Modeling the human placenta: in vitro applications in developmental and reproductive toxicology

During its temporary tenure, the placenta has extensive and specialized functions that are critical for pre- and post-natal development. The consequences of chemical exposure in utero can have profound effects on the structure and function of pregnancy-associated tissues and the life-long health of the birthing person and their offspring. However, the toxicological importance and critical functions of the placenta to embryonic and fetal development and maturation have been understudied. This narrative will review early placental development in humans and highlight some in vitro models currently in use that are or can be applied to better understand placental processes underlying developmental toxicity due to in utero environmental exposures.

Benzo[a]pyrene evokes epithelial-mesenchymal transition and pulmonary fibrosis through AhR-mediated Nrf2-p62 signaling

Benzo[a]pyrene (BaP) and its metabolic end product benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide (BPDE), are known toxic environmental pollutants. This study aimed to analyze whether sub-chronic BPDE exposure initiated pulmonary fibrosis and the potential mechanisms. In this work, male C57BL6/J mice were exposed to BPDE by dynamic inhalation exposure for 8 weeks. Our results indicated that sub-chronic BPDE exposure evoked pulmonary fibrosis and epithelial-mesenchymal transition (EMT) in mice. Both in vivo and in vitro, BPDE exposure promoted nuclear translocation of Snail. Further experiments indicated that nuclear factor erythroid 2-related factor 2 (Nrf2) and p62 were upregulated in BPDE-exposed alveolar epithelial cells. Moreover, Nrf2 siRNA transfection evidently attenuated BPDE-induced p62 upregulation. Besides, p62 shRNA inhibited BPDE-incurred Snail nuclear translocation and EMT. Mechanically, BPDE facilitated physical interaction between p62 and Snail in the nucleus, then repressed Snail protein degradation by p62-dependent autophagy-lysosome pathway, and finally upregulated transcriptional activity of Snail. Additionally, aryl hydrocarbon receptor (AhR) was activated in BPDE-treated alveolar epithelial cells. Dual-luciferase assay indicated activating AhR could bind to Nrf2 gene promoter. Moreover, pretreatment with CH223191 or α-naphthoflavone (α-NF), AhR antagonists, inhibited BPDE-activated Nrf2-p62 signaling, and alleviated BPDE-induced EMT and pulmonary fibrosis in mice. Taken together, AhR-mediated Nrf2-p62 signaling contributes to BaP-induced EMT and pulmonary fibrosis.

Histological Features of Uterine Myometrial Dysfunction: Possible Involvement of Localized Inflammation

OBJECTIVE

The latest perspective suggests that elevated levels of inflammation and cytokines are implicated in atonic postpartum hemorrhage. Lipopolysaccharide (LPS) has been widely used to induce inflammation in animal models. Therefore, this study aimed to induce uterine inflammation using LPS to investigate whether local inflammation triggers dysfunction and atrophy in the myometrium, as well as the potential underlying molecular mechanisms involved.

METHODS

In vivo, an animal model was established by intraperitoneal injection of 300 μg/ kg LPS in rats on gestational day 21. Hematoxylin-eosin (H&E) staining and Masson staining were employed to determine morphological changes in the rat uterine smooth muscle. Enzyme-linked immunosorbent assay (ELISA) was used to detect inflammatory cytokines. Immunohistochemistry, tissue fluorescence, and Western blotting were conducted to assess the expression levels of the uterine contraction-related proteins Toll-like receptor 4 (TLR4) and the nuclear factor kappa-B (NF-κB) signaling pathway. In vitro, human uterine smooth muscle cells (HUtSMCs) were exposed to 2 μg/mL LPS to further elucidate the involvement of the TLR4/NF-κB signaling pathway in LPS-mediated inflammation.

RESULTS

In this study, LPS induced uterine myometrial dysfunction in rats, leading to a disorganized arrangement, a significant increase in collagen fiber deposition, and widespread infiltration of inflammatory cells. In both in vivo animal models and in vitro HUtSMCs, LPS elevated IL-6, IL-1β, and TNF-α levels while concurrently suppressing the expression of connexin 43 (Cx43) and oxytocin receptor (OXTR). Mechanistically, the LPS-treated group exhibited TLR4 activation, and the phosphorylation levels of p65 and IκBα were notably increased.

