Angiotensin-converting enzyme and Angiotensin-converting enzyme 2 are involved in sinoaortic denervation-induced cardiovascular hypertrophy in rats

Barbaloin Attenuates Mucosal Damage in Experimental Models of Rat Colitis by Regulating Inflammation and the AMPK Signaling Pathway

Background

Barbaloin is one of the main medicinal ingredients of aloe vera, which displays various anti-inflammatory and anti-apoptosis properties in several inflammatory and fibrotic diseases. Our study evaluated its efficacy against dextran sulfate sodium (DSS)-induced colitis in rats.

Material/Methods

Ulcerative colitis (UC) rat models were established in vivo, and after barbaloin treatment, body weight and inflammation index were measured. Additionally, the signaling mechanism by which barbaloin protects against UC was investigated using LPS-infected Caco-2 cells.

Results

Barbaloin could significantly reverse UC-induced weight loss and colon injury. Further, it could effectively increase the mRNA expression of IL-4 and IL-10 in colon tissues, while decreasing the expression of IFN-γ, IL-6, IL-1β, and TNF-α. Furthermore, it significantly enhanced UC-inhibited atresia band 1 (ZO-1), occludin, and E-cadherin, and was also found to activate the AMPK signaling pathway. Additionally, si-RAN-induced knockdown, and overexpression assay showed that barbaloin could inhibit the UC-enhanced MLCK signaling pathway by activating the AMPK signaling pathway.

Conclusions

Barbaloin can effectively inhibit inflammation and reverse epithelial barrier function to protect against UC, possibly via activation of the AMPK signaling pathway.

Effects of losartan on vasomotor function and canonical transient receptor potential channels in the aortas of sinoaortic denervation rats

Increased short-term blood pressure variability (BPV) is strongly correlated with target organ damage. However, the molecular mechanisms underlying abnormal BPV-induced organ damage and effective therapeutic targets are poorly understood. The purpose of this study was to investigate the effects of losartan on vasomotor function and canonical transient receptor potential (TRPC) channels in the aortas of rats with arterial pressure lability induced by sinoaortic denervation (SAD). SAD was performed in male Sprague-Dawley rats at the age of 10 weeks. The experiment included sham-operated (Sham), SAD, and losartan-treated SAD (SAD+Los) groups. After 8 weeks of treatment, hemodynamic parameters were measured via catheterization, thoracic aortic vasomotor functions were evaluated using a physiological vascular ring tension recording system, and TRPC1 and 6 mRNA and protein expression levels in the endothelial cells (ECs) and smooth muscle cells (SMCs) of the thoracic aorta were determined via reverse transcription polymerase chain reaction (RT-PCR) and Western-blotting, respectively. Compared with Sham rats, SAD rats exhibited significantly increased BPV, enhanced norepinephrine-induced aortic contraction, and attenuated acetylcholine-induced aortic relaxation. Both the mRNA and the protein expression levels of TRPC1 and 6 were significantly downregulated in the ECs and upregulated in the SMCs of the thoracic aortas of SAD rats. Losartan treatment prevented these SAD-induced changes. In conclusion, losartan efficiently prevented vasomotor function impairment in SAD rats by reducing BPV and regulating TRPC1 and 6 expression levels.

Berberine alleviates dextran sodium sulfate-induced colitis by improving intestinal barrier function and reducing inflammation and oxidative stress

Berberine has demonstrated efficacy in alleviating experimental colitis in vivo and in vitro. However, the anti-colitis mechanisms of berberine that enable it to promote intestinal barrier function in vivo remain unclear. The present study aimed to evaluate the effect of berberine on intestinal epithelial barrier function, expression of tight junction proteins and the levels of inflammatory and oxidative stress factors in the intestinal mucosa of dextran sulfate sodium (DSS)-induced colitis mice. Berberine (100 mg/kg) was administered for five days to mice with established colitis, induced by administration of DSS (3% w/v) for six days. Intestinal barrier function and the presence of proinflammatory factors, oxidative stress and active signaling pathways in the colon were determined principally by western blotting and reverse transcription-quantitative polymerase chain reaction. It was observed that berberine reduced weight loss, shortening of the colon and colon damage in DSS-colitis mice. In addition, berberine significantly inhibited the increase of fluorescein isothiocyanate-dextran in serum and the decrease of zonula occluden-1 (also known as tight junction protein-1), occludin and epithelial cadherin expression in colonic tissue, relative to a DSS-treated control group. Berberine also significantly inhibited the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α mRNA and phosphorylation of signal transducer and activator of transcription 3. Furthermore, berberine reduced the levels of myeloperoxidase and increased the levels of superoxide dismutase and catalase in colon and serum samples relative to the control group. The expression of cluster of differentiation 68 in the colon of colitis mice was also reduced by berberine. Collectively, these data suggest that berberine alleviates colitis principally by improving intestinal barrier function and promoting anti-inflammatory and antioxidative stress responses. In turn these effects inhibit macrophage infiltration into the colon and thus may be central to the anti-colitis activity of berberine.

