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1.
Methods ; 203: 116-124, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-33577982

RESUMEN

Rapid detection of nucleic acids is essential for clinical diagnosis of a wide range of infectious and non-infectious diseases. CRISPR-based diagnostic platforms are well-established for rapid and specific detection of nucleic acids but suffer from a low detection sensitivity without a target pre-amplification step. Our recently developed detection system, called CRISPR-ENHANCE, employs engineered crRNAs and optimized conditions to achieve a significantly higher sensitivity and enable femtomolar levels of nucleic acid detection even without target pre-amplification. Using the CRISPR-ENHANCE platform and following the methodology detailed in this paper, nucleic acid detection for low copy numbers can be achieved in less than an hour through either a fluorescence-based detection or a lateral flow assay. The step-by-step instructions provided, in addition to describing how to perform both assays, incorporate details on a LAMP/RT-LAMP-based target amplification step to enable detection of RNA, ssDNA and dsDNA. Furthermore, a protocol for in-house expression and purification of LbCas12a using CL7/lm7-based affinity chromatography, which has been used to achieve a high yield and purity of the enzyme in a single-step, is provided.


Asunto(s)
Ácidos Nucleicos , SARS-CoV-2 , Sistemas CRISPR-Cas/genética , ADN de Cadena Simple/genética , Técnicas de Amplificación de Ácido Nucleico/métodos
2.
Diabetes Obes Metab ; 24(10): 1939-1949, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35635331

RESUMEN

AIM: To determine, using a mouse model of obesity, whether low-dose hydralazine prevents obesity-related chronic kidney disease (CKD). METHODS: From 8 weeks of age, male C57BL/6 mice received a high-fat diet (HFD) or chow, with or without low-dose hydralazine (25 mg/L) in drinking water, for 24 weeks. Biometric and metabolic variables, renal function and structural changes, renal global DNA methylation, DNA methylation profile and markers of renal fibrosis, injury, inflammation and oxidative stress were assessed. RESULTS: The HFD-fed mice developed obesity, with glucose intolerance, hyperinsulinaemia and dyslipidaemia. Obesity increased albuminuria and glomerulosclerosis, which were significantly ameliorated by low-dose hydralazine in the absence of a blood pressure-lowering effect. Obesity increased renal global DNA methylation and this was attenuated by low-dose hydralazine. HFD-induced changes in methylation of individual loci were also significantly reversed by low-dose hydralazine. Obese mice demonstrated increased markers of kidney fibrosis, inflammation and oxidative stress, but these markers were not significantly improved by hydralazine. CONCLUSION: Low-dose hydralazine ameliorated HFD-induced albuminuria and glomerulosclerosis, independent of alterations in biometric and metabolic variables or blood pressure regulation. Although the precise mechanism of renoprotection in obesity is unclear, an epigenetic basis may be implicated. These data support repurposing hydralazine as a novel therapy to prevent CKD progression in obese patients.


Asunto(s)
Albuminuria , Insuficiencia Renal Crónica , Albuminuria/tratamiento farmacológico , Albuminuria/etiología , Albuminuria/prevención & control , Animales , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Fibrosis , Hidralazina/farmacología , Hidralazina/uso terapéutico , Inflamación/metabolismo , Riñón , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/tratamiento farmacológico
3.
J Med Virol ; 93(9): 5660-5665, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34042186

RESUMEN

Genome-wide analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains is essential to better understand infectivity and virulence and to track coronavirus disease 2019 (COVID-19) cases and outbreaks. We performed whole-genome sequencing of 27 SARS-CoV-2 strains isolated between January 2020 and April 2020. A total of 54 mutations in different genomic regions was found. The D614G mutation, first detected in March 2020, was identified in 18 strains and was more likely associated with a lower cycle threshold (<25) in real-time reverse-transcription polymerase chain reaction diagnostic tests than the original D614 (prevalence ratio = 2.75; 95% confidence interval, 1.19-6.38). The integration of sequencing and epidemiological data suggests that SARS-CoV-2 transmission in both quarantine areas and in the community in Vietnam occur at the beginning of the epidemic although the country implemented strict quarantine quite early, with strict contact tracing, and testing. These findings provide insights into the nature of the epidemic, as well as shape strategies for COVID-19 prevention and control in Vietnam.


