RESUMEN
The Golgi apparatus, the main glycosylation station of the cell, consists of a stack of discontinuous cisternae. Glycosylation enzymes are usually concentrated in one or two specific cisternae along the cis-trans axis of the organelle. How such compartmentalized localization of enzymes is achieved and how it contributes to glycosylation are not clear. Here, we show that the Golgi matrix protein GRASP55 directs the compartmentalized localization of key enzymes involved in glycosphingolipid (GSL) biosynthesis. GRASP55 binds to these enzymes and prevents their entry into COPI-based retrograde transport vesicles, thus concentrating them in the trans-Golgi. In genome-edited cells lacking GRASP55, or in cells expressing mutant enzymes without GRASP55 binding sites, these enzymes relocate to the cis-Golgi, which affects glycosphingolipid biosynthesis by changing flux across metabolic branch points. These findings reveal a mechanism by which a matrix protein regulates polarized localization of glycosylation enzymes in the Golgi and controls competition in glycan biosynthesis.
Asunto(s)
Glicoesfingolípidos/metabolismo , Aparato de Golgi/metabolismo , Proteínas de la Matriz de Golgi/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Autoantígenos/genética , Autoantígenos/metabolismo , Brefeldino A/farmacología , Ceramidas/metabolismo , Toxina del Cólera/farmacología , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Expresión Génica , Glicosilación/efectos de los fármacos , Aparato de Golgi/efectos de los fármacos , Aparato de Golgi/genética , Proteínas de la Matriz de Golgi/genética , Células HeLa , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Toxina Shiga/farmacologíaRESUMEN
Glycosphingolipids are important components of the plasma membrane where they modulate the activities of membrane proteins including signalling receptors. Glycosphingolipid synthesis relies on competing reactions catalysed by Golgi-resident enzymes during the passage of substrates through the Golgi cisternae. The glycosphingolipid metabolic output is determined by the position and levels of the enzymes within the Golgi stack, but the mechanisms that coordinate the intra-Golgi localisation of the enzymes are poorly understood. Here, we show that a group of sequentially-acting enzymes operating at the branchpoint among glycosphingolipid synthetic pathways binds the Golgi-localised oncoprotein GOLPH3. GOLPH3 sorts these enzymes into vesicles for intra-Golgi retro-transport, acting as a component of the cisternal maturation mechanism. Through these effects, GOLPH3 controls the sub-Golgi localisation and the lysosomal degradation rate of specific enzymes. Increased GOLPH3 levels, as those observed in tumours, alter glycosphingolipid synthesis and plasma membrane composition thereby promoting mitogenic signalling and cell proliferation. These data have medical implications as they outline a novel oncogenic mechanism of action for GOLPH3 based on glycosphingolipid metabolism.
Asunto(s)
Proliferación Celular , Glicoesfingolípidos/biosíntesis , Aparato de Golgi/metabolismo , Proteínas de la Membrana/metabolismo , Células Cultivadas , Células HeLa , Humanos , Lisosomas/metabolismo , Proteínas de la Membrana/genética , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Transducción de SeñalRESUMEN
Investigating the evaluation of eligibility for transplant in myelofibrosis (MF): The role of HCT-CI and BMI. HCT-CI emerges as a key prognostic factor, while BMI shows limited impact. This study expands insights for better clinical decision-making in MF allo-HCT.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Neoplasias , Mielofibrosis Primaria , Humanos , Índice de Masa Corporal , Mielofibrosis Primaria/terapia , Estudios Retrospectivos , Acondicionamiento PretrasplanteRESUMEN
The human fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) axis deregulation is largely involved in supporting the pathogenesis of hematologic malignancies, including Waldenström macroglobulinemia (WM). WM is still an incurable disease, and patients succumb because of disease progression. Therefore, novel therapeutics designed to specifically target deregulated signaling pathways in WM are required. We aimed to investigate the role of FGF/FGFR system blockade in WM by using a pan-FGF trap molecule (NSC12). Wide-transcriptome profiling confirmed inhibition of FGFR signaling in NSC12-treated WM cells; unveiling a significant inhibition of MYD88 was also confirmed at the protein level. Importantly, the NSC12-dependent silencing of MYD88 was functionally active, as it led to inhibition of MYD88-driven pathways, such as BTK and SYK, as well as the MYD88-downstream target HCK. Of note, both canonical and noncanonical NF-κB cascades were downregulated in WM cells upon NSC12 treatment. Functional sequelae exerted by NSC12 in WM cells were studied, demonstrating significant inhibition of WM cell growth, induction of WM cell apoptosis, halting MAPK, JAK/STAT3, and PI3K-Akt pathways. Importantly, NSC12 exerted an anti-WM effect even in the presence of bone marrow microenvironment, both in vitro and in vivo. Our studies provide the evidence for using NSC12 as a specific FGF/FGFR system inhibitor, thus representing a novel therapeutic strategy in WM.