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1.
Am J Physiol Renal Physiol ; 327(3): F373-F385, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38961847

RESUMO

Dietary potassium deficiency causes stimulation of sodium reabsorption leading to an increased risk in blood pressure elevation. The distal convoluted tubule (DCT) is the main rheostat linking plasma K+ levels to the activity of the Na-Cl cotransporter (NCC). This occurs through basolateral membrane potential sensing by inwardly rectifying K+ channels (Kir4.1/5.1); decrease in intracellular Cl-; activation of WNK4 and interaction and phosphorylation of STE20/SPS1-related proline/alanine-rich kinase (SPAK); binding of calcium-binding protein 39 (cab39) adaptor protein to SPAK, leading to its trafficking to the apical membrane; and SPAK binding, phosphorylation, and activation of NCC. As kidney-specific with-no-lysine kinase 1 (WNK1) isoform (KS-WNK1) is another participant in this pathway, we examined its function in NCC regulation. We eliminated KS-WNK1 specifically in the DCT and demonstrated increased expression of WNK4 and long WNK1 (L-WNK1) and increased phosphorylation of NCC. As in other KS-WNK1 models, the mice were not hyperkalemic. Although wild-type mice under low-dietary K+ conditions demonstrated increased NCC phosphorylation, the phosphorylation levels of the transporter, already high in KS-WNK1, did not change under the low-K+ diet. Thus, in the absence of KS-WNK1, the transporter lost its sensitivity to low plasma K+. We also show that under low K+ conditions, in the absence of KS-WNK1, there was no formation of WNK bodies. These bodies were observed in adjacent segments, not affected by the targeting of KS-WNK1. As our data are overall consistent with those of the global KS-WNK1 knockout, they indicate that the DCT is the predominant segment affecting the salt transport regulated by KS-WNK1.NEW & NOTEWORTHY In this paper, we show that KS-WNK1 is a critical component of the distal convoluted tubule (DCT) K+ switch pathway. Its deletion results in an inability of the DCT to sense changes in plasma potassium. Absence of KS-WNK1 leads to abnormally high levels of WNK4 and L-WNK1 in the DCT, resulting in increased Na-Cl phosphorylation and function. Our data are consistent with KS-WNK1 targeting WNK4 and L-WNK1 to degradation.


Assuntos
Túbulos Renais Distais , Proteínas Serina-Treonina Quinases , Membro 3 da Família 12 de Carreador de Soluto , Proteína Quinase 1 Deficiente de Lisina WNK , Animais , Masculino , Camundongos , Túbulos Renais Distais/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Potássio/metabolismo , Potássio/sangue , Potássio na Dieta/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Membro 3 da Família 12 de Carreador de Soluto/metabolismo , Membro 3 da Família 12 de Carreador de Soluto/genética , Proteína Quinase 1 Deficiente de Lisina WNK/metabolismo , Proteína Quinase 1 Deficiente de Lisina WNK/genética
2.
Biochem Biophys Res Commun ; 714: 149947, 2024 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-38657442

RESUMO

Here, we characterized the p.Arg583His (R583H) Kv7.1 mutation, identified in two unrelated families suffered from LQT syndrome. This mutation is located in the HС-HD linker of the cytoplasmic portion of the Kv7.1 channel. This linker, together with HD helix are responsible for binding the A-kinase anchoring protein 9 (AKAP9), Yotiao. We studied the electrophysiological characteristics of the mutated channel expressed in CHO-K1 along with KCNE1 subunit and Yotiao protein, using the whole-cell patch-clamp technique. We found that R583H mutation, even at the heterozygous state, impedes IKs activation. Molecular modeling showed that HС and HD helixes of the C-terminal part of Kv7.1 channel are swapped along the C-terminus length of the channel and that R583 position is exposed to the outer surface of HC-HD tandem coiled-coil. Interestingly, the adenylate cyclase activator, forskolin had a smaller effect on the mutant channel comparing with the WT protein, suggesting that R583H mutation may disrupt the interaction of the channel with the adaptor protein Yotiao and, therefore, may impair phosphorylation of the KCNQ1 channel.


