Gut microbial signatures of patients with diarrhea-predominant irritable bowel syndrome and their healthy relatives.

AIMS: Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder, encompassing diarrhea-predominant irritable bowel syndrome (IBS-D). Here, we utilized 16S rDNA gene sequencing to identify potential microbial drivers of IBS-D. METHODS AND RESULTS: A total of 30 healthy relatives and 27 patients with IBS-D were recruited. Clinical data and fecal samples were collected from patients and controls. 16S rDNA gene sequencing was performed to obtain fecal bacterial data. Differences in community composition were evaluated utilizing analysis of similarity (ANOSIM) using Bray-Curtis dissimilarity. The Wilcoxon rank sum test was used to compare differences in taxa and functional pathways. Finally, the key gut microbiota was identified using the random forest algorithm. Gut microbiota diversity, estimated through the Observe, Chao1, and abundance-based coverage estimator (ACE) indices, was significantly lower in the IBS-D patients than in the healthy relatives. ANOSIM analysis further confirmed significant differences in the composition of the gut microbiota between IBS-D patients and healthy relatives, with an R value of 0.106 and a P-value of 0.005. Notably, the IBS-D patients exhibited a significant enrichment of specific bacterial genera, including Fusicatenibacter, Streptococcus, and Klebsiella, which may possess potential pathogenic properties. In particular, the bacterial genus Klebsiella demonstrated a positive correlation with irritable bowel syndrome severity scoring system scores. Conversely, healthy subjects showed enrichment of bacterial genera such as Alistipes, Akkermansia, and Dialister, which may be beneficial bacteria in IBS-D. Utilizing the random forest model, we developed a discriminative model for IBS-D based on differential bacterial genera. This model exhibited impressive performance, with an area under the curve value of 0.90. Additionally, our analysis did not reveal any gender-specific differences in the microbiota community composition among IBS-D patients. CONCLUSIONS: Our findings offer preliminary insights into the potential relationship between intestinal microbiota and IBS-D. The identification model for IBS-D, grounded in gut microbiota, holds promising prospects for improving early diagnosis of IBS-D.

Plasma repressor element 1-silencing transcription factor levels are decreased in patients with Alzheimer's disease.

BACKGROUND: Repressor element 1-silencing transcription (REST)/neuron-restrictive silencer factor is considered a new therapeutic target for neurodegenerative disorders such as Alzheimer's disease (AD). However, the relationship between AD and REST remains unclear. This study aimed to 1) examine plasma REST levels and REST gene levels in AD patients and 2) further explore the pathological relationships between REST protein levels and cognitive decline in clinical conditions, including medial temporal lobe atrophy. METHODS: Participants (n = 252, mean age 68.95 ± 8.78 years) were recruited in Beijing, China, and then divided into a normal cognition (NC) group (n = 89), an amnestic mild cognitive impairment (aMCI) group (n = 79), and an AD dementia group (n = 84) according to diagnostic criteria. All participants underwent neuropsychological assessments, laboratory tests, and neuroimaging scans (magnetic resonance imaging) at baseline. Plasma REST protein levels and the distribution of REST single nucleotide polymorphisms (SNPs) were compared among the three groups. Correlations between cognitive function, neuro-imaging results, and REST levels were determined by a multivariate linear regression analysis. RESULTS: The plasma REST levels in both the NC group (430.30 ± 303.43)pg/ml and aMCI group (414.27 ± 263.39)pg/ml were significantly higher than that in the AD dementia group (NC vs AD dementia group, p = 0.034; aMCI vs AD dementia group, p = 0.033). There was no significant difference between the NC and aMCI groups (p = 0.948). No significant difference was found among the three groups regarding the genotype distribution (rs2227902 and rs3976529 SNPs) of the REST gene. The REST level was correlated with the left medial temporal lobe atrophy index (r = 0.306, p = 0.023). After 6 months of follow-up, the REST level in the NC group was positively correlated with the change in the Mini-Mental State Examination score (r = 0.289, p = 0.02). CONCLUSION: The plasma REST protein level is decreased in AD dementia patients, which is associated with memory impairment and left temporal lobe atrophy and may have potential value for clinical diagnosis of AD dementia.

