A pH-triggered N-oxide polyzwitterionic nano-drug loaded system for the anti-tumor immunity activation research.

Triple negative breast cancer (TNBC) has the characteristics of low immune cell infiltration, high expression of tumor programmed death ligand 1 (PD-L1), and abundant cancer stem cells. Systemic toxicity of traditional chemotherapy drugs due to poor drug selectivity, and chemotherapy failure due to tumor drug resistance and other problems, so it is particularly important to find new cancer treatment strategies for TNBC with limited treatment options. Both the anti-tumor natural drugs curcumin and ginsenoside Rg3 can exert anti-tumor effects by inducing immunogenic cell death (ICD) of tumor cells, reducing PD-L1 expression, and reducing cancer stem cells. However, they have the disadvantages of poor water solubility, low bioavailability, and weak anti-tumor effect of single agents. We used vinyl ether bonds to link curcumin (Cur) with N-O type zwitterionic polymers and at the same time encapsulated ginsenoside Rg3 to obtain hyperbranched zwitterionic drug-loaded micelles OPDEA-PGED-5HA@Cur@Rg3 (PPH@CR) with pH response. In vitro cell experiments and in vivo animal experiments have proved that PPH@CR could not only promote the maturation of dendritic cells (DCs) and increase the CD4+ T cells and CD8+ T cells by inducing ICD in tumor cells but also reduce the expression of PD-L1 in tumor tissues, and reduce cancer stem cells and showed better anti-tumor effects and good biological safety compared with free double drugs, which is a promising cancer treatment strategy.

Pillararene-Based Stimuli-Responsive Supramolecular Delivery Systems for Cancer Therapy.

Cancer poses a significant challenge to global public health, seriously threatening human health and life. Although various therapeutic strategies, such as chemotherapy (CT), radiotherapy, phototherapy, and starvation therapy, are applied to cancer treatment, their limited therapeutic effect, severe side effects, and unsatisfactory drug release behavior need to be carefully considered. Thus, there is an urgent need to develop efficient drug delivery strategies for improving cancer treatment efficacy and realizing on-demand drug delivery. Notably, pillararenes, as an emerging class of supramolecular macrocycles, possess unique properties of highly tunable structures, superior host-guest chemistry, facile modification, and good biocompatibility, which are widely used in cancer therapy to achieve controllable drug release and reduce the toxic side effects on normal tissues under various internal/external stimuli conditions. This review summarizes the recent advance of stimuli-responsive supramolecular delivery systems (SDSs) based on pillararenes for tumor therapy from the perspectives of different assembly methods and hybrid materials, including molecular-scale SDSs, supramolecular nano self-assembly delivery systems, and nanohybrid SDSs. Moreover, the prospects and critical challenges of stimuli-responsive SDSs based on pillararenes for cancer therapy are also discussed.

Stromal cells in the tumor microenvironment: accomplices of tumor progression?

The tumor microenvironment (TME) is made up of cells and extracellular matrix (non-cellular component), and cellular components include cancer cells and non-malignant cells such as immune cells and stromal cells. These three types of cells establish complex signals in the body and further influence tumor genesis, development, metastasis and participate in resistance to anti-tumor therapy. It has attracted scholars to study immune cells in TME due to the significant efficacy of immune checkpoint inhibitors (ICI) and chimeric antigen receptor T (CAR-T) in solid tumors and hematologic tumors. After more than 10 years of efforts, the role of immune cells in TME and the strategy of treating tumors based on immune cells have developed rapidly. Moreover, ICI have been recommended by guidelines as first- or second-line treatment strategies in a variety of tumors. At the same time, stromal cells is another major class of cellular components in TME, which also play a very important role in tumor metabolism, growth, metastasis, immune evasion and treatment resistance. Stromal cells can be recruited from neighboring non-cancerous host stromal cells and can also be formed by transdifferentiation from stromal cells to stromal cells or from tumor cells to stromal cells. Moreover, they participate in tumor genesis, development and drug resistance by secreting various factors and exosomes, participating in tumor angiogenesis and tumor metabolism, regulating the immune response in TME and extracellular matrix. However, with the deepening understanding of stromal cells, people found that stromal cells not only have the effect of promoting tumor but also can inhibit tumor in some cases. In this review, we will introduce the origin of stromal cells in TME as well as the role and specific mechanism of stromal cells in tumorigenesis and tumor development and strategies for treatment of tumors based on stromal cells. We will focus on tumor-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), tumor-associated adipocytes (CAAs), tumor endothelial cells (TECs) and pericytes (PCs) in stromal cells.

