Modulatory effect of selenium on cell-cycle regulatory genes in the prostate adenocarcinoma cell line

Assessing the effect of selenium on cyclin D1 level and nuclear factor kappa b activity in NIH/3T3 fibroblast cells at 2100 MHz electromagnetic field exposure

Although there are numerous studies on the health impacts of electromagnetic field (EMF) of mobile phone operation frequency 2100 MHz, the published works present contradicting results. Long-term exposure to mobile phone frequencies has unclear health hazards. Therefore, it is important to investigate the molecular mechanism of possible biological effects in mobile phone exposure and to determine the corresponding biological markers. Towards this end, this study was designed to assess the effect of 200 nM selenium (Se) on cell viability% [trypan blue], cell cycle biomarker [cyclin D1] and the transcription factor [nuclear factor kappa b (NF-κB)] in NIH/3T3 fibroblast cells when exposed to 2100 MHz mobile phone frequency. When 2100 MHz EMF was exposed to NIH/3T3 fibroblast cells, the cell viability% was reduced, whereas cyclin D1 level and NF-kB activity increased. Also we show that Se supplementation decreases the effects of 2100 MHz EMF on these parameters. Although future studies will be required to investigate the biological effects of EMF emitted by mobile phones, the results obtained here provide an insight into the molecular mechanisms and specifically underlying selenium's protective effect against 2100 MHz EMF exposure.

ALDH1A1 Inhibits Chicken Preadipocytes' Proliferation and Differentiation via the PPARγ Pathway In Vitro and In Vivo

ALDH1A1 (aldehyde dehydrogenase 1A1) is a crucial protein in retinoids’ metabolism, and the lack of ALDH1A1 inhibits the fat deposition in mice. However, whether ALDH1A1 has a similar effect on chickens’ fat-depot is still unknown. In this study, we investigate the role of ALDH1A1 in chickens’ adipogenesis. The immortalized chicken preadipocyte 1 (ICP1) cell line and chicken primary preadipocytes isolated from abdominal fat were used to perform a series of experiments in vitro to elucidate the effects of ALDH1A1. In addition, lentivirus was used to verify the results of cell experiments in vivo. The data showed that overexpression of ALDH1A1 significantly weakened the proliferation of preadipocytes and suppressed the differentiation of preadipocytes through the PPARγ pathway, and the knockdown experiments had the opposite results. Moreover, chickens injected with overexpression lentivirus had higher abdominal fat percentage, a bigger size of lipid droplets, and higher triglyceride content in abdominal fat, and chickens injected with interfering lentivirus had the opposite situation. We proved that ALDH1A1 not only inhibited the proliferation and differentiation of chickens’ preadipocytes in vitro, but also inhibited the fat-depot of chickens in vivo, which was completely opposite the function of ALDH1A1 in mice, indicating that ALDH1A1 may have a different mechanism that is still unknown.

The Molecular Mechanisms of Protective Role of Se on the G0/G1 Phase Arrest Caused by AFB1 in Broiler's Thymocytes

This research was designed to explore the protective effects of sodium selenite on G₀/G₁ phase arrest induced by AFB₁ in thymocytes of broilers. Two hundred eighty-eight Cobb broilers were divided into control group, + Se group (0.4 mg/kg Se), AFB₁ group (0.6 mg/kg AFB₁), and AFB₁ + Se group (0.6 mg/kg AFB₁ + 0.4 mg/kg Se). The results revealed that 0.4 mg/kg Se supplement in diets could improve the AFB₁-induced histological lesions in the thymus consisting of the more vacuoles and nuclear debris in thymic cortical area. The results of flow cytometric detect showed that 0.4 mg/kg Se relieved the G₀/G₁ phase arrest caused by AFB₁ in thymocytes. The results of transcription levels of ATM, p53, p21, p27, p15, p16, CyclinD₁, CyclinE, Cdk6, Cdk2, and PCNA genes by qRT-PC, and protein expression level of PCNA by immunohistochemistry demonstrated that 0.4 mg/kg Se could reduce the adverse effects of AFB₁ on these parameters. In conclusion, Se could relieve AFB₁-induced G₀/G₁ phase arrest by p15 (or p16)-CyclinD₁/Cdk6, ATM-p53-p21-CyclinE/Cdk2, p27-CyclinE/Cdk2 pathways.

