Chemistry:Neurotensin
| Neurotensin/neuromedin N precursor | |||||||||
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| Symbol | Pro-NT_NN | ||||||||
| Pfam | PF07421 | ||||||||
| InterPro | IPR008055 | ||||||||
| OPM superfamily | 257 | ||||||||
| OPM protein | 2oyv | ||||||||
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| Properties | |
| C78H121N21O20 | |
| Molar mass | 1672.92 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
Neurotensin is a 13 amino acid neuropeptide that is implicated in the regulation of luteinizing hormone and prolactin release and has significant interaction with the dopaminergic system. Neurotensin was first isolated from extracts of bovine hypothalamus based on its ability to cause a visible vasodilation in the exposed cutaneous regions of anesthetized rats.[1]
Neurotensin is distributed throughout the central nervous system, with highest levels in the hypothalamus, amygdala and nucleus accumbens. It induces a variety of effects, including analgesia, hypothermia, and increased locomotor activity. It is also involved in regulation of dopamine pathways. In the periphery, neurotensin is found in enteroendocrine cells of the small intestine, where it leads to pancreatic and biliary secretion, reduced gastric acid secretion, and smooth muscle contraction.[2]
Sequence and biosynthesis
Neurotensin shares significant sequence similarity in its 6 C-terminal amino acids with several other neuropeptides, including neuromedin N (which is derived from the same precursor). This C-terminal region is responsible for the full biological activity, the N-terminal portion having a modulatory role. The neurotensin/neuromedin N precursor can also be processed to produce large 125–138 amino acid peptides with the neurotensin or neuromedin N sequence at their C terminus. These large peptides appear to be less potent than their smaller counterparts, but are also less sensitive to degradation and may represent endogenous, long-lasting activators in a number of pathophysiological situations.
The sequence of bovine neurotensin was determined to be pyroGlu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu-OH.[3] Neurotensin is synthesized as part of a 169 or 170 amino acid precursor protein that also contains the related neuropeptide neuromedin N.[4][5] The peptide coding domains are located in tandem near the carboxyl terminal end of the precursor and are bounded and separated by paired basic amino acid (lysine-arginine) processing sites.
Function
Neurotensin is involved in a variety of central and peripheral processes. In the brain, it plays a role in modulating hormone activity, social behavior, and learning. For example, neurotensin-expressing neurons in the medial preoptic area (mPOA) of mice project to the ventral tegmental area (VTA), where they contribute to social reward processing and the encoding of odor cues, suggesting a role in both hormonal signaling and reward circuits.[6]
Neurotensin also appears to influence learning processes. In male zebra finches, expression of neurotensin and its receptor genes varies during song development. Both neurotensin and neurotensin receptor mRNA levels decrease during the transition from the sensory to sensorimotor phases of development, implicating neurotensin in the onset of sensorimotor learning. Later in development, neurotensin and neurotensin receptor 1 (Ntsr1) show complementary expression patterns in song-related brain regions, suggesting dynamic modulation of neural responses.[7]
In a 2026 study published in PNAS, researchers demonstrated that neurotensin signaling in the extended amygdala plays a key role in maintaining exploratory or adaptive behaviors when animals are exposed to novel environments. Through targeted activation and silencing techniques, the study showed this pathway helps sustain responses beyond initial novelty detection.[8]
In peripheral tissues, neurotensin is predominantly expressed in the gastrointestinal tract, where it participates in digestion and local signaling. Its aberrant expression has also been associated with tumorigenesis.