CONCLUSION

LPS triggered the TLR4/NF-κB signaling pathway, inducing an inflammatory response in the myometrium and leading to uterine myometrial dysfunction and uterine atony.

Associations of the Serum KL-6 with Severity and Prognosis in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND

As a biomarker of alveolar-capillary basement membrane injury, Krebs von den Lungen-6 (KL-6) is involved in the occurrence and development of pulmonary diseases. However, the role of the KL-6 in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has yet to be elucidated. This prospective study was designed to clarify the associations of the serum KL-6 with the severity and prognosis in patients with AECOPD.

METHODS

This study enrolled 199 eligible AECOPD patients. Demographic data and clinical characteristics were recorded. Follow-up was tracked to evaluate acute exacerbation and death. The serum KL-6 concentration was measured via an enzyme-linked immunosorbent assay.

RESULTS

Serum KL-6 level at admission was higher in AECOPD patients than in control subjects. The serum KL-6 concentration gradually elevated with increasing severity of AECOPD. Pearson and Spearman analyses revealed that the serum KL-6 concentration was positively correlated with the severity score, monocyte count and concentrations of C-reactive protein, interleukin-6, uric acid, and lactate dehydrogenase in AECOPD patients during hospitalization. A statistical analysis of long-term follow-up data showed that elevated KL-6 level at admission was associated with longer hospital stays, an increased risk of future frequent acute exacerbations, and increased severity of exacerbation in COPD patients.

CONCLUSION

Serum KL-6 level at admission is positively correlated with increased disease severity, prolonged hospital stay and increased risk of future acute exacerbations in COPD patients. There are positive dose-response associations of elevated serum KL-6 with severity and poor prognosis in COPD patients. The serum KL-6 concentration could be a novel diagnostic and prognostic biomarker in AECOPD patients.

ALKBH5 SUMOylation-mediated FBXW7 m6A modification regulates alveolar cells senescence during 1-nitropyrene-induced pulmonary fibrosis

Our previous study revealed that 1-nitropyrene (1-NP) exposure evoked pulmonary fibrosis in mice. However, the exact mechanism remained elusive. We found that 1-NP induced telomere damage and cellular senescence in mice lungs, and two alveolar epithelial cells lines. 1-NP downregulated telomere repeat binding factor 2 (TRF2), and upregulated FBXW7. Mechanistically, 1-NP-caused TRF2 ubiquitination and proteasomal degradation depended on E3 ubiquitin ligase activity of FBXW7. Moreover, 1-NP upregulated FBXW7 m6A modification via an ALKBH5-YTHDF1-dependent manner. Further analysis suggested 1-NP promoted ALKBH5 SUMOylation and subsequent proteasomal degradation. Additionally, 1-NP evoked mitochondrial reactive oxygen species (mtROS) overproduction. Mito-TEMPO, a mitochondrial-targeted antioxidant, mitigated 1-NP-caused mtROS overproduction, ALKBH5 SUMOylation, FBXW7 m6A modification, TRF2 degradation, cellular senescence, and pulmonary fibrosis. Taken together, mtROS-initiated ALKBH5 SUMOylation and subsequent FBXW7 m6A modification is indispensable for TRF2 degradation and cellular senescence in alveolar epithelial cells during 1-NP-induced pulmonary fibrosis. Our study provides target intervention measures towards 1-NP-evoked pulmonary fibrosis.

Docosahexaenoic acid protects against lipopolysaccharide-induced fetal growth restriction via inducing the ubiquitination and degradation of NF-κB p65 in placental trophoblasts

