Inulin ameliorates metabolic syndrome in high-fat diet-fed mice by regulating gut microbiota and bile acid excretion.

Background: Inulin is a natural plant extract that improves metabolic syndrome by modulating the gut microbiota. Changes in the gut microbiota may affect intestinal bile acids. We suggest that inulin may improve metabolism by inducing bile acid excretion by gut microbes. Methods: Male C57/BL mice were fed either a high-fat diet (60% calories) or a regular diet for 16 weeks, with oral inulin (10% w/w). At the end of the experiment, the gene expression levels (FGF15, CD36, Srebp-1c, FASN, and ACC) in the liver and intestines, as well as the serum levels of triglycerides (TGs), low-density lipoprotein (LDL) cholesterol, total cholesterol, and free fatty acids, were collected. The expression of FGF15 was examined using Western blot analysis. The fat distribution in the liver and groin was detected by oil red and hematoxylin and eosin staining. Simultaneously, the levels of serum inflammatory factors (alanine aminotransferase and aspartate aminotransferase) were detected to explore the side effects of inulin. Results: Inulin significantly improved glucose tolerance and insulin sensitivity, and decreased body weight and serum TG and LDL levels, in mice fed normal diet. Furthermore, inulin increased the α-diversity of the gut microbiota and increased the fecal bile acid and TG excretion in inulin-treated mice. In addition, inulin significantly reduced lipid accumulation in liver and inguinal fat, white fat weight, and hepatic steatosis. Western blot analysis showed that inulin reduced the expression of FGF15, a bile acid reabsorption protein. Conclusion: Inulin ameliorates the glucose and lipid metabolic phenotypes of mice fed a normal diet, including decreased intestinal lipid absorption, increased glucose tolerance, increased insulin sensitivity, and decreased body weight. These changes may be caused by an increase in bile acid excretion resulting from changes in the gut microbiota that affect intestinal lipid absorption.

Sulfosuccinimidyl oleate ameliorates the high-fat diet-induced obesity syndrome by reducing intestinal and hepatic absorption.

Background: A high-fat Western diet is a risk factor for obesity and steatosis. Reducing intestinal absorption of a high-fat diet (HFD) is a feasible strategy to control obesity. Sulfosuccinimidyl oleate (SSO) inhibits intestinal fatty acid transport. Therefore, the aim of this study was to investigate the effects of SSO on HFD-induced glucose and lipid metabolism in mice and its possible underlying mechanisms. Methods: Male C57/BL were fed a HFD (60% calories) for 12 weeks and were administered an oral dose of SSO (50 mg/kg/day). The expression of lipid absorption genes (CD36, MTTP, and DGAT1) and the serum levels of triglycerides (TGs), total cholesterol (TC), and free fatty acids (FFAs) were detected. Lipid distribution in the liver was detected by oil red and hematoxylin and eosin staining. In addition, serum levels of inflammatory factors, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured to detect side effects. Results: SSO was effective in the treatment of obesity and metabolic syndrome induced by HFD in mice. It attenuated the assembly of intestinal epithelial chylomicrons by inhibiting intestinal epithelial transport and absorption of fatty acids, thereby reducing the gene expression levels of MTTP and DGAT1, resulting in decreased plasma TG and FFA levels. At the same time, it inhibited the transport of fatty acids in the liver and improved the steatosis induced by a HFD. The results of oil red staining showed that SSO treatment can reduce lipid accumulation in the liver by 70%, with no drug-induced liver injury detected on the basis of interleukin-6, C-reactive protein, ALT, and AST levels. In addition, SSO treatment significantly improved insulin resistance, decreased fasting blood glucose levels, and improved glucose tolerance in HFD-fed mice. Conclusion: SSO is effective in the treatment of obesity and metabolic syndrome induced by a HFD in mice. SSO reduces intestinal fatty acid absorption by reducing the inhibition of intestinal CD36 expression, followed by decreased TG and FFA levels, which attenuates HFD-induced fatty liver.

Maslinic Acid Ameliorates Myocardial Ischemia Reperfusion Injury-Induced Oxidative Stress via Activating Nrf2 and Inhibiting NF-[Formula: see text]B Pathways.

