Associations of cord serum polybrominated diphenyl ether (PBDE) mixture with birth outcomes and mediating role of thyroid function: Evidence from the Sheyang Mini Birth Cohort Study.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs), a series of worldwide applied flame retardants, may influence fetal growth and interfere with thyroid function. The study intended to explore the relationship between in-utero exposure to PBDE mixture and newborn anthropometric indexes and to further examine the potential mediating role of thyroid function. METHODS: Demographics and laboratory measures of 924 mother-infant pairs were obtained from the database of the Sheyang Mini Birth Cohort Study. We applied gas chromatography-mass spectrometry (GC-MS) and electrochemiluminescence immunoassay to measure nine PBDE congeners and seven thyroid function parameters in umbilical cord serum samples, respectively. We fitted generalized linear models and Bayesian kernel machine regression (BKMR) to evaluate associations of lipid-adjusted cord serum PBDEs, as individuals and as a mixture, with newborn anthropometric and cord serum thyroid function parameters. We applied causal mediation analysis to test our hypothesis that thyroid function parameters act as a mediator between PBDEs and birth outcomes. RESULTS: The molarity of cord serum ∑9PBDE had a median value of 31.23 nmol/g lipid (IQR 19.14 nmol/g lipid, 54.77 nmol/g lipid). BDE-209 was the most dominant congener. Birth length was positively associated with both single exposure to BDE-28 and cumulative exposure to PBDEs. Correspondingly, ponderal index (PI) was negatively associated with BDE-28 and the total effects of PBDE mixture. Free triiodothyronine had a negative trend with BDE-209 and PBDE mixture. In the sex-stratified analysis, BDE-153 concentrations were positively correlated with PI among males (ß = 0.03; 95%CI: 0.01, 0.05; P = 0.01) but not among females. Cord serum thyrotropin mediated 14.92% of the estimated effect of BDE-153 on PI. CONCLUSIONS: In-utero mixture exposure to PBDEs was associated with birth outcomes and thyroid function. Thyroid function might act as a mediator in the process in which PBDEs impact the growth of the fetus.

lhCLIP reveals the in vivo RNA-RNA interactions recognized by hnRNPK.

RNA-RNA interactions play a crucial role in regulating gene expression and various biological processes, but identifying these interactions on a transcriptomic scale remains a challenge. To address this, we have developed a new biochemical technique called pCp-biotin labelled RNA hybrid and ultraviolet crosslinking and immunoprecipitation (lhCLIP) that enables the transcriptome-wide identification of intra- and intermolecular RNA-RNA interactions mediated by a specific RNA-binding protein (RBP). Using lhCLIP, we have uncovered a diverse landscape of intermolecular RNA interactions recognized by hnRNPK in human cells, involving all major classes of noncoding RNAs (ncRNAs) and mRNA. Notably, hnRNPK selectively binds with snRNA U4, U11, and U12, and shapes the secondary structure of these snRNAs, which may impact RNA splicing. Our study demonstrates the potential of lhCLIP as a user-friendly and widely applicable method for discovering RNA-RNA interactions mediated by a particular protein of interest and provides a valuable tool for further investigating the role of RBPs in gene expression and biological processes.

An immune cell atlas reveals the dynamics of human macrophage specification during prenatal development.

Macrophages are heterogeneous and play critical roles in development and disease, but their diversity, function, and specification remain inadequately understood during human development. We generated a single-cell RNA sequencing map of the dynamics of human macrophage specification from PCW 4-26 across 19 tissues. We identified a microglia-like population and a proangiogenic population in 15 macrophage subtypes. Microglia-like cells, molecularly and morphologically similar to microglia in the CNS, are present in the fetal epidermis, testicle, and heart. They are the major immune population in the early epidermis, exhibit a polarized distribution along the dorsal-lateral-ventral axis, and interact with neural crest cells, modulating their differentiation along the melanocyte lineage. Through spatial and differentiation trajectory analysis, we also showed that proangiogenic macrophages are perivascular across fetal organs and likely yolk-sac-derived as microglia. Our study provides a comprehensive map of the heterogeneity and developmental dynamics of human macrophages and unravels their diverse functions during development.