Lipopolysaccharide (LPS) could induce adverse birth outcomes by evoking inflammation. We investigated the effect and mechanism of docosahexaenoic acid (DHA) on LPS-induced placental inflammation and fetal growth restriction (FGR). In vivo, pregnant CD-1 mice were divided into four groups: Ctrl, DHA, LPS and DHA+LPS group. We found that DHA pretreatment reduced the incidence of FGR induced by LPS and activated the expression of peroxisome proliferators-activated receptor gamma (PPARγ) in placental tissue. Moreover, the LPS-induced increase of mRNA levels of Tnf-α, Il-6, Il-1β, Mip-2 and Kc in placental tissue was significantly attenuated by DHA pretreatment. A similar effect of DHA was observed in serum of pregnant mice and amniotic fluid. In contrast, the levels of the IL-10 were significantly increased after DHA pretreatment. In vitro, we clarified that DHA antagonized the activation of the NF-κB signaling pathway induced by LPS, which was dependent on PPARγ. Subsequently, CHX (translation inhibitor) was used to indicated that PPARγ significantly increased the degradation rate of p65, an effect that was inhibited by MG132 (proteasome inhibitor) treatment. Finally, it was confirmed that the activation of PPARγ could significantly promote the ubiquitination and degradation of p65. Our results suggested that DHA alleviated LPS-induced inflammatory responses and FGR by activating PPARγ expression, leading to p65 ubiquitination and degradation.

Low 15d-PGJ2 status is associated with oxidative stress in chronic obstructive pulmonary disease patients

BACKGROUND

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent nuclear receptor and highly expressed in human and rodent lungs. 15-Deoxy-delta-^12,14-prostaglandin J2 (15d-PGJ2), known for cyclopentenone prostaglandin, is the endogenous ligand of PPARγ. However, the associations among PPARγ, 15d-PGJ2 and chronic obstructive pulmonary disease (COPD) were unclear.

METHODS

All 130 fasting blood samples and 40 lung specimens were obtained from COPD patients and control subjects. Serum 15d-PGJ2 was detected by ELISA. The expressions of oxidative stress indicators were measured using western blotting and PPARγ nuclei were evaluated with immunohistochemistry in lungs. The associations among serum 15d-PGJ2, pulmonary PPARγ and oxidative stress indicators, and COPD were estimated.

RESULTS

Serum 15d-PGJ2 was reduced in COPD patients compared with healthy volunteers. Linear and logistic regression analysis indicated that serum 15d-PGJ2 was positively associated with pulmonary function in COPD patients. In addition, PPARγ-positive nuclei were reduced and oxidative stress indicators, included HO-1 and NOX-4, were increased in lungs of COPD patients. Further correlative analysis suggested that pulmonary function parameters was positively correlated with serum 15d-PGJ2 and pulmonary PPARγ-positive nuclei, inversely related to oxidative stress indicators in lungs of COPD patients. Pretreatment with 15d-PGJ2 obviously attenuated TNFα-induced oxidative stress in BEAS-2B cells.

CONCLUSIONS

Serum 15d-PGJ2 and pulmonary PPARγ are reduced, and oxidative stress is elevated in COPD patients. Serum 15d-PGJ2 is inversely associated with oxidative stress in COPD patients.

The association between serum complement C3a and severity in patients with community-acquired pneumonia

Background

A few studies found that the complement system may be involved in the onset and progression of community-acquired pneumonia (CAP). However, the role of the complement system in CAP was obscure. The goal of this study was to analyze the association of serum complement C3a with CAP severity scores based on a cross-sectional study.

Methods

All 190 CAP patients and 95 control subjects were enrolled. Demographic information and clinical data were extracted. Peripheral blood samples were collected on admission.

Results

Serum complement C3a on admission was elevated in CAP patients compared with healthy subjects. The level of complement C3a was gradually elevated in parallel with CAP severity scores (CURB-65, CRB-65, PSI, SMART-COP, and CURXO). Complement C3a was positively correlated with blood routine parameters, renal function markers, and inflammatory cytokines in CAP patients. Furthermore, multivariate linear and logistic regression models found that serum complement C3a on admission was positively associated with CAP severity scores. Mechanistic research suggested that complement system inhibition alleviated Streptococcus pneumoniae-induced upregulation of IL-1β, TNF-α, IL-6, and CRP in MLE-12 cells.

Conclusions

Serum complement C3a on admission is positively associated with the severity of CAP patients. Inhibiting complement system attenuates S. pneumoniae-elevated secretion of inflammatory cytokines in pulmonary epithelial cells, indicating that complement C3a is involved in the pathophysiology of CAP. Serum complement C3a may serve as an earlier diagnostic biomarker for CAP.

