Upregulation of HO-1 is accompanied by activation of p38MAPK and mTOR in human oesophageal squamous carcinoma cells

Macroporous resin purification of phenolics from Irish apple pomace: Chemical characterization, and cellular antioxidant and anti-inflammatory activities

Apple pomace (AP) is a highly prevalent waste product worldwide in the fruit processing sector. This study compared the chemical profile, antioxidant, and anti-inflammatory activities of crude (CE) and an extract purified using XAD-7 resin (PE). The purification process increased the total phenolic content, flavonoids, and tannins by 3.35, 40.31, and 8.87-fold, respectively. The main phenolic compounds identified in PE were phlorizin (20.54 mg/g), chlorogenic acid (10.01 mg/g), and hyperoside (2.77 mg/g). No difference was found between CE and PE in protecting human plasma against oxidation. In human erythrocytes, both CE and PE decreased the reactive oxygen species (ROS) generation and decreased lipoperoxidation. However, PE had stronger anti-inflammatory effects than CE by promoting HO-1 gene expression, suppressing NO production, and inhibiting IL-1β, IL-6, and IL-10 mRNA expression in lipopolysaccharide-challenged RAW.264.7 macrophages. Therefore, purifying apple pomace crude extract is a promising approach to boosting valuable antioxidants and anti-inflammatory phenolics.

Carbon monoxide (CO)/heme oxygenase (HO)-1 in gastrointestinal tumors pathophysiology and pharmacology - possible anti- and pro-cancer activities

Gastrointestinal (GI) tract cancers pose a significant pharmacological challenge for researchers in terms of the discovery of molecular agents and the development of targeted therapies. Although many ongoing clinical trials have brought new perspectives, there is still a lack of successful long-term treatment. Several novel pharmacological and molecular agents are being studied in the prevention and treatment of GI cancers. On the other hand, pharmacological tools designed to release an endogenous gaseous mediator, carbon monoxide (CO), were shown to prevent the gastric mucosa against various types of injuries and exert therapeutic properties in the treatment of GI pathologies. In this review, we summarized the current evidence on the role of CO and heme oxygenase 1 (HO-1) as a CO producing enzyme in the pathophysiology of GI tumors. We focused on a beneficial role of HO-1 and CO in biological systems and common pathological conditions. We further discussed the complex and ambiguous function of the HO-1/CO pathway in cancer cells with a special emphasis on molecular and cellular pro-cancerous and anti-cancer mechanisms. We also focused on the role that HO-1/CO plays in GI cancers, especially within upper parts such as esophagus or stomach.

Ginger extract ameliorates bisphenol A (BPA)-induced disruption in thyroid hormones synthesis and metabolism: Involvement of Nrf-2/HO-1 pathway

Environmental exposure to BPA is alarming because of the potential health threats for example those concerning the thyroid glands which may show signs of oxidative stress. This original study aimed to investigate the possible antioxidant protective effects of ginger extract (GE) against BPA-induced thyroid injury in male rats, focusing on its effect on Nrf-2/HO-1 signaling and thyroid hormone synthesis regulating genes. The cascade of events in thyroid injury induced by chronic exposure to BPA (200 mg/kg b.w/day for 35 days) involved a preliminary overproduction of ROS followed by significant (p ≤ 0.05) depletion of reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity as well as significant increases of malondialdehyde (MDA) contents, myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS) gene expression. These actions consequently down-regulate the Nrf-2/HO-I signaling which eventually resulting in the DNA fragmentation within the thyroid tissues. Moreover, BPA administration caused a reduction of thyroid iodide uptake evidenced by significant inhibitions (p ≤ 0.05) of sodium-iodide symporter (NIS), thyroid peroxidase (TPO) and thyroid-stimulating hormone receptor (TSHR) mRNA expressions within the thyroid glands. A subsequent significant decreased serum levels of T3 and T4 accompanied by a significantly increased serum TSH level were also detected. These findings were confirmed by the severe pathological changes detected in the thyroid tissue of BPA treated rats. These biochemical and histological alterations were significantly alleviated with ginger administration (250 mg/kg b.w/day for 35 days) plus BPA. In conclusion, ginger extract is a potent antioxidant that can effectively protect against BPA-induced thyroid oxidative damage by activating the Nrf-2/HO-1 gene expressions and enhancing the thyroid hormones synthesis. This is the first study to show the contribution of Nrf-2/HO-1 pathway to the protective effect of ginger extract against BPA-induced thyroid oxidative damage and thyroid hormonal disruption.

