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1.
Eur J Appl Physiol ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39168899

RESUMO

PURPOSE: Ischemic pre-conditioning (IPC) offers protection against future ischemic events and may improve sports performance due to several mechanisms at local and systemic levels. This study investigates the local effects on muscle contractility in electrically induced muscle contractions, thus effectively excluding any uncontrolled change in the motor drive. METHODS: Twenty-one subjects were divided into two groups: 12 subjects in the IPC group (3 × 5/5 min right arm ischemia/reperfusion; cuff pressure 250 mmHg) and 9 subjects in the SHAM group (same treatment at 20 mmHg). The adductor pollicis was contracted by supramaximal stimulation of the ulnar nerve with single pulses, trains of stimuli (5, 8, 10 and 12 Hz, 1-s duration) and bursts (4 pulses, 25 Hz), all separated by 5-s intervals. The stimulation sequence was delivered before and 15 and 30 min after IPC/SHAM treatment. The isometric contraction force, the superficial electromyographic signal, and tissue oxygenation were continuously monitored. RESULTS: A significant force decrease in time was observed at 8, 10 (p < 0.01) and 12 Hz (p < 0.05) along with a decrease in half-relaxation time in single twitches and bursts (p = 0.01), regardless of treatment. This general time-related weakening was more marked in IPC than SHAM at 5-Hz stimulation. No effects were observed on the magnitude of the superficial electromyographic signal. CONCLUSION: Data indicate that IPC does not increase muscle force during electrically stimulated contractions, supporting the idea that IPC's ergogenic effects are not due to increased muscle contractility.

2.
J Exp Biol ; 226(11)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37288646

RESUMO

Protective responses are pivotal in aiding organismal persistence in complex, multi-stressor environments. Multiple-stressor research has traditionally focused on the deleterious effects of exposure to concurrent stressors. However, encountering one stressor can sometimes confer heightened tolerance to a second stressor, a phenomenon termed 'cross-protection'. Cross-protection has been documented in a wide diversity of taxa (spanning the bacteria, fungi, plant and animal kingdoms) and habitats (intertidal, freshwater, rainforests and polar zones) in response to many stressors (e.g. hypoxia, predation, desiccation, pathogens, crowding, salinity, food limitation). Remarkably, cross-protection benefits have also been shown among emerging, anthropogenic stressors, such as heatwaves and microplastics. In this Commentary, we discuss the mechanistic basis and adaptive significance of cross-protection, and put forth the idea that cross-protection will act as a 'pre-adaptation' to a changing world. We highlight the critical role that experimental biology has played in disentangling stressor interactions and provide advice for enhancing the ecological realism of laboratory studies. Moving forward, research will benefit from a greater focus on quantifying the longevity of cross-protection responses and the costs associated with this protective response. This approach will enable us to make robust predictions of species' responses to complex environments, without making the erroneous assumption that all stress is deleterious.


Assuntos
Adaptação Fisiológica , Plásticos , Animais , Ecossistema , Aclimatação , Água Doce
3.
J Cardiovasc Nurs ; 38(3): 299-306, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37027135

RESUMO

Background: Obstructive Sleep Apnea (OSA) is associated with an increased risk of cardiovascular events, including Acute Coronary Syndrome (ACS). There is conflicting evidence that suggests OSA has a cardioprotective effect (i.e., lower troponin), via ischemic pre-conditioning, in patients with ACS. Purpose: This study had two aims: (1) compare peak troponin between non-ST elevation (NSTE) ACS patients with and without moderate OSA identified using a Holter derived respiratory disturbance index (HDRDI); and (2) determine the frequency of transient myocardial ischemia (TMI) between NSTE-ACS patients with and without moderate HDRDI. Method: This was a secondary analysis. OSA events were identified from 12-lead ECG Holter recordings using QRSs, R-R intervals, and the myogram. Moderate OSA was defined as an HDRDI ≥15 events per/hour. TMI was defined as ≥1 millimeter of ST-segment ↑ or ↓, in ≥ 1 ECG lead, ≥ 1 minute. Results: In 110 NSTE-ACS patients, 39% (n=43) had moderate HDRDI. Peak troponin was higher in patients with moderate HDRDI (6.8 ng/ml yes vs. 10.2 ng/ml no; p=0.037). There was a trend for fewer TMI events, but there were no differences (16% yes vs. 30% no; p=0.081). Conclusions: NSTE-ACS patients with moderate HDRDI have less cardiac injury than those without moderate HDRDI measured using a novel ECG derived method. These findings corroborate prior studies suggesting a possible cardioprotective effect of OSA in ACS patients via ischemic pre-condition. There was a trend for fewer TMI events in moderate HDRDI patients, but there was no statistical difference. Future research should explore the underlying physiologic mechanisms of this finding.

