Differential expression of cocaine- and amphetamine-regulated transcript-immunoreactivity in the rat spinal preganglionic nuclei

doi:10.1016/S0304-3940(00)01575-5

Neuroscience Letters

Volume 294, Issue 3, 24 November 2000, Pages 143-146

https://doi.org/10.1016/S0304-3940(00)01575-5 Get rights and content

Abstract

The distribution of cocaine- and amphetamine-regulated transcript-like immunoreactivity (CART-LI) was investigated in the rat spinal cords with the use of an antiserum against the CART peptide fragment 55–102. CART-LI fibers were concentrated in the superficial layers of the dorsal horn of all segments. In addition to CART-LI fibers, intensely labeled somata were detected in the intermediolateral cell column (IML) and other sympathetic preganglionic nuclei of the thoracolumbar segments. In the lumbosacral segments, CART-LI fibers but not somata were seen in the sacral parasympathetic nucleus. Double-labeling the spinal sections with choline acetyltransferase (ChAT)-antisera and CART-antisera revealed that the large majority of ChAT-positive somata in the sympathetic preganglionic nuclei were CART-positive, whereas ChAT-positive somata in the parasympathetic preganglionic nuclei were CART-negative. Our results show that CART-LI is selectively expressed in a population of sympathetic preganglionic neurons (SPNs), but not in parasympathetic preganglionic neurons (PPNs) of the rat.

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Acknowledgements

This study was supported by NIH Grants NS18710 and NS39646 from the Department of Health and Human Services.

References (11)

P.R Couceyro et al.
Further studies on the anatomical distribution of CART by in situ hybridization
J. Chem. Neuroanat.
(1997)
N.J Dun et al.
Pituitary adenylate cyclase activating polypeptide immunoreactivity in the rat spinal cord and medulla: implication of sensory and autonomic function
Neuroscience
(1996)
N.J Dun et al.
Cocaine- and amphetamine-regulated transcript-immunoreactivity in the rat sympatho-adrenal axis
Neurosci. Lett.
(2000)
M.J Kuhar et al.
CART peptides: novel addiction- and feeding-related neuropeptides
Trends Neurosci.
(1999)
M Ohsawa et al.
Decrease of hindpaw withdrawal latency by cocaine- and amphetamine-regulated transcript peptide to the mouse spinal cord
Eur. J. Pharmacol.
(2000)

There are more references available in the full text version of this article.

Cited by (39)

