The olfactory working memory capacity paradigm: A more sensitive and robust method of assessing cognitive function in male 5XFAD mice.

The olfactory working memory capacity (OWMC) paradigm is able to detect cognitive deficits in 5XFAD mice (an animal model of Alzheimer's disease [TG]) as early as 3 months of age, while other behavioral paradigms detect cognitive deficits only at 4-5 months of age. Therefore, we aimed to demonstrate that the OWMC paradigm is more sensitive and consistent in the early detection of declines in cognitive function than other commonly used behavioral paradigms. The prefrontal cortex (PFC), retrosplenial cortex (RSC), subiculum (SUB), and amygdala (AMY) of 5XFAD mice were harvested and subjected to immunostaining to detect the expression of ß-amyloid (Aß). Additionally, we compared the performance of 3-month-old male 5XFAD mice on common behavioral paradigms for assessing cognitive function (i.e., the open field [OF] test, novel object recognition [NOR] test, novel object location [NOL] test, Y-maze, and Morris water maze [MWM]) with that on the OWMC task. In the testing phase of the OWMC task, we varied the delay periods to evaluate the working memory capacity (WMC) of wild-type (WT) mice. Significant amyloid plaque deposition was observed in the PFC, RSC, SUB, and AMY of 3-month-old male 5XFAD mice. However, aside from the OWMC task, the other behavioral tests failed to detect cognitive deficits in 5XFAD mice. Additionally, to demonstrate the efficacy of the OWMC task in assessing WMC, we varied the retention delay periods; we found that the WMC of WT mice decreased with longer delay periods. The OWMC task is a sensitive and robust behavioral assay for detecting changes in cognitive function.

Role of estrogen in sex differences in memory, emotion and neuropsychiatric disorders.

Estrogen regulates a wide range of neuronal functions in the brain, such as dendritic spine formation, remodeling of synaptic plasticity, cognition, neurotransmission, and neurodevelopment. Estrogen interacts with intracellular estrogen receptors (ERs) and membrane-bound ERs to produce its effect via genomic and non-genomic pathways. Any alterations in these pathways affect the number, size, and shape of dendritic spines in neurons associated with psychiatric diseases. Increasing evidence suggests that estrogen fluctuation causes changes in dendritic spine density, morphology, and synapse numbers of excitatory and inhibitory neurons differently in males and females. In this review, we discuss the role of estrogen hormone in rodents and humans based on sex differences. First, we explain estrogen role in learning and memory and show that a high estrogen level alleviates the deficits in learning and memory. Secondly, we point out that estrogen produces a striking difference in emotional memories in men and women, which leads them to display sex-specific differences in underlying neuronal signaling. Lastly, we discuss that fluctuations in estrogen levels in men and women are related to neuropsychiatric disorders, including schizophrenia, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BPD), major depressive disorder (MDD), substance use disorder (SUD), and anxiety disorders.

Diminished activation of excitatory neurons in the prelimbic cortex leads to impaired working memory capacity in mice.

