TFP5 peptide, derived from CDK5-activating cofactor p35, provides neuroprotection in early-stage of adult ischemic stroke.

Cyclin-dependent kinase 5 (CDK5) is a multifaceted protein shown to play important roles in the central nervous system. Abundant evidence indicates that CDK5 hyperactivities associated with neuronal apoptosis and death following ischemic stroke. CDK5 activity increases when its cofactor p35 cleaves into p25 during ischemia. Theoretically, inhibition of CDK5/p25 activity or reduction of p25 would be neuroprotective. TFP5, a modified 24-aa peptide (Lys254-Ala277) derived from p35, was found to effectively inhibit CDK5 hyperactivity and improve the outcomes of Alzheimer's disease and Parkinson's disease in vivo. Here, we showed that intraperitoneal injection of TFP5 significantly decreased the size of ischemia in early-stage of adult ischemic stroke rats. Relative to controls, rats treated with TFP5 displayed reduced excitotoxicity, neuroinflammation, apoptosis, astrocytes damage, and blood-brain barrier disruption. Our findings suggested that TFP5 might serve as a potential therapeutic candidate for acute adult ischemic stroke.

TFP5 is comparable to mild hypothermia in improving neurological outcomes in early-stage ischemic stroke of adult rats.

AIM: We compared the efficacy of a modified truncated 24-aa peptide (TFP5), derived from the cyclin-dependent kinase 5 (CDK5)-activating cofactor p35, with mild hypothermia (MH), and determined whether the efficacy of TFP5 is affected by MH. METHODS: Ischemic stroke was induced in adult male Sprague-Dawley rats for 2h. Immediately after initiating reperfusion, TFP5, MH, or the combination of the two were administrated. 48h after reperfusion, neurological outcomes were evaluated. RESULTS: Rats that received either MH, TFP5, or the combined treatment showed smaller brain infarct size than normothermia control (NT), and there was no apparent difference among these three treatment groups. The neurological deficit was significantly improved only by the combined treatment. MH or TFP5 ameliorated the blood-brain barrier (BBB) disruption in ischemic regions with similar efficacy, whereas the combination of them had a trend toward better effect. Besides, the cleavage of p35 into p25 and apoptosis in ischemic regions was inhibited by TFP5 or the combination, but not by MH alone. CONCLUSIONS: TFP5 is comparable to MH in improving neurological outcomes in early-stage adult ischemic stroke. When TFP5 is given along with MH, less neurological deficit tends to be achieved.

Glibenclamide enhances the effects of delayed hypothermia after experimental stroke in rats.

In order to evaluate whether glibenclamide can extend the therapeutic window during which induced hypothermia can protect against stroke, we subjected adult male Sprague-Dawley rats to middle cerebral artery occlusion (MCAO). We first verified the protective effects of hypothermia induced at 0, 2, 4 or 6h after MCAO onset, and then we assessed the effects of the combination of glibenclamide and hypothermia at 6, 8 or 10h after MCAO onset. At 24h after MCAO, we assessed brain edema, infarct volume, modified neurological severity score, Evans Blue leakage and expression of Sulfonylurea receptor 1 (SUR1) protein and pro-inflammatory factors. No protective effects were observed when hypothermia was induced too long after MCAO. At 6h after MCAO onset, hypothermia alone failed to decrease cerebral edema and infarct volume, but the combination of glibenclamide and hypothermia decreased both. The combination also improved neurological outcome, ameliorated blood-brain barrier damage and decreased levels of COX-2, TNF-α and IL-1ß. These results suggest that glibenclamide enhances and extends the therapeutic effects of delayed hypothermia against ischemia stroke, potentially by ameliorating blood-brain barrier damage and declining levels of pro-inflammatory factors.

Hypothermia followed by rapid rewarming exacerbates ischemia-induced brain injury and augments inflammatory response in rats.

Hypothermia followed by slow rewarming is neuroprotective for ischemic stroke. However, slow rewarming causes patients' longer stay in intensive care unit and increases the risk of hypothermic complications. Hypothermia followed by rapid rewarming (HTRR) is more convenient; but it exacerbates intracranial hypertension for patients with massive hemispheric infarcts. The present study aims to investigate in detail how HTRR exacerbates ischemic brain injury and what are underlying mechanisms. Rats subjected to transient focal ischemia by middle cerebral artery occlusion were treated with normothermia or hypothermia followed by rapid rewarming. Neurological outcome, neuronal injury, blood-brain barrier integrity and expressions of inflammatory cytokines were observed. Results showed that HTRR at a rate of 3 °C/20 min increased both neurological deficit score and Longa score, enhanced the loss of neurons and the plasma level of neuron-specific enolase. Rapid rewarmed rats also displayed increased Evans blue dye extravasation, matrix metalloproteinase 9 level and tight junction impairment. Meanwhile, interleukin-1ß, -6, tumor necrosis factor α and cyclooxygenase-2 were markedly elevated in rapid rewarmed rats. Anti-inflammatory agent minocycline suppressed HTRR-induced elevation of inflammatory cytokines and improved neurological outcome. These results indicated that HTRR significantly impaired neurovascular unit and augmented proinflammatory response in stroke.

