Da Som Lee1,2 iD Tae Hyeon An2,3 iD Hyunmi Kim2,3 iD Eunsun Jung4 iD Gyeonghun Kim5 iD Seung Yeon Oh6 iD Jun Seok Kim7 iD Hye Jin Chun8 iD Jaeeun Jung9 iD Eun-Woo Lee2,3 iD Baek-Soo Han3,10 iD Dai Hoon Han11 iD Yong-Ho Lee8,12 iD Tae-Su Han3,4 iD Keun Hur13 iD Chul-Ho Lee3,14 iD Dae-Soo Kim9 iD Won Kon Kim2,3 iD Jun Won Park15 iD Seung-Hoi Koo7 iD Je Kyung Seong5,6 iD Sang Chul Lee2,3 iD Hail Kim1 iD Kwang-Hee Bae2,3 iD Kyoung-Jin Oh2,3

Da Som Lee, Tae Hyeon An and Hyunmi Kim contributed equally to this study.

Received: 7 September 2022 /Accepted: 28 November 2022 / Published online: 10 February 2023

© The Author(s) 2023

Abstract

Aims/hypothesis Non-alcoholic fatty liver disease (NAFLD) associated with type 2 diabetes may more easily progress towards severe forms of non-alcoholic steatohepatitis (NASH) and cirrhosis. Although the Wnt effector transcription factor 7-like 2 (TCF7L2) is closely associated with type 2 diabetes risk, the role of TCF7L2 in NAFLD development remains unclear. Here, we investigated how changes in TCF7L2 expression in the liver affects hepatic lipid metabolism based on the major risk factors of NAFLD development.

Methods Tcf7l2 was selectively ablated in the liver of C57BL/6N mice by inducing the albumin (Alb) promoter to recombine Tcf7l2 alleles floxed at exon 5 (liver-specific Tcf7l2-knockout [KO] mice: Alb-Cre;Tcf7l2f/f). Alb-Cre;Tcf7l2f/f and their wildtype (Tcf7l2f/f) littermates were fed a high-fat diet (HFD) or a high-carbohydrate diet (HCD) for 22 weeks to reproduce NAFLD/ NASH. Mice were refed a standard chow diet or an HCD to stimulate de novo lipogenesis (DNL) or fed an HFD to provide exogenous fatty acids. We analysed glucose and insulin sensitivity, metabolic respiration, mRNA expression profiles, hepatic triglyceride (TG), hepatic DNL, selected hepatic metabolites, selected plasma metabolites and liver histology.

Results Alb-Cre;Tcf7l2f/f essentially exhibited increased lipogenic genes, but there were no changes in hepatic lipid content in mice fed a normal chow diet. However, following 22 weeks of diet-induced NAFLD/NASH conditions, liver steatosis was exacerbated owing to preferential metabolism of carbohydrate over fat. Indeed, hepatic Tcf7l2 deficiency enhanced liver lipid content in a manner that was dependent on the duration and amount of exposure to carbohydrates, owing to cell-autonomous increases in hepatic DNL. Mechanistically, TCF7L2 regulated the transcriptional activity of Mlxipl (also known as ChREBP) by modulating O-GlcNAcylation and protein content of carbohydrate response element binding protein (ChREBP), and targeted Srebf1 (also called SREBP1) via miRNA (miR)-33-5p in hepatocytes. Eventually, restoring TCF7L2 expression at the physiological level in the liver of Alb-Cre;Tcf7l2f/f mice alleviated liver steatosis without altering body composition under both acute and chronic HCD conditions.

Conclusions/interpretation In mice, loss of hepatic Tcf7l2 contributes to liver steatosis by inducing preferential metabolism of carbohydrates via DNL activation. Therefore, TCF7L2 could be a promising regulator of the NAFLD associated with highcarbohydrate diets and diabetes since TCF7L2 deficiency may lead to development of NAFLD by promoting utilisation of excess glucose pools through activating DNL.

Data availability RNA-sequencing data have been deposited into the NCBI GEO under the accession number GSE162449 (www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE162449).

Kyoung-Jin Oh 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

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Keywords Carbohydrate . De novo lipogenesis . Fatty acid . Glucose . Insulin . Lipogenesis . NAFLD . TCF7L2 . TG accumulation . Type 2 diabetes

Extended author information available on the last page of the article

彭 露1 ,廖若夷2 ,唐 燕3 ,高子琪1 ,佀惠婕1 ,刘 彬2 ,郭 元2

(1. 湖南中医药大学,湖南 长沙,410208; 2. 湖南中医药大学第一附属医院,湖南 长沙,410007; 3. 湖南中医药大学第二附属医院,湖南 长沙,410005)

