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1.
Int J Mol Sci ; 25(14)2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39062775

RESUMO

Breast cancer (BC) stands out as the most commonly type of cancer diagnosed in women worldwide, and chemotherapy, a key component of treatment, exacerbates cancer-induced skeletal muscle wasting, contributing to adverse health outcomes. Notably, the impact of chemotherapy on skeletal muscle seems to surpass that of the cancer itself, with inflammation identified as a common trigger for muscle wasting in both contexts. In skeletal muscle, pro-inflammatory cytokines modulate pathways crucial for the delicate balance between protein synthesis and breakdown, as well as satellite cell activation and myonuclear accretion. Physical exercise consistently emerges as a crucial therapeutic strategy to counteract cancer and chemotherapy-induced muscle wasting, ultimately enhancing patients' quality of life. However, a "one size fits all" approach does not apply to the prescription of exercise for BC patients, with factors such as age, menopause and comorbidities influencing the response to exercise. Hence, tailored exercise regimens, considering factors such as duration, frequency, intensity, and type, are essential to maximize efficacy in mitigating muscle wasting and improving disease outcomes. Despite the well-established anti-inflammatory role of aerobic exercise, resistance exercise proves equally or more beneficial in terms of mass and strength gain, as well as enhancing quality of life. This review comprehensively explores the molecular pathways affected by distinct exercise regimens in the skeletal muscle of cancer patients during chemotherapy, providing critical insights for precise exercise implementation to prevent skeletal muscle wasting.


Assuntos
Neoplasias da Mama , Exercício Físico , Músculo Esquelético , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Feminino , Músculo Esquelético/metabolismo , Músculo Esquelético/efeitos dos fármacos , Qualidade de Vida , Terapia por Exercício/métodos , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Atrofia Muscular/etiologia , Atrofia Muscular/metabolismo
2.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38612654

RESUMO

Kidney transplantation is an essential medical procedure that significantly enhances the survival rates and quality of life for patients with end-stage kidney disease. However, despite advancements in immunosuppressive therapies, allograft rejection remains a leading cause of organ loss. Notably, predictions of cellular rejection processes primarily rely on biopsy analysis, which is not routinely performed due to its invasive nature. The present work evaluates if the serum proteomic fingerprint, as acquired by Fourier Transform Infrared (FTIR) spectroscopy, can predict cellular rejection processes. We analyzed 28 serum samples, corresponding to 17 without cellular rejection processes and 11 associated with cellular rejection processes, as based on biopsy analyses. The leave-one-out-cross validation procedure of a Naïve Bayes model enabled the prediction of cellular rejection processes with high sensitivity and specificity (AUC > 0.984). The serum proteomic profile was obtained in a high-throughput mode and based on a simple, rapid, and economical procedure, making it suitable for routine analyses and large-scale studies. Consequently, the current method presents a high potential to predict cellular rejection processes translatable to clinical scenarios, and that should continue to be explored.


Assuntos
Transplante de Rim , Humanos , Teorema de Bayes , Proteômica , Qualidade de Vida , Aloenxertos
3.
Calcif Tissue Int ; 114(3): 267-275, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38253933

