Liraglutide protects cardiac function in diabetic rats through the PPARα pathway

Liraglutide ameliorates diabetic-induced testicular dysfunction in male rats: role of GLP-1/Kiss1/GnRH and TGF-β/Smad signaling pathways

Introduction: Glucagon-like peptide -1 (GLP-1) is released by intestinal cells to stimulate glucose-dependent insulin release from the pancreas. GLP-1 has been linked to ameliorating obesity and/or diabetic complications as well as controlling reproductive function. Liraglutide is a GLP-1 receptor agonist (GLP-1RA) with 97% homology with GLP-1. The main objective of this study was to investigate the ameliorative role of liraglutide in diabetic-induced reproductive dysfunction in male rats. Methods: Rats were randomly allocated into 3 groups; a control group, a diabetic group, and a liraglutide-treated diabetic group. Results: In the diabetic group, a significant increase in BMI, FBG, HbA1c, HOMA-IR, TC, TAG, LDL, IL6, TNFα, and MDA, as well as decreased serum insulin, HDL, GSH, total testosterone, LH, and FSH, were shown compared to the control group. Furthermore, A significant downregulation in relative hypothalamic gene expression of GLP-1R, PPAR-α, PGC-1α, kiss, kiss1R, leptin, leptin R, GnRH GLP-1R, testicular PGC-1α, PPARα, kiss1, kiss1R, STAR, CYP17A1, HSD17B3, CYP19A, CYP11A1, and Smad7, as well as upregulation in hypothalamic GnIH and testicular TGF- β and Smad2 expression, were noticed compared to the control group. Liraglutide treatment significantly improved such functional and structural reproductive disturbance in diabetic rats. Conclusion: GLP-1RAs ameliorated the deleterious effects of diabetes on reproductive function by targeting GLP-1/leptin/kiss1/GnRH, steroidogenesis, and TGF- β/Smad pathways.

Liraglutide Attenuates Hepatic Oxidative Stress, Inflammation, and Apoptosis in Streptozotocin-Induced Diabetic Mice by Modulating the Wnt/β-Catenin Signaling Pathway

Liraglutide has been extensively applied in the treatment of type 2 diabetes mellitus and also has hepatoprotective effects. However, the role of liraglutide treatment on liver injury in a mouse model of type 1 diabetes mellitus (T1DM) induced by streptozotocin (STZ) and its underlying mechanisms remain to be elucidated. In the present study, diabetes was initiated in experimental animals by single-dose intraperitoneal inoculation of STZ. Forty female C57BL/6J mice were equally assigned into five groups: diabetic group, insulin+diabetic group, liraglutide+diabetic group, insulin+liraglutide+diabetic group, and control group for eight weeks. Diabetic mice exhibited a significantly elevated blood glucose level and decreased body weight, and morphological changes of increased steatosis and apoptosis were observed in the liver compared with the control. Furthermore, a significant increase in the levels of malondialdehyde and inflammatory markers such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin 1β (IL-1β) and the proapoptotic proteins caspase-3 and Bax were observed in the livers of diabetic mice, together with marked increases in antioxidants superoxide dismutase (SOD) and glutathione peroxidase (GPX) as well as antiapoptotic protein Bcl-2, all of which were significantly mitigated by treatment with liraglutide, insulin, and their combinations. Interestingly, liraglutide monotherapy showed better efficacy in ameliorating liver injury in T1DM mice than insulin monotherapy, similar to the combined drug therapy. Furthermore, the expression of Wnt/β-catenin signaling pathway-associated molecules was upregulated in the liver of mice treated with liraglutide or insulin. The results of the present study suggested that liraglutide improves T1DM-induced liver injury and may have important implications for the treatment of nonalcoholic fatty liver disease (NAFLD) in patients with T1DM.

