Pleiotropic,Unique and Shared Responses Elicited by IL-6 Family Cytokines in Human Vascular Endothelial Cells

Vascular endothelial cells express glycoprotein 130 (gp130), which is utilized as a signaling receptor by cytokines in the interleukin-6 (IL-6) family. Several IL-6 family cytokines can be found in the circulatory system during physiological or pathological conditions, and may influence endothelial function and response. This study evaluated and compared the cellular and molecular responses induced by IL-6 family cytokines in human endothelial cells. A proteomic analysis showed that IL-6 family cytokines induce the release of a range of proteins from endothelial cells, such as C-C motif chemokine ligand 23, hepatocyte growth factor, and IL-6. Pathway analysis indicated that gp130-signaling in endothelial cells regulates several functions related to angiogenesis and immune cell recruitment. The present investigation also disclosed differences and similarities between different IL-6 family cytokines in their ability to induce protein release and regulate gene expression and intracellular signaling, in regards to which oncostatin M showed the most pronounced effect. Further, this study showed that soluble gp130 preferentially blocks trans-signaling-induced responses, but does not affect responses induced by classic signaling. In conclusion, IL-6 family cytokines induce both specific and overlapping molecular responses in endothelial cells, and regulate genes and proteins involved in angiogenesis and immune cell recruitment.     

Performance of solar driven methanol–water combined ejector–absorption cycle in the Athens area

The performance of a solar driven CH₄O-H₂O combined ejector– absorption unit, operating in conjunction with intermediate temperature solar collectors in Athens, is predicted along the five months (May–September) in case of the unit working as heat pump in an industrial area. The operation of the unit and the related thermodynamics are simulated by suitable computer codes and the required local climatological data are determined by statistical processings over a considerable number of years. It is found that the heat gain factor varies in the range from 2.1330 to 2.4481 for the above period of time. The maximum HGF of about 2.4481 is obtained in July at 14.25 hrs with corresponding specific heat gain power 915 W/m². The maximum Q_gain of about 1086 W/m² is obtained in June at 12.54 hrs with corresponding HGF 2.3572. Also the maximum value of HGF was estimated by correlation of three temperatures: generator temperature (85.0°C–97.2°C), condenser temperature (43.3°C–47.6°C) and evaporator temperature (12.6°C–25.4°C).     

Effect of a hepatocyte growth factor/heparin-immobilized collagen system on albumin synthesis and spheroid formation by hepatocytes

A hepatocyte growth factor (HGF)/heparin-immobilized collagen system was used as a synthetic extracellular matrix for hepatocyte culture. The albumin synthesis, nucleus numbers and morphology of the hepatocytes were determined separately to evaluate the hepatocyte number and hepatocyte-specific function under this system. The benefits of the HGF/heparin-immobilized collagen system for hepatocyte culture were confirmed by three types of culture methods in vitro, namely 2D film cultures, 2D gel cultures and 3D gel cultures. In 2D collagen film cultures, hepatocytes exhibited the highest albumin synthesis (1.42 μg/well/day) in HGF/heparin-immobilized collagen films at 7 days of culture. Heparin inhibited hepatocyte adhesion while HGF promoted hepatocyte migration, and spheroid formation was easily detected in HGF/heparin-immobilized collagen films. In 2D collagen gel cultures, albumin synthesis of around 15 μg/well/day was detected and maintained for more than 18 days on HGF/heparin-immobilized collagen gels. Similar findings were obtained in 3D HGF/heparin-immobilized collagen gel cultures, which exhibited albumin synthesis of up to 30 μg/well/day. The albumin synthesis by hepatocytes was two-fold higher in 3D gel cultures compared with 2D gel cultures, and was maintained for over 2 weeks compared with 2D film cultures using the HGF/heparin-immobilized collagen system. Taken together, the HGF/heparin-immobilized collagen system was effective for albumin synthesis by hepatocytes in both 2D film cultures and 3D gel cultures, and therefore shows good potential for tissue engineering use.     

