RESUMO
Rasmussen's encephalitis (RE) stands as a rare neurological disorder marked by progressive cerebral hemiatrophy and epilepsy resistant to medical treatment. Despite extensive study, the primary cause of RE remains elusive, while its histopathological features encompass cortical inflammation, neuronal degeneration, and gliosis. The underlying molecular mechanisms driving disease progression remain largely unexplored. In this case study, we present a patient with RE who underwent hemispherotomy and has remained seizure-free for over six months, experiencing gradual motor improvement. Furthermore, we conducted molecular analysis on the excised brain tissue, unveiling a decrease in the expression of cell-cycle-associated genes coupled with elevated levels of BDNF and TNF-α proteins. These findings suggest the potential involvement of cell cycle regulators in the progression of RE.
Assuntos
Encefalite , Humanos , Encefalite/genética , Encefalite/patologia , Encefalite/metabolismo , Masculino , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Encéfalo/patologia , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Córtex Cerebral/patologia , Córtex Cerebral/metabolismo , Feminino , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Ciclo Celular/genéticaRESUMO
Valosin-containing protein (VCP; aka p97), a member of the AAA (ATPases Associated with various cellular Activities) family, has been associated with a wide range of cellular functions. While previous evidence has shown its presence in mammalian sperm, our study unveils its function in mouse sperm. Notably, we found that mouse VCP does not undergo tyrosine phosphorylation during capacitation and exhibits distinct localization patterns. In the sperm head, it resides within the equatorial segment and, following acrosomal exocytosis, it is released and cleaved. In the flagellum, VCP is observed in the principal and midpiece. Furthermore, our research highlights a unique role for VCP in the cAMP/PKA pathway during capacitation. Pharmacological inhibition of sperm VCP led to reduced intracellular cAMP levels that resulted in decreased phosphorylation in PKA substrates and tyrosine residues and diminished fertilization competence. Our results show that in mouse sperm, VCP plays a pivotal role in regulating cAMP production, probably by the modulation of soluble adenylyl cyclase activity.
Assuntos
AMP Cíclico , Capacitação Espermática , Espermatozoides , Proteína com Valosina , Animais , Masculino , Capacitação Espermática/efeitos dos fármacos , Proteína com Valosina/metabolismo , Proteína com Valosina/genética , Espermatozoides/metabolismo , Camundongos , AMP Cíclico/metabolismo , Fosforilação , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Adenosina Trifosfatases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genéticaRESUMO
Breast cancer stands out as one of the most prevalent malignancies worldwide, necessitating a nuanced understanding of its molecular underpinnings for effective treatment. Hormone receptors in breast cancer cells substantially influence treatment strategies, dictating therapeutic approaches in clinical settings, serving as a guide for drug development, and aiming to enhance treatment specificity and efficacy. Natural compounds, such as curcumin, offer a diverse array of chemical structures with promising therapeutic potential. Despite curcumin's benefits, challenges like poor solubility and rapid metabolism have spurred the exploration of analogs. Here, we evaluated the efficacy of the curcumin analog NC2603 to induce cell cycle arrest in MCF-7 breast cancer cells and explored its molecular mechanisms. Our findings reveal potent inhibition of cell viability (IC50 = 5.6 µM) and greater specificity than doxorubicin toward MCF-7 vs. non-cancer HaCaT cells. Transcriptome analysis identified 12,055 modulated genes, most notably upregulation of GADD45A and downregulation of ESR1, implicating CDKN1A-mediated regulation of proliferation and cell cycle genes. We hypothesize that the curcumin analog by inducing GADD45A expression and repressing ESR1, triggers the expression of CDKN1A, which in turn downregulates the expression of many important genes of proliferation and the cell cycle. These insights advance our understanding of curcumin analogs' therapeutic potential, highlighting not just their role in treatment, but also the molecular pathways involved in their activity toward breast cancer cells.
