Outdoor Light at Night, Air Pollution, and Risk of Cerebrovascular Disease: A Cohort Study in China.

BACKGROUND: We sought to explore the associations of outdoor light at night (LAN) and air pollution with the risk of cerebrovascular disease (CeVD). METHODS: We included a total of 28 302 participants enrolled in Ningbo, China from 2015 to 2018. Outdoor LAN and air pollution were assessed by Satellite-derived images and land-use regression models. CeVD cases were confirmed by medical records and death certificates and further subdivided into ischemic and hemorrhagic stroke. Cox proportional hazard models were used to estimate hazard ratios and 95% CIs. RESULTS: A total of 1278 CeVD cases (including 777 ischemic and 133 hemorrhagic stroke cases) were identified during 127 877 person-years of follow-up. In the single-exposure models, the hazard ratios for CeVD were 1.17 (95% CI, 1.06-1.29) for outdoor LAN, 1.25 (1.12-1.39) for particulate matter with an aerodynamic diameter ≤2.5 µm, 1.14 (1.06-1.22) for particulate matter with aerodynamic diameter ≤10 µm, and 1.21 (1.06-1.38) for NO2 in every interquartile range increase. The results were similar for ischemic stroke, whereas no association was observed for hemorrhagic stroke. In the multiple-exposure models, the associations of outdoor LAN and PM with CeVD persisted but not for ischemic stroke. Furthermore, no interaction was observed between outdoor LAN and air pollution. CONCLUSIONS: Levels of exposure to outdoor LAN and air pollution were positively associated with the risk of CeVD. Furthermore, the detrimental effects of outdoor LAN and air pollution might be mutually independent.

Stability analysis of pumped storage hydropower plant in abandoned open-pit mine affected by dynamic surface subsidence of combined mining.

The construction of a pumped storage hydropower plant (PSHP) in an abandoned open-pit mine is a potential alternative to green mining and energy storage, which can increase the utilization rate of renewable energy and develop residual resources of abandoned mines. Dynamic surface subsidence affected by combined underground and open-pit mining (CUOPM) seriously affects the construction and operation of the PSHP and is one of the critical scientific issues that needs to be solved immediately. The stability of the PSHP was analyzed and treatment scheme of the goafs was proposed based on on-site measurement, theoretical analysis, and numerical simulation. First, the distribution of goafs in the Haizhou open-pit mining area was investigated and surface subsidence value was obtained using InSAR technology and ground monitoring. Secondly, the surface subsidence mechanism affected by CUOPM is analyzed and indicates the subsidence maximum values and scope of influence are greater than those of single underground mining. A dynamic surface subsidence prediction model for combined mining is established based on the Knothe time function model. Thirdly, based on the CVISC model, the numerical calculation models were established by using FLAC3D, and the characteristics and laws of surface subsidence in different periods of CUOPM were studied. The comparative analysis of the observation results shows that the proposed model and numerical simulation calculation method have excellent applicability and accuracy. Finally, a stability evaluation method of PSHP was established, and the results of the evaluation show that the affected areas are the semi-ground powerhouse (SGPH) and the west side of the lower reservoir. The method of grouting filling was used to treat the goafs, and the results showed that it effectively alleviates the dynamic surface subsidence affected by CUOPM, and provides a safety guarantee for PSHP.

Association between visit-to-visit lipid variability and risk of ischemic heart disease: a cohort study in China.

AIMS: To explore the associations between visit-to-visit lipid variability and risk of ischemic heart disease (IHD) in a population-based cohort in China. METHODS: We evaluated lipid variability in 30,217 individuals from the Yinzhou Health Information System who had ≥3 recorded lipid measurements during 2010-2014. We used various indicators including standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV) to quantify the variability in triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Overall, a total of 1305 participants with IHD were identified during the follow-up of 194,421 person-years. Subjects in Q4 had a 21% elevated risk of IHD (HR = 1.21, 95% CI: 1.03-1.41) for LDL-C variability (CV) compared with the reference (Q1). The HRs for Q4 vs Q1 were 1.21 (95% CI: 1.04-1.42) for HDL-C variability, and 1.28 (95% CI: 1.10-1.50) for TC variability. However, no association was observed between triglycerides variability and risk of IHD. CONCLUSIONS: Higher variability in LDL-C, HDL-C, and TC levels was associated with an elevated risk of IHD, suggesting that lipid variability could be considered as an independent risk factor of IHD.

