Cardiac-specific methylation patterns of circulating DNA for identification of cardiomyocyte death.

BACKGROUND: Correct detection of human cardiomyocyte death is essential for definitive diagnosis and appropriate management of cardiovascular diseases. Although current strategies have proven utility in clinical cardiology, they have some limitations. Our aim was to develop a new approach to monitor myocardial death using methylation patterns of circulating cell-free DNA (cf-DNA). METHODS: We first examined the methylation status of FAM101A in heart tissue and blood of individual donors using quantitative methylation-sensitive PCR (qMS-PCR). The concentrations and kinetics of cardiac cf-DNA in plasma from five congenital heart disease (CHD) children before and after they underwent cardiac surgery at serial time points were then investigated. RESULTS: We identified demethylated FAM101A specifically present in heart tissue. Importantly, our time course experiments demonstrated that the plasma cardiac cf-DNA level increased quickly during the early post-cardiac surgery phase, peaking at 4-6 h, decreased progressively (24 h) and returned to baseline (72 h). Moreover, cardiac cf-DNA concentrations pre- and post-operation were closely correlated with plasma troponin levels. CONCLUSIONS: We proposed a novel strategy for the correct detection of cardiomyocyte death, based on analysis of plasma cf-DNA carrying the cardiac-specific methylation signature. Our pilot study may lead to new tests for human cardiac pathologies.

Role of rno-miR-124-3p in regulating MCT1 expression in rat brain after permanent focal cerebral ischemia.

This study aimed to assess the role of microRNAs (miRNAs) in regulating monocarboxylate transporter-1 (MCT1) expression in rat brain after permanent focal cerebral ischemia to identify a new target for early treatment of cerebral ischemia. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (pMCAO) in rats. Morphology and protein expression levels of MCT1 were assessed by immunofluorescence and Western blotting. Using bioinformatics and double luciferase reporter assays, rno-miR-124-3p was selected as a direct target for rat MCT1. Expression of rno-miR-124-3p after pMCAO was detected. Then, rats were treated with rno-miR-124-3p agomir via lateral ventricle injection, and after 6 h or 24 h ischemia, rno-miR-124-3p expression and gene and protein expression of MCT-1 were detected by qRT-PCR and Western blotting. Brain infarction was identified by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Results showed that pMCAO induced brain infarction and increased the expression of MCT1. The levels of rno-miR-124-3p after pMCAO were in contrast to those of MCT1 protein in ischemic region, while declined after 3, 6 and 12 h of pMCAO in ischemic penumbra. After administration of rno-miR-124-3p agomir, MCT1 mRNA and protein levels were increased after 6 h of pMCAO, while decreased after 24 h of pMCAO. Meanwhile, rno-miR-124-3p levels increased after both times. TTC staining showed treatment with rno-miR-124-3p agomir reduced brain infarction. The role of rno-miR-124-3p in regulating MCT1 was as a positive regulator after 6 h of pMCAO, while a negative regulator after 24 h of pMCAO, however, both activities had protective effects against cerebral ischemia.

Curcumin Ameliorates Memory Deficits by Enhancing Lactate Content and MCT2 Expression in APP/PS1 Transgenic Mouse Model of Alzheimer's Disease.

Curcumin is a natural product with several anti-Alzheimer's disease (AD) neuroprotective properties. This study aimed to investigate the effects of curcumin on memory deficits, lactate content, and monocarboxylate transporter 2 (MCT2) in APP/PS1 mouse model of AD. APP/PS1 transgenic mice and wild-type (WT) C57BL/6J mice were used in the present study. Spatial learning and memory of the mice was detected using Morris water-maze test. Cerebral cortex and hippocampus lactate contents were detected using lactate assay. MCT2 expression in the cerebral cortex and hippocampus was examined by immunohistochemistry and Western blotting. Results showed that spatial learning and memory deficits were improved in curcumin-treated APP/PS1 mouse group compared with those in APP/PS1 mice group. Brain lactate content and MCT2 protein level were increased in curcumin-treated APP/PS1 mice than in APP/PS1 mice. In summary, our findings indicate that curcumin could ameliorate memory impairments in APP/PS1 mouse model of AD. This phenomenon may be at least partially due to its improving effect on the lactate content and MCT2 protein expression in the brain. Anat Rec, 302:332-338, 2019. © 2018 Wiley Periodicals, Inc.

