Low-dose radiation-induced demethylation of 3ß-HSD participated in the regulation of testosterone content.

The effects of low-dose radiation (LDR, ≤0.1 Gy) on living organisms have been the hot areas of radiation biology but do not reach a definitive conclusion yet. So far, few studies have adequately accounted for the male reproductive system responses to LDR, particularly the regulation of testosterone content. Hence, this study was designed to evaluate the effects of LDR on Leydig cells and testicular tissue, especially the ability to synthesize testosterone. We found that less than 0.2-Gy 60 Co gamma rays did not cause significant changes in the hemogram index and the body weight; also, pathological examination did not find obvious structural alterations in testis, epididymis, and other radiation-sensitive organs. Consistently, the results from in vitro showed that only more than 0.5-Gy gamma rays could induce remarkable DNA damage, cycle arrest, and apoptosis. Notably, LDR disturbed the contents of testosterone in mice serums and culture supernatants of TM3 cells and dose dependently increased the expression of 3ß-HSD. After cotreatment with trilostane (Tril), the inhibitor of 3ß-HSD, increased testosterone could be partially reversed. Besides, DNA damage repair-related enzymes, including DNMT1, DNMT3B, and Sirt1, were increased in irradiated TM3 cells, accompanying by evident demethylation in the gene body of 3ß-HSD. In conclusion, our results strongly suggest that LDR could induce obvious perturbation in the synthesis of testosterone without causing organic damage, during which DNA demethylation modification of 3ß-HSD might play a crucial role and would be a potential target to prevent LDR-induced male reproductive damage.

Emodin-Induced Oxidative Inhibition of Mitochondrial Function Assists BiP/IRE1α/CHOP Signaling-Mediated ER-Related Apoptosis.

Cassiae Semen is a widely used herbal medicine and a popular edible variety in many dietary or health beverage. Emerging evidence disclosed that improper administration of Cassiae Semen could induce obvious liver injury, which is possibly attributed to emodin, one of the bioactive anthraquinone compounds in Cassiae Semen, which caused hepatotoxicity, but the underlying mechanisms are not completely understood. Hence, the present study firstly explored the possible role of oxidative stress-mediated mitochondrial dysfunction and ER stress in emodin-cause apoptosis of L02 cells, aiming to elaborate possible toxic mechanisms involved in emodin-induced hepatotoxicity. Our results showed that emodin-induced ROS activated ER stress and the UPR via the BiP/IRE1α/CHOP signaling pathway, followed by ER Ca2+ release and cytoplasmic Ca2+ overloading. At the same time, emodin-caused redox imbalance increased mtROS while decreased MMP and mitochondrial function, resulting in the leaks of mitochondrial-related proapoptotic factors. Interestingly, blocking Ca2+ release from ER by 2-APB could inhibit emodin-induced apoptosis of L02, but the restored mitochondrial function did not reduce the apoptosis rates of emodin-treated cells. Besides, tunicamycin (TM) and doxorubicin (DOX) were used to activate ER stress and mitochondrial injury at a dosage where obvious apoptosis was not observed, respectively. We found that cotreatment with TM and DOX significantly induced apoptosis of L02 cells. Thus, all the results indicated that emodin-induced excessive ROS generation and redox imbalance promoted apoptosis, which was mainly associated with BiP/IRE1α/CHOP signaling-mediated ER stress and would be enhanced by oxidative stress-mediated mitochondrial dysfunction. Altogether, this finding has implicated that redox imbalance-mediated ER stress could be an alternative target for the treatment of Cassiae Semen or other medicine-food homologous varieties containing emodin-induced liver injury.

Mitochondrial Iron Overload-Mediated Inhibition of Nrf2-HO-1/GPX4 Assisted ALI-Induced Nephrotoxicity.

Aristolactam I (ALI) is an active component derived from some Traditional Chinese medicines (TCMs), and also the important metabolite of aristolochic acid. Long-term administration of medicine-containing ALI was reported to be related to aristolochic acid nephropathy (AAN), which was attributed to ALI-induced nephrotoxicity. However, the toxic mechanism of action involved is still unclear. Recently, pathogenic ferroptosis mediated lipid peroxidation was demonstrated to cause kidney injury. Therefore, this study explored the role of ferroptosis induced by mitochondrial iron overload in ALI-induced nephrotoxicity, aiming to identify the possible toxic mechanism of ALI-induced chronic nephropathy. Our results showed that ALI inhibited HK-2 cell activity in a dose-dependent manner and significantly suppressed glutathione (GSH) levels, accompanying by significant increases in intracellular 4-hydroxynonenal (4-HNE) and intracellular iron ions. Moreover, the ALI-mediated cytotoxicity could be reversed by deferoxamine mesylate (DFO). Compared with other inhibitors, Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, obviously alleviated ALI-induced cytotoxicity. Furthermore, we have shown that ALI could remarkably increase the levels of superoxide anion and ferrous ions in mitochondria, and induce mitochondrial damage and condensed mitochondrial membrane density, the morphological characteristics of ferroptosis, all of which could be reversed by DFO. Interestingly, ALI dose-dependently inhibited these protein contents of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and glutathione peroxidase 4 (GPX4), which could be partly rescued by Tin-protoporphyrin IX (SnPP) and mitoTEMPO co-treatment. In conclusion, our results demonstrated that mitochondrial iron overload-mediated antioxidant system inhibition would assist ALI-induced ferroptosis in renal tubular epithelial cells, and Nrf2-HO-1/GPX4 antioxidative system could be an important intervention target to prevent medicine containing ALI-induced nephropathy.

