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The number of deaths from COVID-19 is closely associated with multimorbidities. This study aimed to review the clinical and functional conditions of patients who recovered from COVID-19. Additionally, identify the relationship with risk factors and comorbidities. Systemic arterial hypertension (SAH) was more frequently observed in patients with severe COVID-19. Diabetes mellitus (DM) is one of the comorbidities that has contributed the most to the increase in the number of hospitalizations due to complications and the number of deaths due to infection by COVID-19. Obesity has been shown to be a risk factor for hospitalization in patients with COVID-19 under 60 years of age. Most survivors of COVID-19 suffer primarily from muscle fatigue or weakness. In addition, patients who were more seriously ill during their hospital stay have greater impairment of functional capacity, pulmonary diffusion and fatigue symptoms, and are the main target population for long-term recovery interventions. To optimize the post-hospitalization rehabilitation of patients after discharge from COVID-19, the need for multidisciplinary work in rehabilitation, the reinforcement of public policies to ensure equity in access to the public health system and training should be considered of the health team in view of the new demands and realities generated by COVID-19.

The challenges that Latin America faces in health are deeply related to others, such as access to clean water, the right to education, and housing. Health professionals that work in an environment where the population faces constant barriers to accessing care in the public health system or has limited resources to pay for it in a private sector will face an ethical dilemma, the question of how to honor the call to care for patients when there is not enough support system or infrastructure to do so. Within the schools of medicine and health sciences, the question is how to train students to face or resolve these conflicts. The social responsibility approach is a proposal that allows the alignment of education for health professionals and health systems to contribute to the creation of an effective, equitable, and sustainable system. The present article aims to discuss this problem from the importance of training health professionals, ethical and committed to their communities, that have the skills and attitudes to implement a patient-centered vision. The involvement of universities and training institutions of the next generation of health professionals cannot be postponed.

Most patients with ovarian cancer (OvCA) present peritoneal disseminated disease at the time of diagnosis. During peritoneal metastasis, cancer cells detach from the primary tumor and disseminate through the intraperitoneal fluid. The peritoneal mesothelial cell (PMC) monolayer that lines the abdominal cavity is the first barrier encountered by OvCA cells. Subsequent progression of tumors through the peritoneum leads to the accumulation into the peritoneal stroma of a sizeable population of carcinoma‐associated fibroblasts (CAFs), which is mainly originated from a mesothelial‐to‐mesenchymal transition (MMT) process. A common characteristic of OvCA patients is the intraperitoneal accumulation of ascitic fluid, which is composed of cytokines, chemokines, growth factors, miRNAs, and proteins contained in exosomes, as well as tumor and mesothelial suspended cells, among other components that vary in proportion between patients. Exosomes are small extracellular vesicles that have been shown to mediate peritoneal metastasis by educating a pre‐metastatic niche, promoting the accumulation of CAFs via MMT, and inducing tumor growth and chemoresistance. This review summarizes and discusses the pivotal role of exosomes and MMT as mediators of OvCA peritoneal colonization and as emerging diagnostic and therapeutic targets., Ministry of Science and Innovation/Fondo Europeo de Desarrollo Regional (MICINN/FEDER), grant numbers PID2019-110132RB-I00/AEI/10.13039/501100011033 (to M.L.-C.) and SAF2016-77096-R (to C.C.), and by Consejo Superior de Investigaciones Científicas (CSIC), grant number 2020AEP018 (to C.C.)

El síndrome de Goldenhar es un trastorno heterogéneo, esporádico en su mayoría o por patrón de herencia autosómico dominante o recesivo, de la morfogénesis craneofacial asociada al primero y segundo arcos faríngeos, y forma parte del espectro oculoauriculovertebral. La incidencia es de 1 por cada 3500-45,000 recién nacidos vivos, con una razón de sexo masculino/femenino de 3:2.Se presenta el caso de un recién nacido con fenotipo de síndrome oculoauriculovertebral. Se abordó con radiografía de tórax, ecografía abdominal y tamizaje metabólico y auditivo, que reportaron hemivértebra torácica, fusión costal, quiste renal e hipoacusia bilateral profunda, respectivamente. Fue alimentado con lactancia mixta desde el nacimiento, sin lograr una succión adecuada y con pérdida de peso. A los 3 meses de edad recibió terapia de rehabilitación oral con electroestimulación en conjunto de 10 sesiones con 10 mA de intensidad, al igual que a los 23, 24, 25, 27, 30 y 32 meses de edad. A los 4 meses, espesamiento de fórmula con cereal; a los 7 meses, sonda de gastrostomía; a los 20 meses, cirugía de paladar y macrostomía. Mostró mejoría en intensidad de babeo en las primeras 10 sesiones y mejoría en la deglución a las 30 sesiones. A los 3 años de edad consume el 100% de los alimentos por vía oral.Con la escasa evidencia científica que este caso aislado aporta, el tratamiento con la terapia de rehabilitación en conjunto con la terapia convencional y la corrección anatómica dio resultados positivos para el trastorno de la deglución.Goldenhar syndrome is a heterogeneous disorder, mostly sporadic or due to a dominant autosomal or recessive pattern of inheritance, that exhibits craniofacial morphogenesis associated with the first and second pharyngeal arches and is part of the oculoauriculovertebral spectrum. Its incidence is of 1 in 3,500-45,000 live newborns, with a male to female ratio of 3:2.We describe the case of a male newborn with oculoauriculovertebral syndrome phenotype. It was approached with chest X-ray, abdominal ultrasound, metabolic and hearing screening, which reported thoracic hemivertebra, costal fusion, renal cyst, and profound bilateral hypoacusis, respectively. Although the newborn was fed with mixed lactation from birth, adequate suction and with weight loss were not achieved. At 3 months of age, as well as at 23, 24, 25, 27, 30 and 32 months of age, the infant received oral rehabilitation therapy with electrostimulation in a set of 10 sessions with 10 mA intensity. At 4 months, thickening of formula with cereal; at 7 months, gastrostomy tube; at 20 months, palate surgery and macrostomy. Improvement in drooling intensity was observed during the first 10 sessions, and improvement in swallowing after 30 sessions. At 3 years of age, the patient consumes 100% of food orally.According to limited scientific evidence that this isolated case provides, rehabilitation therapy together with conventional therapy coupled with anatomical correction gave positive results for swallowing disorder.

The physical, mental and social well being, refers to a new concept of health, far from a conceptualisations of absence of disease Additional challenges emerge as individuals face deep social inequities depending on their ethnicity, rural residence or low educational level, as these translate to poor access to health services and more difficulties to adhere to healthy living behaviors. The objective of this study was to assess the perception that adolescents and young adults in Latinamerica have of the importance of healthy living behaviors (HLB) in the physical, emotional and lifestyle spheres. The approach is considered quantitative and descriptive with a cross sectional design. The sampling consisted of 192 young adults in Brazil, Colombia and Mexico. The results show that participants prioritize higher emotional wellbeing. They state that the health crisis changed the perception, as now the value more the emotional side of health, and understand the status of a combination of the different aspects of wellness. The Latinamerican context poses a challenge in designing strategies with a holistic health perspective, with complexities in the economic and sociocultural domains.

Peritoneal hyalinizing vasculopathy (PHV) represents the cornerstone of long-term peritoneal dialysis (PD), and especially characterizes patients associated with encapsulating peritoneal sclerosis. However, the mechanisms of PHV development remain unknown. A cross sectional study was performed in 100 non-selected peritoneal biopsies of PD patients. Clinical data were collected and lesions were evaluated by immunohistochemistry. In selected biopsies a microRNA (miRNA)-sequencing analysis was performed. Only fifteen patients (15%) showed PHV at different degrees. PHV prevalence was significantly lower among patients using PD fluids containing low glucose degradation products (GDP) (5.9% vs. 24.5%), angiotensin converting enzyme inhibitors (ACEIs) (7.5% vs. 23.4%), statins (6.5% vs. 22.6%) or presenting residual renal function, suggesting the existence of several PHV protective factors. Peritoneal biopsies from PHV samples showed loss of endothelial markers and induction of mesenchymal proteins, associated with collagen IV accumulation and wide reduplication of the basement membrane. Moreover, co-expression of endothelial and mesenchymal markers, as well as TGF-β1/Smad3 signaling activation were found in PHV biopsies. These findings suggest that an endothelial-to-mesenchymal transition (EndMT) process was taking place. Additionally, significantly higher levels of miR-7641 were observed in severe PHV compared to non-PHV peritoneal biopsies. Peritoneal damage by GDPs induce miRNA deregulation and an EndMT process in submesothelial vessels, which could contribute to collagen IV accumulation and PHV., This research was funded by grants from the Instituto de Salud Carlos III (ISCIII) and Fondos FEDER European Union (PI15/00120 to R.S, PI18/00882 to M.A.B, PI17/00119 to M.R.-O. and Red de Investigación Renal (REDINREN): RD16/0009, to R.S and M.R-O); “Convocatoria Dinamización Europa Investigación 2019” MINECO (EIN2019-103294 to M.R.-O.); IMPROVE-PD project (“Identification and Management of Patients at Risk–Outcome and Vascular Events in Peritoneal Dialysis”) funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 812699 to M.R.-O. and M.L-C. Spanish Ministry of Science and Innovation/Fondo Europeo de Desarrollo Regional (MICINN/FEDER) (PID2019-110132RB-I00) to M.L.-C.

