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1.
Genome Res ; 32(3): 488-498, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35031571

RESUMO

Although it is known that the mutation rate varies across the genome, previous estimates were based on averaging across various numbers of positions. Here, we describe a method to measure the origination rates of target mutations at target base positions and apply it to a 6-bp region in the human hemoglobin subunit beta (HBB) gene and to the identical, paralogous hemoglobin subunit delta (HBD) region in sperm cells from both African and European donors. The HBB region of interest (ROI) includes the site of the hemoglobin S (HbS) mutation, which protects against malaria, is common in Africa, and has served as a classic example of adaptation by random mutation and natural selection. We found a significant correspondence between de novo mutation rates and past observations of alleles in carriers, showing that mutation rates vary substantially in a mutation-specific manner that contributes to the site frequency spectrum. We also found that the overall point mutation rate is significantly higher in Africans than in Europeans in the HBB region studied. Finally, the rate of the 20A→T mutation, called the "HbS mutation" when it appears in HBB, is significantly higher than expected from the genome-wide average for this mutation type. Nine instances were observed in the African HBB ROI, where it is of adaptive significance, representing at least three independent originations; no instances were observed elsewhere. Further studies will be needed to examine mutation rates at the single-mutation resolution across these and other loci and organisms and to uncover the molecular mechanisms responsible.


Assuntos
Globinas beta , Talassemia beta , Heterozigoto , Humanos , Mutação , Taxa de Mutação , Globinas beta/genética , Talassemia beta/genética
2.
Curr Opin Nephrol Hypertens ; 33(4): 447-455, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38415700

RESUMO

PURPOSE OF REVIEW: More than a decade ago, apolipoprotein L1 ( APOL1 ) risk alleles designated G1 and G2, were discovered to be causally associated with markedly increased risk for progressive kidney disease in individuals of recent African ancestry. Gratifying progress has been made during the intervening years, extending to the development and clinical testing of genomically precise small molecule therapy accompanied by emergence of RNA medicine platforms and clinical testing within just over a decade. RECENT FINDINGS: Given the plethora of excellent prior review articles, we will focus on new findings regarding unresolved questions relating mechanism of cell injury with mode of inheritance, regulation and modulation of APOL1 activity, modifiers and triggers for APOL1 kidney risk penetrance, the pleiotropic spectrum of APOL1 related disease beyond the kidney - all within the context of relevance to therapeutic advances. SUMMARY: Notwithstanding remaining controversies and uncertainties, promising genomically precise therapies targeted at APOL1 mRNA using antisense oligonucleotides (ASO), inhibitors of APOL1 expression, and small molecules that specifically bind and inhibit APOL1 cation flux are emerging, many already at the clinical trial stage. These therapies hold great promise for mitigating APOL1 kidney injury and possibly other systemic phenotypes as well. A challenge will be to develop guidelines for appropriate use in susceptible individuals who will derive the greatest benefit.


Assuntos
Apolipoproteína L1 , Predisposição Genética para Doença , Humanos , Apolipoproteína L1/genética , Nefropatias/genética , Nefropatias/terapia , Genética Populacional , Animais , Fenótipo , Fatores de Risco , Oligonucleotídeos Antissenso/uso terapêutico , Oligonucleotídeos Antissenso/genética
3.
Am J Kidney Dis ; 83(2): 183-195, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37717846

