miR-199a-3p mediates bone cancer pain through upregulation of dnmt3a expression in spinal dorsal horn neurons.

Due to its complex pathological mechanisms, bone cancer pain (BCP) has become an increasingly challenging clinical issue, there is an urgent need to identify the underlying mechanisms of BCP. In our present study, we found that decreased expression of miR-199a-3p in spinal dorsal horn (SDH) neurons contributed to BCP hypersensitivity. Intrathecal administration of miR-199a-3p agomir alleviated the initiation of tumor inoculation induced pain hypersensitivity and suppressed the expression of DNMT3A. Subsequently, luciferase assays confirmed direct binding between miR-199a-3p and Dnmt3a mRNA. AAV-DNMT3A-shRNA microinjection relieved mechanical hyperalgesia and upregulated the expression of Nrf2 levels in BCP. In naïve rats, Overexpression of DNMT3A yielded the opposite effects. Finally, increase of DNMT3A by lentiviral vector abolished miR-199a-3p-mediated alleviation hypersensitivity effects on BCP progression. Taken these together, our findings highlighted a novel contribution of miR-199a-3p to BCP and provided a fresh outlook on potential mechanism research for BCP.

Protection of Male Rat Offspring against Hypertension Programmed by Prenatal Dexamethasone Administration and Postnatal High-Fat Diet with the Nrf2 Activator Dimethyl Fumarate during Pregnancy.

Hypertension can originate from early-life exposure to oxidative stress. As reported, dimethyl fumarate (DMF) activates nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and protects against oxidative stress damage. We examined whether maternal DMF therapy protects adult offspring against hypertension programmed by prenatal dexamethasone (DEX) and postnatal high-fat (HF) diet exposure. We examined male Sprague Dawley rat offspring at 4 months of age from five groups (n = 11-13/group): control, DEX (0.1mg/kg i.p. from gestational day 16 to 22), HF (D12331 diet from weaning to 16 weeks of age), DEX+HF, and DEX+HF+DMF (50mg/kg/day via gastric gavage for 3 weeks during pregnancy). Maternal DMF therapy prevented male offspring against hypertension programmed by combined DEX and HF exposures. The protective effects of maternal DMF include reduced oxidative stress, decreased plasma asymmetric dimethylarginine (ADMA) levels, downregulated the renin-angiotensin system (i.e. Ren, Agt, Ace, and Agtr1a), increased renal protein levels of certain nutrient-sensing signals, and promoted autophagy. In conclusion, maternal Nrf2 activation by DMF protects male adult offspring against hypertension programmed by combined DEX and HF exposures. Our results cast a new light on the therapeutic potential of targeting Nrf2 signaling pathway as reprogramming strategies to prevent programmed hypertension in children exposed to antenatal corticosteroids and postnatally excessive consumption of fat.

Exendin-4, a glucagon-like peptide-1 receptor agonist, reduces hepatic steatosis and endoplasmic reticulum stress by inducing nuclear factor erythroid-derived 2-related factor 2 nuclear translocation.

Activation of endoplasmic reticulum (ER) stress is involved in the development of nonalcoholic fatty liver disease. Glucagon-like peptide-1 (GLP-1) has been reported to reduce hepatic steatosis, but the underlying mechanism has not been fully elucidated. Here, we investigated whether exendin-4 (EX-4), a GLP-1 receptor analogue, improves hepatic steatosis through ER stress reduction. Furthermore, we explored which ER stress pathway is involved in this process, with a focus on the protein kinase RNA-like ER kinase (PERK)-nuclear factor erythroid-derived 2-related factor 2 (Nrf2) pathway. EX-4 treatment reduced hepatic lipid accumulation by suppressing the expression of lipogenic genes and restoring the expression of ß-oxidation genes in palmitate-treated HepG2 cells and high fat diet (HFD)-fed mice. In addition, EX-4 treatment suppressed hepatic ER stress activation in HFD-fed mice and tunicamycin-treated mice. In particular, EX-4 treatment restored HFD- and tunicamycin-induced Nrf2 nuclear translocation to control levels. Inhibition of Nrf2 by siRNA enhanced phosphorylation of PERK and eukaryotic translation initiation factor 2α (eIF2α), as well as other substrates of the PERK pathway. Nrf2 knockdown also inhibited the protective effects of EX-4 against lipid accumulation, ER stress activation, and cell death in palmitate-treated HepG2 cells. EX-4 treatment prevents hepatic steatosis and improves cell survival by regulating hepatic lipid metabolism and reducing ER stress activation, and Nrf2 plays an essential role in the protective effect of GLP-1 on hepatic steatosis.

