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1.
Talanta ; 274: 125973, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38537359

ABSTRACT

Sensitive detection of copper ion (Cu2+), which is of great importance for environmental pollution and human health, is crucial. In this study, we present a highly sensitive method for measuring Cu2+ in an array of femtoliter wells. In brief, magnetic beads (MBs) modified with alkyne groups were bound to the azide groups of biotin-PEG3-azide (bio-PEG-N3) via Cu+-catalyzed click chemistry. Cu+ in the click chemistry reaction was generated by reducing Cu2+ with sodium ascorbate. Following the ligation, the surface of the MBs was modified with biotin, which could be labeled with streptavidin-ß-galactosidase (SßG). The MBs complex was then suspended in ß-galactosidase substrate fluorescein-di-ß-d-galactopyranoside (FDG), and loaded into the array of femtoliter wells. The MBs sank into the wells due to gravity, and the resulting fluorescent product, generated from the reaction between SßG on the surface of the MBs and FDG, was confined within the wells. The number of fluorescent wells increased with higher Cu2+ concentrations. The bright-field and fluorescent images of the wells were acquired using an inverted fluorescent microscope. The detection limit of this assay for Cu2+ was 1 nM without signal amplification, which was 103 times lower than that of traditional fluorescence detection assays.


Subject(s)
Azides , Click Chemistry , Copper , Copper/chemistry , Copper/analysis , Azides/chemistry , Limit of Detection , Biotin/chemistry , Polyethylene Glycols/chemistry , Streptavidin/chemistry , beta-Galactosidase/metabolism , beta-Galactosidase/chemistry , beta-Galactosidase/analysis
2.
J Pharm Pharmacol ; 2023 Nov 25.
Article in English | MEDLINE | ID: mdl-38007392

ABSTRACT

OBJECTIVES: Inflammatory cytokine secretion and gut microbiota dysbiosis play crucial roles in ulcerative colitis. In this research, the protective effects of peimisine on colitis mice were investigated. METHODS: The protective effects were evaluated by the disease activity index, colonic length, hematoxylin-eosin, and AB/PAS Staining. The protective mechanisms were analyzed by ELISA, Western-blot, immunohistochemistry staining, immunofluorescence staining, and 16S rRNA gene analysis. KEY FINDINGS: The results showed that peimisine treatment could reduce the disease activity index, prevent colonic shortening, and alleviate colon tissue damage. Peimisine treatment also decreased the levels of MCP-1, IL-1ß, IL-6, IFN-γ, TNF-α and affected macrophage polarization and Th17/Treg cell balance by downregulating the expression of jak1/2, p-jak1/2, stat1/3, and p-stat1/3. Moreover, peimisine treatment significantly increased the abundances of beneficial microbes (e.g. Ruminococcaceae UCG-014 and Lachnospiraceae_NK4A136_group) and decreased the abundances of harmful microbes (e.g. Bacteroides and Escherichia). CONCLUSIONS: Peimisine can ameliorate colitis by inhibiting Jak-Stat signaling pathway, reversing gut microbiota alterations, suppressing macrophage M1 polarization, maintaining the Th17/Treg cell balance, and reducing sustained inflammatory cytokines-related inflammatory injury.

3.
Front Cell Infect Microbiol ; 13: 1117230, 2023.
Article in English | MEDLINE | ID: mdl-37124037

ABSTRACT

Introduction: Human adenovirus type 7 (HAdv-7) infection is the main cause of upper respiratory tract infection, bronchitis and pneumonia in children. At present, there are no anti- adenovirus drugs or preventive vaccines in the market. Therefore, it is necessary to develop a safe and effective anti-adenovirus type 7 vaccine. Methods: In this study, In this study, we used the baculovirus-insect cell expression system to design a recombinant subunit vaccine expressing adenovirus type 7 hexon protein (rBV-hexon) to induce high-level humoral and cellular immune responses. To evaluate the effectiveness of the vaccine, we first detected the expression of molecular markers on the surface of antigen presenting cells and the secretion of proinflammatory cytokines in vitro. We then measured the levels of neutralizing antibodies and T cell activation in vivo. Results: The results showed that the rBV-hexon recombinant subunit vaccine could promote DC maturation and improve its antigen uptake capability, including the TLR4/NF-κB pathway which upregulated the expression of MHCI, CD80, CD86 and cytokines. The vaccine also triggered a strong neutralizing antibody and cellular immune response, and activated T lymphocytes. Discussion: Therefore, the recombinant subunit vaccine rBV-hexon promoted promotes humoral and cellular immune responses, thereby has the potential to become a vaccine against HAdv-7.


