Search

AimsThe incidence of hepatocellular carcinoma (HCC) in patients with Fontan-associated liver disease (i.e., FALD-HCC) has increased over time. However, the risk factors for HCC development remain unclear. Here, we compared the levels of non-invasive markers to the survival rate of FALD-HCC patients.MethodsFrom 2003 to 2021, 154 patients (66 men, 42.9%) developed liver disease after undergoing Fontan procedures. HCC was diagnosed in 15 (9.7%) (8 men, 53.3%) at a median age of 34 years (range, 21-45 years). We compared FALD-HCC and non-HCC cases; we generated marker level cutoffs using receiver operating characteristic curves. We sought to identify risk factors for HCC and mortality.ResultsThe incidence of HCC was 4.9% in FALD patients within 20 years after the Fontan procedure. Compared with non-HCC patients, FALD-HCC patients exhibited higher incidences of polysplenia and esophageal varices. At the time of HCC development, the hyaluronic acid (HA) level (p = 0.04) and the fibrosis-4 index (p = 0.02) were significantly higher in FALD-HCC patients than in non-HCC patients; the total bilirubin (T-BIL) level (p = 0.07) and the model for end-stage liver disease score [excluding the international normalized ratio (MELD-XI)] (p = 0.06) tended to be higher in FALD-HCC patients. Within approximately 20 years of the Fontan procedure, 10 patients died (survival rate, 96.9%). Kaplan-Meier curve analysis indicated that patients with T-BIL levels ≥ 2.2 mg/dL, HA levels ≥ 55.5 ng/mL, and MELD-XI scores ≥ 18.7 were at high risk of HCC, a generally poor prognosis, and both polysplenia and esophageal varices. Multivariate Cox regression analyses indicated that the complication of polysplenia [Hazard ratio (HR): 10.915] and a higher MELD-XI score (HR: 1.148, both p < 0.01) were independent risk factors for FALD-HCC.ConclusionsThe complication of polysplenia and a MELD-XI score may predict HCC development and mortality in FALD patients.

Although mutations in several genes have been reported in pulmonary arterial hypertension (PAH), most of PAH cases do not carry these mutations. This study aimed to identify a novel cause of PAH. To determine the disease-causing variants, direct sequencing and multiplex ligation-dependent probe amplification were performed to analyze 18 families with multiple affected family members with PAH. In one of the 18 families with PAH, no disease-causing variants were found in any of BMPR2, ACVRL1, ENG, SMAD1/4/8, BMPR1B, NOTCH3, CAV1, or KCNK3. In this family, a female proband and her paternal aunt developed PAH in their childhood. Whole-exome next-generation sequencing was performed in the 2 PAH patients and the proband's healthy mother, and a BRCA1-associated protein (BRAP) gene variant, p.Arg554Leu, was identified in the 2 family members with PAH, but not in the proband's mother without PAH. Functional analyses were performed using human pulmonary arterial smooth muscle cells (hPASMCs). Knockdown of BRAP via small interfering RNA in hPASMCs induced p53 signaling pathway activation and decreased cell proliferation. Overexpression of either wild-type BRAP or p.Arg554Leu-BRAP cDNA constructs caused cell death confounding these studies, however we observed higher levels of p53 signaling inactivation and hPASMC proliferation in cells expressing p.Arg554Leu-BRAP compared to wild-type BRAP. In addition, p.Arg554Leu-BRAP induced decreased apoptosis of hPASMCs compared with wild-type BRAP. In conclusion, we have identified a novel variant of BRAP in a Japanese family with PAH and our results suggest it could have a gain-of-function. This study sheds light on new mechanism of PAH pathogenesis.

Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV) valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM) components, versican and hyaluronan (HA), and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH) stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC) aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.