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This "Best Practices in User Consultation" article is the result of a 2022 International Society for the Advancement of Cytometry (ISAC) membership survey that collected valuable insights from the shared research laboratory (SRL) community and of a group discussion at the CYTO 2022 workshop of the same name. One key takeaway is the importance of initiating a consultation at the outset of a flow cytometry project, particularly for trainees. This approach enables the improvement and standardization of every step, from planning experiments to interpreting data. This proactive approach effectively mitigates experimental bias and avoids superfluous trial and error, thereby conserving valuable time and resources. In addition to guidelines, the optimal approaches for user consultation specify communication channels, methods, and critical information, thereby establishing a structure for productive correspondence between SRL and users. This framework functions as an exemplar for establishing robust and autonomous collaborative relationships. User consultation adds value by providing researchers with the necessary information to conduct reproducible flow cytometry experiments that adhere to scientific rigor. By following the steps, instructions, and strategies outlined in these best practices, an SRL can readily tailor them to its own setting, establishing a personalized workflow and formalizing user consultation services. This article provides a pragmatic guide for improving the caliber and efficacy of flow cytometry research and aggregates the flow cytometry SRL community's collective knowledge regarding user consultation.
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Background: We aimed to observe the effect of extended care on improving motor function and activities of daily living of stroke-induced hemiplegic patients. Methods: Patients clinically diagnosed as stroke with hemiplegia and hospitalized in the Neurology Department at Tianjin Haibin People's Hospital, China from 2019 to 2020 were selected. One hundred twenty patients were enrolled and randomly divided into the intervention group (60 patients) and the control group (60 patients). The control group was given routine rehabilitation treatment and care. Based on routine rehabilitation treatment and care, the intervention group was given transitional care. After discharge, the patients were followed up. Barthel indexes (BIs) were collected to evaluate the activities of daily living of patients. The Fugl-Meyer Motor Function Assessment (FMA) was adopted to evaluate the patients' motor function. Results: There was no statistically significant difference in the total BI scores between the two groups of patients at the two time points before intervention and at discharge. The total scores of the intervention group were higher than those of the control group after 1 month and 3 months of discharge, and the difference was statistically significant (P<0.05). There was no statistically significant difference in total FMA scores between the two groups of patients before intervention, indicating comparability. After 3 months of discharge, the total FMA score of the intervention group patients was higher than that of the control group, and the differences were statistically significant (P<0.05). Conclusion: Continuous care can effectively improve motor function and daily living ability of stroke patients with hemiplegia.
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Objective: This study aimed to analyze the effect of modular nursing model for typical issues on enteral nutrition status, immune function, and quality of life in patients with colon cancer. Methods: The clinical data of 106 colorectal cancer patients who came to our hospital from January 2020 to January 2022 were retrospectively analyzed. The patients were randomized into the control and observation group based on the different nursing models, with 53 cases in each group. The patients in the control group received a simple enteral nutrition nursing model, while these in the observation group were administrated with a modular nursing model for typical issues on the basis of the control group. The differences in enteral nutrition status, immune function, and quality of life indicators of patients before and after nursing were counted and compared between the two groups. Results: After the nursing, the contents of albumin, serum albumin, and transferrin were all elevated in both two groups compared with these before the nursing (P < 0.001), and these contents in observation group was markedly higher than these in the control group after the nursing (P < 0.001). The expressions of immune function indicators, including CD3+, CD4+, CD4+/CD8+, and SIgA of the two groups after the nursing, were much higher than these before the nursing (P < 0.05), while the contents of CD8+ and IgG were sharply decreased in comparison with these before the nursing (P < 0.05). The improvement of immune indicators in the observation group after the nursing was strongly better than that in the control (P < 0.01). The proportion of the total nursing satisfaction was significantly higher in the observation group than that in the control (P < 0.05). After the nursing, the life quality scores of two groups were both strongly elevated (P < 0.05), and the improvement of life quality scores were memorably better in the observation group after nursing than these in the control (P < 0.01). Conclusion: For patients undergoing radical colon cancer resection, modular nursing model for typical issues in the early postoperative period is not only safe, but also improves enteral nutrition, can better maintain immune function in the early postoperative period, improve nursing satisfaction, improve patient prognosis, and promote the improvement of the condition, which is worthy of popularization and application.
