Lower Glial Fibrillary Acidic Protein Research Articles

Association of Biomarkers of Neuronal Injury and Inflammation With Insomnia Trajectories After Traumatic Brain Injury: A TRACK-TBI Study.

Insomnia affects about one-third of patients with traumatic brain injury and is associated with worsened outcomes after injury. We hypothesized that higher levels of plasma neuroinflammation biomarkers at the time of TBI would be associated with worse 12-month insomnia trajectories. Participants were prospectively enrolled from 18 level-1 trauma centers participating in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study from February 26, 2014, to August 8, 2018. Plasma glial fibrillary acidic protein (GFAP), high-sensitivity C-reactive protein (hsCRP), S100b, neuron-specific enolase (NSE), and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) were collected on days 1 (D1) and 14 (D14) after TBI. The insomnia severity index was collected at 2 weeks, 3, 6, and 12 months postinjury. Participants were classified into insomnia trajectory classes based on a latent class model. We assessed the association of biomarkers with insomnia trajectories, controlling for medical and psychological comorbidities and demographics. Two thousand twenty-two individuals with TBI were studied. Elevations in D1 hsCRP were associated with persistent insomnia (severe, odds ratio [OR] = 1.33 [1.11, 1.59], p = 0.002; mild, OR = 1.10 [1.02, 1.19], p = 0.011). Similarly, D14 hsCRP elevations were associated with persistent insomnia (severe, OR = 1.27 [1.02, 1.59], p = 0.03). Of interest, D1 GFAP was lower in persistent severe insomnia (median [Q1, Q3]: 154 [19, 445] pg/mL) compared with resolving mild (491 [154, 1,423], p < 0.001) and persistent mild (344 [79, 1,287], p < 0.001). D14 GFAP was similarly lower in persistent (11.8 [6.4, 19.4], p = 0.001) and resolving (13.9 [10.3, 20.7], p = 0.011) severe insomnia compared with resolving mild (20.6 [12.4, 39.6]. Accordingly, increases in D1 GFAP were associated with reduced likelihood of having persistent severe (OR = 0.76 [95% CI 0.63-0.92], p = 0.004) and persistent mild (OR = 0.88 [0.81, 0.96], p = 0.003) compared with mild resolving insomnia. No differences were found with other biomarkers. Elevated plasma hsCRP and, surprisingly, lower GFAP were associated with adverse insomnia trajectories after TBI. Results support future prospective studies to examine their utility in guiding insomnia care after TBI. Further work is needed to explore potential mechanistic connections between GFAP levels and the adverse insomnia trajectories.

Comprehensive analysis of brain injury parameters in a preclinical porcine model of acute liver failure.

Acute liver failure (ALF) is defined as acute loss of liver function leading to hepatic encephalopathy associated with a high risk of patient death. Brain injury markers in serum and tissue can help detect and monitor ALF-associated brain injury. This study compares different brain injury parameters in plasma and tissue along with the progression of ALF. ALF was induced by performing an 85% liver resection. Following the resection, animals were recovered and monitored for up to 48 h or until reaching the predefined endpoint of receiving standard medical therapy (SMT). Blood and serum samples were taken at Tbaseline, T24, and upon reaching the endpoint (Tend). Control animals were euthanized by exsanguination following plasma sampling. Postmortem brain tissue samples were collected from the frontal cortex (FCTx) and cerebellum (Cb) of all animals. Glial fibrillary acidic protein (GFAP) and tau protein and mRNA levels were quantified using ELISA and qRT-PCR in all plasma and brain samples. Plasma neurofilament light (NFL) was also measured using ELISA. All ALF animals (n = 4) were euthanized upon showing signs of brain herniation. Evaluation of brain injury biomarkers revealed that GFAP was elevated in ALF animals at T24h and Tend, while Tau and NFL concentrations were unchanged. Moreover, plasma glial fibrillary acidic protein (GFAP) levels were negatively correlated with total protein and positively correlated with both aspartate transaminase (AST) and alkaline phosphatase (AP). Additionally, lower GFAP and tau RNA expressions were observed in the FCTx of the ALF group but not in the CB tissue. The current large animal study has identified a strong correlation between GFAP concentration in the blood and markers of ALF. Additionally, the protein and gene expression analyses in the FCTx revealed that this area appears to be susceptible, while the CB is protected from the detrimental impacts of ALF-associated brain swelling. These results warrant further studies to investigate the mechanisms behind this process.

