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1.
Mol Cell ; 83(21): 3755-3757, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37922867

RESUMO

We talk to authors Yuzhi Wang, Conner Traugot, and Mingyi Xie about their paper "N6-methyladenosine in 7SK small nuclear RNA underlies RNA polymerase II transcription regulation" (this issue of Molecular Cell), their path to research science, and the interesting findings that keep bringing them back to the bench.


Assuntos
Regulação da Expressão Gênica , Fator B de Elongação Transcricional Positiva , Fator B de Elongação Transcricional Positiva/genética , RNA Nuclear Pequeno/genética , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Transcrição Gênica
2.
Mol Cell ; 83(21): 3818-3834.e7, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37820733

RESUMO

N6-methyladenosine (m6A) modifications play crucial roles in RNA metabolism. How m6A regulates RNA polymerase II (RNA Pol II) transcription remains unclear. We find that 7SK small nuclear RNA (snRNA), a regulator of RNA Pol II promoter-proximal pausing, is highly m6A-modified in non-small cell lung cancer (NSCLC) cells. In A549 cells, we identified eight m6A sites on 7SK and discovered methyltransferase-like 3 (METTL3) and alkB homolog 5 (ALKBH5) as the responsible writer and eraser. When the m6A-7SK is specifically erased by a dCasRx-ALKBH5 fusion protein, A549 cell growth is attenuated due to reduction of RNA Pol II transcription. Mechanistically, removal of m6A leads to 7SK structural rearrangements that facilitate sequestration of the positive transcription elongation factor b (P-TEFb) complex, which results in reduction of serine 2 phosphorylation (Ser2P) in the RNA Pol II C-terminal domain and accumulation of RNA Pol II in the promoter-proximal region. Taken together, we uncover that m6A modifications of a non-coding RNA regulate RNA Pol II transcription and NSCLC tumorigenesis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Fator B de Elongação Transcricional Positiva/genética , Neoplasias Pulmonares/genética , RNA Nuclear Pequeno/genética , Transcrição Gênica , Células HeLa , Metiltransferases/genética , Metiltransferases/metabolismo
3.
Mol Cell ; 83(12): 2003-2019.e6, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37257451

RESUMO

Regulation of RNA substrate selectivity of m6A demethylase ALKBH5 remains elusive. Here, we identify RNA-binding motif protein 33 (RBM33) as a previously unrecognized m6A-binding protein that plays a critical role in ALKBH5-mediated mRNA m6A demethylation of a subset of mRNA transcripts by forming a complex with ALKBH5. RBM33 recruits ALKBH5 to its m6A-marked substrate and activates ALKBH5 demethylase activity through the removal of its SUMOylation. We further demonstrate that RBM33 is critical for the tumorigenesis of head-neck squamous cell carcinoma (HNSCC). RBM33 promotes autophagy by recruiting ALKBH5 to demethylate and stabilize DDIT4 mRNA, which is responsible for the oncogenic function of RBM33 in HNSCC cells. Altogether, our study uncovers the mechanism of selectively demethylate m6A methylation of a subset of transcripts during tumorigenesis that may explain demethylation selectivity in other cellular processes, and we showed its importance in the maintenance of tumorigenesis of HNSCC.


Assuntos
Homólogo AlkB 5 da RNA Desmetilase , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Carcinogênese
4.
Genes Dev ; 35(23-24): 1595-1609, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34819352

RESUMO

Binding of microRNAs (miRNAs) to mRNAs normally results in post-transcriptional repression of gene expression. However, extensive base-pairing between miRNAs and target RNAs can trigger miRNA degradation, a phenomenon called target RNA-directed miRNA degradation (TDMD). Here, we systematically analyzed Argonaute-CLASH (cross-linking, ligation, and sequencing of miRNA-target RNA hybrids) data and identified numerous candidate TDMD triggers, focusing on their ability to induce nontemplated nucleotide addition at the miRNA 3' end. When exogenously expressed in various cell lines, eight triggers induce degradation of corresponding miRNAs. Both the TDMD base-pairing and surrounding sequences are essential for TDMD. CRISPR knockout of endogenous trigger or ZSWIM8, a ubiquitin ligase essential for TDMD, reduced miRNA degradation. Furthermore, degradation of miR-221 and miR-222 by a trigger in BCL2L11, which encodes a proapoptotic protein, enhances apoptosis. Therefore, we uncovered widespread TDMD triggers in target RNAs and demonstrated an example that could functionally cooperate with the encoded protein.


