1.Cathepsin B in hepatic Kupffer cells regulates activation of TLR4-independent inflammatory pathways in mice with lipopolysaccharide-induced sepsis.
Panpan FENG ; Wei ZHU ; Nan CHEN ; Peizhi LI ; Kun HE ; Jianping GONG
Journal of Southern Medical University 2018;38(12):1465-1471
		                        		
		                        			OBJECTIVE:
		                        			To investigate the role of cathepsin B in hepatic Kupffer cells (KCs) in activating Toll-like receptor 4(TLR- 4)-independent inflammatory pathways in mice with lipopolysaccharide (LPS)-induced sepsis.
		                        		
		                        			METHODS:
		                        			Eighteen wild-type (WT) mice and 18 TLR4-knockout (TLR4) mice were both divided into 3 groups for intraperitoneal injections of a lethal dose (54 mg/kg) of LPS, LPS and CA-074(a cathepsin B inhibitor), or normal saline, and the survival of the mice were observed. Another 36 WT mice and 36 TLR4mice were also divided into 3 groups and subjected to intraperitoneal injections of normal saline, 20 mg/kg LPS, or LPS with CA-074 pretreatment.After the treatments, KCs were collected from the mice for assessing the protein level and activity of cathepsin B.The histopathological changes of the liver were observed with HE staining, and the serum levels of IL-1α, IL-1β, TNF-α and IL-18 were detected.
		                        		
		                        			RESULTS:
		                        			Compared with the WT mice,TLR4mice receiving the lethal dose of LPS had significantly longer survival time (up to 84 h) after the injection,but were still unable to fully resist LPS challenge.CA-074 pretreatment prolonged the survival time of WT mice and TLR4mice to 60 h and 132 h,respectively.In the mouse models of sepsis,20 mg/kg LPS induced significantly enhanced activity of cathepsin B without affecting its expression level in the KCs (<0.05) and increased the serum levels of the inflammatory cytokines.CA-074 pretreatment of the mice obviously lessened the detrimental effects of LPS in TLR4mice by significantly lowering cathepsin B activity in the KCs,alleviating hepatocyte apoptosis and reducing the serum levels of inflammatory cytokines.
		                        		
		                        			CONCLUSIONS
		                        			Cathepsin B plays an important role in activating TLR4-independent inflammatory pathways in mice with LPS-induced sepsis.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cathepsin B
		                        			;
		                        		
		                        			antagonists & inhibitors
		                        			;
		                        		
		                        			physiology
		                        			;
		                        		
		                        			Dipeptides
		                        			;
		                        		
		                        			pharmacology
		                        			;
		                        		
		                        			Gene Knockout Techniques
		                        			;
		                        		
		                        			Hepatocytes
		                        			;
		                        		
		                        			Inflammation
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Interleukin-18
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			Interleukin-1alpha
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			Interleukin-1beta
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			Kupffer Cells
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Lipopolysaccharides
		                        			;
		                        		
		                        			Liver
		                        			;
		                        		
		                        			pathology
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Sepsis
		                        			;
		                        		
		                        			etiology
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Toll-Like Receptor 4
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			Tumor Necrosis Factor-alpha
		                        			;
		                        		
		                        			blood
		                        			
		                        		
		                        	
2.IL-1 Receptor Antagonist Reduced Chemical-Induced Keratinocyte Apoptosis through Antagonism to IL-1α/IL-1β.
Hyejin LEE ; Kyung Ah CHEONG ; Ji Young KIM ; Nan Hyung KIM ; Minsoo NOH ; Ai Young LEE
Biomolecules & Therapeutics 2018;26(4):417-423
		                        		
