Copper-associated chronic hepatitis in Cavalier King Charles spaniels

BACKGROUND

Copper-associated chronic hepatitis (CuCH) is poorly characterised in Cavalier King Charles spaniels (CKCS).

METHODS

Hepatic copper accumulation was qualitatively and quantitatively assessed, and blood samples were used for genetic testing to screen for known CuCH-associated genetic variants.

RESULTS

The study included 13 CKCS with CuCH and eight unaffected controls. Increased transaminase activities, elevated biliary enzyme concentrations and portal hypertension were documented in 100%, 73% and 38% of dogs with CuCH, respectively. Five dogs had three or more abnormalities in measures of liver function. All 11 dogs with CuCh that underwent genetic testing were homozygous negative for the COMMD1 deletion and ATP7A variant but homozygous positive (n = 7) or heterozygous (n = 4) for the ATP7B variant. Liver histology often demonstrated marked architectural distortion by severe, bridging fibrosis and regenerative nodules with lymphoplasmacytic inflammation. Centrilobular copper accumulation characterised early cases with minimal fibrosis. When fibrosis was significant, copper was often differentially concentrated within regenerative nodules. Chelation therapy resolved laboratory derangements and portal hypertension in five of seven dogs. Of the 7 non-surviving dogs with CuCH, 6 had not received chelation therapy.

LIMITATIONS

Limitations include a small cohort size and the lack of pedigree analyses to corroborate heritability.

CONCLUSIONS

CuCH should be considered in CKCS with suspected liver disease. Long-term prognosis seems favourable in dogs receiving chelation therapy, notwithstanding the presence of previously reported negative prognostic markers.

Percutaneous mesocaval shunt creation for portal thrombosis in a patient with a JAK2V617F mutation

Myeloproliferative neoplasms (MPN) are the most common cause of noncirrhotic, nontumoral portal vein thrombosis (PVT). Over 90 % of MPN patients with PVT carry the JAK2V617F mutation. Compared to other etiologies of PVT, patients with JAK2V617F MPNs are at increased risk of developing significant portal hypertension. However, when these patients develop refractory portal hypertensive complications requiring portosystemic shunt placement, they have limited options. Transjugular intrahepatic portosystemic shunt (TIPS) insertion is often not feasible, as these patients tend to have extensive, occlusive portal thrombus with cavernous transformation. Surgical portosystemic shunt creation can be an alternative; however, this is associated with significant mortality. In this report, we describe the novel use of a percutaneous mesocaval shunt for successful portomesenteric decompression in a patient with portal hypertension from PVT associated with JAK2V617F positive essential thrombocythemia.

Progression of liver disease and portal hypertension in dyskeratosis congenita and related telomere biology disorders

BACKGROUND AND AIMS

Dyskeratosis congenita (DC) and related telomere biology disorders (TBD) are characterized by very short telomeres and multisystem organ involvement including liver disease. Our study aimed to characterize baseline hepatic abnormalities in patients with DC/TBD and determine risk factors associated with liver disease progression.

APPROACH AND RESULTS

A retrospective review was performed on a cohort of 58 patients (39 males) with DC/TBD who were prospectively evaluated at a single institute from 2002 to 2019. The median age at initial assessment was 18 (1.4-67.6) years, and median follow-up duration was 6 (1.4-8.2) years. Patients with autosomal or X-linked recessive inheritance and those with heterozygous TINF2 DC were significantly younger, predominantly male, and more likely to have DC-associated mucocutaneous triad features and severe bone marrow failure compared with autosomal dominant-non- TINF2 DC/TBD patients. Liver abnormality (defined at baseline assessment by laboratory and/or radiological findings) was present in 72.4% of patients with predominantly cholestatic pattern of liver enzyme elevation. Clinically significant liver disease and portal hypertension developed in 17.2% of patients during the 6-year follow-up; this progression was mainly seen in patients with recessive or TINF2 -associated DC. Significant risk factors associated with progression included the presence of pulmonary or vascular disease.

CONCLUSIONS

Our experience shows a high prevalence of cholestatic pattern of liver abnormality with progression to portal hypertension in patients with DC/TBD. Presence of pulmonary and/or vascular disease in patients with recessive or TINF2 DC was an important predictor of liver disease progression, suggesting the need for increased vigilance and monitoring for complications in these patients.

Liver Transplantation in a Woman with Mahvash Disease

Mahvash disease is an exceedingly rare genetic disorder of glucagon signaling characterized by hyperglucagonemia, hyperaminoacidemia, and pancreatic α-cell hyperplasia. Although there is no known definitive treatment, octreotide has been used to decrease systemic glucagon levels. We describe a woman who presented to our medical center after three episodes of small-volume hematemesis. She was found to have hyperglucagonemia and pancreatic hypertrophy with genetically confirmed Mahvash disease and also had evidence of portal hypertension (recurrent portosystemic encephalopathy and variceal hemorrhage) in the absence of cirrhosis. These findings established a diagnosis of portosinusoidal vascular disease, a presinusoidal type of portal hypertension previously known as noncirrhotic portal hypertension. Liver transplantation was followed by normalization of serum glucagon and ammonia levels, reversal of pancreatic hypertrophy, and resolution of recurrent encephalopathy and bleeding varices.

Human liver single nuclear RNA sequencing implicates BMPR2, GDF15, arginine, and estrogen in portopulmonary hypertension

Portopulmonary hypertension (PoPH) is a type of pulmonary vascular disease due to portal hypertension that exhibits high morbidity and mortality. The mechanisms driving disease are unknown, and transcriptional characteristics unique to the PoPH liver remain unexplored. Here, we apply single nuclear RNA sequencing to compare cirrhotic livers from patients with and without PoPH. We identify characteristics unique to PoPH in cells surrounding the central hepatic vein, including increased growth differentiation factor signaling, enrichment of the arginine biosynthesis pathway, and differential expression of the bone morphogenic protein type II receptor and estrogen receptor type I genes. These results provide insight into the transcriptomic characteristics of the PoPH liver and mechanisms by which PoPH cellular dysfunction might contribute to pulmonary vascular remodeling.

The impact of transmembrane 6 superfamily 2 (TM6SF2) rs58542926 on liver-related events in patients with advanced chronic liver disease

BACKGROUND & AIMS

Genetic factors such as the transmembrane 6 superfamily 2 (TM6SF2) rs58542926 single nucleotide variant(SNV) modulate the susceptibility for (advanced) chronic liver disease ([A]CLD). However, the impact of this variant in patients who have already progressed to ACLD is unknown.

METHODS

The association between TM6SF2-rs58542926 genotype and liver-related events was evaluated in 938 ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement.

RESULTS

Mean HVPG was 15±7 mmHg and mean UNOS MELD (2016) 11±5 points. Viral hepatitis (n = 495, 53%) was the most common cause of ACLD, followed by alcohol-related (ARLD; n = 342, 37%) and non-alcoholic fatty liver disease (NAFLD; n = 101, 11%). While 754 (80%) patients harboured the TM6SF2 wild-type (C/C), 174 (19%) and 10 (1%) patients had one or two T-alleles. At baseline, patients with at least one TM6SF2 T-allele had more pronounced portal hypertension (HVPG: 16±7 vs. 15±7 mmHg; p = 0.031), higher gamma-glutamyl transferase levels (123 [63-229] vs. 97 [55-174] UxL-1; p = 0.002), and more commonly hepatocellular carcinoma (17% vs. 12%; p = 0.049). Harbouring the TM6SF2 T-allele was associated with the composite endpoint hepatic decompensation/liver transplantation/liver-related death (SHR: 1.44 [95%CI: 1.14-1.83]; p = 0.003). This was confirmed in multivariable competing risk regression analyses that were adjusted for severity of portal hypertension and hepatic dysfunction at baseline.

CONCLUSION

The TM6SF2 variant modulates liver disease progression beyond the development of ACLD, as it modifies the risks of hepatic decompensation and liver-related death, independently of baseline liver disease severity.

PBMCs gene expression signature of advanced cirrhosis with high risk for clinically significant portal hypertension in HIV/HCV coinfected patients: A cross-control study

BACKGROUND

Patients with advanced cirrhosis are at high risk of developing clinically significant portal hypertension (CSPH). We analyzed the gene expression profile of peripheral blood mononuclear cells (PBMCs) from HIV/HCV coinfected patients to identify a gene expression signature of advanced cirrhosis with high risk for CSPH.

METHODS

We conducted a cross-sectional study on 68 patients. Liver stiffness measurement (LSM) was used to stratify patients into < 12.5 kPa (no cirrhosis, n = 19), 12.5 - 24.9 kPa (cirrhosis, n = 20), and ≥ 25 kPa (advanced cirrhosis with high risk for CSPH, n = 29). Besides, we further evaluated LSM < 25 kPa (n = 39) vs. ≥ 25 kPa (n = 29). Total RNA was extracted from PBMCs, and poly(A) RNA sequencing was performed. Two significant differentially expressed (SDE) transcripts were validated by quantitative PCR in a different cohort (n = 46).