Assuntos
MicroRNAs , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Pareamento de Bases , MicroRNAs/genética , MicroRNAs/metabolismo , Estabilidade de RNA/genética , RNA Mensageiro/genética
5.
J Biol Chem ; 300(10): 107780, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39276941

RESUMO

Resistance to DNA-damaging agents is a major unsolved challenge for breast cancer patients undergoing chemotherapy. Here, we show that elevated expression of transcriptional repressor GATA binding 1 (TRPS1) is associated with lower drug sensitivity, reduced response rate, and poor prognosis in chemotherapy-treated breast cancer patients. Mechanistically, elevated TRPS1 expression promotes hyperactivity of DNA damage repair (DDR) in breast cancer cells. We provide evidence that TRPS1 dynamically localizes to DNA breaks in a Ku70-and Ku80-dependent manner and that TRPS1 is a new member of the DDR protein family. We also discover that the dynamics of TRPS1 assembly at DNA breaks is regulated by its reversible PARylation in the DDR, and that mutations of the PARylation sites on TRPS1 lead to increased sensitivity to chemotherapeutic drugs. Taken together, our findings provide new mechanistic insights into the DDR and chemoresistance in breast cancer patients and identify TRPS1 as a critical DDR protein. TRPS1 may also be considered as a target to improve chemo-sensitization strategies and, consequently, clinical outcomes for breast cancer patients.

6.
Mol Carcinog ; 63(11): 2218-2236, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39136610

RESUMO

Lung squamous cell carcinoma (LUSC) is one of the most common malignant tumors of the respiratory. Pyroptosis plays an essential role in cancer, but there is limited research investigating pyroptosis in LUSC. In this study, pyroptosis-related genes were observed to have extensive multiomics alterations in LUSC through analysis of the TCGA database. Utilizing machine learning for selection and verifying expression levels, GSDMC was chosen as the critical gene for further experiments. Our research found that GSDMC is overexpressed in LUSC tissues and cells, and is associated with poor prognosis. Knockdown of GSDMC in LUSC inhibits cell proliferation, invasion, metastasis, chemotherapeutic sensitivity, and reduced tumor formation in nude mice, accompanied by downregulation of proliferative and EMT-related protein expression. However, these effects were counteracted in cells where GSDMC is overexpressed. Mechanistically, the oncogenic role of GSDMC is primarily achieved through the activation of the AKT/mTOR pathway, and this effect can be significantly reversed by rapamycin. Finally, SMAD4's interaction with the promoter region of GSDMC results in the suppression of GSDMC expression. In summary, our study through bioinformatics and experimental approaches not only proves that SMAD4 regulates the protumorigenic role of GSDMC through transcriptional targeting, but also indicates the possibility of developing the SMAD4/GSDMC/AKT/mTOR signaling axis as a potential biomarker and treatment target for LUSC.


Assuntos
Carcinoma de Células Escamosas , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , Camundongos Nus , Proteínas Proto-Oncogênicas c-akt , Piroptose , Transdução de Sinais , Serina-Treonina Quinases TOR , Humanos , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Animais , Prognóstico , Camundongos , Piroptose/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Masculino , Proteína Smad4/genética , Proteína Smad4/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo
7.
J Urol ; 211(5): 669-676, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38591701

