ABSTRACT
There is increasing evidence that dermis contains adult multipotent stem cells. To investigate the effects of dermis-derived multipotent cells on wound healing, we transplanted a clonal population of dermis-derived multipotent cells (termed as DMCs) by topical and systemic application into the skin wound of rats with simple wounds and rats with combined wound and radiation injury. Our results suggest that both topical and systemic transplantation of DMCs accelerate the healing process in rats with a simple wound; the promoting effect by topical transplantation occurs earlier than systemic transplantation. However, systemic transplantation of DMCs promotes the healing process in irradiated rats, while topical transplantation of DMCs fails. Further studies on the mechanisms of DMCs to promote wound healing indicate that the supernatant of DMCs could promote the proliferation of fibroblasts and epidermal cells; DMCs expressed transcripts of a series of cytokines and extracellular matrix molecules, including VEGF, PDGF, HGF, TGF-beta, ICAM-1, VCAM-1, and Fibronectin, which were closely related to the wound healing by DNA microarray analysis. The implanted DMCs can engraft into recipient skin wounded tissues after transplantation by the FISH analysis with Y-chromosome-specific probe. Systemic transplantation of DMCs also promotes the recovery of peripheral white blood cells in irradiated rats. These results demonstrate the different effects of DMCs on wound healing in non-irradiated and irradiated rats and illustrate the importance of optimizing wound healing via the topical or systemic transplantation of stem cells.
Subject(s)
Multipotent Stem Cells/transplantation , Skin/cytology , Wound Healing , Animals , Cell Division , Cells, Cultured , Cytokines/genetics , Female , In Situ Hybridization, Fluorescence , Lymphocyte Activation , Rats , Rats, WistarABSTRACT
Objective To evaluate the biological effect of a kind of protective cover against inhalation of depleted uranium (DU) dust particles. Methods At 1 and 3 d after inhalation of DU dust particles, uranium concentrations in the blood, lung, bronchia, kidney, and liver of the rats in the protected group and non protected group were measured and the efficiency of protection was calculated. Results Uranium levels in all tissues and fluids of the rats in the protected group decreased significantly to 71.2%-96.1% as compared with those in non protected group. Conclusion The protective cover is effective to reduce the harm due to inhalation of DU dust particles.
ABSTRACT
Objective To find out the best method for elimination of uranium contamination in rat tissues as low as possible by removal of shrapnel fragments. Methods Experimental rats were divided into six groups: route group, decontamination before surgery group, decontamination in incision group, changing surgical appliances group, removing tissues around group, and comprehensive method group. Uranium concentrations in tissues and fluids in all groups were measured at 7, 14, and 21 d after operation. The efficiency of decontamination by different methods was compared. Results The highest uranium concentration in tissues was found in the route group, but the lowest in the comprehensive method group, and the second lowest in removing tissues around group. Conclusion The comprehensive method is the best one in all of the surgical removal methods. The soft tissues around DU shrapnels should be removed if they are not critical organs.
ABSTRACT
Objective To observe the changes of glucocorticoi d receptor (GR) in hepatic cytoplasm in rats after scalding-induced pathologic al stress and its regulation. Methods The receptor binding capa city (R0) and the apparent dissociation constant (Kd) of GR in hepatic cytopla sm of normal, low-degree and heavy-degree scalded rats were measured with rad io-ligand binding assay, with ［3H］ dexamethasone as ligand. The changes of R0 and Kd of GR were regulated by injections of anti-rat TNFα, IL-1β a ntibodies, α-melanocyte-stimulating hormone (α-MSH), and KPV peptide( Ac- D-Lys-L-Pro-D-Val) respectively in vivo. Results The R 0 of GR in hepatic cytoplasm in rats 12 h after heavy-degree scalding ［Mass action robust: （205.52±30.14） fmol/mg; Scatchard: （208.45±30.78） fmol/mg ］were significantly lower than that of control group ［Mass action robust:（307 .86±24.22） fmol/mg;Scatchard:（306.71±27.96） fmol/mg］(P<0.01), but no s ignificant difference was found in the R0 of GR between the control and the ra ts 12 h after low-degree scalding ［Mass action robust: （285.19±16.62） fmol/ mg ; Scatchard: （296.64±16.06） fmol/mg］. The injection of anti-rat TNFα, IL-1β antibodies, α-MSH and KVP all prevented the decline of R0 of GR in h epatic cytoplasm in rats with severe scalding. Conclusion The injections of anti-rat TNFα, IL-1β antibodies, α-MSH or KPV can attenuate the reduction of GR in rat hepatic cytoplasm caused by severe scalding-induced pathological stress to some extent.
ABSTRACT
Objective To clone and identify the differentially expressed genes of rat intestinal epithelial cell line (IEC 6) before and after exposure to high dose radiation so as to provide proof for the investigation of the molecular mechanisms in the repair of radiation damage of intestinal epithelial cells. Methods A subtractive cDNA library for differentially expressed genes was constructed by suppression subtractive hybridization (SSH) and T/A cloning technique after IEC 6 cells were exposed to radiation at the dose of 35 Gy ? ray. The expressed sequence tag (EST) library was screened by reverse Northern hybridization. Positive clones were sequenced and the similarity was searched against the DNA database in GenBank. Limited clones were identified by Northern hybridization. Results More than 2 000 white clones were harvested after the library amplification. Ninety six of them were randomly picked out for PCR amplification, and 15 positive clones which corresponded to 12 individual genes were identified by reverse Northern hybridization. These genes were involved in cell skeleton, cell stress, cell cycle control, and signal transduction, etc. In addition, a novel cDNA sequence was also obtained. Conclusion A subtractive cDNA library for differentially expressed genes in IEC 6 cells exposed to the radiation at the dose of 35 Gy ? ray has been successfully constructed with SSH and T/A clone techniques. Several positive ESTs which correspond to genes involving in cell skeleton, cell stress, cell cycle control, and signal transduction are identified. These genes may play important roles in the process of the damage and repair of the intestinal epithelial cells exposed to radiation.
