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1.
mSphere ; : e0036324, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39189774

RESUMO

ClpXP is a protease complex that plays important roles in protein quality control and cell cycle regulation, but the functions of multiple ClpXs and multiple ClpPs in M. xanthus remain unknown. The genome of Myxococcus xanthus DK1622 contains two clpPs and three clpXs. The clpP1 and clpX1 genes are cotranscribed and are both essential, while the other copies are isolated in the genome and are deletable. The deletion of clpX2 caused the mutant to be deficient in fruiting body development, while the clpX3 gene is involved in resistance to thermal stress. Both ClpPs possess catalytic active sites, but only ClpP1 shows in vitro peptidase activity on the typical substrate Suc-LY-AMC. All of these clpP and clpX genes exhibit strong transcriptional upregulation in the stationary phase, and the transcription of the three clpX genes appears to be coordinated. Our results demonstrated that multiple ClpPs and multiple ClpXs are functionally divergent and may assist in the environmental adaptation and functional diversification of M. xanthus.IMPORTANCEClpXP is an important protease complex of bacteria and is involved in various physiological processes. Myxococcus xanthus DK1622 possesses two ClpPs and three ClpXs with unclear functions. We investigated the functions of these genes and demonstrated the essential roles of clpP1 and clpX1. Only ClpP1 has in vitro peptidase activity on Suc-LY-AMC, and the isolated clpX copies participate in distinct cellular processes. All of these genes exhibited significant transcriptional upregulation in the stationary phase. Divergent functions appear in multiple ClpPs and multiple ClpXs in M. xanthus DK1622.

2.
Phys Rev E ; 109(6-2): 065205, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39020960

RESUMO

Collision between relativistic electron sheets and counterpropagating laser pulses is recognized as a promising way to produce intense attosecond x rays through coherent Thomson backscattering (TBS). In a double-layer scheme, the electrons in an ultrathin solid foil are first pushed out by an intense laser driver and then interact with the laser reflected off a second foil to form a high-density relativistic electron sheet with vanishing transverse momentum. However, the repulsion between these concentrated electrons can increase the thickness of the layer, reducing both its density and subsequently the coherent TBS. Here, we present a systematic study on the evolution of the flying electron layer and find that its resulting thickness is determined by the interplay between the intrinsic space-charge expansion and the velocity compression induced by the drive laser. How the laser driver, the target areal density, the reflector, and the collision laser intensity affect the properties of the produced x rays is explored. Multidimensional particle-in-cell simulations indicate that employing this scheme in the nonlinear regime has the potential to stably produce soft x rays with several gigawatt peak power in hundreds of terawatt ultrafast laser facilities. The pulse duration can be tuned to tens of attoseconds. This compact and intense attosecond x-ray source may have broad applications in attosecond science.

3.
Clin Kidney J ; 17(7): sfae196, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39050866

RESUMO

Background: Diabetic kidney disease (DKD) poses a significant challenge globally as a complication of diabetes. Hyaluronan (HA), a critical non-sulfated glycosaminoglycan in the extracellular matrix, plays a pivotal role in the progression of DKD. This study assesses the predictive significance of HA's corresponding receptor, RHAMM (receptor for HA-mediated motility), in DKD pathogenesis in type 2 diabetes (T2DM) patients. Methods: Enzyme-linked immunosorbent assays were utilized to measure plasma and urine levels of HA, CD44 and RHAMM in 99 diabetic patients. Immunohistochemistry staining was employed to examine HA deposition, CD44 and RHAMM expressions from 18 biopsy-proven DKD patients. Spearman correlation analysis, linear regression and receiver operating characteristic (ROC) analysis were conducted to establish associations between plasma HA, CD44 and RHAMM levels, and clinical parameters in DKD patients with T2DM. Results: Elevated plasma and urine HA, CD44 and RHAMM levels were notably observed in the severe renal dysfunction group. Plasma RHAMM exhibited positive correlations with HA (r = 0.616, P < .001) and CD44 (r = 0.220, P < .001), and a negative correlation with estimated glomerular filtration rate (eGFR) (r = -0.618, P < .001). After adjusting for other potential predictors, plasma RHAMM emerged as an independent predictor of declining eGFR (ß = -0.160, P < .05). Increased HA, CD44 and RHAMM levels in kidney biopsies of DKD patients were closely associated with heightened kidney injury. The ROC curve analysis highlighted an area under the curve (AUC) of 0.876 for plasma RHAMM, indicating superior diagnostic efficacy compared to CD44 in predicting DKD pathogenesis. The combined AUC of 0.968 for plasma RHAMM, HA and CD44 also suggested even greater diagnostic potential for DKD pathogenesis. Conclusion: These findings provide initial evidence that elevated RHAMM levels predict DKD pathogenesis in T2DM patients. The formation of a triple complex involving HA, CD44 and RHAMM on the cell surface shows promise as a targetable biomarker for early intervention to mitigate severe renal dysfunctions.