Subject(s)
Adenovirus Vaccines , Dendritic Cells , Humans , Adenovirus Vaccines/immunology , Adenoviruses, Human , Antibodies, Neutralizing , Antibodies, Viral , Cytokines , NF-kappa B , Toll-Like Receptor 4 , Vaccines, Synthetic , Animals
4.
Antiviral Res ; 212: 105559, 2023 04.
Article in English | MEDLINE | ID: mdl-36813181

ABSTRACT

Human adenovirus type 7 (HAdv-7) infection is the main cause of upper respiratory tract infection, bronchitis and pneumonia in children. At present, there are no anti-adenovirus drugs or preventive vaccines in the market. Therefore, it is necessary to develop a safe and effective anti-adenovirus type 7 vaccine. In this study, we designed a virus-like particle vaccine expressing the epitopes of hexon and penton of adenovirus type 7 with hepatitis B core protein (HBc) as the vector to induce high-level humoral and cellular immune responses. To evaluate the effectiveness of the vaccine, we first detected the expression of molecular markers on the surface of antigen presenting cells and the secretion of proinflammatory cytokines in vitro. We then measured the levels of neutralizing antibodies and T cell activation in vivo. The results showed that the HAdv-7 virus-like particles (VLPs) recombinant subunit vaccine could activate the innate immune response, including the TLR4/NF-κB pathway which upregulated the expression of MHC II, CD80, CD86, CD40 and cytokines. The vaccine also triggered a strong neutralizing antibody and cellular immune response and activated T lymphocytes. Therefore, the HAdv-7 VLPs promoted humoral and cellular immune responses, thereby potentially enhancing protection against HAdv-7 infection.


Subject(s)
Adenovirus Vaccines , Adenoviruses, Human , Vaccines, Virus-Like Particle , Child , Humans , NF-kappa B , Adenoviruses, Human/genetics , Toll-Like Receptor 4 , Antibodies, Neutralizing , Adenoviridae/genetics , Cytokines , Dendritic Cells
5.
Virol J ; 20(1): 18, 2023 01 31.
Article in English | MEDLINE | ID: mdl-36721152

ABSTRACT

Coronavirus disease 2019 is a global pandemic caused by SARS-CoV-2. The emergence of its variant strains has posed a considerable challenge to clinical treatment. Therefore, drugs capable of inhibiting SARS-CoV-2 infection, regardless of virus variations, are in urgently need. Our results showed that the endosomal acidification inhibitor, Bafilomycin A1 (Baf-A1), had an inhibitory effect on the viral RNA synthesis of SARS-CoV-2, and its Beta and Delta variants at the concentration of 500 nM. Moreover, the human lung xenograft mouse model was used to investigate the anti-SARS-CoV-2 effect of Baf-A1. It was found that Baf-A1 significantly inhibited SARS-CoV-2 replication in the human lung xenografts by in situ hybridization and RT-PCR assays. Histopathological examination showed that Baf-A1 alleviated SARS-CoV-2-induced diffuse inflammatory infiltration of granulocytes and macrophages and alveolar endothelial cell death in human lung xenografts. In addition, immunohistochemistry analysis indicated that Baf-A1 decreased inflammatory exudation and infiltration in SARS-CoV-2-infected human lung xenografts. Therefore, Baf-A1 may be a candidate drug for SARS-CoV-2 treatment.


