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1.
Clin Neuropharmacol ; 47(3): 87-96, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38743602

RESUMO

OBJECTIVES: Clinical manifestations of vitamin B12 deficiency are varied and may result in missed or delayed diagnosis. This investigation explores the diverse clinical manifestations and demographic characteristics of vitamin B12 deficiency in neurology outpatients, aiming to enhance timely diagnosis and outcomes. METHODS: The severity of vitamin B12 deficiency was classified as absolute (≤150 pg/mL) or borderline deficiency (150-300 pg/mL). We conducted a retrospective analysis of 165 outpatients with vitamin B12 deficiency at the department of neurology between May 2020 and May 2021. RESULT: Absolute vitamin B12 deficiency was found in 23.0% of the patients. The most common age range was 50-60 years, the most common cause was vegetarianism, and the most common symptom was headache. Epileptiform symptoms were more likely to occur in younger patients (<20 years old) with vitamin B12 deficiency, whereas psychiatric symptoms were more likely to occur in older patients (>70 years old). Vegetarians, salivation, and nonmegaloblastic anemia were more obvious in patients with absolute vitamin B12 deficiency, whereas headaches often showed borderline B12 deficiency. CONCLUSIONS: The clinical characteristics of vitamin B12 deficiency are complex and nonspecific. The diagnosis should be based on multiple factors.


Assuntos
Pacientes Ambulatoriais , Deficiência de Vitamina B 12 , Humanos , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/epidemiologia , Estudos Retrospectivos , Pessoa de Meia-Idade , Masculino , Feminino , Idoso , Adulto , Adulto Jovem , Adolescente , Cefaleia/diagnóstico , Idoso de 80 Anos ou mais , Neurologia
2.
Nature ; 629(8010): 165-173, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38632398

RESUMO

Streptomyces are a genus of ubiquitous soil bacteria from which the majority of clinically utilized antibiotics derive1. The production of these antibacterial molecules reflects the relentless competition Streptomyces engage in with other bacteria, including other Streptomyces species1,2. Here we show that in addition to small-molecule antibiotics, Streptomyces produce and secrete antibacterial protein complexes that feature a large, degenerate repeat-containing polymorphic toxin protein. A cryo-electron microscopy structure of these particles reveals an extended stalk topped by a ringed crown comprising the toxin repeats scaffolding five lectin-tipped spokes, which led us to name them umbrella particles. Streptomyces coelicolor encodes three umbrella particles with distinct toxin and lectin composition. Notably, supernatant containing these toxins specifically and potently inhibits the growth of select Streptomyces species from among a diverse collection of bacteria screened. For one target, Streptomyces griseus, inhibition relies on a single toxin and that intoxication manifests as rapid cessation of vegetative hyphal growth. Our data show that Streptomyces umbrella particles mediate competition among vegetative mycelia of related species, a function distinct from small-molecule antibiotics, which are produced at the onset of reproductive growth and act broadly3,4. Sequence analyses suggest that this role of umbrella particles extends beyond Streptomyces, as we identified umbrella loci in nearly 1,000 species across Actinobacteria.


Assuntos
Antibiose , Proteínas de Bactérias , Toxinas Bacterianas , Streptomyces , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antibiose/efeitos dos fármacos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Proteínas de Bactérias/ultraestrutura , Toxinas Bacterianas/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/farmacologia , Microscopia Crioeletrônica , Lectinas/química , Lectinas/genética , Lectinas/metabolismo , Lectinas/ultraestrutura , Testes de Sensibilidade Microbiana , Modelos Moleculares , Streptomyces/química , Streptomyces/efeitos dos fármacos , Streptomyces/genética , Streptomyces/crescimento & desenvolvimento , Streptomyces coelicolor/química , Streptomyces coelicolor/genética , Streptomyces coelicolor/metabolismo , Streptomyces griseus/efeitos dos fármacos , Streptomyces griseus/genética , Streptomyces griseus/crescimento & desenvolvimento , Streptomyces griseus/metabolismo
3.
PLoS Pathog ; 20(1): e1011968, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38252661

