Targeting DNM1L/DRP1-FIS1 axis inhibits high-grade glioma progression by impeding mitochondrial respiratory cristae remodeling.

BACKGROUND: The dynamics of mitochondrial respiratory cristae (MRC) and its impact on oxidative phosphorylation (OXPHOS) play a crucial role in driving the progression of high-grade glioma (HGG). However, the underlying mechanism remains unclear. METHODS: In the present study, we employed machine learning-based transmission electron microscopy analysis of 7141 mitochondria from 54 resected glioma patients. Additionally, we conducted bioinformatics analysis and multiplex immunohistochemical (mIHC) staining of clinical glioma microarrays to identify key molecules involved in glioma. Subsequently, we modulated the expression levels of mitochondrial dynamic-1-like protein (DNM1L/DRP1), and its two receptors, mitochondrial fission protein 1 (FIS1) and mitochondrial fission factor (MFF), via lentiviral transfection to further investigate the central role of these molecules in the dynamics of glioblastoma (GBM) cells and glioma stem cells (GSCs). We then evaluated the potential impact of DNM1L/DRP1, FIS1, and MFF on the proliferation and progression of GBM cells and GSCs using a combination of CCK-8 assay, Transwell assay, Wound Healing assay, tumor spheroid formation assay and cell derived xenograft assay employing NOD/ShiLtJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt (NCG) mouse model. Subsequently, we validated the ability of the DNM1L/DRP1-FIS1 axis to remodel MRC structure through mitophagy by utilizing Seahorse XF analysis technology, mitochondrial function detection, MRC abundance detection and monitoring dynamic changes in mitophagy. RESULTS: Our findings revealed that compared to low-grade glioma (LGG), HGG exhibited more integrated MRC structures. Further research revealed that DNM1L/DRP1, FIS1, and MFF played pivotal roles in governing mitochondrial fission and remodeling MRC in HGG. The subsequent validation demonstrated that DNM1L/DRP1 exerts a positive regulatory effect on FIS1, whereas the interaction between MFF and FIS1 demonstrates a competitive inhibition relationship. The down-regulation of the DNM1L/DRP1-FIS1 axis significantly impaired mitophagy, thereby hindering the remodeling of MRC and inhibiting OXPHOS function in glioma, ultimately leading to the inhibition of its aggressive progression. In contrast, MFF exerts a contrasting effect on MRC integrity, OXPHOS activity, and glioma progression. CONCLUSIONS: This study highlights that the DNM1L/DRP1-FIS1 axis stabilizes MRC structures through mitophagy in HGG cells while driving their OXPHOS activity ultimately leading to robust disease progression. The inhibition of the DNM1L/DRP1-FIS1 axis hinders MRC remodeling and suppresses GBM progression. We propose that down-regulation of the DNM1L/DRP1-FIS1 axis could be a potential therapeutic strategy for treating HGG.

FUS Selectively Facilitates circRNAs Packing into Small Extracellular Vesicles within Hypoxia Neuron.

Small extracellular vesicles (sEVs) contain abundant circular RNAs (circRNAs) and are involved in cellular processes, particularly hypoxia. However, the process that packaging of circRNAs into neuronal sEVs under hypoxia is unclear. This study revealed the spatial mechanism of the Fused in Sarcoma protein (FUS) that facilitates the loading of functional circRNAs into sEVs in hypoxia neurons. It is found that FUS translocated from the nucleus to the cytoplasm and is more enriched in hypoxic neuronal sEVs than in normal sEVs. Cytoplasmic FUS formed aggregates with the sEVs marker protein CD63 in cytoplasmic stress granules (SGs) under hypoxic stress. Meanwhile, cytoplasmic FUS recruited of functional cytoplasmic circRNAs to SGs. Upon relief of hypoxic stress and degradation of SGs, cytoplasmic FUS is transported with those circRNAs from SGs to sEVs. Validation of FUS knockout dramatically reduced the recruitment of circRNAs from SGs and led to low circRNA loading in sEVs, which is also confirmed by the accumulation of circRNAs in the cytoplasm. Furthermore, it is showed that the FUS Zf_RanBP domain regulates the transport of circRNAs to sEVs by interacting with hypoxic circRNAs in SGs. Overall, these findings have revealed a FUS-mediated transport mechanism of hypoxia-related cytoplasmic circRNAs loaded into sEVs under hypoxic conditions.

