Selegiline Modulates Lipid Metabolism by Activating AMPK Pathways of Epididymal White Adipose Tissues in HFD-Fed Obese Mice.

Obesity, as a major cause of many chronic diseases such as diabetes, cardiovascular disease, and cancer, is among the most serious health problems. Increased monoamine oxidase (MAO) activity has been observed in the adipose tissue of obese humans and animals. Although previous studies have already demonstrated the potential of MAO-B inhibitors as a treatment for this condition, the mechanism of their effect has been insufficiently elucidated. In this study, we investigated the anti-obesity effect of selegiline, a selective MAO-B inhibitor, using in vivo animal models. The effect was evaluated through an assessment of body energy homeostasis, glucose tolerance tests, and biochemical analysis. Pharmacological inhibition of MAO-B by selegiline was observed to reduce body weight and fat accumulation, and improved glucose metabolism without a corresponding change in food intake, in HFD-fed obese mice. We also observed that both the expression of adipogenenic markers, including C/EBPα and FABP4, and lipogenic markers such as pACC were significantly reduced in epididymal white adipose tissues (eWATs). Conversely, increased expression of lipolytic markers such as ATGL and pHSL and AMPK phosphorylation were noted. Treating obese mice with selegiline significantly increased expression levels of UCP1 and promoted eWAT browning, indicating increased energy expenditure. These results suggest that selegiline, by inhibiting MAO-B activity, is a potential anti-obesity treatment.

Regenerative Neurology and Regenerative Cardiology: Shared Hurdles and Achievements.

From the first success in cultivation of cells in vitro, it became clear that developing cell and/or tissue specific cultures would open a myriad of new opportunities for medical research. Expertise in various in vitro models has been developing over decades, so nowadays we benefit from highly specific in vitro systems imitating every organ of the human body. Moreover, obtaining sufficient number of standardized cells allows for cell transplantation approach with the goal of improving the regeneration of injured/disease affected tissue. However, different cell types bring different needs and place various types of hurdles on the path of regenerative neurology and regenerative cardiology. In this review, written by European experts gathered in Cost European action dedicated to neurology and cardiology-Bioneca, we present the experience acquired by working on two rather different organs: the brain and the heart. When taken into account that diseases of these two organs, mostly ischemic in their nature (stroke and heart infarction), bring by far the largest burden of the medical systems around Europe, it is not surprising that in vitro models of nervous and heart muscle tissue were in the focus of biomedical research in the last decades. In this review we describe and discuss hurdles which still impair further progress of regenerative neurology and cardiology and we detect those ones which are common to both fields and some, which are field-specific. With the goal to elucidate strategies which might be shared between regenerative neurology and cardiology we discuss methodological solutions which can help each of the fields to accelerate their development.

Development of a SFTSV DNA vaccine that confers complete protection against lethal infection in ferrets.

Although the incidence of severe fever with thrombocytopenia syndrome virus (SFTSV) infection has increased from its discovery with a mortality rate of 10-20%, no effective vaccines are currently available. Here we describe the development of a SFTSV DNA vaccine, its immunogenicity, and its protective efficacy. Vaccine candidates induce both a neutralizing antibody response and multifunctional SFTSV-specific T cell response in mice and ferrets. When the vaccine efficacy is investigated in aged-ferrets that recapitulate fatal clinical symptoms, vaccinated ferrets are completely protected from lethal SFTSV challenge without developing any clinical signs. A serum transfer study reveals that anti-envelope antibodies play an important role in protective immunity. Our results suggest that Gn/Gc may be the most effective antigens for inducing protective immunity and non-envelope-specific T cell responses also can contribute to protection against SFTSV infection. This study provides important insights into the development of an effective vaccine, as well as corresponding immune parameters, to control SFTSV infection.

Bacterial Outer Membrane Vesicles Provide Broad-Spectrum Protection against Influenza Virus Infection via Recruitment and Activation of Macrophages.