BACKGROUND: Working memory capacity impairment is an early sign of Alzheimer's disease, but the underlying mechanisms remain unclear. Clarifying how working memory capacity is affected will help us better understand the pathological mechanism of Alzheimer's disease. We used the olfactory working memory capacity paradigm to evaluate memory capacity in 3-month-old 5XFAD (an animal model of Alzheimer's disease) mice. Immunofluorescence staining of the prefrontal cortex was performed to detect the number of FOS-positive neurons, calmodulin-dependent protein kinase II-positive neurons, and glutamate decarboxylase-positive neurons in the prelimbic cortex and infralimbic cortex. A chemogenetic method was then used to modulate the inhibition and activation of excitatory neurons in the prelimbic cortex of wild-type and 5XFAD mice and to measure the memory capacity of mice. RESULTS: Working memory capacity was significantly diminished in 5XFAD mice compared to littermate wild-type mice. Neuronal activation of the prelimbic cortex, but not the infralimbic cortex, was attenuated in 5XFAD mice performing the olfactory working memory capacity task. Subsequently, the FOS-positive neurons were co-localized with both calmodulin-dependent protein kinase II-positive neurons and glutamate decarboxylase-positive neurons. The results showed that the activation of excitatory neurons in the prelimbic cortex was correlated with working memory capacity in mice. Our results further demonstrate that the chemogenetic inhibition of prelimbic cortex excitatory neurons resulted in reduced working memory capacity in wild-type mice, while the chemogenetic activation of prelimbic cortex excitatory neurons improved the working memory capacity of 5XFAD mice. CONCLUSION: The diminished activation of prelimbic cortex excitatory neurons in 5XFAD mice during task performance is associated with reduced working memory capacity, and activation modulation of excitatory neurons by chemogenetic methods can improve memory capacity impairment in 5XFAD mice. These findings may provide a new direction for exploring Alzheimer's disease therapeutic approaches.

Differential regulation of hippocampal transcriptome by circulating estrogen.

Estrogen (E2) modulates the synaptic structure and plasticity in the hippocampus. Previous studies showed that E2 fluctuations during various phases of the menstrual cycle produce subtle neurosynaptic changes that impact women's behavior, emotion, and cognitive functions. In this study, we explored the transcriptome of the hippocampus via RNA-seq (RNA-sequencing) between proestrus (PE) and diestrus (DE) stages in young female rats to determine the effect of E2 of PE and DE stages on hippocampal gene expression. We identified 238 genes (at 1.5-fold-change selection criteria, FDR adjusted p-value < 0.05) as differentially expressed genes (DEGs) that responded to E2 between PE and DE stages. Functional analysis based on Gene Ontology (GO) revealed that a higher E2 level corresponded to an increase in gene transcription among most of the DEGs, suggesting biological mechanisms operating differentially in the hippocampus of female rats between PE and DE stages in the estrus cycle; while analysis with Kyoto Encyclopedia of Genes and Genomes database (KEGG) found that the DEGs involving neuroactive ligand-receptor interaction, antigen processing, cell adhesion molecules, and presentation were upregulated in PE stage, whereas DEGs in pathways relating to bile secretion, coagulation cascades, osteoclast differentiation, cysteine and methionine metabolism were upregulated in DE stage of the estrus cycle. The high-fold expression of DEGs was confirmed by a follow-up quantitative real-time PCR. Our findings in this current study have provided fundamental information for further dissection of neuro-molecular mechanisms in the hippocampus in response to E2 fluctuation and its relationship with disorders.

Two new meroterpenoids from the bark of Cinnamomum cassia and their antioxidant activity.

Two new (1 and 2) meroterpenoids were isolated from the bark of Cinnamomum cassia. Their structures were determined by spectroscopic analyses and chemical methods. Antioxidant activities of 1 and 2 were evaluated by the ORAC and DPPH radical scavenging assays, and the results revealed that compound 2 displayed oxygen radical absorbance capacity. The discovery of compounds 1 and 2 added new members of this kind of natural product.

Ubiquitin-specific peptidase 46 (USP46) suppresses renal cell carcinoma tumorigenesis through AKT pathway inactivation.

