PPARγ基因沉默对细胞炎症反应的调控作用
摘要
炎症,作为与人类多种疾患息息相关的病理过程而备受国际医学界的瞩目,目前仍是临床与基础医学研究的重要课题。业已研究证实,过度炎症反应是创伤后多种并发症,如脓毒症/脓毒性休克、急性呼吸窘迫综合征、多器官功能不全综合征等的重要病理基础。为此,我们已从效应细胞表面膜受体、细胞内信号通路、靶基因表达调控、效应细胞凋亡与炎症反应的关系四方面研究炎症反应的发生机制和关键的调控环节,并在此基础上寻找新的抗炎措施。近五年来,我们不仅在揭示创伤后炎症反应发生机制方面取得一定的进展,同时,研究发现,机体自身的抗炎保护效应机制也是影响炎症发生发展的重要因素。此外,我们研究发现,严重创伤早期,体内单核细胞合成促炎介质能力明显增强,但随后却明显受抑,细胞产生抗炎介质如IL-1Ra、IL-10 无明显减少。基于上述结果,我们认为,炎症应是一个促炎与抗炎反应相互依存、互为拮抗的复杂过程,伴随炎症产生的各种内源性抗炎保护效应机制固然是机体在炎症环境下得以维持内环境稳定的根本需要,但抗炎机制的失调,不仅是促使早期有限性保护性炎症反应转化为破坏性过度炎症反应的重要机制,同时也是造成创伤机体免疫力低下、对感染易感性增加的重要原因。然而,对于机体自身调控抗炎反应的机制,迄今尚鲜见文献报道。
近年研究发现,细胞内过氧化物酶体增殖物激活受体(peroxisome proliferator-activated receptors,PPARs)通过反式阻抑机制对细胞的促炎反应具有明显的抑制作用。PPARs 有三种异构体:PPARα、PPARβ/δ和PPARγ,在巨噬细胞、树突细胞、T细胞、B 细胞等广泛表达。早期研究认为,它们在调节脂质代谢方面发挥重要作用。近年研究发现,PPARs 也是调控炎症反应的关键点(checkpoint)。有关PPARγ抗炎作用研究发现:PPARγ激动剂能明显抑制炎性刺激诱导单核/巨噬细胞产生促炎细胞因子(TNFα、IL1、IL6、NO)的产生;PPARγ配体预处理野生型动物,能明显降低组织内促炎细胞因子的表达,减轻炎症局部和远隔部位的组织损伤,对多种实验性炎性疾病,如急性心肌炎、自身免疫性脑脊髓炎、多发性硬化等均显示较好的治疗作用;然而,PPARγ基因敲除可导致胚胎死亡,目前尚无PPARγ缺陷动物,仅有通过同源重组建立的PPARγ+/-嵌合小鼠模型。关于PPARγ对细胞其它抗炎保护效应的
Inflammation, the focus of international medical field, is closely related to various human diseases. It remains the fundamental topic in the basic research and clinical practice. Research has showed excessive inflammatory responses constitute the pathological basis of the multiple post-traumatic complications, such as sepsis/septic shock, acute respiratory distress syndrome and multiple organ dysfunction syndrome. So we have studied the mechanism and key controlling points in inflammatory responses from the membrane receptors in effector cells, intracellular signaling pathway expression and regulation of targeting gene, apoptosis of the effector cells, seeking anti-inflammatory measures. In the past five years, we have not only made progress in disclosing the mechanism of post-traumatic inflammatory responses, but also found that the self-protecting anti-inflammatory effects did influence the occurrence and progress of inflammation. In addition, research has demonstrated that the monocytes may secret more pro-inflammatory mediators in the early phase of severe injury, which is inhibited with time prolonged. The secretion of anti-inflammatory mediators, such as IL-1Ra, IL-10, has no obviously attenuation. In view of the above results, we speculate inflammation is a complicated course of mutual promotion and restraint between pro-and anti-inflammatory response. Although endogenous anti-inflammatory effects maintain the homeostasis, the disturbance of the mechanism of anti-inflammatory responses, not only promotes the transformation of inflammation from protecting stage to destructive outcome, but also results in the hypo-immunity of the injuring bodies, which is the reason for high sensitivity to infection. However, little is known about the self-regulating mechanism.