RESUMO

RATIONALE & OBJECTIVE: Genetic etiologies have been identified among approximately 10% of adults with chronic kidney disease (CKD). However, data are lacking regarding the prevalence of monogenic etiologies especially among members of minority groups. This study characterized the genetic markers among members of an Israeli minority group with end-stage kidney disease (ESKD). STUDY DESIGN: A national-multicenter cross-sectional study of Israeli Druze patients (an Arabic-speaking Near-Eastern transnational population isolate) who are receiving maintenance dialysis for ESKD. All study participants underwent exome sequencing. SETTING & PARTICIPANTS: We recruited 94 adults with ESKD, comprising 97% of the total 97 Druze individuals throughout Israel being treated with dialysis during the study period. PREDICTORS: Demographics and clinical characteristics of kidney disease. OUTCOME: Genetic markers. ANALYTICAL APPROACH: Whole-exome sequencing and the relationship of markers to clinical phenotypes. RESULTS: We identified genetic etiologies in 17 of 94 participants (18%). None had a previous molecular diagnosis. A novel, population-specific, WDR19 homozygous pathogenic variant (p.Cys293Tyr) was the most common genetic finding. Other monogenic etiologies included PKD1, PKD2, type IV collagen mutations, and monogenic forms of noncommunicable diseases. The pre-exome clinical diagnosis corresponded to the final molecular diagnosis in fewer than half of the participants. LIMITATIONS: This study was limited to Druze individuals, so its generalizability may be limited. CONCLUSIONS: Exome sequencing identified a genetic diagnosis in approximately 18% of Druze individuals with ESKD. These results support conducting genetic analyses in minority populations with high rates of CKD and for whom phenotypic disease specificity may be low. PLAIN-LANGUAGE SUMMARY: Chronic kidney disease (CKD) affects many people worldwide and has multiple genetic causes. However, there is limited information on the prevalence of genetic etiologies, especially among minority populations. Our national-multicenter study focused on Israeli Druze patients. Using exome-sequencing, we identified previously undetected genetic causes in nearly 20% of patients, including a new and population-specific WDR19 homozygous pathogenic variant. This mutation has not been previously described; it is extremely rare globally but is common among the Druze, which highlights the importance of studying minority populations with high rates of CKD. Our findings provide insights into the genetic basis of end-stage kidney disease in the Israeli Druze, expand the WDR19 phenotypic spectrum, and emphasize the potential value of genetic testing in such populations.


Assuntos
Falência Renal Crônica , Insuficiência Renal Crônica , Adulto , Humanos , Grupos Minoritários , Israel/epidemiologia , Marcadores Genéticos , Estudos Transversais , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/genética , Falência Renal Crônica/terapia , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/diagnóstico , Minorias Desiguais em Saúde e Populações Vulneráveis
4.
BMC Med Educ ; 24(1): 288, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38486173

RESUMO

BACKGROUND: Medical students can assist in reducing healthcare disparities and promote health equity by engaging with rural communities and gaining insights into their unique healthcare needs. A two-arm student-delivered program was designed and implemented during COVID-19 in a social-geographic peripheral area to assist clinics with complex chronic and/or socially disadvantaged patients and improve preventive behavior in townships through home visits delivering community kits. METHODS: We conducted a pre-post design study which included weekly structured medical student reports and monthly structured telephone interviews with clinic directors and municipal partners. Students completed pre-post program survey on their knowledge, skills, and capabilities to address chronic patients from diverse cultural backgrounds (n = 73). The Wilcoxon-Signed-Rank test for related samples was used to determine differences. RESULTS: Following the program, the knowledge and awareness levels of students about working in the community (P < 0.001) and their knowledge of common chronic diseases were significantly improved (Mean Difference (MD) = 0.31; p < 0.001). The program significantly increased students' interest to integrate into community care alongside a hospital (P = 0.012). Thematic analysis of student reports revealed improved insight into the role of primary care. Clinic directors (90%) were highly satisfied and reported that students became an integral part of the clinics' teams. CONCLUSIONS: Integrating medical students into the community through primary-care clinics and home visits in diverse communities, exposed students to the interwoven effect of clinical and social determinants on health and improve their knowledge of common chronic diseases. Participation in the program encouraged students to consider a career in community care.


Assuntos
Estudantes de Medicina , Humanos , Escolha da Profissão , Promoção da Saúde , Atenção Primária à Saúde , Doença Crônica
5.
J Am Soc Nephrol ; 32(2): 495-501, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33184124

RESUMO

BACKGROUND: Increasing cancer incidence among children alongside improved treatments has resulted in a growing number of pediatric cancer survivors. Despite childhood cancer survivors' exposure to various factors that compromise kidney function, few studies have investigated the association between childhood cancer and future kidney disease. METHODS: To assess the risk of ESKD among childhood cancer survivors, we conducted a nationwide, population-based, retrospective cohort study that encompassed all Israeli adolescents evaluated for mandatory military service from 1967 to 1997. After obtaining detailed histories, we divided the cohort into three groups: participants without a history of tumors, those with a history of a benign tumor (nonmalignant tumor with functional impairment), and those with a history of malignancy (excluding kidney cancer). This database was linked to the Israeli ESKD registry to identify incident ESKD cases. We used Cox proportional hazards models to estimate the hazard ratio (HR) of ESKD. RESULTS: Of the 1,468,600 participants in the cohort, 1,444,345 had no history of tumors, 23,282 had a history of a benign tumor, and 973 had a history of malignancy. During a mean follow-up of 30.3 years, 2416 (0.2%) participants without a history of tumors developed ESKD. Although a history of benign tumors was not associated with an increased ESKD risk, participants with a history of malignancy exhibited a substantially elevated risk for ESKD compared with participants lacking a history of tumors, after controlling for age, sex, enrollment period, and paternal origin (adjusted HR, 3.2; 95% confidence interval, 1.3 to 7.7). CONCLUSIONS: Childhood cancer is associated with an increased risk for ESKD, suggesting the need for tighter and longer nephrological follow-up.


