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1.
Cell ; 187(13): 3165-3186, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38906093

RESUMO

Patterned morphologies, such as segments, spirals, stripes, and spots, frequently emerge during embryogenesis through self-organized coordination between cells. Yet, complex patterns also emerge in adults, suggesting that the capacity for spontaneous self-organization is a ubiquitous property of biological tissues. We review current knowledge on the principles and mechanisms of self-organized patterning in embryonic tissues and explore how these principles and mechanisms apply to adult tissues that exhibit features of patterning. We discuss how and why spontaneous pattern generation is integral to homeostasis and healing of tissues, illustrating it with examples from regenerative biology. We examine how aberrant self-organization underlies diverse pathological states, including inflammatory skin disorders and tumors. Lastly, we posit that based on such blueprints, targeted engineering of pattern-driving molecular circuits can be leveraged for synthetic biology and the generation of organoids with intricate patterns.


Assuntos
Padronização Corporal , Animais , Humanos , Desenvolvimento Embrionário , Homeostase , Organoides/metabolismo , Envelhecimento
2.
Nature ; 618(7966): 808-817, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37344645

RESUMO

Niche signals maintain stem cells in a prolonged quiescence or transiently activate them for proper regeneration1. Altering balanced niche signalling can lead to regenerative disorders. Melanocytic skin nevi in human often display excessive hair growth, suggesting hair stem cell hyperactivity. Here, using genetic mouse models of nevi2,3, we show that dermal clusters of senescent melanocytes drive epithelial hair stem cells to exit quiescence and change their transcriptome and composition, potently enhancing hair renewal. Nevus melanocytes activate a distinct secretome, enriched for signalling factors. Osteopontin, the leading nevus signalling factor, is both necessary and sufficient to induce hair growth. Injection of osteopontin or its genetic overexpression is sufficient to induce robust hair growth in mice, whereas germline and conditional deletions of either osteopontin or CD44, its cognate receptor on epithelial hair cells, rescue enhanced hair growth induced by dermal nevus melanocytes. Osteopontin is overexpressed in human hairy nevi, and it stimulates new growth of human hair follicles. Although broad accumulation of senescent cells, such as upon ageing or genotoxic stress, is detrimental for the regenerative capacity of tissue4, we show that signalling by senescent cell clusters can potently enhance the activity of adjacent intact stem cells and stimulate tissue renewal. This finding identifies senescent cells and their secretome as an attractive therapeutic target in regenerative disorders.


Assuntos
Cabelo , Melanócitos , Transdução de Sinais , Animais , Camundongos , Cabelo/citologia , Cabelo/crescimento & desenvolvimento , Folículo Piloso/citologia , Folículo Piloso/fisiologia , Receptores de Hialuronatos/metabolismo , Melanócitos/citologia , Melanócitos/metabolismo , Nevo/metabolismo , Nevo/patologia , Osteopontina/metabolismo , Células-Tronco/citologia
3.
CA Cancer J Clin ; 68(1): 64-89, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29165798

RESUMO

Mounting evidence suggests that weight management and physical activity (PA) improve overall health and well being, and reduce the risk of morbidity and mortality among cancer survivors. Although many opportunities exist to include weight management and PA in routine cancer care, several barriers remain. This review summarizes key topics addressed in a recent National Academies of Science, Engineering, and Medicine workshop entitled, "Incorporating Weight Management and Physical Activity Throughout the Cancer Care Continuum." Discussions related to body weight and PA among cancer survivors included: 1) current knowledge and gaps related to health outcomes; 2) effective intervention approaches; 3) addressing the needs of diverse populations of cancer survivors; 4) opportunities and challenges of workforce, care coordination, and technologies for program implementation; 5) models of care; and 6) program coverage. While more discoveries are still needed for the provision of optimal weight-management and PA programs for cancer survivors, obesity and inactivity currently jeopardize their overall health and quality of life. Actionable future directions are presented for research; practice and policy changes required to assure the availability of effective, affordable, and feasible weight management; and PA services for all cancer survivors as a part of their routine cancer care. CA Cancer J Clin 2018;68:64-89. © 2017 American Cancer Society.


