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1.
Ann Ig ; 36(2): 194-214, 2024.
Article En | MEDLINE | ID: mdl-38240184

Introduction: The COVID-19 pandemic presented unprecedented challenges to European healthcare systems. The study aimed to review the available evidence on the impact of the pandemic on the timely diagnosis of cancer across European countries. The primary objective was to examine changes in diagnostic pathways and stage at diagnosis during the pandemic, compared to the pre-pandemic period, across European countries, taking healthcare system characteristics and COVID-19 policies into account. Methods: We conducted a review of the impact of the pandemic on cancer diagnosis in Europe, analyzing primary studies from 2018 to 2023 using both quantitative and qualitative methods through searches in PubMed and Scopus databases. Study quality was assessed using the Mixed Methods Appraisal Tool. The main explanatory factors analyzed were grouped into two categories: Covid-policies (government responses, using the Oxford COVID-19 Government Response Tracker and its stringency index as key metrics) and healthcare characteristics (healthcare system models, expenditure and resources, including hospital beds and the ratio of medical doctors). Study design: Scoping review. Results: Overall, 127 papers were screened, 80 retrieved for full-text evaluation and 50 articles were included in the review. The studies encompassed a total of 509,753 patients from 17 European countries. The pandemic period was characterised by worse process and outcome measures for all examined cancers, except for lung cancer, compared to the pre-pandemic period. Group-ing countries based on government actions and policy responses (stringency index) did not show any differences in timely cancer diagnosis. Countries with lower healthcare expenditure (per capita expenditure <2,000 euros) or lower investments in prevention reported more cancer diagnostic delays during the pandemic. Countries with >20% of General Practitioners over the total number of physicians and with more hospital beds per population experienced fewer diagnostic delays during the pandemic. Conclusions: Overall, the review suggests that diagnostic pathways and cancer stage at diagnosis during the COVID-19 pandemic varied across Europe, with countries' healthcare expenditure, investments in prevention, the proportion of General Practitioners and the number of hospital beds per population possibly playing a role. This analysis can inform healthcare policies aimed at addressing post-pandemic challenges and formulating resilience plans for future emergencies.


COVID-19 , Neoplasms , Humans , COVID-19/epidemiology , Pandemics/prevention & control , SARS-CoV-2 , Delivery of Health Care , Neoplasms/diagnosis , Neoplasms/epidemiology , COVID-19 Testing
2.
Acta Biomed ; 94(S3): e2023161, 2023 08 30.
Article En | MEDLINE | ID: mdl-37695178

BACKGROUND AND AIM: Early cancer diagnosis is a public health priority, but large proportions of patients are diagnosed with advanced disease or as an emergency, even in countries with universal healthcare coverage. The study aimed at examining factors contributing to diagnostic delays and inequalities in cancer care, discussing challenges and opportunities for improving the diagnosis of cancer. METHODS: We performed a critical review of the literature examining factors contributing to delays and inequalities in cancer diagnosis, published between 2019-2023, in Europe with a specific focus on Italy. RESULTS: Disparities in screening, cancer diagnosis and treatment have been reported in many European countries, with poorer outcomes for some population sub-groups. For example, some Northern regions in Italy have six-times higher screening participation versus Southern regions. In 2019 36% of the Italian population aged 50-74 reported colorectal cancer screening, higher than the EU average (33%), but lower than in countries like Denmark (>60%). In Italy, the EU country with the largest percentage of people aged 65+, incident cancers are expected to rise by 19.6% over two decades. Older age is also associated with multimorbidity, with physical and mental health morbidities possibly affecting cancer diagnostic pathways. For example, colon cancer patients with pre-existing mental health conditions were 28% less likely to have a prompt colonoscopy when presenting with red-flag symptoms, according to recent UK research. Covid-19 has exacerbated pre-existing inequalities, with reductions in scheduled surgery and oncological treatments, especially affecting women, older and less educated individuals. CONCLUSIONS: For ensuring appropriate care, it is crucial to better understand how different factors, including physical and mental health morbidities, impact cancer diagnosis. The "NextGenerationEU" program and the "National Recovery and Resilience Plan" (PNNR in Italy) following the Covid-19 pandemic offer opportunities for reducing inequalities, improving cancer care and chronic disease management for ageing populations.


