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1.
Cell ; 163(5): 1204-1213, 2015 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-26582133

RESUMO

Duchenne muscular dystrophy (DMD), caused by mutations at the dystrophin gene, is the most common form of muscular dystrophy. There is no cure for DMD and current therapeutic approaches to restore dystrophin expression are only partially effective. The absence of dystrophin in muscle results in dysregulation of signaling pathways, which could be targets for disease therapy and drug discovery. Previously, we identified two exceptional Golden Retriever muscular dystrophy (GRMD) dogs that are mildly affected, have functional muscle, and normal lifespan despite the complete absence of dystrophin. Now, our data on linkage, whole-genome sequencing, and transcriptome analyses of these dogs compared to severely affected GRMD and control animals reveals that increased expression of Jagged1 gene, a known regulator of the Notch signaling pathway, is a hallmark of the mild phenotype. Functional analyses demonstrate that Jagged1 overexpression ameliorates the dystrophic phenotype, suggesting that Jagged1 may represent a target for DMD therapy in a dystrophin-independent manner. PAPERCLIP.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Modelos Animais de Doenças , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Distrofia Muscular de Duchenne/genética , Animais , Proliferação de Células , Doenças do Cão/genética , Cães , Distrofina/deficiência , Distrofina/genética , Feminino , Estudo de Associação Genômica Ampla , Proteína Jagged-1 , Masculino , Camundongos , Distrofia Muscular Animal/genética , Linhagem , Penetrância , Proteínas Serrate-Jagged , Transcriptoma , Peixe-Zebra , Proteínas de Peixe-Zebra
2.
Nature ; 619(7970): 585-594, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37468583

RESUMO

Understanding kidney disease relies on defining the complexity of cell types and states, their associated molecular profiles and interactions within tissue neighbourhoods1. Here we applied multiple single-cell and single-nucleus assays (>400,000 nuclei or cells) and spatial imaging technologies to a broad spectrum of healthy reference kidneys (45 donors) and diseased kidneys (48 patients). This has provided a high-resolution cellular atlas of 51 main cell types, which include rare and previously undescribed cell populations. The multi-omic approach provides detailed transcriptomic profiles, regulatory factors and spatial localizations spanning the entire kidney. We also define 28 cellular states across nephron segments and interstitium that were altered in kidney injury, encompassing cycling, adaptive (successful or maladaptive repair), transitioning and degenerative states. Molecular signatures permitted the localization of these states within injury neighbourhoods using spatial transcriptomics, while large-scale 3D imaging analysis (around 1.2 million neighbourhoods) provided corresponding linkages to active immune responses. These analyses defined biological pathways that are relevant to injury time-course and niches, including signatures underlying epithelial repair that predicted maladaptive states associated with a decline in kidney function. This integrated multimodal spatial cell atlas of healthy and diseased human kidneys represents a comprehensive benchmark of cellular states, neighbourhoods, outcome-associated signatures and publicly available interactive visualizations.


Assuntos
Perfilação da Expressão Gênica , Nefropatias , Rim , Análise de Célula Única , Transcriptoma , Humanos , Núcleo Celular/genética , Rim/citologia , Rim/lesões , Rim/metabolismo , Rim/patologia , Nefropatias/metabolismo , Nefropatias/patologia , Transcriptoma/genética , Estudos de Casos e Controles , Imageamento Tridimensional
4.
Hum Mol Genet ; 30(3-4): 149-159, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33432327

RESUMO

The dystrophin-glycoprotein complex (DGC) is a membrane adhesion complex that provides structural stability at the sarcolemma by linking the myocyte's internal cytoskeleton and external extracellular matrix. In Duchenne muscular dystrophy (DMD), the absence of dystrophin leads to the loss of the DGC at the sarcolemma, resulting in sarcolemmal instability and progressive muscle damage. Utrophin (UTRN), an autosomal homolog of dystrophin, is upregulated in dystrophic muscle and partially compensates for the loss of dystrophin in muscle from patients with DMD. Here, we examine the interaction between Utr and sarcospan (SSPN), a small transmembrane protein that is a core component of both UTRN-glycoprotein complex (UGC) and DGC. We show that additional loss of SSPN causes an earlier onset of disease in dystrophin-deficient mdx mice by reducing the expression of the UGC at the sarcolemma. In order to further evaluate the role of SSPN in maintaining therapeutic levels of Utr at the sarcolemma, we tested the effect of Utr transgenic overexpression in mdx mice lacking SSPN (mdx:SSPN -/-:Utr-Tg). We found that overexpression of Utr restored SSPN to the sarcolemma in mdx muscle but that the ablation of SSPN in mdx muscle reduced Utr at the membrane. Nevertheless, Utr overexpression reduced central nucleation and improved grip strength in both lines. These findings demonstrate that high levels of Utr transgenic overexpression ameliorate the mdx phenotype independently of SSPN expression but that loss of SSPN may impair Utr-based mechanisms that rely on lower levels of Utr protein.


