Inhibitory effects of lysophosphatidic acid receptor-5 on cellular functions of sarcoma cells

Abstract

Lysophosphatidic acid (LPA) is a bioactive lipid that interacts with G protein-coupled LPA receptors (LPA receptor-1 (LPA₁) to LPA₆). Here, we investigated the effects of LPA signaling via LPA₅ on cellular functions of sarcoma cells by generating Lpar5 overexpressing and Lpar5 knockdown cells from rat osteosarcoma and malignant fibrous histiocytoma cells, respectively. The cell motility activity of Lpar5 overexpressing cells was significantly lower, while Lpar5 knockdown cells showed high cell motility, compared with respective controls. Gelatin zymography showed that LPA₅ suppressed the activation of matrix metalloproteinase-2. LPA₅ also inhibited the cell motility activity of endothelial cells, correlating with the expression levels of vascular endothelial growth factor genes. These results suggest that LPA signaling via LPA₅ negatively regulates the cellular functions of rat sarcoma cells.     

Duodenal gastric heterotopia,sporadic or fundic gland polyp-associated,frequently carries β-catenin mutation

Duodenal gastric heterotopia (DGH) is a benign asymptomatic condition assumed to be of congenital origin. Since DGH is often associated with fundic gland polyps (FGPs) that frequently carry a somatic β-catenin gene mutation, we examined whether DGH, either sporadic or FGP-associated, is attributable to alterations of the Wnt/β-catenin pathway. Genetic analysis revealed frequent somatic β-catenin gene mutations in DGH; some of which showed the same mutation pattern as coexisting FGPs. All missense mutations were confined to codons 32, 33, and 37. No such mutations were observed, however, in any of the specimens from focal gastric foveolar metaplasia (GFM). Therefore, DGH is not a mere congenital lesion due to aberrant migration of normal gastric mucosa or a simple reactive metaplasia after regenerative stimuli of the duodenal mucosa, but a distinct condition based upon molecular genetic changes in the Wnt/β-catenin pathway.     

Significance of adenocarcinoma-associated antigen YH206 levels in the pancreatic juice

We measured the pancreatic juice levels of antigen YH206, which is a new tumor marker of adenocarcinomas detected by monoclonal antibody YH206 (Hinoda et al., Int. J Cancer 24(5):653-658, 1988). Sandwich enzyme immunoassay revealed that samples from patients with pancreas cancer (n = 21) showed significantly higher values (P less than 0.01) than those of healthy controls (n = 15). Eight out of 21 (38.1%) samples from patients with pancreas cancer showed more than 100 U/ml, whereas only one out of 20 (5.0%) from patients with chronic pancreatitis exhibited more than 100 U/ml of antigen YH206. Simultaneous measurement of antigen YH206 and CA19-9 demonstrated that although a higher incidence of positivity in the case of pancreas cancer was obtained for both antigens, antigen YH206 showed much lower incidence of positivity (14%) than CA19-9 (57%) in patients with chronic pancreatitis. Therefore, the measurement of antigen YH206 in the pancreatic juice could be of use for the diagnosis of pancreas cancer.     

A 2000 patient retrospective assessment of a new strategy for burn wound management in view of infection prevention and treatment

Infections in burn patients are still the principal cause of complications in burn injuries. The aim of this study is to assess a new strategy for burn wound management in view of infection prevention and treatment in the experience of the Burn Treatment Center in Siemianowice Śląskie. The applied methodology involved the analysis of patient records describing the hospital''s epidemiological situation between 2014 and 2016. The analysis also included the use and cost of antibiotics, silver‐containing dressings, and other antiseptics relative to the number of sepsis cases, including those caused by Pseudomonas aeruginosa, as well as the mortality ratio. The total costs of prevention and treatment of infections were reduced, while the use of silver‐containing dressings and antiseptics increased. The number of patients with sepsis decreased, including cases caused by P. aeruginosa, and the mortality ratio was reduced. Introducing a strategy for burn wound‐oriented infection prevention and treatment in burn patients provides a number of benefits. It is also cost‐effective. Using locally applied active dressings and antiseptics can be a welcome choice for often‐unnecessary antibiotic therapy of a suspected or existing burn wound infection.     

