RESUMO
BACKGROUND: Mismatch repair (MMR) system is evolutionarily conserved for genome stability maintenance. Germline pathogenic variants (PVs) in MMR genes that lead to MMR functional deficiency are associated with high cancer risk. Knowing the evolutionary origin of germline PVs in human MMR genes will facilitate understanding the biological base of MMR deficiency in cancer. However, systematic knowledge is lacking to address the issue. In this study, we performed a comprehensive analysis to know the evolutionary origin of human MMR PVs. METHODS: We retrieved MMR gene variants from the ClinVar database. The genomes of 100 vertebrates were collected from the UCSC genome browser and ancient human sequencing data were obtained through comprehensive data mining. Cross-species conservation analysis was performed based on the phylogenetic relationship among 100 vertebrates. Rescaled ancient sequencing data were used to perform variant calling for archeological analysis. RESULTS: Using the phylogenetic approach, we traced the 3369 MMR PVs identified in modern humans in 99 non-human vertebrate genomes but found no evidence for cross-species conservation as the source for human MMR PVs. Using the archeological approach, we searched the human MMR PVs in over 5000 ancient human genomes dated from 45,045 to 100 years before present and identified a group of MMR PVs shared between modern and ancient humans mostly within 10,000 years with similar quantitative patterns. CONCLUSION: Our study reveals that MMR PVs in modern humans were arisen within the recent human evolutionary history.
Assuntos
Neoplasias Encefálicas , Neoplasias Colorretais , Reparo de Erro de Pareamento de DNA , Síndromes Neoplásicas Hereditárias , Humanos , Reparo de Erro de Pareamento de DNA/genética , Filogenia , Mutação em Linhagem Germinativa/genética , Células GerminativasRESUMO
BACKGROUND: Genome stability is maintained by the DNA damage repair (DDR) system composed of multiple DNA repair pathways of hundreds of genes. Germline pathogenic variation (PV) in DDR genes damages function of the affected DDR genes, leading to genome instability and high risk of diseases, in particular, cancer. Knowing evolutionary origin of the PVs in human DDR genes is essential to understand the etiology of human diseases. However, answer to the issue remains largely elusive. In this study, we analyzed evolutionary origin for the PVs in human DDR genes. METHODS: We identified 169 DDR genes by referring to various databases and identified PVs in the DDR genes of modern humans from ClinVar database. We performed a phylogenetic analysis to analyze the conservation of human DDR PVs in 100 vertebrates through cross-species genomic data comparison using the phyloFit program of the PHAST package and visualized the results using the GraphPad Prism software and the ggplot module. We identified DDR PVs from over 5000 ancient humans developed a database to host the DDR PVs ( https://genemutation.fhs.um.edu.mo/dbDDR-AncientHumans ). Using the PV data, we performed a molecular archeological analysis to compare the DDR PVs between modern humans and ancient humans. We analyzed evolution selection of DDR genes across 20 vertebrates using the CodeML in PAML for phylogenetic analysis. RESULTS: Our phylogenic analysis ruled out cross-species conservation as the origin of human DDR PVs. Our archeological approach identified rich DDR PVs shared between modern and ancient humans, which were mostly dated within the last 5000 years. We also observed similar pattern of quantitative PV distribution between modern and ancient humans. We further detected a set of ATM, BRCA2 and CHEK2 PVs shared between human and Neanderthals. CONCLUSIONS: Our study reveals that human DDR PVs mostly arose in recent human history. We propose that human high cancer risk caused by DDR PVs can be a by-product of human evolution.
