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1.
Artículo en Inglés | MEDLINE | ID: mdl-38317457

RESUMEN

BACKGROUND: Clinical variability among individuals with heterozygous pathogenic/likely pathogenic (P/LP) variants in the COL4A3/COL4A4 genes (also called autosomal dominant Alport syndrome or COL4A3/COL4A4 related disorder) is huge; many individuals are asymptomatic or show microhematuria, while others may develop proteinuria and chronic kidney disease (CKD). The prevalence of simple kidney cysts (KC) in the general population varies according to age, and patients with advanced CKD are prone to have them. A possible association between heterozygous COL4A3, COL4A4, and COL4A5 P/LP variants and KC has been described in small cohorts. The presence of KC in a multicenter cohort of individuals with heterozygous P/LP variants in the COL4A3/COL4A4 genes is assessed in this study. METHODS: We evaluated the presence of KC by ultrasound in 157 individuals with P/LP variants in COL4A3 (40.7%) or COL4A4 (53.5%) without kidney replacement therapy. The association between presence of KC and age, proteinuria, eGFR, and causative gene was analyzed. Prevalence of KC was compared with historical case series in the general population. RESULTS: Half of the individuals with P/LP variants in COL4A3/COL4A4 showed KC, which is a significantly higher percentage than in the general population. Only 3.8% (6/157) had cystic nephromegaly. Age and eGFR showed an association with the presence of KC (p<0.001). No association was found between KC and proteinuria, sex, or causative gene. CONCLUSIONS: Individuals with COL4A3/COL4A4 P/LP variants are prone to develop KC more frequently than the general population, and their presence is related to age and to eGFR. Neither proteinuria, sex nor the causative gene influences the presence of KC in these individuals.

2.
Am J Hum Genet ; 109(8): 1458-1471, 2022 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-35809576

RESUMEN

Although the evolutionary history of the X chromosome indicates its specialization in male fitness, its role in spermatogenesis has largely been unexplored. Currently only three X chromosome genes are considered of moderate-definitive diagnostic value. We aimed to provide a comprehensive analysis of all X chromosome-linked protein-coding genes in 2,354 azoospermic/cryptozoospermic men from four independent cohorts. Genomic data were analyzed and compared with data in normozoospermic control individuals and gnomAD. While updating the clinical significance of known genes, we propose 21 recurrently mutated genes strongly associated with and 34 moderately associated with azoospermia/cryptozoospermia not previously linked to male infertility (novel). The most frequently affected prioritized gene, RBBP7, was found mutated in ten men across all cohorts, and our functional studies in Drosophila support its role in germ stem cell maintenance. Collectively, our study represents a significant step towards the definition of the missing genetic etiology in idiopathic severe spermatogenic failure and significantly reduces the knowledge gap of X-linked genetic causes of azoospermia/cryptozoospermia contributing to the development of future diagnostic gene panels.


Asunto(s)
Azoospermia , Infertilidad Masculina , Oligospermia , Azoospermia/genética , Humanos , Infertilidad Masculina/genética , Masculino , Espermatogénesis/genética , Cromosoma X
3.
Clin Kidney J ; 15(5): 912-921, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35498884

RESUMEN

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease and shows a wide phenotype. Only patients with rapid progression (RP) are included in clinical trials or are approved to receive disease-modifying drugs. This study aims at comparing different available predictive tools in ADPKD with the Mayo classification (MC) identification of rapid progressors based on high total kidney volume (TKV) according to age. Methods: A total of 164 ADPKD patients were recruited retrospectively from a single centre. The performance of diverse tools to identify RP defined as being in MC categories 1C-1E was assessed. Results: A total of 118 patients were MC 1C-1E. The algorithm developed by the European Renal Association-European Dialysis and Transplant Association Working Group on Inherited Kidney Disorders/European Renal Best Practice had a low sensitivity in identifying MC 1C-1E. The sensitivity and specificity of TKV to predict RP depend on the cut-off used. A kidney length of >16.5 cm before age 45 years has high specificity but low sensitivity. Assessing the MC by ultrasonography had high levels of agreement with magnetic resonance imaging (MRI) data, especially for 1A, 1D and 1E. The estimated glomerular filtration rate (eGFR) decline was very sensitive but had low specificity. In contrast, the Predicting Renal Outcome in Polycystic Kidney Disease (PROPKD) score was very specific but had poor sensitivity. Having hypertension before 35 years of age is a good clinical predictor of MC 1C-1E. Family history can be of help in suggesting RP, but by itself it lacks sufficient sensitivity and specificity. Conclusions: The MC by ultrasonography could be an option in hospitals with limited access to MRI as it performs well generally, and especially at the extremes of the MC, i.e. classes 1A, 1D and 1E. The eGFR decline is sensitive but not very specific when compared with the MC, whereas the PROPKD score is very specific but has low sensitivity. Integrating the different tools currently available to determine RP should facilitate the identification of rapid progressors among patients with ADPKD.