4.
Front Endocrinol (Lausanne) ; 15: 1370114, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694938

RESUMO

Objective: Despite the developments of in vitro fertilization (IVF) protocols, implantation failure remains a challenging problem, owing to the unbalance between the embryo, endometrium, and immune system interactions. Effective treatments are urgently required to improve successful implantation. Recently, many researchers have focused on granulocyte colony-stimulating factor (G-CSF) to regulate immune response and embryo-endometrium cross-talk. However, previous studies have reported inconsistent findings on the efficacy of G-CSF therapy on implantation failure. The objective of this review was to further explore the effects of G-CSF according to administration dosage and timing among women who experienced at least one implantation failure. Methods: We systematically searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Scopus, and Web of Science for randomized controlled trials of G-CSF on implantation failure up to July 21, 2023. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated and the heterogeneity of the studies with the I2 index was analyzed. Results: We identified a total of 2031 studies and finally included 10 studies in the systematic review and meta-analysis. G-CSF administration improved the clinical pregnancy rate (CPR), implantation rate (IR), biochemical pregnancy rate (BPR), and live birth rate (LBR) in women with at least one implantation failure. Subgroup analyses showed that G-CSF treatment could exert good advantages in improving CPR [OR=2.49, 95%CI (1.56, 3.98), I2 = 0%], IR [OR=2.82, 95%CI (1.29, 6.15)], BPR [OR=3.30, 95%CI (1.42, 7.67)] and LBR [OR=3.16, 95%CI (1.61, 6.22), I2 = 0%] compared with the blank control group. However, compared with placebo controls, G-CSF showed beneficial effects on CPR [OR=1.71, 95%CI (1.04, 2.84), I2 = 38%] and IR [OR=2.01, 95%CI (1.29, 3.15), I2 = 24%], but not on LBR. In addition, >150µg of G-CSF treatment increased CPR [OR=2.22, 95%CI (1.47, 3.35), I2 = 0%], IR [OR=2.67, 95%CI (1.47, 4.82), I2 = 0%] and BPR [OR=2.02, 95%CI (1.17, 3.47), I2 = 22%], while ≤150µg of G-CSF treatment improved miscarriage rate (MR) [OR=0.14, 95%CI (0.05, 0.38), I2 = 0%] and LBR [OR=2.65, 95%CI (1.56, 4.51), I2 = 0%]. Moreover, G-CSF administration on the day of embryo transfer (ET) could increase CPR [OR=2.81, 95%CI (1.37, 5.75), I2 = 0%], but not on the day of ovum pick-up (OPU) or human chorionic gonadotropin (HCG) injection. Conclusion: G-CSF has a beneficial effect on pregnancy outcomes to some extent among women who experienced at least one implantation failure, and the administration dosage and timing influence the effect size.Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023447046.


Assuntos
Implantação do Embrião , Fertilização in vitro , Fator Estimulador de Colônias de Granulócitos , Taxa de Gravidez , Humanos , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Implantação do Embrião/efeitos dos fármacos , Gravidez , Fertilização in vitro/métodos , Transferência Embrionária/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Falha de Tratamento
5.
ACS Cent Sci ; 10(3): 555-568, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38559311

RESUMO

Myxobacteria are a prolific source of secondary metabolites with sheer chemical complexity, intriguing biosynthetic enzymology, and diverse biological activities. In this study, we report the discovery, biosynthesis, biomimetic total synthesis, physiological function, structure-activity relationship, and self-resistance mechanism of the 5-methylated pyrazinone coralinone from a myxobacterium Corallococcus exiguus SDU70. A single NRPS/PKS gene corA was genetically and biochemically demonstrated to orchestrate coralinone, wherein the integral PKS part is responsible for installing the 5-methyl group. Intriguingly, coralinone exacerbated cellular aggregation of myxobacteria grown in liquid cultures by enhancing the secretion of extracellular matrix, and the 5-methylation is indispensable for the alleged activity. We provided an evolutionary landscape of the corA-associated biosynthetic gene clusters (BGCs) distributed in the myxobacterial realm, revealing the divergent evolution for the diversity-oriented biosynthesis of 5-alkyated pyrazinones. This phylogenetic contextualization provoked us to identify corB located in the proximity of corA as a self-resistance gene. CorB was experimentally verified to be a protease that hydrolyzes extracellular proteins to antagonize the agglutination-inducing effect of coralinone. Overall, we anticipate these findings will provide new insights into the chemical ecology of myxobacteria and lay foundations for the maximal excavation of these largely underexplored resources.