COVID-19 , Colonic Neoplasms , Humans , Female , Pandemics , COVID-19/epidemiology , Europe/epidemiology , Italy/epidemiology
3.
Int J Mol Sci ; 24(4)2023 Feb 09.
Article En | MEDLINE | ID: mdl-36834939

Mutations in the receptor expression-enhancing protein 1 gene (REEP1) are associated with hereditary spastic paraplegia type 31 (SPG31), a neurological disorder characterized by length-dependent degeneration of upper motor neuron axons. Mitochondrial dysfunctions have been observed in patients harboring pathogenic variants in REEP1, suggesting a key role of bioenergetics in disease-related manifestations. Nevertheless, the regulation of mitochondrial function in SPG31 remains unclear. To elucidate the pathophysiology underlying REEP1 deficiency, we analyzed in vitro the impact of two different mutations on mitochondrial metabolism. Together with mitochondrial morphology abnormalities, loss-of-REEP1 expression highlighted a reduced ATP production with increased susceptibility to oxidative stress. Furthermore, to translate these findings from in vitro to preclinical models, we knocked down REEP1 in zebrafish. Zebrafish larvae showed a significant defect in motor axon outgrowth leading to motor impairment, mitochondrial dysfunction, and reactive oxygen species accumulation. Protective antioxidant agents such as resveratrol rescued free radical overproduction and ameliorated the SPG31 phenotype both in vitro and in vivo. Together, our findings offer new opportunities to counteract neurodegeneration in SPG31.


Membrane Transport Proteins , Oxidative Stress , Spastic Paraplegia, Hereditary , Animals , Axons/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Mutation , Oxidative Stress/genetics , Spastic Paraplegia, Hereditary/genetics , Zebrafish/metabolism , Zebrafish Proteins/metabolism
4.
Hum Mol Genet ; 32(2): 333-350, 2023 01 06.
Article En | MEDLINE | ID: mdl-35994048

Dominant mutations in ubiquitously expressed mitofusin 2 gene (MFN2) cause Charcot-Marie-Tooth type 2A (CMT2A; OMIM 609260), an inherited sensory-motor neuropathy that affects peripheral nerve axons. Mitofusin 2 protein has been found to take part in mitochondrial fusion, mitochondria-endoplasmic reticulum tethering, mitochondrial trafficking along axons, mitochondrial quality control and various types of cancer, in which MFN2 has been indicated as a tumor suppressor gene. Discordant data on the mitochondrial altered phenotypes in patient-derived fibroblasts harboring MFN2 mutations and in animal models have been reported. We addressed some of these issues by focusing on mitochondria behavior during autophagy and mitophagy in fibroblasts derived from a CMT2AMFN2 patient with an MFN2650G > T/C217F mutation in the GTPase domain. This study investigated mitochondrial dynamics, respiratory capacity and autophagy/mitophagy, to tackle the multifaceted MFN2 contribution to CMT2A pathogenesis. We found that MFN2 mutated fibroblasts showed impairment of mitochondrial morphology, bioenergetics capacity, and impairment of the early stages of autophagy, but not mitophagy. Unexpectedly, transcriptomic analysis of mutated fibroblasts highlighted marked differentially expressed pathways related to cell population proliferation and extracellular matrix organization. We consistently found the activation of mTORC2/AKT signaling and accelerated proliferation in the CMT2AMFN2 fibroblasts. In conclusion, our evidence indicates that MFN2 mutation can positively drive cell proliferation in CMT2AMFN2 fibroblasts.


