Juan Zhuang

Troxerutin inhibits 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-induced hepatocyte apoptosis by restoring proteasome function.

Proteasome dysfunction has been associated with the pathogeneses of a variety of diseases and with the neurotoxicities of environmental chemicals; however, whether proteasome dysfunction plays a role in the cellular toxicity of polybrominated diphenyl ethers (PBDEs) has not been investigated to date. Emerging evidence suggests that antioxidants exhibit evident beneficial effects on the cellular toxicity associated with PBDEs. In the present study, we investigated whether troxerutin attenuates BDE-47-induced hepatocyte apoptosis by restoring proteasome function and explored the mechanisms underlying this effect. Our results revealed that proteasome dysfunction was involved in the BDE-47-induced hepatocyte apoptosis in the mouse liver. Furthermore, our results revealed that troxerutin effectively inhibited hepatocyte apoptosis by restoring oxidative stress-mediated proteasome dysfunction in BDE-47-treated mice. Consequently, troxerutin markedly suppressed endoplasmic reticulum (ER) stress in the livers of the BDE-47-treated mice. The inhibitory effects of troxerutin on ER stress and apoptotic pathways were markedly blunted by treatment with epoxomicin (a selective inhibitor of proteasome). Ultimately, troxerutin dramatically blocked TRAF2-ASK1-JNK signaling and CHOP-mediated apoptosis signaling in the BDE-47-treated mouse livers. This study provides novel mechanistic insights into the toxicity of BDE-47 and indicates that troxerutin might be a candidate for the prevention of and therapy for BDE-47-induced hepatotoxicity.

Relationship Between Neonatal Vitamin D at Birth and Risk of Autism Spectrum Disorders: the NBSIB Study

Previous studies suggested that lower vitamin D might be a risk factor for autism spectrum disorders (ASDs). The aim of this study was to estimate the prevalence of ASDs in 3‐year‐old Chinese children and to examine the association between neonatal vitamin D status and risk of ASDs. We conducted a study of live births who had taken part in expanded newborn screening (NBS), with outpatient follow‐up when the children 3‐year old. The children were confirmed for ASDs in outpatient by the Autism Diagnostic Interview‐Revised and Diagnostic and Statistical Manual of Mental Disorders (DSM)‐5 criteria. Intellectual disability (ID) status was defined by the intelligence quotient (IQ < 80) for all the participants. The study design included a 1:4 case to control design. The concentration of 25‐hydroxyvitamin D3 [25(OH)D3] in children with ASD and controls were assessed from neonatal dried blood samples. A total of 310 children were diagnosed as having ASDs; thus, the prevalence was 1.11% (95% CI, 0.99% to 1.23%). The concentration of 25(OH)D3 in 310 ASD and 1240 controls were assessed. The median 25(OH)D3 level was significantly lower in children with ASD as compared to controls (p < 0.0001). Compared with the fourth quartiles, the relative risk (RR) of ASDs was significantly increased for neonates in each of the three lower quartiles of the distribution of 25(OH)D3, and increased risk of ASDs by 260% (RR for lowest quartile: 3.6; 95% CI, 1.8 to 7.2; p < 0.001), 150% (RR for second quartile: 2.5; 95% CI, 1.4 to 3.5; p = 0.024), and 90% (RR for third quartile: 1.9; 95% CI, 1.1 to 3.3; p = 0.08), respectively. Furthermore, the nonlinear nature of the ID‐risk relationship was more prominent when the data were assessed in deciles. This model predicted the lowest relative risk of ID in the 72rd percentile (corresponding to 48.1 nmol/L of 25(OH)D3). Neonatal vitamin D status was significantly associated with the risk of ASDs and intellectual disability. The nature of those relationships was nonlinear.

The Inhibitory Effects of Purple Sweet Potato Color on Hepatic Inflammation Is Associated with Restoration of NAD+ Levels and Attenuation of NLRP3 Inflammasome Activation in High-Fat-Diet-Treated Mice

Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, exhibits beneficial effects on metabolic syndrome. Sustained inflammation plays a crucial role in the pathogenesis of metabolic syndrome. Here we explored the effects of PSPC on high-fat diet (HFD)-induced hepatic inflammation and the mechanisms underlying these effects. Mice were divided into four groups: Control group, HFD group, HFD + PSPC group, and PSPC group. PSPC was administered by daily oral gavage at doses of 700 mg/kg/day for 20 weeks. Nicotinamide riboside (NR) was used to increase NAD+ levels. Our results showed that PSPC effectively ameliorated obesity and liver injuries in HFD-fed mice. Moreover, PSPC notably blocked hepatic oxidative stress in HFD-treated mice. Furthermore, PSPC dramatically restored NAD+ level to abate endoplasmic reticulum stress (ER stress) in HFD-treated mouse livers, which was confirmed by NR treatment. Consequently, PSPC remarkably suppressed the nuclear factor-κB (NF-κB) p65 nuclear translocation and nucleotide oligomerization domain protein1/2 (NOD1/2) signaling in HFD-treated mouse livers. Thereby, PSPC markedly diminished the NLR family, pyrin domain containing 3 (NLRP3) inflammasome activation, ultimately lowering the expressions of inflammation-related genes in HFD-treated mouse livers. In summary, PSPC protected against HFD-induced hepatic inflammation by boosting NAD+ level to inhibit NLRP3 inflammasome activation.

