Multiple sites of L‐histidine decarboxylase expression in mouse suggest novel developmental functions for histamine

Abstract

Histamine mediates many types of physiologic signals in multicellular organisms. To clarify the developmental role of histamine, we have examined the developmental expression of L-histidine decarboxylase (HDC) mRNA and the production of histamine during mouse development. The predominant expression of HDC in mouse development was seen in mast cells. The HDC expression was evident from embryonal day 13 (Ed13) until birth, and the mast cells were seen in most peripheral tissues. Several novel sites with a prominent HDC mRNA expression were revealed. In the brain, the choroid plexus showed HDC expression at Ed14 and the raphe neurons at Ed15. Close to the parturition, at Ed19, the neurons in the tuberomammillary (TM) area and the ventricular neuroepithelia also displayed a clear HDC mRNA expression and histamine immunoreactivity (HA-ir). From Ed14 until birth, the olfactory and nasopharyngeal epithelia showed an intense HDC mRNA expression and HA-ir. In the olfactory epithelia, the olfactory receptor neurons (ORN) were shown to have very prominent histamine immunoreactivity. The bipolar nerve cells in the epithelium extended both to the epithelial surface and into the subepithelial layers to be collected into thick nerve bundles extending caudally toward the olfactory bulbs. Also, in the nasopharynx, an extensive subepithelial network of histamine-immunoreactive nerve fibers were seen. Furthermore, in the peripheral tissues, the degenerating mesonephros (Ed14) and the convoluted tubules in the developing kidneys (Ed15) showed HDC expression, as did the prostate gland (Ed15). In adult mouse brain, the HDC expression resembled the neuronal pattern observed in rat brain. The expression was restricted to the TM area in the ventral hypothalamus, with the main expression in the five TM subgroups called E1-E5. A distinct mouse HDC mRNA expression was also seen in the ependymal wall of the third ventricle, which has not been reported in the rat. The tissue- and cell-specific expression patterns of HDC and histamine presented in this work indicate that histamine could have cell guidance or regulatory roles in development.

Mouse embryonic stem cells express histidine decarboxylase and histamine H1 receptors

“…Although further studies are needed to elucidate the functions of histamine, HDC and H 1 R in the physiology of ES cells, these results support the observation that histamine may affect differentiation of certain cell lineages [8]. …”

Developmental expression pattern of monoamine oxidases in sensory organs and neural crest derivatives

“…During embryonic development, HDC is expressed in a variety of tissues, including the brain, sensory neurons of the OE, pharyngeal organ, and mast cells (Karlstedt et al, 2001). There are locations where we detected MAOB during development (Table 1).…”

Mammalian histidine decarboxylase: from structure to function

“…(38) There is also evidence of differential HDC expression depending on the differentiation/developmental stage. (6,39) Zhao and coworkers have reported that HDC can also be regulated at translational level in an important extent. (21) This work also claims the finding of a histamine auto-feedback inhibition on HDC in enterochromaffin-like cells.…”