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1.
Neurochem Res ; 44(7): 1602-1612, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30911983

RESUMO

Pyruvate Kinase isozymes M2 (PKM2) is a glycolytic enzyme involved in glycolysis that decarboxylates phosphoenolpyruvate to pyruvate and generates ATP. PKM2 also plays a significant role in tumor growth, in cell division, angiogenesis, apoptosis and metastasis. In this study, we have investigated the role of PKM2 in cortical neurons which suffered hypoxic-ischemic encephalopathy (HIE) in newborn rats. Immunohistochemistry and Western blot analysis revealed the protein expression of PKM2 peaking at 24 h after HIE. Double immunofluorescence labeling showed that PKM2 was mainly located in the neurons of the ipsilateral cerebral cortex, not in astrocytes or microglia. The increased level of active caspase-3 and the decreased level of phosphorylated AKT (p-AKT) were consistent with the PKM2 expression. TUNEL staining assay showed that PKM2 may participate in neuronal apoptosis in the rat ipsilateral cerebral cortex. Silencing of PKM2 in primary cultures of cortical neurons using a specific siRNA reduced the expression of active caspase-3 and upregulated p-AKT expression. Taken together, the results indicate that PKM2 may be involved in neuronal apoptosis after HIE by a mechanism dependent on the inactivation of p-AKT.


Assuntos
Apoptose/fisiologia , Córtex Cerebral/fisiologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Neurônios/fisiologia , Piruvato Quinase/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/patologia , Caspase 3/metabolismo , Córtex Cerebral/patologia , Hipóxia-Isquemia Encefálica/patologia , Isoenzimas/genética , Isoenzimas/fisiologia , Neurônios/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Piruvato Quinase/genética , RNA Interferente Pequeno/genética , Ratos , Regulação para Cima
2.
Biol Cell ; 111(7): 187-197, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30866055

RESUMO

BACKGROUND INFORMATION: Poly(ADP-ribose) polymerase-1 (PARP-1) has been attributed to varied roles in DNA repair, cell cycle, cell death, etc. Our previous reports demonstrate the role of PARP-1 during Dictyostelium discoideum development by its constitutive downregulation as well as by PARP-1 ortholog, ADP ribosyl transferase 1 A (ADPRT1A) overexpression. The current study analyses and strengthens the function of ADPRT1A in multicellular morphogenesis of D. discoideum. ADPRT1A was knocked out, and its effect was studied on cAMP signalling, chemotaxis and development of D. discoideum. RESULTS: We report that ADPRT1A is essential in multicellular development of D. discoideum, particularly at the aggregation stage. Genetic alterations of ADPRT1A and chemical inhibition of its activity affects the intracellular and extracellular cAMP levels during aggregation along with chemotaxis. Exogenous cAMP pulses could rescue this defect in the ADPRT1A knockout (ADPRT1A KO). Expression analysis of genes involved in cAMP signalling reveals altered transcript levels of four essential genes (PDSA, REGA, ACAA and CARA). Moreover, ADPRT1A KO affects prespore- and prestalk-specific gene expression and prestalk tendency is favoured in the ADPRT1A KO. CONCLUSION: ADPRT1A plays a definite role in regulating developmental morphogenesis via cAMP signalling. SIGNIFICANCE: This study helps in understanding the role of PARP-1 in multicellular development and differentiation in higher complex organisms.


Assuntos
Quimiotaxia , Dictyostelium/crescimento & desenvolvimento , Poli(ADP-Ribose) Polimerase-1/fisiologia , Proteínas de Protozoários/fisiologia , AMP Cíclico/metabolismo , Dictyostelium/genética , Dictyostelium/fisiologia , Técnicas de Inativação de Genes , Isoenzimas/genética , Isoenzimas/fisiologia , Morfogênese , Poli(ADP-Ribose) Polimerase-1/genética , Proteínas de Protozoários/genética , Transdução de Sinais , Transcriptoma
3.
Acta Biochim Biophys Sin (Shanghai) ; 51(3): 323-330, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30721967

