CCCP inhibits DPV infection in DEF cells by attenuating DPV manipulated ROS, apoptosis, and mitochondrial stability.

Duck plague virus (DPV) is extremely infectious and lethal, so antiviral drugs are urgently needed. Our previous study shows that DPV infection with duck embryo fibroblast (DEF) induces reactive oxygen species (ROS) changes and promotes apoptosis. In this study, we tested the antiviral effect of the carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a common mitochondrial autophagy inducer. Our results demonstrated a dose-dependent anti-DPV effect of CCCP, CCCP-treatment blocked the intercellular transmission of DPV after infection, and we also proved that CCCP could have an antiviral effect up to 48 hpi. The addition of CCCP reversed the DPV-induced ROS changes, CCCP can inhibit virus-induced apoptosis; meanwhile, CCCP can affect mitochondrial fusion and activate mitophagy to inhibit DPV. In conclusion, CCCP can be an effective antiviral candidate against DPV.

Long-term efficacy of a recombinant hepatitis E vaccine in adults: 10-year results from a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Hepatitis E virus (HEV) is a frequently overlooked causative agent of acute hepatitis. Evaluating the long-term durability of hepatitis E vaccine efficacy holds crucial importance. METHODS: This study was an extension to a randomised, double-blind, placebo-controlled, phase-3 clinical trial of the hepatitis E vaccine conducted in Dontai County, Jiangsu, China. Participants were recruited from 11 townships in Dongtai County. In the initial trial, a total of 112 604 healthy adults aged 16-65 years were enrolled, stratified according to age and sex, and randomly assigned in a 1:1 ratio to receive three doses of hepatitis E vaccine or placebo intramuscularly at month 0, month 1, and month 6. A sensitive hepatitis E surveillance system including 205 clinical sentinels, covering the entire study region, was established and maintained for 10 years after vaccination. The primary outcome was the per-protocol efficacy of hepatitis E virus vaccine to prevent confirmed hepatitis E occurring at least 30 days after administration of the third dose. Throughout the study, the participants, site investigators, and laboratory staff remained blinded to the treatment assignments. This study is registered with ClinicalTrials.gov (NCT01014845). FINDINGS: During the 10-year study period from Aug 22, 2007, to Oct 31, 2017, 90 people with hepatitis E were identified; 13 in the vaccine group (0·2 per 10 000 person-years) and 77 in the placebo group (1·4 per 10 000 person-years), corresponding to a vaccine efficacy of 83·1% (95% CI 69·4-91·4) in the modified intention-to-treat analysis and 86·6% (73·0 to 94·1) in the per-protocol analysis. In the subsets of participants assessed for immunogenicity persistence, of those who were seronegative at baseline and received three doses of hepatitis E vaccine, 254 (87·3%) of 291 vaccinees in Qindong at the 8·5-year mark and 1270 (73·0%) of 1740 vaccinees in Anfeng at the 7·5-year mark maintained detectable concentrations of antibodies. INTERPRETATION: Immunisation with this hepatitis E vaccine offers durable protection against hepatitis E for up to 10 years, with vaccine-induced antibodies against HEV persisting for at least 8·5 years. FUNDING: National Natural Science Foundation of China, Fujian Provincial Natural Science Foundation, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, and the Fundamental Research Funds for the Central Universities.

L-Arginine-Loaded Gold Nanocages Ameliorate Myocardial Ischemia/Reperfusion Injury by Promoting Nitric Oxide Production and Maintaining Mitochondrial Function.

Cardiovascular disease is the leading cause of death worldwide. Reperfusion therapy is vital to patient survival after a heart attack but can cause myocardial ischemia/reperfusion injury (MI/RI). Nitric oxide (NO) can ameliorate MI/RI and is a key molecule for drug development. However, reactive oxygen species (ROS) can easily oxidize NO to peroxynitrite, which causes secondary cardiomyocyte damage. Herein, L-arginine-loaded selenium-coated gold nanocages (AAS) are designed, synthesized, and modified with PCM (WLSEAGPVVTVRALRGTGSW) to obtain AASP, which targets cardiomyocytes, exhibits increased cellular uptake, and improves photoacoustic imaging in vitro and in vivo. AASP significantly inhibits oxygen glucose deprivation/reoxygenation (OGD/R)-induced H9C2 cell cytotoxicity and apoptosis. Mechanistic investigation revealed that AASP improves mitochondrial membrane potential (MMP), restores ATP synthase activity, blocks ROS generation, and prevents NO oxidation, and NO blocks ROS release by regulating the closing of the mitochondrial permeability transition pore (mPTP). AASP administration in vivo improves myocardial function, inhibits myocardial apoptosis and fibrosis, and ultimately attenuates MI/RI in rats by maintaining mitochondrial function and regulating NO signaling. AASP shows good safety and biocompatibility in vivo. This findings confirm the rational design of AASP, which can provide effective treatment for MI/RI.

