Galectin-3 Mediates Cardiac Remodeling Caused by Impaired Glucose and Lipid Metabolism Through Inhibiting Two Pathways of Activating Akt

Author(s):  
Zhen Sun ◽  
Lili Zhang ◽  
Lihua Li ◽  
Chen Shao ◽  
Jia Liu ◽  
...  

Pathological cardiac remodeling is a leading cause of mortality in diabetic patients. Given the glucose and lipid metabolism disorders (GLD) in diabetic patients, it is urgent to conduct a comprehensive study of the myocardial damage under GLD and find key mechanisms. Apolipoprotein E knockout (ApoE-/-) mice, low-density lipoprotein receptor heterozygote (Ldlr+/-) syrian golden hamsters or H9C2 cells were used to construct GLD models -. And GLD significantly promoted cardiomyocyte fibrosis, apoptosis and hypertrophy in vivo and in vitro, while inhibition of galectin-3 (Gal-3) could significantly reverse this process. Then, the signal transmission pathways were determined. It was found that GLD considerably inhibited the phosphorylation of Akt at Thr308 / Ser473, whereas the silencing of Gal-3 could reverse the inhibition of Akt activity through PI3K-AktThr308 and AMPK-mTOR2-AktSer473 pathways. Finally, the PI3K, mTOR, AMPK inhibitor and Akt activator were used to investigate the role of pathways in regulating cardiac remodeling. Phospho-AktThr308 could mediate myocardial fibrosis, while myocardial apoptosis and hypertrophy were regulated by both phospho-AktThr308 and phospho-AktSer473. In conclusion, Gal-3 was an important regulatory factor in GLD-induced cardiac remodeling, and Gal-3 could suppress the phosphorylation of Akt at different sites in mediating cardiomyocyte fibrosis, apoptosis and hypertrophy.

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Thomas Vallim ◽  
Elizabeth Tarling ◽  
Tammy Kim ◽  
Mete Civelek ◽  
Angel Baldan ◽  
...  

Rationale The bile acid receptor Farnesoid-X-Receptor (FXR) regulates many aspects of lipid metabolism by various complex and not fully understood molecular mechanisms. We set out to investigate the molecular mechanisms for FXR-dependent regulation of lipid and lipoprotein metabolism. Objective To identify FXR-regulated microRNAs that were subsequently involved in regulating lipid metabolism. Methods and Results ATP binding cassette transporter A1 (ABCA1) is a major determinant of plasma High Density Lipoprotein (HDL)-cholesterol levels. Here we show that activation of the nuclear receptor FXR in vivo increases hepatic levels of miR-144, which in turn lower hepatic ABCA1 and plasma HDL levels. We identified two complementary sequences to miR-144 in the 3’ untranslated region (UTR) of ABCA1 mRNA that are necessary for miR-144-dependent regulation. Overexpression of miR-144 in vitro decreased both cellular ABCA1 protein and cholesterol efflux to lipid-poor apolipoprotein A-I (ApoA-I) protein, whilst overexpression in vivo reduced hepatic ABCA1 protein and plasma HDL- cholesterol. Conversely, silencing miR-144 in mice increased hepatic ABCA1 protein and HDL- cholesterol. In addition, we utilized tissue-specific FXR deficient mice to show that induction of miR-144 and FXR-dependent hypolipidemia requires hepatic, but not intestinal FXR. Finally, we identified functional FXR response elements (FXREs) upstream of the miR-144 locus, consistent with direct FXR regulation. Conclusion In conclusion, we have identified a pathway involving FXR, miR-144 and ABCA1 that together regulate plasma HDL cholesterol. This pathway may be therapeutically targeted in the future in order to increase HDL levels.


2006 ◽  
Vol 154 (1) ◽  
pp. 83-86 ◽  
Author(s):  
S Corbetta ◽  
R Angioni ◽  
A Cattaneo ◽  
P Beck-Peccoz ◽  
A Spada

