Oxidative Stress Induced Growth Inhibitor Research Articles

Methylmercury Induces Apoptosis in Mouse C17.2 Neural Stem Cells through the Induction of OSGIN1 Expression by NRF2.

Methylmercury is a known environmental pollutant that exhibits severe neurotoxic effects. However, the mechanism by which methylmercury causes neurotoxicity remains unclear. To date, we have found that oxidative stress-induced growth inhibitor 1 (OSGIN1), which is induced by oxidative stress and DNA damage, is also induced by methylmercury. Therefore, in this study, we investigated the relationship between methylmercury toxicity and the induction of OSGIN1 expression using C17.2 cells, which are mouse brain neural stem cells. Methylmercury increased both OSGIN1 mRNA and protein levels in a time- and concentration-dependent manner. Moreover, these increases were almost entirely canceled out by pretreatment with actinomycin D, a transcription inhibitor. Furthermore, similar results were obtained from cells in which expression of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) was suppressed, indicating that methylmercury induces OSGIN1 expression via NRF2. Methylmercury causes neuronal cell death by inducing apoptosis. Therefore, we next investigated the role of OSGIN1 in methylmercury-induced neuronal cell death using the activation of caspase-3, which is involved in apoptosis induction, as an indicator. As a result, the increase in cleaved caspase-3 (activated form) induced by methylmercury exposure was decreased by suppressing OSGIN1, and the overexpression of OSGIN1 further promoted the increase in cleaved caspase-3 caused by methylmercury. These results suggest, for the first time, that OSGIN1 is a novel factor involved in methylmercury toxicity, and methylmercury induces apoptosis in C17.2 cells through the induction of OSGIN1 expression by NRF2.

Tim-3 deficiency aggravates cadmium nephrotoxicity via regulation of NF-κB signaling and mitochondrial damage

Kidney is the target organ of serious cadmium injury. Kidney damage caused by cadmium exposure is greatly influenced by the inflammatory response and mitochondrial damage. T cell immunoglobulin domain and mucin domain 3 (Tim-3) is an essential protein that functions as a negative immunological checkpoint to regulate inflammatory responses. Mice were given cadmium treatments at various dosages (0, 1.5, 3, 4.5 mg/kg) and times (0, 3, 5, 7 days) to assess the effects of cadmium on kidney damage. We found that the optimal way to induce kidney injury in mice was to inject 4.5 mg/kg of cadmium intraperitoneally for five days. It is interesting that giving mice 4.5 mg/kg of cadmium intravenously for seven days drastically lowered their survival rate. After cadmium exposure, Tim-3 knockout mice exhibited higher blood concentrations of urea nitrogen and creatinine compared to control mice. Tim-3 impacted the expression of oxidative stress-associated genes such as UDP glucuronosyltransferase family 1 member A9 (Ugt1a9), oxidative stress-induced growth inhibitor 2 (Osgin2), and S100 calcium binding protein A8 (S100a8), according to RNA-seq and real-time RT-PCR data. Tim-3 deficiency also resulted in activated nuclear factor-kappa B (NF-κB) signaling pathway. The NF-κB inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) significantly alleviated cell apoptosis, oxidative stress response, and renal tubule inflammation in Tim-3 knockout mice exposed to cadmium. Furthermore, cadmium caused obvious B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) translocation from cytoplasm to mitochondria, which can be inhibited by TPCA-1. In conclusion, Tim-3 prevented mitochondrial damage and NF-κB signaling activation, hence providing protection against cadmium nephrotoxicity.

Roles for Heme Synthesis in the Maintenance of Hematopoietic Stem and Progenitor Cells

