Role of the GalNAc-galectin pathway in the healing of premature rupture of membranes.

BACKGROUND: Premature rupture of the membranes (PROM) is a key cause of preterm birth and represents a major cause of neonatal mortality and morbidity. Natural products N-acetyl-d-galactosamine (GalNAc), which are basic building blocks of important polysaccharides in biological cells or tissues, such as chitin, glycoproteins, and glycolipids, may improve possible effects of wound healing. METHODS: An in vitro inflammation and oxidative stress model was constructed using tumor necrosis-α (TNF-α) and lipopolysaccharide (LPS) action on WISH cells. Human amniotic epithelial cells (hAECs) were primarily cultured by digestion to construct a wound model. The effects of GalNAc on anti-inflammatory and anti-oxidative stress, migration and proliferation, epithelial-mesenchymal transition (EMT), glycosaminoglycan (GAG)/hyaluronic acid (HA) production, and protein kinase B (Akt) pathway in hAECs and WISH cells were analyzed using the DCFH-DA fluorescent probe, ELISA, CCK-8, scratch, transwell migration, and western blot to determine the mechanism by which GalNAc promotes amniotic wound healing. RESULTS: GalNAc decreased IL-6 expression in TNF-α-stimulated WISH cells and ROS expression in LPS-stimulated WISH cells (P < 0.05). GalNAc promoted the expression of Gal-1 and Gal-3 with anti-inflammatory and anti-oxidative stress effects. GalNAc promoted the migration of hAECs (50% vs. 80%) and WISH cells through the Akt signaling pathway, EMT reached the point of promoting fetal membrane healing, and GalNAc did not affect the activity of hAECs and WISH cells (P > 0.05). GalNAc upregulated the expression of sGAG in WISH cells (P < 0.05) but did not affect HA levels (P > 0.05). CONCLUSIONS: GalNAc might be a potential target for the prevention and treatment of PROM through the galectin pathway, including (i) inflammation; (ii) epithelial-mesenchymal transition; (iii) proliferation and migration; and (iv) regression, remodeling, and healing.

MitoQ protects against carbon tetrachloride-induced hepatocyte ferroptosis and acute liver injury by suppressing mtROS-mediated ACSL4 upregulation.

Ferroptosis has been shown to be involved in carbon tetrachloride (CCl4)-induced acute liver injury (ALI). The mitochondrion-targeted antioxidant MitoQ can eliminate the production of mitochondrial reactive oxygen species (mtROS). This study investigated the role of MitoQ in CCl4-induced hepatocytic ferroptosis and ALI. MDA and 4HNE were elevated in CCl4-induced mice. In vitro, CCl4 exposure elevated the levels of oxidized lipids in HepG2 cells. Alterations in the mitochondrial ultrastructure of hepatocytes were observed in the livers of CCl4-evoked mice. Ferrostatin-1 (Fer-1) attenuated CCl4-induced hepatic lipid peroxidation, mitochondrial ultrastructure alterations and ALI. Mechanistically, acyl-CoA synthetase long-chain family member 4 (ACSL4) was upregulated in CCl4-exposed human hepatocytes and mouse livers. The ACSL4 inhibitor rosiglitazone alleviated CCl4-induced hepatic lipid peroxidation and ALI. ACSL4 knockdown inhibited oxidized lipids in CCl4-exposed human hepatocytes. Moreover, CCl4 exposure decreased the mitochondrial membrane potential and OXPHOS subunit levels and increased the mtROS level in HepG2 cells. Correspondingly, MitoQ pretreatment inhibited the upregulation of ACSL4 in CCl4-evoked mouse livers and HepG2 cells. MitoQ attenuated lipid peroxidation in vivo and in vitro after CCl4 exposure. Finally, MitoQ pretreatment alleviated CCl4-induced hepatocytic ferroptosis and ALI. These findings suggest that MitoQ protects against hepatocyte ferroptosis in CCl4-induced ALI via the mtROS-ACSL4 pathway.

PFASs in Cerebrospinal Fluids and Blood-CSF Barrier Permeability in Patients with Cognitive Impairment.

