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  • Appetite Control Central with Hypothalamic Peptides

    The hypothalamus part of the brain is responsible for the biological function of regulating a variety of body functions and responses. It has several important nuclei responsible for the regulation of energy homeostasis and feeding.

    We find the production sites of Luteinizing hormone – LH, the ventromedial hypothalamus – VHM, and the Arcuate Nucleus – ARC. As far as feeding and energy regulation in the body is concerned, the ARC is an integrated center for feeding regulation, VHM of the center of satiety, while the LH is the feeding center. Below is a brief look at some of the central hypothalamus peptides which are chains of amino acids worth knowing about when it comes to appetite control and feeding.

    Neuropeptide Y

    The ARC is the main site of production for the neuropeptide Y. The site is located right within the neurons in the hypothalamus of the brain. Though the production of NPY comes with diverse effects on the behavior and other functions, one of its most pronounced effects on feeding following central administration. NPY synthesis usually happens in the ARC before it is released in the PVN where it is regulated by the inhibitory effects of signaling factors such as insulin, leptin, and glucocorticoids.

    The NYP neurons are always considered as potential hypothalamic targets for peptides, such as leptin. This has made it possible to explain why whenever NPY is released, leptin usually has the ability to induce weight loss and hypophagia. Insulin, on the other hand, has been shown to stop or hinder the synthesis of Leptin and therefore stops one from losing weight, as well as its secretion in PVN.

    Five G-protein when coupled with NPY receptors are believed to be among the vital receptors responsible for mediating the feeding effects of NPY. The expression of Y5 receptors is known to happen at very high levels of LHA, as well as very close to the sites, known to harbor most of the NPY activities with the potential of stimulating feeding.

    Melanin-Concentrating Hormone

    Melanin-concentrating hormone is an orexigenic neuropeptide with 19 amino acids. The peptide is highly expressed in the LH and zona incerta within the hypothalamus, and it has been demonstrated to have very high orexygenic effects when it is infused with ICV. Most of the interests revolving around the mechanisms by which the hormone works have always been centered on the MCH1 receptors found in the nucleus accumbens shell (AcbSh). This shell is believed to play a major role when it comes to motivational aspects of eating.

    Agouti-Gene Related Proteins

    Agouti-gene related protein is a peptide featuring a total of 132 amino acids. The expression of the AgRP happens exclusively in the ARC within the central nervous system, where it then co-localizes with NPY cells in the nucleus. Studies conducted by Rossi et al. suggest that just like NPY, AgRP has orexigenic properties when infused with ICV or directly in DMH or PVN.

    However, it is unique to observe that AgRP functions like an endogenous antagonist of melanocortin-4 and melanocortin-3 receptors. This signifies the high likelihood that AgRP plays a vital role in modulating feeding. Perhaps AgRP plays more vital roles during conditions of high energy requirements, such as during lactation or even pregnancy.

    Hypocretins/orexins

    The hypocretins 1 & 2, also known as orexins A & B, are produced in the cell bodies of the LH area, and they are known to be excitatory neuropeptides with extensive projections to very many regions. They usually bind to orexin receptors 1 and 2, which are usually produced from two separate genes. The two receptors have different distribution patterns within the hypothalamus, though OX1 has shown a high amount of expression in the PVN.

    It should be noted that orexins fall under the category of appetite-stimulating neuropeptides. They are highly expressed in the LH and the DMH. Also, orexin-containing neuronal fibers have been spotted distributed in several nuclei, with very high projections in the ARC. Orexin-containing neurons may also project to NPY-containing neurons.

    Additionally, studies suggest that orexins can increase the concentration of cytosolic Ca2+ in NPY neurons obtained from ARC. This result is a subtle indication that NPY neurons may transmit excitatory signals from neurons containing orexin. It should also be noted that the distribution of these two neurons, is very different within the hypothalamus. OX2R is mostly expressed in the PVN, while OX1R is mostly expressed in the VMH of the hypothalamus.

