Transcriptional analysis reveals that the intracellular lipid accumulation impairs gene expression profiles involved in insulin response-associated cardiac functionality.

Cardiovascular disease (CVD) is a multisystemic and multicellular pathology that is generally associated with high levels of atherogenic lipoproteins in circulation. These lipoproteins tend to be retained and modified, for example, aggregated low-density lipoprotein (aggLDL), in the extracellular matrix of different tissues, such as the vascular wall and heart. The uptake of aggLDL generates a significant increase in cholesteryl ester (CE) in these tissues. We previously found that the accumulation of CE generates alterations in the insulin response in the heart. Although the insulin response is mainly associated with the uptake and metabolism of glucose, other studies have shown that insulin would fulfill functions in this tissue, such as regulating the calcium cycle and cardiac contractility. Here, we found that aggLDL induced-lipid accumulation altered the gene expression profile involved in processes essential for cardiac functionality, including insulin response and glucose uptake (Insr, Ins1, Pik3ip1, Slc2a4 gene expression), calcium cycle (Cacna1s and Gjc2 gene expression) and calcium-dependent cardiac contractility (Myh3), and cholesterol efflux (Abca1), in HL-1 cardiomyocytes. These observations were recapitulated using an in vivo model of hypercholesterolemic ApoE-KO mice. Altogether, these results may explain the deleterious effect of lipid accumulation in the myocardium, with important implications for lipid-overloaded associated CVD, including impaired insulin response, disrupted lipid metabolism, altered cardiac structure, and increased susceptibility to cardiovascular events.

Protective Effect of NO2-OA on Oxidative Stress, Gliosis, and Pro-Angiogenic Response in Müller Glial Cells.

Inflammation and oxidative and nitrosative stress are involved in the pathogenesis of proliferative retinopathies (PR). In PR, a loss of balance between pro-angiogenic and anti-angiogenic factors favors the secretion of vascular endothelial growth factor (VEGF). This vascular change results in alterations in the blood-retinal barrier, with extravasation of plasma proteins such as α2-macroglobulin (α2M) and gliosis in Müller glial cells (MGCs, such as MIO-M1). It is well known that MGCs play important roles in healthy and sick retinas, including in PR. Nitro-fatty acids are electrophilic lipid mediators with anti-inflammatory and cytoprotective properties. Our aim was to investigate whether nitro-oleic acid (NO2-OA) is beneficial against oxidative stress, gliosis, and the pro-angiogenic response in MGCs. Pure synthetic NO2-OA increased HO-1 expression in a time- and concentration-dependent manner, which was abrogated by the Nrf2 inhibitor trigonelline. In response to phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS), NO2-OA prevented the ROS increase and reduced the gliosis induced by α2M. Finally, when hypoxic MGCs were incubated with NO2-OA, the increase in VEGF mRNA expression was not affected, but under hypoxia and inflammation (IL-1ß), NO2-OA significantly reduced VEGF mRNA levels. Furthermore, NO2-OA inhibited endothelial cell (BAEC) tubulogenesis. Our results highlight NO2-OA's protective effect on oxidative damage, gliosis; and the exacerbated pro-angiogenic response in MGCs.

Experiencia del proceso de transición de adolescentes con enfermedades crónicas desde la atención pediátrica a la atención de adultos en un hospital general / Experience with the transition process of adolescents with chronic diseases from pediatric to adult care in a general hospital

Introducción. Es clave para la atención óptima de la salud la continuidad del cuidado al pasar de pediatría a la medicina del adulto. Objetivo. Describir la experiencia del proceso de transición de pacientes adolescentes conenfermedades crónicas desde la atención enpediatría a la atención de adultos en un hospital general. Población y métodos. Estudio de cortetransversal de pacientes entre 16 y 24 años con antecedente de trasplante hepático, trasplante renal, enfermedades endocrinas, metabólicas, reumatológicas y mielomeningocele atendidos en un hospital general universitario de tercer nivel entre 2015 y 2019, durante el proceso de transición. Se evaluaron el proceso de atención y el éxito de la transición. Se utilizó el cuestionario de evaluación de preparación para la transición (Transition Readiness Assessment QuestionnaireTRAQ, por su sigla en inglés). Resultados. Se incluyeron 372 pacientes. Las especialidades de atención más frecuentesfueron clínica de mielomeningocele, equipo de trasplante renal y de trasplante hepático. El 37 % participó del proceso de transición. La media de seguimiento por pediatría hasta el inicio de la transición fue de 9 años. La media de edad de comienzo de la transición fue 19 años y la media de edad de finalización, 21 años. La estrategia de transición más frecuente fue clínica conjunta en el 96 %. La mediana del TRAQ ordinal fue de 4; de estos, el 32 % ya había consultado a adultos. El 32,7 % cumplió con una transición exitosa. Conclusiones. La continuidad del cuidadodurante la transición es un proceso que llevó casi dos años y en más de un tercio de los pacientes se realizó en forma exitosa.

