Case report: Primary myelofibrosis presenting with portal hypertension mimicking cirrhosis.

Primary myelofibrosis (PMF) is an infrequent etiology of noncirrhotic portal hypertension (PH). In clinical settings, non-cirrhotic PH is often misdiagnosed as cirrhotic PH. This case report details a patient who exhibited recurrent esophageal variceal hemorrhage and was initially misdiagnosed with cirrhosis. Initially poised for liver transplantation, the patient's liver biopsy revealed no significant cirrhosis but showed signs of extramedullary hematopoiesis (EMH). Following the accurate diagnosis of PMF, the patient underwent standard treatment, leading to an absence of recurrent gastrointestinal hemorrhage due to esophageal varices for nearly three years.

Non-Hodgkin's Lymphoma Presenting as Isolated Peritoneal Lymphomatosis: A Case Report and Literature Review.

Peritoneal lymphomatosis is extremely rare and associated with poor prognosis. Most practitioners only pay more attention to peritoneal carcinomatosis. However, peritoneal lymphomatosis can be neglected and misdiagnosed. We report a teenager with 10 days of abdominal distension and pain accompanied by computed tomography scan suggesting diffuse thickening of the peritoneum and omentum and abdominopelvic effusion. Tuberculous peritonitis and peritoneal carcinomatosis were initially suspected. However, it was finally confirmed as non-Hodgkin's B-cell lymphoma by omentum biopsies. He achieved complete remission after chemotherapy and autologous stem cell transplantation. But unfortunately, he suffered a relapse and died 10 months after diagnosis. Following a review of the literature, it can be concluded that the discovery of lymphomatosis in peritoneum is a rare finding. Lymphoma should be considered in the differential diagnosis of unexplained peritoneal thickening on computed tomography, and this case emphasizes the importance of early pathological diagnosis to make sure that the right treatment can be started opportunely.

Long non-coding RNA LINC01116 acts as an oncogene in prostate cancer cells through regulation of miR-744-5p/UBE2L3 axis.

BACKGROUND: Long non-coding RNA (lncRNA) has been confirmed to exert a critical effect on the progression of tumors, including prostate cancer. Previous literature has demonstrated LINC01116 involves in activities of multiple cancers. However, the underlying role of LINC01116 in prostate cancer remains unclear. METHODS: qRT-PCR measured the expression of LINC01116 in prostate cancer cells. EdU experiment was used to detect cell proliferation. Transwell assays detected cell migration and invasion. Immunofluorescence staining and western blot assays were utilized to measure EMT progress. The binding relationship between RNAs was confirmed by a series of mechanism assays. In addition, rescue experiments were conducted to verify the relationship among RNAs. RESULTS: LINC01116 was found to be highly expressed in prostate cancer cells. Functional assays indicated that inhibition of LINC01116 could suppress cell proliferation, migration, invasion and EMT progress. Also, miR-744-5p was proven to bind with LINC01116. Moreover, UBE2L3 was verified as the target gene of miR-744-5p. In rescue assays, we discovered that inhibited miR-744-5p or overexpressed UBE2L3 could offset the suppressive influence of silencing LINC01116 on prostate cancer cells. CONCLUSION: Our study suggested that lncRNA LINC01116 acted as an oncogene in prostate cancer and accelerated prostate cancer cell growth through regulating miR-744-5p/UBE2L3 axis.

Inhibition of stearoyl-coenzyme A desaturase 1 ameliorates hepatic steatosis by inducing AMPK-mediated lipophagy.

SCD1 is a key enzyme controlling lipid metabolism and a link between its activity and NAFLD has been proposed. Lipophagy is a novel regulatory approach to lipid metabolism regulation, which is involved in the development of NAFLD. However, the possible functional connection between SCD1 and lipophagy in NAFLD remains unknown. To investigate the molecular mechanisms through which SCD1 regulates lipophagy in hepatic steatosis, the model of hepatic steatosis was established by inducing mouse primary hepatocytes with sodium palmitate and feeding C57BL/6 mice with HFD. Our results indicated that sodium palmitate-treated hepatocytes exhibited increased SCD1 expression, AMPK inactivation and defective lipophagy. Inhibition of SCD1 expression in hepatocytes resulted in enhanced AMPK activity and lipophagy, and reduced lipid deposition. Although SCD1 overexpression led to decreased AMPK activity and lipophagy, lipid deposition was increased in hepatocytes. SCD1 regulated lipophagy through AMPK to affect lipid metabolism in mouse primary hepatocytes. Additionally, compared to HFD-fed mice, CAY10566(an SCD1-specific inhibitor)-treated mice exhibited significantly decreased hepatic steatosis and hepatic lipid droplet accumulation, as well as enhanced AMPK activity and lipophagy. This study elucidated that SCD1 inhibition ameliorates hepatic steatosis by inducing AMPK-mediated lipophagy, suggesting that the SCD1-AMPK-lipophagy pathway is a potential therapeutic target for NAFLD.