6.
Synth Syst Biotechnol ; 9(3): 540-548, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38680947

RESUMO

The chromosomal position effect can significantly affect the transgene expression, which may provide an efficient strategy for the inauguration of alien genes in new hosts, but has been less explored rationally. The bacterium Myxococcus xanthus harbors a large circular high-GC genome, and the position effect in this chassis may result in a thousand-fold expression variation of alien natural products. In this study, we conducted transposon insertion at TA sites on the M. xanthus genome, and used enrichment and dilution indexes to respectively appraise high and low expression potentials of alien genes at insertion sites. The enrichment sites are characteristically distributed along the genome, and the dilution sites are overlapped well with the horizontal transfer genes. We experimentally demonstrated the enrichment sites as high expression integration sites (HEISs), and the dilution sites unsuitable for gene integration expression. This work highlights that HEISs are the plug-and-play sites for efficient expression of integrated genes.

7.
J Proteomics ; 298: 105144, 2024 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-38431085

RESUMO

Effective therapies of chronic kidney disease (CKD) are lacking due to the unclear molecular pathogenesis. Previous single omics-studies have described potential molecular regulation mechanism of CKD only at the level of transcription or translation. Therefore, this study generated an integrated transcriptomic and proteomic profile to provide deep insights into the continuous transcription-translation process during CKD. The comprehensive datasets identified 14,948 transcripts and 6423 proteins, 233 up-regulated and 364 down-regulated common differentially expressed genes of transcriptome and proteome were selected to further combined bioinformatics analysis. The obtained results revealed reactive oxygen species (ROS) metabolism and antioxidant system due to imbalance of mitochondria and peroxisomes were significantly repressed in CKD. Overall, this study presents a valuable multi-omics analysis that sheds light on the molecular mechanisms underlying CKD. SIGNIFICANCE: Chronic kidney disease (CKD) is a progressive and irreversible condition that results in abnormal kidney function and structure, and is ranked 18th among the leading causes of death globally, leading to a significant societal burden. Hence, there is an urgent need for research to detect new, sensitive, and specific biomarkers. Omics-based studies offer great potential to identify underlying disease mechanisms, aid in clinical diagnosis, and develop novel treatment strategies for CKD. Previous studies have mainly focused on the regulation of gene expression or protein synthesis in CKD, thereby compelling us to conduct a meticulous analysis of transcriptomic and proteomic data from the UUO mouse model. Here, we have performed a unified analysis of CKD model by integrating transcriptomes and protein suites for the first time. Our study contributes to a deeper understanding of the pathogenesis of CKD and provides a basis for subsequent disease management and drug development.


Assuntos
Insuficiência Renal Crônica , Obstrução Ureteral , Camundongos , Animais , Transcriptoma , Fosforilação Oxidativa , Proteômica , Peroxissomos/metabolismo , Peroxissomos/patologia , Perfilação da Expressão Gênica/métodos , Insuficiência Renal Crônica/metabolismo , Fibrose , Obstrução Ureteral/genética , Obstrução Ureteral/metabolismo , Obstrução Ureteral/patologia , Rim/metabolismo
8.
mSystems ; 9(4): e0115423, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38530057