Efficacy and Mechanisms of Oleuropein in Postmenopausal Osteoporosis.

Background: Postmenopausal osteoporosis (PMOP) has a supernal morbidity rate in elderly females. Objective: To appraise the effects of oleuropein on bone densitometry, bone metabolic index, oxidative stress, and inflammatory index in PMOP. In addition, the mechanism of olive bittersweet preventing bone loss was explored. Methods: We grouped 80 salubrious female Sprague-Dawley rats into four teams: (1) sham operation team (sham, N = 20), (2) ovariectomy (OVX, N = 20), (3) castrated mice fed with oleuropein (OVX+ole, N = 20), and (4) castrated mice fed with estrogen (OVX+E2, N = 20). The ovariectomized SD rats were continuously raised with 200 µg/kg/dose of oleuropein. Bone mineral density and bone metabolism indexes were recorded. In order to assess the effectiveness of oleuropein on osteopenia, an enzyme-linked immunosorbent assay (ELISA) was devoted to examining the bone marrow indexes. The bone metabolism standards of PMOP rats were appraised by assessing serum levels of calcium, alkaline phosphatase (ALP), phosphorus, malondialdehyde (MDA), and nitrate content by experimental detection methods and levels of osteoclastogenesis inhibitory factor (OPG) and receptor activator for nuclear factor-κB ligand (RANKL) by ELISA. The OPG-RANK-RANKL signal passage was examined by Western blot (WB). We measured bone mineral density using dual-energy X-rays. Results: Our animal experimental results indicated that oleuropein could significantly improve the bone mineral density of ovariectomized SD rats. In the meantime, it could reduce ending interleukin-6 (IL-6), malondialdehyde (MDA), nitrate, alkaline phosphatase (ALP), and phosphorus (P) serum concentration and would not affect Ca2+ concentration. In cell experiments, oleuropein also can promote the proliferation of osteoblasts. Furthermore, it can promote the expression of OPG protein and mRNA. In reverse, it inhibits the expression of RANKL protein and mRNA. Conclusion: Oleuropein can not only improve the inflammatory and oxidative indexes of castrated rats but also prevent osteoporosis. Oleuropein avoids bone resorption by regulating OPG/RANKL expression.

Clinical effect of electrical stimulation biofeedback therapy combined with pelvic floor functional exercise on postpartum pelvic organ prolapse.

OBJECTIVE: To investigate the clinical effect of electrical stimulation biofeedback therapy combined with pelvic floor functional exercise on postpartum pelvic organ prolapse. METHODS: One hundred and four patients with postpartum pelvic organ prolapse were randomly divided into two groups. There were 52 patients in the control group who were given pelvic floor function exercise. Another 52 patients in the study group were given electrical stimulation biofeedback therapy combined with pelvic floor functional exercises. The clinical efficacy, pelvic floor pressure (contraction pressure, resting pressure, contraction duration), improvement of pelvic floor prolapse, pelvic floor surface muscle potential, quality of sex life and quality of life (PFIQ-7 score and PFDI-20 score) were compared between the two groups. RESULTS: After the therapy, the total effective rate of the study group was higher than that of the control group (P<0.05). The contraction pressure, resting pressure and vaginal contraction duration of the two groups all increased, and the indexes of the study group were higher than those of the control group (P<0.05). The pelvic floor prolapse degree of the two groups tended to be 0 degrees and I light, and the improvement of the study group was better than that of the control group (P<0.05). The average and maximum average values of the resting stage, endurance test stage and re-resting stage of the two groups all increased, and the fast muscle contraction time, fast muscle relaxation time and variability value all decreased, and the improvement of the study group was better than that of the control group (P<0.05). The scores of sexual satisfaction, sexual anxiety, sexual communication, sexual reaction, sexual attitude and sexual body image of the two groups all increased, and the scores of the study group were higher than those of the control group (P<0.05). The scores of PFIQ-7 and PFDI-20 in the two groups all decreased, and the scores of the study group were lower than those of the control group (P<0.05). CONCLUSION: Electrical stimulation biofeedback therapy combined with pelvic floor functional exercise has a noticeable curative effect and can significantly alleviate pelvic floor prolapse and improve the sex life and quality of life of patients.