Cryptotanshinone and wogonin up-regulate eNOS in vascular endothelial cells via ERα and down-regulate iNOS in LPS stimulated vascular smooth muscle cells via ERß.

Phytoestrogens were widely used as natural alternatives to estrogen for treating cardiovascular diseases. They have been reported to have cardioprotective and anti-inflammatory response, but the mechanisms remain unclear. In this study, we found cryptotanshinone and wogonin exhibited phytoestrogenic property in an estrogen-responsive reporter assay. In EA.hy926 cells, treatment of cryptotanshinone and wogonin led to significant increase in NO production levels, which were inhibited by co-incubation of estrogen receptor (ER)α antagonist methyl-piperidino-pyrazole (MPP). The expression of endothelial NO synthase (eNOS) and ERα were up-regulated with the same treatment, indicating they stimulate NO and eNOS expression via ERα-dependent pathway in endothelial cells. While in lipopolysaccharide activated vascular smooth muscle cell line A7r5, cryptotanshinone and wogonin exerted anti-inflammatory effects by inhibiting NO and inducible NO synthase expression via ERß-dependent pathway. The reduction of NO synthesis was not affected by MPP, and was abrogated by ERß antagonist R,R-tetrahydrochrysene. Our findings provide the potential molecular mechanism of cryptotanshinone and wogonin as phytoestrogens for their cardioprotective effects, which exerted regulatory effects on NO synthesis through differential regulation of estrogen receptors. It can be employed as a basis for evaluating the beneficial effects of phytoestrogens in the treatment of patients at risk of cardiovascular disease.

[Preliminary investigation on mechanism of Naoxintong capsule's preventive treatment of cardio-cerebrovascular disease based on serum proteomics].

Naoxintong capsule has beneficial effects for activating blood circulation, dispersing blood stasis and dredging collateral. It is widely used in the treatment of coronary heart disease, angina pectoris, stroke and cardiovascular disease. However, the pharmacodynamic basis and possible mechanism of its preventive effects are not clear. In this study, 10 male and 10 female C57BL/6 mice were used, and were randomly divided into the control group (saline) and Naoxintong group. Adaptively fed for 7 days in common conditions, mice were given Naoxintong capsule or saline for 3 days via intragastric administration. Serum was collected from 6 mice in each group 1 h after the last administration. Serum proteins were prepared to do two-dimensional gel electrophoresis. Then image analysis and mass spectrometry detection were carried out to screen and identify the differentially expressed proteins and make bioinformatics analysis. It was found that 24 differentially expressed proteins between Naoxintong group and control group. Compared with the control group, 12 proteins were increased, and 12 were decreased. The proteins were involved in apoptosis signal pathway and vascular endothelial growth factor signal transduction pathway, in which vasohibin-1 is a negative feedback regulation factor in angiogenesis. Western blot showed that the expression of vasohibin-1 in Naoxintong group was reduced, which is consistent with the result in two-dimensional electrophoresis. Serum proteins expression is different between Naoxintong and control groups. The targets of these differentially expressed proteins include endothelial cells, inflammatory cells and platelets. The changes on proteins showed that Naoxintong capsule may ameliorate coronary heart disease and ischemic cerebrovascular disease, and provide potential biological markers to prevent ischemic disease.

[Effect of Naoxintong capsule on endothelial progenitor cell mobilization and homing following bone marrow transplantation in a mouse hind limb ischemia model].

Endothelial progenitor cells (EPCs) are precursor cells of endothelial cells. Signal molecules produced by ischemia and hypoxia can promote mobilization of bone marrow EPCs to peripheral circulation and formation of novel blood vessels in tissues that are damaged during heart attack. Naoxintong capsule (NXT) has the functions of promoting blood circulation, removing blood stasis, promoting the circulation of qi and relieving pain. The various components in NXT have protective effects on blood vessels and can effectively improve the symptoms of ischemia. However, its effect on EPCs is not clear. To study the intervention effect of NXT on mobilization and homing of peripheral blood EPCs, green fluorescent protein (GFP) transgenic mice were used for bone marrow transplantation (BMT) and then unilateral hind limb ischemia model (UHLI) were constructed. For BMT, wild-type ICR mice were irradiated by CS137 and then injected with 4×106 bone marrow cells isolated from GFP mice. The bone marrow reconstitution of recipients was assessed by quantification of GFP bone marrow-derived cells (BMDC) from transplanted mice 4 weeks after BMT. The UHLI model was duplicated by ligating femoral artery and divided into three groups: the model group, the NXT group (model+NXT) and the positive control group (model+simvastatin). Flow cytometry was used to detect the proportion of GFP positive cells and the peripheral blood EPCs levels at 1, 3, 7, 14 days before and after surgery. Ischemic tissue of gastrocnemius muscle was excised at 3 and 7 days after operation for immunofluorescence staining to detect the number of GFP+ cells. The bone marrow chimerism was achieved at day 28 after BMT. There was no significant difference in the percentage of GFP positive cells between BMT mice and GFP transgenic mice. NXT and simvastatin could significantly increase the number of peripheral blood EPCs 1,3 days after surgery. Three and seven days after operation, the number of homing EPCs was significantly higher in NXT group and positive control group than that in model group (P<0.001). In conclusion, NXT can obviously promote the mobilization and homing of EPCs.