One evidence of cocaine- and amphetamine-regulated transcript (CART) has the bidirectional effects on appetite in Siberian sturgeon (Acipenser baerii)

Abstract

Cocaine- and amphetamine-regulated transcript (CART), discovered in 1995, with various biological functions, has received much attention recently due to its role in the regulation of appetite in mammals. However, the function of CART on the appetite control in fish species is still not very clear. In this study, Siberian sturgeon (Acipenser baerii Brandt) cart gene was cloned for the first time, and the cart mRNA levels in 11 feeding-related tissues was investigated. The Siberian sturgeon cart gene sequence was 1459 base pairs (bp), including a 3'-terminal untranslated region (3'-UTR) of 39 bp, a 5'-terminal untranslated region (5'-UTR) of 52 bp, and an open reading frame (ORF) of 348 bp encoding 115 amino acids. Siberian sturgeon cart gene has three exons and two introns including 341 bp intron 1 and 679 bp intron 2. The result of tissue distribution showed that cart was widely distributed in 11 tissues with the highest expression in the whole brain. The effects of periprandial (pre- and post-feeding), fasting, and re-feeding on cart mRNA abundance in the whole brain were assessed. Periprandial result showed the expression of cart mRNA in the whole brain significantly elevated after feeding for 3 h. However, fasting experiment showed that the level of cart significantly decreased after 1 day of fasting, but that significantly increased after 3-17 days of food deprivation and returned to the basic level after 3 days of re-feeding in the fishes which were fasted for 15 days. In conclusion, this study suggests that CART has the bidirectional effects on appetite, which acts as a satiety factor in short-term feeding regulation but as a starvation factor in long-term appetite regulation in Siberian sturgeon.

Brain Distribution of 10 cart Transcripts and Their Response to 4 Days of Fasting in Atlantic Salmon (Salmo salar L.)

“…Hence, in Atlantic salmon, hypothalamic cart2b might play a vital role in appetite regulation, with fasting maybe inducing shutting down hunger. This is in line with observations in Siberian sturgeon (Acipenser baerii) (Zhang et al, 2018), where cart mRNA in whole brain increased after 3-17 days of food deprivation. Interestingly, our finding is contrary to several previous studies that demonstrate the anorectic function of Cart.…”

Nutrient Regulation of Endocrine Factors Influencing Feeding and Growth in Fish

“…In general terms, appetite-stimulating or orexigenic factors, including NPY (85, 86), and orexin (89, 90), have been shown to display periprandial changes characterized by higher expression levels before or at mealtime, and lower levels post feeding, suggesting that they are hunger signals. By contrast, appetite inhibiting or anorexigenic signals, such as CART (91, 92), were found to be mainly upregulated after a meal, thus acting as a postprandial satiety signal.…”

“…In this respect, several central and peripheral appetite regulators are affected by a single meal, showing periprandial fluctuations in their expression and/or secretion levels. Brain hormones showing such changes in fish include NPY (85, 86), orexin (87–90), CART (87, 88, 91, 92), and nesfatin-1 (93). In general terms, appetite-stimulating or orexigenic factors, including NPY (85, 86), and orexin (89, 90), have been shown to display periprandial changes characterized by higher expression levels before or at mealtime, and lower levels post feeding, suggesting that they are hunger signals.…”

The Roles of Neuropeptide Y (Npy) and Peptide YY (Pyy) in Teleost Food Intake: A Mini Review

“…Numerous vital and outlying appetite regulators are affected by a lone meal, displaying prior feeding vacillations in their expression and/or secretion levels. Brain hormones demonstrating such changes in teleost include Npy [9,81], which is of interest in this review; orexin [45,82,87,88]; cocaine-and amphetamine-regulated transcript (CART) [18,[87][88][89]; and nesfatin-1 [90].…”

“…Knowledge about neuroendocrine control on food intake and regulation, including neuropeptide Y (Npy) and peptide YY (Pyy), explicitly concerning their roles, has significantly improved nowadays. Current studies have indicated that these peptides have impacts on the feeding behavior in vertebrates (teleost) [12,14,[16][17][18] either as an orexigenic or anorexigenic factor.…”