1.Effect and underlying mechanism of resveratol on porcine primary preadipocyte apoptosis.
Zhao ZHANG ; Yang YANG ; Weijun PANG ; Chao SUN ; Gongshe YANG
Chinese Journal of Biotechnology 2010;26(8):1042-1049
We demonstrated the effect of resveratrol on porcine primary preadipocytes apoptosis, to study the intracellular molecular mechanism. Porcine primary preadipocyte was treated with different concentration of resveratrol (0 micromol/L, 50 micromol/L, 100 micromol/L, 200 micromol/L, 400 micromol/L). We used optical microscope and fluorescence microscope to observe morphological changes during apoptosis after Hoechst 33258 Fluorescent dyes staining; and RT-PCR and Western blotting to measure the expression of apoptosis-associated gene sirt1, caspase-3, bcl-2, bax, p53, NF-kappaB. Primary preadipocyte apoptosis was apparent, accompanied by reduced cell volume, chromatin condensation, and nuclear shrinkage. Compared to the control and low concentration group, high dose group (200 micromol/L) significantly increased the ratio of primary preadipocyte apoptosis. The expression of sirt1, caspase-3, and bax was up-regulated markedly in response to resveratrol; in contrast, apoptotic inhibitor bcl-2, p53, NF-kappaB down-regulated. We further proved fact that resveratrol can specifically promote the activity of sirt1; moreover, activated sirt1 modulates the activity of caspase-3 and bcl-2 family, involving in transcriptional regulation of p53 and NF-kappaB through antagonizing factor-induced acetylation. Taken together, our data established resveratrol as new regulator in porcine primary preadipocyte apoptosis via activating the expression of sirt1, modulating activity of apoptotic-associated factor.
Adipocytes
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cytology
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Adipogenesis
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Animals
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Antioxidants
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pharmacology
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Apoptosis
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drug effects
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Caspase 3
;
metabolism
;
Cells, Cultured
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Sirtuin 1
;
metabolism
;
Stilbenes
;
pharmacology
;
Swine
2.Apoptosis of Megakaryocytic Leukemia Cell Line Meg-01 Induced by TSP-1 Via CD36/Caspase-3.
Hui-Min KONG ; Wei-Qing SU ; Yi LUO ; Hui GE ; Liang LI ; Mo YANG ; Qian-Li JIANG
Journal of Experimental Hematology 2022;30(4):998-1004
OBJECTIVE:
To investigate the effect of thrombospondin-1 (TSP-1) on apoptosis of human megakaryocytic leukemia cell line Meg-01 and its possible mechanism.
METHODS:
The expression of CD36 antigen in Meg-01 cells was detected by flow cytometry and immunocytochemistry. Meg-01 cells were cultured for 48 hours with TSP-1 and CD36 antibody FA6-152 at different concentrations. The early apoptosis and activity of caspase-3 were detected by flow cytometry. The effect of TSP-1 on the growth and differentiation of megakaryocytes was investigated by cell counting and CFU-MK culture.
RESULTS:
The flow cytometry and immunocytochemistry showed that CD36 antigen was expressed on the surface of Meg-01 cells. TSP-1 (5 μg/ml) inhibited the growth of Meg-01 cells, but had unobvious effect on M-07e cells. After addition of CD36 antibody FA6-152 (5, 10, and 25 μg/ml), the inhibition effect of TSP-1 was significantly reduced. TSP-1 (2.5, 5, and 7.5 μg/ml) increased the positive expression of Annexin V (P<0.01) and caspase-3 activity (P<0.01), which indicated that TSP-1 had a significant effect on inducing apoptosis. After addition of CD36 antibody FA6-152 (25 μg/ml), the apoptosis induced by TSP-1 in Meg-01 cells was significantly reduced. TSP-1 (5, 10, and 25 μg/ml) could significantly inhibit the formation of CFU-MK in mouse bone marrow cells, while β-TG could not. CD36 antibody FA6-152 (25 μg/ml) could significantly reduce the inhibition of TSP-1 on CFU-MK.