Subject(s)
COVID-19 , Humans , Animals , Mice , Heterografts , SARS-CoV-2 , Alveolar Epithelial Cells , Disease Models, Animal
6.
Anal Chem ; 95(2): 714-719, 2023 01 17.
Article in English | MEDLINE | ID: mdl-36576396

ABSTRACT

In this study, we described an easy-to-perform nano-luciferase (nLuc) sensor for the rapid detection of 3-chymotrypsin-like protease (3CLpro) encoded by SARS-CoV-2. The technology is based on the cleavage reaction of recombinant-nLuc via 3CLpro. The nLuc-based assay is a general, one-step method and is naturally specific in detection. The stability, sensitivity, detection range, and response time are fully characterized. The application of 3CLpro detection in artificial and human saliva as well as antiviral drug screening demonstrates that the method can quantify 3CLpro with high sensitivity in one step. With its unique features, the nLuc-based assay may find broad applications in the auxiliary diagnosis of SARS-CoV-2, as well as other types of coronavirus infection.


Subject(s)
COVID-19 , Coronavirus 3C Proteases , SARS-CoV-2 , Humans , Antiviral Agents , COVID-19/diagnosis , SARS-CoV-2/enzymology
7.
Article in English | MEDLINE | ID: mdl-36284386

ABSTRACT

Pyruvate kinase M2 (PKM2) is a key enzyme in aerobic glycolysis, and which plays an important role in tumor energy metabolism and tumor growth. Ad-apoptin, a recombinant oncolytic adenovirus, that can stably express apoptin in tumor cells and selectively causes cell death in tumor cells. The relationship between the anti-tumor function of apoptin, including apoptosis and autophagy activation, and energy metabolism of tumor cells has not been clarified. In this study, we used the A549 lung cancer cell line to analyze the mechanism of PKM2 involvement apoptin-mediated cell death in tumor cells. PKM2 expression in lung cancer cells was detected by Western blot and qRT-PCR. In the PKM2 knockdown and over-expression experiments, A549 lung cancer cells were treated with Ad-apoptin, and cell viability was determined by the CCK-8 assay and crystal violet staining. Glycolysis was investigated using glucose consumption and lactate production experiments. Moreover, the effects of Ad-apoptin on autophagy and apoptosis were analyzed by immunofluorescence using the Annexin v-mCherry staining and by western blot for c-PARP, p62 and LC3-II proteins. Immunoprecipitation analysis was used to investigate the interaction between apoptin and PKM2. In addition, following PKM2 knockdown and overexpression, the expression levels of p-AMPK, p-mTOR, p-ULK1, and p-4E-BP1 proteins in Ad-apoptin treated tumor cells, were analyzed by western blot to investigate the mechanism of apoptin effect on the energy metabolism of tumor cells. The in vivo antitumor mechanism of apoptin was analyzed by xenograft tumor inhibition experiment in nude mice and immunohistochemistry of tumors' tissue. As a result, apoptin could target PKM2, inhibit glycolysis and cell proliferation in A549 cells, and promote autophagy and apoptosis in A549 cells by regulating the PKM2/AMPK/mTOR pathway. This study confirmed the necessary role of Ad-apoptin in energy metabolism of A549 cells.

8.
Int J Biol Sci ; 18(2): 717-730, 2022.
Article in English | MEDLINE | ID: mdl-35002520

ABSTRACT

Apoptin is a small molecular weight protein encoded by the VP3 gene of chicken anemia virus (CAV). It can induce apoptosis of tumor cells and play anti-tumorigenic functions. In this study, we identified a time-dependent inhibitory role of apoptin on the viability of HCT116 cells. We also demonstrated that apoptin induces pyroptosis through cleaved caspase 3, and with a concomitant cleavage of gasdermin E (GSDME) rather than GSDMD. GSDME knockdown switched the apoptin-induced cell death from pyroptosis to apoptosis in vitro. Furthermore, we demonstrated that the effect of apoptin on GSDME-dependent pyroptosis could be mitigated by caspase-3 and caspase-9 siRNA knockdown. Additionally, apoptin enhanced the intracellular reactive oxygen species (ROS), causing aggregation of the mitochondrial membrane protein Tom20. Moreover, bax and cytochrome c were released to the activating caspase-9, eventually triggering pyroptosis. Therefore, GSDME mediates the apoptin-induced pyroptosis through the mitochondrial apoptotic pathway. Finally, using nude mice xenografted with HCT116 cells, we found that apoptin induces pyroptosis and significantly inhibits tumor growth. Based on this mechanism, apoptin may provide a new strategy for colorectal cancer therapy.