Charcot-Marie-Tooth Disease , Mitochondrial Proteins , Animals , Cell Proliferation/genetics , Charcot-Marie-Tooth Disease/metabolism , Fibroblasts/metabolism , Mitochondria/metabolism , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Mutation , Humans
5.
Biomolecules ; 12(8)2022 07 24.
Article En | MEDLINE | ID: mdl-35892334

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an inherited neurodegenerative disease characterized by early-onset spasticity in the lower limbs, axonal-demyelinating sensorimotor peripheral neuropathy, and cerebellar ataxia. Our understanding of ARSACS (genetic basis, protein function, and disease mechanisms) remains partial. The integrative use of organelle-based quantitative proteomics and whole-genome analysis proposed in the present study allowed identifying the affected disease-specific pathways, upstream regulators, and biological functions related to ARSACS, which exemplify a rationale for the development of improved early diagnostic strategies and alternative treatment options in this rare condition that currently lacks a cure. Our integrated results strengthen the evidence for disease-specific defects related to bioenergetics and protein quality control systems and reinforce the role of dysregulated cytoskeletal organization in the pathogenesis of ARSACS.


Proteomics , Spinocerebellar Ataxias , Heat-Shock Proteins/genetics , Humans , Muscle Spasticity , Mutation , Organelles , Spinocerebellar Ataxias/congenital
6.
Cells ; 11(11)2022 06 04.
Article En | MEDLINE | ID: mdl-35681535

CLN5 disease (MIM: 256731) represents a rare late-infantile form of neuronal ceroid lipofuscinosis (NCL), caused by mutations in the CLN5 gene that encodes the CLN5 protein (CLN5p), whose physiological roles stay unanswered. No cure is currently available for CLN5 patients and the opportunities for therapies are lagging. The role of lysosomes in the neuro-pathophysiology of CLN5 disease represents an important topic since lysosomal proteins are directly involved in the primary mechanisms of neuronal injury occurring in various NCL forms. We developed and implemented a lysosome-focused, label-free quantitative proteomics approach, followed by functional validations in both CLN5-knockout neuronal-like cell lines and Cln5-/- mice, to unravel affected pathways and modifying factors involved in this disease scenario. Our results revealed a key role of CLN5p in lipid homeostasis and sphingolipid metabolism and highlighted mutual NCL biomarkers scored with high lysosomal confidence. A newly generated cln5 knockdown zebrafish model recapitulated most of the pathological features seen in NCL disease. To translate the findings from in-vitro and preclinical models to patients, we evaluated whether two FDA-approved drugs promoting autophagy via TFEB activation or inhibition of the glucosylceramide synthase could modulate in-vitro ROS and lipid overproduction, as well as alter the locomotor phenotype in zebrafish. In summary, our data advance the general understanding of disease mechanisms and modifying factors in CLN5 disease, which are recurring in other NCL forms, also stimulating new pharmacological treatments.


Neuronal Ceroid-Lipofuscinoses , Animals , Homeostasis , Humans , Lipids , Lysosomal Membrane Proteins/metabolism , Lysosomes/metabolism , Membrane Proteins/metabolism , Mice , Neuronal Ceroid-Lipofuscinoses/metabolism , Proteomics , Sphingolipids/metabolism , Zebrafish/metabolism
7.
Int J Mol Sci ; 22(16)2021 Aug 05.
Article En | MEDLINE | ID: mdl-34445111

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a multisystem hereditary ataxia associated with mutations in SACS, which encodes sacsin, a protein of still only partially understood function. Although mouse models of ARSACS mimic largely the disease progression seen in humans, their use in the validation of effective therapies has not yet been proposed. Recently, the teleost Danio rerio has attracted increasing attention as a vertebrate model that allows rapid and economical screening, of candidate molecules, and thus combines the advantages of whole-organism phenotypic assays and in vitro high-throughput screening assays. Through CRISPR/Cas9-based mutagenesis, we generated and characterized a zebrafish sacs-null mutant line that replicates the main features of ARSACS. The sacs-null fish showed motor impairment, hindbrain atrophy, mitochondrial dysfunction, and reactive oxygen species accumulation. As proof of principle for using these mutant fish in high-throughput screening studies, we showed that both acetyl-DL-leucine and tauroursodeoxycholic acid improved locomotor and biochemical phenotypes in sacs-/- larvae treated with these neuroprotective agents, by mediating significant rescue of the molecular functions altered by sacsin loss. Taken together, the evidence here reported shows the zebrafish to be a valuable model organism for the identification of novel molecular mechanisms and for efficient and rapid in vivo optimization and screening of potential therapeutic compounds. These findings may pave the way for new interventions targeting the earliest phases of Purkinje cell degeneration in ARSACS.