		                        			
		                        			Extracellular interleukin 1 alpha (IL-1α) released from keratinocytes is one of the endpoints for in vitro assessments of skin irritancy. Although cells dying via primary skin irritation undergo apoptosis as well as necrosis, IL-1α is not released in apoptotic cells. On the other hand, active secretion has been identified in interleukin-1 receptor antagonist (IL-1ra), which was discovered to be a common, upregulated, differentially-expressed gene in a microarray analysis performed with keratinocytes treated using cytotoxic doses of chemicals. This study examined whether and how IL-1ra, particularly extracellularly released IL-1ra, was involved in chemically-induced keratinocyte cytotoxicity and skin irritation. Primary cultured normal adult skin keratinocytes were treated with cytotoxic doses of chemicals (hydroquinone, retinoic acid, sodium lauryl sulfate, or urshiol) with or without recombinant IL-1ra treatment. Mouse skin was administered irritant concentrations of hydroquinone or retinoic acid. IL-1ra (mRNA and/or intracellular/extracellularly released protein) levels increased in the chemically treated cultured keratinocytes with IL-1α and IL-1β mRNAs and in the chemically exposed epidermis of the mouse skin. Recombinant IL-1ra treatment significantly reduced the chemically-induced apoptotic death and intracellular/extracellularly released IL-1α and IL-1β in keratinocytes. Collectively, extracellular IL-1ra released from keratinocytes could be a compensatory mechanism to reduce the chemically-induced keratinocyte apoptosis by antagonism to IL-1α and IL-1β, suggesting potential applications to predict skin irritation.
		                        		
		                        		
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Apoptosis*
		                        			;
		                        		
		                        			Epidermis
		                        			;
		                        		
		                        			Hand
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			In Vitro Techniques
		                        			;
		                        		
		                        			Interleukin 1 Receptor Antagonist Protein
		                        			;
		                        		
		                        			Interleukin-1*
		                        			;
		                        		
		                        			Interleukin-1alpha
		                        			;
		                        		
		                        			Keratinocytes*
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Microarray Analysis
		                        			;
		                        		
		                        			Necrosis
		                        			;
		                        		
		                        			RNA, Messenger
		                        			;
		                        		
		                        			Skin
		                        			;
		                        		
		                        			Sodium Dodecyl Sulfate
		                        			;
		                        		
		                        			Tretinoin
		                        			
		                        		
		                        	
3.Increased Skin Irritation by Hydroquinone and Rsetinoic Acid Used in Combination.
Gwang Hoon KIM ; Kyung Ah CHEONG ; Ai Young LEE
Annals of Dermatology 2017;29(6):715-721
		                        		
		                        			
		                        			BACKGROUND: Hydroquinone (HQ) is frequently combined with retinoic acid (RA) to enhance lightening efficacy, which may also affect skin irritancy. Although skin irritation leads to postinflammatory hyperpigmentation, little research has been performed to compare skin irritancy between each component and the combination. OBJECTIVE: This study was done to examine whether HQ-RA combination increased skin irritation induced by HQ or RA alone. METHODS: Patch testing was performed using maximum therapeutic and higher concentrations of HQ and RA in 10 volunteers, and then, it was performed using their popular therapeutic concentrations and combination in the other 20 volunteers. In vitro irritation was also assessed in primary cultured normal human keratinocytes treated with 80% and 50% cell survival doses of HQ, 80% cell survival dose of RA, and their combination. RESULTS: The combination in patch testing induced stronger erythema than the corresponding concentrations of HQ and RA, which was remarkable with use of combination of higher concentrations. In cultured keratinocytes, the RA combination significantly decreased cell viability, but increased cytotoxicity and extracellular interleukin 1 alpha release with corresponding doses of HQ. CONCLUSION: The results of patch tests and in vitro irritation assessment tests suggested that HQ and RA increased skin irritation when used in combination.
		                        		
		                        		
		                        		
		                        			Cell Survival
		                        			;
		                        		
		                        			Erythema
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Hyperpigmentation
		                        			;
		                        		
		                        			In Vitro Techniques
		                        			;
		                        		
		                        			Interleukin-1alpha
		                        			;
		                        		
		                        			Keratinocytes
		                        			;
		                        		
		                        			Patch Tests
		                        			;
		                        		
		                        			Skin*
		                        			;
		                        		
		                        			Tretinoin
		                        			;
		                        		
		                        			Volunteers
		                        			
		                        		
		                        	