    Cerelbellin1

    Cerelbellin1 – Cbln1, shows high expression in the hypothalamus. When administered through ICV, it was perceived that the Cbln1 increases food intake, as well as increasing the release of NPY from the hypothalamus, besides reducing the levels of plasma thyroid-stimulating hormone. It has also been observed that the Cbln1 mRNA expression levels in the ventromedial nucleus in the hypothalamus went high in rats that were subjected to fasting. These results subtly indicate that Cbln1 may act as a novel orexigenic peptide.

    how hypothalamic peptides are responsible for controlling one's appetite.

    Galanin

    Galanin is a C-terminally amidated 29-amino acid peptide found in the gut and the brain. The peptide is known to co-exist with others such as NPY, 5-hydroxytryptamine, noradrenaline, and GABA in several areas of the brain. It is in the PVN, ARC, and the supraoptic nucleus of the hypothalamus, where we largely find the hypothalamic galanin neurology. Most of the galanin-positive neurons and galanin positive-fibers have been demonstrated in several studies in the dorsal vagal complex.

    This suggests that galanin can produce its effects when associated with the vagal neurons. The major source of galanin terminals, is usually the nucleus of the solitary tract within the dorsal vagal complex. It is believed that the peptide galanin plays a huge role in learning, feeding, memory, pain threshold, inflammation, insulin regulation, sex behavior, and the regulation of the pituitary hormone release. It has been reported that the acute administration of galanin usually leads to an increase in fat consumption.

    Galanin-Like Peptides

    Galanin-like peptide, also known as GALP, is a novel peptide with 60 amino acids, with between 9 and 21 of the amino acids being identical to the biologically active N-terminal, part of galanin. In hybridization studies done in situ, it was observed that GALP mRNA, is highly expressed within the periventricular regions of the ARC, as well as in the pituitary glands of the study rats. NPY with axon terminals were also observed to be closely apposed to neurons containing GALP present in the ARC.

    Additionally, studies conducted by Cunningham et al. involving double-label in situ hybridization, showed neurons containing GALP in the macaque expressed NPY receptor. This was an indication that NPY has the potential of regulating GALP neurons present in the ARC.

    Melanocortins

    Melanocortins are bioactive peptides obtained from the precursor molecule POMC through a very specific tissue post-translation cleavage process. The POMC gene usually demonstrated relatively significant levels in various mammalian tissues including the hypothalamic neurons, the immune system, the skin, and the pituitary glands among others. The effects of most products obtained from POMC through any tissue, is usually a factor of the various specificities that relate to the convertases found in the present tissue.

    Alpha-melanocytes-stimulating hormone is produced by the intermediate lobe of the pituitary glands, and it is the peptide responsible for activating melanocortin, MC3, and MC4 receptors, which, in turn, are responsible for inhibiting food intake.

    The MC3 and MC4 receptors are present in most of the areas that are known to be responsible for regulating the energy balance, as well as in regions such as the hippocampus and the cerebral cortex. Most of the bioactive peptides that are from the hypothalamic neurons may sometimes behave like endogenous ligands for melanocortin.

    Glucagon-Like Peptides

    The brain releases GLP-1 hormones within the nucleus of the NTS. After the release of the hormone, it is then projected to the PVN, resulting in the activation of GLP-1 receptors – these are some of the receptors which are responsible for promoting anorexia and feelings of satiety.

    The activated neurons can also be projected to the ARC where it may be responsible for moderating the outflow to the pancreas of the vagal motor, leading to an increase in the secretion of insulin, while at the same time suppressing the release of glucagon.

    The result of this action is a lowered blood glucose level. Some studies also suggest that it may be possible for systematic GLP-1 to get to the brain through leaks that may occur in the BBB like through the subfornical organ, as was shown in studies involving rats.

    When GLP-1 is administered intravenously to normal weight, and obese human beings, it is noted that there is a decrease in food intake if the administration is done in a dose-dependent manner, and also through gastric emptying. These results are suspected to be through brainstem and vagal pathways. This is because the peripheral administration of GLP-1 usually ends up activating neurons within the brainstem in rats.

    It has been observed that there exists a perfect overlap between GLP-1 and GLP-2 within the central nervous system in the distribution of the co-localized peptides. The highest concentration is normally seen in the diffuse ventral part of the dorsomedial nucleus.

