Social and paternal female choice for male MHC genes in golden snub-nosed monkeys (Rhinopithecus roxellana).

Genes of the major histocompatibility complex (MHC) play important roles in vertebrate immunocompetence. MHC genes thus offer females indirect benefits to mate choice through the production of offspring of an optimal MHC genotype. Females may choose males with specific MHC haplotypes, dissimilar MHC genotypes, MHC heterozygous males or MHC-diverse males. We tested these four alternatives for both female social and paternal choice in wild golden snub-nosed monkeys (Rhinopithecus roxellana) by examining overall genetic variability (via microsatellites) and four MHC-genes (DRB1, DRB2, DQA1 and DQB1). Monte Carlo randomization tests showed that MHC dissimilarity was favoured for social choice (males to which females were socially affiliated) and intermediate MHC dissimilarity was favoured in paternal choice (fathers of offspring). No evidence of inbreeding avoidance was found for either social or paternal mates. We found that MHC heterozygotes, higher microsatellite multilocus heterozygosity and higher microsatellites diversity were favoured for social mates, and higher microsatellite diversity was favoured for paternal mates. Independent of male age, we found that the formation of male-female social pairings is significantly predicted by compatibility based on the sharing of MHC haplotypes. However, we found no evidence of independent genetic effects on the duration of male-female social pairings, male social status (achieving OMU leader male status or not), the number of females with which individual leader males paired, the likelihood of potential male-female pairings producing offspring, or whether males fathered offspring or not. Overall, our findings suggest different genetic factors are involved in social and paternal choice in R. roxellana.

Effect of the Deletion of icl1 Gene and icl2 Gene on the Growth Rate of Mycobacterium tuberculosis and the Specific Regulatory Mechanism Involved.

Objective: To explore the effect of the deletion of the icl1 gene and icl2 gene on the growth rate of Mycobacterium tuberculosis (Mtb) and the specific regulatory mechanism involved. Methods: H37Rv was purchased from the Tuberculosis Prevention and Control Institute, and H37Rv was grown in Middlebrook 7H9 broth. Macrophages THP-1 cells were purchased by our researchers from the Cell Bank of the Chinese Academy of Sciences, which were maintained in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% fetal bovine serum (FBS), at 37°C and 5% CO2. The experiment was divided into 3 groups: the control group (H37Rv infected with THP-1 cells), the icl1/2 deletion group (H37Rv infected with icl1/2 deleted THP-1 cells) and the icl1/2 complementation group (H37Rv infected with icl1/2 deletion, icl1/2 complementary THP-1 cells). Absorbance was measured with a microplate spectrophotometer and the bacterial growth rate was calculated. The colony-forming units (CFU) obtained from the dilution was used to calculate the total number of CFU per milliliter and the percentage of survival of mycobacteria. The protein levels of isocitrate lyase 1 (ICL1), ICL2, p-mTOR and p-Akt were analyzed by Western blot. The CD4+ level was analyzed by flow cytometry. The mRNA expression levels of CCL20, CXCL2, CXCL8, interferon gamma (IFN-γ), interleukin (IL)-17 and IL-22 were analyzed using the quantitative reverse transcription polymerase chain reaction (RT-qPCR) method. Stably transformed monomeric red fluorescent protein (mRFP)-green fluorescent protein (GFP)-LC3 reporter THP-1 cells were used to monitor the aggregation of LC3B in autophagosomes and autophagolysosomes. Results: The Mtb growth rate and CFU of the icl1/2 deletion group were decreased in comparison with the control group (P < .05). When compared with the icl1/2 deletion group, however, the Mtb growth rate and CFU of the icl1/2 complementation group were associated with increased results (P < .05). The protein levels of ICL1 and ICL2 in the icl1/2 deletion group were significantly decreased compared with the control group (P < .05), which were evidently increased in the icl1/2 complementation group when compared with the icl1/2 deletion group (P < .05). In addition, compared with the control group (25.16 ± 2.18), the level of CD4+ appeared to be increased in the icl1/2 deletion group (62.37 ± 5.46) (P < .05), while it was decreased in the icl1/2 complementation group compared with the icl1/2 deletion group (28.33 ± 1.32) (P < .05). The expression levels of chemokine (C-C motif) ligand 20 (CCL20), chemokine (C-X-C motif) ligand 2 (CXCL2), chemokine (C-X-C motif) ligand 8 (CXCL8), IL-17, IFN-γ, and IL-22 mRNA were increased in the icl1/2 deletion group compared with the control group (P < .05), which were significantly decreased in the icl1/2 complementary group compared with the icl1/2 deletion group (P < .05). A comparison between the control group and the icl1/2 deletion group showed that the latter increased the formation of autophagosomes and autophagolysosomes in H37Rv-infected cells (P < .05). However, compared with the icl1/2 deletion group, the icl1/2 complementation group decreased the formation of autophagosomes and autolysosomes in H37Rv-infected cells (P < .05). Moreover, the expression levels of phosphor-mammalian target of rapamycin (p-mTOR) and p-Akt in the icl1/2 deletion group were significantly reduced compared with the control group (P < .05), and were increased in the icl1/2 complementation group compared with the icl1/2 deletion group (P < .05). Conclusion: Loss of icl1/2 was believed to increase the expression of CD4 and CCL20, CXCL8 as well as CXCL2 in the immune system, which increased autophagy. Furthermore, it exerted potential in inhibiting the growth of intracellular Mtb in macrophages.