METTL14-mediated N6-methyladenosine modification of SOX4 mRNA inhibits tumor metastasis in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of tumor-related death worldwide, and its main cause of death is distant metastasis. Methyltransferase-like 14(METTL14), a major RNA N6-adenosine methyltransferase, is involved in tumor progression via regulating RNA function. The goal of the study is to uncover the biological function and molecular mechanism of METTL14 in CRC. METHODS: Quantitative real-time PCR (qRT-PCR), western blot and immunohistochemical (IHC) assays were employed to detect METTL14 and SOX4 in CRC cell lines and tissues. The biological functions of METTL14 were demonstrated using in vitro and in vivo experiments. Chromatin immunoprecipitation (ChIP), Transcrptomic RNA sequencing (RNA-Seq), m6A-RNA immunoprecipitation sequencing (MeRIP-Seq), RNA immunoprecipitation and luciferase reporter assays were used to explore the mechanism of METTL14 action. RESULTS: METTL14 expression was significantly downregulated in CRC and decreased METTL14 was associated with poor overall survival (OS). Both the univariate and multivariate Cox regression analysis indicated that METTL14 was an independent prognostic factor in CRC. Moreover, lysine-specific histone demethylase 5C(KDM5C)-mediated demethylation of histone H3 lysine 4 tri-methylation(H3K4me3) in the promoter of METTL14 inhibited METTL14 transcription. Functionally, we verified that METTL14 inhibited CRC cells migration, invasion and metastasis through in vitro and in vivo assays, respectively. Furthermore, we identified SRY-related high-mobility-group box 4(SOX4) as a target of METTL14-mediated m6A modification. Knockdown of METTL14 markedly abolished SOX4 mRNA m6A modification and elevated SOX4 mRNA expression. We also revealed that METTL14-mediated SOX4 mRNA degradation relied on the YTHDF2-dependent pathway. Lastly, we demonstrated that METTL14 might inhibit CRC malignant process partly through SOX4-mediated EMT process and PI3K/Akt signals. CONCLUSIONS: Decreased METTL14 facilitates tumor metastasis in CRC, suggesting that METTL14 might be a potential prognostic biomarker and effective therapeutic target for CRC.

LRIG3 represses cell motility by inhibiting slug via inactivating ERK signaling in human colorectal cancer.

Metastasis is responsible for 90% of colorectal cancer (CRC)-related deaths. In the present study, we identified a novel key regulator of CRC metastasis, leucine-rich repeats and immunoglobulin-like domains protein 3 (LRIG3), which was significantly decreased in CRC tissues and cell lines. Downregulation of LRIG3 was attributed to copy number loss and promoter hypermethylation. Low LRIG3 expression was positively correlated with metastatic clinical features and shorter survival time. Functional experiments showed that knockout of LRIG3 markedly enhanced CRC cell migration and invasion ability, whereas reintroduction of LRIG3 exerted the opposite effects. Regarding the mechanism, LRIG3 could facilitate the binding of DUSP6 to ERK1/2, resulting in the dephosphorylation of ERK1/2 and subsequently downregulation of slug, an epithelial-to-mesenchymal transition trigger, thereby constraining CRC cell motility. Importantly, LRIG3 expression was strongly negatively correlated with slug or p-ERK1/2 expression in CRC tissues. Collectively, our data suggest that LRIG3 is a novel suppressor of CRC metastasis, reactivation of LRIG3 may be a promising therapeutic approach for metastatic CRC patients.

Memory Impairment Induced by Borna Disease Virus 1 Infection is Associated with Reduced H3K9 Acetylation.