Influenza A virus (IAV) poses a constant worldwide threat to human health. Although conventional vaccines are available, their protective efficacy is type or strain specific, and their production is time-consuming. For the control of an influenza pandemic in particular, agents that are immediately effective against a wide range of virus variants should be developed. Although pretreatment of various Toll-like receptor (TLR) ligands have already been reported to be effective in the defense against subsequent IAV infection, the efficacy was limited to specific subtypes, and safety concerns were also raised. In this study, we investigated the protective effect of an attenuated bacterial outer membrane vesicle -harboring modified lipid A moiety of lipopolysaccharide (fmOMV) against IAV infection and the underlying mechanisms. Administration of fmOMV conferred significant protection against a lethal dose of pandemic H1N1, PR8, H5N2, and highly pathogenic H5N1 viruses; this broad antiviral activity was dependent on macrophages but independent of neutrophils. fmOMV induced recruitment and activation of macrophages and elicited type I IFNs. Intriguingly, fmOMV showed a more significant protective effect than other TLR ligands tested in previous reports, without exhibiting any adverse effect. These results show the potential of fmOMV as a prophylactic agent for the defense against influenza virus infection.

Promotion of tumor progression and cancer stemness by MUC15 in thyroid cancer via the GPCR/ERK and integrin-FAK signaling pathways.

Thyroid cancer is the fifth most common cancer diagnosed in women worldwide. Notwithstanding advancements in the prognosis and treatment of thyroid cancer, 10-20% of thyroid cancer patients develops chemotherapeutic resistance and experience relapse. According to previous reports and TCGA database, MUC15 (MUCIN 15) upregulation is highly correlated with thyroid cancer progression. However, the role of MUC15 in tumor progression and metastasis is unclear. This study aimed to investigate factors mediating cancer stemness in thyroid cancer. MUC15 plays an important role in sphere formation, as an evident from the expression of stemness markers including SOX2, KLF4, ALDH1A3, and IL6. Furthermore, ectopic expression of MUC15 activated extracellular signal-regulated kinase (ERK) signaling via G-protein-coupled receptor (GPCR)/cyclic AMP (cAMP) and integrin/focal adhesion kinase pathways. Interestingly, ectopic expression of MUC15 did not affect RAF/mitogen-activated protein kinase kinase (MEK)-mediated ERK activation. The present findings may provide novel insights into the development of diagnostic, prognostic, and therapeutic applications of MUC15 in thyroid cancer.

Mammalian adaptation of influenza A(H7N9) virus is limited by a narrow genetic bottleneck.

Human infection with avian influenza A(H7N9) virus is associated mainly with the exposure to infected poultry. The factors that allow interspecies transmission but limit human-to-human transmission are unknown. Here we show that A/Anhui/1/2013(H7N9) influenza virus infection of chickens (natural hosts) is asymptomatic and that it generates a high genetic diversity. In contrast, diversity is tightly restricted in infected ferrets, limiting further adaptation to a fully transmissible form. Airborne transmission in ferrets is accompanied by the mutations in PB1, NP and NA genes that reduce viral polymerase and neuraminidase activity. Therefore, while A(H7N9) virus can infect mammals, further adaptation appears to incur a fitness cost. Our results reveal that a tight genetic bottleneck during avian-to-mammalian transmission is a limiting factor in A(H7N9) influenza virus adaptation to mammals. This previously unrecognized biological mechanism limiting species jumps provides a measure of adaptive potential and may serve as a risk assessment tool for pandemic preparedness.

Immunomodulaton and attenuation of lethal influenza A virus infection by oral administration with KIOM-C.

Herbal medicine is used to treat many conditions such as asthma, eczema, premenstrual syndrome, rheumatoid arthritis, migraine, headaches, menopausal symptoms, chronic fatigue, irritable bowel syndrome, cancer, and viral infections such as influenza. In this study, we investigated the antiviral effect of KIOM-C for the treatment of influenza A virus infection. Our results show that oral administration of KIOM-C conferred a survival benefit to mice infected with the 2009 pandemic H1N1 [A(H1N1)pdm09] virus, and resulted in a 10- to 100-fold attenuation of viral replication in ferrets in a dose-dependent manner. Additionally, oral administration of KIOM-C increased the production of antiviral cytokines, including IFN-γ and TNF-α, and decreased levels of pro-inflammatory cytokines (IL-6) and chemokines (KC, MCP-1) in the Bronchoalveolar lavage fluid (BALF) of A(H1N1)pdm-infected mice. These results indicate that KIOM-C can promote clearance of influenza virus in the respiratory tracts of mice and ferrets by modulating cytokine production in hosts. Taken together, our results suggest that KIOM-C is a potential therapeutic compound mixture for the treatment of influenza virus infection in humans.