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Colesterol/análogos & derivados , Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factor 88 de Diferenciación Mieloide/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Macroglobulinemia de Waldenström/prevención & control , Animales , Apoptosis , Biomarcadores de Tumor/genética , Proliferación Celular , Colesterol/farmacología , Perfilación de la Expresión Génica , Humanos , Ratones , Transducción de Señal , Células Tumorales Cultivadas , Microambiente Tumoral , Macroglobulinemia de Waldenström/genética , Macroglobulinemia de Waldenström/metabolismo , Macroglobulinemia de Waldenström/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Neural development is accomplished by differentiation events leading to metabolic reprogramming. Glycosphingolipid metabolism is reprogrammed during neural development with a switch from globo- to ganglio-series glycosphingolipid production. Failure to execute this glycosphingolipid switch leads to neurodevelopmental disorders in humans, indicating that glycosphingolipids are key players in this process. Nevertheless, both the molecular mechanisms that control the glycosphingolipid switch and its function in neurodevelopment are poorly understood. Here, we describe a self-contained circuit that controls glycosphingolipid reprogramming and neural differentiation. We find that globo-series glycosphingolipids repress the epigenetic regulator of neuronal gene expression AUTS2. AUTS2 in turn binds and activates the promoter of the first and rate-limiting ganglioside-producing enzyme GM3 synthase, thus fostering the synthesis of gangliosides. By this mechanism, the globo-AUTS2 axis controls glycosphingolipid reprogramming and neural gene expression during neural differentiation, which involves this circuit in neurodevelopment and its defects in neuropathology.
Asunto(s)
Diferenciación Celular/fisiología , Reprogramación Celular/fisiología , Glicoesfingolípidos/metabolismo , Neurogénesis/fisiología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Reprogramación Celular/efectos de los fármacos , Proteínas del Citoesqueleto , Epigenómica , Gangliósidos/metabolismo , Expresión Génica , Silenciador del Gen , Glicoesfingolípidos/farmacología , Células HeLa , Histonas/metabolismo , Humanos , Trastornos del Neurodesarrollo , Neurogénesis/efectos de los fármacos , Neurogénesis/genética , Neuronas/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Proteínas/genética , Proteínas/metabolismo , Sialiltransferasas/genética , Sialiltransferasas/metabolismo , Factores de TranscripciónRESUMEN
The phase III study was designed to compare event-free survival (EFS) after treosulfan-based conditioning with a widely applied reduced-intensity conditioning (RIC) busulfan regimen in older or comorbid patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic cell transplantation (HCT). A previously reported confirmatory interim analysis of the randomized clinical study including 476 patients demonstrated statistically significant noninferiority for treosulfan with clinically meaningful improvement in EFS. Here, the final study results and pre-specified subgroup analyses of all 570 randomized patients with completed longer-term follow-up are presented. Patients presenting HCT-specific comorbidity index >2 or aged ≥50 years were randomly assigned (1:1) to intravenous (IV) fludarabine with either treosulfan (30 g/m2 IV) or busulfan (6.4 mg/kg IV) after stratification by disease risk group, donor type, and participating institution. The primary endpoint was EFS with disease recurrence, graft failure, or death from any cause as events. EFS of patients (median age 60 years) was superior after treosulfan compared to RIC busulfan: 36-months-EFS rate 59.5% (95% CI, 52.2-66.1) vs. 49.7% (95% CI, 43.3-55.7) with a hazard ratio (HR) of 0.64 (95% CI, 0.49-0.84), p = 0.0006. Likewise, overall survival (OS) with treosulfan was superior compared to busulfan: 36-month-OS rate 66.8% vs. 56.3%; HR 0.64 (95% CI, 0.48-0.87), p = 0.0037. Post hoc analyses revealed that these differences were consistent with the confirmatory interim analysis, and thereby the treosulfan regimen appears particularly suitable for older AML and MDS patients.