RESUMO

Protein phosphatase 1 isoforms α, ß, and γ (PP1α, PP1ß, and PP1γ) are highly homologous in the catalytic domains but have distinct subcellular localizations. In this study, we utilized both primary cell culture and knockout mice to investigate the isoform-specific roles of PP1s in the heart. In both neonatal and adult cardiac myocytes, PP1ß was mainly localized in the nucleus, compared to the predominant presence of PP1α and PP1γ in the cytoplasm. Adenovirus-mediated overexpression of PP1α led to decreased phosphorylation of phospholamban, which was not influenced by overexpression of either PP1ß or PP1γ. Interestingly, only cardiac-specific knockout of PP1ß resulted in increased HDAC7 phosphorylation, consistent with the predominant nuclear localization of PP1ß. Functionally, deletion of either PP1 isoform resulted in reduced fractional shortening in aging mice, however only PP1ß deletion resulted in interstitial fibrosis in mice as early as 3 weeks of age. Deletion of neither PP1 isoform had any effect on pathological cardiac hypertrophy induced by 2 weeks of pressure overload stimulation. Together, our data suggest that PP1 isoforms have differential localizations to regulate the phosphorylation of their specific substrates for the physiological function in the heart.


Assuntos
Miócitos Cardíacos/enzimologia , Proteína Fosfatase 1/fisiologia , Animais , Células Cultivadas , Feminino , Coração/fisiologia , Isoenzimas/fisiologia , Masculino , Camundongos , Fosforilação , Proteína Fosfatase 1/análise
4.
BMC Genomics ; 20(1): 138, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30767781

RESUMO

BACKGROUND: Carbonic anhydrase (CA) catalyzes the hydration of CO2 in the first biochemical step of C4 photosynthesis, and has been considered a potentially rate-limiting step when CO2 availability within a leaf is low. Previous work in Zea mays (maize) with a double knockout of the two highest-expressed ß-CA genes, CA1 and CA2, reduced total leaf CA activity to less than 3% of wild-type. Surprisingly, this did not limit photosynthesis in maize at ambient or higher CO2concentrations. However, the ca1ca2 mutants exhibited reduced rates of photosynthesis at sub-ambient CO2, and accumulated less biomass when grown under sub-ambient CO2 (9.2 Pa). To further clarify the importance of CA for C4 photosynthesis, we assessed gene expression changes in wild-type, ca1 and ca1ca2 mutants in response to changes in pCO2 from 920 to 9.2 Pa. RESULTS: Leaf samples from each genotype were collected for RNA-seq analysis at high CO2 and at two time points after the low CO2 transition, in order to identify early and longer-term responses to CO2 deprivation. Despite the existence of multiple isoforms of CA, no other CA genes were upregulated in CA mutants. Although photosynthetic genes were downregulated in response to low CO2, differential expression was not observed between genotypes. However, multiple indicators of carbon starvation were present in the mutants, including amino acid synthesis, carbohydrate metabolism, and sugar signaling. In particular, multiple genes previously implicated in low carbon stress such as asparagine synthetase, amino acid transporters, trehalose-6-phosphate synthase, as well as many transcription factors, were strongly upregulated. Furthermore, genes in the CO2 stomatal signaling pathway were differentially expressed in the CA mutants under low CO2. CONCLUSIONS: Using a transcriptomic approach, we showed that carbonic anhydrase mutants do not compensate for the lack of CA activity by upregulating other CA or photosynthetic genes, but rather experienced extreme carbon stress when grown under low CO2. Our results also support a role for CA in the CO2 stomatal signaling pathway. This study provides insight into the importance of CA for C4 photosynthesis and its role in stomatal signaling.


Assuntos
Dióxido de Carbono/metabolismo , Anidrases Carbônicas/genética , Genes de Plantas , Fotossíntese/genética , Estômatos de Plantas/metabolismo , Zea mays/enzimologia , Zea mays/genética , Alelos , Aquaporinas/metabolismo , Sequência de Bases , Metabolismo dos Carboidratos , Anidrases Carbônicas/fisiologia , Parede Celular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genótipo , Isoenzimas/genética , Isoenzimas/fisiologia , Óxido Nítrico/metabolismo , Folhas de Planta/metabolismo , Homologia de Sequência do Ácido Nucleico , Transdução de Sinais
5.
J Dermatol Sci ; 93(2): 101-108, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30660448

