Liver paraoxonase 3 expression and the effect of liraglutide treatment in a rat model of diabetes

BACKGROUND

This study investigated liver expression of paraoxonase 3 (PON3), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and nuclear factor (NF)-κB in a rat model of type-2 diabetes mellitus (T2DM), and assessed the effect of liraglutide treatment.

OBJECTIVES

To investigate liver PON3 expression in rats withT2DM assess its role in disease pathogenesis, and determine the effect of liraglutide on its expression.

MATERIAL AND METHODS

Type 2 diabetes mellitus was induced in 3 groups of rats: positive control group (PC; no treatment), and low-dose (LL; 100 μg/kg) and high-dose (HL; 200 μg/kg) liraglutide groups. Healthy rats served as a normal control (NC) group. Protein and mRNA expression were measured with western blot and reverse-transcriptase polymerase chain reaction (RT-PCR), respectively.

RESULTS

After liraglutide treatment, fasting plasma glucose (FPG), homeostasis model assessment-insulin resistance (HOMA-IR), fasting insulin (FINS), malondialdehyde (MDA), and interleukin 6 (IL-6) levels were lower in HL rats compared with LL ones (p < 0.05). Compared to NC rats, FPG, FINS, HOMA-IR, low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and IL-6 levels were the lowest in HL rats, followed by LL and PC ones (p < 0.05). Body weight (BW) was lower in LL and HL groups than in NC and PC (p < 0.05). The liver expression of PON3, PI3K and Akt were the highest in HL rats, followed by LL and PC (p < 0.05). The NF-κB expression was the lowest in HL rats, followed by LL and PC (p < 0.05). The PON3 expression was decreased in the diabetic rat liver.

CONCLUSIONS

Liraglutide can increase PI3K, Akt and PON3 expression, and decrease NF-κB expression. The effect of liraglutide on improving insulin resistance and abnormal glucolipid metabolism in T2DM rats may be associated with increased liver PON3 expression.

Serum paraoxonase 1 and 3 activities in benign and malignant diseases of the prostate and changes in levels following robotic-assisted laparoscopic radical prostatectomy

Background/aim

This study aimed to examine serum paraoxonase 1 and 3 (PON1 and PON3) activities in benign and malignant diseases of the prostate, to determine lipid profile and malondialdehyde (MDA) levels, and to investigate changes in levels following robotic-assisted laparoscopic radical prostatectomy (RALRP).

Materials and methods

A total of 137 patients, including a control group, were enrolled in the study and assigned into four groups. Group 1 (n = 33) consisted of patients previously undergoing RALRP with no recurrence, group 2 (n = 36) consisted of patients diagnosed with prostate cancer (PCa) and undergoing RALRP, and group 3 (n = 34) consisted of patients diagnosed with benign prostatic hyperplasia. The control group (n = 34) consisted of healthy individuals. Serum low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, cholesterol, prostate-specific antigen (PSA), PON1, PON3, and MDA values were measured. In addition, group 2 MDA, PON1, PON3, and PON1/HDL levels were investigated preoperatively and at the first month postoperatively.

Results

Significant changes were found in PON1, PON3, and MDA levels. PON1 and PON3 levels decreased significantly in patients with PCa, while MDA levels increased. PON1 and PON3 increased postoperatively in the PCa group, while MDA decreased. BPH group PON1, PON3, and MDA levels were higher than those of the control group.

Conclusion

An increase in free oxygen radicals in the body or a decrease in endogenous antioxidant enzyme levels can result in malignant and benign diseases of the prostate. Surgical excision of malignant tissue in PCa causes a decrease in oxidative stress.

The association between lecithin-cholesterol acyltransferase activity and fatty liver index

Background

Non-alcoholic fatty liver disease is a frequent ailment with known complications, including those within the cardiovascular system. Associations between several indicators of high-density lipoprotein metabolism and function with clinical and laboratory parameters for the assessment of fatty liver index, a surrogate marker of non-alcoholic fatty liver disease, were evaluated.

Methods

The study comprised 130 patients classified according to fatty liver index values: fatty liver index < 30, fatty liver index 30–59 (the intermediate group) and fatty liver index ⩾ 60. Lecithin–cholesterol acyltransferase and cholesteryl ester transfer protein activities were determined. Paraoxonase 1 concentration and its activity, paraoxonase 3 concentration and high-density lipoprotein subclass distribution were assessed.

Results

Increased lecithin–cholesterol acyltransferase activity correlated with increased fatty liver index ( P < 0.001). Paraoxonase 3 concentration was lower in the fatty liver index ⩾ 60 group compared with the fatty liver index < 30 group ( P < 0.05). Cholesteryl ester transfer protein activity, paraoxonase 1 concentration and its activity did not significantly differ across the fatty liver index groups. The relative proportion of small-sized high-density lipoprotein 3 subclass was higher in the fatty liver index ⩾ 60 group compared with the other two fatty liver index groups ( P < 0.01). Lecithin–cholesterol acyltransferase activity positively associated with the fatty liver index ⩾ 60 group and remained significant after adjustment for other potential confounders. Only the triglyceride concentration remained significantly associated with lecithin–cholesterol acyltransferase activity when the parameters that constitute the fatty liver index equation were examined.

Conclusions

Higher lecithin–cholesterol acyltransferase activity is associated with elevated fatty liver index values. Significant independent association between triglycerides and lecithin–cholesterol acyltransferase activity might indicate a role of hypertriglyceridaemia in alterations of lecithin–cholesterol acyltransferase activity in individuals with elevated fatty liver index.

Paraoxonase 3 inhibits cell proliferation and serves as a prognostic predictor in hepatocellular carcinoma

Paraoxonase 3 (PON3) exerts prominent anti-inflammation and anti-oxidation properties mainly at the cellular level, and is primarily expressed in the liver. However, its role in HCC remains unexplored. Here, we investigated the expression pattern, clinical significance, and function of PON3 in HCC. PON3 mRNA and protein levels were respectively determined in two large cohorts using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) of tissue microarray. We found that PON3 was downregulated in most HCCs. Kaplan-Meier and log-rank test showed that PON3 downregulation predicted shorter recurrence-free survival (RFS) and overall survival (OS) time in all HCC patients, especially early-stage HCC patients. Cox regression analysis revealed that the PON3 downregulation was an independent risk factor for RFS and OS. Gain- and loss-of-function experiments revealed that PON3 suppressed cell proliferation in vivo and in vitro, which was attributed to its cell-cycle arrest effect. In addition, microarray analysis showed that some pro-proliferative genes were elevated when PON3 was knockdown, and these genes possibly involved in the underlying mechanisms. In conclusion, our studies reveal the cell proliferation inhibitory function of PON3 and offer a potential prognostic predictor and therapeutic target for HCC.

Array CGH analysis of a cohort of Russian patients with intellectual disability

The use of array comparative genomic hybridization (array CGH) as a diagnostic tool in molecular genetics has facilitated the identification of many new microdeletion/microduplication syndromes (MMSs). Furthermore, this method has allowed for the identification of copy number variations (CNVs) whose pathogenic role has yet to be uncovered. Here, we report on our application of array CGH for the identification of pathogenic CNVs in 79 Russian children with intellectual disability (ID). Twenty-six pathogenic or likely pathogenic changes in copy number were detected in 22 patients (28%): 8 CNVs corresponded to known MMSs, and 17 were not associated with previously described syndromes. In this report, we describe our findings and comment on genes potentially associated with ID that are located within the CNV regions.