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1.
Nat Immunol ; 24(8): 1358-1369, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37365386

RESUMO

Following infection or vaccination, activated B cells at extrafollicular sites or within germinal centers (GCs) undergo vigorous clonal proliferation. Proliferating lymphocytes have been shown to undertake lactate dehydrogenase A (LDHA)-dependent aerobic glycolysis; however, the specific role of this metabolic pathway in a B cell transitioning from a naïve to a highly proliferative, activated state remains poorly defined. Here, we deleted LDHA in a stage-specific and cell-specific manner. We find that ablation of LDHA in a naïve B cell did not profoundly affect its ability to undergo a bacterial lipopolysaccharide-induced extrafollicular B cell response. On the other hand, LDHA-deleted naïve B cells had a severe defect in their capacities to form GCs and mount GC-dependent antibody responses. In addition, loss of LDHA in T cells severely compromised B cell-dependent immune responses. Strikingly, when LDHA was deleted in activated, as opposed to naïve, B cells, there were only minimal effects on the GC reaction and in the generation of high-affinity antibodies. These findings strongly suggest that naïve and activated B cells have distinct metabolic requirements that are further regulated by niche and cellular interactions.


Assuntos
Linfócitos B , Centro Germinativo , Linfócitos T , Ativação Linfocitária , Comunicação Celular
2.
Nat Immunol ; 24(6): 1020-1035, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37127830

RESUMO

While regulatory T (Treg) cells are traditionally viewed as professional suppressors of antigen presenting cells and effector T cells in both autoimmunity and cancer, recent findings of distinct Treg cell functions in tissue maintenance suggest that their regulatory purview extends to a wider range of cells and is broader than previously assumed. To elucidate tumoral Treg cell 'connectivity' to diverse tumor-supporting accessory cell types, we explored immediate early changes in their single-cell transcriptomes upon punctual Treg cell depletion in experimental lung cancer and injury-induced inflammation. Before any notable T cell activation and inflammation, fibroblasts, endothelial and myeloid cells exhibited pronounced changes in their gene expression in both cancer and injury settings. Factor analysis revealed shared Treg cell-dependent gene programs, foremost, prominent upregulation of VEGF and CCR2 signaling-related genes upon Treg cell deprivation in either setting, as well as in Treg cell-poor versus Treg cell-rich human lung adenocarcinomas. Accordingly, punctual Treg cell depletion combined with short-term VEGF blockade showed markedly improved control of PD-1 blockade-resistant lung adenocarcinoma progression in mice compared to the corresponding monotherapies, highlighting a promising factor-based querying approach to elucidating new rational combination treatments of solid organ cancers.


Assuntos
Neoplasias , Linfócitos T Reguladores , Animais , Camundongos , Humanos , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Microambiente Tumoral , Neoplasias/metabolismo
3.
Nat Immunol ; 22(9): 1163-1174, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34426690

RESUMO

The immunosuppressive function of regulatory T (Treg) cells is dependent on continuous expression of the transcription factor Foxp3. Foxp3 loss of function or induced ablation of Treg cells results in a fatal autoimmune disease featuring all known types of inflammatory responses with every manifestation stemming from Treg cell paucity, highlighting a vital function of Treg cells in preventing fatal autoimmune inflammation. However, a major question remains whether Treg cells can persist and effectively exert their function in a disease state, where a broad spectrum of inflammatory mediators can either inactivate Treg cells or render innate and adaptive pro-inflammatory effector cells insensitive to suppression. By reinstating Foxp3 protein expression and suppressor function in cells expressing a reversible Foxp3 null allele in severely diseased mice, we found that the resulting single pool of rescued Treg cells normalized immune activation, quelled severe tissue inflammation, reversed fatal autoimmune disease and provided long-term protection against them. Thus, Treg cells are functional in settings of established broad-spectrum systemic inflammation and are capable of affording sustained reset of immune homeostasis.