4.Effect of colon cancer cell-derived IL-1α on the migration and proliferation of vascular endothelial cells.
Jiachi MA ; Quan CHEN ; Yuanhui GU ; Yiping LI ; Wei FANG ; Meiling LIU ; Xiaochang CHEN ; Qingjin GUO ; Shixun MA
Chinese Journal of Oncology 2015;37(11):810-815
OBJECTIVETo explore the effect of colon cancer cell-derived interleukin-1α on the migration and proliferation of human umbilical vein endothelial cells as well as the role of IL-1α and IL-1ra in the angiogenesis process.
METHODSWestern blot was used to detect the expression of IL-1α and IL-1R1 protein in the colon cancer cell lines with different liver metastatic potential. We also examined how IL-1α and IL-1ra influence the proliferation and migration of umbilical vascular endothelial cells assessed by PreMix WST-1 assay and migration assay, respectively. Double layer culture technique was used to detect the effect of IL-1α on the proliferation and migration of vascular endothelial cells and the effect of IL-1ra on the vascular endothelial cells.
RESULTSWestern blot analysis showed that IL-1α protein was only detected in highly metastatic colon cancer HT-29 and WiDr cells, but not in the lowly metastatic CaCo-2 and CoLo320 cells.Migration assay showed that there were significant differences in the number of penetrated cells between the control (17.9±3.6) and 1 ng/ml rIL-1α group (23.2±4.2), 10 ng/ml rIL-1α group (31.7±4.5), and 100 ng/ml rIL-1α group (38.6±4.9), showing that it was positively correlated with the increasing concentration of rIL-1α (P<0.01 for all). The proliferation assay showed that the absorbance values were 1.37±0.18 in the control group, and 1.79±0.14 in the 1 ng/ml rIL-1α group, 2.14±0.17 in the 10 ng/ml rIL-1α group, and 2.21±0.23 in the 100 ng/ml rIL-1α group, showing a positive correlation with the increasing concentration of rIL-1α(P<0.01 for all). IL-1ra significantly inhibited the proliferation and migration of vascular endothelial cells (P<0.01). The levels of VEGF protein were (1.697±0.072) ng/ml, (3.507±0.064)ng/ml and (4.139±0.039)ng/ml in the control, HUVECs+ IL-1α and HUVECs+ HT-29 co-culture system groups, respectively, showing a significant difference between the control and HUVECs+ 10 pg/ml rIL-1α groups and between the control and HUVECs+ HT-29 groups (P<0.01 for both).
CONCLUSIONSOur findings indicate that colon cancer cell-derived IL-1α plays an important role in the liver metastasis of colon cancer through increased VEGF level of the colon cancer cells and enhanced vascular endothelial cells proliferation, migration and angiogenesis, while IL-1ra can suppress the effect of IL-1α and inhibit the angiogenesis in colon cancer.
Blotting, Western ; Caco-2 Cells ; Cell Line, Tumor ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Coculture Techniques ; Colonic Neoplasms ; blood supply ; metabolism ; pathology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Interleukin 1 Receptor Antagonist Protein ; metabolism ; physiology ; Interleukin-1alpha ; metabolism ; physiology ; Liver Neoplasms ; secondary ; Neovascularization, Pathologic ; etiology
5.Therapeutic Effects of Umbilical Cord Blood Derived Mesenchymal Stem Cell-Conditioned Medium on Pulmonary Arterial Hypertension in Rats.
Jae Chul LEE ; Choong Ik CHA ; Dong Sik KIM ; Soo Young CHOE
Journal of Pathology and Translational Medicine 2015;49(6):472-480
		                        		
		                        			
		                        			BACKGROUND: Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) may have multiple therapeutic applications for cell based therapy including the treatment of pulmonary artery hypertension (PAH). As low survival rates and potential tumorigenicity of implanted cells could undermine the mesenchymal stem cell (MSC) cell-based therapy, we chose to investigate the use of conditioned medium (CM) from a culture of MSC cells as a feasible alternative. METHODS: CM was prepared by culturing hUCB-MSCs in three-dimensional spheroids. In a rat model of PAH induced by monocrotaline, we infused CM or the control unconditioned culture media via the tail-vein of 6-week-old Sprague-Dawley rats. RESULTS: Compared with the control unconditioned media, CM infusion reduced the ventricular pressure, the right ventricle/(left ventricle+interventricular septum) ratio, and maintained respiratory function in the treated animals. Also, the number of interleukin 1alpha (IL-1alpha), chemokine (C-C motif) ligand 5 (CCL5), and tissue inhibitor of metalloproteinase 1 (TIMP-1)-positive cells increased in lung samples and the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling technique (TUNEL)-positive cells decreased significantly in the CM treated animals. CONCLUSIONS: From our in vivo data in the rat model, the observed decreases in the TUNEL staining suggest a potential therapeutic benefit of the CM in ameliorating PAH-mediated lung tissue damage. Increased IL-1alpha, CCL5, and TIMP-1 levels may play important roles in this regard.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Apoptosis
		                        			;
		                        		
