Vaccine Development for Severe Fever with Thrombocytopenia Syndrome Virus in Dogs.

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening viral zoonosis. The causative agent of this disease is the Dabie bandavirus, which is usually known as the SFTS virus (SFTSV). Although the role of vertebrates in SFTSV transmission to humans remains uncertain, some reports have suggested that dogs could potentially transmit SFTSV to humans. Consequently, preventive measures against SFTSV in dogs are urgently needed. In the present study, dogs were immunized three times at two-week intervals with formaldehyde-inactivated SFTSV with two types of adjuvants. SFTSV (KCD46) was injected into all dogs two weeks after the final immunization. Control dogs showed viremia from 2 to 4 days post infection (dpi), and displayed white pulp atrophy in the spleen, along with a high level of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling assay (TUNEL) positive area. However, the inactivated SFTSV vaccine groups exhibited rare pathological changes and significantly reduced TUNEL positive areas in the spleen. Furthermore, SFTSV viral loads were not detected at any of the tested dpi. Our results indicate that both adjuvants can be safely used in combination with an inactivated SFTSV formulation to induce strong neutralizing antibodies. Inactivated SFTSV vaccines effectively prevent pathogenicity and viremia in dogs infected with SFTSV. In conclusion, our study highlighted the potential of inactivated SFTSV vaccination for SFTSV control in dogs.

Short-term inhalation exposure to cigarette smoke induces oxidative stress and inflammation in lungs without systemic oxidative stress in mice.

Smoking is a well-established risk factor for various pathologies, including pulmonary diseases, cardiovascular disorders, and cancers. The toxic effects of cigarette smoke (CS) are mediated through multiple pathways and diverse mechanisms. A key pathogenic factor is oxidative stress, primarily induced by excessive formation of reactive oxygen species. However, it remains unclear whether smoking directly induces systemic oxidative stress or if such stress is a secondary consequence. This study aimed to determine whether short-term inhalation exposure to CS induces oxidative stress in extrapulmonary organs in addition to the lung in a murine model. In the experiment, 3R4F reference cigarettes were used to generate CS, and 8-week-old male BALB/c mice were exposed to CS at a total particulate matter concentration of either 0 or 800 µg/L for four consecutive days. CS exposure led to an increase in neutrophils, eosinophils, and total cell counts in bronchoalveolar lavage fluid. It also elevated levels of lactate dehydrogenase and malondialdehyde (MDA), markers indicative of tissue damage and oxidative stress, respectively. Conversely, no significant changes were observed in systemic oxidative stress markers such as total oxidant scavenging capacity, MDA, glutathione (GSH), and the GSH/GSSG ratio in blood samples. In line with these findings, CS exposure elevated NADPH oxidase (NOX)-dependent superoxide generation in the lung but not in other organs like the liver, kidney, heart, aorta, and brain. Collectively, our results indicate that short-term exposure to CS induces inflammation and oxidative stress in the lung without significantly affecting oxidative stress in extrapulmonary organs under the current experimental conditions. NOX may play a role in these pulmonary-specific events.

Difference in Intraspecies Transmissibility of Severe Fever with Thrombocytopenia Syndrome Virus Depending on Abrogating Type 1 Interferon Signaling in Mice.

Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne zoonotic disease, is caused by infection with SFTS virus (SFTSV). A previous study reported that human-to-human direct transmission of SFTSV can occur. However, potential animal-to-animal transmission of SFTSV without ticks has not been fully clarified. Thus, the objective of this study was to investigate potential mice-to-mice transmission of SFTSV by co-housing three groups of mice [i.e., wild-type mice (WT), mice injected with an anti-type I interferon-α receptor-blocking antibody (IFNAR Ab), and mice with knockout of type I interferon-α receptor (IFNAR KO)] as spreaders or recipients with different immune competence. As a result, co-housed IFNAR Ab and IFNAR KO mice showed body weight loss with SFTS viral antigens detected in their sera, extracorporeal secretions, and various organs. Based on histopathology, white pulp atrophy in the spleen was observed in all co-housed mice except WT mice. These results obviously show that IFNAR Ab and IFNAR KO mice, as spreaders, exhibited higher transmissibility to co-housed mice than WT mice. Moreover, IFNAR KO mice, as recipients, were more susceptible to SFTSV infection than WT mice. These findings suggest that type I interferon signaling is a pivotal factor in mice intraspecies transmissibility of SFTSV in the absence of vectors such as ticks.

