Introduction: Amyloid plaques, mainly comprising of amyloid-beta peptides derived from its precursor protein, are found deposited in hippocampal and entorhinal cortical regions of patients with Alzheimer’s disease (AD). However, none led to a complete understanding of the molecular mechanisms of the AD in order to generate a new therapy that would eradicate the disease effectively. Activation of pro-apoptotic pathway was found to be associated with the accumulation of amyloid precursor protein (APP). The objective of this study is to examine theeffects of APP overexpression on the Bcl-2 family proteins involving in pro-apoptotic pathway in neuronal cells. Methods: The experiment was first performed with the transfection of HEK 293T cells for generation of lentiviral vector system consisting APP plasmid followed by transduction of SH-SY5Y neuronal cells using lentivirus generated. Subsequently, western blot analysis was conducted to validate the APP overexpression in SH-SY5Y cells. Then, expression levels of Bcl-2 family proteins in the APP overexpressed cells were determined by western blot analysis. The statistical analysis was performed by Microsoft Excel with Student’s t-test. Results: APP overexpression in SH-SY5Y cells slightly upregulated the pro-apoptotic proteins including Bad, Bid, Bok and Puma but slightly downregulated Bcl-2, Bim and Bax. Conclusion: Our data suggest that APP overexpression regulated the Bcl-2-mediated pathway by a significant downregulation of Bim protein in neuronal cells.
Introduction: The aging process is the most significant risk factor for developing Alzheimer’s disease (AD). AD is the most common neurodegenerative disease that causes cognitive and memory impairment in the elderly. Excessive build-up of amyloid protein leads to cell death, brain atrophy, and cognitive and functional decline in AD. The nuclear factor kappa beta (NF-κB) is a family of inducible transcription factors composed of NF-κB1, NF-κB2, RelA, RelB and c-Rel. It is activated by genotoxic agents, as well as oxidative and inflammatory stresses. It regulates expression of genes that control apoptosis, cell cycle progression, cell senescence, and inflammation. NF-κB regulates amyloid precursor protein (APP) processing by activating transcription of β and γ secretases, which promotes amyloid dysregulation in AD. In addition, NF-κB activation is linked with many of the known lifespan regulators including insulin/IGF- 1, FOXO, SIRT, and mTOR. Therefore, NF-κB pathway contributes to the pathophysiology of AD. This study aims to evaluate the effects of APP overexpression on NF-κB pathway in neuronal cells. Methods: SH-SY5Y neuronal cells were transduced with APP plasmid. Overexpression of APP in the cells was validated by western blotting. Western blot analysis using antibodies targeting NF-κB signalling pathway was performed using the APP-overexpressed cells. Results: Overexpression of APP in cells caused a significant down-regulation of phosphorylated NF-κB. Overexpression of APP also slightly up-regulated IkappaB-alpha, IKK alpha, and IKK beta. Conclusion: APP overexpression affected NF-κB pathway by down-regulating NF-κB protein.
Primary sacral tumours are rare, therefore experience of managing their associated complications are very limited. Effective surgical treatment of pelvic chondrosarcoma remains a major challenge for orthopaedic surgeons, due to the complex anatomic structure of the pelvis, the lack of defined compartment borders, the close vicinity to vital structures, and the risk of jeopardizing pelvic structural stability. We report a rare case of a giant sacral chondrosarcoma (100cm x 80cm) in an elderly male who successfully underwent tumour resection with good functional outcome and recovery. Long term follow up is essential in view of the possibility of local tumour recurrence.
Conventional chondrosarcomas rarely metastasize and it is extremely unusual to see multicentric- behaviour in malignant cartilage tumour. We report a 40 year old lady with presentation of two non-contiguous metachronous foci of low to intermediate grade of chondrosarcoma over left pelvic bone and right scalp respectively in the absence of pulmonary or visceral metastasis.