Introduction. The continuity of care from pediatrics to adult medicine is key to optimal health care. Objective. To describe the experience of the transition process of adolescent patients with chronic diseases from pediatric to adult care in a general hospital. Population and methods. Cross-sectional study of patients aged 16­24 years with a history of liver transplantation, kidney transplantation, endocrine, metabolic, rheumatic diseases, and myelomeningocele seen at a tertiary care teaching general hospital between 2015 and 2019 during the transition process. The process of health care and transition success were assessed. The Transition Readiness Assessment Questionnaire (TRAQ) was used. Results. A total of 372 patients were included. The myelomeningocele clinic, the kidney transplant and the liver transplant teams were the most common specialties. Thirty-seven percent of participants were involved in the transition process. The mean duration of follow-up by pediatrics until transition initiation was 9 years. The mean age at the beginning of transition was 19 years, and the mean age at the end, 21 years. The joint clinic transition strategy was the most frequent, used in 96% of cases. The median value of the ordinal TRAQ was 4; of these, 32% had already seen adult care physicians. A successful transition was achieved by 32.7%. Conclusions. The continuity of care during transition is a process that took almost 2 years; more than one third of the patients had a successful transition.

Experience with the transition process of adolescents with chronic diseases from pediatric to adult care in a general hospital. / Experiencia del proceso de transición de adolescentes con enfermedades crónicas desde la atención pediátrica a la atención de adultos en un hospital general.

INTRODUCTION: The continuity of care from pediatrics to adult medicine is key to optimal health care. OBJECTIVE: To describe the experience of the transition process of adolescent patients with chronic diseases from pediatric to adult care in a general hospital. POPULATION AND METHODS: Cross-sectional study of patients aged 16-24 years with a history of liver transplantation, kidney transplantation, endocrine, metabolic, rheumatic diseases, and myelomeningocele seen at a tertiary care teaching general hospital between 2015 and 2019 during the transition process. The process of health care and transition success were assessed. The Transition Readiness Assessment Questionnaire (TRAQ) was used. RESULTS: A total of 372 patients were included. The myelomeningocele clinic, the kidney transplant and the liver transplant teams were the most common specialties. Thirty-seven percent of participants were involved in the transition process. The mean duration of follow-up by pediatrics until transition initiation was 9 years. The mean age at the beginning of transition was 19 years, and the mean age at the end, 21 years. The joint clinic transition strategy was the most frequent, used in 96% of cases. The median value of the ordinal TRAQ was 4; of these, 32% had already seen adult care physicians. A successful transition was achieved by 32.7%. CONCLUSIONS: The continuity of care during transition is a process that took almost 2 years; more than one third of the patients had a successful transition.

Introducción. Es clave para la atención óptima de la salud la continuidad del cuidado al pasar de pediatría a la medicina del adulto. OBJETIVO: Describir la experiencia del proceso de transición de pacientes adolescentes con enfermedades crónicas desde la atención en pediatría a la atención de adultos en un hospital general. Población y métodos. Estudio de corte transversal de pacientes entre 16 y 24 años con antecedente de trasplante hepático, trasplante renal, enfermedades endocrinas, metabólicas, reumatológicas y mielomeningocele atendidos en un hospital general universitario de tercer nivel entre 2015 y 2019, durante el proceso de transición. Se evaluaron el proceso de atención y el éxito de la transición. Se utilizó el cuestionario de evaluación de preparación para la transición (Transition Readiness Assessment Questionnaire, TRAQ, por su sigla en inglés). RESULTADOS: Se incluyeron 372 pacientes. Las especialidades de atención más frecuentes fueron clínica de mielomeningocele, equipo de trasplante renal y de trasplante hepático. El 37 % participó del proceso de transición. La media de seguimiento por pediatría hasta el inicio de la transición fue de 9 años. La media de edad de comienzo de la transición fue 19 años y la media de edad de finalización, 21 años. La estrategia de transición más frecuente fue clínica conjunta en el 96 %. La mediana del TRAQ ordinal fue de 4; de estos, el 32 % ya había consultado a adultos. El 32,7 % cumplió con una transición exitosa. CONCLUSIONES: La continuidad del cuidado durante la transición es un proceso que llevó casi dos años y en más de un tercio de los pacientes se realizó en forma exitosa.

Multitarget Activities of Müller Glial Cells and Low-Density Lipoprotein Receptor-Related Protein 1 in Proliferative Retinopathies.

Müller glial cells (MGCs), the main glial component of the retina, play an active role in retinal homeostasis during development and pathological processes. They strongly monitor retinal environment and, in response to retinal imbalance, activate neuroprotective mechanisms mainly characterized by the increase of glial fibrillary acidic protein (GFAP). Under these circumstances, if homeostasis is not reestablished, the retina can be severely injured and GFAP contributes to neuronal degeneration, as they occur in several proliferative retinopathies such as diabetic retinopathy, sickle cell retinopathy and retinopathy of prematurity. In addition, MGCs have an active participation in inflammatory responses releasing proinflammatory mediators and metalloproteinases to the extracellular space and vitreous cavity. MGCs are also involved in the retinal neovascularization and matrix extracellular remodeling during the proliferative stage of retinopathies. Interestingly, low-density lipoprotein receptor-related protein 1 (LRP1) and its ligand α2-macroglobulin (α2M) are highly expressed in MGCs and they have been established to participate in multiple cellular and molecular activities with relevance in retinopathies. However, the exact mechanism of regulation of retinal LRP1 in MGCs is still unclear. Thus, the active participation of MGCs and LRP1 in these diseases, strongly supports the potential interest of them for the design of novel therapeutic approaches. In this review, we discuss the role of LRP1 in the multiple MGCs activities involved in the development and progression of proliferative retinopathies, identifying opportunities in the field that beg further research in this topic area.Summary StatementMGCs and LRP1 are active players in injured retinas, participating in key features such as gliosis and neurotoxicity, neovascularization, inflammation, and glucose control homeostasis during the progression of ischemic diseases, such as proliferative retinopathies.