An applied anatomical study of bronchial artery.

The aim of this study was to reveal the external features of the bronchial artery (BA) system, so as to provide morphological basis for clinic. The BAs in 48 adult cadavers were dissected and analyzed. The number of BAs in 48 cases was 118. The incidence of BA arising from thoracic aorta, right posterior intercostal artery, and right subclavian artery was 69.49, 27.12, and 3.39%, respectively. The origin of BAs in individual specimen might be single, two, or all of them, respectively. According to the different origin and/or origins of BAs, it could be divided into five categories. As for the course of BAs, in this study, all the left BAs arising from thoracic aorta passed forward around the left side of esophagus and then entered left pulmonary hilum; most (n = 15) of the right BAs arising from thoracic aorta passed forward around the left side of esophagus and then entered right pulmonary hilum; a few (n = 8) of the right BAs arising from thoracic passed forward the right side of esophagus and bronchus and then entered right pulmonary hilum. Besides, in our group, the special courses were that right intercostal-bronchial trunk (RICBT) arising from thoracic aorta passed between vertebra and esophagus and gave off BA which curved forward around the right side of esophagus and then entered right pulmonary hilum, common bronchial trunk (CBT) arising from thoracic aorta passed forward around the left side of esophagus laying anterior to bronchus or posterior to bronchus, then dividing into a left and a right BAs entering right and left pulmonary hilum, respectively. In 4 cadavers, the RICBT gave off the radiculomedullary artery and BA in turn, so radiculomedullary artery has the same origin with BA. Of all BAs, the mean diameter of right posterior intercostal artery, CBT, left BA, and right BA was 2.17 ± 0.84, 1.79 ± 0.57, 1.44 ± 0.50, and 1.39 ± 0.38 mm, respectively. The information gained from this study will be of value in clinic application.

p53-Mediated oligodendrocyte apoptosis initiates demyelination after compressed spinal cord injury by enhancing ER-mitochondria interaction and E2F1 expression.

Oligodendrocyte apoptosis mediated demyelination is a pathological change characteristic of compressed spinal cord injury (CSCI). However, the mechanism of demyelination due to oligodendrocyte apoptosis is not known. In this study, after successfully establishing a rat CSCI model using a custom-made compressor, we investigated the pathological changes, MBP expression, as well as apoptosis-related protein (p53, active caspase-3) expression to determine whether or not apoptosis and demyelination occurred after injury. To understand the possible mechanism of oligodendrocyte apoptosis, caspase-12 and cytochrome C were analyzed to explore the relationship between oligodendrocyte apoptosis and endoplasmic reticulum(ER)-mitochondria interaction. The transcription factor, E2F1, was also detected by immunofluorescence and Western blot assays. The results showed that CSCI increased the expression levels of p53, E2F1 and active caspase-3 followed by the swelling and breakdown of myelin sheaths. The number of myelinated nerve fibers also decreased with down-regulated expression of MBP. Expression levels of caspase-12 and cytochrome C were enhanced along with a reduction in the number of oligodendrocytes. After treatment of CSCI in rats with Pifithrin-µ(PFT-µ), a specific inhibitor of p53, pathomorphological changes of myelin sheath improved significantly. Expression levels of E2F1, active caspase-3, caspase-12 and cytochrome C were down-regulated, consistent with reduced the number of apoptotic oligodendrocytes. These results demonstrated that over-expression of p53 could mediate oligodendrocyte apoptosis thus resulting in demyelination in two ways; by enhancing ER-mitochondria interaction and by triggering the E2F1 mediated apoptosis pathway.