Assuntos
Falência Renal Crônica/epidemiologia , Neoplasias/complicações , Adolescente , Adulto , Criança , Estudos de Coortes , Feminino , Humanos , Incidência , Israel , Falência Renal Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Modelos de Riscos Proporcionais , Fatores de Risco , Adulto Jovem
6.
Am J Physiol Lung Cell Mol Physiol ; 320(3): L422-L429, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33404363

RESUMO

The unique clinical features of COVID-19 disease present a formidable challenge in the understanding of its pathogenesis. Within a very short time, our knowledge regarding basic physiological pathways that participate in SARS-CoV-2 invasion and subsequent organ damage have been dramatically expanded. In particular, we now better understand the complexity of the renin-angiotensin-aldosterone system (RAAS) and the important role of angiotensin converting enzyme (ACE)-2 in viral binding. Furthermore, the critical role of its major product, angiotensin (Ang)-(1-7), in maintaining microcirculatory balance and in the control of activated proinflammatory and procoagulant pathways, generated in this disease, have been largely clarified. The kallikrein-bradykinin (BK) system and chymase are intensively interwoven with RAAS through many pathways with complex reciprocal interactions. Yet, so far, very little attention has been paid to a possible role of these physiological pathways in the pathogenesis of COVID-19 disease, even though BK and chymase exert many physiological changes characteristic to this disorder. Herein, we outline the current knowledge regarding the reciprocal interactions of RAAS, BK, and chymase that are probably turned-on in COVID-19 disease and participate in its clinical features. Interventions affecting these systems, such as the inhibition of chymase or blocking BKB1R/BKB2R, might be explored as potential novel therapeutic strategies in this devastating disorder.


Assuntos
COVID-19/patologia , Quimases/metabolismo , Cininas/metabolismo , Sistema Renina-Angiotensina , SARS-CoV-2/isolamento & purificação , COVID-19/metabolismo , COVID-19/virologia , Humanos
7.
N Engl J Med ; 378(5): 428-438, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29385364

RESUMO

BACKGROUND: The long-term risk associated with childhood kidney disease that had not progressed to chronic kidney disease in childhood is unclear. We aimed to estimate the risk of future end-stage renal disease (ESRD) among adolescents who had normal renal function and a history of childhood kidney disease. METHODS: We conducted a nationwide, population-based, historical cohort study of 1,521,501 Israeli adolescents who were examined before compulsory military service in 1967 through 1997; data were linked to the Israeli ESRD registry. Kidney diseases in childhood included congenital anomalies of the kidney and urinary tract, pyelonephritis, and glomerular disease; all participants included in the primary analysis had normal renal function and no hypertension in adolescence. Cox proportional-hazards models were used to estimate the hazard ratio for ESRD associated with a history of childhood kidney disease. RESULTS: During 30 years of follow-up, ESRD developed in 2490 persons. A history of any childhood kidney disease was associated with a hazard ratio for ESRD of 4.19 (95% confidence interval [CI], 3.52 to 4.99). The associations between each diagnosis of kidney disease in childhood (congenital anomalies of the kidney and urinary tract, pyelonephritis, and glomerular disease) and the risk of ESRD in adulthood were similar in magnitude (multivariable-adjusted hazard ratios of 5.19 [95% CI, 3.41 to 7.90], 4.03 [95% CI, 3.16 to 5.14], and 3.85 [95% CI, 2.77 to 5.36], respectively). A history of kidney disease in childhood was associated with younger age at the onset of ESRD (hazard ratio for ESRD among adults <40 years of age, 10.40 [95% CI, 7.96 to 13.59]). CONCLUSIONS: A history of clinically evident kidney disease in childhood, even if renal function was apparently normal in adolescence, was associated with a significantly increased risk of ESRD, which suggests that kidney injury or structural abnormality in childhood has long-term consequences.