		                        			Culture Media
		                        			;
		                        		
		                        			Culture Media, Conditioned
		                        			;
		                        		
		                        			Deoxyuridine
		                        			;
		                        		
		                        			Fetal Blood*
		                        			;
		                        		
		                        			Gene Expression
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Hypertension*
		                        			;
		                        		
		                        			In Situ Nick-End Labeling
		                        			;
		                        		
		                        			Interleukin-1alpha
		                        			;
		                        		
		                        			Lung
		                        			;
		                        		
		                        			Mesenchymal Stromal Cells
		                        			;
		                        		
		                        			Models, Animal
		                        			;
		                        		
		                        			Monocrotaline
		                        			;
		                        		
		                        			Pulmonary Artery
		                        			;
		                        		
		                        			Rats*
		                        			;
		                        		
		                        			Rats, Sprague-Dawley
		                        			;
		                        		
		                        			Survival Rate
		                        			;
		                        		
		                        			Tissue Inhibitor of Metalloproteinase-1
		                        			;
		                        		
		                        			Umbilical Cord*
		                        			;
		                        		
		                        			Ventricular Pressure
		                        			
		                        		
		                        	
6.Cigarette Smoke-Induced Interleukin-1 Alpha May Be Involved in the Pathogenesis of Adult Acne.
Yun Seok YANG ; Hee Kyeong LIM ; Kyung Kook HONG ; Min Kyung SHIN ; Jin Woo LEE ; Sung Won LEE ; Nack In KIM
Annals of Dermatology 2014;26(1):11-16
		                        		
		                        			
		                        			BACKGROUND: Lipid peroxide (LPO) in comedones, which are produced as a result of sebum oxidation, might potentially induce interleukin-1alpha (IL-1alpha) and exacerbate comedogenesis and inflammatory changes in comedones. OBJECTIVE: To investigate the relationship of proinflammatory cytokines and LPO levels in the extracts of comedones with the acne of clinical difference between smokers and non-smokers, and with the severity and distribution of the acne lesions. METHODS: Twenty-two non-smoking and 21 smoking adult acne patients were evaluated by comedone extraction and measurement of proinflammatory cytokines and LPO levels. Acne severity and distribution of the lesions were also analyzed. RESULTS: Relative to the non-smoking group, smokers had significantly higher levels of IL-1alpha and LPO in comedones. Their levels showed a positive correlation. However, there were no statistically significant difference between the severity or distribution of the disease and the levels of LPO and IL-1alpha in comedones. CONCLUSION: Smoking may be involved in the pathogenesis of adult acne by increasing the oxidative stress that results in subsequent accumulation of LPO in comedones.
		                        		
		                        		
		                        		
		                        			Acne Vulgaris*
		                        			;
		                        		
		                        			Adult*
		                        			;
		                        		
		                        			Cytokines
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Interleukin-1*
		                        			;
		                        		
		                        			Interleukin-1alpha*
		                        			;
		                        		
		                        			Oxidative Stress
		                        			;
		                        		
		                        			Sebum
		                        			;
		                        		
		                        			Smoke
		                        			;
		                        		
		                        			Smoking
		                        			;
		                        		
		                        			Tobacco Products*
		                        			
		                        		
		                        	
7.Microarray Analysis for Genes Associated with Angiogenesis in Diabetic OLETF Keratocytes.
Jun Mo PARK ; Young Min PARK ; Wook JUNG ; Ji Eun LEE ; Jong Soo LEE
Journal of Korean Medical Science 2014;29(2):265-271
		                        		
