PURPOSE: Protein overloading in the endoplasmic reticulum (ER) leads to endoplasmic reticulum stress, which exacerbates various disease conditions. Emodin, an anthraquinone compound, is known to have several health benefits. The effect of emodin against palmitic acid (PA) - induced ER stress in HepG2 cells was investigated. METHODS: HepG2 cells were treated with varying concentrations of palmitic acid to determine the working concentration that induced ER stress. ER stress associated genes such as ATF4, XBP1s, CHOP and GRP78 were checked using RT- PCR. In addition, the expression levels of unfolded protein response (UPR) associated proteins such as IRE1α, eIF2α and CHOP were checked using immunoblotting to confirm the induction of ER stress. The effect of emodin on ER stress was analyzed by treating HepG2 cells with 750 µM palmitic acid and varying concentrations of emodin, then analyzing the expression of UPR associated genes. RESULTS: It was evident from the mRNA and protein expression results that palmitic acid significantly increased the expression of UPR associated genes and thereby induced ER stress. Subsequent treatment with emodin reduced the mRNA expression of ATF4, GRP78, and XBP1s. Furthermore, the protein levels of p-IRE1α, p-elF2α and CHOP were also reduced by the treatment of emodin. Analysis of sirtuin mRNA expression showed that emodin increased the levels of SIRT4 and SIRT7, indicating a possible role in decreasing the expression of UPR-related genes. CONCLUSION: Altogether, the results suggest that emodin could exert a protective effect against fatty acid-induced ER stress and could be an agent for the management of various ER stress related diseases.
Emodin ; Endoplasmic Reticulum Stress ; Endoplasmic Reticulum ; Hep G2 Cells ; Immunoblotting ; Insurance Benefits ; Palmitic Acid ; Polymerase Chain Reaction ; RNA, Messenger ; Sirtuins ; Unfolded Protein Response

PURPOSE: Although the interferon α (IFNα) signaling and the paired-like homeodomain transcription factor 2 (PITX2) have both been implicated in the progression of breast cancer (BCa), it remains obscure whether these two pathways act in a coordinated manner. We therefore aimed to elucidate the expression and function of PITX2 during the pathogenesis of endocrine resistance in BCa. MATERIALS AND METHODS: PITX2 expression was assessed in BCa tissues using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunohistochemistry and in experimentally induced letrozole-resistant BCa cells using RT-qPCR and immunoblotting. Effects of PITX2 deregulation on BCa progression was determined by assessing MTT, apoptosis and xenograft model. Finally, using multiple assays, the transcriptional regulation of interferon-inducible transmembrane protein 1 (IFITM1) by PITX2 was studied at both molecular and functional levels. RESULTS: PITX2 expression was induced in letrozole-resistant BCa tissues and cells, and PITX2 induction by IFNα signaling powerfully protected BCa cells against letrozole insult and potentiated letrozole-resistance. Mechanistically, PITX2 enhanced IFNα-induced AKT activation by transactivating the transcription of IFITM1, thus rendering BCa cells unresponsive to letrozoleelicited cell death. Additionally, ablation of IFITM1 expression using siRNA substantially abolished IFNα-elicited AKT phosphorylation, even in the presence of PITX2 overexpression, thus sensitizing BCa cells to letrozole treatment. CONCLUSION: These results demonstrate that constitutive upregulation of PITX2/IFITM1 cascade is an intrinsic adaptive mechanism during the pathogenesis of letrozole-resistance, and modulation of PITX2/IFITM1 level using different genetic and pharmacological means would thus have a novel therapeutic potential against letrozole resistance in BCa.
Apoptosis ; Breast Neoplasms ; Breast ; Cell Death ; Heterografts ; Immunoblotting ; Immunohistochemistry ; Interferons ; Phosphorylation ; Polymerase Chain Reaction ; Reverse Transcription ; RNA, Small Interfering ; Transcription Factors ; Transcriptional Activation ; Up-Regulation