Assuntos
Nefropatias/complicações , Falência Renal Crônica/etiologia , Sistema Urinário/anormalidades , Adolescente , Adulto , Estudos de Coortes , Feminino , Seguimentos , Humanos , Incidência , Israel/epidemiologia , Rim/anormalidades , Falência Renal Crônica/epidemiologia , Tábuas de Vida , Masculino , Pielonefrite/complicações , Sistema de Registros , Risco , Sistema Urinário/cirurgia , Adulto Jovem
8.
Am J Med Genet A ; 185(11): 3390-3400, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34435747

RESUMO

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genodermatosis caused by mutations in the gene coding for type VII collagen (COL7A1). More than 800 different pathogenic mutations in COL7A1 have been described to date; however, the ancestral origins of many of these mutations have not been precisely identified. In this study, 32 RDEB patient samples from the Southwestern United States, Mexico, Chile, and Colombia carrying common mutations in the COL7A1 gene were investigated to determine the origins of these mutations and the extent to which shared ancestry contributes to disease prevalence. The results demonstrate both shared European and American origins of RDEB mutations in distinct populations in the Americas and suggest the influence of Sephardic ancestry in at least some RDEB mutations of European origins. Knowledge of ancestry and relatedness among RDEB patient populations will be crucial for the development of future clinical trials and the advancement of novel therapeutics.


Assuntos
Colágeno Tipo VII/genética , Epidermólise Bolhosa Distrófica/genética , Hispânico ou Latino/genética , Judeus/genética , Chile/epidemiologia , Colômbia/epidemiologia , Epidermólise Bolhosa Distrófica/epidemiologia , Feminino , Genes Recessivos/genética , Humanos , Masculino , México/epidemiologia , Fenótipo , Estados Unidos/epidemiologia
9.
Pediatr Nephrol ; 36(6): 1387-1396, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32500249

RESUMO

Chronic kidney disease (CKD) is a major public health challenge, affecting as much as 8 to 18% of the world population. Identifying childhood risk factors for future CKD may help clinicians make early diagnoses and initiation of preventive interventions for CKD and its attendant comorbidities as well as monitoring for complications. The purpose of this review is to describe childhood risk factors that may predict development of overt kidney disease later in life. Currently, there are multiple childhood risk factors associated with future onset and progression of CKD. These risk factors can be grouped into five categories: genetic factors (e.g., monogenic or risk alleles), perinatal factors (e.g., low birth weight and prematurity), childhood kidney diseases (e.g., congenital anomalies, glomerular diseases, and renal cystic ciliopathies), childhood onset of chronic conditions (e.g., cancer, diabetes, hypertension, dyslipidemia, and obesity), and different lifestyle factors (e.g., physical activity, diet, and factors related to socioeconomic status). The available published information suggests that the lifelong risk for CKD can be attributed to multiple factors that appear already during childhood. However, results are conflicting on the effects of childhood physical activity, diet, and dyslipidemia on future renal function. On the other hand, there is consistent evidence to support follow-up of high-risk groups.


Assuntos
Insuficiência Renal Crônica , Adulto , Criança , Progressão da Doença , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/etiologia , Fatores de Risco , Classe Social
10.
Pediatr Nephrol ; 36(2): 333-340, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32761484

