Maternal, umbilical arterial metabolic levels and placental Nrf2/CBR1 expression in pregnancies with and without 25-hydroxyvitamin D deficiency

BACKGROUND

The aim of this case-control study was to document maternal, umbilical arterial metabolic levels and correlations in pregnancies with and without 25-hydroxyvitamin D [25(OH)D] deficiency, while, also investigating the expression of nuclear factor erythroid 2 related factor 2 (Nrf2) and carbonyl reductase 1 (CBR1) in the placenta.

METHODS

One hundred participants, 50 deficient for 25(OH)D and 50 normal, were recruited from among hospitalized single-term pregnant women who had elected for cesarean section. Umbilical arterial and placental samples were collected during cesarean section. Metabolic levels were assessed for the 25(OH)D deficiency and control groups' maternal, umbilical arterial samples. Nrf2 and CBR1 expression levels were investigated in the placentas of 12 pregnant women with 25(OH)D deficiency and 12 controls.

RESULTS

Compared with the control participants, the 25(OH)D deficient women had significantly higher triglyceride (TG) levels (3.80 ± 2.11 vs. 2.93 ± 1.16 mmol/L, 3.64 ± 1.84 vs. 2.81 ± 1.16 mmol/L, p < .01, .001); lower high density lipoprotein cholesterol (HDL-C) levels (1.54 ± 0.32 vs. 1.82 ± 0.63 mmol/L, 1.41 ± 0.72 vs. 2.44 ± 1.68 mmol/L, p < .001, .01) in both material blood and the umbilical artery. In addition, Nrf2 and CBR1 expression levels were lower in the maternal 25(OH)D deficient placenta.

CONCLUSION

25(OH)D deficient pregnant women have higher TG levels and lower HDL-C levels in both material blood and the umbilical artery. TG level is negatively correlated with 25(OH)D in both the maternal serum and infant umbilical artery. 25(OH)D deficiency also lowers placental expression of Nrf2 and CBR1.

Supplemental data for this article is available online at here.

Transcription of carbonyl reductase 1 is regulated by DNA topoisomerase II beta

DNA topoisomerase II beta (TOP2B) has a role in transcriptional regulation. Here, to further investigate transcriptional regulation by TOP2B, we used RNA-sequencing and real-time PCR to analyse the differential gene expression profiles of wild-type and two independent TOP2B-null pre-B Nalm-6 cell lines, one generated by targeted insertion and the other using CRISPR-Cas9 gene editing. We identified carbonyl reductase 1 (CBR1) among the most significantly downregulated genes in these TOP2B-null cells. Reduced CBR1 expression was accompanied by loss of binding of the transcription factors USF2 and MAX to the CBR1 promoter. We describe possible mechanisms by which loss of TOP2B results in CBR1 downregulation. To our knowledge, this is the first report of a link between TOP2B and CBR1.

Upregulation of Carbonyl Reductase 1 by Nrf2 as a Potential Therapeutic Intervention for Ischemia/ Reperfusion Injury during Liver Transplantation

Currently, liver transplantation is the only available remedy for patients with end-stage liver disease. Conservation of transplanted liver graft is the most important issue as it directly related to patient survival. Carbonyl reductase 1 (CBR1) protects cells against oxidative stress and cell death by inactivating cellular membrane-derived lipid aldehydes. Ischemia-reperfusion (I/R) injury during living-donor liver transplantation is known to form reactive oxygen species. Thus, the objective of this study was to investigate whether CBR1 transcription might be increased during liver I/R injury and whether such increase might protect liver against I/R injury. Our results revealed that transcription factor Nrf2 could induce CBR1 transcription in liver of mice during I/R. Pre-treatment with sulforaphane, an activator of Nrf2, increased CBR1 expression, decreased liver enzymes such as aspartate aminotransferase and alanine transaminase, and reduced I/R-related pathological changes. Using oxygenglucose deprivation and recovery model of human normal liver cell line, it was found that oxidative stress markers and lipid peroxidation products were significantly lowered in cells overexpressing CBR1. Conversely, CBR1 knockdown cells expressed elevated levels of oxidative stress proteins compared to the parental cell line. We also observed that Nrf2 and CBR1 were overexpressed during liver transplantation in clinical samples. These results suggest that CBR1 expression during liver I/R injury is regulated by transcription factor Nrf2. In addition, CBR1 can reduce free radicals and prevent lipid peroxidation. Taken together, CBR1 induction might be a therapeutic strategy for relieving liver I/R injury during liver transplantation.

