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1.
J Nanobiotechnology ; 21(1): 355, 2023 Sep 30.
Article in English | MEDLINE | ID: mdl-37775799

ABSTRACT

BACKGROUND: In recent years, the development of BMSCs-derived exosomes (EXO) for the treatment of osteosarcoma (OS) is a safe and promising modality for OS treatment, which can effectively deliver drugs to tumor cells in vivo. However, the differences in the drugs carried, and the binding of EXOs to other organs limit their therapeutic efficacy. Therefore, improving the OS-targeting ability of BMSCs EXOs and developing new drugs is crucial for the clinical application of targeted therapy for OS. RESULTS: In this study, we constructed a potential therapeutic nano platform by modifying BMSCs EXOs using the bone-targeting peptide SDSSD and encapsulated capreomycin (CAP) within a shell. These constructed nanoparticles (NPs) showed the ability of homologous targeting and bone-targeting exosomes (BT-EXO) significantly promotes cellular endocytosis in vitro and tumor accumulation in vivo. Furthermore, our results revealed that the constructed NPs induced ferroptosis in OS cells by prompting excessive accumulation of reactive oxygen species (ROS), Fe2+ aggregation, and lipid peroxidation and further identified the potential anticancer molecular mechanism of ferroptosis as transduced by the Keap1/Nrf2/GPX4 signaling pathway. Also, these constructed NP-directed ferroptosis showed significant inhibition of tumor growth in vivo with no significant side effects. CONCLUSION: These results suggest that these constructed NPs have superior anticancer activity in mouse models of OS in vitro and in vivo, providing a new and promising strategy for combining ferroptosis-based chemotherapy with targeted therapy for OS.


Subject(s)
Bone Neoplasms , Exosomes , Ferroptosis , Nanoparticles , Osteosarcoma , Animals , Mice , NF-E2-Related Factor 2 , Kelch-Like ECH-Associated Protein 1 , Signal Transduction , Osteosarcoma/drug therapy , Bone Neoplasms/drug therapy
2.
Trop Med Infect Dis ; 8(7)2023 Jun 29.
Article in English | MEDLINE | ID: mdl-37505640

ABSTRACT

Schistosomiasis (Schistosomiasis japonica) remains an important public health problem in China, and the Chinese government has set an ambitious goal of eliminating schistosomiasis by 2030. Based on the observational study of the Global Burden of Disease Study database in 2019 (GBD2019) and the World Bank database, this study aimed to analyze the prevalence trend of schistosomiasis in China from 1990 to 2019 by using the joinpoint regression model, and the relationship between economic and social development and schistosomiasis prevalence. The data of age-standardized infection rates (ASRs) from the Global Burden of Disease Study Global Health Data Exchange were collected, and Gross national product per capita (GDP) and people using safely managed sanitation services ((PPMS) % of population) were extracted from the World Bank database. Trends of ASR were analyzed using joinpoint regression analysis, the association of ASR with GDP, and PPMS using the Pearson correlation analysis. The results reveal that, from 1990 to 2019, the overall trend of ASR from schistosomiasis showed a decrease for both sexes, the decreases in men were relatively smaller compared with women. A larger decrease has been observed in the age groups from 15 to 49 years compared with other age groups. The ASR of schistosomiasis had a significant negative correlation with GDP and PPMS. This observational study identified decreasing prevalence rate of schistosomiasis in China since 1990. Continuous investment, optimization of control strategy, and economic development will help to achieve the goal of schistosomiasis elimination.