Age at diagnosis modifies associations of type 2 diabetes with cancer incidence and mortality: a retrospective matched-cohort study.

AIMS/HYPOTHESIS: The age-specific associations between type 2 diabetes and cancer risk are not fully understood. The aim of this study was to assess how age at diagnosis modifies the associations between type 2 diabetes and cancer risk. METHODS: We used data from the Yinzhou Health Information System, and included 42,279 individuals who were newly diagnosed with type 2 diabetes between 2010 and 2014, as well as 166,010 age- and sex-matched control individuals without diabetes who were selected randomly from the electronic health records of the entire population. Patients were divided into four age groups according to age at diagnosis: <50, 50-59, 60-69 and ≥70 years. Stratified Cox proportional hazards regression models, with age as the time scale, were used to estimate the HRs and 95% CIs for the associations of type 2 diabetes with the risks of overall and site-specific cancers. Population-attributable fractions were also calculated for outcomes associated with type 2 diabetes. RESULTS: During median follow-up periods of 9.20 and 9.32 years, we identified 15,729 incident cancer cases and 5383 cancer deaths, respectively. Patients diagnosed with type 2 diabetes before 50 years of age had the highest relative risks of cancer incidence and mortality, with HRs (95% CI) of 1.35 (1.20, 1.52) for overall cancer incidence, 1.39 (1.11, 1.73) for gastrointestinal cancer incidence, 2.02 (1.50, 2.71) for overall cancer mortality, and 2.82 (1.91, 4.18) for gastrointestinal cancer mortality. Risk estimates decreased gradually with each decade increase in diagnostic age. The population-attributable fractions for overall cancer and gastrointestinal cancer mortality also decreased with increasing age. CONCLUSIONS/INTERPRETATION: The associations of type 2 diabetes with cancer incidence and mortality varied by age at diagnosis, with a higher relative risk among patients who were diagnosed at a younger age.

Estimation of cancer mortality attributable to excess body weight during 2006-2015 in China.

BACKGROUND: Cancer is one of the most common causes of death. Excess body weight (EBW), a risk factor for cancer, is highly prevalent in China. We aimed to estimate the number and proportion of cancer deaths attributed to EBW and their changes during 2006-2015 in China. METHODS: Population attributable fractions in 2006, 2010, and 2015 were calculated with 1) prevalence of overweight/obesity, exacted from the China Health and Nutrition Survey conducted in 8-9 provinces of China in 1997, 2000, and 2004; 2) relative risks for EBW and site-specific cancers, obtained from previous studies; 3) data on cancer deaths in 2006, 2010, and 2015, originated from the Chinese Cancer Registry Annual Report. RESULTS: In 2015, EBW contributed to 45,918 (3.1% of all) cancer deaths in China, with 24,978 (2.6%) in men and 20,940 (3.8%) in women. By region, the fraction of cancer deaths attributable to EBW ranged from 1.6% (West) to 4.1% (Northeast). Cancers of liver, stomach, and colorectum were the main EBW-attributable cancers. The fractions of cancer deaths attributable to EBW were 2.4% (95%CI: 0.8-4.2%) in 2006, 2.9% (95%CI: 1.0-5.2%) in 2010, and 3.1% (95%CI: 1.0-5.4%) in 2015, respectively, and increased for all gender, region, and cancer site during 2006-2015. CONCLUSIONS: The proportion of cancer deaths attributed to EBW was higher in women and Northeastern China, with an upward trend in the recent decade. A combination of comprehensive and individualized measures is necessary to reduce the prevalence of EBW and related cancer burden in China.

Association of walkability and NO2 with metabolic syndrome: A cohort study in China.