Regulation
Neurotensin gene expression is modulated by hormonal and intracellular signaling pathways. In human SK-N-SH neuroblastoma cell cultures and in mice, estrogen has been shown to enhance neurotensin transcription through the activation of cyclic AMP (cAMP) signaling pathways. Estrogen increases cAMP levels and promotes phosphorylation of cAMP response element-binding protein (CREB), a precursor event to neurotensin gene activation. This effect is absent in knockout mice lacking the RIIβ subunit of protein kinase A, highlighting the importance of the cAMP/PKA signaling axis in neurotensin regulation.[9] In female rats, neurotensin mRNA expression peaks in the mPOA during the proestrus phase of the estrous cycle, suggesting regulation by ovarian hormones.[10] Postpartum hormonal states also influence neurotensin and neurotensin receptor expression. In postpartum female mice, neurotensin levels were increased in the paraventricular nucleus (PVN) of the hypothalamus despite reduced Ntsr1 mRNA. Both neurotensin mRNA and peptide levels were elevated in the mPOA, changes that were absent in virgin controls. These patterns are consistent with a regulatory role in maternal behaviors.[11]
Clinical significance
Aberrant neurotensin signaling has been implicated in several pathological conditions, particularly in cancer. In colorectal cancer cells, expression of neurotensin receptor genes (NTSR1 and NTSR2) is regulated by promoter DNA methylation. Downregulation of NTSR1 through RNA interference or pharmacological antagonism results in reduced cell proliferation and migration, indicating a tumor-promoting role for this pathway.[12] Neurotensin expression has also been observed in leiomyomas, or fibroid tumors, of the uterus. Both neurotensin and NTSR1 levels are elevated in fibroid tissues compared to normal uterine tissue, suggesting a role in the pathophysiology of uterine smooth muscle proliferation.[13]
Neurotensin is a potent mitogen for colorectal cancer.[14]
Neurotensin has been implicated in the modulation of dopamine signaling, and produces a spectrum of pharmacological effects resembling those of antipsychotic drugs, leading to the suggestion that neurotensin may be an endogenous neuroleptic. Neurotensin-deficient mice display defects in responses to several antipsychotic drugs consistent with the idea that neurotensin signaling is a key component underlying at least some antipsychotic drug actions.[15] These mice exhibit modest defects in prepulse inhibition (PPI) of the startle reflex, a model that has been widely used to investigate antipsychotic drug action in animals. Antipsychotic drug administration augments PPI under certain conditions. Comparisons between normal and neurotensin-deficient mice revealed striking differences in the ability of different antipsychotic drugs to augment PPI. While the atypical antipsychotic drug clozapine augmented PPI normally in neurotensin-deficient mice, the conventional antipsychotic haloperidol and the newer atypical antipsychotic quetiapine were ineffective in these mice, in contrast to normal mice where these drugs significantly augmented PPI. These results suggest that certain antipsychotic drugs require neurotensin for at least some of their effects. Neurotensin-deficient mice also display defects in striatal activation following haloperidol, but not clozapine administration in comparison to normal wild type mice, indicating that striatal neurotensin is required for the full spectrum of neuronal responses to a subset of antipsychotic drugs.[16]
Neurotensin is an endogenous neuropeptide involved in thermoregulation that can induce hypothermia and neuroprotection in experimental models of cerebral ischemia.[17]
See also
References
- ↑ "The isolation of a new hypotensive peptide, neurotensin, from bovine hypothalami". Journal of Biological Chemistry 248 (19): 6854–6861. Oct 1973. doi:10.1016/S0021-9258(19)43429-7. PMID 4745447.
- ↑ "Production of recombinant large proneurotensin/neuromedin N-derived peptides and characterization of their binding and biological activity". Biochemical and Biophysical Research Communications 290 (4): 1161–1168. February 2002. doi:10.1006/bbrc.2001.6308. PMID 11811984.
- ↑ "The amino acid sequence of a hypothalamic peptide, neurotensin". Journal of Biological Chemistry 250 (5): 1907–1911. Mar 1975. doi:10.1016/S0021-9258(19)41780-8. PMID 1167549.
- ↑ "Cloning and sequence analysis of cDNA for the canine neurotensin/neuromedin N precursor". Proceedings of the National Academy of Sciences of the United States of America 84 (10): 3516–3520. May 1987. doi:10.1073/pnas.84.10.3516. PMID 3472221. Bibcode: 1987PNAS...84.3516D.
- ↑ "The rat gene encoding neurotensin and neuromedin N. Structure, tissue-specific expression, and evolution of exon sequences". Journal of Biological Chemistry 263 (10): 4963–4968. Apr 1988. doi:10.1016/S0021-9258(18)68881-7. PMID 2832414.
