Feedforward inhibition of stress by brainstem neuropeptide Y neurons.

Resistance to stress is a key determinant for mammalian functioning. While many studies have revealed neural circuits and substrates responsible for initiating and mediating stress responses, little is known about how the brain resists to stress and prevents overreactions. Here, we identified a previously uncharacterized neuropeptide Y (NPY) neuronal population in the dorsal raphe nucleus and ventrolateral periaqueductal gray region (DRN/vlPAG) with anxiolytic effects in male mice. NPYDRN/vlPAG neurons are rapidly activated by various stressful stimuli. Inhibiting these neurons exacerbated hypophagic and anxiety responses during stress, while activation significantly ameliorates acute stress-induced hypophagia and anxiety levels and transmits positive valence. Furthermore, NPYDRN/vlPAG neurons exert differential but synergic anxiolytic effects via inhibitory projections to the paraventricular thalamic nucleus (PVT) and the lateral hypothalamic area (LH). Together, our findings reveal a feedforward inhibition neural mechanism underlying stress resistance and suggest NPYDRN/vlPAG neurons as a potential therapeutic target for stress-related disorders.

Sublethal Effects of Emamectin Benzoate on Development and Reproduction and RNAi of the Vitellogenin Gene in Spodoptera frugiperda.

Spodoptera frugiperda, one of the most destructive corn pests in the world, invaded China in December 2018. In this study, sublethal concentrations (LC10 and LC30) of emamectin benzoate (EB) were used to treat pesticide-free treatment (PFT) and EB treatment (ET) of S. frugiperda. In PFT, compared with the control (CK), the pupal weight, hatching rate, and pupation rate of LC10 and LC30 groups were significantly reduced. The fecundity and the expression of vitellogenin gene (SfVg) were decreased after LC30 treatment, while the LC10 treatment groups showed no significant difference from the control group. In ET, compared to CK, the fecundity was increased by 11.14 and 18.8%. The expression of SfVg was upregulated by 2.6 times after LC30 treatment. Moreover, RNAi-mediated SfVg knockdown resulted in a nearly 70% reduction in oviposition. The result provided a theoretical basis for optimizing the application of EB and Vg-dsRNA in the control of S. frugiperda.

Circuit- and laminar-specific regulation of medial prefrontal neurons by chronic stress.

BACKGROUND: Chronic stress exposure increases the risk of mental health problems such as anxiety and depression. The medial prefrontal cortex (mPFC) is a hub for controlling stress responses through communicating with multiple limbic structures, including the basolateral amygdala (BLA) and nucleus accumbens (NAc). However, considering the complex topographical organization of the mPFC neurons in different subregions (dmPFC vs. vmPFC) and across multiple layers (Layer II/III vs. Layer V), the exact effects of chronic stress on these distinct mPFC output neurons remain largely unknown. RESULTS: We first characterized the topographical organization of mPFC neurons projecting to BLA and NAc. Then, by using a typical mouse model of chronic restraint stress (CRS), we investigated the effects of chronic stress on the synaptic activity and intrinsic properties of the two mPFC neuronal populations. Our results showed that there was limited collateralization of the BLA- and NAc-projecting pyramidal neurons, regardless of the subregion or layer they were situated in. CRS significantly reduced the inhibitory synaptic transmission onto the BLA-projecting neurons in dmPFC layer V without any effect on the excitatory synaptic transmission, thus leading to a shift of the excitation-inhibition (E-I) balance toward excitation. However, CRS did not affect the E-I balance in NAc-projecting neurons in any subregions or layers of mPFC. Moreover, CRS also preferentially increased the intrinsic excitability of the BLA-projecting neurons in dmPFC layer V. By contrast, it even caused a decreasing tendency in the excitability of NAc-projecting neurons in vmPFC layer II/III. CONCLUSION: Our findings indicate that chronic stress exposure preferentially modulates the activity of the mPFC-BLA circuit in a subregion (dmPFC) and laminar (layer V) -dependent manner.

Activation of triggering receptor expressed on myeloid cells-1 protects monocyte from apoptosis through regulation of myeloid cell leukemia-1.

