324 research outputs found

    До мінералогії сезонних сульфатів мису Фіолент (Південно-Західний Крим)

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    Комплексом методів вивчено колекцію зразків вторинних мінералів одного з узбережних відслонень зони окиснення сульфідної мінералізації мису Фіолент (Південно-Західний Крим). Установлено, що всі досліджені зразки є полімінеральними утвореннями, в яких одночасно співіснують у різних пропорціях сульфати Mg, Al, Fe²⁺, Fe³⁺, Ca тощо: пікерингіт (найпоширеніший), пікерингіт залізистий, гексагідрит, старкіїт, епсоміт, алуноген, ботріоген, копіапіт, ярозит, гіпс та ін. Старкіїт і ботріоген у Криму виявлено вперше.The collection of secondary minerals from one of littoral occurrences of sulphide zone of oxidation of the Fiolent Cape (South-Western Crimea) is studied by different methods. It was established that all studied samples were polymineral formations which consisted of sulphates of Mg, Al, Fe²⁺, Fe³⁺, Ca, etc. in different proportions: pickeringite (the most wide-spread), ferropickeringite, hexahydrite, starkeyite, epsomite, alunogen, botryogen, copiapite, jarosite, gypsum etc. Starkeyite and botryogen are detected in the Crimea for the first time

    Rapid hepatic clearance of full length CCN-2/CTGF: a putative role for LRP1-mediated endocytosis

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    CCN-2 (connective tissue growth factor; CTGF) is a key factor in fibrosis. Plasma CCN-2 has biomarker potential in numerous fibrotic disorders, but it is unknown which pathophysiological factors determine plasma CCN-2 levels. The proteolytic amino-terminal fragment of CCN-2 is primarily eliminated by the kidney. Here, we investigated elimination and distribution profiles of full length CCN-2 by intravenous administration of recombinant CCN-2 to rodents. After bolus injection in mice, we observed a large initial distribution volume (454 mL/kg) and a fast initial clearance (120 mL/kg/min). Immunosorbent assay and immunostaining showed that CCN-2 distributed mainly to the liver and was taken up by hepatocytes. Steady state clearance in rats, determined by continuous infusion of CCN-2, was fast (45 mL/kg/min). Renal CCN-2 clearance, determined by arterial and renal vein sampling, accounted for only 12 % of total clearance. Co-infusion of CCN-2 with receptor-associated protein (RAP), an antagonist of LDL-receptor family proteins, showed that RAP prolonged CCN-2 half-life and completely prevented CCN-2 internalization by hepatocytes. This suggests that hepatic uptake of CCN-2 is mediated by a RAP-sensitive mechanism most likely involving LRP1, a member of the LDL-receptor family involved in hepatic clearance of various plasma proteins. Surface plasmon resonance binding studies confirmed that CCN-2 is an LRP1 ligand. Co-infusion of CCN-2 with an excess of the heparan sulphate-binding protamine lowered the large initial distribution volume of CCN-2 by 88 % and reduced interstitial staining of CCN-2, suggesting binding of CCN-2 to heparan sulphate proteoglycans (HSPGs). Protamine did not affect clearance rate, indicating that RAP-sensitive clearance of CCN-2 is HSPG independent. In conclusion, unlike its amino-terminal fragment which is cleared by the kidney, fu

    Титульні сторінки та зміст

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    Kidney injury triggers fibrosis, the final common pathway of chronic kidney disease (CKD). The increase of CKD prevalence worldwide urgently calls for new therapies. Available systemic treatment such as rapamycin are associated with serious side effects. To study the potential of local antifibrotic therapy, we administered rapamycin-loaded microspheres under the kidney capsule of ureter-obstructed rats and assessed the local antifibrotic effects and systemic side effects of rapamycin. After 7 days, microsphere depots were easily identifiable under the kidney capsule. Both systemic and local rapamycin treatment reduced intrarenal mTOR activity, myofibroblast accumulation, expression of fibrotic genes, and T-lymphocyte infiltration. Upon local treatment, inhibition of mTOR activity and reduction of myofibroblast accumulation were limited to the immediate vicinity of the subcapsular pocket, while reduction of T-cell infiltration was widespread. In contrast to systemically administered rapamycin, local treatment did not induce off target effects such as weight loss. Thus subcapsular delivery of rapamycin-loaded microspheres successfully inhibited local fibrotic response in UUO with less systemic effects. Therapeutic effect of released rapamycin was most prominent in close vicinity to the implanted microspheres. (C) 2014 Elsevier Ltd. All rights reserved