In recent years, basic and clinical studies have demonstrated peroxisome proliferator -activated receptor γ(PPARγ), belonging to the nuclear steroid receptor superfamily, suppresses the pro-inflammatory responses by transaction. PPARγis widely distributed in macrophages, dendritic cells, T cells, B cells and others. Previous researches have showed it plays an important role in lipid metabolism and glucose homeostasis. Recently, PPARγis also found to be the checkpoint in controlling inflammation. Research on the
anti-inflammatory effects of PPARγhas showed that its agonists obviously inhibit the secretion of pro-inflammatory mediators such as TNFα, IL1, IL6 and NO, in activated monocytes and macrophages. Pretreatment of wild-type mice with PPARγligands can decrease the expression of pro-inflammatory cytokines, alleviate the injury of local and distant tissues, which plays the therapeutic effect on many inflammatory diseases, such as acute myocarditis, autoimmune encephalitis and multiple sclerosis. Unfortunately, PPARγgene knockout have resulted in embryonic lethality because of placental dysfunction. Heterozygous mice (PPARγ+/-) used to investigate the role of PPARγshowed some limitation because lower levels of PPARγremains regulating diverse cellular processes in cells. On account of its distinctive action, transacting various transcription factors and/or cytoplasmic co-factors, we think that PPARγmodulates not only the synthesis of pro-inflammatory mediators, but also the production of anti-inflammatory mediators, which is the key checkpoint in keeping the balance of pro-and anti-inflammatory responses. RNA interference (RNAi), a powerful technique for selectively silencing the expression of genes, is firstly discovered in threadworms by Fire et al, followed by the detection in fruit fly, insects, plants and mammals. In RNAi pathway, double-stranded RNA (dsRNA) is cleaved into fragments of 21-25 nt, which degrades the sequence-specific mRNA facing the target mRNA of cognate complementary sequences, causing the post-transcriptional gene silencing (PTGS). Experimental cells show the phenotype of specific gene deletion. As an operative simple technique instead of gene knockout, it is easy to operate and economical. Compared to the antisense technology, the suppression on the targeting genes is more specific and more efficient. So research on the candidate gene function and gene therapy by RNAi technique has become the hot spot in life science nowadays. In view of the behavior of PPARγon various key transcriptional factors, this research firstly investigates the dynamic expression of PPARγ, then, constructs the recombinant pSUPER.EGFP vectors including the inserts of PPARγtargeting sequences. Finally, observes the silencing effect of PPARγsiRNA on the macrophage cell line RAW264.7. On this basis, we further studied the mechanism of PPARγon inflammatory response, especially that of signal transduction of cellular anti-inflammatory effect, in order to further elucidate the role of PPARγin controlling the dynamic equilibrium between pro-and anti-inflammatory responses, and disclose the mechanism of self anti-inflammation in order
to supply a new idea for research on inflammation. The main results are as follows, 1. LPS up-regulates the PPARγexpression of macrophage cell line RAW264.7, mainly the cytoplasmic part, in a time-dependant manner. The changes of PPARγin the nucleus is less evident expect the down-regulation in 16 hours of LPS stimulation. During the course of observation, the protein ratio of cytoplasmic PPARγto nuclear PPARγshows the tendency of up-regulation. 2. Curcumin stimulates the expression of cytoplasmic PPARγprotein drastically in RAW264.7 cells, while the nuclear PPARγpart is also up-regulated. The protein ratio of cytoplasmic PPARγto nuclear PPARγshows the tendency of up-regulation. 