Maurizio Baldassarre

A novel model of CCl4-induced cirrhosis with ascites in the mouse

BACKGROUND/AIMS The current approaches to study the molecular mechanisms involved in the pathophysiology of liver diseases often rely on the use of transgenic mice. However, experimental models of decompensated cirrhosis have not been clearly established in mice. Thus, we aimed to set an efficient and well-tolerated protocol to induce cirrhosis in mice able to progress up to the ascitic stage. METHODS C57BL/6N mice received CCl(4) subcutaneously, intraperitoneally or by inhalation. In the latter group, gaseous CCl(4) was administered according to three different schedules: increasing exposure times, twice weekly (traditional protocol; TP), short inhalation cycles, twice or three times weekly. RESULTS Portal hypertension, sodium retention, and ascites developed in all groups between 11 and 15 weeks. Mortality reached 70% in the TP group, but it was only 0-10% with all other protocols. All the inhalation groups had significantly more ascites at sacrifice than those receiving CCl(4) subcutaneously and intraperitoneally. Extensive abdominal adhesions and evidence of enhanced hepatic inflammation, as suggested by the increased gene expression of pro-inflammatory cytokines in liver tissue, were found in the intraperitoneal group, while large granulomas at the injection site and marked neutrophil infiltration of lungs developed in the subcutaneous group. No extra-hepatic damage could be detected in mice inhaling CCl(4). CONCLUSIONS The use of short cycles of CCl(4) inhalation represents a novel, safe, and effective method to induce decompensated cirrhosis in mice. Intraperitoneal CCl(4) leads instead to abdominal adhesions precluding a correct evaluation of ascites, while subcutaneous CCl(4) causes an unwanted systemic inflammatory response.

Posttranscriptional changes of serum albumin: Clinical and prognostic significance in hospitalized patients with cirrhosis

Beside the regulation of fluid distribution, human serum albumin (HSA) carries other activities, such as binding, transport, and detoxification of many molecules. In patients with cirrhosis, HSA exhibits posttranscriptional alterations that likely affect its functions. This study aimed at identifying the structural HSA alterations occurring in cirrhosis and determining their relationship with specific clinical complications and patient survival. One hundred sixty‐eight patients with cirrhosis, 35 with stable conditions and 133 hospitalized for acute clinical complications, and 94 healthy controls were enrolled. Posttranscriptional HSA molecular changes were identified and quantified by using a high‐performance liquid chromatography/electrospray ionization mass spectrometry technique. Clinical and biochemical parameters were also recorded and hospitalized patients were followed for up to 1 year. Seven HSA isoforms carrying one or more posttranscriptional changes were identified. Altered HSA isoforms were significantly more represented in patients than in healthy controls. Conversely, the native, unchanged HSA isoform was significantly reduced in cirrhosis. Native HSA and most altered isoforms correlated with both Child‐Pugh and Model for End‐Stage Liver Disease scores. In hospitalized patients, oxidized and N‐terminal truncated isoforms were independently associated with ascites, renal impairment, and bacterial infection. Finally, the native HSA and cysteinylated/N‐terminal truncated isoforms were predictors of 1‐year survival, with greater prognostic accuracy than total serum albumin concentration. Conclusions: Extensive posttranscriptional changes of HSA, involving several molecular sites and increasing in parallel with disease severity, occur in patients with cirrhosis. Altered isoforms are independently associated with specific clinical complications, whereas the residual, native HSA isoform independently predicts patient survival. These findings support the concept of the “effective albumin concentration,” which implies that the global HSA function is related not only to its serum concentration, but also to the preservation of its structural integrity. (Hepatology 2014;60:1850–1859)

Reversal of liver fibrosis by the antagonism of endocannabinoid CB1 receptor in a rat model of CCl(4)-induced advanced cirrhosis.

