Autophagosomes,phagosomes, autolysosomes,phagolysosomes, autophagolysosomes… Wait,I’m confused

When an autophagosome or an amphisome fuse with a lysosome, the resulting compartment is referred to as an autolysosome. Some people writing papers on the topic of autophagy use the terms “autolysosome” and “autophagolysosome” interchangeably. We contend that these words should be used to denote 2 different compartments, and that it is worthwhile maintaining this distinction—the autophagolysosome has a particular origin in the process of xenophagy that makes it distinct from an autolysosome.     

Autophagosomes,phagosomes, autolysosomes,phagolysosomes, autophagolysosomes… Wait,I’m confused

When an autophagosome or an amphisome fuse with a lysosome, the resulting compartment is referred to as an autolysosome. Some people writing papers on the topic of autophagy use the terms “autolysosome” and “autophagolysosome” interchangeably. We contend that these words should be used to denote 2 different compartments, and that it is worthwhile maintaining this distinction—the autophagolysosome has a particular origin in the process of xenophagy that makes it distinct from an autolysosome.     

Der Mengen- und Spurenelementgehalt des Rinderhaares als Indikator der Calcium-, Magnesium-, Phosphor-, Kalium-, Natrium-, Eisen-, Zink-, Mangan-, Kupfer-, Molybdän- und Kobaltversorgung

Many health effects can be attributed to the Mediterranean herb oregano (Origanum vulgare L.) and several studies demonstrated the improving effect on performance, changes in blood count, antibacterial, antifungal and immunmodulating abilities. The majority of these investigations were carried out with processed essential oil, while whole plant material was only used in a few studies. Thus, the aim of the present experiment was to test the effect of increasing proportions of dried oregano in piglet feed on health and performance, with a special focus on immune modulation. A total of 80 male castrated weaned piglets (body weight [BW] 7.9 kg ±1.0 kg) were used in a feeding experiment lasting 5 weeks. They were assigned to 4 experimental groups: a control diet, and three diets with an oregano supplementation at 2 g, 4 g and 8 g per kg feed, respectively, corresponding to 23.5 mg, 46.9 mg and 93.9 mg carvacrol/kg DM. After 3 weeks, half of each group was challenged with 5 µg lipopolysaccharides (LPS) per kg BW. Blood samples were collected 2 h after LPS stimulation and analysed for T-cell phenotypes, granulocyte activity, clinical-chemistry as well as white and red blood count. The results indicate no effects of oregano on performance. In contrast, oregano altered the lymphocyte proportion and the ratio of CD4⁺ and CD8⁺ T-cells as well as the triglyceride concentration in the serum of non-stimulated and in LPS-stimulated piglets. In conclusion, whole plant supplementation of oregano to piglet feed altered immune-related parameters, but did not modulate the acute inflammatory response induced by LPS stimulation.     

Der Einfluß endogener Faktoren auf den Asche-, Kalzium-, Magnesium-, Kalium-, Natrium-, Phosphor-, Zink-, Eisen-, Kupfer- und Mangangehalt der Schweineborste

The objective of the present study was to investigate physiological effects of a marginal copper and iron supply on pigs. Therefore an experiment was conducted with 4 × 12 growing pigs of the crossbreed Pietrain × Deutsche Landrasse. The animals were fed for a period of 119 days with a diet poor of copper (1.5 mg Cu/kg diet) and/or poor of iron (35 mg Fe/kg diet). Control animals were supplied adequately with copper (4.8 mg Cu/kg diet) and iron (85 mg Fe/kg diet). The diet was given according to weight. After reaching an average weight of 102.6 ± 3.5 kg the animals were slaughtered. Due to the activity of the coerulplasmin and katalase enzyme and the haematological parameters, the supply of copper and iron could be classified as marginal. There was no interaction between copper deficiency and iron metabolism. The protein metabolism was unchanged. Low copper intake reduced the copper concentrations in serum, liver, muscle and backfat, and low iron intake reduced the iron concentration in serum, liver and muscle. Marginal copper and iron supply had no relevant effect on either food intake and growth performance or carcass characteristics and meat quality.     

