Altered TRPC7 gene expression in bipolar-I disorder

• Published in: Biological psychiatry (1969) 2001-10, Vol.50 (8), p.620-626
• Main Authors: Yoon, I S, Li, P P, Siu, K P, Kennedy, J L, Macciardi, F, Cooke, R G, Parikh, S V, Warsh, J J
• Format: Article
• Language: English
• Subjects: Adult; B-Lymphocytes; Bipolar Disorder - classification; Bipolar Disorder - diagnosis; Bipolar Disorder - genetics; Bipolar Disorder - psychology; Calcium - physiology; Calcium Channels - genetics; Cell Line; Depressive Disorder, Major - diagnosis; Depressive Disorder, Major - genetics; Depressive Disorder, Major - psychology; Female; Gene Expression - physiology; Homeostasis - genetics; Homeostasis - physiology; Humans; Ion Channels; Male; Membrane Proteins; Middle Aged; Reference Values; Reverse Transcriptase Polymerase Chain Reaction; TRPC Cation Channels; TRPM Cation Channels
• ISSN: 0006-3223
• DOI: 10.1016/S0006-3223(01)01077-0

As altered storage-operated calcium (Ca(2+)) entry (SOCE) may affect Ca(2+) homeostasis in bipolar disorder (BD), we determined whether changes occur in the expression of TRPC7 and SERCA2s, proteins implicated or known to be involved in SOCE, in B lymphoblast cell lines (BLCLs) from BD-I patients and comparison subjects. mRNA levels were determined in BLCL lysates from BD-I, BD-II, and major depressive disorder patients, and healthy subjects by comparative reverse transcriptase-polymerase chain reaction, and BLCL basal intracellular Ca(2+) concentration ([Ca(2+)]B) was determined by ratiometric spectrophotometry using Fura-2, in aliquots of the same cell lines, at 13-16 passages in culture. TRPC7 mRNA levels were significantly lower in BLCLs from BD-I patients with high BLCL [Ca(2+)]B compared with those showing normal [Ca(2+)]B (-33%, p =.017) and with BD-II patients (-48%, p =.003), major depressive disorder patients (-47%, p =.049) and healthy subjects (-33%, p =.038). [Ca(2+)]B also correlated inversely with TRPC7 mRNA levels in BLCLs from the BD-I group as a whole (r = -.35, p =.027). Reduced TRPC7 gene expression may be a trait associated with pathophysiological disturbances of Ca(2+) homeostasis in a subgroup of BD-I patients.