Calcium fluxes in human trophoblast (BeWo) cells: calcium channels,calcium-ATPase,and sodium-calcium exchanger expression

Although placental transfer of maternal calcium (Ca(2+)) is a crucial process for fetal development, the biochemical mechanisms are poorly understood. In the current study, we have investigated the characteristics of Ca(2+) fluxes in relation with cell Ca(2+) homeostasis in the human placental trophoblast cell line BeWo. Time-courses of Ca(2+) uptake by BeWo cells displayed rapid initial entry (initial velocity (V(i)) of 3.42 +/- 0.35 nmol/mg protein/min) and subsequent establishment of a plateau. Ca(2+) efflux studies with (45)Ca(2+)-loaded cells also showed rapid declined of cell-associated (45)Ca(2+) with a V(i) of efflux (Ve(i)) of 3.30 +/- 0.08 nmol/mg protein/min. Further identification of membrane gates for Ca(2+) entry in BeWo cells was carried out. Expression of Ca(2+) transporter/channel CaT1 and L-type alpha(1S) subunit was showed by RT-PCR. However, mRNA for CaT2 channel and L-type alpha(1C) and alpha(1D) subunits were not revealed. Membrane systems responsible for intracellular Ca(2+) extrusion from BeWo cells were also investigated. Plasma membrane Ca(2+)-ATPases (PMCA) and Na/Ca exchangers (NCX) were detected by Western blot in BeWo cells. Expression of specific isoforms of PMCA and NCX was further investigated by RT-PCR. Messenger RNAs of four isoforms of PMCA (PMCA 1-4) were detected. The presence of messenger RNAs of two NCX isoforms (NCX1 and NCX3) was observed. Ca(2+) flux studies in Na-free incubation medium indicated that NCX played a minimal role in the cell Ca(2+) fluxes. Inorganic ions such as cadmium and manganese did not modify the Ca(2+) fluxes, however, barium increased cell-associated (45)Ca(2+) by, in part, by reducing radiolabel exit.     

Increased capillarity in leg muscle of finches living at altitude

An increased ratio of muscle capillary tofiber number (capillary/fiber number) at altitude has been found inonly a few investigations. The highly aerobic pectoralismuscle of finches living at 4,000-m altitude(Leucosticte arctoa; A) was recentlyshown to have a larger capillary/fiber number and greater contributionof tortuosity and branching to total capillary length than sea-levelfinches (Carpodacus mexicanus; SL) ofthe same subfamily (O. Mathieu-Costello, P. J. Agey, L. Wu, J. M. Szewczak, and R. E. MacMillen. Respir. Physiol. 111: 189-199, 1998). To evaluate the roleof muscle aerobic capacity on this trait, we examined the less-aerobicleg muscle (deep portion of anterior thigh) in the same birds. We foundthat, similar to pectoralis, the leg muscle in A finches had a greater capillary/fiber number (1.42 ± 0.06) than that in SLfinches (0.77 ± 0.05; P < 0.01),but capillary tortuosity and branching were not different. As alsofound in pectoralis, the resulting larger capillary/fiber surface in Afinches was proportional to a greater mitochondrial volume permicrometer of fiber length compared with that in SL finches. Theseobservations, in conjunction with a trend to a greater (rather thansmaller) fiber cross-sectional area in A than in SL finches (A: 484 ± 42, SL: 390 ± 26 µm²,both values at 2.5-µm sarcomere length;P = 0.093), support the notion thatchronic hypoxia is also a condition in which capillary-to-fiber structure is organized to match the size of the musclecapillary-to-fiber interface to fiber mitochondrial volume rather thanto minimize intercapillary O₂diffusion distances.

