Modulation of faecal metagenome in Crohn's disease:Role of microRNAs as biomarkers

BACKGROUND The gut microbiota plays a key role in the maintenance of intestinal homeostasis and the development and activation of the host immune system. It has been shown that commensal bacterial species can regulate the expression of host genes. 16 S rRNA gene sequencing has shown that the microbiota in inflammatory bowel disease(IBD) is abnormal and characterized by reduced diversity. Micro RNAs(miRNAs) have been explored as biomarkers and therapeutic targets, since they are able to regulate specific genes associated with Crohn's disease(CD). In this work, we aim to investigate the composition of gut microbiota of active treatment-na?ve adult CD patients, with miRNA profile from gut microbiota.AIM To investigate the composition of gut microbiota of active treatment-na?ve adult CD patients, with miRNA profile from gut microbiota.METHODS Patients attending the outpatient clinics at Valme University Hospital without relevant co-morbidities were matched according to age and gender. Faecal samples of newonset CD patients, free of treatment, and healthy controls were collected. Faecal samples were homogenized, and DNA was amplified by PCR using primers directed to the 16 S bacterial rRNA gene. Pyrosequencing was performed using GS-Junior platform. For sequence analysis, MGRAST server with the database Ribosomal Project was used. MiRNA profile and their relative abundance were analyzed by quantitative PCR.RESULTS Microbial community was characterized using 16 S rRNA gene sequencing in 29 samples(n = 13 CD patients, and n = 16 healthy controls). The mean Shannon diversity was higher in the healthy control population compared to CD group(5.5 vs 3.7). A reduction in Firmicutes and an increase in Bacteroidetes were found. Clostridia class was also significantly reduced in CD. Principal components analysis showed a grouping pattern, identified in most of the subjects in both groups, showing a marked difference between control and CD groups. A functional metabolic study showed that a lower metabolism of carbohydrates(P = 0.000) was found in CD group, while the metabolism of lipids was increased. In CD patients, three miRNAs were induced in affected mucosa: mir-144(6.2 ± 1.3 fold), mir-519(21.8 ± 3.1) and mir-211(2.3 ± 0.4). CONCLUSION Changes in microbial function in active non-treated CD subjects and three miRNAs in affected vs non-affected mucosa have been found. miRNAs profile may serve as a biomarker.

Fibrinogen-thrombin collagen patch reinforcement of highrisk colonic anastomoses in rats

AIMTo evaluate the effectiveness of human fibrinogen-thrombin collagen patch (TachoSil®) in the reinforcement of high-risk colon anastomoses.METHODSA quasi-experimental study was conducted in Wistar rats (n = 56) that all underwent high-risk anastomoses (anastomosis with only two sutures) after colectomies. The rats were divided into two randomized groups: Control group (24 rats) and treatment group (24 rats). In the treatment group, high-risk anastomosis was reinforced with TachoSil® (a piece of TachoSil® was applied over this high-risk anastomosis, covering the gap). Leak incidence, overall survival, intra-abdominal adhesions, and histologic healing of anastomoses were analyzed. Survivors were divided into two subgroups and euthanized at 15 and 30 d after intervention in order to analyze the adhesions and histologic changes.RESULTSOverall survival was 71.4% and 57.14% in the TachoSil® group and control group, respectively (P = 0.29); four rats died from other causes and six rats in the treatment group and 10 in the control group experienced colonic leakage (P > 0.05). The intra-abdominal adhesion score was similar in both groups, with no differences between subgroups. We found non-significant differences in the healing process according to the histologic score used in both groups (P = 0.066).CONCLUSIONIn our study, the use of TachoSil® was associated with a non-statistically significant reduction in the rate of leakage in high-risk anastomoses. TachoSil® has been shown to be a safe product because it does not affect the histologic healing process or increase intra-abdominal adhesions.

Combination of squamous cell carcinoma antigen immunocomplex and alpha-fetoprotein in mid-and long-term prediction of hepatocellular carcinoma among cirrhotic patients

BACKGROUND The combination of alpha-fetoprotein(AFP)and squamous cell carcinoma antigen immunocomplex(SCCA-IgM)have been proposed for its use in the screening of hepatocellular carcinoma(HCC).Current screening programs for all cirrhotic patients are controversial and a personalized screening is an unmet need in the precision medicine era.AIM To determine the role of the combination of SCCA-IgM and AFP in predicting mid-and long-term appearance of HCC.METHODS Two-hundred and three cirrhotic patients(Child A 74.9%,B 21.2%,C 3.9%)were followed-up prospectively every six months to screen HCC by ultrasound and AFP according to European Association for the Study of the Liver guidelines.The estimation cohort was recruited in Italy(30.5%;62/203)and validation cohort from Spain(69.5%;141/203).Patients underwent to evaluate SCCA-IgM by enzyme-linked immunosorbent assay(Hepa-IC,Xeptagen,Italy)and AFP levels at baseline.Patients were followed-up for 60 mo,being censored at the time of the appearance of HCC.RESULTS There were 10.8%and 23.1%of HCC development at two-and five-years followup.Patients with HCC showed higher levels of SCCA-IgM than those without it(425.72±568.33 AU/mL vs 195.93±188.40 AU/mL,P=0.009)during the fiveyear follow-up.In multivariate analysis,after adjusting by age,sex,aspartate transaminase and Child-Pugh,the following factors were independently associated with HCC:SCCA-IgM[Hazard ratio(HR)=1.001,95%CI:1.000-1.002;P=0.003],AFP(HR=1.028,95%CI:1.009-1.046;P=0.003)and creatinine(HR=1.56495%CI:1.151-2.124;P=0.004).The log-rank test of the combination resulted in 7.488(P=0.024)in estimation cohort and 11.061(P=0.004)in the validation cohort,and a 100%of correctly classified rate identifying a low-risk group in both cohorts in the two-year follow-up.CONCLUSION We have constructed a predictive model based on the combination of SCCA-IgM and AFP that provides a new HCC screening method,which could be followed by tailored HCC surveillance for individual patients,especially for those cirrhotic patients belonging to the subgroup identified as low-risk of HCC development.

