GCY-20 signaling controls suppression of Caenorhabditis elegans egg laying by moderate cold.

Organisms sensing environmental cues and internal states and integrating the sensory information to control fecundity are essential for survival and proliferation. The present study finds that a moderate cold temperature of 11°C reduces egg laying in Caenorhabditis elegans. ASEL and AWC neurons sense the cold via GCY-20 signaling and act antagonistically on egg laying through the ASEL and AWC/AIA/HSN circuits. Upon cold stimulation, ASEL and AWC release glutamate to activate and inhibit AIA interneurons by acting on highly and lowly sensitive ionotropic GLR-2 and GLC-3 receptors, respectively. AIA inhibits HSN motor neuron activity via acetylcholinergic ACR-14 receptor signaling and suppresses egg laying. Thus, ASEL and AWC initiate and reduce the cold suppression of egg laying. ASEL's action on AIA and egg laying dominates AWC's action. The biased opposite actions of these neurons on egg laying provide animals with a precise adaptation of reproductive behavior to environmental temperatures.

Paternal lipopolysaccharide exposure induced intrauterine growth restriction via the inactivation of placental MEST/PI3K/AKT pathway in mice.

Maternal lipopolysaccharide (LPS) exposure during pregnancy has been related to IUGR. Here, we explored whether paternal LPS exposure before mating impaired fetal development. All male mice except controls were intraperitoneally injected with LPS every other day for a total of five injections. The next day after the last LPS, male mice were mated with untreated female mice. Interestingly, fetal weight and crown-rump length were reduced, while the incidence of IUGR was increased in paternal LPS exposure group. Additionally, paternal LPS exposure leaded to poor placental development through causing cell proliferation inhibition and apoptosis. Additional experiment demonstrated that the inactivation of placental PI3K/AKT pathway might be involved in paternal LPS-induced cell proliferation inhibition and apoptosis of trophoblast cells. Furthermore, the mRNA and protein levels of mesoderm specific transcript (MEST), a maternally imprinted gene with paternal expression, were significantly decreased in mouse placentas from paternal LPS exposure. Further analysis showed that paternal LPS exposure caused the inactivation of placental PI3K/AKT pathway and then cell proliferation inhibition and apoptosis might be via down-regulating placental MEST. Overall, our results provide evidence that paternal LPS exposure causes poor placental development and subsequently IUGR may be via down-regulating MEST/PI3K/AKT pathway, and then inducing cell proliferation inhibition and apoptosis in placentas.

Cholic acid exposure during late pregnancy causes placental dysfunction and fetal growth restriction by reactive oxygen species-mediated activation of placental GCN2/eIF2α pathway.

Epidemiological studies suggest that fetal growth restriction (FGR) caused by gestational cholestasis is associated with elevated serum cholic acid (CA). Here, we explore the mechanism by which CA induces FGR. Pregnant mice except controls were orally administered with CA daily from gestational day 13 (GD13) to GD17. Results found that CA exposure decreased fetal weight and crown-rump length, and increased the incidence of FGR in a dose-dependent manner. Furthermore, CA caused placental glucocorticoid (GC) barrier dysfunction via down-regulating the protein but not the mRNA level of placental 11ß-Hydroxysteroid dehydrogenase-2 (11ß-HSD2). Additionally, CA activated placental GCN2/eIF2α pathway. GCN2iB, an inhibitor of GCN2, significantly inhibited CA-induced down-regulation of 11ß-HSD2 protein. We further found that CA caused excessive reactive oxygen species (ROS) production and oxidative stress in mouse placentas and human trophoblasts. NAC significantly rescued CA-induced placental barrier dysfunction by inhibiting activation of GCN2/eIF2α pathway and subsequent down-regulation of 11ß-HSD2 protein in placental trophoblasts. Importantly, NAC rescued CA-induced FGR in mice. Overall, our results suggest that CA exposure during late pregnancy induces placental GC barrier dysfunction and subsequent FGR may be via ROS-mediated placental GCN2/eIF2α activation. This study provides valuable insight for understanding the mechanism of cholestasis-induced placental dysfunction and subsequent FGR.

Gestational cholestasis induced intrauterine growth restriction through triggering IRE1α-mediated apoptosis of placental trophoblast cells.