Asunto(s)
Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Anciano , Busulfano/análogos & derivados , Busulfano/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Acondicionamiento Pretrasplante/métodos , Vidarabina/uso terapéuticoRESUMEN
BACKGROUND: In patients with relapsed/refractory acute myeloid leukaemia (R/R AML) who received salvage chemotherapy, limited and not updated studies explored the incidence of invasive aspergillosis (IA) and the role of antifungal prophylaxis (AP). The aims of this multicentre retrospective 'SEIFEM 2016-B' study were as follows: (1) to evaluate the current rate and the outcome of proven/probable IA and (2) to assess the efficacy of AP, in a large 'real life' series of patient with R/R AML submitted to salvage chemotherapy. RESULTS: Of 2250 R/R AML patients, a total of 74 cases of IA (5.1%) were recorded as follows: 10 (0.7%) proven and 64 (4.3%) probable. Information about AP were available in 73/74 (99%) patients. Fifty-eight (79%) breakthrough infections occurred, mainly during AP with posaconazole [25 (43%)]. The patients who received AP during salvage chemotherapy showed a benefit from antifungal therapy (AT) than patients who did not received AP [43 (86%) vs 7 (14%); p < .033]. In a multivariate analysis, AP and absence of severe mucositis had a significant favourable effect on overall response rate. CONCLUSION: Our data demonstrated that the incidence of IA during the salvage chemotherapy is similar to the past. Nevertheless, the attributable mortality rate (AMR) appears to be lower than that previously reported in R/R AML. Further prospective studies should be performed to confirm our preliminary observation and understand and the why a decreased AMR is reported in this setting of high-risk patients.
Asunto(s)
Antifúngicos , Aspergilosis , Infecciones Fúngicas Invasoras , Leucemia Mieloide Aguda , Antifúngicos/uso terapéutico , Aspergilosis/tratamiento farmacológico , Aspergilosis/epidemiología , Humanos , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Infecciones Fúngicas Invasoras/epidemiología , Leucemia Mieloide Aguda/complicaciones , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/microbiología , Estudios RetrospectivosRESUMEN
A great promise for tissue engineering is represented by scaffolds that host stem cells during proliferation and differentiation and simultaneously replace damaged tissue while maintaining the main vital functions. In this paper, a novel process was adopted to develop composite scaffolds with a core-shell structure for bone tissue regeneration, in which the core has the main function of temporary mechanical support, and the shell enhances biocompatibility and provides bioactive properties. An interconnected porous core was safely obtained, avoiding solvents or other chemical issues, by blending poly(lactic acid), poly(ε-caprolactone) and leachable superabsorbent polymer particles. After particle leaching in water, the core was grafted with a gelatin/chitosan hydrogel shell to create a cell-friendly bioactive environment within its pores. The physicochemical, morphological, and mechanical characterization of the hybrid structure and of its component materials was carried out by means of infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and mechanical testing under different loading conditions. These hybrid polymer devices were found to closely mimic both the morphology and the stiffness of bones. In addition, in vitro studies showed that the core-shell scaffolds are efficiently seeded by human mesenchymal stromal cells, which remain viable, proliferate, and are capable of differentiating towards the osteogenic phenotype if adequately stimulated.
Asunto(s)
Polímeros , Andamios del Tejido , Regeneración Ósea , Huesos , Poliésteres/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/químicaRESUMEN
Letermovir (LMV) inhibits HCMV replication by binding to components of the HCMV-terminase complex showing a potential role in prevention of HCMV-related complications in allogenic hematopoietic stem cell transplant recipients (allo-HSCTRs). However, little is known about breakthrough HCMV infection and the relevance of HCMV DNAemia during prophylaxis. We reported the results of a multicenter prospective study involving five Italian centers in the management of HCMV DNAemia in 75 adult HCMV-seropositive allo-HSCTRs undergoing LMV prophylaxis. The aim of the present study was to characterize the presence of real HCMV reactivation during LMV prophylaxis. Then, the presence of circulating infectious HCMV particles was determined by virus isolation and degradation of free-floating viral DNA. This report provides the first evidence that during LMV prophylaxis the clinical relevance of HCMV DNAemia should be critically considered.