Heat-Shock Proteins/metabolism , Neuroprotective Agents/metabolism , Zebrafish/metabolism , Animals , Animals, Genetically Modified/metabolism , Ataxia/metabolism , Cerebellar Ataxia/metabolism , Disease Models, Animal , Disease Progression , Muscle Spasticity/metabolism , Mutation/genetics , Phenotype , Purkinje Cells/metabolism , Spinocerebellar Ataxias/congenital , Spinocerebellar Ataxias/metabolism
8.
Int J Mol Sci ; 22(5)2021 Mar 08.
Article En | MEDLINE | ID: mdl-33800494

Malignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene-expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients' overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E-selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small-molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer-driving role of the targets herewith identified.


Gene Expression Regulation, Neoplastic , Mesothelioma, Malignant , Neoplasm Proteins , Pleural Neoplasms , Female , Humans , Male , Mesothelioma, Malignant/genetics , Mesothelioma, Malignant/metabolism , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , Pleural Neoplasms/genetics , Pleural Neoplasms/metabolism
9.
Int J Cancer ; 148(8): 1887-1894, 2021 04 15.
Article En | MEDLINE | ID: mdl-33152124

We evaluated the association between germline genetic variants located within the 3'-untranlsated region (polymorphic 3'UTR, ie, p3UTR) of candidate genes involved in multiple myeloma (MM). We performed a case-control study within the International Multiple Myeloma rESEarch (IMMEnSE) consortium, consisting of 3056 MM patients and 1960 controls recruited from eight countries. We selected p3UTR of six genes known to act in different pathways relevant in MM pathogenesis, namely KRAS (rs12587 and rs7973623), VEGFA (rs10434), SPP1 (rs1126772), IRF4 (rs12211228) and IL10 (rs3024496). We found that IL10-rs3024496 was associated with increased risk of developing MM and with a worse overall survival of MM patients. The variant allele was assayed in a vector expressing eGFP chimerized with the IL10 3'-UTR and it was found functionally active following transfection in human myeloma cells. In this experiment, the A-allele caused a lower expression of the reporter gene and this was also in agreement with the in vivo expression of mRNA measured in whole blood as reported in the GTEx portal. Overall, these data are suggestive of an effect of the IL10-rs3024496 SNP on the regulation of IL10 mRNA expression and it could have clinical implications for better characterization of MM patients in terms of prognosis.


3' Untranslated Regions/genetics , Genetic Predisposition to Disease/genetics , Germ-Line Mutation , Multiple Myeloma/genetics , Adult , Aged , Case-Control Studies , Female , Gene Expression Regulation, Neoplastic , Gene Frequency , Genotype , Humans , Male , Middle Aged , Multiple Myeloma/diagnosis , Polymorphism, Single Nucleotide , RNA, Messenger/genetics , RNA, Messenger/metabolism , Risk Factors , Survival Analysis
10.
Ann Hum Genet ; 84(5): 417-422, 2020 09.
Article En | MEDLINE | ID: mdl-32281099

Perrault syndrome is a rare disorder characterized by ovarian dysgenesis, bilateral sensorineural hearing loss and associated with mutations in six mitochondrial proteins. Additional neurological features were also described. Herein, we report on a 27-year-old woman with Perrault syndrome (PS), moderate ataxia and axonal sensory-motor peripheral neuropathy in whom we identified compound heterozygous mutations in the TWNK gene (p.Val507Ile and the novel p.Phe248Ser variant). Fewer than 30 patients with PS have been reported worldwide. Neurological involvement is more frequently associated with mutations in TWNK and indicates possible genotype-phenotype correlations. TWNK mutations should be searched in patients with sensory ataxia, early onset bilateral sensorineural hearing loss, and ovarian dysfunction in women.


