title: The relationship between estrogen receptors and microtubule dynamics in post-menopausal rat brain.
abstract: BACKGROUND
  Estrogen is one of the most important regulators of neuron function. There is a broad consensus that a loss of estrogen is associated with neurodegeneration in the hippocampus which leads to cognitive impairment. Hematopoietic-Pbx-interaction-protein (HPIP) is a novel scaffolding protein which interacts with microtubules and estrogen receptors. In this study, we investigated the presence and role of HPIP in hippocampal neurons and examined the relationship between estrogen receptors and microtubule damage in post-menopausal rat brains.
  
  
  METHODS
  Eighty female Wistar albino rats, 12 weeks old, were divided into 10 groups: control, control+17-β-estradiol, control+tamoxifen, control+mitogen-activated protein kinases (MAPK) inhibitor, control+phosphoinositide 3-kinase (PI3-K) inhibitor, ovariectomized, ovariectomized+17-β-estradiol, ovariectomized+tamoxifen, ovariectomized+MAPK inhibitor, and ovariectomized+PI3-K inhibitor. Light and electron microscopic examinations were performed. Real-time polymerase chain reaction (PCR) was used to determine the expression level of HPIP in experimental groups.
  
  
  RESULTS
  Light and electron microscopic examinations revealed morphological changes in hippocampal neuron axons. Axonal fluctuations and shrinkage were detected in all ovariectomized groups. HPIP was detected in all neurons with difference expression levels.
  
  
  CONCLUSIONS
  Proof that the HPIP protein can be found on hippocampal neurons may give rise to a new focus on neurodegeneration in post-menopausal women. Future molecular and pharmacological studies should be performed to reduce the rate of cognitive symptoms resulting from hippocampal neurodegeneration.
authors: Kafkas University, Medical Faculty, Department of Histology and Embryology, 36100 Kars, Turkey.
authors: Aksak Karamese
authors: AK
authors: Selina
authors: Kafkas University, Medical Faculty, Department of Microbiology, 36100 Kars, Turkey. Electronic address: murat_karamese@hotmail.com.
authors: Karamese
authors: K
authors: Murat
authors: Ataturk University, Veterinary Faculty, Department of Pharmacology and Toxicology, 25240 Erzurum, Turkey.
authors: Karakus
authors: K
authors: Emre
authors: Ataturk University, Medical Faculty, Department of Anatomy, 25240 Erzurum, Turkey.
authors: Malkoc
authors: M
authors: Ismail
authors: Ataturk University, Medical Faculty, Department of Histology and Embryology, 25240 Erzurum, Turkey.
authors: Unal
authors: U
authors: Bunyami
authors: Ataturk University, Medical Faculty, Department of Pathology, 25240 Erzurum, Turkey.
authors: Gundogdu
authors: G
authors: Cemal
mesh_terms: D000818:Animals; D005260:Female; D015870:Gene Expression; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D008870:Microtubules / Q000502:physiology*; D009410:Nerve Degeneration / Q000378:metabolism / Q000382:microbiology*; D017698:Postmenopause; D017208:Rats, Wistar; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*
chemical_list: D011960:Receptors, Estrogen
keywords: Axonal neurodegeneration; Estrogen receptors; HPIP; Microtubule; Ovariectomy