Assuntos
Distrofina/genética , Proteínas de Membrana/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Proteínas de Neoplasias/metabolismo , Sarcolema/metabolismo , Utrofina/metabolismo , Animais , Feminino , Regulação da Expressão Gênica , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Mutação , Proteínas de Neoplasias/genética , Utrofina/genética
5.
Nature ; 550(7675): 244-248, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-29022598

RESUMO

X chromosome inactivation (XCI) silences transcription from one of the two X chromosomes in female mammalian cells to balance expression dosage between XX females and XY males. XCI is, however, incomplete in humans: up to one-third of X-chromosomal genes are expressed from both the active and inactive X chromosomes (Xa and Xi, respectively) in female cells, with the degree of 'escape' from inactivation varying between genes and individuals. The extent to which XCI is shared between cells and tissues remains poorly characterized, as does the degree to which incomplete XCI manifests as detectable sex differences in gene expression and phenotypic traits. Here we describe a systematic survey of XCI, integrating over 5,500 transcriptomes from 449 individuals spanning 29 tissues from GTEx (v6p release) and 940 single-cell transcriptomes, combined with genomic sequence data. We show that XCI at 683 X-chromosomal genes is generally uniform across human tissues, but identify examples of heterogeneity between tissues, individuals and cells. We show that incomplete XCI affects at least 23% of X-chromosomal genes, identify seven genes that escape XCI with support from multiple lines of evidence and demonstrate that escape from XCI results in sex biases in gene expression, establishing incomplete XCI as a mechanism that is likely to introduce phenotypic diversity. Overall, this updated catalogue of XCI across human tissues helps to increase our understanding of the extent and impact of the incompleteness in the maintenance of XCI.


Assuntos
Especificidade de Órgãos/genética , Análise de Célula Única , Inativação do Cromossomo X/genética , Cromossomos Humanos X/genética , Feminino , Genes Ligados ao Cromossomo X/genética , Genoma Humano/genética , Genômica , Humanos , Masculino , Fenótipo , Análise de Sequência de RNA , Transcriptoma/genética
6.
Proc Natl Acad Sci U S A ; 117(52): 33404-33413, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33376219

RESUMO

Single-cell quantification of RNAs is important for understanding cellular heterogeneity and gene regulation, yet current approaches suffer from low sensitivity for individual transcripts, limiting their utility for many applications. Here we present Hybridization of Probes to RNA for sequencing (HyPR-seq), a method to sensitively quantify the expression of hundreds of chosen genes in single cells. HyPR-seq involves hybridizing DNA probes to RNA, distributing cells into nanoliter droplets, amplifying the probes with PCR, and sequencing the amplicons to quantify the expression of chosen genes. HyPR-seq achieves high sensitivity for individual transcripts, detects nonpolyadenylated and low-abundance transcripts, and can profile more than 100,000 single cells. We demonstrate how HyPR-seq can profile the effects of CRISPR perturbations in pooled screens, detect time-resolved changes in gene expression via measurements of gene introns, and detect rare transcripts and quantify cell-type frequencies in tissue using low-abundance marker genes. By directing sequencing power to genes of interest and sensitively quantifying individual transcripts, HyPR-seq reduces costs by up to 100-fold compared to whole-transcriptome single-cell RNA-sequencing, making HyPR-seq a powerful method for targeted RNA profiling in single cells.


Assuntos
Sondas de DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Hibridização de Ácido Nucleico , RNA/metabolismo , Análise de Célula Única , Animais , Sistemas CRISPR-Cas/genética , Expressão Gênica , Humanos , Íntrons/genética , Células K562 , Rim/citologia , Camundongos , Poliadenilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células THP-1 , Fatores de Tempo
7.
Ann Neurol ; 83(6): 1105-1124, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29691892

RESUMO

OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder. METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients. RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder. INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.