Serum 25-hydroxycholesterol levels are increased in patients with coronavirus disease 2019

BACKGROUND

25-hydroxycholesterol (25HC), produced by cholesterol 25-hydroxylase (CH25H) in macrophages, has been reported to inhibit the replication of viral pathogens such as severe acute respiratory syndrome coronavirus-2. Also, CH25H expression in macrophages is robustly induced by interferons (IFNs).

OBJECTIVE

To better understand the serum level increase of 25HC in coronavirus disease 2019 (COVID-19) and how it relates to the clinical picture.

METHODS

We measured the serum levels of 25HC and five other oxysterols in 17 hospitalized COVID-19 patients.

RESULTS

On admission, 25HC and 27-hydroxycholesterol (27HC) serum levels were elevated; however, 7-ketocholesterol (7KC) levels were lower in patients with COVID-19 than in the healthy controls. There was no significant correlation between 25HC serum levels and disease severity markers, such as interferon-gamma (IFN-γ) and interleukin 6. Dexamethasone effectively suppressed cholesterol 25-hydroxylase (CH25H) mRNA expression in RAW 264.7 cells, a murine leukemia macrophage cell line, with or without lipopolysaccharide or IFNs; therefore, it might mitigate the increasing effects of COVID-19 on the serum levels of 25HC.

CONCLUSIONS

Our results highlighted that 25HC could be used as a unique biomarker in severe COVID-19 and a potential therapeutic candidate for detecting the severity of COVID-19 and other infectious diseases.

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.

Associations among S100A4, Sphingosine-1-Phosphate, and Pulmonary Function in Patients with Chronic Obstructive Pulmonary Disease

Background. S100A4 is a member of the S100 calcium-binding protein family and is increased in patients with chronic obstructive pulmonary disease (COPD). Sphingosine-1-phosphate (S1P) is a naturally occurring bioactive sphingolipid, which regulates the adhesion between the cells and the extracellular matrix and affects cell migration and differentiation. The goal of this study was to analyze the correlations among S100A4, S1P, and pulmonary function among COPD patients. Methods. All 139 serum samples and 15 lung specimens were collected in COPD patients and control subjects. S100A4 and S1P were detected in two groups. The markers of fibrosis and epithelial-mesenchymal transition (EMT) were measured in the lungs of COPD patients and control subjects. Results. The protein expression of S100A4 was higher in the lungs and serum of COPD patients than control cases. Additionally, serum S100A4 was inversely associated with pulmonary function among COPD patients. Meanwhile, collagen deposition and EMT nuclear transcription factors were elevated in the lungs of COPD patients. Moreover, the protein expression of S1P was increased in the serum of COPD patients. Serum S1P was gradually increased along with pulmonary function decline in COPD patients. Further correlation analysis revealed that serum S1P was negatively associated with pulmonary function in COPD patients. Furthermore, there was a positive correlation between S1P and S100A4 in COPD patients. Conclusions. These results provide evidence that the elevation of S100A4 and S1P may be involved in the onset and progression of COPD.

Serum cadmium positively correlates with inflammatory cytokines in patients with chronic obstructive pulmonary disease

BACKGROUND

Cadmium is a ubiquitous toxic heavy metal and environmental toxicant. Inflammation exerts central roles in the process of chronic obstructive pulmonary disease (COPD). However, few epidemiological studies on the correlation between cadmium exposure and COPD are available. The aim of this study was to evaluate the correlations among serum cadmium, inflammatory cytokines and pulmonary function in COPD patients.

METHODS

All 940 COPD patients were finally recruited in this study. Demographic characteristics and clinical information were extracted. Fasting serum was collected. Serum cadmium was detected through graphite furnace atomic absorption spectrophotometry. Serum inflammatory cytokines were measured using enzyme-linked immunosorbent assay.