Asunto(s)
Antivirales , Citomegalovirus , Acetatos , Antivirales/uso terapéutico , Citomegalovirus/genética , ADN Viral/genética , Estudios Prospectivos , Quinazolinas , Células MadreRESUMEN
Sphingolipids are membrane lipids globally required for eukaryotic life. The sphingolipid content varies among endomembranes with pre- and post-Golgi compartments being poor and rich in sphingolipids, respectively. Due to this different sphingolipid content, pre- and post-Golgi membranes serve different cellular functions. The basis for maintaining distinct subcellular sphingolipid levels in the presence of membrane trafficking and metabolic fluxes is only partially understood. Here, we describe a homeostatic regulatory circuit that controls sphingolipid levels at the trans-Golgi network (TGN). Specifically, we show that sphingomyelin production at the TGN triggers a signalling pathway leading to PtdIns(4)P dephosphorylation. Since PtdIns(4)P is required for cholesterol and sphingolipid transport to the trans-Golgi network, PtdIns(4)P consumption interrupts this transport in response to excessive sphingomyelin production. Based on this evidence, we envisage a model where this homeostatic circuit maintains a constant lipid composition in the trans-Golgi network and post-Golgi compartments, thus counteracting fluctuations in the sphingolipid biosynthetic flow.
Asunto(s)
Fosfatidilinositoles/metabolismo , Esfingolípidos/metabolismo , Red trans-Golgi/metabolismo , Células HeLa , Homeostasis , Humanos , Modelos BiológicosRESUMEN
Ruxolitinib (RUX), the first JAK1/JAK2 inhibitor approved for myelofibrosis (MF) therapy, has recently been associated with the occurrence of second primary malignancies (SPMs), mainly lymphomas and non-melanoma skin cancers (NMSCs). We analyzed the incidence, risk factors and outcome of SPMs in 700 MF patients treated with RUX in a real-world context. Median follow-up from starting RUX was 2·9 years. Overall, 80 (11·4%) patients developed 87 SPMs after RUX start. NMSCs were the most common SPMs (50·6% of the cases). Multivariate analysis demonstrated that male sex [hazard ratio (HR): 2·37, 95% confidence interval (95%CI): 1·22-4·60, P = 0·01] and thrombocytosis> 400 × 109 /l at RUX start (HR:1·98, 95%CI: 1·10-4·60, P = 0·02) were associated with increased risk for SPMs. Risk factors for NMSC alone were male sex (HR: 3·14, 95%CI: 1·24-7·92, P = 0·02) and duration of hydroxycarbamide and RUX therapy > 5 years (HR: 3·20, 95%CI: 1·17-8·75, P = 0·02 and HR: 2·93, 95%CI: 1·39-6·17, P = 0·005 respectively). In SPMs excluding NMSCs, male sex (HR: 2·41, 95%CI: 1·11-5·25, P = 0·03), platelet > 400 × 109 /l (HR: 3·30, 95%CI: 1·67-6·50, P = 0·001) and previous arterial thromboses (HR: 3·47, 95%CI: 1·48-8·14, P = 0·004) were shown to be associated with higher risk of SPMs. While it is reassuring that no aggressive lymphoma was documented, active skin surveillance is recommended in all patients and particularly after prolonged hydroxycaramide therapy; oncological screening should be triggered by thrombocytosis and arterial thrombosis, particularly in males.