RESUMO

BACKGROUND: The epidermis possesses regenerative properties that become apparent only after wounding. Atypical protein kinase C (aPKC) isoforms aPKCζ and aPKCλ form a ternary complex with Par3 and Par6, and play crucial roles in establishing and maintaining epithelial cell polarity. The epidermal loss of aPKCλ results in progressive depletion of hair follicle stem cells. However, it is unclear whether aPKCs have equivalent activities in epidermal regeneration. OBJECTIVES: To clarify functional differences between aPKCζ and aPKCλ in cutaneous wound healing. METHODS: We compared cutaneous wound healing processes in vivo using mutant mice with genetic deletion of each aPKC isoform. We also analyzed functional differences between aPKCζ and aPKCλ in cell proliferation, directional cell migration, and formation of microtubules in vitro using primary keratinocytes established from each mutant mouse. RESULTS: Wound healing was significantly retarded in epidermis-specific aPKCλ knockout mice. In aPKCλ-deleted keratinocytes, the correct orientation of cell protrusions toward the wound was disrupted through the destabilization of Par6ß. The elongation of stabilized ß-tubulin was also deteriorated in aPKCλ-deleted keratinocytes, leading to defects in cell spreading. Conversely, wound healing and directional cell migration in aPKCζ-deleted mice were comparable to those in their control littermates. CONCLUSIONS: aPKCs are not functionally equivalent; aPKCλ, but not aPKCζ, plays a primary role in cutaneous wound healing.


Assuntos
Movimento Celular/fisiologia , Epiderme/lesões , Isoenzimas/fisiologia , Proteína Quinase C/fisiologia , Cicatrização/fisiologia , Animais , Polaridade Celular/fisiologia , Células Cultivadas , Epiderme/fisiologia , Queratinócitos/fisiologia , Camundongos , Camundongos Knockout , Modelos Animais , Cultura Primária de Células
6.
J Reprod Dev ; 65(2): 155-162, 2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-30662012

RESUMO

The mitochondrial sheath is composed of mitochondria that coil tightly around the midpiece of sperm flagellum. These mitochondria are recruited from the cytoplasm to the flagellum late in spermatogenesis. Initially, recruited mitochondria are spherical-shaped but then elongate laterally to become crescent-like in shape. Subsequently, crescent-like mitochondria elongate continuously to coil tightly around the flagellum. Recently, disorganization of the mitochondrial sheath was reported in Glycerol kinase 2 (Gk2) disrupted mice. To analyze the disorganization of the mitochondrial sheath further, we generated Gk2-deficient mice using the CRISPR/Cas9 system and observed sperm mitochondria in testis using a freeze-fracture method with scanning electron microscopy. Gk2-disrupted spermatids show abnormal localization of crescent-like mitochondria, in spite of the initial proper alignment of spherical mitochondria around the flagellum, which causes abnormal mitochondrial sheath formation leading to exposure of the outer dense fibers. These results indicate that GK2 is essential for proper arrangement of crescent-like mitochondria to form the mitochondrial sheath during mouse spermatogenesis.


Assuntos
Glicerol Quinase/fisiologia , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/genética , Cauda do Espermatozoide/metabolismo , Espermatogênese/fisiologia , Animais , Transporte Biológico/genética , Citoplasma/metabolismo , Feminino , Fertilização In Vitro/veterinária , Glicerol Quinase/genética , Isoenzimas/genética , Isoenzimas/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos ICR , Camundongos Knockout , Mitocôndrias/genética , Cauda do Espermatozoide/ultraestrutura , Espermatogênese/genética , Espermatozoides/citologia , Espermatozoides/metabolismo , Espermatozoides/ultraestrutura
7.
Cells ; 8(1)2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30621237

RESUMO

RAC1B is an alternatively spliced isoform of the monomeric GTPase RAC1. It differs from RAC1 by a 19 amino acid in frame insertion, termed exon 3b, resulting in an accelerated GDP/GTP-exchange and an impaired GTP-hydrolysis. Although RAC1B has been ascribed several protumorigenic functions such as cell cycle progression and apoptosis resistance, its role in malignant transformation, and other functions driving tumor progression like epithelial-mesenchymal transition, migration/invasion and metastasis are less clear. Insertion of exon 3b endows RAC1B with specific biochemical properties that, when compared to RAC1, encompass both loss-of-functions and gain-of-functions with respect to the type of upstream activators, downstream targets, and binding partners. In its extreme, this may result in RAC1B and RAC1 acting in an antagonistic fashion in regulating a specific cellular response with RAC1B behaving as an endogenous inhibitor of RAC1. In this review, we strive to provide the reader with a comprehensive overview, rather than critical discussions, on various aspects of RAC1B biology in eukaryotic cells.


