SphK2 Participates In Hypoxic Preconditioning To Reduce The Expression Of Craniocerebral Trauma And The Effect Of Cranial Nerves In Rats

Traumatic Brain Injury(TBI)has a high mortality rate and morbidity rate.From light to heavy TBI,patients and their families are severely burdened with mental,emotional and cognitive burdens,causing huge losses to families and society.Until now,the prevention,diagnosis,treatment and rehabilitation of TBI have been the focus and difficulty of research in the field of neurosurgery worldwide.TBI is accompanied by local brain ischemia,hypoxia and the destruction of the blood brain barrier(BBB)that eventually leads to edema of the brain cells after injury.However,brain edema increases the severity of ischemia and hypoxia.,showing a vicious cycle.At present,people are eyebrows on nerve injury and other issues.The concept of ischemic preconditioning is of great significance in maintaining the complete permeability of BBB and the degree of brain cell edema,and the improvement of prognosis has been a topic in the field of neurosurgery at home and abroad.Key topics.At present,the mechanism of ischemic protection of brain tissue after nerve cell injury has not yet been overcome,and it is still in a stage of development.People are eager to overcome this worldwide problem.Hypoxic preconditioning(HPC)can be defined as: after giving a single or multiple hypoxic stimulation for a short period of time,it can stimulate its own protective effect in various tissues of the body,and it can protect the neuroprotective function against ischemia and hypoxia.Play a powerful role.HPC(past model of cerebral ischemia and hypoxia)plays an important role in the protection of neuronal cells,maintaining the integrity and permeability of the BBB and thus effectively reducing the degree of brain edema.Currently,HPC is in the TBI worldwide.After the intervention of the brain cell remodeling and protection mechanism is still in the research stage,there are few reports in the field of foreign specialist.Sphingosine kinase 1(Sph K1)is a key enzyme that catalyzes the conversion of sphingosine Sph to Sphingosine 1-phosphate(S1P).Sph K2 is known for its catalytic activity and cellularity.The special orientation affects the level of intracellular calcium,which plays a pivotal role in the extent of neuronal apoptosis.At the same time,it may play an expression role in the nervous system and mature in the central nervous system.After brain injury,The up-regulation of expression exerts a cushion effect on brain nerve cell damage [1].The relevant experiments in this study were designed to investigate the effect of hypoxic preconditioning(HPC)on the expression of Sph K2 in brain tissue of rats with traumatic brain injury and its effect on neuronal apoptosis,and to explore the effect of HPC on traumatic brain tissue repair.The mechanism of neuronal apoptosis and the effect of BBB permeability.Part I Experimental Study on the Changes of Sph K2 Expression and the Changes of Blood-brain Barrier Permeability in Rats with Traumatic Brain InjuryObjective To investigate the changes of sphingosine kinase-2 expression and blood brain barrier(BBB)in brain tissue of rats with traumatic brain injury.Method One hundred and eight rats(adult male Sprague-Dawley rats)were randomly divided into a traumatic brain injury group(TBI group n=96)and a control group(Con group n=12),which were established using a modified Feeney’s free-fall method.Rat traumatic brain injury(TBI)model was used as a control group.The TBI group was decapitated at 1h,4h,8h,12 h,24h,3d,7d,and 14 d after injury.Reverse transcription-polymerase chain reaction(RT-PCR),western blot,and immunohistochemistry were used to detect the changes of sphingosine kinase 2 expression in the cerebral cortex of each group of rats in the contused area.The wet and dry weight method was used to measure the brain tissue water content and immunity.The change of blood-brain barrier permeability was detected by histochemical Ig G method.Results RT-PCR results: Expression of Sph K2 m RNA began to increase 1 h after TBI,rose to its highest point 1 d,followed by a descending phase(3 days),and then decreased to a normal level(difference afterwards)(difference)(difference)Statistically significant);Sph K2 immunohistochemical staining results: Brain tissue was immediately stained after the TBI was impaired(some of the colors