Asunto(s)
Inhibidores de las Cinasas Janus/efectos adversos , Neoplasias Primarias Secundarias/inducido químicamente , Mielofibrosis Primaria/tratamiento farmacológico , Pirazoles/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Arterias/patología , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Inhibidores de las Cinasas Janus/administración & dosificación , Inhibidores de las Cinasas Janus/uso terapéutico , Inhibidores de las Cinasas Janus/toxicidad , Linfoma/diagnóstico , Linfoma/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neoplasias Primarias Secundarias/epidemiología , Neoplasias Primarias Secundarias/patología , Nitrilos , Mielofibrosis Primaria/patología , Pirazoles/administración & dosificación , Pirazoles/uso terapéutico , Pirazoles/toxicidad , Pirimidinas , Estudios Retrospectivos , Factores de Riesgo , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/epidemiología , Trombocitosis/inducido químicamente , Trombocitosis/diagnóstico , Trombosis/inducido químicamente , Trombosis/diagnósticoRESUMEN
Myeloproliferative neoplasms (MPN) are chronic, clonal hematologic malignancies characterized by myeloproliferation and a high incidence of vascular complications (thrombotic and bleeding). Although MPN-specific driver mutations have been identified, the underlying events that culminate in these clinical manifestations require further clarification. We reviewed the numerous studies performed during the last decade identifying endothelial cell (EC) dysregulation as a factor contributing to MPN disease development. The JAK2V617F MPN mutation and other myeloid-associated mutations have been detected not only in hematopoietic cells but also in EC and their precursors in MPN patients, suggesting a link between mutated EC and the high incidence of vascular events. To date, however, the role of EC in MPN continues to be questioned by some investigators. In order to further clarify the role of EC in MPN, we first describe the experimental strategies used to study EC biology and then analyze the available evidence generated using these assays which implicate mutated EC in MPN-associated abnormalities. Mutated EC have been reported to possess a pro-adhesive phenotype as a result of increased endothelial Pselectin exposure, secondary to degranulation of Weibel-Palade bodies, which is further accentuated by exposure to pro-inflammatory cytokines. Additional evidence indicates that MPN myeloproliferation requires JAK2V617F expression by both hematopoietic stem cells and EC. Furthermore, the reports of JAK2V617F and other myeloid malignancy- associated mutations in both hematopoietic cells and EC in MPN patients support the hypothesis that MPN driver mutations may first appear in a common precursor cell for both EC and hematopoietic cells.
Asunto(s)
Neoplasias Hematológicas , Trastornos Mieloproliferativos , Células Endoteliales/metabolismo , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Células Madre Hematopoyéticas/metabolismo , Humanos , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo , Mutación , Trastornos Mieloproliferativos/metabolismoRESUMEN
The role of spleen size and splenectomy for the prediction of post-allogeneic hematopoietic stem cell transplant (allo-HCT) outcome in myelofibrosis remains under debate. In EBMT registry, we identified a cohort of 1195 myelofibrosis patients transplanted between 2000-2017 after either fludarabine-busulfan or fludarabine-melphalan regimens. Overall, splenectomy was performed in 202 (16.9%) patients and its use decreased over time (28.3% in 2000-2009 vs 14.1% in 2010-2017 period). By multivariate analysis, splenectomy was associated with less NRM (HR 0.64, 95% CI 0.44-0.93, P = .018) but increased risk of relapse (HR 1.43, 95% CI 1.01-2.02, P = .042), with no significant impact on OS (HR 0.86, 95% CI 0.67-1.12, P = .274). However, in subset analysis comparing the impact of splenectomy vs specific spleen sizes, for patients with progressive disease, an improved survival was seen in splenectomised subjects compared to those patients with a palpable spleen length ≥ 15 cm (HR 0.44, 95% CI 0.28-0.69, P < .001), caused by a significant reduction in NRM (HR 0.26, 95% CI 0.14-0.49, P < .001), without significantly increased relapse risk (HR 1.47, 95% CI 0.87-2.49, P = .147). Overall, despite the possible biases typical of retrospective cohorts, this study highlights the potential detrimental effect of massive splenomegaly in transplant outcome and supports the role of splenectomy for myelofibrosis patients with progressive disease and large splenomegaly.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Trasplante de Células Madre Hematopoyéticas , Mielofibrosis Primaria , Sistema de Registros , Bazo , Esplenectomía , Aloinjertos , Busulfano/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Melfalán/administración & dosificación , Persona de Mediana Edad , Tamaño de los Órganos , Mielofibrosis Primaria/mortalidad , Mielofibrosis Primaria/patología , Mielofibrosis Primaria/terapia , Estudios Retrospectivos , Bazo/patología , Bazo/cirugía , Tasa de Supervivencia , Vidarabina/administración & dosificación , Vidarabina/análogos & derivadosRESUMEN
Vascular calcification (VC) is a risk factor for cardiovascular events and mortality in chronic kidney disease (CKD). Several components influence the occurrence of VC, among which inflammation. A novel uremic toxin, lanthionine, was shown to increase intracellular calcium in endothelial cells and may have a role in VC. A group of CKD patients was selected and divided into patients with a glomerular filtration rate (GFR) of <45 mL/min/1.73 m2 and ≥45 mL/min/1.73 m2. Total Calcium Score (TCS), based on the Agatston score, was assessed as circulating lanthionine and a panel of different cytokines. A hemodialysis patient group was also considered. Lanthionine was elevated in CKD patients, and levels increased significantly in hemodialysis patients with respect to the two CKD groups; in addition, lanthionine increased along with the increase in TCS, starting from one up to three. Interleukin IL-6, IL-8, and Eotaxin were significantly increased in patients with GFR < 45 mL/min/1.73 m2 with respect to those with GFR ≥ 45 mL/min/1.73 m2. IL-1b, IL-7, IL-8, IL-12, Eotaxin, and VEGF increased in calcified patients with respect to the non-calcified. IL-8 and Eotaxin were elevated both in the low GFR group and in the calcified group. We propose that lanthionine, but also IL-8 and Eotaxin, in particular, are a key feature of VC of CKD, with possible marker significance.