Tom70-regulated mitochondrial biogenesis via TFAM improves hypoxia-induced dysfunction of pulmonary vascular endothelial cells and alleviates hypoxic pulmonary hypertension.

BACKGROUND: Hypoxic pulmonary hypertension (HPH) is a common type of pulmonary hypertension and characterized by pulmonary vascular remodeling and constriction. A large number of studies have shown that pulmonary vascular endothelial cells (PVECs) dysfunction plays an important role in the initiation and development stages of HPH, but the mechanism of PVECs dysfunction after hypoxia remains unclear. In this study, we explored the exact mechanism of PVECs dysfunction after hypoxia. METHODS: In vitro, we used primary cultured PVECs hypoxia model to mimic HPH injury. We detected the expressions of mitochondrial biogenesis markers, mitochondrial transcription factor A (TFAM) level inside mitochondria, mitochondrial quantity and function, and the components expressions of translocase of outer mitochondrial membrane (TOM) at 24 h after hypoxia. To explore the effects of Tom70 on mitochondrial biogenesis and functions of PVECs after hypoxia, Tom70 overexpression adenovirus was constructed, and the expressions of mitochondrial biogenesis markers, TFAM level inside mitochondria, mitochondrial quantity and function, and the functions of PVECs were detected. And in vivo, we used cre-dependent overexpression adenovirus of Tom70 in the Cdh5-CreERT2 mouse model of HPH to verify the role of upregulating PVECs Tom70 in improving HPH. RESULTS: Hypoxia obviously increased the expressions of mitochondrial biogenesis markers for PGC-1α, NRF-1 and TFAM, but reduced the content of TFAM in mitochondria and the quantity and functions of mitochondria. In addition, only Tom70 expression among the TOM components was significantly decreased after hypoxia, and up-regulation of Tom70 significantly increased the content of TFAM in mitochondria of PVECs by transporting TFAM into mitochondria after hypoxia, enhanced the quantity and functions of mitochondria, improved the functions of PVECs, and ultimately alleviated HPH. CONCLUSION: The findings of present study demonstrated that hypoxia induced the decreased expression of Tom70 in PVECs, reduced the mitochondrial biogenesis-associated TFAM protein transporting into mitochondria, inhibited mitochondrial biogenesis, caused PVECs injury, and prompted the formation of HPH. However, up-regulation of Tom70 abolished the hypoxia-induced injurious effects on PVECs and alleviated HPH.

FUS-mediated HypEVs: Neuroprotective effects against ischemic stroke.

Few studies have investigated the properties and protein composition of small extracellular vesicles (sEVs) derived from neurons under hypoxic conditions. Presently, the extent of the involvement of these plentiful sEVs in the onset and progression of ischemic stroke remains an unresolved question. Our study systematically identified the characteristics of sEVs derived from neurons under hypoxic conditions (HypEVs) by physical characterization, sEV absorption, proteomics and transcriptomics analysis. The effects of HypEVs on neurites, cell survival, and neuron structure were assessed in vitro and in vivo by neural complexity tests, magnetic resonance imaging (MRI), Golgi staining, and Western blotting of synaptic plasticity-related proteins and apoptotic proteins. Knockdown of Fused in Sarcoma (FUS) small interfering RNA (siRNA) was used to validate FUS-mediated HypEV neuroprotection and mitochondrial mRNA release. Hypoxia promoted the secretion of sEVs, and HypEVs were more easily taken up and utilized by recipient cells. The MRI results illustrated that the cerebral infarction volume was reduced by 45% with the application of HypEVs, in comparison to the non- HypEV treatment group. Mechanistically, the FUS protein is necessary for the uptake and neuroprotection of HypEVs against ischemic stroke as well as carrying a large amount of mitochondrial mRNA in HypEVs. However, FUS knockdown attenuated the neuroprotective rescue capabilities of HypEVs. Our comprehensive dataset clearly illustrates that FUS-mediated HypEVs deliver exceptional neuroprotective effects against ischemic stroke, primarily through the maintenance of neurite integrity and the reduction of mitochondria-associated apoptosis.

The effects of elemene emulsion injection on rat fecal microbiota and metabolites: Evidence from metagenomic exploration and liquid chromatography-mass spectrometry.

