Ontogeny of estrogen receptor alpha, estrogen receptor beta and androgen receptor, and their co-localization with Islet-1 in the dorsal root ganglia of sheep fetuses during gestation

Abstract

The aims of the present study were to detect the ontogeny of estrogen receptor (ERalpha and ERbeta) and androgen receptor (AR) expressions and their co-localization with Islet-1 in the developing dorsal root ganglia (DRG) of sheep fetuses by immunohistochemistry. From the single staining results, the ERalpha immunoreactivity (ERalpha-ir), ERbeta immunoreactivity (ERbeta-ir) and AR immunoreactivity (AR-ir) was first detected at days 90, 120 and 90 of gestation, respectively. From days 90 to 120, ERalpha and AR were consistently detected in the nuclei of DRG neurons and the relative percentage (approximately 60%) of ERalpha-ir or AR-ir cells did not change significantly. Moreover, there was no change in ERalpha expression, while a dramatic loss of AR expression was observed at birth. From day 120 of gestation to birth, very few neurons (approximately 8%) showed nuclear ERbeta immunoreactivity. The dual staining results showed that Islet-1 was co-localized with ERalpha, ERbeta or AR in the nuclei of DRG neurons with various frequencies, and over 70% ERalpha-ir, ERbeta-ir or AR-ir cells contained Islet-1. These results imply that ERs, AR and Islet-1 may be important in regulating the differentiation and functional maintenance of some phenotypes of DRG neurons after mid-gestation in the sheep fetus.

Androgen and estrogen receptor expression in the spinal segments of the genitofemoral nerve during testicular descent

“…In addition, AR messenger RNA has been isolated in the spinal cord and DRG of E male mice [12]; however, this did not include protein expression. Androgen receptor protein expression has, however, been documented in L6-L7 DRG of E90 sheep [13]; however, these levels do not supply the GFN. Furthermore, the E90 sheep developmental stage is further progressed than the E16-to-E19 developmental stage of the rat.…”

A Simple Technique for the Prediction of Interacting Proteins Reveals a Direct Brn-3a-Androgen Receptor Interaction

“…As well as being expressed in developing DRG (48), the involvement of AR and androgens in inducing neurite outgrowth in other neural subtypes is well established, most notably in motoneurons (49,50). Indeed, as in the case of Brn-3a (11,12,14), the overexpression of AR in ND7 cells is sufficient to induce neurite outgrowth (data not shown).…”

“…In light of this, it is interesting to speculate on what effect the relative expression of Brn-3a and AR in peripheral neurons may have on the sensation of pain. For example, AR is expressed in developing DRG, but its expression drops markedly at birth (48), whereas Brn-3a expression endures into adulthood (9). It may be the case, therefore, that individuals suffering from idiopathic pain have higher AR levels than normal controls, thus making AR (and indeed the Brn-3a-AR interaction) a potential target for the treatment of pain.…”

State-of-the-art technologies, current opinions and developments, and novel findings: news from the field of histochemistry and cell biology

“…In the nervous system, estrogen and androgen receptors are found, and diverse eVects of the steroids in diVerent parts of the central and peripheral nervous system have been described (see Luo et al 2008). In addition to neurotrophic factors, both estrogen and androgens have been shown to play important roles in DRG neuronal survival and neuronal properties (e.g., Patrone et al 1999).…”

“…In addition to neurotrophic factors, both estrogen and androgens have been shown to play important roles in DRG neuronal survival and neuronal properties (e.g., Patrone et al 1999). Luo et al (2008) studied the expression of ERs and androgen receptors (AR) in the developing DRGs of sheep fetuses. Additionally, they determined the colocalization of the receptors with the homeodomain transcription factor islet-1, which is important in neuronal survival, fate speciWcation, and other developmental processes.…”