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1.
Int J Mol Sci ; 22(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34281289

RESUMO

Several recent studies have shown that citric acid/citrate (CA) can confer abiotic stress tolerance to plants. Exogenous CA application leads to improved growth and yield in crop plants under various abiotic stress conditions. Improved physiological outcomes are associated with higher photosynthetic rates, reduced reactive oxygen species, and better osmoregulation. Application of CA also induces antioxidant defense systems, promotes increased chlorophyll content, and affects secondary metabolism to limit plant growth restrictions under stress. In particular, CA has a major impact on relieving heavy metal stress by promoting precipitation, chelation, and sequestration of metal ions. This review summarizes the mechanisms that mediate CA-regulated changes in plants, primarily CA's involvement in the control of physiological and molecular processes in plants under abiotic stress conditions. We also review genetic engineering strategies for CA-mediated abiotic stress tolerance. Finally, we propose a model to explain how CA's position in complex metabolic networks involving the biosynthesis of phytohormones, amino acids, signaling molecules, and other secondary metabolites could explain some of its abiotic stress-ameliorating properties. This review summarizes our current understanding of CA-mediated abiotic stress tolerance and highlights areas where additional research is needed.


Assuntos
Ácido Cítrico/metabolismo , Ácido Cítrico/farmacologia , Plantas/efeitos dos fármacos , Plantas/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Secas , Engenharia Genética , Resposta ao Choque Térmico/efeitos dos fármacos , Inativação Metabólica , Metais Pesados/farmacocinética , Metais Pesados/toxicidade , Modelos Biológicos , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Plantas/metabolismo , Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/efeitos dos fármacos , Estresse Fisiológico/genética
2.
BMC Pregnancy Childbirth ; 21(1): 515, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34281501

RESUMO

BACKGROUND: In light of the pandemic, pregnant women are particularly vulnerable to increased psychological distress and in need of imperative preventive measures. This study aimed to investigate the impact of the pandemic on mental health, lifestyle adaptations, and their determinants among pregnant women in the United Arab Emirates. METHODS: A survey was conducted electronically between June and August 2020. Pregnant women were recruited from prenatal clinics in the UAE and invited to participate in an online survey developed on Google Forms. The questionnaire included socio-demographic characteristics, the Impact of Event Scale- Revised, the Perceived Support Scale and lifestyle-related factors. RESULTS: A total of 384 pregnant women completed the questionnaire of whom 20.6% were in their 1st trimester, 46.1% in their 2nd and 33.3% in their 3rd trimester. The mean IES-R score for the respondents was 26.15 ± 13.55, corresponding to a mild stressful impact, which did not differ significantly among trimesters of pregnancy. Pregnant women expressed increased stress from staying home (64%), work (40%), feeling frightened (66%) and apprehensive (59%). Women reported increased support and sharing their feelings with family members (59%), mainly in the 1st and 3rd trimester of pregnancy (P < 0.05). There was a greater attention to mental health (48%), resting time (55.3%), and relaxing time (57.3%); while a decreased amount of time was spent engaging in physical activities (53.6%), which differed significantly between trimesters (P = 0.02). CONCLUSIONS: The COVID-19 pandemic was associated with a mild stressful impact among pregnant women in the UAE, braced by strong family support and self-care mental health behaviors.


Assuntos
Adaptação Fisiológica , Adaptação Psicológica , COVID-19 , Gestantes/psicologia , Adulto , Controle de Doenças Transmissíveis , Estudos Transversais , Exercício Físico , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Gravidez , Apoio Social , Estresse Psicológico/etiologia , Inquéritos e Questionários , Emirados Árabes Unidos
3.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200124

RESUMO

Identifying and characterizing cold responsive genes in Fragaria vesca associated with or responsible for low temperature tolerance is a vital part of strawberry cultivar development. In this study we have investigated the transcript levels of eight genes, two dehydrin genes, three putative ABA-regulated genes, two cold-inducible CBF genes and the alcohol dehydrogenase gene, extracted from leaf and crown tissues of three F. vesca genotypes that vary in cold tolerance. Transcript levels of the CBF/DREB1 transcription factor FvCBF1E exhibited stronger cold up-regulation in comparison to FvCBF1B.1 in all genotypes. Transcripts of FvADH were highly up-regulated in both crown and leaf tissues from all three genotypes. In the 'ALTA' genotype, FvADH transcripts were significantly higher in leaf than crown tissues and more than 10 to 20-fold greater than in the less cold-tolerant 'NCGR1363' and 'FDP817' genotypes. FvGEM, containing the conserved ABRE promoter element, transcript was found to be cold-regulated in crowns. Direct comparison of the kinetics of transcript and protein accumulation of dehydrins was scrutinized. In all genotypes and organs, the changes of XERO2 transcript levels generally preceded protein changes, while levels of COR47 protein accumulation preceded the increases in COR47 RNA in 'ALTA' crowns.


