Protective Functions of Group 3 Late Embryogenesis Abundant (G3LEA) Proteins in Enterococcus faecium During Vancomycin Treatment.

Late embryogenesis abundant (LEA) proteins protect organisms from various environmental stresses; however, the underlying mechanism of LEA mediated therapeutic evasion is still unclear in both eukaryotes and prokaryotes. In this study, group 3 LEA protein (G3LEA) of vancomycin-resistant Enterococcus faecium under sublethal concentration of vancomycin stress was evaluated and shown to have two functions: the first is the reduction of reactive oxygen species (ROS) content, preventing apoptosis by suppressing apoptotic proteins Cas3 and MAOB, and the second is activating specific drug efflux pumps. Sublethal vancomycin model was established with using Propidium Iodide (PI) stain. Real-time PCR was conducted to evaluate the expression of G3lea. Flow cytometry and confocal microscope using Anti- G3LEA, anti- MAOB, and anti- Cas3 were performed to assess the expression of G3LEA. Under sublethal vancomycin stress, G3LEA is upregulated, suppressing the expression of apoptotic markers and increasing specific efflux markers. These results suggest that G3LEA protein suppresses antibiotic mediated apoptosis in prokaryotic cells and plays a key role in understanding and preventing antibiotic resistance.

Bioactivity of Fermented Green Coffee Bean Extract Containing High Chlorogenic Acid and Surfactin.

Chlorogenic acid (CGA) is a major component of green coffee beans. Surfactin, a cyclic lipopeptide, is produced and secreted by Bacillus subtilis strains. In this study, bioactivities of fermented green coffee bean extract (FGCBE) and the individual compounds, CGA and surfactin. were compared in HepG2 cells. The concentration of surfactin and CGA in the FGCBE and non-fermented green coffee bean extract (NFGCBE) were determined to be 9.2 and 7.33 and 0.72 and 0.53 mg·mL-1, respectively. The FGCBE contained about 20% and 26% more CGA and surfactin than the NFGCBE. Although CGA and surfactin exhibited cytotoxicity at concentrations more than 100 and 20 µg respectively, the FGCBE 50 containing CGA (460 µg·mL-1) and surfactin (720 µg·mL-1) effectively prevented cell death by oxidative stress and also strongly activated the proliferation of cells incubated with under 50 µM H2O2. The CGA and surfactin in FGCBE were 9.2 and 72 times higher than the CGA and surfactin compounds (50 and 10 µg·mL-1). The relative proliferation of the FGCBE-treated cells also was 3.3 and 8.8 times higher than the CGA and surfactin compounds treated the oxidative stressed cells with 50 µM H2O2. These results suggest that the single compounds such as CGA and surfactin generally have cytotoxicity at low concentration of them but FGCBE contained them acted as strong antioxidants, activators of cell proliferation, inhibitors of cell apoptosis. Various bioactive compounds in fermented coffee bean also seem to help cell proliferation and decreasing of cytotoxicity by CGA and surfactin in coffee bean.

The Different Expression Patterns of HSP22, a Late Embryogenesis Abundant-like Protein, in Hypertrophic H9C2 Cells Induced by NaCl and Angiotensin II.

BACKGROUND: High-NaCl diet is a contributing factor for cardiac hypertrophy. The role of HSP22 as a protective protein during cardiac hypertrophy due to hypernatremia is unclear. Accordingly, this study aimed to establish a cellular hypernatremic H9C2 model and to compare the expression of HSP22 in Ca2+ homeostasis between a high-NaCl and angiotensin II-induced hypertrophic cellular H9C2 model. METHODS: Real-time PCR was performed to compare the mRNA expression. Flow cytometry and confocal microscopy were used to analyze the cells. RESULTS: The addition of 30 mM NaCl for 48 h was the most effective condition for the induction of hypertrophic H9C2 cells (termed the in vitro hypernatremic model). Cardiac cellular hypertrophy was induced with 30 mM NaCl and 1 µM angiotensin II for 48 h, without causing abnormal morphological changes or cytotoxicity of the culture conditions. HSP22 contains a similar domain to that found in the consensus sequences of the late embryogenesis abundant protein group 3 from Artemia. The expression of HSP22 gradually decreased in the in vitro hypernatremic model. In contrast to the in vitro hypernatremic model, HSP22 increased after exposure to angiotensin II for 48 h. Intracellular Ca2+ decreased in the angiotensin II model and further decreased in the in vitro hypernatremic model. Impaired intracellular Ca2+ homeostasis was more evident in the in vitro hypernatremic model. CONCLUSION: The results showed that NaCl significantly decreased HSP22. Decreased HSP22, due to the hypernatremic condition, affected the Ca2+ homeostasis in the H9C2 cells. Therefore, hypernatremia induces cellular hypertrophy via impaired Ca2+ homeostasis. The additional mechanisms of HSP22 need to be explored further.

A bioorthogonal 'turn-on' fluorescent probe for tracking mitochondrial nitroxyl formation.

A bioreductant-resistant 'turn-on' chemodosimetric fluorescent probe Mito-1 has been developed for the detection of mitochondrial HNO in live cells. Mito-1 enables the detection of HNO as low as ∼18 nM. It has the capability to detect both exogenous and endogenous mitochondrial HNO formations in cellular milieus by providing fluorescence images. Its two-photon imaging ability fosters its use as a noninvasive imaging tool for the detection of mitochondrial nitroxyl.

Genetic testing of Korean familial hypercholesterolemia using whole-exome sequencing.

Familial hypercholesterolemia (FH) is a genetic disorder with an increased risk of early-onset coronary artery disease. Although some clinically diagnosed FH cases are caused by mutations in LDLR, APOB, or PCSK9, mutation detection rates and profiles can vary across ethnic groups. In this study, we aimed to provide insight into the spectrum of FH-causing mutations in Koreans. Among 136 patients referred for FH, 69 who met Simon Broome criteria with definite family history were enrolled. By whole-exome sequencing (WES) analysis, we confirmed that the 3 known FH-related genes accounted for genetic causes in 23 patients (33.3%). A substantial portion of the mutations (19 of 23 patients, 82.6%) resulted from 17 mutations and 2 copy number deletions in LDLR gene. Two mutations each in the APOB and PCSK9 genes were verified. Of these anomalies, two frameshift deletions in LDLR and one mutation in PCSK9 were identified as novel causative mutations. In particular, one novel mutation and copy number deletion were validated by co-segregation in their relatives. This study confirmed the utility of genetic diagnosis of FH through WES.