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1.
PLoS Biol ; 22(7): e3002706, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950066

RESUMO

Episodic memory is essential to navigate in a changing environment by recalling past events, creating new memories, and updating stored information from experience. Although the mechanisms for acquisition and consolidation have been profoundly studied, much less is known about memory retrieval. Hippocampal spatial representations are key for retrieval of contextually guided episodic memories. Indeed, hippocampal place cells exhibit stable location-specific activity which is thought to support contextual memory, but can also undergo remapping in response to environmental changes. It is unclear if remapping is directly related to the expression of different episodic memories. Here, using an incidental memory recognition task in rats, we showed that retrieval of a contextually guided memory is reflected by the levels of CA3 remapping, demonstrating a clear link between external cues, hippocampal remapping, and episodic memory retrieval that guides behavior. Furthermore, we describe NMDARs as key players in regulating the balance between retrieval and memory differentiation processes by controlling the reactivation of specific memory traces. While an increase in CA3 NMDAR activity boosts memory retrieval, dentate gyrus NMDAR activity enhances memory differentiation. Our results contribute to understanding how the hippocampal circuit sustains a flexible balance between memory formation and retrieval depending on the environmental cues and the internal representations of the individual. They also provide new insights into the molecular mechanisms underlying the contributions of hippocampal subregions to generate this balance.

2.
BMC Genomics ; 25(1): 104, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38262955

RESUMO

INTRODUCTION: White Striping (WS) and Wooden Breast (WB) pectoral myopathies are relevant disorders for contemporary broiler production worldwide. Several studies aimed to elucidate the genetic components associated with the occurrence of these myopathies. However, epigenetic factors that trigger or differentiate these two conditions are still unclear. The aim of this study was to identify miRNAs differentially expressed (DE) between normal and WS and WB-affected broilers, and to verify the possible role of these miRNAs in metabolic pathways related to the manifestation of these pectoral myopathies in 28-day-old broilers. RESULTS: Five miRNAs were DE in the WS vs control (gga-miR-375, gga-miR-200b-3p, gga-miR-429-3p, gga-miR-1769-5p, gga-miR-200a-3p), 82 between WB vs control and 62 between WB vs WS. Several known miRNAs were associated with WB, such as gga-miR-155, gga-miR-146b, gga-miR-222, gga-miR-146-5p, gga-miR- 29, gga-miR-21-5p, gga-miR-133a-3p and gga-miR-133b. Most of them had not previously been associated with the development of this myopathy in broilers. We also have predicted 17 new miRNAs expressed in the broilers pectoral muscle. DE miRNA target gene ontology analysis enriched 6 common pathways for WS and WB compared to control: autophagy, insulin signaling, FoxO signaling, endocytosis, and metabolic pathways. The WS vs control contrast had two unique pathways, ERBB signaling and the mTOR signaling, while WB vs control had 14 unique pathways, with ubiquitin-mediated proteolysis and endoplasmic reticulum protein processing being the most significant. CONCLUSIONS: We found miRNAs DE between normal broilers and those affected with breast myopathies at 28 days of age. Our results also provide novel evidence of the miRNAs role on the regulation of WS and in the differentiation of both WS and WB myopathies. Overall, our study provides insights into miRNA-mediated and pathways involved in the occurrence of WS and WB helping to better understand these chicken growth disorders in an early age. These findings can help developing new approaches to reduce these complex issues in poultry production possibly by adjustments in nutrition and management conditions. Moreover, the miRNAs and target genes associated with the initial stages of WS and WB development could be potential biomarkers to be used in selection to reduce the occurrence of these myopathies in broiler production.


