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1.
Braz J Biol ; 83: e242439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468507

RESUMO

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, is rich in polyphenols. Phenolic compounds exhibit several biological properties, which reflect on biomarkers such as biochemical parameters. In the present study, we evaluated the plasmatic levels of glucose, total cholesterol, HDL-cholesterol, triglycerides, and uric acid of Chinese hamsters fed for 45 days with a regular diet or cholesterol-enriched diet supplemented with a liquid extract obtained from P. cauliflora fruits residues standardized in ellagic acid and total phenolic compounds. The results showed that the concentrated extract obtained from jabuticaba residues increased the glycemia of animals fed with a regular diet and reduced the plasmatic uric acid levels of animals fed with a cholesterol-enriched diet. Since hyperuricemia is considered to be a significant risk factor of metabolic disorders and the principal pathological basis of gout, the liquid extract from P. cauliflora fruits residues would be a promising candidate as a novel hypouricaemic agent for further investigation.


Assuntos
Frutas , Myrtaceae , Animais , Cricetinae , Cricetulus , Fenóis , Extratos Vegetais
2.
Curr Protoc ; 1(9): e236, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34491634

RESUMO

Human artificial chromosomes (HACs) are considered promising tools for gene delivery, functional analyses, and gene therapy. HACs have the potential to overcome many of the problems caused by the use of viral-based gene transfer systems, such as limited cloning capacity, lack of copy number control, and insertional mutagenesis during integration into host chromosomes. The recently developed alphoidtetO -HAC has an advantage over other HAC vectors because it can be easily eliminated from dividing cells by inactivation of its conditional kinetochore. This provides a unique control mechanism to study phenotypes induced by a gene or genes carried on the HAC. The alphoidtetO -HAC has a single gene acceptor loxP site that allows insertion of an individual gene of interest or a cluster of genes of up to several Mb in size in Chinese hamster ovary (CHO) hybrid cells. The HACs carrying chromosomal copies of genes can then be transferred from these donor CHO cells to different recipient cells of interest via microcell-mediated chromosome transfer (MMCT). Here, we describe a detailed protocol for loading a gene of interest into the alphoidtetO -HAC vector and for the subsequent transfer of the HAC to recipient cells using an improved MMCT protocol. The original MMCT protocol includes treatment of donor cells with colcemid to induce micronucleation, wherein the HAC becomes surrounded with a nuclear membrane. That step is followed by disarrangement of the actin cytoskeleton using cytochalasin B to help induce microcell formation. The updated MMCT protocol, described here, features the replacement of colcemid and cytochalasin B with TN16 + griseofulvin and latrunculin B, respectively, and the use of collagen/laminin surface coating to promote attachment of metaphase cells to plates during micronuclei induction. These modifications increase the efficiency of HAC transfer to recipient cells ten fold. The improved MMCT protocol has been successfully tested on several recipient cell lines, including human mesenchymal stem cells and mouse embryonic stem cells. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Insertion of a BAC containing a gene of interest into a single loxP loading site of alphoidtetO -HAC in hamster CHO cells Basic Protocol 2: Microcell-mediated chromosome transfer from donor hamster CHO cells to mammalian cells.


Assuntos
Cromossomos Artificiais Humanos , Animais , Células CHO , Cromossomos Artificiais Humanos/genética , Cricetinae , Cricetulus , Técnicas de Transferência de Genes , Genômica , Humanos , Camundongos
3.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34445224

RESUMO

The tightly localized noradrenergic neurons (NA) in the locus coeruleus (LC) are well recognized as essential for focused arousal and novelty-oriented responses, while many children with autism spectrum disorder (ASD) exhibit diminished attention, engagement and orienting to exogenous stimuli. This has led to the hypothesis that atypical LC activity may be involved in ASD. Oxytocin (OXT) neurons and receptors are known to play an important role in social behavior, pair bonding and cognitive processes and are under investigation as a potential treatment for ASD. However, little is known about the neurotransmission from hypothalamic paraventricular (PVN) OXT neurons to LC NA neurons. In this study, we test, in male and female rats, whether PVN OXT neurons excite LC neurons, whether oxytocin is released and involved in this neurotransmission, and whether activation of PVN OXT neurons alters novel object recognition. Using "oxytocin sniffer cells" (CHO cells that express the human oxytocin receptor and a Ca indicator) we show that there is release of OXT from hypothalamic PVN OXT fibers in the LC. Optogenetic excitation of PVN OXT fibers excites LC NA neurons by co-release of OXT and glutamate, and this neurotransmission is greater in males than females. In male, but not in female animals, chemogenetic activation of PVN OXT neurons increases attention to novel objects.