Genistein protects benzotriazole ultraviolet stabilizer UV-234-induced hepatotoxicity by modulating ROS/Nrf2 and NF-κB signaling in yellow catfish (Pelteobagrus fulvidraco).

Benzotriazole ultraviolet stabilizers (BUVSs) are a group of anthropogenic chemicals widely used in commodities and industrial products, posing a potential threat to aquatic organisms. However, limited data are available on the toxicity effects of BUVSs in the liver, and no data are available on effective therapeutic strategies. In this study, we exployed aimed to explore the hepatotoxicity of 2-(benzotriazol-2-yl)-4,6-bis(2-phenylpropan-2-yl)phenol (UV-234) and reveal the preventive function of Genistein. At first, yellow catfish (Pelteobagrus fulvidraco) exposed to UV-234 (10 µg/L) showed up-regulated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) and hepatic reactive oxygen species (ROS) overproduction, along with significantly reduced activities of antioxidants enzymes and nuclear factor erythroid-derived 2-related factor 2 (Nrf2) basal levels. In contrast, 100 mg/kg diet of Genistein improve the hepatic antioxidative capability of fish via activating Nrf2 pathway. Furthermore, we confirmed that UV-234 exposure could induce nuclear factor-κB (NF-κB)-driven inflammatory response, as evidenced by the hepatic inflammatory cells infiltration, lower levels of plasma complement C3 (C3) and complement C4 (C4) as well as higher mRNA levels of NF-κB and inflammatory cytokines. Conversely, feeding UV-234-exposed fish on Genistein-supplemented diets attenuated above adverse effects. Meanwhile, we confirmed that Genistein supplement protected liver apoptosis induced by UV-234 via suppressing up-regulated expression levels of pro-apoptotic genes (Bax, caspase3). In summary, our findings revealed that Genistein positively regulates the Nrf2-mediated antioxidant defenses and reduce NF-κB-driven inflammatory response, thus indirectly inhibiting hepatic damage induced by UV-234 in yellow catfish (Pelteobagrus fulvidraco).

Moringa oleifera Lam. seed extract protects kidney function in rats with diabetic nephropathy by increasing GSK-3ß activity and activating the Nrf2/HO-1 pathway.

