Ferrate(VI)-based oxidation for ultrafiltration membrane fouling mitigation in shale gas produced water pretreatment: Role of high-valent iron intermediates and hydroxyl radicals.

Ultrafiltration (UF) is increasingly used in the pretreatment of shale gas produced water (SGPW), whereas severe membrane fouling hampers its actual operation. In this work, ferrate(VI)-based oxidation was proposed for membrane fouling alleviation in SGPW pretreatment, and the activation strategies of calcium peroxide (CaO2) and ultraviolet (UV) were selected for comparison. The findings indicated that UV/Fe(VI) was more effective in removing fluorescent components, and the concentration of dissolved organic carbon was reduced by 24.1 %. With pretreatments of CaO2/Fe(VI) and UV/Fe(VI), the terminal specific membrane flux was elevated from 0.196 to 0.385 and 0.512, and the total fouling resistance diminished by 52.7 % and 76.2 %, respectively. Interfacial free energy analysis indicated that the repulsive interactions between pollutants and membrane were notably enhanced by Fe(VI)-based oxidation, thereby delaying the deposition of cake layers on the membrane surface. Quenching and probe experiments revealed that high-valent iron intermediates (Fe(IV)/Fe(V)) played significant roles in both CaO2/Fe(VI) and UV/Fe(VI) processes. Besides, hydroxyl radicals (•OH) were also important reactive species in the UV/Fe(VI) treatment, and the synergistic effect of Fe(IV)/Fe(V) and •OH showed a positive influence on SGPW fouling mitigation. In general, these findings establish a theoretical underpinning for the application of Fe(VI)-based oxidation for UF membrane fouling mitigation in SGPW pretreatment.

Casticin induces ferroptosis in human osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4.

Osteosarcoma is a primary solid bone malignancy, and surgery + chemotherapy is the most commonly used treatment. However, chemotherapeutic drugs can cause a range of side effects. Casticin, a polymethoxyflavonoid, has anti-tumor therapeutic effects. This study is aim to investigate the anti-osteosarcoma activity of casticin and explore the mechanism. Crystal violet staining, MTT assay, colony formation assay, wound healing assay, transwell assay, hoechst 33,258 staining, and flow cytometry analysis were used to investigate the effects of casticin on proliferation, migration, invasion, and apoptosis of osteosarcoma cells in vitro. The intracellular Fe2+, ROS, MDA, GSH/GSSG content changes were detected using the corresponding assay kits. The mRNA sequencing + bioinformatics analysis and western blot were used to detect the possible mechanism. We found that casticin caused G2/M phase cell cycle arrest in human osteosarcoma cells, inhibited the migration and invasion, and induced cell apoptosis and ferroptosis. Mechanistic studies showed the ferroptosis pathway was enriched stronger than apoptosis. Casticin up-regulated the expression of HMOX1, LC3 and NCOA4, meanwhile it activated MAPK signaling pathways. Animal experiments proved that casticin also inhibited the growth and metastasis of osteosarcoma cell xenograft tumor in vivo. In conclusion, casticin can induce ferroptosis in osteosarcoma cells through Fe2+ overload and ROS production mediated by HMOX1 and LC3-NCOA4. This provides a new strategy for osteosarcoma treatment.

Association between lactate dehydrogenase to albumin ratio and acute kidney injury in patients with sepsis: a retrospective cohort study.

