Cell Journal (Yakhteh)
Year:2010 | Volume:11 | Issue:4 (44)|Papers Count:14

Embryonic stem cells are characterized with two specific properties: self renewal and differentiation potential. Embryonic stem cells are pluripotent cells that can be differentiated into three kind of germ layers; ectoderm, endoderm, mesoderm. These properties make them ideal for developmental research, toxicology and transplantation in animal model of human diseases.  These cells can be differentiated spontaneously into three germ layer cells, but in direct differentiation, molecules and growth factors involved in natural development of desired cells must well characterized to gain a proper differentiation in vitro.There are increasing numbers of death because of liver disease and failure of organ transplantation in our country and the world. This made stem cell scientists to work on embryonic stem cell differentiation to hepatocyte like cells to create an accessible cell source in regenerative medicine of liver disease in the future, and also to establish stem cell derived hepatocyte for in vitro screening of drugs.In this review we will summarize the process of liver development including molecules and growth factors incorporate in the liver development as a template for in vitro differentiation of mouse and human embryonic stem cells and then we will discuss the related studies and techniques for analyzing functionality of differentiated cells.

Angiogenesis, the development of new blood vessels from existing vasculature, is essential in physiological processes such as growth and development, wound healing and reproduction. It is also involved in pathological conditions such as tumor growth, metastases, and certain chronic diseases. Angiogenesis is dependent on a delicate equilibrium between endogenous angiogenic and antiangiogenic factors. However, under pathological conditions, this tight regulation becomes lost which can result in the formation of the different diseases, including corneal neovascularization, endometriosis, obesity, atherosclerosis, diabetic retinopathy, psoriasis and cancer. In general, the process of angiogenesis is a multi-factorial and highly structured sequence of cellular events comprising migration, proliferation and differentiation of endothelial cells and finally vascular formation, maturation and remodelling. Due to the critical role of angiogenesis in physiological and pathological conditions, scientists have designed various experimental models to assay angiogenesis in vitro, ex vivo and in vivo. Currently, these experimental models are used by many researchers for several applications such as discovering angiogenic and anti-angiogenic agents, and thereby for future therapeutic applications.

Introduction: The purpose of this study was to evaluate body and testis weight, testis tissue, counts, motility, viability, morphology, and chromatin quality of epididymal sperm, as well as the testicular spermatid number (TSN) per gram of testis, and daily sperm production (DSP) in L-carnitine treated mice.Materials and Methods: In the present study, adult male NMRI mice (mean age of 4 weeks) were administered L-carnitine by gavage for two weeks.  The experimental groups received 1mg L-carnitine/100 ml deionized water and 10 mg L-carnitine/100 ml deionized water, respectively. The control group did not receive L-carnitine. All samples were assessed according to World Health Organization (WHO) criteria. Sperm morphology was assessed with papanicula staining. Sperm chromatin quality was assessed using aniline-blue staining.  The left testes were fixed in Bouins solution for histological examination and the end slices were stained with hematoxilin and eosin (H&E). The right testis was homogenized, and TSN and DSP were calculated with an improved neubauer haemocytometer and respective formula.Results: Administration of L-carnitine induced significant reduction in body weight (p<0.05) and an increase in tchromatine quality (p<0.05). Amongst the other parameters no significant differences were observed in all groups.Conclusion: These results show that oral administration of L-carnitine to mice with normal spermatogenesis does not have any significant effect on the reproductive systems. Thus, L-carnitine seems to be ineffective in normospermic animals.