Asunto(s)
COVID-19/virología , Variación Genética , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/genética , Adolescente , Adulto , Anciano , COVID-19/epidemiología , COVID-19/transmisión , Trazado de Contacto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Filogenia , Cuarentena , Análisis de Regresión , Vietnam/epidemiología , Secuenciación Completa del Genoma , Adulto Joven
4.
J Med Virol ; 92(10): 2209-2215, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32462705

RESUMEN

In January 2020, we identified two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients in a familial cluster with one person coming from Wuhan, China. The complete genome sequences of two SARS-CoV-2 strains isolated from these patients were identical and 99.98% similar to strains isolated in Wuhan. This is genetically suggestive of human-to-human transmission of SARS-CoV-2 and indicates Wuhan as the most plausible origin of the early outbreak in Vietnam. The younger patient had a mild upper respiratory illness and a brief viral shedding, whereas the elderly with multi-morbidity had pneumonia, prolonged viral shedding, and residual lung damage. The evidence of nonsynonymous substitutions in the ORF1ab region of the viral sequence warrants further studies.


Asunto(s)
COVID-19/transmisión , Genoma Viral , Pulmón/virología , SARS-CoV-2/genética , Adulto , Anciano , COVID-19/diagnóstico , COVID-19/patología , COVID-19/virología , China/epidemiología , Familia , Genotipo , Humanos , Pulmón/patología , Masculino , Mutación , Filogenia , SARS-CoV-2/clasificación , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/patogenicidad , Viaje , Vietnam/epidemiología , Replicación Viral , Secuenciación Completa del Genoma
5.
Int J Mol Sci ; 21(19)2020 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-33027895

RESUMEN

Maternal obesity can contribute to the development of obesity and related metabolic disorders in progeny. Sirtuin (SIRT)1, an essential regulator of metabolism and stress responses, has recently emerged as an important modifying factor of developmental programming. In this study, to elucidate the effects of parental SIRT1 overexpression on offspring mechanism, four experimental groups were included: (1) Chow-fed wild-type (WT)-dam × Chow-fed WT-sire; (2) High-fat diet (HFD)-fed WT-dam × Chow-fed WT-sire; (3) HFD-fed hemizygous SIRT1-transgenic (Tg)-dam × Chow-fed WT-sire; and (4) HFD-fed WT dam × Chow-fed Tg-sire. Our results indicate that Tg breeders had lower body weight and fat mass compared to WT counterparts and gave birth to WT offspring with reductions in body weight, adiposity and hyperlipidaemia compared to those born of WT parents. Maternal SIRT1 overexpression also reversed glucose intolerance, and normalised abnormal fat morphology and the expression of dysregulated lipid metabolism markers, including SIRT1. Despite having persistent hepatic steatosis, offspring born to Tg parents showed an improved balance of hepatic glucose/lipid metabolic markers, as well as reduced levels of inflammatory markers and TGF-ß/Smad3 fibrotic signalling. Collectively, the data suggest that parental SIRT1 overexpression can ameliorate adverse metabolic programming effects by maternal obesity.