RESUMO

BACKGROUND: Diabetic kidney disease (DKD) is becoming increasingly common among children. We aimed to estimate the risk of end-stage renal disease (ESKD) and mortality among adolescents with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) and normal renal function compared with non-diabetics. We hypothesized that childhood onset T1DM vs. T2DM would be associated with a different risk profile for developing ESKD and its complications. METHODS: A nationwide, population-based, retrospective cohort study, including 1,500,522 adolescents examined for military service between 1967 and 1997, which were classified according to the presence and type of diabetes. Data were linked to the Israeli ESKD registry. Cox proportional-hazards models were used to estimate the hazard ratio (HR) for ESKD. RESULTS: At study enrolment, 1183 adolescents had T1DM and 196 had T2DM. ESKD developed in 2386 non-diabetic individuals (0.2%) compared with 72 individuals (6.1%) with T1DM and 8 individuals (4.1%) with T2DM. Participants with T1DM were younger at ESKD onset than participants with T2DM (median age, 36.0 vs. 40.5 years, P < 0.05). In a multivariate model adjusted for age, sex, paternal origin, enrollment year, BMI, and blood pressure, T1DM and T2DM were associated with HR of 36.4 (95% CI 28.3-46.9) and 19.3 (95% CI 9.6-38.8) for ESKD, respectively. Stratification according to sex, ethnicity, immigration, and socioeconomic status did not materially change the HR. During the follow-up period, mortality rates were higher in T2DM as compared with T1DM and controls (8.7 %, 2.2%, and 2.7% respectively). CONCLUSIONS: T1DM and T2DM in adolescents with normal renal function confer a significantly increased risk for ESKD. T1DM is associated with younger age at ESKD onset while T2DM is associated with higher mortality rate.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Falência Renal Crônica , Adolescente , Adulto , Criança , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/etiologia , Humanos , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/etiologia , Estudos Retrospectivos , Fatores de Risco
11.
Am J Physiol Endocrinol Metab ; 318(6): E878-E880, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421367

RESUMO

The viral pandemic of the coronavirus disease 2019 (COVID-19), generated by a novel mutated severe acute respiratory syndrome coronavirus (SARS-CoV-2), has become a serious worldwide public health emergency, evolving exponentially. While the main organ targeted in this disease is the lungs, other vital organs, such as the heart and kidney, may be implicated. The main host receptor of the SARS-CoV-2 is angiotensin converting enzyme 2 (ACE2), a major component of the renin-angiotensin-aldosterone system (RAAS). The ACE2 is also involved in testicular male regulation of steroidogenesis and spermatogenesis. As the SARS-CoV-2 may have the potential to infect the testis via ACE2 and adversely affect male reproductive system, it is essential to commence with targeted studies to learn from the current pandemic, with the possibility of preemptive intervention, depending on the findings and time course of the continuing pandemic.


Assuntos
Infecções por Coronavirus/complicações , Infertilidade Masculina/virologia , Peptidil Dipeptidase A/fisiologia , Pneumonia Viral/complicações , Enzima de Conversão de Angiotensina 2 , Betacoronavirus , COVID-19 , Humanos , Masculino , Pandemias , Receptores Virais/fisiologia , Sistema Renina-Angiotensina , SARS-CoV-2 , Espermatogênese , Testículo/fisiopatologia , Testículo/virologia
13.
Stem Cells ; 37(2): 176-189, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30379370

RESUMO

The interactions of cancer stem cells (CSCs) within the tumor microenvironment (TME), contribute to the overall phenomenon of intratumoral heterogeneity, which also involve CSC interactions with noncancer stromal cells. Comprehensive understanding of the tumorigenesis process requires elucidating the coordinated gene expression between cancer and tumor stromal cells for each tumor. We show that human gastric cancer cells (GSC1) subvert gene expression and cytokine production by mesenchymal stem cells (GSC-MSC), thus promoting tumor progression. Using mixed composition of human tumor xenografts, organotypic culture, and in vitro assays, we demonstrate GSC1-mediated specific reprogramming of "naïve" MSC into specialized tumor associated MSC equipped with a tumor-promoting phenotype. Although paracrine effect of GSC-MSC or primed-MSC is sufficient to enable 2D growth of GSC1, cell-cell interaction with GSC-MSC is necessary for 3D growth and in vivo tumor formation. At both the transcriptional and at the protein level, RNA-Seq and proteome analyses, respectively, revealed increased R-spondin expression in primed-MSC, and paracrine and juxtacrine mediated elevation of Lgr5 expression in GSC1, suggesting GSC-MSC-mediated support of cancer stemness in GSC1. CSC properties are sustained in vivo through the interplay between GSC1 and GSC-MSC, activating the R-spondin/Lgr5 axis and WNT/ß-catenin signaling pathway. ß-Catenin+ cell clusters show ß-catenin nuclear localization, indicating the activation of the WNT/ß-catenin signaling pathway in these cells. The ß-catenin+ cluster of cells overlap the Lgr5+ cells, however, not all Lgr5+ cells express ß-catenin. A predominant means to sustain the CSC contribution to tumor progression appears to be subversion of MSC in the TME by cancer cells. Stem Cells 2018 Stem Cells 2019;37:176-189.