USP46, a member of the ubiquitin-specific protease family, plays essential roles in cancer cell proliferation and metastasis and is used as a candidate target for cancer therapeutics. However, the effects of USP46 on renal cell carcinoma (RCC) and its underlying molecular mechanism remain unknown. In this study, the predictive and prognostic relevance of USP46 in RCC, patient-derived primary tissues, and normal liver tissues obtained from the TCGA dataset were analyzed for the USP46 mRNA levels or prognostic relevance. Gain-of-function or loss-of-function assays were used to evaluate the vital roles of USP46 in tumor cell proliferation and cell migration. As a result, the USP46 expression level in RCC is highly decreased compared to normal tissues, and the Kaplan-Meier curve showed that USP46 high expression patients had good prognoses. Functionally, the forced expression of USP46 significantly restrained tumor cell proliferation, colony formation, and cell migration. The shRNA mediated USP46 knockdown cells exhibited the opposite results. We further showed that ectopically expressed USP46 obviously inhibited the AKT signaling pathway in cancer cells, while USP46 depletion caused a dramatic increase in AKT activity reflected by phosphorylation in the serine and threonine residues of AKT or downstream p70S6K1. Importantly, MK2206, a specific AKT inhibitor, completely counteracted the effects on cell proliferation, cell migration, and AKT activity in the USP46 depletion cells. We thus revealed a novel mechanism of USP46 regulation in RCC, and our data indicate that USP46 is a tumor suppressor in RCC via AKT signaling pathway inactivation.

The cotton (Gossypium hirsutum) NAC transcription factor (FSN1) as a positive regulator participates in controlling secondary cell wall biosynthesis and modification of fibers.

Cotton (Gossypium hirsutum) fibers are the highly elongated and thickened single-cell trichomes on the seed epidermis. However, little is known about the molecular base of fiber cell wall thickening in detail. In this study, a cotton NAC transcription factor (GhFSN1) that is specifically expressed in secondary cell wall (SCW) thickening fibers was functionally characterized. The GhFSN1 transgenic cotton plants were generated to study how FSN1 regulates fiber SCW formation. Up-regulation of GhFSN1 expression in cotton resulted in an increase in SCW thickness of fibers but a decrease in fiber length. Transcriptomic analysis revealed that GhFSN1 activates or represses numerous downstream genes. GhFSN1 has the ability to form homodimers, binds to its promoter to activate itself, and might be degraded by the ubiquitin-mediated proteasome pathway. The direct targets of GhFSN1 include the fiber SCW-related GhDUF231L1, GhKNL1, GhMYBL1, GhGUT1 and GhIRX12 genes. GhFSN1 binds directly to a consensus sequence (GhNBS), (C/T)(C/G/T)TN(A/T)(G/T)(A/C/G)(A/G)(A/T/G)(A/T/G)AAG, which exists in the promoters of these SCW-related genes. Our data demonstrate that GhFSN1 acts as a positive regulator in controlling SCW formation of cotton fibers by activating its downstream SCW-related genes. Thus, these findings give us novel insights into comprehensive understanding of GhFSN1 function in fiber development.

A R2R3-MYB transcription factor that is specifically expressed in cotton (Gossypium hirsutum) fibers affects secondary cell wall biosynthesis and deposition in transgenic Arabidopsis.

Secondary cell wall (SCW) is an important industrial raw material for pulping, papermaking, construction, lumbering, textiles and potentially for biofuel production. The process of SCW thickening of cotton fibers lays down the cellulose that will constitute the bulk (up to 96%) of the fiber at maturity. In this study, a gene encoding a MYB-domain protein was identified in cotton (Gossypium hirsutum) and designated as GhMYBL1. Quantitative real-time polymerase chain reaction (RT-PCR) analysis revealed that GhMYBL1 was specifically expressed in cotton fibers at the stage of secondary wall deposition. Further analysis indicated that this protein is a R2R3-MYB transcription factor, and is targeted to the cell nucleus. Overexpression of GhMYBL1 in Arabidopsis affected the formation of SCW in the stem xylem of the transgenic plants. The enhanced SCW thickening also occurred in the interfascicular fibers, xylary fibers and vessels of the GhMYBL1-overexpression transgenic plants. The expression of secondary wall-associated genes, such as CesA4, CesA7, CesA8, PAL1, F5H and 4CL1, were upregulated, and consequently, cellulose and lignin biosynthesis were enhanced in the GhMYBL1 transgenic plants. These data suggested that GhMYBL1 may participate in modulating the process of secondary wall biosynthesis and deposition of cotton fibers.