Asunto(s)
Hígado Graso/genética , Inflamación/genética , Obesidad Materna/genética , Sirtuina 1/genética , Animales , Peso Corporal/genética , Dieta Alta en Grasa/efectos adversos , Hígado Graso/patología , Femenino , Regulación de la Expresión Génica/genética , Intolerancia a la Glucosa/metabolismo , Humanos , Inflamación/metabolismo , Inflamación/patología , Resistencia a la Insulina/genética , Metabolismo de los Lípidos/genética , Hígado/metabolismo , Hígado/patología , Enfermedades Metabólicas/genética , Enfermedades Metabólicas/metabolismo , Ratones , Obesidad Materna/metabolismo , Obesidad Materna/patología , Embarazo
6.
J Physiol ; 597(2): 467-480, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30381838

RESUMEN

KEY POINTS: Maternal high-fat diet (MHF) consumption led to metabolic and liver disorders in male offspring, which are associated with reduced sirtuin (SIRT)1 expression and activity in the offspring liver SIRT1 overexpression in MHF offspring reduced their body weight and adiposity and normalized lipid metabolic markers in epididymal and retroperitoneal adipose tissues SIRT1 overexpression in MHF offspring improved glucose tolerance, as well as systemic and hepatic insulin sensitivity SIRT1 overexpression ameliorated MHF-induced lipogenesis, oxidative stress and fibrogenesis in the liver of offspring. ABSTRACT: Maternal obesity can increase the risk of metabolic disorders in the offspring. However, the underlying mechanism responsible for this is not clearly understood. Previous evidence implied that sirtuin (SIRT)1, a potent regulator of energy metabolism and stress responses, may play an important role. In the present study, we have shown, in C57BL/6 mice, that maternal high-fat diet (HFD) consumption can induce a pre-diabetic and non-alcoholic fatty liver disease phenotype in the offspring, associated with reduced SIRT1 expression in the hypothalamus, white adipose tissues (WAT) and liver. Importantly, the overexpression of SIRT1 in these offspring significantly attenuated the excessive accumulation of epididymal (Epi) white adipose tissue (WAT) and retroperitoneal (Rp)WAT (P < 0.001), glucose intolerance and insulin resistance (both P < 0.05) at weaning age. These changes were associated with the suppression of peroxisome proliferator-activated receptor gamma (PPAR)γ (P < 0.01), PPARγ-coactivator 1-alpha (P < 0.05) and sterol regulatory element-binding protein-1c in EpiWAT (P < 0.01), whereas there was increased expression of PPARγ in RpWAT (P < 0.05). In the liver, PPARγ mRNA expression, as well as Akt protein expression and activity, were increased (P < 0.05), whereas fatty acid synthase and carbohydrate response element binding protein were downregulated (P < 0.05), supporting increased insulin sensitivity and reduced lipogenesis in the liver. In addition, hepatic expression of endogenous anti-oxidants, including glutathione peroxidase 1 and catalase, was increased (P < 0.01 and P < 0.05 respectively), whereas collagen and fibronectin deposition was suppressed (P < 0.01). Collectively, the present study provides direct evidence of the mechanistic significance of SIRT1 in maternal HFD-induced metabolic dysfunction in offspring and suggests that SIRT1 is a promising target for fetal reprogramming.


Asunto(s)
Dieta Alta en Grasa , Hepatopatías/metabolismo , Enfermedades Metabólicas/metabolismo , Efectos Tardíos de la Exposición Prenatal , Sirtuina 1/metabolismo , Adipocitos/patología , Adiposidad , Animales , Peso Corporal , Ingestión de Alimentos , Femenino , Glucosa/metabolismo , Hipertrofia , Resistencia a la Insulina , Ratones Endogámicos C57BL , Embarazo
7.
FASEB J ; 30(4): 1383-90, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26667041

