D. Allan Butterfield

• Doctor of Philosophy
• University of Kentucky

The maintenance of cognitive function is essential for quality of life and health outcomes in later years. Cognitive impairment, however, remains an undervalued long-term complication of type 2 diabetes by patients and providers alike. The burden of sustained hyperglycemia includes not only cognitive deficits but also the onset and progression of d...

Brain insulin resistance links the failure of energy metabolism with cognitive decline in both type 2 Diabetes Mellitus (T2D) and Alzheimer's disease (AD), although the molecular changes preceding overt brain insulin resistance remain unexplored. Abnormal biliverdin reductase-A (BVR-A) levels were observed in both T2D and AD and were associated wit...

Proteins are essential molecules that play crucial roles in maintaining cellular homeostasis and carrying out biological functions such as catalyzing biochemical reactions, structural proteins, immune response, etc. However, proteins also are highly susceptible to damage by reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this...

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particular...

Background Brain insulin resistance (bIR) is associated with mitochondrial stress, failure of energy metabolism, synaptic loss and ultimately neurodegeneration both in Alzheimer’s disease (AD) and Type 2‐Diabetes Mellitus (T2DM). Our group previously demonstrated that loss of BVR‐A is an early event triggering bIR in AD. Hence, we tested the hypoth...

Significance: Alzheimer disease (AD) is the most common form of dementia associated with aging. As the large Baby Boomer population ages, risk of developing AD increases significantly, and this portion of the population will increase significantly over the next several decades. Recent advances: Research suggests a delay in age of onset by 5 year...

The cells possess several mechanisms to counteract the over-production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), including enzymes such as superoxide dismutase, catalase and glutathione peroxidase. Moreover, an important sensor involved in the anti-oxidant response is KEAP1-NRF2-ARE signaling complex. Under oxidative str...

Cranial radiation is important for treating both primary brain tumors and brain metastases. A potential delayed side effect of cranial radiation is neurocognitive function decline. Early detection of CNS injury might prevent further neuronal damage. Extracellular vesicles (EVs) have emerged as a potential diagnostic tool because of their unique mem...

The complexity of Down Syndrome (DS) neurodegeneration involves multiple molecular mechanisms, similar to what observed in Alzheimer's disease (AD) brain, including the deposition of beta-amyloid (Aβ) into senile plaques and tau hyperphosphorylation in neurofibrillary tangles. Intriguingly, several trisomic genes in addition to being primarily link...

Introduction: Intellectual disability, accelerated aging, and early-onset Alzheimer-like neurodegeneration are key brain pathological features of Down syndrome (DS). Although growing research aims at the identification of molecular pathways underlying the aging trajectory of DS population, data on infants and adolescents with DS are missing. Meth...

Alzheimer's disease (AD) is the most common form of dementia in the elderly followed by vascular dementia. In addition to clinically diagnosed dementia, cognitive dysfunction has been reported in diabetic patients. Recent studies are now beginning to recognize type 2 diabetes mellitus (T2DM), characterized by chronic hyperglycemia and insulin resis...

Chemotherapy-induced cognitive impairment (CICI) has been observed in a large fraction of cancer survivors. Although many of the chemotherapeutic drugs do not cross the blood–brain barrier, following treatment, the structure and function of the brain are altered and cognitive dysfunction occurs in a significant number of cancer survivors. The means...

Cerium oxide nanoparticles, so-called nanoceria, are engineered nanomaterials prepared by many methods that result in products with varying physicochemical properties and applications. Those used industrially are often calcined, an example is NM-212. Other nanoceria have beneficial pharmaceutical properties and are often prepared by solvothermal sy...

e24051 Background: Chemotherapy-induced cognitive impairment (CICI) is a common side effect of cancer therapy, affecting up to 75% of cancer patients. Oxidative stress is thought to play a key role in CICI and patients who have been treated with chemotherapy have demonstrated biochemical brain changes on magnetic resonance spectroscopy (MRS). Metho...

Alzheimer’s disease (AD) is the most prevalent form of dementia in the elderly population and has worldwide impact. The etiology of the disease is complex and results from the confluence of multiple mechanisms ultimately leading to neuronal loss and cognitive decline. Among risk factors, aging is the most relevant and accounts for several pathogeni...

Parkinson disease (PD) is the second most common age-related neurodegenerative disease in the world, and PD significantly impacts the quality of life, especially as in general people are living longer. Because of the numerous and complex features of sporadic PD that progressively develops, it is difficult to build an ideal animal model for PD resea...

