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1.
Proc Natl Acad Sci U S A ; 121(16): e2318935121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38588421

RESUMO

Glucose is required for generating heat during cold-induced nonshivering thermogenesis in adipose tissue, but the regulatory mechanism is largely unknown. CREBZF has emerged as a critical mechanism for metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD). We investigated the roles of CREBZF in the control of thermogenesis and energy metabolism. Glucose induces CREBZF in human white adipose tissue (WAT) and inguinal WAT (iWAT) in mice. Lys208 acetylation modulated by transacetylase CREB-binding protein/p300 and deacetylase HDAC3 is required for glucose-induced reduction of proteasomal degradation and augmentation of protein stability of CREBZF. Glucose induces rectal temperature and thermogenesis in white adipose of control mice, which is further potentiated in adipose-specific CREBZF knockout (CREBZF FKO) mice. During cold exposure, CREBZF FKO mice display enhanced thermogenic gene expression, browning of iWAT, and adaptive thermogenesis. CREBZF associates with PGC-1α to repress thermogenic gene expression. Expression levels of CREBZF are negatively correlated with UCP1 in human adipose tissues and increased in WAT of obese ob/ob mice, which may underscore the potential role of CREBZF in the development of compromised thermogenic capability under hyperglycemic conditions. Our results reveal an important mechanism of glucose sensing and thermogenic inactivation through reversible acetylation.


Assuntos
Tecido Adiposo Marrom , Glucose , Camundongos , Humanos , Animais , Glucose/metabolismo , Tecido Adiposo Marrom/metabolismo , Acetilação , Tecido Adiposo Branco/metabolismo , Metabolismo Energético , Obesidade/genética , Obesidade/metabolismo , Termogênese/genética , Camundongos Endogâmicos C57BL , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(23): e2219419120, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252972

RESUMO

Prolyl hydroxylase domain (PHD) enzymes change HIF activity according to oxygen signal; whether it is regulated by other physiological conditions remains largely unknown. Here, we report that PHD3 is induced by fasting and regulates hepatic gluconeogenesis through interaction and hydroxylation of CRTC2. Pro129 and Pro615 hydroxylation of CRTC2 following PHD3 activation is necessary for its association with cAMP-response element binding protein (CREB) and nuclear translocation, and enhanced binding to promoters of gluconeogenic genes by fasting or forskolin. CRTC2 hydroxylation-stimulated gluconeogenic gene expression is independent of SIK-mediated phosphorylation of CRTC2. Liver-specific knockout of PHD3 (PHD3 LKO) or prolyl hydroxylase-deficient knockin mice (PHD3 KI) show attenuated fasting gluconeogenic genes, glycemia, and hepatic capacity to produce glucose during fasting or fed with high-fat, high-sucrose diet. Importantly, Pro615 hydroxylation of CRTC2 by PHD3 is increased in livers of fasted mice, diet-induced insulin resistance or genetically obese ob/ob mice, and humans with diabetes. These findings increase our understanding of molecular mechanisms linking protein hydroxylation to gluconeogenesis and may offer therapeutic potential for treating excessive gluconeogenesis, hyperglycemia, and type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Glucose , Humanos , Camundongos , Animais , Glucose/metabolismo , Prolina/metabolismo , Hidroxilação , Diabetes Mellitus Tipo 2/metabolismo , Fígado/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Gluconeogênese/fisiologia , Prolil Hidroxilases/metabolismo , Hepatócitos/metabolismo , Camundongos Endogâmicos C57BL
3.
Hepatology ; 78(5): 1492-1505, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36680394

RESUMO

BACKGROUND AND AIMS: NASH has emerged as a leading cause of chronic liver disease. However, the mechanisms that govern NASH fibrosis remain largely unknown. CREBZF is a CREB/ATF bZIP transcription factor that causes hepatic steatosis and metabolic defects in obesity. APPROACH AND RESULTS: Here, we show that CREBZF is a key mechanism of liver fibrosis checkpoint that promotes hepatocyte injury and exacerbates diet-induced NASH in mice. CREBZF deficiency attenuated liver injury, fibrosis, and inflammation in diet-induced mouse models of NASH. CREBZF increases HSC activation and fibrosis in a hepatocyte-autonomous manner by stimulating an extracellular matrix protein osteopontin, a key regulator of fibrosis. The inhibition of miR-6964-3p mediates CREBZF-induced production and secretion of osteopontin in hepatocytes. Adeno-associated virus -mediated rescue of osteopontin restored HSC activation, liver fibrosis, and NASH progression in CREBZF-deficient mice. Importantly, expression levels of CREBZF are increased in livers of diet-induced NASH mouse models and humans with NASH. CONCLUSIONS: Osteopontin signaling by CREBZF represents a previously unrecognized intrahepatic mechanism that triggers liver fibrosis and contributes to the severity of NASH.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Osteopontina , Animais , Humanos , Camundongos , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Modelos Animais de Doenças , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Fibrose , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/patologia , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Osteopontina/genética , Osteopontina/metabolismo
4.
Phys Rev Lett ; 132(2): 021401, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38277602