Targeting galectin-3 to counteract spike-phase uncoupling of fast-spiking interneurons to gamma oscillations in Alzheimer’s disease

Background Alzheimer’s disease(AD)is a progressive multifaceted neurodegenerative disorder for which no disease-modifying treatment exists.Neuroinflammation is central to the pathology progression,with evidence suggesting that microglia-released galectin-3(gal3)plays a pivotal role by amplifying neuroinflammation in AD.However,the possible involvement of gal3 in the disruption of neuronal network oscillations typical of AD remains unknown.Methods Here,we investigated the functional implications of gal3 signaling on experimentally induced gamma oscillations ex vivo(20-80 Hz)by performing electrophysiological recordings in the hippocampal CA3 area of wild-type(WT)mice and of the 5×FAD mouse model of AD.In addition,the recorded slices from WT mice under acute gal3 application were analyzed with RT-qPCR to detect expression of some neuroinflammation-related genes,and amyloid-β(Aβ)plaque load was quantified by immunostaining in the CA3 area of 6-month-old 5×FAD mice with or without Gal3 knockout(KO).Results Gal3 application decreased gamma oscillation power and rhythmicity in an activity-dependent manner,which was accompanied by impairment of cellular dynamics in fast-spiking interneurons(FSNs)and pyramidal cells.We found that the gal3-induced disruption was mediated by the gal3 carbohydrate-recognition domain and prevented by the gal3 inhibitor TD139,which also prevented Aβ42-induced degradation of gamma oscillations.Further-more,the 5×FAD mice lacking gal3(5×FAD-Gal3KO)exhibited WT-like gamma network dynamics and decreased Aβplaque load.Conclusions We report for the first time that gal3 impairs neuronal network dynamics by spike-phase uncoupling of FSNs,inducing a network performance collapse.Moreover,our findings suggest gal3 inhibition as a potential therapeutic strategy to counteract the neuronal network instability typical of AD and other neurological disorders encompassing neuroinflammation and cognitive decline.

An international Delphi consensus statement on metabolic dysfunction-associated fatty liver disease and risk of chronic kidney disease

Background:With the rising global prevalence of fatty liver disease related to metabolic dysfunction,the association of this common liver condition with chronic kidney disease(CKD)has become increasingly evident.In 2020,the more inclusive term metabolic dysfunction-associated fatty liver disease(MAFLD)was proposed to replace the term non-alcoholic fatty liver disease(NAFLD).The observed association between MAFLD and CKD and our understanding that CKD can be a consequence of underlying metabolic dysfunction support the notion that individuals with MAFLD are at higher risk of having and developing CKD compared with those without MAFLD.However,to date,there is no appropriate guidance on CKD in individuals with MAFLD.Furthermore,there has been little attention paid to the link between MAFLD and CKD in the Nephrology community.Methods and Results:Using a Delphi-based approach,a multidisciplinary panel of 50 international experts from 26 countries reached a consensus on some of the open research questions regarding the link between MAFLD and CKD.Conclusions:This Delphi-based consensus statement provided guidance on the epidemiology,mechanisms,management and treatment of MAFLD and CKD,as well as the relationship between the severity of MAFLD and risk of CKD,which establish a framework for the early prevention and management of these two common and interconnected diseases.

Translational pancreatic cancer research:a comparative study on patient-derived xenograft models