Assuntos
Adaptação Fisiológica , Temperatura Baixa , Fragaria/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fragaria/genética , Fragaria/metabolismo , Genótipo
4.
Biol Lett ; 17(7): 20210071, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34256577

RESUMO

The ocean is undergoing warming and acidification. Thermal tolerance is affected both by evolutionary adaptation and developmental plasticity. Yet, thermal tolerance in animals adapted to simultaneous warming and acidification is unknown. We experimentally evolved the ubiquitous copepod Acartia tonsa to future combined ocean warming and acidification conditions (OWA approx. 22°C, 2000 µatm CO2) and then compared its thermal tolerance relative to ambient conditions (AM approx. 18°C, 400 µatm CO2). The OWA and AM treatments were reciprocally transplanted after 65 generations to assess effects of developmental conditions on thermal tolerance and potential costs of adaptation. Treatments transplanted from OWA to AM conditions were assessed at the F1 and F9 generations following transplant. Adaptation to warming and acidification, paradoxically, reduces both thermal tolerance and phenotypic plasticity. These costs of adaptation to combined warming and acidification may limit future population resilience.


Assuntos
Copépodes , Aclimatação , Adaptação Fisiológica , Animais , Mudança Climática , Aquecimento Global , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar , Temperatura
5.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199458

RESUMO

As we age, our bodies accrue damage in the form of DNA mutations. These mutations lead to the generation of sub-optimal proteins, resulting in inadequate cellular homeostasis and senescence. The build-up of senescent cells negatively affects the local cellular micro-environment and drives ageing associated disease, including neurodegeneration. Therefore, limiting the accumulation of DNA damage is essential for healthy neuronal populations. The naked mole rats (NMR) are from eastern Africa and can live for over three decades in chronically hypoxic environments. Despite their long lifespan, NMRs show little to no biological decline, neurodegeneration, or senescence. Here, we discuss molecular pathways and adaptations that NMRs employ to maintain genome integrity and combat the physiological and pathological decline in organismal function.


Assuntos
Adaptação Fisiológica/genética , Senescência Celular/genética , Dano ao DNA/genética , Estresse Oxidativo/genética , Envelhecimento/genética , Animais , DNA/genética , Homeostase , Ratos-Toupeira/genética , Estresse Oxidativo/fisiologia
6.
BMC Plant Biol ; 21(1): 317, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215191

RESUMO

BACKGROUND: Entering and exiting winter dormancy present important trade-offs between growth and survival at northern latitudes. Many forest trees display local adaptation across latitude in traits associated with these phenology transitions. Transfers of a species outside its native range introduce the species to novel combinations of environmental conditions potentially requiring different combinations of alleles to optimize growth and survival. In this study, we performed genome wide association analyses and a selection scan in a P. trichocarpa mapping population derived from crossings between clones collected across the native range and introduced into Sweden. GWAS analyses were performed using phenotypic data collected across two field seasons and in a controlled phytotron experiment. RESULTS: We uncovered 584 putative candidate genes associated with spring and autumn phenology traits as well as with growth. Many regions harboring variation significantly associated with the initiation of leaf shed and leaf autumn coloring appeared to have been evolving under positive selection in the native environments of P. trichocarpa. A comparison between the candidate genes identified with results from earlier GWAS analyses performed in the native environment found a smaller overlap for spring phenology traits than for autumn phenology traits, aligning well with earlier observations that spring phenology transitions have a more complex genetic basis than autumn phenology transitions. CONCLUSIONS: In a small and structured introduced population of P. trichocarpa, we find complex genetic architectures underlying all phenology and growth traits, and identify multiple putative candidate genes despite the limitations of the study population.