Assuntos
Proteínas de Ancoragem à Quinase A , Proteínas do Citoesqueleto , Canal de Potássio KCNQ1 , Síndrome do QT Longo , Animais , Feminino , Humanos , Masculino , Proteínas de Ancoragem à Quinase A/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Proteínas de Ancoragem à Quinase A/química , Células CHO , Cricetulus , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Canal de Potássio KCNQ1/genética , Canal de Potássio KCNQ1/metabolismo , Canal de Potássio KCNQ1/química , Síndrome do QT Longo/genética , Síndrome do QT Longo/metabolismo , Modelos Moleculares , Mutação , Canais de Potássio de Abertura Dependente da Tensão da Membrana/química , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Ligação Proteica
3.
Biol Reprod ; 111(3): 516-528, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-38785325

RESUMO

Klinefelter syndrome (KS) is the most prevalent chromosomal disorder occurring in males. It is defined by an additional X chromosome, 47,XXY, resulting from errors in chromosomal segregation during parental gametogenesis. A major phenotype is impaired reproductive function, in the form of low testosterone and infertility. This review comprehensively examines the genetic and physiological factors contributing to infertility in KS, in addition to emergent assisted reproductive technologies, and the unique ethical challenges KS patients face when seeking infertility treatment. The pathology underlying KS is increased susceptibility for meiotic errors during spermatogenesis, resulting in aneuploid or even polyploid gametes. Specific genetic elements potentiating this susceptibility include polymorphisms in checkpoint genes regulating chromosomal synapsis and segregation. Physiologically, the additional sex chromosome also alters testicular endocrinology and metabolism by dysregulating interstitial and Sertoli cell function, collectively impairing normal sperm development. Additionally, epigenetic modifications like aberrant DNA methylation are being increasingly implicated in these disruptions. We also discuss assisted reproductive approaches leveraged in infertility management for KS patients. Application of assisted reproductive approaches, along with deep comprehension of the meiotic and endocrine disturbances precipitated by supernumerary X chromosomes, shows promise in enabling biological parenthood for KS individuals. This will require continued multidisciplinary collaboration between experts with background of genetics, physiology, ethics, and clinical reproductive medicine.


Assuntos
Infertilidade Masculina , Síndrome de Klinefelter , Síndrome de Klinefelter/genética , Humanos , Masculino , Infertilidade Masculina/genética , Infertilidade Masculina/etiologia , Técnicas de Reprodução Assistida , Espermatogênese/genética
4.
Brief Bioinform ; 23(2)2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35108356

RESUMO

Bacterial genomes are massively sequenced, and they provide valuable data to better know the complete set of genes of a species. The analysis of thousands of bacterial strains can identify both shared genes and those appearing only in the pathogenic ones. Current computational gene finders facilitate this task but often miss some existing genes. However, the present availability of different genomes from the same species is useful to estimate the selective pressure applied on genes of complete pangenomes. It may assist in evaluating gene predictions either by checking the certainty of a new gene or annotating it as a gene under positive selection. Here, we estimated the selective pressure of 19 271 genes that are part of the pangenome of the human opportunistic pathogen Acinetobacter baumannii and found that most genes in this bacterium are subject to negative selection. However, 23% of them showed values compatible with positive selection. These latter were mainly uncharacterized proteins or genes required to evade the host defence system including genes related to resistance and virulence whose changes may be favoured to acquire new functions. Finally, we evaluated the utility of measuring selection pressure in the detection of sequencing errors and the validation of gene prediction.


Assuntos
Acinetobacter baumannii , Genoma Bacteriano , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Bactérias/genética , Sequência de Bases , Humanos , Filogenia , Virulência/genética
5.
EMBO Rep ; 23(5): e54117, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35239998

RESUMO

Non-coding RNA (ncRNA) regulatory networks are emerging as critical regulators of gene expression. These intricate networks of ncRNA:ncRNA interactions modulate multiple cellular pathways and impact the development and progression of multiple diseases. Herpesviruses, including Kaposi's sarcoma-associated herpesvirus, are adept at utilising ncRNAs, encoding their own as well as dysregulating host ncRNAs to modulate virus gene expression and the host response to infection. Research has mainly focused on unidirectional ncRNA-mediated regulation of target protein-coding transcripts; however, we identify a novel host ncRNA regulatory network essential for KSHV lytic replication in B cells. KSHV-mediated upregulation of the host cell circRNA, circHIPK3, is a key component of this network, functioning as a competing endogenous RNA of miR-30c, leading to increased levels of the miR-30c target, DLL4. Dysregulation of this network highlights a novel mechanism of cell cycle control during KSHV lytic replication in B cells. Importantly, disruption at any point within this novel ncRNA regulatory network has a detrimental effect on KSHV lytic replication, highlighting the essential nature of this network and potential for therapeutic intervention.