Intradermal Inoculation of Inactivated Foot-and-Mouth Disease Vaccine Induced Effective Immune Responses Comparable to Conventional Intramuscular Injection in Pigs.

All pigs in the Republic of Korea are given the foot-and-mouth disease virus (FMDV) vaccine intramuscularly (IM) as part of the country's vaccination policy. However, the IM administration of the FMDV vaccine to pig results in residual vaccine components in the muscle and undesirable changes in muscle and soft tissues, causing economic losses in swine production. In this study, we evaluated whether intradermal (ID) vaccination could be proposed as an alternative to IM administration. ID vaccination (0.2 mL on each side of the neck muscle) and IM vaccination (2 mL on each side of the neck muscle) were performed twice, separated by 14 days, using a commercial FMD vaccine in specific-pathogen-free pigs. We observed growth performance, gross and microscopic lesions at the inoculation site, FMDV-specific antibodies, and neutralizing antibodies for 35 days after vaccination. Side effects on the skin grossly appeared following ID administration, but most were reduced within two weeks. All ID-vaccinated pigs showed inflammatory lesions limited to the dermis, but IM-vaccinated pigs had abnormal undesirable changes and pus in the muscle. ID-vaccinated pigs performed comparably to IM-vaccinated pigs in terms of growth, FMD virus-specific antibodies, protection capability against FMDV, and T-cell induction. This study demonstrated that the ID inoculation of the inactivated FMD vaccine induced immune responses comparable to an IM injection at 1/10 of the inoculation dose and that the inoculation lesion was limited to the dermis, effectively protecting against the formation of abnormal undesirable changes in muscle and soft tissues.

Amlexanox attenuates LPS-induced neuroinflammatory responses in microglial cells via inhibition of NF-κB and STAT3 signaling pathways.

Amlexanox is an anti-inflammatory and anti-allergic agent used clinically for the treatment of aphthous ulcers, allergic rhinitis, and asthma. Recent studies have demonstrated that amlexanox, a selective inhibitor of IkB kinase epsilon (IKKε) and TANK-binding kinase 1 (TBK1), suppresses a range of diseases or inflammatory conditions, such as obesity-related metabolic dysfunction and type 2 diabetes. However, the effects of amlexanox on neuroinflammatory responses to amlexanox have not yet been comprehensively studied. In this study, we investigated the novel therapeutic effect of amlexanox on LPS-induced neuroinflammation in vivo, and intraperitoneal injection of amlexanox markedly reduced LPS-induced IKKε levels, proinflammatory cytokines, and microglial activation, as evidenced by ionized calcium-binding adapter molecule 1 (Iba1) immunostaining. Furthermore, amlexanox significantly reduced proinflammatory cytokines and chemokines in LPS-induced bone marrow-derived macrophages (BMDM), murine BV2, and human HMC3 microglial cells. This data provided considerable evidence that amlexanox can be used as a preventive and curative therapy for neuroinflammatory and neurodegenerative diseases. In terms of mechanism aspects, our results demonstrated that the anti-inflammatory action of amlexanox in BV2 microglial cells was through the downregulation of NF-κB and STAT3 signaling pathways. In addition, the combination of amlexanox and SPI (a STAT3 selective inhibitor) showed high efficiency in inhibiting the production of neurotoxic and pro-inflammatory mediators. Overall, our data provide rational insights into the mechanisms of amlexanox as a potential therapeutic strategy for neuroinflammation-related diseases.

Nicotinamide adenine dinucleotide phosphate oxidase 2 deletion attenuates polyhexamethylene guanidine-induced lung injury in mice.

