Using a mouse model of human MLL-AF9 leukemia, we identified the lysine-specific demethylase KDM1A (LSD1 or AOF2) as an essential regulator of leukemia stem cell (LSC) potential. KDM1A acts at genomic loci bound by MLL-AF9 to sustain expression of the associated oncogenic program, thus preventing differentiation and apoptosis. In vitro and in vivo pharmacologic targeting of KDM1A using tranylcypromine analogs active in the nanomolar range phenocopied Kdm1a knockdown in both murine and primary human AML cells exhibiting MLL translocations. By contrast, the clonogenic and repopulating potential of normal hematopoietic stem and progenitor cells was spared. Our data establish KDM1A as a key effector of the differentiation block in MLL leukemia, which may be selectively targeted to therapeutic effect.

SummaryPharmacologic inhibition of LSD1 promotes blast cell differentiation in acute myeloid leukemia (AML) with MLL translocations. The assumption has been that differentiation is induced through blockade of LSD1’s histone demethylase activity. However, we observed that rapid, extensive, drug-induced changes in transcription occurred without genome-wide accumulation of the histone modifications targeted for demethylation by LSD1 at sites of LSD1 binding and that a demethylase-defective mutant rescued LSD1 knockdown AML cells as efficiently as wild-type protein. Rather, LSD1 inhibitors disrupt the interaction of LSD1 and RCOR1 with the SNAG-domain transcription repressor GFI1, which is bound to a discrete set of enhancers located close to transcription factor genes that regulate myeloid differentiation. Physical separation of LSD1/RCOR1 from GFI1 is required for drug-induced differentiation. The consequent inactivation of GFI1 leads to increased enhancer histone acetylation within hours, which directly correlates with the upregulation of nearby subordinate genes.

Pre-clinical data supporting a therapeutic role for LSD1 inhibitors are most encouraging in acute myeloid leukaemia, although optimal dosing strategies and beneficial combinations with other agents remain unclear. Studies making use of potent, selective LSD1 inhibitors active in the nanomolar range are required to establish therapeutic indications in other subtypes of haematological malignancy, and in solid tumours.

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Implementation of a pharmacist-led, multidisciplinary DMT helped to achieve intensive glycemic control in CABG patients and decrease the rate of infection.

Background: Male workers in the US construction industry have a higher suicide rate than other workers in the nation. However, related research on this population remains sparse. This study evaluated psychological distress and suicidal ideation in these workers, and possible underlying factors. Methods: Data from the National Survey of Drug Use and Health from 2008 to 2014 were analyzed. Stratified and multiple logistic regression analyses were conducted to examine factors associated with psychological distress and suicidal ideation among male construction workers aged ≥18 years (n = 12,034).Results: Nearly one-third (29.6%) of male construction workers in the United States experienced psychological distress (23.8% graded as moderate, 5.8% as severe), and 2.5% reported suicidal ideation in the past year. Higher odds of serious psychological distress and suicidal ideation were found among workers who were younger, worked part-time, missed workdays due to injury or illness, or were in poor health. Illicit opioid use (odds ratio [OR] = 1.87, 95% confidence interval [CI]: 1.22-2.89) and alcohol dependence or abuse (OR = 2.64, 95% CI: 1.74-3.99) significantly escalated the odds of suicidal ideation. The odds of suicidal ideation among workers with serious psychological distress were 33 times higher than those having no or minor psychological distress (OR = 32.91, 95% CI: 19.82-54.65) when other factors were constant.Conclusions: Occupational and nonoccupational factors were associated with constructionworkers' psychological distress and suicidal ideation. Both illicit opioid use and alcohol dependence or abuse were risk factors, and psychological distress was a strong predictor for suicidal ideation. To improve workers' mental health, it is necessary to integrate workplace injury prevention with illicit opioid-use reduction programs and suicide prevention.

The blood–brain barrier (BBB) is the interface between the central nervous system and systemic circulation. It tightly regulates what enters and is removed from the brain parenchyma and is fundamental in maintaining brain homeostasis. Increasingly, the BBB is recognised as having a significant role in numerous neurological disorders, ranging from acute disorders (traumatic brain injury, stroke, seizures) to chronic neurodegeneration (Alzheimer’s disease, vascular dementia, small vessel disease). Numerous approaches have been developed to study the BBB in vitro, in vivo, and ex vivo. The complex multicellular structure and effects of disease are difficult to recreate accurately in vitro, and functional aspects of the BBB cannot be easily studied ex vivo. As such, the value of in vivo methods to study the intact BBB cannot be overstated. This review discusses the structure and function of the BBB and how these are affected in diseases. It then discusses in depth several established and novel methods for imaging the BBB in vivo, with a focus on MRI, nuclear imaging, and high-resolution intravital fluorescence microscopy.