Der Mengen- und Spurenelementgehalt des Rinderhaares als Indikator der Calcium-, Magnesium-, Phosphor-, Kalium-, Natrium-, Eisen-, Zink-, Mangan-, Kupfer-, Molybdän- und Kobaltversorgung

Beyond the energy requirement of maintenance, the assimilated energy, occurring in bioproducts, is linearly proportional to the intake of metabolizable energy in non‐underfed conditions. In contrast, resting metabolic rate is differing between individuals within a population of an animal species. As adaptability to changed environmental conditions may play a role, young bulls were exposed to thermoneutral (18°C) and low (4°C) ambient temperatures and were fed at two feeding levels (1.0 and 1.6 times energy requirement in maintenance) to produce metabolic rate differences, using the same animals, metabolic rate was altered by reducing the sympathetic outflow in each case. Expression of sulfonylurea receptors in circulating mononuclear leukocytes and cells from skeletal muscle (m. semitendinosus) was studied by flow cytom‐etry. Changes of metabolic rate at rest corresponded to the portion of cells with sulfonylurea receptors expression. The data from reducing the sympathetic outflow and those from sulfonylurea receptors expression are useful to explain metabolic rate differences among individuals of an animal population.     

Barley—Botany,production, harvesting,processing, utilization and economics

Barley, probably the oldest cultivated cereal, is widely grown in cooler areas of the world. The annual world production of nearly two and a half billion bushels exceeds that of rye but is less than that of rice, wheat, corn and oats, respectively. Most of the annual 300 million dollar crop of the U.S. is fed to livestock, but about one- third is manufactured into malt.     

胸怀祖国, 忘我工作, 为国争光

刘以训教授是我国著名的生物学家,中国科学院院士。他致力于生殖生物学研究,在排卵、黄体萎缩、精子发生和胚胎植入等系列研究上,成绩卓著,享有国际声誉。读罢此文,钦敬之情油然而生。     

The Seven Carbohydrate Bioengineering Meeting,Braunschweig, Germany,April, 22–25, 2007

Stereocontrol in bakers' yeast reduction can be achieved by introduction of a sulfur functional group into substrates. α-Methylthio-β-keto esters are reduced to give exclusively (3S)-3-hydroxy esters. α-Substituted β-keto thiol esters and dithioesters afford (2R,3S)-3-hydroxy esters with high diastereo-and enantioselectivity. Ketones possessing 1,3-dithiane, phenylsulfenyl, or phenylsulfonyl groups at the α-position are transformed also into the corresponding (S)-secondary alcohols. Optically pure (S)-(phenylsulfinyl)acetones can be obtained by kinetic resolution of racemic derivatives with the yeast. Diastereo- and enantioselective reduction of 1,2-diketones leading into (1S,2S)-1,2-diol derivatives can be also achieved by introduction of 1,3-dithiane, phenylsulfenyl or phenylsulfonyl groups into the α-position. Reductions of carbon-carbon double bond of sulfur-functionalized prenyl derivatives provide both chiral (R)- and (S)-C₅-building blocks for terpenoid synthesis. The utility of the reduction products as chiral building blocks is demonstrated in the synthesis of biologically active natural products such as pheromones, sugars, antibiotics etc. by functional group transformation and carbon-carbon bond formation reactions with the aid of sulfur functional groups.     

Stromal cell-derived factor-1 (SDF-1)\CXCR4 couple plays multiple roles on haematopoietic progenitors at the border between the old cytokine and new chemokine worlds: survival, cell cycling and trafficking

Generation of haematopoietic cells is regulated by cellular and humoral interactions in which stromal cells, adhesion molecules, cytokines and chemokines play a crucial role. Among the chemokines, SDF-1 and its CXCR4 receptor have been reported to be key players in the nesting of haematopoietic progenitors within the bone marrow. Disruption of the SDF-1\CXCR4 axis results in cell mobilization and may participate in leukaemia extramedullary infiltration. In this review we will discuss the manifold roles of the SDF-1 chemokine and of its receptor in haematopoiesis regulation. By recruiting quiescent progenitors, by participating in their survival\cycling and by sensitizing them to further cytokine synergistic action, SDF-1 likely contributes to haematopoiesis homeostasis under physiological conditions and in stress situations. The complexity of the SDF-1\CXCR4 interactions in the regulation of haematopoiesis illustrates a dynamic and sequential cross-talk between chemokine and cytokine\growth factor worlds. Because of their pleiotropic effects on haematopoietic progenitor trafficking, survival and proliferation, the SDF-1\CXCR4 couple could be considered as promising molecules for improvement of cell-based therapy protocols in haematopoietic transplantation.     