4.
Nephrol Dial Transplant ; 37(10): 1906-1915, 2022 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-34610128

RESUMEN

BACKGROUND: Proteinuria is a well-known risk factor for progressive kidney impairment. Recently, C-terminal cubilin (CUBN) variants have been associated with isolated proteinuria without progression of kidney disease. METHODS: Genetic testing of 347 families with proteinuria of suspected monogenic cause was performed by next-generation sequencing of a custom-designed kidney disease gene panel. Families with CUBN biallelic proteinuria-causing variants were studied at the clinical, genetic, laboratory and pathologic levels. RESULTS: Twelve families (15 patients) bearing homozygous or compound heterozygous proteinuria-causing variants in the C-terminal CUBN gene were identified, representing 3.5% of the total cohort. We identified 14 different sequence variants, five of which were novel. The median age at diagnosis of proteinuria was 4 years (range 9 months to 44 years), and in most cases proteinuria was detected incidentally. Thirteen patients had moderate to severe proteinuria at diagnosis without nephrotic syndrome. These patients showed lack of response to angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) treatment, normal kidney biopsy and preservation of normal kidney function over time. The two remaining patients presented a more severe phenotype, likely caused by associated comorbidities. CONCLUSIONS: Identification of C-terminal pathogenic CUBN variants is diagnostic of an entity characterized by glomerular proteinuria, normal kidney histology and lack of response to ACEi/ARB treatment. This study adds evidence and increases awareness about albuminuria caused by C-terminal variants in the CUBN gene, which is a benign condition usually diagnosed in childhood with preserved renal function until adulthood.


Asunto(s)
Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Humanos , Proteinuria/patología , Receptores de Superficie Celular/genética
5.
Nephrol Dial Transplant ; 37(4): 687-696, 2022 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-33532864

RESUMEN

BACKGROUND: Inherited kidney diseases are one of the leading causes of chronic kidney disease (CKD) that manifests before the age of 30 years. Precise clinical diagnosis of early-onset CKD is complicated due to the high phenotypic overlap, but genetic testing is a powerful diagnostic tool. We aimed to develop a genetic testing strategy to maximize the diagnostic yield for patients presenting with early-onset CKD and to determine the prevalence of the main causative genes. METHODS: We performed genetic testing of 460 patients with early-onset CKD of suspected monogenic cause using next-generation sequencing of a custom-designed kidney disease gene panel in addition to targeted screening for c.428dupC MUC1. RESULTS: We achieved a global diagnostic yield of 65% (300/460), which varied depending on the clinical diagnostic group: 77% in cystic kidney diseases, 76% in tubulopathies, 67% in autosomal dominant tubulointerstitial kidney disease, 61% in glomerulopathies and 38% in congenital anomalies of the kidney and urinary tract. Among the 300 genetically diagnosed patients, the clinical diagnosis was confirmed in 77%, a specific diagnosis within a clinical diagnostic group was identified in 15%, and 7% of cases were reclassified. Of the 64 causative genes identified in our cohort, 7 (COL4A3, COL4A4, COL4A5, HNF1B, PKD1, PKD2 and PKHD1) accounted for 66% (198/300) of the genetically diagnosed patients. CONCLUSIONS: Two-thirds of patients with early-onset CKD in this cohort had a genetic cause. Just seven genes were responsible for the majority of diagnoses. Establishing a genetic diagnosis is crucial to define the precise aetiology of CKD, which allows accurate genetic counselling and improved patient management.