    Following the injection of the peptide into the lateral ventricle, it was observed that some of the effects were inhibitory in nature regarding feeding. It has also been observed that GLP-2 displays both behavioral and pharmacological effects on feeding. The GLP-2 released from the central nervous system is vital when it comes to controlling the feed behavior.

    When Glp-2r is deleted from POMC neurons, it is noticed that there is an increase in food intake, which comes in the form of meal frequency amplification, as well as an increase in gastric emptying. This suggests that the GLP-2 produced within the central nervous system is an important signal for satiety for short term control of feeding, as well as gastric motility.

    It also suggests that the peptide may affect the long term homeostatic control of the balance of the energy within the body system. Also, when GLP-2 is activated, it is observed that it can potentially suppress food intake and promote gastric emptying with the help of the MC4R signaling pathway.

    Studies conducted by Guan et al. demonstrate that the process of gastric emptying is vital for the short-term control of feeding. The studies also suggest that suppression of food intake through mediation by POMC neurons may be possible through decelerating gastric emptying.

    Corticotropin-Releasing Factor

    Corticotropin-releasing Factor, CRH, is a peptide with 42 amino acids. It is a mammalian neurohormone that is associated with some major functions of the brain, such as the physiological regulation of ACTH within the pituitary glands. The hormone is highly expressed in the PVN neurons. Studies show that when the hormone is injected centrally, it can inhibit the intake of food while at the same time reducing the body weight in the model rats used in the study.

    When administered peripherally, studies show that the hormone will increase the amount of energy used in the body, as well as the rates of fat oxidation in human beings. It has also been observed that infusion of leptin with the hormone stimulates its expression, and when it is used as a pretreatment as an antagonist attenuate, it also leads to reduced intake of food, as well as body weight.

    Neurotensin

    Neurotensin, also known as NT, is produced in the ARC of the hypothalamus. It is a 13-amino acid peptide whose injection into the PVN has been shown to drastically decrease food intake. The neurons of the peptides seem to play a huge role further along in the functions of leptin.

    When ICV leptin is infused with PVN, there is increased synthesis of NT, which leads to a reduction in food intake. These results further help to suggest that the actions of leptin may be partly mediated by NT hormone.

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    References

    1. Holst JJ. The physiology of glucagon-like peptide 1. Physiol Rev (2007) 87(4):1409–39. doi:10.1152/physrev.00034.2006
    2. Tang-Christensen M, Vrang N, Larsen PJ. Glucagon-like peptide containing pathways in the regulation of feeding behaviour. Int J Obes Relat Metab Disord (2001) 25(Suppl 5):S42–7. doi:10.1038/sj.ijo.0801912
    3. Torekov SS, Madsbad S, Holst JJ. Obesity – an indication for GLP-1 treatment? Obesity pathophysiology and GLP-1 treatment potential. Obes Rev (2011) 12(8):593–601. doi:10.1111/j.1467-789X.2011.00860.x
    4. Janssen P, Rotondo A, Mule F, Tack J. Review article: a comparison of glucagon-like peptides 1 and 2. Aliment Pharmacol Ther (2013) 37(1):18–36. doi:10.1111/apt.12092
    5. Le Quellec A, Kervran A, Blache P, Ciurana AJ, Bataille D. Oxyntomodulin-like immunoreactivity: diurnal profile of a new potential enterogastrone. J Clin Endocrinol Metab (1992) 74(6):1405–9. doi:10.1210/jc.74.6.1405
    6. Chaudhri OB, Parkinson JR, Kuo YT, Druce MR, Herlihy AH, Bell JD, et al. Differential hypothalamic neuronal activation following peripheral injection of GLP-1 and oxyntomodulin in mice detected by manganese-enhanced magnetic resonance imaging. Biochem Biophys Res Commun (2006) 350(2):298–306. doi:10.1016/j.bbrc.2006.09.033
    7. Cohen MA, Ellis SM, Le Roux CW, Batterham RL, Park A, Patterson M, et al. Oxyntomodulin suppresses appetite and reduces food intake in humans. J Clin Endocrinol Metab (2003) 88(10):4696–701. doi:10.1210/jc.2003-030421
    8. Wynne K, Park AJ, Small CJ, Patterson M, Ellis SM, Murphy KG, et al. Subcutaneous oxyntomodulin reduces body weight in overweight and obese subjects: a double-blind, randomized, controlled trial. Diabetes (2005) 54(8):2390–5. doi:10.2337/diabetes.54.8.2390
    9. Lee MC, Schiffman SS, Pappas TN. Role of neuropeptides in the regulation of feeding behavior: a review of cholecystokinin, bombesin, neuropeptide Y, and galanin. Neurosci Biobehav Rev (1994) 18(3):313–23. doi:10.1016/0149-7634(94)90045-0
    10. Kirkham TC, Gibbs J, Smith GP, Geary N. Meal pattern analysis in rats reveals partial agonist activity of the bombesin receptor antagonist BW2258U89. Pharmacol Biochem Behav (1995) 52(1):101–6. doi:10.1016/0091-3057(95)00044-W
  • What You Need to Know About Peptides and Food Intake