Inhalation of polyhexamethylene guanidine phosphate (PHMG) can cause pulmonary fibrosis. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox) are enzymes that produce reactive oxygen species, which may be involved in tissue damage in various lung diseases. To investigate whether the Nox2 isoform of Nox is involved in the progression of PHMG-induced lung damage, we studied the contribution of Nox2 in PHMG-induced lung injury in Nox2-deficient mice. We treated wild-type (WT) and Nox2 knockout mice with a single intratracheal instillation of 1.1 mg/kg PHMG and sacrificed them after 14 days. We analyzed lung histopathology and the number of total and differential cells in the bronchoalveolar lavage fluid. In addition, the expressions of cytokines, chemokines, and profibrogenic genes were analyzed in the lung tissues. Based on our results, Nox2-deficient mice showed less PHMG-induced pulmonary damage than WT mice, as indicated by parameters such as body weight, lung weight, total cell count, cytokine and chemokine levels, fibrogenic mediator expression, and histopathological findings. These findings suggest that Nox2 may have the potential to contribute to PHMG-induced lung injury and serves as an essential signaling molecule in the development of PHMG-induced pulmonary fibrosis by regulating the expression of profibrogenic genes.

Prevalence of porcine circovirus type 2 and type 3 in slaughtered pigs and wild boars in Korea.

BACKGROUND: Porcine circovirus, a non-enveloped single-stranded DNA virus belonging to the genus Circovirus of the family Circoviridae, is a major pathogen of porcine circovirus-associated disease. Porcine circovirus 3, a novel porcine circovirus, has been identified in individuals with clinical symptoms. OBJECTIVES: The prevalence of porcine circovirus 2 and porcine circovirus 3 and the confirmation of diagnosis of this emerging viral disease have not been fully studied yet. Therefore, the objective of the present study was to investigate the prevalence of porcine circovirus 2 and porcine circovirus 3 in slaughtered pigs and wild boars in Korea between 2018 and 2019. METHODS: Lungs and hilar lymph nodes of healthy pigs slaughtered in slaughterhouses and captured wild pigs were collected, and viruses were detected by multiplex quantitative polymerase chain reaction and two staining methods (in situ hybridization and immunohistochemistry) to confirm the presence of porcine circovirus 2 and porcine circovirus 3. RESULTS: Positive rates of porcine circovirus 2 in lungs and hilar lymph nodes were 78.1% (75/96) and 89.5% (86/96) in slaughtered pigs, respectively. They were 18.0% (30/167) and 46.3% (24/55) in wild boars, respectively. Positive rates of porcine circovirus 3 in lungs and hilar lymph nodes were 30.2% (29/96) and 13.5% (13/96) in slaughtered pigs, respectively. They were 4.2% (7/167) and 5.5% (3/55) in wild boars, respectively. At the farm level, positive rates of porcine circovirus 2 and porcine circovirus 3 were 97.9% (47/48) and 54.2% (26/48), respectively. Positive rates of porcine circovirus 2 and porcine circovirus 3 decreased in spring. Immunohistochemistry and in situ hybridization confirmed the presence of porcine circovirus 2 and porcine circovirus 3 in lungs, but not porcine circovirus 3 in the hilar lymph nodes. CONCLUSION: These results suggest that the prevalence of porcine circovirus 2 and porcine circovirus 3 might vary depending on the season and the type of sample. Wild boars might play a role in the epidemiology of porcine circovirus 2 and porcine circovirus 3 in South Korea. Continuous surveillance and further study are needed for this emerging disease.

SARS-CoV-2 exploits cellular RAD51 to promote viral propagation: implication of RAD51 inhibitor as a potential drug candidate against COVID-19.

IMPORTANCE: Viruses are constantly evolving to promote propagation in the host. Here, we show that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilizes host RAD51 for replication. Silencing of RAD51 impaired SARS-CoV-2 propagation. Viral RNA colocalized with RAD51 in the cytoplasm of SARS-CoV-2-infected cells, suggesting that both viral RNA and RAD51 may form a replication complex. We, therefore, evaluated RAD51 inhibitors as possible therapeutic agents against SARS-CoV-2. Indeed, RAD51 inhibitors exerted antiviral activities against not only Wuhan but also variants of SARS-CoV-2. Molecular docking model shows that RAD51 inhibitors impede SARS-CoV-2 propagation by interfering with dimerization of RAD51. These data suggest that RAD51 may represent a novel host-based drug target for coronavirus disease 2019 treatment.

A natural product YSK-A blocks SARS-CoV-2 propagation by targeting multiple host genes.

