RESUMO
Maintaining intracellular redox balance is essential for the survival, antibody secretion, and mucosal immune homeostasis of immunoglobulin A (IgA) antibody-secreting cells (ASCs). However, the relationship between mitochondrial metabolic enzymes and the redox balance in ASCs has yet to be comprehensively studied. Our study unveils the pivotal role of mitochondrial enzyme PCK2 in regulating ASCs' redox balance and intestinal homeostasis. We discover that PCK2 loss, whether globally or in B cells, exacerbates dextran sodium sulphate (DSS)-induced colitis due to increased IgA ASC cell death and diminished antibody production. Mechanistically, the absence of PCK2 diverts glutamine into the TCA cycle, leading to heightened TCA flux and excessive mitochondrial reactive oxygen species (mtROS) production. In addition, PCK2 loss reduces glutamine availability for glutathione (GSH) synthesis, resulting in a decrease of total glutathione level. The elevated mtROS and reduced GSH expose ASCs to overwhelming oxidative stress, culminating in cell apoptosis. Crucially, we found that the mitochondria-targeted antioxidant Mitoquinone (Mito-Q) can mitigate the detrimental effects of PCK2 deficiency in IgA ASCs, thereby alleviating colitis in mice. Our findings highlight PCK2 as a key player in IgA ASC survival and provide a potential new target for colitis treatment.
Assuntos
Colite , Homeostase , Mitocôndrias , Estresse Oxidativo , Animais , Colite/induzido quimicamente , Colite/metabolismo , Colite/imunologia , Camundongos , Mitocôndrias/metabolismo , Imunoglobulina A/metabolismo , Sulfato de Dextrana , Camundongos Knockout , Células Produtoras de Anticorpos/imunologia , Células Produtoras de Anticorpos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Camundongos Endogâmicos C57BL , Glutationa/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/imunologia , Intestinos/imunologia , Apoptose , Modelos Animais de DoençasRESUMO
G protein-coupled receptor 50 (GPR50) belongs to the G protein-coupled receptor which is highly homologous with the sequence of melatonin receptor MT1 and MT2. GPR50 expression has previously been reported in many brain regions, like cortex, midbrain, pons, amygdala. But, the distribution of GPR50 in the hippocampus and cortex and the cell types expressing GPR50 is not yet clear. In this study, we examined the distribution of GPR50 in adult male mice by immunofluorescence. Our results showed that GPR50 was localized in the CA1-3 pyramidal cells and the granule cells of the dentate gyrus. GPR50 was also expressed in excitatory and inhibitory neurons. As inhibitory neurons also contain many types, we found that GPR50 was localized in some interneurons in which it was co-expressed with the calcium-binding proteins calbindin, calretinin, and parvalbumin. Besides, similar results were seen in the cortex. The widespread expression of GPR50 in the hippocampus and cortex suggests that GPR50 may be associated with synaptic plasticity and cognitive function.
Assuntos
Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Giro Denteado/metabolismo , Feminino , Imunofluorescência , Masculino , Camundongos Endogâmicos C57BL , Células Piramidais/metabolismoRESUMO
Peroxisomes account for ~35% of total H2O2 generation in mammalian tissues. Peroxisomal ACOX1 (acyl-CoA oxidase 1) is the first and rate-limiting enzyme in fatty acid ß-oxidation and a major producer of H2O2 ACOX1 dysfunction is linked to peroxisomal disorders and hepatocarcinogenesis. Here, we show that the deacetylase sirtuin 5 (SIRT5) is present in peroxisomes and that ACOX1 is a physiological substrate of SIRT5. Mechanistically, SIRT5-mediated desuccinylation inhibits ACOX1 activity by suppressing its active dimer formation in both cultured cells and mouse livers. Deletion of SIRT5 increases H2O2 production and oxidative DNA damage, which can be alleviated by ACOX1 knockdown. We show that SIRT5 downregulation is associated with increased succinylation and activity of ACOX1 and oxidative DNA damage response in hepatocellular carcinoma (HCC). Our study reveals a novel role of SIRT5 in inhibiting peroxisome-induced oxidative stress, in liver protection, and in suppressing HCC development.
