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18
result(s) for
"Xifra, Gemma"
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Molecular phenomics and metagenomics of hepatic steatosis in non-diabetic obese women
by
Abbott, James
,
Butcher, Sarah A.
,
Fernández-Real, José-Manuel
in
631/1647/2017/2079
,
631/326/2565/2134
,
631/45/320
2018
Hepatic steatosis is a multifactorial condition that is often observed in obese patients and is a prelude to non-alcoholic fatty liver disease. Here, we combine shotgun sequencing of fecal metagenomes with molecular phenomics (hepatic transcriptome and plasma and urine metabolomes) in two well-characterized cohorts of morbidly obese women recruited to the FLORINASH study. We reveal molecular networks linking the gut microbiome and the host phenome to hepatic steatosis. Patients with steatosis have low microbial gene richness and increased genetic potential for the processing of dietary lipids and endotoxin biosynthesis (notably from Proteobacteria), hepatic inflammation and dysregulation of aromatic and branched-chain amino acid metabolism. We demonstrated that fecal microbiota transplants and chronic treatment with phenylacetic acid, a microbial product of aromatic amino acid metabolism, successfully trigger steatosis and branched-chain amino acid metabolism. Molecular phenomic signatures were predictive (area under the curve = 87%) and consistent with the gut microbiome having an effect on the steatosis phenome (>75% shared variation) and, therefore, actionable via microbiome-based therapies.
Metabolic activity of specific human gut microorganisms contributes to liver steatosis in obese women.
Journal Article
Obesity changes the human gut mycobiome
2015
The human intestine is home to a diverse range of bacterial and fungal species, forming an ecological community that contributes to normal physiology and disease susceptibility. Here, the fungal microbiota (mycobiome) in obese and non-obese subjects was characterized using Internal Transcribed Spacer (ITS)-based sequencing. The results demonstrate that obese patients could be discriminated by their specific fungal composition, which also distinguished metabolically “healthy” from “unhealthy” obesity. Clusters according to genus abundance co-segregated with body fatness, fasting triglycerides and HDL-cholesterol. A preliminary link to metabolites such as hexadecanedioic acid, caproic acid and N-acetyl-L-glutamic acid was also found.
Mucor racemosus
and
M. fuscus
were the species more represented in non-obese subjects compared to obese counterparts. Interestingly, the decreased relative abundance of the
Mucor
genus in obese subjects was reversible upon weight loss. Collectively, these findings suggest that manipulation of gut mycobiome communities might be a novel target in the treatment of obesity.
Journal Article
Unseen threat: how subclinical atherosclerosis increases mortality risk in patients with type 1 diabetes
2024
Background
Cardiovascular disease (CVD), particularly ischemic heart disease, remains the leading cause of death and morbidity in patients with type 1 diabetes. Detecting subclinical atherosclerosis could enhance cardiovascular risk stratification and enable individualised therapies. The aim of this study is to investigate the prevalence and predictors of subclinical atherosclerosis in patients with type 1 diabetes without overt cardiovascular disease (CVD) and to assess its impact on patient survival over a follow-up period of at least 5 years.
Methods
This observational study included 507 patients treated at the Diabetes Unit of the Hospital of Girona Doctor Josep Trueta between 2015 and 2023. The inclusion criteria for patients were as follows: those aged 18 and older with diabetes for a minimum of 10 years or those aged 40 and older with a diabetes for at least 5 years. Subclinical atherosclerosis was identified via ultrasound imaging of the carotid and femoral arteries. Clinical and biochemical evaluations were also conducted. Major cardiovascular events (MACE) and deaths from other causes were monitored, and survival analysis was performed using Kaplan‒Meier methods.
Results
Subclinical atherosclerosis was detected in 218 patients (43%). Multivariate analysis revealed that the male sex, diabetic nephropathy, tobacco exposure, higher HbA1c levels, older age, and longer diabetes duration were significant predictors. During a mean follow-up of 70.64 ± 27.08 months, 19 patients experienced MACE, and 13 died from any cause. The probability of MACE or death was greater in patients with subclinical atherosclerosis, with a hazard ratio (HR) of 25.1 (95% CI 5.81–108,
p
< 0.001) for MACE and an odds ratio (OR) of 7.57 (95% CI 1.97–53.9,
p
= 0.004) for death.
Conclusion
Subclinical atherosclerosis is independently associated with increased overall mortality and MACE in patients with type 1 diabetes. Identifying clinical predictors can improve risk stratification and personalised therapeutic strategies to prevent MACEs in this high-risk population.