Asunto(s)
Enfermedades Renales Poliquísticas , Insuficiencia Renal Crónica , Adulto , Femenino , Pruebas Genéticas , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Riñón , Masculino , Mutación , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/genética
6.
Am J Kidney Dis ; 78(4): 560-570.e1, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33838161

RESUMEN

RATIONALE & OBJECTIVE: Alport syndrome is a common genetic kidney disease accounting for approximately 2% of patients receiving kidney replacement therapy (KRT). It is caused by pathogenic variants in the gene COL4A3, COL4A4, or COL4A5. The aim of this study was to evaluate the clinical and genetic spectrum of patients with autosomal dominant Alport syndrome (ADAS). STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 82 families (252 patients) with ADAS were studied. Clinical, genetic, laboratory, and pathology data were collected. OBSERVATIONS: A pathogenic DNA variant in COL4A3 was identified in 107 patients (35 families), whereas 133 harbored a pathogenic variant in COL4A4 (43 families). Digenic/complex inheritance was observed in 12 patients. Overall, the median kidney survival was 67 (95% CI, 58-73) years, without significant differences across sex (P=0.8), causative genes (P=0.6), or type of variant (P=0.9). Microhematuria was the most common kidney manifestation (92.1%), and extrarenal features were rare. Findings on kidney biopsies ranged from normal to focal segmental glomerulosclerosis. The slope of estimated glomerular filtration rate change was-1.46 (-1.66 to-1.26) mL/min/1.73m2 per year for the overall group, with no significant differences between ADAS genes (P=0.2). LIMITATIONS: The relatively small size of this series from a single country, potentially limiting generalizability. CONCLUSIONS: Patients with ADAS have a wide spectrum of clinical presentations, ranging from asymptomatic to kidney failure, a pattern not clearly related to the causative gene or type of variant. The diversity of ADAS phenotypes contributes to its underdiagnosis in clinical practice.


Asunto(s)
Autoantígenos/genética , Colágeno Tipo IV/genética , Pruebas Genéticas/métodos , Variación Genética/genética , Nefritis Hereditaria/diagnóstico , Nefritis Hereditaria/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nefritis Hereditaria/epidemiología , Insuficiencia Renal/diagnóstico , Insuficiencia Renal/epidemiología , Insuficiencia Renal/genética , Estudios Retrospectivos , Adulto Joven
7.
J Hum Genet ; 66(8): 795-803, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33654185

RESUMEN

Focal segmental glomerulosclerosis (FSGS) is a histological lesion with many causes, including inherited genetic defects, with significant proteinuria being the predominant clinical finding at presentation. FSGS is considered as a podocyte disease due to the fact that in the majority of patients with FSGS, the lesion results from defects in the podocyte structure. However, FSGS does not result exclusively from podocyte-associated genes. In this study, we used a genetic approach based on targeted next-generation sequencing (NGS) of 242 genes to identify the genetic cause of FSGS in seven Tunisian families. The sequencing results revealed the presence of eight distinct mutations including seven newly discovered ones: the c.538G>A (p.V180M) in NPHS2, c.5186G>A (p.R1729Q) in PLCE1 and c.232A>C (p.I78L) in PAX2 and five novel mutations in COL4A3 and COL4A4 genes. Four mutations (c.209G>A (p.G70D), c.725G>A (p.G242E), c.2225G>A (p.G742E), and c. 1681_1698del) were detected in COL4A3 gene and one mutation (c.1424G>A (p.G475D)) was found in COL4A4. In summary, NGS of a targeted gene panel is an ideal approach for the genetic testing of FSGS with multiple possible underlying etiologies. We have demonstrated that not only podocyte genes but also COL4A3/4 mutations should be considered in patients with FSGS.


