Lpin1 in human visceral and subcutaneous adipose tissue: similar levels but different associations with lipogenic and lipolytic genes

2010 ◽  
Vol 299 (2) ◽  
pp. E308-E317 ◽  
Author(s):  
Merce Miranda ◽  
Xavier Escoté ◽  
María J. Alcaide ◽  
Esther Solano ◽  
Victòria Ceperuelo-Mallafré ◽  
...  

LPIN1 is a gene with important effects on lipidic and metabolic homeostasis. Human subcutaneous LPIN1 expression levels in adipose tissue are related with a better metabolic profile, including insulin sensitivity markers. However, there are few data on the regulation of LPIN1 in visceral adipose tissue (VAT). Our aim was to perform a cross-sectional analysis of VAT compared with subcutaneous (SAT) LPIN1 expression in a well-characterized obese cohort, its relation with the expression of genes involved in lipid metabolism, and the in vitro response to lipogenic and lipolytic stimuli. A downregulation of total LPIN1 mRNA expression in subjects with obesity was found in VAT similarly to that in SAT. Despite similar total LPIN1 mRNA levels in SAT and VAT, a close relationship with clinical parameters and with many lipogenic and lipolytic genes was observed primarily in SAT depot. As shown in the in vitro analysis, the low-grade proinflammatory environment and the insulin resistance associated with obesity may contribute to downregulate LPIN1 in adipose tissue, leading to a worse metabolic profile.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maki Murakoshi ◽  
Tomohito Gohda ◽  
Eri Adachi ◽  
Saki Ichikawa ◽  
Shinji Hagiwara ◽  
...  

AbstractProgranulin (PGRN) has been reported to bind tumor necrosis factor (TNF) receptor and to inhibit TNFα signaling. We evaluated the effect of augmentation of TNFα signaling by PGRN deficiency on the progression of kidney injury. Eight-week-old PGRN knockout (KO) and wild-type (WT) mice were fed a standard diet or high-fat diet (HFD) for 12 weeks. Albuminuria, markers of tubular damage, and renal mRNA levels of inflammatory cytokines were higher in HFD-fed KO (KO-HFD) mice than in HFD-fed WT (WT-HFD) mice. Body weight, vacuolization in proximal tubules, and systemic and adipose tissue inflammatory markers were lower in the KO-HFD mice than in the WT-HFD mice. The renal megalin expression was lower in the KO mice than in the WT mice regardless of the diet type. The megalin expression was also reduced in mouse proximal tubule epithelial cells stimulated with TNFα and in those with PGRN knockdown by small interfering RNA in vitro. PGRN deficiency was associated with both exacerbated renal inflammation and decreased systemic inflammation, including that in the adipose tissue of mice with HFD-induced obesity. Improved tubular vacuolization in the KO-HFD mice might partially be explained by the decreased expression of megalin in proximal tubules.


Diabetologia ◽  
2021 ◽  
Author(s):  
Juliana de Almeida-Faria ◽  
Daniella E. Duque-Guimarães ◽  
Thomas P. Ong ◽  
Lucas C. Pantaleão ◽  
Asha A. Carpenter ◽  
...  

