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1.
J Org Chem ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662442

RESUMO

In this report, a tert-butyl nitrite (TBN)-mediated straightforward metal-free approach has been presented for the synthesis of a diverse range of C-3-substituted indazole-indole hybrids using readily accessible 2-(indolin-3-ylidenemethyl)aniline derivatives. This strategy is proposed to occur via a diazonium salt intermediate that is capable of cascade isomerization and intramolecular C-N bond formation through a 5-endo-dig cyclization to achieve a wide variety of indazole-indole hybrids in good yields.

2.
ACS Appl Bio Mater ; 7(4): 2554-2568, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38574371

RESUMO

Multidrug-resistant bacteria are a serious problem in biomedical applications that decrease the wound healing process and increase the mortality rate. Therefore, in this study, we have prepared a green-synthesized silver-nanoparticle-encapsulated mucilage microsphere (HMMS@GSNP) from Hibiscus rosa sinensis leaves and applied it to pathogen-infected burn and excision wounds. Biophysical properties like size, polydispersity index, absorbance capacity, and drug release were measured by different techniques like field-emission scanning electron microscopy, dynamic light scattering, swelling ratio, etc. The strong antibacterial activity of a HMMS@GSNP microsphere was measured by minimum inhibitory concentration assay, minimum bactericidal concentration assay, and agar well diffusion methods. The HMMS@GSNP microsphere enhanced the cell viability, cell proliferation, migration, antioxidant, and antiinflammation activity compared to untreated GSNP and HMMS, as quantified by MTT assay, BrdU assay, scratch wound assay, reactive oxygen species scavenging assay, and Western blot analysis, respectively. In the in vivo experiment, we used a methicillin-resistant Staphylococcus aureus bacteria-infected, burn-and-excision-wound-created male BALB/c mice model. The HMMS@GSNP-treated burn-and-excision-wound-infected mice showed significant results compared to other groups (untreated, Silverex Ionic Gel, AgNO3, HMMS, and GSNP), and the mice tissues were utilized for bacteria count, immunoblot analysis, histological studies, and real-time polymerase chain reaction. Thus, the HMM@GSNP microsphere is an excellent therapeutic material that can be used as a topical agent for the management of chronic wound therapy.


Assuntos
Queimaduras , Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Masculino , Camundongos , Animais , Prata , Microesferas , Queimaduras/tratamento farmacológico
3.
J Health Popul Nutr ; 43(1): 48, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38576058

RESUMO

BACKGROUND: Integrated-pathy aims to integrate modern medicine with traditional systems via applying the holistic approach of Ayurveda, Yoga, and natural medicine. This is important for addressing the challenges surrounding the delivery of long-term palliative care for chronic ailments including cancer. The prime intent of this study was to substantiate the underlying hypothesis behind the differential and integrative approach having a positive impact on Quality of Life of cancer patients. STUDY DESIGN: Cross-sectional Observational study. METHODS: A standardized questionnaire was developed and used, after obtaining written informed consent from patients to assess the impact of Integrated-pathy on patients (n = 103) diagnosed with cancer receiving care at Patanjali Yoggram. The research was carried out over 8 months. All participants received a uniform treatment protocol as prescribed by Patanjali. For the sample size determination and validation, α and 1-ß was calculated and for the significance of the pre- and post-treatment QoL ratings, Shapiro wilk test and other descriptive statistics techniques were explored. RESULTS: A total of 103 patients seeking cancer special-healthcare were interviewed, out of which 39 (37.86%) remained finally based on the inclusion/exclusion criteria with age (25-65 years), types of cancers (Carcinoma and Sarcoma), chemotherapy/radiotherapy received or not, before opting Integrated-pathy. Follow-ups revealed a significant increase in the QoL (17.91%) after receiving the integrated therapy over a course of at least 1 month. Further, a significant reduction in cancer-related pain followed by an increase in QoL index was reported in the patients. Shapiro-wilk test revealed significant pairing (p < 0.001) with validation of the model using test. CONCLUSIONS: To bolster evidence-based backing for Integrated-pathy, there is a need for clearly delineated clinical indicators that are measurable and trackable over time. Clinical investigators are encouraged to incorporate Integrated-pathy into their proposed interventions and conduct analogous studies to yield sustained advantages in the long run.


