Live-Imaging Centriole Amplification in Mouse Brain Multiciliated Cells

Multiciliated cells (MCC) display on their apical surface hundreds of beating cilia that propel physiological fluids. They line brain ventricles where they propel the cerebrospinal liquid, airways where they clear mucus and pathogens and reproductive ducts where they concentrate the sperm in males or drive the egg along the oviducts in females. Motile cilia are nucleated from basal bodies which are modified centrioles. MCC therefore evade centriole archetypal duplication program to make several hundreds and nucleate an identical number of motile cilia. Defects in this centriole amplification process lead to severe human pathologies called "ciliary aplasia" or "acilia syndrome" and more recently renamed "reduced generation of motile cilia" (RGMC). Patients with this syndrome present frequent hydrocephaly, lung failure, and subfertility. In this manuscript, we describe the protocol we developed and optimized over the years to live image the centriole amplification dynamics. We explain why mouse brain MCC is a good model and provide the tips to enable successful spatially and temporally resolved monitoring of this massive organelle reorganization.

A Prospective Study to Detect Immune Checkpoint Inhibitors Associated With Myocarditis Among Patients Treated for Lung Cancer

Background

Immune checkpoint inhibitors (ICIs) are widely used in lung cancer management. However, myocarditis, which is a rare, yet potentially severe adverse-related event associated with ICIs, could be under-reported.

Objectives

This study is aimed to prospectively evaluate the cumulative incidence rate of myocarditis, through systematic screening, among patients receiving ICIs for lung cancer.

Methods

All patients who received the first administration of ICIs for non-small cell (NSCLC) and small cell lung cancer (SCLC), between May and November 2020, in the pulmonary department of Bordeaux University Hospital, were included. Echocardiography (ECG), troponin-I, and natriuretic peptide dosages before ICIs' first administration and before each infusion were recorded. ECG and magnetic resonance imaging (MRI) were done additionally, in case of at least three times increase in troponin levels, ECG modifications, and the onset of cardiovascular symptoms. Second, if possible, coronarography than endomyocardial biopsy was assessed. The primary outcome was defined as ICIs related to myocarditis onset, while secondary outcomes included other cardiovascular events, disease-free, and overall survival.

Results

During the period of interest, 99 patients received their first infusion of ICIs for lung cancer (mean age 64 ± 9 years; 52 men, 67% with adenocarcinoma). Three cases of myocarditis without major adverse cardiac events (MACEs) occurred (two definite and one possible), and the mean duration between the first ICIs' administration and myocarditis onset was 144 ± 3 days. Median disease-free survival and overall survival were 169 [102; 233] days and 209 [147; 249] days, respectively.

Conclusion

In our study, systematic screening of myocarditis associated with ICIs leads to a more frequent incidence and a later onset than previously reported. None of them were severe. Additional prospective evidence is needed before we could adopt routine cardiac screening in unselected patients starting ICIs; however, these data shed new light on the risk of myocarditis associated with ICIs administration.

Glycaemic Variability and Hyperglycaemia as Prognostic Markers of Major Cardiovascular Events in Diabetic Patients Hospitalised in Cardiology Intensive Care Unit for Acute Heart Failure

(1) Background: Hyperglycaemia and hypoglycaemia are both emerging risk factors for cardiovascular disease. Nevertheless, the potential effect of glycaemic variability (GV) on mid-term major cardiovascular events (MACE) in diabetic patients presenting with acute heart failure (AHF) remains unclear. This study investigates the prognostic value of GV in diabetic patients presenting with acute heart failure (AHF). (2) Methods: this was an observational study including consecutive patients with diabetes and AHF between January 2015 and November 2016. GV was calculated using standard deviation of glycaemia values during initial hospitalisation in the intensive cardiac care unit. MACE, including recurrent AHF, new-onset myocardial infarction, ischaemic stroke and cardiac death, were recorded. The predictive effects of GV on patient outcomes were analysed with respect to baseline characteristics and cardiac status. (3) Results: In total, 392 patients with diabetes and AHF were enrolled. During follow-up (median (interquartile range) 29 (6−51) months), MACE occurred in 227 patients (57.9%). In total, 92 patients died of cardiac causes (23.5%), 107 were hospitalised for heart failure (27.3%), 19 had new-onset myocardial infarction (4.8%) and 9 (2.3%) had an ischaemic stroke. Multivariable logistic regression analysis showed that GV > 50 mg/dL (2.70 mmol/L), age > 75 years, reduced left ventricular ejection fraction (LVEF < 30%) and female gender were independent predictors of MACE: hazard ratios (HR) of 3.16 (2.25−4.43; p < 0.001), 1.54 (1.14−2.08; p = 0.005), 1.47 (1.06−2.07; p = 0.02) and 1.43 (1.05−1.94; p = 0.03), respectively. (4) Conclusions: among other well-known factors of HF, a GV cut-off value of >50 mg/dL was the strongest independent predictive factor for mid-term MACE in patients with diabetes and AHF.

