Background: Neuroinflammation, typified by elevated levels of interleukin-1 (IL-1) α and β, and deficits in proteostasis, characterized by accumulation of polyubiquitinated proteins and other aggregates, are associated with neurodegenerative disease independently and through interactions of the two phenomena. We investigated the influence of IL-1β on ubiquitination via its impact on activation of the E3 ligase parkin by either phosphorylated ubiquitin (P-Ub) or NEDD8. Methods: Immunohistochemistry and Proximity Ligation Assay were used to assess colocalization of parkin with P-tau or NEDD8 in hippocampus from Alzheimer patients (AD) and controls. IL-1β effects on PINK1, P-Ub, parkin, P-parkin, and GSK3β—as well as phosphorylation of parkin by GSK3β—were assessed in cell cultures by western immunoblot, using two inhibitors and siRNA knockdown to suppress GSK3β. Computer modeling characterized the binding and the effects of P-Ub and NEDD8 on parkin. IL-1α, IL-1β, and parkin gene expression was assessed by RT-PCR in brains of 2- and 17-month-old PD-APP mice and wild-type littermates. Results: IL-1α, IL-1β, and parkin mRNA levels were higher in PD-APP mice compared with wild-type littermates, and IL-1α-laden glia surrounded parkin- and P-tau-laden neurons in human AD. Such neurons showed a nuclear-to-cytoplasmic translocation of NEDD8 that was mimicked in IL-1β-treated primary neuronal cultures. These cultures also showed higher parkin levels and GSK3β-induced parkin phosphorylation; PINK1 levels were suppressed. In silico simulation predicted that binding of either P-Ub or NEDD8 at a singular position on parkin opens the UBL domain, exposing Ser₆₅ for parkin activation. Conclusions: The promotion of parkin- and NEDD8-mediated ubiquitination by IL-1β is consistent with an acute neuroprotective role. However, accumulations of P-tau and P-Ub and other elements of proteostasis, such as translocated NEDD8, in AD and in response to IL-1β suggest either over-stimulation or a proteostatic failure that may result from chronic IL-1β elevation, easily envisioned considering its early induction in Down’s syndrome and mild cognitive impairment. The findings further link autophagy and neuroinflammation, two important aspects of AD pathogenesis, which have previously been only loosely related.

The purpose of our study is to understand the role of the RALBP1 gene in oxidative stress (OS), mitochondrial dysfunction and cognition in Alzheimer’s disease (AD) pathogenesis. The RALPB1 gene encodes the 76 kDa protein RLIP76 (Rlip). Rlip functions as a stress-responsive/protective transporter of glutathione conjugates (GS-E) and xenobiotic toxins. We hypothesized that Rlip may play an important role in maintaining cognitive function. The aim of this study is to determine whether Rlip deficiency in mice is associated with AD-like cognitive and mitochondrial dysfunction. Brain tissue obtained from cohorts of wildtype (WT) and Rlip^+/− mice were analyzed for OS markers, expression of genes that regulate mitochondrial fission/fusion, and synaptic integrity. We also examined mitochondrial ultrastructure in brains obtained from these mice and further analyzed the impact of Rlip deficiency on gene networks of AD, aging, stress response, mitochondrial function, and CREB signaling. Our studies revealed a significant increase in the levels of OS markers and alterations in the expression of genes and proteins involved in mitochondrial biogenesis, dynamics and synapses in brain tissues from these mice. Furthermore, we compared the cognitive function of WT and Rlip^+/− mice. Behavioral, basic motor and sensory function tests in Rlip^+/− mice revealed cognitive decline, similar to AD. Gene network analysis indicated dysregulation of stress-activated gene expression, mitochondrial function and CREB signaling genes in the Rlip^+/− mouse brain. Our results suggest that Rlip deficiency-associated increases in OS and mitochondrial dysfunction could contribute to the development or progression of OS-related AD processes.

Dietary factors modulate interactions between the microbiome, metabolome, and immune system. Sulforaphane (SFN) exerts effects on aging, cancer prevention and reducing insulin resistance. This study investigated effects of SFN on the gut microbiome and metabolome in old mouse model compared with young mice. Young (6–8 weeks) and old (21–22 months) male C57BL/6J mice were provided regular rodent chow ± SFN for 2 months. We collected fecal samples before and after SFN administration and profiled the microbiome and metabolome. Multi-omics datasets were analyzed individually and integrated to investigate the relationship between SFN diet, the gut microbiome, and metabolome. The SFN diet restored the gut microbiome in old mice to mimic that in young mice, enriching bacteria known to be associated with an improved intestinal barrier function and the production of anti-inflammatory compounds. The tricarboxylic acid cycle decreased and amino acid metabolism-related pathways increased. Integration of multi-omic datasets revealed SFN diet-induced metabolite biomarkers in old mice associated principally with the genera, Oscillospira, Ruminococcus, and Allobaculum. Collectively, our results support a hypothesis that SFN diet exerts anti-aging effects in part by influencing the gut microbiome and metabolome. Modulating the gut microbiome by SFN may have the potential to promote healthier aging.