Assuntos
Neoplasias , Qualidade de Vida , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Transversais , Neoplasias/complicações , Neoplasias/terapia , Fadiga/etiologia , Fadiga/terapia
4.
Science ; 384(6691): eabo7027, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38574142

RESUMO

Macrophages are functionally heterogeneous cells essential for apoptotic cell clearance. Apoptotic cells are defined by homogeneous characteristics, ignoring their original cell lineage identity. We found that in an interleukin-4 (IL-4)-enriched environment, the sensing of apoptotic neutrophils by macrophages triggered their tissue remodeling signature. Engulfment of apoptotic hepatocytes promoted a tolerogenic phenotype, whereas phagocytosis of T cells had little effect on IL-4-induced gene expression. In a mouse model of parasite-induced pathology, the transfer of macrophages conditioned with IL-4 and apoptotic neutrophils promoted parasitic egg clearance. Knockout of phagocytic receptors required for the uptake of apoptotic neutrophils and partially T cells, but not hepatocytes, exacerbated helminth infection. These findings suggest that the identity of apoptotic cells may contribute to the development of distinct IL-4-driven immune programs in macrophages.


Assuntos
Apoptose , Interleucina-4 , Macrófagos , Fagocitose , Esquistossomose mansoni , Animais , Camundongos , Apoptose/imunologia , Hepatócitos/imunologia , Interleucina-4/genética , Interleucina-4/metabolismo , Macrófagos/imunologia , Camundongos Knockout , Neutrófilos/imunologia , Fagocitose/imunologia , Esquistossomose mansoni/genética , Esquistossomose mansoni/imunologia , Modelos Animais de Doenças
5.
Biophys Chem ; 307: 107195, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38325036

RESUMO

This paper delves into an investigation of the solubility characteristics of L-tryptophan within binary solvent systems containing aqueous acetonitrile. The primary emphasis of the study revolves around assessments based on mole fractions. The study utilizes these solubility values to assess thermodynamic constraints, including solution entropies and solution transfer free energetics. The calculated thermodynamic energies are correlated with interaction parameters, including Gibbs free energies and entropies, pertaining to the transfer of L-tryptophanfrom water to binary solvent blends of acetonitrile and water. Mathematical expressions are utilized to determine the transfer Gibbs free energies for chemical interactions, and the consequent entropies are clarified within the framework of solvent-solvent interactions. To expound upon the stability of L-tryptophan within the water-acetonitrile mixed system, we investigate the energetic aspects related to the transfer of chemicals Gibbs free energies. Additionally, standard temperature (298.15 K) is employed to calculate various related physicochemical parameters of solute/solvent.


Assuntos
Triptofano , Água , Temperatura , Solubilidade , Termodinâmica , Solventes
6.
Biomed Mater ; 19(3)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38387054

RESUMO

Mucilage is a sticky substance found in various plants and microorganisms and is made up of proteins and polysaccharides. Mucilage fromHibiscus rosa sinensisisis a complex polysaccharide traditionally used to treat different skin diseases. In our study, we fabricated mucilage polymer fromHibiscus rosa sinensisleaves and evaluated its potential application in second-degree burns and excision wounds. The physical properties of Hibiscus mucilage (HM) polymer were demonstrated by using Ultraviolet-visible absorption spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, dynamic light scattering, Scanning electron microscopy, Brunauer-Emmett-Tellerand, Swelling ratio. The human cell lines WI-38, and HaCaT have been used forin-vitroexperiments like MTT, scratch wound, BrdU, ROS scavenging assays, and western blot analysis. The results of the MTT, scratch-wound, and BrdU assay indicated that the HM polymer is nontoxic in nature and also enhances both the properties of cellular migration and proliferation, respectively. On the other hand, the result of the ROS scavenging assay suggested that HM polymer enhances the antioxidant activity of cells while the western blot analysis designated that the HM polymer treatment caused downregulation of the pro-inflammatory cytokine IFN-γand upregulation of the pAkt (Serine 473) protein, and TGF-ß1 signaling pathway. Therefore, allin-vitroexperimental studies recommended that HM polymer is biocompatible and has antioxidant and anti-inflammatory effects. In thein vivoexperiment, second-degree burns and excision wounds were created on the dorsal surface of male BALB/c mice. After the sixth day of HM polymer treatment have developed new tissue, hair follicles, blood vessels,α-SMA, and Collagen type-1 fiber on the burn and excision wound area while the 11th day of HM polymer treatment cured the wound area significantly. Therefore, it could be contemplated that HM polymer is a potential agent for treating different wounds in the near future.