BACKGROUND/AIMS: Borna disease virus 1 (BoDV-1) infection induces cognitive impairment in rodents. Emerging evidence has demonstrated that Chromatin remodeling through histone acetylation can regulate cognitive function. In the present study, we investigated the epigenetic regulation of chromatin that underlies BoDV-1-induced cognitive changes in the hippocampus. METHODS: Immunofluorescence assay was applied to detect BoDV-1 infection in hippocampal neurons and Sprague-Dawley rats models. The histone acetylation levels both in vivo and vitro were assessed by western blots. The acetylation-regulated genes were identified by ChIP-seq and verified by RT-qPCR. Cognitive functions were evaluated with Morris Water Maze test. In addition, Golgi staining, and electrophysiology were used to study changes in synaptic structure and function. RESULTS: BoDV-1 infection of hippocampal neurons significantly decreased H3K9 histone acetylation level and inhibited transcription of several synaptic genes, including postsynaptic density 95 (PSD95) and brain-derived neurotrophic factor (BDNF). Furthermore, BoDV-1 infection of Sprague Dawley rats disrupted synaptic plasticity and caused spatial memory impairment. These rats also exhibited dysregulated hippocampal H3K9 acetylation and decreased PSD95 and BDNF protein expression. Treatment with the HDAC inhibitor, suberanilohydroxamic acid (SAHA), attenuated the negative effects of BoDV-1. CONCLUSION: Our results demonstrate that regulation of H3K9 histone acetylation may play an important role in BoDV-1-induced memory impairment, whereas SAHA may confer protection against BoDV-1-induced cognitive impairments. This study finds important mechanism of BoDV-1 infection disturbing neuronal synaptic plasticity and inducing cognitive dysfunction from the perspective of histone modification.

Stereotactic co-axial projection imaging for augmented reality neuronavigation: a proof-of-concept study.

Background: Lack of intuitiveness and poor hand-eye coordination present a major technical challenge in neurosurgical navigation. Methods: We developed an integrated dexterous stereotactic co-axial projection imaging (sCPI) system featuring orthotopic image projection for augmented reality (AR) neurosurgical navigation. The performance characteristics of the sCPI system, including projection resolution and navigation accuracy, were quantitatively verified. The resolution of the sCPI was tested with a USAF1951 resolution test chart. The stereotactic navigation accuracy of the sCPI was measured using a calibration panel with a 7×7 circle array pattern. In benchtop validation, the navigation accuracy of the sCPI and the BrainLab Kick Navigation Station was compared using a skull phantom with 8 intracranial targets. Finally, we demonstrated the potential clinical application of sCPI through a clinical trial. Results: The resolution test showed that the resolution of the sCPI was 1.3 mm. In a stereotactic navigation accuracy test, the maximum and minimum error of the sCPI was 2.9 and 0.3 mm, and the mean error was 1.5 mm. The stereotactic navigation accuracy test also showed that the navigation error of the sCPI would increase with the pitch and yaw angle, but there was no obvious difference in navigation errors caused by different yaw directions, which meant that the navigation error is unbiased across all directions. The benchtop validation showed that the average navigation errors for the sCPI system and the Kick Navigation Station were 1.4±0.8 and 1.8±0.7 mm, the medians were 1.3 and 1.9 mm, and the average preparation times were 3 min 24 sec and 6 min 8 sec, respectively. The clinical feasibility of sCPI-assisted neurosurgical navigation was demonstrated in a clinical study. In comparison with the BrainLab device, the sCPI system required less time for preoperative preparation and enhanced the clinician experience in intraoperative visualization and navigation. Conclusions: The sCPI technique can be potentially used in many surgical applications for intuitive visualization of medical information and intraoperative guidance of surgical trajectories.

Upregulated LINC01088 facilitates malignant phenotypes and immune escape of colorectal cancer by regulating microRNAs/G3BP1/PD-L1 axis.

PURPOSE: Long intergenic non-coding RNA LINC01088 is a newly discovered long non-coding RNA (lncRNA). Its biological function in colorectal cancer (CRC) remains unknown. METHODS: Here, 36 paired CRC and para-cancerous tissues were collected. In vitro, fluorescence in situ hybridization (FISH) assay, qPCR, western blotting analysis and cellular functional experiments, RNA immunoprecipitation (RIP) assay and dual-luciferase reporter system analysis were performed. In vivo, xenograft tumor mouse models were generated. Besides, patient-derived intestinal organoid (PDO) was generated ex vivo. RESULTS: We found that LINC01088 was significantly upregulated in colorectal cancer tissues and CRC cell lines compared to adjacent normal tissues and colonic epithelial cells. High LINC01088 levels were correlated with adverse outcomes in patients with CRC. LINC01088 was mainly located in the cytoplasm. LINC01088 knockdown suppressed the proliferation, migration, invasion, and immune escape of colorectal cancer cells. Mechanistically, LINC01088 bound directly to miR-548b-5p and miR-548c-5p that were significantly upregulated Ras GTPase-activating protein-binding proteins 1 (G3BP1) and programmed death ligand 1 (PD-L1) expression, altering CRC cell phenotypes. In mouse xenograft models, LINC01088 knockdown restrained CRC tumor growth and lung metastasis. Furthermore, G3BP1 overexpression reversed LINC01088-knockdown-mediated inhibitory effects on tumor growth. Notably, LINC01088 knockdown downregulated PD-L1 expression, while G3BP1 overexpression restored PD-L1 expression in xenograft tumors. Besides, LINC01088 knockdown repressed CRC organoid growth ex vivo. CONCLUSION: Overall, these findings suggested that LINC01088 directly targeted miR-548b-5p and miR-548c-5p, promoting G3BP1 and PD-L1 expression, which facilitated colorectal cancer progression and immune escape.