Heme is required not only in red blood cells for oxygen transport but also in non-erythroid cells for the proper function of hemoproteins. Cytochrome c is one of the hemoproteins and inevitable for mitochondrial oxidative phosphorylation, suggesting that heme possesses important roles for ATP synthesis and mitochondria maintenance. Heme also can skew the differentiation of hematopoietic stem and progenitor cells (HSPCs) by altering the functions of transcription factors. Recent CRISPR Cas9 dropout screens repeatedly showed that some of the heme synthases, such as CPOX, might be inevitable for the survival and/or proliferation of HSPCs. However, still little is known about the roles for heme synthesis in the maintenance (survival, proliferation and differentiation) of HSPCs. To reveal the roles for heme synthesis in HSPCs in vivo, we developed polyI:C inducible hematopoietic cell specific Cpox knock-out mice ( Cpox f/f; Mx1-Cre). PolyI:C treated Cpox f/f; Mx1-Cre mice (KO mice) showed significant increase in the numbers of hematopoietic stem cells (HSCs) and multipotent stem and progenitor cells (MPP2s and MPP3s) but decrease in the numbers of common myeloid progenitors (CMPs) and some of their progenies (i.e., Gr1 positive cells and platelets). In contrast, its effects on erythroid and lymphoid lineages were limited. This result suggests that heme synthesis inhibition in HSPCs (HSCs, MPP2 and MPP3s) can cause their differentiation arrest. On the other hand, competitive transplantation analysis of LSKs (lineage -sca1 +c-kit +) or HSCs revealed that myelopoiesis were markedly decreased compared to control, suggesting that heme synthesis in HSPCs is important for the proper reconstitution of hematopoiesis. These results indicate that cell intrinsic heme synthesis is inevitable for the maintenance of HSPCs and their lineage specific output in vivo. In depth, we revealed that mitochondrial respiratory activity of Cpox KO HSCs were increased compared to control HSCs, suggesting that alterations of mitochondrial status and/or functions by the inhibition of heme synthesis might contribute to the aberrance in Cpox KO HSPCs. Comprehensive gene expression analysis is now ongoing to support this notion. To further reveal the roles for heme synthesis in human HSPCs, we treated human leukemia cell lines (MV4-11, KG1a and U937) with heme synthesis inhibitors (SA or NMPP). Concentration-dependent cell growth inhibitory effect and cell death were observed with increased apoptosis factors (cleaved caspase 3 and cleaved PARP), suggesting that heme synthesis inhibition triggered apoptosis. We also revealed that CPOX inhibition under doxycycline inducible CRISPR Cas9 system caused cell growth inhibitory effect and cell death in these cells. Second mitochondria-derived activator of caspases (Smac) and cytochrome c were released to cytoplasm, and the inhibitor of apoptosis protein (XIAP) was decreased by heme synthesis inhibitions. Therefore, caspase-3 activation by accumulation of cytoplasmic cytochrome c and Smac might be the inducer of this apoptosis pathway. Comprehensive transcriptomic analysis (RNA-seq) revealed that heme synthesis inhibition induced the release of cytochrome c and Smac from mitochondria into cytoplasm by the transcriptomic upregulation of Oxidative Stress Induced Growth Inhibitor 1 (Osgin1) that is the known target of NRF2. Collectively, this study demonstrated the significance of heme synthesis in the maintenance of HSPCs especially in vivo (mouse) and in vitro (human). Dysfunctions of heme synthesis in HSPCs can cause their aberrance by the alterations in their mitochondrial status which can cause apoptosis and/or differentiation arrest. Considering the metabolic differences (i.e., demands for mitochondrial oxidative phosphorylation and subsequent ATP synthesis) between normal HSPCs and leukemia or unperturbed hematopoiesis and perturbed hematopoiesis (i.e., infections and hematopoietic stem cell transplantations), further analysis to reveal the roles for heme synthesis in the maintenance of HSPCs will pave the way to establish optical approaches in these clinical settings.

Protective effect of ethyl ferulate against hypoxic injury in retinal cells and retinal neovascularization in an oxygen-induced retinopathy model

BackgroundPathological neovascularization is a major cause of visual impairment in hypoxia-induced retinopathy. Ethyl ferulate (EF), the natural ester derivative of ferulic acid commonly found in Ferula and Angelica Sinensis, has been shown to exert antioxidant, neuroprotective, and anti-inflammatory properties. However, whether EF exerts a protective effect on retinal neovascularization and the underlying mechanisms are not well known. PurposeThe aim of the study was to investigate the effect of EF on retinal neovascularization and explore its underlying molecular mechanisms. Study-design/methodsWe constructed hypoxia models induced by cobalt chloride (CoCl2) in ARPE-19 cells and Rhesus choroid-retinal vascular endothelial (RF/6A) cells in vitro, as well as a retinal neovascularization model in oxygen-induced retinopathy (OIR) mice in vivo. ResultsIn this work, we demonstrated that EF treatment inhibited hypoxia-induced vascular endothelial growth factor A (VEGFA) expression in ARPE-19 cells and abrogated hypoxia-induced tube formation in RF/6A cells. As expected, intravitreal injection of EF significantly suppressed retinal neovascularization in a dose-dependent manner in OIR retinas. We also found that hypoxia increased VEGFA expression by blocking autophagic flux, whereas EF treatment enhanced autophagic flux, thereby reducing VEGFA expression. Furthermore, EF activated the sequestosome 1 (p62) / nuclear factor E2-related factor 2 (Nrf-2) pathway via upregulating oxidative stress-induced growth inhibitor 1 (OSGIN1) expression, thus alleviating oxidative stress and reducing VEGFA expression. ConclusionAs a result of our findings, EF has an inhibitory effect on retinal neovascularization, implying a potential therapeutic strategy for hypoxia-induced retinopathy.