RESUMO

The chaperone 70 kDa heat shock protein (Hsp70) is important for cells from bacteria to humans to maintain proteostasis, and all eukaryotes and several prokaryotes encode Hsp70 paralogs. Although the mechanisms of Hsp70 function have been clearly illuminated, the function and evolution of Hsp70 paralogs is not well studied. DnaK is a highly conserved bacterial Hsp70 family. Here, we show that dnaK is present in 98.9% of bacterial genomes, and 6.4% of them possess two or more DnaK paralogs. We found that the duplication of dnaK is positively correlated with an increase in proteomic complexity (proteome size, number of domains). We identified the interactomes of the two DnaK paralogs of Myxococcus xanthus DK1622 (MxDnaKs), which revealed that they are mostly nonoverlapping, although both prefer α and ß domain proteins. Consistent with the entire M. xanthus proteome, MxDnaK substrates have both significantly more multi-domain proteins and a higher isoelectric point than that of Escherichia coli, which encodes a single DnaK homolog. MxDnaK1 is transcriptionally upregulated in response to heat shock and prefers to bind cytosolic proteins, while MxDnaK2 is downregulated by heat shock and is more associated with membrane proteins. Using domain swapping, we show that the nucleotide-binding domain and the substrate-binding ß domain are responsible for the significant differences in DnaK interactomes, and the nucleotide binding domain also determines the dimerization of MxDnaK2, but not MxDnaK1. Our work suggests that bacterial DnaK has been duplicated in order to deal with a more complex proteome, and that this allows evolution of distinct domains to deal with different subsets of target proteins.IMPORTANCEAll eukaryotic and ~40% of prokaryotic species encode multiple 70 kDa heat shock protein (Hsp70) homologs with similar but diversified functions. Here, we show that duplication of canonical Hsp70 (DnaK in prokaryotes) correlates with increasing proteomic complexity and evolution of particular regions of the protein. Using the Myxococcus xanthus DnaK duplicates as a case, we found that their substrate spectrums are mostly nonoverlapping, and are both consistent to that of Escherichia coli DnaK in structural and molecular characteristics, but show differential enrichment of membrane proteins. Domain/region swapping demonstrated that the nucleotide-binding domain and the ß substrate-binding domain (SBDß), but not the SBDα or disordered C-terminal tail region, are responsible for this functional divergence. This work provides the first direct evidence for regional evolution of DnaK paralogs.


Assuntos
Proteínas de Escherichia coli , Proteoma , Humanos , Proteoma/genética , Proteínas de Escherichia coli/genética , Proteômica , Proteínas de Choque Térmico HSP70/genética , Escherichia coli/genética , Bactérias/metabolismo , Proteínas de Membrana/metabolismo , Nucleotídeos/metabolismo
9.
Nucleic Acids Res ; 52(D1): D724-D731, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-37823598

RESUMO

Microorganisms encode most of the functions of life on Earth. However, conventional research has primarily focused on specific environments such as humans, soil and oceans, leaving the distribution of functional families throughout the global biosphere poorly comprehended. Here, we present the database of the global distribution of prokaryotic protein families (GDPF, http://bioinfo.qd.sdu.edu.cn/GDPF/), a data resource on the distribution of functional families across the global biosphere. GDPF provides global distribution information for 36 334 protein families, 19 734 superfamilies and 12 089 KEGG (Kyoto Encyclopedia of Genes and Genomes) orthologs from multiple source databases, covering typical environments such as soil, oceans, animals, plants and sediments. Users can browse, search and download the distribution data of each entry in 10 000 global microbial communities, as well as conduct comparative analysis of distribution disparities among multiple entries across various environments. The GDPF data resource contributes to uncovering the geographical distribution patterns, key influencing factors and macroecological principles of microbial functions at a global level, thereby promoting research in Earth ecology and human health.


Assuntos
Ecologia , Células Procarióticas , Proteínas , Animais , Humanos , Solo , Família Multigênica , Proteínas/genética
10.
mSystems ; 8(3): e0128922, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37195192

RESUMO

Different habitats harbor different microbial communities with elusive assembly mechanisms. This study comprehensively investigated the global assembly mechanisms of microbial communities and effects of community-internal influencing factors using the Earth Microbiome Project (EMP) data set. We found that deterministic and stochastic processes contribute approximately equally to global microbial community assembly, and, specifically, deterministic processes generally play a major role in free-living and plant-associated (but not plant corpus) environments, while stochastic processes are the major contributor in animal-associated environments. In contrast with the assembly of microorganisms, the assembly of functional genes, predicted from PICRUSt, is mainly attributed to deterministic processes in all microbial communities. The sink and source microbial communities are normally assembled using similar mechanisms, and the core microorganisms are specific to different environment types. On a global scale, deterministic processes are positively related to the community alpha diversity, microbial interaction degree and bacterial predatory-specific gene abundance. Our analysis provides a panoramic picture and regularities of global and environment-typical microbial community assemblies. IMPORTANCE With the development of sequencing technologies, the research topic of microbial ecology has evolved from the analysis of community composition to community assembly, including the relative contribution of deterministic and stochastic processes for the formation and maintenance of community diversity. Many studies have reported the microbial assembly mechanisms in various habitats, but the assembly regularities of global microbial communities remain unknown. In this study, we analyzed the EMP data set using a combined pipeline to explore the assembly mechanisms of global microbial communities, microbial sources to construct communities, core microbes in different environment types, and community-internal factors influencing assembly. The results provide a panoramic picture and rules of global and environment-typical microbial community assemblies, which enhances our understandings of the mechanisms globally controlling community diversity and species coexistence.