Epidemiological and animal experimental studies suggest an association between gestational cholestasis and intrauterine growth restriction (IUGR). Here, we explored the mechanism through which gestational cholestasis induced IUGR. To establish gestational cholestasis model, pregnant mice were subcutaneously injected with 17α-Ethynylestradiol (E2) on gestational day 13 (GD13)-GD17. Some pregnant mice were intraperitoneally injected with 4µ8C on GD13-GD17. The results found that the apoptosis of trophoblast cells was elevated in placentas of mice with gestational cholestasis and in deoxycholic acid (DCA)-treated human trophoblast cell lines and primary mouse trophoblast cells. Correspondingly, the levels of placental cleaved caspase-3 and Bax were increased, while placental Bcl2 level was decreased in mice with gestational cholestasis and in DCA-treated trophoblast cells. Further analysis found that placental IRE1α pathway was activated in mice with gestational cholestasis and in DCA-treated trophoblast cells. Interestingly, 4µ8C, an IRE1α RNase inhibitor, significantly inhibited caspase-3 activity and apoptosis of trophoblast cells in vivo and in vitro. Importantly, 4µ8C rescued gestational cholestasis-induced placental insufficiency and IUGR. Furthermore, a case-control study demonstrated that placental IRE1α and caspase-3 pathways were activated in cholestasis cases. Our results provide evidence that gestational cholestasis induces placental insufficiency and IUGR may be via triggering IRE1α-mediated apoptosis of placental trophoblast cells.

Paternal exposure to microcystin-LR induces fetal growth restriction partially through inhibiting cell proliferation and vascular development in placental labyrinth.

Microcystin-leucine arginine (MC-LR) has reproductive and developmental toxicities. Previous studies indicated that gestational exposure to MC-LR induced fetal growth restriction in mice. The aim of this study was to further evaluate the effect of paternal MC-LR exposure before mating on fetal development. Male mice were intraperitoneally injected with either normal saline or MC-LR (10 µg/kg) daily for 35 days. Male mouse was then mated with female mice with 1:1 ratio. There was no significant difference on the rates of mating and pregnancy between MC-LR-exposed male mice and controls. Body weight and crown-rump length were reduced in fetuses whose fathers were exposed to MC-LR. Despite no difference on relative thickness of labyrinthine layer, cell proliferation, as measured by Ki67 immunostaining, was reduced in labyrinth layer of MC-LR-exposed mice. Moreover, blood sinusoid area in labyrinth layer was decreased in the fetus whose father was exposed to MC-LR before mating. Correspondingly, cross-sectional area of CD34-positive blood vessel in labyrinth layer was lower in fetuses whose fathers were exposed to MC-LR than in controls. These results provide evidence that paternal MC-LR exposure before mating induces fetal growth restriction partially through inhibiting cell proliferation and vascular development in labyrinth layer.

Tauroursodeoxycholic acid alleviates pulmonary endoplasmic reticulum stress and epithelial-mesenchymal transition in bleomycin-induced lung fibrosis.

BACKGROUND: Several studies demonstrate that endoplasmic reticulum (ER) stress-mediated epithelial-mesenchymal transition (EMT) is involved in the process of bleomycin (BLM)-induced pulmonary fibrosis. Tauroursodeoxycholic acid (TUDCA), a bile acid with chaperone properties, is an inhibitor of ER stress. This study aimed to investigate the preventive effects of TUDCA on BLM-induced EMT and lung fibrosis. METHODS: The model of lung fibrosis was established by intratracheal injection with a single dose of BLM (3.0 mg/kg). In TUDCA + BLM group, mice were intraperitoneally injected with TUDCA (250 mg/kg) daily. RESULTS: BLM-induced alveolar septal destruction and inflammatory cell infiltration were alleviated by TUDCA. BLM-induced interstitial collagen deposition, as determined by Sirius Red staining, was attenuated by TUDCA. BLM-induced elevation of pulmonary α-smooth muscle actin (α-SMA) and reduction of pulmonary E-cadherin were attenuated by TUDCA. BLM-induced pulmonary Smad2/3 phosphorylation was suppressed by TUDCA. BLM-induced elevation of Ki67 and PCNA was inhibited by TUDCA in mice lungs. In addition, BLM-induced elevation of HO-1 (heme oxygenase-1) and 3-NT (3-nitrotyrosine) was alleviated by TUDCA. Finally, BLM-induced upregulation of pulmonary GRP78 and CHOP was attenuated by TUDCA. CONCLUSIONS: These results provide evidence that TUDCA pretreatment inhibits Smad2/3-medited EMT and subsequent lung fibrosis partially through suppressing BLM-induced ER stress and oxidative stress.

