Asprosin: The Fasting Hormone Shifting Metabolic Gears

Imagine a tiny messenger, springing into action when your body is running on empty, directing your liver to churn out glucose and even whispering to your brain to make you thirsty. This isn't science fiction; it's the intriguing reality of asprosin, a peptide hormone that's captivating researchers with its multifaceted roles in metabolism and beyond. From regulating blood sugar to influencing hydration and even impacting organ health, asprosin is proving to be far more than just a simple energy manager.

What is Asprosin?

Asprosin is a protein hormone secreted primarily by white adipose tissue (fat cells) during periods of fasting (PMID 27087445). It circulates at nanomolar levels (PMID 27087445). Chemically, it's the C-terminal cleavage product of profibrillin (PMID 27087445, PMID 36630758). While fibrillin-1 is well-known for its role in extracellular matrix and connective tissue elasticity, asprosin's unique metabolic functions suggest it might be generated independently from an internal promoter within the fibrillin-1 gene, allowing for separate regulation (PMID 36630758). This little molecule acts as a crucial signal for the body's energy balance.

Why researchers are excited

The scientific community is buzzing about asprosin because it appears to be a central player in several critical physiological processes, with implications for widespread metabolic conditions. Its involvement in glucose regulation makes it a potential target for metabolic disorders like type II diabetes (PMID 27087445). Beyond that, its connections to fatty liver disease (MASLD), polycystic ovary syndrome (PCOS), and even kidney dysfunction in diabetes are opening entirely new avenues of research (PMID 40231957, PMID 38285626, PMID 40859912). The discovery that it can modulate thirst also hints at an expanded role in fundamental bodily functions not previously associated with metabolic hormones (PMID 38987435). Its varied impacts suggest that understanding asprosin could lead to novel approaches for diagnosing and managing a spectrum of health challenges.

What the studies found

Researchers have uncovered a fascinating array of asprosin's actions across different biological systems:

| Study | Model | Key finding | PMID | |---|---|---|---| | Hormonal changes in PCOS | Human (PCOS women) | Asprosin is among the hormones whose alterations in PCOS may reveal novel diagnostic/treatment targets. | 38285626 | | Asprosin, a Fasting-Induced Glucogenic Protein Hormone | Human, Mouse | Asprosin is a fasting-induced glucogenic protein hormone; elevated in insulin resistance. | 27087445 | | Asprosin-FABP5 Interaction Modulates Mitochondrial Fatty Acid Oxidation | Human (MASLD patients), Mouse | Plasma asprosin levels are significantly elevated in MASLD patients and animal models; hepatocyte-specific asprosin overexpression impairs mitochondrial fatty acid β-oxidation. | 40231957 | | OLFR734 Mediates Glucose Metabolism as a Receptor of Asprosin | Mouse | The olfactory receptor OLFR734 acts as a receptor for asprosin to modulate hepatic glucose production; OLFR734 knockout mice showed improved insulin sensitivity. | 31230984 | | The cerebellum modulates thirst | Mouse | Asprosin activates cerebellar Purkinje neurons, leading to enhanced thirst; deletion of Purkinje neuron-specific asprosin receptor (Ptprd) reduced water intake. | 38987435 | | Asprosin Aggravates Tubular Epithelial Cell Injury | Mouse (DKD), HK2 cells | Asprosin is up-regulated in DKD mice and linked to kidney dysfunction; elevated asprosin impairs mitochondrial dynamics and function in TECs and HK2 cells. | 40859912 | | Asprosin as a regulator of hepatic lipogenesis | Human, Mouse (DIO), Cultured hepatocytes | Asprosin reduced lipogenic gene expression and increased fatty acid oxidation in cultured hepatocytes; in DIO mice, asprosin-treated mice showed reduced lipid accumulation. | 41061856 |

Asprosin has been shown to modulate hepatic glucose release, activating the G protein-cAMP-PKA pathway in the liver (PMID 27087445). In human patients and mice with insulin resistance, plasma asprosin levels are pathologically elevated (PMID 27087445). Loss of asprosin function through immunologic or genetic means has demonstrated profound glucose- and insulin-lowering effects in animals, secondary to reduced hepatic glucose release (PMID 27087445).

Beyond glucose, asprosin has also been implicated in metabolic dysfunction-associated steatotic liver disease (MASLD). In human MASLD patients and animal models, plasma asprosin levels are significantly elevated, and its expression increased in the liver of MASLD mice (PMID 40231957). Hepatocyte-specific overexpression of asprosin impaired mitochondrial fatty acid β-oxidation (FAO), while its knockdown in mice not only enhanced FAO but also compensated for fenofibrate's limitations in MASLD treatment (PMID 40231957). Interestingly, another study found that in cultured hepatocytes, asprosin *reduced* the expression of lipogenic genes and *increased* those of fatty acid oxidation and mitochondrial activity (PMID 41061856). In mice with diet-induced obesity (DIO), asprosin-treated mice showed reduced lipid accumulation and improved metabolic parameters (PMID 41061856). Circulating asprosin levels were also positively correlated with liver steatosis severity in humans (PMID 41061856). These seemingly contradictory findings highlight the complex and context-dependent nature of asprosin's roles.