Glucose metabolism: A link between traumatic brain injury and Alzheimer's disease.

Traumatic brain injury (TBI), a growing public health problem, is a leading cause of death and disability worldwide, although its prevention measures and clinical cares are substantially improved. Increasing evidence shows that TBI may increase the risk of mood disorders and neurodegenerative diseases, including Alzheimer's disease (AD). However, the complex relationship between TBI and AD remains elusive. Metabolic dysfunction has been the common pathology in both TBI and AD. On the one hand, TBI perturbs the glucose metabolism of the brain, and causes energy crisis and subsequent hyperglycolysis. On the other hand, glucose deprivation promotes amyloidogenesis via ß-site APP cleaving enzyme-1 dependent mechanism, and triggers tau pathology and synaptic function. Recent findings suggest that TBI might facilitate Alzheimer's pathogenesis by altering metabolism, which provides clues to metabolic link between TBI and AD. In this review, we will explore how TBI-induced metabolic changes contribute to the development of AD.

Corticosteroid receptor rebalancing alleviates critical illness-related corticosteroid insufficiency after traumatic brain injury by promoting paraventricular nuclear cell survival via Akt/CREB/BDNF signaling.

BACKGROUND: We previously found that high-dose methylprednisolone increased the incidence of critical illness-related corticosteroid insufficiency (CIRCI) and mortality in rats with traumatic brain injury (TBI), whereas low-dose hydrocortisone but not methylprednisolone exerted protective effects. However, the receptor-mediated mechanism remains unclear. This study investigated the receptor-mediated mechanism of the opposite effects of different glucocorticoids on the survival of paraventricular nucleus (PVN) cells and the incidence of CIRCI after TBI. METHODS: Based on controlled cortical impact (CCI) and treatments, male SD rats (n = 300) were randomly divided into the sham, CCI, CCI + GCs (methylprednisolone 1 or 30 mg/kg/day; corticosterone 1 mg/kg/day), CCI + methylprednisolone+RU486 (RU486 50 mg/kg/day), and CCI + corticosterone+spironolactone (spironolactone 50 mg/kg/day) groups. Blood samples were collected 7 days before and after CCI. Brain tissues were collected on postinjury day 7 and processed for histology and western blot analysis. RESULTS: We examined the incidence of CIRCI, mortality, apoptosis in the PVN, the receptor-mediated mechanism, and downstream signaling pathways on postinjury day 7. We found that methylprednisolone and corticosterone exerted opposite effects on the survival of PVN cells and the incidence of CIRCI by activating different receptors. High-dose methylprednisolone increased the nuclear glucocorticoid receptor (GR) level and subsequently increased cell loss in the PVN and the incidence of CIRCI. In contrast, low-dose corticosterone but not methylprednisolone played a protective role by upregulating mineralocorticoid receptor (MR) activation. The possible downstream receptor signaling mechanism involved the differential effects of GR and MR on the activity of the Akt/CREB/BDNF pathway. CONCLUSION: The excessive activation of GR by high-dose methylprednisolone exacerbated apoptosis in the PVN and increased CIRCI. In contrast, refilling of MR by corticosterone protects PVN neurons and reduces the incidence of CIRCI by promoting GR/MR rebalancing after TBI.

