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1.
Nature ; 604(7905): 316-322, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35388222

RESUMO

The brain consists of thousands of neuronal types that are generated by stem cells producing different neuronal types as they age. In Drosophila, this temporal patterning is driven by the successive expression of temporal transcription factors (tTFs)1-6. Here we used single-cell mRNA sequencing to identify the complete series of tTFs that specify most Drosophila optic lobe neurons. We verify that tTFs regulate the progression of the series by activating the next tTF(s) and repressing the previous one(s), and also identify more complex mechanisms of regulation. Moreover, we establish the temporal window of origin and birth order of each neuronal type in the medulla and provide evidence that these tTFs are sufficient to explain the generation of all of the neuronal diversity in this brain region. Finally, we describe the first steps of neuronal differentiation and show that these steps are conserved in humans. We find that terminal differentiation genes, such as neurotransmitter-related genes, are present as transcripts, but not as proteins, in immature larval neurons. This comprehensive analysis of a temporal series of tTFs in the optic lobe offers mechanistic insights into how tTF series are regulated, and how they can lead to the generation of a complete set of neurons.


Assuntos
Proteínas de Drosophila , Drosophila melanogaster , Regulação da Expressão Gênica no Desenvolvimento , Lobo Óptico de Animais não Mamíferos , Fatores de Transcrição , Visão Ocular , Percepção Visual , Animais , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Lobo Óptico de Animais não Mamíferos/citologia , RNA-Seq , Análise de Célula Única , Fatores de Transcrição/metabolismo
2.
Nature ; 589(7840): 88-95, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33149298

RESUMO

Deciphering how neuronal diversity is established and maintained requires a detailed knowledge of neuronal gene expression throughout development. In contrast to mammalian brains1,2, the large neuronal diversity of the Drosophila optic lobe3 and its connectome4-6 are almost completely characterized. However, a molecular characterization of this neuronal diversity, particularly during development, has been lacking. Here we present insights into brain development through a nearly complete description of the transcriptomic diversity of the optic lobes of Drosophila. We acquired the transcriptome of 275,000 single cells at adult and at five pupal stages, and built a machine-learning framework to assign them to almost 200 cell types at all time points during development. We discovered two large neuronal populations that wrap neuropils during development but die just before adulthood, as well as neuronal subtypes that partition dorsal and ventral visual circuits by differential Wnt signalling throughout development. Moreover, we show that the transcriptomes of neurons that are of the same type but are produced days apart become synchronized shortly after their production. During synaptogenesis we also resolved neuronal subtypes that, although differing greatly in morphology and connectivity, converge to indistinguishable transcriptomic profiles in adults. Our datasets almost completely account for the known neuronal diversity of the Drosophila optic lobes, and serve as a paradigm to understand brain development across species.


Assuntos
Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Neurônios/classificação , Neurônios/metabolismo , Lobo Óptico de Animais não Mamíferos/citologia , Lobo Óptico de Animais não Mamíferos/crescimento & desenvolvimento , Anatomia Artística , Animais , Apoptose , Atlas como Assunto , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Neurônios/citologia , Pupa/citologia , Pupa/crescimento & desenvolvimento , Análise de Célula Única , Sinapses/metabolismo , Transcriptoma/genética , Vias Visuais , Via de Sinalização Wnt
3.
Mol Cell ; 75(2): 394-407.e5, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31227230

RESUMO

The structural diversity of glycans on cells-the glycome-is vast and complex to decipher. Glycan arrays display oligosaccharides and are used to report glycan hapten binding epitopes. Glycan arrays are limited resources and present saccharides without the context of other glycans and glycoconjugates. We used maps of glycosylation pathways to generate a library of isogenic HEK293 cells with combinatorially engineered glycosylation capacities designed to display and dissect the genetic, biosynthetic, and structural basis for glycan binding in a natural context. The cell-based glycan array is self-renewable and reports glycosyltransferase genes required (or blocking) for interactions through logical sequential biosynthetic steps, which is predictive of structural glycan features involved and provides instructions for synthesis, recombinant production, and genetic dissection strategies. Broad utility of the cell-based glycan array is demonstrated, and we uncover higher order binding of microbial adhesins to clustered patches of O-glycans organized by their presentation on proteins.


