Investigation of liver fibrosis in clinical practice

Ultrasonographic Assessment of Tissue Stiffness: Recent Progress in Transient Elastography and Shear Wave Elastography in the Liver and Various Organs

Ultrasonography is a noninvasive and widely accessible modality in clinical practice. Recently, ultrasonography has been used to evaluate tissue stiffness; the two representative techniques are transient elastography (FibroScan®) and shear wave elastography. These modalities are now generally used for the assessment of liver fibrosis, the prediction of hepatocarcinogenesis, and determining prognosis. In addition, shear wave elastography is available, not only for the liver but also for various other organs, including the breast and brain. In the breast and brain, shear wave elastography distinguishes malignant lesions from benign ones. Moreover, shear wave elastography can be useful for differentiating between ischemic and hemorrhagic strokes. This review summarizes the recent progress in transient elastography and shear wave elastography of the liver and introduces the advantages of ultrasonographic assessment of tissue stiffness in various organs, including the breast, brain, kidney, heart, thyroid, pancreas, muscle, and bone.

Non-Invasive Measurement of Hepatic Fibrosis by Transient Elastography: A Narrative Review

Transient elastography by FibroScan® (Echosens, Paris, France) is a non-invasive method that can provide a reliable measurement of liver fibrosis through the evaluation of liver stiffness. Despite its limitations and risks, liver biopsy has thus far been the only procedure able to provide data to quantify fibrosis. Scientific evidence and clinical practice have made it possible to use FibroScan® in the diagnostic work-up of several liver diseases to monitor patients' long-term treatment response and for complication prevention. For these reasons, this procedure is widely used in clinical practice and is still being investigated for further applications. The aim of this narrative review is to provide a comprehensive overview of the main applications of transient elastography in the current clinical practice.

Liver Stiffness Measured by Either Magnetic Resonance or Transient Elastography Is Associated With Liver Fibrosis and Is an Independent Predictor of Outcomes Among Patients With Primary Biliary Cholangitis

GOALS

We aimed to describe the diagnostic and prognostic performance of transient elastography (TE) and magnetic resonance elastography (MRE) in patients with primary biliary cholangitis (PBC).

BACKGROUND

The diagnostic performance of TE and MRE in detecting advanced fibrosis in PBC and in predicting outcomes independent of existing serologic prognostic markers is incompletely understood.

MATERIALS AND METHODS

Five hundred thirty-eight consecutive patients with PBC at 3 centers with liver stiffness (LS) measurements by TE (n=286) or MRE (n=332) were reviewed. LS cutoffs for predicting fibrosis stages were determined by receiver operating characteristic curves among those with a liver biopsy (TE, n=63; MRE, n=98). Cox proportional hazard regression modeling was used to identify associations between covariates and hepatic decompensation.

RESULTS

The optimal LS thresholds for predicting histologic stage F4 were 14.40 kPa (area under the curve=0.94) for TE and 4.60 kPa (area under the curve=0.82) for MRE. Both TE and MRE outperformed biochemical markers for the prediction of histologic advanced fibrosis. Optimal LS thresholds to predict hepatic decompensation were 10.20 kPa on TE and 4.30 kPa on MRE. LS by TE and MRE (respectively) remained predictors of hepatic decompensation after adjusting for ursodeoxycholic acid responsiveness [hazard ratio (HR), 1.14; 95% confidence interval (CI), 1.05-1.24 and HR, 1.68; 95% CI, 1.28-2.19] and the GLOBE score (HR, 1.13; 95% CI, 1.07-1.19 and HR, 2.09; 95% CI, 1.57-2.78).

CONCLUSION

LS measurement with either TE or MRE can accurately detect advanced fibrosis and offers additional prognostic value beyond existing serologic predictive tools.

Comparison of liver stiffness assessment by transient elastography and shear wave elastography using six ultrasound devices

AIM

Transient elastography (TE) is the gold standard for measurement of liver stiffness. The usefulness of shear wave elastographies (SWE) is well accepted. However, the measurement values cannot be equivalently compared because cut-off values for the diagnosis of liver fibrosis are different among those devices. We aimed to clarify correlations, to generate the regression equations between TE and SWEs, and to compare the diagnostic ability of each device to diagnose liver fibrosis.

METHODS

A total of 109 patients with chronic liver disease who underwent liver biopsy and same-day evaluation of liver stiffness using six ultrasound devices were analyzed. The diagnostic ability of liver stiffness from each ultrasound device and correlations between TE and each SWE were analyzed.

