Sleep fragmentation exacerbates myocardial ischemia‒reperfusion injury by promoting copper overload in cardiomyocytes

Sleep disorders increase the risk and mortality of heart disease, but the brain-heart interaction has not yet been fully elucidated. Cuproptosis is a copper-dependent type of cell death activated by the excessive accumulation of intracellular copper. Here, we showed that 16 weeks of sleep fragmentation (SF) resulted in elevated copper levels in the male mouse heart and exacerbated myocardial ischemia–reperfusion injury with increased myocardial cuproptosis and apoptosis. Mechanistically, we found that SF promotes sympathetic overactivity, increases the germination of myocardial sympathetic nerve terminals, and increases the level of norepinephrine in cardiac tissue, thereby inhibits VPS35 expression and leads to impaired ATP7A related copper transport and copper overload in cardiomyocytes. Copper overload further leads to exacerbated cuproptosis and apoptosis, and these effects can be rescued by excision of the sympathetic nerve or administration of copper chelating agent. Our study elucidates one of the molecular mechanisms by which sleep disorders aggravate myocardial injury and suggests possible targets for intervention.

For all statistical analyses, confirm that the following items are present in in the figure legend, table legend, main text, or or Methods section.

n/a Confirmed
The exact sample size (n) for each experimental group/condition, given as as a discrete number and unit of of measurement A statement on on whether measurements were taken from distinct samples or or whether the same sample was measured repeatedly The statistical test(s) used AND whether they are one-or or two-sided Only common tests should be described solely by name; describe more complex techniques in the Methods section.

A description of of all covariates tested
A description of of any assumptions or or corrections, such as as tests of of normality and adjustment for multiple comparisons A full description of of the statistical parameters including central tendency (e.g.means) or or other basic estimates (e.g.regression coefficient) AND variation (e.g. standard deviation) or or associated estimates of of uncertainty (e.g.confidence intervals) For null hypothesis testing, the test statistic (e.g.F, t, r) with confidence intervals, effect sizes, degrees of of freedom and P value noted Give P values as exact values whenever suitable.
For Bayesian analysis, information on on the choice of of priors and Markov chain Monte Carlo settings For hierarchical and complex designs, identification of of the appropriate level for tests and full reporting of of outcomes Estimates of of effect sizes (e.g.Cohen's d, Pearson's r), ), indicating how they were calculated Our web collection on statistics for biologists contains articles on many of the points above.

Software and code
Policy information about availability of of computer code Data collection

Data analysis
For manuscripts utilizing custom algorithms or or software that are central to to the research but not yet described in in published literature, software must be be made available to to editors and reviewers.We We strongly encourage code deposition in in a community repository (e.g.GitHub).See the Nature Portfolio guidelines for submitting code & software for further information.Confocal images were captured using Zeiss AirScan(LSM900) and Zeiss Apo Tome.2 with ZEN software (Carl Zeiss, v2009).Brightfield imaging was performed with a Nikon (N2Ti2-A) microscope and NIS-Elements Viewer software.Macroscopic fluorescence imaging of of heart tissue was conducted using the AKOYA VECTRA POLARIS multispectral pathology imaging system.Cardiac electrophysiology data was collected using telemetry implants (ADInstruments, MT MT 10B) and LabChart software (8.1.24).Cardiac ultrasound data was acquired and measured using the portable ultrasound diagnostic device, M9 M9 by by Mindray.Metal ion detection was performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) (Perkin Elmer NexION 2000).RT-qPCR data was collected using QuantStudio seven.Western blot bands were captured using the GE GE IMAGEQUANTMT 800 imaging system.
Softwares and scripts used are described in in the Methods section and listed below as as well.Data analysis: The analysis of of image data was performed using ImageJ(1.53a)and Fiji software (v2.9.0).The ultrasound data obtained from the M9 M9 by by Mindray was analyzed using Microsoft (Version 16.8) and GraphPad Prism software (Version 9.2.0).The cardiac electrophysiology data was analyzed using the HRV module in in LabChart (Version 8. 1.24).Data representation: Figures were prepared with GraphPad Prism 9.2.0,Adobe InDesign 2021, and Adobe Illustrator 2021.