Antibody response and safety of inactivated SARS-CoV-2 vaccines in chronic hepatitis B patients with and without cirrhosis.

Background: The immune response and safety of inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among patients with chronic hepatitis B (CHB), especially those with cirrhosis, are not clear. Therefore, this study was conducted to evaluate the efficacy and safety of inactivated SARS-CoV-2 vaccines among CHB patients with and without cirrhosis. Patients and methods: A total of 643 CHB patients who received two doses of inactivated SARS-CoV-2 vaccines (BBIBP-CorV and CoronaVac) were enrolled. Serum samples were collected and tested for SARS-CoV-2 S-receptor-binding domain (S-RBD) immunoglobulin G (IgG) at enrollment. Data on adverse events (AEs) within 7 days after the second dose were obtained using a questionnaire. Results: A total of 416 non-cirrhotic and 227 cirrhotic patients were included in the analysis. Cirrhotic patients had lower antibody titers than non-cirrhotic patients after adjusting for age, sex, and time interval (2.45 vs. 2.60 ng/ml, p = 0.034). Furthermore, the study revealed that cirrhotic patients demonstrated a slower rate of seropositivity increase, with the highest rate being recorded at week 4 and reaching 94.7%. On the other hand, among non-cirrhotic patients, the seropositivity rate peak was observed at week 2 and reached 96.0%. In addition, cirrhotic patients displayed a more rapid decline in the seropositivity rate, dropping to 54.5% after ≥16 weeks, while non-cirrhotic patients exhibited a decrease to 67.2% after the same time period. The overall incidence of AEs was low (18.4%), and all AEs were mild and self-limiting. In addition, 16.0% of participants had mild liver function abnormalities, and half of them returned to normality within the next 6 months without additional therapy. The participants who experienced liver function abnormalities showed a higher seropositivity rate and antibody titer than those who did not (91.6% vs. 79.5%, p = 0.005; 2.73 vs. 2.41 ng/ml, p < 0.001). Conclusion: Cirrhotic CHB patients had lower antibody titers to inactivated SARS-CoV-2 vaccines than non-cirrhotic patients. The vaccines were generally well tolerated in both non-cirrhotic and cirrhotic CHB patient groups. Patients with abnormal liver function may have a better antibody response than those without.

The mechanism and therapy of aortic aneurysms.

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.

Gut microbiome and metabolites, the future direction of diagnosis and treatment of atherosclerosis?

Over the past few decades, the treatment of atherosclerotic cardiovascular disease has mainly been through an LDL lowering strategy and treatments targeting other traditional risk factors for atherosclerosis, which has significantly reduced cardiovascular mortality. However, the overall benefit of targeting these risk factors has stagnated, and the discovery of new therapeutic targets for atherosclerosis remains a challenge. Accumulating evidence from clinical and animal experiments has revealed that the gut microbiome play a significant role in human health and disease, including cardiovascular diseases. The gut microbiome contribute to host health and disease through microbial composition and function. The gut microbiome function like an endocrine organ by generating bioactive metabolites that can impact atherosclerosis. In this review, we describe two gut microbial metabolites/pathways by which the gut affects atherosclerotic cardiovascular disease. On the one hand, we discuss the effects of trimethylamine oxide (TMAO), bile acids and aromatic amino acid metabolites on the development of atherosclerosis, and the protective effects of beneficial metabolites short chain amino acids and polyamines on atherosclerosis. On the other hand, we discuss novel therapeutic strategies for directly targeting gut microbial metabolites to improve cardiovascular outcomes. Reducing gut-derived TMAO levels and interfering with the bile acid receptor farnesoid X receptor (FXR) are new therapeutic strategies for atherosclerotic disease. Enzymes and receptors in gut microbiota metabolic pathways are potential new drug targets. We need solid insight into these underlying mechanisms to pave the way for therapeutic strategies targeting gut microbial metabolites/pathways for atherosclerotic cardiovascular disease.