Graphical Abstract
Journal Article
Iron and Obesity Status-Associated Insulin Resistance Influence Circulating Fibroblast-Growth Factor-23 Concentrations
by
Moreno-Navarrete, José María
,
Salvador, Javier
,
Frühbeck, Gema
in
Adipose tissue
,
Adult
,
Arteriosclerosis
2013
Fibroblast growth factor 23 (FGF-23) is known to be produced by the bone and linked to metabolic risk. We aimed to explore circulating FGF-23 in association with fatness and insulin sensitivity, atherosclerosis and bone mineral density (BMD). Circulating intact FGF-23 (iFGF-23) and C-terminal (CtFGF-23) concentrations (ELISA) were measured in 133 middle aged men from the general population in association with insulin sensitivity (Cohort 1); and in association with fat mass and bone mineral density (DEXA) and atherosclerosis (intima media thickness, IMT) in 78 subjects (52 women) with a wide range of adiposity (Cohort 2). Circulating iFGF-23 was also measured before and after weight loss. In all subjects as a whole, serum intact and C-terminal concentrations were linearly and positively associated with BMI. In cohort 1, both serum iFGF-23 and CtFGF-23 concentrations increased with insulin resistance. Serum creatinine contributed to iFGF-23 variance, while serum ferritin and insulin sensitivity (but not BMI, age or serum creatinine) contributed to 17% of CtFGF-23 variance. In cohort 2, CtFGF-23 levels were higher in women vs. men, and increased with BMI, fat mass, fasting and post-load serum glucose, insulin, HOMA-IR and PTH, being negatively associated with circulating vitamin D and ferritin levels. The associations of CtFGF-23 with bone density in the radius, lumbar spine and carotid IMT were no longer significant after controlling for BMI. Weight loss led to decreased iFGF-23 concentrations. In summary, the associations of circulating FGF-23 concentration with parameters of glucose metabolism, bone density and atherosclerosis are dependent on iron and obesity status-associated insulin resistance.
Journal Article
A role for adipocyte-derived lipopolysaccharide-binding protein in inflammation- and obesity-associated adipose tissue dysfunction
by
Giralt, Marta
,
Moreno-Navarrete, José María
,
Laville, Martine
in
Biological and medical sciences
,
Diabetes. Impaired glucose tolerance
,
Endocrine pancreas. Apud cells (diseases)
2013
Journal Article
Metformin alters the gut microbiome of individuals with treatment-naive type 2 diabetes, contributing to the therapeutic effects of the drug
by
Khan, Muhammad Tanweer
,
Olsson, Lisa M
,
Mercader, Josep M
in
45/23
,
631/326/2565
,
631/443/319
2017
A randomized clinical trial reveals that the antidiabetic effects of metformin are at least partially due to beneficial changes in the microbiota.
Metformin is widely used in the treatment of type 2 diabetes (T2D), but its mechanism of action is poorly defined. Recent evidence implicates the gut microbiota as a site of metformin action. In a double-blind study, we randomized individuals with treatment-naive T2D to placebo or metformin for 4 months and showed that metformin had strong effects on the gut microbiome. These results were verified in a subset of the placebo group that switched to metformin 6 months after the start of the trial. Transfer of fecal samples (obtained before and 4 months after treatment) from metformin-treated donors to germ-free mice showed that glucose tolerance was improved in mice that received metformin-altered microbiota. By directly investigating metformin–microbiota interactions in a gut simulator, we showed that metformin affected pathways with common biological functions in species from two different phyla, and many of the metformin-regulated genes in these species encoded metalloproteins or metal transporters. Our findings provide support for the notion that altered gut microbiota mediates some of metformin's antidiabetic effects.
Journal Article
Personalized Medicine in Acromegaly: The ACROFAST Study
by
Gil, Joan
,
Blanco, Concepción
,
de Miguel, Paz
in
Acromegaly
,
Acromegaly - diagnosis
,
Acromegaly - drug therapy
2024
Abstract
Context
Medical treatment of acromegaly is currently performed through a trial-and-error approach using first-generation somatostatin receptor ligands (fgSRLs) as first-line drugs, with an effectiveness of about 50%, and subsequent drugs are indicated through clinical judgment. Some biomarkers can predict fgSRLs response.
Objective
Here we report the results of the ACROFAST study, a clinical trial in which a protocol based on predictive biomarkers of fgSRLs was evaluated.
Methods
This was a prospective trial (21 university hospitals) comparing the effectiveness and time-to-control of 2 treatment protocols during 12 months: (A) a personalized protocol in which the first options were fgSRLs as monotherapy or in combination with pegvisomant, or pegvisomant as monotherapy depending on the short acute octreotide test (sAOT) results, tumor T2 magnetic resonance (MRI) signal or immunostaining for E-cadherin; and (B) a control group with treatment always started by fgSRLs and the other drugs included after demonstrating inadequate control.
Results
Eighty-five patients participated; 45 in the personalized and 40 in the control group. More patients in the personalized protocol achieved hormonal control compared to those in the control group (78% vs 53%, P < .05). Survival analysis revealed a hazard ratio for achieving hormonal control adjusted by age and sex of 2.53 (CI, 1.30-4.80). Patients from the personalized arm were controlled in a shorter period of time (P = .01).