Understanding and targeting the molecular basis of peritoneal solute and protein transport is essential to improve peritoneal dialysis (PD) efficacy and patient outcome. Supplementation of PD fluids (PDF) with alanyl-glutamine (AlaGln) increased small solute transport and reduced peritoneal protein loss in a recent clinical trial. Transepithelial resistance and 10 kDa and 70 kDa dextran transport were measured in primary human endothelial cells (HUVEC) exposed to conventional acidic, glucose degradation products (GDP) containing PDF (CPDF) and to low GDP containing PDF (LPDF) with and without AlaGln. Zonula occludens-1 (ZO-1) and claudin-5 were quantified by Western blot and immunofluorescence and in mice exposed to saline and CPDF for 7 weeks by digital imaging analyses. Spatial clustering of ZO-1 molecules was assessed by single molecule localization microscopy. AlaGln increased transepithelial resistance, and in CPDF exposed HUVEC decreased dextran transport rates and preserved claudin-5 and ZO-1 abundance. Endothelial clustering of membrane bound ZO-1 was higher in CPDF supplemented with AlaGln. In mice, arteriolar endothelial claudin-5 was reduced in CPDF, but restored with AlaGln, while mesothelial claudin-5 abundance was unchanged. AlaGln supplementation seals the peritoneal endothelial barrier, and when supplemented to conventional PD fluid increases claudin-5 and ZO-1 abundance and clustering of ZO-1 in the endothelial cell membrane., This work is part of the IMPROVE-PD project that has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement number 812699. M.B. is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Projektnummer 419826430. R.H. was supported by a research fellowship of the European Renal Association and European Dialysis and Transplant Association (ERA-EDTA). E.L. was supported by the ÚNKP-18-2 New National Excellence Program of the Ministry of Human Capacities, Hungary. E.L. and H.J. were supported by Jellinek-Harry scholarship. S.G.Z. acknowledges the Alexander von Humboldt Stiftung/Foundation for an Experienced Researcher Fellowship (2019–2021) and the International Peritoneal Dialysis Society (ISPD) for an International Cooperation Research Grant (2019–2021). C.P.S. has obtained funding from European Nephrology and Dialysis Institute (ENDI).

Despite their emerging relevance to fully understand disease pathogenesis, we have as yet a poor understanding as to how biomechanical signals are integrated with specific biochemical pathways to determine cell behaviour. Mesothelial-to-mesenchymal transition (MMT) markers colocalized with TGF-β1-dependent signaling and yes-associated protein (YAP) activation across biopsies from different pathologies exhibiting peritoneal fibrosis, supporting mechanotransduction as a central driving component of these class of fibrotic lesions and its crosstalk with specific signaling pathways. Transcriptome and proteome profiling of the response of mesothelial cells (MCs) to linear cyclic stretch revealed molecular changes compatible with bona fide MMT, which (i) overlapped with established YAP target gene subsets, and were largely dependent on endogenous TGF-β1 signaling. Importantly, TGF-β1 blockade blunts the transcriptional upregulation of these gene signatures, but not the mechanical activation and nuclear translocation of YAP per se. We studied the role therein of caveolin-1 (CAV1), a plasma membrane mechanotransducer. Exposure of CAV1-deficient MCs to cyclic stretch led to a robust upregulation of MMT-related gene programs, which was blunted upon TGF-β1 inhibition. Conversely, CAV1 depletion enhanced both TGF-β1 and TGFBRI expression, whereas its re-expression blunted mechanical stretching-induced MMT. CAV1 genetic deficiency exacerbated MMT and adhesion formation in an experimental murine model of peritoneal ischaemic buttons. Taken together, these results support that CAV1-YAP/TAZ fine-tune the fibrotic response through the modulation of MMT, onto which TGF-β1-dependent signaling coordinately converges. Our findings reveal a cooperation between biomechanical and biochemical signals in the triggering of MMT, representing a novel potential opportunity to intervene mechanically induced disorders coursing with peritoneal fibrosis, such as post-surgical adhesions., MICINN and MINECO (SAF2014-51876-R and SAF2017-83130-R; MINSEV1512-07-2016; CSD2009-0016 and BFU2016-81912-REDC), Fundació La Marató de TV3 (674/C/2013); Worldwide Cancer Research; Sapienza University of Rome (RM116154BE5E14B2); CNIC is supported by the ISCIII, the MCIN and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505

Life-saving renal replacement therapy by peritoneal dialysis (PD) is limited in use and duration by progressive impairment of peritoneal membrane integrity and homeostasis. Preservation of peritoneal membrane integrity during chronic PD remains an urgent but long unmet medical need. PD therapy failure results from peritoneal fibrosis and angiogenesis caused by hypertonic PD fluid (PDF)-induced mesothelial cytotoxicity. However, the pathophysiological mechanisms involved are incompletely understood, limiting identification of therapeutic targets. We report that addition of lithium chloride (LiCl) to PDF is a translatable intervention to counteract PDF-induced mesothelial cell death, peritoneal membrane fibrosis, and angiogenesis. LiCl improved mesothelial cell survival in a dose-dependent manner. Combined transcriptomic and proteomic characterization of icodextrin-based PDF-induced mesothelial cell injury identified αB-crystallin as the mesothelial cell protein most consistently counter-regulated by LiCl. In vitro and in vivo overexpression of αB-crystallin triggered a fibrotic phenotype and PDF-like up-regulation of vascular endothelial growth factor (VEGF), CD31-positive cells, and TGF-β-independent activation of TGF-β-regulated targets. In contrast, αB-crystallin knockdown decreased VEGF expression and early mesothelial-to-mesenchymal transition. LiCl reduced VEGF release and counteracted fibrosis- and angiogenesis-associated processes. αB-crystallin in patient-derived mesothelial cells was specifically up-regulated in response to PDF and increased in peritoneal mesothelial cells from biopsies from pediatric patients undergoing PD, correlating with markers of angiogenesis and fibrosis. LiCl-supplemented PDF promoted morphological preservation of mesothelial cells and the submesothelial zone in a mouse model of chronic PD. Thus, repurposing LiCl as a cytoprotective PDF additive may offer a translatable therapeutic strategy to combat peritoneal membrane deterioration during PD therapy.

Research is a particularly underexplored professional activity for physicians, leaving many medical students compelled to pursue a clinical career. However, the XXI century requires that physicians innovate and perform research that fuels their practice; students should have early exposure to research to explore it as a career path. It should be encouraged in the undergraduate program by having students take part in case reports, short communication presentations, and research seminars. As part of an educational strategy, students worked with faculty members to deliver a gynecologic oncology pathology case report as a poster for the Oncology Conference of Medical Students. We used a quantitative approach with a descriptive and cross-sectional design to assess the effect of poster presentations on developing student's research skills. The sample comprised 118 medical students enrolled in the Pathology courses that presented a total of 23 posters. The judges who assessed had a medical specialty in Pathology, Radio-oncology, and Gynecologic Oncology. The results show that students exceeded expectations on the use of language, as it was both formal and technical; and they used relevant bibliographic support and references. However, students performed less well in the clinical case summary. The judges found that although it was coherent and chronologically ordered, they did not include all the relevant laboratory tests and analyses, nor a full description of the diagnosis. This educational strategy has proven to be valuable in promoting Pathology and Oncology Research in students; it allowed participants to adopt a systematic approach and methodologies to document, analyze, and share knowledge.

Chronic kidney disease (CKD) is a health problem reaching epidemic proportions. There is no cure for CKD, and patients may progress to end-stage renal disease (ESRD). Peritoneal dialysis (PD) is a current replacement therapy option for ESRD patients until renal transplantation can be achieved. One important problem in long-term PD patients is peritoneal membrane failure. The mechanisms involved in peritoneal damage include activation of the inflammatory and immune responses, associated with submesothelial immune infiltrates, angiogenesis, loss of the mesothelial layer due to cell death and mesothelial to mesenchymal transition, and collagen accumulation in the submesothelial compact zone. These processes lead to fibrosis and loss of peritoneal membrane function. Peritoneal inflammation and membrane failure are strongly associated with additional problems in PD patients, mainly with a very high risk of cardiovascular disease. Among the inflammatory mediators involved in peritoneal damage, cytokine IL-17A has recently been proposed as a potential therapeutic target for chronic inflammatory diseases, including CKD. Although IL-17A is the hallmark cytokine of Th17 immune cells, many other cells can also produce or secrete IL-17A. In the peritoneum of PD patients, IL-17A-secreting cells comprise Th17 cells, gamma delta T cells, mast cells, and neutrophils. Experimental studies demonstrated that IL-17A blockade ameliorated peritoneal damage caused by exposure to PD fluids. This article provides a comprehensive review of recent advances on the role of IL-17A in peritoneal membrane injury during PD and other PD-associated complications. This research was funded by grants from the Instituto de Salud Carlos III (ISCIII) and Fondos FEDER European Union (PI17/00119 to M.R.-O.; PI17/01495, DTS17/00203, and DTS19/00093 to J.E.; PI16/02057 and PI19/00815 to A.O.; PI 15/00120 to R.S; PI18/0610 to J.M.V.; and Red de Investigacion Renal (REDINREN): RD16/0009 to M.R.-O., A.O., R.S., and J.M.V.); by Comunidad de Madrid ("NOVELREN" B2017/BMD-3751 to M.R.-O. and B2017/BMD-3686 CIFRA2-CM to A.O.); by the "Juan de la Cierva Formacion" training program of the Ministerio de Economia, Industria y Competitividad (MINECO) supporting the salary of S.R.-M. (FJCI-2016-29050); by "Convocatoria Dinamizacion Europa Investigacion 2019" MINECO (EIN2019-103294 to M.R.-O. and S.R.-M.); by Sociedad Espanola de Nefrologia (S.E.N. to M.R.-O.); by ERA-PerMed-JTC2018 (KIDNEY ATTACK AC18/00064 and PERSTIGAN AC18/00071) and DTS18/00032 toA.O; by IMPROVE-PD project ("Identification and Management of Patients at Risk-Outcome and Vascular Events in Peritoneal Dialysis") with funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 812699 to M.R.O., M.L.-C., and D.F.; and by the Spanish Ministry of Science and Innovation/Fondo Europeo de Desarrollo Regional (MICINN/FEDER) (PID2019-110132RB-I00) to M.L.-C.