Identification of potential key genes in esophageal adenocarcinoma using bioinformatics

Esophageal adenocarcinoma (EAC) is the predominant pathological subtype of esophageal cancer in Europe and the USA. The present bioinformatics study analyzed a high-throughput sequencing dataset, GSE94869, to determine differentially expressed genes (DEGs) in order to identify key genes, biological processes and pathways associated with EAC. Functional enrichment analysis was performed using the Database for Annotation Visualization and Integrated Discovery. The co-expression network of the DEGs was established using Weighted Gene Co-Expression Network Analysis and visualized using Cytoscape. A Kaplan-Meier analysis based on The Cancer Genome Atlas (TCGA) database was used to identify prognosis-associated genes. Univariate and multivariate Cox proportional hazard models were used to identify genes with a prognostic value regarding relapse-free survival (RFS), while validation of the differential expression of prognosis-associated genes was performed using a box plot based on data from TCGA and another microarray dataset, GSE26886. A total of 130 DEGs, comprising 82 upregulated and 48 downregulated genes, were identified. The upregulated DEGs were significantly associated with extracellular matrix organization, disassembly, and the phosphoinositide-3 kinase/AKT, Rap1 and Ras signaling pathways, while the downregulated genes were associated with the Wnt signalling pathway. Subsequently, two co-expression modules were established and 20 hub genes were identified. The blue module was associated with the Rap1 signaling pathway, while the turquoise module was associated with the Ras and Rap1 signaling pathways. Among them, methyltransferase like 7B (METTL7B) was associated with RFS. Furthermore, the overexpression of METTL7B in EAC was successfully validated using data from TCGA and GSE26886. The present study identified key genes and provides potential biomarkers for the diagnosis and treatment of EAC.

Low heme oxygenase-1 expression promotes gastric cancer cell apoptosis, inhibits proliferation and invasion, and correlates with increased overall survival in gastric cancer patients

Heme oxygenase-1 (HO-1) plays a key role in anti-oxidation, anti-apoptosis, and anti-proliferation in various types of cancers. However, the relationship between HO-1 expression and gastric cancer development remains largely unknown. In this study, the protein expression of HO-1 in human gastric cancer was measured by immunohistochemistry on paraffin sections of 89 paired gastric carcinoma tissues and adjacent non-cancer tissues. The correlation of HO-1 expression with 5-year overall survival rate was estimated. The effects of decreased HO-1 expression by two strands of small interfered RNAs (siRNAs) on cell apoptosis, proliferation, and invasion of gastric cancer cell lines were examined by flow cytometry, the MTT assay, and the cell migration assay, respectively. High expression of HO-1 was detected in 11.2% (10/89) of gastric carcinoma tissues, compared with 1.1% (1/89) in matched adjacent normal tissues, and correlated with a decreased survival rate in gastric cancer patients. There were no significant correlations between HO-1 expression and clinical characteristics. Downregulation of HO-1 expression using two strands of siRNAs promoted apoptosis and inhibited the proliferation and invasion of two gastric cancer cell lines, SGC7901 and MKN-28 cells. This study demonstrated that HO-1 plays a vital role in the development of gastric cancer and may serve as a therapeutic target of this type of cancer.