CONCLUSION
TSP-1 may induce apoptosis of megakaryocytic leukemia cell line Meg-01 cells via CD36/caspase-3, which provides a potential new drug development and treatment target for clinical treatment of megakaryocytic leukemia.
Animals
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Apoptosis
;
CD36 Antigens/metabolism*
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Caspase 3/metabolism*
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Cell Line
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Humans
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Leukemia, Megakaryoblastic, Acute
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Mice
;
Thrombospondin 1/pharmacology*
3.The role and mechanism of autophagy in lipopolysaccharide-induced inflammatory response of A549 cells.
Jia SHI ; Hui-Xian TAO ; Yan GUO ; Yun-Su ZOU ; Mu-Zi WANG ; Zhi-Tao LU ; Yi-Fang DING ; Wei-Dong XU ; Xiao-Guang ZHOU
Chinese Journal of Contemporary Pediatrics 2022;24(10):1161-1170
OBJECTIVES:
To study the role and mechanism of autophagy in lipopolysaccharide (LPS)-induced inflammatory response of human alveolar epithelial A549 cells.
METHODS:
A549 cells were stimulated with LPS to establish a cell model of inflammatory response, and were then grouped (n=3 each) by concentration (0, 1, 5, and 10 μg/mL) and time (0, 4, 8, 12, and 24 hours). The A549 cells were treated with autophagy inhibitor 3-methyladenine (3-MA) to be divided into four groups (n=3 each): control, LPS, 3-MA, and 3-MA+LPS. The A549 cells were treated with autophagy agonist rapamycin (RAPA) to be divided into four groups (n=3 each): control, LPS, RAPA, and RAPA+LPS. The A549 cells were transfected with the Toll-like receptor 4 (TLR4) overexpression plasmid to be divided into four groups (n=3 each): TLR4 overexpression control, TLR4 overexpression, TLR4 overexpression control+LPS, and TLR4 overexpression+LPS. The A549 cells were transfected with TLR4 siRNA to be divided into four groups (n=3 each): TLR4 silencing control,TLR4 silencing, TLR4 silencing control+LPS, and TLR4 silencing+LPS. CCK-8 assay was used to measure cell viability. Western blot was used to measure the protein expression levels of inflammatory indicators (NLRP3, Caspase-1, and ASC), autophagic indicators (LC3B, Beclin-1, and P62), and TLR4.
RESULTS:
After stimulation with 1 μg/mL LPS for 12 hours, the levels of inflammatory indicators (NLRP3, Caspase-1, and ASC), autophagic indicators (LC3B, Beclin-1, and P62), and TLR4 increased and reached the peak (P<0.05). Compared with the LPS group, the 3-MA+LPS group had reduced expression of autophagy-related proteins and increased expression of inflammation-related proteins and TLR4, while the RAPA+LPS group had increased expression of autophagy-related proteins and reduced inflammation-related proteins and TLR4 (P<0.05). The TLR4 overexpression+LPS group had reduced autophagy-related proteins and increased inflammation-related proteins compared with the TLR4 overexpression control+LPS group, and the TLR4 silencing+LPS group had increased autophagy-related proteins and reduced inflammation-related proteins compared with the TLR4 silencing control+LPS group (P<0.05).
CONCLUSIONS
In the LPS-induced inflammatory response of human alveolar epithelial A549 cells, autophagic flux has a certain protective effect on A549 cells. TLR4-mediated autophagic flux negatively regulates the LPS-induced inflammatory response of A549 cells.
Humans
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A549 Cells
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Autophagy
;
Beclin-1/metabolism*
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Caspase 1/metabolism*
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Inflammation
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Lipopolysaccharides/pharmacology*
;
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism*
;
Toll-Like Receptor 4/metabolism*
4.Effect and mechanism of EGFR expression in macrophages on the anti-cancer effect of berberine on colorectal cancer.
