Evaluating the effect of spaceflight on the host-pathogen interaction between human intestinal epithelial cells and Salmonella Typhimurium.

Spaceflight uniquely alters the physiology of both human cells and microbial pathogens, stimulating cellular and molecular changes directly relevant to infectious disease. However, the influence of this environment on host-pathogen interactions remains poorly understood. Here we report our results from the STL-IMMUNE study flown aboard Space Shuttle mission STS-131, which investigated multi-omic responses (transcriptomic, proteomic) of human intestinal epithelial cells to infection with Salmonella Typhimurium when both host and pathogen were simultaneously exposed to spaceflight. To our knowledge, this was the first in-flight infection and dual RNA-seq analysis using human cells.

Characteristic Cytological Findings of Lobular Endocervical Glandular Hyperplasia Associated with Adenocarcinoma of the Uterine Cervix.

OBJECTIVE: To investigate the cytological findings of lobular endocervical glandular hyperplasia (LEGH) associated with adenocarcinoma and to clarify its characteristics and the coexisting adenocarcinoma using histochemistry and immunohistochemistry. METHODS: Eighteen surgical cases of LEGH of the uterine cervix were retrospectively reviewed and classified into 3 groups: pure (pure type), atypical (atypical type), and LEGH with adenocarcinoma (mixed type). The mixed type is defined as LEGH or atypical LEGH with in situ or invasive adenocarcinoma. Cytological findings of conventional endocervical smear specimens (Papanicolaou stain) were analyzed. Histochemistry (periodic acid-Schiff reaction) and immunohistochemistry (M-GGMC-1, Muc-6 glycoprotein, and Ki-67) were performed using tissue specimens. RESULTS: Cytologically, the pure type (7 cases) is characterized by glandular cell clusters that tended to form monolayered sheets with uniformly small nuclei and contain golden-yellowish mucin, whereas atypical (5 cases) and mixed (6 cases) types are characterized by glandular cell clusters similar to those of the pure type, but with complex glandular structures and mucin localization on the surface of glandular cell clusters. Ki-67 labeling index was significantly higher in atypical and mixed types than that in the pure type. Gastric-type mucinous carcinoma (MC-G) was observed in 2 out of 6 cases with mixed type. CONCLUSIONS: LEGH is found to be associated with adenocarcinoma types other than MC-G. Complex glandular structures or mucin localization on the surface of glandular cell clusters may be useful cytological findings to detect atypical and mixed types of LEGH.

Carboxylated phytosterol derivative-introduced liposomes for skin environment-responsive transdermal drug delivery system.

Transdermal drug delivery systems are a key technology for skin-related diseases and for cosmetics development. The delivery of active ingredients to an appropriate site or target cells can greatly improve the efficacy of medical and cosmetic agents. For this study, liposome-based transdermal delivery systems were developed using pH-responsive phytosterol derivatives as liposome components. Succinylated phytosterol (Suc-PS) and 2-carboxy-cyclohexane-1-carboxylated phytosterol (CHex-PS) were synthesized by esterification of hydroxy groups of phytosterol. Modification of phytosterol derivatives on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes was confirmed by negatively zeta potentials at alkaline pH and the change of zeta potentials with decreasing pH. In response to acidic pH and temperatures higher than body temperature, Suc-PS-containing and CHex-PS-containing liposomes exhibited content release at intracellular acidic compartments of the melanocytes at the basement membrane of the skin. Phytosterol-derivative-containing liposomes were taken up by murine melanoma-derived B16-F10 cells. These liposomes delivered their contents into endosomes and cytosol of B16-F10 cells. Furthermore, phytosterol-derivative-containing liposomes penetrated the 3 D skin models and reached the basement membrane. Results show that pH-responsive phytosterol-derivative-containing DMPC liposomes are promising for use in transdermal medical or cosmetic agent delivery to melanocytes.

Preparation of dual-stimuli-responsive liposomes using methacrylate-based copolymers with pH and temperature sensitivities for precisely controlled release.

Dual-signal-sensitive copolymers were synthesized by copolymerization of methoxy diethylene glycol methacrylate, methacrylic acid, and lauroxy tetraethylene glycol methacrylate, which respectively provide temperature sensitivity, pH sensitivity, and anchoring to liposome surfaces. These novel copolymers, with water solubility that differs depending on temperature and pH, are soluble in water under neutral pH and low-temperature conditions, but they become water-insoluble and form aggregates under acidic pH and high-temperature conditions. Liposomes modified with these copolymers exhibited enhanced content release at weakly acidic pH with increasing temperature, although no temperature-dependent content release was observed in neutral conditions. Interaction between the copolymers and the lipid monolayer at the air-water interface revealed that the copolymer chains penetrate more deeply into the monolayer with increasing temperature at acidic pH than at neutral pH, where the penetration of copolymer chains was moderate and temperature-independent at neutral pH. Interaction of the copolymer-modified liposomes with HeLa cells demonstrated that the copolymer-modified liposomes were adsorbed quickly and efficiently onto the cell surface and that they were internalized more gradually than the unmodified liposomes through endocytosis. Furthermore, the copolymer-modified liposomes enhanced the content release in endosomes with increasing temperature, but no such temperature-dependent enhancement of content release was observed for unmodified liposomes.

Regulation of leaf organ size by the Arabidopsis RPT2a 19S proteasome subunit.

The ubiquitin/26S proteasome pathway plays a central role in the degradation of short-lived regulatory proteins, to control many cellular events. To further understand this pathway, we focused on the RPT2 subunit of the 26S proteasome regulatory particle. The Arabidopsis genome contains two genes, AtRPT2a and AtRPT2b, which encode paralog molecules of the RPT2 subunit, with a difference of only three amino acids in the protein sequences. Both genes showed similar mRNA accumulation patterns. However, the rpt2a mutant showed a specific phenotype of enlarged leaves caused by increased cell size, in correlation with increased ploidy. Detailed analyses revealed that cell expansion is increased in the rpt2a mutant by extended endoreduplication early in leaf development. The transcription of genes encoding cell cycle-related components, for DNA replication licensing and the G2/M phase, was also promoted in the rpt2a mutant, suggesting that extended endoreduplication was caused by increased DNA replication, and disrupted regulation of the G2/M checkpoint, at the proliferation stage of leaf development.