Between 30 and 40% of the population have, or are leading toward getting, nonalcoholic fatty liver disease. In a recent Science Advances article, Mayo Clinic researchers show how hungry human liver cells find energy. This study, done in rat and human liver cells, reports on the role of a small regulatory protein that acts like a beacon to help cells locate lipids and provides new information to support the development of therapies for fatty liver disease. While the mechanisms involved in fat accumulation are the usual targets of research for fatty liver disease, clarifying the cell's mechanism for breaking down fat also could provide valuable information to fuel the discovery of breakthrough treatments in the future. ‘When a protein Rab10 is switched on, it will bind to a lipid droplet and cause the autophagosome to dock on the droplet surface, recruit other proteins, and digest the lipid into a free fatty acid energy source.’ Fueling the hungry cell In a well-fed cell, fat deposits, called lipid droplets, are nutritional insurance. They are ignored by the cell as it fuels growth and division via its normal pathway. But, in a starving cell, the normal pathway switches off, and a recycling process, called autophagy, switches on. Autophagy is a way for cells to break down macromolecules, such as protein and fat, into their component parts to be used in cell processes. Under starvation conditions, the cell's recycling pathway directs specialized vessels to engulf lipid droplets. These vessels, called autophagosomes, then link with another organelle, called a lysosome, which is filled with acidic enzymes. When these two merge, the resulting structure is called an autolysosome. Within the autolysosome, the enzymes break apart the fat droplet free fatty acids. How does a hungry cell find the fat? It follows the beacon Zhipeng Li, first author and a student at Mayo Clinic Graduate School of Biomedical Sciences, noticed that, within the hungry cells, one protein, called Rab10, was intimately associated with many of the lipid droplets. Rab proteins operate like switches; when bound to a substance, they switch on and facilitate interactions in the cell. There are more than 60 different Rab switches, or small regulatory GTPases, in the human genome. "In this paper, we show that, when Rab10 is switched on, it will bind to a lipid droplet and cause the autophagosome to dock on the droplet surface, recruit other proteins, and digest the lipid into a free fatty acid energy source," says Li. Dr. Mark McNiven, senior author on the paper and director of Mayo Clinic's Center for Biomedical Discovery explains that cells have sensors that detect low energy levels and respond. "Rab10 switches on and builds up around the lipid droplet," says Dr. McNiven. "Then, the cell activates its lysosomes that then targets these lipid droplets and goes after them. So this was an important step that we provided between the sensing mechanism of starvation and how that is signaling to this switch to go after lipid droplets." Source: Eurekalert << Dysfunctional Medical Equipment Amounts To 34 Percent In Ind... Novel Protein Pathway in Mitochondria Fuels Tumor Progressi... >> Recommended Reading Nonalcoholic Fatty Liver Disease Prevented in Mice To prevent nonalcoholic fatty liver disease - the most common cause of chronic liver disease worldwide - in mice, researchers have discovered a way. READ MORE Gut Microflora Influences the Development of Nonalcoholic Fatty Liver Disease New study provides a link between molecular signaling pathways in the gut, the intestinal microbiome, and development of NAFLD. READ MORE Obese Children With Nonalcoholic Fatty Liver Disease at Greater Risk of High Blood Pressure Researchers have found obese children suffering from nonalcoholic fatty liver disease (NAFLD) are at an increased risk of suffering from high blood pressure. READ MORE Dietary Substitution of Saturated Fats Prevents Nonalcoholic Fatty Liver Disease Scientists have determined that dietary substitution of saturated fats enriched in medium chain triglycerides (MCT) for polyunsaturated fat prevents the development of nonalcoholic fatty liver disease (NAFLD). READ MORE Current Treatments for Liver Cancer Current Treatments for Liver Cancer (also known as hepatoma or hepatocellular carcinoma) can result in complete cure of the disease if it is detected early. READ MORE Fatty Liver Disease: A Growing Health Problem in India Non alcoholic fatty liver disease (NAFLD) is the leading cause of liver dysfunction worldwide and is a rapidly growing health problem in India. READ MORE Hepatitis A Hepatitis A is the most benign of the hepatitis viruses and usually has no long term side effects. Hepatitis A vaccine is available that is 95% effective in preventing the disease. READ MORE Hungry? - But you Just Ate! Most of us are tempted by good food, mealtime or not. Once in a way is fine but it is dangerous to give into food cravings all the time. READ MORE Living Donor Liver Transplant: What Are the Risks? The risk of dying as a result of a living donor liver segment removal is between 0.2-2.0%. The risk of morbidity is anywhere between 1.3% (in highly experienced centers) to 60%. READ MORE Milk Thistle Milk Thistle is a resourceful natural plant which has many medicinal benefits. In herbal medication milk thistle is used in cases of liver diseases. READ MORE Why does your Stomach Growl with Hunger A rumbling, growly stomach, hiccups and continuous sneezing are some of the body’s signals which we don’t have much on. READ MORE Wilson's Disease This is a rare inherited systemic disorder of copper metabolism, affecting the liver mainly before other organs. READ MORE Most Popular on Medindia Drug - Food Interactions Pregnancy Confirmation Calculator Calculate Ideal Weight for Infants More News on: Hepatitis AParkinsons Disease Surgical TreatmentLiverWilson's DiseaseHungry? - But you Just Ate!Why does your Stomach Growl with HungerMilk ThistleCurrent Treatments for Liver CancerFatty Liver Disease: A Growing Health Problem in IndiaLiving Donor Liver Transplant: What Are the Risks?