Subject(s)
Caspase 3/metabolism , Caspase 9/metabolism , Colorectal Neoplasms/metabolism , Pore Forming Cytotoxic Proteins/metabolism , Pyroptosis , Animals , Caspase 3/genetics , Caspase 9/genetics , Colorectal Neoplasms/pathology , Cytochromes c/metabolism , Female , HCT116 Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Xenograft Model Antitumor Assays , bcl-2-Associated X Protein/metabolism
9.
Invest New Drugs ; 40(2): 274-289, 2022 04.
Article in English | MEDLINE | ID: mdl-34981275

ABSTRACT

Background One of the main challenges in the clinical treatment of lung cancer is resistance to chemotherapeutic drugs. P-glycoprotein (P-gp)-mediated drug resistance is the main obstacle to successfully implementing microtubule-targeted tumor chemotherapy. Purpose In this study, we explored the effect of Ad-hTERTp-E1a-Apoptin (Ad-VT) on drug-resistant cell lines and the molecular mechanism by which Ad-VT combined with chemotherapy affects drug-resistant cells and parental cells. Methods In vitro, cell proliferation, colony formation, resistance index (RI), apoptosis and autophagy assays were performed. Protein expression was analyzed by Western blotting. Finally, a xenograft tumor model in nude mice was used to detect tumor growth and evaluate histological characteristics. Results Our results showed that Ad-VT had an obvious killing effect on A549, A549/GEM and A549/Paclitaxel cancer cells, and the sensitivity of drug-resistant cell lines to Ad-VT was significantly higher than that of parental A549 cells. Compared with A549 cells, A549/GEM and A549/Paclitaxel cells had higher autophagy levels and higher viral replication ability. Ad-VT decreased the levels of p-PI3k, p-Akt and p-mTOR and the expression of P-gp. In vivo, Ad-VT combined with chemotherapy can effectively inhibit the growth of chemotherapy-resistant tumors and prolong the survival of mice. Conclusions Thus, the combination of Ad-VT and chemotherapeutic drugs will be a promising strategy to overcome chemoresistance.


Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Adenocarcinoma of Lung/drug therapy , Animals , Apoptosis , Cell Line, Tumor , Cell Proliferation , Deoxycytidine/analogs & derivatives , Drug Resistance, Neoplasm , Humans , Lung Neoplasms/pathology , Mice , Mice, Nude , Paclitaxel/pharmacology , Paclitaxel/therapeutic use , Xenograft Model Antitumor Assays , Gemcitabine
10.
Fitoterapia ; 156: 105071, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34743931

ABSTRACT

Adhesion of monocytes to endothelial cells is an important initiating step in atherogenesis. One of the most abundant flavonoids in the diet, quercetin has been reported to inhibit monocyte adhesion to endothelial cells. However, it is poorly absorbed in the upper gastrointestinal tract during oral intake but rather is metabolized by the intestinal microbiota into various phenolic acids. Since the biological properties of the microbial metabolites of quercetin remain largely unknown, herein, we investigated how the microbial metabolite of quercetin, 3-(3-hydroxyphenyl)propionic acid (3HPPA) impact monocyte adhesion to endothelial cells. Direct treatment with 3HPPA for 24 h was not cytotoxic to human aortic endothelial cells (HAECs). Cotreatment with 3HPPA inhibited tumor necrosis factor α (TNFα)-induced adhesion of THP-1 monocytes to HAECs, and suppressed the upregulation of cell adhesion molecule E-selectin but not intercellular adhesion molecule 1 or vascular cell adhesion molecule 1. Furthermore, 3HPPA was found to inhibit TNFα-induced nuclear translocation and phosphorylation of the p65 subunit of nuclear factor κB (NF-κB). We conclude that 3HPPA mitigates the adhesion of monocytes to endothelial cells by suppressing the expression of the cell adhesion molecule E-selectin in HAECs via inhibition of the NF-κB pathway, providing additional evidence for the health benefits of dietary flavonoids and their microbial metabolites as therapeutic agents in atherosclerosis.