Abstract Aims/hypothesis Levels of the microRNA (miRNA) miR-126-3p are programmed cell-autonomously in visceral adipose tissue of adult offspring born to obese female C57BL/6J mice. The spectrum of miR-126-3p targets and thus the consequences of its dysregulation for adipocyte metabolism are unknown. Therefore, the aim of the current study was to identify novel targets of miR-126-3p in vitro and then establish the outcomes of their dysregulation on adipocyte metabolism in vivo using a well-established maternal obesity mouse model. Methods miR-126-3p overexpression in 3T3-L1 pre-adipocytes followed by pulsed stable isotope labelling by amino acids in culture (pSILAC) was performed to identify novel targets of the miRNA. Well-established bioinformatics algorithms and luciferase assays were then employed to confirm those that were direct targets of miR-126-3p. Selected knockdown experiments were performed in vitro to define the consequences of target dysregulation. Quantitative real-time PCR, immunoblotting, histology, euglycaemic–hyperinsulinaemic clamps and glucose tolerance tests were performed to determine the phenotypic and functional outcomes of maternal programmed miR-126-3p levels in offspring adipose tissue. Results The proteomic approach confirmed the identity of known targets of miR-126-3p (including IRS-1) and identified Lunapark, an endoplasmic reticulum (ER) protein, as a novel one. We confirmed by luciferase assay that Lunapark was a direct target of miR-126-3p. Overexpression of miR-126-3p in vitro led to a reduction in Lunapark protein levels and increased Perk (also known as Eif2ak3) mRNA levels and small interference-RNA mediated knockdown of Lunapark led to increased Xbp1, spliced Xbp1, Chop (also known as Ddit3) and Perk mRNA levels and an ER stress transcriptional response in 3T3-L1 pre-adipocytes. Consistent with the results found in vitro, increased miR-126-3p expression in adipose tissue from adult mouse offspring born to obese dams was accompanied by decreased Lunapark and IRS-1 protein levels and increased markers of ER stress. At the whole-body level the animals displayed glucose intolerance. Conclusions/interpretation Concurrently targeting IRS-1 and Lunapark, a nutritionally programmed increase in miR-126-3p causes adipose tissue insulin resistance and an ER stress response, both of which may contribute to impaired glucose tolerance. These findings provide a novel mechanism by which obesity during pregnancy leads to increased risk of type 2 diabetes in the offspring and therefore identify miR-126-3p as a potential therapeutic target. Graphical abstract


2012 ◽  
Vol 7 (2) ◽  
pp. 192-200
Author(s):  
Jacek Turyn ◽  
Adriana Mika ◽  
Piotr Stepnowski ◽  
Julian Swierczynski

AbstractIt is generally accepted that the location of body fat deposits may play an important role in the risk of developing some endocrine and metabolic diseases. We have studied the effect of food restriction and food restriction/refeeding, often practiced by individuals trying to lose body weight, on the expression of genes which are associated with obesity and certain metabolic disorders in inguinal, epididymal, and perirenal rat white adipose tissues. Gene expression was analyzed by real time semi-quantitative polymerase chain reaction and by Western blot. We found that prolonged food restriction caused a significant decrease of body and adipose tissue mass as well as the increase of Scd1 and Elovl6 gene expressions in all main rat adipose tissue deposits. Food restriction/refeeding caused increases of: a) Scd1 and Elovl6 mRNA levels in adipose tissue, b) Scd1 protein level and c) desaturation index in adipose tissue. The increased expression of both genes was unusually high in inguinal adipose tissue. The results suggest that the increase of Scd1 and Elovl6 gene expressions in white adipose tissue by prolonged food restriction and prolonged food restriction/refeeding may contribute to accelerated fat recovery that often occurs in individuals after food restriction/refeeding.


2009 ◽  
Vol 68 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Henrike Sell ◽  
Jürgen Eckel

A strong causal link between increased adipose tissue mass and insulin resistance in tissues such as liver and skeletal muscle exists in obesity-related disorders such as type 2 diabetes. Increased adipose tissue mass in obese patients and patients with diabetes is associated with altered secretion of adipokines, which also includes chemotactic proteins. Adipose tissue releases a wide range of chemotactic proteins including many chemokines and chemerin, which are interesting targets for adipose tissue biology and for biomedical research in obesity and obesity-related diseases. This class of adipokines may be directly linked to a chronic state of low-grade inflammation and macrophage infiltration in adipose tissue, a concept intensively studied in adipose tissue biology in recent years. The inflammatory state of adipose tissue in obese patients may be the most important factor linking increased adipose tissue mass to insulin resistance. Furthermore, chemoattractant adipokines may play an important role in this situation, as many of these proteins possess biological activity beyond the recruitment of immune cells including effects on adipogenesis and glucose homeostasis in insulin-sensitive tissues. The present review provides a summary of experimental evidence of the role of adipose tissue-derived chemotactic cytokines and their function in insulin resistancein vivoandin vitro.


