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"Baltar, Javier"
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Vesicles Shed by Pathological Murine Adipocytes Spread Pathology: Characterization and Functional Role of Insulin Resistant/Hypertrophied Adiposomes
2020
Extracellular vesicles (EVs) have recently emerged as a relevant way of cell to cell communication, and its analysis has become an indirect approach to assess the cell/tissue of origin status. However, the knowledge about their nature and role on metabolic diseases is still very scarce. We have established an insulin resistant (IR) and two lipid (palmitic/oleic) hypertrophied adipocyte cell models to isolate EVs to perform a protein cargo qualitative and quantitative Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH) analysis by mass spectrometry. Our results show a high proportion of obesity and IR-related proteins in pathological EVs; thus, we propose a panel of potential obese adipose tissue EV-biomarkers. Among those, lipid hypertrophied vesicles are characterized by ceruloplasmin, mimecan, and perilipin 1 adipokines, and those from the IR by the striking presence of the adiposity and IR related transforming growth factor-beta-induced protein ig-h3 (TFGBI). Interestingly, functional assays show that IR and hypertrophied adipocytes induce differentiation/hypertrophy and IR in healthy adipocytes through secreted EVs. Finally, we demonstrate that lipid atrophied adipocytes shed EVs promote macrophage inflammation by stimulating IL-6 and TNFα expression. Thus, we conclude that pathological adipocytes release vesicles containing representative protein cargo of the cell of origin that are able to induce metabolic alterations on healthy cells probably exacerbating the disease once established.
Journal Article
FNDC5/Irisin Is Not Only a Myokine but Also an Adipokine
by
Baltar, Javier
,
Castelao, Cecilia
,
Senin, Lucía L.
in
3T3-L1 Cells
,
Adipokines - metabolism
,
Adipose tissue
2013
Exercise provides clear beneficial effects for the prevention of numerous diseases. However, many of the molecular events responsible for the curative and protective role of exercise remain elusive. The recent discovery of FNDC5/irisin protein that is liberated by muscle tissue in response to exercise might be an important finding with regard to this unsolved mechanism. The most striking aspect of this myokine is its alleged capacity to drive brown-fat development of white fat and thermogenesis. However, the nature and secretion form of this new protein is controversial. The present study reveals that rat skeletal muscle secretes a 25 kDa form of FNDC5, while the 12 kDa/irisin theoretical peptide was not detected. More importantly, this study is the first to reveal that white adipose tissue (WAT) also secretes FNDC5; hence, it may also behave as an adipokine. Our data using rat adipose tissue explants secretomes proves that visceral adipose tissue (VAT), and especially subcutaneous adipose tissue (SAT), express and secrete FNDC5. We also show that short-term periods of endurance exercise training induced FNDC5 secretion by SAT and VAT. Moreover, we observed that WAT significantly reduced FNDC5 secretion in fasting animals. Interestingly, WAT of obese animals over-secreted this hormone, which might suggest a type of resistance. Because 72% of circulating FNDC5/irisin was previously attributed to muscle secretion, our findings suggest a muscle-adipose tissue crosstalk through a regulatory feedback mechanism.
Journal Article
Hepatic Olfr734 Deficiency Worsens Hepatic Glucose Metabolism and Induces MASLD in Mice
2025
Background/Objectives: Asprosin is the endogenous ligand of the olfactory Olfr734 receptor linked to MASLD and glucose metabolism. Despite the involvement of asprosin in these processes, little has been published on the specific role of Olfr734 in liver function. The aim of this work is therefore to study the specific role of the olfactory Olfr734 receptor in MASLD and glucose metabolism. Methods: To achieve this objective, we performed a genetic inhibition specifically to inhibit Olfr734 in the livers of male mice. We then studied the progression of MASLD in DIO mice. In addition, we studied the glucose metabolism in hypoglycemia states and postprandial glucose production in standard diet-fed mice. Finally, analyses of liver biopsies from patients with obesity and with or without T2DM were conducted. Results: We found that hepatic Olfr734 levels vary according to changes in nutritional status and its knockdown effect in the liver is to increase the hepatic lipid content in DIO mice. Our results also showed that OLFR734 expression is involved in the adaptive response in terms of glucose production to nutrient availability. Finally, the hepatic human Olfr734 ortholog named OR4M1 has been observed to be at significantly higher levels in male patients with T2DM. Conclusions: This study increases understanding of the mechanisms by which the modulation of Olfr734 expression affects liver function.