The Effect of Clinically Indicated Liraglutide on Pericoronary Adipose Tissue in Type 2 Diabetic Patients

Vascular inflammation can be detected in the pericoronary adipose tissue (PCAT) by coronary computed tomography angiography (CCTA) attenuation. Treatment with liraglutide is associated with anti-inflammatory effects and reduces cardiovascular risk in diabetic patients. This study is aimed at examining the effect of clinically indicated liraglutide on PCAT attenuation. Asymptomatic patients with type 2 diabetes mellitus (T2DM) and without known ischemic heart disease underwent clinical examination, blood analysis, and CCTA. The main coronary arteries were outlined and PCAT attenuation was measured on the proximal 40 mm. Patients treated with liraglutide on a clinical indication were compared to patients not receiving liraglutide. The study included 190 patients; 53 (28%) received liraglutide (Lira+) and 137 (72%) did not (Lira-). There were no significant differences in PCAT attenuation between the two groups in either artery. However, PCAT attenuation measured around the left anterior descending artery (LAD) was lower in the Lira+ group after adjustment for age, sex, body mass index, and T2DM duration (b coefficient -2.4, p = 0.029). In a population of cardiac asymptomatic T2DM patients, treatment with clinically indicated liraglutide was not associated with differences in PCAT attenuation compared to nonliraglutide treatment in the unadjusted model. An association was seen in the adjusted model for the left anterior descending artery, possibly indicating an anti-inflammatory effect.

Liraglutide treatment attenuates inflammation markers in the cardiac, cerebral and renal microvasculature in streptozotocin-induced diabetic rats

BACKGROUND

Diabetes mellitus (DM) induces cardiac and cerebral microvascular dysfunction via increased glycation, oxidative stress and endothelial activation. Liraglutide, a glucagon-like peptide-1 analogue, inhibited NOX2 and adhesion molecules in isolated endothelial cells. Here, we have studied how Liraglutide affects advanced glycation, NOX expression and inflammation of the cardiac, cerebral and renal microvasculature in diabetic rats.

METHODS

DM was induced in Sprague-Dawley rats (n = 15) via intraperitoneal streptozotocin (STZ) injection (60 mg/kg bodyweight). Ten control rats remained nondiabetic. From day 9 post-STZ injection, Liraglutide (200 μg/kg bodyweight; n = 7) or vehicle (n = 8) was injected subcutaneously daily until termination on day 29. The advanced glycation endproduct N-ε-(carboxymethyl)lysine (CML), NOX2, NOX4, ICAM-1 and VCAM-1 were subsequently immunohistochemically analysed and quantified to compare Liraglutide treatment with placebo.

RESULTS

In the heart, Liraglutide treatment significantly reduced the DM-increased scores/cm² for CML in both ventricles (from 253 ± 53 to 72 ± 12; p = .003) and atria (343 ± 29 to 122 ± 8; p = .0001) and for NOX2, ICAM-1 and VCAM-1, but not for NOX4. Also in the cerebrum and cerebellum of the brain, Liraglutide significantly reduced the scores/cm² for CML (to 60 ± 7 (p = .0005) and 47 ± 13 (p = .02), respectively), and for NOX2 and NOX4. In the kidney, the DM-induced expression of ICAM-1 and VCAM-1 was decreased in the blood vessels and glomeruli by Liraglutide treatment. Liraglutide did not affect blood glucose levels or bodyweight.

CONCLUSIONS

Our study implies that Liraglutide protects the cardiac, cerebral and renal microvasculature against diabetes-induced dysfunction, independent of lowering blood glucose in a type 1 diabetes rat model.

Effect of nano extracts of olea europaea leaves, ficus carica and liraglutide in lipidemic liver of type 2 diabetic rat model

The study aimed to evaluate the impact of Ficus carica mixture and Olea europaea leaf nano extracts, and liraglutide, on liver tissue and serum lipids in type 2 diabetic male albino rat model. Forty rats were divided equally into 4 groups were used. Group 1 was the non-diabetic control group. The animals in Groups 2–4 was injected intraperitoneally with a single dose of 60 mg/kg b.w. Streptozotocin to induce a diabetic rat model. Group 2 served as a positive control for diabetes. 0.02 mg/kg b.w./day of Liraglutide gave to groups 3 and 4 and 4.8 ng/ml × 10⁵ b.w./day of a mixture of the nano extracts, respectively. Eight weeks after treatment, the animals were sacrificed. Blood was collected for glucose analysis and serum low-density lipoprotein, high-density lipoprotein, total cholesterol, and triglycerides analysis, and the livers processed for histopathological examination. The elevated lipid profiles and blood glucose levels in diabetic group (Group 2) were significantly reduced (p < 0.001) following the administration of liraglutide and nano extracts in Groups 3 and 4. Progressive fatty acid changes were found in the liver sections, indicated by the deposition of various sizes of lipid droplets in most liver lobules, along with patchy hepatocyte necrosis. These pathological changes were ameliorated in the liraglutide- and nano-extract-treated rats. Treatment with the nano extracts resulted in significant power assays associated with recovery of hepatic histology and functional alterations, compared to liraglutide treatment.