Effect of HDAC-6 on PD cell induced by lactacystin.

OBJECTIVE: To explore the effects of histone deacetylase 6(HDAC-6) on the PD cell model induced by proteasome inhibitor lactacystin. METHODS: Human neuroblastoma SK-N-SH cells were cultured. The wild type pcDNA3.1-alpha-synuclein eukaryotic expression plasmid was transferred into the cells which then were divided into control group, group L, group T and group T+L. The cells of group L were added with 5 µmol/L lactacystin dissolved indimethylsulfoxide (DMSO) to induce PD cell model with abnormal protein aggregation, the cells of control group were treated with 5 µmol/L DMSO, the cells of group T were treated with 5 µmol/L selective HDAC-6 inhibitor tubacin dissolved in DMSO, and the cells of group T+L were treated with 5 µmol/L lactacystin and 10 µmol/L tubacin dissolved in DMSO. The expression levels of alpha-synuclein oligomers, HSP-27 and HSP-70 were detected by Western blot and the cell survival rate of all the groups was detected by MTT colorimetric assay, and compared 24 h after the cells were treated. RESULTS: The expression levels of alpha-synuclein oligomers, HSP-27 and HSP-70 of the cells of group L were significantly higher than the control group, and the cell survival rate was significantly lower (P < 0.05); the expression level of alpha-synuclein oligomers of the cells of group T+L was significantly higher than group L, but the expression level of HSP-27 and HSP-70 were significantly lower, and so as the cell survival rate (P < 0.05); the differences of the expression level of alpha-synuclein oligomers, HSP-27 and HSP-70 and the cell survival rate of the cells of group T and the control group were not statistically significant (P > 0.05). CONCLUSIONS: The expression level of alpha-synuclein oligomers can be improved and the cell survival rate can be reduced by the PD cell model induced by lactacystin and treated with selective HDAC-6 inhibitor tubacin, which means that alpha-synuclein oligomers of the PD cell model induced by lactacystin can be inhibited and the cell survival rate can be improved by HDAC-6, and the mechanism may be related to the increased of HSP-27 and HSP-70.

Guillain-Barré syndrome following sepsis after stereotactic aspiration for spontaneous pontine hemorrhage.

A 52-year-old female was treated with CT-guided stereotactic aspiration for acute spontaneous pontine hemorrhage. On postoperative day 7, the patient was complicated by Acinetobacter baumannii sepsis. As sepsis was stabilized, she developed flaccid weakness and autonomic dysfunction on postoperative day 21. Investigations including neurophysiological studies and cerebral spinal fluid analysis prompted the diagnosis of acute motor axonal neuropathy, a variant of Guillain-Barré syndrome. Intravenous administration of immunoglobulin resolved her potentially life-threatening autonomic instability. At 1-year follow-up, she was able to stand with significant assistance. Although Guillain-Barré syndrome rarely occurs, clinicians should be alert to the possibility of this potentially life-threatening consequence after cranial surgery with severe respiratory infection.

The measurement of vesical detrusor electromyographic activity during nerve-sparing radical hysterectomy.

OBJECTIVE: To evaluate the feasibility for confirming the preservation of the parasymphathetic nerve pathway innervating the bladder during nerve-sparing radical hysterectomy (RH). METHODS: A total of 20 patients underwent nerve-sparing RH. Intraoperative electrical stimulation (IES) were performed on the root of pelvic splanchnic nerve (PSN) trunk while recording the electromyographic (EMG) activity of the vesical detrusor. The average duration achieving residual urine ≤50 mL and urodynamic study (UDS) was observed. RESULTS: Evoked potentials were recorded when stimulating, in 18 patients who were referred IES-positive. Its duration was 9.89 days. The UDS results indicated that all voided normally. The remaining 2 IES-negative cases with no evoked potentials had longer duration and the micturitions were performed using abdominal pressure. CONCLUSION: During nerve-sparing RH, IES based on the measurement of EMG activity is a useful tool for confirmation of the preservation of parasymphathetic nerve pathway innervating the bladder and prediction of the postoperative bladder function.

[Relationship between cystatin C and cerebral infarction].