Umbilical cord serum PBDE concentrations and child adiposity measures at 7 years.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) exist extensively in the environment. Toxicological studies suggested PBDEs may interfere with adipogenic pathways. However, few human evidence addressed PBDE exposures in utero related to childhood adiposity. OBJECTIVE: We assessed associations between PBDEs concentrations in cord serum and childhood adiposity measures at 7 years. METHODS: Among 318 mother-child pairs from Sheyang Mini Birth Cohort Study (SMBCS) in China, nine PBDE congener concentrations were quantified in umbilical cord serum using gas chromatography-negative chemical ionization mass spectrometry (GC-NCI-MS). Anthropometric indicators of children aged 7 years were measured, including weight, height and waist circumference. Age and sex-specific body mass index (BMI) z scores were calculated based on World Health Organization (WHO)'s child growth standards. Multivariate linear and logistic regression models adjusted for putative confounders were performed to examine associations between PBDE congeners and adiposity parameters. RESULTS: BDE-209 was the most abundant congener of PBDEs with a median value of 19.5 ng/g lipid. The geometric mean values of nine PBDE congeners ranged from below limit of detection (LOD) to 18.1 ng/g lipid, and the detection rates were 46.5%~96.5%. Cord serum BDE-153 and BDE-154 concentrations were associated with lower childhood BMI z score (regression coefficient, ß=-0.15, 95% confidence interval: -0.29, -0.02; p=0.02; ß=-0.23, 95%CI: -0.43, -0.03; p=0.03, respectively) and lower waist circumference (ß=-0.75 cm, 95%CI: -1.43, -0.06; p=0.03; ß=-1.22 cm, 95%CI: -2.23, -0.21; p=0.02, respectively), after controlling for potential confounders. Moreover, prenatal BDE-154 exposure was related to a decreased obesity risk of children aged 7 years (odds ratio, OR=0.46, 95%CI: 0.22, 0.94; p=0.03). These effects were only observed among boys in sex-straitified analyses. CONCLUSIONS: Cord serum BDE-153 and BDE-154 concentrations were related to reduced adiposity measures at 7 years of age. Further evidence regarding the impacts of prenatal PBDE exposures on childhood development is warranted.

Correlation of chromosome damage and promoter methylation status of the DNA repair genes MGMT and hMLH1 in Chinese vinyl chloride monomer (VCM)-exposed workers.

OBJECTIVE: To explore the association of the methylation status of MGMT and hMLH1 with chromosome damage induced by vinyl chloride monomer (VCM). MATERIALS AND METHODS: Methylation of MGMT and hMLH1 was measured in 101 VCM-exposed workers by methylation-specific PCR. Chromosome damage in peripheral blood lymphocytes was measured by the cytokinesis-block micronucleus assay. The subjects were divided into chromosome damaged and non-damaged groups based on the normal reference value of micronuclei frequencies determined for two control groups. RESULTS: MGMT promoter methylation was detectable in 5 out of 49 chromosome damaged subjects, but not in the chromosome non-damaged subjects; there was a significant difference in MGMT methylation between the two groups (p < 0.05). CONCLUSIONS: We detected aberrant promoter methylation of MGMT in a small number of chromosome damaged VCM-exposed workers, but not in the chromosome non-damaged subjects. This preliminary observation warrants further investigation in a larger study.

Genotoxicity in vinyl chloride-exposed workers and its implication for occupational exposure limit.