Dysregulation of brain insulin signaling with reduced downstream neuronal survival and plasticity mechanisms are fundamental abnormalities observed in Alzheimer disease (AD). This phenomenon, known as brain insulin resistance, is associated with poor cognitive performance and is driven by the inhibition of IRS1. Since Down syndrome (DS) and AD neur...

Background Alterations of brain insulin signalling are a common pathophysiological mechanism leading to dementia in AD and Type 2‐Diabetes Mellitus (T2DM). These alterations are often associated with mitochondrial stress, failure of energy metabolism, synaptic loss and ultimately neurodegeneration. Studies from our group identified impairment of BV...

Oxidative and nitrosative stress are widely recognized as critical factors in the pathogenesis and progression of Alzheimer disease (AD) and its earlier stage, amnestic mild cognitive impairment (MCI). A major source of free radicals that lead to oxidative and nitrosative damage is mitochondria. This review paper discusses oxidative and nitrosative...

Down syndrome (DS) is the most common genetic cause of intellectual disability that is associated with an increased risk to develop early-onset Alzheimer-like dementia (AD). The brain neuropathological features include alteration of redox homeostasis, mitochondrial deficits, inflammation, accumulation of both amyloid beta-peptide oligomers and seni...

A major challenge in neurobiology is the identification of the mechanisms by which protein misfolding leads to cellular toxicity. Many neurodegenerative disorders, in which aberrant protein conformers aggregate into pathological inclusions, present the chronic activation of the PERK branch of the unfolded protein response. The adaptive effects of t...

Nanoceria (CeO 2 , cerium oxide nanoparticles) is proposed as a therapeutic for multiple disorders. In blood, nanoceria becomes protein-coated, changing its surface properties to yield a different presentation to cells. There is little information on the interaction of nanoceria with blood proteins. The current study is the first to report the prot...

This article aims to alert the medical community and public health authorities to accumulating evidence on health benefits from sun exposure, which suggests that insufficient sun exposure is a significant public health problem. Studies in the past decade indicate that insufficient sun exposure may be responsible for 340,000 deaths in the United Sta...

Prior studies showed nanoparticle clearance was different in C57BL/6 versus BALB/c mice, strains prone to Th1 and Th2 immune responses, respectively. Objective: Assess nanoceria (cerium oxide, CeO2 nanoparticle) uptake time course and organ distribution, cellular and oxidative stress, and bioprocessing as a function of mouse strain. Methods: C57BL/...

Juvenile neuronal ceroid lipofuscinosis (JNCL, aka. juvenile Batten disease or CLN3 disease) is a lysosomal storage disease characterized by progressive blindness, seizures, cognitive and motor failures, and premature death. JNCL is caused by mutations in the Ceroid Lipofuscinosis, Neuronal 3 (CLN3) gene, whose function is unclear. Although traditi...

Brains from persons with Alzheimer disease (AD) and its earlier stage, amnestic mild cognitive impairment (MCI), exhibit high levels of oxidative damage, including that to phospholipids. One type of oxidative damage is lipid peroxidation, the most important index of which is protein-bound 4-hydroxy-2-trans-nonenal (HNE). This highly reactive alkena...

Inheritance of apolipoprotein E4 (APOE4) is a major risk factor for development of Alzheimer's disease (AD). This lipoprotein, in contrast to apoE2, has arginine residues at positions 112 and 158 in place of cysteines in the latter isoform. In apoE3, the Cys at residue 158 is replaced by an arginine residue. This differential amino acid composition...

Dysregulation of insulin signaling pathway with reduced downstream neuronal survival and plasticity mechanisms is a fundamental abnormality observed in Alzheimer's disease (AD) brain. This phenomenon, known as brain insulin resistance, is associated with poor cognitive performance and is driven by the uncoupling of insulin receptor (IR) from its di...

Extracellular vesicles (EVs) generated from redox active anticancer drugs are released into the extracellular environment. These EVs contain oxidized molecules and trigger inflammatory responses by macrophages. Using a mouse model of doxorubicin (DOX)-induced tissue injury, we previously found that the major sources of circulating EVs are from hear...

A decline in mitochondrial function plays a key role in the aging process and increases the incidence of age-related disorders, including Alzheimer disease (AD). Mitochondria—the power station of the organism—can affect several different cellular activities, including abnormal cellular energy generation, response to toxic insults, regulation of met...

Parkinson disease (PD) is the second most common neurodegenerative disease associated with aging. Dopaminergic neuronal degeneration and α-synuclein aggregation are commonly found in PD brain. Oxidative damage and inflammation often are considered as etiological factors of PD, although the detailed mechanisms still remain unknown. Gender and aging...

