Porcine reproductive and respiratory syndrome virus 2 hijacks CMA-mediated lipolysis through upregulation of small GTPase RAB18.

RAB GTPases (RABs) control intracellular membrane trafficking with high precision. In the present study, we carried out a short hairpin RNA (shRNA) screen focused on a library of 62 RABs during infection with porcine reproductive and respiratory syndrome virus 2 (PRRSV-2), a member of the family Arteriviridae. We found that 13 RABs negatively affect the yield of PRRSV-2 progeny virus, whereas 29 RABs have a positive impact on the yield of PRRSV-2 progeny virus. Further analysis revealed that PRRSV-2 infection transcriptionally regulated RAB18 through RIG-I/MAVS-mediated canonical NF-κB activation. Disrupting RAB18 expression led to the accumulation of lipid droplets (LDs), impaired LDs catabolism, and flawed viral replication and assembly. We also discovered that PRRSV-2 co-opts chaperone-mediated autophagy (CMA) for lipolysis via RAB18, as indicated by the enhanced associations between RAB18 and perlipin 2 (PLIN2), CMA-specific lysosomal associated membrane protein 2A (LAMP2A), and heat shock protein family A (Hsp70) member 8 (HSPA8/HSC70) during PRRSV-2 infection. Knockdown of HSPA8 and LAMP2A impacted on the yield of PRRSV-2 progeny virus, implying that the virus utilizes RAB18 to promote CMA-mediated lipolysis. Importantly, we determined that the C-terminal domain (CTD) of HSPA8 could bind to the switch II domain of RAB18, and the CTD of PLIN2 was capable of associating with HSPA8, suggesting that HSPA8 facilitates the interaction between RAB18 and PLIN2 in the CMA process. In summary, our findings elucidate how PRRSV-2 hijacks CMA-mediated lipid metabolism through innate immune activation to enhance the yield of progeny virus, offering novel insights for the development of anti-PRRSV-2 treatments.

Two Novel Diterpenoid Alkaloids from Aconitum Pendulum.

Two previously uncharacterized compounds, an aconitine-type C19-diterpenoid alkaloid (1) and a napelline-type diterpenoid alkaloid C20-diterpenoid alkaloid (2), as well as ten known compounds (3-12), were isolated from Aconitum pendulum. Their structures were elucidated based on spectroscopic data, including 1D and 2D NMR, IR, HR-ESI-MS, and single-crystal X-ray diffraction analysis. The anti-insecticidal activities of these compounds were evaluated by contact toxicity tests against two-spotted spider mites, and compounds 1, 2, and 9 showed moderate contact toxicity, with LC50 values of 0.86±0.09, 0.95±0.23, and 0.89±0.19 mg/mL, respectively. This study highlights the potential use of diterpenoid alkaloids as natural plant-derived pesticides for the management of plant pests.

Inhibition of PARP1 Dampens Pseudorabies Virus Infection through DNA Damage-Induced Antiviral Innate Immunity.

Pseudorabies virus (PRV) is the causative pathogen of Aujeszky's disease in pigs. Although vaccination is currently applied to prevent the morbidity of PRV infection, new applications are urgently needed to control this infectious disease. Poly(ADP-ribose) polymerase 1 (PARP1) functions in DNA damage repair. We report here that pharmacological and genetic inhibition of PARP1 significantly influenced PRV replication. Moreover, we demonstrate that inhibition of PARP1 induced DNA damage response and antiviral innate immunity. Mechanistically, PARP1 inhibition-induced DNA damage response resulted in the release of double-stranded DNA (dsDNA) into the cytosol, where dsDNA interacted with cyclic GMP-AMP (cGAMP) synthase (cGAS). cGAS subsequently catalyzed cGAMP production to activate the STING/TBK1/IRF3 innate immune signaling pathway. Furthermore, challenge of mice with PARP1 inhibitor stimulated antiviral innate immunity and protected mice from PRV infection in vivo. Our results demonstrate that PARP1 inhibitors may be used as a new strategy to prevent Aujeszky's disease in pigs. IMPORTANCE Aujeszky's disease is a notifiable infectious disease of pigs and causes economic losses worldwide in the pig industry. The causative pathogen is PRV, which is a member of the subfamily Alphaherpesvirinae of the family Herpesviridae. PRV has a wide range of hosts, such as ruminants, carnivores, and rodents. More seriously, recent reports suggest that PRV can cause human endophthalmitis and encephalitis, which indicates that PRV may be a potential zoonotic pathogen. Although vaccination is currently the major strategy used to control the disease, new applications are also urgently needed for the pig industry and public health. We report here that inhibition of PARP1 induces DNA damage-induced antiviral innate immunity through the cGAS-STING signaling pathway. Therefore, PARP1 is a therapeutic target for PRV infection as well as alphaherpesvirus infection.

