111 research outputs found
CO<sub>2</sub> Levels Modulate Carbon Utilization, Energy Levels and Inositol Polyphosphate Profile in <i>Chlorella</i>
No full textMicroalgae have a growing recognition of generating biomass and capturing carbon in the form of CO2. The genus Chlorella has especially attracted scientists’ attention due to its versatility in algal mass cultivation systems and its potential in mitigating CO2. However, some aspects of how these green microorganisms respond to increasing concentrations of CO2 remain unclear. In this work, we analyzed Chlorella sorokiniana and Chlorella vulgaris cells under low and high CO2 levels. We monitored different processes related to carbon flux from photosynthetic capacity to carbon sinks. Our data indicate that high concentration of CO2 favors growth and photosynthetic capacity of the two Chlorella strains. Different metabolites related to the tricarboxylic acid cycle and ATP levels also increased under high CO2 concentrations in Chlorella sorokiniana, reaching up to two-fold compared to low CO2 conditions. The signaling molecules, inositol polyphosphates, that regulate photosynthetic capacity in green microalgae were also affected by the CO2 levels, showing a deep profile modification of the inositol polyphosphates that over-accumulated by up to 50% in high CO2 versus low CO2 conditions. InsP4 and InsP6 increased 3- and 0.8-fold, respectively, in Chlorella sorokiniana after being subjected to 5% CO2 condition. These data indicate that the availability of CO2 could control carbon flux from photosynthesis to carbon storage and impact cell signaling integration and energy levels in these green cells. The presented results support the importance of further investigating the connections between carbon assimilation and cell signaling by polyphosphate inositols in microalgae to optimize their biotechnological applications
Carotenoid deficiency triggers autophagy in the model green alga Chlamydomonas reinhardtii
No full textAll aerobic organisms have developed sophisticated mechanisms to prevent, detect and respond to cell damage caused by the unavoidable production of reactive oxygen species (ROS). Plants and algae are able to synthesize specific pigments in the chloroplast called carotenoids to prevent photo-oxidative damage caused by highly reactive by-products of photosynthesis. In this study we used the unicellular green alga Chlamydomonas reinhardtii to demonstrate that defects in carotenoid biosynthesis lead to the activation of autophagy, a membrane-trafficking process that participates in the recycling and degradation of damaged or toxic cellular components. Carotenoid depletion caused by either the mutation of phytoene synthase or the inhibition of phytoene desaturase by the herbicide norflurazon, resulted in a strong induction of autophagy. We found that high light transiently activates autophagy in wild-type Chlamydomonas cells as part of an adaptation response to this stress. Our results showed that a Chlamydomonas mutant defective in the synthesis of specific carotenoids that accumulate during high light stress exhibits constitutive autophagy. Moreover, inhibition of the ROS-generating NADPH oxidase partially reduced the autophagy induction associated to carotenoid deficiency, which revealed a link between photo-oxidative damage, ROS accumulation and autophagy activation in Chlamydomonas cells with a reduced carotenoid content.We thank the Chlamydomonas Center culture collection for providing Chlamydomonas strains and in particular to Krishna Niyogi and Arthur Grossman for making carotenoid mutant strains available to the research community. This work was supported by the Spanish Ministry of Science and Innovation (grant BFU2009-07368 to J.L.C.).Peer reviewe
Prevalence and associated factors of the use of opioids in the treatment of chronic non-cancer pain. Perspective of the general Spanish population and the experience of patients.
No full textAims
The general aim of this thesis was to study the situation of opioid treatments for chronic noncancer pain (CNCP). The specific aims were: first, to determine and synthesize the prevalence of
the therapeutic use of opioids in patients with CNCP, and to analyze the factors associated with
their use through a systematic review of the literature and a meta-analysis; second, to
investigate the evolution of opioid-related mortality and potential years of life lost in the general
population in Spain from 2008 to 2017 and to compare the results by gender and age with the
United States; third, to describe the current perspective of the Spanish population toward opioid
use in the treatment of pain and to identify groups of individuals based on their point of view
on these drugs; and finally, to explore the experiences of patients with chronic non-malignant
low back pain in Spain undergoing long-term treatment (>3 months) with opioids.
Methods
In the first study of the thesis, a systematic review of the current literature and meta-analysis
were performed using two databases (PubMed and SCOPUS). For this purpose, original crosssectional studies published in English or Spanish between 2009 and 2019 with the main objective
of determining the prevalence of opioid use in CNCP patients were included. Search terms and
search strategies were adapted to each database. The articles included in the meta-analysis
were stratified according to the source of the sample, the type of pain, and the duration of the
opioid treatment.