Assuntos
Adaptação Fisiológica/genética , Espécies Introduzidas , Populus/genética , Populus/fisiologia , Ontologia Genética , Estudos de Associação Genética , Padrões de Herança/genética , Fenótipo , Característica Quantitativa Herdável , Estações do Ano
7.
Nat Commun ; 12(1): 4306, 2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34262034

RESUMO

We lack a thorough understanding of the origin and maintenance of standing genetic variation that enables rapid evolutionary responses of natural populations. Whole genome sequencing of a resurrected Daphnia population shows that standing genetic variation in over 500 genes follows an evolutionary trajectory that parallels the pronounced and rapid adaptive evolution of multiple traits in response to predator-driven natural selection and its subsequent relaxation. Genetic variation carried by only five founding individuals from the regional genotype pool is shown to suffice at enabling the observed evolution. Our results provide insight on how natural populations can acquire the genomic variation, through colonization by a few regional genotypes, that fuels rapid evolution in response to strong selection pressures. While these evolutionary responses in our study population involved hundreds of genes, we observed no evidence of genetic erosion.


Assuntos
Adaptação Fisiológica/genética , Daphnia/fisiologia , Efeito Fundador , Variação Genética , Animais , Evolução Biológica , Daphnia/genética , Frequência do Gene , Genética Populacional , Genoma/genética , Genótipo , Fenótipo , Seleção Genética
8.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199720

RESUMO

The underground reserve (root) has been an uncharted research territory with its untapped genetic variation yet to be exploited. Identifying ideal traits and breeding new rice varieties with efficient root system architecture (RSA) has great potential to increase resource-use efficiency and grain yield, especially under direct-seeded rice, by adapting to aerobic soil conditions. In this review, we tried to mine the available research information on the direct-seeded rice (DSR) root system to highlight the requirements of different root traits such as root architecture, length, number, density, thickness, diameter, and angle that play a pivotal role in determining the uptake of nutrients and moisture at different stages of plant growth. RSA also faces several stresses, due to excess or deficiency of moisture and nutrients, low or high temperature, or saline conditions. To counteract these hindrances, adaptation in response to stress becomes essential. Candidate genes such as early root growth enhancer PSTOL1, surface rooting QTL qSOR1, deep rooting gene DRO1, and numerous transporters for their respective nutrients and stress-responsive factors have been identified and validated under different circumstances. Identifying the desired QTLs and transporters underlying these traits and then designing an ideal root architecture can help in developing a suitable DSR cultivar and aid in further advancement in this direction.


Assuntos
Adaptação Fisiológica/fisiologia , Oryza/fisiologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia , Sementes/fisiologia , Germinação/fisiologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Locos de Características Quantitativas/genética , Sementes/genética , Sementes/crescimento & desenvolvimento
9.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204386

RESUMO

The "Extreme Exercise Hypothesis" states that when individuals perform training beyond the ideal exercise dose, a decline in the beneficial effects of physical activity occurs. This is due to significant changes in myocardial structure and function, such as hemodynamic alterations, cardiac chamber enlargement and hypertrophy, myocardial inflammation, oxidative stress, fibrosis, and conduction changes. In addition, an increased amount of circulating biomarkers of exercise-induced damage has been reported. Although these changes are often reversible, long-lasting cardiac damage may develop after years of intense physical exercise. Since several features of the athlete's heart overlap with arrhythmogenic cardiomyopathy (ACM), the syndrome of "exercise-induced ACM" has been postulated. Thus, the distinction between ACM and the athlete's heart may be challenging. Recently, an autoimmune mechanism has been discovered in ACM patients linked to their characteristic junctional impairment. Since cardiac junctions are similarly impaired by intense physical activity due to the strong myocardial stretching, we propose in the present work the novel hypothesis of an autoimmune response in endurance athletes. This investigation may deepen the knowledge about the pathological remodeling and relative activated mechanisms induced by intense endurance exercise, potentially improving the early recognition of whom is actually at risk.


Assuntos
Atletas , Autoanticorpos/sangue , Biomarcadores/sangue , Resistência Física , Adaptação Fisiológica , Animais , Displasia Arritmogênica Ventricular Direita/etiologia , Displasia Arritmogênica Ventricular Direita/metabolismo , Displasia Arritmogênica Ventricular Direita/fisiopatologia , Autoimunidade , Suscetibilidade a Doenças , Exercício Físico , Humanos , Miocárdio/metabolismo , Miocárdio/patologia , Remodelação Ventricular
10.
Artigo em Inglês | MEDLINE | ID: mdl-34203851