    Rapid hepatic clearance of full length CCN-2/CTGF: a putative role for LRP1-mediated endocytosis

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    This is the final version. Available on open access from Springer via the DOI in this record.CCN-2 (connective tissue growth factor; CTGF) is a key factor in fibrosis. Plasma CCN-2 has biomarker potential in numerous fibrotic disorders, but it is unknown which pathophysiological factors determine plasma CCN-2 levels. The proteolytic amino-terminal fragment of CCN-2 is primarily eliminated by the kidney. Here, we investigated elimination and distribution profiles of full length CCN-2 by intravenous administration of recombinant CCN-2 to rodents. After bolus injection in mice, we observed a large initial distribution volume (454 mL/kg) and a fast initial clearance (120 mL/kg/min). Immunosorbent assay and immunostaining showed that CCN-2 distributed mainly to the liver and was taken up by hepatocytes. Steady state clearance in rats, determined by continuous infusion of CCN-2, was fast (45 mL/kg/min). Renal CCN-2 clearance, determined by arterial and renal vein sampling, accounted for only 12 % of total clearance. Co-infusion of CCN-2 with receptor-associated protein (RAP), an antagonist of LDL-receptor family proteins, showed that RAP prolonged CCN-2 half-life and completely prevented CCN-2 internalization by hepatocytes. This suggests that hepatic uptake of CCN-2 is mediated by a RAP-sensitive mechanism most likely involving LRP1, a member of the LDL-receptor family involved in hepatic clearance of various plasma proteins. Surface plasmon resonance binding studies confirmed that CCN-2 is an LRP1 ligand. Co-infusion of CCN-2 with an excess of the heparan sulphate-binding protamine lowered the large initial distribution volume of CCN-2 by 88 % and reduced interstitial staining of CCN-2, suggesting binding of CCN-2 to heparan sulphate proteoglycans (HSPGs). Protamine did not affect clearance rate, indicating that RAP-sensitive clearance of CCN-2 is HSPG independent. In conclusion, unlike its amino-terminal fragment which is cleared by the kidney, full length CCN-2 is primarily eliminated by the liver via a fast RAP-sensitive, probably LRP1-dependent pathway.FibroGen, Inc

    P62-positive aggregates are homogenously distributed in the myocardium and associated with the type of mutation in genetic cardiomyopathy

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    © 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd Genetic cardiomyopathy is caused by mutations in various genes. The accumulation of potentially proteotoxic mutant protein aggregates due to insufficient autophagy is a possible mechanism of disease development. The objective of this study was to investigate the distribution in the myocardium of such aggregates in relation to specific pathogenic genetic mutations in cardiomyopathy hearts. Hearts from 32 genetic cardiomyopathy patients, 4 non-genetic cardiomyopathy patients and 5 controls were studied. Microscopic slices from an entire midventricular heart slice were stained for p62 (sequestosome-1, marker for aggregated proteins destined for autophagy). The percentage of cardiomyocytes with p62 accumulation was higher in cardiomyopathy hearts (median 3.3%) than in healthy controls (0.3%; P <.0001). p62 accumulation was highest in the desmin (15.6%) and phospholamban (7.2%) groups. P62 accumulation was homogeneously distributed in the myocardium. Fibrosis was not associated with p62 accumulation in subgroup analysis of phospholamban hearts. In conclusion, accumulation of p62-positive protein aggregates is homogeneously distributed in the myocardium independently of fibrosis distribution and associated with desmin and phospholamban cardiomyopathy. Proteotoxic protein accumulation is a diffuse process in the myocardium while a more localized second hit, such as local strain during exercise, might determine whether this leads to regional myocyte decay