RESULTS

We found 60 SDE transcripts between patients with LSM < 12.5 kPa and ≥ 25 kPa. Partial least squares discriminant analysis showed that those 60 SDE transcripts collectively discriminated LSM ≥ 25 kPa, with an area under the receiver operating characteristic curve (AUROC) of 0.84. Eight genes had an AUROC ≥ 0.75 for LSM ≥ 25 kPa: five were positively associated with LSM values (SCAMP1, ABHD17B, GPR146, GTF2A1, and TMEM64), while three were inversely associated (ZFHX2-AS1, MDK, and STAG3L2). We validated the two SDE transcripts with the highest discrimination capacity in a different cohort, finding significant differences between < 25 kPa and ≥ 25 kPa (MDK (p = 0.006) and STAG3L2 (p = 0.021)).

CONCLUSIONS

A gene expression signature of 60 transcripts was associated with advanced cirrhosis with high risk for CSPH in HIV/HCV coinfected patients.

Protective Effects of Statin Therapy in Cirrhosis Are Limited by a Common SLCO1B1 Transporter Variant

Complications of cirrhosis and portal hypertension (PH) can be reduced by statin therapy. The common loss-of-function variant p.V174A in the solute carrier organic anion transporter gene 1B1 (SLCO1B1) gene encoding the organic anion transporting polypeptide 1B1 results in decreased hepatic uptake of statins. Our specific aim was to assess the impact of this variant in patients with cirrhosis and statin treatment while controlling for the stage of cirrhosis and other potential confounders with propensity score matching (PSM), availing of a large cohort of genotyped study patients. In total, from 1,088 patients with cirrhosis in two German academic medical centers, PSM yielded 154 patients taking statins and 154 matched controls. The effect on PH was assessed by the liver stiffness-spleen size-to-platelet score (LSPS), and complications of cirrhosis were retrospectively recorded applying consensus criteria. As hypothesized, patients on statin treatment presented less frequently with signs of PH: Esophageal varices (41% vs. 62%; P < 0.001) were less common, and LSPS (4.8 ± 11.5 vs. 5.6 ± 6.4; P = 0.01) was reduced. Correspondingly, decompensation events were also reduced in patients on statins (odds ratio [OR] = 0.54, 95% confidence interval [CI] 0.32-0.90; P = 0.02). When the variant in SLCO1B1 was present in patients on statins, esophageal varices (OR = 2.68, 95% CI 1.24-5.81; P = 0.01) and bacterial infections (OR = 2.50, 95% CI 1.14-5.47; P = 0.02) were more common as compared with wild type carriers on statins. Conclusion: In this cohort, signs and complications of PH were reduced in patients with cirrhosis treated with statins. Notably, this effect was diminished by the common loss-of-function variant in SLCO1B1. Further prospective studies in independent cohorts are warranted to confirm these genotype-specific observations.

Estrogen Signaling and Portopulmonary Hypertension: The Pulmonary Vascular Complications of Liver Disease Study (PVCLD2)

BACKGROUND AND AIMS

Portopulmonary hypertension (POPH) was previously associated with a single-nucleotide polymorphism (SNP) rs7175922 in aromatase (cytochrome P450 family 19 subfamily A member 1 [CYP19A1]). We sought to determine whether genetic variants and metabolites in the estrogen signaling pathway are associated with POPH.

APPROACH AND RESULTS

We performed a multicenter case-control study. POPH patients had mean pulmonary artery pressure >25 mm Hg, pulmonary vascular resistance >240 dyn-sec/cm-5 , and pulmonary artery wedge pressure ≤15 mm Hg without another cause of pulmonary hypertension. Controls had advanced liver disease, right ventricular (RV) systolic pressure <40 mm Hg, and normal RV function by echocardiography. We genotyped three SNPs in CYP19A1 and CYP1B1 using TaqMan and imputed SNPs in estrogen receptor 1 using genome-wide markers. Estrogen metabolites were measured in blood and urine samples. There were 37 patients with POPH and 290 controls. Mean age was 57 years, and 36% were female. The risk allele A in rs7175922 (CYP19A1) was significantly associated with higher levels of estradiol (P = 0.02) and an increased risk of POPH (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.12-4.91; P = 0.02) whereas other SNPs were not. Lower urinary 2-hydroxyestrogen/16-α-hydroxyestrone (OR per 1-ln decrease = 2.04; 95% CI, 1.16-3.57; P = 0.01), lower plasma levels of dehydroepiandrosterone-sulfate (OR per 1-ln decrease = 2.38; 95% CI, 1.56-3.85; P < 0.001), and higher plasma levels of 16-α-hydroxyestradiol (OR per 1-ln increase = 2.16; 95% CI, 1.61-2.98; P < 0.001) were associated with POPH.

CONCLUSIONS

Genetic variation in aromatase and changes in estrogen metabolites were associated with POPH.

Prospective evaluation of kidney and liver disease in autosomal recessive polycystic kidney disease-congenital hepatic fibrosis

BACKGROUND AND OBJECTIVES

We have previously published the characteristics of kidney and liver disease in a cohort of 73 individuals with molecularly confirmed autosomal recessive polycystic kidney disease-congenital hepatic fibrosis, based upon cross-sectional data. Here, we present prospective data on the same cohort.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Comprehensive biochemical and imaging data on progression of kidney and liver disease in 60 of the 73 patients were prospectively collected at the NIH Clinical Center on multiple visits between 2003 and 2019.

RESULTS AND CONCLUSIONS

Of the 73 patients, 23 received a renal allograft at an average age of 17.5 years and 10 underwent liver transplantation at an average age of 20.3 years. Patients who presented perinatally and those who had corticomedullary disease required kidney transplantation significantly earlier. The mean eGFR slope in patients with corticomedullary disease was -1.6 ml/min/1.73 m²/y, in comparison to -0.6 ml/min/1.73 m²/y in those with medullary disease. Kidney size remained the same over time and normalized to the upper limit of normal by 20-25 years of age. The extent of renal disease on ultrasound remained largely unchanged; no patient progressed from the "medullary" to the "corticomedullary" group. There was no correlation between eGFR slope and kidney size. The synthetic function of the liver remained largely intact even in patients with advanced portal hypertension. Based on spleen length/height ratio, two thirds of patients had portal hypertension which remained stable in 39% and worsened in 61%. Patients with portal hypertension had lower platelet counts and relatively higher levels of AST, GGT, direct bilirubin and ammonia. The progression rates of kidney and liver disease were independent of each other. Patients with bi-allelic non-truncating PKHD1 variants had similar progression of kidney and liver disease in comparison to those who were compound heterozygous for a non-truncating and a truncating variant.

Short-Term Western Diet Aggravates Non-Alcoholic Fatty Liver Disease (NAFLD) With Portal Hypertension in TGR(mREN2)27 Rats

Non-alcoholic fatty liver disease (NAFLD) is gaining in importance and is linked to obesity. Especially, the development of fibrosis and portal hypertension in NAFLD patients requires treatment. Transgenic TGR(mREN2)27 rats overexpressing mouse renin spontaneously develop NAFLD with portal hypertension but without obesity. This study investigated the additional role of obesity in this model on the development of portal hypertension and fibrosis. Obesity was induced in twelve-week old TGR(mREN2)27 rats after receiving Western diet (WD) for two or four weeks. Liver fibrosis was assessed using standard techniques. Hepatic expression of transforming growth factor-β1 (TGF-β1), collagen type Iα1, α-smooth muscle actin, and the macrophage markers Emr1, as well as the chemoattractant Ccl2, interleukin-1β (IL1β) and tumor necrosis factor-α (TNFα) were analyzed. Assessment of portal and systemic hemodynamics was performed using the colored microsphere technique. As expected, WD induced obesity and liver fibrosis as confirmed by Sirius Red and Oil Red O staining. The expression of the monocyte-macrophage markers, Emr1, Ccl2, IL1β and TNFα were increased during feeding of WD, indicating infiltration of macrophages into the liver, even though this increase was statistically not significant for the EGF module-containing mucin-like receptor (Emr1) mRNA expression levels. Of note, portal pressure increased with the duration of WD compared to animals that received a normal chow. Besides obesity, WD feeding increased systemic vascular resistance reflecting systemic endothelial and splanchnic vascular dysfunction. We conclude that transgenic TGR(mREN2)27 rats are a suitable model to investigate NAFLD development with liver fibrosis and portal hypertension. Tendency towards elevated expression of Emr1 is associated with macrophage activity point to a significant role of macrophages in NAFLD pathogenesis, probably due to a shift of the renin-angiotensin system towards a higher activation of the classical pathway. The hepatic injury induced by WD in TGR(mREN2)27 rats is suitable to evaluate different stages of fibrosis and portal hypertension in NAFLD with obesity.

Impact of HSD17B13 rs72613567 genotype on hepatic decompensation and mortality in patients with portal hypertension

BACKGROUND & AIMS

The loss-of-function rs72613567 T > TA-variant in the 17β-hydroxysteroid dehydrogenase 13 (HSD17B13) gene might protect from alcoholic and non-alcoholic fatty liver disease (ALD/NAFLD) and associated fibrosis/cirrhosis. We investigated the impact of the T > TA-variant on hepatic decompensation and mortality and investigated its implications on retinol and sex steroid metabolism in patients who had already developed advanced chronic liver disease (ACLD).

METHODS

Retrospective analysis in prospectively characterized patients with viral hepatitis- and ALD/NAFLD-induced portal hypertension (hepatic venous pressure gradient (HVPG) ≥ 6 mmHg) diagnosed at the Medical University of Vienna.