Microcystin-LR inhibits testosterone synthesis via reactive oxygen species-mediated GCN2/eIF2α pathway in mouse testes.

Previous studies demonstrated that microcystin-leucine-arginine (MC-LR) disrupted testosterone (T) synthesis, but the underlying mechanisms are not entirely elucidated. This study aims to explore the role of reactive oxygen species (ROS)-mediated GCN2/eIF2α activation on MC-LR-induced disruption of testicular T synthesis. Male mice were intraperitoneally injected with MC-LR (0 or 20 µg/kg) daily for 5 weeks. Serum T was decreased in MC-LR-exposed mice (0.626 ± 0.122 vs 24.565 ± 8.486 ng/ml, P < 0.01), so did testicular T (0.667 ± 0.15 vs 8.317 ± 1.387 ng/mg protein, P < 0.01). Steroidogenic proteins including StAR, CYP11A1 and CYP17A1 were downregulated in MC-LR-exposed mouse testes and TM3 cells. Mechanistically, p-GCN2 and p-eIF2α were elevated in MC-LR-exposed TM3 cells. GCN2iB attenuated MC-LR-induced GCN2 and eIF2α phosphorylation in TM3 cells. Moreover, GCN2iB attenuated MC-LR-induced downregulation of steroidogenic proteins in TM3 cells. Further analysis found that cellular ROS were elevated and HO-1 was upregulated in MC-LR-exposed TM3 cells. PBN rescued MC-LR-induced activation of GCN2/eIF2α signaling in TM3 cells. Additionally, pretreatment with PBN attenuated MC-LR induced downregulation of steroidogenic proteins and synthases in TM3 cells. These results suggest that ROS-mediated GCN2/eIF2α activation contributes partially to MC-LR-caused downregulation of steroidogenic proteins and synthases. The present study provides a new clue for understanding the mechanism of MC-LR-induced endocrine disruption.

Supplementation with high-dose cholecalciferol throughout pregnancy induces fetal growth restriction through inhibiting placental proliferation and trophoblast epithelial-mesenchymal transition.

Vitamin D deficiency has been associated with adverse pregnant outcomes. Several studies investigated the effects of maternal vitamin D3 supplementation on fetal development with inconsistent results. The aim of this study was to investigate the effects of maternal supplementation with different doses of vitamin D3 on fetal development. Pregnant mice were administered with different doses of cholecalciferol (0, 2,000, 10,000, 40,000 IU/kg/day) by gavage throughout pregnancy. Fetal weight and crown-rump length were measured. Placental proliferation and mesenchymal characteristics were detected. HTR-8/SVneo cells were incubated in the absence or presence of calcitriol (500 nmol/L) to evaluate the effects of active vitamin D3 on migration and invasion of human trophoblast cells. Although a low dose of cholecalciferol was safe, fetal weight and crown-rump length were decreased in dams treated with high-dose cholecalciferol throughout pregnancy. Placental weight and labyrinth thickness were reduced in mice administered with high-dose cholecalciferol. An obvious calcification was observed in placentae of mice administered with high-dose cholecalciferol. Ki67-positive cells, a marker of placental proliferation, were reduced in mice administered with high-dose cholecalciferol. N-cadherin and vimentin, two mesenchymal markers, were decreased in cholecalciferol-treated mouse placentae and calcitriol-treated human trophoblast cells. MMP-2 and MMP-9, two matrix metalloproteinases, were downregulated in cholecalciferol-treated mouse placentae and calcitriol-treated human trophoblast cells. In addition, trophoblast migration and invasion were suppressed by calcitriol. Supplementation with high-dose cholecalciferol induces fetal growth restriction partially through inhibiting placental proliferation and trophoblast epithelial-mesenchymal transition.

Di-(2-ethylhexyl) phthalate induces testicular endoplasmic reticulum stress and germ cell apoptosis in adolescent mice.