RESULTS

Liver stiffness measured by all six ultrasound devices increased significantly as liver fibrosis stage advanced (P < 0.001). Receiver operating characteristic (ROC) curve analysis for predicting significant fibrosis (≥F2) and cirrhosis yielded area under the ROC curve (AUROC) values based on TE of 0.830 (95% confidence interval [CI], 0.755-0.905) and 0.959 (95% CI, 0.924-0.995), respectively. The AUROCs for predicting significant fibrosis (≥F2) and cirrhosis (F4) based on SWE from all five ultrasound devices were over 0.8 and 0.9, respectively. Furthermore, the correlation coefficients between TE values and SWE values from five ultrasound devices were all over 0.8, indicating a strong relationship.

CONCLUSION

Our study showed strong correlations between TE and SWEs with high correlation coefficients. The regression equations between TE and SWEs demonstrated the ability to compare the measurement values in each device equivalently.

Real-Time Elastography: Noninvasive Diagnostic Tool in the Evaluation of Liver Stiffness in Patients with Chronic Viral Hepatitis, Correlation with Histological Examination

PURPOSE

To determine the value of real-time elastography (RTE) in the assessment of liver stiffness in patients with chronic viral hepatitis, correlating RTE data with the extent of fibrosis based on biopsy findings (Ishak score).

METHODS

We evaluated 98 patients (45-75 years) with chronic viral hepatitis (51 HCV, 47 HBV) by using ultrasonography (US) study combined with RTE analysis. In the RTE images, relative tissue stiffness is expressed, according to color scale, with soft areas represented in green/red colors and hard areas in blue. We divided the patients into 2 groups based on the fibrosis degree: soft degree (D1, corresponding to F1-F3 Ishak score) and hard degree (D2, corresponding to F4-F6). Before RTE, all patients underwent a US-guided percutaneous liver biopsy (right lobe).

RESULTS

Quantitative RTE data were compared with liver biopsy by using the Spearman correlation coefficient in order to assess the correlation between the RTE (D) and fibrosis, according to Ishak score (F) at histology. At RTE, out of 98 patients 55 had degree D1 and 43 had degree D2; at histological analysis, we observed the following: 15 patients with F1, 28 with F2, 17 with F3, 16 with F4, 12 with F5, and 10 with F6. The Spearman's coefficient showed significant correlation between D and F degree, obtaining rho = 0.573, p = 0.003.

CONCLUSIONS

RTE analysis showed high diagnostic accuracy in the assessment of fibrosis, and it appears to be a useful diagnostic tool for noninvasive quantification of fibrosis in patients with chronic viral hepatitis.

Contrast-enhanced ultrasound and computerized tomography perfusion imaging of a liver fibrosis-early cirrhosis in dogs

BACKGROUND AND AIM

To assess liver fibrosis stages in a liver fibrosis-early cirrhosis model in dogs, the clinical efficiency of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) perfusion imaging were compared.

METHODS

Hepatic vein arriving time (HVAT), hepatic artery arriving time, and hepatic artery to vein transit time (HA-VTT) were measured on CEUS. Total liver perfusion (TLP), portal vein perfusion (PVP), hepatic artery perfusion, and hepatic perfusion index (HPI) were measured on CT perfusion imaging. Histologic examination of liver specimens of the animals was performed to assess the fibrosis stage.

RESULTS

For assessment of liver fibrosis, the area under the receiver operating characteristic curve of CEUS indexes HVAT and HA-VTT were 0.865 and 0.930, respectively; the perfusion CT indexes TLP, PVP, and HPI were 0.797, 0.800, and 0.220, respectively; the serological index hyaluronic acid was 0.793. While for assessment of early cirrhosis, the area under the receiver operating characteristic curve of CEUS indexes HVAT and HA-VTT were 0.915 and 0.948, respectively; the perfusion CT indexes TLP, PVP, and HPI were 0.737, 0.765, and 0.218, respectively; the serological index hyaluronic acid was 0.627.

CONCLUSIONS

This study showed that both CEUS and CT perfusion imaging have the potential to be complementary imaging tools in the evaluation of liver fibrosis. While CEUS is the better choice and the index HA-VTT can be considered as non-invasive semi-quantitative indexes for diagnosing liver fibrosis and early cirrhosis.

