Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study

Otero-Rodiño, Cristina; Rocha, Ana; Sánchez, Esteban Fernández; Álvarez-Otero, Rosa; Soengas, José L.; Cerdá‐Reverter, José Miguel

doi:10.3389/fendo.2019.00254

Cited by 12 publications

(10 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The agrp paralogs showed different spatial distributions in the brain of Atlantic salmon. The agrp1 was mainly expressed in the hypothalamus, as also described in previous studies in the ventral neurons of the NLT and rostral hypothalamus in goldfish (Cerdá-Reverter and Peter, 2003;Cerdá-Reverter et al, 2003a), sea bream (Koch et al, 2019), and rainbow trout (Otero-Rodiño et al, 2019). The agrp1 mRNA was also detected in other regions of the brain as saccus vasculosus and pituitary.…”

Section: Discussionsupporting

confidence: 85%

“…In goldfish and spotted sea bass, in situ hybridization showed neurons expressing mc4r in the telencephalon, thalamus, preoptic area, and hypothalamus (NLT and hypothalamic inferior lobe) ( Cerdá-Reverter et al, 2003a ; Zhang et al, 2019 ). Similarly, agrp and pomc were found in the NLT and in rostral hypothalamus of gold fish and rainbow trout ( Cerdá-Reverter and Peter, 2003 ; Cerdá-Reverter et al, 2003b ; Otero-Rodiño et al, 2019 ).…”

Section: Discussionmentioning

confidence: 83%

See 1 more Smart Citation

The Melanocortin System in Atlantic Salmon (Salmo salar L.) and Its Role in Appetite Control

et al. 2020

View full text Add to dashboard Cite

The melanocortin system is a key neuroendocrine network involved in the control of food intake and energy homeostasis in vertebrates. Within the hypothalamus, the system comprises two main distinct neuronal cell populations that express the neuropeptides proopiomelanocortin (POMC; anorexigenic) or agouti-related protein (AGRP; orexigenic). Both bind to the melanocortin-4 receptor (MC4R) in higher order neurons that control both food intake and energy expenditure. This system is relatively well-conserved among vertebrates. However, in Atlantic salmon (Salmo salar L.), the salmonid-specific fourth round whole-genome duplication led to the presence of several paralog genes which might result in divergent functions of the duplicated genes. In the current study, we report the first comprehensive comparative identification and characterization of Mc4r and extend the knowledge of Pomc and Agrp in appetite control in Atlantic salmon. In silico analysis revealed multiple paralogs for mc4r (a1, a2, b1, and b2) in the Atlantic salmon genome and confirmed the paralogs previously described for pomc (a1, a2, and b) and agrp (1 and 2). All Mc4r paralogs are relatively well-conserved with the human homolog, sharing at least 63% amino acid sequence identity. We analyzed the mRNA expression of mc4r, pomc, and agrp genes in eight brain regions of Atlantic salmon post-smolt under two feeding states: normally fed and fasted for 4 days. The mc4ra2 and b1 mRNAs were predominantly and equally abundant in the hypothalamus and telencephalon, the mc4rb2 in the hypothalamus, and a1 in the telencephalon. All pomc genes were highly expressed in the pituitary, followed by the hypothalamus and saccus vasculosus. The agrp genes showed a completely different expression pattern from each other, with prevalent expression of the agrp1 in the hypothalamus and agrp2 in the telencephalon. Fasting did not induce any significant changes in the mRNA level of mc4r, agrp, or pomc paralogs in the hypothalamus or in other highly expressed regions between fed and fasted states. The identification and wide distribution of multiple paralogs of mc4r, pomc, and agrp in Atlantic salmon brain provide new insights and give rise to new questions of the melanocortin system in the appetite regulation in Atlantic salmon.

show abstract

Section: Discussionsupporting

confidence: 85%

Section: Discussionmentioning

confidence: 83%

The Melanocortin System in Atlantic Salmon (Salmo salar L.) and Its Role in Appetite Control

et al. 2020

View full text Add to dashboard Cite

show abstract

“…As in mammals, the teleost feeding center seems to reside in the hypothalamic area (reviewed in Peter (1979)). Furthermore, several neuropeptides involved in appetite control, including AgRP and POMC, are present in the hypothalamus of teleost species (Cerdá-Reverter et al, 2003;Cerda-Reverter and Peter, 2003;Otero-Rodiño et al, 2019). Different nutrient status also modulate the expression of teleost hypothalamic neuropeptides (reviewed in Volkoff (2016); Delgado et al (2017); Rønnestad et al (2017)).…”