    The mechanisms involved with the regulation of food intake in the body, mainly feature the combined work of the brain, the adipose tissues, and the gut, among the top organs. Systems such as sympathetic, and parasympathetic among others, are also necessary for proper communication between the brain and satiety center, the adipose tissue, and the gut.

    Think of these as neuronal circuits that also feature a variety of hormones and chains of amino acids, as well as other appetite inhibitors – a clear indication of the importance of physiology when it comes to the regulation of food intake and energy homeostasis in the human body.

    Nutrients obtained from food through the process of digestion are believed to be responsible for activating G-protein coupled receptors, but this is an activity that happens only in the luminal side of the enteroendocrine cells, such as the L-cells.

    This action usually stimulates the gut to release natural amino acids and peptide hormones such as glucagon-like-peptide, peptide tyrosine, pancreatic polypeptide, and cholecystokinin into the circulation system. These are some of the hormones that are very well known to inhibit or suppress appetite, by making you feel satiated most of the time.

    One of the peptides secreted from the stomach is ghrelin, and unlike most of the hormones produced by the gut system, its levels in the plasms are always known to decrease after the consumption of a meal. Insulin and leptin are other circulating factors that are responsible for relaying information about long-term energy stores.

    The circulation of these two hormones is always in proportion to the body fat content, and they are also known to enter the central nervous system proportional to their plasma levels, hence, helping to reduce food intake.

    It is believed that circulating hormones have the potential of influencing the functions of the arcuate nucleus neurons present in the hypothalamus section of the brain. It is also known that circulating factors such as gut hormones may also have an influence on the nucleus of the tractus solitarius via the neighboring circumventricular organ.

    The arcuate nucleus, ARC, may sometimes work as an integrative center with two of the most important subpopulations of neurons responsible for influencing appetite, which usually leads to increased food intake. One of the subpopulations is Y and agouti-related protein – AgRP, while the other one is pro-opiomelanocortin (POMC).

    Both are known to inhibit food intake, and can always project to areas that are responsible for regulating food intake, including regions such as the hypothalamic paraventricular nucleus, which normally receives important appetite information from other hypothalamic nuclei.
    Below is a detailed look at some of the peptides at the core of food intake and digestion, as well as their specific functions of digestion.

    Ghrelin

    Ghrelin is an orexigenic peptide that contains a total of 28 amino acids. The peptide is present in X/A-like cells – these cells are responsible for about 20% of all the cells within the endocrine cell population. Ghrelin-immunoreactive cells can also be found in places such as the colon, ileum, jejunum, and duodenum. The concentration of this hormone is known to decrease gradually as one moves from the duodenum towards the colon.

    The peptide can also be secreted by other organs with the major ones being the pancreas and the hypothalamus sections of the brain. There are many factors known to regulate the production of ghrelin, and feeding is one of the best-known factors when it comes to the regulation of ghrelin. It has been noted that the concentration of plasma ghrelin usually spike during fasting, and will decrease upon food intake.