Assuntos
Doenças Autoimunes/imunologia , Autoimunidade/imunologia , Fatores de Transcrição Forkhead/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoimunidade/genética , Diferenciação Celular/imunologia , Feminino , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica/genética , Homeostase/imunologia , Mediadores da Inflamação/metabolismo , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Síndrome de Resposta Inflamatória Sistêmica/patologia
4.
Immunity ; 55(7): 1173-1184.e7, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35700740

RESUMO

Regulatory T (Treg) cells expressing the transcription factor Foxp3 are an essential suppressive T cell lineage of dual origin: Foxp3 induction in thymocytes and mature CD4+ T cells gives rise to thymic (tTreg) and peripheral (pTreg) Treg cells, respectively. While tTreg cells suppress autoimmunity, pTreg cells enforce tolerance to food and commensal microbiota. However, the role of Foxp3 in pTreg cells and the mechanisms supporting their differentiation remain poorly understood. Here, we used genetic tracing to identify microbiota-induced pTreg cells and found that many of their distinguishing features were Foxp3 independent. Lineage-committed, microbiota-dependent pTreg-like cells persisted in the colon in the absence of Foxp3. While Foxp3 was critical for the suppression of a Th17 cell program, colitis, and mastocytosis, pTreg cells suppressed colonic effector T cell expansion in a Foxp3-independent manner. Thus, Foxp3 and the tolerogenic signals that precede and promote its expression independently confer distinct facets of pTreg functionality.


Assuntos
Fatores de Transcrição Forkhead , Linfócitos T Reguladores , Fatores de Transcrição Forkhead/metabolismo , Tolerância Imunológica , Células Th17/metabolismo , Timócitos/metabolismo
5.
Immunity ; 54(5): 931-946.e11, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33838102

RESUMO

Activation of the STAT5 transcription factor downstream of the Interleukin-2 receptor (IL-2R) induces expression of Foxp3, a critical step in the differentiation of regulatory T (Treg) cells. Due to the pleiotropic effects of IL-2R signaling, it is unclear how STAT5 acts directly on the Foxp3 locus to promote its expression. Here, we report that IL-2 - STAT5 signaling converged on an enhancer (CNS0) during Foxp3 induction. CNS0 facilitated the IL-2 dependent CD25+Foxp3- precursor to Treg cell transition in the thymus. Its deficiency resulted in impaired Treg cell generation in neonates, which was partially mitigated with age. While the thymic Treg cell paucity caused by CNS0 deficiency did not result in autoimmunity on its own, it exacerbated autoimmune manifestations caused by disruption of the Aire gene. Thus, CNS0 enhancer activity ensures robust Treg cell differentiation early in postnatal life and cooperatively with other tolerance mechanisms minimizes autoimmunity.


Assuntos
Linhagem da Célula/imunologia , Fatores de Transcrição Forkhead/imunologia , Tolerância Imunológica/imunologia , Interleucina-2/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoimunidade/imunologia , Diferenciação Celular/imunologia , Elementos Facilitadores Genéticos/imunologia , Feminino , Humanos , Subunidade alfa de Receptor de Interleucina-2/imunologia , Masculino , Camundongos , Receptores de Interleucina-2/imunologia , Fator de Transcrição STAT5/imunologia , Transdução de Sinais/imunologia
6.
Nature ; 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39478218

RESUMO

The Greenland ice sheet (GrIS) is at present the largest single contributor to global-mass-induced sea-level rise, primarily because of Arctic amplification on an increasingly warmer Earth1-5. However, the processes of englacial water accumulation, storage and ultimate release remain poorly constrained. Here we show that a noticeable amount of the summertime meltwater mass is temporally buffered along the entire GrIS periphery, peaking in July and gradually reducing thereafter. Our results arise from quantifying the spatiotemporal behaviour of the total mass of water leaving the GrIS by analysing bedrock elastic deformation measured by Global Navigation Satellite System (GNSS) stations. The buffered meltwater causes a subsidence of the bedrock close to GNSS stations of at most approximately 5 mm during the melt season. Regionally, the duration of meltwater storage ranges from 4.5 weeks in the southeast to 9 weeks elsewhere. We also show that the meltwater runoff modelled from regional climate models may contain systematic errors, requiring further scaling of up to about 20% for the warmest years. These results reveal a high potential for GNSS data to constrain poorly known hydrological processes in Greenland, forming the basis for improved projections of future GrIS melt behaviour and the associated sea-level rise6.

