Identification of specific peptide ligands for B-lymphoma cell and its effect on tyrosine phosphorylation and cell apoptosis / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To search novel method for diagnosis and therapy of B-lymphoma, specific small molecular peptide ligands against binding site of tumor cells were screened and its effects on signal transduction and cell apoptosis were tested.</p><p><b>METHODS</b>Specific peptide ligands were screened by binding with site of human B lymphoma cell (OC1LY8) using peptide-bead libraries. The identified peptides were characterized with responsible cells by rebinding test. The role of tyrosine phosphorylation of peptide ligand was tested by Western blot; and its apoptosispromoting role was observed by confocal fluorescent microscope.</p><p><b>RESULTS</b>Specific peptide ligand was able to bind specifically to site on cell surface and enter into cytoplasm. Tetrameric peptide ligand was able to strongly trigger signal transduction resulting in tyrosine phosphorylation and cellular apoptosis in OC1LY8 cell line.</p><p><b>CONCLUSION</b>Screened peptide ligand can effectively bind with OC1LY8 cell, stimulate cellular tyrosine phosphorylation and induce cellular apoptosis.</p>

Effects of nuclear translocation of tissue transglutaminase and the release of cytochrome C on hepatocyte apoptosis / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To assess the effects of nuclear translocation of tissue transglutaminase (TTG) and the release of cytochrome C on hepatocyte apoptosis and to reveal the mechanism of signal transduction of early apoptosis in injured hepatocytes.</p><p><b>METHODS</b>Hepatocytes isolated from tissue transglutaminase gene knock-out mice and rats were stimulated with ethanol. Proteins from whole cell, cytoplasm and nuclei were extracted for determination of TTG activity by (14)C-putrescine incorporation. Distribution of TTG throughout the entire cell, as well as just nucleus was observed under a confocal scanning microscope. The amount of cytochrome C released from mitochondria was determined by ELISA. Cell apoptosis was observed by fluorescent cytochemistry.</p><p><b>RESULTS</b>TTG activity in whole cells and nuclei was significantly increased after the hepatocytes were treated with ethanol. Cytochrome C release was remarkably increased in the cells isolated from rat and wild-type mouse after treatment with ethanol but not in TTG gene knock-out mice. Cellular apoptosis appeared in hepatocytes isolated from rats and wild-type mice but not in the hepatocytes from TTG gene knock-out mice after stimulation with ethanol.</p><p><b>CONCLUSIONS</b>Increased TTG in hepatocytes can be translocated into the nucleus and promote release of mitochondrial cytochrome C into the cytoplasm. Passing through a series of signal pathways, hepatocyte apoptosis is induced eventually.</p>

Effects of type Ⅳ collagen,MMP-9 and TIMP-1 gene expression on the initiation of early phase radiation pulmonary fibrosis / 解放军医学杂志

Objective To investigate the gene expression profiles of type Ⅳ collagen, matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) at the onset of radiation pulmonary fibrosis, so as to explore their possible roles in the pathogenesis of pulmonary radiation injury. Methods The whole lung was irradiated with 20Gy of 60Co ?-ray in C57 mice. At 1, 2 and 4 weeks after irradiation, both irradiated mice and corresponding number of normal control mice were sacrificed. Alterations in mRNA transcription of type Ⅳ collagen, MMP-9 and TIMP-1 were observed by RT-PCR at different time points post-irradiation. The mean optical density of electrophoretic bands was measured and analyzed by image analyzer. Result The mRNA expression of type Ⅳ collagen was up-regulated gradually after irradiation with the passage of time. The mean optical density of electrophoretic band was 0.202 at 1 week post irradiation and reached its peak value (0.340) at 4 weeks post irradiation; the mRNA expression of MMP-9 was up-regulated significantly and reached its peak value (0.730) at 1 week post irradiation. It began to lower at 2 weeks (0.592). The mRNA transcription of TIMP-1 began to increase slightly 1 and 2 weeks post irradiation (0.987) and reached its peak value (2.027) at 4 weeks post irradiation. Conclusion 60Co ?-ray can stimulate mRNA expression of type Ⅳ collagen, MMP-9 and TIMP-1 with different profiles at different time points. Complex interactions among them may result in early tissue remodeling after pulmonary radiation injury, and it bears close relation with subsequent pulmonary fibrosis.

Characteristics and implication of MMP-12 expression during the course of development of radiation pulmonary injuries / 解放军医学杂志

Objective To observe the dynamic changes in matrix metalloproteinase-12(MMP-12) expression during the course of development of radiation pulmonary injuries in order to get an insight of the roles played by MMP-12 during early tissue remodeling after radiation pulmonary injuries.Methods Twenty-four Wistar rats were randomly assigned into four groups(6 each): normal control group and 1,2 and 4 weeks after irradiation groups.The rats in the last three groups received irradiation of the whole lung with 20Gy of 60Co ?-ray,and they were sacrificed 1,2 and 4 weeks post irradiation.The gene expression of MMP-12 was determined by RT-PCR;the protein expression was detected by Western blot;MMP-12 activity was examined by gelatin zymography;the tissue distribution of MMP-12 was observed by immunohistochemistry;the degradation and collapse of elastin were observed after tissue elastin specific staining.Results The gene expression of MMP-12 began to increase 1 week post irradiation,then decreased at 2 weeks,and it reached its peak value at 4 weeks,while its protein expression was elevated again 2 weeks post irradiation.MMP-12 was mainly expressed in macrophages and activated fibroblasts of the alveolar septum.With the elapse of time,the lung injury aggravated gradually,with thickening of alveolar wall and septum,breakdown of the structure of alveoli,collapss of a part of the alveolar space,extensive breakdown of elastin in the basement membrane of lung,appearing as irregular fibrils distributed in the lung.Conclusion 60Co ?-ray irradiation can up-regulate the expression of gene and protein of MMP-12 significantly,implying that it may play a very important role in early remodeling process in of radiation pulmonary injuries,and initiate the process of pulmonary remodeling by degrading elastin and destroying the normal structure of basement membrane.