RESUMO

Macrolides, lincosamides, and streptogramin B (MLS) are structurally distinct molecules that are among the safest antibiotics for prophylactic use and for the treatment of bacterial infections. The family of erythromycin resistance methyltransferases (Erm) invariantly install either one or two methyl groups onto the N6,6-adenosine of 2058 nucleotide (m6A2058) of the bacterial 23S rRNA, leading to bacterial cross-resistance to all MLS antibiotics. Despite extensive structural studies on the mechanism of Erm-mediated MLS resistance, how the m6A epitranscriptomic mark affects ribosome function and bacterial physiology is not well understood. Here, we show that Staphylococcus aureus cells harboring m6A2058 ribosomes are outcompeted by cells carrying unmodified ribosomes during infections and are severely impaired in colonization in the absence of an unmodified counterpart. The competitive advantage of m6A2058 ribosomes is manifested only upon antibiotic challenge. Using ribosome profiling (Ribo-Seq) and a dual-fluorescence reporter to measure ribosome occupancy and translational fidelity, we found that specific genes involved in host interactions, metabolism, and information processing are disproportionally deregulated in mRNA translation. This dysregulation is linked to a substantial reduction in translational capacity and fidelity in m6A2058 ribosomes. These findings point to a general "inefficient translation" mechanism of trade-offs associated with multidrug-resistant ribosomes.


Assuntos
Adenina/análogos & derivados , Antibacterianos , Staphylococcus aureus , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Lincosamidas , Eritromicina/metabolismo , Macrolídeos , Testes de Sensibilidade Microbiana
4.
Autophagy ; 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37974331

RESUMO

Extracellular vesicle DNAs (evDNAs) hold significant diagnostic value for various diseases and facilitate transcellular transfer of genetic material. Our study identifies transcription factor FOXM1 as a mediator for directing chromatin genes or DNA fragments (termed FOXM1-chDNAs) to extracellular vesicles (EVs). FOXM1 binds to MAP1LC3/LC3 in the nucleus, and FOXM1-chDNAs, such as the DUX4 gene and telomere DNA, are designated by FOXM1 binding and translocated to the cytoplasm before being released to EVs through the secretory autophagy during lysosome inhibition (SALI) process involving LC3. Disrupting FOXM1 expression or the SALI process impairs FOXM1-chDNAs incorporation into EVs. FOXM1-chDNAs can be transmitted to recipient cells via EVs and expressed in recipient cells when they carry functional genes. This finding provides an example of how chromatin DNA fragments are specified to EVs by transcription factor FOXM1, revealing its contribution to the formation of evDNAs from nuclear chromatin. It provides a basis for further exploration of the roles of evDNAs in biological processes, such as horizontal gene transfer.

5.
Clin Psychopharmacol Neurosci ; 21(4): 617-633, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37859436

RESUMO

To conduct the association between vitamin B12 and mental health in children and adolescents. Five databases were searched for observational studies in any language reporting on mental health and vitamin B12 levels or intake in children and adolescents from inception to March 18, 2022. Two authors independently extracted data and assessed study quality. Qualitative and quantitative analysis of data were performed. The review was registered in the PROSPERO database (CRD42022345476). Fifty six studies containing 37,932 participants were identified in the review. Vitamin B12 levels were lower in participants with autism spectrum disorders (ASD) (standardized mean difference [SMD], -1.61; 95% confidence interval [95% CI], -2.44 to -0.79; p < 0.001), attention deficit hyperactivity disorders (SMD, -0.39; 95% CI, -0.78 to -0.00; p = 0.049) compared with control group. Vitamin B12 intake were lower in participants with ASDs (SMD, -0.86; 95% CI, -1.48 to -0.24; p = 0.006) compared with control group, but showed no difference between depression group (SMD, -0.06; 95% CI, -0.15 to 0.03; p = 0.17) and the control group. Higher vitamin B12 intake were associated with lower risk of depression (odds ratio [OR], 0.79; 95% CI, 0.63-0.98; p = 0.034) and behavioral problems (OR, 0.83; 95% CI, 0.69-0.99; p = 0.04). The vast majority of included studies supported potential positive influence of vitamin B12 on mental health, and vitamin B12 deficiency may be a reversible cause for some mental health disorders in children and adolescents.

