RESUMEN
Multiple omics analyzes of Vaccinia virus (VACV) infection have defined molecular characteristics of poxvirus biology. However, little is known about the monkeypox (mpox) virus (MPXV) in humans, which has a different disease manifestation despite its high sequence similarity to VACV. Here, we perform an in-depth multi-omics analysis of the transcriptome, proteome, and phosphoproteome signatures of MPXV-infected primary human fibroblasts to gain insights into the virus-host interplay. In addition to expected perturbations of immune-related pathways, we uncover regulation of the HIPPO and TGF-ß pathways. We identify dynamic phosphorylation of both host and viral proteins, which suggests that MAPKs are key regulators of differential phosphorylation in MPXV-infected cells. Among the viral proteins, we find dynamic phosphorylation of H5 that influenced the binding of H5 to dsDNA. Our extensive dataset highlights signaling events and hotspots perturbed by MPXV, extending the current knowledge on poxviruses. We use integrated pathway analysis and drug-target prediction approaches to identify potential drug targets that affect virus growth. Functionally, we exemplify the utility of this approach by identifying inhibitors of MTOR, CHUK/IKBKB, and splicing factor kinases with potent antiviral efficacy against MPXV and VACV.
Asunto(s)
Fibroblastos , Monkeypox virus , Mpox , Proteínas Virales , Humanos , Monkeypox virus/genética , Fosforilación , Mpox/virología , Mpox/metabolismo , Fibroblastos/virología , Fibroblastos/metabolismo , Proteínas Virales/metabolismo , Proteínas Virales/genética , Proteoma/metabolismo , Interacciones Huésped-Patógeno , Transducción de Señal , Proteómica/métodos , Transcriptoma , Antivirales/farmacología , MultiómicaRESUMEN
Several studies have associated platelets (PLTs) to NSCLC prognosis. To understand the role of PLTs in immunotherapy-treated patients, we used blood samples of NSCLC patients at different TNM stage. We found that PLTs count and the expression of PD-L1 (pPD-L1) were significantly higher in NSCLC patients at Stage IV than Stage I-III and healthy subjects. The presence of high pPD-L1 was associated to upregulated genes for the extracellular matrix organization and tumor immunosuppression. When patients' survival was correlated to the levels of pPD-L1, longer survival rate was observed, but not when progression disease occurred. The in vitro stimulation of pPD-L1 with Atezolizumab induced CXCL4 release, accompanied by higher levels of TGFß at the time of drug resistance when the levels of CD16, CD32 and CD64 significantly increased. Leiden-clustering method defined the phenotype of PLTs which showed that the ezrin-radixin-moesin (ERM) family proteins, underlying the PD-L1 signalosome, were involved in high pPD-L1 and higher survival rate. These data imply that Stage IV NSCLC patients characterized by high pPD-L1 are associated with longer progression-free survival rate because the blockade of pPD-L1 by Atezolizumab avoids the exacerbation of a T cell-mediated immune-suppressive environment. pPD-L1 could be an easy-to-use clinical approach to predict ICI responsiveness.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patología , Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéuticoRESUMEN
Sex is a biological variable that can reflect clinical outcomes in terms of quality of life, therapy effectiveness, responsiveness and/or toxicity. Sphingosine-1-phosphate (S1P) is a lipidic mediator whose activity can be influenced by sex. To evaluate whether the S1P axis underlies sex 'instructions' in the lung during physiological and oncological lung conditions, sphingosine and S1P were quantified in the blood of healthy (H) volunteers, lung adenocarcinoma (ADK) and squamous cell carcinoma (SCC) patients of both sexes. S1P receptors and their metabolic enzymes were evaluated in the tissues. Circulating levels of S1P were similar among H female and male subjects and female SCC patients. Instead, male and female ADK patients had lower circulating S1P levels. S1P receptor 3 (S1PR3) was physiologically expressed in the lung, but it was overexpressed in male SCC, and female and male ADK, but not in female SCC patients, who showed a significantly reduced ceramide synthase 1 (CERS1) mRNA and an overexpression of the ceramidase (ASAH1) precursor in lung tumor tissues, compared to male SCC and both male and female ADK patients. These findings highlighted sex differences in S1P rheostat in pathological conditions, but not in physiological conditions, identifying S1P as a prognostic mediator depending on lung cancer histotype.
