Prolyl endopeptidase remodels macrophage function as a novel transcriptional coregulator and inhibits fibrosis.

Macrophages are immune cells crucial for host defense and homeostasis maintenance, and their dysregulation is involved in multiple pathological conditions, such as liver fibrosis. The transcriptional regulation in macrophage is indispensable for fine-tuning of macrophage functions, but the details have not been fully elucidated. Prolyl endopeptidase (PREP) is a dipeptidyl peptidase with both proteolytic and non-proteolytic functions. In this study, we found that Prep knockout significantly contributed to transcriptomic alterations in quiescent and M1/M2-polarized bone marrow-derived macrophages (BMDMs), as well as aggravated fibrosis in an experimental nonalcoholic steatohepatitis (NASH) model. Mechanistically, PREP predominantly localized to the macrophage nuclei and functioned as a transcriptional coregulator. Using CUT&Tag and co-immunoprecipitation, we found that PREP was mainly distributed in active cis-regulatory genomic regions and physically interacted with the transcription factor PU.1. Among PREP-regulated downstream genes, genes encoding profibrotic cathepsin B and D were overexpressed in BMDMs and fibrotic liver tissue. Our results indicate that PREP in macrophages functions as a transcriptional coregulator that finely tunes macrophage functions, and plays a protective role against liver fibrosis pathogenesis.

Preliminary study on the inhibitory effect of tumor suppressor gene KPC1 on the proliferation in gastric carcinoma cell.

BACKGROUND: To investigate Kip1 ubiquitination-promoting complex 1 (KPC1) expression and its relationship with NF-κB p50 in gastric cancer cell lines. METHODS: The expression of KPC1 and NF-κB p50 in tissue samples from 159 gastric cancer patients after tumor resection and normal gastric mucosa samples from 56 patients as negative controls was retrospectively studied. The relationship between KPC1, NF-κB p50, and clinicopathological factors was analyzed, and the correlation between KPC1 and cytoplasmic NF-κB p50 was determined. The expression level of KPC1 and NF-κB p50 was researched using reverse transcription (RT) polymerase chain reaction (RT-PCR) and Western blotting in 3 differentiated human gastric cancer cell lines (AGS, SGC-7901 and MGC-803). RESULTS: Immunohistochemistry indicated that KPC1 and NF-κB p50 expression was significantly decreased in gastric cancer cases, and the level of expression varied across the differentiated gastric cancer tissues. KPC1 and NF-κB p50 expression was significantly connected with tumor differentiation, tumor-node-metastasis (TNM) staging, and metastasis of 159 patients suffering from gastric cancer (P<0.05), but not correlated with age and lesion size (P>0.05). KPC1 was positively connected with the expression of NF-κB p50 by the Spearman correlation analysis (r=0.427, P<0.05). The expression of KPC1 and NF-κB p50 mRNA was reduced, and there were differences in the 3 differentiated human gastric cancer cell lines, as confirmed by western blotting. CONCLUSIONS: The co-expression of KPC1 and cytoplasmic NF-κB p50 in gastric cancer promotes tumor suppressor gene expression. Therefore, limiting the growth of tumor cells may inhibit the development of gastric cancer.

Pathogenesis and Prevention of Radiation-induced Myocardial Fibrosis

Radiation therapy is one of the most important methods for the treatment of malignant tumors. However, in radiotherapy for thoracic tumors such as breast cancer, lung cancer, esophageal cancer, and mediastinal lymphoma, the heart, located in the mediastinum, is inevitably affected by the irradiation, leading to pericardial disease, myocardial fibrosis, coronary artery disease, valvular lesions, and cardiac conduction system injury, which are considered radiation-induced heart diseases. Delayed cardiac injury especially myocardial fibrosis is more prominent, and its incidence is as high as 20­80%. Myocardial fibrosis is the final stage of radiation-induced heart diseases, and it increases the stiffness of the myocardium and decreases myocardial systolic and diastolic function, resulting in myocardial electrical physiological disorder, arrhythmia, incomplete heart function, or even sudden death. This article reviews the pathogenesis and prevention of radiation-induced myocardial fibrosis for providing references for the prevention and treatment of radiation-induced myocardial fibrosis.

HOXB8 promotes tumor metastasis and the epithelial-mesenchymal transition via ZEB2 targets in gastric cancer.