Human liver myofibroblasts during development and diseases with a focus on portal (myo)fibroblasts

Myofibroblasts are stromal cells mainly involved in tissue repair. These cells present contractile properties and play a major role in extracellular matrix deposition and remodeling. In liver, myofibroblasts are found in two critical situations. First, during fetal liver development, especially in portal tracts, myofibroblasts surround vessels and bile ducts during their maturation. After complete development of the liver, myofibroblasts disappear and are replaced in portal tracts by portal fibroblasts. Second, during liver injury, myofibroblasts re-appear principally deriving from the activation of local stromal cells such as portal fibroblasts and hepatic stellate cells or can sometimes emerge by an epithelial-mesenchymal transition process. After acute injury, myofibroblasts play also a major role during liver regeneration. While myofibroblastic precursor cells are well known, the spectrum of activation and the fate of myofibroblasts during disease evolution are not fully understood. Some data are in accordance with a possible deactivation, at least partial, or a disappearance by apoptosis. Despite these shadows, liver is definitively a pertinent model showing that myofibroblasts are pivotal cells for extracellular matrix control during morphogenesis, repair and fibrous scarring.

Diagnostic value of real-time elastography in the assessment of hepatic fibrosis in patients with liver iron overload

OBJECTIVE

The objective of our prospective monocentric work was to determine the diagnostic value of real-time elastography (RTE) in the assessment of liver fibrosis in patients with iron overload, using transient elastography (TE) as reference standard.

METHODS

Sixty-seven consecutive patients with MRI detectable iron overload (T2*<6.3 ms) were enrolled. TE and RTE were performed on the same day as MRI. Elastograms were acquired by an experienced operator and analyzed by calculating the elastic ratio between perihepatic soft tissues and liver parenchyma. An elliptical ROI of 1cm(2) (Z1) was positioned in the liver parenchyma and a smaller elliptical ROI of 2mm(2) (Z2) was positioned in a homogeneously soft (red) region of the diaphragm, which was considered as internal control to calculate the elastic ratio Z2/Z1.

RESULTS

Seven patients were excluded because of invalid TE or RTE examinations. The remaining 60 patients were 57% males and 43% females (mean age: 42 [21-76] years), including 37 homozygous-β-thalassemics, 13 patients with β-thalassemia intermedia, 6 with primary hemochromatosis, and 4 with myelodysplastic syndrome. Increasing elastic ratios were significantly correlated with increasing TE values (r=0.645, 95% CI 0.468-0.772, P<0.0001). The mean elastic ratios for each METAVIR group were as follows: F0/1 = 1.9 ± 0.4; F2 = 2.2 ± 0.4; F3 = 2.9 ± 0.5; F4 = 3.2 ± 0.4. The diagnostic accuracy of RTE for F ≥ 2 evaluated by AUC-ROC analysis was 0.798 (95% CI 0.674-0.890). The diagnostic accuracy of RTE for F ≥ 3 was 0.909 (95% CI 0.806-0.968). At a cut-off ≥ 2.75, RTE showed a sensitivity of 70% (95% CI 45.7-88.1) and a specificity of 97.5% (95% CI 86.8-99.9).

CONCLUSIONS

In patients with MRI-detectable liver iron-overload RTE allows to discriminate between F0/1-F2 and F3-F4 with a reasonable diagnostic accuracy.

Comparative diagnostic study of biomarkers using FibroMax™ and pathology for prediction of liver steatosis in patients with chronic hepatitis C virus infection: an Egyptian study

BACKGROUND

Steatosis is common in patients with hepatitis C virus (HCV) infection and may be a major determinant of progression of liver injury. This study evaluated FibroMax™ for noninvasive diagnosis of steatosis in patients with chronic HCV.

METHODS

This cross-sectional study included 44 patients naïve to treatment who were referred to our hepatology clinic for assessment of fitness for antiviral therapy. Chronic HCV infection was diagnosed by viral markers. Investigations included assessment of abdominal ultrasonography, liver biopsy, calculation of body mass index, and biomarker parameters in serum using FibroMax.

RESULTS

Histopathology of liver biopsies showed steatosis in 30 of 44 (68%) patients. FibroMax results were positively correlated with viral load by quantitative polymerase chain reaction and histopathological findings. Body mass index was significantly higher in steatotic patients (P = 0.003) and was significantly associated with the results on FibroMax (P = 0.005).

CONCLUSION

FibroMax was correlated with histopathology and body mass index in patients with HCV. Abdominal ultrasonography could not be used as a single tool to diagnose steatosis with HCV. Steatosis is correlated with viral load, which suggests a direct viral effect. We recommend FibroMax assessment in a larger number of patients to assess its applicability in patients with HCV and steatosis.