Rapamycin and Resveratrol Modulate the Gliotic and Pro-Angiogenic Response in Müller Glial Cells Under Hypoxia.

Hypoxia and hypoxia-reoxygenation are frequently developed through the course of many retinal diseases of different etiologies. Müller glial cells (MGCs), together with microglia and astrocytes, participate firstly in response to the injury and later in the repair of tissue damage. New pharmacological strategies tend to modulate MGCs ability to induce angiogenesis and gliosis in order to accelerate the recovery stage. In this article, we investigated the variation in autophagy flux under hypoxia during 4 h, employing both gas culture chamber (1% O2) and chemical (CoCl2) hypoxia, and also in hypoxia-reoxygenation. Then, we delineated a strategy to induce autophagy with Rapamycin and Resveratrol and analysed the gliotic and pro-angiogenic response of MGCs under hypoxic conditions. Our results showed an increase in LC3B II and p62 protein levels after both hypoxic exposure respect to normoxia. Moreover, 1 h of reoxygenation after gas hypoxia upregulated LC3B II levels respect to hypoxia although a decreased cell survival was observed. Exposure to low oxygen levels increased the protein expression of the glial fibrillary acid protein (GFAP) in MGCs, whereas Vimentin levels remained constant. In our experimental conditions, Rapamycin but not Resveratrol decreased GFAP protein levels in hypoxia. Finally, supernatants of MGCs incubated in hypoxic conditions and in presence of the autophagy inductors inhibited endothelial cells (ECs) tubulogenesis. In agreement with these results, reduced expression of vascular endothelial growth factor (VEGF) mRNA was observed in MGCs with Rapamycin, whereas pigment epithelium-derived factor (PEDF) mRNA levels significantly increased in MGCs incubated with Resveratrol. In conclusion, this research provides evidence about the variation of autophagy flux under hypoxia and hypoxia-reoxygenation as a protective mechanism activated in response to the injury. In addition, beneficial effects were observed with Rapamycin treatment as it decreased the gliotic response and prevented the development of newly formed blood vessels.

Improved Performance of ELISA and Immunochromatographic Tests Using a New Chimeric A2-Based Protein for Human Visceral Leishmaniasis Diagnosis.

METHODS: A total of 1028 sera samples were used for the development and validation of ELISA (321 samples from L. infantum-infected patients, 62 samples from VL/AIDS coinfected patients, 236 samples from patients infected with other diseases, and 409 samples from healthy donors). A total of 520 sera samples were used to develop and validate ICT (249 samples from L. infantum-infected patients, 46 samples from VL/AIDS coinfected patients, 40 samples from patients infected with other diseases, and 185 samples from healthy donors). Findings. Using the validation sera panels, DTL-4-based ELISA displayed an overall sensitivity of 94.61% (95% CI: 89.94-97.28), a specificity of 99.41% (95% CI: 96.39-99.99), and an accuracy of 97.02% (95% CI: 94.61-98.38), while for ICT, sensitivity, specificity, and accuracy values corresponded to 91.98% (95% CI: 86.65-95.39), 100.00% (95% CI: 96.30-100.00), and 95.14% (95% CI: 91.62-97.15), respectively. When testing sera samples from VL/AIDS coinfected patients, DTL-4-ELISA displayed a sensitivity of 77.42% (95% CI: 65.48-86.16), a specificity of 99.41% (95% CI: 96.39-99.99), and an accuracy of 93.51% (95% CI: 89.49%-96.10%), while for DTL-4-ICT, sensitivity was 73.91% (95% CI: 59.74-84.40), specificity was 90.63% (95% CI: 81.02-95.63), and accuracy was 82.00% (95% CI: 73.63-90.91). CONCLUSION: DTL-4 is a promising candidate antigen for serodiagnosis of VL patients, including those with VL/AIDS coinfection, when incorporated into ELISA or ICT test formats.

Metabolic Syndrome Triggered by Fructose Diet Impairs Neuronal Function and Vascular Integrity in ApoE-KO Mouse Retinas: Implications of Autophagy Deficient Activation.

