Touro University California

Studies in animals have documented that, compared with glucose, dietary fructose induces dyslipidemia and insulin resistance. To assess the relative effects of these dietary sugars during sustained consumption in humans, overweight and obese subjects consumed glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 weeks. Although both groups exhibited similar weight gain during the intervention, visceral adipose volume was significantly increased only in subjects consuming fructose. Fasting plasma triglyceride concentrations increased by approximately 10% during 10 weeks of glucose consumption but not after fructose consumption. In contrast, hepatic de novo lipogenesis (DNL) and the 23-hour postprandial triglyceride AUC were increased specifically during fructose consumption. Similarly, markers of altered lipid metabolism and lipoprotein remodeling, including fasting apoB, LDL, small dense LDL, oxidized LDL, and postprandial concentrations of remnant-like particle-triglyceride and -cholesterol significantly increased during fructose but not glucose consumption. In addition, fasting plasma glucose and insulin levels increased and insulin sensitivity decreased in subjects consuming fructose but not in those consuming glucose. These data suggest that dietary fructose specifically increases DNL, promotes dyslipidemia, decreases insulin sensitivity, and increases visceral adiposity in overweight/obese adults.

BACKGROUND: Inflammation is causally related to atherothrombosis. Treatment with canakinumab, a monoclonal antibody that inhibits inflammation by neutralizing interleukin-1β, resulted in a lower rate of cardiovascular events than placebo in a previous randomized trial. We sought to determine whether an alternative approach to inflammation inhibition with low-dose methotrexate might provide similar benefit. METHODS: We conducted a randomized, double-blind trial of low-dose methotrexate (at a target dose of 15 to 20 mg weekly) or matching placebo in 4786 patients with previous myocardial infarction or multivessel coronary disease who additionally had either type 2 diabetes or the metabolic syndrome. All participants received 1 mg of folate daily. The primary end point at the onset of the trial was a composite of nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Near the conclusion of the trial, but before unblinding, hospitalization for unstable angina that led to urgent revascularization was added to the primary end point. RESULTS: The trial was stopped after a median follow-up of 2.3 years. Methotrexate did not result in lower interleukin-1β, interleukin-6, or C-reactive protein levels than placebo. The final primary end point occurred in 201 patients in the methotrexate group and in 207 in the placebo group (incidence rate, 4.13 vs. 4.31 per 100 person-years; hazard ratio, 0.96; 95% confidence interval [CI], 0.79 to 1.16). The original primary end point occurred in 170 patients in the methotrexate group and in 167 in the placebo group (incidence rate, 3.46 vs. 3.43 per 100 person-years; hazard ratio, 1.01; 95% CI, 0.82 to 1.25). Methotrexate was associated with elevations in liver-enzyme levels, reductions in leukocyte counts and hematocrit levels, and a higher incidence of non-basal-cell skin cancers than placebo. CONCLUSIONS: Among patients with stable atherosclerosis, low-dose methotrexate did not reduce levels of interleukin-1β, interleukin-6, or C-reactive protein and did not result in fewer cardiovascular events than placebo. (Funded by the National Heart, Lung, and Blood Institute; CIRT ClinicalTrials.gov number, NCT01594333.).

Anticholinergic Drug Scale (ADS) scores were previously associated with serum anticholinergic activity (SAA) in a pilot study. To replicate these results, the association between ADS scores and SAA was determined using simple linear regression in subjects from a study of delirium in 201 long-term care facility residents who were not included in the pilot study. Simple and multiple linear regression models were then used to determine whether the ADS could be modified to more effectively predict SAA in all 297 subjects. In the replication analysis, ADS scores were significantly associated with SAA (R2 = .0947, P < .0001). In the modification analysis, each model significantly predicted SAA, including ADS scores (R2 = .0741, P < .0001). The modifications examined did not appear useful in optimizing the ADS. This study replicated findings on the association of the ADS with SAA. Future work will determine whether the ADS is clinically useful for preventing anticholinergic adverse effects.

