1.Role of the nuclear factor-kappa B signaling pathway in the repair of white matter injury in neonatal rats through human umbilical cord mesenchymal stem cell transplantation.
Shu-Juan ZHANG ; Chao WANG ; Qian-Qian XU ; Jun ZHANG ; Yan-Ping ZHU
Chinese Journal of Contemporary Pediatrics 2024;26(12):1352-1361
OBJECTIVES:
To observe the reparative effects of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation on white matter injury (WMI) in neonatal rats and explore its mechanism through the nuclear factor-kappa B (NF-κB) signaling pathway mediated by microglial cells.
METHODS:
Sprague-Dawley rats, aged 2 days, were randomly divided into three groups: sham-operation,WMI, and hUC-MSC (<i>ni>=18 each). Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in the white matter, and immunofluorescence staining was used to measure the expression level of ionized calcium-binding adapter molecule 1 (Iba1). Western blotting was used to measure the protein expression levels of inhibitory subunit of nuclear factor-kappa B alpha (IκBα), phosphorylated IκBα (p-IκBα), phosphorylated NF-κB p65 (p-NF-κB p65), myelin basic protein (MBP), and neuron-specific nuclear protein (NeuN). Quantitative real-time PCR was used to assess the mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), MBP, and NeuN. Immunohistochemistry was used to measure the protein expression levels of MBP and NeuN. On day 28, the Morris water maze test was used to evaluate spatial cognitive ability.
RESULTS:
Fourteen days after modeling, the sham-operation group exhibited intact white matter structure with normal cell morphology and orderly nerve fiber arrangement. In the WMI group, large-scale cell degeneration and necrosis were observed, and nerve fiber arrangement was disordered. The hUC-MSC group showed relatively normal cell morphology and more orderly nerve fibers. Compared with the sham-operation group, the WMI group had significantly higher proportions of Iba1-positive cells, increased protein levels of p-IκBα and p-NF-κB p65, and higher mRNA levels of TNF-α and IL-1β. The protein expression of IκBα and the positive expression of MBP and NeuN, as well as their protein and mRNA levels, were significantly reduced in the WMI group (<i>Pi><0.05). Compared with the WMI group, the hUC-MSC group showed reduced proportions of Iba1-positive cells, decreased protein levels of p-IκBα and p-NF-κB p65, and lower mRNA levels of TNF-α and IL-1β. Furthermore, IκBα protein expression and MBP and NeuN expression (both at the protein and mRNA levels) were significantly increased in the hUC-MSC group (<i>Pi><0.05). On day 28, the Morris water maze results showed that compared with the sham-operation group, the WMI group had significantly longer escape latency and fewer platform crossings (<i>Pi><0.05). In contrast, the hUC-MSC group had significantly shorter escape latency and more platform crossings than the WMI group (<i>Pi><0.05).
CONCLUSIONS
hUC-MSC transplantation can repair WMI in neonatal rats, promote the maturation of oligodendrocytes, and support neuronal survival, likely by inhibiting activation of the NF-κB signaling pathway mediated by microglial cells.
Animals
;
Rats, Sprague-Dawley
;
White Matter/metabolism*
;
Rats
;
Signal Transduction
;
Mesenchymal Stem Cell Transplantation
;
Humans
;
NF-kappa B/metabolism*
;
Animals, Newborn
;
Umbilical Cord/cytology*
;
Male
;
NF-KappaB Inhibitor alpha/metabolism*
;
I-kappa B Proteins/genetics*
;
Microfilament Proteins/analysis*
;
Calcium-Binding Proteins/metabolism*
;
Female
2.Mechanism of Panlongqi Tablets intervening in vertebral artery type of cervical spondylosis in rats through PI3K/AKT signaling pathway based on network pharmacology and experimental verification.
