Background: Hypertriglyceridemia has serious health risks such as cardiovascular disease, type 2 diabetes mellitus, nephropathy, and others. Fenofibrate is an effective hypolipidemic drug, but its benefits for ameliorating disorders associated with hypertriglyceridemia failed to be proven in clinical trials. Methods: To search for possible causes of this situation and possibilities of their favorable influence, we tested the effect of FF monotherapy and the combination of fenofibrate with silymarin on metabolic disorders in a unique model of hereditary hypertriglyceridemic rats (HHTg). Results: Fenofibrate treatment (100 mg/kg BW/day for four weeks) significantly decreased serum levels of triglyceride, (-77%) and free fatty acids (-29%), the hepatic accumulation of triglycerides, and the expression of genes encoding transcription factors involved in lipid metabolism (Srebf2, Nr1h4. Rxrα, and Slco1a1). In contrast, the hypertriglyceridemia-induced ectopic storage of lipids in muscles, the heart, and kidneys reduced glucose utilization in muscles and was not affected. In addition, fenofibrate reduced the activity of the antioxidant system, including Nrf2 expression (-35%) and increased lipoperoxidation in the liver and, to a lesser extent, in the kidneys and heart. Adding silymarin (micronized form, 600 mg/kg BW/day) to fenofibrate therapy increased the synthesis of glycogen in muscles, (+36%) and reduced hyperinsulinemia (-34%). In the liver, it increased the activity of the antioxidant system, including PON-1 activity and Nrf2 expression, and reduced the formation of lipoperoxides. The beneficial effect of combination therapy on the parameters of oxidative stress and lipoperoxidation was also observed, to a lesser extent, in the heart and kidneys. Conclusions: Our results suggest the potential beneficial use of the combination of FF with SLM in the treatment of hypertriglyceridemia-induced metabolic disorders.

• Klíčová slova
• fenofibrate, glycogen synthesis, insulin resistance, metabolic syndrome, oxidative stress, reesterification of fatty acids, silymarin, triglycerides,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The activity of perivascular adipose tissue (PVAT), a specific deposit of adipose tissue surrounding blood vessels, could contribute to sex differences in vascular tone control, particularly in dyslipidemic disorders; however, the mutual associations remain unclear. This study aimed to evaluate the relationships among sex, PVAT and vascular function in Wistar and hereditary hypertriglyceridemic (HTG) rats. Vasoactive responses of the isolated thoracic aorta with preserved or removed PVAT were compared in adult male and female Wistar and HTG rats, and the roles of nitric oxide (NO), hydrogen sulfide (H2S), cyclooxygenase (COX) and inflammatory signaling in vascular function were monitored in females. RESULTS: HTG rats were hypertensive, but females less than males. Increased 2-h glycemia was observed in HTG rats regardless of sex; however, HTG females exhibited better glucose utilization than males did. Females, independent of strain, had better preserved endothelial function than males did. PVAT inhibited endothelium-dependent relaxation in all the rats except HTG females. In HTG males, pathologically increased aortic contractility was noted; however, in HTG females, the contractile responses were lower, thus approaching physiological levels despite the pro-contractile action of COX products. In HTG females, NO contributed to endothelial function to a lesser extent than it did in controls, but the presence of PVAT eliminated this difference, which corresponded with increased NO synthase activity. Although increased protein expression of several proinflammatory factors (TNFα, IL-6, iNOS, and NfκB) was confirmed in the aortic and PVAT tissue of HTG females, the protein expression of factors regulating the adhesion and infiltration of monocytes (ICAM-1 and MCP-1) was decreased in PVAT. Moreover, in HTG females, unlike in controls, H2S produced by PVAT did not inhibit endothelial relaxation, and regardless of PVAT, endogenous H2S had beneficial anticontractile effects, which were associated with increased protein expression of H2S-producing enzymes in both aortic and PVAT tissues. CONCLUSIONS: Despite increased inflammation and the pathological impact of cyclooxygenase signaling in female HTG rats, protective vasoactive mechanisms associated with milder hypertension and improved endothelial function and contractility linked to PVAT activity were triggered. Sulfide and nitroso signaling represent important compensatory vasoactive mechanisms against hypertriglyceridemia-associated metabolic disorders and may be promising therapeutic targets in prediabetic females.

