Jeong-Je Cho

Extracts from Citrus unshiu promote immune-mediated inhibition of tumor growth in a murine renal cell carcinoma model.

AIM OF THIS STUDY Citrus unshiu (Satsuma mandarin, SM) is a citrus fruit the peel of which has been used as a traditional Chinese medicine to treat common cold, relieve exhaustion, and cancer. In this study, we examined how effectively the content and peel extracts of SM can suppress cancer growth. The mechanism underlying cancer-suppressing properties of SM was investigated in tumor-bearing mice with renal carcinoma cell, Renca. MATERIALS AND METHODS Effectiveness of SM in tumor suppression was evaluated by measuring size of tumor mass in tumor-bearing mice treated with various doses of SM content and peel extracts. Proliferation of tumor cells and splenocytes was determined by MTT assay and [³H]TdR uptake, respectively. Relevant immunological mechanisms were chased by assaying cytokines including TGF-β, IL-6, IFN-γ, and TNF-α by ELISA. RESULTS The content and peel extracts of SM inhibited the growth of tumor cells in tumor-bearing mice. Especially, average tumor volume of two groups treated with 3 and 30 mg peel extracts per mouse weight (kg) were significantly decreased to 52.32% (p<0.05) and 68.72% (p<0.01), respectively. To identify tumor regression mechanism, anti-tumor cytokines measured in Con A-activated splenocytes from tumor-bearing mice. IFN-γ was increased in both of the peel extract-treated groups, while TNF-α, which had been decreased by tumor growth, was rescued to the normal level in SM content and peel extracts-treated groups. However, SM content and peel extracts did not inhibit proliferation and tumor-proliferative cytokines including TGF-β and IL-6 production of tumor cells. CONCLUSION These results indicate that SM content and peel extracts have anti-tumor properties in the tumor-bearing murine model. The mechanism underlying the anti-tumor effects of SM extracts is strongly suggested to be via boosting cytokines such as IFN-γ and TNF-α, enhancing immune-mediated anti-tumor properties.

The inhibitory effect of naringenin on atopic dermatitis induced by DNFB in NC/Nga mice

AIMS Atopic dermatitis (AD) is a chronic and relapsing inflammatory dermatitis characterized by pruritic and eczematous skin lesions. Here, we investigated the therapeutic effect of the fruit flavonoid naringenin on DNFB induced atopic dermatitis mice model. MAIN METHODS AD-like skin lesion was induced by repetitive skin contact with DNFB in NC/Nga mice and the effects of the fruit flavonoid naringenin were evaluated on the basis of histopathological findings of skin, ear swelling and cytokine production of CD4(+)T cells. KEY FINDINGS Intraperitoneal injection of naringenin for one week after DNFB challenge significantly lowered ear swelling and improved back skin lesions. In addition, naringenin significantly suppressed production of interferon-gamma (IFN-γ) by activated CD4(+) T cells and serum IgE level. Furthermore, naringenin reduced DNFB-induced infiltration of eosinophils, mast cells, CD4(+) T cells, and CD8(+) T cells in skin lesions. SIGNIFICANCE Naringenin may suppress the development of AD-like skin lesions in DNFB-treated NC/Nga mice by reducing IFN-γ production of activated CD4(+) T cells, serum IgE levels and infiltration of immune cells to skin lesion.

The histone deacetylase inhibitor, trichostatin A, inhibits the development of 2,4-dinitrofluorobenzene-induced dermatitis in NC/Nga mice.

Repetitive skin contact with a chemical hapten like 2,4-dinitrofluorobenzene (DNFB) evokes an atopic dermatitis (AD)-like dermatitis reaction in NC/Nga mice maintained under specific pathogen-free (SPF) conditions. The histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), modulates the expression of several genes by inhibiting the activity of HDACs. Furthermore, TSA has been reported to suppress inflammatory cytokine expression and to induce T cell-suppression by increasing regulatory T cell (T reg cell) numbers. In addition, histone deacetylase inhibitors (HDACi) are currently undergoing clinical trials for the treatment of inflammatory disorders. In the present study, we examined whether treatment with TSA suppresses AD-like skin lesions in NC/Nga mice treated with DNFB under SPF conditions. Intraperitoneal (i.p.) administration of TSA to DNFB-treated NC/Nga mice was found to inhibit ear thickness increases and the skin lesions induced by DNFB. Furthermore, IL-4 production by CD4+ T cells from the lymph nodes of DNFB-treated NC/Nga mice was significantly inhibited by TSA, although levels of IFN-γ were not. Flow cytometric analysis of lymphocytes showed an increase in CD4+ CD25+ T cell proportions in mice given TSA-i.p. These findings suggest that TSA suppresses the development of AD-like dermatitis in DNFB-treated NC/Nga mice by reducing IL-4 production and increasing the T reg cell population.