RESULTS

All patients were classified into three groups according to the tertile division of serum cadmium concentration: low (<0.77 μg/L, L), medium (0.77-1.01 μg/L, M), and high (1.01 μg/L, H). Logistic regression analysis found that serum cadmium was inversely correlated with pulmonary function before and after adjusted confounding variables. When stratified by gender, serum cadmium was still negatively correlated with pulmonary function in COPD patients. Moreover, higher serum cadmium elevated CAT (COPD Assessment Test) score before and after adjusted confounding variables. Though a non-linear association between serum cadmium and inflammatory cytokines, serum cadmium was positively associated with inflammatory cytokines (TNF-α and MCP-1). TNF-α and MCP-1 exerted a partial mediator in the association between cadmium exposure and pulmonary function decline in COPD patients.

CONCLUSIONS

Serum cadmium concentration is inversely correlated with pulmonary function among COPD patients. Inflammatory cytokines may be important mediators for cadmium-induced pulmonary function decline in COPD patients.

N-acetylcysteine alleviates pulmonary inflammatory response during benzo[a]pyrene-evoked acute lung injury

Benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon, exists widely in automobile emissions and polluted atmosphere. The current study aimed to describe pulmonary inflammation during BaP-induced acute lung injury (ALI). All mice except controls were intratracheally instilled with a single dose of BaP (90 μg per mouse). The alveolar structure was damaged, accompanied by numerous inflammatory cell infiltration around pulmonary interstitium and small airway. Airway wall area and mean linear intercept were reduced in BaP-exposed mouse lungs. By contrast, airway wall thickness and destructive index were elevated in BaP-exposed mouse lungs. Several inflammatory genes, such as Tnf-α, Il-1β, Il-6, Mip-2, Kc, and Mcp-1, were upregulated in mouse lungs. Phosphorylated IκBα was elevated in BaP-exposed mouse lungs. Nuclear translocation of NF-κB p65 and p50 was accordingly observed in BaP-exposed mouse lungs. Several molecules of the MAPK pathway, including JNK, ERK1/2, and p38, were activated in mouse lungs. Of interest, pretreatment with N-acetylcysteine (NAC), an antioxidant, alleviated BaP-induced ALI. Moreover, NAC attenuated BaP-induced inflammatory cell infiltration in mouse lungs and inflammatory gene upregulation in A549 cells. In addition, NAC attenuated BaP-induced NF-κB activation in A549 cells and mouse lungs. These results suggest that NAC alleviates pulmonary inflammatory response during BaP-evoked ALI.

Reactive oxygen species-evoked endoplasmic reticulum stress mediates 1-nitropyrene-induced epithelial-mesenchymal transition and pulmonary fibrosis

1-Nitropyrene (1-NP) is one component of atmospheric fine particles. Previous report revealed that acute 1-NP exposure induced respiratory inflammation. This study aimed to investigate whether chronic 1-NP exposure induces pulmonary fibrosis. Male C57BL6/J mice were intratracheally instilled to 1-NP (20 μg/mouse/week) for 6 weeks. Diffuse interstitial inflammation, a-smooth muscle actin (a-SMA)-positive cells, a marker of epithelial-mesenchymal transition (EMT), and an extensive collagen deposition, measured by Masson staining, were observed in 1-NP-exposed mouse lungs. Pulmonary function showed that lung dynamic compliance (Cydn-min) was reduced in 1-NP-exposed mice. Conversely, inspiratory resistance (Ri) and expiratory resistance (Re) were elevated in 1-NP-exposed mice. Mechanistically, cell migration and invasion were accelerated in 1-NP-exposed pulmonary epithelial cells. In addition, E-cadherin, an epithelial marker, was downregulated, and vimentin, a-SMA and N-cadherin, three mesenchymal markers, were upregulated in 1-NP-exposed pulmonary epithelial cells. Although TGF-β wasn't altered, phosphorylated Smad2/3 were enhanced in 1-NP-exposed pulmonary epithelial cells. Moreover, reactive oxygen species (ROS) were increased and endoplasmic reticulum (ER) stress was activated in 1-NP-exposed pulmonary epithelial cells. N-Acetylcysteine (NAC), an antioxidant, attenuated 1-NP-evoked excess ROS, ER stress and EMT in pulmonary epithelial cells. Similarly, pretreatment with NAC alleviated 1-NP-caused pulmonary EMT and lung fibrosis in mice. These results demonstrate that ROS-evoked ER stress contributes, at least partially, to 1-NP-induced EMT and pulmonary fibrosis.