Assuntos
MicroRNAs , Doenças Musculares , Animais , Galinhas , Perfilação da Expressão Gênica , Transcriptoma
3.
Curr Issues Mol Biol ; 46(5): 3763-3793, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38785503

RESUMO

This study explores a nanoemulsion formulated with açaí seed oil, known for its rich fatty acid composition and diverse biological activities. This study aimed to characterise a nanoemulsion formulated with açaí seed oil and explore its cytotoxic effects on HeLa and SiHa cervical cancer cell lines, alongside assessing its antioxidant and toxicity properties both in vitro and in vivo. Extracted from fruits sourced in Brazil, the oil underwent thorough chemical characterization using gas chromatography-mass spectrometry. The resulting nanoemulsion was prepared and evaluated for stability, particle size, and antioxidant properties. The nanoemulsion exhibited translucency, fluidity, and stability post centrifugation and temperature tests, with a droplet size of 238.37, PDI -9.59, pH 7, and turbidity 0.267. In vitro assessments on cervical cancer cell lines revealed antitumour effects, including inhibition of cell proliferation, migration, and colony formation. Toxicity tests conducted in cell cultures and female Swiss mice demonstrated no adverse effects of both açaí seed oil and nanoemulsion. Overall, açaí seed oil, particularly when formulated into a nanoemulsion, presents potential for cancer treatment due to its bioactive properties and safety profile.

4.
Mol Cell Biochem ; 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38310174

RESUMO

Angiotensin-converting enzyme (ACE) is a key component of the renin-angiotensin system and plays an important role in homeostasis and maintenance of blood pressure. However, little is known about allele and genotypic frequencies, as well as phenotypic characteristics associated with ACE polymorphism genotypes in South American populations. This study aimed to verify the allelic predominance and genotype frequency of ACE I/D polymorphism in South America and its association with the main diseases and related conditions. We conducted a systematic review considering studies published in the last 25 years available in PubMed, Scielo, LILACS, LIPECS, Coleciona SUS, CUMED, BINACIS, IBECS, and MEDLINE databases, resulting in the inclusion of 121 studies. Quality of the studies was assessed according to the Strengthening the Reporting of Genetic Association (STREGA) guidelines. We mapped the frequency of the ACE I/D polymorphism in South American populations. 8,856 (32.1%) subjects were DD, 13,050 were ID (47.4%), and 5,644 were II (20.5%) carriers. The main associated conditions included systemic arterial hypertension and other cardiovascular conditions, cardiorespiratory or respiratory characteristics, physical activity level, kidney conditions, aging-related diseases, as well as different types of cancers and metabolic conditions. 61.1% of the studies found no significant association between the respective conditions investigated and the ACE I/D polymorphism. Considering DD genotype or D allele, 21.5% of the studies observed negative and 4.9% positive outcomes. Regarding ID genotype, 4.1% of the studies identified negative and 0.8% positive outcomes, and for II genotype or I allele, 4.1% of the results had negative and 10.7% positive associations.

5.
Eur J Appl Physiol ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613678

RESUMO

BACKGROUND: Walking/run promotes greater post-exercise hypotension (PEH) than resistance exercise (RE) which can be associated nitric oxide production. Then, we investigated if adding walking between RE increases PEH. METHODS: Thirteen hypertensive women (48 ± 1.9 years; 26.8 ± 0.3 kg/m2) performed five experimental sessions: 1-traditional RE with passive interval (PIBS); 2-RE with active interval between sets (AIBS); 3-RE with active interval between exercises (AIEX); 4-aerobic exercise (AE); 5-no exercise. Blood pressure was measured before and immediately after exercise and every 10 min of a 60-min post-exercise recovery period. Plasma nitrite (NO) and malondialdehyde (MDA) were also measured. RESULTS: AIBS, AIEX, and AE sessions promoted systolic PEH (12 ± 1.53; 16 ± 2.13; 18 ± 1.34 mmHg, respectively) and diastolic PEH (8 ± 1.38; 8 ± 0.79; 8 ± 0.58 mmHg). In AIBS, AIEX and AE sessions, significant PEH was noted at 10 or 20 min; in PIBS, PEH was significant only at 40 min. In the PIBS session, NO did not change, but presented higher values after AIBS, AIEX and AE sessions. MDA showed no changes between sessions. CONCLUSIONS: Passive or active intervals in resistance exercise promote PEH in hypertensive women. Active intervals shorten the PEH onset time as additional benefit.