DNA Helicases/genetics , Gonadal Dysgenesis, 46,XX/genetics , Hearing Loss, Sensorineural/genetics , Mitochondrial Proteins/genetics , Adult , Amino Acid Sequence , DNA Mutational Analysis , Female , Humans , Mutation , Mutation, Missense , Pedigree
11.
Neurobiol Dis ; 141: 104880, 2020 07.
Article En | MEDLINE | ID: mdl-32344152

Mitochondrial ribosomal protein large 24 (MRPL24) is 1 of the 82 protein components of mitochondrial ribosomes, playing an essential role in the mitochondrial translation process. We report here on a baby girl with cerebellar atrophy, choreoathetosis of limbs and face, intellectual disability and a combined defect of complexes I and IV in muscle biopsy, caused by a homozygous missense mutation identified in MRPL24. The variant predicts a Leu91Pro substitution at an evolutionarily conserved site. Using human mutant cells and the zebrafish model, we demonstrated the pathological role of the identified variant. In fact, in fibroblasts we observed a significant reduction of MRPL24 protein and of mitochondrial respiratory chain complex I and IV subunits, as well a markedly reduced synthesis of the mtDNA-encoded peptides. In zebrafish we demonstrated that the orthologue gene is expressed in metabolically active tissues, and that gene knockdown induced locomotion impairment, structural defects and low ATP production. The motor phenotype was complemented by human WT but not mutant cRNA. Moreover, sucrose density gradient fractionation showed perturbed assembly of large subunit mitoribosomal proteins, suggesting that the mutation leads to a conformational change in MRPL24, which is expected to cause an aberrant interaction of the protein with other components of the 39S mitoribosomal subunit.


Mitochondrial Proteins/genetics , Movement Disorders/genetics , Ribosomal Proteins/genetics , Animals , Cerebellum/pathology , Female , Humans , Infant , Leviviridae , Male , Movement Disorders/pathology , Quadriceps Muscle/pathology , Zebrafish
12.
Cell Death Discov ; 6: 18, 2020.
Article En | MEDLINE | ID: mdl-32257390

CLN5 disease is a rare form of late-infantile neuronal ceroid lipofuscinosis (NCL) caused by mutations in the CLN5 gene that encodes a protein whose primary function and physiological roles remains unresolved. Emerging lines of evidence point to mitochondrial dysfunction in the onset and progression of several forms of NCL, offering new insights into putative biomarkers and shared biological processes. In this work, we employed cellular and murine models of the disease, in an effort to clarify disease pathways associated with CLN5 depletion. A mitochondria-focused quantitative proteomics approach followed by functional validations using cell biology and immunofluorescence assays revealed an impairment of mitochondrial functions in different CLN5 KO cell models and in Cln5 - /- cerebral cortex, which well correlated with disease progression. A visible impairment of autophagy machinery coupled with alterations of key parameters of mitophagy activation process functionally linked CLN5 protein to the process of neuronal injury. The functional link between impaired cellular respiration and activation of mitophagy pathways in the human CLN5 disease condition was corroborated by translating organelle-specific proteome findings to CLN5 patients' fibroblasts. Our study highlights the involvement of CLN5 in activation of mitophagy and mitochondrial homeostasis offering new insights into alternative strategies towards the CLN5 disease treatment.

13.
Front Neurol ; 11: 603774, 2020.
Article En | MEDLINE | ID: mdl-33584503

Although the genetic basis of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) has been uncovered, our poor understanding of disease mechanisms requires new light on functional pathways and modifying factors to improve early diagnostic strategies and offer alternative treatment options in a rare condition with no cure. Investigation of the pathologic state combining disease models and quantitative omic approach might improve biomarkers discovery with possible implications in patients' diagnoses. In this study, we analyzed proteomics data obtained using the SomaLogic technology, comparing cell lysates from ARSACS patients and from a SACS KO SH-SY5Y neuroblastoma cell model. Single-stranded deoxyoligonucleotides, selected in vitro from large random libraries, bound and quantified molecular targets related to the neuroinflammation signaling pathway and to neuronal development. Changes in protein levels were further analyzed by bioinformatics and network approaches to identify biomarkers of ARSACS and functional pathways impaired in the disease. We identified novel significantly dysregulated biological processes related to neuroinflammation, synaptogenesis, and engulfment of cells in patients and in KO cells compared with controls. Among the differential expressed proteins found in this work, we identified several proteins encoded by genes already known to be mutated in other forms of neurodegeneration. This finding suggests that common dysfunctional networks could be therapeutic targets for future investigations.