Maslinic acid (MA) is a pentacyclic triterpene obtained from the peel of olives that exhibits anti-inflammatory and antioxidant properties in several conditions. Our previous study revealed that MA exerted a cardioprotective effect by repressing inflammation and apoptosis during myocardial ischemia-reperfusion injury (MIRI). However, data regarding the antioxidative effects of MA on MIRI remains limited. This study aims to elucidate the antioxidative roles and underlying mechanisms of MA on MIRI. The left anterior descending coronary artery of rats was subjected to ligate for the induction of the ischemia/reperfusion (I/R) model and the H9c2 cells were exposed to hydrogen peroxide (H2O2) to mimic oxidative stress. The results showed that MA reduced the I/R-induced myocardial injury and H2O2-induced cardiomyocyte death in a dose-dependent manner. Meanwhile, MA increased the activities of glutathione and superoxide dismutase both in vitro and in vivo while lowering the levels of reactive oxygen species and malondialdehyde. Mechanistically, MA could facilitate Nrf2 nuclear translocation, activate the Nrf2/HO-1 signaling pathway, and repress the NF-[Formula: see text]B signaling pathway both in I/R- and H2O2-induced oxidative stress. Besides, MA promoted the intranuclear Nrf2 and HO-1 expression, which could in part be improved by QNZ (NF-[Formula: see text]B inhibitor) in H2O2-insulted cells. Conversely, MA markedly reduced the intranuclear NF-[Formula: see text]B p65 and TNF-[Formula: see text] expression, which could be partially abolished by ML385 (Nrf2 inhibitor). Overall, our results indicate that MA, in a dose-dependent manner, mitigated I/R-induced myocardial injury and oxidative stress via activating the Nrf2/HO-1 pathway and inhibiting NF-[Formula: see text]B activation. Furthermore, MA exerts its cardioprotective effect through regulating the crosstalk between the Nrf2 and NF-[Formula: see text]B pathways.

Maslinic Acid Attenuates Ischemia/Reperfusion Injury-Induced Myocardial Inflammation and Apoptosis by Regulating HMGB1-TLR4 Axis.

Aims: The inflammatory response and apoptosis are the major pathological features of myocardial ischemia/reperfusion injury (MI/RI). Maslinic acid (MA), a natural pentacyclic triterpene with various bioactivities, plays critical roles in the multiple cellular biological processes, but its protective effects on the pathophysiological processes of MI/RI have not been extensively investigated. Our study aimed to determine whether MA treatment alleviate ischemia/reperfusion (I/R)-induced myocardial inflammation and apoptosis both in vitro and in vivo, and further reveal the underlying mechanisms. Methods and results: An MI/RI rat model was successfully established by ligating the left anterior descending coronary artery and H9c2 cells were exposed to hypoxia/reoxygenation (H/R) to mimic I/R injury. In addition, prior to H/R stimulation or myocardial I/R operation, the H9c2 cells or rats were treated with varying concentrations of MA or vehicle for 24 h and two consecutive days, respectively. In this study, our results showed that MA could obviously increase the cell viability and decrease the cardiac enzymes release after H/R in vitro. MA could significantly improve the H/R-induced cardiomyocyte injury and I/R-induced myocardial injury in a dose-dependent manner. Moreover, MA suppressed the expression of inflammatory cytokines (tumor necrosis factor alpha [TNF-α, interleukin-1ß [IL-1ß and interleukin-6 [IL-6]) and the expressions of apoptosis-related proteins (cleaved caspase-3 and Bax) as well as increased the levels of anti-apoptotic protein Bcl-2 expression both in vitro and in vivo. Mechanistically, MA significantly inhibited nuclear translocation of nuclear factor-κB (NF-κB) p65 after H/R via regulating high mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4) axis. Conclusion: Taken together, MA treatment may alleviate MI/RI by suppressing both the inflammation and apoptosis in a dose-dependent manner, and the cardioprotective effect of MA may be partly attributable to the inactivation of HMGB1/TLR4/NF-κB pathway, which offers a new therapeutic strategy for MI/RI.

Targeting mitochondria-inflammation circle by renal denervation reduces atheroprone endothelial phenotypes and atherosclerosis.

