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Science Advances Jun 2024Nitrogenase plays a key role in the global nitrogen cycle; yet, the evolutionary history of nitrogenase and, particularly, the sequence of appearance between the...
Nitrogenase plays a key role in the global nitrogen cycle; yet, the evolutionary history of nitrogenase and, particularly, the sequence of appearance between the homologous, yet distinct NifDK (the catalytic component) and NifEN (the cofactor maturase) of the extant molybdenum nitrogenase, remains elusive. Here, we report the ability of NifEN to reduce N at its surface-exposed L-cluster ([FeSC]), a structural/functional homolog of the M-cluster (or cofactor; [(-homocitrate)MoFeSC]) of NifDK. Furthermore, we demonstrate the ability of the L-cluster-bound NifDK to mimic its NifEN counterpart and enable N reduction. These observations, coupled with phylogenetic, ecological, and mechanistic considerations, lead to the proposal of a NifEN-like, L-cluster-carrying protein as an ancient nitrogenase, the exploration of which could shed crucial light on the evolutionary origin of nitrogenase and related enzymes.
Topics: Nitrogenase; Phylogeny; Nitrogen; Molybdoferredoxin; Models, Molecular; Bacterial Proteins; Nitrogen Fixation
PubMed: 38865457
DOI: 10.1126/sciadv.ado6169 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... May 2024To investigate the mechanisms that mediate the neuroprotective effect of the intestinal microbial metabolite sodium butyrate (NaB) in a mouse model of Parkinson's...
OBJECTIVE
To investigate the mechanisms that mediate the neuroprotective effect of the intestinal microbial metabolite sodium butyrate (NaB) in a mouse model of Parkinson's disease (PD) the gut-brain axis.
METHODS
Thirty-nine 7-week-old male C57BL/6J mice were randomized equally into control group, PD model group, and NaB treatment group. In the latter two groups, PD models were established by intraperitoneal injection of 30 mg/kg 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) once daily for 5 consecutive days, and normal saline was injected in the control group. After modeling, the mice received daily gavage of NaB (300 mg/kg) or an equal volume of saline for 14 days. Behavioral tests were carried out to assess the changes in motor function of the mice, and Western blotting was performed to detect the expressions of tyrosine hydroxylase (TH) and -synuclein (-syn) in the striatum and nuclear factor-κB (NF-κB), tumor necrosis factor (TNF-), interleukin 6 (IL-6), and the tight junction proteins ZO-1, Occludin, and Claudinin the colon. HE staining was used to observe inflammatory cell infiltration in the colon of the mice. RNA sequencing analysis was performed to identify the differentially expressed genes in mouse colon tissues, and their expressions were verified using qRT-PCR and Western blotting.
RESULTS
The mouse models of PD with NaB treatment showed significantly increased movement speed and pulling strength of the limbs with obviously upregulated expressions of TH, Occludin, and Claudin and downregulated expressions of -syn, NF-κB, TNF-, and IL-6 (all < 0.05). HE staining showed that NaB treatment significantly ameliorated inflammatory cell infiltration in the colon of the PD mice. RNA sequencing suggested that Bmal1 gene probably mediated the neuroprotective effect of NaB in PD mice ( < 0.05).
CONCLUSION
NaB can improve motor dysfunction, reduce dopaminergic neuron loss in the striatum, and ameliorate colonic inflammation in PD mice possibly through a mechanism involving Bmal1.
Topics: Animals; Mice; Butyric Acid; Male; Mice, Inbred C57BL; Neuroprotective Agents; Disease Models, Animal; Parkinson Disease; alpha-Synuclein; Tumor Necrosis Factor-alpha; NF-kappa B; Interleukin-6; Tyrosine 3-Monooxygenase; 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Corpus Striatum; Occludin; Brain-Gut Axis
PubMed: 38862445
DOI: 10.12122/j.issn.1673-4254.2024.05.09 -
BMJ Open Jun 2024This systematic review and meta-analysis aimed to comprehensively assess the impact of weekly iron-folic acid supplementation (WIFAS) on the nutrition, health and... (Meta-Analysis)
Meta-Analysis
Weekly iron-folic acid supplementation and its impact on children and adolescents iron status, mental health and school performance: a systematic review and meta-analysis in sub-Saharan Africa.