Rui-Rui MING ; Yan-Qiong ZHANG ; Ying XU ; Teng-Teng XU ; Luo-Chang-Ting FANG ; Jin-Xia WANG ; Xiao-Xiao WANG ; Zhi-Xing HU ; Chao YANG ; Ke-Xin JIA ; Lu WANG ; Chun-Fang LIU ; Na LIN
China Journal of Chinese Materia Medica 2022;47(16):4454-4461
This study aimed to further explore the relevant mechanism of action by network pharmacology integrated with animal experimental verification based on previous proven effective treatment of vertebral artery type of cervical spondylosis(CSA) by Panlongqi Tablets. Bionetwork analysis was performed to establish drug-disease interaction network, and it was found that the key candidate targets of Panlongqi Tablets were enriched in multiple signaling pathways related to CSA pathological links, among which phosphatidylinositol 3-kinase(PI3 K)/serine-threonine kinase(AKT/PKB) signaling pathway was the most significant. Further, mixed modeling method was used to build the CSA rat model, and the rats were divided into normal, model, Panlongqi Tablets low-, medium-and high-dose(0.16, 0.32, 0.64 g·kg~(-1)) and Jingfukang Granules(positive drug, 1.35 g·kg~(-1)) groups. After successful modeling, the rats were administered for 8 consecutive weeks. Pathological changes of rat cervical muscle tissues were detected by hematoxylin-eosin(HE) staining, and the content of interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), vascular endothelial cell growth factor(VEGF) and chemokine(C-C motif) ligand 2(CCL2) in rat serum and/or cervical tissues was determined by enzyme-linked immunosorbent assay(ELISA). Western blot was employed to detect the protein expression levels of chemokine(C-C motif) receptor 2(CCR2), PI3 K, AKT, phosphorylated AKT(p-AKT), I-kappa-B-kinase beta(IKK-beta/IKKβ), nuclear factor kappa B(NF-κB P65) and phosphorylated nuclear factor kappa B(NF-κB p-P65) in rat cervical tissues, and positive expression of p-NF-κB P65 in rat cervical muscle tissues was detected by immunofluorescence. The results showed that Panlongqi Tablets at different doses improved the degree of muscle fibrosis and inflammation in cervical muscle tissues of CSA rats, and reduced the content of inflammatory factors IL-1β, TNF-α, VEGF, CCL2 and CCR2 in serum and/or cervical tissues. The protein expression levels of PI3 K, p-AKT, IKKβ and p-NF-κB P65 as well as the nuclear entry of p-NF-κB P65 in cervical tissues were down-regulated. These findings suggest that Panlongqi Tablets can significantly inhibit the inflammatory response of CSA rats, and the mechanism of action may be related to the down-regulation of the activation of PI3 K/AKT signaling pathway.
Animals
;
Drugs, Chinese Herbal
;
I-kappa B Kinase/pharmacology*
;
NF-kappa B/metabolism*
;
Network Pharmacology
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Protein Serine-Threonine Kinases
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Rats
;
Signal Transduction
;
Spondylosis/drug therapy*
;
Tumor Necrosis Factor-alpha/metabolism*
;
Vascular Endothelial Growth Factor A/genetics*
;
Vertebral Artery/metabolism*
3.Topoisomerase inhibitor upregulates MICA/B expression in breast cancer cells through ATM/ATR and NF-κB pathway.
Yan ZHU ; Yong Jin SHI ; Yu Liang ZHAO ; Ping ZHU
Journal of Peking University(Health Sciences) 2018;50(2):318-325
OBJECTIVE:
To investigate the effects of chemotherapeutic agents widely used in clinical practice on major histocompatibility complex class I-related chain A and B (MICA/B) expression in breast cancer cells, and to explore the molecular mechanisms involved.
METHODS:
We examined MICA/B mRNA and surface protein expressions in breast cancer cells treated with chemotherapeutic agents by real-time RT-PCR and flow cytometry respectively. The blocking effects of ataxia telangiectasia mutated and Rad3-related kinase (ATM/ATR) inhibitor caffeine and nuclear factor κB (NF-κB) inhibitor pynolidine dithiocarbamate (PDTC) on etoposide-upregulated MICA/B mRNA and surface protein expressions were investigated. Electrophoretic mobility shift assay (EMSA) was taken to investigate whether etoposide enhanced the binding of NF-κB to MICA/B gene promoter.