Antecedentes Una de las principales complicaciones de la diabetes mellitus es la amputacion de alguna extremidad. En todo el mundo, la prevalencia de amputaciones asociadas a la diabetes es muy variada y tiene un impacto considerable en la calidad de vida del paciente. Objetivo Analizar la frecuencia de las amputaciones en el Hospital Universitario Dr. Jose E. Gonzalez y evaluar si se presenta un patron estacional. Metodo Se realizo un estudio retrospectivo de 2009 a 2012, en el que se revisaron los expedientes de pacientes diabeticos que se sometieron a amputacion. La estacionalidad se analizo con la bondad de ajuste de ji al cuadrado. Resultados Se analizaron 456 amputaciones. Los resultados muestran que febrero es el mes que presenta la mayor frecuencia de amputaciones. La estacion anual con mayor numero de amputaciones fue el invierno. Conclusiones Las amputaciones en pacientes diabeticos del area metropolitana de Monterrey presentan un patron estacional, siendo los meses de invierno los de mayor frecuencia. Background The amputation of an extremity is a main complication of Diabetes mellitus. Worldwide the prevalence of amputations associated with diabetes mellitus is variable and had a considerable impact in the quality of life. Objective Analyze the frequency of amputations in the University Hospital, Dr Jose E Gonzalez and evaluate if a seasonal pattern is present. Method A retrospective analysis from 2009 to 2012 was carried out. Clinical files of diabetic patients undergoing to amputation were studied. The seasonality was evaluated with a chi square goodness of fit. Results A total of 456 amputations were studied. Results shown that February was the month with highest frequency of amputations while winter was the annual season with highest frequency of amputations. Conclusions Amputations of diabetic patients from Metropolitan Monterrey Mexico show a seasonal pattern being the winter months those that present highest frequency.

Peritoneal membrane failure due to fibrosis limits the use of peritoneal dialysis (PD). Peritoneal fibrosis may potentially be induced by sterile inflammation caused by ongoing cellular stress due to prolonged exposure to PD solutions (PDS). Effective therapies to prevent this process remain to be developed. Toll-like receptors (TLRs) mediate sterile inflammation by recognizing damage-associated molecular patterns (DAMPs) released by cellular stress. We evaluated the involvement of TLRs and DAMPs in PDS-induced fibrosis models and the therapeutic potential of TLR-DAMP targeting for preventing fibrosis. A range of PDS elicited pro-inflammatory and fibrotic responses from PD patient peritoneal leukocytes, mesothelial cells and mouse peritoneal leukocytes. TLR2/4 blockade of human peritoneal cells or TLR2/4 knockouts inhibited these effects. PDS did not induce rapid ERK phosphorylation or IκB-α degradation, suggesting that they do not contain components capable of direct TLR activation. However, PDS increased the release of Hsp70 and hyaluronan, both TLR2/4 DAMP ligands, by human and mouse peritoneal cells, and their blockade decreased PDS-driven inflammation. Soluble TLR2, a TLR inhibitor, reduced PDS-induced pro-inflammatory and fibrotic cytokine release ex vivo. Daily catheter infusion of PDS in mice caused peritoneal fibrosis, but co-administration of soluble TLR2 prevented fibrosis, suppressed pro-fibrotic gene expression and pro-inflammatory cytokine production, reduced leukocyte/neutrophil recruitment, recovered Treg cell levels and increased the Treg:Th17 ratio. Thus, TLR2/4, Hsp70 and hyaluronan showed major roles in PDS-induced peritoneal inflammation and fibrosis. The study demonstrates the therapeutic potential of a TLR-DAMP targeting strategy to prevent PDS-induced fibrosis.

Learning about forensic sciences is a crucial part of the formation of professionals working in medicine and health areas; this includes a range of coverage from legal-medical cases to forensic autopsies. However, knowledge of forensics by medical students is limited, because the teaching focus has been on the fundamentals of procedures in this field. To develop the necessary skills, specific support, and targeted learning tasks should be designed to enable the integration of interdisciplinary work in processes, infrastructure, and equipment used in a high-quality-forensic investigation. The innovative educational experience of the Crime Scene Investigation CSI Lab was a week-long activity using the pedagogical strategy of Challenge-Based Learning. It addresses the problem that students need training in an authentic setting. The intervention, in September 2017, included 33 students from different disciplines such as medicine, law, and marketing. They participated in various learning settings in multidisciplinary teams and were challenged by experts from the State Institute for Forensic Sciences to analyze specific processes. The outcomes of the CSI Lab implementations provided evidence of how the students benefited from the experience. The results showed that 80% of the teams had an excellent approach to the solution, justification of the proposal and feasibility assessment. However, only 60% achieved a solution that met the requirements. The educational process was assessed by their perceptions of the educational strategy of the CSI Lab experience. The results indicated that 88.9% of the students believed that the experience broadened their perspectives on forensic sciences. 73.1% thought that the design of the activities, visits, and plenaries added value to their academic training, and 88.9% found it to be interesting. Regarding whether or not the activities helped the participants to understand and perform a legal-medicine investigation, 92.6% believed that it did help them recognize and understand the interventional areas and processes necessary for the investigation. CONCLUSION: Students demonstrated high acceptance of the context-rich design of the practical activities and educational experiences that were grounded in active learning. The effect on curriculum design is that the interactions and interdisciplinarity of the programs must be assessed, as these experiences could motivate them to engage in solving the social challenges of the 21st century.

Peritoneal dialysis (PD) is a renal replacement therapy consistent on the administration and posterior recovery of a hyperosmotic fluid in the peritoneal cavity to drain water and toxic metabolites that functionally-insufficient kidneys are not able to eliminate. Unfortunately, this procedure deteriorates the peritoneum. Tissue damage triggers the onset of inflammation to heal the injury. If the injury persists and inflammation becomes chronic, it may lead to fibrosis, which is a common occurrence in many diseases. In PD, chronic inflammation and fibrosis, along with other specific processes related to these ones, lead to ultrafiltration capacity deterioration, which means the failure and subsequent cessation of the technique. Working with human samples provides information about this deterioration but presents technical and ethical limitations to obtain biopsies. Animal models are essential to study this deterioration since they overcome these shortcomings. A chronic mouse infusion model was developed in 2008, which benefits from the wide range of genetically modified mice, opening up the possibility of studying the mechanisms involved. This model employs a customized device designed for mice, consisting of a catheter attached to an access port that is placed subcutaneously at the back of the animal. This procedure avoids continuous puncture of the peritoneum during long-term experiments, reducing infections and inflammation due to injections. Thanks to this model, peritoneal damage induced by chronic PD fluid exposure has been characterized and modulated. This technique allows the infusion of large volumes of fluids and could be used for the study of other diseases in which inoculation of drugs or other substances over extended periods of time is necessary. This article shows the method for the surgical placement of the catheter in mice. Moreover, it explains the procedure for a 5/6 nephrectomy to mimic the state of renal insufficiency present in PD patients.

Background Epithelial-to-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) contributes to fibrotic thickening of the peritoneum that develops in patients on peritoneal dialysis (PD). The process is thought to be largely mediated by transforming growth factor-beta (TGF-β). As TGF-β has also been implicated in senescence of HPMCs, we have performed an exploratory study to examine if senescent HPMCs can undergo EMT. Methods Omentum-derived HPMCs were rendered senescent by repeated passages in culture. Features of EMT were assessed by immunostaining and quantitative polymerase chain reaction (qPCR) at various stages of the HPMC lifespan and after treatment with or without TGF-β. The motility of HPMCs was assessed in a scratch wound migration assay. Results Replicative senescence of HPMCs was associated with a gradual increase in the constitutive expression of EMT markers, including increased production of extracellular matrix proteins. However, senescent HPMCs also retained epithelial cell features such as cytokeratin, calretinin, and E-cadherin and showed decreased, rather than increased, motility. In contrast, exposure to TGF-β resulted in an up-regulation of mesenchymal markers and down-regulation of epithelial markers. Such effects of TGF-β occurred both in young and senescent cells, although they were less pronounced in senescence. Conclusions Senescence of HPMCs is associated with spontaneous development of several EMT features. At the same time, senescent HPMCs preserve epithelial cell-like characteristics and are less prone to develop a full EMT phenotype in response to TGF-β. These observations may support the concept of cellular senescence being antagonistically pleiotropic with regard to EMT.

Peritoneal dialysis (PD) therapy substantially requires biomarkers as tools to identify patients who are at the highest risk for PD-related complications and to guide personalized interventions that may improve clinical outcome in the individual patient. In this consensus article, members of the European Training and Research in Peritoneal Dialysis Network (EuTRiPD) review the current status of biomarker research in PD and suggest a selection of biomarkers that can be relevant to the care of PD patients and that are directly accessible in PD effluents. Currently used biomarkers such as interleukin-6, interleukin-8, ex vivo–stimulated interleukin-6 release, cancer antigen-125, and advanced oxidation protein products that were collected through a Delphi procedure were first triaged for inclusion as surrogate endpoints in a clinical trial. Next, novel biomarkers were selected as promising candidates for proof-of-concept studies and were differentiated into inflammation signatures (including interleukin-17, M1/M2 macrophages, and regulatory T cell/T helper 17), mesothelial-to-mesenchymal transition signatures (including microRNA-21 and microRNA-31), and signatures for senescence and inadequate cellular stress responses. Finally, the need for defining pathogen-specific immune fingerprints and phenotype-associated molecular signatures utilizing effluents from the clinical cohorts of PD patients and “omics” technologies and bioinformatics-biostatistics in future joint-research efforts was expressed. Biomarker research in PD offers the potential to develop valuable tools for improving patient management. However, for all biomarkers discussed in this consensus article, the association of biological rationales with relevant clinical outcomes remains to be rigorously validated in adequately powered, prospective, independent clinical studies.

Peritoneal dialysis (PD) is a life-saving form of renal replacement therapy for those with end-stage kidney disease. Mesothelial cells (MCs) line the peritoneal cavity and help define peritoneal response to treatment-associated injury, a major reason for treatment failure. miRNAs are important regulators, but their roles in peritoneal fibrosis are largely unknown. In this study, miR-21 was one of the most abundant miRNAs in primary MCs, and was up-regulated by the profibrotic cytokine transforming growth factor-β1 and in PD effluent-derived MCs exhibiting mesenchymal phenotypic change. Increased miR-21 was found in peritoneal membrane biopsy specimens from PD patients compared to healthy controls (PD biocompatible, 5.86×, P = 0.0001; PD conventional, 7.09×, P n = 11 per group). In PD effluent from a cohort of 230 patients, miR-21 was higher in those receiving the therapy long-term compared to new starters ( n = 230, miR-21 3.26×, P = 0.001) and associated with icodextrin use ( R = 0.52; 95% CI, 0.20–0.84), peritonitis count ( R = 0.16; 95% CI, 0.03–0.29), and dialysate cytokines. miR-21 down-regulated programmed cell death 4 and programmed cell death 4 protein was decreased in peritoneal membrane biopsy specimens from PD patients compared to healthy controls. New miR-21 targets were identified that may be important during PD fibrogenesis. These data identify miR-21 as an important effector of fibrosis in the peritoneal membrane, and a promising biomarker in the dialysis effluent for membrane change in patients receiving PD.