6.
J Clin Neurosci ; 117: 125-135, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37801877

RESUMO

BACKGROUND: To examine serum vitamin B12 concentrations in relation to the risk of ischemic stroke among hospitalized patients in the Department of Neurology. METHODS: We performed a cross-sectional study involving 2,212 inpatients discharged from the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University, from January 2020 to January 2022. The results of laboratory assays such as serum vitamin B12, homocysteine, and folate levels were measured. Logistic regression analysis was used to investigate the association between serum vitamin B12 concentrations and ischemic stroke, with adjustment for a number of relevant demographic and lifestyle factors and comorbidities. RESULTS: A total of 961 (43.4%) patients had an ischemic stroke. In the fully adjusted model, logistic regression analysis suggested a positive association between serum vitamin B12 levels<150 pg/mL (aOR: 1.42; 95% CI 1.02-1.97; p = 0.035), serum vitamin B12 150-300 pg/mL (aOR: 1.37; 95% CI 1.11-1.68; p = 0.003) and the prevalence of ischemic stroke. Furthermore, an inverse association was observed between serum vitamin B12 levels ≥ 900 pg/mL (aOR: 0.38; 95% CI: 0.19-0.77; p =0.007) and the prevalence of ischemic stroke. Moreover, the cut-off value of vitamin B12 concentration was 316.4 pg/mL and the discrimination power of the score evaluated by AUC-ROC was 0.71 (95%CI 0.68-0.73, p<0.001) in the vitamin B12 and ischemic stroke. CONCLUSION: Findings suggest that low vitamin B12 levels may predict the risk of ischemic stroke, early and timely supplementation of vitamin B12 can improve the short-term prognosis of ischemic stroke patients.


Assuntos
AVC Isquêmico , Humanos , Estudos Transversais , Vitamina B 12 , Ácido Fólico , Vitaminas , Homocisteína
7.
Cell Death Dis ; 14(8): 533, 2023 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-37598210

RESUMO

Disrupting protein-protein interactions (PPIs) has emerged as a promising strategy for cancer drug development. Interfering peptides disrupting PPIs can be rationally designed based on the structures of natural sequences mediating these interactions. Transcription factor FOXM1 overexpresses in multiple cancers and is considered an effective target for cancer therapeutic drug development. Using a rational design approach, we have generated a peptide library from the FOXM1 C-terminal sequence and screened FOXM1-binding peptides. Combining FOXM1 binding and cell inhibitory results, we have obtained a FOXM1-targeting interfering peptide M1-20 that is optimized from the natural parent peptide to the D-retro-inverso peptide. With improved stability characteristics, M1-20 inhibits proliferation and migration, and induces apoptosis of cancer cells. Mechanistically, M1-20 inhibits FOXM1 transcriptional activities by disrupting its interaction between the MuvB complex and the transcriptional co-activator CBP. These are consistent with the results that M1-20 suppresses cancer progression and metastasis without noticeable toxic and side effects in wild-type mice. These findings reveal that M1-20 has the potential to be developed as an anti-cancer drug candidate targeting FOXM1.


Assuntos
Neoplasias , Animais , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Peptídeos/farmacologia , Adjuvantes Imunológicos , Apoptose , Sistemas de Liberação de Medicamentos , Fatores de Transcrição
8.
Nutr Hosp ; 40(4): 724-731, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37334792