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Classical swine fever virus (CSFV) is a highly pathogenic RNA virus belonging to the Flaviviridae family that can cause deadly classical swine fever (CSF) in pigs. However, the molecular details of virus replication in the host are still unclear. Our previous studies have reported that several Rab proteins mediate CSFV entry into host cells, but it is unknown whether CSFV hijacks other Rab proteins for effective viral infection. Here, we systematically studied the role of Rab14 protein in regulating lipid metabolism for promoting viral assembly. First, Rab14 knockdown and overexpression significantly affected CSFV replication, indicating the essential role of Rab14 in CSFV infection. Interestingly, Rab14 could significantly affect virus replication in the late stage of infection. Mechanistically, CSFV NS5A recruited Rab14 to the ER, followed by ceramide transportation to the Golgi apparatus, where sphingomyelin was synthesized. The experimental data of small molecule inhibitors, RNA interference, and replenishment assay showed that the phosphatidylinositol-3-kinase (PI3K)/AKT/AS160 signaling pathway regulated the function of Rab14 to affect the transport of ceramide. More importantly, sphingomyelin on the Golgi apparatus contributed to the assembly of viral particles. Blockage of the Rab14 regulatory pathway induced the reduction of the content of sphingomyelin on the Golgi apparatus, impairing the assembly of virus particles. Our study clarifies that Rab14 regulates lipid metabolism and promotes CSFV replication, which provides insight into a novel function of Rab14 in regulating vesicles to transport lipids to the viral assembly factory. IMPORTANCE The Rab protein family members participate in the viral replication of multiple viruses and play important roles in the virus infection cycle. Our previous research focused on Rab5/7/11, which regulated the trafficking of vesicles in the early stage of CSFV infection, especially in viral endocytosis. However, the role of other Rab proteins in CSFV replication is unclear and needs further clarification. Strikingly, we screened some Rabs and found the important role of Rab14 in CSFV infection. Virus infection mobilized Rab14 to regulate the vesicle to transport ceramide from the ER to the Golgi apparatus, further promoting the synthesis of sphingomyelin and facilitating virus assembly. The treatment of inhibitors showed that the lipid transport mediated by Rab14 was regulated by the PI3K/AKT/AS160 signaling pathway. Knockdown of Rab14 or the treatment with PI3K/AKT/AS160 inhibitors reduced the ceramide content in infected cells and hindered virus assembly. Our study is the first to explain that vesicular lipid transport regulated by Rab promotes CSFV assembly, which is conducive to the development of antiviral drugs.
Subject(s)
Ceramides , Classical Swine Fever Virus , Monomeric GTP-Binding Proteins , Virus Assembly , Animals , Ceramides/metabolism , Classical Swine Fever , Classical Swine Fever Virus/genetics , Classical Swine Fever Virus/physiology , Endoplasmic Reticulum/metabolism , Golgi Apparatus/metabolism , Monomeric GTP-Binding Proteins/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Sphingomyelins/metabolism , Swine , Virus ReplicationABSTRACT
Vimentin (VIM), an indispensable protein, is responsible for the formation of intermediate filament structures within cells and plays a crucial role in viral infections. However, the precise role of VIM in classical swine fever virus (CSFV) infection remains unclear. Herein, we systematically investigated the function of VIM in CSFV replication. We demonstrated that both knockdown and overexpression of VIM affected CSFV replication. Furthermore, we observed by confocal microscopy the rearrangement of cellular VIM into a cage-like structure during CSFV infection. Three-dimensional (3D) imaging indicated that the cage-like structures were localized in the endoplasmic reticulum (ER) and ringed around the double-stranded RNA (dsRNA), thereby suggesting that VIM was associated with the formation of the viral replication complex (VRC). Mechanistically, phosphorylation of VIM at serine 72 (Ser72), regulated by the RhoA/ROCK signaling pathway, induced VIM rearrangement upon CSFV infection. Confocal microscopy and coimmunoprecipitation assays revealed that VIM colocalized and interacted with CSFV NS5A. Structurally, it was determined that amino acids 96 to 407 of VIM and amino acids 251 to 416 of NS5A were the respective important domains for this interaction. Importantly, both VIM knockdown and disruption of VIM rearrangement inhibited the localization of NS5A in the ER, implying that VIM rearrangement recruited NS5A to the ER for VRC formation. Collectively, our results suggest that VIM recruits NS5A to form a stable VRC that is protected by the cage-like structure formed by VIM rearrangement, ultimately leading to enhanced virus replication. These findings highlight the critical role of VIM in the formation and stabilization of VRC, which provides alternative strategies for the development of antiviral drugs. IMPORTANCE Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a highly infectious disease that poses a significant threat to the global pig industry. Therefore, gaining insights into the virus and its interaction with host cells is crucial for developing effective antiviral measures and controlling the spread of CSF. Previous studies have shown that CSFV infection induces rearrangement of the endoplasmic reticulum, leading to the formation of small vesicular organelles containing nonstructural protein and double-stranded RNA of CSFV, as well as some host factors. These organelles then assemble into viral replication complexes (VRCs). In this study, we have discovered that VIM recruited CSFV NS5A to form a stable VRC that was protected by a cage-like structure formed by rearranged VIM. This enhanced viral replication. Our findings not only shed light on the molecular mechanism of CSFV replication but also offer new insights into the development of antiviral strategies for controlling CSFV.