RESUMO

Bone and mineral metabolism abnormalities are frequent in kidney transplant recipients and have been associated with cardiovascular morbidity. The primary aim of this study was to analyse the association between routine clinically available biochemical evaluation, non-routine histomorphometric bone evaluation, and vascular disease in kidney transplanted patients. A cross-sectional analysis was performed on 69 patients, 1-year after kidney transplantation. Laboratory analysis, radiography of hands and pelvis, bone biopsy, bone densitometry, and coronary CT were performed. One-year post-transplantation, nearly one-third of the patients presented with hypercalcemia, 16% had hypophosphatemia, 39.3% had iPTH levels > 150 pg/mL, 20.3% had BALP levels > 40 U/L, and 26.1% had hypovitaminosis D. Evaluation of extraosseous calcifications revealed low Adragão and Agatston scores. We divided patients into three clusters, according to laboratory results routinely used in clinical practice: hypercalcemia and hyperparathyroidism (Cluster1); hypercalcemia and high BALP levels (Cluster2); hypophosphatemia and vitamin D deficiency (Cluster 3). Patients in clusters 1 and 2 had higher cortical porosity (p = 0.001) and osteoid measurements, although there was no difference in the presence of abnormal mineralization, or low volume. Patients in cluster 2 had a higher BFR/BS (half of the patients in cluster 2 had high bone turnover), and most patients in cluster 1 had low or normal bone turnover. Cluster 3 has no differences in volume, or turnover, but 60% of the patients presented with pre-osteomalacia. All three clusters were associated with high vascular calcifications scores. Vascular calcifications scores were not related to higher bone mineral density. Instead, an association was found between a higher Adragão score and the presence of osteoporosis at the femoral neck (p = 0.008). In conclusion, inferring bone TMV by daily clinical biochemical analysis can be misleading, and bone biopsy is important for assessing both bone turnover and mineralization after kidney transplantation, although hypophosphatemia combined with vitamin D deficiency is associated with abnormal mineralization. The presence of hypercalcemia with high levels of PTH or high levels of BALP, or hypophosphatemia and vitamin D deficiency should remind us to screen vascular calcification status of patients.Clinical Research: ClinicalTrials.gov ID NCT02751099.


Assuntos
Hipercalcemia , Hipofosfatemia , Transplante de Rim , Calcificação Vascular , Deficiência de Vitamina D , Humanos , Estudos Transversais , Remodelação Óssea , Deficiência de Vitamina D/complicações , Biópsia , Calcificação Vascular/complicações , Densidade Óssea , Hormônio Paratireóideo
4.
Nanoscale ; 15(45): 18212-18217, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37933179

RESUMO

Herein, we investigate the bioactivity of small extracellular vesicles (sEVs), focusing on their local effect in the brain. sEVs from mononuclear cells (MNCs) showed superior effects in vitro to sEVs from mesenchymal stem cells (MSCs) and were able to promote neuroprotection and decrease microglia reactivity in a stroke mouse model.


Assuntos
Vesículas Extracelulares , Acidente Vascular Cerebral , Animais , Camundongos , Microglia , Neuroproteção , Encéfalo , Acidente Vascular Cerebral/terapia , Modelos Animais de Doenças
6.
Transplant Proc ; 55(6): 1441-1443, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37482436

RESUMO

Adenovirus infection in transplant recipients may present from asymptomatic viremia to multisystemic involvement. Most frequently, it occurs in the first year after a kidney transplant, and it is secondary to the reactivation of latent disease. However, primary infection may occur, and disseminated disease is more common when related to primary infection. Kidney involvement may be confirmed by biopsy, although diagnosis may be presumptive. Reduction of immunosuppression and supportive care are important components of therapy. CASE DESCRIPTION: A 41-year-old female renal-pancreatic recipient 12 years before with chronic renal graft dysfunction and a functional pancreatic graft had a history of cytomegalovirus and polyoma virus infection 2 years after transplantation. She was taking tacrolimus, mycophenolate mofetil, and prednisolone. The patient was admitted after persistent uncharacteristic diarrhea 3 weeks before hospitalization without any relevant epidemiologic context. She was dehydrated, and the lab results showed worsened kidney function and leucocytosis. The viral culture revealed adenovirus. Vigorous hydration was implemented, and the mycophenolate mofetil dose was reduced. The patient was discharged, and renal function returned to previous values. DISCUSSION AND CONCLUSION: Adenovirus infection has a wide clinical presentation, and multisystemic involvement may occur in transplant recipients. Supportive care is paramount. The clinical features and viral culture confirm the diagnosis, although tissue samples and quantitative polymerase chain reaction may be required in more severe cases.