6.
Parasitol Res ; 123(1): 88, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38190005

RESUMO

Trypanosoma evansi is a widespread and neglected zoonotic parasite that affects domestic and wild animals, causing a disease commonly known as "surra." The Brazilian Pantanal wetland is recognized as an enzootic area for this protozoan, yet recognizing the importance of reservoir hosts also in order to prevent zoonotic outbreaks. This study aimed to assess the occurrence of T. evansi in jaguars (Panthera onca) from the Brazilian Pantanal wetland and explore associated clinical and hematological manifestations. A total of 42 animals were screened by PCR and sequenced for species identification when positive. Trypanosoma evansi was detected in six free-ranging jaguars (six positive animals of 42 captures and 16 recaptures), representing the first molecular evidence of such infection in this animal species. Our findings suggest that jaguars may act as reservoir hosts of T. evansi in the Brazilian Pantanal wetland. The better understanding of the role of wildlife in the epidemiology of T. evansi is also of importance to future reintroduction and translocation programs toward wildlife conservation efforts.


Assuntos
Panthera , Trypanosoma , Animais , Brasil/epidemiologia , Áreas Alagadas , Trypanosoma/genética , Animais Selvagens
7.
Parasitol Res ; 123(4): 195, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38658460

RESUMO

Among the species described within the Onchocercidae family, Dirofilaria immitis is regarded as the most common worldwide, causing severe and often fatal conditions in dogs, cats, and occasionally humans. Dirofilaria spp. are vectored by mosquitoes, simulids, and culicoids, with their epidemiology dependent on the geographical distribution of competent vectors. Eight species of Dirofilaria have been reported so far in Brazil, of which six parasitize non-human primates, deer, procyonids, and marsupials. Here, we investigated the occurrence of Onchocercidae in wild felids (i.e., Panthera onca, Puma concolor, Herpailurus yagouaroundi, Leopardus geoffroyi, Leopardus guttulus, Leopardus pardalis, Leopardus wiedii, Leopardus munoai) from different locations in Brazil. Overall, 82 samples (n = 63 blood; n = 19 tissues) were molecularly screened for cytochrome c oxidase subunit-1 (cox1) gene. Four (i.e., 4.8%) wild felid samples were positive, and at BLAST analysis, the obtained sequences showed varying percentage of nucleotide identity with the genera Brugia (i.e., 87-88%), Setaria (i.e., 89%), and D. immitis (i.e., 94.4%). Phylogenetic analyses clustered sequences obtained into three distinct clades, one with D. immitis and the remaining two with other Onchocercidae spp. Data herein obtained highlight the need for a more comprehensive understanding of the diversity and biology of Onchocercidae in South America in order to assess the potential impact that these species may have for domestic and wild animals, as well as humans.


Assuntos
Dirofilaria immitis , Dirofilariose , Felidae , Animais , Brasil/epidemiologia , Felidae/parasitologia , Dirofilariose/parasitologia , Dirofilariose/epidemiologia , Dirofilaria immitis/genética , Dirofilaria immitis/isolamento & purificação , Dirofilaria immitis/classificação , Filogenia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Animais Selvagens/parasitologia , Análise de Sequência de DNA , DNA de Helmintos/genética , Dados de Sequência Molecular
8.
J Appl Clin Med Phys ; 25(5): e14361, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38642406

RESUMO

PURPOSES: This study aimed to develop and validate algorithms for automating intensity modulated radiation therapy (IMRT) planning in breast cancer patients, with a focus on patient anatomical characteristics. MATERIAL AND METHODS: We retrospectively selected 400 breast cancer patients without lymph node involvement for automated treatment planning. Automation was achieved using the Eclipse Scripting Application Programming Interface (ESAPI) integrated into the Eclipse Treatment Planning System. We employed three beam insertion geometries and three optimization strategies, resulting in 3600 plans, each delivering a 40.05 Gy dose in 15 fractions. Gantry angles in the tangent fields were selected based on a criterion involving the minimum intersection area between the Planning Target Volume (PTV) and the ipsilateral lung in the Beam's Eye View projection. ESAPI was also used to gather patient anatomical data, serving as input for Random Forest models to select the optimal plan. The Random Forest classification considered both beam insertion geometry and optimization strategy. Dosimetric data were evaluated in accordance with the Radiation Therapy Oncology Group (RTOG) 1005 protocol. RESULTS: Overall, all approaches generated high-quality plans, with approximately 94% meeting the acceptable dose criteria for organs at risk and/or target coverage as defined by RTOG guidelines. Average automated plan generation time ranged from 6 min and 37 s to 9 min and 22 s, with the mean time increasing with additional fields. The Random Forest approach did not successfully enable automatic planning strategy selection. Instead, our automated planning system allows users to choose from the tested geometry and strategy options. CONCLUSIONS: Although our attempt to correlate patient anatomical features with planning strategy using machine learning tools was unsuccessful, the resulting dosimetric outcomes proved satisfactory. Our algorithm consistently produced high-quality plans, offering significant time and efficiency advantages.


