ABSTRACT
Objective To evaluate the effect of Aspergillus fumigatus on the expression of tumor necrosis factor-α (TNF-oα) and activation of intracellular signaling molecule p38 mitogen-activated protein kinase (p38MAPK) in a human acute monocytic leukemia cell line THP-1.Methods Cultured THP-1 cells (2 x 105/ml) were divided into 4 groups to be treated with Aspergillus fumigatus suspensions at concentrations of 106 and 107 colony-forming units (CFU)/ml (106-and 107-CFU/ml Aspergillusfumigatus groups),100 mg/L β-glucan (a positive stimulus,β-glucan group),culture medium (blank control group) respectively for 1,3 and 6 hours.Real-time fluorescence-based quantitative PCR (qPCR) was conducted to determine the mRNA expression of TNF-α in the THP-1 cells in the above groups.Some other THP-1 cells were treated with 107 CFU/ml Aspergillusfumigatus suspensions (107-CFU/ml Aspergillusfumigatus group),β-glucan (β-glucan group) and culture medium (blank control group) separately for 24 hours,and enzymelinked immunosorbent assay (ELISA) was performed to detect the level of TNF-α in the culture supernatant of THP-1 cells.Western blot analysis was conducted to detect the levels of p38MAPK and phosphorylated p38MAPK in THP-1 cells after 15-,30-and 60-minute treatment with 107 CFU/ml Aspergillusfumigatus suspensions.After 2-hour incubation with the p38MAPK inhibitor SB203580 (20 μmol/L),some THP-1 cells were additionally treated with 107 CFU/ml Aspergillus fumigatus suspensions,β-glucan and culture medium separately for 6 hours,and those without SB203580 treatment served as the control group.Then,qPCR was performed to measure the mRNA expression of TNF-α in the THP-1 cells in the above groups.Results The mRNA expression of TNF-α significantly differed among the 106-and 107-CFU/ml Aspergillus fumigatus groups,β-glucan group and blank control group (F =110.983,P ＜ 0.001),and significantly increased over time (F =701.680,P ＜ 0.001).After 24-hour treatment with 107 CFU/ml Aspergillus fumigatus suspensions,the TNF-α level(6 236.30 ± 437.12 ng/L)significantly increased compared with the blank control group (132.10 ± 0.61 ng/L,P ＜ 0.01).Thirty minutes after the treatment with 107 CFU/ml Aspergillusfumigatus suspensions,the phosphorylated p38MAPK level significantly increased,but started to decrease at 60 minutes.The mRNA expression of TNF-α was significantly lower in the SB203580-treated Aspergillusfumigatus groups (3.83 ± 0.62) than in the SB203580-untreated Aspergillus fumigatus groups (187.23 ± 21.62).Conclusion After the treatment with Aspergillus fumigatus,human THP-1 cells can activate the signal molecule p38MAPK and secrete TNF-α,suggesting that monocytes may participate in the innate immune response to Aspergillusfumigatus infection.
ABSTRACT
Objective To determine the expression of interleukin-6 (IL-6) in cystic lesions of patients with acne vulgaris,and to evaluate the in vitro effect of Propionibacterium acnes (P.acnes) on the production of IL-6 and activation of p38 mitogen-activated protein kinase (p38MAPK) in the human acute monocytic leukemia cell line THP-1.Methods Real-time fluorescence-based quantitative PCR was performed to determine the mRNA expression of IL-6 in cystic lesions of 6 patients with acne vulgaris,as well as in skin tissues of 6 healthy persons.Some cultured THP-1 cells were divided into 5 groups to be treated with 2 × 106 CFU/ml,2 × 107 CFU/ml and 2 × 108 CFU/ml heat-killed P.acnes suspensions (P.acnes groups),100 μμtg/L lipopolysaccharide (LPS group) and RPMI 1640 medium (control group) respectively.After 1-,3-and 6-hour treatment,real-time fluorescence-based quantitative PCR was conducted to determine the mRNA expression of IL-6 in the above groups.Enzyme-linked immunosorbent assay (ELISA) was performed to detect the level of IL-6 in the culture supernatant of cells in the 2 × 108-CFU/ml P.acnes group,LPS group and control group at 24 hours after the treatment.Western blot analysis was conducted to determine the protein expression of p38MAPK and phosphorylated p38MAPK in the 2 × 108-CFU/ml P.acnes group after 15-,30-and 60-minute treatment,as well as in the LPS group after 30-minute treatment and in the control group.Some other THP-1 cells were divided into 3 groups:2 × 108-CFU/ml P.acnes group treated with 2 × 108 CFU/ml P.acnes suspensions,SB203580 (an inhibitor of p38MAPK) group treated with 20 μmol/L SB203580 for 30 minutes followed by the treatment with 2 × 108 CFU/ml P.acnes suspensions,and control group treated with RPMI 1640 medium alone.After 6-hour treatment,the mRNA expression of IL-6 in the above 3 groups was measured by real-time fluorescencebased quantitative PCR.Results The mRNA expression of IL-6 was significantly higher in the cystic lesions of acne vulgaris than in the normal skin tissues (3.680:±:0.790 vs.1.155 ± 0.250,t =3.047,P ＜0.05).Two-way analysis of variance showed that there were significant difference in the mRNA expression of IL-6 among the 2 × 106-CFU/ml,2 × 107-CFU/ml and 2 × 108-CFU/ml p.acnes groups,LPS group and control group (F =532.3,P ＜ 0.001,v =4),and the mRNA expression of IL-6 significantly differed among different time points (F =526.6,P ＜ 0.001,v =2).There were also significant differences in the IL-6 level in the culture supernatant of cells among the 2 × 108-CFU/ml p.acnes group ([1 618.22 ± 32.23] ng/L),LPS group ([3 212.06 ± 353.00] ng/L) and control group ([147.10 ± 0.53] ng/L;v =2,F =102.35,P ＜0.01).After 15-,30-and 60-minute treatment with 2 × 108 CFU/ml P.acnes suspensions,the protein expression of phosphorylated p38MAPK obviously increased.The mRNA expression of IL-6 in THP-1 cells was significantly lower in the SB203580 group than in the 2 × 108-CFU/ml p.acnes group (t =15.91,P =0.004).Conclusions The mRNA expression of IL-6 evidently increases in the cystic lesions of patients with acne vulgaris.P.acnes can activate the signaling molecule p38MAPK in THP-1 cells,and promote the production of IL-6 by THP-1 cells.
ABSTRACT
Objective To construct a native promoter-regulated Aspergillus fumigatus strain containing red fluorescent protein-labeled calmodulin (CaM-RFP),and to observe the dynamic distribution of calmodulin during the growth of Aspergillus fumigatus.Methods Bilateral flanking sequences of Aspergillus fumigatus calmodulin gene were designed,and plasmids containing the two flanking sequences and mRFP-Aspergillus fumigatus pyrG gene (mRFP-AfpyrG) were amplified separately.The final linear PCR product for transformation was generated from the above three PCR products by fusion PCR.Then,the above linear fragment was transferred into the Aspergillus fumigatus strain by protoplast transformation,so as to construct the CaM-RFP Aspergillus fumigatus strain.The monoclonal colony was picked from the screening medium and subjected to culture.Then,the stablest fluorescent monoxenic strain of Aspergillus fumigatus was selected,and the transformant was verified by PCR.The recombinant strain and wild-type stain were cultured on solid nutrient media separately,and the morphology of these strains was observed by fluorescence microscopy at different time points.Additionally,the above 2 strains were cultured in liquid media separately,and XTT assay was performed to evaluate the growth activity of strains.Microscopy was also conducted to dynamically observe the CaM-RFP Aspergillusfumigatus strain,and analyze the spatial and temporal distribution of calmodulin during the growth and development of Aspergillus fumigatus.Results The fluorescent phenotype and PCR identification results both indicated the successful construction of the CaM-RFP Aspergillus fumigatus strain.The growth activity at 24 hours did not differ between the recombinant strain and wild-type stain (A490:0.689 ± 0.081 vs.0.678 ± 0.054,t =1.32,P ＞0.05),so did the morphology.During the polarized growth of Aspergillus fumigatus,calmodulin was always at the top of the hyphae,germination site of the hyphal branch and the top of new branches.Conclusion Calmodulin may be involved in the regulation of spore germination and polar hyphal growth of Aspergillus fumigatus.