Abstract 151: GFAP Measurements for Rapid Prehospital Identification of Intracranial Hemorrhage in Patients With Acute Coma

Background: Prehospital triage and treatment of patients with acute coma is challenging for rescue services, as the underlying pathogenetic conditions are highly heterogenous and difficult to assess. Glial fibrillary acidic protein (GFAP) has been recently identified as a biomarker of intracerebral hemorrhage. The aim of this study was to test the diagnostic value of a GFAP point-of-care(poc) device to rapidly differentiate intracranial hemorrhage from other causes of acute coma (including seizures, metabolic disorders, cardiovascular disorders, and intoxication) in the prehospital phase. Methods: Patients who were admitted to the emergency department due to acute coma (Glasgow Coma Scale scores between 3-8) were enrolled prospectively. Blood samples were collected already in the prehospital phase. Plasma GFAP measurements were performed on the i-STAT Alinity® (Abbott) device (duration of analysis 15 min). The primary endpoint was the final diagnosis at hospital discharge. Results: 95 patients were enrolled (mean age 64±20 years, 43% female). GFAP concentrations were strongly elevated in patients with a primary cerebral cause of coma compared to primary non-cerebral causes (p&lt;0.001). The GFAP concentrations (mean±SD in pg/mL) according to final diagnosis were as follows: intracerebral hemorrhage 4840±4500 (n=15), subarachnoid hemorrhage 4858±4662 (n=11), subdural or epidural hematoma 3462±4005 (n=4), ischemic stroke 992±2857 (n=12), seizure 45±21 (n=11), cardiovascular or metabolic disorder 258±888 (n=29), intoxication 30±2 (n=6), psychogenic stupor 29±0 (n=2); n=5 patients had missing diagnoses. GFAP values over 1000 pg/ml indicated a primary cerebral cause of coma with 100% certainty (hereof, 86% had intracranial hemorrhage). Conclusion: Increased GFAP plasma values in patients with acute coma identify a primary cerebral cause of coma (mostly intracranial hemorrhage) with very high diagnostic accuracy. Patients with primary non-cerebral causes of coma showed overall low GFAP concentrations. Prehospital GFAP measurements on a poc platform may allow rapid stratification according to the underlying cause of coma by rescue services. This could have major impact on triage and management of these critically ill patients.

Neurofilament light chain on intensive care admission is an independent predictor of mortality in COVID-19: a prospective multicenter study

BackgroundNeurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and total-tau protein (tau) are novel blood biomarkers of neurological injury, and may be used to predict outcomes in critical COVID-19.MethodsA prospective multicentre cohort study of 117 consecutive and critically ill COVID-19 patients in six intensive care units (ICUs) in southern Sweden between May and November 2020. Serial NfL, GFAP and tau were analysed in relation to mortality, the Glasgow Outcome Scale Extended (GOSE) and the physical (PCS) and mental (MCS) components of health-related quality of life at one year.ResultsNfL, GFAP and tau on ICU admission predicted one-year mortality with an area under the curve (AUC) of 0.82 (95% confidence interval [CI] 0.74-0.90), 0.72 (95% CI 0.62-0.82) and 0.66 (95% CI 0.54-0.77). NfL on admission was an independent predictor of one-year mortality (p = 0.039). Low NfL and GFAP values were associated with good PCS (ge45) at one year but not with good MCS (ge45) or GOSE (ge5).ConclusionsNfL on ICU admission was an independent predictor of mortality. High levels of NfL, GFAP and tau were associated with mortality but not with poor GOSE in survivors at one year. Low levels of NfL and GFAP were associated with improved physical health-related quality of life.Graphical

Glial suppression and post-traumatic stress disorder: A cross-sectional study of 1,520 world trade center responders

BackgroundChronically re-experiencing the memory of a traumatic event might cause a glial response. This study examined whether glial activation would be associated with PTSD in a study of responders present after the 9/11 World Trade Center attacks without comorbid cerebrovascular disease. MethodsPlasma was retrieved from 1,520 WTC responders and stored for a cross-sectional sample of responders of varying levels of exposure and PTSD. Plasma levels (pg/ml) of glial fibrillary acidic protein (GFAP) were assayed. Because stroke and other cerebrovascular diseases cause distributional shifts in GFAP levels, multivariable-adjusted finite mixture models analyzed GFAP distributions in responders with and without possible cerebrovascular disease. ResultsResponders were aged 56.3 years and primarily male; 11.07% (n = 154) had chronic PTSD. Older age was associated with increased GFAP, whereas higher body mass was associated with decreased GFAP. Multivariable-adjusted finite mixture models revealed that severe re-experiencing trauma from 9/11 was associated with lower GFAP (B = −0.558, p = 0.003). ConclusionThis study presents evidence of reduced plasma GFAP levels among WTC responders with PTSD. Results suggest re-experiencing traumatic events might cause glial suppression.

Characterizing Factors Influencing Baseline Plasma Biomarkers for Sport-Related Concussion in Adolescents.

