Inhibition of fibroblast proliferation in a culture of human endometrial stromal cells using a medium containing D-valine

Promising Application of D-Amino Acids toward Clinical Therapy

The versatile roles of D-amino acids (D-AAs) in foods, diseases, and organisms, etc., have been widely reported. They have been regarded, not only as biomarkers of diseases but also as regulators of the physiological function of organisms. Over the past few decades, increasing data has revealed that D-AAs have great potential in treating disease. D-AAs also showed overwhelming success in disengaging biofilm, which might provide promise to inhibit microbial infection. Moreover, it can effectively restrain the growth of cancer cells. Herein, we reviewed recent reports on the potential of D-AAs as therapeutic agents for treating neurological disease or tissue/organ injury, ameliorating reproduction function, preventing biofilm infection, and inhibiting cancer cell growth. Additionally, we also reviewed the potential application of D-AAs in drug modification, such as improving biostability and efficiency, which has a better effect on therapy or diagnosis.

Subtype-Specific Tumor-Associated Fibroblasts Contribute to the Pathogenesis of Uterine Leiomyoma

Recent genomic studies have identified subtypes of uterine leiomyoma (LM) with distinctive genetic alterations. Here, we report the elucidation of the biological characteristics of the two most prevalent uterine leiomyoma subtypes, MED12-mutant (MED12-LM) and HMGA2-overexpressing (HMGA2-LM) uterine leiomyomas. Because each tumor carries only one genetic alteration, both subtypes are considered to be monoclonal. Approximately 90% of cells in HMGA2-uterine leiomyoma were smooth muscle cells (SMC) with HMGA2 overexpression. In contrast, MED12-LM consisted of similar numbers of SMC and non-SMC, which were mostly tumor-associated fibroblasts (TAF). Paradoxically, TAF carried no mutations in MED12, suggesting an interaction between SMC and TAF to coordinate their growth. The higher amount of extracellular matrix in MED12-LM than HMGA2-LM was partially due to the high concentration of collagen-producing TAF. SMC growth in a xenograft assay was driven by progesterone in both uterine leiomyoma subtypes. In contrast, TAF in MED12-LM proliferated in response to estradiol, whereas progesterone had no effect. The high concentration of estrogen-responsive TAF in MED12-LM explains the inconsistent discoveries between in vivo and in vitro studies on the mitogenic effect of estrogen and raises questions regarding the accuracy of previous studies utilizing MED12-LM cell culture. In addition, the differential effects of estradiol and progesterone on these uterine leiomyoma subtypes emphasize the importance of subtypes and genotypes in designing nonsurgical therapeutic strategies for uterine leiomyoma. Cancer Res; 77(24); 6891-901. ©2017 AACR.

Isolation of embryonic ventricular endothelial cells

Cell culture has greatly enhanced our ability to assess individual populations of cells under myriad culture conditions. While immortalized cell lines offer significant advantages for their ease of use, these cell lines are unavailable for all potential cell types. By isolating primary cells from a specific region of interest, particularly from a transgenic mouse, more nuanced studies can be performed. The basic technique involves dissecting the organ or partial organ of interest (e.g. the heart or a specific region of the heart) and dissociating the organ to single cells. These cells are then incubated with magnetic beads conjugated to an antibody that recognizes the cell type of interest. The cells of interest can then be isolated with the use of a magnet, with a short trypsin incubation dissociating the cells from the beads. These isolated cells can then be cultured and analyzed as desired. This technique was originally designed for adult mouse organs but can be easily scaled down for use with embryonic organs, as demonstrated herein. Because our interest is in the developing coronary vasculature, we wanted to study this population of cells during specific embryonic stages. Thus, the original protocol had to be modified to be compatible with the small size of the embryonic ventricles and the low potential yield of endothelial cells at these developmental stages. Utilizing this scaled-down approach, we have assessed coronary plexus remodeling in transgenic embryonic ventricular endothelial cells.

Comparative analysis of EspF variants in inhibition of Escherichia coli phagocytosis by macrophages and inhibition of E. coli translocation through human- and bovine-derived M cells

