1,721,013 research outputs found
Characterization of molecular pathways involved in acute and acute-on-chronic liver disease
Full text linkIntroduction: Acute decompensation was defined as the acute development of one or more major complications of liver disease and it was the main cause of hospitalization in patients with cirrhosis. The acute-on-chronic liver failure (ACLF) was characterized by acute decompensation of cirrhosis, organ failure and high 28-day mortality. ACLF displayed key features of systemic inflammation and its poor outcome was closely associated with exacerbated systemic inflammatory responses. Inflammasomes were multiprotein complexes which proteolytically activates the cytokines IL-1β and IL-18. These substrates might have an effect on the development of liver disease. Extracellular vesicles (EVs) were involved in many important biological processes as well as in disease pathogenesis. The dynamics of EVs secretion by different cell types and how the secreted EVs interact to advance the pathogenesis of liver disease were still unknown.
Aims: The aim of this study was to characterize the molecular pathways involved in acute decompensation of cirrhosis and ACLF through: the characterization of the inflammatory profile of patients, the in vitro evaluation of cytotoxic effects of plasma from patients on renal tubular cells, the expression of Inflammasome in these treated cells and in Peripheral Blood Mononuclear Cells (PBMC) of patients, the characterization of EVs from patients and the study of in vitro effects of isolated EVs in renal tubular cells.
Material and Methods: We enrolled patients with compensated cirrhosis, acute decompensation in cirrhosis, ACLF and healthy subjects as control population. Plasma levels of IL-6, IL-1β and IL-18 were detected by ELISA assay. Cytotoxic effects of plasma on renal tubular cells were assayed by annexin V and propidium iodide kit. Inflammasomes expression was detected both in renal tubular cells treated and in PBMC extracted from patients by Real Time PCR. Plasma EVs were extracted by ultracentrifugation and concentration was measured by Nanosight. Characterization of EVs was performed by FACS analysis. Cytotoxic effects of plasma EVs on renal tubular cells were assayed by XTT assay.
Results: Plasma levels of pro-inflammatory cytokines measure in the firsts patients enrolled did not differed between the groups of compensated cirrhosis, acute decompensation and ACLF. Also viability and death rate did not change in a way statistically significant in cell stimulated with plasma from the three groups of patients. Furthermore, Inflammasome gene expression in these cells did not underlines the activation of this protein complex. In PBMC from patients, gene expression of Tool-like receptor 2 (TLR-2) was significantly higher in patients with compensated cirrhosis compare to acute decompensation of cirrhosis (p=0.036). Albumin added to cell medium reduced cytotoxic effects of plasma on renal tubular cells. Plasma EVs of patients enrolled were more concentrated in ACLF groups compare to healthy subjects. EVs did not expressed selected platelets (CD41, CD42b) and monocyte markers (CD14) in their surface but they expressed marker of platelets activated endothelium (CD62E). The levels of CD62E were significantly higher in patients with ACLF compare to healthy subjects and patients with compensated cirrhosis (p=0.0041 and p=0.0111, respectively). CD40L levels were significantly higher in all patients' groups compare to healthy subjects (p<0.02). Plasma EVs from patients with acute and acute-on-chronic liver failure exerted a higher cytotoxic effects compare to healthy subjects and patients with compensated cirrhosis on renal tubular cells (p<0.0001). Cells incubated with EVs from acute and acute-on-chronic liver failure underwent to apoptosis (p<0.0001), to ROS production (p<0.0001), to lose albumin intake capabilities (p<0.0001) and reduction of Zonula Occludens-1 (ZO-1) expression (p=0.0166) compare to healthy subjects and patients with compensated cirrhosis. Instead, megalin and PGC1α expression did not change.
Conclusions: The role of EVs in decompensated cirrhosis and ACLF need to be invastigated and study their hypothetic role as vehicle of mediator of extrahepatic organ injury and complications of cirrhosis
Endotoxin Effects on Cardiac and Renal Functions and Cardiorenal Syndromes
No full textGram-negative sepsis is a major cause of morbidity and mortality in critical ill patients. Recent findings in molecular biology and in signaling pathways have enhanced our understanding of its pathogenesis and opened up opportunities of innovative therapeutic approaches. Endotoxin plays a pivotal role in the pathogenesis of multi-organ dysfunction in the setting of gram-negative sepsis. Indeed, heart and kidney impairments seem to be induced by the release of circulating pro-inflammatory and pro-apoptotic mediators triggered by endotoxin interaction with immune cells. These molecules are responsible for cellular apoptosis, autophagy, cell cycle arrest, and microRNAs activation. Therefore, the early identification of sepsis-associated acute kidney injury and heart dysfunction may improve the patient clinical outcome. In this report, we will consider the role of endotoxin in the pathogenesis of sepsis, its effects on both cardiac and renal functions, and the interactions between these 2 systems in the setting of cardiorenal syndromes (CRS), particularly in CRS type 5. Finally, we will discuss the possible role of extracorporeal therapies in reducing endotoxin levels.</jats:p
The Role of Endotoxin in the Setting of Cardiorenal Syndrome Type 5
No full textLipopolysaccharide or endotoxin, the major cell wall component of gram-negative bacteria, plays a pivotal role in the pathogenesis of sepsis. It is able to activate the host defense system through the interaction with Toll-like receptor 4, thus triggering pro-inflammatory mechanisms. When the production of inflammatory mediators becomes uncontrolled and excessive, septic shock develops with multiple organ dysfunction, such as myocardial and renal impairment, which are hallmarks of cardiorenal syndrome type 5. In this review, we will analyze the role of endotoxin in the pathogenesis of sepsis, its effects on cardiac and renal interactions in the setting of cardiorenal syndrome type 5 and the possible use of extracorporeal therapies in this clinical condition.</jats:p
Cytotoxic effects of p-cresol in renal epithelial tubular cells
Full text linkBACKGROUND:
The uremic syndrome is characterized by a deterioration of kidney function due to the accumulation of uremic toxins. Currently, 100 different uremic toxins have been identified. Uremic toxins are particularly difficult to remove by conventional dialysis treatments and are the major causes of mortality in patients with chronic kidney disease (CKD). p-Cresol is a well-known uremic toxin which accumulates in uremic serum. Our aim was to evaluate the in vitro effect of p-cresol on apoptosis and necrosis in renal tubular cells (RTCs) to better understand the pathophysiological effect of this toxin on the kidney.