Subject(s)
Classical Swine Fever Virus , Classical Swine Fever , Swine , Animals , Classical Swine Fever Virus/physiology , Vimentin/metabolism , RNA, Double-Stranded , Intermediate Filaments/metabolism , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism , Virus Replication , Antiviral Agents , Amino Acids/geneticsABSTRACT
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is an important and highly infectious pig disease worldwide. Kinesin-1, a molecular motor responsible for transporting cargo along the microtubule, has been demonstrated to be involved in the infections of diverse viruses. However, the role of kinesin-1 in the CSFV life cycle remains unknown. Here, we first found that Kif5B played a positive role in CSFV entry by knockdown or overexpression of Kif5B. Subsequently, we showed that Kif5B was associated with the endosomal and lysosomal trafficking of CSFV in the early stage of CSFV infection, which was reflected by the colocalization of Kif5B and Rab7, Rab11, or Lamp1. Interestingly, trichostatin A (TSA) treatment promoted CSFV proliferation, suggesting that microtubule acetylation facilitated CSFV endocytosis. The results of chemical inhibitors and RNA interference showed that Rac1 and Cdc42 induced microtubule acetylation after CSFV infection. Furthermore, confocal microscopy revealed that cooperation between Kif5B and dynein help CSFV particles move in both directions along microtubules. Collectively, our study shed light on the role of kinesin motor Kif5B in CSFV endocytic trafficking, indicating the dynein/kinesin-mediated bidirectional CSFV movement. The elucidation of this study provides the foundation for developing CSFV antiviral drugs. IMPORTANCE The minus end-directed cytoplasmic dynein and the plus end-directed kinesin-1 are the molecular motors that transport cargo on microtubules in intracellular trafficking, which plays a notable role in the life cycles of diverse viruses. Our previous studies have reported that the CSFV entry host cell is dependent on the microtubule-based motor dynein. However, little is known about the involvement of kinesin-1 in CSFV infection. Here, we revealed the critical role of kinesin-1 that regulated the viral endocytosis along acetylated microtubules induced by Cdc42 and Rac1 after CSFV entry. Mechanistically, once CSFV transported by dynein met an obstacle, it recruited kinesin-1 to move in reverse to the anchor position. This study extends the theoretical basis of intracellular transport of CSFV and provides a potential target for the control and treatment of CSFV infection.
Subject(s)
Classical Swine Fever Virus , Classical Swine Fever , Kinesins , Animals , Classical Swine Fever Virus/physiology , Dyneins/metabolism , Endocytosis , Kinesins/genetics , Kinesins/metabolism , Microtubules/metabolism , Microtubules/virology , Swine , Virus Internalization , Virus Replication/drug effects , Protein Synthesis Inhibitors/pharmacology , Protein TransportABSTRACT
Background: The relationship between a single food or nutrient and pulmonary tuberculosis (TB) has been explored in many studies; however, the relationship between dietary patterns and TB is still lacking. Objective: Our study aims to investigate the association between dietary patterns and the initial clinical manifestations in patients with TB. Materials and methods: A cross-sectional study including 1,661 patients with active TB was conducted in Qingdao, China, from 2011 to 2019. A semiquantitative food frequency questionnaire was used to collect dietary data. Dietary patterns were determined by principal component factor analysis. Initial clinical manifestations were assessed using a combination of the patient self-reported clinical symptoms and the admission results indicated by the TB score. The associations between dietary patterns and TB scores in patients with TB were examined by the logistics regression model. Results: The analysis identified four dietary patterns: meat-fruit-seafood pattern; dairy-egg pattern; beans and their products-whole grain pattern; and refined grain-vegetable pattern. In a multiple-adjusted model, higher adherence to the meat-fruit-seafood pattern showed a protective effect on the TB score (OR 0.53, 95% CI 0.39, 0.84, P for trend = 0.010) and the association was stronger in patients older than 45 years (OR 0.32, 95% CI 0.16, 0.64, P for trend < 0.001). The higher adherence to beans and their products-whole grain pattern was a protective factor for TB score (OR 0.57, 95% CI 0.37, 0.87, P for trend = 0.025), and the association was also observed in patients with concurrent TB and diabetes mellitus (DM) with a more significant effect (OR 0.33, 95% CI 0.14, 0.80, P for trend = 0.025). No significant association was found between dairy-egg pattern and refined grain-vegetable dietary pattern with TB score. Conclusion: Dietary patterns characterized by a balanced diet rich in high-quality protein, sufficient energy, as well as marine n-3 PUFA, phytochemicals, B vitamins, and fiber are associated with mild initial clinical manifestations, and the association is stronger in patients older than 45 years and those with concurrent TB and DM.