14.
Front Physiol ; 10: 1219, 2019.
Article En | MEDLINE | ID: mdl-31611809

Autophagy is a degradative process of cellular components accomplished through an autophagosomal-lysosomal pathway. It is an evolutionary conserved mechanism present in all eukaryotic cells, and it plays a fundamental role in maintaining tissue homeostasis both in vertebrates and invertebrates. Autophagy accompanies tissue remodeling during organ differentiation. Several autophagy-related genes and proteins show significant upregulations following nutrient shortage (i.e., starvation). In our previous study, we found that in female giant freshwater prawns subjected to a short period of starvation autophagy was up-regulated in consonant with ovarian maturation and oocyte differentiation. Whether and how starvation-induced autophagy impacts on testicular maturation and spermatogenesis of the male prawns remained to be investigated. In this study, we analyzed the effects of starvation on histological and cellular changes in the testis of the giant freshwater prawn Macrobrachium rosenbergii that paralleled the induction of autophagy. Under short starvation condition, the male prawns showed increased gonado-somatic index, increased size, and late stage of maturation of seminiferous tubules, which contained increased number of spermatozoa. Concurrently, the number of autophagy vacuoles and autophagy flux, as monitored by transmission electron microscopy and the autophagic marker LC3, increased in the testicular cells, indicating that a short period of starvation could induce testicular maturation and spermatogenesis in male M. rosenbergii along with modulation of autophagy.

15.
Sci Rep ; 9(1): 11878, 2019 08 15.
Article En | MEDLINE | ID: mdl-31417125

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare early-onset neurological disease caused by mutations in SACS, which encodes sacsin. The complex architecture of sacsin suggests that it could be a key player in cellular protein quality control system. Molecular chaperones that operate in protein folding/unfolding and assembly/disassembly patterns have been described as essential modulators of selectivity during the autophagy process. We performed RNA-sequencing analysis to generate a whole-genome molecular signature profile of sacsin knockout cells. Using data analysis of biological processes significantly disrupted due to loss of sacsin, we confirmed the presence of decreased mitochondrial function associated with increased oxidative stress, and also provided a demonstration of a defective autophagic pathway in sacsin-depleted cells. Western blotting assays revealed decreased expression of LC3 and increased levels of p62 even after treatment with the lysosomal inhibitor bafilomycin A1, indicating impairment of the autophagic flux. Moreover, we found reduced co-immunolocalization of the autophagosome marker LC3 with lysosomal and mitochondrial markers suggesting fusion inhibition of autophagic compartments and subsequent failed cargo degradation, in particular failed degradation of damaged mitochondria. Pharmacological up-regulation of autophagy restored correct autophagic flux in sacsin knockout cells. These results corroborate the hypothesis that sacsin may play a role in autophagy. Chemical manipulation of this pathway might represent a new target to alleviate clinical and pathological symptoms, delaying the processes of neurodegeneration in ARSACS.


Autophagy/genetics , Gene Expression Profiling , Genetic Predisposition to Disease , Heat-Shock Proteins/genetics , Muscle Spasticity/genetics , Spinocerebellar Ataxias/congenital , Transcriptome , CRISPR-Cas Systems , Cells, Cultured , Computational Biology/methods , Gene Expression Profiling/methods , Gene Knockout Techniques , Gene Ontology , Genetic Association Studies , Humans , Mitochondria/genetics , Mitochondria/metabolism , Muscle Spasticity/diagnosis , Muscle Spasticity/metabolism , Oxidative Phosphorylation , Proteasome Endopeptidase Complex/metabolism , Spinocerebellar Ataxias/diagnosis , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/metabolism , TOR Serine-Threonine Kinases/metabolism , Ubiquitin/metabolism
16.
Cell Commun Signal ; 17(1): 39, 2019 05 02.
Article En | MEDLINE | ID: mdl-31046771