Assuntos
Engenharia Genética , Redes e Vias Metabólicas/genética , Polissacarídeos/química , Proteínas/genética , Epitopos/genética , Epitopos/imunologia , Glicosilação , Glicosiltransferases/genética , Células HEK293 , Humanos , Oligossacarídeos/genética , Polissacarídeos/classificação , Polissacarídeos/genética , Polissacarídeos/imunologia , Proteínas/imunologia
4.
Proc Natl Acad Sci U S A ; 121(24): e2400378121, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38830096

RESUMO

Epitranscriptomic RNA modifications have emerged as important regulators of the fate and function of viral RNAs. One prominent modification, the cytidine methylation 5-methylcytidine (m5C), is found on the RNA of HIV-1, where m5C enhances the translation of HIV-1 RNA. However, whether m5C functionally enhances the RNA of other pathogenic viruses remains elusive. Here, we surveyed a panel of commonly found RNA modifications on the RNA of hepatitis B virus (HBV) and found that HBV RNA is enriched with m5C as well as ten other modifications, at stoichiometries much higher than host messenger RNA (mRNA). Intriguingly, m5C is mostly found on the epsilon hairpin, an RNA element required for viral RNA encapsidation and reverse transcription, with these m5C mainly deposited by the cellular methyltransferase NSUN2. Loss of m5C from HBV RNA due to NSUN2 depletion resulted in a partial decrease in viral core protein (HBc) production, accompanied by a near-complete loss of the reverse transcribed viral DNA. Similarly, mutations introduced to remove the methylated cytidines resulted in a loss of HBc production and reverse transcription. Furthermore, pharmacological disruption of m5C deposition led to a significant decrease in HBV replication. Thus, our data indicate m5C methylations as a critical mediator of the epsilon elements' function in HBV virion production and reverse transcription, suggesting the therapeutic potential of targeting the m5C methyltransfer process on HBV epsilon as an antiviral strategy.


Assuntos
Citidina , Vírus da Hepatite B , RNA Viral , Transcrição Reversa , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Vírus da Hepatite B/fisiologia , RNA Viral/genética , RNA Viral/metabolismo , Citidina/análogos & derivados , Citidina/metabolismo , Citidina/genética , Humanos , Transcrição Reversa/genética , Metilação , Replicação Viral/genética , Epigênese Genética , Vírion/metabolismo , Vírion/genética , Transcriptoma
5.
Mol Cell ; 70(4): 602-613.e3, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29775578

RESUMO

The proteolysis-assisted protein quality control system guards the proteome from potentially detrimental aberrant proteins. How miscellaneous defective proteins are specifically eliminated and which molecular characteristics direct them for removal are fundamental questions. We reveal a mechanism, DesCEND (destruction via C-end degrons), by which CRL2 ubiquitin ligase uses interchangeable substrate receptors to recognize the unusual C termini of abnormal proteins (i.e., C-end degrons). C-end degrons are mostly less than ten residues in length and comprise a few indispensable residues along with some rather degenerate ones. The C-terminal end position is essential for C-end degron function. Truncated selenoproteins generated by translation errors and the USP1 N-terminal fragment from post-translational cleavage are eliminated by DesCEND. DesCEND also targets full-length proteins with naturally occurring C-end degrons. The C-end degron in DesCEND echoes the N-end degron in the N-end rule pathway, highlighting the dominance of protein "ends" as indicators for protein elimination.


Assuntos
Processamento de Proteína Pós-Traducional , Receptores de Citocinas/metabolismo , Selenoproteínas/metabolismo , Proteases Específicas de Ubiquitina/metabolismo , Ubiquitina/metabolismo , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Domínios Proteicos , Proteólise , Receptores de Citocinas/genética , Proteases Específicas de Ubiquitina/genética
6.
Nucleic Acids Res ; 52(10): 5676-5697, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38520407

RESUMO

Replication stress converts the stalled forks into reversed forks, which is an important protection mechanism to prevent fork degradation and collapse into poisonous DNA double-strand breaks (DSBs). Paradoxically, the mechanism also acts in cancer cells to contribute to chemoresistance against various DNA-damaging agents. PARP1 binds to and is activated by stalled forks to facilitate fork reversal. Aprataxin and polynucleotide kinase/phosphatase-like factor (APLF) binds to PARP1 through the poly(ADP-ribose) zinc finger (PBZ) domain and is known to be involved in non-homologous end joining (NHEJ). Here, we identify a novel function of APLF involved in interstrand DNA crosslink (ICL) repair and fork protection. We demonstrate that PARP1 activity facilitates the APLF recruitment to stalled forks, enabling the FANCD2 recruitment to stalled forks. The depletion of APLF sensitizes cells to cisplatin, impairs ICL repair, reduces the FANCD2 recruitment to stalled forks, and results in nascent DNA degradation by MRE11 nucleases. Additionally, cisplatin-resistant cancer cells show high levels of APLF and homologous recombination-related gene expression. The depletion of APLF sensitizes cells to cisplatin and results in fork instability. Our results reveal the novel function of APLF to facilitate ICL repair and fork protection, thereby contributing to cisplatin-resistant phenotypes of cancer cells.


