Quantitative Assessment of Hepatic Steatosis Using Label-Free Multiphoton Imaging and Customized Image Processing Program.

Nonalcoholic fatty liver disease is rapidly becoming one of the most common causes of chronic liver disease worldwide and is the leading cause of liver-related morbidity and mortality. A quantitative assessment of the degree of steatosis would be more advantageous for diagnostic evaluation and exploring the patterns of disease progression. Here, multiphoton microscopy, based on the second harmonic generation and 2-photon excited fluorescence, was used to label-free image the samples of nonalcoholic fatty liver. Imaging results confirm that multiphoton microscopy is capable of directly visualizing important pathologic features such as normal hepatocytes, hepatic steatosis, Mallory bodies, necrosis, inflammation, collagen deposition, microvessel, and so on and is a reliable auxiliary tool for the diagnosis of nonalcoholic fatty liver disease. Furthermore, we developed an image segmentation algorithm to simultaneously assess hepatic steatosis and fibrotic changes, and quantitative results reveal that there is a correlation between the degree of steatosis and collagen content. We also developed a feature extraction program to precisely display the spatial distribution of hepatocyte steatosis in tissues. These studies may be beneficial for a better clinical understanding of the process of steatosis as well as for exploring possible therapeutic targets.

Detection of fibrotic changes in the progression of liver diseases by label-free multiphoton imaging.

Collagen fibers play an important role in the progression of liver diseases. The formation and progression of liver fibrosis is a dynamic pathological process accompanied by morphological changes in collagen fibers. In this study, we used multiphoton microscopy for label-free imaging of liver tissues, allowing direct detection of various components including collagen fibers, tumors, blood vessels, and lymphocytes. Then, we developed a deep learning classification model to automatically identify tumor regions, and the accuracy reaches 0.998. We introduced an automated image processing method to extract eight collagen morphological features from various stages of liver diseases. Statistical analysis showed significant differences between them, indicating the potential use of these quantitative features for monitoring fibrotic changes during the progression of liver diseases. Therefore, multiphoton imaging combined with automatic image processing method would hold a promising future in rapid and label-free diagnosis of liver diseases.

Aberrant regulation of autophagy disturbs fibrotic liver regeneration after partial hepatectomy.

Reports indicate that autophagy is essential for maintaining hepatocyte proliferative capacity during liver regeneration. However, the role of autophagy in fibrotic liver regeneration is incompletely elucidated. We investigated the deregulation of autophagic activities in liver regeneration after partial hepatectomy using a CCl4-induced fibrosis mouse model. The baseline autophagic activity was significantly increased in the fibrotic liver. After 50% partial hepatectomy (PHx), liver regeneration was remarkably decreased, accompanied by increased hepatocyte size and binuclearity ratio. Moreover, the expression of autophagy-related proteins was functionally deregulated and resulted in a reduction in the number of autophagosome and autophagosome-lysosome fusions. We further showed upregulation of autophagy activities through verapamil administration, improved hepatocyte proliferation capacity, and restricted cellular hypertrophy and binuclearity ratio. In conclusion, we demonstrated that the impairment of liver regeneration is associated with aberrant autophagy in fibrotic liver and that enhancing autophagy with verapamil may partially restore the impaired liver regeneration following PHx.

[Role of mPGES-1 in the occurrence, progression, metastasis and invasion of hepatocellular carcinoma].