Assuntos
Exercício Físico , Neoplasias/terapia , Obesidade/terapia , Assistência ao Paciente/métodos , Programas de Redução de Peso , Peso Corporal , Sobreviventes de Câncer , Continuidade da Assistência ao Paciente , Humanos , Neoplasias/complicações , Obesidade/complicações , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
4.
J Immunol ; 210(4): 389-397, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36637221

RESUMO

Signal inhibitory receptor on leukocytes-1 (SIRL-1) is an immune inhibitory receptor expressed on human granulocytes and monocytes that dampens antimicrobial functions. We previously showed that sputum neutrophils from infants with severe respiratory syncytial virus (RSV) bronchiolitis have decreased SIRL-1 surface expression compared with blood neutrophils and that SIRL-1 surface expression is rapidly lost from in vitro activated neutrophils. This led us to hypothesize that activated neutrophils lose SIRL-1 by ectodomain shedding. Here, we developed an ELISA and measured the concentration of soluble SIRL-1 (sSIRL-1) in patients with RSV bronchiolitis and hospitalized patients with COVID-19, which are both characterized by neutrophilic inflammation. In line with our hypothesis, sSIRL-1 concentration was increased in sputum compared with plasma of patients with RSV bronchiolitis and in serum of hospitalized patients with COVID-19 compared with control serum. In addition, we show that in vitro activated neutrophils release sSIRL-1 by proteolytic cleavage and that this diminishes the ability to inhibit neutrophilic reactive oxygen species production via SIRL-1. Finally, we found that SIRL-1 shedding is prevented by proteinase 3 inhibition and by extracellular adherence protein from Staphylococcus aureus. Notably, we recently showed that SIRL-1 is activated by PSMα3 from S. aureus, suggesting that S. aureus may counteract SIRL-1 shedding to benefit from preserved inhibitory function of SIRL-1. In conclusion, we report that SIRL-1 is released from activated neutrophils by proteinase 3 cleavage and that endogenous sSIRL-1 protein is present in vivo.


Assuntos
Bronquiolite , COVID-19 , Infecções por Vírus Respiratório Sincicial , Humanos , Lactente , Bronquiolite/metabolismo , COVID-19/metabolismo , Mieloblastina , Neutrófilos , Receptores Imunológicos , Staphylococcus aureus , Leucócitos/metabolismo
5.
J Neurosci ; 43(13): 2222-2241, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36868853

RESUMO

Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed treatment for individuals experiencing major depressive disorder. The therapeutic mechanisms that take place before, during, or after SSRIs bind the serotonin transporter (SERT) are poorly understood, partially because no studies exist on the cellular and subcellular pharmacokinetic properties of SSRIs in living cells. We studied escitalopram and fluoxetine using new intensity-based, drug-sensing fluorescent reporters targeted to the plasma membrane, cytoplasm, or endoplasmic reticulum (ER) of cultured neurons and mammalian cell lines. We also used chemical detection of drug within cells and phospholipid membranes. The drugs attain equilibrium in neuronal cytoplasm and ER at approximately the same concentration as the externally applied solution, with time constants of a few s (escitalopram) or 200-300 s (fluoxetine). Simultaneously, the drugs accumulate within lipid membranes by ≥18-fold (escitalopram) or 180-fold (fluoxetine), and possibly by much larger factors. Both drugs leave cytoplasm, lumen, and membranes just as quickly during washout. We synthesized membrane-impermeant quaternary amine derivatives of the two SSRIs. The quaternary derivatives are substantially excluded from membrane, cytoplasm, and ER for >2.4 h. They inhibit SERT transport-associated currents sixfold or 11-fold less potently than the SSRIs (escitalopram or fluoxetine derivative, respectively), providing useful probes for distinguishing compartmentalized SSRI effects. Although our measurements are orders of magnitude faster than the therapeutic lag of SSRIs, these data suggest that SSRI-SERT interactions within organelles or membranes may play roles during either the therapeutic effects or the antidepressant discontinuation syndrome.SIGNIFICANCE STATEMENT Selective serotonin reuptake inhibitors stabilize mood in several disorders. In general, these drugs bind to SERT, which clears serotonin from CNS and peripheral tissues. SERT ligands are effective and relatively safe; primary care practitioners often prescribe them. However, they have several side effects and require 2-6 weeks of continuous administration until they act effectively. How they work remains perplexing, contrasting with earlier assumptions that the therapeutic mechanism involves SERT inhibition followed by increased extracellular serotonin levels. This study establishes that two SERT ligands, fluoxetine and escitalopram, enter neurons within minutes, while simultaneously accumulating in many membranes. Such knowledge will motivate future research, hopefully revealing where and how SERT ligands engage their therapeutic target(s).