Assuntos
Atenção , Locus Cerúleo/metabolismo , Neurônios/metabolismo , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Caracteres Sexuais , Transmissão Sináptica , Animais , Células CHO , Cricetulus , Feminino , Humanos , Masculino , Ocitocina/genética , Ratos , Receptores de Ocitocina/genética , Receptores de Ocitocina/metabolismo
4.
Vaccine ; 39(36): 5153-5161, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34362602

RESUMO

Members of the Developing Countries Vaccine Manufacturers' Network (DCVMN) have been actively engaged in the development of COVID-19 vaccine candidates. According to the WHO COVID-19 vaccine landscape updated on 29 December 2020, 18 member manufacturers had vaccines in preclinical or clinical trials, including three members with candidates in Phase III trials. Once successful candidates have been identified there will be a need for large scale vaccine manufacturing and supply, in which DCVMN member manufacturers can play a key role. In an internal survey in 2019, DCVMN members reported the capability to supply over 3.5 billion vaccine doses annually, and the provision of over 50 distinct vaccines to 170 countries. To describe the capabilities of DCVMN member manufacturers more precisely, a 121-question survey was circulated to 41 Network members. The survey assessed the manufacturers' capabilities in utilizing various technology platforms, cell cultures and filling technologies, in addition to their capacities for manufacturing drug products. The survey also evaluated manufacturers' preparedness to dedicate existing capacities to COVID-19 vaccine production. Results revealed that sampled manufacturers have strong capabilities for manufacturing vaccines based on recombinant technologies, particularly with mammalian cells, and microbial and yeast expression systems. Capabilities in utilizing cell cultures were distributed across multiple cell types, however manufacturing capacities with Vero and CHO cells were prominent. Formulating and filling findings illustrated further large-scale capabilities of Network members. Sampled manufacturers reported that over 50% of their capacity for vaccine manufacturing could be dedicated to COVID-19 vaccine production.


Assuntos
COVID-19 , Vacinas , Animais , Vacinas contra COVID-19 , Cricetinae , Cricetulus , Países em Desenvolvimento , Humanos , Imunização , SARS-CoV-2
5.
Environ Pollut ; 285: 117527, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34380225

RESUMO

2-Ethylhexyl diphenyl phosphate (EHDPP) is a common flame retardant and environmental pollutant, exposing humans with endocrinal disrupting potentials. Its mutagenicity, especially following metabolism, remains unclear. In this study, molecular docking analysis indicated that EHDPP was a potential substrate for several human CYP enzymes except for CYP1A1. Among V79-derived cell lines genetically engineered for the expression of each CYP, EHDPP (6 h exposure/18 h recovery) did not induce micronuclei in the V79 or V79-derived cells expressing human CYP1A1, however, it was positive in V79-derived cell lines expressing human CYP2E1, 3A4, and 2B6. In a human hepatoma (HepG2) cell line, EHDPP (48 h exposure) moderately induced micronuclei, which was blocked by 1-aminobenzotriazole (ABT, 60 µM, inhibitor of CYPs); pretreating HepG2 cells with bisphenol AF, another organic pollutant as inducer of CYPs (0.1 µM for 16 h), significantly potentiated micronuclei formation by EHDPP, threshold being decreased from 10 to 1.25 µM. This effect was blocked by ABT, drastically reduced by ketoconazole (inhibiting CYP3A expression/activity), and moderately inhibited by trans-1,2-dichloroethylene (selective CYP2E1 inhibitor). Immunofluorescent centromere protein B staining indicated that EHDPP-induced micronuclei in V79-derived cell lines expressing human CYP2E1 and 3A4 were predominantly centromere-negative, and that in HepG2 cells pretreated with bisphenol AF (for inducing multiple CYPs) were purely centromere-negative. In bisphenol AF-pretreated HepG2 cells EHDPP potently induced DNA breaks, as indicated by the comet assay and Western blot analysis of γ-H2AX. In conclusion, our study suggests that EHDPP is potently clastogenic, following activation by several human CYP enzymes, CYP3A4 being a major one.