Assuntos
Cardiomiopatia Dilatada/congênito , Conectina/genética , Proteínas Musculares/genética , Músculo Esquelético/patologia , Feminino , Humanos , Masculino , Mutação/genética , Fenótipo , Isoformas de Proteínas/genética
8.
Hum Mol Genet ; 25(24): 5395-5406, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27798107

RESUMO

Duchenne muscular dystrophy (DMD) is a genetic disorder that causes progressive muscle weakness, ultimately leading to early mortality in affected teenagers and young adults. Previous work from our lab has shown that a small transmembrane protein called sarcospan (SSPN) can enhance the recruitment of adhesion complex proteins to the cell surface. When human SSPN is expressed at three-fold levels in mdx mice, this increase in adhesion complex abundance improves muscle membrane stability, preventing many of the histopathological changes associated with DMD. However, expressing higher levels of human SSPN (ten-fold transgenic expression) causes a severe degenerative muscle phenotype in wild-type mice. Since SSPN-mediated stabilization of the sarcolemma represents a promising therapeutic strategy in DMD, it is important to determine whether SSPN can be introduced at high levels without toxicity. Here, we show that mouse SSPN (mSSPN) can be overexpressed at 30-fold levels in wild-type mice with no deleterious effects. In mdx mice, mSSPN overexpression improves dystrophic pathology and sarcolemmal stability. We show that these mice exhibit increased resistance to eccentric contraction-induced damage and reduced fatigue following exercise. mSSPN overexpression improved pulmonary function and reduced dystrophic histopathology in the diaphragm. Together, these results demonstrate that SSPN overexpression is well tolerated in mdx mice and improves sarcolemma defects that underlie skeletal muscle and pulmonary dysfunction in DMD.


Assuntos
Proteínas de Transporte/genética , Proteínas de Membrana/genética , Distrofia Muscular de Duchenne/genética , Proteínas de Neoplasias/genética , Sarcolema/genética , Animais , Proteínas de Transporte/biossíntese , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Pneumopatias/genética , Pneumopatias/patologia , Proteínas de Membrana/biossíntese , Camundongos , Camundongos Endogâmicos mdx , Camundongos Transgênicos , Contração Muscular/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Proteínas de Neoplasias/biossíntese , Sarcolema/patologia
9.
Hum Mol Genet ; 24(7): 2011-22, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25504048

RESUMO

Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene that result in loss of the dystrophin-glycoprotein complex, a laminin receptor that connects the myofiber to its surrounding extracellular matrix. Utrophin, a dystrophin ortholog that is normally localized to the neuromuscular junction, is naturally upregulated in DMD muscle, which partially compensates for the loss of dystrophin. Transgenic overexpression of utrophin causes broad sarcolemma localization of utrophin, restoration of laminin binding and amelioration of disease in the mdx mouse model of DMD. We previously demonstrated that overexpression of sarcospan, a dystrophin- and utrophin-binding protein, ameliorates mdx muscular dystrophy. Sarcospan boosts levels of utrophin to therapeutic levels at the sarcolemma, where attachment to laminin is restored. However, understanding the compensatory mechanism is complicated by concomitant upregulation of α7ß1 integrin, which also binds laminin. Similar to the effects of utrophin, transgenic overexpression of α7 integrin prevents DMD disease in mice and is accompanied by increased abundance of utrophin around the extra-synaptic sarcolemma. In order to investigate the mechanisms underlying sarcospan 'rescue' of muscular dystrophy, we created double-knockout mice to test the contributions of utrophin or α7 integrin. We show that sarcospan-mediated amelioration of muscular dystrophy in DMD mice is dependent on the presence of both utrophin and α7ß1 integrin, even when they are individually expressed at therapeutic levels. Furthermore, we found that association of sarcospan into laminin-binding complexes is dependent on utrophin and α7ß1 integrin.