Subject(s)
Atherosclerosis/drug therapy , Cell Adhesion/drug effects , Endothelial Cells/drug effects , Monocytes/drug effects , Propionates/metabolism , Quercetin/metabolism , THP-1 Cells/drug effects , Cells, Cultured/drug effects , Humans
11.
Talanta ; 236: 122847, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34635237

ABSTRACT

Nucleocapsid protein (N protein) is the most abundant protein in SARS-CoV2 and is highly conserved, and there are no homologous proteins in the human body, making it an ideal biomarker for the early diagnosis of SARS-CoV2. However, early detection of clinical specimens for SARS-CoV2 remains a challenge due to false-negative results with viral RNA and host antibodies based testing. In this manuscript, a microfluidic chip with femtoliter-sized wells was fabricated for the sensitive digital detection of N protein. Briefly, ß-galactosidase (ß-Gal)-linked antibody/N protein/aptamer immunocomplexes were formed on magnetic beads (MBs). Afterwards, the MBs and ß-Gal substrate fluorescein-di-ß-d-galactopyranoside (FDG) were injected into the chip together. Each well of the chip would only hold one MB as confined by the diameter of the wells. The MBs in the wells were sealed by fluorocarbon oil, which confines the fluorescent (FL) product generated from the reaction between ß-Gal and FDG in the individual femtoliter-sized well and creates a locally high concentration of the FL product. The FL images of the wells were acquired using a conventional inverted FL microscope. The number of FL wells with MBs (FL wells number) and the number of wells with MBs (MBs wells number) were counted, respectively. The percentage of FL wells was calculated by dividing (FL wells number) by (MBs wells number). The higher the percentage of FL wells, the higher the N protein concentration. The detection limit of this digital method for N protein was 33.28 pg/mL, which was 300 times lower than traditional double-antibody sandwich based enzyme-linked immunosorbent assay (ELISA).


Subject(s)
Immunoassay/methods , Nucleocapsid Proteins , SARS-CoV-2 , Antibodies , COVID-19/diagnosis , Humans , Nucleocapsid Proteins/isolation & purification , RNA, Viral
12.
Adv Mater ; 33(49): e2102562, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34643001

ABSTRACT

Optoelectronic science and 2D nanomaterial technologies are currently at the forefront of multidisciplinary research and have numerous applications in electronics and photonics. The unique energy and optically induced interfacial electron transfer in these nanomaterials, enabled by their relative band alignment characteristics, can provide important therapeutic modalities for healthcare. Given that nano-heterostructures can facilitate photoinduced electron-hole separation and enhance generation of reactive oxygen species (ROS), 2D nano-heterostructure-based photosensitizers can provide a major advancement in photodynamic therapy (PDT), to overcome the current limitations in hypoxic tumor microenvironments. Herein, a bismuthene/bismuth oxide (Bi/BiOx)-based lateral nano-heterostructure synthesized using a regioselective oxidation process is introduced, which, upon irradiation at 660 nm, effectively generates 1 O2 under normoxia but produces cytotoxic •OH and H2 under hypoxia, which synergistically enhances PDT. Furthermore, this Bi/BiOx nano-heterostructure is biocompatible and biodegradable, and, with the surface molecular engineering used here, it improves tumor tissue penetration and increases cellular uptake during in vitro and in vivo experiments, yielding excellent oxygen-independent tumor ablation with 660 nm irradiation, when compared with traditional PDT agents.