BRD4 inhibition exerts anti-viral activity through DNA damage-dependent innate immune responses.

Chromatin dynamics regulated by epigenetic modification is crucial in genome stability and gene expression. Various epigenetic mechanisms have been identified in the pathogenesis of human diseases. Here, we examined the effects of ten epigenetic agents on pseudorabies virus (PRV) infection by using GFP-reporter assays. Inhibitors of bromodomain protein 4 (BRD4), which receives much more attention in cancer than viral infection, was found to exhibit substantial anti-viral activity against PRV as well as a range of DNA and RNA viruses. We further demonstrated that BRD4 inhibition boosted a robust innate immune response. BRD4 inhibition also de-compacted chromatin structure and induced the DNA damage response, thereby triggering the activation of cGAS-mediated innate immunity and increasing host resistance to viral infection both in vitro and in vivo. Mechanistically, the inhibitory effect of BRD4 inhibition on viral infection was mainly attributed to the attenuation of viral attachment. Our findings reveal a unique mechanism through which BRD4 inhibition restrains viral infection and points to its potent therapeutic value for viral infectious diseases.

Complex Flavanones from Cryptocarya metcalfiana and Structural Revision of Oboflavanone A.

Nine new complex flavanones, cryptometcones A-I (1-9), along with four known analogues, were isolated from Cryptocarya metcalfiana. The structures of 1-9 including their absolute configurations were elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. In addition, the structure of oboflavanone A was revised, while the absolute configurations of oboflavanone B, cryptoflavanone C, and cryptoflavanone D were determined, according to their spectroscopic data. Compounds 3-5, 8, and 9 exhibited cytotoxicity against the HCT-116 cancer cell line.

Homoharringtonine inhibits melanoma cells proliferation in vitro and vivo by inducing DNA damage, apoptosis, and G2/M cell cycle arrest.

Homoharringtonine (HHT), an approved anti-leukemic alkaloid, has been reported effectively in many types of tumor cells. However, its effect on melanoma cells has not been investigated. And the anti-melanoma mechanism of HHT is still unknown. In this study, we detected the effects of HHT on two melanoma cell lines (A375 and B16F10) and on the A375 xenograft mouse model. HHT significantly inhibited the proliferation of melanoma cells as investigated by the CCK8 method, cell cloning assay, and EdU experiment. HHT induced A375 and B16F10 cells DNA damage, apoptosis, and G2/M cell cycle arrest as proved by TdT-mediated dUTP Nick-End Labeling (TUNEL) and flow cytometry assay. Additionally, the loss of mitochondrial membrane potential in HHT-treated cells were visualized by JC-1 fluorescent staining. For the molecule mechanism study, western blotting results indicated the protein expression levels of ATM, P53, p-P53, p-CHK2, γ-H2AX, PARP, cleaved-PARP, cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, Aurka, p-Aurka, Plk1, p-Plk1, Cdc25c, CDK1, cyclin B1, and Myt1 were regulated by HHT. And the relative mRNA expression level of Aurka, Plk1, Cdc25c, CDK1, cyclin B1, and Myt1 were ascertained by q-PCR assay. The results in vivo experiment showed that HHT can slow down the growth rate of tumors. At the same time, the protein expression levels in vivo were consistent with that in vitro. Collectively, our study provided evidence that HHT could be considered an effective anti-melanoma agent by inducing DNA damage, apoptosis, and cell cycle arrest.

Evodiamine inhibits vasculogenic mimicry in HCT116 cells by suppressing hypoxia-inducible factor 1-alpha-mediated angiogenesis.