RESULTS:
Three topoisomerase inhibitors etoposide, camptothecin and doxorubicine upregulated MICA and MICB mRNA expressions in breast cancer cell MCF-7. Comparing to no-drug-treated cells, MICA mRNA levels increased to (1.68±0.17), (2.54±0.25) and (3.42±0.15) fold, and levels of MICB mRNA increased to (1.82±0.24), (1.56±0.05) and (5.84±0.57) fold respectively in cancer cells treated by etoposide at the concentrations of 5, 20 and 100 μmol/L (P<0.05). MICA and MICB mRNA levels also increased significantly when MCF-7 cells were incubated with camptothecin or doxorubicine at the specific concentrations (P<0.05). MICB mRNA expression also increased slightly in another breast cancer cell SK-BR-3 treated by topoisomerase II inhibitors etoposide and camptothecin (P<0.05). Furthermore, etoposide and camptothecin upregulated MICA/B surface protein expression in MCF-7 cells (P<0.05), and the upregulation was found in both living and apoptotic cells. Our study showed that etoposide induced-MICA/B expression in MCF-7 was inhibited by caffeine at different concentrations. When cancer cells were treated by caffeine with 1, 5 and 10 mmol/L, MICA mRNA levels decreased from (3.75±0.25) to (0.89±0.05), (0.81±0.02) and (0.48±0.04) fold respectively (P<0.001), and MICB mRNA levels decreased from (6.85±0.35) to (1.36±0.13), (0.76±0.06) and (0.56±0.03) fold (P<0.05), while MICA/B protein levels decreased from (3.42±0.05) to (1.32±0.03), (1.21±0.06) and (1.14±0.03) fold (P<0.001), indicating that etoposide-induced MICA/B expression was inhibited by ATM/ATR inhibitor. Similarly, NF-κB inhibitor PDTC also inhibited MICA/B mRNA and protein expressions induced by etoposide significantly when MCF-7 cells were incubated with PDTC at the concentrations of 10, 50 and 100 μmol/L (P<0.05), indicating that NF-κB was also involved in this process. EMSA showed that the binding of NF-κB to MICA/B promoter enhanced in MCF-7 cells after etoposide treatment.
CONCLUSION
Topoisomerase inhibitor increased MICA/B mRNA and protein expressions in breast cancer cells, indicating that chemotherapeutic agents might increase the recognizing and killing ability of immunocytes to breast cancer cells. ATM/ATR and NF-κB pathways might be involved in it.
Antineoplastic Agents/pharmacology*
;
Ataxia Telangiectasia Mutated Proteins/physiology*
;
Breast Neoplasms/genetics*
;
Cell Line, Tumor
;
Doxorubicin
;
Etoposide/pharmacology*
;
Histocompatibility Antigens Class I
;
Humans
;
I-kappa B Proteins
;
NF-kappa B/physiology*
;
RNA, Messenger
;
Topoisomerase Inhibitors
;
Up-Regulation
4.Hydroxysafflor yellow A attenuate lipopolysaccharide-induced endothelium inflammatory injury.
Ming JIN ; Chun-Yan SUN ; Bao-Xia ZANG
Chinese journal of integrative medicine 2016;22(1):36-41
<b>OBJECTIVEb>This study observed attenuating effect of hydroxysafflor yellow A (HSYA), an effective ingredient of aqueous extract of Carthamus tinctorius L, on lipopolysaccharide (LPS)-induced endothelium inflammatory injury.
<b>METHODSb>Eahy926 human endothelium cell (EC) line was used; thiazolyl blue tetrazolium bromide (MTT) test was assayed to observe the viability of EC; Luciferase reporter gene assay was applied to measure nuclear factor-κB (NF-κB) p65 subunit nuclear binding activity in EC; Western blot technology was used to monitor mitogen activated protein kinase (MAPKs) and NF-κB activation. Reverse transcription polymerase chain reaction (RT-PCR) method was applied to observe intercellular cell adhesion molecule-1 (ICAM-1) and E-selectin mRNA level; EC surface ICAM-1 expression was measured with flow cytometry and leukocyte adhesion to EC was assayed with Rose Bengal spectrophotometry technology.
<b>RESULTSb>HSYA protected EC viability against LPS-induced injury (P <0.05). LPS-induced NF-κB p65 subunit DNA binding (P <0.01) and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor α (IκBα) phosphorylation was inhibited by HSYA. HSYA attenuated LPS triggered ICAM-1 and E-selectin mRNA levels elevation and phosphorylation of p38 MAPK or c-Jun N-terminal kinase MAPK. HSYA also inhibited LPS-induced cell surface ICAM-1 protein expression P <0.01) and leukocyte adhesion to EC (P <0.05).