The second paper of the thesis is a descriptive study using retrospective annual data from 2008
to 2017 in the general population of Spain and the United States. Information on the population
and opioid-related deaths stratified by age and sex was obtained from the Spanish National
Statistics Institute and from the Centers for Disease Control and Prevention (CDC) WONDER
Multiple Cause of Death Database, according to the ICD-10 codes. Years of life lost, crude and
standardized mortality rates were calculated and compared with the results in US.
The third article included in the thesis is a cross-sectional study carried out on a nationwide
representative sample of 1,299 Spanish adults. Data and information about beliefs, knowledge,
fears, opinions and, attitudes towards the use of opioids were collected via a computer assisted
telephone interview (CATI). A descriptive analysis of the variables studied and a cluster analysis
were performed to identify groups of people based on these parameters. In addition, a
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ABSTRACT. 18
multinomial logistic regression model was developed to analyze the variables related to the
clusters.
Finally, in the last part of the thesis, a qualitative study was performed using semi-structured
interviews. Recruitment and data collection were conducted from April to October 2018. Fifteen
participants were recruited from the Pain Clinic in Hospital Puerta del Mar. Inclusion criteria for
the study were: adults suffering from chronic non-malignant low back pain and receiving longterm treatment (>3 months) with opioids. We conducted interviews until very similar
experiences were described in the last interviews as in the previous ones. A constructionist
perspective was adopted. The interviews were analyzed by the qualitative content method
described by Graneheim and Lundman, and developed categories and themes discussed in the
light biomedicalization theoretical framework.
Results
In the first article, we identified that of the 1062 potential articles found in the systematic
review, 23 studies fulfilled the inclusion criteria. In the general population, the prevalence of
long-term (>3 months) opioid use was 2.3% (95%CI:1.5%-3.6%), the prevalence of short-term
opioid use was 7.3% (95%CI:4.3%-11.9%), and 5.8% among people with chronic low back pain
(95% CI:0.5% - 45.5%). The prevalence of opioid use among patients from the health records or
medical surveys was 41% (95%CI:23.3%-61.3%). Finally, in patients with musculoskeletal pain,
the prevalence was 20.5% (95%CI:12.9%-30.9%) and 24.5% among patients with fibromyalgia
(95%CI:22.9%-26.2%). A higher prevalence of opioid use was observed among the following
groups: men; younger people; patients receiving prescriptions of different types of drugs;
smokers and patients without insurance or with non-commercial insurance. In addition, nonwhite and Asian patients were less likely to receive opioids than non-Hispanic white patients.
The results of the second study showed that the crude rate of opioid-related deaths per 10^5
inhabitants has changed from 1.68 in 2008 to 2.25 in 2017 in Spain, with around 30,000 years of
life lost per year. The most affected groups were middle-aged men and women over 65, and the
main cause of death was accidental poisoning. The standardized rates per 10^5 inhabitants
across the years were between 1.19 and 1.62 in Spain and between 11.17 and 20.68 in the US
population.
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ABSTRACT. 19
In the analysis of the beliefs, fears, opinions and attitude towards opioids analyzed in the third
article in the general Spanish population, three groups of subjects were identified: a group with
a positive point of view (N=448) composed of people >65 years who would accept a treatment
if prescribed and were less fearful of these drugs; a group with a moderate point of view (N=337)
formed of younger subjects with university education, and who were better informed about
opioids, afraid of these drugs (OR=2.67), and more frequently associated them with drowsiness
(OR=2.58), nausea (OR=3.04), and tolerance (OR=2.16); a third group with a negative point of
view (N=468), with a lower educational level who would more often reject treatment with
opioids, and were more afraid of them (OR=3.95), considering that they may not be able to stop
the treatment (OR=3.04) and that the opioids may produce tolerance (OR=3.03).
Finally, in the analysis of the experiences of people with chronic pain (CP) taking opioids,
described in the fourth article, we developed one overarching theme - living with opioids:
dependence and autonomy while seeking relief - which crosscut three categories: 1) The long
pathway to opioids due to the invisibility of pain, 2) Opioids: from blind date to a long-term
relationship and 3) What opioids cannot fix. The results show that the long and difficult process
to obtain effective treatment was a fundamental part of the struggle to cope with pain, involving
long-term relationships with the health system. The two first categories refer to the journey
participants made to get a diagnosis and treatment with opioids, and their experiences during
this long and difficult process, which was quite unique for each person. The third category
describes the circumstances and situations experienced by the patients before and after the
painful episode started, and how these influenced the whole process.