3.
Trop Med Infect Dis ; 8(5)2023 Apr 30.
Article in English | MEDLINE | ID: mdl-37235307

ABSTRACT

Flooding is the main natural factor in snail diffusion, and it has a negative impact on schistosomiasis transmission. There are few studies on the spread and migration of snails following a flood; therefore, we aimed to investigate the influence of flooding on snail diffusion and explore the characteristics and laws of snail diffusion in Jiangxi Province. By using a retrospective survey and cross-sectional survey, the data on snail spreading in Jiangxi Province from 2017 to 2021 were collected. The distribution, nature, and area of snail spread were systematically analyzed in combination with the hydrological situation, types of region, and types of flood. From 2017 to 2021, a total of 120 snail-spread environments were found, including in 92 hilly areas and in 28 lake areas. The areas caused by flood and by other means numbered 6 and 114, respectively. The proportions of recurrence, expansion, and first-time occurrences were 43.42%, 38.16%, and 18.42%, respectively, and the 14 new snail environments were only distributed in the hilly areas. With the exception of 2018, the ratio of snail-spread areas in the hilly region was higher than that in lake region in other years. The average density of live snails was 0.0184-1.6617 no./0.1 m2 and 0.0028-0.2182 no./0.1 m2 in the hilly region. Among the 114 environments affected by floods, 86 consisted of hilly environments, including 66 spreading environments affected by rainstorm floods, and 20 rainstorm debris flow environments. There were 28 lake areas, of which 10 were in the Jiangxi section of Yangtze River and were affected by rainstorm floods. Snail spread following flooding has a certain 'lag effect,' and = simple annual changes in hydrological characteristics have little effect on the diffusion of snails or on their density = in the affected environment, but it is more closely related to local floods. The hilly environments are more susceptible to floods than the lake region, and the risk of snail spread is much higher in the hilly than in the lake region.

4.
Int J Nanomedicine ; 17: 5431-5446, 2022.
Article in English | MEDLINE | ID: mdl-36426375

ABSTRACT

Purpose: To investigate induction of cell death in Osteosarcoma (OS) using the anti-tuberculosis drug, rifampicin, loaded into exosomes. Patients and Methods: BMSC-exosomes were isolated by ultracentrifugation and loaded ultrasonically with rifampicin. Nanoparticle exosome-rifampicin (EXO-RIF) was added to the OS cell-lines, 143B and MG63, in vitro, to observe the growth inhibitory effect. In vivo experiments were conducted by injecting fluorescently labeled EXO-RIF through the tail vein of 143B cell xenograft nude mice and tracking distribution. Therapeutic and toxic side-effects were analyzed systemically. Results: Sonication resulted in encapsulation of rifampicin into exosomes. Exosome treatment accelerated the entry of rifampicin into OS cells and enhanced the actions of rifampicin in inhibiting OS proliferation, migration and invasion. Cell cycle arrest at the G2/M phase was observed. Dynamin-related protein 1 (Drp1) was activated by EXO-RIF and caused mitochondrial lysis and apoptosis. Exosome treatment targeted rifampicin to the site of OS, causing OS apoptosis and improving mouse survival in vivo. Conclusion: The potent Drp1 agonist, rifampicin, induced OS apoptosis and exosome loading, improving OS targeting and mouse survival rates. EXO-RIF is a promising strategy for the treatment of diverse malignancies.


Subject(s)
Bone Neoplasms , Exosomes , Nanoparticles , Osteosarcoma , Humans , Animals , Mice , Rifampin , Mice, Nude , Dynamins , Osteosarcoma/drug therapy , Apoptosis , Bone Neoplasms/drug therapy
5.
Front Pharmacol ; 13: 803880, 2022.
Article in English | MEDLINE | ID: mdl-35496311