The role of Kupffer cells in modulation of hepatic regeneration / 解放军医学杂志

Objective To approach the role of Kupffer cell (KC) in regulation of liver regeneration after partial hepatectomy (PH). Methods Condition medium of kupffer cells (KCCM) was prepared and the role of KCCM in promoting rat primary hepatocytes proliferation was observed by MTT method. The PH animal model was reproduced in mice and the rate of liver regeneration was measured and the expression features of TNF-?, TGF-? and TGF-?_1 were determined by immunohistochemical methods after PH with KC depletion. Results KCCM could promote primary hepatocyte proliferation significantly (A=0.746?0.06) compared with control (A=0.536?0.06, P

Significance of inhibitory effect of augmenter of liver regeneration on expression of TGF-?_1 in nonparenchymal cells of liver / 解放军医学杂志

Objective To Investigate the mechanism of augmenter of liver regeneration (ALR) in promoting proliferation of damaged hepatocyte. Methods The inhibitory effects of ALR on the expression of TGF-?_1 in hepatic stellate cell and Kupffer cell were studied by immunohistochemistry and Western blot. The effects of hepatic stellate cell (Ito cell) conditioned medium (ICCM+) and Kupffer cell conditioned medium (KCCM+) prepared by treatment of using augmenter of liver regeneration (ALR) on damaged hepatocytes proliferation were studied by MTT. The antagonistical role of ALR on TGF-?_1, which inhibited damaged hepatocyte proliferation was investigated by MTT determination. Results Immunoreactive positive signal of TGF-?_1 in hepatic stellate cell and Kupffer cell stimulated by ALR were decreased. Immunolabeling of TGF-?_1 in hepatic stellate cell stimulated by ALR was weakened. The proliferation of damaged hepatocytes was increased significantly by administration of ICCM and KCCM. ALR could reverse the inhibitory role of TGF-?_1 on the proliferation of damaged hepatocyte. Conclusion ALR can promote proliferation of injured hepatocyte indirectly by inhibiting expression of TGF-?_1 in hepatic stellate cell and Kupffer cell.

Mechanisms of augmenter of liver regeneration in promoting damaged hepatocyte proliferation / 中国病理生理杂志

AIM: To investigate the mechanisms of augmenter of liver regeneration (ALR) in promoting damaged hepatocyte proliferation.METHODS: The effects of Kupffer cell condition medium (KCCM+) stimulated by ALR on damaged hepatocyte proliferation were studied by MTT. The localization of ALR binding to Kupffer cell membrane and in intact rat liver was studied by immunohistochemistry. The IL-6 expression in Kupffer cells stimulated with ALR was observed by immunohistochemistry. RESULTS: The proliferation of damaged hepatocytes stimulated with KCCM+ was increased significantly. ALR immunostaining particles in plasm of hepatocyte were found in intact liver. The rough immunostaining particles of ALR were seen on the surface of Kupffer cell membrane. Immunostaining particles of IL-6 in Kupffer cells induced by ALR increased. CONCLUSION: ALR promotes proliferation of damaged hepatocytes indirectly by stimulating Kupffer cells.

The role of calcitonin gene-related peptide (CGRP) in rats septic shock / 中国病理生理杂志

In order to investigate the pathogenetic role of CGRP in septic shock, the effect of extraneous CGRP on septic shock was observed on late septic shock model produced by cecal ligature and puncture (CLP) in rats. The results showed that plasma CGRP elevated significantly in septic shock rat (14.3?4.0 vs sham 5.5?1.8 pg/ml, P

Effects of matrix metalloproteinase-12 abnormal expression on the transformation of pulmonary fibroblasts in radiation damaged rats / 解放军医学杂志

Objective To observe the effects of over-expression of matrix metalloproteinase-12 (MMP-12) on the transformation of pulmonary fibroblasts in radiation damaged rats. Methods Thirty-two male Wistar rats (weighed 250-280g) were randomly assigned into control group and 1, 2 and 4 weeks after irradiation groups (8 each). The whole lungs of rats in irradiation groups were irradiated by 60 Co ?-ray at a dose of 20Gy, and the lung specimens were harvested 1, 2 and 4 weeks after radiation. The change of MMP-12 activity was detected by gelatin zymography, the degradation and collapse of elastic fibers were observed by tissue specific staining, the "cross talking" phenomenon between alveolar type Ⅱ cells and mesenchymal cells was observed by transmission electron microscopy, the content of TGF-?1 was determined by ELISA, and the expression of ?-smooth muscle actin (?-SMA) was examined by immunohistochemistry. Results MMP-12 activity began increasing 1 week after irradiation, and seemed to decrease 4 weeks after irradiation. Elastin, a part of the basement membrane of alveolar wall, began to degrade and collapse 1 week after radiation, and became worse 4 weeks after irradiation. The expressions of both TGF-?1 and ?-SMA were elevated gradually within 4 weeks after radiation. The "cross talking" phenomenon was found by electron microscopy between alveolar type Ⅱ cells and mesenchymal cells. Conclusions Increased activity of pulmonary MMP-12 has been found after radiation, which may promote the transformation of pulmonary fibroblasts by degrading elastin and ultimately initiate the pulmonary fibrosis.