4.
Int J Mol Sci ; 24(2)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36675188

RESUMO

Human bone marrow mesenchymal stem cell derived-extracellular vesicles (HBMSC-EV) are known for their regenerative and anti-inflammatory effects in animal models of myocardial ischemia. However, it is not known whether the efficacy of the EVs can be modulated by pre-conditioning of HBMSC by exposing them to either starvation or hypoxia prior to EV collection. HBMSC-EVs were isolated following normoxia starvation (NS), normoxia non-starvation (NNS), hypoxia starvation (HS), or hypoxia non-starvation (HNS) pre-conditioning. The HBMSC-EVs were characterized by nanoparticle tracking analysis, electron microscopy, Western blot, and proteomic analysis. Comparative proteomic profiling revealed that starvation pre-conditioning led to a smaller variety of proteins expressed, with the associated lesser effect of normoxia versus hypoxia pre-conditioning. In the absence of starvation, normoxia and hypoxia pre-conditioning led to disparate HBMSC-EV proteomic profiles. HNS HBMSC-EV was found to have the greatest variety of proteins overall, with 74 unique proteins, the greatest number of redox proteins, and pathway analysis suggestive of improved angiogenic properties. Future HBMSC-EV studies in the treatment of cardiovascular disease may achieve the most therapeutic benefits from hypoxia non-starved pre-conditioned HBMSC. This study was limited by the lack of functional and animal models of cardiovascular disease and transcriptomic studies.


Assuntos
Doenças Cardiovasculares , Vesículas Extracelulares , Células-Tronco Mesenquimais , Animais , Humanos , Doenças Cardiovasculares/metabolismo , Proteômica , Vesículas Extracelulares/metabolismo , Hipóxia/metabolismo , Células-Tronco Mesenquimais/metabolismo
5.
Mol Ther ; 29(7): 2335-2349, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-33647456

RESUMO

Chimeric antigen receptor (CAR) T cell therapy has led to impressive clinical responses in patients with hematological malignancies; however, its effectiveness in patients with solid tumors has been limited. While CAR T cells for the treatment of advanced prostate and pancreas cancer, including those targeting prostate stem cell antigen (PSCA), are being clinically evaluated and are anticipated to show bioactivity, their safety and the impact of the immunosuppressive tumor microenvironment (TME) have not been faithfully explored preclinically. Using a novel human PSCA knockin (hPSCA-KI) immunocompetent mouse model, we evaluated the safety and therapeutic efficacy of PSCA-CAR T cells. We demonstrated that cyclophosphamide (Cy) pre-conditioning significantly modified the immunosuppressive TME and was required to uncover the efficacy of PSCA-CAR T cells in metastatic prostate and pancreas cancer models, with no observed toxicities in normal tissues with endogenous expression of PSCA. This combination dampened the immunosuppressive TME, generated pro-inflammatory myeloid and T cell signatures in tumors, and enhanced the recruitment of antigen-presenting cells, as well as endogenous and adoptively transferred T cells, resulting in long-term anti-tumor immunity.