Assuntos
Cisplatino , Reparo do DNA , Replicação do DNA , DNA Liase (Sítios Apurínicos ou Apirimidínicos) , Resistencia a Medicamentos Antineoplásicos , Poli(ADP-Ribose) Polimerase-1 , Humanos , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , DNA/metabolismo , DNA/genética , Quebras de DNA de Cadeia Dupla , Dano ao DNA , Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Proteínas de Ligação a Poli-ADP-Ribose
7.
Proc Natl Acad Sci U S A ; 120(32): e2307451120, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37523539

RESUMO

Cell-type-specific tools facilitate the identification and functional characterization of the distinct cell types that form the complexity of neuronal circuits. A large collection of existing genetic tools in Drosophila relies on enhancer activity to label different subsets of cells and has been extremely useful in analyzing functional circuits in adults. However, these enhancer-based GAL4 lines often do not reflect the expression of nearby gene(s) as they only represent a small portion of the full gene regulatory elements. While genetic intersectional techniques such as the split-GAL4 system further improve cell-type-specificity, it requires significant time and resources to screen through combinations of enhancer expression patterns. Here, we use existing developmental single-cell RNA sequencing (scRNAseq) datasets to select gene pairs for split-GAL4 and provide a highly efficient and predictive pipeline (scMarco) to generate cell-type-specific split-GAL4 lines at any time during development, based on the native gene regulatory elements. These gene-specific split-GAL4 lines can be generated from a large collection of coding intronic MiMIC/CRIMIC lines or by CRISPR knock-in. We use the developing Drosophila visual system as a model to demonstrate the high predictive power of scRNAseq-guided gene-specific split-GAL4 lines in targeting known cell types, annotating clusters in scRNAseq datasets as well as in identifying novel cell types. Lastly, the gene-specific split-GAL4 lines are broadly applicable to any other Drosophila tissue. Our work opens new avenues for generating cell-type-specific tools for the targeted manipulation of distinct cell types throughout development and represents a valuable resource for the Drosophila community.


Assuntos
Proteínas de Drosophila , Fatores de Transcrição , Animais , Fatores de Transcrição/metabolismo , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Técnicas Genéticas , Análise de Sequência de RNA , Drosophila melanogaster/metabolismo
8.
Lancet ; 403(10425): 450-458, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38219767

RESUMO

BACKGROUND: The combination of rectally administered indomethacin and placement of a prophylactic pancreatic stent is recommended to prevent pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) in high-risk patients. Preliminary evidence suggests that the use of indomethacin might eliminate or substantially reduce the need for stent placement, a technically complex, costly, and potentially harmful intervention. METHODS: In this randomised, non-inferiority trial conducted at 20 referral centres in the USA and Canada, patients (aged ≥18 years) at high risk for post-ERCP pancreatitis were randomly assigned (1:1) to receive rectal indomethacin alone or the combination of indomethacin plus a prophylactic pancreatic stent. Patients, treating clinicians, and outcomes assessors were masked to study group assignment. The primary outcome was post-ERCP pancreatitis. To declare non-inferiority, the upper bound of the two-sided 95% CI for the difference in post-ERCP pancreatitis (indomethacin alone minus indomethacin plus stent) would have to be less than 5% (non-inferiority margin) in both the intention-to-treat and per-protocol populations. This trial is registered with ClinicalTrials.gov (NCT02476279), and is complete. FINDINGS: Between Sept 17, 2015, and Jan 25, 2023, a total of 1950 patients were randomly assigned. Post-ERCP pancreatitis occurred in 145 (14·9%) of 975 patients in the indomethacin alone group and in 110 (11·3%) of 975 in the indomethacin plus stent group (risk difference 3·6%; 95% CI 0·6-6·6; p=0·18 for non-inferiority). A post-hoc intention-to-treat analysis of the risk difference between groups showed that indomethacin alone was inferior to the combination of indomethacin plus prophylactic stent (p=0·011). The relative benefit of stent placement was generally consistent across study subgroups but appeared more prominent among patients at highest risk for pancreatitis. Safety outcomes (serious adverse events, intensive care unit admission, and hospital length of stay) did not differ between groups. INTERPRETATION: For preventing post-ERCP pancreatitis in high-risk patients, a strategy of indomethacin alone was not as effective as a strategy of indomethacin plus prophylactic pancreatic stent placement. These results support prophylactic pancreatic stent placement in addition to rectal indomethacin administration in high-risk patients, in accordance with clinical practice guidelines. FUNDING: US National Institutes of Health.