Assuntos
Transtorno Depressivo Maior , Inibidores Seletivos de Recaptação de Serotonina , Animais , Humanos , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Fluoxetina/farmacologia , Escitalopram , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Retículo Endoplasmático/metabolismo , Citalopram/farmacologia , Mamíferos
6.
Clin Endocrinol (Oxf) ; 100(3): 251-259, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38127470

RESUMO

CONTEXT: Although sleep disordered breathing (SDB) is well-recognised in acromegaly, most studies have reported heterogeneous, often heavily treated, groups and few have performed detailed sleep phenotyping at presentation. OBJECTIVE: To study SDB using the gold standard of polysomnography, in the largest group of newly-diagnosed, treatment-naïve patients with acromegaly. SETTING AND PATIENTS: 40 patients [22 males, 18 females; mean age 54 years (range 23-78)], were studied to: (i) establish the prevalence and severity of SDB (ii) assess the reliability of commonly employed screening tools [Epworth Sleepiness Scale (ESS) and overnight oxygen desaturation index (DI)] to detect SDB (iii) determine the extent to which sleep architecture is disrupted. RESULTS: Obstructive sleep apnoea (OSA), defined by the apnoea-hypopnoea index (AHI), was present in 79% of subjects (mild, n = 12; moderate, n = 5; severe, n = 14). However, in these individuals with OSA by AHI criteria, ESS (positive in 35% [n = 11]) and DI (positive in 71%: mild, n = 11; moderate, n = 6; severe, n = 5) markedly underestimated its prevalence/extent. Seventy-eight percent of patients exhibited increased arousal, with marked disruption of the sleep cycle, despite most (82%) having normal total time asleep. Fourteen patients spent longer in stage 1 sleep. Deeper sleep stages were severely attenuated in many subjects (reduced stage 2, n = 18; reduced slow wave sleep, n = 24; reduced rapid eye movement sleep, n = 32). CONCLUSION: Our study provides strong support for clinical guidelines that recommend screening for sleep apnoea syndrome in patients with newly-diagnosed acromegaly. Importantly, however, it highlights shortcomings in commonly recommended screening tools (questionnaires, desaturation index) and demonstrates the added value of polysomnography to allow timely detection of obstructive sleep apnoea and associated sleep cycle disruption.


Assuntos
Acromegalia , Apneia Obstrutiva do Sono , Masculino , Feminino , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Transversais , Prevalência , Estudos Prospectivos , Acromegalia/diagnóstico , Acromegalia/epidemiologia , Reprodutibilidade dos Testes , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/epidemiologia , Sono
7.
Nucleic Acids Res ; 50(1): 350-367, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34928380

RESUMO

Although the RNA helicase Upf1 has hitherto been examined mostly in relation to its cytoplasmic role in nonsense mediated mRNA decay (NMD), here we report high-throughput ChIP data indicating genome-wide association of Upf1 with active genes in Schizosaccharomyces pombe. This association is RNase sensitive, correlates with Pol II transcription and mRNA expression levels. Changes in Pol II occupancy were detected in a Upf1 deficient (upf1Δ) strain, prevalently at genes showing a high Upf1 relative to Pol II association in wild-type. Additionally, an increased Ser2 Pol II signal was detected at all highly transcribed genes examined by ChIP-qPCR. Furthermore, upf1Δ cells are hypersensitive to the transcription elongation inhibitor 6-azauracil. A significant proportion of the genes associated with Upf1 in wild-type conditions are also mis-regulated in upf1Δ. These data envisage that by operating on the nascent transcript, Upf1 might influence Pol II phosphorylation and transcription.


Assuntos
RNA Helicases/metabolismo , RNA Polimerase II/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Fosforilação , RNA Helicases/genética , RNA Polimerase II/genética , Schizosaccharomyces , Proteínas de Schizosaccharomyces pombe/genética , Ativação Transcricional
8.
Int J Mol Sci ; 25(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673786