Subject(s)
Neoplasms , Photochemotherapy , Bismuth , Humans , Hypoxia , Neoplasms/drug therapy , Oxygen , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Tumor Microenvironment
13.
J Virol ; 95(24): e0153721, 2021 11 23.
Article in English | MEDLINE | ID: mdl-34550769

ABSTRACT

Autophagy is thought to be involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, how SARS-CoV-2 interferes with the autophagic pathway and whether autophagy contributes to virus infection in vivo is unclear. In this study, we identified SARS-CoV-2-triggered autophagy in animal models, including the long-tailed or crab-eating macaque (Macaca fascicularis), human angiotensin-converting enzyme 2 (hACE2) transgenic mice, and xenografted human lung tissues. In Vero E6 and Huh-7 cells, SARS-CoV-2 induces autophagosome formation, accompanied by consistent autophagic events, including inhibition of the Akt-mTOR pathway and activation of the ULK-1-Atg13 and VPS34-VPS15-Beclin1 complexes, but it blocks autophagosome-lysosome fusion. Modulation of autophagic elements, including the VPS34 complex and Atg14, but not Atg5, inhibits SARS-CoV-2 replication. Moreover, this study represents the first to demonstrate that the mouse bearing xenografted human lung tissue is a suitable model for SARS-CoV-2 infection and that autophagy inhibition suppresses SARS-CoV-2 replication and ameliorates virus-associated pneumonia in human lung tissues. We also observed a critical role of autophagy in SARS-CoV-2 infection in an hACE2 transgenic mouse model. This study, therefore, gives insights into the mechanisms by which SARS-CoV-2 manipulates autophagosome formation, and we suggest that autophagy-inhibiting agents might be useful as therapeutic agents against SARS-CoV-2 infection. IMPORTANCE Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic with limited therapeutics. Insights into the virus-host interactions contribute substantially to the development of anti-SARS-CoV-2 therapeutics. The novelty of this study is the use of a new animal model: mice xenografted with human lung tissues. Using a combination of in vitro and in vivo studies, we have obtained experimental evidence that induction of autophagy contributes to SARS-CoV-2 infection and improves our understanding of potential therapeutic targets for SARS-CoV-2.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Autophagy , COVID-19 Drug Treatment , COVID-19/virology , Lung/virology , SARS-CoV-2 , Virus Replication , Angiotensin-Converting Enzyme 2/metabolism , Animals , Autophagosomes , Cell Line, Tumor , Chlorocebus aethiops , Humans , Lung/pathology , Macaca , Male , Mice , Mice, Transgenic , Pneumonia, Viral/drug therapy , RNA, Small Interfering/metabolism , Vero Cells
14.
Invest New Drugs ; 39(4): 949-960, 2021 08.
Article in English | MEDLINE | ID: mdl-33534026

ABSTRACT

As a potential cancer therapy, we developed a recombinant adenovirus named Ad-VT, which was designed to express the apoptosis-inducing gene (apoptin) and selectively replicate in cancer cells via E1a manipulation. However, how it performs in bladder cancer remains unclear. We examined the antitumor efficacy of Ad-VT in bladder cancers using CCK-8 assays and xenograft models. Autophagy levels were evaluated by western blotting, MDC staining, and RFP-GFP-LC3 aggregates' analyses. Here, we report the selective replication and antitumor efficacy (viability inhibition and apoptosis induction) of Ad-VT in bladder cancer cells. Using xenograft tumor models, we demonstrate that its effects are tumor specific resulting in the inhibition of tumor growth and improvement of the survival of mice models. Most Importantly, Ad-VT induced a complete autophagy flux leading to autophagic cancer cell death through a signaling pathway involving AMPK, raptor and mTOR. Finally, we suggest that treatment combination of Ad-VT and rapamycin results in a synergistic improvement of tumor control and survival compared to monotherapy. This study suggests that Ad-VT can induce selective autophagic antitumor activities in bladder cancer through the AMPK-Raptor-mTOR pathway, which can be further improved by rapamycin.