Assuntos
Acil-CoA Oxidase/antagonistas & inibidores , Acil-CoA Oxidase/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Estresse Oxidativo , Sirtuínas/metabolismo , Acil-CoA Oxidase/genética , Animais , Dano ao DNA , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Peróxido de Hidrogênio , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Oxirredução , Peroxissomos/química , Prognóstico , Sirtuínas/genéticaRESUMO
Protein lysine acetylation is one of the major posttranslational modifications (PTMs) with several thousands of proteins identified to be acetylated in mammalian tissues. Mechanistic studies have revealed important functions of acetylation in the regulation of protein function. Much less is known on how the acetyltransferases themselves are regulated. In the current study, we discover that the Elongator protein 3 (ELP3) acetyltransferase is modified by tyrosine phosphorylation. We demonstrate that the anaplastic lymphoma kinase (ALK) is the major tyrosine kinase responsible for ELP3 tyrosine phosphorylation. ELP3 is phosphorylated in tumor cells expressing oncogenic NPM-ALK fusion protein. We further identify Tyr202 as the major ALK phosphorylation site in ELP3. Importantly, the introduction of Y202 phosphorylation mutant ELP3 into ALK-positive tumor cells reduced cell growth and impaired gene expression. Collectively, our study reveals a novel regulatory mechanism for ELP3, provides an example that acetyltransferase itself can be regulated by PTM, and suggests a potential target for ALK-positive cancer therapies.
Assuntos
Histona Acetiltransferases/metabolismo , Neoplasias/enzimologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Tirosina Quinases/metabolismo , Substituição de Aminoácidos , Células HCT116 , Células HEK293 , Histona Acetiltransferases/genética , Humanos , Mutação de Sentido Incorreto , Neoplasias/genética , Neoplasias/patologia , Proteínas do Tecido Nervoso/genética , Proteínas de Fusão Oncogênica/genética , Fosforilação , Proteínas Tirosina Quinases/genéticaRESUMO
Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme in the pentose phosphate pathway (PPP) and plays an essential role in the oxidative stress response by producing NADPH, the main intracellular reductant. G6PD deficiency is the most common human enzyme defect, affecting more than 400 million people worldwide. Here, we show that G6PD is negatively regulated by acetylation on lysine 403 (K403), an evolutionarily conserved residue. The K403 acetylated G6PD is incapable of forming active dimers and displays a complete loss of activity. Knockdown of G6PD sensitizes cells to oxidative stress, and re-expression of wild-type G6PD, but not the K403 acetylation mimetic mutant, rescues cells from oxidative injury. Moreover, we show that cells sense extracellular oxidative stimuli to decrease G6PD acetylation in a SIRT2-dependent manner. The SIRT2-mediated deacetylation and activation of G6PD stimulates PPP to supply cytosolic NADPH to counteract oxidative damage and protect mouse erythrocytes. We also identified KAT9/ELP3 as a potential acetyltransferase of G6PD. Our study uncovers a previously unknown mechanism by which acetylation negatively regulates G6PD activity to maintain cellular NADPH homeostasis during oxidative stress.