BACKGROUND: Vinyl chloride monomer (VCM) is a colorless gas under room temperature and has been mostly used to produce polyvinyl chloride (PVC) since the 1970s. It is classified by the International Agency of Research on Cancer (IARC) as a known human carcinogen (Group 1). In this study, genetic damage in VCM workers was evaluated in relation to their occupational cumulative exposure to VCM. METHODS: Cytokinesis-block micronucleus assay was conducted in 229 VCM workers and 138 controls to detect chromosome damage in peripheral blood lymphocytes. The cumulative exposure dose (CED) of VCM was calculated based on the job type and duration of each worker and the workplace VCM concentration. Dose-response relationships between VCM CED and micronucleus frequency or chromosomal damage were evaluated, and benchmark doses (BMDs) estimated. RESULTS: Dose-response relationships between VCM CED and chromosomal damage were obtained. The 95% lower confidence bound of BMD of VCM CED was 2.86 mg/m(3) -year for both genders combined, leading to an estimated exposure limit of 0.072 mg/m(3) assuming a work life of 40 years. CONCLUSIONS: VCM exposure may induce chromosomal damage at occupational exposure levels below the Chinese national occupational health standard. Further research is needed to better understand micronuclei as biomarker of VCM genotoxicity. Better dose-response assessment and BMD estimation are desirable in order to improve the quantification of occupational exposure limits for VCM with respect to non-cancer risk.

Genetic polymorphisms of XRCC1, HOGG1 and MGMT and micronucleus occurrence in Chinese vinyl chloride-exposed workers.

In this study, a group of 313 workers occupationally exposed to vinyl chloride monomer (VCM) and 141 normal unexposed referents were examined for chromosomal damage using the cytokinesis-blocked micronucleus (CBMN) assay in peripheral lymphocytes. We explored the relationship between genetic polymorphisms of XRCC1 (Arg194Trp, Arg280His and Arg399Gln), MGMT(Leu84Phe) and hOGG1 (Ser326Cys) and susceptibility of chromosomal damage induced by VCM. Polymerase chain reaction-restriction fragment length polymorphism techniques were used to detect polymorphisms in XRCC1, hOGG1 and MGMT. It was found that the micronuclei (MN) frequency of exposed workers (4.86 +/- 2.80) per thousand was higher than that of the control group (1.22 +/- 1.24) per thousand (P < 0.01). Increased susceptibility to chromosomal damage as evidenced by higher MN frequency was found in workers with hOGG1 326 Ser/Cys genotype [frequency ratio (FR) = 1.21, 95% confidence interval (CI): 1.02-1.46; P < 0.05], XRCC1 194 Arg/Trp (FR = 1.12, 95% CI: 1.00-1.25; P < 0.05) and XRCC1 280 Arg/His and His/His genotypes (FR = 1.12, 95% CI 1.00-1.26, P < 0.05). Moreover, among susceptibility diplotypes, CGA/CAG carriers had more risk of MN frequency compared with individuals with wild-type CGG/CGG (FR = 1.67, 95% CI: 1.19-2.23; P < 0.05). MN frequency also increased significantly with age in the exposed group (FR = 1.13, 95% CI: 1.00-1.28; P < 0.05). Thus, CB-MN was a sensitive index of early damage among VCM-exposed workers. Genotype XRCC1 Arg194Trp, Arg280His, hOGG1 Ser326Cys, diplotype CGA/CAG and higher age may have an impact on the chromosome damage induced by VCM.

Genetic polymorphisms in metabolizing enzymes and susceptibility of chromosomal damage induced by vinyl chloride monomer in a Chinese worker population.