Xylitol is well-known to have an anti-caries effect by inhibiting the replication of cariogenic bacteria. In addition, xylitol enhances saliva secretion. However, the precise molecular mechanism of xylitol on saliva secretion is yet to be elucidated. Thus, in this study, we aimed to investigate the stimulatory effect of xylitol on saliva secretion and to further evaluate the involvement of xylitol in muscarinic type 3 receptor (M3R) signaling. For determining these effects, we measured the saliva flow rate following xylitol treatment in healthy individuals and patients with dry mouth. We further tested the effects of xylitol on M3R signaling in human salivary gland (HSG) cells using real-time quantitative reverse-transcriptase polymerase chain reaction, immunoblotting, and immunostaining. Xylitol candy significantly increased the salivary flow rate and intracellular calcium release in HSG cells via the M3R signaling pathway. In addition, the expressions of M3R and aquaporin 5 were induced by xylitol treatment. Lastly, we investigated the distribution of M3R and aquaporin 5 in HSG cells. Xylitol was found to activate M3R, thereby inducing increases in Ca²⁺ concentration. Stimulation of the muscarinic receptor induced by xylitol activated the internalization of M3R and subsequent trafficking of aquaporin 5. Taken together, these findings suggest a molecular mechanism for secretory effects of xylitol on salivary epithelial cells.
Aquaporin 5 ; Bacteria ; Calcium ; Calcium Signaling ; Candy ; Epithelial Cells ; Humans ; Immunoblotting ; Mouth ; Polymerase Chain Reaction ; Receptors, Muscarinic ; Saliva ; Salivary Glands ; Xylitol

BACKGROUND: Osteoporosis is a geriatric disease with diminished bone density. The increase in the number of patients and medical expenses due to a global aging society are recognized as problems. Bone loss is the most common symptom of bone disease, not only osteoporosis but Paget's disease, rheumatoid arthritis, multiple myeloma, and other diseases. The main cause of this symptoms is excessive increase in the number and activity of osteoclasts. Osteoclasts are multinucleated giant cells that can resorb bone. They are differentiated and activation from monocytes/macrophages in the presence of macrophage colony-stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL). METHODS: The effect of extract of Flavoparmelia sp. (EFV), a genus of lichenized fungi within the Parmeliaceae, on the differentiation of bone marrow-derived macrophages (BMMs) into osteoclasts was examined by phenotype assay and the cell cytotoxicity was evaluated by cell counting kit-8. The osteoclast differentiation-related genes and proteins were investigated by real-time polymerase chain reaction and immunoblotting. The functional activity of osteoclast in response to EFV treatment was evaluated by an Osteo Assay plate. RESULTS: In this study, we found that EFV, a genus of lichenized fungi within the Parmeliaceae, inhibited osteoclast formation. And we investigated its inhibitory mechanism. EFV reduced RANKL-mediated osteoclast formation and activation by inhibiting expression of nuclear factor of activated T cells 1, a key factor of osteoclastogenesis. CONCLUSIONS: Taken together, our results show that EFV is a promising candidate for health functional foods or therapeutic agents that can help treat bone diseases such as osteoporosis.
Aging ; Arthritis, Rheumatoid ; Bone Density ; Bone Diseases ; Cell Count ; Functional Food ; Fungi ; Giant Cells ; Humans ; Immunoblotting ; Lichens ; Macrophage Colony-Stimulating Factor ; Macrophages ; Multiple Myeloma ; NFATC Transcription Factors ; Osteoclasts ; Osteoporosis ; Parmeliaceae ; Phenotype ; Real-Time Polymerase Chain Reaction ; T-Lymphocytes

