The osteogenic potential of ligament fibroblasts is greater in ankylosing spondylitis patients than in patients with osteoarthritis

BACKGROUND

The goal of the present study was to investigate the osteogenic potential of ligament fibroblasts from patients with ankylosing spondylitis (AS).

MATERIALS AND METHODS

Ligament fibroblasts were isolated from tissues harvested from AS patients and patients with aseptic necrosis of the femoral head (ANFH) who had undergone total hip arthroplasty (THA). Cells were cultured in osteogenic induction medium (OIM) with or without bone morphogenetic protein 2 (BMP-2) for 30 days. During this time, the levels of alkaline phosphatase (ALP) and osteocalcin (OC) were determined as markers of osteogenesis.

RESULTS

Ligament fibroblasts isolated from patients with AS exhibited significantly greater potential for differentiation than those isolated from patients with osteoarthritis (ANFH).

CONCLUSION

These findings illuminate osteogenesis as a new pathway for studying the mechanism underlying ankylosis in AS patients. Factors which cause localized stromal remodeling at the enthesis significantly influence formation of new bone and further research is required to determine the mechanisms responsible for the osteogenic potential of enthesis cells and ligament fibroblasts in AS patients.

Associations between Bisphenol A Exposure and Reproductive Hormones among Female Workers

The associations between Bisphenol-A (BPA) exposure and reproductive hormone levels among women are unclear. A cross-sectional study was conducted among female workers from BPA-exposed and unexposed factories in China. Women’s blood samples were collected for assay of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17β-Estradiol (E2), prolactin (PRL), and progesterone (PROG). Their urine samples were collected for BPA measurement. In the exposed group, time weighted average exposure to BPA for an 8-h shift (TWA8), a measure incorporating historic exposure level, was generated based on personal air sampling. Multiple linear regression analyses were used to examine linear associations between urine BPA concentration and reproductive hormones after controlling for potential confounders. A total of 106 exposed and 250 unexposed female workers were included in this study. A significant positive association between increased urine BPA concentration and higher PRL and PROG levels were observed. Similar associations were observed after the analysis was carried out separately among the exposed and unexposed workers. In addition, a positive association between urine BPA and E2 was observed among exposed workers with borderline significance, while a statistically significant inverse association between urine BPA and FSH was observed among unexposed group. The results suggest that BPA exposure may lead to alterations in female reproductive hormone levels.

Gestational Weight Gain Trend and Population Attributable Risks of Adverse Fetal Growth Outcomes in Ohio

BACKGROUND

The trend of gestational weight gain (GWG) in relation to the Institute of Medicine (IOM) guidelines and the population attributable risks (PARs) of GWG on fetal growth outcomes remain unclear.

METHODS

We analysed Ohio birth certificates from 2006 to 2012 to examine GWG trend by prepregnancy body mass index, to calculate the risk of small- and large-for-gestational age (SGA and LGA), and macrosomia (birthweight >4000 g or >4500 g) infants, and to estimate the PARs of GWG below or above the guidelines.

RESULTS

Of 869,531 women who delivered singleton live births at 22-44 weeks of gestation, 4.5% were underweight, 48.9% were normal weight, 23.9% were overweight, and 22.7% were obese before pregnancy. About 36.5% of underweight, 52.6% of normal weight, 72.5% of overweight, and 62.4% of obese women gained weight above the guidelines, with only slight changes from 2006 to 2012. Also, 34.9% of underweight, 20.1% of normal weight, 16.3% of overweight, and 27.0% of obese women gained weight below the guidelines. The PAR of GWG below or above the guidelines was -13% for SGA, 32.6% for LGA, 28.1% for macrosomia >4000 g, and 48.3% for macrosomia >4500 g, mostly driven by currently GWG above the guidelines in normal weight, overweight, and obese women.

CONCLUSIONS

A high percentage of pregnant women gained weight outside of the current IOM GWG guidelines; however, changes from 2006 to 2012 were small. GWG above the IOM guidelines significantly contributed to a large proportion of LGA and macrosomic infants in the general population.

Alteration of sperm protein profile induced by cigarette smoking

Cigarette smoking is associated with lower semen quality, but how cigarette smoking changes the semen quality remains unclear. The aim of this study was to screen the differentially expressed proteins in the sperm of mice with daily exposure to cigarette smoke. The 2D gel electrophoresis (2DE) and mass spectrometry (MS) analyses results showed that the mouse sperm protein profile was altered by cigarette smoking. And 22 of the most abundant proteins that correspond to differentially expressed spots in 2DE gels of the sperm samples were identified. These proteins were classified into different groups based on their functions, such as energy metabolism, reproduction, and structural molecules. Furthermore, the 2DE and MS results of five proteins (Aldoa, ATP5a1, Gpx4, Cs, and Spatc1) were validated by western blot analysis and reverse transcriptase-polymerase chain reaction. Results showed that except Spatc1 the other four proteins showed statistically significant different protein levels between the smoking group and the control group (P < 0.05). The expressions of three genes (Aldoa, Gpx4, and Spatc1) were significantly different (P < 0.05) at transcription level between the smoking group and the control group. In addition, five proteins (Aldoa, ATP5a1, Spatc1, Cs, and Gpx4) in human sperm samples from 30 male smokers and 30 non-smokers were detected by western blot analysis. Two proteins (Aldoa and Cs) that are associated with energy production were found to be significantly altered, suggesting that these proteins may be potential diagnostic markers for evaluation of smoking risk in sperm. Further study of these proteins may provide insight into the pathogenic mechanisms underlying infertility in smoking persons.