Assuntos
Queimaduras , Rosa , Dermatopatias , Camundongos , Animais , Humanos , Cicatrização , Extratos Vegetais/química , Bromodesoxiuridina , Espécies Reativas de Oxigênio , Queimaduras/terapia
8.
J Appl Microbiol ; 135(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38093454

RESUMO

AIMS: The purpose of this study was to synthesize a nanoform of eugenol (an important phytochemical with various pharmacological potentials) and to investigate its antibiofilm efficacy on Pseudomonas aeruginosa biofilm. METHODS AND RESULTS: Colloidal suspension of eugenol-nanoparticles (ENPs) was synthesized by the simple ultrasonic cavitation method through the emulsification of hydrophobic eugenol into hydrophilic gelatin. Thus, the nanonization process made water-insoluble eugenol into water-soluble nano-eugenol, making the nanoform bioavailable. The size of the ENPs was 20-30 nm, entrapment efficiency of eugenol within gelatin was 80%, and release of eugenol from the gelatin cap was slow and sustained over 5 days. Concerning the clinically relevant pathogen P. aeruginosa, ENPs had higher antibiofilm (for both formation and eradication) activities than free eugenol. Minimal biofilm inhibitory concentration and minimal biofilm eradication concentration of ENP on P. aeruginosa biofilm were 2.0 and 4.0 mM, respectively. In addition, the measurement of P. aeruginosa biofilm biomass, biofilm thickness, amount of biofilm extra-polymeric substance, cell surface hydrophobicity, cell swarming and twitching efficiencies, cellular morphology, and biofilm formation in catheter demonstrated that the antibiofilm efficacy of nano-eugenol was 30%-40% higher than that of bulk eugenol. CONCLUSION: These results signify that future pharmacological and clinical studies are very much required to investigate whether ENPs can act as an effective drug against P. aeruginosa biofilm-mediated diseases. Thus, the problem of intrinsic antibiotic tolerance of biofilm-forming cells may be minimized by ENPs. Moreover, ENP may be used as a potential catheter-coating agent to inhibit pseudomonal colonization on catheter surfaces and, therefore, to reduce catheter-associated infections and complications.


Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Humanos , Eugenol/farmacologia , Gelatina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Biofilmes , Água/farmacologia , Testes de Sensibilidade Microbiana
9.
Microbiol Res ; 279: 127551, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38016380

RESUMO

Agriculture in the 21st century faces grave challenges to meet the unprecedented food demand of the burgeoning population as well as reduce the ecological footprint for achieving sustainable development goals. The extensive use of harsh synthetic surfactants in pesticides and the agrochemical industry has substantial adverse impacts on the soil and environment due to their toxic and non-biodegradable nature. Biosurfactants derived from plant, animal, and microbial sources can be an eco-friendly alternative to chemical surfactants. Microbes producing biosurfactants play a noteworthy role in biofilm formation, plant pathogen elimination, biodegradation, bioremediation, improving nutrient bioavailability, and can thrive well under stressful environments. Microbial biosurfactants are well suited for heavy metal and organic contaminants remediation in agricultural soil due to their low toxicity, high activity at fluctuating temperatures, biodegradability, and stability over a wide array of environmental conditions. This green technology will improve the agricultural soil quality by increasing the soil flushing efficiency, mobilization, and solubilization of nutrients by forming metal-biosurfactant complexes, and through the dissemination of complex nutrients. Such characteristics help it to play a pivotal role in environmental sustainability in the foreseeable future, which is required to increase the viability of biosurfactants for extensive commercial uses, making them accessible, affordable, and economically sustainable.


