The Protective Role of Hyaluronic Acid in Cr(VI)-Induced Oxidative Damage in Corneal Epithelial Cells

Cr(VI) exposure could produce kinds of intermediates and reactive oxygen species, both of which were related to DNA damage. Hyaluronan (HA) has impressive biological functions and was reported to protect corneal epithelial cells against oxidative damage induced by ultraviolet B, benzalkonium chloride, and sodium lauryl sulfate. So the aim of our study was to investigate HA protection on human corneal epithelial (HCE) cells against Cr(VI)-induced toxic effects. The HCE cell lines were exposed to different concentrations of K2Cr2O7 (1.875, 3.75, 7.5, 15.0, and 30 μM) or a combination of K2Cr2O7 and 0.2% HA and incubated with different times (15 min, 30 min, and 60 min). Our data showed that Cr(VI) exposure could cause decreased cell viability, increased DNA damage, and ROS generation to the HCE cell lines. But incubation of HA increased HCE cell survival rates and decreased DNA damage and ROS generation induced by Cr(VI) in a dose- and time-dependent manner. We report for the first time that HA can protect HCE cells against the toxicity of Cr(VI), indicating that it will be a promising therapeutic agent to corneal injuries caused by Cr(VI)

Calorimetric determination of fragility in glass forming liquids: T

The calorimetric determination of the fragility m-index is compared using the T f and T g-onset methods for typical metallic and molecular glass forming systems of Pd39Ni10Cu30P21, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T f method produces less uncertainty

Expression of chemical modification enzymes PADs and PRMTs targeting protein arginine residues in human hepatocellular carcinoma cell lines

Objective To explore the expression of protein arginine deiminases (PADs) and protein arginine methyltransferases (PRMTs) in hepatocellular carcinoma, and to analyze whether the level of protein citrullination catalyzed by PADs is related to the expression of PRMTs. Methods The mRNA transcription of PADs and PRMTs in hepatoma cells was detected by quantitative PCR and the protein expression of PADs, citrullinated proteins and PRMTs was detected by Western blot. The mRNA correlation between PADs and PRMTs in liver cancer tissues in TCGA database was analyzed by bioinformatics, and the expressions of PADs, citrullinated proteins and PRMTs in liver cancer tissues was detected by immunohistochemistry. Results Compared with normal liver cell LX-2, the mRNA transcription of PAD2 and PRMT1 in Huh7 cells was higher (P＜0.001), and that of PAD4, PRMT1, PRMT5 and PRMT7 in HepG2 cells was higher (P＜0.01). The protein level of PAD2 and PAD4 in HepG2 and Huh7 was significantly higher than those in LX-2 (P＜0.01). The expression level of citrullinated protein in HepG2 and Huh7 was lower than that in LX-2. The expression of PADs and PRMTs in hepatocellular carcinoma was stronger than that in adjacent tissues, and the expression of citrullinated proteins was almost negative. There were positive correlation between PAD2 and all PRMTs in clinical sample database (P＜0.05). Conclusions The expression of PADs is high in hepatocellular carcinoma, whereas the expression of citrullinated proteins is low, which may be affected by the competition of PRMTs enzyme highly expressed in cells