ABSTRACT

Osteoporosis is a serious public health problem that results in fragility fractures, especially in postmenopausal women. Because the current therapeutic strategy for osteoporosis has various side effects, a safer and more effective treatment is worth exploring. It is important to examine natural plant extracts during new drug design due to low toxicity. Mogrol is an aglycon of mogroside, which is the active component of Siraitia grosvenorii (Swingle) and exhibits anti-inflammatory, anticancer and neuroprotective effects. Here, we demonstrated that mogrol dose-dependently inhibited osteoclast formation and function. To confirm the mechanism, RNA sequencing (RNA-seq), real-time PCR (RT-PCR), immunofluorescence and Western blotting were performed. The RNA-seq data revealed that mogrol had an effect on genes involved in osteoclastogenesis. Furthermore, RT-PCR indicated that mogrol suppressed osteoclastogenesis-related gene expression, including CTSK, ACP5, MMP9 and DC-STAMP, in RANKL-induced bone marrow macrophages Western blotting demonstrated that mogrol suppressed osteoclast formation by blocking TNF receptor-associated factor 6 (TRAF6)-dependent activation of the mitogen-activated protein kinase nuclear factor-B (NF-κB) signaling pathway, which decreased two vital downstream transcription factors, the nuclear factor of activated T cells calcineurin-dependent 1 (NFATc1) and c-Fos proteins expression. Furthermore, mogrol dramatically reduced bone mass loss in postmenopausal mice. In conclusion, these data showed that mogrol may be a promising procedure for osteoporosis prevention or therapy.

6.
Tissue Cell ; 76: 101759, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35219069

ABSTRACT

MiR-361-3p has been reported in several types of human cancer. However, the expression profile and biological functions of miR-361-3p in osteosarcoma remain uncovered. The expression profiles of miR-361-3p in osteosarcoma tissues and cell lines were evaluated using RT-qPCR. In 88 osteosarcoma patients, survival analysis was performed using Kaplan-Meier curves; while prognostic significance of miR-361-3p was analyzed using Cox regression analysis. The effects of miR-361-3p on cell proliferation, migration and invasion capacities were analyzed using CCK-8 and transwell assays. The target genes of miR-361-3p were assessed using luciferase reporter assay, RT-qPCR, Western blot and rescue experiments. Xenograft assay was conducted to test tumor growth ability. MiR-361-3p was found to be upregulated in human osteosarcoma tissues and cell lines. The expression of miR-361-3p was observed to be closely associated with TNM stage and lung metastasis. High expression of miR-361-3p was found to be capable of predicting poor clinical prognosis in osteosarcoma patients. Whilst overexpression of miR-361-3p was demonstrated to promote the proliferation, migration and invasion of osteosarcoma cells; knockdown of miR-361-3p was shown to exhibit an opposite inhibitory effect. Bioinformatics analysis and luciferase reporter assays confirmed that ARID3A is a direct target of miR-361-3p. Functional assays demonstrated that osteosarcoma cell proliferation, migration and invasion were promoted by miR-361-3p via negative regulation of ARID3A. Finally, overexpression of ARID3A was shown to partially reverse the tumor-promoting effect of miR-361-3p. Besides, in vivo assays revealed that miR-361-3p overexpression facilitated tumor growth in nude mice. In conclusion, this study indicates that miR-361-3p is a crucial prognostic biomarker of osteosarcoma, and that targeting of miR-361-3p/ARID3A axis may be a promising strategy in osteosarcoma therapy.


Subject(s)
Bone Neoplasms , DNA-Binding Proteins , MicroRNAs , Osteosarcoma , Transcription Factors , Animals , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Carcinogenesis , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Heterografts , Humans , Mice , Mice, Nude , MicroRNAs/genetics , MicroRNAs/metabolism , Osteosarcoma/genetics , Osteosarcoma/metabolism , Osteosarcoma/pathology , Transcription Factors/genetics , Transcription Factors/metabolism
7.
Curr Med Sci ; 41(4): 777-781, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34403103

ABSTRACT

OBJECTIVE: Supracondylar humerus fractures are the most frequent fractures of the paediatric elbow. The present study introduced a modified surgical procedure for treatment of supracondylar humerus fractures in children. METHODS: From February 2015 to August 2019, 73 patients with Gartland's type II and III supracondylar fractures were treated with this modified method. Totally, 68 of all patients were followed up for 3-12 months (mean 8.25 months). The evaluation results included fracture nonunion, ulnar nerve injury, pin track infection, carrying angle and elbow joint Flynn score. RESULTS: The results showed that bone union was observed in all children, one case had an iatrogenic ulnar nerve injury, and the symptoms were completely relieved in 4 months after removing of the medial-side pin. All children had no cubitus varus deformity and no pin track infection, and the rate of satisfactory results according to Flynn's criteria score was 100%. CONCLUSION: The modified closed reduction and Kirschner wires internal fixation could effectively reduce the rate of open reduction, the risk of iatrogenic ulnar nerve injury, and the incidence of cubitus varus deformity in treatment of supracondylar humerus fractures in children.


