Mechanical stretch promotes apoptosis and impedes ciliogenesis of primary human airway basal stem cells.

BACKGROUND: Airway basal stem cells (ABSCs) have self-renewal and differentiation abilities. Although an abnormal mechanical environment related to chronic airway disease (CAD) can cause ABSC dysfunction, it remains unclear how mechanical stretch regulates the behavior and structure of ABSCs. Here, we explored the effect of mechanical stretch on primary human ABSCs. METHODS: Primary human ABSCs were isolated from healthy volunteers. A Flexcell FX-5000 Tension system was used to mimic the pathological airway mechanical stretch conditions of patients with CAD. ABSCs were stretched for 12, 24, or 48 h with 20% elongation. We first performed bulk RNA sequencing to identify the most predominantly changed genes and pathways. Next, apoptosis of stretched ABSCs was detected with Annexin V-FITC/PI staining and a caspase 3 activity assay. Proliferation of stretched ABSCs was assessed by measuring MKI67 mRNA expression and cell cycle dynamics. Immunofluorescence and hematoxylin-eosin staining were used to demonstrate the differentiation state of ABSCs at the air-liquid interface. RESULTS: Compared with unstretched control cells, apoptosis and caspase 3 activation of ABSCs stretched for 48 h were significantly increased (p < 0.0001; p < 0.0001, respectively), and MKI67 mRNA levels were decreased (p < 0.0001). In addition, a significant increase in the G0/G1 population (20.2%, p < 0.001) and a significant decrease in S-phase cells (21.1%, p < 0.0001) were observed. The ratio of Krt5+ ABSCs was significantly higher (32.38% vs. 48.71%, p = 0.0037) following stretching, while the ratio of Ac-tub+ cells was significantly lower (37.64% vs. 21.29%, p < 0.001). Moreover, compared with the control, the expression of NKX2-1 was upregulated significantly after stretching (14.06% vs. 39.51%, p < 0.0001). RNA sequencing showed 285 differentially expressed genes, among which 140 were upregulated and 145 were downregulated, revealing that DDIAS, BIRC5, TGFBI, and NKX2-1 may be involved in the function of primary human ABSCs during mechanical stretch. There was no apparent difference between stretching ABSCs for 24 and 48 h compared with the control. CONCLUSIONS: Pathological stretching induces apoptosis of ABSCs, inhibits their proliferation, and disrupts cilia cell differentiation. These features may be related to abnormal regeneration and repair observed after airway epithelium injury in patients with CAD.

An imbalance of the IL-33/ST2-AXL-efferocytosis axis induces pregnancy loss through metabolic reprogramming of decidual macrophages.

During embryo implantation, apoptosis is inevitable. These apoptotic cells (ACs) are removed by efferocytosis, in which macrophages are filled with a metabolite load nearly equal to the phagocyte itself. A timely question pertains to the relationship between efferocytosis-related metabolism and the immune behavior of decidual macrophages (dMΦs) and its effect on pregnancy outcome. Here, we report positive feedback of IL-33/ST2-AXL-efferocytosis leading to pregnancy failure through metabolic reprogramming of dMΦs. We compared the serum levels of IL-33 and sST2, along with IL-33 and ST2, efferocytosis and metabolism of dMΦs, from patients with normal pregnancies and unexplained recurrent pregnancy loss (RPL). We revealed disruption of the IL-33/ST2 axis, increased apoptotic cells and elevated efferocytosis of dMΦs from patients with RPL. The dMΦs that engulfed many apoptotic cells secreted more sST2 and less TGF-ß, which polarized dMΦs toward the M1 phenotype. Moreover, the elevated sST2 biased the efferocytosis-related metabolism of RPL dMΦs toward oxidative phosphorylation and exacerbated the disruption of the IL-33/ST2 signaling pathway. Metabolic disorders also lead to dysfunction of efferocytosis, resulting in more uncleared apoptotic cells and secondary necrosis. We also screened the efferocytotic molecule AXL regulated by IL-33/ST2. This positive feedback axis of IL-33/ST2-AXL-efferocytosis led to pregnancy failure. IL-33 knockout mice demonstrated poor pregnancy outcomes, and exogenous supplementation with mouse IL-33 reduced the embryo losses. These findings highlight a new etiological mechanism whereby dMΦs leverage immunometabolism for homeostasis of the microenvironment at the maternal-fetal interface.

Fertility Intentions, Parenting Attitudes, and Fear of Childbirth among College Students in China: A Cross-Sectional Study.

STUDY OBJECTIVE: This study aimed to investigate the current situation regarding fertility intentions, parenting attitudes, and fear of childbirth among college students in mainland China and the factors related to these variables. DESIGN: A cross-sectional study SETTING: Colleges across China PARTICIPANTS: Five hundred and eighty-three college students attending regular institutions of higher education MAIN OUTCOME MEASURES: Fertility intentions and fear of childbirth were measured using the Swedish Fertility Awareness Questionnaire and the Childbirth Fear Prior to Pregnancy scale. RESULTS: Only 38.8% of participants expressed their willingness to have children, and there was a significant difference between male and female students (P < .02). Males regarded having children as more important (P < .01), and females were more concerned about the negative effects of becoming parents, including difficulties in the labor market, having less freedom, and having less money. When deciding whether to have children, factors such as work, economics, and childcare were more important to females. Students who did not want children had higher levels of fear of childbirth than those who wanted children or were unsure (P < .02). CONCLUSIONS: The fertility intentions of college students were not optimistic. In addition to the 2-child Chinese fertility policy, interventions aimed at reducing the cost of raising children, eliminating gender inequality in the workplace, and normalizing childcare institutions might help alleviate conflict between work and childrearing.