OSGIN1 is a novel TUBB3 regulator that promotes tumor progression and gefitinib resistance in non-small cell lung cancer.

Oxidative stress induced growth inhibitor 1 (OSGIN1) regulates cell death. The role and underlying molecular mechanism of OSGIN1 in non-small cell lung cancer (NSCLC) are uncharacterized. OSGIN1 expression in NSCLC samples was detected using immunohistochemistry and Western blotting. Growth of NSCLC cells and gefitinib-resistant cells expressing OSGIN1 or TUBB3 knockdown was determined by MTT, soft agar, and foci formation assays. The effect of OSGIN1 knockdown on in vivo tumor growth was assessed using NSCLC patient-derived xenograft models and gefitinib-resistant patient-derived xenograft models. Potentially interacting protein partners of OSGIN1 were identified using IP-MS/MS, immunoprecipitation, PLA, and Western blottingassays. Microtubule dynamics were explored by tubulin polymerization assay and immunofluorescence. Differential expression of signaling molecules in OSGIN1 knockdown cells was investigated using phospho-proteomics, KEGG analysis, and Western blotting. We found thatOSGIN1 is highly expressed in NSCLC tissues and is positively correlated with low survival rates and tumor size in lung cancer patients. OSGIN1 knockdown inhibited NSCLC cell growth and patient-derived NSCLC tumor growth in vivo. Knockdown of OSGIN1 strongly increased tubulin polymerization and re-established gefitinib sensitivity in vitro and in vivo. Additionally, knockdown of TUBB3 strongly inhibited NSCLC cell proliferation. Mechanistically, we found that OSGIN1 enhances DYRK1A-mediated TUBB3 phosphorylation, which is critical for inducing tubulin depolymerization. The results of phospho-proteomics and ontology analysis indicated that knockdown of OSGIN1 led to reduced propagation of the MKK3/6-p38 signaling axis. We propose that OSGIN1 modulates microtubule dynamics by enhancing DYRK1A-mediated phosphorylation of TUBB3 at serine 172. Moreover, elevated OSGIN1 expression promotes NSCLC tumor growth and gefitinib resistance through the MKK3/6-p38 signaling pathway. Our findings unveil a new mechanism of OSGIN1 and provide a promising therapeutic target for NSCLC treatment in the clinic.

Clinical prognostic value of OSGIN2 in gastric cancer and its proliferative effect in vitro

This study explored the promoting effect of oxidative stress-induced growth inhibitor family member 2(OSGIN2) on gastric cancer (GC) through public databases and in vitro experiments. The potential relationship between OSGIN2 expression, prognosis, functional enrichment of associated differential genes, immune infiltration, and mutational information in gastric cancer were comprehensively investigated using bioinformatics analysis. OSGIN2 was knocked down using small interfering RNA (siRNA) transfection for subsequent cell function testing. The results showed that gastric carcinoma cells and tissues contained high levels of OSGIN2, which was associated with a poor prognosis for GC patients. It was important in the cell cycle, autophagy, etc., and was related to a variety of tumor-related signal pathways. Knockdown of OSGIN2 inhibited tumor cell proliferation and contributed to cell cycle arrest. It was also correlated with tumor immune infiltrating cells (TILs), affecting antitumor immune function. Our analysis highlights that OSING2, as a new biomarker, has diagnostic and prognostic value in gastric cancer and is a potentially effective target in GC treatment.

Structured Illumination Microscopy of Mitochondrial in Mouse Hepatocytes with an Improved Image Reconstruction Algorithm.

In this paper, a structured illumination microscopy (SIM) image reconstruction algorithm combined with notch function (N-SIM) is proposed. This method suppresses the defocus signal in the imaging process by processing the low-frequency signal of the image. The existing super-resolution image reconstruction algorithm produces streak artifacts caused by defocus signal. The experimental results show that the algorithm proposed in our study can well suppress the streak artifacts caused by defocused signals during the imaging process without losing the effective information of the image. The image reconstruction algorithm is used to analyze the mouse hepatocytes, and the image processing tool developed by MATLAB is applied to identify, detect and count the reconstructed images of mitochondria and lipid droplets, respectively. It is found that the mitochondrial activity in oxidative stress induced growth inhibitor 1 (OSGIN1) overexpressed mouse hepatocytes is higher than that in normal cells, and the interaction with lipid droplets is more obvious. This paper provides a reliable subcellular observation platform, which is very meaningful for biomedical work.