Assuntos
Agricultura , Solo , Plantas/metabolismo , Biodegradação Ambiental , Tensoativos/metabolismo
10.
J Mol Model ; 29(12): 383, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37987928

RESUMO

CONTEXT: Dynamic metal nanoclusters have become a hot area of research in the field of nanoscience and nanotechnology due to their potential applications in micro devices. One such dynamic cluster is a quasi-planar ground state (GS) Al13+ cluster which exhibits an electric field driven up and down flipping motion of the flexible tail which oscillates with respect to the mean plane. A Car-Parrinello molecular dynamics (CPMD) simulation has been carried out to understand the nature of dynamics of the cluster. CPMD simulation study reveals that the flexible tail region of the Al13+ isomeric system (two ground states M1, M2 and a transition state TS connecting them) can be engaged in a systematic up down flipping motion by the application of a transverse electric field. A saw tooth electric field of amplitude 5.19 V/nm is sufficient to induce the up-and-down flipping oscillation of the cluster, which has an average oscillation frequency of around 20 THz. AIM, NICS and AdNDP analyses also have been carried out to understand the fluxional nature of the cluster from the electronic structural perspective. Electronic structural analysis of selected optimized intermediate states in the presence of transverse electric field has also been analyzed to correlate the electronic structure with the dynamic nature of the cluster. METHODS: Single-point energies of all intermediate states between two minima of Al13+ clusters connected through a transition state cluster. Optimized geometries of Al13+ clusters in the presence of electric field of different strengths have been carried out by using the Gaussian 03 package. 6-311 + G(d) basis set and B3LYP hybrid density functional have been utilized for these studies. To establish the flipping motion, Car-Parrinello molecular dynamics (CPMD) has been performed using the cp.x module of the Quantum ESPRESSO 6.3.0 program package using the Perdew-Burke-Ernzerhof (PBE) functional, plane-wave basis set and ultrasoft pseudopotentials. ORTEP-3 and POV ray-3.7 software packages have been used for visualization and graphics generation. Atoms in molecule (AIM), Adaptive Natural Density Partitioning (AdNDP) analysis have been carried out using Multiwfn 3.7 program package.

11.
Nat Commun ; 14(1): 5615, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37699887

RESUMO

Topologically Associating Domains (TADs) separate vertebrate genomes into insulated regulatory neighborhoods that focus genome-associated processes. TADs are formed by Cohesin-mediated loop extrusion, with many TAD boundaries consisting of clustered binding sites of the CTCF insulator protein. Here we determine how this clustering of CTCF binding contributes to the blocking of loop extrusion and the insulation between TADs. We identify enrichment of three features of CTCF binding at strong TAD boundaries, consisting of strongly bound and closely spaced CTCF binding peaks, with a further enrichment of DNA-binding motifs within these peaks. Using multi-contact Nano-C analysis in cells with normal and perturbed CTCF binding, we establish that individual CTCF binding sites contribute to the blocking of loop extrusion, but in an incomplete manner. When clustered, individual CTCF binding sites thus create a stepwise insulation between neighboring TADs. Based on these results, we propose a model whereby multiple instances of temporal loop extrusion blocking create strong insulation between TADs.


Assuntos
Sítios de Ligação , Fator de Ligação a CCCTC/genética , Análise por Conglomerados , Domínios Proteicos
12.
J Nutr ; 153(12): 3382-3396, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37660953

