diabetes on glomeruli structures of the offspring, focusing on the following parameters: glomeruli volume and number, mesangium volume, mesangial cell number and glomerular capillary volume.Materials and Methods: Before mating, fifteen female Sprague Dawley rats, divided into three groups, were diabetes induced by a single intraperitoneal dose of 65 mg/kg streptozotocyn (STZ). After 30 days of breast feeding, ten offsprings from each group (two per mother) were randomly selected for kidney removal. The kidneys were weighed and their tissues were processed for light microscopy. Glomerular features were evaluated quantitatively using dissection as well as the Cavalieri method and were then compared with sham and control groups.Results: At birth, the mean body weight of diabetic mothers’ offspring (DO) was significantly lower than that of the control group’s offspring (CO) and sham group’s offspring (SO) (p=0.001), however, the mean body weight of the 30 day-old DO was not lower than that of CO and SO (p>0.05). The total renal volumes, cortical volumes, glomerular mean and total volumes, total mesangeal volumes, total capillary volumes and total glomerular numbers were significantly lower in the DO than in CO and SO (p<0.05). The numerical density of glomeruli and mesangial cells per glomeruli were significantly greater in DO than in CO and SO (p<0.05).Conclusion: We concluded that intrauterine hyperglycemia is accompanied by a nephron deficit which may not be compensated within the first 30 days after birth.

Objective: Morphological changes of CA1 neurons in rat hippocampus after transient and permanent focal cerebral ischemia were studied to clarify the nature of postischemic cell death in the subfield.Materials and Methods: Male adult rats were divided into 3 groups: Control (Shamoperated), transient ischemic group (30 minutes of MCAO followed by 48 hours of reperfusion), and permanent ischemic group (48 hours of MCAO). After the mentioned times, deep anesthesia was induced in the rats and their brains were removed and processed for transmission electron microscopy (TEM) and evaluation.Results: Electron-microscopic examination on day 2 showed key morphological signs of apoptosis in the permanent ischemic group, while morphological signs of necrosis were observed in the transient ischemic group.Conclusion: These results suggest necrosis (as dominant mechanism of neuronal death after transient ischemia) and apoptosis (after permanent ischemia) to be involved in neuronal death.

Objective: In this study, we examined the effect of different doses of bone morphogenetic protein 4 (BMP4) on CCE mouse embryonic stem cells (ESCs) viability and proliferation rates in order to improve the outcome of induction processes and make a system with highest viability and proliferation rates for further studies on BMP4 roles in multiple developmental stages.Materials and Methods: Expression of Oct-4 was studied and confirmed in this cell line immunocytochemically. Also, in order to evaluate the proliferation and viability rates in BMP4-treated cells, ESCs were cultured in Dulbecco's Modified Eagle Medium (DMEM) containing different doses of BMP4 (0, 0.01, 0.1, 1, 5, 25, 50 and 100ng/ml). The mean number of whole cells and living cells were considered as proliferation and survival rates respectively. Data analysis was done with ANOVA test.Results: The results showed that there were significant differences between the mean percent of viability between 1ng/ml and 0 ng/ml (control) and 50 and 100 ng/ml BMP4 (p£0.01), as well as between 5 ng/ml and 0, 0.01, 0.1, 25, 50 and 100 ng/ml BMP4 (p£0.02). Also, significant differences were observed in proliferation rates between 5 ng/ml and 0, 0.01, 0.1, 1, 25 and 100 ng/ml BMP4 (p£0.01), 25 ng/ml and 0.01, 1 and 5 ng/ml BMP4 (p£0.01), as well as between 50 ng/ml and 0.01 and 0.1 ng/ml BMP4 (p£0.001).Conclusion: The results suggest that addition of 5ng/ml BMP4 had the best effects on the proliferation and viability rates of CCE mouse ESCs.

Objective: This study is an attempt to examine the anti apoptotic effects of BIO on rat MSC culture.Materials and Methods: Rat marrow primary cell culture was established and exposure groups were defined; cultures with 0.01, 0.1, 1 mM BIO. Cells cultured without BIO treatment were used as controls. During culture expantion, the average doubling time, as an index of the rate of cell growth, were determined and compared. To examine whether or not BIO is able to protect MSCs against apoptosis, the passaged-3 cells from each group were induced to undergo apoptosis with the addition of TNF-a (Tumor necrotic factor-a). Three days after, the cultures were quantified in terms of the percentages of apoptotic cells using either the Tunnel or Annexin V staining method.Results: Marrow cells cultivated with 0.1 and 1 mM BIO appeared to expand at a significantly more rapid rate than the 0.01 mM BIO and the control cultures (p<0.05). Tunnel staining indicated that in 1 mM BIO-treated groups, there were lower percentages of apoptotic nuclei than in groups with other concentrations of BIO (p<0.05). The BIO protective effect appeared to be dose-dependent in that the cultures with high BIO content possessed less apoptotic nuclei. The results obtained by Annexin staining were in agreement with the results of Tunnel staining. The Annexin method additionally takes into account the early apoptotic cells which are not detectable by the Tunnel method.Conclusion: Taken together, it seems that cultivation with BIO could both increase the growth rate of marrow cells and protect MSCs against induced apoptosis.