OBJECTIVE
This systematic review and meta-analysis aimed to comprehensively assess the impact of weekly iron-folic acid supplementation (WIFAS) on the nutrition, health and educational outcomes of children and adolescents in sub-Saharan Africa.
DESIGN
A systematic review and meta-analysis was used.
DATA SOURCES
Five databases, namely, MEDLINE, Scopus, Web of Science, Cochrane Library and Google Scholar, were systematically searched for relevant articles up to 23 August 2023.
ELIGIBILITY CRITERIA
It was focused on randomised controlled trials involving children and adolescents in sub-Saharan Africa, exploring the effects of iron supplementation on various outcomes, such as serum ferritin and haemoglobin levels, anaemia, mental health and school performance.
DATA EXTRACTION AND SYNTHESIS
The Joanna Briggs Institute Critical Appraisal tools were used for quality assessment, with two independent reviewers thoroughly evaluating each paper. Using the Cochrane risk of bias tool, we evaluated the certainty of evidence such as the risk of bias, inconsistency, indirectness, imprecision and publication bias.
RESULTS
A systematic review of 10 articles revealed that WIFAS significantly increased serum ferritin levels in adolescent girls (Hedge's g=0.53, 95% CI 0.28 to 0.78; heterogeneity I=41.21%, p<0.001) and haemoglobin levels in school-aged children (Hedge's g=0.37, 95% CI 0.01 to 0.73; heterogeneity I=91.62%, p<0.001). The analysis further demonstrated a substantial reduction in the risk of anaemia by 20% (risk ratio=0.8, 95% CI 0.69 to 0.93; heterogeneity I=28.12%, p<0.001).
CONCLUSION
WIFAS proved effective in enhancing serum ferritin and haemoglobin concentrations and lowering the risk of anaemia in school-aged children and adolescents compared with a placebo. Similarly, there are not enough studies to examine the effects of WIFAS on school performance. However, information regarding mental health problems, mortality and potential side effects remains insufficient.
PROSPERO REGISTRATION NUMBER
CRD42023397898.
Topics: Humans; Child; Adolescent; Dietary Supplements; Africa South of the Sahara; Mental Health; Iron; Folic Acid; Ferritins; Anemia, Iron-Deficiency; Hemoglobins; Randomized Controlled Trials as Topic; Female; Nutritional Status
PubMed: 38862227
DOI: 10.1136/bmjopen-2024-084033 -
Molecular Brain Jun 2024Chronic perturbations of neuronal activity can evoke homeostatic and new setpoints for neurotransmission. Using chemogenetics to probe the relationship between neuronal...
Chronic perturbations of neuronal activity can evoke homeostatic and new setpoints for neurotransmission. Using chemogenetics to probe the relationship between neuronal cell types and behavior, we recently found reversible decreases in dopamine (DA) transmission, basal behavior, and amphetamine (AMPH) response following repeated stimulation of DA neurons in adult mice. It is unclear, however, whether altering DA neuronal activity via chemogenetics early in development leads to behavioral phenotypes that are reversible, as alterations of neuronal activity during developmentally sensitive periods might be expected to induce persistent effects on behavior. To examine the impact of developmental perturbation of DA neuron activity on basal and AMPH behavior, we expressed excitatory hM3D(Gq) in postnatal DA neurons in TH-Cre and WT mice. Basal and CNO- or AMPH-induced locomotion and stereotypy was evaluated in a longitudinal design, with clozapine N-oxide (CNO, 1.0 mg/kg) administered across adolescence (postnatal days 15-47). Repeated CNO administration did not impact basal behavior and only minimally reduced AMPH-induced hyperlocomotor response in adolescent TH-Cre mice relative to WT littermate controls. Following repeated CNO administration, however, AMPH-induced stereotypic behavior robustly decreased in adolescent TH-Cre mice relative to controls. A two-month CNO washout period rescued the diminished AMPH-induced stereotypic behavior. Our findings indicate that the homeostatic compensations that take place in response to chronic hM3D(Gq) stimulation during adolescence are temporary and are dependent on ongoing chemogenetic stimulation.