RESUMO

In recent years, there has been significant interest in the field of extended black hole thermodynamics, where the cosmological constant and/or other coupling parameters are treated as thermodynamic variables. Drawing inspiration from the Iyer-Wald formalism, which reveals the intrinsic and universal structure of conventional black hole thermodynamics, we illustrate that a proper extension of this formalism also unveils the underlying theoretical structure of extended black hole thermodynamics. As a remarkable consequence, for any gravitational theory described by a diffeomorphism invariant action, it is always possible to construct a consistent extended thermodynamics using this extended formalism.

5.
Acta Biochim Biophys Sin (Shanghai) ; 56(1): 106-113, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38151997

RESUMO

The regulation of various types of cell death may help to restore the normal physiological function of cells and play a protective role in sepsis. In the current study, we explore the role of programmed cell necrosis in sepsis and the underlying mechanisms. The septic rat model is established by Cecal-ligation and perforation (CLP), and the in vitro model is established by LPS in IEC-6 cells. Our results demonstrate that receptor-interacting protein 1 (RIP1) is significantly upregulated in the ileum of septic rats and LPS-treated IEC-6 cells at both the mRNA and protein levels. Nec-1, an inhibitor of RIP1, reduces the protein levels of RIP1, p-RIP3, and phosphorylated mixed-lineage kinase domain-like (MLKL) (serine 358) and relieves intestinal injury in CLP-induced septic rats with decreased IL-6 and TNF-α levels. The in vitro experiments further reveal that LPS induces the colocalization of RIP1 and RIP3, resulting in the phosphorylation and translocation of MLKL to the plasma membrane in IEC-6 cells. LPS also facilitates ROS production in IEC-6 cells, but this effect is further reversed by Nec-1, si-RIP1 and si-RIP3. Furthermore, LPS-induced necrosis in IEC-6 cells is counteracted by NAC. Thus, we conclude that RIP1/RIP3-dependent programmed cell necrosis participates in intestinal injury in sepsis and may be associated with RIP1/RIP3-mediated ROS.


Assuntos
Lipopolissacarídeos , Sepse , Ratos , Animais , Espécies Reativas de Oxigênio/metabolismo , Lipopolissacarídeos/toxicidade , Necrose/metabolismo , Apoptose , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Sepse/complicações
6.
Chem Rev ; 121(13): 7468-7529, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34024093

RESUMO

Drug development is a long process whose main content includes drug synthesis, drug delivery, and drug evaluation. Compared with conventional drug development procedures, microfluidics has emerged as a revolutionary technology in that it offers a miniaturized and highly controllable environment for bio(chemical) reactions to take place. It is also compatible with analytical strategies to implement integrated and high-throughput screening and evaluations. In this review, we provide a comprehensive summary of the entire microfluidics-based drug development system, from drug synthesis to drug evaluation. The challenges in the current status and the prospects for future development are also discussed. We believe that this review will promote communications throughout diversified scientific and engineering communities that will continue contributing to this burgeoning field.