Assuntos
Ciclofosfamida/farmacologia , Imunoterapia Adotiva/métodos , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias Pancreáticas/terapia , Neoplasias da Próstata/terapia , Microambiente Tumoral , Animais , Antígenos de Neoplasias/genética , Apoptose , Proliferação de Células , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Agonistas Mieloablativos/farmacologia , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Mol Cell Neurosci ; 110: 103573, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33248236

RESUMO

Peripheral nerve injuries have the potential to bring about long-term disabilities in individuals. The major issue in repairing nerve injuries is the poor growth rate of axons. Although several molecules have been identified as potential candidates for improving axon growth, their potential translation into clinical practice is preliminary and largely unexplored. This necessitates identifying additional molecular candidates with superior potential to improve axon growth. Lack of a simple non-surgical screening model also poses a hurdle in rapidly screening potential candidate molecules. In this work, we developed a novel, rapid screening model for nerve regeneration therapeutics that retains a focus on adult neurons. The model involves simple incubation of sensory ganglia over a period of 24 h prior to dissociation. Surprisingly, this model features unique events that reprogram both sensory neurons and supporting glia favoring axon growth. Moreover, several associated cellular and molecular changes involved in this model partially mimic classic axotomy-induced changes in sensory ganglia. Overall, this model presents with a platform that not only allows rapid screening of drug candidates but offers opportunities in studying novel intrinsic molecular changes in both neurons and glial cells directed towards improving the pace of axon growth.


Assuntos
Descoberta de Drogas/métodos , Regeneração Nervosa , Crescimento Neuronal , Fármacos Neuroprotetores/farmacologia , Células Receptoras Sensoriais/efeitos dos fármacos , Animais , Axônios/efeitos dos fármacos , Axônios/fisiologia , Células Cultivadas , Gânglios Espinais/citologia , Masculino , Neuroglia/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Células Receptoras Sensoriais/fisiologia
7.
FASEB J ; 34(9): 12976-12990, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33411380

RESUMO

Fibrosis is driven by a misdirected cell response causing the overproduction of extracellular matrix and tissue dysfunction. Numerous pharmacological strategies have attempted to prevent fibrosis but have attained limited efficacy with some detrimental side effects. While stem cell treatments have provided more encouraging results, they have exhibited high variability and have not always improved tissue function. To enhance stem cell efficacy, we evaluated whether mechanical memory could direct cell response. We hypothesized that mechanically pre-conditioning on a soft matrix (soft priming) will delay adipose-derived stem cell (ASC) transition to a pro-fibrotic phenotype, expanding their regenerative potential, and improving healing in a complex tissue environment. Primary ASCs isolated from rat and human subcutaneous fat exhibited mechanical memory, demonstrated by a delayed cell response to stiffness following two weeks of soft priming including decreased cell area, actin coherency, and extracellular matrix production compared to cells on stiff substrates. Soft primed ASCs injected into our rat model of post-traumatic elbow contracture decreased histological evidence of anterior capsule fibrosis and increased elbow range-of-motion when evaluated by joint mechanics. These findings suggest that exploiting mechanical memory by strategically controlling the culture environment during cell expansion may improve the efficacy of stem cell-based therapies targeting fibrosis.


Assuntos
Contratura/terapia , Lesões no Cotovelo , Fibrose/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Humanos , Masculino , Ratos , Ratos Long-Evans , Cicatrização
8.
Ann Hematol ; 100(11): 2763-2771, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34357435