Anatomical Characteristics and Biomechanical Properties of the Oblique Popliteal Ligament.

This anatomical study sought to investigate the morphological characteristics and biomechanical properties of the oblique popliteal ligament (OPL). Embalmed cadaveric knees were used for the study. The OPL and its surrounding structures were dissected; its morphology was carefully observed, analyzed and measured; its biomechanical properties were investigated. The origins and insertions of the OPL were relatively similar, but its overall shape was variable. The OPL had two origins: one originated from the posterior surface of the posteromedial tibia condyle, merged with fibers from the semimembranosus tendon, the other originated from the posteromedial part of the capsule. The two origins converged and coursed superolaterally, then attached to the fabella or to the tendon of the lateral head of the gastrocnemius and blended with the posterolateral joint capsule. The OPL was classified into Band-shaped, Y-shaped, Z-shaped, Trident-shaped, and Complex-shaped configurations. The mean length, width, and thickness of the OPL were 39.54, 22.59, and 1.44 mm, respectively. When an external rotation torque (18 N·m) was applied both before and after the OPL was sectioned, external rotation increased by 8.4° (P = 0.0043) on average. The OPL was found to have a significant role in preventing excessive external rotation and hyperextension of the knee.

Lost Polarization of Aquaporin4 and Dystroglycan in the Core Lesion after Traumatic Brain Injury Suggests Functional Divergence in Evolution.

OBJECTIVE: To understand how aquaporin4 (AQP4) and dystroglycan (DG) polarized distribution change and their roles in brain edema formation after traumatic brain injury (TBI). METHODS: Brain water content, Evans blue detection, real-time PCR, western blot, and immunofluorescence were used. RESULTS: At an early stage of TBI, AQP4 and DG maintained vessel-like pattern in perivascular endfeet; M1, M23, and M1/M23 were increased in the core lesion. At a later stage of TBI, DG expression was lost in perivascular area, accompanied with similar but delayed change of AQP4 expression; expression of M1, M23, and DG and the ratio of M1/M2 were increased. CONCLUSION: At an early stage, AQP4 and DG maintained the polarized distribution. Upregulated M1 and M23 could retard the cytotoxic edema formation. At a later stage AQP4 and DG polarized expression were lost from perivascular endfeet and induced the worst cytotoxic brain edema. The alteration of DG expression could regulate that of AQP4 expression after TBI.

Internalization of aquaporin-4 after collagenase-induced intracerebral hemorrhage.

Brain edema formation following intracerebral hemorrhage (ICH) appears to be related with aquaporin-4 (AQP4), which is critically involved in brain volume homeostasis and water balance. Despite its importance, the regulation of AQP4 expression involved in transmembrane water movements still remains rudimentary. Many studies suggest that the internalization of several membrane-bound proteins, including AQP4, may occur with or without lysosomal degradation. Previously, we investigated the internalization of AQP4 in retinal ischemic-reperfusion model. Here, we test the hypothesis that AQP4 is internalized post-ICH and then degraded in the lysosome. The results demonstrated that both AQP4 and the mannose-6-phosphate receptor (MPR) co-localized in perihematomal region at 6 hr post-ICH. In addition, AQP4 and lysosomal-associated membrane protein 1 (LAMP1) also co-localized in perihematomal region, with co-expression increasing followed by a gradual decrease at different time windows post-ICH (6, 12, 24, 48, and 72 hr). After ICH, the Evans blue leakage happened very early at 1 hr and the brain swelling occurred at 3 hr. Moreover, we also found the AQP4 mRNA and AQP4 protein were increased post-ICH. These results suggest that AQP4 is internalized and the lysosome is involved in degrading the internalized AQP4 post-ICH. Both the AQP4 internalization and lysosomal degradation may provide biophysical insights regarding the potential of new treatments for brain edema.

Loss of AQP4 polarized localization with loss of ß-dystroglycan immunoreactivity may induce brain edema following intracerebral hemorrhage.

