Plasma acylcarnitines and gut-derived aromatic amino acids as sex-specific hub metabolites of the human aging metabolome

Aging biology entails a cell/tissue deregulated metabolism that affects all levels of biological organization. Therefore, the application of "omic" techniques that are closer to phenotype, such as metabolomics, to the study of the aging process should be a turning point in the definition of cellular processes involved. The main objective of the present study was to describe the changes in plasma metabolome associated with biological aging and the role of sex in the metabolic regulation during aging. A high-throughput untargeted metabolomic analysis was applied in plasma samples to detect hub metabolites and biomarkers of aging incorporating a sex/gender perspective. A cohort of 1030 healthy human adults (45.9% females, and 54.1% males) from 50 to 98 years of age was used. Results were validated using two independent cohorts (1: n = 146, 53% females, 30-100 years old; 2: n = 68, 70% females, 19-107 years old). Metabolites related to lipid and aromatic amino acid (AAA) metabolisms arose as the main metabolic pathways affected by age, with a high influence of sex. Globally, we describe changes in bioenergetic pathways that point to a decrease in mitochondrial β-oxidation and an accumulation of unsaturated fatty acids and acylcarnitines that could be responsible for the increment of oxidative damage and inflammation characteristic of this physiological process. Furthermore, we describe for the first time the importance of gut-derived AAA catabolites in the aging process describing novel biomarkers that could contribute to better understand this physiological process but also age-related diseases.

The effect of external stimulation on functional networks in the aging healthy human brain

Understanding the brain changes occurring during aging can provide new insights for developing treatments that alleviate or reverse cognitive decline. Neurostimulation techniques have emerged as potential treatments for brain disorders and to improve cognitive functions. Nevertheless, given the ethical restrictions of neurostimulation approaches, in silico perturbation protocols based on causal whole-brain models are fundamental to gaining a mechanistic understanding of brain dynamics. Furthermore, this strategy could serve to identify neurophysiological biomarkers differentiating between age groups through an exhaustive exploration of the global effect of all possible local perturbations. Here, we used a resting-state fMRI dataset divided into middle-aged (N =310, <65 years) and older adults (N =310, $\geq $65) to characterize brain states in each group as a probabilistic metastable substate (PMS) space. We showed that the older group exhibited a reduced capability to access a metastable substate that overlaps with the rich club. Then, we fitted the PMS to a whole-brain model and applied in silico stimulations in each node to force transitions from the brain states of the older- to the middle-aged group. We found that the precuneus was the best stimulation target. Overall, these findings could have important implications for designing neurostimulation interventions for reversing the effects of aging on whole-brain dynamics.

Whole-Brain Dynamics in Aging: Disruptions in Functional Connectivity and the Role of the Rich Club

Normal aging causes disruptions in the brain that can lead to cognitive decline. Resting-state functional magnetic resonance imaging studies have found significant age-related alterations in functional connectivity across various networks. Nevertheless, most of the studies have focused mainly on static functional connectivity. Studying the dynamics of resting-state brain activity across the whole-brain functional network can provide a better characterization of age-related changes. Here, we employed two data-driven whole-brain approaches based on the phase synchronization of blood-oxygen-level-dependent signals to analyze resting-state fMRI data from 620 subjects divided into two groups (middle-age group (n = 310); age range, 50-64 years versus older group (n = 310); age range, 65-91 years). Applying the intrinsic-ignition framework to assess the effect of spontaneous local activation events on local-global integration, we found that the older group showed higher intrinsic ignition across the whole-brain functional network, but lower metastability. Using Leading Eigenvector Dynamics Analysis, we found that the older group showed reduced ability to access a metastable substate that closely overlaps with the so-called rich club. These findings suggest that functional whole-brain dynamics are altered in aging, probably due to a deficiency in a metastable substate that is key for efficient global communication in the brain.

Bariatric Surgery-Induced Changes in Intima-Media Thickness and Cardiovascular Risk Factors in Class 3 Obesity: A 3-Year Follow-Up Study

OBJECTIVE

The impact of weight loss induced by bariatric surgery (BS) and nonsurgical approaches on cardiovascular risk factors (CVRFs) has not been fully elucidated. We assessed the effects of BS and a nonsurgical approach on carotid intima-media thickness (CIMT) and CVRFs in participants with class 3 obesity.