RESUMO

Introduction: Objectives: to determine the effects of vitamin B12 supplementation on neuropsychological function and disease progression in middle aged and elderly patients with cognitive impairment. Methods: this was a prospective case-control study. From May 2020 to May 2021, 307 participants clinically diagnosed with cognitive impairment in the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University were enrolled. A total of 115 patients were included in this study. Meanwhile, 115 participants with cognitive impairment were randomly assigned in equal proportions to two groups: vitamin B12 treatment group (n = 58, vitamin B12 500 mg/d intramuscularly for seven days, followed by cobamamide 0.25 mg/d and methylcobalamin 0.50 mg/d) and the control group (n = 57). Demographic characteristics and blood biochemical variables were obtained from all participants. Cognitive performance was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Cognitive performance was measured at baseline and after six months. Results: the vitamin B12 supplementation treatment patients who presented with cognitive impairment showed significant improvement, especially in attention, calculation (p < 0.01) and visual-constructional ability (p < 0.05), in their neuropsychological function compared to their matched group. Conclusion: vitamin B12 supplementation may improve frontal function in patients with cognitive decline. Vitamin B12 levels should be investigated in all patients with cognitive impairment.


Introducción: Objetivos: determinar los efectos de la suplementación con vitamina B12 en la función neuropsicológica y la progresión de la enfermedad en pacientes de mediana edad y adultos mayores con deterioro cognitivo. Métodos: se realizó un estudio prospectivo de casos y controles; se estudiaron 307 participantes, desde mayo de 2020 a mayo de 2021, diagnosticados clínicamente con deterioro cognitivo en el Departamento de Neurología, el Primer Hospital Anexado a la Universidad Médica de Chongqing. En el estudio se incluyeron un total de 115 pacientes con deterioro cognitivo que fueron asignados aleatoriamente en proporciones iguales a dos grupos: un grupo de tratamiento con vitamina B12 (n = 58, vitamina B12 500 mg/d intramuscular durante 7 días, seguido de cobamamida 0,25 mg/d y metilcobalamina 0,50 mg/d) y un grupo de control (n = 57). Se obtuvieron las características demográficas y las variables bioquímicas sanguíneas de todos los participantes. El rendimiento cognitivo se midió mediante el miniexamen del estado mental (MMSE) y la evaluación cognitiva de Montreal (Moca) al inicio del estudio y a los 6 meses. Resultados: los pacientes con deterioro cognitivo que recibieron tratamiento de suplementación con vitamina B12 mostraron una mejora significativa, especialmente en la atención, el cálculo (p < 0,01) y la capacidad visuoespacial (p < 0,05), en su función neuropsicológica en comparación con el grupo control. Conclusión: la suplementación con vitamina B12 puede mejorar la función frontal en pacientes con deterioro cognitivo. Los pacientes con deterioro cognitivo deben conocer sus propios niveles de vitamina B12.


Assuntos
Disfunção Cognitiva , Idoso , Humanos , Pessoa de Meia-Idade , Estudos de Casos e Controles , Disfunção Cognitiva/tratamento farmacológico , Vitamina B 12 , Cognição , Vitaminas , Vitamina D , Suplementos Nutricionais
9.
Plant J ; 116(1): 234-250, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37387536

RESUMO

Enhancers are critical cis-regulatory elements controlling gene expression during cell development and differentiation. However, genome-wide enhancer characterization has been challenging due to the lack of a well-defined relationship between enhancers and genes. Function-based methods are the gold standard for determining the biological function of cis-regulatory elements; however, these methods have not been widely applied to plants. Here, we applied a massively parallel reporter assay on Arabidopsis to measure enhancer activities across the genome. We identified 4327 enhancers with various combinations of epigenetic modifications distinctively different from animal enhancers. Furthermore, we showed that enhancers differ from promoters in their preference for transcription factors. Although some enhancers are not conserved and overlap with transposable elements forming clusters, enhancers are generally conserved across thousand Arabidopsis accessions, suggesting they are selected under evolution pressure and could play critical roles in the regulation of important genes. Moreover, comparison analysis reveals that enhancers identified by different strategies do not overlap, suggesting these methods are complementary in nature. In sum, we systematically investigated the features of enhancers identified by functional assay in A. thaliana, which lays the foundation for further investigation into enhancers' functional mechanisms in plants.