Profiling of gene expression using microarray in acrolein-treated human pulmonary fibroblasts

Pulmonary fibroblasts are essential for the integrity of alveolar structures and to restore lung tissue after injury. They are also important for inflammatory responses through their ability to attract leukocytes. Cigarette smoke has many harmful components, and causes various pulmonary and lung diseases including chronic obstructive pulmonary disease (COPD), chronic bronchitis, and emphysema. Acrolein (ACR), one of the compounds in cigarette smoke, induces inflammatory cytokines and the generation of DNA adducts, resulting in dysfunction of respiratory cells such as pulmonary fibroblasts. In this study, we examined the expression of genes in ACR-treated human pulmonary fibroblasts by microarray profiling. We identified 2,378 and 312 genes that were differentially expressed within 6 h of treatment with 10 μM or 25 μM ACR, respectively. These genes were classified as being involved in many biological processes including apoptosis, immune responses, cell cycle, and signal transduction. Some genes, including HSPA1B, HMOX1, CASP3, PRDX3, and ANXA1, are related to COPD. These results support the hypothesis that ACR may increase cytotoxicity and tissue injury in respiratory cells and may attribute to the development of pulmonary disease.

Integrated miRNA and mRNA expression profiling in response to eriodictyol in human endothelial cells

Eriodictyol, a flavonoid commonly found in citrus fruits, shows neurotrophic, antioxidant, anti- inflammatory, and anti-cancer effects under diverse pathophysiological conditions such as vascular diseases. In this study, we evaluated whether eriodictyol modulates miRNA and mRNA expression. Using microarray analysis, we examined miRNA and mRNA expression in human endothelial cells treated with 10 μM of eriodictyol for 24 h. Using numerous bioinformatic systems, we evaluated the signatures of the potential biological processes and signaling pathways. Our results provide insight into the underlying molecular mechanisms of action of eriodictyol and suggest that eriodictyol can be used for therapeutic intervention in vascular disease.

Immune Response Against 2,4-Dinitrofluorobenzene-Induced Atopic Dermatitis-Like Clinical Manifestation is Suppressed by Spermidine in NC⁄Nga Mice

Of the biogenic polyamines, spermidine is a natural constituent of living cells and organisms. Spermidine is associated with regulation of cell growth, proliferation and differentiation, and with the suppression of oxidation and inflammation. Atopic dermatitis (AD) is a chronic inflammatory skin disease that has a complex and multiple pathogenesis, which includes genetic abnormality, modified or abnormal immune response and the production of nitric oxide and reactive oxygen species. We investigated whether spermidine can relieve AD‐like clinical manifestation induced by the continual application of 2,4‐dinitrofluorobenzene (DNFB) in NC⁄Nga mice. Spermidine at concentrations of 1 or 10 mg/kg reduced increasing ear swelling and attenuated oedema, haemorrhage and hyperkeratosis in AD‐like skin lesions. Repetitive application of DNFB induced inflammatory cell infiltration to skin lesions, whereas intraperitoneal injection of spermidine inhibited DNFB‐evoked infiltration of eosinophils, mast cells and T lymphocytes. Furthermore, spermidine suppressed mast cell degranulation and production of interferon‐gamma by activated CD4+ T cells in AD‐like skin lesions. Spermidine may be a potential therapeutic agent for treatment of AD.

Aspartame Attenuates 2, 4-Dinitrofluorobenzene-Induced Atopic Dermatitis–Like Clinical Symptoms in NC/Nga Mice

Atopic dermatitis (AD) is a common multifactorial chronic skin disease that has a multiple and complex pathogenesis. AD is gradually increasing in prevalence globally. In NC/Nga mice, repetitive applications of 2, 4-dinitrofluorobenzene (DNFB) evoke AD-like clinical symptoms similar to human AD. Aspartame (N-L-α-aspartyl-L-phenylalanine 1-methyl ester) is a methyl ester of a dipeptide, which is used as an artificial non-nutritive sweetener. Aspartame has analgesic and anti-inflammatory functions that are similar to the function of nonsteroidal anti-inflammatory drugs such as aspirin. We investigated whether aspartame can relieve AD-like clinical symptoms induced by DNFB treatment in NC/Nga mice. Sucrose did not relieve AD-like symptoms, whereas aspartame at doses of 0.5 μg kg(-1) and 0.5 mg kg(-1) inhibited ear swelling and relieved AD-like clinical symptoms. Aspartame inhibited infiltration of inflammatory cells including eosinophils, mast cells, and CD4(+) T cells, and suppressed the expression of cytokines including IL-4 and IFN-γ, and total serum IgE levels. Aspartame may have therapeutic value in the treatment of AD.