It is generally accepted that alterations in metabolism are critical for the metastatic process; however, the mechanisms by which the metabolic changes are controlled by the major drivers of the metastatic process remain elusive. Here, we find that S100A4, a major metastasis-promoting protein, alters metabolic plasticity to drive tumor invasion and...

p>It is generally accepted that alterations in metabolism are critical for the metastatic process; however, the mechanisms by which the metabolic changes are controlled by the major drivers of the metastatic process remain elusive. Here, we find that S100A4, a major metastasis-promoting protein, alters metabolic plasticity to drive tumor invasion a...

Impairment of biliverdin reductase-A (BVR-A) is an early event leading to brain insulin resistance in AD. Intranasal insulin (INI) administration is under evaluation as a strategy to alleviate brain insulin resistance; however, the molecular mechanisms underlying INI beneficial effects are still unclear. We show that INI improves insulin signalling...

It is generally accepted that alterations in metabolism are critical for the metastatic process; however, the mechanisms by which these metabolic changes are controlled by the major drivers of the metastatic process remain elusive. Here, we found that S100 calcium-binding protein A4 (S100A4), a major metastasis-promoting protein, confers metabolic...

Increasing evidences support the notion that the impairment of intracellular degradative machinery is responsible for the accumulation of oxidized/misfolded proteins that ultimately results in the deposition of protein aggregates. These events are key pathological aspects of “protein misfolding diseases” including Alzheimer disease (AD). Interestin...

Hyper-active GSK-3β favors Tau phosphorylation during the progression of Alzheimer's disease (AD). Akt is one of the main kinases inhibiting GSK-3β and its activation occurs in response to neurotoxic stimuli including, i.e., oxidative stress. Biliverdin reductase-A (BVR-A) is a scaffold protein favoring the Akt-mediated inhibition of GSK-3β. Reduce...

Alzheimer disease (AD) is a major cause of age-related dementia. We do not fully understand AD aetiology and pathogenesis, but oxidative damage is a key component. The brain mostly uses glucose for energy, but in AD and amnestic mild cognitive impairment glucose metabolism is dramatically decreased, probably owing, at least in part, to oxidative da...

Increasing numbers of cancer patients survive and live longer than five years after therapy, but very often side effects of cancer treatment arise at same time. One of the side effects, chemotherapy-induced cognitive impairment (CICI), also called “chemobrain” or “chemofog” by patients, brings enormous challenges to cancer survivors following succe...

Background Type II diabetes is a vascular risk factor for cognitive impairment and increased risk of dementia. Disruption of the blood–retinal barrier (BRB) and blood–brain barrier (BBB) are hallmarks of subsequent retinal edema and central nervous system dysfunction. However, the mechanisms by which diet or metabolic syndrome induces dysfunction a...

Background: Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberr...

Cancer treatments are developing fast and the number of cancer survivors could arise to 20 million in United State by 2025. However, a large fraction of cancer survivors demonstrate cognitive dysfunction and associated decreased quality of life both shortly, and often long-term, after chemotherapy treatment. The etiologies of chemotherapy induced c...

Alzheimer disease (AD) is a progressive neurodegenerative disorder associated with aging and characterized pathologically by the presence of senile plaques, neurofibrillary tangles, and neurite and synapse loss. Amyloid beta‐peptide (1–42) [Aβ(1–42)], a major component of senile plaques, is neurotoxic and induces oxidative stress in vitro and in vi...

Depending on the published study, from 30 % to 70 % of cancer survivors who had undergone chemotherapy reported cognitive dysfunction, usually manifested as memory impairment, difficulty with reasoning, and problems multi-tasking, consistent with deficits of higher executive functioning. This chemotherapy induced cognitive impairment (CICI), often...

Background: Experimental and pre-clinical evidence suggest that adoptive transfer of regulatory T cells (Tregs) could be an appropriate therapeutic strategy to induce tolerance and improve graft survival in transplanted patients. The University of Kentucky Transplant Service Line is developing a novel Phase I/II clinical trial with ex vivo expande...

Alzheimer's disease (AD) is a progressive form of dementia characterized by increased production of amyloid-β plaques and hyperphosphorylated tau protein, mitochondrial dysfunction, elevated oxidative stress, reduced protein clearance, among other. Several studies showed systemic modifications of immune and inflammatory systems due, in part, to dec...

Background: Microdose lithium is protective against Alzheimer's disease (AD), although the precise mechanisms through which its protective effects are conferred remain unclear. Objective: To further examine the effects during the earliest stages of Aβ pathology, we evaluated whether NP03, a microdose lithium formulation, modulates Aβ-mediated ox...