RESUMO

Antimicrobial peptides (AMPs) are viewed as potential compounds for the treatment of bacterial infections. Nevertheless, the successful translation of AMPs into clinical applications has been impeded primarily due to their low stability in biological environments and potential toxicological concerns at higher concentrations. The covalent attachment of AMPs to a material's surface has been sought to improve their stability. However, it is still an open question what is required to best perform such an attachment and the role of the support. In this work, six different AMPs were covalently attached to a long-ranged ordered amphiphilic hydrogel, with their antibacterial efficacy evaluated and compared to their performance when free in solution. Among the tested AMPs were four different versions of synthetic end-tagged AMPs where the sequence was altered to change the cationic residue as well as to vary the degree of hydrophobicity. Two previously well-studied AMPs, Piscidin 1 and Omiganan, were also included as comparisons. The antibacterial efficacy against Staphylococcus aureus remained largely consistent between free AMPs and those attached to surfaces. However, the activity pattern against Pseudomonas aeruginosa on hydrogel surfaces displayed a marked contrast to that observed in the solution. Additionally, all the AMPs showed varying degrees of hemolytic activity when in solution. This activity was entirely diminished, and all the AMPs were non-hemolytic when attached to the hydrogels.


Assuntos
Antibacterianos , Hemólise , Hidrogéis , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Staphylococcus aureus , Hidrogéis/química , Hidrogéis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Hemólise/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Humanos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Interações Hidrofóbicas e Hidrofílicas , Eritrócitos/efeitos dos fármacos
9.
Aesthet Surg J ; 44(6): 605-611, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38290053

RESUMO

BACKGROUND: Bacterial contamination of implants has been linked to biofilm formation and subsequent infection, capsular contracture, and breast implant-associated anaplastic large cell lymphoma. Reducing contamination during implant insertion should therefore reduce biofilm formation disease sequelae. OBJECTIVES: The aim of this study was to compare levels of contamination between preventative techniques. METHODS: A model to simulate the passage of implants through a skin incision was designed that utilized a sterile textured polyvinyl plastic sheet contaminated with Staphylococcus epidermidis. In the first stage of the polyvinyl contamination model, implants were subject to infection-mitigation techniques and passed through the incision, then placed onto horse blood agar plates and incubated for 24 hours. In the second stage of the study the same contamination was applied to human abdominal wall specimens. A 5 cm incision was made through skin and fat, then implants were passed through and levels of contamination were measured as described. RESULTS: Smooth implants grew a mean of 95 colony-forming units (CFUs; approximately 1 CFU/cm2) and textured implants grew 86 CFUs (also approximately 1 CFU/cm2). CFU counts were analyzed by the Mann-Whitney U-test which showed no significant difference between implant types (P < .05); independent-sample t-tests showed a significant difference. The dependent-variable techniques were then compared as groups by one-way analysis of variance, which also showed a significant reduction compared with the control group (P < .01). CONCLUSIONS: This in vitro study has shown the effectiveness of antiseptic rinse and skin/implant barrier techniques for reducing bacterial contamination of breast implants at the time of insertion.


Assuntos
Biofilmes , Implante Mamário , Implantes de Mama , Infecções Relacionadas à Prótese , Staphylococcus epidermidis , Implantes de Mama/microbiologia , Implantes de Mama/efeitos adversos , Humanos , Staphylococcus epidermidis/isolamento & purificação , Implante Mamário/efeitos adversos , Implante Mamário/instrumentação , Infecções Relacionadas à Prótese/prevenção & controle , Infecções Relacionadas à Prótese/microbiologia , Feminino , Contaminação de Equipamentos/prevenção & controle , Contagem de Colônia Microbiana
10.
BMC Bioinformatics ; 24(1): 358, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37740175

RESUMO

BACKGROUND: Helicobacter pylori is a prominent causative agent of gastric ulceration, gastric adenocarcinoma and gastric lymphoma and have been categorised as a group 1 carcinogen by WHO. The treatment of H. pylori with proton pump inhibitors and antibiotics is effective but also leads to increased antibiotic resistance, patient dissatisfaction, and chances of reinfection. Therefore, an effective vaccine remains the most suitable prophylactic option for mass administration against this infection. RESULTS: We modelled a multi-chimera subunit vaccine candidate against H. pylori by screening its secretory/outer membrane proteins. We identified B-cell, MHC-II and IFN-γ-inducing epitopes within these proteins. The population coverage, antigenicity, physiochemical properties and secondary structure were evaluated using different in-silico tools, which showed it can be a good and effective vaccine candidate. The 3-D construct was predicted, refined, validated and docked with TLRs. Finally, we performed the molecular docking/simulation and immune simulation studies to validate the stability of interaction and in-silico cloned the epitope sequences into a pET28b(+) plasmid vector. CONCLUSION: The multiepitope-constructed vaccine contains T- cells, B-cells along with IFN-γ inducing epitopes that have the property to generate good cell-mediated immunity and humoral response. This vaccine can protect most of the world's population. The docking study and immune simulation revealed a good binding with TLRs and cell-mediated and humoral immune responses, respectively. Overall, we attempted to design a multiepitope vaccine and expect this vaccine will show an encouraging result against H. pylori infection in in-vivo use.