Activation of P2X7 receptors decreases the proliferation of murine luteal cells

Extracellular ATP regulates cellular function in an autocrine or paracrine manner through activating purinergic signalling. Studies have shown that purinergic receptors were expressed in mammalian ovaries and they have been proposed as an intra-ovarian regulatory mechanism. P2X7 was expressed in porcine ovarian theca cells and murine and human ovarian surface epithelium and is involved in ATP-induced apoptotic cell death. However, the role of P2X7 in corpus luteum is still unclear. The aim of this study was to investigate the role of ATP signalling in murine luteal cells and the possible mechanism(s) involved. We found that P2X7 was highly expressed in murine small luteal cells. The agonists of P2X7, ATP and BzATP, inhibited the proliferation of luteal cells. P2X7 antagonist BBG reversed the inhibition induced by ATP and BzATP. Further studies showed that ATP and BzATP inhibited the expression of cell cycle regulators cyclinD2 and cyclinE2. ATP and BzATP also inhibited the p38-mitogen-activated protein kinase (MAPK) signalling pathway. These results reveal that P2X7 receptor activation is involved in corpus luteum formation and function.

Upregulation of HO-1 Attenuates LPS-Stimulated Proinflammatory Responses Through Downregulation of p38 Signaling Pathways in Rat Ovary

Heme oxygenase-1 (HO-1) plays a key role in the regulation of the inflammatory response. However, the specific mechanism underlying the anti-inflammatory role of HO-1 in the reproductive system is unclear. The aim of this study was to evaluate the role of the mechanism of HO-1 in the regulation of the inflammatory response stimulated by lipopolysaccharide (LPS) in rat ovary. LPS-stimulated inflammatory models were established. Rats were pretreated with HO-1 activator (hemin) or inhibitor (ZnPP) before LPS stimulation, and we evaluated the expression of HO-1 by real-time PCR and Western blot. The messenger RNA (mRNA) expression and secretion of IL-1β and IL-6 in rat ovary were analyzed using real-time PCR and ELISA. In addition, we also analyzed the p38 and p-p38 protein expression in the ovary. Our results demonstrate that HO-1 is an anti-inflammatory factor in LPS-stimulated ovary, which regulates the inflammatory response through downregulation of p38 signaling pathways in rat ovary.

Evaluation of HO-1 expression, cellular ROS production, cellular proliferation and cellular apoptosis in human esophageal squamous cell carcinoma tumors and cell lines

Patients with esophageal squamous cell carcinoma (ESCC) have a poor prognosis. However, the related mechanisms are unclear, thus we investigated the expression of HO-1 in ESCC tissue and explored possible mechanisms of tumor progression. Expression of HO-1 was examined by immunohistochemistry in 143 ESCC tumors. The correlation of HO-1 with clinicopathological characteristics was also examined. Two human ESCC cell lines, TE-13 and Eca109 were studied. Silencing of cell line HO-1 by specific small interfering RNA (siRNA) was evaluated using real-time quantitative PCR. Cell line viability, apoptosis and intracellular levels of reactive oxygen species (ROS) after transfection were determined using MTT and flow cytometry, respectively. HO-1, Bax, Bcl-2 and A-caspase-3/-9 expression was evaluated using western blot analyses. We found that HO-1 was expressed in 58 of 143 ESCC tumors, mainly in the cytoplasm. There was a significant association between HO-1 expression and tumor grade (P<0.001). Knockdown of HO-1 expression in cell lines was associated with significantly decreased cellular proliferation (P<0.05) and a higher rate of apoptosis (P<0.001) 48 h after treatment. Treatment of the cell lines with the ROS inhibitor N-acetylcysteine abrogated this effect. Knockdown of HO-1 was associated with increased A-caspase-3 and -9 expression, but no change in Bax or Bcl-2 expression or Bax/Bcl-2 ratio was observed. Thus, the present study identified that ESCC tumors frequently expressed HO-1. Knockdown of HO-1 promoted apoptosis through activation of a ROS-mediated caspase apoptosis pathway.