		                        			
		                        			The purpose of this study was to identify the differences in angiogenesis gene expression between normal and diabetic keratocytes stimulated with interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha). Primarily cultured normal and diabetic keratocytes were treated with 20 ng/mL of IL-1a and TNF-alpha for 6 hr. cDNA was hybridized to an oligonucleotide microarray. Microarray analysis was used to identify differentially expressed genes that were further evaluated by real-time polymerase chain reaction (RT-PCR). Diabetes keratocytes overexpressed vital components of angiogenesis including Agtr1, and under-expressed components related to the blood vessel maturation, including Dcn. Cytokine-treated diabetic keratocytes differentially expressed components of angiogenesis. OLETF keratocytes after treatment with IL-1alpha and TNF-alpha showed the newly expressed 15 and 14 genes, respectively. Newly and commonly under-expressed five genes followed by treatment with both IL-1alpha and TNF-alpha were also evident. RT-PCR showed results similar to the microarray results. Agtr1 and Itga1 showed an increased expression in diabetic keratocytes compared with normal corneal keratocytes, especially after TNF-alpha treatment. Il6 appeared strong expression after interleukin-1alpha treatment, but showed down expression after TNF-alpha treatment. Further studies to analyze and confirm the significance of the identified angiogenetic genes of diabetes are needed.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Cells, Cultured
		                        			;
		                        		
		                        			Gene Expression Regulation/drug effects
		                        			;
		                        		
		                        			Interleukin-1alpha/pharmacology
		                        			;
		                        		
		                        			Keratinocytes/cytology/drug effects/*metabolism
		                        			;
		                        		
		                        			Neovascularization, Physiologic/*genetics
		                        			;
		                        		
		                        			*Oligonucleotide Array Sequence Analysis
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Real-Time Polymerase Chain Reaction
		                        			;
		                        		
		                        			Receptor, Angiotensin, Type 1/genetics/metabolism
		                        			;
		                        		
		                        			Tumor Necrosis Factor-alpha/pharmacology
		                        			
		                        		
		                        	