BACKGROUND: Epidemiological studies have reported an association between traffic-related pollution with risk of metabolic syndrome (MetS). However, evidence from prospective studies on the association of walkability and nitrogen dioxide (NO2) with MetS is still scarce. We, therefore, aimed to evaluate the association of long-term exposure to NO2 and walkability with hazards of incident MetS. METHODS: A total of 17,965 participants without MetS diagnosed within one year at baseline were included in our study from a population-based prospective cohort in Yinzhou District, Ningbo, Zhejiang Province, China. Participants were followed up by the regional Health Information System (HIS) until December 15, 2021. MetS was defined based on the criteria of Chinese Diabetes Society (CDS2004). We used walkscore tools, calculating with amenity categories and decay functions, and spatial-temporal land-use regression (LUR) models to estimate walkability and NO2 concentrations. We used Cox proportional hazards regression models to examine the association of walkability and NO2 with hazards of MetS incidence reporting with hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Overall, we followed up 77,303 person-years and identified 4040 incident cases of MetS in the entire cohort. Higher walkability was inversely associated with incident MetS (HR = 0.94, 95 % CI: 0.91-0.99), whereas NO2 was positively associated with MetS incidence (HR = 1.07, 95 %CI: 1.00-1.15) per interquartile range increment in two-exposure models. Furthermore, we found a significant multiplicative interaction between walkability and NO2. Stronger associations were observed for NO2 and incident MetS among men, smokers, drinkers and participants who aged < 60 years and had higher levels of income. CONCLUSION: In summary, we found living in areas with lower walkability and higher concentrations of NO2 were associated with increased incidence of MetS. The beneficial effect of higher walkability may be attenuated by exposure to NO2.

Baseline and longitudinal trajectories of body-mass index and all-cause mortality among patients with type 2 diabetes.

AIM: To investigate the associations of baseline body mass index (BMI) and longitudinal BMI trajectories with all-cause mortality among patients with type 2 diabetes mellitus (T2DM). METHODS,: We used data from the diabetes surveillance system of Yinzhou Health Information System with T2DM patients registered from 2010 to 2015. Participants aged ≥ 40 years were included and were followed up until September 30, 2021. The latent class growth mixture model was used to identify different changing patterns in BMI for 5 years from registration. Cox proportional hazards models were used to examine the associations of baseline BMI and 5-year BMI trajectories with all-cause mortality. RESULTS: We observed a nonlinear association between baseline BMI and all-cause mortality (P for nonlinearity < 0.001), with an increased risk of death for low but not high BMI. However, compared with participants with medium-stable BMI for 5 years from baseline, individuals with increasing BMI had higher mortality, with adjusted hazard ratios (95% confidence intervals) 1.21 (1.02;1.43) for early-increasing and 1.47 (1.19;1.80) for late-sharp increasing groups. CONCLUSION: These findings suggest that while obesity itself may not be associated with an increased risk for mortality, weight gain, and in particular rapid weight gain, is a risk factor for mortality among patients with T2DM.

Association of walkability and fine particulate matter with chronic obstructive pulmonary disease: A cohort study in China.

BACKGROUND: Walkability has been considered to be associated with metabolic and cardiovascular diseases, but the relationship between walkability and chronic obstructive pulmonary disease (COPD) remains unclear. Moreover, fine particulate matter (PM2.5), possibly positively correlated to walkability, may lead to an increased risk of COPD. The separate and joint effects of PM2.5 and walkability on risk of COPD were explored in our study. METHODS: We used prospective data of 29,572 participants from the Yinzhou cohort in Ningbo, China. COPD cases were diagnosed based on the Yinzhou Health Information System (YHIS). Walkability was measured using walk score in relation to the built environment based on geographic information systems (GIS). Air pollution levels were assessed by fitting land use regression (LUR) models. Cox proportional hazards models were used to evaluate the relationships of PM2.5 and walkability with COPD. Furthermore, we also examined additive and multiplicative interactions between walkability and PM2.5. RESULTS: Overall, a total of 29,572 participants were included in the final analysis and 722 COPD incident cases were identified during 134,846 person-years of follow-up. Compared with subjects with lower walkability, individuals with higher walkability had a decreased risk of COPD (HR = 0.88, 95 % CI: 0.82-0.95) for every IQR increase. By contrast, exposure to PM2.5 (every IQR increase) was associated with an elevated risk of COPD (HR = 1.21, 95 % CI: 1.06-1.37). No interaction between PM2.5 and walkability was observed. CONCLUSIONS: Living in a highly walkable neighborhood could decrease risk of COPD, whereas high levels of PM2.5 were positively associated with COPD. In addition, the beneficial effects of walkability were not attenuated by exposure to PM2.5.

Associations of Diet Quality and Heavy Metals with Obesity in Adults: A Cross-Sectional Study from National Health and Nutrition Examination Survey (NHANES).

