Neuroprotective Effects of Serpina3k in Traumatic Brain Injury

Integrated Bioinformatics-Based Identification and Validation of Neuroinflammation-Related Hub Genes in Primary Open-Angle Glaucoma

Glaucoma is a leading cause of permanent blindness, affecting 80 million people worldwide. Recent studies have emphasized the importance of neuroinflammation in the early stages of glaucoma, involving immune and glial cells. To investigate this further, we used the GSE27276 dataset from the GEO (Gene Expression Omnibus) database and neuroinflammation genes from the GeneCards database to identify differentially expressed neuroinflammation-related genes associated with primary open-angle glaucoma (POAG). Subsequently, these genes were submitted to Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes for pathway enrichment analyses. Hub genes were picked out through protein-protein interaction networks and further validated using the external datasets (GSE13534 and GSE9944) and real-time PCR analysis. The gene-miRNA regulatory network, receiver operating characteristic (ROC) curve, genome-wide association study (GWAS), and regional expression analysis were performed to further validate the involvement of hub genes in glaucoma. A total of 179 differentially expressed genes were identified, comprising 60 upregulated and 119 downregulated genes. Among them, 18 differentially expressed neuroinflammation-related genes were found to overlap between the differentially expressed genes and neuroinflammation-related genes, with six genes (SERPINA3, LCN2, MMP3, S100A9, IL1RN, and HP) identified as potential hub genes. These genes were related to the IL-17 signaling pathway and tyrosine metabolism. The gene-miRNA regulatory network showed that these hub genes were regulated by 118 miRNAs. Notably, GWAS data analysis successfully identified significant single nucleotide polymorphisms (SNPs) corresponding to these six hub genes. ROC curve analysis indicated that our genes showed significant accuracy in POAG. The expression of these genes was further confirmed in microglia, Müller cells, astrocytes, and retinal ganglion cells in the Spectacle database. Moreover, three hub genes, SERPINA3, IL1R1, and LCN2, were validated as potential diagnostic biomarkers for high-risk glaucoma patients, showing increased expression in the OGD/R-induced glaucoma model. This study suggests that the identified hub genes may influence the development of POAG by regulation of neuroinflammation, and it may offer novel insights into the management of POAG.

Transplantation of astrocyte-derived mitochondria into injured astrocytes has a protective effect following stretch injury

Traumatic brain injury (TBI) is a global public-health problem. Astrocytes, and their mitochondria, are important factors in the pathogenesis of TBI-induced secondary injury. Mitochondria extracted from healthy tissues and then transplanted have shown promise in models of a variety of diseases. However, the effect on recipient astrocytes is unclear. Here, we isolated primary astrocytes from newborn C57BL/6 mice, one portion of which was used to isolate mitochondria, and another was subjected to stretch injury (SI) followed by transplantation of the isolated mitochondria. After incubation for 12 h, cell viability, mitochondrial dysfunction, calcium overload, redox stress, inflammatory response, and apoptosis were improved. Live-cell imaging showed that the transplanted mitochondria were incorporated into injured astrocytes and fused with their mitochondrial networks, which was in accordance with the changes in the expression levels of markers of mitochondrial dynamics. The astrocytic IKK/NF-κB pathway was decelerated whereas the AMPK/PGC-1α pathway was accelerated by transplantation. Together, these results indicate that exogenous mitochondria from untreated astrocytes can be incorporated into injured astrocytes and fuse with their mitochondrial networks, improving cell viability by ameliorating mitochondrial dysfunction, redox stress, calcium overload, and inflammation.

