Cell Journal (Yakhteh)
Year:2008 | Volume:10 | Issue:3 (39)|Papers Count:9

Chemokines are a small group of related chemoattractant peptides that play an essential role in the development and homeostatic maintenance of the immune system. They control the recruitment of cells needed for the induction and activation of innate and adaptive immune responses. Stromal cell-derived factor 1 (SDF-1) and its receptor (CXCR4) have role in regulation of trafficking of normal hematopoietic stem cells (HSCs) in their homing/ retention in bone marrow, also they control lymphocyte trafficking, angiogenesis, cell adherent or migration. In addition, chemokines and their receptors involved in several auto- immune diseases such as inflammation, HIV. In fact, chemokines are involved directly or indirectly in almost every aspect of tumorigenesis. They mediate survival and metastatic spread of tumors; promote new blood vessel formation (neovascularization). SDF- 1/ CXCR4 axis for migration, enhanced resistance to apoptosis and an increased capacity for drug resistance a number of therapeutic strategies have been proposed to target almost every step of the chemokine or chemokine receptor involvement in tumors. Yet, despite occasional success stories, most of them appear to be ineffective or impractical,. The strategy would only be effective if it also promoted antitumor activity and more study is needed to clear the tumor relapse mechanism..

Skin replacement has been a challenging task in wound healing resulted from burn. The application of laboratory based tissue expansion techniques is a potential solution to the problem of surface area cover. Fortunately, considerable progress has been made in approaches to allograft and autograft skin transplantation in order to replace skin temporarily or permanently. Despite of this progress, development of new treatments for burn victims are still a problem in cultured skin grafts. Hair follicles, sweat glands and other features of normal skin are absent in cultured skin. Scientists believe that Stem cells with unique characteristics including self renewal and differentiation potential offer a possible way for reconstruction of some structures within the wound. So, enhanced understanding of stem cell potentials may help develop novel therapies to overcome the problems in wound healing.

Objective: Investigation of the suitability of electrospun Poly (e-caprolactone) (PCL) nanofiber scaffold for the Vero cell culture.Materials and Methods: Electrospinning was used for production of PCL nanofibers scaffolds. Scanning electron microscopy (SEM), MTT assay, hematoxylin staining and histology analysis were used to investigate the cell morphology, viability, attachment and infilteration of the vero cells on the PCL nanofiber scaffolds.Results: The results of the MTT assay, SEM images and hematoxylin staining showed that Vero cells attach and spread on PCL nanofiber scaffolds. The proliferation of Vero cells is as well as that of control group, but histological analysis showed the lack of cell infilteration into the scaffolds, which was found to be due to the small diameters of the pores of nanofibrous scaffold.Conclusion: The result of this study show that PCL nanofiber scaffolds are suitable for cell culture, proliferation and attachment and Vero cells attach and proliferate on PCL nanofiber scaffolds.

Objective: Olfactory ensheathing cells (OECs) has been shown to have a neuroprotective effect after transplanted in brain and spinal cord injury (SCI). This study was conducted to determine the possible beneficial results of transplantation of fetal olfactory mucosa (FOM) that was the source of OECs in the recovery of locomotor function and in spinal tissue sparing after spinal cord hemisection.Materials and Methods: Forty-eight adult female Sprague-Dawley rats were spinally hemisected at the L1 level and were randomized into the three groups of 16 animals. The first group, immunosuppressed injured animals were received cyclosporine A (CsA) and FOM graft. The second group was received CsA and fetal respiratory mucosa (FRM) graft, and the control group; non-immunosuppressed rats were received saline and gel foam. Locomotor performance was assessed weekly for 8 weeks after lesion, using locomotive rating scale developed by Basso, Bresnahan and Beattie (BBB). After behavioral assessment, the spinal cord was examined by a histologist for spinal tissue sparing.Results: From weeks 6-8, the functional recovery of the FOM rats significantly increased in comparison to the FRM, although a significant difference in tissue sparing was not apparent. From weeks, 2-8 the functional recovery of the FOM and FRM groups as well as tissue sparing of the FOM group increased significantly compared to the control group.Conclusion: Thus, the FOM treatment may be effective to promote functional recovery and partially preserving tissue sparing.