Nodosin Exerts an Anti-Colorectal Cancer Effect by Inhibiting Proliferation and Triggering Complex Cell Death in Vitro and in Vivo

Colorectal cancer (CRC) is one of the most common digestive system cancer in the world. Its incidence and mortality are increasing annually. Presently, CRC lacks long-term effective treatment methods and drugs. Therefore, finding new treatment methods and drugs is of great significance for CRC treatment. Compounds derived from natural plants have been widely used in tumor research and treatment because of their good antitumor activity these years. This study found that nodosin, a diterpenoid extracted from the medicinal plant Rabdosia serra (Maxim.) Hara, inhibited the growth of CRC cells SW480, HT-29 and LoVo in a dose- and time-dependent manner, with inhibitory concentrations (IC50) of 7.4, 7.7, and 6.6 μM respectively. We selected highly metastatic and poorly differentiated SW480 cells for further studies. We found that nodosin could inhibit cell proliferation by inhibiting DNA synthesis and induce cell death by inducing oxidative stress, apoptosis and autophagy in cells. Through in vitro assays combined with transcriptomic analysis, it was found that nodosin could downregulate tribbles pseudokinase 3 and upregulate oxidative stress-induced growth inhibitor 1 to induce oxidative stress in cells; nodosin-induced reactive oxygen species were able to upregulate the expression of heme oxygenase 1 to induce apoptosis and the expression of cathepsin L. and light chain-3 to induce autophagy. In vivo, we found that nodosin inhibited tumor growth and induced cells to undergo apoptosis and autophagy without significant toxic effects. In conclusion, our findings suggest that nodosin exerts anti-CRC effects mainly through its ability to induce apoptosis and autophagy in vitro and in vivo. Therefore, our study contributes to the development of nodosin-based potential CRC therapeutic drugs.

Comparative study of oxidative status and some biochemical parameters in subjects suffered of intermediate and major Thalassemia

In the β-thalassemia’s, oxidative stress, resulting from chronic hemolysis, globin chain imbalance, iron overload and depleted antioxidant defenses, likely contributes to cell death, organ damage, anemia, hypoxia and inflammation. Between November 2020 and June 2021, the study assessed adults aged (25-35 years) attending to Hiwa Cancer Hospital/ Sulaimaniah Thalassemia and congenital blood disorders center/ Iraq: 60 patients with HbE β-thalassemia, 30 β-thalassemia major, 30 β-thalassemia intermediate and 30 control subjects. ferritin were measured as sources of oxidants; plasma antioxidants: Glutathione Reductase (GR) and Oxidative stress-induced growth inhibitor 2 (OSGIN2) , plasma D-dimer assessed thrombosis status and serum C-reactive protein assessed inflammation, the results showed increased in the levels of ferritin, plasma D-dimer and CRP in both β-thalassemia major and β-thalassemia intermediate (2789±789 ; 2657±725.8 ng/ml) , (175.4±54.02; 188.7±62.01 ng/ml) and (15.6±2.6; 13.3±3.1 mg/l) compared to control group (178.7±58.9 ng/ml) , (79.8±34.8 ng/ml) and (2.3± 0.7 mg/l) respectively. Whereas decreased in the levels of GR and OSGIN2 (38.4±12.7; 35±8.8 pg/ml) and (58±18.3; 78±20.5 mg/dl) compared to control group (96±17.3 pg/ml) and (156±65.6 mg/dl ) respectively.

Oxidative Stress-Induced Growth Inhibitor (OSGIN1), a Target of X-Box-Binding Protein 1, Protects Palmitic Acid-Induced Vascular Lipotoxicity through Maintaining Autophagy.