Abstract Developing objective measures to diagnose sport-related concussion (SRC) is a top priority, particularly in the pediatric context, given the vulnerability of the developing brain. While advances in SRC blood biomarkers are being made in adult populations, less data are available for adolescents. Clinical validation of blood biomarkers post-SRC will first require investigation in a healthy uninjured state. Further, rapid pubertal changes during adolescence may implicate possible interactions with circulating sex hormones and the menstrual cycle for females. This cross-sectional study aimed to characterize pre-injury plasma levels of glial fibrillary acidic protein (GFAP), neurofilament light (NF-L), ubiquitin C-terminal hydrolase-L1 (UCH-L1), total tau (T-tau), and phosphorylated tau-181 (P-tau-181), considering previous concussion, age, and sex in healthy adolescent sport participants. Possible associations with menstrual cycle phase and circulating sex hormone levels (i.e., progesterone, estradiol, testosterone) were also explored. Pre-injury blood samples were obtained from 149 healthy adolescents (48% female, ages 11-18) participating in a larger Surveillance in High Schools and Community Sports to Reduce Concussions and their Consequences (SHRed Concussions) multi-site longitudinal cohort study. Main outcomes were natural log (ln) transformed plasma GFAP, NF-L, UCH-L1, T-tau, and P-tau-181 concentrations, quantified on the Quanterix Simoa HD-X platform. Mixed-effects multi-variable linear regression was used to assess associations between biomarkers and self-reported previous concussion (yes/no), age (years), sex (male/female), objectively determined menstrual cycle phase (follicular/luteal), plasma progesterone, estradiol, and testosterone. Males had 19.8% lower UCH-L1 (β = -0.221, 95% confidence interval [CI; -0.396, -0.046]), 18.9% lower GFAP (β = -0.210, 95% CI [-0.352, -0.068]), and 21.8% higher P-tau-181 (β = 0.197, 95% CI [0.048, 0.346]) compared with females, adjusting for age and previous concussion. GFAP decreased 9.5% with each 1-year increase in age, adjusting for previous concussion and sex (β = -0.100, 95% CI [-0.152, -0.049]). No biomarkers were associated with a history of previous concussion. Exploratory investigations found no associations between biomarkers and menstrual cycle phase. Females displayed an age-adjusted negative association between T-tau and progesterone (β = -0.010, 95% CI [-0.018, -0.002]), whereas males had a negative age-adjusted association between UCH-L1 and testosterone (β = -0.020, 95% CI [-0.037, -0.002]). As such, age- and sex-specific reference intervals may be warranted for pediatric athlete populations prior to clinical validation of blood biomarkers for SRC. Additionally, hormonal associations highlight the need to consider puberty and development in adolescent studies. Overall, findings suggest these biomarkers are resilient to a history of previous concussion and menstrual cycle phase, supporting continued investigation in adolescent SRC.

Plasma glial fibrillary acidic protein as a moderator along the Alzheimer’s disease biomarker cascade

AbstractBackgroundAstrocyte reactivity may contribute to pathogenic relationships between β‐amyloid (A), phosphorylated tau (T), neurodegeneration (N), and cognition (memory). We examined whether severity of astrocyte reactivity, characterized by plasma glial fibrillary acidic protein (GFAP), moderates relationships along the A/T/N and memory cascade in non‐demented adults.MethodPlasma phosphorylated tau181 (P‐tau181) and GFAP concentrations (Quanterix Simoa) were measured in cognitively unimpaired (CU) individuals and patients with mild cognitive impairment (MCI). Analyses were conducted on overlapping sample subsets (aged 52‐92) with florbetapir Aβ‐PET (112 CU [80 Aβ‐, 32 Aβ+; SUVR&gt;1.11], 29 MCI [all Aβ+]), structural MRI (139 CU, 39 MCI), and memory testing (168 CU, 45 MCI). Linear regression tested statistical moderation of plasma GFAP on the association of Aβ‐PET (A) with plasma P‐tau181 (T), and on associations of plasma P‐tau181 with hippocampal volume (N) and composite memory z‐scores (cognition). To probe moderation effects, region of significance analyses identified percentile thresholds along the plasma GFAP distribution at which statistically significant A/T/N and cognition associations emerged. Covariates included age, sex, APOE genotype, education (cognitive analysis), and intracranial volume (MRI analysis).ResultPlasma GFAP significantly moderated the relationship between Aβ‐PET and plasma P‐tau181 (β=0.23, p=.003) and the relationship between plasma P‐tau181 and memory (β=‐0.18, p=.027). Region of significance analyses detected significantly higher plasma P‐tau181 concentrations in Aβ+ (vs. Aβ‐) only above the 17th percentile of plasma GFAP, whereas the significant relationship between higher plasma P‐tau181 and worse memory was only detected above the 73rd percentile of plasma GFAP. Plasma GFAP did not moderate the relationship between plasma P‐tau181 and hippocampal volume (p=.648); however, both plasma P‐tau181 (β=‐0.20, p=.004) and GFAP (β=‐0.16, p=.035) independently related to smaller hippocampal volume.ConclusionAdverse associations along the A/T/N and memory cascade only emerged with increasing plasma GFAP concentrations, with a higher GFAP threshold needed to detect plasma P‐tau181‐related memory associations than Aβ‐related elevations in plasma P‐tau181. These adverse associations were absent at low GFAP levels, suggesting less severe astrocyte reactivity may buffer against AD pathological changes. As a non‐invasive marker of astrocyte reactivity, incorporating plasma GFAP into AD biomarker models may enhance characterization of AD risk and resilience.