Alzheimer disease (AD) is the major locus of dementia worldwide. In the USA there are nearly 6 million persons with this disorder, and estimates of 13–20 million AD cases in the next three decades. The molecular bases for AD remain unknown, though processes involving amyloid beta-peptide as small oligomeric forms are gaining attention as known agen...

Chemotherapy-induced cognitive impairment (CICI) is now widely recognized as a real and too common complication of cancer chemotherapy experienced by an ever-growing number of cancer survivors. Previously, we reported that doxorubicin (Dox), a prototypical reactive oxygen species (ROS)-producing anti-cancer drug, results in oxidation of plasma prot...

Brain insulin resistance is associated with an increased Aβ production in AD although the molecular mechanisms underlying this link are still largely unknown. Biliverdin reductase-A (BVR-A) is a unique Ser/Thr/Tyr kinase regulating insulin signalling. Studies from our group, demonstrated that BVR-A impairment is among the earliest events favoring b...

Alzheimer disease (AD) is a neurodegenerative disorder characterized by progressive loss of memory, reasoning and other cognitive functions. Pathologically, patients with AD are characterized by deposition of senile plaques (SPs), formed by β-amyloid (Aβ), and neurofibrillary tangles (NTFs) that consist of aggregated hyperphosphorylated tau protein...

PET scan analysis demonstrated the early reduction of cerebral glucose metabolism in Alzheimer disease (AD) patients that can make neurons vulnerable to damage via the alteration of the hexosamine biosynthetic pathway (HBP). Defective HBP leads to flawed protein O-GlcNAcylation coupled, by a mutual inverse relationship, with increased protein phosp...

Oxidative stress is implicated in the pathogenesis and progression of Alzheimer’s disease (AD) and its earlier stage, amnestic mild cognitive impairment (aMCI). One source of oxidative stress in AD and aMCI brains is that associated with amyloid-β peptide, Aβ1-42 oligomers. Our laboratory first showed in AD elevated oxidative stress occurred in bra...

Oxidative stress, an overproduction of free radicals or a diminution of free radical scavenging ability relative to those of cognitively aged-matched controls, is widely recognized as a critical component of the pathogenesis and progression of Alzheimer’s disease (AD). This recognition arose in significant part from the work in the author’s laborat...

Significant advances in the efficacy of cancer therapy have been accompanied by an escalation in side effects that result from therapy-induced injury to normal tissues. Cardiac injury is a major cause of death in cancer survivors, but biomarkers for it are detectable only after tissue injury has occurred. Extracellular vesicles (EVs) sort out oxidi...

Resistance to platinum-based drugs (i.e., carboplatin) is a major clinical challenge in the current treatment of serous ovarian cancer. The molecular mechanisms underlying resistance are not yet fully clarified. In this study, we investigated whether the differences in redox state (levels of antioxidants and ROS) is correlated with carboplatin resi...

Down syndrome (DS), the most frequent chromosomal abnormality in humans, results from complete or partial trisomy of chromosome 21 (Chr21). Though there is intellectual disability in DS people from birth, at about 40-50 years of age conversion to Alzheimer disease (AD)-like neuropathology and dementia often occurs. The mammalian target of rapamycin...

Purpose: Cardiac injury is a major cause of death in cancer survivors, and biomarkers for it are detectable only after tissue injury has occurred. Extracellular vesicles (EV) remove toxic biomolecules from tissues and can be detected in the blood. Here, we evaluate the potential of using circulating EVs as early diagnostic markers for long-term car...

This study examined the impact of surface functionalization and charge on ceria nanomaterial toxicity to Caenorhabditis elegans. The examined endpoints included mortality, reproduction, protein expression, and protein oxidation profiles. Caenorhabditis elegans were exposed to identical 2-5nm ceria nanomaterial cores which were coated with cationic...

The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase involved in the regulation of protein synthesis and degradation, longevity and cytoskeletal formation. The mTOR pathway represents a key growth and survival pathway involved in several diseases such as cancer, obesity, cardiovascular disease and neurodegenerative diseases...

Down Syndrome (DS) is the most common genetic form of intellectual disability that leads in the majority of cases to development of early-onset Alzheimer-like dementia (AD). The neuropathology of DS has several common features with AD including alteration of redox homeostasis, mitochondrial deficits, and inflammation among others. Interestingly, so...

