Effect of low temperatures on BAX and BCL2 proteins in rats with spinal cord ischemia reperfusion injury

Abstract

ABSTRACT. We evaluated changes in BAX and BCL2 expression levels after spinal cord ischemia/reperfusion injury (SCII) and hypothermia during operations in rats. Eighty rats were divided into four groups: Group A (N = 20, 18°C); Group B (N = 20, 28°C); Group C (N = 20, room temperature); and Group D (N = 20, sham operation control). Spinal cord ischemia was induced for 90 min. Hypothermia was induced 15 min before, and maintained during ischemia, followed by heating to normothermia for 30 min after reperfusion. Motor function of the lower limbs was evaluated according to the Tarlov score at 72 and 168 h. For each rat, spinal cord samples were taken at 6, 24, 72 h, and 1 week to evaluate the histopathological changes, neuronal 10491 BAX and BCL2 in spinal cord ischemia reperfusion injury rats ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 10490-10499 (2015) apoptosis, and BAX and BCL2 expression levels. Compared with normothermia, hypothermia significantly improved hind limb function; Group B achieved a higher score than Group A. Group D showed no neurologic deficiency, while the other groups showed various degrees. Group C exhibited greater neuronal apoptosis, higher BAX expression, but lower BCL2 expression than the other groups. Compared with Group A, BAX was expressed less and BCL2 more in Group B, and there was less apoptosis in Group B. Hypothermia preserves hind limb motor function and reduces neuronal death, thereby protecting rats from SCII. The spinal cord may be protected from SCII by inhibition of BAX and activation of BCL2. However, deep hypothermia may inhibit the expression of BCL2, resulting in a worse outcome than mild hypothermia.

Hypothermia protects retinal ganglion cells against hypoxia‐induced cell death in a retina organ culture model

“…Hypothermia thus might attenuate hypoxia‐induced apoptosis and therefore apoptotic markers were increased in retinal explants treated with 30°C of hypothermia, whereas 20°C hypothermia has a stronger neuroprotective effect than 30°C and might not only attenuate but suspend apoptosis. Again, this effect was also found in a spinal cord ischemia reperfusion injury study …”

“…Again, this effect was also found in a spinal cord ischemia reperfusion injury study. 40 The neuroprotective effect of hypothermia was also visible under normoxic control conditions. The neuronal marker Thy1 was significantly increased and the apoptotic Bax/Bcl-2 mRNA ratio was decreased in retinal explants treated only with hypothermia of 20 C compared to standard culture conditions of 37 C. Taken together, hypothermia is a potent protection against retinal hypoxia, defending the hypoxiatreated retinal explants against retinal thinning, decreased RGC survival, increased RGC death, gliosis and loss of spontaneous RGC activity.…”

Dexmedetomidine attenuates spinal cord ischemia–reperfusion injury through both anti-inflammation and anti-apoptosis mechanisms in rabbits

“…Spinal cord I/R injury occurs in up to one-fifth of high-risk patients [ 2 ]. Although there are some potential measures that have shown promise (such as controlled hypothermia and hyperbaric oxygen therapy) [ 3 , 4 ], there is an urgent need to develop further neuroprotective strategies to target this devastating complication.…”

Targeting the blood-spinal cord barrier: A therapeutic approach to spinal cord protection against ischemia-reperfusion injury

“…Thus, low temperature has a protective effect on SCIRI, as has been reported in rat model [26,27]. Recently, Zhu et al [28] showed that hypothermia treatment can reduce neurons apoptosis and improve locomotion function after spinal cord ischemia injury in rats, and mechanisms underlying these effects are associated with the inhibition of the expression of Bcl-2 associated X (BAX) protein and the activation of B-cell lymphoma-2 (Bcl-2) protein, both crucial plyers Bcl-2 in cell apoptosis. It has been reported that low temperature treatment can protect the integrity of the BSCB.…”