[Effects of antisense p38 α mitogen-activated protein kinase on myocardial cells exposed to hypoxia and burn serum].
OBJECTIVE
To study the effects of antisense p38α mitogen-activated protein kinase (hereinafter referred to as p38α) on myocardial cells exposed to hypoxia and burn serum.


METHODS
Thirty adult SD rats were inflicted with 40% TBSA full-thickness burn on the back to obtain burn serum. The myocardial cells were isolated from 80 neonatal SD rats and cultured, then they were divided into 4 groups according to the random number table: normal control group (N, ordinary culture without any treatment), hypoxia+burn serum group (HB, exposed to hypoxia after being treated with 10% burn rat serum), hypoxia+burn serum+infection group (HBI, exposed to hypoxia and 10% burn rat serum after being infected with antisense p38α gene-carrying adenovirus), hypoxia+burn serum+empty vector infection group (exposed to hypoxia and 10% burn rat serum after being infected with adenovirus empty vector). At post hypoxia hour (PHH) 1, 3, 6, and 12, mRNA and protein expression levels of p38α in the latter 3 groups were determined by RT-PCR and Western blotting, cell viability was determined by methylthianolyldiphenyl-tetrazolium bromide assay, and lactate dehydrogenase (LDH) activity was assayed at the same time point. At PHH 1, 6, and 12, apoptosis rate of myocardial cells was assessed by annexin V staining method. The indexes of group N were determined with the methods mentioned-above. Three wells were set at each time point in each group. Data were processed with one-way analysis of variance and LSD- t test.


RESULTS
(1) At PHH 1, 3, and 6, the p38α mRNA level was higher in group HB than in group N and group HBI (with t values from 2.725 to 4.375, P values all below 0.05). (2) At PHH 1, 3, and 6, the p38α protein level was higher in group HB than those in group N and group HBI (with t values from 5.351 to 7.981, P values all below 0.01). (3) At PHH 3, 6, and 12, the cell viability in group HB (0.115 ± 0.007, 0.104 ± 0.006, 0.094 ± 0.005) was lower than that in group N (0.141 ± 0.014) and group HBI (0.136 ± 0.009, 0.124 ± 0.010, 0.112 ± 0.007, with t values from 2.357 to 6.812, P values all below 0.05). (4) The LDH activity was up-regulated in group HB as compared with that in group N and group HBI at each time point (with t values from 22.753 to 201.273, P values all below 0.01). (5) At PHH 1, 6, and 12, the apoptosis rate of myocardial cells in group HB [(5.4 ± 0.7)%, (8.7 ± 1.1)%, (13.6 ± 1.7)%] was higher than that of group N [(3.1 ± 0.3)%] and group HBI [(4.3 ± 0.5)%, (5.1 ± 0.7)%, (7.2 ± 0.9)%, with t values from 2.345 to 9.700, P < 0.05 or P < 0.01].


CONCLUSIONS
Antisense p38α can protect the myocardial cells from the injury of hypoxia and burn serum.
Department of Burns and Plastic Surgery, the First Affiliated Hospital of the University of South China, Hengyang 421001, China.
Jun
J
Zheng
Yue-sheng
YS
Huang
Xiao-yuan
XY
Huang
Peng-ju
PJ
Fan
Wei-feng
WF
He
Xiao-rong
XR
Zhang
D000818:Animals; D016375:Antisense Elements (Genetics) / Q000235:genetics*; D017209:Apoptosis; D015687:Cell Hypoxia; D002478:Cells, Cultured; D005260:Female; D008297:Male; D048308:Mitogen-Activated Protein Kinase 14 / Q000235:genetics* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044967:Serum; D014162:Transfection
D016375:Antisense Elements (Genetics); D048308:Mitogen-Activated Protein Kinase 14