Asunto(s)
Autoantígenos/genética , Colágeno Tipo IV/genética , Colágeno/genética , Glomeruloesclerosis Focal y Segmentaria/genética , Factor de Transcripción PAX2/genética , Adulto , Femenino , Enfermedades Genéticas Congénitas/diagnóstico , Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Glomeruloesclerosis Focal y Segmentaria/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , Mutación Missense , Linaje , Podocitos/fisiología , Túnez , Adulto Joven
8.
Genet Med ; 22(12): 1956-1966, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32741963

RESUMEN

PURPOSE: Azoospermia affects 1% of men and it can be the consequence of spermatogenic maturation arrest (MA). Although the etiology of MA is likely to be of genetic origin, only 13 genes have been reported as recurrent potential causes of MA. METHODS: Exome sequencing in 147 selected MA patients (discovery cohort and two validation cohorts). RESULTS: We found strong evidence for five novel genes likely responsible for MA (ADAD2, TERB1, SHOC1, MSH4, and RAD21L1), for which mouse knockout (KO) models are concordant with the human phenotype. Four of them were validated in the two independent MA cohorts. In addition, nine patients carried pathogenic variants in seven previously reported genes-TEX14, DMRT1, TEX11, SYCE1, MEIOB, MEI1, and STAG3-allowing to upgrade the clinical significance of these genes for diagnostic purposes. Our meiotic studies provide novel insight into the functional consequences of the variants, supporting their pathogenic role. CONCLUSION: Our findings contribute substantially to the development of a pre-testicular sperm extraction (TESE) prognostic gene panel. If properly validated, the genetic diagnosis of complete MA prior to surgical interventions is clinically relevant. Wider implications include the understanding of potential genetic links between nonobstructive azoospermia (NOA) and cancer predisposition, and between NOA and premature ovarian failure.


Asunto(s)
Azoospermia , Azoospermia/diagnóstico , Azoospermia/genética , Proteínas de Ciclo Celular/genética , Proteínas de Unión al ADN/genética , Disección , Exoma/genética , Humanos , Masculino , Testículo , Secuenciación del Exoma
9.
BMC Nephrol ; 20(1): 126, 2019 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-30975089

RESUMEN

BACKGROUND: Galloway-Mowat syndrome (GAMOS) is a rare autosomal recessive disorder characterized by early-onset nephrotic syndrome and microcephaly with brain anomalies. WDR73 pathogenic variants were described as the first genetic cause of GAMOS and, very recently, four novel causative genes, OSGEP, LAGE3, TP53RK, and TPRKB, have been identified. CASE PRESENTATION: We present the clinical and genetic characteristics of two unrelated infants with clinical suspicion of GAMOS who were born from consanguineous parents. Both patients showed a similar clinical presentation, with early-onset nephrotic syndrome, microcephaly, brain atrophy, developmental delay, axial hypotonia, and early fatality. We identified two novel likely disease-causing variants in the OSGEP gene. These two cases, in conjunction with the findings of a literature review, indicate that OSGEP pathogenic variants are associated with an earlier onset of nephrotic syndrome and shorter life expectancy than WDR73 pathogenic variants. CONCLUSIONS: Our findings expand the spectrum of pathogenic variants in the OSGEP gene and, taken in conjunction with the results of the literature review, suggest that the OSGEP gene should be considered the main known monogenic cause of GAMOS. Early genetic diagnosis of GAMOS is of paramount importance for genetic counseling and family planning.


Asunto(s)
Hernia Hiatal , Riñón/patología , Metaloendopeptidasas/genética , Microcefalia , Nefrosis , Síndrome Nefrótico , Atrofia , Biopsia , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Deterioro Clínico , Resultado Fatal , Femenino , Predisposición Genética a la Enfermedad , Hernia Hiatal/complicaciones , Hernia Hiatal/diagnóstico , Hernia Hiatal/genética , Hernia Hiatal/mortalidad , Homocigoto , Humanos , Lactante , Esperanza de Vida , Masculino , Microcefalia/complicaciones , Microcefalia/diagnóstico , Microcefalia/etiología , Microcefalia/genética , Microcefalia/mortalidad , Nefrosis/complicaciones , Nefrosis/diagnóstico , Nefrosis/genética , Nefrosis/mortalidad , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/etiología , Síndrome Nefrótico/genética
10.
Genome Biol ; 19(1): 193, 2018 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-30428903

