The brain is rich in long-chain PUFA, which play an essential role in its development and functions. Here, we examined the impact of maternal n-3 PUFA intake deficiency during gestation and lactation on the development of glial cells in the pup’s developing cerebral cortex. In addition, using myelination as indicator and the anti-myelin basic protein as measurement to establish the relationship between the number of glial fibrillary acidic protein (GFAP)-positive cells and the development of oligodendrocytes, we determined the myelination state of the somatosensory cortex at postnatal day 14. Rat dams were fed either a control (Cont) or an n-3 PUFA-deficient (Def) diet for 60 d (acclimatisation: 14 d; gestation: 21 d; and lactation: 21 d). Pups lactated from dams throughout the experiment. The distribution pattern of astrocytes in pups on postnatal day 7 was immunohistochemically analysed using GFAP and brain lipid binding protein (BLBP) as markers for mature astrocytes and astrocyte-specific radial glial cells, respectively. It was observed that, when compared with Cont pups, GFAP-positive cells decreased, BLBP-positive cells increased and myelinated structures were sparser in the somatosensory cortices of Def pups. In the open field test on postnatal day 21, behavioural parameters did not differ between groups. Our results indicated that inhibited maturation of astrocytes caused by maternal n-3 PUFA deficiency hindered the development of brain glial cells of neonatal rats; hence, maternal n-3 PUFA intake during the gestation and lactation periods may have been crucial for the brain cell composition of pups.

The glial fibrillary acidic protein (GFAP) is an intermediate filament widely used to identify and label astroglial cells, a very abundant and relevant glial cell type in the central nervous system. A major hurdle in studying its behavior and function arises from the fact that GFAP does not tolerate well the addition of protein tags to its termini. Here, we tagged human GFAP (hGFAP) with an enhanced green fluorescent protein (EGFP) for the first time, and substituted a previously reported EGFP tag on mouse GFAP (mGFAP) by a more versatile Halo Tag. Both versions of tagged GFAP were able to incorporate into the normal GFAP filamentous network in glioma cells, and Alexander disease-related mutations or pharmacological disruption of microtubules and actin filaments interfered with GFAP dynamics. These new tools could provide new fruitful venues for the study of GFAP oligomerization, aggregation and dynamics in living cells.

Neonates with critical CHD have evidence, by imaging, of preoperative brain injury, although the timing is unknown. We used circulating postnatal serum glial fibrillary acidic protein as a measure of acute perinatal brain injury in neonates with CHD. Glial fibrillary acidic protein was measured on admission and daily for the first 4 days of life in case and control groups; we included two control groups in this study – non-brain-injured newborns and brain-injured newborns. Comparisons were performed using the Kruskal–Wallis test with Dunn’s multiple comparisons, Student’s t-test, and χ2 test of independence where appropriate. In aggregate, there were no significant differences in overall glial fibrillary acidic protein levels between CHD patients (n=56) and negative controls (n=23) at any time point. By day 4 of life, 7/56 (12.5%) CHD versus 0/23 (0%) normal controls had detectable glial fibrillary acidic protein levels. Although not statistically significant, the 5/10 (50%) left heart obstruction group versus 1/17 (6%) conoventricular, 0/13 (0%) right heart, and 1/6 (17%) septal defect patients trended towards elevated levels of glial fibrillary acidic protein at day 4 of life. Overall, glial fibrillary acidic protein reflected no evidence for significant peripartum brain injury in neonates with CHD, but there was a trend for elevation by postnatal day 4 in neonates with left heart obstruction. This pilot study suggests that methods such as monitoring glial fibrillary acidic protein levels may provide new tools to optimise preoperative care and neuroprotection in high-risk neonates with specific types of CHD.

Limb remote ischemic conditioning (LRIC) provides a physiologic strategy for harnessing the body’s endogenous protective capabilities against injury induced by ischemia–reperfusion in the central nervous system. The aim of the present study was to determine if LRIC played a role in protecting the retina from ischemia–reperfusion injury. A total of 81 adult male Sprague-Dawley rats were randomly assigned to sham and ischemia/reperfusion with or without remote LRIC arms. The retinal ischemic model was generated through right middle cerebral artery occlusion (MCAO) and pterygopalatine artery occlusion for 60 min followed by 1, 3, and 7 days of subsequent reperfusion. LRIC was conducted immediately following MCAO by tightening a tourniquet around the upper thigh and releasing for three cycles. Paraffin sections were stained with hematoxylin and eosin in order to quantify the number of cells in retinal ganglion cells (RGCs) layer throughout the duration of the study. Cellular expression of glial fibrillary acidic protein (GFAP) was detected and examined through immunohistochemistry. Protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was also analyzed by Western blot techniques. Our study demonstrated that the loss of cells in RGC layer was attenuated by LRIC treatment at 3 and 7 days following reperfusion (P < 0.05). Immunohistochemistry studies depicted a gradual increase (P < 0.05) in GFAP levels from day 1 through day 7 following ischemia and subsequent reperfusion, whereas LRIC reduced GFAP levels at 1, 3, and 7 days postreperfusion. In addition, LRIC increased the expression of Nrf2 and HO-1 at day 1 and 3 following ischemia/reperfusion. This particular study is the first remote conditioning study applicable to retinal ischemia. Our results strongly support the position that LRIC may be used as a noninvasive neuroprotective strategy, which provides retinal protection from ischemia–reperfusion injury through the upregulation of antioxidative stress proteins, such as Nrf2 and HO-1.

