• Nutrition Research and Practice
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• v.17 no.1
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• pp.164-173
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• 2023

BACKGROUND/OBJECTIVES: Hyperglycemia is a major cause of diabetes and diabetesrelated diseases. Sodium butyrate (NaB) is a short-chain fatty acid derivative that produces dietary fiber by anaerobic bacterial fermentation in the large intestine and occurs in foods, such as Parmesan cheese and butter. Butyrate has been shown to prevent obesity, improve insulin sensitivity, and ameliorate dyslipidemia in diet-induced obese mice. Therefore, this study examined the effects and mechanism of NaB on the secretion of inflammatory cytokines induced by high glucose (HG) in THP-1 cells. MATERIALS/METHODS: THP-1 cells were used as an in vitro model for HG-induced inflammation. The cells were cultured under normal glycemic or hyperglycemic conditions with or without NaB (0-25 μM). Western blotting and quantitative polymerase chain reaction were used to evaluate the protein and mRNA levels of nuclear factor-κB (NF-κB), interleukin-6, tumor necrosis factor-α, acetylated p65, acetyl CREB-binding protein/p300 (CBP/p300), and p300 using THP-1 cells. Histone acetyltransferase (HAT), histone deacetylase (HDAC), and pro-inflammatory cytokine secretion activity were analyzed using an enzyme-linked immunosorbent assay. RESULTS: HG significantly upregulated histone acetylation, acetylation levels of p300, NF-κB activation, and inflammatory cytokine release in THP-1 cells. Conversely, the NaB treatment reduced cytokine release and NF-κB activation in HG-treated cells. It also significantly reduced p65 acetylation, CBP/p300 HAT activity, and CBP/p300 gene expression. In addition, NaB decreased the interaction of p300 in acetylated NF-κB and TNF-α. CONCLUSIONS: These results suggest that NaB suppresses HG-induced inflammatory cytokine production through HAT/HDAC regulation in monocytes. NaB has the potential for preventing and treating diabetes and its related complications.

• Molecules and Cells
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• v.20 no.1
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• pp.97-104
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• 2005

To investigate apoptosis in HC11 mammary epithelial cells, we compared the gene expression profiles of actively growing and serum-starved apoptotic cells using a mouse apoptosis gene array and $^{33}P$-labeled cDNA prepared from the RNA of the two cultures. Analysis of the arrays showed that expression of several genes such as clusterin, secreted frizzled related protein mRNA (sFRP-1), CREB-binding protein (CBP), and others was higher in the apoptotic cells whereas expression of certain genes including survivin, cell division cycle 2 homolog A (CDC2), and cyclin A was lower. These expression patterns were confirmed by RT-PCR and/or Northern analyses. We compared the expression of some of these genes in the mouse mammary gland under various physiological conditions. The expression levels of genes (clusterin, CBP, and M6P-R) up-regulated in apoptotic conditions were higher at involution than during lactation. On the other hand, genes (Pin, CDC2) downregulated in apoptotic conditions were relatively highly expressed in virgin and pregnant mice. We conclude that certain genes such as clusterin, sFRP-1, GAS1 and CBP are induced in apoptotic mammary epithelial cells, and others are repressed. Moreover, the apoptosis array is an efficient technique for comparing gene expression profiles in different states of the same cell type.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.457-462
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• 2007

Histone acetyltransferase (HAT) is a family of enzymes that regulate histone acetylation. Dysfunction of HAT plays a critical role in the development of cancer. Here we have screened the various plant extracts to find out the potent HAT inhibitors. The bellflower (Platycodon grandiflorum) root have exhibited approximately 30% of the inhibitory effects on HAT activity, especially p300 and CBP (CREB-binding protein) at the concentration of $100\;{\mu}g/mL$. The cell viability was decreased approximately 52% in LNCaP cell for 48 hr incubation. Furthermore, mRNA level of 3 androgen receptor target genes, PSA, NKX3.1, and TSC22 were decreased with bellflower root extract treatment ($100\;{\mu}g/mL$) in the presence of androgen. In ChIP assay, the acetylation of histone H3 and H4 in PSA promoter region was dramatically repressed by bellflower root treatment, but not TR target gene, Dl. Therefore, the potent HAT inhibitory effect of bellflower root led to the decreased transcription of AR target genes and prostate cancer cell growth with the repression of histone hyperacetylation.