Asunto(s)
Alanina/análogos & derivados , Citocinas/sangre , Insuficiencia Renal Crónica/metabolismo , Sulfuros/sangre , Calcificación Vascular/metabolismo , Adulto , Alanina/sangre , Biomarcadores/sangre , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/complicaciones , Calcificación Vascular/sangre , Calcificación Vascular/etiologíaRESUMEN
Glycosphingolipids (GSLs) are ubiquitous components of eukaryotic plasma membranes that consist of a ceramide backbone linked to a glycan moiety. Both the ceramide and the glycan parts of GSLs display structural variations that result in a remarkable repertoire of diverse compounds. This diversity of GSLs is exploited during embryogenesis, when different GSLs are produced at specific developmental stages and along several differentiation trajectories. Importantly, plasma membrane receptors interact with GSLs to modify their activities. Consequently, two otherwise identical cells can respond differently to the same stimulus owing to their different GSL composition. The metabolic reprograming of GSLs is in fact a necessary part of developmental programs, as its impairment results in developmental failure or tissue-specific defects. Moreover, single-cell variability is emerging as a fundamental player in development: GSL composition displays cell-to-cell variability in syngeneic cell populations owing to the regulatory gene expression circuits involved in microenvironment adaptation and in differentiation. Here, we discuss how GSLs are synthesized and classified and review the role of GSLs in the establishment and maintenance of cell identity. We further highlight the existence of the regulatory circuits that modify GSL pathways and speculate how GSL heterogeneity might contribute to developmental patterning.
Asunto(s)
Diferenciación Celular/fisiología , Membrana Celular/metabolismo , Glicoesfingolípidos/metabolismo , Receptores de Superficie Celular/metabolismo , Animales , Ceramidas/química , Desarrollo Embrionario/fisiología , HumanosRESUMEN
RATIONALE & OBJECTIVE: Data for the association of sex with chronic kidney disease (CKD) progression are conflicting, a relationship this study sought to examine. STUDY DESIGN: Pooled analysis of 4 Italian observational cohort studies. SETTING & PARTICIPANTS: 1,311 older men and 1,024 older women with estimated glomerular filtration rate (eGFR)<45mL/min/1.73m2 followed up in renal clinics. PREDICTOR: Sex. OUTCOMES: End-stage kidney disease (ESKD), defined as maintenance dialysis or kidney transplantation, as the primary outcome; all-cause mortality and eGFR decline as secondary outcomes. ANALYTICAL APPROACH: Cox proportional hazard analysis to estimate the relative risk for ESKD and mortality and linear mixed models to estimate the rate of eGFR decline. RESULTS: Age, systolic blood pressure, and use of renin-angiotensin system inhibitors were similar in men and women. Baseline eGFRs were 27.6±10.2 in men and 26.0±10.6mL/min/1.73m2 in women (P<0.001), while median proteinuria was lower in women (protein excretion, 0.45 [IQR, 0.14-1.10] g/d) compared with men (0.69 [IQR 0.19-1.60] g/d; P<0.001). During a median follow-up of 4.2 years, 757 developed ESKD (59.4% men) and 471 died (58.4% men). The adjusted risks for ESKD and mortality were higher in men (HRs of 1.50 [95% CI, 1.28-1.77] and 1.30 [95% CI, 1.06-1.60], respectively). This finding was consistent across CKD stages. We observed a significant interaction between sex and proteinuria, with the risk for ESKD in men being significantly greater than for women at a level of proteinuria of â¼0.5g/d or greater. The slope of decline in eGFR was steeper in men (-2.09; 95% CI, -2.21 to-1.97mL/min/1.73m2 per year) than in women (-1.79; 95% CI, -1.92 to-1.66mL/min/1.73m2 per year; P<0.001). Although sex differences in eGFR decline were not different across CKD stages (P=0.3), the difference in slopes between men and women was progressively larger with proteinuria >0.5g/d (P = 0.04). LIMITATIONS: Residual confounding; only whites were included. CONCLUSIONS: Excess renal risk in men may, at least in part, be related to higher levels of proteinuria in men compared with women.