Case report: The clinical utility of metagenomic next-generation sequencing in mucormycosis diagnosis caused by fatal Lichtheimia ramosa infection in pediatric neuroblastoma.

Lichtheimia ramosa (L. ramosa) is an opportunistic fungal pathogen of the order Mucorales that may result in a rare but serious mucormycosis infection. Mucormycosis could be angioinvasive, causing thrombosis and necrosis in the nose, brain, digestive tract, and respiratory tract. The infection is highly lethal, especially in immunocompromised hosts, and the incidence has been on the rise. However, due to its relatively low incidence in pediatric population and the challenges with diagnosis, the awareness and management experience for pediatric mucormycosis are extremely limited, which might lead to poor outcomes. In this study, we comprehensively reviewed the course of a fatal rhinocerebral mucormycosis case in a pediatric neuroblastoma patient receiving chemotherapy. Due to a lack of awareness of the infection, the standard care of amphotericin B treatment was delayed and not administered until the identification of L. ramosa by metagenomic next-generation sequencing (mNGS)-based pan-pathogen detection of the patient's peripheral blood sample. We also reviewed the literature on L. ramosa infection cases reported worldwide between 2010 and 2022, with an analysis of clinical manifestation, prognosis, and epidemiological data. Our study not only highlighted the clinical value of comprehensive mNGS in rapid pathogen detection but also raised awareness of recognizing lethal fungal infection early in immunocompromised hosts including pediatric cancer patients.

Occupational health effect of TCE exposure: Experiment evidence of gene-environment interaction in hypersensitivity reaction.

BACKGROUND: Recently, Trichloroethylene (TCE) induced TCE hypersensitivity syndrome (THS) has attracted the attention of many researchers in the field of environmental and occupational health. Studies have revealed that Human leukocyte antigen (HLA) polymorphisms were the important genetic determinants of the diseases, but the potential molecular mechanism remains unclear. OBJECTIVE: This study aimed to investigate the association between THS and HLA at the molecular level. METHOD: We chose the human B-lymphoblastoid cell line Hmy2.C1R transfected with cDNA of HLA-B*13:01 and HLA-B*13:02 to analyze the characteristics of HLA-B-binding peptides and investigate the effect of TCE on the binding affinity of peptides to the HLA-B molecules. Further, the mathematical model was used to identify the possible interaction between TCE and HLA-B*13:01 or HLA-B*13:02 molecule. RESULTS: 54 HLA-B*13:01-binding peptides and 85 HLA-B*13:02-binding peptides were identified. Comparing the protein sequences of HLA-B*13:01 and HLA-B*13:02, amino acids were different at positions 94, 95 and 97. The results of the binding affinity of self-peptides to HLA molecules in the presence of TCE showed that TCE significantly decreased the binding affinity of peptides to HLA-B*13:01 only, but did not affect that of HLA-B*13:02. Molecular docking model showed that there was a unique high-affinity binding mode between TCE and HLA-B*13:01 (but not HLA-B*13:02), and the binding site located in the region of F pocket, suggesting that the unique structure of the F pocket of HLA-B*13:01 might provide the possibility of binding TCE. The pathogenesis of interaction between HLA-B*13:01 and TCE might belong to the model of the alteration of the HLA-presented self-peptide repertoire. DISCUSSION: This study explored the molecular mechanism of the association between THS and HLA-B*13:01, and had important implications for understanding the role of gene-environment interaction in the development of complex environment-related diseases.

Therapeutic strategies for gastric cancer targeting immune cells: Future directions.