Exposure to bisphenol-A and reproductive hormones among male adults

BACKGROUND

Bisphenol A (BPA) is a suspected human endocrine disruptor which is widely used.

METHODS

In order to determine whether urine BPA level is associated with serum reproductive hormone levels among male adults, we carried out a cross-sectional study in China. We recruited 592 male workers and collected their urine samples for BPA measurement. We also collected blood samples and examined serum reproductive hormones. We used multiple linear regression and log-binomial model to examine associations between urine BPA level and hormone levels after controlling for age and smoking status.

RESULTS

An increased urine BPA level was associated with increased prolactin (p<0.001), estradiol (p<0.001), sex hormone-binding globulin level (p=0.001), and a reduced androstenedione (p<0.001) and free androgen index level (p=0.021). Males, whose urine BPA level was in the 2nd, 3rd and highest quartiles, had respectively 1.58, 1.33 and 3.09-fold increased prevalence of having a high prolactin level (>P75 level). The highest quartile of BPA level was associated with 1.63 and 1.50-fold increased prevalence of having a high estradiol and elevated sex hormone-binding globulin level. Males with higher quartile of BPA level had a lower inhibin B level.

CONCLUSION

High BPA exposure is associated with increased prolactin, estradiol and sex hormone-binding globulin level in males, and may contribute to male infertility.

Another functional frame-shift polymorphism of DEFB126 (rs11467497) associated with male infertility

DEFB126 rs140685149 mutation was shown to cause sperm dysfunction and subfertility. Indel rs11467497 is another 4-nucleotide frame-shift mutation (151bp upstream of rs140685149) that leads to the premature termination of translation and the expression of peptide truncated at the carboxyl terminus. In the present study, we performed a comprehensive association study to check the contribution of rs140685149 and rs11467497 to male infertility. Our results confirmed the previous findings that there was no association between rs140685149 and sperm motility. In contrast, we found a significant association of another indel rs11467497 with male infertility. Moreover, rs11467497 was shown to be associated with higher number of round cells in the infertile males with low sperm motility. Surprisingly, the two mutations commonly existed in the sperm donors (n = 672), suggesting a potential application of the two indels in the screening for eligible sperm donors. Western blotting assays showed the sperms with rs140685149 2-nt deletion tended to have unstable DEFB126 protein in contrast of no DEFB126 protein expressed in the sperms with rs11467497 4-nt deletion, suggesting a more severe consequence caused by rs11467497 mutation. In conclusion, our study presented a significant contribution of another functional frame-shift polymorphism of DEFB126 (rs11467497) to male infertility.

Association between body fat distribution and androgen deficiency in middle-aged and elderly men in China

The objective of the present study was to examine the association between body fat distribution and total testosterone (TT) and free testosterone (FT) levels among middle-aged and elderly men. A total of 922 male residents aged 40-70 years from a community in Shanghai, China, participated in the study. Their waist circumference (WC), waist-height ratio (WHtR), body mass index (BMI), and TT and FT concentrations were measured. Logistic regression models were used to estimate testosterone deficiency risk on the basis of anthropometric indices. BMI, WC and WHtR were all associated with TT deficiency. The participants in the highest quartiles of above-mentioned anthropometric indices had the highest risk of TT deficiency (BMI: odds ratio (OR)=4.40, 95% confidence interval (CI)=2.69-7.19; WC: OR=3.47, 95% CI=2.14-5.60; WHtR: OR=2.89, 95% CI=1.76-4.76). WC and WHtR were associated with FT deficiency. The participants in the highest quartiles had the highest risk of FT deficiency (WC: OR=1.87, 95% CI=1.18-2.97; WHtR: OR=1.67, 95% CI=1.04-2.66). The association between BMI and FT deficiency was not statistically significant (OR=1.21 for the highest quartile, 95% CI=0.78-1.87). Our study demonstrated that both general and abdominal obesity were associated with TT deficiency, whereas only abdominal obesity was found to be associated with FT deficiency.

LINE-1 hypomethylation in spermatozoa is associated with Bisphenol A exposure

Bisphenol A (BPA) is an endocrine disruptor with potentially harmful effects on humans. However, epigenetic mechanisms that modulate the effects of BPA remain unclear. Methylation of long interspersed nucleotide elements (LINE-1) is a marker of genome-wide methylation status. This study aims to examine whether BPA exposure was associated with LINE-1 methylation changes in men. Male factory workers in Hunan, China (N = 149) were studied, 77 with BPA exposure in workplace (BPA-exposed group) and 72 without BPA exposure in workplace (control group). Pre-shift and post-shift urine samples were collected from the BPA-exposed group and spot urine samples were collected from the control group. Urine samples were assessed for BPA. In addition, blood and semen samples were collected from both groups for LINE-1 methylation analysis. In multivariate analysis adjusted for age, education, smoking habits and alcohol consumption, sperm LINE-1 methylation level was significantly lower in BPA exposed workers (p < 0.001) compared to that in the unexposed workers. Linear regression analysis also showed that log-transformed urine BPA levels were inversely associated with sperm LINE-1 methylation (p < 0.0001), but not peripheral blood cell LINE-1 methylation. Moreover, the association between urine BPA level and semen quality was not attenuated after adjustments for LINE-1 level. In summary, the observed independent relationship between BPA exposure and LINE-1 methylation may have public health implications on reproductive health in men because of ubiquitous exposure to BPA.