METHODS

A total of 87 participants with obesity (59 women; 46 [37-52] years old; BMI, 43 [40-47]) and 75 controls were recruited; 21 (25%) participants with obesity underwent BS. BMI, blood pressure, cholesterol, triglycerides, fasting plasma glucose, C-reactive protein, CIMT, and Framingham Risk Score were measured at baseline and at 3-year follow-up. Independent factors for reduction in CIMT were analyzed. The literature on the effects of BS and CIMT was reviewed.

RESULTS

After BS, BMI decreased from 45.45 to 27.28 (P < 0.001), and mean CIMT decreased from 0.64 mm (0.56-0.75 mm) to 0.54 mm (0.46-0.65) mm (P < 0.012), equivalent to 0.005 mm/kg of weight lost. At 3-year follow-up, participants who had undergone BS had similar CIMT and CVRFs to the control group. No changes in CVRFs were seen related to the nonsurgical approach. BMI reduction after BS had the strongest independent association with decreased CIMT.

CONCLUSIONS

Weight loss after BS decreases CIMT and CVRFs in middle-aged participants with class 3 obesity, resulting in CIMT similar to that observed in lean participants.

Abstract P2-12-05: Neuropsychological assessment, neuroimaging, and tumor markers to explore cognitive decline in early stage breast cancer patients

Background. It is widely demonstrated that a high percentage of early stage breast cancer patients achieves a long-term survival. However, it seems that some of them show a cognitive decline during and after the oncology treatment, affecting their quality of life. Fortunately, the neuropsychological impairment in cancer patients is nowadays a known issue in oncology literature. Our aim is to assess the effects of chemotherapy and endocrine therapy on neurocognitive functions in patients with early stage breast cancer. If the hypothesis that the patients suffer from neurocognitive impairments related to the oncology treatment will be confirmed, this would imply the possibility of an early neuropsychological rehabilitation since the first diagnosis, to prevent the worsening of the quality of life and to avoid the use of additional medications to regulate for example the severity of fatigue and mood. Methods. The study population includes 45 patients diagnosed of breast cancer undergoing chemotherapy +/- endocrine treatment (CT), 15 patients undergoing endocrine treatment (HT), and 9 healthy controls (HC). Throughout each evaluation at three points time, we administered the Mini-Mental State Examination (MMSE), some tests of the Cogstateneurocognitive battery, the Trail Making Test (TMTA and TMTB), and the Controlled Oral Word Association Test (COWAT). Moreover, each subject was asked to complete the EORTC QLQ-C30 and the QLQ-BR23 quality of life tests, the MD Anderson Symptoms Inventory questionnaire, the Hospital Anxiety and Depression scale, and a self-report of the neurocognitive impairment perceived. In addition, we are performing a pilot neuroimaging study aimed to enroll 20 patients with early stage breast cancer, of whom 10 treated with chemotherapy, and 10 with hormone therapy alone. Patients undergo a structural and functional brain magnetic resonance imaging (fMRI). S100 protein, and neuro specific enolase are also collected to explore their possible relationship with the neurocognitive decline. Results. Both CT and HT Groups performed lower results than HC in visuo-motor processing speed test (TMTA) at baseline and at month 12 (p=0.00). At month 6 only the HT Group had lower results than HC (p=0.00). We found a correlation between the lower results of TMTA and the level of depression (p=0.02), distress (p=0.00), anxiety (p=0.01), severity of symptoms (p=0.00) in CT Group at baseline. The MMSE scores were slightly lower in both CT and HT Groups compared to HC (p=0.04) at month 6. The MMSE results at month 12 were lower in HT Groups compared to HC (p=0.04). In addition, the neurocognitive impairment perceived is higher in CT Group (p&lt;0.00) once having stopped the chemotherapy treatment until the last follow up. The results of TMTB and COWAT increased in CT Group during the last follow up (p=0.00), and it seems to have a positive correlation with the neurocognitive tasks the patients performed (p=0.02 and p=0.03 respectively). Concerning the pilot study, we analysed the first 10 patients enrolled in the study: 5 subjects treated with chemotherapy and 5 with hormone therapy alone. No statistically significant differences were found concerning the alteration of the tumor markers values. On the contrary, we found changes between the baseline and the post-treatment brain fMRI. Conclusions. Our results suggest a decline in few cognitive domains in cancer patients as consequence of the oncology treatment. In some tests the neurocognitive decline was also observed in cancer groups at baseline, and it was associated with the low state of mind in CT Group. We infer that the increasing of scores in CT Group at month 12 was positively associated with the cognitive tasks the patients were performing during the study-period.