Assuntos
Algoritmos , Neoplasias da Mama , Órgãos em Risco , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Humanos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Feminino , Neoplasias da Mama/radioterapia , Órgãos em Risco/efeitos da radiação , Estudos Retrospectivos , Automação , Prognóstico
9.
Nurs Crit Care ; 29(2): 347-356, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37264262

RESUMO

BACKGROUND: Critically ill patients are more vulnerable to medical adhesive-related skin injuries (MARSI), whose prevention is a constant challenge and one of the main quality indicators of nursing care. MARSI associated with indwelling urinary catheter (IUC) fixation is a relevant adverse event, mainly because of the constant involuntary traction and high skin vulnerability of the fixation site. Silicone adhesive tape has appreciable qualities for fragile skin among the range of adhesives, leading to the inference that it reduces the risk of MARSI. AIM: To compare silicone adhesive tape for IUC fixation with acrylate tape regarding its safety and efficacy. STUDY DESIGN: This was a randomized controlled trial blinded to the patients and evaluator. Data were collected from an intensive care unit (ICU) of a tertiary university hospital in Brazil. Patients with IUC and no MARSI at the fixation site were considered eligible. The omega (Ω) fixation technique was used for IUC fixation. A total of 132 participants were enrolled and divided into two research groups: 66 patients in the intervention group (silicone tape) and 66 in the control group (acrylate tape). Outcomes were the incidence of MARSI, patient outcome in the ICU and hospital and partial, total and overall spontaneous detachment of the tapes. RESULTS: The overall incidence of MARSI was 28%, with 21% in the silicone group and 35% in the acrylate group, with no statistically significant difference (p = .121), including the severity of the lesions (p = .902). However, partial (p = .003) and overall (p < .001) detachment of the tapes were more frequent in the silicone group. CONCLUSIONS: Silicone tape is no safer than acrylate tape for IUC fixation and is less adhesively effective. RELEVANCE TO CLINICAL PRACTICE: There is no evidence to support the extensive use of silicone tape in this context.


Assuntos
Cateteres de Demora , Cateteres Urinários , Humanos , Cateteres de Demora/efeitos adversos , Cateterismo Urinário , Adesivos/efeitos adversos , Cuidados Críticos , Hospitais Universitários , Silicones , Acrilatos
10.
J Vasc Bras ; 23: e20230077, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38562125

RESUMO

Background: Arterialization of the dorsal venous arch of the foot is a technique indicated in cases of critical lower limb ischemia that do not have a distal bed that is adequate to enable conventional treatment such as revascularization, angioplasty, or clinical treatment. Objectives: The purpose of this study is to present the result of arterialization of the venous arch of the foot in 16 patients who underwent treatment with this technique. Methods: This is a cross-sectional retrospective descriptive analytical study based on a review of the medical records of 16 patients who underwent arterialization of the dorsal venous arch of the foot for limb salvage from January 2016 to January 2021. Results: Four (25%) of the 16 patients who underwent arterialization of the venous arch of the foot underwent a major amputation during the same hospital stay and one patient (6.25%) had a major amputation within 6 months. The other 11 patients (68.75%) had their limbs preserved, with 10 undergoing minor amputations (toes and forefoot) and one patient having no additional procedures. Conclusions: We conclude that the technique of arterialization of the dorsal venous arch of the foot should be considered in selected cases. It is a valid alternative for limb salvage when conventional treatment is impossible.