BACKGROUND: Serum lactate dehydrogenase to albumin ratio (LAR) is associated with poor outcomes in malignancy and pneumonia. However, there are few studies suggesting that LAR is associated with the occurrence of acute kidney injury (AKI) in patients with sepsis, which was investigated in this study. METHODS: We conducted a retrospective cohort study based on the Medical Information Mart for Intensive Care (MIMIC)-IV database. The primary outcome was the occurrence of AKI within 2 days and 7 days. Multivariable logistic regression models were used to calculate odds ratios to validate the association between LAR and AKI, in-hospital mortality, RRT use, and recovery of renal function, respectively. RESULTS: A total of 4010 participants were included in this study. The median age of the participants was 63.5 years and the median LAR was 10.5. After adjusting for confounding variables, patients in the highest LAR quartile had a higher risk of AKI than those in the lowest LAR quartile within 2 days and 7 days, with odds ratios of 1.37 (95% confidence interval [CI]: 1.23-1.52) and 1.95 (95% CI: 1.72-2.22), respectively. The adjusted odds of AKI within 2 and 7 days were 1.16 (95% CI: 1.12-1.20) and 1.29 (95% CI: 1.24-1.35) for each 1 unit increase in LAR(log2), respectively. CONCLUSION: This study demonstrated that elevated LAR was associated with poor prognosis in patients with sepsis. The risk of AKI and in-hospital mortality increased, the need for RRT increased, and the chance of recovery of renal function decreased with the increase of LAR.

Aging of polypropylene plastic and impacts on microbial community structure in constructed wetlands.

The COVID-19 pandemic has resulted in a substantial surge in the usage of disposable plastic masks, generating a significant volume of waste and contributing to environmental pollution. Wetland ecosystems function as crucial repositories for terrestrial pollutants and are highly effective in retaining disposable masks composed mainly of PP material. These masks can endure extended periods in wetlands, experiencing natural degradation that may have potential implications on wetland ecosystems. Our findings demonstrate the natural aging process of disposable masks, resulting in the generation of microplastics (MPs) ranging in diameter from 10 to 30 µm over a 180-day timeframe. Examination of 16S rDNA data unveiled temporal fluctuations in microbial diversity in the wetland ecosystem. Initially, microbial diversity displayed a modest incline, which was succeeded by a subsequent decrease. With the progressive accumulation of plastic within the wetland, an ongoing decline in microbial diversity linked to nitrogen transformation was observed. This study provides valuable insights into the retention of disposable masks by wetlands amidst the COVID-19 pandemic, along with their consequential effects on wetland ecosystems, specifically pertaining to nitrogen cycling. It underscores the urgency of augmenting the safeguarding measures for wetland ecosystems.

Genipin Inhibits the Development of Osteosarcoma through PI3K/AKT Signaling Pathway.

BACKGROUND: Osteosarcoma is a highly invasive and early metastatic tumor. At present, the toxic and side effects of chemotherapy affect the quality of life of cancer patients to varying degrees. Genipin is an extract of the natural medicine gardenia with various pharmacological activities. OBJECTIVE: The purpose of this study was to investigate the effect of Genipin on osteosarcoma and its potential mechanism of action. METHODS: Crystal violet staining, MTT assay and colony formation assay were used to detect the effect of genipin on the proliferation of osteosarcoma. The effects of vitexin on migration and invasion of osteosarcoma were detected by scratch healing assay and transwell assay. Hoechst staining and flow cytometry were used to detect the effect of genipin on apoptosis of osteosarcoma cells. The expression of related proteins was detected by Western blot. An orthotopic tumorigenic animal model was used to verify the effect of genipin on osteosarcoma in vivo. RESULTS: The results of crystal violet staining, MTT method and colony formation method proved that genipin significantly inhibited the proliferation of osteosarcoma cells. The results of the scratch healing assay and transwell assay showed that gen significantly inhibited the migration and invasion of osteosarcoma cells. The results of Hoechst staining and flow cytometry showed that genipin significantly promoted the apoptosis of osteosarcoma cells. The results of animal experiments show that genipin has the same anti-tumor effect in vivo. Genipin may inhibit the growth of osteosarcoma through PI3K/AKT signaling. CONCLUSION: Genipin can inhibit the growth of human osteosarcoma cells, and its mechanism may be related to the regulation of PI3K/AKT signaling pathway.

Echinatin inhibits the growth and metastasis of human osteosarcoma cells through Wnt/ß-catenin and p38 signaling pathways.