[摘要]目的:探讨象皮生肌膏对压疮模型大鼠创面愈合的影响及其作用机制。方法:将72只大鼠随机分为空白组、模型组、湿润烧伤膏组、象皮生肌膏组,每组各18只。空白组不予造模,其余3组建立川期、IV期压疮模型。造模成功后空白组与模型组给予0. 9%氯化钠注射液冲洗，湿润烧伤膏组给予湿润烧伤膏外用,象皮生肌膏组给予象皮生肌膏外用。干预14d。于干预第3、7、14天观察创面愈合率,组织病理情况，白细胞介素-6(IL-6)、肿瘤坏死因子-ax(TNF-a)、血管内皮生长因子( VEGF)水平,p38丝裂原激活的蛋白.激酶( p38MAPK)、MAPK激活蛋白激酶2(MK2)蛋白表达情况。结果:与模型组比较,湿润烧伤膏组、象皮生肌膏组治疗第3、7、14天创面愈合率均升高(P<0.05)。组织病理结果显示,治疗第14天,模型组可见少量毛细血管,湿润烧伤膏组、象皮生肌膏组可见大量成纤维细胞,毛细血管丰富。湿润烧伤膏组、象皮生肌膏组治疗第3、7、14天IL-6、TNF -x、VEGFp38MAPK蛋白、MK2蛋白含量与模型组比较,差异均有统计学意义(P<0.05)。象皮生肌膏组治疗第7、14天IL-6含量及第7天TNF-x、VEGF含量与湿润烧伤膏组比较,差异均有统计学意义(P<0.05)。结论:象皮生肌膏能促进压疮创面修复,其作用机制可能与抑制p38MAPK MK2蛋白表达,减少IL-6、TNF-a释放、调控VEGF合成有关。

[关键词]压疮 ;象皮生肌膏;大鼠;L-6;TNF-a; VEGF ;p38MAPK;MK2
[中图分类号]R285.5
[文献标识码]A
DOI: 10.16808/j. cnki. issn 1003-7705.2023.02.040

Effect of Xiangpi Shengji ointment on wound healing in a rat model of pressure ulcers and its mechanism of action PENG Lu',LIAO Ruoyi2 ,TANG Yan’, GAO Ziqi',SI Huijie' ,LIU Bin2 ,GUO Yuan

( 1. Hunan University of Chinese Medicine , Changsha 410208 , Hunan, China;2. The First Affiliated Hospital of Hunan University of Chinese Medicine，Changsha 4 10007 , Hunan , China; 3. The Second Affiliated Hospital of Hunan University of Chinese Medicine , Changsha 4 10005, Hunan，China)
[ Abstract] Objective :To investigate the effect of Xiangpi Shengji ointment on wound healing in a rat model of pressure ulcers and its mechanism of action. Methods:A total of 72 rats were randomly divided into blank group， model group , Shirun Shaoshang ointment group，and Xiangpi Shengji ointment group , with 18 rats in each group. The rats in the blank group were not used for modeling , and those in the other groups were used to establish a model of stage IHI/IV pressure ulcers. After successful modeling, the rats in the blank group and the model group were given irrigation with 0. 9% sodium chloride injection, those in the Shirun Shaoshang ointment group were given the external application of Shirun Shaoshang ointment , and those in the Xiangpi Shengji ointment group were given the external application of Xiangpi Shengji ointment. Intervention was given for 14 days. Related indicators were observed on days 3,7,and 14 of intervention , including wound healing rate , histopathology，the levels of interleukin-6 (IL-6) ， tumor necrosis factor-a ( TNF-a) , and vascular endothelial growth factor ( VEGF)，and the protein expression levels of p38 mitogen -activated protein kinase ( p38MAPK) and MAPK-activated protein kinase 2 ( MK2). Results : Compared with the model group , the Shirun Shaoshang ointment group and Xiangpi Shengji ointment group had a significant increase in wound healing rate on days 3, 7,and 14 of treatment ( P<0. 05 ). Histopathology results showed that on day 14 of treatment , the model group had a small number of capillaries , while the Shirun Shaoshang ointment group and Xiangpi Shengji ointment group had a large number of fibroblasts and abundant capillaries. On days 3,7, and 14 of treatment , there were significant differences in the content of IL-6,TNF-a, VEGF , p38MAPK protein , and MK2 protein between the Shirun Shaoshang ointment/ Xiangpi Shengji ointment group and the model group ( P<0.05). There were significant differences between the Xiangpi Shengji ointment group and the Shirun Shaoshang ointment group in the content of IL-6 on days 7 and 14 and the content of TNF-a and VEGF on day 7 ( P<0. 05 ). Conclusion :Xiangpi Shengji ointment can promote wound repair of pressure ulcers, possibly by inhibiting the protein expression of p38MAPK and MK2 , reducing the release of IL-6 and TNF -x, and regulating the synthesis of VEGF.

[ Keywords ] pressure ulcers ; Xiangpi Shengji ointment ; rat ; interleukin -6 ; tumor necrosis factor- a ; vascular endothelial growth factor ;p38 mitogen- activated protein kinase ;MAPK- activated protein kinase 2