Asunto(s)
Fallo Renal Crónico/epidemiología , Proteinuria/metabolismo , Insuficiencia Renal Crónica/metabolismo , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Tasa de Filtración Glomerular , Humanos , Italia/epidemiología , Fallo Renal Crónico/terapia , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Mortalidad , Modelos de Riesgos Proporcionales , Proteinuria/epidemiología , Diálisis Renal , Factores SexualesRESUMEN
BACKGROUND: In non-dialysis chronic kidney disease (CKD), absolute proteinuria (Uprot) depends on the extent of kidney damage and residual glomerular filtration rate (GFR). We therefore evaluated, as compared with Uprot, the strength of association of proteinuria indexed to estimated GFR (eGFR) with end-stage renal disease (ESRD) risk. METHODS: In a multi-cohort prospective study in 3957 CKD patients of Stages G3-G5 referred to nephrology clinics, we tested two multivariable Cox models for ESRD risk, with either Uprot (g/24 h) or filtration-adjusted proteinuria (F-Uprot) calculated as Uprot/eGFR ×100. RESULTS: Mean ± SD age was 67 ± 14 years, males 60%, diabetics 29%, cardiovascular disease (CVD) 34%, eGFR 32 ± 13 mL/min/1.73 m2, median (interquartile range) Uprot 0.41 (0.12-1.29) g/24 h and F-Uprot 1.41 (0.36-4.93) g/24 h per 100 mL/min/1.73 m2 eGFR. Over a median follow-up of 44 months, 862 patients reached ESRD. At competing risk analysis, ESRD risk progressively increased when F-Uprot was 1.0-4.9 and ≥5.0 versus <1.0 g/24 h per 100 mL/min/1.73 m2 eGFR in Stages G3a-G4 (P < 0.001) and Stage G5 (P = 0.002). Multivariable Cox analysis showed that Uprot predicts ESRD in Stages G3a-G4 while in G5 the effect was not significant; conversely, F-Uprot significantly predicted ESRD at all stages. The F-Uprot model allowed a significantly better prediction versus the Uprot model according to Akaike information criterion. Net reclassification improvement was 12.2% (95% confidence interval 4.2-21.1), with higher reclassification in elderly, diabetes and CVD, as well as in diabetic nephropathy and glomerulonephritis, and in CKD Stages G4 and G5. CONCLUSIONS: In patients referred to nephrology clinics, F-Uprot predicts ESRD at all stages of overt CKD and improves, as compared with Uprot, reclassification of patients for renal risk, especially in more advanced and complicated disease.