Assuntos
Reparo do DNA , Neoplasias , Humanos , Filogenia , Reparo do DNA/genética , Genes BRCA2 , Neoplasias/genética , Instabilidade Genômica , Dano ao DNA/genética , Predisposição Genética para DoençaRESUMO
Pathogenic variation in BRCA1 and BRCA2 (BRCA) causes high risk of breast and ovarian cancer, and BRCA variation data are important markers for BRCA-related clinical cancer applications. However, comprehensive BRCA variation data are lacking from the Asian population despite its large population size, heterogenous genetic background and diversified living environment across the Asia continent. We performed a systematic study on BRCA variation in Asian population including extensive data mining, standardization, annotation and characterization. We identified 7587 BRCA variants from 685 592 Asian individuals in 40 Asia countries and regions, including 1762 clinically actionable pathogenic variants and 4915 functionally unknown variants (https://genemutation.fhs.um.edu.mo/Asian-BRCA/). We observed the highly ethnic-specific nature of Asian BRCA variants between Asian and non-Asian populations and within Asian populations, highlighting that the current European descendant population-based BRCA data is inadequate to reflect BRCA variation in the Asian population. We also provided archeological evidence for the evolutionary origin and arising time of Asian BRCA variation. We further provided structural-based evidence for the deleterious variants enriched within the functionally unknown Asian BRCA variants. The data from our study provide a current view of BRCA variation in the Asian population and a rich resource to guide clinical applications of BRCA-related cancer for the Asian population.
Assuntos
Neoplasias da Mama , Neoplasias Ovarianas , Feminino , Humanos , Ásia/epidemiologia , Asiático , Povo Asiático/genética , Proteína BRCA1/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Neoplasias Ovarianas/genéticaRESUMO
Gestational diabetes mellitus (GDM) increases risk of adverse pregnancy outcomes and maternal cardiovascular complications. It is widely believed that maternal endothelial dysfunction is a critical determinant of these risks, however, connections to maternal cardiac dysfunction and mechanisms of pathogenesis are unclear. Circulating extracellular vesicles (EVs) are emerging biomarkers that may provide insights into the pathogenesis of GDM. We examined the impact of GDM on maternal cardiac and vascular health in a rat model of diet-induced obesity-associated GDM. We observed a >3-fold increase in circulating levels of endothelial EVs (p < 0.01) and von Willebrand factor (p < 0.001) in GDM rats. A significant increase in mitochondrial DNA (mtDNA) within circulating extracellular vesicles was also observed suggesting possible mitochondrial dysfunction in the vasculature. This was supported by nicotinamide adenine dinucleotide deficiency in aortas of GDM mice. GDM was also associated with cardiac remodeling (increased LV mass) and a marked impairment in maternal diastolic function (increased isovolumetric relaxation time [IVRT], p < 0.01). Finally, we observed a strong positive correlation between endothelial EV levels and IVRT (r = 0.57, p < 0.05). In summary, we observed maternal vascular and cardiac dysfunction in rodent GDM accompanied by increased circulating endothelial EVs and EV-associated mitochondrial DNA. Our study highlights a novel method for assessment of vascular injury in GDM and highlights vascular mitochondrial injury as a possible therapeutic target.
Assuntos
Diabetes Gestacional , Vesículas Extracelulares , Cardiopatias , Animais , DNA Mitocondrial/genética , Diabetes Gestacional/genética , Feminino , Humanos , Camundongos , Gravidez , Ratos , Roedores/genéticaRESUMO
Prostaglandin E2 receptor EP1 (PGE2/EP1) promotes diabetic renal injury, and EP1 receptor deletion improves hyperfiltration, albuminuria, and fibrosis. The role of EP1 receptors in hypertensive kidney disease (HKD) remains controversial. We examined the contribution of EP1 receptors to HKD. EP1 null (EP1-/-) mice were bred with hypertensive TTRhRen mice (Htn) to evaluate kidney function and injury at 24 weeks. EP1 deletion had no effect on elevation of systolic blood pressure in Htn mice (HtnEP1-/-) but resulted in pronounced albuminuria and reduced FITC-inulin clearance, compared with Htn or wild-type (WT) mice. Ultrastructural injury to podocytes and glomerular endothelium was prominent in HtnEP1-/- mice; including widened subendothelial space, subendothelial lucent zones and focal lifting of endothelium from basement membrane, with focal subendothelial cell debris. Cortex COX2 mRNA was increased by EP1 deletion. Glomerular EP3 mRNA was reduced by EP1 deletion, and EP4 by Htn and EP1 deletion. In WT mice, PGE2 increased chloride reabsorption via EP1 in isolated perfused thick ascending limb (TAL), but PGE2 or EP1 deletion did not affect vasopressin-mediated chloride reabsorption. In WT and Htn mouse inner medullary collecting duct (IMCD), PGE2 inhibited vasopressin-water transport, but not in EP1-/- or HtnEP1-/- mice. Overall, EP1 mediated TAL and IMCD transport in response to PGE2 is unaltered in Htn, and EP1 is protective in HKD.