Plasma biomarkers associated with deployment trauma and its consequences in post-9/11 era veterans: initial findings from the TRACTS longitudinal cohort

Mild traumatic brain injury (mTBI) is among the most common injuries sustained by post-9/11 veterans; however, these injuries often occur within the context of psychological trauma. Blast exposure, even in the absence of a diagnosable TBI, leads to changes in neural connectivity and congitive functioning. Therefore, considering clinical comorbidities and injury characteristics is critical to understanding the long-term effects of mTBI. Research is moving towards identifying diagnostic and prognostic blood-based biomarkers for TBI; however, few studies include other prevalent clinical and medical comorbidities related to deployment. Here, we present the initial cross-sectional relationships between plasma biomarkers, clinical, and medical comorbidities in a well-characterized longitudinal sample of 550 post-9/11 veteran men and women. We examined biomarkers associated with inflammation (interleukin 6 and 10, tumor necrosis factor α, and eotaxin) and neurodegeneration (neurofilament light, glial fibrillary acidic protein (GFAP), tau, brain derived neurotrophic factor, amyloid ß 40 and 42, phosphorylated neurofilament heavy chain, and neuron specific enolase). Univariate analyses of covariance (ANCOVA) were conducted to determine mean level differences between close blast (blasts that occur within 0–10 meters) and mTBI groups. Our primary findings were twofold: (1) Inflammatory markers were consistently higher in participants exposed to close blasts and were strongly related to deployment-related psychopathology. (2) GFAP was consistently lower in participants exposed to blast and mTBI and lower GFAP was associated with more severe psychological symptoms. More research is clearly needed; however, our findings indicate that chronic increased inflammation and decreased GFAP may be related to close blast exposure.

The effects of early treadmill training combined with ultrashort wave irradiation on functional recovery from spinal cord injury

Objective To investigate the effect of early-stage training combined with the ultrashort wave therapy on the functional recovery of rats after a spinal cord injury, and to observe the expression of aquaporin protein-4 (AQP-4) and glial fibrillary acidic protein (GFAP). Methods Fifty female Sprague-Dawley rats had spinal cord injury (SCI) induced using the modified Allen′s method. After successful modeling, 40 were randomly divided into a sham operation group, a control group, an ultrashort wave group, a treadmill group and a combined group, each of 8. Motor function in their hind limbs was evaluated 4 weeks after the operation using BBB scoring. GFAP and AQP-4 immunohistochemical staining were used to determine the integral optical density (IOD) of the protein expression. Results The average BBB score of the sham operation group was 21, while the other four groups averages were all less than 1 on the 1st day after the operation. They gradually increased with time, and by 4 weeks the increases were significant. Compared with the control group at the same time point, the average BBB scores of the treadmill and the combined groups were significantly higher. Compared with the ultrashort wave group, the average BBB score of the treadmill group was higher after 4 weeks, and the combined group′s average was significantly higher at 2, 3 and 4 weeks after the operation. Four weeks after the SCI modeling, the average AQP-4 IOD and GFAP IOD levels of the ultrashort wave group, the treadmill group and the combined group were lower than that of the control group, while the average AQP-4 and GFAP IOD levels of the combined group were significantly lower than those of the ultrashort wave group. Compared with the treadmill group, the combined group had a significantly lower average GFAP level. Conclusions Both treadmill training and ultrashort wave treatment promote motor function recovery after a spinal cord injury. The mechanism may be related to downregulation of AQP-4 and GFAP expression at the injured site. Combining the two treatments gives better effects. Key words: Spinal cord injury; Treadmill training; Ultrashort wave irradiation; Auaporin protein-4; Glial fibrillary acidic protein

The combined effect of granulocyte-colony stimulating factor (G-CSF) treatment and exercise in rats with spinal cord injury