Overexpressed beta cell CART increases insulin secretion in mouse models of insulin resistance and diabetes
2022, Peptides
Citation Excerpt :
In addition, we have previously demonstrated that CART is an important regulator of islet function and glucose homeostasis [4]. CART is expressed in the central [5], peripheral [6–8] and enteric [9,10] nervous systems, as well as in endocrine cells in e.g. the adrenal medulla [11], pituitary [11], the GI-tract [9], and the thyroid [12]. We have shown that CART is expressed in the pancreatic islets in rodents, pigs and humans, in nerve fibres innervating the islets [12], and/or in endocrine islet cells [4,13–15].
Impaired beta cell function and beta cell death are key features of type 2 diabetes (T2D). Cocaine- and amphetamine-regulated transcript (CART) is necessary for normal islet function in mice. CART increases glucose-stimulated insulin secretion in vivo in mice and in vitro in human islets and CART protects beta cells against glucotoxicity-induced cell death in vitro in rats. Furthermore, beta cell CART is upregulated in T2D patients and in diabetic rodent models as a consequence of hyperglycaemia. The aim of this study was to assess the impact of upregulated beta cell CART on islet hormone secretion and glucose homeostasis in a transgenic mouse model.
To this end, mice with beta cell-specific overexpression of CART (CARTtg mice) were generated. CARTtg mice challenged by aging, high fat diet feeding or streptozotocin treatment were phenotyped with respect to in vivo and in vitro insulin and glucagon secretion, glucose homeostasis, and beta cell mass. In addition, the impact of adenoviral overexpression of CART on insulin secretion was studied in INS-1 832/13 cells.
CARTtg mice had a normal metabolic phenotype under basal conditions. On the other hand, with age CARTtg mice displayed increased insulin secretion and improved glucose elimination, compared with age-matched WT mice. Furthermore, compared with WT controls, CARTtg mice had increased insulin secretion after feeding a high fat diet, as well as lower glucose levels and higher insulin secretion after streptozotocin treatment. Viral overexpression of CART in INS-1 832/13 cells resulted in increased glucose-stimulated insulin secretion. Together, these results imply that beta cell CART acts to increase insulin secretion when beta cell function is challenged. We propose that the increase in beta cell CART is part of a compensatory mechanisms trying to counteract the hyperglycaemia in T2D.
Hydralazine administration activates sympathetic preganglionic neurons whose activity mobilizes glucose and increases cardiovascular function
2015, Brain Research
Citation Excerpt :
SPN were then analyzed for the presence or absence of c-Fos-ir, CART-ir and PPE mRNA. The distribution of CART-ir was used to help determine the location of SPN as it is strongly expressed in the intermediolateral cell column (IML) and is also found in the central autonomic area (CAA), and dorsolateral funiculus (DLF) (Dun et al., 2000; Fenwick et al., 2006; Gonsalvez et al., 2010). Qualitative analysis of PNMT, CART and c-Fos-ir was also determined in adrenal glands by examining their distribution.
Hypotensive drugs have been used to identify central neurons that mediate compensatory baroreceptor reflex responses. Such drugs also increase blood glucose. Our aim was to identify the neurochemical phenotypes of sympathetic preganglionic neurons (SPN) and adrenal chromaffin cells activated following hydralazine (HDZ; 10 mg/kg) administration in rats, and utilize this and SPN target organ destination to ascribe their function as cardiovascular or glucose regulating. Blood glucose was measured and adrenal chromaffin cell activation was assessed using c-Fos immunoreactivity (-ir) and phosphorylation of tyrosine hydroxylase, respectively. The activation and neurochemical phenotype of SPN innervating the adrenal glands and celiac ganglia were determined using the retrograde tracer cholera toxin B subunit, in combination with in situ hybridization and immunohistochemistry. Blood glucose was elevated at multiple time points following HDZ administration but little evidence of chromaffin cell activation was seen suggesting non-adrenal mechanisms contribute to the sustained hyperglycemia. 16±0.1% of T4-T11 SPN contained c-Fos and of these: 24.3±1.4% projected to adrenal glands and 29±5.5% projected to celiac ganglia with the rest innervating other targets. 62.8±1.4% of SPN innervating adrenal glands were activated and 29.9±3.3% expressed PPE mRNA whereas 53.2±8.6% of SPN innervating celiac ganglia were activated and 31.2±8.8% expressed PPE mRNA. CART-ir SPN innervating each target were also activated and did not co-express PPE mRNA. Neurochemical coding reveals that HDZ administration activates both PPE+SPN, whose activity increase glucose mobilization causing hyperglycemia, as well as CART+SPN whose activity drive vasomotor responses mediated by baroreceptor unloading to raise vascular tone and heart rate.
Increase in cocaine- and amphetamine-regulated transcript (CART) in specific areas of the mouse brain by acute caffeine administration
2014, Neuropeptides
Caffeine produces a variety of behavioral effects including increased alertness, reduced food intake, anxiogenic effects, and dependence upon repeated exposure. Although many of the effects of caffeine are mediated by its ability to block adenosine receptors, it is possible that other neural substrates, such as cocaine- and amphetamine-regulated transcript (CART), may be involved in the effects of caffeine. Indeed, a recent study demonstrated that repeated caffeine administration increases CART in the mouse striatum. However, it is not clear whether acute caffeine administration alters CART in other areas of the brain. To explore this possibility, we investigated the dose- and time-dependent changes in CART immunoreactivity (CART-IR) after a single dose of caffeine in mice. We found that a high dose of caffeine (100 mg/kg) significantly increased CART-IR 2 h after administration in the nucleus accumbens shell (AcbSh), dorsal bed nucleus of the stria terminalis (dBNST), central nucleus of the amygdala (CeA), paraventricular hypothalamic nucleus (PVN), arcuate hypothalamic nucleus (Arc), and locus coeruleus (LC), and returned to control levels after 8 h. But this increase was not observed in other brain areas. In addition, caffeine administration at doses of 25 and 50 mg/kg appears to produce dose-dependent increases in CART-IR in these brain areas; however, the magnitude of increase in CART-IR observed at a dose of 50 mg/kg was similar or greater than that observed at a dose of 100 mg/kg. This result suggests that CART-IR in AcbSh, dBNST, CeA, PVN, Arc, and LC is selectively affected by caffeine administration.
Cocaine- and amphetamine-regulated transcript is expressed in adipocytes and regulate lipid- and glucose homeostasis
2013, Regulatory Peptides