Subject(s)
Adenoviridae/genetics , Autophagy/genetics , Oncolytic Virotherapy/methods , Urinary Bladder Neoplasms/therapy , AMP-Activated Protein Kinases/metabolism , Animals , Capsid Proteins/genetics , Cell Line, Tumor , Female , HEK293 Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Regulatory-Associated Protein of mTOR/metabolism , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Urinary Bladder Neoplasms/genetics , Xenograft Model Antitumor Assays
15.
Virol J ; 18(1): 46, 2021 02 27.
Article in English | MEDLINE | ID: mdl-33639976

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2 and broke out as a global pandemic in late 2019. The acidic pH environment of endosomes is believed to be essential for SARS-CoV-2 to be able to enter cells and begin replication. However, the clinical use of endosomal acidification inhibitors, typically chloroquine, has been controversial with this respect. METHODS: In this study, RT-qPCR method was used to detect the SARS-CoV-2N gene to evaluate viral replication. The CCK-8 assay was also used to evaluate the cytotoxic effect of SARS-CoV-2. In situ hybridization was used to examine the distribution of the SARS-CoV-2 gene in lung tissues. Hematoxylin and eosin staining was also used to evaluate virus-associated pathological changes in lung tissues. RESULTS: In this study, analysis showed that endosomal acidification inhibitors, including chloroquine, bafilomycin A1 and NH4CL, significantly reduced the viral yields of SARS-CoV-2 in Vero E6, Huh-7 and 293T-ACE2 cells. Chloroquine and bafilomycin A1 also improved the viability and proliferation of Vero E6 cells after SARS-CoV-2 infection. Moreover, in the hACE2 transgenic mice model of SARS-CoV-2 infection, chloroquine and bafilomycin A1 reduced viral replication in lung tissues and alleviated viral pneumonia with reduced inflammatory exudation and infiltration in peribronchiolar and perivascular tissues, as well as improved structures of alveolar septum and pulmonary alveoli. CONCLUSIONS: Our research investigated the antiviral effects of endosomal acidification inhibitors against SARS-CoV-2 in several infection models and provides an experimental basis for further mechanistic studies and drug development.


Subject(s)
Antiviral Agents/pharmacology , COVID-19 Drug Treatment , COVID-19/virology , Endosomes/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Virus Replication/drug effects , Ammonium Chloride/pharmacology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/metabolism , COVID-19/pathology , Cell Survival/drug effects , Chlorocebus aethiops , Chloroquine/pharmacology , Endosomes/metabolism , Female , HEK293 Cells , Humans , Hydrogen-Ion Concentration , Lung/pathology , Macrolides/pharmacology , Mice , Mice, Transgenic , Random Allocation , SARS-CoV-2/genetics , Vero Cells
16.
Front Microbiol ; 12: 780768, 2021.
Article in English | MEDLINE | ID: mdl-35069483

ABSTRACT

Mitochondria, which is essential for adequate innate immune response, energy metabolism and mitochondria reactive oxygen species (ROS) production, might be in the cross fire of Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and host cell defense. However, little is known about interactions between mitochondria and SARS-CoV-2. We performed fluorescent microscopy and found an enrichment of SARS-CoV-2 replication products double stranded RNA (dsRNA) within mitochondria. The entry process of dsRNA might be mediated by Tom20 as observed by reduced mitochondrial localization of SARS-CoV-2 dsRNA in Tom20 knockdown cells. Importantly, decreased mitochondrial localization of dsRNA, as well as mitochondrial membrane stabilizers mdivi-1 and cyclosporin A, inhibited viral load in cells. Next, we detected mitochondrial dysfunction caused by SARS-CoV-2 infection, including mitochondrial membrane depolarization, mitochondrial permeability transition pore opening and increased ROS release. In response to mitochondrial damage, we observed an increase in expression and mitochondrial accumulation of Pink1 and Parkin proteins, as well as Pink-1-mediated recruitment of P62 to mitochondria, suggesting initiated mitophagy for mitochondrial quality control and virus clearance. Nevertheless, we observed that mitophagy was inhibited and stayed in early stage with an unchanged Hsp60 expression post SARS-CoV-2 infection. This might be one of the anti-autophagy strategies of SARS-CoV-2 and we used co-immunoprecipitation to found that SARS-CoV-2 infection inhibited P62 and LC3 binding which plays a critical role in selective envelopment of substrates into autophagosomes. Our results suggest that mitochondria are closely involved in SARS-CoV-2 replication and mitochondrial homeostasis is disrupted by SARS-CoV-2 in the virus-cell confrontation.