Liraglutide ameliorates myocardial damage in experimental diabetic rats by inhibiting pyroptosis via Sirt1/AMPK signaling

OBJECTIVES

Liraglutide, a well-established drug for treating diabetes mellitus (DM), has recently gained attention for its cardiovascular benefits in diabetes via multiple cellular activities; however, whether liraglutide improves myocardial damage by inhibiting pyroptosis and the mechanisms of these potential effects remain unknown.

MATERIALS AND METHODS

In this study, high-fat diet feeding and low-dose streptozotocin (STZ) injection were used to construct a rat DM model. Rats with fasting blood glucose (FBG) levels >16.7 mmol/l received subcutaneous injections of liraglutide (0.2 mg/kg) for 4 weeks. Metabolic parameters, the heart weight/body weight (HW/BW) ratio, and histopathology were examined. Protein levels of inflammatory, pyroptosis, and NOD-like receptor protein 3 (NLRP3) inflammasome markers were assessed via Western blotting. In in vitro studies, a sirtuin 1 (Sirt1) inhibitor (EX 527, 200 nM) and an AMP-activated protein kinase (AMPK) inhibitor (compound C, 20 µM) were used to inhibit Sirt1 and AMPK pathways, respectively.

RESULTS

Liraglutide significantly attenuated cardiac hypertrophy, pathological changes, inflammation, pyroptosis, and NLRP3 inflammasome activation, accompanied by increased Sirt1 and AMPK activation. Consistent with the in vivo results, liraglutide attenuated high glucose (HG)-induced pyroptosis and NLRP3 inflammasome activation along with enhanced Sirt1 and AMPK activation. After blockade of Sirt1 and AMPK signaling, the protective effect of liraglutide was restrained. Notably, EX 527 abolished the stimulatory effect of liraglutide on Sirt1 and AMPK signaling, whereas compound C blunted AMPK signaling without affecting Sirt1 signaling.

CONCLUSION

Liraglutide may protect against myocardial damage by activating the Sirt1/AMPK signaling pathways to inhibit cellular pyroptosis in DM.

Protective Effects of Huangqi Shengmai Yin on Type 1 Diabetes-Induced Cardiomyopathy by Improving Myocardial Lipid Metabolism

Diabetic cardiomyopathy (DCM) is one of the many complications of diabetes. DCM leads to cardiac insufficiency and myocardial remodeling and is the main cause of death in diabetic patients. Abnormal lipid metabolism plays an important role in the occurrence and development of DCM. Huangqi Shengmai Yin (HSY) has previously been shown to alleviate signs of heart disease. Here, we investigated whether HSY could improve cardiomyopathy caused by type 1 diabetes mellitus (T1DM) and improve abnormal lipid metabolism in the diabetic heart. Streptozotocin (STZ) was used to establish the T1DM mouse model, and T1DM mice were subsequently treated with HSY for eight weeks. The changes in the cardiac conduction system, histopathology, blood myocardial injury indices, and lipid content and expression of proteins related to lipid metabolism were evaluated. Our results showed that HSY could improve electrocardiogram; decrease the serum levels of CK-MB, LDH, and BNP; alleviate histopathological changes in cardiac tissue; and decrease myocardial lipid content in T1DM mice. These results indicate that HSY has a protective effect against T1DM-induced myocardial injury in mice and that this effect may be related to the improvement in myocardial lipid metabolism.

Comparative evaluation of metformin and liraglutide cardioprotective effect in rats with impaired glucose tolerance