Co-axial Projective Imaging for Augmented Reality Telementoring in Skin Cancer Surgery.

Telemedicine has the potential to overcome the unequal distribution of medical resources worldwide. In this study, we report the second-generation co-axial projective imaging (CPI-2) system featured with orthotopic image projection for augmented reality surgical telementoring. The CPI-2 system can acquire surgical scene images from the local site, transmit them wirelessly to the remote site, and project the virtual annotations drawn by a remote expert with great accuracy to the surgical field. The performance characteristics of the CPI-2 system are quantitatively verified in benchtop experiments. The ex vivo study that compares the CPI-2 system and a monitor-based telementoring system shows that the CPI-2 system can reduce the focus shift and avoid subjective mapping of the instructions from a monitor to the real-world scene, thereby saving operation time and achieving precise teleguidance. The clinical feasibility of the CPI-2 system is validated in teleguided skin cancer surgery. Our ex vivo and in vivo experiment results imply the improved performance of surgical telementoring, and the clinical utility of deploying the CPI-2 system for surgical interventions in resource-limited settings. The CPI-2 system has the potential to reduce healthcare disparities in remote areas with limited resources.

Retraction Notice to: YTHDF1 Facilitates the Progression of Hepatocellular Carcinoma by Promoting FZD5 mRNA Translation in an m6A-Dependent Manner.

[This retracts the article DOI: 10.1016/j.omtn.2020.09.036.].

mRNA expression level of CDH2, LEP, POSTN, TIMP1 and VEGFC modulates 5-fluorouracil resistance in colon cancer cells.

Drug resistance severely affects the clinical efficacy of therapeutic agents in patients with colon cancer. The aim of the present study was to identify genes involved in drug resistance in colon cancer using bioinformatics analysis and to identify the underlying mechanisms in vitro. Genes associated with cancer recurrence and chemotherapy resistance were identified using data mining. Immunohistochemistry was performed to analyze the protein expression level of genes of interest in human colon cancer tissues. Reverse transcription-quantitative PCR analysis was performed to analyze the gene expression level in patient samples and in colon cancer cell lines (HCT116 and LoVo). Cell viability was evaluated using the Cell Counting Kit-8 assay in the colon cancer cell lines. Apoptosis was measured using PI staining. The results from the present study revealed 602 genes using both 'cancer recurrence' and 'chemoresistance' terms on the GenCLiP3 website. Gene functional annotation was performed using the Database for Annotation, Visualization and Integrated Discovery then, the protein-protein interaction networks of the 602 genes were analyzed using STRING analysis. Further, in the GEPIA database, 14 genes (ATM, CDH2, CDKN2A, EPO, LEP, TGFB1, TIMP1, PGR, VEGFC, POSTN, BCL6, CYP19A1, NOTCH3 and XPA) were found to be upregulated in colon cancer tissue and were associated with poor prognosis in patients with colon cancer. Further analysis of 33 paired human colon cancer tissues revealed that 8 genes (ATM, CDH2, CDKN2A, LEP, PGR, TIMP1, POSTN and VEGFC) were significantly upregulated, which was consistent with the results obtained from the earlier analysis and 5 genes (CDH2, LEP, POSTN, TIMP1 and VEGFC) were associated with patient prognosis. Silencing of these 5 genes using small interfering RNAs significantly enhanced the sensitivity of colon cancer cells to the chemotherapeutic agent, 5-fluorouracil (5-FU). Taken together, the results suggested that CDH2, LEP, POSTN, TIMP1 and VEGFC might play a role in chemotherapeutic resistance in colon cancer and represent potential targets for overcoming 5-FU resistance in colon cancer.