• Proceedings of the Korea Society of Poultry Science Conference
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• 1999.11a
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• pp.34-50
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• 1999

A cDNA encoding chicken interferon-gamma (chIFN-${\gamma}$) was amplified from P34, a CD4$^{+}$ T-cell hybridoma by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pUC18. THe sequences of cloned PCR products were determined to confirm the correct cloning. Using this cDNA as probe, chicken genomic library from White Leghorn spleen was screened. Phage clones harboring chicken interferon-gamma (chIFN-${\gamma}$) were isolated and their genomic structure elucidated. The chIFN-${\gamma}$ contains 4 exons and 3 introns spanning over 14 kb, and follows the GT/AG rule for correct splicing at the exon/intron boundaries. The four exons encode 41, 26, 57 and 40 amino acids, respectively, suggesting that the overall structure of IFN-${\gamma}$ is evolutionairly conserved in mammalian and avian species. The 5’-untranslated region and signal sequences are located in exon 1. Several AT-rich sequences located in the fourth exon may indicate a role in mRNA turnover. The 5’-flanking region contains sequences homologous to the potential binding sites for the mammalian transcription factors, activator protein-1(AP-1) activator protein-2(AP-2) cAMP-response element binding protein(CREB), activating transcription factor(ATF), GATA-binding fator(GATA), upstream stimulating factor(USF), This suggests that the mechanisms underlying transcriptional regulation of chicken and mammalian IFN-${\gamma}$ genes may be similar.r.

• BMB Reports
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• v.56 no.4
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• pp.252-257
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• 2023

The hypoxia-inducible factor-1α (HIF-1α) is a key regulator of hypoxic stress under physiological and pathological conditions. HIF-1α protein stability is tightly regulated by the ubiquitin-proteasome system (UPS) and autophagy in normoxia, hypoxia, and the tumor environment to mediate the hypoxic response. However, the mechanisms of how the UPS and autophagy interplay for HIF-1α proteostasis remain unclear. Here, we found a HIF-1α species propionylated at lysine (K) 709 by p300/CREB binding protein (CBP). HIF-1α stability and the choice of degradation pathway were affected by HIF-1α propionylation. K709-propionylation prevented HIF-1α from degradation through the UPS, while activated chaperon-mediated autophagy (CMA) induced the degradation of propionylated and nonpropionylated HIF-1α. CMA contributed to HIF-1α degradation in both normoxia and hypoxia. Furthermore, the pan-cancer analysis showed that CMA had a significant positive correlation with the hypoxic signatures, whereas SIRT1, responsible for K709-depropionylation correlated negatively with them. Altogether, our results revealed a novel mechanism of HIF-1α distribution into two different degradation pathways.

• Molecules and Cells
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• v.37 no.12
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• pp.899-906
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• 2014

Prostaglandin $E_2$ ($PGE_2$) promotes tumor-persistent inflammation, frequently resulting in cancer. Curcumin is a diphenolic turmeric that inhibits carcinogenesis and induces apoptosis. $PGE_2$ inhibits curcumin-induced apoptosis; however, the underlying inhibitory mechanisms in colon cancer cells remain unknown. The aim of the present study is to investigate the survival role of $PGE_2$ and whether addition of exogenous $PGE_2$ affects curcumininduced cell death. HCT-15 cells were treated with curcumin and $PGE_2$, and protein expression levels were investigated via Western blot. Reactive oxygen species (ROS) generation, lipid peroxidation, and intracellular glutathione (GSH) levels were confirmed using specific dyes. The nuclear factor-kappa B ($NF-{\kappa}B$) DNA-binding was measured by electrophoretic mobility shift assay (EMSA). $PGE_2$ inhibited curcumin-induced apoptosis by suppressing oxidative stress and degradation of PARP and lamin B. However, exposure of cells to the EP2 receptor antagonist, AH6809, and the PKA inhibitor, H89, before treatment with $PGE_2$ or curcumin abolished the protective effect of $PGE_2$ and enhanced curcumin-induced cell death. $PGE_2$ activates PKA, which is required for cAMP-mediated transcriptional activation of CREB. $PGE_2$ also activated the Ras/Raf/Erk pathway, and pretreatment with PD98059 abolished the protective effect of $PGE_2$. Furthermore, curcumin treatment greatly reduced phosphorylation of CREB, followed by a concomitant reduction of $NF-{\kappa}B$ (p50 and p65) subunit activation. $PGE_2$ markedly activated nuclear translocation of $NF-{\kappa}B$. EMSA confirmed the DNA-binding activities of $NF-{\kappa}B$ subunits. These results suggest that inhibition of curcumin-induced apoptosis by $PGE_2$ through activation of PKA, Ras, and $NF-{\kappa}B$ signaling pathways may provide a molecular basis for the reversal of curcumin-induced colon carcinoma cell death.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.148-157
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• 2019

