Generation and characterization of GATA6-specific EGFP expressing human induced pluripotent stem cell line, KSCBi017-A-1, using CRISPR/Cas9.

GATA6 is expressed during early embryogenesis and localizes to endoderm- and mesoderm-derived tissues during later embryogenesis. Here, we established a human induced pluripotent stem cell (hiPSC) line expressing EGFP under GATA6 gene. EGFP coding sequence was introduced into the C-terminus of GATA6 in KSCBi017-A hiPSCs through homologous recombination using CRISPR/Cas9 system. The successfully edited line, KSCBi017-A-1, was selected and confirmed by sequencing. The line had a normal karyotype and exhibited potential to differentiate into three germ layers while it expressed EGFP upon endoderm induction. KSCBi017-A-1 cells can be used to monitor the expression of GATA6 during differentiation. This cell line is available from Korea National Stem Cell Bank.

Inactivation of Pmc1 vacuolar Ca(2+) ATPase causes G(2) cell cycle delay in Hansenula polymorpha.

The vacuolar Ca(2+) ATPase Pmc1 is involved in maintenance of a low Ca(2+) concentration in cytosol in yeast cells. Here we observed that increase of Ca(2+) cytosolic concentration in yeast Hansenula polymorpha due to inactivation of Pmc1 resulted in sensitivity to sodium dodecyl sulfate (SDS). To elucidate the mechanisms of the observed effect, a screening for mutations suppressing SDS sensitivity of the H. polymorpha pmc1 mutant was performed. As a result, three genes were identified. Two of them, designated as their Saccharomyces cerevisiae orthologs CCH1 and HOG1 encoded the plasma membrane voltage-gated high-affinity calcium channel and the MAP kinase involved in osmoregulation, respectively. The third gene, designated as WEE1, coded for the ortholog of Wee1/Swe1 kinase involved in cell cycle regulation by inhibiting of the G(2)/M transition. Detailed analysis of this mutant demonstrated that suppression of pmc1 SDS sensitivity by the wee1 mutation depended on an accompanying chromosomal rearrangement, whereas inactivation of WEE1 in the absence of this rearrangement caused SDS sensitivity. Expression of a chimeric protein containing an N-terminal portion of Wee1 in the pmc1 mutant led to abnormal morphology characteristic of G(2) delay. Our data indicate that cytosolic Ca(2+) rise causes SDS sensitivity in H. polymorpha through the activation of the Wee1 kinase, which is mediated by the Hog1 kinase. Wee1 has a dual role in the manifestation of SDS sensitivity in the H. polymorpha pmc1 mutant. Mechanisms of influence of the obtained mutations on the G(2)/M transition are discussed.

Norbornadiene End-Capping of Cross-Coupling Polymerizations: A Facile Route to Triblock Polymers.

The potential use of conjugated polymers in device applications is often limited by their less than optimal physicochemical properties. This work describes an efficient protocol to end-cap conjugated polymers synthesized via palladium-catalyzed cross-coupling polymerizations with norbornene groups. Specifically, the hydroarylation of norbornadiene is shown to be a high-yielding end-capping method. These strained bicyclic alkenyl end groups can be transformed into macroinitiators via ring-opening metathesis polymerization and can polymerize other strained monomers, such as norbornene, yielding elastomeric triblock copolymers.

Damage and recovery of skin barrier function after glycolic acid chemical peeling and crystal microdermabrasion.

BACKGROUND: Superficial chemical peeling and microdermabrasion have become increasingly popular methods for producing facial rejuvenation. However, there are few studies reporting the skin barrier function changes after these procedures. OBJECTIVE: To evaluate objectively the degree of damage visually and the time needed for the skin barrier function to recover after glycolic acid peeling and aluminum oxide crystal microdermabrasion using noninvasive bioengineering methods. METHODS: Superficial chemical peeling using 30%, 50%, and 70% glycolic acid and aluminum oxide crystal microdermabrasion were used on the volar forearm of 13 healthy women. The skin response was measured by a visual observation and using an evaporimeter, corneometer, and colorimeter before and after peeling at set time intervals. RESULTS: Both glycolic acid peeling and aluminum oxide crystal microdermabrasion induced significant damage to the skin barrier function immediately after the procedure, and the degree of damage was less severe after the aluminum oxide crystal microdermabrasion compared with glycolic acid peeling. The damaged skin barrier function had recovered within 24 hours after both procedures. The degree of erythema induction was less severe after the aluminum oxide crystal microdermabrasion compared with the glycolic acid peeling procedure. The degree of erythema induced after the glycolic acid peeling procedure was not proportional to the peeling solution concentration used. The erythema subsided within 1 day after the aluminum oxide crystal microdermabrasion procedure and within 4 days after the glycolic acid peeling procedure. CONCLUSION: These results suggest that the skin barrier function is damaged after the glycolic acid peeling and aluminum oxide crystal microdermabrasion procedure but recovers within 1 to 4 days. Therefore, repeating the superficial peeling procedure at 2-week intervals will allow sufficient time for the damaged skin to recover its barrier function.