Maurycy Jonas

SIRT1 and SIRT7 expression in adipose tissues of obese and normal-weight individuals is regulated by microRNAs but not by methylation status

Background/Objective:Given their importance in the regulation of metabolism, sirtuins (SIRTs) constitute promising subjects of research on the pathogenesis of obesity and the metabolic syndrome. The aim of this study was to assess whether obesity in humans is associated with changes in the expression of SIRT genes in adipose tissue and whether epigenetic mechanisms, DNA methylation and microRNA (miRNA) interference, mediate in this phenomenon.Subjects/Methods:The expression of SIRTs and of SIRT1 and SIRT7 mRNA-interacting miRNAs was evaluated by real-time PCR in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of 58 obese (body mass index (BMI) >40 kg m−2) and 31 normal-weight (BMI 20–24.9 kg m−2) individuals. The methylation status of SIRTs was studied by the methylation-sensitive digestion/real-time PCR method.Results:SIRT1 mRNA levels were lower in adipose tissues of obese patients than of normal-weight controls (VAT: P=0.0002, SAT: P=0.008). In contrast, expression of SIRT7 was higher in adipose tissues of obese patients than in the control group (VAT: P=0.001, SAT: P=0.008). The mean methylation of the SIRT1 and SIRT7 CpG islands was similar in tissues with high and low expression of these genes, and there was no correlation between the level of expression and the level of methylation. On the other hand, expression of SIRT1 in VAT of obese subjects correlated negatively with the expression of miR-22-3p (P<0.0001, rs=−0.514), miR-34a-5p (P=0.01, rs=−0.326) and miR-181a-3p (P<0.0001, rs=−0.536). In turn, expression of SIRT7 in VAT of slim individuals correlated negatively with the expression of miR-125a-5p (P=0.003, rs=−0.562) and miR-125b-5p (P=0.018, rs=−0.460).Conclusions:We observed obesity-associated downregulation of SIRT1 and upregulation of SIRT7 mRNA levels that were not associated with the methylation status of their promoters. We found a negative correlation between mRNA levels of SIRT1 in VAT of obese individuals and SIRT7 in VAT of the normal-weight subjects and expression of the relevant miRNAs.

Interleukins 6 and 15 Levels Are Higher in Subcutaneous Adipose Tissue, but Obesity Is Associated with Their Increased Content in Visceral Fat Depots

Excess adiposity is associated with chronic inflammation, which takes part in the development of obesity-related complications. The aim of this study was to establish whether subcutaneous (SAT) or visceral (VAT) adipose tissue plays a major role in synthesis of pro-inflammatory cytokines. Concentrations of interleukins (IL): 1β, 6, 8 and 15 were measured at the protein level by an ELISA-based method and on the mRNA level by real-time PCR in VAT and SAT samples obtained from 49 obese (BMI > 40 kg/m2) and 16 normal-weight (BMI 20–24.9 kg/m2) controls. IL-6 and IL-15 protein concentrations were higher in SAT than in VAT for both obese (p = 0.003 and p < 0.0001, respectively) and control individuals (p = 0.004 and p = 0.001, respectively), while for IL-1β this was observed only in obese subjects (p = 0.047). What characterized obese individuals was the higher expression of IL-6 and IL-15 at the protein level in VAT compared to normal-weight controls (p = 0.047 and p = 0.016, respectively). Additionally, obese individuals with metabolic syndrome had higher IL-1β levels in VAT than did obese individuals without this syndrome (p = 0.003). In conclusion, concentrations of some pro-inflammatory cytokines were higher in SAT than in VAT, but it was the increased pro-inflammatory activity of VAT that was associated with obesity and metabolic syndrome.

The First Polish Liver Transplantation after Roux-en-Y Gastric Bypass Surgery for Morbid Obesity: A Case Report and Literature Review

BACKGROUND Morbid obesity is associated with liver pathology, most commonly non-alcoholic steatohepatitis (NASH) leading to cirrhosis. However, the morbid obesity impedes qualification for organ transplantation. CASE REPORT We present a case report of a 56-year-old woman who underwent bariatric procedure followed by liver transplantation (LTx). Her initial weight was 130.2 kg (BMI 50.9 kg/m2). The patient had a history of arterial hypertension, diabetes, gonarthrosis, and obstructive sleep apnea syndrome and no history of alcohol abuse. She underwent Roux-en-Y gastric bypass (RYGB) procedure. The routine intraoperative liver biopsy revealed fibrosis (III°), steatosis (II°), and intra-acinar inflammation. The operation led to a substantial loss of weight. Two years after the surgery the patient was referred to the Transplantation Clinic of Department of General Surgery and Transplantology with suspicion of liver failure due to advanced cirrhosis, which could be a result of previously diagnosed NASH and, probably, excessive alcohol use after bariatric surgery. The patient was qualified for elective LTx, which was performed 3 years after the RYGB. Immediately before LTx, the patients weight was 65 kg (BMI 25.4 kg/m²). The postoperative period was complicated by bleeding into the peritoneal cavity, which required reoperation. She also had renal failure, requiring renal replacement therapy. One year after LTx, she showed stable liver function with normal transaminases activity and bilirubin concentration, remission of diabetes, and good renal function. CONCLUSIONS Steatohepatitis in morbidly obese patients may lead to cirrhosis. Bariatric procedure can be a bridge to liver transplantation for morbidly obese patients with advanced liver fibrosis.

