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1.
Front Genet ; 15: 1397156, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38948356

RESUMEN

Introduction: Risk governance is central for the successful and ethical operation of biobanks and the continued social license for being custodians of samples and data. Risks in biobanking are often framed as risks for participants, whereas the biobank's risks are often considered as technical ones. Risk governance relies on identifying, assessing, mitigating and communicating all risks based on technical and standardized procedures. However, within such processes, biobank staff are often involved tangentially. In this study, the aim has been to conduct a risk mapping exercise bringing biobank staff as key actors into the process, making better sense of emerging structure of biobanks. Methods: Based on the qualitative research method of situational analysis as well as the card-based discussion and stakeholder engagement processes, risk mapping was conducted at the biobank setting as an interactive engagement exercise. The analyzed material comprises mainly of moderated group discussions. Results: The findings from the risk mapping activity are framed through an organismic metaphor: the biobank as a growing, living organism in a changing environment, where trust and sustainability are cross-cutting elements in making sense of the risks. Focusing on the situatedness of the dynamics within biobanking activity highlights the importance of prioritizing relations at the core of risk governance and promoting ethicality in the biobanking process by expanding the repertoire of considered risks. Conclusion: With the organismic metaphor, the research brings the diverse group of biobank staff to the central stage for risk governance, highlighting how accounting for such diversity and interdependencies at the biobank setting is a prerequisite for an adaptive risk governance.

2.
Matrix Biol Plus ; 9: 100053, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33718859

RESUMEN

Alport syndrome (AS) is a severe inherited glomerulopathy caused by mutations in the genes encoding the α-chains of type-IV collagen, the most abundant component of the extracellular glomerular basement membrane (GBM). Currently most AS mouse models are knockout models for one of the collagen-IV genes. In contrast, about half of AS patients have missense mutations, with single aminoacid substitutions of glycine being the most common. The only mouse model for AS with a homozygous knockin missense mutation, Col4a3-p.Gly1332Glu, was partly described before by our group. Here, a detailed in-depth description of the same mouse is presented, along with another compound heterozygous mouse that carries the glycine substitution in trans with a knockout allele. Both mice recapitulate essential features of AS, including shorten lifespan by 30-35%, increased proteinuria, increased serum urea and creatinine, pathognomonic alternate GBM thinning and thickening, and podocyte foot process effacement. Notably, glomeruli and tubuli respond differently to mutant collagen-IV protomers, with reduced expression in tubules but apparently normal in glomeruli. However, equally important is the fact that in the glomeruli the mutant α3-chain as well as the normal α4/α5 chains seem to undergo a cleavage at, or near the point of the mutation, possibly by the metalloproteinase MMP-9, producing a 35 kDa C-terminal fragment. These mouse models represent a good tool for better understanding the spectrum of molecular mechanisms governing collagen-IV nephropathies and could be used for pre-clinical studies aimed at better treatments for AS.

3.
PLoS One ; 12(3): e0174274, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28334007

RESUMEN

BACKGROUND: Recent data emphasize that thin basement membrane nephropathy (TBMN) should not be viewed as a form of benign familial hematuria since chronic renal failure (CRF) and even end-stage renal disease (ESRD), is a possible development for a subset of patients on long-term follow-up, through the onset of focal and segmental glomerulosclerosis (FSGS). We hypothesize that genetic modifiers may explain this variability of symptoms. METHODS: We looked in silico for potentially deleterious functional SNPs, using very strict criteria, in all the genes significantly expressed in the slit diaphragm (SD). Two variants were genotyped in a cohort of well-studied adult TBMN patients from 19 Greek-Cypriot families, with a homogeneous genetic background. Patients were categorized as "Severe" or "Mild", based on the presence or not of proteinuria, CRF and ESRD. A larger pooled cohort (HEMATURIA) of 524 patients, including IgA nephropathy patients, was used for verification. Additionally, three large general population cohorts [Framingham Heart Study (FHS), KORAF4 and SAPHIR] were used to investigate if the NEPH3-V353M variant has any renal effect in the general population. RESULTS AND CONCLUSIONS: Genotyping for two high-scored variants in 103 TBMN adult patients with founder mutations who were classified as mildly or severely affected, pointed to an association with variant NEPH3-V353M (filtrin). This promising result prompted testing in the larger pooled cohort (HEMATURIA), indicating an association of the 353M variant with disease severity under the dominant model (p = 3.0x10-3, OR = 6.64 adjusting for gender/age; allelic association: p = 4.2x10-3 adjusting for patients' kinships). Subsequently, genotyping 6,531 subjects of the Framingham Heart Study (FHS) revealed an association of the homozygous 353M/M genotype with microalbuminuria (p = 1.0x10-3). Two further general population cohorts, KORAF4 and SAPHIR confirmed the association, and a meta-analysis of all three cohorts (11,258 individuals) was highly significant (p = 1.3x10-5, OR = 7.46). Functional studies showed that Neph3 homodimerization and Neph3-Nephrin heterodimerization are disturbed by variant 353M. Additionally, 353M was associated with differential activation of the unfolded protein response pathway, when overexpressed in stressed cultured undifferentiated podocyte cells, thus attesting to its functional significance. Genetics and functional studies support a "rare variant-strong effect" role for NEPH3-V353M, by exerting a negative modifier effect on primary glomerular hematuria. Additionally, genetics studies provide evidence for a role in predisposing homozygous subjects of the general population to micro-albuminuria.