The EspF protein is secreted by the type III secretion system of enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). EspF sequences differ between EHEC O157:H7, EHEC O26:H11, and EPEC O127:H6 in terms of the number of SH3-binding polyproline-rich repeats and specific residues in these regions, as well as residues in the amino domain involved in cellular localization. EspF(O127) is important for the inhibition of phagocytosis by EPEC and also limits EPEC translocation through antigen-sampling cells (M cells). EspF(O127) has been shown to have effects on cellular organelle function and interacts with several host proteins, including N-WASP and sorting nexin 9 (SNX9). In this study, we compared the capacities of different espF alleles to inhibit (i) bacterial phagocytosis by macrophages, (ii) translocation through an M-cell coculture system, and (iii) uptake by and translocation through cultured bovine epithelial cells. The espF gene from E. coli serotype O157 (espF(O157)) allele was significantly less effective at inhibiting phagocytosis and also had reduced capacity to inhibit E. coli translocation through a human-derived in vitro M-cell coculture system in comparison to espF(O127) and espF(O26). In contrast, espF(O157) was the most effective allele at restricting bacterial uptake into and translocation through primary epithelial cells cultured from the bovine terminal rectum, the predominant colonization site of EHEC O157 in cattle and a site containing M-like cells. Although LUMIER binding assays demonstrated differences in the interactions of the EspF variants with SNX9 and N-WASP, we propose that other, as-yet-uncharacterized interactions contribute to the host-based variation in EspF activity demonstrated here.

Platelet-derived endothelial cell growth factor mediates angiogenesis and antiapoptosis in rat aortic endothelial cells

This study explores the angiogenic and antiapoptotic activities of platelet-derived endothelial cell growth factor (PDECGF) in rat aortic endothelial cells. The effects of PDECGF on rat aortic endothelial cell (RAEC) proliferation, migration, chemotaxis, and tubule formation were investigated in vitro at various concentrations viz., 1, 2, 4, 8, 16, and 32 ng·mL–1 on endothelial cells. Endothelial cells were induced with hypoxic stress and the antiapoptotic effects of PDECGF were analysed by cell survival assay, fluorescence microscopy, cell viability assay, and flow cytometry. The results demonstrated the angiogenic potential of PDECGF on endothelial cells in a dose-dependent manner. PDECGF at 16 and 32 ng·mL–1 increased cell proliferation (>80%), induced cell migration (>4 fold), stimulated chemotaxis (>2 fold), and increased tubule formation (>3 fold) compared with the control. Studies on hypoxic stress revealed the antiapoptotic nature of PDECGF on endothelial cells. PDECGF treatment enhanced cell survival by 14%, as well as cell viability by 13%, and decreased the percentage of apoptotic cells by 13% as demonstrated by fluorescence-activated cell sorter studies (FACS). In conclusion, this study demonstrated the angiogenic and antiapoptotic potentials of PDECGF on RAEC.

Human periosteum-derived cells from elderly patients as a source for cartilage tissue engineering?

The aim of this study was to establish the potential of human periosteum-derived cells from elderly patients as a cell source for cartilage tissue engineering by optimizing culture conditions for both proliferation and differentiation. Periosteum was obtained from the tibiae of nine patients. Biopsies were prepared for routine histological examination. Periosteum-derived cells were allowed to grow out from the remaining tissue, and were expanded in minimum essential medium containing D-valine (MEM-DV). Fetal bovine serum (FBS) or substitutes, fibroblast growth factor-2 (FGF-2), insulin-like growth factor-1 (IGF-1) and non-essential amino acids were added to study proliferation. For differentiation of cells, serum-free medium was used supplemented with one or more isoforms of transforming growth factor-beta (TGFbeta) and/or IGF-1. Samples were analysed for expression of collagens type I, II and X by competitive RT-PCR, immunohistochemically, and histologically using Alcian blue staining. In all samples the cambium layer could hardly be detected. Periosteum-derived cells proliferated in serum-containing MEM-DV. Optimal proliferation was found when this medium was supplemented with 100 ng/ml FGF-2 and non-essential amino acids. Chondrogenesis was detected in 59% of micromasses that were cultured with TGFbeta isomers, and in 83% of the samples cultured in media to which two TGFbeta isoforms were added. Periosteum from elderly humans (mean age 66, range 41-76 years) has chondrogenic potential and remains an attractive cell source for cartilage tissue engineering. By expanding cells in MEM-DV, the selection of progenitor cells might be favoured, which would result in a higher cartilage yield for tissue engineering applications.

[Tissue engineering in urology. Basic principles and application]

Tissue engineering is a rather new field of science. Despite this fact, some experimental investigations have already been applied in clinical studies. Compared to other medical fields, tissue engineering in urology is well established. Tissue-engineered bulking agents and tissue-engineered bladder augments are being investigated in clinical trials. Even though the knowledge gained in recent years is promising, the results of cellular therapies need to be critically judged before being finally applied in patients. Genetic engineering and stem cell research (adult undifferentiated cells) have had major impact on the field of tissue engineering over the past 2 years. By using the technology of genetic engineering, biochemical and functional qualities of tissues may be modified. Adult stem cells may help to substitute lost tissue in an autologous fashion by isolating undifferentiated cells from the body and by differentiating them into a desired cell type. These cells may be used to form native functional tissue to replace a diseased organ or organ part.