Asunto(s)
Neoplasias Pulmonares , Esfingosina , Humanos , Masculino , Femenino , Esfingosina/metabolismo , Ceramidasas/metabolismo , Caracteres Sexuales , Calidad de Vida , Lisofosfolípidos/metabolismo , Pulmón/metabolismo , Neoplasias Pulmonares/metabolismoRESUMEN
Polycyclic aromatic hydrocarbons (PAHs) are widespread across the globe and can be highly toxic for the marine environment. This research investigated the short-term (48 h of exposure) effects of PAHs mixtures on the nauplii and adult of crustacean Artemia franciscana considering the impact in term of toxicity and changes in gene expression. Results showed that all combinations caused additive or synergic effects with the exception of naphthalene + phenanthrene (NAP + PHE; Combination Index (CI) = 22.3), while naphthalene + benzo(k)fluoranthene (NAP + BkF; CI = 7.8) mixture evidenced an antagonistic effect. Real-time qPCR showed that all mixtures impacted the expression level of the five known genes involved in Artemia stress response. The effects of PAHs at environmental concentrations on both adult and nauplii suggested the need for further investigations about the impact of such contaminants on the marine biota considering that crustaceans can accumulate PAHs at concentrations comparable to those assessed in the present study.
Asunto(s)
Fenantrenos , Hidrocarburos Policíclicos Aromáticos , Animales , Artemia , Hidrocarburos Policíclicos Aromáticos/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Naftalenos , Fenantrenos/toxicidadRESUMEN
The stimulator of interferon genes (STING) is a master regulator of innate immunity, involved in several inflammatory diseases. Our previous data showed that sphingosine-1-phosphate (S1P) is released during inflammatory conditions in the lung. The aim of this study was to understand the interplay between S1P and STING during both physiological and pathological conditions. The mRNA levels of ceramidase (ASAH1), S1P precursor enzyme, and STING were inversely correlated in healthy lung tissues, but positively correlated in tumor tissues. The activation of STING induced higher expression of ASAH1 and was accompanied by IFN-ß and IL-6 release. ASAH1 and sphingosine kinases (SPHK I/II) blockade significantly reduced IL-6, but not IFNß, after STING activation. In support of this, taking advantage of a mouse model, we found that inflamed lungs had higher levels of inactive ASAH1 when STING was inhibited. This confirmed the human data, where higher levels of STING promoted the activation of ASAH1. Lung cancer patients positive to STING and ASAH1 mRNA levels had a dismal prognosis in that the overall survival was reduced compared to STING/ASAH1 negative patients. These data highlight that during physiological conditions, STING and the S1P axis do not interfere, whereas in lung cancer patients their interplay is associated to poor prognosis.
