Thyroid endocrine disruption and neurotoxicity of gestodene in adult female mosquitofish (Gambusia affinis).

The frequent detection of progestins in various aquatic environments and their potential endocrine disruptive effects in fish have attracted increasing attention worldwide. However, data on their effects on thyroid function and neurotoxicity in fish are limited, and the underlying mechanisms remain unclear. Here, the effects of gestodene (GES, a common progestin) on the thyroid endocrine and nervous systems of mosquitofish (Gambusia affinis) were studied. Adult female fish were exposed to GES at environmentally relevant concentrations (4.4-378.7 ng/L) for 60 days. The results showed that exposure to 378.7 ng/L GES caused a significant decrease in fish growth compared with the control and a marked reduction in the total distance traveled (50.6%) and swimming velocity (40.1-61.9%). The triiodothyronine (T3) levels were significantly increased by GES in a dose-dependent manner, whereas those of tetraiodothyronine (T4) were significantly decreased only at the G500 concentration. The acetylcholinesterase (AChE) activity was decreased significantly in the 4.42 ng/L GES treatments, but increased significantly at 378.67 ng/L. In the brain, a strong increase in the transcriptional levels of bdnf, trh, and dio2 was observed in fish after the 378.7 ng/L treatment. In addition, chronic exposure to GES caused colloid depletion with a concentration-dependent manner in the thyroid, and angiectasis, congestion, and vacuolar necrosis in the brain. These findings provide a better understanding of the effects of GES and associated underlying mechanisms in G. affinis.

The interactive effects of ethinylestradiol and progesterone on transcriptional expression of genes along the hypothalamus-pituitary-thyroid axis in embryonic zebrafish (Danio rerio).

Progestins and estrogens are widespread in various aquatic environments and their potential endocrine disruption effects to aquatic organisms have drawn growing concern. However, their combined effects in aquatic organisms remain elusive. The aim of the present study was to assess the effects of the binary mixtures of gestodene (GES) and 17α-ethinylestradiol (EE2) on the hypothalamic-pituitary-thyroid (HPT) axis of zebrafish (Danio rerio) using the eleuthero-embryos. Embryos were exposed to GES and EE2 alone or in combination at concentrations ranging from 41 to 5329 ng L-1 (nominal ones from 50 to 5000 ng L-1) for 48 h, 96 h and 144 h post fertilization (hpf). The results showed that the transcripts of the genes along the HPT axis displayed pronounced alterations. There was no clear pattern in the change of the transcripts of these genes over time and with concentrations. However, in general, the transcripts of the genes were inversely affected by EE2 (increase 0.5 to 4.2-folds) and GES (inhibition 0.4 to 4.9-folds), and their mixtures showed interactive effects in embryonic zebrafish. In addition, physiological data (mortality, malformation, body length and heart rate etc.) denoted higher toxicity of the two chemicals in combination than alone based on the developmental toxicity and neurotoxicity (locomotor behavior). These results indicated that the interactive effects of these two chemicals might be different between at the transcriptional level and at the whole organismal level. In summary, GES and EE2 affect the HPT axis (related genes expression and thyroid hormones (THs) levels) and exhibit developmental toxicity and neurotoxicity.

Reproductive potential of mosquitofish is reduced by the masculinizing effect of a synthetic progesterone, gestodene: Evidence from morphology, courtship behaviour, ovary histology, sex hormones and gene expressions.

