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1.
Org Lett ; 26(15): 3304-3309, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38587334

RESUMO

A facile and efficient radical tandem vinylogous aldol and intramolecular [2 + 2] cycloaddition reaction for direct synthesis of cyclobutane-containing benzocyclobutenes (BCBs) under extremely mild conditions without using any photocatalysts is reported. This approach exhibited definite compatibility with functional groups and afforded new BCBs with excellent regioselectivity and high yields. Moreover, detailed mechanism studies were carried out both experimentally and theoretically. The readily accessible, low-cost, and ecofriendly nature of the developed strategy will endow it with attractive applications in organic and medicinal chemistry.

2.
J Mater Chem B ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38655586

RESUMO

The clinical treatment of chronic diabetic wounds is a long-standing thorny issue. Strategies targeting the diabetic micro-environment have been developed to promote wound healing. However, it remains challenging to reverse the adverse conditions and re-activate tissue regeneration and angiogenesis. In this work, we develop injectable hydrogels that are responsive to acidic conditions, reactive oxygen species (ROS), and high glucose levels in a diabetic wound micro-environment to sustainably deliver tannic acid (TA) to augment antibacterial, anti-inflammatory, and anti-oxidative activities. This triple-responsive mechanism is designed by introducing dynamic acylhydrazone and phenylboronic ester bonds to crosslink modified hyaluronic acid (HA) chains. At a diabetic wound, the acylhydrazone bonds may be hydrolyzed at low pH. Meanwhile, glucose may compete with TA, and ROS may oxidize the C-B bond to release TA. Thus, sustained release of TA is triggered by the diabetic micro-environment. The released TA effectively scavenges ROS and kills bacteria. In vivo experiments on diabetic mice demonstrate that the hydrogel dressing highly promotes angiogenesis and extracellular matrix (ECM) deposition, leading to eventual full healing of diabetic skin wounds. This micro-environment-triggered triple-responsive drug release provides a promising method for chronic diabetic wound healing.

3.
Polymers (Basel) ; 16(7)2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38611277

RESUMO

To investigate the relationship between structures and adsorption properties, four different morphologies of chitosan, with hydrogel (CSH), aerogel (CSA), powder (CSP), and electrospinning nanofiber (CSEN) characteristics, were employed as adsorbents for the removal of Acid Red 27. The structures and morphologies of the four chitosan adsorbents were characterized with SEM, XRD, ATR-FTIR, and BET methods. The adsorption behaviors and mechanisms of the four chitosan adsorbents were comparatively studied. All adsorption behaviors exhibited a good fit with the pseudo-second-order kinetic model (R2 > 0.99) and Langmuir isotherm model (R2 > 0.99). Comparing the adsorption rates and the maximum adsorption capacities, the order was CSH > CSA > CSP > CSEN. The maximum adsorption capacities of CSH, CSA, CSP, and CSEN were 2732.2 (4.523), 676.7 (1.119), 534.8 (0.885), and 215.5 (0.357) mg/g (mmol/g) at 20 °C, respectively. The crystallinities of CSH, CSA, CSP, and CSEN were calculated as 0.41%, 6.97%, 8.76%, and 39.77%, respectively. The crystallinity of the four chitosan adsorbents was the main factor impacting the adsorption rates and adsorption capacities, compared with the specific surface area. With the decrease in crystallinity, the adsorption rates and capacities of the four chitosan adsorbents increased gradually under the same experimental conditions. CSH with a low crystallinity and large specific surface area resulted in the highest adsorption rate and capacity.