A fasciclin-like arabinogalactan protein, GhFLA1, is involved in fiber initiation and elongation of cotton.

Arabinogalactan proteins (AGPs) are involved in many aspects of plant development. In this study, biochemical and genetic approaches demonstrated that AGPs are abundant in developing fibers and may be involved in fiber initiation and elongation. To further investigate the role of AGPs during fiber development, a fasciclin-like arabinogalactan protein gene (GhFLA1) was identified in cotton (Gossypium hirsutum). Overexpression of GhFLA1 in cotton promoted fiber elongation, leading to an increase in fiber length. In contrast, suppression of GhFLA1 expression in cotton slowed down fiber initiation and elongation. As a result, the mature fibers of the transgenic plants were significantly shorter than those of the wild type. In addition, expression levels of GhFLAs and the genes related to primary cell wall biosynthesis were remarkably enhanced in the GhFLA1 overexpression transgenic fibers, whereas the transcripts of these genes were dramatically reduced in the fibers of GhFLA1 RNA interference plants. An immunostaining assay indicated that both AGP composition and primary cell wall composition were changed in the transgenic fibers. The levels of glucose, arabinose, and galactose were also altered in the primary cell wall of the transgenic fibers compared with those of the wild type. Together, our results suggested that GhFLA1 may function in fiber initiation and elongation by affecting AGP composition and the integrity of the primary cell wall matrix.

Cotton KNL1, encoding a class II KNOX transcription factor, is involved in regulation of fibre development.

In this study, the GhKNL1 (KNOTTED1-LIKE) gene, encoding a classical class II KNOX protein was identified in cotton (Gossypium hirsutum). GhKNL1 was preferentially expressed in developing fibres at the stage of secondary cell wall (SCW) biosynthesis. GhKNL1 was localized in the cell nucleus, and could interact with GhOFP4, as well as AtOFP1, AtOFP4, and AtMYB75. However, GhKNL1 lacked transcriptional activation activity. Dominant repression of GhKNL1 affected fibre development of cotton. The expression levels of genes related to fibre elongation and SCW biosynthesis were altered in transgenic fibres of cotton. As a result, transgenic cotton plants produced aberrant, shrunken, and collapsed fibre cells. Length and cell-wall thickness of fibres of transgenic cotton plants were significantly reduced compared with the wild type. Furthermore, overexpression and dominant repression of GhKNL1 in Arabidopsis resulted in a reduction in interfascicular fibre cell-wall thickening of basal stems of transgenic plants. Complementation revealed that GhKNL1 rescued the defective phenotype of Arabidopsis knat7 mutant in some extent. These data suggest that GhKNL1, as a transcription factor, participates in regulating fibre development of cotton.

Cotton photosynthesis-related PSAK1 protein is involved in plant response to aphid attack.

It is believed that hundreds of genes, including photosynthesis-related genes, are typically involved in plant response to aphid feeding. Up to now, however, it is little known on the relationship between the photosynthesis-related genes and plant response to herbivores. In this study, we identified a cotton photosynthesis-related gene (GhPSAK1) which belongs to PSI-PSAK family and encodes a putative protein of 162 amino acids. RT-PCR analysis revealed that GhPSAK1 transcripts in leaves were increased at 12-24 h, but decreased at 48-72 h after cotton aphid attack or wounding induction. Choice assay and no-choice assay demonstrated that overexpression of GhPSAK1 in Arabidopsis improved plant tolerance to green peach aphids (Myzus persicae). The defense response genes related to salicylic acid signaling pathway were enhanced in the GhPSAK1 overexpressing transgenic plants. In addition, the callose amount in transgenic Arabidopsis leaves was more than that of wild type. Contents of the soluble sugars and total amino acids were also altered in leaves of transgenic Arabidopsis plants. Activities of superoxide dismutase and peroxidase in transgenic leaves were higher than those of wild type. These results suggested that GhPSAK1 may be involved in regulation of cotton response and tolerance to aphid attack.