The ever-increasing use of synthetic hormones, especially progestins, for medical applications has drawn growing concerns due to their potential endocrine disrupting effects that may diminish the reproductive outputs of aquatic organisms. Using mosquitofish (Gambusia affinis) as a model species, we tested whether gestodene (GES), a commonly used progestin, can alter the expressions of genes associated with sex hormone synthesis and cause ensuing changes in morphological features, courtship behaviour and oocyte development. After exposing to GES at environmentally relevant concentrations (2.96, 32.9 and 354 ng L-1) for 40 days, we found that GES, especially at 354 ng L-1, induced masculinization of female fish, indicated by the reduced body weight to length ratio and development of gonopodia (i.e. anal fins of male fish). Thus, the males showed less intimacy and mating interest towards the GES-exposed females, indicated by the reduced time spent on attending, following and mating behaviours. While oocyte development was seemingly unaffected by GES, spermatogonia were developed in the ovary. All the aforementioned masculinizing effects of GES were associated with the increased testosterone level and decreased estradiol level, driven by upregulating androgen receptor genes (Arα and Arß). Overall, our findings suggest that progestins could undermine the reproductive potential of aquatic organisms and hence their persistence in the progestin-contaminated environment.

Norethindrone alters mating behaviors, ovary histology, hormone production and transcriptional expression of steroidogenic genes in zebrafish (Danio rerio).

The impact of progestins (i.e. synthetic forms of progesterone) on aquatic organisms has drawn increasing attention due to their widespread occurrence in the aquatic environments and potential effects on the endocrine system of fish. In this study, the effects of norethindrone (NET, a progestin) on the reproductive behavior, sex hormone production and transcriptional expressions were evaluated by exposing female zebrafish to NET at 0, 3.1, 36.2 and 398.6 ng L-1 for 60 days. Results showed that NET impaired the mating behaviors of female at 36.2 and 398.6 ng L-1 exhibited by males and increased the frequency of atretic follicular cells in the ovary exposed to NET at 398.6 ng L-1. As for sex hormones, plasma testosterone concentration in zebrafish increased, while estradiol concentration decreased. Up-regulation of genes (Npr, Mpra, Mprß, Fshß, Lß, Tshb, Nis and Dio2) was detected in the brain of fish exposed to NET at 398.6 ng L-1. The transcriptional levels of genes (Esr1, Vtg1, Ar, Cyp19a, Cyp11b and Ptgs2) were generally inhibited in the ovary of zebrafish by NET at 398.6 ng L-1. Moreover, the transcripts of genes (Vtg1, Esr1, Ar and Pgr) in the liver were reduced by NET at 36.2 and 398.6 ng L-1. Our findings suggest that NET can potentially diminish the of fish populations not only by damaging their reproductive organs, but also by altering their mating behavior through the changes in the expressions of genes responsible for the production of sex hormones.

An altered TH1/TH2 and pro-inflammatory cytokine profile in patients with end-stage renal disease detected by suspension array technology.

BACKGROUND: Patients with end-stage renal disease (ESRD) have an impaired immune response with a dysregulated Th1/Th2 cytokine network. METHODS: Twelve ESRD patients on HD were enrolled, and their data of cytokines alterations were divided into pre- and post-HD groups, while data from 12 healthy volunteers served as control. Th1/Th2 and pro-inflammatory cytokines were all measured by suspension array (SA) technology with interleukin (IL)-8 detected simultaneously by ELISA. The correlation between SA technology and ELISA for IL-8 was calculated to compare these two methods. RESULTS: In ESRD patients, as compared with controls, the level of IL-10 increased just prior to HD and IL-1beta level decreased only following HD, while the levels of TNF-beta and IL-8 decreased both before and after HD. After HD, the levels of IL-1beta, IL-4, IL-8, and IL-10 in ESRD patients decreased when compared with those before HD. Statistical analysis by Spearman's rho's test showed significant correlations between SA technology and ELISA on IL-8 (p < 0.001, correlation coefficient 0.946). CONCLUSIONS: ESRD patients on HD show an altered cytokine profile with an increase in Th2 cytokine IL-10 and a decrease in Th1 cytokine TNF-beta as well as a reduction in pro-inflammatory cytokine IL-8. HD did affect cytokine profile of ESRD patients, decreasing IL-1, IL-4, IL-8, and IL-10. SA technology is useful in the detection of cytokine changes within detection limits of this technology in ESRD patients.