HDL and Sepsis.

Sepsis has been recognized as a global health burden in the year 2017 for its high morbidity and mortality. HDL, a cholesterol transporter, also plays vital role in inflammation besides its typical role in reverse cholesterol transportation. In septic patients, HDL levels dropped significantly. HDL exerts a variety of protective effects in the pathophysiology of sepsis including acting on pathogens, inhibiting macrophage inflammatory reaction, and modulating endothelial function in sepsis. Studies have shown that rHDL or apoA-I mimetic peptides could be therapeutic potentials in sepsis. HDL has caused increasing concern as a potential therapeutic agent.

HDL and Kidney Diseases.

Serum lipid profiles, as well as HDL can be altered in patients with kidney diseases. There are various types of kidney diseases, including nephrotic syndrome and chronic kidney disease. In patients with nephrotic syndrome, plasma levels of HDL cholesterol and ApoA-I were within or below the normal limits. The HDL cholesterol: total cholesterol ratio decreased compared to healthy individuals. In patients with chronic kidney disease (CKD), reverse cholesterol transport function of HDL is impaired, and CKD also affects the composition and function of HDL. Cardiovascular disease (CVD) is the severe complication of CKD. Furthermore, HDL might also be a potential target for the prevention of cardiovascular complications associated with CKD.

H3K9 acetylation modification and TLR9 immune regulation mechanism in patients after anti-HBV treatment.

To improve the curative effect of anti-hepatitis B virus (HBV) drugs, methods such as thymosin and entecavir combination have become a focus of clinical investigation. The aim of this retrospective experimental study was to explore the potential mechanism of action of thymosin a1 (Ta1) combined with entecavir in the treatment of HBV infection. A total of 28 patients with chronic hepatitis B, 29 patients treated with thymosin a1 and entecavir combination, and 15 healthy individuals were enrolled in this study. RT-qPCR was conducted to evaluate the mRNA levels of TLR9 in peripheral blood mononuclear cells (PBMCs). The serum level of TLR9 protein was analyzed by ELISA. The binding of TLR9 gene to the protein H3K9Ac in PBMCs was assessed by chromatin immunoprecipitation, and serum inflammatory factors were detected by Luminex technology. The expression levels of TLR9 mRNA and serum TLR9 protein in patients with HBV infection were significantly lower than those in subjects in the control group before treatment but increased after treatment with the Ta1 and entecavir combination. Moreover, the acetylation protein H3K9Ac was significantly bound to the promoter region of the TLR9 gene in patients with HBV infection treated with the Ta1 and entecavir combination compared to that in patients with HBV infection without treatment. Furthermore, the expression levels of interleukin 6 (IL-6), interleukin 12 (IL-12), interferon gamma, and necrosis factor alpha in patients with HBV infection after the combination treatment were slightly decreased compared to those in patients with HBV infection without treatment. In conclusion, the histone acetylation modification of TLR9 was significantly improved in patients with HBV infection after treatment with the Ta1 and entecavir combination, which elevated the expression of TLR9 at the mRNA and protein levels and further regulated the expression of IL-6, IL-12, and other cytokines.

Anxa1 in smooth muscle cells protects against acute aortic dissection.