Assuntos
Bactérias , Microbiota , Animais , Bactérias/genética , Microbiota/genética , Interações Microbianas , Genes Bacterianos , Processos Estocásticos
11.
Nucleic Acids Res ; 51(D1): D452-D459, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36243963

RESUMO

Antimicrobial toxins help prokaryotes win competitive advantages in intraspecific or interspecific conflicts and are also a critical factor affecting the pathogenicity of many pathogens that threaten human health. Although many studies have revealed that antagonism based on antimicrobial toxins plays a central role in prokaryotic life, a database on antimicrobial toxins remains lacking. Here, we present the prokaryotic antimicrobial toxin database (PAT, http://bioinfo.qd.sdu.edu.cn/PAT/), a comprehensive data resource collection on experimentally validated antimicrobial toxins. PAT has organized information, derived from the reported literature, on antimicrobial toxins, as well as the corresponding immunity proteins, delivery mechanisms, toxin activities, structural characteristics, sequences, etc. Moreover, we also predict potential antimicrobial toxins in prokaryotic reference genomes and show the taxonomic information and environmental distribution of typical antimicrobial toxins. These details have been fully incorporated into the PAT database, where users can browse, search, download, analyse and view informative statistics and detailed information. PAT resources have already been used in our prediction and identification of prokaryotic antimicrobial toxins and may contribute to promoting the efficient investigation of antimicrobial toxin functions, the discovery of novel antimicrobial toxins, and an improved understanding of the biological roles and significance of these toxins.


Assuntos
Toxinas Biológicas , Humanos , Bases de Dados Factuais , Genoma , Células Procarióticas/metabolismo , Toxinas Biológicas/química , Toxinas Biológicas/metabolismo
12.
Invest Ophthalmol Vis Sci ; 63(11): 8, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-36227606

RESUMO

Purpose: Loss of retinoschisin (RS1) function underlies X-linked retinoschisis (XLRS) pathology. In the retina, both photoreceptor inner segments and bipolar cells express RS1. However, the loss of RS1 function causes schisis primarily in the inner retina. To understand these cell type-specific phenotypes, we decoupled RS1 effects in bipolar cells from that in photoreceptors. Methods: Bipolar cell transgene RS1 expression was achieved using two inner retina-specific promoters: (1) a minimal promoter engineered from glutamate receptor, metabotropic glutamate receptor 6 gene (mini-mGluR6/ Grm6) and (2) MiniPromoter (Ple155). Adeno-associated virus vectors encoding RS1 gene under either the mini-mGluR6 or Ple-155 promoter were delivered to the XLRS mouse retina through intravitreal or subretinal injection on postnatal day 14. Retinal structure and function were assessed 5 weeks later: immunohistochemistry for morphological characterization, optical coherence tomography and electroretinography (ERG) for structural and functional evaluation. Results: Immunohistochemical analysis of RS1expression showed that expression with the MiniPromoter (Ple155) was heavily enriched in bipolar cells. Despite variations in vector penetrance and gene transfer efficiency across the injected retinas, those retinal areas with robust bipolar cell RS1 expression showed tightly packed bipolar cells with fewer cavities and marked improvement in inner retinal structure and synaptic function as judged by optical coherence tomography and electroretinography, respectively. Conclusions: These results demonstrate that RS1 gene expression primarily in bipolar cells of the XLRS mouse retina, independent of photoreceptor expression, can ameliorate retinoschisis structural pathology and provide further evidence of RS1 role in cell adhesion.