Age-related changes after intracerebral hemorrhage: a comparative proteomics analysis of perihematomal tissue

The risk factors and causes of intracerebral hemorrhage (ICH) and the degree of functional recovery after ICH are distinct between young and elderly patients. The increasing incidence of ICH in young adults has become a concern; however, research on the molecules and pathways involved ICH in subjects of different ages is lacking. In this study, tandem mass tag (TMT)-based proteomics was utilized to examine the protein expression profiles of perihematomal tissue from young and aged mice 24 h after collagenase-induced ICH. Among the 5,129 quantified proteins, ICH induced 108 and 143 differentially expressed proteins (DEPs) in young and aged mice, respectively; specifically, there were 54 common DEPs, 54 unique DEPs in young mice and 89 unique DEPs in aged mice. In contrast, aging altered the expression of 58 proteins in the brain, resulting in 39 upregulated DEPs and 19 downregulated DEPs. Bioinformatics analysis indicated that ICH activated different proteins in complement pathways, coagulation cascades, the acute phase response, and the iron homeostasis signaling pathway in mice of both age groups. Protein-protein interaction (PPI) analysis and ingenuity pathway analysis (IPA) demonstrated that the unique DEPs in the young and aged mice were related to lipid metabolism and carbohydrate metabolism, respectively. Deeper paired-comparison analysis demonstrated that apolipoprotein M exhibited the most significant change in expression as a result of both aging and ICH. These results help illustrate age-related protein expression changes in the acute phase of ICH.

Use of the traditional Chinese medicine "compound healthy ear agent" to protect against age-related hearing loss in mice: A proteomics study

Background

Previous studies have shown that the traditional Chinese medicine (TCM) called "compound healthy ear agent" (CHEA) had anti-apoptosis effects in cochlear hair cells and spiral ganglion neurons, and could protect mice hearing against presbycusis or age-related hearing loss (AHL), as well as aminoglycoside antibiotic-induced ototoxicity. Because its mechanisms of action are still unclear, we investigated the mechanism of action of CHEA against AHL in mice using proteomics techniques.

Methods

Eighteen C57BL/6J mice at 1 month of age were randomly divided into three groups: (A) drinking water until 2 months of age, K2M); (B) drinking water until 7 months of age to induce AHL, K7M; (C) drinking water containing CHEA daily until 7 months of age as treatment group, Z7M. At 2 or 7 months mice were sacrificed and their cochleae were removed for proteomics analysis.

Results

The numbers of proteins with a false discovery rate (FDR) < 1% were respectively 5873 for qualitative and 5492 for quantitative statistics. The numbers of proteins with differential enrichment at least 1.5-fold (p < 0.05) were respectively 351 for K7M vs K2M groups, 52 for Z7M vs K7M groups, 264 for Z7M vs K2M groups. The differentially expressed proteins in the Z7M group were involved in synaptic molecular transmission, energy metabolism, immune response, antioxidant defenses, and anti-apoptosis.

Conclusion

The TCM CHEA played a protective role against AHL in mice by regulating the expression of specific proteins and genes in cochlear hair cells and spiral ganglion neurons. Besides the pathways expected to be involved (antioxidant and anti-apoptosis), proteins related to immune response is a new finding of the present study.

In vitro assessment of protamine toxicity with neural cells, its therapeutic potential to counter chondroitin sulfate mediated neuron inhibition, and its effects on reactive astrocytes

Multiple therapies have been studied to ameliorate the neuroinhibitory cues present after traumatic injury to the central nervous system. Two previous in vitro studies have demonstrated the efficacy of the FDA-approved cardiovascular therapeutic, protamine (PRM), to overcome neuroinhibitory cues presented by chondroitin sulfates; however, the effect of a wide range of PRM concentrations on neuronal and glial cells has not been evaluated. In this study, we investigate the therapeutic efficacy of PRM with primary cortical neurons, hippocampal neurons, mixed glial cultures, and astrocyte cultures. We show the threshold for PRM toxicity to be at or above 10 μg/ml depending on the cell population, that 10 μg/ml PRM enables neurons to overcome the inhibitory cues presented by chondroitin sulfate type A, and that soluble PRM allows neurons to more effectively overcome inhibition compared to a PRM coating. We also assessed changes in gene expression of reactive astrocytes with soluble PRM and determined that PRM does not increase their neurotoxic phenotype and that PRM may reduce brevican production and serpin transcription in cortical and spinal cord astrocytes. This is the first study to thoroughly assess the toxicity threshold of PRM with neural cells and study astrocyte response after acute exposure to PRM in vitro.

