Identification and characterization of human MIBP1 gene in glioma cell differentiation.

Malignant gliomas are the most common and lethal intracranial tumors; differentiation therapy is a promising candidate for their treatment. In order to reveal the mechanisms related to glioma differentiation, after confirming that differentiation was induced by sodium phenylbutyrate in SHG-44 human glioma cells, RNA arbitrary primer differential display was used to screen differentially expressed genes. One gene was found to be upregulated by differential display, and this was also confirmed by reverse northern blot and quantitative real-time PCR analysis. After it was cloned and sequenced, the 505-bp fragment was identified as the MIBP1 (c-myc intron-binding protein 1) gene, also named Hivep2/MBP-2/Schnurri-2. Quantitative real-time PCR analysis of 30 human tissue samples revealed that the expression of MIBP1 tended to decrease with increasing WHO grade and was significantly depressed in the high malignancy gliomas group (WHO grade IV). We cloned and sequenced the MIBP1 gene, which was accepted by GenBank as number DQ231041. Finally, transfection of MIBP1 in a reverse transcription vector into glioma cells inhibited cell growth, induced differentiation, and blocked the cell cycle. Here, we identify and describe the structure and function of a differentiation-related gene, human MIBP1, in human glioma.

The experimental study of miRNA in pituitary adenomas.

AIM: We investigated the differential miRNA expression in pituitary adenomas (both non-functioning and gonadotropin-secreting) and normal pituitaries. MATERIAL AND METHODS: RNA was extracted and purified from pituitary adenomas (10 non-functioning and 10 gonadotropin-secreting) and from two normal pituitary tissue samples. The samples were analyzed by miRNA microarray. Gene expression was measured using realtime RT-PCR with SYBR GREEN I. RESULTS: In non-functioning pituitary adenomas, 25 miRNA genes were up-regulated (six by over 5-fold) and 15 were down-regulated (six by more than 10-fold). miR-124a was the most up-regulated gene (38.58-fold), and miR-31 the most down-regulated gene (21.5-fold). In gonadotropin-secreting pituitary adenomas, 16 miRNA genes were up-regulated (six by over 4-fold) and 13 were down-regulated (seven by more than 10-fold). miR-10b was the most up-regulated gene (48.73-fold), and miR-503 the most down-regulated gene (39.8-fold). Five genes were up-regulated in both subtypes: miR-523, miR-10b, miR-520b, miR-422a, and miR-422b. The RT-PCR results were consistent with those of the gene chips. CONCLUSION: We established miRNA expression maps of non-functioning and gonadotropin-secreting pituitary adenomas. The most strongly differentially expressed genes were miR-124a and miR-31 in non-functioning pituitary adenomas, and miR-10b and miR-503 in gonadotropin-secreting pituitary adenomas.

Increased leakage of brain antigens after traumatic brain injury and effect of immune tolerance induced by cells on traumatic brain injury.

BACKGROUND: Although traumatic brain injury can lead to opening the blood-brain barrier and leaking of blood substances (including water) into brain tissue, few studies of brain antigens leaking into the blood and the pathways have been reported. Brain antigens result in damage to brain tissues by stimulating the immune system to produce anti-brain antibodies, but no treatment has been reported to reduce the production of anti-brain antibodies and protect the brain tissue. The aim of the study is to confirm the relationship between immune injury and arachnoid granulations following traumatic brain injury, and provide some new methods to inhibit the immune injury. METHODS: In part one, methylene blue was injected into the rabbits' cisterna magna after traumatic brain injury, and concentrations of methylene blue and tumor necrosis factor (TNF)-α in blood were detected to determine the permeability of arachnoid granulations. In part two, umbilical cord mesenchymal stem cells and immature dendritic cells were injected into veins, and concentrations of interleukin 1 (IL-1), IL-10, interferon (IFN)-γ, transforming growth factor (TGF)-ß, anti-brain antibodies (ABAb), and IL-12 were measured by ELISA on days 1, 3, 7, 14 and 21 after injury, and the numbers of leukocytes in the blood were counted. Twenty-one days after injury, expression of glutamate in brain tissue was determined by immunohistochemical staining, and neuronal degeneration was detected by H&E staining. RESULTS: In part one, blood concentrations of methylene blue and TNF-α in the traumatic brain injury group were higher than in the control group (P < 0.05). Concentrations of methylene blue and TNF-α in the trauma cerebrospinal fluid (CSF) injected group were higher than in the control cerebrospinal fluid injected group (P < 0.05). In part two, concentrations of IL-1, IFN-γ, ABAb, IL-12, expression of glutamate (Glu), neuronal degeneration and number of peripheral blood leukocytes were lower in the group with cell treatment compared to the control group. IL-10 and TGF-ß were elevated compared to the control group. CONCLUSIONS: Traumatic brain injury can lead to stronger arachnoid granulations (AGs) permeability; umbilical cord mesenchymal stem cells and immature dendritic cells can induce immune tolerance and reduce inflammation and anti-brain antibodies to protect the brain tissue.

