Experimental study of the effects of deletion variant of hepatocyte growth factor on hepatic ischaemia-reperfusion injury

Deceleration of regenerative response improves the outcome of rat with massive hepatectomy

Small residual liver volume after massive hepatectomy or partial liver transplantation is a major cause of subsequent liver dysfunction. We hypothesize that the abrupt regenerative response of small remnant liver is responsible for subsequent deleterious outcome. To slow down the regenerative speed, NS-398 (ERK1/2 inhibitor) or PD98059 (selective MEK inhibitor) was administered after 70% or 90% partial hepatectomy (PH). The effects of regenerative speed on liver morphology, portal pressure and survival were assessed. In the 70% PH model, NS-398 treatment suppressed the abrupt replicative response of hepatocytes during the early phase of regeneration, although liver volume on day 7 was not significantly different from that of the control group. Immunohistochemical analysis for CD31 (for sinusoids) and AGp110 (for bile canaliculi) revealed that lobular architectural disturbance was alleviated by NS-398 treatment. In the 90% PH model, administration of NS-398 or PD98059, but not hepatocyte growth factor, significantly enhanced survival. The abrupt regenerative response of small remnant liver is suggested to be responsible for intensive lobular derangement and subsequent liver dysfunction. The suppression of MEK/ERK signaling pathway during the early phase after hepatectomy makes the regenerative response linear, and improves the prognosis for animals bearing a small remnant liver.

Hepatocyte growth factor pretreatment reduces apoptosis and mucosal damage after intestinal ischemia-reperfusion

BACKGROUND/PURPOSE

Ischemia-reperfusion (IR) injury to the intestine can result in mucosal damage and cellular death. This study was designed to evaluate the protective effects of pretreatment with hepatocyte growth factor (HGF) on intestine after moderate IR injury.

METHODS

Control animals (n = 7) received 48 hours of intravenous saline, and treatment animals (n = 7) received HGF (150 microg/kg/d). After 35 minutes of mesenteric artery occlusion and 120 minutes of reperfusion, serum and jejunal mucosa samples were obtained. Fluorometric assays were performed for hexosaminidase A (HEX A) and beta-glucuronidase (GLUC), enzyme markers of enterocyte necrosis. Apoptosis was quantified by the TUNEL method. Transcription of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) was assessed by multiplex reverse transcription polymerase chain reaction (RT-PCR) Statistical analysis was performed using the Student's t test.

RESULTS

After HGF pretreatment, HEX A and GLUC activities were reduced from 543 +/- 28 to 343 +/- 35 nmole/h/mL (P <.01) and 183 +/- 29 to 119 +/- 22 nmole/h/mL (P <.01), respectively. Pretreated animals had a reduced number of apoptotic cells per 10 crypts (33 +/- 11) compared with untreated rats (225 +/- 24) after IR injury (P <.01). Mean IFN-gamma band intensity was lower in HGF-pretreated animals (0.05 +/- 0.02) compared with controls (0.31 +/- 0.09; P <.05).

CONCLUSIONS

Pretreatment with HGF reduces the severe crypt apoptosis and cellular necrosis after IR injury to the intestine. These data suggest that HGF may be beneficial in attenuating IR damage and thus may have significant clinical application.

Pharmacokinetics and biochemical effects of hepapoietin in patients with chronic liver disease

BACKGROUND

Hepapoietin is a naturally occurring cytokine that promotes hepatocyte growth. Animal studies have suggested that hepapoietin and hepatocyte growth factor have a potential role in the prevention and management of liver diseases. However, human studies have been lacking.

AIM

To evaluate the safety and pharmacokinetics of single escalating doses of hepapoietin in patients with chronic liver disease.

METHODS

An open-label, single escalating dose trial with five different doses of hepapoietin (1, 3, 10, 30 and 100 mg) was performed. Adults with chronic, compensated, non-viral liver disease were included. Liver function tests were obtained before dosing, 24 h after hepapoietin administration and on days 4, 7, 30 and 45. All patients were followed for 45 days.

RESULTS

Twenty-five subjects received hepapoietin, with five subjects each at 1, 3, 10, 30 and 100 mg of hepapoietin. Significant decreases occurred in total bilirubin, ammonia, partial thromboplastin time and cholesterol levels overall, and both high-density and low-density lipoprotein cholesterol showed a downward trend. An increase in albumin was observed at the 30 mg dose level. Slight decreases in haemoglobin and red blood cell levels were observed at day 4, but returned to normal levels immediately thereafter. Child-Pugh scores from day 0 to day 7 were improved in 24%, stable in 64% and worse in 12% of patients. Hepatic encephalopathy displayed changes from day 0 to day 45 with improvement in 16%, no change in 80% and worsening in 4%.

CONCLUSIONS

Hepapoietin in doses up to 100 mg is safe for use in humans. Potential benefits are suggested by significant decreases in bilirubin, ammonia, partial thromboplastin time and cholesterol levels and an increase in albumin. Further studies with multiple dosing regimens are needed to identify the clinical utility of hepapoietin in the management of chronic liver disease.