Asunto(s)
Enfermedades Cardiovasculares/complicaciones , Nefropatías Diabéticas/complicaciones , Glomerulonefritis/complicaciones , Fallo Renal Crónico/clasificación , Proteinuria/complicaciones , Insuficiencia Renal Crónica/complicaciones , Anciano , Progresión de la Enfermedad , Femenino , Tasa de Filtración Glomerular , Humanos , Fallo Renal Crónico/etiología , Fallo Renal Crónico/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Factores de TiempoRESUMEN
INTRODUCTION: World Kidney Day (WKD) was promoted by the Italian Kidney Foundation and the Italian Society of Nephrology for raising awareness, detection, prevention, and treatment of kidney diseases. The Italian WKD focused on the "School Project" by screening students attending the fifth year of high school. The main goal of the "School Project" was to assess in healthy adolescents the presence of hypertension (HTN) and proteinuria; as well as to evaluate potential interrelations between overweight, obesity (both measured with different anthropometric methods), blood pressure (BP) levels, and proteinuria. The ancillary goal was to have an estimate of awareness on some nephrology topics. METHODS: The study population consisted of 17- to 19-year-old students. HTN was defined as systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mm Hg. Isolated systolic hypertension (ISH) was defined as SBP ≥140 mm Hg and DBP <90 mm Hg; isolated diastolic hypertension as SBP <140 mm Hg and DBP ≥90 mm Hg; systolic and diastolic hypertension as SBP ≥140 mm Hg and DBP ≥90 mm Hg; pre-hypertension as SBP >120 mm Hg but <140 mm Hg or DBP >80 mm Hg but <90 mm Hg; and optimal BP as SBP ≤120 mm Hg and DBP ≤80 mm Hg. Urine tests were performed with a dipstick; the subjects were regarded as proteinuric when the urine dipstick was positive (proteinuria ≥30 mg/dL). Body weight, height, and waist circumference (WC) were measured; body mass index (BMI), waist-to-height ratio (WHtR), and conicity index (Ci) were calculated. According to the BMI, the following classifications were adopted: underweight (<18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), class-I obesity (30-34.9 kg/m2), class-II obesity (35-39.9 kg/m2), class-III obesity (≥40 kg/m2). RESULTS: Data from 12,125 students (45.6% males) were evaluated. HTN was found in 1,349 participants (11.1%; 61.1% male), and ISH was present in 7.4%. Overweight (24.1%) and class-I (6%), -II (3.6%), and -III (1%) obesity were present in hypertensive participants. Compared to participants with normal BP, hypertensive participants had a higher BMI (p < 0.001), WC (p < 0.001), and WHtR (p < 0.001); whereas the Ci was not different (p = 0.527). Multivariate linear regression analysis showed that both WC and BMI were predictors of abnormal SBP and DBP (p < 0.001) both in males and females. Proteinuria was present in 14.8, 13.8, 14.7, and 14.7% of all normal weight, overweight, obese, and all subjects, respectively. In addition, no association was found between body weight, proteinuria, and BP. CONCLUSION: This study shows that overweight and obesity were significantly associated to HTN in Italian adolescents. BMI and WC were predictors of SBP and DBP. The occurrence of proteinuria was quite similar to that of HTN, but it was not associated with anthropometric indicators or HTN.
Asunto(s)
Peso Corporal/fisiología , Hipertensión/complicaciones , Riñón/patología , Proteinuria/complicaciones , Adolescente , Adulto , Femenino , Humanos , Hipertensión/orina , Italia , Masculino , Factores de Riesgo , Adulto JovenRESUMEN
Kidney transplant recipients (KTRs) are susceptible to low levels of vitamin D, which may be responsible for mineral and bone metabolism disorders and play some role in the occurrence of cardiovascular, metabolic, immunologic, neoplastic, and infectious complications after kidney transplant. Kidney Disease Improving Global Outcomes (KDIGO) guidelines of the year 2017 recommended vitamin D supplementation in the first 12 months after transplant using the same treatment strategies for the general population. However, no recommendations are provided after the first 12 months due to a lack of sufficient data. This review analyses some studies that assessed the vitamin D status of KTRs and the effects of nutritional and active vitamin D supplementation on bone mineral density, cardiovascular disease, proteinuria, and graft function in KTRs.
Asunto(s)
Trasplante de Riñón , Vitamina D/uso terapéutico , Vitaminas/uso terapéutico , Densidad Ósea , Enfermedades Óseas Metabólicas/prevención & control , Enfermedades Cardiovasculares/prevención & control , Suplementos Dietéticos , Supervivencia de Injerto/efectos de los fármacos , Humanos , Proteinuria/prevención & control , Vitamina D/administración & dosificación , Vitaminas/administración & dosificaciónRESUMEN
Intradermal therapy, known as mesotherapy, is a technique used to inject a drug into the surface layer of the skin. In particular, it involves the use of a short needle to deposit the drug in the dermis. The intradermal microdeposit modulates the drug's kinetics, slowing absorption and prolonging the local mechanism of action. It is successfully applied in the treatment of some forms of localized pain syndromes and other local clinical conditions. It could be suggested when a systemic drug-sparing effect is useful, when other therapies have failed (or cannot be used), and when it can synergize with other pharmacological or nonpharmacological therapies. Despite the lack of randomized clinical trials in some fields of application, a general consensus is also reached in nonpharmacological mechanism of action, the technique execution modalities, the scientific rationale to apply it in some indications, and the usefulness of the informed consent. The Italian Mesotherapy Society proposes this position paper to apply intradermal therapy based on scientific evidence and no longer on personal bias.