RESUMO

The efficacy and clinical significance of pre-conditioning intervention (PCI) before allogeneic hematopoietic cell transplantation (HCT) in patients with acute lymphoblastic leukemia (ALL) not in remission remain inconclusive. The purpose of this multicenter retrospective study was to clarify the clinical significance of PCI before HCT in patients with non-remission ALL. Patients with non-remission ALL who received HCT between 2005 and 2015 at 16 institutions were included. PCI was objectively defined and classified to three groups according to the intensity of PCI (no, intensive, or moderate). The study cohort consisted of 104 patients with a median age of 38 (range 17-68). A significant decrease of blast percentage in the peripheral blood (PB) was confirmed in both PCI groups, suggesting that PCIs were effective to stabilize the disease activity. The group with moderate PCI had higher nucleated cell count in the BM compared to the group with intensive PCI or the group without PCI. The overall survival (OS) rates of groups with intensive and no PCI showed comparable and significantly better compared to the group with moderate PCI (P = 0.009). Multivariate analysis demonstrated that the OS of moderate PCI group was significantly worse compared to that of intensive PCI group (HR = 2.43, 95% CI: 1.32-4.14, P = 0.004), while the OS of intensive PCI group was comparable to that of the group without PCI. These results suggest that the intensity of PCI rather than the response to PCI may contribute to improve the transplant outcome in patients with ALL not in remission.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Condicionamento Pré-Transplante , Adolescente , Adulto , Idoso , Aloenxertos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Dexametasona/administração & dosagem , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mitoxantrona/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Recidiva , Estudos Retrospectivos , Vincristina/administração & dosagem , Adulto Jovem
9.
Nutr Metab Cardiovasc Dis ; 31(2): 528-531, 2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-33223396

RESUMO

BACKGROUND AND AIMS: Hyperglycemia at hospital admission is a common finding in patients with STEMI. However, whether elevated acute glycemia in these patients may have a direct impact on worsening prognosis or is just a marker of a greater neurohormonal activation in response to the infarction is still unsettled. We sought to investigate the prognostic impact of hyperglycemia at hospital admission in patients undergoing primary PCI (pPCI) for STEMI, and the influence of the presence of diabetes mellitus (DM) on its prognostic impact. METHODS: and Results, We enrolled 2958 consecutive STEMI patients treated by pPCI. Hyperglycemia was defined as plasma glucose >198 mg/dL (or >11 mmol/L). Patients with hyperglycemia showed a greater risk-profile; they also experienced a higher mortality both at univariable (17.6% vs 5.2%, p < 0.001) and multivariable (HR 1.9, 95%IC 1.5-2.9, p = 0.001) analysis. However, after stratification for DM presence, hyperglycemia resulted as an independent predictor of mortality only in patients without DM (HR 2, 95%IC 1.2-3.4, p = 0.01). CONCLUSION: Hyperglycemia in the setting of myocardial infarction treated with primary PCI in an independent predictor of all-cause mortality in patients without diabetes; in patients with diabetes, its prognostic impact seems attenuated.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus/sangue , Hiperglicemia/sangue , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Idoso , Biomarcadores/sangue , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidade , Feminino , Humanos , Hiperglicemia/diagnóstico , Hiperglicemia/mortalidade , Masculino , Pessoa de Meia-Idade , Admissão do Paciente , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/mortalidade , Medição de Risco , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade , Fatores de Tempo , Resultado do Tratamento
10.
Coral Reefs ; 40(5): 1491-1503, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720373

RESUMO

Ocean warming induced by climate change is the greatest threat to the persistence of coral reefs globally. Given the current rate of ocean warming, there may not be sufficient time for natural acclimation or adaptation by corals. This urgency has led to the exploration of active management techniques aimed at enhancing thermal tolerance in corals. Here, we test the capacity for transgenerational acclimation in the reef-building coral Pocillopora acuta as a means of increasing offspring performance in warmer waters. We exposed coral colonies from a reef influenced by intermittent upwelling and constant warm-water effluent from a nuclear power plant to temperatures that matched (26 °C) or exceeded (29.5 °C) season-specific mean temperatures for three reproductive cycles; offspring were allowed to settle and grow at both temperatures. Heated colonies reproduced significantly earlier in the lunar cycle and produced fewer and smaller planulae. Recruitment was lower at the heated recruitment temperature regardless of parent treatment. Recruit survival did not differ based on parent or recruitment temperature. Recruits from heated parents were smaller and had lower maximum quantum yield (Fv/Fm), a measurement of symbiont photochemical performance. We found no direct evidence that thermal conditioning of adult P. acuta corals improves offspring performance in warmer water; however, chronic exposure of parent colonies to warmer temperatures at the source reef site may have limited transgenerational acclimation capacity. The extent to which coral response to this active management approach might vary across species and sites remains unclear and merits further investigation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00338-021-02123-9.

