<p> Scientists, including one of Indian origin, have for the first time identified a brain hormone that triggers fat burning in the gut, an advance that could have implications for future drug development.<br /><br /></p>.<p>"This was basic science that unlocked an interesting mystery," said Supriya Srinivasan, Assistant Professor at The Scripps Research Institute (TSRI) in the US.<br /><br />Previous studies had shown that the neurotransmitter serotonin can drive fat loss. Yet no one was sure exactly how.<br /><br />Srinivasan and her colleagues experimented with roundworms called C elegans, which are often used as model organisms in biology.<br /><br />These worms have simpler metabolic systems than humans, but their brains produce many of the same signalling molecules, leading many researchers to believe that findings in C elegans may be relevant for humans.<br /><br />Researchers deleted genes in C elegans to see if they may interrupt the path between brain serotonin and fat burning.<br /><br />By testing one gene after another, they hoped to find the gene without which fat burning would not occur. This process of elimination led them to a gene that codes for a neuropeptide hormone they named FLP-7.<br /><br />They found that the mammalian version of FLP-7 (called Tachykinin) had been identified 80 years ago as a peptide that triggered muscle contractions when dribbled on pig intestines.<br /><br />Scientists back then believed this was a hormone that connected the brain to the gut, but no one had linked the neuropeptide to fat metabolism in the time since.<br /><br />The next step in the new study was to determine if FLP-7 was directly linked to serotonin levels in the brain.<br /><br />Lavinia Palamiuc, a TSRI research associate, tagged FLP-7 with a fluorescent red protein so that it could be visualised in living animals, because the roundworm body is transparent.<br /><br />She showed that FLP-7 was indeed secreted from neurons in the brain in response to elevated serotonin levels. FLP-7 then travelled through the circulatory system to start the fat burning process in the gut.<br /><br />"That was a big moment for us," said Srinivasan.<br />For the first time, researchers had found a brain hormone that specifically and selectively stimulates fat metabolism, without any effect on food intake.<br /><br />In the newly discovered fat-burning pathway, a neural circuit in the brain produces serotonin in response to sensory cues, such as food availability.<br /><br />This signals another set of neurons to begin producing FLP-7, which then activates a receptor in intestinal cells, and the intestines begin turning fat into energy.<br /><br />Next, the researchers investigated the consequences of manipulating FLP-7 levels.<br />While increasing serotonin itself can have a broad impact on an animal's food intake, movement and reproductive behavior, the researchers found that increasing FLP-7 levels farther downstream didn't come with any obvious side effects.<br /><br />The worms continued to function normally while simply burning more fat.<br />The study was published in the journal Nature Communications.</p>
<p> Scientists, including one of Indian origin, have for the first time identified a brain hormone that triggers fat burning in the gut, an advance that could have implications for future drug development.<br /><br /></p>.<p>"This was basic science that unlocked an interesting mystery," said Supriya Srinivasan, Assistant Professor at The Scripps Research Institute (TSRI) in the US.<br /><br />Previous studies had shown that the neurotransmitter serotonin can drive fat loss. Yet no one was sure exactly how.<br /><br />Srinivasan and her colleagues experimented with roundworms called C elegans, which are often used as model organisms in biology.<br /><br />These worms have simpler metabolic systems than humans, but their brains produce many of the same signalling molecules, leading many researchers to believe that findings in C elegans may be relevant for humans.<br /><br />Researchers deleted genes in C elegans to see if they may interrupt the path between brain serotonin and fat burning.<br /><br />By testing one gene after another, they hoped to find the gene without which fat burning would not occur. This process of elimination led them to a gene that codes for a neuropeptide hormone they named FLP-7.<br /><br />They found that the mammalian version of FLP-7 (called Tachykinin) had been identified 80 years ago as a peptide that triggered muscle contractions when dribbled on pig intestines.<br /><br />Scientists back then believed this was a hormone that connected the brain to the gut, but no one had linked the neuropeptide to fat metabolism in the time since.<br /><br />The next step in the new study was to determine if FLP-7 was directly linked to serotonin levels in the brain.<br /><br />Lavinia Palamiuc, a TSRI research associate, tagged FLP-7 with a fluorescent red protein so that it could be visualised in living animals, because the roundworm body is transparent.<br /><br />She showed that FLP-7 was indeed secreted from neurons in the brain in response to elevated serotonin levels. FLP-7 then travelled through the circulatory system to start the fat burning process in the gut.<br /><br />"That was a big moment for us," said Srinivasan.<br />For the first time, researchers had found a brain hormone that specifically and selectively stimulates fat metabolism, without any effect on food intake.<br /><br />In the newly discovered fat-burning pathway, a neural circuit in the brain produces serotonin in response to sensory cues, such as food availability.<br /><br />This signals another set of neurons to begin producing FLP-7, which then activates a receptor in intestinal cells, and the intestines begin turning fat into energy.<br /><br />Next, the researchers investigated the consequences of manipulating FLP-7 levels.<br />While increasing serotonin itself can have a broad impact on an animal's food intake, movement and reproductive behavior, the researchers found that increasing FLP-7 levels farther downstream didn't come with any obvious side effects.<br /><br />The worms continued to function normally while simply burning more fat.<br />The study was published in the journal Nature Communications.</p>