Rational Design and Synthesis of Carboxylate Gemini Surfactants with an Excellent Aggregate Behavior for Nano-La2O3 Morphology-Controllable Preparation.

A series of carboxylate gemini surfactants (CGS, Cn-Φ-Cn, n = 12, 14, 16, 18) with diphenyl ketone as a spacer group were prepared using a simple and feasible synthetic method. These CGS exhibited an excellent surface activity with extremely low critical micelle concentration (CMC) value (approximately 10-5 mol/L), good performance in reducing surface tension (nearly 30 mN/m), and the ability of molecular self-assembly into different aggregate morphologies via adjusting the concentrations, which is attributed to the introduction of diphenyl ketone and carboxylic acid ammonium salt in the molecular structure. Moreover, the surface activity and self-assembly ability of CGS were further optimized by tuning the length of the tail chain. These excellent properties imply that CGS can be a soft template to prepare nanomaterials, especially in morphology-controllable synthesis. By adjusting the concentration of one of CGS (C12-Φ-C12), nano-La2O3 particles with diverse morphologies were obtained, including spherical shape, bead-chain shape, rod shape, velvet-antler shape, cedar shape, and bowknot shape. This work offers a vital insight into the rational design of template agents for the development of morphology-controllable nanomaterials.

Supraclavicular lymph node incisional biopsies have no influence on the prognosis of advanced non-small cell lung cancer patients: a retrospective study.

BACKGROUND: Supraclavicular lymph node (SCLN) biopsies play an important role in diagnosing and staging lung cancer. However, not all patients with SCLN metastasis can have a complete resection. It is still unknown whether SCLN incisional biopsies affect the prognosis of non-small cell lung cancer (NSCLC) patients. METHODS: Patients who were histologically confirmed to have NSCLC with SCLN metastasis were enrolled in the study from January 2007 to December 2012 at Guangdong Lung Cancer Institute. The primary endpoint was OS, and the secondary endpoints were complications and local recurrence/progression. RESULTS: Two hundred two consecutive patients who had histologically confirmed NSCLC with SCLN metastasis were identified, 163 with excisional and 39 with incisional biopsies. The median OS was not significantly different between the excisional (10.9 months, 95% CI 8.7-13.2) and incisional biopsy groups (10.1 months, 95% CI 6.3-13.9), P = 0.569. Multivariable analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2 (HR = 2.75, 95% CI 1.71-4.38, P < 0.001) indicated a worse prognosis. Having an epidermal growth factor receptor (EGFR) mutation (HR = 0.58, 95% CI 0.40-0.84, P = 0.004) and receiving systemic treatment (HR = 0.36, 95% CI 0.25-0.53, P < 0.001) were associated with a favorable OS. Neither the number (multiple vs. single) nor site (bilateral vs. unilateral) of SCLNs was associated with an unfavorable OS, and SCLN size or fixed SCLNs did not affect OS. CONCLUSIONS: SCLN incisional biopsies did not negatively influence the prognosis of NSCLC patients. It was safe and feasible to partly remove a metastatic SCLN as a last resort in advanced NSCLC.