Attention has been drawn to the associations between PFASs and human cognitive decline. However, knowledge on the occurrence and permeability of PFASs in the brains of patients with cognitive impairment has not been reported. Here, we determined 30 PFASs in paired sera and cerebrospinal fluids (CSFs) from patients with cognitive impairment (n = 41) and controls without cognitive decline (n = 18). We revealed similar serum PFAS levels but different CSF PFAS levels, with lower CSF PFOA (median: 0.125 vs 0.303 ng/mL, p < 0.05), yet higher CSF PFOS (0.100 vs 0.052 ng/mL, p < 0.05) in patients than in controls. Blood-brain transfer rates also showed lower RCSF/Serum values for PFOA and higher RCSF/Serum values for PFOS in patients, implying potential heterogeneous associations with cognitive function. The RCSF/Serum values for C4-C14 perfluoroalkyl carboxylates exhibited a U-shape trend with increasing chain length. Logistic regression analyses demonstrated that CSF PFOS levels were linked to the heightened risk of cognitive impairment [odds ratio: 3.22 (1.18-11.8)] but not for serum PFOS. Toxicity inference results based on the Comparative Toxicogenomics Database suggested that PFOS in CSF may have a greater potential to impair human cognition than other PFASs. Our results contribute to a better understanding of brain PFAS exposure and its potential impact on cognitive function.

Pubertal exposure to Microcystin-LR arrests spermatogonia proliferation by inducing DSB and inhibiting SIRT6 dependent DNA repair in vivo and in vitro.

The reproduction toxicity of pubertal exposure to Microcystin-LR (MC-LR) and the underlying mechanism needs to be further investigated. In the current study, pubertal male ICR mice were intraperitoneally injected with 2 µg/kg MC-LR for four weeks. Pubertal exposure to MC-LR decreased epididymal sperm concentration and blocked spermatogonia proliferation. In-vitro studies found MC-LR inhibited cell proliferation of GC-1 cells and arrested cell cycle in G2/M phase. Mechanistically, MC-LR exposure evoked excessive reactive oxygen species (ROS) and induced DNA double-strand break in GC-1 cells. Besides, MC-LR inhibited DNA repair by reducing PolyADP-ribosylation (PARylation) activity of PARP1. Further study found MC-LR caused proteasomal degradation of SIRT6, a monoADP-ribosylation enzyme which is essential for PARP1 PARylation activity, due to destruction of SIRT6-USP10 interaction. Additionally, MG132 pretreatment alleviated MC-LR-induced SIRT6 degradation and promoted DNA repair, leading to the restoration of cell proliferation inhibition. Correspondingly, N-Acetylcysteine (NAC) pre-treatment mitigated the disturbed SIRT6-USP10 interaction and SIRT6 degradation, causing recovered DNA repair and subsequently restoration of cell proliferation inhibition in MC-LR treated GC-1 cells. Together, pubertal exposure to MC-LR induced spermatogonia cell cycle arrest and sperm count reduction by oxidative DNA damage and simultaneous SIRT6-mediated DNA repair failing. This study reports the effect of pubertal exposure to MC-LR on spermatogenesis and complex mechanism how MC-LR induces spermatogonia cell proliferation inhibition.

Mitoquinone protects against acetaminophen-induced liver injury in an FSP1-dependent and GPX4-independent manner.