    Interplay between extracellular matrix components and cellular and molecular mechanisms in kidney fibrosis

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    Chronic kidney disease (CKD) is characterized by pathological accumulation of extracellular matrix (ECM) proteins in renal structures. Tubulointerstitial fibrosis is observed in glomerular diseases as well as in the regeneration failure of acute kidney injury (AKI). Therefore, finding antifibrotic therapies comprises an intensive research field in Nephrology. Nowadays, ECM is not only considered as a cellular scaffold, but also exerts important cellular functions. In this review, we describe the cellular and molecular mechanisms involved in kidney fibrosis, paying particular attention to ECM components, profibrotic factors and cell-matrix interactions. In response to kidney damage, activation of glomerular and/or tubular cells may induce aberrant phenotypes characterized by overproduction of proinflammatory and profibrotic factors, and thus contribute to CKD progression. Among ECM components, matricellular proteins can regulate cell-ECM interactions, as well as cellular phenotype changes. Regarding kidney fibrosis, one of the most studied matricellular proteins is cellular communication network-2 (CCN2), also called connective tissue growth factor (CTGF), currently considered as a fibrotic marker and a potential therapeutic target. Integrins connect the ECM proteins to the actin cytoskeleton and several downstream signaling pathways that enable cells to respond to external stimuli in a coordinated manner and maintain optimal tissue stiffness. In kidney fibrosis, there is an increase in ECM deposition, lower ECM degradation and ECM proteins cross-linking, leading to an alteration in the tissue mechanical properties and their responses to injurious stimuli. A better understanding of these complex cellular and molecular events could help us to improve the antifibrotic therapies for CKD

    Dermal cellular senescence and EndMT in patients with systemic sclerosis undergoing cyclophosphamide or aHSCT treatment

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    ObjectivesCellular senescence and endothelial-to-mesenchymal transition (EndMT) are profibrotic cellular processes involved in systemic sclerosis (SSc), but how they respond to treatment is largely unknown.MethodsSkin biopsies from diffuse cutaneous SSc (dcSSc) patients who underwent either autologous haematopoietic stem cell transplantation (aHSCT) or cyclophosphamide pulse (iv CYC) treatment were collected before and 6 months after randomization in the Autologous Stem Cell Transplantation International Scleroderma trial. The extent of fibrosis, inflammation, senescence, EndMT and tissue remodelling were examined in histopathology.ResultsFourteen pairs of skin biopsies were analysed. Decrease in modified Rodnan skin score was more pronounced in aHSCT-treated patients compared with iv CYC at 6 months (median change −14 [IQR −16 to −9] vs -6 [IQR −9 to −4], respectively, P = 0.028). Histologically, expression of urokinase-type plasminogen activator receptor (uPAR) on fibroblasts, P21 on vessels and EndMT decreased after treatment in both groups, yet the reduction was more pronounced in the aHSCT group. Poor skin response was associated with high baseline connective tissue growth factor (CTGF) on fibroblasts and low baseline P21 on vessels, with an odds ratio (OR) of 1.43 and 0.41, respectively. Furthermore, poor response was also seen in patients with a rise in CTGF on fibroblasts (OR 1.29) and P21 on vessels (OR 3.02) after treatment, P ConclusionBoth aHSCT and iv CYC in dcSSc reduced skin thickening clinically and attenuated EndMT, but affected cellular senescence not significantly different. EndMT and uPAR were associated with fibro-remodelling activity, whereas senescence, CTGF, uPAR and vascularity were associated with treatment response.Pathophysiology and treatment of rheumatic disease

    Association of endothelial to mesenchymal transition and cellular senescence with fibrosis in skin biopsies of systemic sclerosis patients: a cross-sectional study