4.
Mol Biol Rep ; 51(1): 115, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38227267

RESUMO

BACKGROUND: Recent studies have shown that the expression of bHLH transcription factors Hes1, Ascl1, and Oligo2 has an oscillating balance in neural stem cells (NSCs) to maintain their self-proliferation and multi-directional differentiation potential. This balance can be disrupted by exogenous stimulation. Our previous work has identified that electrical stimulation could induce neuronal differentiation of mouse NSCs. METHODS: To further evaluate if physiological electric fields (EFs)-induced neuronal differentiation is related to the expression patterns of bHLH transcription factors Hes1, Ascl1, and Oligo2, mouse embryonic brain NSCs were used to investigate the expression changes of Ascl1, Hes1 and Oligo2 in mRNA and protein levels during EF-induced neuronal differentiation. RESULTS: Our results showed that NSCs expressed high level of Hes1, while expression of Ascl1 and Oligo2 stayed at very low levels. When NSCs exited proliferation, the expression of Hes1 in differentiated cells began to decrease and oscillated at the low expression level. Oligo2 showed irregular changes in low expression level. EF-stimulation significantly increased the expression of Ascl1 at mRNA and protein levels accompanied by an increased percentage of neuronal differentiation. What's more, over-expression of Hes1 inhibited the neuronal differentiation induced by EFs. CONCLUSION: EF-stimulation directed neuronal differentiation of NSCs by promoting the continuous accumulation of Ascl1 expression and decreasing the expression of Hes1.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Encéfalo , Fator de Transcrição 2 de Oligodendrócitos , Fatores de Transcrição HES-1 , Animais , Camundongos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular , Estimulação Elétrica , RNA Mensageiro/genética , Fatores de Transcrição HES-1/genética , Fator de Transcrição 2 de Oligodendrócitos/genética
5.
J Invest Dermatol ; 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38206270

RESUMO

Mechanical itch, which is defined as an itch sensation caused by innocuous mechanical force, may warn of the potential risk in the skin. The increased mechanosensitivity in sensory neurons may cause scratch-induced itch and promote the transition from acute itch to chronic itch. Recent studies have not only expanded our knowledge about the neuronal circuits in the CNS but have also highlighted the importance of the peripheral epithelia-immune-neuronal crosstalk in the development of mechanical itch. In this review, we will summarize related findings about the molecular and cellular mechanisms of mechanical itch in the skin.

6.
Int J Biol Macromol ; 257(Pt 2): 128645, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38061526

RESUMO

Canine distemper virus (CDV) is a highly contagious pathogen that causes severe diarrhea, fever and vomiting in domestic dogs, posing a serious threat to the dog breeding industry. Currently, there are no effective therapeutic agents for emergency treatment despite the availability of vaccines against CDV infection. Single-chain fragment variable (scFv) antibody has been demonstrated to effectively inhibit virus infections, suggesting a potential candidate as a therapeutic agent for canine distemper. In this study, a phage-displayed scFv library was constructed from the peripheral blood lymphocytes of dog immunized intramuscularly with live-attenuated CDV vaccine, and was subjected to four rounds of pannings against CDV. Subsequent indirect enzyme-linked immunosorbent assay screening revealed high-affinity scFv antibodies specific to CDV, and indirect immunofluorescence assay screening revealed CDV-neutralizing activity of scFv antibodies. Our results showed that a scFv antibody 4-15 (scFv 4-15) with high-affinity binding to CDV and neutralizing activity against CDV was obtained, which displayed effective therapeutic potential in vivo for dogs challenged with a lethal dose of CDV. Conclusively, the scFv 4-15 with high-affinity binding and neutralizing activity to CDV that was obtained by phage display technology provides a promising candidate for the therapeutic agents against CDV infection.


Assuntos
Bacteriófagos , Vírus da Cinomose Canina , Cinomose , Anticorpos de Cadeia Única , Vacinas Virais , Animais , Cães , Anticorpos de Cadeia Única/farmacologia , Anticorpos Antivirais , Cinomose/prevenção & controle
7.
Molecules ; 28(22)2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-38005375

RESUMO

A facile and efficient visible-light-mediated method for directly converting 1,4-naphthoquinones into dihydrocyclo-buta[b]naphthalene-3,8-diones (DHCBNDOs) under mild and clean conditions without using any photocatalysts is reported. This approach exhibited favorable compatibility with functional groups and afforded a series of DHCBNDOs with excellent regioselectivity and high yields. Moreover, detailed mechanism studies were carried out both experimentally and theoretically. The readily accessible, low-cost and ecofriendly nature of the developed strategy will endow it with attractive applications in organic and medicinal chemistry.

