Inhibition of EGFR attenuates fibrosis and stellate cell activation in diet-induced model of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD begins with steatosis and advances to nonalcoholic steatohepatitis (NASH) and cirrhosis. The molecular mechanisms involved in NAFLD progression are not understood. Based on recent studies showing dysregulation of epidermal growth factor receptor (EGFR) in animal models of liver injury, we sought to determine if inhibition of EGFR mitigates liver fibrosis and HSC activation in NAFLD. We utilized the high fat diet (HFD)-induced murine model of liver injury to study the role of EGFR in NAFLD. The lipid accumulation, oxidative stress, hepatic stellate cell (HSC) activation and matrix deposition were examined in the liver tissues. We also evaluated the EGFR signaling pathway, ROS activation and pro-fibrogenic phenotype in oxidized low density lipoproteins (ox-LDL) challenged cultured HSCs. We demonstrate that EGFR was phosphorylated in liver tissues of HFD murine model of NAFLD. Inhibition of EGFR prevented diet-induced lipid accumulation, oxidative stress, and HSC activation and matrix deposition. In cultured HSCs, we show that ox-LDL caused rapid activation of the EGFR signaling pathway and induce the production of reactive oxygen species. EGFR also mediated HSC activation and promoted a pro-fibrogenic phenotype. In conclusion, our data demonstrate that EGFR plays an important role in NAFLD and is an attractive target for NAFLD therapy.     

老年慢性心力衰竭患者血清sST2、CTGF、suPAR与心功能的关系及其联合检测对心血管事件的预测价值

摘要 目的：探讨老年慢性心力衰竭（CHF）患者血清可溶性肿瘤生成抑制因子2（sST2）、可溶性尿激酶纤溶酶原激活物受体（suPAR）、结缔组织生长因子（CTGF）与心功能的关系及其联合检测对心血管事件（CVE）的预测价值。方法：选取2019年1月～2022年1月我院收治的150例老年CHF患者（CHF组）,其中纽约心脏病协会（NYHA）分级Ⅱ级49例、Ⅲ级72例、Ⅳ级29例,根据随访6个月是否发生CVE分为CVE组（n=34）和非CVE组（n=116）,另选取同期在我院进行体检的110例健康体检志愿者作为对照组。通过超声心动图检查左室收缩末期内径（LVESD）、左室射血分数（LVEF）、左心室舒张末期内径（LVEDD）,酶联免疫吸附试验法检测血清sST2、CTGF、suPAR水平。多因素Logistic回归分析老年CHF患者发生CVE的影响因素,Pearson或Spearman相关性分析老年CHF患者血清sST2、CTGF、suPAR水平与超声心功能指标和NYHA分级的相关性,受试者工作特征（ROC）曲线分析血清sST2、CTGF、suPAR对老年CHF患者发生CVE的预测价值。结果：CHF组血清sST2、CTGF、suPAR水平和LVESD、LVEDD高于对照组,LVEF低于对照组（P＜0.05）。NYHA分级Ⅱ级、Ⅲ级、Ⅳ级老年CHF患者血清sST2、CTGF、suPAR水平均依次升高（P＜0.05）。 老年CHF患者血清sST2、CTGF、suPAR水平与LVEF呈负相关,与LVESD、LVEDD、NYHA分级呈正相关（P均＜0.05）。NYHA分级≥Ⅲ级（OR=2.318）、N末端B型钠尿肽前体（NT-proBNP）升高（OR=1.104）、sST2升高（OR=1.641）、CTGF升高（OR=1.644）、suPAR升高（OR=1.892）为老年CHF患者CVE发生的独立危险因素,LVEF升高（OR=0.839）为其独立保护因素,差异均有统计学意义（P＜0.05）。血清sST2、CTGF、suPAR单独与联合预测老年CHF患者发生CVE的曲线下面积分别为0.788、0.782、0.771、0.936。结论：老年CHF患者血清sST2、CTGF、suPAR水平升高与心功能异常和CVE发生密切相关,联合检测血清sST2、CTGF、suPAR水平对老年CHF患者发生CVE的预测价值较高。     