IMM-H004, A New Coumarin Derivative, Improved Focal Cerebral Ischemia via Blood-Brain Barrier Protection in Rats.

OBJECTIVE: IMM-H004 (7-hydroxy-5-methoxy-4-methyl-3-[4-methylpiperazin-1-yl]-2H-chromen-2-one) is a novel coumarin derivative that showed better effect in improving global cerebral ischemia in rats. However, the effects and mechanisms in focal cerebral ischemia were not clear. Blood-brain barrier (BBB) protection is a vital strategy for the treatment of cerebral ischemia. This study is to investigate whether IMM-H004 improves brain ischemia injury via BBB protection. METHODS: Focal brain ischemia model was induced by middle cerebral artery occlusion for 1 hour and reperfusion (MCAO/R) for 24 hours in rats. IMM-H004 (1.5, 3, 6 mg/kg) and edaravone (positive drug, 6 mg/kg) were administered after 5 minutes of occlusion. Neurological score and TTC staining were used to evaluate the effect of IMM-H004. Evans Blue (EB) staining and electron microscopy were used to assess BBB permeability. Western blot, reverse transcription-polymerase chain reaction, and immunohistochemistry were used to detect the expression of BBB structure-related proteins. RESULTS: Compared with the model group, IMM-H004 in the focal brain ischemia model improved neurological function and reduced cerebral infarction size and edema content. IMM-H004 sharply reduced the EB content and alleviated BBB structure. In addition, IMM-H004 increased the level of zonula occludens (ZO-1) and occluding, decreased the level of aquaporin 4 and matrix metalloproteinase 9, either in cortex or in hippocampus. And all of these changed were related to BBB protection. CONCLUSION: IMM-H004 improved cerebral ischemia injury via BBB protection. For a potential therapy drug of cerebral ischemia, IMM-H004 merits further study.

Distribution and prognosis of uncommon metastases from non-small cell lung cancer.

BACKGROUND: According to the literature and our experience, the most common sites of non-small cell lung cancer (NSCLC) metastases include the brain, bone, liver, adrenal glands, contralateral lung and distant lymph nodes. Metastases to other organs are relatively rare. There have been numerous case reports and a few small case series of uncommon metastases derived from NSCLC. METHODS: We defined all organs except the common metastatic sites mentioned above as uncommon sites of metastasis. Patients with uncommon metastases among 2,872 consecutive NSCLC patients with stage IV disease at the Guangdong Lung Cancer Institute (GLCI) from 2006 to 2012 were included in this study. The diagnosis of uncommon metastases was based on pathology or imaging studies. RESULTS: Uncommon metastases were diagnosed in 193 cases at anatomical sites such as the soft tissue, kidney, pancreas, spleen, peritoneum, intestine, bone marrow, eye, ovary, thyroid, heart, breast, tonsil and nasal cavity. Uncommon metastases were identified as independent poor prognostic factors through a multivariate analysis with a HR (hazard ratio) of 1.29 [95% confidence interval (CI) 1.09-1.52, P < 0.01]. Those patients who received systemic therapy plus local treatment had a better survival rate than did those who received systemic therapy only (P < 0.01); all patients received best supportive care. CONCLUSIONS: Metastases to the above mentioned sites are infrequent. The presentation of uncommon metastases tends to indicate a poor outcome, and selected patients may benefit from local treatment.

LB-1 Exerts Antitumor Activity in Pancreatic Cancer by Inhibiting HIF-1α and Stat3 Signaling.