     

IL22/IL-22R Pathway Induces Cell Survival in Human Glioblastoma Cells

Interleukin-22 (IL-22) is a member of the IL-10 cytokine family that binds to a heterodimeric receptor consisting of IL-22 receptor 1 (IL-22R1) and IL-10R2. IL-22R expression was initially characterized on epithelial cells, and plays an essential role in a number of inflammatory diseases. Recently, a functional receptor was detected on cancer cells such as hepatocarcinoma and lung carcinoma, but its presence was not reported in glioblastoma (GBM). Two GBM cell lines and 10 primary cell lines established from patients undergoing surgery for malignant GBM were used to investigate the expression of IL-22 and IL-22R by using quantitative RT-PCR, western blotting and confocal microscopy studies. The role of IL-22 in proliferation and survival of GBM cell lines was investigated in vitro by BrdU and ELISA cell death assays. We report herein that the two subunits of the IL-22R complex are expressed on human GBM cells. Their activation, depending on exogenous IL-22, induced antiapoptotic effect and cell proliferation. IL-22 treatment of GBM cells resulted in increased levels of phosphorylated Akt, STAT3 signaling protein and its downstream antiapoptotic protein Bcl-xL and decreased level of phosphorylated ERK1/2. In addition, IL-22R subunits were expressed in all the 10 tested primary cell lines established from GBM tumors. Our results showed that IL-22R is expressed on GBM established and primary cell lines. Depending on STAT3, ERK1/2 and PI3K/Akt pathways, IL-22 induced GBM cell survival. These data are consistent with a potential role of IL-22R in tumorigenesis of GBM. Since endogenous IL-22 was not detected in all studied GBM cells, we hypothesize that IL-22R could be activated by immune microenvironmental IL-22 producing cells.     

Neurite growth acceleration of adult Dorsal Root Ganglion neurons illuminated by low‐level Light Emitting Diode light at 645 nm

The effect of a 645 nm Light Emitting Diode (LED) light irradiation on the neurite growth velocity of adult Dorsal Root Ganglion (DRG) neurons with peripheral axon injury 4–10 days before plating and without previous injury was investigated. The real amount of light reaching the neurons was calculated by taking into account the optical characteristics of the light source and of media in the light path. The knowledge of these parameters is essential to be able to compare results of the literature and a way to reduce inconsistencies. We found that 4 min irradiation of a mean irradiance of 11.3 mW/cm² (corresponding to an actual irradiance reaching the neurons of 83 mW/cm²) induced a 1.6‐fold neurite growth acceleration on non‐injured neurons and on axotomized neurons. Although the axotomized neurons were naturally already in a rapid regeneration process, an enhancement was found to occur while irradiating with the LED light, which may be promising for therapy applications.

Dorsal Root Ganglion neurons ( A ) without previous injury and ( B ) subjected to a conditioning injury.     

Cellular Responses Modulated by FGF-2 Adsorbed on Albumin/Heparin Layer-by-Layer Assemblies

In a typical cell culture system, growth factors immobilized on the cell culture surfaces can serve as a reservoir of bio-signaling molecules, without the need to supplement them additionally into the culture medium. In this paper, we report on the fabrication of albumin/heparin (Alb/Hep) assemblies for controlled binding of basic fibroblast growth factor (FGF-2). The surfaces were constructed by layer-by-layer adsorption of polyelectrolytes albumin and heparin and were subsequently stabilized by covalent crosslinking with glutaraldehyde. An analysis of the surface morphology by atomic force microscopy showed that two Alb/Hep bilayers are required to cover the surface of substrate. The formation of the Alb/Hep assemblies was monitored by the surface plasmon resonance (SPR), the infrared multiinternal reflection spectroscopy (FTIR MIRS) and UV/VIS spectroscopy. The adsorption of FGF-2 on the cross-linked Alb/Hep was followed by SPR. The results revealed that FGF-2 binds to the Alb/Hep assembly in a dose and time-dependent manner up to the surface concentration of 120 ng/cm². The bioactivity of the adsorbed FGF-2 was assessed in experiments in vitro, using calf pulmonary arterial endothelial cells (CPAE). CPAE cells could attach and proliferate on Alb/Hep surfaces. The adsorbed FGF-2 was bioactive and stimulated both the proliferation and the differentiation of CPAE cells. The improvement was more pronounced at a lower FGF-2 surface concentration (30 ng/cm²) than on surfaces with a higher concentration of FGF-2 (120 ng/cm²).     