Overexpression of carbonyl reductase 1 inhibits malignant behaviors and epithelial mesenchymal transition by suppressing TGF-β signaling in uterine leiomyosarcoma cells

Carbonyl reductase 1 (CBR1) has been reported to be involved in cancer progression. Recently, we found that CBR1 overexpression inhibited malignant behaviors and the epithelial mesenchymal transition (EMT) in uterine cervical cancer. It remained unclear whether this was also the case in uterine leiomyosarcoma (uLMS), which is derived from mesenchymal cells and is a much more malignant gynecological tumor. A number of previous studies suggested that malignant behaviors are associated with EMT, even in mesenchymal malignant tumors. In the present study, we investigated whether CBR1 inhibits malignant behaviors and EMT in uLMS. We established clones of uLMS cells (SKN cells) and uterine sarcoma cells (MES-SA cells) that overexpressed CBR1. Cell proliferative, migratory and invasive activities were suppressed by CBR1 overexpression, accompanied by increases in the expressions of epithelial markers (E-cadherin and cytokeratin) and decreases in the expressions of mesenchymal markers (N-cadherin and fibronectin), suggesting that CBR1 overexpression inhibits malignant behaviors and EMT in uLMS cells. In addition, transforming growth factor-β (TGF-β) production and the subsequent signaling and phosphorylation of Smad were suppressed in the clones. To investigate the association between TGF-β and EMT, SKN cells were treated with TGF-β or a TGF-β receptor blocker (SB431542). EMT was promoted by TGF-β and inhibited by SB431542. In conclusion, this is the first study, to the best of the authors' knowledge, showing that CBR1 overexpression inhibits malignant behaviors and EMT in uLMS cells. The present study provided novel insight demonstrating that the suppressive effect of CBR1 is mediated through TGF-β signaling.

Low carbonyl reductase 1 expression is associated with poor prognosis in patients with oral squamous cell carcinoma

Carbonyl reductase 1 (CBR1) is an enzyme that catalyzes the reduction of numerous compounds by using NADPH-dependent oxidoreductase activity. Decreased expression of CBR1 is associated with disease progression and an unfavorable outcome in several types of malignancies. The purpose of the current study was to determine whether CBR1 expression could be a useful prognostic factor in patients with oral squamous cell carcinoma (OSCC). Therefore, its mechanisms of action were investigated in order to understand how CBR1 affects cancer cell behavior in vitro. CBR1 expression was evaluated using immunohistochemistry and tissue samples obtained from 90 patients with OSCC. The associations between CBR1 expression, clinicopathological characteristics and patient survival were also analyzed. In addition, the role of CBR1 in cancer cell invasion and metastasis was examined, along with its underlying molecular mechanisms, via transfecting CBR1-siRNA into the HSC2 human OSCC cell line. Immunohistochemical analysis revealed that biopsy tissue samples of 71.1% of the patients with OSCC were positive for CBR1. In addition, CBR1 expression status was correlated with the N classification (P<0.0001), stage (P=0.0018) and outcome (P=0.0095). Furthermore, a statistical correlation was determined between the protein expression status and overall survival (P=0.0171). In vitro studies indicated that the suppression of CBR1 by CBR1-siRNA increased cancer cell proliferative, wound healing and migratory abilities. These findings suggest that low expression levels of CBR1 may affect cancer prognosis, and that CBR1 may have potential as a prognostic factor for patients with OSCC.

Decreased carbonyl reductase 1 expression promotes tumor growth via epithelial mesenchymal transition in uterine cervical squamous cell carcinomas

Purpose

Carbonyl reductase 1 (CBR1) is involved in cancer progression. Recently, the authors reported that the loss of CBR1 expression is associated with a poor prognosis in uterine cervical cancer. Here, we investigated whether the decreased CBR1 expression promotes cancer progression by inducing the epithelial mesenchymal transition (EMT).

Methods

Antisense constructs of CBR1 complementary DNA (antisense clones) and the empty vectors (control clones) were transfected into human uterine cervical squamous cell carcinoma cell lines (SKG II and SiHa) and the proliferation and EMT marker expression of these clones were analyzed in vitro. In an in vivo study, 10⁷ cells of the antisense and control clones were subcutaneously injected into nude mice and the tumorigenesis was observed for 8 weeks.