Assuntos
Neoplasias da Mama , Pontos de Checagem do Ciclo Celular , Curcumina , Inibidor de Quinase Dependente de Ciclina p21 , Regulação Neoplásica da Expressão Gênica , Humanos , Curcumina/farmacologia , Curcumina/análogos & derivados , Neoplasias da Mama/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Células MCF-7 , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Receptor alfa de Estrogênio/metabolismo , Receptor alfa de Estrogênio/genética , Antineoplásicos/farmacologia , Proteínas GADD45RESUMO
The Hippo pathway, a signaling cascade involved in the regulation of organ size and several other processes, acts as a conduit between extracellular matrix (ECM) cues and cellular responses. We asked whether the basement membrane (BM), a specialized ECM component known to induce quiescence and differentiation in mammary epithelial cells, would regulate the localization, activity, and interactome of YAP, a Hippo pathway effector. To address this question, we used a broad range of experimental approaches, including 2D and 3D cultures of both mouse and human mammary epithelial cells, as well as the developing mouse mammary gland. In contrast to malignant cells, nontumoral cells cultured with a reconstituted BM (rBM) displayed higher concentrations of YAP in the cytoplasm. Incidentally, when in the nucleus of rBM-treated cells, YAP resided preferentially at the nuclear periphery. In agreement with our cell culture experiments, YAP exhibited cytoplasmic predominance in ductal cells of developing mammary epithelia, where a denser BM is found. Conversely, terminal end bud (TEB) cells with a thinner BM displayed higher nucleus-to-cytoplasm ratios of YAP. Bioinformatic analysis revealed that genes regulated by YAP were overrepresented in the transcriptomes of microdissected TEBs. Consistently, mouse epithelial cells exposed to the rBM expressed lower levels of YAP-regulated genes, although the protein level of YAP and Hippo components were slightly altered by the treatment. Mass spectrometry analysis identified a differential set of proteins interacting with YAP in cytoplasmic fractions of mouse epithelial cells in the absence or presence of rBM. In untreated cells, YAP interactants were enriched in processes related to ubiquitin-mediated proteolysis, whereas in cells exposed to rBM YAP interactants were mainly key proteins related to amino acid, amino sugar, and carbohydrate metabolism. Collectively, we unraveled that the BM induces YAP translocation or retention in the cytoplasm of nontumoral epithelial cells and that in the cytoplasm YAP seems to undertake novel functions in metabolic pathways.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Membrana Basal , Citoplasma , Células Epiteliais , Fatores de Transcrição , Proteínas de Sinalização YAP , Animais , Humanos , Camundongos , Células Epiteliais/metabolismo , Proteínas de Sinalização YAP/metabolismo , Feminino , Citoplasma/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Membrana Basal/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/citologia , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Glândulas Mamárias Humanas/metabolismo , Glândulas Mamárias Humanas/citologia , Núcleo Celular/metabolismo , Transdução de SinaisRESUMO
Hypothalamic proopiomelanocortin (POMC) neurons are sensors of signals that reflect the energy stored in the body. Inducing mild stress in proopiomelanocortin neurons protects them from the damage promoted by the consumption of a high-fat diet, mitigating the development of obesity; however, the cellular mechanisms behind these effects are unknown. Here, we induced mild stress in a proopiomelanocortin neuron cell line by inhibiting Crif1. In proopiomelanocortin neurons exposed to high levels of palmitate, the partial inhibition of Crif1 reverted the defects in mitochondrial respiration and ATP production; this was accompanied by improved mitochondrial fusion/fission cycling. Furthermore, the partial inhibition of Crif1 resulted in increased reactive oxygen species production, increased fatty acid oxidation, and reduced dependency on glucose for mitochondrial respiration. These changes were dependent on the activity of CPT-1. Thus, we identified a CPT-1-dependent metabolic shift toward greater utilization of fatty acids as substrates for respiration as the mechanism behind the protective effect of mild stress against palmitate-induced damage of proopiomelanocortin neurons.NEW & NOTEWORTHY Saturated fats can damage hypothalamic neurons resulting in positive energy balance, and this is mitigated by mild cellular stress; however, the mechanisms behind this protective effect are unknown. Using a proopiomelanocortin cell line, we show that under exposure to a high concentration of palmitate, the partial inhibition of the mitochondrial protein Crif1 results in protection due to a metabolic shift warranted by the increased expression and activity of the mitochondrial fatty acid transporter CPT-1.