Subject(s)
Fracture Fixation, Internal/methods , Humeral Fractures/surgery , Humerus/surgery , Plastic Surgery Procedures , Bone Wires , Child , Child, Preschool , Female , Humans , Humeral Fractures/physiopathology , Humerus/physiopathology , Male , Pediatrics
8.
Am J Chin Med ; 49(5): 1251-1274, 2021.
Article in English | MEDLINE | ID: mdl-34107857

ABSTRACT

Neohesperidin has anti-oxidative and anti-inflammatory properties and exerts extensive therapeutic effects on various cancers. In this study, the osteosarcoma cell lines were exposed to different concentrations of neohesperidin. Cell proliferation and viability were assessed by CCK-8 and colony-formation assays. The role of neohesperidin in cell cycle progression and apoptosis were analyzed by flow cytometry and western blotting. To identify autophagosomes and autolysosomes, we used a tandem GFP-mRFP-LC3B lentiviral construct. In addition, autophagy was evaluated by examining autophagosome formation using transmission electron microscopy. Intracellular reactive oxygen species (ROS) production was detected by fluorescence microscopy and flow cytometry. Subsequently, the activation of the ROS/JNK signaling pathway was investigated. Neohesperidin could inhibit proliferation and induce apoptosis in SJSA and HOS cells. The formation of autophagosomes indicated that autophagy occurred in neohesperidin-treated cells and the apoptotic effect of neohesperidin was significantly increased after the use of autophagy inhibitors. Subsequently, we found that neohesperidin-induced apoptosis and autophagy were related to the increase in ROS generation and were significantly inhibited by GSH. Moreover, neohesperidin induced activation of the c-Jun N-terminal kinase (JNK) signaling pathway and inhibition of JNK with SP600125 attenuated neohesperidin-induced apoptosis and autophagy simultaneously. Our data indicated that neohesperidin caused G2/M phase arrest and induced apoptosis and autophagy by activating the ROS/JNK pathway in human osteosarcoma cells, suggesting that neohesperidin is a potential drug candidate for the treatment of osteosarcomas.


Subject(s)
Apoptosis/drug effects , Autophagy/drug effects , Cell Cycle Checkpoints/drug effects , Hesperidin/analogs & derivatives , MAP Kinase Signaling System/drug effects , Osteosarcoma/drug therapy , Reactive Oxygen Species/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Hesperidin/pharmacology , Humans
9.
Drug Des Devel Ther ; 14: 5077-5085, 2020.
Article in English | MEDLINE | ID: mdl-33239866