Lysine Specific Demethylase 1 (LSD1 or KDM1A) is one of a number of epigenetic regulators which have recently emerged as candidate therapeutic targets in acute myeloid leukaemia (AML). It is a flavin adenine dinucleotide (FAD) dependent homolog of the amine oxidase family with an ability to demethylate monomethyl or dimethyl lysine 4 (K4) of histone H3, in addition to other substrates. Pharmacological inhibitors of LSD1 such as the tranylcypromine derivatives have already commenced evaluation in early phase clinical trials. While it has been widely assumed that these compounds promote differentiation of AML cells through inhibition of the demethylase activity of LSD1, the precise mechanisms by which LSD1 inhibitors function has not yet been determined. If changes in histone methylation are a central and critical mediator of the effects of LSD1 inhibitors in promoting AML cell differentiation, it would be expected that global changes in transcription would be tightly linked temporally to changes in histone methylation following drug treatment of cells. Through RNA sequencing and ChIP sequencing experiments performed in human THP1 AML cells treated for 24 hours with a potent and specific tranylcypromine-derivative LSD1 inhibitor (ORY86, trans-N-((2-methoxypyridin-3-yl)methyl)-2-phenylcyclopropan-1-amine), we have established that wholescale up regulation of a myeloid differentiation transcription programme occurs in the absence of any significant genome-wide changes in mono- and di-methyl H3K4 and H3K9 (which are key enzymatic targets of LSD1). Thus LSD1 inhibitor-induced up regulation of myeloid differentiation gene expression is not downstream of changes in histone methylation. We further demonstrated that non-enzymatic functions of LSD1 are essential in AML cells by expressing either wild-type (WT) or catalytically inactive LSD1 (K661A) in LSD1 knockdown (KD) THP1 cells. While LSD1 KD cells exhibit myeloid differentiation and loss of clonogenic potential, both the WT and mutant versions of LSD1 were able to rescue the in vitro clonogenic potential of KD cells to an equivalent extent. Thus the histone demethylase activity of LSD1 is not required to sustain AML blasts in an undifferentiated state. Comparison of the transcriptional consequences of LSD1 inhibition with the transcriptional consequences of transcription factor knockdown in THP1 AML cells using GSEA revealed that pharmacological inhibition of LSD1 mimics depletion of GFI1. Immunoprecipitation experiments confirmed the previously described physical association of GFI1 with LSD1. Critically, the physical interactions of LSD1 with GFI1 was reversed by pharmacological inhibition of LSD1 with ORY86. Furthermore, in ChIP sequencing experiments drug treatment led to dissociation of LSD1 from promoters and enhancers. By contrast, there was no disruption of the endogenous level interaction of LSD1 with RCOR1, HDAC1 and HDAC2 (i.e. the CoREST complex) following drug treatment. To determine whether the inhibitor-induced separation of LSD1 from GFI1 is required for induction of myeloid differentiation by ORY86, we performed experiments using a GFI1-LSD1 fusion construct expressed in THP1 cells under the control of a doxycycline-regulated promoter. This construct tethers LSD1 directly to the transcription factor and circumvents any drug induced physical separation. THP1 cells expressing GFI1-LSD1 were drug resistant (as determined by immunophenotyping and clonogenic potential), in contrast to control cells expressing GFI1, LSD1 or an empty vector in the same inducible system. Thus, drug-induced physical separation of GFI1 from LSD1 is required for THP1 AML cells to undergo differentiation. Our data support a model whereby the physical association of LSD1 with transcription factors such as GFI1 is essential to maintain the differentiation block in AML. Unexpectedly, tranylcypromine-derivative inhibitors target this novel scaffolding function of LSD1, rather than its histone demethylase activity, to promote differentiation of AML cells. Disclosures Lynch: Astra Zeneca: Employment. Ciceri:Oryzon Genomics: Employment. Somervaille:Oryzon Genomics: Research Funding; Imago Biosciences: Consultancy.