Overexpression of miR-506-3p Aggravates DBP-Induced Testicular Oxidative Stress in Rats by Downregulating ANXA5 via Nrf2/HO-1 Signaling Pathway

Protective effects of black ginseng on testicular toxicity induced by Di-n-butyl phthalate in rats

Di-n-butyl phthalate (DBP) is a phthalate-based material used as a plasticizer to soften polyvinyl chloride, and classified as an endocrine disruptor with antiandrogen effects. Exposure to DBP induces oxidative stress in rat testes, resulting in testicular toxicity. Black ginseng (BG) exhibits a higher antioxidant activity than white or red ginseng following repeated heat treatment and processing. This study aimed to investigate whether the antioxidant activity of BG might protect against DBP-induced testicular toxicity in juvenile Sprague-Dawley rats. A significant decrease in testicular weight was observed in most groups treated with DBP alone or in combination with BG. However, a significant testicular weight increase was detected after exposure to BG (10 ml/kg) + DBP (500 mg/kg). The epididymal weight was significantly reduced with associated histological changes including irregular arrangement, atrophy of seminiferous tubules and Sertoli cells, and Leydig cell damage following exposure to DBP alone as well as BG (2.5 ml/kg) + DBP (500 mg/kg). However, no marked changes were observed in the shape of seminiferous tubules in control and BG + DBP groups. A significant decrease in serum testosterone levels was found after exposure to DBP, but no marked alterations in the BG + DBP groups. Protein expression levels of nuclear factor erythroid-derived 2-related factor (Nrf2), NAD(P)H dehydrogenase 1 (NQO1), and, heme oxygenase-1; (HO-1) were significantly higher following DBP treatment, but lowered in the BG + DBP groups. Evidence indicates that BG exerts a protective effect against DBP-induced testicular toxicity in rats.

Di-n-butyl phthalate induces toxicity in male fetal mouse testicular development by regulating the MAPK signaling pathway

"White pollution" has a significant impact on male reproduction. Di-n-butyl phthalate (DBP) is one of the most important factors in this type of pollution. Currently, research from international sources has demonstrated the significant reproductive toxicity of DBP. However, most of these studies have focused mainly on hormones expression at the protein and mRNA levels and the specific molecular targets of DBP and its mechanisms of action remain unclear. In this study, we established a Sprague Dawley pregnant mouse model exposed to DBP, and all male offspring were immediately euthanized at birth and bilateral testes were collected. We found through transcriptome sequencing that cell apoptosis and MAPK signaling pathway are the main potential pathways for DBP induced reproductive toxicity. Molecular biology analyses revealed a significant increase in the protein levels of JNK1(MAPK8) and BAX, as well as a significant increase in the BAX/BCL2 ratio after DBP exposure. Therefore, we propose that DBP induces reproductive toxicity by regulating JNK1 expression to activate the MAPK signaling pathway and induce reproductive cell apoptosis. In conclusion, our study provides the first evidence that the MAPK signaling pathway is involved in DBP-induced reproductive toxicity and highlights the importance of JNK1 as a potential target of DBP in inducing reproductive toxicity.

Curcumin strengthens a spontaneous self-protective mechanism-SP1/PRDX6 pathway, against di-n-butyl phthalate-induced testicular ferroptosis damage

As one of the common plasticizers, di-n-butyl phthalate (DBP) has been using in various daily consumer products worldwide. Since it is easily released from products and exists in the environment for a long time, it has a lasting impact on human health, especially male reproductive health. However, the detailed mechanism of testicular damage from DBP and the protection strategy are still not clear enough. In this study, we found that DBP could induce dose-dependent ferroptosis in testicular tissue. Mechanism dissection indicates that DBP can upregulate SP1 expression, which could directly transcriptionally upregulate PRDX6, a negative regulator of ferroptosis. Overexpression of PRDX6 or adding SP1 agonist curcumin could suppress the DBP-induced ferroptosis on testicular cells. In vivo, rats were given 500 mg/kg/day DBP orally for 3 weeks; elevated levels of ferroptosis were detected in testicular tissue. When the above-mentioned doses of DBP and curcumin at a dose of 300 mg/kg/day were administered intragastrically simultaneously, the testicular ferroptosis induced by DBP was alleviated. Immunohistochemistry and quantitative real-time PCR of testis tissue showed that the expression of PRDX6 was upregulated under the action of DBP and curcumin. These findings suggest a spontaneous self-protection mechanism of testicular tissue from DBP damage by upregulating SP1 and PRDX6. However, it is not strong enough to resist the DBP-induced ferroptosis. Curcumin can strengthen this self-protection mechanism and weaken the level of ferroptosis induced by DBP. This study may help us to develop a novel therapeutic option with curcumin to protect the testicular tissue from ferroptosis and function impairment by DBP.