Di-(2-ethylhexyl) phthalate (DEHP) is a male reproductive toxicant. This research is aimed at investigating the effect of pubertal DEHP exposure on testicular endoplasmic reticulum (ER) stress and germ cell apoptosis. Five-week-old male mice were orally administered with DEHP (0, 0.5, 50, or 500 mg/kg/day) for 35 days. Testis weight and sperm count were reduced in mice exposed to 500 mg/kg/day DEHP. The number of seminiferous tubules in stages VII-VIII, mature seminiferous tubules, was reduced and the number of seminiferous tubules in stages IX-XII, immature seminiferous tubules, was elevated in mice treated with 500 mg/kg/day DEHP. Numerous apoptotic germ cells were observed in mouse seminiferous tubules exposed to 50 and 500 mg/kg/day DEHP. Moreover, cleaved caspase-3 was elevated in mouse testes exposed to 500 mg/kg/day DEHP. In addition, Bcl-2 was reduced and Bax/Bcl-2 was elevated in mouse testes exposed to 500 mg/kg/day DEHP. Additional experiment showed that GRP78, an ER molecular chaperone, was downregulated in mouse testes exposed to 500 mg/kg/day DEHP. Testicular p-IRE-1α, p-JNK, and CHOP, three markers of ER stress, were upregulated in mice exposed to 500 mg/kg/day DEHP. These results suggest that pubertal exposure to high doses of DEHP induces germ cell apoptosis partially through initiating ER stress in testes.

Long-term vitamin D deficiency promotes renal fibrosis and functional impairment in middle-aged male mice.

Renal fibrosis is common especially in the elderly population. Recently, we found that vitamin D deficiency caused prostatic hyperplasia. This study aimed to investigate whether vitamin D deficiency promotes renal fibrosis and functional impairment. All mice except controls were fed with vitamin D-deficient (VDD) diets, beginning from their early life. The absolute and relative kidney weights on postnatal week 20 were decreased in VDD diet-fed male pups but not in female pups. A mild pathological damage was observed in VDD diet-fed male pups but not in females. Further analysis showed that VDD-induced pathological damage was aggravated, accompanied by renal dysfunction in 40-week-old male pups. An obvious collagen deposition was observed in VDD diet-fed 40-week-old male pups. Moreover, renal α-smooth muscle actin (α-SMA), a marker of epithelial-mesenchymal transition (EMT), and Tgf-ß mRNA were up-regulated. The in vitro experiment showed that 1,25-dihydroxyvitamin D3 alleviated transforming growth factor-ß1 (TGF-ß1)-mediated down-regulation of E-cadherin and inhibited TGF-ß1-evoked up-regulation of N-cadherin, vimentin and α-SMA in renal epithelial HK-2 cells. Moreover, 1,25-dihydroxyvitamin D3 suppressed TGF-ß1-evoked Smad2/3 phosphorylation in HK-2 cells. These results provide experimental evidence that long-term vitamin D deficiency promotes renal fibrosis and functional impairment, at least partially, through aggravating TGF-ß/Smad2/3-mediated EMT in middle-aged male mice.

Environmental exposure to cadmium impairs fetal growth and placental angiogenesis via GCN-2-mediated mitochondrial stress.

Cadmium (Cd), a well-known environmental pollutant, can lead to placental insufficiency and fetal growth restriction. However, the underlying mechanism is unknown. The purpose of our study is to explore the effect of Cd on placental angiogenesis and its mechanism using in vitro and in vivo models. Results found that gestational Cd exposure obviously decreased placental weight and impaired placental vascular development in mice. Correspondingly, Cd exposure evidently downregulated the expression of VEGF-A protein (a key indicator of angiogenesis) and progesterone receptor (PR) in placental trophoblasts. Further experiment showed that lentivirus PR overexpression reversed Cd-caused the reduction of VEGF-A level in human placental trophoblasts. In addition, Cd significantly reduced progesterone level, down-regulated the expression of key progesterone synthase (StAR, CYP11A1), and activated mitochondrial stress response and GCN-2/p-eIF2α signaling in placental trophoblasts. Additional experiment showed that GCN-2 siRNA pretreatment markedly alleviated Cd-activated mitochondrial stress response, restored Cd-downregulated the expression of CYP11A1, reversed Cd-reduced the level of progesterone and VEGF-A in human placental trophoblasts. Finally, our case-control study confirmed that impaired placental angiogenesis and reduced progesterone level occurred in all-cause small for gestational age placenta. Taken together, environmental exposure to Cd impairs fetal growth and placental angiogenesis via GCN-2-mediated mitochondrial stress.

Low Vitamin D Status Is Associated with Inflammation in Patients with Chronic Obstructive Pulmonary Disease.

