👤 Mark T Kearney

Randomized controlled trials (RCTs) found no cardioprotective effects of levothyroxine therapy in older adults with subclinical hypothyroidism. To assess levothyroxine effects on cardiometabolic biomarkers, which may serve as more sensitive treatment indicators. Post hoc analysis using (baseline and 12-month) data from two double-blind randomised controlled trials in older adults (≥ 65 years) with subclinical hypothyroidism. Cardiometabolic biomarkers included seven clinically relevant lipid measures (apolipoprotein B (ApoB), total cholesterol (Total-C), non-high-density lipoprotein cholesterol (non-HDL-C), remnant cholesterol (RC), low-density lipoprotein cholesterol (LDL-C), HDL-C, and triglycerides (TG)) and 167 standardised metabolomic measures from nuclear magnetic resonance. Analyses were additionally stratified by baseline TSH levels. Among 286 included participants (48% women; median age 75 [70, 82] years; median baseline TSH 6.44 [5.36, 7.81] mIU/L), 142 were randomized to levothyroxine. Overall, levothyroxine showed no effects on ApoB (-0.03 [95% CI: -0.07, 0.00] g/L), Total-C (-0.17 [-0.34, 0.00] mmol/L), non-HDL-C (-0.15 [-0.31, 0.00] mmol/L), RC (-0.09 [-0.16, -0.01] mmol/L), LDL-C (-0.07 [-0.15, 0.02] mmol/L), and TG (-0.07 [-0.15, 0.01] mmol/L). In participants with baseline TSH ≥10 mIU/L (n=27), potentially beneficial changes (P-values < 0.05, but not significant after multiple-testing correction) were observed for all clinically relevant lipids except HDL-C, as well as for ApoB-containing lipoproteins, VLDL size and fatty acids. In older adults with subclinical hypothyroidism, levothyroxine treatment showed no effects on cardiometabolic biomarkers, although potentially favourable changes in lipids and lipoproteins were observed for individuals with baseline TSH ≥ 10 mIU/L. Show less

Diabetes mellitus (DM) increases heart failure incidence and worsens prognosis, but its molecular basis is poorly defined in humans. We aimed to define the diabetic myocardial transcriptome and validate hits in their circulating protein form to define disease mechanisms and biomarkers. RNA-sequencing data from the Genotype-Tissue Expression (GTEx) project was used to define differentially expressed genes (DEGs) in right atrial (RA) and left ventricular (LV) myocardium from people with vs. without DM (type 1 or 2). DEGs were validated as plasma proteins in the UK Biobank cohort, searching for directionally concordant differential expression. Validated plasma proteins were characterized in UK Biobank participants, irrespective of diabetes status, using cardiac magnetic resonance imaging, incident heart failure, and cardiovascular mortality. We found 32 and 32 DEGs associated with DM in the RA and LV, respectively, with no overlap between these. Plasma proteomic data were available for 12, with ERBB3, NRXN3, and HSPA2 (all LV hits) exhibiting directional concordance. Irrespective of DM status, lower circulating ERBB3 and higher HSPA2 were associated with impaired LV contractility and higher LV mass. Participants in the lowest quartile of circulating ERBB3 or highest quartile of circulating HSPA2 had increased incident heart failure and cardiovascular death vs. all other quartiles. DM is characterized by lower Erbb3 and higher Hspa2 expression in the myocardium, with directionally concordant differences in their plasma protein concentration. These are associated with LV dysfunction, incident heart failure, and cardiovascular mortality. Show less

S-SCAM/MAGI-2 gene duplication is associated with schizophrenia (SCZ). S-SCAM overexpression in the forebrain induces SCZ-like phenotypes in a transgenic (Tg) mouse model. Interestingly, S-SCAM Tg mice show male-specific impairments in synaptic plasticity and working memory. However, mechanisms underlying the sex-specific deficits remain unknown. Here we report that S-SCAM Tg mice have male-specific deficits in synaptic GSK3β functions, as shown by reduced synaptic protein levels and increased inhibitory phosphorylation of GSK3β. This GSK3β hyper-phosphorylation was associated with increased CaMKII activities. Notably, synaptic levels of Axin1, to which GSK3β binds in competition with S-SCAM, were also reduced in male S-SCAM Tg mice. We demonstrated that Axin-binding is required for the S-SCAM overexpression-induced synaptic GSK3β reduction. Axin stabilization using XAV939 rescued the GSK3β deficits and restored the temporal activation of GSK3β during long-term depression in S-SCAM overexpressing neurons. Interestingly, synaptic Axin2 levels were increased in female S-SCAM Tg mice. Female sex hormone 17β-estradiol increased Axin2 expression and increased synaptic GSK3β levels in S-SCAM overexpressing neurons. These results reveal the role of S-SCAM in controlling Axin-dependent synaptic localization of GSK3β. Moreover, our studies point out the pathological relevance of GSK3β hypofunction found in humans and contribute to understanding the molecular underpinnings of sex differences in SCZ. Show less

A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples. The generation of an in frame MLL-AF10 fusion requires complex intra- and interchromosomal exchanges between chromosomes 10 and 11. In this case, an intrachromosomal rearrangement of chromosome 5 was also observed. This case illustrates the presence of systemic disease in extramedullary leukaemia, its response to systemic rather than topical therapy and suggests that the events leading to chromosomal translocations in leukaemia may be part of a generalized intracellular event. Show less