RESULTS

Among 487 patients who were followed longitudinally, 166 (34%) were heterozygous and 24 (5%) were homozygous for the 'protective' TA-allele. Patients harbouring at least one TA-allele had a lower MELD (9 (8-12) vs 10 (8-13) points; P = .003) and showed a trend towards lower HVPG (16 ± 6 vs 17 ± 7 mmHg; P = .067). Interestingly, in competing risk analyses adjusted for age, HVPG and MELD, harbouring the TA-allele was associated with numerically increased risks for mortality (adjusted subdistribution hazard ratio (aSHR): 1.3 (95% confidence interval (95% CI): 0.888-1.91); P = .18), liver-related death (aSHR: 1.34 (95% CI: 0.9-1.98); P = .15) and hepatic decompensation (aSHR: 1.29 (95% CI: 0.945-1.77); P = .11). This might be explained by trends towards worse outcomes (eg liver-related death: aSHR: 1.64 (95% CI: 0.95-2.84); P = .076) in patients with viral hepatitis-induced ACLD. In a cross-sectional analysis of 211 additional patients, serum retinol levels were comparable between HSD17B13 genotypes, but in males, serum testosterone levels numerically decreased with an increasing number of TA-alleles.

CONCLUSION

In patients with viral hepatitis- and ALD-induced portal hypertension, the T > TA-variant was not protective of hepatic decompensation and mortality. Further studies should investigate the pathophysiological mechanisms underlying the effects of HSD17B13 genotype at different stages of liver disease.

Impact of farnesoid X receptor single nucleotide polymorphisms on hepatic decompensation and mortality in cirrhotic patients with portal hypertension

BACKGROUND AND AIM

The nuclear farnesoid X receptor (FXR) regulates critical pathways of hepatic metabolism, inflammation, and gut mucosal barrier. Thus, we investigated the association of FXR-single nucleotide polymorphism (SNPs) with hepatic decompensation and liver-related mortality in patients with advanced chronic liver disease.

METHODS

Two FXR-SNPs (rs56163822 G > T and rs35724 G > C) were genotyped in a cohort of 402 prospectively characterized patients with hepatic venous pressure gradient (HVPG) ≥ 6 mmHg.

RESULTS

Only 19 patients (4.7%) harbored a rs56163822 T-allele and had less pronounced liver disease as indicated by lower Child-Pugh score (CPS, 6 ± 1 vs 7 ± 2 points, P = 0.034) and higher albumin levels (38.9 ± 4.9 vs 35.9 ± 5.9 g/L, P = 0.026). In contrast, n = 267 (66.4%) patients harbored minor rs35724 allele (G/C or C/C) and had more advanced liver disease, as indicated by a higher model of end-stage liver disease (11 ± 4 vs 10 ± 3, P = 0.016), while other baseline characteristics were similar across FXR-SNP genotypes. In compensated CPS-A patients, the rs35724 minor allele was independently protective for the development of ascites (adjusted hazard ratio [aHR] = 0.411, 95% confidence interval (95% CI): 0.191-0.885; P = 0.023) and tended to reduce the risk of hepatic decompensation (aHR = 0.625, 95% CI: 0.374-1.044, P = 0.072) in multivariate analyses. Of note, transplant-free survival was longer in patients with rs35724 minor allele and HVPG ≥ 10 mmHg (at 5 years: 68.2% vs 55.8%, P = 0.047) and those with HVPG ≥ 16 mmHg (63.3% vs 44.0%, P = 0.021). After adjusting for established risk factors, the rs35724 minor allele was independently associated with reduced liver-related mortality in the overall cohort (aHR = 0.658, 95% CI: 0.434-0.998, P = 0.049), in compensated CPS-A patients (aHR = 0.488, 95% CI: 0.252-0.946, P = 0.034), in patients with HVPG ≥ 10 mmHg (aHR = 0.547, 95% CI: 0.346-0.864, P = 0.010), and in patients with HVPG ≥ 16 mmHg (aHR = 0.519, 95% CI: 0.307-0.878, P = 0.014).

CONCLUSION

The FXR-SNP rs35724 was associated with a reduced risk for development of ascites and liver-related mortality in patients with advanced chronic liver disease.

Integrated analysis of microRNA and mRNA expression profiles in splenomegaly induced by non-cirrhotic portal hypertension in rats

The spleen plays an important role in the immune and hematopoietic systems. Splenomegaly is a frequent consequence of portal hypertension, but the underlying molecular and cellular mechanisms remain to be fully elucidated. In this study, we have performed a whole-genome microarray analysis combined with histological examination in enlarged spleens isolated from rats with partial portal vein ligation (PPVL) surgery to provide comprehensive profiles of microRNAs and their target mRNAs with a focus on their potential biological functions. A total of 964 mRNAs and 30 microRNAs showed significant differential expression in the spleens of PPVL rats compared to rats undergoing a sham procedure. Twenty-two down-regulated microRNAs were associated with significantly increased genes highly involved in fibrogenic activity and cell proliferation/migration (e.g., Ctgf, Serpine1, Col1a1). Consistently, histological analyses demonstrated increased splenic fibrosis and cell proliferation in the spleens of PPVL rats. Eight up-regulated microRNAs were associated with suppression of genes that are related to interferon-mediated antiviral activity in innate immune responses (e.g., Irf7, Dhx58). In conclusion, we determined a specific microRNA-mRNA network potentially implicated in the tissue fibrosis and cell proliferation in portal hypertension-induced splenomegaly. Our findings provide new insight into the mechanisms for regulation of spleen structure and function.

Prevalence and predictors of liver fibrosis evaluated by vibration controlled transient elastography in type 1 Gaucher disease

BACKGROUND & AIMS

Long-term liver-related complications of Gaucher disease (GD) include cirrhosis, portal hypertension and hepatocellular carcinoma. Although liver fibrosis is the main determinant of adverse liver-related clinical outcomes, it has rarely been evaluated in previously published cohorts of GD patients. We aimed at: assessing the prevalence of significant liver fibrosis in a cohort of patients with type 1 GD; identifying its predictors among GD-related variables, enzyme replacement therapy (ERT) and metabolic features.

METHODS

37 adult type 1 GD patients from two Italian academic referral centers were prospectively submitted to vibration controlled transient elastography (Fibroscan®); significant fibrosis was defined as liver stiffness ≥7 kPa.

RESULTS

Median liver stiffness was 4.6 [3-15.1] kPa and 7 patients (19%) had significant fibrosis. Significant fibrosis was associated with splenectomy (p = .046) and with scores (DS3: p = .002; SSI: p = .026) and biomarkers (ACE: p = .016; HDL cholesterol: p = .004) of GD severity. Length of ERT was significantly lower in GD patients with significant fibrosis. In the subgroup of 29 patients who were on stable ERT for at least 24 months, further to splenectomy, GD severity and non-N370S GBA1 genotypes, also diastolic blood pressure, BMI and the number of metabolic syndrome (MetS) components emerged as factors significantly associated with significant fibrosis.

CONCLUSIONS

Significant fibrosis is present in a remarkable proportion of adult type 1 GD patients. Splenectomy, GD severity and GBA1 genotypes are major GD-related predictors of liver fibrosis. Length of ERT is inversely correlated with liver disease in GD patients, suggesting a beneficial effect of ERT on liver fibrosis. However, GD patients on stable ERT should be monitored for metabolic complications, since MetS features may enhance liver disease progression despite optimal GD control.

Protective effects of hydrogen sulfide on portal hypertensive vasculopathy in rabbits by activating AKT-NF-κB pathway

The role of hydrogen sulfide (H₂S) in portal hypertension (PH)-induced esophagus-gastric junction vascular lesions in rabbits was observed. The rabbit PH models were established. The animals were randomly divided into the following groups: normal, PH, PH+sodium hydrosulfide (PH+S), PH+propargylglycine (PH+PPG). The plasma H₂S levels, apoptosis of esophageal-gastric junction vascular smooth muscle cells, and the expression of nuclear transcription factor-κB (NF-κB), p-AKT, IκBa and Bcl-2 were detected. The cystathionine γ lyase (cystathionine-gamma-splitting enzyme, CSE) in the junction vascular tissue was measured. The results showed that the plasma H₂S levels and the CSE expression levels had statistically significant difference among different groups (P<0.05). As compared with PH group, plasma H₂S levels were declined obviously (11.9±4.2 vs. 20.6±4.5, P<0.05), and CSE expression levels in the junction vascular tissue were notably reduced (1.7±0.6 vs. 2.8±0.8, P<0.05), apoptosis rate of vascular smooth muscle cells per unit area was significantly decreased (0.10±0.15 vs. 0.24±0.07, P<0.05), and the expression levels of p-AKT and NF-κB were significantly decreased (2.31±0.33 vs. 3.04±0.38, P<0.05; 0.33±0.17 vs. 0.51±0.23, P<0.05), however, IκBa and Bcl-2 expression increased obviously (5.57±0.17 vs. 3.67±0.13, P<0.05; 0.79±0.29 vs. 0.44±0.36, P<0.05) in PH+PPG group. As compared with PH group, H₂S levels were notably increased (32.7±7.3 vs. 20.6±4.5, P<0.05), the CSE levels in the junction vascular tissue were significantly increased (6.3±0.7 vs. 2.8±0.8, P<0.05), apoptosis rate of vascular smooth muscle cells per unit area was significantly increased (0.35±0.14 vs. 0.24±0.07, P<0.05), and the expression levels of p-AKT and NF-κB were significantly increased (4.29±0.49 vs. 3.04±0.38, P<0.05; 0.77±0.27 vs. 0.51±0.23, P<0.05), yet IκBa and Bcl-2 expression decreased significantly (3.23±0.24 vs. 3.67±0.13, P<0.05; 0.31±0.23 vs. 0.48±0.34, P<0.05) in PH+S group. It is concluded that esophagus-gastric junction vascular lesions happen under PH, and apoptosis of smooth muscle cells is declined. H₂S can activate NF-κB by the p-AKT pathway, leading to the down-regulation of Bcl-2, eventually stimulating apoptosis of vascular smooth muscle cells, easing PH. H₂S/CSE system may play an important role in remission of PH via the AKT-NF-κB pathway.