OBJECTIVE: The disruption of mitochondrial redox homeostasis in endothelial cells (ECs) can cause chronic inflammation, a substantial contributor to the development of atherosclerosis. Chronic sympathetic hyperactivity can enhance oxidative stress to induce endothelial dysfunction. We determined if renal denervation (RDN), the strategy reducing sympathetic tone, can protect ECs by ameliorating mitochondrial reactive oxygen species (ROS)-induced inflammation to reduce atherosclerosis. METHODS AND RESULTS: ApoE deficient (ApoE-/-) mice were conducted RDN or sham operation before 20-week high-fat diet feeding. Atherosclerosis, EC phenotype and mitochondrial morphology were determined. In vitro, human arterial ECs were treated with norepinephrine to determine the mechanisms for RDN-inhibited endothelial inflammation. RDN reduced atherosclerosis, EC mitochondrial oxidative stress and inflammation. Mechanistically, the chronic sympathetic hyperactivity increased circulating norepinephrine and mitochondrial monoamine oxidase A (MAO-A) activity. MAO-A activation-impaired mitochondrial homeostasis resulted in ROS accumulation and NF-κB activation, thereby enhancing expression of atherogenic and proinflammatory molecules in ECs. It also suppressed mitochondrial function regulator PGC-1α, with involvement of NF-κB and oxidative stress. Inactivation of MAO-A by RDN disrupted the positive-feedback regulation between mitochondrial dysfunction and inflammation, thereby inhibiting EC atheroprone phenotypic alterations and atherosclerosis. CONCLUSIONS: The interplay between MAO-A-induced mitochondrial oxidative stress and inflammation in ECs is a key driver in atherogenesis, and it can be reduced by RDN.

Renal denervation improves vascular endothelial dysfunction by inducing autophagy via AMPK/mTOR signaling activation in a rat model of type 2 diabetes mellitus with insulin resistance.

BACKGROUND: Recent clinical and animal studies have shown that renal denervation (RDN) improves insulin sensitivity and endothelial dysfunction. However, the specific mechanism remains incompletely understood. The purpose of this study is to investigate the effects of RDN on endothelial dysfunction of type 2 diabetes mellitus (T2DM) rat models with insulin resistance and to explore the underlying molecular mechanisms. METHODS: Male Sprague-Dawley rats were fed with or without high-fat diet allocated in different groups, combined with low-dose streptozotocin which induces a rat model to develop T2DM with insulin resistance. RDN was conducted 1 week after the rat models fully developed T2DM. The animals were sub-divided into four groups randomly: control group (CON, n = 6), diabetic group (T2DM, n = 6), diabetic with sham surgery group (Sham, n = 6) and diabetic with RDN group (RDN, n = 6). Rats in all groups were studied at baseline, both preoperatively and 4 weeks after RDN, respectively. Western blot was used to detect the expression of angiotensin-converting enzyme 2 (ACE2) protein and the expression of autophagy-related proteins Beclin1, LC3 and p62 and autophagy signaling pathway AMPK/mTOR proteins and apoptosis-related protein caspase-3 in the aorta endothelial cells. In addition, the effects of ACE2 on autophagy of human umbilical vein insulin resistance endothelial cell culture in vitro were also studied. RESULTS: RDN decreased plasma and renal tissue norepinephrine levels. The Von Willebrand factor level was also decreased, while the plasma level of nitric oxide (NO) was significantly increased after RDN. Compared with the T2DM group and the Sham group, the endothelium-dependent and endothelium-independent diastolic function of the RDN group was improved significantly, the expression of Beclin1, LC3, ACE2 and eNOS proteins was higher, and the level of p62 protein was decreased. Furthermore, we found that RDN can activate the expression of p-AMPK and inhibit the expression of p-mTOR. In cell culture experiment, ACE2 activated p-AMPK and inhibited p-mTOR, thus promoting autophagy. CONCLUSIONS: RDN may not only increase the expression of ACE2 in the vascular endothelium, but also can via ACE2 activate p-AMPK and inhibit p-mTOR, thus promoting autophagy and improving endothelial dysfunction.

Heterogeneous root zone salinity mitigates salt injury to Sorghum bicolor (L.) Moench in a split-root system.

The heterogeneous distribution of soil salinity across the rhizosphere can moderate salt injury and improve sorghum growth. However, the essential molecular mechanisms used by sorghum to adapt to such environmental conditions remain uncharacterized. The present study evaluated physiological parameters such as the photosynthetic rate, antioxidative enzyme activities, leaf Na+ and K+ contents, and osmolyte contents and investigated gene expression patterns via RNA sequencing (RNA-seq) analysis under various conditions of nonuniformly distributed salt. Totals of 5691 and 2047 differentially expressed genes (DEGs) in the leaves and roots, respectively, were identified by RNA-seq under nonuniform (NaCl-free and 200 mmol·L-1 NaCl) and uniform (100 mmol·L-1 and 100 mmol·L-1 NaCl) salinity conditions. The expression of genes related to photosynthesis, Na+ compartmentalization, phytohormone metabolism, antioxidative enzymes, and transcription factors (TFs) was enhanced in leaves under nonuniform salinity stress compared with uniform salinity stress. Similarly, the expression of the majority of aquaporins and essential mineral transporters was upregulated in the NaCl-free root side in the nonuniform salinity treatment, whereas abscisic acid (ABA)-related and salt stress-responsive TF transcripts were more abundant in the high-saline root side in the nonuniform salinity treatment. In contrast, the expression of the DEGs identified in the nonuniform salinity treatment remained virtually unaffected and was even downregulated in the uniform salinity treatment. The transcriptome findings might be supportive of the increased photosynthetic rate, reduced Na+ levels, increased antioxidative capability in the leaves and, consequently, the growth recovery of sorghum under nonuniform salinity stress as well as the inhibited sorghum growth under uniform salinity conditions. The increased expression of salt resistance genes activated in response to the nonuniform salinity distribution implied that the cross-talk between the nonsaline and high-saline sides of the roots exposed to nonuniform salt stress is potentially regulated.