Saturated free fatty acids (FFAs) strongly correlate with metabolic syndromes and are well-known risk factors for cardiovascular diseases (CVDs). The mechanism of palmitic acid (PA)-induced vascular lipotoxicity under endoplasmic reticulum (ER) stress is unknown. In the present paper, we investigate the roles of spliced form of X-box-binding protein 1 (XBP1s) target gene oxidative stress-induced growth inhibitor 1 (OSGIN1) in PA-induced vascular dysfunction. PA inhibited the tube formation assay of primary human umbilical vein endothelial cells (HUVECs). Simultaneously, PA treatment induced the XBP1s expression in HUVECs. Attenuate the induction of XBP1s by silencing the XBP1s retarded cell migration and diminished endothelial nitric oxide synthase (eNOS) expression. OSGIN1 is a target gene of XBP1s under PA treatment. The silencing of OSGIN1 inhibits cell migration by decreasing phospho-eNOS expression. PA activated autophagy in endothelial cells, inhibiting autophagy by 3-methyladenine (3-MA) decreased endothelial cell migration. Silencing XBP1s and OSGIN1 would reduce the induction of LC3 II; therefore, OSGIN1 could maintain autophagy to preserve endothelial cell migration. In conclusion, PA treatment induced ER stress and activated the inositol-requiring enzyme 1 alpha–spliced XBP1 (IRE1α–XBP1s) pathway. OSGIN1, a target gene of XBP1s, could protect endothelial cells from vascular lipotoxicity by regulating autophagy.

Mitochondrial-bound hexokinase 1 can affect the glucolipid metabolism and reactive oxygen species production in goose fatty liver

To investigate the functions of hexokinase 1 (HK1) in the formation of goose fatty liver, a total of 40 healthy 63-day-old male Landes geese were selected and randomly assigned to a control group and an overfeeding treatment. In addition, the overexpression or RNA interference assay of HK1, and transcriptome analysis after HK1 overexpression were performed in the goose primary hepatocytes. Data showed that the mRNA expression of hepatic HK1 was upregulated in overfed treatment compared to control on the 19 days of overfeeding. The expression of HK1 was increased in 50 mM glucose treatment in hepatocytes. Moreover, overexpression of HK1 tended to increase the relative lipid accumulation level and had weakened fluorescence intensity of reactive oxygen species (ROS), while knockdown of HK1 resulted in a tendency of relative lipid content decrease and had enhanced fluorescence intensity of ROS in cells in comparison to the control. The verification of transcriptome analysis indicated that the expression of ceruloplasmin (CP), acyl-CoA dehydrogenase medium-chain (ACADM), phosphoglucomutase 2 (PGM2), and phospholipase A2 group IVA (PLA2G4A) was significantly induced by HK1 overexpression, while that of enoyl-CoA hydratase, short chain 1 (ECHS1), cytochrome P450 family 2 subfamily C member 19 (CYP2C19), carnitine palmitoyltransferase 1 A (CPT1A), and oxidative stress-induced growth inhibitor 1 (OSGIN1) was inhibited. In summary, HK1 could promote fat deposition by affecting the process of glucolipid metabolism in the formation of goose fatty liver. Additionally, HK1 might decrease the ROS level in hepatocytes by regulating the expression of redox-related genes. HIGHLIGHTS The HK1 gene may promote the goose fatty liver production. The HK1 gene may be used as a research target to decrease the reactive oxygen species level in fatty liver.

Oxidative stress-induced growth inhibitor 1 in alcohol-induced liver cirrhosis.

Human oxidative stress-induced growth inhibitor 1 (OSGIN1) is a protein identified in 2001 which belongs to the OKL38 protein family. The aim of the study was to investigate the levels of this protein depending on the severity of alcohol-induced liver cirrhosis. The study group consisted of 60 patients: 30 patients with cirrhosis in the P-Ch A and B stage and 30 in the P-Ch C stage. The control group consisted of 18 healthy individuals without liver diseases, who did not abuse alcohol. Oxidative stress induced growth inhibitor 1 (OSGIN1), fibroblast growth factor 1 (FGF1) and fibroblast growth factor 21 (FGF21) were determined in blood serum using enzyme-linked immunosorbent assay (ELISA) kits. All absorbance readings were conducted using an Epoch Microplate Spectrophotometer (BioTek Instrumentals, Inc., Winooski, VT, USA). OSGIN1, FGF1 and FGF21 concentrations were determined using Sandwich enzyme immunoassay kits (by Cloud Clone Corp., Katy, TX, USA). Statistica 13.3 (TIBCO Software, Inc.) was used for data analysis. The concentration of OSGIN1 was 0.028 ± 0.017 in the control group which increased with the advancement of liver cirrhosis (stage of Pugh-Child): 0.075 ± 0.098 in the P-Ch A + B group and 0.121 ± 0.134 in the P-Ch C stage. Multiple comparison tests confirmed statistically significant differences in OSGIN1 concentration between the control group and P-Ch C (p <0.02). Significant correlations were noted between OSGIN1 and FGF1 (r = 0.39; p = 0.004) and between OSGIN1 and FGF21 (r = 0.53; p <0.0001). The study revealed that the level of OSGIN1 increased significantly in the P-Ch C stage of liver cirrhosis. It is possible that OSGIN1 may be used for the non-invasive diagnosis of ALD, but its possible diagnostic value is still very uncertain.