Characteristic enhancement of blood pressure V-shaped waves in sinoaortic-denervated rats in a conscious and quiet state

A hemodynamic feature of chronic sinoaortic-denervated (SAD) rats is the increase in blood pressure variability (BPV) without significant changes in the average level of blood pressure (BP). The current study was designed to investigate the changes in BP V-shaped waves (V waves) in SAD rats. Sprague-Dawley (SD) rats were divided into 2 groups: SAD rats and sham-operated rats (n=13). Hemodynamics measurements were obtained in conscious, freely moving rats, four weeks after sinoaortic denervation or sham operation. V wave indices were evaluated in rats in both conscious and quiet states. Additionally, normal and high BPV was simulated by the production of V waves with different amplitudes. The results showed that the V wave amplitude was dramatically increased, with a significantly prolonged duration and reduced frequency in SAD rats. V wave BPV in SAD rats was significantly increased, though BP remained unchanged. The twenty-four hour BPV in all rats was positively correlated with amplitude, duration time and V wave BPV and negatively correlated with frequency. The systolic BP spectral powers in the low frequency range (0.38-0.45 Hz) were significantly reduced in the V waves of SAD rats. Moreover, there was a remarkable increase in mean BPV and a normal mean BP after simulating high BPV in SAD rats. These results suggest that enhancement of V waves might be a waveform character of BP in SAD rats in both the conscious and quiet states. These types of V waves appear to be related to a depression of sympathetic regulation of BP induced by sinoaortic denervation.

Propionate Ameliorates Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Reducing Inflammation and Oxidative Stress

Propionate is a short chain fatty acid that is abundant as butyrate in the gut and blood. However, propionate has not been studied as extensively as butyrate in the treatment of colitis. The present study was to investigate the effects of sodium propionate on intestinal barrier function, inflammation and oxidative stress in dextran sulfate sodium (DSS)-induced colitis mice. Animals in DSS group received drinking water from 1 to 6 days and DSS [3% (w/v) dissolved in double distilled water] instead of drinking water from 7 to 14 days. Animals in DSS+propionate (DSS+Prop) group were given 1% sodium propionate for 14 consecutive days and supplemented with 3% DSS solution on day 7–14. Intestinal barrier function, proinflammatory factors, oxidative stress, and signal transducer and activator of transcription 3 (STAT3) signaling pathway in the colon were determined. It was found that sodium propionate ameliorated body weight loss, colon-length shortening and colonic damage in colitis mice. Sodium propionate significantly inhibited the increase of FITC-dextran in serum and the decrease of zonula occludens-1 (ZO-1), occludin, and E-cadherin expression in the colonic tissue. It also inhibited the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) mRNA and phosphorylation of STAT3 in colitis mice markedly, reduced the myeloperoxidase (MPO) level, and increased the superoxide dismutase and catalase level in colon and serum compared with DSS group. Sodium propionate inhibited macrophages with CD68 marker infiltration into the colonic mucosa of colitis mice. These results suggest that oral administration of sodium propionate could ameliorate DSS-induced colitis mainly by improving intestinal barrier function and reducing inflammation and oxidative stress via the STAT3 signaling pathway.

NADPH oxidase contributes to the left ventricular dysfunction induced by sinoaortic denervation in rats

The aim of this work was to investigate the role nicotinamide adenine dinucleotide phosphate (NADPH) oxidase on left ventricular dysfunction of rats submitted to sinoaortic denervation (SAD). Experiment 1: 8 weeks after SAD of rats, NADPH oxidase in left ventricles was assayed by Western blotting analysis. Experiment 2: Rats were subjected to SAD and received treatment with apocynin (an NADPH oxidase inhibitor, 30 mg/kg/day, intragastric administration) for 8 weeks; 8 weeks after SAD, Nox2 and Nox4 expressions and Rac1 activity of left ventricles were higher in SAD rats than those in sham-operated rats. Although treatment of SAD rats with apocynin did not affect blood pressure, blood pressure variability (BPV), and baroreflex function, it significantly attenuated left ventricular hypertrophy marked by reduced expression of atrial natriuretic factor and β-myosin heavy chain. Treatment of SAD rats with apocynin abated oxidative stress marked by reduced malondialdehyde formation and suppressed nuclear factor-kappa B (NFκB) activation; inflammation marked by reduced monocyte chemoattractant protein-1 expression and myeloperoxidase activity; attenuated endoplasmic reticulum stress marked by reduced expression of CCAAT-enhancer-binding protein homologous protein, chaperone-glucose-regulated protein 78, and X-box protein 1; and alleviated cardiac fibrosis marked by reduced mRNA levels of collagens I and III and transforming growth factor beta. In conclusion, exaggerated BPV induces chronic myocardial oxidative stress and thereby aggravates cardiac remodeling in rats. These data suggest a potential role of NADPH oxidases in the pathogenesis of cardiac dysfunction induced by exaggerated BPV.