Assuntos
Cistos , Retinosquise , Animais , Camundongos , Cistos/metabolismo , Cistos/patologia , Eletrorretinografia , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Retina/metabolismo , Retina/patologia , Células Bipolares da Retina/metabolismo , Retinosquise/genética , Retinosquise/metabolismo
13.
Int Immunopharmacol ; 111: 109165, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35987144

RESUMO

Severe acute pancreatitis (SAP) is a condition characterized by highly fatal acute inflammation and is usually associated with multiple organ dysfunction syndrome. Acute lung injury (ALI) is the most common complications of SAP, which is the accelerator of other organ dysfunction caused by SAP and the primary cause of early death due to SAP. Acadesine, an adenosine analog and an AMPK activator, has been discovered to modulate glucose and lipid metabolism, and inhibit the production of pro-inflammatory cytokines and iNOS. However, its role in SAP-ALI and its mechanism remains unclear and need to be explored. Herein, we discovered that acadesine mitigated the generation of reactive oxygen species (ROS) in human pulmonary microvascular endothelial cells (HPMECs), alleviated apoptosis and recovered barrier integrity, thereby contributing to anti-inflammatory effects in vitro and in vivo. Moreover, Nrf2 deficiency partially eliminated the effects of acadesine-induced antioxidant effects and thus weakened the protective effects on cells and Nrf2-knockout (Nrf2-/-) mice. This study demonstrates that acadesine attenuated SAP-ALI associated inflammation and tissue damage by modulating the Nrf2-dependent antioxidant pathway by triggering AMPK. These findings are of great significance for the treatment of SAP-related lung injury.


Assuntos
Lesão Pulmonar Aguda , Pancreatite , Proteínas Quinases Ativadas por AMP/metabolismo , Doença Aguda , Lesão Pulmonar Aguda/induzido quimicamente , Aminoimidazol Carboxamida/análogos & derivados , Animais , Antioxidantes/farmacologia , Células Endoteliais/metabolismo , Humanos , Inflamação/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Pancreatite/complicações , Ribonucleosídeos , Transdução de Sinais
14.
mSystems ; 7(2): e0105621, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35353010

RESUMO

Differential transcription of functionally divergent duplicate genes is critical for bacterial cells to properly and competitively function in the environment, but the transcriptional regulation mechanisms remain in mystery. Myxococcus xanthus DK1622 possesses two duplicate groELs with divergent functions. Here, we report that MXAN_4468, an orphan gene located upstream of groEL2, encodes a response regulator (RR) and is responsible for the differential expression regulation of duplicate groELs. This RR protein realizes its negative regulatory role via a novel dual-mode functioning manner: binding to the transcription repressor HrcA to enhance its transcriptional inhibition of duplicate groELs and binding to the 3' end of the MXAN_4468 sequence to specifically decrease the transcription of the following groEL2. Phosphorylation at the conserved 61st aspartic acid is required to trigger the regulatory functions of MXAN_4468. Pull-down experiment and mutation demonstrated that two noncognate CheA proteins, respectively belonging to the Che8 and Che7 chemosensory pathways, are involved in the protein phosphorylation. A transcriptome analysis, as well as the pull-down experiment, suggested that MXAN_4468 plays a global negative regulatory role in M. xanthus. This study elucidates, for the first time, the regulatory mechanism of differential transcription of bacterial duplicate groELs and suggests a global regulatory role of a dual-functional orphan RR. IMPORTANCE Multiply copied groELs require precise regulation of transcriptions for their divergent cellular functions. Here, we reported that an orphan response regulator (RR) tunes the transcriptional discrepancy of the duplicate groELs in Myxococcus xanthus DK1622 in a dual-functional mode. This RR protein has a conserved phosphorylation site, and the phosphorylation is required for the regulatory functions. Transcriptomic analysis, as well as a pull-down experiment, suggests that the RR plays a global regulatory role in M. xanthus. This study highlights that the dual-functional orphan RR might be involved in conducting the transcriptional symphony to stabilize the complex biological functions in cells.


Assuntos
Myxococcus xanthus , Myxococcus , Myxococcus/metabolismo , Proteínas de Bactérias/genética , Myxococcus xanthus/genética , Regulação da Expressão Gênica , Fosforilação
15.
J Int Med Res ; 50(2): 3000605221075506, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35118888

RESUMO

Monozygotic triplet pregnancies are very rare in assisted reproductive technology, and the relationship between monozygotic multiple pregnancies and several assisted reproductive techniques, including blastocyst transfer, remains unclear. Here, the case of a 28-year-old female patient with dichorionic quadruplet pregnancy following intracytoplasmic sperm injection and transfer of two day-3 fresh embryos, without assisted hatching, is reported. At 7 weeks following embryo transfer, the dichorionic quadruplet pregnancy, comprising monozygotic monochorionic triamniotic (MCTA) triplets plus a singleton, was detected by a transabdominal ultrasound scan. After counselling, the patient underwent selective reduction of the MCTA triplet pregnancy at 7 weeks after embryo transfer. The remaining singleton pregnancy was uneventful, resulting in a live birth at 38+ weeks. As the predictors of monozygotic multiple gestations remain poorly characterized, clinicians and patients should give great consideration to the risks associated with monozygotic multiple pregnancies, even if the patient has not undergone blastocyst transfer.


