| First Author | Levit NA | Year | 2015 |
| Journal | J Invest Dermatol | Volume | 135 |
| Issue | 4 | Pages | 1033-1042 |
| PubMed ID | 25229253 | Mgi Jnum | J:219904 |
| Mgi Id | MGI:5629923 | Doi | 10.1038/jid.2014.408 |
| Citation | Levit NA, et al. (2015) Aberrant connexin26 hemichannels underlying keratitis-ichthyosis-deafness syndrome are potently inhibited by mefloquine. J Invest Dermatol 135(4):1033-42 |
| abstractText | Keratitis-ichthyosis-deafness (KID) syndrome is an ectodermal dysplasia caused by dominant mutations of connexin26 (Cx26). Loss of Cx26 function causes nonsyndromic sensorineural deafness, without consequence in the epidermis. Functional analyses have revealed that a majority of KID-causing mutations confer a novel expansion of hemichannel activity, mediated by connexin channels in a nonjunctional configuration. Inappropriate Cx26 hemichannel opening is hypothesized to compromise keratinocyte integrity and epidermal homeostasis. Pharmacological modulators of Cx26 are needed to assess the pathomechanistic involvement of hemichannels in the development of hyperkeratosis in KID syndrome. We have used electrophysiological assays to evaluate small-molecule analogs of quinine for suppressive effects on aberrant hemichannel currents elicited by KID mutations. Here, we show that mefloquine (MFQ) inhibits several mutant hemichannel forms implicated in KID syndrome when expressed in Xenopus laevis oocytes (IC50 approximately 16 muM), using an extracellular divalent cation, zinc (Zn(++)), as a nonspecific positive control for comparison (IC50 approximately 3 muM). Furthermore, we used freshly isolated transgenic keratinocytes to show that micromolar concentrations of MFQ attenuated increased macroscopic membrane currents in primary mouse keratinocytes expressing human Cx26-G45E, a mutation that causes a lethal form of KID syndrome. |
