Friday, January 23, 2009

Wednesday, January 14, 2009

24-OHC-27-OHC and Alzheimer's

Dr. Othman Ghribi and his team at University of North Dakota have just published interesting results regarding the relationship between 24-hydroxycholesterol (24-OHC) and 27-hydroxycholesterol (27-OHC).

27-OHC increased levels of amyloid precursor protein (APP) as well as beta-secretase (BACE1)
the enzyme that cleaves APP to yield Abeta, a molecule that causes alzheimer's.

24-OHC are associated with increased levels of sAPPalpha, suggesting that 24-OHC favors the processing of APP to the non-amyloidogenic pathway.

Futher study of this relationship between 27 and 24-OHC could yield possible targets for decreasing the cleavage of alzheimer's causing proteins and result in more step towards the Azheimer's therapies.

Here's the publication.

Prasanthi JRP, Huls A, Thomasson S, Thompson A, Schommer E, Ghribi O. Differential effects of 24-hydroxycholesterol and 27-hydroxycholesterol on beta-amyloid precursor protein levels and processing in human neuroblastoma SH-SY5Y cells. Molecular Neurodegeneration 2009, 4:1 (6 January 2009).

Image:
Treatment with 24-OHC, but not with 27-OHC, increased ABCA1 and ABCG1 levels. Representative Western blots

Monday, January 12, 2009

December 2008 Featured Pubs

Intrathecal Delivery of siRNA

Another publication referencing successful delivery of siRNA using i-Fect

Suneeta Tumati, Tally Largent Milnes, Henry I. Yamamura, Todd W. Vanderah, William R. Roeske and Eva V. Varga. Intrathecal Raf-1-selective siRNA attenuates sustained morphine-mediated thermal hyperalgesia. doi:10.1016/j.ejphar.2008.10.033

...siRNAs stock solutions (100 ?M) were prepared in double distilled RNAse free water and stored in aliquots at ?80 °C. For intrathecal treatment, aliquots of the stock solution (2 ?g of the appropriate siRNA) were mixed (1:5 v/v)with i-Fect transfection reagent (Neuromics, Edina, MN). After recovery from the surgery (5-7 days), the animals received intrathecal injections (2 ug! siRNA/1 0 ul/rat) of either a lipid encapsulated Raf-1-selective siRNA mixture (Smart pool siRNA, Dharmacon Inc; Chicago, IL, Cat # L-087699-00) (Raf-1 siRNA groups) or i-Fect encapsulated non-targeting dsRNA (Dharmacon, #D-001810-01-20) (control mismatch siRNA groups) or the transfection lipid alone, once daily, for 3 days, as described earlier (Gardell et al., 2002). Intrathecal injections of the siRNAs or the transfection agent alone did not cause any sign of behavioral toxicity. Western blots, using a Raf-1-selective antibody, indicated that intrathecal treatment with the Raf-1-selective siRNA mixture for 3 days significantly reduced Raf-1 protein levels in the dorsal root ganglion and in the dorsal horn of the spinal cord..

Lasani S. Wijetunge, Sally M. Till, Thomas H. Gillingwater, Cali A. Ingham, and Peter C. Kind. mGluR5 Regulates Glutamate-Dependent Development of the Mouse Somatosensory Cortex. The Journal of Neuroscience, December 3, 2008, 28(49):13028-13037; doi:10.1523/JNEUROSCI.2600-08.2008.
...Western blotting was performed as mentioned above and membranes were probed with antibodies against mGluR5 (1:4000, Neuromics)...