Resveratrol protects against deoxynivalenol-induced ferroptosis in HepG2 cells.

Deoxynivalenol (DON) is one of the most serious mycotoxins that contaminate food and feed, causing hepatocyte death. However, there is still a lack of understanding regarding the new cell death modalities that explain DON-induced hepatocyte toxicity. Ferroptosis is an iron-dependent type of cell death. The aim of this study was to explore the role of ferroptosis in DON-exposed HepG2 cytotoxicity and the antagonistic effect of resveratrol (Res) on its toxicity, and the underlying molecular mechanisms. HepG2 cells were treated with Res (8 µM) or/and DON (0.4 µM) for 12 h. We examined cell viability, cell proliferation, expression of ferroptosis-related genes, levels of lipid peroxidation and Fe(II). The results revealed that DON reduced the expression levels of GPX4, SLC7A11, GCLC, NQO1, and Nrf2 while promoting the expression of TFR1, GSH depletion, accumulation of MDA and total ROS. DON enhanced production of 4-HNE, lipid ROS and Fe(II) overload, resulting in ferroptosis. However, pretreatment with Res reversed these changes, attenuating DON-induced ferroptosis, improving cell viability and cell proliferation. Importantly, Res prevented Erastin and RSL3-induced ferroptosis, suggesting that Res exerted an anti-ferroptosis effect by activating SLC7A11-GSH-GPX4 signaling pathways. In summary, Res ameliorated DON-induced ferroptosis in HepG2 cells. This study provides a new perspective on the mechanism of DON-induced hepatotoxicity formation, and Res may be an effective drug to alleviate DON-induced hepatotoxicity.

Berbamine promotes macrophage autophagy to clear Mycobacterium tuberculosis by regulating the ROS/Ca2+ axis.

Drug-resistant tuberculosis (TB) poses a major threat to global TB control; consequently, there is an urgent need to develop novel anti-TB drugs or strategies. Host-directed therapy (HDT) is emerging as an effective treatment strategy, especially for drug-resistant TB. This study evaluated the effects of berbamine (BBM), a bisbenzylisoquinoline alkaloid, on mycobacterial growth in macrophages. BBM inhibited intracellular Mycobacterium tuberculosis (Mtb) growth by promoting autophagy and silencing ATG5, partially abolishing the inhibitory effect. In addition, BBM increased intracellular reactive oxygen species (ROS), while the antioxidant N-acetyl-L-cysteine (NAC) abolished BBM-induced autophagy and the ability to inhibit Mtb survival. Furthermore, the increased intracellular Ca2+ concentration induced by BBM was regulated by ROS, and BAPTA-AM, an intracellular Ca2+-chelating agent, could block ROS-mediated autophagy and Mtb clearance. Finally, BBM could inhibit the survival of drug-resistant Mtb. Collectively, these findings provide evidence that BBM, a Food and Drug Administration (FDA)-approved drug, could effectively clear drug-sensitive and -resistant Mtb through regulating ROS/Ca2+ axis-mediated autophagy and has potential as an HDT candidate for TB therapy. IMPORTANCE It is urgent to develop novel treatment strategies against drug-resistant TB, and HDT provides a promising approach to fight drug-resistant TB by repurposing old drugs. Our studies demonstrate, for the first time, that BBM, an FDA-approved drug, not only potently inhibits intracellular drug-sensitive Mtb growth but also restricts drug-resistant Mtb by promoting macrophage autophagy. Mechanistically, BBM activates macrophage autophagy by regulating the ROS/Ca2+ axis. In conclusion, BBM could be considered as an HDT candidate and may contribute to improving the outcomes or shortening the treatment course of drug-resistant TB.

MiR-29a-3p Inhibits Proliferation and Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells via Targeting FOXO3 and Repressing Wnt/ß-Catenin Signaling in Steroid-Associated Osteonecrosis.