Assuntos
Herpesvirus Humano 8 , MicroRNAs , Linfócitos B , Herpesvirus Humano 8/genética , MicroRNAs/genética , RNA Circular/genética , Regulação para Cima
6.
Bioorg Med Chem Lett ; 112: 129914, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39111728

RESUMO

Mitogen-activated protein kinase kinases (MAP2Ks) 1, 4, and 7 are potential targets for treating various diseases. Here, we solved the crystal structures of MAP2K1 and MAP2K4 complexed with covalent inhibitor 5Z-7-oxozeaenol (5Z7O). The elucidated structures showed that 5Z7O was non-covalently bound to the ATP binding site of MAP2K4, while it covalently attached to cysteine at the DFG-1 position of the deep ATP site of MAP2K1. In contrast, we previously showed that 5Z7O covalently binds to MAP2K7 via another cysteine on the solvent-accessible edge of the ATP site. Structural analyses and molecular dynamics calculations indicated that the configuration and mobility of conserved gatekeeper methionine located at the central ATP site regulated the binding and access of 5Z7O to the ATP site of MAP2Ks. These structural features provide clues for developing highly potent and selective inhibitors against MAP2Ks. Abbreviations: ATP, adenosine triphosphate; FDA, Food and Drug Administration; MAP2Ks, mitogen-activated protein kinase kinases; MD, molecular dynamics; NSCLC, non-small cell lung cancer; 5Z7O, 5Z-7-oxozeaenol; PDB, protein data bank; RMSD, root-mean-square deviation.


Assuntos
Trifosfato de Adenosina , Metionina , Inibidores de Proteínas Quinases , Zearalenona , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/síntese química , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/química , Humanos , Metionina/química , Metionina/metabolismo , Sítios de Ligação , Zearalenona/análogos & derivados , Zearalenona/química , Zearalenona/farmacologia , Zearalenona/metabolismo , Zearalenona/administração & dosagem , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Proteína Quinase 7 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 7 Ativada por Mitógeno/química , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 7/metabolismo , MAP Quinase Quinase 7/antagonistas & inibidores , MAP Quinase Quinase 7/química , Relação Estrutura-Atividade , Simulação de Dinâmica Molecular , Cristalografia por Raios X , Estrutura Molecular , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Lactonas , Resorcinóis , MAP Quinase Quinase 4
7.
Bioorg Med Chem Lett ; 100: 129649, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38341162

RESUMO

Peptides are mid-size molecules (700-2000 g/mol) and have attracted particular interest as therapeutic modalities as they are superior in controlling protein-protein interactions, a process that is a typical drug target category, compared with small molecules (<500 g/mol). In 2020, we identified KS-58 (1333 g/mol) as a K-Ras(G12D)-inhibitory bicyclic peptide and suggested its cell membrane permeability. However, the membrane permeability mechanism had not been elucidated. In this study, we aim to clarify the mechanism by molecular dynamics (MD) simulations. Initially, we simulated the molecular conformations of KS-58 in water (a polar solvent) and in chloroform (a non-polar solvent). The identified stable conformations were significantly different in each solvent. KS-58 behaves as a chameleon-like molecule as it alters its polar surface area (PSA) depending on the solvent environment. It was also discovered that orientation of Asp's side chain is a critical energy barrier for KS-58 altering its conformation from hydrophilic to lipophilic. Taking these properties into consideration, we simulated its lipid bilayer membrane permeability. KS-58 shifted toward the inside of the lipid bilayer membrane with altering its conformations to lipophilic. When the simulation condition was set in deionized form of that carboxy group of Asp, KS-58 traveled deeper inside the cell membrane. PSA and the depth of the membrane penetration correlated. In vitro data suggested that cell membrane permeability of KS-58 is improved in weakly acidic conditions leading to partial deionization of the carboxy group. Our data provide an example of the molecular properties of mid-size peptides with membrane accessibility and propose an effective metadynamics approach to elucidate such molecular mechanisms by MD simulations.