Assuntos
Antígenos CD/metabolismo , Proteínas de Transporte/metabolismo , Cadeias alfa de Integrinas/metabolismo , Laminina/metabolismo , Proteínas de Membrana/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Proteínas de Neoplasias/metabolismo , Utrofina/metabolismo , Animais , Antígenos CD/genética , Proteínas de Transporte/genética , Feminino , Humanos , Cadeias alfa de Integrinas/genética , Integrinas/genética , Integrinas/metabolismo , Laminina/genética , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Proteínas de Neoplasias/genética , Ligação Proteica , Utrofina/genética
10.
Glycobiology ; 26(10): 1120-1132, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27236198

RESUMO

The neuromuscular junction (NMJ) is enriched with glycoproteins modified with N-acetylgalactosamine (GalNAc) residues, and four nominally GalNAc-specific plant lectins have historically been used to identify the NMJ and the utrophin-glycoprotein complex. However, little is known about the specific glycan epitopes on skeletal muscle that are bound by these lectins, the glycoproteins that bear these epitopes or how creation of these glycan epitopes is regulated. Here, we profile changes in cell surface glycosylation during muscle cell differentiation and identify distinct differences in the binding preferences of GalNAc-specific lectins, Wisteria floribunda agglutinin (WFA), Vicia villosa agglutinin (VVA), soybean agglutinin (SBA) and Dolichos biflorus agglutinin (DBA). While we find that all four GalNAc binding lectins specifically label the NMJ, each of the four lectins binds distinct sets of muscle glycoproteins; furthermore, none of the major adhesion complexes are required for binding of any of the four GalNAc-specific lectins. Analysis of glycosylation-related transcripts identified target glycosyltransferases and glycosidases that could potentially create GalNAc-containing epitopes; reducing expression of these transcripts by siRNA highlighted differences in lectin binding specificities. In addition, we found that complex N-glycans are required for binding of WFA and SBA to murine C2C12 myotubes and for WFA binding to wild-type skeletal muscle, but not for binding of VVA or DBA. These results demonstrate that muscle cell surface glycosylation is finely regulated during muscle differentiation in a domain- and acceptor-substrate-specific manner, suggesting that temporal- and site-specific glycosylation are important for skeletal muscle cell function.


Assuntos
Epitopos/imunologia , Glicocálix/metabolismo , Músculo Esquelético/metabolismo , Polissacarídeos/imunologia , Animais , Diferenciação Celular , Linhagem Celular , Galinhas , Glicocálix/química , Glicocálix/imunologia , Camundongos , Camundongos Knockout , Músculo Esquelético/química , Músculo Esquelético/citologia , Músculo Esquelético/imunologia
11.
Hum Mol Genet ; 21(20): 4378-93, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22798625

RESUMO

Sarcospan (SSPN) is a core component of the major adhesion complexes in skeletal muscle, the dystrophin- and utrophin (Utr)-glycoprotein complexes (DGC and UGC). We performed a rigorous analysis of SSPN-null mice and discovered that loss of SSPN decreased DGC and UGC abundance, leading to impaired laminin-binding activity and susceptibility to eccentric contraction-induced injury in skeletal muscle. We show that loss of SSPN increased levels of α7ß1 integrin. To genetically test whether integrin compensates for the loss of DGC and UGC function in SSPN-nulls, we generated mice lacking both SSPN and α7 integrin (DKO, double knockout). Muscle regeneration, sarcolemma integrity and fibrosis were exacerbated in DKO mice and were remarkably similar to muscle from Duchenne muscular dystrophy (DMD) patients, suggesting that secondary loss of integrin contributes significantly to pathogenesis. Expression of the DGC and UGC, laminin binding and Akt signaling were negatively impacted in DKO muscle, resulting in severely diminished specific force properties. We demonstrate that SSPN is a necessary component of dystrophin and Utr function and that SSPN modulation of integrin signaling is required for extracellular matrix attachment and muscle force development.


Assuntos
Antígenos CD/genética , Proteínas de Transporte/genética , Distrofina/genética , Cadeias alfa de Integrinas/genética , Proteínas de Membrana/genética , Músculo Esquelético/metabolismo , Proteínas de Neoplasias/genética , Fenótipo , Utrofina/genética , Animais , Antígenos CD/metabolismo , Proteínas de Transporte/metabolismo , Modelos Animais de Doenças , Feminino , Cadeias alfa de Integrinas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Proteínas de Neoplasias/metabolismo , Sarcolema/metabolismo
12.
Cell Rep ; 43(6): 114253, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38781074

RESUMO

Diabetic kidney disease (DKD), the most common cause of kidney failure, is a frequent complication of diabetes and obesity, and yet to date, treatments to halt its progression are lacking. We analyze kidney single-cell transcriptomic profiles from DKD patients and two DKD mouse models at multiple time points along disease progression-high-fat diet (HFD)-fed mice aged to 90-100 weeks and BTBR ob/ob mice (a genetic model)-and report an expanding population of macrophages with high expression of triggering receptor expressed on myeloid cells 2 (TREM2) in HFD-fed mice. TREM2high macrophages are enriched in obese and diabetic patients, in contrast to hypertensive patients or healthy controls in an independent validation cohort. Trem2 knockout mice on an HFD have worsening kidney filter damage and increased tubular epithelial cell injury, all signs of worsening DKD. Together, our studies suggest that strategies to enhance kidney TREM2high macrophages may provide therapeutic benefits for DKD.