SDF-1 alone and in co-operation with HGF regulates biology of human cervical carcinoma cells

Stromal Derived Factor-1 (SDF-1)-CXCR4 axis plays a pivotal role in biology and metastasis of several tumors. The aim of this study was to see if SDF-1 alone or in combination with Hepatocyte Growth Factor (HGF) affects biology of human cervical carcinoma (HCC) cells. We found that HCC cell lines investigated in our study highly express CXCR4 on their surface. CXCR4 was also expressed on tumor cells in tissue sections derived from cervical cancer patients. At the same time normal cervical epithelium was negative for CXCR4 expression what suggests a strong correlation between CXCR4 and malignant cell phenotype. Subsequently, we studied a potential role of the SDF-1-CXCR4 axis in HCC and noticed that SDF-1 (i) chemoattracted HCC cells, (ii) enhanced their scattering, (iii) stimulated nuclear localization of beta-catenins and upregulated their target gene cyclin D1 and (iv) at the molecular level induced calcium flux and activated RAS-MAPK, PI3-AKT and JAK-STAT pathways. SDF-1-mediated functions were additionally enhanced in the presence of HGF. Thus, our data show that the SDF-1-CXCR4 axis affects biology of HCC cells. Furthermore, we postulate that this axis might become a potential target to prevent progression of cervical cancer.     

Chemokine signaling regulates sensory cell migration in zebrafish

Chemokines play an important role in the migration of a variety of cells during development. Recent investigations have begun to elucidate the importance of chemokine signaling within the developing nervous system. To better appreciate the neural function of chemokines in vivo, the role of signaling by SDF-1 through its CXCR4 receptor was analyzed in zebrafish. The SDF-1-CXCR4 expression pattern suggested that SDF-1-CXCR4 signaling was important for guiding migration by sensory cells known as the migrating primordium of the posterior lateral line. Ubiquitous induction of the ligand in transgenic embryos, antisense knockdown of the ligand or receptor, and a genetic receptor mutation all disrupted migration by the primordium. Furthermore, in embryos in which endogenous SDF-1 was knocked down, the primordium migrated towards exogenous sources of SDF-1. These data demonstrate that SDF-1 signaling mediated via CXCR4 functions as a chemoattractant for the migrating primordium and that chemokine signaling is both necessary and sufficient for directing primordium migration.     

Biological significance of chemokine receptor expression by normal human megakaryoblasts

The aim of this study was to learn more on the role of chemokines in the regulation of human megakryopoiesis. Normal human megakaryoblasts were expanded in serum-free liquid cultures and subsequently (1) phenotyped for expression of various chemokine receptors, (2) evaluated if chemokine receptors which they express are functional after stimulation by chemokines (calcium flux assay, chemotaxis, phosphorylation of MAPK-p42/44 and AKT proteins), and (3) investigated for expression and secretion of selected chemokines by employing RT-PCR and ELISA assays, respectively. In addition we also phenotyped peripheral blood platelets for expression of chemokine receptors and chemokines. We found that while human megakaryoblasts express several chemokine receptors (CXCR4, CCR6, CCR8, CCR5, CCR2 and CXCR3), CXCR4 was the only receptor detectable by FACS on human platelets. Moreover, among various chemokines tested, only SDF-1 (CXCR4 ligand) stimulated calcium flux and chemotaxis in normal human megakaryoblasts and phosphorylated MAPK-p42/44 and AKT in these cells. Although mRNAs for several chemokines were detectable by RT-PCR in normal human megakaryoblasts, only RANTES, IL-8, MCP-1 and PF-4 were found to be secreted by these cells. Finally we noticed that no chemokine tested in this study affected CFU-Meg colony formation by human CD34+ cells in serum-free cultures. We conclude that from all the chemokine receptor-chemokine axes tested, only SDF-1-CXCR4 axis was functional in assays employed in our studies, which further support the view that this axis plays a privileged role in regulating normal human megakaryopoiesis.     