Vitamin D deficiency is associated with increased risks of chronic obstructive pulmonary disease (COPD). Nevertheless, the mechanisms remain unknown. This study analyzed the correlations between vitamin D levels and inflammation in COPD patients. One hundred and one patients with COPD and 202 control subjects were enrolled. Serum 25(OH)D level and inflammatory cytokines were detected. Serum 25(OH)D was decreased and inflammatory cytokines were increased in COPD patients. According to forced expiratory volume in 1 s, COPD patients were divided into three grades. Furthermore, serum 25(OH)D was gradually decreased in COPD patients ranging from grade 1-2 to 4. Serum 25(OH)D was inversely associated with inflammatory cytokines in COPD patients. Further analysis found that NF-κB and AP-1 signaling were activated in COPD patients. Besides, inflammatory signaling was gradually increased in parallel with the severity of COPD. By contrast, pulmonary nuclear vitamin D receptor was decreased in COPD patients. In vitro experiments showed that 1,25(OH)2D3 inhibited LPS-activated inflammatory signaling in A549 cells (human lung adenocarcinoma cell). Mechanically, 1,25(OH)2D3 reinforced physical interactions between vitamin D receptor with NF-κB p65 and c-Jun. Our results indicate that vitamin D is inversely correlated with inflammatory signaling in COPD patients. Inflammation may be a vital mediator of COPD progress in patients with low vitamin D levels.

Signal Decoding for Glutamate Modulating Egg Laying Oppositely in Caenorhabditis elegans under Varied Environmental Conditions.

Animals' ability to sense environmental cues and to integrate this information to control fecundity is vital for continuing the species lineage. In this study, we observed that the sensory neurons Amphid neuron (ASHs and ADLs) differentially regulate egg-laying behavior in Caenorhabditis elegans under varied environmental conditions via distinct neuronal circuits. Under standard culture conditions, ASHs tonically release a small amount of glutamate and inhibit Hermaphrodite specific motor neuron (HSN) activities and egg laying via a highly sensitive Glutamate receptor (GLR)-5 receptor. In contrast, under Cu2+ stimulation, ASHs and ADLs may release a large amount of glutamate and inhibit Amphid interneuron (AIA) interneurons via low-sensitivity Glutamate-gated chloride channel (GLC)-3 receptor, thus removing the inhibitory roles of AIAs on HSN activity and egg laying. However, directly measuring the amount of glutamate released by sensory neurons under different conditions and assaying the binding kinetics of receptors with the neurotransmitter are still required to support this study directly.

Prevalence and risk factors of intrahepatic cholestasis of pregnancy in a Chinese population.

Studies on the risk factors for intrahepatic cholestasis of pregnancy (ICP) in a population-based cohort are lacking. We assess the prevalence and risk factors of ICP in a Chinese population. In this study, a cohort study was conducted that included 12,200 eligible pregnant women. The overall incidence of ICP in this cohort was 6.06%. With increasing maternal age, the incidence of ICP decreased in women younger than 30 years of age but increased in those older than 30. With increasing pre-pregnancy BMI, the incidence of ICP decreased if the pre-pregnancy BMI was less than 23 kg/m2 but increased if it was 23 kg/m2 or higher. Further analysis showed that the risk of ICP increased when maternal age was < 25 years (Adjusted RR 2.01; 95% CI 1.64-2.47) or ≥ 35 years (Adjusted RR 1.34; 95% CI 1.02-1.76). Furthermore, an increased risk of ICP was associated with pre-pregnancy underweight (adjusted RR 1.27; 95% CI 1.04-1.56), inadequate gestational weight gain (GWG) (adjusted RR 1.58; 95% CI 1.28-1.96), lower maternal education (adjusted RR 2.96; 95% CI 2.35-3.74), multiparity (adjusted RR 1.54; 95% CI 1.23-1.93), and twin/multiple pregnancies (adjusted RR 2.12; 95% CI 1.25-3.58). Maternal age (< 25 or ≥ 35 years), underweight, inadequate GWG, lower maternal education, multiparity, and twin/multiple pregnancies were identified as risk factors of ICP.

Gestational vitamin D deficiency causes placental insufficiency and fetal intrauterine growth restriction partially through inducing placental inflammation.