N-acetylcysteine modulates angiogenesis and vasodilation in stomach such as DNA damage in blood of portal hypertensive rats

AIM: To evaluate the antioxidant effect of N-acetylcysteine (NAC) on the stomach of rats with portal hypertension.

METHODS: Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups (n = 6 each): Sham-operated (SO), SO + NAC, partial portal vein ligation (PPVL), and PPVL + NAC. Treatment with NAC in a dose of 10 mg/kg (i.p.) diluted in 0.6 mL of saline solution was administered daily for 7 d starting 8 d after the surgery. Animals from the PPVL and SO group received saline solution (0.6 mL) for the same period of time as the PPVL + NAC and SO + NAC group. On the 15^th day the animals were anesthetized and we evaluated portal pressure by cannulating mesenteric artery. After, we removed the stomach for further analysis. We performed immunohistochemical analysis for endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and nitrotirosine (NTT) proteins in stomach. We also evaluated eNOS and VEGF by Western blot analysis and assessed DNA damage in blood samples by the comet assay.

RESULTS: The portal hypertension group exhibited increases in portal pressure when compared to SO group (29.8 ± 1.8 vs 12.0 ± 0.3 mmHg) (P < 0.001). The same was observed when we compared the eNOS (56.8 ± 3.7 vs 13.46 ± 2.8 pixels) (P < 0.001), VEGF (34.9 ± 4.7 vs 17.46 ± 2.6 pixels) (P < 0.05), and NTT (39.01 ± 4.0 vs 12.77 ± 2.3 pixels) (P < 0.05) expression by immunohistochemistry of the PPVL animals with the SO group. The expression of eNOS (0.39 ± 0.03 vs 0.25 ± 0.03 a.μ) (P < 0.01) and VEGF (0.38 ± 0.04 vs 0.26 ± 0.04 a.μ) (P < 0.01) were also evaluated by Western blot analysis, and we observed an increase of both proteins on PPVL animals. We also evaluated the DNA damage by comet assay, and observed an increase on damage index and damage frequency on those animals. NAC decreased portal pressure values in PPVL + NAC animals (16.46 ± 2 vs 29.8 ± 1.8 mmHg) (P < 0.001) when compared to PPVL. The expression of eNOS (14.60 ± 4.1 vs 56.8 ± 3.7 pixels) (P < 0.001), VEGF (19.53 ± 3.2 vs 34.9 ± 4.7 pixels) (P < 0.05) and NTT (21.84 ± 0.7 vs 39.01 ± 4.0 pixels) (P < 0.05) evaluated by immunohistochemistry were also reduced in PPVL + NAC animals. Also, when evaluated by Western blot eNOS expression (0.32 ± 0.03 vs 0.39 ± 0.03 a.μ) (P < 0.05) and VEGF expression (0.31 ± 0.09 vs 0.38 ± 0.04 a.μ) (P < 0.01). Furthermore, NAC modulated DNA damage in PPVL + NAC animals.

CONCLUSION: In view of these results, we believe NAC is able to protect the stomach from the alterations induced by the PPVL procedure.

β-Arrestin-1 protects against endoplasmic reticulum stress/p53-upregulated modulator of apoptosis-mediated apoptosis via repressing p-p65/inducible nitric oxide synthase in portal hypertensive gastropathy

Portal hypertensive gastropathy (PHG) is a serious cause of bleeding in patients, and is associated with portal hypertension. β-Arrestins (β-arrestin-1 and β-arrestin-2) are well-established mediators of endocytosis of G-protein-coupled receptors (GPCRs), ubiquitination, and G-protein-independent signaling. The role of β-arrestin-1 (β-arr1) in mucosal apoptosis in PHG remains unclear. The aim of this study was to investigate the involvement of β-arr1 in PHG via its regulation of endoplasmic reticulum (ER) stress/p53-upregulated modulator of apoptosis (PUMA) apoptotic signaling. Gastric mucosal injury and apoptosis were studied in PHG patients and in PHG mouse models. The induction of β-arr1 and the ER stress/PUMA signaling pathway were investigated, and the mechanisms of β-arr1-regulated gastric mucosal apoptosis were analyzed in vivo and in vitro experiments. β-arr1 and ER stress/PUMA signaling elements were markedly induced in the gastric mucosa of PHG patients and mouse models. Blockage of ER stress demonstrably attenuated the mucosal apoptosis of PHG, while targeted deletion of β-arr1 significantly aggravated the injury and ER stress/PUMA-mediated apoptosis. β-arr1 limited the activation of p65 to repress TNF-α-induced inducible nitric oxide synthase (iNOS) expression and NO release, which could regulate ER stress/PUMA-mediated mucosal apoptosis in PHG. In vivo and in vitro experiments further demonstrated that β-arr1 protected against mucosal apoptosis by repressing TNF-α-induced iNOS expression via inhibiting the activation of p65. These results indicated that β-arr1 regulated ER stress/PUMA-induced mucosal epithelial apoptosis through suppression of the TNF-α/p65/iNOS signaling pathway activation and that β-arr1 is a potential therapeutic target for PHG.

MiR-9a-5p regulates proliferation and migration of hepatic stellate cells under pressure through inhibition of Sirt1

AIM: To reveal the functions of microRNAs (miRNAs) with respect to hepatic stellate cells (HSCs) in response to portal hypertension.

METHODS: Primary rat HSCs were exposed to static water pressure (10 mmHg, 1 h) and the pressure-induced miRNA expression profile was detected by next-generation sequencing. Quantitative real-time polymerase chain reaction was used to verify the expression of miRNAs. A potential target of MiR-9a-5p was measured by a luciferase reporter assay and Western blot. CCK-8 assay and Transwell assay were used to detect the proliferation and migration of HSCs under pressure.

RESULTS: According to the profile, the expression of miR-9a-5p was further confirmed to be significantly increased after pressure overload in HSCs (3.70 ± 0.61 vs 0.97 ± 0.15, P = 0.0226), which resulted in the proliferation, migration and activation of HSCs. In vivo, the up-regulation of miR-9a-5p (2.09 ± 0.91 vs 4.27 ± 1.74, P = 0.0025) and the down-regulation of Sirt1 (2.41 ± 0.51 vs 1.13 ± 0.11, P = 0.0006) were observed in rat fibrotic liver with portal hypertension. Sirt1 was a potential target gene of miR-9a-5p. Through restoring the expression of Sirt1 in miR-9a-5p transfected HSCs on pressure overload, we found that overexpression of Sirt1 could partially abrogate the miR-9a-5p mediated suppression of the proliferation, migration and activation of HSCs.

CONCLUSION: Our results suggest that during liver fibrosis, portal hypertension may induce the proliferation, migration and activation of HSCs through the up-regulation of miR-9a-5p, which targets Sirt1.

β-2 Adrenergic receptor gene polymorphism and response to propranolol in cirrhosis

AIM: To evaluate the association of β-2 adrenergic receptor (β₂-AR) gene polymorphism with response of variceal pressure to propranolol in cirrhosis.

METHODS: Sixty-four non-related cirrhotic patients participated in this study and accepted variceal pressure measurement before and after propranolol administration. Polymorphism of the β₂-AR gene was determined by directly sequencing of the polymerase chain reaction products from the DNA samples that were prepared from the patients.

RESULTS: The prevalence of Gly16-Glu/Gln27 and Arg16-Gln27 homozygotes, and compound heterozygotes was 29.7%, 10.9%, and 59.4%, respectively. Patients with cirrhosis with Gly16-Glu/Gln27 homozygotes had a greater decrease of variceal pressure after propranolol administration than those with Arg16-Gln27 homozygotes or with compound heterozygotes (22.4% ± 2.1%, 13.1% ± 2.7% and 12.5% ± 3.1%, respectively, P < 0.01).

CONCLUSION: The variceal pressure response to propranolol was associated with polymorphism of β₂-AR gene. Patients with the Gly¹⁶-Glu/Gln²⁷ homozygotes probably benefit from propranolol therapy.

Murine study of portal hypertension associated endothelin-1 hypo-response

AIM: To investigate endothelin-1 hypo-responsive associated with portal hypertension in order to improve patient treatment outcomes.