Its reach extends even further into surprising territories: the brain and kidneys. In mice, asprosin activates cerebellar Purkinje neurons, leading to enhanced thirst, and specific deletion of its receptor (Ptprd) in these neurons resulted in reduced water intake (PMID 38987435). In the context of diabetic kidney disease (DKD), asprosin was found to be up-regulated in DKD mice and positively correlated with kidney dysfunction (PMID 40859912). Elevated asprosin negatively impacted renal tubular epithelial cells (TECs) and impaired mitochondrial dynamics and function in both DKD mice and HK2 cells (PMID 40859912). Genetic manipulation in animals, such as adipose tissue-specific asprosin deficiency or intervention with an asprosin antibody, significantly alleviated kidney injury and mitochondrial dynamics disorder in DKD models (PMID 40859912).

How it's thought to work

Asprosin's mechanisms are a puzzle researchers are actively piecing together. In the liver, it's known to activate the G protein-cAMP-PKA pathway, which drives the rapid release of glucose into the circulation (PMID 27087445). This action is mediated, at least in part, by the olfactory receptor OLFR734, which has been identified as a receptor for asprosin (PMID 31230984). In mice, OLFR734 knockout blunted asprosin's effects on cAMP levels and hepatic glucose production, leading to improved insulin sensitivity (PMID 31230984).

For MASLD, research suggests a complex interplay. One study found that asprosin interacts with FABP5 (fatty acid binding protein 5), facilitating its abnormal nuclear localization (PMID 40231957). Asprosin then directly bound to and inhibited peroxisome proliferator-activated receptor elements (PPREs), negatively regulating PPARα transcriptional activity and disrupting hepatic fatty acid β-oxidation pathways (PMID 40231957). However, another study on hepatic lipogenesis suggests asprosin may reduce lipogenic gene expression and boost fatty acid oxidation in cultured hepatocytes, and improve lipid accumulation in diet-induced obese mice (PMID 41061856), indicating a nuanced role that might depend on the specific metabolic context or disease stage.

In the brain, asprosin signals through the Ptprd receptor on cerebellar Purkinje neurons to modulate thirst (PMID 38987435). In diabetic kidney disease, asprosin is thought to promote excessive SUMOylation of a protein called Drp1, which in turn reduces Drp1 degradation and disrupts mitochondrial dynamics homeostasis in renal tubular epithelial cells (PMID 40859912). This effect can be influenced by proteins like PIAS1 or SENP1 (PMID 40859912).

The catch: what we still don't know

While the findings on asprosin are incredibly exciting, the research is still in its early stages. Many of the studies demonstrating its mechanisms and effects have been conducted in animal models or cell cultures, and more human trials are needed to fully understand its implications for human health. The seemingly dual roles in lipid metabolism (inhibiting FAO in one MASLD study versus reducing lipogenesis and increasing FAO in another) require further clarification. The exact regulatory mechanisms controlling asprosin production and secretion, especially the potential for an independent mRNA generation from the fibrillin-1 gene, are still being explored (PMID 36630758). Further research is necessary to confirm asprosin's precise roles, develop targeted interventions, and ensure their safety and efficacy in humans.

Keep exploring

The journey to uncover the full potential of asprosin is just beginning! This fascinating peptide hormone promises to be a significant player in our understanding of metabolic health, thirst regulation, and various disease states. As researchers continue to unravel its intricate mechanisms, we can anticipate a wealth of new insights into potential diagnostic markers and therapeutic strategies. Dive deeper into the Peptide Intel Hub's A–Z protocols to explore other emerging compounds, compare their unique properties, and remember to share this article to spark curiosity and conversation about the cutting edge of peptide research!

Sources

* Hormonal changes in PCOS. The Journal of endocrinology, 2024. https://pubmed.ncbi.nlm.nih.gov/38285626/ * Asprosin, a Fasting-Induced Glucogenic Protein Hormone. Cell, 2016. https://pubmed.ncbi.nlm.nih.gov/27087445/ * Asprosin-FABP5 Interaction Modulates Mitochondrial Fatty Acid Oxidation through PPARα Contributing to MASLD Development. Advanced science (Weinheim, Baden-Wurttemberg, Germany), 2025. https://pubmed.ncbi.nlm.nih.gov/40231957/ * OLFR734 Mediates Glucose Metabolism as a Receptor of Asprosin. Cell metabolism, 2019. https://pubmed.ncbi.nlm.nih.gov/31230984/ * The cerebellum modulates thirst. Nature neuroscience, 2024. https://pubmed.ncbi.nlm.nih.gov/38987435/ * Asprosin Aggravates Tubular Epithelial Cell Injury and Phenotypic Transformation via Mitochondrial Dynamics Disorder Mediated by Excessive Drp1 SUMOylation in Diabetic Nephropathy Mice. Advanced science (Weinheim, Baden-Wurttemberg, Germany), 2025. https://pubmed.ncbi.nlm.nih.gov/40859912/ * Asprosin as a regulator of hepatic lipogenesis and its association with hepatic steatosis. Journal of lipid research, 2025. https://pubmed.ncbi.nlm.nih.gov/41061856/ * Fibrillin-1 and asprosin, novel players in metabolic syndrome. Molecular genetics and metabolism, 2023. https://pubmed.ncbi.nlm.nih.gov/36630758/