Assuntos
Gravidez de Quadrigêmeos , Injeções de Esperma Intracitoplásmicas , Adulto , Transferência Embrionária , Feminino , Humanos , Gravidez , Gravidez Múltipla , Trigêmeos
16.
Menopause ; 29(5): 627-635, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35102100

RESUMO

IMPORTANCE: Long-term sleep disturbances in menopausal women are closely related to cardiovascular disorders, metabolic disorders, and cognitive impairment. At present, hormone therapy (HT) is a standard treatment for menopausal symptoms. However, it remains unclear whether HT can improve sleep quality. OBJECTIVE: We did a systematic review and meta-analysis to assess the effects of different HT regimens on menopausal sleep quality. EVIDENCE REVIEW: We systematically searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, PsycINFO, CINAHL, and Web of Science for randomized controlled trials of menopausal HT on sleep disturbances up to June 14,2021. Information about ongoing and unpublished trials was collected by searching WHOICTRP and ClinicalTrials.gov. Our primary outcome was sleep quality with objective measurements. We estimated the standardized mean difference (SMD) using random-effects models. FINDINGS: We identified a total of 3,059 studies and finally included 15 studies in the meta-analysis. Compared with placebo, HT improved self-reported sleep outcomes (SMD = -0.13; 95% CI, -0.18 to -0.08, P  < 0.00001 and I2 = 41%), but not sleep parameters measured by polysomnography. Subgroup analyses according to the regimen of HT showed that 17ß-estradiol (17ß-E2) (SMD = -0.34; 95% CI, -0.51 to -0.17, P  < 0.0001, and I2 = 0%) and conjugated equine estrogens (SMD = -0.10; 95% CI, -0.12 to -0.07, P  < 0.00001, and I2 = 0%) improved sleep quality. Moreover, transdermal administration (SMD = -0.35; 95% CI, -0.64 to -0.06, and P  = 0.02) was more beneficial than oral (SMD = -0.10; 95% CI, -0.14 to -0.07, and P  < 0.00001). In addition, the combination of estrogen and progesterone had a positive effect on sleep disturbance (SMD = -0.10; 95% CI, -0.13 to -0.07, P  < 0.00001, and I2 = 0%), while estrogen monotherapy did not. The results showed that estrogen/micronized progesterone (SMD = -0.22; 95% CI, -0.37 to -0.06, P = 0.007, and I2 = 0%) and estrogen/medroxyprogesterone acetate (SMD = -0.10; 95% CI, -0.13 to -0.07, P  < 0.00001, and I2 = 0%) could alleviate sleep disturbance. CONCLUSIONS AND RELEVANCE: HT has a beneficial effect on sleep disturbance to some extent, and the formulations and routes of administration of hormonal agents influence the effect size.


Assuntos
Progesterona , Qualidade do Sono , Estrogênios/uso terapêutico , Feminino , Terapia de Reposição Hormonal , Humanos , Menopausa , Progesterona/uso terapêutico
17.
Artigo em Inglês | MEDLINE | ID: mdl-37933248

RESUMO

Optogenetic techniques have been developed to allow control over the activity of selected cells within a highly heterogeneous tissue, using a combination of genetic engineering and light. Optogenetics employs natural and engineered photoreceptors, mostly of microbial origin, to be genetically introduced into the cells of interest. As a result, cells that are naturally light-insensitive can be made photosensitive and addressable by illumination and precisely controllable in time and space. The selectivity of expression and subcellular targeting in the host is enabled by applying control elements such as promoters, enhancers and specific targeting sequences to the employed photoreceptor-encoding DNA. This powerful approach allows precise characterization and manipulation of cellular functions and has motivated the development of advanced optical methods for patterned photostimulation. Optogenetics has revolutionized neuroscience during the past 15 years and is primed to have a similar impact in other fields, including cardiology, cell biology and plant sciences. In this Primer, we describe the principles of optogenetics, review the most commonly used optogenetic tools, illumination approaches and scientific applications and discuss the possibilities and limitations associated with optogenetic manipulations across a wide variety of optical techniques, cells, circuits and organisms.