METHODS: Wild type, eNOS^-/- and iNOS^-/- mice received partial portal vein ligation surgery to induce portal hypertension or sham surgery. Development of portal hypertension was determined by measuring the splenic pulp pressure, abdominal aortic flow and portal systemic shunting. To measure splenic pulp pressure, a microtip pressure transducer was inserted into the spleen pulp. Abdominal aortic flow was measured by placing an ultrasonic Doppler flow probe around the abdominal aorta between the diaphragm and celiac artery. Portal systemic shunting was calculated by injection of fluorescent microspheres in to the splenic vein and determining the percentage accumulation of spheres in liver and pulmonary beds. Endothelin-1 hypo-response was evaluated by measuring the change in abdominal aortic flow in response to endothelin-1 intravenous administration. In addition, thoracic aorta endothelin-1 contraction was measured in 5 mm isolated thoracic aorta rings ex-vivo using an ADI small vessel myograph.

RESULTS: In wild type and iNOS^-/- mice splenic pulp pressure increased from 7.5 ± 1.1 mmHg and 7.2 ± 1 mmHg to 25.4 ± 3.1 mmHg and 22 ± 4 mmHg respectively. In eNOS^-/- mice splenic pulp pressure was increased after 1 d (P = NS), after which it decreased and by 7 d was not significantly elevated when compared to 7 d sham operated controls (6.9 ± 0.6 mmHg and 7.3 ± 0.8 mmHg respectively, P = 0.3). Abdominal aortic flow was increased by 80% and 73% in 7 d portal vein ligated wild type and iNOS when compared to shams, whereas there was no significant difference in 7 d portal vein ligated eNOS^-/- mice when compared to shams. Endothelin-1 induced a rapid reduction in abdominal aortic blood flow in wild type, eNOS^-/- and iNOS^-/- sham mice (50% ± 8%, 73% ± 9% and 47% ± 9% respectively). Following portal vein ligation endothelin-1 reduction in blood flow was significantly diminished in each mouse group. Abdominal aortic flow was reduced by 19% ± 9%, 32% ± 10% and 9% ± 9% in wild type, eNOS^-/- and iNOS^-/- mice respectively.

CONCLUSION: Aberrant endothelin-1 response in murine portal hypertension is NOS isoform independent. Moreover, portal hypertension in the portal vein ligation model is independent of ET-1 function.

Thalidomide ameliorates portal hypertension via nitric oxide synthase independent reduced systolic blood pressure

AIM: Portal hypertension is a common complication of liver cirrhosis and significantly increases mortality and morbidity. Previous reports have suggested that the compound thalidomide attenuates portal hypertension (PHT). However, the mechanism for this action is not fully elucidated. One hypothesis is that thalidomide destabilizes tumor necrosis factor α (TNFα) mRNA and therefore diminishes TNFα induction of nitric oxide synthase (NOS) and the production of nitric oxide (NO). To examine this hypothesis, we utilized the murine partial portal vein ligation (PVL) PHT model in combination with endothelial or inducible NOS isoform gene knockout mice.

METHODS: Wild type, inducible nitric oxide synthase (iNOS)^-/- and endothelial nitric oxide synthase (eNOS)^-/- mice received either PVL or sham surgery and were given either thalidomide or vehicle. Serum nitrate (total nitrate, NOx) was measured daily for 7 d as a surrogate of NO synthesis. Serum TNFα level was quantified by enzyme-linked immunosorbent assay. TNFα mRNA was quantified in liver and aorta tissue by reverse transcription-polymerase chain reaction. PHT was determined by recording splenic pulp pressure (SPP) and abdominal aortic flow after 0-7 d. Response to thalidomide was determined by measurement of SPP and mean arterial pressure (MAP).

RESULTS: SPP, abdominal aortic flow (Qao) and plasma NOx were increased in wild type and iNOS^-/- PVL mice when compared to sham operated control mice. In contrast, SPP, Qao and plasma NOx were not increased in eNOS^-/- PVL mice when compared to sham controls. Serum TNFα level in both sham and PVL mice was below the detection limit of the commercial ELISA used. Therefore, the effect of thalidomide on serum TNFα levels was undetermined in wild type, eNOS^-/- or iNOS^-/- mice. Thalidomide acutely increased plasma NOx in wild type and eNOS^-/- mice but not iNOS^-/- mice. Moreover, thalidomide temporarily (0-90 min) decreased mean arterial pressure, SPP and Qao in wild type, eNOS^-/- and iNOS^-/- PVL mice, after which time levels returned to the respective baseline.

CONCLUSION: Thalidomide does not reduce portal pressure in the murine PVL model by modulation of NO biosynthesis. Rather, thalidomide reduces PHT by decreasing MAP by an undetermined mechanism.

A new Mdr2(-/-) mouse model of sclerosing cholangitis with rapid fibrosis progression, early-onset portal hypertension, and liver cancer

We previously characterized the Mdr2(Abcb4)(-/-) mouse as a reproducible model of chronic biliary liver disease. However, it demonstrates relatively slow fibrosis progression, possibly due to its fibrosis-resistant genetic background. We aimed to improve the model by moving it onto a fibrosis-susceptible background. We generated novel BALB/c.Mdr2(-/-) mouse via genetic backcross onto highly fibrosis-susceptible BALB/c substrain, identified in inbred mouse strain screening. Liver fibrosis, portal pressure, and hepatic tumor burden in BALB/c.Mdr2(-/-) mice were studied up to 1 year of age in direct comparison to parental strain FVB.Mdr2(-/-). BALB/c.Mdr2(-/-) mice developed periductular onion-skin type fibrotic lesions and pronounced ductular reaction starting from 4 weeks of age. Compared to parental strain, BALB/c.Mdr2(-/-) mice demonstrated dramatically accelerated liver fibrosis, with threefold increase in collagen deposition and bridging fibrosis/early signs of cirrhosis at 12 weeks. This was accompanied by early-onset severe portal hypertension and twofold to fourfold increase in profibrogenic transcripts Col1a1 [procollagen α1(I)], Tgfb1, and Timp1. Primary liver cancers in BALB/c.Mdr2(-/-) developed earlier, with greater tumor burden compared to FVB.Mdr2(-/-). BALB/c.Mdr2(-/-) mice have unprecedented degree and rapidity of hepatic fibrosis progression and clinically relevant cirrhosis complications, such as early-onset portal hypertension and primary liver cancers. This new model will facilitate development of antifibrotic drugs and studies into mechanisms of biliary fibrosis progression.

Novel LIPA mutations in Mexican siblings with lysosomal acid lipase deficiency

Lysosomal acid lipase (LAL) deficiency is an under-recognized lysosomal disease caused by deficient enzymatic activity of LAL. In this report we describe two affected female Mexican siblings with early hepatic complications. At two months of age, the first sibling presented with alternating episodes of diarrhea and constipation, and later with hepatomegaly, elevated transaminases, high levels of total and low-density lipoprotein cholesterol, and low levels of high-density lipoprotein. Portal hypertension and grade 2 esophageal varices were detected at four years of age. The second sibling presented with hepatomegaly, elevated transaminases and mildly elevated low-density lipoprotein and low high-density lipoprotein at six months of age. LAL activity was deficient in both patients. Sequencing of LIPA revealed two previously unreported heterozygous mutations in exon 4: c.253C>A and c.294C>G. These cases highlight the clinical continuum between the so-called Wolman disease and cholesteryl ester storage disease, and underscore that LAL deficiency represents a single disease with a degree of clinical heterogeneity.

Amelioration of carbon tetrachloride-induced cirrhosis and portal hypertension in rat using adenoviral gene transfer of Akt

AIM: To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride (CCl₄).

METHODS: Using cre-loxp technique, we created an Ad-myr-HA-Akt virus, in which Akt is labeled by a HA tag and its expression is driven by myr promoter. Further, through measuring enzyme levels and histological structure, we determined the efficacy of this Ad-myr-HA-Akt virus in inhibiting the development of cirrhosis induced by CCl₄ in rats. Lastly, using western blotting, we examined the expression levels and/or phosphorylation status of Akt, apoptotic mediators, endothelial nitric oxide synthase (eNOS), and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus.

RESULTS: The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment, which was consistent with the sequence reported in the GenBank. The concentrations of Ad-myr-HA-Akt and adenoviral enhanced green fluorescent protein (Ad-EGFP) virus used in the current study were 5.5 × 10¹¹ vp/mL. The portal vein diameter, peak velocity of blood flow, portal blood flow and congestion index were significantly increased in untreated, saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection. In contrast, these parameters in the Akt cirrhosis group were comparable to normal control group. Compared to the normal control, the liver function (Alanine aminotransferase, Aspartate aminotransferase and Albumin) was significantly impaired in the untreated, saline and Ad-EGFP cirrhosis groups. The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated, saline and Ad-EGFP cirrhosis groups. The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups. The results of HE and Van Gieson staining indicated that Akt group has better preservation of histological structure and less fibrosis than other cirrhosis groups. The percentage of apoptotic cell was greatly less in Akt cirrhosis group than in other cirrhosis groups. Akt group showed positive HA tag and an increased level of phosphorylated Akt as well as decreased levels of Fas. In contrast, Caspase-3 and Caspase-9 levels in Akt group were significantly lower than other cirrhosis groups. Noticeable decrease of DR5 and α-SMA and increase of phosphorylated eNOS were observed in the Akt group when compared to other cirrhosis groups. The NO level in liver was significantly higher in Akt group than other cirrhosis groups, which was consistent with the level of phosphorylated eNOS in these groups.