Metabolic syndrome is a disorder characterized by a constellation of clinical findings such as elevated blood glucose, hyperinsulinemia, dyslipidemia, hypertension, and obesity. A positive correlation has been found between metabolic syndrome or its components and retinopathy, mainly at microvascular level, in patients without a history of diabetes. Here, we extend the investigations beyond the vascular component analyzing functional changes as well as neuronal and glial response in retinas of Apolipoprotein E knockout (ApoE-KO) mice fed with 10% w/v fructose diet. Given that autophagy dysfunction is implicated in retinal diseases related to hyperglycemia and dyslipidemia, the activation of this pathway was also analyzed. Two months of fructose intake triggered metabolic derangements in ApoE-KO mice characterized by dyslipidemia, hyperglycemia and hyperinsulinemia. An increased number of TUNEL positive cells, in addition to the ganglion cell layer, was observed in the inner nuclear layer in retina. Vascular permeability, evidenced by albumin-Evans blue leakage and extravasation of albumin was also detected. Furthermore, a significant decrease of the glial fibrillary acidic protein expression was confirmed by Western blot analysis. Absence of both Müller cell gliosis and pro-angiogenic response was also demonstrated. Finally, retinas of ApoE-KO FD mice showed defective autophagy activation as judged by LC3B mRNA and p62 protein levels correlating with the increased cell death. These results demonstrated that FD induced in ApoE-KO mice biochemical alterations compatible with metabolic syndrome associated with neuronal impairment and mild vascular alterations in the retina.

Physiological changes in the hemolymph of juvenile shrimp Litopenaeus vannamei to sublethal nitrite and nitrate stress in low-salinity waters.

Juveniles of the shrimp Litopenaeus vannamei (3.3 ±â€¯0.4 g) were exposed separately to nitrite (0.0, 1.1, 2.6, and 5.3 mg/L nitrogen as nitrite [NO2--N]) and nitrate (0, 90, 225 and 400 mg/L nitrogen as nitrate [NO3--N]) concentrations equivalent to 0, 10, 25, and 50% of the LC50-96 h value of NO2--N and NO3--N in low salinity water (3 g/L). Shrimps responded to nitrite and nitrate according to changes in oxyhemocyanin, glucose, lactate and ion levels in the hemolymph after 6, 12, 24, and 48 h of exposure. Oxyhemocyanin levels decreased with increasing nitrite and nitrate levels and were higher at 50% exposure to the contaminants. Compared to the control, glucose and lactate increased significantly at 50% exposure to nitrite and nitrate, particularly at 12 and 24 h. Na+ in the hemolymph changed with nitrite and nitrate, while K+ only changed ˜with nitrite.

Calidad de vida de los hermanos de pacientes con enfermedad crónica / Quality of life among siblings of patients with chronic conditions

Introducción. La calidad de vida relacionada con la salud (CVRS) es una medida de resultado de salud. Evalúa el impacto subjetivo y global de las enfermedades en la vida cotidiana. Brinda información multidimensional sobre el bienestar físico, relación familiar y sus pares. Los estudios de CVRS de hermanos son limitados.Objetivo. Comparar CVRS de los hermanos de pacientes pediátricos con patologías reumáticas crónicas, trasplante renal o hepático con la de niños sanos con hermanos sin enfermedades crónicas.Resultados. Se compararon hermanos de niños con trasplante renal (n: 65), trasplante hepático (n: 35) y patologías reumáticas crónicas (n: 36) con el grupo control de niños sanos (n: 51). El grupo total de hermanos tuvieron puntuación más baja, estadísticamente significativa, en las dimensiones bienestar físico, amigos-apoyo social y recursos económicos. Los hermanos de trasplante renal tuvieron baja puntuación en las dimensiones de bienestar físico (p < 0,02; tamaño del efecto ­TE­: 0,66) y recursos económicos (p < 0,01; TE: 0,66). Los hermanos de trasplante hepático percibieron menor bienestar físico (p = 0,04), tenían menos amigos y apoyo social (p < 0,01), dificultades en el entorno escolar (p < 0,02) y recursos económicos (p < 0,01). Los hermanos de patologías reumáticas crónicas tuvieron menor bienestar físico (p < 0,05; TE: 0,44) y apoyo social-amigos (p < 0,01; TE: 0,58).Conclusión. La CVRS de niños/as sanos de hermanos con patologías crónicas es menor en bienestar físico, amigos-apoyo social y recursos económicos comparada con el grupo de niños sanos.

Introduction. Health-related quality of life (HRQoL) is a measure of health outcomes. It assesses the subjective and overall impact of diseases on daily life. It also provides multidimensional data about physical well-being, family and peers relations. HRQoL studies on siblings are limited.Objective. To compare HRQoL among siblings of pediatric patients with chronic rheumatic diseases, kidney or liver transplant and healthy children whose siblings had no chronic conditions.Results. The siblings of children with kidney transplant (n: 65), liver transplant (n: 35), and chronic rheumatic diseases (n: 36) were compared to the healthy children group (n: 51). The total siblings group had a lower, statistically significant score in the physical well-being, social support and peers, and financial resources dimensions. The siblings of kidney transplant patients had a low score in the physical well-being (p < 0.02; effect size [ES]: 0.66) and financial resources (p < 0.01; ES: 0.66) dimensions. The siblings of liver transplant patients perceived a lower physical well-being (p = 0.04), less social support and peers(p < 0.01), and difficulties in relation to school environment (p < 0.02) and financial resources (p < 0.01). The siblings of those with chronic rheumatic diseases had a lower score in the physical well-being (p < 0.05; ES: 0.44) and social support and peers (p < 0.01; ES: 0.58) dimensions.Conclusion. HRQoL among healthy children whose siblings have a chronic disease was lower in the physical well-being, social support and peers, and financial resources dimensions compared to the healthy children group.