11.
J Vasc Bras ; 23: e20230087, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38803655

RESUMO

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

12.
Emerg Infect Dis ; 29(4): 843-845, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36958036

RESUMO

Thelazia callipaeda is a zoonotic vector-borne nematode that infects and causes eye disease among a wide range of domestic and wild mammals, including humans. We describe an unusual case of reinfection by this nematode in Serbia and call for a focus on preventive measures in endemic areas.


Assuntos
Doenças do Cão , Oftalmopatias , Infecções por Spirurida , Thelazioidea , Animais , Humanos , Cães , Reinfecção , Infecções por Spirurida/epidemiologia , Infecções por Spirurida/prevenção & controle , Infecções por Spirurida/veterinária , Sérvia , Doenças do Cão/epidemiologia , Mamíferos
13.
Emerg Infect Dis ; 29(8): 1559-1565, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37486185

RESUMO

On Linosa Island, Italy, Dirofilaria immitis infection has been hyperendemic in dogs and seroprevalent among islanders. In 2020, we implemented a heartworm disease elimination program on Linosa Island. Of 54 dogs tested for D. immitis antigen and microfilariae, 28 had positive results and received treatment with oral doxycycline twice daily for 4 weeks plus topical imidacloprid/moxidectin monthly for 12 months. The 26 dogs with negative results received monthly topical imidacloprid/moxidectin as preventive. During month 1, the number of microfilaremic dogs was reduced by 76.5%. From month 2 on, all animals were microfilariae negative, and during months 3 to 9, the number of antigen-positive dogs decreased progressively. Treatment of positive dogs coupled with chemoprophylaxis for noninfected dogs was effective, protecting them from new infections. The elimination program reduced the risk for human infection, representing a One Health paradigm. Monitoring and chemoprophylaxis are advocated to maintain the status of heartworm disease-free area.


Assuntos
Dirofilaria immitis , Dirofilariose , Doenças do Cão , Animais , Cães , Dirofilariose/tratamento farmacológico , Dirofilariose/epidemiologia , Dirofilariose/prevenção & controle , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Quimioterapia Combinada , Itália/epidemiologia , Microfilárias
14.
Microb Pathog ; 180: 106164, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37211264

RESUMO

Candida haemulonii is an emergent infectious pathogen that affects human presenting comorbidities and/or immunodepression. Little is known about other possible hosts. For the first time, this fungus was found causing a cutaneous infection in a snake, Boa constrictor, characterized by scale opacity and several ulcerative lesions. This C. haemulonii was isolated, identified using molecular techniques and a phylogenetic study, and had its growth totally inhibited by all the drugs tested; however, no fungicide effect was seen for fluconazole and itraconazole. The B. constrictor clinical signals subsided after a treatment using a biogenic silver nanoparticle-based ointment. These findings, along with the B. constrictor presence near human habitats, warn for the necessity of wildlife health monitoring for emergent and opportunistic diseases in peri-urban environments.


Assuntos
Boidae , Candidíase , Nanopartículas Metálicas , Animais , Humanos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida , Filogenia , Candidíase/microbiologia , Prata/farmacologia , Fluconazol/farmacologia , Fluconazol/uso terapêutico , Testes de Sensibilidade Microbiana
15.
Chem Res Toxicol ; 36(4): 570-582, 2023 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-35537067

RESUMO

The emergence and re-emergence of bacterial strains resistant to multiple drugs represent a global health threat, and the search for novel biological targets is a worldwide concern. AhpC are enzymes involved in bacterial redox homeostasis by metabolizing diverse kinds of hydroperoxides. In pathogenic bacteria, AhpC are related to several functions, as some isoforms are characterized as virulence factors. However, no inhibitor has been systematically evaluated to date. Here we show that the natural ent-kaurane Adenanthin (Adn) efficiently inhibits AhpC and molecular interactions were explored by computer assisted simulations. Additionally, Adn interferes with growth and potentializes the effect of antibiotics (kanamycin and PMBN), positioning Adn as a promising compound to treat infections caused by multiresistant bacterial strains.


