36 research outputs found
Heparan Sulfate Regulates the Antiangiogenic Activity of Endothelial Monocyte-Activating Polypeptide-II at Acidic pH
ABSTRACT Endothelial monocyte-activating polypeptide-II (EMAP II) is an antiangiogenic factor for rapidly growing endothelial cells that is released from tumor cells under physiological stress such as hypoxia. We have previously shown that the interaction between EMAP II and the ␣-subunit of ATP synthase, ␣-ATP synthase, can play a regulatory function in the growth of endothelial cells. In the current study, we found that EMAP II-␣-ATP synthase interaction could be inhibited by excess heparin, whereas the interaction could be enhanced by a low concentration of heparin. Both EMAP II and ␣-ATP synthase could specifically interact with heparin, and this interaction was increased under acidic conditions. In addition, EMAP II and ␣-ATP synthase were found to contain the heparin binding motifs determined by analysis using site-directed mutant forms. In endothelial cells, binding of EMAP II to cells was dramatically enhanced, and ␣-ATP synthase could associate with heparan sulfate at acidic pH. The inhibitory effect of EMAP II on the growth of cultured endothelial cells was also significantly enhanced at acidic pH. Analysis using mutant EMAP II proteins demonstrated that heparan sulfate was essential for the enhanced binding and EMAP II function to endothelial cells at acidic pH. Furthermore, the enhanced inhibitory effects of EMAP II could be abrogated by excess heparin or heparinase treatment. In the endothelial cell, heparan sulfate may regulate the function of EMAP II released from the tumor cell in hypoxic condition
Sopungyangjae-Tang Inhibits Development of Dermatitis in Nc/Nga Mice
Sopungyangjae-Tang (SYT) is a traditional Korean decoction used for the treatment of dermatitis. The aim of this study was to confirm whether or not SYT has a preventive effect on the development of atopic dermatitis in dinitrochlorobenzene-applied Nc/Nga mice. SYT was administered orally to Nc/Nga mice, which led to the remarkable suppression of the development of dermatitis, as determined by a histological examination and the serum IgE levels. Moreover, SYT inhibited the production of thymus- and activation-regulated chemokine (TARC) and its mRNA expression in a keratinocyte cell line, HaCaT, which had been stimulated with tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Activation of the nuclear factor-κB (NF-κB) or activator protein-1 (AP-1) is one of the key steps in the signaling pathways mediating induction of TARC. In this study, SYT selectively suppressed NF-κB activation, which may be essential for TARC expression in TNF-α/IFN-γ treated keratinocytes. The inhibitory effect of SYT on NF-κB activation and TARC production might be associated with the anti-dermatitic effects of SYT
Celastrol regulates psoriatic inflammation and autophagy by targeting IL-17A
Anti-IL-17A antibodies, such as secukinumab and ixekizumab, are effective proinflammatory cytokine inhibitors for autoimmune disorders, including psoriasis. However, anti-IL-17A small molecule treatments are yet to be commercialized. Celastrol, a natural compound extracted from the roots of traditional Chinese medicinal plants, has anti-inflammatory and antioxidant properties. However, the binding of celastrol to IL-17A and the associated anti-inflammatory mechanisms remain unclear. This study investigated whether celastrol could directly bind to IL-17A and regulate inflammation in psoriatic in vitro and in vivo models. The results showed that celastrol directly binds to IL-17A and inhibits its downstream signaling, including the NF-kB and MAPK pathways. Interestingly, celastrol restored autophagy dysfunction and reduced proinflammatory cytokine secretion in keratinocytes. In addition, celastrol increased autophagy in the epidermis of a mouse model of psoriasis. Celastrol decreased Th17 cell populations and proinflammatory cytokine levels in mice. Thus, IL-17A-targeting celastrol reduced inflammation by rescuing impaired autophagy in in vitro and in vivo models of psoriasis, demonstrating its potential as a substitute for anti-IL-17A antibodies for treating psoriasis
Long Noncoding RNA E2F4as Promotes Progression and Predicts Patient Prognosis in Human Ovarian Cancer
(1) Background: LncRNAs could be a promising biomarker to predict the prognosis of various cancers. The significance of E2F4antisense lncRNA remains unclear in cancer. In this study, we examined the expression level of E2F4as in the serum of ovarian cancer patients and the functional role of E2F4as. (2) Methods: Serum samples were obtained from 108 OC patients and 32 normal patients to measure the expression of E2F4as in the serum. Ovarian cancer cells were used to investigate the role of E2F4as in cell proliferation, invasion, migration and apoptosis, and the expression of E2F4as was knocked down using RNA interference. In addition, E2F4as knockdown cell lines were used in in vivo experiments. (3) Results: The expression of E2F4as was significantly higher in the serum of OC patients than in that of control patients (p < 0.05). The knockdown of E2F4as in ovarian cancer cells led to a decrease in cell proliferation, invasion and migration and an increase in apoptosis. E2F4as knockdown also reduced the expression of epithelium–mesenchymal metastasis (EMT) genes. (4) Conclusion: These findings highlight the clinical significance of E2F4as in predicting the prognosis of OC patients and suggest its potential in promoting tumour aggressiveness by the regulation of EMT-related mechanisms
Pravastatin and Sarpogrelate Synergistically Ameliorate Atherosclerosis in LDLr-Knockout Mice.