PURPOSE: Little is known about the importance of lipid transfer protein (LTP) sensitization in China. In this study, we investigated the relationship between LTP sensitization and the severity of clinical symptoms in a population of patients with mugwort pollen-related food allergy. METHODS: Food-induced symptoms were evaluated in 148 patients with mugwort pollen allergy by a standardized questionnaire. Specific immunoglobulin E (IgE) to Art v 1, Art v 3, Pru p 3, Ara h 9 and Cor a 8 were quantified by ImmunoCAP. Immunoblotting of peach extracts were performed with sera from peach-allergic patients. RESULTS: In total, 72% (107/148) of the study population experienced food allergy. Forty-eight percent (51/107) of patients with mugwort pollen-related food allergy experienced at least 1 episode of food-induced anaphylaxis. Food allergy correlated with IgE reactivity to Art v 3, but not to Art v 1. Sensitization to Pru p 3, Ara h 9 or Cor a 8 was prevalent (80%, 69 or 63%, respectively) among individuals with food allergy. Food allergic patients with systemic reactions (SR) had higher values for Pru p 3, Ara h 9 and Cor a 8 than patients with oral allergy syndrome (OAS). Furthermore, the strong IgE reactivity detected in immunoblots of peach extracts indicated that Pru p 3 was the major allergen and was more prevalent in patients with SR than in patients with OAS (100% vs. 55%). CONCLUSIONS: LTPs are major food allergens for mugwort pollen-related food allergy in China, and may contribute to SR.
Allergens ; Anaphylaxis ; Artemisia* ; Asian Continental Ancestry Group* ; China ; Food Hypersensitivity* ; Humans ; Hypersensitivity* ; Immunoblotting ; Immunoglobulin E ; Immunoglobulins ; Prunus persica ; Rhinitis, Allergic, Seasonal

BACKGROUND: The pain-relief properties of tricyclic antidepressants can be attributed to several actions. Recent observations suggest that adenosine is involved in the antinociceptive effect of amitriptyline. The A3 adenosine receptor (A3AR) is the only adenosine subtype overexpressed in inflammatory and cancer cells. This study was performed to investigate the role of A3AR in the anti-nociceptive effect of amitriptyline. METHODS: Spinal nerve-ligated neuropathic pain was induced by ligating the L5 and L6 spinal nerves of male Sprague-Dawley rats. The neuropathic rats were randomly assigned to one of the following three groups (8 per group): a neuropathic pain with normal saline group, a neuropathic pain with amitriptyline group, and a neuropathic pain with amitriptyline and 3-ethyl-5-benzyl- 2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS) group. Amitriptyline or saline was administered intraperitoneally and 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS-1191), an A3AR antagonist, was injected subcutaneously immediately before amitriptyline administration. The level of extracellular signal-regulated kinase P44/42 (ERK1/2), cyclic AMP response element-binding protein (CREB), and proinflammatory cytokines were assessed using immunoblotting or reverse-transciption polymerase chain reaction. RESULTS: Amitriptyline increased the mechanical withdrawal threshold of the neuropathic rats. The level of phospho-ERK1/2 and phospho-CREB proteins, and proinflammatory cytokines produced by spinal nerve ligation were significantly reduced by amitriptyline administration. However, the use of MRS-1191 before amitriptyline administration not only reduced the threshold of mechanical allodynia, but also increased the signaling protein and proinflammatory cytokine levels, which were reduced by amitriptyline. CONCLUSIONS: The results of this study suggest that the anti-nociceptive effect of amitriptyline involves the suppression of ERK1/2 and CREB signaling proteins, and A3AR activation also affects the alleviation of the inflammatory response.
Adenosine ; Amitriptyline ; Animals ; Antidepressive Agents, Tricyclic ; Cyclic AMP Response Element-Binding Protein ; Cytokines ; Humans ; Hyperalgesia ; Immunoblotting ; Ligation ; Male ; Neuralgia ; Phosphotransferases ; Polymerase Chain Reaction ; Rats ; Rats, Sprague-Dawley ; Receptors, Purinergic P1 ; Spinal Nerves