Assuntos
Adenocarcinoma , Helicobacter pylori , Vacinas , Humanos , Epitopos , Simulação de Acoplamento Molecular
11.
J Biol Chem ; 298(9): 102285, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35870554

RESUMO

Secretagogin (SCGN) is a three-domain hexa-EF-hand Ca2+-binding protein that plays a regulatory role in the release of several hormones. SCGN is expressed largely in pancreatic ß-cells, certain parts of the brain, and also in neuroendocrine tissues. The expression of SCGN is altered in several diseases, such as diabetes, cancers, and neurodegenerative disorders; however, the precise associations that closely link SCGN expression to such pathophysiologies are not known. In this work, we report that SCGN is an early responder to cellular stress, and SCGN expression is temporally upregulated by oxidative stress and heat shock. We show the overexpression of SCGN efficiently prevents cells from heat shock and oxidative damage. We further demonstrate that in the presence of Ca2+, SCGN efficiently prevents the aggregation of a broad range of model proteins in vitro. Small-angle X-ray scattering (BioSAXS) studies further reveal that Ca2+ induces the conversion of a closed compact apo-SCGN conformation into an open extended holo-SCGN conformation via multistate intermediates, consistent with the augmentation of chaperone activity of SCGN. Furthermore, isothermal titration calorimetry establishes that Ca2+ enables SCGN to bind α-synuclein and insulin, two target proteins of SCGN. Altogether, our data not only demonstrate that SCGN is a Ca2+-dependent generic molecular chaperone involved in protein homeostasis with broad substrate specificity but also elucidate the origin of its altered expression in several cancers. We describe a plausible mechanism of how perturbations in Ca2+ homeostasis and/or deregulated SCGN expression would hasten the process of protein misfolding, which is a feature of many aggregation-based proteinopathies.


Assuntos
Cálcio , Motivos EF Hand , Resposta ao Choque Térmico , Células Secretoras de Insulina , Chaperonas Moleculares , Estresse Oxidativo , Agregação Patológica de Proteínas , Deficiências na Proteostase , Secretagoginas , Animais , Cálcio/metabolismo , Células HEK293 , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Agregação Patológica de Proteínas/metabolismo , Dobramento de Proteína , Deficiências na Proteostase/genética , Deficiências na Proteostase/metabolismo , Ratos , Secretagoginas/química , Secretagoginas/genética , Secretagoginas/metabolismo , alfa-Sinucleína/metabolismo
12.
J Biol Chem ; 298(2): 101539, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34958799

RESUMO

Copper (Cu) is essential for all life forms; however, in excess, it becomes toxic. Toxic properties of Cu are known to be utilized by host species against various pathogenic invasions. Leishmania, in both free-living and intracellular forms, exhibits appreciable tolerance toward Cu stress. While determining the mechanism of Cu-stress evasion employed by Leishmania, we identified and characterized a hitherto unknown Cu-ATPase in Leishmania major and established its role in parasite survival in host macrophages. This novel L. major Cu-ATPase, LmATP7, exhibits homology with its orthologs at multiple motifs. In promastigotes, LmATP7 primarily localized at the plasma membrane. We also show that LmATP7 exhibits Cu-dependent expression patterns and complements Cu transport in a Cu-ATPase-deficient yeast strain. Promastigotes overexpressing LmATP7 exhibited higher survival upon Cu stress, indicating efficacious Cu export compared with Wt and heterozygous LmATP7 knockout parasites. We further explored macrophage-Leishmania interactions with respect to Cu stress. We found that Leishmania infection triggers upregulation of major mammalian Cu exporter, ATP7A, in macrophages, and trafficking of ATP7A from the trans-Golgi network to endolysosomes in macrophages harboring amastigotes. Simultaneously, in Leishmania, we observed a multifold increase in LmATP7 transcripts as the promastigote becomes established in macrophages and morphs to the amastigote form. Finally, overexpressing LmATP7 in parasites increases amastigote survivability within macrophages, whereas knocking it down reduces survivability drastically. Mice injected in their footpads with an LmATP7-overexpressing strain showed significantly larger lesions and higher amastigote loads as compared with controls and knockouts. These data establish the role of LmATP7 in parasite infectivity and intramacrophagic survivability.