Osteosarcoma (OS) is a highly aggressive malignant bone tumor that mainly occurs in adolescents. At present, chemotherapy is the most commonly used method in clinical practice to treat OS. However, due to drug resistance, toxicity and long-term side effects, chemotherapy can't always provide sufficient benefits for OS patients, especially those with metastasis and recurrence. Natural products have long been an excellent source of anti-tumor drug development. In the current study, we evaluated the anti-OS activity of Echinatin (Ecn), a natural active component from the roots and rhizomes of licorice, and explored the possible mechanism. We found that Ecn inhibited the proliferation of human OS cells and blocked cell cycle at S phase. In addition, Ecn suppressed the migration and invasion, while induced the apoptosis of human OS cells. However, Ecn had less cytotoxicity against normal cells. Moreover, Ecn inhibited the xenograft tumor growth of OS cells in vivo. Mechanistically, Ecn inactivated Wnt/ß-catenin signaling pathway while activated p38 signaling pathway. ß-catenin over-expression and the p38 inhibitor SB203580 both attenuated the inhibitory effect of Ecn on OS cells. Notably, we demonstrated that Ecn exhibited synergistic inhibitory effect with cisplatin (DDP) on OS cells in vitro and in vivo. Therefore, our results suggest that Ecn may exert anti-OS effects at least partly through regulating Wnt/ß-catenin and p38 signaling pathways. Most meaningfully, the results obtained suggest a potential strategy to improve the DDP-induced tumor-killing effect on OS cells by combining with Ecn.

Inhibition of Macropinocytosis Enhances the Sensitivity of Osteosarcoma Cells to Benzethonium Chloride.

Osteosarcoma (OS) is a primary malignant tumor of bone. Chemotherapy is one of the crucial approaches to prevent its metastasis and improve prognosis. Despite continuous improvements in the clinical treatment of OS, tumor resistance and metastasis remain dominant clinical challenges. Macropinocytosis, a form of non-selective nutrient endocytosis, has received increasing attention as a novel target for cancer therapy, yet its role in OS cells remains obscure. Benzethonium chloride (BZN) is an FDA-approved antiseptic and bactericide with broad-spectrum anticancer effects. Here, we described that BZN suppressed the proliferation, migration, and invasion of OS cells in vitro and in vivo, but simultaneously promoted the massive accumulation of cytoplasmic vacuoles as well. Mechanistically, BZN repressed the ERK1/2 signaling pathway, and the ERK1/2 activator partially neutralized the inhibitory effect of BZN on OS cells. Subsequently, we demonstrated that vacuoles originated from macropinocytosis and indicated that OS cells might employ macropinocytosis as a compensatory survival mechanism in response to BZN. Remarkably, macropinocytosis inhibitors enhanced the anti-OS effect of BZN in vitro and in vivo. In conclusion, our results suggest that BZN may inhibit OS cells by repressing the ERK1/2 signaling pathway and propose a potential strategy to enhance the BZN-induced inhibitory effect by suppressing macropinocytosis.

Construction of biomimetic cell-sheet-engineered periosteum with a double cell sheet to repair calvarial defects of rats.