Assuntos
Hipertensão Renal , Podócitos , Receptores de Prostaglandina E Subtipo EP1 , Animais , Modelos Animais de Doenças , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Deleção de Genes , Taxa de Filtração Glomerular/genética , Hipertensão Renal/metabolismo , Hipertensão Renal/patologia , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Masculino , Camundongos , Camundongos Transgênicos , Podócitos/citologia , Podócitos/metabolismo , Podócitos/patologia , Receptores de Prostaglandina E Subtipo EP1/genética , Receptores de Prostaglandina E Subtipo EP1/metabolismoRESUMO
BACKGROUND: Although hemodialysis is a highly effective treatment for diffusive clearance of low molecular weight uremic toxins, its effect on circulating extracellular vesicles and submicron particles is less clear. The purpose of this study was to examine the impact of hemodialysis on circulating levels of submicron particles. METHODS: Plasma samples from patients were collected immediately before and after the mid-week hemodialysis session. Total submicron particles were assessed by nanoparticle tracking analysis and levels of endothelial (CD144+), platelet (CD41+), leukocyte (CD45+), and total (Annexin V+) membrane microparticles (MPs) were assessed by flow cytometry. RESULTS: Total submicron particle number was significantly lower post-dialysis with reductions in particles < 40 nm, 40-100 nm, and 100-1000 nm in size. Circulating annexin V+ MPs, platelet MPs, leukocyte MPs, and endothelial MPs were all reduced following dialysis. Assessment of protein markers suggested that extracellular vesicles were not present in the dialysate, but rather adsorbed to the dialysis membrane. CONCLUSIONS: In summary, hemodialysis is associated with reductions in circulating submicron particles including membrane MPs. Accordingly, there may be significant interdialytic variation in circulating submicron particles. Investigators interested in measuring extracellular vesicles in patients undergoing hemodialysis should therefore carefully consider the timing of biosampling.
Assuntos
Vesículas Extracelulares , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Diálise Renal , Anexina A5/sangue , Antígenos CD/sangue , Plaquetas/citologia , Plaquetas/imunologia , Caderinas/sangue , Micropartículas Derivadas de Células , Estudos de Coortes , Feminino , Citometria de Fluxo , Soluções para Hemodiálise/química , Humanos , Antígenos Comuns de Leucócito/sangue , Leucócitos/citologia , Leucócitos/imunologia , Masculino , Pessoa de Meia-Idade , Nanopartículas/análiseRESUMO
When recombinant human (rh) thyroid-stimulating hormone (TSH) is administered to thyroid cancer survivors, an acute extra-thyroidal effect raises pro-inflammatory cytokines and activates platelets. Thymic stromal lymphopoietin (TSLP) is a cytokine recently implicated in platelet activation. Our aim was to measure platelet microparticle levels after rhTSH stimulation in vivo, and to investigate TSLP expression in TSH-stimulated human adipocytes in culture. Blood samples for total and platelet microparticle analysis were obtained from thyroid cancer survivors before (day 1) and after rhTSH administration (day 5). Adipocytes, differentiated from stromal preadipocytes isolated from adipose tissue from surgical patients, were stimulated with TSH. TSLP mRNA expression, protein expression, and protein release into the adipocyte medium were measured. The level of platelet microparticles in thyroid cancer patients rose 5-fold after rhTSH stimulation. TSH upregulated TSLP mRNA expression in adipocytes in culture through a pathway that was inhibited by 66% by H89, a protein kinase A inhibitor. TSLP protein expression rose in response to TSH, and TSH-stimulated TSLP release into the medium was completely blocked by dexamethasone. In conclusion, TSLP is a novel TSH-responsive adipokine. Future studies will be needed to address the potential role of adipocyte-derived TSLP and whether it is linked to TSH-dependent platelet activation.