OBJECTIVE: To study the relationship between cystatin C and cerebral infarction and explore the role of cystatin C in the protection against cerebral infarction. METHOD: Eighty-three patients with cerebral infarction and 71 randomly selected age- and gender-matched patients in the Department of Neurology (control group) were enrolled in this study. Fasting whole blood (3 ml) was obtained from the patients in both groups and the sera were separated to determine the levels of cystatin C using particle reinforced immunoturbidimetric assay. RESULTS: The serum cystatin C level was significantly lower in the cerebral infarction group than in the control group (1.62-/+0.31 vs 2.23-/+0.22 mg/L, P<0.01). CONCLUSIONS: Cystatin C is closely related to cerebral infarction probably as a protective factor against cerebral infarction.

[Value of lower-limb short latency somatosensory evoked potentials in predicting early death in patients with massive cerebral infarction].

OBJECTIVE: To explore the value of lower-limb short latency somatosensory evoked potentials (SLSEP) in predicting early death in patients with massive cerebral infarction. METHODS: Forty-eight patients of massive cerebral infarction were admitted in the Neurological Intensive Care Unit (NICU) between March 2008 and March 2009, and Glasgow-Pittsburgh coma scale (GPCS) and SLSEP were recorded and graded within 24 h after admission. The patients were divided into survival and death groups (including brain death) according to their short-term prognosis. The correlations of SLSEP and GPCS to the mortality were assessed. RESULTS: A significant correlation was found between SLSEP and the mortality in patients with massive cerebral infarction (r=0.484, P<0.001). The positive predictive value of the SLSEP grade 3 to death was 100%, and the patients with malignant middle cerebral artery infarction (mMCAI) appeared to have a 100% mortality. CONCLUSION: SLSEP grade 3 can be a highly specificity in predicting early death in patients with massive cerebral infarction, and it is also of value in determining the timing of surgical intervention of mMCAI.

[Relationship of interleukin-1beta, tumor necrosis factors-beta and interleukin-10 gene polymorphisms with serum lipoprotein level in Chinese Han population in Guangdong Province].

OBJECTIVE: To investigate the association of IL-1beta+3953, TNFbeta+252 and IL-10-592 polymorphisms with serum lipoprotein levels in Chinese Han population in Guangdong Province. METHODS: A total of 428 individuals of Han nationality from Guangdong Province were enrolled in this study. The genotypes of IL-1beta+3953, TNFbeta+252 and IL-10-592 sites were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The serum concentrations of total cholesterol (TC), TG, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and very low density lipoprotein (VLDL) were determined using an automatic biochemistry analyzer. RESULTS: The concentrations of TC and LDL in individuals of TNFbeta+252GA genotype was significantly higher than that in TNFbeta+252AA genotype (t=-2.406, P=0.017; t=-2.516, P=0.012). The concentration of LDL in IL-10+3953CT genotype was significantly higher than that in IL-10+3953CC genotype (2.743-/+0.723 vs 2.502-/+0.699 mmol/L, t=-2.639, P=0.009). No significant differences were found in TG, TC, HDL, LDL and VLDL between the 3 genotypes (P>0.05). CONCLUSION: The polymorphisms of proinflammatory cytokines are related to the serum lipoprotein level in these subjects. The T allele in IL-1beta+3953 and the G allele in TNFbeta+252 are positively correlated to dyslipidemia.

[Pathological analysis of heroin spongiform leukoencephalopathy].

OBJECTIVE: To investigate the pathological characteristics of heroin spongiform leukoencephalopathy (HSLE). METHODS: Cerebral tissue specimens were obtained from 15 patients with HSLE and the histological observations under optical and electron microscopes were carried out by HE, Bielschowsky's, and chromotrope 2R-brilliant green staining. RESULTS: HSLE was characterized primarily by spongiform vacuolar degeneration of the cerebral white matter. Neurons in the gray matter, Purkinje and granular cells in the cerebella remain intact in all the cases. Numerous vacuoles, which merged to form larger cavities, appeared in the damaged white matter, and the axons survived in the deep white matter. The myelin sheath in the cerebellar white matter sustained more severe damages than those in the cerebral white matter. No vacuoles or lymphocyte infiltration occurred in the small peripheral vessels. CONCLUSION: HSLE is pathologically characterized by vacuolar degeneration due to primary damage of the myelin, and the spongiform vacuolar degeneration is closely associated with the severity of demyelination in the white matter.

C242T p22phox gene polymorphism in the population of Han nationality in Guangdong province.

This study aimed to investigate the gene polymorphism of the C242T p22phox in the population of Han nationality in Guangdong Province by randomly selecting 122 unrelated healthy candidates examined by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). It was found that the C and T allele frequencies were 0.934 and 0.066, and CC and CT+TT genotype frequencies were 0.877 and 0.123, respectively, in the population of Han nationality in Guangdong Province, suggesting the presence of C242T p22phox gene polymorphism with significant racial differences.