Assuntos
Movimento Celular , Transformação Celular Neoplásica/metabolismo , Transição Epitelial-Mesenquimal , Metástase Neoplásica , Proteínas rac1 de Ligação ao GTP/fisiologia , Animais , Linhagem Celular Tumoral , Humanos , Isoenzimas/fisiologia , Camundongos , Transdução de Sinais
8.
Int J Radiat Biol ; 95(4): 408-426, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29913092

RESUMO

The anaerobic metabolism of glucose by cancer cells, even under well-oxygenated conditions, has been documented by Otto Warburg as early as 1927. Micro-environmental hypoxia and intracellular pathways activating the hypoxia-related gene response, shift cancer cell metabolism to anaerobic pathways. In the current review, we focus on a major enzyme involved in anaerobic transformation of pyruvate to lactate, namely lactate dehydrogenase 5 (LDH5). The value of LDH5 as a marker of prognosis of cancer patients, as a predictor of response to radiotherapy (RT) and chemotherapy and, finally, as a major target for cancer treatment and radio-sensitization is reported and discussed. Clinical, translational and experimental data supporting the uniqueness of the LDHA gene and its product LDH5 isoenzyme are summarized and future directions for a metabolic treatment of cancer are highlighted.


Assuntos
Glucose/metabolismo , L-Lactato Desidrogenase/fisiologia , Neoplasias/radioterapia , Anaerobiose , Humanos , Isoenzimas/fisiologia , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Tolerância a Radiação
9.
Sheng Li Xue Bao ; 70(5): 511-520, 2018 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-30377690

RESUMO

Hypoxic exposure activates hypoxia inducible factors (HIFs) to up-regulate the expression of its target genes. These genes encode glucose metabolism related proteins, such as glucose transporters (GLUTs) and glycolysis related enzymes, including lactate dehydrogenase A (LDHA) and aldolase A (ALDA). Therefore, HIFs participate in oxygenolysis of glucose and play an important role in mediating hypoxia response and weight loss. Exercise training influences fatty acid metabolism, insulin sensitivity and body energy balance through activating peroxisome proliferator-activated receptors (PPARs), which plays an active role in losing weight. In addition, hypoxic exposure or exercise training can activate energy sensor 5'-AMP activated protein kinase (AMPK) in cells and promote oxidation of glucose and fatty acid and weight loss. It has been shown that hypoxic training exerts a better effects on controlling weight, compared with either hypoxic exposure or exercise training alone. This paper reviewed synergistic interactions among HIFs, PPARs and AMPK under hypoxic training and proposed possible mechanisms of hypoxic training-induced weight loss via AMPK-HIFs axis or AMPK-PPARs axis, thus providing theoretical guidance for application of hypoxic training in weight control.


Assuntos
Proteínas Quinases Ativadas por AMP/fisiologia , Fator 1 Induzível por Hipóxia/fisiologia , Hipóxia , Receptores Ativados por Proliferador de Peroxissomo/fisiologia , Perda de Peso , Animais , Peso Corporal , Metabolismo Energético , Ácidos Graxos , Frutose-Bifosfato Aldolase/fisiologia , Glucose , Proteínas Facilitadoras de Transporte de Glucose/fisiologia , Humanos , Resistência à Insulina , Isoenzimas/fisiologia , L-Lactato Desidrogenase/fisiologia , Metabolismo dos Lipídeos , Oxirredução , Regulação para Cima
11.
J Plant Physiol ; 231: 31-40, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30212659

RESUMO

Rhamnogalacturonan I (RG-I) is a domain of plant cell wall pectin. The rhamnogalacturonan lyase (RGL) enzyme (EC 4.2.2.23) degrades RG-I by cleaving the α-1,4 glycosidic bonds located between the l-rhamnose and d-galacturonic residues of the main chain. While RGL's biochemical mode of action is well known, its effects on plant physiology remain unclear. To investigate the role of the RGL enzyme in plants, we have expressed the Solyc11g011300 gene under a constitutive promoter (CaMV35S) in tomato cv. 'Ohio 8245' and evaluated the expression of this and other RGL genes, enzymatic activity and alterations in vegetative tissue, and tomato physiology in transformed lines compared to the positive control (plants harboring the pCAMBIA2301 vector) and the isogenic line. The highest expression levels of the Solyc11g011300, Solyc04g076630, and Solyc04g076660 genes were observed in leaves and roots and at 10 and 20 days after anthesis (DAA). Transgenic lines exhibited lower RGL activity in leaves and roots and during fruit ripening, whereas higher activity was observed at 10, 20, and 30 DAA than in the isogenic line and positive control. Both transgenic lines showed a lower number of seeds and fruits, higher root length, and less pollen germination percentage and viability. In red ripe tomatoes, transgenic fruits showed greater firmness, longer shelf life, and reduced shriveling than did the isogenic line. Additionally, a delay of one week in fruit ripening in transgenic fruits was also recorded. Altogether, our data demonstrate that the Solyc11g011300 gene participates in pollen tube germination, fruit firmness, and the fruit senescence phenomena that impact postharvest shelf life.