ABSTRACT

PURPOSE: The long-term survival rate of osteosarcoma, which is the most common type of primary malignant bone tumor, has stagnated in past decades. Acacetin is a natural flavonoid compound that has antioxidative and anti-inflammatory effects and exhibits extensive therapeutic effects on various cancers. In this study, the anticancer potential of acacetin and the underlying molecular mechanisms were examined in human osteosarcoma cells (SJSA and HOS). MATERIALS AND METHODS: HOS and SJSA cell lines were exposed to different concentrations of acacetin. Cell proliferation and viability were assessed by CCK-8 and colony-formation assays. Hoechst 33258 fluorescent staining was employed to detect apoptosis. Cell apoptosis was measured by an annexin V-FITC/PI assay by flow cytometry. The alteration in the mitochondrial membrane potential was detected by a JC-1 Assay Kit. Apoptosis-related protein expression was determined by Western blotting. Intracellular reactive oxygen species (ROS) production was detected by fluorescence microscopy and flow cytometry. Subsequently, the activation of the ROS/JNK signaling pathway was investigated. RESULTS: Acacetin could inhibit proliferation and induce apoptosis in SJSA and HOS cells. The acacetin treatment resulted in the activation of caspase-3, -8, and -9 and cleaved PARP. Further studies showed that acacetin-induced apoptosis was attributed to ROS. In addition, we found that acacetin induced the activation of the downstream c-Jun N-terminal kinase (JNK) signaling pathway. Subsequently, after treatment with the ROS scavenger GSH and the JNK inhibitor SP600125, the apoptosis-inducing effect triggered by acacetin was significantly attenuated. CONCLUSION: The results of the present study indicate that acacetin may induce apoptosis to inhibit cell growth by activating the ROS/JNK signaling pathway in SJSA and HOS cells, suggesting that acacetin may be a promising candidate for the management of osteosarcomas.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Bone Neoplasms/drug therapy , Flavones/pharmacology , Osteosarcoma/drug therapy , Anthracenes/pharmacology , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors , JNK Mitogen-Activated Protein Kinases/metabolism , Osteosarcoma/metabolism , Osteosarcoma/pathology , Reactive Oxygen Species/antagonists & inhibitors , Reactive Oxygen Species/metabolism
10.
Medicine (Baltimore) ; 99(40): e21433, 2020 Oct 02.
Article in English | MEDLINE | ID: mdl-33019381

ABSTRACT

INTRODUCTION: Intradural schwannomas can occur at any level of the spine. According to the literature, approximately 8% of intradural schwannomas occur in the atlantoaxial spine, and these tumors are usually located in the posterolateral or lateral spinal cord. In contrast, tumors in the ventral midline of the spinal cord are relatively rare. PATIENT CONCERNS: A 47-year-old female presented with progressively worsening neck pain and paresthesias in both upper and lower limbs for the past 5 years. DIAGNOSIS: Based on Magnetic Resonance Imaging and histopathological findings, she was diagnosed with ventral midline primary schwannoma of the cervical spinal cord. INTERVENTIONS: The patient was treated with surgical resection. OUTCOMES: Follow-up visit at 2 years after the surgery showed that the patient is neurologically intact and free of disease. CONLUSION: In summary, for the tumors in the ventral midline of the atlantoaxial spinal cord, the preferred treatment is complete surgical resection by the posterior approach compared to the anterior approach, which often improves clinical symptoms or achieves a healing effect.


Subject(s)
Neurilemmoma/pathology , Spinal Cord Neoplasms/pathology , Cervical Cord/diagnostic imaging , Cervical Cord/pathology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neck Pain/etiology , Neurilemmoma/diagnosis , Neurilemmoma/surgery , Spinal Cord Neoplasms/diagnostic imaging , Spinal Cord Neoplasms/surgery
11.
Medicine (Baltimore) ; 99(43): e22792, 2020 Oct 23.
Article in English | MEDLINE | ID: mdl-33120796

ABSTRACT

RATIONALE: We report a case of Schmorl node induced multiple radiculopathy. PATIENT CONCERNS: A 70-year-old female patient complained of lower back pain in the left leg accompanied by numbness and weakness. DIAGNOSIS: Radiographs showed obvious osteoporosis in the lumbar vertebrae. Computed tomography demonstrated a hole in the upper posterior half of the L2 vertebral body. Magnetic resonance imaging of the lumbar spine revealed a herniated disc involving a protrusion at the posterior wall of the L2 vertebral body, which was present in the left lateral and dorsal epidural spaces. There was significant lumbar stenosis at the L2 vertebral body secondary to dural sac compression due to the mass. INTERVENTION: Left-sided hemilaminectomy was performed at L2 with screw fixation at L1-3. Intraoperatively, the severely ruptured disc compression in the dural sac and nerve root was removed. OUTCOMES: The patient's leg pain was immediately resolved, and her back pain was reduced. The patient recovered normal motor function at 20 days after surgery. LESSONS: A Schmorl node can progress and break through the lumbar vertebral body, resulting in nerve compression. A large proximal herniated mass can cause distal multiple radiculopathy. Therefore, this special case of Schmorl node with multiple radiculopathy should be treated by removing the proximal herniated nucleus pulposus from the vertebral body.