Early regulation of viral infection reduces inflammation and rescues mx-positive mice from lethal avian influenza infection.

Differing sensitivity of influenza A viruses to antiviral effects of the Myxovirus resistance (Mx) protein implies varying global gene expression profiles in the host. The role of Mx protein during lethal avian influenza (AI) virus infection was examined using Mx1-deficient C57BL/6 (B6-Mx1(-/-)) and congenic Mx1-expressing (B6-Mx1(+/+)) mice infected with a virulent, mouse-adapted avian H5N2 Ab/Korea/ma81/07 (Av/ma81) virus. After infection, B6-Mx1(+/+) mice were completely protected from lethal AI-induced mortality, and exhibited attenuated clinical disease and reduced viral titers and pathology in the lungs, compared with B6-Mx1(-/-) mice. Transcriptional profiling of lung tissues revealed that most of the genes up-regulated after infection are involved in activation of the immune response and host defense. Notably, more abundant and sustained expression of cytokine/chemokine genes was observed up to 3 dpi in B6-Mx1(-/-) mice, and this was associated with excessive induction of cytokines and chemokines. Consequently, massive infiltration of macrophages/monocytes and granulocytes into lung resulted in severe viral pneumonia and potentially contributed to decreased survival of B6-Mx1(-/-) mice. Taken together, our data show that dysregulated gene transcriptional activity corresponded to persistent induction of cytokine/chemokines and recruitment of cytokine-producing cells that promote inflammation in B6-Mx1(-/-) mouse lungs. Thus, we provide additional evidence of the interplay of genetic, molecular, and cellular correlates governed by the Mx1 protein that critically determine disease outcome during lethal AI virus infection.

Interferon regulatory factor 7 regulates glioma stem cells via interleukin-6 and Notch signalling.

Inflammatory microenvironment signalling plays a crucial role in tumour progression (i.e. cancer cell proliferation, survival, angiogenesis and metastasis) in many types of human malignancies. However, the role of inflammation in brain tumour pathology remains poorly understood. Here, we report that interferon regulatory factor 7 is a crucial regulator of brain tumour progression and heterogeneity. Ectopic expression of interferon regulatory factor 7 in glioma cells promotes tumorigenicity, angiogenesis, microglia recruitment and cancer stemness in vivo and in vitro through induction of interleukin 6, C-X-C motif chemokine 1 and C-C motif chemokine 2. In particular, interferon regulatory factor 7-driven interleukin 6 plays a pivotal role in maintaining glioma stem cell properties via Janus kinase/signal transducer and activator of transcription-mediated activation of Jagged-Notch signalling in glioma cells and glioma stem cells derived from glioma patients. Accordingly, the short hairpin RNA-mediated depletion of interferon regulatory factor 7 in glioma stem cells markedly suppressed interleukin 6-Janus kinase/signal transducer and activator of transcription-mediated Jagged-Notch-signalling pathway, leading to decreases in glioma stem cell marker expression, tumoursphere-forming ability, and tumorigenicity. Furthermore, in a mouse model of wound healing, depletion of interferon regulatory factor 7 suppressed tumour progression and decreased cellular heterogeneity. Finally, interferon regulatory factor 7 was overexpressed in patients with high-grade gliomas, suggesting its potential as an independent prognostic marker for glioma progression. Taken together, our findings indicate that interferon regulatory factor 7-mediated inflammatory signalling acts as a major driver of brain tumour progression and cellular heterogeneity via induction of glioma stem cell genesis and angiogenesis.