Increased expression of EMMPRIN and VEGF in the rat brain after gamma irradiation.

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.

Increased CD133(+) cell infiltration in the rat brain following fluid percussion injury.

The prominin-1/CD133 epitope is expressed in undifferentiated cells. Studies have reported that craniocerebral trauma in animal models of fluid percussion injury induces production of a specific stem cell subgroup. It has been hypothesized that fluid percussion injury induces CD133(+) cell infiltration in the brain tissue. The present study established a traumatic brain injury model through fluid percussion injury. Immunohistochemical staining showed significantly increased CD133 antigen expression in the rat brain following injury. CD133(+) cells were mainly distributed in hippocampal CA1-3 regions, as well as the dentate gyrus and hilus, of the lesioned hemisphere. Occasional cells were also detected in the cortex. In addition, reverse transcription-PCR revealed that no change in CD133 mRNA expression in injured brain tissue. These results suggested that fluid percussion injury induced CD133 antigen expression in the brain tissues as a result of conformational epitope changes, but not transcriptional expression.

Extracellular glycerol in patients with severe traumatic brain injury.

OBJECTIVE: To study the factors affecting extracellular glycerol (Gly) in patients with severe traumatic brain injury (STBI). METHODS: Perilesional extracellular Gly and cerebral blood flow (CBF) in 53 patients with STBI were consecutively monitored. Simultaneously, the intracranial pressure (ICP) and cerebral perfusion pressure (CCP) were monitored. The hourly minimum of CCP and CBF and the hourly maximum of ICP levels were matched with the hourly Gly. Gly values were divided into several groups according to regional ICP (less than 15 mm Hg or larger than 15 mm Hg), CCP (less than 70 mm Hg or larger than 70 mm Hg), CBF (less than 50 AU or 50-150 AU) and the outcomes (death or persistent vegetative state group, severe or moderate disability group, and good recovery group). RESULTS: In comparison with the severe or moderate disability group, the Gly concentration of the death or persistent vegetative state group increased significantly, but CBF and CCP decreased significantly. In comparison with the good recovery group, the Gly concentration of the severe or moderate disability group increased significantly, but CBF and CCP decreased significantly. The Gly concentrations in patients with ICP larger than 15 mm Hg, CCP less than 70 mm Hg and CBF less than 50 AU were respectively higher than those of patients with ICP less than 15 mm Hg, CCP larger than 70 mm Hg and 50 AU less than CBF less than 150 AU. In patients with diffuse axial injury, the mean Gly concentration was (201.17+/-55.00) micromol/L, which was significantly higher than that of the patients with epidural hematoma (n equal to 7, 73.26+/-8.37, P less than 0.05) or subdural hematoma (n equal to 9, 114.67+/-62.88, P less than 0.05), but it did not increase significantly when compared with those in patients with contusion(n equal to 24, 167.48+/-52.63). CONCLUSION: Gly can be taken as a marker for degradation of membrane phospholipids and ischemia, which reflects the severity of primary or secondary insult.

Effect of mild hypothermia on glucose metabolism and glycerol of brain tissue in patients with severe traumatic brain injury.

OBJECTIVE: To study the effect of mild hypothermia on glucose metabolism and glycerol of brain tissue in patients with severe traumatic brain injury (STBI) using clinical microdialysis. METHODS: Thirty-one patients with STBI(GCS less than or equal to 8) were randomly divided into hypothermic group(Group A) and control group(Group B). Microdialysis catheters were inserted into the cerebral cortex of perilesional and normal brain tissue. All samples were analyzed using CMA microdialysis analyzer. RESULTS: In comparison with the control group, lactate/glucose ratio(L/G), lactate/pyruvate ratio(L/P) and glycerol(Gly) in perilensional tissue were significantly decreased; L/P in normal brain tissue was significantly decreased. In control group, L/G, L/P and Gly in perilensional tissue were higher than that in normal brain tissue. In the hypothermic group, L/P in perilensional tissue was higher than that in relative normal brain. CONCLUSIONS: Mild hypothermia protects brain tissues by decreasing L/G, L/P and Gly in perilensional tissue and L/P in "normal brain" tissues. The energy crisis and membrane phospholipid degradation in perilensional tissue are easier to happen after traumatic brain injury, and mild hypothermia protects brain better in perilensional tissue than in normal brain tissue.

[Influence of temperature on extracellular glucose and lactate after traumatic brain injury].