RESUMEN

Obesity is a complex metabolic disease, attributed to diverse and interactive genetic and environmental factors. The associated health consequences of obesity are pleiotropic, with individuals being more susceptible to chronic diseases such as type 2 diabetes mellitus, hypertension, and lipotoxicity-related chronic diseases. The contribution of maternal obesity to the offspring's predisposition to both obesity and its complications is increasingly recognized. Understanding the mechanisms underlying these "transmissible" effects is critical to develop therapeutic interventions to reduce the risk for "programmed" obesity. Sirtuins (SIRTs), particularly SIRT1 and SIRT3, are NAD(+)-dependent deacetylases that regulate metabolic balance and stress responses in both central and peripheral tissues, of which dysregulation is a well-established mediator for the development and effects of obesity. Nevertheless, their implication in the transmissible effects of maternal obesity across generations remains largely elusive. In this review, we examine multiple pathways and systems that are likely to mediate such effects, with particular emphasis on the role of SIRTs.-Nguyen, L. T., Chen, H., Pollock, C. A., Saad, S. Sirtuins-mediators of maternal obesity-induced complications in offspring?


Asunto(s)
Fenómenos Fisiologicos Nutricionales Maternos , Obesidad/fisiopatología , Complicaciones del Embarazo/fisiopatología , Sirtuinas/metabolismo , Animales , Femenino , Humanos , Modelos Biológicos , Obesidad/metabolismo , Embarazo , Complicaciones del Embarazo/metabolismo , Transducción de Señal
9.
Am J Physiol Renal Physiol ; 308(7): F689-96, 2015 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-25608965

RESUMEN

Maternal smoking is associated with metabolic disorders, renal underdevelopment, and a predisposition to chronic kidney disease in offspring, yet the underlying mechanisms are unclear. By exposing female Balb/c mice to cigarette smoke for 6 wk premating and during gestation and lactation, we showed that maternal smoke exposure induced glucose intolerance, renal underdevelopment, inflammation, and albuminuria in male offspring. This was associated with increased renal oxidative stress and mitochondrial dysfunction at birth and in adulthood. Importantly, we demonstrated that dietary supplementation of l-carnitine, an amino acid shown to increase antioxidant defenses and mitochondrial function in numerous diseases, in smoke-exposed mothers during pregnancy and lactation significantly reversed the detrimental maternal impacts on kidney pathology in these male offspring. It increased SOD2 and glutathione peroxidase 1, reduced ROS accumulation, and normalized levels of mitochondrial preprotein translocases of the outer membrane, and oxidative phosphorylation complexes I-V in the kidneys of mouse progeny after intrauterine cigarette smoke exposure. These findings support the hypothesis that oxidative stress and mitochondrial dysfunction are closely linked to the adverse effects of maternal smoking on male offspring renal pathology. The results of our study suggest that l-carnitine administration in cigarette smoke-exposed mothers mitigates these deleterious renal consequences.


Asunto(s)
Carnitina/farmacología , Exposición Materna/efectos adversos , Mitocondrias/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fumar , Animales , Animales Recién Nacidos , Femenino , Riñón/efectos de los fármacos , Riñón/metabolismo , Masculino , Ratones Endogámicos BALB C , Mitocondrias/metabolismo , Oxidación-Reducción/efectos de los fármacos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Complejo Vitamínico B/farmacología
10.
BMC Infect Dis ; 14: 362, 2014 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-24992826

RESUMEN

BACKGROUND: Sporadic emergence of the highly pathogenic avian influenza (HPAI) H5N1 virus infection in humans is a serious concern because of the potential for a pandemic. Conventional or quantitative RT-PCR is the standard laboratory test to detect viral influenza infections. However, this technology requires well-equipped laboratories and highly trained personnel. A rapid, sensitive, and specific alternative screening method is needed. METHODS: By a luminescence-linked enzyme immunoassay, we have developed a H5N1 HPAI virus detection kit using anti-H5 hemagglutinin monoclonal antibodies in combination with the detection of a universal NP antigen of the type A influenza virus. The process takes 15 minutes by use of the fully automated luminescence analyzer, POCube. RESUTLS: We tested this H5/A kit using 19 clinical specimens from 13 patients stored in Vietnam who were infected with clade 1.1 or clade 2.3.4 H5N1 HPAI virus. Approximately 80% of clinical specimens were H5-positive using the POCube system, whereas only 10% of the H5-positive samples were detected as influenza A-positive by an immunochromatography-based rapid diagnostic kit. CONCLUSIONS: This novel H5/A kit using POCube is served as a rapid and sensitive screening test for H5N1 HPAI virus infection in humans.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/virología , Humanos , Técnicas para Inmunoenzimas , Faringe/virología , Juego de Reactivos para Diagnóstico , Sensibilidad y Especificidad , Vietnam
11.
BMC Infect Dis ; 14: 341, 2014 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-24942066