Assuntos
Adipócitos/metabolismo , Plaquetas/metabolismo , Citocinas/metabolismo , Ativação Plaquetária , Neoplasias da Glândula Tireoide/metabolismo , Tireotropina/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/patologia , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/patologia , Linfopoietina do Estroma do TimoAssuntos
Vesículas Extracelulares , Síndrome Nefrótica , Podócitos , Sistema Urinário , Criança , HumanosRESUMO
AIMS/HYPOTHESIS: Individuals with diabetes exhibit increases in circulating endothelial microparticles (eMPs, also referred to as endothelial microvesicles), which are associated with endothelial dysfunction and a heightened risk of cardiovascular complications. We have shown that eMPs are markers and mediators of vascular injury although their role in diabetes is unclear. We hypothesised that the composition and biological activity of eMPs are altered in response to high glucose exposure. We assessed the effects of high glucose on eMP formation, composition and signalling in cultured HUVECs. METHODS: eMPs were isolated from the media of HUVECs cultured under conditions of normal glucose (eMPNG), high glucose (eMPHG) or osmotic control of L-glucose (eMPLG). eMP size, concentration and surface charge were assessed by nanoparticle tracking analysis and flow cytometry. eMP protein composition was assessed by liquid chromatography-tandem mass spectrometry, and eMP-mediated effects on coagulation, reactive oxygen species (ROS) production and vessel function were assessed. RESULTS: Exposure of HUVECs to high glucose for 24 h caused a threefold increase in eMP formation, increased mean particle size (269 ± 18 nm vs 226 ± 11 nm) and decreased surface charge. Compared with eMPNG or eMPLG, eMPHG possessed approximately threefold greater pro-coagulant activity, stimulated HUVEC ROS production to a greater extent (~250% of eMPNG) and were more potent inhibitors of endothelial-dependent relaxation. Proteomic analysis of eMPs identified 1212 independent proteins of which 68 were exclusively found in eMPHG. Gene ontology analysis revealed that eMPHG-exclusive proteins were associated with signalling pathways related to blood coagulation, cell signalling and immune cell activation. CONCLUSIONS/INTERPRETATION: Our results indicate that elevated glucose is a potent stimulus for eMP formation that also alters their molecular composition leading to increased bioactivity. Such effects may contribute to progressive endothelial injury and subsequent cardiovascular complications in diabetes.