Conclusions
The results obtained in the different studies lead to the following conclusions:
- The prevalence of opioid use in patients with CNCP varies depending on the duration
of treatment and the population analyzed, with higher prevalence in clinical studies
based on health registries and occasional users. Age, race, and the access to the
health service delivery system and its characteristics are the factors most related to
the use of opioids.
- Regarding opioid-related mortality, an opioid overuse crisis does not seem a likely
scenario in Spain. However, it is a social problem that requires special health
surveillance, particularly in middle-aged men and women over 65.
20
ABSTRACT. 20
- The different perspectives of patients regarding the use of opioids to treat pain
should be taken into consideration by physicians when designing strategies to
inform patients about the treatment of pain with opioids. This should promote their
correct use, and prevent their misuse in particular.
- The experiences of patients should be considered to a greater extent by healthcare
professionals when giving information about opioids and setting treatment goals.
Greater consideration of the social determinants of health that affect chronic pain
experiences might lead to more effective solutions to chronic pain
Inositol polyphosphates regulate resilient mechanisms in the green alga Chlamydomonas reinhardtii to adapt to extreme nutrient conditions
No full textDATA AVAILABILITY STATEMENT
The raw and processed RNA-seq data that support the findings of this study are openly available in the Gene Expression Omnibus (https://www.ncbi.nlm.nih.gov/geo/) repository and can be accessed with the Identifier GSE276249. The raw RNA-seq data are openly available at the Sequence Read Archive (https://www.ncbi.nlm.nih.gov/sra) and can be accessed with the identifier PRJNA1156089. The raw and processed metabolomic data can be found in the MetaboLights repository (https://www.ebi.ac.uk/metabolights/) using the identifier MTBLS10779.In the context of climate changing environments, microalgae can be excellent organisms to understand molecular mechanisms that activate survival strategies under stress. Chlamydomonas reinhardtii signalling mutants are extremely useful to decipher which strategies photosynthetic organisms use to cope with changeable environments. The mutant vip1-1 has an altered profile of pyroinositol polyphosphates (PP-InsPs), which are signalling molecules present in all eukaryotes and have been connected to P signalling in other organisms including plants, but their implications in other nutrient signalling are still under evaluation. In this study, we conducted prolonged starvation in WT and vip1-1 Chlamydomonas cells. After N and P had been consumed, they showed important differences in the levels of chlorophyll, photosystem II (PSII) activity and ultrastructural morphology, including differences in the cell size and cell division. Metabolomic analysis under these conditions revealed an overall decrease in different organic compounds such as amino acids, including arginine and its precursors and tryptophan, which is considered a signalling molecule itself in plants. In addition, we observed significant differences in RNA levels of genes related to N assimilation that are under the control of the NIT2 transcription factor. These data are of important relevance in understanding the signalling role of PP-InsPs in nutrient sensing, especially regarding N, which has not directly been connected to these molecules in green organisms before. Additionally, the PP-InsPs regulation over cell size and photosynthesis supports novel strategies for the generation of resilient strains, expanding the biotechnological applications of green microalgae.Ministerio de Ciencia, Innovación y Universidades, Grant/Award Number: FPU22/00688
RBG was also awarded as a FPU22/00688 fellow by Ministerio de Educación.Peer reviewe
Estudio y manipulación genética de la ruta de carotenoides en "Chlamydomonas Reinhardtii" mediante la expresión de genes exógenos
No full textLos carotenoides son un grupo de pigmentos isoprenoides sintetizados por todos los
organismos fotosintéticos y algunas bacterias y hongos. Los animales y otros
organismos que no los producen in vivo deben incluirlos en su dieta ya que, por
ejemplo, son responsables de la coloración del plumaje y de algunas aves y precursores
de compuestos esenciales como la vitamina A. Además, su capacidad antioxidante y
sus aplicaciones nutraceúticas les hacen ser productos de una alta importancia
económica.