Objective: To evaluate and compare the gene expression profiles of Ninjurin-1 and Ninjurin-2 with the expressions of L1 family of cell adhesion molecules (NCAM-L1), neural cell adhesion molecules (NCAM), and N-cadherin during the course of neural differentiation of mouse neural stem cells (NSCs).Materials and Methods: Briefly, for neural stem cell isolation, the frontal part of an adult mouse brain was minced in phosphate buffered saline (PBS) and digested by an enzyme solution which contained hyaluronidase and trypsin. Isolated cells were cultured in medium supplemented by epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). After seven days, primary neurospheres appeared in culture medium. After transfer to poly-L-ornithine coated dishes that contained culture medium supplemented with 1% fetal bovine serum (FBS), the primary neurospheres differentiated into neural-like and neuroglial-like cells. Differentiated cells were examined by morphological, immunocytochemical, and molecular evaluations.Results: Our results showed that isolated cells from the preventricular area of mouse adult brain proliferated in medium which contained EGF and bFGF, and expansion of the cells continued until passage 14 without losing morphological and neurogenesis capacity. Multiple passaging confirmed the stemness nature of the isolated cells. The isolated NSCs were able to differentiate into neural-like and neuroglial-like cells after transfer to poly-L-ornithine coated dishes that contained culture medium supplemented with 1% FBS. Molecular studies for NCAM, NCAM-L1, and N-Cadherin genes, as well as immunocytochemical analysis for NCAM-L1 and NCAM proved the differentiation. Our data also revealed, for the first time, gene expression profiling of Ninurin-1 and Ninjurin-2, two novel cell adhesion molecules (CAMs), during the course of differentiation of neural stem cells. Conclusion: The induction of neural differentiation in mouse NSCs initiates the expression of NCAM-L1, NCAM, and N-cadherin which can be the proof of complete neural differentiation. In addition, our results indicate that the expression of Ninjurin-1 increases after neural induction much like the expressions of NCAM-L1, NCAM, and N-cadherin. This data suggests the probable importance of Ninjurin-1 in both the morphology and function of neural cells. The data in this study also reveals that the expression of Ninjurin-2, in contrast with Ninjurin-1, initiates and continues until the differentiation termination point. This suggests that although Ninjurin-1 and Ninjurin-2 share conserved hydrophobic regions for their transmembrane domains, their roles in nerve cells are probably different.

Objective: Two types of stem cells are found in the bone marrow: hematopoietic stem cells and marrow stromal cells (MSCs). Is it possible to induce the differentiation of bone marrow stromal cells into neural cells in vitro and subsequently transplant them into the brain? This might help repair neural lesions observed in some neurodegenerative diso ders such as Parkinson’s disease (PD).Materials and Methods: In this study, cultured MSCs were incubated in serum free medium containing 10-8 M selegiline for 24 hours and cells were cultured for another 48 hours in α minimal essential medium (a-MEM) containing 20% fetal bovine serum (FBS).Then selegiline-treated cells were immunostained for neuronal markers such as NF-200 and TH.Results: Cell counting results showed that Selegiline at doses of 10-6, 10-7 and 10-8 M increased the mean percent of viable cells. The most effective dose of Selegiline for diferentiation of bone marrow stromal cells (BMSCs) was 10-8 M. Molecular studies indcated that the expression of BDNF, GDNF, NGF, NT3, and NT4/5 genes were increased in Selegiline-treated cells compared to non-treated group.Conclusion: BMSCs can be directed to a neural fate in vitro and can be considered as a cell source in neurological disorders for autograft therapy.

Objective: In this study the effects of met-enkephalin on tumor infiltrating lymphocytes for cancer treatment in fibrosarcoma bearing mice was evaluated.Materials and Methods: Initially, to obtain the most effective dose and treating time for the induction of CD25, splenocytes were cultured with several doses of met-enkephalin. Flowcytometry was used to evaluate CD25 expression. The best dose and treating time were used to stimulate tumor infiltrating lymphocytes (TILs). To obtain pure CD4+ and CD8+ cells, TILs were taken from tumors by enzymatic tissue disaggregation and purified by magnet bead cell separation. After TILs stimulation they were re-injected into three groups of other fibrosarcoma bearing mice. The first group received only CD4+ TILs, the second group received only CD8+ TILs, and the third group received both CD4+ and CD8+ TILs. A fourth group that served as the control group received only phosphate buffered saline (PBS). The effect of this treatment on tumor volume, mice survival, effector cells, regulatory T cells and serum level Bcl-2were evaluated. To analyze data in both the experimental and control groups one way ANOVA was used followed by the Tukey test. P value<0.05 was considered significant.Results: Treatment with met-enkephalin at a dose of 10-10 M for 6 hours was most effective in CD25 induction on the splenocytes of Balb/C mice. There were a significant decrease in tumors growth in both the CD8+ and CD4+ activated TILs injected groups (p<0.044 and p<0.017, respectively). The result of the CD4+ plus CD8+ activated TILs injected group was not significantly different from control group (p<0.661). There was an improvement in survival amongst the mice in all treated groups (p<0.001 for all three groups). FoxP3 levels in all groups were significantly low (p<0.001, p<0.002 and p<0.001 for the CD4+, CD8+ and CD4+ plus CD8+ activated TILs injected groups, respectively). CD25 and Bcl-2 expressions were higher in the treated groups, but only the CD4+ activated TILs injected group was significant (p<0.002 for CD25, p<0.001 for Bcl-2).