7.
Immunity ; 53(5): 971-984.e5, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33176163

RESUMO

Regulatory T (Treg) cell identity is defined by the lineage-specifying transcription factor (TF) Foxp3. Here we examined mechanisms of Foxp3 function by leveraging naturally occurring genetic variation in wild-derived inbred mice, which enables the identification of DNA sequence motifs driving epigenetic features. Chromatin accessibility, TF binding, and gene expression patterns in resting and activated subsets of Treg cells, conventional CD4 T cells, and cells expressing a Foxp3 reporter null allele revealed that the majority of Foxp3-dependent changes occurred at sites not bound by Foxp3. Chromatin accessibility of these indirect Foxp3 targets depended on the presence of DNA binding motifs for other TFs, including TCF1. Foxp3 expression correlated with decreased TCF1 and reduced accessibility of TCF1-bound chromatin regions. Deleting one copy of the Tcf7 gene recapitulated Foxp3-dependent negative regulation of chromatin accessibility. Thus, Foxp3 defines Treg cell identity in a largely indirect manner by fine-tuning the activity of other major chromatin remodeling TFs such as TCF1.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Doenças Autoimunes/etiologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Autoimunidade/genética , Sítios de Ligação , Montagem e Desmontagem da Cromatina , Modelos Animais de Doenças , Epigênese Genética , Feminino , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica , Imuno-Histoquímica , Masculino , Camundongos , Motivos de Nucleotídeos , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Ligação Proteica , Transativadores/metabolismo
8.
Nature ; 610(7933): 752-760, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36070798

RESUMO

Establishing and maintaining tolerance to self-antigens or innocuous foreign antigens is vital for the preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing autoimmune regulator (AIRE) have a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development1-4. Within weeks of birth, a separate wave of Treg cell differentiation occurs in the periphery upon exposure to antigens derived from the diet and commensal microbiota5-8, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells have not been identified. Here we describe the identification of a class of RORγt+ antigen-presenting cells called Thetis cells, with transcriptional features of both mTECs and dendritic cells, comprising four major sub-groups (TC I-TC IV). We uncover a developmental wave of Thetis cells within intestinal lymph nodes during a critical window in early life, coinciding with the wave of pTreg cell differentiation. Whereas TC I and TC III expressed the signature mTEC nuclear factor AIRE, TC IV lacked AIRE expression and was enriched for molecules required for pTreg generation, including the TGF-ß-activating integrin αvß8. Loss of either major histocompatibility complex class II (MHCII) or ITGB8 by Thetis cells led to a profound impairment in intestinal pTreg differentiation, with ensuing colitis. By contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical dendritic cells was neither sufficient nor required for pTreg generation, further implicating TC IV as the tolerogenic RORγt+ antigen-presenting cell with an essential function in early life. Our studies reveal parallel pathways for the establishment of tolerance to self and foreign antigens in the thymus and periphery, respectively, marked by the involvement of shared cellular and transcriptional programmes.


Assuntos
Células Apresentadoras de Antígenos , Células Dendríticas , Células Epiteliais , Microbioma Gastrointestinal , Tolerância Imunológica , Linfócitos T Reguladores , Timo , Diferenciação Celular , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Microbioma Gastrointestinal/imunologia , Imunidade Inata , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Timo/citologia , Timo/imunologia , Fator de Crescimento Transformador beta/imunologia , Células Apresentadoras de Antígenos/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia , Linfonodos/imunologia
9.
Proc Natl Acad Sci U S A ; 121(6): e2304619121, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38289962