Downregulation of Sepina3n Aggravated Blood-Brain Barrier Disruption after Traumatic Brain Injury by Activating Neutrophil Elastase in Mice

Traumatic brain injury (TBI) is the leading cause of death in young adults and the main cause of mortality and disability across all ages worldwide. We previously analyzed the expression profile data of TBI models obtained from the Gene Expression Omnibus (GEO) database and found that the seripina3n mRNA was markedly upregulated in the acute phase of TBI in four mRNA expression profile data sets, indicating that serpina3n may be involved in the pathophysiological process of TBI. Therefore, we further investigated the biological role and molecular mechanism of serpina3n in traumatic brain injury in this study. As a result, the endogenous level of sepina3n was markedly elevated in the cortex around the contusion sit in mice at day 1 and day 3 after TBI. Inhibiting the expression of serpina3n caused aggravation of neutrophil elastase (NE) expression, BBB disruption, and neurological deficit. With the inactivation of NE, even if serpina3n was silenced, the disruption of the BBB was not further aggravated. In vitro experiments further proved that recombinant serpina3n dose-dependently inhibited the activity of recombinant NE. Based on the above, this study demonstrated that the endogenous level of sepina3n was significantly elevated in the cortex around the contusion sit after TBI in mice, which reduced the secondary blood-brain barrier disruption by inhibiting the activity of neutrophil elastase.

Mechanism of hydroxysafflor yellow A on acute liver injury based on transcriptomics

Objective: To investigate how Hydroxysafflor yellow A (HSYA) effects acute liver injury (ALI) and what transcriptional regulatory mechanisms it may employ.

Methods: Rats were randomly divided into five groups (n = 10): Control, Model, HSYA-L, HSYA-M, and HSYA-H. In the control and model groups, rats were intraperitoneally injected with equivalent normal saline, while in the HSYA groups, they were also injected with different amounts of HSYA (10, 20, and 40 mg/kg/day) once daily for eight consecutive days. One hour following the last injection, the control group was injected into the abdominal cavity with 0.1 ml/100 g of peanut oil, and the other four groups got the same amount of a peanut oil solution containing 50% CCl4. Liver indexes were detected in rats after dissection, and hematoxylin and eosin (HE) dyeing was utilized to determine HSYA’s impact on the liver of model rats. In addition, with RNA-Sequencing (RNA-Seq) technology and quantitative real-time PCR (qRT-PCR), differentially expressed genes (DEGs) were discovered and validated. Furthermore, we detected the contents of anti-superoxide anion (anti-O2−) and hydrogen peroxide (H2O2), and verified three inflammatory genes (Icam1, Bcl2a1, and Ptgs2) in the NF-kB pathway by qRT-PCR.

Results: Relative to the control and HSYA groups, in the model group, we found 1111 DEGs that were up-/down-regulated, six of these genes were verified by qRT-PCR, including Tymp, Fabp7, Serpina3c, Gpnmb, Il1r1, and Creld2, indicated that these genes were obviously involved in the regulation of HSYA in ALI model. Membrane rafts, membrane microdomains, inflammatory response, regulation of cytokine production, monooxygenase activity, and iron ion binding were significantly enriched in GO analysis. KEGG analysis revealed that DEGs were primarily enriched for PPAR, retinol metabolism, NF-kB signaling pathways, etc. Last but not least, compared with the control group, the anti-O2− content was substantially decreased, the H2O2 content and inflammatory genes (Icam1, Bcl2a1, and Ptgs2) levels were considerably elevated in the model group. Compared with the model group, the anti-O2− content was substantially increased, the H2O2 content and inflammatory genes (Icam1, Bcl2a1, and Ptgs2) levels were substantially decreased in the HSYA group (p &lt; 0.05).

Conclusion: HSYA could improve liver function, inhibit oxidative stress and inflammation, and improve the degree of liver tissue damage. The RNA-Seq results further verified that HSYA has the typical characteristics of numerous targets and multiple pathway. Protecting the liver from damage by regulating the expression of Tymp, Fabp7, Serpina3c, Gpnmb, Il1r1, Creld2, and the PPAR, retinol metabolism, NF-kappa B signaling pathways.