Assuntos
Retardadores de Chama , Mutagênicos , Animais , Compostos de Bifenilo , Linhagem Celular , Cricetinae , Cricetulus , Retardadores de Chama/toxicidade , Humanos , Simulação de Acoplamento Molecular , Fosfatos
6.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360706

RESUMO

For the treatment of severe COVID-19, supplementation with human plasma-purified α-1 antitrypsin (AAT) to patients is currently considered. AAT inhibits host proteases that facilitate viral entry and possesses broad anti-inflammatory and immunomodulatory activities. Researchers have demonstrated that an interaction between SARS-CoV-2 spike protein (S) and lipopolysaccharides (LPS) enhances pro-inflammatory responses in vitro and in vivo. Hence, we wanted to understand the potential anti-inflammatory activities of plasma-derived and recombinant AAT (recAAT) in a model of human total peripheral blood mononuclear cells (PBMCs) exposed to a combination of CHO expressed trimeric spike protein and LPS, ex vivo. We confirmed that cytokine production was enhanced in PBMCs within six hours when low levels of LPS were combined with purified spike proteins ("spike"). In the presence of 0.5 mg/mL recAAT, however, LPS/spike-induced TNF-α and IL-1ß mRNA expression and protein release were significantly inhibited (by about 46-50%) relative to LPS/spike alone. Although without statistical significance, recAAT also reduced production of IL-6 and IL-8. Notably, under the same experimental conditions, the plasma-derived AAT preparation Respreeza (used in native and oxidized forms) did not show significant effects. Our findings imply that an early pro-inflammatory activation of human PBMCs is better controlled by the recombinant version of AAT than the human plasma-derived AAT used here. Considering the increasing clinical interest in AAT therapy as useful to ameliorate the hyper-inflammation seen during COVID-19 infection, different AAT preparations require careful evaluation.


Assuntos
Anti-Inflamatórios/farmacologia , Leucócitos Mononucleares/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , alfa 1-Antitripsina/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/imunologia , Células CHO , COVID-19/terapia , Células Cultivadas , Cricetulus , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/toxicidade , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , alfa 1-Antitripsina/química , alfa 1-Antitripsina/imunologia
7.
J Anim Sci ; 99(8)2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34337647

RESUMO

Chinese hamster ovary cell constructs expressing either the ß 1-, ß 2- or ß 3-adrenergic receptor (AR) were used to determine whether a novel ß-AR modulator, lubabegron fumarate (LUB; Experior, Elanco Animal Health) might exert greater potency for a specific ß-AR subtype. EC50 values calculated based on cAMP accumulation in dose response curves indicate that LUB is highly selective for the ß 3-AR subtype, with an EC50 of 6 × 10-9 M, with no detectible agonistic activity at the ß 2-AR. We hypothesized that the accumulation of lipolytic markers would reflect the agonist activity at each of the ß-receptor subtypes of the specific ligand; additionally, there would be differences in receptor subtype expression in subcutaneous (s.c.) and intrmuscular (i.m.) adipose tissues. Total RNA was extracted from adipose tissue samples and relative mRNA levels for ß 1-, ß2-, and ß 3-AR were measured using real-time quantitative polymerase chain reaction. Fresh s.c. and i.m. adipose tissue explants were incubated with isoproterenol hydrochloride (ISO; ß-AR pan-agonist), dobutamine hydrochloride (DOB; specific ß 1-AA), salbutamol sulfate (SAL; specific ß 2-AA), ractopamine hydrochloride (RAC), zilpaterol hydrochloride (ZIL), BRL-37344 (specific ß 3-agonist), or LUB for 30 min following preincubation with theophylline (inhibitor of phosphodiesterase). Relative mRNA amounts for ß 1-, ß 2-, and ß 3-AR were greater (P < 0.05) in s.c. than in i.m. adipose tissue. The most abundant ß-AR mRNA in both adipose tissues was the ß 2-AR (P < 0.05), with the ß 1- and ß 3-AR subtypes being minimally expressed in i.m. adipose tissue. ISO, RH, and ZH stimulated the release of glycerol and nonesterified fatty acid (NEFA) from s.c. adipose tissue, but these ß-AR ligands did not alter concentrations of these lipolytic markers in i.m. adipose tissue. LUB did not affect glycerol or NEFA concentrations in s.c. or i.m. adipose tissue, but attenuated (P < 0.05) the accumulation of cAMP mediated by the ß 1- and ß 2-AR ligands DOB and SAL in s.c. adipose tissue. Collectively, these data indicate that bovine i.m. adipose tissue is less responsive than s.c. adipose tissue to ß-adrenergic ligands, especially those that are agonists at the ß 1- and ß3-receptor subtypes. The minimal mRNA expression of the ß 1- and ß 3 subtypes in i.m. adipose tissue likely limits the response potential to agonists for these ß-AR subtypes.