18.
Opt Lett ; 46(16): 3969-3972, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388787

RESUMO

A number of applications require x rays of both high flux and narrow bandwidth. In this work, we experimentally demonstrate the high-efficiency generation of narrowband soft x rays from carbon nanotube foams irradiated by a femtosecond laser pulse at an intensity of 1019W/cm2. The building blocks of the foam, single-walled carbon nanotube bundles with diameters smaller than the laser skin length can be volumetrically heated and fully ionized on a femtosecond time scale. The three-dimensional network structure of the foam permits deep penetration and drastic absorption of the laser pulse, and results in bright line emissions without prominent Stark broadening. A single-shot yield of 3×1014photons in the carbon Lyα line at 3.37 nm was measured with a bandwidth of 0.013 nm.

19.
Front Cell Dev Biol ; 9: 672693, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33996830

RESUMO

Cancer stem cell (CSC) is thought to be the major cause of radio-resistance and relapse post radiotherapy (RT). Recently ultra-high dose rate "FLASH-RT" evokes great interest for its decreasing normal tissue damages while maintaining tumor responses compared with conventional dose rate RT. However, the killing effect and mechanism of FLASH irradiation (FLASH-IR) on CSC and normal cancer cell are still unclear. Presently the radiation induced death profile of CSC and normal cancer cell were studied. Cells were irradiated with FLASH-IR (∼109 Gy/s) at the dose of 6-9 Gy via laser-accelerated nanosecond particles. Then the ratio of apoptosis, pyroptosis and necrosis were determined. The results showed that FLASH-IR can induce apoptosis, pyroptosis and necrosis in both CSC and normal cancer cell with different ratios. And CSC was more resistant to radiation than normal cancer cell under FLASH-IR. Further experiments tracing lysosome and autophagy showed that CSCs had higher levels of lysosome and autophagy. Taken together, our results suggested that the radio-resistance of CSC may associate with the increase of lysosome-mediated autophagy, and the decrease of apoptosis, necrosis and pyroptosis. To our limited knowledge, this is the first report shedding light on the killing effects and death pathways of CSC and normal cancer cell under FLASH-IR. By clarifying the death pathways of CSC and normal cancer cell under FLASH-IR, it may help us improve the understanding of the radio-resistance of CSC and thus help to optimize the future clinical FLASH treatment plan.

20.
Front Cell Dev Biol ; 9: 672929, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33996831

RESUMO

Ultra-high dose rate FLASH irradiation (FLASH-IR) has got extensive attention since it may provide better protection on normal tissues while maintain tumor killing effect compared with conventional dose rate irradiation. The FLASH-IR induced protection effect on normal tissues is exhibited as radio-resistance of the irradiated normal cells, and is suggested to be related to oxygen depletion. However, the detailed cell death profile and pathways are still unclear. Presently normal mouse embryonic fibroblast cells were FLASH irradiated (∼109 Gy/s) at the dose of ∼10-40 Gy in hypoxic and normoxic condition, with ultra-fast laser-generated particles. The early apoptosis, late apoptosis and necrosis of cells were detected and analyzed at 6, 12, and 24 h post FLASH-IR. The results showed that FLASH-IR induced significant early apoptosis, late apoptosis and necrosis in normal fibroblast cells, and the apoptosis level increased with time, in either hypoxic or normoxic conditions. In addition, the proportion of early apoptosis, late apoptosis and necrosis were significantly lower in hypoxia than that of normoxia, indicating that radio-resistance of normal fibroblast cells under FLASH-IR can be enhanced by hypoxia. To further investigate the apoptosis related profile and potential pathways, mitochondria dysfunction cells resulting from loss of cytochrome c (cyt c-/-) were also irradiated. The results showed that compared with irradiated normal cells (cyt c+/+), the late apoptosis and necrosis but not early apoptosis proportions of irradiated cyt c-/- cells were significant decreased in both hypoxia and normoxia, indicating mitochondrial dysfunction increased radio-resistance of FLASH irradiated cells. Taken together, to our limited knowledge, this is the first report shedding light on the death profile and pathway of normal and cyt c-/- cells under FLASH-IR in hypoxic and normoxic circumstances, which might help us improve the understanding of the FLASH-IR induced protection effect in normal cells, and thus might potentially help to optimize the future clinical FLASH treatment.

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