Assuntos
Cobre , Leishmania major , Leishmaniose , ATPases do Tipo-P , Animais , Cobre/metabolismo , Leishmania major/enzimologia , Leishmaniose/metabolismo , Leishmaniose/parasitologia , Mamíferos , Camundongos , ATPases do Tipo-P/metabolismo
13.
Proteins ; 91(4): 567-580, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36456186

RESUMO

The glutathione degrading enzyme ChaC1 is highly upregulated in several cancers and viral infections making it a potential pharmacological target for cancer therapy. As an enzyme, however, ChaC1 has a relatively high Km (~2 mM) towards its natural substrate, and therefore finding its inhibitors becomes very difficult. Given this limitation, a careful mapping of the active site has become necessary. In the current study, the enzyme-substrate complex was generated by docking glutathione with the modeled hChaC1 structure. Using a combination of in silico and wet lab approaches, the active site residues forming direct interactions with the substrate glutathione were identified and validated. Furthermore, the role of residues exclusively conserved in the ChaC family and forming the surface of the active site were also explored for their putative role in active site stabilization. Mutants of these residues have been analysed for their structural stability and interaction with the substrate through MD simulations and MMGBSA binding energy calculations. These findings were experimentally validated by assessment of their function through in vivo assays in yeast. The experimental evidences along with the molecular modeling suggest that residues 38'YGSL'41, D68, R72, E115, and Y143 are responsible for high affinity binding of hChaC1 with the substrate/inhibitor, whereas the residues exclusive to the ChaC family are required for the structural stability of the enzyme and its active site. Such a characterization of essential active site and conserved residues is significant as a key step toward rational design of novel inhibitors of the ChaC1 enzyme.


Assuntos
Glutationa , Saccharomyces cerevisiae , Domínio Catalítico , Modelos Moleculares , Saccharomyces cerevisiae/metabolismo , Glutationa/metabolismo
14.
J Cell Biochem ; 124(10): 1587-1602, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37697970

RESUMO

Metacestode, the larva of Taenia solium, is the causative agent for neurocysticercosis (NCC), which causes epilepsy. The unavailability of a vaccine against human NCC is a major cause for its widespread prevalence across the globe. Therefore, the development of a reliable vaccine against NCC is the need of the hour. Employing a combination of proteomics and immunoinformatics, we endeavored to formulate a vaccine candidate. The immune reactive cyst fluid antigens of T. solium were identified by immune-blotting two-dimensional gels with NCC patient's sera, followed by Matrix-assisted laser desorption-ionization analysis. We performed a detailed proteomic study of these immune reactive proteins by utilizing immune-informatics tools, identified the nontoxic, nonallergic, B-cell epitopes, and collected epitopes with the least sequence homology with human and other Taenia species. These epitopes were joined through linkers to construct a multiepitope vaccine. Different physiochemical parameters such as molecular weight (23.82 kDa), instability (39.91), and aliphatic index (49.61) were calculated to ensure the stability of the linked peptides vaccine. The vaccine demonstrated stable interactions with different immune receptors like Toll-like receptor 4 and IgG confirming that it will effectively stimulate the host immune response. We anticipate that our designed B-cell linear epitope-based vaccine will show promising results in in vitro and in vivo assays. This study provides a platform that would be useful to develop other suitable vaccine candidates to prevent helminthic neglected tropical diseases in near future.

15.
Cell Immunol ; 391-392: 104758, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37651886

RESUMO

The anti-inflammatory role of the programmed death-1 receptor (PD-1) is well appreciated. However, the mechanism of how PD-1 signaling inhibits the pro-inflammatory cytokine responses in macrophages, which is further exploited by Leishmania to foster their intracellular survival, was unknown. We found that among three major MAP kinases regulating immune activation, PD-1 signaling decreased only JNK phosphorylation without perturbing p38 and ERK. Inflammatory transcription factor STAT1 was also inhibited by PD-1. Association studies documented that SHP, the downstream phosphatase of PD-1, is directly responsible for the decreased phosphorylation of JNK and STAT1. JNK and STAT1 deactivation led to Elk-1/c-Fos inhibition, which significantly decreased IL-12 and TNF-α levels. Further investigation revealed c-Fos deactivation ultimately rendered transcription factor AP1 inactive and facilitating parasite-favorable anti-inflammatory environment.