2018 ◽  
Vol 51 (3) ◽  
pp. 1051-1068 ◽  
Author(s):  
Jèssica Latorre ◽  
José M. Moreno-Navarrete ◽  
Mónica Sabater ◽  
Maria Buxo ◽  
José I. Rodriguez-Hermosa ◽  
...  

Background/Aims: Obesity is characterized by the immune activation that eventually dampens insulin sensitivity and changes metabolism. This study explores the impact of different inflammatory/ anti-inflammatory paradigms on the expression of toll-like receptors (TLR) found in adipocyte cultures, adipose tissue, and blood. Methods: We evaluated by real time PCR the impact of acute surgery stress in vivo (adipose tissue) and macrophages (MCM) in vitro (adipocytes). Weight loss was chosen as an anti-inflammatory model, so TLR were analyzed in fat samples collected before and after bariatric surgery-induced weight loss. Associations with inflammatory and metabolic parameters were analyzed in non-obese and obese subjects, in parallel with gene expression measures taken in blood and isolated adipocytes/ stromal-vascular cells (SVC). Treatments with an agonist of TLR3 were conducted in human adipocyte cultures under normal conditions and upon conditions that simulated the chronic low-grade inflammatory state of obesity. Results: Surgery stress raised TLR1 and TLR8 in subcutaneous (SAT), and TLR2 in SAT and visceral (VAT) adipose tissue, while decreasing VAT TLR3 and TLR4. MCM led to increased TLR2 and diminished TLR3, TLR4, and TLR5 expressions in human adipocytes. The anti-inflammatory impact of weight loss was concomitant with decreased TLR1, TLR3, and TLR8 in SAT. Cross-sectional associations confirmed increased V/ SAT TLR1 and TLR8, and decreased TLR3 in obese patients, as compared with non-obese subjects. As expected, TLR were predominant in SVC and adipocyte precursor cells, even though expression of all of them but TLR8 (very low levels) was also found in ex vivo isolated and in vitro differentiated adipocytes. Among SVC, CD14+ macrophages showed increased TLR1, TLR2, and TLR7, but decreased TLR3 mRNA. The opposite patterns shown for TLR2 and TLR3 in V/ SAT, SVC, and inflamed adipocytes were observed in blood as well, being TLR3 more likely linked to lymphocyte instead of neutrophil counts. On the other hand, decreased TLR3 in adipocytes challenged with MCM dampened lipogenesis and the inflammatory response to Poly(I:C). Conclusion: Functional variations in the expression of TLR found in blood and hypertrophied fat depots, namely decreased TLR3 in lymphocytes and inflamed adipocytes, are linked to metabolic inflammation.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jacqueline Taylor ◽  
Julia Sellin ◽  
Lars Kuerschner ◽  
Lennart Krähl ◽  
Yasmin Majlesain ◽  
...  

AbstractAdipose tissue is an organized endocrine organ with important metabolic and immunological functions and immune cell-adipocyte crosstalk is known to drive various disease pathologies. Suitable 3D adipose tissue organoid models often lack resident immune cell populations and therefore require the addition of immune cells isolated from other organs. We have created the first 3D adipose tissue organoid model which could contain and maintain resident immune cell populations of the stromal vascular fraction (SVF) and proved to be effective in studying adipose tissue biology in a convenient manner. Macrophage and mast cell populations were successfully confirmed within our organoid model and were maintained in culture without the addition of growth factors. We demonstrated the suitability of our model for monitoring the lipidome during adipocyte differentiation in vitro and confirmed that this model reflects the physiological lipidome better than standard 2D cultures. In addition, we applied mass spectrometry-based lipidomics to track lipidomic changes in the lipidome upon dietary and immunomodulatory interventions. We conclude that this model represents a valuable tool for immune-metabolic research.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Pia Fuggetta ◽  
Manuela Zonfrillo ◽  
Cristina Villivà ◽  
Enzo Bonmassar ◽  
Giampiero Ravagnan