Objective: In vitro and in vivo models indicate that all-trans retinoic acids influence glucose and lipid metabolism. We aimed to evaluate the effects of chronic treatment with acitretin, an all-trans retinoic acid, on glucose metabolism, lipid profile and adiponectin and resistin levels. Design: Ten normoglycemic, normolipemic patients affected with psoriasis vulgaris were studied before and after 1 and 3 months of oral treatment with 35 μg of acitretin. Methods: Glucose metabolism, lipid profile, and adiponectin and resistin levels were evaluated in basal conditions and after acitretin treatment. Ten healthy subjects matched for age, body mass index (BMI) and insulin sensitivity were studied as controls. Results: One-month acitretin treatment reduced psoriasis activity, insulin sensitivity, evaluated as QUICKI values (0.364 ± 0.034 versus 0.329 ± 0.051; P < 0.05) and HOMA-IR index (1.53 ± 0.73 versus 2.59 ± 1.41; P < 0.05), and high-density lipoprotein (HDL)-cholesterol levels (45.2 ± 11.7 versus 39.4 ± 10.4 mg/dl; P = 0.01). The impairment in glucose and lipid homeostasis was transient and not associated to BMI variations. Adiponectin levels did not change during the treatment, while resistin levels, which were higher in untreated patients than in controls (9.4 ± 4.4 versus 6.2 ± 2.1 ng/ml; P = 0.05), fell within the normal range after 1 and 3 months of therapy. The normalization of resistin levels occurred without significant changes in circulating tumor necrosis factor α (TNFα) levels, which persisted elevated throughout the treatment. Conclusions: Treatment with a low dose of acitretin induced a mild, transient reduction of insulin sensitivity and HDL-cholesterol levels that was not related to modifications of adiponectin, resistin and TNFα levels. Although the role of resistin in humans remains elusive, the levels of this adipocytokine seem to be affected, at least in part, by retinoids.


2000 ◽  
Vol 167 (3) ◽  
pp. 525-531 ◽  
Author(s):  
D Patiag ◽  
X Qu ◽  
S Gray ◽  
I Idris ◽  
M Wilkes ◽  
...  

Angiotensin II (ANGII) increases insulin sensitivity in diabetic and non-diabetic subjects, even at subpressor doses, and because there is 'crosstalk' between ANGII and insulin-signaling pathways the underlying mechanism may not be due solely to changes in regional blood flow. A series of experimental studies was undertaken to evaluate the effects of ANGII on glucose and lipid metabolism in vivo and in vitro. Groups of fructose-fed, insulin-resistant Sprague-Dawley (SD) rats were pre-treated with 0.3 mg/kg per day of the AT(1)-receptor antagonist L-158 809 (n=16), or vehicle (n=16), by oral gavage. This was prior to an oral glucose tolerance test (day 5) and measurement of the effects of ANGII infusion (20 ng/kg per min i.v. for 3 h) on whole-body insulin sensitivity using the insulin suppression test (day 7). The effect of ANGII infusion on total triglyceride secretion rate (TGSR) was evaluated in normal SD rats pretreated for 7 days with L-158 809 (n=12) or vehicle (n=12). AT(1)- and AT(2)- receptor mRNA expression and [(3)H]2-deoxyglucose uptake were assessed in cultured L6 myoblasts. Short-term treatment with L-158 809 had no effect on glucose tolerance or fasting triglyceride levels in fructose-fed rats. ANGII infusion had no effect on insulin sensitivity in fructose-fed rats pretreated with vehicle (steady-state plasma glucose (SSPG) values 8.1+/-1.6 vs 8. 4+/-0.4 mmol/l), but pretreatment with L-158 809 resulted in ANGII having a modest insulin antagonist effect in this insulin-resistant model (SSPG values 9.6+/-0.3 vs 7.1+/-0.6, P<0.03). ANGII infusion had no significant effect on TGSR (e.g. 24.6+/-1.4 vs 28.4+/-0.9 mg/100 g per h in vehicle-treated animals). RT-PCR analysis showed that L6 cells express both AT(1)- and AT(2)-receptor mRNA. Incubation with ANGII (10(-9) and 10(-8) M) had no significant effect on the dose-response curve for insulin-stimulated [(3)H]2-deoxyglucose uptake. For example, C(I200) values (dose of insulin required to increase glucose uptake by 200%) were 4.5 x 10(-9) M (control) vs 3.9 x 10(-9) M and 6.2 x 10(-9) M, whereas the positive control (glucagon-like peptide-1) increased insulin sensitivity. Thus, ANGII infusion may have a modest insulin antagonist effect on glucose disposal in insulin-resistant fructose-fed rats pretreated with an AT(1)-blocker, but ANGII has no effect on TGSR or in vitro glucose uptake in L6 myoblasts. These findings are relevant to recent clinical discussions about the metabolic effects of ANGII and renin-angiotensin system blockade.


