CIRP Expression In Different Tissues Of Yak And The Effect Of Mild Cold Shock On The Celluar Expression Of CIRP And HSP70

This review focused on the roles of two major cold-inducible RNA binding proteins known in human cells: CIRP and RBM3. Both proteins were discovered when they were shown to be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. Initially, it was suggested that these proteins have a suppressive rather stimulatory effect on proliferation; however, proliferative and/or proto-oncogenic functions have recently been assigned to CIRP and RBM3. In a high throughput genetic screen, we recently identified CIRP as an immortalized gene in murine primary cells. On the other hand, the role of RBM3 in transformation has already been demonstrated. Interestingly, both CIRP and RBM3 have been found to be up-regulated in human tumors. This article highlights the roles of CIRP and RBM3 in tumorigenesis, and proposes a model by which CIRP might contribute to senescence bypass by counteracting the deleterious effects of oxidative damage.Compared to bacteria and plants, the cold shock response has attracted little attention in mammals except in some areas such as adaptive thermogenesis, cold tolerance, storage of cells and organs, and recently, treatment of brain damage and protein production. At the cellular level, some responses of mammalian cells are similar to microorganisms; cold stress changes the lipid composition of cellular membranes, and suppresses the rate of protein synthesis and cell proliferation. Although previous studies have mostly dealt with temperatures below 20?℃, mild hypothermia(32 ℃) can change the cell’s response to subsequent stresses as exemplified by APG-1, a member of the HSP110 family. Furthermore, 32?℃ induces expression of CIRP(cold-inducible RNAbinding protein), the first cold shock protein identified in mammalian cells, without recovery at 37?℃. Remniscent of HSP, CIRP is also expressed at 37?℃ and developmentary regulated, possibly working as an RNA chaperone. Mammalian cells are metabolically active at 32?℃ and cells may survive and respond to stresses with different strategies from those at 37?℃. Cellular and molecular biology of mammalian cells at 32?℃ is a new area expected to have considerable implications for medical sciences and possibly biotechnology.(1)Adaptation to hypothermia is regulated by Cold-inducible RNA binding protein(CIRP). The CIRP gene is generally expressed in various tissues; specially it is over expressed during cold and many other stresses. How animals living on Qinghai-Tibetan plateau adapt to the extreme hypoxia, hypothermia and strong UV radiation environment is known indistinctly. In this study, In this study, the Qinghai adult yak which has been living at 3000–5000 m altitude was selected as the model of plateau adaptation species. The CIRP ORF(open reading frame) encoding had been cloned from the domestic yak brain. The expression of CIRP was analyzed at both m RNA and protein levels in various tissues. Furthermore, the high expression of CIRP protein in the heart, brain, testis, skin and lowest in the lung may provide the new data to understand the important role of CIRP protein in the plateau adaptation of the domestic yak on long-term evolution.(2)Among a significant number of described cold shock proteins, CIRP(cold-inducible RNA binding protein) has been widely researched. In order to explore the function of CIRP in the development of yak testes,and further provide datas for elucidating the regulatory mechanism by which of CIRP acts in spermatogenesis and testicular founction of plateau mammalian. We investigated the dynamic expression of CIRP in yak testis during postnatal development by means of real-time RT-PCR, western blots and its cellular localization by the immunohistochemical SABC method. In this study, whole testes were collected from 1-day-old, 5-month-old, 1-year-old and 3-year-old male yaks. The results showed yak CIRP open reading frame contained 642 bp, encoded for 213 amino acids and their molecular weight was estimated as 23 k Da. The c DNA sequences of yak CIRP revealed significant homology of 99.8% with Bos Taurus. The real-time RT-PCR and western blots showed that CIRP m RNA and protein was expressed in testes of yak from each developmental group, and increased with age. The immunostaining of CIRP were weakly expressed in the seminiferous tubules and occurred in the spermatogonium of 1-day-old yak testes. Then the immunostaining of CIRP was widely localized in the spermatogonium of 5-month-old and. And in 1-year-old yak testes, primary spermatocyte was observed and positive substances were spermatogonium and primary spermatocyte. Additionally, in 3-year-old yak testes which developed well, the strongly expression of CIRP was observed in seminiferous tubules, and the positive immunostaining occurred in nucleus of spermatogonium and primary spermatocyte. Our fidings suggest that CIRP may play an important role in regulating testicular development and maintaining the proliferation and differentiation of spermatogenic cells.(3)The cellular effects of hypothermia has been recognized a complex process including a stress response to cold and subsequent rewarming. In this study, real-time fluorescence quantitative PCR and western-blot techniques were used to observe the dynamic expression of CIRP, HSP70 and P53 in the yak ovarian granulosa cells. And cells were exposed at 25 ℃ for 5 d and rewarmed at 37 ℃ for 24 h. The results showed that hypothermia and subsequent rewarming affected cell biology and induced a cellular stress response. The expression of CIRP was increased at 25 ℃ already at day 1 and returned to basal level upon rewarming after 24 h. While the expression of HSP70 was gradually increased upon rewarming at 37 ℃, maximal expression was occurred at 8 h after rewarming and followed by a the expression of CIRP m RNA and protein was increased upon exposure to hypothermia, and a process that accompanied a maximal expression of CIRP and HSP70 m RNA, suggested that the expression of CIRP m RNA and protein was increased upon exposure to hypothermia, and decline. Moreover the maximal expression of P53 was appeared at 4 h after rewarming and followed by a decline. Additionally, the observation that P53 m RNA was significantly decreased, a process that accompanied a maximal expression of CIRP and HSP70 m RNA, suggested that the expression of CIRP m RNA and protein was increased upon exposure to hypothermia, and HSP70 was induced upon rewarming. Overall, the CIRP and HSP70 were shown to play a role in protecting cells from the deleteriou effects of stress and apoptosis. These findings would bring new insights into the potential beneficial effects of mild hypothermia and rewarming used in various research and therapeutical fields.