Assuntos
Nefropatias Diabéticas , Dieta Hiperlipídica , Rim , Macrófagos , Glicoproteínas de Membrana , Camundongos Knockout , Obesidade , Receptores Imunológicos , Animais , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Macrófagos/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Obesidade/complicações , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Camundongos , Rim/patologia , Rim/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Feminino
13.
J Biol Chem ; 287(27): 22759-70, 2012 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-22570487

RESUMO

Duchenne muscular dystrophy is an X-linked disorder characterized by loss of dystrophin, a cytoskeletal protein that connects the actin cytoskeleton in skeletal muscle cells to extracellular matrix. Dystrophin binds to the cytoplasmic domain of the transmembrane glycoprotein ß-dystroglycan (ß-DG), which associates with cell surface α-dystroglycan (α-DG) that binds laminin in the extracellular matrix. ß-DG can also associate with utrophin, and this differential association correlates with specific glycosylation changes on α-DG. Genetic modification of α-DG glycosylation can promote utrophin binding and rescue dystrophic phenotypes in mouse dystrophy models. We used high throughput screening with the plant lectin Wisteria floribunda agglutinin (WFA) to identify compounds that altered muscle cell surface glycosylation, with the goal of finding compounds that increase abundance of α-DG and associated sarcolemmal glycoproteins, increase utrophin usage, and increase laminin binding. We identified one compound, lobeline, from the Prestwick library of Food and Drug Administration-approved compounds that fulfilled these criteria, increasing WFA binding to C2C12 cells and to primary muscle cells from wild type and mdx mice. WFA binding and enhancement by lobeline required complex N-glycans but not O-mannose glycans that bind laminin. However, inhibiting complex N-glycan processing reduced laminin binding to muscle cell glycoproteins, although O-mannosylation was intact. Glycan analysis demonstrated a general increase in N-glycans on lobeline-treated cells rather than specific alterations in cell surface glycosylation, consistent with increased abundance of multiple sarcolemmal glycoproteins. This demonstrates the feasibility of high throughput screening with plant lectins to identify compounds that alter muscle cell glycosylation and identifies a novel role for N-glycans in regulating muscle cell function.


Assuntos
Glicômica/métodos , Laminina/metabolismo , Mioblastos Esqueléticos/metabolismo , Polissacarídeos/metabolismo , Músculo Quadríceps/metabolismo , Sarcolema/metabolismo , Animais , Células Cultivadas , Glicômica/instrumentação , Glicosilação , Lobelina/farmacologia , Masculino , Manosiltransferases/genética , Manosiltransferases/metabolismo , Camundongos , Camundongos Endogâmicos mdx , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Proteínas Musculares/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/efeitos dos fármacos , Agonistas Nicotínicos/farmacologia , Lectinas de Plantas/farmacologia , Músculo Quadríceps/citologia , RNA Interferente Pequeno/genética , Receptores de N-Acetilglucosamina , Sarcolema/efeitos dos fármacos
14.
bioRxiv ; 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36865221

RESUMO

Cellular exposure to free fatty acids (FFA) is implicated in the pathogenesis of obesity-associated diseases. However, studies to date have assumed that a few select FFAs are representative of broad structural categories, and there are no scalable approaches to comprehensively assess the biological processes induced by exposure to diverse FFAs circulating in human plasma. Furthermore, assessing how these FFA- mediated processes interact with genetic risk for disease remains elusive. Here we report the design and implementation of FALCON (Fatty Acid Library for Comprehensive ONtologies) as an unbiased, scalable and multimodal interrogation of 61 structurally diverse FFAs. We identified a subset of lipotoxic monounsaturated fatty acids (MUFAs) with a distinct lipidomic profile associated with decreased membrane fluidity. Furthermore, we developed a new approach to prioritize genes that reflect the combined effects of exposure to harmful FFAs and genetic risk for type 2 diabetes (T2D). Importantly, we found that c-MAF inducing protein (CMIP) protects cells from exposure to FFAs by modulating Akt signaling and we validated the role of CMIP in human pancreatic beta cells. In sum, FALCON empowers the study of fundamental FFA biology and offers an integrative approach to identify much needed targets for diverse diseases associated with disordered FFA metabolism. Highlights: FALCON (Fatty Acid Library for Comprehensive ONtologies) enables multimodal profiling of 61 free fatty acids (FFAs) to reveal 5 FFA clusters with distinct biological effectsFALCON is applicable to many and diverse cell typesA subset of monounsaturated FAs (MUFAs) equally or more toxic than canonical lipotoxic saturated FAs (SFAs) leads to decreased membrane fluidityNew approach prioritizes genes that represent the combined effects of environmental (FFA) exposure and genetic risk for diseaseC-Maf inducing protein (CMIP) is identified as a suppressor of FFA-induced lipotoxicity via Akt-mediated signaling.