AIM To assess the viability of orthotopic and heterotopic patient-derived pancreatic cancer xenografts implanted into nude mice.METHODS This study presents a prospective experimental analytical follow-up of the development of tumours in mice upon implantation of human pancreatic adenocarcinoma samples. Specimens were obtained surgically from patients with a pathological diagnosis of pancreatic adenocarcinoma. Tumour samples from pancreatic cancer patients were transplanted into nude mice in three different locations(intraperitoneal, subcutaneous and pancreatic). Histological analysis(haematoxylin-eosin and Masson's trichrome staining) and immunohistochemical assessment of apoptosis(TUNEL), proliferation(Ki-67), angiogenesis(CD31) and fibrogenesis(α-SMA) were performed. When a tumour xenograft reached the target size, it was reimplanted in a new nude mouse. Three sequential tumour xenograft generations were generated(F1, F2 and F3).RESULTS The overall tumour engraftment rate was 61.1%. The subcutaneous model was most effective in terms of tissue growth(69.9%), followed by intraperitoneal(57.6%) and pancreatic(55%) models. Tumour development was faster in the subcutaneous model(17.7 ± 2.6 wk) compared with the pancreatic(23.1 ± 2.3 wk) and intraperitoneal(25.0 ± 2.7 wk) models(P = 0.064). There was a progressive increase in the tumour engraftment rate over successive generations for all three models(F1 28.1% vs F2 71.4% vs F3 80.9%, P < 0.001). There were no significant differences in tumour xenograft differentiation and cell proliferation between human samples and the three experimental models among the sequential generations of tumour xenografts. However, a progressive decrease in fibrosis, fibrogenesis, tumour vascularisation and apoptosis was observed in the three experimental models compared with the human samples. All three pancreatic patient-derived xenograft models presented similar histological and immunohistochemical characteristics.CONCLUSION In our experience, the faster development andgreatest number of viable xenografts could make the subcutaneous model the best option for experimentation in pancreatic cancer.

Drug repurposing for COVID-19 using machine learning and mechanistic models of signal transduction circuits related to SARS-CoV-2 infection

Dear Editor,Drug repurposing is a convenient alternative when the need for new drugs in an unexpected medical scenario is urgent,as is the case of emerging pathogens.In recent years,approaches based on network biology have demonstrated to be superior to genecentric ones.1 Here,we use an innovative methodology that combines mechanistic modeling of the signal transduction circuits related to SARS-CoV-2 infection(the COVID-19 disease map)with a machine-learning algorithm that learns potential causal interactions between proteins,already targets of drugs,and specific signaling circuits in the COVID-19 disease map,to suggest potentially repurposable drugs.

Drug repurposing for COVID-19 using machine learning and mechanistic models of signal transduction circuits related to SARS-CoV-2 infection

Dear Editor,Drug repurposing is a convenient alternative when the need for new drugs in an unexpected medical scenario is urgent,as is the case of emerging pathogens.In recent years,approaches based on network biology have demonstrated to be superior to genecentric ones.1 Here,we use an innovative methodology that combines mechanistic modeling of the signal transduction circuits related to SARS-CoV-2 infection(the COVID-19 disease map)with a machine-learning algorithm that learns potential causal interactions between proteins,already targets of drugs,and specific signaling circuits in the COVID-19 disease map,to suggest potentially repurposable drugs.

Pneumococcal disease in adult solid organ transplantation recipients

In solid organ transplant(SOT) recipients, Streptococcus pneumoniae can cause substantial morbidityand mortality ranging from non-invasive to invasive diseases, including pneumonia, bacteremia, and meningitis, with a risk of invasive pneumococcal disease 12 times higher than that observed in non-immunocompromised patients. Moreover, pneumococcal infection has been related to graft dysfunction. Several factors have been involved in the risk of pneumococcal disease in SOT recipients, such as type of transplant, time since transplantation, influenza activity, and nasopharyngeal colonization. Pneumococcal vaccination is recommended for all SOT recipients with 23-valent pneumococcal polysaccharides vaccine. Although immunological rate response is appropriate, it is lower than in the rest of the population, decreases with time, and its clinical efficacy is variable. Booster strategy with 7-valent pneumococcal conjugate vaccine has not shown benefit in this population. Despite its relevance, there are few studies focused on invasive pneumococcal disease in SOT recipients. Further studies addressing clinical, microbiological, and epidemiological data of pneumococcal disease in the transplant setting as well as new strategies for improving the protection of SOT recipients are warranted.

Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

Severe Acute Respiratory Syndrome Coronavirus(SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components.Dendritic cells(DCs)play a key role in the defense against viral infections,for instance plasmacytoid DCs(pDCs),have the capacity to produce vast amounts of interferon-alpha(IFN-α).In COVID-19 there is a deficit in DC numbers and IFN-αproduction,which has been associated with disease severity.In this work,we described that in addition to the DC deficiency,several DC activation and homing markers were altered in acute COVID-19 patients,which were associated with multiple inflammatory markers.Remarkably,previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+myeloid DCs and pDCs seven months after SARS-CoV-2 infection.Moreover,the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients,while no restoration of integrinβ7 and indoleamine 2,3-dyoxigenase(IDO)levels were observed.These findings contribute to a better understanding of the immunological sequelae of COVID-19.

What Has the COVID-19 Pandemic Taught Us so Far?Addressing the Problem from a Hepatologist's Perspective

As of today, March 30, 2020, when this Editorial is being written, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), causal agent of the coronavirus disease (COVID-19) has been confirmed in more than 745,000 cases worldwide and has claimed the lives of more than 35,000 people.1 In addition to the morbidity and mortality associated with COVID-19, this betacoronavirus has placed several of the world's major economies in strife, mainly in Western Europe and North America, paralyzing travel and regular social interactions, making COVID-19 undoubtedly one of the most important pandemics in human history.