Pericytes display increased CCN2 expression upon culturing

By providing a source of α-smooth muscle actin (α-SMA)-expressing myofibroblasts, microvascular pericytes contribute to the matrix remodeling that occurs during tissue repair. However, the extent to which pericytes may contribute to the fibroblast phenotype post-repair is unknown. In this report, we test whether pericytes isolated from human placenta can in principle become fibroblast-like. Pericytes were cultured in vitro for 11 passages. The Affymetrix mRNA expression profile of passage 2 and passage 11 pericytes was compared. The expression of type I collagen, thrombospondin and fibronectin mRNAs was induced by passaging pericytes in culture. This induction of a fibroblast phenotype was paralleled by induction of connective tissue growth factor (CTGF/CCN2) and type I collagen protein expression and the fibroblast marker ASO2. These results indicate that, in principle, pericytes have the capacity to become fibroblast-like and that pericytes may contribute to the population of fibroblasts in a healed wound.     

The contribution of adhesion signaling to lactogenesis

The mammary gland undergoes hormonally controlled cycles of pubertal maturation, pregnancy, lactation, and involution, and these processes rely on complex signaling mechanisms, many of which are controlled by cell–cell and cell–matrix adhesion. The adhesion of epithelial cells to the extracellular matrix initiates signaling mechanisms that have an impact on cell proliferation, survival, and differentiation throughout lactation. The control of integrin expression on the mammary epithelial cells, the composition of the extracellular matrix and the presence of secreted matricellular proteins all contribute to essential adhesion signaling during lactogenesis. In vitro and in vivo studies, including the results from genetically engineered mice, have shed light on the regulation of these processes at the cell and tissue level and have led to increased understanding of the essential signaling components that are regulated in temporal and cell specific manner during lactogenesis. Recent studies suggest that a secreted matricellular protein, CTGF/CCN2, may play a role in lactogenic differentiation through binding to β1 integrin complexes, enhancing the production of extracellular matrix components and contributions to cell adhesion signaling.     

Thrombopoietic-mesenchymal interaction that may facilitate both endochondral ossification and platelet maturation via CCN2

CCN2 plays a central role in the development and growth of mesenchymal tissue and promotes the regeneration of bone and cartilage in vivo. Of note, abundant CCN2 is contained in platelets, which is thought to play an important role in the tissue regeneration process. In this study, we initially pursued the possible origin of the CCN2 in platelets. First, we examined if the CCN2 in platelets was produced by megakaryocyte progenitors during differentiation. Unexpectedly, neither megakaryocytic CMK cells nor megakaryocytes that had differentiated from human haemopoietic stem cells in culture showed any detectable CCN2 gene expression or protein production. Together with the fact that no appreciable CCN2 was detected in megakaryocytes in vivo, these results suggest that megakaryocytes themselves do not produce CCN2. Next, we suspected that mesenchymal cells situated around megakaryocytes in the bone marrow were stimulated by the latter to produce CCN2, which was then taken up by platelets. To evaluate this hypothesis, we cultured human chondrocytic HCS-2/8 cells with medium conditioned by differentiating megakaryocyte cultures, and then monitored the production of CCN2 by the cells. As suspected, CCN2 production by HCS-2/8 was significantly enhanced by the conditioned medium. We further confirmed that human platelets were able to absorb/uptake exogenous CCN2 in vitro. These findings indicate that megakaryocytes secrete some unknown soluble factor(s) during differentiation, which factor stimulates the mesenchymal cells to produce CCN2 for uptake by the platelets. We also consider that, during bone growth, such thrombopoietic-mesenchymal interaction may contribute to the hypertrophic chondrocyte-specific accumulation of CCN2 that conducts endochondral ossification.     