BACKGROUND: Moringa oleifera Lam. (M. oleifera) seeds are widely used in traditional folk medicine and as nutritional supplements in the Middle East, Africa, and other regions. Published research showed that M. oleifera seeds (MOS) have pharmacological activities such as blood glucose-lowering, anti-inflammatory, and antitumor effects. However, experimental evidence on the use of MOS to treat diabetic nephropathy and its underlying mechanisms were rarely reported. PURPOSE: To evaluate the therapeutic effects of MOS extract on the kidneys of high-fat diet (HFD)-fed rats with streptozotocin-induced diabetic nephropathy and reveal its underlying mechanisms. STUDY DESIGN: HFD-fed rats with streptozotocin-induced diabetic nephropathy and high-glucose induced Human Renal Mesangial Cells (HRMC) were used to explore the protective effect of MOS on diabetic nephropathy in vivo and in vitro. METHODS: HRMC were used to preliminarily evaluate the effect of MOS extract under high glucose conditions. For the in vivo study, rats were divided into the following 6 groups (n = 5): normal control group (NC), diabetic nephropathy model group (DN), high dose of MOS-treatment group (DN + MOS-H, 200 mg/kg/d); medium dose of MOS-treatment group (DN + MOS-M, 100 mg/kg/d); low dose of MOS-treatment group (DN + MOS-l, 50 mg/kg/d), and metformin-treatment group (DN + MET, 200 mg/kg/d). After 4 weeks of treatment, the damage caused by DN was assessed based on the related parameters of urine and blood. Periodic acid-Schiff (PAS) staining and hematoxylin and eosin (HE) staining were used to assess pathological tissue damage. Immunohistochemistry was used to detect nuclear factor erythroid-derived 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and phosphorylated-glycogen synthase kinase-3beta (P-GSK-3ß) levels, whereas western blotting was used to detect Nrf2, HO-1, nephrin, GSK-3ß, and p-GSK-3ß levels. RESULTS: MOS extract could inhibit the proliferation of HRMCs induced by high glucose levels. Compared with the rats in the DN group, MOS not only significantly reduced blood glucose levels and oxidative stress in the experimental rats but also improved their kidney function and reduced kidney tissue damage. Additionally, MOS extract increased GSK-3ß activity and the expression of Nrf2 and HO-1. CONCLUSIONS: This study showed that MOS could activate GSK-3ß and Nrf2/HO-1 pathways to exert antioxidant and anti-renal fibrosis activities, and delay the progression of diabetic nephropathy.

Oleoylethanolamide Reduces Hepatic Oxidative Stress and Endoplasmic Reticulum Stress in High-Fat Diet-Fed Rats.

Long-term high-fat diet (HFD) consumption can cause weight gain and obesity, two conditions often associated with hepatic non-alcoholic fatty liver and oxidative stress. Oleoylethanolamide (OEA), a lipid compound produced by the intestine from oleic acid, has been associated with different beneficial effects in diet-induced obesity and hepatic steatosis. However, the role of OEA on hepatic oxidative stress has not been fully elucidated. In this study, we used a model of diet-induced obesity to study the possible antioxidant effect of OEA in the liver. In this model rats with free access to an HFD for 77 days developed obesity, steatosis, and hepatic oxidative stress, as compared to rats consuming a low-fat diet for the same period. Several parameters associated with oxidative stress were then measured after two weeks of OEA administration to diet-induced obese rats. We showed that OEA reduced, compared to HFD-fed rats, obesity, steatosis, and the plasma level of triacylglycerols and transaminases. Moreover, OEA decreased the amount of malondialdehyde and carbonylated proteins and restored the activity of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, which decreased in the liver of HFD-fed rats. OEA had also an improving effect on parameters linked to endoplasmic reticulum stress, thus demonstrating a role in the homeostatic control of protein folding. Finally, we reported that OEA differently regulated the expression of two transcription factors involved in the control of lipid metabolism and antioxidant genes, namely nuclear factor erythroid-derived 2-related factor 1 (Nrf1) and Nrf2, thus suggesting, for the first time, new targets of the protective effect of OEA in the liver.

Tetrandrine mediates renal function and redox homeostasis in a streptozotocin-induced diabetic nephropathy rat model through Nrf2/HO-1 reactivation.

BACKGROUND: Diabetic nephropathy (DN) is the leading cause of morbidity and mortality in diabetic patients. Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid isolated from the roots of Stephania tetrandra, possesses anti-oxidative, anti-hypertensive, anti-inflammatory capacities. In this study, the maintenance role of Tet in DN was evaluated in streptozotocin (STZ)-induced diabetic rats. METHODS: In vitro study, rats were divided into five groups (n=10): the control group, the DN model group, the Tet-treatment group (5, 15, 30 mg/kg). DN damage was assessed by levels of blood glucose, serum creatinine (CRE), proteinuria, and urea nitrogen. ELISA assay was used to detecte tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and IL-10 levels. Kits were used to detecte contents of malondialdehyde (MDA), lactate dehydrogenase (LDH) and superoxide dismutase (SOD). Dichlorofluorescein (DCF) staining was used to detecte reactive oxygen species (ROS). HE staining assessed pathological damage. TUNEL staining assessed tissue apoptosis. Western Blot (WB) was used to detecte levels of Ki67, Survivin, Bax, Bcl-2, caspase-3, -9, c-Myc, nuclear factor erythroid-derived 2-related factor 2 (Nrf2), p-Nrf2, and heme oxygenase-1 (HO-1). RESULTS: Compared with the control group, STZ-induced significantly inhibited proliferation proteins' level, activated oxidative stress, aggravated tissue inflammation and promoted tissue apoptosis. STZ-induced further aggravated DN damage. Of note, these anomalies were restored by Tet pretreatment. Additionally, Tet upgraded the expression of p-Nrf2 and HO-1. CONCLUSIONS: These results indicated that Tet could significantly restrain diabetic process and renal damage. Tet is a potential therapeutic agent in DN treatment via the reactivation of the Nrf2/HO-1.