Assuntos
Sobrevivência Celular/fisiologia , Glucosefosfato Desidrogenase/metabolismo , Histona Acetiltransferases/metabolismo , Homeostase/fisiologia , NADP/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Estresse Oxidativo/fisiologia , Sirtuína 2/metabolismo , Acetilação , Animais , Técnicas de Silenciamento de Genes , Glucosefosfato Desidrogenase/genética , Proteínas de Fluorescência Verde , Células HEK293 , Humanos , Camundongos , RNA Interferente Pequeno/genéticaRESUMO
The thromboxane A2 receptor (TP) has been implicated in restenosis after vascular injury, which induces vascular smooth muscle cell (VSMC) migration and proliferation. However, the mechanism for this process is largely unknown. In this study, we report that TP signaling induces VSMC migration and proliferation through activating YAP/TAZ, two major downstream effectors of the Hippo signaling pathway. The TP-specific agonists [1S-[1α,2α(Z),3ß(1E,3S*),4 α]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid (I-BOP) and 9,11-dideoxy-9α,11α-methanoepoxy-prosta-5Z,13E-dien-1-oic acid (U-46619) induce YAP/TAZ activation in multiple cell lines, including VSMCs. YAP/TAZ activation induced by I-BOP is blocked by knockout of the receptor TP or knockdown of the downstream G proteins Gα12/13 Moreover, Rho inhibition or actin cytoskeleton disruption prevents I-BOP-induced YAP/TAZ activation. Importantly, TP activation promotes DNA synthesis and cell migration in VSMCs in a manner dependent on YAP/TAZ. Taken together, thromboxane A2 signaling activates YAP/TAZ to promote VSMC migration and proliferation, indicating YAP/TAZ as potential therapeutic targets for cardiovascular diseases.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fosfoproteínas/metabolismo , Transdução de Sinais/fisiologia , Tromboxano A2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Ácidos Graxos Insaturados/farmacologia , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/genética , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/metabolismo , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Fosfoproteínas/genética , Receptores de Tromboxano A2 e Prostaglandina H2/agonistas , Receptores de Tromboxano A2 e Prostaglandina H2/genética , Receptores de Tromboxano A2 e Prostaglandina H2/metabolismo , Tromboxano A2/genética , Transativadores , Fatores de Transcrição , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Proteínas de Sinalização YAPRESUMO
The Hippo pathway plays a major role in organ size control, and its dysregulation contributes to tumorigenesis. The major downstream effectors of the Hippo pathway are the YAP/TAZ transcription co-activators, which are phosphorylated and inhibited by the Hippo pathway kinase LATS1/2. Here, we report a novel mechanism of TAZ regulation by the tight junction protein PARD3. PARD3 promotes the interaction between PP1A and LATS1 to induce LATS1 dephosphorylation and inactivation, therefore leading to dephosphorylation and activation of TAZ. The cytoplasmic, but not the tight junction complex associated, PARD3 is responsible for TAZ regulation. Our study indicates a potential molecular basis for cell growth-promoting function of PARD3 by modulating the Hippo pathway signaling in response to cell contact and cell polarity signals.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Polaridade Celular , Regulação da Expressão Gênica , Células HEK293 , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Fosforilação , Transdução de Sinais , Proteínas de Junções Íntimas/genética , Transativadores , Fatores de Transcrição , Proteínas com Motivo de Ligação a PDZ com Coativador TranscricionalRESUMO
Neuroprotective effect of scorpion venom on Parkinson's disease (PD) has already been reported. The present study was aimed to investigate whether scorpion venom heat resistant peptide (SVHRP) could attenuate ultrastructural abnormalities in mitochondria and oxidative stress in midbrain neurons of early-stage PD model. The early-stage PD model was established by injecting 6-hydroxydopamine (6-OHDA) (20 µg/3 µL normal saline with 0.1% ascorbic acid) into the striatum of Sprague Dawley (SD) rats unilaterally. The rats were intraperitoneally administered with SVHRP (0.05 mg/kg per day) or vehicle (saline) for 1 week. Two weeks after 6-OHDA treatment, the rats received behavior tests for validation of model. Three weeks after 6-OHDA injection, the immunoreactivity of dopaminergic neurons were detected by immunohistochemistry staining, and the ultrastructure of neuronal mitochondria in midbrain was observed by electron microscope. In the meantime, the activities of monoamine oxidase-B (MAO-B), superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the mitochondria of the midbrain neurons, as well as the inhibitory ability of hydroxyl free radical and the antioxidant ability in the serum, were measured by corresponding kits. The results showed that 6-OHDA reduced the optical density of dopaminergic neurons, induced damage of mitochondrial ultrastructure of midbrain neurons, decreased SOD activity, increased MAO-B activity and MDA content, and reduced the antioxidant ability of the serum. SVHRP significantly reversed the previous harmful effects of 6-OHDA in early-stage PD model. These findings indicate that SVHRP may contribute to neuroprotection by preventing biochemical and ultrastructure damage changes which occur during early-stage PD.
