Preliminary Study On Carboxylesterase-1 As A New Biomarker Of Early Liver Damage

Mammalian carboxylesterase(CEs)is a member of the important serine hydrolase family.CEs can be divided into 5 subtypes,but the major subtypes are carboxylesterase 1(CE1)and carboxylesterase(CE2),mainly in the endoplasmic reticulum of tissue.Carboxylesterase 1(Human Carboxylesterases 1,hCE1),as a class of metabolic enzymes,is widely found in human liver,kidney and skin tissues,but is highly specific and highly distributed in the liver.hCE1 is responsible for the hydrolysis of various endogenous substances including cholesterol esters,triglycerides,etc.,and plays a key role in maintaining the balance of lipid metabolism in the body.In addition,it catalyzes the hydrolysis of various exogenous substances,such as environmental toxins and some clinical drugs.It also plays an important role in the defense system of an organism.Due to the specific distribution of hCE1 in the liver during injury,the liver cells get rupture and hCE1 release into the blood,so the enzyme can be detected in the blood.The liver is one of the most important vital organs of the human body.It is the main organ in carbohydrate,protein,lipid,vitamin metabolism,along with secretion,excretion,detoxification and biotransformation etc.It also plays an important role as an anatomical and physiological function which are liver-specific factors.This was based on a variety of endogenous/exogenous such as viruses,bacteria,inflammation,drugs and environmental toxins which results the liver function damaging to varying degrees,eventually leading to disease.The precise prediction and diagnosis of liver injury are the focus of clinical medicine,which has been widely concerned by researchers.Because of its complex mechanism of injury,there are many influencing factors which often involve the engagement of many metabolic reactions causing immune responses.So,its inspection method still has many problems.Better serum markers needed to be rapid,simple,sensitive,accurate and able to respond to problems ahead of time.At present,the clinical liver injury is mainly relying on the liver biochemical examination,including some liver enzyme examination,liver synthesis function and liver fibrosis serum indicators,can reflect the liver function more comprehensive.The indexes of liver fibrosis were specific,but not sensitive.Taking into account these indicators cannot be effectively classified and reflect the early liver function combined with other related indicators need to be considered.With the rapid development of proteomics,metabolomics,clinical laboratory related science and technology in recent years will enhance the finding of new markers.It will eventually make up some shortcomings of the traditional indicators.However,It still remains in the early stage of research.Therefore,it is important to find and affirm the new serum markers for early diagnosis and treatment of a liver injury.In this work,the detection of hCE1 in plasma by using the specific fluorescent probe of carboxylesterase 1 was studied.The probe was held as the substrate of hCE1,which was metabolized by hCE1 to produce the corresponding product.The activity of carboxylesterase was determined by HPLC Fluorescence Analysis.Detection of hCE1 and its activity was found in serum of injured liver with different causes.In order to explore the relationship between the enzyme and different liver diseases,obtained results were compared with the current clinical criteria for various liver injury.The new findings led us to explore the feasibility and significance as a new marker.