Molecular characterization of cotton C-repeat/dehydration-responsive element binding factor genes that are involved in response to cold stress.

Low temperature, drought and salinity are major abiotic stresses that influence survival, productivity and geographical distribution of many important crops across the globe. The C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB) are important proteins involved in response to abiotic stresses in plants. In this study, twenty-one CBF genes were identified in cotton (Gossypium hirsutum) by bioinformatic approach. The twenty-one CBF genes (named as GhCBF1--GhCBF21) were characterized to encode proteins that share high similarity with those plant cold stress-related CBF proteins, which contain the classic AP2 domain of 58 amino acid residues. Phylogenetic analysis revealed that the isolated cotton CBF genes can be classified into 4 groups: GhCBF I, GhCBF II, GhCBF III and GhCBF IV. RT-PCR analysis indicated that GhCBF genes were up-regulated in cotton plants under cold stress. Furthermore, four GhCBF genes were up-regulated in cotton under salinity and drought treatments. Our data provided valuable information for further exploring the roles of the CBF genes in cotton development and in response to cold stress.

ALKBH5 suppresses autophagic flux via N6-methyladenosine demethylation of ZKSCAN3 mRNA in acute pancreatitis.

BACKGROUND: Increasing evidence has demonstrated that N6-methyladenosine (m6A) RNA modification plays an essential role in a wide range of pathological conditions. Impaired autophagy is a critical hallmark of acute pancreatitis (AP). AIM: To explore the role of the m6A modification of ZKSCAN3 in the regulation of autophagy in AP. METHODS: The AP mouse cell model was established by cerulein-treated mouse pancreatic acinar cells (MPC-83), and the results were confirmed by the levels of amylase and inflammatory factors. Autophagy activity was evaluated by specific identification of the autophagy-related microstructure and the expression of autophagy-related genes. ZKSCAN3 and ALKBH5 were knocked down to study the function in AP. A m6A RNA binding protein immunoprecipitation assay was used to study how the m6A modification of ZKSCAN3 mRNA is regulated by ALKBH. RESULTS: The increased expression of amylase and inflammatory factors in the supernatant and the accumulation of autophagic vacuoles verified that the AP mouse cell model was established. The downregulation of LAMP2 and upregulation of LC3-II/I and SQSTM1 demonstrated that autophagy was impaired in AP. The expression of ZKSCAN3 was upregulated in AP. Inhibition of ZKSCAN3 increased the expression of LAMP2 and decreased the expression of the inflammatory factors, LC3-II/I and SQSTM1. Furthermore, ALKBH5 was upregulated in AP. Knockdown of ALKBH5 downregulated ZKSCAN3 expression and restored decreased autophagic flux in AP. Notably, the bioinformatic analysis revealed 23 potential m6A modification sites on ZKSCAN3 mRNA. The m6A modification of ZKSCAN3 mRNA was significantly decreased in AP. Knockdown of ALKBH5 increased the modification of ZKSCAN3 mRNA, which confirmed that ALKBH5 upregulated ZKSCAN3 expression in a m6A-dependent manner. CONCLUSION: ALKBH5 inhibits autophagic flux through m6A demethylation of ZKSCAN3 mRNA in AP, thereby aggravating the severity of the disease.

Impairment in acquisition of conditioned fear in people with depressive symptoms.