Objective: To identify that the combined G-CSF and treadmill exercise is more effective in functional recovery after spinal cord injury (SCI).Design: Rats were divided into 4 groups: a SCI group treated with G-CSF (G-CSF group, n = 6), a SCI group treated with treadmill exercise plus G-CSF (G-CSF/exercise group, n = 6), a SCI group with treadmill exercise (exercise group, n = 6), and a SCI group without treatments (control group, n = 6). We performed laminectomy at the T8–10 spinal levels with compression injury of the spinal cord in all rats. G-CSF (20 μg/ml) was administered intraperitoneally for 5 consecutive days after SCI in G-CSF and G-CSF/exercise groups. From one week after surgery, animals in G-CSF/exercise and exercise groups received 30 min of exercise 5 days per week for 4 weeks. Functional recoveries were assessed using the Basso, Beattie, and Bresnahan (BBB) scale and the inclined plane test. Five weeks after SCI, hematoxylin and eosin staining for cavity size and immunohistochemistry for glial scar formation and neuro-regeneration factor expression were conducted.Setting: Inha University School of medicine, Incheon, KoreaResults: Rats in G-CSF/exercise group showed the most effective functional recovery in the BBB scale and the inclined plane test, and spinal cord cavity size by injury were the smallest, and immunohistochemistry revealed expression of higher BDNF (brain-derived neurotrophic factor) and VEGF (vascular endothelial growth factor) and lower GFAP (glial fibrillary acidic protein) than others.Conclusion: Combined treatment provided more effective neuroplasty and functional recovery than individual treatments.

In vitro study of central nervous system foreign body response towards hydrogel particle modified planar substrate.

Central nervous system (CNS) neural device functionality hinges on effective communication with surrounding neurons. This depends on both the permissiveness of the device material to promote neuron integration and the ability of the device to avoid a chronic inflammatory response. Previously our lab developed a method using surface adsorbed hydrogel particles (HPs) to promote neuron integration onto typically non-neural-permissive substrates. However, little information is known regarding CNS inflammatory cell type responses towards the modified HP surface. In vitro adhesion, proliferation, and activation studies were implemented using NIH 3T3, RAW 264.7, and A172 cell lines to model fibroblast, macrophages and activated microglia, and astrocytes, respectively. For all cell types, the HP modified substrates elicited cell adhesion and sustained cell metabolic activity during a 3-day culture. RAW 264.7 cell activation was evaluated using a tumor necrosis factor-alpha (TNF-α) enzyme-linked immunosorbent assay and scanning electron microscope (SEM) imaging. Quantified TNF-α levels from the LbL/HP cells were greater than the control substrate, however, investigation with SEM suggested these cells' morphology was different from a typical activated state. A172 cell activation was evaluated by fluorescent staining of glial fibrillary acidic protein (GFAP) and SEM imaging, which revealed similarly low GFAP levels on both bare and HP modified substrates. A172 cell morphology showed mainly an undifferentiated and non-activated state. These results help lay the groundwork to design the HP system for future in vitro and in vivo investigations to ultimately realize stable long-term neural device communication. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3242-3250, 2017.

Glial fibrillary acidic protein is differentially expressed across cortical and subcortical regions in healthy brains and downregulated in the thalamus and caudate nucleus of depressed suicides.

There is mounting evidence to suggest aberrant astrocytic function in depression and suicide. Independent studies have reported astrocytic abnormalities in certain brain regions, but it remains unclear whether this is a brain-wide phenomenon. The present study examined this question by measuring glial fibrillary acidic protein (GFAP) expression in postmortem brain samples from suicide completers and matched non-psychiatric controls. Suicide completers were selected based on their recent characterization as low GFAP expressors in the prefrontal cortex, (Brodmann areas 8/9 and 10). Real-time PCR and immunoblotting were used to measure GFAP gene expression and protein levels in BA4 (primary motor cortex), BA17 (primary visual cortex), cerebellar cortex, mediodorsal thalamus and caudate nucleus. We found downregulation of GFAP mRNA and protein in the mediodorsal thalamus and caudate nucleus of depressed suicides compared with controls, whereas GFAP expression in other brain regions was similar between groups. Furthermore, a regional comparison including all samples revealed that GFAP expression in both subcortical regions was, on average, between 11- and 15-fold greater than in cerebellum and neocortex. Examining astrocyte morphology by immunohistochemistry showed that astrocytes in both thalamus and caudate displayed larger cell bodies and extended more ramified processes across larger domains than the previously described cortical astrocytes. This study reveals that astrocytic abnormalities are not brain wide and suggests that they are restricted to cortical and subcortical networks known to be affected in mood disorders. Additionally, our results show a greater diversity in human astrocytic phenotypes than previously thought.

Abstract 602: RAS-induced Hypertension Is Primarily Mediated By (Pro)renin Receptor Activation At The Paraventricular Nucleus Of The Hypothalamus.

