l-asparaginase production and enhancement by Sarocladium strictum: In vitro evaluation of anti-cancerous properties.

AIMS: Utilization of l-asparaginase has been one of the effective strategies for the treatment of lymphoblastic leukaemia. Since the currently used bacterial l-asparaginase causes side effects, searching for new enzyme sources has been an active field of research. This study focuses on the characterization of an l-asparaginase-producing fungal strain. METHODS AND RESULTS: Sarocladium strictum was identified as a potent enzyme-producing strain. For the enhancement of enzyme production, we used two-level factorial design and response surface methodology. The optimization of significant factors showed a 1·84-fold increase in enzyme production. The Km and Vmax values of the enzyme were 9·74 mmol l-1 and 8·19 µmol min-1 . The toxicity of the produced l-asparaginase was measured on K562 and HL60 cancer cell lines and L6 as normal cells. The IC50 values were calculated as 0·4 and 0·5 IU ml-1 for K562 and HL60 respectively and no significant effect was observed in L6. BrdU proliferation and caspase-3 activity assay in l-asparaginase treated HL60 and K562 cells indicated that cell proliferation rates and apoptotic cell death were reduced. CONCLUSIONS: The cytotoxic properties of the produced fungal enzyme indicated significant growth inhibition in cancer cells while having a little toxic effect on normal cells. The possibility of mass production alongside having suitable cytotoxic and kinetic properties suggest the probable use of the produced l-asparaginase for further researches as a potential chemotherapeutic agent. SIGNIFICANCE AND IMPACT OF THE STUDY: The lack of significant l-glutaminase activity and promising toxicity properties in S. strictum and the closer evolutionary relativeness of fungi enzymes to human enzymes compared to bacterial enzymes suggest a new source with lower toxicity and anti-cancerous properties, causing less side effect problems.

The effect of salt supplements on thyroid hormones and quality of pregnancy in female hypothyroid rats.

BACKGROUND: The use of nutrient supplements along with medication to optimize the treatment of diseases yields desirable outcomes. Hypothyroidism causes abnormalities in cells, and organs, and induces gene expression changes. The use of salt supplements and vitamins considerably helps to treat hypothyroidism. OBJECTIVES: To evaluate the effect of a food supplement containing iron, iodine, and folic acid on thyroid hormones changes as well as the quality and quantity of hypothyroid female rat's offspring. MATERIALS AND METHODS: In the current experimental study, 40 female rats were divided into six experimental and two control groups. The study was conducted in three phases. In the first phase, the role of a combinatory supplement along with levothyroxine to treat hypothyroidism by assessing T3, T4, and TSH hormones was investigated. In the second phase, the dose-depended effects of a combinatory supplement were investigated. Additionally, in the third phase, the quality and quantity of the next generation were measured in the hypothyroid female rats receiving the salt supplement. RESULTS: The plasma level of T3, T4 and TSH in hypothyroid rats receiving nutrient supplements indicated that the use of combinatory supplements along with levothyroxine could have desirable effects on the treatment of hypothyroidism to such an extent that the level of T3 and T4 hormones in the intervention group was significantly higher than that of the control group (P≤0.01). The second phase demonstrated that the desired effects of combinatory supplements on the serum levels of T3, T4, and TSH hormones were dose-dependent so that by increasing the dosage of supplementation, a significant decrease in the TSH level was observed (P <0.05), while T3 and T4 levels increased (P <0.01).The results of the third phase demonstrated that salt supplements could be effective in reducing the number of dead or preterm pups, and the use of mineral salts along with levothyroxine could promote a healthy birth. CONCLUSION: Salt supplements have considerable effects on the health status of the offspring of hypothyroid rats, resulting in the birth of more healthy pups and reducing the rate of abortion or preterm births.

Cortactin, an actin binding protein, regulates GLUT4 translocation via actin filament remodeling.

Insulin regulates glucose uptake into fat and skeletal muscle cells by modulating the translocation of GLUT4 between the cell surface and interior. We investigated a role for cortactin, a cortical actin binding protein, in the actin filament organization and translocation of GLUT4 in Chinese hamster ovary (CHO-GLUT4myc) and L6-GLUT4myc myotube cells. Overexpression of wild-type cortactin enhanced insulin-stimulated GLUT4myc translocation but did not alter actin fiber formation. Conversely, cortactin mutants lacking the Src homology 3 (SH3) domain inhibited insulin-stimulated formation of actin stress fibers and GLUT4 translocation similar to the actin depolymerizing agent cytochalasin D. Wortmannin, genistein, and a PP1 analog completely blocked insulin-induced Akt phosphorylation, formation of actin stress fibers, and GLUT4 translocation indicating the involvement of both PI3-K/Akt and the Src family of kinases. The effect of these inhibitors was even more pronounced in the presence of overexpressed cortactin suggesting that the same pathways are involved. Knockdown of cortactin by siRNA did not inhibit insulin-induced Akt phosphorylation but completely inhibited actin stress fiber formation and glucose uptake. These results suggest that the actin binding protein cortactin is required for actin stress fiber formation in muscle cells and that this process is absolutely required for translocation of GLUT4-containing vesicles to the plasma membrane.