Is ultrasound elastography of the liver ready to replace biopsy? A critical review of the current techniques

Accurate assessment of liver fibrosis in patients with chronic liver disease is necessary to determine prognosis, monitor disease progression and formulate treatment decisions. Currently, histological staging of liver biopsy is the most widely used reference standard for this purpose. Liver biopsy, however, has recognized risks, as well as sampling and observer error. These limitations have stimulated the search for new non-invasive approaches. Numerous methodologies, including serum markers, magnetic resonance elastography and ultrasound elastography, have evolved in the last decade to predict fibrosis in those with chronic liver disease. Ultrasound elastography methods assess liver fibrosis by determining liver stiffness and translate this into a quantifiable measurement for analysis. As these tests are non-invasive, without side-effect or discomfort, it is possible to conduct repeat examinations at much closer intervals than biopsy. The three most investigated ultrasound elastography methods are transient elastography, realtime elastography and acoustic radiation force impulse. Although significant strides have been made in the development of the technology, an unequivocal advocacy of elastography as a surrogate for biopsy is still not established. The aim of this review is to evaluate the advantages, limitations and clinical relevance of the three ultrasound-based modalities. Also, the review shall assess the current and possible future clinical application the modalities may serve both separate and in conjunction with liver biopsy.

Does hepatic vein transit time performed with contrast-enhanced ultrasound predict the severity of hepatic fibrosis?

Previously published data suggest a hepatic vein transit time (HVTT) threshold of more than 24 s can distinguish mild to moderate from advanced fibrosis. In this study, we attempted to validate HVTT as a noninvasive index of hepatic fibrosis. Patients were scanned using real-time, pulse-inversion mode following bolus injections of the contrast agent Definity. HVTT was correlated with the degree of fibrosis obtained from contemporaneous liver biopsy. The study population included 40 patients with chronic liver disease and five healthy volunteers. Mean HVTT correlated with histologic grade as follows: absence/minimal fibrosis (n = 18), 25.6 ± 11.8 s; moderate fibrosis (n = 17), 21.5 ± 5.9 s; and severe fibrosis (n = 8), 20.9 ± 5.5 s, (p = .615). Poor sensitivity (57%) and specificity (43%) prevent validation of the previously published HVTT threshold as a surrogate marker of hepatic fibrosis. Further work investigating the different interaction of Definity, SonoVue and Levovist with the reticulo-endothelial system may help explain the discrepant results reported here.

The role of the non-invasive serum marker FibroTest-ActiTest in the prediction of histological stage of fibrosis and activity in children with naïve chronic hepatitis B infection

The aim of this study was to investigate whether the non-invasive serum marker FibroTest-ActiTest (FT-AT) reliably predicts the histological stage of fibrosis and/or activity, and decreases the need for a liver biopsy. Twenty-five children with naïve chronic hepatitis B were analyzed for haptoglobin, alpha2-macroglobulin, apolipoprotein A1, bilirubin, gamma-glutamyl transferase, and alanine aminotransferase activity, and the FT-AT scores were computed. FT-AT scores were compared with histological data. FT predicted insignificant fibrosis in 14/23 (61%) patients at a cut-off level of 0.31. Nine patients (36%) had significant histological fibrosis, but none were predicted by FT. There was no correlation between FT scores and histological stage of fibrosis (r: -0.221, p = 0.228). All 4 patients with significant histological activity had corresponding significant activity in AT (100%). Fifteen out of the 19 patients (78.9%) with significant activity in AT had insignificant histological activity. At the cut-off level of 0.36, AT predicted insignificant activity in all 6 patients (100%). There was no correlation between AT scores and histological activity (r: 0.245, p = 0.237). According to histological data, 12 patients were candidates for treatment, but FT-AT did not predict 3 of them (25%). FT-AT does not appear ready for use in detecting either the stage of fibrosis or activity in children with chronic hepatitis B.

Transient elastography for liver fibrosis diagnosis

Liver biopsy is considered the "golden standard" for assessment of hepatic fibrosis. However, the procedure has limitations because of inconvenience and rare but serious complications as bleeding. Furthermore, sampling errors are frequent, and interobserver variability often poses problems. Recently, a modified ultrasound scanner (transient elastography) has been developed to assess fibrosis. The device measures liver elasticity, which correlates well with the degree of fibrosis. Studies have shown that transient elastography is more accurate in diagnosing cirrhosis than minor to moderate fibrosis. Most of the studies have been conducted on patients with chronic hepatitis but a few studies have also covered fibrosis and cirrhosis due to other etiologies, and they also demonstrate the high sensitivity and specificity. Transient elastography for assessment of fibrosis may turn out to be a valuable diagnostic procedure and follow-up of patients with chronic liver diseases.