Objective: To study the possible association between high levels of fetal haemoglobin (HbF) in b-thalassemia intermedia patients and HS-111 and 3`HS1 sequence variations.Materials and Methods: In this study, the 3' HS-1 and HS-111 regions of 30 b-thalassaemia intermedia patients (bo/bo) with high levels of HbF, 21 b-thalassemia major patients and 40 normal Iranian individuals were analyzed by  single-strand conformation polymorphism (SSCP) and polymerase chain reaction (PCR) sequencing. Results: Two nucleotide variations in 3' HS111 (-21A>G) and 3`HS1 (179C>T) were identified. The most frequent sequence variation was 3' HS111 (-21A) in the intermedia patients and 3`HS111 (-21G) in the major thalassemia patients. In contrast to the 3`HS1 marker, both 3'HS111 A and G variants showed a correlation with each studied group.Conclusion: The HS111 marker in conjunction with other parameters could be used as appropriate genetic markers to discriminate b-thalassemia intermedia patients (bo/bo) with high levels of HbF from b-thalassemia major patients.

Objective: cortisol is the major corticosteroid in fish osmoregulation and Persian sturgeon is one of the endangered and economical species of the Caspian Sea sturgeons; this study is one of the first to investigate the effects of cortisol on one species of the Acipenserids species. Materials and Methods: Samples were fixed in Bouin’s solution, dehydrated, embedded with paraplast and subsequently sectioned. Immunohistochemical studies were performed by using IgGα5 and flourescin isothiocyanate conjugated (FITC) antibodies through fluorescence light microscopy. Measurements of the chloride cells were examined by Image Tools (2.0) image analysis software.Results: In the cortisol treatment there were 492 chloride cells per mm2 of the gill epithelium which was significantly (p=0.01) higher than the control group (289 chloride cells). The lengths of chloride cells were 13.9325±0.5 µm and 16.0935±0.5 µm in the cortisol and control groups, respectively; as reported, the length was significantly smaller in the cortisol group (p=0.02). The widths of the chloride cells were 7.718±0.3 µm and 7.922±0.4 µm in the cortisol and control groups which were without any significant differences. Both the dispersion and numbers of chloride cells in four locations (on the filament, basement of the lamellae, interlamellar region and on the lamellae) were significantly different (p=0.01) between the two experimental groups.Conclusion: exogenous cortisol can cause significant cellular and morphometric changes in gills of the Persian sturgeon fry for their adaptation to salinity.