AIMS: Acute aortic dissection (AAD) is a life-threatening disease with high morbidity and mortality. Previous studies have showed that vascular smooth muscle cell (VSMC) phenotype switching modulates vascular function and AAD progression. However, whether an endogenous signalling system that protects AAD progression exists remains unknown. Our aim is to investigate the role of Anxa1 in VSMC phenotype switching and the pathogenesis of AAD. METHODS AND RESULTS: We first assessed Anxa1 expression levels by immunohistochemical staining in control aorta and AAD tissue from mice. A strong increase of Anxa1 expression was seen in the mouse AAD tissues. In line with these findings, micro-CT scan results indicated that Anxa1 plays a role in the development of AAD in our murine model, with systemic deficiency of Anxa1 markedly progressing AAD. Conversely, administration of Anxa1 mimetic peptide, Ac2-26, rescued the AAD phenotype in Anxa1-/- mice. Transcriptomic studies revealed a novel role for Anxa1 in VSMC phenotype switching, with Anxa1 deficiency triggering the synthetic phenotype of VSMCs via down-regulation of the JunB/MYL9 pathway. The resultant VSMC synthetic phenotype rendered elevated inflammation and enhanced matrix metalloproteinases (MMPs) production, leading to augmented elastin degradation. VSMC-restricted deficiency of Anxa1 in mice phenocopied VSMC phenotype switching and the consequent exacerbation of AAD. Finally, our studies in human AAD aortic specimens recapitulated key findings in murine AAD, specifically that the decrease of Anxa1 is associated with VSMC phenotype switch, heightened inflammation, and enhanced MMP production in human aortas. CONCLUSIONS: Our findings demonstrated that Anxa1 is a novel endogenous defender that prevents AAD by inhibiting VSMC phenotype switching, suggesting that Anxa1 signalling may be a potential target for AAD pharmacological therapy.

Prognostic Value of Elevated Levels of Plasma N-Acetylneuraminic Acid in Patients With Heart Failure.

BACKGROUND: Cardiac sialylation is involved in a variety of physiological processes in the heart. Altered sialylation has been implicated in heart failure (HF) mice. However, its role in patients with HF is unclear, and the potential effect of modulation of cardiac sialylation is worth exploring. METHODS: We first assessed the association between plasma N-acetylneuraminic acid levels and the incidence of adverse cardiovascular events in patients with HF over a median follow-up period of 2 years. Next, immunoblot analysis and lectin histochemistry were performed in cardiac tissue to determine the expression levels of neuraminidases and the extent of cardiac desialylation. Finally, the therapeutic impact of a neuraminidase inhibitor was evaluated in animal models of HF. RESULTS: Among 1699 patients with HF, 464 (27%) died of cardiovascular-related deaths or underwent heart transplantation. We found that the elevated plasma N-acetylneuraminic acid level was independently associated with a higher risk of incident cardiovascular death and heart transplantation (third tertile adjusted hazard ratio, 2.11 [95% CI, 1.67-2.66], P<0.001). In addition, in cardiac tissues from patients with HF, neuraminidase expression was upregulated, accompanied by desialylation. Treatment with oseltamivir, a neuraminidase inhibitor, in HF mice infused with isoproterenol and angiotensin II significantly inhibited desialylation and ameliorated cardiac dysfunction. CONCLUSIONS: This study uncovered a significant association between elevated plasma N-acetylneuraminic acid level and an increased risk of a poor clinical outcome in patients with HF. Our data support the notion that desialylation represents an important contributor to the progression of HF, and neuraminidase inhibition may be a potential therapeutic strategy for HF.

Self-Training With Progressive Representation Enhancement for Unsupervised Cross-Domain Person Re-Identification.

In recent years, person re-identification (re-ID) has achieved relatively good performance, benefiting from the revival of deep neural networks. However, due to the existence of domain bias which refers to the different data distributions between two domains, it remains challenging to directly deploy a model trained on a labeled source domain to a target domain only with unlabeled data available. In this paper, a Self-Training with Progressive Representation Enhancement (PREST) framework, which comprises a multi-scale self-training method and a view-invariant representation learning module, is proposed to promote re-ID performance on the target domain in an unsupervised manner. More specifically, multi-scale representations, including the global body and local parts of pedestrian images, are utilized to obtain pseudo-labels. Then, some images are selected according to the pseudo-labels to create a new dataset for supervising the fine-tuning process, which is operated iteratively to progressively promote the performance. Furthermore, to mitigate the influence of different styles among sub-domains, in cases where a single sub-domain is captured by one camera, a classifier with a gradient reverse layer is first employed to learn view-invariant representation for pedestrian images with the same identity taken by different cameras; this can further enhance the reliability of the predicted labels and improve the cross-domain re-ID performance. Extensive experiments on three large-scale re-ID datasets demonstrate that our framework achieves significantly better performance than existing approaches.

A potent neutralizing nanobody against SARS-CoV-2 with inhaled delivery potential.