Club Cells Are the Primary Target for Permethrin-Induced Mouse Lung Tumor Formation.

Permethrin has been shown to increase lung adenomas in female CD-1 mice, but not in male mice or Wistar rats. The proposed mode of action (MOA) for permethrin-induced female mouse lung tumor formation involves morphological changes in Club cells; increased Club cell proliferation; increased Club cell hyperplasia, and lung tumor formation. In this study, the treatment of female CD-1 mice with tumorigenic doses (2500 and 5000 ppm) of permethrin, but not with a nontumorigenic dose (20 ppm), for 14 and/or 28 days increased Club cell replicative DNA synthesis. Global gene expression analysis of female mouse lung samples demonstrated that permethrin treatment up-regulated 3 genes associated with cell proliferation, namely aldehyde dehydrogenase 3a1 (Aldh3a1), oxidative stress-induced growth inhibitor 1, and thioredoxin reductase 1. Treatment with 2500 and 5000 ppm, but not 20 ppm, permethrin for 7 days produced significant increases in mRNA levels of these 3 genes. Immunohistochemical analysis demonstrated that Club cell secretory protein, CYP2F2, and ALDH3A1 colocalized in Club cells; confirmed by flow cytometry analysis of lung cells employing KI67 as a cell proliferation marker. Overall, the present data extend the proposed MOA by demonstrating that Club cells are the primary initial target of permethrin administration in female mouse lungs. As humans are quantitatively much less sensitive to agents that increase Club cell proliferation and lung tumor formation in mice, it is most likely that permethrin could not produce lung tumors in humans. This conclusion is supported by available negative epidemiological data from several studies.

Docosahexaenoic acid promotes the formation of autophagosomes in MCF-7 breast cancer cells through oxidative stress-induced growth inhibitor 1 mediated activation of AMPK/mTOR pathway

Docosahexaenoic acid (DHA) is known to regulate autophagy in cancer cells. We explored whether oxidative stress-induced growth inhibitor 1 (OSGIN1) is involved in the regulation of autophagy by DHA in breast cancer cells and the possible mechanisms involved. DHA upregulated the levels of OSGIN1, LC3-II and SQSTM1/p62. By contrast, DHA dose-dependently decreased the levels of mTOR and p-mTORS2448 expression. Using GFP/RFP-LC3 fluorescence staining, we showed that cells treated with DHA showed a dose-dependent response in autophagic signals. OSGIN1 Overexpression mimicked DHA treatment in that LC3-II and GFP/RFP-LC3 signals as well as the expression of p-AMPKαT172 and p-RaptorS792 were significantly increased, whereas mTOR, p-mTORS2448, and p-ULK1S757 expression were decreased. With knockdown of OSGIN1 expression, these outcomes were reversed. Moreover, OSGIN1 overexpression transiently elevated the accumulation of OSGIN1 and reactive oxygen species (ROS) in the mitochondrial fraction and subsequently increased p-AMPKαT172 and p-RaptorS792 expression. Upon pretreatment with Mito-TEMPO, a scavenger of mitochondrial ROS, these outcomes were reversed. Taken together, these results suggest that DHA can transiently elevate the generation of ROS in mitochondria and promote autophagosome formation through activation of the p-AMPKαT172/p-Raptor S792 and inactivation of the p-mTORS2448/p-ULK1Ser757 signaling pathways, and these effects depend on OSGIN1 protein in MCF-7 cells.

METTL3 regulates PM2.5-induced cell injury by targeting OSGIN1 in human airway epithelial cells

N6-methyladenosine (m6A) is implicated in alteration of cellular biological processes caused by exogenous environmental factors. However, little is known about the role of m6A in airborne fine particulate matter (PM2.5)-induced adverse effects. Thus, we investigated the role of m6A modification in PM2.5-induced airway epithelial cell injury. We observed a methyltransferase-like 3 (METTL3)-dependent induction of m6A modification after PM2.5 treatment in HBE and A549 cells. METTL3 knockdown attenuated PM2.5-induced apoptosis and arrest of cell cycle. mRNA sequencing and RNA N6-methyladenosine binding protein immunoprecipitation (Me-RIP) assay identified m6A-modified oxidative stress induced growth inhibitor 1 (OSGIN1) as the target gene of METTL3. Knockdown of METTL3 resulted a shorter mRNA half-life of OSGIN1 by catalyzing its m6A modification. Knockdown of METTL3 or OSGIN1 attenuated cell apoptosis, arrest of cell cycle and autophagy induced by PM2.5. In conclusion, METTL3 may mediate PM2.5-induced cell injury by targeting OSGIN1 in human airway epithelial cells. Our work uncovered a critical role of METTL3 in PM2.5-induced airway epithelial cell injury and provided insight into the vital role of m6A modification in PM2.5-induced human hazards.