Results

With the decreased CBR1 expression, the proliferation of the antisense clones increased, accompanied by a decrease in epithelial markers (E-cadherin and cytokeratin) and an increase in mesenchymal markers (fibronectin, alpha-smooth muscle actin, and N-cadherin), which suggests EMT induction. In the in vivo study, the tumor volume in the antisense group was significantly larger than that in the control group.

Conclusion

Decreased CBR1 expression promotes tumor growth by inducing EMT in uterine cervical squamous cell carcinomas.

Inhibition of Carbonyl Reductase 1 Safely Improves the Efficacy of Doxorubicin in Breast Cancer Treatment

AIMS

Doxorubicin (DOX) is a chemotherapeutic drug that is used to treat many cancers, but its use is limited by cardiotoxic side effect. Carbonyl reductase 1 (CBR1) is an NADPH-dependent oxidoreductase that reduces DOX to doxorubicinol (DOXOL), a less potent derivative that is responsible for DOX cardiotoxicity. Thus, we aimed to demonstrate that inhibition of CBR1 enhances the chemotherapeutic efficacy of DOX and attenuates cardiotoxicity.

RESULTS

Pharmacological or genetic inhibition of CBR1 improved the anticancer effects of DOX in preclinical models of breast cancer. RNA interference or chemical inhibition of CBR1 improved the anticancer effect of DOX in breast cancer. Moreover, CBR1 overexpression enabled breast cancer cells to obtain chemotherapeutic resistance to DOX treatment. Intriguingly, inhibition of CBR1 decreased DOX-induced cardiotoxicity in animal model. Innovation and Conclusions: Inhibition of CBR1 increases chemotherapeutic efficacy of DOX and reduces cardiotoxicity by blocking DOX reduction to DOXOL. Therefore, we offer preclinical proof-of-concept for a combination strategy to safely leverage the efficacy of doxorubicin by blunting its cardiotoxic effects that limit use of this cytotoxic agent used widely in the oncology clinic. Antioxid. Redox Signal. 26, 70-83.

RACK1 promotes hepatocellular carcinoma cell survival via CBR1 by suppressing TNF-α-induced ROS generation

It has been reported that intracellular accumulation of reactive oxygen species (ROS) has a significant role in tumor necrosis factor (TNF)-α-induced cell apoptosis and necrosis; however, the key molecules regulating ROS generation remain to be elucidated. The present study reports that knockdown of endogenous receptor for activated C kinase 1 (RACK1) increases the intracellular ROS level following TNF-α or H₂O₂ stimulation in human hepatocellular carcinoma (HCC) cells, leading to promotion of cell death. Carbonyl reductase 1 (CBR1), a ubiquitous nicotinamide adenine dinucleotide phosphate-dependent enzyme, is reported to protect cells from ROS-induced cell damage. The present study reports that RACK1 is a regulator of CBR1 that interacts with and sustains the protein stability of CBR1. Overexpression of CBR1 reverses the enhanced cell death due to RACK1 knockdown. Taken together, the results of the present study suggest that RACK1 protects HCC cells from TNF-α-induced cell death by suppressing ROS generation through interacting with and regulating CBR1.

Bioactivation of loxoprofen to a pharmacologically active metabolite and its disposition kinetics in human skin

Loxoprofen (LX) is a prodrug-type non-steroidal anti-inflammatory drug which is used not only as an oral drug but also as a transdermal formulation. As a pharmacologically active metabolite, the trans-alcohol form of LX (trans-OH form) is generated after oral administration to humans. The objectives of this study were to evaluate the generation of the trans-OH form in human in vitro skin and to identify the predominant enzyme for its generation. In the permeation and metabolism study using human in vitro skin, both the permeation of LX and the formation of the trans-OH form increased in a time- and dose-dependent manner after the application of LX gel to the skin. In addition, the characteristics of permeation and metabolism of both LX and the trans-OH form were examined by a mathematical pharmacokinetic model. The K_m value was calculated to be 10.3 mm in the human in vitro skin. The predominant enzyme which generates the trans-OH form in human whole skin was identified to be carbonyl reductase 1 (CBR1) by immunodepletion using the anti-human CBR1 antibody. The results of the enzyme kinetic study using the recombinant human CBR1 protein demonstrated that the K_m and V_max values were 7.30 mm and 402 nmol/min/mg protein, respectively. In addition, it was found that no unknown metabolites were generated in the human in vitro skin. This is the first report in which LX is bioactivated to the trans-OH form in human skin by CBR1. Copyright © 2015 John Wiley & Sons, Ltd.