The role of clusterin/ApoJ on the ocular surface in experimental models of obesity: implications of different physical training protocols

Author(s)

Thais Dantis Pereira de Campos

• Document type: Master's Dissertation
• Press: Limeira, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Aplicadas
• Defense date: 2020-08-20

Examining board members

Leandro Pereira de Moura; Igor Luchini Baptista; Carlos Kiyoshi Katashima; Bruno Rodrigues

• Advisor: Leandro Pereira de Moura

Abstract

Obesity can be considered a clinical and epidemiological phenomenon today. In this sense, factors such as eating habits and a sedentary lifestyle play an important role in the pathogenesis of this disease. Obesity is a multifactorial, chronic and non-communicable disease, defined by the accumulation of adipose tissue that is commonly associated with systemic inflammation. This situation is linked to health damage and its incidence is increasing worldwide. This disorder has been correlated as being responsible for the appearance of several eye diseases and consequently for damage to visual acuity. More specifically, the cardiometabolic risk, due to the progression of the proinflammatory profile, seems to be associated with dysfunctions of the lacrimal gland, implying the development and worsening of Kerato-Conjunctivitis Sicca or popularly known as dry eye disease. In more severe and extreme cases, the condition of obesity and inflammation can trigger severe damage to vision. In this scenario, in addition to its numerous metabolic functions, clusterin has been described as protective of the ocular surface by a sealing mechanism, which helps in cell survival. On the other hand, it is known that physical exercise can act as an important non-pharmacological tool in the fight against inflammation and obesity. However, no study has yet investigated whether regular physical exercise and different protocols can modulate the clusterin signaling pathway in the retina and thus be able to promote an improvement in visual acuity. Therefore, the present study aims to elucidate the role of different chronic physical exercise protocols (combined and strength) in the levels of clusterin and pro and anti-inflammatory proteins in the retina of obese mice. Through bioinformatics, we observed an important expression of clusterin and LRP2 in human and mouse tissues, in addition to the interaction with genes very expressed in the retina, such as rhodopsin. In this sense, after short combined training, we found that exercise was able to improve the insulin sensitivity of the exercised group when purchased from the sedentary obese, as well as the inflammatory profile. Short-term strength training, on the other hand, was able to promote an increase in the gene expression of anti-inflammatory proteins and an increase in the protein content of the CLU precursor, as well as a tendency to increase the levels of CLU and LRP2. Therefore, these results show that a short period of physical exercise, even without interference from body weight, is able to initiate a reduction in the inflammation of the retina of obese animals and, thus, promote protection against eye diseases. (AU)

• FAPESP's process: 18/06833-8 - Could physical exercise improve visual acuity? Effects of different physical training protocols on tear composition and clusterin/ApoJ metabolism in the retina of obese rodent
• Grantee: Thaís Dantis Pereira de Campos
• Support Opportunities: Scholarships in Brazil - Master