Background: A decline in skeletal muscle mass and function known as skeletal muscle sarcopenia is an inevitable consequence of aging. Sarcopenia is a major cause of decreased muscle strength, physical frailty and increased muscle fatigability, contributing significantly to an increased risk of physical disability and functional dependence among the elderly. There remains a significant need for a novel therapy that can improve sarcopenia and related problems in aging. Iron accumulation, especially catalytic iron (labile iron) through increased oxidative stress, could be one of the contributing factors to sarcopenia. Our study aimed to examine the effect of an iron chelator on age‐related sarcopenia in mice. Methods: We investigated the effect of iron chelation (deferiprone, DFP) in sarcopenia, using mice with klotho deficiency ( kl/kl ), an established mouse model for aging. Four weeks old Klotho ^−/− male mice were treated with 25 mg/kg body weight of iron chelator deferiprone in drinking water for 8–14 weeks ( n = 12/group, treated and untreated). At the end of the study, gastrocnemius, quadriceps and bicep muscles were dissected and used for western blot and immunohistochemistry analysis, histopathology and iron staining. Serum total iron, catalytic iron and cytokine ELISAs were performed with established methods. Results: Treatment with DFP significantly reduced loss of muscle mass in gastrocnemius and quadriceps muscles ( p < 0.0001). Total and catalytic iron content of serum and iron in muscles were significantly (both p < 0.0001) lower in the treated animals. The inhibitory factor of myogenesis, the myostatin protein in gastrocnemius muscles ( p = 0.019) and serum ( p = 0.003) were downregulated after 8 weeks of therapy accompanied by an increased in muscle contractile protein myosin heavy chain (~2.9 folds, p = 0.0004). Treatment decreased inflammation (serum IL6 and TNFα) ( p < 0.0001, p = 0.005), respectively, and elevated insulin‐like growth factor levels ( p = 0.472). This was associated with reduced DNA damage and reduced 8‐hydroxy 2 deoxyguanosine in muscle and HO‐1 protein ( p < 0.001, p = 079), respectively. Significant weight loss ( p < 0.001) and decreased water intake ( p = 0.012) were observed in untreated mice compared to treatment group. Kaplan–Meier survival curves show the median life span of treated mice was 108 days as compared to 63 days for untreated mice ( p = 0.0002). Conclusions: In summary, our research findings indicate that deferiprone reduced age‐related sarcopenia in the muscles of Klotho ^−/− mice. Our finding suggests chelation of excess iron could be an effective therapy to counter sarcopenia. However, additional studies are needed to evaluate and determine the efficacy in humans.

Her2-amplified breast cancers resistant to available Her2-targeted therapeutics continue to be a challenge in breast cancer therapy. Dox is the mainstay of chemotherapy of all types of breast cancer, but its usefulness is limited by cumulative cardiotoxicity. Because oxidative stress caused by dox generates the pro-apoptotic Ω-6 PUFA metabolite 4-hydroxynonenal (4-HNE), we surmised that Ω-6 PUFAs would increase the effectiveness of dox chemotherapy. Since the mercapturic acid pathway enzyme RALBP1 (also known as RLIP76 or Rlip) that limits cellular accumulation of 4-HNE also mediates dox resistance, the combination of Ω-6 PUFAs and Rlip depletion could synergistically improve the efficacy of dox. Thus, we studied the effects of the Ω-6 PUFA arachidonic acid (AA) and Rlip knockdown on the antineoplastic activity of dox towards Her2-amplified breast cancer cell lines SK-BR-3, which is sensitive to Her2 inhibitors, and AU565, which is resistant. AA increased lipid peroxidation, 4-HNE generation, apoptosis, cellular dox concentration and dox cytotoxicity in both cell lines while sparing cultured immortalized cardiomyocyte cells. The known functions of Rlip including clathrin-dependent endocytosis and dox efflux were inhibited by AA. Our results support a model in which 4-HNE generated by AA overwhelms the capacity of Rlip to defend against apoptosis caused by dox or 4-HNE. We propose that Ω-6 PUFA supplementation could improve the efficacy of dox or Rlip inhibitors for treating Her2-amplified breast cancer.

The purpose of our study is to determine DDQ (diethyl (3,4-dihydroxyphenethylamino) (quinolin-4-yl) methylphosphonate)—a newly discovered molecule that has been shown to protect against phosphorylated tau (p-tau) in Alzheimer’s disease (AD) pathogenesis. We used a well-studied tau (P301L) transgenic mouse model to achieve our goal. We administered DDQ into 12-month-old Tau mice, at 20 mg/kg body weight intraperitoneally two times per week for 2 months. We also assessed DDQ levels in the blood, skeletal muscle and brain using biochemical and molecular techniques. We investigated the mRNA and protein levels of mitochondrial dynamics, biogenesis, synaptic, p-tau and longevity genes sirtuins in DDQ-treated tau mice using real-time quantitative PCR (q-RT-PCR), immunoblotting and immunofluorescence techniques. Our extensive pharmacodynamics investigations revealed that skeletal muscle had the greatest peak levels of DDQ, followed by serum and brain. Interestingly, DDQ-treated tau mice had higher levels of mitochondrial fusion, biogenesis, synaptic genes and sirtuins than DDQ-untreated tau mice. In addition, DDQ-treated tau mice had lower levels of mitochondrial fission and p-tau than untreated tau mice. The current findings, combined with our prior findings, firmly show that DDQ possesses anti-aging, anti-amyloid-beta and anti-p-tau properties, making it a promising molecule for reducing age-related, amyloid-beta and p-tau-induced synaptic and mitochondrial toxicities in AD.