Circulatory cadmium positively correlates with epithelial-mesenchymal transition in patients with chronic obstructive pulmonary disease

Environmental cadmium (Cd) exposure can cause several pulmonary diseases. Epithelial-mesenchymal transition (EMT) involved in the process of chronic obstructive pulmonary disease (COPD). However, the association between environmental Cd exposure and EMT was unclear in COPD patients. This study aimed to analyze the associations among circulatory Cd, EMT and COPD based on case-control study. Four hundred COPD patients and 400 control subjects were recruited. Circulatory Cd was detected using atomic adsorption spectrometer. MicroRNA-30 (miR-30) was measured by RT-PCR and the markers of pulmonary EMT were evaluated through western blotting. Circulatory Cd concentration was increased and serum miR-30 was decreased in COPD patients. Circulatory Cd was inversely associated with pulmonary function in COPD patients. Moreover, serum miR-30 was gradually decreased in parallel with FEV1 in COPD patients. Meanwhile, there was a negative association between serum miR-30 and circulatory Cd in COPD patients. Further analysis found that E-cadherin, one of epithelial biomarkers, was reduced in lung tissues of COPD patients with higher circulatory Cd. On the contrary, pulmonary N-cadherin, Vimentin and α-SMA, three of mesenchymal biomarkers, were increased in COPD patients with higher circulatory Cd. In vitro experiments revealed that Cd exposure repressed miR-30 levels and promoted EMT in BEAS-2B cells. Our results provide evidence that miR-30 reduction contributing to pulmonary EMT may involve in the process of Cd-induced 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01514-6.

The associations of serum S100A9 with the severity and prognosis in patients with community-acquired pneumonia: a prospective cohort study

BACKGROUND

Previous studies found that S100A9 may involve in the pathophysiology of community-acquired pneumonia (CAP). However, the role of S100A9 was unclear in the CAP. The goal was to explore the correlations of serum S100A9 with the severity and prognosis of CAP patients based on a prospective cohort study.

METHODS

A total of 220 CAP patients and 110 control subjects were recruited. Demographic and clinical data were collected. Serum S100A9 and inflammatory cytokines were measured.

RESULTS

Serum S100A9 was elevated in CAP patients on admission. Serum S100A9 was gradually elevated parallelly with CAP severity scores. Additionally, inflammatory cytokines were increased and blood routine parameters were changed in CAP patients compared with control subjects. Correlation analysis found that serum S100A9 was positively associated with CAP severity scores, blood routine parameters (WBC, NLR and MON) and inflammatory cytokines. Further, logistic regression analysis demonstrated that there were positive associations between serum S100A9 and CAP severity scores. Besides, the prognosis of CAP was tracked. Serum higher S100A9 on the early stage elevated the death of risk and hospital stay among CAP patients.

CONCLUSION

Serum S100A9 is positively correlated with the severity of CAP. On admission, serum higher S100A9 elevates the risk of death and hospital stay in CAP patients, suggesting that S100A9 may exert a certain role in the pathophysiology of CAP and regard as a serum diagnostic and managing biomarker for CAP.

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.

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.

Radiological screening of maternal periodontitis for predicting adverse pregnancy and neonatal outcomes

It is well known that periodontitis, diagnosed mainly by periodontal probing, is associated with adverse pregnancy outcomes. However, periodontal probing is time-consuming, highly discomforting, inaccurate, and invasive. We aimed to assess whether periodontitis severity based on radiological staging in accordance with the 2017 new consensus classification was related to adverse pregnancy and neonatal outcomes. The medical records of 165 mothers who underwent panoramic radiography within 5 years before and after the time of delivery and of their singleton neonates were retrospectively reviewed. Twenty-two mothers (13.3%) had severe periodontitis (SP), and 143 (86.7%) had mild or moderate periodontitis (MP). In relation to adverse pregnancy outcomes, uterine leiomyoma (18.2% vs. 4.2%, P = 0.029), chronic hypertension (9.1% vs. 0.7%, P = 0.047), and preeclampsia (13.6% vs. 2.1%, P = 0.032) occurred significantly more frequently in the SP group than in the MP group. The incidences of very preterm birth (13.6% vs. 1.4%, P = 0.017), extremely preterm birth (9.1% vs. 0.7%, P = 0.047), and small for gestational age (22.7% vs. 5.6%, P = 0.017) were also significantly higher in the SP group than in the MP group. Radiological screening of maternal periodontitis could be useful for predicting adverse pregnancy and neonatal outcomes as well as diagnosing SP in pregnant women.