Partitioning of ATP generation between glycolysis and oxidative phosphorylation is central to cellular bioenergetics but cumbersome to measure. We describe here how rates of ATP generation by each pathway can be calculated from simultaneous measurements of extracellular acidification and oxygen consumption. We update theoretical maximum ATP yields by mitochondria and cells catabolizing different substrates. Mitochondrial P/O ratios (mol of ATP generated per mol of [O] consumed) are 2.73 for oxidation of pyruvate plus malate and 1.64 for oxidation of succinate. Complete oxidation of glucose by cells yields up to 33.45 ATP/glucose with a maximum P/O of 2.79. We introduce novel indices to quantify bioenergetic phenotypes. The glycolytic index reports the proportion of ATP production from glycolysis and identifies cells as primarily glycolytic (glycolytic index > 50%) or primarily oxidative. The Warburg effect is a chronic increase in glycolytic index, quantified by the Warburg index. Additional indices quantify the acute flexibility of ATP supply. The Crabtree index and Pasteur index quantify the responses of oxidative and glycolytic ATP production to alterations in glycolysis and oxidative reactions, respectively; the supply flexibility index quantifies overall flexibility of ATP supply; and the bioenergetic capacity quantifies the maximum rate of total ATP production. We illustrate the determination of these indices using C2C12 myoblasts. Measurement of ATP use revealed no significant preference for glycolytic or oxidative ATP by specific ATP consumers. Overall, we demonstrate how extracellular fluxes quantitatively reflect intracellular ATP turnover and cellular bioenergetics. We provide a simple spreadsheet to calculate glycolytic and oxidative ATP production rates from raw extracellular acidification and respiration data.

Alterations in Ca(2+) homeostasis and accumulation of unfolded proteins in the endoplasmic reticulum (ER) lead to an ER stress response. Prolonged ER stress may lead to cell death. Glucose-regulated protein (GRP) 78 (Bip) is an ER lumen protein whose expression is induced during ER stress. GRP78 is involved in polypeptide translocation across the ER membrane, and also acts as an apoptotic regulator by protecting the host cell against ER stress-induced cell death, although the mechanism by which GRP78 exerts its cytoprotective effect is not understood. The present study was carried out to determine whether one of the mechanisms of cell death inhibition by GRP78 involves inhibition of caspase activation. Our studies indicate that treatment of cells with ER stress inducers causes GRP78 to redistribute from the ER lumen with subpopulations existing in the cytosol and as an ER transmembrane protein. GRP78 inhibits cytochrome c-mediated caspase activation in a cell-free system, and expression of GRP78 blocks both caspase activation and caspase-mediated cell death. GRP78 forms a complex with caspase-7 and -12 and prevents release of caspase-12 from the ER. Addition of (d)ATP dissociates this complex and may facilitate movement of caspase-12 into the cytoplasm to set in motion the cytosolic component of the ER stress-induced apoptotic cascade. These results define a novel protective role for GRP78 in preventing ER stress-induced cell death.

The endoplasmic reticulum (ER) is the site of assembly of polypeptide chains destined for secretion or routing into various subcellular compartments. It also regulates cellular responses to stress and intracellular Ca(2+) levels. A variety of toxic insults can result in ER stress that ultimately leads to apoptosis. Apoptosis is initiated by the activation of members of the caspase family and serves as a central mechanism in the cell death process. The present study was carried out to determine the role of caspases in triggering ER stress-induced cell death. Treatment of cells with ER stress inducers such as brefeldin-A or thapsigargin induces the expression of caspase-12 protein and also leads to translocation of cytosolic caspase-7 to the ER surface. Caspase-12, like most other members of the caspase family, requires cleavage of the prodomain to activate its proapoptotic form. Caspase-7 associates with caspase-12 and cleaves the prodomain to generate active caspase-12, resulting in increased cell death. We propose that any cellular insult that causes prolonged ER stress may induce apoptosis through caspase-7-mediated caspase-12 activation. The data underscore the involvement of ER and caspases associated with it in the ER stress-induced apoptotic process.

Exposure to the herbicide paraquat (PQ) is associated with an increased risk of idiopathic Parkinson's disease (PD). Therapies based on PQ's presumed mechanisms of action have not, however, yielded effective disease therapies. Cellular senescence is an anticancer mechanism that arrests proliferation of replication-competent cells and results in a pro-inflammatory senescence-associated secretory phenotype (SASP) capable of damaging neighboring tissues. Here, we demonstrate that senescent cell markers are preferentially present within astrocytes in PD brain tissues. Additionally, PQ was found to induce astrocytic senescence and an SASP in vitro and in vivo, and senescent cell depletion in the latter protects against PQ-induced neuropathology. Our data suggest that exposure to certain environmental toxins promotes accumulation of senescent cells in the aging brain, which can contribute to dopaminergic neurodegeneration. Therapies that target senescent cells may constitute a strategy for treatment of sporadic PD, for which environmental exposure is a major risk factor.