Impaired glucose tolerance (IGT) increases cardiovascular risk and can enlarge myocardial infarction (MI) incidence and severity. There is lack of information about cardioprotective potential of glucose-lowering drugs in IGT. We aimed to evaluate the sustainability of myocardium to ischemia-reperfusion injury in diabetic and IGT rats and to study cardioprotective action of metformin and liraglutide. Type 2 diabetes mellitus (DM) and IGT were modelled in Wistar rats by high-fat diet and streptozotocin + nicotinamide. 4 weeks after rats were divided into 4 groups: DM (without treatment) (n = 4), IGT (without treatment) (n = 4), IGT + MET (metformin 200 mg/kg per os once daily 8 weeks) (n = 4), IGT + LIRA (liraglutide 0.06 mg/kg s.c. once daily for 8 weeks) (n = 4). Control (n = 6) and high-fat diet (n = 8) groups were made for comparison. After 8 weeks ischemia-reperfusion injury in isolated hearts was performed. Hemodynamic parameters were evaluated and MI size was measured by staining of myocardium slices in triphenyltetrazolium chloride solution. Blood glucose level was measured during the study. Both IGT and DM led to similar worsening of hemodynamic parameters during ischemia-reperfusion period, in comparison with control group. MI size in IGT (56.76 (51.58; 69.07) %) and DM (57.26 (45.51; 70.08) %) groups was significantly larger than that in control group (42.98 (33.26; 61.84) %) and did not differ between each other. MI size in high-fat diet group (56.98 (47.11; 62.83) %) was as large as in IGT and DM groups (p > 0.05). MI size in IGT + MET (42.11 (38.08; 71.96) %) and IGT + LIRA (42.50 (31.37; 60.40) %) was smaller than in both DM and IGT groups (p < 0.05 for multiple comparison). Myocardium damage size did not differ in IGT + MET and IGT + LIRA groups (p >  0.05). Only LIRA, but not MET administration to IGT rats led to ischemic contracture reduction. Glycemic control was similarly satisfactory in IGT, IGT + MET, IGT + LIRA groups. Thus, IGT and DM have similarly pronounced negative influence on hemodynamics and MI size in rat transient global ischemia ex vivo. Obesity development also has negative impact on the MI size. Both MET and LIRA have infarct-limiting effect independent on their influence on glucose level. LIRA, but not MET, diminishes ischemic contracture in IGT rats.

Liraglutide Inhibits Osteoclastogenesis and Improves Bone Loss by Downregulating Trem2 in Female Type 1 Diabetic Mice: Findings From Transcriptomics

BACKGROUND

The mechanisms of bone fragility in type 1 diabetes (T1D) are not fully understood. Whether glucagon-like peptide-1 receptor (GLP-1R) agonists could improve bone quality in T1D context also remains elusive.

AIMS

We aimed to explore the possible mechanisms of bone loss in T1D and clarify whether liraglutide has effects on bone quality of T1D mice using transcriptomics.

METHODS

Female streptozotocin-induced diabetic C57BL/6J mice were randomly divided into four groups and received the following treatments daily for 8 weeks: saline as controls, insulin, liraglutide, and liraglutide combined with insulin. These groups were also compared with non-STZ-treated normal glucose tolerance (NGT) group. Trunk blood and bone tissues were collected for analysis. Three tibia from each of the NGT, saline-treated, and liraglutide-treated groups were randomly selected for transcriptomics.

RESULTS

Compared with NGT mice, saline-treated T1D mice manifested markedly hyperglycemia and weight loss, and micro-CT revealed significantly lower bone mineral density (BMD) and deficient microarchitectures in tibias. Eight weeks of treatment with liraglutide alone or combined with insulin rescued the decreased BMD and partly corrected the compromised trabecular microarchitectures. Transcriptomics analysis showed there were 789 differentially expressed genes mainly mapped to osteoclastogenesis and inflammation pathways. The RT-qPCR verified that the gene expression of Trem2, Nfatc1, Trap, and Ctsk were significantly increased in the tibia of T1D compared with those in the NGT group. Liraglutide treatment alone or combined with insulin could effectively suppress osteoclastogenesis by downregulating the gene expression of Trem2, Nfatc1, Ctsk, and Trap.

CONCLUSIONS

Taken together, increased osteoclastogenesis with upregulated expression of Trem2 played an important role in bone loss of T1D mice. Liraglutide provided protective effects on bone loss in T1D mice by suppressing osteoclastogenesis.

Identification of key candidate genes and pathways revealing the protective effect of liraglutide on diabetic cardiac muscle by integrated bioinformatics analysis

Background

Diabetes mellitus is becoming a significant health problem with the International Diabetes Federation (IDF) expecting a startling 642 million diabetes patients by 2040. Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, is reported to protect against diabetic cardiomyopathy by binding to the receptor, GLP-1R. However, the underlying mechanism has yet to be clarified. This study aimed to investigate the underlying mechanisms and the effects of liraglutide on diabetic patient's cardiac muscles.

Methods

GSE102194 genetic expression profiles were extracted from the Gene Expression Omnibus (GEO) database. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were carried out. Next, Cytoscape software was used to construct the protein-protein interaction (PPI) network of the differentially expressed genes (DEGs). DEGs were mapped onto a protein-protein interaction (PPI) network that comprised 249 nodes and 776 edges.