Objective: Elemene emulsion injection (EEI) has been approved for interventional and intracavitary chemotherapy in treating malignant ascites in China, but few studies have focused on the effects of EEI on gut microbiota and metabolites. In this study, we investigated the effects of EEI on the fecal microbiota and metabolites in healthy Sprague-Dawley (SD) rats. Methods: We randomly assigned 18 male SD rats to three groups (n = 6 in each group): the sham group (group S), the low-concentration EEI group (L-EEI), and the high-concentration EEI group (H-EEI). The L-EEI and H-EEI rats were administered 14 days of consecutive EEI, 20 mg/kg, and 40 mg/kg intraperitoneally (IP). Group S rats were administered the same volume of normal saline. On day 14, each animal's feces were collected for metagenomic sequencing and metabolomic analysis, and the colonic contents were collected for 16S rRNA sequencing. Results: EEI could alter the ß-diversity but not the α-diversity of the fecal microbiota and induce structural changes in the fecal microbiota. Different concentrations of EEI affect the fecal microbiota differently. The effects of different EEI concentrations on the top 20 bacteria with significant differences at the species level among the three groups were roughly divided into three categories: (1) A positive or negative correlation with the different EEI concentrations. The abundance of Ileibacterium Valens increased as the EEI concentration increased, while the abundance of Firmicutes bacteria and Clostridium sp. CAC: 273 decreased. (2) The microbiota showed a tendency to increase first, then decrease or decrease first, and then increase as EEI concentration increased-the abundance of Prevotella sp. PCHR, Escherichia coli, and Candidatus Amulumruptor caecigallinarius tended to decrease with L-EEI but significantly increased with H-EEI. In contrast, L-EEI significantly increased Ruminococcus bromii and Dorea sp. 5-2 abundance, and Oscillibacter sp. 1-3 abundance tended to increase, while H-EEI significantly decreased them. (3) L-EEI and H-EEI decreased the abundance of bacteria (Ruminococcaceae bacterium, Romboutsia ilealis, and Staphylococcus xylosus). Fecal metabolites, like microbiota, were sensitive to different EEI concentrations and correlated with fecal microbiota and potential biomarkers. Conclusion: This study shows that intraperitoneal EEI modulates the composition of rat fecal microbiota and metabolites, particularly the gut microbiota's sensitivity to different concentrations of EEI. The impact of changes in the microbiota on human health remains unknown, particularly EEI's efficacy in treating tumors.

A New Nomogram for Predicting the Risk of Intracranial Hemorrhage in Acute Ischemic Stroke Patients After Intravenous Thrombolysis.

Background: We aimed to develop and validate a new nomogram for predicting the risk of intracranial hemorrhage (ICH) in patients with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT). Methods: A retrospective study enrolled 553 patients with AIS treated with IVT. The patients were randomly divided into two cohorts: the training set (70%, n = 387) and the testing set (30%, n = 166). The factors in the predictive nomogram were filtered using multivariable logistic regression analysis. The performance of the nomogram was assessed based on the area under the receiver operating characteristic curve (AUC-ROC), calibration plots, and decision curve analysis (DCA). Results: After multivariable logistic regression analysis, certain factors, such as smoking, National Institutes of Health of Stroke Scale (NIHSS) score, blood urea nitrogen-to-creatinine ratio (BUN/Cr), and neutrophil-to-lymphocyte ratio (NLR), were found to be independent predictors of ICH and were used to construct a nomogram. The AUC-ROC values of the nomogram were 0.887 (95% CI: 0.842-0.933) and 0.776 (95% CI: 0.681-0.872) in the training and testing sets, respectively. The AUC-ROC of the nomogram was higher than that of the Multicenter Stroke Survey (MSS), Glucose, Race, Age, Sex, Systolic blood Pressure, and Severity of stroke (GRASPS), and stroke prognostication using age and NIH Stroke Scale-100 positive index (SPAN-100) scores for predicting ICH in both the training and testing sets (p < 0.05). The calibration plot demonstrated good agreement in both the training and testing sets. DCA indicated that the nomogram was clinically useful. Conclusions: The new nomogram, which included smoking, NIHSS, BUN/Cr, and NLR as variables, had the potential for predicting the risk of ICH in patients with AIS after IVT.

CircOGDH Is a Penumbra Biomarker and Therapeutic Target in Acute Ischemic Stroke.