    The specific factors that are responsible for this kind of regulation, however, are yet to be discovered. One of the highly suspect candidates, is the blood glucose level, hence, the administration of glucose may decrease the concentration of ghrelin in the plasma.

    With the localization of ghrelin receptors on vagal afferent neurons in the rat ganglion cells, it is suggested that the hormone may be responsible for sending signals between the stomach and the brain through the vagus nerve. In short, the hormone is primarily produced in the stomach, as a response to starvation and hunger.

    Once produced in the stomach in response to starvation and hunger, it then gets into the bloodstream where it works as a peripheral signal, communicating to the central nervous system through the vagus nerve, which then, stimulates feeding.

    Neurons with ghrelin have also been found in the ARC of the hypothalamus – this is one of the regions responsible for regulating appetite. In some studies, it was observed that intracerebroventricular (ICV) injection of ghrelin leads to an overall increase in the cumulative food intake, and an overall decrease in energy expenditure. This led to an overall increase in body weight gain. For the stimulation of the release of the orexigenic peptides, neurons containing ghrelin has to send efferent fibers onto AgRP-expression neurons.

    To reduce or suppress the release of orexigenic peptides, on the other hand, ghrelin-containing neurons must send fibers onto the POMC neurons. The ARC is usually a target of leptin – leptin is one of the leading appetite-suppressing hormones usually produced in the AT. Leptin has the ability to limit the appetite-stimulating effects of both AgRP and NPY.

    Hypothalamic ghrelin, on the other hand, can prevent leptin-induced feeding. This is a subtle indication that leptin and ghrelin have a competitive nature of interaction when it comes to the regulation of feeding.

    Ghrelin is just a hunger signal produced from the peripheral tissues. Subcutaneous and intravenous injections of ghrelin may therefore lead to an increase in food intake, while peripheral injection of the same may lead to the stimulation of the hypothalamic and ultimately lead to an increase in food intake. Since the rate at which the peripheral ghrelin goes through the BBB is very slow, peripheral ghrelin is necessary when it comes to the activation of the appropriate hypothalamic regions through yet to be identified indirect pathways.

    What You Need To Know About Peptides and Food Intake

    Peptide Tyrosine

    Peptide tyrosine is another anorexigenic peptide that features 36 amino acids, several tyrosine residues, and it must have a c-terminal amidation for it to be biologically active. Low levels of PYY have always been recorded in the enteroendocrine cells present in the stomach, and these levels are known to increase proportionally as one moves towards the small and the large intestines, with the peak levels being realized at the colon and the rectum.

    The L-cells present in the lining of the distal gastrointestinal tract is responsible for releasing PYY and this is usually done in accordance with the caloric intake. It has always been noted that the plasma levels of this peptide will usually go up within 30 minutes after the consumption of a meal.

    It has also been observed that meals containing high levels of protein, usually lead to the greatest increase in levels of PYY, in comparison to other micronutrients. The anorectic properties of PYY seem to be regulated centrally through the ARC.

    Pancreatic Polypeptide

    Pancreatic polypeptide – PP, contains a total of 36 amino acids that all belong to the PP-fold family of peptides. It is normally released post-prandially by the islet PP cells of the pancreas, but under vagal control. The peptide can be compared to other anorectic intestinal peptides like the PYY, which is usually secreted in proportion to caloric intake.

    The pancreatic polypeptide has the ability to bind to all the members of the Y receptor family, though they are also known to have the highest affinity for the Y-4 receptor subtype. Some of the effects of the pancreatic polypeptide are believed to be influenced by the ventromedial hypothalamus, and the paraventricular hypothalamus parts of the brain. These two parts are vital when it comes to the control of appetite in the body.

    Bombestin

    This is a tetradecapeptide obtained from the skin of amphibians, and it shares a similar structure to mammalian gastrin-released peptide – GRP and neuromedin B. When bombestin is administered in conjunction with GRP, there is always a decrease in food intake in persons with normal weight, but the same is never the case with obese women.

    When bombestin is administered peripherally or through central injection, it has the potential to reduce food intake that is not subject to being blocked by vagotomy. The peptide can also activate the sympathetic nervous system. In studies involving animals that have been starved, or those with ventromedial hypothalamic lesions, it was observed that the peptide could lead to a decline in temperature. This is because it is never possible to activate the sympathetic nervous system under such conditions.

