Endoplasmic reticulum stress induced by tunicamycin and antagonistic effect of Tiantai No.1 (1) on mesenchymal stem cells.
OBJECTIVE
Changes of the internal and external cellular environments can induce calcium homeostasis disorder and unfolded protein aggregation in the endoplasmic reticulum (ER). This ER function disorder is called endoplasmic reticulum stress (ERS). Severe long-term ERS can trigger the ER apoptosis signaling pathway, resulting in cell apoptosis and organism injury. Recent researches revealed that ERS-induced cell death was involved in the neurocyte retrogradation in the progress of neuron degenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease and so on. Therefore, the protection effect of the traditional Chinese drug-Tiantai No. 1 (1) on the ERS injury of AD was investigated at the molecular gene level in this study with a view to explore the gene pharmacodynamic actions and mechanisms of this drug.


METHODS
Primarily cultured marrow mesenchymal stem cells (MSCs) of rats were treated by tunicamycin (TM) in order to induce ERS. RT-PCR, fluorescence immunocytochemistry and Western blot techniques were used to determine the mRNA and protein expression levels of the protective stress protein-ER molecular chaperones GRP78 and GRP94 (which would assist cells to resist cellular stress injury), and to determine the mRNA and protein expression levels of apoptosis promoting molecule Caspase-12 on the membrane of the ER, respectively.


RESULTS
Protein expression levels of GRP78 and GRP94 were significantly increased in the TM-induced MSCs, and the mRNA level of Caspase-12 was also remarkably increased in the TM-induced MSCs (P<0.05). All these proved that the ERS model was successfully established by TM in MSC. Meanwhile, the mRNA and protein levels of GRP78 and GRP94 were all significantly increased compared with the model group (P<0.05 or P<0.01) after MSCs were treated with Tiantai No.1 while the mRNA and protein expression levels of Caspase-12 were significantly decreased compared with the model group (P<0.05 or P<0.01). This effect showed a dose dependent manner.


CONCLUSIONS
Tiantai No.1 might attenuate the cell apoptosis induced by ERS injury, and thus protect the neurons against AD.
Shenzhen Hospital of Southern Medical University, Shenzhen, Guangdong Province, 518033 China. zhengzhw@yahoo.com.cn
Zheng-zhi
ZZ
Wu
Ying-hong
YH
Li
Andrew C J
AC
Huang
Ming
M
Li
Xiao-li
XL
Zhang
Ji-guo
JG
Wang
Min
M
Yang
Man-yin
MY
Chen
D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002478:Cells, Cultured; D004336:Drug Antagonism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D005786:Gene Expression Regulation / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism; D012313:RNA / Q000032:analysis / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D014415:Tunicamycin / Q000037:antagonists & inhibitors* / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D004365:Drugs, Chinese Herbal; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D008562:Membrane Glycoproteins; C548800:Tiantai No.1; C053387:endoplasmin; D014415:Tunicamycin; D012313:RNA