LXRɑ participates in the mTOR/S6K1/SREBP-1c signaling pathway during sodium palmitate-induced lipogenesis in HepG2 cells.

BACKGROUND: The aim of this study was to investigate how the signaling pathway downstream of mTOR/S6K1 contributes to the regulation of SREBP-1c expression during lipogenesis in HepG2 cells. METHODS: The model of steatosis was established using human hepatocytes HepG2 and inducting them with sodium palmitate. mTOR, S6K1 and LXRα were inhibited by rapamycin, PF-4708671 and siRNA-LXRα, respectively. After a variety of different treatment, the levels of intracellular triglycerides, the accumulation of lipid droplets and the expression levels of related genes were detected. RESULTS: Rapamycin, PF-4708671 and siRNA-LXRα treatment could decrease the accumulation of triglycerides and lipid droplets induced by sodium palmitate in HepG2 cells, and the inhibitory effect could be enhanced by the combination of them. Sodium palmitate stimulated the expression of genes encoding mTOR, S6K1, LXRα, SREBP-1c and SREBP-1c target enzymes (FAS and ACC1) in HepG2 cells. Moreover, these genes were sensitive to rapamycin. PF-4708671 also decreased the expression of these genes, except for the mTOR gene, and the extent of reduction could be enhanced by combination with rapamycin. Knockdown of LXRα decreased the expression of SREBP-1c, FAS and ACC1, but it had no effect on the expression of mTOR or S6K1. Furthermore, rapamycin and PF-4708671 enhanced the inhibitory effect of siRNA-LXRα. CONCLUSIONS: mTOR/S6K1 regulates the SREBP-1c signaling pathway through LXRα in sodium palmitate-induced HepG2 cells, suggesting LXRα might be a potential therapeutic target for NAFLD.

Histone modifications in fatty acid synthase modulated by carbohydrate responsive element binding protein are associated with non­alcoholic fatty liver disease.

Non­alcoholic fatty liver disease (NAFLD) is a manifestation of metabolic syndrome in the liver and is closely associated with diabetes; however, its pathogenesis remains to be elucidated. Carbohydrate responsive element binding protein (ChREBP), the hub of glucolipid metabolism, regulates the induction of fatty acid synthase (FASN), the key enzyme of de novo lipogenesis, by directly binding to carbohydrate response element (ChoRE) in its promoter. Investigations of histone modifications on NAFLD remain in their infancy. In the present study, by using ChIP, the association between histone modifications and FASN transcription was investigated and histone modifications in FASN modulated by ChREBP were measured. It was demonstrated that ChREBP induced FASN ChREBP­ChoRE binding to accelerate the expression of FASN, leading to hepatocellular steatosis by facilitating H3 and H4 acetylation, H3K4 trimethylation and the phosphorylation of H3S10, but inhibiting the trimethylation of H3K9 and H4K20 in FASN promoter regions of HepG2 and L02 cells. It was also found that ChREBP­ChoRE binding of FASN relied on histone acetylation and that the transcriptional activity of ChREBP on FASN is required, based on the premise that histone acetylation causes conformational changes in FASN chromatin. This indicated histone acetylation as a crucial mechanism involved in the transcription of FASN modulated by ChREBP. Consequently, the present study provides further insight into the pathophysiology and a novel therapeutic potential of NAFLD based on epigenetic mechanisms.

Histone modifications in FASN modulated by sterol regulatory element-binding protein 1c and carbohydrate responsive-element binding protein under insulin stimulation are related to NAFLD.

Non-alcoholic fatty liver disease (NAFLD) and its causal factors of hepatic insulin resistance (IR) and type 2 diabetes are rapidly growing worldwide. Developing new therapeutic methods for these conditions requires a comprehensive understanding between hepatic lipid metabolism and IR. Sterol regulatory element-binding transcription factor 1c (SREBP-1c) and carbohydrate responsive-element binding protein (ChREBP) are the major regulators of fatty acid synthase (FASN), a key enzyme of de novo fatty acid synthesis. They are induced by insulin, which directly binds to the sterol regulatory elements (SRE) or carbohydrate-responsive elements (ChORE) of the FASN promoter to induce its expression. The insulin pathway involved in NAFLD has well studied, but the role of histone modification in NAFLD is just beginning to be investigated, and there is minimal data regarding its involvement. In the current study, we investigated histone modifications in FASN under insulin stimulation. H3K4 hypertrimethylation and H3, H4 hyperacetylation in the FASN promoter was found in HepG2 cells and primary hepatocytes following insulin stimulation. We also found that insulin treatment induced the transcription factor SREBP-1c, ChREBP and could accelerate FASN expression by enhancing SREBP-1c, SRE, and ChREBP ChORE binding and inducing H3, H4 hyperacetylation at SRE, ChORE, or transcription start site (TSS) regions of the FASN promoter in hepatocellular carcinoma cell line (HepG2) and primary hepatocytes. Finally, histone acetylation could influence FASN expression by impairing SREBP-1c SRE and ChREBP ChORE binding.