Transient response of serpinA3 during cellular stress

We demonstrated that serpinA3c/k relocates from the cytoplasm to the apical tubular membrane (ATM) in chronic kidney disease (CKD), suggesting its secretion in luminal space in pathophysiological contexts. Here, we studied serpinA3c/k expression and secretion under different stressful conditions in vitro and in vivo. HEK-293 cells were transfected with a FLAG-tagged serpinA3c/k clone and exposed to H₂ O₂ or starvation. Both stressors induced serpinA3c/k secretion but with a higher molecular weight. Glycanase treatment established that serpinA3c/k is glycosylated. Site-directed mutagenesis for each of the four glycosylation sites was performed. During cellular stress, serpinA3c/k secretion increased with each mutant except in the quadruple mutant. In rats and patients suffering acute kidney injury (AKI), an atypical urinary serpinA3c/k excretion (uSerpinA3c/k) was observed. In rats with AKI, the greater the induced kidney damage, the greater the uSerpinA3 c/k, together with relocation toward ATM. Our findings show that: (1) serpinA3c/k is glycosylated and secreted, (2) serpinA3c/k secretion increases during cellular stress, (3) its appearance in urine reveals a pathophysiological state, and (4) urinary serpinA3 excretion could become a potential biomarker for AKI.

Mechanical Stretching-Induced Traumatic Brain Injury Is Mediated by the Formation of GSK-3β-Tau Complex to Impair Insulin Signaling Transduction

Traumatic brain injury confers a significant and growing public health burden. It is a major environmental risk factor for dementia. Nonetheless, the mechanism by which primary mechanical injury leads to neurodegeneration and an increased risk of dementia-related diseases is unclear. Thus, we aimed to investigate the effect of stretching on SH-SY5Y neuroblastoma cells that proliferate in vitro. These cells retain the dopamine-β-hydroxylase activity, thus being suitable for neuromechanistic studies. SH-SY5Y cells were cultured on stretchable membranes. The culture conditions contained two groups, namely non-stretched (control) and stretched. They were subjected to cyclic stretching (6 and 24 h) and 25% elongation at 1 Hz. Following stretching at 25% and 1 Hz for 6 h, the mechanical injury changed the mitochondrial membrane potential and triggered oxidative DNA damage at 24 h. Stretching decreased the level of brain-derived neurotrophic factors and increased amyloid-β, thus indicating neuronal stress. Moreover, the mechanical injury downregulated the insulin pathway and upregulated glycogen synthase kinase 3β (GSK-3β)^S9/p-Tau protein levels, which caused a neuronal injury. Following 6 and 24 h of stretching, GSK-3β^S9 was directly bound to p-Tau^S396. In contrast, the neuronal injury was improved using GSK-3β inhibitor TWS119, which downregulated amyloid-β/p-Taus396 phosphorylation by enhancing ERK1/2T202/Y204 and AktS473 phosphorylation. Our findings imply that the neurons were under stress and that the inactivation of the GSK3β could alleviate this defect.

Tandem Mass Tag-Based Quantitative Proteomic Analysis Reveals Pathways Involved in Brain Injury Induced by Chest Exposure to Shock Waves