RESUMEN

BACKGROUND: Integrating demography and adaptive evolution is pivotal to understanding the evolutionary history and conservation of great apes. However, little is known about the adaptive evolution of our closest relatives, in particular if and to what extent adaptions to environmental differences have occurred. Here, we used whole-genome sequencing data from critically endangered orangutans from North Sumatra (Pongo abelii) and Borneo (P. pygmaeus) to investigate adaptive responses of each species to environmental differences during the Pleistocene. RESULTS: Taking into account the markedly disparate demographic histories of each species after their split ~ 1 Ma ago, we show that persistent environmental differences on each island had a strong impact on the adaptive evolution of the genus Pongo. Across a range of tests for positive selection, we find a consistent pattern of between-island and species differences. In the more productive Sumatran environment, the most notable signals of positive selection involve genes linked to brain and neuronal development, learning, and glucose metabolism. On Borneo, however, positive selection comprised genes involved in lipid metabolism, as well as cardiac and muscle activities. CONCLUSIONS: We find strikingly different sets of genes appearing to have evolved under strong positive selection in each species. In Sumatran orangutans, selection patterns were congruent with well-documented cognitive and behavioral differences between the species, such as a larger and more complex cultural repertoire and higher degrees of sociality. However, in Bornean orangutans, selective responses to fluctuating environmental conditions appear to have produced physiological adaptations to generally lower and temporally more unpredictable food supplies.


Asunto(s)
Adaptación Biológica , Evolución Biológica , Variación Genética , Genética de Población , Genoma , Pongo/genética , Animales , Especiación Genética , Filogenia , Pongo/clasificación
11.
Genome Biol Evol ; 10(11): 2899-2905, 2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30364947

RESUMEN

The study of segmental duplications (SDs) and copy-number variants (CNVs) is of great importance in the fields of genomics and evolution. However, SDs and CNVs are usually excluded from genome-wide scans for natural selection. Because of high identity between copies, SDs and CNVs that are not included in reference genomes are prone to be collapsed-that is, mistakenly aligned to the same region-when aligning sequence data from single individuals to the reference. Such collapsed duplications are additionally challenging because concerted evolution between duplications alters their site frequency spectrum and linkage disequilibrium patterns. To investigate the potential effect of collapsed duplications upon natural selection scans we obtained expectations for four summary statistics from simulations of duplications evolving under a range of interlocus gene conversion and crossover rates. We confirm that summary statistics traditionally used to detect the action of natural selection on DNA sequences cannot be applied to SDs and CNVs since in some cases values for known duplications mimic selective signatures. As a proof of concept of the pervasiveness of collapsed duplications, we analyzed data from the 1,000 Genomes Project. We find that, within regions identified as variable in copy number, diversity between individuals with the duplication is consistently higher than between individuals without the duplication. Furthermore, the frequency of single nucleotide variants (SNVs) deviating from Hardy-Weinberg Equilibrium is higher in individuals with the duplication, which strongly suggests that higher diversity is a consequence of collapsed duplications and incorrect evaluation of SNVs within these CNV regions.


Asunto(s)
Variaciones en el Número de Copia de ADN , Conversión Génica , Modelos Genéticos , Duplicaciones Segmentarias en el Genoma , Selección Genética , Simulación por Computador , Genoma , Estadística como Asunto
12.
Immunity ; 49(4): 709-724.e8, 2018 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-30291028

RESUMEN

B cells thwart antigenic aggressions by releasing immunoglobulin M (IgM), IgG, IgA, and IgE, which deploy well-understood effector functions. In contrast, the role of secreted IgD remains mysterious. We found that some B cells generated IgD-secreting plasma cells following early exposure to external soluble antigens such as food proteins. Secreted IgD targeted basophils by interacting with the CD44-binding protein galectin-9. When engaged by antigen, basophil-bound IgD increased basophil secretion of interleukin-4 (IL-4), IL-5, and IL-13, which facilitated the generation of T follicular helper type 2 cells expressing IL-4. These germinal center T cells enhanced IgG1 and IgE but not IgG2a and IgG2b responses to the antigen initially recognized by basophil-bound IgD. In addition, IgD ligation by antigen attenuated allergic basophil degranulation induced by IgE co-ligation. Thus, IgD may link B cells with basophils to optimize humoral T helper type 2-mediated immunity against common environmental soluble antigens.