The Interplay between HGF/c-met Axis and Nox4 in BRAF Mutated Melanoma

Background: Melanoma is the leading cause of death due to cutaneous malignancy and its incidence is on the rise. Several signaling pathways, including receptor tyrosine kinases, have a role in the development and progression of melanocytic lesions and malignant melanoma. Among those, the hepatocyte growth factor (HGF)/c-met axis is emerging as a critical player because it can play a role in drug resistance. Indeed, 50% of melanoma patients present BRAF mutations, however, all responders develop resistance to the inhibitors typically within one year of treatment. Interestingly, BRAF inhibitors induce reactive oxygen species (ROS) in melanoma cells, therefore, the aim of this study was to investigate a possible interplay between HGF/c-met and ROS sources, such as NADPH oxidases (Nox). Methods: The expression of c-met and Nox were quantified in 60 patients with primary cutaneous melanoma. In vitro experiments on melanoma primary cells and the cell line were performed to dissect the underpinned molecular mechanism. Results: The outcome of interest was the correlation between the high positivity for both Nox4 and c-met and metastasis occurring at least 1 year later than melanoma diagnosis in BRAF mutated patients, in contrast to nonmutated. In vitro experiments demonstrated that the axis HGF/c-met/Nox4/ROS triggers the epithelial-mesenchymal transition. Conclusions: The observed correlation suggests an interplay between c-met and Nox4 in promoting the onset of metastasis. This study suggests that Nox4 inhibitors could be associated to the current therapy used to treat melanoma patients with BRAF mutations.     

Role of growth factors and their receptors in gastric ulcer healing

The repair of gastric ulcers requires the reconstitution of epithelial structures and the underlying connective tissue, including vessels and muscle layers. Several growth factors have been implicated in this process, since they are able to regulate important cell functions, such as cell proliferation, migration, differentiation, secretion, and degradation of extracellular matrix, all of which are essential during tissue healing. Epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), hepatocyte growth factor (HGF), and trefoil factors (TFFs) are mainly involved in the reconstitution of the epithelial structures. Platelet derived growth factor (PDGF), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-beta) play a major role in the reconstitution of connective tissue, including vessels and smooth muscle cells, and provide the extracellular matrix substrate for cell migration and differentiation. The expression of these growth factors and their receptors is increased during ulcer healing and, in some cases, intracellular signaling related to receptor binding and transduction has been demonstrated. EGF, TGF-alpha and TFFs are normally present either in the gastric juice or in the mucosa, and may exert their effects immediately after damage, before newly synthesized EGF and TFFs are released from the ulcer margin. The inhibition of their effects by neutralizing antibodies may result in delayed ulcer healing, while the administration of recombinant or natural analogues may improve ulcer repair. In this review, we will summarize the basic molecular characteristics of some of these growth factors, and will discuss available evidence supporting their role in the ulcer repair process.     

Toward the biomimetic implant surface: Biopolymers on titanium-based implants for bone regeneration

Replacing malfunctioning tissues with titanium-based implants has become a widespread practice spurred by population aging. Advances in biomaterials, technology and implantation protocols have led to increasing expectations on the applicability and durability of implants. The field has recently moved from a bioinert to a bioactive paradigm due to surface modifications that trigger specific responses on the surrounding tissues. Biopolymeric surface coatings have taken up a central role in these developments. The use of these and other biomimetic strategies on implants provides greater control over material–cell interactions and it is aimed at improving long-term clinical results by replicating some of the structures and mechanisms of living tissues. This review summarizes the state of the art of biomimetic implants and discusses the main directions and challenges of this field toward a more predictable and successful implant osseointegration.     

酒精浓醪发酵联产乳酸化饲料新工艺

以玉米为原料,耐高温耐高酒精度的活性干酵母为发酵剂进行浓醪酒精发酵实验,对糖化发酵工艺过程中酒精度、总糖、还原糖、酸度以及CO2失重等指标的过程变化进行了研究.并利用一株嗜酸乳酸杆菌,以酒糟为基质进行酒糟混合料的乳酸发酵实验.结果表明玉米原料经酒精浓醪发酵60 h后,玉米发酵醪中酒精体积分数达12.8%,残总糖质量分数为3.46%,残还原糖质量分数为0.19%,淀粉利用率89.88%以上.酒糟混合料接种乳酸菌,33 ℃条件下发酵15 d,发酵后酒糟混合料水分质量分数为53%,粗蛋白质量分数18.62%,粗脂肪质量分数3.32%,粗纤维质量分数3.95%,17种氨基酸质量分数达18.3%;乳酸质量分数1.93%,每克酒糟发酵料含乳酸菌菌数为4.2×107个,达到所设计乳酸菌菌数的要求.     