Assuntos
Frutas/crescimento & desenvolvimento , Genes de Plantas/fisiologia , Lycopersicon esculentum/genética , Pectinas/metabolismo , Proteínas de Plantas/genética , Polissacarídeo-Liase/genética , Frutas/enzimologia , Frutas/metabolismo , Perfilação da Expressão Gênica , Isoenzimas/genética , Isoenzimas/metabolismo , Isoenzimas/fisiologia , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas , Pólen/genética , Pólen/metabolismo , Tubo Polínico/crescimento & desenvolvimento
12.
Hum Cell ; 31(4): 300-309, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30088225

RESUMO

Accumulating evidence has demonstrated that there is critical involvement of miRNAs in the initiation and progression of cancers. Here, we showed that miR-323a-3p was significantly down-regulated in osteosarcoma (OS) tissues and cell lines. Overexpression of miR-323a-3p decreased the cell viability, colon formation and induced the apoptosis of OS cells. Using bioinformatics analysis, lactate dehydrogenase A (LDHA) was predicted as one of the down-steam targets of miR-323a-3p. Highly expressed miR-323a-3p significantly decreased both the mRNA and protein levels of LDHA. Inverse correlation between the expression of LDHA and miR-323a-3p was observed in OS tissues. Consistent with the function of LDHA in glycolysis of cancer cells, overexpression of miR-323a-3p attenuated the lactate production of OS cells. These results demonstrated that miR-323a-3p suppressed the growth of OS cells via targeting LDHA and inhibited the glycolysis of OS. This study provides insight into the molecular mechanism of miR-323a-3p in regulating OS.


Assuntos
Expressão Gênica , Marcação de Genes , Glicólise/genética , L-Lactato Desidrogenase/genética , MicroRNAs/genética , MicroRNAs/fisiologia , Osteossarcoma/genética , Osteossarcoma/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Isoenzimas/fisiologia , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/fisiologia , Ácido Láctico/metabolismo , Osteossarcoma/enzimologia , Osteossarcoma/patologia , RNA Mensageiro/metabolismo
13.
Exp Eye Res ; 177: 50-54, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30059666

RESUMO

Melatonin plays an important role in the regulation of retinal functions, and previous studies have also reported that the action of melatonin on photoreceptors is mediated by melatonin receptor heterodimers. Furthermore, it has been reported that the melatonin-induced increase in the amplitude of the a- and b-wave is significantly blunted by inhibition of PKC. Previous work has also shown that PKCζ is present in the photoreceptors, thus suggesting that PCKζ may be implicated in the modulation of melatonin signaling in photoreceptors. To investigate the role PKCζ plays in the modulation of the melatonin effect on the scotopic ERG, mice were injected with melatonin and with specific inhibitors of different PKC isoforms. PKCζ knockout mice were also used in this study. PKCζ activation in photoreceptors following melatonin injection was also investigated with immunocytochemistry. Inhibition of PKCζ by PKCζ-pseudosubstrate inhibitor (20 µM) significantly reduced the melatonin-induced increase in the amplitude of the a- and b-wave. To further investigate the role of different PKCs in the modulation of the ERGs, we tested whether intra-vitreal injection of Enzastaurin (a potent inhibitor of PCKα, PKCß, PKCγ, and PKCε) has any effect on the melatonin-induced increase in the a- and b-wave of the scotopic ERGs. Enzastaurin (100 nM) did not prevent the melatonin-induced increase in the amplitude of the a-wave, thus suggesting that PCKα, PKCß, PKCγ, and PKCε are not involved in this phenomenon. Finally, our data indicated that, in mice lacking PKCζ, melatonin injection failed to increase the amplitude of the a- and b-waves of the scotopic ERGs. An increase in PKCζ phosphorylation in the photoreceptors was also observed by immunocytochemistry. Our data indicate that melatonin signaling does indeed use the PKCζ pathway to increase the amplitude of the a- and b-wave of the scotopic ERG.