Several epidemiological studies suggest an association between vitamin D deficiency (VDD) and fetal intrauterine growth restriction (IUGR). Here, we explored the mechanism through which VDD induced fetal IUGR. Pregnant mice were fed with VDD diet to establish VDD model. Cyp27b1+/- mice were generated to develop a model of active vitamin D3 deficiency. Cyp27b1+/- mice were injected with either 1α,25(OH)2D3 or vehicle once a day throughout pregnancy. As expected, fetal weight and crown-rump length were reduced in VDD diet-fed mice. Correspondingly, fetal weight and crown-rump length were lower in cyp27b1+/- mice. 1α,25(OH)2D3 elevated fetal weight and crown-rump length, and protected cyp27b1+/- mice from fetal IUGR. Further analysis found that placental proliferation was inhibited and placental weight was decreased in VDD diet-fed mice. Several growth factors and nutrient transfer pumps were downregulated in the placentas of VDD diet-fed mice. Mechanistically, several inflammatory cytokines were upregulated and placental NF-κB was activated not only in VDD diet-fed mice but also in VDD pregnant women. Interestingly, 1α,25(OH)2D3 inhibited the downregulated of placental nutrient transfer pumps and the upregulated of placental inflammatory cytokines in Cyp27b1+/- mice. These results provide experimental evidence that gestational VDD causes placental insufficiency and fetal IUGR may be through inducing placental inflammation.

Continuous association of total bile acid levels with the risk of small for gestational age infants.

The association between maternal serum total bile acid (TBA) levels and small-for-gestational-age (SGA) infants is unclear. We investigated the association between various degrees of serum TBA levels and the risk of SGA infants in a Chinese population. The current study performed a cohort study among 11811 mothers with singleton pregnancy. Subjects were divided into seven categories according to maternal serum TBA levels. Interestingly, birth sizes were reduced, whereas the rate of SGA infants was increased across increasing categories of serum TBA. Compared to category 1, adjusted ORs (95%CI) for SGA infants were 0.99 (0.82-1.21) in category 2, 1.22 (0.97-1.53) in category 3, 1.99 (1.53-2.58) in category 4, 2.91 (2.16-3.93) in category 5, 4.29 (3.33-5.54) in category 6, and 9.01 (5.99-13.53) in category 7, respectively. Furthermore, adjusted ORs (95%CI) for SGA infants for each 1-SD increase in serum TBA levels were 1.36 (1.29-1.43) among all subjects, 2.40 (1.82-3.45) among subjects without cholestasis, and 1.13 (1.06-1.22) among subjects with cholestasis, respectively. These results suggest that gestational cholestasis increases the risk of SGA infants. Additionally, our results indicate strong, continuous associations of serum TBA levels below those diagnostic of cholestasis with a decreased birth sizes and an increased risk of SGA infants.

Gestational vitamin D deficiency impairs fetal lung development through suppressing type II pneumocyte differentiation.

Gestational vitamin D deficiency is associated with pulmonary diseases. This study aimed to investigate the effect of gestational vitamin D deficiency on fetal lung development in mice. Absolute and relative weights of fetal lungs were reduced in vitamin D deficient (VDD) group. Incrassate mesenchyme, measured by septal wall thickness, accompanied by lessened saccular space, was shown in VDD group. Numerous immature type II pneumocytes, as determined by PAS staining, were observed in VDD group. Moreover, increased Ki67-positive cells, a marker of cell proliferation, was detected in VDD group. The additional experiments showed that Sftpa, Sftpb, Sftpc and Sftpd, four surfactant genes, were downregulated and pro-surfactant protein B was reduced in VDD group. FoxA1, FoxA2 and TTF-1, three transcription factors that regulate surfactant genes, and VEGF, a key regulator for pulmonary maturation, were downregulated in VDD group. These results suggest that gestational vitamin D deficiency impairs fetal lung development partially through suppressing type II pneumocyte differentiation.

Association among placental 11ß-HSD2, PPAR-γ, and NF-κB p65 in small-for-gestational-age infants: A nested case-control study.