BACKGROUND: Acute ischemic stroke (AIS) is a leading cause of disability and mortality worldwide. Prediction of penumbra existence after AIS is crucial for making decision on reperfusion therapy. Yet a fast, inexpensive, simple, and noninvasive predictive biomarker for the poststroke penumbra with clinical translational potential is still lacking. We aim to investigate whether the CircOGDH (circular RNA derived from oxoglutarate dehydrogenase) is a potential biomarker for penumbra in patients with AIS and its role in ischemic neuronal damage. METHODS: CircOGDH was screened from penumbra of middle cerebral artery occlusion mice and was assessed in plasma of patients with AIS by quantitative polymerase chain reaction. Magnetic resonance imaging was used to examine the penumbra volumes. CircOGDH interacted with miR-5112 (microRNA-5112) in primary cortical neurons was detected by fluorescence in situ hybridization, RNA immunoprecipitation, and luciferase reporter assay. Adenovirus-mediated CircOGDH knockdown ameliorated neuronal apoptosis induced by COL4A4 (Gallus collagen, type IV, alpha IV) overexpression. Transmission electron microscope, nanoparticle tracking analysis, and Western blot were performed to confirm exosomes. RESULTS: CircOGDH expression was dramatically and selectively upregulated in the penumbra tissue of middle cerebral artery occlusion mice and in the plasma of 45 patients with AIS showing a 54-fold enhancement versus noncerebrovascular disease controls. Partial regression analysis revealed that CircOGDH expression was positively correlated with the size of penumbra in patients with AIS. Sequestering of miR-5112 by CircOGDH enhanced COL4A4 expression to elevate neuron damage. Additionally, knockdown of CircOGDH significantly enhanced neuronal cell viability under ischemic conditions. Furthermore, the expression of CircOGDH in brain tissue was closely related to that in the serum of middle cerebral artery occlusion mice. Finally, we found that CircOGDH was highly expressed in plasma exosomes of patients with AIS compared with those in noncerebrovascular disease individuals. CONCLUSIONS: These results demonstrate that CircOGDH is a potential therapeutic target for regulating ischemia neuronal viability, and is enriched in neuron-derived exosomes in the peripheral blood, exhibiting a predictive biomarker of penumbra in patients with AIS.

Outcome-based student assessment enhances academic performance in basic medical laboratory course.

Basic medical laboratory courses (BMLCs) play an important role in medical educational courses helping the student acquire three important skills of surgical operating, collaborative learning, and problem solving. The outcome-based student assessment (OBSA) is a learning evaluation method that establishes specific evaluation points based on performance of students in three aspects: surgical operating, collaborative learning, and problem solving in the BMLC curriculum practices. The purpose of the present randomized controlled trial study is to explore the efficiency of OBSA program in BMLCs. The 233 students attending BMLCs were randomly divided into 2 groups, 118 in the OBSA group and 115 in the control group. We conducted multiple-choice examination questions (MCQs) test and two questionnaires with the method of two-sample t test for statistics. The results of MCQs in total eight BMLC blocks showed that the academic performance of the OBSA group was significantly better than that of the control group (P < 0.05). In addition, the average scores of direct observation of procedural skills (DOPS) and mini-experimental evaluation exercise in OBSA group were significantly higher than those in control group (P < 0.05). The majority of the medical students preferred the OBSA and considered OBSA could effectively improve their surgical operating skills (83.9%), collaborative learning skills (92.1%), and problem-solving skills (91.1%). From the above, OBSA is an effective evaluation method for the implementation of the BMLC curriculum.

Inhibition of PDE1-B by Vinpocetine Regulates Microglial Exosomes and Polarization Through Enhancing Autophagic Flux for Neuroprotection Against Ischemic Stroke.

Exosomes contribute to cell-cell communications. Emerging evidence has shown that microglial exosomes may play crucial role in regulation of neuronal functions under ischemic conditions. However, the underlying mechanisms of microglia-derived exosome biosynthesis are largely unknown. Herein, we reported that the microglial PDE1-B expression was progressively elevated in the peri-infarct region after focal middle cerebral artery occlusion. By an oxygen-glucose-deprivation (OGD) ischemic model in cells, we found that inhibition of PDE1-B by vinpocetine in the microglial cells promoted M2 and inhibited M1 phenotype. In addition, knockdown or inhibition of PDE1-B significantly enhanced the autophagic flux in BV2 cells, and vinpocetine-mediated suppression of M1 phenotype was dependent on autophagy in ischemic conditions. Co-culture of BV2 cells and neurons revealed that vinpocetine-treated BV2 cells alleviated OGD-induced neuronal damage, and treatment of BV2 cells with 3-MA abolished the observed effects of vinpocetine. We further demonstrated that ischemia and vinpocetine treatment significantly altered microglial exosome biogenesis and release, which could be taken up by recipient neurons and regulated neuronal damage. Finally, we showed that the isolated exosome per se from conditioned BV2 cells is sufficient to regulate cortical neuronal survival in vivo. Taken together, these results revealed a novel microglia-neuron interaction mediated by microglia-derived exosomes under ischemic conditions. Our findings further suggest that PDE1-B regulates autophagic flux and exosome biogenesis in microglia which plays a crucial role in neuronal survival under cerebral ischemic conditions.