Assuntos
Adaptação à Escuridão/fisiologia , Isoenzimas/fisiologia , Melatonina/farmacologia , Células Fotorreceptoras/efeitos dos fármacos , Proteína Quinase C/fisiologia , Receptores de Melatonina/fisiologia , Retina/efeitos dos fármacos , Análise de Variância , Animais , Adaptação à Escuridão/efeitos dos fármacos , Eletrorretinografia , Isoenzimas/antagonistas & inibidores , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase C/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
14.
Crit Rev Oncol Hematol ; 127: 50-55, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29891111

RESUMO

Lipoxygenases (LOXs) are dioxygenases that catalyze the peroxidation of linoleic acid (LA) or arachidonic acid (AA), in the presence of molecular oxygen. The existence of inflammatory component in the tumor microenvironment intimately links the LOXs to gastrointestinal (GI) cancer progression. Amongst the six-different human LOX-isoforms, 5-LOX is the most vital enzyme for leukotriene (LT) biosynthesis, which is the main inflammation intermediaries. As recent investigations have shown the association of 5-LOX with tumor metastasis, there has also been significant progress in discovering the function of 5-LOX pathway in GI cancer. Studies on GI cancer cells using the pharmacological drugs targeting 5-LOX pathway have shown antiproliferative and proapoptotic effects. Pharmacogenetic discoveries in other diseases have revealed strong heritable basis for the leukotriene pathway, which helps in exploring the mechanistic source of genetic alteration within the leukotriene pathway and offer insights into GI cancer pathogenesis and future prospects for treatment and prevention. This review recapitulates the current research status of 5-LOX activity in GI malignancies.


Assuntos
Araquidonato 5-Lipoxigenase/fisiologia , Neoplasias Gastrointestinais/etiologia , Neoplasias Gastrointestinais/patologia , Metabolismo dos Lipídeos/fisiologia , Animais , Progressão da Doença , Neoplasias Gastrointestinais/metabolismo , Humanos , Isoenzimas/fisiologia , Lipoxigenase/fisiologia
15.
Gene ; 666: 134-144, 2018 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-29733968

RESUMO

Elongase of very long-chain fatty acids 6 (ELOVL6) is a rate-limiting enzyme catalyzing elongation of saturated and monounsaturated long-chain fatty acid. Although functional characteristics of Elovl6 have been demonstrated in mammal, the role of elovl6 in fish remains unclear. In this study, we firstly cloned three isoforms of elovl6 (elovl6a, elovl6b and elovl6-like) from loach (Misgurnus anguillicaudatus). Molecular characterizations of the three elovl6 isoforms in loach and their expressions of early life stages and different tissues were then determined. We also functionally characterized the three elovl6 isoforms using heterologous expression in baker's yeast. Results obtained here showed the three elovl6 proteins in loach can elongate C16:0 and C16:1 to C18:0 and C18:1, respectively. At last, to confirm the role of three loach elovl6 isoforms for elongation of fatty acids in adaption to cold stress, differences in skin histological structures, body fatty acid compositions, expressions of four hepatic lipogenesis or lipolysis related genes, and expressions of the three elovl6 isoforms and their related gene uncoupling protein 1 (ucp1) in different tissues were investigated in the loach reared in two different water temperatures (28 °C and 4 °C) for ten days. Cold stress increased ratios of C18/C16 and C20:5n-3/C18:3n-3 in loach body, and induced expressions of hepatic acyl-CoA delta-9 desaturase 1 (scd1), sterol-regulator element-binding protein 1 (srebp1), carnitine palmitoyltransferase 1 (cpt1) and fatty acid synthase (fas). Meanwhile, significant differences were found in expressions of the three elovl6 isoforms in different tissues between 28 °C and 4 °C groups. Overall, this study suggests that the three elovl6 isoforms in loach have ability to elongate C16 to C18, and elovl6 proteins in loach may play a role in adaptation to cold stress.


Assuntos
Acetiltransferases/fisiologia , Resposta ao Choque Frio , Proteínas de Peixes/fisiologia , Termotolerância , Sequência de Aminoácidos , Animais , Cipriniformes , Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Isoenzimas/fisiologia , Fases de Leitura Aberta , Especificidade de Órgãos , Filogenia
16.
Breast Cancer ; 25(6): 698-705, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29845398