Gastric cancer (GC) is a malignancy with a high incidence and mortality, and the emergence of immunotherapy has brought survival benefits to GC patients. Compared with traditional therapy, immunotherapy has the advantages of durable response, long-term survival benefits, and lower toxicity. Therefore, targeted immune cells are the most promising therapeutic strategy in the field of oncology. In this review, we introduce the role and significance of each immune cell in the tumor microenvironment of GC and summarize the current landscape of immunotherapy in GC, which includes immune checkpoint inhibitors, adoptive cell therapy (ACT), dendritic cell (DC) vaccines, reduction of M2 tumor-associated macrophages (M2 TAMs), N2 tumor-associated neutrophils (N2 TANs), myeloid-derived suppressor cells (MDSCs), effector regulatory T cells (eTregs), and regulatory B cells (Bregs) in the tumor microenvironment and reprogram TAMs and TANs into tumor killer cells. The most widely used immunotherapy strategies are the immune checkpoint inhibitor programmed cell death 1/programmed death-ligand 1 (PD-1/PD-L1) antibody, cytotoxic T lymphocyte-associated protein 4 (CTLA-4) antibody, and chimeric antigen receptor T (CAR-T) in ACT, and these therapeutic strategies have significant anti-tumor efficacy in solid tumors and hematological tumors. Targeting other immune cells provides a new direction for the immunotherapy of GC despite the relatively weak clinical data, which have been confirmed to restore or enhance anti-tumor immune function in preclinical studies and some treatment strategies have entered the clinical trial stage, and it is expected that more and more effective immune cell-based therapeutic methods will be developed and applied.

Trend Analysis of Occupational Lung Cancer from Coke Oven Emission Exposure - China, 2008-2019.

What is already known about this topic?: Coke oven emissions are a complex mixture of particulate matter and gases, some with carcinogenicity, released during coke production. Lung cancer caused by coke oven emissions has been listed as a statutory occupational cancer in China and many countries. What is added by this report?: In this study, coke oven emissions-induced lung cancer was mainly found in the manufacturing industries. Coke oven workers exposed to higher levels of polycyclic aromatic hydrocarbons in different workplaces had a high risk of occupational lung cancer. What are the implications for public health practice?: It is necessary to take efforts to greatly reduce emissions from coke production and effectively monitor the health of workers.

Shear stress and ROS-responsive biomimetic micelles for atherosclerosis via ROS consumption.

Reactive oxygen species (ROS) are well-known important initiating factors required for atherosclerosis formation, which leads to endothelial dysfunction and plaque formation. Most of the existing antithrombotic therapies use ROS-responsive drug delivery systems, which have a certain therapeutic effect but cannot eliminate excess ROS. Therefore, the atherosclerosis cannot be treated from the source. Moreover, nanoparticles are easily cleared by the immune system during blood circulation, which is not conducive to long-term circulation. In this study, we developed an intelligent response system that could simultaneously respond to ROS and the shear stress microenvironment of atherosclerotic plaques. This system was formed by red blood cells (RBCs) and simvastatin-loaded micelles (SV MC). The micelles consisted of poly(glycidyl methacrylate)-polypropylene sulfide (PGED-PPS). The hydrophobic PPS could react with excess ROS to become hydrophilic, which forced the micelle rupture, resulting in drug release. Most importantly, PPS could also significantly deplete the ROS level, realizing the synergistic treatment of atherosclerosis with drugs and materials. The positively charged SV MC and negatively charged RBCs were self-assembled through electrostatic adsorption to obtain SV MC@RBCs. The SV MC@RBCs could respond to the high shear stress at the atherosclerotic plaque, and the shear stress induced SV MC desorption from the RBC surface. Using biomimetic methods to evade the SV MC@RBCs elimination by the immune system and to reduce the ROS plays a vital role in improving atherosclerosis treatment. The results of in vitro and in vivo experiments showed that SV MC@RBCs could effectively treat atherosclerosis. Moreover, not only does the SV MC@RBCs system avoid the risk of bleeding, but it also has excellent in vivo safety. The study results indicate that the SV MC@RBCs system is a promising therapeutic nanomedicine for treating ROS-related diseases.

Utility evaluation of HLA-B*13:01 screening in preventing trichloroethylene-induced hypersensitivity syndrome in a prospective cohort study.