Assuntos
Arabidopsis , Animais , Arabidopsis/genética , Elementos Facilitadores Genéticos/genética , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Epigênese Genética
10.
Cell Biosci ; 13(1): 114, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37344857

RESUMO

BACKGROUND: Transcription factor FOXM1 is a potential target for anti-cancer drug development. An interfering peptide M1-21, targeting FOXM1 and FOXM1-interacting proteins, is developed and its anti-cancer efficacy is evaluated. METHODS: FOXM1 C-terminus-binding peptides are screened by in silico protocols from the peptide library of FOXM1 (1-138aa) and confirmed by cellular experiments. The selected peptide is synthesized into its D-retro-inverso (DRI) form by fusing a TAT cell-penetrating sequence. Anti-cancer activities are evaluated in vitro and in vivo with tumor-grafted nude mice, spontaneous breast cancer mice, and wild-type metastasis-tracing mice. Anti-cancer mechanisms are analyzed. Distribution and safety profiles in mice are evaluated. RESULTS: With improved stability and cell inhibitory activity compared to the parent peptide, M1-21 binds to multiple regions of FOXM1 and interferes with protein-protein interactions between FOXM1 and its various known partner proteins, including PLK1, LIN9 and B-MYB of the MuvB complex, and ß-catenin. Consequently, M1-21 inhibits FOXM1-related transcriptional activities and FOXM1-mediated nuclear importation of ß-catenin and ß-catenin transcriptional activities. M1-21 inhibits multiple types of cancer (20 µM in vitro or 30 mg/kg in vivo) by preventing proliferation, migration, and WNT signaling. Distribution and safety profiles of M1-21 are favorable (broad distribution and > 15 h stability in mice) and the tested non-severely toxic dose reaches 200 mg/kg in mice. M1-21 also has low hemolytic toxicity and immunogenicity in mice. CONCLUSIONS: M1-21 is a promising interfering peptide targeting FOXM1 for the development of anti-cancer drugs.

11.
Clin Biochem ; 118: 110591, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37247800

RESUMO

Ischemic stroke is the most prevalent form of stroke and has a high incidence in older adults, characterized by high morbidity, mortality, disability, and recurrence rate. Vitamin B12 deficiency is prevalent in the elderly and has been reported to be associated with ischemic stroke. The mechanisms maybe include the disorder of methylation metabolism, accumulation of toxic metabolites, immune dysfunction, affecting gut microbial composition and gut-brain immune homeostasis, and toxic stress responses to the brain. Vitamin B12 deficiency may lead to cerebral artery atherosclerosis, change myelination, influence the metabolism and transmission between nerve tissue, and ultimately causes the occurrence and development of ischemic stroke. This paper reviews the correlation between vitamin B12 deficiency and ischemic stroke, looking forward to improving clinicians' understanding and providing new therapeutic directions for ischemic stroke.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Deficiência de Vitamina B 12 , Humanos , Idoso , Vitamina B 12 , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/tratamento farmacológico , Acidente Vascular Cerebral/epidemiologia , Vitaminas
12.
Neuropsychiatr Dis Treat ; 19: 785-800, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37056916

RESUMO

Purpose: To evaluate the prevalence of abnormal vitamin B12, folate, total homocysteine (tHcy), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP) levels, to analyze the relationship between these parameters and the severity of anxiety or depressive symptoms, and to explore the possible factors associated with abnormal levels of these parameters in adolescents with anxiety or depressive symptoms. Methods: Adolescent (aged 12-18 years) outpatients with anxiety or depressive symptoms were recruited. The patient health questionnaire-9 and generalized anxiety disorder scale-7 were used to measure the severity of depression and anxiety. Serum vitamin B12, folate, tHcy, IL-6, TNF-α, and CRP levels were determined. Results: 128 subjects were recruited. The prevalence of vitamin B12 and folate deficiency, tHcy, TNF-α, IL-6, and CRP elevation was 8.6%, 10.2%, 25.8%, 14.8%, 21.9%, and 10.2%, respectively, in adolescents with anxiety or depressive symptoms. Lower vitamin B12 levels were correlated with a higher risk of severe anxiety and depressive symptoms. The severity of some symptoms of anxiety or depression were weakly correlated with vitamin B12, folate, tHcy, IL-6, and CRP levels. Vitamin B12, folate, and tHcy levels were not associated with inflammatory mediators. Vitamin B12 deficiency was associated with older age and higher tHcy levels. Folate deficiency was associated with elevated tHcy. Elevated tHcy was associated with lower vitamin B12 and folate levels. IL-6 elevation was associated with elevated CRP and TNF-α. CRP elevation was associated with older age, higher BMI, and current drinking. Conclusion: Lower vitamin B12 levels were correlated with a higher risk of severe anxiety or depressive symptoms. Weak correlations were observed between the severity of some symptoms of anxiety or depression and vitamin B12, folate, tHcy, IL-6, and CRP levels. Vitamin B12, folate, and tHcy levels were related to each other. IL-6 elevation was associated with elevated CRP and TNF-α. CRP elevation was associated with older age, higher BMI, and current drinking.