Assuntos
Bicamadas Lipídicas , Simulação de Dinâmica Molecular , Peptídeos Cíclicos , Bicamadas Lipídicas/química , Peptídeos/química , Solventes/química , Permeabilidade
8.
Europace ; 26(6)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38788213

RESUMO

AIMS: Human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCM) could be a helpful tool to study the physiology and diseases of the human atrium. To fulfil this expectation, the electrophysiology of hiPSC-aCM should closely resemble the situation in the human atrium. Data on the contribution of the slowly activating delayed rectifier currents (IKs) to repolarization are lacking for both human atrium and hiPSC-aCM. METHODS AND RESULTS: Human atrial tissues were obtained from patients with sinus rhythm (SR) or atrial fibrillation (AF). Currents were measured in human atrial cardiomyocytes (aCM) and compared with hiPSC-aCM and used to model IKs contribution to action potential (AP) shape. Action potential was recorded by sharp microelectrodes. HMR-1556 (1 µM) was used to identify IKs and to estimate IKs contribution to repolarization. Less than 50% of hiPSC-aCM and aCM possessed IKs. Frequency of occurrence, current densities, activation/deactivation kinetics, and voltage dependency of IKs did not differ significantly between hiPSC-aCM and aCM, neither in SR nor AF. ß-Adrenoceptor stimulation with isoprenaline did not increase IKs neither in aCM nor in hiPSC-aCM. In tissue from SR, block of IKs with HMR-1556 did not lengthen the action potential duration, even when repolarization reserve was reduced by block of the ultra-rapid repolarizing current with 4-aminopyridine or the rapidly activating delayed rectifier potassium outward current with E-4031. CONCLUSION: I Ks exists in hiPSC-aCM with biophysics not different from aCM. As in adult human atrium (SR and AF), IKs does not appear to relevantly contribute to repolarization in hiPSC-aCM.


Assuntos
Potenciais de Ação , Fibrilação Atrial , Canais de Potássio de Retificação Tardia , Átrios do Coração , Células-Tronco Pluripotentes Induzidas , Miócitos Cardíacos , Humanos , Miócitos Cardíacos/fisiologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Átrios do Coração/fisiopatologia , Canais de Potássio de Retificação Tardia/metabolismo , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/metabolismo , Feminino , Células Cultivadas , Masculino , Pessoa de Meia-Idade , Cinética , Idoso , Diferenciação Celular , Modelos Cardiovasculares , Bloqueadores dos Canais de Potássio/farmacologia
9.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34725152

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) causes the endothelial tumor KS, a leading cause of morbidity and mortality in sub-Saharan Africa. KSHV-encoded microRNAs (miRNAs) are known to play an important role in viral oncogenesis; however, the role of host miRNAs in KS tumorigenesis remains largely unknown. Here, high-throughput small-RNA sequencing of the cellular transcriptome in a KS xenograft model revealed miR-127-3p as one of the most significantly down-regulated miRNAs, which we validated in KS patient tissues. We show that restoration of miR-127-3p suppresses KSHV-driven cellular transformation and proliferation and induces G1 cell cycle arrest by directly targeting the oncogene SKP2. This miR-127-3p-induced G1 arrest is rescued by disrupting the miR-127-3p target site in SKP2 messenger RNA (mRNA) using gene editing. Mechanistically, miR-127-3p-mediated SKP2 repression elevates cyclin-dependent kinase (CDK) inhibitor p21Cip1 and down-regulates cyclin E, cyclin A, and CDK2, leading to activation of the RB protein tumor suppressor pathway and suppression of the transcriptional activities of E2F and Myc, key oncoprotein transcription factors crucial for KSHV tumorigenesis. Consequently, metabolomics analysis during miR-127-3p-induced cell cycle arrest revealed significant depletion of dNTP pools, consistent with RB-mediated repression of key dNTP biosynthesis enzymes. Furthermore, miR-127-3p reconstitution in a KS xenograft mouse model suppresses KSHV-positive tumor growth by targeting SKP2 in vivo. These findings identify a previously unrecognized tumor suppressor function for miR-127-3p in KS and demonstrate that the miR-127-3p/SKP2 axis is a viable therapeutic strategy for KS.


Assuntos
Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Sarcoma de Kaposi/metabolismo , Animais , Carcinogênese , Feminino , Herpesvirus Humano 8/fisiologia , Humanos , Camundongos Nus , Sarcoma de Kaposi/virologia
10.
Biochem Genet ; 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38374521