<b>CONCLUSIONb>HSYA is effective to protect LPS-induced high expression of endothelium adhesive molecule and inflammatory signal transduction.
Cell Adhesion ; drug effects ; Cell Nucleus ; drug effects ; metabolism ; Cell Survival ; drug effects ; Chalcone ; analogs & derivatives ; chemistry ; pharmacology ; therapeutic use ; E-Selectin ; genetics ; metabolism ; Endothelium, Vascular ; drug effects ; pathology ; Gene Expression Regulation ; drug effects ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; pathology ; Humans ; I-kappa B Proteins ; metabolism ; Inflammation ; drug therapy ; pathology ; Intercellular Adhesion Molecule-1 ; genetics ; metabolism ; Leukocytes ; cytology ; drug effects ; Lipopolysaccharides ; MAP Kinase Signaling System ; drug effects ; NF-KappaB Inhibitor alpha ; Phosphorylation ; drug effects ; Protective Agents ; pharmacology ; Protein Binding ; drug effects ; Quinones ; chemistry ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism
5.Construction and function identification of luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR.
Shuo YANG ; Jia-li LI ; Hui-chang BI ; Shou-ning ZHOU ; Xiao-man LIU ; Hang ZENG ; Bing-fang HU ; Min HUANG
Acta Pharmaceutica Sinica 2016;51(1):80-85
This study aims to investigate the function of two SNPs (rs8904C > T and rs696G >A) in 3' untranslated region (3'UTR) of NFKBIA gene by constructing luciferase reporter gene. A patient's genomic DNA with rs8904 CC and rs696 GA genotype was used as the PCR template. Full-length 3'UTR of NFKBIA gene was amplified by different primers. After sequencing validation, these fragments were inserted to the luciferase reporter vector, pGL3-promoter to construct recombinant plasmids containing four kinds of haplotypes, pGL3-rs8904C/rs696G, pGL3-rs8904C/rs696A, pGL3-rs8904T/rs696G and pGL3-rs8904T/rs696A. Then these plasmids were transfected into LS174T cells and the luciferase activity was detected. Compared with pGL3-vector transfected cells (negative control), the luciferase activity of the four kinds of recombinant plasmids was significantly decreased (P < 0.001). For rs696G > A, the luciferase activity of the recombinant plasmids containing A allele (pGL3-rs8904C/rs696A and pGL3-rs8904T/rs696A) was about 45.1% (P < 0.05) and 56.1% (P < 0.001) lower than those containing G allele (pGL3-rs8904C/rs696G and pGL3-rs8904T/rs696G), respectively. For rs8904C > T, there were no significant differences in the luciferase activity between the recombinant plasmids containing T allele and those with C allele. Together, the luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR were constructed successfully and rs696G > A could decrease the luciferase activity while rs8904C >T didn't have much effect on the luciferase activity.
3' Untranslated Regions
;
Genes, Reporter
;
Genetic Vectors
;
Humans
;
I-kappa B Proteins
;
genetics
;
Luciferases
;
NF-KappaB Inhibitor alpha
;
Plasmids
;
Polymorphism, Single Nucleotide
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Promoter Regions, Genetic
;
Transfection
6.Berberine relieves insulin resistance via the cholinergic anti-inflammatory pathway in HepG2 cells.
Fen LI ; Yun-bin ZHAO ; Ding-kun WANG ; Xin ZOU ; Ke FANG ; Kai-fu WANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2016;36(1):64-69
Berberine (BBR) is an isoquinoline alkaloid extracted from Rhizoma coptidis and has been used for treating type 2 diabetes mellitus (T2DM) in China. The development of T2DM is often associated with insulin resistance and impaired glucose uptake in peripheral tissues. In this study, we examined whether BBR attenuated glucose uptake dysfunction through the cholinergic anti-inflammatory pathway in HepG2 cells. Cellular glucose uptake, quantified by the 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-2-deoxy-D-glucose (2-NBDG), was inhibited by 21% after HepG2 cells were incubated with insulin (10(-6) mol/L) for 36 h. Meanwhile, the expression of alpha7 nicotinic acetylcholine receptor (α7nAChR) protein was reduced without the change of acetylcholinesterase (AChE) activity. The level of interleukin-6 (IL-6) in the culture supernatant, the ratio of phosphorylated I-kappa-B kinase-β (IKκβ) Ser181/IKKβ and the expression of nuclear factor-kappa B (NF-κB) p65 protein were also increased. However, the treatment with BBR enhanced the glucose uptake, increased the expression of α7nAChR protein and inhibited AChE activity. These changes were also accompanied with the decrease of the ratio of pIKKβ Ser181/IKKβ, NF-κB p65 expression and IL-6 level. Taken together, these results suggest that BBR could enhance glucose uptake, and relieve insulin resistance and inflammation in HepG2 cells. The mechanism may be related to the cholinergic anti-inflammatory pathway and the inhibition of AChE activity.
