311 research outputs found
Behind the loss of salinity resistance during domestication: alternative eco-physiological strategies are revealed in tomato clade.
Salinity stress impairs growth and physiological performance in tomato, which is one of the most economically important vegetables and is widely cultivated in arid and semi-arid areas of the world. Plant landraces, which are heterogeneous, local adaptations of domesticated species, offer a unique opportunity to valorize available germplasm, underpinning the productivity, resilience, and adaptive capacity of staple crops in vulnerable environments. Here, we investigated the response of fully mature tomato plants from a commercial variety, an ancestral wild relative, and a landrace under short-term salinity exposure, as well as their ability to recover upon cessation of stress. The heterogeneous panel evaluated in this study revealed different adaptative strategies to cope the stress. Our data highlighted the ability of the tomato clade to handle low and intermediate salinity stress for short-term exposure time, as well as its capacity to recover after the cessation of stress, although inter- and intraspecific variations in morphological and physiological responses to salinity were observed. Overall, the landrace and the wild type performed similarly to control conditions under low salinity, demonstrating an improved ability to maintain ionic balance. In contrast, the commercial genotype showed susceptibility and severe symptoms even under low salinity, with pronounced reductions in K+/Na+ ratio, PSII photochemical efficiency, and photosynthetic pigments. This research confirmed that improved salt tolerant genotypes can lead to substantial, positive impacts on horticultural production. While the salt tolerance mechanism of domesticated tomato was efficient under mild stress conditions, it failed at higher salinity levels
Substrate mechanics controls adipogenesis through YAP phosphorylation by T dictating cell spreading
The mechanoregulated proteins YAP/TAZ are involved in the adipogenic/osteogenic switch of mesenchymal stem cells (MSCs).
MSC fate decision can be unbalanced by controlling substrate mechanics, in turn altering the transmission of tension through cell cytoskeleton. MSCs have been proposed for orthopedic and reconstructive surgery applications. Thus, a tight control of their adipogenic potential is required in order to avoid their drifting towards fat tissue. Substrate mechanics has been shown to drive MSC commitment and to regulate YAP/TAZ protein shuttling and turnover. The mechanism by which YAP/TAZ co-transcriptional activity is mechanically regulated during MSC fate acquisition is still debated.
Here, we design few bioengineering tools suited to disentangle the contribution of mechanical from biological stimuli to MSC adipogenesis. We demonstrate that the mechanical repression of YAP happens through its phosphorylation, is purely mediated by cell spreading downstream of substrate mechanics as dictated by dimensionality. YAP repression is sufficient to prompt MSC adipogenesis, regardless of a permissive biological environment, TEAD nuclear presence or focal adhesion stabilization.
Finally, by harnessing the potential of YAP mechanical regulation, we propose a practical example of the exploitation of adipogenic transdifferentiation in tumors
Evidence for discrete modes of YAP1 signaling via mRNA splice isoforms in development and disease
Yes-associated protein 1 (YAP1) is a transcriptional co-activator downstream of Hippo pathway. The pathway exerts crucial roles in organogenesis and its dysregulation is associated with the spreading of different cancer types. YAP1 gene encodes for multiple protein isoforms, whose specific functions are not well defined. We demonstrate the splicing of isoform-specific mRNAs is controlled in a stage- and tissue-specific fashion. We designed expression vectors encoding for the most-represented isoforms of YAP1 with either one or two WW domains and studied their specific signaling activities in YAP1 knock-out cell lines. YAP1 isoforms display both common and unique functions and activate distinct transcriptional programs, as the result of their unique protein interactomes. By generating TEAD-based transcriptional reporter cell lines, we demonstrate individual YAP1 isoforms display unique effects on cell proliferation and differentiation. Finally, we illustrate the complexity of the regulation of Hippo-YAP1 effector in physiological and in pathological conditions of the heart
Proteomics and mathematical modeling of longitudinal CSF differentiates fast versus slow ALS progression