Assuntos
Agonistas Adrenérgicos beta , Receptores Adrenérgicos beta , Tecido Adiposo , Agonistas Adrenérgicos beta/farmacologia , Animais , Células CHO , Bovinos , Cricetinae , Cricetulus , Fumaratos , Receptores Adrenérgicos beta/genética
8.
Nat Immunol ; 22(9): 1093-1106, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34282331

RESUMO

Neutrophils display distinct gene expression patters depending on their developmental stage, activation state and tissue microenvironment. To determine the transcription factor networks that shape these responses in a mouse model, we integrated transcriptional and chromatin analyses of neutrophils during acute inflammation. We showed active chromatin remodeling at two transition stages: bone marrow-to-blood and blood-to-tissue. Analysis of differentially accessible regions revealed distinct sets of putative transcription factors associated with control of neutrophil inflammatory responses. Using ex vivo and in vivo approaches, we confirmed that RUNX1 and KLF6 modulate neutrophil maturation, whereas RELB, IRF5 and JUNB drive neutrophil effector responses and RFX2 and RELB promote survival. Interfering with neutrophil activation by targeting one of these factors, JUNB, reduced pathological inflammation in a mouse model of myocardial infarction. Therefore, our study represents a blueprint for transcriptional control of neutrophil responses in acute inflammation and opens possibilities for stage-specific therapeutic modulation of neutrophil function in disease.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Inflamação/imunologia , Neutrófilos/imunologia , Ativação Transcricional/genética , Animais , Células CHO , Linhagem Celular , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Cricetulus , Feminino , Fatores Reguladores de Interferon/metabolismo , Fator 6 Semelhante a Kruppel/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/imunologia , Infarto do Miocárdio/patologia , Fatores de Transcrição de Fator Regulador X/metabolismo , Fator de Transcrição RelB/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética/genética
9.
Nat Commun ; 12(1): 4171, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234116

RESUMO

Here we report the pharmacologic blockade of voltage-gated sodium ion channels (NaVs) by a synthetic saxitoxin derivative affixed to a photocleavable protecting group. We demonstrate that a functionalized saxitoxin (STX-eac) enables exquisite spatiotemporal control of NaVs to interrupt action potentials in dissociated neurons and nerve fiber bundles. The photo-uncaged inhibitor (STX-ea) is a nanomolar potent, reversible binder of NaVs. We use STX-eac to reveal differential susceptibility of myelinated and unmyelinated axons in the corpus callosum to NaV-dependent alterations in action potential propagation, with unmyelinated axons preferentially showing reduced action potential fidelity under conditions of partial NaV block. These results validate STX-eac as a high precision tool for robust photocontrol of neuronal excitability and action potential generation.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Saxitoxina/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia , Animais , Axônios/efeitos dos fármacos , Axônios/metabolismo , Células CHO , Células Cultivadas , Corpo Caloso/citologia , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/metabolismo , Cricetulus , Embrião de Mamíferos , Feminino , Hipocampo/citologia , Masculino , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Técnicas de Patch-Clamp , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saxitoxina/análogos & derivados , Saxitoxina/efeitos da radiação , Análise de Célula Única , Análise Espaço-Temporal , Raios Ultravioleta , Bloqueadores do Canal de Sódio Disparado por Voltagem/efeitos da radiação
10.
Molecules ; 26(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206465