RESUMO

Klinefelter syndrome (KS) is the most frequent genetic anomaly in infertile men. Given its unclear mechanism, we aim to investigate critical genes and pathways in the pathogenesis of KS based on three bulk and one single-cell transcriptome data sets from Gene Expression Omnibus. We merged two data sets (GSE42331 and GSE47584) with human KS whole blood samples. When comparing the control and KS samples, five hub genes, including defensin alpha 4 (DEFA4), bactericidal permeability increasing protein (BPI), myeloperoxidase (MPO), intelectin 1 (ITLN1), and Xg Glycoprotein (XG), were identified. Besides, infiltrated degree of certain immune cells such as CD56bright NK cell were positively associated with the expression of ITLN1 and XG. Kyoto Encyclopedia of Genes and Genomes analysis identified upregulated phosphatidylinositol 3-kinase (PI3K)/AKT pathway in KS. Gene set enrichment analysis followed by gene set variation analysis confirmed the upregulation of G2M checkpoint and heme metabolism in KS. Thereafter, the GSE200680 data set was used for external validation of the expression variation of hub genes from healthy to KS testicular samples, and each hub gene yielded excellent discriminatory capability for KS without exception. At the single-cell level, the GSE136353 data set was utilized to evaluate intercellular communication between different cell types in KS patient, and strong correlations were detected between macrophages/ dendritic cells/ NK cells and the other cell types. Collectively, we provided hub genes, pathways, immune cell infiltration degree, and cell-cell communication in KS, warranting novel insights into the pathogenesis of this disease.

11.
BMC Genomics ; 24(1): 757, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38066414

RESUMO

As an economically important tree, Gleditsia sinensis Lam. is widely planted. A lack of background genetic information on G. sinensis hinders molecular breeding. Based on PacBio single-molecule real-time (SMRT) sequencing and analysis of G. sinensis, a total of 95,183 non-redundant transcript sequences were obtained, of which 93,668 contained complete open reading frames (ORFs), 2,858 were long non-coding RNAs (LncRNAs) and 18,855 alternative splicing (AS) events were identified. Genes orthologous to different Gleditsia species pairs were identified, stress-related genes had been positively selected during the evolution. AGA, AGG, and CCA were identified as the universal optimal codon in the genus of Gleditsia. EIF5A was selected as a suitable fluorescent quantitative reference gene. 315 Cytochrome P450 monooxygenases (CYP450s) and 147 uridine diphosphate (UDP)-glycosyltransferases (UGTs) were recognized through the PacBio SMRT transcriptome. Randomized selection of GsIAA14 for cloning verified the reliability of the PacBio SMRT transcriptome assembly sequence. In conclusion, the research data lay the foundation for further analysis of the evolutionary mechanism and molecular breeding of Gleditsia.


Assuntos
Gleditsia , Transcriptoma , Gleditsia/genética , Reprodutibilidade dos Testes , Processamento Alternativo
12.
Emerg Infect Dis ; 29(6): 1268-1269, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37209715

RESUMO

We report a 34-year-old man who had a nonhealing, verrucous plaque with central ulceration on the lower leg. This case-patient is a rare example of endemic limited cutaneous leishmaniasis in Tucson, Arizona, USA. Clinicians should be aware of this disease because its manifestations can vary for individual patients.


Assuntos
Leishmaniose Cutânea , Leishmaniose , Masculino , Humanos , Adulto , Perna (Membro) , Arizona/epidemiologia , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/epidemiologia
13.
Mol Biol Evol ; 39(9)2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35934827

RESUMO

One of the unique features of SARS-CoV-2 is its apparent neutral evolution during the early pandemic (before February 2020). This contrasts with the preceding SARS-CoV epidemics, where viruses evolved adaptively. SARS-CoV-2 may exhibit a unique or adaptive feature which deviates from other coronaviruses. Alternatively, the virus may have been cryptically circulating in humans for a sufficient time to have acquired adaptive changes before the onset of the current pandemic. To test the scenarios above, we analyzed the SARS-CoV-2 sequences from minks (Neovision vision) and parental humans. In the early phase of the mink epidemic (April to May 2020), nonsynonymous to synonymous mutation ratio per site in the spike protein is 2.93, indicating a selection process favoring adaptive amino acid changes. Mutations in the spike protein were concentrated within its receptor-binding domain and receptor-binding motif. An excess of high-frequency derived variants produced by genetic hitchhiking was found during the middle (June to July 2020) and late phase I (August to September 2020) of the mink epidemic. In contrast, the site frequency spectra of early SARS-CoV-2 in humans only show an excess of low-frequency mutations, consistent with the recent outbreak of the virus. Strong positive selection in the mink SARS-CoV-2 implies that the virus may not be preadapted to a wide range of hosts and illustrates how a virus evolves to establish a continuous infection in a new host. Therefore, the lack of positive selection signal during the early pandemic in humans deserves further investigation.


