studying-organelle-dynamics-in-b-cells-during-immune-synapse-formation

Studying Organelle Dynamics in B Cells During Immune Synapse Formation

Recognition of surface-tethered antigens&#160;by the B cell receptor (BCR)&#160;triggers the formation of an immune synapse (IS), where both ...

Universidad San Sebastián

A soccer match induce changes in physiological stress biomarkers as testosterone (T), cortisol (C), and testosterone:cortisol (T:C) ration. Hydration state may also modulate these hormones, and therefore may alter the anabolic/catabolic balance in response to soccer match. The role of hydration status before the match in this biomarkers has not yet been reported. The aim of this study was to compare the salivary T, C, and the T:C ratio responses after two friendly matches in well-hydrated and mild-dehydrated (MD) elite young male soccer player. Seventeen players (age, 16.8 ± 0.4 years; VOmax 57.2 ± 3.6 ml/kg/min) were divided into two teams. Before the matches the athletes were assessed for hydration level by the urine specific gravity method and divided for the analysis into well-hydrated (WH;  = 9; USG < 1.010 g/mL) and mild-dehydrated (MD;  = 8; USG 1.010 to 1.020 g/mL) groups. Hormones were collected before and after each match by saliva samples. The mean (HRmean) and maximal (HRmax) heart rate were measured throughout the matches. A two-way ANOVA was used to compare T, C, and T:C between and within groups. Similar HRmean (WH, 83.1 ± 4.7%; MD, 87.0 ± 4.1;  = 0.12) and HRmax (WH, 93.2 ± 4.4%; MD, 94.7 ± 3.7%;  = 0.52) were found for both groups during the matches. No differences were found before the matches in the T ( = 0.38), C ( = 66), nor T:C ( = 0.38) between groups. No changes within groups were found after matches in neither group for T (WH,  = 0.20; MD,  = 0.36), and T:C (WH,  = 0.94; MD,  = 0.63). Regarding the C, only the MD group showed increases (28%) after the matches (MD,  = 0.03; WH,  = 0.13). In conclusion MD group exacerbate the C response to friendly matches in elite young male soccer players, suggesting that dehydration before match may be an added stress to be considered.

Basal Mild Dehydration Increase Salivary Cortisol After a Friendly Match in Young Elite Soccer Players.

Inter-organelle signalling has essential roles in cell physiology encompassing cell metabolism, aging and temporal adaptation to external and internal perturbations. How such signalling coordinates different organelle functions within adaptive responses remains unknown. Membrane traffic is a fundamental process in which membrane fluxes need to be sensed for the adjustment of cellular requirements and homeostasis. Studying endoplasmic reticulum-to-Golgi trafficking, we found that Golgi-based, KDEL receptor-dependent signalling promotes lysosome repositioning to the perinuclear area, involving a complex process intertwined to autophagy, lipid-droplet turnover and Golgi-mediated secretion that engages the microtubule motor protein dynein-LRB1 and the autophagy cargo receptor p62/SQSTM1. This process, here named 'traffic-induced degradation response for secretion' (TIDeRS) discloses a cellular mechanism by which nutrient and membrane sensing machineries cooperate to sustain Golgi-dependent protein secretion.

KDEL receptor regulates secretion by lysosome relocation- and autophagy-dependent modulation of lipid-droplet turnover.

Maintaining the optimal performance of cell processes and organelles is the task of auto-regulatory systems. Here we describe an auto-regulatory device that helps to maintain homeostasis of the endoplasmic reticulum (ER) by adjusting the secretory flux to the cargo load. The cargo-recruiting subunit of the coatomer protein II (COPII) coat, Sec24, doubles as a sensor of folded cargo and, upon cargo binding, acts as a guanine nucleotide exchange factor to activate the signaling protein Gα12 at the ER exit sites (ERESs). This step, in turn, activates a complex signaling network that activates and coordinates the ER export machinery and attenuates proteins synthesis, thus preventing large fluctuations of folded and potentially active cargo that could be harmful to the cell or the organism. We call this mechanism AREX (autoregulation of ER export) and expect that its identification will aid our understanding of human physiology and diseases that develop from secretory dysfunction.

Jorge Cancino

Centro de Investigaciones en Biología Celular y Biomedicina,
Facultad de Ciencia,
Centro de Investigaciones en Biología Celular y Biomedicina, Facultad de Ciencia

Universidad San Sebastián

Studying Organelle Dynamics in B Cells During Immune Synapse Formation

Jorge Cancino

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Centro de Investigaciones en Biología Celular y Biomedicina,Facultad de Ciencia,Centro de Investigaciones en Biología Celular y Biomedicina, Facultad de Ciencia

Universidad San Sebastián

Studying Organelle Dynamics in B Cells During Immune Synapse Formation

Centro de Investigaciones en Biología Celular y Biomedicina,
Facultad de Ciencia,
Centro de Investigaciones en Biología Celular y Biomedicina, Facultad de Ciencia