RESUMO

Resistance to neoadjuvant chemotherapy leads to poor prognosis of locally advanced rectal cancer (LARC), representing an unmet clinical need that demands further exploration of therapeutic strategies to improve clinical outcomes. Here, we identified a noncanonical role of RB1 for modulating chromatin activity that contributes to oxaliplatin resistance in colorectal cancer (CRC). We demonstrate that oxaliplatin induces RB1 phosphorylation, which is associated with the resistance to neoadjuvant oxaliplatin-based chemotherapy in LARC. Inhibition of RB1 phosphorylation by CDK4/6 inhibitor results in vulnerability to oxaliplatin in both intrinsic and acquired chemoresistant CRC. Mechanistically, we show that RB1 modulates chromatin activity through the TEAD4/HDAC1 complex to epigenetically suppress the expression of DNA repair genes. Antagonizing RB1 phosphorylation through CDK4/6 inhibition enforces RB1/TEAD4/HDAC1 repressor activity, leading to DNA repair defects, thus sensitizing oxaliplatin treatment in LARC. Our study identifies a RB1 function in regulating chromatin activity through TEAD4/HDAC1. It also provides the combination of CDK4/6 inhibitor with oxaliplatin as a potential synthetic lethality strategy to mitigate oxaliplatin resistance in LARC, whereby phosphorylated RB1/TEAD4 can serve as potential biomarkers to guide the patient stratification.


Assuntos
Terapia Neoadjuvante , Neoplasias Retais , Humanos , Oxaliplatina/farmacologia , Terapia Neoadjuvante/métodos , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/genética , Quimiorradioterapia/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cromatina , Resultado do Tratamento , Fatores de Transcrição de Domínio TEA , Ubiquitina-Proteína Ligases , Proteínas de Ligação a Retinoblastoma
10.
Plant J ; 119(3): 1353-1368, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38829920

RESUMO

Cucumber plants are highly susceptible to the hemibiotroph oomycete Phytophthora melonis. However, the mechanism of resistance to cucumber blight remains poorly understood. Here, we demonstrated that cucumber plants with impairment in the biosynthesis of brassinosteroids (BRs) or gibberellins (GAs) were more susceptible to P. melonis. By contrast, increasing levels of endogenous BRs or exogenously application of 24-epibrassinolide enhanced the resistance of cucumber plants against P. melonis. Furthermore, we found that both knockout and overexpression of the BR biosynthesis gene CYP85A1 reduced the endogenous GA3 content compared with that of wild-type plants under the condition of inoculation with P. melonis, and the enhancement of disease resistance conferred by BR was inhibited in plants with silencing of the GA biosynthetic gene GA20ox1 or KAO. Together, these findings suggest that GA homeostasis is an essential factor mediating BRs-induced disease resistance. Moreover, BZR6, a key regulator of BR signaling, was found to physically interact with GA20ox1, thereby suppressing its transcription. Silencing of BZR6 promoted endogenous GA biosynthesis and compromised GA-mediated resistance. These findings reveal multifaceted crosstalk between BR and GA in response to pathogen infection, which can provide a new approach for genetically controlling P. melonis damage in cucumber production.


Assuntos
Brassinosteroides , Cucumis sativus , Resistência à Doença , Giberelinas , Phytophthora , Doenças das Plantas , Phytophthora/fisiologia , Brassinosteroides/metabolismo , Cucumis sativus/microbiologia , Cucumis sativus/genética , Cucumis sativus/metabolismo , Cucumis sativus/parasitologia , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/imunologia , Giberelinas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais
11.
PLoS Pathog ; 19(12): e1011844, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38060615

RESUMO

Virologic suppression with antiretroviral therapy (ART) has significantly improved health outcomes for people living with HIV, yet challenges related to chronic inflammation in the central nervous system (CNS)-known as Neuro-HIV- persist. As primary targets for HIV-1 with the ability to survey and populate the CNS and interact with myeloid cells to co-ordinate neuroinflammation, CD4 T cells are pivotal in Neuro-HIV. Despite their importance, our understanding of CD4 T cell distribution in virus-targeted CNS tissues, their response to infection, and potential recovery following initiation of ART remain limited. To address these gaps, we studied ten SIVmac251-infected rhesus macaques using an ART regimen simulating suboptimal adherence. We evaluated four macaques during the acute phase pre-ART and six during the chronic phase. Our data revealed that HIV target CCR5+ CD4 T cells inhabit both the brain parenchyma and adjacent CNS tissues, encompassing choroid plexus stroma, dura mater, and the skull bone marrow. Aligning with the known susceptibility of CCR5+ CD4 T cells to viral infection and their presence within the CNS, high levels of viral RNA were detected in the brain parenchyma and its border tissues during acute SIV infection. Single-cell RNA sequencing of CD45+ cells from the brain revealed colocalization of viral transcripts within CD4 clusters and significant activation of antiviral molecules and specific effector programs within T cells, indicating CNS CD4 T cell engagement during infection. Acute infection led to marked imbalance in the CNS CD4/CD8 ratio which persisted into the chronic phase. These observations underscore the functional involvement of CD4 T cells within the CNS during SIV infection, enhancing our understanding of their role in establishing CNS viral presence. Our findings offer insights for potential T cell-focused interventions while underscoring the challenges in eradicating HIV from the CNS, particularly in the context of sub-optimal ART.