Effectiveness of drugs with delayed-release structurally modified action depending on the phenotype of osteoarthritis

Aim. To evaluate the effectiveness of a fixed combination of honadroitin and glucosamine sulfate (Teraflex, Bayer) in the treatment of osteoarthritis (OA), depending on the molecular phenotype of the disease.Materials and methods. A 6-month prospective, open, randomized trial included 65 patients with OA of the knee joints who were prescribed therapy with Teraflex (Bayer) daily dose of 1500 mg + 1200 mg. Kinetic assessment of articular status was performed using a visual analogue pain scale and a WOMAC questionnaire, and serum concentrations of CRTAP (cartilage-associated protein), OSGIN-1 (oxidative stress-induced growth inhibitor 1), IL-1β (interleukin-1 beta) were determined in blood serum. Measurements of these parameters were made at the beginning of the study, after 3 and 6 months.Results. It was established that the rate of onset of the therapeutic effect and the effect on the molecular patterns of inflammation and oxidative stress depend on the phenotype of the disease. So, with oxidative and mixed phenotypes of the disease, clinical efficacy is observed in the treatment of teraflex after 3 months from the start of therapy. Indicators of oxidative stress during treatment decreased in the group of patients with the oxidative phenotype of the disease, while the level of interleukin-1 significantly decreased only in groups of patients with inflammatory and mixed OA phenotypes.Conclusions. The results indicate the effectiveness and safety of the drug Teraflex (Bayer) for the treatment of patients with OA. The results of the study indicate the targeted effect of a fixed combination of chondroitin + glucosamine on the molecular mechanisms of the disease.

Stra8 may inhibit apoptosis during mouse spermatogenesis via the AKT signaling pathway.

Stimulated by retinoic acid8 (Stra8), one of genes induced by retinoic acid (RA), is required for the meiotic initiation of male spermatogenesis. The present study found that Stra8 inhibited apoptosis in male Stra8‑knockout mice, and in mice with vitamin A deficiency and vitamin A recovery invivo. This phenotype was also verified in GC1 spermatogonia (spg) cells overexpressing Stra8. In addition, microarray analysis identified that there were nine differentially expressed genes (DEGs) in the Stra8‑overexpressed GC1 spg cells compared with the control groups; the expression of these nine genes was verified via mRNA expression levels. The DEGs were as follows: Phosphatidylinositol‑dependent kinase1 (PDK1), a key gene upstream of protein kinase B (AKT); angiopoietin2, a B‑cell lymphoma 2 (Bcl‑2)‑inhibited gene; transcription factor4, glutathione S‑transferase P91 and ubiquitin‑specific protease33, mitogen‑activated protein kinase (MAPK)‑related genes; oxidative stress induced growth inhibitor1, related to the P53 pathway; Bcl‑2, P53, ERK (MAPK1/3), c‑Jun N‑terminal kinase (MAPK8/9), and P38 (MAPK14), all of which are key genes involved in the AKT signaling pathway. Therefore, the present study further verified these genes and found that the mRNA and protein expression levels of PDK1, AKT, Bcl‑2 and ERK were increased. Although the mRNA expression level of P53 was decreased, there was no significant difference in the protein expression level in Stra8‑overexpressing GC1 spg cells compared with controls. In addition, Caspase3, one of the executioner caspases, was decreased in Stra8‑overexpressing GC1 spg cells compared with the control groups. Therefore, it was suggested that Stra8 may directly or indirectly inhibit caspases through the AKT signaling pathway and ultimately exert an anti‑apoptotic effect in the male reproductive system.

