Gαq-protein carboxyl terminus imitation polypeptide GCIP-27 attenuates proliferation of vascular smooth muscle cells and vascular remodeling in spontaneously hypertensive rats

The hMeDIP-Seq identified INPP4A as a novel biomarker for eosinophilic chronic rhinosinusitis with nasal polyps

Background: Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is an endotype of chronic rhinosinusitis with nasal polyps characterized by more severe symptoms, a stronger association with asthma and a greater recurrence risk. It is unknown whether DNA hydroxymethylation could influence ECRSwNP. Methods: Hydroxymethylated DNA immunoprecipitation sequencing was carried out in three distinct groups (control, ECRSwNP and NECRSwNP). Additional qRT-PCR, immunohistochemistry and analysis of the receiver operating characteristic curve were performed. Results: Between ECRSwNP and NECRSwNP, 26 genes exhibited differential DNA hydroxymethylation. Consistent with their hydroxymethylation level, GNAL, INPP4A and IRF4 expression levels were significantly different between ECRSwNP and the other two groups. The receiver operating characteristic curve revealed that INPP4A mRNA has a high predictive accuracy for ECRSwNP. Conclusion: DNA hydroxymethylation regulates the expression of multiple genes in ECRSwNP. INPP4A mRNA was markedly decreased in ECRSwNP polyps and can predict ECRSwNP.

Gαq protein carboxyl terminus imitation polypeptide GCIP-27 improves cardiac function in chronic heart failure rats

Background

Gαq protein carboxyl terminus imitation polypeptide (GCIP)-27 has been shown to alleviate pathological cardiomyocyte hypertrophy induced by various factors. Pathological cardiac hypertrophy increases the morbidity and mortality of cardiovascular diseases while it compensates for poor heart function. This study was designed to investigate the effects of GCIP-27 on heart function in rats with heart failure induced by doxorubicin.

Methods and Results

Forty-eight rats were randomly divided into the following six groups receiving vehicle (control), doxorubicin (Dox), losartan (6 mg/kg, i.g.) and three doses of GCIP-27 (10, 30, 90 μg/kg; i.p., bid), respectively. Heart failure was induced by Dox, which was administered at a 20 mg/kg cumulative dose. After 10 weeks of treatment, we observed that GCIP-27 (30, 90 μg/kg) significantly increased ejection fraction, fraction shortening, stroke volume and sarcoplasmic reticulum Ca²⁺ ATPase activity of Dox-treated hearts. Additionally, GCIP-27 decreased myocardial injury, heart weight index and left ventricular weight index, fibrosis and serum cardiac troponin-I concentration in Dox-treated mice. Immunohistochemistry, western blotting and real-time PCR experiments indicated that GCIP-27 (10–90 μg/kg) could markedly upregulate the protein expression of myocardial α-myosin heavy chain (MHC), Bcl-2, protein kinase C (PKC) ε and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 as well as the mRNA expression of α-MHC, but downregulated the expression of β-MHC, Bax and PKC βII, and the mRNA expression levels of β-MHC in Dox-treated mice. It was also found that GCIP-27 (30, 90 μg/L) decreased cell size and protein content of cardiomyocytes significantly in vitro by comparison of Dox group.

Conclusions

GCIP-27 could effectively ameliorate heart failure development induced by Dox. PKC–ERK1/2 signaling might represent the underlying mechanism of the beneficial effects of GCIP-27.

Lentil-based diets attenuate hypertension and large-artery remodelling in spontaneously hypertensive rats