OBJECTIVES: Trichloroethylene (TCE) -induced hypersensitivity syndrome (TIHS) is a potentially life-threatening disease. Several genetic susceptibility biomarkers have been found to be associated with TIHS, and this systematic prospective study has been conducted to evaluate the utility of these genetic susceptibility biomarkers in preventing the disease. METHODS: The newly hired TCE-exposed workers were recruited from March 2009 to October 2010. HLA-B*13:01 genotyping and 3-month follow-up procedure were conducted. All workers were monitored for adverse reaction by telephone interview every week. The workers with early symptoms of TIHS were asked to go to the hospital immediately for further examination, diagnosis and treatment. The medical expense record data of patients with TIHS were collected for cost-effectiveness analysis in 2018. RESULTS: Among 1651 workers, 158 (9.57%) were found to carry the HLA-B*13:01 allele and 16 (0.97%) were diagnosed with TIHS. HLA-B*13:01 allele was significantly associated with an increased TIHS risk (relative risk=28.4, 95% CI 9.2 to 86.8). As a risk predictor of TIHS, HLA-B*13:01 testing had a sensitivity of 75%, a specificity of 91.1% and an area under curve of 0.83 (95% CI 0.705 to 0.955), the positive and negative predictive values were 7.6% and 99.7%, respectively. The incidence of TIHS was significantly decreased in HLA-B*13:01 non-carriers (0.27%) compared with all workers (0.97%, p=0.014). Cost-effectiveness analysis showed that HLA-B*13:01 screening could produce an economic saving of $4604 per TIHS avoided. CONCLUSIONS: Prospective HLA-B*13:01 screening may significantly reduce the incidence of TIHS and could be a cost effective option for preventing the disease in TCE-exposed workers.

Study on preparation and controlled release in vitro of bergenin-amino polylactic acid polymer.

The efficacy of traditional tablets, drop pills and soft capsules of bergenin is far lower than expected. Therefore, bergenin was modified in this paper to connect with amino polylactic acid, a kind of biodegradable material, for chemical immobilization. The bergenin-amino PLA thus obtained was controllable with small molecular weight and excellent thermal stability. Its release in vitro could be extended with the increase in molecular weight. According to tests of biological compatibility and anti-tumor in vitro, bergenin-amino PLA at a proportion of 1 to 100 was characterized by better biological compatibility and lower cytotoxicity than control group at a concentration of 0.4 µ g/m L. The chemical immobilization of bergenin not only provides patients with an excellent way of drug administration but lays a good foundation for sustained drug release.

Exposure characterization and estimation of benchmark dose for cancer biomarkers in an occupational cohort of diesel engine testers.

Exposure to diesel engine exhaust (DEE) was associated with various adverse health effects including lung cancer. Particle size distribution and profiles of organic compounds in both particle and gas phases of DEE that could provide valuable insights into related health effects were measured in a diesel engine testing workshop. Concentrations of urinary 6 mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in 137 DEE-exposed workers and 127 non-DEE-exposed workers were determined. Benchmark dose method was applied to estimate lower limit of benchmark dose (BMDL) of urinary OH-PAHs most specific to DEE exposure for previously reported cancer biomarkers. We found that 84.3% of diesel exhaust particles were ultrafine particles. Indeno[123-cd]pyrene and phenanthrene were the most abundant carcinogenic and noncarcinogenic PAHs in the particle phase of DEE, respectively. Principal component analysis demonstrated that urinary hydroxyphenanthrene (OHPhe) had highest loading value on principal component (PC) representative of DEE exposure and lowest loading value on PC representative of smoking status. BMDLs of urinary OHPhe from best-fitting models for cancer biomarkers including micronucleus and 1,N6-ethenodeoxyadenosine were 1.08 µg/g creatinine and 2.82 µg/g creatinine, respectively. These results provided basis for understanding DEE exposure induced health effects and potential threshold for regulating DEE levels in an occupational setting.

Preparation of bergenin - Poly (lactic acid) polymers and in vitro controlled release studies.

The efficacy of bergenin prepared with osmotic-pump-controlled release is much lower than expected. In this study, biodegradable polylactic acid is used to modify bergenin and immobilize it with chemical methods. Bergenin-PLA obtained by this method has low molecular weight and good thermal stability, as well as prolonged in vitro release time along with increased molecular weight. Biocompatibility tests and in vitro antitumor tests showed that bergenin-PLA at a ratio of 1:30 has good biological properties and low cytotoxicity at t three concentrations, and its antitumor activity was significantly increased compared to bergenin. The chemical immobilization of bergenin not only provides a good mode of administration for patients but also provides a good foundation for the sustained release of drugs over time.