Mitochondrial oxidative stress has been a crucial mediator in acetaminophen (APAP)-induced hepatotoxicity. MitoQ, an analog of coenzyme Q10, is targeted towards mitochondria and acts as a potent antioxidant. This study aimed to explore the effect of MitoQ on APAP-induced liver injury and its possible mechanisms. To investigate this, CD-1 mice and AML-12 cells were treated with APAP. Hepatic MDA and 4-HNE, two markers of lipid peroxidation (LPO), were elevated as early as 2 h after APAP. Oxidized lipids were rapidly upregulated in APAP-exposed AML-12 cells. Hepatocyte death and mitochondrial ultrastructure alterations were observed in APAP-induced acute liver injury. The in vitro experiments showed that mitochondrial membrane potentials and OXPHOS subunits were downregulated in APAP-exposed hepatocytes. MtROS and oxidized lipids were elevated in APAP-exposed hepatocytes. We discovered that APAP-induced hepatocyte death and liver injury were ameliorated by attenuation of protein nitration and LPO in MitoQ-pretreated mice. Mechanistically, knockdown of GPX4, a key enzyme for LPO defense systems, exacerbated APAP-induced oxidized lipids, but did not influence the protective effect of MitoQ on APAP-induced LPO and hepatocyte death. Whereas knockdown of FSP1, another key enzyme for LPO defense systems, had little effect on APAP-induced lipid oxidation but partially weakened the protection of MitoQ on APAP-induced LPO and hepatocyte death. These results suggest that MitoQ may alleviate APAP-evoked hepatotoxicity by eliminating protein nitration and suppressing hepatic LPO. MitoQ prevents APAP-induced liver injury partially dependent of FSP1 and independent of GPX4.

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.

Polycyclic aromatic hydrocarbon exposure burden: Individual and mixture analyses of associations with chronic obstructive pulmonary disease risk.

Accumulating data demonstrate that polycyclic aromatic hydrocarbons (PAH) exposure is linked to compromised respiratory diseases. This study aimed to analyze urinary PAH metabolites and their associations with chronic obstructive pulmonary disease (COPD) in a sample size of 3015 subjects from a total population of 50,588 from the National Health and Nutrition Examination Survey (NHANES) in 2007-2016. Results showed that the most predominant metabolite was 1-Hydroxynaphthalene (1-NAP, 84%) with a geometric mean concentration of 50,265 ng/L, followed by its homologue 2-NAP (10%), both of which arose from sources including road emission, smoking and cooking. Multiple logistic regression showed that seven of the ten major PAH metabolites were correlated with increased COPD risk: including 1-NAP (OR: 1.83, 95%CI: 1.25, 2.69), 2-Hydroxyfluorene (2-FLU, OR: 2.29, 95%CI: 1.42, 3.68) and 1-Hydroxyphenanthrene (1-PHE, OR: 2.79, 95%CI: 1.85, 4.21), when compared to the lowest tertile after adjusted for covariates. Total exposure burden per PAH congener sub-group demonstrated persistent positive correlation with COPD for ∑PHE (OR: 1.80, 95%CI: 1.34, 2.43) and ∑FLU (OR: 2.74, 95%CI: 1.77, 4.23) after adjusted for covariates. To address the contribution of PAH exposure as mixture towards COPD, weighted quantile sum (WQS) regression analyses revealed that 1-NAP, 9-Hydroxyfluorene (9-FLU), 3-Hydroxyfluorene (3-FLU) and 1-PHE were among the top contributors in the associations with COPD. Our results demonstrate the contemporary yet ongoing exposure burden of PAH exposure for over a decade, particularly towards NAPs and FLUs that contribute significantly to COPD risk, calling for more timely environmental regulation.

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.

1-Nitropyrene disrupts testicular steroidogenesis via oxidative stress-evoked PERK-eIF2α pathway.

Our previous study showed 1-Nitropyrene (1-NP) exposure disrupted testicular testosterone synthesis in mouse, but the exact mechanism needs further investigation. The present research found 4-phenylbutyric acid (4-PBA), an endoplasmic reticulum (ER) stress inhibitor, recovered 1-NP-induced ER stress and testosterone synthases reduction in TM3 cells. GSK2606414, a protein kinase-like ER kinase (PERK) kinase inhibitor, attenuated 1-NP-induced PERK-eukaryotic translation initiation factor 2α (eIF2α) signaling activation and downregulation of steroidogenic proteins in TM3 cells. Both 4-PBA and GSK2606414 attenuated 1-NP-induced steroidogenesis disruption in TM3 cells. Further studies used N-Acetyl-L-cysteine (NAC) as a classical antioxidant to explore whether oxidative stress-activated ER stress mediated 1-NP-induced testosterone synthases reduction and steroidogenesis disruption in TM3 cells and mouse testes. The results showed NAC pretreatment mitigated oxidative stress, and subsequently attenuated ER stress, particularly PERK-eIF2α signaling activation, and downregulation of testosterone synthases in 1-NP-treated TM3 cells. More importantly, NAC extenuated 1-NP-induced testosterone synthesis in vitro and in vivo. The current work indicated that oxidative stress-caused ER stress, particularly PERK-eIF2α pathway activation, mediates 1-NP-downregulated steroidogenic proteins and steroidogenesis disruption in TM3 cells and mouse testes. Significantly, the current study provides a theoretical basis and demonstrates the experimental evidence for the potential application of antioxidant, such as NAC, in public health prevention, particularly in 1-NP-induced endocrine disorder.