Ning LU ; ; Zhongsheng TONG ; Mei ZHANG ; Lu LU ; Hailong CAO
Chinese Journal of Oncology 2015;37(5):342-346
OBJECTIVETo investigate the effect and explore its possible mechanisms of epidermal growth factor receptor(EGFR) expression in macrophages on the anti-cancer effect of berberine (BER) on the growth of colorectal cancer.
METHODSMice with EGFR gene defects in macrophages (Egfr(fl/fl) LysM-Cre) and with EGFR gene expression in macrophages (LysM-Cre) (control group) were treated with azoxymethane (AOM) to establish colorectal tumor models. These models were treated with or without berberine (BER) intervention. The number of colorectal tumors and the gut length in the two groups were measured. The proliferation of tumor cells was detected by Ki-67 immunohistochemistry and apoptosis was detected by annexin V-FITC fluorescence labeling. Western blot was used to detect the expression of cleaved-caspase-3 protein.
RESULTSAfter treated with AOM, the colorectal tumor number was 10.26 ± 1.43 in the LysM-Cre group and 7.62 ± 1.05 in the Egfr(fl/fl) LysM-Cre group, showing a significant difference (P = 0.021). The gut length was (6.04 ± 1.06) cm in the LysM-Cre group and (6.39 ± 0.92) cm in the gfrfl/flLysM-Cre group, with a non-significant difference between the two groups (P = 0.075). After treated with AOM plus BER intervention, the colorectal tumor number of the LysM-Cre group was 8.35 ± 1.22 and that in the Egfr(fl/fl) LysM-Cre group was 2.66 ± 0.38, showing a very significant difference between the two groups (P = 0.006). The gut length of the LysM-Cre group was (7.34 ± 1.16) cm and that of the Egfr(fl/fl) LysM-Cre group was (10.01 ± 1.72) cm (P = 0.028). After treated with AOM, the ratio of Ki-67-positive tumor cells in the LysM-Cre group was (78.31 ± 3.43)% and that in the Egfr(fl/fl) LysM-Cre group was (75.85 ± 2.92)% (P = 0.282). After AOM plus BER treatment, the ratio of Ki-67-positive tumor cells in the LysM-Cre group was (42.43 ± 3.09)% and that in the Egfr(fl/fl) LysM-Cre group was significantly lower (29.65 ± 2.47)% (P = 0.018). The ratio of annexin V-positive tumor cells was (0.95 ± 0.13)% in the LysM-Cre group, not significantly different from (1.13 ± 0.16)% in the Egfr(fl/fl) LysM-Cre group (P = 0.175). After AOM plus BER treatment, the ratio of annexin V-positive tumor cells in the LysM-Cre group was (32.10 ± 1.97)%, significantly lower than the (47.08 ± 2.83)% in the Egfr(fl/fl) LysM-Cre group (P = 0.010). The level of cleaved-caspase-3 protein expression was 235.92 ± 19.73 in the Egfr(fl/fl) LysM-Cre group, significantly higher than the 119.71 ± 12.87 in the LysM-Cre group (P = 0.012).
CONCLUSIONSThe growth of colorectal cancer cells in mice can be inhibited by BER treatment, and this anti-cancer effect of BER can be further enhanced by EGFR gene knockout in macrophages. The mechanisms may be related to the inhibition of proliferation and promotion of apoptosis in colorectal cancer cells.
Animals ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Apoptosis ; Berberine ; pharmacology ; therapeutic use ; Caspase 3 ; Colorectal Neoplasms ; drug therapy ; Genes, erbB-1 ; physiology ; Immunohistochemistry ; Macrophages ; metabolism ; Mice
5.Protection effect and mechanism of hemin against ischemia/reperfusion injury in rat hearts.