8.
BMC Oral Health ; 23(1): 878, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978362

RESUMO

BACKGROUND: N6-methyladenosine (m6A) RNA modification regulators play an important role in many human diseases, and its abnormal expression can lead to the occurrence and development of diseases. However, their significance in pulpitis remains largely unknown. Here, we sought to identify and validate the m6A RNA regulatory network in pulpitis. METHODS: Gene expression data for m6A regulators in human pulpitis and normal pulp tissues from public GEO databases were analyzed. Bioinformatics analysis including Gene ontology (GO) functional, and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses were performed by R package, and Cytoscape software was used to study the role of m6A miRNA-mRNA regulatory network in pulpitis. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of key m6A regulators in collected human pulpitis specimens. RESULTS: Differential genes between pulpitis and normal groups were found from the GEO database, and further analysis found that there were significant differences in the m6A modification-related genes ALKBH5, METTL14, METTL3, METTL16, RBM15B and YTHDF1. And their interaction relationships and hub genes were determined. The hub m6A regulator targets were enriched in immune cells differentiation, glutamatergic synapse, ephrin receptor binding and osteoclast differentiation in pulpitis. Validation by qRT-PCR showed that the expression of methylases METTL14 and METTL3 was decreased, thus these two genes may play a key role in pulpitis. CONCLUSION: Our study identified and validated the m6A RNA regulatory network in pulpitis. These findings will provide valuable resource to guide the mechanistic and therapeutic analysis of the role of key m6A modulators in pulpitis.


Assuntos
MicroRNAs , Pulpite , Humanos , Pulpite/genética , RNA Mensageiro/genética , Polpa Dentária , Biologia Computacional , Metiltransferases/genética
9.
Genes (Basel) ; 14(10)2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37895182

RESUMO

Dahlia (Dahlia variabilis) is a widely cultivated ornamental and medicinal plant in China. Recently, dahlia plants with symptoms of leaf mottling and distortion were collected in Hohhot, Inner Mongolia, China. The presence of dahlia common mosaic virus (DCMV), an unassigned species in the genus Caulimovirus, was confirmed by high-throughput sequencing. Three fragments of DCMV Inner Mongolia isolate (DCMV-IN) were PCR-amplified with specific primers, sequenced and assembled into the complete genome sequence with a GenBank accession number of OR494328. The double-stranded circular DNA genome of DCMV-IN consists of 7949 bp and contains six open reading frames (ORFs). Sequence analysis showed that DCMV-IN shared high sequence identities with other DCMV isolates available in the GenBank database. Phylogenetic analysis of DCMV isolates and other representative caulimoviruses based on genome sequence clustered four DCMV isolates to a single branch which was closest to dahlia mosaic virus (DMV). No recombination event was detected among the four DCMV isolates.


Assuntos
Caulimovirus , Dahlia , Caulimovirus/genética , Dahlia/genética , Filogenia , Genoma Viral , Reação em Cadeia da Polimerase
10.
Int J Biol Macromol ; 253(Pt 7): 127351, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37839600

RESUMO

Bovine viral diarrhea virus (BVDV) is one of the most important pathogens of cattle, causing numerous economic losses to the cattle industry. To date, many potential mechanisms of BVDV evading or subverting innate immunity are still unknown. In this study, an lnc-CYLD/miR-2383/CYLD axis involved in BVDV-host interactions was screened from RNA-seq-based co-expression networks analysis of long noncoding RNAs, microRNAs and mRNAs in BVDV-infected bovine cells, and underlying mechanisms of lnc-CYLD/miR-2383/CYLD axis regulating BVDV replication were explored. Results showed that BVDV-induced up-regulation of the lnc-CYLD competed for binding to the miR-2383, and then promoted CYLD expression, thereby inhibiting RIG-I-mediated type-I interferon (IFN) production, which was subsequently confirmed by treatment with lnc-CYLD overexpression and miR-2383 inhibitor. However, miR-2383 transfection and small interfering RNA-mediated lnc-CYLD knockdown inhibited CYLD expression and enhanced RIG-I-mediated type-I IFN production, inhibiting BVDV replication. In addition, interaction relationship between lnc-CYLD and miR-2383, and colocalization relationship of lnc-CYLD, miR-2383 and CYLD were confirmed by dual-luciferase assay and in situ hybridization assay. Conclusively, up-regulation of the lnc-CYLD as a competing endogenous RNA binds to the miR-2383 to reduce inhibitory effect of the miR-2383 on the CYLD expression, playing an important role in counteracting type-I IFN-dependent antiviral immunity to facilitate BVDV replication.