Evodiamine (Evo), a quinazoline alkaloid and one of the most typical polycyclic heterocycles, is mainly isolated from Evodia rugulosa. Vasculogenic mimicry (VM) is a newly identified way of angiogenesis during tumor neovascularization, which is prevalent in a variety of highly invasive tumors. The purpose of this study was to investigate the effect and mechanism of Evo on VM in human colorectal cancer (CRC) cells. The number of VM structures was calculated by the three-dimensional culture of human CRC cells. Wound-healing was used to detect the migration of HCT116 cells. Gene expression was detected by reverse transcription-quantitative PCR assay. CD31/PAS staining was used to identify VM. Western blotting and immunofluorescence were used to detect protein levels. The results showed that Evo inhibited the migration of HCT116 cells, as well as the formation of VM. Furthermore, Evo reduced the expression of hypoxia-inducible factor 1-alpha (HIF-1α), VE-cadherin, VEGF, MMP2, and MMP9. In a model of subcutaneous xenotransplantation, Evo also inhibited tumor growth and VM formation. Our study demonstrates that Evo could inhibit VM in CRC cells HCT116 and reduce the expression of HIF-1α, VE-cadherin, VEGF, MMP2, and MMP9.

Porcine Reproductive and Respiratory Syndrome Virus Activates Lipophagy To Facilitate Viral Replication through Downregulation of NDRG1 Expression.

Autophagy maintains cellular homeostasis by degrading organelles, proteins, and lipids in lysosomes. Autophagy is involved in the innate and adaptive immune responses to a variety of pathogens. Some viruses can hijack host autophagy to enhance their replication. However, the role of autophagy in porcine reproductive and respiratory syndrome virus (PRRSV) infection is unclear. Here, we show that N-Myc downstream-regulated gene 1 (NDRG1) deficiency induced autophagy, which facilitated PRRSV replication by regulating lipid metabolism. NDRG1 mRNA is expressed ubiquitously in most porcine tissues and most strongly in white adipose tissue. PRRSV infection downregulated the expression of NDRG1 mRNA and protein, while NDRG1 deficiency contributed to PRRSV RNA replication and progeny virus assembly. NDRG1 deficiency reduced the number of intracellular lipid droplets (LDs), but the expression levels of key genes in lipogenesis and lipolysis were not altered. Our results also show that NDRG1 deficiency promoted autophagy and increased the subsequent yields of hydrolyzed free fatty acids (FFAs). The reduced LD numbers, increased FFA levels, and enhanced PRRSV replication were abrogated in the presence of an autophagy inhibitor. Overall, our findings suggest that NDRG1 plays a negative role in PRRSV replication by suppressing autophagy and LD degradation.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV), an enveloped single-positive-stranded RNA virus, causes acute respiratory distress in piglets and reproductive failure in sows. It has led to tremendous economic losses in the swine industry worldwide since it was first documented in the late 1980s. Vaccination is currently the major strategy used to control the disease. However, conventional vaccines and other strategies do not provide satisfactory or sustainable prevention. Therefore, safe and effective strategies to control PRRSV are urgently required. The significance of our research is that we demonstrate a previously unreported relationship between PRRSV, NDRG1, and lipophagy in the context of viral infection. Furthermore, our data point to a new role for NDRG1 in autophagy and lipid metabolism. Thus, NDRG1 and lipophagy will have significant implications for understanding PRRSV pathogenesis for developing new therapeutics.

Cholesterol 25-hydroxylase acts as a host restriction factor on pseudorabies virus replication.

Cholesterol 25-hydroxylase (CH25H) catalyses the production of 25-hydroxycholesterol (25HC) from cholesterol by adding a second hydroxyl group at position 25. The aim of this study was to examine the antiviral effect of CH25H on pseudorabies virus (PRV), a swine pathogen that can cause devastating disease and economic losses worldwide. The results showed that porcine ch25h was induced by either interferon or PRV infection. PRV infection of porcine alveolar macrophages (3D4/21 cells) was attenuated by CH25H overexpression and enhanced by silencing of CH25H. Furthermore, treatment of 3D4/21 cells with 25HC inhibited the growth of PRV in vitro, suggesting that CH25H may restrict PRV replication by 25HC production. We further identified that the anti-PRV role of CH25H and 25HC was subject to their inhibitory effect on PRV attachment and entry. Collectively, these findings demonstrate that CH25H is an intrinsic host restriction factor in PRV infection of porcine alveolar macrophages.

Electrocardiogram score for the selection of reperfusion strategy in early latecomers with ST-segment elevation myocardial infarction.