The endocannabinoid system is involved in the pathogenesis of liver fibrosis. Although many substances have been proved to reduce fibrosis in experimental models of chronic liver injury, most of them appear to be effective only if given as a prophylactic or early treatment. This study aimed to explore the effect of pharmacological antagonism of the endocannabinoid cannabinoid type 1 (CB1) receptor started after the stage of full-blown cirrhosis had been reached. Wistar-Han rats with carbon tetrachloride (CCl4)-induced cirrhosis were randomized to receive the CB1 receptor antagonist Rimonabant (10 mg/kg/day) or the vehicle for 2 weeks. Age-matched healthy rats served as controls. Liver fibrosis was assessed using Sirius red staining, hydroxyproline concentration and α-smooth muscle actin expression. Hepatic gene expression of mediators of fibrogenesis and inflammation were evaluated by real-time PCR. We also assessed the hepatic expression of CB1 and CB2 receptors and that of the enzymes implicated in the endocannabinoid metabolism. Fibrosis was significantly reduced in rats treated with Rimonabant compared with rats receiving the vehicle. CB1 receptor antagonism limited the gene upregulation of fibrogenic and inflammatory mediators occurring in untreated cirrhotic rats. CB1 and CB2 receptor expression was increased in cirrhotic animals. Interestingly, pharmacological CB1 receptor antagonism was associated with a further induction of the CB2 receptor expression. Regression of fibrosis can be achieved by pharmacological blockade of the CB1 receptor even when started in an advanced stage of the disease. This effect is associated with the suppression of pro-fibrogenic and inflammatory mediators and may have been indirectly favoured by the induction of CB2 receptor expression.

The endocannabinoid system in advanced liver cirrhosis: pathophysiological implication and future perspectives

Endogenous cannabinoids (EC) are ubiquitous lipid signalling molecules providing different central and peripheral effects that are mediated mostly by the specific receptors CB1 and CB2. The EC system is highly upregulated during chronic liver disease and consistent experimental and clinical findings indicate that it plays a role in the pathogenesis of liver fibrosis and fatty liver disease associated with obesity, alcohol abuse and hepatitis C. Furthermore, a considerable number of studies have shown that EC and their receptors contribute to the pathogenesis of the cardio‐circulatory disturbances occurring in advanced cirrhosis, such as portal hypertension, hyperdynamic circulatory syndrome and cirrhotic cardiomyopathy. More recently, the EC system has been implicated in the development of ascites, hepatic encephalopathy and the inflammatory response related to bacterial infection. Rimonabant, a selective CB1 antagonist, was the first drug acting on the EC system approved for the treatment of obesity. Unfortunately, it has been withdrawn from the market because of its neuropsychiatric side effects. Compounds able to target selectively the peripheral CB1 receptors are under evaluation. In addition, molecules stimulating CB2 receptor or modulating the activity of enzymes implicated in EC metabolism are promising areas of pharmacological research. Liver cirrhosis and the related complications represent an important target for the clinical application of these compounds.

Mass spectrometric characterization of human serum albumin dimer: A new potential biomarker in chronic liver diseases.

Human serum albumin (HSA) undergoes several structural alterations affecting its properties in pro-oxidant and pro-inflammatory environments, as it occurs during liver cirrhosis. These modifications include the formation of albumin dimers. Although HSA dimers were reported to be an oxidative stress biomarker, to date nothing is known about their role in liver cirrhosis and related complications. Additionally, no high sensitive analytical method was available for HSA dimers assessment in clinical settings. Thus the HSA dimeric form in human plasma was characterized by mass spectrometry using liquid chromatography tandem mass spectrometry (LC-ESI-Q-TOF) and matrix assisted laser desorption time of flight (MALDI-TOF) techniques. N-terminal and C-terminal truncated HSA, as well as the native HSA, undergo dimerization by binding another HSA molecule. This study demonstrated the presence of both homo- and hetero-dimeric forms of HSA. The dimerization site was proved to be at Cys-34, forming a disulphide bridge between two albumin molecules, as determined by LC-MS analysis after tryptic digestion. Interestingly, when plasma samples from cirrhotic subjects were analysed, the dimer/monomer ratio resulted significantly increased when compared to that of healthy subjects. These isoforms could represent promising biomarkers for liver disease. Additionally, this analytical approach leads to the relative quantification of the residual native HSA, with fully preserved structural integrity.