Journal Article
CILAIR-Based Secretome Analysis of Obese Visceral and Subcutaneous Adipose Tissues Reveals Distinctive ECM Remodeling and Inflammation Mediators
2015
In the context of obesity, strong evidences support a distinctive pathological contribution of adipose tissue depending on its anatomical site of accumulation. Therefore, subcutaneous adipose tissue (SAT) has been lately considered metabolically benign compared to visceral fat (VAT), whose location is associated to the risk of developing cardiovascular disease, insulin resistance and other associated comorbidities. Under the above situation, the chronic local inflammation that characterizes obese adipose tissue, has acquired a major role on the pathogenesis of obesity. In this work, we have analyzed for the first time human obese VAT and SAT secretomes using an improved quantitative proteomic approach for the study of tissue secretomes, Comparison of Isotope-Labeled Amino acid Incorporation Rates (CILAIR). The use of double isotope-labeling-CILAIR approach to analyze VAT and SAT secretomes allowed the identification of location-specific secreted proteins and its differential secretion. Additionally to the very high percentage of identified proteins previously implicated in obesity or in its comorbidities, this approach was revealed as a useful tool for the study of the obese adipose tissue microenvironment including extracellular matrix (ECM) remodeling and inflammatory status. The results herein presented reinforce the fact that VAT and SAT depots have distinct features and contribute differentially to metabolic disease.
Journal Article
Conversion from Duodenal Switch to Single Anastomosis Duodenal Switch to Deal with Postoperative Malnutrition
by
Bárcena María
,
Martis-Sueiro Aurelio
,
Crujeiras, Ana B
in
Alcohol abuse
,
Liver failure
,
Malnutrition
2021
BackgroundDuodenal switch (DS) is considered one of the most effective bariatric techniques for long-term weight and comorbidity control. After these operations, some patients may get severe complications related to malnutrition and a few of them may need surgical revision. Lengthening the common channel (CC) is usually the solution: changing the Roux anastomosis or with a side-to-side anastomosis (kissing X). We propose that when simplified construction of the DS is used, conversion to single anastomosis DS (SADI-S/OADS) is an easy and safe choice.ObjectivesTo evaluate the safety and effectiveness of conversion from DS to SADI-S in cases of malnutrition.MethodsWe report three patients with severe malnutrition after a DS at 9, 74, and 84 months. One of them had also liver failure related to alcohol abuse and malnutrition. Laparoscopic reoperations included a new ileo-ileal anastomosis and takedown of the Roux-en-Y anastomosis with the aim of lengthening the CC.ResultsAll three patients were successfully converted by laparoscopy. After a median follow-up of 54.6 months [32–76 months], all of them had moderate weight regain and returned to normal biochemical nutritional parameters. Two patients with type 2 diabetes (T2DM) before DS had complete remission before conversion; one of them had recurrence of T2DM after conversion. The patient with liver failure improved significantly after conversion.ConclusionsConversion from DS to SADI-S/OADS is a simple operation with excellent results in resolving malnutrition in those patients. However, weight regain and recurrence of comorbidities may arise.
Journal Article
Seeking an Initial-Weight-Independent Metric in a Mediterranean Cohort of Gastric Bypass Patients: the %AWL Revisited
by
Fàtima, Sabench Pereferrer
,
Sorribas Grifell María
,
Martín García-Almenta Ester
in
Gastrointestinal surgery
2021
BackgroundMost relative weight-loss metrics follow the formula “Weight loss(%) = 100 · (Initial BMI - Final BMI) / (Initial BMI-a),” where a is the reference point that defines the metric. The percentage of total weight loss (%TWL, a = 0) and percentage of excess weight loss (%EWL, a = 25) are influenced by a patient’s initial weight. Recently, the percentage of alterable weight loss metric (%AWL, a = 13) has been reported to produce initial-weight-independent outcomes.ObjectivesThis study aimed to replicate the methodology used for %AWL determination in a Mediterranean cohort of bariatric patients.SettingsMulticenter study in 10 large hospitals in Spain.MethodsTwo large prospective databases were retrospectively searched for all primary laparoscopic gastric bypass patients with 2 years of follow-up. Outcomes at nadir were expressed and analyzed with 26 different metrics (a from 0 to 25), looking for the metric whose outcomes produced (1) the lowest coefficient of variation, (2) no differences between initially lighter and heavier patients, and (3) no correlation with patients’ initial BMI.ResultsA cohort of 1793 patients was stratified into 4 gender-age groups: younger women (YW, n = 733), older women (OW, n = 674), younger men (YM, n = 197), and older men (OM, n = 189). The calculations suggested an optimal reference point of 18 kg/m2, defining a new metric (percentage of Mediterranean alterable weight loss, %MAWL). When %TWL, %EWL, %AWL, and %MAWL were tested on the whole sample, only %MAWL produced initial-weight-independent results.ConclusionsIn our Mediterranean cohort of patients, a reference point of 18 (and not 13) yielded initial-weight-independent outcomes.