OBJECTIVE: The clinical benefit of percutaneous coronary intervention (PCI) is controversial in ST-segment elevation myocardial infarction (STEMI) patients presenting 12-72 hours after symptom onset. Several studies suggested this conflicting result was associated with myocardial area at risk (MaR) of enrolled patients. MaR could be estimated by the electrocardiogram (ECG) score. Our objective was to evaluate the benefits of PCI in STEMI latecomers with different MaR. METHODS: We constructed a prospective cohort involving 436 patients presenting 12-72 hours after STEMI onset and who met an inclusion criteria. 218 underwent PCI and 218 received the optimal medical therapy (OMT) alone. Individual MaR was quantified by the combined Aldrich ST and Selvester QRS score. The primary endpoint was a composite of cardiovascular death, reinfarction or revascularization within two years. RESULTS: The 2-year cumulative primary endpoint rate was respectively 9.2% in PCI group and 5.3% in OMT group when MaR<35% (adjusted hazard ratio for PCI vs. OMT, 1.855; 95% confidence interval [CI], 0.617-5.575; P=0.271), and was 12.8% in PCI group and 23.1% in OMT group when MaR ≥35% (adjusted hazard ratio for PCI vs. OMT, 0.448; 95% CI, 0.228-0.884; P=0.021). CONCLUSION: The benefit of PCI for the STEMI latecomers was associated with the MaR. PCI, compared with OMT, could significantly reduce the 2-year primary outcomes in patients with MaR≥35%, but not in ones with MaR<35%.

The anti-hepatocellular carcinoma effects of polysaccharides from Ganoderma lucidum by regulating macrophage polarization via the MAPK/NF-κB signaling pathway.

The response of macrophages to environmental signals demonstrates its heterogeneity and plasticity. After different forms of polarized activation, macrophages reach the M1 or M2 activation state according to their respective environment. Ganoderma lucidum polysaccharide (GLPS) is a major bioactive component of Ganoderma lucidum, a well-known medicinal mushroom. Although the immunomodulatory and anti-tumor effects of GLPS have been proven, GLPS's effect on inhibiting hepatocellular carcinoma (HCC) by regulating macrophage polarization is little known. Our data showed that GLPS notably inhibited the growth of a Hepa1-6 allograft. The expression of M1 marker CD86 was higher in the tumor tissue of the GLPS treatment group than in the control group in vivo. In vitro, the phagocytic activity and NO production of macrophages were increased by GLPS treatment. Moreover, it was discovered that GLPS was able to increase the expression of the M1 phenotype marker CD86, iNOS, and pro-inflammatory cytokines comprising IL-12a, IL-23a, IL-27 and TNF-α, but inhibited macrophage polarization towards the M2 phenotype by decreasing the expression of CD206, Arg-1, and inflammation-related cytokines comprising IL-6 and IL-10. The data suggest that GLPS may regulate macrophage polarization. Mechanistically, GLPS increased the phosphorylation of MEK and ERK. In addition, the phosphorylation of IκBα and P65 was increased by GLPS treatment. These data showed that GLPS can regulate the MAPK/NF-κB signaling pathway responsible for M1 polarization. In a nutshell, our research puts forward a new application of GLPS in anti-HCC treatment by regulating macrophage polarization through activating MAPK/NF-κB signaling.

[Preliminary study of estrogen effects on calcium free smooth muscle cells at the endometrial-myometrial interface in uteri with adenomyosis].

OBJECTIVE: To investigate the effect and mechanism of estrodial (E(2)) on intracellular free calcium in the endometrial-myometrial interface (EMI) smooth muscle cells from uteri with adenomyosis. METHODS: From March 2011 to October 2011, 16 uterus specimens were collected from patients with adenomyosis undergoing hysterectomy in Beijing Obstetrics and Gynecology Hospital, which included 9 proliferative endometrium and 7 secretory endometrium. EMI smooth muscle cells from the uterus were cultured and loaded with calcium ion (Ca(2+)) fluorescent probe fluo-4/AM. The labeled cells were stimulated with the various concentration of E(2)(1×10(2), 1×10(3), 1×10(4), 1×10(5) pmol/L, respectively), then the changes of intracellular Ca(2+) fluorescence intensity were measured by laser scanning microscopy. The most suitable concentration of E(2) was selected, and the reaction difference between the EMI smooth muscle cells of two menstrual phases were also investigated; The changes of intracellular Ca(2+) fluorescence intensity were detected proliferative and secretory smooth muscle cells in E(2) conjugated to bovine serum albumin (17ß-E(2)-BSA) group, cycloheximide (CHX) group, fulvestrant (ICI182780) group and pertussis toxin (PTX) group. RESULTS: (1) The cell viability of primary cultured EMI smooth muscle cells was well at 24 hours culture. (2) 1×10(2) - 1×10(5) pmol/L E(2) can rapidly increase the intracellular Ca(2+) fluorescence intensity within 1 min (P < 0.01);The increased amplitudes caused by 1×10(4) pmol/L and 1×10(5) pmol/L E(2) were the most significant, but there was no significant difference between them (P > 0.05). 1×10(4) pmol/L was the most suitable concentration. (3) With the 1×10(4) pmol/L E(2), the Ca(2+) fluorescence intensity changes showed no significant difference between the EMI smooth muscle cells from the proliferative phase and secretory phase uterus (P > 0.05). The Ca(2+) fluorescence intensity changes were 646 ± 32 in 17ß-E(2)-BSA group and 602 ± 31 in CHX group, when compared with 513 ± 26 and 617 ± 35 in respective control group, no significant difference was observed (P > 0.05). The increased amplitude of 188 ± 20 in the PTX group and 302 ± 11 in ICI182780 group exhibited significant difference with 632 ± 33 and 635 ± 24 in respective control group (P < 0.01). CONCLUSION: E(2) could increase the intracellular Ca(2+) of EMI through a membrane receptor dependent and nongenomic mechanism of action.