Natural products and herbal medicine have been widely used in drug discovery for treating infectious diseases. Recent outbreak of COVID-19 requires various therapeutic strategies. Here, we used YSK-A, a mixture of three herbal components Boswellia serrata, Commiphora myrrha, and propolis, to evaluate potential antiviral activity against SARS-CoV-2. We showed that YSK-A inhibited SARS-CoV-2 propagation with an IC50 values of 12.5 µg/ml and 15.42 µg/ml in Vero E6 and Calu-3 cells, respectively. Using transcriptome analysis, we further demonstrated that YSK-A modulated various host gene expressions in Calu-3 cells. Among these, we selected 9 antiviral- or immune-related host genes for further study. By siRNA-mediated knockdown experiment, we verified that MUC5AC, LIF, CEACAM1, and GDF15 host genes were involved in antiviral activity of YSK-A. Therefore, silencing of these genes nullified YSK-A-mediated inhibition of SARS-CoV-2 propagation. These data indicate that YSK-A displays an anti-SARS-CoV-2 activity by targeting multiple antiviral genes. Although the exact antiviral mechanism of each constituent has not been verified yet, our data indicate that YSK-A has an immunomodulatory effect on SARS-CoV-2 and thus it may represent a novel natural product-derived therapeutic agent for treating COVID-19.

Surveillance of wild animals carrying infectious agents based on high-throughput screening platform in the Republic of Korea.

BACKGROUND: Infectious diseases transmitted by wild animals are major threats to public health. This study aimed to investigate the potential of rescued wild animals that died of unknown causes as reservoirs of infectious agents. From 2018 to 2019, 121 dead wild animals (55 birds and 66 mammals) were included in this study. All wild animals died during treatment after anthropogenic events. After deaths of animals, necropsies were performed and trachea, lungs, large intestine (including stool), and spleen were collected to determine causes of deaths. A high-throughput screening (HTS) quantitative polymerase chain reaction (qPCR) designed to detect 19 pathogens simultaneously against 48 samples in duplicate was performed using nucleic acids extracted from pooled tissues and peripheral blood samples. If positive, singleplex real-time PCR was performed for individual organs or blood samples. RESULTS: The HTS qPCR showed positive results for Campylobacter jejuni (10/121, 8.3%), Campylobacter coli (1/121, 0.8%), Mycoplasma spp. (78/121, 64.5%), and Plasmodium spp. (7/121, 5.7%). Singleplex real-time PCR confirmed that C. jejuni was detected in the large intestine but not in the blood. C. coli was only detected in the large intestine. Mycoplasma spp. were detected in all organs, having the highest proportion in the large intestine and lowest in the blood. Plasmodium spp. was also detected in all organs, with proportions being were similar among organs. CONCLUSIONS: This study shows that wild animals can become carriers of infectious agents without showing any clinical symptoms.

Piperlongumine induces apoptosis and autophagy via the PI3K/Akt/mTOR pathway in KB human cervical cancer cells.

Natural products are continuously being researched to develop safe and effective treatment options for cervical cancer, the fourth most common cancer in women. Piperlongumine (PL), an amide alkaloid mainly present in long pepper, exhibits neuroprotective and anti-cancer properties. However, the specific effect of PL in cervical cancer and the relationship between the anti-cancer pathway and autophagy remain unclear. Therefore, we aimed to investigate PL-induced apoptosis in KB human cervical cancer cells and the relationship between apoptosis and autophagy therein. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound-healing assays showed that PL treatment suppressed KB cell viability and proliferation. Apoptosis was identified through 4',6-diamidino-2-phenylindole and annexin V-propidium iodide staining, increased cleaved-poly (ADP-ribose) polymerase and Bcl-2 associated X levels, and decreased B cell lymphoma 2 levels. Acridine orange staining and increased microtubule-associated protein 1A/1B-light chain 3-II and Beclin-1 levels confirmed autophagy. We determined that KB cell-related autophagy exerted cytoprotective effects using the autophagy inhibitors 3-methyladenine and hydroxychloroquine. PL treatment promoted apoptosis by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin pathway in KB cells; inhibiting the pathway using PI3K inhibitors increased autophagy. We suggest that PL is a potential natural anticancer agent for cervical cancer treatment.

TLR7 activation by miR-21 promotes renal fibrosis by activating the pro-inflammatory signaling pathway in tubule epithelial cells.

