Development of Capsular Fibrosis Beneath the Liver Surface in Humans and Mice
HEPATOLOGY
Authors: Balog, Steven; Li, Yuchang; Ogawa, Tomohiro; Miki, Toshio; Saito, Takeshi; French, Samuel W.; Asahina, Kinji
Abstract
Glisson's capsule is the connective tissue present in the portal triad as well as beneath the liver surface. Little is known about how Glisson's capsule changes its structure in capsular fibrosis (CF), which is characterized by fibrogenesis beneath the liver surface. In this study, we found that the human liver surface exhibits multilayered capsular fibroblasts and that the bile duct is present beneath the mesothelium, whereas capsular fibroblasts are scarce and no bile ducts are present beneath the mouse liver surface. Patients with cirrhosis caused by alcohol abuse or hepatitis C virus infection show development of massive CF. To examine the effect of alcohol on CF in mice, we first injected chlorhexidine gluconate (CG) intraperitoneally and then fed alcohol for 1 month. The CG injection induces CF consisting of myofibroblasts beneath the mesothelium. One month after CG injection, the fibrotic area returns to the normal structure. In contrast, additional alcohol feeding sustains the presence of myofibroblasts in CF. Cell lineage tracing revealed that mesothelial cells give rise to myofibroblasts in CF, but these myofibroblasts disappear 1 month after recovery with or without alcohol feeding. Capsular fibroblasts isolated from the mouse liver spontaneously differentiated into myofibroblasts and their differentiation was induced by transforming growth factor beta 1 (TGF-beta 1) or acetaldehyde in culture. In alcohol-fed mice, infiltrating CD11b(+)Ly-6C(Low/-) monocytes had reduced mRNA expression of matrix metalloproteinase 13 and matrix metalloproteinase 9 and increased expression of tissue inhibitor of matrix metalloproteinase 1, Tgfb1, and interleukin-10 during resolution of CF. Conclusion: The present study revealed that the structure of Glisson's capsule is different between human and mouse livers and that alcohol impairs the resolution of CF by changing the phenotype of Ly-6C(Low/-) monocytes.
Betaglycan (TGFBR3) up-regulation correlates with increased TGF-beta signaling in Marfan patient fibroblasts in vitro
CARDIOVASCULAR PATHOLOGY
Authors: Groeneveld, Menno Evert; Bogunovic, Natalija; Musters, Rene John Philip; Tangelder, Geert Jan; Pals, Gerard; Wisselink, Willem; Micha, Dimitra; Yeung, Kak Khee
Abstract
Background: Marian syndrome (MIS), a congenital connective tissue disorder leading to aortic aneurysm development, is caused by fibrillin-1 (FBN1) gene mutations. Transforming growth factor beta (TGF-beta) might play a role in the pathogenesis. It is still a matter of discussion if and how TGF-beta, up-regulates the intracellular downstream pathway, although TGF-beta receptor 3 (TGFBR3 or Betaglycan) is thought to be involved. We aimed to elucidate the role of TGFBR3 protein in TGF-beta signaling in Marfan patients. Methods: Dermal fibroblasts of MIS patients with haploinsufficient (HI; n=9) or dominant negative (DN; n=4) FBN1 gene mutations, leading to insufficient or malfunctioning fibrillin-1, respectively, were used. Control cells (n = 10) were from healthy volunteers. We quantified TGFBR3 protein expression by immunofluorescence microscopy and gene expression of FBN1, TGFB1, its receptors, and downstream transcriptional target genes by quantitative polymerase chain reaction. Results: Betaglycan protein expression in FBN1 mutants pooled was higher than in controls (P=.004) and in DN higher than in HI (P=.015). In DN, significantly higher mRNA expression of FBN1 (P=.014), SMAD7 (P=.019), FISP47 (P=.023), and SERPINE1 (P=.008), but a lower FISPA5 expression (P=.029), was observed than in HI. A pattern of higher expression was noted for TGFB1 (P=.059), FN1 (P=.089), and COL1A1 (P=.089) in DN as compared to HI. TGFBR3 protein expression in cells, both presence in the encloplasmic reticulum and amount of yes ides per cell, correlated positively with TGEB1 mRNA expression (Rs=0.60, P=.017; Rs=0.55, P=.029; respectively). TGFBR3 gene expression did not differ between groups. Conclusion: We demonstrated that activation of TGF-beta signaling is higher in patients with a DN than an HI FBN1 gene mutation. Also, TGFBR3 protein expression is increased in the DN group and correlates positively with TGFB1 expression in groups pooled. We suggest that TGFBR3 protein expression is involved in up-regulated TGF-beta signaling in MFS patients with a DN FBN1 gene mutation. (C) 2017 Elsevier Inc. All rights reserved.