Asunto(s)
Basófilos/inmunología , Galectinas/inmunología , Receptores de Hialuranos/inmunología , Inmunoglobulina D/inmunología , Células Th2/inmunología , Animales , Basófilos/metabolismo , Línea Celular Tumoral , Células Cultivadas , Galectinas/genética , Galectinas/metabolismo , Perfilación de la Expresión Génica/métodos , Humanos , Receptores de Hialuranos/genética , Receptores de Hialuranos/metabolismo , Inmunoglobulina D/metabolismo , Inmunoglobulina E/inmunología , Inmunoglobulina E/metabolismo , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Interleucina-4/genética , Interleucina-4/inmunología , Interleucina-4/metabolismo , Ratones Endogámicos BALB C , Unión Proteica , Células Th2/metabolismo
13.
Curr Biol ; 27(22): 3487-3498.e10, 2017 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-29103940

RESUMEN

Six extant species of non-human great apes are currently recognized: Sumatran and Bornean orangutans, eastern and western gorillas, and chimpanzees and bonobos [1]. However, large gaps remain in our knowledge of fine-scale variation in hominoid morphology, behavior, and genetics, and aspects of great ape taxonomy remain in flux. This is particularly true for orangutans (genus: Pongo), the only Asian great apes and phylogenetically our most distant relatives among extant hominids [1]. Designation of Bornean and Sumatran orangutans, P. pygmaeus (Linnaeus 1760) and P. abelii (Lesson 1827), as distinct species occurred in 2001 [1, 2]. Here, we show that an isolated population from Batang Toru, at the southernmost range limit of extant Sumatran orangutans south of Lake Toba, is distinct from other northern Sumatran and Bornean populations. By comparing cranio-mandibular and dental characters of an orangutan killed in a human-animal conflict to those of 33 adult male orangutans of a similar developmental stage, we found consistent differences between the Batang Toru individual and other extant Ponginae. Our analyses of 37 orangutan genomes provided a second line of evidence. Model-based approaches revealed that the deepest split in the evolutionary history of extant orangutans occurred ∼3.38 mya between the Batang Toru population and those to the north of Lake Toba, whereas both currently recognized species separated much later, about 674 kya. Our combined analyses support a new classification of orangutans into three extant species. The new species, Pongo tapanuliensis, encompasses the Batang Toru population, of which fewer than 800 individuals survive. VIDEO ABSTRACT.


Asunto(s)
Especiación Genética , Pongo/genética , Animales , Conducta Animal/fisiología , Evolución Biológica , Especies en Peligro de Extinción , Flujo Génico/genética , Variación Genética , Genoma , Genómica , Hominidae/genética , Metagenómica/métodos , Filogenia , Pongo/clasificación , Pongo/fisiología , Pongo abelii/genética , Pongo pygmaeus/genética
15.
Nat Commun ; 8(1): 1462, 2017 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-29133782

RESUMEN

Mechanistic target of rapamycin (mTOR) enhances immunity in addition to orchestrating metabolism. Here we show that mTOR coordinates immunometabolic reconfiguration of marginal zone (MZ) B cells, a pre-activated lymphocyte subset that mounts antibody responses to T-cell-independent antigens through a Toll-like receptor (TLR)-amplified pathway involving transmembrane activator and CAML interactor (TACI). This receptor interacts with mTOR via the TLR adapter MyD88. The resulting mTOR activation instigates MZ B-cell proliferation, immunoglobulin G (IgG) class switching, and plasmablast differentiation through a rapamycin-sensitive pathway that integrates metabolic and antibody-inducing transcription programs, including NF-κB. Disruption of TACI-mTOR interaction by rapamycin, truncation of the MyD88-binding domain of TACI, or B-cell-conditional mTOR deficiency interrupts TACI signaling via NF-κB and cooperation with TLRs, thereby hampering IgG production to T-cell-independent antigens but not B-cell survival. Thus, mTOR drives innate-like antibody responses by linking proximal TACI signaling events with distal immunometabolic transcription programs.