Transdermal drug delivery offers a number of advantages including improved patient compliance, sustained release, avoidance of gastric irritation, as well as elimination of pre-systemic first-pass effect. However, only few medications can be delivered through the transdermal route in therapeutic amounts. Microneedles can be used to enhance transdermal drug delivery. In this review, different types of microneedles are described and their methods of fabrication highlighted. Microneedles can be fabricated in different forms: hollow, solid, and dissolving. There are also hydrogel-forming microneedles. A special attention is paid to hydrogel-forming microneedles. These are innovative microneedles which do not contain drugs but imbibe interstitial fluid to form continuous conduits between dermal microcirculation and an attached patch-type reservoir. Several microneedles approved by regulatory authorities for clinical use are also examined. The last part of this review discusses concerns and challenges regarding microneedle use.

Hispanics are the largest minority group in the USA. They contribute to the economy, cultural diversity, and health of the nation. Assessing their health status and health needs is key to inform health policy formulation and program implementation. To this end, we conducted a scoping review of the literature and national statistics on Hispanic health in the USA using a modified social-ecological framework that includes social determinants of health, health disparities, risk factors, and health services, as they shape the leading causes of morbidity and mortality. These social, environmental, and biological forces have modified the epidemiologic profile of Hispanics in the USA, with cancer being the leading cause of mortality, followed by cardiovascular diseases and unintentional injuries. Implementation of the Affordable Care Act has resulted in improved access to health services for Hispanics, but challenges remain due to limited cultural sensitivity, health literacy, and a shortage of Hispanic health care providers. Acculturation barriers and underinsured or uninsured status remain as major obstacles to health care access. Advantageous health outcomes from the "Hispanic Mortality Paradox" and the "Latina Birth Outcomes Paradox" persist, but health gains may be offset in the future by increasing rates of obesity and diabetes. Recommendations focus on the adoption of the Health in All Policies framework, expanding access to health care, developing cultural sensitivity in the health care workforce, and generating and disseminating research findings on Hispanic health.

Ferroptosis is a newly defined form of regulated cell death characterized by the iron-dependent accumulation of lipid hydroperoxides. Erastin, the ferroptosis activator, binds to voltage-dependent anion channels VDAC2 and VDCA3, but treatment with erastin can result in the degradation of the channels. Here, the authors show that Nedd4 is induced following erastin treatment, which leads to the ubiquitination and subsequent degradation of the channels. Depletion of Nedd4 limits the protein degradation of VDAC2/3, which increases the sensitivity of cancer cells to erastin. By understanding the molecular mechanism of erastin-induced cellular resistance, we can discover how cells adapt to new molecules to maintain homeostasis. Furthermore, erastin-induced resistance mediated by FOXM1-Nedd4-VDAC2/3 negative feedback loop provides an initial framework for creating avenues to overcome the drug resistance of ferroptosis activators.

AIMS: Carnitine and choline are major nutrient precursors for gut microbiota-dependent generation of the atherogenic metabolite, trimethylamine N-oxide (TMAO). We performed randomized-controlled dietary intervention studies to explore the impact of chronic dietary patterns on TMAO levels, metabolism and renal excretion. METHODS AND RESULTS: Volunteers (N = 113) were enrolled in a randomized 2-arm (high- or low-saturated fat) crossover design study. Within each arm, three 4-week isocaloric diets (with washout period between each) were evaluated (all meals prepared in metabolic kitchen with 25% calories from protein) to examine the effects of red meat, white meat, or non-meat protein on TMAO metabolism. Trimethylamine N-oxide and other trimethylamine (TMA) related metabolites were quantified at the end of each diet period. A random subset (N = 13) of subjects also participated in heavy isotope tracer studies. Chronic red meat, but not white meat or non-meat ingestion, increased plasma and urine TMAO (each >two-fold; P < 0.0001). Red meat ingestion also significantly reduced fractional renal excretion of TMAO (P < 0.05), but conversely, increased fractional renal excretion of carnitine, and two alternative gut microbiota-generated metabolites of carnitine, γ-butyrobetaine, and crotonobetaine (P < 0.05). Oral isotope challenge revealed red meat or white meat (vs. non-meat) increased TMA and TMAO production from carnitine (P < 0.05 each) but not choline. Dietary-saturated fat failed to impact TMAO or its metabolites. CONCLUSION: Chronic dietary red meat increases systemic TMAO levels through: (i) enhanced dietary precursors; (ii) increased microbial TMA/TMAO production from carnitine, but not choline; and (iii) reduced renal TMAO excretion. Discontinuation of dietary red meat reduces plasma TMAO within 4 weeks.

