Colonic expression of glutathione S-transferase alpha 4 and 4-hydroxynonenal adducts is correlated with the pathology of murine colitis-associated cancer.

Chronic inflammation-induced oxidative stress is an important driving force for developing colitis-associated cancer (CAC). 4-hydroxynonenal (4-HNE) is a highly reactive aldehyde derived from lipid peroxidation of ω-6 polyunsaturated fatty acids that contributes to colorectal carcinogenesis. Glutathione S-transferase alpha 4 (Gsta4) specifically conjugates glutathione to 4-HNE and thereby detoxifies 4-HNE. The correlation of these oxidative biomarkers with the pathological changes in CAC is, however, unclear. In this study, we investigated the expression of Gsta4 and 4-HNE adducts in azoxymethane/dextran sulfate sodium (AOM/DSS)-induced murine CAC, and analyzed the correlations of 4-HNE and Gsta4 with inflammatory cytokines and the pathological scores in the colon biopsies. Real-time quantitative PCR showed that expression of IL6, TNFα, and Gsta4 sequentially increased in colon tissues for mice treated with DSS for 1, 2, and 3 cycles, respectively. Moreover, immunohistochemical staining showed remarkably increased expression of 4-HNE adducts, Gsta4, TNFα, and IL6 in the colon biopsies after 3 cycles of DSS treatment. Correlation analysis demonstrated that 4-HNE adducts in the colon biopsies were positively correlated with Gsta4 expression. Additionally, the expression of Gsta4 and 4-HNE adducts were strongly correlated with the pathological changes of colon, as well as the expression of TNFα and IL6 in colon tissues. These results provide evidence for the association of oxidative biomarkers Gsta4 and 4-HNE with the pathological changes of CAC and may help developing novel histopathological biomarkers and prevention targets for CAC.

A deep learning nomogram of continuous glucose monitoring data for the risk prediction of diabetic retinopathy in type 2 diabetes.

Continuous glucose monitoring (CGM) data analysis will provide a new perspective to analyze factors related to diabetic retinopathy (DR). However, the problem of visualizing CGM data and automatically predicting the incidence of DR from CGM is still controversial. Here, we explored the feasibility of using CGM profiles to predict DR in type 2 diabetes (T2D) by deep learning approach. This study fused deep learning with a regularized nomogram to construct a novel deep learning nomogram from CGM profiles to identify patients at high risk of DR. Specifically, a deep learning network was employed to mine the nonlinear relationship between CGM profiles and DR. Moreover, a novel nomogram combining CGM deep factors with basic information was established to score the patients' DR risk. This dataset consists of 788 patients belonging to two cohorts: 494 in the training cohort and 294 in the testing cohort. The area under the curve (AUC) values of our deep learning nomogram were 0.82 and 0.80 in the training cohort and testing cohort, respectively. By incorporating basic clinical factors, the deep learning nomogram achieved an AUC of 0.86 in the training cohort and 0.85 in the testing cohort. The calibration plot and decision curve showed that the deep learning nomogram had the potential for clinical application. This analysis method of CGM profiles can be extended to other diabetic complications by further investigation.

Glutathione S-Transferase Alpha 4 Promotes Proliferation and Chemoresistance in Colorectal Cancer Cells.

Glutathione S-transferase alpha 4 (GSTA4) is a phase II detoxifying enzyme that is overexpressed in colorectal cancer (CRC) and regulated by the oncogenic transcription factor AP-1. However, the role of GSTA4 in these CRC cells remains unclear. In this study, we investigated the roles of GSTA4 in the CRC cells by inactivating GSTA4 in HCT116 human CRC cells (Defined as HCT116ΔGSTA4) using the CRISPR/Cas9 gene editing. Cell proliferation, clonogenicity, and susceptibility to chemotherapeutic drugs were analyzed in vitro and in a xenograft model. The results showed that loss of GSTA4 significantly decreased cell proliferation and clonogenicity, whereas it increased intracellular reactive oxygen species and cell susceptibility to 5-fluorouracil (5-FU) and oxaliplatin. Additionally, exposure of HCT116ΔGSTA4 cells to 5-FU increased the expression of γH2AX, a hallmark of double-stranded DNA breaks. In contrast, no remarkably increased γH2AX was noted in oxaliplatin-treated HCT116ΔGSTA4 cells compared with HCT116 cells. Moreover, loss of GSTA4 blocked the AKT and p38 MAPK pathways, leading to proliferative suppression. Finally, the xenograft model showed decreased tumor size for HCT116ΔGSTA4 cells compared with HCT116 cells, confirming in vitro findings. These findings suggest that GSTA4 is capable of promoting proliferation, tumorigenesis, and chemoresistance and is a potential target for CRC therapy.