Assuntos
Leishmania , Receptor de Morte Celular Programada 1 , Linhagem Celular , Macrófagos , Fosforilação , Fatores de Transcrição/metabolismo , Anti-Inflamatórios , Proteínas Quinases JNK Ativadas por Mitógeno , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Ann Neurol ; 92(3): 349-357, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35713213

RESUMO

OBJECTIVE: Intravenous thrombolysis (IVT) with tenecteplase has been associated with better clinical outcomes in acute ischemic stroke (AIS) patients with confirmed large vessel occlusions compared to IVT with alteplase. However, the utility of tenecteplase for the treatment of all AIS patients eligible for IVT has not been established. METHODS: We compared the safety and efficacy of tenecteplase versus alteplase in AIS patients by analyzing propensity score matched data from 20 centers participating in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register. Patients receiving IVT with tenecteplase were matched with up to 3 patients receiving alteplase from the same center. The primary outcome of interest was the distribution of 3-month functional outcomes. Secondary outcomes included the rates of patients with symptomatic intracranial hemorrhage (SICH) in the first 24 hours, excellent (modified Rankin Scale [mRS] score = 0-1) or good (mRS score = 0-2) functional outcome, and all-cause mortality at 3 months. RESULTS: A total of 331 tenecteplase-treated AIS patients were matched to 797 patients treated with alteplase (median age = 70 years, 43.9% women, median National Institutes of Health Stroke Scale score = 11, interquartile range = 6-17). Patients treated with tenecteplase had better 3-month functional outcomes (common odds ratio [OR] = 1.54, 95% confidence interval [CI] = 1.18-2.00) with higher odds of good functional outcome (OR = 2.00, 95% CI = 1.45-2.77) and a lower likelihood of all-cause mortality (OR = 0.43, 95% CI = 0.27-0.67) at 3 months, compared to alteplase-treated patients. No difference was found in the likelihood of the 3-month excellent functional outcomes (OR = 1.31, 95% CI = 0.96-1.78) and 24-hour SICH (1.0% vs 1.3%, OR = 0.72, 95% CI = 0.20-2.64). INTERPRETATION: IVT with tenecteplase was associated with better 3-month clinical outcomes compared to IVT with alteplase in AIS patients, with no increased risk of symptomatic intracranial bleeding. ANN NEUROL 2022;92:349-357.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Idoso , Isquemia Encefálica/tratamento farmacológico , Feminino , Fibrinolíticos , Humanos , Hemorragias Intracranianas/induzido quimicamente , Masculino , Acidente Vascular Cerebral/tratamento farmacológico , Tenecteplase/uso terapêutico , Terapia Trombolítica , Ativador de Plasminogênio Tecidual , Resultado do Tratamento
17.
Transfusion ; 63 Suppl 3: S120-S125, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37072924

RESUMO

BACKGROUND: Platelets stored at room temperature (22-24°C) for transfusion purposes have a shelf life of 5-7 days, or 72 h when stored refrigerated (1-6°C). The limited shelf life of platelet products severely compromises platelet inventory. We hypothesized that cold storage of platelets in 100% plasma using xenon gas under high pressure would extend shelf life to 14 days. STUDY DESIGN AND METHODS: Double apheresis platelet units were collected and split equally between two bags. One unit was placed in a hyperbaric chamber, pressurized to 4 bars with a xenon/oxygen gas mixture, and placed in a refrigerator for 14 days (Xe). The remaining unit was aliquoted into mini-bags (10 ml) for storage at room temperature (RTP) or in cold (CSP). Samples were assayed on days 5 (RTP) or 14 (Xe and CSP) for count, metabolism, clot strength, platelet aggregation, and activation markers. RESULTS: The platelet count in Xe samples was lower than that of RTP but significantly higher than CSP. Despite similar levels of glucose and lactate, the pH of Xe samples was significantly lower than CSP. Glycoprotein expression was better preserved by Xe storage compared to CSP, but no differences in activation were observed. Thromboelastography and aggregometry results were comparable between all groups. DISCUSSION: Cold storage of platelets in plasma with hyperbaric xenon provides no significant improvement in platelet function over cold storage alone. The use of a hyperbaric chamber and the slow off-gassing of Xe-stored units complicate platelet storage and delivery logistics.