3. After pretreatment of RAW264.7 cells with curcumin, LPS stimulation has increased the amount of PPARγprotein either in the cytoplasm or in the nucleus. Also, the nuclear PPARγprotein is more than that of LPS group in the time point of 12th,16th and 24th hour. The protein ratio of cytoplasmic PPARγto nuclear PPARγalso shows the tendency of up-regulation. 4. In constructing the recombinant plasmids for RNA interference, four kinds of PPARγ-pSUPER-EGFP have been constructed successively by optimizing the selection of targeting sequences and the condition of construction, which knock down the PPARγexpression at the level of transcription and translation in RAW264.7 cells differently. Among them, PPARγ-pSUPER-EGFP2 is most efficient. 5. The expression of phosphor-p42/44 MAPK increased drastically after LPS stimulation. The PPARγgene silencing has no effect on this course. However, the expression of IkappaB-alpha attenuated dramatically after LPS stimulation, while the PPARγgene silencing further strengthened the degradation of IkappaB-alpha. After PPARγgene silencing, curcumin have inhibited the degradation of IkappaB-alpha to some extent following LPS stimulation. 6. The level of TNFαand IL-1Ra increased after LPS stimulation. The peak of TNFαis ahead of that of IL-1Ra. Curcumin has decreased the TNFαlevel. After PPARγgene silencing, the inhibition of curcumin on TNFαexpression becomes mild. Different doses of rosiglitazone have inhibited the TNFαexpression with or without the PPARγgene silencing. 7. Curcumin has no significant effect on the IL-1Ra level in RAW264.7 cells after LPS
stimulation. No difference is found between pre-and post-gene silencing of PPARγ. Different doses of rosiglitazone have increased the IL-1Ra level. After 8 hours of LPS stimulation, the expression of IL-1Ra is more than that of control group, but PPARγgene silencing has no effect on this course. Conclusions 1. The PPARγexpression of macrophage cell line RAW264.7 is mainly located in the cytoplasm. Curcumin not only has up-regulated its expression and accelerated the translocation of PPARγprotein from cytoplasm to nucleus, but also reversed the inhibitory effect of translocation of PPARγprotein from cytoplasm to nucleus induced by LPS. The modulation of the PPARγexpression and its nuclear-cytoplasmic shuttling may be the key point of controlling the inflammation. 2. In constructing the recombinant plasmids for RNA interference, the optimization of the selection of targeting sequences and the condition of construction serves the plasmid-induced RNAi research. The efficient PPARγ-pSUPER-EGFP not only establishes the basis for the construction of PPARγdeficient cell line, but also supplies the cell model for the research on the PPARγgene function and gene therapy in corresponding diseases. 3. The anti-inflammatory responses induced by PPARγdoesn’t change the activation of ERK signaling, but may attenuate the phosphorylation and degradation of IkappaB-alpha, and inhibit the activation and translocation of NF-κB. The PPAR γdependant anti-inflammatory responses induced by curcumin includes the antagonism on NF-κB signaling. Also, PPARγmay not be the only effector molecule. Other signal molecules in the downstream probably plays an anti-inflammatory role in a PPARγindependent manner. PPARγbelongs to one of the targeting molecules when curcumin works. 4. The pro-and anti-inflammatory responses maybe works consequently in RAW264.7 cells. The PPARγexpression induced by curcumin is negatively related to the TNFαlevel after LPS stimulation, but has no relationship with the IL-1Ra level. The PPARγligand rosiglitazone stimulates the expression of IL-1Ra in a PPARγindependent manner. The synergistic anti-inflammatory strategy with curcumin and rosiglitazone may be more efficient in controlling the macrophage inflammation.