Assuntos
Infecções por HIV , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Humanos , Linfócitos T CD4-Positivos , Vírus da Imunodeficiência Símia/fisiologia , Macaca mulatta , Sistema Nervoso Central , Carga Viral
12.
Nature ; 572(7771): 665-669, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31435014

RESUMO

Intestinal commensal bacteria can inhibit dense colonization of the gut by vancomycin-resistant Enterococcus faecium (VRE), a leading cause of hospital-acquired infections1,2. A four-strained consortium of commensal bacteria that contains Blautia producta BPSCSK can reverse antibiotic-induced susceptibility to VRE infection3. Here we show that BPSCSK reduces growth of VRE by secreting a lantibiotic that is similar to the nisin-A produced by Lactococcus lactis. Although the growth of VRE is inhibited by BPSCSK and L. lactis in vitro, only BPSCSK colonizes the colon and reduces VRE density in vivo. In comparison to nisin-A, the BPSCSK lantibiotic has reduced activity against intestinal commensal bacteria. In patients at high risk of VRE infection, high abundance of the lantibiotic gene is associated with reduced density of E. faecium. In germ-free mice transplanted with patient-derived faeces, resistance to VRE colonization correlates with abundance of the lantibiotic gene. Lantibiotic-producing commensal strains of the gastrointestinal tract reduce colonization by VRE and represent potential probiotic agents to re-establish resistance to VRE.


Assuntos
Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Enterococcus faecium/efeitos dos fármacos , Lactococcus lactis/metabolismo , Probióticos , Resistência a Vancomicina/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Animais , Antibacterianos/biossíntese , Antibacterianos/isolamento & purificação , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bacteriocinas/genética , Bacteriocinas/isolamento & purificação , Enterococcus faecium/crescimento & desenvolvimento , Enterococcus faecium/isolamento & purificação , Fezes/microbiologia , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Vida Livre de Germes , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Humanos , Lactococcus lactis/química , Lactococcus lactis/crescimento & desenvolvimento , Lactococcus lactis/fisiologia , Camundongos , Testes de Sensibilidade Microbiana , Microbiota/genética , Nisina/química , Nisina/farmacologia , Simbiose/efeitos dos fármacos , Vancomicina/farmacologia , Enterococos Resistentes à Vancomicina/crescimento & desenvolvimento , Enterococos Resistentes à Vancomicina/isolamento & purificação
13.
J Infect Dis ; 229(6): 1702-1710, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38213276

RESUMO

Definitive data demonstrating the utility of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) for treating immunocompromised patients remains elusive. To better understand the mechanism of action of CCP, we studied viral replication and disease progression in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected hamsters treated with CCP obtained from recovered COVID-19 patients that were also vaccinated with an mRNA vaccine, hereafter referred to as Vaxplas. Vaxplas transiently enhanced disease severity and lung pathology in hamsters treated near peak viral replication due to immune complex and activated complement deposition in pulmonary endothelium, and recruitment of M1 proinflammatory macrophages into the lung parenchyma. However, aside from one report, transient enhanced disease has not been reported in CCP recipient patients, and the transient enhanced disease in Vaxplas hamsters may have been due to mismatched species IgG-FcR interactions, infusion timing, or other experimental factors. Despite transient disease enhancement, Vaxplas dramatically reduced virus replication in lungs and improved infection outcome in SARS-CoV-2-infected hamsters.