RESUMO

(1) Background: Two first-in-class racemic dopamine D1 receptor (D1R) positive allosteric modulator (PAM) chemotypes (1 and 2) were identified from a high-throughput screen. In particular, due to its selectivity for the D1R and reported lack of intrinsic activity, compound 2 shows promise as a starting point toward the development of small molecule allosteric modulators to ameliorate the cognitive deficits associated with some neuropsychiatric disease states; (2) Methods: Herein, we describe the enantioenrichment of optical isomers of 2 using chiral auxiliaries derived from (R)- and (S)-3-hydroxy-4,4-dimethyldihydrofuran-2(3H)-one (d- and l-pantolactone, respectively); (3) Results: We confirm both the racemate and enantiomers of 2 are active and selective for the D1R, but that the respective stereoisomers show a significant difference in their affinity and magnitude of positive allosteric cooperativity with dopamine; (4) Conclusions: These data warrant further investigation of asymmetric syntheses of optically pure analogues of 2 for the development of D1R PAMs with superior allosteric properties.


Assuntos
Dopamina , Receptores de Dopamina D1 , Regulação Alostérica , Animais , Células CHO , Cricetulus , Dopamina/análogos & derivados , Dopamina/química , Dopamina/farmacologia , Receptores de Dopamina D1/química , Receptores de Dopamina D1/metabolismo
11.
Front Cell Infect Microbiol ; 11: 614985, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249772

RESUMO

In a Plasmodium vivax infection, it was shown a proportionally increased on gametocyte distribution within the bone marrow aspirant, suggesting a role of this organ as a reservoir for this parasite stage. Here, we evaluated the ex vivo cytoadhesive capacity of P. vivax gametocytes to bone marrow endothelial cells (HBMEC) and investigated the involvement of some receptors in the cytoadhesion process by using transfected CHO cells (CHO-ICAM1, CHO-CD36 and CHO-VCAM), wild type (CHO-K1) or deficient in heparan and chondroitin sulfate (CHO-745). Ex-vivo cytoadhesion assays were performed using a total of 44 P. vivax isolates enriched in gametocyte stages by Percoll gradient in the different cell lines. The majority of isolates (88.9%) were able to adhere to HBMEC monolayer. ICAM1 seemed to be the sole receptor significantly involved. CD-36 was the receptor with higher adhesion rate, despite no significance was noticed when compared to CHO-745. We demonstrated that gametocyte P. vivax adheres ex vivo to bone marrow endothelial cells. Moreover, P. vivax gametocytes display the ability to adhere to all CHO cells investigated, especially to CHO-ICAM1. These findings bring insights to the comprehension of the role of the bone marrow as a P. vivax reservoir and the potential impact on parasite transmission to the vector.


Assuntos
Plasmodium falciparum , Plasmodium vivax , Animais , Medula Óssea , Cricetinae , Cricetulus , Células Endoteliais , Plasmodium vivax/genética
12.
Molecules ; 26(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206005

RESUMO

Phenanthroindolizidines, such as antofine and tylophorine, are a family of natural alkaloids isolated from different species of Asclepiadaceas. They are characterized by interesting biological activities, such as pronounced cytotoxicity against different human cancerous cell lines, including multidrug-resistant examples. Nonetheless, these derivatives are associated with severe neurotoxicity and loss of in vivo activity due to the highly lipophilic nature of the alkaloids. Here, we describe the development of highly polar prodrugs of antofine and tylophorine as hypoxia-targeted prodrugs. The developed quaternary ammonium salts of phenanthroindolizidines showed high chemical and metabolic stability and are predicted to have no penetration through the blood-brain barrier. The designed prodrugs displayed decreased cytotoxicity when tested under normoxic conditions. However, their cytotoxic activity considerably increased when tested under hypoxic conditions.