Objective: Radiation myelopathy (RM) is known as a serious complication of head and neck radiation therapy. Furthermore, the radioprotective roles of melatonin have been investigated on different tissues. The aim of this study was to assess the radio protective effects of melatonin on biochemical, histopathological and clinical manifestations of RM in the rat cervical spinal cord.Materials and Methods: Four groups of rats were investigated as follows: The control group was treated with vehicle. The second group (melatonin only) was intraperitoneally injected with 100 mg/kg melatonin. The third group's (radiation) cervical spinal cord area was irradiated with 22 Gy cobalt-60 gamma-rays. The fourth group (melatonin plus irradiation) received 100 mg/kg melatonin intraperitoneally, and after 30 minutes their spinal cord area was irradiated with 22 Gy gamma radiations. Five animals from each group were randomly selected. 72 hours, 8 and 22 weeks after irradiation for analysis of malondialdehyde (MDA) and glutathione (GSH) levels, and underwent histopathological studies.Results: The MDA levels in the irradiation group were significantly higher than in the control group (p<0.001). Furthermore, the GSH levels in this group were significantly lower than that of those in the control group (p<0.001). Administration of melatonin markedly reduced MDA (p<0.001) and increased GSH (p<0.05) levels in this group. Demyelination and clinical signs of myelopathy were decreased in the melatonin plus irradiation group in comparison to the irradiated group.Conclusion: Our study confirms the radioprotective effects of melatonin at early stages of biochemical, as well as late histological and clinical changes in the spinal cord.

Objective: Changes in chloride cell abundance, Na+, K+-ATPase immunolocalization and activity were investigated in the gills of the golden grey mullet, Liza aurata, fry acclimated to freshwater (FW) and different salinities (12‰, 36‰ and 46‰).Materials and Methods: Na+, K+-ATPase localization was performed through immunofluorescence light microscopy using a mouse monoclonal antibody IgGa5. Quantitive analysis of Na+, K+-ATPase intensity was analyzed using Optima’s version 6.51 image analysis software (Media Cybernetics, Silver Spring, MD, USA).Results: In FW, the fluorescent cells (chloride cells) were observed on the epithelia of filaments (mainly in inter-lamellar regions) and on the lamellae. Following transfer to 12‰ salinity, the abundance of Na+, K+-ATPase immunofluorescence cells on the filaments decreased 1.7-fold, and no immunofluorescence cells were detected on the lamellae. Samples from 36‰ and 46‰ salinity showed a high density of chloride cells on the epithelia of filaments, and a few cells on the lamellae. Na+, K+-ATPase intensity did not change significantly with an increase in salinity from 36‰ to 46‰ but it was significantly higher (p>0.05) in the FW compared to 12‰ salinity. There was no significant difference between gill Na+, K+-ATPase activity in FW and 12‰ salinity, but it was significantly higher (p>0.05) in the fish acclimated to 36‰ and 46‰ salinity (3.3- and 5.1-fold) compared to 12‰.Conclusion: The capability of L. aurata fry to change the number and size of gill chloride cells, as well as their activities indicate the high degree of adaptability of this fish to a wide range of salinity.

Objective: To date, several scaffolds have been fabricated for application in bone tissue repair. However, there remains a need for synthesis of scaffolds with better mechanical properties, which can be applied to defects in weight-bearing bones. We constructed a composite ceramic bioscaffold of hydroxyapatite-alumina and silicon carbide (HA-Al2O3-SiC) to take advantage of the mechanical properties of this combination and show that it supports osteoblast-like cell attachment and growth.Materials and Methods: Ceramic composite microporous scaffolds were synthesized using an organic template (commercial polyurethane sponge with an open, interconnected microporosity). Osteoblast-like cells (Saos-2) were then cultured on the scaffold and their growth pattern and viability were compared with those cultured in cell culture-treated flasks. Scanning electron microscopy (SEM) was used to assess cell attachment and migration.Results: The fabricated scaffold shows fairly uniform pore morphologies. Cell growth and viability studies show that the scaffold is able to support osteoblast attachment and growth. However, SEM images indicated that the cells do not spread optimally on the scaffold surfaces.Conclusion: Our data suggest that that a ceramic hydroxyapatite-alumina and silicon carbide composite scaffold is a viable option for bone tissue repair. However, its surface properties should be optimized to maximise the attachment of osteoblasts.

Rodgers (Rg) and Chido (Ch) are blood-group antigens and they determine the fourthcomponent of human complement C4. Rodgers and Chido are associated with two C4 isotypes (C4A and C4B). In addition to genotype determination, study on expression of Rg and Chido could be useful in disease studies.DNA was extracted from the whole blood of 60 normal individuals. Then, PCR amplification of C4d gene fragment was followed by restriction digestion. This study demonstrated that the frequency of Ch and Rg in Iranian healthy population was 98.3 and 93.4 percent, respectively. Additionally, 6.6 percent of the studied population showed Chido-positive, Rodger-negative and 1.7 percent showed Rodger-positive, Chido-negative genotype. It may be concluded that upon receiving blood transfusion, 6.6 and 1.7 percent of individuals could produce anti-Rg and anti-Ch antibodies, respectively.