Asunto(s)
Linfocitos B/inmunología , Inmunoglobulina G/inmunología , Diana Mecanicista del Complejo 1 de la Rapamicina/inmunología , Factor 88 de Diferenciación Mieloide/metabolismo , Serina-Treonina Quinasas TOR/inmunología , Proteína Activadora Transmembrana y Interactiva del CAML/inmunología , Animales , Línea Celular , Proliferación Celular , Activación Enzimática , Perfilación de la Expresión Génica , Células HEK293 , Humanos , Cambio de Clase de Inmunoglobulina/genética , Cambio de Clase de Inmunoglobulina/inmunología , Inmunoglobulina G/biosíntesis , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/metabolismo , Transducción de Señal/inmunología , Sirolimus/farmacología
16.
Immunity ; 47(1): 118-134.e8, 2017 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-28709802

RESUMEN

Secretory immunoglobulin A (SIgA) enhances host-microbiota symbiosis, whereas SIgM remains poorly understood. We found that gut IgM+ plasma cells (PCs) were more abundant in humans than mice and clonally related to a large repertoire of memory IgM+ B cells disseminated throughout the intestine but rare in systemic lymphoid organs. In addition to sharing a gut-specific gene signature with memory IgA+ B cells, memory IgM+ B cells were related to some IgA+ clonotypes and switched to IgA in response to T cell-independent or T cell-dependent signals. These signals induced abundant IgM which, together with SIgM from clonally affiliated PCs, recognized mucus-embedded commensals. Bacteria recognized by human SIgM were dually coated by SIgA and showed increased richness and diversity compared to IgA-only-coated or uncoated bacteria. Thus, SIgM may emerge from pre-existing memory rather than newly activated naive IgM+ B cells and could help SIgA to anchor highly diverse commensal communities to mucus.


Asunto(s)
Angiodisplasia/inmunología , Linfocitos B/inmunología , Neoplasias del Colon/inmunología , Pólipos del Colon/inmunología , Inmunoglobulina M/metabolismo , Intestinos/inmunología , Células Plasmáticas/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Células Clonales , Femenino , Microbioma Gastrointestinal/inmunología , Humanos , Inmunidad Mucosa , Inmunoglobulina A/metabolismo , Cambio de Clase de Inmunoglobulina , Memoria Inmunológica , Intestinos/microbiología , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Simbiosis
17.
Mol Biol Evol ; 33(12): 3268-3283, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27795229

RESUMEN

Natural selection is crucial for the adaptation of populations to their environments. Here, we present the first global study of natural selection in the Hominidae (humans and great apes) based on genome-wide information from population samples representing all extant species (including most subspecies). Combining several neutrality tests we create a multi-species map of signatures of natural selection covering all major types of natural selection. We find that the estimated efficiency of both purifying and positive selection varies between species and is significantly correlated with their long-term effective population size. Thus, even the modest differences in population size among the closely related Hominidae lineages have resulted in differences in their ability to remove deleterious alleles and to adapt to changing environments. Most signatures of balancing and positive selection are species-specific, with signatures of balancing selection more often being shared among species. We also identify loci with evidence of positive selection across several lineages. Notably, we detect signatures of positive selection in several genes related to brain function, anatomy, diet and immune processes. Our results contribute to a better understanding of human evolution by putting the evidence of natural selection in humans within its larger evolutionary context. The global map of natural selection in our closest living relatives is available as an interactive browser at http://tinyurl.com/nf8qmzh.