Objective: Immunohistochemical localization and immunoreactivity of insulin-like growth factor-I (IGF-I) were investigated during the ovarian developmental stages in Persian sturgeon. In addition, the effects of growth hormone and thyroxine were investigated on IGF-I immunoreactivity in vitro. Materials and Methods: Ovarian samples were taken from two brood stocks (caught from the sea and from a river) during their reproductive migration and at three different developmental stages based on their polarization index (PI). The effects of two hormones on IGF-I immunoreactivity were studied at two ovarian developmental stages (PI>0.1 and PI<0.07). In both experiments the immunoperoxidase method was performed in order to detect immunohistochemical localization and immunoreactivity of IGF-I.Results: Immunohistochemical localizations of IGFI were detected in the follicular layers. There was no significant immunoreactivity difference between the two brood stocks, however in the river brood stock IGF-I immunoreactivity was more intense in the ovaries with PI<0.07 than of PI>0.1 (p<0.05). Growth hormone (10 ng/ml) increased IGF-I immunoreactivity in ovarian samples from the river brood stock when their PI was less than 0.07, however thyroxine had not such effect (p<0.05).Conclusion: Our results showed that IGF-I is present in the ovaries of Persian sturgeon and its reactivity is different among their gonadal development stages. This may support a role for IGF-I during reproductive physiology in female brood stocks of the Persian sturgeon. Moreover, growth hormone is a potential hormone to increase IGF-I immunoreactivity in the ovaries of this species.

Objective: A study of the effects of triploidy on some haematological indices of rainbow trout.Materials and Methods: Haematological characteristics such as red blood cell (RBC) dimensions, area and volume, RBC and white blood cell counts (WBC), haematocrit (Hct%), hemoglobin (Hb), mean erythrocytic hemoglobin (MEH), mean erythrocytic volume (MEV), mean erythrocytic hemoglobin concentration (MEHC) and RBC abnormalities were measured in 14 and 15 ten month old rainbow trout, respectively.Results: Triploidy significantly increased all morphometric indices containing dimensions, nuclear area and volume of RBCs in compare to diploid fish (p<0.05). The triploid trout had lower numbers with larger RBC sizes. The decrease in RBCs was compensated by an increase in MEV. Thus, triploidy did not affect Hct% (p>0.05). A significant reduction in Hb was observed in triploids (7.4 g/dL) when compared to diploid fish (9.2 g/dL; p<0.05). The MEH values were 82.8 and 116.8 mg/cell in diploids and triploids, respectively (p<0.01). There were no significant differences in MEHC levels between diploids and triploids (p>0.05). Triploids had lower numbers of WBCs and showed higher erythrocytic abnormalities than diploids (p<0.01).Conclusion: Numerous haematological indices of rainbow trout were affected by the ploidy levels, therefore it is expected that optimum culture conditions should vary between diploid and triploid fish.

Objective: Considering the inhibitory effect of integrin-activity modulator (manganese) on the development of morphine tolerance; in this study we have tried to assess the effect of chronic administration of both morphine and manganese on the expression levels of b1 and b2 integrins in the dorsal horn of the lumbar spinal cord.Materials and Methods: Morphine tolerance was induced by intrathecal injection of morphine, 15 µg/rat twice a day for five days. In order to study the effect of manganese on tolerance development; we injected manganese alone or in combination with morphine. The analgesic effect of morphine was assessed by using the tail flick test. Semi-quantitative reverse transcription - polymerase chain reaction (RT-PCR) was used to assess the expression levels of b1 and b2 integrins.Results: As assessed on day 6, five days administration of morphine significantly increased the expression levels of integrins b1 and b2. Combined administration of morphine and manganese, which inhibited morphine tolerance, prevented the effect of morphine on integrins’ expression.Conclusion: Increased expression of integrins may be due to direct effect of chronic morphine or a negative feedback that resulted from the potent inhibitory effect of morphine on integrins’ activity.  It seems that the activating of integrins via manganese in the presence of morphine can reverse feedback and consequently the effect of chronic administration of morphine on b1 and b2 integrins’ and expression. Our findings suggest a role for intracellular matrix molecules in the development of morphine tolerance and possibly other forms of synaptic plasticity.

The purpose of this survey is to identify the number of scientific papers written about stem cells by Iranian researchers. In this regard, to use the results for future stem cell research by Iranian scientists. In this survey we have used scientometric method as a single quantitative method. The statistical population of this article includes all articles published by Iranian researchers from the earliest records until the end of 2007 as cited in the ISI database, which is the web based version of science citation index (SCI). The results show that Ghavamzadeh with 19 articles is the most productive Iranian researcher in the ISI database. The majority of published articles have been written by more than one author. A review of the findings show that Iranian researchers have been successful in stem cell production.