PURPOSE: The homeobox B8 (HOXB8) functions as a sequence-specific transcription factor that is involved in development. Increased expression of this gene is associated with a wide variety of tumor; however, its function in gastric cancer has not been clarified. In the present study, the expression of HOXB8 in gastric cancer tissues and influence of HOXB8 on gastric cancer cellular were evaluated. METHODS: The expression levels of HOXB8 mRNA in human gastric cancer tissues were analyzed through quantitative RT-PCR. To test the role of HOXB8 in gastric cancer metastasis, the cell transwell assay was performed. Microarray, ChIP-qPCR, and Western blot were used to explore the possible mechanism that HOXB8 promotes gastric cancer cells metastasis. RESULTS: In this study, we found that HOXB8 showed higher expression in metastatic tissues than no-metastatic tissues. Overexpression of HOXB8 can promote gastric cancer cells migration and invasion, while silencing HOXB8 leads to the opposite results. Overexpression of HOXB8 also increases the rate of metastasis in NCI-N87 mice, while silencing HOXB8 has the opposite results. Furthermore, HOXB8 promotes epithelial-mesenchymal transformation of AGS cells. We also found that ZEB2 can interact with HOXB8 and may be a downstream factor of HOXB8 by using microarray. Knockdown of ZEB2 can inhibit HOXB8-induced migration and invasion capacity, as well as the epithelial-mesenchymal transformation in gastric cancer cells. CONCLUSIONS: The results showed that HOXB8 plays an important role in the development and metastasis of gastric carcinoma.

Thyroid function is associated with non-alcoholic fatty liver disease in chronic hepatitis B-infected subjects.

BACKGROUND AND AIMS: Associations between thyroid function and non-alcoholic fatty liver disease (NAFLD) are unknown in chronic hepatitis B (CHB)-infected patients. Thus, the aim of the study was to investigate the prevalence of thyroid dysfunction and its relationship with NAFLD in CHB. METHODS: Consecutive naive CHB infected patients that had undergone liver biopsy and serum thyroid function tests between January 2007 and December 2011 were retrospective analyzed. NAFLD was diagnosed as at least 5% biopsy-proven hepatic steatosis without significant alcohol consumption. RESULTS: A total of 1154 non-alcoholics with CHB were included, 270 (23.39%) patients were found to have NAFLD, most of them (88.5%) with mild steatosis. The prevalence of hyperthyroidism and hypothyroidism (including subclinical and overt) was 1.56% and 1.64%, respectively, both with similar rates in patients with and without NAFLD (1.85% vs 1.47%, 1.48% vs 1.69%, respectively, both P > 0.05). The serum thyroid-stimulating hormone (TSH) level in NAFLD patients was significantly higher than that in patients without NAFLD (2.22 ± 2.13 vs 1.61 ± 1.20 mIU/L, P < 0.05). After adjustment for age and gender, the elevated TSH level was associated with increased odds of having steatosis (odds ratio1.54, 95% confidence interval 1.049-2.271) instead of viral factors and hepatic inflammation and fibrosis. CONCLUSIONS: Thyroid dysfunction is not common in CHB-infected patients, and the prevalence of hypothyroidism in CHB individuals with or without NAFLD is similar. However, increased serum TSH concentration at the normal range is a significant predictor of hepatic steatosis in patients with CHB.

