* Corresponding author: Awaz A. Saadi, awaz.arshad@uod.ac DOI: 10.3269/1970-5492.2024.19.13 All rights reserved. ISSN: 2279-7165 - Available on-line at www.embj.org EUROMEDITERRANEAN BIOMEDICAL JOURNAL 2024,19 (13) 63 - 66 (FORMERLY: CAPSULA EBURNEA) Original article SERUM HSP 90 LEVELS OF CHRONIC HEPATITIS B PATIENTS ARE SUBSTANTIALLY CORRELATED WITH HBV DNA VIRAL LOAD Awaz A. Saadi The University Of Duhok, Kurdistan Region, Iraq A R T I C L E I N F O Article history: Received 20 Apr 2024 Accepted 30 Sep 2024 Published 30 Dec 2024 Keywords: HSP90, HBV DNA, HBs Ag. A B S T R A C T The highly conserved molecules that make up the mammalian HSP90 family of proteins are engaged in a wide range of cellular functions. HSP90 and its co-chaperones regulate vital physiological processes as apoptosis, hormone signaling, and cell cycle regulation. The aim of this research are to examine the critical function that HSP90 plays in chronic HBV patients and to determine the association between this protein type and other immunological and biochemical markers as well as the HBV DNA factor. 88 chronic HBV patients were included in the trial, which ran from June to December 2015. The levels of ALT, AST, AFP, HBsAg, HBeAg, and anti-HBsAb were measured. The results showed a significant correlation between HSP90 [mean of 4.909±10.4839] with the titer of HBV DNA in the serum [190943784.21±180568331.64] in the chronic HBV patients at (P=0.002) involved in the study [P=or <0.01]. the relationship between HSP90 and other serological and biochemical parameters are shown no significant correlation. © EuroMediterranean Biomedical Journal 2024 1. Introduction Heat Shock Proteins HSPs are a group of highly conserved molecules that are involved in a wide range of biological functions in the mammalian. They play crucial functions in maintaining cellular homeostasis, as evidenced by their distribution in different cellular compartments. It has been discovered that overexpressing HSPs helps cells survive and guards against protein deterioration or aggregation. In addition to heat shock, a number of factors, including as environmental and chemical factors, physiological causes unrelated to stress, and illness states, promote the expression of HSPs [1]. Furthermore, studies revealed that multiple HSP families and related antigens can induce more potent polyclonal immunity than a single HSP, as has been demonstrated in the realm of cancer and some of infectious diseases [2,3]. Members of the Heat Shock Protein 90 (HSP90) family are ATP- dependent molecular chaperones that contains a homodimer biologically functional unit divided of three distinct regions linked by flexible bind. Each promoter contains a highly-conserved N-terminal domain (NTD) responsible for nucleotide binding, a middle domain (MD) important for client recognition and ATP hydrolysis and a C-terminal domain (CTD), which is the primary site responsible for dimerization [4]. HSP90 chaperones control the stability and performance of client proteins implicated in cancer cell proliferation, survival, and cellular stress adaptation. Also, cell cycle regulation, hormone signaling, and apoptosis are important physiological processes that are controlled by HSP90 and its co-chaperones. In addition to being a crucial part of various signal transduction pathways, the HSP90 is now recognized as a crucial host factor for hepatitis B virus replication. Furthermore, HSPs as general and specially HSP90 and their cofactors have been shown to block both necrotic and apoptotic pathways through comparable methods. In order to cure neoplasms and other disorders. The experimental validation of these proteins may result in the expansion of existing protein interaction networks and the discovery of new processes. Diagnostic proteomic techniques may be used to therapeutically screen people who are at high risk of developing cancer as example of devastating disease and other serious chronic diseases because the creation of these big stable chaperone species appears to be cancer-specific, targeting such species is most likely to be advantageous [5]. The steroids nuclear receptors pathway is another route by which HSP90 may be implicated in cell survival. The interactions between HSP70, HSP40, and HSP90 stabilize the complex in the absence of stimulation to stop it from activating. These receptors' maturation, intracellular trafficking, and regulation are all affected by HSP90. When a particular ligand connects with its receptor, an ATP-dependent conformational change happens, causing transcription factors to go to the nucleus and activate target genes [6].