RESUMO

BACKGROUND: Maternal vitamin B12 deficiency plays a vital role in fetal programming, as corroborated by previous studies on murine models and longitudinal human cohorts. OBJECTIVES: This study assessed the effects of diet-induced maternal vitamin B12 deficiency on F1 offspring in terms of cardiometabolic health and normalization of these effects by maternal-periconceptional vitamin B12 supplementation. METHODS: A diet-induced maternal vitamin B12 deficient Wistar rat model was generated in which female rats were either fed a control AIN-76A diet (with 0.01 g/kg vitamin B12) or the same diet with vitamin B12 removed. Females from the vitamin B12-deficient group were mated with males on the control diet. A subset of vitamin B12-deficient females was repleted with vitamin B12 on day 1 of conception. The offspring in the F1 generation were assessed for changes in body composition, plasma biochemistry, and molecular changes in the liver. A multiomics approach was used to obtain a mechanistic insight into the changes in the offspring liver. RESULTS: We showed that a 36% reduction in plasma vitamin B12 levels during pregnancy in F0 females can lead to continued vitamin B12 deficiency (60%-70% compared with control) in the F1 offspring and program them for cardiometabolic adversities. These adversities, such as high triglycerides and low high-density lipoprotein cholesterol, were seen only among F1 males but not females. DNA methylome analysis of the liver of F1 3-mo-old offspring highlights sexual dimorphism in the alteration of methylation status of genes critical to signaling processes. Proteomics and targeted metabolomics analysis confirm that sex-specific alterations occur through modulations in PPAR signaling and steroid hormone biosynthesis pathway. Repletion of deficient mothers with vitamin B12 at conception normalizes most of the molecular and biochemical changes. CONCLUSIONS: Maternal vitamin B12 deficiency has a programming effect on the next generation and increases the risk for cardiometabolic syndrome in a sex-specific manner. Normalization of the molecular risk markers on vitamin B12 supplementation indicates a causal role.


Assuntos
Doenças Cardiovasculares , Deficiência de Vitamina B 12 , Gravidez , Masculino , Humanos , Ratos , Animais , Feminino , Camundongos , Ratos Wistar , Deficiência de Vitamina B 12/metabolismo , Vitamina B 12 , Reprodução , Doenças Cardiovasculares/etiologia
13.
Mater Horiz ; 10(11): 4952-4959, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37609955

RESUMO

Induction heating has been applied for a variety of purposes over the years, including hyperthermia-induced cell death, industrial manufacturing, and heterogeneous catalysis. However, its potential in materials synthesis has not been extensively studied. Herein, we have demonstrated magnetic induction heating-assisted synthesis of core-shell nanoparticles starting from a magnetic core. The induction heating approach allows an easy synthesis of FeNi3@Mo and Fe2.2C@Mo nanoparticles containing a significantly higher amount of molybdenum on the surface than similar materials synthesized using conventional heating. Exhaustive electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy characterization data are presented to establish the core-shell structures. Furthermore, the molybdenum shell was transformed into the Mo2C phase, and the catalytic activity of the resulting nanoparticles tested for the propane dry reforming reaction under induction heating. Lastly, the beneficial role of induction heating-mediated synthesis was extended toward the preparation of the FeNi3@WOx core-shell nanoparticles.

14.
Nat Commun ; 14(1): 4216, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452051

RESUMO

Malaria parasite lacks canonical pathways for amino acid biosynthesis and depends primarily on hemoglobin degradation and extracellular resources for amino acids. Interestingly, a putative gene for glutamine synthetase (GS) is retained despite glutamine being an abundant amino acid in human and mosquito hosts. Here we show Plasmodium GS has evolved as a unique type I enzyme with distinct structural and regulatory properties to adapt to the asexual niche. Methionine sulfoximine (MSO) and phosphinothricin (PPT) inhibit parasite GS activity. GS is localized to the parasite cytosol and abundantly expressed in all the life cycle stages. Parasite GS displays species-specific requirement in Plasmodium falciparum (Pf) having asparagine-rich proteome. Targeting PfGS affects asparagine levels and inhibits protein synthesis through eIF2α phosphorylation leading to parasite death. Exposure of artemisinin-resistant Pf parasites to MSO and PPT inhibits the emergence of viable parasites upon artemisinin treatment.