Background: Depression is one of the primary global public health issues, and there has been a dramatic increase in depression levels among young people over the past decade. The neuroplasticity theory of depression postulates that a malfunction in neural plasticity, which is responsible for learning, memory, and adaptive behavior, is the primary source of the disorder's clinical manifestations. Nevertheless, the impact of depression symptoms on associative learning remains underexplored. Methods: We used the differential fear conditioning paradigm to investigate the effects of depressive symptoms on fear acquisition and extinction learning. Skin conductance response (SCR) is an objective evaluation indicator, and ratings of nervousness, likeability, and unconditioned stimuli (US) expectancy are subjective evaluation indicators. In addition, we used associability generated by a computational reinforcement learning model to characterize the skin conductance response. Results: The findings indicate that individuals with depressive symptoms exhibited significant impairment in fear acquisition learning compared to those without depressive symptoms based on the results of the skin conductance response. Moreover, in the discrimination fear learning task, the skin conductance response was positively correlated with associability, as estimated by the hybrid model in the group without depressive symptoms. Additionally, the likeability rating scores improved post-extinction learning in the group without depressive symptoms, and no such increase was observed in the group with depressive symptoms. Conclusion: The study highlights that individuals with pronounced depressive symptoms exhibit impaired fear acquisition and extinction learning, suggesting a possible deficit in associative learning. Employing the hybrid model to analyze the learning process offers a deeper insight into the associative learning processes of humans, thus allowing for improved comprehension and treatment of these mental health problems.

Cotton PRP5 gene encoding a proline-rich protein is involved in fiber development.

Proline-rich proteins contribute to cell wall structure of specific cell types and are involved in plant growth and development. In this study, a fiber-specific gene, GhPRP5, encoding a proline-rich protein was functionally characterized in cotton. GhPRP5 promoter directed GUS expression only in trichomes of both transgenic Arabidopsis and tobacco plants. The transgenic Arabidopsis plants with overexpressing GhPRP5 displayed reduced cell growth, resulting in smaller cell size and consequently plant dwarfs, in comparison with wild type plants. In contrast, knock-down of GhPRP5 expression by RNA interference in cotton enhanced fiber development. The fiber length of transgenic cotton plants was longer than that of wild type. In addition, some genes involved in fiber elongation and wall biosynthesis of cotton were up-regulated or down-regulated in the transgenic cotton plants owing to suppression of GhPRP5. Collectively, these data suggested that GhPRP5 protein as a negative regulator participates in modulating fiber development of cotton.

Experimental infection of non-human primates with avian influenza virus (H9N2).

Several cases of humans infected with the H9N2 avian influenza virus (AIV) have been described since 1999; however, the infectivity and pathogenicity of H9N2 in humans is not well defined. A non-human primate model in rhesus macaques was developed to study H9N2 virus infections as a means of better understanding the pathogenesis and virulence of this virus, in addition to testing antiviral drugs. Rhesus macaques inoculated with H9N2 AIV presented with biphasic fever and viral pneumonia. H9N2 was recovered from nasal washes and pharyngeal samples up to days 7-9 postinfection, followed by an increase in HI (hemagglutination inhibition) antibody titers. Tissue tropism and immunohistochemistry indicated that H9N2 AIV replicated in the upper respiratory tract (turbinate, trachea, and bronchus) and in all lobes of the lung. Our data suggest that rhesus macaques are a suitable animal model to study H9N2 influenza virus infections, particularly in the context of viral evolution and pathogenicity.

4,6-Dimethyl-pyrimidin-2-amine.

The asymmetric unit of the title compound, C6H9N3, contains three crystallographically independent mol-ecules of similar geometry. All of the mol-ecules are almost planar, with r.m.s. deviations of 0.003, 0.016 and 0.005 Å. In the crystal, the mol-ecules are linked by N-H⋯N hydrogen bonds into zigzag ribbons parallel to the c axis, generating rings of R2(2)(8) graph-set motif.

[Sequencing the complete genome of rabies virus CVS-11 strain and constructing its full-length infectious cDNA clone].

