Mitochondrial Health, Physical Functioning, and Daily Affect: Bioenergetic Mechanisms of Dementia Caregiver Well-Being.

OBJECTIVE: Chronic stress adversely affects mental and physical well-being. However, health outcomes vary among people experiencing the same stressor. Individual differences in physical and emotional well-being may depend on mitochondrial biology, as energy production is crucial for stress regulation. This study investigated whether mitochondrial respiratory capacity corresponds to individual differences in dementia spousal caregivers' mental and physical health. METHODS: Spousal caregivers of individuals with Alzheimer's disease and related dementias ( N = 102, mean age = 71, 78% female, 83% White) provided peripheral blood samples and completed self-report questionnaires on quality of life, caregiver burden, and a 7-day affect scale. Multiple and mixed linear regressions were used to test the relationship between mitochondrial biology and well-being. RESULTS: Spare respiratory capacity ( b = 12.76, confidence interval [CI] = 5.23-20.28, p = .001), maximum respiratory capacity ( b = 8.45, CI = 4.54-12.35, p < .0001), and ATP-linked respiration ( b = 10.11, CI = 5.05-15.18, p = .0001) were positively associated with physical functioning. At average ( b = -2.23, CI = -3.64 to -0.82, p = .002) and below average ( b = -4.96, CI = -7.22 to 2.70, p < .0001) levels of spare respiratory capacity, caregiver burden was negatively associated with daily positive affect. At above average levels of spare respiratory capacity, caregiver burden was not associated with positive affect ( p = .65). CONCLUSIONS: Findings suggest that higher mitochondrial respiratory capacity is associated with better psychological and physical health-a pattern consistent with related research. These findings provide some of the earliest evidence that cellular bioenergetics are related to well-being.

Nasal administration of mesenchymal stem cells reverses chemotherapy-induced peripheral neuropathy in mice.

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most frequently reported adverse effects of cancer treatment. CIPN often persists long after treatment completion and has detrimental effects on patient's quality of life. There are no efficacious FDA-approved drugs for CIPN. We recently demonstrated that nasal administration of mesenchymal stem cells (MSC) reverses the cognitive deficits induced by cisplatin in mice. Here we show that nasal administration of MSC after cisplatin- or paclitaxel treatment- completely reverses signs of established CIPN, including mechanical allodynia, spontaneous pain, and loss of intraepidermal nerve fibers (IENF) in the paw. The resolution of CIPN is associated with normalization of the cisplatin-induced decrease in mitochondrial bioenergetics in DRG neurons. Nasally administered MSC enter rapidly the meninges of the brain, spinal cord and peripheral lymph nodes to promote IL-10 production by macrophages. MSC-mediated resolution of mechanical allodynia, recovery of IENFs and restoration of DRG mitochondrial function critically depends on IL-10 production. MSC from IL-10 knockout animals are not capable of reversing the symptoms of CIPN. Moreover, WT MSC do not reverse CIPN in mice lacking IL-10 receptors on peripheral sensory neurons. In conclusion, only two nasal administrations of MSC fully reverse CIPN and the associated mitochondrial abnormalities via an IL-10 dependent pathway. Since MSC are already applied clinically, we propose that nasal MSC treatment could become a powerful treatment for the large group of patients suffering from neurotoxicities of cancer treatment.