Topics: Animals; Amphetamine; Dopaminergic Neurons; Stereotyped Behavior; Clozapine; Locomotion; Mice; Male; Motor Activity; Mice, Transgenic; Tyrosine 3-Monooxygenase; Behavior, Animal; Integrases
PubMed: 38858755
DOI: 10.1186/s13041-024-01110-9 -
Journal of Inorganic Biochemistry Sep 2024CH functionalization, a promising frontier in modern organic chemistry, facilitates the direct conversion of inert CH bonds into many valuable functional groups. Despite... (Review)
Review
CH functionalization, a promising frontier in modern organic chemistry, facilitates the direct conversion of inert CH bonds into many valuable functional groups. Despite its merits, traditional homogeneous catalysis, often faces challenges in efficiency, selectivity, and sustainability towards this transformation. In this context, artificial metalloenzymes (ArMs), resulting from the incorporation of a catalytically-competent metal cofactor within an evolvable protein scaffold, bridges the gap between the efficiency of enzymatic transformations and the versatility of transition metal catalysis. Accordingly, ArMs have emerged as attractive tools for various challenging catalytic transformations. Additionally, the coming of age of directed evolution has unlocked unprecedented avenues for optimizing enzymatic catalysis. Taking advantage of their genetically-encoded protein scaffold, ArMs have been evolved to catalyze various CH functionalization reactions. This review delves into the recent developments of ArM-catalyzed CH functionalization reactions, highlighting the benefits of engineering the second coordination sphere around a metal cofactor within a host protein.
Topics: Metalloproteins; Catalysis; Protein Engineering; Hydrogen
PubMed: 38852295
DOI: 10.1016/j.jinorgbio.2024.112621 -
ACS Nano Jun 2024Ferritin, a spherical protein shell assembled from 24 subunits, functions as an efficient iron storage and release system through its channels. Understanding how various...
Ferritin, a spherical protein shell assembled from 24 subunits, functions as an efficient iron storage and release system through its channels. Understanding how various chemicals affect the structural behavior of ferritin is crucial for unravelling the origins of iron-related diseases in living organisms including humans. In particular, the influence of chemicals on ferritin's dynamics and iron release is barely explored at the single-protein level. Here, by employing optical nanotweezers using double-nanohole (DNH) structures, we examined the effect of ascorbic acid (reducing reagent) and pH on individual ferritin's conformational dynamics. The dynamics of ferritin increased as the concentration of ascorbic acid approached saturation. At pH 2.0, ferritin exhibited significant structural fluctuations and eventually underwent a stepwise disassembly into fragments. This work demonstrated the disassembly pathway and kinetics of a single ferritin molecule in solution. We identified four critical fragments during its disassembly pathway, which are 22-mer, 12-mer, tetramer, and dimer subunits. Moreover, we present single-molecule evidence of the cooperative disassembly of ferritin. Interrogating ferritin's structural change in response to different chemicals holds importance for understanding their roles in iron metabolism, hence facilitating further development of medical treatments for its associated diseases.
Topics: Ferritins; Kinetics; Optical Tweezers; Ascorbic Acid; Hydrogen-Ion Concentration; Protein Conformation; Iron; Humans
PubMed: 38850556
DOI: 10.1021/acsnano.4c01221 -
Cancer Control : Journal of the Moffitt... 2024Our objective is to develop a predictive model utilizing the ferritin and transferrin ratio (FTR) and clinical factors to forecast overall survival (OS) in breast cancer...
BACKGROUND
Our objective is to develop a predictive model utilizing the ferritin and transferrin ratio (FTR) and clinical factors to forecast overall survival (OS) in breast cancer (BC) patients.
METHODS
We conducted a retrospective analysis of clinical data from 2858 BC patients diagnosed between 2013 and 2021. Subsequently, the cohort of 2858 BC patients underwent random assignment into distinct subsets: a training cohort comprising 2002 patients and a validation cohort comprising 856 patients, maintaining a proportional ratio of 7:3. Employing multivariable Cox regression analysis within the training cohort, we derived a prognostic nomogram. The predictive performance was assessed using calibration curves, C-index, and decision curve analysis.