RESUMO

PURPOSE: Partial nephrectomy is standard-of-care treatment for small renal masses. As utilization of partial nephrectomy increases and includes larger and complex tumors, the risk of conversion to radical nephrectomy likely increases. We evaluated incidence and reason for conversion to radical nephrectomy in patients scheduled for partial nephrectomy by surgeons participating in MUSIC (the Michigan Urologic Surgery Improvement Collaborative). MATERIALS AND METHODS: All patients in whom robotic partial nephrectomy was planned were stratified by completed procedure (robotic partial nephrectomy vs radical nephrectomy). Preoperative and intraoperative records were reviewed for preoperative assessment of difficulty and reason for conversion. Patient, tumor, pathologic, and practice variables were compared between cohorts. RESULTS: Of 650 patients scheduled for robotic partial nephrectomy, conversion to radical nephrectomy occurred in 27 (4.2%) patients. No conversions to open were reported. Preoperative documentation indicated a plan for possible conversion in 18 (67%) patients including partial with possible radical (n = 8), partial vs radical (n = 6), or likely radical nephrectomy (n = 4). Intraoperative documentation indicated that only 5 (19%) conversions were secondary to bleeding, with the remaining conversions due to tumor complexity and/or oncologic concerns. Patients undergoing conversion had larger (4.7 vs 2.8 cm, P < .001) and higher-complexity tumors (64% vs 6%, P < .001) with R.E.N.A.L. (for radius, exophytic/endophytic, nearness of tumor to collecting system, anterior/posterior, location relative to polar line) nephrometry score ≥ 10. The converted cases had a higher rate of ≥ pT3 (27% vs 8.4%, P = .008). CONCLUSIONS: There was a low rate of conversion from robotic partial to radical nephrectomy in the MUSIC-KIDNEY (Kidney mass: Identifying and Defining Necessary Evaluation and therapY) collaborative, and an even lower risk of conversion due to uncontrolled bleeding. Targeted review of each conversion identified appropriate decision-making based on oncologic risk in most cases.


Assuntos
Neoplasias Renais , Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Neoplasias Renais/cirurgia , Neoplasias Renais/patologia , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Resultado do Tratamento , Nefrectomia/efeitos adversos , Nefrectomia/métodos , Estudos Retrospectivos
8.
J Org Chem ; 89(18): 13730-13734, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39196636

RESUMO

Here, we report an efficient transition-metal-free C(sp2)-C(sp3) Suzuki-Miyaura-type cross-coupling between α-halo Weinreb-type amides and arylboronic acids. The reaction is carried out by capturing active aza-oxyallyl cation (AOAC) with arylboronic acid to form a boron "ate" complex, followed by 1,4-migration to give α-aryl amides with good yields.

9.
J Geriatr Psychiatry Neurol ; : 8919887241289532, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39350728

RESUMO

OBJECTIVE: To determine the association between antipsychotic prescriptions and incident dementia in patients with schizophrenia or schizoaffective disorder. METHODS: In this retrospective cohort study, Cox Proportional hazard models estimated the association between antipsychotic prescriptions and incident dementia in participants ≥50 years of age with a schizophrenia/schizoaffective disorder diagnosis over 12 years. Confounding was controlled by E-balance. RESULTS: Cumulative dementia incidence was significantly greater among those with an antipsychotic prescription compared to those without (7.9% vs 5.5%, P < 0.0001). After controlling for confounding, antipsychotic prescriptions were associated with a 92% increased risk for dementia (HR = 1.92; 95% CI:1.13-3.27). This association was not significant among those aged ≥65 years. Antipsychotic prescription type (eg, first generation, yes or no) did not affect dementia risk but prescription number did. CONCLUSION: Antipsychotic prescriptions were associated with almost twice the incidence of dementia compared to patients without in those with schizophrenia/schizoaffective disorder.

10.
Aesthet Surg J ; 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39429197

RESUMO

BACKGROUND: While percutaneous external fixation has gained popularity in transconjunctival blepharoplasty due to its simplicity and minimal incision, internal fixation remains the standard approach in transcutaneous blepharoplasty. OBJECTIVES: This study aims to assess the safety and effectiveness of percutaneous external fixation specifically in transcutaneous fat repositioning blepharoplasty. METHODS: From May 2022 to December 2023, a consecutive cohort of 97 patients underwent this surgical technique. Building upon the principles of transconjunctival fat repositioning, the procedure involved a minimal incision targeting the muscle layer, a conservative release of the tear trough ligament, and the repositioning of fat secured with percutaneous external fixation. Surgical outcomes were evaluated using the Barton grading system and FACE-Q scales for patient-reported outcomes. RESULTS: Following a mean follow-up of 7.2 months (ranging from 6 to 17 months), a resolution of tear trough deformities and eyelid bags was achieved in over 92% of cases. Notably, significant improvements (P < 0.05) were observed in lower eyelid aesthetics as measured by the FACE-Q scale, with a concomitant enhancement in patients' social confidence (P < 0.05). Overall, patients expressed satisfaction with their decision to undergo the procedure (71.0±19.1). Complications necessitating revision surgery included isolated cases of hematoma evacuation, fat injection, excision of excess fat, and skin excision. CONCLUSIONS: External fixation in transcutaneous blepharoplasty is technically less complex and minimally invasive, effectively securing transposed fat pedicles safely, presenting a viable alternative to conventional fixation techniques.