BACKGROUND: Toll-like receptor 7 (TLR7) is an endosomal TLR activated by single-stranded RNA, including endogenous microRNAs. Although TLR7 is known to promote inflammatory responses in pathophysiological conditions, its role in renal fibrosis has not been investigated. Here, we aim to investigate the inflammatory roles of TLR7 in kidney inflammation and fibrosis. METHODS: TLR7 knockout mice (Tlr7 -/-) subjected to AD-induced kidney injury were utilized to examine the role of TLR7 in kidney fibrosis. To elucidate the role of TLR7 in renal epithelial cells, NRK52E rat renal tubule epithelial cells were employed. RESULTS: Under fibrotic conditions induced by an adenine diet (AD), TLR7 was significantly increased in damaged tubule epithelial cells, where macrophages were highly infiltrated. TLR7 deficiency protected against AD-induced tubular damage, inflammation, and renal fibrosis. Under in vitro conditions, TLR7 activation increased NF-κB activity and induced chemokine expression, whereas TLR7 inhibition effectively blocked NF-κB activation. Furthermore, among the known TLR7 endogenous ligands, miR-21 was significantly upregulated in the tubular epithelial regions. In NRK52E cells, miR-21 treatment induced pro-inflammatory responses, which could be blocked by a TLR7 inhibitor. When the TLR7 inhibitor, M5049, was administered to the AD-induced renal fibrosis model, TLR7 inhibition significantly attenuated AD-induced renal inflammation and fibrosis. CONCLUSIONS: Overall, activation of TLR7 by endogenous miR-21 in renal epithelial cells contributes to inflammatory responses in a renal fibrosis model, suggesting a possible therapeutic target for the treatment of renal fibrosis. Video Abstract.

Assessment of BoHV-4-based vector vaccine intranasally administered in a hamster challenge model of lung disease.

Introduction: Bovine herpesvirus 4 (BoHV-4) is a bovine Rhadinovirus not associated with a specific pathological lesion or disease and experimentally employed as a viral vector vaccine. BoHV-4-based vector (BoHV-4-BV) has been shown to be effective in immunizing and protecting several animal species when systemically administrated through intramuscular, subcutaneous, intravenous, or intraperitoneal routes. However, whether BoHV-4-BV affords respiratory disease protection when administered intranasally has never been tested. Methods: In the present study, recombinant BoHV-4, BoHV-4-A-S-ΔRS-HA-ΔTK, was constructed to deliver an expression cassette for the SARS-CoV-2 spike glycoprotein, and its immunogenicity, as well as its capability to transduce cells of the respiratory tract, were tested in mice. The well-established COVID-19/Syrian hamster model was adopted to test the efficacy of intranasally administered BoHV-4-A-S-ΔRS-HA-ΔTK in protecting against a SARS-CoV-2 challenge. Results: The intranasal administration of BoHV-4-A-S-ΔRS-HA-ΔTK elicited protection against SARS-CoV-2, with improved clinical signs, including significant reductions in body weight loss, significant reductions in viral load in the trachea and lungs, and significant reductions in histopathologic lung lesions compared to BoHV-4-A-S-ΔRS-HA-ΔTK administered intramuscularly. Discussion: These results suggested that intranasal immunization with BoHV-4-BV induced protective immunity and that BoHV-4-BV could be a potential vaccine platform for the protection of other animal species against respiratory diseases.

Toll-like receptor-7 signaling in Kupffer cells exacerbates concanavalin A-induced liver injury in mice.

Concanavalin A (ConA) is a plant lectin that can induce immune-mediated liver damage. ConA induced liver damage animal model is a widely accepted model that can mimic clinical acute hepatitis and immune-mediated liver injury in humans. Toll-like receptor-7 (TLR7), a member of the TLR family, plays a key role in pathogen recognition and innate immune activation. The aim of this study was to examine the role of TLR7 in the pathogenesis of ConA-induced liver injury. Acute liver injury was induced by intravenous injection with ConA in WT (wild-type) and TLR7 knockout (KO) mice. Results showed that attenuated liver injury in TLR7-deficient mice, as indicated by increased survival rate, decreased aminotransferase levels, and reduced pathological lesions, was associated with decreased release of pro-inflammatory cytokines in livers. Consistently, significantly decreased proliferation of CD4+ T cell was detected in ConA-stimulated TLR7-deficient splenocytes, but not in CD3/CD28 stimulated TLR7-deficient CD4+ T cells. Moreover, TLR7 deficiency in KCs specifically suppressed the expression of TNF-α (tumor necrosis factor-α). Depletion of KCs abolished the detrimental role of TLR7 in ConA-induced liver injury. Taken together, these results demonstrate that TLR7 can regulate the expression of TNF-α in KCs, which is necessary for the full progression of ConA-induced liver injury.