were tan),and the extravascular space network was observed under a high power microscope.Fiber network)The yellow staining of Ig G was obvious.The peak of yellow staining appeared from the beginning of yellow staining to 12 hours,but the duration was short.At the same time,the Ig G staining of neurons and glial cells was positive.After 1 day,the Ig G staining range was reduced.After 14 days,a few Ig G stains were still seen in some sections;Western-Blotting method was used to detect the Sph K2 protein results: the expression began to increase immediately after the injury of rat brain tissue(1 h)and began to increase.There was also a peak period(12h)and finally a recovery period(14 days)(the difference was not statistically significant).Conclusion Sphingosine kinase 2 plays an important role in the preservation of BBB integrity after trauma,and its mechanism is still in its infancy.Its mechanism may involve sphingosine kinase 2 mediating endothelial differentiation-dependent gene-dependent actin cytoskeleton rearrangement.To enhance the integrity of the endothelial cell barrier,to maintain the integrity of the BBB to further ease the occurrence of edema in the damaged brain tissue.part II Sph K2 participates in hypoxic preconditioning to reduce the expression changes and neuronal apoptosis after traumatic brain injury in ratsObjective To analyze the expression of sphingosine kinase 2(Sph K2)protein and gene and the detection methods of Ig G in the injured brain injury group(HPC group)in the injured brain injury group(TBI group).Effect of Hypoxic Preconditioning on Neuronal Apoptosis Following Traumatic Brain Injury in Rats.Methods A total of 204 healthy adult(SD)rats weighing approximately 260-290 g were purchased from the Experimental Animal Center of Anhui Medical University.The rats were all healthy adult rats(according to the hair).Judgment),carefully reared according to scientific standards,timing,set meals,quantitative feeding water,rat living environment for our hospital laboratory multi-layer iron cage device,maintaining indoor ventilation while maintaining the room temperature range between 23-25 °C.Rats were divided into 96 craniocerebral trauma groups(HPC group)and 96 craniocerebral trauma groups(TBI group)and 12 control groups(Con group)by random number method.The HPC group and TBI group were At 1h,4h,8h,12 h,1d,3d,7d,14 d after injury,there were 8 subgroups,12 in each subgroup.A modified TEE model was developed using the improved Feeney’s method(same as above).Sph K2 gene and protein were detected by Ig G immunohistochemical staining,real-time quantitative polymerase chain reaction(RT-PCR)and Western Blotting methods.The expression of neurocyte apoptosis was detected by TUNEL staining.Results(1)Normal brain tissue(control group)showed no staining of Ig G.Ig G-stained positive cells were seen 1 hour after TBI.Twelve-hour Ig G staining was very severe.The expression gradually decreased at the following 12 hours.The difference between the two groups was statistical group.Significance(P<0.05).(2)The results of RT-PCR and Western Blotting showed that the expression of Sph K-2 gradually increased at 3 hours after traumatic brain injury,peaked at 24 hours,decreased after 3-14 days,and Sph K2 protein at 6-7 days.The degree of HPC expression was significantly more than that of TBI group(the difference was statistically significant(P<0.05)).(3)Apoptosis of nerve cells detected by TUNEL staining showed that apoptotic cells began to express at 6 hours after craniocerebral injury in TBI group and HPC group,apoptotic cells grew gradually at 12 to 24 hours,and reached a maximum after 3 days.After 14 days of normalization,the number of apoptotic neurons in the HPC group and TBI 12 to 7 days after injury was found to be significantly lower in the HPC group,and there was a statistically significant difference(P<0.05).Conclusion(1)HPC can effectively reduce neuronal cell injury after traumatic brain injury in rats.The expression of Sph K2 significantly increases the ability of cerebral cells to undergo ischemia and hypoxia,and it can effectively protect neurons.(2)Hypoxia Preconditioning can reduce the damage of cranial nerves by promoting the expression of Sph K2 after brain injury in rats,and it can reduce the apoptosis of nerve cells to a great extent.It has a close relationship with the survival and function of brain cells after injury.