近年研究发现,细胞内过氧化物酶体增殖物激活受体(peroxisome proliferator-activated receptors,PPARs)通过反式阻抑机制对细胞的促炎反应具有明显的抑制作用。PPARs 有三种异构体:PPARα、PPARβ/δ和PPARγ,在巨噬细胞、树突细胞、T细胞、B 细胞等广泛表达。早期研究认为,它们在调节脂质代谢方面发挥重要作用。近年研究发现,PPARs 也是调控炎症反应的关键点(checkpoint)。有关PPARγ抗炎作用研究发现:PPARγ激动剂能明显抑制炎性刺激诱导单核/巨噬细胞产生促炎细胞因子(TNFα、IL1、IL6、NO)的产生;PPARγ配体预处理野生型动物,能明显降低组织内促炎细胞因子的表达,减轻炎症局部和远隔部位的组织损伤,对多种实验性炎性疾病,如急性心肌炎、自身免疫性脑脊髓炎、多发性硬化等均显示较好的治疗作用;然而,PPARγ基因敲除可导致胚胎死亡,目前尚无PPARγ缺陷动物,仅有通过同源重组建立的PPARγ+/-嵌合小鼠模型。关于PPARγ对细胞其它抗炎保护效应的
Inflammation, the focus of international medical field, is closely related to various human diseases. It remains the fundamental topic in the basic research and clinical practice. Research has showed excessive inflammatory responses constitute the pathological basis of the multiple post-traumatic complications, such as sepsis/septic shock, acute respiratory distress syndrome and multiple organ dysfunction syndrome. So we have studied the mechanism and key controlling points in inflammatory responses from the membrane receptors in effector cells, intracellular signaling pathway expression and regulation of targeting gene, apoptosis of the effector cells, seeking anti-inflammatory measures. In the past five years, we have not only made progress in disclosing the mechanism of post-traumatic inflammatory responses, but also found that the self-protecting anti-inflammatory effects did influence the occurrence and progress of inflammation. In addition, research has demonstrated that the monocytes may secret more pro-inflammatory mediators in the early phase of severe injury, which is inhibited with time prolonged. The secretion of anti-inflammatory mediators, such as IL-1Ra, IL-10, has no obviously attenuation. In view of the above results, we speculate inflammation is a complicated course of mutual promotion and restraint between pro-and anti-inflammatory response. Although endogenous anti-inflammatory effects maintain the homeostasis, the disturbance of the mechanism of anti-inflammatory responses, not only promotes the transformation of inflammation from protecting stage to destructive outcome, but also results in the hypo-immunity of the injuring bodies, which is the reason for high sensitivity to infection. However, little is known about the self-regulating mechanism.
In recent years, basic and clinical studies have demonstrated peroxisome proliferator -activated receptor γ(PPARγ), belonging to the nuclear steroid receptor superfamily, suppresses the pro-inflammatory responses by transaction. PPARγis widely distributed in macrophages, dendritic cells, T cells, B cells and others. Previous researches have showed it plays an important role in lipid metabolism and glucose homeostasis. Recently, PPARγis also found to be the checkpoint in controlling inflammation. Research on the
anti-inflammatory effects of PPARγhas showed that its agonists obviously inhibit the secretion of pro-inflammatory mediators such as TNFα, IL1, IL6 and NO, in activated monocytes and macrophages. Pretreatment of wild-type mice with PPARγligands can decrease the expression of pro-inflammatory cytokines, alleviate the injury of local and distant tissues, which plays the therapeutic effect on many inflammatory diseases, such as acute myocarditis, autoimmune encephalitis and multiple sclerosis. Unfortunately, PPARγgene knockout have resulted in embryonic lethality because of placental dysfunction. Heterozygous mice (PPARγ+/-) used to investigate the role of PPARγshowed some limitation because lower levels of PPARγremains regulating diverse cellular processes in cells. On account of its distinctive action, transacting various transcription factors and/or cytoplasmic co-factors, we think that PPARγmodulates not only the synthesis of pro-inflammatory mediators, but also the production of anti-inflammatory mediators, which is the key checkpoint in keeping the balance of pro-and anti-inflammatory responses. RNA interference (RNAi), a powerful technique for selectively silencing the expression of genes, is firstly discovered in threadworms by Fire et al, followed by the detection in fruit fly, insects, plants and mammals. In RNAi pathway, double-stranded RNA (dsRNA) is cleaved into fragments of 21-25 nt, which degrades the sequence-specific mRNA facing the target mRNA of cognate complementary sequences, causing the post-transcriptional gene silencing (PTGS). Experimental cells show the phenotype of specific gene deletion. As an operative simple technique instead of gene knockout, it is easy to operate and economical. Compared to the antisense technology, the suppression on the targeting genes is more specific and more efficient. So research on the candidate gene function and gene therapy by RNAi technique has become the hot spot in life science nowadays. In view of the behavior of PPARγon various key transcriptional factors, this research firstly investigates the dynamic expression of PPARγ, then, constructs the recombinant pSUPER.EGFP vectors including the inserts of PPARγtargeting sequences. Finally, observes the silencing effect of PPARγsiRNA on the macrophage cell line RAW264.7. On this basis, we further studied the mechanism of PPARγon inflammatory response, especially that of signal transduction of cellular anti-inflammatory effect, in order to further elucidate the role of PPARγin controlling the dynamic equilibrium between pro-and anti-inflammatory responses, and disclose the mechanism of self anti-inflammation in order
