Figure 7.

Impaired alkaline phosphatase (ALPase) activity of osteoblasts, odotoblasts and ameloblasts in Trpm7^Δkinase∕+ mice is partially retrieved by Mg²⁺ pre-treatment. (A) At the bone forming site, ALPase activity was detected (in red) on the plasma membrane of osteoblasts (Os) and its precursor cells (preOs) in wt mice. (B)There was no ALPase activity presented by osteoblasts in Trpm7^Δkinase∕+ mice. (C) However, Mg²⁺ pre-treatment retrieved the ALPase activity on osteoblasts. (D) ALPase activity was detected at the basolateral surface of odontoblasts (Od) in wt mice. (E) While in Trpm7^Δkinase∕+ mice, no ALPase activity was seen in the odontoblasts. (F) Mg²⁺ pre-treatment retrieved ALPase activity on odontoblasts. (J) ALPase activity was detected in stratum intermedium (SI), secretory ameloblasts (Am), and (G) papillary layer cells (P) at maturation stage in wt mice. In Trpm7^Δkinase∕+ mice, ALPase activities were restricted only on the stratum intermedium at secretory stage, not in ameloblasts (H,K). Mg²⁺ pre-treatment retrieved the ALPase activity on ameloblasts and papillary layer cells (I,L). Dn, dentin; pre-Dn, pre-dentin; En, enamel; Scale bars: 25 μm.