The aquaporin-4 (AQP4) water channel contributes to brain water homeostasis in perivascular and subpial membrane domains of astrocytes where it is concentrated. These membranes form the interface between the neuropil and the extracellular liquid spaces. The brain-selective deletion of the dystroglycan (DG) gene causes a disorganization of AQP4 on the astroglial endfeet. First, we analyzed the expression of AQP4, ß-DG in the brain following intracerebral hemorrhage (ICH) and correlated AQP4 expression with the expression pattern of the ß-DG, which is a component of dystrophin-dystroglycan complex (DDC). Besides, the vessels ultrastructure and brain water content were investigated at different time points post-ICH (day 1, day 3, day 7). We found that AQP4 polarity was disturbed in parallel with the loss of ß-DG in the perihematomal area post-ICH. At day 1 post-ICH, brain edema was obvious and the damage of vascular ultrastructure was the most severe. These results suggest a role for ß-DG in targeting and stabilizing AQP4 channel in astrocytic cells, which may be critical for water homeostasis in brain.

An applied anatomical study on the external laryngeal nerve loop and the superior thyroid artery in the neck surgical region.

This study was conducted to investigate the topographic relationship between the external laryngeal nerve (ELN) loop and the superior thyroid artery (STA), in order to provide the anatomical foundations for protecting the ELN during surgery. In the present study, 48 adult human cadavers were dissected and analyzed. For the 21 (21.9%) low-position ELN loops observed, the neurovascular relationship between the STA and the nerve was classified into four types: (1) the artery overlapped the nerve; (2) the artery passed through the ELN loop; (3) the muscular branch of the ELN loop and the laryngeal branch of the STA coursed together; and (4) the branches of the STA and the ELN loop were interlaced. Our study suggested that the patterns of ELN loops are so complicated that they have not been statistically defined in any previous study, which should be kept in mind when attempting to protect the nerve from injury. Also, because of the variable morphology of the ELN loop and its complicated topographic relationship to the STA, the vessels should be individually isolated and then ligated during thyroidectomy. When ligating the laryngeal branch of the STA during larynx surgery, special attention should be paid to avoiding damage to the muscular branch of the ELN/ELN loop.

Upregulation and lysosomal degradation of AQP4 in rat brains with bacterial meningitis.

Brain edema is among the major complications in children with bacterial meningitis. Aquaporins are integral membrane pore proteins that form channels to regulate cellular water content. Aquaporin-4 (AQP4), which is enriched in parts of astrocytic membranes that are apposed to pial or perivascular basal laminae, is the predominant aquaporin in the central nervous system. Dystroglycan is among the proteins that are responsible for the site-specific anchorage of AQP4. To elucidate the role of AQP4 in the development of brain edema induced by meningitis, a model of bacterial meningitis was established by injecting group B ß-hemolytic Streptococci into the cerebrospinal fluid of three-week-old rats. The brain water content increased in this model compared with that in the control group. The expression of AQP4 and dystroglycan was examined by Western blot and the degradation route of AQP4 was investigated by double immunofluorescence labeling. Western blot results showed that the expression of AQP4 and dystroglycan in rat brain increased in the meningitis model. Meanwhile, AQP4 was co-localized with the marker of lysosome in this model, indicating that the lysosome is involved in AQP4 degradation.

Demyelination initiated by oligodendrocyte apoptosis through enhancing endoplasmic reticulum-mitochondria interactions and Id2 expression after compressed spinal cord injury in rats.