Asunto(s)
Neoplasias Pulmonares , Esfingosina , Animales , Humanos , Ratones , Inflamación , Interleucina-6/genética , Pulmón/metabolismo , Neoplasias Pulmonares/genética , Lisofosfolípidos/metabolismo , Esfingosina/metabolismoRESUMEN
Sphingosine-1-phosphate (S1P) is involved in inflammatory signaling/s associated with the development of respiratory disorders, including cancer. However, the underlying mechanism/s are still elusive. The aim of this study was to investigate the role of S1P on circulating blood cells obtained from healthy volunteers and non-small cell lung cancer (NSCLC) patients. To pursue our goal, peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with S1P. We found that the administration of S1P did not induce healthy PBMCs to release pro-inflammatory cytokines. In sharp contrast, S1P significantly increased the levels of TNF-α and IL-6 from lung cancer-derived PBMCs. This effect was S1P receptor 3 (S1PR3)-dependent. The pharmacological blockade of ceramidase and sphingosine kinases (SPHKs), key enzymes for S1P synthesis, completely reduced the release of both TNF-α and IL-6 after S1P addition on lung cancer-derived PBMCs. Interestingly, S1P-induced IL-6, but not TNF-α, release from lung cancer-derived PBMCs was mTOR- and K-Ras-dependent, while NF-κB was not involved. These data identify S1P as a bioactive lipid mediator in a chronic inflammation-driven diseases such as NSCLC. In particular, the higher presence of S1P could orchestrate the cytokine milieu in NSCLC, highlighting S1P as a pro-tumor driver.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Neumonía , Carcinoma de Pulmón de Células no Pequeñas/patología , Citocinas , Humanos , Inflamación/patología , Interleucina-6 , Leucocitos Mononucleares , Neoplasias Pulmonares/patología , Lisofosfolípidos , Neumonía/patología , Esfingosina/análogos & derivados , Esfingosina/farmacología , Factor de Necrosis Tumoral alfaRESUMEN
BACKGROUND/AIMS: The pleiotropic lipid mediator sphingosine-1-phosphate (S1P) exerts a multitude of effects on respiratory cell physiology and pathology through five S1P receptors (S1PR1-5). Epidemiological studies proved high levels of circulating S1P in non-small cell lung cancer (NSCLC) patients. Studies in literature suggest that high levels of S1P support carcinogenesis but the exact mechanism is still elusive. The aim of this study was to understand the mechanism/s underlying S1P-mediated lung tumor cell proliferation. METHODS: We used human samples of NSCLC, a mouse model of first-hand smoking and of Benzo(a)pyrene (BaP)-induced tumor-bearing mice and A549 lung adenocarcinoma cells. RESULTS: We found that the expression of S1PR3 was also into the nucleus of lung cells in vitro, data that were confirmed in lung tissues of NSCLC patients, smoking and tumor bearing BaP-exposed mice. The intranuclear, but not the membrane, localization of S1PR3 was associated to S1P-mediated proliferation of lung adenocarcinoma cells. Indeed, the inhibition of the membrane S1PR3 did not alter tumor cell proliferation after Toll Like Receptor (TLR) 9 activation. Instead, according to the nuclear localization of sphingosine kinase (SPHK) II, the inhibition of the kinase completely blocked the endogenous S1P-induced tumor cell proliferation. CONCLUSION: These results prove that the nuclear S1PR3/SPHK II axis is involved in lung tumor cell proliferation, highlighting a novel molecular mechanism which could provide differential therapeutic approaches especially in non-responsive lung cancer patients.
Asunto(s)
Adenocarcinoma del Pulmón/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Transducción de Señal , Receptores de Esfingosina-1-Fosfato/metabolismo , Células A549 , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/patología , Animales , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Proteínas de Neoplasias/genética , Receptores de Esfingosina-1-Fosfato/genéticaRESUMEN
Amyloid plaques are a hallmark of Alzheimer's disease (AD) that develop in its earliest stages. Thus, non-invasive detection of these plaques would be invaluable for diagnosis and the development and monitoring of treatments, but this remains a challenge due to their small size. Here, we investigated the utility of manganese-enhanced MRI (MEMRI) for visualizing plaques in transgenic rodent models of AD across two species: 5xFAD mice and TgF344-AD rats. Animals were given subcutaneous injections of MnCl2 and imaged in vivo using a 9.4 T Bruker scanner. MnCl2 improved signal-to-noise ratio but was not necessary to detect plaques in high-resolution images. Plaques were visible in all transgenic animals and no wild-types, and quantitative susceptibility mapping showed that they were more paramagnetic than the surrounding tissue. This, combined with beta-amyloid and iron staining, indicate that plaque MR visibility in both animal models was driven by plaque size and iron load. Longitudinal relaxation rate mapping revealed increased manganese uptake in brain regions of high plaque burden in transgenic animals compared to their wild-type littermates. This was limited to the rhinencephalon in the TgF344-AD rats, while it was most significantly increased in the cortex of the 5xFAD mice. Alizarin Red staining suggests that manganese bound to plaques in 5xFAD mice but not in TgF344-AD rats. Multi-parametric MEMRI is a simple, viable method for detecting amyloid plaques in rodent models of AD. Manganese-induced signal enhancement can enable higher-resolution imaging, which is key to visualizing these small amyloid deposits. We also present the first in vivo evidence of manganese as a potential targeted contrast agent for imaging plaques in the 5xFAD model of AD.
Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Corteza Cerebral/diagnóstico por imagen , Cloruros/administración & dosificación , Compuestos de Manganeso/administración & dosificación , Imágenes de Resonancia Magnética Multiparamétrica/métodos , Placa Amiloide/diagnóstico , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/análisis , Animales , Corteza Cerebral/química , Corteza Cerebral/patología , Modelos Animales de Enfermedad , Femenino , Humanos , Inyecciones Subcutáneas , Hierro/análisis , Masculino , Ratones , Ratones Transgénicos , Placa Amiloide/patología , Ratas , Ratas TransgénicasRESUMEN
Mutations in nuclear-encoded protein subunits of the mitochondrial ribosome are an increasingly recognised cause of oxidative phosphorylation system (OXPHOS) disorders. Among them, mutations in the MRPL44 gene, encoding a structural protein of the large subunit of the mitochondrial ribosome, have been identified in four patients with OXPHOS defects and early-onset hypertrophic cardiomyopathy with or without additional clinical features. A 23-year-old individual with cardiac and skeletal myopathy, neurological involvement, and combined deficiency of OXPHOS complexes in skeletal muscle was clinically and genetically investigated. Analysis of whole-exome sequencing data revealed a homozygous mutation in MRPL44 (c.467 T > G), which was not present in the biological father, and a region of homozygosity involving most of chromosome 2, raising the possibility of uniparental disomy. Short-tandem repeat and genome-wide SNP microarray analyses of the family trio confirmed complete maternal uniparental isodisomy of chromosome 2. Mitochondrial ribosome assembly and mitochondrial translation were assessed in patient derived-fibroblasts. These studies confirmed that c.467 T > G affects the stability or assembly of the large subunit of the mitochondrial ribosome, leading to impaired mitochondrial protein synthesis and decreased levels of multiple OXPHOS components. This study provides evidence of complete maternal uniparental isodisomy of chromosome 2 in a patient with MRPL44-related disease, and confirms that MRLP44 mutations cause a mitochondrial translation defect that may present as a multisystem disorder with neurological involvement.