The coronavirus disease 2019 (COVID-19) pandemic has become a serious burden on global public health. Although therapeutic drugs against COVID-19 have been used in many countries, their efficacy is still limited. We here reported nanobody (Nb) phage display libraries derived from four camels immunized with the SARS-CoV-2 spike receptor-binding domain (RBD), from which 381 Nbs were identified to recognize SARS-CoV-2-RBD. Furthermore, seven Nbs were shown to block interaction of human angiotensin-converting enzyme 2 (ACE2) with SARS-CoV-2-RBD variants and two Nbs blocked the interaction of human ACE2 with bat-SL-CoV-WIV1-RBD and SARS-CoV-1-RBD. Among these candidates, Nb11-59 exhibited the highest activity against authentic SARS-CoV-2 with 50% neutralizing dose (ND50) of 0.55 µg/ml. Nb11-59 can be produced on large scale in Pichia pastoris, with 20 g/L titer and 99.36% purity. It also showed good stability profile, and nebulization did not impact its stability. Overall, Nb11-59 might be a promising prophylactic and therapeutic molecule against COVID-19, especially through inhalation delivery.

Zidovudine-Based Treatments Inhibit the Glycosylation of ADAM17 and Reduce CD163 Shedding From Monocytes.

BACKGROUND: sCD163, a biomarker of monocyte-macrophage activation, has been identified as a predictor of all-cause mortality in treated HIV-infected individuals. Nevertheless, little is known about whether different antiretroviral drugs differentially regulate sCD163 levels and monocyte activation. METHODS: A total of 123 patients receiving zidovudine (ZDV)-based (n = 55) or tenofovir disoproxil fumarate (TDF)-based (n = 68) antiretroviral regimens were enrolled, and their viral loads, CD4 counts, as well as plasma sCD163 and sCD14 levels were quantified. Twenty-eight (14 in each group) patients donated additional blood samples for flow cytometry and gene expression analyses using purified monocytes. THP-1 cultures were also used to investigate the effect of ZDV on ADAM17, which is responsible for CD163 shedding. RESULTS: As compared to the TDF-treated group, the ZDV-treated group had lower plasma sCD163 levels and higher CD163 expression on CD14++CD16 monocytes. Five metabolic-inflammatory genes exhibited significantly different expression levels between purified monocytes of the ZDV and TDF groups (IL-6, 2.90-fold lower in ZDV group, P < 0.001; iNOS, 1.81-fold higher; CX3CR1, 1.72-fold lower; MIP-1ß, 1.10-fold lower; and PPARγ-1, 1.36-fold higher, P < 0.05). Moreover, we show that ZDV treatment increases the surface expression of CD163 in cultured THP-1 cells, accompanied by the inhibition of glycosylation and surface expression of ADAM17. CONCLUSIONS: Compared with TDF treatment, ZDV treatment causes lower plasma sCD163 levels, probably by inhibiting the glycosylation of ADAM17 and CD163 shedding. Our results show that ZDV functions as an ADAM17 inhibitor in vivo and extend our understanding of its immune-modulatory effects and adverse effects.

Prediction of the Ebola Virus Infection Related Human Genes Using Protein-Protein Interaction Network.

BACKGROUND: Ebola hemorrhagic fever (EHF) is caused by Ebola virus (EBOV). It is reported that human could be infected by EBOV with a high fatality rate. However, association factors between EBOV and host still tend to be ambiguous. OBJECTIVE: According to the "guilt by association" (GBA) principle, proteins interacting with each other are very likely to function similarly or the same. Based on this assumption, we tried to obtain EBOV infection-related human genes in a protein-protein interaction network using Dijkstra algorithm. CONCLUSION: We hope it could contribute to the discovery of novel effective treatments. Finally, 15 genes were selected as potential EBOV infection-related human genes.

Ablation of the Sox11 Gene Results in Clefting of the Secondary Palate Resembling the Pierre Robin Sequence.

