PMID- 12761243
OWN - NLM
STAT- MEDLINE
DCOM- 20030820
LR  - 20191210
IS  - 1046-6673 (Print)
IS  - 1046-6673 (Linking)
VI  - 14
IP  - 6
DP  - 2003 Jun
TI  - Cyclosporine A amplifies Ca2+ signaling pathway in LLC-PK1 cells through the 
      inhibition of plasma membrane Ca2+ pump.
PG  - 1435-42
AB  - Cyclosporine A (CsA), a neutral, highly hydrophobic cyclic peptide with 11 amino 
      acids, is currently the most widely used immunosuppressive drug for preventing 
      graft rejection and autoimmune diseases. Despite its efficacy, the use of CsA is 
      limited by severe side effects, mainly nephrotoxicity and arterial hypertension. 
      Single cell microfluorimetry was used to evaluate the role of CsA on Ca(2+) 
      signaling pathway in intact cells of the porcine proximal tubule-like cell line 
      LLC-PK1; the assay of the in vitro activity of the plasma membrane Ca(2+) pump 
      (PMCA) was carried out through the preparation and isolation of membranes. The 
      addition of CsA to incubation medium at doses ranging from 0.1 to 2 microM did 
      not change the basal level of intracellular calcium ([Ca(2+)](i)), whereas it 
      affected the [Ca(2+)](i) response to thapsigargin (TG), a powerful inhibitor of 
      microsomal Ca(2+) pump. In control studies, 5 microM TG produced a biphasic 
      response: [Ca(2+)](i) peaked with a 60-s lag, and it then declined to a plateau 
      of elevated [Ca(2+)](i), which remains above basal. However, it became evident 
      that CsA strengthened the Ca(2+) response to TG because the addition of 5 microM 
      TG to cells exposed to 400 nM CsA did not affect the peak response to TG, but it 
      markedly affected the subsequent sustained phase ([Ca(2+)](i) = 156 +/- 4.84 
      versus 130 +/- 3.28 nmol, mean +/- SEM, n = 6, P < 0.001). In membrane 
      preparations, 200 nM CsA brought about, in the presence of 10 microM calmodulin 
      (CaM), a significant decrease of plasma membrane Ca(2+) pump (PMCA) activity 
      (46.96 +/- 0.26 versus 53.48 +/- 1.96 nmol x mg of protein(-1) x min(-1), n = 6, 
      P < 0.02), a value similar to that obtained in the presence of equimolar amounts 
      of cyclosporine H (CsH), a non-immunosuppressive analogue of CsA. These findings 
      suggest that in this cell line CsA affects the Ca(2+) export pathway through the 
      reduction of the PMCA activity with consequent amplification and strengthening of 
      [Ca(2+)](i) response after exposure to agents that trigger intracellular Ca(2+) 
      release. The increased cell sensitivity during Ca(2+) signaling events ensuing 
      from the impairment of this "defense system" may be regarded as one of the basic 
      mechanisms involved in the development of the side effects induced by CsA.
FAU - Calderaro, Vincenzo
AU  - Calderaro V
AD  - Institute of Internal Medicine and Nephrology, Second University of Naples, 
      Naples, Italy. vincenzo.calderaro@unina2.it
FAU - Boccellino, Mariarosaria
AU  - Boccellino M
FAU - Cirillo, Giovanni
AU  - Cirillo G
FAU - Quagliuolo, Lucio
AU  - Quagliuolo L
FAU - Cirillo, Domenico
AU  - Cirillo D
FAU - Giovane, Alfonso
AU  - Giovane A
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Am Soc Nephrol
JT  - Journal of the American Society of Nephrology : JASN
JID - 9013836
RN  - 0 (Calmodulin)
RN  - 0 (Enzyme Inhibitors)
RN  - 67526-95-8 (Thapsigargin)
RN  - 83HN0GTJ6D (Cyclosporine)
RN  - EC 7.2.2.10 (Calcium-Transporting ATPases)
RN  - FUO6O3NDNH (cyclosporin H)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Calcium/*metabolism
MH  - Calcium-Transporting ATPases/*antagonists & inhibitors
MH  - Calmodulin/pharmacology
MH  - Cell Membrane/metabolism
MH  - Cyclosporine/*pharmacology
MH  - Drug Synergism
MH  - Enzyme Inhibitors/*pharmacology
MH  - Intracellular Membranes/metabolism
MH  - LLC-PK1 Cells
MH  - Osmolar Concentration
MH  - Signal Transduction/*drug effects
MH  - Swine
MH  - Thapsigargin/pharmacology
EDAT- 2003/05/23 05:00
MHDA- 2003/08/21 05:00
CRDT- 2003/05/23 05:00
PHST- 2003/05/23 05:00 [pubmed]
PHST- 2003/08/21 05:00 [medline]
PHST- 2003/05/23 05:00 [entrez]
AID - 10.1097/01.asn.0000065632.32856.4c [doi]
PST - ppublish
SO  - J Am Soc Nephrol. 2003 Jun;14(6):1435-42. doi: 
      10.1097/01.asn.0000065632.32856.4c.