Asunto(s)
Cromosomas Humanos Par 2/genética , Enfermedades Mitocondriales/genética , Proteínas Mitocondriales/genética , Proteínas Ribosómicas/genética , Disomía Uniparental/genética , Adolescente , Secuencia de Bases , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Preescolar , Femenino , Fibroblastos/patología , Homocigoto , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética , Enfermedades Mitocondriales/patología , Músculo Esquelético/metabolismo , Mutación/genética , Fosforilación Oxidativa , Biosíntesis de Proteínas , Adulto JovenRESUMEN
BACKGROUND: Therapy/prognosis of Non-Small Cell Lung Cancer (NSCLC) patients are strongly related to gene alteration/s or protein expression. However, more than 50% of NSCLC patients are negative to key drugable biomarkers. METHODS: We used human samples of NSCLC and mouse models of lung adenocarcinoma. RESULTS: We showed that caspase-4 was highly present in the tumor mass compared to non-cancerous human tissues. Interestingly, the orthologue murine caspase-11 promoted lung carcinogenesis in mice. Carcinogen-exposed caspase-11 knockout mice had lower tumor lesions than wild type mice, due to the relevance of caspase-11 in the structural lung cell as demonstrated by bone marrow transplantation and adoptive transfer experiments. Similarly to what observed in mice, caspase-4 was correlated to the stage of lung cancer in humans in that it induced cell proliferation in a K-Ras, c-MyC and IL-1α dependent manner. Caspase-4 positive adenocarcinoma (79.3%) and squamous carcinoma (88.2%) patients had lower median survival than patients who had lower levels of caspase-4. Moreover, PD-L1 expression and gene mutation (i.e. EGFR) were not correlated to caspase-4 expression. Instead, NSCLC patients who had K-Ras or c-MyC gene alteration were positively correlated to higher levels of caspase-4 and lower survival rate. CONCLUSIONS: We identified a subgroup of NSCLC patients as caspase-4 positive among which double and triple positive caspase-4, K-Ras and/or c-MyC patients which prognosis was poor. Because K-Ras and c-MyC are still undrugable, the identification of caspase-4 as a novel oncoprotein could introduce novelty in the clinical yet unmet needs for NSCLC patients.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Caspasas Iniciadoras/metabolismo , Neoplasias Pulmonares/genética , Animales , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Modelos Animales de Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Ratones , Persona de Mediana Edad , Pronóstico , Análisis de Supervivencia , TransfecciónRESUMEN
Lung cancer is by far the leading cause of cancer death. Metabolomic studies have highlighted that both tumor progression and limited curative treatment options are partly due to dysregulated glucose metabolism and its associated signaling pathways. In our previous studies, we identified caspase-4 as a novel diagnostic tool for non-small cell lung cancer (NSCLC). Here, we analyzed the metabolomic profile of both plasma and tumor tissues of NSCLC patients stratified as caspase-4 positive or negative. We found that circulating caspase-4 was correlated to LDH. However, this effect was not observed in caspase-4 positive tumor tissues, where instead, fatty acid biosynthesis was favoured in that the malonic acid and the palmitic acid were higher than in non-cancerous and caspase-4 negative tissues. The glycolytic pathway in caspase-4 positive NSCLC tissues was bypassed by the malonic acid-dependent lipogenesis. On the other hand, the dysregulated glucose metabolism was regulated by a higher presence of succinate dehydrogenase (SDHA) and by the gluconeogenic valine which favoured Krebs' cycle. In conclusion, we found that the recently identified caspase-4 positive subpopulation of NSCLC patients is characterized by a lipidomic profile accompanied by alternative pathways to guarantee glucose metabolism in favour of tumor cell proliferation.
RESUMEN
The unilateral 6-hydroxydopamine (6-OHDA) model of Parkinson's disease (PD) is one of the most commonly used in rodents. The anatomical, metabolic, and behavioral changes that occur after severe and stable 6-OHDA lesions have been extensively studied. Here, we investigated whether early motor behavioral deficits can be observed in the first week after the injection of 6-OHDA into the right substantia nigra pars compacta (SNc), and if they were indicative of the severity of the dopaminergic (DAergic) lesion in the SNc and the striatum at different time-points (day 1, 3, 5, 7, 14, 21). With this aim, we used our newly modified tail suspension swing test (TSST), the standard rotation test (RT), and immunohistochemical staining for tyrosine hydroxylase (TH). The TSST, but not the standard RT, revealed a spontaneous motor bias for the 6-OHDA-lesioned rats from the day 1 post-surgery. Both tests detected the motor asymmetry induced by (single and repeated) apomorphine (APO) challenges that correlated, in the first week, with the DAergic neuronal degeneration. The described TSST is fast and easy to perform, and in the drug-free condition is useful for the functional assessment of early motor asymmetry appearing after the 6-OHDA-lesion in the SNc, without the confounding effect of APO challenges.