Results

A total of 520 DEGs were discovered, including 159 down-regulated genes and 361 up-regulated genes. DEGs that were upregulated were notably enriched in biological processes (BP) such as muscle system process, muscle system process, muscle structure development and anatomical structure morphogenesis while DEGs that were downregulated were rich in detection of chemical stimulus and neurological system process. KEGG pathway analysis showed the up-regulated DEGs were enriched in adrenergic signaling for cardiomyocytes, dopaminergic synapse, and circadian entrainment, while the down-regulated DEGs were enriched for factory transduction in 249 of the 520 tested samples. The modular analysis identified 4 modules that participated in some pathways associated with cardiac muscle contraction, hypertrophic cardiomyopathy (HCM), and MAPK signaling pathway.

Conclusions

Our data showed that Glp-1 could decrease the protein expression of p38, JNK, ERK1/2, and MARS proteins induced by high glucose (22 mM, 72 h). This study highlights the potential physiological processes that take place in diabetic cardiac muscles exposed to liraglutide. Our findings elucidated the regulatory network in diabetic cardiomyopathy and might provide a novel diagnostic and therapeutic target for diabetic cardiomyopathy.

Identification of Potential Therapeutic Targets and Pathways of Liraglutide Against Type 2 Diabetes Mellitus (T2DM) Based on Long Non-Coding RNA (lncRNA) Sequencing

BACKGROUND The aim of this study was to explore the potential therapeutic targets and pathways of liraglutide against type 2 diabetes mellitus (T2DM) in streptozotocin-induced diabetic rats based on lncRNA sequencing. MATERIAL AND METHODS Male Wistar rats were randomly divided into 3 groups: the control group (n=10), the T2DM model group (high-sugar and high-fat diet, and streptozotocin-induced, n=11), and the liraglutide group (model plus liraglutide, n=10). After 8 weeks of drug treatment, lncRNA sequencing was used to identify the lncRNA therapeutic targets and their related protein-coding genes of liraglutide against T2DM, which were further studied by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to determine the major biological processes and pathways involved in the action of liraglutide treatment. Lastly, several lncRNA targets were randomly detected based on quantitative real-time polymerase chain reaction (QRT-PCR) to verify the accuracy of sequencing results. RESULTS A total of 104 lncRNA targets of liraglutide against T2DM were screened, with 27 upregulated and 77 downregulated, including NONRATT030354.2, MSTRG.1456.6, and NONRATT011758.2. The major biological processes involved were glucose and lipid metabolism and amino acid metabolism. Liraglutide had a therapeutic effect in T2DM, mainly through the Wnt, PPAR, amino acid metabolism signaling, mTOR, and lipid metabolism-related pathways. CONCLUSIONS In this study, we screened 104 lncRNA therapeutic targets and several signaling pathways (Wnt, PPAR, amino acid metabolism signaling pathway, mTOR, and lipid metabolism-related pathways) of liraglutide against T2DM based on lncRNA sequencing.

Liraglutide attenuates gefitinib-induced cardiotoxicity and promotes cardioprotection through the regulation of MAPK/NF-κB signaling pathways

Gefitinib is an effective treatment for patients with locally advanced non-small cell lung cancer. However, it is associated with cardiotoxicity that can limit its clinical use. Liraglutide, a glucagon-like peptide 1 receptor agonist, showed potent cardioprotective effects with the mechanism is yet to be elucidated. Therefore, this study aimed to determine the efficiency of liraglutide in protecting the heart from damage induced by gefitinib. Adult male Wistar rats were randomly divided into control group, liraglutide group (200 µg/kg by i.p. injection), gefitinib group (30 mg/kg orally) and liraglutide plus gefitinib group. After 28 days, blood and tissue samples were collected for histopathological, biochemical, gene and protein analysis. We demonstrated that gefitinib treatment (30 mg/kg) resulted in cardiac damage as evidenced by histopathological studies. Furthermore, serum Creatine kinase-MB (CK-MB), N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac Troponin-I (cTnI) were markedly elevated in gefitinib group. Pretreatment with liraglutide (200 µg/kg), however, restored the elevation in serum markers and diminished gefitinib-induced cardiac damage. Moreover, liraglutide improved the gene and protein levels of anti-oxidant (superoxide dismutase) and decreased the oxidative stress marker (NF-κB). Mechanistically, liraglutide offered protection through upregulation of the survival kinases (ERK1/2 and Akt) and downregulation of stress-activated kinases (JNK and P38). In this study, we provide evidence that liraglutide protects the heart from gefitinib-induced cardiac damage through its anti-oxidant property and through the activation of survival kinases.