Assuntos
Reprogramação Celular/genética , Células-Tronco Mesenquimais/metabolismo , Neoplasias Gástricas/genética , Humanos , Neoplasias Gástricas/metabolismo , Microambiente Tumoral
14.
Am J Physiol Cell Physiol ; 317(2): C209-C225, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31116585

RESUMO

We hypothesized that a functional apolipoprotein LI (APOL1)-miR193a axis (inverse relationship) preserves, but disruption alters, the podocyte molecular phenotype through the modulation of autophagy flux. Podocyte-expressing APOL1G0 (G0-podocytes) showed downregulation but podocyte-expressing APOL1G1 (G1-podocytes) and APOL1G2 (G2-podocytes) displayed enhanced miR193a expression. G0-, G1-, and G2-podocytes showed enhanced expression of light chain (LC) 3-II and beclin-1, but a disparate expression of p62 (low in wild-type but high in risk alleles). G0-podocytes showed enhanced, whereas G1- and G2-podocytes displayed decreased, phosphorylation of Unc-51-like autophagy-activating kinase (ULK)1 and class III phosphatidylinositol 3-kinase (PI3KC3). Podocytes overexpressing miR193a (miR193a-podocytes), G1, and G2 showed decreased transcription of PIK3R3 (PI3KC3's regulatory unit). Since 3-methyladenine (3-MA) enhanced miR193a expression but inhibited PIK3R3 transcription, it appears that 3-MA inhibits autophagy and induces podocyte dedifferentiation via miR193a generation. miR193a-, G1-, and G2-podocytes also showed decreased phosphorylation of mammalian target of rapamycin (mTOR) that could repress lysosome reformation. G1- and G2-podocytes showed enhanced expression of run domain beclin-1-interacting and cysteine-rich domain-containing protein (Rubicon); however, its silencing prevented their dedifferentiation. Docking, protein-protein interaction, and immunoprecipitation studies with antiautophagy-related gene (ATG)14L, anti-UV radiation resistance-associated gene (UVRAG), or Rubicon antibodies suggested the formation of ATG14L complex I and UVRAG complex II in G0-podocytes and the formation of Rubicon complex III in G1- and G2-podocytes. These findings suggest that the APOL1 risk alleles favor podocyte dedifferentiation through blockade of multiple autophagy pathways.


Assuntos
Apolipoproteína L1/metabolismo , Autofagia , Desdiferenciação Celular , MicroRNAs/metabolismo , Podócitos/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Apolipoproteína L1/genética , Autofagossomos/metabolismo , Autofagossomos/patologia , Proteínas Relacionadas à Autofagia/metabolismo , Linhagem Celular Transformada , Regulação da Expressão Gênica , Humanos , MicroRNAs/genética , Simulação de Dinâmica Molecular , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Podócitos/patologia , Mapas de Interação de Proteínas , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo
15.
Am J Pathol ; 188(11): 2508-2528, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30201495

RESUMO

Human parietal epithelial cells (PECs) are progenitor cells that sustain podocyte homeostasis. We hypothesized that the lack of apolipoprotein (APO) L1 ensures the PEC phenotype, but its induction initiates PEC transition (expression of podocyte markers). APOL1 expression and down-regulation of miR193a coincided with the expression of podocyte markers during the transition. The induction of APOL1 also stimulated transition markers in human embryonic kidney cells (cells with undetectable APOL1 protein expression). APOL1 silencing in PECs up-regulated miR193a expression, suggesting the possibility of a reciprocal feedback relationship between APOL1 and miR193a. HIV, interferon-γ, and vitamin D receptor agonist down-regulated miR193a expression and induced APOL1 expression along with transition markers in PECs. Luciferase assay suggested a putative interaction between miR193a and APOL1. Since silencing of APOL1 attenuated HIV-, vitamin D receptor agonist-, miR193a inhibitor-, and interferon-γ-induced expression of transition markers, APOL1 appears to be a critical functional constituent of the miR193a- APOL1 axis in PECs. This notion was confirmed by further enhanced expression of PEC markers in APOL1 mRNA-silenced PECs. In vivo studies, glomeruli in patients with HIV, and HIV/APOL1 transgenic mice had foci of PECs expressing synaptopodin, a transition marker. APOL1 likely regulates PEC molecular phenotype through modulation of miR193a expression, and APOL1 and miR193a share a reciprocal feedback relationship.