Doxorubicin (DOX) is a potent chemotherapeutic agent known to cause acute and long-term cognitive impairments in cancer patients. Cognitive function is presumed to be primarily mediated by neuronal circuitry in the frontal cortex (FC) and hippocampus, where glutamate is the primary excitatory neurotransmitter. Mice treated with DOX (25 mg/kg i.p.)...

The PI3K/mTOR signaling cascade is fundamental in T-cell activation and fate decisions. We showed the distinct regulation of PI3K/mTOR in regulatory and effector T-cells and proposed the potential therapeutic benefit of targeting this pathway to control the balance between effector and regulatory T-cell activities. Substantial adverse effects in lo...

This chapter highlights the pivotal role protein carbonylation plays in selective neurodegenerative disorders including Alzheimer disease (AD), Parkinson disease (PD), and amyotrophic lateral sclerosis (ALS). Reactive oxygen species (ROS) levels increase as a function of age and are even higher in age-related neurodegenerative disorders. It has bee...

Thermotherapy, as a method of treating cancer, has recently attracted considerable attention from basic and clinical investigators. A number of studies and clinical trials have shown that thermotherapy can be successfully used as a therapeutic approach for various cancers. However, the effects of temperature on cancer bioenergetics have not been st...

Treatment of advanced hepatocellular carcinoma (HCC) remains a challenge due to the high tumor heterogeneity. In the present study, we aim to evaluate the impact of the β-catenin inhibitor, FH535, alone or in combination with the Ras/Raf/MAPK inhibitor Sorafenib, on the bioenergetics profiles of the HCC cell lines Huh7 and PLC/PRF/5. Single low-dos...

One of the major complaints patients who survive cancer often make is chemotherapy induced cognitive impairment (CICI), which survivors often call “chemo brain.” CICI is a side effect of chemotherapy due to the cytotoxicity and neurotoxicity of anti-cancer drugs causing structural and functional changes in brain, even when drugs that do not cross t...

Generation of free radicals and oxidative stress play important roles in the physiological response to engineered biomaterials and nanoparticles. Critical to developing new materials and understanding this process is the ability to detect changes in oxidative stress and the red/ox status of cells. In this chapter, a comprehensive overview of most c...

Oxidatively modified proteins are characterized by elevations in protein-resident carbonyls or 3-nitrotyrosine, measures of protein oxidation, or protein bound reactive alkenals such as 4-hydroxy-2-nonenal, a measure of lipid peroxidation. Oxidatively modified proteins nearly always have altered structure and function. Redox proteomics is that bran...

Down syndrome (DS), trisomy of chromosome 21, is the most common genetic form of intellectual disability. The neuropathology of DS involves multiple molecular mechanisms, similar to AD, including the deposition of beta-amyloid (Aβ) into senile plaques and tau hyperphosphorylationg in neurofibrillary tangles. Interestingly, many genes encoded by chr...

Extracellular vesicles (EVs) including exosomes, microvesicles and apoptotic bodies are released from most cell types; especially under cellular stress conditions, including oxidative stress. The high abundance of EVs in biological fluids and their unique stability make them a potential biomarker for many diseases. It is well recognized that in add...

Brain insulin resistance (b.i.r.) was proposed as a mechanistic mediator of the cognitive deficits observed in Alzheimer disease (AD). Interestingly, the efficacy of intranasal insulin (I-Ins) administration – which allows to directly transport insulin to the CNS – was proposed as an innovative therapeutic strategy to alleviate cognitive dysfunctio...

Alzheimer disease (AD), a multifactorial neurodegenerative disorder that represents one of the most disabling conditions in the aged population, shares many features in common with systemic insulin resistance diseases, including reduced insulin-stimulated growth and survival signaling, increased oxidative stress, pro-inflammatory cytokine activatio...

Aims Among the putative mechanisms proposed to be common factors in Down Syndrome (DS) and Alzheimer disease (AD) neuropathology, deficits in protein quality control has emerged as a unifying mechanism of neurodegeneration. Considering that disturbance of protein degradative systems are present in DS and that oxidized/misfolded proteins require pol...

Aims: Microglial cells are brain resident macrophages engaged in surveillance and maintained in a constant state of relative inactivity. However, their involvement in autoimmune diseases indicates that in pathological conditions microglia gain an inflammatory phenotype. The mechanisms underlying this change in the microglial phenotype are still un...

Oxidative damage is one of the hallmarks of the aging process. The current study evaluated effects of two proprietary antioxidant-based ingredients, rosemary extract and spearmint extract containing carnosic acid and rosmarinic acid, respectively, on learning and memory in the SAMP8 mouse model of accelerated aging. The two rosemary extracts contai...