CONCLUSION: This study suggest that Ad-myr-HA-Akt virus is a useful tool to prevent CCl₄-induced cirrhosis in rat model and Akt pathway may be a therapeutic target for human cirrhosis.

[Non-cirrhotic portal hypertension with nearly lethal consequences]

We describe the case of a 48-year-old patient presenting with abdominal pain with a history of cerebral ischemia due to a patent foramen ovale with heterozygous factor V mutation. Initial work-up demonstrate a significant thrombosis of the portal venous system combined with signs of portal hypertension (ascites, oesophageal varices). Ultrasound reveals no signs of cirrhosis of the liver. Finally a JAK2 mutation can be detected. Prevention of oesophageal varices is refused. Finally a massive haemorrhage occured.

Autoimmune polyglandular syndrome III in a patient with idiopathic portal hypertension

A 42-year-old woman with a history of idiopathic portal hypertension (IPH) developed type 1A diabetes and was found to have chronic thyroiditis. The concurrence of IPH and type 1A diabetes has been previously reported in only one case. This is the second known case, and our patient was classified as having autoimmune polyglandular syndrome (APS) III. The patient's HLA DR and DQ alleles were determined to be susceptible to autoimmune thyroid diseases but resistant to type 1A diabetes.

Morphological and biomechanical remodeling of the hepatic portal vein in a swine model of portal hypertension

OBJECTIVES

To obtain the morphological and biomechanical remodeling of portal veins in swine with portal hypertension (PHT), so as to provide some mechanical references and theoretical basis for clinical practice about PHT.

METHODS

Twenty white pigs were used in this study, 14 of them were subjected to both carbon tetrachloride- and pentobarbital-containing diet to induce experimental liver cirrhosis and PHT, and the remaining animals served as the normal controls. The morphological remodeling of portal veins was observed. Endothelial nitric oxide synthase expression profile in the vessel wall was assessed at both mRNA and protein level. The biomechanical changes of the hepatic portal veins were evaluated through assessing the following indicators: the incremental elastic modulus, pressure-strain elastic modulus, volume elastic modulus, and the incremental compliance.

RESULTS

The swine PHT model was successfully established. The percentages for the microstructural components and the histological data significantly changed in the experimental group. Endothelial nitric oxide synthase expression was significantly downregulated in the portal veins of the experimental group. Three incremental elastic moduli (the incremental elastic modulus, pressure-strain elastic modulus, and volume elastic modulus) of the portal veins from PHT animals were significantly larger than those of the controls (P < 0.05), whereas the incremental compliance of hepatic portal vein decreased.

CONCLUSIONS

Our study suggests that the morphological and biomechanical properties of swine hepatic portal veins change significantly during the PHT process, which may play a critical role in the development of PHT and serve as potential therapeutic targets during clinical practice.

A transgenic model for conditional induction and rescue of portal hypertension reveals a role of VEGF-mediated regulation of sinusoidal fenestrations

Portal hypertension (PH) is a common complication and a leading cause of death in patients with chronic liver diseases. PH is underlined by structural and functional derangement of liver sinusoid vessels and its fenestrated endothelium. Because in most clinical settings PH is accompanied by parenchymal injury, it has been difficult to determine the precise role of microvascular perturbations in causing PH. Reasoning that Vascular Endothelial Growth Factor (VEGF) is required to maintain functional integrity of the hepatic microcirculation, we developed a transgenic mouse system for a liver-specific-, reversible VEGF inhibition. The system is based on conditional induction and de-induction of a VEGF decoy receptor that sequesters VEGF and preclude signaling. VEGF blockade results in sinusoidal endothelial cells (SECs) fenestrations closure and in accumulation and transformation of the normally quiescent hepatic stellate cells, i.e. provoking the two processes underlying sinusoidal capillarization. Importantly, sinusoidal capillarization was sufficient to cause PH and its typical sequela, ascites, splenomegaly and venous collateralization without inflicting parenchymal damage or fibrosis. Remarkably, these dramatic phenotypes were fully reversed within few days from lifting-off VEGF blockade and resultant re-opening of SECs' fenestrations. This study not only uncovered an indispensible role for VEGF in maintaining structure and function of mature SECs, but also highlights the vasculo-centric nature of PH pathogenesis. Unprecedented ability to rescue PH and its secondary manifestations via manipulating a single vascular factor may also be harnessed for examining the potential utility of de-capillarization treatment modalities.

Genetic modifiers of liver disease in cystic fibrosis

CONTEXT

A subset (approximately 3%-5%) of patients with cystic fibrosis (CF) develops severe liver disease with portal hypertension.

OBJECTIVE

To assess whether any of 9 polymorphisms in 5 candidate genes (alpha(1)-antitrypsin or alpha(1)-antiprotease [SERPINA1], angiotensin-converting enzyme [ACE], glutathione S-transferase [GSTP1], mannose-binding lectin 2 [MBL2], and transforming growth factor beta1 [TGFB1]) are associated with severe liver disease in patients with CF.

DESIGN, SETTING, AND PARTICIPANTS

Two-stage case-control study enrolling patients with CF and severe liver disease with portal hypertension (CFLD) from 63 CF centers in the United States as well as 32 in Canada and 18 outside of North America, with the University of North Carolina at Chapel Hill as the coordinating site. In the initial study, 124 patients with CFLD (enrolled January 1999-December 2004) and 843 control patients without CFLD were studied by genotyping 9 polymorphisms in 5 genes previously studied as modifiers of liver disease in CF. In the second stage, the SERPINA1 Z allele and TGFB1 codon 10 genotype were tested in an additional 136 patients with CFLD (enrolled January 2005-February 2007) and 1088 with no CFLD.

MAIN OUTCOME MEASURES

Differences in distribution of genotypes in patients with CFLD vs patients without CFLD.

RESULTS

The initial study showed CFLD to be associated with the SERPINA1 Z allele (odds ratio [OR], 4.72; 95% confidence interval [CI], 2.31-9.61; P = 3.3 x 10(-6)) and with TGFB1 codon 10 CC genotype (OR, 1.53; 95% CI, 1.16-2.03; P = 2.8 x 10(-3)). In the replication study, CFLD was associated with the SERPINA1 Z allele (OR, 3.42; 95% CI, 1.54-7.59; P = 1.4 x 10(-3)) but not with TGFB1 codon 10. A combined analysis of the initial and replication studies by logistic regression showed CFLD to be associated with SERPINA1 Z allele (OR, 5.04; 95% CI, 2.88-8.83; P = 1.5 x 10(-8)).

CONCLUSIONS

The SERPINA1 Z allele is a risk factor for liver disease in CF. Patients who carry the Z allele are at greater risk (OR, approximately 5) of developing severe liver disease with portal hypertension.

Domino effect from hypertriglyceridemia to sinistral portal hypertension

Patient with hypertriglyceridemia history tends to develop a pancreatitis episode. Triglyceride levels > 1000 mg/dl may trigger this pathology. Amylase is not a good predictor for pancreatitis associated with hypertriglyceridemia. Because of the close relation between pancreas and splenic vein, pancreatitis is the most common etiologic factor in developing thrombosis or occlusion in splenic vein. The impairment or cessation of venous flow in splenic vein results in back pressure which is transmitted through short gastric and gastroepiploic veins and subsequently via the coronary vein into the portal system. Increased flow across the short gastric veins creates sinistral portal hypertension. Recurrent upper gastrointestinal hemorrhage is the last scene of this sequence in general, and may be unique sign. This case is extremely rare to understand all the cascade mechanism at once.

Down-regulation of genes related to the adrenergic system may contribute to splanchnic vasodilation in rat portal hypertension

BACKGROUND/AIMS

Splanchnic vasodilation initiates the hyperdynamic syndrome in portal hypertension. We aimed to explore molecular mechanisms involved in the development of mesenteric vasodilation in portal hypertension.

METHODS

Superior mesenteric artery (SMA) samples from portal vein ligated (PVL) and sham rats were compared in a time course experiment using DNA microarrays. Selected genes were quantified by qRT-PCR in PVL and cirrhotic rats. Inmunohistochemistry of tyrosine hydroxylase (Th) and norepinephrine was assessed in SMA sections of PVL and sham rats. Western blot analysis of Th, dopamine beta-hydroxylase (Dbh) and synaptosome-associated protein (Snap-25) was performed in SMA and jejunum samples from the animal models.

RESULTS

Fifty differentially expressed genes implicated in neurotransmission, especially adrenergic, were detected in SMA samples from PVL rats. Sequential analysis showed a profound down-regulation at 14 days in PVL rats. These down-regulated genes were confirmed by RT-PCR in SMA from PVL and cirrhotic rats. Th and NE detection by immunohistochemistry was reduced in PVL compared to sham. Th, Dbh and Snap-25 expression was lower in SMA from 14-day PVL and cirrhotic rats compared to sham and control rats, respectively.

CONCLUSIONS

Genetic down-regulation of genes related to the adrenergic system might have a role in splanchnic vasodilation of portal hypertension.

[cDNA microarray-based screening of differentially expressed genes in macrophages in the spleen of patients with portal hypertension and hypersplenism]

OBJECTIVE

To identify the differentially expressed genes associated with hypersplenism in patients with portal hypertension.

