Résumé
ObjectiveTo investigate the expression and role of response gene to complement 32 （RGC32） in liver regeneration after partial hepatectomy （PH）. MethodsA total of 42 male C57BL/6 mice， aged 10 weeks， were randomly divided into control group， postoperative day 1 group （1－d group）， postoperative day 2 group （2－d group）， postoperative day 4 group （4－d group）， postoperative day 6 group （6－d group）， postoperative day 8 group （8－d group）， and postoperative day 10 group （10－d group）， with 6 mice in each group. In the control group， the complete liver of the mice was resected for weighing and photography as the normal control group （sham group）； further， the left and middle lobes of the liver were resected for weighing and photography as the surgical control group （0－day group）； the sham group and the 0－day group shared the same group of mice. After successful modeling by PH， the mice were sacrificed on days 1， 2， 4， 6， 8， and 10 after surgery， and the liver was collected to measure the change in size. HE staining and oil red O staining were used to evaluate liver histomorphological changes； serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were measured to evaluate the changes in liver function； immunohistochemical staining was used to measure the expression of proliferating cell nuclear antigen （PCNA） and Ki67 and analyze the change in cell proliferation during liver regeneration； quantitatie real－time PCR and immunohistochemical staining were uused to measure the expression and subcellular distribution of RGC32 during liver regeneration； EdU cell proliferation assay was used to analyze the effect of RGC32 overexpression or knocknout on hepatocyte proliferation in L02 cells. For continuous data， comparison between multiple groups was made by analysis of variance， and further pairwise comparisons were conducted using the LSD－t test. The independent samples t－test was used for comparison of continuous data between two groups. A Pearson correlation analysis was performed. ResultsThe liver gradually enlarged after PH， and the liver/body weight ratio rose to the peak from days 0 to 6， with significant differences between different time points （all P<0.05）， while there was no significant change in liver size from days 6 to 10. The number of liver lipid droplets significantly increased after PH surgery and gradually decreased with liver regeneration， with a significant difference between the portal vein region and the central vein region （all P<0.05）. Compared with the sham group， the 1d group had significant increases in the serum levels of ALT and AST （all P<0.05）， which gradually returned to the levels of the sham group on day 6 and day 2 after surgery， respectively （P>0.05）. Immunohistochemical staining showed that there were rapid increases in the numbers of PCNA－ and Ki67－positive liver parenchymal cells after PH surgery， with the highest numbers of 86±5 and 89±5， respectively， on day 2， which then gradually decreased； however， there were gradual increases in the numbers of PCNA－ and Ki67－positive nonparenchymal cells， with the peak numbers of 34±5 and 25±3， respectively， on day 6， which then gradually decreased. The total expression of RGC32 increased to the highest level on day 2 after PH surgery and then gradually decreased， and the changing trend of RGC32 expression in cytoplasm was consistent with that of total RGC32 expression； however， the expression of RGC32 in nucleus decreased to the lowest level on day 2 after PH surgery and then increased gradually. The correlation analysis showed that the expression of RGC32 in nucleus was negatively correlated with the proliferation of liver parenchymal cells （R2=0.308 3， P=0.016 7）， and the expression of RGC32 in cytoplasm was positively correlated with the proliferation of liver parenchymal cells （R2=0.808 6， P<0.000 1）. Cell experiments showed that compared with the control group， the EdU－positive rate was reduced by 15.6% after RGC32 overexpression （P<0.01） and was increased by 19.2% after RGC32 knockdown （P<0.01）. ConclusionLiver parenchymal cells and nonparenchymal cells show asynchronous proliferation and participate in liver regeneration together. During liver regeneration after hepatectomy， there are differences in the expression of RGC32 between nucleus and cytoplasm， and RGC32 in nucleus may inhibit hepatocyte proliferation.
Résumé
Response gene to complement 32(RGC-32)as an important response gene to complement was widely expressed in a lot of tissues and organs and participated in many biological processes such as cell proliferation and differentiation, cell cycle regulation, inflammation, immune regulation, and tumor, etc.As a cell cycle regulator, RGC-32 affected the development of numerous diseases by regulating the cell cycle.In recent years, many studies have shown that RGC-32 may be involved in the renal tubular injury and repair, and its role in the renal tubular injury and repair may be related to its regulation of cell cycle especially the G2/M.This article will make a brief review on the progress of the mechanism of RGC-32 regulating the renal injury and repair.
Résumé
Response gene to complement 32 (RGC-32) as an important response gene to complement was widely expressed in a lot of tissues and organs and participated in many biological processes such as cell proliferation and differentiation,cell cycle regulation,inflammation,immune regulation,and tumor,etc.As a cell cycle regulator,RGC-32 affected the development of numerous diseases by regulating the cell cycle.In recent years,many studies have shown that RGC-32 may be involved in the renal tubular injury and repair,and its role in the renal tubular injury and repair may be related to its regulation of cell cycle especially the G2/M.This article will make a brief review on the progress of the mechanism of RGC-32 regulating the renal injury and repair.
Résumé
As one of the important response gene to complement,response gene to complement-32 (RGC-32) simultaneously involves in many other biological functions.Recent studies have shown that RGC-32 was one of the critical regulatory factors at the G2/M check point in the cell cycles and involved in the cell cycle regulation.The expression products of RGC-32 gene play the key roles in cell proliferation,differentiation,inflammation,tumor metastasis and other processes.However,it has not been clarified in its biological mechanisms of regulation in cell cycle.This article takes a brief review about RGC-32 on its gene structure,biological functions,regulation of cell cycle,and the relationship of cell cycle regulation which involves in RGC-32.
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Objective To investigate the expression of RGC32 gene in pulmonary adenocarcinoma tissue and to explore the influence on proliferation and apoptosis of A549 cells.Methods Real-time PCR was applied to detect the expression of RGC32 gene in 36 cases of pulmonary adenocarcinoma and pericancerous tissues.RNA interference was used to inhibit the expression of RGC32 gene.After RNA interference,the expression of RGC32 gene was detected by real-time PCR,the apoptosis of the transfected cells was detected by flow cytometry and the inhibition ratio of cell proliferation was detected by methyl thiazolyl tetrazolium (MTT).Results The expression of RGC32 gene was upgraded in pulmonary adenocarcinomas tissues(1:2.2736,t=-29.185,P=0.01).After RNA interference,the expression of RGC32 gene transfected A549 cells was down-regulated significantly[(2.47±0.17)％ vs(4.65±0.26)％,t=-202.868,P=0.000].Comparing to the control cells,the apoptosis of experimental group cells increased significantly (2.9 ％ vs 45.4 ％,t=-37.915,P=0.01),and the inhibition ratio of cell proliferation increased significantly.Conclusion The expression of RGC32 gene shows an obvious upgraded in pulmonary adenocarcinoma.The low expression of RGC32 gene can induce apoptosis and inhibit proliferation of A549 cells.
Résumé
Response gene to complement-32(RGC-32)as one of important response genes to complement,involves in many biological functions. Recent studies found that many factors could induce the expression of RGC-32 such as membrane attack complex,cortical hormones,growth factors, luteinizing hormone and transforming growth factor-β and so on. The expression products of RGC-32 play a key role in cell proliferation, differentiation, inflammation, tumor metastasis and other processes, thus to participate in the occurrence of many diseases' development processes. However, it has not be clarified in its exact cell biological function, subcellular localization, gene regulation mechanism. This article will make a brief review on gene structure, functions and roles in cell biology as well as the relationship between human diseases for RGC-32.