OBJECTIVE: To study the expression of mPGES-1 in hepatocellular carcinoma (HCC), observe the effect of MK886 on down-regulation of mPGES-1 gene expression on the biology of human hepatocarcinoma cell line HepG2 and to investigate its significance in the occurrence, progression, metastasis and invasion. METHODS: HCC tissues, para-carcinoma tissues, far-carcinoma tissues and normal liver tissues were collected. The expressions of mPGES-1 were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The proliferation, adherence, migration and invasion abilities of HepG2 cells interfered by MK886 were assessed by MTT and transwell technique respectively. RESULTS: The expression of mPGES-1 in HCCs was higher than that in normal liver tissues (P < 0.01), which increased following histological grade. Furthermore, mPGES-1 expression level was higher in the capsule invasion and metastasis tumor than in primary locus. A significant dose-dependent down-regulation of expressions of mPGES-1 gene mRNA and protein were observed in HepG2 cells when MK886 was given for 48 h (F = 140.402, P < 0.01; a'= 0.00714, P < 0.01). Compared with the control group, the growth inhibitory rate of HepG2 cell was observed significantly time and dose-dependent when MK886 was given. The rate of adhesion cells in experimental groups were 85.3% ± 1.3%, 70.5% ± 1.5% and 45.8% ± 2.4%, respectively, less than that in control group 100.0% ± 0 (F = 626.313, P < 0.01). The migration cells was 92.47 ± 1.90, 62.63 ± 1.96 and 37.33 ± 0.83 respectively in the experimental groups after 24 h, lower than that in the control group 128.93 ± 2.60 (F = 1253.805, P < 0.01). The invasion assay revealed that the invading cells were 41.67 ± 1.30, 25.47 ± 1.30 and 13.93 ± 1.66 in the experimental groups, in contrast to 55.67 ± 2.08 in control group after 24 h. The difference between these groups was significant (F = 372.615, P < 0.01). The numbers of adhesion, migration and invasion of HepG2 cells were dose-dependent in MK886 groups. CONCLUSION: Over-expression of mPGES-1 was associated with the tumorigenesis and progression of HCC. The down-regulation of mPGES-1 gene expression might indicated the decrease of the invasion and metastasis of HCC.

Verapamil induces autophagy to improve liver regeneration in non-alcoholic fatty liver mice.

Verapamil can restore intracellular calcium homeostasis, increase the fusion of autophagosomes and lysosomes, reduce lipid droplet accumulation and inhibit inflammation and insulin resistance in high-fat-fed mice. The present study aimed to investigate verapamil's effect and its underlying liver regeneration mechanism in mice with non-alcoholic fatty liver. After 50% hepatectomy was performed, the changes of autophagy and liver regeneration were evaluated by detecting cell proliferation and autophagy at each time point. Then, 25mg/kg verapamil was injected intraperitoneally for 10 d before an operation in the mild to moderate fatty liver and severe fatty liver groups. The control group and mild to moderate fatty liver group reached the peak of proliferation at 24-48h after operation, and the mice with severe fatty liver and steatohepatitis reached the peak at 48-72h. Autophagy in the normal group and mild to moderate fatty liver group reached the peak 48 hours after operation. Verapamil injection can enhance autophagy, reduce the weight of fatty liver mice, improve liver function and liver regeneration. Verapamil can induce autophagy, improve hepatocyte function and promote hepatocyte regeneration through the mTOR independent signaling pathway, thus improving the process of liver regeneration after partial hepatectomy.

A Prognostic Scoring System for Predicting Overall Survival of Patients with the TNM 8th Edition Stage I and II Hepatocellular Carcinoma After Surgery: A Population-Based Study.

PURPOSE: Postoperative prognosis prediction models for patients with stage Ⅰ and Ⅱ hepatocellular carcinoma (HCC) according to the 8th edition of the Tumor-Node-Metastasis staging system after surgery are rare. This study aimed to build a prognostic score to predict survival outcomes and stratify these patients into different prognostic strata. PATIENTS AND METHODS: We developed a web-based nomogram that incorporated four selected risk factors based on the multivariate Cox regression, using a training set (n=3567) from the Surveillance, Epidemiology, and End Results (SEER) database. It was validated with an independent internal set from the SEER database (n=1783) and an external validation set of 516 Chinese patients. The predictive performance and discrimination ability of our model were further evaluated and compared with those of the conventional HCC staging systems. RESULTS: Our nomogram consistently outperformed the conventional staging systems in the training, internal validation set, and external validation set. We quantified the nomogram model into a numerical SNIG (an abbreviation of the incorporated variables - size, number, MVI, and grade) score by summing the points assigned to each incorporated variable, leading to the optimal cut-off values of 6 and 10, which could stratify patients into 3 categories (SNIG score <6, 6-10, ≥10). This yielded significantly different median overall survivals (interquartile ranges) of 42.0 (20.0-72.0) and 37.0 (17.0-67.0); 28.0 (12.0-60.0) and 42.0 (21.75-82.0); 40.0 (18.0-70.0) and 29.0 (11.5-61.0) months for the 3 categories in the entire SEER and external validation sets, respectively. CONCLUSION: We developed a web-based SNIG model to graphically and numerically predict the overall survival of stage Ⅰ and Ⅱ HCC. This scoring system may shed light on risk stratification for these patients in clinical practice and clinical trials.