Assuntos
Alcaloides/química , Antineoplásicos/síntese química , Indóis/química , Indolizinas/química , Fenantrenos/química , Fenantrolinas/química , Pró-Fármacos/síntese química , Compostos de Amônio Quaternário/síntese química , Compostos de Amônio Quaternário/farmacologia , Hipóxia Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Células CHO , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Humanos , Células MCF-7 , Estrutura Molecular , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Compostos de Amônio Quaternário/química , Relação Estrutura-Atividade
13.
Int J Mol Sci ; 22(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207579

RESUMO

Biomanufacturing processes may be optimized by storing cell culture media at room temperature, but this is currently limited by their instability and change in color upon long-term storage. This study demonstrates that one of the critical contributing factors toward media browning is tryptophan. LC-MS technology was utilized to identify tryptophan degradation products, which are likely formed primarily from oxidation reactions. Several of the identified compounds were shown to contribute significantly to color in solutions but also to exhibit toxicity against CHO cells. A cell-culture-compatible antioxidant, a-ketoglutaric acid, was found to be an efficient cell culture media additive for stabilizing components against degradation, inhibiting the browning of media formulations, and decreasing ammonia production, thus providing a viable method for developing room-temperature stable cell culture media.


Assuntos
Meios de Cultura/química , Triptofano/metabolismo , Animais , Células CHO , Cricetulus , Oxirredução , Triptofano/análise
14.
Int J Mol Sci ; 22(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207662

RESUMO

p62/Sequestosome-1 (p62) is a multifunctional adaptor protein and is also a constant component of disease-associated protein aggregates, including Mallory-Denk bodies (MDBs), in steatohepatitis and hepatocellular carcinoma. We investigated the interaction of the two human p62 isoforms, p62-H1 (full-length isoform) and p62-H2 (partly devoid of PB1 domain), with keratins 8 and 18, the major components of MDBs. In human liver, p62-H2 is expressed two-fold higher compared to p62-H1 at the mRNA level and is present in slightly but not significantly higher concentrations at the protein level. Co-transfection studies in CHO-K1 cells, PLC/PRF/5 cells as well as p62- total-knockout and wild-type mouse fibroblasts revealed marked differences in the cytoplasmic distribution and aggregation behavior of the two p62 isoforms. Transfection-induced overexpression of p62-H2 generated large cytoplasmic aggregates in PLC/PRF/5 and CHO-K1 cells that mostly co-localized with transfected keratins resembling MDBs or (transfection without keratins) intracytoplasmic hyaline bodies. In fibroblasts, however, transfected p62-H2 was predominantly diffusely distributed in the cytoplasm. Aggregation of p62-H2 and p62ΔSH2 as well as the interaction with K8 (but not with K18) involves acquisition of cross-ß-sheet conformation as revealed by staining with luminescent conjugated oligothiophenes. These results indicate the importance of considering p62 isoforms in protein aggregation disease.


Assuntos
Queratinas/metabolismo , Agregados Proteicos , Proteína Sequestossoma-1/metabolismo , Animais , Células CHO , Cricetulus , Humanos , Queratinas/genética , Camundongos , Camundongos Knockout , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína Sequestossoma-1/genética
15.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202630

RESUMO

Serotonin is a neurotransmitter that plays a crucial role in the regulation of several behavioral and cognitive functions by binding to a number of different serotonin receptors present on the cell surface. We report here the synthesis and characterization of several novel fluorescent analogs of serotonin in which the fluorescent NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl) group is covalently attached to serotonin. The fluorescent ligands compete with the serotonin1A receptor specific radiolabeled agonist for binding to the receptor. Interestingly, these fluorescent ligands display a high environmental sensitivity of their fluorescence. Importantly, the human serotonin1A receptor stably expressed in CHO-K1 cells could be specifically labeled with one of the fluorescent ligands with minimal nonspecific labeling. Interestingly, we show by spectral imaging that the NBD-labeled ligand exhibits a red edge excitation shift (REES) of 29 nm when bound to the receptor, implying that it is localized in a restricted microenvironment. Taken together, our results show that NBD-labeled serotonin analogs offer an attractive fluorescent approach for elucidating the molecular environment of the serotonin binding site in serotonin receptors. In view of the multiple roles played by the serotonergic systems in the central and peripheral nervous systems, these fluorescent ligands would be useful in future studies involving serotonin receptors.


