Serum level of testosterone predicts disease severity of male COVID-19 patients and is related to T-cell immune modulation by transcriptome analysis.

BACKGROUND: Severe disease of COVID-19 and mortality occur more frequently in male patients than that in female patients may be related to testosterone level. However, the diagnostic value of changes in the level of testosterone in predicting severe disease of male COVID-19 patients has not been determined yet. METHODS: Sixty-one male COVID-19 patients admitted to the First Affiliated Hospital of Zhejiang University School of Medicine were enrolled. Serum samples at different stages of the patients after admission were collected and testosterone levels were detected to analyze the correlation between testosterone level and disease severity. Transcriptome analysis of PBMC was performed in 34 patients. RESULTS: Testosterone levels at admission in male non-ICU COVID-19 patients (3.7 nmol/L, IQR: 1.5 âˆ¼ 4.7) were significantly lower than those in male ICU COVID-19 patients (6.7 nmol/L, IQR: 4.2 âˆ¼ 8.7). Testosterone levels in the non-ICU group increased gradually during the progression of the disease, while those in the ICU group remained low. In addition, testosterone level of enrolled patients in the second week after onset was significantly correlated with the severity of pneumonia, and ROC curve showed that testosterone level in the second week after onset was highly effective in predicting the severity of COVID-19. Transcriptome studies have found that testosterone levels of COVID-19 patients were associated with immune response, including T cell activation and regulation of lymphocyte activation. In addition, CD28 and Inositol Polyphosphate-4-Phosphatase Type II B (INPP4B) were found positively correlated with testosterone. CONCLUSIONS: Serum testosterone is an independent risk factor for predicting the severity of COVID-19 in male patients, and the level of serum testosterone in the second week after onset is valuable for evaluating the severity of COVID-19. Testosterone level is associated with T cell immune activation. The monitoring of serum testosterone should be highlighted in clinical treatment and the related mechanism should be further studied.

Ambient air pollution is associated with cardiac repolarization abnormalities in healthy adults.

BACKGROUND: Ambient air pollution has been associated with acute cardiovascular events; however, the underlying mechanisms remain incompletely understood. We aimed to examine the impacts of ambient air pollutants on cardiac ventricular repolarization in a highly polluted urban region. METHODS: Seventy-three healthy non-smoking young adults (66% female, mean age of 23.3 ±â€¯5.4 years) were followed with four repeated 24-h electrocardiogram recordings in 2014-2016 in Beijing, China. Continuous concentrations of ambient particulates in size fractions of 5-560 nm diameter, black carbon (BC), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3) were measured at a fixed-location air pollution monitoring station. Generalized linear mixed models, with adjustment for individual risk factors, time-varying factors and meteorological parameters, were used to evaluate the effects of air pollution on 5-min segments of heart rate-corrected QT interval (QTc), an index of cardiac ventricular repolarization. RESULTS: During the study period, the mean levels of number concentrations of particulates in size range of 5-560 nm (PNC5-560) were 20,711 particles/cm3. Significant increases in QTc of 0.56% (95% CI: 0.27, 0.84) to 1.76% (95% CI: 0.73, 2.79) were associated with interquartile range increases in PNC50-560 at prior 1-5 moving average days. Significant increases in QTc were also associated with increases in exposures to traffic-related air pollutants (BC, NO2 and CO), a combustion pollutant SO2, and the secondary pollutant O3. The associations were stronger in participants who were male, overweight, with abdominal obesity, and with higher levels of high-sensitivity C-reactive protein. CONCLUSIONS: Our findings suggest that exposures to higher levels of ambient particulates in small size fractions and traffic pollutants were associated with cardiac repolarization abnormalities in healthy adults, and the cardio-metabolic risks may modify the adverse cardiac effects attributable to air pollution.