Assuntos
Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Peptídeos/farmacologia , Venenos de Escorpião/farmacologia , Animais , Antioxidantes/metabolismo , Corpo Estriado , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Malondialdeído/metabolismo , Mesencéfalo/citologia , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Estresse Oxidativo , Oxidopamina , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismoRESUMO
Despite improvements in the early intervention of myocardial infarction (MI) in recent decades, left ventricular aneurysms (LVA) remain a major health concern, particularly in developing nations. The progression of MI can lead to the thinning of the myocardial wall and the formation of a ventricular wall bulge, characteristic of an LVA. Furthermore, cardiac magnetic resonance (CMR) has emerged as the gold standard for LVA diagnosis due to its superior imaging capabilities. Notably, surgical ventricular reconstruction (SVR) is an effective treatment for LVA, aiming to restore the normal volume and structure of the left ventricle, thereby improving cardiac function. However, the criteria for selecting patients for SVR treatment remains a subject of debate. This review focuses on the current understanding of surgical indications, procedures, and prognostic risk factors that influence outcomes in left ventricular reconstruction, highlighting the need for precise patient selection to optimize surgical benefits.
RESUMO
Ferroptosis is a specific form of cell death characterized by excessive accumulation of cellular lipid peroxides. Ferroptosis is closely associated with various diseases, inhibition of which may help alleviate multi-organ injury caused by ischemia-reperfusion and enhance the anti-tumor effect by promoting the immunity of T cells. However, clinical approved drugs targeting ferroptosis process remain rare. In this study, we unexpectedly found that (R)-crizotinib, the first-generation ALK inhibitor, has potent inhibitory activity against ferroptosis across various cell lines. Moreover, its chiral molecule (S)-crizotinib, which was considered to share no common targets with (R)-crizotinib, also suppresses ferroptosis with an efficacy similar to that of (R)-crizotinib. We further demonstrated that both crizotinib enantiomers inhibit ferroptosis independently of their known targets, but through a common mechanism involving the targeting of AGPAT3-mediated synthesis of ether-linked polyunsaturated fatty acids (PE-O-PUFA), which are known to promote lipid-ROS generation and ferroptosis. In line with their activity in cell lines, (R)-crizotinib and (S)-crizotinib effectively mitigate renal ischemia-reperfusion injury in mice. Furthermore, the two compounds also inhibit lipid-ROS accumulation in CD8+ T cells in draining lymph nodes of B16-F10 subcutaneous xenograft mice, thereby promoting anti-tumor effects. Collectively, our study firstly reports a common activity shared by (R)-crizotinib and (S)-crizotinib in ferroptosis regulation. As a clinically approved drug, (R)-crizotinib has well-established pharmacokinetics and safety, which makes it a promising candidate for repurposing. Given the current lack of FDA-approved ferroptosis inhibitors, our findings suggest therapeutically repurposing (R)-crizotinib as well as its enantiomer (S)-crizotinib for treating ferroptosis-related diseases.