OBJECTIVE: To sequence the complete genome of CVS-11 strain and establish a reverse genetic system of CVS-11 to further study its pathogenic mechanism, virulence genes and antigenic sites. METHODS: We amplified12 fragments covering the complete genome of the CVS-11 strain by RT-PCR, and then cloned to pEASY-Blunt vector for sequencing the complete genome of CVS-11. We analyzed single restriction enzyme sites of the full length cDNA of the CVS-11 strain by DNAMAN and designed 4 pairs of specific primers. We amplified the full-length cDNA of CVS-11 by RT-PCR. We obtained four fragments and cloned into pcDNA3. 1. We named the full-length cDNA plasmid pcDNA3. 1-CVS-11. We also cloned helper plasmids pcDNA3.1-N, P, L and G expressing N, P, L and G protein of CVS-11 strain, respectively. We co-transfected NA cells with the full-length plasmid and four helper plasmids. We identified the supernatant of the transfected and then passaged NA cells by immunofluorescence staining and RT-PCR and found the recombinant virus rCVS-11 rescued successfully. RESULTS: Sequencing results showed that the complete genome of CVS-11 was composed of 11 927 nucleotides. The complete genome of CVS-11 encoded 5 structure proteins and gene array was the same as other reported rabies viruses. We successfully constructed a reverse genetic system of CVS-11, namely the full length plasmid pcDNA3. 1-CVS-11 and 4 help plasmids pcDNA3. 1-N, P, L, G and rescued the rCVS-11 from a full-length infectious cDNA clone. CONCLUSION: The reverse genetic system of the CVS-11 strain laid the foundation for future studies on rabies virus.

The neural circuits and molecular mechanisms underlying fear dysregulation in posttraumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a stress-associated complex and debilitating psychiatric disorder due to an imbalance of neurotransmitters in response to traumatic events or fear. PTSD is characterized by re-experiencing, avoidance behavior, hyperarousal, negative emotions, insomnia, personality changes, and memory problems following exposure to severe trauma. However, the biological mechanisms and symptomatology underlying this disorder are still largely unknown or poorly understood. Considerable evidence shows that PTSD results from a dysfunction in highly conserved brain systems involved in regulating stress, anxiety, fear, and reward circuitry. This review provides a contemporary update about PTSD, including new data from the clinical and preclinical literature on stress, PTSD, and fear memory consolidation and extinction processes. First, we present an overview of well-established laboratory models of PTSD and discuss their clinical translational value for finding various treatments for PTSD. We then highlight the research progress on the neural circuits of fear and extinction-related behavior, including the prefrontal cortex, hippocampus, and amygdala. We further describe different molecular mechanisms, including GABAergic, glutamatergic, cholinergic, and neurotropic signaling, responsible for the structural and functional changes during fear acquisition and fear extinction processes in PTSD.

Infection with street strain rabies virus induces modulation of the microRNA profile of the mouse brain.

BACKGROUND: Rabies virus (RABV) causes a fatal infection of the central nervous systems (CNS) of warm-blooded animals. Once the clinical symptoms develop, rabies is almost invariably fatal. The mechanism of RABV pathogenesis remains poorly understood. Recent studies have shown that microRNA (miRNA) plays an important role in the pathogenesis of viral infections. Our recent findings have revealed that infection with laboratory-fixed rabies virus strain can induce modulation of the microRNA profile of mouse brains. However, no previous report has evaluated the miRNA expression profile of mouse brains infected with RABV street strain. RESULTS: The results of microarray analysis show that miRNA expression becomes modulated in the brains of mice infected with street RABV. Quantitative real-time PCR assay of the differentially expressed miRNAs confirmed the results of microarray assay. Functional analysis showed the differentially expressed miRNAs to be involved in many immune-related signaling pathways, such as the Jak-STAT signaling pathway, the MAPK signaling pathway, cytokine-cytokine receptor interactions, and Fc gamma R-mediated phagocytosis. The predicted expression levels of the target genes of these modulated miRNAs were found to be correlated with gene expression as measured by DNA microarray and qRT-PCR. CONCLUSION: RABV causes significant changes in the miRNA expression profiles of infected mouse brains. Predicted target genes of the differentially expression miRNAs are associated with host immune response, which may provide important information for investigation of RABV pathogenesis and therapeutic method.