11.
Int Wound J ; 21(4): e14622, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38158884

RESUMO

This study aims to evaluate the clinical effects of different blood derivatives on wound healing using network meta-analysis. PubMed, Embase, OVID, Web of Science, SCOPUS and Cochrane Central were searched to obtain studies about blood derivatives on wound healing until October 2023. R 4.2.0 and Stata 15.0 softwares were used for data analysis. Forty-four studies comprising 5164 patients were included. The results of network meta-analysis showed that the healing area from high to low was GF + ORCCB, ORCCB, GF, PRF, Unnas paste dressing, APG, PRP injection, PRP, PRP + thrombin gel, PPP, HPL, CT. The healing time from low to high was PRP + thrombin gel, GF, PRP, PC + K, PC, APG, PRF, CT, Silver sulfadiazine ointment. The number of patients cured from high to low was APG, PRP injection, PRP, Aurix, PRF, Leucopatch, HPL, Antimicrobial Ointment Dressing, CT, 60 µg/cm2 repifermin, 120 µg/cm2 repifermin, AFG, PPP. The order of analgesic effect from high to low was AFG, Aminogam gel, PRF, PRP, Oxidised oil, APG, GF, CT. The order of the number of wound infection cases from low to high is APG, 20 µg/cm2 repifermin, 60 µg/cm2 repifermin, PRP, LeucoPatch, CT, PPP, Antiseptic ointment dressing. Healing area: GF + ORCCB had the best effect; Healing time: PRP + thrombin gel took the shortest time. The number of cured patients and the reduction of wound infection: APG has the best effect. Analgesic effect: AFG has the best effect. More studies with large sample sizes are needed to confirm the above findings.


Assuntos
Plasma Rico em Plaquetas , Infecção dos Ferimentos , Humanos , Metanálise em Rede , Trombina/farmacologia , Pomadas , Fator 10 de Crescimento de Fibroblastos/farmacologia , Cicatrização , Resultado do Tratamento , Analgésicos
12.
Biochem Biophys Res Commun ; 684: 149101, 2023 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-37879251

RESUMO

Tripartite motif (TRIM) family proteins as E3-ligases participate in various biological processes. TRIM21, as the first autoantibody protein, has been found to be associated with autophagy. However, the role of TRIM21 engaging in autophagy is still unclear. In this study, TRIM21 forms significate puncta in the cytoplasm and undergoes liquid-liquid phase separation in vitro. Furthermore, we identify phase separation of the coiled-coil (CC) domain is essential for autophagosome to mediate autophagy-related protein recruited. These findings show that phase separation of the CC domain of TRIM21 promotes autophagosome to impact cell fate.


Assuntos
Autofagia , Proteínas , Autofagia/fisiologia , Domínios Proteicos , Ubiquitina-Proteína Ligases/metabolismo , Proteínas com Motivo Tripartido
13.
Analyst ; 148(10): 2316-2326, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37096998

RESUMO

A novel biomass-derived magnetic nanocomposite of Fe3O4-Chitin@NADES-CC composed of a natural deep eutectic solvent (NADES), biological polysaccharide (Chitin) and magnetic Fe3O4 was synthesized. After being systematically characterized by Fourier transform infrared spectrometry, thermogravimetry, vibrating sample magnetometry, X-ray diffraction, transmission electron microscopy and dynamic light scattering, Fe3O4-Chitin@NADES-CC was used as an extractant to separate trypsin (Tryp) on the basis of magnetic solid phase extraction. Simultaneously, the extraction conditions of Fe3O4-Chitin@NADES-CC for Tryp were investigated in turn by single-factor experiments, including screening the types of extractants, the initial concentration of Tryp, the pH value of the solution, the influence of ionic strength, extraction time and temperature, etc. Under the optimal conditions, the extraction capacity of Fe3O4-Chitin@NADES-CC for Tryp could reach up to 1082.67 mg g-1. Adsorption isotherm tests certified that the Langmuir adsorption equilibrium fitted well with the extraction model in this study, which showed that the extraction of Fe3O4-Chitin@NADES-CC for Tryp was monolayer adsorption. In addition, in the sections on the regeneration-reuse, selectivity and methodological studies, all the results exhibited the superiority of the Fe3O4-Chitin@NADES-CC and Tryp separation strategy which has been established in this work. Finally, Fe3O4-Chitin@NADES-CC was ultimately applied to the separation of Tryp from a real bovine pancreas crude extract by the analysis of SDS-PAGE. All the above results highlight that the proposed Fe3O4-Chitin@NADES-CC biomass-derived magnetic nanocomposite can be applied in the field of protein purification.


