BACKGROUND:Streptococcus pneumoniae(S.pneumoniae)is a common pathogen that causes bacterial pneumonia.However,with increasing bacterial resistance,there is an urgent need to develop new drugs to treat S.pneumoniae inf...BACKGROUND:Streptococcus pneumoniae(S.pneumoniae)is a common pathogen that causes bacterial pneumonia.However,with increasing bacterial resistance,there is an urgent need to develop new drugs to treat S.pneumoniae infections.Nanodefensin with a 14-carbon saturated fatty acid(ND-C14)is a novel nanoantimicrobial peptide designed by modifying myristic acid at the C-terminus of humanα-defensin 5(HD5)via an amide bond.However,it is unclear whether ND-C14 is effective against lung infections caused by S.pneumoniae.METHODS:In vitro,three groups were established,including the control group,and the HD5 and ND-C14 treatment groups.A virtual colony-count assay was used to evaluate the antibacterial activity of HD5 and ND-C14 against S.pneumoniae.The morphological changes of S.pneumoniae treated with HD5 or ND-C14 were observed by scanning electron microscopy.In vivo,mice were divided into sham,vehicle,and ND-C14 treatment groups.Mice in the sham group were treated with 25μL of phosphate-buffered saline(PBS).Mice in the vehicle and ND-C14 treatment groups were treated with intratracheal instillation of 25μL of bacterial suspension with 2×108 CFU/mL(total bacterial count:5×10^(6) CFU),and then the mice were given 25μL PBS or intratracheally injected with 25μL of ND-C14(including 20μg or 50μg),respectively.Survival rates were evaluated in the vehicle and ND-C14 treatment groups.Bacterial burden in the blood and bronchoalveolar lavage fluid were counted.The lung histology of the mice was assessed.A propidium iodide uptake assay was used to clarify the destructive eff ect of ND-C14 against S.pneumoniae.RESULTS:Compared with HD5,ND-C14 had a better bactericidal eff ect against S.pneumoniae because of its stronger ability to destroy the membrane structure of S.pneumoniae in vitro.In vivo,ND-C14 significantly delayed the death time and improved the survival rate of mice infected with S.pneumoniae.ND-C14 reduced bacterial burden and lung tissue injury.Moreover,ND-C14 had a membrane permeation eff ect on S.pneumoniae,and its destructive ability increased with increasing ND-C14 concentration.CONCLUSION:The ND-C14 may improve bactericidal eff ects on S.pneumoniae both in vitro and in vivo.展开更多
AIM: To determine the concentration of α-and β-defensins in gastric juice of patients with various gastroduodenal diseases. METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defe...AIM: To determine the concentration of α-and β-defensins in gastric juice of patients with various gastroduodenal diseases. METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defensins, and human β-defensin (HBD)-1and HBD-2were measured by radioimmunoassay in plasma and gastric juice of 84 subjects, consisting of 54 Helicobacter pylori-infected and 30 uninfected subjects. They included 33 patients with chronic gastritis (CG), 12 with gastric ulcer (GU), 11 with duodenal ulcer (DU), 11 with benign gastric polyp (BGP) and 16 with normal mucosa (N group) on upper endoscopy. Plasma pepsinogen Ⅰ and Ⅱ levels, biomarkers for gastric mucosal inflammation and atrophy, were also measured. RESULTS: Gastric juice HNPs 1-3 levels in patients with CG, GU and BGP were significantly higher than those in patients with DU and N. Gastric juice HBD-2 concentrations in patients with CG and GU were significantly higher than those in the N group, but were significantly lower in DU patients than in GU patients. Gastric juice HBD-1 levels and plasma levels of these peptides were similar in the patient groups. Concentrations of gastric juice HNPs 1-3 and HBD-2 of in H pylori-infected patients were significantly different from those in uninfected subjects. HNPs 1-3 concentrations in gastric juice correlated negatively with plasma pepsinogen I levels and Ⅰ/Ⅱ ratios. HBD-2 levels in gastric juice correlated positively and negatively with plasma pepsinogen Ⅱ concentrations and Ⅰ/Ⅱratios, respectively. CONCLUSION: HNPs 1-3 and HBD-2 levels in gastric juice are diverse among various gastrointestinal diseases, reflecting the inflammatory and atrophic events of the background gastric mucosa affected by H pylori.展开更多