Assuntos
COVID-19 , Evolução Molecular , SARS-CoV-2 , Animais , COVID-19/virologia , Humanos , Vison/virologia , Mutação , Pandemias , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química
14.
Appl Environ Microbiol ; 89(3): e0019623, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36877057

RESUMO

Autotrophic nitrate-reducing Fe(II)-oxidizing (NRFeOx) microorganisms fix CO2 and oxidize Fe(II) coupled to denitrification, influencing carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. However, the distribution of electrons from Fe(II) oxidation to either biomass production (CO2 fixation) or energy generation (nitrate reduction) in autotrophic NRFeOx microorganisms has not been quantified. We therefore cultivated the autotrophic NRFeOx culture KS at different initial Fe/N ratios, followed geochemical parameters, identified minerals, analyzed N isotopes, and applied numerical modeling. We found that at all initial Fe/N ratios, the ratios of Fe(II)oxidized to nitratereduced were slightly higher (5.11 to 5.94 at Fe/N ratios of 10:1 and 10:0.5) or lower (4.27 to 4.59 at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1) than the theoretical ratio for 100% Fe(II) oxidation being coupled to nitrate reduction (5:1). The main N denitrification product was N2O (71.88 to 96.29% at Fe/15N ratios of 10:4 and 5:1; 43.13 to 66.26% at an Fe/15N ratio of 10:1), implying that denitrification during NRFeOx was incomplete in culture KS. Based on the reaction model, on average 12% of electrons from Fe(II) oxidation were used for CO2 fixation while 88% of electrons were used for reduction of NO3- to N2O at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1. With 10 mM Fe(II) (and 4, 2, 1, or 0.5 mM nitrate), most cells were closely associated with and partially encrusted by the Fe(III) (oxyhydr)oxide minerals, whereas at 5 mM Fe(II), most cells were free of cell surface mineral precipitates. The genus Gallionella (>80%) dominated culture KS regardless of the initial Fe/N ratios. Our results showed that Fe/N ratios play a key role in regulating N2O emissions, for distributing electrons between nitrate reduction and CO2 fixation, and for the degree of cell-mineral interactions in the autotrophic NRFeOx culture KS. IMPORTANCE Autotrophic NRFeOx microorganisms that oxidize Fe(II), reduce nitrate, and produce biomass play a key role in carbon, iron, and nitrogen cycles in pH-neutral, anoxic environments. Electrons from Fe(II) oxidation are used for the reduction of both carbon dioxide and nitrate. However, the question is how many electrons go into biomass production versus energy generation during autotrophic growth. Here, we demonstrated that in the autotrophic NRFeOx culture KS cultivated at Fe/N ratios of 10:4, 10:2, 5:2, and 5:1, ca. 12% of electrons went into biomass formation, while 88% of electrons were used for reduction of NO3- to N2O. Isotope analysis also showed that denitrification during NRFeOx was incomplete in culture KS and the main N denitrification product was N2O. Therefore, most electrons stemming from Fe(II) oxidation seemed to be used for N2O formation in culture KS. This is environmentally important for the greenhouse gas budget.


Assuntos
Compostos Férricos , Nitratos , Nitratos/metabolismo , Compostos Férricos/metabolismo , Dióxido de Carbono , Elétrons , Compostos Ferrosos/metabolismo , Oxirredução , Processos Autotróficos , Ferro , Minerais/metabolismo , Desnitrificação
15.
New Phytol ; 237(4): 1405-1417, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36349406

RESUMO

Ferns, and particularly homosporous ferns, have long been assumed to have experienced recurrent whole-genome duplication (WGD) events because of their substantially large genome sizes, surprisingly high chromosome numbers, and high degrees of polyploidy among many extant members. As the number of sequenced fern genomes is limited, recent studies have employed transcriptome data to find evidence for WGDs in ferns. However, they have reached conflicting results concerning the occurrence of ancient polyploidy, for instance, in the lineage of leptosporangiate ferns. Because identifying WGDs in a phylogenetic context is the foremost step in studying the contribution of ancient polyploidy to evolution, we here revisited earlier identified WGDs in leptosporangiate ferns, mainly the core leptosporangiate ferns, by building KS -age distributions and applying substitution rate corrections and by conducting statistical gene tree-species tree reconciliation analyses. Our integrative analyses not only identified four ancient WGDs in the sampled core leptosporangiate ferns but also identified false positives and false negatives for WGDs that recent studies have reported earlier. In conclusion, we underscore the significance of substitution rate corrections and uncertainties in gene tree-species tree reconciliations in calling WGD events and advance an exemplar workflow to overcome such often-overlooked issues.