Quality of life among siblings of patients with chronic conditions. / Calidad de vida de los hermanos de pacientes con enfermedad crónica.

INTRODUCTION: Health-related quality of life (HRQoL) is a measure of health outcomes. It assesses the subjective and overall impact of diseases on daily life. It also provides multidimensional data about physical wellbeing, family and peers relations. HRQoL studies on siblings are limited. OBJECTIVE: To compare HRQoL among siblings of pediatric patients with chronic rheumatic diseases, kidney or liver transplant and healthy children whose siblings had no chronic conditions. RESULTS: The siblings of children with kidney transplant (n: 65), liver transplant (n: 35), and chronic rheumatic diseases (n: 36) were compared to the healthy children group (n: 51). The total siblings group had a lower, statistically significant score in the physical well-being, social support and peers, and financial resources dimensions. The siblings of kidney transplant patients had a low score in the physical wellbeing (p < 0.02; effect size [ES]: 0.66) andfinancial resources (p < 0.01; ES: 0.66) dimensions. The siblings of liver transplant patients perceived a lower physical well-being (p = 0.04), less social support and peers (p < 0.01), and difficulties in relation to school environment (p < 0.02) and financial resources (p <0.01). The siblings of those with chronic rheumatic diseases had a lower score in the physical well-being (p < 0.05; ES: 0.44) and social support and peers (p <0.01; ES: 0.58) dimensions. CONCLUSION: HRQoL among healthy children whose siblings have a chronic disease was lower in the physical well-being, social support and peers, and financial resources dimensions compared to the healthy children group.

Introducción. La calidad de vida relacionada con la salud (CVRS) es una medida de resultado de salud. Evalúa el impacto subjetivo y global de las enfermedades en la vida cotidiana. Brinda información multidimensional sobre el bienestar físico, relación familiar y sus pares. Los estudios de CVRS de hermanos son limitados. Objetivo. Comparar CVRS de los hermanos de pacientes pediátricos con patologías reumáticas crónicas, trasplante renal o hepático con la de niños sanos con hermanos sin enfermedades crónicas. Resultados. Se compararon hermanos de niños con trasplante renal (n: 65), trasplante hepático (n: 35) y patologías reumáticas crónicas (n: 36) con el grupo control de niños sanos (n: 51). El grupo total de hermanos tuvieron puntuación más baj a, estadísticamente significativa, enlas dimensiones bienestar físico, amigos-apoyo social y recursos económicos. Los hermanos de trasplante renal tuvieron baja puntuación en las dimensiones de bienestar físico (p < 0,02; tamaño del efecto -TE-: 0,66) y recursos económicos (p < 0,01; TE: 0,66). Los hermanos de trasplante hepático percibieron menor bienestar físico (p = 0,04), tenían menos amigos y apoyo social (p < 0,01), dificultades en el entorno escolar (p < 0,02) y recursos económicos (p < 0,01). Los hermanos de patologías reumáticas crónicas tuvieron menor bienestar físico (p < 0,05; TE: 0,44) y apoyo social-amigos (p < 0,01; TE: 0,58). Conclusión. La CVRS de niños/as sanos de hermanos con patologías crónicas es menor en bienestar físico, amigos-apoyo social y recursos económicos comparada con el grupo de niños sanos.

Activated α2-Macroglobulin Regulates LRP1 Levels at the Plasma Membrane through the Activation of a Rab10-dependent Exocytic Pathway in Retinal Müller Glial Cells.

Activated α2-macroglobulin (α2M*) and its receptor, low-density lipoprotein receptor-related protein 1 (LRP1), have been linked to proliferative retinal diseases. In Müller glial cells (MGCs), the α2M*/LRP1 interaction induces cell signaling, cell migration, and extracellular matrix remodeling, processes closely associated with proliferative disorders. However, the mechanism whereby α2M* and LRP1 participate in the aforementioned pathologies remains incompletely elucidated. Here, we investigate whether α2M* regulates both the intracellular distribution and sorting of LRP1 to the plasma membrane (PM) and how this regulation is involved in the cell migration of MGCs. Using a human Müller glial-derived cell line, MIO-M1, we demonstrate that the α2M*/LRP1 complex is internalized and rapidly reaches early endosomes. Afterward, α2M* is routed to degradative compartments, while LRP1 is accumulated at the PM through a Rab10-dependent exocytic pathway regulated by PI3K/Akt. Interestingly, Rab10 knockdown reduces both LRP1 accumulation at the PM and cell migration of MIO-M1 cells induced by α2M*. Given the importance of MGCs in the maintenance of retinal homeostasis, unravelling this molecular mechanism can potentially provide new therapeutic targets for the treatment of proliferative retinopathies.