Assuntos
Solventes Eutéticos Profundos , Nanocompostos , Animais , Bovinos , Tripsina , Colina , Biomassa , Solventes/química , Extração em Fase Sólida/métodos , Fenômenos Magnéticos , Nanocompostos/química , Quitina
14.
Mol Biol Rep ; 50(8): 6557-6568, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37338733

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is a serious health threat worldwide. Defective mitophagy has been reported to induce mitochondrial dysfunction, which is closely associated with CKD pathogenesis. Honokiol (HKL) is a bioactive component of Magnolia officinalis that has multiple efficacies. Our study aimed to investigate the effect of HKL on a CKD rat model and explore the possible mechanisms of mitophagy mediated by Bcl-2 interacting protein 3 and BNIP3-like (NIX) (also known as the BNIP3/NIX pathway) and FUN14 domain-containing 1 (the FUNDC1 pathway) and the role of the AMP-activated protein kinase (AMPK) pathway. METHODS: A CKD rat model was established by feeding the animals dietary adenine (0.75% w/w, 3 weeks). Simultaneously, the treatment group was given HKL (5 mg/kg/day, 4 weeks) by gavage. Renal function was assessed by measuring serum creatinine (Scr) and blood urea nitrogen (BUN) levels. Pathological changes were analyzed by periodic acid-Schiff (PAS) and Masson's trichrome staining. Protein expression was evaluated by Western blotting and immunohistochemistry. RESULTS: HKL treatment ameliorated the decline in renal function and reduced tubular lesions and interstitial fibrosis in CKD rats. Accordingly, the renal fibrosis markers Col-IV and α-SMA were decreased by HKL. Moreover, HKL suppressed the upregulation of the proapoptotic proteins Bad and Bax and Cleaved caspase-3 expression in CKD rats. Furthermore, HKL suppressed BNIP3, NIX and FUNDC1 expression, leading to the reduction of excessive mitophagy in CKD rats. Additionally, AMPK was activated by adenine, and HKL reversed this change and significantly decreased the level of activated AMPK (phosphorylated AMPK, P-AMPK). CONCLUSION: HKL exerted a renoprotective effect on CKD rats, which was possibly associated with BNIP3/NIX and FUNDC1-mediated mitophagy and the AMPK pathway.


Assuntos
Mitofagia , Insuficiência Renal Crônica , Ratos , Animais , Proteínas Quinases Ativadas por AMP/metabolismo , Mitocôndrias/metabolismo , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Membrana/metabolismo
15.
Carcinogenesis ; 43(7): 659-670, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35353881

RESUMO

Our earlier work demonstrated varying potency of dihydromethysticin (DHM) as the active kava phytochemical for prophylaxis of tobacco carcinogen nicotine-derived nitrosamine ketone (NNK)-induced mouse lung carcinogenesis. Efficacy was dependent on timing of DHM gavage ahead of NNK insult. In addition to DNA adducts in the lung tissues mitigated by DHM in a time-dependent manner, our in vivo data strongly implicated the existence of DNA damage-independent mechanism(s) in NNK-induced lung carcinogenesis targeted by DHM to fully exert its anti-initiation efficacy. In the present work, RNA seq transcriptomic profiling of NNK-exposed (2 h) lung tissues with/without a DHM (8 h) pretreatment revealed a snap shot of canonical acute phase tissue damage and stress response signaling pathways as well as an activation of protein kinase A (PKA) pathway induced by NNK and the restraining effects of DHM. The activation of the PKA pathway by NNK active metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) at a concentration incapable of promoting DNA adduct was confirmed in a lung cancer cell culture model, potentially through NNAL binding to and activation of the ß-adrenergic receptor. Our in vitro and in vivo data overall support the hypothesis that DHM suppresses PKA activation as a key DNA damage-independent mechanistic lead, contributing to its effective prophylaxis of NNK-induced lung carcinogenesis. Systems biology approaches with a detailed temporal dissection of timing of DHM intake versus NNK exposure are warranted to fill the knowledge gaps concerning the DNA damage-driven mechanisms and DNA damage-independent mechanisms to optimize the implementation strategy for DHM to achieve maximal lung cancer chemoprevention.


