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Background: Lymphocytes are a group of white blood cells with a variety of roles their integrity is crucial for the body's immune responses. Cadmium, a heavy metal and environmental pollutant, is known as a toxicant to exert its adverse effects on some sort of cells including blood cells. Research Design: In this study, human lymphocytes were divided into 3 groups: (1) lymphocytes at 0-h, (2) lymphocytes at 24 h (control), (3) lymphocytes treated with cadmium chloride (15 μM). Lymphocyte viability and plasma membrane integrity were assessed in these groups. In addition, the occurrence of apoptosis was investigated by assessment of nucleus diameter and flow cytometry. Activation of caspase-3 was also detected by immunocytochemistry. Results: Result showed that lymphocyte's viability and plasma membrane integrity decreased in lymphocytes treated with cadmium as compared with the control group. Decreased nucleus diameter and result of flow cytometry demonstrated cadmium-induced apoptosis in human lymphocytes. Furthermore, lymphocytes treated with cadmium displayed intensely activated caspase-3 immunoreactivity in their cytoplasm. Conclusion: In conclusion, cadmium not only negatively effect on viability and plasma membrane, but also induces caspase-dependent apoptosis in human lymphocytes. [ABSTRACT FROM AUTHOR]

Oxidative stress‐induced apoptosis in spermatozoa may lead to male infertility. Environmental pollutants and heavy metals such as cadmium cause harmful effects on the reproductive system and sperm parameters through the induction of oxidative stress. Silymarin, as a potent antioxidant, is able to inhibit oxidative stress. This study was performed to investigate the protective effects of silymarin on cadmium‐induced toxicity in human spermatozoa. Sperm samples were divided into the following five groups: (a) spermatozoa at 0 min, (b) spermatozoa in the control group, (c) spermatozoa treated with cadmium chloride (20 μM), (d) spermatozoa treated with silymarin (2 μM)+ cadmium chloride (20 μM) and (e) spermatozoa treated with silymarin (2 μM). Sperm parameters related to apoptosis, such as DNA fragmentation, nucleus diameter, mitochondrial membrane potential (MMP) and expression of caspase‐3, were evaluated in all groups. After 180 min, spermatozoa treated with cadmium chloride showed a significant decrease in nucleus diameter and MMP but a significant increase in DNA fragmentation; however, caspase‐3 expression remained unchanged. At this time point, silymarin in the silymarin + cadmium chloride group could significantly reverse the adverse effects of cadmium chloride on these parameters.Silymarn could partly compensate for the caspase‐independent apoptosis in the spermatozoa. Therefore, oxidative stress could be a consequence for cadmium toxicity. [ABSTRACT FROM AUTHOR]

• Maturation and function of microRNAs(miRNAs), besides their association with p53. • The roles of p53 and some miRNAs in cellular response to stress. • Regulation of the cell cycle checkpoints, proliferation, tumor suppression and reprogramming by p53 induced miRNAs. • Regulation of p53 induced miRNAs involving in apoptosis. • Correlation between P53 and neurodegenerative disorders such as Parkinson's and Alzheimer's diseases. MicroRNAs (miRNAs) are endogenous and small non-coding RNAs that have been identified as mediators of tumor suppression as well as stress responses mediated by p53 suppressors. MiRNAs may act as tumor suppressors under certain conditions. MiRNAs regulated by p53 may control the expression of processes such as cell cycle progression, cell survival, and angiogenesis. P53 activity and expression are also controlled by miRNA; consequently alterations in the p53-miRNA network may be essential for tumor initiation and progression. Future studies on the p53-miRNA network presumably would find it helpful in diagnostic and therapeutic approaches or as tools for various cancers. [ABSTRACT FROM AUTHOR]