RESUMO
OBJECTIVE: To observe the effect of acupuncture on the protein kinase R-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α (eIF2α) signaling pathway in the hippocampus of rats with post-traumatic stress disorder (PTSD), so as to explore the underlying mechanism of acupuncture in treating PTSD. METHODS: Twenty-eight SD rats were randomly divided into normal, model, acupuncture and sertraline groups, with 7 rats in each group. The PTSD model was established by single prolonged stress method. The next day after modeling, acupuncture was applied to "Baihui" (GV20) and "Dazhui" (GV14) of rats in the acupuncture group for 10 min, once a day for 7 days. Sertraline (10 mg/kg) was given by gavage to rats of the sertraline group daily for 7 days. The behavioral changes of rats were detected by elevated cross maze experiment and new object recognition experiment. The expression levels of PERK,phosphorylated(p)-PERK, eIF2α, p-eIF2α and activating transcription factor 4 (ATF4) proteins in hippocampus were detected by Western blot. The ultrastructure of hippocampal neurons was observed by transmission electron microscopy. RESULTS: Compared with the normal group, the percentage of times and retention time of entering the open arm of the elevated cross maze experiment, and new object recognition index were significantly decreased (P<0.01); the expression levels of p-PERK, p-eIF2α and ATF4 proteins in hippocampus were significantly increased (P<0.05) of rats in the model group. Compared with the model group, the percentage of times and retention time of entering the open arm, and new object recognition index were significantly increased (P<0.05ï¼P<0.01), the expression levels of p-PERK, p-eIF2α and ATF4 proteins in hippocampus were significantly decreased (P<0.05, P<0.01) of rats in the acupuncture and sertraline groups; the expression level of eIF2α protein was significantly decreased (P<0.05) in the sertraline group. Hippocampal neurons in the model group were damaged, the rough endoplasmic reticulum showed severe dilation, the mitochondrial cristae showed reduction or mild cavitation; compared with the model group, hippocampal neurons structural damage and the rough endoplasmic reticulum dilation were alleviatedï¼ and only some of the mitochondrial cristae decreased in the acupuncture and sertraline groups. CONCLUSION: Acupuncture can alleviate the anxiety behavior as well as the recognition and memory ability of PTSD rats, and its mechanism may be related to the inhibition of hippocampus PERK/eIF2α signaling pathway and the reduction of hippocampal neuron damage caused by endoplasmic reticulum stress.
Assuntos
Terapia por Acupuntura , Transtornos de Estresse Pós-Traumáticos , Animais , Ratos , Ratos Sprague-Dawley , Transtornos de Estresse Pós-Traumáticos/genética , Transtornos de Estresse Pós-Traumáticos/terapia , Proteínas Quinases , Sertralina , Retículo Endoplasmático , Hipocampo , Transdução de Sinais , Fator 4 Ativador da TranscriçãoRESUMO
Pathogens and inflammatory conditions rapidly induce the expression of immune-responsive gene 1 (IRG1) in cells of myeloid lineage. IRG1 encodes an aconitate decarboxylase (ACOD1) that produces the immunomodulatory metabolite itaconate (ITA). In addition to rapid intracellular accumulation, ITA is also secreted from the cell, but whether secreted ITA functions as a signaling molecule is unclear. Here, we identified ITA as an orthosteric agonist of the GPCR OXGR1, with an EC50 of approximately 0.3 mM, which was in the same range as the physiological concentration of extracellular ITA upon macrophage activation. ITA activated OXGR1 to induce Ca2+ mobilization, ERK phosphorylation, and endocytosis of the receptor. In a mouse model of pulmonary infection with bacterial Pseudomonas aeruginosa, ITA stimulated Oxgr1-dependent mucus secretion and transport in respiratory epithelium, the primary innate defense mechanism of the airway. Our study thus identifies ITA as a bona fide ligand for OXGR1 and the ITA/OXGR1 paracrine signaling pathway during the pulmonary innate immune response.
Assuntos
Depuração Mucociliar , Succinatos , Camundongos , Animais , Succinatos/farmacologia , Imunidade Inata , Mucosa RespiratóriaRESUMO
Immune-responsive gene 1 (IRG1) encodes aconitate decarboxylase (ACOD1) that catalyzes the production of itaconic acids (ITAs). The anti-inflammatory function of IRG1/ITA has been established in multiple pathogen models, but very little is known in cancer. Here, we show that IRG1 is expressed in tumor-associated macrophages (TAMs) in both human and mouse tumors. Mechanistically, tumor cells induce Irg1 expression in macrophages by activating NF-κB pathway, and ITA produced by ACOD1 inhibits TET DNA dioxygenases to dampen the expression of inflammatory genes and the infiltration of CD8+ T cells into tumor sites. Deletion of Irg1 in mice suppresses the growth of multiple tumor types and enhances the efficacy of anti-PD-(L)1 immunotherapy. Our study provides a proof of concept that ACOD1 is a potential target for immune-oncology drugs and IRG1-deficient macrophages represent a potent cell therapy strategy for cancer treatment even in pancreatic tumors that are resistant to T cell-based immunotherapy.