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Beijing: Seasonal variations, sources, and risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) have been of health concern due to its carcinogenesis and mutagenesis. In this study, we aimed to assess the variations, sources, and lifetime excessive cancer risk (ECR) attributable to PAHs bound to ambient particulate matters with aerodynamic diameter less than 2.5µm (PM2.5) in metropolitan Beijing, China. We collected 24-hour integrated PM2.5 samples on daily basis between November 2014 and June 2015 across both central heating (cold months) and non-heating (warm months) seasons, and further analyzed the PAH components in these daily PM2.5 samples. Our results showed that total concentrations of PM2.5-bound PAHs varied between (88.6±75.4)ng/m3 in the cold months and (11.0±5.9)ng/m3 in the warm months. Benzo[a]pyrene (BaP), the carcinogenic marker of PAHs, averaged at 5.7 and 0.4ng/m3 in the cold and warm months, respectively. Source apportionment analyses illustrated that gasoline, biomass burning, diesel, coal combustion and cooking were the major contributors, accounting for 12.9%, 17.8%, 24.7%, 24.3% and 6.4% of PM2.5-bound PAHs, respectively. The BaP equivalent lifetime ECR from inhalation of PM2.5-bound PAHs was 16.2 cases per million habitants. Our results suggested that ambient particulate reduction from energy reconstruction and adaption of clean fuels would result in reductions PM2.5-bound PAHs and its associated cancer risks. However, as only particulate phased PAHs was analyzed in the present study, the concentration of ambient PAHs could be underestimated.

Cardiovascular benefits of short-term indoor air filtration intervention in elderly living in Beijing: An extended analysis of BIAPSY study.

BACKGROUND: Adverse cardiovascular effects associated with air pollution exposure have been widely demonstrated. However, inconsistent cardiovascular responses were observed from reducing indoor air pollution exposure. We aimed to assess whether short-term air filtration intervention could benefit cardiovascular health in elderly living in high pollution area. METHODS: A randomized crossover intervention study of short-term indoor air filtration intervention on cardiovascular health was conducted among 35 non-smoking elderly participants living in Beijing in the winter of 2013, as part of Beijing Indoor Air Purifier StudY (BIAPSY). Portable air filtration units were randomly allocated to active filtration for 2 weeks and sham filtration for 2 weeks in the households. Twelve-hour daytime ambulatory heart rate variability (HRV) and blood pressure (ABP) were measured during active and sham filtration. Concurrently, real-time indoor and outdoor particulate matter with diameter less than 2.5 µm (PM2.5) and indoor black carbon (BC) concentrations were measured. We applied generalized additive mixed models to evaluate the associations of 1- to 10-h moving average (MA) exposures of indoor PM2.5 and BC with HRV and ABP indices, and to explore whether these associations could be modified by air filtration. RESULTS: We observed decreases of 34.8% in indoor PM2.5 and 35.3% in indoor BC concentrations during active filtration. Indoor PM2.5 and BC exposures were significantly associated with reduced HRV and increased ABP indices, and greater changes were observed during sham filtration. In specific, each 10 µg/m3 increase in indoor PM2.5 at MA8-h was associated with a significant reduction of 1.34% (95% CI: -2.42, -0.26) in SDNN during sham filtration, compared with a non-significant reduction of 0.81% (95% CI: -6.00, 4.68) during active filtration (Pinter< 0.001). Each 1 µg/m3 increase in indoor BC at MA8-h was associated with a significant increase of 2.41% (95% CI: 0.38, 4.47) in SBP during sham filtration, compared with a non-significant increase of -1.09% (95% CI: -4.06, 1.96) during active filtration (Pinter = 0.135). Nonlinear inverse exposure-response relationships of indoor air pollution exposures with predicted HRV and ABP indices also confirmed some cardiovascular benefits of short-term air filtration intervention. CONCLUSIONS: Our results suggested that short-term indoor air filtration intervention can be of some cardiovascular benefits in elderly living with high pollution episodes.

Metabolomics analysis reveals that benzo[a]pyrene, a component of PM2.5, promotes pulmonary injury by modifying lipid metabolism in a phospholipase A2-dependent manner in vivo and in vitro.