Subject(s)
Intervertebral Disc Displacement/complications , Lumbar Vertebrae/pathology , Radiculopathy/etiology , Aged , Constriction, Pathologic , Female , Humans , Intervertebral Disc Displacement/surgery , Laminectomy/methods , Low Back Pain , Lumbar Vertebrae/surgery , Osteoporosis/complications
12.
Ecotoxicol Environ Saf ; 202: 110900, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32593095

ABSTRACT

Heavy metals such as lead (Pb), cadmium (Cd), and mercury (Hg) are representative neurotoxicological contaminants that can evoke cognitive dysfunctions. Low levels of these contaminants can be detected simultaneously in the human blood. In our previous study, behavioral performances were markedly impaired by exposure to these heavy metal mixtures (MM) at low levels. However, the aspects of cognitive functions involved are not well understood. Here, we further analyzed search strategies using a new algorithm named Morris water maze-unbiased strategy classification (MUST-C). Rat pups were co-exposed to low doses of Pb, Cd, and Hg during the embryonic and lactation stage. MM exposure at low doses, similar to those found in the general population, impaired search strategies even though their latency and path length were not affected in the Morris water maze task. MM-exposed rats preferred to use more directionless repetition strategies and less target orientation strategies than did vehicle-exposed animals in a dose-dependent manner. In addition, thionine staining and electron microscopy further revealed that MM exposure induced dose-dependent search strategy related place cell injures in the hippocampal CA1 and CA3 regions. These results demonstrate that the use of suboptimal search strategies underlies the early cognitive deficits in rats exposed to low doses of MM. The current study determined that search strategy analysis might be a novel sensitive assessment method for evaluating in the neurobehavioral toxicity.


Subject(s)
Cognitive Dysfunction/chemically induced , Environmental Pollutants/toxicity , Metals, Heavy/toxicity , Animals , Cadmium/toxicity , Cognition , Female , Hippocampus , Humans , Juvenile Hormones , Lactation , Male , Mercury/toxicity , Rats
13.
Aging (Albany NY) ; 12(7): 6172-6190, 2020 04 08.
Article in English | MEDLINE | ID: mdl-32269179

ABSTRACT

Long noncoding RNAs (lncRNAs) have been certified as important regulators in tumorigenesis. LncRNA GAS6-AS2 (GAS6-AS2) was a newly identified tumor-related lncRNA, and its dysregulation and oncogenic effects in melanoma and bladder cancer had been reported in previous studies. However, the expression pattern and potential function of GAS6-AS2 in osteosarcoma (OS) have not been investigated. In this study, we identified a novel OS-related lncRNA GAS6-AS2. We found that GAS6-AS2 was distinctly upregulated in both OS specimens and cell lines. Distinct up-regulation of GAS6-AS2 in OS was correlated with advanced clinical stages and shorter survivals. In addition, USF1 could directly bind to the GAS6-AS2 promoter and contribute to its overexpression. Furthermore, GAS6-AS2 knockdown caused tumor suppressive effects via reducing cellular proliferation, migration and invasion, and promoting OS cell apoptosis. Besides, GAS6-AS2 directly bound to miR-934 and downregulated its expression. Mechanistically, GAS6-AS2 positively regulated the expression of BCAT1 through sponging miR-934. Taken together, our data illustrated how GAS6-AS2 played an oncogenic role in OS and might offer a potential therapeutic target for treating OS.


