Effects of corticotropin-releasing hormone on proopiomelanocortin derivatives and monocytic HLA-DR expression in patients with septic shock

Little is known about interactions between immune and neuro-endocrine systems in patients with septic shock. We therefore evaluated whether the corticotropin-releasing hormone (CRH) and/or proopiomelanocortin (POMC) derivatives [ACTH, β-endorphin (β-END), β-lipotropin (β-LPH), α-melanocyte stimulating hormone (α-MSH) or N-acetyl-β-END (Nac-β-END)] have any influences on monocyte deactivation as a major factor of immunosuppression under septic shock conditions. Sixteen patients with septic shock were enrolled in a double-blind, cross-over and placebo controlled clinical study; 0.5 μg/(kg_bodyweight h) CRH (or placebo) were intravenously administered for 24 h. Using flow cytometry we investigated the immunosuppression in patients as far as related to the loss of leukocyte surface antigen-DR expression on circulating monocytes (mHLA-DR). ACTH, β-END immunoreacive material (IRM), β-LPH IRM, α-MSH and Nac-β-END IRM as well as TNF-α and mHLA-DR expression were determined before, during and after treatment with CRH (or placebo). A significant correlation between plasma concentration of α-MSH and mHLA-DR expression and an inverse correlation between mHLA-DR expression and TNF-α plasma level were found. Additionally, a significant increase of mHLA-DR expression was observed 16 h after starting the CRH infusion; 8 h later, the mHLA-DR expression had decreased again. Our results indicate that the up-regulation of mHLA-DR expression after CRH infusion is not dependent on the release of POMC derivatives. From the correlation between plasma concentration of α-MSH and mHLA-DR expression, we conclude that in patients with septic shock the down-regulation of mHAL-DR expression is accompanied by the loss of monocytic release of α-MSH into the cardiovascular compartment.     

Breast cancer cell behaviors on staged tumorigenesis-mimicking matrices derived from tumor cells at various malignant stages

Extracellular matrix (ECM) has been focused to understand tumor progression in addition to the genetic mutation of cancer cells. Here, we prepared “staged tumorigenesis-mimicking matrices” which mimic in vivo ECM in tumor tissue at each malignant stage to understand the roles of ECM in tumor progression. Breast tumor cells, MDA-MB-231 (invasive), MCF-7 (non-invasive), and MCF-10A (benign) cells, were cultured to form their own ECM beneath the cells and formed ECM was prepared as staged tumorigenesis-mimicking matrices by decellularization treatment. Cells showed weak attachment on the matrices derived from MDA-MB-231 cancer cells. The proliferations of MDA-MB-231 and MCF-7 was promoted on the matrices derived from MDA-MB-231 cancer cells whereas MCF-10A cell proliferation was not promoted. MCF-10A cell proliferation was promoted on the matrices derived from MCF-10A cells. Chemoresistance of MDA-MB-231 cells against 5-fluorouracil increased on only matrices derived from MDA-MB-231 cells. Our results showed that the cells showed different behaviors on staged tumorigenesis-mimicking matrices according to the malignancy of cell sources for ECM preparation. Therefore, staged tumorigenesis-mimicking matrices might be a useful in vitro ECM models to investigate the roles of ECM in tumor progression.     

Up-regulation of Na-coupled glucose transporter SGLT1 by caveolin-1

The Na⁺-coupled glucose transporter SGLT1 (SLC5A1) accomplishes concentrative cellular glucose uptake even at low extracellular glucose concentrations. The carrier is expressed in renal proximal tubules, small intestine and a variety of nonpolarized cells including several tumor cells. The present study explored whether SGLT1 activity is regulated by caveolin-1, which is known to regulate the insertion of several ion channels and carriers in the cell membrane. To this end, SGLT1 was expressed in Xenopus oocytes with or without additional expression of caveolin-1 and electrogenic glucose transport determined by dual electrode voltage clamp experiments. In SGLT1-expressing oocytes, but not in oocytes injected with water or caveolin-1 alone, the addition of glucose to the extracellular bath generated an inward current (I_g), which was increased following coexpression of caveolin-1. Kinetic analysis revealed that caveolin-1 increased maximal I_g without significantly modifying the glucose concentration required to trigger half maximal I_g (K_M). According to chemiluminescence and confocal microscopy, caveolin-1 increased SGLT1 protein abundance in the cell membrane. Inhibition of SGLT1 insertion by brefeldin A (5 μM) resulted in a decline of I_g, which was similar in the absence and presence of caveolin-1. In conclusion, caveolin-1 up-regulates SGLT1 activity by increasing carrier protein abundance in the cell membrane, an effect presumably due to stimulation of carrier protein insertion into the cell membrane.     