• Klíčová slova
• Hereditary hypertriglyceridaemic rats, Hydrogen sulfide, Nitric oxide, Perivascular adipose tissue, Sex,
• MeSH
• aorta thoracica patofyziologie   MeSH
• cévní endotel patofyziologie   MeSH
• krysa rodu Rattus MeSH
• oxid dusnatý * metabolismus   MeSH
• potkani Wistar * MeSH
• prediabetes * patofyziologie   metabolismus   MeSH
• sexuální faktory MeSH
• signální transdukce * fyziologie   MeSH
• sulfan * metabolismus   MeSH
• tuková tkáň metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid dusnatý * MeSH
• sulfan * MeSH

BACKGROUND AND AIMS: Recent studies suggest that empagliflozin reduces total and cardiovascular mortality in both diabetic and nondiabetic subjects. Although the exact mechanism is unclear, it is understood to positively affect myocardial energetics, including the metabolism of ketone bodies, lipids, and fatty acids. In this study, we compared empagliflozin effects on lipid metabolism in the heart and liver in a prediabetic rat model with severe dyslipidemia. MATERIALS AND METHODS: Wistar rats served as the control group, while hereditary hypertriglyceridemic (HHTg) rats were used as a nonobese, prediabetic model. Rats were treated with or without empagliflozin at a dose of 10 mg/kg body weight (BW) for 8 weeks. RESULTS: In HHTg rats, empagliflozin decreased body weight and adiposity, improved glucose tolerance, and decreased serum triacylglycerols (TAGs) (p < 0.001). Empagliflozin decreased the activity and gene expression of the lipogenic enzyme SCD-1 (p < 0.001) in the myocardium, which may have led to a decrease in the ectopic accumulation of TAGs and lipotoxic diacylglycerols and lysophosphatidylcholines (p < 0.001). Changes in the myocardial phosphatidylcholine/phosphatidylethanolamine ratio (p < 0.01) and in the fatty acid profile of myocardial phospholipids may have contributed to the antifibrotic effects of empagliflozin. The anti-inflammatory effects of empagliflozin were evidenced by an increased IL-10/TNFα ratio (p < 0.001), a marked decrease in arachidonic acid metabolites (20-HETE, p < 0.001), and an increase in PUFA metabolites (14,15-EETs, p < 0.001) in the myocardium. However, empagliflozin did not significantly affect either the concentration or utilization of ketone bodies. In the liver, empagliflozin decreased lipogenesis and the accumulation of TAGs and lipotoxic intermediates. Its effect on arachidonic acid metabolites and alterations in n-3 PUFA metabolism was less pronounced than in the myocardium. CONCLUSION: Our findings suggest that empagliflozin treatment in the heart and liver reduced the accumulation of neutral lipids and lipotoxic intermediates and altered the metabolism of n-3 PUFA. In the heart, empagliflozin altered arachidonic acid metabolism, which is likely associated with the anti-inflammatory and antifibrotic effects of the drug. We assume that these alterations in lipid metabolism contribute to the cardioprotective effects of empagliflozin in prediabetic states with severe dyslipidemia.