MIA： Human β-defensin （HBD）-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori （H pylon）. We sought to determine HBD-1 and HBD-2 concentrati...MIA： Human β-defensin （HBD）-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori （H pylon）. We sought to determine HBD-1 and HBD-2 concentrations in gastric juice during Hpylori infection. METHODS： HBD-1 and HBD-2 concentrations were measured by radioimmunoassay in plasma and gastric juice of 49 Hpylori-infected and 33 uninfected subjects and before and after anti-H pyloritreatment in,13 patients with Hpylori-associated gastritis. Interleukin （IL）-1β and IL-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay （ELISA）. Histological grades of gastritis were determined using two biopsy specimens taken from the antrum and corpus. Reverse phase high performance liquid chromatography （RP-HPLC） was used to identify HBD-2. RESULTS： HBD-2 concentrations in gastric juice, but not in plasma, were significantly higher in Hpylori-positive than -negative subjects, albeit the post-treatment levels were unchanged. Immunoreactivity for HBD-2 was exclusively identified in Hpylori-infected mucosa by RPHPLC. HBD-2 concentrations in gastric juice correlated with histological degree of neutrophil and mononuclear cell infiltration in the corpus. IL-1β levels correlated with those of IL-8, but not HBD-2. Plasma and gastric juice HBD-1 concentrations were similar in H pylori-infected and uninfected subjects. CONCLUSION： Our results place the β-defensins, especiallyHBD-2, in the front line of innate immune defence. Moreover, HBD-2 may be involved in the pathogenesis of Hpylori-associated gastritis, possibly through its function as immune and inflammatory mediator.展开更多
Periodontal disease is the leading cause of tooth loss,which is also a high-risk factor for other diseases including oral cancer and cardiovascular disease.Periodontitis is one of the most common type of periodontal d...Periodontal disease is the leading cause of tooth loss,which is also a high-risk factor for other diseases including oral cancer and cardiovascular disease.Periodontitis is one of the most common type of periodontal diseases.Interleukin-1β(IL-1β)plays a key role in the pathogenesis of periodontitis.However,the mechanism how IL-1βis produced during periodontitis is still unclear.In the present study,we found that humanβ-defensin 2(hBD2)enhances IL-1βproduction through an LPS-primed human acute monocytic leukemia(THP-1)macrophage model.Inhibition of P2X purinoceptor 7(P2X7)reduced hBD2-enhanced IL-1βproduction.Incubation of LPS-primed THP-1 macrophages with potassium chloride also suppressed hBD2-enhanced IL-1βproduction.Silence of inflammasome adaptor Nod-like receptor family pyrin domain containing 3(NLRP3)led to reduced hBD2-enhanced IL-1βproduction.Likewise,inhibition of caspase-1 also resulted in the decrease of IL-1β.Moreover,an ethidium bromide uptake test indicated that hBD2-activated caspase-1 mediated pyroptotic pore formation.Subsequent lactate dehydrogenase detection and flow cytometric analysis indicated that hBD2 also induced pyroptosis.In brief,these findings illustrated not only the mechanism of hBD2 in enhancing the inflammatory response,but also provided novel therapeutic targets for periodontitis.展开更多
基金supported by the National Natural Science Foundation of China(82072148)Zhejiang Provincial Basic Public Welfare Research Program of Zhejiang Province(LGF21H150002)+1 种基金Zhejiang Medicine and Health Science and Technology Project(2022RC245&2023KY255)Ningbo Municipal Natural Science Foundation(2023J134).
文摘BACKGROUND:Streptococcus pneumoniae(S.pneumoniae)is a common pathogen that causes bacterial pneumonia.However,with increasing bacterial resistance,there is an urgent need to develop new drugs to treat S.pneumoniae infections.Nanodefensin with a 14-carbon saturated fatty acid(ND-C14)is a novel nanoantimicrobial peptide designed by modifying myristic acid at the C-terminus of humanα-defensin 5(HD5)via an amide bond.However,it is unclear whether ND-C14 is effective against lung infections caused by S.pneumoniae.METHODS:In vitro,three groups were established,including the control group,and the HD5 and ND-C14 treatment groups.A virtual colony-count assay was used to evaluate the antibacterial activity of HD5 and ND-C14 against S.pneumoniae.The morphological changes of S.pneumoniae treated with HD5 or ND-C14 were observed by scanning electron microscopy.In vivo,mice were divided into sham,vehicle,and ND-C14 treatment groups.Mice in the sham group were treated with 25μL of phosphate-buffered saline(PBS).Mice in the vehicle and ND-C14 treatment groups were treated with intratracheal instillation of 25μL of bacterial suspension with 2×108 CFU/mL(total bacterial count:5×10^(6) CFU),and then the mice were given 25μL PBS or intratracheally injected with 25μL of ND-C14(including 20μg or 50μg),respectively.Survival rates were evaluated in the vehicle and ND-C14 treatment groups.Bacterial burden in the blood and bronchoalveolar lavage fluid were counted.The lung histology of the mice was assessed.A propidium iodide uptake assay was used to clarify the destructive eff ect of ND-C14 against S.pneumoniae.RESULTS:Compared with HD5,ND-C14 had a better bactericidal eff ect against S.pneumoniae because of its stronger ability to destroy the membrane structure of S.pneumoniae in vitro.In vivo,ND-C14 significantly delayed the death time and improved the survival rate of mice infected with S.pneumoniae.ND-C14 reduced bacterial burden and lung tissue injury.Moreover,ND-C14 had a membrane permeation eff ect on S.pneumoniae,and its destructive ability increased with increasing ND-C14 concentration.CONCLUSION:The ND-C14 may improve bactericidal eff ects on S.pneumoniae both in vitro and in vivo.