Assuntos
Indometacina , Pancreatite , Adolescente , Adulto , Humanos , Administração Retal , Anti-Inflamatórios não Esteroides/uso terapêutico , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Indometacina/uso terapêutico , Pancreatite/epidemiologia , Pancreatite/etiologia , Pancreatite/prevenção & controle , Fatores de Risco , Stents
9.
Nat Mater ; 23(6): 782-789, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38491147

RESUMO

Coupling of spin and charge currents to structural chirality in non-magnetic materials, known as chirality-induced spin selectivity, is promising for application in spintronic devices at room temperature. Although the chirality-induced spin selectivity effect has been identified in various chiral materials, its Onsager reciprocal process, the inverse chirality-induced spin selectivity effect, remains unexplored. Here we report the observation of the inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. Using spin-pumping techniques, the inverse chirality-induced spin selectivity effect enables quantification of the magnitude of the longitudinal spin-to-charge conversion driven by chirality-induced spin selectivity in different chiral polymers. By widely tuning conductivities and supramolecular chiral structures via a printing method, we found a very long spin relaxation time of up to several nanoseconds parallel to the chiral axis. Our demonstration of the inverse chirality-induced spin selectivity effect suggests possibilities for elucidating the puzzling interplay between spin and chirality, and opens a route for spintronic applications using printable chiral assemblies.

10.
PLoS Pathog ; 19(12): e1011891, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38109416

RESUMO

Trichomonas vaginalis is a prevalent causative agent that causes trichomoniasis leading to uropathogenic inflammation in the host. The crucial role of the actin cytoskeleton in T. vaginalis cytoadherence has been established but the associated signaling has not been fully elucidated. The present study revealed that the T. vaginalis second messenger PIP2 is located in the recurrent flagellum of the less adherent isolate and is more abundant around the cell membrane of the adherent isolates. The T. vaginalis phosphatidylinositol-4-phosphate 5-kinase (TvPI4P5K) with conserved activity phosphorylating PI(4)P to PI(4, 5)P2 was highly expressed in the adherent isolate and partially colocalized with PIP2 on the plasma membrane but with discrete punctate signals in the cytoplasm. Plasma membrane PIP2 degradation by phospholipase C (PLC)-dependent pathway concomitant with increasing intracellular calcium during flagellate-amoeboid morphogenesis. This could be inhibited by Edelfosine or BAPTA simultaneously repressing parasite actin assembly, morphogenesis, and cytoadherence with inhibitory effects similar to the iron-depleted parasite, supporting the significance of PIP2 and iron in T. vaginalis colonization. Intriguingly, iron is required for the optimal expression and cell membrane trafficking of TvPI4P5K for in situ PIP2 production, which was diminished in the iron-depleted parasites. TvPI4P5K-mediated PIP2 signaling may coordinate with iron to modulate T. vaginalis contact-dependent cytolysis to influence host cell viability. These observations provide novel insights into T. vaginalis cytopathogenesis during the host-parasite interaction.


Assuntos
Parasitos , Trichomonas vaginalis , Animais , Cálcio/metabolismo , Citoesqueleto de Actina , Ferro/metabolismo
11.
PLoS Biol ; 20(7): e3001680, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35797414

RESUMO

Early career researchers (ECRs) are important stakeholders leading efforts to catalyze systemic change in research culture and practice. Here, we summarize the outputs from a virtual unconventional conference (unconference), which brought together 54 invited experts from 20 countries with extensive experience in ECR initiatives designed to improve the culture and practice of science. Together, we drafted 2 sets of recommendations for (1) ECRs directly involved in initiatives or activities to change research culture and practice; and (2) stakeholders who wish to support ECRs in these efforts. Importantly, these points apply to ECRs working to promote change on a systemic level, not only those improving aspects of their own work. In both sets of recommendations, we underline the importance of incentivizing and providing time and resources for systems-level science improvement activities, including ECRs in organizational decision-making processes, and working to dismantle structural barriers to participation for marginalized groups. We further highlight obstacles that ECRs face when working to promote reform, as well as proposed solutions and examples of current best practices. The abstract and recommendations for stakeholders are available in Dutch, German, Greek (abstract only), Italian, Japanese, Polish, Portuguese, Spanish, and Serbian.