Heme induced progesterone-resistant profiling and promotion of endometriosis in vitro and in vivo.

Endometriosis is an estrogen-dependent, progesterone-resistant gynecological disease with an unknown pathogenesis. Compared to women without endometriosis, women with endometriosis have a remarkably high heme level in the peritoneal fluid. To further investigate the pathomechanisms of heme in endometriosis, we aimed to identify the dysregulated expression of heme-trafficking proteins, such as PGRMC1/2 that are also receptors that mediate the non-genomic responses to progesterone, and heme-degrading enzymes between ectopic endometrial stromal cells and their normal counterparts. We found that heme could regulate progesterone receptor-related gene expression. Functional human endometrial stromal cell experiments showed that heme promotes cell proliferation and migration in a heme oxygenase-1-independent manner; moreover, blocking oxidative phosphorylation/ATP generation could abolish these effects of heme in vitro, whereas intraperitoneal hemopexin administration could alleviate heme-triggered ectopic lesions in vivo. Therefore, heme likely mediates the induction of progesterone resistance and simultaneously induces endometriosis via the mitochondrial oxidative phosphorylation pathway.

Experimental and kinetic modeling of oxygen-enriched air combustion of municipal solid waste.

The characteristics of oxygen-enriched air combustion of raw municipal solid waste (MSW) were studied by thermogravimetric analysis. Experiments on oxidative pyrolysis of MSW were carried out under different atmospheres (N(2), N(2):O(2)=7:3, N(2):O(2)=5:5, N(2):O(2)=4:6, and N(2):O(2)=2:8) at 30 degrees C/min. Two distinct peaks of weight loss were obtained according to the derivative thermogravimetric curves; one of them is centered on 305 degrees C with about 40% weight loss, and the second is centered on 420 degrees C with about 20% weight loss. Effects of oxygen concentration on the decomposition process and char combustion were analyzed, and then the process of oxygen-enriched air combustion of MSW was divided into four steps. Kinetic parameters were observed by direct non-linear regressions. According to the obtained data, the apparent activation energy and reaction order decreases along with the combustion process, while that of char combustion increases as oxygen concentration increases.

DNAzymes targeted to EBV-encoded latent membrane protein-1 induce apoptosis and enhance radiosensitivity in nasopharyngeal carcinoma.

Epstein-Barr virus (EBV) is involved in the carcinogenesis of several types of cancers such as nasopharyngeal carcinoma (NPC) and Burkitt's lymphoma. The latent membrane protein (LMP1) encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. Therefore, genetic manipulation of LMP1 expression may provide a novel strategy for the treatment of the EBV-associated human cancers. Deoxyribozymes (DNAzymes) are catalytic nucleic acids that bind and cleave a target RNA in a highly sequence-specific manner. We have designed several LMP1-specific DNAzymes and tested their effect on cell proliferation and apoptosis in LMP1-positive cells. Here, we show that active DNAzymes down-regulated the expression of the EBV oncoprotein LMP1 and inhibited cellular signal transduction pathways abnormally activated by LMP1. This down-regulation of the LMP1 expression was shown to be associated with a decrease in the level of antiapoptotic Bcl-2 and an increase in Caspase-3 and -9 activities in the nasopharyngeal carcinoma cell line CNE1-LMP1, which constitutively expresses the LMP1. When combined with radiation treatment, the DNAzymes significantly induced apoptosis in CNE1-LMP1 cells, leading to an increased radiosensitivity both in cells and in a xenograft NPC model in mice. The results suggest that LMP1 may represent a molecular target for DNAzymes and provide a basis for the use of the LMP1 DNAzymes as potential radiosensitizers for treatment of the EBV-associated carcinomas.

Experimental and kinetic modeling of oxygen-enriched air combustion of paper mill sludge.

By thermogravimetric analysis (TGA) study, the characteristics of oxygen-enriched air combustion of paper mill sludge were investigated. Experiments on oxidative of paper mill sludge were performed under different atmospheres at 20 degrees C/min. There are two distinct decomposition processes were observed from the obtained thermogravimetric curves. One of them centered on 320-350 degrees C with a weight loss of 50%, the second centered on 780-795 degrees C with a weight of loss 30%. Shift of oxygen concentration have some influences on decomposition processes, and then the processes of paper mill sludge combustion in oxygen-enriched air can be divided into three stages. The kinetic parameters observed by direct non-linear regressions. At the fixed carbon combustion stage, when oxygen concentration from 20 to 80 vol.%, the apparent activation energy is increased from 52.30 to 123.16 kJ/mol, the reaction order of all runs are around 1.