Identifying Oxidized Lipid Metabolism-Related LncRNAs as Prognostic Biomarkers of Head and Neck Squamous Cell Carcinoma

The relationship between oxidized lipid metabolism and the immunological function of cancer is well known. However, the functions and regulatory mechanisms of lncRNAs associated with oxidized lipid metabolism in head and neck squamous cell carcinoma (HNSCC) remain to be fully elucidated. In this study, we established an oxidized lipid metabolism-related lncRNA prognostic signature to assess the prognosis and immune infiltration of HNSCC patients. The HNSCC transcriptome was obtained from The Cancer Genome Atlas. The choice of the target genes with a relevance score greater than 10 was performed via a correlation analysis by GeneCards. Patients were categorized by risk score and generated with multivariate Cox regression, which was then validated and evaluated using the Kaplan–Meier analysis and time-dependent receiver operating characteristics (ROC). A nomogram was constructed by combining the risk score with the clinical data. We constructed a risk score with 24 oxidized lipid metabolism-related lncRNAs. The areas’ 1-, 2-, and 3-year OS under the ROC curve (AUC) were 0.765, 0.724, and 0.724, respectively. Furthermore, the nomogram clearly distinguished the survival probabilities of patients in high- and low-risk groups, between which substantial variations were revealed by immune infiltration analysis. The results supported the fact that oxidized lipid metabolism-related lncRNAs might predict prognoses and assist with differentiating amid differences in immune infiltration in HNSCC.

Integrative proteomics and m6A microarray analyses of the signatures induced by METTL3 reveals prognostically significant in gastric cancer by affecting cellular metabolism

METTL3-mediated RNA N6-methyladenosine (m6A) is the most prevalent modification that participates in tumor initiation and progression via governing the expression of their target genes in cancers. However, its role in tumor cell metabolism remains poorly characterized. In this study, m6A microarray and quantitative proteomics were employed to explore the potential effect and mechanism of METTL3 on the metabolism in GC cells. Our results showed that METTL3 induced significant alterations in the protein and m6A modification profile in GC cells. Gene Ontology (GO) enrichment indicated that down-regulated proteins were significantly enriched in intracellular mitochondrial oxidative phosphorylation (OXPHOS). Moreover, the protein-protein Interaction (PPI) network analysis found that these differentially expressed proteins were significantly associated with OXPHOS. A prognostic model was subsequently constructed based on the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, and the high-risk group exhibited a worse prognosis in GC patients. Meanwhile, Gene Set Enrichment Analysis (GSEA) demonstrated significant enrichment in the energy metabolism signaling pathway. Then, combined with the results of the m6A microarray analysis, the intersection molecules of DEPs and differential methylation genes (DMGs) were significantly correlated with the molecules of OXPHOS. Besides, there were significant differences in prognosis and GSEA enrichment between the two clusters of GC patients classified according to the consensus clustering algorithm. Finally, highly expressed and highly methylated molecules regulated by METTL3 were analyzed and three (AVEN, DAZAP2, DNAJB1) genes were identified to be significantly associated with poor prognosis in GC patients. These results signified that METTL3-regulated DEPs in GC cells were significantly associated with OXPHOS. After combined with m6A microarray analysis, the results suggested that these proteins might be implicated in cell energy metabolism through m6A modifications thus influencing the prognosis of GC patients. Overall, our study revealed that METTL3 is involved in cell metabolism through an m6A-dependent mechanism in GC cells, and indicated a potential biomarker for prognostic prediction in GC.

Erectile dysfunction in hypospadiac male adult rats induced by maternal exposure to di-n-butyl phthalate

