[Show abstract][Hide abstract]ABSTRACT: AAV5-QBP1 inhibits polyQ inclusion body formation in virus infected neurons of polyQ disease mice. R6/2 mice at P7 were injected with AAV5-GFP on one side of the striatum and AAV5-QBP1 on the other side, and at 4, 8, and 14 weeks of age htt inclusion body formation in virus infected neurons of the striatum (left) and cortex (right) was assessed by immunohistochemistry. Data are shown as means ± SEM of ≥ 6 fields of view, in which over 180 cells were counted (*p<0.05, ***p<0.001). Representative results of two mice analyzed are shown.
[Show abstract][Hide abstract]ABSTRACT: AAV5 injection into the mouse striatum at P7 results in widespread expression of the transgene. R6/2 mice at P7 were injected in the right striatum with 1 µl of AAV5-QBP1, and 2 weeks later the expression of QBP1 was analyzed by immunohistochemistry. This widespread expression of QBP1 throughout the brain lasts for at least 13 weeks (data not shown).
[Show abstract][Hide abstract]ABSTRACT: AAV5 “infected” and “non-infected” cells can be clearly distinguished from their fluorescence intensity. The fluorescence intensity of representative cells that were regarded as either “infected” or “non-infected” in photographs of immunostained brain sections of R6/2 mice injected with either AAV5-GFP (left), AAV5-QBP1 (middle) or AAV5-Hsp40 (right). For each sample, a total of over 100 representative cells were analyzed from 5–6 fields of view.
[Show abstract][Hide abstract]ABSTRACT: The polyglutamine (polyQ) diseases such as Huntington's disease (HD), are neurodegenerative diseases caused by proteins with an expanded polyQ stretch, which misfold and aggregate, and eventually accumulate as inclusion bodies within neurons. Molecules that inhibit polyQ protein misfolding/aggregation, such as Polyglutamine Binding Peptide 1 (QBP1) and molecular chaperones, have been shown to exert therapeutic effects in vivo by crossing of transgenic animals. Towards developing a therapy using these aggregation inhibitors, we here investigated the effect of viral vector-mediated gene therapy using QBP1 and molecular chaperones on polyQ disease model mice. We found that injection of adeno-associated virus type 5 (AAV5) expressing QBP1 or Hsp40 into the striatum both dramatically suppresses inclusion body formation in the HD mouse R6/2. AAV5-Hsp40 injection also ameliorated the motor impairment and extended the lifespan of R6/2 mice. Unexpectedly, we found even in virus non-infected cells that AAV5-Hsp40 appreciably suppresses inclusion body formation, suggesting a non-cell autonomous therapeutic effect. We further show that Hsp40 inhibits secretion of the polyQ protein from cultured cells, implying that it inhibits the recently suggested cell-cell transmission of the polyQ protein. Our results demonstrate for the first time the therapeutic effect of Hsp40 gene therapy on the neurological phenotypes of polyQ disease mice.
[Show abstract][Hide abstract]ABSTRACT: Obesity results from the dysregulation of energy balance throughout the entire body. Although the ubiquitin system participates in many cellular processes, its contribution to the balance of energy in the body remains poorly understood. Here, we show that ubiquitin C-terminal hydrolase (UCH)-L3, one of the deubiquitinating enzymes, contributes to the regulation of metabolism. Uchl3(-/-) mice displayed a reduction of adipose tissue mass and were protected against high-fat diet (HFD)-induced obesity and insulin resistance. Uchl3(-/-) mice given both a normal chow and an HFD had an increased whole-body energy expenditure accounting for the reduction of adipose tissue mass. Activation of AMP-activated protein kinase (AMPK) in skeletal muscle has been reported to increase fatty acid beta-oxidation, leading to the elevation of the whole-body energy expenditure. Consistently, increased activation of AMPK and fatty acid beta-oxidation was observed in skeletal muscle of Uchl3(-/-) mice. Mouse embryonic fibroblasts derived from Uchl3(-/-) mice also showed increased activation of AMPK, indicating that UCH-L3 is involved in a cell-autonomous down-regulation of AMPK. These results suggest a role for UCH-L3 in the regulation of AMPK activity and whole-body energy metabolism.
Full-text · Article · Sep 2009 · The FASEB Journal