Antagonistic effects of ultra-low-molecular-weight heparin on Aβ25–35-induced apoptosis in cultured rat cortical neurons

Low-molecular-weight heparin (LMWH) and ultra-low-molecular-weight heparin (ULMWH) are heparin's derivatives, having various pharmacological effects. The present study aims to investigate the effect of ULMWH on amyloid β peptide (Aβ25–35)-induced neurotoxicity in cultured rat cortical neurons, and LMWH was employed as a positive control agent. The neurons were incubated with Aβ25–35 (35 μM), Aβ25–35 plus ULMWH (2, 10, 50 μg/ml) or LMWH (10 μg/ml) for 24 h. The cell viability was assessed by MTT and LDH release. FITC-Annexin V/PI double staining, Hoechst 33258 staining, TUNEL and Western blotting for bcl-2 and caspase-3 were employed to measure the neuron apoptosis. Furthermore, the intracellular Ca2+ concentration was measured by a fluorescent dye, Fura-2/AM. The results showed that ULMWH significantly increased cell viability and the protein expression levels of bcl-2 and decreased the LDH release, the number of apoptotic cells, the concentration of intracellular Ca2+ and the protein expression levels of caspase-3 in cortical neurons, suggesting that ULMWH can obviously reduce Aβ25–35-induced neurotoxic effects and might act as a potential agent for Alzheimer's disease.

Research highlights
► ULMWH seems to cross the BBB and cause lower risk of bleeding.
► It is the first study about the beneficial effects of ULMWH on Aβ induced apoptosis.
► The mechanism may be partly attributed to modulating calcium homeostasis.
► ULMWH might act as a neuroprotective agent in the prevention and treatment in AD.