Xiao-Ming CHEN ; Bi-E TANG ; Wei-Ming SUN ; Yang WANG
Chinese Journal of Applied Physiology 2014;30(1):70-73
OBJECTIVETo investigate whether the cardioprotective effect of hemin against ischemia/reperfusion (I/R) injury is through the inhibition of calpain activity, and to explore its underlying mechanism.
METHODSSixty-four SD rats were randomly divided into eight groups (n = 8): sham, I/R, MDL+ I/R, MDL, hemin + I/R, hemin, and ZnPP + hemin+ I/R, ZnPP. Iangendorff isolated rat heart perfusion model was used. The rat hearts were suffered from 40 min of ischemia followed by 30 min of reperfusion. After that, left ventricular developed pressure (LVDP) was recorded. Infarct size and release of lactate dehydrogenase (LDH) were measured. Calpain, heme oxygenase (HO), and caspase 3 activities were evaluated. Expression of calpastatin protein was detected by Western blot.
RESULTS(1) After suffered from ischemia/reperfusion, the calpain activity and caspase 3 activity increased. MDL28170, an inhibitor of calpain, prevented ischemia/reperfusion induced increases in LDH and infarct size, improved the LVDP recovery. (2) Compared with ischema/reperfusion rat hearts, pretreatment of hemin enhanced the HO-1 activity, decreased the calpain and caspase 3 activities, declined LDH release and infarct size, and improved LVDP recovery. (3) Ischemia/reperfusion reduced the expression of calpastatin protein in rat hearts, which was inhibited by hemin pretreatment. And HO-1 inhibitor could abolish the cardioprotection of hemin.
CONCLUSIONCardioprotective effect of hemin against ischemia/reperfusion injury is through the inhibition of calpain activity, the mechanism might be involved in the increase in calpastatin protein expression.
Animals ; Calpain ; metabolism ; Cardiotonic Agents ; pharmacology ; Caspase 3 ; metabolism ; Heme Oxygenase-1 ; metabolism ; Hemin ; pharmacology ; L-Lactate Dehydrogenase ; metabolism ; Myocardial Reperfusion Injury ; drug therapy ; Rats ; Rats, Sprague-Dawley
6.Mycophenolic Acid Synergizing with Lipopolysaccharide to Induce Interleukin-1β Release via Activation of Caspase-1.
Xue-Chan HUANG ; Yi HE ; Jian ZHUANG ; Juan HE ; Gui-Hu LUO ; Jiao-Chan HAN ; Er-Wei SUN
Chinese Medical Journal 2018;131(13):1533-1540
BackgroundThe previous study showed that mycophenolic acid (MPA) synergizing with lipopolysaccharide (LPS) promoted interleukin (IL)-1β release, but the mechanism is unclear. This study aimed to investigate the mechanism of MPA synergizing with LPS to induce IL-1β release.
MethodsUndiluted human blood cells, THP-1 human myeloid leukemia mononuclear cells (THP-1) cells, or monocytes were stimulated with LPS and treated with or without MPA, and the supernatant IL-1β was detected by enzyme-linked immunosorbent assay. The mRNA levels of IL-1β were detected by real-time quantitative polymerase chain reaction. The intracellular protein levels of nuclear factor kappa B (NF-κB) phospho-p65 (p-p65), precursor interleukin-1β (pro-IL-1β), NOD-like receptor pyrin domain containing-3 (NLRP3), and cysteine aspartic acid-specific protease-1 (caspase-1) p20 in THP-1 cell were measured by Western blot.
ResultsThe MPA alone failed to induce IL-1β, whereas MPA synergized with LPS to increase IL-1β in a dose-dependent manner (685.00 ± 20.00 pg/ml in LPS + 5 μmol/L MPA group, P = 0.035; 742.00 ± 31.58 pg/ml in LPS + 25 μmol/L MPA group, P = 0.017; 1000.00 ± 65.59 pg/ml in LPS + 75 μmol/L MPA group, P = 0.024; versus 408.00 ± 35.50 pg/ml in LPS group). MPA alone has no effect on the IL-1β mRNA expression, LPS induced the expression of IL-1β mRNA 2761 fold, and LPS + MPA increased the IL-1β expression 3018 fold, which had the same effect with LPS group (P = 0.834). MPA did not affect the intracellular NF-κB p-p65 and pro-IL-1β protein levels but activated NLRP3 inflammasome. Ac-YVAD-cmk blocked the activation of caspase-1 and subsequently attenuated IL-1β secretion (181.00 ± 45.24 pg/ml in LPS + MPA + YVAD group vs. 588.00 ± 41.99 pg/ml in LPS + MPA group, P = 0.014).