Assuntos
Neoplasias , Macrófagos Associados a Tumor , Humanos , Animais , Camundongos , Macrófagos Associados a Tumor/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Macrófagos/metabolismo , Imunoterapia , Neoplasias/genética , Neoplasias/terapia , Neoplasias/metabolismo , Hidroliases/genéticaRESUMO
BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae.
Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Hanseníase Multibacilar/genética , Hanseníase Paucibacilar/genética , Polimorfismo de Nucleotídeo Único , Idoso , Estudos de Casos e Controles , Feminino , Redes Reguladoras de Genes , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium leprae , Proteína Adaptadora de Sinalização NOD2/genética , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de SinaisRESUMO
OBJECTIVE: To observe the effect of acupuncture on endoplasmic reticulum stress-related molecules glucose regulated protein 78 kD (GRP78), C/EBP homologous protein (CHOP), cysteinyl aspartate specific proteinase-12 (Caspase-12) and cysteinyl aspartate specific proteinase-3 (Caspase-3)in the hippocampus of rats with post-traumatic stress disorder, so as to explore the possible mechanism of acupuncture in treating post-traumatic stress disorder (PTSD). METHODS: Twenty-eight SD rats were randomly divided into normal control, model, acupuncture and sertraline groups, with 7 rats in each group. The PTSD rat model was established by single prolonged stress. After modeling, acupuncture was applied to "Baihui" (GV20) and "Dazhui" (GV14) for rats of the acupuncture group for 10 min, once a day for 7 days. Sertraline (10 mg/kg) was given by gavage to rats of the sertraline group daily for 7 days. Rats' behavior was assessed by open field test and novelty-suppressed test. The mRNA expression levels of GRP78 and CHOP in the hippocampus were detected by real-time PCR. The expression le-vels of Caspase-12 and Caspase-3 in the hippocampus were detected by Western blot. RESULTS: Compared with the normal control group, the rearing and crossing times were decreased (P<0.05), the time remaining in the central zone and the total distance of movement were significantly reduced (P<0.01, P<0.05), the time of entering the central area for the first time was significantly increased (P<0.01), the latency of the novelty-suppressed feeding was significantly increased (P<0.05) in the model group, meanwhile the expression level of GRP78 and CHOP mRNAs, Caspase-12 and Caspase-3 proteins in the hippocampus were increased (P<0.05, P<0.01). In comparison with the model group, the crossing times, the time remaining in the central zone and total distance of movement were increased significantly (P<0.05, P<0.01), while the time of entering the central area for the first time, the expression levels of GRP78 and CHOP mRNAs, and Caspase-12 protein in the hippocampus were obviously decreased (P<0.05, P<0.01) in the acupuncture and sertraline groups. In addition, the rearing times were increased significantly (P<0.05), the latency of the novelty-suppressed feeding and the expression of Caspase-3 were decreased significantly (P<0.05) in the sertraline group than in the model group. CONCLUSION: Acupuncture can significantly down-regulate the expression of endoplasmic reticulum stress-related molecules GRP78, CHOP and Caspase-12 in PTSD rats, which may be one of the mechanisms of acupuncture in treating PTSD.