Objective: To determine whether blood levels of the brain-specific biomarker glial fibrillary acidic protein rise during cardiopulmonary bypass for repair of congenital heart disease. Methods: This is a prospective observational pilot study to characterise the blood levels of glial fibrillary acidic protein during bypass. Children <21 years of age undergoing bypass for congenital heart disease at Johns Hopkins Hospital and Texas Children's Hospital were enrolled. Blood samples were collected during four phases: pre-bypass, cooling, re-warming, and post-bypass. Results: A total of 85 patients were enrolled between October, 2010 and May, 2011. The median age was 0.73 years (range 0.01–17). The median weight was 7.14 kilograms (range 2.2–86.5). Single ventricle anatomy was present in 18 patients (22%). Median glial fibrillary acidic protein values by phase were: pre-bypass: 0 ng/ml (range 0–0.35); cooling: 0.039 (0–0.68); re-warming: 0.165 (0–2.29); and post-bypass: 0.112 (0–0.97). There were significant elevations from pre-bypass to all subsequent stages, with the greatest increase during re-warming (p = 0.0001). Maximal levels were significantly related to younger age (p = 0.03), bypass time (p = 0.03), cross-clamp time (p = 0.047), and temperature nadir (0.04). Peak levels did not vary significantly in those with single ventricle anatomy versus two ventricle repairs. Conclusion: There are significant increases in glial fibrillary acidic protein levels in children undergoing cardiopulmonary bypass for repair of congenital heart disease. The highest values were seen during the re-warming phase. Elevations are significantly associated with younger age, bypass and cross-clamp times, and temperature nadir. Owing to the fact that glial fibrillary acidic protein is the most brain-specific biomarker identified to date, it may act as a rapid diagnostic marker of brain injury during cardiac surgery.

Taurine immunoreactivity (IR) in 1 -μm sections of glutaraldehyde-fixed human optic nerve was observed using light microscopy and an antibody raised in rabbit to taurine conjugated to bovine serum albumin. Throughout the nerve, taurine-lR was prominent in glial cells, in their perinuclear regions, and in their numerous branching processes, some of which extended to the pial septa. The peripheral glial mantle (glia limitans) was densely stained, whereas axons and the pial septa showed relatively little or no taurine-IR. Immunoreactivity for glial fibrillary acidic protein (GFAP), an astrocyte-specific marker, was evaluated on adjacent sections. The pattern of GFAP-IR was highly similar to that for taurine, suggesting that a subset of taurine-immunoreactive glial cells are optic nerve astrocytes. To our knowledge, this is the first localization of taurine and GFAP in human optic nerve.

The immunohistochemical location of glial fibrillary acidic protein (GFAP) was used to study the state of maturation of retinal astrocytes from an 18-mo-old infant and to compare it with the situation in the adult. Infant astrocytes showed intense GFAP immunoreactivity in the perikarya and possessed spindle-like enlargements in their processes, while in the adult immunoreactivity in the perikarya was scarce and the spindle-like enlargements were not evident. Two types of astrocyte were observed in adult and child retinas: elongated and star-shaped. In the adult, the star-shaped type tend to be more stylised and to have longer processes than in the infant. In the infant, numerous astrocyte cell bodies were observed over vessels, while in the adult these were scarce. In the infant, the star-shaped astrocytes made up a honeycomb plexus, but this was not fully developed. These results suggest that at 18 mo of postnatal development the retinal astrocytes are still increasing and growing into the astroglial structure found in adults.

Immunohistochemical study of major salivary gland tumours was performed on 60 pleomorphic adenomas, five basal cell adenomas and 10 adenoid cystic carcinomas to determine the diagnostic value of each antigen. Immunoreactivity examined were intermediate filaments (keratin, vimentin, desmin and glial fibrillary acidic protein [GFAP]) and related substances (actin, S-100 protein and secretory component). In pleomorphic adenomas, there was positive immunoreactivity for GFAP which was not observed in normal tissue or other neoplastic tissues. Immunoreactivity of GFAP was closely related to myxomatous and early chondromatous differentiation in pleomorphic adenoma. It is considered that GFAP immunoreactivity should be assessed in the occasional differential diagnostic dilemma of pleomorphic adenoma versus adenoid cystic carcinoma and basal cell adenoma, because of its ability to show potential and definite myxochondromatous differentiation.