Long intergenic non-coding RNA LINC00485 exerts tumor-suppressive activity by regulating miR-581/EDEM1 axis in colorectal cancer.

Long non-coding RNAs (lncRNA) play a vital role in colorectal cancer (CRC) progression. To investigate the role of long intergenic non-coding RNA LINC00485 in CRC, we performed in vitro functional experiments. LoVo tumor-bearing and liver metastasis mice were used as in vivo models. We found that LINC00485 expression was significantly lower in CRC tissues and cancer cells than in paired normal samples and human normal colonic epithelial cells. Lower expression of LINC00485 predicted poor prognosis in CRC patients. LINC00485 knockdown promoted the proliferation, migration, and invasion of FHC cells, while LINC00485 overexpression weakened these abilities of LoVo cells. MicroRNA miR-581 was the downstream target of LINC00485, which was downregulated in CRC samples and cancer cells compared to normal tissues and normal colonic epithelial cells. MiR-581 overexpression induced proliferation, migration, and invasion of FHC cells, while miR-581 antagomir treatment produced opposite results. MiR-581 directly targeted the 3'UTR of EDEM1 and inhibited its expression and induction of epithelial-mesenchymal transition of CRC. In mouse models, LINC00485 knockdown or down-regulation of miR-581 significantly repressed CRC cell growth and prevented CRC liver metastasis. Overall, LINC00485 suppressed CRC tumorigenesis and progression by targeting the miR-581/EDEM1 axis. LINC00485 may be a potential therapeutic target for CRC.

A Wearable Augmented Reality Navigation System for Surgical Telementoring Based on Microsoft HoloLens.

This paper reports a new type of augmented reality (AR) system that integrates a Microsoft HoloLens device with a three-dimensional (3D) point tracking module for medical training and telementored surgery. In this system, a stereo camera is used to track the 3D position of a scalpel and transfer its coordinates wirelessly to a HoloLens device. In the scenario of surgical training, a virtual surgical scene with pre-recorded surgical annotations is superimposed with the actual surgical scene so that the surgical trainee is able to operate following virtual instructions. In the scenario of telementored surgery, the virtual surgical scene is co-registered with the actual surgical scene so that the virtual scalpel remotely mentored by an experienced surgeon provides the AR guidance for the inexperienced on-site operator. The performance characteristics of the proposed AR telementoring system are verified by benchtop experiments. The clinical applicability of the proposed system in telementored skin grafting surgery and fasciotomy is validated in a New Zealand rabbit model. Our benchtop and in vivo experiments demonstrate the potential to improve surgical performance and reduce healthcare disparities in remote areas with limited resources.

YTHDF1 Facilitates the Progression of Hepatocellular Carcinoma by Promoting FZD5 mRNA Translation in an m6A-Dependent Manner.

Hepatocellular carcinoma (HCC), one of the most aggressive malignancies, ranks as the fourth leading cause of cancer-related deaths worldwide. Emerging evidence indicates that RNA N6-methyladenosine (m6A) plays a critical role in tumor progression. However, the biological function of YTHDF1 in HCC remains unclear. Here, we found that YTHDF1 expression was strikingly elevated in HCC tissues and cell lines and significantly associated with prognosis of HCC patients. Moreover, YTHDF1 expression was transcriptionally regulated by USF1 and c-MYC in HCC. Functional studies showed that YTHDF1 can promote HCC cell proliferation and metastasis both in vitro and in vivo. Multi-omics analysis revealed that YTHDF1 can accelerate the translational output of FZD5 mRNA in an m6A-dependent manner and function as an oncogene through the WNT/ß-catenin pathway. Taken together, our study revealed an essential role of YTHDF1 in the progression of HCC cells, which indicated that targeting YTHDF1 may be a potential therapeutic strategy in HCC.

Analysis of METTL3 and METTL14 in hepatocellular carcinoma.