Recurrent chest blast exposure can lead to brain inflammation, oxidative stress, and mental disorders in soldiers. However, the mechanism that underlies brain injury caused indirectly by chest blasts remains unclear. It is urgent to find additional reliable biomarkers to reveal the intimate details of the pathogenesis of this phenomenon. We used the term tandem mass tag (TMT) labeling combined with liquid chromatography–tandem mass spectrometry (LC-MS/MS) to screen for differentially expressed proteins in rat brain at different time points after a chest blast. Data are available via ProteomeXchange with the identifier PXD025204. Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), the Database for Annotation, Visualization and Integrated Discovery (DAVID), and Cytoscape analyses were used to analyze the proteomic profiles of blast-exposed rats. In addition, we performed Western blotting to verify protein levels. We identified 6,931 proteins, of which 255 were differentially expressed and 43, 84, 52, 97, and 49 were identified in brain tissues at 12, 24, 48, and 72 h and 1 week after chest blast exposure, respectively. In this study, the GO, KEGG, Clusters of Orthologous Groups of proteins, and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analyses indicated that brain damage caused by chest blast exposure involved many important biological processes and signaling pathways, such as inflammation, cell adhesion, phagocytosis, neuronal and synaptic damage, oxidative stress, and apoptosis. Furthermore, Western blotting confirmed that these differentially expressed proteins and affected signaling pathways were associated with brain damage caused by chest blast exposure. This study identifies potential protein biomarkers of brain damage caused indirectly by chest blast and new targets for the treatment of this condition.

Multi-omics analysis of brain tissue metabolome and proteome reveals the protective effect of gross saponins of Tribulus terrestris L. fruit against ischemic stroke in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Gross Saponins of Tribulus terrestris L. Fruit (GSTTF) has been reported to have a protective effect against ischemic stroke, but the related mechanism is complex and still not fully investigated.

AIM OF THE STUDY

The combination of metabolomics and proteomics approach was applied to reveal the mechanisms of GSTTF in treating ischemic stroke.

MATERIALS AND METHODS

The metabolite and protein changes in brain tissue were analyzed by the LC-MS-based untargeted metabolomics method and tandem mass tags (TMT)-based quantitative proteomics technology. The multivariate statistical analysis and protein-protein interaction (PPI) analysis were conducted to screen out the biomarkers, and their related pathway was further investigated by the joint pathway analysis.

RESULTS

A total of 110 metabolites and 359 differential proteins, which were mainly associated with complement and coagulation cascades, sphingolipid metabolism, glycerophospholipid metabolism, glutathione metabolism, and platelet activation, etc. were screened out from the rat brain tissue. The PPI network exhibited that the protein F2, Fga, Fgb, Fgg, Plg, and C3, which are greatly involved in the complement and coagulation cascades, have a relatively high connectivity degree, indicating their importance in the process of middle cerebral artery occlusion (MCAO). The GSTTF exerted a protective effect against MCAO via modulating multiple proteins on this pathway. Moreover, F2 played a key role during the protective process and worth to be further investigated due to it has been reported as one of the therapeutic targets of ischemic stroke.

CONCLUSION

The present study could improve the understanding of the potential therapeutic mechanism of GSTTF against ischemic stroke.

In Vitro Models of Traumatic Brain Injury: A Systematic Review

Traumatic brain injury (TBI) is a major public health challenge that is also the third leading cause of death worldwide. It is also the leading cause of long-term disability in children and young adults worldwide. Despite a large body of research using predominantly in vivo and in vitro rodent models of brain injury, there is no medication that can reduce brain damage or promote brain repair mainly due to our lack of understanding in the mechanisms and pathophysiology of the TBI. The aim of this review is to examine in vitro TBI studies conducted from 2008-2018 to better understand the TBI in vitro model available in the literature. Specifically, our focus was to perform a detailed analysis of the in vitro experimental protocols used and their subsequent biological findings. Our review showed that the uniaxial stretch is the most frequently used way of load application, accounting for more than two-thirds of the studies reviewed. The rate and magnitude of the loading were varied significantly from study to study but can generally be categorized into mild, moderate, and severe injuries. The in vitro studies reviewed here examined key processes in TBI pathophysiology such as membrane disruptions leading to ionic dysregulation, inflammation, and the subsequent damages to the microtubules and axons, as well as cell death. Overall, the studies examined in this review contributed to the betterment of our understanding of TBI as a disease process. Yet, our review also revealed the areas where more work needs to be done such as: 1) diversification of load application methods that will include complex loading that mimics in vivo head impacts; 2) more widespread use of human brain cells, especially patient-matched human cells in the experimental set-up; and 3) need for building a more high-throughput system to be able to discover effective therapeutic targets for TBI.