to supply a new idea for research on inflammation. The main results are as follows, 1. LPS up-regulates the PPARγexpression of macrophage cell line RAW264.7, mainly the cytoplasmic part, in a time-dependant manner. The changes of PPARγin the nucleus is less evident expect the down-regulation in 16 hours of LPS stimulation. During the course of observation, the protein ratio of cytoplasmic PPARγto nuclear PPARγshows the tendency of up-regulation. 2. Curcumin stimulates the expression of cytoplasmic PPARγprotein drastically in RAW264.7 cells, while the nuclear PPARγpart is also up-regulated. The protein ratio of cytoplasmic PPARγto nuclear PPARγshows the tendency of up-regulation. 3. After pretreatment of RAW264.7 cells with curcumin, LPS stimulation has increased the amount of PPARγprotein either in the cytoplasm or in the nucleus. Also, the nuclear PPARγprotein is more than that of LPS group in the time point of 12th,16th and 24th hour. The protein ratio of cytoplasmic PPARγto nuclear PPARγalso shows the tendency of up-regulation. 4. In constructing the recombinant plasmids for RNA interference, four kinds of PPARγ-pSUPER-EGFP have been constructed successively by optimizing the selection of targeting sequences and the condition of construction, which knock down the PPARγexpression at the level of transcription and translation in RAW264.7 cells differently. Among them, PPARγ-pSUPER-EGFP2 is most efficient. 5. The expression of phosphor-p42/44 MAPK increased drastically after LPS stimulation. The PPARγgene silencing has no effect on this course. However, the expression of IkappaB-alpha attenuated dramatically after LPS stimulation, while the PPARγgene silencing further strengthened the degradation of IkappaB-alpha. After PPARγgene silencing, curcumin have inhibited the degradation of IkappaB-alpha to some extent following LPS stimulation. 6. The level of TNFαand IL-1Ra increased after LPS stimulation. The peak of TNFαis ahead of that of IL-1Ra. Curcumin has decreased the TNFαlevel. After PPARγgene silencing, the inhibition of curcumin on TNFαexpression becomes mild. Different doses of rosiglitazone have inhibited the TNFαexpression with or without the PPARγgene silencing. 7. Curcumin has no significant effect on the IL-1Ra level in RAW264.7 cells after LPS
stimulation. No difference is found between pre-and post-gene silencing of PPARγ. Different doses of rosiglitazone have increased the IL-1Ra level. After 8 hours of LPS stimulation, the expression of IL-1Ra is more than that of control group, but PPARγgene silencing has no effect on this course. Conclusions 1. The PPARγexpression of macrophage cell line RAW264.7 is mainly located in the cytoplasm. Curcumin not only has up-regulated its expression and accelerated the translocation of PPARγprotein from cytoplasm to nucleus, but also reversed the inhibitory effect of translocation of PPARγprotein from cytoplasm to nucleus induced by LPS. The modulation of the PPARγexpression and its nuclear-cytoplasmic shuttling may be the key point of controlling the inflammation. 2. In constructing the recombinant plasmids for RNA interference, the optimization of the selection of targeting sequences and the condition of construction serves the plasmid-induced RNAi research. The efficient PPARγ-pSUPER-EGFP not only establishes the basis for the construction of PPARγdeficient cell line, but also supplies the cell model for the research on the PPARγgene function and gene therapy in corresponding diseases. 3. The anti-inflammatory responses induced by PPARγdoesn’t change the activation of ERK signaling, but may attenuate the phosphorylation and degradation of IkappaB-alpha, and inhibit the activation and translocation of NF-κB. The PPAR γdependant anti-inflammatory responses induced by curcumin includes the antagonism on NF-κB signaling. Also, PPARγmay not be the only effector molecule. Other signal molecules in the downstream probably plays an anti-inflammatory role in a PPARγindependent manner. PPARγbelongs to one of the targeting molecules when curcumin works. 4. The pro-and anti-inflammatory responses maybe works consequently in RAW264.7 cells. The PPARγexpression induced by curcumin is negatively related to the TNFαlevel after LPS stimulation, but has no relationship with the IL-1Ra level. The PPARγligand rosiglitazone stimulates the expression of IL-1Ra in a PPARγindependent manner. The synergistic anti-inflammatory strategy with curcumin and rosiglitazone may be more efficient in controlling the macrophage inflammation.