Effects of long noncoding RNA SPRY4-IT1-mediated EZH2 on the invasion and migration of lung adenocarcinoma

We aim to investigate the interaction between the EZH2 and the long noncoding RNA (lncRNA) SPRY4‐IT1. We also explore their respective effects on human lung adenocarcinoma (LA) cell invasion and migration. Both LA and adjacent normal tissues were obtained from 256 LA patients. SPTY4‐IT expression and EZH2 mRNA expressions in tissues and cells were detected by reverse transcription quantitative polymerase chain reaction (RT‐qPCR). The siRNAs against SPRY4‐IT1 and EZH2 were co‐transfected into A549 and H1975 cells. The interaction between SPRY4‐IT1 and EZH2 was determined using a RNA pull‐down assay and a RNA immunoprecipitation (RIP) assay. A Transwell assay and scratch assay were used to evaluate the cell migration and invasion abilities. The expressions of E‐cadherin and Vimentin in the epithelial‐mesenchymal transition (EMT) and EZH2 protein expression were detected through western blotting. SPRY4‐IT1 expression was observed to be significantly lower, while the expression of EZH2 was higher in the LA tissues than in the adjacent normal tissues. Compared with the HBE cell line, expressions of SPRY4‐IT1 in each human LA cell line had decreased, with the lowest observed reduction in the A549 cell line, while EZH2 mRNA and protein expression increased in each human LA cell lines. After SPRY4‐IT1‐siRNA was transfected into A549 and H1975 cells, invasion and migration abilities were enhanced, in addition to a reduction in the expression of E‐cadherin, while expressions of Vimentin exhibited an increased rate. Consequently, we find that EZH2 promotes LA cell invasion and metastasis by inhibiting SPRY4‐IT1 expression.

LncRNA LINC00880 promotes cell proliferation, migration, and invasion while inhibiting apoptosis by targeting CACNG5 through the MAPK signaling pathway in spinal cord ependymoma

The present study was to investigate the effect of lncRNA LINC00880 targeting CACNG5 on cell proliferation, migration, invasion, and apoptosis in spinal cord ependymoma (SCE) through the MAPK signaling pathway. GEO database was used to download gene expression data related with SCE (GSE50161 and GSE66354) and annotation file. LncRNA with differential expression was predicted by Multi Experiment Matrix website (MEM). The target gene was analyzed by KEGG pathway enrichment analysis. SCE tissues and adjacent tissues were collected. The positive expression of CACNG5 protein was tested by immunohistochemistry. Expression of LINC00880, CACNG5, and MAPK signaling pathway‐related proteins was measured with qRT‐PCR and Western blotting. Cell proliferation, migration, invasion, cycle, and apoptosis were detected using MTT, Transwell assay, Scratch test, and Flow cytometry. SCE tissues showed increased LINC00880 expression. CACNG5 was a target gene of LINC00880 and correlated with MAPK signaling pathway. Compared with adjacent tissues, SCE tissues showed lower positive expression of CACNG5. Compared with the blank group, LINC00880 expression was higher in the LINC00880 vector and LINC00880 vector + CACNG5 vector groups, and lower in the si‐LINC00880 and si‐LINC00880 + si‐CACNG5 groups; in the LINC00880 vector and si‐CACNG5 groups, expression of survivin, p38MAPK, ERK1/2, JNK1/2/3 increased and CACNG5 and Bax expression reduced, the proliferation, invasion and migration of tumor cells increased, and apoptosis rate decreased. Opposite results were found in the si‐LINC00880 and CACNG5 vector groups. The findings indicate that lncRNA LINC00880 targeting CACNG5 inhibits cell apoptosis and promotes proliferation, migration, and invasion in SCE through the MAPK signaling pathway.