Background: The periosteum plays a crucial role in the development and injury healing process of bone. The purpose of this study was to construct a biomimetic periosteum with a double cell sheet for bone tissue regeneration. Methods: In vitro, the human amniotic mesenchymal stem cells (hAMSCs) sheet was first fabricated by adding 50 â€‹µg/ml ascorbic acid to the cell sheet induction medium. Characterization of the hAMSCs sheet was tested by general observation, microscopic observation, live/dead staining, scanning electron microscopy (SEM) and hematoxylin and eosin (HE) staining. Afterwards, the osteogenic cell sheet and vascular cell sheet were constructed and evaluated by general observation, alkaline phosphatase (ALP) staining, Alizarin Red S staining, SEM, live/dead staining and CD31 immunofluorescent staining for characterization. Then, we prepared the double cell sheet. In vivo, rat calvarial defect model was introduced to verify the regeneration of bone defects treated by different methods. Calvarial defects (diameter: 4 â€‹mm) were created of Sprague-Dawley rats. The rats were randomly divided into 4 groups: the control group, the osteogenic cell sheet group, the vascular cell sheet group and the double cell sheet group. Macroscopic, micro-CT and histological evaluations of the regenerated bone were performed to assess the treatment results at 8 weeks and 12 weeks after surgery. Results: In vitro, hAMSCs sheet was successfully prepared. The hAMSCs sheet consisted of a large number of live hAMSCs and abundant extracellular matrix (ECM) that secreted by hAMSCs, as evidenced by macroscopic/microscopic observation, live/dead staining, SEM and HE staining. Besides, the osteogenic cell sheet and the vascular cell sheet were successfully prepared, which were verified by general observation, ALP staining, Alizarin Red S staining, SEM and CD31 immunofluorescent staining. In vivo, the macroscopic observation and micro-CT results both demonstrated that the double cell sheet group had better effect on bone regeneration than other groups. In addition, histological assessments indicated that large amounts of new bone had formed in the calvarial defects and more mature collagen in the double cell sheet group. Conclusion: The double cell sheet could promote to repair calvarial defects of rats and accelerate bone regeneration. The translational potential of this article: We successfully constructed a biomimetic cell-sheet-engineered periosteum with a double cell sheet by a simple, low-cost and effective method. This biomimetic periosteum may be a promising therapeutic strategy for the treatment of bone defects, which may be used in clinic in the future.

Association between red blood cell distribution width to albumin ratio and prognosis of patients with sepsis: A retrospective cohort study.

Background: Red blood cell distribution width (RDW) to albumin ratio (RAR) is associated with poor prognosis in diabetic comorbidities and cancer. However, the association between RAR and prognosis in patients with sepsis remains unclear, which was investigated in this study. Methods: We conducted a retrospective cohort study based on the Medical Information Mart for Intensive Care (MIMIC) IV version 2.0 database. The primary outcome of this study was 28-day mortality. Secondary outcomes included 90-day mortality, in-hospital mortality, length of hospital stay, and length of intensive care unit (ICU) stay. Multivariate regression analysis and subgroup analysis were performed to investigate the association between RAR and prognosis in patients with sepsis. Results: A total of 14,639 participants were included in this study. The mean age of the participants was 65.2 ± 16.3 years and the mean RAR was 5.5 ± 1.9 % /g/dl. For 28-day mortality, after adjusting for covariates, HRs [95% confidence intervals (CIs)] for tertiles 2 (4.4-5.8) and 3 (RAR > 5.8) were 1.33 (1.20, 1.46) and 1.98 (1.79, 2.19), respectively. Similar results were observed for 90-day mortality and in-hospital mortality. According to Kaplan-Meier curve analysis, the higher RAR group had higher 28-day mortality and 90-day mortality. Conclusion: Our study shows that RAR is significantly associated with poor clinical prognosis in sepsis. The higher the RAR, the higher the 28-day, 90-day, and in-hospital mortality.

Global publication trends and research hotspots of curcumin application in tumor: A 20-year bibliometric approach.

Malignant tumor is a disease caused by the imbalance of cell growth and proliferation mechanism, which seriously threatens human health and life safety. However, side effects and drug resistance are the key factors that limit the efficacy of anti-tumor drugs. Therefore, it is urgent and necessary to explore and unearth natural, safe and effective chemosensitizers in tumor researches. Curcumin is the main active ingredient in Curcuma, which has anti-inflammatory, anti-inflammatory and anti-oxidation effects, and has inhibitory effects on a variety of cancers. Bibliometric analysis is a scientific and quantitative method to assess the published articles, which can help researchers to find the development trends and the research hotspots of a specific research field, providing the development of future research for researchers. This study searched the Web Science Core Collection (woscc) for publications related to curcumin and tumors from January 1, 2001 to December 31, 2021. The specific characteristics of 1707 publications were analyzed by using Microsoft Excel software, CiteSpace, Vosviewer and online analysis platform of literature metrology. China had the largest number of published articles, with 579 publications. Aggarwal BB's articles total citations and average citations were the most. PLoS One had the largest number of publications, with 32 publications. The current research focuses on "nanoparticles", "delivery", "micells" and "doxorubicin". At present, nano based drug delivery system to improve the bioavailability of curcumin and thus to treat tumors will be the focus of future research.