Peritoneal dissemination is the primary metastatic route of ovarian cancer (OvCa), and is often accompanied by the accumulation of ascitic fluid. The peritoneal cavity is lined by mesothelial cells (MCs), which can be converted into carcinoma-associated fibroblasts (CAFs) through mesothelial-to-mesenchymal transition (MMT). Here, we demonstrate that MCs isolated from ascitic fluid (AFMCs) of OvCa patients with peritoneal implants also undergo MMT and promote subcutaneous tumour growth in mice. RNA sequencing of AFMCs revealed that MMT-related pathways - including transforming growth factor (TGF)-β signalling - are differentially regulated, and a gene signature was verified in peritoneal implants from OvCa patients. In a mouse model, pre-induction of MMT resulted in increased peritoneal tumour growth, whereas interfering with the TGF-β receptor reduced metastasis. MC-derived CAFs showed activation of Smad-dependent TGF-β signalling, which was disrupted in OvCa cells, despite their elevated TGF-β production. Accordingly, targeting Smad-dependent signalling in the peritoneal pre-metastatic niche in mice reduced tumour colonization, suggesting that Smad-dependent MMT could be crucial in peritoneal carcinomatosis. Together, these results indicate that bidirectional communication between OvCa cells and MC-derived CAFs, via TGF-β-mediated MMT, seems to be crucial to form a suitable metastatic niche. We suggest MMT as a possible target for therapeutic intervention and a potential source of biomarkers for improving OvCa diagnosis and/or prognosis. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The classical view of the immune system has changed by the discovery of novel T-helper (Th) subsets, including Th17 (IL-17A-producing cells). IL-17A participates in immune-mediated glomerulonephritis and more recently in inflammatory pathologies, including experimental renal injury. Peritoneal dialysis patients present chronic inflammation and Th1/Th2 imbalance, but the role of the Th17 response in peritoneal membrane damage has not been investigated. In peritoneal biopsies from dialyzed patients, IL-17A immunostaining was found mainly in inflammatory areas and was absent in the healthy peritoneum. IL-17A-expressing cells included lymphocytes (CD4+ and γδ), neutrophils, and mast cells. Elevated IL-17A effluent concentrations were found in long-term peritoneal dialysis patients. Studies in mice showed that repeated exposure to recombinant IL-17A caused peritoneal inflammation and fibrosis. Moreover, chronic exposure to dialysis fluids resulted in a peritoneal Th17 response, including elevated IL-17A gene and protein production, submesothelial cell infiltration of IL-17A-expressing cells, and upregulation of Th17 differentiation factors and cytokines. IL-17A neutralization diminished experimental peritoneal inflammation and fibrosis caused by chronic exposure to dialysis fluids in mice. Thus, IL-17A is a key player of peritoneum damage and it may be a good candidate for therapeutic intervention in peritoneal dialysis patients.

Peritoneal dissemination is a frequent metastatic route for cancers of the ovary and gastrointestinal tract. Tumour cells metastasize by attaching to and invading through the mesothelial cell (MC) monolayer that lines the peritoneal cavity. Metastases are influenced by carcinoma-associated fibroblasts (CAFs), a cell population that derives from different sources. Hence, we investigated whether MCs, through mesothelial-mesenchymal transition (MMT), were a source of CAFs during peritoneal carcinomatosis and whether MMT affected the adhesion and invasion of tumour cells. Biopsies from patients with peritoneal dissemination revealed the presence of myofibroblasts expressing mesothelial markers in the proximity of carcinoma implants. Prominent new vessel formation was observed in the peritoneal areas harbouring tumour cells when compared with tumour-free regions. The use of a mouse model of peritoneal dissemination confirmed the myofibroblast conversion of MCs and the increase in angiogenesis at places of tumour implants. Treatment of omentum MCs with conditioned media from carcinoma cell cultures resulted in phenotype changes reminiscent of MMT. Adhesion experiments demonstrated that MMT enhanced the binding of cancer cells to MCs in a β1-integrin-dependent manner. Scanning electron microscopy imaging showed that the enhanced adhesion was mostly due to increased cell-cell interaction and not to a mere matrix exposure. Invasion assays suggested a reciprocal stimulation of the invasive capacity of tumour cells and MCs. Our results demonstrate that CAFs can derive from mesothelial cells during peritoneal metastasis. We suggest that MMT renders the peritoneum more receptive for tumour cell attachment/invasion and contributes to secondary tumour growth by promoting its vascularization. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., Ministerio de Economıa y Competitividad (SAF2010–21249); Comunidad Autonoma de Madrid (S2010/BMD-2321); Ministerio de Economıa y Competitividad (SAF2010-18733); Instituto de Salud Carlos III (PI10/00101); Fondo de Investigaciones Sanitarias (FIS); Fundacion Mutua Madrilena; Digna-Biotech; Asociacion Espanola Contra el Cancer; Fundación Ramón Areces

Peritoneal dialysis (PD) is an effective renal replacement therapy, but a significant proportion of patients suffer PD-related complications, which limit the treatment duration. Mesothelial-to-mesenchymal transition (MMT) contributes to the PD-related peritoneal dysfunction. We analyzed the genetic reprograming of MMT to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping between MMT induced in vitro and ex vivo in effluent-derived mesothelial cells, and that MMT is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. Cellular morphology and number of altered genes showed that MMT ex vivo could be subdivided into two stages: early/epithelioid and advanced/non-epithelioid. RT-PCR array analysis demonstrated that a number of genes differentially expressed in effluent-derived non-epithelioid cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were measured in PD effluents, and except GREM1, showed significant differences between early and advanced stages of MMT, and their expression was associated with a high peritoneal transport status. The results establish a proof of concept about the feasibility of measuring MMT-associated secreted protein levels as potential biomarkers in PD., Ministerio de Economía y Competitividad/Fondo Europeo de Desarrollo Regional (MINECO/FEDER) and by grant S2010/BMD-2321 (FIBROTEAM Consortium) from Comunidad Autónoma de Madrid

Introduction This study evaluated the influence of three-repetition training with a dental anaesthesia simulation model (DASM) on the perception of learning by dental students. Materials and methods Dental students who had never used a dental anaesthesia technique were randomly divided into two groups that were taught the anterior superior alveolar nerve infiltrative anaesthesia technique. Group 1 (G1; N = 10) followed a three-stage learning method: (i) theoretical lecture, (ii) clinical demonstration and (iii) DASM training, including three repetitions of the anaesthesia technique. Group 2 (G2; N = 10) followed only the 1st and 2nd stages. The students in both groups then performed the anaesthesia technique. The perception of the students was evaluated by four learning concepts. Each was evaluated with a 5-point Likert scale questionnaire. The average score of each item of the questionnaire for G1 was compared with that of G2. Statistically significant differences were identified with the Mann–Whitney test. The average working time of each group was timed and compared by Student's t-test to identify possible statistically significant differences. Results Students in G1 showed higher average scores of perception in controlling the handling of the dental syringe and confidence in performing the injection (P < 0.05) and showed an average working time shorter than that of the students in G2 (P < 0.05). Conclusion The DASM positively influenced the perception learning of the dental students; it increased their confidence and syringe handling ability, as well as skills to perform the injection of anaesthesia more quickly.

Matrix metalloproteinases (MMPs) contribute to the breakdown of tissue structures such as the basement membrane, promoting tissue fibrosis. Here we developed an electrospun membrane biofunctionalized with a fragment of the laminin β1-chain to modulate the expression of MMP2 in this context. We demonstrate that interfacing of the β1-fragment with the mesothelium of the peritoneal membrane via a biomaterial abrogates the release of active MMP2 in response to transforming growth factor β1 and rescues tissue integrity ex vivo and in vivo in a mouse model of peritoneal fibrosis. Importantly, our data demonstrate that the membrane inhibits MMP2 expression. Changes in the expression of epithelial-to-mesenchymal transition (EMT)-related molecules further point towards a contribution of the modulation of EMT. Biomaterial-based presentation of regulatory basement membrane signals directly addresses limitations of current therapeutic approaches by enabling a localized and specific method to counteract MMP2 release applicable to a broad range of therapeutic targets., Matrix metalloproteinase enzymes are widely known to contribute to the breakdown of tissues. Here, the authors utilise a biomaterial substrate functionalised with a laminin fragment to modulate the expression of these enzymes, subsequently controlling the integrity of tissue.

♦ Introduction: Chronic exposure to conventional peritoneal dialysis (PD) solutions has been related to peritoneal function alterations in PD patients, and associated with mesothelial cell loss, submesothelial fibrosis, vasculopathy, and angiogenesis. In vitro and ex vivo analyses, as well as studies with animal models, have demonstrated that biocompatible PD solutions attenuate these morphological alterations. Our aim was to confirm the morphological benefits of biocompatible solutions in PD patients. ♦ Methods: We analyzed biopsies from 23 patients treated with biocompatible solutions (study group, SG), and compared them with a control group (n = 23) treated with conventional solutions (CG), matched for time on PD. ♦ Results: A total of 56.5% of SG patients showed total or partial preservation of mesothelial cells monolayer, in contrast with 26.1% of patients in CG (p = 0.036). Peritoneal fibrosis was not significantly less frequent in SG patients (47.8% SG vs 69.6% CG; p = 0.13). In patients without previous peritonitis, a significantly lower prevalence of fibrosis was present in SG patients (41.7% SG vs 77.8% CG; p = 0.04). Hyalinizing vasculopathy (HV) was significantly lower in SG (4.3% SG vs 30.4% CG; p = 0.02). Cytokeratin-positive fibroblast-like cells were detected in 10 patients (22%), but the prevalence was not significantly lower in SG. In the univariate regression analysis, the use of biocompatible solutions was associated with mesothelial monolayer integrity (p = 0.04) and an absence of vasculopathy (p = 0.04). ♦ Conclusion: The present study demonstrates in vivo in human biopsies that biocompatible solutions are better tolerated by the peritoneum in the medium and long term than conventional solutions., Ministerio de Economia y Competitividad” to ML-C, by grant S2010/BMD-2321 from “Comunidad Autónoma de Madrid” to ML-C and RS, by grants from Fondo de Investigaciones Sanitarias” (PI 09/0641, 12/0204)