Section: Discussionmentioning

confidence: 99%

Hypothalamic agrp and pomc mRNA Responses to Gastrointestinal Fullness and Fasting in Atlantic Salmon (Salmo salar, L.)

et al. 2020

View full text Add to dashboard Cite

The orexigenic agouti-related protein (AgRP) and the anorexigenic pro-opiomelanocortin (POMC) are crucial players in the control of feed intake in vertebrates, yet their role in teleosts has not been fully established. Triplicate groups of Atlantic salmon (Salmo salar) post smolts were subjected to (1) fasting for 3 days (fast) and (2) normal feeding (fed), resulting in a significant (p < 0.05) upregulation of hypothalamic agrp1 transcripts levels in the fast group. Moreover, the mRNA abundance of agrp1 was significantly (p < 0.05) correlated with the stomach dry weight content. Corresponding inverse patterns were observed for pomca2, albeit not statistically significant. No significant differences were found for the other paralogues, agrp2 and pomca1 and b, between fed and fast groups. The significant correlation between stomach fullness and agrp1 mRNA expression suggests a possible link between the stomach filling/distension and satiety signals. Our study indicates that hypothalamic agrp1 acts as an orexigenic signal in Atlantic salmon.

show abstract

“…The two kinds of neurons transmit the signal to higher-order neurons to maintain the balance between energy expenditure and food intake. A considerable amount of literature provides evidence on a direct link between the mRNA level of hypothalamic neuropeptides and feeding behavior in rainbow trout ( Oncorhynchus mykiss ) [ 18 , 19 , 20 ]. Our prior work also initially explored the involvement of amino acids (leucine, valine, isoleucine, and histidine) in food intake control through hypothalamic neuropeptides in mandarin fish with ICV injection [ 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

Lysine Deprivation Regulates Npy Expression via GCN2 Signaling Pathway in Mandarin Fish (Siniperca chuatsi)

Zou

Zhu

Liang

et al. 2022

IJMS

View full text Add to dashboard Cite

Regulation of food intake is associated with nutrient-sensing systems and the expression of appetite neuropeptides. Nutrient-sensing systems generate the capacity to sense nutrient availability to maintain energy and metabolism homeostasis. Appetite neuropeptides are prominent factors that are essential for regulating the appetite to adapt energy status. However, the link between the expression of appetite neuropeptides and nutrient-sensing systems remains debatable in carnivorous fish. Here, with intracerebroventricular (ICV) administration of six essential amino acids (lysine, methionine, tryptophan, arginine, phenylalanine, or threonine) performed in mandarin fish (Siniperca chuatsi), we found that lysine and methionine are the feeding-stimulating amino acids other than the reported valine, and found a key appetite neuropeptide, neuropeptide Y (NPY), mainly contributes to the regulatory role of the essential amino acids on food intake. With the brain cells of mandarin fish cultured in essential amino acid deleted medium (lysine, methionine, histidine, valine, or leucine), we showed that only lysine deprivation activated the general control nonderepressible 2 (GCN2) signaling pathway, elevated α subunit of eukaryotic translation initiation factor 2 (eIF2α) phosphorylation, increased activating transcription factor 4 (ATF4) protein expression, and finally induced transcription of npy. Furthermore, pharmacological inhibition of GCN2 and eIF2α phosphorylation signaling by GCN2iB or ISRIB, effectively blocked the transcriptional induction of npy in lysine deprivation. Overall, these findings could provide a better understanding of the GCN2 signaling pathway involved in food intake control by amino acids.

show abstract

Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study

Cited by 12 publications

References 55 publications

The Melanocortin System in Atlantic Salmon (Salmo salar L.) and Its Role in Appetite Control

The Melanocortin System in Atlantic Salmon (Salmo salar L.) and Its Role in Appetite Control

Hypothalamic agrp and pomc mRNA Responses to Gastrointestinal Fullness and Fasting in Atlantic Salmon (Salmo salar, L.)

Lysine Deprivation Regulates Npy Expression via GCN2 Signaling Pathway in Mandarin Fish (Siniperca chuatsi)

Contact Info

Product

Resources

About