CACNA1H is expressed in human adrenal glomerulosa
If the CACNA1HM1549V mutation causes early-onset PA, CACNA1H (CaV3.2) should be expressed in human adrenal glomerulosa. CACNA1H transcripts have previously been reported in human kidney, liver, heart and brain (Cribbs et al., 1998), and our prior analysis of gene expression of human adrenal cortex showed that CACNA1H was the second most highly expressed calcium channel alpha subunit, after CACNA1D (Scholl et al., 2013). We performed immunohistochemistry with two different antibodies specific for the encoded channel protein (CaV3.2), demonstrating strong staining of human adrenal glomerulosa; this staining was abolished after preincubation with immunogenic peptide (Figure 3). These results are consistent with prior in situ hybridization and electrophysiological studies of rodent and bovine glomerulosa (Schrier et al., 2001; Hu et al., 2012) as well as a recent study of human adrenal gland (Felizola et al., 2014).
10.7554/eLife.06315.008Figure 3. Immunohistochemistry of CaV3.2 in normal human adrenal gland.
Sections of normal human adrenal are shown. C denotes adrenal capsule; G, glomerulosa; F, fasciculata. (A) Normal adrenal gland stained with hematoxylin and an antibody to CaV3.2 (Alomone). (B) Higher power image of adrenal in panel (A). (C, D) Absence of staining after preincubation of the antibody with the antigenic peptide, demonstrating specificity. (E) A second normal human adrenal gland stained for CACNA1H as in (A, B). (F) Gland from (A–D) stained with a second α-CACNA1H antibody (Santa Cruz). Scale bars, 100 μm (A, C); 50 μm (B, D, E, F). The results demonstrate expression of CaV3.2 in the normal zona glomerulosa, which is only several cells in depth.
DOI: http://dx.doi.org/10.7554/eLife.06315.008