Assuntos
Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina , Interferon Tipo I , MicroRNAs , RNA Longo não Codificante , Animais , Bovinos , Proteína DEAD-box 58/genética , RNA Longo não Codificante/metabolismo , Replicação Viral/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Vírus da Diarreia Viral Bovina/genética , Interferon Tipo I/genética , Diarreia , Vírus da Diarreia Viral Bovina Tipo 1/genética
11.
iScience ; 26(8): 107477, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37599821

RESUMO

Smoking carcinogen nicotine-derived nitrosamine ketone (NNK) is the most potent contributor to lung adenocarcinoma (LUAD) development, but the mechanism has not been fully elucidated. Here, we reported that fatty acid translocase CD36 was significantly overexpressed in both human LUAD tissues and NNK-induced A/J mice LUAD tumors. The overexpressed CD36 was positively correlated with Src kinase activation, smoking status, metastasis, and worse overall survival of patients with smoking history. Upon NNK binding with α7 nicotinic acetylcholine receptor (α7nAChR), sarcolemmal CD36 was increased and it interacted with surface α7nAChR and cytosol Src simultaneously, which in turn activated Src and downstream pro-carcinogenic kinase ERK1/2 and Akt, and finally caused LUAD cells to form subcutaneous and pulmonary metastatic tumors. This process could be blocked by CD36 knockdown and CD36 irreversible inhibitor SSO. Furthermore, the effect of NNK was inhibited obviously in CD36-/- A/J mice. Thus, targeting CD36 may provide a breakthrough therapy of LUAD.

12.
Cell Death Dis ; 14(8): 548, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37612265

RESUMO

Obesity/overweight and lipid metabolism disorders have become increased risk factors for lung cancer. Fatty acid translocase CD36 promotes cellular uptake of fatty acids. Whether and how CD36 facilitates lung adenocarcinoma (LUAD) growth in high-fat environment is unknown. Here, we demonstrated that palmitic acid (PA) or high-fat diet (HFD) promoted LUAD cell proliferation and metastasis in a CD36-dependent manner. Mechanistically, CD36 translocated from cytoplasm to cell membrane and interacted with Src kinase upon PA stimulation in human LUAD cells. Akt and ERK, downstream of Src, were then activated to mediate LUAD cell proliferation and metastasis. Furthermore, PA treatment promoted CD36 sarcolemmal translocation, where it activated Rac1 and upregulated MMP-9 through Src-Akt/ERK pathway, resulting in redistribution of cortactin, N-WASP and Arp2/3, and finally led to occurrence of finger-like protrusions of actin on cell surface to enhance cell metastasis. Compared with normal-chew diet (NCD) mice, the HFD group exhibited higher level of blood free fatty acid (FFA) and cholesterol (TC), developed larger xenograft LUAD tumors and enhanced tumor cell metastatic potential, which were accompanied by obvious sarcolemmal actin remodeling and were blocked by simultaneous CD36 knockdown in LUAD cells. Consistently, xenografted and tail vein-injected scramble-RNA-A549 cells but not CD36-shRNA-A549 in HFD mice formed metastatic LUAD tumors on the lung. CD36 inhibitor SSO significantly inhibited LUAD cell metastasis to the lung. Collectively, CD36 initiates Src signaling to promote LUAD cell proliferation and actin remodeling-involved metastasis under high-fat environment. Our study provides the new insights that CD36 is a valid target for LUAD therapy.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Animais , Humanos , Camundongos , Actinas , Adenocarcinoma de Pulmão/genética , Antígenos CD36/genética , Proliferação de Células , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo
13.
Anal Chem ; 95(32): 11943-11952, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37526416