Association between cadmium exposure and pulmonary function reduction: Potential mediating role of telomere attrition in chronic obstructive pulmonary disease patients.

BACKGROUND: Environmental cadmium (Cd) exposure is linked to pulmonary function injury in the general population. But, the association between blood Cd concentration and pulmonary function has not been investigated thoroughly in chronic obstructive pulmonary disease (COPD) patients, and the potential mechanisms are unclear. METHODS: All eligible 789 COPD patients were enrolled from Anhui COPD cohort. Blood specimens and clinical information were collected. Pulmonary function test was conducted. The subunit of telomerase, telomerase reverse transcriptase (TERT), was determined through enzyme linked immunosorbent assay (ELISA). Blood Cd was measured via inductively coupled-mass spectrometer (ICP-MS). RESULTS: Blood Cd was negatively and dose-dependently associated with pulmonary function. Each 1-unit increase of blood Cd was associated with 0.861 L decline in FVC, 0.648 L decline in FEV1, 5.938 % decline in FEV1/FVC %, and 22.098 % decline in FEV1 % among COPD patients, respectively. Age, current-smoking, self-cooking and higher smoking amount aggravated Cd-evoked pulmonary function decrease. Additionally, there was an inversely dose-response association between Cd concentration and TERT in COPD patients. Elevated TERT obviously mediated 29.53 %, 37.50 % and 19.48 % of Cd-evoked FVC, FEV1, and FEV1 % declines in COPD patients, respectively. CONCLUSION: Blood Cd concentration is strongly associated with the decline of pulmonary function and telomerase activity among COPD patients. Telomere attrition partially mediates Cd-induced pulmonary function decline, suggesting an underlying mechanistic role of telomere attrition in pulmonary function decline from Cd exposure in COPD patients.

Early-life cadmium exposure elevates susceptibility to allergic asthma in ovalbumin-sensitized and challenged mice.

Increasing evidence have demonstrated that early-life exposure to environmental toxicants elevates risk of allergic asthma. Cadmium (Cd) is widely present in the environment. The purposes of this study were to evaluate the impact of early-life Cd exposure on susceptibility to ovalbumin (OVA)-evoked allergic asthma. Newly weaned mice were subjected to a low concentration of CdCl2 (1 mg/L) by drinking water for 5 consecutive weeks. Penh value, an index of airway obstruction, was increased in OVA-stimulated and challenged pups. Abundant inflammatory cells were observed in the lung of OVA-exposed pups. Goblet cell hyperplasia and mucus secretion were shown in the airway of OVA-stimulated and challenged pups. Early-life Cd exposure exacerbated OVA-evoked airway hyperreactivity, Goblet cell hyperplasia and mucus secretion. The in vitro experiments showed that mucoprotein gene MUC5AC mRNA was upregulated in Cd-exposed bronchial epithelial cells. Mechanistically, endoplasmic reticulum (ER) stress-related molecules GRP78, p-eIF2α, CHOP, p-IRE1α and spliced XBP-1 (sXBP-1) were elevated in Cd-subjected bronchial epithelial cells. The blockade of ER stress, using chemical inhibitor 4-PBA or sXBP-1 siRNA interference, attenuated Cd-induced MUC5AC upregulation in bronchial epithelial cells. These results indicate that early-life Cd exposure aggravates OVA-induced allergic asthma partially through inducing ER stress in bronchial epithelial cells.

Serum IL-27 predicts the severity and prognosis in patients with community-acquired pneumonia: a prospective cohort study.