Effect of crotonaldehyde on the induction of COX-2 expression in human endothelial cells

Cyclooxygenase-2 (COX-2), an inducible isoform protein, regulates diverse biological actions in vascular pathophysiology. COX-2 is induced in response to numerous stimuli, which results in prostaglandin (PG) production related to inflammation. Crotonaldehyde (CRA) is an extremely toxic α, β-unsaturated aldehyde and a major compound found in cigarette smoke. α, β-Unsaturated aldehyde in cigarette smoke is thought to mediate inflammation and vascular dysfunction. In this study, we evaluated the effect of CRA stimulation on COX-2 expression in human umbilical vein endothelial cells. CRA-stimulated COX-2 induction was accompanied by enhanced p38 phosphorylation and PGE2 generation. However, CRA-induced PGE2 production was reduced by pretreatment with an inhibitor of p38 MAPK. These results demonstrated that in human endothelial cells, CRA-induced COX-2-dependent PGE2 generation was mediated by p38 MAPK, and CRA may play a role in the development of inflammation.

Effect of crotonaldehyde on the induction of HO-1 expression in A549 cells

Cigarette smoke contains approximately 5,000 chemical components, including reactive chemicals and free radicals that are associated with an increased risk of chronic obstructive pulmonary disease (COPD). Cigarette smoke is also known to promote inflammation as part of various inflammatory airway diseases. Crotonaldehyde (CRA) is a highly toxic α, β-unsaturated aldehyde that is a major component of cigarette smoke. Exposure to CRA has been previously shown to result in adverse effects on respiratory health. Heme oxygenase-1 (HO-1) is an inducible enzyme that is activated by various stress-inducing stimuli to perform a diverse range of physiological functions, including anti-oxidant, anti-apoptotic, and anti-inflammatory effects. The present study aimed to investigate the effect of CRA stimulation on HO-1 expression in human lung adenocarcinoma epithelial (A549) cells. Stimulation of cells with CRA was shown to result in upregulated HO-1 expression via the induction of nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, and activation of the p38 mitogen-activated protein kinase (MAPK) pathway. Furthermore, zinc protoporphyrin (ZnPP; a specific HO-1 inhibitor) was used to inhibit HO-1 activity, and this was shown to cause a significant increase in the rate of apoptosis of CRA-exposed cells. Taken together, these results suggest that HO-1 exerts an anti-apoptotic effect in CRA-exposed human lung adenocarcinoma epithelial cells, and thus protects cells against CRA-induced oxidative stress.

Profiling of miRNA expression in mice kidney with diabetic nephropathy

BackgroundsDiabetic nephropathy (DN) is one of the complications of diabetes mellitus (DM) and the worldwide prevalence of DN has continued to increase. DN causes cellular stress and inflammation, which induces death of renal cells and dysfunction of blood vessels. MicroRNAs (miRNAs) are small interfering RNAs that negatively regulate mRNA gene expression. Various human diseases are attributed to aberrant miRNAs expression, and miRNAs levels are used as markers for diagnosis and classification of diseases. However, the profile of miRNAs in DN mouse have not been fully explained, we analyzed miRNAs expression in the kidney of diabetic mice.MethodsC57BL6 male mice were injected with streptozotocin (50 mg/kg body weight) for five consecutive days to induce DM. Mice were sacrificed after 16 weeks and RNAs were extracted from the kidneys and analyzed via microarray profiling.ResultsOur results confirmed that 137 miRNAs expression was altered in DM. These miRNAs showed pairwise correlations with 48 mRNAs in DM kidney. Furthermore, Differential expressed miRNAs were characterized by Gene Ontology (GO) enrichment analysis and signaling pathway using DAVID.ConclusionOur findings may provide that changes in miRNA expression in mice with diabetic nephropathy influences disease progression and might provide insights into the molecular mechanisms underlying DN.