Assuntos
Nefropatia Associada a AIDS/patologia , Apolipoproteína L1/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica , Glomérulos Renais/patologia , MicroRNAs/genética , Nefropatia Associada a AIDS/metabolismo , Nefropatia Associada a AIDS/virologia , Animais , Apolipoproteína L1/genética , Estudos de Casos e Controles , Células Epiteliais/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Glomérulos Renais/metabolismo , Camundongos , Camundongos Transgênicos
16.
Curr Opin Nephrol Hypertens ; 28(1): 77-86, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30431460

RESUMO

PURPOSE OF REVIEW: The purpose of this mini-review is to highlight some unresolved questions and controversies in the evolving story of apolipoprotein L1 (APOL1) nephropathy. RECENT FINDINGS: We highlight studies that introduce complexity in unraveling the mechanisms whereby APOL1 risk variant alleles cause disease. These include studies which support a possible protective role for the APOL1 GO nonrisk ancestral allele, and studies which explore the initiating events that may trigger other downstream pathways mediating APOL1 cellular injury. We also review studies that reconcile the perplexing findings regarding APOL1 anionic or cationic conductance, and pH dependency, and also studies that attempt to characterize the 3-dimensional structure of APOL1 C-terminal in APOL1 variants, as well as that of the serum resistance-associated protein. We also attempt to convey new insights from in-vivo and in-vitro models, including studies that do not support the differential toxicity of APOL1 renal risk variants and recapitulate the clinical variability of individuals at genotypic risk. SUMMARY: Along with major progress that had been achieved in the field of APOL1 nephropathy, controversies and enigmatic issues persist. It remains to be determined which of the pathways which have been demonstrated to mediate cell injury by ectopically expressed APOL1 risk variants in cellular and organismal models are relevant to human disease and can pave the way to potential therapy.


Assuntos
Apolipoproteína L1/genética , Nefropatias/etiologia , Animais , Doenças Cardiovasculares/etiologia , Nefropatias Diabéticas/etiologia , Genótipo , Humanos , Concentração de Íons de Hidrogênio , Nefropatias/genética , Camundongos
17.
Am J Physiol Renal Physiol ; 314(5): F832-F843, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29357419

RESUMO

The loss of podocyte (PD) molecular phenotype is an important feature of diabetic podocytopathy. We hypothesized that high glucose (HG) induces dedifferentiation in differentiated podocytes (DPDs) through alterations in the apolipoprotein (APO) L1-microRNA (miR) 193a axis. HG-induced DPD dedifferentiation manifested in the form of downregulation of Wilms' tumor 1 (WT1) and upregulation of paired box 2 (PAX2) expression. WT1-silenced DPDs displayed enhanced expression of PAX2. Immunoprecipitation of DPD cellular lysates with anti-WT1 antibody revealed formation of WT1 repressor complexes containing Polycomb group proteins, enhancer of zeste homolog 2, menin, and DNA methyltransferase (DNMT1), whereas silencing of either WT1 or DNMT1 disrupted this complex with enhanced expression of PAX2. HG-induced DPD dedifferentiation was associated with a higher expression of miR193a, whereas inhibition of miR193a prevented DPD dedifferentiation in HG milieu. HG downregulated DPD expression of APOL1. miR193a-overexpressing DPDs displayed downregulation of APOL1 and enhanced expression of dedifferentiating markers; conversely, silencing of miR193a enhanced the expression of APOL1 and preserved DPD phenotype. Moreover, stably APOL1G0-overexpressing DPDs displayed the enhanced expression of WT1 but attenuated expression of miR193a; nonetheless, silencing of APOL1 reversed these effects. Since silencing of APOL1 enhanced miR193a expression as well as dedifferentiation in DPDs, it appears that downregulation of APOL1 contributed to dedifferentiation of DPDs through enhanced miR193a expression in HG milieu. Vitamin D receptor agonist downregulated miR193a, upregulated APOL1 expression, and prevented dedifferentiation of DPDs in HG milieu. These findings suggest that modulation of the APOL1-miR193a axis carries a potential to preserve DPD molecular phenotype in HG milieu.