Assuntos
Infecções por Adenoviridae , Imunossupressores , Feminino , Humanos , Adulto , Imunossupressores/efeitos adversos , Ácido Micofenólico/efeitos adversos , Transplantados , Rim/patologia , Infecções por Adenoviridae/diagnóstico , Rejeição de Enxerto
7.
Semin Dial ; 36(1): 29-36, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35262225

RESUMO

BACKGROUND: Low levels of 25-hydroxyvitamin D [25(OH)D] are frequent in chronic kidney disease and are associated with adverse outcomes. The aim of this 5-year prospective study was to evaluate the effects of cholecalciferol supplementation on mineral metabolism, inflammation and cardiac parameters in hemodialysis (HD) patients. METHODS: The study included 97 patients. Cholecalciferol was given after HD according to 25(OH)D baseline levels measured twice (end of winter and of summer). The 25(OH)D levels, circulating bone metabolism, inflammation parameters, brain natriuretic peptide (BNP), pulse pressure (PP), and left ventricular mass index (LVMI) were evaluated before and after supplementation. RESULTS: There was a significant increase in 25(OH)D levels after supplementation (p < 0.001); however, serum calcium (p = 0.02), phosphorus (p = 0.018), and iPTH (p = 0.03) were decreased. Magnesium levels increased during the study (p = 0.03). A reduction in the number of patients under active vitamin D (p < 0.001) and in the dose and number of patients treated with darbepoetin (p = 0.02) was observed. Serum albumin increased (p < 0.001), and C-reactive protein decreased (p = 0.01). BNP (p < 0.001), PP (p = 0.007), and LVMI (p = 0.02) were significantly reduced after supplementation. CONCLUSIONS: Long-term cholecalciferol supplementation allowed correction of 25(OH)D deficiency, improved mineral metabolism with less use of active vitamin D, attenuated inflammation, reduced the dose of the erythropoiesis-stimulating agent, and improved cardiac dysfunction.


Assuntos
Colecalciferol , Deficiência de Vitamina D , Humanos , Colecalciferol/uso terapêutico , Estudos Prospectivos , Diálise Renal/efeitos adversos , Vitamina D , Vitaminas , Inflamação/complicações , Suplementos Nutricionais , Minerais , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/tratamento farmacológico
9.
Transplantation ; 106(5): e251-e261, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35266925

RESUMO

BACKGROUND: Posttransplant mineral and bone diseases are causes of fractures, and their association with cardiovascular events is being studied. METHODS: We analyzed the evolution of biochemical, histological, and imaging parameters pre- and 1 y post-renal transplantation in 69 patients and correlated mineral and bone findings with coronary calcifications. At inclusion and after 12 mo, clinical data and echocardiographic findings were recorded, and laboratory evaluations, radiography of the pelvis and hands, and bone biopsy were performed. Noncontrast cardiac computed tomography was performed during the second evaluation. RESULTS: Serum levels of fibroblast growth factor 23 and sclerostin decreased in all patients, parathyroid hormone levels decreased in 89.8% of patients, bone alkaline phosphatase levels decreased in 68.1% of patients, and alpha-Klotho levels increased in 65.2% of patients. More than half of the patients presented with renal osteodystrophy at both biopsies, but histological findings improved: a significant transition from high to normal or low turnover and no significant differences in volume, mineralization defect, or cortical porosity at the 2 evaluations. Alpha-Klotho, sclerostin, and bone alkaline phosphatase shifts affect bone changes. Neither echocardiographic findings nor vascular calcification scores differed between the 2 points. Both the pretransplant period (dialysis vintage, sclerostin, and low bone volume at baseline) and the maintenance of abnormalities in the posttransplant period (high turnover posttransplant) were the most reliable predictors of the severity of the coronary calcification percentile. CONCLUSIONS: Renal transplantation improved bone and mineral abnormalities. The pretransplant period determines the severity of calcification.