Citation Format: Claudia Panciroli, Carles Biarnes, Josep Puig, Jose Anton Anton, Vanesa Quiroga, Eudald Felip, Beatriz Cirauqui, Margarita Romeo, Iris Teruel, Salvador Pedraza, Mireia Margeli. Neuropsychological assessment, neuroimaging, and tumor markers to explore cognitive decline in early stage breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-12-05.

Resting-State Functional Connectivity Magnetic Resonance Imaging and Outcome After Acute Stroke

Background and Purpose- Physiological effects of stroke are best assessed over entire brain networks rather than just focally at the site of structural damage. Resting-state functional magnetic resonance imaging can map functional-anatomic networks by analyzing spontaneously correlated low-frequency activity fluctuations across the brain, but its potential usefulness in predicting functional outcome after acute stroke remains unknown. We assessed the ability of resting-state functional magnetic resonance imaging to predict functional outcome after acute stroke. Methods- We scanned 37 consecutive reperfused stroke patients (age, 69±14 years; 14 females; 3-day National Institutes of Health Stroke Scale score, 6±5) on day 3 after symptom onset. After imaging preprocessing, we used a whole-brain mask to calculate the correlation coefficient matrices for every paired region using the Harvard-Oxford probabilistic atlas. To evaluate functional outcome, we applied the modified Rankin Scale at 90 days. We used region of interest analyses to explore the functional connectivity between regions and graph-computation analysis to detect differences in functional connectivity between patients with good functional outcome (modified Rankin Scale score ≤2) and those with poor outcome (modified Rankin Scale score >2). Results- Patients with good outcome had greater functional connectivity than patients with poor outcome. Although 3-day National Institutes of Health Stroke Scale score was the most accurate independent predictor of 90-day modified Rankin Scale (84.2%), adding functional connectivity increased accuracy to 94.7%. Preserved bilateral interhemispheric connectivity between the anterior inferior temporal gyrus and superior frontal gyrus and decreased connectivity between the caudate and anterior inferior temporal gyrus in the left hemisphere had the greatest impact in favoring good prognosis. Conclusions- These data suggest that information about functional connectivity from resting-state functional magnetic resonance imaging may help predict 90-day stroke outcome.

Diffusion tensor imaging as a prognostic biomarker for motor recovery and rehabilitation after stroke

PURPOSE

Despite improved acute treatment and new tools to facilitate recovery, most patients have motor deficits after stroke, often causing disability. However, motor impairment varies considerably among patients, and recovery in the acute/subacute phase is difficult to predict using clinical measures alone, particularly in severely impaired patients. Accurate early prediction of recovery would help rationalize rehabilitation goals and improve the design of trials testing strategies to facilitate recovery.

METHODS

We review the role of diffusion tensor imaging (DTI) in predicting motor recovery after stroke, in monitoring treatment response, and in evaluating white matter remodeling. We critically appraise DTI studies and discuss their limitations, and we explore directions for future study.

RESULTS

Growing evidence suggests that combining clinical scores with information about corticospinal tract (CST) integrity can improve predictions about motor outcome. The extent of CST damage on DTI and/or the overlap between the CST and a lesion are key prognostic factor that determines motor performance and outcome. Three main strategies to quantify stroke-related CST damage have been proposed: (i) measuring FA distal to the stroke area, (ii) measuring the number of fibers that go through the stroke with tractography, and (iii) measuring the overlap between the stroke and a CST map derived from healthy age- and gender-matched controls.

CONCLUSION

Recovery of motor function probably involves remodeling of the CST proper and/or a greater reliance on alternative motor tracts through spontaneous and treatment-induced plasticity. DTI-metrics represent promising clinical biomarkers to predict motor recovery and to monitor and predict the response to neurorehabilitative interventions.