Liver fibrosis staging with contrast-enhanced ultrasonography: prospective multicenter study compared with METAVIR scoring

We prospectively assessed contrast-enhanced sonography for evaluating the degree of liver fibrosis as diagnosed via biopsy in 99 patients. The transit time of microbubbles between the portal and hepatic veins was calculated from the difference between the arrival time of the microbubbles in each vein. Liver biopsy was obtained for each patient within 6 months of the contrast-enhanced sonography. Histological fibrosis was categorized into two classes: (1) no or moderate fibrosis (F0, F1, and F2 according to the METAVIR staging) or (2) severe fibrosis (F3 and F4). At a cutoff of 13 s for the transit time, the diagnosis of severe fibrosis was made with a specificity of 78.57%, a sensitivity of 78.95%, a positive predictive value of 78.33%, a negative predictive value of 83.33%, and a performance accuracy of 78.79%. Therefore, contrast-enhanced ultrasound can help with differentiation between moderate and severe fibrosis.

Thy-1 is expressed in myofibroblasts but not found in hepatic stellate cells following liver injury

Thy-1 (CD90) is an adhesion molecule induced in fibroblast populations associated with wound healing and fibrosis. In this study the question whether Thy-1-gene-expression can be induced in hepatic stellate cells (HSC) in vivo, under conditions of liver injury or liver regeneration was addressed. Acute and chronic rat liver injury was induced by the administration of CCl4. For comparison, cirrhotic human liver, and rat 67% partial hepatectomy (PH) was studied as well. Thy-1-gene-expression was examined also in isolated human liver myofibroblasts. Thy-1-mRNA expression was significantly upregulated in chronic liver injury. Thy-1+ cells were detected in the periportal area of rat liver specimens in normal-, injured- and regenerative-conditions. In chronic human and rat liver injury, Thy-1+ cells were located predominantly in scar tissue. In the pericentral necrotic zone after CCl4-treatment, no induction of Thy-1 was found. Gremlin and Thy-1 showed comparable localization in the periportal areas. Thy-1 was not detected in either normal or capillarized sinusoids, in isolated rat HSC, and was neither inducible by inflammatory cytokines in isolated HSC, nor upregulated in treated myofibroblasts. Based upon these data Thy-1 is not a marker of "activated" sinusoidal HSC, but it is a marker of "activated" (myo)fibroblasts found in portal areas and in scar tissue.

Performance of transient elastography for the staging of liver fibrosis: a meta-analysis

BACKGROUND & AIMS

Transient elastography has been studied in a multitude of liver diseases for the staging of liver fibrosis with variable results. A meta-analysis was performed to assess the overall performance of transient elastography for the diagnosis of liver fibrosis and to analyze factors influencing the diagnostic accuracy.

METHODS

Literature databases and international conference abstracts were searched. Inclusion criteria were as follows: evaluation of transient elastography, liver biopsy as reference, and assessment of the area under the receiver operating characteristic curve (AUROC). The meta-analysis was performed using the random-effects model for the AUROC, summary receiver operating curve techniques, as well as meta-regression approaches.

RESULTS

Fifty studies were included in the analysis. The mean AUROC for the diagnosis of significant fibrosis, severe fibrosis, and cirrhosis were 0.84 (95% confidence interval [CI], 0.82-0.86), 0.89 (95% CI, 0.88-0.91), and 0.94 (95% CI, 0.93-0.95), respectively. For the diagnosis of significant fibrosis a significant reduction of heterogeneity of the AUROC was found when differentiating between the underlying liver diseases (P < .001). Other factors influencing the AUROC were the scoring system used and the country in which the study was performed. Age, body mass index, and biopsy quality did not have a significant effect on the AUROC.

CONCLUSIONS

Transient elastography can be performed with excellent diagnostic accuracy and independent of the underlying liver disease for the diagnosis of cirrhosis. However, for the diagnosis of significant fibrosis, a high variation of the AUROC was found that is dependent on the underlying liver disease.

Transient elastography to assess hepatic fibrosis in primary biliary cirrhosis

BACKGROUND

Liver stiffness measurements may have potential for detecting and monitoring hepatic fibrosis in chronic liver disease.