Extracellular superoxide produced by Enterococcus faecalis reduces endometrial receptivity via inflammatory injury.

PROBLEM: Chronic endometritis (CE) can cause infertility. Enterococcus faecalis is an opportunistic pathogen that is often found in the endometrium of CE patients. However, the mechanisms by which E. faecalis affects endometrial health are still unclear. In this study, we investigated the mechanism how extracellular superoxide produced by E. faecalis affected the endometrial receptivity. METHOD OF STUDY: Superoxide production was blocked by deleting menB gene in E. faecalis OG1RF. Endometrial epithelial cells were infected by superoxide-producing E. faecalis OG1RF and superoxide-deficient strain WY84. Inflammatory cytokines, apoptosis, and biomarkers for the endometrial receptivity were analyzed. RESULTS: Infection of endometrial epithelial cells with superoxide-producing E. faecalis OG1RF induced expression of inflammatory cytokines, promoted apoptosis, and down-regulated expression of receptivity biomarkers compared to uninfected control. In contrast, superoxide-deficient E. faecalis WY84 had little effect on inflammatory cytokine production, apoptosis, and endometrial receptivity biomarkers. CONCLUSIONS: Extracellular superoxide produced by E. faecalis is an important virulence factor for E. faecalis-induced endometritis leading to reduced receptivity of endometrial epithelial cells.

The need for contraception in patients taking prescription drugs: a review of FDA warning labels, duration of effects, and mechanisms of action.

Introduction: This review provides a guide for the rational use of prescription drugs in patients of reproductive age. Areas covered: A comprehensive retrieval of the labels of FDA-approved drugs was performed to identify drugs where the label recommends contraceptive use during and/or after treatment. The acquired data were analyzed and organized into a table. Contraception was recommended or mandated for 268 single-ingredient drugs. These could be divided into four main categories, with many having effects across several categories: 177 drugs required contraception because they were associated with pregnancy loss or stillbirth, 177 drugs were associated with teratogenesis, 136 were associated with non-teratogenic adverse peri- or postnatal effects on the fetus (e.g. low birth weight), and 44 were associated with decreased efficacy of contraception or a change in ovulatory cycle. We also discuss the period of time contraception is required, as well as the known or hypothesized reasons for the reproductive toxicity of these agents. Expert opinion: We have provided a comprehensive overview of the FDA-approved drugs where the warning labels currently stipulate that contraception should be used. Although other references are available for clinicians, this review provides a useful source of information regarding the single-ingredient prescription drugs that may affect the outcome of pregnancy. This information is particularly relevant for researchers, as it provides an overview of the different drugs with reproductive toxicity, and because it highlights the specific needs for future research. In particular, more work (especially epidemiological studies) is needed to clarify the clinical relevance of these findings, most of which were obtained through animal studies.

Therapeutic monoclonal antibodies and clinical laboratory tests: When, why, and what is expected?

BACKGROUND: We herein provide an overview of the clinical laboratory tests that should be performed before, during and after using therapeutic monoclonal antibodies (mAbs) and the clinical laboratory tests that may be affected by mAbs. METHODS: The labels of FDA-approved therapeutic mAbs were downloaded from DailyMed (the official website for drug labels) and were used as the sources of data for this review. RESULTS: It was found that most of the labels provided information relevant to the clinical laboratory tests, including the tests needed before mAbs treatment to check the patients' background status and to identify potentially sensitive patients, the tests needed during or after the treatment to evaluate the patients' response, and the mAbs that may lead to false positive or negative results for clinical laboratory tests. CONCLUSIONS: The present findings will be of interest to physicians, laboratory scientists, those involved in drug development and surveillance and individuals making health care policy.

FDA-approved medications that impair human spermatogenesis.