BACKGROUND: Demyelination is one of the most important pathological factors of spinal cord injury. Oligodendrocyte apoptosis is involved in triggering demyelination. However, fewer reports on pathological changes and mechanism of demyelination have been presented from compressed spinal cord injury (CSCI). The relative effect of oligodendrocyte apoptosis on CSCI-induced demyelination and the mechanism of apoptosis remain unclear. AIMS: In this study, a custom-designed model of CSCI was used to determine whether or not demyelination and oligodendrocyte apoptosis occur after CSCI. The pathological changes in axonal myelinated fibers were investigated by osmic acid staining and transmission electron microscopy. Myelin basic protein (MBP), which is used in myelin formation in the central nervous system, was detected by immunofluorescence and Western blot assays. Oligodendrocyte apoptosis was revealed by in situ terminal-deoxytransferase-mediated dUTP nick-end labeling. To analyze the mechanism of oligodendrocyte apoptosis, we detected caspase-12 [a representative of endoplasmic reticulum (ER) stress], cytochrome c (an apoptotic factor and hallmark of mitochondria), and inhibitor of DNA binding 2 (Id2, an oligodendrocyte lineage gene) by immunofluorescence and Western blot assays. RESULTS: The custom-designed model of CSCI was successfully established. The rats were spastic, paralyzed, and incontinent. The Basso, Beattie, and Bresnahan (BBB) locomotor rating scale scores were decreased as time passed. The compressed spinal cord slices were ischemic. Myelin sheaths became swollen and degenerative; these sheaths were broken down as time passed after CSCI. MBP expression was downregulated after CSCI and consistent with the degree of demyelination. Oligodendrocyte apoptosis occurred at 1 day after CSCI and increased as caspase-12 expression was enhanced and cytochrome c was released. Id2 was distributed widely in the white matter. Id2 expression increased with time after CSCI. CONCLUSION: Demyelination occurred after CSCI and might be partly caused by oligodendrocyte apoptosis, which was positively correlated with ER-mitochondria interactions and enhanced Id2 expression after CSCI in rats.

The internalization and lysosomal degradation of brain AQP4 after ischemic injury.

The membrane-bound water channel aquaporin-4 (AQP4) plays a significant role in maintaining brain water homeostasis. In ischemic brain, changes in the expression level of AQP4 have been reported. Previous studies suggest that the internalization of several membrane-bound proteins, including AQP4, may occur with or without lysosomal degradation. In this study, the internalization of AQP4 was detected in the ischemic rat brain via double immunofluorescence labeling. Specifically, AQP4 and early endosome antigen-1 (EEA1) co-localized after 1 h post-ischemic injury. Moreover, the co-expression of AQP4 and lysosomal-associated membrane protein-1 (LAMP1) was observed after 3 h post-ischemia. These findings suggest that AQP4 is internalized and the lysosome is involved in degrading the internalized AQP4 in the ischemic brain. AQP4 is known to be downregulated by the protein kinase C activator phorbol 12-myristate 13-acetate (PMA) in vivo and in vitro. The results in this study displayed that PMA infusion could decrease brain edema accompanied by AQP4 downregulation in ischemic brain. However, compared with vehicle infusion, PKC activator infusion did not increase the ratio of internalized or lysosomal degraded AQP4. That is, we have not found out evidence to prove protein kinase C activator PMA can promote the internalization or lysosomal degradation of AQP4 in the ischemic brain.

Expression of aquaporin8 in human astrocytomas: correlation with pathologic grade.

Aquaporin8 (AQP8), a member of the aquaporin (AQP) protein family, is weakly distributed in mammalian brains. Previous studies on AQP8 have focused mainly on the digestive and the reproductive systems. AQP8 has a pivotal role in keeping the fluid and electrolyte balance. In this study, we investigated the expression changes of AQP8 in 75 cases of human brain astrocytic tumors using immunohistochemistry, Western blotting, and reverse transcription polymerase chain reaction. The results demonstrated that AQP8 was mainly distributed in the cytoplasm of astrocytoma cells. The expression levels and immunoreactive score of AQP8 protein and mRNA increased in low-grade astrocytomas, and further increased in high-grade astrocytomas, especially in glioblastoma. Therefore, AQP8 may contribute to the proliferation of astrocytomas, and may be a biomarker and candidate therapy target for patients with astrocytomas.

Hyperosmotic induction of aquaporin expression in rat astrocytes through a different MAPK pathway.