BACKGROUND: Triggering receptor expressed on myeloid cells-1 (TREM-1) can amplify the proinflammatory response and may contribute to the pathogenesis of inflammatory disease such as sepsis. However, the role of TREM-1 in monocyte fate and the detailed molecular mechanisms evoked by TREM-1 are unknown. METHODS: Adenoviruses overexpressing TREM-1 were constructed and transfected into a monocytic cell line. After activation of TREM-1 by agonist antibody with or without lipopolysaccharide, apoptosis was induced and assayed using flow cytometry. The signaling pathways downstream of TREM-1 were illustrated by inhibitory experiments. Proapoptotic/antiapoptotic protein levels were measured using immunoblot. In addition, the relationship between the expression levels of TREM-1 in monocytes and the magnitude of monocyte apoptosis were analyzed in septic patients. RESULTS: Activation of TREM-1 protected monocytes from staurosporine-induced apoptosis. This characteristic was also obtained under lipopolysaccharide stimulation. The protection of TREM-1 against monocyte apoptosis was abrogated after inhibition of extracellular signal-regulated kinase or v-akt murine thymoma viral oncogene homologue signaling. Cross-linking of TREM-1 remarkably up-regulated myeloid cell leukemia-1 protein level, and inhibition of extracellular signal-regulated kinase or v-akt murine thymoma viral oncogene homologue resulted in the reduction of myeloid cell leukemia-1 expression. Inhibition of myeloid cell leukemia-1 abolished the antiapoptotic effect of TREM-1. Furthermore, in septic patients, TREM-1 levels were inversely correlated to the magnitude of apoptosis in monocyte. CONCLUSIONS: TREM-1 played an important role in apoptosis in monocytes. Activation of TREM-1 protected monocytic cells from apoptosis through activation of both extracellular signal-regulated kinase and v-akt murine thymoma viral oncogene homologue pathways and increased expression of myeloid cell leukemia-1 protein. These findings provide a novel additional mechanism for TREM-1-mediated hyperinflammatory response in monocytes.

Subtype-specific, probe-based, real-time PCR for detection and typing of human herpesvirus-6 encephalitis from pediatric patients under the age of 2 years.

To investigate the frequency of human herpesvirus-6 (HHV-6) encephalitis in pediatric patients under 2 years of age, we developed a method for the simultaneous detection and differentiation of the 2 variants of HHV-6 (HHV-6A and HHV-6B) using subtype-specific, probe-based, real-time PCR (SSPBRT-PCR) and which were further evaluated on 405 cerebrospinal fluid (CSF) specimens from children with suspected encephalitis. A total of 23 (5.70%) out of 405 CSF specimens were positive by SSPBRT-PCR, including 3 cases of HHV-6A and 20 cases of HHV-6B. The positive rate of HHV-6B was significantly higher than that of HHV-6A (P = 0.0004). Compared with the results of the conventional real-time PCR, the sensitivity and specificity of the SSPBRT-PCR assay were 95.24% and 99.22%, respectively. This study suggests a role for both variants of HHV-6 in the pathogenesis of viral encephalitis. SSPBRT-PCR can provide rapid, sensitive, and specific results for identification of HHV-6A and HHV-6B and management of HHV-6 encephalitis.

Rapid diagnosis of herpetic encephalitis in children by PCR-microarray technology for simultaneous detection of seven human herpes viruses.

The aim of the study was to evaluate retrospectively the usefulness of polymerase chain reaction (PCR)-microarray technology, which can simultaneously detect seven human herpes viruses for rapid and accurate diagnosis of herpetic encephalitis in children. We simultaneously amplified herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2); varicella-zoster virus; Epstein-Barr virus (EBV); cytomegalovirus (CMV); and human herpes virus 6 (HHV-6A and HHV-6B) by multiplex PCR, and genotyped by DNA microarray technology. The multiplex primers and oligonucleotide probes were designed and synthesized based on the highly conserved regions of the DNA polymerase gene in human herpes viruses. Two hundred ninety cerebrospinal fluid (CSF) specimens from children with clinical suspicion of viral encephalitis were screened by PCR-microarray technology. The results were compared with those of TaqMan PCR kits of common herpes virus. The PCR-microarray technology could detect as few as 10 copies of viral loads. There was no nonspecific hybridizing signal between probes and no cross-reaction to DNA extracted from the pathogens we used. Of 290 cases, 11 were tested positive by PCR-microarray technology. Among them, three were positive for HSV-1, two were positive for HSV-2, one was positive for EBV, two were positive for CMV, two were positive for HHV-6A, one was positive for HHV-6B, and one showed mixed infection of HSV-2 and CMV, and the positive rate was 3.8%. Compared with the results of TaqMan PCR, the sensitivity of PCR-microarray technology was 91.7%, the specificity was 100%, and the index of accurate diagnosis was 0.917. None of the 30 control CSF specimens was tested positive in both methods. Our study suggests that the simultaneous detection of seven human herpes viruses by PCR-microarray technology is the method of choice for rapid, accurate, and specific etiological diagnosis of herpetic encephalitis in children.

