KRAS Affects Adipogenic Differentiation by Regulating Autophagy and MAPK Activation in 3T3-L1 and C2C12 Cells

Abstract

Kirsten rat sarcoma 2 viral oncogene homolog (Kras) is a proto-oncogene that encodes the small GTPase transductor protein KRAS, which has previously been found to promote cytokine secretion, cell survival, and chemotaxis. However, its effects on preadipocyte differentiation and lipid accumulation are unclear. In this study, the effects of KRAS inhibition on proliferation, autophagy, and adipogenic differentiation as well as its potential mechanisms were analyzed in the 3T3-L1 and C2C12 cell lines. The results showed that KRAS was localized mainly in the nuclei of 3T3-L1 and C2C12 cells. Inhibition of KRAS altered mammalian target of rapamycin (Mtor), proliferating cell nuclear antigen (Pcna), Myc, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein beta (C/ebp-β), diacylglycerol O-acyltransferase 1 (Dgat1), and stearoyl-coenzyme A desaturase 1 (Scd1) expression, thereby reducing cell proliferation capacity while inducing autophagy, enhancing differentiation of 3T3-L1 and C2C12 cells into mature adipocytes, and increasing adipogenesis and the capacity to store lipids. Moreover, during differentiation, KRAS inhibition reduced the levels of extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK), p38, and phosphatidylinositol 3 kinase (PI3K) activation. These results show that KRAS has unique regulatory effects on cell proliferation, autophagy, adipogenic differentiation, and lipid accumulation.

Nf1 deficiency modulates the stromal environment in the pretumorigenic rat mammary gland

“…The RAS effector ERK has been shown to phosphorylate PPARγ at Ser112 and consequently suppress PPARγ transcriptional activity (Shao et al, 1998;Choi et al, 2015). Concurrently, inhibition of KRAS has also been shown to promote in vitro adipogenic differentiation in the 3T3-L1 and C2C12 preadipocyte cell lines (Yu et al, 2021). Alternatively, RAS can indirectly suppress PPARγ activity through TAZ, the main downstream effector protein of the Hippo pathway.…”

An integrated analysis of dysregulated SCD1 in human cancers and functional verification of miR-181a-5p/SCD1 axis in esophageal squamous cell carcinoma

“…al, reported that MYC and SREBP1 cooperate to regulate the expressions of fatty acid genes, such as SCD1 in a feed-forward transcriptional loop, contributing to lipogenesis for neoplastic growth [42] . Inhibition of KRAS decreases the expression of SCD1, thereby reducing cell growth and inducing autophagy in 3T3-L1 and C2C12 cells, indicating that KRAS expression leads to changes in lipid accumulation capacity [43] . Consistent with the results above, KRAS inhibition using S -trans,transfarnesylthiosalicylic acid (FTS) decreases the gene expression of SCD1 in a dose-dependent manner, indicating that KRAS suppression hampers the expressions of lipogenesis-associated genes [44] .…”

Colitis-Mediated Dysbiosis of the Intestinal Flora and Impaired Vitamin A Absorption Reduce Ovarian Function in Mice

“…After lysis, the mixture was centrifuged at 16,000× g for 10 min to collect the protein-containing supernatant. Briefly, western blot experiments were performed as described previously [34]. The antibodies used in the study are shown in Supplementary Table S3.…”