Assuntos
Glucose/metabolismo , Micropartículas Derivadas de Células/metabolismo , Endotélio Vascular/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Proteômica/métodos , Espécies Reativas de Oxigênio/metabolismoRESUMO
AIMS/HYPOTHESIS: Assessment of urinary extracellular vesicles including exosomes and microparticles (MPs) is an emerging approach for non-invasive detection of renal injury. We have previously reported that podocyte-derived MPs are increased in diabetic mice in advance of albuminuria. Here, we hypothesised that type 1 diabetes and acute hyperglycaemia would increase urinary podocyte MP levels in uncomplicated diabetes. METHODS: In this post hoc exploratory analysis, we examined archived urine samples from normoalbuminuric patients with uncomplicated type 1 diabetes studied under clamped euglycaemia and hyperglycaemia and compared with healthy controls. Urinary vesicles were assessed by electron microscopy and nanoparticle tracking while podocyte MPs were assessed by flow cytometry. RESULTS: Neither vesicle size nor total number were significantly altered in type 1 diabetes or acute hyperglycaemia. By contrast, urinary podocyte MP levels were higher in type 1 diabetes (0.47 [0.00-3.42] MPs/µmol creatinine [Cr]) compared with healthy controls (0.00 [0.00-0.00] MPs/µmol Cr, p < 0.05) and increased under hyperglycaemic clamp (0.36 [0.00-4.15] MPs/µmol Cr during euglycaemia vs 2.70 [0.00-15.91] MPs/µmol Cr during hyperglycaemia, p < 0.05). Levels of urinary albumin to creatinine ratio and nephrin (surrogates of podocyte injury) were unchanged by type 1 diabetes or acute hyperglycaemia. CONCLUSION/INTERPRETATION: Taken together, our data show that urinary podocyte MP levels are higher in patients with type 1 diabetes in advance of changes in other biomarkers (albuminuria, nephrin). Examination of podocyte MPs may serve as an early biomarker of glomerular injury in uncomplicated type 1 diabetes.
Assuntos
Pressão Sanguínea/fisiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 1/urina , Adulto , Albuminúria/urina , Biomarcadores/urina , Creatinina/metabolismo , Citometria de Fluxo , Humanos , Hiperglicemia/fisiopatologia , Hiperglicemia/urina , Masculino , Proteínas de Membrana , Microscopia Eletrônica , Microscopia Eletrônica de Transmissão , Nanopartículas , Podócitos/metabolismo , Podócitos/ultraestrutura , Adulto JovemRESUMO
The relationship between the renal renin-angiotensin aldosterone system (RAAS) and cardiorenal pathophysiology is unclear. Our aims were to assess 1) levels of urinary RAAS components and 2) the association between RAAS components and HbA1c, the urine albumin/creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and blood pressure (BP) in otherwise healthy adolescents with type 1 diabetes mellitus (TID) vs. healthy controls (HC). Urinary angiotensinogen and angtionsin-converting enzyme (ACE) 2 levels, activity of ACE and ACE2, BP, HbA1c, ACR, and eGFR were measured in 65 HC and 194 T1D from the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT). Urinary levels of all RAAS components were higher in T1D vs. HC (P < 0.0001). Higher HbA1c was associated with higher urinary angiotensinogen, ACE2, and higher activity of ACE and ACE2 (P < 0.0001, P = 0.0003, P = 0.003, and P = 0.007 respectively) in T1D. Higher ACR (within the normal range) was associated with higher urinary angiotensinogen (P < 0.0001) and ACE activity (P = 0.007), but not with urinary ACE2 activity or ACE2 levels. These observations were absent in HC. Urinary RAAS components were not associated with BP or eGFR in T1D or HC. Otherwise healthy adolescents with T1D exhibit higher levels of urinary RAAS components compared with HC. While levels of all urinary RAAS components correlate with HbA1c in T1D, only urinary angiotensinogen and ACE activity correlate with ACR, suggesting that these factors reflect an intermediary pathogenic link between hyperglycemia and albuminuria within the normal range.