Subject(s)
Intercellular Signaling Peptides and Proteins/metabolism , MicroRNAs/metabolism , Osteosarcoma , RNA, Long Noncoding/metabolism , Upstream Stimulatory Factors/metabolism , Carcinogenesis/genetics , Cell Line, Tumor , Disease Progression , Gene Expression Regulation, Neoplastic , Humans , Osteosarcoma/genetics , Osteosarcoma/pathology , Transaminases/metabolism , Transcriptional Activation , Up-Regulation
14.
Toxicology ; 411: 101-109, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30445054

ABSTRACT

A large number of studies have evidenced that developmental neurotoxicity induced by lead (Pb) is related to oxidative injury. Furthermore, recent studies have found that developmental Pb exposure can induce neurodegeneration in old age. Because of the common presence of Pb in the environment, humans are exposed to this metal throughout their lifetime. However, few studies have explored the changes in lifespan profiles of neurotoxicity, as well as oxidative stress following lifetime Pb exposure. In the present study, rats were exposed to lead acetate from their embryonic stage to old age. Dynamic changes in neurodegeneration, oxidative stress, and endoplasmic reticulum (ER) stress in the brains at postnatal week 3 (PNW3, weaning), 41 weeks (PNW41, adulthood) and 70 weeks (PNW70, old age) were investigated. Pb exposure resulted in neurodegeneration with decreased neuronal densities and brain volumes in PNW3 and PNW70 rats; however, no significant changes occurred in PNW41 rats based on thionine stain analysis and magnetic resonance imaging (MRI) scans. Expression of the ER stress protein glucose-regulated protein 78 (GRP78) increased in Pb-exposed rats, which was associated with high levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in rat brains after Pb exposure in PNW3 and PNW70 rats. Our findings suggested that lifetime Pb exposure induced neurodegenerative injuries that began to occur in infancy, were relieved in adulthood, but intensified in old age. The critical periods for prevention or intervention in neurodegenerative diseases induced by Pb exposure occurred in early life.


Subject(s)
Brain/pathology , Lead Poisoning, Nervous System/pathology , Neurodegenerative Diseases/chemically induced , Neurodegenerative Diseases/pathology , Oxidative Stress/drug effects , 8-Hydroxy-2'-Deoxyguanosine , Aging , Animals , Brain/diagnostic imaging , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/metabolism , Endoplasmic Reticulum Chaperone BiP , Endoplasmic Reticulum Stress/drug effects , Female , Gene Expression Regulation/drug effects , Lead/blood , Lead/metabolism , Lead Poisoning, Nervous System/diagnostic imaging , Magnetic Resonance Imaging , Male , Neurodegenerative Diseases/diagnostic imaging , Neurons/pathology , Pregnancy , Prenatal Exposure Delayed Effects/pathology , Rats , Rats, Sprague-Dawley
15.
Ecotoxicol Environ Saf ; 163: 674-684, 2018 Nov 15.
Article in English | MEDLINE | ID: mdl-30099283

ABSTRACT

Lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) are among the leading toxic agents detected in the environment, and they have also been detected simultaneously in blood, serum, and urine samples of the general population. Meanwhile early neurologic effects and multiple interactions of Pb, Cd, As, and Hg had been found in children from environmentally polluted area. However, the current studies of these four metals were mostly limited to the interactions between any two metals, whereas the interaction characteristics between any three and four metals were rarely studied. In our study, we firstly explored the characteristics of the neurotoxic interactions among these four elements in nerve cells with factorial designs. The results showed that Pb+Cd+As+Hg co-exposure had a synergistic neurotoxic effect that was more severe than that induced by any two or three metals, when their individual metals were at human environmental exposure (in the blood of U.S. population) relevant levels and below no observed adverse effect levels (NOAELs). Therefore, Pb+Cd+As+Hg co-exposure at human environmental exposure relevant levels were further selected to examine synaptic homeostasis as the cellular and molecular foundation of learning and memory. We reported for the first time that Pb+Cd+As+Hg co-exposure induced dose-dependent decreases of the dendritic lengths and branching, as well as spine density and mature phenotype in primary hippocampal neurons, and the stimulated neurite outgrowths in NGF-differentiated PC12 cells. And the above synaptic homeostasis disruption was associated with serum induced kinase (Snk)-spine associated Rap GTPase activating protein (SPAR) pathway. Our study suggests that human environmental Pb, Cd, As, and Hg co-exposure has the potential to evoke synergistic neurotoxicity even if their individual metals are below NOAELs, which reinforces the need to control and regulate potential sources of metal contamination.