Background and Objectives: This study was to investigate the role of microRNA-29a-3p (miR-29a-3p) in human bone marrow mesenchymal stem cells (hBMSCs), and its relationship with steroid-associated osteonecrosis. Methods and Results: The online tool GEO2R was used to screen out the differentially expressed genes (DEGs) in GSE123568 dataset. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-29a-3p, forkhead box O3 (FOXO3), alkaline phosphatase (ALP), bone gamma-carboxyglutamate protein (OCN) and RUNX family transcription factor 2 (Runx2) in the hBMSCs isolated from the patients with steroid- associated osteonecrosis. CCK-8 assay was executed to measure cell viability; western blot assay was utilized to detect FOXO3, ALP, Runx2, OCN and ß-catenin expression. Cell apoptosis and cell cycle were detected by flow cytometry. Immunofluorescence assay was used to detect the sub-cellular localization of ß-catenin. Bioinformatics analysis and luciferase reporter gene assay were performed to confirm whether miR-29a-3p can combine with FOXO3 3'UTR. MiR-29a-3p was markedly up-regulated in the hBMSCs of patients with steroid-associated osteonecrosis, while FOXO3 mRNA was significantly down-regulated. Transfection of miR-29a-3p mimics significantly inhibited the hBMSCs' proliferation, osteogenic differentiation markers' expressions, including ALP, Runx2, OCN, and repressed the ALP activity, as well as promoted cell apoptosis and cell-cycle arrest. FOXO3 was identified as a target gene of miR-29a-3p, and miR-29a-3p can inhibit the expression of FOXO3 and ß-catenin, and inhibition of miR-29a-3p promoted translocation of ß-catenin to the nucleus. Conclusions: MiR-29a-3p can modulate FOXO3 expression and Wnt/ß-catenin signaling to inhibit viability and osteogenic differentiation of hBMSCs, thereby promoting the development of steroid-associated osteonecrosis.

Nicotinamide N-methyltransferase protects against deoxynivalenol-induced growth inhibition by suppressing pro-inflammatory cytokine expression.

Deoxynivalenol (DON) is an inevitable contaminant in cereals for infants. Indeed, children's growth retardation caused by widespread DON pollution has become a global problem that cannot be ignored. Accumulating evidence has shown that DON stunts growth in children through pro-inflammatory cytokines. An exogenous increase of methylnicotinamide, a metabolite produced by nicotinamide N-methyltransferase (NNMT), has anti-inflammatory effects, but it is not clear whether NNMT has the same effect, and the role of NNMT in DON-induced inflammation and growth impairment remains indistinct. The present research reports that NNMT is an inflammatory self-protective factor in DON-exposed L02 cells. DON promoted the production of pro-inflammatory cytokines. Furthermore, DON increased NNMT to reduce pro-inflammatory cytokines, including interleukin (IL)-1ß, IL-11 and IL-6, and thus increased IGF-1 and cell viability, alleviating the cell growth inhibition induced by DON. Interestingly, NNMT negatively regulated the expression of IL-1ß through Sirtuin type 1 (SIRT1). Collectively, these findings provide new mechanistic insights into the toxicity of DON-induced growth retardation and inflammatory responses in children.

A "Janus" face of the RASSF4 signal in cell fate.

RASSF4 (Ras-association domain family 4) is a protein-coding gene, regarded as a tumor suppressor regulated by DNA methylation. However, RASSF4 acts as a "Janus" in cell fate: death and survival. This review article focuses on the regulatory mechanisms of RASSF4 on cell death and cell survival and puts forward a comprehensive analysis of the relevant signaling pathways. The participation of RASSF4 in the regulation of intracellular store-operated Ca2+ entry also affects cell survival. Moreover, the mechanism of inducing abnormal expression of RASSF4 was summarized. We highlight recent advances in our knowledge of RASSF4 function in the development of cancer and other clinical diseases, which may provide insight into the controversial functions of RASSF4 and its potential application in disease therapy.

The vasculature niches required for hematopoiesis.

Endothelial cells play a critical role in supporting postnatal hematopoiesis in the bone marrow. Unique endothelial cells, together with various perivascular cells, form different types of vascular structures, constructing a vast microvascular delivery and trafficking network for blood cells, oxygen, and nutrition. These blood vessels build distinct hematopoietic stem and progenitor cell niches, which offer not only sites of residence for blood cells but also indispensable signals directing HSPC homing, self-renewal, and multilineage differentiation. Deep insight into the structure and function of the BM vasculature niche and its participation in hematopoiesis is necessary to develop advanced strategies for the reconstitution of hematopoiesis.