文摘AIM: To determine the concentration of α-and β-defensins in gastric juice of patients with various gastroduodenal diseases. METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defensins, and human β-defensin (HBD)-1and HBD-2were measured by radioimmunoassay in plasma and gastric juice of 84 subjects, consisting of 54 Helicobacter pylori-infected and 30 uninfected subjects. They included 33 patients with chronic gastritis (CG), 12 with gastric ulcer (GU), 11 with duodenal ulcer (DU), 11 with benign gastric polyp (BGP) and 16 with normal mucosa (N group) on upper endoscopy. Plasma pepsinogen Ⅰ and Ⅱ levels, biomarkers for gastric mucosal inflammation and atrophy, were also measured. RESULTS: Gastric juice HNPs 1-3 levels in patients with CG, GU and BGP were significantly higher than those in patients with DU and N. Gastric juice HBD-2 concentrations in patients with CG and GU were significantly higher than those in the N group, but were significantly lower in DU patients than in GU patients. Gastric juice HBD-1 levels and plasma levels of these peptides were similar in the patient groups. Concentrations of gastric juice HNPs 1-3 and HBD-2 of in H pylori-infected patients were significantly different from those in uninfected subjects. HNPs 1-3 concentrations in gastric juice correlated negatively with plasma pepsinogen I levels and Ⅰ/Ⅱ ratios. HBD-2 levels in gastric juice correlated positively and negatively with plasma pepsinogen Ⅱ concentrations and Ⅰ/Ⅱratios, respectively. CONCLUSION: HNPs 1-3 and HBD-2 levels in gastric juice are diverse among various gastrointestinal diseases, reflecting the inflammatory and atrophic events of the background gastric mucosa affected by H pylori.
文摘MIA： Human β-defensin （HBD）-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori （H pylon）. We sought to determine HBD-1 and HBD-2 concentrations in gastric juice during Hpylori infection. METHODS： HBD-1 and HBD-2 concentrations were measured by radioimmunoassay in plasma and gastric juice of 49 Hpylori-infected and 33 uninfected subjects and before and after anti-H pyloritreatment in,13 patients with Hpylori-associated gastritis. Interleukin （IL）-1β and IL-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay （ELISA）. Histological grades of gastritis were determined using two biopsy specimens taken from the antrum and corpus. Reverse phase high performance liquid chromatography （RP-HPLC） was used to identify HBD-2. RESULTS： HBD-2 concentrations in gastric juice, but not in plasma, were significantly higher in Hpylori-positive than -negative subjects, albeit the post-treatment levels were unchanged. Immunoreactivity for HBD-2 was exclusively identified in Hpylori-infected mucosa by RPHPLC. HBD-2 concentrations in gastric juice correlated with histological degree of neutrophil and mononuclear cell infiltration in the corpus. IL-1β levels correlated with those of IL-8, but not HBD-2. Plasma and gastric juice HBD-1 concentrations were similar in H pylori-infected and uninfected subjects. CONCLUSION： Our results place the β-defensins, especiallyHBD-2, in the front line of innate immune defence. Moreover, HBD-2 may be involved in the pathogenesis of Hpylori-associated gastritis, possibly through its function as immune and inflammatory mediator.
基金This work was supported by National Natural Science Foundation of China(NSFC)(81500871)Natural Science Foundation of Guangdong Province(2016A030310214).
文摘Periodontal disease is the leading cause of tooth loss,which is also a high-risk factor for other diseases including oral cancer and cardiovascular disease.Periodontitis is one of the most common type of periodontal diseases.Interleukin-1β(IL-1β)plays a key role in the pathogenesis of periodontitis.However,the mechanism how IL-1βis produced during periodontitis is still unclear.In the present study,we found that humanβ-defensin 2(hBD2)enhances IL-1βproduction through an LPS-primed human acute monocytic leukemia(THP-1)macrophage model.Inhibition of P2X purinoceptor 7(P2X7)reduced hBD2-enhanced IL-1βproduction.Incubation of LPS-primed THP-1 macrophages with potassium chloride also suppressed hBD2-enhanced IL-1βproduction.Silence of inflammasome adaptor Nod-like receptor family pyrin domain containing 3(NLRP3)led to reduced hBD2-enhanced IL-1βproduction.Likewise,inhibition of caspase-1 also resulted in the decrease of IL-1β.Moreover,an ethidium bromide uptake test indicated that hBD2-activated caspase-1 mediated pyroptotic pore formation.Subsequent lactate dehydrogenase detection and flow cytometric analysis indicated that hBD2 also induced pyroptosis.In brief,these findings illustrated not only the mechanism of hBD2 in enhancing the inflammatory response,but also provided novel therapeutic targets for periodontitis.