Interaction between angiotensin II and relaxin 2 in the progress of growth and spread of prostate cancer cells

Deregulation of locally secreted hormones, such as angiotensin II (Ang II) and relaxin 2 (RLN2), has been linked to a higher risk of select cancers or a poor prognosis in patients. In this study, for the first time a common effect of Ang II and RLN2 in relation to various aspects of prostate cancer development and metastasis are presented. Four independent colorimetric assays were used to analyze cell viability and proliferation. The changes of cell adhesion to extracellular matrix proteins and invasion/aggressiveness ability of prostate cancer cells (LNCaP, PC3) before and after peptides treatment, were also investigated. The findings suggest that the both investigated systems, have an impact on cell growth/division or spread, to some degree via overlapping signal transduction pathways. Intermediate or sometimes poorer results were achieved by using a combination of both hormones than when each was used individually. It seems that Ang II and RLN2 can play a significant role in increasing the aggressiveness of prostate tumors by up-regulating BIRC5 expression and MMP-2 and MMP-9 secretion. In addition, we speculate that Ang II and RLN2 are involved in the transition from the androgen-dependent to the androgen-independent phenotype via modulation of the expression of androgen receptors.

The role of selenium in insulin-like growth factor I receptor (IGF-IR) expression and regulation of apoptosis in mouse osteoblasts

Selenium (Se) is an essential component for animals and human beings. The chemoprotective role of Se, via the regulation of the cell cycle, stimulation of apoptosis and activation of some cytokines among others, is well known; however, the comprehensive effects of Se on the expression of IGF-IR and its regulation of apoptosis have not been investigated. Thus the aim of this study was to report on the effects that different concentrations of Se extert on body weight, blood serum IGF-IR levels and histopathology in mice; and on IGF-IR expression, proliferation and apoptosis in mouse osteoblasts. In vivo experiments showed a significant decrease in body weight, serum levels of IGF-IR and prominent toxicant effects on the liver, kidney, heart and spleen following the administration of defined concentrations of Se for 30 d. However, moderate levels (0.1 mg/kg) of Se gradually improved weight and serum IGF-IR. In vitro osteoblast experiments revealed that at concentrations of 5 × 10(-6) and 10(-5) mol/L Se, MTT activity decreased in comparison with control cells. Cell cycle, TEM and caspase-3 activity supported these observations including an increase in the sub-G1 phase and notable apoptosis in osteoblasts, along with a decrease in the expression of mRNA and protein levels of IGF-IR. Moreover, the MTT activity, mRNA and protein levels of IGF-IR in osteoblasts were decreased and caspase-3 activity was increased in siRNA groups as compared with non-siRNA groups. These data suggest that Se significantly affects IGF-IR expression, and that it contributes to the proliferation and regulation of apoptosis in osteoblasts.

Effects of dietary selenium on apoptosis of germ cells in the testis during spermatogenesis in roosters

The aim of this study was to determine the effects of dietary selenium (Se) supplementation on apoptosis of germ cells in the testis during spermatogenesis in roosters. Eighty 12-week-old Hy-Line Variety white roosters with an averaged body weight of 1.38 ± 0.2 kg were selected and randomly divided into four experimental groups. They were fed the basal diet (0.044 mg/kg Se dry matter) supplemented with 0 (control), 0.5, 1.0, or 2.0 mg/kg of Se dry matter (from sodium selenite). After the 45-day feeding experiment, testis samples were collected from the roosters of each treatment group to detect the population of apoptotic germ cells using the terminal deoxynucleotidy1 transferase dUTP nick end labeling assay. The protein expression of cell cycle-related genes and the messenger RNA (mRNA) expression of apoptosis and cell cycle-related genes had also been detected. The results show that the population of apoptotic germ cells in the control and 2.0 mg/kg groups was increased (P < 0.05) compared with that in the 0.5 mg/kg and 1.0 mg/kg groups. Expressions of CDC2 and CCNB1 protein in the control and 2.0 mg/kg groups were lower (P < 0.05) than those in the 0.5 mg/kg and 1.0 mg/kg groups. The mRNA level of CDC2 in the 0.5 mg/kg group was higher (P < 0.05) than that in other groups. The lowest (P < 0.05) mRNA expressions of apoptosis-related genes (BCL-2, CASPASE 3, CASPASE 8) were also obtained in the 0.5 mg/kg group. These results show that dietary Se of roosters can affect apoptosis of germ cells by regulating the mRNA expressions of apoptosis- and cell cycle-related genes in the testis during spermatogenesis.