Background: The previous studies have revealed that IL-27 was involved in the pathophysiology of pulmonary inflammatory diseases. However, the role of IL-27 in community-acquired pneumonia (CAP) was unclear. The goal of this research was to explore the associations of serum IL-27 with the severity and prognosis among CAP patients through a prospective cohort study. Methods: The whole of 239 healthy population and 239 CAP patients were enrolled. Fasting blood samples were collected. Inflammatory cytokines were detected using enzyme linked immunosorbent assay (ELISA). Demographic characteristics and clinical information were analyzed. Results: Serum IL-27 on admission was significantly risen in CAP patients compared with control subjects. Besides, serum IL-27 was gradually increased in line with CAP severity scores. Correlative analysis suggested that serum IL-27 was associated with blood routine indices, renal function, liver function, myocardial function and inflammatory cytokines. Linear and logistic regression analyses revealed that serum IL-27 was positively correlated with CAP severity scores. Logistic regression analysis demonstrated that serum higher IL-27 on admission elevated the risks of vasoactive agent usage and longer hospital stay during hospitalization among CAP patients. Conclusions: Serum IL-27 is markedly and positively associated with the severity and poor prognosis among CAP patients, indicating that IL-27 may involve in the pathophysiological process of CAP. Serum IL-27 may be used as a biomarker for diagnosis and prognosis in CAP patients.

Arsenic induces ferroptosis and acute lung injury through mtROS-mediated mitochondria-associated endoplasmic reticulum membrane dysfunction.

The goal of this study was to analyze whether mitochondria-associated endoplasmic reticulum membrane (MAMs) dysfunction mediated arsenic (As)-evoked pulmonary ferroptosis and acute lung injury (ALI). As exposure led to alveolar structure damage, inflammatory cell infiltration and pulmonary function decline in mice. Ferritin, the marker of iron overload, was increased, GPX4, the index of lipid peroxidation, was decreased in As-exposed lungs and pulmonary epithelial cells (MLE-12). Pretreatment with ferrostatin-1 (Fer-1), the inhibitor of ferroptosis, alleviated As-evoked ALI. In addition, As-induced non-heme iron deposition was inhibited in Fer-1 pretreated-mice. Moreover, As-triggered mitochondria damage and ferroptosis were mitigated in Fer-1 pretreated-MLE-12 cells. Mechanistically, PERK phosphorylation and mitofusin-2 (Mfn-2) reduction was observed in As-exposed MLE-12 cells and mice lungs. Additionally, the interaction between PERK and Mfn-2 was downregulated and MAMs dysfunction was observed in As-exposed MLE-12 cells. Intriguingly, PERK inhibitor and Mfn-2-overexpression all mitigated As-induced ferroptosis in MLE-12 cells. Additionally, CLPP and mtHSP70, the markers of mitochondrial stress, were upregulated, mitochondrial ROS (mtROS) was elevated, mitochondrial membrane potential (MMP) and ATP were decreased in As-exposed MLE-12 cells. Mitoquinone mesylate (MitoQ), a novel mitochondrial-targeted antioxidant, alleviated As-induced excess mtROS, mitochondrial stress, MAMs dysfunction in pulmonary epithelial cells. Similarly, in vivo experiments indicated that MitoQ pretreatment countered As-induced pulmonary ferroptosis and ALI. These data indicated that mtROS-initiated MAMs dysfunction is, at least partially, implicated in As-evoked ferroptosis and ALI.

miR-6769b-5p targets CCND-1 to regulate proliferation in cadmium-treated placental trophoblasts: Association with the impairment of fetal growth.