Fondo de Investigacion Sanitaria (PI10/00101); Fundacion Mutua Madrilena; SAF2007-61201; ISCIII/Agencia Lain Entralgo-FIB Hospital de La Princesa

Background Peritoneal membrane deterioration during peritoneal dialysis (PD) is associated with epithelial-to-mesenchymal transition (EMT) of mesothelial cells (MC), which is believed to be mainly due to glucose degradation products (GDPs) present in PD solutions. Here we investigate the impact of GDPs in PD solutions on the EMT of MC in vitro and ex vivo. Methods For in vitro studies, omentum-derived MC were incubated with standard PD fluid or low-GDP solution diluted 1:1 with culture medium. For ex vivo studies, 33 patients, who were distributed at random to either the 'standard' or the 'low GDP' groups, were followed over 24 months. Effluents were collected every 6 months to determine EMT markers in effluent MC. Results Exposure of MC to standard fluid in vitro resulted in morphological change into a non-epitheloid shape, down-regulation of E-cadherin, indicative of EMT, and in a strong induction of vascular endothelial growth factor (VEGF) expression. In contrast, in vitro exposure of MC to low-GDP solution did not lead to these phenotype changes. This could be confirmed ex vivo, as the prevalence of non-epitheloid phenotype of MC in the standard group was significantly higher with increasing PD duration and MC isolated from this group showed significantly higher levels of EMT-associated molecules including fibronectin, collagen I, VEGF, IL-8 and TGF-β levels when compared with the low-GDP group. Over time, the expression of E-cadherin also decreased in the standard but increased in the low-GDP group. In addition, the levels of EMT-associated molecules (fibronectin, VEGF and IL-8) increased in the standard but decreased in the low-GDP group. A similar trend was also observed for collagen I and for TGF-β (for the first year), but did not reach global statistical significance. Accordingly, effluent MC with non-epitheloid morphology showed significantly lower levels of E-cadherin and greater levels of fibronectin, collagen I, VEGF and IL 8 when compared with MC with epitheloid phenotype. The incidence of peritonitis did not significantly influence these results. Drop-out due to technique failure was less in the 'balance' group. The functional, renal and peritoneal evaluation of patients being treated with either standard or 'balance' fluid did not show any significant difference over time. Conclusions MC from PD effluent of patients treated with a PD fluid containing low GDP levels show fewer signs of EMT and the respective molecules than MC from patients treated with standard fluid, indicating a better preservation of the peritoneal membrane structure and a favourable outcome in patients using low-GDP fluid. It also confirms the hypothesis that the protection of EMT by GDP-reduced fluids is also present in vivo.

BACKGROUND: During peritoneal dialysis (PD), mesothelial cells (MC) undergo an epithelial-to-mesenchymal transition (EMT), and this process is associated with peritoneal membrane (PM) damage. Bone morphogenic protein-7 (BMP-7) antagonizes transforming growth factor (TGF)-beta1, modulates EMT and protects against fibrosis. Herein, we analysed the modulating role of BMP-7 on EMT of MC in vitro and its protective effects in a rat PD model.METHODS: Epitheliod or non-epitheliod MC were analysed for the expression of BMP-7, TGF-beta1, activated Smads, epithelial cadherin (E-cadherin), collagen I, alpha smooth muscle cell actin (alpha-SMA) and vascular endothelial growth factor (VEGF) using standard procedures. Rats were daily instilled with PD fluid with or without BMP-7 during 5 weeks. Histological analyses were carried out in parietal peritoneum. Fibrosis was quantified with van Gieson or Masson's trichrome staining. Vasculature, activated macrophages and invading MC were quantified by immunofluorescence analysis. Quantification of infiltrating leukocytes and MC density in liver imprints was performed by May-Grünwald-Giemsa staining. Hyaluronic acid levels were determined by ELISA.RESULTS: MC constitutively expressed BMP-7, and its expression was downregulated during EMT. Treatment with recombinant BMP-7 resulted in blockade of TGF-beta1-induced EMT of MC. We provide evidence of a Smad-dependent mechanism for the blockade of EMT. Exposure of rat peritoneum to PD fluid resulted in inflammatory and regenerative responses, invasion of the compact zone by MC, fibrosis and angiogenesis. Administration of BMP-7 decreased the number of invading MC and reduced fibrosis and angiogenesis. In contrast, BMP-7 had no effect on inflammatory and regenerative responses, suggesting that these are EMT-independent, and probably upstream, processes.CONCLUSIONS: Data point to a balance between BMP-7 and TGF-beta1 in the control of EMT and indicate that blockade of EMT may be a therapeutic approach to ameliorate peritoneal membrane damage during PD.

The precise mechanisms regulating hepatitis C virus (HCV) entry into hepatic cells remain unknown. However, several cell surface proteins have been identified as entry factors for this virus. Of these molecules, claudin-1, a tight junction (TJ) component, is considered a coreceptor required for HCV entry. Recently, we have demonstrated that HCV envelope glycoproteins (HCVgp) promote structural and functional TJ alterations. Additionally, we have shown that the intracellular interaction between viral E2 glycoprotein and occludin, another TJ-associated protein, could be the cause of the mislocalization of TJ proteins. Herein we demonstrated, by using cell culture-derived HCV particles (HCVcc), that interference of occludin expression markedly reduced HCV infection. Furthermore, our results with HCV pseudotyped particles indicated that occludin, but not other TJ-associated proteins, such as junctional adhesion molecule A or zonula occludens protein 1, was required for HCV entry. Using HCVcc, we demonstrated that occludin did not play an essential role in the initial attachment of HCV to target cells. Surface protein labeling experiments showed that both expression levels and cell surface localization of HCV (co)receptors CD81, scavenger receptor class B type I, and claudin-1 were not affected upon occludin knockdown. In addition, immunofluorescence confocal analysis showed that occludin interference did not affect subcellular distribution of the HCV (co)receptors analyzed. However, HCVgp fusion-associated events were altered after occludin silencing. In summary, we propose that occludin plays an essential role in HCV infection and probably affects late entry events. This observation may provide new insights into HCV infection and related pathogenesis.

During peritoneal dialysis (PD), exposure of the peritoneal membrane to nonphysiologic solutions causes inflammation, ultimately leading to altered structure and function. Myofibroblasts, one of the cell types that contribute to dysfunction of the peritoneal membrane, can originate from mesothelial cells (MCs) by epithelial-to-mesenchymal transition (EMT), a process that has been associated with an increased rate of peritoneal transport. Because cyclooxygenase-2 (COX-2) is induced by inflammation, we studied the role of COX-2 in the deterioration of the peritoneal membrane. We observed that nonepithelioid MCs found in peritoneal effluent expressed higher levels of COX-2 than epithelioid MCs. The mass transfer coefficient for creatinine correlated with MC phenotype and with COX-2 levels. Although COX-2 was upregulated during EMT of MCs in vitro, COX-2 inhibition did not prevent EMT. In a mouse model of PD, however, COX-2 inhibition with Celecoxib resulted in reduced fibrosis and in partial recovery of ultrafiltration, outcomes that were associated with a reduction of inflammatory cells. Furthermore, PD fluid with a low content of glucose degradation products did not induce EMT or COX-2; the peritoneal membranes of mice treated with this fluid showed less worsening than mice exposed to standard fluid. In conclusion, upregulation of COX-2 during EMT may mediate peritoneal inflammation, suggesting COX-2 inhibition as a potential strategy to ameliorate peritoneal deterioration in PD patients.

Chronic hepatitis B virus (HBV) infection is a major cause of liver fibrosis, eventually leading to cirrhosis and hepatocellular carcinoma. Although the involvement of the X protein of HBV (HBx) in viral replication and tumor development has been extensively studied, little is known about its possible role in the development of fibrosis. In this work we show that expression of HBx in hepatocytes results in paracrine activation and proliferation of hepatic stellate cells (HSCs), the main producers of extracellular matrix proteins in the fibrotic liver. Both human primary HSCs and rat HSCs exposed to conditioned medium from HBx-expressing hepatocytes showed increased expression of collagen I, connective tissue growth factor, α smooth muscle actin, matrix metalloproteinase-2, and transforming growth factor-β (TGF-β), together with an enhanced proliferation rate. We found that HBx induced TGF-β secretion in hepatocytes and that the activation of HSCs by conditioned medium from HBx-expressing hepatocytes was prevented by a neutralizing anti-TGF-β antibody, indicating the involvement of this profibrotic factor in the process. Conclusion: Our results propose a direct role for HBx in the development of liver fibrosis by the paracrine activation of stellate cells and reinforce the indication of antiviral treatment in patients with advanced HBV-related chronic liver disease and persistent liver replication. (HEPATOLOGY 2008.)

Ultrafiltration (UF) failure is a consequence of long-term peritoneal dialysis (PD). Fibrosis, angiogenesis, and vasculopathy are causes of this functional disorder after 3–8 years on PD. Epithelial-to-mesenchymal transition (EMT) of mesothelial cell (MC) is a key process leading to peritoneal fibrosis with functional deterioration. Our purpose was to study the peritoneal anatomical changes during the first months on PD, and to correlate them with peritoneal functional parameters. We studied 35 stable PD patients for up to 2 years on PD, with a mean age of 45.3±14.5 years. Seventy-four percent of patients presented loss of the mesothelial layer, 46% fibrosis (>150 μm) and 17% in situ evidence of EMT (submesothelial cytokeratin staining), which increased over time. All patients with EMT showed myofibroblasts, while only 36% of patients without EMT had myofibroblasts. The number of peritoneal vessels did not vary when we compared different times on PD. Vasculopathy was present in 17% of the samples. Functional studies were used to define the peritoneal transport status. Patients in the highest quartile of mass transfer area coefficient of creatinine (Cr-MTAC) (>11.8 ml min −1 ) showed significantly higher EMT prevalence ( P =0.016) but similar number of peritoneal vessels. In the multivariate analysis, the highest quartile of Cr-MTAC remained as an independent factor predicting the presence of EMT (odds ratio 12.4; confidence interval: 1.6–92; P =0.013) after adjusting for fibrosis ( P =0.018). We concluded that, during the first 2 PD years, EMT of MCs is a frequent morphological change in the peritoneal membrane. High solute transport status is associated with its presence but not with increased number of peritoneal vessels.

