Objectives: Epithelial-mesenchymal transition (EMT) is an important process in tumor development, and several studies suggest that the Wnt/b-catenin signal pathway may play an important role in EMT. However, there is no direct evidence showing that the Wnt/b-catenin pathway actually determines the EMT induced by an exogenous signal. Our previous research has successfully proved that overexpression of hypoxiainducible factor-1a (HIF-1a) could induce EMT in LNCaP cells, but not in PC-3. The present study aims to determine whether the signal of HIF-1a for inducing prostate cancer cells to undergo EMT might possibly pass through the Wnt/b-catenin pathway. Methods: Epithelial-mesenchymal transition associated proteins were detected in several human prostate carcinoma cell lines by Western blot, and then we distinguished the EMT positive cell lines from the EMT negative cell lines. Furthermore, we evaluated the possible correlation between potency of invasiveness and proliferation among these cell lines with different characteristics of EMT using Matrigel transwell and thiazolyl blue tetrazolium bromide (MTT) assays. Finally, the different expression of some critical proteins and genes in Wnt/b-catenin signaling pathway were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) in these cells with different characteristics of EMT. Results: Among several prostate cancer cell lines, PC-3, LNCaP and PC-3/HIF-1a are EMT negative cell lines, whereas LNCaP/HIF-1a and IA8 have undergone the EMT process. EMT positive cells (LNCaP/HIF-1a and IA8) exhibit much stronger potency of invasiveness and proliferation than those of PC-3 and LNCaP, which belong to EMT negative cells. Interestingly, although PC-3/HIF-1a had not completed the EMT process, it still displayed stronger potency of invasion and proliferation, resembling EMT positive cells. The protein expression level of total glycogensynthase kinase 3b (GSK-3b) and phospho-GSK-3b in LNCaP/HIF-1a, IA8 and PC-3/HIF-1a cells significantly decreased; however, the relative ratios of p-GSK3b/t-GSK3b in LNCaP/HIF-1a, IA8 and PC-3/HIF-1a cells were significantly higher than PC-3 and LNCaP. Consistently, b-catenin protein expression increased in LNCaP/HIF-1a and IA8 cells, but not in PC-3/HIF-1a; RT-PCR confirmed these results, except for the enhanced transcription activity of b-catenin mRNA in PC-3/HIF-1a. Conclusion: Our data suggests that activation of the Wnt/b-catenin signaling pathway correlates with the characteristic of EMT and potency of invasiveness and proliferation. This may be the critical factor that directly controls the process of EMT induced by HIF-1a in prostate cancer cells.

Urinary tract infections are the most common infection in renal transplant patients and Escherichia coli (E. coli) is the most common clinical isolate. Although acute allograft injury (AAI) secondary to urinary tract infection (UTI) has been reported, the incidence of AAI associated with UTI, the virulence factors express by uropathic E. coli and whether virulence factors are associated with renal allograft outcome have not been described. We collected E. coli from our renal transplant patients with UTI, determined O:H serotypes, P and Dr fimbriae expression and the clinical presentation and allograft function during the UTI and post-UTI period. Pyelonephritis occurred in 40% of our patients, 82% of which had AAI (>20% increase in SCr). Sixtytwo percent of E. coli isolates that expressed P fimbriae were associated with AAI, whereas only 29% that did not express P fimbriae had AAI (p = 0.03). The pattern of P fimbriae and O serotypes differed from reported isolates, as the P fimbriae PapG class II and the O25 serotype were the most common. Dr adhesin was expressed on 7 isolates, including 2 of 3 with urosepsis. We propose a unique pattern of uropathogenic serotypes and adherence factors contribute to acute allograft injury in renal transplant patients with UTI.

Older adults suffer from weakened and delayed bone healing due to age-related alterations in bone cells and in the immune system. Given the interaction between the immune system and skeletal cells, therapies that address deficiencies in both the skeletal and the immune system are required to effectively treat bone injuries of older patients. The sequence of macrophage activation observed in healthy tissue repair involves a transition from a pro-inflammatory state followed by a pro-reparative state. In older patients, inflammation is slower to resolve and impedes healing. The goal of this study was to design a novel drug delivery system for temporal guidance of the polarization of macrophages using bone grafting materials. A biomimetic calcium phosphate coating (bCaP) physically and temporally separated the pro-inflammatory stimulus interferon-gamma (IFNγ) from the pro-reparative stimulus simvastatin (SIMV). Effective doses were identified using a human monocyte line (THP-1) and testing culminated with bone marrow macrophages obtained from old mice. Sequential M1-to-M2 activation was achieved with both cell types. These results suggest that this novel immunomodulatory drug delivery system holds potential for controlling macrophage activation in bones of older patients.

Oxidized low density lipoprotein (OxLDL) has multiple proatherogenic effects, including induction of apoptosis. We have recently shown that OxLDL markedly downregulates insulin-like growth factor-1 receptor (IGF-1R) in human aortic smooth muscle cells, and that IGF-1R overexpression blocks OxLDL-induced apoptosis. We hypothesized that specific OxLDL-triggered signaling events led to IGF-1R downregulation and apoptosis. We examined OxLDL signaling pathways and found that neither IGF-1R downregulation nor the proapoptotic effect was blocked by inhibition of OxLDLtriggered extracellular signal-regulated kinase, p38 mitogenactivated protein kinase (MAPK), or peroxisome proliferatoractivated receptor ␥ (PPAR ␥ ) signaling pathways, as assessed using specific inhibitors. However, antioxidants, polyethylene glycol catalase, superoxide dismutase, and Trolox completely blocked OxLDL downregulation of IGF-1R and OxLDLinduced apoptosis. Nordihydroguaiaretic acid, AA-861, and baicalein, which are lipoxygenase inhibitors and also have antioxidant activity, blocked IGF-1R downregulation and apoptosis as well as reactive oxygen species (ROS) production. These results suggest that OxLDL enhances ROS production possibly through lipoxygenase activity, leading to IGF-1R downregulation and apoptosis. Furthermore, anti-CD36 scavenger receptor antibody markedly inhibited Ox-LDL-induced IGF-1R downregulation and apoptosis as well as ROS production. In conclusion, our data demonstrate that OxLDL downregulates IGF-1R via redox-sensitive pathways that are distinct from OxLDL signaling through MAPKand PPAR ␥ -involved pathways but may involve a CD36-dependent mechanism.