METHODS

The total RNA were extracted from the macrophages isolated from normal spleen and the spleen of patients with portal hypertension and reversely transcribed to cDNA with the incorporation of fluorescent (cy3 and cy5)-labeled dCTP to prepare the hybridization probes. After hybridization of Biostar-H140s chip containing 14,112 spots of cDNAs with the prepared probes, the gene chip was scanned for fluorescence intensity to screen the differently expressed genes. Three gene chips were used for hybridization and only the genes with differential expression in all the three chips were considered to associate with hypersplenism in patients with portal hypertension.

RESULTS

Totaling 896, 1330 and 898 genes were identified to be differentially expressed by the three chips, respectively, and 121 genes (0.86%) showed differential expression in all the three chips, including 21 up-regulated known genes and 73 down-regulated known genes. The differently expressed genes were functionally related with ion channels and transport proteins, cyclins, cytoskeleton, cell receptors, cell signal transduction, metabolism, immunity, and so forth. These genes might be involved in hypersplenism in the condition of portal hypertension.

CONCLUSION

cDNA microarray-based screening of differentially expressed genes in the macrophages in the spleen may provide new insights into the pathogenesis of hypersplenism in patients with portal hypertension.

Evolving dilemmas and management of portopulmonary hypertension

Portopulmonary hypertension (POPH) is an uncommon but serious pulmonary vascular consequence of portal hypertension. Untreated, POPH results in right heart failure and death, regardless of the severity of portal hypertension. The existence of moderate to severe POPH has posed higher risk for orthotopic liver transplantation (OLT). New and evolving medical approaches may change the natural history of this disorder. Such approaches include administration of prostacyclins, endothelin receptor antagonists, and phosphodiesterase inhibitors. Administration may involve 24-hour continuous infusions, periodic inhaled, and oral routes. Liver transplantation in patients with moderate to severe POPH is problematic. Aside from patients being denied OLT specifically because of POPH, intraoperative death has occurred and unacceptable mortality during the transplant hospitalization has been reported. Finally, guidelines are evolving concerning which patients will benefit from the combination of evolving medical therapies and OLT. Whether the natural history of POPH can be dramatically changed remains an optimistic conjecture.

Down-regulation of the gax gene in smooth muscle cells of the splenic vein of portal hypertension patients

BACKGROUND

The expression of gax, an anti-proliferative homeobox gene, is rapidly down-regulated in vascular smooth muscle cells (VSMCs) following arterial injury. Whether the down-regulation of gax is involved in modulating the proliferation of smooth muscle cells of the splenic vein in patients with portal hypertension has not yet been elucidated. The aim of this study was to investigate the expression of the mRNA of the gax gene in smooth muscle cells of the splenic vein in patients with portal hypertension.

METHODS

Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the expression of gax mRNA and immunohistochemistry staining was performed to demonstrate the expression of PCNA protein in the splenic veins of 28 patients with portal hypertension and those of 12 normal controls. This study was approved by the Institutional Ethics Committee and informed consent was obtained from all participants.

RESULTS

RT-PCR showed that the expression of gax mRNA was PCNA-positive and negative in the splenic vein of patients with portal hypertension (1.08+/-0.04 and 1.39+/-0.27, respectively). There was a significant difference in the 28 patients compared with the 12 normal controls (P<0.01). The relative expression of PCNA protein in the vascular tissues was significantly higher in the experimental group than in the control group.

CONCLUSIONS

Down-regulation of gax mRNA and the overexpression of PCNA protein were seen in smooth muscle cells of the splenic vein in patients with portal hypertension, regulating the proliferation, migration and phenotypic change and resulting in remodelling of the splenic vein, which may play an important role in the pathogenesis and maintenance of portal hypertension.

Expression of cyclooxygenase in hyperdynamic portal hypertensive rats

BACKGROUND

By detecting hemodynamic changes, concentration of plasm prostacyclin (PGI2) and expression of cyclooxygenase (COX) in vasculature and splanchnic tissues, we evaluated the relative contributions of PGI2 and COX mRNA expression to the hyperdynamic circulatory state in chronic portal hypertensive rats.

METHODS

Fifty male Sprague-Dawley rats were divided into 3 groups: intrahepatic portal hypertension (IHPH, n=18) by injection of CCl4, prehepatic portal hypertension (PHPH, n=18) by partial stenosis of the portal vein, and sham-operated controls (SO, n=14). Splanchnic hemodynamics was measured by radioactive microsphere techniques and the concentration of PGI2 was detected by specific radioimmunoassay for its stable hydrolysis product 6-keto-PGF1alpha. Semi-quantitive reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to measure the levels of COX-1 mRNA and COX-2 mRNA in the thoracic aorta, superior mesenteric artery (SMA), and small intestine of IHPH, PHPH and SO rats, respectively.

RESULTS

Hyperdynamic circulatory state was characterized by increased splanchnic blood flow and decreased splanchnic vascular resistance in IHPH and PHPH rats. The concentration of plasma 6-keto-PGF1alpha (pg/ml) in IHPH (1093.75+/-142.15) and PHPH (897.42+/-53.29) rats was significantly higher than that in SO rats (730.13+/-98.67) (P<0.05). The expression of COX-1 mRNA in the thoracic aorta, SMA and small intestine was enhanced, whereas COX-2 mRNA expression was not detected in either of these vessels or the small intestine. The plasma 6-keto-PGF1alpha concentration and the expression of COX-1 mRNA in these vessels and the small intestine were closely correlated with such hemodynamic parameters as portal venous inflow (PVI), splanchnic vascular resistance (SVR) and free portal venous pressure (FPP) (P<0.05).

CONCLUSION

The expression of COX-1 mRNA and the levels of PGI2 were closely related to the hyperdynamic circulatory state of portal hypertensive rats.

[A study of the association of iNOS and eNOS gene polymorphism with portal hypertension in liver cirrhosis]

OBJECTIVE

To study whether polymorphism of iNOS and eNOS genes is associated with portal hypertension in liver cirrhosis.

METHODS

A case control study of 106 patients with liver cirrhosis due to HBV was performed in comparison with 108 controls using PCR-RFLP to detect iNOS promoter -969G --> C and eNOS exon7 894G --> T polymorphism.

RESULTS

The frequency of the C allele and GC genotype in the iNOS promoter -969G --> C was significantly higher in the portal hypertension group than in the control group. (P < 0.05). The frequency of the T allele and GT genotype in eNOS exon7 894G --> T was dramatically higher in the portal hypertension group than in the control group (P < 0.05). Multivariate logistic regression analysis revealed that iNOS polymorphism in iNOS promoter -969G --> C and eNOS exon7 894G --> T was an independent new risk factor for portal hypertension. We discovered that iNOS promoter -969G --> C led to an increase in its functional activity.

CONCLUSIONS

The polymorphism of iNOS promoter -969G --> C and eNOS exon7 894G --> T is associated with portal hypertension of liver cirrhosis, which is a new independent risk factor found related to the occurrence of portal hypertension. The polymorphism of iNOS promoter -969G --> C results in functional activity increase of the iNOS promoter.

CCR5-Delta32 mutation is strongly associated with primary sclerosing cholangitis

CCR5 plays a key role in the distribution of CD45RO+ T cells and contributes to generation of a T helper 1 immune response. CCR5-Delta32 is a 32-bp deletion associated with significant reduction in cell surface expression of the receptor. We investigated the role of CCR5-Delta32 on susceptibility to ulcerative colitis (UC), Crohn's disease (CD) and primary sclerosing cholangitis (PSC). Genotype and allelic association analyses were performed in 162 patients with UC, 131 with CD, 71 with PSC and 419 matched controls. There was a significant difference in CCR5 genotype (OR 2.27, P=0.003) between patients with sclerosing cholangitis and controls. Similarly, CCR5-Delta32 allele frequency was significantly higher in sclerosing cholangitis (17.6%) compared to controls (9.9%, OR 2.47, P=0.007) and inflammatory bowel disease patients without sclerosing cholangitis (11.3%, OR 1.9, P=0.027). There were no significant differences in CCR5 genotype or allele frequency between those with either UC or CD and controls. Genotypes with the CCR5-Delta32 variant were increased in patients with severe liver disease defined by portal hypertension and/or transplantation (45%) compared to those with mild liver disease (21%, OR 3.17, P=0.03). The CCR5-Delta32 mutation may influence disease susceptibility and severity in patients with PSC.

[Polymorphism of NOS2A promoter -969(G>C) is associated with portal hypertension of liver cirrhosis]

OBJECTIVE

To determine whether polymorphism of NOS2A promoter -969G>C is associated with the portal hypertension of liver cirrhosis.

METHODS

A case control study covering 106 patients with liver cirrhosis due to hepatitis B virus(HBV) in comparison with 108 controls was performed using PCR-restriction fragment length polymorphism. The NOS2A mRNA and protein expression in liver cirrhosis tissues were detected by reverse transcription-PCR and Western blot. The recombinant plasmids of NOS2A promoter luciferase reporter gene were constructed and were transfected transiently into HepG2 cells for analyzing the functional activity of the promoter.