The implication of the tetraspanin CD9 in cancer has received much recent attention and an inverse correlation between CD9 expression and the metastatic potential and cancer survival rate has been established for different tumor types. In contrast to the well-established role of CD9 in metastasis, very little is known about the involvement of this tetraspanin in the process of development of primary tumors. In the present study, we present evidence on the implication of CD9 in colon carcinoma tumorigenesis. We report here that ectopic expression of CD9 in colon carcinoma cells results in enhanced integrin-dependent adhesion and inhibition of cell growth. Consistently with these effects, treatment of these cells with anti-CD9-specific antibodies resulted in (i) increased beta1 integrin-mediated cell adhesion through a mechanism involving clustering of integrin molecules rather than altered affinity; (ii) induction of morphological changes characterized by the acquisition of an elongated cell phenotype; (iii) inhibition of cell proliferation with no significant effect on cell survival; (iv) increased expression of membrane TNF-alpha, and finally (v) inhibition of the in vivo tumorigenic capacity in nude mice. In addition, through the use of selective blockers of TNF-alpha, we have demonstrated that this cytokine partly mediates the antiproliferative effects of CD9. These results clearly establish for the first time a role for CD9 in the tumorigenic process.

© 2015 The Authors. Uncontrolled extracellular matrix (ECM) production by fibroblasts in response to injury contributes to fibrotic diseases, including idiopathic pulmonary fibrosis (IPF). Reactive oxygen species (ROS) generation is involved in the pathogenesis of IPF. Transforming growth factor-β1 (TGF-β1) stimulates the production of NADPH oxidase 4 (NOX4)-dependent ROS, promoting lung fibrosis (LF). Dysregulation of microRNAs (miRNAs) has been shown to contribute to LF. To identify miRNAs involved in redox regulation relevant for IPF, we performed arrays in human lung fibroblasts exposed to ROS. miR-9-5p was selected as the best candidate and we demonstrate its inhibitory effect on TGF-β receptor type II (TGFBR2) and NOX4 expression. Increased expression of miR-9-5p abrogates TGF-β1-dependent myofibroblast phenotypic transformation. In the mouse model of bleomycin-induced LF, miR-9-5p dramatically reduces fibrogenesis and inhibition of miR-9-5p and prevents its anti-fibrotic effect both in vitro and in vivo. In lung specimens from patients with IPF, high levels of miR-9-5p are found. In omentum-derived mesothelial cells (MCs) from patients subjected to peritoneal dialysis (PD), miR-9-5p also inhibits mesothelial to myofibroblast transformation. We propose that TGF-β1 induces miR-9-5p expression as a self-limiting homeostatic response., Ministerio de Economía y Competitividad (MINECO) SAF 2012-31338 (SL), SAF 2013-47611 (MLC) and CSD 2007-00020 (SL), Instituto de Salud Carlos III REDinREN RD12/0021/0009 (SL and LGB) and FIS PS12/00094 (LGB), Comunidad de Madrid “Fibroteam” S2010/BMD-2321 (SL and MLC) and Fundación Renal “Iñigo Alvarez de Toledo” (SL), all from Spain. Supported by European Cooperation in Science and Research COST actions BM-1203 (EU-ROS) and BM-1005 (ENOGAS) (SL). The CBMSO receives institutional support from Fundación “Ramón Areces”.

Peritoneal adhesions (PAs) are fibrotic bands formed between bowel loops, solid organs, and the parietal peritoneum, which may appear following surgery, infection or endometriosis. They represent an important health problem with no effective treatment. Mesothelial cells (MCs) line the peritoneal cavity and undergo a mesothelial-to-mesenchymal transition (MMT) under pathological conditions, transforming into myofibroblasts, which are abundant in peritoneal fibrotic tissue. The aim of this study was to investigate if peritoneal MCs undergo a MMT contributing to the formation of post-surgical adhesions. Biopsies from patients with PAs were analysed by immunohistochemistry, immunofluorescence, and quantitative RT-PCR. A mouse model of PAs based on ischaemic buttons was used to modulate MMT by blocking the transforming growth factor-beta (TGF-β) pathway. The severity of adhesions and MMT-related marker expression were studied. We observed myofibroblasts derived from the conversion of MCs in submesothelial areas of patients with PAs. In addition, MMT-related markers were dysregulated in adhesion zones when compared to distant normal peritoneal tissue of the same patient. In animal experiments, blockage of TGF-β resulted in molecular reprogramming of markers related to the mesenchymal conversion of MCs and in a significant decrease in the severity of the adhesions. These data indicate for the first time that MMT is involved in PA pathogenesis. This finding opens new therapeutic strategies to interfere with adhesion formation by modulating MMT with a wide range of pharmacological agents.

// Georgios Liappas 1,* , Guadalupe Gonzalez-Mateo 1,* , Anna Rita Aguirre 2,* , Hugo Abensur 2 , Patricia Albar-Vizcaino 3 , Emilio Gonzalez Parra 4 , Pilar Sandoval 1 , Laura Garcia Ramirez 3 , Gloria del Peso 5 , Juan Manuel Acedo 6 , Maria A. Bajo 5 , Rafael Selgas 5 , Jose A. Sanchez Tomero 3 , Manuel Lopez-Cabrera 1 and Abelardo Aguilera 3 1 Immunology and Cellular Biology Department, Molecular Biology Centre Severo Ochoa, Madrid, Spain 2 Nephrology Department, University of Sao Paulo, School of Medicine, Sao Paulo, Brazil 3 Molecular Biology Unit and Nephrology Department, Hospital Universitario de La Princesa, Instituto de Investigacion Sanitaria Princesa (IP), Madrid, Spain 4 Nephrology Department, Fundacion Jimenez-Diaz, Instituto de Investigacion Sanitaria, Madrid, Spain 5 Nephrology Department, Instituto de Investigacion Hospital Universitario La Paz (IdiPAZ), Madrid, Spain 6 Cardiology Department, Clinica La Luz, Madrid, Spain * These authors have contributed equally to the work Correspondence to: Manuel Lopez-Cabrera, email: // Keywords : peritoneal dialysis, β-adrenergic receptor, nebivolol, type-I peritoneal membrane failure, peritoneal dialysis liquids, Pathology Section Received : July 29, 2015 Accepted : March 31, 2016 Published : April 18, 2016 Abstract Peritoneal dialysis (PD) is a form of renal replacement treatment, which employs the peritoneal membrane (PM) to eliminate toxins that cannot be removed by the kidney. The procedure itself, however, contributes to the loss of the PM ultrafiltration capacity (UFC), leading consequently to the technique malfunction. β-blockers have been considered deleterious for PM due to their association with loss of UFC and induction of fibrosis. Herein we analyzed the effects of Nebivolol, a new generation of β 1 -blocker, on PM alterations induced by PD fluids (PDF). In vitro: We found that mesothelial cells (MCs) express β 1 -adrenergic receptor. MCs were treated with TGF-β to induce mesothelial-to-mesenchymal transition (MMT) and co-treated with Nebivolol. Nebivolol reversed the TGF-β effects, decreasing extracellular matrix synthesis, and improved the fibrinolytic capacity, decreasing plasminogen activator inhibitor-1 (PAI-1) and increasing tissue-type plasminogen activator (tPA) supernatant levels. Moreover, Nebivolol partially inhibited MMT and decreased vascular endothelial growth factor (VEGF) and IL-6 levels in supernatants. In vivo : Twenty-one C57BL/6 mice were divided into 3 groups. Control group carried a catheter without PDF infusion. Study group received intraperitoneally PDF and oral Nebivolol during 30 days. PDF group received PDF alone. Nebivolol maintained the UFC and reduced PM thickness, MMT and angiogenesis promoted by PDF. It also improved the fibrinolytic capacity in PD effluents decreasing PAI-1 and IL-8 and increased tPA levels. Conclusion: Nebivolol protects PM from PDF-induced damage, promoting anti-fibrotic, anti-angiogenic, anti-inflammatory and pro-fibrinolytic effects.

Although it is well established that hepatitis C virus (HCV) entry into hepatocytes depends on clathrin-mediated endocytosis, the possible roles of clathrin in other steps of the viral cycle remain unexplored. Thus, we studied whether cell culture-derived HCV (HCVcc) exocytosis was altered after clathrin interference. Knockdown of clathrin or the clathrin adaptor AP-1 in HCVccinfected human hepatoma cell cultures impaired viral secretion without altering intracellular HCVcc levels or apolipoprotein B (apoB) and apoE exocytosis. Similar reductions in HCVcc secretion were observed after treatment with specific clathrin and dynamin inhibitors. Furthermore, detergent-free immunoprecipitation assays, neutralization experiments, and immunofluorescence analyses suggested that whereas apoE associated with infectious intracellular HCV precursors in endoplasmic reticulum (ER)-related structures, AP-1 participated in HCVcc egress in a post-ER compartment. Finally, we observed that clathrin and AP-1 knockdown altered the endosomal distribution of HCV core, reducing and increasing its colocalization with early endosome and lysosome markers, respectively. Our data support a model in which nascent HCV particles associate with apoE in the ER and exit cells following a clathrin-dependent transendosomal secretory route., This work was supported in part by the following grants: (i) grant SAF2010-21249 from the Ministerio de Ciencia e Investigación (MCI) to M.L.-C.; (ii) grant SAF2010-19270 from theMCIto P.G.; (iii) Marie Curie Career Integration grant PCIG-9-GA-2011-293664 from the European Union 7th Framework Programme for Research to P.G.; and (iv) FEDER funds via the Spanish Government to projects PI10/00101 and PI13/00159, from the Instituto de Salud Carlos III (ISCIII) Fondo de Investigaciónes Sanitarias (FIS) and the Fundación Mutua Madrileña, to P.L.M. I.B. was financially supported by Centro de Investigación Biomédica En Red de Enfermedades Hepáticas y Digestivas (CIBERehd), V.G. by FIS (PI10/00101), and F.M.-J. by ISCIII and Fundación para la Investigación Biomédica (FIB) del Hospital Universitario de la Princesa.