Prevalence and genetic characterization of respiratory syncytial virus (RSV) in hospitalized children in Korea.

Human respiratory syncytial virus (HRSV) is the most common respiratory pathogen among infants and young children. To investigate the prevalence and genetic characteristics of HRSVs circulating in South Korea, we analyzed medical records of patients and performed molecular analysis of the G-protein gene of viruses detected from nasopharyngeal aspirates (NPA) of admitted patients at the Pediatrics Department of Chungbuk National University Hospital from April 2008 to April 2010. Epidemiological data revealed that the prevalence of HRSV infection was high during both winter seasons (October 2008 to February 2009 and November 2009 to February 2010). Of the 297 positive NPA specimens from infants or children tested, 67% were identified as HRSV-A while 33% were HRSV-B. The HRSV subgroup B was the most dominant in December 2008, but its dominance was dramatically replaced by HRSV subgroup A strains by February 2009. Phylogenetic analysis of the G protein sequences of HRSVs revealed novel genotypes within the HRSV-A (genotype CB-A) and B (genotypes BA11 and CB-B) subgroups in South Korea in addition to other strains identified in other countries. Molecular analysis also revealed genetic variability at the C-terminal end of the G proteins of the two HRSV subgroups, suggesting selection pressure in this region, which may potentially impact immune recognition. This is the first report of these HRSV variants in South Korea, indicating active genetic evolution of HRSV strains. Therefore, this study provides information on the molecular epidemiology of current HRSVs in the country and presents data for comparative analysis with other HRSV strains circulating worldwide.

Role of the p21-activated kinases (PAKs) in influenza A virus replication.

Influenza A virus infection stimulates a wide range of virus-supportive or antiviral mechanisms in host cells. p21-Activated kinase 1 (PAK1) is a serine/threonine kinase that regulates a number of fundamental cellular processes and has been implicated in the modulation of virus replication. Here, we investigated the role of PAK1 activation during influenza A virus infection and found that virus propagation corresponded to stimulated PAK1 phosphorylation. Moreover, transfection of the active form of PAK1 (PAK1-T423E) in A549 cells induced higher viral titers (∼10-fold differences) compared to that in the control vector or inactive PAK1 (PAK1-K299R)-transfected cells. PAK1-specific siRNA knockdown also resulted in 10-100-fold reductions in virus yields compared to that in the control siRNA-treatment (p<0.05). We further showed that treatment with PAK18, a PAK1 peptide inhibitor, resulted in marked suppression of both ERK 1/2 phosphorylation and infectious virus production, which was comparable to that by U0126, a specific MEK/ERK inhibitor. These results provide evidence for the importance of PAK1 activation during influenza virus infection and its association with ERK in regulating virus replication. The present study also implicates PAK1 as a potential therapeutic target for managing influenza virus infections.

Mucosal immunity induced by adenovirus-based H5N1 HPAI vaccine confers protection against a lethal H5N2 avian influenza virus challenge.

Development of effective vaccines against highly pathogenic avian influenza (HPAI) H5N1 viruses is a global public health priority. Considering the difficulty in predicting HPAI H5N1 pandemic strains, one strategy used in their design includes the development of formulations with the capacity of eliciting broad cross-protective immunity against multiple viral antigens. To this end we constructed a replication-defective recombinant adenovirus-based avian influenza virus vaccine (rAdv-AI) expressing the codon-optimized M2eX-HA-hCD40L and the M1-M2 fusion genes from HPAI H5N1 human isolate. Although there were no significant differences in the systemic immune responses observed between the intramuscular prime-intramuscular boost regimen (IM/IM) and the intranasal prime-intramuscular boost regimen (IN/IM), IN/IM induced more potent CD8(+) T cell and antibody responses at mucosal sites than the IM/IM vaccination, resulting in more effective protection against lethal H5N2 avian influenza (AI) virus challenge. These findings suggest that the strategies used to induce multi-antigen-targeted mucosal immunity, such as IN/IM delivery of rAdv-AI, may be a promising approach for developing broad protective vaccines that may be more effective against the new HPAI pandemic strains.