A novel bone-thinning technique for transcranial stimulation motor-evoked potentials in rats

Transcranial electrical stimulated motor-evoked potentials (tcMEPs) are widely used to evaluate motor function in humans, and even in animal studies, tcMEPs are used to evaluate neurological dysfunction. However, there is a dearth of reports on extended tcMEP recordings in both animal models and humans. Therefore, this study examined a new technique for stably recording tcMEPs over several weeks in six healthy female Sprague–Dawley rats. We thinned the skull bone using the skull base and spinal surgery technique to reduce electrical resistance for electrical stimulation. tcMEPs were recorded on days 1, 7, 14, 21, and 28 after surgery. The onset latency and amplitude of tcMEPs from the hindlimbs were recorded and evaluated, and histological analysis was performed. Stable amplitude and onset latency could be recorded over several weeks, and histological analysis indicated no complications attributable to the procedure. Thus, our novel technique allows for less invasive, safer, easier, and more stable extended tcMEP recordings than previously reported techniques. The presently reported technique may be applied to the study of various nerve injury models in rats: specifically, to evaluate the degree of nerve dysfunction and recovery in spinal cord injury, cerebral infarction, and brain contusion models.

Changes in redox plasma proteome of Pon1-/- mice are exacerbated by a hyperhomocysteinemic diet

High-density lipoprotein (HDL), in addition to promoting reverse cholesterol transport, possesses anti-oxidative, anti-inflammatory, and antithrombotic activities, which are thought to be promoted by paraoxonase 1 (PON1), an HDL-associated enzyme. Reduced levels of PON1 are associated with increased oxidative stress and cardiovascular disease both in humans and Pon1^-/- mice. However, molecular basis of these associations are not fully understood. We used label-free mass spectrometry and Ingenuity Pathway Analysis bioinformatics resources to examine plasma proteomes in four-month-old Pon1^-/- mice (n = 32) and their Pon1^+/+ siblings (n = 15) fed with a hyper-homocysteinemic (HHcy) diet. We found that inactivation of the Pon1 gene resulted in dysregulation of proteins involved in the maintenance of redox homeostasis in mice. Redox-responsive proteins affected by Pon1^-/- genotype were more numerous in mice fed with HHcy diet (18 out of 89, 20%) than in mice fed with a control diet (4 out of 50, 8%). Most of the redox-related proteins affected by Pon1^-/- genotype in mice fed with a control diet (3 out of 4, 75%) were also affected in HHcy mice, while the majority of Pon1^-/- genotype-dependent redox proteins in HHcy mice (15 out of 18, 83%) were not affected by Pon1^-/- genotype in control diet animals. In addition to redox-related proteins, we identified proteins involved in acute phase response, complement/blood coagulation, lipoprotein/lipid metabolism, immune response, purine metabolism, glucose metabolism, and other proteins that were dysregulated by Pon1^-/- genotype in HHcy mice. Taken together, our findings suggest that Pon1 interacts with proteins involved in antioxidant defenses and other processes linked to cardiovascular disease. Dysregulation of these processes provides an explanation for the pro-oxidant and pro-atherogenic phenotypes observed in Pon1^-/- mice and humans with attenuated PON1 levels.

Ischemic Stroke Increased Gadolinium Deposition in the Brain and Aggravated Astrocyte Injury After Gadolinium-Based Contrast Agent Administration: Linear Versus Macrocyclic Agents

BACKGROUND

Gadolinium (Gd)-based contrast agents (GBCAs) have been widely used in MRI. However, several studies have reported Gd deposition in the brain, which has raised concerns about safety.

PURPOSE

To investigate the effects of ischemic stroke on Gd deposition in the brain after repeated administration of linear or macrocyclic GBCAs and to determine whether GBCAs aggravate astrocyte injury after stroke.

STUDY TYPE

Animal study.

ANIMAL MODEL

Twenty-seven male Sprague-Dawley rats were randomized to an exposure group (n = 24) and a healthy control group (n = 3). Half of the exposure group (n = 12) underwent transient middle cerebral artery occlusion (tMCAO) and half (n = 12) had a sham procedure. In each subgroup (tMCAO or sham), the rats had repeated gadopentetate (n = 6) or gadobutrol (n = 6) injections. Oxygen-glucose deprivation and reoxygenation (OGD/R) was used as an in vitro model of stroke.

