Soluble guanylyl cyclase stimulation and phosphodiesterase-5 inhibition improve portal hypertension and reduce liver fibrosis in bile duct-ligated rats

BACKGROUND

In cirrhosis, the nitric oxide-soluble guanylyl cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway is impaired, which contributes to increased intrahepatic vascular resistance (IHVR) and fibrogenesis. We investigated if sGC stimulation (riociguat (RIO)), sGC activation (cinaciguat (CINA)) or phosphodiesterase (PDE)-5 inhibition (tadalafil (TADA)) improves portal hypertension (PHT) and liver fibrosis.

METHODS

Fifty male Sprague-Dawley rats underwent bile-duct ligation (BDL) or sham operation. RIO (0.5 mg/kg), CINA (1 mg/kg), TADA (1.5 mg/kg) or vehicle (VEH) was administered from weeks 2 to 4 after BDL. At week 4, invasive haemodynamic measurements were performed, and liver fibrosis was assessed by histology (chromotrope-aniline blue (CAB), Picro-Sirius red (PSR)) and hepatic hydroxyproline content.

RESULTS

Cirrhotic bile duct-ligated rats presented with PHT (13.1 ± 1.0 mmHg) and increased IHVR (4.9 ± 0.5 mmHg⋅min/mL). Both RIO (10.0 ± 0.7 mmHg, p = 0.021) and TADA (10.3 ± 0.9 mmHg, p = 0.050) decreased portal pressure by reducing IHVR (RIO: -41%, p = 0.005; TADA: -21%, p = 0.199) while not impacting heart rate, mean arterial pressure and portosystemic shunting. Hepatic cGMP levels increased upon RIO (+239%, p = 0.006) and TADA (+32%, p = 0.073) therapy. In contrast, CINA dosed at 1 mg/kg caused weight loss, arterial hypotension and hyperlactataemia in bile duct-ligated rats. Liver fibrosis area was significantly decreased by RIO (CAB: -48%, p = 0.011; PSR: -27%, p = 0.121) and TADA (CAB: -21%, p = 0.342; PSR: -52%, p = 0.013) compared to VEH-treated bile duct-ligated rats. Hepatic hydroxyproline content was reduced by RIO (from 503 ± 20 to 350 ± 30 µg/g, p = 0.003) and TADA (282 ± 50 µg/g, p = 0.003), in line with a reduction of the hepatic stellate cell activation markers smooth-muscle actin and phosphorylated moesin. Liver transaminases decreased under RIO (AST: -36%; ALT: -32%) and TADA (AST: -24%; ALT: -27%) treatment. Hepatic interleukin 6 gene expression was reduced in the RIO group (-56%, p = 0.053).

CONCLUSION

In a rodent model of biliary cirrhosis, the sGC stimulator RIO and the PDE-5 inhibitor TADA improved PHT. The decrease of sinusoidal vascular resistance was paralleled by a reduction in liver fibrosis and hepatic inflammation, while systemic haemodynamics were not affected.

Oxidative stress mediates an increased formation of vascular endothelial growth factor in human hepatocarcinoma cells exposed to erlotinib

The tyrosine kinase inhibitor erlotinib targets the receptor of epidermal growth factor (EGFR) involved in development of hepatocellular carcinoma (HCC).

Although inefficient in established HCC, erlotinib has been recently proposed for HCC chemoprevention. Since Cyp3A4 and Cyp1A2 enzymes metabolize erlotinib in the liver, the insights into the mechanisms of erlotinib effects on liver cells with maintained drug metabolizing activity are needed.

We applied erlotinib to both commercially available (SNU398, Huh7) and established in Austria HCC cell lines (HCC-1.2, HCC-3). Cyp3A4 and Cyp1A2, microarray gene expression, cell viability, LDH release, DHFC fluorescence were assessed. VEGF expression was analysed by real-time RT-PCR and ELISA.

Higher cumulative expression of erlotinib metabolizing enzymes was observed in HCC-1.2 and HCC-3 cells. Gene expression microarray analysis showed upregulation of VEGF signalling by erlotinib. VEGF was increased up to 134 ± 14% (n = 5, p = 0.002) in HCC-1.2, HCC-3 and Huh7 cells. Interventions by Cyp1A2 and Mek2siRNA, MEK inhibitor UO126, diphenylene iodonium, as well as a combination of N-acetylcysteine with selenium all inhibited VEGF upregulation caused by erlotinib.

Thus, erlotinib increases VEGF production by mechanisms involving Cyp1A2, oxidative stress and MEK1/2. VEGF may favour angiogenesis and growth of early HCC tumours limiting the therapeutic and chemopreventive effects of erlotinib.