ConclusionsTaken together, MPA synergized with LPS to induce IL-1β release via the activation of caspase-1, rather than the enhanced production of pro-IL-1β. These findings suggested that patients immunosuppressed with mycophenolate mofetil may have overly activated caspase-1 during infection, which might contribute to a more sensitive host defense response to invading germs.
Animals ; Caspase 1 ; metabolism ; Cells, Cultured ; Humans ; Inflammasomes ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; pharmacology ; Mice ; Mice, Inbred NOD ; Mycophenolic Acid ; pharmacology ; NLR Family, Pyrin Domain-Containing 3 Protein
7.The Chinese herbal prescription JieZe-1 inhibits caspase-1-dependent pyroptosis induced by herpes simplex virus-2 infection in vitro.
Tong LIU ; Qing-Qing SHAO ; Wen-Jia WANG ; Tian-Li LIU ; Xi-Ming JIN ; Li-Jun XU ; Guang-Ying HUANG ; Zhuo CHEN
Journal of Integrative Medicine 2023;21(3):277-288
OBJECTIVE:
JieZe-1 (JZ-1), a Chinese herbal prescription, has an obvious effect on genital herpes, which is mainly caused by herpes simplex virus type 2 (HSV-2). Our study aimed to address whether HSV-2 induces pyroptosis of VK2/E6E7 cells and to investigate the anti-HSV-2 activity of JZ-1 and the effect of JZ-1 on caspase-1-dependent pyroptosis.
METHODS:
HSV-2-infected VK2/E6E7 cells and culture supernate were harvested at different time points after the infection. Cells were co-treated with HSV-2 and penciclovir (0.078125 mg/mL) or caspase-1 inhibitor VX-765 (24 h pretreatment with 100 μmol/L) or JZ-1 (0.078125-50 mg/mL). Cell counting kit-8 assay and viral load analysis were used to evaluate the antiviral activity of JZ-1. Inflammasome activation and pyroptosis of VK2/E6E7 cells were analyzed using microscopy, Hoechst 33342/propidium iodide staining, lactate dehydrogenase release assay, gene and protein expression, co-immunoprecipitation, immunofluorescence, and enzyme-linked immunosorbent assay.
RESULTS:
HSV-2 induced pyroptosis of VK2/E6E7 cells, with the most significant increase observed 24 h after the infection. JZ-1 effectively inhibited HSV-2 (the 50% inhibitory concentration = 1.709 mg/mL), with the 6.25 mg/mL dose showing the highest efficacy (95.76%). JZ-1 (6.25 mg/mL) suppressed pyroptosis of VK2/E6E7 cells. It downregulated the inflammasome activation and pyroptosis via inhibiting the expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (P < 0.001) and interferon-γ-inducible protein 16 (P < 0.001), and their interactions with apoptosis-associated speck-like protein containing a caspase recruitment domain, and reducing cleaved caspase-1 p20 (P < 0.01), gasdermin D-N (P < 0.01), interleukin (IL)-1β (P < 0.001), and IL-18 levels (P < 0.001).