RESUMO

Schizophrenia is a common mental disorder with unclear mechanisms. Oxidative stress and neuroinflammation play important roles in the pathological process of schizophrenia. Superoxide anion (O2•-) is an important oxidative stress biomarker in vivo. However, due to the existence of the blood-brain barrier (BBB), few near-infrared (NIR) fluorescent probes have been used for the sensing and detection of O2•- in the brain. With this research, we developed the first near-infrared fluorescent probe (named CT-CF3) for noninvasive detection of endogenous O2•- in the brain of mice. Enabling fluorescence monitoring of the dynamic changes in O2•- flux due to the prolonged activation of microglia in neuroinflamed and schizophrenic (SZ) mice brains, thereby providing direct evidence for the relationship between oxidative stress, neuroinflammation, and schizophrenia. Furthermore, we confirmed the O2•- burst in the brains of first-episode schizophrenic mice and assessed the effect of two atypical antipsychotic drugs (risperidone and olanzapine) on redox homeostasis.


Assuntos
Corantes Fluorescentes , Doenças Neuroinflamatórias , Animais , Camundongos , Encéfalo/diagnóstico por imagem , Barreira Hematoencefálica , Estresse Oxidativo
14.
J Neural Eng ; 20(4)2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37433290

RESUMO

Objective.Three-dimensional (3D) neural tissue engineering is expected to provide new stride in developing neural disease models and functional substitutes to aid in the treatment of central nervous system injury. We have previously detailed an electrical stimulation (ES) system to generate 3D mouse engineered neural tissue (mENT)in vitro. However, ES-induced human ENT (hENT) has not previously been either investigated or identified in structural and functional manner. Here, we applied ES as a stimulator to regulate human neural stem cells in 3D Matrigel, explored the components and functional properties of hENTs.Approach.By immunofluorescence chemical staining and electron microscope imaging, we evaluated the effects of ES on (1) neuronal differentiation and maturation, (2) neurites outgrowth and alignment in hENT, (3) formation of synapses and myelin sheaths in hENT. We further investigated the formation of synaptic connections betweenex-vivo-fused mouse and human tissue. We used calcium imaging to detect activities of neurons in hENT culture.Results.ES could induce neuronal differentiation, the orderly growth of neurites and the maturation of neuron subtypes to construct a well-developed neuronal network with synapses and myelin sheaths. Most importantly, we discovered that raising extracellular K+concentration resulted the increasing neuronal excitability in the hENT, indicating electrical activities in neuronal cells.Significance.We applied ES to generate the organised 3D hENTs and identified them in both structural and functional manner.


Assuntos
Tecido Nervoso , Células-Tronco Neurais , Humanos , Camundongos , Animais , Neurônios/fisiologia , Neuritos , Estimulação Elétrica , Diferenciação Celular
15.
Eur Radiol ; 33(12): 8965-8973, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37452878

RESUMO

OBJECTIVES: To develop and validate a machine learning model based on contrast-enhanced CT to predict the risk of occurrence of the composite clinical endpoint (hospital-based intervention or death) in cirrhotic patients with acute variceal bleeding (AVB). METHODS: This retrospective study enrolled 330 cirrhotic patients with AVB between January 2017 and December 2020 from three clinical centers. Contrast-enhanced CT and clinical data were collected. Centers A and B were divided 7:3 into a training set and an internal test set, and center C served as a separate external test set. A well-trained deep learning model was applied to segment the liver and spleen. Then, we extracted 106 original features of the liver and spleen separately based on the Image Biomarker Standardization Initiative (IBSI). We constructed the Liver-Spleen (LS) model based on the selected radiomics features. The performance of LS model was evaluated by receiver operating characteristics and calibration curves. The clinical utility of models was analyzed using decision curve analyses (DCA). RESULTS: The LS model demonstrated the best diagnostic performance in predicting the composite clinical endpoint of AVB in patients with cirrhosis, with an AUC of 0.782 (95% CI 0.650-0.882) and 0.789 (95% CI 0.674-0.878) in the internal test and external test groups, respectively. Calibration curves and DCA indicated the LS model had better performance than traditional clinical scores. CONCLUSION: A novel machine learning model outperforms previously known clinical risk scores in assessing the prognosis of cirrhotic patients with AVB CLINICAL RELEVANCE STATEMENT: The Liver-Spleen model based on contrast-enhanced CT has proven to be a promising tool to predict the prognosis of cirrhotic patients with acute variceal bleeding, which can facilitate decision-making and personalized therapy in clinical practice. KEY POINTS: • The Liver-Spleen machine learning model (LS model) showed good performance in assessing the clinical composite endpoint of cirrhotic patients with AVB (AUC ≥ 0.782, sensitivity ≥ 80%). • The LS model outperformed the clinical scores (AUC ≤ 0.730, sensitivity ≤ 70%) in both internal and external test cohorts.