Assuntos
Anticorpos Antivirais , Soroterapia para COVID-19 , Vacinas contra COVID-19 , COVID-19 , Imunização Passiva , Pulmão , SARS-CoV-2 , Replicação Viral , Animais , COVID-19/imunologia , COVID-19/virologia , SARS-CoV-2/imunologia , Cricetinae , Pulmão/virologia , Pulmão/imunologia , Pulmão/patologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Humanos , Mesocricetus , Modelos Animais de Doenças , Masculino , Feminino
14.
J Neurosci ; 43(24): 4405-4417, 2023 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-37188512

RESUMO

Although NG2 is known to be selectively expressed in oligodendrocyte precursor cells (OPCs) for many years, its expressional regulation and functional involvement in oligodendrocyte differentiation have remained elusive. Here, we report that the surface-bound NG2 proteoglycan can physically bind to PDGF-AA and enhances PDGF receptor alpha (PDGFRα) activation of downstream signaling. During differentiation stage, NG2 protein is cleaved by A disintegrin and metalloproteinase with thrombospondin motifs type 4 (Adamts4), which is highly upregulated in differentiating OPCs but gradually downregulated in mature myelinating oligodendrocytes. Genetic ablation of Adamts4 gene impedes NG2 proteolysis, leading to elevated PDGFRα signaling but impaired oligodendrocyte differentiation and axonal myelination in both sexes of mice. Moreover, Adamts4 deficiency also lessens myelin repair in adult brain tissue following Lysophosphatidylcholine-induced demyelination. Thus, Adamts4 could be a potential therapeutic target for enhancing oligodendrocyte differentiation and axonal remyelination in demyelinating diseases.SIGNIFICANCE STATEMENT NG2 is selectively expressed in OPCs and downregulated during differentiation stage. To date, the molecular mechanism underlying the progressive removal of NG2 surface proteoglycan in differentiating OPCs has been unknown. In this study, we demonstrate that ADAMTS4 released by differentiating OPCs cleaves surface NG2 proteoglycan, attenuates PDGFRα signaling, and accelerates oligodendrocyte differentiation. In addition, our study also suggests ADAMTS4 as a potential therapeutic target for promoting myelin recovery in demyelinating diseases.


Assuntos
Doenças Desmielinizantes , Remielinização , Masculino , Feminino , Camundongos , Animais , Receptor alfa de Fator de Crescimento Derivado de Plaquetas , Bainha de Mielina/metabolismo , Proteoglicanas/genética , Oligodendroglia/metabolismo , Diferenciação Celular/fisiologia , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/metabolismo
15.
BMC Genomics ; 25(1): 958, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39402483

RESUMO

BACKGROUND: In the domain of forensic science, the application of kinship identification and mixture deconvolution techniques are of critical importance, providing robust scientific evidence for the resolution of complex cases. Microhaplotypes, as the emerging class of genetic markers, have been widely studied in forensics due to their high polymorphisms and excellent stability. RESULTS AND DISCUSSION: In this research, a novel and high-efficient panel integrating 33 microhaplotype loci along with a sex-determining locus was developed by the next generation sequencing technology. In addition, we also assessed its forensic utility and delved into its capacity for kinship analysis and mixture deconvolution. The average effective number of alleles (Ae) of the 33 microhaplotype loci in the Guizhou Han population was 6.06, and the Ae values of 30 loci were greater than 5. The cumulative power of discrimination and cumulative power of exclusion values of the novel panel in the Guizhou Han population were 1-5.6 × 10- 43 and 1-1.6 × 10- 15, respectively. In the simulated kinship analysis, the panel could effectively distinguish between parent-child, full-sibling, half-sibling, grandfather-grandson, aunt-nephew and unrelated individuals, but uncertainty rates clearly increased when distinguishing between first cousins and unrelated individuals. For the mixtures, the novel panel had demonstrated excellent performance in estimating the number of contributors of mixtures with 1 to 5 contributors in combination with the machine learning methods. CONCLUSIONS: In summary, we have developed a small and high-efficient panel for forensic genetics, which could provide novel insights into forensic complex kinships testing and mixture deconvolution.