Assuntos
Azóis/química , Membrana Celular/química , Corantes Fluorescentes/química , Nitrobenzenos/química , Receptor 5-HT1A de Serotonina/química , Animais , Células CHO , Cricetulus , Humanos , Ligantes
16.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209670

RESUMO

The glycosaminoglycan, heparan sulphate (HS), orchestrates many developmental processes. Yet its biological role has not yet fully been elucidated. Small molecule chemical inhibitors can be used to perturb HS function and these compounds provide cheap alternatives to genetic manipulation methods. However, existing chemical inhibition methods for HS also interfere with chondroitin sulphate (CS), complicating data interpretation of HS function. Herein, a simple method for the selective inhibition of HS biosynthesis is described. Using endogenous metabolic sugar pathways, Ac4GalNAz produces UDP-GlcNAz, which can target HS synthesis. Cell treatment with Ac4GalNAz resulted in defective chain elongation of the polymer and decreased HS expression. Conversely, no adverse effect on CS production was observed. The inhibition was transient and dose-dependent, affording rescue of HS expression after removal of the unnatural azido sugar. The utility of inhibition is demonstrated in cell culture and in whole organisms, demonstrating that this small molecule can be used as a tool for HS inhibition in biological systems.


Assuntos
Vias Biossintéticas/efeitos dos fármacos , Sulfatos de Condroitina/biossíntese , Heparitina Sulfato/biossíntese , Animais , Células CHO , Metabolismo dos Carboidratos/efeitos dos fármacos , Sulfatos de Condroitina/química , Cricetulus , Descoberta de Drogas , Glicosaminoglicanos/biossíntese , Heparitina Sulfato/química
17.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206616

RESUMO

The biophysical properties of therapeutic antibodies influence their manufacturability, efficacy, and safety. To develop an anti-cancer antibody, we previously generated a human monoclonal antibody (Ab417) that specifically binds to L1 cell adhesion molecule with a high affinity, and we validated its anti-tumor activity and mechanism of action in human cholangiocarcinoma xenograft models. In the present study, we aimed to improve the biophysical properties of Ab417. We designed 20 variants of Ab417 with reduced aggregation propensity, less potential post-translational modification (PTM) motifs, and the lowest predicted immunogenicity using computational methods. Next, we constructed these variants to analyze their expression levels and antigen-binding activities. One variant (Ab612)-which contains six substitutions for reduced surface hydrophobicity, removal of PTM, and change to the germline residue-exhibited an increased expression level and antigen-binding activity compared to Ab417. In further studies, compared to Ab417, Ab612 showed improved biophysical properties, including reduced aggregation propensity, increased stability, higher purification yield, lower pI, higher affinity, and greater in vivo anti-tumor efficacy. Additionally, we generated a highly productive and stable research cell bank (RCB) and scaled up the production process to 50 L, yielding 6.6 g/L of Ab612. The RCB will be used for preclinical development of Ab612.


Assuntos
Anticorpos Monoclonais/química , Modelos Moleculares , Molécula L1 de Adesão de Célula Nervosa/química , Engenharia de Proteínas , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/farmacologia , Afinidade de Anticorpos , Células CHO , Fenômenos Químicos , Cricetulus , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Molécula L1 de Adesão de Célula Nervosa/antagonistas & inibidores , Engenharia de Proteínas/métodos , Estabilidade Proteica , Termodinâmica
18.
Anticancer Res ; 41(8): 3741-3746, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34281832