Water homeostasis of the nervous system is important during neural signal transduction. Astrocytes are crucial in water transport in the central nervous system under both physiological and pathological conditions. To date, five aquaporins (AQP) have been found in rat brain astrocytes. Most studies have focused on AQP4 and AQP9, however, little is known about the expression of AQP3, -5, and -8 as well as their regulating mechanism in astrocytes. The expression patterns of AQP3, -5, and -8 in astrocytes exposed to hyperosmotic solutions were examined to clarify the roles of AQP3, -5, and -8 in astrocyte water movement. The expression of AQP4 and AQP9 under the same hyperosmotic conditions was also investigated. The AQP4 and AQP9 expressions continuously increased until 12 h after hyperosmotic solution exposure, whereas the AQP3, -5, and -8 expressions continued to increase until 6 h after hyperosmotic solution exposure. The different AQPs decreased at corresponding time points (24 h for AQP4 and AQP9; 12 h for AQP3, -5, and -8 after hyperosmotic solution exposure). The ERK inhibitor can attenuate the expression of AQP3, -5, and -8 after hyperosmotic solution exposure. The p38 inhibitor can inhibit the AQP4 and AQP9 expressions in cultured astrocytes. AQP expression is directly related to the extracellular hyperosmotic stimuli. Moreover, different AQPs can be regulated by a distinct MAPK signal transduction pathway.

Superior laryngeal nerve loop: patterns and surgical implications.

This study clarifies the patterns of the superior laryngeal nerve loop (SLN loop), connecting the cervical sympathetic chain (CSC) and the SLN and its branches, so as to provide an anatomic basis for decreasing the risk of injury to the external laryngeal nerve (ELN) during neck surgery. Fifty Chinese adult human cadavers fixed with 4 % formalin were dissected, and their SLN loop patterns were analyzed and summarized. In 98 of 100 sides the CSC anastomosed with the SLN and its branches, forming a looped nerve structure which we called the SLN loop. The SLN loops could be divided into five types: e ( n ), t ( n ), i ( n ), t ( n ) e ( n ), and i ( n ) e ( n ) based on morphological variations. The results demonstrated that e ( n ) was most frequently found in the samples (82/100) followed by t ( n ) (9/100), i ( n ) (3/100), t ( n ) e ( n ) (2/100), and i ( n ) e ( n ) (2/100). Comparing with the previous work, we identified additional 18 subtypes of the SLN loop. The relations of the SLN loop to the surrounding structures were complicated, which brought more challenges to thyroidectomy. Thus, we do not advocate routine identification of ELN/ELN loop during the process of thyroidectomy, especially systematic identification of ELN during operation. However, this study introduces the possibility that nerve injury can be avoided by exposure of the nerve via careful dissection in the region of the superior pole of the thyroid gland to the extent that we can initiate individual ligation of the superior polar vessels, along with the help of neuromonitors, video monitors, and magnifying loupes.

Lysosomal degradation of retinal glial AQP4 following its internalization induced by acute ocular hypertension.

The membrane-bound water channel aquaporin-4 plays a significant role in the regulation of water movement within the retina. In retinal ischemia-reperfusion injury, changes in the expression and localization of aquaporin-4 have been reported. Previous studies also suggest that the internalization of several membrane-bound proteins, including aquaporin-4, may occur with or without lysosomal degradation. In this study, the internalization of aquaporin-4 was detected in the ischemic rat retina via double immunofluorescence labeling. Specifically, both aquaporin-4 and the mannose-6-phosphate receptor co-localized post-ischemic injury (10, 30 and 60 min). The same results were found during a 12-h reperfusion window (2, 4 and 8 h, respectively) following 60 min of ischemia. Moreover, the co-expression of aquaporin-4 and lysosomal-associated membrane protein-1 was observed at 1-12 h of reperfusion, with co-expression increasing followed by a gradual decrease. These combined findings suggest that AQP4 is internalized in the ischemic-reperfused retina, and the lysosome is involved in degrading the internalized aquaporin-4 during the reperfusion phase. Both the internalization of aquaporin-4 and its lysosomal degradation may serve as valuable therapeutic targets for managing ischemic-reperfused retinal injury.