    Insulin

    Insulin is usually produced in the islet cells of the Langerhans present in the pancreas. Insulin usually accesses the brain through the blood circulation system acting through the hypothalamic neuron present in the ARC. There is also specific insulin transport available through the BBB. This is usually regulated by a saturable mechanism that features certain specific insulin receptors located in the brain’s microvessels.

    The systematic injection of insulin or ICV infusion may sometimes result in a dose-dependent suppression of appetite and food intake in general. The central actions of insulin are also known to sometimes promote anorexia, since it usually decreases the expressions of both POMC and NPY.

    Both leptin and insulin can activate POMC neurons, but their effects when it comes to regulating AgRP, seems to be different – leptin inhibits its synthesis, while insulin is known to stimulate the synthesis. A decrease in NPY usually leads to insulin deficiency, while the administration of insulin usually inhibits hypothalamic NPY expression.

    Cholecystokinin

    Cholecystokinin – CCK, is also released post-prandially, but also from the small intestines. Studies show that it can co-localize with the PYY that are usually found in the L-cells. Its release is usually a response to saturated fats, amino acids, and other small peptides that are always a result of protein digestion. CCK2 receptors have also been recorded in peripheral tissues, with higher concentration being noticed in tissues such as the vagal afferent nerve fibers, gall bladder, and the pancreas.

    Also, CCK1 receptors have been detected in certain areas where the central nervous system is involved with the regulation of food intakes such as in the dorsomedial hypothalamus, AP, and the NTS. CCK2 receptors, on the other hand, portrays a very different distribution.
    They are present in the vagal afferent, hypothalamus, and gastric mucosa, among others. They have also been featured in several areas that are usually involved with the regulation of appetite. In human beings, the intravenous administration of CCK is known to reduce food intake and has also been shown to increase the perception of being full.

    Oxyntomodulin

    Oxyntomodulin is a peptide with a total of 37 amino acids. It is usually released post-prandially from the L-cells, with the amount released being proportional to the caloric intake. OXM is known to cause a reduction in some of the neuronal activities witnessed in regions such as PVN, and ARC, as well as the supraoptic nucleus.

    This system of activation is known to be very different from that of GLP-1 when they are exposed to the same conditions. It simply means that these hormones work through different hypothalamus pathways. Oxyntomodulin may reduce food intake in persons with normal weight, and there is also evidence that it may increase energy expenditure in humans.

    Amylin

    Amylin is a peptide with a total of 37 amino acids. It is also known as islet amyloid polypeptide. The peptide is usually co-released with insulin from pancreatic beta-cells in mammals as a response to food intake. The peptide seems to decrease food intake by using both peripheral and central mechanisms and, may, indirectly, slow down the process of gastric emptying.

    The AP is known to play a very major role when it comes to the satiating effects of peripheral amylin. This usually comes with the direct activation of the AP neurons by blood-borne amylin. Its anorectic effects may sometimes be a result of the reduced expression of the orexigenic neuropeptides present in the LH area. Some studies have evidence that suggests that Amylin may also be able to express its effects through dopaminergic, histaminergic, and serotonergic systems.

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    As a peptide research company, we have a customer service department that you can call for quality peptides to conduct your own research. We can also synthesis peptides if you do not see any in our peptide catalog.