Asunto(s)
Conducta Animal , Suspensión Trasera , Actividad Motora , Enfermedades Neurodegenerativas/etiología , Enfermedades Neurodegenerativas/fisiopatología , Oxidopamina/efectos adversos , Rotación , Animales , Conducta Animal/efectos de los fármacos , Biomarcadores , Estudios de Casos y Controles , Cuerpo Estriado/metabolismo , Cuerpo Estriado/patología , Modelos Animales de Enfermedad , Inmunohistoquímica , Enfermedades Neurodegenerativas/metabolismo , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/fisiopatología , Ratas , Sustancia Negra/metabolismo , Sustancia Negra/patologíaRESUMEN
Autosomal dominant progressive external ophthalmoplegia (adPEO) is a late-onset, Mendelian mitochondrial disorder characterised by paresis of the extraocular muscles, ptosis, and skeletal-muscle restricted multiple mitochondrial DNA (mtDNA) deletions. Although dominantly inherited, pathogenic variants in POLG, TWNK and RRM2B are among the most common genetic defects of adPEO, identification of novel candidate genes and the underlying pathomechanisms remains challenging. We report the clinical, genetic and molecular investigations of a patient who presented in the seventh decade of life with PEO. Oxidative histochemistry revealed cytochrome c oxidase-deficient fibres and occasional ragged red fibres showing subsarcolemmal mitochondrial accumulation in skeletal muscle, while molecular studies identified the presence of multiple mtDNA deletions. Negative candidate screening of known nuclear genes associated with PEO prompted diagnostic exome sequencing, leading to the prioritisation of a novel heterozygous c.547G>C variant in GMPR (NM_006877.3) encoding guanosine monophosphate reductase, a cytosolic enzyme required for maintaining the cellular balance of adenine and guanine nucleotides. We show that the novel c.547G>C variant causes aberrant splicing, decreased GMPR protein levels in patient skeletal muscle, proliferating and quiescent cells, and is associated with subtle changes in nucleotide homeostasis protein levels and evidence of disturbed mtDNA maintenance in skeletal muscle. Despite confirmation of GMPR deficiency, demonstrating marked defects of mtDNA replication or nucleotide homeostasis in patient cells proved challenging. Our study proposes that GMPR is the 19th locus for PEO and highlights the complexities of uncovering disease mechanisms in late-onset PEO phenotypes.
Asunto(s)
ADN Mitocondrial/genética , GMP-Reductasa/genética , Enfermedades de Inicio Tardío/genética , Músculo Esquelético/enzimología , Oftalmoplejía/genética , Adenina/metabolismo , Anciano , Células Cultivadas , Deficiencia de Citocromo-c Oxidasa/metabolismo , Replicación del ADN , ADN Mitocondrial/metabolismo , Femenino , Fibroblastos/enzimología , GMP-Reductasa/deficiencia , GMP-Reductasa/metabolismo , Guanina/metabolismo , Células HEK293 , Células HeLa , Heterocigoto , Humanos , Enfermedades de Inicio Tardío/metabolismo , Enfermedades de Inicio Tardío/patología , Músculo Esquelético/patología , Oftalmoplejía/enzimología , Oftalmoplejía/fisiopatología , Fosforilación Oxidativa , Empalme del ARN , Eliminación de Secuencia , Secuenciación del ExomaRESUMEN
Concentrated aqueous solutions of surfactants, often referred to as pastes, experience complex phase and rheology changes upon dissolution in water, which is a typical step in the production of liquid detergents. During the dilution process, depending on water content, surfactant molecules can arrange in different morphologies, such as lamellar or cubic and hexagonal structures. These phases are characterized by different physico-chemical properties, such as viscosity or diffusivity, which lead to non-simple transport mechanisms during the dissolution process. In this work, we investigate the dissolution of concentrated Sodium Lauryl Ether Sulfate (SLES) pastes in water under quiescent conditions by coupling different experimental techniques. A thorough rheological characterization of the system showed non-monotonic changes of several orders of magnitude in its viscosity and viscoelastic moduli as a function of water content. Time-lapse microscopy allowed us to image the dynamic evolution of the phase changes as water penetrated in a disk-shaped sample (with the same geometry used in rheological tests). Numerical simulation, based on a simple diffusion-based multi-parameter model is shown to describe satisfactorily SLES dissolution data.