Hypoxia is widely present in pancreatic cancer and subsequently causes the overexpression of hypoxia-inducible factor-1α (HIF-1α) and signal transducer and activator of transcription-3 (Stat3). HIF-1α and Stat3 function cooperatively to regulate a number of downstream genes that are implicated in tumorigenesis. Thus, inhibition of HIF-1α and Stat3 is a potential therapeutic strategy for pancreatic cancer. In this study, we explored how LB-1, a novel triptolide (LA) derivative, exerted its antitumor effect through blockade of HIF-1α and Stat3 signaling. Our data showed that LB-1 was able to inhibit the proliferation and colony formation of Mia-PaCa2 and SW1990 cells. LB-1 suppressed HIF-1α protein accumulation by promoting its proteasome degradation and reducing transactivation. Moreover, the silence of HIF-1α by shRNA partially prevented the proliferation inhibition triggered by LB-1. As expected, LB-1 also decreased Stat3 protein accumulation and blocked the physical interactions between HIF-1α/p300/phosphor-Stat3 (p-Stat3) at the pharmacological concentration to reduce VEGF expression, thereby hypoxia-induced angiogenesis. In the Mia-PaCa2 nude xenograft model, therapeutic treatment with LB-1 significantly inhibited tumor growth and had minimal systemic toxicity compared to the mother drug LA. Furthermore, in accordance with in vitro results, HIF-1α activation and Stat3 expression in tumors were blocked by LB-1 through mTOR-dependent pathway. Taken together, these results illustrate that, as a potent inhibitor of HIF-1α and Stat3 signaling, LB-1 exhibits antitumor effect and could be potentially used to treat pancreatic cancer.

Differences in driver genes between smoking-related and non-smoking-related lung cancer in the Chinese population.

Recently, non-smoking-related lung cancer was classified as an independent disease entity because it is different from tobacco-associated lung cancer. Non-smoking-related lung cancer occurs more often in women than men, and the predominant histological type is adenocarcinoma (ADC) rather than squamous cell carcinoma. Most of the driver gene alterations that have been identified in ADC in never-smokers include epidermal growth factor receptor mutations, KRAS mutations, echinoderm microtubule-associated protein like 4/anaplastic lymphoma kinase fusion, and ROS1 fusion, among others. Meanwhile, significant progress has been made in the treatment of ADC. However, in comparison with ADC, no such available molecular targets exist for smoking-associated lung cancer, for which treatment strategies are limited. Next-generation sequencing has been widely applied to the discovery of more genetic profiles of lung cancers. This review summarizes the differences between smoking-related and non-smoking-related lung cancer as follows: different somatic mutation burdens, C:G→A:T transversions, common and novel driver genes, and treatment strategies. Overall, smoking-related lung cancer is more complicated than non-smoking-related lung cancer. Furthermore, we review the prevalence of driver genes in smoking-associated and non-smoking-associated lung cancers in the Chinese population.

Multiple primary malignancies involving lung cancer.

BACKGROUND: The incidence of multiple primary malignancies (MPM) has increased sharply in recent decades. However, the clinical characteristics and prognosis of MPM patients involving lung cancer were not fully elucidated. This retrospective study was designed to explore the clinical characteristics and prognosis of MPM patients involving lung cancer in the People's Republic of China. METHODS: Of 5405 lung cancer cases diagnosed at the Guangdong Lung Cancer Institute between 2005 and 2013, we analyzed 185 patients (3.4 %) with MPM involving lung cancer. RESULTS: Among 185 patients with MPM involving lung cancer, 10 (5.4 %)had three malignancies and 175 (94.6 %) had two malignancies. 10 patients with three malignancies were excluded from the analysis to avoid misunderstanding. Of 175 accompanying malignancies, 64 (36.6 %) were synchronous MPM patients and 111 (63.4 %) were metachronous MPM patients; 49 (28.0 %) were lung cancer first MPM patients and 126 (72.0 %) were other cancer first MPM patients. The most frequent accompanying malignancy was colon cancer (25/175), followed by rectal cancer (18/175), esophageal cancer (17/175), and thyroid cancer (13/175). Metachronous MPM patients showed significantly better overall survival (OS) than synchronous MPM, with a median OS of 72.8 (range 12.2-391.0) and 12.9 (range 0.8-86.3)months, respectively (P < 0.001). Cox regression analysis revealed that time of occurrence and stage were independent factors for OS. CONCLUSIONS: Colorectal cancer, esophageal cancer, and thyroid cancer were the tumors that most frequently accompanying lung cancer. Metachronous MPM patients showed significantly better OS compared with synchronous MPM patients.