RESUMEN

BACKGROUND: In 2011, a large outbreak of hand, foot and mouth disease (HFMD) in Vietnam resulted in 113,121 children seeking medical attention, of whom170 died. Understanding the epidemiology of fatal HFMD may improve treatment and help targeting prevention activities for vulnerable populations. We describe epidemiological and clinical characteristics of children who died from HFMD in Vietnam in 2011. METHODS: Clinical data were obtained through reviewing medical records of the deaths occurring from January through December 2011 in all hospitals in Vietnam. Hospitals reported any deaths among patients with laboratory-confirmed enterovirus (EV) infection to the Ministry of Health. Data were extracted from the national database. RESULTS: Of the 169 deaths reviewed for whom records were available, 87% were 3-year-old or younger, 69% were male, 18% attended daycare, 89% lived in Southern Vietnam, and 85% of the deaths occurred between May-October 2011. One hundred thirty (77%) cases sought treatment in a hospital within three days of onset of illness. Symptoms at admission included fever (98%), myoclonus (66%), vomiting (53%), oral ulcers (50%) and vesicular erythema (50%). One hundred six (75%) cases had leukocytosis and 91 (54%) had hyperglycemia. One hundred three (61%) tested positive for EV, of which 84 (82%) were positive for EV71. CONCLUSIONS: Deaths associated with HFMD occurred throughout 2011 among males three years or younger who were cared for at home. The HFMD control program should focus on interventions at the household level. Clinicians should be alerted to symptoms suggestive of severe HFMD including fever, myoclonus, vomiting, oral ulcers and vesicles with high white blood cell count especially in young children.


Asunto(s)
Infecciones por Enterovirus/epidemiología , Infecciones por Enterovirus/mortalidad , Enterovirus/aislamiento & purificación , Enfermedad de Boca, Mano y Pie/epidemiología , Niño , Preescolar , Bases de Datos Factuales , Brotes de Enfermedades , Enterovirus/clasificación , Enterovirus/genética , Infecciones por Enterovirus/microbiología , Femenino , Enfermedad de Boca, Mano y Pie/microbiología , Enfermedad de Boca, Mano y Pie/mortalidad , Hospitalización , Humanos , Lactante , Masculino , Vietnam/epidemiología
12.
Sci Rep ; 14(1): 8628, 2024 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622175

RESUMEN

Peripheral blood RNA profiling, which can reveal systemic changes in gene expression and immune responses to disease onset and progression, is a powerful tool for diagnosis and biomarker discovery. This technique usually requires high quality RNA, which is only obtainable from fresh blood, or frozen blood that has been collected in special RNA-stabilisation systems. The current study aimed to develop a novel protocol to extract high quality RNA from frozen blood that had been collected in the conventional EDTA tubes. We determined that thawing EDTA blood in the presence of cell lysis/RNA stabilisation buffers (Paxgene or Nucleospin) significantly improved RNA quality (RIN) from below 5 to above 7, which to date has not been shown possible. The EDTA-Nucleospin protocol resulted in 5 times higher yield than the EDTA-Paxgene-PreAnalytix method. The average RIN and mRNA expression levels of five different genes including 18 s, ACTB, MCP1, TNFa and TXNIP using this protocol were also indifferent to those from Paxgene blood, suggesting similar RNA quality and blood transcriptome. Moreover, the protocol allows DNA to be extracted simultaneously. In conclusion, we have developed a practical and efficient protocol to extract high quality, high yield RNA from frozen EDTA blood.