Assuntos
Varizes Esofágicas e Gástricas , Humanos , Varizes Esofágicas e Gástricas/diagnóstico por imagem , Estudos Retrospectivos , Hemorragia Gastrointestinal/terapia , Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico , Fatores de Risco , Prognóstico , Aprendizado de Máquina
16.
J Immunol Res ; 2023: 9946911, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37342762

RESUMO

Introduction: Circadian rhythm is involved in multiple biological activities and implicated in cancer development. However, the role of circadian rhythm in head and neck squamous cell carcinoma (HNSCC) has not been fully interpreted yet. Herein, the present study set out to explore the significance of circadian regulator genes (CRGs) in HNSCC. Materials and Methods: The molecular landscape and clinical significance of 13 CRGs in HNSCC were explored based on The Cancer Genome Atlas (TCGA). The biological functions of PER3, a key CRG, were validated by cellular experiments. The correlation of CRGs with microenvironment, pathway activities, and prognosis was determined by bioinformatic algorithms. A novel circadian score was introduced to evaluate the circadian modification pattern of each patient and further validated in an independent cohort from the Gene Expression Omnibus (GEO) dataset. Results: CRGs presented high heterogeneity in HNSCC at both genomic and transcriptomic levels. Specifically, PER3 indicated a better prognosis and inhibited HNSCC cell proliferation. Moreover, HNSCC tissues displayed three circadian regulator patterns with distinct clinical outcomes, transcriptomic characteristics, and microenvironment features. Circadian score was an independent risk factor and exhibited excellent predictive efficiency in both the training cohort from the TCGA database and the validation cohort from the GEO database. Conclusions: CRGs played an indispensable role in HNSCC development. An in-depth exploration of circadian rhythm would improve the understanding of HNSCC carcinogenesis and confer novel insights for future clinical practices.


Assuntos
Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/genética , Microambiente Tumoral/genética , Prognóstico , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica
17.
Artigo em Inglês | MEDLINE | ID: mdl-37196823

RESUMO

Pancreatic ß-cell apoptosis is a key feature of diabetes and can be induced by chronic exposure to saturated fatty acids (FAs). However, the underlying mechanisms remain poorly understood. We presently evaluated the role of Mcl-1 and mTOR in mice fed with high-fat-diet (HFD) and ß-cells exposed to the overloaded palmitic acid (PA). Compared with normal-chow-diet (NCD)-fed mice, HFD group showed impaired glucose tolerance after two months. Along with the diabetes progression, pancreatic islets first became hypertrophic and then atrophic, the ratio of ß-cell:α-cell increased in the islets of four months HFD-fed mice while decreased after six months. This process was accompanied by significantly increased ß-cell apoptosis and AMPK activity, and decreased Mcl-1 expression and mTOR activity. Consistently, glucose-induced insulin secretion dropped. In terms of mechanism, PA with lipotoxic dose could activate AMPK, which in turn inhibited ERK-stimulated Mcl-1Thr163 phosphorylation. Meanwhile, AMPK blocked Akt activity to release Akt inhibition on GSK3ß, followed by GSK3ß-initiated Mcl-1Ser159 phosphorylation. The context of Mcl-1 phosphorylation finally led to its degradation by ubiquitination. Also, AMPK inhibited the activity of mTORC1, resulting in a lower level of Mcl-1. Suppression of mTORC1 activity and Mcl-1 expression positively related to ß-cell failure. Alteration of Mcl-1 or mTOR expression rendered different tolerance of ß-cell to different dose of PA. In conclusion, lipid oversupply-induced dual modulation of mTORC1 and Mcl-1 finally led to ß-cell apoptosis and impaired insulin secretion. The study may help further understand the pathogenesis of ß-cell dysfunction in case of dyslipidemia, and provide promising therapeutic targets for diabetes.