Aquaporin 9 in rat brain after severe traumatic brain injury.

OBJECTIVE: To reveal the expression and possible roles of aquaporin 9 (AQP9) in rat brain, after severe traumatic brain injury (TBI). METHODS: Brain water content (BWC), tetrazolium chloride staining, Evans blue staining, immunohistochemistry (IHC), immunofluorescence (IF), western blot, and real-time polymerase chain reaction were used. RESULTS: The BWC reached the first and second (highest) peaks at 6 and 72 hours, and the blood brain barrier (BBB) was severely destroyed at six hours after the TBI. The worst brain ischemia occurred at 72 hours after TBI. Widespread AQP9-positive astrocytes and neurons in the hypothalamus were detected by means of IHC and IF after TBI. The abundance of AQP9 and its mRNA increased after TBI and reached two peaks at 6 and 72 hours, respectively, after TBI. CONCLUSIONS: Increased AQP9 might contribute to clearance of excess water and lactate in the early stage of TBI. Widespread AQP9-positive astrocytes might help lactate move into neurons and result in cellular brain edema in the later stage of TBI. AQP9-positive neurons suggest that AQP9 plays a role in energy balance after TBI.

Aquaporin 9 in rat brain after severe traumatic brain injury / Aquaporina 9 em cérebro de rato após traumatismo cerebral grave

OBJECTIVE: To reveal the expression and possible roles of aquaporin 9 (AQP9) in rat brain, after severe traumatic brain injury (TBI). METHODS: Brain water content (BWC), tetrazolium chloride staining, Evans blue staining, immunohistochemistry (IHC), immunofluorescence (IF), western blot, and real-time polymerase chain reaction were used. RESULTS: The BWC reached the first and second (highest) peaks at 6 and 72 hours, and the blood brain barrier (BBB) was severely destroyed at six hours after the TBI. The worst brain ischemia occurred at 72 hours after TBI. Widespread AQP9-positive astrocytes and neurons in the hypothalamus were detected by means of IHC and IF after TBI. The abundance of AQP9 and its mRNA increased after TBI and reached two peaks at 6 and 72 hours, respectively, after TBI. CONCLUSIONS: Increased AQP9 might contribute to clearance of excess water and lactate in the early stage of TBI. Widespread AQP9-positive astrocytes might help lactate move into neurons and result in cellular brain edema in the later stage of TBI. AQP9-positive neurons suggest that AQP9 plays a role in energy balance after TBI.

OBJETIVO: Revelar a expressão e os possíveis papéis da aquaporina 9 (AQP9) no cérebro de ratos após lesão cerebral traumática (LCT) grave. MÉTODOS: Foram utilizados: determinação do conteúdo cerebral de água, corante cloreto de tetrazólio, corante azul de Evans, imunoistoquímica (IHQ), imunofluorescência (IF), western blot e PCR em tempo real. RESULTADOS: O conteúdo cerebral de água alcançou o primeiro e o segundo (o mais alto) picos após 6 e 72 horas. A função da barreira hematoencefálica se mostrou muito prejudicada após 6 horas da LCT. A pior isquemia cerebral ocorreu após 72 horas da LCT. Astrócitos AQP9 positivos e neurônios no hipotálamo foram detectados difusamente pela IHQ e IF após LCT. A abundância de AQP9 e de sua mRNA aumentou após LCT e alcançou dois picos após 6 e 72 horas, respectivamente, da LCT. CONCLUSÕES: AQP9 aumentada pode contribuir para a eliminação de água e lactato em excesso na fase precoce da LCT. Astrócitos difusamente localizados AQP9 positivos podem ajudar a entrada do lactato nos neurônios, promovendo edema cerebral celular na fase tardia da LCT. Neurônios AQP9 positivos sugerem que AQP9 tem um papel no equilíbrio energético após LCT.