CONTEXT: The definition of what constitutes a normal TSH during pregnancy is in flux. Recent studies suggested that the first trimester upper limit of normal for TSH should be 2.5 mIU/liter. OBJECTIVE: The objective of the study was to evaluate the pregnancy loss and preterm delivery rate in first-trimester thyroid peroxidase antibody-negative women with TSH values between 2.5 and 5.0 mIU/liter. DESIGN: The present study is a component of a recently published large-scale prospective trial that evaluated the impact of levothyroxine treatment on maternal and neonatal complications in thyroid peroxidase-positive women with TSH levels above 2.5 mIU/liter. The present study evaluated 4123 thyroid peroxidase antibody-negative women with TSH levels at or below 5.0 mIU/liter. Women were divided into two groups based on their initial TSH: group A, TSH level below 2.5 mIU/liter, excluding hyperthyroid women defined as an undetectable TSH with an elevated free T(4), and group B, TSH level between 2.5 and 5.0 mIU/liter. SETTING: The study was conducted at two ambulatory clinics of community hospitals in southern Italy. PATIENTS: A total of 4123 women were evaluated. INTERVENTION: There was no intervention. MAIN OUTCOME MEASURES: The incidence of pregnancy loss and preterm delivery in group A as compared with group B was measured. RESULTS: The rate of pregnancy loss was significantly higher in group B as compared with group A (6.1 vs. 3.6% respectively, P = 0.006). There was no difference in the rate of preterm delivery between the two groups. CONCLUSIONS: The increased incidence of pregnancy loss in pregnant women with TSH levels between 2.5 and 5.0 mIU/liter provides strong physiological evidence to support redefining the TSH upper limit of normal in the first trimester to 2.5 mIU/liter.

High-fructose diet stimulates hepatic de novo lipogenesis (DNL) and causes hypertriglyceridemia and insulin resistance in rodents. Fructose-induced insulin resistance may be secondary to alterations of lipid metabolism. In contrast, fish oil supplementation decreases triglycerides and may improve insulin resistance. Therefore, we studied the effect of high-fructose diet and fish oil on DNL and VLDL triglycerides and their impact on insulin resistance. Seven normal men were studied on four occasions: after fish oil (7.2 g/day) for 28 days; a 6-day high-fructose diet (corresponding to an extra 25% of total calories); fish oil plus high-fructose diet; and control conditions. Following each condition, fasting fractional DNL and endogenous glucose production (EGP) were evaluated using [1-13C]sodium acetate and 6,6-2H2 glucose and a two-step hyperinsulinemic-euglycemic clamp was performed to assess insulin sensitivity. High-fructose diet significantly increased fasting glycemia (7 +/- 2%), triglycerides (79 +/- 22%), fractional DNL (sixfold), and EGP (14 +/- 3%, all P < 0.05). It also impaired insulin-induced suppression of adipose tissue lipolysis and EGP (P < 0.05) but had no effect on whole- body insulin-mediated glucose disposal. Fish oil significantly decreased triglycerides (37%, P < 0.05) after high-fructose diet compared with high-fructose diet without fish oil and tended to reduce DNL but had no other significant effect. In conclusion, high-fructose diet induced dyslipidemia and hepatic and adipose tissue insulin resistance. Fish oil reversed dyslipidemia but not insulin resistance.

Using a modified social ecological model, we conducted a review of the literature and nationwide statistics on African American health. We discuss the main social determinants of health and main health disparities, risk factors, the leading causes of morbidity and mortality, and access to health services for blacks in the USA. The mechanisms through which social determinants, including racism, exert their deleterious effects on black health are discussed at the macro and individual levels. Incarceration and mental health care issues are highlighted as priorities to be addressed. African Americans remain the least healthy ethnic group in the USA, a somber legacy of years of racial and social injustice and a formidable challenge to equitable health care for all. Systemic causes of suboptimal black health require equally systemic solutions; positive trends in black health indicators seem to be driven by social development programs, economic investment in education, participation of African Americans in policy, and decision-making and expansion of access to health care.