Assuntos
Pressão Sanguínea/fisiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Rim/fisiopatologia , Sistema Renina-Angiotensina/fisiologia , Adolescente , Albuminúria/metabolismo , Angiotensinogênio/urina , Biomarcadores/metabolismo , Creatinina/urina , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Taxa de Filtração Glomerular/fisiologia , Humanos , Rim/metabolismo , Masculino , Peptidil Dipeptidase A/urinaRESUMO
Angiotensin-(1-7) is a ligand for the Mas receptor and may protect against tissue injury associated with renin-angiotensin system activation. We determined the effects of endogenous or exogenous angiotensin-(1-7) in mice with unilateral ureteral obstruction (UUO). Mice with UUO were treated with or without the angiotensin-(1-7) antagonist A779 or with 6, 24, or 62 µg/kg per hour exogenous angiotensin-(1-7). After 10 days, kidneys were harvested for histology, immunoblots, and measurement of NADPH oxidase. Compared with controls, A779 treatment significantly increased fibronectin, transforming growth factor-ß, and α-smooth muscle actin expression in obstructed kidneys and enhanced tubulointerstitial injury, apoptosis, and NADPH oxidase. Unexpectedly, administration of angiotensin-(1-7) to mice with UUO caused injury in obstructed kidneys compared with controls and increased macrophage infiltration. In obstructed kidneys from mice with gene deletion of Mas (Mas(-/-)), apoptosis and macrophage infiltration were increased compared with wild-type mice. Angiotensin-(1-7) (but not A779) further increased apoptosis and macrophage influx in obstructed kidneys from Mas(-/-) mice, compared with untreated Mas(-/-) mice. These data indicate that endogenous angiotensin-(1-7) protects against kidney injury in UUO. In mice with or without the Mas receptor, however, delivery of exogenous angiotensin-(1-7) worsens kidney damage. The results suggest dose-dependent effects of angiotensin-(1-7) in the kidney in UUO, with endogenous angiotensin-(1-7) promoting repair pathways via interaction with Mas and higher amounts exacerbating injury.
Assuntos
Angiotensina II/análogos & derivados , Angiotensina I/uso terapêutico , Fragmentos de Peptídeos/uso terapêutico , Ureter/efeitos dos fármacos , Obstrução Ureteral/tratamento farmacológico , Actinas/metabolismo , Angiotensina I/antagonistas & inibidores , Angiotensina I/farmacologia , Angiotensina II/farmacologia , Angiotensina II/uso terapêutico , Animais , Fibronectinas/metabolismo , Masculino , Camundongos , Músculo Liso/efeitos dos fármacos , Músculo Liso/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Ureter/metabolismo , Obstrução Ureteral/metabolismoRESUMO
Partner and localizer of BRCA2 (PALB2), plays an important functional role in DNA damage repair. Recent studies indicate that germline mutations in PALB2 predispose individuals to a high risk of developing familial breast cancer. Therefore, comprehensive identification of PALB2 germline mutations is potentially important for understanding their roles in tumorigenesis and for testing their potential utility as clinical targets. Most of the previous studies of PALB2 have focused on familial breast cancer cases with normal/wild-type BRCA1 and BRCA2 (BRCAx). We hypothesize that PALB2 genetic mutations also exist in individuals with BRCA mutations (BRCA+). To test this hypothesis, PALB2 germline mutations were screened in 107 exome data sets collected from familial breast cancer families who were either BRCA1+ or BRCAx. Two novel heterozygous mutations predicted to alter the function of PALB2 were identified (c.2014G>C, p.E672Q and c.2993G>A, p.G998E). Notably, both of these mutations co-existed in BRCA1+ and BRCA1x families. These studies show that mutations in PALB2 can occur independent of the status of BRCA1 mutations, and they highlight the importance to include BRCA1+ families in PALB2 mutation screens.
Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Masculino , LinhagemRESUMO
To study the in situ intestinal absorption of five oligosaccharides contained in Morinda officinalis How. (sucrose, kestose, nystose, 1F-Fructofuranosyinystose and Bajijiasu). The absorption of the five oligosaccharides in small intestine (duodenum, jejunum and ileum) and colon of rats and their contents were investigated by using in situ single-pass perfusion model and HPLC-ELSD. The effects of drug concentration, pH in perfusate and P-glycoprotein inhibitor on the intestinal absorption were investigated to define the intestinal absorption mechanism of the five oligosaccharides in rats. According to the results, all of the five oligosaccharides were absorbed in the whole intestine, and their absorption rates were affected by the pH of the perfusion solution, drug concentration and intestinal segments. Verapamil Hydrochloride could significantly increase the absorptive amount of sucrose and Bajijiasu, suggesting sucrose and Bajijiasu are P-gp's substrate. The five oligosaccharides are absorbed mainly through passive diffusion in the intestinal segments, without saturated absorption. They are absorbed well in all intestines and mainly in duodenum and jejunum.