Hypertension is a major risk factor for CVD, the leading cause of mortality worldwide. The prevalence of hypertension is expected to continue increasing, and current pharmacological treatments cannot alleviate all the associated problems. Pulse crops have been touted as a general health food and are now being studied for their possible effects on several disease states including hypertension, obesity and diabetes. In the present study, 15-week-old spontaneously hypertensive rats (SHR) were fed diets containing 30% w/w beans, peas, lentils, chickpeas, or mixed pulses or a pulse-free control diet for 4 weeks. Normotensive Wistar-Kyoto (WKY) rats were placed on a control diet. Pulse wave velocity (PWV) was measured weekly, while blood pressure (BP) was measured at baseline and week 4. Fasting serum obtained in week 4 of the study was analysed for circulating lipids. A histological analysis was carried out on aortic sections to determine vascular geometry. Of all the pulse varieties studied, lentils were found to be able to attenuate the rise in BP in the SHR model (P< 0·05). Lentils were able to decrease the media:lumen ratio and media width of the aorta. The total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol levels of rats fed the pulse-based diets were found to be lower when compared with those of the WKY rat and SHR controls (P< 0·05). Although all pulses reduced circulating TC and LDL-C levels in the SHR, only lentils significantly reduced the rise in BP and large-artery remodelling in the SHR, but had no effect on PWV. These results indicate that the effects of lentils on arterial remodelling and BP in the SHR are independent of circulating LDL-C levels.

Transmembrane transport of the Gαq protein carboxyl terminus imitation polypeptide GCIP-27

The Gαq protein carboxyl terminus imitation polypeptide (GCIP)-27 has been shown to affect cardiac hypertrophy and vascular remodeling in various models both in vitro and in vivo. Transport across the plasma membrane is a critical step in regulating the action of this peptide drug. This study was designed to explore the mechanisms underlying the transmembrane transport of GCIP-27. The peptide drug was labeled with fluorescein isothiocyanate (FITC), and measured in a time- and concentration-dependent manner using laser confocal microscopy. Various transport inhibitors, including energy and endocytosis inhibitors, were used to identify the factors that regulate its transmembrane transport. GCIP-27 transport was examined in cardiomyocytes, cardiac fibroblasts, vascular endothelial cells, vascular smooth muscle cells (VSMCs) and hepatocytes. Atomic force microscopy and scanning electron microscopy were used to determine the ultrastructure of the cardiomyocyte membranes. The results showed that GCIP-27 was transported through the plasmalemma in a time- and concentration-dependent manner. The rate of uptake and the level of GCIP-27 in the cells decreased significantly after treatment with energy inhibitors, methyl-ß-cyclodextrin chlorpromazine or heparin. GCIP-27 levels in VSMCs and cardiomyocytes were significantly greater than the levels observed in hepatocytes, cardiac fibroblasts and vascular endothelial cells. Treatment with GCIP-27 led to a marked increase in the surface roughness of the cellular membrane. In conclusion, the transmembrane transport of GCIP-27 is mediated by endocytosis, which requires energy, and GCIP-27 preferentially enters myocardial cells and VSMCs.

Increased susceptibility to metabolic syndrome in adult offspring of angiotensin type 1 receptor autoantibody-positive rats

AIMS

Abnormal fetal and early postnatal growth is closely associated with adult-onset metabolic syndrome (MetS). However, the underlying etiological factors remain complex. The presence of the autoantibody against the angiotensin II type 1 receptor (AT1-Ab), a known risk factor for pre-eclampsia, may create a suboptimal intrauterine fetal environment. The current study investigated whether middle-aged offspring of AT1-Ab-positive mothers were prone to metabolic disorder development.

RESULTS

The AT1-Abs was detected in placental trophoblastic cells, capillary endothelium, and milk of pregnant rats actively immunized with the second extracellular loop of the AT1 receptor. AT1-Abs in newborn rats induced vasoconstriction, increased intracellular-free Ca(2+) in vitro, and was undetectable 7 weeks later. Immunized group offspring exhibited increased weight variability and insulin resistance at 40 weeks of age under a normal diet, evidenced by elevated fasting serum insulin and homeostasis model assessment score compared with the vehicle control. To further observe metabolic alterations, the offspring were given a high-sugar diet (containing 20% sucrose) 40-48 weeks postnatally. The fasting plasma glucose in immunized group offspring was markedly increased. Concomitantly, these offspring manifested increased visceral adipose tissue, increased fatty liver, increased triglycerides, decreased high-density lipoprotein cholesterol, and decreased adiponectin levels, indicative of MetS.

INNOVATION

AT1-Abs could be transferred from mother to offspring via the placenta and milk. Moreover, offspring of an AT1-Ab-positive mother were more vulnerable to MetS development in middle age.

CONCLUSION

AT1-Ab-positivity of mothers during pregnancy is a previously unrecognized "silent" risk factor for MetS development in their offspring.