The PTB and PRR domains of numb regulate neurite outgrowth by influencing voltage-gated calcium channel expression and kinetics.

Numb is an evolutionarily conserved protein that regulates the differentiation of neuronal progenitor cells through unknown mechanisms. Numb has four alternative splice variants with different lengths of phosphotyrosine-binding (PTB) and proline-rich regions (PRR) domains. In this study, we demonstrated that Numb expression was increased in the primary cultures of rat cortical and hippocampal neurons over time in vitro, and Numb antisense inhibited neurite outgrowth. We verified that cells overexpressing short PTB (SPTB) or long PTB (LPTB) domains exhibited differentiation or proliferation, respectively. SPTB-mediated differentiation was related to the PRR domains, as cells expressing SPTB/LPRR had longer dendrites and more branched dendrites than cells expressing SPTB/SPRR. The differentiation of both cell types was completely blocked by the Ca2+ chelator. Western blot analysis revealed the increased total protein expression of voltage-gated calcium channel (VGCC) subunit α1C and α1D in cells expressing SPTB and LPTB Numb. The increased expression of the VGCC ß3 subunit was only observed in cells expressing SPTB Numb. Immunocytochemistry further showed that SPTB-mediated cell differentiation was associated with increased membrane expression of VGCC subunits α1C, α1D and ß3, which corresponded to the higher Ca2+ current (ICa) densities. Furthermore, we found that VGCC of cells transfected with SPTB/SPRR or SPTB/LPRR Numb isoforms exhibit steady-state inactivation (SSI) in both differentiated and undifferentiated phenotypes. A similar SSI of VGCC was observed in the differentiated cells transfected with SPTB/SPRR or SPTB/LPRR Numb isoforms, whereas a left shift SSI of VGCC in cells expressing SPTB/LPRR was detected in the undifferentiated cells. Collectively, these data indicate that SPTB domain is essential for neurite outgrowth involving in membrane expression of VGCC subunits, and LPRR plays a role in neuronal branching and the regulation of VGCC inactivation kinetics.

The Function, Underlying Mechanism and Clinical Potential of Exosomes in Colorectal Cancer.

Colorectal cancer (CRC) is a lethal malignancy worldwide. Exosomes are extracellular vesicles derived from the endosomal pathway of nearly all cells and can be found in body fluids. They can be considered an intercellular system in the human body that can mediate near- and long-distance intercellular communication due to their features and functions. Investigations have revealed that exosomes are participated in different processes, physiologically and pathologically, especially in cancer. However, the clinical value of exosomes and their mechanisms of action in CRC are unclear and have not been systematically assessed. The purpose of this review is to discuss how exosomes play a role in the occurrence and development of CRC, with a particular focus on the functions and underlying mechanisms of tumor-derived exosomes as well as non-tumor-derived exosomes. We also describe the evidence that exosomes can be used as diagnostic and prognostic markers for CRC. In addition, the possibilities of exosomes in CRC clinical transformation are also discussed.

Isolation and Identification of Novel Highly Pathogenic Avian Influenza Virus (H5N8) Subclade 2.3.4.4b from Geese in Northeastern China.

H5N8, a highly pathogenic avian influenza, has become a new zoonotic threat in recent years. As of December 28, 2021, at least 3,206 H5N8 cases had been reported in wild birds and poultry worldwide. In January 2021, a novel virus strain named A/goose/China/1/2021 was isolated during an H5N8 goose influenza outbreak in northeastern China. The PB2, PB1, HA, and M genes of A/goose/China/1/2021 were highly identical to those of H5N8 strains emerging in Kazakhstan and Russia in Central Asia from August to September 2020, while the remaining four genes had the closest homology to those of H5N8 viruses isolated in South Korea in East Asia from November to December 2020. We thus speculate that A/goose/China/1/2021 is likely a reassortant virus that formed in the 2020 to 2021 influenza season and that the migratory birds via the two migration routes of Central Asia and East Asia-Australia may have played an essential role in the genetic reassortment of this virus. The phylogenetic analysis indicated that the HA genes of H5N8 viruses belonging to group II of subclade 2.3.4.4b, including A/goose/China/1/2021, may be derived from strains in Central Asia. Given the complex global spread of H5N8 virus, our study highlights the necessity to strengthen the function of the global surveillance network for H5N8 virus and to accelerate the pace of vaccine development to confront the current challenges posed by H5N8 virus of subclade 2.3.4.4. IMPORTANCE H5N8, a highly pathogenic avian influenza, not only has an impact on public health, but also has a huge negative impact on animal health, food safety, safety, and even on the local and international economy. The migratory wild birds play a vital role in the intercontinental transmission of H5N8 virus. It is urgent that we should strengthen the function of the global surveillance network for H5N8 virus and accelerate the pace of vaccine development to confront the current challenges posed by H5N8 virus of subclade 2.3.4.4.