Assuntos
Desenvolvimento de Medicamentos , Microfluídica , Preparações Farmacêuticas/síntese química , Animais , Humanos
7.
Hepatology ; 74(1): 116-132, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33236445

RESUMO

BACKGROUND ANDS AIMS: NAFLD is associated with elevation of many cytokines, particularly IL-6; however, the role of IL-6 in NAFLD remains obscure. The aim of this study was to examine how myeloid-specific IL-6 signaling affects NAFLD by the regulation of antifibrotic microRNA-223 (miR-223) in myeloid cells. APPROACH AND RESULTS: Patients with NAFLD or NASH and healthy controls were recruited, and serum IL-6 and soluble IL-6 receptor α (sIL-6Rα) were measured. Compared to controls, serum IL-6 and sIL-6Rα levels were elevated in NAFLD/NASH patients. IL-6 levels correlated positively with the number of circulating leukocytes and monocytes. The role of IL-6 in NAFLD was investigated in Il6 knockout (KO) and Il6 receptor A (Il6ra) conditional KO mice after high-fat diet (HFD) feeding. HFD-fed Il6 KO mice had worse liver injury and fibrosis, but less inflammation, compared to wild-type mice. Hepatocyte-specific Il6ra KO mice had more steatosis and liver injury, whereas myeloid-specific Il6ra KO mice had a lower number of hepatic infiltrating macrophages (IMs) and neutrophils with increased cell death of these cells, but greater liver fibrosis (LF), than WT mice. Mechanistically, the increased LF in HFD-fed, myeloid-specific Il6ra KO mice was attributable to the reduction of antifibrotic miR-223 and subsequent up-regulation of the miR-223 target gene, transcriptional activator with PDZ-binding motif (TAZ), a well-known factor to promote NASH fibrosis. In vitro, IL-6 treatment up-regulated exosome biogenesis-related genes and subsequently promoted macrophages to release miR-223-enriched exosomes that were able to reduce profibrotic TAZ expression in hepatocytes by exosomal transfer. Finally, serum IL-6 and miR-223 levels were elevated and correlated with each other in NAFLD patients. CONCLUSIONS: Myeloid-specific IL-6 signaling inhibits LF through exosomal transfer of antifibrotic miR-223 into hepatocytes, providing therapeutic targets for NAFLD therapy.


Assuntos
Interleucina-6/metabolismo , Cirrose Hepática/imunologia , MicroRNAs/metabolismo , Hepatopatia Gordurosa não Alcoólica/imunologia , Adulto , Animais , Biópsia , Estudos de Casos e Controles , Dieta Hiperlipídica , Exossomos/imunologia , Exossomos/metabolismo , Feminino , Regulação da Expressão Gênica/imunologia , Voluntários Saudáveis , Hepatócitos/patologia , Humanos , Interleucina-6/sangue , Interleucina-6/genética , Fígado/citologia , Fígado/patologia , Cirrose Hepática/sangue , Cirrose Hepática/genética , Cirrose Hepática/patologia , Masculino , Camundongos , Camundongos Knockout , MicroRNAs/sangue , Pessoa de Meia-Idade , Células Mieloides/citologia , Células Mieloides/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Estudos Prospectivos , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/genética
8.
Opt Express ; 30(26): 46236-46247, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558582

RESUMO

A design of a 1 × 2 multimode 3 dB optical power splitter using tapered couplers is proposed and investigated in this paper. As an example, a 1 × 2 splitter processing five-lowest order transverse-electric-polarized modes is designed and optimized by utilizing finite difference time domain method and particle swarm optimization algorithm. To verify the feasibility of this novel design, the optimized device is fabricated on a silicon-on-insulator platform. The coupling lengths of tapered couplers are respectively 6.5 µm, 6.0 µm, 3.5 µm, 5.0 µm, 5.0 µm, 7.5 µm, 6.0 µm, 5.0 µm, and 8.0 µm. Measurement results reveal that, for the fabricated splitter, the power uniformity varies from 0.041 to 0.88 dB, the crosstalk ranges from -23.96 to -14.12 dB, and the insertion loss changes from 0.089 to 1.50 dB within a bandwidth from 1520 to 1600 nm.

9.
Phys Rev Lett ; 129(19): 191101, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36399744

RESUMO

In this Letter, employing the generalized off-shell free energy, we treat black hole solutions as defects in the thermodynamic parameter space. The results show that the positive and negative winding numbers corresponding to the defects indicate the local thermodynamical stable and unstable black hole solutions, respectively. The topological number defined as the sum of the winding numbers for all the black hole branches at an arbitrary given temperature is found to be a universal number independent of the black hole parameters. Moreover, this topological number only depends on the thermodynamic asymptotic behaviors of the black hole temperature at small and large black hole limits. Different black hole systems are characterized by three classes via this topological number. This number could help us in better understanding the black hole thermodynamics and, further, shed new light on the fundamental nature of quantum gravity.