BACKGROUND: In the event of amino acid starvation, the cell activates two main protective pathways: Amino Acid starvation Response (AAR), to inhibit global translation, and autophagy, to recover the essential substrates from degradation of redundant self-components. Whether and how AAR and autophagy (ATG) are cross-regulated and at which point the two regulatory pathways intersect remain unknown. Here, we provide experimental evidence that the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) specifically located at the lysosome level links the AAR with the autophagy pathway. METHODS: As an inducer of the AAR, we used halofuginone (HF), an alkaloid that binds to the prolyl-tRNA synthetase thus mimicking the unavailability of proline (PRO). Induction of AAR was determined assessing the phosphorylation of the eukaryotic translation initiation factor (eIF) 2α. Autophagy was monitored by assessing the processing and accumulation of microtubule-associated protein 1 light chain 3 isoform B (LC3B) and sequestosome-1 (p62/SQSTM1) levels. The activity of mTORC1 was monitored through assessment of the phosphorylation of mTOR, (rp)S6 and 4E-BP1. Global protein synthesis was determined by puromycin incorporation assay. mTORC1 presence on the membrane of the lysosomes was monitored by cell fractionation and mTOR expression was determined by immunoblotting. RESULTS: In three different types of human cancer cells (thyroid cancer WRO cells, ovarian cancer OAW-42 cells, and breast cancer MCF-7 cells), HF induced both the AAR and the autophagy pathways time-dependently. In WRO cells, which showed the strongest induction of autophagy and of AAR, global protein synthesis was little if any affected. Consistently, 4E-BP1 and (rp)S6 were phosphorylated. Concomitantly, mTOR expression and activation declined along with its detachment from the lysosomes and its degradation by the proteasome, and with the nuclear translocation of transcription factor EB (TFEB), a transcription factor of many ATG genes. The extra supplementation of proline rescued all these effects. CONCLUSIONS: We demonstrate that the AAR and autophagy are mechanistically linked at the level of mTORC1, and that the lysosome is the central hub of the cross-talk between these two metabolic stress responses.


Autophagy/drug effects , Mechanistic Target of Rapamycin Complex 1/metabolism , Piperidines/pharmacology , Proteasome Endopeptidase Complex/metabolism , Protein Synthesis Inhibitors/pharmacology , Quinazolinones/pharmacology , Amino Acids/deficiency , Amino Acids/metabolism , Eukaryotic Initiation Factor-2/metabolism , Humans , MCF-7 Cells , Microtubule-Associated Proteins/metabolism , Sequestosome-1 Protein/metabolism
17.
Neurogenetics ; 20(1): 45-49, 2019 03.
Article En | MEDLINE | ID: mdl-30680480

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset neurodevelopmental disorder characterized by the association of spastic ataxia and sensorimotor neuropathy. Additional features include retinal changes and cognitive impairment. Today, next-generation sequencing (NGS) techniques are allowing the rapid identification of a growing number of missense variants, even in less typical forms of the disease, but the pathogenic significance of these changes is often difficult to establish on the basis of classic bioinformatics criteria and genotype/phenotype correlations. Herein, we describe two novel cases of missense mutations in SACS. The two individuals were identified during the genetic screening of a large cohort of patients with inherited ataxias. We discuss how protein studies and specialized ophthalmological investigations could represent useful pointers for the interpretation of genetic data. Combination of these tools with NGS for rapid genotyping might help to identify new true ARSACS cases.


Brain/pathology , Cerebellar Ataxia/pathology , Mitochondria/pathology , Muscle Spasticity/genetics , Spinocerebellar Ataxias/congenital , Cerebellar Ataxia/diagnosis , Cerebellar Ataxia/genetics , Child , Female , Genes, Recessive , Humans , Muscle Spasticity/diagnosis , Muscle Spasticity/pathology , Mutation/genetics , Phenotype , Spinocerebellar Ataxias/diagnosis , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/pathology
18.
Orphanet J Rare Dis ; 13(1): 170, 2018 09 26.
Article En | MEDLINE | ID: mdl-30257713