Objective. Obesity is considered a clinic condition characterized by a state of chronic low-grade inflammation. The role of macrophages and adipocytokines in adipose tissue inflammation is in growing investigation. The physiopathological mechanisms involved in inflammatory state in obesity are not fully understood though the adipocytokines seem to characterize the biochemical link between obesity and inflammation. The aim of this work is to analyze the effect of theobromine, a methylxanthine present in the cocoa, on adipogenesis and on proinflammatory cytokines evaluated in a model of fat tissue inflammation in vitro. Methods. In order to mimic in vitro this inflammatory condition, we investigated the interactions between human-like macrophages U937 and human adipocyte cell lines SGBS. The effect of theobromine on in vitro cell growth, cell cycle, adipogenesis, and cytokines release in the supernatants has been evaluated. Results. Theobromine significantly inhibits the differentiation of preadipocytes in mature adipocytes and reduces the levels of proinflammatory cytokines as MCP-1 and IL-1β in the supernatants obtained by the mature adipocytes and macrophages interaction. Conclusion. Theobromine reduces adipogenesis and proinflammatory cytokines; these data suggest its potential therapeutic effect for treating obesity by control of macrophages infiltration in adipose tissue and inflammation.


2000 ◽  
pp. 71-78 ◽  
Author(s):  
A Gorla-Bajszczak ◽  
C Siegrist-Kaiser ◽  
O Boss ◽  
AG Burger ◽  
CA Meier

OBJECTIVE: Examination of the pattern of expression of peroxisome proliferator-activated receptor (PPAR) isoforms alpha and gamma in a model of obesity. DESIGN: Examination of adipose tissue and primary adipocyte cultures from lean and obese Zucker rats at different ages (28 days and 12 weeks). METHODS: mRNA levels were measured by RNase protection assay.RESULTS: The highest levels of PPARalpha and gamma mRNA were present in brown adipose tissue (BAT), followed by liver and white adipose tissue (WAT) for the alpha and gamma subtypes, respectively, at both ages examined. PPARalpha was expressed 100-fold higher in BAT compared with WAT, and PPARgamma mRNA levels were 2-fold higher in the WAT of obese compared with lean rats. PPARalpha and gamma expression was minimal in m. soleus, although higher levels of PPARgamma were found in the diaphragm. In marked contrast to the findings in vivo, virtually no PPARalpha mRNA could be detected in BAT cultures differentiated in vitro. CONCLUSION: PPARalpha and gamma are most highly expressed in BAT in vivo. However, PPARalpha is undetectable in brown adipose cells in vitro, suggesting that the expression of this receptor is induced by some external stimuli. In addition, the expression of PPARgamma was increased in WAT from young obese animals, compatible with an early adaptive phenomenon. Finally, the presence of PPARgamma mRNA is detectable only in particular muscles, such as the diaphragm, suggesting the possibility of an influence of fiber type on its expression, although exercise did not influence the expression of PPARgamma in other skeletal muscles.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1209-1209
Author(s):  
Hanna Davis ◽  
Mandana Pahlavani ◽  
Yujiao Zu ◽  
Latha Ramalingam ◽  
Shane Scoggin ◽  
...  