RESULTS

The frequencies of the C allele and GC genotype at NOS2A promoter -969G>C were significantly higher in portal hypertension group (16.9%, 33.8%) than in control group(8.8%, 17.6%)(P<0.05), and positive correlation (r=0.18) and association (OR=2.42) were noted. There was no significant difference in frequency distribution between single liver cirrhosis group and control group(P>0.05). The expressions of NOS2A mRNA and protein in liver cirrhosis tissues were more increased in C allele carriers with liver cirrhosis than in G allele carriers with liver cirrhosis, which led to higher functional activity of the promoter. Multivariate logistic regression analysis revealed that NOS2A polymorphism at promoter -969G>C is an independent novel risk factor for the occurrence of portal hypertension in patients with liver cirrhosis.

CONCLUSION

The polymorphism of NOS2A promoter -969(G>C) is associated with portal hypertension of liver cirrhosis, which results in functional activity increase of NOS2A promoter and is an independent risk factor for portal hypertension.

[Relationship of endothelin-1 (ET-1) TaqI and tumor necrosis factor (TNF) a gene polymorphism with portal hypertension in liver cirrhosis]

OBJECTIVE

To study whether liver cirrhosis and portal hypertension are associated with ET-1 TaqI polymorphism and TNFa promoter-308G to A polymorphism.

METHODS

A case control study of 106 patients with liver cirrhosis following HBV C infection was performed in comparison with 108 controls by PCR-RFLP.

RESULTS

The frequency of C allele and CC+TC genotype in TaqI polymorphism of ET-1 gene in the portal hypertension group (LC+) was significantly higher than that in the healthy controls, and the frequency of TNF2/1 genotype in TNFa promoter -308 G to A polymorphism in LC+ group was significantly higher than that in the control group. The results by stratification analysis showed that TCF2 genotype frequency was higher in the LC+ group than in the control group. ET-1 TaqI polymorphism and TNFa polymorphism were risk factors for the occurrence of portal hypertension by Logistic regression analysis.

CONCLUSION

ET-1 TaqI polymorphism and TNFa polymorphism are associated with portal hypertension, and are new risk factors for the occurrence of portal hypertension. TCF2 genotype may be a susceptible gene of portal hypertension.

Nitric oxide synthase expression in the splanchnic hyposensitivity to glypressin of a hemorrhage-transfused rat model with portal hypertension

BACKGROUND

Nitric oxide (NO) has been proposed to participate in the vascular hyporesponsiveness to vasopressin and its long-acting analogue glypressin during hemorrhage in portal hypertensive states. This study surveyed the role of NO regarding splanchnic hyporeactivity to glypressin and NO synthases (NOS) expression in different vascular beds in bleeding portal-hypertensive rats.

METHODS

Under general anesthesia with ketamine, partially portal vein-ligated male Sprague-Dawley rats without or with bleeding were used to investigate the hemodynamic effects of glypressin (0.07 mg/kg intravenously) and constitutive (cNOS) and inducible NOS (iNOS) mRNA expression over the abdominal aorta and superior mesenteric artery.

RESULTS

Splanchnic hyposensitivity to glypressin was noted in the hemorrhage-transfused rats with enhanced cNOS expression of superior mesenteric artery. No significant differences of cNOS and iNOS expression in abdominal aorta and iNOS in superior mesenteric artery were found between the with-bleeding and without-bleeding groups.

CONCLUSIONS

In rats with portal hypertension and acute hemorrhage, cNOS over-expression in superior mesenteric artery may take a part in the splanchnic hyposensitivity to glypressin.

[The study on correlation of c-myc gene expression with vascular smooth muscle cell proliferation in patients with portal hypertension]

OBJECTIVE

To investigate c-myc proto-oncogene expression and the relationship of PCNA protein expression of extrahepatic vascular smooth muscle cell in patients with portal hypertension and normal vessels.

METHODS

RT-PCR was used to demonstrate the expression of c-myc mRNA and immuno-chemistry strain was performed to detect the expression of PCNA protein in splenic veins of 28 patients with portal hypertension and 12 normal vessels.

RESULTS

The straining of PCNA protein was (29.8 +/- 4.7)% in splenic veins with portal hypertension, Normal vessels did not detect PCNA protein expression (P < 0.01); RT-PCR showed that the expression of c-myc mRNA in PCNA-positive control and in negative control of splenic veins with portal hypertension were (7.61 +/- 1.04)% and (3.82 +/- 0.92)%, respectively. There ws different between two groups (P < 0.01) and significant different (P < 0.01) when compared with (1.01 +/- 0.21)% in normal vessels.

CONCLUSIONS

The c-myc was immediate-early gene when it modulated proliferation of vascular smooth muscle cell. Hemodynamic disturbance of portal vein system activate the proto-oncogene of smooth muscle cells in splenic vein of patients with portal hypertension, promoting the proliferation, migrating and phenotypic change and resulting in vascular remodelling of splenic veins.

[The association between polymorphism of endothelial nitric oxide synthase gene and cirrhotic portal hypertension]

OBJECTIVE

To study whether the liver cirrhosis and portal hypertension are associated with a -786T-->C mutation at promoter and VNTR polymorphism in intron 4 and a 894 G-->T mutation at exon 7 of the eNOS.

METHODS

A case control study of 106 patients with liver cirrhosis due to HBV was performed in comparison with 108 controls with the help of PCR-SSCP or RFLP.

RESULTS

There was no difference in the gene frequency of allele G of promoter between LC(+) group and other groups. The frequencies of the T and TG genotype at exon7 and the a allele and ab genotype in intron 4 were significantly higher in portal hypertension group (LC(+)) than in liver cirrhosis group alone and control group (P < 0.05). Patients of the liver cirrhosis with coexistence of the T and a alleles had a higher incidence of portal hypertension (P < 0.05) than those with only one of the two alleles or without any of the two alleles. Multivariate logistic regression analysis revealed that VNTR polymorphism in intron 4 and 894 G-->T mutation at exon 7 of the eNOS gene are independent risk factors for the occurrence of portal hypertension in patients with liver cirrhosis.

CONCLUSION

The T allele at exon 7 and a allele in intron 4 are associated with the occurrence of portal hypertension in patients with liver cirrhosis. The ocurrence of portal hypertension with liver cirrhosis is higher in patients who have both T and a allele than patients who have either T or a allele alone, which is an independent risk in occurrence of portal hypertension, respectively. TGab may be susceptibility genotype of portal hypertension.

Portal hypertension in Williams syndrome: report of two patients

Williams or Williams-Beuren syndrome (WBS) is a developmental disorder with multisystemic manifestations characterized by distinctive facial features, mental disability with unique cognitive and personality profiles, vascular stenoses, growth retardation, and occasional infantile hypercalcemia, caused by haploinsufficiency for genes deleted in chromosome band 7q11.23. However, with the exception of arterial stenoses caused by haploinsufficiency for the elastin gene (ELN), no specific implication of any other gene in the phenotype has been established. We present two patients with portal hypertension leading to splenomegaly and pancytopenia carrying the common 1.5 Mb WBS deletion. We propose this is an additional severe vascular complication of ELN deficiency and discuss the specific characteristics of the portal venous tract that could explain the impact of ELN deficiency in that venous territory. This complication is potentially lethal and should thus be considered in any patient with WBS and splenomegaly.

[Correlation between polymorphism of TaqI of ET-1 gene and cirrhotic portal hypertension]

OBJECTIVE

To investigate the correlation between polymorphism of TaqI of endothelin (ET)-1 gene intron 4 and cirrhotic portal hypertension and to search new risk factor of portal hypertension.

METHODS

Peripheral venous blood was extracted from 106 patients with cirrhosis after hepatitis B (PH+ group) and 108 healthy blood donors (PH- group). PCR-RFLP was used to analyze the polymorphism of TaqI of ET-1 gene. The plasma ET-1 concentration was detected with immunoassay. Multivariate logistic regression analysis was made to analyze the risk factors.

RESULTS

The C allele frequency in the PH+ group was 25.4%, significantly higher than that of the controls (16.7%, P < 0.05). The frequency of CC + TC genotype in PH+ group was 46.2%, significantly lower than that in the controls (29.6%, P < 0.05). In the PH+ group, the thickness of spleen was greater, hemorrhage rate was higher, and III degrees ascites was more in C allele carrier than in T allele carriers (P < 0.05). The plasma ET-1 concentration was higher in PH+ group than in PH- group. In the PH+ group, the plasma ET-1 concentrations in those with CC genotype and those with TC genotype were significantly higher than in those with TT genotype (P < 0.05). Correlation analysis showed that ET-1 gene polymorphism was positively correlated with plasma ET-1 concentration (R = 0.808 2). Multivariate logistic regression analysis showed that gradation of liver function, diameter of portal vein, and ET-1 gene polymorphism were independent risk factors of portal hypertension.

CONCLUSION

Polymorphism of TaqI of ET-1 gene is correlated with the pathogenesis of cirrhotic portal hypertension. It may be one of the risk factors of portal hypertension.

Idiopathic portal hypertension in a systemic sclerosis patient heterozygous for factor V Leiden mutation

Here we present a rare case of systemic sclerosis (SSc) with idiopathic portal hypertension (IPH) having factor V Leiden mutation, a well-known genetic risk factor for various venous thromboses. A 53-year-old SSc patient showing huge esophageal varices and splenomegaly without liver cirrhosis was diagnosed with IPH. As heterozygous Leiden mutation was detected, some coagulation abnormality and resultant formation of microthrombi in the branches of portal vein were suggested as a cause of IPH in this case. This is the first report showing the possible association between Leiden mutation and one of the complications of SSc.