A poor diet cannot fully explain the prevalence of obesity. Other environmental factors (e.g., heavy metals) have been reported to be associated with obesity. However, limited evidence is available for the combined effect of these factors on obesity. Therefore, we conducted a cross-sectional study and used the data from the National Health and Examination Survey (2007−2018) to explore the associations between diet quality and heavy metals and obesity. Diet quality was evaluated by the Healthy Eating Index-2015 (HEI-2015) score. Heavy metals included serum cadmium (Cd), lead (Pb), and mercury (Hg). We included 15,959 adults, with 5799 of obesity (body mass index ≥ 30 kg/m2). After adjustment for covariates, every interquartile range increase in HEI-2015 scores, Pb, Cd and Hg was associated with a 35% (odds ratios [OR] = 0.65, 95% confidence interval [CI]: 0.60, 0.70), 11% (OR = 0.89, 95% CI: 0.82, 0.98), 9% (OR = 0.91, 95% CI: 0.87, 0.96), 5% (OR = 0.85, 95% CI: 0.82, 0.89) reduction in risk of peripheral obesity, respectively. In addition, the association between the HEI-2015 scores and peripheral obesity was attenuated by higher levels of heavy metals (All p interaction < 0.05). Results remained similar for abdominal obesity. Our study reveals the distinct effects of a high-quality diet and heavy metals on obesity prevalence, and the beneficial effect of a high-quality diet could be weakened by higher levels of heavy metals.

Long-term exposure to residential surrounding greenness and incidence of diabetes: A prospective cohort study.

Exposure to residential greenness might affect population health through increasing physical activity and social engagement, improving mental health, and reducing harmful environmental exposure. However, evidence on the association of greenness with risk of diabetes is still controversial. In this study, we recruited a total of 22,535 participants aged ≥18 years from Yinzhou District, Ningbo, Zhejiang Province, China to investigate the associations between residential greenness and risk of diabetes incidence. Residential greenness was estimated using Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Vegetation Continuous Field (VCF). We also calculated cumulative average NDVI, EVI and VCF values, and changes in NDVI, EVI and VCF during the follow-up period. We used Cox proportional hazards models controlling for demographic characteristics, lifestyles, individual socioeconomic status, history of diseases and particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5) to examine hazard ratios (HRs) and 95% confidence intervals (95% CIs) and assessed physical activity, body mass index (BMI) or PM2.5 as potential mediators. During 84,992.64 person-years of follow-up, a total of 1,154 incident cases of diabetes occurred. In multivariable models, living in the highest quartile of cumulative average NDVI, EVI and VCF within 250-m buffer was associated with 57% (HR = 0.43, 95% CI: 0.36, 0.52), 62% (HR = 0.38, 95% CI: 0.32, 0.45), and 55% (HR = 0.45, 95% CI: 0.38, 0.54) reduction in diabetes risk compared with the lowest quartile, respectively. Results remained similar for NDVI, EVI, and VCF within 500-m and 1000-m buffers. Stratified analyses showed stronger association for residential greenness and diabetes among older people. The association between greenness and diabetes did not appear to be mediated by physical activity, PM2.5 or BMI. Our findings suggested that higher residential greenness was significantly associated with lower risk of diabetes.

Residential greenness, air pollution, and incident ischemic heart disease: A prospective cohort study in China.

Greener residential surroundings are associated with beneficial health outcomes, whereas higher air pollution exposure is linked with elevated risks of chronic diseases. To date, limited studies have explored the interaction between residential greenness and air pollution on the risk of ischemic heart disease (IHD). We performed a prospective cohort study that included 29,141 adult participants recruited from Yinzhou District, Ningbo, China. Normalized Difference Vegetation Index (NDVI) around each participant's residence was calculated to measure residential greenness exposure. Land-use regression models were conducted to estimate long-term individual exposure to air pollutants, including nitrogen dioxide (NO2) and particulate matter with aerodynamic diameters ≤ 2.5 µm (PM2.5) and ≤10 µm (PM10). Cox proportional hazard models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations of residential greenness and air pollutants with the risk of incident IHD. During 101,172.5 person-years of follow-up, 1392 incident IHD cases were reported in the study population. Residential greenness, expressed as an interquartile range (IQR) increase in NDVI within 250 m, was inversely associated with incident IHD (HR = 0.89, 95%CI: 0.81,0.98). However, long-term exposures to air pollution were associated with higher IHD incidence (HR = 1.21, 95%CI:1.10,1.33 per IQR increase for PM2.5; HR = 1.12, 95%CI:1.03,1.22 per IQR increase for PM10; HR = 1.09, 95%CI:1.02,1.16 per IQR increase for NO2). Mediation analyses suggested that the beneficial effect of residential greenness on incident IHD could be partly mediated by reducing the exposure to PM2.5. These findings suggested that higher greenness was associated with decreased risk of IHD, while air pollutants were positively associated with incident IHD. Meanwhile, residential greenness may decrease the risk of IHD by reducing exposure to PM2.5.