Prediction of Long-Term Survival Outcome by Lymph Node Ratio in Patients of Parotid Gland Cancer: A Retrospective study.

Background: Lymph node ratio (LNR) has been reported to reliably predict cancer-specific survival (CSS) in parotid gland cancer (PGC). Our study was designed to validate the significance of LNR in patients with PGC. Methods: Patients diagnosed with stage I-IV PGC were enrolled from Surveillance Epidemiology and End Results database (SEER, N = 3529), which is the training group, and Sun Yat-sen University Cancer Center database (SYSUCC, N = 99), the validation group. We used X-tile software to choose the optimal cutoff value of LNR; then, univariable and multivariable analyses were performed, assessing the association between LNR and CSS. Results: The optimal cutoff value of LNR was 0.32 by X-tile based on 3529 patients from SEER. Cox proportional hazard regression analysis revealed better CSS for patients with LNR ≤ 0.32 (adjusted hazard ratio [HR] 1.612, 95% confidence interval [95% CI] 1.286-2.019; p < 0.001) compared with patients with LNR > 0.32 in SEER. In the SYSUCC cohort, patients with LNR ≤ 0.32 also had better CSS over patients with LNR > 0.32 (p < 0.001). In N2 and N3 stage groups, patients with LNR ≤ 0.32 had superior CSS outcomes over those with the LNR > 0.32 group, but this benefit was absent in the N1 stage group. Conclusions: In conclusion, the lymph node ratio turned out to be an independent prognostic factor for cancer-specific survival of PGC in this study. This valuable information could help clinicians to evaluate the prognosis of PGC and suggest that adequate lymph node dissection is necessary.

Pseudorabies Virus Inhibits Expression of Liver X Receptors to Assist Viral Infection.

Pseudorabies virus (PRV) is a contagious herpesvirus that causes Aujeszky's disease and economic losses worldwide. Liver X receptors (LXRs) belong to the nuclear receptor superfamily and are critical for the control of lipid homeostasis. However, the role of LXR in PRV infection has not been fully established. In this study, we found that PRV infection downregulated the mRNA and protein levels of LXRα and LXRß in vitro and in vivo. Furthermore, we discovered that LXR activation suppressed PRV proliferation, while LXR inhibition promoted PRV proliferation. We demonstrated that LXR activation-mediated reduction of cellular cholesterol was critical for the dynamics of PRV entry-dependent clathrin-coated pits. Replenishment of cholesterol restored the dynamics of clathrin-coated pits and PRV entry under LXR activation conditions. Interestingly, T0901317, an LXR agonist, prevented PRV infection in mice. Our results support a model that PRV modulates LXR-regulated cholesterol metabolism to facilitate viral proliferation.

[Expression and significance of Survivin and Smac in ovarian mucinous tumors].