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

PROBLEM

11β-Hydroxysteroid dehydrogenase 2 (11β-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 11β-HSD2. Nuclear factor-kappa B (NF-κB) is a transcription factor that regulates inflammatory signaling. This study aimed to investigate the association among 11β-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 11β-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

11β-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-1β, several inflammatory cytokines, were higher in SGA placentas. Correlation analysis showed that neonatal weight was positively associated with PPAR-γ and 11β-HSD2 in SGA placentas. By contrast, neonatal weight was inversely correlated with NF-κB p65 in SGA placentas. 11β-HSD2 was positively correlated with PPAR-γ in SGA placentas.

CONCLUSIONS

Inflammation-associated downregulation of placental PPAR-γ and 11β-HSD2 may be involved in SGA.

Calcitriol inhibits lipopolysaccharide-induced proliferation, migration and invasion of prostate cancer cells through suppressing STAT3 signal activation

Increasing evidence suggests that infection promotes the initiation and progression of prostate cancer. This study investigated the effects of lipopolysaccharide (LPS), a major component of Gram-negative bacilli, on proliferation, migration and invasion of prostate cancer cells and the protective effects of 1α,25(OH)2D3 (calcitriol). PC-3 and DU145 cells were stimulated with LPS (2.0 μg/mL) in the presence or absence of 1α,25(OH)2D3 (100 nM). Our results shown that 1α,25(OH)2D3 reduced the proportion of S phase cells in LPS-stimulated PC-3 and DU145 cells, and down-regulated the nuclear protein levels of Cyclin D1 and PCNA in LPS-stimulated PC-3 cells. In addition, 1α,25(OH)2D3 inhibited migration and invasion, as determined by wound healing and transwell assay, in LPS-stimulated PC-3 and DU145 cells. Of interest, we observed that 1α,25(OH)2D3 inhibits NF-κB activation and subsequent synthesis and secretion of IL-6 and IL-8 by promoting VDR and NF-κB p65 interaction. Surprisingly, 1α,25(OH)2D3 blocks nuclear translocation of pSTAT3 by promoting physical interaction between VDR and pSTAT3 (Tyr705) in LPS-stimulated PC-3 and DU145 cells. These results suggest that 1α,25(OH)2D3 inhibits LPS-induced proliferation, migration and invasion in prostate cancer cells by directly and indirectly blocking STAT3 signal transduction.

Tributyltin and triphenyltin induce 11β-hydroxysteroid dehydrogenase 2 expression and activity through activation of retinoid X receptor α

Exposure to the environmental pollutants organotins is of toxicological concern for the marine ecosystem and sensitive human populations, including pregnant women and their unborn children. Using a placenta cell model, we investigated whether organotins at nanomolar concentrations affect the expression and activity of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2). 11β-HSD2 represents a placental barrier controlling access of maternal glucocorticoids to the fetus. The organotins tributyltin (TBT) and triphenyltin (TPT) induced 11β-HSD2 expression and activity in JEG-3 placenta cells, an effect confirmed at the mRNA level in primary human trophoblast cells. Inhibition/knock-down of retinoid X receptor alpha (RXRα) in JEG-3 cells reduced the effect of organotins on 11β-HSD2 activity, mRNA and protein levels, revealing involvement of RXRα. Experiments using RNA and protein synthesis inhibitors indicated that the effect of organotins on 11β-HSD2 expression was direct and caused by increased transcription. Induction of placental 11β-HSD2 activity by TBT, TPT and other endocrine disrupting chemicals acting as RXRα agonists may affect placental barrier function by altering the expression of glucocorticoid-dependent genes and resulting in decreased availability of active glucocorticoids for the fetus, disturbing development and increasing the risk for metabolic and cardiovascular complications in later life.