[Research progress of hypoxia-inducible factor 1 inhibitors against tumors].

Hypoxia occurs in chronic and acute vascular diseases and tumor formation. The ability of tumor cells to maintain a balance between an adaptation to hypoxia and cell death is regulated by a family of transcription factors called hypoxia-inducible factor 1 (HIF-1). Tumor hypoxia mediated by HIF-1 would facilitate the likelihood of resistance to chemotherapy and radiotherapy, proliferation, metastasis and the invasive potential; all of which culminate in a decrease in patient survival. And HIF-1 alpha subunit decides the activity of HIF-1, which is regulated by oxygen. So understanding the role of HIF in signal pathway, drug resistance mechanism and its feature is crucial for developing novel anticancer therapies. In recent years, more attentions have focused on HIF-1 alpha inhibitors. It is expected that development of more potent and selective HIF inhibitors will provide an effective treatment of cancer and other HIF-related diseases. So we will focus on the biological characteristics and mechanism of HIF-1 to review currently studied HIF-1 inhibitors.

[Development of a novel screening assay for inhibitors targeting HIF-1alpha and P300 interaction].

Hypoxia is a general characteristic of most solid malignancies and intimately related to cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor-1alpha (HIF-1alpha) that elicits transcriptional activity through recruitment P300 coactivator. Targeting the interaction of HIF- alpha and P300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, a screening assay was developed for inhibitors targeting the interaction between HIF-1alpha and P300. The nucleotide sequence of human HIF-1alpha and P300 were cloned into pBIND and pACT vectors, named pBIND-HIF1alpha and pACT-P300. The interaction of HIF-1alpha and P300 was identified in HEK293 cell using mammalian two-hybrid system. And compound chetomin decreased their interaction in this mammalian two-hybrid system. We further verified HIF-1 inhibition effect of chetomin in U251-HRE cells. Therefore, we established a screening assay combined HIF-1alpha and P300 mammalian two-hybrid system and U251-HRE reporter assay for HIF-1 selective inhibitors.

[A novel HIF-1 inhibitor--manassantin A derivative LXY6099 inhibits tumor growth].

Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor on hypoxia responses in mammalian tissues. HIF-1 plays as a positive factor in solid tumor and leads to hypoxia-driven responses that enhance its downstream gene expression for tumor growth and survival. LXY6099 was obtained by the structural modification and optimization of manassantin A (MA) as a high potent HIF-1 inhibitor. Antitumor activity of LXY6099 was observed in this study. LXY6099 with an IC50 value of 2.46 x 10(-10) mol x L(-1) showed more sensitive inhibition activity to HIF-1 than that of MA detected by reporter gene assay (> 100 folds). It showed strong inhibition on the growth of human solid tumor cell lines. Furthermore, LXY6099 exhibited significant antitumor activity against established human tumor xenografts in nu/nu mice with treatment of MX-1 breast cancer. Thus, LXY6099 as a novel HIF-1 inhibitor could be further developed into anti-cancer agents.

[Anti-tumor activity and mechanism of T03 in vitro and in vivo].

The purpose of this study is to investigate the activity and mechanism of a new anti-tumor agent T03. MTT and colony formation assay were performed to determine anti-proliferation activity of T03 in vitro. Antitumor activity was observed by Renca xenograft model in vivo. The effect of T03 on cell cycle and apoptosis were measured by FCM analysis. Western blotting was performed to investigate the expression level of proteins in HepG2 cell lines treated with T03. T03 had anti-tumor activity by inhibiting tumor cell growth and colony formation in vitro, especially on hepatocellular carcinoma cells (HCC). At the concentration of 10 micromol x L(-1), T03 induced cell apoptosis and cell cycle arrest in HCC. Moreover, it proved that T03 reduced the tumor weight with the rate of 42.30% without any obviously side effect in Renca xenograft model. At the concentration of 2.0 micromol x L(-1), T03 was able to reduce the level of p-c-Raf (Ser259), and thus blocked Raf/MEK/ERK and AKT signaling in HepG2 cell lines. The result suggested that T03 has the potential to inhibit cell proliferation and induce cell apoptosis both in vitro and in vivo, particularly active against HCC, indicating T03 and its analogues may serve as a new anti-cancer drug against hepatocellular carcinoma.

