Modulation of Mammalian Cell Behavior by Nanoporous Glass.

The introduction of novel bioactive materials to manipulate living cell behavior is a crucial topic for biomedical research and tissue engineering. Biomaterials or surface patterns that boost specific cell functions can enable innovative new products in cell culture and diagnostics. This study investigates the influence of the intrinsically nano-patterned surface of nanoporous glass membranes on the behavior of mammalian cells. Three different cell lines and primary human mesenchymal stem cells (hMSCs) proliferate readily on nanoporous glass membranes with mean pore sizes between 10 and 124 nm. In both proliferation and mRNA expression experiments, L929 fibroblasts show a distinct trend toward mean pore sizes >80 nm. For primary hMSCs, excellent proliferation is observed on all nanoporous surfaces. hMSCs on samples with 17 nm pore size display increased expression of COL10, COL2A1, and SOX9, especially during the first two weeks of culture. In the upside down culture, SK-MEL-28 cells on nanoporous glass resist the gravitational force and proliferate well in contrast to cells on flat references. The effect of paclitaxel treatment of MDA-MB-321 breast cancer cells is already visible after 48 h on nanoporous membranes and strongly pronounced in comparison to reference samples, underlining the material's potential for functional drug screening.

Inhibitors of macrophage infectivity potentiator-like PPIases affect neisserial and chlamydial pathogenicity.

The pathogenic bacteria Chlamydia trachomatis, Neisseria gonorrhoeae and Neisseria meningitidis express the surface-exposed macrophage infectivity potentiator (MIP)-like protein, which plays a role in their pathogenicity. MIP exhibits a peptidyl-prolyl isomerase (PPIase) activity that is inhibited by rapamycin and FK506. In this study, pipecolic acid derivatives were tested for their activity against the chlamydial and neisserial MIP. Two MIP inhibitors were identified, PipN3 and PipN4, that affected the developmental cycle of C. trachomatis in HeLa cells. Furthermore, we could show that deletion of neisserial MIP or addition of the two MIP inhibitors affected the survival of N. gonorrhoeae in the presence of neutrophils. Furthermore, both compounds inhibited the adherence, invasion and/or survival of N. meningitidis in epithelial cells. These results confirm the importance of MIP-like proteins in infection and indicate the relevance of pipecolic acid derivatives as antimicrobials against C. trachomatis, N. gonorrhoeae and N. meningitidis.

Colocalization but differential regulation of neuronal NO synthase and nicotinic acetylcholine receptor in C2C12 myotubes.

In mammalian skeletal muscle, neuronal-type nitric oxide synthase (nNOS) is found to be enriched at neuromuscular endplates. Here we demonstrate the colocalization of the nicotinic acetylcholine receptor (nAChR, stained with alpha-bungarotoxin) and nNOS (stained with a specific antibody) in murine C(2)C(12) myotubes. However, coimmunoprecipitation experiments demonstrated no evidence for a direct protein-protein association between the nAChR and nNOS in C(2)C(12) myotubes. An antibody to the alpha(1)-subunit of the nAChR did not coprecipitate nNOS, and an nNOS-specific antibody did not precipitate the alpha(1)-subunit of the nAChR. Treatment of mice with bacterial LPS downregulated the expression of nNOS in skeletal muscle, and treatment of C(2)C(12) cells with bacterial LPS and interferon-gamma markedly decreased nNOS mRNA and protein expression. In contrast, mRNA and protein of the nAChR (alpha-, gamma-, and epsilon-subunits) remained unchanged at the mRNA and protein levels. These data demonstrate that nNOS and the nAChR are colocalized in murine skeletal muscle and C(2)C(12) cells but differ in their expressional regulation.