Assuntos
Pesquisadores , Relatório de Pesquisa , Humanos , Poder Psicológico
12.
J Immunol ; 211(4): 648-657, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37405700

RESUMO

Drugs are needed to protect against the neutrophil-derived histones responsible for endothelial injury in acute inflammatory conditions such as trauma and sepsis. Heparin and other polyanions can neutralize histones but challenges with dosing or side effects such as bleeding limit clinical application. In this study, we demonstrate that suramin, a widely available polyanionic drug, completely neutralizes the toxic effects of individual histones, but not citrullinated histones from neutrophil extracellular traps. The sulfate groups on suramin form stable electrostatic interactions with hydrogen bonds in the histone octamer with a dissociation constant of 250 nM. In cultured endothelial cells (Ea.Hy926), histone-induced thrombin generation was significantly decreased by suramin. In isolated murine blood vessels, suramin abolished aberrant endothelial cell calcium signals and rescued impaired endothelial-dependent vasodilation caused by histones. Suramin significantly decreased pulmonary endothelial cell ICAM-1 expression and neutrophil recruitment caused by infusion of sublethal doses of histones in vivo. Suramin also prevented histone-induced lung endothelial cell cytotoxicity in vitro and lung edema, intra-alveolar hemorrhage, and mortality in mice receiving a lethal dose of histones. Protection of vascular endothelial function from histone-induced damage is a novel mechanism of action for suramin with therapeutic implications for conditions characterized by elevated histone levels.


Assuntos
Histonas , Suramina , Camundongos , Animais , Histonas/metabolismo , Suramina/farmacologia , Células Endoteliais/metabolismo , Endotélio/metabolismo , Hemorragia
13.
PLoS Genet ; 18(12): e1010545, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36512630

RESUMO

Replication fork reversal which restrains DNA replication progression is an important protective mechanism in response to replication stress. PARP1 is recruited to stalled forks to restrain DNA replication. However, PARP1 has no helicase activity, and the mechanism through which PARP1 participates in DNA replication restraint remains unclear. Here, we found novel protein-protein interactions between PARP1 and DNA translocases, including HLTF, SHPRH, ZRANB3, and SMARCAL1, with HLTF showing the strongest interaction among these DNA translocases. Although HLTF and SHPRH share structural and functional similarity, it remains unclear whether SHPRH contains DNA translocase activity. We further identified the ability of SHPRH to restrain DNA replication upon replication stress, indicating that SHPRH itself could be a DNA translocase or a helper to facilitate DNA translocation. Although hydroxyurea (HU) and MMS induce different types of replication stress, they both induce common DNA replication restraint mechanisms independent of intra-S phase activation. Our results suggest that the PARP1 facilitates DNA translocase recruitment to damaged forks, preventing fork collapse and facilitating DNA repair.


Assuntos
Proteínas de Ligação a DNA , Fatores de Transcrição , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Reparo do DNA/genética , Replicação do DNA/genética , DNA/genética , Dano ao DNA/genética
14.
J Neurosci ; 43(48): 8259-8270, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-37821229

RESUMO

The recent increase in the use of nicotine products by teenagers has revealed an urgent need to better understand the impact of nicotine on the adolescent brain. Here, we sought to examine the actions of extracellular ATP as a neurotransmitter and to investigate whether ATP and nicotinic signaling interact during adolescence. With the GRABATP (G-protein-coupled receptor activation-based ATP sensor), we first demonstrated that nicotine induces extracellular ATP release in the medial habenula, a brain region involved in nicotine aversion and withdrawal. Using patch-clamp electrophysiology, we then demonstrated that activation of the ATP receptors P2X or P2Y1 increases the neuronal firing of cholinergic neurons. Surprisingly, contrasting interactive effects were observed with nicotine exposure. For the P2X receptor, activation had no observable effect on acute nicotine-mediated activity, but during abstinence after 10 d of nicotine exposure, coexposure to nicotine and the P2X agonist potentiated neuronal activity in female, but not male, neurons. For P2Y1 signaling, a potentiated effect of the agonist and nicotine was observed with acute exposure, but not following extended nicotine exposure. These data reveal a complex interactive effect between nicotinic and ATP signaling in the adolescent brain and provide mechanistic insights into extracellular ATP signaling with sex-specific alterations of neuronal responses based on prior drug exposure.SIGNIFICANCE STATEMENT In these studies, it was discovered that nicotine induces extracellular ATP release in the medial habenula and subsequent activation of the ATP purinergic receptors increases habenular cholinergic neuronal firing in the adolescent brain. Interestingly, following extended nicotine exposure, nicotine was found to alter the interplay between purinergic and nicotinic signaling in a sex-specific manner. Together, these studies provide a novel understanding for the role of extracellular ATP in mediating habenular activity and reveal how nicotine exposure during adolescence alters these signaling mechanisms, which has important implications given the high incidence of e-cigarette/vape use by youth.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Habenula , Receptores Purinérgicos P2 , Masculino , Adolescente , Feminino , Humanos , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Transmissão Sináptica , Neurônios Colinérgicos , Receptores Purinérgicos P2/fisiologia , Trifosfato de Adenosina/farmacologia
15.
Cancer ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38985843