Studies have shown that renin-angiotensin-system (RAS)-induced inflammation at the paraventricular nucleus of the hypothalamus (PVN) contributes to hypertension development by increasing sympathetic outflow and elevating blood pressure. Recent data suggest that PRR activation increases pro-inflammatory cytokine (PIC) production in an Ang II-independent manner helping sustain kidney inflammation, retinal disease and diabetic neuropathy. Astrocytes house all the components of the RAS and help regulate the immune response within the brain. However, the role of (pro)renin (PRO) receptor (PRR) activation at the PVN on blood pressure regulation and astrocyte activation has not been evaluated. We show that at the PVN, 12 weeks old spontaneously hypertensive rats (SHRs) have significantly (p &lt; 0.05) higher PRR mRNA levels than normotensive Wistar Kyoto (WKY) and Sprague Dawley (SD) rats (1.6 ± 0.3 vs. 0.96 ± 0.4 &amp; 1.0 ± 0.2, SHR, WKY and SD respectively). In situ-hybridization data using RNA Scope, confirmed these results as qualitative analysis from coronal sections containing the PVN from SD and WKY rats showed lower PRR signal when compared to those from SHRs. Our data shows that bilateral downregulation of the PRR, using a short-hairpin RNA (shRNA) vector construct, at the PVN of SHRs (n = 5) reduces blood pressure compared to control animals (n = 5) with PRR levels intact (146.1 ± 6.6 vs. 133.3 ± 9.0 mmHG; p &lt; 0.05). Similarly, PRR downregulation at the PVN can also reduce the pressor response triggered by sub-cutaneous Ang II infusion (200ng/kg/min) in SD rats (143 ± 13.2 vs. 114.8 ± 13.2 mmHG, p &lt; 0.05; control vs. shRNA animals, respectively). In both experimental designs, blood pressure decreases were not accompanied by changes in heart rate. Our results also show lower glial fibrillary acidic protein (GFAP) and interleukin (IL)-1β mRNA levels at the PVN in shRNA-injected animals and using the Image J tool we show a trend for astroglial area fraction in the PVN to decrease. These changes are in concert with our in vitro data which show that PRO increases PICs levels and astrogliosis in cultured astrocytes. Our findings show that at the PVN, PRR activation is key in RAS-induced hypertension and potential mechanisms may include astrocyte- and neuroimmune activation.

Microtransplantation of whole ganglionic eminence cells ameliorates motor deficit, enlarges the volume of grafts, and prolongs survival in a rat model of Huntington's disease

Studies have demonstrated that embryonic cell therapy is a potential approach for the treatment of Huntington's disease (HD). However, because of the limited resource of embryos, greater attention is needed in developing more efficient surgical techniques that not only enhance the therapy outcome but also avoid inefficient therapeutics of transplantation. In this study, we explored the curative effects of two different transplantation methods using a rat model of HD. Whole ganglionic eminence (WGE) cells or phosphate-buffered saline were transplanted into unilateral striatum of quinolinic acid (QA)-lesioned rats using microtransplantation instruments (with an outer diameter of 50 μm) or traditional transplantation instruments (with an outer diameter of 470 μm). Apomorphine-induced rotation test and adjusting step test were assessed after QA-induced lesion and 2, 4, 6, 8, 10, and 12 weeks after transplantation. The expression of neuronal nuclei (NeuN), dopamine, cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32), and glial fibrillary acidic protein (GFAP) was analyzed at 12 weeks after transplantation. We observed that microtransplanted rats performed better in the stepping test and had higher numbers of DARPP-32-positive cells compared with traditionally transplanted rats. Moreover, microtransplantation group showed lower GFAP expression surrounding the grafts in unilateral striatum and a higher survival rate posttransplantation compared with the traditional transplantation group. We conclude that microtransplantation is capable of enhancing therapeutic efficacy in the rat model of HD. This finding establishes the basis of an alternative transplantation strategy for treatment of HD.

SC1/Hevin and Reactive Gliosis After Transient Ischemic Stroke in Young and Aged Rats

SC1 is a member of the SPARC family of glycoproteins that regulate cell-matrix interactions in the developing brain. SC1 is expressed in astrocytes, but nothing is known about the expression in the aged or after stroke. We found that after focal striatal ischemic infarction in adult rats, SC1 increased in astrocytes surrounding the infarct and in the glial scar, but in aged rats, SC1 was lower at the lesion edge. Glial fibrillary acidic protein (GFAP) also increased, but it was less prominent in reactive astrocytes further from the lesion in the aged rats. On the basis of their differential expression of several molecules, 2 types of reactive astrocytes with differing spatiotemporal distributions were identified. On Days 3 and 7, SC1 was prevalent in cells expressing markers of classic reactive astrocytes (GFAP, vimentin, nestin, S100β), as well as apoliprotein E (ApoE), interleukin 1β, aggrecanase 1 (ADAMTS4), and heat shock protein 25 (Hsp25). Adjacent to the lesion on Days 1 and 3, astrocytes with low GFAP levels and a "starburst" SC1 pattern expressed S100β, ApoE, and Hsp32 but not vimentin, nestin, interleukin 1β, ADAMTS4, or Hsp25. Neither cell type was immunoreactive for NG2,CC-1, CD11b, or ionized calcium-binding adapter-1. Their differing expression of inflammation-related and putatively protective molecules suggests different roles for starburst and classic reactive astrocytes in the early glial responses to ischemia.