Particulate matter with an aerodynamic diameter less than 2.5µM (PM2.5) is one of the major environmental pollutants in China. In this study, we carried out a metabolomics profile study on PM2.5-induced inflammation. PM2.5 from Beijing, China, was collected and given to rats through intra-tracheal instillation in vivo. Acute pulmonary injury were observed by pulmonary function assessment and H.E. staining. The lipid metabolic profile was also altered with increased phospholipid and sphingolipid metabolites in broncho-alveolar lavage fluid (BALF) after PM2.5 instillation. Organic component analysis revealed that benzo[a]pyrene (BaP) is one of the most abundant and toxic components in the PM2.5 collected on the fiber filter. In vitro, BaP was used to treat A549 cells, an alveolar type II cell line. BaP (4µM, 24h) induced inflammation in the cells. Metabolomics analysis revealed that BaP (4µM, 6h) treatment altered the cellular lipid metabolic profile with increased phospholipid metabolites and reduced sphingolipid metabolites and free fatty acids (FFAs). The proportion of ω-3 polyunsaturated fatty acid (PUFA) was also decreased. Mechanically, BaP (4µM) increased the phospholipase A2 (PLA2) activity at 4h as well as the mRNA level of Pla2g2a at 12h. The pro-inflammatory effect of BaP was reversed by the cytosolic PLA2 (cPLA2) inhibitor and chelator of intracellular Ca2+. This study revealed that BaP, as a component of PM2.5, induces pulmonary injury by activating PLA2 and elevating lysophosphatidylcholine (LPC) in a Ca2+-dependent manner in the alveolar type II cells.

Cardiorespiratory responses of air filtration: A randomized crossover intervention trial in seniors living in Beijing: Beijing Indoor Air Purifier StudY, BIAPSY.

In this Beijing Indoor Air Purifier StudY (BIAPSY), we conducted a randomized crossover intervention trial in a panel of 35 non-smoking senior participants with free-living, with and without chronic obstructive pulmonary disease (COPD). Portable air filtration units were randomly allocated to active-(filter in) for 2weeks and sham-mode (filter out) for 2weeks in the households. We examined the differences in indoor air pollutant concentrations in 20 study homes and a suite of cardio-respiratory biomarker levels in study participants between filtration modes, with and without adjustment for potential confounders. Following active filtration, we observed significant reductions from 60±45 to 24±15µg/m3 in ten-day averages of indoor PM2.5 and reductions from 3.87±1.65 to 1.81±1.19m-1.10-5 in ten-day averages of indoor BC, compared to sham-mode filtration. The major components of indoor PM2.5, including water soluble organics, NO3-, SO42-, Zn2+, Pb2+ and K+, were also reduced significantly by 42% to 63%. However, following active filtration, we only observed significant reductions on systemic inflammation measured as of IL-8 at 58.59% (95% CI: -76.31, -27.64) in the total group of participants and 70.04% (95% CI: -83.05, -47.05) in the subset of COPD patients, with adjustments. We were not able to detect improvements on lung function, blood pressure, and heart rate variability, following short-term intervention of two-week active air filtration. In conclusion, our results showed that indoor air filtration produced clear improvement on indoor air quality, but no demonstrable changes in the cardio-respiratory outcomes of study interest observed in the seniors living with real-world air pollution exposures.

NADPH oxidase-produced superoxide mediated a 50-Hz magnetic field-induced epidermal growth factor receptor clustering.

PURPOSE: A 50-Hz magnetic field (MF) was found to induce epidermal growth factor receptor (EGFR) clustering in our previous study. The aim of this work was to investigate the molecular mechanisms that mediated MF-induced EGFR clustering. MATERIALS AND METHODS: Human amniotic epithelial (FL) cells were exposed to a 50-Hz MF. Total reactive oxygen species (ROS), cytoplasmic and mitochondrial superoxide production were detected by DCFH-DA, DHE and MitoSOX, respectively. EGFR clustering was analyzed using confocal microscopy after indirect immunofluorescence staining. RESULTS: Results showed that exposing FL cells to MF at intensity higher than 0.2 mT for 15 min enhanced total ROS production. Additionally, enhanced total ROS and cytoplasmic superoxide production were observed after exposing cells to MF at 0.4 mT for 5, 15, or 30 min, while mitochondrial superoxide production for 15 or 30 min. Pretreatment with Nox inhibitor, DPI, effectively inhibited MF-induced cytoplasmic superoxide production and subsequent EGFR clustering while mitochondrial superoxide production was not affected. CONCLUSIONS: Nox-produced superoxide mediated a 50-Hz magnetic field-induced EGFR clustering.