Assuntos
Medicamentos de Ervas Chinesas/farmacocinética , Intestino Delgado/metabolismo , Morinda/química , Oligossacarídeos/farmacocinética , Animais , Medicamentos de Ervas Chinesas/química , Absorção Intestinal , Masculino , Oligossacarídeos/química , Perfusão , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: BRCA1 plays an essential role in maintaining genome stability. Inherited BRCA1 germline mutation (BRCA1+) is a determined genetic predisposition leading to high risk of breast cancer. While BRCA1+ induces breast cancer by causing genome instability, most of the knowledge is known about somatic genome instability in breast cancer cells but not germline genome instability. METHODS: Using the exome-sequencing method, we analyzed the genomes of blood cells in a typical BRCA1+ breast cancer family with an exon 13-duplicated founder mutation, including six breast cancer-affected and two breast cancer unaffected members. RESULTS: We identified 23 deleterious mutations in the breast cancer-affected family members, which are absent in the unaffected members. Multiple mutations damaged functionally important and breast cancer-related genes, including transcriptional factor BPTF and FOXP1, ubiquitin ligase CUL4B, phosphorylase kinase PHKG2, and nuclear receptor activator SRA1. Analysis of the mutations between the mothers and daughters shows that most mutations were germline mutation inherited from the ancestor(s) while only a few were somatic mutation generated de novo. CONCLUSION: Our study indicates that BRCA1+ can cause genome instability with both germline and somatic mutations in non-breast cells.
Assuntos
Proteína BRCA1/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Instabilidade Genômica , Adulto , Proteína BRCA1/sangue , Biomarcadores Tumorais/sangue , Neoplasias da Mama/sangue , Análise Mutacional de DNA , Éxons , Feminino , Efeito Fundador , Predisposição Genética para Doença , Hereditariedade , Humanos , Masculino , Pessoa de Meia-Idade , Mães , Mutação , Núcleo Familiar , Linhagem , FenótipoRESUMO
BACKGROUND: Genetic predisposition is the primary risk factor for familial breast cancer. For the majority of familial breast cancer, however, the genetic predispositions remain unknown. All newly identified predispositions occur rarely in disease population, and the unknown genetic predispositions are estimated to reach up to total thousands. Family unit is the basic structure of genetics. Because it is an autosomal dominant disease, individuals with a history of familial breast cancer must carry the same genetic predisposition across generations. Therefore, focusing on the cases in lineages of familial breast cancer, rather than pooled cases in disease population, is expected to provide high probability to identify the genetic predisposition for each family. METHODS: In this study, we tested genetic predispositions by analyzing the family-specific variants in familial breast cancer. Using exome sequencing, we analyzed three families and 22 probands with BRCAx (BRCA-negative) familial breast cancer. RESULTS: We observed the presence of family-specific, novel, deleterious germline variants in each family. Of the germline variants identified, many were shared between the disease-affected family members of the same family but not found in different families, which have their own specific variants. Certain variants are putative deleterious genetic predispositions damaging functionally important genes involved in DNA replication and damaging repair, tumor suppression, signal transduction, and phosphorylation. CONCLUSIONS: Our study demonstrates that the predispositions for many BRCAx familial breast cancer families can lie in each disease family. The application of a family-focused approach has the potential to detect many new predispositions.