N6-methyladenosine (m6A) RNA methylation is the most prevalent modification of messenger RNAs (mRNAs) and catalyzed by a multicomponent methyltransferase complex (MTC), among which methyltransferase-like 3 (METTL3) and METTL14 are two core molecules. However, METTL3 and METTL14 play opposite regulatory roles in hepatocellular carcinoma (HCC). Based on The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database, we conducted a multi-omics analysis of METTL3 and METTL14 in HCC, including RNA-sequencing, m6ARIP-sequencing, and ribosome-sequencing profiles. We found that the expression and prognostic value of METTL3 and METTL14 are opposite in HCC. Besides, after METTL3 and METTL14 knockdown, most of the dysregulated mRNAs, signaling pathways and biological processes are distinct in HCC, which partly explains the contrary regulatory role of METTL3 and METTL14. Intriguingly, these mRNAs whose stability or translation efficiency are influenced by METTL3 or METTL14 in an m6A dependent manner, jointly regulate multiple signaling pathways and biological processes, which supports the cooperative role of METTL3 and METTL14 in catalyzing m6A modification. In conclusion, our study further clarified the contradictory role of METTL3 and METTL14 in HCC.

Handheld projective imaging device for near-infrared fluorescence imaging and intraoperative guidance of sentinel lymph node resection.

We propose a handheld projective imaging device for orthotopic projection of near-infrared fluorescence images onto target biological tissue at visible wavelengths without any additional visual aid. The device integrates a laser diode light source module, a camera module, a projector, an ultrasonic distance sensor, a Raspberry Pi single-board computer, and a battery module in a rugged handheld unit. It is calibrated at the detected working distance for seamless coregistration between fluorescence emission and projective imaging at the target tissue site. The proposed device is able to achieve a projection resolution higher than 314 µm and a planar projection bias less than 1 mm at a projection field of view of 58 × 108 mm2 and a working distance of 27 cm. Technical feasibility for projective imaging is verified in an ex vivo model of chicken breast tissue using indocyanine green as a fluorescence agent. Clinical utility for image-guided surgery is demonstrated in a clinical trial where sentinel lymph nodes in breast cancer patients are identified and resected under the guidance of projective imaging. Our ex vivo and in vivo experiments imply the clinical utility of deploying the proposed device for image-guided surgical interventions in resource-limited settings.

Integrating T7 RNA Polymerase and Its Cognate Transcriptional Units for a Host-Independent and Stable Expression System in Single Plasmid.

Metabolic engineering and synthetic biology usually require universal expression systems for stable and efficient gene expression in various organisms. In this study, a host-independent and stable T7 expression system had been developed by integrating T7 RNA polymerase and its cognate transcriptional units in single plasmid. The expression of T7 RNA polymerase was restricted below its lethal threshold using a T7 RNA polymerase antisense gene cassette, which allowed long periods of cultivation and protein production. In addition, by designing ribosome binding sites, we further tuned the expression capacity of this novel T7 system within a wide range. This host-independent expression system efficiently expressed genes in five different Gram-negative strains and one Gram-positive strain and was also shown to be applicable in a real industrial d- p-hydroxyphenylglycine production system.

Bacteriophage T7 transcription system: an enabling tool in synthetic biology.

Since its discovery in the 1970s, the T7 RNA polymerase (T7 RNAP) transcription system has been applied extensively as an effective tool in molecular biology because of its robust function in various hosts, including prokaryotic, eukaryotic and cell free systems. Recently, the T7 RNAP transcription system has emerged as a critical component for synthetic biology. The present paper summarizes the advances of the T7 RNAP transcription system in synthetic biology, including the recent progress of T7 RNAP structure and its cognate promoter and terminator and its application in cell free systems, logic gates and orthogonal genetic circuits.

Activation of ERK/CREB/BDNF pathway involved in abnormal behavior of neonatally Borna virus-infected rats.

BACKGROUND: Neuropsychiatric disorders are devastating illnesses worldwide; however, the potential involvement of viruses in the pathophysiological mechanisms of psychiatric diseases have not been clearly elucidated. Borna disease virus (BDV) is a neurotropic, noncytopathic RNA virus. MATERIALS AND METHODS: In this study, we infected neonatal rats intracranially with BDV Hu-H1 and Strain V within 24 hours of birth. Psychological phenotypes were assessed using sucrose preference test, open field test, elevated plus maze test, and forced swim test. The protein expression of ERK/CREB/BDNF pathway was assessed by Western blotting of in vitro and in vivo samples. RESULTS: Hu-H1-infected rats showed anxiety-like behavior 8 weeks postinfection while Strain V-infected rats demonstrated a certain abnormal behavior. Phosphorylated ERK1/2 was significantly upregulated in the hippocampi of Strain V- and Hu-H1-infected rats compared with control rats, indicating that Raf/MEK/ERK signaling was activated. CONCLUSION: The data suggested that infection of neonatal rats with BDV Hu-H1 and Strain V caused behavioral abnormalities that shared common molecular pathways, providing preliminary evidences to investigate the underlying mechanisms of psychiatric disorders caused by BDV.