A Fast and Validated Mass Spectrometry Method for the Evaluation of Human Serum Albumin Structural Modifications in the Clinical Field

A relatively fast analytical method for the identification and quantification of the post-transcriptional changes (PTCs) occurring in circulating human serum albumin (HSA) was developed. HSA is the most abundant protein in plasma and it represents the main determinant of plasma oncotic pressure, thus being the main modulator of fluid distribution between body compartments. Cirrhotic patients have low levels of HSA. Moreover, recent studies have demonstrated that during liver cirrhosis HSA presents PTCs affecting its properties. The HSA isoforms derived from these modifications could represent promising biomarkers for liver disease. Human plasma samples were collected from a cirrhotic patient (CH) and from an aged-matched non-cirrhotic subject (CT), purified by reverse-phase chromatography and analysed by an electrospray ionization quadrupole time-of-flight (ESI-Q-ToF) spectrometer. The deconvoluted ESI mass spectra from healthy subjects were all characterized by peaks attributed to mercaptoalbumin, nitrosylated, cysteinylated, glycated and N-terminal truncated HSA isoforms. The relative abundance of each isoform was derived and transformed into a relative per cent amount and the results were compared to those obtained analysing HSA from a CH plasma. The method was validated in terms of intra-day and inter-day reproducibility, both for quantitative results and PTCs molecular weight determination. The optimized method resulted in being effective in disclosing changes in HSA isoforms relative abundance and then it could be used for the systematic screening of cirrhotic patients to identify promising new biomarkers for liver diseases.

In hepatocellular carcinoma miR-221 modulates sorafenib resistance through inhibition of caspase-3–mediated apoptosis

Purpose: The aberrant expression of miR-221 is a hallmark of human cancers, including hepatocellular carcinoma (HCC), and its involvement in drug resistance, together with a proved in vivo efficacy of anti-miR-221 molecules, strengthen its role as an attractive target candidate in the oncologic field. The discovery of biomarkers predicting the response to treatments represents a clinical challenge in the personalized treatment era. This study aimed to investigate the possible role of miR-221 as a circulating biomarker in HCC patients undergoing sorafenib treatment as well as to evaluate its contribution to sorafenib resistance in advanced HCC. Experimental Design: A chemically induced HCC rat model and a xenograft mouse model, together with HCC-derived cell lines were employed to analyze miR-221 modulation by Sorafenib treatment. Data from the functional analysis were validated in tissue samples from surgically resected HCCs. The variation of circulating miR-221 levels in relation to Sorafenib treatment were assayed in the animal models and in two independent cohorts of patients with advanced HCC. Results: MiR-221 over-expression was associated with Sorafenib resistance in two HCC animal models and caspase-3 was identified as its target gene, driving miR-221 anti-apoptotic activity following Sorafenib administration. Lower pre-treatment miR-221 serum levels were found in patients subsequently experiencing response to Sorafenib and an increase of circulating miR-221 at the two months assessment was observed in responder patients. Conclusions: MiR-221 might represent a candidate biomarker of likelihood of response to Sorafenib in HCC patients to be tested in future studies. Caspase-3 modulation by miR-221 participates to Sorafenib resistance. Clin Cancer Res; 23(14); 3953–65. ©2017 AACR.

Sexuality and Psychopathological Aspects in Premenopausal Women with Metabolic Syndrome

INTRODUCTION Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors that have been suggested to impact female sexual function. AIMS This study aims to assess the prevalence of female sexual dysfunction (FSD) in premenopausal women with MetS compared with healthy controls (HC). Psychopathological aspects and the relationship to FSD were also evaluated in both groups. METHODS Two hundred four premenopausal women, of whom 98 had diagnosis of MetS, were asked to complete the Female Sexual Function Index (FSFI), the Female Sexual Distress Scale (FSDS), and the Middlesex Hospital Questionnaire (MHQ). Routine laboratory tests and anthropometric measurements were routinely performed. MAIN OUTCOME MEASURES FSFI and FSDS questionnaires, prevalence of FSD, and MHQ scores. RESULTS In the MetS group compared with the HC group, we found: a lower global FSFI score (P=0.005), higher prevalence of pathological scores compared with HC group, and lower scores in the desire, arousal, lubrication, and orgasm domains. An inverse correlation between the FSFI score and the number of risk factors for MetS was detected. MetS women reported significantly higher total scores in the somatization and depression domains when compared with the HC group. The logistic regression showed that high triglycerides (odds ratio [OR] 3.097; 95% confidence interval [CI] 1.272-7.542; P=0.026) and somatization (OR 7.068; CI 95% 2.291-21.812; P=0.001) are independently associated with FSD in premenopausal women. CONCLUSIONS Our results indicate a higher prevalence of sexual dysfunction in MetS women. A number of risk factors for MetS are positively associated with FSD and higher triglycerides seem to be the strongest predictors of sexual dysfunction. Psychopathological dimensions such as somatization are strongly associated with sexual dysfunction.