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BACKGROUND: This study aimed to investigate the effects of ultrasound-guided quadratus lumborum block (QLB) on perioperative multimodal analgesia and postoperative outcomes in patients undergoing radical prostatectomy. METHODS: A total of 80 patients undergoing radical prostatectomy were randomly divided into two groups: general anaesthesia with QLB (QLB group; n = 40) and general anaesthesia with sham QLB (normal saline [NS] group; n = 40). QLB or sham QLB was performed before the induction of anaesthesia. Sufentanil was intravenously administered for postoperative analgesia. The primary outcome was the pain score (measured using a numerical rating scale [NRS]) at different time points within 48 h postoperatively. Secondary outcomes included the cumulative dose of sufentanil within 48 h postoperatively, subjective comfort, grip strength, first time of exhaustion, first fluid intake time, time to get out of bed, length of postoperative hospital stay and overall satisfaction. The SPSS software, version 17.0, was used for all statistical analyses. RESULTS: Postoperative NRS at rest was significantly lower at 2 h (1.7 ± 1.1 versus 3.0 ± 2.1), 4 h (1.8 ± 1.2 versus 4.1 ± 2.3), 6 h (1.9 ± 2 versus 4.4 ± 2) and 12 h (3.5 ± 2.3 versus 5 ± 3.3) and was also lower when coughing at 2 h (2.3 ± 1.1 versus 4 ± 2.1), 4 h (2.3 ± 1. 1 versus 4.3 ± 2) and 6 h (2.4 ± 1.1 versus 5.9 ± 2.3) in the QLB than that in the NS group. The cumulative dose of sufentanil was significantly lower in the QLB than that in the NS group at 4 h, 6 h, 12 h, 24 h and 48 h. The nausea score was significantly lower in the QLB group at 24 h postoperatively, and the first time of exhaustion and time to get out of bed were significantly shorter (P < 0.05). The overall satisfaction score was significantly higher in the QLB than in the NS group (4 ± 0.7 versus 2.6 ± 0.9). CONCLUSION: Ultrasound-guided bilateral QLB can provide effective postoperative analgesia for patients undergoing radical prostatectomy, reduce the need for sufentanil, facilitate comfort and improve postoperative outcomes. QLB can be a good component of multimodal analgesia. TRIAL REGISTRATION: The clinical trial is registered in the Chinese Clinical Trial Registry (ChiCTR). Current Controlled Trials: ChiCTR1900022009 . the date of registration:2019/03/20.
Subject(s)
Analgesia , Sufentanil , Anesthetics, Local , Humans , Male , Pain, Postoperative/prevention & control , Prostatectomy , Ultrasonography, InterventionalABSTRACT
Classical swine fever virus (CSFV), a member of the Flaviviridae enveloped RNA virus family, results in an epidemic disease that brings serious economic losses to the pig industry worldwide. Valosin-containing protein (VCP/p97), a multifunctional active protein in cells, is related to the life activities of many viruses. However, the role of VCP in CSFV infection remains unknown. In this study, it was first found that treatment of VCP inhibitors impaired CSFV propagation. Furthermore, overexpression or knockdown of VCP showed that it was essential for CSFV infection. Moreover, confocal microscopy and immunoprecipitation assay showed that VCP was recruited for intracellular transport from early endosomes to lysosomes. Importantly, knockdown of VCP prevented CSFV to release from early endosomes, suggesting that VCP is a key factor for CSFV trafficking. Taken together, our findings first demonstrate that the endocytosis of CSFV into PK-15 cells requires the participation of VCP, providing the alternative approach for the discovery of novel anti-flaviviridae drugs.