CONCLUSION
JZ-1 exerts an excellent anti-HSV-2 effect in VK2/E6E7 cells, and it inhibits caspase-1-dependent pyroptosis induced by HSV-2 infection. These data enrich our understanding of the pathologic basis of HSV-2 infection and provide experimental evidence for the anti-HSV-2 activity of JZ-1. Please cite this article as: Liu T, Shao QQ, Wang WJ, Liu TL, Jin XM, Xu LJ, Huang GY, Chen Z. The Chinese herbal prescription JieZe-1 inhibits caspase-1-dependent pyroptosis induced by herpes simplex virus-2 infection in vitro. J Integr Med. 2023; 21(3): 277-288.
Caspase 1/metabolism*
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Inflammasomes/pharmacology*
;
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism*
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Pyroptosis
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Simplexvirus/metabolism*
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Drugs, Chinese Herbal/pharmacology*
;
Herpes Simplex/drug therapy*
;
Humans
8.Anti-pyroptosis effect of Albiziae Cortex-Tribuli Fructus combination on hepatic stellate cell line LX2: based on network pharmacology.
Ze-Yu XIE ; Yi-Xiao XU ; Meng-Yuan ZHENG ; Jing-Ru ZHENG ; Li YAO
China Journal of Chinese Materia Medica 2023;48(2):481-491
Based on network pharmacology, molecular docking, and in vitro experimental verification, this study aims to explore the effect of Albiziae Cortex-Tribuli Fructus combination on HSC-LX2 pyroptosis. Specifically, the targets of Albiziae Cortex, Tribuli Fructus, and hepatic fibrosis were retrieved from an online database and CNKI, and "drug-component-target" network and "drug-component-target-disease" network were constructed. Protein-protein interaction(PPI) network was established based on STRING. Metascape was employed for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment, and the mechanism of Albiziae Cortex-Tribuli Fructus combination against liver fibrosis was predicted. Molecular docking was used to verify some of the results of network pharmacology, and in vitro experiment was carried out to further verify the above conclusions. According to the results of network pharmacological analysis, 25 active components and 439 targets of Albiziae Cortex-Tribuli Fructus combination and 152 anti-liver fibrosis targets were screened out, including nucleotide-binding oligomerization domain and leucine-rich-repeat-and pyrin-domain-containing 3(NLRP3) and caspase-1. The key targets were involved in 194 KEGG pathways in which the NOD-like receptor signaling pathway topped. The binding common targets were related to pyroptosis. The results of in vitro experiment showed that the pair-containing serum reduced the proliferation rate of HSC-LX2 and the content of reactive oxygen species(ROS), interleukin-18(IL-18), and interleukin-1β(IL-1β)(P<0.05). Western blot and qRT-PCR suggested that the protein and gene expression of NLRP3, caspase-1, α-smooth muscle actin(α-SMA), and gasdermin D(GSDMD) in HSC-LX2 increased after AngⅡ stimulation, and the expression decreased after the intervention of pair-containing serum(P<0.05). In summary, the pair-containing serum can inhibit the classic pathway of pyroptosis, which may be the anti-liver fibrosis mechanism. This is consistent with the predicted results of network pharmacology.
Humans
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Hepatic Stellate Cells
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Network Pharmacology
;
Molecular Docking Simulation
;
NLR Family, Pyrin Domain-Containing 3 Protein
;
Caspase 1/genetics*
;
Fibrosis
;
Drugs, Chinese Herbal/pharmacology*
9.Effect of procalcitonin on lipopolysaccharide-induced expression of nucleotide-binding oligomerization domain-like receptor protein 3 and caspase-1 in human umbilical vein endothelial cells.
Wen JIANG ; Ding-Hua SHI ; Yan-Juan HE ; Chun-Yuan CHEN
Chinese Journal of Contemporary Pediatrics 2023;25(5):521-526
OBJECTIVES:
To study the effect of procalcitonin (PCT) on lipopolysaccharide (LPS)-induced expression of the pyroptosis-related proteins nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and caspase-1 in human umbilical vein endothelial cells (HUVECs).