11.
Int J Mol Sci ; 22(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299075

RESUMO

Organisms' survival is associated with the ability to respond to natural or anthropogenic environmental stressors. Frequently, these responses involve changes in gene regulation and expression, consequently altering physiology, development, or behavior. Here, we present modifications in response to heat exposure that mimics extreme summertime field conditions of lab-cultured and field-conditioned Nematostella vectensis. Using ATAC-seq and RNA-seq data, we found that field-conditioned animals had a more concentrated reaction to short-term thermal stress, expressed as enrichment of the DNA repair mechanism pathway. By contrast, lab animals had a more diffuse reaction that involved a larger number of differentially expressed genes and enriched pathways, including amino acid metabolism. Our results demonstrate that pre-conditioning affects the ability to respond efficiently to heat exposure in terms of both chromatin accessibility and gene expression and reinforces the importance of experimentally addressing ecological questions in the field.


Assuntos
Cromatina/fisiologia , Regulação da Expressão Gênica , Temperatura Alta , Laboratórios/estatística & dados numéricos , Anêmonas-do-Mar/genética , Transcriptoma , Animais , Monitoramento Ambiental , Perfilação da Expressão Gênica , Anêmonas-do-Mar/crescimento & desenvolvimento
12.
J Exp Biol ; 223(Pt 22)2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-33077641

RESUMO

Searching for reward motivates and drives behaviour. In honey bees Apis mellifera, specialized pollen foragers are attracted to and learn odours with pollen. However, the role of pollen as a reward remains poorly understood. Unlike nectar, pollen is not ingested during collection. We hypothesized that pollen (but not nectar) foragers could learn pollen by sole antennal or tarsal stimulation. Then, we tested how pairing of pollen (either hand- or bee-collected) and a neutral odour during a pre-conditioning affects performance of both pollen and nectar foragers during the classical conditioning of the proboscis extension response. Secondly, we tested whether nectar and pollen foragers perceive the simultaneous presentation of pollen (on the tarsi) and sugar (on the antennae) as a better reinforcement than sucrose alone. Finally, we searched for differences in learning of the pollen and nectar foragers when they were prevented from ingesting the reward during the conditioning. Differences in pollen-reinforced learning correlate with division of labour between pollen and nectar foragers. Results show that pollen foragers performed better than nectar foragers during the conditioning phase after being pre-conditioned with pollen. Pollen foragers also performed better than nectar foragers in both the acquisition and extinction phases of the conditioning, when reinforced with the dual reward. Consistently, pollen foragers showed improved abilities to learn cues reinforced without sugar ingestion. We discussed that differences in how pollen and nectar foragers respond to a cue associated with pollen greatly contribute to the physiological mechanism that underlies foraging specialization in the honeybee.


Assuntos
Mel , Néctar de Plantas , Animais , Abelhas , Comportamento Alimentar , Aprendizagem , Pólen
13.
Eur Heart J ; 40(22): 1771-1777, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29982507