Subject(s)
Classical Swine Fever Virus , Classical Swine Fever , Swine Diseases , Animals , Classical Swine Fever Virus/physiology , Endocytosis , Immunoprecipitation/veterinary , Lysosomes/metabolism , Swine , Swine Diseases/metabolism , Valosin Containing Protein/genetics , Valosin Containing Protein/metabolism , Virus ReplicationABSTRACT
As the important molecular machinery for membrane protein sorting in eukaryotic cells, the endosomal sorting and transport complexes (ESCRT-0/I/II/III and VPS4) usually participate in various replication stages of enveloped viruses, such as endocytosis and budding. The main subunit of ESCRT-I, Tsg101, has been previously revealed to play a role in the entry and replication of classical swine fever virus (CSFV). However, the effect of the whole ESCRT machinery during CSFV infection has not yet been well defined. Here, we systematically determine the effects of subunits of ESCRT on entry, replication, and budding of CSFV by genetic analysis. We show that EAP20 (VPS25) (ESCRT-II), CHMP4B and CHMP7 (ESCRT-III) regulate CSFV entry and assist vesicles in transporting CSFV from Clathrin, early endosomes, late endosomes to lysosomes. Importantly, we first demonstrate that HRS (ESCRT-0), VPS28 (ESCRT-I), VPS25 (ESCRT-II) and adaptor protein ALIX play important roles in the formation of virus replication complexes (VRC) together with CHMP2B/4B/7 (ESCRT-III), and VPS4A. Further analyses reveal these subunits interact with CSFV nonstructural proteins (NS) and locate in the endoplasmic reticulum, but not Golgi, suggesting the role of ESCRT in regulating VRC assembly. In addition, we demonstrate that VPS4A is close to lipid droplets (LDs), indicating the importance of lipid metabolism in the formation of VRC and nucleic acid production. Altogether, we draw a new picture of cellular ESCRT machinery in CSFV entry and VRC formation, which could provide alternative strategies for preventing and controlling the diseases caused by CSFV or other Pestivirus.
Subject(s)
Classical Swine Fever Virus/metabolism , Classical Swine Fever/virology , Endosomal Sorting Complexes Required for Transport/metabolism , RNA/metabolism , Viral Nonstructural Proteins/metabolism , Animals , Cell Line , Classical Swine Fever Virus/genetics , Clathrin/metabolism , Endoplasmic Reticulum/metabolism , Host Microbial Interactions , Swine , Transport Vesicles , Virus Internalization , Virus ReplicationABSTRACT
Lung cancer is a common cancer type, and has the highest mortality rate in the world. A genomewide association study suggests that the genetic marker rs9390123 is significantly associated with DNA repair capacity (DRC) in lung cancer. Analysis of the data derived from the 1000 Genomes Project indicated that there is another single nucleotide polymorphism (SNP), rs9399451, in strong linkage disequilibrium with rs9390123 in Caucasian individuals, thus suggesting that this SNP could be associated with DRC. However, the causal SNP and mechanism of DRC remain unclear. In the present study, dual luciferase assay results indicated that both SNPs are functional in lung cells. Through chromosome conformation capture, an enhancer containing the two functional SNPs was observed to bind the promoter of peroxisomal biogenesis factor 3 and phosphatase and actin regulator 2 antisense RNA 1 (PHACTR2AS1). Knockdown of PHACTR2AS1 could significantly influence lung cell proliferation, colony formation, migration and wound healing, which verified that PHACTR2AS1 is a novel oncogene for lung cancer. Through chromatin immunoprecipitation, the transcription factor POU class 2 homeobox 1 (POU2F1) was identified to bind to the surrounding segments of these two SNPs, and their interaction was investigated. The present study identified the mechanism via which rs9390123 and rs9399451 could influence DRC.
Subject(s)
DNA Repair/genetics , Lipoproteins/genetics , Lung Neoplasms/genetics , Membrane Proteins/genetics , Microfilament Proteins/genetics , Nerve Tissue Proteins/genetics , Peroxins/genetics , Polymorphism, Single Nucleotide/genetics , RNA, Antisense/genetics , Gene Expression Regulation, Neoplastic , Genome-Wide Association Study , Humans , Oncogenes/geneticsABSTRACT
Although previous reports have shown that Curcumin inhibits many viruses, including some important members of different genera of Flaviviridae family (Japanese encephalitis virus, dengue virus and hepatitis C virus), the antiviral activity of curcumin against Classical swine fever virus (CSFV), which belongs to Pestivirus genus, is still unclear. In this study, we found that curcumin inhibited CSFV replication in a dose-dependent manner, but had no effect on virus adsorption and entry. Furthermore, the results showed that curcumin inhibited the expression of FASN, one of the key enzymes of fatty acid synthesis pathway, thereby, causing the reduction of the production of LDs upon infection. To this end, we detected transcription factor 6 (ATF6), the key factor of regulating lipid metabolism along with other related molecules (CHOP and GPR78) and found that curcumin significantly impaired the gene synthesis of ATF6, while CSFV infection promoted ATF6 expression. Therefore, it is confirmed that curcumin inhibited CSFV replication by interfere lipid metabolism. In addition, our subsequent studies found that curcumin played an antiviral role by promoting the innate immune independent of NF-κB signaling pathway. Taken together, our finding highlights that curcumin is a potential candidate drug against CSFV for controlling CSF.