1992 ◽  
Vol 82 (3) ◽  
pp. 339-339
Author(s):  
J. M. Ritter ◽  
G. C. Viberti

1. Na+/Li+ countertransport is not a gold standard, or indeed any other kind of standard. It is a measure of the activity of one particular cation exchanger. 2. There is a large body of literature regarding the effects of oxidized low-density lipoprotein (LDL) in experimental animals and in vitro. Whether abnormal oxidized LDL or one of many other possible mechanisms underlies the inverse relationship that we observed between vascular sensitivity in vivo to nitroprusside or carbachol with erythrocyte Na+/Li+ countertransport in diabetic patients remains to be seen. 3. We caution against post hoc subgroup analysis (smokers versus non-smokers, low versus high plasma lipid levels, etc.) in studies of this size.


2018 ◽  
Vol 48 (5) ◽  
pp. 1995-2010 ◽  
Author(s):  
Yan Sun ◽  
Dai Zhang ◽  
Xiaoli Liu ◽  
Xuesong Li ◽  
Fang Liu ◽  
...  

Background/Aims: Endoplasmic reticulum (ER) stress is an important event in atherosclerosis. Recent studies have shown that ER stress deregulates cholesterol metabolism via multiple pathways. This study aimed to determine the relationship between ER stress and lipid metabolism and to verify that upregulation of miR-33 is involved in this process. Methods: An atherosclerosis model was established in apolipoprotein E-deficient (ApoE-/-) mice fed a Western diet, and THP-1 derived macrophages were used in this study. Hematoxylin-eosin and Oil Red O staining were used to quantify the atherosclerotic plaques. 1,1′-Dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate labeled oxidized low-density lipoprotein binding assay and a Cholesterol Efflux Fluorometric Assay Kit were used to observe cholesterol uptake and efflux. The mRNA and protein levels of biomarkers associated with ER stress and cholesterol metabolism in atherosclerotic plaques and macrophages were evaluated by real-time PCR and western blotting, respectively. Immunofluorescence was used to observe alterations of ABCA1 localization. Small interfering RNAs were used to knock down CHOP and miR-33 in macrophages to alter CHOP and miR-33 expression. Results: Atherosclerotic lesions and systemic lipid levels were ameliorated after inhibition of ER stress (tauroursodeoxycholic acid) in vivo. In vitro studies confirmed that ER stress regulated the lipid catabolism of macrophages by promoting cholesterol uptake, inhibiting cholesterol efflux, and modulating the expression of related transporters. CHOP contributed to lipid metabolism disorder following ER stress. Furthermore, over-expression of miR-33 was involved in ER stress that induced lipid metabolism disorder in macrophages. These findings support a model of ER stress induction by oxidized low-density lipoprotein that affects macrophage lipid catabolism disorder. Conclusion: Our data shed new light on the relationship between ER stress and lipid metabolism in vivo and in vitro, and confirm that upregulation of miR-33 is involved in this process. The relationship between ER stress and miR-33 represents a novel target for the treatment of atherosclerosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ya-nv Liu ◽  
Lin Wang ◽  
Xin Fan ◽  
Shijie Liu ◽  
Qi Wu ◽  
...  