La manipulación genética de la microalga Chlamydomonas reinhardtii es la principal
herramienta en el que se basa este trabajo. Mediante la expresión de genes exógenos,
pretendemos incrementar el contenido en carotenoides y obtener un conocimiento más
profundo de las enzimas involucradas en esta ruta y su regulación in vivo. Además,
diferentes condiciones de estrés ambiental han sido utilizadas para clarificar la
respuesta funcional de esta ruta en esta clorofita.Carotenoids are a wide group of lipophylic isoprenoid compounds synthesised by all
photosynthetic organisms and also by sorne non photosynthetic bacteria and fungi. This
is the reason why animals and other organisms that do not synthesise them de novo
must include them in their diet to acquire their characteristic colours or as precursors
for essential compounds. Carotenoids have been described as indispensable in light collection and energy transmission during photosynthesis and their antioxidant capacity
and applications in nutraceuticals andas feed additives make them be ofhigh
economical valuable products.
The genetic manipulation ofthe microalga Chlamydomonas reinhardtii is the principal
tool on the basis ofthis work. By means ofthe exogenous gene expression, we expect
to in crease the carotenoid content and obtain a deep understanding of the enzymes
involved in the pathway and its in vivo regulation. Also, different environmental
conditions have been used to clarify the functional response of the route in this
microalga.Química "Profesor José Carlos Vílchez Martín
Prevalence of Migraine in General Spanish Population; Factors Related and Use of Health Resources
No full textMigraine is a common neurological disorder considered the second most disabling condition worldwide. Its prevalence ranges from 2.6% to 21.7% in population studies. This study aimed to know the prevalence of diagnosed and undiagnosed migraine in the general Spanish adult population, their health care use, and factors related. A descriptive cross-sectional study was undertaken with 23,089 individuals >15 years from the 2017 Spanish National Health Survey. Three groups were defined: people diagnosed with migraine (DM), people reporting undiagnosed migraine (UM) and people without migraine. Sociodemographic, clinical and use of health resources data were collected. The scales Duke Social Support Index (DSSI) and General Health Questionnaire (GHQ-12) were used. Prevalence of DM and UM were determined with 95% confidence intervals. To determine the factors associated with DM and UM, a multinomial logistic regression model was used. The prevalence of DM was 8.6% (95%CI: 8.2–9), and UM, 0.9% (95%CI: 0.8–1). People with DM more frequently visited healthcare professionals (47.8%), required more supplementary tests (86.8), had a higher percentage of hospitalization (11.3%), and used emergency services (45.1%). Women had nearly three times the risk of DM and UM. Worse mental health was a risk factor for UM (OR = 1.20) and DM (OR = 1.18). The greater the work stress, the greater the risk of DM (OR = 1.12). An adequate monitoring and management of migraine in people with these characteristics could contribute to improving their quality of life and reducing costs in the system
Synthesis of carotenoids and regulation of the carotenoid biosynthesis pathway in response to high light stress in the unicellular microalga Chlamydomonas reinhardtii
No full textThe carotenoid biosynthesis pathway catalyses the synthesis of essential pigments that are crucial for light harvesting and photoprotection in photosynthetic organisms. It allows the production of several commercially important compounds and is the target of many herbicides. In the present work we studied the influence of light on the carotenoid composition and the expression of genes encoding the main steps of the pathway in the freshwater microalga Chlamydomonas reinhardtii. We observed that there is an activation of the xanthophyll cycle in response to high light, but also in response to other stress conditions, such as nitrogen starvation, which has not been reported previously. We analysed the expression level of (1) genes encoding the two first enzymes of the pathway, phytoene synthase and phytoene desaturase; (2) the enzymes responsible for the cyclization of lycopene, lycopene β-cyclase and lycopene ε-cyclase; (3) zeaxanthin epoxidase, which catalyses the epoxidation of zeaxanthin; and (4) the three known carotene hydroxylases, directly involved in the synthesis of xanthophylls from α and β-carotene. Measurements of carotenoid content in the presence of inhibitors of protein and carotenoid synthesis suggest that only one of the two possible routes for the synthesis of zeaxanthin upon transference to high light, either the de novo synthesis of carotenoids or the interconversion of violaxanthin and zeaxanthin, is dependent on protein synthesis. The high increase in the transcript levels of the cytochrome-dependent carotene β- and ε-hydroxylases in response to high light suggests an important role of these enzymes in regulation of xanthophyll synthesis upon light stress. These conclusions may be of high interest if efficient engineering of the pathway is to be accomplished. © 2012 Copyright Taylor and Francis Group, LLC.We thank the Andalusian government for financial support (P09-CVI-5053).Peer reviewe
Autophagic flux is required for the synthesis of triacylglycerols and ribosomal protein turnover in Chlamydomonas
No full textAutophagy is an intracellular catabolic process that allows cells to recycle unneeded or damaged material to maintain
cellular homeostasis. This highly dynamic process is characterized by the formation of double-membrane vesicles
called autophagosomes, which engulf and deliver the cargo to the vacuole. Flow of material through the autophagy
pathway and its degradation in the vacuole is known as autophagic flux, and reflects the autophagic degradation
activity. A number of assays have been developed to determine autophagic flux in yeasts, mammals, and plants, but
it has not been examined yet in algae. Here we analyzed autophagic flux in the model green alga Chlamydomonas
reinhardtii. By monitoring specific autophagy markers such as ATG8 lipidation and using immunofluorescence and
electron microscopy techniques, we show that concanamycin A, a vacuolar ATPase inhibitor, blocks autophagic flux
in Chlamydomonas. Our results revealed that vacuolar lytic function is needed for the synthesis of triacylglycerols
and the formation of lipid bodies in nitrogen- or phosphate-starved cells. Moreover, we found that concanamycin
A treatment prevented the degradation of ribosomal proteins RPS6 and RPL37 under nitrogen or phosphate deprivation.