Subject(s)
Classical Swine Fever Virus/drug effects , Curcumin/pharmacology , Gene Expression Regulation , Lipid Metabolism/drug effects , Virus Replication/drug effects , Animals , Cell Line , Host-Pathogen Interactions , Immunity, Innate/drug effects , Immunity, Innate/genetics , Lipid Metabolism/genetics , Signal Transduction , Swine , Virus Internalization/drug effectsABSTRACT
Classical swine fever virus (CSFV), a member of the genus Pestivirus of the family Flaviviridae, relies on host machinery to complete its life cycle. Previous studies have shown a close connection between virus infection and fatty acid biosynthesis, mainly regulated by fatty acid synthase (FASN). However, the molecular action of how FASN participates in CSFV replication remains to be elucidated. In this study, two chemical inhibitors of the fatty acid synthesis pathway [5-(tetradecyloxy)-2-furoic acid (TOFA) and tetrahydro-4-methylene-2R-octyl-5-oxo-3S-furancarboxylic acid (C75)] significantly impaired the late stage of viral propagation, suggesting CSFV replication required fatty acid synthesis. We next found that CSFV infection stimulated the expression of FASN, whereas knockdown of FASN inhibited CSFV replication. Furthermore, confocal microscopy showed that FASN participated in the formation of replication complex (RC), which was associated with the endoplasmic reticulum (ER). Interestingly, CSFV NS4B interacted with FASN and promoted overexpression of FASN, which is regulated by functional Rab18. Moreover, we found that FASN regulated the formation of lipid droplets (LDs) upon CSFV infection, promoting virus proliferation. Taken together, our work provides mechanistic insight into the role of FASN in the viral life of CSFV, and it highlights the potential antiviral target for the development of therapeutics against pestiviruses. IMPORTANCE Classical swine fever, caused by classical swine fever virus (CSFV), is one of the notifiable diseases by the World Organization for Animal Health (OIE) and causes significant financial losses to the pig industry globally. CSFV, like other (+)-strand RNA viruses, requires lipid and sterol biosynthesis for efficient replication. However, the role of lipid metabolism in CSFV replication remains unknown. Here, we found that fatty acid synthase (FASN) was involved in viral propagation. Moreover, FASN is recruited to CSFV replication sites in the endoplasmic reticulum (ER) and interacts with NS4B to regulate CSFV replication that requires Rab18. Furthermore, we speculated that lipid droplet (LD) biosynthesis, indirectly regulated by FASN, ultimately promotes CSFV replication. Our results highlight a critical role for de novo fatty acid synthesis in CSFV infection, which might help control this devastating virus.
Subject(s)
4-Butyrolactone/analogs & derivatives , Classical Swine Fever Virus/physiology , Classical Swine Fever/virology , Fatty Acid Synthases/antagonists & inhibitors , Viral Nonstructural Proteins/metabolism , Virus Replication , rab GTP-Binding Proteins/metabolism , 4-Butyrolactone/pharmacology , Animals , Classical Swine Fever/enzymology , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/virology , Fatty Acid Synthases/metabolism , Host-Pathogen Interactions , Swine , Viral Nonstructural Proteins/genetics , rab GTP-Binding Proteins/geneticsABSTRACT
Cytoskeleton, as a ubiquitous structure in the cells, plays an important role in the process of virus entry, replication, and survival. However, the action mechanism of cytoskeleton in the invasion of Pestivirus into host cells remains unclear. In this study, we systematically dissected the key roles of the main cytoskeleton components, microfilaments and microtubules in the endocytosis of porcine Pestivirus, Classical swine fever virus (CSFV). We observed the dynamic changes of actin filaments in CSFV entry. Confocal microscopy showed that CSFV invasion induced the dissolution and aggregation of stress fibers, resulting in the formation of lamellipodia and filopodia. Chemical inhibitors and RNA interference were used to find that the dynamic changes of actin were caused by EGFR-PI3K/MAPK-RhoA/Rac1/Cdc42-cofilin signaling pathway, which regulates the microfilaments to help CSFV entry. Furthermore, co-localization of the microfilaments with clathrin and Rab5 (early endosome), as well as microtubules with Rab7 (late endosome) and Lamp1 (lysosome) revealed that microfilaments were activated and rearranged to help CSFV trafficking to early endosome after endocytosis. Subsequently, recruitment of microtubules by CSFV also assisted membrane fusion of the virions from late endosome to lysosome with the help of a molecular motor, dynein. Unexpectedly, vimentin, which is an intermediate filament, had no effect on CSFV entry. Taken together, our findings comprehensively revealed the molecular mechanisms of cytoskeletal components that regulated CSFV endocytosis and facilitated further understanding of Pestivirus entry, which would be conducive to explore antiviral molecules to control classical swine fever.IMPORTANCEEndocytosis, an essential biological process mediating cellular internalization events, is often exploited by pathogens for their entry into target cells. Previously, we have reported different mechanisms of CSFV endocytosis into the porcine epithelial cells (PK-15) and macrophages (3D4/21); however, the details of microfilaments/microtubules mediated virus migration within the host cells remained to be elucidated. In this study, we found that CSFV infection induced rearrangement of actin filaments regulated by cofilin through EGFR-PI3K/MAPK-RhoA/Rac1/Cdc42 pathway. Furthermore, we found that CSFV particles were trafficked along actin filaments in early and late endosomes, and through microtubules in lysosomes after entry. Here, we provide for the first time a comprehensive description of the cytoskeleton that facilitates entry and intracellular transport of highly pathogenic swine virus. Results from this study will greatly contribute to the understanding of virus-induced early and complex changes in host cells that are important in CSFV pathogenesis.
