Cryptococcal CNS Infections among HIV-Negative, Non-Solid Organ Transplant Patients [Meeting Abstract]
El Husseini, Nada; Bratton, Emily W; Chastain, Cody; Lee, Michael; Daras, Mariza; Roy, Lipi; Ashley, Elizabeth Dodds; Perfect, John
ISI:000288149302277
ISSN: 0028-3878
CID: 2439212
K+ channels and the microglial respiratory burst
Khanna, R; Roy, L; Zhu, X; Schlichter, L C
Microglial activation following central nervous system damage or disease often culminates in a respiratory burst that is necessary for antimicrobial function, but, paradoxically, can damage bystander cells. We show that several K+ channels are expressed and play a role in the respiratory burst of cultured rat microglia. Three pharmacologically separable K+ currents had properties of Kv1.3 and the Ca2+/calmodulin-gated channels, SK2, SK3, and SK4. mRNA was detected for Kv1.3, Kv1.5, SK2, and/or SK3, and SK4. Protein was detected for Kv1.3, Kv1.5, and SK3 (selective SK2 and SK4 antibodies not available). No Kv1.5-like current was detected, and confocal immunofluorescence showed the protein to be subcellular, in contrast to the robust membrane localization of Kv1.3. To determine whether any of these channels play a role in microglial activation, a respiratory burst was stimulated with phorbol 12-myristate 13-acetate and measured using a single cell, fluorescence-based dihydrorhodamine 123 assay. The respiratory burst was markedly inhibited by blockers of SK2 (apamin) and SK4 channels (clotrimazole and charybdotoxin), and to a lesser extent, by the potent Kv1.3 blocker agitoxin-2.
PMID: 11245596
ISSN: 0363-6143
CID: 5121782