10.
Hepatology ; 71(4): 1421-1436, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31469186

RESUMO

BACKGROUND AND AIMS: STAT3, a member of the signal transducer and activator of transcription (STAT) family, is strongly associated with liver injury, inflammation, regeneration, and hepatocellular carcinoma development. However, the signals that regulate STAT3 activity are not completely understood. APPROACH AND RESULTS: Here we characterize CREB/ATF bZIP transcription factor CREBZF as a critical regulator of STAT3 in the hepatocyte to repress liver regeneration. We show that CREBZF deficiency stimulates the expression of the cyclin gene family and enhances liver regeneration after partial hepatectomy. Flow cytometry analysis reveals that CREBZF regulates cell cycle progression during liver regeneration in a hepatocyte-autonomous manner. Similar results were observed in another model of liver regeneration induced by intraperitoneal injection of carbon tetrachloride (CCl4 ). Mechanistically, CREBZF potently associates with the linker domain of STAT3 and represses its dimerization and transcriptional activity in vivo and in vitro. Importantly, hepatectomy-induced hyperactivation of cyclin D1 and liver regeneration in CREBZF liver-specific knockout mice was reversed by selective STAT3 inhibitor cucurbitacin I. In contrast, adeno-associated virus-mediated overexpression of CREBZF in the liver inhibits the expression of the cyclin gene family and attenuates liver regeneration in CCl4 -treated mice. CONCLUSIONS: These results characterize CREBZF as a coregulator of STAT3 to inhibit regenerative capacity, which may represent an essential cellular signal to maintain liver mass homeostasis. Therapeutic approaches to inhibit CREBZF may benefit the compromised liver during liver transplantation.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Regulação da Expressão Gênica , Regeneração Hepática/genética , Fígado/fisiologia , Fator de Transcrição STAT3/genética , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Tetracloreto de Carbono/toxicidade , Ciclo Celular/genética , Deleção de Genes , Hepatócitos/efeitos dos fármacos , Hepatócitos/fisiologia , Fígado/efeitos dos fármacos , Fígado/lesões , Redes e Vias Metabólicas , Camundongos , Camundongos Knockout
11.
Arterioscler Thromb Vasc Biol ; 40(6): e166-e179, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32349534

RESUMO

OBJECTIVE: Recent studies suggest that the P2Y12 (P2Y purinoceptor 12) receptor of vascular smooth muscle cells in atherosclerotic plaques aggravates atherosclerosis, and P2Y12 receptor inhibitors such as CDL (clopidogrel) may effectively treat atherosclerosis. It is imperative to identify an effective biomarker for reflecting the P2Y12 receptor expression on vascular smooth muscle cells in plaques. Approach and Results: We found that there was a positive correlation between the level of circulating sLRP1 (soluble low-density lipoprotein receptor-related protein 1) and the number of LRP1+ α-SMA+ (α-smooth muscle actin), P2Y12+, or P2Y12+ LRP1+ cells in plaques from apoE-/- mice fed a high-fat diet. Furthermore, activation of the P2Y12 receptor increased the expression and shedding of LRP1 in vascular smooth muscle cells by inhibiting cAMP (3'-5'-cyclic adenosine monophosphate)/PKA (protein kinase A)/SREBP-2 (sterol regulatory element binding transcription factor 2). Conversely, genetic knockdown or pharmacological inhibition of the P2Y12 receptor had the opposite effects. Additionally, CDL decreased the number of lesional LRP1+ α-SMA+ cells and the levels of circulating sLRP1 by activating cAMP/PKA/SREBP-2 in apoE-/- mice fed a high-fat diet. CONCLUSIONS: Our study suggests that sLRP1 may be a biomarker that reflects the P2Y12 receptor level in plaques and has the potential to be an indicator for administering P2Y12 receptor inhibitors for patients with atherosclerosis.