A Novel Ferroptosis-Related Gene Signature for Prognosis Prediction in Ewing Sarcoma.

Ferroptosis, as a form of programmed cell death independent of apoptosis, has been demonstrated that plays a major role in tumorigenesis and cancer treatment. A comprehensive analysis of ferroptosis-related genes (FRGs) may lead to a novel choice for the treatment of Ewing sarcoma (ES). Here, 148 differentially expressed FRGs (DEFRGs) were identified between normal and ES tissue. And the GO and KEGG analyses of DEFRGs indicated that these genes were enriched in cancer and immune-related signaling pathways. Then, the GSE17679 cohort was randomly divided into train and test cohorts. Based on the train cohort, AURKA, RGS4, and RIPK1 were identified as key genes through the univariate Cox regression analysis, the random survival forest algorithm, and the multivariate Cox regression analysis and utilized to establish a prognostic FRG signature. The validation results demonstrated that the gene signature has not only excellent prediction performance and generalization ability but is also good at predicting the response of immunotherapy and chemotherapy. Subsequent analysis indicated that all 3 key genes play key roles in tumor immunity and prognosis of ES. Of these, AURKA was highly associated with EWSR1, which was verified by a single-cell dataset (GSE130019). Therefore, the 3 genes may be potential therapeutic targets for ES. At the end of this study, we also constructed an accurate nomogram that helps clinicians to assess the survival time of ES patients. In conclusion, our study constructed an excellent gene signature, which is helpful in improving the prognosis of ES patients.

Application of constructed wetlands in the PAH remediation of surface water: A review.

Polycyclic aromatic hydrocarbons (PAHs) pose adverse risks to ecosystems and public health because of their carcinogenicity and mutagenicity. As such, the extensive occurrence of PAHs represents a worldwide concern that requires urgent solutions. Wastewater treatment plants are not, however, designed for PAH removal and often become sources of the PAHs entering surface waters. Among the technologies applied in PAH remediation, constructed wetlands (CWs) exhibit several cost-effective and eco-friendly advantages, yet a systematic examination of the application and success of CWs for PAH remediation is missing. This review discusses PAH occurrence, distribution, and seasonal patterns in surface waters during the last decade to provide baseline information for risk control and further treatment. Furthermore, based on the application of CWs in PAH remediation, progress in understanding and optimising PAH-removal mechanisms is discussed focussing on sediments, plants, and microorganisms. Wetland plant traits are key factors affecting the mechanisms of PAH removal in CWs, including adsorption, uptake, phytovolatilization, and biodegradation. The physico-chemical characteristics of PAHs, environmental conditions, wetland configuration, and operation parameters are also reviewed as important factors affecting PAH removal efficiency. Whilst significant progress has been made, several key problems need to be addressed to ensure the success of large-scale CW projects. These include improving performance in cold climates and addressing the toxic threshold effects of PAHs on wetland plants. Overall, this review provides future direction for research on PAH removal using CWs and their large-scale operation for the treatment of PAH-contaminated surface waters.

Astrocyte-Derived Lipocalin-2 Is Involved in Mitochondrion-Related Neuronal Apoptosis Induced by Methamphetamine.