GC/MS detection of central nervous tissue as specified BSE risk material in meat products and meat and bone meals: thermal stability of markers in comparison with immunochemistry and RT-PCR

Methods for the detection of central nervous tissue (CNT) are urgently needed in food control as a means for controlling strict adherence to both food labeling and banning of specified BSE risk material. Here, we report data on heat stability of the CNT markers neuron-specific enolase (NSE) in western blotting, glial fibrillary acidic protein (GFAP) in an enzyme linked immunoassay, mRNA(GFAP) in a real-time PCR assay, and several fatty acids (C22:6, C24:0-OH, C24:1ω9/ω7, C24:1ω9-OH/ω7-OH, and C24:0) in gas chromatography mass spectrometry (GC/MS). The sample matrix, a standard material of emulsion-type sausage with varied contents of CNT (brain), was heat-treated in three studies: (1) routine meat technological heat treatment with low (85 °C, 30 min), medium (115 °C, 30 min), and high (133 °C, 30 min, 3 bar) heating of 72 anonymous samples from a blind trial; (2) heat treatment under experimental conditions (100, 110, …, 200 °C, 45 min); and (3) fractionized heating of central nervous system (up to three times) under moderate routine technological conditions (85, 100, and 115 °C, 30 min). The markers of the immunochemical methods showed a low GFAP or very low NSE temperature stability at medium and high temperature conditions. The real-time PCR assay gave inconsistent, non-quantitative results, which indicated an uncontrollable matrix effect. The relevant GC/MS markers (C24:0-OH, C24:1ω9/ω7, and C24:1ω9-OH/ω7-OH) proved to be extremely stable. Neither meat and bone meal conditions (133 °C) nor experimental heating (up to and above 140 °C) showed any reduction of GC/MS CNT quantification. On the contrary, a slight but significant increase was noted over a certain temperature range (120-140 °C) for most fatty acids, possibly due to an improved extractability of the fatty acids. We conclude that a quantitative approach is highly unreliable when using immunochemical methods; moreover, these methods might be basically prone to false-negative results depending on heat treatment and matrix composition. Therefore, antibodies with higher affinity to heat-treated CNT marker epitopes are needed. Relevant amounts of CNT (≥0.5%) in low- and medium-heated products would still be reliably detectable by the GFAP ELISA, which justifies its use as a screening method in official food control. The results obtained by the real-time PCR assay were contradictory to recently published data, indicating a need for further protocol optimization and collaborative trials. Up to date, the analytical approach using GC/MS is the only valid procedure as pertaining to heat stability and quantitative analysis; consequently, it should be recommended as the reference procedure in official food control for CNT detection in heat-treated meat products.

Symptomatic spinal metastases of intracranial glioblastoma: clinical characteristics and pathomechanism relating to GFAP expression

To demonstrate clinical characteristics of symptomatic spinal metastases of intracranial glioblastoma multiforme (GBM) and different spreading mechanisms relating to astrocytic cell differentiation, we present an extraordinary case of a 47-year-old patient with rapid progressive paraplegia due to coincident intramedullary and leptomeningeal dissemination of a supratentorial GBM. Serial biopsies of the intracranial, leptomeningeal, and intramedullary GBM lesions of our patient were analyzed for glial fibrillary acidic protein (GFAP). Furthermore, we present 19 additional cases of intracranial GBM with symptomatic spinal seeding, identified through literature review. GFAP expression was high in intracranial and intramedullary tumors, but low in leptomeningeal dissemination of our patient. Mean patient age was 45 years. Mean interval between identification of spinal metastases and death was 4.5 months. Mean overall survival was 18.6 months. Location of symptomatic spinal metastases was more frequently leptomeningeal (14 cases) than intramedullary (7 cases). The case presented herein supports the hypothesis of higher incidence of low GFAP expression in GBM cells in leptomeningeal manifestations after primary intracranial GBM. Because of the proposed tendency for early leptomeningeal spread from primary tumors with low astrocytic differentiation (low GFAP expression), patients with these tumors should be followed more closely to identify leptomeningeal tumor progression early on. Early identification of leptomeningeal spread could enable these patients to benefit from radiation therapy before they develop severe neurological deficits, which might translate into longer acceptable quality of life for these mostly young patients. This is an important finding, but further prospective studies are needed to verify our observations.