• Klíčová slova
• SGLT2 inhibitors, arachidonic acid, cardiovascular disease, empagliflozin, inflammation, ketone body, lipid metabolism,
• Publikační typ
• časopisecké články MeSH

Menopause brings about profound physiological changes, including the acceleration of insulin resistance and other abnormalities, in which adipose tissue can play a significant role. This study analyzed the effect of ovariectomy and estradiol substitution on the metabolic parameters and transcriptomic profile of adipose tissue in prediabetic females of hereditary hypertriglyceridemic rats (HHTgs). The HHTgs underwent ovariectomy (OVX) or sham surgery (SHAM), and half of the OVX group received 17β-estradiol (OVX+E2) post-surgery. Ovariectomy resulted in weight gain, an impaired glucose tolerance, ectopic triglyceride (TG) deposition, and insulin resistance exemplified by impaired glycogenesis and lipogenesis. Estradiol alleviated some of the disorders associated with ovariectomy; in particular, it improved insulin sensitivity and reduced TG deposition. A transcriptomic analysis of perimetrial adipose tissue revealed 809 differentially expressed transcripts in the OVX vs. SHAM groups, mostly pertaining to the regulation of lipid and glucose metabolism, and oxidative stress. Estradiol substitution affected 1049 transcripts with overrepresentation in the signaling pathways of lipid metabolism. The principal component and hierarchical clustering analyses of transcriptome shifts corroborated the metabolic data, showing a closer resemblance between the OVX+E2 and SHAM groups compared to the OVX group. Changes in the adipose tissue transcriptome may contribute to metabolic abnormalities accompanying ovariectomy-induced menopause in HHTg females. Estradiol substitution may partially mitigate some of these disorders.

• Klíčová slova
• estradiol substitution, hereditary hypertriglyceridemic rat, insulin sensitivity, ovariectomy, perimetrial adipose tissue, transcriptomics,
• Publikační typ
• časopisecké články MeSH

The combination of plant-derived compounds with anti-diabetic agents to manage hepatic steatosis closely associated with diabetes mellitus may be a new therapeutic approach. Silymarin, a complex of bioactive substances extracted from Silybum marianum, evinces an antioxidative, anti-inflammatory, and hepatoprotective activity. In this study, we investigated whether metformin (300 mg/kg/day for four weeks) supplemented with micronized silymarin (600 mg/kg/day) would be effective in mitigating fatty liver disturbances in a pre-diabetic model with dyslipidemia. Compared with metformin monotherapy, the metformin-silymarin combination reduced the content of neutral lipids (TAGs) and lipotoxic intermediates (DAGs). Hepatic gene expression of enzymes and transcription factors involved in lipogenesis (Scd-1, Srebp1, Pparγ, and Nr1h) and fatty acid oxidation (Pparα) were positively affected, with hepatic lipid accumulation reducing as a result. Combination therapy also positively influenced arachidonic acid metabolism, including its metabolites (14,15-EET and 20-HETE), mitigating inflammation and oxidative stress. Changes in the gene expression of cytochrome P450 enzymes, particularly Cyp4A, can improve hepatic lipid metabolism and moderate inflammation. All these effects play a significant role in ameliorating insulin resistance, a principal background of liver steatosis closely linked to T2DM. The additive effect of silymarin in metformin therapy can mitigate fatty liver development in the pre-diabetic state and before the onset of diabetes.

• Klíčová slova
• combination therapy, liver steatosis, metformin, pre-diabetes, silymarin,
• Publikační typ
• časopisecké články MeSH

Metformin can reduce cardiovascular risk independent of glycemic control. The mechanisms behind its non-glycemic benefits, which include decreased energy intake, lower blood pressure and improved lipid and fatty acid metabolism, are not fully understood. In our study, metformin treatment reduced myocardial accumulation of neutral lipids-triglycerides, cholesteryl esters and the lipotoxic intermediates-diacylglycerols and lysophosphatidylcholines in a prediabetic rat model (p < 0.001). We observed an association between decreased gene expression and SCD-1 activity (p < 0.05). In addition, metformin markedly improved phospholipid fatty acid composition in the myocardium, represented by decreased SFA profiles and increased n3-PUFA profiles. Known for its cardioprotective and anti-inflammatory properties, metformin also had positive effects on arachidonic acid metabolism and CYP-derived arachidonic acid metabolites. We also found an association between increased gene expression of the cardiac isoform CYP2c with increased 14,15-EET (p < 0.05) and markedly reduced 20-HETE (p < 0.001) in the myocardium. Based on these results, we conclude that metformin treatment reduces the lipogenic enzyme SCD-1 and the accumulation of the lipotoxic intermediates diacylglycerols and lysophosphatidylcholine. Increased CYP2c gene expression and beneficial effects on CYP-derived arachidonic acid metabolites in the myocardium can also be involved in cardioprotective effect of metformin.

