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Biology subjects

Tee, A.

Publications and source records attributed to Tee, A..

2 recordsLinked to original sources

Relative importance of MCL-1's Anti-Apoptotic versus Non-Apoptotic Functions in vivo

MCL-1 is an anti-apoptotic member of the BCL-2 protein family that ensures cell survival by blocking the intrinsic apoptotic cell death pathway1. MCL-1 is unique in being essential for early embryonic development and the survival of many cell types, including many cancer cells, which are not affected by the loss of the other anti-apoptotic BCL-2 family members1-4. Non-apoptotic functions of MCL-1 controlling mitochondrial ATP production and dynamics have been proposed to underlie this unique requirement for MCL-15-9. The relative contributions of the anti-apoptotic versus the non-apoptotic functions of MCL-1 in normal physiology have not been addressed. Here we replaced the coding sequence for MCL-1 with those for the anti-apoptotic proteins BCL-XL, BCL-2 or A1. We hypothesised that BCL-XL, BCL-2 and A1 may substitute for MCL-1 in the inhibition of apoptosis, but that they will not be able to replace MCL-1s non-apoptotic function. Strikingly, Mcl-1Bcl-xL/Bcl-xL and Mcl-1Bcl-2/Bcl-2 embryos survived to embryonic day 14.5, greatly surpassing the pre-implantation lethality of Mcl-1-/- embryos at E3.5. This demonstrates that the non-apoptotic functions of MCL-1 are dispensable for early development. However, at later stages of development and life after birth many cell types, particularly ones with high energy demand, were found to require both the anti-apoptotic and the non-apoptotic functions of MCL-1. These findings reveal the relative importance of these distinct functions of MCL-1 in physiology, providing important information for basic biology and the advancement of MCL-1 inhibitors in cancer therapy.

cell biology↗

Genetic overlap between psychiatric disorders and neuropsychiatric symptoms in HD

Huntingtons disease (HD) is an inherited neurodegenerative disorder caused by an expanded CAG repeat in the HTT gene. It is diagnosed following a standardized exam of motor control and often presents with cognitive decline and psychiatric symptoms. Recent studies have detected genetic loci modifying the age at onset of motor symptoms in HD, but genetic factors influencing cognitive and psychiatric presentations are unknown. We tested the hypothesis that psychiatric and cognitive symptoms in HD are influenced by the same common genetic variation as in the general population by constructing polygenic risk scores from large genome-wide association studies of psychiatric and neurodegenerative disorders, and of intelligence, and testing for correlation with the presence of psychiatric and cognitive symptoms in a large sample (n=5160) of HD patients. Polygenic risk score for major depression was associated specifically with increased risk of depression in HD, as was schizophrenia risk score with psychosis and irritability. Cognitive impairment and apathy were associated with reduced polygenic risk score for intelligence. In general, polygenic risk scores for psychiatric disorders, particularly depression and schizophrenia, are associated with increased risk of the corresponding psychiatric symptoms in HD, suggesting a common genetic liability. However, the genetic liability to cognitive impairment and apathy appears to be distinct from other psychiatric symptoms in HD. No associations were observed between HD symptoms and risk scores for other neurodegenerative disorders. These data provide a rationale for treatments effective in depression and schizophrenia to be used to treat depression and psychotic symptoms in HD.

genetics↗