Assuntos
Artemisininas , Parasitos , Animais , Humanos , Glutamato-Amônia Ligase/genética , Glutamato-Amônia Ligase/metabolismo , Asparagina/genética , Aminoácidos , Glutamina/metabolismo , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Artemisininas/farmacologia , Parasitos/genética , Parasitos/metabolismo
15.
bioRxiv ; 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37293114

RESUMO

Macrophages and dendritic cells have long been appreciated for their ability to migrate to and engulf dying cells and debris, including some of the billions of cells that are naturally eliminated from our body daily. However, a substantial number of these dying cells are cleared by 'non-professional phagocytes', local epithelial cells that are critical to organismal fitness. How non-professional phagocytes sense and digest nearby apoptotic corpses while still performing their normal tissue functions is unclear. Here, we explore the molecular mechanisms underlying their multifunctionality. Exploiting the cyclical bouts of tissue regeneration and degeneration during the hair cycle, we show that stem cells can transiently become non-professional phagocytes when confronted with dying cells. Adoption of this phagocytic state requires both local lipids produced by apoptotic corpses to activate RXRα, and tissue-specific retinoids for RARγ activation. This dual factor dependency enables tight regulation of the genes requisite to activate phagocytic apoptotic clearance. The tunable phagocytic program we describe here offers an effective mechanism to offset phagocytic duties against the primary stem cell function of replenishing differentiated cells to preserve tissue integrity during homeostasis. Our findings have broad implications for other non-motile stem or progenitor cells which experience cell death in an immune-privileged niche.

16.
Arthrosc Sports Med Rehabil ; 5(3): e827-e832, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37388895

RESUMO

Purpose: To identify posterior cruciate ligament (PCL) peel-off lesions, to separate these lesions from more common midsubstance tears, and to evaluate patient outcomes after primary open repair. Methods: Patients with acute femoral-side "peel off"-type lesions associated with multiligamentous injuries who underwent PCL repair were identified. Patients with chronic PCL injuries, midsubstance PCL tears, or PCL tibial avulsions were excluded from the study. A total of 11 patients were included in this study. All patients underwent open repair using a suture pullout technique. Results: The mean follow-up period was 18 months. The mean Lysholm score at 12 months was 87. Mean knee range of motion (flexion) achieved at 12 months was 121°. No patient had grade 3 laxity on posterior stress testing at final follow-up. Conclusions: Our study showed good outcomes after primary repair of femoral PCL peel-off lesions. Level of Evidence: Level IV, therapeutic case series.

17.
Nanomaterials (Basel) ; 13(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37177019

RESUMO

In the present paper, we compare the activity, selectivity, and stability of a supported nickel catalyst in classical heating conditions and in magnetically activated catalysis by using iron wool as a heating agent. The catalyst, 5 wt% Ni supported on titania (Degussa P25), was prepared via an organometallic decomposition method and was thoroughly characterized by using elemental, microscopic, and diffraction techniques. In the event of magnetic induction heating, the % CO2 conversion reached a maximum of ~85% compared to ~78% for thermal conditions at a slightly lower temperature (~335 °C) than the thermal heating (380 °C). More importantly, both processes were found to be stable for 45 h on stream. Moreover, the effects of magnetic induction and classical heating over the catalyst evolution were discussed. This study demonstrated the potential of magnetic heating-mediated methanation, which is currently under investigation for the development of pilot-scale reactors.

18.
Immunity ; 56(6): 1255-1268.e5, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37059107

RESUMO

In early life, susceptibility to invasive infection skews toward a small subset of microbes, whereas other pathogens associated with diseases later in life, including Streptococcus pneumoniae (Spn), are uncommon among neonates. To delineate mechanisms behind age-dependent susceptibility, we compared age-specific mouse models of invasive Spn infection. We show enhanced CD11b-dependent opsonophagocytosis by neonatal neutrophils improved protection against Spn during early life. The augmented function of neonatal neutrophils was mediated by higher CD11b surface expression at the population level due to dampened efferocytosis, which also resulted in more CD11bhi "aged" neutrophils in peripheral blood. Dampened efferocytosis during early life could be attributed to the lack of CD169+ macrophages in neonates and reduced systemic expressions of multiple efferocytic mediators, including MerTK. On experimentally impairing efferocytosis later in life, CD11bhi neutrophils increased and protection against Spn improved. Our findings reveal how age-dependent differences in efferocytosis determine infection outcome through the modulation of CD11b-driven opsonophagocytosis and immunity.