OBJECTIVE: To evaluate whether polymorphisms in metabolizing enzymes contributed to susceptibility of chromosomal damage induced by vinyl chloride monomer (VCM). METHODS: Cytokinesis block micronucleus test was performed on 185 VCM-exposed workers and 41 control subjects to detect chromosomal damage in peripheral lymphocytes. The polymerase chain reaction and restriction fragment length polymorphism technique was applied to detect polymorphisms of GSTT1, GSTM1, GSTP1G/A, CYP2E1G/C, and CYP2D6G/C. Poisson regression analysis was performed. RESULTS: Sex, age, VCM exposure, GSTP1, and CYP2E1 genotype can influence chromosomal damage. There was a 1.51-fold increased micronucleus frequency for GSTP1GG genotypes individuals compared with those GSTP1AA/GA genotype individuals (P < 0.05), the effect of polymorphism in CYP2E1 gene was more pronounced for allele C compared with allele G (P < 0.05). CONCLUSIONS: Polymorphisms of GSTP1G/A and CYP2E1G/C, which are potential susceptibility biomarkers of chromosomal damage in VCM-exposed worker.

Prevalence and persistence of chromosomal damage and susceptible genotypes of metabolic and DNA repair genes in Chinese vinyl chloride-exposed workers.

Vinyl chloride (VC) was classified as a group 1 carcinogen by IARC in 1987. Although the relationship between VC exposure and liver cancer has been established, the mechanism of VC-related carcinogenesis remains largely unknown. Previous epidemiological studies have shown that VC exposure is associated with increased genotoxicity in humans. To explore chromosomal damage and its progression, and their association to genetic susceptibility, we investigated 402 workers exposed to VC, a 77 VC-exposed cohort and 141 unexposed subjects. We measured the frequencies of cytokinesis-block micronucleus (CBMN) to reflect chromosomal damage and conducted genotyping for six xenobiotic metabolisms and five DNA repair genes' polymorphism. Data indicate that 95% of the control workers had CBMN frequencies

[Application of double created restriction site PCR-RFLP to identify MGMT gene polymorphisms].

OBJECTIVE: To develop a proper assay for identifying single nucleotide polymorphisms( SNPs) of the MGMT gene. METHODS: PCR primers were designed by create restriction site (CRS) method, then polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was adopted to identify four SNPs in MGMT gene. RESULTS: By PCR, one primer pair yielded target products containing MGMT84 SNP site, and the other primer pair yielded target products containing MGMT143, 160, 178 SNP sites. Four restriction enzymes were adopted to identify the four SNPs, respectively. The effects of PCR and RFLP were good. CONCLUSION: The methods for four SNPs of MGMT determinated by CRS-PCR-RFLP theory could be facility, economy, and rapidness.

[Polymorphisms of FAS and FASL genes and susceptibility of silicosis].

OBJECTIVE: To explore the relationship between polymorphisms of FAS and FASL genes and genetic susceptibility of silicosis. METHODS: A case-control study was conducted. The case group was 183 male patients with silicosis and the control group was 111 male silica-exposed but without silicosis miners. Data on total dust concentrations was collected to estimate cumulative total dust exposure (CTE) of each subject and each person's characteristics and work history were obtained from questionnaire. Polymerase chain reaction re-strained fragment length polymorphism technique (PCR-RFLP) was applied to detect the single nucleotide polymorphisms (SNPs) of FAS-1377, FAS-670 and FASL-844. Associations between polymorphisms and risk of silicosis and stages, interactions between polymorphisms, between polymorphisms and CTE and smoking and haplotypes were analyzed. RESULTS: There were no differences in the FAS-1377, FAS-670 and FASL-844 genotypes between the case group and the control group (P > 0.05). No association was observed between FAS-1377, FAS-670 and FASL-844 polymorphisms and silicosis and stages (P > 0.05). The frequencies of FAS-1377G/-670G haplotype in the cases (9.6%) were higher than those in the controls (3.6%) (P < 0.05). No interactions between the polymorphisms of different genes, the gene polymorphism and the total accumulative total dust, the gene polymorphism and smoking were observed (P > 0.05). CONCLUSION: FAS-1377, FAS-670 and FASL-844 polymorphisms are not susceptible factors of silicosis. The FAS-1377G/-670G haplotype might be a susceptibility marker of silicosis.