Assuntos
Gleiquênias , Gleiquênias/genética , Filogenia , Duplicação Gênica , Tamanho do Genoma , Poliploidia , Evolução Molecular , Genoma de Planta
16.
J Med Virol ; 95(3): e28676, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36929740

RESUMO

Reactive oxygen species (ROS) are a group of a highly short-lived molecules that control diverse behaviors of cells. Normal cells maintain ROS balance to ensure their functions. Because of oncogenic stress, cancer cells often have excessive ROS, also known as oxidative stress, which are often counteracted by enhanced antioxidant systems to maintain redox homeostasis. Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus associated with Kaposi's sarcoma (KS), which manifests hyper inflammation and oxidative stress as the hallmarks. We have previously shown that excessive ROS can disrupt KSHV latency by inducing viral lytic replication, leading to cell death. Paradoxically, most KS tumor cells are latently infected by KSHV in a highly inflammatory and oxidative stress tumor microenvironment, which is in part due to the activation of alternative complement and TLR4 pathways, indicating the existence of an enhanced antioxidant defense system in KS tumor cells. In this study, we show that KSHV upregulates antioxidant genes, including SOD2 and CAT by hijacking the forkhead box protein O1 (FoxO1), to maintain intracellular ROS level. Moreover, the fine-tuned balance of ROS level in KSHV-transformed cells is essential for cell survival. Consequently, KSHV-transformed cells are extremely sensitive to exogenous ROS insult such as treatment with a low level of hydrogen peroxide (H2 O2 ). Either chemical inhibition or knockdown of FoxO1 by short interfering RNAs decreases the expression of antioxidant genes and subsequently increases the intracellular ROS level in KSHV-transformed cells, resulting in the inhibition of cell proliferation and colony formation in soft agar. Mechanistically, KSHV-encoded microRNAs and vFLIP upregulate FoxO1 by activating the NF-κB pathway. These results reveal a novel mechanism by which an oncogenic virus counteracts oxidative stress by upregulating FoxO1, which is essential for KSHV-induced cell proliferation and cellular transformation. Therefore, FoxO1 might be a potential therapeutic target for KSHV-related malignancies.


Assuntos
Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/fisiologia , Espécies Reativas de Oxigênio , Antioxidantes/metabolismo , Estresse Oxidativo , Proliferação de Células , Microambiente Tumoral , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo
17.
Curr Top Microbiol Immunol ; 436: 3-49, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36243838

RESUMO

This chapter is an introduction to phosphoinositide 3-kinases (PI3K), with class I PI3Ks as the central focus. First, the various PI3K isoforms in class I are presented with emphasis on their overall structure, subunits, subunit constitutive domains, domain-domain interactions, and functional relevance. This structural analysis is followed by a comprehensive history of seminal investigations into PI3K activity. Next, we highlight the divergent roles of the isoforms: PI3Kα, PI3Kß, PI3Kδ, and PI3Kγ. This section details signaling pathways in which these PI3K isoforms are involved, including the key upstream regulators of PI3K activity and some downstream cellular effects. Nodes of the PI3K pathway are also presented. Inhibitors of some isoforms are discussed to give an overview of the basis of some immunotherapies that are being used to target cell signaling. Finally, the chapter ends with a discussion of the dysregulation of PI3Ks in diseases including APDS, asthma, arthritis, and oncogenic mutations.


Assuntos
Fosfatidilinositol 3-Quinases , Transdução de Sinais , Biologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositóis/farmacologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Transdução de Sinais/fisiologia
18.
Eur J Pediatr ; 182(1): 225-235, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36282322

RESUMO

To present the results of testicular ultrasonography supported by clinical and hormonal aspects in paediatric patients with Klinefelter syndrome (KS). Prospective analysis of medical files of 20 patients diagnosed with KS between 2016 and 2022. Assessed data included analysis of causes of referral, ultrasound, and clinical characterisation with hormonal evaluation of serum FSH, LH, testosterone, inhibin B, and anti-Müllerian hormone. Non-mosaic Klinefelter syndrome (47, XXY) was diagnosed in 65% of cases (13/20) by the geneticist (including 7 cases prenatally), in 25% (5/20) by the endocrinologist and in 10% (2/20) by the hematologist. Ultrasound assessment revealed bilateral testicular microlithiasis (TM) in all patients. The youngest KS patient with TM was 3 months old. TM patterns have not changed during follow-ups of up to 6 years in any of the patients. In all KS patients markedly reduced echogenicity and in pubertal KS patients, also irregular echostructure of the testes was observed. The hormonal patterns observed in the study group were typical for those already described in KS. Sertoli and Leydig cell function was intact in prepubertal patients and deteriorated after the start of puberty. CONCLUSION: Although the degenerative process in the testicular tissue starts very early in the testes in KS and is reflected in morphological changes seen in ultrasonography, Sertoli and Leydig cell hormonal function is normal in prepubertal KS patients. WHAT IS KNOWN: • So far, normal Leydig and Sertoli cell function was observed in infants and prepubertal KS patients. WHAT IS NEW: • The morphological changes in the testes in KS may already be seen in early infancy.