ABSTRACT
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a highly contagious disease of swine with high morbidity and mortality that negatively affects the pig industry worldwide, in particular in China. Soon after the endocytosis of CSFV, the virus makes full use of the components of host cells to complete its life cycle. The endocytosis sorting complex required for transport (ESCRT) system is a central molecular machine for membrane protein sorting and scission in eukaryotic cells that plays an essential role in many physiological metabolic processes, including invasion and egress of envelope viruses. However, the molecular mechanism that ESCRT uses to regulate the replication of CSFV is unknown. In this study, we demonstrated that the ESCRT-I complex Tsg101 protein participates in clathrin-mediated endocytosis of CSFV and is also involved in CSFV trafficking. Tsg101 assists the virus in entering the host cell through the late endosome (Rab7 and Rab9) and finally reaching the lysosome (Lamp-1). Interestingly, Tsg101 is also involved in the viral replication process by interacting with nonstructural proteins 4B and 5B of CSFV. Finally, confocal microscopy showed that the replication complex of Tsg101 and double-stranded RNA (dsRNA) or NS4B and NS5B protein was close to the endoplasmic reticulum (ER), not the Golgi, in the cytoplasm. Collectively, our finding highlights that Tsg101 regulates the process of CSFV entry and replication, indicating that the ESCRT plays an important role in the life cycle of CSFV. Thus, ESCRT molecules could serve as therapeutic targets to combat CSFV infection.IMPORTANCE CSF, caused by CSFV, is a World Organization for Animal Health (OIE) notifiable disease and causes significant financial losses to the pig industry globally. The ESCRT machinery plays an important regulatory role in several members of the genera Flavivirus and Hepacivirus within the family Flaviviridae, such as hepatitis C virus, Japanese encephalitis virus, and dengue virus. Previous reports have shown that assembling and budding of these viruses require ESCRT. However, the role of ESCRT in Pestivirus infection remains to be elucidated. We determined the molecular mechanisms of the regulation of CSFV infection by the major subunit Tsg101 of ESCRT-I. Interestingly, Tsg101 plays an essential regulatory role in both clathrin-mediated endocytosis and genome replication of CSFV. Overall, the results of this study provide further insights into the molecular function of ESCRT-I complex protein Tsg101 during CSFV infection, which may serve as a molecular target for pestivirus inhibitors.
Subject(s)
Classical Swine Fever Virus/physiology , DNA-Binding Proteins/metabolism , Endosomal Sorting Complexes Required for Transport/metabolism , Transcription Factors/metabolism , Virus Internalization , Virus Replication , Animals , Cell Line , Classical Swine Fever/metabolism , Classical Swine Fever/virology , DNA-Binding Proteins/genetics , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/virology , Endosomal Sorting Complexes Required for Transport/genetics , Endosomes/metabolism , Endosomes/virology , Host-Pathogen Interactions , Lysosomes/metabolism , Lysosomes/virology , RNA, Viral/metabolism , Swine , Transcription Factors/genetics , Viral Nonstructural Proteins/metabolism , Viral Replication Compartments/metabolismABSTRACT
The interleukin-18 subfamily belongs to the interleukin-1 family and plays an important role in modulating innate and adaptive immune responses. Dysregulation of IL-18 has been implicated in or correlated with numerous diseases, including inflammatory diseases, autoimmune disorders, and cancer. Thus, blockade of IL-18 signaling may offer therapeutic benefits in many pathological settings. Here, we report the development of synthetic human antibodies that target human IL-18Rß and block IL-18-mediated IFN-γ secretion by inhibiting NF-κB and MAPK dependent pathways. The crystal structure of a potent antagonist antibody in complex with IL-18Rß revealed inhibition through an unexpected allosteric mechanism. Our findings offer a novel means for therapeutic intervention in the IL-18 pathway and may provide a new strategy for targeting cytokine receptors.