A novel role of the NRF2 transcription factor in the regulation of arsenite-mediated keratin 16 gene expression in human keratinocytes.

BACKGROUND: Inorganic sodium arsenite (iAs) is a ubiquitous environmental contaminant and is associated with an increased risk of skin hyperkeratosis and cancer. OBJECTIVES: We investigated the molecular mechanisms underlying the regulation of the keratin 16 (K16) gene by iAs in the human keratinocyte cell line HaCaT. METHODS: We performed reverse transcriptase polymerase chain reaction, luciferase assays, Western blots, and electrophoretic mobility shift assays to determine the transcriptional regulation of the K16 gene by iAs. We used gene overexpression approaches to elucidate the nuclear factor erythroid-derived 2 related factor 2 (NRF2) involved in the K16 induction. RESULTS: iAs induced the mRNA and protein expression of K16. We also found that the expression of K16 was transcriptionally induced by iAs through activator protein-1-like sites and an antioxidant response element (ARE) in its gene promoter region. Treatment with iAs also enhanced the production and translocation of the NRF2 transcription factor, an ARE-binding protein, into the nucleus without modification of its mRNA expression. In addition, iAs elongated the half-life of the NRF2 protein. When overexpressed in HaCaT cells, NRF2 was also directly involved in not only the up-regulation of the detoxification gene thioredoxin but also K16 gene expression. CONCLUSIONS: Our data clearly indicate that the K16 gene is a novel target of NRF2. Furthermore, our findings also suggest that NRF2 has opposing roles in the cell--in the activation of detoxification pathways and in promoting the development of skin disorders.

Preoperative short-term fasting protects liver injury in patients undergoing hepatectomy.

BACKGROUND: Our previous study demonstrated that preoperative short-term fasting attenuates mice hepatic ischemia/reperfusion injury (IRI), which greatly piqued our interest in verifying if fasting produces similar protective effects in patients undergoing hepatectomy. METHODS: Eighty patients with liver tumors were randomized into control (Ctrl, n=40, preoperative fasting for 6 h) or fasting group (Fasting, n=40, preoperative fasting for 24 h). Serum was collected at pre-operation (Pre-Op), post-operation 1 day (POD-1), post-operation 3 days (POD-3), and post-operation 7 days (POD-7). Liver tissue was removed from the resected specimen. RESULTS: Sixty-three patients were eventually enrolled, with 33 in Ctrl and 30 in Fasting group. Our data showed that 24 h fasting effectively attenuated elevated sALT and sAST levels after operation (P<0.05), but serum total bilirubin was significantly lower at only POD-3 (P<0.05); and serum albumin was not markedly different in either of the groups. Interestingly, 24 h fasting partially attenuates expression of pro-inflammatory cytokine (TNF-α) and improves oxidative stress (MDA and SOD). Our data further showed short-term fasting triggered Nrf2 signaling pathway. CONCLUSIONS: This study demonstrates preoperative short-term fasting effectively improves clinical outcomes and markedly attenuates inflammatory responses and oxidative stress in patients undergoing hepatectomy, and Nrf2 signaling pathway may play a key role in fasting against inflammatory responses and oxidant stress.