13.
Cell Rep ; 42(3): 112151, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36827186

RESUMO

Transposable elements (TEs) are abundant in metazoan genomes and have multifaceted effects on host fitness. However, the mechanisms underlying the functions of TEs are still not fully understood. Here, we combine Hi-C, ATAC-seq, and ChIP-seq assays to report the existence of multimegabase supersized loop (SSL) clusters in the Xenopus tropicalis sperm. We show that SSL anchors are inaccessible and devoid of the architectural protein CTCF, RNA polymerase II, and modified histones. Nearly all SSL anchors are marked by Helitrons, a class II DNA transposon. Molecular dynamics simulations indicate that SSL clusters are likely formed via a molecular agent-mediated chromatin condensation process. However, only slightly more SSL anchor-associated genes are expressed at late embryo development stages, suggesting that SSL anchors might only function in sperm. Our work shows an evolutionarily distinct and sperm-specific genome structure marked by a subset of Helitrons, whose establishment and function remain to be explored.


Assuntos
Elementos de DNA Transponíveis , Sêmen , Animais , Masculino , Xenopus/genética , Elementos de DNA Transponíveis/genética , Histonas/genética , Cromatina/genética
14.
Protein Sci ; 32(1): e4531, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36477982

RESUMO

Detection of homologous relationships among proteins and understanding their mechanisms of diversification are major topics in the fields of protein science, bioinformatics, and phylogenetics. Recent developments in sequence/profile-based and structural similarity-based methods have greatly facilitated the unification and classification of many protein families into superfamilies or folds, yet many proteins remain unclassified in current protein databases. As one of the three earliest identified RNases in biology, ribonuclease T2, also known as RNase I in Escherichia coli, RNase Rh in fungi, or S-RNase in plant, is thought to be an ancient RNase family due to its widespread distribution and distinct structure. In this study, we present evidence that RNase T2 represents a circularly permutated version of the BECR (Barnase-EndoU-Colicin E5/D-RelE) fold RNases. This subtle relationship cannot be detected by traditional methods such as sequence/profile-based comparisons, structure-similarity searches, and circular permutation detections. However, we were able to identify the structural similarity using rational reconstruction of a theoretical RNase T2 ancestor via a reverse circular permutation process, followed by structural modeling using AlphaFold2, and structural comparisons. This relationship is further supported by the fact that RNase T2 and other typical BECR RNases, namely Colicin D, RNase A, and BrnT, share similar catalytic site configurations, all involving an analogous set of conserved residues on the α0 helix and the ß4 strand of the BECR fold. This study revealed a hidden root of RNase T2 in bacterial toxin systems and demonstrated that reconstruction and modeling of ancestral topology is an effective strategy to identify remote relationship between proteins.


Assuntos
Colicinas , Ribonuclease Pancreático , Ribonuclease Pancreático/química , Sequência de Aminoácidos , Ribonucleases/química , Escherichia coli/genética , Escherichia coli/metabolismo
15.
Front Neurol ; 13: 1000777, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36468067

RESUMO

Ischemic stroke is a common cerebrovascular disease that seriously affects human health. However, most patients do not practice self-care and cannot rely on the current clinical treatment for guaranteed functional recovery. Stem cell transplantation is an emerging treatment studied in various central nervous system diseases. More importantly, animal studies show that transplantation of mesenchymal stem cells (MSCs) can alleviate neurological deficits and bring hope to patients suffering from ischemic stroke. This paper reviews the biological characteristics of MSCs and discusses the mechanism and progression of MSC transplantation to provide new therapeutic directions for ischemic stroke.