RESULTS
The final prognostic model included the TNM stage, subtype, hemoglobin levels, and the ferritin-transferrin ratio. The nomogram achieved a C-index of .794 (95% CI: .777-.810). The nomogram demonstrated superior predictive accuracy for OS at 3, 5, and 7 years for BC, with area under the time-dependent curves of .812, .782, and .773, respectively. These values notably outperformed those of the conventional TNM stage. Decision curve analysis reaffirmed the greater net benefit of our nomogram compared to the TNM stage. These findings were subsequently validated in the independent validation cohort.
CONCLUSION
The FTR-based prognostic model may predict a patient's OS better than the TNM stage in a clinical setting. The nomogram can provide an early, affordable, and reliable tool for survival prediction, as well as aid clinicians in treatment option-making and prognosis evaluation. However, further multi-center prospective trials are required to confirm the reliability of the existing nomogram.
Topics: Humans; Nomograms; Breast Neoplasms; Female; Ferritins; Transferrin; Middle Aged; Retrospective Studies; Prognosis; Adult; Aged; Neoplasm Staging
PubMed: 38850515
DOI: 10.1177/10732748241261553 -
General and Comparative Endocrinology Jun 2024Spodoptera litura commonly known as the cutworm, is among the most destructive lepidopteran pests affecting over 120 plants species. The powerful destructive nature of...
Spodoptera litura commonly known as the cutworm, is among the most destructive lepidopteran pests affecting over 120 plants species. The powerful destructive nature of this lepidopteran is attributable to its high reproductive capacity. The testicular fusion that occurs during metamorphosis from larvae to pupa in S.litura positively influences the reproductive success of the offspring. In contrast, Bombyx mori, the silkworm, retains separate testes throughout its life and does not undergo this fusion process. Microscopic examination reveals that during testicular fusion in S.litura, the peritoneal sheath becomes thinner and more translucent, whereas in B.mori, the analogous region thickens. The outer basement membrane in S.litura exhibits fractures, discontinuity, and uneven thickness accompanied by a significant presence of cellular secretions, large cell size, increased vesicles, liquid droplets, and a proliferation of rough endoplasmic reticulum and mitochondria. In contrast, the testicular peritoneal sheath of B.mori at comparable developmental stage exhibits minimal change. Comparative transcriptomic analysis of the testicular peritoneal sheath reveals a substantial difference in gene expression between the two species. The disparity in differential expressed genes (DEGs) is linked to an enrichment of numerous transcription factors, intracellular signaling pathways involving Ca and GTPase, as well as intracellular protein transport and signaling pathways. Meanwhile, structural proteins including actin, chitin-binding proteins, membrane protein fractions, cell adhesion, extracellular matrix proteins are predominantly identified. Moreover, the study highlights the enrichment of endopeptidases, serine proteases, proteolytic enzymes and matrix metalloproteins, which may play a role in the degradation of the outer membrane. Five transcription factors-Slforkhead, Slproline, Slcyclic, Slsilk, and SlD-ETS were identified, and their expression pattern were confirmed by qRT-PCR. they are candidates for participating in the regulation of testicular fusion. Our findings underscore significant morphological and trancriptomic variation in the testicular peritoneal sheath of S.litura compared to the silkworm, with substantial changes at the transcriptomic level coinciding with testicular fusion. The research provides valuable clues for understanding the complex mechanisms underlying this unique phenomenon in insects.
PubMed: 38848820
DOI: 10.1016/j.ygcen.2024.114562 -
JAMA Network Open Jun 2024The prevalence of iron deficiency varies widely according to how it is defined.
IMPORTANCE
The prevalence of iron deficiency varies widely according to how it is defined.
OBJECTIVE
To compare the prevalence of iron deficiency among women using 3 different definitions.
DESIGN, SETTING, AND PARTICIPANTS
The cross-sectional Hemochromatosis and Iron Overload Screening Study (HEIRS; 2000-2006) evaluated the prevalence, determinants, and outcomes of hemochromatosis and other iron-related disorders. Multiethnic, primary care-based screening (2001-2003) was performed at 5 field centers (4 in the US and 1 in Canada). Volunteer women aged 25 years and older were recruited at primary care venues associated with the field centers. Data were analyzed from June to December 2023.