Assuntos
Biomarcadores/análise , Expressão Gênica , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/análise , Placa Aterosclerótica/metabolismo , Receptores Purinérgicos P2Y12/genética , Actinas/análise , Animais , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Apolipoproteínas E/fisiologia , Clopidogrel/farmacologia , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Dieta Hiperlipídica , Técnicas de Silenciamento de Genes , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/química , Músculo Liso Vascular/metabolismo , Placa Aterosclerótica/química , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2Y12/efeitos dos fármacos , Receptores Purinérgicos P2Y12/fisiologia , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo
12.
PLoS Genet ; 14(10): e1007695, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30286083

RESUMO

INDUCER OF CBF EXPRESSION 1 (ICE1) encodes a MYC-like basic helix-loop-helix (bHLH) transcription factor playing a critical role in plant responses to chilling and freezing stresses and leaf stomata development. However, no information connecting ICE1 and reproductive development has been reported. In this study, we show that ICE1 controls plant male fertility via impacting anther dehydration. The loss-of-function mutation in ICE1 gene in Arabidopsis caused anther indehiscence and decreased pollen viability as well as germination rate. Further analysis revealed that the anthers in the mutant of ICE1 (ice1-2) had the structure of stomium, though the epidermis did not shrink to dehisce. The anther indehiscence and influenced pollen viability as well as germination in ice1-2 were due to abnormal anther dehydration, for most of anthers dehisced with drought treatment and pollen grains from those dehydrated anthers had similar viability and germination rates compared with wild type. Accordingly, the sterility of ice1-2 could be rescued by ambient dehydration treatments. Likewise, the stomatal differentiation of ice1-2 anther epidermis was disrupted in a different manner compared with that in leaves. ICE1 specifically bound to MYC-recognition elements in the promoter of FAMA, a key regulator of guard cell differentiation, to activate FAMA expression. Transcriptome profiling in the anther tissues further exhibited ICE1-modulated genes associated with water transport and ion exchange in the anther. Together, this work reveals the key role of ICE1 in male fertility control and establishes a regulatory network mediated by ICE1 for stomata development and water movement in the anther.


Assuntos
Fatores de Transcrição/fisiologia , Arabidopsis/genética , Fertilidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Germinação , Pólen/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
J Perinat Neonatal Nurs ; 35(4): E50-E57, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34726656

RESUMO

Social media has become a powerful approach to disseminating evidence to knowledge users. The BSweet2Babies video was developed in multiple languages showing the effectiveness of sweet solutions, skin-to-skin care, and breastfeeding during newborn painful procedures. This study aimed to disseminate the BSweet2Babies video in Chinese through social media platform of WeChat in China; evaluate the reach, acceptability, and recommendation of the video; and assess viewers' previous knowledge and experience of using the 3 strategies and intention to use these strategies in the future. Multiple dissemination strategies were used to maximize views for a 6-month dissemination period. The video received 19 812 views, 4306 "thumbs," and 671 participants completed surveys. Of the survey respondents, 393 were parents. Most respondents did not know these strategies and did not use or help parents use any of them. More healthcare professionals than parents intended to use or advocate for sweet solutions and breastfeeding. More healthcare professionals rated that the 3 strategies were easy to apply in real-life situations, but more parents evaluated that the length of the video was too long. Social media in China can be a promising approach to disseminating evidence on neonatal procedural pain treatments to healthcare professionals and the public.


Assuntos
Dor Processual , Mídias Sociais , China , Feminino , Humanos , Recém-Nascido , Dor , Manejo da Dor , Dor Processual/prevenção & controle
14.
Sheng Li Xue Bao ; 73(5): 761-771, 2021 Oct 25.
Artigo em Zh | MEDLINE | ID: mdl-34708233

RESUMO

Nutrient overload-caused deregulation of glucose and lipid metabolism leads to insulin resistance and metabolic disorders, which increases the risk of several types of cancers. CREB/ATF bZIP transcription factor (CREBZF), a novel transcription factor of the ATF/CREB family, has emerged as a critical mechanism bridging the gap between metabolism and cell growth. CREBZF forms a heterodimer with other proteins and functions as a coregulator for gene expression. CREBZF deficiency in the liver attenuates hepatic steatosis in high fat diet-induced insulin-resistant mice, while the expression levels of CREBZF are increased in the livers of obese mice and humans with hepatic steatosis. Intriguingly, CREBZF also regulates cell proliferation and apoptosis via interaction with several transcription factors including STAT3, p53 and HCF-1. Knockout of CREBZF in hepatocytes results in enhanced cell cycle progression and proliferation capacity in mice. Here we highlight how the CREBZF signaling network contributes to the deregulation of metabolism and cell growth, and discuss the potential of targeting these molecules for the treatment of insulin resistance, diabetes, fatty liver disease and cancer.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica , Resistência à Insulina , Fígado , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Ciclo Celular , Proliferação de Células , Dieta Hiperlipídica , Hepatócitos , Metabolismo dos Lipídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais
15.
J Biol Chem ; 294(3): 772-782, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30429217