Interaction between walkability and fine particulate matter on risk of ischemic stroke: A prospective cohort study in China.

Living in walkable neighborhoods has been reported to be associated with a lower risk of cardiovascular disease. Features of walkable neighborhoods, however, may be related to particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5), which could increase risk of cardiovascular disease. The interaction effect between walkability and PM2.5 on risk of ischemic stroke remains to be elucidated. In this study, we recruited a total of 27,375 participants aged ≥40 years from Yinzhou District, Ningbo, Zhejiang Province, China to investigate the associations of walkability and PM2.5 with risk of ischemic stroke. We used amenity categories and decay functions to evaluate walkability and high-spatiotemporal-resolution land-use regression models to assess PM2.5 concentrations. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median follow-up of 4.08 years, we identified a total of 637 incident cases of ischemic stroke in the entire cohort. Higher walkability was associated with a lower risk of ischemic stroke (quartile, Q4 vs. Q1 walkability: HR = 0.59, 95% CI: 0.47-0.75), whereas PM2.5 was positively associated with risk of ischemic stroke (Q4 vs. Q1 PM2.5: HR = 1.70, 95% CI: 1.29-2.25). Furthermore, we observed a significant interaction between walkability and PM2.5 on risk of ischemic stroke. Walkability was inversely associated with risk of ischemic stroke at lower PM2.5 concentrations, but this association was attenuated with increasing PM2.5 concentrations. Although walkable neighborhoods appear to decrease the risk of ischemic stroke, benefits may be offset by adverse effects of PM2.5 exposure in the most polluted areas. These findings are meaningful for future neighborhood design, air pollution control, and stroke prevention.

Application of the AngioJet Ultra Thrombectomy Device for the Percutaneous Mechanical Treatment (PMT) of Iliac Limb Occlusion after Endovascular Aneurysm Repair (EVAR).

BACKGROUND: To investigate the safety and efficacy of applying the AngioJet Ultra thrombectomy device in treating endograft occlusions in the iliac arteries following endovascular aneurysm repair (EVAR). METHODS: This study utilized a retrospective analysis of 452 patients with infrarenal abdominal aortic aneurysm (AAA). Twelve of the patients experienced iliac limb occlusion during their follow-up period, and the AngioJet Ultra thrombectomy device was used in tandem with iliac angioplasty to treat these patients. The safety of the device was assessed through the amount of blood drawn, the duration of the procedure, and the occurrence of post-operative complications, while its efficacy was assessed through aortic computed tomography angiography (CTA) imaging and post-operative symptomatology results. RESULTS: All 12 patients were male, and they had a mean age of 62.8 ± 11.8 years. Iliac limb occlusion occurred on the left side of 4 patients and on the right side of 8 patients. The AngioJet Ultra thrombectomy device was used together with iliac angioplasty during surgery, with a success rate of 100%. A bifurcated endograft was successfully implanted in 9 patients following AngioJet Ultra thrombectomy and balloon dilation angioplasty, while a unibody endograft was successfully implanted in 3 patients following AngioJet Ultra thrombectomy and balloon dilation angioplasty. The mean surgery duration was 2.4 hrs, and the patients were hospitalized for an average of 4.5 days. After surgery, the patients' intermittent claudication/buttock claudication gradually vanished. Two patients experienced hemoglobinuria, with one of them developing mild renal dysfunction. Currently, the twelve patients have been followed up for an average of 12 months, and none have experienced any lower extremity ischemia. CONCLUSIONS: The use of the AngioJet Ultra thrombectomy device as a supplementary treatment for iliac limb occlusion following abdominal EVAR is safe, effective, and minimally invasive.

Humanized von Willebrand factor reduces platelet sequestration in ex vivo and in vivo xenotransplant models.