RESUMO

BACKGROUND: CD44 and aldehyde dehydrogenase 1 (ALDH1) has been reputed to be cancer stem cell (CSC) markers in breast cancer. Yet, the clinicopathologic and prognostic significance of these markers remain unclear. In this study, we have investigated the expression of these markers and their relation with conventional clinicopathologic tumor characteristic including molecular subtype. METHODS: CD44 and ALDH1 expression were investigated by immunohistochemistry in a series of 157 formalin-fixed paraffin-embedded breast cancer tissues. RESULTS: Overall, CD44 and ALDH1 are, respectively, detected in 33% (52 of 157) and 7% (10 of 157) of breast cancer cases. We also observed that CD44 expression was associated with histological grade (p = 0.005). For ALDH1, we found that its expression is more frequent with elderly women (> 50 years, p = 0.03). The investigation of relationship between the stem cell phenotype and breast cancer molecular subtype, revealed that CD44 and ALDH1 expression was more frequent in basal-like tumors (p = 0.005). Among the two cancer stem cell markers tested, ALDH1 showed a strong association with the basal marker EGFR (p = 0.05). CONCLUSIONS: These findings suggest that CD44 and ALDH1 play a role in the clinical behavior in breast cancer and might be interesting biomarkers and therapeutic targets.


Assuntos
Neoplasias da Mama/patologia , Receptores de Hialuronatos/análise , Isoenzimas/análise , Células-Tronco Neoplásicas/química , Retinal Desidrogenase/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Feminino , Humanos , Receptores de Hialuronatos/fisiologia , Isoenzimas/fisiologia , Pessoa de Meia-Idade , Retinal Desidrogenase/fisiologia
17.
Br J Cancer ; 118(7): 985-994, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29515258

RESUMO

BACKGROUND: Despite chemotherapy intensification, a subgroup of high-risk paediatric T-cell acute lymphoblastic leukemia (T-ALL) patients still experience treatment failure. In this context, we hypothesised that therapy resistance in T-ALL might involve aldo-keto reductase 1C (AKR1C) enzymes as previously reported for solid tumors. METHODS: Expression of NRF2-AKR1C signaling components has been analysed in paediatric T-ALL samples endowed with different treatment outcomes as well as in patient-derived xenografts of T-ALL. The effects of AKR1C enzyme modulation has been investigated in T-ALL cell lines and primary cultures by combining AKR1C inhibition, overexpression, and gene silencing approaches. RESULTS: We show that T-ALL cells overexpress AKR1C1-3 enzymes in therapy-resistant patients. We report that AKR1C1-3 enzymes play a role in the response to vincristine (VCR) treatment, also ex vivo in patient-derived xenografts. Moreover, we demonstrate that the modulation of AKR1C1-3 levels is sufficient to sensitise T-ALL cells to VCR. Finally, we show that T-ALL chemotherapeutics induce overactivation of AKR1C enzymes independent of therapy resistance, thus establishing a potential resistance loop during T-ALL combination treatment. CONCLUSIONS: Here, we demonstrate that expression and activity of AKR1C enzymes correlate with response to chemotherapeutics in T-ALL, posing AKR1C1-3 as potential targets for combination treatments during T-ALL therapy.


Assuntos
Aldo-Ceto Redutases/fisiologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , 20-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , 20-Hidroxiesteroide Desidrogenases/fisiologia , Idade de Início , Membro C3 da Família 1 de alfa-Ceto Redutase/antagonistas & inibidores , Membro C3 da Família 1 de alfa-Ceto Redutase/fisiologia , Aldo-Ceto Redutases/antagonistas & inibidores , Animais , Criança , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Hidroxiesteroide Desidrogenases/fisiologia , Isoenzimas/fisiologia , Acetato de Medroxiprogesterona/administração & dosagem , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Oxirredutases/antagonistas & inibidores , Oxirredutases/fisiologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Células Tumorais Cultivadas , Vincristina/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Am J Physiol Endocrinol Metab ; 314(6): E620-E629, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29438630

RESUMO

The distribution of Na/K-ATPase α-isoforms in skeletal muscle is unique, with α1 as the minor (15%) isoform and α2 comprising the bulk of the Na/K-ATPase pool. The acute and isoform-specific role of α2 in muscle performance and resistance to fatigue is well known, but the isoform-specific role of α1 has not been as thoroughly investigated. In vitro, we reported that α1 has a role in promoting cell growth that is not supported by α2. To assess whether α1 serves this isoform-specific trophic role in the skeletal muscle, we used Na/K-ATPase α1-haploinsufficient (α1+/-) mice. A 30% decrease of Na/K-ATPase α1 protein expression without change in α2 induced a modest yet significant decrease of 10% weight in the oxidative soleus muscle. In contrast, the mixed plantaris and glycolytic extensor digitorum longus weights were not significantly affected, likely because of their very low expression level of α1 compared with the soleus. The soleus mass reduction occurred without change in total Na/K-ATPase activity or glycogen metabolism. Serum analytes including K+, fat tissue mass, and exercise capacity were not altered in α1+/- mice. The impact of α1 content on soleus muscle mass is consistent with a Na/K-ATPase α1-specific role in skeletal muscle growth that cannot be fulfilled by α2. The preserved running capacity in α1+/- is in sharp contrast with previously reported consequences of genetic manipulation of α2. Taken together, these results lend further support to the concept of distinct isoform-specific functions of Na/K-ATPase α1 and α2 in skeletal muscle.