RESUMO

The aim of this study was to investigate how physical limitations after ACS influence patients' quality of life and health perception. This was a longitudinal clinical study. We recruited 146 patients diagnosed with ACS. The patients performed a stress test (Bruce's protocol) for the evaluation of physical limitations and were classified according to the test result: without physical limitations (more than 10 METS), with some physical limitations (7 to 9 METS), and with high physical limitations (less than 6 METS). Significant differences were found between the three groups immediately after the diagnosis of ACS and after a period of three months, regarding health perception, anxiety, depression, sexual relationships, distress, and adjustment to disease. These differences resulted larger between the group with less limitations and the group with higher limitations. After 3 months, however, there was an overall improvement in all variables. In conclusion, physical limitations after ACS seem to influence perceived quality of life determined by measuring general health, vitality, total adaptation, emotional role, social adaptation, depression, and anxiety. Therefore, the highest the physical limitations, the poorer the psychological conditions and vice versa, even 3 months after ACS diagnosis.


Assuntos
Síndrome Coronariana Aguda , Adaptação Fisiológica , Adaptação Psicológica , Ansiedade/epidemiologia , Depressão/epidemiologia , Humanos , Estudos Longitudinais , Qualidade de Vida , Estresse Psicológico
11.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209663

RESUMO

The myotendinous junction (MTJ) is the muscle-tendon interface and constitutes an integrated mechanical unit to force transmission. Joint immobilization promotes muscle atrophy via disuse, while physical exercise can be used as an adaptative stimulus. In this study, we aimed to investigate the components of the MTJ and their adaptations and the associated elements triggered with aquatic training after joint immobilization. Forty-four male Wistar rats were divided into sedentary (SD), aquatic training (AT), immobilization (IM), and immobilization/aquatic training (IMAT) groups. The samples were processed to measure fiber area, nuclear fractal dimension, MTJ nuclear density, identification of telocytes, sarcomeres, and MTJ perimeter length. In the AT group, the maintenance of ultrastructure and elements in the MTJ region were observed; the IM group presented muscle atrophy effects with reduced MTJ perimeter; the IMAT group demonstrated that aquatic training after joint immobilization promotes benefits in the muscle fiber area and fractal dimension, in the MTJ region shows longer sarcomeres and MTJ perimeter. We identified the presence of telocytes in the MTJ region in all experimental groups. We concluded that aquatic training is an effective rehabilitation method after joint immobilization due to reduced muscle atrophy and regeneration effects on MTJ in rats.


Assuntos
Adaptação Fisiológica , Imobilização , Articulações , Condicionamento Físico Animal , Esforço Físico , Tendões/fisiologia , Animais , Masculino , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/ultraestrutura , Ratos , Sarcômeros/ultraestrutura , Tendões/citologia , Tendões/ultraestrutura
12.
Ying Yong Sheng Tai Xue Bao ; 32(6): 2070-2078, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34212613

RESUMO

We investigated leaf tissue structure, leaf epidermis characteristics and chloroplast ultrastructure of Polygonum viviparum at different altitudes (2300, 3200 and 3900 m) on the Qilian Mountain, using paraffin section, scanning electron microscopy and transmission electron microscopy methods. The results showed that plant leaves were typical bifacial. With increasing altitude, the number of leaf epidermal hair reduced but the diameter of hair increased, with more compact of the cuticular wax layer on leaf lower epidermis. Leaf thickness reached a maximum at 3200 m and was increased by 39.6% and 50.5%, respectively, compared with that from 2300 m and 3900 m. From 2300 m to 3200 m, the cell layers of palisade tissue increased from two to three, while intercellular space decreased. The cell layer of spongy tissue did not change, whereas intercellular space increased with increasing altitude. At 3900 m, the number of cell layer of palisade tissue reduced to two, epidermal cell volume and the intercellular space of palisade tissue increased while the intercellular space of spongy tissue decreased. The thickness of epidermal cell increased. There was no significant difference among three altitudes in the number of cell layers. The accumulation of surface appurtenances and the substomatal appendages, and stomata density of lower epidermis increased with altitude. Meanwhile, the position of stomata changed from arched epidermis to invagination. From 2300 m to 3200 m, the grana lamella increased from 6-9 to 8-12 and then reduced to 2-3 at 3900 m. The number of grana decreased, the lamellae became dense, the arrangement direction of grana was irregular at 3900 m. The chloroplasts swelling and the envelope partially degradation could be observed. The correlations among the anatomical characteristics of leaves indicated an apparent co-evolution between parts of anatomical indices in the leaves. In particular, indices such as spongy tissue thickness exhibited high plasticity across altitudes. Our results suggested that diffe-rences in anatomical structure and ultrastructure characteristics of P. viviparum along altitude were adaptation strategies for the complicated alpine heterogeneous habitats.