Assuntos
Distúrbio Mineral e Ósseo na Doença Renal Crônica , Transplante de Rim , Fosfatase Alcalina , Densidade Óssea , Distúrbio Mineral e Ósseo na Doença Renal Crônica/diagnóstico por imagem , Distúrbio Mineral e Ósseo na Doença Renal Crônica/etiologia , Feminino , Humanos , Transplante de Rim/efeitos adversos , Masculino , Minerais , Hormônio Paratireóideo , Diálise Renal
10.
J Control Release ; 343: 469-481, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35131370

RESUMO

Retinal ganglion cell (RGC) loss underlies several conditions which give rise to significant visual compromise, including glaucoma and ischaemic optic neuropathies. Neuroprotection of RGCs is a clinical well-defined unmet need in these diseases, and adenosine A3 receptor (A3R) activation emerges as a therapeutic pharmacological approach to protect RGCs. A porous biodegradable intraocular implant loaded with 2-Cl-IB-MECA (selective A3R agonist) was used as a strategy to protect RGCs. Drug-loaded PCL implants released 2-Cl-IB-MECA for an extended period and the released 2-Cl-IB-MECA limited glutamate-evoked calcium (Ca2+) rise in RGCs. Retinal thinning due to transient ischemia was not prevented by 2-Cl-IB-MECA-PCL implant. However, 2-Cl-IB-MECA-PCL implants decreased retinal cell death, promoted the survival of RGCs, preserved optic nerve structure and anterograde axonal transport. We further demonstrated that 2-Cl-IB-MECA-loaded PCL implants were able to enhance RGC function that was compromised by transient ischemia. Taking into consideration the beneficial effects afforded by 2-Cl-IB-MECA released from the PCL implant, this can be envisaged a good therapeutic strategy to protect RGCs.


Assuntos
Agonistas do Receptor A3 de Adenosina , Células Ganglionares da Retina , Agonistas do Receptor A3 de Adenosina/farmacologia , Humanos , Isquemia/tratamento farmacológico , Receptor A3 de Adenosina/metabolismo , Retina/metabolismo
11.
Calcif Tissue Int ; 110(2): 215-224, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34477944

RESUMO

Chronic kidney disease-mineral and bone disorder has been associated with increasing morbid-mortality. The aim of this study was to determine the prevalence and phenotype of bone disease before transplantation and to correlate FGF23 and sclerostin levels with bone histomorphometry, and study possible associations between FGF23, sclerostin, and bone histomorphometry with cardiovascular disease and mortality. We performed a cross-sectional cohort study of a sample of 84 patients submitted to renal transplant, which were prospectively followed for 12 months. Demographic, clinical, and echocardiographic data were collected, laboratory evaluation, bone biopsy, and X-ray of the pelvis and hands were performed. Patient and graft survival were recorded. We diagnosed low bone turnover in 16 patients (19.5%); high bone turnover in 22 patients (26.8%); osteomalacia in 1 patient (1.2%), and mixed renal osteodystrophy in 3 patients (3.7%). At the end of 12 months, 5 patients had graft failure (5.9%), 4 had a cardiovascular event (4.8%), and 4 died. Age was associated with low remodeling disease, whereas high BALP and phosphorus and low sclerostin with high turnover disease. Sclerostin was a risk factor for isolated low bone volume. High BALP, low phosphorus, and low FGF23 were risk factors for abnormal mineralization. FGF23 appears as an independent factor for severity of vascular calcifications and for cardiovascular events, whereas the presence of valve calcifications was associated with low volume and with turnover deviations. Sclerostin was associated a higher HR for death. Sclerostin and FGF23 seemed to provide higher cardiovascular risk, as well as low bone volume, which associated with extra-osseous calcifications.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Densidade Óssea , Fator de Crescimento de Fibroblastos 23/metabolismo , Insuficiência Renal Crônica , Calcinose , Estudos de Coortes , Estudos Transversais , Marcadores Genéticos , Humanos , Insuficiência Renal Crônica/mortalidade
12.
Respir Med Case Rep ; 33: 101386, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34401253

RESUMO

A significant dysfunction of another organ is usually considered an absolute contraindication for lung transplantation, unless multiorgan transplantation is indicated and practical, as is the case of combined lung-kidney transplantation. Few cases of combined lung-kidney transplantation have been described in the literature; however, it is known that, in certain cases, it is the only way to offer an opportunity to selected patients with renal and lung dysfunction. The authors are not aware of any previously published case of a patient receiving both extracorporeal membrane oxygenation and continuous venovenous hemodiafiltration as a bridge for combined kidney-lung transplantation. The authors present the first case of combined lung-kidney transplantation performed in Portugal.