引文
1. 黎鳌, 盛志勇, 王正国主编. 现代战伤外科学. 第一版. 北京: 人民军医出版社,1998,284-298.
2. 盛志勇, 胡森主编. 多脏器功能障碍综合征. 第一版. 北京: 科学出版社, 1999,11-59.
3. 蒋建新主编. 细菌内毒素基础与临床. 第一版. 北京: 人民军医出版社, 2004, 73-86.
4. Reddy RC, Keshamouni VG, Jaigirdar SH, et al. Deactivation of murine alveolar macrophages by peroxisome proliferator-activated receptor-gamma ligands. Am J Physiol Lung Cell Mol Physiol. 2004, 286(3): L613-L619.
5. Hong G, Davis B, Khatoon N, et al. PPAR gamma-dependent anti-inflammatory action of rosiglitazone in human monocytes: suppression of TNF alpha secretion is not mediated by PTEN regulation. Biochem Biophys Res Commun. 2003, 303(3): 782-787.
6. Alleva DG, Johnson EB, Lio FM, et al. Regulation of murine macrophage proinflammatory and anti-inflammatory cytokines by ligands for peroxisome proliferator-activated receptor-gamma: counter-regulatory activity by IFN-gamma. J Leukoc Biol. 2002, 71(4): 677-685.
7. Guyton K, Zingarelli B, Ashton S, et al. Peroxisome proliferator-activated receptor-gamma agonists modulate macrophage activation by gram-negative and gram-positive bacterial stimuli. Shock. 2003, 20(1): 56-62.
8. Hinz B, Brune K, Pahl A, 15-Deoxy-Delta(12,14)-prostaglandin J2 inhibits the expression of proinflammatory genes in human blood monocytes via a PPAR-gamma-independent mechanism. Biochem Biophys Res Commun. 2003,302(2): 415-420.
9. Giri S, Rattan R, Singh AK, er al. The 15-deoxy-delta12,14-prostaglandin J2 inhibits the inflammatory response in primary rat astrocytes via down-regulating multiple steps in phosphatidylinositol 3-kinase-Akt-NF-kappaB-p300 pathway independent of peroxisome proliferator-activated receptor gamma. J Immunol. 2004, 173(8): 5196-5208.
10. Brouet I, Ohshima H. Curcumin, an anti-tumour promoter and anti-inflammatory agent, inhibits induction of nitric oxide synthase in activated macrophages. Biochem Biophys
Res Commun 1995, 206(2), 533-540.
11. Liontas A, Yeger H, et al. Curcumin and resveratrol induce apoptosis and nuclear translocation and activation of p53 in human neuroblastoma. Anticancer Res. 2004, 24(2B): 987-998.
12. Chuang SE, Cheng AL, Lin JK, et al. Inhibition by curcumin of diethylnitrosamine-induced hepatic hyperplasia, inflammation, cellular gene products and cell-cycle-related proteins in rats. Food Chem Toxicol. 2000, 38(11): 991-995.
13. Shizhong ZHENG, Anping CHEN. Activation of PPARγis required for curcumin to induce apoptosis and to inhibit the expression of extracellular matrix genes in hepatic stellate cells in vitro. J Biochem. 2004, 384(2):149–157.
14. Pratsinis H, Giannouli CC, Zervolea I, et al. Differential proliferative response of fetal and adult human skin fibroblasts to transforming growth factor-beta. Wound Repair Regen. 2004, 12(3): 374-383.
15. Madan B, Ghosh B. Diferuloylmethane inhibits neutrophil infiltration and improves survival of mice in high-dose endotoxin shock, Shock, 2003, 19(1): 91-96.