The effect of HMG-CoA reductase inhibitors on thrombolysis-induced haemorrhagic transformation.

Thrombolysis-induced haemorrhagic transformation is the most challenging preventable complication in thrombolytic therapy. This condition is often associated with poor functional outcome and long-term disease burden. Statins, or 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are controversially suggested to either increase or decrease the odds of better primary outcomes compared to treatment without statins after thrombolysis in patients or animals; statins are thought to act by influencing lipid levels, the inflammatory response, blood brain barrier permeability and cell apoptosis. Statins are the cornerstone of secondary prevention of cardiovascular and cerebrovascular diseases. However, the role of statins in acute phase stroke, and the necessity of their use, remains unclear. Currently, whether statins can increase the risk of haemorrhagic transformation is of great concern for patients treated with tissue plasminogen activator (t-PA). Herein, we thoroughly summarize the recent advances that address whether the administration of statins in ischaemic stroke increases haemorrhagic transformation in patients or animals who received thrombolysis at an early stage and the related mechanisms. This review will provide more clinical and preclinical evidence to address questions regarding the exercise of caution in the use of high dose statins in patients who received thrombolysis and if low dose statins may be beneficial in decreasing thrombolysis-induced haemorrhagic transformation.

Differential DNA methylation in newborns with maternal exposure to heavy metals from an e-waste recycling area.

This study explored the effects of maternal exposure to e-waste environmental heavy metals on neonatal DNA methylation patterns. Neonatal umbilical cord blood (UCB) samples were collected from participants that resided in an e-waste recycling area, Guiyu and a nearby non-e-waste area, Haojiang in China. The concentrations of UCB lead (Pb), cadmium (Cd), manganese (Mn) and chromium (Cr) were measured by graphite furnace atomic absorption spectrometry. Epigenome-wide DNA methylation at 473, 844 CpG sites (CpGs) were assessed by Illumina 450 K BeadChip. The differential methylation of CpG sites from the microarray were further validated by bisulfite pyrosequencing. Bioinformatics analysis showed that 125 CpGs mapped to 79 genes were differential methylation in the e-waste exposed group with higher concentrations of heavy metals in neonatal UCB. These genes mainly involve in multiple biological processes including calcium ion binding, cell adhesion, embryonic morphogenesis, as well as in signaling pathways related to NFkB activation, adherens junction, TGF beta and apoptosis. Among them, BAI1 and CTNNA2 (involving in neuron differentiation and development) were further verified to be hyper- and hypo-methylated, respectively, which were associated with maternal Pb exposure. These results suggest that maternal exposure to e-waste environmental heavy metals (particularly lead) during pregnancy are associated with peripheral blood differential DNA methylation in newborns, specifically the genes involving in brain neuron development.

Maternal urinary metabolites of PAHs and its association with adverse birth outcomes in an intensive e-waste recycling area.

Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogenic and endocrine disrupting chemicals that have been concerned over the past few decades. We aimed to determine the hydroxylated PAH (OHPAH) metabolite concentrations in maternal urine collected from the e-waste-contaminated area of Guiyu and the reference area of Haojiang, China, and to evaluate their health effects on birth outcomes. The median Æ©OHPAH concentration was 6.87 µg/g creatinine from Guiyu, and 3.90 µg/g creatinine from Haojiang. 2-OHNap and 1-OHPyr were the predominant metabolites. Residence in Guiyu and recycling in houses were associated with elevated 2-OHNap and 1-OHPyr. Standardized mean difference revealed that compared to low PAH metabolite levels in the first quartile, high PAH metabolite levels in the fourth quartile especially for 1-OHPyr, Æ©OHPAHs and sometimes hydroxylphenanthrene compounds, presented a reduced size in birth outcomes (overall SMD: -0.09; 95% CI: -0.15, -0.03), including head circumference, BMI and Apgar 1 score, and increased size in height. After adjusting for confounders in regression models, an interquartile increase in ΣOHPAHs was associated with a decrease of 234.56 g in weight (95% CI: -452.00, -17.13), 1.72 cm in head circumference (95% CI: -2.96, -0.48), 1.06 kg/m2 in BMI (95% CI: -1.82, -0.31) and 0.42 in Apgar 1 score (95% CI: -0.66, -0.18), respectively. These findings suggest high exposure to PAHs during pregnancy in e-waste areas, posing a potential threat to neonatal development, which likely can be attributed to direct e-waste recycling activities. Ongoing studies should be continued to monitor human exposure and health, in particular for vulnerable individuals in e-waste-polluted areas.

Increased mtDNA copy number promotes cancer progression by enhancing mitochondrial oxidative phosphorylation in microsatellite-stable colorectal cancer.

Colorectal cancer is one of the leading causes of cancer death worldwide. According to global genomic status, colorectal cancer can be classified into two main types: microsatellite-stable and microsatellite-instable tumors. Moreover, the two subtypes also exhibit different responses to chemotherapeutic agents through distinctive molecular mechanisms. Recently, mitochondrial DNA depletion has been shown to induce apoptotic resistance in microsatellite-instable colorectal cancer. However, the effects of altered mitochondrial DNA copy number on the progression of microsatellite-stable colorectal cancer, which accounts for the majority of colorectal cancer, remain unclear. In this study, we systematically investigated the functional role of altered mitochondrial DNA copy number in the survival and metastasis of microsatellite-stable colorectal cancer cells. Moreover, the underlying molecular mechanisms were also explored. Our results demonstrated that increased mitochondrial DNA copy number by forced mitochondrial transcription factor A expression significantly facilitated cell proliferation and inhibited apoptosis of microsatellite-stable colorectal cancer cells both in vitro and in vivo. Moreover, we demonstrated that increased mitochondrial DNA copy number enhanced the metastasis of microsatellite-stable colorectal cancer cells. Mechanistically, the survival advantage conferred by increased mitochondrial DNA copy number was caused in large part by elevated mitochondrial oxidative phosphorylation. Furthermore, treatment with oligomycin significantly suppressed the survival and metastasis of microsatellite-stable colorectal cancer cells with increased mitochondrial DNA copy number. Our study provides evidence supporting a possible tumor-promoting role for mitochondrial DNA and uncovers the underlying mechanism, which suggests a potential novel therapeutic target for microsatellite-stable colorectal cancer.

TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells.

BACKGROUND: Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. METHODS: The level of cytosolic Ca2+ was assessed by Fura-2 in HCC cells. After changing cytosolic Ca2+ level by using agonists or inhibitors, cell apoptosis was detected by flow cytometry. We also detected the effect of ionomycin or parvalbumin on the anti-tumor activity of TNFα in a mice model. Lastly, we studied the roles of cytosolic Ca2+ in the mitochondrial-dependent intrinsic apoptosis pathway. RESULTS: Here, we demonstrated that TNFα induced extracellular Ca2+ influx into cytoplasm through transient receptor potential channel in HCC cells. Both cytosolic Ca2+ scavenger and Ca2+-binding protein PV effectively desensitized hepatocellular carcinoma cells to TNFα, whereas combination ionomycin or 1,4,5-inositol triphosphate significantly sensitized HCC cells to TNFα, indicating that the increased level of cytosolic Ca2+ was positively correlated with the TNFα-induced cell apoptosis in vitro. In a nude mice xenograft model, our data revealed that TNFα combined with ionomycin remarkably synergized the anti-tumor effect of TNFα. Furthermore, we found that TNFα-mediated extracellular Ca2+ influx accelerated TNFα-induced extrinsic apoptosis through activating calpain/IAP/caspase3 pathway. CONCLUSIONS: Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular Ca2+ influx to enhance cell apoptosis and suggests that increasing the level of cytosolic Ca2+ might be an alternative strategy to improve the pro-apoptotic activity of TNFα in HCC cells, although suitable chemical or biological reagents need to be further tested.

MCUR1-Mediated Mitochondrial Calcium Signaling Facilitates Cell Survival of Hepatocellular Carcinoma via Reactive Oxygen Species-Dependent P53 Degradation.