Long-term HIV-1 infection of neural progenitor populations

HIV can reside in the brain for many years. While astrocytes are known to tolerate long-term HIV infection, the potential of other neural cell types to harbour HIV is unclear. To investigate whether HIV can persist in neural progenitor cell populations. A multipotent human neural stem cell line (HNSC.100) was used to compare HIV infection in neural progenitor and astrocyte cell populations. Expression of cellular genes/proteins was analysed by real-time reverse transcriptase PCR, Western blot, immunocytochemistry and flow cytometry. Morphological properties of cells were measured by quantitative fluorescent image analysis. Virus release by cells exposed to HIV-1IIIB was monitored by enzyme-linked immunosorbent assay for Gag. Proviral copy numbers were determined by real-time PCR and early HIV transcripts by reverse transcriptase PCR. Rev activity was determined with a fluorescent-based reporter assay. Progenitor populations differed from astrocyte populations by showing much lower glial fibrillary acidic protein (GFAP) production, higher cell-surface expression of the CXCR4 chemokine receptor, higher Rev activity and distinct cell morphologies. HIV-exposed progenitor cultures released moderate amounts of virus for over 2 months and continued to display cell-associated HIV markers (proviral DNA, early HIV transcripts) during the entire observation period (115 days). Differentiation of HIV-infected progenitor cells to astrocytes was associated with transient activation of virus production. Long-term HIV infection of progenitor populations led to upregulation of GFAP and changes in cell morphology. These studies suggest that neural progenitor populations can contribute to the reservoir for HIV in the brain and undergo changes as a consequence of HIV persistence.

Comparative proteomic analysis with postmortem prefrontal cortex tissues of suicide victims versus controls

Background The origin of suicidal behaviour is multifactorial including genetic, neurobiological and psychosocial correlates. Although there is no doubt that serotonin has a central role, the overall genetic findings with candidate genes of the serotonergic pathway are relatively inconsistent and suggests that other, yet unidentified, genes and gene products are also contributing to the vulnerability of suicidality. Proteomics is a powerful method to investigate modifications in protein expression. Methods We performed comparative proteomic analysis with prefrontal cortex tissues of 17 suicide victims and 9 controls. Results Applying two dimensional gel electrophoresis and image analysis we detected five protein spots to differ significantly in intensities between both groups. Three of them appeared only in suicide victims and could be identified by means of MALDI-TOF-MS analysis and protein database search as α crystallin chain B (CRYAB), glial fibrillary acidic protein (GFAP) and manganese superoxide dismutase (SOD2). CRYAB belongs to the low molecular heat shock proteins and GFAP is known as a marker of astrocytic activation in gliosis. SOD2 is a major antioxidant enzyme protecting cells against oxidative injury. Two further spots revealed higher intensities in the control group but had no unambiguous protein to match. Conclusions Our findings suggest that proteins, being involved in glial function, neurodegeneration and oxidative stress neuronal injury, might also have an impact upon the neurobiological cascade leading to suicidality. As animal data provide evidence for an up-regulation of GFAP synthesis in astrocytes due to alterations in 5-HT levels, similar mechanisms of interaction might also be relevant in humans.

Solid Human Embryonic Spinal Cord Xenografts in Acute and Chronic Spinal Cord Cavities: A Morphological and Functional Study

While therapeutic spinal cord grafting procedures are of interest in the chronic spinal cord injury stage, previous experimental grafting studies, including human spinal cord tissue, have mainly focused on the acute stage. Therefore, solid human embryonic spinal cord grafts were implanted in acute or chronic spinal cord aspiration cavities of immunodeficient rats to compare the morphological and locomotor outcome to that of lesion alone cases. Locomotor function was assessed using the Basso, Beattie, and Bresnahan open-field locomotor rating scale up to 6 months, while the morphological evaluation of graft survival, growth, and integration was performed at 6 weeks or 6 months after implantation. Graft survival was 94% in both lesion models, while graft growth was enhanced in the chronic compared to the acute cavity group. Human specific Thy-1 and neurofilament immunoreactive fibers were observed up to 7 mm into host white matter, while aminergic fibers were observed up to 1 mm into the grafts. Abundant calcitonin gene-related peptide immunoreactive fibers in the grafts in the absence both of immunoreactive cell bodies and colocalized human-specific neurofilament immunoreactivity, suggested host fiber ingrowth. At 6 months, the grafted cases presented less central canal deformation and lower glial fibrillary acidic protein immunoreactivity at the host cavity border compared to that of the nongrafted cases. The strong compensatory regain of locomotor function after unilateral spinal cord lesions was not affected by the human spinal cord grafts. In conclusion, solid human embryonic spinal cord tissue transplanted to a cavity in the adult injured spinal cord results in beneficial morphological effects in both the acute and chronic spinal cord lesion.