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Biology subjects

Shliaha, P. V.

Publications and source records attributed to Shliaha, P. V..

2 recordsLinked to original sources

Mitochondrial dysfunction underlies monocyte immune deficiency in patients with severe alcohol-related hepatitis

Severe alcohol-related hepatitis (sAH) is a life-threatening form of alcohol-related liver disease (ARLD) associated with a significant short-term mortality. Opportunistic infections due to impaired immune function are a major cause of patient mortality. Mitochondrial dysfunction within the liver is a well-recognised feature of ARLD and sAH. However, whether these hepatic mitochondrial defects extend to the immune system of sAH patients, underlying their immune dysfunction, remains unclear. Here, we demonstrate that sAH monocytes exhibit an increased content of inefficient, dysfunctional mitochondria. These changes were underpinned by abnormal mitochondrial cristae ultrastructure, which were associated with depletion of cristae structural proteins and alterations in cardiolipin profiles. Overall, our study uncovers novel structural and functional mitochondrial defects, which likely contribute to impaired monocyte immune function in sAH.

immunology↗

Conserved helical motifs in the Ikaros IDR mediate NuRD interaction and transcriptional repression

The transcription factor IKZF1/Ikaros is essential for B cell development, and recurrently mutated in human B-ALL. Ikaros has been ascribed both activating and repressive functions via interactions with coactivator and corepressor complexes, but the relative abundance of Ikaros-associated coregulatory complexes and their contribution to Ikaros-mediated gene regulation are not well understood. To address this issue, we performed an unbiased identification of Ikaros-interacting proteins in pre-B cells, and found that Ikaros interacts overwhelmingly with corepressors and heterochromatin-associated proteins. Time-resolved analysis of transcription and chromatin state identified transcriptional repression as the immediate response to Ikaros induction. Transcriptional repression preceded transcriptional activation by several hours, and was accompanied by a rapid loss of chromatin accessibility and reduced levels of H3K27ac particularly at enhancers. Functional characterisation of intrinsically disordered regions in the Ikaros protein identified highly conserved helical motifs that mediate Ikaros association with the NuRD corepressor complex and contribute to the silencing of target genes in pre-B cells and antiproliferative functions of Ikaros in human B-ALL.

molecular biology↗