Cathepsin S is a biomarker of death from senile diseases
Swedish researchers from Uppsala University, working under the leadership of Johan Arnlov, found that a significant increase in the concentration of cathepsin S – a compound involved in the regulation of inflammatory processes – in the blood plasma of elderly people indicates a high probability of death from cancer or cardiovascular diseases over the next 12 years. Scientists came to such conclusions after analyzing data on almost 2,000 people.
As part of their work, the scientists examined two groups of people with an average age of 70 years. After twelve years, almost a quarter of the observed died. At the same time, the relationship between high levels of cathepsin S and an increased risk of death persisted even after correcting the results taking into account factors such as age, body weight, blood pressure, medications taken and previous illnesses.
Analysis of data on patients in one group showed that the highest levels of cathepsin S in the blood increase the risk of death within 12 years by two times compared with the lowest levels of this compound. Observation of patients of the other group made it possible to identify specific diseases from which people with high levels of cathepsin S die, they turned out to be the two main causes of death of elderly people: cardiovascular diseases and cancer.
The data obtained are consistent with the results of an earlier animal study, according to which cathepsin S is involved in the formation of tumors and atherosclerotic plaques on the walls of arteries that cause diseases of the cardiovascular system.
The possible role of cathepsin S in the progression of atherosclerosis and malignant diseases (figure from the article in JAMA)
Cathepsin S is a lysosomal cysteine protease that can also be released into the cytoplasm, expressed on the cell surface and secreted into the intercellular space.
The assumption that the proteolytic activity of cathepsin S contributes to the development of atherosclerosis and malignant neoplasms is based mainly on the results of immunohistochemical experiments.
Determination of the localization and amount of cathepsin S in various tissues on histological sections of human tissues and mice without cathepsin S revealed its activity in atherosclerotic plaques and tumors.
Cathepsin S is also involved in the presentation of antigens of the main histocompatibility complex of class II and the development of inflammatory reactions. Both of these processes are involved in the development of diseases of the cardiovascular system and cancer.
Abbreviations:
IEL (internal elastic lamina) is an internal elastic plate lining the arteries,
ECM (extracellular matrix) is an intercellular matrix.
Moreover, the results of several small studies involving humans indicate that obesity and diabetes are associated with elevated levels of cathepsin S in the blood. Apparently, this compound is involved in the development of many diseases accompanied by chronic inflammation and pain syndrome.
To date, it is not yet clear whether cathepsin S can be used as a prognostic factor. Scientists will have to determine whether this compound is associated with specific diseases or is a biomarker common to physiological aging of the body and poor health. However, the results obtained may renew interest in cathepsin S as a potential therapeutic target. Currently, a number of drugs that suppress the activity of this molecule are undergoing clinical trials as agents for the treatment of autoimmune diseases and chronic pain syndrome.
Article by Elisabeth Jobs et al. Association Between Serum Cathepsin's and Mortality in Older Adults is published in open access on the JAMA website.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Technology Review:
Blood Biomarker Is Linked with Death
30.08.2011