Subject(s)
Interleukin-18/chemistry , Interleukin-18/metabolism , Enzyme-Linked Immunosorbent Assay , HEK293 Cells , Humans , Interferon-gamma/metabolism , Interleukin-18/immunology , NF-kappa B/metabolism , Protein Structure, Secondary , Signal TransductionABSTRACT
Duck Tembusu virus (DTMUV), a pathogenic member of the Flavivirus family, was first discovered in the coastal provinces of South-Eastern China in 2010. Many previous reports have clearly shown that some Flaviviruses utilize several endocytic pathways to enter the host cells, however, the detailed mechanism of DTMUV entry into BHK-21 cells, which is usually employed to produce commercial veterinary vaccines for DTMUV, as well as of other Flaviviruses by serial passages, is still unknown. In this study, DTMUV entry into BHK-21 cells was found to be inhibited by noncytotoxic concentrations of the agents chloroquine, NH4Cl, and Bafilomycin A1, which blocked the acidification of the endosomes. Inactivation of virions by acid pretreatment is a hallmark of viruses that utilize a low-pH-mediated entry pathway. Exposure of DTMUV virions to pH 5.0 in the absence of host cell membranes decreased entry into cells by 65%. Furthermore, DTMUV infection was significantly decreased by chlorpromazine treatment, or by knockdown of the clathrin heavy chain (CHC) through RNA interference, which suggested that DTMUV entry depends on clathrin. Taken together, these findings highlight that a low endosomal pH is an important route of entry for DTMUV.
Subject(s)
Ducks/virology , Endosomes/metabolism , Flavivirus Infections/veterinary , Flavivirus/physiology , Poultry Diseases/virology , Animals , Clathrin/metabolism , Flavivirus/genetics , Flavivirus Infections/virology , RNA Interference , Virus InternalizationABSTRACT
The level of cholesterol in host cells has been demonstrated to affect viral infection. Our previous studies showed that cholesterol-rich membrane rafts mediated the entry of classical swine fever virus (CSFV) into PK-15 or 3D4/21 cells, but the role of cholesterol post entry was still not clear. In this study, we found that CSFV replication before fusion was affected when the cholesterol trafficking in infected cells was disrupted using a cholesterol transport inhibitor, U18666A. Our data showed that U18666A affected both the fusion and replication steps in the life cycle of the virus, but not its binding and entry steps. The subsequent experiments confirmed that niemann-pick C1 (NPC1), a lysosomal membrane protein that helps cholesterol to leave the lysosome, was affected by U18666A, which led to the accumulation of cholesterol in lysosomes and inhibition of CSFV replication. Imipramine, a cationic hydrophobic amine similar to U18666A, also inhibited CSFV replication via similar mechanism. Surprisingly, the antiviral effect of U18666A was restored by the histone deacetylase inhibitor (HDACi), Vorinostat, which suggested that HDACi reverted the dysfunction of NPC1, and intra-cellular cholesterol accumulation disappeared and CSFV replicability resumed. Together, these data indicated that CSFV transformed from early endosome and late endosome into lysosome after endocytosis for further replication and that U18666A was a potential drug candidate for anti-pestivirus treatment.
Subject(s)
Androstenes/pharmacology , Antiviral Agents/pharmacology , Cholesterol/metabolism , Classical Swine Fever Virus/drug effects , Virus Replication/drug effects , Animals , Biological Transport/drug effects , SwineABSTRACT
In recent years, biological nanomedicine-based biomaterials have an extreme attention for biomedical uses, herein we examined a novel kind advance of photoluminescent Graphene quandum dots encapsulated mesoporous nanoparticles (GND@MSNs) encapsulated by well-known anticancer drugs Doxorubicin (DOX) and Cyclosporin (CsA) for lung carcinoma. Electron microscopic technique exhibit the nanostructure and spherical morphology of GND@MSNs+DOX+CsA with mean size ≈110â¯nm. Moreover, Dynamic Light Scattering (DLS) exposed that blended GND@MSNs+DOX+CsA nanoparticles were highly stable with extremely negatively charged nanoparticles. Raman investigation was done on the all naturally dynamic nanoparticles containing shed graphene to survey the blend condition of the graphene inside the silica mesoporous nanoparticles. GND@MSNs+DOX+CsA provided an outstanding anti-cancer efficiency against the lung cancer cell lines (i.e., A549 and HEL-299). MTT assay monitored that GND@MSNs, GND@MSNs+DOX and GND@MSNs+DOX+CsA have a robust toxicity behaviour on the A549 and HEL-299 model lung cancer cell lines. Additionally, investigation of the cell death was found on AO-EB, Hoechst 33452 staining and flowcytometry techniques. Furthermore, the DNA damage were confirmed by cell cycle arrest and comet assay. Hence, we suggesting that these GND@MSNs+DOX+CsA could be applied as auspicious drug vesicles for novel lung cancer therapeutic potential and new openings to solve the complexity of lung cancer in the care of cancer patients.