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Mitochondrial reactive oxygen species (ROS) are essential regulators of cellular signaling, metabolism and epigenetics underlying the pathophysiology of numerous diseases. Despite the critical function of redox regulation in mitochondria, currently there are limited methods available to monitor protein oxidation in this key subcellular organelle. Here, we describe compounds for imaging sulfenylated proteins in mitochondria: DCP-NEt2-Coumarin (DCP-NEt2C) and rhodamine-based DCP-Rho1. Side-by-side comparison studies are presented on the reactivity of DCP-NEt2C and DCP-Rho1 with a model protein sulfenic acid (AhpC-SOH) and mitochondrial localization to identify optimized experimental conditions for labeling and visualization of protein sulfenylation that would be independent of mitochondria membrane potential and would not impact mitochondrial function. These probes are applied to image mitochondrial protein sulfenylation under conditions of serum starvation and in a cell culture model of lung cancer exposed to ionizing radiation and silver nanoparticles, agents serving dual functions as environmental stressors and cancer therapeutics.

Background: Radiation therapy is an integral component of treatment that can predispose to carotid artery stenosis (CAS) and increase the risk of cerebrovascular events for head and neck cancer survivors. The utility of screening for CAS with carotid ultrasound in asymptomatic head and neck cancer survivors is unclear. Methods: In this prospective, cross-sectional pilot study, 60 patients who have no evidence of cancer at least 2 years from completion of RT will undergo screening carotid ultrasound to identify patients with high risk of cardiovascular events. Results: Outcomes will include clinically significant CAS, carotid intima-media thickness, acceptability/feasibility of screening, barriers to care and preliminary data on changes to medical management because of screening. Correlative multi-omics analyses will examine biomarkers of CAS after radiation therapy. Conclusion: The results of this study will provide valuable data on the prevalence of CAS and preliminary patient-centered data that will inform the design of a future large-scale, multi-site clinical trial. Clinical Trial Registration:NCT05490875 (ClinicalTrials.gov) Plain Language Summary Patients with head and neck cancer are often treated with radiation therapy. Radiation therapy can cause damage to the blood vessels in the neck. This damage can manifest as narrowing of the blood vessels like the carotid artery, which can lead to stroke. Currently, it is not clear if screening head and neck cancer survivors with ultrasound scans of the carotid arteries is feasible or acceptable to patients. This has also not been formally assessed using a prospective clinical trial. In this study, patients with a history of head and neck cancer who have no evidence of their cancer for at least 2 years since completion of their radiation therapy will be enrolled. They will undergo blood testing and a research ultrasound of the carotid arteries to check for narrowing and other findings that may signal a high risk of stroke or another cardiovascular event. Participants will complete surveys on their experience with the process and how likely they are to accept further screening or additional treatment if something is found. They will also complete surveys on their perception of their personal risk of stroke and barriers to care that would prevent them from getting screening ultrasounds. Patients will be followed for up to 6 months after the ultrasound to check for any changes in their medical care that occurred because of the screening ultrasound. Article highlights Carotid artery stenosis in head & neck cancer survivors treated with radiation therapy Radiotherapy for head and neck (HN) cancer may increase the risk of accelerated atherosclerosis and late carotid artery stenosis (CAS) in 25% of patients, and screening of asymptomatic stenosis may be useful and cost-effective in specific high-risk populations. If clinically significant stenosis is identified, risk reduction strategies such as optimal medical management with or without procedural intervention may reduce the risk of stroke. Data supporting the use of carotid ultrasound (CUS) for HN cancer survivors are sparse, and no guideline currently recommends CUS screening for asymptomatic patients. Carotid ultrasound surveillance for detection of asymptomatic carotid artery stenosis after head & neck radiotherapy CUS allows for cardiovascular risk stratification using stenosis and intima-media thickness measurements. Knowledge gaps with regard to the use of CUS screening in this population include patient acceptability, feasibility, and clinical utility. Rates of change in medical management for screen-detected carotid stenosis in HN cancer survivors have not been assessed in a prospective study. Pilot trial of carotid artery ultrasound in head & neck cancer survivors In this single-institution trial, 60 patients with a history of HN cancer treated with radiotherapy will undergo screening CUS. Patients will be evaluated for CAS (peak systolic velocity by Doppler ultrasonography), and intima-media thickness will be measured. Outcomes include patient acceptability, feasibility, barriers to care and perceived stroke risk among participants. In patients with clinically significant stenosis, the rate of resultant medical interventions (e.g., new medication, additional imaging or intervention) will be determined. Conclusion This prospective study for CUS screening in HN cancer survivors will obtain novel preliminary data to better understand the utility and feasibility of a CUS screening program. Preliminary results will inform future trials focused on the efficacy and cost-effectiveness of carotid artery ultrasound screening in this patient population. Correlative analysis will elucidate novel biomarkers and mechanisms of post-radiotherapy CAS. [ABSTRACT FROM AUTHOR]