Assuntos
Polygonum , Adaptação Fisiológica , Altitude , Ecossistema , Folhas de Planta
13.
Extremophiles ; 25(4): 385-392, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34196828

RESUMO

In piezophilic microorganisms, enzymes are optimized to perform under high hydrostatic pressure. The two major reported mechanisms responsible for such adaptation in bacterial species are changes in amino acids in the protein structure, favoring their activity and stability under high-pressure conditions, and the possible accumulation of micromolecular co-solutes in the cytoplasm. Recently, the accumulation of glutamate in the cytoplasm of piezophilic Desulfovibrio species has been reported under high-pressure growth conditions. In this study, analysis of the effect of glutamate on the enzymatic activity of the thioredoxin reductase/thioredoxin enzymatic complex of either a piezosensitive or a piezophilic microorganism confirms its role as a protective co-solute. Analysis of the thioredoxin structures suggests an adaptation both to the presence of glutamate and to high hydrostatic pressure in the enzyme from the piezophilic strain. Indeed, the presence of large surface pockets could counterbalance the overall compression that occurs at high hydrostatic pressure to maintain enzymatic activity. A lower isoelectric point and a greater dipolar moment than that of thioredoxin from the piezosensitive strain would allow the protein from the piezophilic strain to compensate for the presence of the charged amino acid glutamate to interact with its partner.


Assuntos
Desulfovibrio , Ácido Glutâmico , Adaptação Fisiológica , Pressão Hidrostática , Tiorredoxinas
14.
Zool Res ; 42(4): 502-513, 2021 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-34254744

RESUMO

Persistent uplift means the Qinghai-Tibet Plateau (QTP) is an ideal natural laboratory to investigate genome evolution and adaptation within highland environments. However, how paleogeographic and paleoclimatic events influence the genome and population of endemic fish species remains unclear. Glyptosternon maculatum is an ancient endemic fish found on the QTP and the only critically endangered species in the Sisoridae family. Here, we found that major transposons in the G. maculatum genome showed episodic bursts, consistent with contemporaneous geological and climatic events during the QTP formation. Notably, histone genes showed significant expansion in the G. maculatum genome, which may be mediated by long interspersed nuclear elements (LINE) repetitive element duplications. Population analysis showed that ancestral G. maculatum populations experienced two significant depressions 2.6 million years ago (Mya) and 10 000 years ago, exhibiting excellent synchronization with Quaternary glaciation and the Younger Dryas, respectively. Thus, we propose that paleogeography and paleoclimate were dominating driving forces for population dynamics in endemic fish on the QTP. Tectonic movements and temperature fluctuation likely destroyed the habitat and disrupted the drainage connectivity among populations. These factors may have caused severe bottlenecks and limited migration among ancestral G. maculatum populations, resulting in the low genetic diversity and endangered status of the species today.


Assuntos
Adaptação Fisiológica , Evolução Biológica , Ecossistema , Peixes/genética , Genoma , Animais , Clima , Tibet
15.
Int J Mol Sci ; 22(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34066274

RESUMO

Polyamines are ubiquitous, low-molecular-weight aliphatic compounds, present in living organisms and essential for cell growth and differentiation. Copper amine oxidases (CuAOs) oxidize polyamines to aminoaldehydes releasing ammonium and hydrogen peroxide, which participates in the complex network of reactive oxygen species acting as signaling molecules involved in responses to biotic and abiotic stresses. CuAOs have been identified and characterized in different plant species, but the most extensive study on a CuAO gene family has been carried out in Arabidopsis thaliana. Growing attention has been devoted in the last years to the investigation of the CuAO expression pattern during development and in response to an array of stress and stress-related hormones, events in which recent studies have highlighted CuAOs to play a key role by modulation of a multilevel phenotypic plasticity expression. In this review, the attention will be focused on the involvement of different AtCuAOs in the IAA/JA/ABA signal transduction pathways which mediate stress-induced phenotypic plasticity events.