BACKGROUND: Oral cancer has a high incidence worldwide and has been closely associated with smoking, alcohol, and infection by the human papillomavirus. Metastasis is highly important for oral cancer survival. Lysophosphatidic acid (LPA) is a bioactive lipid mediator that promotes various cellular processes, including cell survival, proliferation, metastasis, and invasion. Signal transducer and activator of transcription (STATs) are transcription factors that mediate gene expression. Among the seven types of STATs in mammals, STAT3 is involved in invasion and metastasis of numerous tumors. However, little is known about the role of STAT3 in oral tumor invasion. In the present study, we hypothesized that STAT3 mediates LPA-induced oral cancer invasion. METHODS: Immunoblotting was performed to analyze LPA-induced STAT3 activation. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was performed to assess the survival rates of YD-10B cells. STAT3 levels in LPA-treated oral tumor cells were evaluated by performing in vitro invasion assay. RESULTS: To the best of our knowledge, this is the first study to demonstrate that LPA enhances STAT3 phosphorylation in oral cancer. In addition, treatment with WP1066, a selective inhibitor of STAT3, at a concentration that does not cause severe reduction in cell viability, significantly attenuated LPA-induced YD-10B cancer cell invasion. CONCLUSION: The results suggested that LPA induces oral tumor cells with greater invasive potential via STAT3 activation. Our findings provided important insights into the mechanisms underlying mouth neoplasms.
Cell Survival ; Epithelial-Mesenchymal Transition ; Gene Expression ; Humans ; Immunoblotting ; In Vitro Techniques ; Incidence ; Lysophospholipids ; Mammals ; Mouth Neoplasms ; Neoplasm Metastasis ; Phosphorylation ; Smoke ; Smoking ; STAT3 Transcription Factor ; Survival Rate ; Transcription Factors ; Transducers

BACKGROUND/AIMS: Indoxyl sulfate (IS) is a uremic toxin and an important causative factor in the progression of chronic kidney disease. Recently, paricalcitol (19-nor-1,25-dihydroxyvitamin D2) was shown to exhibit protective effects in kidney injury. Here, we investigated the effects of paricalcitol treatment on IS-induced renal tubular injury. METHODS: The fluorescent dye 2ʹ,7ʹ-dichlorofluorescein diacetate was used to measure intracellular reactive oxygen species (ROS) following IS administration in human renal proximal tubular epithelial (HK-2) cells. The effects of IS on cell viability were determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and levels of apoptosis-related proteins (Bcl-2-associated protein X [Bax] and B-cell lymphoma 2 [Bcl-2]), nuclear factor-κB (NF-κB) p65, and phosphorylation of mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) were determined by semiquantitative immunoblotting. The promoter activity of NF-κB was measured by luciferase assays and apoptosis was determined by f low cytometry of cells stained with f luorescein isothiocyanate-conjugated Annexin V protein. RESULTS: IS treatment increased ROS production, decreased cell viability and induced apoptosis in HK-2 cells. IS treatment increased the expression of apoptosis-related protein Bax, decreased Bcl-2 expression, and activated phosphorylation of MAPK, NF-κB p65, and Akt. In contrast, paricalcitol treatment decreased Bax expression, increased Bcl-2 expression, and inhibited phosphorylation of MAPK, NF-κB p65, and Akt in HK-2 cells. NF-κB promoter activity was increased following IS, administration and was counteracted by pretreatment with paricalcitol. Additionally, flow cytometry analysis revealed that IS-induced apoptosis was attenuated by paricalcitol treatment, which resulted in decreased numbers of fluorescein isothiocyanate-conjugated Annexin V positive cells. CONCLUSIONS: Treatment with paricalcitol inhibited IS-induced apoptosis by regulating MAPK, NF-κB, and Akt signaling pathway in HK-2 cells.
Annexin A5 ; Apoptosis* ; Cell Survival ; Flow Cytometry ; Fluorescein ; Humans ; Immunoblotting ; Indican ; Kidney ; Luciferases ; Lymphoma, B-Cell ; Phosphorylation ; Protein Kinases ; Proto-Oncogene Proteins c-akt ; Reactive Oxygen Species ; Renal Insufficiency, Chronic ; Signal Transduction