Methamphetamine (METH) is a widely abused and highly addictive psychoactive stimulant that can induce neuronal apoptosis. Lipocalin-2 (LCN2) is a member of the lipocalin family, and its upregulation is involved in cell death in the adult brain. However, the role of LCN2 in METH-induced neurotoxicity has not been reported. In this study, we found that LCN2 was predominantly expressed in hippocampal astrocytes after METH exposure and that recombinant LCN2 (Re LCN2) can induce neuronal apoptosis in vitro and in vivo. The inhibition of LCN2 and LCN2R, a cell surface receptor for LCN2, reduced METH- and Re LCN2-induced mitochondrion-related neuronal apoptosis in cultures of primary rat neurons and animal models. Our study supports the role of reactive oxygen species (ROS) generation and the PRKR-like ER kinase (PERK)-mediated signaling pathway in the upregulation of astrocyte-derived LCN2 after METH exposure. Additionally, the serum and cerebrospinal fluid (CSF) levels of LCN2 were significantly upregulated after METH exposure. These results indicate that upregulation of astrocyte-derived LCN2 binding to LCN2R is involved in METH-induced mitochondrion-related neuronal apoptosis.

Luteolin alleviates methamphetamine-induced neurotoxicity by suppressing PI3K/Akt pathway-modulated apoptosis and autophagy in rats.

Methamphetamine (METH) is a highly addictive stimulant that results in serious and persistent neurotoxic effects. Studies have indicated that luteolin, a flavonoid, may confer neuroprotection against neurotoxicity. Nevertheless, the effects of luteolin on METH-induced neurotoxicity have not been sufficiently verified. In the present study, Sprague Dawley rats were pretreated with luteolin (100 mg/kg) or sodium dodecyl sulfate water, followed by administration of METH (15 mg/kg) or saline. Rat striata were then collected for RNA-sequencing and subsequent analyses. A total of 347 differentially expressed genes (DEGs) were identified in the METH group with 20 pathways, including the phosphoinositol 3 kinase (PI3K)/protein kinase B (Akt), found to be enriched by the KEGG analysis. Seventy-five of the 347 DEGs were modulated in luteolin-pretreated rats, which were enriched into 12 pathways, containing the PI3K/Akt. Results further showed that luteolin pretreatment significantly repressed the METH-induced increases of PI3K, Akt, p-Akt, p53, Bax, caspase 3, normalized the ratio of p-Akt/Akt, and autophagy-related proteins (Beclin1, Atg5 and LC3-II) expression. Taken together, these findings indicate that luteolin attenuates METH-induced apoptosis and autophagy by suppressing the PI3K/Akt pathway. In this case, it exerts protection against METH-induced neurotoxicity. This provides a platform for development of potential therapies for METH treatment.

Anti-Inflammatory and Antioxidant Effects of Acetyl-L-Carnitine on Atherosclerotic Rats.

BACKGROUND The purpose of the present study was to evaluate the regulatory effects of acetyl-L-carnitine (ALCAR) on atherosclerosis in Wister rats and to explore its anti-atherosclerotic mechanism. MATERIAL AND METHODS We randomly divided 32 Wister rats into 4 groups: a normal diet group (control group, n=8), a normal diet+ALCAR group (ALCAR group, n=8), an atherosclerosis group (AS group, n=8), and an atherosclerosis+ALCAR group (AS+ALCAR group, n=8). The serum lipid distribution, oxidative stress, inflammatory factors and adiponectin (APN) in the blood, and heart and aortic tissues were determined using the standard assay kits, xanthine oxidase method, and ELISA, respectively. HE staining was performed to observe aortic pathology structure change, and the level of angiotensin II (AngII) in the aorta was assessed using radioimmunoassay. In addition, real-time quantitative PCR and Western blot analysis were applied to detect the expression of iNOS, IL-1ß, TNF-alpha, and CRP in the aortic and heart tissues. RESULTS Compared with the AS group, the levels of serum TC, TG, LDL, and VLDL in rats decreased significantly, while HDL level significantly increased in the AS+ALCAR group. ALCAR administration enhanced the SOD and GSH-Px activities and decreased MDA activity. APN level was significantly elevated in the AS group, but ALCAR had no significant effect on APN. Further, ALCAR reduced the expressions of inflammation factors TNF-alpha, IL-1ß, iNOS, and CRP, and the concentration of AngII in serum, aortic, and heart tissues. CONCLUSIONS ALCAR can inhibit the expressions of inflammatory factors and antioxidation to suppress the development of atherosclerosis by adjusting blood lipid in the myocardium of AS rats.