The critical role of primary care clinicians (PCCs) in Alzheimer's disease (AD) prevention, diagnosis and management must evolve as new treatment paradigms and disease-modifying therapies (DMTs) emerge. Our understanding of AD has grown substantially: no longer conceptualized as a late-in-life syndrome of cognitive and functional impairments, we now recognize that AD pathology builds silently for decades before cognitive impairment is detectable. Clinically, AD first manifests subtly as mild cognitive impairment (MCI) due to AD before progressing to dementia. Emerging optimism for improved outcomes in AD stems from a focus on preventive interventions in midlife and timely, biomarker-confirmed diagnosis at early signs of cognitive deficits (i.e. MCI due to AD and mild AD dementia). A timely AD diagnosis is particularly important for optimizing patient care and enabling the appropriate use of anticipated DMTs. An accelerating challenge for PCCs and AD specialists will be to respond to innovations in diagnostics and therapy for AD in a system that is not currently well positioned to do so. To overcome these challenges, PCCs and AD specialists must collaborate closely to navigate and optimize dynamically evolving AD care in the face of new opportunities. In the spirit of this collaboration, we summarize here some prominent and influential models that inform our current understanding of AD. We also advocate for timely and accurate (i.e. biomarker-defined) diagnosis of early AD. In doing so, we consider evolving issues related to prevention, detecting emerging cognitive impairment and the role of biomarkers in the clinic.

ABSTRACT Diet can influence the composition of the human microbiome, and yet relatively few dietary ingredients have been systematically investigated with respect to their impact on the functional potential of the microbiome. Dietary resistant starch (RS) has been shown to have health benefits, but we lack a mechanistic understanding of the metabolic processes that occur in the gut during digestion of RS. Here, we collected samples during a dietary crossover study with diets containing large or small amounts of RS. We determined the impact of RS on the gut microbiome and metabolic pathways in the gut, using a combination of “omics” approaches, including 16S rRNA gene sequencing, metaproteomics, and metabolomics. This multiomics approach captured changes in the abundance of specific bacterial species, proteins, and metabolites after a diet high in resistant starch (HRS), providing key insights into the influence of dietary interventions on the gut microbiome. The combined data showed that a high-RS diet caused an increase in the ratio of Firmicutes to Bacteroidetes , including increases in relative abundances of some specific members of the Firmicutes and concurrent increases in enzymatic pathways and metabolites involved in lipid metabolism in the gut. IMPORTANCE This work was undertaken to obtain a mechanistic understanding of the complex interplay between diet and the microorganisms residing in the intestine. Although it is known that gut microbes play a key role in digestion of the food that we consume, the specific contributions of different microorganisms are not well understood. In addition, the metabolic pathways and resultant products of metabolism during digestion are highly complex. To address these knowledge gaps, we used a combination of molecular approaches to determine the identities of the microorganisms in the gut during digestion of dietary starch as well as the metabolic pathways that they carry out. Together, these data provide a more complete picture of the function of the gut microbiome in digestion, including links between an RS diet and lipid metabolism and novel linkages between specific gut microbes and their metabolites and proteins produced in the gut.

BACKGROUND: The aetiology and exact incidence of infantile haemangiomas (IHs) are unknown. Prior studies have noted immunohistochemical and biological characteristics shared by IHs and placental tissue. OBJECTIVES: We investigated the possible association between placental anomalies and the development of IHs, as well as the demographic characteristics and other risk factors for IHs. PATIENTS AND METHODS: Pregnant women (n = 578) were prospectively enrolled and their offspring followed for 9 months. Placental evaluations were performed and demographic data collected on all mother-infant pairs. RESULTS: We evaluated 594 infants: 34 haemangiomas [either IH or congenital (CH)] were identified in 29 infants, yielding an incidence of 4·5% for IH (27 infants) and 0·3% for CH (two infants). Placental anomalies were noted in almost 35% of haemangioma-related pregnancies, approximately twice the incidence noted in pregnancies with unaffected infants (P = 0·025). Other risk factors for IH included prematurity (P = 0·016) and low birth weight (P = 0·028). All IHs were present by 3 months of age, and cessation of growth had occurred in all by 9 months of age. Most occurred on the trunk. Of note, 20% of identified IHs were abortive or telangiectatic in nature, small focal lesions that did not proliferate beyond 3 months of age. Only one IH required intervention. CONCLUSIONS: This is the first prospective American study to document the incidence of IHs in infants followed from birth to early infancy. The association with placental anomalies was statistically significant. The overall incidence mirrors prior estimates, but the need for treatment was lower than previously reported.