Recombinant tissue plasminogen activator induces long-term anxiety-like behaviors via the ERK1/2-GAD1-GABA cascade in the hippocampus of a rat model.

OBJECTIVES: Recombinant tissue plasminogen activator (rtPA) is widely used for patients with thromboembolic disease, and increasing evidence indicates that it can directly induce neurotoxicity independent of its thrombolysis property. Here, we aimed to confirm the long-term effect of rtPA on animal's behavior, and investigate the underlying pathogenesis. METHODS AND RESULTS: Male Sprague-Dawley rats randomly received a dose of rtPA (10 mg/kg) or sterile saline. Three months later, the animals receiving rtPA displayed anxiety-like behaviors in the open field and novelty-suppressed feeding tests. To investigate the possible pathogenesis, gas chromatography-mass spectrometry-based metabolomics analysis was performed, with 18 differential metabolites identified in the hippocampus 24 h after the treatments. Based upon these differential metabolites, a metabolite-protein integrated network was generated, which indicated that ERK1/2-glutamic acid decarboxylase (GAD) 1-γ aminobutyric acid (GABA) cascade may be related to long-term anxiety-like behaviors. The GABA levels in hippocampus were decreased 24 h post-treatment and three months later, confirmed by a high performance liquid chromatography method. We also examined the expression of GAD1 and GAD2 using western blotting or immunohistochemical staining. Levels of GAD1 were persistently decreased after treatment, while GAD2 levels, GAD1-immunoreactive, and GAD2-immunoreactive neurons showed no significant differences. The underlying pathogenesis also involved activation of ERK1/2, confirmed by increased phospho-ERK1/2 24 h post-treatment. CONCLUSIONS: RtPA can induce long-term anxiety-like behaviors after a clinical injected dose. The underlying pathogenesis involves the ERK1/2-GAD1-GABA cascade in the hippocampus. This pharmacological side effect of rtPA may further exacerbate post-stroke anxiety disorder for stroke patients.

iTRAQ-based proteomics suggests LRP6, NPY and NPY2R perturbation in the hippocampus involved in CSDS may induce resilience and susceptibility.

AIMS: Although decades of research have revealed numerous molecular abnormalities in the hippocampus associated with depression, the different mechanisms involved in the susceptibility and resilience of mice to chronic social defeat stress (CSDS)-induced depression remain poorly understand. Through the social defeat model, we can study the differences in molecular changes between the susceptible and resilient mice. MAIN METHODS: We used a proteomic-based platform to compare hippocampal proteins in CSDS mice with those in control mice. Differentially expressed proteins were identified through isobaric tags for relative and absolute quantitation (iTRAQ) combined with LC-MS/MS. We then analyzed the results by ingenuity pathway analysis (IPA) and verified five proteins by western blotting. KEY FINDINGS: Mice were exposed to 10 days of CSDS, which successfully induced stress-susceptible and -resilient phenotypes. 161 and 134 proteins were significantly differentially expressed in the susceptible and resilient groups, respectively, compared with the levels in the control group. The Rac signaling and the GABA receptors signaling pathways were the common top-ranking pathways. We found that low-density lipoprotein receptor-related protein 6 (LRP6) was upregulated in resilient mice and neuropeptide Y (NPY) was downregulated in susceptible mice compared with the levels in control mice. Moreover, neuropeptide Y receptor type 2 (NPY2R) protein expression in susceptible mice was downregulated compared with that in the resilient group. SIGNIFICANCE: Our findings in the three groups potentially reveal the differences in molecular mechanisms underlying depression between susceptible and resilient mice. The results provide insight into molecular abnormalities of the hippocampus in CSDS mice and some potential drug targets for treating depression.