Structural Basis of the Interaction between Chemokine Stromal Cell-derived Factor-1/CXCL12 and Its G-protein-coupled Receptor CXCR4

The chemokine stromal cell-derived factor-1 (SDF-1/CXCL12) and its G-protein-coupled receptor (GPCR) CXCR4 play fundamental roles in many physiological processes, and CXCR4 is a drug target for various diseases such as cancer metastasis and human immunodeficiency virus, type 1, infection. However, almost no structural information about the SDF-1-CXCR4 interaction is available, mainly because of the difficulties in expression, purification, and crystallization of CXCR4. In this study, an extensive investigation of the preparation of CXCR4 and optimization of the experimental conditions enables NMR analyses of the interaction between the full-length CXCR4 and SDF-1. We demonstrated that the binding of an extended surface on the SDF-1 β-sheet, 50-s loop, and N-loop to the CXCR4 extracellular region and that of the SDF-1 N terminus to the CXCR4 transmembrane region, which is critical for G-protein signaling, take place independently by methyl-utilizing transferred cross-saturation experiments along with the usage of the CXCR4-selective antagonist AMD3100. Furthermore, based upon the data, we conclude that the highly dynamic SDF-1 N terminus in the 1st step bound state plays a crucial role in efficiently searching the deeply buried binding pocket in the CXCR4 transmembrane region by the “fly-casting” mechanism. This is the first structural analyses of the interaction between a full-length GPCR and its chemokine, and our methodology would be applicable to other GPCR-ligand systems, for which the structural studies are still challenging.     

Transgenic expression of stromal cell-derived factor-1/CXC chemokine ligand 12 enhances myeloid progenitor cell survival/antiapoptosis in vitro in response to growth factor withdrawal and enhances myelopoiesis in vivo

Hemopoiesis is regulated in part by survival/apoptosis of hemopoietic stem/progenitor cells. Exogenously added stromal cell-derived factor-1 ((SDF-1)/CXC chemokine ligand (CXCL)12) enhances survival/antiapoptosis of myeloid progenitor cells in vitro. To further evaluate SDF-1/CXCL12 effects on progenitor cell survival, transgenic mice endogenously expressing SDF-1/CXCL12 under a Rous sarcoma virus promoter were produced. Myeloid progenitors (CFU-granulocyte-macrophage, burst-forming unit-erythroid, CFU-granulocyte-erythrocyte-megakaryocyte-monocyte) from transgenic mice were studied for in vitro survival in the context of delayed addition of growth factors. SDF-1-expressing transgenic myeloid progenitors were enhanced in survival and antiapoptosis compared with their wild-type littermate counterparts. Survival-enhancing effects were due to release of low levels of SDF-1/CXCL12 and mediated through CXCR4 and G(alpha)i proteins as determined by ELISA, an antagonist to CXCR4, Abs to CXCR4 and SDF-1, and pertussis toxin. Transgenic effects of low SDF-1/CXCR4 may be due to synergy of SDF-1/CXCL12 with other cytokines; low SDF-1/CXCL12 synergizes with low concentrations of other cytokines to enhance survival of normal mouse myeloid progenitors. Consistent with in vitro results, progenitors from SDF-1/CXCL12 transgenic mice displayed enhanced marrow and splenic myelopoiesis: greatly increased progenitor cell cycling and significant increases in progenitor cell numbers. These results substantiate survival effects of SDF-1/CXCL12, now extended to progenitors engineered to endogenously produce low levels of this cytokine, and demonstrate activity in vivo for SDF-1/CXCL12 in addition to cell trafficking.     

The role of CXCR7 on the adhesion, proliferation and angiogenesis of endothelial progenitor cells