The transplantation of organs across species offers the potential to solve the shortage of human organs. While activation of human platelets by human von Willebrand factor (vWF) requires vWF activation by shear stress, contact between human platelets and porcine vWF (pvWF) leads to spontaneous platelet adhesion and activation. This non-physiologic interaction may contribute to the thrombocytopenia and coagulation pathway dysregulation often associated with xenotransplantation of pig organs in nonhuman primates. Pigs genetically modified to decrease antibody and complement-dependent rejection (GTKO.hCD46) were engineered to express humanized pvWF (h*pvWF) by replacing a pvWF gene region that encodes the glycoprotein Ib-binding site with human cDNA orthologs. This modification corrected for non-physiologic human platelet aggregation on exposure to pig plasma, while preserving in vitro platelet activation by collagen. Organs from pigs with h*pvWF demonstrated reduced platelet sequestration during lung (p ≤ .01) and liver (p ≤ .038 within 4 h) perfusion ex vivo with human blood and after pig-to-baboon lung transplantation (p ≤ .007). Residual platelet sequestration and activation were not prevented by the blockade of canonical platelet adhesion pathways. The h*pvWF modification prevents physiologically inappropriate activation of human or baboon platelets by porcine vWF, addressing one cause of the thrombocytopenia and platelet activation observed with xenotransplantation.

Effect of COVID-19 on hospital visits in Ningbo, China: an interrupted time-series analysis.

OBJECTIVE: Unprecedented rigorous public health measures were implemented during the coronavirus disease 2019 (COVID-19) epidemic, but it is still unclear how the intervention influenced hospital visits for different types of diseases. We aimed to evaluate the impact of the intervention on hospital visits in Yinzhou District, Ningbo, Zhejiang province, China. METHODS: We conducted an interrupted time-series analysis from 1 January 2017 to 6 September 2020 based on the Yinzhou Health Information System in Ningbo, Zhejiang province. The beginning of the intervention was on 23 January 2020, and thus, there were 160 weeks before the intervention and 32 weeks after the implementation of the intervention. Level changes between expected and observed hospital visits in the post-intervention period were estimated using quasi-Poisson regression models. RESULTS: Compared with the expected level, there was an estimated decrease of -22.60% (95% confidence interval (CI): -27.53%, -17.36%) in the observed total hospital visits following the intervention. Observed hospital visits for diseases of the respiratory system were found to be decreased dramatically (-62.25%; 95% CI: -65.62%, -58.60%). However, observed hospital visits for certain diseases were estimated to be increased, including diseases of the nervous system (+11.17%; 95% CI: +3.21%, +19.74%); diseases of pregnancy, childbirth and the puerperium (+27.01%; 95% CI: +17.89%, +36.85%); certain conditions originating in the perinatal period (+45.05%; 95% CI: +30.24%, +61.56%); and congenital malformation deformations and chromosomal abnormalities (+35.50%; 95% CI: +21.24%, +51.45%). CONCLUSIONS: Our findings provided scientific evidence that cause-specific hospital visits evolve differently following the intervention during the COVID-19 epidemic.

The role of ATF3 in ZnO nanoparticle-induced genotoxicity and cytotoxicity in bronchial epithelial cells.

ZnO nanoparticle (ZnO NP) exposure causes oxidative stress in the respiratory system, leading to pulmonary damage. Activating transcription factor 3 (ATF3) participates in a variety of cellular stress responses. However, the role of ATF3 in ZnO NP genotoxicity and cytotoxicity remains to be explored. Here we reported that ZnO NP treatment dramatically induced the expression of ATF3 in human bronchial epithelial (HBE) cells, which was mediated by the nuclear factor erythroid 2-related factor 2 (Nrf2). ATF3 was required for the repair of ZnO NP-induced DNA damage as gamma foci number increased when endogenous ATF3 was silenced. Moreover, ATF3 also contributed to ZnO NP-induced cell apoptosis. Mechanistic study revealed that ATF3 interacted with the p53 protein and upregulated its expression under ZnO NP treatment. Collectively, our findings demonstrated ATF3 as an important regulator of epithelial homeostasis by promoting both DNA repair and the death of damaged cells under ZnO NP-induced genotoxic stress.

Glycoengineering of Antibodies for Modulating Functions.

Antibodies are immunoglobulins that play essential roles in immune systems. All antibodies are glycoproteins that carry at least one or more conserved N-linked oligosaccharides (N-glycans) at the Fc domain. Many studies have demonstrated that both the presence and fine structures of the attached glycans can exert a profound impact on the biological functions and therapeutic efficacy of antibodies. However, antibodies usually exist as mixtures of heterogeneous glycoforms that are difficult to separate in pure glycoforms. Recent progress in glycoengineering has provided useful methods that enable production of glycan-defined and site-selectively modified antibodies for functional studies and for improved therapeutic efficacy. This review highlights major approaches in glycoengineering of antibodies with a focus on recent advances in three areas: glycoengineering through glycan biosynthetic pathway manipulation, glycoengineering through in vitro chemoenzymatic glycan remodeling, and glycoengineering of antibodies for site-specific antibody-drug conjugation.

