Cover Story Current Issue

The small intestine, as the primary site of nutrient absorption, integrates signals from dietary components and gut microbiota to coordinate systemic energy balance, metabolism, and glucose homeostasis alongside other tissues such as the pancreas, liver, and brain. Nuclear receptors represent one mechanism by which the intestinal epithelium senses and respond to dietary signals via transcriptional regulation of metabolic programs. The Peroxisome Proliferator Activated Receptors (PPARs), including PPARα, PPARδ, and PPARγ, are lipid-responsive nuclear hormone receptors. PPAR transcriptional activity is highly context-dependent, shaped by the availability and affinity of their lipid ligands and co-regulators as well as by cell and tissue types. Whereas PPARγ and PPARδ are established regulators of glucose homeostasis, acting in white adipose tissue, skeletal muscle, and liver to improve insulin sensitivity, PPARα has been primarily associated with hepatic lipid metabolism, where it promotes fatty acid transport, β-oxidation, and ketogenesis. Due to their roles in lipid metabolism and anti-inflammatory processes, selective PPAR agonists are being actively pursued as therapies in clinical and pre-clinical studies for metabolic diseases. Thus, it is critical to improve our understanding of the context-specific and tissue-specific effects of PPAR signaling.

Full text

 

Current Issue

Adult-onset deficiency of β-klotho in the liver reveals a novel role in lipid homeostasis

Alexandra S. Aaldijk, Cristy R.C. Verzijl, Milaine V. Hovingh, Nicolette C.A. Huijkman, ... Johan W. Jonker

Background

β-klotho (KLB), the obligate co-receptor for fibroblast growth factor (FGF) 19 and 21 signalling, has emerged as a therapeutic target for metabolic disease. Current understanding of KLB function is based largely on germline knockout mouse models, where developmental abnormalities obscure its function in adult physiology. Here, we used somatic hepatocyte-specific gene editing in adult mice to define hepatic KLB function.

Methods

Hepatocyte-specific KLB deficiency was induced by retro-orbital delivery of adeno-associated virus particles containing guide RNAs targeting Klb in adult male mice expressing Cas9 in the liver. Following transduction, mice were maintained on a 4-week chow diet or a 12-week high-fat diet, prior to comprehensive metabolic and biochemical phenotyping.

Results

Adult-onset hepatic KLB deficiency did not alter body weight or composition, indicating that reduced bodyweight in germline models reflects developmental effects. In line with previous studies, KLB deficiency resulted in derepressed bile acid synthesis, elevated faecal bile acid excretion, and a shift towards a more hydrophobic bile acid pool. Importantly, we also uncovered a role for hepatic KLB in regulating lipid homeostasis. Chow-fed KLB-deficient mice exhibited reduced circulating very-low-density lipoprotein levels (VLDL) with marked hepatic triglyceride accumulation, suggesting altered VLDL metabolism as a potential mechanism driving steatosis.

Conclusions

Using an adult-onset liver-specific knockout model, we disentangled KLB function from developmental confounders and established KLB as a critical regulator of adult lipid and lipoprotein homeostasis. Our study redefines the physiological role of KLB in hepatic metabolism and has important implications for the interpretation of FGF19/KLB-directed therapies for metabolic diseases.

Articles in Press

Adult-onset deficiency of β-klotho in the liver reveals a novel role in lipid homeostasis

Alexandra S. Aaldijk, Cristy R.C. Verzijl, Milaine V. Hovingh, Nicolette C.A. Huijkman, ... Johan W. Jonker

Background

β-klotho (KLB), the obligate co-receptor for fibroblast growth factor (FGF) 19 and 21 signalling, has emerged as a therapeutic target for metabolic disease. Current understanding of KLB function is based largely on germline knockout mouse models, where developmental abnormalities obscure its function in adult physiology. Here, we used somatic hepatocyte-specific gene editing in adult mice to define hepatic KLB function.

Methods

Hepatocyte-specific KLB deficiency was induced by retro-orbital delivery of adeno-associated virus particles containing guide RNAs targeting Klb in adult male mice expressing Cas9 in the liver. Following transduction, mice were maintained on a 4-week chow diet or a 12-week high-fat diet, prior to comprehensive metabolic and biochemical phenotyping.

Results

Adult-onset hepatic KLB deficiency did not alter body weight or composition, indicating that reduced bodyweight in germline models reflects developmental effects. In line with previous studies, KLB deficiency resulted in derepressed bile acid synthesis, elevated faecal bile acid excretion, and a shift towards a more hydrophobic bile acid pool. Importantly, we also uncovered a role for hepatic KLB in regulating lipid homeostasis. Chow-fed KLB-deficient mice exhibited reduced circulating very-low-density lipoprotein levels (VLDL) with marked hepatic triglyceride accumulation, suggesting altered VLDL metabolism as a potential mechanism driving steatosis.

Conclusions

Using an adult-onset liver-specific knockout model, we disentangled KLB function from developmental confounders and established KLB as a critical regulator of adult lipid and lipoprotein homeostasis. Our study redefines the physiological role of KLB in hepatic metabolism and has important implications for the interpretation of FGF19/KLB-directed therapies for metabolic diseases.

2025 Impact Factor: 6.3

You are what you eat

Here is a video of Vimeo. When the iframes is activated, a connection to Vimeo is established and, if necessary, cookies from Vimeo are also used. For further information on cookies policy click here.

Auf Werbeinhalte, die vor, während oder nach Videos von WEBSITE-URL eingeblendet werden, hat WEBSITE-URL keinen Einfluss. Wir übernehmen keine Gewähr für diese Inhalte. Weitere Informationen finden Sie hier.