ASSESSMENT

On day 3 and day 28 after the last injection (p.i.), the Gd concentration in the cerebrum was quantified by inductively coupled plasma mass spectrometry. Cell viability, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were analyzed in vitro.

STATISTICAL TESTS

One-way analysis of variance and two-sample t-tests were performed.

RESULTS

The Gd concentration in the ipsilateral hemisphere homogenates of tMCAO group was significantly higher than that in the brain homogenates of the sham group on day 3 p.i. of either gadobutrol (0.065 ± 0.006 vs. 0.042 ± 0.007 μg/g, P < 0.05) or gadopentetate (0.093 ± 0.010 vs. 0.069 ± 0.008 μg/g, P < 0.05). Increased Gd deposition was also found in the ipsilateral hemisphere homogenates of the tMCAO group compared with the brain homogenates of the sham group on day 28 p.i. of gadopentetate (0.075 ± 0.012 vs. 0.044 ± 0.003 μg/g, P < 0.05), but not gadobutrol (0.012 ± 0.007 vs. 0.010 ± 0.001 μg/g, P = 0.80). The Gd concentration in the ipsilateral hemisphere in the tMCAO group was significantly higher for gadopentetate than gadobutrol on both day 3 p.i. (0.085 ± 0.006 vs. 0.049 ± 0.005 μg/g, P < 0.05) and day 28 p.i (0.075 ± 0.012 vs. 0.012 ± 0.007 μg/g, P < 0.05). Additionally, compared with gadobutrol, gadopentetate decreased viability, increased ROS accumulation, and decreased MMP in OGD/R-induced astrocytes (all P < 0.05).

DATA CONCLUSION

Administration of GBCAs after an animal model of ischemic stroke increased Gd deposition in the brain and aggravated astrocyte injury. The effect of gadopentetate appeared to be more pronounced than that of gadobutrol.

Tanshinone IIA Promotes M2 Microglia by ERβ/IL-10 Pathway and Attenuates Neuronal Loss in Mouse TBI Model

PURPOSE

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Increasing evidence indicates that activated microglia play an important role in the inflammatory response in TBI. Inhibiting M1 and stimulating M2 activated microglia have protective effects in several animal models of central nervous system (CNS) disorders. In the present study, we investigated whether tanshinone IIA (TNA) protects neurons by shifting microglia polarization in a mouse TBI model and further investigated the mechanism in vitro.

MATERIALS AND METHODS

Forty C57BL/6 mice were used to investigate the effect of TNA on microglia polarization in TBI. BV-2 cells were used to examine the mechanism of TNA in regulating microglia polarization.

RESULTS

Normal saline (NS), TNA and the combination of TNA with ICI 182,780 (ICI, an estrogen receptor antagonist) were used to treat the TBI mice. After TBI, mice from each group demonstrated functional improvement. The improvement rate in mice treated with TNA was faster than other groups. ICI partially reversed the benefits from TNA treatment. TNA treatment significantly reduced TBI-induced neuronal loss. The number of microglia after TBI was not significantly changed by TNA treatment. However, TNA treatment significantly decreased M1 macrophage markers (iNOS, TNFα and IL-1β) and increased M2 macrophage markers (CD206, arginase 1 and Ym1). This effect was partially abolished by ICI. TNA treatment downregulated M1 macrophage markers and upregulated M2 macrophage markers in BV-2 cells under LPS stimulation. IL-10 was significantly increased by TNA treatment without a significantly change of IL-4 and IL-13 expression. IL-10 knockdown completely abolished the effect of TNA on microglial M2 polarization.

CONCLUSION

Taken together, our data demonstrated that TNA attenuates neuronal loss in mouse TBI model and promotes M2 microglia by ERβ/IL-10 pathway. Thus, TNA could be a potential drug for TBI and/or the disorders that caused by microglial over-activation in CNS.