A 70% ethanol extract of Erigeron annuus (L.) Pers. was investigated for its whitening activity for application as a functional ingredient in cosmetic products. At the E. annuus extract concentration of $100{\mu}g/ml$, the electron-donating ability was found to be 67.83%, the tyrosinase inhibitory effect (related to skin-whitening) was 69%, the elastase inhibitory effect (related to skin-wrinkling) was 69%, and the astringent effect was 80%. The $ABTS^+$ radical-scavenging ability was 87% at the $500{\mu}g/ml$ concentration. In the cell viability test measured on melanoma cells, 96% of the cells treated with $100{\mu}g/ml$ of the extract were viable. According to the western blot results, the protein expression of the microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 was decreased by 60.22%, 47.83%, 54.79%, and 67.88%, respectively, at the extract concentration of $100{\mu}g/ml$. The protein expression of phosphorylated extracellular signal regulated kinase (p-ERK) and phosphorylated cAMP response element-binding protein (p-CREB) was decreased with increasing concentrations of the extract. Reverse transcription-polymerase chain reaction of the extract showed that the mRNA expression of MITF, tyrosinase, TRP-1, and TRP-2 was decreased by 86.51%, 85.22%, 74.26%, and 66.66%, respectively, at $100{\mu}g/ml$ extract concentration. The findings suggest that the 70% ethanol extract from E. annuus (L.) Pers. has potential as a cosmeceutical ingredient with whitening effect.

• Korean Journal of Biological Psychiatry
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• v.11 no.1
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• pp.14-25
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• 2004

The current understanding of the mechanisms of pharmacotherapy for depression is characterized by an emphasis on increasing synaptic availability of serotonin, noradrenaline, and possibly dopamine, while minimizing side effects. The acute effects of current available effective antidepressants include blocking selective serotonin or noradrenaline reuptake, alpha2 autoreceptors or monoamine oxidase. Although efficacious, current treatments often produce partial or limited symptomatic improvement rather than remission. While current pharmacotherapies target monoaminergic systems, distinct neurobiological underpinnings and other systems are likely involved in the pathogenesis of depression. Recently, several promising hypotheses of depression and antidepressant action have been formulated. These hypotheses are largely based on dsyregulation of neural plasticity, CREB, BDNF, corticotropin-releasing factor, glucocorticoid, hypothalamic-pituitary adrenal axis and cytokines. Based on these new theories and hypotheses of depression, a number of new and novel agents, including corticotropin-releasing factor antagonists, antiglucocorticoids, and substance P antagonists show a considerable promise for refining treatment options for depression. In this article, the current available pharmacotherapies, current understanding of neurobiology and pathogenesis of depression and new and promising directions in pharmacological research on depression will be discussed.

• BMB Reports
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• v.37 no.2
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• pp.177-184
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• 2004

The Crustacean hyperglycemic hormone (CHH) has been shown to exist as multiple molecular forms in several crustacean species. In Penaeus monodon, a gene encoding CHH (so-called Pem-CHH1) was recently described. In this study, the molecular structures of two other CHH genes (Pem-CHH2 and Pem-CHH3) are reported. Both the Pem-CHH2 and Pem-CHH3 genes contain three exons that are separated by two introns that are similar to the structure of other genes in the same family. An analysis of the upstream nucleotide sequences of each Pem-CHH gene has identified the putative promoter element (TATA box) and putative binding sites for several transcription factors. The binding sites for CREB, Pit-1, and AP-1 were found upstream of all three Pem-CHH genes. A Southern blot analysis showed that at least one copy of each Pem-CHH gene was located within the same 10 kb genomic DNA fragment. These results suggest that the CHH genes are arranged in a cluster in the genome of P. monodon, and that their expression may be modulated by similar mechanisms.

• Molecules and Cells
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• v.44 no.7
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• pp.493-499
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• 2021

Parkinson's disease (PD) is characterized by a progressive loss of dopamine-producing neurons in the midbrain, which results in decreased dopamine levels accompanied by movement symptoms. Oral administration of l-3,4-dihydroxyphenylalanine (L-dopa), the precursor of dopamine, provides initial symptomatic relief, but abnormal involuntary movements develop later. A deeper understanding of the regulatory mechanisms underlying dopamine homeostasis is thus critically needed for the development of a successful treatment. Here, we show that p21-activated kinase 4 (PAK4) controls dopamine levels. Constitutively active PAK4 (caPAK4) stimulated transcription of tyrosine hydroxylase (TH) via the cAMP response element-binding protein (CREB) transcription factor. Moreover, caPAK4 increased the catalytic activity of TH through its phosphorylation of S⁴⁰, which is essential for TH activation. Consistent with this result, in human midbrain tissues, we observed a strong correlation between phosphorylated PAK4^S474, which represents PAK4 activity, and phosphorylated TH^S40, which reflects their enzymatic activity. Our findings suggest that targeting the PAK4 signaling pathways to restore dopamine levels may provide a new therapeutic approach in PD.