Effect of Autophagy Modulators on Vascular, Glial, and Neuronal Alterations in the Oxygen-Induced Retinopathy Mouse Model.

Hypoxia is one of the main insults in proliferative retinopathies, leading to neovascularization and neurodegeneration. To maintain homeostasis, neurons require efficient degradation and recycling systems. Autophagy participates in retinal cell death, but it is also a cell survival mechanism. Here, we analyzed the role of autophagy at the three characteristic time periods in the oxygen-induced retinopathy (OIR) mouse model and determined if its modulation can improve vascular and non-vascular alterations. Experiments were performed with chloroquine (CQ) in order to monitor autophagosome accumulation by lysosomal blockade. Post natal day (P)17 OIR mouse retinas showed a significant increase in autophagy flux. In particular, an intense LC3B and p62 staining was observed in inner layers of the retina, mainly proliferating endothelial cells. After a single intraocular injection of Rapamycin at P12 OIR, a decreased neovascular area and vascular endothelial growth factor (VEGF) protein expression were observed at P17 OIR. In addition, whereas the increased expression of glial fibrillary acidic protein (GFAP) was reversed at P26 OIR, the functional alterations persisted. Using a similar therapeutic schedule, we analyzed the effect of anti-VEGF therapy on autophagy flux. Like Rapamycin, VEGF inhibitor treatment not only reduced the amount of neovascular tufts, but also activated autophagy flux at P17 OIR, mainly in ganglion cell layer and inner nuclear layer. Finally, the effects of the disruption of autophagy by Spautin-1, were evaluated at vascular, glial, and neuronal levels. After a single dose of Spautin-1, Western blot analysis showed a significant decrease in LC3B II and p62 protein expression at P13 OIR, returning both autophagy markers to OIR control levels at P17. In addition, neither gliosis nor functional alterations were attenuated. In line with these results, TUNEL staining showed a slight increase in the number of positive cells in the outer nuclear layer at P17 OIR. Overall, our results demonstrate that all treatments of induction or inhibition of the autophagic flux reduced neovascular area but were unable to completely reverse the neuronal damage. Besides, compared to current treatments, rapamycin provides a more promising therapeutic strategy as it reduces both neovascular tufts and persistent gliosis.

Toxicity of ammonia, nitrite and nitrate to Litopenaeus vannamei juveniles in low-salinity water in single and ternary exposure experiments and their environmental implications.

Information on toxicity of nitrogen compounds for Litopenaeus vannamei in coastal ecosystems and culture under low salinity is scarce. Acute toxicity trials were conducted in L. vannamei to determine the single and combined effects of ammonia, nitrite and nitrate at a salinity of 3 g/L. The 96 h-LC50 was 29.0 mg/L for total ammonia nitrogen (TAN); 10.6 mg/L for nitrogen as nitrite (NO2--N); and 900 mg/L for nitrogen as nitrate (NO3--N). The joint effects of ammonia, nitrite and nitrate exposure were antagonistic at 24-72 h; and additive from 72 to 96 h. The proposed safety levels of single exposure to TAN, NO2--N and NO3--N for L. vannamei are 1.45, 0.53 and 45.0 mg/L, respectively. When in mixture, the proposed level of TAN/NO2--N/NO3--N is 0.05 TU (Toxicity Unit) corresponding to 0.48, 0.08 and 14.6 mg/L of TAN, NO2--N and NO3--N, respectively.

A journey into the retina: Müller glia commanding survival and death.

Müller glial cells (MGCs) are known to participate actively in retinal development and to contribute to homoeostasis through many intracellular mechanisms. As there are no homologous cells in other neuronal tissues, it is certain that retinal health depends on MGCs. These macroglial cells are located at the centre of the columnar subunit and have a great ability to interact with neurons, astrocytes, microglia and endothelial cells in order to modulate different events. Several investigations have focused their attention on the role of MGCs in diabetic retinopathy, a progressive pathology where several insults coexist. As expected, data suggest that MGCs display different responses according to the severity of the stimulus, and therefore trigger distinct events throughout the course of the disease. Here, we describe physiological functions of MGCs and their participation in inflammation, gliosis, synthesis and secretion of trophic and antioxidant factors in the diabetic retina. We invite the reader to consider the protective/deleterious role of MGCs in the early and late stages of the disease. In the light of the results, we open up the discussion around and ask the question: Is it possible that the modulation of a single cell type could improve or even re-establish retinal function after an injury?

Acute Toxicity of Ammonia, Nitrite and Nitrate to Shrimp Litopenaeus vannamei Postlarvae in Low-Salinity Water.

Shrimp farming in low salinities waters is an alternative to increasing production, and counteracting disease problems in brackish and marine waters. However, in low-salinity waters, toxicity of nitrogen compounds increases, and there is no available data of its acute toxicity in shrimp postlarvae. This study determined the acute toxicity of ammonia, nitrite and nitrate in Litopenaeus vannamei postlarvae in 1 and 3 g/L salinity, as well as the safety levels. The LC50 confirms that nitrite is more toxic than ammonia and nitrate in low salinity waters, and that its toxicity increases with a decrease in salinity. The safe levels estimated for salinities of 1 and 3 g/L were 0.54 and 0.81 mg/L for total ammonia-N, 0.17 and 0.25 mg/L for NO2-N, and 5.6 and 21.5 mg/L for NO3-N, respectively.