Assuntos
Neutrófilos , Fagocitose , Camundongos , Animais , Humanos , Macrófagos/metabolismo , Streptococcus pneumoniae , c-Mer Tirosina Quinase
19.
medRxiv ; 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36865305

RESUMO

Alzheimer's disease, the most common age-related neurodegenerative disease, is closely associated with both amyloid-ß plaque and neuroinflammation. Two thirds of Alzheimer's disease patients are females and they have a higher disease risk. Moreover, women with Alzheimer's disease have more extensive brain histological changes than men along with more severe cognitive symptoms and neurodegeneration. To identify how sex difference induces structural brain changes, we performed unbiased massively parallel single nucleus RNA sequencing on Alzheimer's disease and control brains focusing on the middle temporal gyrus, a brain region strongly affected by the disease but not previously studied with these methods. We identified a subpopulation of selectively vulnerable layer 2/3 excitatory neurons that that were RORB-negative and CDH9-expressing. This vulnerability differs from that reported for other brain regions, but there was no detectable difference between male and female patterns in middle temporal gyrus samples. Disease-associated, but sex-independent, reactive astrocyte signatures were also present. In clear contrast, the microglia signatures of diseased brains differed between males and females. Combining single cell transcriptomic data with results from genome-wide association studies (GWAS), we identified MERTK genetic variation as a risk factor for Alzheimer's disease selectively in females. Taken together, our single cell dataset revealed a unique cellular-level view of sex-specific transcriptional changes in Alzheimer's disease, illuminating GWAS identification of sex-specific Alzheimer's risk genes. These data serve as a rich resource for interrogation of the molecular and cellular basis of Alzheimer's disease.

20.
Microbiol Spectr ; : e0494322, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36976018

RESUMO

The food vacuole plays a central role in the blood stage of parasite development by digesting host hemoglobin acquired from red blood cells and detoxifying the host heme released during hemoglobin digestion into hemozoin. Blood-stage parasites undergo periodic schizont bursts, releasing food vacuoles containing hemozoin. Clinical studies in malaria-infected patients and in vivo animal studies have shown the association of hemozoin with disease pathogenesis and abnormal host immune responses in malaria. Here, we perform a detailed in vivo characterization of putative Plasmodium berghei amino acid transporter 1 localized in the food vacuole to understand its significance in the malaria parasite. We show that the targeted deletion of amino acid transporter 1 in Plasmodium berghei leads to a swollen food vacuole phenotype with the accumulation of host hemoglobin-derived peptides. Plasmodium berghei amino acid transporter 1-knockout parasites produce less hemozoin, and the hemozoin crystals display a thin morphology compared with wild-type parasites. The knockout parasites show reduced sensitivity to chloroquine and amodiaquine by showing recrudescence. More importantly, mice infected with the knockout parasites are protected from cerebral malaria and display reduced neuronal inflammation and cerebral complications. Genetic complementation of the knockout parasites restores the food vacuole morphology with hemozoin levels similar to that of wild-type parasites, causing cerebral malaria in the infected mice. The knockout parasites also show a significant delay in male gametocyte exflagellation. Our findings highlight the significance of amino acid transporter 1 in food vacuole functionality and its association with malaria pathogenesis and gametocyte development. IMPORTANCE Food vacuoles of the malaria parasite are involved in the degradation of red blood cell hemoglobin. The amino acids derived from hemoglobin degradation support parasite growth, and the heme released is detoxified into hemozoin. Antimalarials such as quinolines target hemozoin formation in the food vacuole. Food vacuole transporters transport hemoglobin-derived amino acids and peptides from the food vacuole to the parasite cytosol. Such transporters are also associated with drug resistance. Here, we show that the deletion of amino acid transporter 1 in Plasmodium berghei leads to swollen food vacuoles with the accumulation of hemoglobin-derived peptides. The transporter-deleted parasites generate less hemozoin with thin crystal morphology and show reduced sensitivity to quinolines. Mice infected with transporter-deleted parasites are protected from cerebral malaria. There is also a delay in male gametocyte exflagellation, affecting transmission. Our findings uncover the functional significance of amino acid transporter 1 in the life cycle of the malaria parasite.

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