RESUMO

BACKGROUND/AIM: Reports on over-expression of the epidermal growth factor receptor (EGFR) in bladder cancer and its function in tumorigenesis have suggested to target this antigen. MATERIALS AND METHODS: We generated the targeted toxin EGF-PE40 consisting of the human epidermal growth factor (EGF) as the binding domain and PE40, a truncated version of Pseudomonas Exotoxin A, as the toxin domain. EGF-PE40 was tested on EGFR-expressing bladder cancer cells in view of binding via flow cytometry, and cytotoxicity via WST viability assay. Induction of apoptosis was examined by western blot. RESULTS: The targeted toxin specifically triggered cytotoxicity in the bladder cancer cells with 50% inhibitory concentration (IC50) values in the low nanomolar or picomolar range, and was about 1,250- to 1,500-fold more cytotoxic than the EGFR inhibitor erlotinib. Cytotoxicity of EGF-PE40 was based on the induction of apoptosis. CONCLUSION: EGF-PE40 represents a promising candidate for the future treatment of bladder cancer.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Fator de Crescimento Epidérmico/química , Neoplasias da Bexiga Urinária/tratamento farmacológico , ADP Ribose Transferases/química , Animais , Toxinas Bacterianas/química , Células CHO , Linhagem Celular Tumoral , Cricetulus , Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Exotoxinas/química , Humanos , Fatores de Virulência/química
19.
Life Sci ; 282: 119824, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34265361

RESUMO

AIM: Berberine (BBR) is an alkaloid extracted from Coptidis Rhizoma, also known as Huang-Lian. Huang-Lian has been used extensively in traditional Chinese medicine for the treatment of various diseases, including diabetes and dementia. Because Alzheimer's disease (AD) is a complex disease that involves various pathophysiological changes, the diverse neuroprotective effects of BBR may be useful for improving the brain's energy state at an early stage of the disease. MAIN METHODS: We performed extracellular flux and 1H NMR-based metabolic profiling analyses to investigate the effects of BBR on metabolic processes in these cells. Pioglitazone (PIO), a peroxisome proliferator-activated receptor-γ (PPARγ) agonist has been studied extensively for the treatment of AD. We explored the combination dosing effects of BBR and PIO in vitro, then leveraged computational methods to explain the experimental finding. KEY FINDINGS: BBR demonstrates potential in modulating the mitochondrial bioenergetics and attenuating dysfunction of the primary energy and glutathione metabolism pathways in an AD cell model. It also suppresses basal respiration and reduces the production of pro-inflammatory cytokines in activated microglial cells. Both experimental and computational observations indicate that BBR and PIO have comparable binding affinities to the PPARγ protein, suggesting both drugs may have some overlapping effects for AD. SIGNIFICANCE: BBR exerts beneficial effects on disrupted metabolic processes in amyloidogenic cells and activated microglial cells, which are important for preventing or delaying early-stage disease progression. The choice of BBR or PIO for AD treatment depends on their respective pharmacokinetic profiles, delivery, efficacy and safety, and warrants further study.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Berberina/farmacologia , Microglia/metabolismo , Mitocôndrias/metabolismo , Modelos Biológicos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Células CHO , Cricetulus , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Microglia/patologia , Mitocôndrias/patologia
20.
Nat Commun ; 12(1): 4540, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315875

RESUMO

The mTORC1 node plays a major role in autophagy modulation. We report a role of the ubiquitous Gαq subunit, a known transducer of plasma membrane G protein-coupled receptors signaling, as a core modulator of mTORC1 and autophagy. Cells lacking Gαq/11 display higher basal autophagy, enhanced autophagy induction upon different types of nutrient stress along with a decreased mTORC1 activation status. They are also unable to reactivate mTORC1 and thus inactivate ongoing autophagy upon nutrient recovery. Conversely, stimulation of Gαq/11 promotes sustained mTORC1 pathway activation and reversion of autophagy promoted by serum or amino acids removal. Gαq is present in autophagic compartments and lysosomes and is part of the mTORC1 multi-molecular complex, contributing to its assembly and activation via its nutrient status-sensitive interaction with p62, which displays features of a Gαq effector. Gαq emerges as a central regulator of the autophagy machinery required to maintain cellular homeostasis upon nutrient fluctuations.


Assuntos
Autofagia , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Transdução de Sinais , Animais , Células CHO , Cricetulus , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Células HEK293 , Humanos , Lisossomos/metabolismo , Masculino , Camundongos , Modelos Biológicos , Fenótipo , Ligação Proteica , Domínios Proteicos , Ratos Wistar , Proteína Regulatória Associada a mTOR/metabolismo , Proteína Sequestossoma-1/metabolismo
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