BACKGROUND: Dystroglycanopathy (α-DG) is a relatively common, clinically and genetically heterogeneous category of congenital forms of muscular dystrophy (CMD) and limb-girdle muscular dystrophy (LGMD) associated with hypoglycosylated α-dystroglycan. To date, mutations in at least 19 genes have been associated with α-DG. One of them, GMPPB, encoding the guanosine-diphosphate-mannose (GDP-mannose) pyrophosphorylase B protein, has recently been associated with a wide clinical spectrum ranging from severe Walker-Warburg syndrome to pseudo-metabolic myopathy and even congenital myasthenic syndromes. We re-sequenced the full set of known disease genes in 73 Italian patients with evidence of either reduced or nearly absent α-dystroglycan to assess genotype-phenotype correlations in this cohort. We used innovative bioinformatic tools to calculate the effects of all described GMPPB mutations on protein function and attempted to correlate them with phenotypic expressions. RESULTS: We identified 13 additional cases from 12 families and defined seven novel mutations. Patients displayed variable phenotypes including less typical pictures, ranging from asymptomatic hyperCKemia, to arthrogryposis and congenital clubfoot at birth, and also showed neurodevelopmental comorbidities, such as seizures and ataxic gait, as well as autism-spectrum disorder, which is seldom described in clinical reports of dystroglycanopathies. We also demonstrated that few mutations recur in the Italian GMPPB-mutated population and that alterations of protein stability are the main effects of GMPPB missense variants. CONCLUSION: This work adds to the data on genotype-phenotype correlations in α-DG and offers new bionformatic tools to provide the conceptual framework needed to understand the complexity of these disorders.


Muscular Dystrophies, Limb-Girdle/metabolism , Muscular Dystrophies/metabolism , Adult , Aged , Cross-Sectional Studies , Dystroglycans/metabolism , Female , Genetic Association Studies , Humans , Male , Middle Aged , Muscular Dystrophies/genetics , Muscular Dystrophies, Limb-Girdle/genetics , Mutation/genetics , Mutation, Missense/genetics , Nucleotidyltransferases/genetics , Nucleotidyltransferases/metabolism , Young Adult
19.
Front Physiol ; 9: 613, 2018.
Article En | MEDLINE | ID: mdl-29910737

Invertebrate neuropeptide F-I (NPF-I), much alike its mammalian homolog neuropeptide Y, influences several physiological processes, including circadian rhythms, cortical excitability, stress response, and food intake behavior. Given the role of autophagy in the metabolic stress response, we investigated the effect of NPF-1 on autophagy during fasting and feeding conditions in the hepatopancreas and muscle tissues of the male giant freshwater prawn Macrobrachium rosenbergii. Starvation up-regulated the expression of the autophagy marker LC3 in both tissues. Yet, based on the relative levels of the autophagosome-associated LC3-II isoform and of its precursor LC3-I, the hepatopancreas was more responsive than the muscle to starvation-induced autophagy. Injection of NPF-I inhibited the autophagosome formation in the hepatopancreas of fasting prawns. Relative to the body weight, the muscle weight was not affected, while that of the hepatopancreas decreased upon starvation and NPF-1 treatment could largely prevent such weight loss. Thus, the hepatopancreas is the reserve organ for the nutrient homeostasis during starvation and NPF-I plays a crucial role in the balancing of energy expenditure and energy intake during starvation by modulating autophagy.

20.
Front Physiol ; 8: 300, 2017.
Article En | MEDLINE | ID: mdl-28553234

Limitation of food availability (starvation) is known to influence the reproductive ability of animals. Autophagy is a lysosomal driven degradation process that protects the cell under metabolic stress conditions, such as during nutrient shortage. Whether, and how starvation-induced autophagy impacts on the maturation and function of reproductive organs in animals are still open questions. In this study, we have investigated the effects of starvation on histological and cellular changes that may be associated with autophagy in the ovary of the giant freshwater prawn, Macrobachium rosenbergii. To this end, the female prawns were daily fed (controls) or unfed (starvation condition) for up to 12 days, and the ovary tissue was analyzed at different time-points. Starvation triggered ovarian maturation, and concomitantly increased the expression of autophagy markers in vitellogenic oocytes. The immunoreactivities for autophagy markers, including Beclin1, LC3-II, and Lamp1, were enhanced in the late oocytes within the mature ovaries, especially at the vitellogenic stages. These markers co-localized with vitellin in the yolk granules within the oocytes, suggesting that autophagy induced by starvation could drive vitellin utilization, thus promoting ovarian maturation.

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