13.
Biomolecules ; 11(6)2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34063832

RESUMO

Microglial cells are the neuroimmune competent cells of the central nervous system. In the adult, microglia are responsible for screening the neuronal parenchyma searching for alterations in homeostasis. Chronic neuroinflammation plays a role in neurodegenerative disease. Indeed, microglia-mediated neuroinflammation is involved in the onset and progression of several disorders in the brain and retina. Microglial cell reactivity occurs in an orchestrated manner and propagates across the neural parenchyma spreading the neuroinflammatory signal from cell to cell. Extracellular vesicles are important vehicles of intercellular communication and act as message carriers across boundaries. Extracellular vesicles can be subdivided in several categories according to their cellular origin (apoptotic bodies, microvesicles and exosomes), each presenting, different but sometimes overlapping functions in cell communication. Mounting evidence suggests a role for extracellular vesicles in regulating microglial cell action. Herein, we explore the role of microglial extracellular vesicles as vehicles for cell communication and the mechanisms that trigger their release. In this review we covered the role of microglial extracellular vesicles, focusing on apoptotic bodies, microvesicles and exosomes, in the context of neurodegeneration and the impact of these vesicles derived from other cells in microglial cell reactivity.


Assuntos
Comunicação Celular , Vesículas Extracelulares/metabolismo , Microglia/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Vesículas Extracelulares/patologia , Humanos , Camundongos , Microglia/patologia , Doenças Neurodegenerativas/patologia
14.
Transpl Int ; 34(6): 1065-1073, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33909300

RESUMO

Bone loss leads to increase risk of fractures in renal transplantation. The aim of this study was to analyse the relationship between bone densitometry (DXA) findings, bone histomorphometry and bone-related molecules 1-year after renal transplantation. We performed a cross-sectional study of de novo renal transplanted patients that agreed to perform a bone biopsy and a DXA examination 1 year after transplantation. All patients underwent a laboratory evaluation, bone biopsy, DXA examination and cardiac CT 1 year after transplantation. 67 patients were included, 16 had a normal examination, and 18 patients were classified as having osteoporosis by DXA. Correlations between bone mineral density and T-scores of total femur and femoral neck were the ones that best correlated with bone volume assessed by a bone biopsy. The sensitivity of DXA for osteoporosis diagnosis was 47.0%, and the specificity was 81.2%. The positive predictive value was 50.0%, and the negative predictive value (NPV) was 80.0%. DXA parameters also correlated with klotho and sclerostin serum levels. In this population, a normal examination excluded the presence of osteoporosis, helping in identifying patients that would not benefit from therapy. Overall, densitometry in total femur and femoral neck correlated well with bone volume measured by bone biopsy.


Assuntos
Transplante de Rim , Absorciometria de Fóton , Densidade Óssea , Estudos Transversais , Colo do Fêmur/diagnóstico por imagem , Humanos , Transplante de Rim/efeitos adversos
15.
16.
Int J Mol Sci ; 21(19)2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33007835

RESUMO

Glaucoma is a progressive chronic retinal degenerative disease and a leading cause of global irreversible blindness, characterized by optic nerve damage and retinal ganglion cell (RGC) death. Elevated intraocular pressure (IOP) is a main risk factor of glaucoma. Neuroinflammation plays an important role in glaucoma. We have been demonstrating that elevated pressure triggers microglia reactivity that contribute to the loss of RGCs. Adenosine, acting on adenosine receptors, is a crucial modulator of microglia phenotype. Microglia express all adenosine receptors. Previously, we demonstrated that the activation of adenosine A3 receptor (A3R) affords protection to the retina, including RGCs, unveiling the possibility for a new strategy for glaucoma treatment. Since microglial cells express A3R, we now studied the ability of a selective A3R agonist (2-Cl-IB-MECA) in controlling microglia reactivity induced by elevated hydrostatic pressure (EHP), used to mimic elevated IOP. The activation of A3R reduced EHP-induced inducible nitric oxide synthase (iNOS) expression, microglia migration and phagocytosis in BV-2 cells. In retinal microglia, proliferation and phagocytosis elicited by EHP were also decreased by A3R activation. This work demonstrates that 2-Cl-IB-MECA, the selective agonist of A3R, is able to hinder microglia reactivity, suggesting that A3R agonists could afford protection against glaucomatous degeneration through the control of neuroinflammation.