Mutation in the Drosophila melanogaster adenosine receptor gene selectively decreases the mosaic hyperplastic epithelial outgrowth rates in wts or dco heterozygous flies

Adenosine (Ado) is a ubiquitous metabolite that plays a prominent role as a paracrine homeostatic signal of metabolic imbalance within tissues. It quickly responds to various stress stimuli by adjusting energy metabolism and influencing cell growth and survival. Ado is also released by dead or dying cells and is present at significant concentrations in solid tumors. Ado signaling is mediated by Ado receptors (AdoR) and proteins modulating its concentration, including nucleoside transporters and Ado deaminases. We examined the impact of genetic manipulations of three Drosophila genes involved in Ado signaling on the incidence of somatic mosaic clones formed by the loss of heterozygosity (LOH) of tumor suppressor and marker genes. We show here that genetic manipulations with the AdoR, equilibrative nucleoside transporter 2 (Ent2), and Ado deaminase growth factor-A (Adgf-A) cause dramatic changes in the frequency of hyperplastic outgrowth clones formed by LOH of the warts (wts) tumor suppressor, while they have almost no effect on control yellow (y) clones. In addition, the effect of AdoR is dose-sensitive and its overexpression leads to the increase in wts hyperplastic epithelial outgrowth rates. Consistently, the frequency of mosaic hyperplastic outgrowth clones generated by the LOH of another tumor suppressor, discs overgrown (dco), belonging to the wts signaling pathway is also dependent on AdoR. Our results provide interesting insight into the maintenance of tissue homeostasis at a cellular level.

Electronic supplementary material

The online version of this article (doi:10.1007/s11302-014-9435-2) contains supplementary material, which is available to authorized users.     

A Systematic Critical Appraisal of Clinical Practice Guidelines in Juvenile Idiopathic Arthritis Using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) Instrument

Objectives

The objectives of this review are to: 1) appraise the methodological quality of clinical practice guidelines (CPGs) in juvenile idiopathic arthritis (JIA) providing pharmacological and/or non-pharmacological intervention recommendations, and 2) summarize the recommendations provided by the included CPGs and compare them where possible.

Methods

A systematic search was performed. Three trained appraisers independently evaluated the methodological quality of the CPGs using a validated and reliable instrument, the Appraisal of Guidelines in Research and Evaluation II. Six domains were considered: 1) score and purpose; 2) stakeholder involvement; 3) rigor of development; 4) clarity of presentation; 5) applicability; and 6) editorial independence. The domains consist of a total of 23 items each scored on a 7-point scale. High quality CPGs were identified if they had a domain score above 60% in rigor of development, and two other domains.

Results

Of the three included CPGs, the Royal Australian College of General Practitioners (RACGP) and American College of Rheumatology (ACR) CPGs were considered to be of high quality, but the German Society for Pediatric Rheumatology was of lower quality. Domains one to four had high domain scores across the guidelines (mean (standard deviation)): 72.76 (13.80); 66.67 (9.81); 64.67 (7.77); and 87.00 (9.64), respectively. Lower scores were obtained for applicability (14.00 (5.57)) and editorial independence (43.44 (7.02)). Recommendations varied across CPGs due to differences in context, target audience (general practitioners, rheumatologists, and other multidisciplinary healthcare professionals) and patients’ disease presentations. Despite this variability, progression of pharmacological treatment did not conflict between CPGs. Recommendations for non-pharmacological interventions were vague and the interventions considered varied between CPGs.

Conclusions

Overall, recommendations were based on a paucity of evidence and weak study designs. Further research is needed on interventions in JIA, as well as higher quality CPGs to facilitate implementation of the best evidence-based recommendations in clinical practice.