RESUMO

Unexpected cardiac adverse effects are the leading causes of discontinuation of clinical trials and withdrawal of drugs from the market. Since the original observations in the mid-90s, it has been well established that cardiovascular risk factors and comorbidities (such as ageing, hyperlipidaemia, and diabetes) and their medications (e.g. nitrate tolerance, adenosine triphosphate-dependent potassium inhibitor antidiabetic drugs, statins, etc.) may interfere with cardiac ischaemic tolerance and endogenous cardioprotective signalling pathways. Indeed drugs may exert unwanted effects on the diseased and treated heart that is hidden in the healthy myocardium. Hidden cardiotoxic effects may be due to (i) drug-induced enhancement of deleterious signalling due to ischaemia/reperfusion injury and/or the presence of risk factors and/or (ii) inhibition of cardioprotective survival signalling pathways, both of which may lead to ischaemia-related cell death and/or pro-arrhythmic effects. This led to a novel concept of 'hidden cardiotoxicity', defined as cardiotoxity of a drug that manifests only in the diseased heart with e.g. ischaemia/reperfusion injury and/or in the presence of its major comorbidities. Little is known on the mechanism of hidden cardiotoxocity, moreover, hidden cardiotoxicity cannot be revealed by the routinely used non-clinical cardiac safety testing methods on healthy animals or tissues. Therefore, here, we emphasize the need for development of novel cardiac safety testing platform involving combined experimental models of cardiac diseases (especially myocardial ischaemia/reperfusion and ischaemic conditioning) in the presence and absence of major cardiovascular comorbidities and/or cotreatments.


Assuntos
Cardiotoxicidade/prevenção & controle , Cardiotoxinas , Desenvolvimento de Medicamentos/normas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Segurança do Paciente , Animais , Comorbidade , Cardiopatias/induzido quimicamente , Cardiopatias/prevenção & controle , Humanos , Camundongos
14.
Int J Mol Sci ; 21(3)2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31979113

RESUMO

Mesenchymal stem cells (MSCs) are on the cusp of regenerative medicine due to their differentiation capacity, favorable culture conditions, ability to be manipulated in vitro, and strong immunomodulatory activity. Recent studies indicate that the pleiotropic effects of MSCs, especially their immunomodulatory potential, can be largely attributed to paracrine factors. Exosomes, vesicles that are 30-150 nanometers in diameter that function in cell-cell communication, are one of the key paracrine effectors. MSC-derived exosomes are enriched with therapeutic miRNAs, mRNAs, cytokines, lipids, and growth factors. Emerging evidences support the compelling possibility of using MSC-derived exosomes as a new form of therapy for treating several different kinds of disease such as heart, kidney, immune diseases, neural injuries, and neurodegenerative disease. This review provides a summary of current knowledge and discusses engineering of MSC-derived exosomes for their use in translational medicine.


Assuntos
Exossomos/fisiologia , Células-Tronco Mesenquimais/fisiologia , Animais , Humanos , Doenças Neurodegenerativas/terapia , Comunicação Parácrina/fisiologia , Medicina Regenerativa/métodos
15.
Mycorrhiza ; 29(2): 127-139, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30612193

RESUMO

The relationship between mycorrhiza functioning and composition of arbuscular mycorrhizal (AM) fungal communities is an important but experimentally still rather little explored topic. The main aim of this study was thus to link magnitude of plant benefits from AM symbiosis in different abiotic contexts with quantitative changes in AM fungal community composition. A synthetic AM fungal community inoculated to the model host plant Medicago truncatula was exposed to four different abiotic contexts, namely drought, elevated phosphorus availability, and shading, as compared to standard cultivation conditions, for two cultivation cycles. Growth and phosphorus uptake of the host plants was evaluated along with the quantitative composition of the synthetic AM fungal community. Abiotic context consistently influenced mycorrhiza functioning in terms of plant benefits, and the effects were clearly linked to the P requirement of non-inoculated control plants. In contrast, the abiotic context only had a small and transient effect on the quantitative AM fungal community composition. Our findings suggest no relationship between the degree of mutualism in AM symbiosis and the relative abundances of AM fungal species in communities in our simplified model system. The observed progressive dominance of one AM fungal species indicates an important role of different growth rates of AM fungal species for the establishment of AM fungal communities in simplified systems such as agroecosystems.