We herein provide an overview of the single-ingredient U.S. Food and Drug Administration (FDA)-approved drugs that affect human spermatogenesis, potentially resulting in a negative impact on male fertility. To provide this information, we performed an in-depth search of DailyMed, the official website for FDA-approved drug labels. Not surprisingly, hormone-based agents were found to be the drugs most likely to affect human spermatogenesis. The next category of drugs most likely to have effects on spermatogenesis was the antineoplastic agents. Interestingly, the DailyMed labels indicated that several anti-inflammatory drugs affect spermatogenesis, which is not supported by the peer-reviewed literature. Overall, there were a total of 65 labels for drugs of various classes that showed that they have the potential to affect human sperm production and maturation. We identified several drugs indicated to be spermatotoxic in the drug labels that were not reported in the peer-reviewed literature. However, the details about the effects of these drugs on human spermatogenesis are largely lacking, the mechanisms are often unknown, and the clinical impact of many of the findings is currently unclear. Therefore, additional work is needed at both the basic research level and during clinical trials and post-marketing surveillance to fill the gaps in the current knowledge. The present findings will be of interest to physicians and pharmacists, researchers, and those involved in drug development and health care policy.

Fibroblast-derived tenascin-C promotes Schwann cell migration through ß1-integrin dependent pathway during peripheral nerve regeneration.

Peripheral nerve regeneration requires precise coordination and dynamic interaction among various types of cells in the tissue. It remains unclear, however, whether the cellular crosstalk between fibroblasts and Schwann cells (SCs) is related to phenotype modulation of SCs, a critical cellular process after peripheral nerve injury. In this study, microarray analysis revealed that a total of 6,046 genes were differentially expressed in the proximal nerve segment after sciatic nerve transection in rats, and bioinformatics analysis further identified tenascin-C (TNC), an extracellular matrix (ECM) protein, as a key gene regulator. TNC was abundantly produced by nerve fibroblasts accumulating at the lesion site, rather than by SCs as usually expected. TNC significantly promoted SC migration without effects on SC proliferation in primary culture. In co-culture of fibroblasts and SCs, inhibition of TNC expression either by siRNA transfection or antibody blockade could suppress SC migration, while TNC-stimulated SC migration was mediated by TNC binding to ß1-integrin receptor in SCs through activation of Rac1 effectors. The in vivo evidence showed that exogenous TNC protein enhanced SC migration and axonal regrowth. Our results highlight that TNC-mediated cellular interaction between fibroblasts and SCs may regulate SC migration through ß1-integrin-dependent pathway during peripheral nerve regeneration.

Hypoxia-Induced Upregulation of miR-132 Promotes Schwann Cell Migration After Sciatic Nerve Injury by Targeting PRKAG3.

Following peripheral nerve injury, hypoxia is formed as a result of defects in blood supply at the injury site. Despite accumulating evidence on the effects of microRNAs (miRNAs) on phenotype modulation of Schwann cells (SCs) after peripheral nerve injury, the impact of hypoxia on SC behaviors through miRNAs during peripheral nerve regeneration has not been estimated. In this study, we confirmed our previous microarray data on the upregulation of miR-132 after sciatic nerve injury in rats and observed that overexpression of miR-132 significantly promoted cell migration of primary cultured SCs. Interestingly, hypoxia-increased expression of miR-132 also enhanced SC migration while inhibition of miR-132 suppressed hypoxia-induced increase in SC migration. miR-132 downregulated PRKAG3 through binding to its 3'-UTR, and PRKAG3 knockdown compromised the reducing effect of miR-132 inhibition on SC migration under normal or hypoxia condition. Moreover, in vivo injection of miR-132 agomir into rats with sciatic nerve transection accelerated SC migration from the proximal to distal stump. Overall, our results suggest that the hypoxia-induced upregulation of miR-132 could promote SC migration and facilitate peripheral nerve regeneration.

Identification and functional annotation of novel microRNAs in the proximal sciatic nerve after sciatic nerve transection.

The peripheral nervous system is able to regenerate after injury, and regeneration is associated with the expression of many genes and proteins. MicroRNAs are evolutionarily conserved, small, non-coding RNA molecules that regulate gene expression at the level of translation. In this paper, we focus on the identification and functional annotation of novel microRNAs in the proximal sciatic nerve after rat sciatic nerve transection. Using Solexa sequencing, computational analysis, and quantitative reverse transcription PCR verification, we identified 98 novel microRNAs expressed on days 0, 1, 4, 7, and 14 after nerve transection. Furthermore, we predicted the target genes of these microRNAs and analyzed the biological processes in which they were involved. The identified biological processes were consistent with the known time-frame of peripheral nerve injury and repair. Our data provide an important resource for further study of the role and regulation of microRNAs in peripheral nerve injury and regeneration.