15.
Cell Metab ; 35(5): 887-905.e11, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37075753

RESUMO

Cellular exposure to free fatty acids (FFAs) is implicated in the pathogenesis of obesity-associated diseases. However, there are no scalable approaches to comprehensively assess the diverse FFAs circulating in human plasma. Furthermore, assessing how FFA-mediated processes interact with genetic risk for disease remains elusive. Here, we report the design and implementation of fatty acid library for comprehensive ontologies (FALCON), an unbiased, scalable, and multimodal interrogation of 61 structurally diverse FFAs. We identified a subset of lipotoxic monounsaturated fatty acids associated with decreased membrane fluidity. Furthermore, we prioritized genes that reflect the combined effects of harmful FFA exposure and genetic risk for type 2 diabetes (T2D). We found that c-MAF-inducing protein (CMIP) protects cells from FFA exposure by modulating Akt signaling. In sum, FALCON empowers the study of fundamental FFA biology and offers an integrative approach to identify much needed targets for diverse diseases associated with disordered FFA metabolism.


Assuntos
Diabetes Mellitus Tipo 2 , Ácidos Graxos não Esterificados , Humanos , Ácidos Graxos não Esterificados/metabolismo , Ácidos Graxos , Transdução de Sinais , Biologia
16.
iScience ; 25(4): 104097, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35372810

RESUMO

High-resolution spatial transcriptomics enables mapping of RNA expression directly from intact tissue sections; however, its utility for the elucidation of disease processes and therapeutically actionable pathways remains unexplored. We applied Slide-seqV2 to mouse and human kidneys, in healthy and distinct disease paradigms. First, we established the feasibility of Slide-seqV2 in tissue from nine distinct human kidneys, which revealed a cell neighborhood centered around a population of LYVE1+ macrophages. Second, in a mouse model of diabetic kidney disease, we detected changes in the cellular organization of the spatially restricted kidney filter and blood-flow-regulating apparatus. Third, in a mouse model of a toxic proteinopathy, we identified previously unknown, disease-specific cell neighborhoods centered around macrophages. In a spatially restricted subpopulation of epithelial cells, we discovered perturbations in 77 genes associated with the unfolded protein response. Our studies illustrate and experimentally validate the utility of Slide-seqV2 for the discovery of disease-specific cell neighborhoods.

17.
Science ; 376(6594): eabl4290, 2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35549429

RESUMO

Understanding gene function and regulation in homeostasis and disease requires knowledge of the cellular and tissue contexts in which genes are expressed. Here, we applied four single-nucleus RNA sequencing methods to eight diverse, archived, frozen tissue types from 16 donors and 25 samples, generating a cross-tissue atlas of 209,126 nuclei profiles, which we integrated across tissues, donors, and laboratory methods with a conditional variational autoencoder. Using the resulting cross-tissue atlas, we highlight shared and tissue-specific features of tissue-resident cell populations; identify cell types that might contribute to neuromuscular, metabolic, and immune components of monogenic diseases and the biological processes involved in their pathology; and determine cell types and gene modules that might underlie disease mechanisms for complex traits analyzed by genome-wide association studies.