    References

    1. Zhou A, Bloomquist BT, Mains RE. The prohormone convertases PC1 and PC2 mediate distinct endoproteolytic cleavages in a strict temporal order during proopiomelanocortin biosynthetic processing. J Biol Chem (1993) 268(3):1763–9.
    2. Pritchard LE, Turnbull AV, White A. Pro-opiomelanocortin processing in the hypothalamus: impact on melanocortin signalling and obesity. J Endocrinol (2002) 172(3):411–21. doi:10.1677/joe.0.1720411
    3. Verdich C, Flint A, Gutzwiller JP, Naslund E, Beglinger C, Hellstrom PM, et al. A meta-analysis of the effect of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake in humans. J Clin Endocrinol Metab (2001) 86(9):4382–9. doi:10.1210/jc.86.9.4382
    4. Naslund E, Bogefors J, Skogar S, Gryback P, Jacobsson H, Holst JJ, et al. GLP-1 slows solid gastric emptying and inhibits insulin, glucagon, and PYY release in humans. Am J Physiol (1999) 277(3 Pt 2):R910–6.
    5. Nauck MA, Niedereichholz U, Ettler R, Holst JJ, Orskov C, Ritzel R, et al. Glucagon-like peptide 1 inhibition of gastric emptying outweighs its insulinotropic effects in healthy humans. Am J Physiol (1997) 273(5 Pt 1): E981–8.
    6. Imeryuz N, Yegen BC, Bozkurt A, Coskun T, Villanueva-Penacarrillo ML, Ulusoy NB. Glucagon-like peptide-1 inhibits gastric emptying via vagal afferent-mediated central mechanisms. Am J Physiol (1997) 273(4 Pt 1): G920–7.
    7. Kinzig KP, D’Alessio DA, Seeley RJ. The diverse roles of specific GLP-1 receptors in the control of food intake and the response to visceral illness. J Neurosci (2002) 22(23):10470–6.
    8. Guan X, Shi X, Li X, Chang B, Wang Y, Li D, et al. GLP-2 receptor in POMC neurons suppresses feeding behavior and gastric motility. Am J Physiol Endocrinol Metab (2012) 303(7):E853–64. doi:10.1152/ajpendo.00245.2012
    9. Beck B, Stricker-Krongrad A, Richy S, Burlet C. Evidence that hypothalamic neurotensin signals leptin effects on feeding behavior in normal and fat-preferring rats. Biochem Biophys Res Commun (1998) 252(3):634–8. doi:10.1006/bbrc.1998.9712
    10. Sahu A. Evidence suggesting that galanin (GAL), melanin-concentrating hormone (MCH), neurotensin (NT), proopiomelanocortin (POMC) and neuropeptide Y (NPY) are targets of leptin signaling in the hypothalamus. Endocrinology (1998) 139(2):795–8. doi:10.1210/en.139.2.795
    11. Kanai Y, Tanuma S. Purification of a novel B cell growth and differentiation factor associated with lupus syndrome. Immunol Lett (1992) 32(1):43–8. doi:10.1016/0165-2478(92)90197-V
    12. Barnikol-Watanabe S, Gross NA, Gotz H, Henkel T, Karabinos A, Kratzin H, et al. Human protein NEFA, a novel DNA binding/EF-hand/leucine zipper protein. Molecular cloning and sequence analysis of the cDNA, isolation and characterization of the protein. Biol Chem Hoppe Seyler (1994) 375(8):497–512. doi:10.1515/bchm3.1994.375.8.497
    13. Miura K, Titani K, Kurosawa Y, Kanai Y. Molecular cloning of nucleobindin, a novel DNA-binding protein that contains both a signal peptide and a leucine zipper structure. Biochem Biophys Res Commun (1992) 187(1):375–80. doi:10.1016/S0006-291X(05)81503-7
    14. Oh IS, Shimizu H, Satoh T, Okada S, Adachi S, Inoue K, et al. Identification of nesfatin-1 as a satiety molecule in the hypothalamus. Nature (2006) 443(7112):709–12. doi:10.1038/nature05162
  • Cell-penetrating Peptides and their Therapeutic Potential

    Cell-penetrating peptides, also known as CPP, have the ability to cross plasma membranes. Ever since the discovery of this ability, it has been exploited for a variety of applications, including delivering bioactive molecules to stop the actions of diseases producing cellular mechanisms.

    Through the selective delivery of drugs into the target cells, it is possible to achieve improved drug distribution, as well as a significant reduction of dosing and toxicity. In this review, we will look at some of the challenges being encountered in this specific field of application, as well as some of the factors that may influence the efficacy of the delivery.
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  • Peptides as the Next Generation Solution for Anti-Infectives

    The presence of large-scale manufacturing and advanced synthesis technologies have currently made it possible for the production of even the most complex peptide anti-infectives.