Local and Systemic Inflammation May Mediate Diesel Engine Exhaust-Induced Lung Function Impairment in a Chinese Occupational Cohort.

Diesel exhaust (DE) as the major source of vehicle-emitted particle matter in ambient air impairs lung function. The objectives were to assess the contribution of local (eg, the fraction of exhaled nitric oxide [FeNO] and serum Club cell secretory protein [CC16]) and systemic (eg, serum C-reaction protein [CRP] and interleukin-6 [IL-6]) inflammation to DE-induced lung function impairment using a unique cohort of diesel engine testers (DETs, n = 137) and non-DETs (n = 127), made up of current and noncurrent smokers. Urinary metabolites, FeNO, serum markers, and spirometry were assessed. A 19% reduction in CC16 and a 94% increase in CRP were identified in DETs compared with non-DETs (all p values <10-4), which were further corroborated by showing a dose-response relationship with internal dose for DE exposure (all p values <.04) and a time-course relationship with DE exposure history (all p values <.005). Mediation analysis showed that 43% of the difference in FEV1 between DETs and non-DETs can be explained by circulating CC16 and CRP (permuted p < .001). An inverse dose-dependent relationship between FeNO and internal dose for cigarette smoke was identified (p = .0003). A range of 95% lower bounds of benchmark dose of 1.0261-1.4513 µg phenanthrols/g creatinine in urine as an internal dose was recommended for regulatory risk assessment. Local and systemic inflammation may be key processes that contribute to the subsequent development of obstructive lung disease in DE-exposed populations.

Occupational exposure to diesel engine exhaust and serum cytokine levels.

The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response using data from a cross-sectional molecular epidemiology study of 41 diesel engine testing workers and 46 unexposed controls. Repeated personal exposure measurements of PM2.5 and other DEE constituents were taken for the diesel engine testing workers before blood collection. Serum levels of six inflammatory biomarkers including interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1ß, and monocyte chemotactic protein (MCP)-1 were analyzed in all subjects. Compared to unexposed controls, concentrations of MIP-1ß were significantly reduced by ∼37% in DEE exposed workers (P < 0.001) and showed a strong decreasing trend with increasing PM2.5 concentrations in all subjects (Ptrend < 0.001) as well as in exposed subjects only (Ptrend = 0.001). Levels of IL-8 and MIP-1ß were significantly lower in workers in the highest exposure tertile of PM2.5 (>397 µg/m3 ) compared to unexposed controls. Further, significant inverse exposure-response relationships for IL-8 and MCP-1 were also found in relation to increasing PM2.5 levels among the DEE exposed workers. Given that IL-8, MIP-1ß, and MCP-1 are chemokines that play important roles in recruitment of immunocompetent cells for immune defense and tumor cell clearance, the observed lower levels of these markers with increasing PM2.5 exposure may provide insight into the mechanism by which DEE promotes lung cancer. Environ. Mol. Mutagen. 59:144-150, 2018. © 2017 Wiley Periodicals, Inc.

Effects of occupational exposure to carbon black on peripheral white blood cell counts and lymphocyte subsets.

The International Agency for Research on Cancer has classified carbon black (CB) as a possible (Group 2B) human carcinogen. Given that most CB manufacturing processes result in the emission of various types of chemicals, it is uncertain if the adverse health effects that have been observed in CB-exposed workers are related to CB specifically or are due to other exposures. To address this issue, we conducted a cross-sectional molecular epidemiology study in China of 106 male factory workers who were occupationally exposed to pure CB and 112 unexposed male workers frequency-matched by age and smoking status from the same geographic region. Repeated personal exposure measurements were taken in workers before biological sample collection. Peripheral blood from all workers was used for the complete blood cell count and lymphocyte subsets analysis. Compared to unexposed workers, eosinophil counts in workers exposed to CB were increased by 30.8% (P = 0.07) after adjusting for potential confounders. When stratified by smoking status, statistically significant differences in eosinophils between CB exposed and unexposed workers were only present among never smokers (P = 0.040). Smoking is associated with alterations in various cell counts; however, no significant interaction between CB exposure and smoking status for any cell counts was observed. Given that inflammation, characterized in part by elevated eosinophils in peripheral blood, may be associated with increased cancer risk, our findings provide new biologic insights into the potential relationship between CB exposure and lung carcinogenesis. Environ. Mol. Mutagen. 57:589-604, 2016. © 2016 Wiley Periodicals, Inc.