This research review aimed to evaluate the effect of practicing Tai Chi on glucose and lipid metabolism in middle-aged and elderly diabetic patients. Furthermore, it aimed to provide a theoretical basis for the practice of Tai Chi as a way to improve glucose and lipid metabolism in middle-aged and elderly diabetic patients. Therefore, we searched for randomized controlled trials on the practice of Tai Chi in middle-aged and elderly diabetic patients in Chinese- and English-language electronic databases, such as Web of Science, PubMed, the Cochrane Library, EMBASE, Google Scholar, CNKI, Wanfang Database, and Weipu. We collected articles published no later than August 1, 2020. The methodological quality of the included studies was evaluated according to the standards of the Cochrane Collaboration System Evaluation Manual (version 5.1.0). Finally, 14 articles were included, showing an average Physiotherapy Evidence Database scale score of 6.57. The articles were meta-analyzed using Stata 14.0 software, showing that practicing Tai Chi improved middle-aged and elderly diabetic patients’ fasting blood glucose (WMD = −0.60, 95% CI [−1.08, −0.12], p = 0.015 ), glycosylated hemoglobin (WMD = −0.87, 95% CI [−1.60, −0.14], p = 0.019 ), total cholesterol (WMD = −0.48, 95% CI [−0.83, −0.14], p = 0.006 ), triglycerides (WMD = −0.21, 95% CI [−0.37, −0.04], p = 0.014 ), and low-density lipoprotein cholesterol level significantly (WMD = −0.32, 95% CI [−0.63,−0.00], p = 0.050 ). Conversely, patients’ high-density lipoprotein cholesterol levels (WMD = 0.09, 95% CI [−0.01, 0.17], p = 0.136 ) showed no obvious improvement. In conclusion, practicing Tai Chi in sessions lasting longer than 50 minutes (at least three times per week, for at least 12 weeks) can effectively improve glucose and lipid metabolism in middle-aged and elderly diabetic patients. However, several other factors affect glucose and lipid metabolism; therefore, further high-quality research is needed. Protocol registration number: INPLASY2020120107.


2022 ◽  
Vol 22 ◽  
pp. 100930
Author(s):  
Liping Yang ◽  
Wenlei Zhang ◽  
Shaoyang Zhi ◽  
Mingyu Liu ◽  
Mengjuan Zhao ◽  
...  

1998 ◽  
Vol 94 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Nathalie Caillol ◽  
Eric Pasqualini ◽  
Eric Mas ◽  
Régis Guieu ◽  
Anne Valette ◽  
...  

1. Pancreatic bile-salt-dependent lipase has been detected in human plasma where it has the capability to modify normal low- and high-density lipoprotein composition and structure and to reduce the atherogenicity of oxidized low-density lipoprotein (Shamir R, Johnson WJ, Morlock-Fitzpatrick K, Zolfaghari R, Li L, Mas E, Lombardo D, Morel DW, Fisher EA. Pancreatic carboxyl ester lipase: a circulating enzyme that modifies normal and oxidized lipoproteins in vitro. J Clin Invest 1996; 97: 1696–704). 2. In the present study, we investigated the effect of glycation and particularly that of human serum albumin on the activity of bile-salt-dependent lipase. In vitro, bile-salt-dependent lipase activity decreased in the presence of human serum albumin; however, this was less pronounced in the presence of glycated human serum albumin. In vivo, bile-salt-dependent lipase specific activity was about 2-fold higher in the sera of diabetic patients than in the sera of normal subjects. 3. A significant increase in the specific activity of bile-salt-dependent lipase related to the serum level of glycation was observed. The increase in bile-salt-dependent lipase specific activity was not related to the glucose concentration in serum suggesting that glycation of bile-salt-dependent lipase could not be involved in the observed effects. Although the stability of serum bile-salt-dependent lipase was important enough to allow a systemic action of the enzyme on lipoproteins, it could not explain the higher activity of the enzyme in diabetic serum. 4. We concluded that bile-salt-dependent lipase could be helpful against the premature development of atherosclerosis in diabetes.


2019 ◽  
Vol 87 (4) ◽  
pp. 26 ◽  
Author(s):  
Sivamaruthi ◽  
Kesika ◽  
Chaiyasut

Cardiovascular diseases (CVD) are the major health issue of modernized society with a high mortality rate. Lifestyle, genetic makeup, and diet are some of the major influencing factors associated with CVD. The dyslipidemia is one such factor related to the development of several CVD. Many studies proved that the consumption of probiotics confers several health benefits. Several studies reported the evaluation of the cholesterol-lowering ability of probiotics (probiotics that showed positive effect in vitro and in vivo studies) in human volunteers. The current review summarizes the outcomes of human studies on the cholesterol-lowering property of probiotics. Probiotic consumption significantly improved the health status of hypercholesteremic patients by reducing the low-density lipoprotein cholesterol, total cholesterol, triglyceride levels, and increased the high-density lipoprotein cholesterol. The probiotic supplementation improved the lipid profile of diabetic patients, and obese people as well. However, not all probiotic interventions are effective against dyslipidemia. The results are controversial and depend on several factors such as probiotic strain, dose, duration of the treatment, lifestyle changes, etc. This literature survey indorses additional studies on the cholesterol-lowering property of probiotics, which could help to reduce the risk of CVD and other dyslipidemia associated health issues.


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