Assuntos
Medicago truncatula/microbiologia , Micobioma , Micorrizas/fisiologia , Simbiose , Secas , Fósforo/análise , Luz Solar
16.
Surg Today ; 49(6): 536-545, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30730004

RESUMO

PURPOSE: Epigallocatechin 3-gallate (EGCG), a green tea polyphenol, has been shown to have anti-oxidant and anti-inflammatory effects in vitro and in vivo. The aim of this study was to investigate the effects and mechanism of EGCG on isolated pancreatic islets as pre-conditioning for pancreatic islet transplantation. METHODS: The pancreatic islets were divided into two groups: an islet culture medium group (control) and an islet culture medium with EGCG (100 µM) group. We investigated the islet viability, Nrf2 expression, reactive oxygen species (ROS) production, and heme oxygenase-1 (HO-1) mRNA. Five hundred islet equivalents after 12 h of culture for the EGCG 100 µM and control group were transplanted under the kidney capsule of streptozotocin-induced diabetic ICR mice. RESULTS: The cell viability and insulin secretion ability in the EGCG group were preserved, and the nuclear translocation of Nrf2 was increased in the EGCG group (p < 0.01). While the HO-1 mRNA levels were also higher in the EGCG group than in the control group (p < 0.05), the ROS production was lower (p < 0.01). An in vivo functional assessment showed that the blood glucose level had decreased in the EGCG group after transplantation (p < 0.01). CONCLUSION: EGCG protects the viability and function of islets by suppressing ROS production via the Nrf2 pathway.


Assuntos
Catequina/análogos & derivados , Expressão Gênica/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/fisiologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , RNA Mensageiro/metabolismo , Animais , Glicemia , Catequina/farmacologia , Sobrevivência Celular , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Técnicas In Vitro , Secreção de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/citologia , Transplante das Ilhotas Pancreáticas , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , RNA Mensageiro/genética , Espécies Reativas de Oxigênio/metabolismo , Técnicas de Cultura de Tecidos , Condicionamento Pré-Transplante
17.
World J Microbiol Biotechnol ; 36(1): 6, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31832888

RESUMO

This study presents an anhydrobiotic engineering approach aiming at conferring a high degree of desiccation tolerance to the Gram-negative endophyte Kosakonia radicincitans. In particular, pre-conditioning of bacteria under high salinities provides a remarkable positive influence on drying survival. The endophytic bacteria accumulate exogenous hydroxyectoine > 500 µmol g-1 dry weight cells exerted by osmotic stress at 4% NaCl. Microfermentation research demonstrated that hydroxyectoine provides positive effects on reducing the lag phase duration and alleviates the dissolved oxygen consumption under high salinity conditions. Beyond the amassing of hydroxyectoine, this work provides evidence supporting the notion that hydroxyectoine can produce significant changes in the endogenous bacterial metabolome during the exponential growth phase at high-osmolarity. Metabolome changes include alterations on tricarboxylic acid cycle, novo-synthesis of specific intracellular metabolites such as mannitol, myo-inositol and trehalose, and fold changes on amino acids such as L-leucine, L-asparagine, L-serine, L-methionine and L-proline. The significant fold change of L-aspartate suggests a potential acidic proteome at high-osmolarity environments, extending the knowledge of salt-stressed bacterial endophytes. Thus, these findings place the metabolic salt stress response and the hydroxyectoine accumulation by K. radicincitans into a physiological context, paving the way into the interaction between cellular phenotype associated with salt stress tolerance and drying survival capacity of Gram-negative endophytes.


Assuntos
Diamino Aminoácidos/farmacologia , Endófitos/fisiologia , Enterobacteriaceae/fisiologia , Tolerância ao Sal/fisiologia , Dessecação , Fermentação , Metaboloma , Concentração Osmolar , Pressão Osmótica , Salinidade , Estresse Fisiológico/fisiologia , Trealose/metabolismo
18.
Malays J Med Sci ; 26(4): 39-46, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31496892