Antigen‐specific airway IL‐33 production depends on FcγR‐mediated incorporation of the antigen by alveolar macrophages in sensitized mice

Although interleukin (IL)‐33 is a candidate for the aggravation of asthma, the mechanisms underlying antigen‐specific IL‐33 production in the lung are unclear. Therefore, we analysed the mechanisms in mice. Intra‐tracheal administration of ovalbumin (OVA) evoked increases in IL‐33 and IL‐33 mRNA in the lungs of both non‐sensitized and OVA‐sensitized mice, and the increases in the sensitized mice were significantly higher than in the non‐sensitized mice. However, intra‐tracheal administration of bovine serum albumin did not increase the IL‐33 level in the OVA‐sensitized mice. Depletion of neither mast cells/basophils nor CD4⁺ cells abolished the OVA‐induced IL‐33 production in sensitized mice, suggesting that the antigen recognition leading to the IL‐33 production was not related with either antigen‐specific IgE‐bearing mast cells/basophils or memory CD4⁺ Th2 cells. When a fluorogenic substrate‐labelled OVA (DQ‐OVA) was intra‐tracheally administered, the lung cells of sensitized mice incorporated more DQ‐OVA than those of non‐sensitized mice. The lung cells incorporating DQ‐OVA included B‐cells and alveolar macrophages. The allergic IL‐33 production was significantly reduced by treatment with anti‐FcγRII/III mAb. Depletion of alveolar macrophages by clodronate liposomes significantly suppressed the allergic IL‐33 production, whereas depletion of B‐cells by anti‐CD20 mAb did not. These results suggest that the administered OVA in the lung bound antigen‐specific IgG Ab, and then alveolar macrophages incorporated the immune complex through FcγRII/III on the cell surface, resulting in IL‐33 production in sensitized mice. The mechanisms underlying the antigen‐specific IL‐33 production may aid in development of new pharmacotherapies.     

Sialyl LewisX mimic-decorated liposomes for anti-angiogenic everolimus delivery to E-selectin expressing endothelial cells

In this study, we developed novel E-selectin-targeting liposomes, i.e., 3′-(1-carboxy)ethyl sialyl LewisX (3′-CE sLeX) mimic liposomes, for targeted delivery of everolimus (EVE) in anti-angiogenic therapy. We investigated the uptake and efficacy of these E-selectin targeting liposomes in inflammatory cytokine-treated human umbilical vein endothelial cells (HUVECs). The uptake of EVE in 3′-CE sLeX mimic liposomes increased steadily and almost caught up with the uptake of plain EVE at 3 h, which was higher than that in PEGylated liposomes (PEG-liposomes). Inhibition of uptake by anti-E-selectin antibody suggested involvement of E-selectin-mediated endocytotic processes. Migration in cells treated with EVE/3′-CE sLeX mimic liposomes was suppressed by more than half when compared to the control. This treatment was also seen to significantly inhibit the formation of capillary tubes and networks. In addition, Thr389 phosphorylation of pS6 kinase, as a marker of mTOR activity, was remarkably suppressed to less than endogenous levels by EVE/3′-CE sLeX mimic liposomes. In conclusion, the present study demonstrated that EVE/3′-CE sLeX mimic liposomes were intracellularly taken up by E-selectin and prompted anti-angiogenic effects of EVE involved in the mTOR signaling pathway. However, moderate retention of EVE in the liposomes might limit the targeting ability of 3′-CE sLeX mimic liposomes.

Novel E-selectin-targeting liposomes deliver everolimus to E-selectin expressing endothelial cells and accelerate its anti-angiogenic effect.