Asunto(s)
Perfilación de la Expresión Génica , ARN , ARN/genética , Ácido Edético/farmacología , Perfilación de la Expresión Génica/métodos , Recolección de Muestras de Sangre/métodos , Transcriptoma
13.
Cell Rep ; 43(2): 113777, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38358883

RESUMEN

There is a broad diversity among Cas12a endonucleases that possess nucleic acid detection and gene-editing capabilities, but few are studied extensively. Here, we present an exhaustive investigation of 23 Cas12a orthologs, with a focus on their cis- and trans-cleavage activities in combination with noncanonical crRNAs. Through biochemical assays, we observe that some noncanonical crRNA:Cas12a effector complexes outperform their corresponding wild-type crRNA:Cas12a. Cas12a can recruit crRNA with modifications such as loop extensions and split scaffolds. Moreover, the tolerance of Cas12a to noncanonical crRNA is also observed in mammalian cells through the formation of indels. We apply the adaptability of Cas12a:crRNA complexes to detect SARS-CoV-2 in clinical nasopharyngeal swabs, saliva samples, and tracheal aspirates. Our findings further expand the toolbox for next-generation CRISPR-based diagnostics and gene editing.


Asunto(s)
Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , Animales , Sistemas CRISPR-Cas/genética , Edición Génica , Endonucleasas/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Mamíferos/metabolismo
14.
Mol Ecol Resour ; 24(1): e13881, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37888995

RESUMEN

Rapid identification of organisms is essential for many biological and medical disciplines, from understanding basic ecosystem processes, disease diagnosis, to the detection of invasive pests. CRISPR-based diagnostics offers a novel and rapid alternative to other identification methods and can revolutionize our ability to detect organisms with high accuracy. Here we describe a CRISPR-based diagnostic developed with the universal cytochrome-oxidase 1 gene (CO1). The CO1 gene is the most sequenced gene among Animalia, and therefore our approach can be adopted to detect nearly any animal. We tested the approach on three difficult-to-identify moth species (Keiferia lycopersicella, Phthorimaea absoluta and Scrobipalpa atriplicella) that are major invasive pests globally. We designed an assay that combines recombinase polymerase amplification (RPA) with CRISPR for signal generation. Our approach has a much higher sensitivity than real-time PCR assays and achieved 100% accuracy for identification of all three species, with a detection limit of up to 120 fM for P. absoluta and 400 fM for the other two species. Our approach does not require a sophisticated laboratory, reduces the risk of cross-contamination, and can be completed in less than 1 h. This work serves as a proof of concept that has the potential to revolutionize animal detection and monitoring.


Asunto(s)
Ecosistema , Lepidópteros , Animales , Insectos , Bioensayo , Complejo IV de Transporte de Electrones/genética
15.
bioRxiv ; 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-39026836

RESUMEN

Prime editing has emerged as a precise and powerful genome editing tool, offering a favorable gene editing profile compared to other Cas9-based approaches. Here we report new nCas9-DNA polymerase fusion proteins to create chimeric oligonucleotide-directed editing (CODE) systems for search-and-replace genome editing. Through successive rounds of engineering, we developed CODEMax and CODEMax(exo+) editors that achieve efficient genome modifications in human cells with low unintended edits. CODEMax and CODEMax(exo+) contain an engineered Bst DNA polymerase derivative known for its robust strand displacement ability. Additionally, CODEMax(exo+) features a 5' to 3' exonuclease activity that promotes effective strand invasion and repair outcomes favoring the incorporation of the desired edit. We demonstrate CODEs can perform small insertions, deletions, and substitutions with improved efficiency compared to PEMax at many loci. Overall, CODEs complement existing prime editors to expand the toolbox for genome manipulations without double-stranded breaks.