Berberine
;
pharmacology
;
Glucose
;
metabolism
;
Hep G2 Cells
;
Humans
;
Hypoglycemic Agents
;
pharmacology
;
I-kappa B Kinase
;
metabolism
;
I-kappa B Proteins
;
metabolism
;
Insulin
;
metabolism
;
Insulin Resistance
;
Interleukin-6
;
metabolism
;
Transcription Factor RelA
;
metabolism
;
alpha7 Nicotinic Acetylcholine Receptor
;
genetics
;
metabolism
7.DNA sensor cGAS-mediated immune recognition.
Pengyan XIA ; Shuo WANG ; Pu GAO ; Guangxia GAO ; Zusen FAN
Protein & Cell 2016;7(11):777-791
The host takes use of pattern recognition receptors (PRRs) to defend against pathogen invasion or cellular damage. Among microorganism-associated molecular patterns detected by host PRRs, nucleic acids derived from bacteria or viruses are tightly supervised, providing a fundamental mechanism of host defense. Pathogenic DNAs are supposed to be detected by DNA sensors that induce the activation of NFκB or TBK1-IRF3 pathway. DNA sensor cGAS is widely expressed in innate immune cells and is a key sensor of invading DNAs in several cell types. cGAS binds to DNA, followed by a conformational change that allows the synthesis of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) from adenosine triphosphate and guanosine triphosphate. cGAMP is a strong activator of STING that can activate IRF3 and subsequent type I interferon production. Here we describe recent progresses in DNA sensors especially cGAS in the innate immune responses against pathogenic DNAs.
DNA, Bacterial
;
immunology
;
metabolism
;
DNA, Viral
;
immunology
;
metabolism
;
Gene Expression Regulation
;
Host-Pathogen Interactions
;
Humans
;
Immunity, Innate
;
Interferon Regulatory Factor-3
;
genetics
;
immunology
;
Interferon Type I
;
biosynthesis
;
immunology
;
Membrane Proteins
;
genetics
;
immunology
;
Models, Molecular
;
NF-kappa B
;
genetics
;
immunology
;
Nucleotides, Cyclic
;
biosynthesis
;
immunology
;
Nucleotidyltransferases
;
genetics
;
immunology
;
Protein Binding
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Protein-Serine-Threonine Kinases
;
genetics
;
immunology
;
Signal Transduction
8.Astragaloside IV regulates STAT1/IκB/NF-κB signaling pathway to inhibit activation of BV-2 cells.
Yi-xin HE ; Hai-lian SHI ; Hong-shuai LIU ; Hui WU ; Bei-bei ZHANG ; Xiao-jun WU ; Zheng-tao WANG
China Journal of Chinese Materia Medica 2015;40(1):124-128
<b>OBJECTIVEb>The study was aimed to investigate the inhibitory effect and mechanism of astragaloside IV (ASI) on the activation of microglial cells.
<b>METHODb>After pre-incubated with ASI for 2 h, microglial cells BV-2 were stimulated with interferon-γ (IFN-γ) for 1. 5 h and 24 h, respectively. Secretion of nitric oxide (NO) in the medium was measured by Griess method. Production of tumor necrosis factor alpha (TNF-α) was detected by ELISA approach. Cellular gene expressions of CD11b, TNF-α, interleukin 1β (IL-1β) and induced nitric oxide synthase (iNOS) were examined by quantitative-PCR analysis. Total and phosphorylation of STAT1, IκB and NF-κB was analyzed by Western blot method.