Decoupling the mutual promotion of inflammation and oxidative stress mitigates cognitive decline and depression-like behavior in rmTBI mice by promoting myelin renewal and neuronal survival.

BACKGROUND: Repetitive mild traumatic brain injury (rmTBI) can lead to somatic, emotional, and cognitive symptoms that persist for years after the initial injury. Although the ability of various treatments to promote recovery after rmTBI has been explored, the optimal time window for early intervention after rmTBI is unclear. Previous research has shown that hydrogen-rich water (HRW) can diffuse through the blood-brain - barrier, attenuate local oxidative stress, and reduce neuronal apoptosis in patients with severe traumatic brain injury. However, research on the effect of HRW on rmTBI is scarce. AIMS: The objectives of this study were to explore the following changes after rmTBI and HRW treatment: (i) temporal changes in inflammasome activation and oxidative stress-related protein expression through immunoblotting, (ii) temporal changes in neuron/myelin-related metabolite concentrations in vivo through magnetic resonance spectroscopy, (iii) myelin structural changes in late-stage rmTBI via immunofluorescence, and (iv) postinjury anxiety/depression-like behaviors and spatial learning and memory impairment. RESULTS: NLRP-3 expression in the rmTBI group was elevated at 7 and 14 DPI, and inflammasome marker levels returned to normal at 30 DPI. Oxidative stress persisted throughout the first month postinjury. HRW replacement significantly decreased Nrf2 expression in the prefrontal cortex and hippocampal CA2 region at 14 and 30 DPI, respectively. Edema and local gliosis in the hippocampus and restricted diffusion in the thalamus were observed on MR-ADC images. The tCho/tCr ratio in the rmTBI group was elevated, and the tNAA/tCr ratio was decreased at 30 DPI. Compared with the mice in the other groups, the mice in the rmTBI group spent more time exploring the open arms in the elevated plus maze (P < 0.05) and were more active in the maze (longer total distance traveled). In the sucrose preference test, the rmTBI group exhibited anhedonia. In the Morris water maze test, the latency to find the hidden platform in the rmTBI group was longer than that in the sham and HRW groups (P < 0.05). CONCLUSION: Early intervention with HRW can attenuate inflammasome assembly and reduce oxidative stress after rmTBI. These changes may restore local oligodendrocyte function, promote myelin repair, prevent axonal damage and neuronal apoptosis, and alleviate depression-like behavior and cognitive impairment.

HIF-1α participates in secondary brain injury through regulating neuroinflammation.

A deeper understanding of the underlying biological mechanisms of secondary brain injury induced by traumatic brain injury (TBI) will greatly advance the development of effective treatments for patients with TBI. Hypoxia-inducible factor-1 alpha (HIF-1α) is a central regulator of cellular response to hypoxia. In addition, growing evidence shows that HIF-1α plays the important role in TBI-induced changes in biological processes; however, detailed functional mechanisms are not completely known. The aim of the present work was to further explore HIF-1α-mediated events after TBI. To this end, next-generation sequencing, coupled with cellular and molecular analysis, was adopted to interrogate vulnerable events in a rat controlled cortical impact model of TBI. The results demonstrated that TBI induced accumulation of HIF-1α at the peri-injury site at 24 h post-injury, which was associated with neuronal loss. Moreover, gene set enrichment analysis unveiled that neuroinflammation, especially an innate inflammatory response, was significantly evoked by TBI, which could be attenuated by the inhibition of HIF-1α. Furthermore, the inhibition of HIF-1α could mitigate the activation of microglia and astrocytes. Taken together, all these data implied that HIF-1α might contribute to secondary brain injury through regulating neuroinflammation.