METHODS:
We studied apoptosis and necrosis in RTCs, which were incubated for 24 h with increasing concentrations of p-cresol. A DNA ladder was noted in treated cells as a qualitative marker of the apoptotic process. Furthermore, we performed quantitative analysis of cell viability using a flow cytometer and assessed caspase-3 activity.
RESULTS:
Incubation with p-cresol for 24 h resulted in a significant reduction in RTC viability. DNA isolated from RTCs incubated with increasing p-cresol concentrations for 24 h showed a 'ladder' pattern of apoptosis at p-cresol concentrations of 10, 5 and 2.5 mg/l. However, we did not observe any significant changes in apoptosis levels detected by annexin V and caspase-3 compared with untreated cells. Cytofluorimetric analysis of necrosis highlighted significantly higher cell death rates in RTCs incubated with the higher p-cresol concentrations (range 40-10 mg/l) compared with other concentrations (5-2.5 mg/l) and untreated cells (p < 0.05). Necrosis induction was stronger at higher p-cresol concentrations.
CONCLUSION:
It is necessary to develop new therapeutic and dialytic strategies to manage p-cresol concentrations in CKD
A comparison of three commercial platforms for urinary NGAL in critically ill adults
Full text linkBackground: Early biomarkers for acute kidney injury (AKI) diagnosis are needed since an increase in serum creatinine levels is a late marker. Neutrophil gelatinase-associated lipocalin (NGAL) is one of the most promising AKI biomarkers. Prior to routine clinical use, it is necessary to evaluate and validate a high-throughput commercially available method for NGAL detection. The aim of this study was to do an independent validation and comparison of the analytical performance of three different commercially available urine NGAL (uNGAL) assays.
Methods: Urine samples (n=110) were obtained from various patient groups with and without AKI. All urine samples were processed using Architect NGAL assay, Siemens Advia® 2400 NGAL test, and Siemens Dimension Vista® NGAL TestTM, based on the three different platforms.
Results: Overall, there was good agreement among the three assays: Spearman’s rank correlation coefficient between Architect and Vista was 0.989 (95% confidence interval [CI], 0.983–0.993), between Architect and Advia, 0.962 (95% CI, 0.937–0.977), between Vista and Advia 2400, 0.975 (95% CI, 0.961–0.984). We observed a negative bias of Architect compared with the other assays: comparing Architect to Vista, the mean bias was –55.7 ng/mL (95% CI, –74.3 to –37.0 ng/mL); comparing Architect to Advia 2400, the mean bias was –40.9 ng/mL (95% CI, –56.4 to –25.4 ng/nL). The bias is proportional to the concentration of uNGAL and is more pronounced at higher levels, while irrelevant near the tested cutoff levels of 100 and 190 ng/mL. Comparing Vista and Advia 2400, the mean bias was 10.1 ng/mL (95% CI, 1.5–18.8 ng/mL). Intra-assay imprecision was generally acceptable across all assays; coefficient of variation ranged from 0.8% to 5.3%.
Conclusions: All three methods for uNGAL showed acceptable performance for the tested parameters and are comparable with each other at clinically relevant cutoffs. However, Architect yields lower results than the other two methods, with a bias more pronounced at higher uNGAL concentrations, suggesting additional standardization efforts will likely be necessary to better harmonize the uNGAL methods at various clinically relevant cutoffs
Cardiorenal syndrome type 1: A defective regulation of monocyte apoptosis induced by proinflammatory and proapoptotic factors
No full textMitochondria-targeted antioxidant mitoquinone attenuates liver inflammation and fibrosis in cirrhotic rats
Full text linkIn liver cirrhosis, oxidative stress plays a major role in promoting liver inflammation and fibrosis. Mitochondria dysregulation is responsible for excessive reactive oxygen species production. Therefore, in an experimental model of cirrhosis, we investigated the effect of mitochondria-targeted antioxidant mitoquinone
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