Icariin treatment reduces blood glucose levels in type 2 diabetic rats and protects pancreatic function

Icariin, a flavonoid isolated from traditional oriental herbal medicines, has been demonstrated to exhibit several health benefits in animal models and in humans. The aim of the present study was to investigate the effect of Icariin on hyperglycemia in type 2 diabetes mellitus (T2DM) in rats. A model of diabetes was established in 50 Sprague Dawley rats using a high-sugar and high-fat diet and peritoneal injection of streptozotocin. Diabetic rats were divided into five groups: Diabetic control; metformin; and rats treated with three different doses of Icariin, 5, 10 and 20 mg/kg. Body weight and blood glucose levels were measured, and serum adiponectin levels, expression of phospho-AMP mediated protein kinase (p-AMPK) and glucose transporter isoform 4 (GLUT-4) were measured using ELISA, Realtime PCR and western blotting, respectively. Diabetic rats without drug treatment exhibited reduced body weight, increased blood glucose levels and decreased the number of islets. In T2DM rats treated with 10 or 20 mg/kg Icariin, the blood glucose levels were reduced, whereas serum adiponectin levels were not affected. Additionally, the mRNA and protein expression levels of p-AMPK and GLUT-4 protein were increased in the T2DM rats treated with Icariin. In conclusion, in the diabetes rat model, Icariin alleviated the severity of diabetes, and the effects may be associated with reduction of hyperglycemia by activating an AMPK/GLUT-4 pathway.

Liraglutide Improves Non-Alcoholic Fatty Liver Disease In Diabetic Mice By Modulating Inflammatory Signaling Pathways

BACKGROUND

Many chronic metabolic diseases, such as obesity and type 2 diabetes (T2DM), are closely related to a chronic low-grade inflammatory state in tissues. The high prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with T2DM is related to the role of inflammation in the disease. In this study, we investigated the role of liraglutide in improving lipid metabolism disorders and preventing their progression to NAFLD by modulating inflammatory signaling pathways, thereby providing new treatment options for NAFLD.

METHODS

We designed a 2×2 factorial analysis experiment. A mouse model of NAFLD with T2DM was established by feeding the animals a high-fat diet (HFD). The NAFLD mice with HFD-induced diabetes were treated with liraglutide for 10 weeks. Hematoxylin and eosin staining, Oil Red O staining and electron microscopy were used to observe the accumulation of triglycerides in the liver. RT-PCR and Western blotting were used to analyze the expression of α-SMA, IL-1β, TNF-α, NF-κB and the NF-κB inhibitory protein IκB in the liver at the gene and protein levels, respectively.

RESULTS

Liraglutide reduced the body weight and fasting blood glucose levels of HFD-fed mice. The expression of α-SMA, IL-1β, TNF-α, and NF-κB in the liver of HFD-fed mice was increased at the mRNA and protein levels, but liraglutide treatment decreased the expression of these molecules. The expression of IκB in the liver decreased at the mRNA and protein levels but was upregulated after liraglutide treatment.

CONCLUSION

Based on the current findings, liraglutide can significantly improve hepatic steatosis, primarily by downregulating the expression of inflammatory signaling mediators in the TNF-α pathway.

Favorable outcomes of metformin on coronary microvasculature in experimental diabetic cardiomyopathy

Although metformin is widely prescribed in diabetes, its use with associated cardiac dysfunction remains debatable. In the current study, we investigated the effect of metformin on coronary microvasculature in experimental diabetic cardiomyopathy (DCM) induced by streptozotocin. Administration of metformin after induction of DCM, reversed almost all cardiomyocyte degenerative changes induced by DCM. Metformin diminished the significantly increased (p < 0.05) collagen deposited in the DCM. In addition metformin had improved the density of the significantly decreased arteriolar (αSMA⁺) and capillary (CD31⁺) coronary microvasculature compared to that of the DCM and non-diabetics (ND) with downregulation of the significantly increased expression (p < 0.05) of COL-I, III, TGF-β, CTGF, ICAM and VCAM genes. Therefore metformin may be beneficial in limiting the fibrotic and the vascular remodeling occurring in DCM at the genetic as well as the structural levels.