Assuntos
Neoplasias Pulmonares , Nitrosaminas , Animais , Carcinogênese/induzido quimicamente , Carcinogênese/metabolismo , Carcinógenos/metabolismo , Carcinógenos/toxicidade , Proteínas Quinases Dependentes de AMP Cíclico/efeitos adversos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Adutos de DNA/metabolismo , Dano ao DNA , Pulmão/metabolismo , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/prevenção & controle , Camundongos , Nitrosaminas/metabolismo , Nitrosaminas/toxicidade , Pironas
16.
Development ; 146(14)2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31320323

RESUMO

The sinoatrial node (SAN), the primary cardiac pacemaker, consists of a head domain and a junction/tail domain that exhibit different functional properties. However, the underlying molecular mechanism defining these two pacemaker domains remains elusive. Nkx2-5 is a key transcription factor essential for the formation of the working myocardium, but it was generally thought to be detrimental to SAN development. However, Nkx2-5 is expressed in the developing SAN junction, suggesting a role for Nkx2-5 in SAN junction development and function. In this study, we present unambiguous evidence that SAN junction cells exhibit unique action potential configurations intermediate to those manifested by the SAN head and the surrounding atrial cells, suggesting a specific role for the junction cells in impulse generation and in SAN-atrial exit conduction. Single-cell RNA-seq analyses support this concept. Although Nkx2-5 inactivation in the SAN junction did not cause a malformed SAN at birth, the mutant mice manifested sinus node dysfunction. Thus, Nkx2-5 defines a population of pacemaker cells in the transitional zone. Despite Nkx2-5 being dispensable for SAN morphogenesis during embryogenesis, its deletion hampers atrial activation by the pacemaker.


Assuntos
Relógios Biológicos/genética , Linhagem da Célula/genética , Proteína Homeobox Nkx-2.5/fisiologia , Miócitos Cardíacos/citologia , Nó Sinoatrial/citologia , Nó Sinoatrial/fisiologia , Animais , Separação Celular , Embrião de Mamíferos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Átrios do Coração/citologia , Átrios do Coração/embriologia , Camundongos , Camundongos Transgênicos , Morfogênese/genética , Contração Miocárdica/genética , Miócitos Cardíacos/fisiologia , Gravidez
17.
J Org Chem ; 87(19): 13138-13153, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36166815

RESUMO

Electrochemical synthesis of polysubstituted sulfonated pyrazoles from enaminones and sulfonyl hydrazides was established under metal-free, exogenous-oxidant-free, and mild conditions. By judicious choice of different electrochemical reaction conditions, NH2-functionalized enaminones or N,N-disubstituted enaminones can react with aryl/alkyl sulfonyl hydrazides to afford tetra- or trisubstituted sulfonated pyrazoles in moderate to good yields, respectively. The gram-scale electrochemical transformation demonstrated the efficiency and practicability of this synthetic strategy. In addition, the sulfonated NH-pyrazole can be obtained via the dissociation of the N-tosyl group. Mechanistic studies reveal that the electrochemical cascade reaction synthesis of polysubstituted sulfonated pyrazoles proceeded via the sequence of intermolecular condensation, radical-radical cross coupling sulfonylation, and pyrazole annulation.