In utero exposure to bisphenol-A and its effect on birth weight of offspring

To examine the effect of in utero BPA exposure on the birth weight of offspring, a total of 587 children from families in which parent(s) did or did not have occupational exposure to BPA were examined. Their birth weights were obtained by an in-person interview of the mother. Parental BPA exposure level during the index pregnancy was determined through personal air sampling measurements and exposure history. After controlling for potential confounders, parental exposure to BPA in the workplace during pregnancy was associated with decreased birth weight. The association was stronger for maternal exposure which is statistically significant (P=0.02). A dose-response relationship was observed with increased BPA exposure levels in pregnancy associated with greater magnitude of decrease of birth weight in offspring (P=0.003). Our findings provide the new epidemiologic evidence suggesting that in utero exposure to BPA during pregnancy may be associated with decreased birth weight in offspring.

The Presence of Hepatitis B Surface Antigen in the Ova of Pregnant Women and Its Relationship with Intra-Uterine Infection by Hepatitis B Virus

Vertical transmission of hepatitis B virus (HBV) has been proposed to play an important role in mother-to-child transmission, although the extent to which vertical transmission via oocytes contributes to neonatal HBV infection remains unknown. Ovarian biopsies were collected during caesarean sections in 68 clinically asymptomatic pregnant women who were carriers of HBV. The presence of hepatitis B surface antigen (HBsAg) in the ova of pregnant women was determined by immunohistochemistry. Serum markers of HBV infection in pregnant women and their neonates were analysed. It was found that, of 68 women, the ova were positive for HBsAg in only one woman and her neonate was negative for any serum HBV markers 3 days after birth. Of 68 neonates, one was positive for serum HBV markers 3 days after birth and his mother's ova were negative for HBsAg. These findings indicate that vertical transmission via oocytes may not be the major route of HBV intra-uterine infection.

Bisphenol A levels in blood and urine in a Chinese population and the personal factors affecting the levels

The objective of the study was to describe the background bisphenol A (BPA) levels in urine and serum of a Chinese population without occupational exposure and to examine the personal characteristics influencing these levels. Workers from 10 factories and their family members were recruited and their peripheral blood and spot urine samples were collected. The conjugated and free BPA of the samples was assayed with high-performance liquid chromatography. The exposure levels were checked with 2-independent-samples test, and the potential personal factors influencing exposure levels were analyzed using nonlinear correlation. Of the total of 952 subjects participating in the study, urine and blood samples were taken from 97% and 93% of them, respectively. The detectable rates were 50% for urine samples and 17% for serum samples, given the detection limit of 0.31 microg/L for urine and 0.39 microg/L for serum. The arithmetic mean (AM) and geometric mean (GM) of non-creatinine-adjusted urinary BPA level were 10.45 and 0.87 microg/L, which became 24.93 and 0.38 microg/g Cr after the creatinine level was adjusted; serum BPA levels were 2.84 microg/L (AM) and 0.18 microg/L (GM). Males and those with smoking habit had higher biological burden of BPA. The results indicated that half of the study subjects had detectable BPA in their urine samples. BPA levels were influenced by gender and smoking status. The sources of non-occupational BPA exposures should be explored.

Differential expression of two tropoelastin genes in zebrafish

Elastin is the extracellular matrix protein responsible for properties of extensibility and elastic recoil in large blood vessels, lung and skin of most vertebrates. Elastin is synthesized as a monomer, tropoelastin, but is rapidly transformed into its final polymeric form in the extracellular matrix. Until recently information on sequence and developmental expression of tropoelastins was limited to mammalian and avian species. We have recently identified and characterized two expressed tropoelastin genes in zebrafish. This was the first example of a species with multiple tropoelastin genes, raising the possibility of differential expression and function of these tropoelastins in elastic tissues of the zebrafish. Here we have investigated the temporal expression and tissue distribution of the two tropoelastin genes in developing and adult zebrafish. Expression was detected early in skeletal cartilage structures of the head, in the developing outflow tract of the heart, including the bulbus arteriosus and the ventral aorta, and in the wall of the swim bladder. While the temporal pattern of expression was similar for both genes, the upregulation of eln2 was much stronger than that of eln1. In general, both genes were expressed and their gene products deposited in most of the elastic tissues examined, with the notable exception of the bulbus arteriosus in which eln2 expression and its gene product was predominant. This finding may represent a sub-specialization of eln2 to provide the unique architecture of elastin and the specific mechanical properties required by this organ.