Assuntos
Carnitina O-Palmitoiltransferase , Proteínas de Ciclo Celular , Ácidos Graxos , Mitocôndrias , Animais , Camundongos , Carnitina O-Palmitoiltransferase/metabolismo , Carnitina O-Palmitoiltransferase/genética , Linhagem Celular , Ácidos Graxos/metabolismo , Hipotálamo/metabolismo , Hipotálamo/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , Pró-Opiomelanocortina/genética , Espécies Reativas de Oxigênio/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismoRESUMO
Cyclin/cyclin-dependent kinase (CDK) heterodimers have multiple phosphorylation targets and may alter the activity of these targets. Proteins from different metabolic processes are among the phosphorylation targets, that is, enzymes of central carbon metabolism. This work explores the interaction of Cyc/CDK complex members with the glycolytic enzymes hexokinase 7 (HXK7) and glyceraldehyde-3-phosphate dehydrogenase (GAP). Both enzymes interacted steadily with CycD2;2, CycB2;1 and CDKA;1 but not with CDKB1;1. However, Cyc/CDKB1;1 complexes phosphorylated both enzymes, decreasing their activities. Treatment with a CDK-specific inhibitor (RO-3306) or with lambda phosphatase after kinase assay restored total HXK7 activity, but not GAP activity. In enzymatic assays, increasing concentrations of CDKB1;1, but not of CycD2;2, CycB2;1 or CycD2;2/CDKB1;1 complex, decreased GAP activity. Cell cycle regulators may modulate carbon channeling in glycolysis by two different mechanisms: Cyc/CDK-mediated phosphorylation of targets (e.g., HXK7; canonical mechanism) or by direct and transient interaction of the metabolic enzyme (e.g., GAP) with CDKB1;1 without a Cyc partner (alternative mechanism).
Assuntos
Proteínas de Ciclo Celular , Hexoquinase , Proteínas de Ciclo Celular/metabolismo , Zea mays/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Glicólise , Ciclo CelularRESUMO
Organisms have evolved a complex system, called the DNA damage response (DDR), which maintains genome integrity. The DDR is responsible for identifying and repairing a variety of lesions and alterations in DNA. DDR proteins coordinate DNA damage detection, cell cycle arrest, and repair, with many of these events regulated by protein phosphorylation. In the human proteome, 23 proteins contain the BRCT (BRCA1 C-Terminus domain) domain, a modular signaling domain that can bind phosphopeptides and mediate protein-protein interactions. BRCTs can be found as functional single units, tandem (tBRCT), triplet (tpBRCT), and quartet. Here we examine the evolution of the tpBRCT architecture present in TOPBP1 (DNA topoisomerase II binding protein 1) and ECT2 (epithelial cell transforming 2), and their respective interaction partners RAD9 (Cell cycle checkpoint control protein RAD9) and CYK-4 (Rac GTPase-activating protein 1), with a focus on the conservation of the phosphopeptide-binding residues. The pair TOPBP1-RAD9 arose with the Eukaryotes and ECT2-CYK-4 with the Eumetazoans. Triplet structural and functional characteristics were conserved in almost all organisms. The first unit of the triplet (BRCT0) is different from the other two BRCTs but conserved between orthologs for both TOPBP1 and ECT2. BRCT domain evolution simulations suggest a trend to retain the singlet or towards two or three BRCT copies per protein consistent with functional tBRCT and tpBRCT architectures. Our results shed light on the emergence of the function and architecture of multiple BRCT domain organizations and provide information about the evolution of the BRCT triplet. Knowledge of BRCT domain evolution can improve the understanding of DNA damage response mechanisms and signal transduction in DDR.