16.
Comput Struct Biotechnol J ; 20: 4517-4531, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36051883

RESUMO

Bacteria have developed several molecular conflict systems to facilitate kin recognition and non-kin competition to gain advantages in the acquisition of growth niches and of limited resources. One such example is a large class of so-called polymorphic toxin systems (PTSs), which comprise a variety of the toxin proteins secreted via T2SS, T5SS, T6SS, T7SS and many others. These systems are highly divergent in terms of sequence/structure, domain architecture, toxin-immunity association, and organization of the toxin loci, which makes it difficult to identify and characterize novel systems using traditional experimental and bioinformatic strategies. In recent years, we have been developing and utilizing unique genome-mining strategies and pipelines, based on the organizational principles of both domain architectures and genomic loci of PTSs, for an effective and comprehensive discovery of novel PTSs, dissection of their components, and prediction of their structures and functions. In this study, we present our systematic discovery of a new type of PTS (S8-PTS) in several gram-positive bacteria. We show that the S8-PTS contains three components: a peptidase of the S8 family (subtilases), a polymorphic toxin, and an immunity protein. We delineated the typical organization of these polymorphic toxins, in which a N-terminal signal peptide is followed by a potential receptor binding domain, BetaH, and one of 16 toxin domains. We classified each toxin domain by the distinct superfamily to which it belongs, identifying nine BECR ribonucleases, one Restriction Endonuclease, one HNH nuclease, two novel toxin domains homologous to the VOC enzymes, one toxin domain with the Frataxin-like fold, and several other unique toxin families such as Ntox33 and HicA. Accordingly, we identified 20 immunity families and classified them into different classes of folds. Further, we show that the S8-PTS-associated peptidases are analogous to many other processing peptidases found in T5SS, T7SS, T9SS, and many proprotein-processing peptidases, indicating that they function to release the toxin domains during secretion. The S8-PTSs are mostly found in animal and plant-associated bacteria, including many pathogens. We propose S8-PTSs will facilitate the competition of these bacteria with other microbes or contribute to the pathogen-host interactions.

17.
Am J Cancer Res ; 12(6): 2641-2658, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35812039

RESUMO

The transcription factor FOXA1, which is a member of the forkhead class of DNA-binding proteins, interacts with Estrogen Receptor (ER) to mediate breast cancer progression. However, its role in basal breast cancer cells remains unclear. Although the overall levels of FOXA1 are decreased in the basal subtype of clinical TCGA breast cancer samples, the high levels of FOXA1 improve the survival of the patients from this subtype. This clinical phenomenon is consistent with that of FOXA1 stimulating apoptosis in FOXA1-low expressing basal breast cancer cells, such as MDA-MB-231, and MDA-MB-468 cells. In this study, we have constructed an inducible expression system of FOXA1 and demonstrated the induced expression of FOXA1 resulting in apoptosis and cell cycle arrest in MDA-MB-231 cells, as confirmed by transcriptomic analysis and in vivo tumor-grafted models. Furthermore, the low levels of Estrogen Receptor-1 (ESR1) are critical for FOXA1 in terms of its repressive roles in the cells, as evidenced by clinical data analysis indicating that the high levels of FOXA1 improve the survival of ESR1Low patients, but worsen the survival of ESR1High patients of breast cancer. When introduced into MDA-MB-231 cells, ESR1 counteracts the tumor suppressor roles of FOXA1 by altering the FOXA1-regulated gene transcription and the two proteins together maintain the tumor progression in vivo. Our cumulative results suggest that FOXA1 suppresses the basal breast cancer cells with FOXA1-low expressing status independent of ESR1 by inducing apoptosis and inhibiting cell proliferation, thereby implicating its potential therapeutic role in this group of breast cancer.