Increased levels of urinary biomarkers of lipid peroxidation products among workers occupationally exposed to diesel engine exhaust.

Diesel engine exhaust (DEE) was found to induce lipid peroxidation (LPO) in animal exposure studies. LPO is a class of oxidative stress and can be reflected by detecting the levels of its production, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and etheno-DNA adducts including 1,N(6)-etheno-2'-deoxyadenosine (ɛdA) and 3,N(4)-etheno-2'-deoxycytidine (ɛdC). However, the impact of DEE exposure on LPO has not been explored in humans. In this study, we evaluated urinary MDA, 4-HNE, ɛdA, and ɛdC levels as biomarkers of LPO among 108 workers with exclusive exposure to DEE and 109 non-DEE-exposed workers. Results showed that increased levels of urinary MDA and ɛdA were observed in subjects occupationally exposed to DEE before and after age, body mass index (BMI), smoking status, and alcohol use were adjusted (all p < 0.001). There was a statistically significant relationship between the internal exposure dose (urinary ΣOH-PAHs) and MDA, 4-HNE, and ɛdA (all p < 0.001). Furthermore, significant increased relations between urinary etheno-DNA adduct and MDA, 4-HNE were observed (all p < 0.05). The findings of this study suggested that the level of LPO products (MDA and ɛdA) was increased in DEE-exposed workers, and urinary MDA and ɛdA might be feasible biomarkers for DEE exposure. LPO induced DNA damage might be involved and further motivated the genomic instability could be one of the pathogeneses of cancer induced by DEE-exposure. However, additional investigations should be performed to understand these observations.

Long-term exposure to diesel engine exhaust affects cytokine expression among occupational population.

Diesel engine exhaust (DEE) is a predominant contributor to urban air pollution. The International Agency for Research on Cancer classified DEE as a group I carcinogen. Inflammatory response is considered to be associated with various health outcomes including carcinogenesis. However, human data linking inflammation with long-term DEE exposure are still lacking. In this study, a total of 137 diesel engine testing workers with an average exposure of 8.2 years and 108 unexposed controls were enrolled. Peripheral blood samples were collected from all subjects, and the association of DEE exposure with inflammatory biomarkers was analyzed. Overall, DEE exposed workers had a significant increase in the C-reactive protein (CRP) and a significant decrease in cytokines including interleukin (IL)-1ß, IL-6, IL-8, and macrophage inflammatory protein (MIP)-1ß compared to controls after adjusting for age, BMI, smoking status, and alcohol use, and findings were highly consistent when stratified by smoking status. In addition, exposure time dependent patterns for IL-6 and CRP were also found (Ptrend = 0.006 and 0.026, respectively); however, the levels of IL-1ß and MIP-1ß were significantly lower in subjects with a DEE working time of less than 10 years compared with the controls and then recovered to control levels in workers exposed for >10 years. There were no significant differences in blood cell counts and major lymphocyte subsets between exposed workers and the controls. Our results provide epidemiological evidence for the relationship between DEE exposure and immunotoxicity considering the important roles of cytokines in immunological processes.

Reduced pulmonary function and increased pro-inflammatory cytokines in nanoscale carbon black-exposed workers.