Conclusion
Personalized medicine is feasible using a relatively simple protocol, and it allows a higher number of patients to achieve control in a shorter period of time.
Journal Article
Metabolomics uncovers the role of adipose tissue PDXK in adipogenesis and systemic insulin sensitivity
by
Portero-Otin, Manuel
,
Moreno-Navarrete, José María
,
Pamplona, Reinald
in
3T3-L1 Cells
,
Adipocytes
,
Adipocytes - metabolism
2016
Aims/hypothesis
We aimed to investigate the potential mechanisms involved in the compromised adipogenesis of visceral (VAT) vs subcutaneous adipose tissue (SAT) using comparative metabolomics. Based on the differentially identified metabolites, we focused on the relationship between the active form of vitamin B
6
(pyridoxal 5-phosphate [PLP]), known to be generated through pyridoxal kinase (PDXK), and adipogenesis.
Methods
Non-targeted metabolomics analyses were performed in paired VAT and SAT (
n
= 14, discovery cohort).
PDXK
gene expression was evaluated in two validation cohorts of paired SAT and VAT samples in relation to obesity status and insulin sensitivity, and mechanistically after weight loss in vivo and in 3T3-L1 cells in vitro.
Results
Comparative metabolomics showed that PLP was significantly decreased in VAT vs SAT. Concordantly,
PDXK
mRNA levels were significantly decreased in VAT vs SAT, specifically in adipocytes. The decrease was specially marked in obese individuals.
PDXK
mRNA levels showed a strong association with adipogenic, lipid-droplet-related and lipogenic genes. At a functional level, systemic insulin sensitivity positively associated with
PDXK
expression, and surgically-induced weight loss (improving insulin sensitivity) led to increased SAT
PDXK
mRNA levels in parallel with adipogenic genes. In human pre-adipocytes,
PDXK
mRNA levels increased during adipocyte differentiation and after administration of peroxisome proliferator-activated receptor-γ agonists, and decreased under inflammatory stimuli. Mechanistic studies in 3T3-L1 cells showed that PLP administration resulted in increased adipogenic mRNA markers during early adipogenesis, whereas the PLP antagonist 4-deoxypyridoxine exerted opposite effects.
Conclusions/interpretation
Overall, these results support the notion that in situ production of PLP is required for physiological adipogenesis.
Journal Article
A role for adipocyte-derived lipopolysaccharide-binding protein in inflammation- and obesity-associated adipose tissue dysfunction
by
Giralt, Marta
,
Moreno-Navarrete, José María
,
Laville, Martine
in
Acute-Phase Proteins - metabolism
,
Adipocytes
,
Adipocytes - metabolism
2013
Aims/hypothesis
Circulating lipopolysaccharide-binding protein (LBP) is an acute-phase reactant known to be increased in obesity. We hypothesised that LBP is produced by adipose tissue (AT) in association with obesity.
Methods
LBP
mRNA and LBP protein levels were analysed in AT from three cross-sectional (
n
= 210,
n
= 144 and
n
= 28) and three longitudinal (
n
= 8,
n
= 25,
n
= 20) human cohorts; in AT from genetically manipulated mice; in isolated adipocytes; and in human and murine cell lines. The effects of a high-fat diet and exposure to lipopolysaccharide (LPS) and peroxisome proliferator-activated receptor (PPAR)γ agonist were explored. Functional in vitro and ex vivo experiments were also performed.
Results
LBP synthesis and release was demonstrated to increase with adipocyte differentiation in human and mouse AT, isolated adipocytes and human and mouse cell lines (Simpson–Golabi–Behmel syndrome [SGBS], human multipotent adipose-derived stem [hMAD] and 3T3-L1 cells). AT LBP expression was robustly associated with inflammatory markers and increased with metabolic deterioration and insulin resistance in two independent cross-sectional human cohorts. AT LBP also increased longitudinally with weight gain and excessive fat accretion in both humans and mice, and decreased with weight loss (in two other independent cohorts), in humans with acquired lipodystrophy, and after ex vivo exposure to PPARγ agonist. Inflammatory agents such as LPS and TNF-α led to increased AT LBP expression in vivo in mice and in vitro, while this effect was prevented in
Cd14
-knockout mice. Functionally, LBP knockdown using short hairpin (sh)RNA or anti-LBP antibody led to increases in markers of adipogenesis and decreased adipocyte inflammation in human adipocytes.
Conclusions/interpretation
Collectively, these findings suggest that LBP might have an essential role in inflammation- and obesity-associated AT dysfunction.
Journal Article
Publisher Correction: Molecular phenomics and metagenomics of hepatic steatosis in non-diabetic obese women
by
Abbott, James
,
Butcher, Sarah A.
,
Fernández-Real, José-Manuel
in
631/1647/2017/2079
,
631/326/2565/2134
,
631/45/320
2018
In the version of this article originally published, the received date was missing. It should have been listed as 2 January 2018. The error has been corrected in the HTML and PDF versions of this article.
Journal Article