• Klíčová slova
• arachidonic acid, cytochrome P450, fatty acid profile, lipotoxic intermediates, metformin, myocardial function, myocardial phospholipids, stearoyl-CoA desaturase,
• MeSH
• bazální metabolismus účinky léků   MeSH
• biologické markery krev   MeSH
• desaturasy mastných kyselin metabolismus   MeSH
• hyperlipoproteinemie typ IV farmakoterapie   metabolismus   MeSH
• hypoglykemika farmakologie   MeSH
• kardiotonika farmakologie   MeSH
• krysa rodu Rattus MeSH
• kyselina arachidonová metabolismus   MeSH
• mediátory zánětu krev   MeSH
• metabolismus lipidů účinky léků   MeSH
• metformin farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• myokard metabolismus   MeSH
• potkani Wistar MeSH
• prediabetes farmakoterapie   metabolismus   MeSH
• rizikové faktory MeSH
• srdce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH
• desaturasy mastných kyselin MeSH
• hypoglykemika MeSH
• kardiotonika MeSH
• kyselina arachidonová MeSH
• mediátory zánětu MeSH
• metformin MeSH

The aim of this study was to evaluate the mutual relationship among perivascular adipose tissue (PVAT) and endogenous and exogenous H2S in vasoactive responses of isolated arteries from adult normotensive (Wistar) rats and hypertriglyceridemic (HTG) rats, which are a nonobese model of metabolic syndrome. In HTG rats, mild hypertension was associated with glucose intolerance, dyslipidemia, increased amount of retroperitoneal fat, increased arterial contractility, and endothelial dysfunction associated with arterial wall injury, which was accompanied by decreased nitric oxide (NO)-synthase activity, increased expression of H2S producing enzyme, and an altered oxidative state. In HTG, endogenous H2S participated in the inhibition of endothelium-dependent vasorelaxation regardless of PVAT presence; on the other hand, aortas with preserved PVAT revealed a stronger anticontractile effect mediated at least partially by H2S. Although we observed a higher vasorelaxation induced by exogenous H2S donor in HTG rats than in Wistar rats, intact PVAT subtilized this effect. We demonstrate that, in HTG rats, endogenous H2S could manifest a dual effect depending on the type of triggered signaling pathway. H2S within the arterial wall contributes to endothelial dysfunction. On the other hand, PVAT of HTG is endowed with compensatory vasoactive mechanisms, which include stronger anti-contractile action of H2S. Nevertheless, the possible negative impact of PVAT during hypertriglyceridemia on the activity of exogenous H2S donors needs to be taken into consideration.

• Klíčová slova
• H2S, HTG, Wistar, isolated artery, metabolic syndrome, perivascular adipose tissue,
• MeSH
• aorta thoracica patofyziologie   MeSH
• cévní endotel patofyziologie   MeSH
• cystathionin-gama-lyasa metabolismus   MeSH
• hypertriglyceridemie metabolismus   MeSH
• krysa rodu Rattus MeSH
• metabolický syndrom metabolismus   patofyziologie   MeSH
• modely nemocí na zvířatech MeSH
• noradrenalin farmakologie   MeSH
• oxidace-redukce MeSH
• potkani Wistar MeSH
• signální transdukce * MeSH
• superoxiddismutasa metabolismus   MeSH
• superoxidy metabolismus   MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• tuková tkáň metabolismus   MeSH
• vazodilatace fyziologie   MeSH
• vazokonstrikce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cystathionin-gama-lyasa MeSH
• noradrenalin MeSH
• superoxiddismutasa MeSH
• superoxidy MeSH
• synthasa oxidu dusnatého, typ III MeSH