BACKGROUND: Although major concerns exist regarding the potential consequences of human exposures to nanoscale carbon black (CB) particles, limited human toxicological data is currently available. The purpose of this study was to evaluate if nanoscale CB particles could be responsible, at least partially, for the altered lung function and inflammation observed in CB workers exposed to nanoscale CB particles. METHODS: Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Brunauer-Emmett-Teller were used to characterize CB. Eighty-one CB-exposed male workers and 104 non-exposed male workers were recruited. The pulmonary function test was performed and pro-inflammatory cytokines were evaluated. To further assess the deposition and pulmonary damage induced by CB nanoparticles, male BALB/c mice were exposed to CB for 6 hours per day for 7 or 14 days. The deposition of CB and the pathological changes of the lung tissue in mice were evaluated by paraffin sections and TEM. The cytokines levels in serum and lung tissue of mice were evaluated by ELISA and immunohistochemical staining (IHC). RESULTS: SEM and TEM images showed that the CB particles were 30 to 50 nm in size. In the CB workplace, the concentration of CB was 14.90 mg/m³. Among these CB particles, 50.77% were less than 0.523 micrometer, and 99.55% were less than 2.5 micrometer in aerodynamic diameter. The reduction of lung function parameters including FEV1%, FEV/FVC, MMF%, and PEF% in CB workers was observed, and the IL-1ß, IL-6, IL-8, MIP-1beta, and TNF- alpha had 2.86-, 6.85-, 1.49-, 3.35-, and 4.87-folds increase in serum of CB workers, respectively. In mice exposed to the aerosol CB, particles were deposited in the lung. The alveolar wall thickened and a large amount of inflammatory cells were observed in lung tissues after CB exposure. IL-6 and IL-8 levels were increased in both serum and lung homogenate. CONCLUSIONS: The data strongly suggests that nanoscale CB particles could be responsible for the lung function reduction and pro-inflammatory cytokines secretion in CB workers. These results, therefore, provide the first evidence of a link between human exposure to CB and long-term pulmonary effects.

NuRD blocks reprogramming of mouse somatic cells into pluripotent stem cells.

Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) by overexpression of a defined set of transcription factors requires epigenetic changes in pluripotency genes. Nuclear reprogramming is an inefficient process and the molecular mechanisms that reset the epigenetic state during iPSC generation are largely unknown. Here, we show that downregulation of the nucleosome remodeling and deacetylation (NuRD) complex is required for efficient reprogramming. Overexpression of Mbd3, a subunit of NuRD, inhibits induction of iPSCs by establishing heterochromatic features and silencing embryonic stem cell-specific marker genes, including Oct4 and Nanog. Depletion of Mbd3, on the other hand, improves reprogramming efficiency and facilitates the formation of pluripotent stem cells that are capable of generating viable chimeric mice, even in the absence of c-Myc or Sox2. The results establish Mbd3/NuRD as an important epigenetic regulator that restricts the expression of key pluripotency genes, suggesting that drug-induced downregulation of Mbd3/NuRD may be a powerful means to improve the efficiency and fidelity of reprogramming.

Identification and characterization of Bmi-1-responding element within the human p16 promoter.

Bmi-1, the first functionally identified polycomb gene family member, plays critical roles in cell cycle regulation, cell immortalization, and cell senescence. Bmi-1 is involved in the development and progression of carcinomas and is a potent target for cancer therapy. One important pathway regulated by Bmi-1 is that involving two cyclin-dependent kinase inhibitors, p16(Ink4a) and p19(Arf), as Bmi-1 represses the INK4a locus on which they are encoded. A close correlation between the up-regulation of Bmi-1 and down-regulation of p16 has been demonstrated in various tumors; however, how Bmi-1 regulates p16 expression is not clear. In this study, we revealed that Bmi-1 regulates the expression of p16 by binding directly to the Bmi-1-responding element (BRE) within the p16 promoter. The BRE resided at bp -821 to -732 upstream of the p16 ATG codon. BRE alone was sufficient to allow Bmi-1-mediated regulation of the CMV promoter. Bmi-1 typically functions by forming a complex with Ring2; however, regulation of p16 was independent of Ring2. Chromatin immunoprecipitation sequencing of Bmi-1-precipitated chromatin DNA revealed that 1536 genes were targeted by Bmi-1, including genes involved in tissue-specific differentiation, cell cycle, and apoptosis. By analyzing the binding sequences of these genes, we found two highly conserved Bmi-1-binding motifs, which were required for Bmi-1-mediated p16 promoter regulation. Taken together, our results revealed the molecular mechanism of Bmi-1-mediated regulation of the p16 gene, thus providing further insights into the functions of Bmi-1 as well as a sensitive high-throughput platform with which to screen Bmi-1-targeted small molecules for cancer therapy.