Assuntos
Diterpenos do Tipo Caurano , Peroxirredoxinas , Antibacterianos/farmacologia , Diterpenos do Tipo Caurano/farmacologia , Canamicina , Bactérias
16.
Virol J ; 20(1): 181, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37587490

RESUMO

BACKGROUND: Influenza A virus (IAV) is endemic in pigs globally and co-circulation of genetically and antigenically diverse virus lineages of subtypes H1N1, H1N2 and H3N2 is a challenge for the development of effective vaccines. Virosomes are virus-like particles that mimic virus infection and have proven to be a successful vaccine platform against several animal and human viruses. METHODS: This study evaluated the immunogenicity of a virosome-based influenza vaccine containing the surface glycoproteins of H1N1 pandemic, H1N2 and H3N2 in pigs. RESULTS: A robust humoral and cellular immune response was induced against the three IAV subtypes in pigs after two vaccine doses. The influenza virosome vaccine elicited hemagglutinin-specific antibodies and virus-neutralizing activity. Furthermore, it induced a significant maturation of macrophages, and proliferation of B lymphocytes, effector and central memory CD4+ and CD8+ T cells, and CD8+ T lymphocytes producing interferon-γ. Also, the vaccine demonstrated potential to confer long-lasting immunity until the market age of pigs and proved to be safe and non-cytotoxic to pigs. CONCLUSIONS: This virosome platform allows flexibility to adjust the vaccine content to reflect the diversity of circulating IAVs in swine in Brazil. The vaccination of pigs may reduce the impact of the disease on swine production and the risk of swine-to-human transmission.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Vacinas contra Influenza , Influenza Humana , Humanos , Animais , Suínos , Vacinas Combinadas , Imunidade Humoral , Linfócitos T CD8-Positivos , Vírus da Influenza A Subtipo H3N2 , Virossomos
17.
Biomacromolecules ; 24(3): 1258-1266, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36788678

RESUMO

Tissue engineering offers attractive strategies to develop three-dimensional scaffolds mimicking the complex hierarchical structure of the native bone. The bone is formed by cells incorporated in a molecularly organized extracellular matrix made of an inorganic phase, called biological apatite, and an organic phase mainly made of collagen and noncollagenous macromolecules. Although many strategies have been developed to replicate the complexity of bone at the nanoscale in vitro, a critical challenge has been to control the orchestrated process of mineralization promoted by bone cells in vivo and replicate the anatomical and biological properties of native bone. In this study, we used type I collagen to fabricate mineralized scaffolds mimicking the microenvironment of the native bone. The sulfated polysaccharide κ-carrageenan was added to the scaffolds to fulfill the role of noncollagenous macromolecules in the organization and mineralization of the bone matrix and cell adhesion. Scanning electron microscopy images of the surface of the collagen/κ-carrageenan scaffolds showed the presence of a dense and uniform network of intertwined fibrils, while images of the scaffolds' lateral sides showed the presence of collagen fibrils with a parallel alignment, which is characteristic of dense connective tissues. MC3T3-E1 osteoblasts were cultured in the collagen scaffolds and were viable after up to 7 days of culture, both in the absence and in the presence of κ-carrageenan. The presence of κ-carrageenan in the collagen scaffolds stimulated the maturation of the cells to a mineralizing phenotype, as suggested by the increased expression of key genes related to bone mineralization, including alkaline phosphatase (Alp), bone sialoprotein (Bsp), osteocalcin (Oc), and osteopontin (Opn), as well as the ability to mineralize the extracellular matrix after 14 and 21 days of culture. Taken together, the results described in this study shed light on the potential use of collagen/κ-carrageenan scaffolds to study the role of the structural organization of bone-mimetic synthetic matrices in cell function.


Assuntos
Biomimética , Calcificação Fisiológica , Carragenina , Colágeno/química , Engenharia Tecidual/métodos , Osteoblastos , Alicerces Teciduais/química
18.
Eur Biophys J ; 52(8): 721-733, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37938350