RESUMEN
Mitochondria contain their own genome (mtDNA), encoding 13 proteins of the enzyme complexes of the oxidative phosphorylation. Synthesis of these 13 mitochondrial proteins requires a specific translation machinery, the mitoribosomes whose RNA components are encoded by the mtDNA, whereas more than 80 proteins are encoded by nuclear genes. It has been well established that mitochondrial topoisomerase I (TOP1MT) is important for mtDNA integrity and mitochondrial transcription as it prevents excessive mtDNA negative supercoiling and releases topological stress during mtDNA replication and transcription. We recently showed that TOP1MT also supports mitochondrial protein synthesis, and thus is critical for promoting tumor growth. Impaired mitochondrial protein synthesis leads to activation of the mitonuclear stress response through the transcription factor ATF4, and induces cytoprotective genes in order to prevent mitochondrial and cellular dysfunction. In this perspective, we highlight the novel role of TOP1MT in mitochondrial protein synthesis and as potential target for chemotherapy.
Asunto(s)
ADN-Topoisomerasas de Tipo I/metabolismo , ADN Mitocondrial/metabolismo , Mitocondrias/genética , Proteínas Mitocondriales/biosíntesis , Biosíntesis de Proteínas , Factor de Transcripción Activador 4/metabolismo , Animales , Carcinogénesis/genética , Carcinogénesis/metabolismo , Proliferación Celular/genética , Replicación del ADN/genética , ADN-Topoisomerasas de Tipo I/genética , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , Mitocondrias/metabolismo , Proteínas Mitocondriales/genética , Biosíntesis de Proteínas/efectos de los fármacos , Transcripción GenéticaRESUMEN
Mitochondrial disorders are clinically and genetically heterogeneous and are associated with a variety of disease mechanisms. Defects of mitochondrial protein synthesis account for the largest subgroup of disorders manifesting with impaired respiratory chain capacity; yet, only a few have been linked to dysfunction in the protein components of the mitochondrial ribosomes. Here, we report a subject presenting with dyskinetic cerebral palsy and partial agenesis of the corpus callosum, while histochemical and biochemical analyses of skeletal muscle revealed signs of mitochondrial myopathy. Using exome sequencing, we identified a homozygous variant c.215C>T in MRPS25, which encodes for a structural component of the 28S small subunit of the mitochondrial ribosome (mS25). The variant segregated with the disease and substitutes a highly conserved proline residue with leucine (p.P72L) that, based on the high-resolution structure of the 28S ribosome, is predicted to compromise inter-protein contacts and destabilize the small subunit. Concordant with the in silico analysis, patient's fibroblasts showed decreased levels of MRPS25 and other components of the 28S subunit. Moreover, assembled 28S subunits were scarce in the fibroblasts with mutant mS25 leading to impaired mitochondrial translation and decreased levels of multiple respiratory chain subunits. Crucially, these abnormalities were rescued by transgenic expression of wild-type MRPS25 in the mutant fibroblasts. Collectively, our data demonstrate the pathogenicity of the p.P72L variant and identify MRPS25 mutations as a new cause of mitochondrial translation defect.
