Avtor/Urednik		Stenovec, M; Milošević, M; Petrušić, V; Potokar, M; Stević, Z; Prebil, M; Kreft, M; Trkov, S; Andjus, PR; Zorec, R
Naslov		Amyotrophic lateral sclerosis immunoglobulins G enhance the mobility of Lysotracker-labelled vesicles in cultured rat astrocytes
Tip		članek
Vir		Acta Physiol (Oxf)
Vol. in št.		Letnik 203, št. 4
Leto izdaje		2011
Obseg		str. 457-71
Jezik		eng
Abstrakt		Aim: We examined the effect of purified immunoglobulins G (IgG) from patients with amyotrophic lateral sclerosis (ALS) on the mobility and exocytotic release from Lysotracker-stained vesicles in cultured rat astrocytes. Methods: Time-lapse confocal images were acquired, and vesicle mobility was analysed before and after the application of ALS IgG. The vesicle counts were obtained to assess cargo exocytosis from stained organelles. Results: At rest, when mobility was monitored for 2 min in bath with Ca(2+) , two vesicle populations were discovered: (1) non-mobile vesicles (6.1%) with total track length (TL) < 1 mum, averaging at 0.33 +/- 0.01 mum (n = 1305) and (2) mobile vesicles (93.9%) with TL > 1 mum, averaging at 3.03 +/- 0.01 mum (n = 20 200). ALS IgG (0.1 mg mL(-1) ) from 12 of 13 patients increased the TL of mobile vesicles by approx. 24% and maximal displacement (MD) by approx. 26% within 4 min, while the IgG from control group did not alter the vesicle mobility. The mobility enhancement by ALS IgG was reduced in extracellular solution devoid of Ca(2+) , indicating that ALS IgG vesicle mobility enhancement involves changes in Ca(2+) homeostasis. To examine whether enhanced mobility relates to elevated Ca(2+) activity, cells were stimulated by 1 mm ATP, a cytosolic Ca(2+) increasing agent, in the presence (2 mm) and in the absence of extracellular Ca(2+) . ATP stimulation triggered an increase in TL by approx. 7% and 12% and a decrease in MD by approx. 11% and 1%, within 4 min respectively. Interestingly, none of the stimuli triggered the release of vesicle cargo. Conclusion: Amyotrophic lateral sclerosis-IgG-enhanced vesicle mobility in astrocytes engages changes in calcium homeostasis.
Deskriptorji		AMYOTROPHIC LATERAL SCLEROSIS IGG ASTROCYTES ENDOSOMES CELLS, CULTURED EXOCYTOSIS LYSOSOMES MICROSCOPY, CONFOCAL RATS