Tandem Mass Tag-based proteomics analysis reveals the vital role of inflammation in traumatic brain injury in a mouse model.

Proteomics is a powerful tool that can be used to elucidate the underlying mechanisms of diseases and identify new biomarkers. Therefore, it may also be helpful for understanding the detailed pathological mechanism of traumatic brain injury (TBI). In this study, we performed Tandem Mass Tag-based quantitative analysis of cortical proteome profiles in a mouse model of TBI. Our results showed that there were 302 differentially expressed proteins in TBI mice compared with normal mice 7 days after injury. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that these differentially expressed proteins were predominantly involved in inflammatory responses, including complement and coagulation cascades, as well as chemokine signaling pathways. Subsequent transcription factor analysis revealed that the inflammation-related transcription factors NF-κB1, RelA, IRF1, STAT1, and Spi1 play pivotal roles in the secondary injury that occurs after TBI, which further corroborates the functional enrichment for inflammatory factors. Our results suggest that inflammation-related proteins and inflammatory responses are promising targets for the treatment of TBI.

Neutrophil-derived interleukin-17A participates in neuroinflammation induced by traumatic brain injury.

After brain injury, infiltration and abnormal activation of neutrophils damages brain tissue and worsens inflammation, but the mediators that connect activated neutrophils with neuroinflammation have not yet been fully clarified. To identify regulators of neutrophil-mediated neuroinflammation after traumatic brain injury, a mouse model of traumatic brain injury was established by controlled cortical impact. At 7 days post-injury (sub-acute phase), genome-wide transcriptomic data showed that interleukin 17A-associated signaling pathways were markedly upregulated, suggesting that interleukin 17A may be involved in neuroinflammation. Double immunofluorescence staining showed that interleukin 17A was largely secreted by neutrophils rather than by glial cells and neurons. Furthermore, nuclear factor-kappaB and Stat3, both of which are important effectors in interleukin 17A-mediated proinflammatory responses, were significantly activated. Collectively, our findings suggest that neutrophil-derived interleukin 17A participates in neutrophil-mediated neuroinflammation during the subacute phase of traumatic brain injury. Therefore, interleukin 17A may be a promising therapeutic target for traumatic brain injury.

Megf10-related engulfment of excitatory postsynapses by astrocytes following severe brain injury.

AIMS: To investigate astrocyte-related phagocytosis of synapses in the ipsilateral hippocampus after traumatic brain injury (TBI). METHODS: We performed controlled cortical impact to simulate TBI in mice. Seven days postinjury, we performed cognitive tests, synapse quantification, and examination of astrocytic phagocytosis in association with Megf10 expression. RESULTS: During the subacute stage post-TBI, we found a reduction in excitatory postsynaptic materials in the ipsilateral hippocampus, which was consistent with poor performance in the cognitive test. The transcriptome data suggested that robust phagocytosis was responsible for this process. Coincidently, we identified phagocytic astrocytes containing secondary lysosomes that were wrapped around the synapses in the ipsilateral hippocampus. Moreover, a significant increase in the co-location of GFAP and PSD-95 in the CA1 region suggested astrocytic engulfment of excitatory postsynaptic proteins. After examining the reported phagocytic pathways, we found that both the transcription level and protein expression of Megf10 were elevated. Co-immunofluorescence of GFAP and Megf10 demonstrated that the expression of Megf10 was spatially upregulated in astrocytes, exclusively in the CA1 region, and was related to the astrocytic engulfment of PSD-95. CONCLUSION: Our study elaborated that the Megf10-related astrocytic engulfment of PSD-95 in the CA1 region of the ipsilateral hippocampus aggravated cognitive dysfunction following severe TBI.