Asunto(s)
Mitocondrias/genética , Encefalomiopatías Mitocondriales/genética , Proteínas Mitocondriales/genética , Mutación , Biosíntesis de Proteínas , Proteínas Ribosómicas/genética , Adulto , Biomarcadores , Fibroblastos/metabolismo , Predisposición Genética a la Enfermedad , Homocigoto , Humanos , Imagen por Resonancia Magnética , Masculino , Mitocondrias/metabolismo , Encefalomiopatías Mitocondriales/diagnóstico , Encefalomiopatías Mitocondriales/metabolismo , Modelos Biológicos , Linaje , Fenotipo , Secuenciación del ExomaRESUMEN
Cardiogenic liver disease is a common yet poorly characterized complication of advanced heart failure (HF), and may impact clinical management in the setting of heart transplant evaluation. In this retrospective study, we describe clinical and histopathological features of liver injury in advanced HF, with a focus on the role of liver biopsy. Included were 45 HF patients, assessed for possible heart transplant, who underwent liver biopsy for suspected liver disease. Median duration of HF symptoms was 5 years. Most patients had stiff hepatomegaly and elevated bilirubin. Viral hepatitis (19 patients, 42.2%) was the most common cause of prior known liver disease. Sinusoidal dilatation was detected in the majority of patients (64.4%). Median necroinflammatory index was 3 and median fibrosis was 1, consistent with a small burden of histologically proven liver disease. Viral hepatitis was the only variable associated with a higher grade of necroinflammation and fibrosis. Nine of the 14 (64.3%) advanced fibrosis/cirrhosis patients had a viral hepatitis infection. Fibrosis was significantly associated with splenomegaly. The MELD score was not correlated with cardiac index. A coarse liver echo-pattern had a 29% positive and 63% negative predictive value for advanced fibrosis/cirrhosis. Severe liver disease is uncommon in patients with advanced HF in the absence of splenomegaly or primary causes of liver disease. Ultrasound data need to be carefully evaluated, as it may overstate the severity of liver disease. Liver biopsy may be needed to accurately stage liver disease before excluding patients from advanced treatment strategies.
Asunto(s)
Insuficiencia Cardíaca/complicaciones , Hígado/patología , Adulto , Biopsia/métodos , Femenino , Fibrosis/etiología , Fibrosis/fisiopatología , Insuficiencia Cardíaca/fisiopatología , Heparina de Bajo-Peso-Molecular/farmacocinética , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Retrospectivos , Estadísticas no Paramétricas , Ultrasonografía/métodosRESUMEN
The basal ganglia circuitry plays a crucial role in the sequential organization of behavior. Here we studied the behavioral structure of the animals after 21 days of 6-OHDA-induced lesion of the dopaminergic nigrostriatal system. Frequencies and durations of individual components of the behavioral repertoire were calculated; moreover, whether a temporal organization of the activity was present, it was investigated by using T-pattern analysis, a multivariate approach able to detect the real-time sequential organization of behavior. Six sham-depleted and six rats with unilateral 6-OHDA-lesion of the Substantia Nigra pars compacta were used. As to quantitative evaluations, the comparison between lesioned and unlesioned rats revealed significant differences only for the mean occurrences of Walking, Immobile Sniffing and Stretched Sniffing, reduced in lesioned subjects. All the remaining components of the behavior did not show significant changes. On the other hand, results from T-pattern analysis showed a reduction of the number of different T-patterns, of their mean length and of their occurrences in 6-OHDA-lesioned rats. Overall, these results suggest that the main deficit in 6-OHDA-lesioned subjects, rather than in the production of individual behavioral components, lies in deficiencies of their sequential organization.
Asunto(s)
Conducta Animal/efectos de los fármacos , Oxidopamina/farmacología , Enfermedad de Parkinson/tratamiento farmacológico , Porción Compacta de la Sustancia Negra/efectos de los fármacos , Animales , Dopamina/farmacología , Masculino , Ratas Sprague-Dawley , Sustancia Negra/efectos de los fármacos , Núcleo Subtalámico/efectos de los fármacosRESUMEN
[This corrects the article DOI: 10.18632/oncotarget.25049.].