Assuntos
Insulina , Proteínas Proto-Oncogênicas c-akt , Camundongos , Animais , Insulina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Regulação para Baixo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ácido Palmítico/farmacologia , Apoptose
18.
Chem Soc Rev ; 52(11): 3873-3926, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37190785

RESUMO

Oxidative stress is closely related to the physiopathology of numerous diseases. Reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) are direct participants and important biomarkers of oxidative stress. A comprehensive understanding of their changes can help us evaluate disease pathogenesis and progression and facilitate early diagnosis and drug development. In recent years, fluorescent probes have been developed for real-time monitoring of ROS, RNS and RSS levels in vitro and in vivo. In this review, conventional design strategies of fluorescent probes for ROS, RNS, and RSS detection are discussed from three aspects: fluorophores, linkers, and recognition groups. We introduce representative fluorescent probes for ROS, RNS, and RSS detection in cells, physiological/pathological processes (e.g., Inflammation, Drug Induced Organ Injury and Ischemia/Reperfusion Injury etc.), and specific diseases (e.g., neurodegenerative diseases, epilepsy, depression, diabetes and cancer, etc.). We then highlight the achievements, current challenges, and prospects for fluorescent probes in the pathophysiology of oxidative stress-related diseases.


Assuntos
Corantes Fluorescentes , Estresse Oxidativo , Humanos , Espécies Reativas de Oxigênio , Oxirredução , Biomarcadores , Espécies Reativas de Nitrogênio
19.
Chem Commun (Camb) ; 59(10): 1357-1360, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36649118

RESUMO

Neuroinflammation leads to a persistent oxidative stress in the brain, and is closely related to the pathology of various neurological disorders. Hypochlorous acid (HClO) is a reactive oxygen species (ROS) that, at high levels, can cause brain tissue damage and neurogenic apoptosis. Herein, we designed and synthesized a silicon-rhodamine (SiR)-based formohydrazide (FH)-containing fluorescent probe, denoted as SiR-FH, for sensing HClO. This probe showed good selectivity, rapid response and high sensitivity. SiR-FH was successfully used to detect endogenous and exogenous HClO in living cells. Moreover, SiR-FH realized real-time monitoring of change in HClO flux in the brains of mice with LPS-induced neuroinflammation. The probe provides a practical tool for the monitoring of oxidative stress related to neuroinflammation.


Assuntos
Corantes Fluorescentes , Ácido Hipocloroso , Camundongos , Animais , Rodaminas , Doenças Neuroinflamatórias , Encéfalo
20.
Methods ; 210: 20-35, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36634727

RESUMO

Oxidases and peroxidases are two subclasses of oxidoreductases. The abnormal expression of oxidases (such as tyrosinase, cytochrome P450 oxidases, and monoamine oxidases) and peroxidases (such as glutathione peroxidase, myeloperoxidase, and eosinophil peroxidase) is relative with some diseases. Therefore, the analysis of oxidases and peroxidases is great important for disease diagnosis and treatment. Fluorescent probes present simple protocol, high sensitivity and good stability in sensing field. Molecule fluorescent probes are constructed with chemical groups that tunes their fluorescence emission in response to binding events, chemical reactions, and the surrounding environment. A fluorescent probe is an efficient tool for visualizing the activity of enzymes in living organisms on the basis of its high specificity, sensitivity, and noninvasiveness characteristics. In this review, we focus on the sensing of oxidases and peroxidases by molecule fluorescent probes, and hope to bring new insight to wide researchers about oxidases and peroxidases in biological samples.


Assuntos
Oxirredutases , Peroxidases , Peroxidases/genética , Peroxidases/metabolismo , Corantes Fluorescentes/química , Sondas Moleculares , Diagnóstico por Imagem
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