Citation Excerpt :
Adipose tissue is central in maintaining lipid and glucose homeostasis and an expanding adipose tissue leads to increased free fatty acid (FFA) release from the adipocytes, altered adipokine release and low-grade inflammation [2]. Cocaine- and amphetamine-regulated transcript (CART) is an anorexigenic peptide [3–6] highly expressed in the brain, the peripheral nervous system [7–9] as well as in the enteric nervous system [10,11]. CART is also expressed in pancreatic islet cells and in nerve fibers innervating the islets in rats, mice, pigs [10,12–14] and humans (Riva et al., unpublished data).
Cocaine- and amphetamine-regulated transcript (CART) is a regulatory peptide expressed in the nervous system and in endocrine cells, e.g. in pancreatic islets. CART deficient mice exhibit islet dysfunction, impaired insulin secretion and increased body weight. A mutation in the CART gene in humans is associated with reduced metabolic rate, obesity and diabetes. Furthermore, CART is upregulated in islets of type-2 diabetic rats and regulates islet hormone secretion in vitro. While the function of CART in the nervous system has been extensively studied, there is no information on its expression or function in white adipose tissue. CART mRNA and protein were found to be expressed in both subcutaneous and visceral white adipose tissue from rat and man. Stimulating rat primary adipocytes with CART significantly potentiated isoprenaline-induced lipolysis, and hormone sensitive lipase activation (phosphorylation of Ser 563). On the other hand, CART significantly potentiated the inhibitory effect of insulin on isoprenaline-induced lipolysis. CART inhibited insulin-induced glucose uptake and lipogenesis, which was associated with inhibition of PKB phosphorylation.
In conclusion, CART is a novel constituent of human and rat adipocytes and affects several biological processes central in both lipid- and glucose homeostasis. Depending on the surrounding conditions, the effects of CART are insulin-like or insulin-antagonistic.
Distribution pattern of CART-containing neurons and cells in the human pancreas
2012, Acta Histochemica
Citation Excerpt :
In both rat and mouse pancreas, CART is present in parasympathetic and sensory nerves, emanating from spinal ganglia (Wierup et al., 2004, 2005). The collected data indicate that CART belongs to an already large family of regulatory peptides with a distribution in central and peripheral nerves, including sympathetic preganglionic (Dun et al., 2000b), primary sensory (Dun et al., 2000a), and enteric (Couceyro et al., 1998; Ekblad et al., 2003) neurons. CART has been localized in several organs of the gastrointestinal tract, like stomach, duodenum, small intestine, colon, rectum, and myenteric plexus neurons.
Cocaine- and amphetamine-regulated transcript (CART) has been shown to play a critical role in appetite suppression, cell survival, thermoregulation, glucose sensing, stimulation of hormone secretion, as well as for the regulatory function of the islets of Langerhans. Although the principal site of CART synthesis has already been reported, our knowledge of the subject is mainly based on and limited to research conducted on animals owing to difficulties in obtaining human samples. Therefore, the primary goal of the reported study was an attempt to identify and localize CART in healthy human pancreas. Nineteen deceased subjects (donors of organs) with normal pancreas and alimentary tract were used in the study. After determination of brain death and confirmation of death by the relevant doctors committee, pancreas samples, about 1 cm long, were collected from each corpse (the same part of the pancreas) after the organs were harvested for transplantation. Paraffin sections were made and stained with hematoxylin and eosin and then subjected to CART immunohistochemistry. In the normal pancreas of human adults, CART is mainly present in both nerve fibers and in nerve cell bodies in pancreatic ganglia. In addition to pancreatic neurons, immunoreactivity to CART was also seen in islet endocrine cells. This is the first report on the presence of CART-IR structures in the normal human pancreas. CART should be now added to the numerous regulatory peptides that are involved in the complex regulation of pancreatic endocrine and exocrine processes.
Forced swim stress elicits region-specific changes in CART expression in the stress axis and stress regulatory brain areas
2012, Brain Research
Citation Excerpt :
Furthermore, anatomical structures composing the sympatho-adrenal axis highly express CART mRNA and peptides. Sympathetic preganglionic neurons which reside in the IML of the spinal cord are CART-positive (Dun et al., 2000b; Koylu et al., 1998). CART-IR is present especially in cardiovascular preganglionic neurons (Gonsalvez et al., 2010).
CART mRNA and peptides are highly expressed in the anatomical structures composing the hypothalamo-pituitary-adrenal (HPA) axis and sympatho-adrenal system. Anatomical and functional studies suggest that CART peptides may have a role in the regulation of the neuroendocrine and autonomic responses during stress. Our previous study showed that CART peptides increased significantly in the male hypothalamus and amygdala 10 min after the forced swim stress. The present study aimed to examine the effect of forced swim stress on CART peptide expression in selected brain regions, including those where CART peptide expression has not been reported before (frontal cortex, pons, medulla oblongata), as well as in endocrine glands related to stress in male Sprague Dawley rats. A total of 16 (n = 8) animals were used, including control groups. Rats were subjected to forced swim on two consecutive days, and sacrificed on the second day, 2 h after the termination of the stress procedure. Frontal cortex, pons, medulla oblongata, hypothalamus, pituitary and adrenal glands were dissected and homogenized. CART peptide expression in these tissues was measured by Western Blotting and six different CART peptide fragments were identified. Our results showed that forced swim stress elicited region-specific changes in CART peptide expression. CART was upregulated in the frontal cortex, hypothalamus, medulla oblongata and adrenal gland while there was no change in the pons and pituitary. Enhanced CART peptide fragments in these brain regions and adrenal glands may have a role in the regulation of the HPA and sympatho-adrenal axis activity during stress response.

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¹: Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG 35400–000, Brazil

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Differential expression of cocaine- and amphetamine-regulated transcript-immunoreactivity in the rat spinal preganglionic nuclei

Abstract

Section snippets

Acknowledgements

J. Chem. Neuroanat.

Neuroscience

Neurosci. Lett.

Trends Neurosci.

Eur. J. Pharmacol.