Abstract Objectives Obesity is a global epidemic and complex disease associated with an expansion of white adipose tissue (WAT). Obesity is accompanied by chronic low-grade inflammation, characterized by elevated levels of secreted pro-inflammatory cytokines and M1 macrophage infiltration into WAT. Eicosapentaenoic acid (EPA), a long-chain omega-3 polyunsaturated fatty acid, has been reported to have anti-obesity and anti-inflammatory properties. Moreover, we previously showed that EPA dose-dependently improved glucose intolerance, and inflammation in diet-induced obese mice. The objective of this study is to further determine mechanisms underlying these metabolic protective effects of EPA in epididymal WAT (e-WAT). Methods Male B6 mice were fed a HF diet (45% kcal fat) or a HF diet supplemented with 9, 18, or 36 g/kg of EPA-enriched fish oil (EPA 9, 18 or 36) for 14 weeks. We performed histological assessments in eWAT to determine adipocyte size; and measure macrophage infiltration by immunohistochemistry using galectin-3. RNA was isolated from eWAT for RNA sequencing and gene expression analyses. Data were analyzed using GraphPad Prism software. Results EPA36-fed mice had significantly lower body weight and fat percentage, compared to HF (P < 0.05). In addition, EPA18 and 36 significantly decreased weight of e-WAT (P < 0.05) and increased glucose clearance compared to HF (P < 0.05). Moreover, all EPA doses had smaller adipocytes (P < 0.05). Compared to HF, EPA18 and 36 significantly reduced macrophage infiltration in e-7.43 fold, respectively. Consistent with these changes, EPA18 and 36 reduced the mRNA levels of HF-induced inflammatory markers, including arachidonate 5-lipoxygenase (Alox5) and leukotriene B4 receptor (Ltb4r) compared to HF (P < 0.05). RNA Seq analyses revealed that EPA18 attenuated HF-induced inflammation in part by up-regulating cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathways and down-regulating triggering receptor expressed on myeloid cells 1 (TREM1) signaling. Conclusions EPA dose-dependently ameliorated HF-induced obesity and inflammation by reducing adipocyte size and macrophage infiltration and modulating pro- and anti-inflammatory pathways in e-WAT. These effects were achieved at human equivalent doses, that are currently prescribed for reducing triglycerides. Funding Sources USDA NIFA NIH.


2021 ◽  
Author(s):  
Sakulrat Mankhong ◽  
Sujin Kim ◽  
Sohee Moon ◽  
Seong-Hye Choi ◽  
Hyo-Bum Kwak ◽  
...  

Abstract BACKGROUNDA role for extracellular vesicles (EVs) enriched with micro-RNAs (miRNAs) has been proposed in Alzheimer’s disease (AD) pathogenesis, leading to the discovery of blood miRNAs as biomarkers of AD. However, the diagnostic utility of specific miRNAs is not consistent. This study aimed to discover blood miRNAs that are differentially expressed in Korean AD patients, evaluate their clinical performance in plasma or plasma EVs, and investigate their role in amyloidogenesis. METHODSBlood from 15 (7 cognitively normal [CN] and 8 AD) out of 262 subjects (59 CN, 105 mild cognitive impairment [MCI], 98 AD) and 8 Parkinson’s disease (PD) patients was used to discover miRNAs differentially expressed in AD. We evaluated the clinical performance of these miRNAs in plasma of a subgroup of 100 subjects (51 CN, 22 MCI, 27 AD) and in plasma EVs isolated from the total cohort in a cross-sectional design. The effects of miRNAs on amyloid b (Ab) production and expression of their target genes were investigated in neuronal culture systems. RESULTSAmong 17 upregulated, and one downregulated miRNAs in AD (>2-fold), three upregulated miRNAs (miR-122-5p, miR-210-3p, and miR-590-5p) that were differentially expressed in AD compared with CN or PD were selected. Diagnostic utility for discrimination of AD or MCI from CN of the selected miRNAs in plasma or plasma EV was not high. Nevertheless, the levels of three miRNAs in plasma or plasma EVs of subjects who were Ab positive on positron emission tomography (PET) were significantly higher than those from subjects who were Ab-PET negative. Furthermore, the selected miRNAs induced Ab production through activation of b-cleavage of amyloid precursor protein and downregulated their target genes. Pathway enrichment and protein interaction network analysis of target genes of the miRNAs further supported the roles of the selected miRNAs in amyloidogenesis. CONCLUSIONThe diagnostic utility of circulating miR-122-5p, miR-210-3p, and miR-590-5p to discriminate AD from CN was modest. However, these miRNAs were highly expressed in patients with amyloid accumulation, which was supported by in vitro analysis of amyloidogenesis. Our results suggest that blood-based miRNA biomarkers may play a role in amyloidogenesis during AD onset and progression.


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