[Establishment and clinical application of a new real time PCR assay for simultaneous detection of human herpesvirus-6A and human herpesvirus-6B].

OBJECTIVE: Human herpesvirus 6 (HHV-6) isolates are classified into two variants, HHV-6A and HHV-6B, based on distinct genetic, antigenic and biological characteristics. HHV-6 has been associated with encephalitis in children recently. This study aimed to establish a real time PCR assay for simultaneous detection of the two subtypes of HHV-6, and apply this new assay to children with suspected encephalitis, then analyze the relationship between the infection with HHV-6 and encephalitis in children. METHOD: The universal primers and variant-specific TaqMan probes were designed based on the highly conserved sequences of the DNA polymerase gene (U38) of HHV-6. The 5' end of the probes for HHV-6A and HHV-6B was labeled with the fluorescein reporter tetrachloro-6-carboxyfluorescein and 6-carboxyfluorescein (6-FAM), separately, while the 3' end were quenched with 6-carboxy-tetramethylrhodamine. The real time PCR assay for simultaneous detection of HHV-6A and HHV-6B was established. Then, the plasmids of HHV-6A and -6B which were diluted by a 10-fold series from 10(9) to 10(0) copies/microl, together with controls were used for testing both sensitivity and specificity of the real time PCR assay. The cerebrospinal fluid (CSF) specimens from 445 cases of suspected encephalitis were tested with this real time PCR and positive samples were then sequenced. RESULT: Both HHV-6A (strain ZJ-159) and HHV-6B (strain GS) were positive on the real time PCR assay. There were no cross-reaction with herpes simplex virus type 1, type 2 (HSV-1, HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), hepatitis B virus, Staphylococcus aureus, Mycoplasma pneumoniae and human DNA. A linear regression curve was obtained when plotting Ct values against the log10 of the viral DNA input for both subtypes of HHV-6. The sensitivity threshold was 10 copies/microl for the real time PCR. HHV-6 positive rate by the real time PCR assay was 4.72% (21/445), including 4 cases with HHV-6A infection, 16 cases of HHV-6B infection and 1 case with mixed HHV-6A and HHV-6B infection. The new PCR assay usually took 2 to 3 hours to provide results. CONCLUSION: This new real time PCR assay can simultaneously detect both subtypes of HHV-6, and have high specificity and sensitivity. It will provide an early and sensitive diagnosis of HHV-6 encephalitis in children.

Rapid diagnosis of sepsis and bacterial meningitis in children with real-time fluorescent quantitative polymerase chain reaction amplification in the bacterial 16S rRNA gene.

A method for the detection of bacterial pathogens in sepsis and bacterial meningitis with 16S rRNA gene- based real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) is developed. A total of 190 blood specimens and 5 cerebrospinal fluid specimens from neonates with suspected sepsis or bacterial meningitis were evaluated with 16S rRNA gene-based real-time FQ-PCR assay. The positive rate of the real-time FQ-PCR assay was significantly higher (25/195, 12.82%) than that of bacterial culture (15/195, 7.69%; P = .002). When bacterial culture was used as a control, the sensitivity of the real-time FQ-PCR was 100%, the specificity was 94.4%, and Youden's index was 0.944. This study suggests that 16S rRNA gene-based real-time FQ-PCR assay is an important and accurate method in the detection of bacterial pathogens of sepsis and bacterial meningitis and should have a promising usage in the diagnosis of sepsis and bacterial meningitis.