BACKGROUND: Fluoranthene (FR) is a common environmental pollutant that exists in a complex mixture with other polycyclic aromatic hydrocarbons (PAHs). We identified biomarkers for monitoring FR exposure and investigated the rescue effect of FR-induced cellular toxicity via aryl hydrocarbon receptor (AHR) antagonist activity in bone marrow derived mesenchymal stem cells (BM-MSCs).METHODS: Morphological changes, viability, and rescue effects of an AHR antagonist (CH223191) were examined in BM-MSCs after exposure to FR. Cytotoxic effects were assayed using the tetrazolium-based colorimetric assay. Apoptosis was measured by annexin V and propidium iodide dye-based flowcytometry assay, mitochondrial membrane potential assay, and nuclear DNA fragmentation assay. Molecular signaling pathways of apoptosis and autophagy were investigated using immunoblotting. Proteomics were performed in order to reveal the spectra of cellular damage and identify biomarkers for FR exposure.RESULTS: Exposing BM-MSCs to FR (IC₅₀=50 µM) induced cell death and morphological changes, while the AHR antagonist showed rescue effects. Autophagy was activated and mitochondrial membrane potential was decreased. Proteomic analysis identified 48 deregulated proteins (26 upregulated and 22 downregulated). Among them, annexin A6, pyruvate kinase, UDP-glucose dehydrogenase, and phospholipase A2 could be potential biomarkers for FR exposure.CONCLUSION: The exposure of BM-MSCs to FR induced remarkable alterations in cellular biology and the proteome, allowing for identification of novel biomarkers for FR exposure. Furthermore, AHR antagonists might be able to prevent cellular damage due to FR exposure.
Annexin A5 ; Annexin A6 ; Apoptosis ; Autophagy ; Biomarkers ; Bone Marrow ; Cell Death ; DNA Fragmentation ; Immunoblotting ; Membrane Potential, Mitochondrial ; Mesenchymal Stromal Cells ; Oxidoreductases ; Phospholipases A2 ; Polycyclic Hydrocarbons, Aromatic ; Propidium ; Proteome ; Proteomics ; Pyruvate Kinase ; Receptors, Aryl Hydrocarbon

Tight junctions (TJs) are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules (JAMs), and zonula occludens (ZO). Tight junction proteins can sense the presence of bacteria and regulate the transcription of target genes that encode effectors and regulators of the immune response. The aim of this study was to determine the impact of TJ proteins in response to Porphyromonas gingivalis (P. gingivalis), P. gingivalis lipopolysaccharide (P. gingivalis LPS), and extracellular adenosine triphosphate (ATP) in the oral epithelial cell culture model. Quantified real time-polymerase chain reaction (RT-PCR), immunoblots, and immunostaining were performed to assess the gene and protein expression in TJs. It was found that P. gingivalis infection led to transient upregulation of the genes encoding occludin, claudin-1, and claudin-4 but not JAM-A, claudin-15, or ZO-1, while P. gingivalis LPS increased claudin-1, claudin-15, and ZO-1 and decreased occludin, JAM-A, and claudin-4. Tight junction proteins showed significant upregulation in the above two groups when cells were pretreated with ATP for 3 h. The findings indicated that P. gingivalis induced the host defence responses at an early stage. P. gingivalis LPS exerted a more powerful stimulatory effect on the disruption of the epithelial barrier than P. gingivalis. ATP stimulation enhanced the reaction of TJ proteins to P. gingivalis invasion and LPS destruction of the epithelium.International Journal of Oral Science (2018) 10, e8; doi:10.1038/ijos.2017.51; published online 10 January 2018.
Adenosine Triphosphate ; pharmacology ; Cells, Cultured ; Epithelial Cells ; cytology ; Gene Expression ; Humans ; Immunoblotting ; Lipopolysaccharides ; pharmacology ; Mouth Mucosa ; cytology ; Porphyromonas gingivalis ; immunology ; Real-Time Polymerase Chain Reaction ; Tight Junction Proteins ; metabolism ; Up-Regulation