SerpinB3 as hepatic marker of post-resective shear stress

Post-resective liver failure is a frequent complication of liver surgery and it is due to portal hyperperfusion of the remnant liver and to arterial vasoconstriction, as buffer response of the hepatic artery. In this context, splenectomy allows a reduction of portal flow and increases the survival chance in preclinical models. SerpinB3 is over-expressed in the liver in oxidative stress conditions, as a mechanism of cell defense to provide survival by apoptosis inhibition and cell proliferation. In this study, the expression of SerpinB3 was assessed as predictor of liver damage in in vivo models of major hepatic resection with or without splenectomy. Wistar male rats were divided into 4 groups: group A received 30% hepatic resection, group B > 60% resection, group C > 60% resection with splenectomy and group D sham-operated. Before and after surgery liver function tests, echo Doppler ultrasound and gene expression were assessed. Transaminase values and ammonium were significantly higher in groups that underwent major hepatic resection. Echo Doppler ultrasound showed the highest portal flow and resistance of the hepatic artery in the group with > 60% hepatectomy without splenectomy, while the association of splenectomy determined no increase in portal flow and hepatic artery resistance. Only the group of rats without splenectomy showed higher shear-stress conditions, reflected by higher levels of HO-1, Nox1 and of Serpinb3, the latter associated with an increase of IL-6. In conclusion, splenectomy controls inflammation and oxidative damage, preventing the expression of Serpinb3. Therefore, SerpinB3 can be considered as a marker of post-resective shear stress

Search of brain-enriched proteins in salivary extracellular vesicles for their use as mental disease biomarkers: A pilot study of the neuronal glycoprotein M6a

Background: Mental disorders affect millions of people worldwide. Their etiology is complex and the fact that the main effects occur in the brain hampers biochemical diagnosis. Therefore, biomarker finding in peripheral fluids such as serum or saliva is desirable. Here, we searched for biomarkers in salivary extracellular vesicles (EVs). Then, we focused on the protein M6a, related to neuronal connectivity and associated with several mood disorders to study its usefulness in saliva for the diagnosis of depression and anxiety. Methods: Biomarker candidates were searched by proteomic analysis of human salivary EVs. M6a presence in salivary EVs was validated by transmission electron microscopy and Western blot. M6a levels were measured by ELISA in saliva samples of 88 individuals classified as control, depressed or anxious. Results: We identified ten protein candidates in salivary EVs: OLIG2, PMP2, CNP, CAMK2A, SLC25A22, MLLT11, HTR2A, MAPT, ATP2B2 and M6a, all associated with emotional disorders. Salivary M6a levels positively correlated with the scores for the perceived stress scale in individuals diagnosed with depression. Furthermore, saliva samples of depressed patients treated with serotonin reuptake inhibitors (SSRI) or benzodiazepines differed in their M6a levels with respect to untreated patients. Limitations: The main limitation of this study lies in the low number of patients involved, which warrants replication. Conclusions: Salivary EVs contain promising biomarker candidates for mental disorders. Further studies will help validate them for their potential use in diagnosis. Our results lead us to propose M6a as a workable molecule to take into account as a possible stress biomarker.Fil: Monteleone, Melisa Carolina. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Billi, Silvia Cristina. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Viale, Luciano. Gobierno de la Provincia de Buenos Aires. Hospital Interzonal Especializado de Agudos y Cronicos San Juan de Dios.; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Catoira, Natalia P.. Gobierno de la Provincia de Buenos Aires. Hospital Interzonal Especializado de Agudos y Cronicos San Juan de Dios.; ArgentinaFil: Frasch, Alberto Carlos C.. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Brocco, Marcela Adriana. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; Argentin

M6 Membrane Protein Plays an Essential Role in Drosophila Oogenesis

We had previously shown that the transmembrane glycoprotein M6a, a member of the proteolipid protein (PLP) family, regulates neurite/filopodium outgrowth, hence, M6a might be involved in neuronal remodeling and differentiation. In this work we focused on M6, the only PLP family member present in Drosophila, and ortholog to M6a. Unexpectedly, we found that decreased expression of M6 leads to female sterility. M6 is expressed in the membrane of the follicular epithelium in ovarioles throughout oogenesis. Phenotypes triggered by M6 downregulation in hypomorphic mutants included egg collapse and egg permeability, thus suggesting M6 involvement in eggshell biosynthesis. In addition, RNAi-mediated M6 knockdown targeted specifically to follicle cells induced an arrest of egg chamber development, revealing that M6 is essential in oogenesis. Interestingly, M6-associated phenotypes evidenced abnormal changes of the follicle cell shape and disrupted follicular epithelium in mid- and late-stage egg chambers. Therefore, we propose that M6 plays a role in follicular epithelium maintenance involving membrane cell remodeling during oogenesis in Drosophila

Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P < 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P < 0.001), sNox2-dp (r(s), -0.57; P < 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P < 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation

Neural glycoprotein M6a is released in extracellular vesicles and modulated by chronic stressors in blood

Abstract Membrane neuronal glycoprotein M6a is highly expressed in the brain and contributes to neural plasticity promoting neurite growth and spine and synapse formation. We have previously showed that chronic stressors alter hippocampal M6a mRNA levels in rodents and tree shrews. We now show that M6a glycoprotein can be detected in mouse blood. M6a is a transmembrane glycoprotein and, as such, unlikely to be free in blood. Here we demonstrate that, in blood, M6a is transported in extracellular vesicles (EVs). It is also shown that M6a-containing EVs are delivered from cultured primary neurons as well as from M6a-transfected COS-7 cells. Released EVs containing M6a can be incorporated into COS-7 cells changing its phenotype through formation of membrane protrusions. Thus, M6a-containing EVs might contribute to maintain cellular plasticity. M6a presence in blood was used to monitor stress effects. Chronic restraint stress modulated M6a protein level in a sex dependent manner. Analysis of individual animals indicated that M6a level variations depend on the stressor applied. The response to stressors in blood makes M6a amenable to further studies in the stress disorder field

Arachidonic acid metabolites and endothelial dysfunction of portal hypertension

Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial growth factor (VEGF) inside the liver and in the portal circulation. Pharmacological manipulation of AA metabolites may be beneficial for cirrhotic portal hypertension

Characterization of a murine model of cardiorenal syndrome type 1 by high-resolution Doppler sonography

ABSTRACT: Cardiorenal syndrome type 1 (CRS-1) is the acute kidney disfunction caused by an acute worsening of cardiac function. CRS-1 is the consequence of renal vasoconstriction secondary to renin-angiotensin system (RAS) activation. No animal models of CRS-1 are described in literature. PURPOSE: To characterize a murine model of CRS-1 by using a high-resolution ultrasound echo-color Doppler system (VEVO2100). MATERIALS: Post-ischemic heart failure was induced by coronary artery ligation (LAD) in seven CD1 mice. Fifteen and thirty days after surgery, mice underwent cardiac and renal echo-color Doppler. Serum creatinine and plasma renin activity were measured after killing. Animals were compared to seven CD1 control mice. RESULTS: Heart failure with left ventricle dilatation (end diastolic area, p < 0.05 vs. controls) and significantly reduced ejection fraction (EF; p < 0.01 vs. controls) was evident 15 days after LAD. We measured a significant renal vasoconstriction in infarcted mice characterized by increased renal pulsatility index (PI; p < 0.05 vs. controls) associated to increased creatinine and renin levels (p < 0.05 vs. controls). CONCLUSIONS: The mice model of LAD is a good model of CRS-1 evaluable by Doppler sonography and characterized by renal vasoconstriction due to the activation of the renin-angiotensin system secondary to heart failure