Environmental cadmium (Cd) is positively associated with placental impairment and fetal growth retardation. Nevertheless, its potential mechanisms remain unclear. microRNAs (miRNAs) are known to influence placental development and fetal growth. This work was aimed to determine which miRNAs are involved in Cd-impaired placental and fetal development based on the mRNA and miRNA expression profiles analysis. As a result, gestational Cd exposure deceased fetal and placental weight, and reduced the protein level of PCNA in human and mouse placentae. Furthermore, the results of mRNA microarray showed that Cd-downregulated mRNAs were predictively correlated with several biological processes, including cell proliferation, differentiation and motility. In addition, the results of miRNA microarray and qPCR assay demonstrated that Cd significantly increased the level of miR-6769b-5p, miR-146b-5p and miR-452-5p. Integrated analysis of Cd-upregulated miRNAs predicted target genes and Cd-downregulated mRNAs found that overlapping mRNAs, such as CCND1, CDK13, RINT1 and CDC26 were also significantly associated with cell proliferation. Further experiments showed that miR-6769b-5p inhibitor, but not miR-146b-5p and miR-452-5p, markedly reversed Cd-downregulated the expression of proliferation-related mRNAs, and thereby restored Cd-decreased the proteins level of CCND1 and PCNA in human placental trophoblasts. Dual luciferase reporter assay further revealed that miR-6769b-5p directly targets CCND1. Finally, the case-control study demonstrated that increased miR-6769b-5p level and impaired cell proliferation were observed in small-for-gestational-age human placentae. In conclusion, miR-6769b-5p targets CCND-1 to regulate proliferation in Cd-treated placental trophoblasts, which is associated with the impairment of fetal growth. Our findings imply that placental miR-6769b-5p may be used as an epigenetic marker for environmental pollutants-caused fetal growth restriction and its late-onset chronic diseases.

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.

Lipopolysaccharide Downregulates 11ß-Hydroxysteroid Dehydrogenase 2 Expression through Inhibiting Peroxisome Proliferator-Activated Receptor-γ in Placental Trophoblasts.

It is increasingly recognized that excessive glucocorticoids induce fetal intrauterine growth restriction (IUGR). Placental 11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2), a glucocorticoid-catalyzing enzyme, prevents active glucocorticoids from maternal circulation into the fetus, thus protecting against IUGR. Previous studies demonstrated gestational LPS exposure caused fetal IUGR. The aim of the current study was to investigate the effects of LPS on 11ß-HSD2 in mice placentas and human placental trophoblasts. Pregnant ICR(CD-1) mice were i.p. injected with LPS (200 µg/kg) on gestational day 16. As expected, gestational LPS exposure downregulated 11ß-HSD2 in mice placentas. In vitro, LPS downregulated 11ß-HSD2 in human placental trophoblasts. Additional experiment showed that LPS, which activated NF-κB, suppressed rosiglitazone-induced activation of peroxisome proliferator-activated receptor-γ (PPARγ) in mice placentas and human placental trophoblasts. Moreover, NF-κB p65 knockdown and specific NF-κB inhibitor attenuated LPS-induced suppression of PPARγ nuclear translocation in human placental trophoblasts. In addition, NF-κB p65 knockdown attenuated LPS-induced downregulation of 11ß-HSD2 in human placental trophoblasts. Mechanically, LPS promoted physical interaction between NF-κB p65 and PPARγ in the cytoplasm and nucleus of placental trophoblasts. Finally, pretreatment with rosiglitazone, a PPARγ agonist, partially alleviated LPS-induced reduction of fetal weight and crown-rump length. Taken together, these results suggest that LPS downregulates 11ß-HSD2 through suppressing PPARγ in placental trophoblasts. Placental 11ß-HSD2 downregulation may contribute partially to LPS-induced fetal IUGR.

Correlations among Pulmonary DJ-1, VDR and Nrf-2 in patients with Chronic Obstructive Pulmonary Disease: A Case-control Study.

Parkinson protein 7 (PARK7)/DJ-1 (DJ-1) is a redox sensitive molecular and stabilizer of nuclear factor erythroid 2-related factor 2 (Nrf-2). Nrf-2 regulates the downstream antioxidant defense system and exerts a significant function in patients with chronic obstructive pulmonary disease (COPD). Vitamin D receptor (VDR) is the nuclear receptor that regulates the downstream target genes. This study aimed to analyze the associations among pulmonary function, DJ-1, VDR and Nrf-2 in COPD patients. Serum was collected from 180 COPD patients and control subjects. Thirty-five lung tissues were obtained. DJ-1 was measured using ELISA and western blotting. Nrf-2 and VDR were detected by immunohistochemistry. Serum and pulmonary DJ-1 levels were lower in COPD patients than those in control subjects. Pulmonary VDR-positive nuclei were reduced in COPD patients. Nrf-2-positive nuclei were reduced in lung tissues of COPD patients. On the contrary, Nrf-2-related downstream target proteins were elevated in COPD patients. Further correlation analysis indicated that forced expiratory volume in 1 second (FEV1) was positively associated with pulmonary DJ-1, VDR and Nrf-2 in patients with COPD. In addition, there were positive correlations among DJ-1, VDR and Nrf-2 in lung tissues of COPD patients. In conclusion, DJ-1, VDR and Nrf-2 were decreased in COPD patients compared with control subjects. The reduction of DJ-1 and VDR associating with Nrf-2 downregulation may be involved in the process of COPD.