OBJECTIVE: To investigate the expressions and significances of Survivin and Smac in ovarian mucinous tumors. METHODS: A total of 55 paraffin-embedded specimens of primary ovarian mucinous tumors were collected. SABC was used to detect protein expression of Survivin and Smac genes. Immunoelectron microscopy using colloidal gold labeling was performed to determine the subcellular localization and patterns of Smac protein expression. RESULTS: (1) The cytoplasmic expression rates of survivin in benign, borderline and malignant ovarian mucinous tumors were 2/20, 12/15 and 20/20 respectively, which presents an improving trend.There were significant differences of survivin expression between benign vs. borderline lesions (P < 0.01), and benign vs. malignant tumors (P < 0.01). The nuclear expression rates of survivin in benign, borderline and malignant ovarian mucinous tumors were 1/20, 6/15 and 5/20, respectively, which presents a.declining trend.There was significant difference of survivin expression between benign vs. borderline tumors (P < 0.05). The positive expression rates of Smac among the three groups were 19/20, 9/15 and 3/20, respectively. There was significant difference among the three groups (P < 0.01 or < 0.05). There was a negative correlation between Survivin and Smac (r = -0.153, P < 0.01). (2) Colloidal gold labeling study demonstrated that mitochondrion intramembranous storage of Smac granules in the three groups were 24.1 ± 7.2, 11.1 ± 1.9 and 5.2 ± 1.7, respectively, and there were significant differences among the three groups (P < 0.01 or < 0.05). The extramemebranous Smac granules were 4.7 ± 3.0, 2.9 ± 1.0 and 1.7 ± 1.3, although without significant difference among the three groups (P > 0.05). CONCLUSIONS: With the malignant development of ovarian mucinous tumors, the expressions of Survivin are up-regulated, and the expressions of Smac are down-regulated. Smac proteins exist mainly in an inactive intramembranous storage form inside of mitochondria.

Phase II Study of Preoperative Intra-Arterial Epirubicin, Etoposide, and Oxaliplatin Combined with Oral S-1 Chemotherapy for the Treatment of Borrmann Type 4 Gastric Cancer.

PURPOSE: A phase II study was conducted to evaluate the safety and efficacy of preoperative, intra-arterial perfusion of epirubicin, etoposide, and oxaliplatin combined with oral chemotherapy S-1 (SEEOX) for the treatment of type 4 gastric cancer. MATERIALS AND METHODS: A single-center, single-arm phase II trial was conducted on 36 patients with histologically proven type 4 gastric cancer without distant peritoneal or organ metastasis. Patients received 3, 21-day courses of SEEOX preoperative chemotherapy. The primary endpoint was overall survival (OS) and the secondary outcomes assessed were chemotherapeutic response, radical resection rate, pathological regression, toxicities, postoperative morbidity, and mortality. RESULTS: All patients were at an advanced stage of cancer (stage III or IV) and completed the entire course of treatment. Based on changes in tumor volume and peritoneal metastasis, the objective response rate was 55.6% (20/36; 95% confidence interval [CI], 38.5%-72.6%) and the disease control rate was 69.4% (25/36; 95% CI, 53.6%-85.3%). The radical resection rate was 75% (27/36; 95% CI, 60.1%-89.9%) and the proportion of R0 resections was 66.7% (21/36; 95% CI, 50.5%-82.8%). The pathological response rate was 33.3%, of which 13.9% showed complete pathological regression. The median survival was 27.1 months (95% CI, 22.24-31.97 months), and the 2-year OS was 48.5% (95% CI, 30.86%-66.1%). CONCLUSIONS: Preoperative SEEOX is a safe and effective treatment for type 4 gastric cancer. Based on these preliminary data, a phase III study will be conducted to confirm the superiority of this regimen over standard treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02949258.

The Human-Specific STING Agonist G10 Activates Type I Interferon and the NLRP3 Inflammasome in Porcine Cells.

Pigs have anatomical and physiological characteristics comparable to those in humans and, therefore, are a favorable model for immune function research. Interferons (IFNs) and inflammasomes have essential roles in the innate immune system. Here, we report that G10, a human-specific agonist of stimulator of interferon genes (STING), activates both type I IFN and the canonical NLRP3 inflammasome in a STING-dependent manner in porcine cells. Without a priming signal, G10 alone transcriptionally stimulated Sp1-dependent p65 expression, thus triggering activation of the nuclear factor-κB (NF-κB) signaling pathway and thereby priming inflammasome activation. G10 was also found to induce potassium efflux- and NLRP3/ASC/Caspase-1-dependent secretion of IL-1ß and IL-18. Pharmacological and genetic inhibition of NLRP3 inflammasomes increased G10-induced type I IFN expression, thereby preventing virus infection, suggesting negative regulation of the NLRP3 inflammasome in the IFN response in the context of STING-mediated innate immune activation. Overall, our findings reveal a new mechanism through which G10 activates the NLRP3 inflammasome in porcine cells and provide new insights into STING-mediated innate immunity in pigs compared with humans.

