Pinealectomy Reduces Gene Expression of Caspase 9 in Subcutaneous Adipose Tissue of Rats

Abstract

Previous studies have shown that pinealectomy induces insulin resistance in rats. The present study aimed to verify whether pinealectomy modulates the expression of apoptosis‐related genes in rat subcutaneous adipose tissue (TA‐Sc). For this purpose, samples from the bank of frozen tissue of animals (Ethics Committee/Institute of Biomedical Sciences (ICB) Protocol No. 896/2017), belonging to the Laboratory of Adipose Tissue Physiology, University of Sao Paulo (USP), were used. The material came from Wistar rats (male and adults), whose were kept at the Experimentation Hall of the Department of Physiology and Biophysics of the ICB/USP and handled according to a certificate approved by the Ethics Committee on the Use of Animals (CEUA)/(03/10/2011, protocol no. 129) and standards established by the National Council for Control of Animal (CONCEA). The rats were housed in polypropylene boxes under controlled environmental conditions (25 ± 2 ºC) and light (12 h light/12 h dark), with water and standard ration for Nuvilab® rodents (Nuvital S/A, Colombo, PR) ad libitum. The animals, when completed 10 weeks old, were anesthetized and submitted to pinealectomy (P) by the method of Hoffman and Reiter (1965) or to the fictitious operation (C) and, following their recovery, they were kept in individual boxes. After four weeks of the surgery (14 weeks old) the animals P and C were killed by decapitation and inguinal TA‐Sc dissected. For the evaluation of gene expression related to apoptosis, samples of the Sc fat pad were submitted to the Total RNA Extraction stages; Synthesis of cDNA by Reverse Transcription and Polymerase Chain Reaction from cDNA (Real Time PCR). PCR reactions were performed by the StepOnePlus® Real Time PCR System (Applied Biosystems). The evaluated genes were: Caspases (3, 8, 9), Bax, Fas and BCL‐2. The data were analyzed according to the requirements of homoscedasticity and normality by means of the Shapiro‐Wilk test and later the Student's t‐test, unpaired and parametric. The 95% confidence interval and p value <0.05 were considered significant. The statistical program used was Graph Pad Prism version 6.0. The results showed that pinealectomy did not alter the expression of the anti and pro‐apoptotic genes evaluated (p> 0.05), with the exception of Caspase 9, whose gene expression was significantly reduced in group P in relation to C (Figure 1). In conclusion, pinealectomy is capable of selectively interfering with the gene expression of the apoptotic pathway, specifically in the caspase activator 9.Support or Funding InformationConselho Nacional de Desenvolvimento Científico e Tecnológico‐CNPqThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.