Assessment of Sepsis-3 criteria and quick SOFA in patients with cirrhosis and bacterial infections

Introduction Patients with cirrhosis have a high risk of sepsis, which confers a poor prognosis. The systemic inflammatory response syndrome (SIRS) criteria have several limitations in cirrhosis. Recently, new criteria for sepsis (Sepsis-3) have been suggested in the general population (increase of Sequential Organ Failure Assessment (SOFA) ≥2 points from baseline). Outside the intensive care unit (ICU), the quick SOFA (qSOFA (at least two among alteration in mental status, systolic blood pressure ≤100 mm Hg or respiratory rate ≥22/min)) was suggested to screen for sepsis. These criteria have never been evaluated in patients with cirrhosis. The aim of the study was to assess the ability of Sepsis-3 criteria in predicting in-hospital mortality in patients with cirrhosis and bacterial/fungal infections. Methods 259 consecutive patients with cirrhosis and bacterial/fungal infections were prospectively included. Demographic, laboratory and microbiological data were collected at diagnosis of infection. Baseline SOFA was assessed using preadmission data. Patients were followed up until death, liver transplantation or discharge. Findings were externally validated (197 patients). Results Sepsis-3 and qSOFA had significantly greater discrimination for in-hospital mortality (area under the receiver operating characteristic (AUROC)=0.784 and 0.732, respectively) than SIRS (AUROC=0.606) (p<0.01 for both). Similar results were observed in the validation cohort. Sepsis-3 (subdistribution HR (sHR)=5.47; p=0.006), qSOFA (sHR=1.99; p=0.020), Chronic Liver Failure Consortium Acute Decompensation score (sHR=1.05; p=0.001) and C reactive protein (sHR=1.01;p=0.034) were found to be independent predictors of in-hospital mortality. Patients with Sepsis-3 had higher incidence of acute-on-chronic liver failure, septic shock and transfer to ICU than those without Sepsis-3. Conclusions Sepsis-3 criteria are more accurate than SIRS criteria in predicting the severity of infections in patients with cirrhosis. qSOFA is a useful bedside tool to assess risk for worse outcomes in these patients. Patients with Sepsis-3 and positive qSOFA deserve more intensive management and strict surveillance.

Changes in Vaginal Physiology of Menopausal Women with Type 2 Diabetes

INTRODUCTION Metabolic disorders, such as type 2 diabetes, have been associated with an increased risk of development of female sexual dysfunction (FSD). In experimental studies, vascular, neuronal, and hormonal responsiveness alteration at vaginal level were proposed as contributors to the onset of FSD in women with diabetes; however, conclusive data on humans are still lacking. AIMS The study aimed to assess changes in vascularization, sex steroid receptors, nitric oxide synthase, and aquaporin-2 (AQP2) expression occurring at vaginal level in women with diabetes. METHODS Vaginal biopsies were obtained from 21 postmenopausal women, 10 of whom were diagnosed as having type 2 diabetes mellitus. CD31, estrogen receptor-α (ERα) and androgen receptor (AR) expression and localization were analyzed by immunostaining. Expression of endothelial (eNOS) and neuronal (nNOS) nitric oxide synthase isoforms and AQP2 were also assessed in vaginal samples. MAIN OUTCOMES MEASURES Changes in vaginal vascularization, sex steroids receptor, eNOS, nNOS and AQP2 expression. RESULTS Vaginal samples from women with diabetes showed an increased microvessel density in the lamina propria, which were morphologically disrupted suggesting an angiogenic compensatory mechanism. While no differences were seen in ERα, AR expression was significantly reduced in the vaginal epithelium and lamina propria of women with diabetes. Similarly, the gene and protein expressions of both nNOS and eNOS were significantly reduced in patients with diabetes, while AQP2 mRNAs level did not significantly differ between the two groups. CONCLUSION Diabetes greatly impacts vaginal physiology, being associated with alterations of the vaginal lamina propria vascular network, nitrergic signaling, and AR expression. These alterations may contribute to the increased risk of FSD development in women with diabetes.