RESUMO

BACKGROUND: This was a single-arm, phase 2 clinical trial of Bavarian Nordic (BN)-Brachyury vaccine plus radiotherapy (RT) designed to determine the objective response rate (ORR), progression-free survival (PFS), and safety of the combination in chordoma. METHODS: A total of 29 adult patients with advanced chordoma were treated with two subcutaneous priming vaccine doses of modified vaccinia Ankara-Bavarian Nordic (MVA-BN)-Brachyury and one vaccine dose of fowlpox virus (FPV)-Brachyury before RT. After RT, booster vaccinations were given with FPV-Brachyury every 4 weeks for 4 doses, then every 12 weeks (week 110). A minimum RT dose of >8 Gy in one fraction for each target was required. Response was evaluated by modified Response Evaluation Criteria in Solid Tumors 1.1 (mRECIST), where only radiated lesions were considered targets, and by standard RECIST 1.1 in a subset of patients. RESULTS: Two of 26 evaluable patients experienced durable partial response (PR) (ORR of 7.7%; 90% confidence interval [CI], 2.6-20.8]) by mRECIST 1.1. A total of 21 patients (80.8%; 90% CI, 65.4-90.3) had stable disease, and three patients (11.5%; 90% CI, 4.7-25.6) had progressive disease as best response per mRECIST 1.1. Median PFS was not reached during the study. CONCLUSIONS: This trial confirms the safety of BN-Brachyury and RT. Although the study did not meet the predefined study goal of four responses in 29 patients, we did observe two PRs and a PFS of greater than 2 years. For a vaccine-based study in chordoma, an ultra-rare disease where response rates are low, a randomized study or novel trial designs may be required to confirm activity.

16.
J Hepatol ; 80(6): 858-867, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38336347

RESUMO

BACKGROUND & AIMS: HBV expresses more than 10 spliced RNAs from the viral pregenomic RNA, but their functions remain elusive and controversial. To address the function of HBV spliced RNAs, we generated splicing-deficient HBV mutants and conducted experiments to assess the impact of these mutants on HBV infection. METHODS: HepG2-NTCP cells, human hepatocyte chimeric FRG mice (hu-FRG mice), and serum from patients with chronic hepatitis B were used for experiments on HBV infection. Additionally, SHifter assays and cryo-electron microscopy were performed. RESULTS: We found the infectivity of splicing-deficient HBV was decreased 100-1,000-fold compared with that of wild-type HBV in hu-FRG mice. Another mutant, A487C, which loses the most abundant spliced RNA (SP1), also exhibits severely impaired infectivity. SP1 hypothetically encodes a novel protein HBcSP1 (HBc-Cys) that lacks the C-terminal cysteine from full-length HBc. In the SHifter assay, HBcSP1 was detected in wild-type viral particles at a ratio of about 20-100% vs. conventional HBc, as well as in the serum of patients with chronic hepatitis B, but not in A487C particles. When infection was conducted with a shorter incubation time of 4-8 h at lower PEG concentrations in HepG2-NTCP cells, the entry of the A487C mutant was significantly slower. SP1 cDNA complementation of the A487C mutant succeeded in rescuing its infectivity in hu-FRG mice and HepG2-NTCP cells. Moreover, cryo-electron microscopy revealed a disulfide bond between HBc cysteine 183 and 48 in the HBc intradimer of the A487C capsid, leading to a locked conformation that disfavored viral entry in contrast to the wild-type capsid. CONCLUSIONS: Prior studies unveiled the potential integration of the HBc-Cys protein into the HBV capsid. We confirmed the proposal and validated its identity and function during infection. IMPACT AND IMPLICATIONS: HBV SP1 RNA encodes a novel HBc protein (HBcSP1) that lacks the C-terminal cysteine from conventional HBc (HBc-Cys). HBcSP1 was detected in cell culture-derived HBV and confirmed in patients with chronic infection by both immunological and chemical modification assays at 10-50% of capsid. The splicing-deficient mutant HBV (A487C) impaired infectivity in human hepatocyte chimeric mice and viral entry in the HepG2-NTCP cell line. Furthermore, these deficiencies of the splicing-deficient mutant could be rescued by complementation with the SP1-encoded protein HBcSP1. We confirmed and validated the identity and function of HBcSP1 during infection, building on the current model of HBV particles.