AIMS: Levels of the mitochondrial calcium uniporter regulator 1 (MCUR1) increases during development of hepatocellular carcinoma (HCC). However, mechanisms of how mitochondrial Ca2+ homeostasis is modulated and its function remain limited in cancers. RESULTS: MCUR1 was frequently upregulated in HCC cells to enhance the Ca2+ uptake into mitochondria in an MCU-dependent manner, which significantly facilitated cell survival by inhibiting mitochondria-dependent intrinsic apoptosis and promoting proliferation of HCC cells, and thus led to poor prognosis. In vivo assay confirmed these results, indicating that overexpressed MCUR1 notably decreased the fraction of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells and increased the positive Ki67 staining in xenograft tumors, while reduced MCUR1 expression was associated with impaired growth capacity of HCC cells in nude mice. The survival advantage conferred by MCUR1-mediated mitochondrial Ca2+ uptake was majorly caused by elevated production of mitochondrial reactive oxygen species and subsequent AKT/MDM2- induced P53 degradation, which regulated the expression level of apoptosis-related molecules and cell cycle-related molecules. Treatment of mitochondrial Ca2+-buffering protein parvalbumin remarkably inhibited the growth of HCC cells. Conclusions and Innovation: Our study provides evidence supporting a possible tumor-promoting role for MCUR1-mediated mitochondrial Ca2+ uptake and uncovers a mechanistic understanding that links change of mitochondrial Ca2+ homeostasis to cancer cell survival, which suggests a potential novel therapeutic target for HCC. Antioxid. Redox Signal. 28, 1120-1136.

Assessment of health risk of trace metal pollution in surface soil and road dust from e-waste recycling area in China.

Informal recycling of e-waste and the resulting heavy metal pollution has become a serious burden on the ecosystem in Guiyu, China. In this investigation, we evaluated the trace metal concentration of community soil and road dust samples from 11 locations in Guiyu and 5 locations (consisting of residential areas, kindergarten/school, and farm field) in a reference area using graphite furnace atomic absorption spectrophotometer. The study spanned four seasons, 2012-2013, with a view to assess the risk associated with e-waste recycling in the study area. The concentrations of Pb, Cd, Cr, and Mn were 448.73, 0.71, 63.90, and 806.54 mg/kg in Guiyu soil and 589.74, 1.94, 69.71, and 693.74 mg/kg, in the dust, respectively. Pb and Cd values were significantly higher (P ≤ 0.05) than the reference area, and the mixed model analysis with repeated seasonal measurements revealed soil Pb and Cd levels that were 2.32 and 4.34 times, while the ratios for dust sample were 4.10 and 3.18 times higher than the reference area. Contamination factor, degree of contamination, and pollution load index indicated that all sampling points had a high level of metal contamination except farm land and kindergarten compound. The cumulative hazard index of Pb, Cd, Cr, and Mn for children in exposed area was 0.99 and 1.62 for soil and dust, respectively, suggesting non-cancer health risk potential. The significant accumulation of trace metals in the e-waste recycling area predisposes human life, especially children, to a potentially serious health risk.

Genetic Variants in ASCT2 Gene are Associated with the Prognosis of Transarterial Chemoembolisation-Treated Early- Stage Hepatocelluar Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide. Transarterial chemoembolisation (TACE) is the standardized therapy for intermediate stage HCC. However, the prognosis for HCC patients treated by TACE greatly varies. Thus, there is a critical need for finding biomarkers to predict the prognosis of HCC patients. The amino acid transporter-2 (ASCT2) is involved in tumorigenesis and progression of many malignancies. This study aimed to evaluate the predictive role of two single nuclear polymorphisms (SNPs, rs3826793 and rs2070246) in the ASCT2 gene in HCC patients treated by TACE. MATERIALS AND METHODS: Two functional SNPs (rs3826793 and rs2070246) in the ASCT2 gene were selected and genotyped using the Sequenom iPLEX genotyping system in a cohort of 448 unresectable Chinese HCC patients treated by TACE. Univariate and multivariate Cox proportional hazards models and Kaplan-Meier curves were used for the prognosis analyses. RESULTS: There was no significant association between two SNPs (rs3826793 and rs2070246) in the ASCT2 gene and overall survival of TACE treated HCC patients. However, we demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype (P=0.023). CONCLUSIONS: We demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype.