AIM

To study the detection, quantification and progression of hepatic fibrosis in primary biliary cirrhosis by liver stiffness measurements.

METHODS

Liver stiffness measurements were generated in 80 patients with primary biliary cirrhosis by applying transient elastography; however, as there were 55 with liver biopsy, histological stage (METAVIR) and liver stiffness measurements were compared only in these 55 patients. The efficiency of liver stiffness measurements in predicting stage of fibrosis was determined from the area under receiver operating characteristics curve analysis.

RESULTS

Of the 80 patients included, 91, 4% were women and their mean age was 56 +/- 12 (s.d.) years. A significant correlation was found (P < 0.05) between histological fibrosis stage (METAVIR) and liver stiffness measurements. The values obtained from area under receiver operating characteristic curve analysis of liver stiffness measurement data were 0.89 for F > 2 and 0.96 for F = 4. Liver stiffness measurements were 9.0 +/- 5.3 and 7.9 +/- 6.0 kPa for patients followed up more than 5 years and less than 5 years, respectively (P > 0.05).

CONCLUSIONS

In patients with primary biliary cirrhosis, median values of liver stiffness measurements correlated with histological severity of hepatic fibrosis. Liver stiffness measurements appear to be promising for liver fibrosis detection and quantification, as well as monitoring its progression, in patients with primary biliary cirrhosis. The progression rate of hepatic fibrosis in our primary biliary cirrhosis patients appears to be slow.

Biochemical and biophysical assessment of MTX-induced liver fibrosis in psoriasis patients: Fibrotest predicts the presence and Fibroscan predicts the absence of significant liver fibrosis

BACKGROUND

Methotrexate (MTX) use is associated with hepatic fibrosis in psoriasis patients. To monitor this serial liver biopsies were performed. The Fibroscan and the Fibrotest are two novel, non-invasive methods that might be able to assess MTX-induced hepatic fibrosis.

AIM

Evaluating the accuracy and feasibility of the Fibroscan and Fibrotest to detect significant MTX-induced liver fibrosis in psoriasis patients.

METHODS

We assessed 24 psoriasis patients who had a recent liver biopsy during MTX use. The results from the Fibroscan and Fibrotest were compared with liver histology.

RESULTS

Fibroscan values (n=20) ranged between 3.3 and 18.4 kPa (median value 6.4 kPa) and correctly identified 88% of the patients without significant liver fibrosis (Metavir score <F2, Fibroscan</=7.1 kPa). The Fibrotest identified 83% of the patients with significant liver fibrosis (Metavir score >/=F2, Fibrotest >0.31).

CONCLUSION

In this population, Fibrotest accurately predicted the presence of significant liver fibrosis while the Fibroscan accurately predicted the absence of significant liver fibrosis in MTX users. This suggests that a combination of Fibrotest and Fibroscan should prospectively be evaluated in monitoring and detecting significant MTX-induced liver fibrosis in psoriasis patients.

Arg-gly-asp-mannose-6-phosphate inhibits activation and proliferation of hepatic stellate cells in vitro

AIM: To investigate the effect of arg-gly-asp-mannose-6 phosphate (RGD-M6P) on the activation and proliferation of primary hepatic stellate cells in vitro.

METHODS: Hepatic stellate cells (HSCs) were isolated from rats by in situ collagenase perfusion of liver and 18% Nycodenz gradient centrifugation and cultured on uncoated plastic plates for 24 h with DMEM containing 10% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, HSCs were cultured in 2% FBS/DMEM with transforming growth factor β1, M6P, RGD, or RGD-M6P, respectively. Cell morphology was observed under inverted microscope, smooth muscle α-actin (α-SMA) was detected by immunocytochemistry, type III procollagen (PCIII) in supernatant was determined by radioimmunoassay, and the proliferation rate of HSCs was assessed by flow cytometry.

RESULTS: RGD-M6P significantly inhibited the morphological transformation and the α-SMA and PCIII expressions of HSCs in vitro and also dramatically prevented the proliferation of HSCs in vitro. Such effects were remarkably different from those of RGD or M6P.

CONCLUSION: The new compound, RGD-M6P, which has a dramatic effect on primary cultured HSCs in vitro, can inhibit the transformation of HSCs in culture caused by TGFβ1, suppresses the expression of PCIII and decreases proliferation rate of HSC. RGD-M6P can be applied as a selective drug carrier targeting at HSCs, which may be a new approach to the prevention and treatment of liver fibrosis.