    With the possibility of this class of molecules being seen as the next-gen of infectives, safe anti-microbial, as well as with a better understanding of pharmacology and biology, it is just a matter of time before we see the introduction into clinical trials for these promising drug candidates.

    This is a vital step in the history and life cycle of peptide anti-infectives and it is one of the strongest indications that the therapeutic and commercial potential of the anti-infectives, is about to be achieved.
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  • The Development and Use of Peptides as Therapeutics

    Peptides refer to biologically active molecules that contain at least two amino acids, interlinked by a peptide bond. Unlike large proteins, they are small in size and a typical chain will usually not go past 100 amino acids.

    Since peptides are highly selective and also known to have relatively safe characteristics, their pharmacological profiles have always appealed to the research world. They are readily available in the human body where they play diverse biological roles.

    For most applications, they mainly act as regulatory and signaling molecules in various physiological processes. Back in the day, the instability of peptides limited their use in the design and development of human drugs, but due to technological breakthroughs, the instability challenges have all been overcome, greatly increasing the broad application of peptides.
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  • The Use of Therapeutic Peptides in Cancer Treatments

    Cancer and cardiovascular diseases are among the major causes of death in most developed countries. Most of the conventional approaches to treating cancer are quickly losing their therapeutic relevance due to the lack of tumor selectivity, drug resistance, and solubility. As such, there is a great need for the development of new therapeutic agents and treatment plans. Over the years, therapeutic peptides have provided a glimmer of hope, and they are currently being considered as a novel approach to treating a variety of diseases, including various forms of cancer.

    This is because they come with a variety of advantages over normal proteins and antibodies. Some of these advantages include easy synthesis, high target selectivity, and specificity, and very low toxicity. They, however, have some drawbacks, with their stability and short half-life being among major concerns. In this piece, we will be looking at some of the therapeutic peptides receiving the most attention currently and some of the strategies being used to overcome some of the peptide limitations.
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  • Promising Cancer Therapies With Peptide-Based Treatments

    What are Peptides and How are They Used?

    Peptides are molecules consisting of various chains of amino acids joined by peptides bonds through the process of a dehydration-condensation reaction. There are various places, or various origins of peptides, including but not limited to direct synthesis by the body, artificial synthesis, or through processes such as proteolysis. They play a huge role in the treatment of a variety of diseases, and they are currently at the center stage in the development of various types of vaccines and for the use of targeted therapy.
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  • Interesting Findings About Peptide Immunotherapeutics

    The development of peptide vaccines has been in the works for a very long time, but with minimal success. However, current advancements in medical technology, as well as an increased understanding of the immune system – more specifically the operations of the antigenic epitopes in stimulating an immune response, have opened a whole new field and made the development of peptide vaccines possible.

    Peptide-based vaccines – technically known as epitope ensemble vaccines, are viewed as a viable alternative approach to the discovery and development of not just targeted therapy but also prophylactic vaccines.
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  • Peptides as Therapeutic Agents for Inflammatory-Related Diseases

    An inflammation is the body's normal response to lesions and infections. The immune system cells move to the site of the injury or infection, and cause an inflammation. To treat this disorder, unspecific small molecule drugs are used, which may cause some side effects.
    The inflammation produces mediators such as cytokines, interleukins, and growth factors. It is necessary to regulate the inflammation to stabilize or heal the damaged cells or tissues.

    A lot of research is being made, and peptides have been used as an alternative anti-inflammatory therapy. Actually, peptides are considered effective compounds, and show an innovative strategy by stopping, diminishing, and/or changing the expression and activity of mediators.
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  • What are the benefits of peptides in cosmetics ?

    The cosmetic industry represents a huge worldwide sector. Between skincare, makeup, and haircare, it is growing faster than most other industries, and its market value is estimated to be worth almost $805 billion by 2023.

    The key to this evolution is innovation. Every brand tries to create new products with new compositions in order to target a maximum of people. More and more people are very careful about each product’s contents, which is why brands always have to conduct lots of research and find a way to make the perfect product, containing the best natural elements possible.
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