For the treatment of hypospadias, a significant number of studies focus on penile reconstruction. However, scant attention is given to sexual behavior of hypospadiac patients and underlying mechanisms. A rat model of hypospadias was constructed by maternal di-n-butyl phthalate (DBP) exposure (800 mg/kg/day by gavage during gestational days 14-18). Ten-week-old male rats with hypospadias undertook significantly decreased penis/body weight ratio, reduced testis/body weight ratio, lower serum testosterone level and thinner myelin sheath thickness of cavernosum nerves. Meanwhile, erectile dysfunction (ED) was found in hypospadiac rats, which showed significant increases in transforming growth factor-β1 (TGF-β1) protein expression and decreases in the expression of alpha smooth muscle actin (α-SMA) protein, neuronal and endothelial nitric oxide synthase protein (nNOS and eNOS). In addition, phosphorylated protein kinase B/protein kinase B (pAkt/Akt) ratios were remarkably lower, but the Bcl-2-associated X protein (Bax)/Bcl-2 ratios, caspase-3 protein expression, nuclear factor erythroid 2-related factor 2/ Kelch-like ECH-associated protein 1 (Nrf2/Keap-1) ratios, NAD(P)H dehydrogenase quinone 1(NQO1) protein expression and heme oxygenase-1 (HO-1) protein expression were higher in the hypospadias groups than the control group. Notably, ED is comorbid with hypospadias in cases. Penile fibrosis, testosterone deficiency, and endothelial dysfunction lead to ED in hypospadias induced by DBP eventually, which might be explained by activating Akt/Bad/Bax/caspase-3 pathway, Nrf2/Keap-1 pathway and suppressing NOS/cGMP pathway in penis.

Perfluorooctane sulfonate induces suppression of testosterone biosynthesis via Sertoli cell-derived exosomal/miR-9-3p downregulating StAR expression in Leydig cells

Perfluorooctane sulfonate (PFOS) is associated with male reproductive disorder, but the related mechanisms are still unclear. In this study, we used in vivo and in vitro models to explore the role of Sertoli cell-derived exosomes (SC-Exo)/miR-9-3p/StAR signaling pathway on PFOS-induced suppression of testosterone biosynthesis. Forty male ICR mice were orally administrated PFOS (0.5-10 mg/kg/bw) for 4 weeks. Bodyweight, organ index, sperm count, reproductive hormones were evaluated. Primary Sertoli cells and Leydig cells were used to delineate the molecular mechanisms that mediate the effects of PFOS on testosterone biosynthesis. Our results demonstrated that PFOS dose-dependently induced a decrease in sperm count, low levels of testosterone, and damage in testicular interstitium morphology. In vitro models, PFOS significantly increased miR-9-3p levels in Sertoli cells and SC-Exo, accompanied by a decrease in testosterone secretion and StAR expression in Leydig cells when Leydig cells were exposed to SC-Exo. Meanwhile, inhibition of SC-Exo or miR-9-3p by their inhibitors significantly rescued PFOS-induced decreases in testosterone secretion and the mRNA and protein expression of the StAR gene in Leydig cells. In summary, the present study highlights the role of the SC-Exo/miR-9-3p/StAR signaling pathway in PFOS-induced suppression of testosterone biosynthesis, advancing our understanding of molecular mechanisms for PFOS-induced male reproductive disorders.

Knockdown of circ_0003928 ameliorates high glucose-induced dysfunction of human tubular epithelial cells through the miR-506-3p/HDAC4 pathway in diabetic nephropathy

Background

Previous data have indicated the importance of circular RNA (circRNA) in the pathogenesis of diabetic nephropathy (DN). The study is designed to investigate the effects of circ_0003928 on oxidative stress and apoptosis of high glucose (HG)-treated human tubular epithelial cells (HK-2) and the underlying mechanism.

Methods

The DN cell model was established by inducing HK-2 cells using 30 mmol/L D-glucose. RNA expression of circ_0003928, miR-506-3p and histone deacetylase 4 (HDAC4) was detected by quantitative real-time polymerase chain reaction. Cell viability and proliferation were investigated by cell counting kit-8 and 5-Ethynyl-29-deoxyuridine (EdU) assays, respectively. Oxidative stress was evaluated by commercial kits. Caspase 3 activity and cell apoptotic rate were assessed by a caspase 3 activity assay and flow cytometry analysis, respectively. Protein expression was detected by Western blotting analysis. The interactions among circ_0003928, miR-506-3p and HDAC4 were identified by dual-luciferase reporter and RNA pull-down assays.

Results

Circ_0003928 and HDAC4 expression were significantly upregulated, while miR-506-3p was downregulated in the serum of DN patients and HG-induced HK-2 cells. HG treatment inhibited HK-2 cell proliferation, but induced oxidative stress and cell apoptosis; however, these effects were reversed after circ_0003928 depletion. Circ_0003928 acted as a miR-506-3p sponge, and HDAC4 was identified as a target gene of miR-506-3p. Moreover, the circ_0003928/miR-506-3p/HDAC4 axis regulated HG-induced HK-2 cell dysfunction.

Conclusion

Circ_0003928 acted as a sponge for miR-506-3p to regulate HG-induced oxidative stress and apoptosis of HK-2 cells through HDAC4, which suggested that circ_0003928 might be helpful in the therapy of DN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00679-y.