Assuntos
Agonistas do Receptor A3 de Adenosina/farmacologia , Adenosina/análogos & derivados , Glaucoma/tratamento farmacológico , Receptor A3 de Adenosina/genética , Adenosina/genética , Adenosina/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Glaucoma/genética , Glaucoma/patologia , Humanos , Pressão Intraocular/efeitos dos fármacos , Microglia/efeitos dos fármacos , Nervo Óptico/efeitos dos fármacos , Nervo Óptico/patologia , Traumatismos do Nervo Óptico/tratamento farmacológico , Traumatismos do Nervo Óptico/genética , Traumatismos do Nervo Óptico/patologia , Fagocitose/efeitos dos fármacos , Ratos , Degeneração Retiniana/tratamento farmacológico , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/patologia
17.
Nephron ; 144(10): 479-487, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810846

RESUMO

INTRODUCTION: Chronic kidney disease (CKD) is a major global public health problem associated with increased risk of cardiovascular morbidity, premature mortality, and decreased quality of life. In Portugal, the PREVADIAB study showed a prevalence of CKD stages 3-5 of 6.1%. To overcome the limitations of the PREVADIAB study, the RENA study aimed to provide an estimate of the prevalence of CKD at a national level and to characterize CKD patients. METHODS: This was a cross-sectional study including users of Primary Health Care Units aged 18 or more. After obtaining written informed consent, sociodemographic and clinical data were recorded through a structured questionnaire, anthropometric measurements were taken, and blood and urine samples were collected. All participants initially meeting the criteria for CKD were contacted at least 3 months after the initial assessment for confirmation of the analytical results. RESULTS: A total of 3,135 individuals were included, 65.4% were female, and the mean age was 56.7 ± 15.9 years. The prevalence of hypertension, dyslipidemia, and diabetes was 38, 32, and 16%, respectively, and 31% were obese. After data adjustment by gender, age group, and geographical region, the global prevalence of CKD was 20.9% (95% CI: 6.5-35.3%), with no differences between genders and a significant increase with the advance of the age groups. CONCLUSION: Our study showed a CKD prevalence above the worldwide and Europe average. Despite the study limitations, it has become clear that it is urgent to identify CKD patients earlier and to develop awareness and educational programs to prevent CKD and its associated diseases.


Assuntos
Insuficiência Renal Crônica/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Prevalência , Insuficiência Renal Crônica/diagnóstico , Fatores de Risco , Adulto Jovem
18.
Glia ; 68(12): 2705-2724, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32645245

RESUMO

Glaucoma is a degenerative disease that causes irreversible loss of vision and is characterized by retinal ganglion cell (RGC) loss. Others and we have demonstrated that chronic neuroinflammation mediated by reactive microglial cells plays a role in glaucomatous pathology. Exosomes are extracellular vesicles released by most cells, including microglia, that mediate intercellular communication. The role of microglial exosomes in glaucomatous degeneration remains unknown. Taking the prominent role of microglial exosomes in brain neurodegenerative diseases, we studied the contribution of microglial-derived exosomes to the inflammatory response in experimental glaucoma. Microglial cells were exposed to elevated hydrostatic pressure (EHP), to mimic elevated intraocular pressure, the main risk factor for glaucoma. Naïve microglia (BV-2 cells or retinal microglia) were exposed to exosomes derived from BV-2 cells under EHP conditions (BV-Exo-EHP) or cultured in control pressure (BV-Exo-Control). We found that BV-Exo-EHP increased the production of pro-inflammatory cytokines, promoted retinal microglia motility, phagocytic efficiency, and proliferation. Furthermore, the incubation of primary retinal neural cell cultures with BV-Exo-EHP increased cell death and the production of reactive oxygen species. Exosomes derived from retinal microglia (MG-Exo-Control or MG-Exo-EHP) were injected in the vitreous of C57BL/6J mice. MG-Exo-EHP sustained activation of retinal microglia, mediated cell death, and impacted RGC number. Herein, we show that exosomes derived from retinal microglia have an autocrine function and propagate the inflammatory signal in conditions of elevated pressure, contributing to retinal degeneration in glaucomatous conditions.