An effective inactivant based on singlet oxygen-mediated lipid oxidation implicates a new paradigm for broad-spectrum antivirals.

Emerging viral pathogens cause substantial morbidity and pose a severe threat to health worldwide. However, a universal antiviral strategy for producing safe and immunogenic inactivated vaccines is lacking. Here, we report an antiviral strategy using the novel singlet oxygen (1O2)-generating agent LJ002 to inactivate enveloped viruses and provide effective protection against viral infection. Our results demonstrated that LJ002 efficiently generated 1O2 in solution and living cells. Nevertheless, LJ002 exhibited no signs of acute toxicity in vitro or in vivo. The 1O2 produced by LJ002 oxidized lipids in the viral envelope and consequently destroyed the viral membrane structure, thus inhibiting the viral and cell membrane fusion necessary for infection. Moreover, the 1O2-based inactivated pseudorabies virus (PRV) vaccine had no effect on the content of the viral surface proteins. Immunization of mice with LJ002-inactiviated PRV vaccine harboring comparable antigen induced more neutralizing antibody responses and efficient protection against PRV infection than conventional formalin-inactivated vaccine. Additionally, LJ002 inactivated a broad spectrum of enveloped viruses. Together, our results may provide a new paradigm of using broad-spectrum, highly effective inactivants functioning through 1O2-mediated lipid oxidation for developing antivirals that target the viral membrane fusion process.

Porcine IFITM1 is a host restriction factor that inhibits pseudorabies virus infection.

Interferon-inducible transmembrane proteins (IFITMs) restrict infection by several viruses, such as influenza A virus, West Nile virus and dengue virus. It has not been determined whether porcine IFITMs (pIFITMs) inhibit infection by pseudorabies virus (PRV), an enveloped, double-stranded DNA virus, which is the etiological agent of Aujeszky's disease in pigs. Here, we report that PRV infection elicited pIFITM1 expression in PK15 porcine kidney epithelial cells and 3D4/21 alveolar macrophages. pIFITM2 and pIFITM3 expression was only elevated in PK15 cells during PRV infection. Depletion of pIFITM1 using RNA interference, either in PK15 or in 3D4/21 cells, enhanced PRV infection while overexpression of pIFITM1 had the opposite effect. Knockdown of pIFITM2 and pIFITM3 did not influence PRV infection, suggesting that pIFITM2 and pIFITM3 are independent of PRV infection. PRV-induced pIFITM1 expression was dependent on the cGAS/STING/TBK1/IRF3 innate immune pathway and interferon-alpha receptor-1, suggesting that pIFITM1 is up-regulated by the type I interferon signaling pathway. The anti-PRV role of pIFITM1 was inhibited upon PRV entry. Our data demonstrate that pIFITM1 is a host restriction factor that inhibits PRV entry that may shed light on a strategy for prevention of PRV infection.

[Expressions of STAT3, VEGF and C-myc in seminoma and their significance].

OBJECTIVE: To understand the role of the JAK/STAT3 signal transduction pathway in the pathogenesis of seminoma by studying the expressions of signal transducers and activators of transcription-3 (STAT3), vascular endothelial growth factor (VEGF) and C-myc in seminoma. METHODS: We examined 38 paraffin specimens of seminoma and 10 samples of normal human testes by immunohistochemical staining using the antibodies of STAT3, VEGF and C-myc, and observed the staining intensity under the light microscope. RESULTS: The positive expression rates of STAT3, VEGF and C-myc were 76.3%, 71.1% and 84.2%, respectively, with statistically significant differences from the corresponding protein expressions in the normal testis tissues (P < 0.01), which gradually increased with the clinical stages of tumor, nodes and metastasis (TNM) classification. Different correlations were observed among the STAT3, VEGF and C-myc proteins in seminoma: STAT3 positively correlated with VEGF (r = 0.640, P < 0.01) and C-myc (r = 0.408, P < 0.05); C-myc positively correlated with VEGF (r = 0.459, P < 0.01). CONCLUSION: The JAK/STAT3 signal transduction pathway can facilitate the development and metastasis of seminoma by activating the expression of VEGF and meanwhile induce the malignant proliferation of primary reproductive cells and promote the pathogenesis and progression of seminoma by activating the expression of C-myc.