Assuntos
Plaquetas , Preservação de Sangue , Humanos , Preservação de Sangue/métodos , Plaquetas/metabolismo , Criopreservação/métodos , Temperatura Baixa , Agregação Plaquetária
18.
AJR Am J Roentgenol ; 221(1): 7-16, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36629307

RESUMO

Despite significant advances in health care, many patients from medically under-served populations are impacted by existing health care disparities. Radiologists are uniquely positioned to decrease health disparities and advance health equity efforts in their practices. However, literature on practical tools for advancing radiology health equity efforts applicable to a wide variety of patient populations and care settings is lacking. Therefore, this article seeks to equip radiologists with an evidence-based and practical knowledge tool kit of health equity strategies, presented in terms of four pillars of research, clinical care, education, and innovation. For each pillar, equity efforts across diverse patient populations and radiology practice settings are examined through the lens of existing barriers, current best practices, and future directions, incorporating practical examples relevant to a spectrum of patient populations. Health equity efforts provide an opportune window to transform radiology through personalized care delivery that is responsive to diverse patient needs. Guided by compassion and empathy as core principles of health equity, the four pillars provide a helpful framework to advance health equity efforts as a step toward social justice in health.


Assuntos
Equidade em Saúde , Radiologia , Humanos , Disparidades em Assistência à Saúde , Justiça Social
19.
AJR Am J Roentgenol ; 221(6): 711-719, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37255040

RESUMO

Patient-centered care (PCC) and equity are two of the six core domains of quality health care, according to the Institute of Medicine. Exceptional imaging care requires radiology practices to provide patient-centered (i.e., respectful and responsive to individual patient preferences, needs, and values) and equitable (i.e., does not vary in quality on the basis of gender, ethnicity, geographic location, or socioeconomic status) care. Specific barriers that prevent the delivery of patient-centered equitable care include information gaps, breaches of trust, organizational medical culture, and financial incentives. Information gaps limit practitioners in understanding the lived experience of patients. Breaches of trust prevent patients from seeking needed medical care. Organizational medical cultures may not be centered around patient experiences. Financial incentives can impede practitioners' ability to spend the time and resources required to meet patient goals and needs. Intentional approaches that integrate core principles in both PCC and health equity are required to deliver high-quality patient-centered imaging care for diverse patient populations. The purpose of this AJR Expert Panel Narrative Review is to review the origins of the PCC movement in radiology, characterize connections between the PCC and health equity movements, and describe concrete examples of ways to foster patient-centered equitable care in radiology.


Assuntos
Assistência Centrada no Paciente , Radiologia , Humanos , Assistência Centrada no Paciente/métodos , Qualidade da Assistência à Saúde
20.
Chem Rev ; 121(13): 7638-7956, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34165284

RESUMO

Copper(I)-catalyzed 1,3-dipolar cycloaddition between organic azides and terminal alkynes, commonly known as CuAAC or click chemistry, has been identified as one of the most successful, versatile, reliable, and modular strategies for the rapid and regioselective construction of 1,4-disubstituted 1,2,3-triazoles as diversely functionalized molecules. Carbohydrates, an integral part of living cells, have several fascinating features, including their structural diversity, biocompatibility, bioavailability, hydrophilicity, and superior ADME properties with minimal toxicity, which support increased demand to explore them as versatile scaffolds for easy access to diverse glycohybrids and well-defined glycoconjugates for complete chemical, biochemical, and pharmacological investigations. This review highlights the successful development of CuAAC or click chemistry in emerging areas of glycoscience, including the synthesis of triazole appended carbohydrate-containing molecular architectures (mainly glycohybrids, glycoconjugates, glycopolymers, glycopeptides, glycoproteins, glycolipids, glycoclusters, and glycodendrimers through regioselective triazole forming modular and bio-orthogonal coupling protocols). It discusses the widespread applications of these glycoproducts as enzyme inhibitors in drug discovery and development, sensing, gelation, chelation, glycosylation, and catalysis. This review also covers the impact of click chemistry and provides future perspectives on its role in various emerging disciplines of science and technology.


Assuntos
Química Click , Cobre/química , Glicoconjugados/química , Animais , Catálise , Humanos , Triazóis/química
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