Journal Article
Deciphering Adipose Tissue Extracellular Vesicles Protein Cargo and Its Role in Obesity
by
Baltar, Javier
,
Martis-Sueiro, Aurelio
,
Couto, Iván
in
Adipocytes
,
Adipose Tissue - metabolism
,
Animals
2020
The extracellular vesicles (EVs) have emerged as key players in metabolic disorders rising as an alternative way of paracrine/endocrine communication. In particular, in relation to adipose tissue (AT) secreted EVs, the current knowledge about its composition and function is still very limited. Nevertheless, those vesicles have been lately suggested as key players in AT communication at local level, and also with other metabolic peripheral and central organs participating in physiological homoeostasis, and also contributing to the metabolic deregulation related to obesity, diabetes, and associated comorbidities. The aim of this review is to summarize the most relevant data around the EVs secreted by adipose tissue, and especially in the context of obesity, focusing in its protein cargo. The description of the most frequent proteins identified in EVs shed by AT and its components, including their changes under pathological status, will give the reader a whole picture about the membrane/antigens, and intracellular proteins known so far, in an attempt to elucidate functional roles, and also suggesting biomarkers and new paths of therapeutic action.
Journal Article
Brown Adipose Tissue Sheds Extracellular Vesicles That Carry Potential Biomarkers of Metabolic and Thermogenesis Activity Which Are Affected by High Fat Diet Intervention
2022
Brown adipose tissue (BAT) is a key target for the development of new therapies against obesity due to its role in promoting energy expenditure; BAT secretory capacity is emerging as an important contributor to systemic effects, in which BAT extracellular vesicles (EVs) (i.e., batosomes) might be protagonists. EVs have emerged as a relevant cellular communication system and carriers of disease biomarkers. Therefore, characterization of the protein cargo of batosomes might reveal their potential as biomarkers of the metabolic activity of BAT. In this study, we are the first to isolate batosomes from lean and obese Sprague–Dawley rats, and to establish reference proteome maps. An LC-SWATH/MS analysis was also performed for comparisons with EVs secreted by white adipose tissue (subcutaneous and visceral WAT), and it showed that 60% of proteins were exclusive to BAT EVs. Precisely, batosomes of lean animals contain proteins associated with mitochondria, lipid metabolism, the electron transport chain, and the beta-oxidation pathway, and their protein cargo profile is dramatically affected by high fat diet (HFD) intervention. Thus, in obesity, batosomes are enriched with proteins involved in signal transduction, cell communication, the immune response, inflammation, thermogenesis, and potential obesity biomarkers including UCP1, Glut1, MIF, and ceruloplasmin. In conclusion, the protein cargo of BAT EVs is affected by the metabolic status and contains potential biomarkers of thermogenesis activity.
Journal Article
Effect of a Very-Low-Calorie Ketogenic Diet on Circulating Myokine Levels Compared with the Effect of Bariatric Surgery or a Low-Calorie Diet in Patients with Obesity
by
Baltar, Javier
,
Castro, Ana I.
,
Abete, Itziar
in
Adiposity
,
bariatric surgery
,
Bariatric Surgery - adverse effects
2019
The preservation of muscle mass and muscle function after weight loss therapy is currently a considerable challenge in the fight against obesity. Muscle mass secretes proteins called myokines that have relevant functions in the regulation of metabolism and health. This study was aimed to evaluate whether a very low-calorie ketogenic (VLCK) diet may modulate myokine levels, in addition to changes in body composition, compared to a standard, balanced low-calorie (LC) diet or bariatric surgery in patients with obesity. Body composition, ketosis, insulin sensitivity and myokines were evaluated in 79 patients with overweight/obesity after a therapy to lose weight with a VLCK diet, a LC diet or bariatric surgery. The follow-up was 6 months. The weight loss therapies induced changes in myokine levels in association with changes in body composition and biochemical parameters. The effects on circulating myokine levels compared to those at baseline were stronger after the VLCK diet than LC diet or bariatric surgery. Differences reached statistical significance for IL-8, MMP2 and irisin. In conclusion, nutritional interventions or bariatric surgery to lose weight induces changes in circulating myokine levels, being this effect potentially most notable after following a VLCK diet.
Journal Article
Dyslipidemia in Transplant Patients: Which Therapy?
by
Baltar, Javier
,
Calogero, Armando
,
Bresciani, Alessandro
in
Apolipoproteins
,
Atherosclerosis
,
Blood clots
2022
Cardiovascular disease is the most important cause of death worldwide in recent years; an increasing trend is also shown in organ transplant patients subjected to immunosuppressive therapies, in which cardiovascular diseases represent one of the most frequent causes of long-term mortality. This is also linked to immunosuppressant-induced dyslipidemia, which occurs in 27 to 71% of organ transplant recipients. The aim of this review is to clarify the pathophysiological mechanisms underlying dyslipidemia in patients treated with immunosuppressants to identify immunosuppressive therapies which do not cause dyslipidemia or therapeutic pathways effective in reducing hypercholesterolemia, hypertriglyceridemia, or both, without further adverse events.
Journal Article