A Single Vaccination of Chimeric Bivalent Virus-Like Particle Vaccine Confers Protection Against H9N2 and H3N2 Avian Influenza in Commercial Broilers and Allows a Strategy of Differentiating Infected from Vaccinated Animals.

H9N2 and H3N2 are the two most important subtypes of low pathogenic avian influenza viruses (LPAIV) because of their ongoing threat to the global poultry industry and public health. Although commercially available inactivated H9N2 vaccines are widely used in the affected countries, endemic H9N2 avian influenza remains uncontrolled. In addition, there is no available avian H3N2 vaccine. Influenza virus-like particles (VLPs) are one of the most promising vaccine alternatives to traditional egg-based vaccines. In this study, to increase the immunogenic content of VLPs to reduce production costs, we developed chimeric bivalent VLPs (cbVLPs) co-displaying hemagglutinin (HA) and neuraminidase (NA) of H9N2 and H3N2 viruses with the Gag protein of bovine immunodeficiency virus (BIV) as the inner core using the Bac-to-Bac baculovirus expression system. The results showed that a single immunization of chickens with 40µg/0.3mL cbVLPs elicited an effective immune response and provided complete protection against H9N2 and H3N2 viruses. More importantly, cbVLPs with accompanying serological assays can successfully accomplish the strategy of differentiating infected animals from vaccinated animals (DIVA), making virus surveillance easier. Therefore, this cbVLP vaccine candidate would be a promising alternative to conventional vaccines, showing great potential for commercial development.

Activation of Dopamine 4 Receptor Subtype Enhances Gamma Oscillations in Hippocampal Slices of Aged Mice.

Aim: Neural network oscillation at gamma frequency band (γ oscillation, 30-80 Hz) is synchronized synaptic potentials important for higher brain processes and altered in normal aging. Recent studies indicate that activation of dopamine 4 receptor (DR4) enhanced hippocampal γ oscillation of young mice and fully recovered the impaired hippocampal synaptic plasticity of aged mice, we determined whether this receptor is involved in aging-related modulation of hippocampal γ oscillation. Methods: We recorded γ oscillations in the hippocampal CA3 region from young and aged C57bl6 mice and investigated the effects of dopamine and the selective dopamine receptor (DR) agonists on γ oscillation. Results: We first found that γ oscillation power (γ power) was reduced in aged mice compared to young mice, which was restored by exogenous application of dopamine (DA). Second, the selective agonists for different D1- and D2-type dopamine receptors increased γ power in young mice but had little or small effect in aged mice. Third, the D4 receptor (D4R) agonist PD168077 caused a large increase of γ power in aged mice but a small increase in young mice, and its effect is blocked by the highly specific D4R antagonist L-745,870 or largely reduced by a NMDAR antagonist. Fourth, D3R agonist had no effect on γ power of either young or aged mice. Conclusion: This study reveals DR subtype-mediated hippocampal γ oscillations is aging-related and DR4 activation restores the impaired γ oscillations in aged brain, and suggests that D4R is the potential target for the improvement of cognitive deficits related to the aging and aging-related diseases.

Impaired central set point of thyroid homeostasis during quetiapine treatment in the acute phase of schizophrenia.