Assuntos
Apolipoproteína L1/metabolismo , Desdiferenciação Celular/efeitos dos fármacos , Glucose/toxicidade , MicroRNAs/metabolismo , Podócitos/efeitos dos fármacos , Apolipoproteína L1/genética , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Linhagem Celular Transformada , DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , MicroRNAs/genética , Fator de Transcrição PAX2/genética , Fator de Transcrição PAX2/metabolismo , Fenótipo , Podócitos/metabolismo , Podócitos/patologia , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Receptores de Calcitriol/agonistas , Receptores de Calcitriol/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas WT1/genética , Proteínas WT1/metabolismo
18.
Kidney Int ; 93(6): 1270-1272, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29792270

RESUMO

Only some individuals carrying the high-risk APOL1 genotype go on to develop kidney disease phenotypes. In this issue of Kidney International, Nadkarni and colleagues report the associations of several biomarkers with renal outcomes in individuals with high-risk APOL1 genotypes. In the era of precision medicine, these findings should translate into improved longitudinal risk assessment for this high-risk population and might also provide additional insights regarding sites and mechanisms of APOL1 nephropathy.


Assuntos
Apolipoproteínas/genética , Lipoproteínas HDL/genética , Negro ou Afro-Americano , Apolipoproteína L1 , Predisposição Genética para Doença , Genótipo , Humanos , Fatores de Risco
19.
Lancet ; 389(10088): 2551-2562, 2017 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-28495106

RESUMO

The principle that global human identity and dignity supersede other values is a broadly accepted conviction that guides practice and policies in the realm of human health in most of the world. An assessment of the level of success that Israel has achieved in health, in the face of formidable challenges, including rapid population growth, diverse and often divided ethnic affiliations, and existential security threats, leads us to propose that extension of this principle of global human identity and dignity, together with the objective of a decent society, as overriding values beyond health to other domains of human endeavour within Israel and in its relations with neighbouring peoples, represents an entirely achievable imperative. The result will be to further advance Israel's aspiration to serve as a model for societal decency with wide international acceptance and engagement. We have identified several determinants of Israel's advancement in health, including: articulation of a clear vision, national purpose, and long-term commitment that seeks to take the health of its citizens seriously; a multi-ethnic population that brings diversity and energy to national progress; a political democracy, which is characterised by robust debate and discussion about the nation's future; national legislation governing cardinal health-care processes; cultural and religious histories that respect and revere scholarship, learning, research, and charitable donation; an expanding economy, with recent but increasing appreciation of the economic, social, and political underpinnings of health and health inequalities; a strong base of international support from the Diaspora Jewish community; and a strong desire for acceptance by the international community in key arenas, especially science and health. As a result, despite the fewer than seven decades since its establishment, Israel has achieved important milestones in health. Nevertheless, this trajectory of achievement is threatened by several serious challenges, including the capacity to sustain high-quality universal health coverage, especially for an ageing population living with multiple comorbidities in the face of a stagnant level of the percentage of treasury funding to health care at a level that is well below the average of the Organisation for Economic Co-operation and Development; ever-increasing transfer of services and care covered by the mandatory public health services basket to private programmes; insufficient progress in resolving health disparities among and between communities, populations, and regions of the country congruent with disparities in income and employment; gender inequities; a looming increase in the already alarming shortfall in health-care professionals; and failure to match inpatient and acute care facilities to manage growing needs. These challenges within Israel are magnified in the context of health disparities with the neighbouring Palestinian population, a situation in which ongoing-but fragile and limited-health cooperation and training arrangements cannot stand in for a solution that will address Palestinian national aspirations. We come away from this Series with a great sense of optimism, but with specific recommendations that are based on the foregoing challenges. We believe that by increasing the investment in the health sector, which includes investing in the societal, political, educational, and environmental underpinnings of health, far more can be achieved to move Israel to a model international leadership position in health care, education, and research, and turn health into an engine for economic wellbeing and development. Religious leadership in Israel, with its formidable political influence, can be harnessed to promote health initiatives in areas ranging from smoking cessation and healthy diet to organ transplantation, and most of all condemnation of hostility and its replacement by peaceful resolution of even the deepest conflicts. Most of all, this Series showed that there is an enormous opportunity, which Israel can lead, to leverage the universally accepted principles of health as a sanctuary against conflict and inequity, to achieve a brighter future for a deeply troubled region of the world.


Assuntos
Atenção à Saúde/tendências , Conservação dos Recursos Naturais/tendências , Política de Saúde/tendências , Nível de Saúde , Humanos , Cooperação Internacional , Israel , Crescimento Demográfico
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