Pravastatin is a lipid-lowering agent that attenuates atherosclerosis. However, the multifactorial pathogenesis of atherosclerosis requires other drugs with different anti-atherogenic mechanisms. We chose sarpogrelate as an anti-platelet agent and a novel component of a complex drug with pravastatin due to its high potential but little information on its beneficial effects on atherosclerosis. Low-density lipoprotein receptor-knockout mice were fed a high-fat, high-cholesterol diet and treated with pravastatin alone, sarpogrelate alone, or a combination of both drugs. Although sarpogrelate alone did not significantly reduce atherosclerotic plaque areas, co-treatment with pravastatin significantly decreased aortic lesions compared to those of the pravastatin alone treated group. The combined therapy was markedly more effective than that of the single therapies in terms of foam cell formation, smooth muscle cell proliferation, and inflammatory cytokine levels. These results suggest that pravastatin and sarpogrelate combined therapy may provide a new therapeutic strategy for treating atherosclerosis
LncRNA SNHG4 Modulates EMT Signal and Antitumor Effects in Endometrial Cancer through Transcription Factor SP-1
Long non-coding RNAs (lncRNAs) are implicated in the initiation and progression of a variety of tumors, including endometrial cancer. However, the mechanisms of lncRNA in endometrial cancer formation and progression remain largely unknown. In this study, we confirmed that the lncRNA SNHG4 is upregulated in endometrial cancer and correlates with lower survival rates in endometrial cancer patients. Knock-down of SNHG4 significantly reduced cell proliferation, colonization, migration, and invasion in vitro, as well as modulating the cell cycle and reduced tumor growth of endometrial cancer in vivo. In addition, the effect of SNHG4 by the transcription factor SP-1 was confirmed in vitro. We found in this study that SNHG4/SP-1 plays an important role in endometrial cancer progression and may be used as a potential therapeutic and prognostic biomarker for endometrial cancer
Normalization of the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells by fibrate pretreatment
BACKGROUND: Tuberculosis (TB) is a respiratory tract disease caused by Mycobacterium tuberculosis infection. M. tuberculosis exploits immune privilege to grow and divide in pleural macrophages. Fibrates are associated with the immune response and control lipid metabolism through glycolysis with β-oxidation of fatty acids. RESULTS: In this study, we investigated the effect of fibrate pretreatment on the immune response during M. smegmatis infection in U937 cells, a human leukemic monocyte lymphoma cell line. The protein expression of tumor necrosis factor α (TNF-α), an inflammatory marker, and myeloid differentiation primary response gene 88 (MyD88), a toll like receptor adaptor molecule, in the infected group increased at 1 and 6 h after M. smegmatis infection of U937 cells. Acetyl coenzyme A acetyl transferase-1 (ACAT-1), peroxisome proliferator-activated receptor-α (PPAR-α), TNF-α, and MyD88 decreased in U937 cells treated with fibrates at 12 and 24 h after treatment. More than a 24 h pretreatment with fibrate resulted in similar expression levels of ACAT-1 and PPAR-α between infected vehicle control and infected groups which were pretreated with fibrate for 24 h. However, upon exposure to M. smegmatis, the cellular expression of the TNF-α and MyD88 in the infected groups pretreated with fibrate for 24 h decreased significantly compared to that in the infected vehicle group. CONCLUSION: These results suggest that fibrate pretreatment normalized the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells. Further studies are needed to confirm the findings on pathophysiology and immune defense mechanism of U937 by fibrates during M. tuberculosis infection