Discovery and structure–activity relationships of 6-(benzoylamino)benzoxaboroles as orally active anti-inflammatory agents

Structure–activity relationships of 6-(benzoylamino)benzoxaborole analogs were investigated for the inhibition of TNF-α, IL-1β, and IL-6 from lipopolysaccharide stimulated peripheral blood mononuclear cells. Compound 1q showed potent activity against all three cytokines with IC₅₀ values between 0.19 and 0.50 μM, inhibited LPS-induced TNF-α and IL-6 elevation in mice and improved collagen-induced arthritis in mice. Compound 1q (AN4161) is considered to be a promising lead for novel anti-inflammatory agent with an excellent pharmacokinetic profile.     

Effects of the methoxy group in the side chain of debromoaplysiatoxin on its tumor-promoting and anti-proliferative activities

Debromoaplysiatoxin (DAT) is a tumor promoter isolated from sea hare and exhibits anti-proliferative activity against several cancer cell lines. To clarify key residues that are responsible for its tumor-promoting activity, we focused on the chiral methoxy group in the side chain, whose role had not yet been discussed or examined before. Demethoxy-DAT (8) was derived from DAT and we evaluated its tumor-promoting activity, anti-proliferative activity, and ability to bind to protein kinase C (PKC) isozymes. Compound 8 showed somewhat weaker tumor-promoting activity than that of DAT both in vitro and in vivo, but showed higher anti-proliferative activity against several cancer cell lines. Although the affinity to novel PKC isozymes of 8 was comparable to that of DAT, the affinity to conventional PKC isozymes decreased slightly. These results suggest that the methoxy group of DAT is one of the key residues critical for tumor-promoting activity but not for anti-proliferative activity. Since the methoxy group has little influence on the molecular hydrophobicity, this is the first report showing that structural factors other than hydrophobicity in the side chain of DAT affected its biological activities.     

Design and synthesis of MMP inhibitors with appended fluorescent tags for imaging and visualization of matrix metalloproteinase enzymes

We describe the synthesis, MMP-2 and 9 potency, and in vitro evaluation of a series of α-sulfone hydroxmate MMP inhibitors conjugated to a series of dyes with different absorption/emission lamina maxima’s that can be used to visualize tumors.     

肥胖者脂肪组织中TNF-α表达与脂肪细胞大小的相关性分析

目的探讨肥胖者网膜脂肪和皮下脂肪两处肿瘤坏死因子-α(TNF-α)蛋白的表达与脂肪细胞大小的相关性。方法选取正常体重者16名,中心型肥胖者32名拟行外科手术患者,术中取出网膜脂肪和皮下脂肪标本,测定脂肪细胞大小,采用western blot方法测定TNF-α蛋白表达。结果肥胖者网膜脂肪和皮下脂肪两处TNF-α蛋白的水平均比正常体重对照组表达高(P<0.01),肥胖者网膜脂肪组织TNF-α蛋白表达高于皮下脂肪(P<0.05),同时研究发现肥胖者皮下脂肪细胞和网膜脂肪细胞大小均明显大于正常体重组(P<0.05),且肥胖者网膜脂肪和皮下脂肪两处脂肪组织TNF-α蛋白表达与脂肪细胞大小呈正相关(网膜:r=0.808,P<0.01;皮下:r=0.452,P<0.05)。结论肥胖者网膜脂肪和皮下脂肪细胞增大,在肥胖相关胰岛素抵抗的发生中起到了重要的作用。     

Activation of TLR4 signaling promotes gastric cancer progression by inducing mitochondrial ROS production

Chronic infection, such as Helicobacter pylori infection, has been associated with the development of gastric cancer (GC). Pathogen-associated molecular patterns can trigger inflammatory responses via Toll-like receptors (TLRs) in GC. Here we showed that Toll-like receptor 4 (TLR4) was highly expressed in GC cells and was associated with the aggressiveness of GC. The binding of lipopolysaccharide (LPS) to TLR4 on GC cells enhanced proliferation without affecting apoptosis. Higher level of reactive oxygen species (ROS) was induced after activation of TLR4 signaling in GC. Using oxidase inhibitors and antioxidants, we found that mitochondrial ROS (mROS) was major source of TLR4-stimulated ROS generation. This elevated mROS production can be inhibited by diphenylene iodonium (DPI), and the blocking of the mROS production rather than ROS neutralization resulted in cell cycle arrest and the loss of mitochondrial potential, which were plausible reason for decreased cell viability. Furthermore, the increased mROS owing to TLR4 signaling resulted in the activation of Akt phosphorylation and NF-κB p65 nuclear translocation. Altogether, these results reveal a novel pathway linking innate immune signaling to GC cell proliferation, implicate mROS as an important component of cell survival signals and further establish mitochondria as hubs for GC therapies.