Assuntos
Vírus da Hepatite B , Hepatite B Crônica , Humanos , Animais , Vírus da Hepatite B/genética , Camundongos , Células Hep G2 , Hepatite B Crônica/virologia , Splicing de RNA , Mutação , RNA Viral/genética , RNA Viral/metabolismo , Microscopia Crioeletrônica
17.
Apoptosis ; 29(5-6): 620-634, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38281282

RESUMO

Maleic acid (MA) induces renal tubular cell dysfunction directed to acute kidney injury (AKI). AKI is an increasing global health burden due to its association with mortality and morbidity. However, targeted therapy for AKI is lacking. Previously, we determined mitochondrial-associated proteins are MA-induced AKI affinity proteins. We hypothesized that mitochondrial dysfunction in tubular epithelial cells plays a critical role in AKI. In vivo and in vitro systems have been used to test this hypothesis. For the in vivo model, C57BL/6 mice were intraperitoneally injected with 400 mg/kg body weight MA. For the in vitro model, HK-2 human proximal tubular epithelial cells were treated with 2 mM or 5 mM MA for 24 h. AKI can be induced by administration of MA. In the mice injected with MA, the levels of blood urea nitrogen (BUN) and creatinine in the sera were significantly increased (p < 0.005). From the pathological analysis, MA-induced AKI aggravated renal tubular injuries, increased kidney injury molecule-1 (KIM-1) expression and caused renal tubular cell apoptosis. At the cellular level, mitochondrial dysfunction was found with increasing mitochondrial reactive oxygen species (ROS) (p < 0.001), uncoupled mitochondrial respiration with decreasing electron transfer system activity (p < 0.001), and decreasing ATP production (p < 0.05). Under transmission electron microscope (TEM) examination, the cristae formation of mitochondria was defective in MA-induced AKI. To unveil the potential target in mitochondria, gene expression analysis revealed a significantly lower level of ATPase6 (p < 0.001). Renal mitochondrial protein levels of ATP subunits 5A1 and 5C1 (p < 0.05) were significantly decreased, as confirmed by protein analysis. Our study demonstrated that dysfunction of mitochondria resulting from altered expression of ATP synthase in renal tubular cells is associated with MA-induced AKI. This finding provides a potential novel target to develop new strategies for better prevention and treatment of MA-induced AKI.


Assuntos
Injúria Renal Aguda , Apoptose , Maleatos , Camundongos Endogâmicos C57BL , Mitocôndrias , ATPases Mitocondriais Próton-Translocadoras , Animais , Humanos , Masculino , Camundongos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Injúria Renal Aguda/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Túbulos Renais Proximais/patologia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , ATPases Mitocondriais Próton-Translocadoras/genética , Espécies Reativas de Oxigênio/metabolismo
18.
Hum Genet ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38985322

RESUMO

The prevalence of overweight and obesity is increasing, leading to metabolic-associated fatty liver disease (MAFLD) characterized by excessive accumulation of liver fat and a risk of developing hepatocellular carcinoma (HCC). The driver gene mutations may play the roles of passengers that occur in single 'hotspots' and can promote tumorigenesis from benign to malignant lesions. We investigated the impact of high body weight and BMI on HCC survival using The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset. To explore the effects of obesity-related gene mutations on HCC, we collected driver mutation genes in 34 TCGA patients with BMI ≥ 27 and 23 TCGA patients with BMI < 27. The digital PCR performing the PBMC samples for the variant rate by clinical cohort of 96 NAFLD patients. Our analysis showed that obesity leads to significantly worse survival outcomes in HCC. Using cbioportal, we identified 414 driver mutation genes in patients with obesity and 127 driver mutation genes in non-obese patients. Functional analysis showed that obese-related genes significantly enriched the regulated lipid and insulin pathways in HCC. The insulin secretion pathway in patients with obesity HCC-specific survival identified ABCC8 and PRKCB as significant genes (p < 0.001). It revealed significant differences in gene mutation and gene expression profiles compared to non-obese patients. The digital PCR test ABCC8 variants were detected in PBMC samples and caused a 14.5% variant rate, significantly higher than that of non-obese NAFLD patients. The study findings showed that the gene ABCC8 was a patient with the obesity-related gene in NAFLD, which provides the probability that ABCC8 mutation contributes to the pre-cancer lesion biomarker for HCC.