Therapeutic outcome of 6198 interferon-naïve Egyptian patients with chronic hepatitis C: a real-life experience and lessons to be learned in DAAs' era

Antiviral therapy for HCV infection has been validated in randomized controlled clinical trials, but its value in the real world is less well studied. There is relatively little data on real-world responses to interferon-based therapies for patients with genotype 4 infection. We aimed to examine experience with large-scale access to antiviral therapy in chronic HCV in a real-life clinical setting in Egypt. Detailed pretreatment data of 6198 IFN-naïve chronic HCV patients who had received PEG-IFN/RBV therapy at Cairo-Fatemic Hospital, Egypt, between 2009 and 2012 were obtained from the HCV database. At week 12, 95.7% of patients had undetectable HCV RNA, and by week 24 and 48, breakthrough was 6% and 4%, respectively. However, 43.7% of patients discontinued treatment prematurely, and intent to treat end of treatment response was 44.6% (79.3% per protocol). Sustai-ned response data were available from only 1281 patients and was 84.9%. Haematological abnormalities were comparable in patients who did or did not comply with therapy. This is the first real-world, large-scale experience of antiviral therapy in chronic HCV in Egypt. Suboptimal response in HCV predominantly genotype 4 was mainly driven by noncompliance as well as gaps in the healthcare system leading to treatment discontinuation. These results need to be considered in the era of all oral antiviral regimes.

A phase II trial of low-dose estradiol in postmenopausal women with advanced breast cancer and acquired resistance to aromatase inhibition

BACKGROUND

High-dose oestrogen (HDE) is effective but toxic in postmenopausal women with advanced breast cancer (ABC). Prolonged oestrogen deprivation sensitises BC cell lines to estrogen and we hypothesised that third-generation aromatase inhibitors (AIs) would sensitise BCs to low-dose estradiol (LDE).

METHODS

A single-arm phase II study of LDE (2 mg estradiol valerate daily) in postmenopausal women with estrogen receptor-positive (ER+) ABC. The primary end-point was clinical benefit (CB) rate. If LDE was ineffective, HDE was offered. If LDE was effective, retreatment with the pre-LDE AI was offered on progression.

RESULTS

Twenty-one patients were recruited before the trial was closed early due to slow accrual; 19 were assessable for efficacy and toxicity. CB was seen in 5 in 19 patients (26%; 95% confidence interval 9.1-51.2%), all with prolonged SD (median duration 16.8 months; range 11.0-29.6). Treatment was discontinued for toxicity in 4 in 19 patients (21%) and 8 in 11 women without hysterectomy experienced vaginal bleeding (VB). After primary LDE failure, three patients received HDE and one achieved a partial response (PR). Following CB on LDE, four patients restarted pre-LDE AI and three achieved CB including one PR. Those with CB to LDE had a significantly longer duration of first-line endocrine therapy for ABC than those without (54.9 versus 16.8 months; p < 0.01) CONCLUSION: LDE is an effective endocrine option in women with evidence of prolonged sensitivity to AI therapy. LDE is reasonably well tolerated although VB is an issue. Re-challenge with the pre-LDE AI following progression confirms re-sensitisation as a true phenomenon.

Hysterosalpingo-contrast sonography (HyCoSy) using Echovist-200 in the outpatient investigation of infertility patients

This study describes the introduction of hysterosalpingo-contrast sonography (HyCoSy) as a first line outpatient investigation of uterine and tubal factors in two fertility units. 136 infertile women had transvaginal scanning before and during the intrauterine injection of contrast medium (Echovist-200). HyCoSy was successfully completed in 132 cases (97%) within a mean time of 12.6 +/- 8.4 (4-50) min. The uterus and its cavity appeared normal in 108 (82%) women. Uterine abnormalities in the remaining 24 women (18%) included structural abnormality (n = 7), fibroids (n = 12) and endometrial polyps (n = 5). A total of 261 fallopian tubes in 132 women were assessed: 186 (71%) appeared patent and 55 (21%) blocked. The remaining 20 (8%) could not be assessed for technical reasons. Polycystic ovaries and ovarian cysts were diagnosed in eight women. The most common adverse effect was mild/moderate pain, similar to period pain, with 24 (18%) women requiring simple analgesia. HyCoSy is a simple and well tolerated outpatient procedure. The technique provides clinically valuable information about tubal patency, ovarian and uterine abnormalities.

Gingival matrix collagen in chronic periodontitis

The isolation and characterization of cyanogen bromide peptides derived from the human gingival collagen of patients with chronic periodontitis revealed the presence of both Type I and Type III collagens in this tissue. The amount of TYPE III collagen, however, was found to be lower than that in normal gingival tissue. In addition, a non-collagenous protein fraction, accounting for approximately 20% of the insoluble matrix, was relatively rich in acidic, hydrophobic, and hydroxy-containing amino acids. Amino acid analysis, likewise, revealed qualitative and quantitative differences between the normal and diseased tissues.