The presence of anthracosis is associated with the environmental air quality of zoo, wildlife, and companion animals in Jeollabuk-do Province, South Korea.

OBJECTIVE: To determine pulmonary anthracosis in zoo, wildlife, and companion animals of Jeollabuk-do Province, South Korea. ANIMALS: A total of 350 animals of 61 different species, belonging to 3 classes (mammals: n = 38; avian: 21; and reptiles: 2) from different habitats in Jeollabuk-do Province, were examined. PROCEDURES: Gross lung examination and tissue sampling were done at postmortem, and histopathological analysis was microscopically done on hematoxylin and eosin-stained slides. RESULTS: Macroscopic analysis of anthracotic lung tissue revealed minute (pinpoint size) spots and black pigmentation in a scattered and/or coalescing fashion. The presence of carbon particles was noted in 154 (44%, 154/350) cases. Based on habitation, zoo animals had the highest frequency of anthracosis in the lung (55.2%, 69/125), followed by companion animals (45.2%, 56/124) and wildlife animals (28.7%, 29/101). There was an association between habitation and the presence of anthracosis (P < .05). CLINICAL RELEVANCE: This study revealed evidence that the presence of anthracosis is associated with the environmental air quality of zoo, wildlife, and companion animals in Jeollabuk-do Province, South Korea. Air pollution may affect the respiratory health of the endangered species at the Jeonju Zoo as well as the human population. Continuous monitoring of particulate matter and establishing policies that control industrialization around the province would enable quick action to curb any potential respiratory health risks to animals kept in the urban cities of the province.

Immune response following safer administration of recombinant Salmonella Typhimurium harboring ASFV antigens in pigs.

African swine fever virus (ASFV) is a contagious epizootic pathogen adversely affecting porcine industry in Asian and European countries. Till date, 8 serotypes and 24 genotypes of the virus have been reported. Few live attenuated virus vaccine studies have reported to provide complete protection against ASFV infection but biohazard concern still remain. Recombinant subunit antigens are capable of providing cellular and humoral immunity in porcine, but not a single vaccine has hit the market yet. In the present study, we attempted to use recombinant Salmonella Typhimurium JOL912 strain harboring ASFV antigens (rSal-ASFV) to investigate its immunostimulant effect in porcine. Post intramuscular administration, we observed significant increment in the levels of helper T cells, cytotoxic T cells, natural killer (NK) cells, and immunoglobulin (i.e. IgG, IgA, and IgM) levels in rSal-ASFV treated groups. Further RT-PCR analysis indicated the increased expression of MHC-I, MHC-II, CD80/86, NK cell receptors (NKp30, NKp44, and NKp46) and cytokines while ELIspot analysis revealed significant production of IFN-γ in rSal-ASFV treated groups. Taken together, we are able to demonstrate that rSal-ASFV could elicit a non-specific cellular as well as humoral immune response. However, additional antigen specific immunity data is needed to evaluate its efficacy. Intramuscular administration of rSal-ASFV was found to be safe and immunostimulant in nature without any side-effects and may serve as an excellent option for in-vivo antigen delivery in pigs.

Effects of maternal cigarette smoke exposure on the progression of nonalcoholic steatohepatitis in offspring mice.