Assuntos
Exossomos , Glaucoma , Animais , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Microglia , Células Ganglionares da Retina
19.
Cell Death Dis ; 11(5): 401, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32461578

RESUMO

Glaucoma is a progressive chronic retinal degenerative disease and a leading cause of global irreversible blindness. This disease is characterized by optic nerve damage and retinal ganglion cell (RGC) death. The current treatments available target the lowering of intraocular pressure (IOP), the main risk factor for disease onset and development. However, in some patients, vision loss progresses despite successful IOP control, indicating that new and effective treatments are needed, such as those targeting the neuroprotection of RGCs. Adenosine A3 receptor (A3R) activation confers protection to RGCs following an excitotoxic stimulus. In this work, we investigated whether the activation of A3R could also afford protection to RGCs in the laser-induced ocular hypertension (OHT) model, a well-characterized animal model of glaucoma. The intravitreal injection of 2-Cl-IB-MECA, a selective A3R agonist, abolished the alterations induced by OHT in the negative and positive components of scotopic threshold response (STR) without changing a- and b-wave amplitudes both in scotopic and photopic conditions. Moreover, the treatment of OHT eyes with the A3R agonist promoted the survival of RGCs, attenuated the impairment in retrograde axonal transport, and improved the structure of the optic nerve. Taking into consideration the beneficial effects afforded by 2-Cl-IB-MECA, we can envisage that A3R activation can be considered a good therapeutic strategy to protect RGCs from glaucomatous damage.


Assuntos
Neuroproteção , Hipertensão Ocular/complicações , Receptor A3 de Adenosina/metabolismo , Degeneração Retiniana/etiologia , Células Ganglionares da Retina/patologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A3 de Adenosina/farmacologia , Animais , Transporte Axonal/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Neuroproteção/efeitos dos fármacos , Nervo Óptico/efeitos dos fármacos , Nervo Óptico/patologia , Nervo Óptico/ultraestrutura , Ratos Sprague-Dawley , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/ultraestrutura , Regulação para Cima/efeitos dos fármacos
20.
Int J Mol Sci ; 21(7)2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32218163

RESUMO

The retinal ganglion cells (RGCs) are the output cells of the retina into the brain. In mammals, these cells are not able to regenerate their axons after optic nerve injury, leaving the patients with optic neuropathies with permanent visual loss. An effective RGCs-directed therapy could provide a beneficial effect to prevent the progression of the disease. Axonal injury leads to the functional loss of RGCs and subsequently induces neuronal death, and axonal regeneration would be essential to restore the neuronal connectivity, and to reestablish the function of the visual system. The manipulation of several intrinsic and extrinsic factors has been proposed in order to stimulate axonal regeneration and functional repairing of axonal connections in the visual pathway. However, there is a missing point in the process since, until now, there is no therapeutic strategy directed to promote axonal regeneration of RGCs as a therapeutic approach for optic neuropathies.


Assuntos
Fármacos Neuroprotetores/farmacologia , Células Ganglionares da Retina/citologia , Animais , Diferenciação Celular , Terapia Baseada em Transplante de Células e Tecidos , Ensaios Clínicos como Assunto , Progressão da Doença , Humanos , Células Ganglionares da Retina/efeitos dos fármacos
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