Verotoxin 1 binding to intestinal crypt epithelial cells results in localization to lysosomes and abrogation of toxicity

Verotoxins (VTs) are important virulence factors of enterohaemorrhagic Escherichia coli (EHEC), a group of bacteria associated with severe disease sequelae in humans. The potent cytotoxic activity of VTs is important in pathogenicity, resulting in the death of cells expressing receptor Gb3 (globotriaosylceramide). EHEC, particularly serotype O157:H7, frequently colonize reservoir hosts (such as cattle) in the absence of disease, however, the basis to avirulence in this host has been unclear. The objective of this study was assessment of interaction between VT and intestinal epithelium, which represents the major interface between the host and enteric organisms. Bovine intestinal epithelial cells expressed Gb3 in vitro in primary cell cultures, localizing specifically to proliferating crypt cells in corroboration with in situ immunohistological observations on intestinal mucosa. Expression of receptor by these cells contrasts with the absence of Gb3 on human intestinal epithelium in vivo. Despite receptor expression, VT exhibited no cytotoxic activity against bovine epithelial cells. Sub-cellular localization of VT indicated that this toxin was excluded from endoplasmic reticulum but localized to lysosomes, corresponding with abrogation of cytotoxicity. VT intracellular trafficking was unaffected by treatment of primary cell cultures with methyl-beta-cyclodextrin, indicating that Gb3 in these cells is not associated with lipid rafts but is randomly distributed in the membrane. The combination of Gb3 isoform, membrane distribution and VT trafficking correlate with observations of other receptor-positive cells that resist verocytotoxicity. These studies demonstrate that intestinal epithelium is an important determinant in VT interaction with major implications for the differential consequences of EHEC infection in reservoir hosts and humans.

Protein kinase G activation of K(ATP) channels in human-cultured prostatic stromal cells

In this study, we identify and investigate the role of protein kinase G (PKG) in cells cultured from human prostatic stroma. Cells were used for immunocytochemistry, contractility or K(+) fluorescent imaging studies. All cultured prostatic stromal cells showed PKG immunostaining. Phorbol 12,13 diacetate (PDA, 1 microM) elicited contractions from human-cultured prostatic stromal cells that could be blocked by both the L-type Ca(2+) channel blocker, nifedipine (3 microM), and the protein kinase C inhibitor, bisindolylmaleimide (1 microM). The nitric oxide donor, sodium nitroprusside (SNP, molar pIC(50) 5.16+/-0.17) and the cGMP-phosphodiesterase inhibitor, zaprinast (50 microM), inhibited PDA (1 microM)-induced contractions. The PKG activator beta-phenyl-1, N(2)-ethenoguanosine-3',5'-cyclic monophosphate (PET-cGMP, molar pIC(50) 6.96 +/- 0.25) also inhibited PDA (1 microM)-induced contractions. Glibenclamide (10 microM) and Rp-8-Br-cGMPS (5 microM), but not iberiotoxin (100 nM) or Rp-cAMP (5 microM), reversed this inhibition. In human-cultured prostatic stromal cells loaded with the K(+) fluorescent indicator, 1,3-Benzenedicarboxylic acid, 4,4'-[1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diylbis(5-methoxy-6,2-benzofurandiyl)]bis-, tetrakis [(acetyloxy) methyl] ester (PBFI), PET-cGMP (300 nM) caused a reduction in intracellular K(+) that was blocked by glibenclamide (10 microM) and Rp-8-Br-cGMPS (5 microM), but not by iberiotoxin (100 nM). These data are consistent with the hypothesis that, in human-cultured prostatic stromal cells, PKG inhibits contractility through the activation of K(ATP) channels.

Human endometrial cells grown on an extracellular matrix form simple columnar epithelia and glands

Normal human endometrial cells were grown on an extracellular matrix containing type IV collagen, laminin, heparan sulfate proteoglycan, and entactin (Matrigel). On the extracellular matrix, dispersed endometrial cells remained rounded, and aggregated to form mounds of cells, which continued to grow in this arrangement. At 10 d, light microscopy demonstrated that these mounds were comprised of an eosinophilic substance, containing individual fusiform stromal cells. About 50% of the mounds were covered with a single layer of polarized cuboidal to columnar cells with basal nuclei, whereas 60% contained columnar cells forming glandular structures with open lumina. These polarized cuboidal and columnar cells were epithelial, based on their positive staining for cytokeratins and the possession of microvilli, tonofilaments, abundant glycogen, ribosomes, and primitive junctional complexes. Kreyberg's stain showed the presence of mucin within the lumina of the glands, indicating that they were functional. Thus, human endometrial cells grown on an extracellular matrix form a simple cuboidal to columnar epithelium, a stromal component, and glandular structures, thereby mimicking the in vivo morphology of the endometrium.