AIM: To evaluate the impact of quetiapine treatment on central set point of thyroid homeostasis in patients with acute phase schizophrenia. METHODS: During Jan. 2016 to Dec. 2018, we conducted a retrospective cohort study in "the Second Affiliated Hospital of Xinxiang Medical University". All patients admitted for treatment of schizophrenia being euthyroid at admission and reevaluated for thyroid function during hospitalization were recruited and followed until discharge. Patients treated with mood stabilizers during hospitalization were excluded. Quetiapine use was the exposure measure. The primary outcomes were the parameters of central set point of thyroid homeostasis measured by "thyroid-stimulating hormone (TSH) index" and "thyroid feedback quantile-based index (TFQI)". Multiple regression models were used to estimate the association between quetiapine exposure and outcomes. RESULTS: A total of 1302 patients were enrolled in this study. Quetiapine exposure was associated with a more significant decline in the TSH index and TFQI, and the adjusted ß and 95% confidence interval (CI) were -0.12 (-0.22, -0.01) and -0.10 (-0.15, -0.05), respectively. A dose-response association between quetiapine exposure and decline in TSH index and TFQI was observed (P < 0.05). Sensitivity analyses restricting to patients under mono-atypical antipsychotic therapy, or selecting patients in the non-quetiapine group matched to quetiapine group yielded similar results. CONCLUSION: Quetiapine was associated with TSH index and TFQI reduction in a dose-response pattern, suggesting that impaired central set point may be involved in the mechanism by which quetiapine affects hypothalamus-pituitary-thyroid axis in acute phase schizophrenia patients.

Effects of quetiapine on behavioral changes and expression of myelin proteins in a chronic alcohol dependence rat model.

BACKGROUND: As an atypical antipsychotic drug, quetiapine had been approved for bipolar disorder and for adjunctive therapy in major depressive disorder and schizophrenia. Recently quetiapine has been suggested to be a promising pharmacotherapy for alcohol dependence. This study was performed to determine the effects of quetiapine in rats chronically exposed to ethanol. METHODS: Rats were exposed to ethanol solution (10 %; v/v) for 6 weeks. Saline or one of three doses of quetiapine (10, 20 or 40 mg/kg/day) was given by oral gavage while ethanol exposure for the next 14 weeks. Performance of learning and memory and withdrawal signs were evaluated. Then immunohistochemistry, western blot, quantitative real-time-PCR and transmission electron microscopy were performed to determine the effects of quetiapine on alterations of brain white matter markers (myelin basic protein, MBP; proteolipid protein, PLP) and morphology caused by chronic ethanol exposure. RESULTS: Quetiapine treatment significantly alleviated withdrawal signs in the ethanol exposed rats. Chronic ethanol exposure reduced Y-type electric maze scores and the protein/mRNA expression levels of MBP and PLP in the prefrontal cortex and hippocampus, and these effects were reversed by quetiapine treatment. Similar ultrastructure morphological changes were observed. CONCLUSIONS: Chronic quetiapine treatment alleviated the damage induced by chronic ethanol exposure with regard to learning and memory ability and to brain white matter. Thus, quetiapine appears to be a potentially promising pharmacotherapy for the treatment of alcohol use disorder.

Enriched environment combined with fluoxetine ameliorates depression-like behaviors and hippocampal SYP expression in a rat CUS model.

Effects of enriched environment (EE) combined with fluoxetine in a chronic unpredictable stress (CUS) rat model were examined in our study. Thirty male Sprague-Dawley rats were randomly divided into control group, CUS group, CUS+EE group, CUS+fluoxetine group, and CUS+EE+fluoxetine group (n=six per group). Rats in the CUS group were bred under conditions of CUS and separation for 6 weeks; Control group animals were bred in group cages (three rats per cage) under standard laboratory conditions for 6 weeks; Rats in CUS+EE group, CUS+fluoxetine group, and CUS+EE+fluoxetine groups were bred under the conditions of CUS and separation for 6 weeks and had an intervention of EE, an oral gavage of fluoxetine, and an intervention of EE+oral gavage of fluoxetine, respectively, every day for the final 3 weeks. Every rat underwent a behavioral assessment at the beginning of the 1st week, at the end of the 3rd week and at the end of the 6th week. Behavioral assessments included sucrose water consumption, weight measurement, and an open field test (measuring horizontal moving distance, rearing behavior, and defecation). Finally, the level of synaptophysin expressed in the hippocampus was measured with immunohistochemistry. We found that EE, fluoxetine, and EE+fluoxetine all reversed the depression-like behaviors of CUS rats. The effect of EE+fluoxetine appeared to be superior to EE or fluoxetine alone; the expression level of synaptophysin in CA1, CA3, and DG of the hippocampus was decreased in CUS rats, however, exposure to EE, fluoxetine, and EE+fluoxetine all reversed this decrease.

[Effects of RhoA gene silencing by RNA interference on invasion of tongue carcinoma].

