CRTC3 Regulates the Lipid Metabolism and Adipogenic Differentiation of Porcine Intramuscular and Subcutaneous Adipocytes by Activating the Calcium Pathway

Abstract

Fat deposition, especially the intramuscular (IM) fat deposition, is directly associated with meat quality. The cyclic adenosine monophosphate (cAMP)-responsive element binding-protein (CREB)-regulated transcription coactivator 3 (CRTC3) plays an important role in energy metabolism and various biological processes. The expression of porcine CRTC3 in skeletal muscle is positively associated with intramuscular fat deposition and possesses the capacity to control the intramuscular (IM) adipocyte morphology. However, the metabolic effects and transcriptional mechanism of CRTC3 in porcine intramuscular (IM) adipocytes as well as the regulatory mechanism of CRTC3 on porcine adipocyte differentiation have not been studied. Here, we utilized metabolomics and RNA sequencing (RNA-seq) to determine the metabolic and transcriptome profiles of CRTC3-overexpressing IM adipocytes. Moreover, the effect and regulation mechanism of CRTC3 on porcine IM and subcutaneous (SC) adipocyte differentiation were also studied. Our results showed that CRTC3 overexpression dramatically altered the metabolites in IM adipocytes. Glycerophospholipid (GP) metabolism and related genes were significantly changed in CRTC3-overexpressing IM adipocytes. Moreover, we demonstrated that CRTC3 overexpression promotes adipogenic differentiation by upregulating the Ca 2+ -cAMP signaling pathway in IM and SC adipocytes. We showed alterations in metabolites and in the expression of genes involved in lipid metabolism in CRTC3-overexpressing adipocytes and demonstrated the regulatory mechanism of CRTC3 on the adipogenic differentiation of porcine adipocytes. These results provide new insights into the regulatory roles of CRTC3 in porcine adipocytes, which could be an important target to regulate fat deposition in animals.

Integrative Analysis Between Genome-Wide Association Study and Expression Quantitative Trait Loci Reveals Bovine Muscle Gene Expression Regulatory Polymorphisms Associated With Intramuscular Fat and Backfat Thickness

“…Conversely, the CRTC3 and the IQGAP1 were regulated in cis by this eQTL. The first one, CRTC3 is part of the cAMP responsive element-binding protein (CREB)-regulated transcription coactivator (CRTC) family and plays an important role in lipid and glucose metabolism ( Liu et al, 2020 ; Liu et al, 2021 ). Studying IMF deposition, Liu et al (2020) overexpressed CRTC3 in porcine IMF adipocytes and observed a faster accumulation of lipid droplets in cells together with an upregulation of important fat metabolism genes, such as perilipin, PPARγ, C/EBPα, leptin, and FABP4 (Fatty acid-binding protein 4).…”

“…Studying IMF deposition, Liu et al (2020) overexpressed CRTC3 in porcine IMF adipocytes and observed a faster accumulation of lipid droplets in cells together with an upregulation of important fat metabolism genes, such as perilipin, PPARγ, C/EBPα, leptin, and FABP4 (Fatty acid-binding protein 4). In a more recent work, Liu et al (2021) , demonstrated that the overexpression of CRTC3 changes the metabolic profile in intramuscular adipocytes, and also promotes adipogenic differentiation of intramuscular and subcutaneous adipocytes through the calcium signaling pathway. We also highlight that in the same genomic region (BTA21, 22 Mb), we found two other eQTL (rs379449619 and rs525656948) located on the CRTC3 gene associated with IMF in our population, emphasizing its relevance for IMF molecular regulation.…”

CircSETBP1 Acts as a MiR-149-5p Sponge to Promote Intramuscular Fat Deposition by Regulating CRTCs

“…Ryota and Liu found that calcium promotes fat accumulation. 52,53 In summary, the results of this study reveal the regulatory mechanism of circSETBP1/miR-149-5p/CRTCs axis in lipid metabolism of porcine IMF and also provide an important reference for analyzing the molecular mechanism of ceRNA in pork quality.…”

“…Phosphorylated CREB will go in to the nucleus and bind to the cAMP response element, synergistically mediating cell function with calcium signaling. − Ca 2+ is a versatile signaling molecule that regulates many biological processes, including cell differentiation, proliferation, and death. Ryota and Liu found that calcium promotes fat accumulation. , …”

Current State of Metabolomics Research in Meat Quality Analysis and Authentication

“…Metabolomics can be used as a complementary tool of proteomics and transcriptomics to address this issue. Liu et al performed a combined metabolomics and transcriptomics approach to explore the effect and regulation mechanism of CRTC3 on porcine intramuscular adipocyte differentiation [119]. This study revealed that CRTC3 regulates glycerophospholipid metabolism-related genes and promotes increased phospholipid formation to enlarge adipocytes for more lipid storage.…”