Decreased mRNA levels of cardiac Cx43 and ZO1 in sudden cardiac death related to coronary atherosclerosis: a pilot study.

Sudden cardiac death (SCD) is the most frequent cause of sudden unexplained death in forensic practice. The most common cause of SCD is coronary artery disease related to coronary atherosclerosis. Previous study suggested the possible application of connexin 43 (Cx43) and zonula occludens-1 (ZO1) immunostaining in the early diagnosis of myocardial ischemia. However, there appears to be insufficient data with regard to their mRNA levels. The present study investigated the cardiac mRNA levels of Cx43 and ZO1, using forensic autopsy materials consisting of 41 control cases without any disease or structural abnormality of the heart (group 1), 32 deaths due to acute ischemic heart disease related to coronary atherosclerosis without apparent myocardial necrosis (group 2), and 29 traumatic deaths with coronary atherosclerosis (group 3). Ten candidate reference genes were evaluated in the left ventricles of 10 forensic autopsy cases. EEF1A1, PPIA, TPT1, and RPL13A were identified as the most stable reference genes. Using these validated reference genes, mRNA levels of Cx43 and ZO1 were examined in the bilateral ventricles and atria of the heart. Relative mRNA quantification demonstrated decreased calibrated normalized relative quantity (CNRQ) values of Cx43 and ZO1 in bilateral ventricles of group 2. When using one conventional reference gene (GAPDH or ACTB) for normalization, nearly no difference was detected among the three groups. These findings indicate that ventricular gap junction remodeling may be a key contributor to rhythm disturbances. Analysis of cardiac Cx43 and ZO1 using real-time PCR is useful in diagnosis of SCD, and validation of reference genes is crucial.

Role of PUMA in methamphetamine-induced neuronal apoptosis.

Exposure to methamphetamine (METH), a widely used illicit drug, has been shown to cause neuron apoptosis. p53 upregulated modulator of apoptosis (PUMA) is a key mediator in neuronal apoptosis. This study aimed to examine the effects of PUMA in METH-induced neuronal apoptosis. We determined PUMA protein expression in PC12 cells and SH-SY5Y cells after METH exposure using western blot. We also observed the effect of METH on neuronal apoptosis after silencing PUMA expression with siRNA using TUNEL staining and flow cytometry. Additionally, to investigate possible mechanisms of METH-induced PUMA-mediated neuronal apoptosis, we measured the protein expression of apoptotic markers, including cleaved caspase-3, cleaved PARP, Bax, B-cell leukemia/lymphoma-2 (Bcl-2) and cytochrome c (cyto c), after METH treatment with or without PUMA knockdown. Results showed that METH exposure induced cell apoptosis, increased PUMA protein levels, activated caspase-3 and PARP, elevated Bax and reduced Bcl-2 expression, as well as increased the release of cyto c from mitochondria to the cytoplasm in both PC12 and SH-SY5Y cells. All these effects were attenuated or reversed after silencing PUMA. A schematic depicting the role of PUMA in METH-induced mitochondrial apoptotic pathway was proposed. Our results suggest that PUMA plays an important role in METH-triggered apoptosis and it may be a potential target for ameliorating neuronal injury and apoptosis caused by METH.

Insulin-like growth factor binding protein 5 (IGFBP5) mediates methamphetamine-induced dopaminergic neuron apoptosis.