木瓜提取物对小鼠脂肪肝的保护作用

本文研究了木瓜提取物对小鼠脂肪肝的干预作用。将40只雄性昆明小鼠随机分成4组,正常组、高脂组和药物低(100mg/kg)、高(300 mg/kg)剂量组。正常组给予普通饲料,高脂组给予高脂高糖饲料,用药组采用木瓜提取物低、高剂量饲料喂养,1月后处死,检测小鼠血清相关指标,HE染色观察肝脏组织形态,RT-PCR和激光共聚焦显微镜(Confocal)检测脂代谢相关基因表达,q PCR检测mi R-199a-5p水平。与正常组相比,高脂组小鼠血清中TC、ALT的水平增高;组织病理结果显示,肝脏脂肪变性明显;RT-PCR和Confocal结果显示,HGF、VEGFa和c-Met的表达降低,q PCR显示,高脂组中mi R-199a-5p水平增高。与高脂组比较,药物低、高剂量组脂肪肝病理损伤明显改善,血清ALT、TC含量均下降,HGF、VEGFa和c-Met表达水平上调,mi R-199a-5p水平降低。因此木瓜提取物对高脂高糖诱导的小鼠脂肪肝有保护作用,其可能的机制是通过调节mi R-199a-5p-HGF/c-Met信号通路发挥作用。     

HGF-Induced PD-L1 Expression in Head and Neck Cancer: Preclinical and Clinical Findings

Head and neck squamous cell carcinoma (HNSCC) is a widespread disease with a low survival rate and a high risk of recurrence. Nowadays, immune checkpoint inhibitor (ICI) treatment is approved for HNSCC as a first-line treatment in recurrent and metastatic disease. ICI treatment yields a clear survival benefit, but overall response rates are still unsatisfactory. As shown in different cancer models, hepatocyte growth factor/mesenchymal–epithelial transition (HGF/Met) signaling contributes to an immunosuppressive microenvironment. Therefore, we investigated the relationship between HGF and programmed cell death protein 1 (PD-L1) expression in HNSCC cell lines. The preclinical data show a robust PD-L1 induction upon HGF stimulation. Further analysis revealed that the HGF-mediated upregulation of PD-L1 is MAP kinase-dependent. We then hypothesized that serum levels of HGF and soluble programmed cell death protein 1 (sPD-L1) could be potential markers of ICI treatment failure. Thus, we determined serum levels of these proteins in 20 HNSCC patients before ICI treatment and correlated them with treatment outcomes. Importantly, the clinical data showed a positive correlation of both serum proteins (HGF and sPD-L1) in HNSCC patient’s sera. Moreover, the serum concentration of sPD-L1 was significantly higher in ICI non-responsive patients. Our findings indicate a potential role for sPD-L1 as a prognostic marker for ICI treatment in HNSCC.     

Dimer Interface in Natural Variant NK1 Is Dispensable for HGF-Dependent Met Receptor Activation

NK1, a splicing variant of hepatocyte growth factor (HGF), binds to and activates Met receptor by forming an NK1 dimer and 2:2 complex with Met. Although the structural mechanism underlying Met activation by HGF remains incompletely resolved, it has been proposed that the NK1 dimer structure participates in this activation. We investigated the NK1 dimer interface’s role in Met activation by HGF. Because N127, V140, and K144 are closely involved in the head-to-tail NK1 dimer formation, mutant NK1 proteins with replacement of these residues by alanine were prepared. In Met tyrosine phosphorylation assays, N127-NK1, V140-NK1, and K144-NK1 showed 8.3%, 23.8%, and 52.2% activity, respectively, compared with wild-type NK1. Although wild-type NK1 promoted cell migration and scattering, N127-NK1, V140-NK1, and K144-NK1 hardly or marginally promoted them, indicating loss of activity of these mutant NK1 proteins to activate Met. In contrast, mutant HGFs (N127-HGF, V140-HGF, and K144-HGF) with the same amino acid replacements as in NK1 induced Met tyrosine phosphorylation and biological responses at levels comparable to those of wild-type HGF. These results indicate that the structural basis responsible for NK1-dependent Met dimer formation and activation differs from, or is at least distinguishable from, the structural basis responsible for HGF-dependent Met activation.