16.
medRxiv ; 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38746294

RESUMEN

Type V CRISPR-Cas effectors have revolutionized molecular diagnostics by facilitating the detection of nucleic acid biomarkers. However, their dependence on the presence of protospacer adjacent motif (PAM) sites on the target double-stranded DNA (dsDNA) greatly limits their flexibility as diagnostic tools. Here we present a novel method named PICNIC that solves the PAM problem for CRISPR-based diagnostics with just a simple ∼10-min modification to contemporary CRISPR-detection protocols. Our method involves the separation of dsDNA into individual single-stranded DNA (ssDNA) strands through a high- temperature and high-pH treatment. We then detect the released ssDNA strands with diverse Cas12 enzymes in a PAM-free manner. We show the utility of PICNIC by successfully applying it for PAM-free detection with three different subtypes of the Cas12 family- Cas12a, Cas12b, and Cas12i. Notably, by combining PICNIC with a truncated 15-nucleotide spacer containing crRNA, we demonstrate PAM-independent detection of clinically important single- nucleotide polymorphisms with CRISPR. We apply this approach to detect the presence of a drug-resistant variant of HIV-1, specifically the K103N mutant, that lacks a PAM site in the vicinity of the mutation. Additionally, we successfully translate our approach to clinical samples by detecting and genotyping HCV-1a and HCV-1b variants with 100% specificity at a PAM-less site within the HCV genome. In summary, PICNIC is a simple yet groundbreaking method that enhances the flexibility and precision of CRISPR-Cas12-based diagnostics by eliminating the restriction of the PAM sequence.

17.
Trop Med Int Health ; 18(2): 212-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23210600

RESUMEN

OBJECTIVE: To assess the out-of-pocket (OOP) payments for health-care services of HIV/AIDS patients, and identify associated factors in Vietnam. METHODS: Cross-sectional multisite survey of 1016 HIV/AIDS patients attending 7 hospitals and health centres in Ha Noi, Hai Phong and Ho Chi Minh City in 2012. RESULTS: HIV/AIDS patients used inpatient and outpatient care on average 5.1 times (95% CI = 4.7-5.4) besides ART services. Inpatient care cost US$ 461 on average and outpatient care US$ 50. Mean annual health-care expenditure for HIV/AIDS patients was US$ 188 (95% CI = 148-229). 35.1% of households (95% CI = 32.2-38.1) experienced catastrophic health expenditure; 73.3% (95% CI = 70.6-76.1) of households would be affected if ART were not subsidised. Being a patient at a provincial clinic, male sex, unstable employment, being in the poorest income quintile, a CD4 count of <200 cells/mL and not yet receiving ART increased the likelihood of catastrophic medical expense. CONCLUSIONS: HIV/AIDS patients in Vietnam frequently use medical services and incur OOP payments for health care. Scaling up free-of-charge ART services, earlier access to and initiation of ART, and decentralisation and integration of HIV/AIDS-related services could reduce their financial burden.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/economía , Antirretrovirales/economía , Terapia Antirretroviral Altamente Activa/economía , Infecciones por VIH/economía , Costos de la Atención en Salud , Gastos en Salud/estadística & datos numéricos , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Adulto , Antirretrovirales/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Estudios Transversales , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Aceptación de la Atención de Salud/psicología , Factores Socioeconómicos , Vietnam/epidemiología
18.
Nutrients ; 15(19)2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37836490

RESUMEN

The developmental programming hypothesis proposes that adverse environmental insults during critical developmental periods increase the risk of diseases later in life. The kidneys are deemed susceptible to such a process, although the exact mechanisms remain elusive. Many factors have been reported to contribute to the developmental origin of chronic kidney diseases (CKD), among which peri-gestational nutrition has a central role, affecting kidney development and metabolism. Physiologically, the link between malnutrition, reduced glomerular numbers, and increased blood pressure is key in the developmental programming of CKD. However, recent studies regarding oxidative stress, mitochondrial dysfunction, epigenetic modifications, and metabolic changes have revealed potential novel pathways for therapeutic intervention. This review will discuss the role of imbalanced nutrition in the development of CKD.


