Increased level of JNK (MAPK) enzyme in anuclear cell (platelet) under osmotic stress

Backgrounds: Mitogen-activated protein kinase (MAPK) enzymes, known only in eukaryotes,are an important family of protein kinases. These enzymes play a key role in regulating variouscellular processes from cell proliferation and survival to apoptosis, which are activated by avariety of stimuli such as mitogens, oxidative stress, heat shock, and osmotic stress.Materials and Methods: In the present study, platelets originating from the cytoplasm of bonemarrow megakaryocytes and lacking any nucleus during puberty, were subjected to osmoticstress under hypertonic (۱.۹% NaCl) and hypotonic (۰.۷% NaCl) environments. As a control,isotonic (۰.۹% NaCl) condition was used. All of them were incubated at ۳۷ for ۱۵ mins and ۲۴hrs. After lysis of platelet samples using ultrasound waves, the extracts of test and control cellswere prepared and used to measure the level of JNK enzyme using the ELISA technique.Results: The results showed the presence of JNK enzyme in platelets in spite of they lose theirnuclei in the mature stages. Meanwhile, the osmotic stress significantly increased the level ofJNK in platelets (p-value < ۰.۰۵).Conclusion: The study shows the presence of the JNK enzyme in platelets and its increasedlevel under osmotic stress despite the fact that they do not have nuclei and genomic DNA. Theyprobably contain pre-mRNAs encoding the JNK enzyme. The existing cytoplasmic pre-mRNAsare processed into mRNA due to platelet osmotic stress and eventually the JNK enzyme.

کلیدواژه ها:

JNK ، Platelet ، Osmotic Stress ، Gene Expression