Objective: Amyotrophic lateral sclerosis (ALS) is a heterogeneous disease with a complex etiology that lacks biomarkers predicting disease progression. The objective of this study was to use longitudinal cerebrospinal fluid (CSF) samples to identify biomarkers that distinguish fast progression (FP) from slow progression (SP) and assess their temporal response.Methods: We utilized mass spectrometry (MS)-based proteomics to identify candidate biomarkers using longitudinal CSF from a discovery cohort of SP and FP ALS patients. Immunoassays were used to quantify and validate levels of the top biomarkers. A state-transition mathematical model was created using the longitudinal MS data that also predicted FP versus SP.Results: We identified a total of 1148 proteins in the CSF of all ALS patients. Pathway analysis determined enrichment of pathways related to complement and coagulation cascades in FPs and synaptogenesis and glucose metabolism in SPs. Longitudinal analysis revealed a panel of 59 candidate markers that could segregate FP and SP ALS. Based on multivariate analysis, we identified three biomarkers (F12, RBP4, and SERPINA4) as top candidates that segregate ALS based on rate of disease progression. These proteins were validated in the discovery and a separate validation cohort. Our state-transition model determined that the overall variance of the proteome over time was predictive of the disease progression rate.Interpretation: We identified pathways and protein biomarkers that distinguish rate of ALS disease progression. A mathematical model of the CSF proteome determined that the change in entropy of the proteome over time was predictive of FP versus SP
Substrate mechanics controls adipogenesis through YAP phosphorylation by dictating cell spreading
The mechanoregulated proteins YAP/TAZ are involved in the adipogenic/osteogenic switch of mesenchymal stem cells (MSCs).MSC fate decision can be unbalanced by controlling substrate mechanics, in turn altering the transmission of tension through cell cytoskeleton. MSCs have been proposed for orthopedic and reconstructive surgery applications. Thus, a tight control of their adipogenic potential is required in order to avoid their drifting towards fat tissue. Substrate mechanics has been shown to drive MSC commitment and to regulate YAP/TAZ protein shuttling and turnover. The mechanism by which YAP/TAZ co-transcriptional activity is mechanically regulated during MSC fate acquisition is still debated.Here, we design few bioengineering tools suited to disentangle the contribution of mechanical from biological stimuli to MSC adipogenesis. We demonstrate that the mechanical repression of YAP happens through its phosphorylation, is purely mediated by cell spreading downstream of substrate mechanics as dictated by dimensionality. YAP repression is sufficient to prompt MSC adipogenesis, regardless of a permissive biological environment, TEAD nuclear presence or focal adhesion stabilization.Finally, by harnessing the potential of YAP mechanical regulation, we propose a practical example of the exploitation of adipogenic transdifferentiation in tumors.</p
Evidence for cognitive vestibular integration impairment in idiopathic scoliosis patients
<p>Abstract</p> <p>Background</p> <p>Adolescent idiopathic scoliosis is characterized by a three-dimensional deviation of the vertebral column and its etiopathogenesis is unknown. Various factors cause idiopathic scoliosis, and among these a prominent role has been attributed to the vestibular system. While the deficits in sensorimotor transformations have been documented in idiopathic scoliosis patients, little attention has been devoted to their capacity to integrate vestibular information for cognitive processing for space perception. Seated idiopathic scoliosis patients and control subjects experienced rotations of different directions and amplitudes in the dark and produced saccades that would reproduce their perceived spatial characteristics of the rotations (vestibular condition). We also controlled for possible alteration of the oculomotor and vestibular systems by measuring the subject's accuracy in producing saccades towards memorized peripheral targets in absence of body rotation and the gain of their vestibulo-ocular reflex.</p> <p>Results</p> <p>Compared to healthy controls, the idiopathic scoliosis patients underestimated the amplitude of their rotations. Moreover, the results revealed that idiopathic scoliosis patients produced accurate saccades to memorized peripheral targets in absence of body rotation and that their vestibulo-ocular reflex gain did not differ from that of control participants.</p> <p>Conclusion</p> <p>Overall, results of the present study demonstrate that idiopathic scoliosis patients have an alteration in cognitive integration of vestibular signals. It is possible that severe spine deformity developed partly due to impaired vestibular information travelling from the cerebellum to the vestibular cortical network or alteration in the cortical mechanisms processing the vestibular signals.</p
Monoamine related functional gene variants and relationships to monoamine metabolite concentrations in CSF of healthy volunteers
BACKGROUND: Concentrations of monoamine metabolites in human cerebrospinal fluid (CSF) have been used extensively as indirect estimates of monoamine turnover in the brain. CSF monoamine metabolite concentrations are partly determined by genetic influences. METHODS: We investigated possible relationships between DNA polymorphisms in the serotonin 2C receptor (HTR2C), the serotonin 3A receptor (HTR3A), the dopamine D(4 )receptor (DRD4), and the dopamine β-hydroxylase (DBH) genes and CSF concentrations of 5-hydroxyindolacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in healthy volunteers (n = 90). RESULTS: The HTR3A 178 C/T variant was associated with 5-HIAA levels (p = 0.02). The DBH-1021 heterozygote genotype was associated with 5-HIAA (p = 0.0005) and HVA (p = 0.009) concentrations. Neither the HTR2C Cys23Ser variant, nor the DRD4 -521 C/T variant were significantly associated with any of the monoamine metabolites. CONCLUSIONS: The present results suggest that the HTR3A and DBH genes may participate in the regulation of dopamine and serotonin turnover rates in the central nervous system