Introduction Alzheimer's disease (AD) is the most common form of dementia and has become a global threat to public health. Currently, there is no effective intervention for curing AD or [...], AMPK is a key regulator at the molecular level for maintaining energy metabolism homeostasis. Mammalian AMPK is a heterotrimeric complex, and its catalytic [alpha] subunit exists in 2 isoforms: AMPK[alpha]1 and AMPK[alpha]2. Recent studies suggest a role of AMPK[alpha] overactivation in Alzheimer's disease-associated (AD-associated) synaptic failure. However, whether AD-associated dementia can be improved by targeting AMPK remains unclear, and roles of AMPK[alpha] isoforms in AD pathophysiology are not understood. Here, we showed distinct disruption of hippocampal AMPK[alpha] isoform expression patterns in postmortem human AD patients and AD model mice. We further investigated the effects of brain- and isoform-specific AMPK[alpha] repression on AD pathophysiology. We found that repression of AMPK[alpha]1 alleviated cognitive deficits and synaptic failure displayed in 2 separate lines of AD model mice. In contrast, AMPK[alpha]2 suppression did not alter AD pathophysiology. Using unbiased mass spectrometry-based proteomics analysis, we identified distinct patterns of protein expression associated with specific AMPK[alpha] isoform suppression in AD model mice. Further, AD-associated hyperphosphorylation of eukaryotic elongation factor 2 (eEF2) was blunted with selective AMPK[alpha]1 inhibition. Our findings reveal isoform-specific roles of AMPK[alpha] in AD pathophysiology, thus providing insights into potential therapeutic strategies for AD and related dementia syndromes.

Aims: This study aimed to characterize the properties of locus coeruleus (LC) noradrenergic neurons in male and female mice. We also sought to investigate sex‐specific differences in membrane properties, action potential generation, and protein expression profiles to understand the mechanisms underlying neuronal excitability variations. Methods: Utilizing a genetic mouse model by crossing Dbhcre knock‐in mice with tdTomato Ai14 transgenic mice, LC neurons were identified using fluorescence microscopy. Neuronal functional properties were assessed using patch‐clamp recordings. Proteomic analyses of individual LC neuron soma was conducted using mass spectrometry to discern protein expression profiles. Data are available via ProteomeXchange with identifier PXD045844. Results: Female LC noradrenergic neurons displayed greater membrane capacitance than those in male mice. Male LC neurons demonstrated greater spontaneous and evoked action potential generation compared to females. Male LC neurons exhibited a lower rheobase and achieved higher peak frequencies with similar current injections. Proteomic analysis revealed differences in protein expression profiles between sexes, with male mice displaying a notably larger unique protein set compared to females. Notably, pathways pertinent to protein synthesis, degradation, and recycling, such as EIF2 and glucocorticoid receptor signaling, showed reduced expression in females. Conclusions: Male LC noradrenergic neurons exhibit higher intrinsic excitability compared to those from females. The discernible sex‐based differences in excitability could be ascribed to varying protein expression profiles, especially within pathways that regulate protein synthesis and degradation. This study lays the groundwork for future studies focusing on the interplay between proteomics and neuronal function examined in individual cells. [ABSTRACT FROM AUTHOR]