Asunto(s)
Hominidae/genética , Selección Genética , Alelos , Animales , Evolución Biológica , Bases de Datos de Ácidos Nucleicos , Evolución Molecular , Estudios de Asociación Genética , Variación Genética , Humanos/genética , Metagenómica/métodos , Polimorfismo Genético , Análisis de Secuencia de ADN/métodos
18.
Nat Genet ; 48(9): 1066-70, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27455350

RESUMEN

To shed light on the peopling of South Asia and the origins of the morphological adaptations found there, we analyzed whole-genome sequences from 10 Andamanese individuals and compared them with sequences for 60 individuals from mainland Indian populations with different ethnic histories and with publicly available data from other populations. We show that all Asian and Pacific populations share a single origin and expansion out of Africa, contradicting an earlier proposal of two independent waves of migration. We also show that populations from South and Southeast Asia harbor a small proportion of ancestry from an unknown extinct hominin, and this ancestry is absent from Europeans and East Asians. The footprints of adaptive selection in the genomes of the Andamanese show that the characteristic distinctive phenotypes of this population (including very short stature) do not reflect an ancient African origin but instead result from strong natural selection on genes related to human body size.


Asunto(s)
Adaptación Fisiológica/genética , Pueblo Asiatico/genética , Marcadores Genéticos/genética , Variación Genética/genética , Genética de Población , Migración Humana , Selección Genética/genética , Asia , Estudio de Asociación del Genoma Completo , Humanos , Fenotipo
19.
Bioinformatics ; 31(24): 3946-52, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26315912

RESUMEN

MOTIVATION: Detecting positive selection in genomic regions is a recurrent topic in natural population genetic studies. However, there is little consistency among the regions detected in several genome-wide scans using different tests and/or populations. Furthermore, few methods address the challenge of classifying selective events according to specific features such as age, intensity or state (completeness). RESULTS: We have developed a machine-learning classification framework that exploits the combined ability of some selection tests to uncover different polymorphism features expected under the hard sweep model, while controlling for population-specific demography. As a result, we achieve high sensitivity toward hard selective sweeps while adding insights about their completeness (whether a selected variant is fixed or not) and age of onset. Our method also determines the relevance of the individual methods implemented so far to detect positive selection under specific selective scenarios. We calibrated and applied the method to three reference human populations from The 1000 Genome Project to generate a genome-wide classification map of hard selective sweeps. This study improves detection of selective sweep by overcoming the classical selection versus no-selection classification strategy, and offers an explanation to the lack of consistency observed among selection tests when applied to real data. Very few signals were observed in the African population studied, while our method presents higher sensitivity in this population demography. AVAILABILITY AND IMPLEMENTATION: The genome-wide results for three human populations from The 1000 Genomes Project and an R-package implementing the 'Hierarchical Boosting' framework are available at http://hsb.upf.edu/.


Asunto(s)
Genética de Población/métodos , Genómica/métodos , Aprendizaje Automático , Demografía , Humanos , Polimorfismo Genético , Selección Genética
20.
Genome Biol Evol ; 7(4): 1141-54, 2015 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-25840415

RESUMEN

Genes vary in their likelihood to undergo adaptive evolution. The genomic factors that determine adaptability, however, remain poorly understood. Genes function in the context of molecular networks, with some occupying more important positions than others and thus being likely to be under stronger selective pressures. However, how positive selection distributes across the different parts of molecular networks is still not fully understood. Here, we inferred positive selection using comparative genomics and population genetics approaches through the comparison of 10 mammalian and 270 human genomes, respectively. In agreement with previous results, we found that genes with lower network centralities are more likely to evolve under positive selection (as inferred from divergence data). Surprisingly, polymorphism data yield results in the opposite direction than divergence data: Genes with higher centralities are more likely to have been targeted by recent positive selection during recent human evolution. Our results indicate that the relationship between centrality and the impact of adaptive evolution highly depends on the mode of positive selection and/or the evolutionary time-scale.


Asunto(s)
Evolución Molecular , Proteínas/genética , Selección Genética , Animales , Genes , Genes Esenciales , Genoma Humano , Humanos , Polimorfismo Genético , Mapeo de Interacción de Proteínas
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