Accelerated hepatocellular carcinoma recurrence rate after postoperative direct-acting antivirals treatment – preliminary report

Aim of the study New interferon-free direct-acting antiviral (DAA) therapy has led to major progress in hepatitis C virus (HCV) treatment. Current outcomes are promising, especially in compensated cirrhosis. However, there are reports of accelerated hepatocellular carcinoma (HCC) recurrence after surgery in patients treated with DAAs. The influence of DAA therapy on the timing and frequency of recurrence after surgical treatment needs further observation. Material and methods Fifty-one HCV infected patients with advanced liver cirrhosis and history of surgical treatment for HCC in 2012-2016 were analyzed in a case-control study. Nineteen patients received DAA therapy (DAA group) after tumor remission achieved by surgery and 32 patients were not treated with DAA (NDAA group). Follow-up included multiphase computed tomography scan or magnetic resonance imaging of the liver and alpha-fetoprotein level in 3-6-month intervals. Results An sustained virological response was achieved in 18 (95%) DAA treated patients. Hepatocellular carcinoma recurrence was observed in 8 (42.1%) patients from the DAA group and in 21 (65.6%) from the NDAA group (p = 0.058). Relapse occurred within 265 days after surgery in the DAA group vs. 532 days in the NDAA group (p = 0.033). The one-year recurrence-free survival (RFS) rate was 47.3% vs. 75% in the DAA and NDAA group respectively (p = 0.45). Conclusions Use of DAA therapy in patients with a history of HCC may result in significantly accelerated relapse of the disease. The number of analyzed patients in this study is too small to state unquestionable conclusions. Further observation with a longer follow-up and larger patient group is needed. The study confirms that contemporary HCV treatment is highly effective.

The epidemiology of hepatocellular cancer in Poland

Introduction This article summarize the available data on hepatocellular carcinoma (HCC) epidemiology in Poland. Data regarding the HCC incidence rate are divergent. Statistical data presented by NFZ appear more credible in that matter than data published by the Polish Oncology Center (POC). Material and methods The analysis included data from the Polish Bibliography Database (GBL), the Polish National Health Fund Institution (NFZ), the scientific paper “Malignant neoplasms in Poland” issued by POC and the central liver transplant registry maintained by the Polish transplant coordinating center “Poltransplant” (2010-2015). Results Data regarding the HCC incidence rate are divergent. Statistical data presented by NFZ appear more credible in that matter than data published by POC. Conclusions The occurrence of HCC in Poland is at the average European level and is similarly rising. The incidence rate is underestimated. It is due to faulty epidemiology data collection techniques. The highest risk group comprises men over the age of 50 with concomitant liver cirrhosis. The most common HCC etiology is HCV infection.

NGS Reveals Molecular Pathways Affected by Obesity and Weight Loss-Related Changes in miRNA Levels in Adipose Tissue

Both obesity and weight loss may cause molecular changes in adipose tissue. This study aimed to characterize changes in adipose tissue miRNome in order to identify molecular pathways affected by obesity and weight changes. Next generation sequencing (NGS) was applied to identify microRNAs (miRNAs) differentially expressed in 47 samples of visceral (VAT) and subcutaneous (SAT) adipose tissues from normal-weight (N), obese (O) and obese after surgery-induced weight loss (PO) individuals. Subsequently miRNA expression was validated by real-time PCR in 197 adipose tissues and bioinformatics analysis performed to identify molecular pathways affected by obesity-related changes in miRNA expression. NGS identified 344 miRNAs expressed in adipose tissues with ≥5 reads per million. Using >2 and <−2 fold change as cut-offs we showed that the expression of 54 miRNAs differed significantly between VAT-O and SAT-O. Equally, between SAT-O and SAT-N, the expression of 20 miRNAs differed significantly, between SAT-PO and SAT-N the expression of 79 miRNAs differed significantly, and between SAT-PO and SAT-O, the expression of 61 miRNAs differed significantly. Ontological analyses disclosed several molecular pathways regulated by these miRNAs in adipose tissue. NGS-based miRNome analysis characterized changes of the miRNA profile of adipose tissue, which are associated with changes of weight possibly responsible for a differential regulation of molecular pathways in adipose tissue when the individual is obese and after the individual has lost weight.