The 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) reduces palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers
RATIONALE: Brain 5-HT2C receptors form part of a neural network that controls eating behaviour. 5-HT2C receptor agonists decrease food intake by activating proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus, but recent research in rodents has suggested that 5-HT2C receptor agonists may also act via dopaminergic circuitry to reduce the rewarding value of food and other reinforcers. No mechanistic studies on the effects of 5-HT2C agonists on food intake in humans have been conducted to date. OBJECTIVES: The present study examined the effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) on food consumption, eating microstructure and blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) responses to food pictures in healthy female volunteers. METHODS: In a double-blind, placebo-controlled, crossover design, participants were randomized immediately after screening to receive oral mCPP (30mg) in a single morning dose, or placebo, in a counterbalanced order. Test foods were served from a Universal Eating Monitor (UEM) that measured eating rate and fMRI BOLD signals to the sight of food and non-food images were recorded. RESULTS: mCPP decreased rated appetite and intake of a palatable snack eaten in the absence of hunger but had no significant effect on the consumption of a pasta lunch (although pasta eating rate was reduced). mCPP also decreased BOLD fMRI responses to the sight of food pictures in areas of reward-associated circuitry. A post hoc analysis identified individual variability in the response to mCPP (exploratory responder-non-responder analysis). Some participants did not reduce their cookie intake after treatment with mCPP and this lack of response was associated with enhanced ratings of cookie pleasantness and enhanced baseline BOLD responses to food images in key reward and appetite circuitry. CONCLUSIONS: These results suggest that 5-HT2C receptor activation in humans inhibits food reward-related responding and that further investigation of stratification of responding to mCPP and other 5-HT2C receptor agonists is warranted
The metabolic basis of adolescent idiopathic scoliosis: 2011 report of the “metabolic” workgroup of the Fondation Yves Cotrel
OBJECTIVE: The purpose of this review is to elucidate the metabolic processes involved in the pathogenesis of adolescent idiopathic scoliosis (AIS) in light of research by the present authors as well as current literature. METHODS: Pathogenetic mechanism
A Comparative Neuroanatomical Study of the Red Nucleus of the Cat, Macaque and Human
BACKGROUND:The human red nucleus (Nr) is comparatively less well-studied than that of cats or monkeys. Given the functional importance of reticular and midbrain structures in control of movement and locomotion as well as from an evolutionary perspective, we investigated the nature and extent of any differences in Nr projections to the olivary complex in quadrupedal and bipedal species. Using neuroanatomical tract-tracing techniques we developed a "neural sheet" hypothesis allowing us to propose how rubro-olivary relations differ among the three species. METHODS AND FINDINGS:Wheat germ agglutinin-horseradish peroxidase staining supports findings that the cat's nucleus accessories medialis of Bechtrew (NB) projects mainly to the lateral bend of the principal olive. We clarified boundaries among nucleus of Darkschewitsch (ND), NB and parvicellular red nucleus (pNr) of the cat's neural sheet. The macaque's ND-medial accessory olivary projection is rostro-caudally organized and the dorsomedial and ventrolateral parts of the macaque's pNr may project to the principal olive's rostral and caudal dorsal lamella; in cat it projects as well to pNr. Myelin- and Nissl-stained sections show that a well-developed dorsomedial part of the human Nr consists of densely packed cells, deriving small myelinated fibers that continue into the medial central tegmental tract. CONCLUSIONS:Based on these findings we suggest there are distinct bipedal-quadrupedal differences for Nr projections to the olivary complex. We propose the Nr of cats and monkeys comprise the ND, NB and pNr in a zonal sheet-like structure, retaining clear nuclear boundaries and an isolated, well-developed mNr. The human NB may be distinguished from its more specialised ND (ND lies alongside a well-developed pNr) in the human central gray. Phylogenetically, the NB may have been translocated into a roll-shaped Nr in the reticular formation, the dorsomedial portion of which might correspond to the cat's and monkey's NB
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