17.
RSC Adv ; 11(10): 5320-5324, 2021 Jan 28.
Article in English | MEDLINE | ID: mdl-35423084

ABSTRACT

A novel sensing platform for sensitive detection of copper(ii) ions (Cu2+) in living cells and body fluids was developed by taking advantage of the excellent fluorescence quenching ability of graphdiyne (GDY) and the high specificity of click chemistry for the first time.

18.
Adv Sci (Weinh) ; 7(17): 2000940, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32995123

ABSTRACT

The circulating tumor cell (CTC) count is closely related to cancer recurrence and metastasis. The technology that can in vivo destroy CTCs may bring great benefits to patients, which is an urgent clinical demand. Here, a minimally invasive therapeutic intravenous catheter for in vivo enriching and photothermal killing of CTCs is developed. The surface of catheter is modified with anti-EpCAM antibody and the interior is filled with black phosphorus nanosheets (BPNSs). CTCs in the peripheral blood are captured by the catheter continually with the aid of circulation. The captured CTCs are used for downstream analyses or in vivo eliminated by the near-infrared (NIR) photothermal effect of BPNSs. A capture efficiency of 2.1% is obtained during the 5 min of treatment, and 100% of the captured CTCs are killed by following NIR light irradiation in both an in vitro closed-loop circulation system and an in vivo rabbit model. This cost-effective modality for lowering the CTCs burden can be a good supplement to traditional therapies, which holds great promise as an effective clinical intervention for cancer patients.

19.
Nanoscale ; 12(38): 19939-19952, 2020 Oct 08.
Article in English | MEDLINE | ID: mdl-32991664

ABSTRACT

Tumor vaccines are a promising form of cancer immunotherapy, but difficulties such as neo-antigen identification, activation of immune cells, and tumor infiltration prevent their clinical breakthrough. Interestingly, nanotechnology-based photothermal therapy (PTT) has great potential to overcome these barriers. Previous studies have shown that serum exosomes (hEX) from hyperthermia-treated tumor-bearing mice displayed an array of patient-specific tumor-associated antigens (TAAs), and strong immunoregulatory abilities in promoting dendritic cell (DC) differentiation and maturation. Here, we developed a tumor vaccine (hEX@BP) by encapsulating black phosphorus quantum dots (BPQDs) with exosomes (hEX) against a murine subcutaneous lung cancer model. In comparison with BPQDs alone (BP), hEX@BP demonstrated better long-term PTT performance, greater elevation of tumor temperature and tumor targeting efficacy in vivo. Vaccination with hEX@BP in combination with PTT further demonstrated an outstanding therapeutic efficacy against established lung cancer, and promoted the infiltration of T lymphocytes into the tumor tissue. Our findings demonstrated that hEX@BP might be an innovative cancer photo-nanovaccine that offers effective immuno-PTT against cancers.


Subject(s)
Cancer Vaccines , Exosomes , Nanoparticles , Animals , Dendritic Cells , Humans , Immunotherapy , Mice , Phosphorus
20.
Chem Commun (Camb) ; 54(97): 13718-13721, 2018 Dec 04.
Article in English | MEDLINE | ID: mdl-30452026

ABSTRACT

A novel lateral flow biosensor for rapid detection of Pb2+ was established for the first time based on Pb2+-induced G-quadruplex structure-switching. Semi-quantitative results could be read by reference to a colorimetric card. The whole process only took 15 minutes with a visual detection limit of 25 nM.


Subject(s)
Biosensing Techniques , G-Quadruplexes , Lead/analysis , Ions/analysis
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