Objective: This study describes our experiences in reproductive cloning using two different procedures resulting in birth of the first successfully cloned sheep in Iran and the Middle-East, nick-named "Royana".Materials and Methods: Abattoir-derived sheep oocytes were enucleated after in vitro maturation for 18-20hrs and then reconstructed by ear-derived sheep somatic cells using two different procedures of renucleation (subzonary, intracytoplasmic), embryo culture (coculture, sequential medium) and embryo transfer (intra fallopian, intra uterine). Pregnancy status and fetal development were followed regularly and elective cesarean was inducted on day 145 of pregnancy. Histopathological and genetical examinations were performed on either aborted and delivered clones for confirmation different aspects of cloning.Results: The two procedures were both efficient in producing early and/or advanced cloned embryos, establishing early and/or advanced stages of pregnancy till delivery. Four pregnancies were detected; one were failed at early pregnancy, one aborted on day 90, one was still born and the fourth delivered to a healthy male lamb nick named "Royana".Conclusion: Many different approaches have been developed for mammalian cloning which all are judged by their ultimate potency for establishment of successful pregnancies terminated to healthy/viable clones. As a preliminary study toward establishment of the technology, this study also successfully examined the competency of two procedures of somatic cell nuclear transfer (SCNT). However, the overall low efficiency of SCNT indicates that many different aspects of the technology remain to be dissolved.

Objective: Leishmania major P4 gene is normally expressed during amastigote form of the parasite and can be good candidate for producing an effective vaccine. In this study we cloned this gene in suitable vector (pQE-30) for further vaccine preparation studies.Materials and Methods: Leishmania promastigotes were grown in N.N.N. medium and culture in RPMI 1640 cell culture medium. Total genomic DNA was extracted by centrifugation of promastigotes. The pellet was suspended in lysis buffer and followed by boiling method. PCR was carried out using P4 gene specific primers. PCR product was detected by agaros gel electrophoresis and cloned into Bluescript plasmid via T/A cloning method. Reaction was transformed into XL1- Blue competent cell and recombinant plasmid screened using agar plate contained X-gal and IPTG. The product was extracted, digested by restriction enzyme and electrophoresed on agarose gel.Results: Plasmid was extracted and cloned gene was released by restriction enzyme and subcloned into pQE-30 expression vector.Conclusion: This construct is ready for protein expression in in-vitro.

Objective: Biphasic ceramics of hydroxyapatite and three calcium phosphate (HA/ TCP) are increasingly being used as a bone substitute in regenerative surgery. To increase the bone forming capacities, HA/TCP Scaffolds could be enriched with osteogenic factor like mesenchymal stem cells (MSCs) which is the subject of present study.Materials and Methods: Passaged-3 culture-expanded MSCs of canines bone marrow were suspended in a diluted collagen gel and loaded onto commercially-available HA/TCP ceramics. The cell-loaded scaffolds were then autologously implanted along with the control cell-free scaffolds in masseter muscles of the four mongrel dogs. Eight weeks later, the parts of their muscles including the implants were prepared for a light microscopy. To quantify the amount of bone formation, the slides of both studied groups were photographed and the percent area of the newly formed bone was calculated using Image-Pro Plust software.Results: According to our observations, the implants were appeared to be encapsulated by fibrous tissue within the muscle. No cartilage tissues were observed in implantation site. Histological observation indicated that ectopic bone was formed in both MSCs-loaded scaffolds as well as the control cell-free implants. The percentage of newly formed bone for cell loaded HA/TCP scaffolds was %29.12±6.01 compared to %23.55±4.99 of the cell-free implants (p<0.05). Furthermore, lamellar mature bone was only observed in cells/scaffold groups.Conclusion: Taken together, it seems that MSCs enhance bone formation capacity of HA/TCP. The formed bone following MSCs/scaffold composite implantation appeared to be histologically lymature lamellar bone.

Objective: Recent evidence suggests that Leukemia Inhibitory Factor (LIF), a member of interleukin-6 family, has biological actions on preimplantation embryo development. Also it is established that Epidermal Growth Factor (EGF), a strong mitosis-promoting agent, improves the preimplantation embryo development by increasing the cell metabolism and proliferation. The purpose of the present study is to investigate the effects of these factors, alone and in combination together, on preimplantation and development of the embryo.Materials and Methods: Six to eight weeks old NMRI mice were super ovulated by injection of 10IU PMSG and 10IU hCG, then the mated mice were killed 46 hours later. Their oviducts were flushed, two-cell embryos collected and divided randomly to the four groups as following: Control, treatment 1 (LIF), treatment 2 (EGF), treatment 3 (LIF+EGF). In each group, the embryos were cultured in an incubator at 37oC with 5% CO2 and 90% humidity for 72hrs. The state of embryo development was evaluated in 24,36,48,60 and 72hrs following the embryos cultures. By the end of the cultures, cell apoptosis was studied by the terminal deoxynucleotidyl transferas-mediated dUTP nick end-labeling (TUNEL) technique.Results: Significant difference was detected in the rate of hatching in the LIF and LIF+EGF groups. This difference was also seen in the rate of blastocyst formation after 36hrs (p<0.05) and in the average of the total cell number (p<0.05) after 72hrs. In comparison to the apoptotic index, there was no significant difference between the control and treatment groups.Conclusion: The findings in this study show a beneficial effect of LIF and EGF on the blastocyst formation, hatching and its total cell numbers in vitro.