- ↑ "Hormonal gain control of a medial preoptic area social reward circuit" (in en). Nature Neuroscience 20 (3): 449–458. March 2017. doi:10.1038/nn.4487. ISSN 1546-1726. PMID 28135243.
- ↑ "Neurotensin and neurotensin receptor 1 mRNA expression in song-control regions changes during development in male zebra finches" (in en). Developmental Neurobiology 78 (7): 671–686. 2018. doi:10.1002/dneu.22589. ISSN 1932-846X. PMID 29569407.
- ↑ "Neurotensin in the extended amygdala maintains …". Proceedings of the National Academy of Sciences 123 (6). 2026. doi:10.1073/pnas.2521268123.
- ↑ "Transcriptional Effects of Estrogen on Neuronal Neurotensin Gene Expression Involve cAMP/Protein Kinase A-Dependent Signaling Mechanisms" (in en). The Journal of Neuroscience 18 (17): 6672–6680. 1998-09-01. doi:10.1523/JNEUROSCI.18-17-06672.1998. ISSN 0270-6474. PMID 9712639.
- ↑ "Neurotensin Gene Expression Increases during Proestrus in the Rostral Medial Preoptic Nucleus: Potential for Direct Communication with Gonadotropin-Releasing Hormone Neurons*". Endocrinology 142 (7): 3006–3013. 2001-07-01. doi:10.1210/endo.142.7.8256. ISSN 0013-7227. PMID 11416022.
- ↑ "Endogenous CNS Expression of Neurotensin and Neurotensin Receptors Is Altered during the Postpartum Period in Outbred Mice" (in en). PLOS ONE 9 (1). 2014-01-08. doi:10.1371/journal.pone.0083098. ISSN 1932-6203. PMID 24416154. Bibcode: 2014PLoSO...983098D.
- ↑ "Diverse expression patterns and tumorigenic role of neurotensin signaling components in colorectal cancer cells". International Journal of Oncology 50 (6): 2200–2206. 2017-06-01. doi:10.3892/ijo.2017.3990. ISSN 1019-6439. PMID 28498396.
- ↑ "Neurotensin and Neurotensin Receptor 1 Expression in Human Myometrium and Uterine Leiomyomas1". Biology of Reproduction 83 (4): 641–647. 2010-10-01. doi:10.1095/biolreprod.110.084962. ISSN 0006-3363. PMID 20592307.
- ↑ "Curcumin inhibits neurotensin-mediated interleukin-8 production and migration of HCT116 human colon cancer cells". Clinical Cancer Research 12 (18): 5346–5355. September 2006. doi:10.1158/1078-0432.CCR-06-0968. PMID 17000667.
- ↑ "Neurotensin-deficient mice have deficits in prepulse inhibition: restoration by clozapine but no haloperidol, olanzapine, or quetiapine". The Journal of Pharmacology and Experimental Therapeutics 315 (1): 256–264. Oct 2005. doi:10.1124/jpet.105.087437. PMID 15987829. http://jpet.aspetjournals.org/cgi/content/abstract/315/1/256.
- ↑ "Neurotensin-deficient mice show altered responses to antipsychotic drugs". Proceedings of the National Academy of Sciences of the United States of America 98 (14): 8048–8053. Jul 2001. doi:10.1073/pnas.141042198. PMID 11427716. Bibcode: 2001PNAS...98.8048D.
- ↑ "Neurotensin-induced hypothermia improves neurologic outcome after hypoxic-ischemia". Critical Care Medicine 32 (3): 806–810. March 2004. doi:10.1097/01.CCM.0000114998.00860.FD. PMID 15090966.
External links
- Neurotensin at the US National Library of Medicine Medical Subject Headings (MeSH)
- "A Good Memory or a Bad One? One Brain Molecule Decides." (in en). 2022-09-07. https://www.quantamagazine.org/a-good-memory-or-a-bad-one-one-brain-molecule-decides-20220907/.
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