18.
Stem Cell Res Ther ; 13(1): 195, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35551643

RESUMO

Ischemic stroke is one of the major causes of death and disability in the world. Currently, most patients cannot choose intravenous thrombolysis or intravascular mechanical thrombectomy because of narrow therapeutic windows and severe complications. Stem cell transplantation is an emerging treatment and has been studied in various central nervous system diseases. Animal and clinical studies showed that transplantation of mesenchymal stem cells (MSCs) could alleviate neurological deficits and bring hope for ischemic stroke treatment. This article reviewed biological characteristics, safety, feasibility and efficacy of MSCs therapy, potential therapeutic targets of MSCs, and production process of Good Manufacturing Practices-grade MSCs, to explore the potential therapeutic targets of MSCs in the process of production and use and provide new therapeutic directions for ischemic stroke.


Assuntos
AVC Isquêmico , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Acidente Vascular Cerebral , Animais , Humanos , AVC Isquêmico/terapia , Células-Tronco Mesenquimais/metabolismo , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/terapia
19.
Comput Struct Biotechnol J ; 20: 261-273, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35024098

RESUMO

Globins constitute an ancient superfamily of proteins, exhibiting enormous structural and functional diversity, as demonstrated by many heme-binding families and two non-heme binding families that were discovered in bacterial stressosome component RsbR and in light-harvesting phycobiliproteins (phycocyanin) in cyanobacteria and red algae. By comprehensively exploring the globin repertoire using sensitive computational analyses of sequences, structures, and genomes, we present the identification of the third family of non-heme binding globins-the photoglobin. By conducting profile-based comparisons, clustering analyses, and structural modeling, we demonstrate that photoglobin is related to, but distinct from, the phycocyanin family. Photoglobin preserves a potential ligand-binding pocket, whose residue configuration closely resembles that of phycocyanin, indicating that photoglobin potentially binds to a comparable linear tetrapyrrole. By exploring the contextual information provided by the photoglobin's domain architectures and gene-neighborhoods, we found that photoglobin is frequently associated with the B12-binding light sensor domain and many domains typical of prokaryotic signal transduction systems. Structural modeling using AlphaFold2 demonstrated that photoglobin and B12-binding domains form a structurally conserved hub among different domain architecture contexts. Based on these strong associations, we predict that the coupled photoglobin and B12-binding domains act as a light-sensing regulatory bundle, with each domain sensing different wavelengths of light resulting in switch-like regulation of downstream signaling effectors. Thus, based on the above lines of evidence, we present a distinct non-heme binding globin family and propose that it may define a new type of light sensor, by means of a linear tetrapyrrole, in complex prokaryotic signal transduction systems.

20.
J Hazard Mater ; 424(Pt D): 127703, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34799159

RESUMO

Rice (Oryza sativa L.), a staple for half of the world's population, usually accumulates high levels of cadmium (Cd) in the grain when planted in the Cd-contaminated paddy fields. Genetic improvements using natural variation of grain-Cd accumulation is the most cost-effective way to mitigate the risk of excess Cd accumulation. However, as a complex trait, grain-Cd accumulation is susceptible to environmental variation, which challenges to characterize the genetic nature and subsequently the stable performance of grain-Cd accumulation. To boost the genetic effect on grain-Cd performance, we established an approach of normalization using the comparative grain-Cd value (CCd) following a contrasting field design. Identification of the genetic locus responsible for CCd variation help us develop a low-grain-Cd variety de novo, named 'Lushansimiao', which had lower grain-Cd levels in a large-scale field test and can produce Cd-safe rice following prolonged irrigations in the field with intermediate levels of Cd pollution. Combined CCd evaluating and low-Cd allelic genotyping, another six varieties were also identified as low-grain-Cd rice. Our study paves the way to efficiently quantify the genetic nature of grain-Cd accumulation in rice, and the stable low-Cd rice varieties will help to mitigate the risk of excess Cd accumulation in rice.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Grão Comestível/química , Genótipo , Oryza/genética , Solo , Poluentes do Solo/análise
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