Assuntos
Genética Forense , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Genética Forense/métodos , Alelos , Linhagem , Polimorfismo de Nucleotídeo Único
16.
Neuroimage ; 297: 120701, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38914210

RESUMO

Due to a high degree of symptom overlap in the early stages, with movement disorders predominating, Parkinson's disease (PD) and multiple system atrophy (MSA) may exhibit a similar decline in motor areas, yet they differ in their spread throughout the brain, ultimately resulting in two distinct diseases. Drawing upon neuroimaging analyses and altered motor cortex excitability, potential diffusion mechanisms were delved into, and comparisons of correlations across distinct disease groups were conducted in a bid to uncover significant pathological disparities. We recruited thirty-five PD, thirty-seven MSA, and twenty-eight matched controls to conduct clinical assessments, electromyographic recording, and magnetic resonance imaging scanning during the "on medication" state. Patients with neurodegeneration displayed a widespread decrease in electrophysiology in bilateral M1. Brain function in early PD was still in the self-compensatory phase and there was no significant change. MSA patients demonstrated an increase in intra-hemispheric function coupled with a decrease in diffusivity, indicating a reduction in the spread of neural signals. The level of resting motor threshold in healthy aged showed broad correlations with both clinical manifestations and brain circuits related to left M1, which was absent in disease states. Besides, ICF exhibited distinct correlations with functional connections between right M1 and left middle temporal gyrus in all groups. The present study identified subtle differences in the functioning of PD and MSA related to bilateral M1. By combining clinical information, cortical excitability, and neuroimaging intuitively, we attempt to bring light on the potential mechanisms that may underlie the development of neurodegenerative disease.


Assuntos
Atrofia de Múltiplos Sistemas , Doença de Parkinson , Humanos , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Atrofia de Múltiplos Sistemas/fisiopatologia , Masculino , Feminino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/fisiopatologia , Idoso , Imageamento por Ressonância Magnética/métodos , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiopatologia , Eletromiografia , Neuroimagem/métodos
17.
J Am Chem Soc ; 146(31): 21677-21688, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39042557

RESUMO

Achieving high guest loading and multiguest-binding capacity holds crucial significance for advancement in separation, catalysis, and drug delivery with synthetic receptors; however, it remains a challenging bottleneck in characterization of high-stoichiometry guest-binding events. Herein, we describe a large-sized coordination cage (MOC-70-Zn8Pd6) possessing 12 peripheral pockets capable of accommodating multiple guests and a high-resolution electrospray ionization mass spectrometry (HR-ESI-MS)-based method to understand the solution host-guest chemistry. A diverse range of bulky guests, varying from drug molecules to rigid fullerenes as well as flexible host molecules of crown ethers and calixarenes, could be loaded into open pockets with high capacities. Notably, these hollow cage pockets provide multisites to capture different guests, showing heteroguest coloading behavior to capture binary, ternary, or even quaternary guests. Moreover, a pair of commercially applied drugs for the combination therapy of chronic lymphocytic leukemia (CLL) has been tested, highlighting its potential in multidrug delivery for combined treatment.


Assuntos
Espectrometria de Massas por Ionização por Electrospray , Éteres de Coroa/química , Calixarenos/química , Paládio/química , Zinco/química , Fulerenos/química , Estrutura Molecular
18.
J Am Chem Soc ; 146(29): 20414-20424, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38982611