Overexposure to methamphetamine (METH), a psychoactive drug, induces a variety of adverse effects to the nervous system, including apoptosis of dopaminergic neurons. Insulin-like growth factor binding protein 5 (IGFBP5), a member of insulin-like growth factor (IGF) system, is a pro-apoptotic factor that plays important roles in neuronal apoptosis. To test the hypothesis that IGFBP5 can mediate METH-induced neuronal apoptosis, we examined IGFBP5 mRNA and protein expression changes in PC12 cells exposed to METH (3.0mM) for 24h and in the striatum of rats following 15 mg/kg × 8 intraperitoneal injections of METH at 12h interval. We also checked the effect on neuronal apoptosis after silencing IGFBP5 expression with TUNEL staining and flow cytometry; Western blot was used for detecting the expression of apoptotic markers active-caspase3 and PARP. To elucidate the mechanisms underlying IGFBP5-mediated neuronal apoptosis, we determined the release of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria after METH treatment with or without IGFBP5 knockdown. Our results showed that IGFBP5 expression was increased significantly after METH exposure in PC12 cells and in the METH-treated rats' striatum. Further, METH-exposed PC12 cells exhibited higher apoptosis-positive cell number and activity of caspase3 and PARP compared with control cells, while these changes can be blocked by silencing IGFBP5 expression. In addition, a significant increase of cyto c release from mitochondria after METH exposure was observed and it was inhibited after silencing IGFBP5 expression in PC12 cells. These results indicate that IGFBP5 plays key roles in METH-induced neuronal apoptosis and may be a potential gene target for therapeutics in METH-caused neurotoxicity.

Inhibition of ROCK2 expression protects against methamphetamine-induced neurotoxicity in PC12 cells.

Methamphetamine is a type of psychoactive drug. It is well known that neurotoxicity caused by Methamphetamine(METH) can damage the nervous system and lead to apoptosis and cell loss of dopaminergic neurons. ROCK2 is a prominent target for gene therapy because its inhibition has proved to have a protective effect in various cell lines and pathophysiological conditions. Although several of the negative effects of METH on the dopaminergic system have been studied, the protective molecular mechanisms and the effective treatment of METH-induced apoptosis remain to be clarified. We hypothesized that ROCK2 is involved in METH-induced apoptosis. We tested our hypothesis using RT-PCR and western blotting to analyze whether silencing of ROCK2 with small interfering RNA (siROCK2) could reduce damage and apoptosis in PC12 cells after METH exposure. Increases in viability and cytomorphological changes were detected by MTT assay and bright field microscopy after pretreatment of METH-treated PC12 cells with 100 nM siROCK2. Apoptosis decreased significantly after ROCK2 silencing, as shown by Annexin V and TUNEL staining. The results show that ROCK2 is a possible gene target for therapeutics in METH-induced neurotoxicity in vitro, providing a foundation for future in vivo research.

Spatial distribution of organochlorine pesticides (OCPs) and effect of soil characters: a case study of a pesticide producing factory.

The distribution and concentration of some organochlorine pesticides (OCPs) in the soil around a pesticide factory in Zibo, China, were examined, including dichlorodiphenyltrichloroethane (DDT) and its metabolites, isomers of hexachlorocyclohexane (HCH) and endosulfan (ENDO). The results showed that the OCPs concentrations were extraordinary high in this region. The concentrations of DDTs, HCHs, and ENDO were measured in the range of 0.775-226.711, 0.248-42.838, and 0.081-1.644 mg kg(-1), respectively. DDT and its isomers were identified to be the dominate contaminants in most of the sampling sites. In the vertical direction, the distribution pattern of the total OCPs was in order of DDTs, HCHs, and ENDO in the 0-20 cm, but in 20-40 and 40-60 cm the trends were unobvious. Although no recent input occurred in most areas, the residues of OCPs remained in deep soil due to their persistence. Unlike ENDO, DDTs and HCHs appeared to have the similar property in terms of not only the migration pattern in soil, but also the relationship to the same dominant impact factor (i.e. organic matter). DDTs and HCHs were affected positively by the organic matter, whereas ENDO was affected negatively. Due to the interrelationship among various impact factors, the spatial distribution of pesticides in the soil was considered to be a combined result.