Chemoenzymatic Defucosylation of Therapeutic Antibodies for Enhanced Effector Functions Using Bacterial α-Fucosidases.

Core fucosylation plays a critical role in modulating the effector functions of therapeutic antibodies such as the antibody-dependent cellular cytotoxicity (ADCC) through adversely affecting the affinity of antibodies for Fcγ receptors. Thus, a facile method for Fc defucosylation of antibodies is important both for functional studies and for an enhanced therapeutic efficacy. In this chapter, we describe a detailed protocol for chemoenzymatic defucosylation of antibodies using Herceptin (trastuzumab) as a model system. The protocol includes (a) Fc deglycosylation using endoglycosidase S2 (Endo-S2); (b) enzymatic defucosylation of the resulting Fucα1,6GlcNAc-Herceptin using two distinct bacterial α-fucosidases, AlfC and BfFuc; (c) transglycosylation of the GlcNAc-Herceptin using an Endo-S2 mutant (Endo-S2 D184M) as the enzyme and a complex N-glycan oxazoline as the donor substrate; and (d) SPR analysis of the binding of antibody glycoforms with the FcγIIIA receptor. The protocol of enzymatic defucosylation of Herceptin should be equally applicable for the Fc glycan engineering of other mAbs.

Generation and Comparative Kinetic Analysis of New Glycosynthase Mutants from Streptococcus pyogenes Endoglycosidases for Antibody Glycoengineering.

Chemoenzymatic glycan remodeling by endoglycosidase-catalyzed deglycosylation and reglycosylation is emerging as an attractive approach for producing homogeneous glycoforms of antibodies, and the success of this approach depends on the discovery of efficient endoglycosidases and their glycosynthase mutants. We report in this paper a systematic site-directed mutagenesis of an endoglycosidase from Streptococcus pyogenes (Endo-S) at the critical Asp-233 (D233) site and evaluation of the hydrolysis and transglycosylation activities of the resulting mutants. We found that in addition to the previously identified D233A and D233Q mutants of Endo-S, most of the Asp-233 mutants discovered here were also glycosynthases that demonstrated glycosylation activity using glycan oxazoline as the donor substrate with diminished hydrolytic activity. The glycosynthase activity of the resultant mutants varied significantly depending on the nature of the amino acid substituents. Among them, the D233M mutant was identified as the most efficient glycosynthase variant with the highest transglycosylation/hydrolysis ratio, which is similar to the recently reported D184M mutant of Endo-S2, another S. pyogenes endoglycosidase. Kinetic studies of the D233M and D233A mutants of Endo-S, as well as glycosynthase mutants D184M and D184A of Endo-S2, indicated that the enhanced catalytic efficacy of the Asp-to-Met mutants of both enzymes was mainly due to an increased turnover number (increased kcat) for the glycan oxazoline substrate and the significantly enhanced substrate affinity (as judged by the reduced KM value) for the antibody acceptor.

Site-specific immobilization of endoglycosidases for streamlined chemoenzymatic glycan remodeling of antibodies.

Chemoenzymatic glycan remodeling of antibodies using an endoglycosidase and its mutant is emerging as an attractive approach for producing homogeneous antibody glycoforms. We report in this paper a site-specific covalent immobilization of the endoglycosidases (Endo-S2 and its glycosynthase mutant D184M) using a recombinant microbial transglutaminase (MTG) and evaluation of the immobilized enzymes in deglycosylation and glycosylation of a therapeutic antibody. The site-specific covalent immobilization was achieved by introduction of a Q-tag at the C-terminus of the recombinant enzymes followed by conjugation of the enzymes to a primary amine-containing solid support through MTG-catalyzed transglutamination. Using rituximab as a model system, we found that the Endo-S2 wild-type and D184M glycosynthase mutant immobilized by this approach were efficient in the two step antibody glycan remodeling to generate homogeneous antibody glycoforms. Notably using the covalently immobilized enzymes can efficiently avoid the need of intermediate purification and eliminate the residual contamination of wild type enzyme for product hydrolysis, thus streamlining the chemoenzymatic Fc glycan remodeling of antibodies.