Interspecies transcriptomic comparison identifies a potential porto-sinusoidal vascular disorder rat model suitable for in vivo drug testing.

BACKGROUND: Porto-sinusoidal vascular disorder (PSVD) involves a group of rare vascular liver diseases of unknown aetiology that may lead to the development of portal hypertension and its life-threatening complications. Its pathophysiology is not well understood, and animal models described to date do not fully recapitulate human disease. METHODS: We developed three different PSVD rat models by either immunosensitization (repetitive intraportal LPS or intramuscular spleen extract injections) or toxic (Selfox: combination of FOLFOX and a selenium-enriched diet) treatment and characterized them at haemodynamic, histological, biochemical and transcriptional levels. We compared these results to human data. RESULTS: All three models developed significant portal hypertension, while only the LPS and the Selfox models displayed PSVD-specific and nonspecific histological alterations in the absence of cirrhosis. Transcriptional comparison between rat models and human data showed that both LPS and Selfox models recapitulate the main transcriptional alterations observed in humans, especially regarding haemostasis, oxidative phosphorylation and cell cycle regulation. Reproducibility and feasibility was higher for the Selfox model. CONCLUSIONS: The Selfox rat model faithfully reproduces the main alterations described in PSVD. Its use as a preclinical model for drug testing in progressing PSVD can be a significant step forward towards the development of new therapeutic targets for this rare condition.

Lack of endothelial autophagy does not impair liver regeneration after partial hepatectomy in mice.

Liver sinusoidal endothelial cells (LSEC) are key elements in regulating the liver response to injury and regeneration. While endothelial autophagy is essential to protect endothelial cells from injury-induced oxidative stress and fibrosis, its role in liver regeneration has not been elucidated. This study was intended to investigate the role of endothelial autophagy in liver regeneration in the context of partial hepatectomy (PHx). Analysis of autophagy levels in rat LSEC after PHx indicated a tendency to decrease activity the first 2 days after surgery. PHx performed in mice with impaired endothelial autophagy (Atg7flox/flox ;VE-Cadherin-Cre+ ) and their littermate controls showed no differences neither in liver-to-body weight ratio, histological analysis, hepatocyte proliferation nor vascular integrity during the first 7 days after PH and liver regeneration was completely achieved. Our results indicate that endothelial autophagy does not play an essential role in the coordination of the liver regeneration process after PHx.

Short-term hemodynamic effects of ß-blockers influence survival of patients with decompensated cirrhosis.

BACKGROUND & AIMS: Whether the effect of ß-blockers on arterial pressure and/or cardiac function may offset the benefit of reducing portal pressure in advanced cirrhosis is controversial. Herein, we aimed to evaluate the systemic and splanchnic hemodynamic effects of ß-blockers in decompensated vs. compensated cirrhosis and to investigate the influence of systemic hemodynamic changes on survival times in decompensated cirrhosis. METHODS: Patients with cirrhosis and high-risk esophageal varices, without previous bleeding, were consecutively included and grouped according to the presence or absence of decompensation (ascites with or without overt encephalopathy). Systemic and hepatic hemodynamic measurements were performed before starting ß-blockers and again after 1 to 3 months of treatment (short-term). RESULTS: Four hundred and three patients were included (190 decompensated and 213 compensated). At baseline, decompensated patients had higher portal pressure than compensated patients and were more hyperdynamic, with higher cardiac output (CO) and lower arterial pressure. Under ß-blockers, decompensated patients had lower portal pressure decrease (10 ± 18% vs. 15 ± 12%; p <0.05) and had greater reductions in heart rate (p <0.001) and CO (17 ± 15% vs. 10 ± 21%; p <0.01). Among patients with decompensated cirrhosis, those who died had a greater decrease in CO with ß-blockers than survivors (21 ± 14% vs. 15 ± 16%; p <0.05) and CO under ß-blockers independently predicted death by competing-risk regression analysis, with good diagnostic accuracy (C-index 0.74; 95% CI 0.66-0.83). Death risk was higher in decompensated patients with CO <5 L/min vs. CO ≥5 L/min (subdistribution hazard ratio 0.44; 95% CI 0.25-0.77; p = 0.004). CONCLUSIONS: In patients with high-risk varices treated to prevent first bleeding, the systemic hemodynamic response to ß-blockers is greater and the portal pressure decrease is smaller in those with decompensated cirrhosis. The short-term effect of ß-blockers on CO might adversely influence survival in decompensated cirrhosis. LAY SUMMARY: ß-blockers are often used to reduce the risk of variceal bleeding in patients with cirrhosis. However, it is not known whether the effect of ß-blockers on arterial pressure and/or cardiac function may offset the benefit of reducing portal pressure. Herein, we show that in patients with decompensated cirrhosis the potentially detrimental systemic effects of ß-blockers are greater than in compensated patients, while the beneficial pressure lowering effects are reduced. The short-term effect of ß-blockers on cardiac output may adversely influence survival in patients with decompensated cirrhosis.