INTRODUCTION AND AIMS: As the popularity of electronic cigarettes (e-cigarettes) increases, it is becoming important to find out more about the characteristics of e-cigarette users, why and how they use the product and whether e-cigarettes are used exclusively or in combination with conventional cigarettes. The objective of this study was to investigate patterns and effects of e-cigarette use and user beliefs about e-cigarette safety and benefits. DESIGN AND METHODS: E-cigarette users in Poland were recruited online and asked to participate in a web-based survey. The participants provided information on their smoking history, patterns of e-cigarette use, beliefs and attitudes regarding the product and information on concurrent use of conventional cigarettes. RESULTS: The survey was completed by 179 e-cigarette users. Almost all participants used e-cigarettes daily. E-cigarettes were primarily used to quit smoking or to reduce the harm associated with smoking (both 41%), and were successful in helping the surveyed users to achieve these goals with 66% not smoking conventional cigarettes at all and 25% smoking under five cigarettes a day. Most participants (82%) did not think that e-cigarettes were completely safe, but thought that they were less dangerous than conventional cigarettes. Sixty percent believed that e-cigarettes were addictive, but less so than conventional cigarettes. DISCUSSION AND CONCLUSIONS: The participants primarily used e-cigarettes as a stop-smoking aid or as an alternative to conventional cigarettes, and the majority reported that they successfully stopped smoking. More data on e-cigarette safety and its efficacy in harm-reduction and smoking cessation are needed.

Problem: Rates of walking and bicycling to school have declined sharply in recent decades, and federal and state governments have committed funds to reverse these trends. To increase rates of walking and biking to school will require understanding why many parents choose to drive their children to school and how well existing programs, like Safe Routes to School, work. Purpose: We aimed to understand why many parents choose to drive their children even short distances to school, and what implications this has for programs to increase walking and biking to school. Methods: We used data from a telephone survey to explore why parents drive their children to school. Results and conclusions: We found that 75% of parents driving their children less than 2 miles to school said they did this for convenience and to save time. Nearly half of parents driving their children less than 2 miles did not allow their child to walk to school without adult supervision. Accompanying a child on a walk to school greatly increases the time the household devotes to such a trip. Few Safe Routes to School programs effectively address issues of parental convenience and time constraints. Takeaway for practice: Safe Routes to School programs should take parental convenience and time constraints into account by providing ways children can walk to school supervised by someone other than the parent, such as by using walking school buses. To be effective, such programs need institutional support. Schools should take a multimodal approach to pupil transportation. Research support: This research was funded by the Active Living Research program of the Robert Wood Johnson Foundation and the U.S. and California Departments of Transportation through the University of California Transportation Center.

Huntington's disease (HD) is a neurodegenerative disorder caused by a polyglutamine (polyQ) tract expansion near the N terminus of huntingtin (Htt). Proteolytic processing of mutant Htt and abnormal calcium signaling may play a critical role in disease progression and pathogenesis. Recent work indicates that calpains may participate in the increased and/or altered patterns of Htt proteolysis leading to the selective toxicity observed in HD striatum. Here, we identify two calpain cleavage sites in Htt and show that mutation of these sites renders the polyQ expanded Htt less susceptible to proteolysis and aggregation, resulting in decreased toxicity in an in vitro cell culture model. In addition, we found that calpain- and caspase-derived Htt fragments preferentially accumulate in the nucleus without the requirement of further cleavage into smaller fragments. Calpain family members, calpain-1, -5, -7, and -10, have increased levels or are activated in HD tissue culture and transgenic mouse models, suggesting they may play a key role in Htt proteolysis and disease pathology. Interestingly, calpain-1, -5, -7, and -10 localize to the cytoplasm and the nucleus, whereas the activated forms of calpain-7 and -10 are found only in the nucleus. These results support the role of calpain-derived Htt fragmentation in HD and suggest that aberrant activation of calpains may play a role in HD pathogenesis.