Previous studies confirmed that stromal cell-derived factor 1 (SDF-1) was a principal regulator of retention, migration and mobilization of haematopoietic stem cells and endothelial progenitor cells (EPCs) during steady-state homeostasis and injury. CXC chemokine receptor 4 (CXCR4) has been considered as the unique receptor of SDF-1 and as the only mediator of SDF-1-induced biological effects for many years. However, recent studies found that SDF-1 could bind to not only CXCR4 but also CXC chemokine receptor 7 (CXCR7). The evidence that SDF-1 binds to the CXCR7 raises a concern how to distinguish the potential contribution of the SDF-1/CXCR7 pathway from SDF-1/CXCR4 pathway in all the processes that were previously attributed to SDF-1/CXCR4. In this study, the role of CXCR7 in EPCs was investigated in vitro. RT-PCR, Western blot and flow cytometry assay demonstrate that both CXCR4 and CXCR7 were expressed highly in EPCs. The adhesion of EPCs induced by SDF-1 was inhibited by blocking either CXCR4 or CXCR7 with their antibodies or antagonists. SDF-1 regulated the migration of EPCs via CXCR4 but not CXCR7. However, the transendothelial migration of EPCs was inhibited by either blocking of CXCR4 or CXCR7. Both CXCR7 and CXCR4 are essential for the tube formation of EPCs induced by SDF-1. These results suggested that both CXCR7 and CXCR4 are important for EPCs in response to SDF-1, indicating that CXCR7 may be another potential target molecule for angiogenesis-dependent diseases.     

CXCR4 receptor expression on human retinal pigment epithelial cells from the blood-retina barrier leads to chemokine secretion and migration in response to stromal cell-derived factor 1 alpha

Retinal pigment epithelial (RPE) cells form part of the blood-retina barrier and have recently been shown to produce various chemokines in response to proinflammatory cytokines. As the scope of chemokine action has been shown to extend beyond the regulation of leukocyte migration, we have investigated the expression of chemokine receptors on RPE cells to determine whether they could be a target for chemokine signaling. RT-PCR analysis indicated that the predominant receptor expressed on RPE cells was CXCR4. The level of CXCR4 mRNA expression, but not cell surface expression, increased on stimulation with IL-1beta or TNF-alpha. CXCR4 protein could be detected on the surface of 16% of the RPE cells using flow cytometry. Calcium mobilization in response to the CXCR4 ligand stromal cell-derived factor 1alpha (SDF-1alpha) indicated that the CXCR4 receptors were functional. Incubation with SDF-1alpha resulted in secretion of monocyte chemoattractant protein-1, IL-8, and growth-related oncogene alpha. RPE cells also migrated in response to SDF-1alpha. As SDF-1alpha expression by RPE cells was detected constitutively, we postulate that SDF-1-CXCR4 interactions may modulate the affects of chronic inflammation and subretinal neovascularization at the RPE site of the blood-retina barrier.     

The role of SDF-1-CXCR4/CXCR7 axis in the therapeutic effects of hypoxia-preconditioned mesenchymal stem cells for renal ischemia/reperfusion injury

In vitro hypoxic preconditioning (HP) of mesenchymal stem cells (MSCs) could ameliorate their viability and tissue repair capabilities after transplantation into the injured tissue through yet undefined mechanisms. There is also experimental evidence that HP enhances the expression of both stromal-derived factor-1 (SDF-1) receptors, CXCR4 and CXCR7, which are involved in migration and survival of MSCs in vitro, but little is known about their role in the in vivo therapeutic effectiveness of MSCs in renal ischemia/reperfusion (I/R) injury. Here, we evaluated the role of SDF-1-CXCR4/CXCR7 pathway in regulating chemotaxis, viability and paracrine actions of HP-MSCs in vitro and in vivo. Compared with normoxic preconditioning (NP), HP not only improved MSC chemotaxis and viability but also stimulated secretion of proangiogenic and mitogenic factors. Importantly, both CXCR4 and CXCR7 were required for the production of paracrine factors by HP-MSCs though the former was only responsible for chemotaxis while the latter was for viability. SDF-1α expression was upregulated in postischemic kidneys. After 24 h systemical administration following I/R, HP-MSCs but not NP-MSCs were selectively recruited to ischemic kidneys and this improved recruitment was abolished by neutralization of CXCR4, but not CXCR7. Furthermore, the increased recruitment of HP-MSCs was associated with enhanced functional recovery, accelerated mitogenic response, and reduced apoptotic cell death. In addition, neutralization of either CXCR4 or CXCR7 impaired the improved therapeutic potential of HP-MSCs. These results advance our knowledge about SDF-1-CXCR4/CXCR7 axis as an attractive target pathway for improving the beneficial effects of MSC-based therapies for renal I/R.