RESUMO

BACKGROUNDS: Renal ischemia/reperfusion (RIR) is a major cause of kidney dysfunction in clinic. The main objective of this study was to investigate the effect of pre-conditioning ischemia (IPC) and zinc (Zn) supplementation on renal RIR injury. METHODS: A total of 63 unilateral nephrectomised male and female Wistar rats were divided into five groups. Group 1 (ShOPR): Rats as sham-operated group were subjected to surgical procedure without RIR. Group 2 (Isch): Rats underwent RIR (left kidney ischemia for 30 min followed by 48 h reperfusion). Group 3 (Zn+Isch): Rats were treated as group 2 but they received Zn sulphate (30 mg/kg) 1 h before induction of RIR. Group 4 (IPC+Isch): Rats were treated as group 2 but they underwent 1 min of ischemia followed by 3 min reperfusion as IPC, which was repeated for three times before induction of RIR. Group 5 (Zn+IPC+Isch): Rats were subjected to receive both Zn sulphate and IPC before induction of RIR. Urine samples were collected in the last 6 h of reperfusion, and finally biochemical and histological measurements were performed. RESULTS: The serum level of creatinine (Cr), normalised kidney weight (KW) and kidney tissue damage score (KTDS) increased by RIR alone significantly (P < 0.05). These parameters were attenuated statistically by Zn supplementation (P < 0.05). However, IPC alone or co-treatment of Zn and IPC did not improve the biochemical and histological markers altered by RIR injury. CONCLUSION: Zn supplementation had a protective role against RIR while such protective effect was not observed by IPC alone or by co-treatment of Zn and IPC.

19.
J Cell Mol Med ; 22(7): 3397-3407, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29671939

RESUMO

We previously demonstrated that pre-conditioning with CpG oligonucleotide (ODN) 1668 induces quick up-regulation of gene expression 3 hours post-murine myocardial ischaemia/reperfusion (I/R) injury, terminating inflammatory processes that sustain I/R injury. Now, performing comprehensive microarray and biocomputational analyses, we sought to further enlighten the "black box" beyond these first 3 hours. C57BL/6 mice were pretreated with either CpG 1668 or with control ODN 1612, respectively. Sixteen hours later, myocardial ischaemia was induced for 1 hour in a closed-chest model, followed by reperfusion for 24 hours. RNA was extracted from hearts, and labelled cDNA was hybridized to gene microarrays. Data analysis was performed with BRB ArrayTools and Ingenuity Pathway Analysis. Functional groups mediating restoration of cellular integrity were among the top up-regulated categories. Genes known to influence cardiomyocyte survival were strongly induced 24 hours post-I/R. In contrast, proinflammatory pathways were down-regulated. Interleukin-10, an upstream regulator, suppressed specifically selected proinflammatory target genes at 24 hours compared to 3 hours post-I/R. The IL1 complex is supposed to be one regulator of a network increasing cardiovascular angiogenesis. The up-regulation of numerous protective pathways and the suppression of proinflammatory activity are supposed to be the genetic correlate of the cardioprotective effects of CpG 1668 pre-conditioning.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/genética , Oligodesoxirribonucleotídeos/farmacologia , Animais , Cardiotônicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Interleucina-10/genética , Interleucina-10/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fatores de Tempo , Regulação para Cima/efeitos dos fármacos
20.
Int J Mol Sci ; 19(10)2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30248927

RESUMO

This paper tells the story of how hormesis became recognized as a fundamental concept in biology, affecting toxicology, microbiology, medicine, public health, agriculture, and all areas related to enhancing biological performance. This paper assesses how hormesis enhances resilience to normal aging and protects against a broad spectrum of neurodegenerative, cardiovascular, and other diseases, as well as trauma and other threats to health and well-being. This paper also explains the application of hormesis to several neurodegenerative diseases such as Parkinson's and Huntington's disease, macrophage polarization and its systematic adaptive protections, and the role of hormesis in enhancing stem cell functioning and medical applications.


Assuntos
Hormese/fisiologia , Animais , Doenças Cardiovasculares/metabolismo , Hormese/genética , Humanos , Modelos Biológicos , Doenças Neurodegenerativas/metabolismo
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