The association between serum CD4 T lymphocyte counts and surgical outcomes in HIV/AIDS patients in Guangxi, China: a retrospective cohort study.

BACKGROUND: HIV/AIDS is a chronic disease leading to complications in infected individuals that often require surgical intervention. These patients' serum CD4 T lymphocyte (CD4) counts represent one of the most important indicators of their ability to tolerate surgical treatment. Previous studies have demonstrated that CD4 cell count (CD4-CC) < 200 cells/µl may increase the risk of surgical complications in these patients, limiting their ability to undergo surgery, which may negatively affect their quality of life. Further investigation into the surgical outcomes of patients with CD4-CC < 200 cells/µl should provide guidance in making appropriate clinical decisions for the optimal healthcare of this patient demographic. METHODS: All enrolled patients were selected from 14 prefecture-level general hospitals in Guangxi, China, and were referred to AIDS outpost hospitals for inpatient surgical therapy. A total cohort of 168 adult patients was retrospectively analyzed. Multifactorial and stratified analyses were performed to evaluate the in surgical outcome differences for patients with CD4-CC < 200 cells/µl (N = 43), using those with CD4-CC ≥ 200 cells/µl (N = 125) as controls. RESULTS: Poor incisional healing was used as the primary outcome indicator, and postoperative complications were used as the secondary outcome indicator. In the patient group with CD4-CC < 200 cells/µl, the risk of surgical complications was significantly increased (OR 2.379; 95% CI [1.049-5.394]) after adjustment. Adjusted stratified analysis of the CD4-CC < 200 cells/µl group revealed that individuals over 60 years (OR 27.504; 95% CI [2.297-329.317]) with erythrocyte counts below 4.00/ml for males or 3.50/ml for females (OR 3.353; 95% CI [1.079-10.419]) had a significantly higher risk of postoperative complications; this finding was statistically different from the control (CD4 ≥ 200 cells/µl) group. However, there was no significant difference between the two groups regarding the risk of poorly healed incision outcomes. CONCLUSIONS: Preliminary findings suggest that a serum CD4-CC < 200 cells/µl is not a definitive contraindication for surgical therapy and that baseline and surgical characteristics may help predict surgical outcomes in these patients. Further studies are needed to confirm these findings.

Synthetic phenolic antioxidants: Metabolism, hazards and mechanism of action.

Synthetic phenolic antioxidants can interact with peroxides produced by food. This paper reviews correlation between BHA, BHT and TBHQ metabolism and harms they cause and provides a theoretical basis for rational use of BHA, BHT and TBHQ in food, and also put some attention on the transformation and metabolic products of PG. We introduce BHA, BHT, TBHQ, PG and their possible metabolic pathways, and discuss possible harms and their specific mechanisms responsible. Excessive addition or incorrect use of synthetic phenolic antioxidants results in carcinogenicity, cytotoxicity, oxidative stress induction and endocrine disrupting effects, which warrant attention. BHA carcinogenicity is related to production of metabolites TBHQ and TQ, and cytotoxic effect of BHA is the main cause of apoptosis induction. BHT carcinogenicity depends on DNA damage degree, and tumour promotion is mainly related to production of quinone methylation metabolites. TBHQ carcinogenicity is related to induction of metabolite TQ and enzyme CYP1A1.

Epigenetic upregulation of galanin-like peptide mediates deoxynivalenol induced-growth inhibition in pituitary cells.