Cigarette smoke (CS) is a dominant carcinogenic agent in a variety of human cancers. CS exposure during pregnancy can adversely affect the fetus. Non-alcoholic fatty liver disease (NAFLD) is considered as a hepatic manifestation of a metabolic disorder, and ranges from simple steatosis to cirrhosis leading to hepatocellular carcinoma. Non-alcoholic steatohepatitis (NASH) is a more severe phase of NAFLD. Recently, there is increasing apprehension about the CS-related chronic liver diseases. Therefore, we examined whether maternal CS exposure could affect the pathogenesis of NASH in offspring. Mainstream CS (MSCS) was exposed to pregnant C57BL/6 mice via nose-only inhalation for 2 h/day, 5 days/week for 2 weeks from day 6 to 17 of gestation at 0, 300, or 600 µg/L. Three-week-old male offspring mice were fed methionine and choline-supplemented (MCS) diet or methionine and choline-deficient including high-fat (MCDHF) diet for 6 weeks to induce NASH. Maternal MSCS exposure increased the severity of NASH by increasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, hepatic total cholesterol (TC) and triglyceride (TG) levels, pro-inflammation, fibrosis, and steatosis in offspring mice. Especially, maternal MSCS exposure significantly downregulated the phosphorylation of AMP-activated protein kinase (AMPK) in MCDHF diet-fed offspring mice. Subsequently, the protein levels of sterol regulatory element-binding protein (SREBP)-1c and stearoyl-CoA desaturase-1 (SCD1) were upregulated by maternal MSCS exposure. In conclusion, maternal MSCS exposure exacerbates the progression of NASH by modulating lipogenesis on offspring mice. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-022-00153-1.

Delta (B1.617.2) variant of SARS-CoV-2 induces severe neurotropic patterns in K18-hACE2 mice.

A highly contagious virus, severe acute respiratory syndrome coronavirus 2, caused the coronavirus disease 19 (COVID-19) pandemic (SARS-CoV-2). SARS-CoV-2 genetic variants have been reported to circulate throughout the COVID-19 pandemic. COVID-19 symptoms include respiratory symptoms, fever, muscle pain, and breathing difficulty. In addition, up to 30% of COVID-19 patients experience neurological complications such as headaches, nausea, stroke, and anosmia. However, the neurotropism of SARS-CoV-2 infection remains largely unknown. This study investigated the neurotropic patterns between the B1.617.2 (Delta) and Hu-1 variants (Wuhan, early strain) in K18-hACE2 mice. Despite both the variants inducing similar pathogenic patterns in various organs, B1.617.2-infected K18-hACE2 mice demonstrated a higher range of disease phenotypes such as weight loss, lethality, and conjunctivitis when compared to those in Hu-1-infected mice. In addition, histopathological analysis revealed that B1.617.2 infects the brain of K18-hACE2 mice more rapidly and effectively than Hu-1. Finally, we discovered that, in B1.617.2-infected mice, the early activation of various signature genes involved innate cytokines and that the necrosis-related response was most pronounced than that in Hu-1-infected mice. The present findings indicate the neuroinvasive properties of SARS-CoV-2 variants in K18-hACE2 mice and link them to fatal neuro-dissemination during the disease onset.

Polypropylene nanoplastic exposure leads to lung inflammation through p38-mediated NF-κB pathway due to mitochondrial damage.

BACKGROUND: Polypropylene (PP) is used in various products such as disposable containers, spoons, and automobile parts. The disposable masks used for COVID-19 prevention mainly comprise PP, and the disposal of such masks is concerning because of the potential environmental pollution. Recent reports have suggested that weathered PP microparticles can be inhaled, however, the inhalation toxicology of PP microparticles is poorly understood. RESULTS: Inflammatory cell numbers, reactive oxygen species (ROS) production, and the levels of inflammatory cytokines and chemokines in PP-instilled mice (2.5 or 5 mg/kg) increased significantly compared to with those in the control. Histopathological analysis of the lung tissue of PP-stimulated mice revealed lung injuries, including the infiltration of inflammatory cells into the perivascular/parenchymal space, alveolar epithelial hyperplasia, and foamy macrophage aggregates. The in vitro study indicated that PP stimulation causes mitochondrial dysfunction including mitochondrial depolarization and decreased adenosine triphosphate (ATP) levels. PP stimulation led to cytotoxicity, ROS production, increase of inflammatory cytokines, and cell deaths in A549 cells. The results showed that PP stimulation increased the p-p38 and p-NF-κB protein levels both in vivo and in vitro, while p-ERK and p-JNK remained unchanged. Interestingly, the cytotoxicity that was induced by PP exposure was regulated by p38 and ROS inhibition in A549 cells. CONCLUSIONS: These results suggest that PP stimulation may contribute to inflammation pathogenesis via the p38 phosphorylation-mediated NF-κB pathway as a result of mitochondrial damage.