OBJECTIVE: To study the changes of extracellular glucose (Glu), lactate (Lac), and the ratio of lactate/pyruvate (L/P) in patients with traumatic brain injury under different body temperatures. METHODS: Catheters for microdialysis were punctured into the penumbra zone of injured brain tissue (INJ), relatively normal brain tissue (NOR), and abdominal subcutaneous tissue (ABD) respectively in 51 patients to collect the fluid. The perfusion rate was 0.3 microl/min and one tube of fluid was collected for each hour. The average collection time was (67.10 +/- 18.27) hours. Concentrations of Glu, Lac, and pyruvate (Pyru) in the fluid were analyzed using CMA microdialysis analyzer. Patients were divided into 7 groups according to their rectal temperature (RT) values, which were RT < 33.0 degrees C, 33.0-33.9 degrees C, 34.0-34.9 degrees C, 35.0-35.9 degrees C, 36.0-36.9 degrees C, 37.0-37.9 degrees C, and > or = 38.0 degrees C. RESULTS: The concentration of Glu in ABD was significantly higher than that in the brain tissue (P < 0.05). The Glu in NOR were significantly higher and the highest in 33.0 degrees C compared with that in the INJ when RT < 36.0 degrees C (P < 0.05). The concentration of Lac in ABD was significantly lower than that in brain (P < 0.05). The Lac in NOR were much higher than that in INJ when RT < 35.0 degrees C or > or = 37.0 degrees C (P < 0.05). The ratio of L/P decreased along with the increase of body temperature (P < 0.001). The ratio of L/P significantly decreased in an order of INJ > ABD > NOR when RT was lower than 33.0 degrees C, which was changed to the order of NOR > INJ > ABD when RT was higher than 34.0 degrees C. CONCLUSION: Treatment of hypothermia may play more protective role when RT were between 33-34 degrees C or 36-37 degrees C.

Study on therapeutic mechanism and clinical effect of mild hypothermia in patients with severe head injury.

BACKGROUND: The therapeutic mechanism and clinical effect of mild hypothermia in patients with severe head injury were studied. METHODS: All 396 patients with severe head injury [Glasgow Coma Scale score (GCS) equal to or less than 8 on admission] were randomly divided into the hypothermic group (198 cases) and the control group (198 cases). Hypothermia was induced within 24 hours of injury. Rewarming began 1 to 7 days (average 62.4 +/- 27.6 h) after the rectal temperature (RT) reached 32.0 to 35.0 degrees C. Meanwhile, the vital signs, intracranial pressure (ICP), blood gas values, blood electrolytes, brain tissue oxygen pressure (P(bt)O2), brain tissue temperature (BT), cerebral blood flow (CBF), and jugular venous oxygen saturation (S(jv)O2) were measured. The rectal temperature of control patients was induced to 36.5 to 37.0 degrees C. According to GOS, the prognosis of the patients was evaluated. RESULTS: In comparison with control group, during mild hypothermia the high level of ICP, hyperglycemia and blood lactic acid significantly decreased (p < 0.05) and cerebral flow improved dominantly. The vital signs, blood gas values, and blood electrolytes did not change significantly. Decreased mortality and good recovery were also found in hypothermia group. CONCLUSIONS: Mild hypothermia is safe and effective for preventing brain damage on patients with severe head injury, as well as reducing mortality and improving the prognosis. It is important to monitor P(bt)O2, BT, CBF, and S(jv)O2 in hypothermic therapy.

Effect of mild hypothermia on partial pressure of oxygen in brain tissue and brain temperature in patients with severe head injury.

OBJECTIVE: To study the changes of partial pressure of oxygen in brain tissue (P(bt)O(2)) and brain temperature (BT) in patient s in acute phase of severe head injury, and to study the effect of mild hypothermia on P(bt)O(2) and BT. METHODS: The P(bt)O(2) and the BT of 18 patients with severe head injury were monitored, and the patients were treated with mild hypothermia within 20 hours after injury. The rectal temperature (RT) of the patients was kept on 31.5-34.9 degrees C for 1-7 days (57.7 hours+/-28.4 hours averagely), simultaneously, the indexes of P(bt)O(2) and BT were monitored for 1-5 days (with an average of 54.8 hours+/-27.0 hours). According to Glasgow Outcome Scale (GOS), the prognosis of the patients was evaluated at 6 months after injury. RESULTS: Within 24 hours after severe head injury, the P(bt)O(2) was significantly lower (9.6 mm Hg+/-6.8 mm Hg, 1 mm Hg=0.133 kPa) than the normal value (16-40 mm Hg). After treatment of mild hypothermia, the mean P(bt)O(2) increased to 28.7 mm Hg+/-8.8 mm Hg during the first 24 hours, and the P(bt)O(2) was still maintained within the range of normal value at 3 days after injury. The BT was higher than the RT in the patients in acute phase of severe head injury, and the difference between the BT and the RT significantly increased after treatment of mild hypothermia. Hyperventilation (the partial pressure of carbon dioxide in artery (P(a)CO(2)) approximately 25 mm Hg) decreased the high intracranial pressure (ICP) and significantly decreased the P(bt)O(2). CONCLUSIONS: This study demonstrates that P(pt)O(2) and BT monitoring is a safe, reliable and sensitive diagnostic method to follow cerebral oxygenation. It might become an important tool in our treatment regime for patients in the acute phase of severe head injury requiring hypothermia and hyperventilation.