Renal denervation improves cardiac function by attenuating myocardiocyte apoptosis in dogs after myocardial infarction.

BACKGROUND: Myocardial apoptosis is important in the pathogenesis and progression of myocardial infarction-induced heart failure (MI-HF). Renal sympathetic denervation (RDN) has become a promising therapeutic strategy for the treatment of HF. Previous studies have shown that RDN could improve heart function Yao et al. (Exp Ther Med 14:4104-4110, 2017). However, whether and how RDN regulates myocardial apoptosis in MI-HF is unclear. This study sought to evaluate the effects of RDN on cardiac function and apoptosis-related gene expression in MI-HF dogs. METHODS: Eighteen healthy mongrel dogs were randomly divided into control group(n = 6), model group(n = 6) and treatment group(n = 6). MI-HF was established in model group and treatment group by anhydrous alcohol embolization, after heart failure dogs in the treatment group and model group proceeded bilateral renal artery ablation and bilateral renal arteriography, respectively. The cardiac function parameters were evaluated by echocardiographic; the serum NT-BNP level was detected by ELISA; the degree of myocardial fibrosis was observed through masson staining; the expression of MMP-2, MMP-9 in the cardiac were got by immunohistochemistry. TUNEL method was used to observe cardiomyocyte apoptotsis and calculate the apoptosis index (AI). Relative expression of Bcl-2 and Bax, Caspase3 and GRP78 were detected using RT-PCR and Western Blot. Renal artery H&E staining and serum creatinine were conducted to access the efficacy and safety of RDN. RESULTS: Four weeks after RDN, the LVEDD, LVESD and LVEDP decreased, and the LVEF and LVSP increased in the treatment group compared with those in the control group (all P < 0.05). Moreover, NT-BNP, an indicator of cardiac function was decreased. Additionally, MMP-2 and MMP-9 levels in the myocardium decreased significantly in the treatment group. Furthermore, the levels of Bax, and caspase 3 decreased, while the level of Bcl-2 increased. Thus, myocardial apoptosis was attenuated in RDN treated dogs. We also found that the level of GRP78 which is activated in response to endoplasmic reticulum (ER) stress, was decreased. However, serum creatinine levels were not significantly different between the RND-treated dogs and the control dogs. CONCLUSION: Cardiac function was improved by RDN treatment through regulating apoptosis and ER stress in cardiomyocytes in dogs after MI.

[Study on relieving effects of exogenous SNP, Spd on Belamcanda chinensis under salt-alkalline stress].

The study is aimed to provide the theoretical basis for exploiting and utilization of salt-alkaline soil and cultivating Belamcanda chinensis. In this study, we exerted exogenous substances SNP, Spd to relieve the damage of the mixing salt-alkaline stress on B. chinensis seedling which is NaCl, Na2SO4, NaHCO3 and Na2CO3 four kinds of salt molar ratio of 9: 1: 9: 1, salt concentration of 100 mmol x L(-1). The result illustrated that high pH stress is a major factor caused the salt-alkaline stress, the interaction between time and the concentration of each, treatment was observed, what is more, there are synergies between the salt and alkali stress. The content of B. chinensis seedling leaves' membrane peroxidation index (MDA, O2-*) and metabolites (soluble protein, soluble sugars, organic acids) are showing an upward trend in varying degrees under 100 mmol x L(-1) salt-alkaline stress. It is effective to reduce the content of MDA and O2-*. and improve the levels of metabolites, in which the SNP (0.05 mmol x L(-1)) and Spd (0.5 mmol x L(-1)) to alleviate damage effects is the best. Therefore we can hold the conclusion that SNP and Spd can effectively mitigate the damage of B. chinensis seedling on salt-alkaline stress, improve the resistance ability of B. chinensis seedling which can provide the scientific basis for the utilization of salt-alkaline soil, and the cultivation of B. chinensis.