Asunto(s)
Desnutrición , Insuficiencia Renal Crónica , Embarazo , Femenino , Humanos , Fenómenos Fisiologicos de la Nutrición Prenatal , Estado Nutricional , Desnutrición/complicaciones , Epigénesis Genética , Insuficiencia Renal Crónica/etiología
19.
bioRxiv ; 2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36778248

RESUMEN

CRISPR is a prominent bioengineering tool and the type V CRISPR-associated protein complex, Cas12a, is widely used in diagnostic platforms due to its innate ability to cleave DNA substrates. Here we demonstrate that Cas12a can also be programmed to directly detect RNA substrates without the need for reverse transcription or strand displacement. We discovered that while the PAM-proximal "seed" region of the crRNA exclusively recognizes DNA for initiating trans- cleavage, the PAM-distal region or 3'-end of the crRNA can tolerate both RNA and DNA substrates. Utilizing this property, we developed a method named Split Activators for Highly Accessible RNA Analysis or 'SAHARA' to detect RNA sequences at the PAM-distal region of the crRNA by merely supplying a short ssDNA or a PAM containing dsDNA to the seed region. Notably, SAHARA is Mg 2+ concentration- and pH-dependent, and it was observed to work robustly at room temperature with multiple orthologs of Cas12a. SAHARA also displayed a significant improvement in the specificity for target recognition as compared to the wild-type CRISPR-Cas12a, at certain positions along the crRNA. By employing SAHARA we achieved amplification-free detection of picomolar concentrations of miRNA-155 and hepatitis C virus RNA. Finally, SAHARA can use a PAM-proximal DNA as a switch to control the trans-cleavage activity of Cas12a for the detection of both DNA and RNA targets. With this, multicomplex arrays can be made to detect distinct DNA and RNA targets with pooled crRNA/Cas12a complexes. In conclusion, SAHARA is a simple, yet powerful nucleic acid detection platform based on Cas12a that can be applied in a multiplexed fashion and potentially be expanded to other CRISPR-Cas enzymes.

20.
Res Sq ; 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36824842

RESUMEN

CRISPR is a prominent bioengineering tool and the type V CRISPR-associated protein complex, Cas12a, is widely used in diagnostic platforms due to its innate ability to cleave DNA substrates. Here we demonstrate that Cas12a can also be programmed to directly detect RNA substrates without the need for reverse transcription or strand displacement. We discovered that while the PAM-proximal "seed" region of the crRNA exclusively recognizes DNA for initiating trans-cleavage, the PAM-distal region or 3'-end of the crRNA can tolerate both RNA and DNA substrates. Utilizing this property, we developed a method named Split Activators for Highly Accessible RNA Analysis or 'SAHARA' to detect RNA sequences at the PAM-distal region of the crRNA by merely supplying a short ssDNA or a PAM containing dsDNA to the seed region. Notably, SAHARA is Mg2+ concentration- and pH-dependent, and it was observed to work robustly at room temperature with multiple orthologs of Cas12a. SAHARA also displayed a significant improvement in the specificity for target recognition as compared to the wild-type CRISPR-Cas12a, at certain positions along the crRNA. By employing SAHARA we achieved amplification-free detection of picomolar concentrations of miRNA-155 and hepatitis C virus RNA. Finally, SAHARA can use a PAM-proximal DNA as a switch to control the trans-cleavage activity of Cas12a for the detection of both DNA and RNA targets. With this, multicomplex arrays can be made to detect distinct DNA and RNA targets with pooled crRNA/Cas12a complexes. In conclusion, SAHARA is a simple, yet powerful nucleic acid detection platform based on Cas12a that can be applied in a multiplexed fashion and potentially be expanded to other CRISPR-Cas enzymes.

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