RESUMO

Matrix vesicles are a special class of extracellular vesicles thought to actively contribute to both physiologic and pathologic mineralization. Proteomic studies have shown that matrix vesicles possess high amounts of annexin A5, suggesting that the protein might have multiple roles at the sites of calcification. Currently, Annexin A5 is thought to promote the nucleation of apatitic minerals close to the inner leaflet of the matrix vesicles' membrane enriched in phosphatidylserine and Ca2+. Herein, we aimed at unravelling a possible additional role of annexin A5 by investigating the ability of annexin A5 to adsorb on matrix-vesicle biomimetic liposomes and Langmuir monolayers made of dipalmitoylphosphatidylserine (DPPS) and dipalmitoylphosphatidylcholine (DPPC) in the absence and in the presence of Ca2+. Differential scanning calorimetry and dynamic light scattering measurements showed that Ca2+ at concentrations in the 0.5-2.0 mM range induced the aggregation of liposomes probably due to the formation of DPPS-enriched domains. However, annexin A5 avoided the aggregation of liposomes at Ca2+ concentrations lower than 1.0 mM. Surface pressure versus surface area isotherms showed that the adsorption of annexin A5 on the monolayers made of a mixture of DPPC and DPPS led to a reduction in the area of excess compared to the theoretical values, which confirmed that the protein favored attractive interactions among the membrane lipids. The stabilization of the lipid membranes by annexin A5 was also validated by recording the changes with time of the surface pressure. Finally, fluorescence microscopy images of lipid monolayers revealed the formation of spherical lipid-condensed domains that became unshaped and larger in the presence of annexin A5. Our data support the model that annexin A5 in matrix vesicles is recruited at the membrane sites enriched in phosphatidylserine and Ca2+ not only to contribute to the intraluminal mineral formation but also to stabilize the vesicles' membrane and prevent its premature rupture.


Assuntos
Anexinas , Lipossomos , Anexina A5/química , Anexina A5/metabolismo , Fosfatidilserinas/química , Fosfatidilserinas/metabolismo , Biomimética , Proteômica , Cálcio/metabolismo
19.
Lett Appl Microbiol ; 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142415

RESUMO

The excess of minerals in the industrial substrates is detrimental for Saccharomyces cerevisiae ethanol fermentation performance. In this work, we sought to understand the effect of some of those minerals on the physiology of Dekkera bruxellensis. Three groups of minerals were classified on the basis of the aerobic growth profiles on glucose: neutrals (K+, Mg2+, P5+ and Zn2+), inducers (Mn2+ and Ca2+) and inhibitors (Al3+, Cu2+ and Fe2+). Cu2+ showed the highest mineral toxicity, and its effect was dependent of the level of medium aeration. On the other hand, copper stimulated respiration by increasing growth on respiratory carbon sources. Most growth inhibitors also hampered glucose fermentation, with changes in carbon distribution to metabolic routes dedicated to anabolic reactions and for alternative reduced co-factors oxidations to maintain cellular homeostasis. The negative effect of Cu2+ on yeast fermentation was partially alleviated by Mg2+ and Mn2+, similar to magnesium antagonism observed for S. cerevisiae. All these results might contribute to understand the action of these minerals in sugarcane substrates on the physiology of D. bruxellensis cells. Therefore, it represents one more step for the consolidation of the industrial use of this yeast in the production of fuel-ethanol as well as other biotechnological goods.

20.
Parasitol Res ; 122(12): 2951-2956, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37823992

RESUMO

Nematode species of the genus Dracunculus (Spirurida: Dracunculoidea) infect tissues and body cavities of reptiles, domestic and wild carnivores, and humans. The definitive hosts acquire the infection by ingesting intermediate (i.e., cyclopoid copepod) or paratenic (i.e., amphibians and fishes) hosts. Here we report the jaguar (Panthera onca) as a potential new host for Dracunculus sp. The nematode was collected from an ulcerated cutaneous nodule on the left anterior limb of a female jaguar in the municipality of Miranda, Mato Grosso do Sul state, Brazil. Based on the morphology of first stage larvae collected from a small fragment of the uterus of the adult nematode, the species was identified as Dracunculus sp. Reichard, 1759. Additionally, the morphological identification was molecularly confirmed by sequencing the cox1 gene. This report advocates for further investigations into the transmission cycle of this parasite in the Brazilian Pantanal wetland, considering the role of wildlife hosts and the zoonotic potential of Dracunculus species in that area.


Assuntos
Dracunculoidea , Panthera , Animais , Humanos , Feminino , Animais Selvagens , Dracunculus , Peixes , Brasil
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