Assuntos
Terapia por Acupuntura , Transtornos de Estresse Pós-Traumáticos , Animais , Estresse do Retículo Endoplasmático/genética , Hipocampo/metabolismo , Ratos , Ratos Sprague-Dawley , Transtornos de Estresse Pós-Traumáticos/genética , Transtornos de Estresse Pós-Traumáticos/metabolismo , Transtornos de Estresse Pós-Traumáticos/terapiaRESUMO
TET2 (ten-eleven-translocation) protein is a Fe(II)- and α-ketoglutarate-dependent dioxygenase that catalyzes DNA demethylation to regulate gene expression. While TET2 gene is frequently mutated in hematological cancer, its enzymatic activity is also compromised in various solid tumors. Whether TET2 deficiency creates vulnerability for cancer cells has not been studied. Here we reported that TET2 deficiency is associated with the change of lipid metabolism processes in acute myeloid leukemia (AML) patient. We demonstrate that statins, the inhibitors of ß-Hydroxy ß-methylglutaryl-CoA (HMG-CoA) reductase and commonly used cholesterol-lowering medicines, significantly sensitize TET2 deficient tumor cells to apoptosis. TET2 directly regulates the expression of HMG-CoA synthase (HMGCS1) by catalyzing demethylation on its promoter region, and conversely TET2 deficiency leads to significant down-regulation of HMGCS1 expression and the mevalonate pathway. Consistently, overexpression of HMGCS1 in TET2-deficient cells rescues statin-induced apoptosis. We further reveal that decrease of geranylgeranyl diphosphate (GGPP), an intermediate metabolite in the mevalonate pathway, is responsible for statin-induced apoptosis. GGPP shortage abolishes normal membrane localization and function of multiple small GTPases, leading to cell dysfunction. Collectively, our study reveals a vulnerability in TET2 deficient tumor and a potential therapeutic strategy using an already approved safe medicine.
Assuntos
Anticolesterolemiantes , Dioxigenases , Inibidores de Hidroximetilglutaril-CoA Redutases , Neoplasias , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hidroximetilglutaril-CoA Sintase/genética , Ácido Mevalônico/metabolismo , Ácido Mevalônico/farmacologia , Apoptose , Anticolesterolemiantes/farmacologia , Neoplasias/metabolismo , Proteínas de Ligação a DNA/genéticaRESUMO
Increased glycolysis is a hallmark of tumor, which can provide tumor cells with energy and building blocks to promote cell proliferation. Recent studies have shown that not only the expression of glycolytic genes but also their subcellular localization undergoes a variety of changes to promote development of different types of tumors. In this study, we performed a comprehensive analysis of glycolysis and gluconeogenesis genes based on data from TCGA to identify those with significant tumor-promoting potential across 14 types of tumors. This analysis not only confirms genes that are known to be involved in tumorigenesis, but also reveals a significant correlation of triosephosphate isomerase 1 (TPI1) with poor prognosis, especially in lung adenocarcinoma (LUAD). TPI1 is a glycolytic enzyme that interconverts dihydroxyacetone phosphate (DHAP) to glyceraldehyde 3-phosphate (GAP). We confirm the upregulation of TPI1 expression in clinical LUAD samples and an inverse correlation with the overall patient survival. Knocking down of TPI1 in lung cancer cells significantly reduced cell migration, colony formation, and xenograft tumor growth. Surprisingly, we found that the oncogenic function of TPI1 depends on its translocation to cell nucleus rather than its catalytic activity. Significant accumulation of TPI1 in cell nucleus was observed in LUAD tumor tissues compared with the cytoplasm localization in adjacent normal tissues. Moreover, nuclear translocation of TPI1 is induced by extracellular stress (such as chemotherapy agents and peroxide), which facilitates the chemoresistance of cancer cells. Our study uncovers a novel function of the glycolytic enzyme TPI1 in the LUAD.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Carcinogênese/genética , Núcleo Celular/metabolismo , Proliferação de Células/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Glicólise/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Triose-Fosfato Isomerase/genética , Triose-Fosfato Isomerase/metabolismoRESUMO
Post-traumatic stress disorder (PTSD) is a kind of chronic mental disorder after severe traumatic events. In this paper, the author reviewed the development of clinical and mechanism research of acupuncture and moxibustion for treating PTSD in the past 5 years. Clinical studies have shown that acupuncture could alleviate the symptoms of PTSD, and is an effective therapy for PTSD. The underlying mechanisms may include regulating neural circuit, neurotransmitters and receptors expression, signal pathway, apoptosis, immune cytokines and endocannabinoid system, et al. It could provide scientific basis of acupuncture and moxibustion for treating PTSD, and provide references for further study.