<b>RESULTb>ASI could significantly inhibit the increased secretion of TNF-α and NO from BV-2 cells upon IFN-γ stimulation (P < 0.001). Further study showed that ASI significantly down-regulated gene expression of IL-1β and TNF-α (P < 0.01, P < 0.05) and exhibited a trend to reduce that of iNOS. IFN-γ and ASI have no obvious effect on gene expression of CD11b. Moreover, ASI inhibited the phosphorylation of STAT1, IκB and NF-κB elicited by IFN-γ stimulation.
<b>CONCLUSIONb>ASI could restrain microglial activation through interfering STAT1/IκB/NF-κB signaling pathway, reducing gene expres- sion of IL-1β and TNF-α, and thus inhibiting the production of proinflammatory mediators such as NO and TNF-α.
Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; I-kappa B Proteins ; genetics ; metabolism ; Interferon-gamma ; genetics ; metabolism ; Mice ; NF-kappa B ; genetics ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; STAT1 Transcription Factor ; genetics ; metabolism ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Triterpenes ; pharmacology
9.Lentivirus-mediated interference of E3 ubiquitin ligase RNF31 inhibits tumor-necrosis factor-α-induced activation of nuclear factor-κB pathway.
Jie CHEN ; Hui CHEN ; Yiqun ZHAN ; Xiaoming YANG ; Miao YU
Journal of Southern Medical University 2014;34(12):1713-1720
<b>OBJECTIVEb>To study the effect of E3 ubiquitin ligase RNF31 knockdown on nuclear factor-κB (NF-κB) pathway activation and cell apoptosis.
<b>METHODSb>Human RNF31 siRNA sequences were cloned into the lentiviral vector pGreenPuro and transiently transfected in HEK293T cells to screen the most effective fragments, which were co-transfected along with the packaging plasmids PMD and SPA in 293T cells. The cell supernatant was collected at 24 h and 48 h after the transfection and the viral titers were determined with flow cytometry. Real-time PCR and Western blotting were used to evaluate the effect of RNF31 knockdown on the expression of NF-κB downstream target genes and IκBα activity; the changes of NF-κB pathway transcriptional activity were assessed with dual luciferase reporter gene. Hochest dying was used to examine the influence of RNF31 down-regulation on cell apoptosis.
<b>RESULTSb>RNF31 knockdown mediated by the lentiviral vector pGreenPuro-RNF31 suppressed the transcriptional activity of NF-κB and the downstream target genes in HEK293 cells stimulated with TNF-α. RNF31 knockdown also resulted in suppression of NF-κB-stimulated expression of pIκBα and in increased apoptosis of cells stimulated with TNF-α for 24 h.
<b>CONCLUSIONb>RNF31 down-regulation inhibits NF-κB pathway activation induced by TNF-α.
Apoptosis ; Down-Regulation ; Gene Expression Regulation ; Genetic Vectors ; HEK293 Cells ; Humans ; I-kappa B Proteins ; metabolism ; Lentivirus ; NF-KappaB Inhibitor alpha ; NF-kappa B ; metabolism ; RNA, Small Interfering ; Real-Time Polymerase Chain Reaction ; Signal Transduction ; Transfection ; Tumor Necrosis Factor-alpha ; pharmacology ; Ubiquitin-Protein Ligases ; genetics ; metabolism
10.Degradation of the Transcription Factors NF-kappaB, STAT3, and STAT5 Is Involved in Entamoeba histolytica-Induced Cell Death in Caco-2 Colonic Epithelial Cells.
Kyeong Ah KIM ; Arim MIN ; Young Ah LEE ; Myeong Heon SHIN
The Korean Journal of Parasitology 2014;52(5):459-469
Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-kappaB (p65) in Caco-2 cells. However, IkappaB, an inhibitor of NF-kappaB, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-kappaB was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-kappaB and STATs in colonic epithelial cells, which ultimately accelerates cell death.
Caco-2 Cells
;
Calcium-Binding Proteins
;
Calpain/genetics/metabolism
;
Caspase 3/genetics/metabolism
;
Caspases
;
*Cell Death
;
Colon/cytology
;
Entamoeba histolytica/*physiology
;
Epithelial Cells/cytology/parasitology
;
Humans
;
I-kappa B Proteins/metabolism
;
Intestinal Mucosa/cytology
;
NF-kappa B/genetics/*metabolism
;
RNA Interference
;
RNA, Small Interfering
;
STAT3 Transcription Factor/genetics/*metabolism
;
STAT5 Transcription Factor/genetics/*metabolism
;
Signal Transduction

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