RESUMO

Autophagy is of key importance for eliminating aggregated proteins during the maintenance of cellular proteostasis in response to endoplasmic reticulum (ER) stress. However, the upstream signaling that mediates autophagy activation in response to ER stress is incompletely understood. In this study, in vivo and in vitro approaches were utilized that include gain- and loss-of-function assays and mouse livers and human cell lines with tunicamycin-induced pharmacological ER stress. We report that calreticulin, a quality control chaperone that binds to misfolded glycoproteins for refolding in the ER, is induced under ER stress. Calreticulin overexpression stimulated the formation of autophagosomes and increased autophagic flux. Interestingly, calreticulin was sufficient for attenuating ER stress in tunicamycin- or thapsigargin-treated HeLa cells, whereas lentivirus-mediated shRNA calreticulin knockdown exacerbated ER stress. Mechanistically, we noted that calreticulin induces autophagy by interacting with microtubule-associated protein 1A/1B-light chain 3 (LC3). Confocal microscopy revealed that the colocalization of calreticulin and LC3 at the autophagosome was enhanced under ER stress conditions. Importantly, a conserved LC3-interacting region was necessary for calreticulin-mediated stimulation of autophagy and for reducing ER stress. These findings indicate a calreticulin-based mechanism that couples ER stress to autophagy activation, which, in turn, attenuates cellular stress, likely by alleviating the formation of aberrantly folded proteins. Pharmacological or genetic approaches that activate calreticulin-autophagy signaling may have potential for managing ER stress and related cellular disorders.


Assuntos
Autofagossomos/metabolismo , Autofagia , Calreticulina/metabolismo , Estresse do Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Calreticulina/genética , Retículo Endoplasmático/genética , Células HEK293 , Células HeLa , Humanos , Proteínas Associadas aos Microtúbulos/genética
16.
Opt Lett ; 45(19): 5596-5599, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001956

RESUMO

In this Letter, a 1×3 polarization-insensitive optical power splitter based on cascaded tapered silicon waveguides is proposed and experimentally demonstrated on a silicon-on-insulator platform. By utilizing the particle swarm optimization algorithm and the finite difference time domain method, the structural parameters of the coupling regions are carefully designed to achieve polarization-insensitive property, compact size, low insertion loss, high uniformity, and broad bandwidth. The coupling length can be as short as 7.3 µm. Our measurement results show that, at 1550 nm, the insertion losses of the fabricated device operating in transverse electric (TE) and transverse magnetic (TM) polarizations are, respectively, 0.068 dB and 0.62 dB. Within a bandwidth from 1525 to 1575 nm, the insertion loss is lower than 0.82 dB and the uniformity is less than 1 dB for the fabricated device operating in TE polarization, while the fabricated device operating in TM polarization can have an insertion loss smaller than 1.50 dB and a uniformity lower than 1 dB from 1528 to 1582 nm.

17.
Bioorg Med Chem Lett ; 30(2): 126806, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31757667

RESUMO

Gaucher disease (GD) results from inherited mutations in the lysosomal enzyme ß-glucocerobrosidase (GCase). Currently available treatment options for Type 1 GD are not efficacious for treating neuronopathic Type 2 and 3 GD due to their inability to cross the blood-brain barrier. In an effort to identify small molecules which could be optimized for CNS penetration we identified tamoxifen from a high throughput phenotypic screen on Type 2 GD patient-derived fibroblasts which reversed the disease phenotype. Structure activity studies around this scaffold led to novel molecules that displayed improved potency, efficacy and reduced estrogenic/antiestrogenic activity compared to the original hits. Here we present the design, synthesis and structure activity relationships that led to the lead molecule Compound 31.