Asunto(s)
Albuminuria/genética , Predisposición Genética a la Enfermedad/genética , Hematuria/complicaciones , Inmunoglobulinas/genética , Proteínas de la Membrana/genética , Insuficiencia Renal/genética , Adulto , Femenino , Células HEK293 , Hematuria/genética , Humanos , Immunoblotting , Inmunoglobulinas/fisiología , Inmunoprecipitación , Fallo Renal Crónico/genética , Masculino , Proteínas de la Membrana/fisiología , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genética , Factores de Riesgo
4.
Investig Genet ; 7: 1, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26870315

RESUMEN

BACKGROUND: The archeological record indicates that the permanent settlement of Cyprus began with pioneering agriculturalists circa 11,000 years before present, (ca. 11,000 y BP). Subsequent colonization events followed, some recognized regionally. Here, we assess the Y-chromosome structure of Cyprus in context to regional populations and correlate it to phases of prehistoric colonization. RESULTS: Analysis of haplotypes from 574 samples showed that island-wide substructure was barely significant in a spatial analysis of molecular variance (SAMOVA). However, analyses of molecular variance (AMOVA) of haplogroups using 92 binary markers genotyped in 629 Cypriots revealed that the proportion of variance among the districts was irregularly distributed. Principal component analysis (PCA) revealed potential genetic associations of Greek-Cypriots with neighbor populations. Contrasting haplogroups in the PCA were used as surrogates of parental populations. Admixture analyses suggested that the majority of G2a-P15 and R1b-M269 components were contributed by Anatolia and Levant sources, respectively, while Greece Balkans supplied the majority of E-V13 and J2a-M67. Haplotype-based expansion times were at historical levels suggestive of recent demography. CONCLUSIONS: Analyses of Cypriot haplogroup data are consistent with two stages of prehistoric settlement. E-V13 and E-M34 are widespread, and PCA suggests sourcing them to the Balkans and Levant/Anatolia, respectively. The persistent pre-Greek component is represented by elements of G2-U5(xL30) haplogroups: U5*, PF3147, and L293. J2b-M205 may contribute also to the pre-Greek strata. The majority of R1b-Z2105 lineages occur in both the westernmost and easternmost districts. Distinctively, sub-haplogroup R1b- M589 occurs only in the east. The absence of R1b- M589 lineages in Crete and the Balkans and the presence in Asia Minor are compatible with Late Bronze Age influences from Anatolia rather than from Mycenaean Greeks.