Troxerutin Protects Kidney Tissue against BDE-47-Induced Inflammatory Damage through CXCR4-TXNIP/NLRP3 Signaling

2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) induces oxidative stress in kidney cells, but the underlying mechanism remains poorly understood. Troxerutin, a natural flavonoid, has potential antioxidant and anti-inflammatory efficacy. In this study, we assessed the effect of troxerutin on kidney damage caused by BDE-47 and investigated the underlying mechanism. The results showed troxerutin reduced reactive oxygen species (ROS) level and urine albumin-to-creatinine ratio (ACR), decreased the activities of inflammatory factors including cyclooxygenase-2 (COX-2), induced nitric oxide synthase (iNOS) and nuclear factor kappa B (NF-κB) in the kidney tissues of BDE-47-treated mice. Furthermore, troxerutin significantly weakened the expression of kidney NLRP3 inflammasome containing NLRP3, ASC, and caspase-1, contributing to the decline of IL-1β. Additionally, troxerutin inhibited the increased protein level of stromal-derived factor-1(SDF-1), C-X-C chemokine ligand 12 receptor 4 (CXCR4), and thioredoxin interaction protein (TXNIP) caused by BDE-47. Specifically, the immunoprecipitation assay indicated that there was a direct interaction between CXCR4 and TXNIP. CXCR4 siRNA and TXNIP siRNA also decreased the inflammatory damage, which was similar to the action of troxerutin. Our data demonstrated that troxerutin regulated the inflammatory lesions via CXCR4-TXNIP/NLRP3 inflammasome in the kidney of mice induced by BDE-47.

Repression of microRNA-382 inhibits glomerular mesangial cell proliferation and extracellular matrix accumulation via FoxO1 in mice with diabetic nephropathy

Diabetic nephropathy (DN) is a nerve damaging disorder, characterized by glomerular mesangial cell expansion and accumulation of extracellular matrix (ECM) proteins. In this study, we aimed to investigate mesangial cell proliferation and ECM accumulation when promoting or suppressing endogenous miR‐382 in glomerular mesangial cells of DN.

Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

2,2,4,4-Tetrabromodiphenyl ether (BDE-47), one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS) and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

Attenuation of hepatic steatosis by purple sweet potato color is associated with blocking Src/ERK/C/EBPβ signalling in high-fat-diet-treated mice

Our previous work showed that purple sweet potato colour (PSPC), a class of naturally occurring anthocyanins, effectively improved hepatic glucose metabolic dysfunction in high-fat-diet (HFD)-treated mice. This study investigated the effects of PSPC on HFD-induced hepatic steatosis and the signalling events associated with these effects. Mice were divided into 4 groups: control group, HFD group, HFD+PSPC group, and PSPC group. PSPC was administered daily for 20 weeks at oral doses of 700 mg/(kg·day)-1). Our results showed that PSPC significantly improved obesity and related metabolic parameters, as well as liver injury in HFD-treated mice. Moreover, PSPC dramatically attenuated hepatic steatosis in HFD-treated mice. PSPC markedly prevented oxidative stress-mediated Src activation in HFD-treated mouse livers. Furthermore, PSPC feeding remarkably suppressed mitogen-activated protein kinase kinase/extracellular-signal-regulated kinase (MEK/ERK) signalling and consequent CCAAT/enhancer binding protein β (C/EBPβ) activation and restored AMPK activation in HFD-treated mouse livers, which was confirmed by U0126 treatment. Ultimately, PSPC feeding dramatically reduced protein expression of FAS and CD36 and the activation of ACC, and increased the protein expression of CPT1A in the livers of HFD-treated mice, indicating decreased lipogenesis and fatty acid uptake and enhanced fatty acid oxidation. In conclusion, PSPC exhibited beneficial effects on hepatic steatosis, which were associated with blocking Src and C/EBPβ activation.

Adeno-associated virus vector-mediated expression of DJ-1 attenuates learning and memory deficits in 2, 2´, 4, 4´-tetrabromodiphenyl ether (BDE-47)-treated mice

Evidence indicates that oxidative stress is the central pathological feature of 2, 2´, 4, 4´-tetrabromodiphenyl ether (BDE-47)-induced neurotoxicity. Protein kinase C delta (PKCδ), an oxidative stress-sensitive kinase, can be proteolytically cleaved to yield a catalytically active fragment (PKCδ-CF) that is involved in various neurodegenerative disorders. Here, we showed that BDE-47 treatment increased ROS, malondialdehyde, and protein carbonyl levels in the mouse hippocampus. In turn, excessive ROS induced caspase-3-dependent PKCδ activation and stimulated NF-κB p65 nuclear translocation, resulting in inflammation in the mouse hippocampus. These changes caused learning and memory deficits in BDE-47-treated mice. Treatment with Z-DEVD-fmk, a caspase-3 inhibitor, or N-acetyl-L-cysteine, an antioxidant, blocked PKCδ activation and subsequently inhibited inflammation, thereby improving learning and memory deficits in BDE-47-treated mice. Our data further showed that activation of ROS-PKCδ signaling was associated with DJ-1 downregulation, which exerted neuroprotective effects against oxidative stress induced by different neurotoxic agents. Adeno-associated viral vector-mediated DJ-1 overexpression in the hippocampus effectively inhibited excessive ROS production, suppressed caspase-3-dependent PKCδ cleavage, blunted inflammation and ultimately reversed learning and memory deficits in BDE-47-treated mice. Taken together, our results demonstrate that DJ-1 plays a pivotal role in BDE-47-induced neurotoxic effects and learning and memory deficits.