Insulin-induced exocytosis regulates the cell surface level of low-density lipoprotein-related protein-1 in Müller Glial cells.

Low-density lipoprotein (LDL) receptor-related protein-1 (LRP1) is expressed in retinal Müller glial cells (MGCs) and regulates intracellular translocation to the plasma membrane (PM) of the membrane proteins involved in cellular motility and activity. Different functions of MGCs may be influenced by insulin, including the removal of extracellular glutamate in the retina. In the present work, we investigated whether insulin promotes LRP1 translocation to the PM in the Müller glial-derived cell line MIO-M1 (human retinal Müller glial cell-derived cell line). We demonstrated that LRP1 is stored in small vesicles containing an approximate size of 100 nm (mean diameter range of 100-120 nm), which were positive for sortilin and VAMP2, and also incorporated GLUT4 when it was transiently transfected. Next, we observed that LRP1 translocation to the PM was promoted by insulin-regulated exocytosis through intracellular activation of the IR/PI3K/Akt axis and Rab-GTPase proteins such as Rab8A and Rab10. In addition, these Rab-GTPases regulated both the constitutive and insulin-induced LRP1 translocation to the PM. Finally, we found that dominant-negative Rab8A and Rab10 mutants impaired insulin-induced intracellular signaling of the IR/PI3K/Akt axis, suggesting that these GTPase proteins as well as the LRP1 level at the cell surface are involved in insulin-induced IR activation.

IGF-1R Regulates the Extracellular Level of Active MMP-2, Pathological Neovascularization, and Functionality in Retinas of OIR Mouse Model.

In ischemic proliferative diseases such as retinopathies, persistent hypoxia leads to the release of numerous neovascular factors that participate in the formation of abnormal vessels and eventually cause blindness. The upregulation and activation of metalloproteinases (MMP-2 and MMP-9) represent a final common pathway in this process. Although many regulators of the neovascular process have been identified, the complete role of the insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) appears to be significantly more complex. In this study, we used an oxygen-induced retinopathy (OIR) mouse model as well as an in vitro model of hypoxia to study the role of MMP-2 derived from Müller glial cells (MGCs) and its relation with the IGF-1/IGF-1R system. We demonstrated that MMP-2 protein expression increased in P17 OIR mice, which coincided with the active phase of the neovascular process. Also, glutamine synthetase (GS)-positive cells were also positive for MMP-2, whereas IGF-1R was expressed by GFAP-positive cells, indicating that both proteins were expressed in MGCs. In addition, in the OIR model a single intravitreal injection of the IGF-1R blocking antibody (αIR3) administered at P12 effectively prevented pathologic neovascularization, accelerated physiological revascularization, and improved retinal functionality at P17. Finally, in MGC supernatants, the blocking antibody abolished the IGF-1 effect on active MMP-2 under normoxic and hypoxic conditions without affecting the extracellular levels of pro-MMP-2. These results demonstrate, for the first time, that the IGF-1/IGF-1R system regulates active MMP-2 levels in MGCs, thus contributing to MEC remodeling during the retinal neovascular process.

Asymptomatic infections in blood donors harbouring Plasmodium: an invisible risk detected by molecular and serological tools.

BACKGROUND: Transfusion-transmitted malaria due to asymptomatic Plasmodium infections is a challenge for blood banks. There is a lack of data on the prevalence of asymptomatic infected blood donors and the incidence of transfusion-transmitted malaria in low endemicity areas worldwide. We estimated the frequency of blood donors harbouring Plasmodium in an area in which asymptomatic infections have been reported. MATERIAL AND METHODS: To estimate the frequency of blood donors harbouring Plasmodium we used microscopy and molecular tools. Serological tests were applied to measure the exposure of candidates to Plasmodium antigens. Venous blood was collected from 91 candidates attending the "Pró-Sangue" Blood Centre Foundation in São Paulo, who lived in the municipality of Juquitiba, São Paulo, Brazil, where sporadic autochthonous cases of malaria have been described. Blood samples were used for parasitological, molecular and serological studies. RESULTS: Among the 91 samples examined, rare Plasmodium forms were observed in two donors. Genus real-time polymerase chain reaction analysis demonstrated Plasmodium amplification in three candidates and species-specific nested polymerase chain reaction identified P. malariae in two. ELISA-IgG was reactive in 42.9% of samples for P. vivax (Pv-MSP119) and in 6.6% for P. falciparum (Pf-Zw). ELISA-IgM was reactive in 2.2% of samples for P. vivax and in 4.4% for P. falciparum. An indirect immunofluorescence assay was reactive for P. malariae in 15.4% of cases. DISCUSSION: Reservoirs of Plasmodium represent a challenge for blood banks, since studies have shown that high levels of submicroscopic infections can occur in low transmission areas. The risk of transfusion-transmitted malaria presented here points to the need to conduct molecular investigations of candidate donors with any positive malarial antibody test.