These results indicate that autophagy might play an important role in the regulation of lipid metabolism and the
recycling of ribosomal proteins under nutrient limitation in ChlamydomonasPeer reviewe
Hitos y retos en la biofortificación de cassava.
No full textLa cassava es uno de los pilares fundamentales de la dieta en muchos países tropicales, especialmente en países del tercer mundo, pues es un cultivo muy productivo y que supone un gran aporte de energía. A pesar de esto, es un cultivo con un valor nutricional pobre, con un contenido bajo en proteínas y algunos minerales y vitaminas, y del que además depende la seguridad alimentaria de muchos países. Todo esto hace que la cassava sea una planta en estudio para desarrollar estrategias de biofortificación que pasan por la modificación genética del cultivo. En este trabajo se recogen las principales aproximaciones que se han realizado al respecto, desde la mejora de su calidad nutricional, su resistencia a estrés biótico y la eliminación de compuestos tóxicos potencialmente nocivos para los consumidores. También se detallan las perspectivas de estas investigaciones en un futuro próximo para mejorar tanto el consumo como la seguridad de este cultivo.Universidad de Sevilla y Málaga. Grado en Bioquímic
Regulación de la biosíntesis de carotenoides mediada por inositoles polifosfato
No full textLos carotenoides son compuestos orgánicos de creciente interés biotecnológico, y en este sentido las microalgas son candidatas muy interesantes para su producción, pero los mecanismos que controlan la regulación de la biosíntesis de carotenoides no se han elucidado todavía completamente. Por otro lado, a los inositoles polifosfato se les ha atribuído recientemente un papel en la partición del carbono en Chlamydomonas reinhardtii1. En nuestros estudios empleamos el mutante vip1-1, deficiente en inositoles polifosfato, para investigar la posible implicación de estas moléculas en la regulación de la biosíntesis de carotenoides. De esta forma, detectamos una activación del ciclo de las xantofilas, que puede bien ser producto de la modulación directa de los inositoles polifosfato o bien estar provocado indirectamente por un mayor estrés oxidativo. Además, nuestros resultados sugieren que la ruta de las pentosas fosfato y en el ciclo de Krebs podrían ser nuevas dianas de la modulación ejercida por estas moléculas, lo que resultaría de interés para una supuesta ingeniería metabólica. Por tanto, este trabajo propone nuevas dianas de los inositoles polifosfato, que podrán ser investigadas en profundidad en estudios venideros.The carotenoides are organic compounds of growing biotechnological interest, and the microalgae are interesting candidates for its production, but the mechanisms that govern the biosynthesys of carotenoids remain uncompletely elucidated yet. On the other hand, inositol polyphosphates have recently been assigned a function in carbon partitioning in Chlamydomonas reinhardtii. In our studies we used the mutant vip1-1, defficient in inositol polyphosphates, to investigate the implication these molecules might have in carotenoids biosynthesis. This way, we detected an activation of the xanthophyll cycle, which might be product of direct modulation performed by inositol polyphosphates, or might be caused indirectly by oxidative stress. Furthermore, our findings suggested the Krebs cycle and the pentoses phosphate cycle might be new targets of the inositol polyphosphates modulation, which could be of interest regarding a potential metabolic engineering. Therefore, this work proposes new targets of the inositol polyphosphates which could be further investigated in forthcoming studies.Universidad de Sevilla y Málaga. Grado en Bioquímic
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