Mitochondrial ROS Release and Subsequent Akt Activation Potentially Mediated the Anti-Apoptotic Effect of a 50-Hz Magnetic Field on FL Cells.

BACKGROUND/AIMS: Our previous study showed that exposure to a 50-Hz magnetic field (MF) could induce transient mitochondrial permeability transition (MPT) in cells. In the present study, the aim was to explore the possible biological implications of MF-induced transient MPT. MATERIALS AND METHODS: Human amniotic (FL) cells were exposed to MF for different durations or intensities followed by incubation with staurosporine for 4 h. After MF exposure, cell early apoptosis, cell viability mitochondrial ROS and the level of phosphorylated Akt were assessed. After MF exposure followed by incubation with staurosporine, cell early apoptosis was assessed. RESULTS: MF exposure had a protective effect against early apoptosis induced by staurosporine, which could be abolished by MPT inhibitors, although MF exposure alone had no significant effect on early apoptosis or viability of cells. In addition, exposing cells to MF increased the level of mitochondrial ROS which were released into cytoplasm through mitochondrial permeability transition pores (mPTP), and induced ROS-dependent phosphorylation of Akt. Furthermore, the anti-apoptotic effect of MF exposure was completely eliminated when Akt was inhibited. CONCLUSIONS: The present study indicated a possibility that mitochondrial ROS release through mPTP and subsequent Akt activation were necessary for the anti-apoptotic effect of MF.

Acid sphingomyelinase mediates 50-Hz magnetic field-induced EGF receptor clustering on lipid raft.

Previously, we found that exposure to a 50-Hz magnetic field (MF) could induce epidermal growth factor receptor (EGFR) clustering and phosphorylation on cell surface. In order to explore the possible mechanisms, the roles of acid sphingomyelinase (ASMase) and lipid raft in MF-induced EGFR clustering were investigated in the present study. Human amnion epithelial (FL) cells were exposed to a 50-Hz MF at 0.4 mT for different durations. Intracellular ASMase activity was detected using the Amplex® Red Sphingomyelinase Assay Kit. EGFR clustering, ASMase, and lipid rafts on cell membrane were analyzed using confocal microscopy after indirect immunofluorescence staining. Results showed that disturbing lipid rafts with nystatin could inhibit MF-induced EGFR clustering, indicating that it was dependent on intact lipid raft. Exposure of FL cells to MF significantly enhanced ASMase activity and induced ASMase translocation to membrane that co-localized with lipid rafts. Treatment with imipramine, an ASMase inhibitor, inhibited the MF-induced EGFR clustering. This inhibitory effect could be blocked by the addition of C2-ceramide in the culture medium. It suggested that ASMase mediated the 50-Hz MF-induced EGFR clustering via ceramide which was produced from hydrolyzation on lipid rafts.

Exposure to a 50-Hz magnetic field induced mitochondrial permeability transition through the ROS/GSK-3ß signaling pathway.

PURPOSE: To investigate the biological effects of a 50-Hz magnetic field (MF) on mitochondrial permeability. MATERIALS AND METHODS: Human amniotic epithelial cells were exposed to MF (50 Hz, 0.4 mT) for different durations. Mitochondrial permeability, mitochondrial membrane potential (ΔΨm), cytochrome c (Cyt-c) release and the related mechanisms were explored. RESULTS: Exposure to the MF at 0.4 mT for 60 min transiently induced mitochondrial permeability transition (MPT) and Cyt-c release, although there was no significant effect on mitochondrial membrane potential (ΔΨm). Other than decreasing the total Bcl-2 associated X protein (Bax) level, MF exposure did not significantly affect the levels of Bax and B-cell lymphoma-2 (Bcl-2) in mitochondria. In addition, cells exposed to the MF showed increased intracellular reactive oxidative species (ROS) levels and glycogen synthase kinase-3ß (GSK-3ß) dephosphorylation at 9 serine residue (Ser(9)). Moreover, the MF-induced MPT was attenuated by ROS scavenger (N-acetyl-L-cysteine, NAC) or GSK-3ß inhibitor, and NAC pretreatment prevented GSK-3ß dephosphorylation (Ser(9)) caused by MF exposure. CONCLUSION: MPT induced by MF exposure was mediated through the ROS/GSK-3ß signaling pathway.