Assuntos
Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , ATPase Trocadora de Sódio-Potássio/fisiologia , Animais , Regulação Enzimológica da Expressão Gênica , Isoenzimas/genética , Isoenzimas/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Contração Muscular/fisiologia , Músculo Esquelético/patologia , Tamanho do Órgão/genética , Condicionamento Físico Animal , ATPase Trocadora de Sódio-Potássio/genética
19.
Nihon Eiseigaku Zasshi ; 73(1): 9-20, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-29386454

RESUMO

Unlike genetic alterations in other aldehyde dehydrogenase (ALDH) isozymes, a defective ALDH2 polymorphism (rs671), which is carried by almost half of East Asians, does not show a clear phenotype such as a shortened life span. However, impacts of a defective ALDH2 allele, ALDH2*2, on various disease risks have been reported. As ALDH2 is responsible for the detoxification of endogenous aldehydes, a negative effect of this polymorphism is predicted, but bidirectional effects have been actually observed and the mechanisms underlying such influences are often complex. One reason for this complexity may be the existence of compensatory aldehyde detoxification systems and the secondary effects of these systems. There are many issues to be addressed with regard to the ALDH2 polymorphism in the field of preventive medicine, including the following concerns. First, ALDH2 in the fetal stage plays a role in aldehyde detoxification; therefore, prenatal health effects of environmental aldehyde exposure are of concern for ALDH2*2-carrying fetuses. Second, ALDH2*2 carriers are at high risk of drinking-related cancers. However, their drinking habits result in less worsening of physiological findings, such as energy metabolism index and liver functions, compared with non-ALDH2*2 carriers, and therefore opportunities to detect excessive drinking can be lost. Third, personalized medicine such as personalized prescriptions for ALDH2*2 carriers will be required in the clinical setting, and accumulation of evidence is awaited. Lastly, since the ALDH2 polymorphism is not considered in workers' limits of exposure to aldehydes and their precursors, efforts to lower exposure levels beyond legal standards are required.


Assuntos
Aldeído-Desidrogenase Mitocondrial/genética , Aldeído-Desidrogenase Mitocondrial/fisiologia , Aldeídos/efeitos adversos , Aldeídos/metabolismo , Estudos de Associação Genética , Inativação Metabólica/genética , Saúde do Trabalhador , Polimorfismo Genético , Medicina Preventiva , Consumo de Bebidas Alcoólicas/genética , Feminino , Heterozigoto , Humanos , Isoenzimas/genética , Isoenzimas/fisiologia , Estilo de Vida , Exposição Materna/efeitos adversos , Troca Materno-Fetal , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/prevenção & controle , Gravidez , Risco , Estresse Fisiológico
20.
J Glaucoma ; 27 Suppl 1: S15-S19, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29419646

RESUMO

Lysyl oxidases (LOX) are copper-dependent enzymes that oxidize lysyl and hydroxylysyl residues in collagen and elastin, as a first step in the stabilization of these extracellular matrix proteins through the formation of covalent cross-linkages, an essential process for connective tissue maturation. Five different LOX enzymes have been identified in mammals, LOX and LOX-like (LOXL) 1 to 4, being genetically different protein products with a high degree of homology in the catalytic carboxy terminal end and a more variable amino terminal proregion. Intensive investigation in the last years has delineated the main biological functions of these enzymes and their involvement in several pathologies including fibrosis, cancer, and ocular disorders. This review article summarizes the major findings on the role of LOX isoforms, with particular focus on their contribution to the development and progression of human disorders.


Assuntos
Síndrome de Exfoliação/enzimologia , Glaucoma de Ângulo Aberto/enzimologia , Proteína-Lisina 6-Oxidase/fisiologia , Animais , Doenças Ósseas/enzimologia , Doenças Cardiovasculares/enzimologia , Humanos , Isoenzimas/fisiologia , Neoplasias/enzimologia
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