16. Jianye Xu, Yumei Fu, Anping Chen. Activation of peroxisome proliferator-activated receptor-γcontributes to the inhibitory effects of curcumin on rat hepatic stellate cell growth. Am J Physiol Gastrointest Liver Physiol. 2003, 285(2): G20–G30.
2. 盛志勇, 胡森主编. 多脏器功能障碍综合征. 第一版. 北京: 科学出版社, 1999,11-59.
3. 蒋建新主编. 细菌内毒素基础与临床. 第一版. 北京: 人民军医出版社, 2004, 73-86.
4. Reddy RC, Keshamouni VG, Jaigirdar SH, et al. Deactivation of murine alveolar macrophages by peroxisome proliferator-activated receptor-gamma ligands. Am J Physiol Lung Cell Mol Physiol. 2004, 286(3): L613-L619.
5. Hong G, Davis B, Khatoon N, et al. PPAR gamma-dependent anti-inflammatory action of rosiglitazone in human monocytes: suppression of TNF alpha secretion is not mediated by PTEN regulation. Biochem Biophys Res Commun. 2003, 303(3): 782-787.
6. Alleva DG, Johnson EB, Lio FM, et al. Regulation of murine macrophage proinflammatory and anti-inflammatory cytokines by ligands for peroxisome proliferator-activated receptor-gamma: counter-regulatory activity by IFN-gamma. J Leukoc Biol. 2002, 71(4): 677-685.
7. Guyton K, Zingarelli B, Ashton S, et al. Peroxisome proliferator-activated receptor-gamma agonists modulate macrophage activation by gram-negative and gram-positive bacterial stimuli. Shock. 2003, 20(1): 56-62.
8. Hinz B, Brune K, Pahl A, 15-Deoxy-Delta(12,14)-prostaglandin J2 inhibits the expression of proinflammatory genes in human blood monocytes via a PPAR-gamma-independent mechanism. Biochem Biophys Res Commun. 2003,302(2): 415-420.
9. Giri S, Rattan R, Singh AK, er al. The 15-deoxy-delta12,14-prostaglandin J2 inhibits the inflammatory response in primary rat astrocytes via down-regulating multiple steps in phosphatidylinositol 3-kinase-Akt-NF-kappaB-p300 pathway independent of peroxisome proliferator-activated receptor gamma. J Immunol. 2004, 173(8): 5196-5208.
10. Brouet I, Ohshima H. Curcumin, an anti-tumour promoter and anti-inflammatory agent, inhibits induction of nitric oxide synthase in activated macrophages. Biochem Biophys
Res Commun 1995, 206(2), 533-540.
11. Liontas A, Yeger H, et al. Curcumin and resveratrol induce apoptosis and nuclear translocation and activation of p53 in human neuroblastoma. Anticancer Res. 2004, 24(2B): 987-998.
12. Chuang SE, Cheng AL, Lin JK, et al. Inhibition by curcumin of diethylnitrosamine-induced hepatic hyperplasia, inflammation, cellular gene products and cell-cycle-related proteins in rats. Food Chem Toxicol. 2000, 38(11): 991-995.
13. Shizhong ZHENG, Anping CHEN. Activation of PPARγis required for curcumin to induce apoptosis and to inhibit the expression of extracellular matrix genes in hepatic stellate cells in vitro. J Biochem. 2004, 384(2):149–157.
14. Pratsinis H, Giannouli CC, Zervolea I, et al. Differential proliferative response of fetal and adult human skin fibroblasts to transforming growth factor-beta. Wound Repair Regen. 2004, 12(3): 374-383.
15. Madan B, Ghosh B. Diferuloylmethane inhibits neutrophil infiltration and improves survival of mice in high-dose endotoxin shock, Shock, 2003, 19(1): 91-96.
16. Jianye Xu, Yumei Fu, Anping Chen. Activation of peroxisome proliferator-activated receptor-γcontributes to the inhibitory effects of curcumin on rat hepatic stellate cell growth. Am J Physiol Gastrointest Liver Physiol. 2003, 285(2): G20–G30.