Assuntos
Núcleo Celular , Doença , RNA-Seq , Biomarcadores , Núcleo Celular/genética , Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Especificidade de Órgãos , Fenótipo , RNA-Seq/métodos
18.
Front Physiol ; 12: 809346, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35069263

RESUMO

Spatial transcriptomic technologies capture genome-wide readouts across biological tissue space. Moreover, recent advances in this technology, including Slide-seqV2, have achieved spatial transcriptomic data collection at a near-single cell resolution. To-date, a repertoire of computational tools has been developed to discern cell type classes given the transcriptomic profiles of tissue coordinates. Upon applying these tools, we can explore the spatial patterns of distinct cell types and characterize how genes are spatially expressed within different cell type contexts. The kidney is one organ whose function relies upon spatially defined structures consisting of distinct cellular makeup. Thus, the application of Slide-seqV2 to kidney tissue has enabled us to elucidate spatially characteristic cellular and genetic profiles at a scale that remains largely unexplored. Here, we review spatial transcriptomic technologies, as well as computational approaches for cell type mapping and spatial cell type and transcriptomic characterizations. We take kidney tissue as an example to demonstrate how the technologies are applied, while considering the nuances of this architecturally complex tissue.

19.
Nat Biotechnol ; 39(3): 313-319, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33288904

RESUMO

Measurement of the location of molecules in tissues is essential for understanding tissue formation and function. Previously, we developed Slide-seq, a technology that enables transcriptome-wide detection of RNAs with a spatial resolution of 10 µm. Here we report Slide-seqV2, which combines improvements in library generation, bead synthesis and array indexing to reach an RNA capture efficiency ~50% that of single-cell RNA-seq data (~10-fold greater than Slide-seq), approaching the detection efficiency of droplet-based single-cell RNA-seq techniques. First, we leverage the detection efficiency of Slide-seqV2 to identify dendritically localized mRNAs in neurons of the mouse hippocampus. Second, we integrate the spatial information of Slide-seqV2 data with single-cell trajectory analysis tools to characterize the spatiotemporal development of the mouse neocortex, identifying underlying genetic programs that were poorly sampled with Slide-seq. The combination of near-cellular resolution and high transcript detection efficiency makes Slide-seqV2 useful across many experimental contexts.


Assuntos
Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Transcriptoma , Animais , Humanos , Camundongos , RNA Mensageiro/genética
20.
J Clin Invest ; 131(5)2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444290

RESUMO

Mutations affecting mitochondrial coenzyme Q (CoQ) biosynthesis lead to kidney failure due to selective loss of podocytes, essential cells of the kidney filter. Curiously, neighboring tubular epithelial cells are spared early in disease despite higher mitochondrial content. We sought to illuminate noncanonical, cell-specific roles for CoQ, independently of the electron transport chain (ETC). Here, we demonstrate that CoQ depletion caused by Pdss2 enzyme deficiency in podocytes results in perturbations in polyunsaturated fatty acid (PUFA) metabolism and the Braf/Mapk pathway rather than ETC dysfunction. Single-nucleus RNA-Seq from kidneys of Pdss2kd/kd mice with nephrotic syndrome and global CoQ deficiency identified a podocyte-specific perturbation of the Braf/Mapk pathway. Treatment with GDC-0879, a Braf/Mapk-targeting compound, ameliorated kidney disease in Pdss2kd/kd mice. Mechanistic studies in Pdss2-depleted podocytes revealed a previously unknown perturbation in PUFA metabolism that was confirmed in vivo. Gpx4, an enzyme that protects against PUFA-mediated lipid peroxidation, was elevated in disease and restored after GDC-0879 treatment. We demonstrate broader human disease relevance by uncovering patterns of GPX4 and Braf/Mapk pathway gene expression in tissue from patients with kidney diseases. Our studies reveal ETC-independent roles for CoQ in podocytes and point to Braf/Mapk as a candidate pathway for the treatment of kidney diseases.


Assuntos
Ataxia/metabolismo , Indenos/farmacologia , Nefropatias/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Doenças Mitocondriais/metabolismo , Debilidade Muscular/metabolismo , Podócitos/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Pirazóis/farmacologia , Ubiquinona/deficiência , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Animais , Ataxia/tratamento farmacológico , Ataxia/genética , Ataxia/patologia , Sistemas de Liberação de Medicamentos , Células HEK293 , Humanos , Nefropatias/tratamento farmacológico , Nefropatias/genética , Nefropatias/patologia , Peroxidação de Lipídeos/genética , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/genética , Doenças Mitocondriais/patologia , Debilidade Muscular/tratamento farmacológico , Debilidade Muscular/genética , Debilidade Muscular/patologia , Podócitos/patologia , Proteínas Proto-Oncogênicas B-raf/genética , RNA-Seq , Ubiquinona/genética , Ubiquinona/metabolismo
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