Assuntos
Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Exoma , Feminino , Humanos , Modelos Biológicos , LinhagemRESUMO
Angiotensin-converting enzyme 2 (ACE2) is expressed in the kidney and may be renoprotective. We determined whether urinary ACE2 enzyme activity and protein levels (ELISA), as well as angiotensinogen and ACE, are elevated during clamped euglycemia (4-6 mmol·L(-1)) in patients with uncomplicated type 1 diabetes (T1D, n = 58) compared with normoglycemic controls (n = 21). We also measured the effect of clamped hyperglycemia (9-11 mmol·L(-1)) on each urinary factor in T1D patients. Urinary ACE2 activity and protein levels were higher during clamped euglycemia in T1D compared with the controls (p < 0.0001). In contrast, urinary angiotensinogen levels (p = 0.27) and ACE excretion (p = 0.68) did not differ. In response to clamped hyperglycemia in T1D, urinary ACE2 protein decreased (p < 0.0001), whereas urinary ACE2 activity as well as angiotensinogen and ACE levels remained unchanged. Urinary ACE2 activity and protein expression are increased in T1D patients prior to the onset of clinical complications. Further work is required to determine the functional role of urinary ACE2 in early T1D.
Assuntos
Diabetes Mellitus Tipo 1/urina , Peptidil Dipeptidase A/urina , Adulto , Enzima de Conversão de Angiotensina 2 , Angiotensinogênio/metabolismo , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Técnica Clamp de Glucose , Humanos , Masculino , Peptidil Dipeptidase A/metabolismoRESUMO
Genetic predisposition plays a key role in the development of familial breast cancer. In spite of strong familial clustering of the disease and extensive efforts made during the past decade; however, progress has been slow in identifying genetic predisposition for the majority of familial breast cancer families. The question arises therefore as to whether current approaches are adequate in identifying the unknown genetic predisposition. We analyzed eight members of a BRCA1-, BRCA2-, p53-, and PTEN-negative breast cancer family, of which five had breast cancer, one is an obligate gene carrier, and two were unaffected. We sequenced the entire coding region of the genome for each member using exome sequencing to identify nonsynonymous variants. We identified 55 nonsynonymous germline variants affecting 49 genes in multiple members of the family, of which 22 are predicted to have damaging effects. We validated 20 of the 22 selected variants in the family by Sanger sequencing. Two variants in KAT6B, an acetal transferase gene, were identified in six family members of which five were affected with breast cancer and one is the unaffected obligate carrier. We further examined the presence of the identified variants in a cohort of 40 additional breast cancer cases from 22 familial breast cancer families, but none of the 22 variants was detected in these cases. Sequencing the entire coding exons in KAT6B detects no variants in these cases. Our results show that genetic predisposition for familial breast cancer can be rich in an affected family, but the predisposition can be family-specific. As such, it will be difficult to detect them by applying population-based approach. Our study supports the concept that focusing on each affected family will be required to determine the genetic predisposition for many familial breast cancer families whose genetic dispositions remain unknown.
Assuntos
Neoplasias da Mama/congênito , Predisposição Genética para Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/genética , Feminino , Genes BRCA1 , Genes BRCA2 , Histona Acetiltransferases/genética , Humanos , Masculino , Pessoa de Meia-Idade , MutaçãoRESUMO
TP53 is crucial for maintaining genome stability and preventing oncogenesis. Germline pathogenic variation in TP53 damages its function, causing genome instability and increased cancer risk. Despite extensive study in TP53, the evolutionary origin of the human TP53 germline pathogenic variants remains largely unclear. In this study, we applied phylogenetic and archaeological approaches to identify the evolutionary origin of TP53 germline pathogenic variants in modern humans. In the phylogenic analysis, we searched 406 human TP53 germline pathogenic variants in 99 vertebrates distributed in eight clades of Primate, Euarchontoglires, Laurasiatheria, Afrotheria, Mammal, Aves, Sarcopterygii and Fish, but we observed no direct evidence for the cross-species conservation as the origin; in the archaeological analysis, we searched the variants in 5031 ancient human genomes dated between 45045 and 100 years before present, and identified 45 pathogenic variants in 62 ancient humans dated mostly within the last 8000 years; we also identified 6 pathogenic variants in 3 Neanderthals dated 44000 to 38515 years before present and 1 Denisovan dated 158 550 years before present. Our study reveals that TP53 germline pathogenic variants in modern humans were likely originated in recent human history and partially inherited from the extinct Neanderthals and Denisovans.