Assuntos
Terapia por Acupuntura , Acupuntura , Moxibustão , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/terapiaRESUMO
Additional sex combs-like 1 (ASXL1) interacts with BRCA1-associated protein 1 (BAP1) deubiquitinase to oppose the polycomb repressive complex 1 (PRC1)-mediated histone H2A ubiquitylation. Germline BAP1 mutations are found in a spectrum of human malignancies, while ASXL1 mutations recurrently occur in myeloid neoplasm and are associated with poor prognosis. Nearly all ASXL1 mutations are heterozygous frameshift or nonsense mutations in the middle or to a less extent the C-terminal region, resulting in the production of C-terminally truncated mutant ASXL1 proteins. How ASXL1 regulates specific target genes and how the C-terminal truncation of ASXL1 promotes leukemogenesis are unclear. Here, we report that ASXL1 interacts with forkhead transcription factors FOXK1 and FOXK2 to regulate a subset of FOXK1/K2 target genes. We show that the C-terminally truncated mutant ASXL1 proteins are expressed at much higher levels than the wild-type protein in ASXL1 heterozygous leukemia cells, and lose the ability to interact with FOXK1/K2. Specific deletion of the mutant allele eliminates the expression of C-terminally truncated ASXL1 and increases the association of wild-type ASXL1 with BAP1, thereby restoring the expression of BAP1-ASXL1-FOXK1/K2 target genes, particularly those involved in glucose metabolism, oxygen sensing, and JAK-STAT3 signaling pathways. In addition to FOXK1/K2, we also identify other DNA-binding transcription regulators including transcription factors (TFs) which interact with wild-type ASXL1, but not C-terminally truncated mutant. Our results suggest that ASXL1 mutations result in neomorphic alleles that contribute to leukemogenesis at least in part through dominantly inhibiting the wild-type ASXL1 from interacting with BAP1 and thereby impairing the function of ASXL1-BAP1-TF in regulating target genes and leukemia cell growth.
Assuntos
Transformação Celular Neoplásica/metabolismo , Fatores de Transcrição Forkhead/genética , Regulação Leucêmica da Expressão Gênica , Proteínas Repressoras/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/patologia , Epigênese Genética , Fatores de Transcrição Forkhead/metabolismo , Glucose/metabolismo , Células HEK293 , Heterozigoto , Humanos , Janus Quinases/genética , Janus Quinases/metabolismo , Células K562 , Mutação , Oxigênio/metabolismo , Ligação Proteica , Proteínas Repressoras/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/metabolismoRESUMO
Evolutionarily conserved SCAN (named after SRE-ZBP, CTfin51, AW-1, and Number 18 cDNA)-domain-containing zinc finger transcription factors (ZSCAN) have been found in both mouse and human genomes. Zscan4 is transiently expressed during zygotic genome activation (ZGA) in preimplantation embryos and induced pluripotent stem cell (iPSC) reprogramming. However, little is known about the mechanism of Zscan4 underlying these processes of cell fate control. Here, we show that Zscan4f, a representative of ZSCAN proteins, is able to recruit Tet2 through its SCAN domain. The Zscan4f-Tet2 interaction promotes DNA demethylation and regulates the expression of target genes, particularly those encoding glycolytic enzymes and proteasome subunits. Zscan4f regulates metabolic rewiring, enhances proteasome function, and ultimately promotes iPSC generation. These results identify Zscan4f as an important partner of Tet2 in regulating target genes and promoting iPSC generation and suggest a possible and common mechanism shared by SCAN family transcription factors to recruit ten-eleven translocation (TET) DNA dioxygenases to regulate diverse cellular processes, including reprogramming.