METHODS:
HUVECs were induced by LPS to establish a model of sepsis-induced inflammatory endothelial cell injury. The experiment was divided into two parts. In the first part, HUVECs were randomly divided into four groups: normal control, LPS (1 μg/mL), PCT (10 ng/mL), and LPS+PCT (n=3 each). In the second part, HUVECs were randomly grouped: normal control, LPS, and LPS+PCT of different concentrations (0.1, 1, 10, and 100 ng/mL) (n=3 each). Quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression levels of NLRP3 and caspase-1 in each group.
RESULTS:
In the first experiment: compared with the normal control group, the PCT, LPS, and LPS+PCT groups had significantly upregulated mRNA and protein expression levels of NLRP3 and caspase-1 (P<0.05); compared with the LPS group, the LPS+PCT group had significantly downregulated mRNA and protein expression levels of NLRP3 and caspase-1 (P<0.05). In the second experiment: compared with those in the LPS group, the mRNA and protein expression levels of NLRP3 and caspase-1 in the LPS+PCT of different concentrations groups were significantly downregulated in a concentration-dependent manner (P<0.05).
CONCLUSIONS
LPS can promote the expression of the pyroptosis-related proteins NLRP3 and caspase-1 in HUVECs, while PCT can inhibit the LPS-induced expression of the pyroptosis-related proteins NLRP3 and caspase-1 in HUVECs in a concentration-dependent manner.
Humans
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Caspase 1/metabolism*
;
Human Umbilical Vein Endothelial Cells/metabolism*
;
Lipopolysaccharides/pharmacology*
;
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism*
;
Procalcitonin
;
Nucleotides/pharmacology*
10.Apoptosis-dependent acute pulmonary injury after intratracheal instillation of angiotensin II.
Jia-Ju ZHUANG ; Xiao-Peng LI ; Bruce David UHAL ; Koh Rhun YIAN
Acta Physiologica Sinica 2008;60(6):715-722
To test the hypothesis that exogenous purified angiotensin II (ANG) might cause apoptosis of alveolar epithelial cells (AECs) and acute lung injury, male Wistar rats were intratracheally instilled with purified ANG (10 mumol/L), ANG plus the caspase inhibitor ZVAD-fmk (60 mumol/L), ANG plus the ANG receptor AT1 antagonist losartan (LOS, 100 mumol/L) or sterile phosphate-buffered saline (PBS) vehicle alone. Six or 20 h later, the lungs were lavaged in situ for determination of bronchoalveolar lavage (BAL) fluid content of hemoglobin (Hb) and fluorescent (BODIPY)-albumin, a bolus of which was injected intravenously 15 min prior to BAL. Terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) revealed that instillation of ANG, but not PBS alone, increased labeling of fragmented DNA in bronchiolar epithelial cells and in AECs (P<0.05) at 6 h post-ANG. Increased TUNEL was abrogated by concurrent instillation of ZVAD-fmk or LOS. Significant increased numbers of caspase-positive cells were observed by anti-caspase 3 immunolabeling after instillation of ANG (P<0.01); the same doses of LOS or ZVAD-fmk that blocked TUNEL also blocked the activation of caspase 3 (P<0.01). Intratracheal instillation of ANG also remarkably increased BAL BODIPY-albumin (P< 0.01) and Hb (P<0.05), both of which were eliminated by ZVAD-fmk or LOS. These data indicate that exposure of AECs to ANG in vivo is sufficient to induce apoptosis and alveolar epithelial barrier injury mediated by ANG receptor AT1.
Amino Acid Chloromethyl Ketones
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pharmacology
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Angiotensin II
;
adverse effects
;
Angiotensin II Type 1 Receptor Blockers
;
pharmacology
;
Animals
;
Apoptosis
;
Caspase 3
;
metabolism
;
Caspase Inhibitors
;
pharmacology
;
Epithelial Cells
;
pathology
;
Losartan
;
pharmacology
;
Lung Injury
;
chemically induced
;
pathology
;
Male
;
Rats
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Rats, Wistar
;
Receptor, Angiotensin, Type 1
;
metabolism