Polymorphisms in Genes of Tricarboxylic Acid Cycle Key Enzymes Are Associated with Early Recurrence of Hepatocellular Carcinoma.

Alterations of activity and expression in tricarboxylic acid (TCA) cycle key enzymes have been indicated in several malignancies, including hepatocellular carcinoma (HCC). They play an important role in the progression of cancer. However, the impact of single nucleotide polymorphisms (SNPs) in genes encoding these key enzymes on the recurrence of HCC has not been investigated. In this study, we genotyped 17 SNPs in genes encoding TCA cycle key enzymes and analyzed their association with recurrence-free survival (RFS) in a cohort of 492 Chinese HCC patients by Cox proportional hazard model and survival tree analysis. We identified 7 SNPs in SDHC, SDHD, FH, and IDH2 genes to be significantly associated with the RFS of HCC patients. Moreover, all these SNPs were associated with the early recurrence (within 2 years after surgery) risk of diseases. Cumulative effect analysis showed that these SNPs exhibited a dose-dependent effect on the overall and early recurrence. Further stratified analysis suggested that number of risk genotypes modified the protective effect on HCC recurrence conferred by transcatheter arterial chemoembolization treatment. Finally, the survival tree analysis revealed that SNP rs10789859 in SDHD gene was the primary factor contributing to HCC recurrence in our population. To the best of our knowledge, we for the first time observed the association between SNPs in genes encoding TCA cycle key enzymes and HCC recurrence risk. Further observational and functional studies are needed to validate our findings and generalize its clinical usage.

Polymorphisms in genes of the de novo lipogenesis pathway and overall survival of hepatocellular carcinoma patients undergoing transarterial chemoembolization.

Aberrant expression of genes in de novo lipogenesis (DNL) pathway were associated with various cancers, including hepatocellular carcinoma (HCC). Single nucleotide polymorphisms (SNPs) of DNL genes have been reported to be associated with prognosis of some malignancies. However, the effects of SNPs in DNL genes on overall survival of HCC patients receiving transarterial chemoembolization (TACE) treatment are still unknown. In present study, nine SNPs in three genes (ACLY, ACACA and FASN) in DNL pathway were genotyped using the Sequenom iPLEX genotyping system in a hospital-based cohort with 419 HCC patients treated with TACE, and their associations with HCC overall survival were evaluated by Cox proportional hazard regression analysis under three genetic models (additive, dominant and recessive). Although we did not find any significant results in total analysis (all p>0.05), our stratified data showed that SNP rs9912300 in ACLY gene was significantly associated with overall survival of HCC patients with lower AFP level and SNP rs11871275 in ACACA gene was significantly associated with overall survival of HCC patients with higher AFP level. We further identified the significant interactions between AFP level and SNP rs9912300 or rs11871275 in the joint analysis. Conclusively, our data suggest that genetic variations in genes of DNL pathway may be a potential biomarker for predicting clinical outcome of HCC patients treated with TACE.

Leukocyte telomere length: a novel biomarker to predict the prognosis of glioma patients.

PURPOSE: Epidemiological studies have demonstrated that leukocyte telomere length is associated with the developing risk of various malignancies, including glioma. However, its prognostic value in glioma patients has never been investigated. METHODS: Relative telomere length (RTL) of peripheral blood leukocytes from 301 glioma patients were examined using a real-time PCR-based method. Kaplan-Meier curves and Cox proportional hazards regression model were used to assess the association of RTL with clinical outcomes of patients. To explore the potential mechanism, the immune phenotype of peripheral blood mononuclear cells (PBMCs) and concentrations of several cytokines from another 20 glioma patients were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The relationship between RTL and immunological characteristics of PBMCs were further analyzed. RESULTS: Patients with short RTL showed both poorer overall survival (OS) and progression-free survival (PFS) than those with long RTL. Multivariate Cox regression analysis demonstrated that RTL was an independent prognostic factor for both OS and PFS in glioma patients. Moreover, the effects of RTL on the prognosis of patients exhibited a dose-dependent manner. Stratified analysis showed that the prognostic value of RTL was not affected by host characteristics except for age. In addition, flow cytometry and ELISA analyses indicated that there was no significant association between RTL and frequency of different immune cell subsets or plasma cytokine concentrations. CONCLUSIONS: Our study for the first time demonstrates that leukocyte RTL is an independent prognostic marker for glioma patients. The potential mechanism needs further investigation.