RESUMO

The structural dynamics of artificial assemblies, in aspects such as molecular recognition and structural transformation, provide us with a blueprint to achieve bioinspired applications. Here, we describe the assembly of redox-switchable chiral metal-organic cages Λ8/Δ8-[Pd6(CoIIL3)8]28+ and Λ8/Δ8-[Pd6(CoIIIL3)8]36+. These isomeric cages demonstrate an on-off chirality logic gate controlled by their chemical and stereostructural dynamics tunable through redox transitions between the labile CoII-state and static CoIII-state with a distinct Cotton effect. The transition between different states is enabled by a reversible redox process and chiral recognition originating in the tris-chelate Co-centers. All cages in two states are thoroughly characterized by NMR, ESI-MS, CV, CD, and X-ray crystallographic analysis, which clarify their redox-switching behaviors upon chemical reduction/oxidation. The stereochemical lability of the CoII-center endows the Λ8/Δ8-CoII-cages with efficient chiral-induction by enantiomeric guests, leading to enantiomeric isomerization to switch between Λ8/Δ8-CoII-cages, which can be stabilized by oxidation to their chemically inert forms of Λ8/Δ8-CoIII-cages. Kinetic studies reveal that the isomerization rate of the Δ8-CoIII-cage is at least an order of magnitude slower than that of the Δ8-CoII-cage even at an elevated temperature, while its activation energy is 16 kcal mol-1 higher than that of the CoII-cage.

19.
J Neurophysiol ; 132(3): 979-990, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39110517

RESUMO

5-Hydroxytryptamine (5-HT) plays a substantial role in mitigating depression and anxiety. However, the potential effects of 5-HT against posttraumatic stress disorder (PTSD) and its underlying mechanisms remain unclear. Elevated plus maze test evaluates anxiety-related behaviors, and the open field test is used to assess overall activity levels and anxiety. Inflammatory cytokine levels were determined using ELISA. The levels of 5-HT and dopamine were measured using HPLC. mRNA and protein levels were examined by PCR and Western blot, respectively. Rats exposed to single prolonged stress (SPS) exhibited typical PTSD-like phenotypes, with decreased levels of 5-HT in the hippocampus and significant reductions in its downstream targets, brain-derived neurotrophic factor (BDNF) and TrkB. In addition, it was discovered that the autophagy signaling pathway might be involved in regulating hippocampal BDNF in rats exposed to SPS. Subsequent treatment with an intracerebral injection of sh-SERT significantly inhibited anxiety and cognitive dysfunction in rats. Moreover, sh-SERT treatment was observed to substantially reverse the increase in autophagy signaling protein expression and consequently improve the expression of BDNF and TrkB proteins, which had been reduced. The current study demonstrates that sh-SERT exhibits significant anti-PTSD effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.NEW & NOTEWORTHY The study demonstrated that sh-SERT exhibits significant anti-posttraumatic stress disorder (PTSD) effects, potentially mediated in part through the reduction of cellular autophagy to enhance hippocampal synaptic plasticity.


Assuntos
Autofagia , Fator Neurotrófico Derivado do Encéfalo , Hipocampo , Plasticidade Neuronal , Ratos Sprague-Dawley , Serotonina , Transtornos de Estresse Pós-Traumáticos , Animais , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/metabolismo , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Masculino , Serotonina/metabolismo , Ratos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ansiedade/tratamento farmacológico , Receptor trkB/metabolismo , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Modelos Animais de Doenças
20.
Small ; : e2404552, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39106240

RESUMO

Oxygen evolution reaction is the essential anodic reaction for water splitting. Designing tunable electronic structures to overcome its slow kinetics is an effective strategy. Herein, the molecular ammonium iron sulfate dodecahydrate is employed as the precursor to synthesize the C, N, S triatomic co-doped Fe(Al)OOH on Ni foam (C,N,S-Fe(Al)OOH-NF) with asymmetric electronic structure. Both in situ oxygen vacancies and their special electronic configuration enable the electron transfer between the d-p orbitals and get the increase of OER activity. Density functional theory calculation further indicates the effect of electronic structure on catalytic activity and stability at the oxygen vacancies. In alkaline solution, the catalyst C,N,S-Fe(Al)OOH-NF shows good catalytic activity and stability for water splitting. For OER, the overpotential of 10 mA cm-2 is 264 mV, the tafel slope is 46.4 mV dec-1, the HER overpotential of 10 mA cm-2 is 188 mV, the tafel slope is 59.3 mV dec-1. The stability of the catalyst can maintain ≈100 h. This work has extraordinary implications for understanding the mechanistic relationship between electronic structure and catalytic activity for designing friendly metal (oxy)hydroxide catalysts.

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