© 2015 Elsevier Ltd. Patients with Marfan syndrome (MFS) are at high risk of life-threatening aortic dissections. The condition is caused by mutations in the gene encoding fibrillin-1, an essential component in the formation of elastic fibers. While experimental findings in animal models of the disease have shown the involvement of transforming growth factor-β (TGF-β)- and angiotensin II-dependent pathways, alterations in the vascular extracellular matrix (ECM) may also play a role in the onset and progression of the aortic disease. Lysyl oxidases (LOX) are extracellular enzymes, which initiates the formation of covalent cross-linking of collagens and elastin, thereby contributing to the maturation of the ECM. Here we have explored the role of LOX in the formation of aortic aneurysms in MFS. We show that aortic tissue from MFS patients and MFS mouse model (Fbn1C1039G/+) displayed enhanced expression of the members of the LOX family, LOX and LOX-like 1 (LOXL1), and this is associated with the formation of mature collagen fibers. Administration of a LOX inhibitor for 8weeks blocked collagen accumulation and aggravated elastic fiber impairment, and these effects correlated with the induction of a strong and rapidly progressing aortic dilatation, and with premature death in the more severe MFS mouse model, Fbn1mgR/mgR, without any significant effect on wild type animals. This detrimental effect occurred preferentially in the ascending portion of the aorta, with little or no involvement of the aortic root, and was associated to an overactivation of both canonical and non-canonical TGF-β signaling pathways. The blockade of angiotensin II type I receptor with losartan restored TGF-β signaling activation, normalized elastic fiber impairment and prevented the aortic dilatation induced by LOX inhibition in Fbn1C1039G/+ mice. Our data indicate that LOX enzymes and LOX-mediated collagen accumulation play a critical protective role in aneurysm formation in MFS., Ministerio de Economía y Competitividad (Plan Nacional de I + D + I: SAF2012-34916), and Comunidad Autónoma deMadrid: 2010-BMD2321, FIBROTEAMConsortium, to F.R-P.; Howard Hughes Medical Institute, Smilow Center for Marfan Syndrome Research, The Marfan Foundation, and the National Institutes of Health (AR41135 and AR049698) to H.C.D.; and Ministerio de Economía y Competitividad (Plan Nacional de I + D + I: BFU2012- 33932), Fundación Ramón Areces and the National Marfan Foundation

Copyright © 2015 by the American Society of Nephrology. In patients undergoing peritoneal dialysis (PD), chronic exposure to nonphysiologic PD fluids elicits low-grade peritoneal inflammation, leading to fibrosis and angiogenesis. Phenotype conversion of mesothelial cells into myo fibroblasts, the so-called mesothelial-to-mesenchymal transition (MMT), significantly contributes to the peritoneal dysfunction related to PD. A number of factors have been described to induce MMT in vitro and in vivo, of which TGF-β1 is probably the most important. The vasoconstrictor peptide endothelin-1 (ET-1) is a transcriptional target of TGF-β1 and mediates excessive scarring and fibrosis in several tissues. This work studied the contribution of ET-1 to the development of peritoneal damage and failure in a mouse model of PD. ET-1 and its receptors were expressed in the peritoneal membrane and upregulated on PD fluid exposure. Administration of an ET receptor antagonist, either bosentan or macitentan, markedly attenuated PD-induced MMT, fibrosis, angiogenesis, and peritoneal functional decline. Adenovirus-mediated overexpression of ET-1 induced MMT in humanmesothelial cells in vitro and promoted the early cellular events associated with peritoneal dysfunction in vivo. Notably, TGF-β1-blocking peptides prevented these actions of ET-1. Furthermore, a positive reciprocal relationship was observed between ET-1 expression and TGF-β1 expression in human mesothelial cells. These results strongly support a role for an ET-1/TGF-β1 axis as an inducer of MMT and subsequent peritoneal damage and fibrosis, and they highlight ET-1 as a potential therapeutic target in the treatment of PD-associated dysfunction., We thank Macarena Quesada, Eva M. Blanco, and Jorge García for their technical assistance. O.B. is a recipient of a fellowship from the Ministerio de Economía y Competitividad (Formación de Personal Investigador). This work was supported by Ministerio de Economía y Competitividad Plan Nacional de I+D+I Grants SAF2012-31388 (to S.L.), SAF2010-21249 (to M.L.-C.), SAF2009-09085 (to F.R.-P.), and SAF2012-34916 (to F.R.-P.); Instituto de Salud “Carlos III” Grant REDinREN RD12/ 0021/0009 (to S.L. and F.R.-P.); Comunidad Autónoma de Madrid Grant 2010-BMD2321 (FIBROTEAM Consortium); and a grant from Fundación Renal “Iñigo Alvárez de Toledo.

Peritoneal dialysis (PD) is a form of renal replacement therapy whose repeated use can alter dialytic function through induction of epithelial-mesenchymal transition (EMT) and fibrosis, eventually leading to PD discontinuation. The peritoneum from Cav1(-/-) mice showed increased EMT, thickness, and fibrosis. Exposure of Cav1(-/-) mice to PD fluids further increased peritoneal membrane thickness, altered permeability, and increased the number of FSP-1/cytokeratin-positive cells invading the sub-mesothelial stroma. High-throughput quantitative proteomics revealed increased abundance of collagens, FN, and laminin, as well as proteins related to TGF-beta activity in matrices derived from Cav1(-/-) cells. Lack of Cav1 was associated with hyperactivation of a MEK-ERK1/2-Snail-1 pathway that regulated the Smad2-3/Smad1-5-8 balance. Pharmacological blockade of MEK rescued E-cadherin and ZO-1 inter-cellular junction localization, reduced fibrosis, and restored peritoneal function in Cav1(-/-) mice. Moreover, treatment of human PD-patient-derived MCs with drugs increasing Cav1 levels, as well as ectopic Cav1 expression, induced re-acquisition of epithelial features. This study demonstrates a pivotal role of Cav1 in the balance of epithelial versus mesenchymal state and suggests targets for the prevention of fibrosis during PD. We thank Dr. Kurzchalia, Dr. Pol, and Dr. Lisanti for providing us MEFs from WT and Cav1-/- mice. We thank Dr. Valeria Caiolfa, head of CNIC Microscopy unit, and Elvira Arza and Antonio Manuel Santos Beneit for technical assistance. We thank Cecilia Battistelli and Marta Loureiro Lopez por technical assistance in molecular biology and proteomics, respectively. This work was supported by grants from the MINECO (Spanish Ministry of Economy and Competitivity) to MADP (SAF2008-02100, SAF2011-25047 and CONSOLIDER CSD2009-00016) and to MLC (SAF2010-21249 and SAF2013-47611R), and from Fundacio la Marato TV3 (674/C/2013) to MADP. Raffaele Strippoli was supported by a Rio Hortega Contract (Instituto de Salud Carlos III). Ignacio Benedicto was recipient of a CIBERehd fellowship (Spanish Ministry of Health and Consumer Affairs). Susana Minguet was supported by the Ramon y Cajal program (Spanish Ministry of Science and Innovation). Simon Bartlett (CNIC) provided editorial assistance. The CNIC is supported by MINECO and the Pro-CNIC Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Sí

Fibrosis is a general complication in many diseases. It is the main complication during peritoneal dialysis (PD) treatment, a therapy for renal failure disease. Local inflammation and mesothelial to mesenchymal transition (MMT) are well known key phenomena in peritoneal damage during PD. New data suggest that, in the peritoneal cavity, inflammatory changes may be regulated at least in part by a delicate balance between T helper 17 and regulatory T cells. This paper briefly reviews the implication of the Th17/Treg-axis in fibrotic diseases. Moreover, it compares current evidences described in PD animal experimental models, indicating a loss of Th17/Treg balance (Th17 predominance) leading to peritoneal damage during PD. In addition, considering the new clinical and animal experimental data, new therapeutic strategies to reduce the Th17 response and increase the regulatory T response are proposed. Thus, future goals should be to develop new clinical biomarkers to reverse this immune misbalance and reduce peritoneal fibrosis in PD., This work was supported in part by grants from Ministerio de Economia y competitividad SAF2010-21249 to Manuel López-Cabrera, Comunidad Autónoma de Madrid 2010-BMD2321 (FIBROTEAM) to Manuel Lopez Cabrera, and Fondo de Investigaciones Santitarias RETICS 06/0016 and PI 09/0064 to Rafael Selgas and FIS 12/01175 to Abelardo Aguilera Peralta. Georgios Liappas is fully supported from European Union, Seventh Framework Program “EuTRiPD,” under Grant Agreement PITN-GA-2011-287813. The authors would like to thank Juliette Siegfried and her team at ServingMed.com for editing the language of the paper.

Context.—Mast cells (MCs) have been implicated in fibrogenesis, angiogenesis, and immunity against bacteria. These 3 mechanisms participate in the peritoneal pathology secondary to peritoneal dialysis (PD) treatment. Despite their potential relevance to PD-related pathology, few studies have focused on MCs.Objective.—To evaluate possible variations in the number of MCs during PD treatment.Design.—A quantitative study of tissue MCs in normal and pathologic peritoneum. Parietal peritoneal biopsies were collected from 4 groups: (1) normal controls (n = 9), (2) uremic non-PD patients (n = 16), (3) uremic patients on PD (n = 26), and (4) non-renal patients with inguinal hernia (n = 20). MCs were evaluated using immunohistochemistry for the detection of tryptase. The total number of cross sections of vessels per peritoneal field was examined in 22 of the 26 peritoneal biopsies of PD patients.Results.—PD tissue samples showed fibrosis, mesothelial cell loss, and variable hyalinizing vasculopathy. The number of MCs was similar in normal controls and non-PD uremic patients (mean ± SE: 7.13 ± 0.67 and 7.74 ± 0.74 MCs/mm2, respectively). Peritoneal dialysis patients showed a reduction (4 ± 0.38 MCs/mm2, P < .001), whereas hernia sac samples showed an increase (10.59 ± 3.48 MCs/mm2). MC reduction showed no correlation with time on dialysis, fibrosis, number of vessels, or previous episodes of peritonitis.Conclusions.—The peritoneum of patients receiving PD treatment shows a reduction of MCs. Despite such a reduction, fibrosis takes place, suggesting that MCs do not play a critical role in fibrosis genesis. Mast cell loss may be a contributory factor to peritonitis episodes in PD patients.