Stomatal density, leaf area and plant size variation of Rhizophora mangle (Malpighiales: Rhizophoraceae) along a salinity gradient in the Mexican Caribbean / Variación en la densidad estomática, área foliar y tamaño de Rhizophora mangle (Malpighiales: Rhizophoraceae) a lo largo de un gradiente de salinidad en el Caribe Mexicano

AbstractIn community ecology, the knowledge of abiotic factors, that determine intraspecific variability in ecophysiological and functional traits, is important for addressing major questions, such as plant community assembly and ecosystem functioning. Mangroves have several mechanisms of resistance to salinity and most species exhibit some xeromorphic features in order to conserve water. Leaf area and stomatal density play an important role in maintaining water balance, and gas exchange is regulated by their aperture and density, two traits that vary intraspecifically in response to environmental conditions, such as water stress and salinity. In this study, we evaluated the effects of salinity on stomatal density, leaf area and plant size in R. mangle and we tested for associations among the three variables, across three sites along a natural salinity gradient in the XelHá Park, Quintana Roo, Mexico. We hypothesized that high salinity sites would produce smaller plants, with smaller leaves, and fewer stomata. Three sampling sites with different environmental conditions were chosen and salinities were monitored monthly. A total of 542 plants were tagged and tree heights and diameters were measured for each individual within each of the three sampling sites. Three leaves from 20 trees from each site were measured to determine leaf area. Stomatal densities were determined in each leaf using nail polish casts, examining ten 1 mm squares per leaf under an optical microscope. A principal component analysis was used to assess association between tree height, leaf area, and stomatal density for each plot. The salinity gradient was reflected in plant size, producing smaller plants at the higher salinity site. The largest leaves were found at the low salinity site (51.2 ± 24.99 cm2). Leaf length was not correlated to plant size (LL vs. tree height: r= 0.02, P= 0.8205; LL vs. trunk diameter: r= 0.03, P= 0.7336), so we concluded that leaf length is an environmentally plastic trait of red mangroves that may vary as a function of environmental conditions, such as hydric stress caused by elevated salinity. The larger leaves from the low salinity site had lower densities of stomata (65.0 stomata.mm2 SD= 12.3), and increasing salinities did not decrease stomatal density (intermediate salinity site: 73.4 stomata.mm2 SD= 13.5; high salinity site: 74.8 stomata.mm2 SD= 17.3). Our results confirm that stomatal density is inversely related to leaf area (r= -0.29, P < 0.001), especially leaf width (r= -0.31, P < 0.001), and that salinity may increase stomatal density by causing reduction of leaf size.

ResumenLos manglares tienen varios mecanismos de resistencia salina y la mayoría de las especies presentan algunas características xeromórficas con el fin de conservar el agua. El tamaño de la hoja y la densidad de los estomas desempeñan un papel importante en el mantenimiento del equilibrio hídrico. El intercambio de gases puede mediarse mediante la regulación de la apertura de los estomas, así como el número de estomas sobre la epidermis, dos características que pueden variar intraespecíficamente en función las condiciones ambientales, tales como el estrés hídrico. Rhizophora mangle es una de las especies de mayor importancia en América del Norte y Sur, y de África occidental. El objetivo de este trabajo fue evaluar los efectos de la salinidad sobre la densidad de los estomas, el tamaño de la hoja y el tamaño de las plantas de Rhizophora mangle y determinar si existe una relación entre las tres variables, comparándose tres ambientes diferentes a lo largo de un gradiente natural de salinidad en Xel-Há, Quintana Roo, México. La hipótesis fue que los ambientes de alta salinidad producirían plantas más pequeñas, con hojas más pequeñas y menos estomas. Se seleccionaron tres sitios de estudio con condiciones ambientales diferentes y se midió la salinidad cada mes. Un total de 542 plantas fueron etiquetadas en los tres sitios, y se midió su altura y diámetro del tronco. Se recolectaron tres hojas de 20 árboles en cada uno de los sitios, y se obtuvo el área de cada hoja. La densidad estomática se midió mediante la técnica de microrelieve con barniz de uñas, observando diez 1 mm cuadrados bajo un microscopio óptico. Se utilizó un análisis de componentes principales para determinar la asociación entre altura de árbol, área de hoja y densidad estomática. El gradiente de salinidad se vio reflejado en el tamaño de las plantas, produciendo plantas más pequeñas en el sitio de alta salinidad. El largo de las hojas no se correlacionó con el tamaño de las plantas, por lo cual se concluyó que esta variable tiene plasticidad ambiental particular. Las hojas más grandes fueron encontradas en el sitio de baja salinidad y tuvieron densidades estomáticas menores. No se pudo observar que la densidad de estomas disminuyera con las altas salinidades. Estos resultados confirman que la densidad estomática es inversamente relacionada con el tamaño de la hoja, especialmente el ancho, y que la densidad estomática incrementa con la salinidad debido a la reducción del tamaño de hoja.