Clinical profile and midterm prognosis of left ventricular thrombus in heart failure

Aims

We documented the midterm prognosis of left ventricular thrombus (LVT) in heart failure (HF) patients with dilated cardiomyopathy (DCM) and ischaemic cardiomyopathy (ICM). We aimed to characterize patients with LVT in the context of HF with reduced (≤40%) left ventricular ejection fraction and evaluate their risk for death and/or embolic events, overall, and specifically in patients with ischaemic or non‐ischaemic aetiology. We also intended to identify risk factors for LVT in patients with DCM.

Methods and results

We included all HF patients (N = 105, age 56 ± 13) admitted from 2005 to 2018 in our institution for LVT without significant valve disease/prosthesis, heart transplant/left ventricular assist device, congenital heart disease, or acute myocardial infarction. Our primary endpoint was the 1 year risk of the composite of all‐cause mortality (ACM) and symptomatic embolic events. Mean left ventricular ejection fraction was 23 ± 9%, and median BNP was 1795 pg/mL. Most (97%) patients were treated with vitamin K anticoagulants, and 64% had ICM. Symptomatic embolic events and/or ACM occurred in 20% of the population [embolic events (all within 30 days of LVT diagnosis) 15% and ACM 6%] and was similarly frequent in DCM or ICM (P > 0.05). Suspected/transient embolic events were more frequent in DCM (overall 13%; 29% in DCM vs. 5% in ICM, P < 0.01). Major bleeding occurred in 5% of patients. Left ventricular reverse remodelling occurred in 65% of patients, more frequently in DCM (86% in DCM vs. 65% in ICM, P = 0.02). In a case–control analysis matching DCM patients, BNP level was the only factor significantly associated with LVT (2447 pg/mL in LVT vs. 347 pg/mL, P < 0.001).

Conclusions

Patients with LVT have markedly high natriuretic peptides and experience a 20% 1 year risk for embolic events and/or death following diagnosis despite anticoagulant treatment. Most patients have favourable remodelling/recovery. As all symptomatic embolic events occurred within 30 days of LVT diagnosis, a very careful initial management is warranted.

Reliability in the identification of midbrain dopamine neurons

Brain regions typically contain intermixed subpopulations of neurons with different connectivity and neurotransmitters. This complicates identification of neuronal phenotypes in electrophysiological experiments without using direct detection of unique molecular markers. A prime example of this difficulty is the identification of dopamine (DA) neurons in the midbrain ventral tegmental area (VTA). Although immunocytochemistry (ICC) against tyrosine hydroxylase (TH) is widely used to identify DA neurons, a high false negative rate for TH ICC following ex vivo electrophysiology experiments was recently reported, calling into question the validity of comparing DA and non-DA VTA neurons based on post-hoc ICC. However, in whole cell recordings from randomly selected rat VTA neurons we have found that TH labeling is consistently detected in ∼55% of neurons even after long recording durations (range: 2.5–150 min). This is consistent with our prior anatomical finding that 55% of VTA neurons are TH(+). To directly estimate a false negative rate for our ICC method we recorded VTA neurons from mice in which EGFP production is driven by the TH promoter. All 12 EGFP(+) neurons recorded with a K-gluconate internal solution (as used in our rat recordings) were strongly labeled by TH ICC (recording duration 16.6±1.8 min). However, using recording electrodes with an internal solution with high Cl⁻ concentration reduced the intensity of TH co-labeling, in some cases to background (recording duration 16.7±0.9 min; n = 10). Thus TH is a highly reliable molecular marker for DA neurons in VTA patch clamp recordings provided compatible microelectrode solutions are used.