Background/Aims We aimed to explore the effects of hepatitis C virus (HCV) core and NS5A proteins on reactive oxygen (ROS) and nitrogen species (RNS) formation and on gene expression profile of iNOS in human hepatocyte-derived cells. Methods Production of ROS and RNS and nitrotyrosine residues accumulation were determined by flow cytometry and fluorescent microscopy as well as by Western blot, respectively, in NS5A- and core-transfected cells. Northern blot, Western blot, real-time PCR, and luciferase assays were used to assess iNOS gene expression in both transfectants. Results Cytokine-activated NS5A- and core-transfected cells induced ROS and RNS production but an earlier and more marked increase was observed in NS5A-expressing cells. Superoxide production was also augmented, showing a similar temporal pattern of appearance in both NS5A- and core-transfected cells. Although both NS5A and core HCV proteins were able to up-regulate iNOS gene expression, accompanied by a nitrotyrosine-containing proteins accumulation, an earlier iNOS overexpression was observed in NS5A-expressing cells, suggesting a different time course of iNOS activation pattern for core and NS5A HCV proteins. Conclusions Our results indicate a differential contribution of both HCV proteins to oxidative and nitrosative stress generation.

ObjectiveTo evaluate the utility of peritoneal pathologic samples, unrelated to peritoneal dialysis (PD) treatment, for the study of peritoneal fibrosis and inflammation.MethodsComparative morphologic and immunohistochemical study of peritoneal pathologic samples unrelated to PD with peritoneal biopsies from PD patients with special emphasis on the expression of myofibroblastic and epithelial-to-mesenchymal transition markers.ResultsRegarding morphology, PD-related simple fibrosis was less cellular, with greater stromal hyalinization, determining a homogeneous, hypocellular aspect of the submesothelium. In contrast, non-PD fibrosis was more cellular with an extracellular matrix showing a dense and fibrillar quality with wide bundles of collagen. Hylinazing vasculopathy was only present in PD samples. Myofibroblastic differentiation and epithelial-to-mesenchymal transition were common findings in all situations of peritoneal fibrosis. Calponin and calretinin are useful cellular markers to study such fibrogenic mechanisms and correlate with other well-known markers such as α-SMA and cytokeratins. Their expression was much more intense in those samples showing acute inflammation (peritonitis).ConclusionsNon-PD models of peritoneal fibrosis seem very useful to evaluate important features of human peritoneal pathology such us fibrogenesis, and inflammation. Fibrogenic events such as myofibroblastic differentiation and epithelial-to-mesenchymal transition are evident in these tissue samples allowing us to use them as an accessible source for in vivo and ex vivo studies. Both events show their maximal expression in situations of acute inflammation supporting the important role that peritonitis episodes play in the progression of fibrosis.

ObjectiveTo analyze the presence of myofibroblasts in a series of peritoneal dialysis (PD) patients with simple sclerosis and non-PD, uremic patients. Since there is a close correlation between active fibrosis and myofibroblastic differentiation we wanted to test if myofibroblasts are present in uremic, non-PD peritoneal samples. To determine if there are correlations between myofibroblastic presence and other functional and morphologic peritoneal parameters.MethodsBiopsies were collected from three patient groups: 1) Normal control samples (n=15) of parietal and visceral peritoneum 2) non-PD uremic patients (n=16); and 3) uremic patients on PD (n=32). Peritoneal morphologic and functional parameters and immunohistochemical expression of α-smooth muscle actin was analyzed in each case. Vascular endothelial growth factor (VEGF), bcl-2 anti-apoptotic protein, and progesterone receptor was evaluated in a subset of cases.ResultsMyofibroblasts were present in 56.3% of the patients with PD-related simple sclerosis. In most cases they were distributed in the upper submesothelial area. None of the biopsies from normal controls and uremic, non-PD patients showed myofibroblasts. Within the group of PD patients, myofibroblasts showed no correlation with time on dialysis, urea/creatinine MTAC, episodes of peritonitis, submesothelial thickening, hyalinizing vasculopathy or mesothelial status. In a subset of PD patients VEGF expression was observed in submesothelial fibroblastic cells. No expression of progesterone receptor or bcl-2 was observed.ConclusionsMyofibroblasts are a reliable and simple indicator of fibrosis since they appear in early stages of PD treatment and in patients with minor morphologic anomalies. They are not exclusive of patients with sclerosing peritonitis, ultrafiltration loss or long standing treatment. Their absence in non-PD, uremic patients suggest that uremia-related fibrosis takes place without a significant participation of myofibroblasts.

Background: Cyclooxygenase 2 (COX-2) and matrix metalloproteinases (MMPs) have been implicated in tissue injury and fibrogenesis in animal models but little is known regarding their role in hepatitis C virus (HCV) related liver disease in humans. Aims: To characterise the intrahepatic expression pattern of COX-2 and MMPs in chronic HCV infection and determine whether HCV core and NS5A proteins could promote their expression in cultured hepatocyte derived cell lines. Patients: Thirty two anti-HCV+ and 10 anti-HCV− patients were studied. Methods: Western blot, reverse transcription-polymerase chain reaction (RT-PCR), enzyme immunoassay, and immunohistochemistry were used to assess the expression pattern of COX-2 and MMPs in liver biopsy samples from all patients. COX-2 gene expression and MMP-9 protein levels were also determined by immunoblot, RT-PCR, and luciferase assays in core and NS5A transfected hepatocyte derived cells. Results: The intrahepatic expression level of COX-2, MMP-2, and MMP-9 was significantly higher in HCV+ than in HCV− patients, increasing with the fibrotic stage of liver disease. We further demonstrated that COX-2 mRNA, protein, and activity were induced in resting and activated core and NS5A transfectants. Both viral proteins induced transcriptional activity of the COX-2 gene promoter whereas core, but not NS5A, exerted an inducer effect on MMP-9 protein levels in cultured hepatocyte derived cells. Conclusions: Intrahepatic COX-2, MMP-2, and MMP-9 overexpression is associated with progressive hepatic fibrosis in chronic HCV infection, suggesting their pathogenic role in fibrogenesis. HCV core and NS5A proteins were able to upregulate COX-2 and MMP-9 gene expression in hepatocyte derived cells, providing a potential mechanism for hepatic fibrosis during chronic HCV infection.

CD5 is a surface receptor constitutively expressed on thymocytes and mature T and B-1a cells. CD5 expression is tightly regulated during T and B cell development and activation processes. In this study we shown that the constitutive expression of CD5 on human T cells correlates with the presence of a DNase I-hypersensitive (DH) site at the 5′-flanking region of CD5. Human CD5 is a TATA-less gene for which 5′-RACE analysis shows multiple transcriptional start sites, the most frequent of which locates within an initiator sequence. Luciferase reporter assays indicate that a 282-bp region upstream of the initiation ATG displays full promoter activity in human T cells. Two conserved Ets-binding sites (at positions −239 and −185) were identified as functionally relevant to CD5 expression by site-directed mutagenesis, EMSAs, and cotransfection experiments. A possible contribution of Sp1 (−115 and −95), c-Myb (−177), and AP-1-like (−151) motifs was also detected. Further DH site analyses revealed an inducible DH site 10 kb upstream of the human CD5 gene in both T and B CD5+ cells. Interestingly, a 140-bp sequence showing high homology with a murine inducible enhancer is found within that site. The data presented indicate that the 5′-flanking region of human CD5 is transcriptionally active in T cells, and that Ets transcription factors in conjunction with other regulatory elements are responsible for constitutive and tissue-specific CD5 expression.

Cohesins hold sister chromatids together from DNA replication until they are segregated. Although cohesins Smc1, Smc3, and Scc1/Rad21 are involved in chromatid cohesion and other cellular processes, little is known about the other mitotic cohesin subunit, Scc3/STAG. Here we describe STAG/Scc3, which may act as a transcriptional co-activator. STAG2 is able to enhance the activity of the tumor necrosis factor alpha, the CD69, and the human immunodeficiency virus long terminal repeat promoters in a NF-kappaB-dependent manner. In addition, STAG2 interacts with the viral transactivator Tat and enhances the Tat-mediated activation of the human immunodeficiency virus long terminal repeat promoter. Moreover, STAG2 co-activates a multimeric NF-kappaB reporter construct and enhances the activity of the transactivation domain of p65/RelA in a Gal4 system. This function is dependent on one of the LXXLL co-activation motives present in this cohesin and is substantiated by the interaction of STAG2 with the p65 subunit of NF-kappaB. These results describe a novel activity for cohesins, suggesting a role for STAG/Scc3 in transcriptional regulation.

Background/Aims : Liver growth factor (LGF) is a hepatic mitogen, however, the hepatic stimulation pathway remains to be characterized. The aim of this study was to determine whether tumor necrosis factor alpha (TNF-α) stimulation constitutes a step in the mitogenic pathway of LGF. Methods : Rats were injected with 4.5 μg LGF/rat, and LGF activity was measured both by liver DNA synthesis stimulation and ‘proliferating cell nuclear antigen (PCNA)-positive' hepatocytes in rats injected with LGF or +anti-TNF-α. TNF-α expression was evaluated by reverse-transcription polymerase chain reaction. TNF-α-producing cells were immunodetected. Human endothelial cells (HUVEC) were stimulated by LGF. TNF-α was detected in the supernatant, and the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial adhesion molecule-1 (VCAM-1) by flow cytometry analysis. Results : LGF-injected rats showed higher intrahepatic TNF-α expression. DNA synthesis and PCNA-positive hepatocytes induced by LGF were inhibited by anti-TNF-α, PCNA-positive hepatocytes being especially abundant around the central vein when LGF was injected alone, but TNF-α exhibited increased signal intensity in endothelial cells of the portal vein. LGF stimulated TNF-α secretion in HUVEC, but did not stimulate ICAM-1 or VCAM-1 up-regulation. Conclusions : The mitogenic cascade initiated by LGF in rat liver in vivo depends, at least in part, on TNF-α stimulation. Portal vein endothelial cells seem to be a source of TNF-α.