18.
Brain ; 144(1): 288-309, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33246331

RESUMO

Extracellular vesicles are highly transmissible and play critical roles in the propagation of tau pathology, although the underlying mechanism remains elusive. Here, for the first time, we comprehensively characterized the physicochemical structure and pathogenic function of human brain-derived extracellular vesicles isolated from Alzheimer's disease, prodromal Alzheimer's disease, and non-demented control cases. Alzheimer's disease extracellular vesicles were significantly enriched in epitope-specific tau oligomers in comparison to prodromal Alzheimer's disease or control extracellular vesicles as determined by dot blot and atomic force microscopy. Alzheimer's disease extracellular vesicles were more efficiently internalized by murine cortical neurons, as well as more efficient in transferring and misfolding tau, than prodromal Alzheimer's disease and control extracellular vesicles in vitro. Strikingly, the inoculation of Alzheimer's disease or prodromal Alzheimer's disease extracellular vesicles containing only 300 pg of tau into the outer molecular layer of the dentate gyrus of 18-month-old C57BL/6 mice resulted in the accumulation of abnormally phosphorylated tau throughout the hippocampus by 4.5 months, whereas inoculation of an equal amount of tau from control extracellular vesicles, isolated tau oligomers, or fibrils from the same Alzheimer's disease donor showed little tau pathology. Furthermore, Alzheimer's disease extracellular vesicles induced misfolding of endogenous tau in both oligomeric and sarkosyl-insoluble forms in the hippocampal region. Unexpectedly, phosphorylated tau was primarily accumulated in glutamic acid decarboxylase 67 (GAD67) GABAergic interneurons and, to a lesser extent, glutamate receptor 2/3-positive excitatory mossy cells, showing preferential extracellular vesicle-mediated GABAergic interneuronal tau propagation. Whole-cell patch clamp recordings of CA1 pyramidal cells showed significant reduction in the amplitude of spontaneous inhibitory post-synaptic currents. This was accompanied by reductions in c-fos+ GAD67+ neurons and GAD67+ neuronal puncta surrounding pyramidal neurons in the CA1 region, confirming reduced GABAergic transmission in this region. Our study posits a novel mechanism for the spread of tau in hippocampal GABAergic interneurons via brain-derived extracellular vesicles and their subsequent neuronal dysfunction.


Assuntos
Doença de Alzheimer/patologia , Encéfalo/patologia , Vesículas Extracelulares/metabolismo , Interneurônios/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/metabolismo , Animais , Encéfalo/metabolismo , Vesículas Extracelulares/patologia , Feminino , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/patologia , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Interneurônios/patologia , Masculino , Camundongos Endogâmicos C57BL , Células Piramidais/metabolismo , Células Piramidais/patologia
19.
J Environ Manage ; 301: 113912, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34628281

RESUMO

The increase in coal consumption and its impact on the environment has become a bottleneck that hinders sustainable development. This paper discusses the effect of economic growth and coal intensity on China's coal consumption during 2005-2017 using the Laspeyres index decomposition method. The decoupling of coal consumption from economic growth was examined in conjunction with the Tapio elasticity index, and the decoupling contributions of economic growth and coal intensity are further determined. The results indicated that economic growth drives an increase in coal consumption; however, the contribution rate declines gradually with decrease in economic growth rate in each province. Further research showed that the secondary industry is the main contributor to the increment, and the rapid development of tertiary industry increases indirect coal consumption. Coal intensity has a positive impact on curbing coal consumption, but it is not sufficient to offset the increment generated by the economic effect. Moreover, in each province, the curbing effect gradually decreased as the decline in coal intensity weakened in the secondary industry. Furthermore, coal consumption is weakly decoupled from economic growth over the long term, and the secondary industry will determine the future trend of decoupling.


Assuntos
Dióxido de Carbono , Carvão Mineral , Dióxido de Carbono/análise , China , Desenvolvimento Econômico , Indústrias
20.
Opt Lett ; 46(18): 4538-4541, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34525044

RESUMO

Speckle correlation imaging (SCI) has found tremendous versatility compared with other scattering imaging approaches due to its single-shot data acquisition strategy, relatively simple optical setup, and high-fidelity reconstruction performance. However, this simplicity requires SCI experiments to be performed strictly in a darkroom condition. As background noise increases, the speckle contrast rapidly decreases, making precise interpretation of the data extremely difficult. Here, we demonstrate a method by refining the speckle in the autocorrelation domain to achieve high-performance single-shot imaging. Experiment results prove that our method is adapted to estimate objects in a low signal-to-background ratio (SBR) circumstance even if the SBR is about -23dB. Laboratory and outdoor SCI experiments are performed.

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