OBJECTIVE: To study the effects of RhoA down-regulation by RNA interference on the invasion of tongue carcinoma Tca8113 and SCC-4. METHODS: Determination of the human RhoA sequence as well as the design and constructionof a short specific small interfering RNAs (siRNA) were performed. The siRNA of RhoA gene was transfected into humantongue squamous cell carcinoma Tca8113 and SCC-4 cells line by Lipofectamine 2000. Quantitative real-time polymerasechain reaction was used to examine the mRNA expressionlevels of RhoA. Protein expressions of mRNA, galectin-3,and matrix metalloproteinase (MMP)-9 were evaluated byWestern blot. Transwell invasion assay was performed toassess the invasion ability of tongue carcinoma. RESULTS: RhoA expressions in Tca8113 and SCC-4 cells were reducedsignificantly after transfection of RhoA-siRNA. Protein levels f galectin-3 and MVP-9 were also down-regulated significantly. Invasion ability was inhibited as well. CONCLUSION: RhoA-siRNA can effectively inhibit RhoA expression in Tca8113 and SCC-4 cells. The invasion ability of tongue carcinoma cells decreased with down-regulation of the protein expressions of galectin-3 and MMP-9, indicating that RhoA-siRNA can inhibit invasion of tongue carcinoma. Results show that RhoA may play an important role in the processes of invasion and metastasis of tongue carcinoma.

Quetiapine mitigates the ethanol-induced oxidative stress in brain tissue, but not in the liver, of the rat.

Quetiapine, an atypical antipsychotic, has been employed to treat alcoholic patients with comorbid psychopathology. It was shown to scavenge hydroxyl radicals and to protect cultured cells from noxious effects of oxidative stress, a pathophysiological mechanism involved in the toxicity of alcohol. This study compared the redox status of the liver and the brain regions of prefrontal cortex, hippocampus, and cerebellum of rats treated with or without ethanol and quetiapine. Ethanol administration for 1 week induced oxidative stress in the liver and decreased the activity of glutathione peroxidase and total antioxidant capacity (TAC) there. Coadministration of quetiapine did not protect glutathione peroxidase and TAC in the liver against the noxious effect of ethanol, thus was unable to mitigate the ethanol-induced oxidative stress there. The ethanol-induced alteration in the redox status in the prefrontal cortex is mild, whereas the hippocampus and cerebellum are more susceptible to ethanol intoxication. For all the examined brain regions, coadministration of quetiapine exerted effective protection on the antioxidants catalase and total superoxide dismutase and on the TAC, thus completely blocking the ethanol-induced oxidative stress in these brain regions. These protective effects may explain the clinical observations that quetiapine reduced psychiatric symptoms intensity and maintained a good level of tolerability in chronic alcoholism with comorbid psychopathology.

Selective expression of Huntingtin-associated protein 1 in {beta}-cells of the rat pancreatic islets.

Huntingtin-associated protein-1 (HAP1) was initially identified as a binding partner of huntingtin, the Huntington's disease protein. Based on its preferred distribution among neurons and endocrine cells, HAP1 has been suggested to play roles in vesicular transportation in neurons and hormonal secretion of endocrine cells. Given that HAP1 is selectively expressed in the islets of rat pancreas, in this study, we analyzed the expression pattern of HAP1 in the islets. In rats injected intraperitoneally with streptozotocin, which can selectively destroy beta-cells of the pancreatic islets, the number of HAP1 immunoreactive cells was dramatically decreased and was accompanied by a parallel decrease in the number of insulin-immunoreactive cells. Immunofluorescent double staining of pancreas sections showed that, in rat islets, HAP1 is selectively expressed in the insulin-immunoreactive beta-cells but not in the glucagon-immunoreactive alpha-cells and somatostatin immunoreactive delta-cells. In isolated rat pancreatic islets, approximately 80% of cells expressed both HAP1 and insulin. Expression of HAP1 in the INS-1 rat insulinoma cell line was also demonstrated by immunofluorescent staining. Western blotting further revealed that HAP1 in both the isolated rat pancreatic islets and the INS-1 cells also has two isoforms, HAP1A and HAP1B, which are the same as those in the hypothalamus. These results demonstrated that HAP1 is selectively expressed in beta-cells of rat pancreatic islets, suggesting the involvement of HAP1 in the regulation of cellular trafficking and secretion of insulin.