Expression of hypoxia‐inducible, membrane‐bound carbonic anhydrase isozyme XII in mouse tissues

Abstract

Carbonic anhydrase (CA) XII is a membrane-associated enzyme that has been demonstrated to be normally expressed in some human tissues, to be upregulated in some cancers, and to be a hypoxia-inducible gene product. In mouse, CA XII has been recently localized in the kidney. In the present study, we investigated CA XII gene and protein expression in other mouse tissues, with the kidney serving as a positive control for the reagents. The expression of CA XII mRNA was examined using polymerase chain reaction (PCR) amplification of commercial cDNAs produced from selected mouse tissues. A strong positive signal for CA XII mRNA was detected in the kidney, and weak signals were obtained in the testis and lung. Heart, spleen, liver, and skeletal muscle were negative. Immunohistochemical staining was performed using a mouse CA XII-specific antibody and biotin-streptavidin complex method. The results showed high expression of CA XII in the kidney, as expected. It was also highly expressed in the surface epithelial cells of the colon, whereas it was absent in the stomach, proximal small intestine, pancreas, liver, heart, and skeletal muscle. The maturing sperm cells showed a weak staining in a pattern that most probably indicates expression in the developing acrosomal membrane. The high expression in the kidney and colon suggests a role for CA XII in the maintenance of body ion and pH homeostasis in the mouse. However, the present findings demonstrated that CA XII has a very limited distribution in mouse tissues outside these two organs. Anat Rec Part A 277A: 171-177, 2004.

Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor

“…Although the function of RNASE4 is not established, ANG1 is part of the acute phase response to infection and has potent antibacterial and antimycotic actions (23). Carbonic anhydrase 12 (CAR12) is a member of a family of proteins involved in the maintenance of pH and ion balance (24). The regulation of all of these genes by FXR was confirmed by RTQ-PCR by using WT, CYP27-KO, and FXR-KO mice administered either GW4064 or vehicle (Fig.…”

Tumor-associated carbonic anhydrases are linked to metastases in primary cervical cancer

“…It has been reported that CA12 expression is linked to more differentiated, less invasive status of the tumor cells of the human breast cancer tissues (Wykoff et al 2001). Besides, CA12 expression became stronger with increasing age of mouse embryos, indicating developmental regulation of this protein (Halmi et al 2004). Usually, CA12 is distributed in a variety of normal tissues and its expression becomes stronger in tumors originating from those same tissues (Ivanov et al 2001).…”

Expression profile of carbonic anhydrases in articular cartilage

“…Boeuf et al [30] demonstrated that an elevated CA IX expression is a risk factor of cartilage tumor metastasis. CAs IX and XII are particularly important for extracellular pH regulation and electrolyte balance because of the localization of their CA domains on the extracellular surface of cell plasma membranes [28,29]. It is generally accepted that the avascular articular cartilage is hypoxic [31].…”

“…CAs IX and XII are expressed in multiple tissues and their expression is regulated by tissue hypoxia [27,28]. As a marker of hypoxia, their expression in cancer tissue is of interest in cancer therapy and prognosis [3,29].…”