Deoxynivalenol (DON) is an unavoidable contaminant in human food, animal feeds, and agricultural products. Growth retardation in children caused by extensive DON pollution has become a global problem that cannot be ignored. Previous studies have shown that DON causes stunting in children through intestinal dysfunction, insulin-like growth factor-1 (IGF-1) axis disorder and peptide YY (PYY). Galanin-like peptide (GALP) is an important growth regulator, but its role in DON-induced growth retardation is unclear. In this study, we report the important role of GALP during DON-induced growth inhibition in the rat pituitary tumour cell line GH3. DON was found to increase the expression of GALP through hypomethylationin the promoter region of the GALP gene and upregulate the expression of proinflammatory factors, while downregulate the expression of growth hormone (GH). Furthermore, GALP overexpression promoted proinflammatory cytokines, including TNF-α, IL-1ß, IL-11 and IL-6, and further reduced cell viability and cell proliferation, while the inhibitory effect of GALP was the opposite. The expression of GALP and insulin like growth factor binding protein acid labile subunit (IGFALS) showed the opposite trend, which was the potential reason for the regulation of cell proliferation by GALP. In addition, GALP has anti-apoptotic effects, which could not eliminate the inflammatory damage of cells, thus aggravating cell growth inhibition. The present findings provide new mechanistic insights into the toxicity of DON-induced growth retardation and suggest a therapeutic potential of GALP in DON-related diseases.

Human adipose tissue- and umbilical cord-derived stem cells: which is a better alternative to treat spinal cord injury?

Multiple types of stem cells have been proposed for the treatment of spinal cord injury, but their comparative information remains elusive. In this study, a rat model of T10 contusion spinal cord injury was established by the impactor method. Human umbilical cord-derived mesenchymal stem cells (UCMSCs) or human adipose tissue-derived mesenchymal stem cells (ADMSCs) (2.5 µL/injection site, 1 × 105 cells/µL) was injected on rostral and caudal of the injury segment on the ninth day after injury. Rats injected with mesenchymal stem cell culture medium were used as controls. Our results show that although transplanted UCMSCs and ADMSCs failed to differentiate into neurons or glial cells in vivo, both significantly improved motor and sensory function. After spinal cord injury, UCMSCs and ADMSCs similarly promoted spinal neuron survival and axonal regeneration, decreased glial scar and lesion cavity formation, and reduced numbers of active macrophages. Bio-Plex analysis of spinal samples showed a specific increase of interleukin-10 and decrease of tumor necrosis factor α in the ADMSC group, as well as a downregulation of macrophage inflammatory protein 3α in both UCMSC and ADMSC groups at 3 days after cell transplantation. Upregulation of interleukin-10 and interleukin-13 was observed in both UCMSC and ADMSC groups at 7 days after cell transplantation. Isobaric tagging for relative and absolute quantitation proteomics analyses showed that UCMSCs and ADMSCs induced changes of multiple genes related to axonal regeneration, neurotrophy, and cell apoptosis in common and specific manners. In conclusion, UCMSC and ADMSC transplants yielded quite similar contributions to motor and sensory recovery after spinal cord injury via anti-inflammation and improved axonal growth. However, there were some differences in cytokine and gene expression induced by these two types of transplanted cells. Animal experiments were approved by the Laboratory Animal Ethics Committee at Jinan University (approval No. 20180228026) on February 28, 2018, and the application of human stem cells was approved by the Medical Ethics Committee of Medical College of Jinan University of China (approval No. 2016041303) on April 13, 2016.

Transplantation of human urine-derived neural progenitor cells after spinal cord injury in rats.

Spinal cord injury (SCI) is a worldwide problem and transplantation of neural progenitor cells (NPCs) represents a promising treatment strategy. Urine derived induced pluripotent stem cells (UiPSCs) which enable the generation of patient-specific NPCs, provide an invaluable source of autologous cells for future therapeutic applications after SCI. However, the fate and potential contribution of transplanted human UiPSCs-derived NPCs (UiPSC-NPCs) into injured spinal cords remain largely unknown. In this study, using a rat contusive SCI model, we evaluated the survival, migration and differentiation of UiPSC-NPCs after transplantation at subacute phase. Transplanted cells survived and migrated from the site of grafting towards the lesion epicenter. More than 25 % cells survived over 4 weeks post transplantation, with a few of them differentiated into neurons and astrocytes. Cytokine and chemokine levels within the injured spinal cord tissues were measured using multiplex immunoassays to evaluate the immune response. Pro-inflammatory factors and chemokines were significantly decreased at 3 days after UiPSC-NPCs transplantation. At 7 days post transplantation, a lower level of pro-inflammatory factor IFN-γ and a higher level of pro-inflammatory IL-2 were found in UiPSC-NPCs group than in the control. Transplantation of UiPSC-NPCs showed little effect on microglia activation at the lesion epicenter. However, the number of microglia cells at 4 mm rostral to the injury site was significantly decreased. The size of lesion cavity was reduced after transplantation of UiPSC-NPCs. In conclusions, the UiPSC-NPCs transplanted at the subacute phase of SCI showed a beneficial effect on tissue repairing.