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.

Paternal fenvalerate exposure transgenerationally impairs cognition and hippocampus in female offspring.

The impairments of maternal fenvalerate exposure have been well documented in previous study, but little was known about the effects of paternal fenvalerate exposure. The current study aimed to assess the effects of paternal fenvalerate exposure on spatial cognition and hippocampus across generations. Adult male mice (F0) were orally administered with fenvalerate (0, 2 or 20 mg/kg) for 5 weeks. F0 males were mated with untreated-females to generate F1 generation. F1 males were mated with F1 control females to generate F2 generation. For F1 and F2 adult offspring, spatial learning and memory were detected by Morris water maze. Results showed that spatial learning and memory were impaired in F1 females but not F1 males derived from F0 males exposed to 20 mg/kg FEN. Furthermore, significant impairment of spatial learning and memory were found in F2 females but not F2 males derived from F0 males exposed to 20 mg/kg FEN. As expected, histopathology showed that neural density in hippocampal CA3 region was reduced in F1 and F2 females but not F1 and F2 males derived from F0 males exposed to 20 mg/kg FEN. Mechanistically, hippocampal thyroid hormone receptor alpha1 (TRα1) was down-regulated in F1 and F2 females derived from F0 males exposed to 20 mg/kg FEN. Correspondingly, hippocampal brain-derived neurotrophic factor, tropomyosin receptor kinase B and p75 neurotrophin receptor, three downstream genes of TR signaling, were down-regulated in F1 and F2 females. Taken together, the present study firstly found that paternal fenvalerate exposure transgenerationally impaired spatial cognition in a gender-dependent manner. Hippocampal TR signaling may, at least partially, contribute to the process of cognitive impairment induced by paternal fenvalerate exposure. Further exploration in the mode of action of fenvalerate is critically important to promote human health and environmental safety.

Gestational arsenic exposure induces anxiety-like behaviors in adult offspring by reducing DNA hydroxymethylation in the developing brain.

Several studies found that reduction of 5-hydroxymethylcytosine (5hmC), a marker of DNA hydroxymethylation highly enriched in developing brain, is associated with anxiety-like behaviors. This study aimed to investigate whether gestational arsenic (As) exposure induces anxiety-like behaviors in adult offspring by reducing DNA hydroxymethylation in the developing brain. The dams drank ultrapure water containing NaAsO2 (15 mg/L) throughout pregnancy. Anxiety-like behaviors were evaluated and developing brain 5hmC was detected. Results showed that anxiety-like behaviors were observed in As-exposed adult offspring. In addition, 5hmC content was reduced in As-exposed fetal brain. Despite no difference on Tet1, Tet2 and Tet3 expression, TET activity was suppressed in As-exposed fetal brain. Mechanistically, alpha-ketoglutarate (α-KG), a cofactor for TET dioxygenases, was reduced and Idh2, a key enzymatic gene for mitochondrial α-KG synthesis, was downregulated in As-exposed fetal brain. Of interest, ascorbic acid, a cofactor for TET dioxygenases, reversed As-induced suppression of TET activity. Moreover, ascorbic acid attenuated As-induced reduction of 5hmC in fetal brain. In addition, ascorbic acid alleviated As-induced anxiety-like behaviors in adult offspring. Taken together, these results suggest that gestational As exposure induces anxiety-like behaviors in adult offspring, possibly at part, by inhibiting DNA hydroxymethylation in developing brain.