High-saturate-fat diet delays initiation of diethylnitrosamine-induced hepatocellular carcinoma.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a risk factor for hepatocellular carcinoma (HCC), but the association between a high-fat diet (HFD) and HCC is not fully understood. In this study, we investigated whether a high-saturate-fat diet affects hepatocarcinogenesis induced by administration of diethylnitrosamine (DEN). METHODS: Adult SD rats were randomized into the following groups: normal chow diet (NCD), HFD, NCD + DEN, and HFD + DEN. The HFD contains 2% cholesterol and 10% lard oil. In mice with DEN treatment, the carcinogen was given via gavage. Mice were sacrificed at the end of 10, 12, and 14 weeks, respectively. The effects of HFD on hepatic carcinogenesis were assessed by HCC incidence, tumor differentiation, and the number and size of tumor nodules. Western blot and immunohistochemistry for proliferating cell nuclear antigen (PCNA), enzyme-linked immunosorbent assay (ELISA) for caspase-3, and real-time PCR for TNF-α and IL-6 further uncovered the proliferative and apoptotic properties of liver. RESULTS: In contrast to the NCD group, DEN treatment (NCD + DEN group) led to hepatitis, cirrhosis, hepatic tumor, and decreased body weight. Interestingly, HFD, which induced hyperlipidemia and hepatic steatosis, attenuated DEN-related malnutrition and fibrosis progression in HFD + DEN group during 10-14 weeks. Moreover, the HFD + DEN group exhibited that the proportion of well differentiated HCC was much higher than that of NCD + DEN group. The number and average volume of HCC node were also significantly lowered in HFD + DEN group (P < 0.01-0.05). When compared to that of NCD + DEN group, there was an inhibited expression of PCNA, TNF-α, and IL-6, and activation of caspase-3 in the liver of HFD + DEN group at week 10 and 12. CONCLUSIONS: HFD restores malnutrition in the DEN-treated rats, which in turn inhibits the initiation of hepatic carcinogenesis and malignancy.

Regulation of adipokines by polyunsaturated fatty acids in a rat model of non-alcoholic steatohepatitis.

BACKGROUND: Recent evidence has indicated that polyunsaturated fatty acids (PUFA), such as omega-3 PUFA, have protective effects on a range of chronic inflammatory conditions, including obesity, and may play a role in the reversal of steatohepatitis. However, the effects of omega-3 PUFA on adipokine expression and hepatic lipid metabolism have not been well evaluated. Thus, the aim of our study was to investigate the effects of PUFAs on adipokines, as well as lipid and glycometabolism, in a rat model of non-alcoholic steatohepatitis (NASH). METHODS: Male Sprague-Dawley rats were divided into control, model and therapy groups. The control group received a normal diet, while the model and therapy groups received a high-fat diet. On the eighth week of high-fat diet, the therapy group was treated with omega-3 PUFA (1.0 g/d) daily. At the end of 20 weeks, serum biochemistry indices were measured and adipokine levels in serum and liver samples were detected with ELISA, Western blotting and real time fluorescence quantitative PCR (qRT-PCR). RESULTS: The weight, biochemical parameters and adipokine levels in serum of the model group were elevated compared to the control group (P < 0.05). In addition, the protein and mRNA expression levels of adipokines in the liver were significantly altered compared to the control group (P < 0.01). The therapy group was characterized by decreased weight and biochemical indices (P < 0.05) compared with the model group. Supplementing high-fat diet with omega-3 PUFA decreased serum levels of leptin and resistin, while adiponectin levels were slightly elevated. In liver tissue samples, the protein and mRNA expression levels of adipokines were significantly improved (P < 0.01) in the therapy group compared to the model group. CONCLUSION: Omega-3 PUFA improved lipid and glycometabolism in NASH rats and regulated adipokine expression, indicating that omega-3 PUFA may have a therapeutic benefit for patients with NASH.

The expression and clinical significance of DNA methyltransferase proteins in human gastric cancer.

This study investigates the varied expression of DNA methyltransferase (DNMT) proteins in gastric cancer (GC) and their relationship with the biological behavior of the tissues. Immunohistochemistry was used to detect the expression of the 3 DNMTs in gastric tissues. We discovered that the positive rates of DNMT1, DNMT3a, and DNMT3b expression in GC tissues were 81.6%, 81.6%, and 68.4%, respectively, and they were significantly higher than those of both para-cancerous (39.5%, 50%, and 44.7%) and normal tissues (10.5%, 10.5%, and 7.9%). DNMT1 was well distributed in the cytoplasm and nuclei of tumor cells or glands, while DNMT3a and 3b were well distributed only in the cytoplasm, as shown by staining a dark brown color. A significant correlation between the DNMT1 and DNMT3a proteins (P < 0.01), a low correlation between DNMT3a and DNMT3b (P < 0.05), and no correlation between DNMT1 and DNMT3b (P > 0.05) were observed. DNMT1 protein expression exhibited no correlation with age, lymphnode metastasis, and also tumor differentiation, but it may have had a correlation with gender. The DNMT3 family was not associated with these factors. Therefore, DNMT overexpression is involved in gastric tumorigenesis, but there is no correlation between the DNMTs and the biological behaviors of tissues.