PROBLEM: 11ß-Hydroxysteroid dehydrogenase 2 (11ß-HSD2) catalyzes active glucocorticoids into their inactive products, preventing the passage of glucocorticoids into the fetus from maternal circulation. Peroxisome proliferator-activated receptor (PPAR)γ is a member of the nuclear receptor superfamily that regulates the expression of placental 11ß-HSD2. Nuclear factor-kappa B (NF-κB) is a transcription factor that regulates inflammatory signaling. This study aimed to investigate the association among 11ß-HSD2, PPAR-γ, and NF-κB p65 in small-for-gestational-age (SGA) infants. METHOD OF STUDY: Forty-six SGA and 46 appropriate-for-gestational-age (AGA) infants were enrolled in this study. Both newborns and placentas were weighed. Placental 11ß-HSD2 levels were measured using Western blotting. Placental PPAR-γ and NF-κB p65 were detected by immunohistochemistry. Placental inflammatory cytokines were evaluated by real-time RT-PCR. RESULTS: 11ß-HSD2 levels were lower in SGA placentas than those in AGA placentas. Placental PPAR-γ-positive nuclei were less in SGA than those in AGA. By contrast, placental NF-κB p65-positive nuclei were more in SGA than those in AGA. The levels of CRP, TNF-α, IL-8, and IL-1ß, several inflammatory cytokines, were higher in SGA placentas. Correlation analysis showed that neonatal weight was positively associated with PPAR-γ and 11ß-HSD2 in SGA placentas. By contrast, neonatal weight was inversely correlated with NF-κB p65 in SGA placentas. 11ß-HSD2 was positively correlated with PPAR-γ in SGA placentas. CONCLUSIONS: Inflammation-associated downregulation of placental PPAR-γ and 11ß-HSD2 may be involved in SGA.

Long-term 1-nitropyrene exposure induces endoplasmic reticulum stress and inhibits steroidogenesis in mice testes.

1-Nitropyrene (1-NP) is a representative nitro-polycyclic aromatic hydrocarbon from diesel exhaust. Recently, we found that maternal 1-NP exposure caused fetal growth retardation and disturbed cognitive development in adolescent female offspring. To investigate long-term 1-NP exposure on spermatogenesis and steroidogenesis, male mice were exposed to 1-NP (1.0 mg/kg/day) by gavage for 70 days. There was no significant difference on relative testicular weight, number of testicular apoptotic cells and epididymal sperm count between 1-NP-exposed mice and controls. Although long-term 1-NP exposure did not influence number of Leydig cells, steroidogenic genes and enzymes, including STAR, P450scc, P45017α and 17ß-HD, were downregulated in 1-NP-expoed mouse testes. Correspondingly, serum and testicular testosterone (T) levels were reduced in 1-NP-exposed mice. Additional experiment showed that testicular GRP78 mRNA and protein were upregulated by 1-NP. Testicular phospho-IRE1α and sliced xbp-1 mRNA, a downstream molecule of IRE1α, were elevated in 1-NP-exposed mice. Testicular phospho-PERK and phospho-eIF2α, a downstream molecule of PERK pathway, were increased in 1-NP-exposed mice. Testicular NOX4, a subunit of NAPDH oxidase, and HO-1, MDA, two oxidative stress markers, were increased in 1-NP-exposed mice. Testicular GSH and GSH/GSSG were decreased in 1-NP-exposed mice. These results suggest that long-term 1-NP exposure induces reactive oxygen species-evoked ER stress and disrupts steroidogenesis in mouse testes.

Maternal 1-nitropyrene exposure during pregnancy increases susceptibility of allergic asthma in adolescent offspring.

1-nitropyrene (1-NP) is widespread in the environment, as a typical nitrated polycyclic aromatic hydrocarbon. The purpose of this research was to explore the effects of gestational 1-NP exposure on susceptibility of allergic asthma in offspring. Maternal mice were exposed to 1-NP (100 µg kg-1) by gavage throughout the whole pregnancy. Pups were sensitized by injecting with ovalbumin (OVA) on postnatal day (PND)23, 29, and 36, respectively. At 7 days following the last injection, sensitized mice were exposed to aerosol OVA. As expected, there were quite a few inflammatory cells in the lungs of OVA-sensitized pups, accompanied by bronchial wall thickening and hyperemia. Elevated goblet cells and overproduced mucus were observed in the airways of OVA-sensitized pups. Interestingly, gestational 1-NP exposure aggravated infiltration of inflammatory cells, mainly eosinophils, in OVA-sensitized offspring. Although it had little effect on airway smooth muscle layer thickening and basement membrane fibrosis, gestational 1-NP exposure aggravated goblet cell hyperplasia, Muc5ac mRNA upregulation, and mucus secretion in the airways of OVA-sensitized and challenged offspring. Mechanistically, gestational 1-NP exposure aggravated elevation of pulmonary IL-5 in OVA-sensitized pups. These findings suggest that gestational 1-NP exposure increases susceptibility of allergic asthma in offspring.