en Clinical Biochemistry Clinical Biochemistry Original Article Original Article <span style="font-size:12px;"><span style="font-family:Tahoma;"><span style="unicode-bidi:embed"><span style="line-height:107%">Dysregulation of brain cholesterol homeostasis causes the accumulation of extracellular protein deposits called amyloid plaques in the hippocampus which eventually leads to neuronal death, memory and learning deficits. The aim of the present study was to investigate the effect of beta amyloid on miRNAs regulating HMGCR and ABCA1 as cholesterol synthesis and homeostasis genes. Primary astrocytes were isolated from C57BL/6J mice, and were treated with 0.5 &mu;M amyloid beta (A&beta;). Expression levels of genes and miRNAs were measured by real-time PCR. In comparison to control, A&beta; treatment resulted in a significant decrease in miR-96-5p expression as a positive and negative regulator of HMGCR and ABCA1, respectively. There was no significant increase in miR-27a-3p expression as a negative regulator of HMGCR. miR-106b-5p and miR-143-3p expressions were also dramatically decreased as ABCA1 negative regulators. Amyloid beta can alter the expression of major genes in the cholesterol homeostasis pathway via their regulatory miRNAs<span dir="RTL" lang="FA">.</span></span></span></span></span> ABCA1, HMGCR, microRNA, astrocytes, amyloid beta 30 39 http://ijmcmed.org/browse.php?a_code=A-10-6723-1&slc_lang=en&sid=1 Hossein Azizi Dariuni azizihosein88@gmail.com 100319475328460032673 100319475328460032673 No Department of Biochemistry, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Mehrnaz Karimi Darabi Mehrnaz.karimi6878@gmail.com 100319475328460032674 100319475328460032674 No Department of Biochemistry, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Zahra Nazeri zahranazeri47@yahoo.com 100319475328460032675 100319475328460032675 No Department of Biochemistry, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Shirin Azizidoost shirin_azizidoost@yahoo.com 100319475328460032676 100319475328460032676 No Atherosclerosis Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Alireza Kheirollah akheirollah@gmail.com 100319475328460032677 100319475328460032677 No Department of Biochemistry, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Azam Khedri azamkh1317@gmail.com 100319475328460032678 100319475328460032678 No Department of Biochemistry, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Maryam Cheraghzadeh cheraghzade_m@ajums.ac.ir 100319475328460032679 100319475328460032679 Yes Department of Biochemistry, School of Medicine, Cellular & Molecular Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.