A novel strategy for the diagnosis, prognosis, treatment, and chemoresistance of hepatocellular carcinoma: DNA methylation.

The cancer mortality rate of hepatocellular carcinoma (HCC) is the second highest in the world and the therapeutic options are limited. The incidence of this deadly cancer is rising at an alarming rate because of the high degree of resistance to chemo- and radiotherapy, lack of proper, and adequate vaccination to hepatitis B, and lack of consciousness and knowledge about the disease itself and the lifestyle of the people. DNA methylation and DNA methylation-induced epigenetic alterations, due to their potential reversibility, open the access to develop novel biomarkers and therapeutics for HCC. The contribution to these epigenetic changes in HCC development still has not been thoroughly summarized. Thus, it is necessary to better understand the new molecular targets of HCC epigenetics in HCC diagnosis, prevention, and treatment. This review elaborates on recent key findings regarding molecular biomarkers for HCC early diagnosis, prognosis, and treatment. Currently emerging epigenetic drugs for the treatment of HCC are summarized. In addition, combining epigenetic drugs with nonepigenetic drugs for HCC treatment is also mentioned. The molecular mechanisms of DNA methylation-mediated HCC resistance are reviewed, providing some insights into the difficulty of treating liver cancer and anticancer drug development.

DNA methylation and RASSF4 expression are involved in T-2 toxin-induced hepatotoxicity.

T-2 toxin is a secondary metabolite produced by Fusarium species and commonly contaminates food and animal feed. T-2 toxin can induce hepatotoxicity through apoptosis and oxidative stress; however, the underlying mechanism is not clear. Recent studies indicated that RASSF4, a member of the RASSF family, participates in cell apoptosis and some cancers due to its inactivation via DNA hypermethylation. However, its role in T-2 toxin-induced liver toxicity is poorly understood. Therefore, in this study, female Wistar rats were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at 1, 3 and 7 days post-exposure. A normal rat liver cell line (BRL) was exposed to different concentrations of T-2 toxin (10, 20, 40 nM) for 4, 8, 12 h, respectively. Histopathological analysis revealed with apoptosis in some liver cells and clear proliferation under T-2 toxin exposure. Expression analysis by immunohistochemical assays, quantitative real-time PCR (qPCR) and western blot demonstrated that T-2 toxin activated PI3K-Akt/Caspase/NF-κB signaling pathways. Additionally, DNA methylation assays revealed that the expression of RASSF4 was silenced by promoter hypermethylation after exposure to T-2 toxin for 1 and 3 days as compared to the control group. Moreover, joint treatment of 5-Aza-2'-deoxycytidine (DAC) (5 µM) and T-2 toxin (40 nM) increased expression of RASSF4 and PI3K-Akt/caspase/NF-κB signaling pathways-related genes, inducing cell apoptosis. These findings for the first time demonstrated that DNA methylation regulated the RASSF4 expression under T-2 toxin, along with the activation of its downstream pathways, resulting in apoptosis.

Ochratoxin A: Toxicity, oxidative stress and metabolism.

