Expression of Ghrelin and its Receptor in Human Tissues

Abstract

Ghrelin is a peptide thought to be involved in the regulation of appetite. Furthermore, significant effects on the release of growth hormone (GH) and ACTH were demonstrated. Contributing to the physiological relevance of this hormone, we investigated the expression of ghrelin and its receptor (GHS-R) in several normal human tissues. RNA samples (BD Biosciences) underwent one-step TaqMan Real-Time RT-PCR. Immunohistochemistry was performed on paraffin-embedded tissues using specific primary antibodies against ghrelin and its receptor. Relevant ghrelin mRNA levels were detected in all human tissues with the highest levels in stomach, pituitary, and small intestine. By immunohistochemistry, ghrelin peptide expression was detectable in reproductive and endocrine organs (ovary, anterior pituitary, adrenal gland), and organs of the gastrointestinal tract (stomach, pancreas). GHS-R1a mRNA expression was demonstrated in 10 of 24 human organs analyzed with the highest levels in pituitary, adrenal gland, and spinal cord. Expression of the receptor peptide was detected by immunohistochemistry in endocrine and reproductive organs (anterior pituitary, thyroid, pancreas, testis), parts of the CNS (cerebrum, cerebellum), and in single cells of bone marrow. Expression of both ghrelin and its receptor in endocrine and reproductive organs may indicate new endocrine or paracrine mechanisms of regulation in these tissues.

Ghrelin and obestatin in thyroid gland — immunohistochemical expression in nodular goiter, papillary and medullary cancer

“…However, further studies revealed that it is a multifunctional hormone and an essential regulator of metabolic processes [3]. Ghrelin is released mainly from gastric mucosa [5], but to a lesser extent it was demonstrated also in most other central and peripheral tissues [6]. Previous studies indicated that the active form of ghrelin is uniquely modified (octanoylated at Ser 3 residue) [7,8] and its biological effects are transduced by ghrelin receptor type 1a (GHS-R1a) [3].…”

“…Ghrelin has been demonstrated in parafollicular cells and medullary thyroid cancer cells [12][13][14]. Ghrelin binding sites have been shown in the thyroid [6] and exogenous ghrelin uptake in the thyroid gland was demonstrated to be notably higher than in other tissues [15].…”

Effect of intranasal ghrelin administration on the compulsive behavior patterns and the level of anxiety after the vital stress exposure to rats

“…Кроме того, гре-лин повышал экспрессию гена КРГ в паравентри-кулярном ядре гипоталамуса [18]. Существует мнение о родстве между грелином и кортиколи-берином, поскольку грелиновые рецепторы были найдены в паравентрикулярном ядре -основ-ном источнике кортиколиберина и в ядре Вестфа-оригинальные исследования ля -Эдингера (Якубовича) -месте экспрессии урокортина [30].…”

Cloning of a novel insulin-regulated ghrelin transcript in prostate cancer

“…GenBank entries corresponding to the novel cryptic exons are indicated by a red box. the wild-type ghrelin transcript (Gnanapavan et al 2002, Ueberberg et al 2009, is expressed in a small number of tissues, including the stomach, lymph node, peripheral blood leucocytes, testis, epididymis, skin and adrenal gland (Fig. 4).…”