Subject(s)
Arsenic/toxicity , Cadmium/toxicity , Lead/toxicity , Mercury/toxicity , Synapses/drug effects , Animals , Cell Line , Cell Survival/drug effects , Dendrites/drug effects , Environmental Exposure , Hippocampus , Homeostasis/drug effects , Humans , Neurons/drug effects , Neurotoxicity Syndromes/pathology , Rats
16.
Int J Biol Sci ; 11(7): 803-12, 2015.
Article in English | MEDLINE | ID: mdl-26078722

ABSTRACT

Osteosarcoma is a bone cancer that develops commonly in children and adolescents. However, osteosarcoma treatments often fail by the development of chemoresistance to apoptosis, and the molecular mechanisms remain unclear. In this study, we propose that autophagy is responsible for osteosarcomatous resistance to apoptosis. We implicate PERK-mediated autophagy as a significant contributor to apoptosis resistance due to ER stress in osteosarcoma cells. By immunostainings and western blots, we identified that PERK activated osteosarcomatous autophagy via inhibiting mTORC1 pathway, thereby preventing cell apoptosis. While using RNAi, we knocked down PERK and found that autophagy was suppressed, result in osteosarcomatous apoptosis. Our results identify a novel role of PERK-mediated autophagy as a significant mechanism for osteosarcoma cell survival. These results will help to understand the mechanism of chemoresistance in osteosarcoma cells, and indicate a novel target for improving osteosarcoma therapy.


Subject(s)
Apoptosis/physiology , Autophagy/physiology , Endoplasmic Reticulum Stress/physiology , Osteosarcoma/metabolism , eIF-2 Kinase/metabolism , Analysis of Variance , Blotting, Western , Cell Line, Tumor , DNA Primers/genetics , Humans , Mechanistic Target of Rapamycin Complex 1 , Multiprotein Complexes/metabolism , Osteosarcoma/physiopathology , RNA Interference , Real-Time Polymerase Chain Reaction , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , eIF-2 Kinase/pharmacology
17.
ScientificWorldJournal ; 2014: 873525, 2014.
Article in English | MEDLINE | ID: mdl-24711740

ABSTRACT

The onset of lipid peroxidation within cellular membranes is associated with changes in their physiochemical properties and enzymatic dysfunction of the membrane environment. There are increasing bodies of evidence indicating that aldehydic molecules generated endogenously during the process of lipid peroxidation are causally involved in most of the pathophysiological effects associated with oxidative stress in cells and tissues. 4-Hydroxy-2-nonenal (4-HNE), among them, is believed to be largely responsible for cytopathological effects observed during oxidative stress in vivo and has achieved the status of one of the best recognized and most studied of the cytotoxic products of lipid peroxidation. Here, we reported that 4-HNE treatment may induce cell death in MG63 human osteosarcoma cells. The 4-HNE treatment could activate caspase-3 and alter the Bax/Bcl-2 apoptotic signaling. All these changes are due to the inhibition of AKT activity by 4-HNE treatment, and we also found that the p70S6K activity, downstream factors of AKT, was also blocked by 4-HNE. Our results revealed the molecular mechanism of how 4-HNE induces cell death in MG63 human osteosarcoma cells, which contributes to the clinical treatment of cancer therapy.


Subject(s)
Aldehydes/pharmacology , Apoptosis/drug effects , Bone Neoplasms/metabolism , Osteosarcoma/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Antineoplastic Agents/pharmacology , Caspase 3/metabolism , Cell Death/drug effects , Cell Line, Tumor , Cysteine Proteinase Inhibitors/pharmacology , Humans , Proto-Oncogene Proteins c-bcl-2/metabolism , bcl-2-Associated X Protein/metabolism
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