Mouse gene inactivation has shown that the transcription factor Sox11 is required for mouse palatogenesis. However, whether Sox11 is primarily involved in the regulation of palatogenesis still remains elusive. In this study, we explored the role ofSox11in palatogenesis by analyzing the developmental mechanism in cleft palate formation in mutants deficient in Sox11. Sox11 is expressed both in the developing palatal shelf and in the surrounding structures, including the mandible. We found that cleft palate occurs only in the mutant in which Sox11is directly deleted. As in the wild type, the palatal shelves in the Sox11 mutant undergo outgrowth in a downward direction and exhibit potential for fusion and elevation. However, mutant palatal shelves encounter clefting, which is associated with a malpositioned tongue that results in physical obstruction of palatal shelf elevation at embryonic day 14.5 (E14.5). We found that loss of Sox11led to reduced cell proliferation in the developing mandibular mesenchyme via Cyclin D1, leading to mandibular hypoplasia, which blocks tongue descent. Extensive analyses of gene expression inSox11 deficiency identified FGF9 as a potential candidate target of Sox11 in the modulation of cell proliferation both in the mandible and the palatal shelf between E12.5 and E13.5. Finally we show, using in vitro assays, that Sox11 directly regulates the expression of Fgf9 and that application of FGF9 protein to Sox11-deficient palatal shelves restores the rate of BrdU incorporation. Taken together, the palate defects presented in the Sox11 loss mutant mimic the clefting in the Pierre Robin sequence in humans.

Modulation of Chloride Channel Functions by the Plant Lignan Compounds Kobusin and Eudesmin.

Plant lignans are diphenolic compounds widely present in vegetables, fruits, and grains. These compounds have been demonstrated to have protective effect against cancer, hypertension and diabetes. In the present study, we showed that two lignan compounds, kobusin and eudesmin, isolated from Magnoliae Flos, could modulate intestinal chloride transport mediated by cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride channels (CaCCs). The compounds activated CFTR channel function in both FRT cells and in HT-29 cells. The modulating effects of kobusin and eudesmin on the activity of CaCCgie (CaCC expressed in gastrointestinal epithelial cells) were also investigated, and the result showed that both compounds could stimulate CaCCgie-mediated short-circuit currents and the stimulation was synergistic with ATP. In ex vivo studies, both compounds activated CFTR and CaCCgie chloride channel activities in mouse colonic epithelia. Remarkably, the compounds showed inhibitory effects toward ANO1/CaCC-mediated short-circuit currents in ANO1/CaCC-expressing FRT cells, with IC50 values of 100 µM for kobusin and 200 µM for eudesmin. In charcoal transit study, both compounds mildly reduced gastrointestinal motility in mice. Taken together, these results revealed a new kind of activity displayed by the lignan compounds, one that is concerned with the modulation of chloride channel function.

[Polymethoxylated flavonoids activate cystic fibrosis transmembrane conductance regulator chloride channel].

Cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent chloride channel, plays key roles in fluid secretion in serous epithelial cells. Previously, we identified two polymethoxylated flavonoids, 3',4',5,5',6,7-hexamethoxyflavone (HMF) and 5-hydroxy-6,7,3',4'-tetramethoxyflavone (HTF) which could potentiate CFTR chloride channel activities. The present study was aimed to investigate the potentiation effects of HMF and HTF on CFTR Cl(-) channel activities by using a cell-based fluorescence assay and the short circuit Ussing chamber assay. The results of cell-based fluorescence assay showed that both HMF and HTF could dose-dependently potentiate CFTR Cl(-) channel activities in rapid and reversible ways, and the activations could be reversed by the CFTR blocker CFTRinh-172. Notably, HMF showed the highest affinity (EC50 = 2 µmol/L) to CFTR protein among the flavonoid CFTR activators identified so far. The activation of CFTR by HMF or HTF was forskolin (FSK) dependent. Both compounds showed additive effect with FSK and 3-Isobutyl-1-methylx (IBMX) in the activation of CFTR, while had no additive effect with genistein (GEN). In ex vivo studies, HMF and HTF could stimulate transepithelial Cl(-) secretion in rat colonic mucosa and enhance fluid secretion in mouse trachea submucosal glands. These results suggest that HMF and HTF may potentiate CFTR Cl(-) channel activities through both elevation of cAMP level and binding to CFTR protein pathways. The results provide new clues in elucidating structure and activity relationship of flavonoid CFTR activators. HMF might be developed as a new drug in the therapy of CFTR-related diseases such as bronchiectasis and habitual constipation.