MAIN OUTCOMES AND MEASURES
Measures included transferrin saturation, serum ferritin level, and self-reported age, pregnancy, and race and ethnicity. Three iron deficiency definitions were studied: (1) combined transferrin saturation less than 10% and serum ferritin less than 15 ng/mL (HEIRS), (2) serum ferritin less than 15 ng/mL (World Health Organization [WHO]), and (3) serum ferritin less than 25 ng/mL (a threshold for iron-deficient erythropoiesis [IDE]).
RESULTS
Among 62 685 women (mean [SD] age, 49.58 [14.27] years), 1957 women (3.12%) had iron deficiency according to the HEIRS definition, 4659 women (7.43%) had iron deficiency according to the WHO definition, and 9611 women (15.33%) had iron deficiency according to the IDE definition. Among 40 381 women aged 25 to 54 years, 1801 women (4.46%) had iron deficiency according to HEIRS, 4267 women (10.57%) had iron deficiency according to WHO, and 8573 women (21.23%) had iron deficiency according to IDE. Prevalence rates of iron deficiency among 2039 women aged 25 to 44 years who reported pregnancy were 5.44% (111 women) according to HEIRS, 18.05% (368 women) according to WHO, and 36.10% (736 women) according to IDE. Iron deficiency prevalence by the 3 respective definitions increased significantly in each racial and ethnic group and was significantly higher among Black and Hispanic participants than Asian and White participants. The relative iron deficiency prevalence among the 62 685 women increased 2.4-fold (95% CI, 2.3-2.5; P < .001) using the WHO definition and increased 4.9-fold (95% CI, 4.7-5.2; P < .001) using the IDE definition.
CONCLUSIONS AND RELEVANCE
Three definitions of iron deficiency were associated with significantly different prevalence of iron deficiency in women, regardless of self-reported age, pregnancy, or race and ethnicity. Using higher serum ferritin thresholds to define iron deficiency could lead to diagnosis and treatment of more women with iron deficiency and greater reduction of related morbidity.
Topics: Humans; Female; Prevalence; Canada; Adult; Cross-Sectional Studies; Middle Aged; United States; Anemia, Iron-Deficiency; Ferritins; Transferrin; Pregnancy; Iron Deficiencies; Aged
PubMed: 38848068
DOI: 10.1001/jamanetworkopen.2024.13967 -
Archives of Dermatological Research Jun 2024Telogen effluvium is characterized by excessive hair shedding usually following a stressful event. Ferritin has been used in clinical practice as a biomarker of...
Telogen effluvium is characterized by excessive hair shedding usually following a stressful event. Ferritin has been used in clinical practice as a biomarker of nonanemic iron deficiency in cases of telogen effluvium. During the years of the COVID19 pandemic, telogen effluvium was reported as a part of post covid manifestations. As ferritin was also a biomarker for inflammation in cases with covid infection, this study was designed to evaluate the value of ferritin in cases with postcovid telogen effluvium one hundred patients recovering from covid 19 for 4-12 weeks were included in the study, detailed drug and laboratory history was obtained and serum ferritin level was measured. the mean serum level of ferritin among telogen effluvium patients was significantly lower than controls (68.52 ± 126 and 137 ± 137.597 ug/L respectively). Patients with telogen effluvium used significantly more azithromycin and ivermectin and significantly less vitamin C, D, lactoferrin and zinc than the controls Although serum ferritin is lower among telogen effluvium patients, it was still higher than the cutoff value for diagnosing nonanemic iron deficiency, we suggest that it will not be a good biomarkers in these cases. Our secondary outcomes showed that dietary supplements used during active infection such as vitamin C, D, lactoferrin and zinc might have a preventive value on postcovid hair loss, while azithromycin and ivermectin could have a negative long term effect on telogen effluvium.
Topics: Humans; Ferritins; COVID-19; Biomarkers; Female; Adult; Male; Case-Control Studies; Dietary Supplements; Middle Aged; SARS-CoV-2; Azithromycin; Ivermectin; Alopecia; Hair; Young Adult
PubMed: 38844670
DOI: 10.1007/s00403-024-03004-1