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    OBJECTIVES:Fibrosis is the dominant hallmark of systemic sclerosis (SSc). Several mechanisms have been proposed to drive the disease process, but how these relate to skin fibrosis is poorly understood.METHODS:We performed a cross-sectional study on archival skin biopsies from 18 SSc patients and four controls. Dermal fibrosis and inflammatory cell infiltration were scored in HE and Masson’s Trichrome-stained sections. The presence of senescence was defined by P21 and/or P16 positivity in Ki-67 negative cells. Endothelial to mesenchymal transition (EndMT) was identified by co-localisation of CD31 and α-SMA in immunofluorescent double-stained sections, and by an enclosure of ERG positive endothelial cell nuclei by α-SMA stained cytoplasm in immunohistochemical double staining.RESULTS:The histological dermal fibrosis score of SSc skin biopsies was correlated with the modified Rodnan skin score (rho 0.55, p=0.042). Staining for markers of cellular senescence on fibroblasts was correlated with fibrosis score, inflammatory score, and CCN2 staining on fibroblasts. Moreover, EndMT was more abundant in skin from patients with SSc (pCONCLUSIONS:EndMT and fibroblast senescence were more abundant in skin biopsies from SSc patients. This finding indicates that both senescence and EndMT are involved in the pathway leading to skin fibrosis and might be valuable biomarkers and/or possible targets for novel therapeutic interventions. Pathophysiology and treatment of rheumatic disease

    Oxidative Stress and Cellular Senescence Are Involved in the Aging Kidney

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    Chronic kidney disease (CKD) can be considered as a clinical model for premature aging. However, non‐invasive biomarkers to detect early kidney damage and the onset of a senescent phenotype are lacking. Most of the preclinical senescence studies in aging have been done in very old mice. Furthermore, the precise characterization and over-time development of age-related senes-cence in the kidney remain unclear. To address these limitations, the age-related activation of cellular senescence-associated mechanisms and their correlation with early structural changes in the kidney were investigated in 3- to 18-month-old C57BL6 mice. Inflammatory cell infiltration was ob-served by 12 months, whereas tubular damage and collagen accumulation occurred later. Early activation of cellular-senescence-associated mechanisms was found in 12-month-old mice, character-ized by activation of the DNA-damage-response (DDR), mainly in tubular cells; activation of the antioxidant NRF2 pathway; and klotho downregulation. However, induction of tubular-cell-cycle-arrest (CCA) and overexpression of renal senescent-associated secretory phenotype (SASP) components was only found in 18-month-old mice. In aging mice, both inflammation and oxidative stress (marked by elevated lipid peroxidation and NRF2 inactivation) remained increased. These findings support the hypothesis that prolonged DDR and CCA, loss of nephroprotective factors (klotho), and dysfunctional redox regulatory mechanisms (NRF2/antioxidant defense) can be early drivers of age-related kidney-damage progressionThis research was funded by grants from the Instituto de Salud Carlos III (ISCIII); Fondos FEDER European Union (PI17/00119, PI20/00140; and DTS20/00083 to M.R.-O.; PI18/01133 to A.M.R.); Sara Borrell’ program from Instituto de Salud Carlos III (ISCIII) (grant number CD20/00042 to R.R.R.-D.); Red de Investigación Renal REDINREN: RD16/0009/0003 and RICORS program to RICORS2040 496 (RD21/0005), to M.R.-O., Sociedad Española de Nefrología; “NOVELREN-CM: Enfermedad renal crónica: nuevas Estrategias para la prevención, Diagnóstico y tratamiento” (B2017/BMD3751 to M.R.-O.); “Convocatoria Dinamización Europa Investigación 2019” MINECO (EIN2019-103294 to M.R.-O.); Juan de la Cierva incorporacion grant: IJC2018-035187-I to S.R.-M.; innovation program under the Marie Skłodowska-Curie grant of the European Union’s Horizon 2020 (IMProvePD ID: 812699) to M.R.-O.; and Fundacion Conchita Rabago to L.T.-
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