Assuntos
Proteína BRCA1 , Proteínas de Ciclo Celular , Humanos , Proteína BRCA1/metabolismo , Domínios Proteicos , Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Transdução de Sinais , Fosforilação , Ligação ProteicaRESUMO
BACKGROUND: Cancer stem cells (CSCs) have unique biological characteristics, including tumorigenicity, immortality, and chemoresistance. Colorectal CSCs have been identified and isolated from colorectal cancers by various methods. AKAP12, a scaffolding protein, is considered to act as a potential suppressor in colorectal cancer, but its role in CSCs remains unknown. In this study, we investigated the function of AKAP12 in Colorectal CSCs. METHODS: Herein, Colorectal CSCs were enriched by cell culture with a serum-free medium. CSC-associated characteristics were evaluated by Flow cytometry assay and qPCR. AKAP12 gene expression was regulated by lentiviral transfection assay. The tumorigenicity of AKAP12 in vivo by constructing a tumor xenograft model. The related pathways were explored by qPCR and Western blot. RESULTS: The depletion of AKAP12 reduced colony formation, sphere formation, and expression of stem cell markers in colorectal cancer cells, while its knockdown decreased the volume and weight of tumor xenografts in vivo. AKAP12 expression levels also affected the expression of stemness markers associated with STAT3, potentially via regulating the expression of protein kinase C. CONCLUSION: This study suggests Colorectal CSCs overexpress AKAP12 and maintain stem cell characteristics through the AKAP12/PKC/STAT3 pathway. AKAP12 may be an important therapeutic target for blocking the development of colorectal cancer in the field of cancer stem cells.
Assuntos
Neoplasias Colorretais , Humanos , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Fenótipo , Células-Tronco Neoplásicas/patologia , Proliferação de Células , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Proteínas de Ancoragem à Quinase A/metabolismo , Fator de Transcrição STAT3/genéticaRESUMO
Septins, often described as the fourth component of the cytoskeleton, are structural proteins found in a vast variety of living beings. They are related to small GTPases and thus, generally, present GTPase activity which may play an important (although incompletely understood) role in their organization and function. Septins polymerize into long non-polar filaments, in which each subunit interacts with two others by alternating interfaces, NC and G. In Saccharomyces cerevisiae four septins are organized in the following manner, [Cdc11-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11]n in order to form filaments. Although septins were originally discovered in yeast and much is known regarding their biochemistry and function, only limited structural information about them is currently available. Here we present crystal structures of Cdc3/Cdc10 which provide the first view of the physiological interfaces formed by yeast septins. The G-interface has properties which place it in between that formed by SEPT2/SEPT6 and SEPT7/SEPT3 in human filaments. Switch I from Cdc10 contributes significantly to the interface, whereas in Cdc3 it is largely disorded. However, the significant negative charge density of the latter suggests it may have a unique role. At the NC-interface, we describe an elegant means by which the sidechain of a glutamine from helix α0 imitates a peptide group in order to retain hydrogen-bond continuity at the kink between helices α5 and α6 in the neighbouring subunit, thereby justifying the conservation of the helical distortion. Its absence from Cdc11, along with this structure's other unusual features are critically discussed by comparison with Cdc3 and Cdc10.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Humanos , Saccharomyces cerevisiae/metabolismo , Septinas , Proteínas de Saccharomyces cerevisiae/química , Citoesqueleto/metabolismo , Proteínas de Ciclo Celular/metabolismoRESUMO
Trypanosoma cruzi has a complex life cycle consisting of four morphological and distinct biological stages. Although some authors suggest that T. cruzi primarily follows clonal reproduction, recent genomic and transcriptomic studies indicate an unorthodox capacity for recombination. We aimed to estimate the differential gene expression of 10 meiosis/homologous recombination-related genes during the T. cruzi life cycle, including epimastigotes, under two different types of stress (oxidative stress and pH changes). We performed RT-qPCR tests using novel-designed primers to estimate the differential gene expression (∆Ct and ∆∆Ct) of nine genes (SPO11, HAP2, RAD50, MRN complex, BRCA2, DMC1, MND1, and RPA1) and RAD51, which was previously reported. Our results show basal expression of all genes during the life cycle, indicating their hypothetical role in several cellular processes but with specific signatures of differential gene expression during the life cycle (HAP2, RPA, RAD50, BRCA2, MND1, and DMC1) and oxidative stress (RPA, MRE11, NBS1, BRCA2, MND1, and RAD51). Additionally, we found that the MRN complex has an independent level of expression in T. cruzi, with profiles of MRE11 and NBS1 upregulated in some stages. Recent studies on other trypanosomatids have highlighted the influence of HAP2 and RPA in recombination and hybridization. If T. cruzi uses the same repertoire of genes, our findings could suggest that metacyclogenesis may be the putative step that the parasite uses to undergo recombination. Likewise, our study reveals the differential profiles of genes expressed in response to oxidative and pH stress. Further studies are necessary to confirm our findings and understand the recombination mechanism in T. cruzi.