Assuntos
Fibroblastos/metabolismo , Doença de Gaucher/patologia , Bibliotecas de Moléculas Pequenas/química , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Doença de Gaucher/metabolismo , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Humanos , Concentração Inibidora 50 , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Fenótipo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade , Tamoxifeno/química , Tamoxifeno/metabolismo
18.
Int J Clin Oncol ; 25(4): 521-530, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31832882

RESUMO

BACKGROUND: Interleukin-22 (IL22) has been implicated in inflammation and tumorigenesis. The association between IL22 gene polymorphisms and cancer risk has been widely explored. However, the limited sample sizes of previous studies may produce inadequate statistical power and conflicting results, which calls for further investigations. In this study, we recruited a total of 1490 cancer patients (480 liver cancer patients, 550 lung cancer patients, and 460 gastric cancer patients) and 800 normal controls to explore the associations between IL22 gene polymorphisms (rs1179251, rs2227485, rs2227511, and rs2227473) and cancer risk. METHOD: The genotyping was performed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Sanger sequencing. RESULTS: Our results showed that none of the four IL22 gene polymorphisms was associated with the risk of liver, lung or gastric cancer in Hubei Han Chinese population. To improve the statistical strength, a meta-analysis was further conducted. The results further confirmed our present findings and showed that rs1179251, rs2227485, and rs2227473 were not associated with cancer risk in total or stratified analysis. CONCLUSION: Consequently, the rs1179251, rs2227485, rs2227511, and rs2227473 polymorphisms may not be associated with cancer risk. However, further investigations using larger samples in different ethnic populations are required.


Assuntos
Interleucinas/genética , Polimorfismo de Nucleotídeo Único , Idoso , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Neoplasias Hepáticas/genética , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/genética , Interleucina 22
19.
J Invertebr Pathol ; 169: 107296, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31778713

RESUMO

Bacillus thuringiensis Cry1Ai belongs to three-domain Cry toxins and only shows growth inhibition effects against the agricultural pest Helicoverpa armigera, although it exhibits high toxicity against the non-target insect Bombyx mori. In previous studies, loop2 and loop3 on domain II from Cry1Ah were found to be related to binding and high toxicity against H. armigera. However, toxicity for B. mori of Cry1Ai-h-loop2, obtained by replacing loop 2 from Cry1Ah into Cry1Ai, was not modified. In this study, to further characterize the role of loop2 and loop3 in Cry1Ai, all of the amino acids in these two loops were substituted with the same amount of alanine residues. The Cry1Ai-loop3 mutant exhibited significantly lower toxicity against B. mori, but the toxicity of the loop2 mutant was not significantly changed. Furthermore, the double-exchange mutant Cry1Ai-h-loop2&3, replacing loop2 and loop3 from Cry1Ah into Cry1Ai, showed decreased toxicity against B. mori related to Cry1Ai. In addition, we found that the binding affinity of Cry1Ai-h-loop2&3 with brush border membrane vesicles (BBMVs) from the midgut of B. mori was lower than that of Cry1Ai, which correlates with the reduced toxicity.


Assuntos
Toxinas de Bacillus thuringiensis/química , Bacillus thuringiensis/química , Proteínas de Bactérias/química , Bombyx/efeitos dos fármacos , Endotoxinas/química , Proteínas Hemolisinas/química , Larva/efeitos dos fármacos , Animais , Bacillus thuringiensis/genética , Bombyx/crescimento & desenvolvimento , Controle de Insetos , Larva/crescimento & desenvolvimento , Controle Biológico de Vetores , Domínios Proteicos
20.
Small ; 15(21): e1901254, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30997747

RESUMO

Microcarriers with oxygen-delivering capacity have attracted increasing interest in the field of tissue regeneration. Here, a kind of molybdenum disulfide quantum dots (MoS2 QDs) integrated responsive porous microcarriers with controllable oxygen-delivering ability for wound healing is presented. The specific gelatin methacryloyl (GelMa) porous microcarriers are derived from inverse opal microparticles which can be decorated with the oxygen-carrying protein hemoglobin. Because of their characteristic porous structure, interconnected nanochannels, and excellent biocompatibility, the resultant microcarriers could carry oxygen extensively and provide support for tissue repair physically and biologically. Besides, since the typical photothermal effect of 2D materials and their derived 2D QDs, the inverse opal particles integrated with MoS2 QDs are imparted with photo-responsive capacity, which makes them able to release oxygen photo-controllably. It is demonstrated that the designed microcarriers can promote the repair of abdominal wall defects effectively with their multifunctional features. These remarkable properties point to the potential value of the microcarriers in wound healing and tissue engineering.


Assuntos
Engenharia Tecidual/métodos , Oxigênio/administração & dosagem , Oxigênio/uso terapêutico , Porosidade , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
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