8.Dynamic changes of a group of cytokines in phosgene-induced lung injury and the function of ulinastatin.
Jun LI ; Jing WANG ; Zhiyue ZHONG ; Daikun HE ; Jing ZHANG ; Jie SHEN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2014;32(11):813-818
OBJECTIVETo investigate the dynamic changes of a group of cytokines in phosgene-induced lung injury and the function of different dose of ulinastatin through animal experiment.
METHODS104 male SD rats were randomly assigned into the control group, ulinastatin control group, phosgene treatment groups and different dose of ulinastatin intervention groups, 8 rats each group. Treatment groups were dynamic constant exposure in phosgene, and immediately injected ulinastatin intraperitoneal, and then the experimental animal, the lung tissue biopsy, lung wet/dry ratio, RT-PCR detection, the plasma for detection of Bio-Plex 18 cytokines.
RESULTSCompared with the control group, plasma concentrations of IL-1α, IL-6, GM-CSF, TNF-α, INF-γ, MIP-3α, VEGF were increased significantly first (2 h), and gradually decreased with the passage of time , the difference was statistically significant (P < 0.05). Plasma concentrations of IL-4, IL-10 were decreased earlier (2h, 6 h) and increased later (24 h) (P < 0.05). The change of plasma concentration of IL-13 was not obvious earlier (2 h) and still rising later (24h), the difference was statistically significant (P < 0.05). After drug intervention, the levels of pro-inflammatory cytokines declined and the levels of anti-inflammatory cytokines raise by different degrees at different times in ulinastatin intervention groups, the difference was statistically significant. The degree of lung injury was improved than the phosgene treatment groups and better in high dose of ulinastatin intervention group. The expression of IL-10, IL-4, IL-13-mRNA of tissue increased in accordance with plasma results.
CONCLUSIONA group of cytokines are dynamicly changed in phosgene-induced lung injury by time. High dose of ulinastatin can improved phosgene-induced lung injury, regulate the synthesis and release of inflammatory cytokines and inhibit inflammatory react in a dose-dependent manner.
Animals ; Cytokines ; metabolism ; Glycoproteins ; pharmacology ; Granulocyte-Macrophage Colony-Stimulating Factor ; Interleukin-10 ; Interleukin-13 ; Interleukin-1alpha ; Interleukin-4 ; Interleukin-6 ; Lung ; Lung Injury ; chemically induced ; drug therapy ; Male ; Phosgene ; toxicity ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha
9.Cytotoxic effects of sodium dodecyl benzene sulfonate on human keratinocytes are not associated with proinflammatory cytokines expression.
Zhanglei MU ; Xiaojing LIU ; Yan ZHAO ; Jianzhong ZHANG
Chinese Medical Journal 2014;127(21):3777-3781
BACKGROUNDKeratinocytes play a crucial role in the biological function of skin barrier. The relationship between sodium lauryl sulfate (SLS) and keratinocytes has been studied. However, the cytotoxicity and effects of sodium dodecyl benzene sulfonate (SDBS), a common detergent similar to SLS, on keratinocytes are still not known. This study aimed to investigate the effects of SDBS on cytotoxicity and expression of proinflammatory cytokines in cultured human keratinocytes.
METHODSThis study was carried out using the keratinocytes cell line, HaCaT cells. The cytotoxicity of SDBS on HaCaT cells was evaluated with cell counting kit-8 (CCK-8) and phase-contrast microscopy. After exposure to different concentrations of SDBS, the total RNA of the HaCaT cells was extracted for evaluating the relative mRNA expression of IL-1α, IL-6, IL-8, and TNF-α by qPCR. The supernatants of cells were collected for measuring the levels of IL-6 and IL-8 by enzyme-linked immunosorbent assay (ELISA).
RESULTSSDBS at concentrations of 20 µg/ml and over showed direct cytotoxicity and induced morphological changes of the HaCaT cells. The mRNA expressions of IL-1α, IL-6, IL-8, and TNF-a in different concentrations of SDBS at different time were comparable with that of controls. SDBS at concentrations of 5, 10, and 15 µg/ml had no significant effects on IL-6 and IL-8 excretion from HaCaT cells after 24-hour exposure. Moreover, no significant effects on the IL-6 and IL-8 excretion were found after 10 and 15 µg/ml SDBS stimulations for 6, 12, and 24 hours, respectively.
CONCLUSIONSDBS at higher concentrations had cytotoxicity on HaCaT cells but had no effects on the mRNA expression of IL-1α, IL-6, IL-8, and TNF-a, that was different from SLS.
Benzenesulfonates ; pharmacology ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Humans ; Interleukin-1alpha ; metabolism ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Keratinocytes ; drug effects ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism
10.FSL-1, a Toll-like Receptor 2/6 Agonist, Induces Expression of Interleukin-1alpha in the Presence of 27-hydroxycholesterol.
Weon HEO ; Sun Mi KIM ; Seong Kug EO ; Byung Yong RHIM ; Koanhoi KIM
The Korean Journal of Physiology and Pharmacology 2014;18(6):475-480
		                        		
		                        			
		                        			We investigated the question of whether cholesterol catabolite can influence expression of inflammatory cytokines via Toll-like receptors (TLR) in monocytic cells. Treatment of THP-1 monocytic cells with 27-hydroxycholesterol (27OHChol) resulted in induction of gene transcription of TLR6 and elevated level of cell surface TLR6. Addition of FSL-1, a TLR6 agonist, to 27OHChol-treated cells resulted in transcription of the IL-1alpha gene and enhanced secretion of the corresponding gene product. However, cholesterol did not affect TLR6 expression, and addition of FSL-1 to cholesterol-treated cells did not induce expression of IL-1alpha . Using pharmacological inhibitors, we investigated molecular mechanisms underlying the expression of TLR6 and IL-1alpha. Treatment with Akt inhibitor IV or U0126 resulted in significantly attenuated expression of TLR6 and IL-1alpha induced by 27OHChol and 27OHChol plus FSL-1, respectively. In addition, treatment with LY294002, SB202190, or SP600125 resulted in significantly attenuated secretion of IL-1alpha . These results indicate that 27OHChol can induce inflammation by augmentation of TLR6-mediated production of IL-1alpha in monocytic cells via multiple signaling pathways.
		                        		
		                        		
		                        		
		                        			Cholesterol
		                        			;
		                        		
		                        			Cytokines
		                        			;
		                        		
		                        			Inflammation
		                        			;
		                        		
		                        			Interleukin-1
		                        			;
		                        		
		                        			Interleukin-1alpha*
		                        			;
		                        		
		                        			Toll-Like Receptors*
		                        			
		                        		
		                        	
            
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