19.
Gastroenterology ; 165(5): 1249-1261.e5, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37549753

RESUMO

BACKGROUND & AIMS: Endoscopic ultrasound-guided choledochoduodenostomy with a lumen-apposing metal stent (EUS-CDS) is a promising modality for management of malignant distal biliary obstruction (MDBO) with potential for better stent patency. We compared its outcomes with endoscopic retrograde cholangiopancreatography with metal stenting (ERCP-M). METHODS: In this multicenter randomized controlled trial, we recruited patients with MDBO secondary to borderline resectable, locally advanced, or unresectable peri-ampullary cancers across 10 Canadian institutions and 1 French institution. This was a superiority trial with a noninferiority assessment of technical success. Patients were randomized to EUS-CDS or ERCP-M. The primary end point was the rate of stent dysfunction at 1 year, considering competing risks of death, clinical failure, and surgical resection. Analyses were performed according to intention-to-treat principles. RESULTS: From February 2019 to February 2022, 144 patients were recruited; 73 were randomized to EUS-CDS and 71 were randomized to ERCP-M. The mean (SD) procedure time was 14.0 (11.4) minutes for EUS-CDS and 23.1 (15.6) minutes for ERCP-M (P < .01); 40% of the former was performed without fluoroscopy. Technical success was achieved in 90.4% (95% CI, 81.5% to 95.3%) of EUS-CDS and 83.1% (95% CI, 72.7% to 90.1%) of ERCP-M with a risk difference of 7.3% (95% CI, -4.0% to 18.8%) indicating noninferiority. Stent dysfunction occurred in 9.6% vs 9.9% of EUS-CDS and ERCP-M cases, respectively (P = .96). No differences in adverse events, pancreaticoduodenectomy and oncologic outcomes, or quality of life were noted. CONCLUSIONS: Although not superior in stent function, EUS-CDS is an efficient and safe alternative to ERCP-M in patients with MDBO. These findings provide evidence for greater adoption of EUS-CDS in clinical practice as a complementary and exchangeable first-line modality to ERCP in patients with MDBO. CLINICALTRIALS: gov, Number: NCT03870386.

20.
Am J Gastroenterol ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38775310

RESUMO

INTRODUCTION: Concerns regarding bleeding remain in cold snare polypectomy (CSP) for small pedunculated (0-Ip) polyps. The aim of this study was to compare the risk of CSP and hot snare polypectomy (HSP) for such lesions. METHODS: Data on 0-Ip colorectal polyps ≤10 mm were extracted from a large, pragmatic, randomized trial. Immediate postpolypectomy bleeding (IPPB), defined as the perioperative use of a clip for bleeding, was evaluated through polyp-level analysis. Delayed postpolypectomy bleeding (DPPB), defined as bleeding occurring within 2 weeks postoperatively, was assessed at the patient-level among patients whose polyps were all ≤10 mm, including at least one 0-Ip polyp. RESULTS: A total of 647 0-Ip polyps (CSP: 306; HSP: 341) were included for IPPB analysis and 386 patients (CSP: 192; HSP: 194) for DPPB analysis. CSP was associated with a higher incidence of IPPB (10.8% vs 3.2%, P < 0.001) but no adverse clinical events. The procedure time of all polypectomies was shorter for CSP than for HSP (123.0 ± 117.8 vs 166.0 ± 237.7 seconds, P = 0.003), while the procedure time of polypectomies with IPPB were similar (249.8 ± 140.2 vs 227.4 ± 125.9 seconds, P = 0.64). DPPB was observed in 3 patients (1.5%) in the HSP group, including one patient (0.5%) with severe bleeding, but not in the CSP group. DISCUSSION: Despite CSP being associated with more IPPB events, it could be timely treated without adverse outcomes. Notably, no delayed bleeding occurred in the CSP group. Our findings support the use of CSP for 0-Ip polyps ≤ 10 mm.

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