5.
Nephron ; 130(3): 200-12, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26138234

RESUMEN

BACKGROUND/AIMS: A subset of patients who present with proteinuria and are diagnosed with focal segmental glomerulosclerosis (FSGS) have inherited heterozygous COL4A3/A4 mutations and are also diagnosed with thin basement membrane nephropathy (TBMN-OMIM: 141200). Two studies showed that co-inheritance of NPHS2-p.Arg229Gln, a podocin variant, may increase the risk for proteinuria and renal function decline. METHODS: We hypothesized that additional podocin variants may exert a similar effect. We studied genetically a well-characterized Cypriot TBMN patient cohort by re-sequencing the NPHS2 coding region. We also performed functional studies in cell culture experiments, investigating the interaction of podocin variants with itself and with nephrin. RESULTS: Potentially disease-modifying podocin variants were searched for by analyzing NPHS2 in 35 'severe' TBMN patients. One non-synonymous variant, p.Glu237Gln, was detected. Both variants, p.Arg229Gln and p.Glu237Gln, were tested in a larger cohort of 122 TBMN patients, who were categorized as 'mild' or 'severe' based on the presence of microscopic hematuria alone or combined with chronic renal failure and/or proteinuria. Seven 'severe' patients carried either of the 2 variants; none was present in the 'mild' patients (p = 0.05, Pearson χ(2)). The 7 carriers belong in 2 families segregating mutation COL4A3-p.Gly1334Glu. Inheritance of the wild-type (WT) and mutant alleles correlated with the phenotype (combined concordance probability 0.003). Immunofluorescence (IF) experiments after dual co-transfection of WT and mutant podocin suggested altered co-localization of mutant homodimers. IF experiments after co-transfection of WT podocin and nephrin showed normal membrane localization, while both podocin variants interfered with normal trafficking, demonstrating perinuclear staining. Immunoprecipitation experiments showed stronger binding of mutant podocin to WT podocin or nephrin. CONCLUSION: The results support the hypothesis that certain hypomorphic podocin variants may act as adverse genetic modifiers when co-inherited with COL4A3/A4 mutations, thus predisposing to FSGS and severe kidney function decline.


Asunto(s)
Autoantígenos/genética , Colágeno Tipo IV/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Fallo Renal Crónico/genética , Proteínas de la Membrana/genética , Anciano , Alelos , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Membrana Basal Glomerular/patología , Glomeruloesclerosis Focal y Segmentaria/genética , Glomeruloesclerosis Focal y Segmentaria/patología , Heterocigoto , Humanos , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/patología , Masculino , Persona de Mediana Edad , Mutación/genética , Linaje , Proteinuria/epidemiología , Proteinuria/genética , Factores Sexuales
6.
J Am Soc Nephrol ; 25(2): 260-75, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24262798

RESUMEN

Thin-basement-membrane nephropathy (TBMN) and Alport syndrome (AS) are progressive collagen IV nephropathies caused by mutations in COL4A3/A4/A5 genes. These nephropathies invariably present with microscopic hematuria and frequently progress to proteinuria and CKD or ESRD during long-term follow-up. Nonetheless, the exact molecular mechanisms by which these mutations exert their deleterious effects on the glomerulus remain elusive. We hypothesized that defective trafficking of the COL4A3 chain causes a strong intracellular effect on the cell responsible for COL4A3 expression, the podocyte. To this end, we overexpressed normal and mutant COL4A3 chains (G1334E mutation) in human undifferentiated podocytes and tested their effects in various intracellular pathways using a microarray approach. COL4A3 overexpression in the podocyte caused chain retention in the endoplasmic reticulum (ER) that was associated with activation of unfolded protein response (UPR)-related markers of ER stress. Notably, the overexpression of normal or mutant COL4A3 chains differentially activated the UPR pathway. Similar results were observed in a novel knockin mouse carrying the Col4a3-G1332E mutation, which produced a phenotype consistent with AS, and in biopsy specimens from patients with TBMN carrying a heterozygous COL4A3-G1334E mutation. These results suggest that ER stress arising from defective localization of collagen IV chains in human podocytes contributes to the pathogenesis of TBMN and AS through activation of the UPR, a finding that may pave the way for novel therapeutic interventions for a variety of collagenopathies.


Asunto(s)
Colágeno Tipo IV/deficiencia , Estrés del Retículo Endoplásmico/fisiología , Membrana Basal Glomerular/metabolismo , Nefritis Hereditaria/metabolismo , Podocitos/metabolismo , Respuesta de Proteína Desplegada/fisiología , Animales , Autoantígenos/genética , Autoantígenos/fisiología , Biopsia , Células Cultivadas , Colágeno Tipo IV/genética , Colágeno Tipo IV/fisiología , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Chaperón BiP del Retículo Endoplásmico , Perfilación de la Expresión Génica , Técnicas de Sustitución del Gen , Membrana Basal Glomerular/patología , Proteínas de Choque Térmico/biosíntesis , Proteínas de Choque Térmico/genética , Heterocigoto , Humanos , Riñón/metabolismo , Riñón/patología , Ratones , Mutación Missense , Nefritis Hereditaria/genética , Nefritis Hereditaria/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Podocitos/patología , Mutación Puntual , Análisis por Matrices de Proteínas , Transporte de Proteínas , Interferencia de ARN , ARN Interferente Pequeño/farmacología , Proteínas Recombinantes de Fusión , Factores de Transcripción del Factor Regulador X , Factores de Transcripción/metabolismo , Transfección
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