Ochratoxin A (OTA) is a widespread mycotoxin commonly found as a corn contaminant. It has been shown to be nephrotoxic, hepatotoxic, teratogenic and immunotoxic to several species of animals and to cause kidney and liver tumors in mice and rats. The focus of this article is primarily intended to summarize the progress in research associated with oxidative stress as a plausible mechanism for OTA-induced toxicity as well as its metabolism. The present review shows that studies have been carried out for decades to elucidate the production of reactive oxygen species (ROS) and oxidative stress as a result of OTA treatment and have correlated them with various types of OTA toxicity, indicating that oxidative stress plays critical roles in the toxicity of OTA. The major metabolic pathways of OTA are hydrolysis and a small percentage of absorbed OTA is hydroxylated. CYP450, carboxypeptidase A, trypsin, α-chymotrypsin and cathepsin have been shown to be able to degrade OTA. Most metabolites of OTA are less toxic than OTA except OP-OTA. Further understanding of the role of oxidative stress in OTA-induced toxicity will throw new light on the use of antioxidants, scavengers of ROS, as well as on the blind spots of the metabolism and metabolic enzymes of OTA. The present review might contribute to reveal the oxidative stress-induced toxicity of OTA and help to protect against its oxidative damage.

Nitric oxide (NO)-mediated mitochondrial damage plays a critical role in T-2 toxin-induced apoptosis and growth hormone deficiency in rat anterior pituitary GH3 cells.

T-2 toxin, a major compound of trichothecenes, induces cell apoptosis and growth hormone (GH) deficiency and causes considerable growth retardation in animals and human cells. However, the mechanism underlying its growth suppression still remains unclear. Recent studies have suggested that ROS induced cell apoptosis and animal feed intake reduction, but there are limited reports on the role of RNS in T-2 toxin-mediated mitochondrial damage, cell apoptosis and growth retardation. Herein, T-2 toxin-induced GH3 cell damage and apoptosis were tested by MTT assay, LDH leakage and flow cytometry, respectively. Intracellular NO and antioxidant enzyme activity, ΔΨm, morphometric changes of mitochondria, the caspase pathway, and inflammatory factors were investigated. Free radical scavengers NAC, SOD and NO scavenger haemoglobin were used to explore the role of oxidative stress and the relationship between NO production and caspase pathway. The results clearly revealed that T-2 toxin caused significant increases in NO generation, cell apoptosis, GH deficiency, increased iNOS activity, upregulation of inflammatory factors and caspase pathway, decreases in ΔΨm and morphosis damage. These data suggest that mitochondria are a primary target of T-2 toxin-induced NO, and NO is a key mediator of T-2 toxin-induced cell apoptosis and GH deficiency via the mitochondria-dependent pathway in cells.

Role of thymic stromal lymphopoietin in the pathogenesis of nasal polyposis.

INTRODUCTION: Polyposis is an end form of chronic mucosal inflammation in a number of disorders and has an important impact on patient's life quality. Thymic stromal lymphopoietin (TSLP) is involved in many inflammatory processes such as asthma and allergic rhinitis (AR). The aim of this study is to elucidate the role of TSLP in the pathogenesis of polyposis. METHODS: Ninety-four patients with nasal polyposis (NP) and/or allergic rhinitis (AR) were treated with inferior turbinectomy and polyp resection. Levels of TSLP in the nasal epithelial layer were measured; expression of TSLP receptor and OX40 ligand (OX40L) was assessed in isolated nasal mucosal dendritic cells (DC); tumor necrosis factor (TNF), interleukin (IL)-4 and interferon (IFN)-γ expressions were determined in isolated nasal mucosal CD4(+) T cells. RESULTS: The levels of TSLP in nasal epithelial layer were higher in the NP group than in the non-NP group. Higher expression of TSLP receptor and OX40L were detected in DCs of NP nasal mucosa. TNF-α(+) IL-4(+)CD4(+) T cells were detected in NP/AR nasal mucosa; TNF(+) IFN-γ(+) CD4(+) T cells were identified in NP/non-AR nasal mucosa. TSLP-primed DCs drove naive CD4(+) T cells to become TNF(+) IL-4(+) CD4(+) T cells, whereas TSLP/lipopolysaccharide-primed DCs induced naive CD4(+) T cells to become TNF(+) IFN-γ(+) T cells. CONCLUSIONS: The data indicate that TSLP is involved in the pathogenesis of polyposis.