LncRNA UCA1 attenuates autophagy-dependent cell death through blocking autophagic flux under arsenic stress

Arsenic (As) is a naturally toxin which exists ubiquitously in foods and various environment media, incurring diverse toxicities and health problems. Previous studies have shown that oxidative stress, genotoxic damage and pro-apoptotic pathways are ascribed to As-associated detrimental effects. Meanwhile, epigenetic regulations (such as miRNAs and histone modifications) were also reported to contribute to As-induced adverse effects. Nonetheless, whether long non-coding RNAs (LncRNAs) are indispensable for the regulation of As-induced biological outcomes are nearly unknown. In this study, we identified that a lncRNA UCA1 was markedly induced by As treatment in human hepatocytes. Functional assessments revealed that UCA1 played a critical role in protecting hepatocytes from As-induced autophagy inhibition. Furthermore, through RNA-seq assay, oxidative stress induced growth inhibitor 1 (OSGIN1) was uncovered to be the most responsive target downstream of UCA1, and miR-184 acted as an intermediate for the regulation of UCA1 on the level of OSGIN1 through a competing endogenous RNAs (ceRNAs) mechanism. Further mechanistic investigations demonstrated that UCA1/OSGIN1 signaling contributed to As-induced autophagic flux blockage through activating mTOR/p70S6 K cascade, resulting in compromised cell death. Collectively, our study deciphered a lncRNA-dictated molecular mechanism responsible for As toxicity: UCA1 leads a protective role against As-induced cell death through blocking autophagic flux.

Docosahexaenoic acid increases the expression of oxidative stress-induced growth inhibitor 1 through the PI3K/Akt/Nrf2 signaling pathway in breast cancer cells

Oxidative stress-induced growth inhibitor 1 (OSGIN1), a tumor suppressor, inhibits cell proliferation and induces cell death. N-6 and n-3 PUFAs protect against breast cancer, but the molecular mechanisms of this effect are not clear. We investigated the effect of n-6 and n-3 PUFAs on OSGIN1 expression and whether OSGIN1 is involved in PUFA-induced apoptosis in breast cancer cells. We used 100 μM of n-6 PUFAs including arachidonic acid, linoleic acid, and gamma-linolenic acid and n-3 PUFAs including alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid (DHA). Only DHA significantly induced OSGIN1 protein and mRNA expression. DHA triggered reactive oxygen species (ROS) generation and nuclear translocation of Nrf2. LY294002, a PI3K inhibitor, suppressed DHA-induced OSGIN1 protein expression and nuclear accumulation of Nrf2. Nrf2 knockdown attenuated DHA-induced OSGIN1 expression. N-Acetyl-l-cysteine, a ROS scavenger, abrogated the DHA-induced increases in Akt phosphorylation, Nrf2 nuclear accumulation, and OSGIN1 expression. DHA induced the Bax/Bcl-2 ratio, mitochondrial accumulation of OSGIN1 and p53, and cytochrome c release; knockdown of OSGIN1 diminished these effects. In conclusion, induction of OSGIN1 by DHA is at least partially associated with increased ROS production, which activates PI3K/Akt/Nrf2 signaling. Induction of OSGIN1 may be involved in DHA-induced apoptosis in breast cancer cells.

Role of OSGIN1 in mediating smoking-induced autophagy in the human airway epithelium

ABSTRACTEnhanced macroautophagy/autophagy is recognized as a component of the pathogenesis of smoking-induced airway disease. Based on the knowledge that enhanced autophagy is linked to oxidative stress and the DNA damage response, both of which are linked to smoking, we used microarray analysis of the airway epithelium to identify smoking upregulated genes known to respond to oxidative stress and the DNA damage response. This analysis identified OSGIN1 (oxidative stress induced growth inhibitor 1) as significantly upregulated by smoking, in both the large and small airway epithelium, an observation confirmed by an independent small airway microarray cohort, TaqMan PCR of large and small airway samples and RNA-Seq of small airway samples. High and low OSGIN1 expressors have different autophagy gene expression patterns in vivo. Genome-wide correlation of RNAseq analysis of airway basal/progenitor cells showed a direct correlation of OSGIN1 mRNA levels to multiple classic autophagy genes. In vitro cigarette smoke extract exposure of primary airway basal/progenitor cells was accompanied by a dose-dependent upregulation of OSGIN1 and autophagy induction. Lentivirus-mediated expression of OSGIN1 in human primary basal/progenitor cells induced puncta-like staining of MAP1LC3B and upregulation of MAP1LC3B mRNA and protein and SQSTM1 mRNA expression level in a dose and time-dependent manner. OSGIN1-induction of autophagosome, amphisome and autolysosome formation was confirmed by colocalization of MAP1LC3B with SQSTM1 or CD63 (endosome marker) and LAMP1 (lysosome marker). Both OSGIN1 overexpression and knockdown enhanced the smoking-evoked autophagic response. Together, these observations support the concept that smoking-induced upregulation of OSGIN1 is one link between smoking-induced stress and enhanced-autophagy in the human airway epithelium.