Assuntos
Síndrome de Klinefelter , Doenças Testiculares , Masculino , Humanos , Lactente , Criança , Adolescente , Testículo/diagnóstico por imagem , Testículo/química , Síndrome de Klinefelter/complicações , Síndrome de Klinefelter/diagnóstico , Doenças Testiculares/complicações , Doenças Testiculares/diagnóstico por imagem , Células Intersticiais do Testículo/química , Testosterona/análise
19.
Allergol Immunopathol (Madr) ; 51(4): 110-123, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37422787

RESUMO

BACKGROUND: Treatment of skin allergic diseases remains a challenging research topic. OBJECTIVE: To investigate the effect of Kushen recipe extractive (KS) gel on contact dermatitis (CD) of mouse. METHODS: Allergic contact dermatitis (ACD) model of mouse was established. Immunohistochemical method (ICH) and flow cytometry method (FCM) were used to detect CD4+ and CD8+ T lymphocytes and explore the regulation effect of KS on the immune status of the organism. The expression status of eotaxin tissue was evaluated by real-time polymerase chain reaction (RT-PCR), ICH, and western blotting method. The survival rates of HaCaT cell and Fibroblasts affected by KS were detected by methyl thiazolyl tetrazolium (MTT) method. The inhibitory effect of KS on eotaxin produced by HaCaT cell and FBs induced by TNF-α and interleukin (IL)-4 were evaluated using RT-PCR and enzyme-linked immunosorbent assay methods. The inhibitory effect of KS on nuclear factor-κB (NF-κB) and Signal transducers and activators of transcription 6 (STAT6) activation induced by TNF-α and IL-4 was detected by electrophoretic mobility shift assay and western blotting methods. RESULTS: We confirmed that KS shows favorable therapeutic effect on CD, which can obviously inhibit eotaxin expression and Eosinophils recruitment in allergic skin of mouse, as well as regulate the immune status of the organism. Furthermore, KS and its main effective components can inhibit TNF-α and IL-4 induced upregulation of eotaxin via the two signal transduction pathways, NF-κB and STAT6. CONCLUSIONS: The great importance of traditional Chinese recipe KS is evidenced by its therapeutic effect and mechanism in ACD of mouse.


Assuntos
Dermatite de Contato , Interleucina-4 , Animais , Camundongos , Interleucina-4/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , NF-kappa B/metabolismo , Dermatite de Contato/tratamento farmacológico
20.
Int J Mol Sci ; 24(24)2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38139237

RESUMO

Sugars will eventually be exported transporters (SWEETs) are a novel class of sugar transport proteins that play a crucial role in plant growth, development, and response to stress. However, there is a lack of systematic research on SWEETs in Capsicum annuum L. In this study, 33 CaSWEET genes were identified through bioinformatics analysis. The Ka/Ks analysis indicated that SWEET genes are highly conserved not only among peppers but also among Solanaceae species and have experienced strong purifying selection during evolution. The Cis-elements analysis showed that the light-responsive element, abscisic-acid-responsive element, jasmonic-acid-responsive element, and anaerobic-induction-responsive element are widely distributed in the promoter regions of CaSWEETs. The expression pattern analysis revealed that CaSWEETs exhibit tissue specificity and are widely involved in pepper growth, development, and stress responses. The post-transcription regulation analysis revealed that 20 pepper miRNAs target and regulate 16 CaSWEETs through cleavage and translation inhibition mechanisms. The pathogen inoculation assay showed that CaSWEET16 and CaSWEET22 function as susceptibility genes, as the overexpression of these genes promotes the colonization of pathogens, whereas CaSWEET31 functions as a resistance gene. In conclusion, through systematic identification and characteristic analysis, a comprehensive understanding of CaSWEET was obtained, which lays the foundation for further studies on the biological functions of SWEET genes.


Assuntos
Capsicum , Capsicum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Genes de Plantas , Família Multigênica , Regulação da Expressão Gênica de Plantas , Filogenia
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