Assuntos
Adaptação Fisiológica , Amina Oxidase (contendo Cobre)/metabolismo , Regulação da Expressão Gênica de Plantas , Hormônios/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas/enzimologia , Estresse Fisiológico , Plantas/imunologia , Plantas/metabolismo
16.
Int J Mol Sci ; 22(10)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34068993

RESUMO

The human cathelicidin LL-37 is a multifunctional peptide of the human innate immune system. Among the various functions of LL-37, its antimicrobial activity is important in controlling the microorganisms of the human body. The target molecules of LL-37 in bacteria include membrane lipids, lipopolysaccharides (LPS), lipoteichoic acid (LTA), proteins, DNA and RNA. In this mini-review, we summarize the entity of LL-37 structural data determined over the last 15 years and specifically discuss features implicated in the interactions with lipid-like molecules. For this purpose, we discuss partial and full-length structures of LL-37 determined in the presence of membrane-mimicking detergents. This constantly growing structural database is now composed of monomers, dimers, tetramers, and fiber-like structures. The diversity of these structures underlines an unexpected plasticity and highlights the conformational and oligomeric adaptability of LL-37 necessary to target different molecular scaffolds. The recent co-crystal structures of LL-37 in complex with detergents are particularly useful to understand how these molecules mimic lipids and LPS to induce oligomerization and fibrillation. Defined detergent binding sites provide deep insights into a new class of peptide scaffolds, widening our view on the fascinating world of the LL-37 structural factotum. Together, the new structures in their evolutionary context allow for the assignment of functionally conserved residues in oligomerization and target interactions. Conserved phenylalanine and arginine residues primarily mediate those interactions with lipids and LPS. The interactions with macromolecules such as proteins or DNA remain largely unexplored and open a field for future studies aimed at structures of LL-37 complexes. These complexes will then allow for the structure-based rational design of LL-37-derived peptides with improved antibiotic properties.


Assuntos
Adaptação Fisiológica , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/química , Bactérias/efeitos dos fármacos , Membrana Celular/química , Lipídeos/química , Bactérias/metabolismo , Humanos
19.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072612

RESUMO

The BAG proteins are a family of multi-functional co-chaperones. In plants, BAG proteins were found to play roles both in abiotic and biotic stress tolerance. However, the function of Arabidopsis BAG2 remains largely unknown, whereas BAG6 is required for plants' defense to pathogens, although it remains unknown whether BAG6 is involved in plants' tolerance to abiotic stresses. Here, we show that both BAG2 and BAG6 are expressed in various tissues and are upregulated by salt, mannitol, and heat treatments and by stress-related hormones including ABA, ethylene, and SA. Germination of bag2, bag6 and bag2 bag6 seeds is less sensitive to ABA compared to the wild type (WT), whereas BAG2 and BAG6 overexpression lines are hypersensitive to ABA. bag2, bag6, and bag2 bag6 plants show higher survival rates than WT in drought treatment but display lower survival rates in heat-stress treatment. Consistently, these mutants showed differential expression of several stress- and ABA-related genes such as RD29A, RD29B, NCED3 and ABI4 compared to the WT. Furthermore, these mutants exhibit lower levels of ROS after drought and ABA treatment but higher ROS accumulation after heat treatment than the WT. These results suggest that BAG2 and BAG6 are negatively involved in drought stress but play a positive role in heat stress in Arabidopsis.


Assuntos
Adaptação Fisiológica , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas Mitocondriais/genética , Chaperonas Moleculares/genética , Proteínas Nucleares/genética , Estresse Fisiológico , Proteínas de Arabidopsis/metabolismo , Secas , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/metabolismo , Mutação , Proteínas Nucleares/metabolismo , Desenvolvimento Vegetal/genética , Reguladores de Crescimento de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
20.
Int J Mol Sci ; 22(11)2021 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-34071053

RESUMO

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.


Assuntos
Transtorno Depressivo Maior/fisiopatologia , Sistema Hipotálamo-Hipofisário/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Pregnanolona/fisiologia , Adaptação Fisiológica , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Doença Crônica , Corticosterona/metabolismo , Transtorno Depressivo Maior/tratamento farmacológico , Retroalimentação Fisiológica , Feminino , Agonistas de Receptores de GABA-A/uso terapêutico , Humanos , Masculino , Modelos Biológicos , Pregnanolona/biossíntese , Receptores de GABA-A/fisiologia , Caracteres Sexuais , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estresse Fisiológico , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Ácido gama-Aminobutírico/fisiologia
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