Gene and protein expressions of p28GANK in rat with liver regeneration.
OBJECTIVE
To observe the gene and protein expression changes of p28GANK in regenerating liver tissues, and to reveal the biological function of p28GANK on the regulation of liver regeneration.


METHODS
One hundred and thirty two adult male Sprague-Dawley rats were selected, weighing 200-250 g, and divided randomly into sham operation (SO) group and partial hepatectomy (PH) group. Each group had eleven time points: 0, 2, 6, 12, 24, 30, 48, 72, 120, 168 and 240 h, six rats were in each time point. The rats were undergone 70% PH under methoxyflurane anesthesia by resection of the anterior and left lateral lobes of the liver. SO was conducted by laparotomy plus slight mobilization of the liver without resection. Liver specimens were collected at the indicated time points after PH or SO. The expression level of p28GANK mRNA was determined by Northern blot as well as at protein level via immunohistochemical staining. The expressions of p28GANK mRNA in these tissues were analyzed by imaging analysis system of FLA-2000 FUJIFILM and one way analysis of variance. The protein expressions of p28GANK in these tissues were analyzed with Fromowitz' method and Rank sum test.


RESULTS
The expression of p28GANK mRNA in the regenerating liver tissues possessed two transcripts, which were 1.5 kb and 1.0 kb. There was a significantly different expression patterns of p28GANK mRNA between SO and PH groups (P<0.01). The expression of p28GANK mRNA increased 2 h after PH, the peak time was 72 h (SO group: 163.83+/-1.4720; PH group: 510.5+/-17.0499, P<0.01). There was a significant difference in the 1.5 kb transcript, which decreased gradually after 72 hours. The protein expression of p28GANK was mainly in the cytoplasm of regenerating hepatocytes, and increased near the central region 24 h after PH, and became strongly positive at 48 h (+++, vs the other time points P<0.05), but decreased 72 h after PH.


CONCLUSIONS
The expression of p28GANK mRNA increases in the early stage of rat liver regeneration, the protein expression of p28GANK is mainly in the cytoplasm of regenerating liver cells. It suggests that the gene of p28GANK may be an important regulatory and controlled factor involved in hepatocyte proliferation during liver regeneration.
Qin
Jian-Min
JM
International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China.
Fu
Xiao-Yong
XY
Li
Shen-Jing
SJ
Liu
Shu-Qin
SQ
Zeng
Jin-Zhang
JZ
Qiu
Xiu-Hua
XH
Wu
Meng-Chao
MC
Wang
Hong-Yang
HY
D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D022781:Hepatocytes / Q000502:physiology; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D015513:Oncogene Proteins; C403591:PSMD10 protein, human; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D046988:Proteasome Endopeptidase Complex