CCN5 expression in mammals

The six proteins of the CCN family have important roles in development, angiogenesis, cell motility, proliferation, and other fundamental cell processes. To date, CCN5 distribution in developing rodents and humans has not been mapped comprehensively. CCN5 strongly inhibits adult smooth muscle cell proliferation and motility. Its anti-proliferative action predicts that CCN5 would not be present in developing tissues until the proliferation phase of tissue morphogenesis is complete. However, estrogen induces CCN5 expression in epithelial and smooth muscle cells, suggesting that CCN5 might be widely expressed in embryonic tissues exposed to high levels of estrogen. 9–16 day murine embryos and fetuses and 3–7 month human fetal tissues were analyzed by immunohistochemistry. CCN5 was detected in nearly all developing tissues. CCN5 protein expression was initially present in most tissues, and at later times in development tissue-specific expression differences were observed. CCN5 expression was particularly strong in vascular tissues, cardiac muscle, bronchioles, myotendinous junctions, and intestinal smooth muscle and epithelium. CCN5 expression was initially absent in bone cartilaginous forms but was increasingly expressed during bone endochondral ossification. Widespread CCN5 mRNA expression was detected in GD14.5 mice. Although CCN2 and CCN5 protein expression patterns in some adult pathologic conditions are inversely expressed, this expression pattern was not found in developing mouse and human tissues. The widespread expression pattern of CCN5 in most embryonic and fetal tissues suggests a diverse range of functions for CCN5. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

卵巢癌中结缔组织生长因子的表达及其临床病理意义

目的:探讨卵巢癌中结缔组织生长因子(CTGF)的表达及其与卵巢癌临床病理特征的关系。方法:采用免疫组化法检测116例卵巢癌和25例正常卵巢组织中CTGF表达,并分析其与卵巢癌临床病理参数的关系。结果:正常卵巢组织及卵巢癌中CTGF的阳性表达率分别96%(24/25)、65%(75/116),卵巢癌中CTGF的阳性表达率显著低于正常卵巢组织(P0.05)。CTGF的表达降低与卵巢癌患者的淋巴结转移、腹膜内转移及对化疗的敏感性显著相关(P0.05);进一步的多因素Logistic回归分析显示CTGF的表达与卵巢癌腹膜转移(P=0.006,OR=4.185,95%CI=1.447-11.352)和淋巴结转移(P0.001,OR=6.336,95%CI=2.563-15.972)均显著相关。结论:卵巢癌中CTGF的表达缺失,是卵巢癌腹膜转移和淋巴结转移的独立影响因素,可能作为预测卵巢癌转移的参考指标。     

Yin and Yang: CCN3 inhibits the pro-fibrotic effects of CCN2

Fibrotic disease is a significant cause of mortality. CCN2 (connective tissue growth factor [CTGF]), a member of the CCN family of matricellular proteins, plays a significant role in driving the fibrogenic effects of cytokines such as transforming growth factor β (TGFβ). It has been proposed that other members of the CCN family can either promote or antagonize the action of CCN2, depending on the context. A recent elegant study published by Bruce Riser and colleagues (Am J Pathol. 174:1725–34, 2009) illustrates that CCN3 (nov) antagonizes the fibrogenic effects of CCN2. This paper, the subject of this commentary, raises the intriguing possibility that CCN3 may be used as a novel anti-fibrotic therapy.     

Connective tissue growth factor (CTGF,CCN2) gene regulation: a potent clinical bio-marker of fibroproliferative disease?

The CCN (cyr61, ctgf, nov) family of modular proteins regulate diverse biological affects including cell adhesion, matrix production, tissue remodelling, proliferation and differentiation. Recent targeted gene disruption studies have demonstrated the CCN family to be developmentally essential for chondrogenesis, osteogenesis and angiogenesis. CCN2 is induced by agents such as angiotensin II, endothelin-1, glucocorticoids, HGF, TGFβ, and VEGF, and by hypoxia and biomechanical and shear stress. Dysregulated expression of CCN2 has also been widely documented in many fibroproliferative diseases. This mini-review will focus on CCN2, and the recent progress in understanding CCN2 gene regulation in health and disease. That CCN2 should be considered a novel and informative surrogate clinical bio-marker for fibroproliferative disease is discussed.