Endoplasmic reticulum stress leads to lipid accumulation through upregulation of SREBP-1c in normal hepatic and hepatoma cells.

Endoplasmic reticulum stress (ERS) has been found in non-alcoholic fatty liver disease. The study was to further explore the mechanistic relationship between ERS and lipid accumulation. To induce ERS, the hepatoblastoma cell line HepG2 and the normal human L02 cell line were exposed to Tg for 48 h. RT-PCR and Western blot were performed to evaluate glucose-regulated protein (GRP-78) expression as a marker of ERS. ER ultrastructure was assessed by electron microscopy. Triglyceride content was examined by Oil Red O staining and quantitative intracellular triglyceride assay. The hepatic nuclear sterol regulatory element-binding protein (SREBP-1c), liver X receptor (LXRs), fatty acid synthase (FAS), and acetyl-coA carboxylase (ACC1) expressions were examined by real-time PCR and Western blot. 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF) was used to inhibit S1P serine protease inhibitor, and SREBP-1c cleavage was evaluated under ERS. SREBP-1c was knockdown and its effect on lipid metabolism was observed. Tg treatment upregulated GRP-78 expression and severely damaged the ER structure in L02 and HepG2 cells. ERS increased triglyceride deposition and enhanced the expression of SREBP-1c, FAS, and ACC1, but have no influence on LXR. AEBSF pretreatment abolished Tg-induced SREBP-1c cleavage. Moreover, SREBP-1c silencing reduced triglycerides and downregulated FAS expression. Pharmacological ERS induced by Tg leads to lipid accumulation through upregulation of SREBP-1c in L02 and HepG2 cells.

Saturated fatty acid induction of endoplasmic reticulum stress and apoptosis in human liver cells via the PERK/ATF4/CHOP signaling pathway.

Accumulation of saturated fatty acids in the liver can cause nonalcoholic fatty liver disease (NAFLD). This study investigated saturated fatty acid induction of endoplasmic reticulum (ER) stress and apoptosis in human liver cells and the underlying causal mechanism. Human liver L02 and HepG2 cell lines were exposed to the saturated fatty acid sodium palmitate. MTT assay was used for cell viability, flow cytometry and Hoechst 33258 staining for apoptosis, RT-PCR for mRNA expression, and Western blot for protein expression. Silence of PRK-like ER kinase (PERK) expression in liver cells was through transient transfection of PERK shRNA. Treatment of L02 and HepG2 cells with sodium palmitate reduced cell viability through induction of apoptosis. Sodium palmitate also induced ER stress in the cells, indicated by upregulation of PERK phosphorylation and expression of BiP, ATF4, and CHOP proteins. Sodium palmitate had little effect on activating XBP-1, a common target of the other two canonical sensors of ER stress, ATF6, and IRE1. Knockdown of PERK gene expression suppressed the PERK/ATF4/CHOP signaling pathway during sodium palmitate-induced ER stress and significantly inhibited sodium palmitate-induced apoptosis in L02 and HepG2 cells. Saturated fatty acid-induced ER stress and apoptosis in these human liver cells were enacted through the PERK/ATF4/CHOP signaling pathway. Future study is warranted to investigate the role of these proteins in mediating saturated fatty acid-induced NAFLD in animal models.

Involvement of liver X receptor alpha in histone modifications across the target fatty acid synthase gene.

The liver X receptor alpha (LXRα), a member of the nuclear receptor superfamily, has been shown to regulate the expression of the fatty acid synthase (FAS) gene through direct interaction with the FAS promoter. However, its regulation of gene expression is not completely understood. Histone modifications and chromatin remodeling are closely linked to transcriptional activation of genes. In the present study, we examined the effect of LXRα activation or silencing on histone modifications (i.e., acetylation, methylation, and phosphorylation) across the FAS gene, with the aim to investigate whether LXRα could regulate its target gene expression at the epigenetic level. The addition of LXR agonist T0901317 or ectopic expression of LXRα stimulated the FAS transcription, which was coupled with increased levels of histones H3 and H4 acetylation and H3 phosphorylation and methylation at the LXR response element (LXRE). LXR ligation or overexpression induced distinct histone modification patterns at the distal region 2,272 bp upstream from the transcription start site (TSS) and TSS of the FAS gene. Moreover, RNA interference-mediated downregulation of LXRα impaired the histone acetylation and methylation but not phosphorylation on the FAS gene. In conclusion, we provide evidence that LXRα ligation-mediated transcriptional activation of the FAS gene is associated with LXRα-dependent histone acetylation and methylation rather than phosphorylation on this target gene.