Effects of low-fat diet and aging on metabolic profiles of Creb3l4 knockout mice
NUTRITION & DIABETES
Authors: Kim, T-H; Park, J-M; Jo, S-H; Kim, M-Y; Nojima, H.; Ahn, Y-H
Abstract
BACKGROUND/OBJECTIVES: Increased adipose tissue mass closely associates with the development of insulin resistance and type 2 diabetes mellitus. Previously, we reported that CREB3L4 expressed in adipose tissue negatively regulates adipogenesis, and Creb3l4 knockout mice fed a high-fat diet for 16 weeks showed fat cell hyperplasia, with improved glucose tolerance and insulin sensitivity. These mice did not show significant weight gain and fat mass. Because fat diet or aging is known to be associated with the development of obesity, we examined the effects of Creb3l4 gene subjected to low-fat diet (LFD) or aging process on body composition and obesity risk. SUBJECTS/METHODS: We fed Creb3l4 knockout mice a low-fat diet for 16 weeks (LFD group) or chow diet for over 1 year (aged group) and observed various metabolic parameters in the LFD-fed and aged Creb3l4 knockout mice. RESULTS: LFD-fed and aged Creb3l4 knockout mice showed significant weight gain and adiposity, impaired glucose tolerance and decreased insulin sensitivity, compared with wild-type mice. CONCLUSIONS: Creb3l4 has a critical role in metabolic phenotypes and a better understanding of its function may provide improved insight into the etiology of diabetes and other metabolic disorders.
The Novel Transcription Factor CREB3L4 Contributes to the Progression of Human Breast Carcinoma
JOURNAL OF MAMMARY GLAND BIOLOGY AND NEOPLASIA
Authors: Pu, Qian; Lu, Li; Dong, Ke; Geng, Wen-wen; Lv, Yan-rong; Gao, Hai-dong
Abstract
Breast carcinoma(BC)is the most common cancer type among females globally. Understanding the molecular pathways that trigger the development of BC is crucial for both prevention and treatment. As such, the role of transcription factors (TFs) in the development of BC is a focal point in this field. CREB3s play a critical role in initiating the unfolded protein response (UPR); however, the role of CREB3 family members in breast cancer development remains largely unknown. Here, we mined the ONCOMINE database for the transcriptional data of CREB3s in patients with BC. Then, the regulatory functions of a novel TF, CREB3L4, were investigated. CREB3L4 knockdown in MDA-MB-231 and MCF-7 cells suppressed proliferation and promoted apoptosis and cell cycle arrest. ChIP assays confirmed that CREB3L4 can directly bind to the PCNA promoter region, suggesting that the PCNA protein may be functionally downstream of CREB3L4. Additionally, the expression level of CREB3L4 was assessed using our cohort. CREB3L4 is upregulated in breast cancer tissues and is significantly associated with histological grade and tumour size (P = 0.001 and P < 0.001, respectively). Furthermore, PCNA expression was upregulated in breast cancer tissues and positively correlated with CREB3L4. In summary, CREB3L4 may play an important role in the progression of human BC and may serve as a therapeutic target.