Carbonic anhydrase inhibition ameliorates tau toxicity via enhanced tau secretion.

Tauopathies are neurodegenerative diseases that manifest with intracellular accumulation and aggregation of tau protein. These include Pick's disease, progressive supranuclear palsy, corticobasal degeneration and argyrophilic grain disease, where tau is believed to be the primary disease driver, as well as secondary tauopathies, such as Alzheimer's disease. There is a need to develop effective pharmacological therapies. Here we tested >1,400 clinically approved compounds using transgenic zebrafish tauopathy models. This revealed that carbonic anhydrase (CA) inhibitors protected against tau toxicity. CRISPR experiments confirmed that CA depletion mimicked the effects of these drugs. CA inhibition promoted faster clearance of human tau by promoting lysosomal exocytosis. Importantly, methazolamide, a CA inhibitor used in the clinic, also reduced total and phosphorylated tau levels, increased neuronal survival and ameliorated neurodegeneration in mouse tauopathy models at concentrations similar to those seen in people. These data underscore the feasibility of in vivo drug screens using zebrafish models and suggest serious consideration of CA inhibitors for treating tauopathies.

Aspirin 162 mg vs 81 mg for preeclampsia prophylaxis in high-risk obese individuals: a comparative effectiveness open-label randomized trial (ASPREO).

BACKGROUND: In the United States, leading medical societies recommend 81 mg of aspirin daily for the prevention of preeclampsia in women at risk, whereas the NICE guidelines in the United Kingdom recommend a dose as high as 150 mg of aspirin. Recent data also suggest that in the obese population, inadequate dosing or aspirin resistance may impact the efficacy of aspirin at the currently recommended doses. OBJECTIVE: We evaluated whether daily administration of 162 mg aspirin would be more effective compared with 81 mg in decreasing the rate of preeclampsia with severe features in high-risk obese pregnant individuals. STUDY DESIGN: We performed a randomized trial between May 2019 and November 2022. Individuals at 12-20 weeks of gestational age with a body mass index ≥30 kg/m2 at the time of enrollment and at least 1 of 3 high-risk factors: history of preeclampsia in a prior pregnancy, at least stage I hypertension documented in the index pregnancy, pregestational diabetes or gestational diabetes diagnosed before 20 weeks of gestational age were randomized to either 162 mg or 81 mg of aspirin daily till delivery, participants were not blinded to treatment allocation. Exclusion criteria were multifetal gestation, known major fetal anomalies, seizure disorder, baseline proteinuria, on aspirin because of other indications, or contraindication to aspirin. The primary outcome was preeclampsia with severe features (preeclampsia or superimposed preeclampsia with severe features; eclampsia; or hemolysis, elevated liver enzymes, low platelet count syndrome). Secondary outcomes included rates of preterm birth because of preeclampsia, small for gestational age, postpartum hemorrhage, abruption, and medication side effects. A sample size of 220 was needed using a preplanned Bayesian analysis of the primary outcome to estimate the posterior probability of benefit or harm with a neutral informative prior. RESULTS: Approximately 220/343 (64.1%) individuals were randomized. The primary outcome was available for 209/220 (95%) individuals. Baseline characteristics were similar between groups, with the median gestational age at enrollment being 15.9 weeks in the 162 mg aspirin group and 15.6 weeks in the 81 mg aspirin group. Enrollment before 16 weeks occurred in 55 of 110 of those assigned to 162 mg and 58 of 110 of those assigned to 81 mg of aspirin. The primary outcome occurred in n of d individuals (35%) in the 162 mg aspirin group and n of d individuals (40%) in the 81 mg aspirin group (posterior relative risk, 0.88; 95% credible interval, 0.64-1.22). Bayesian analysis indicated a 78% probability of a reduction in the primary outcome with 162 mg aspirin compared with 81 mg aspirin dose. Rates of indicated preterm birth because of preeclampsia (21% vs 21%), small for gestational age (6.5% vs 2.9%), abruption (2.8% vs 3.0%), and postpartum hemorrhage (10.0% vs 8.8%) were similar between groups. Medication adverse effects were also similar. CONCLUSION: Among high-risk obese individuals, there was a 78% probability of benefit that 162 mg aspirin compared with 81 mg will decrease the rate of preeclampsia with severe features. With the best estimate of a 12% reduction when using 162 mg of aspirin compared with 81 mg of aspirin in this population. This trial supports doing a larger multicenter trial.

Evaluation of fetal growth and birth weight in pregnancies with placenta previa with and without placenta accreta spectrum.

OBJECTIVES: We evaluated fetal growth and birthweight in pregnancies with placenta previa with and without placenta accreta spectrum (PAS). METHODS: We retrospectively studied pregnant patients with placenta previa with or without PAS diagnosed at 20-37 weeks' gestation. Estimated fetal weight (EFW) percentile and fetal growth rate were calculated based on ultrasound at two timepoints: 20-24 and 30-34-weeks' gestation. Fetuses were small (SGA) or large for gestational age (LGA) when EFW or abdominal circumference was <10th or >90th percentile for gestational age, respectively. Fetal growth rate was estimated by subtracting EFW percentiles from the two ultrasounds. Birthweight in grams and percentiles were estimated via Anderson and INTERGROWTH-21 standards adjusted for neonatal sex. EFW percentiles, fetal growth rate, birth weight and birthweight percentiles were compared between patients with placenta previa with and without PAS. RESULTS: We studied 171 patients with and 146 patients without PAS. SGA rates did not differ between groups on first (PAS n=3, no-PAS n=3, p=0.8) or second ultrasound (PAS n=10, no-PAS n=8, p=0.8). LGA rates were similar between groups on first (PAS n=11, no-PAS n=9, p=0.8) and second ultrasound (PAS n=20, no-PAS n=12, p=0.6). The growth rate was higher in fetuses with PAS than placenta previa (1.22 ± 22.3 vs. -4.1 ± 18.1, p=0.07), but not significantly. The birthweight percentile was higher in the PAS than the placenta previa group (74 vs. 67, p=0.01). On multi-linear regression, birthweight percentile remained higher in the PAS group, but not significantly. CONCLUSIONS: Placenta previa with or without PAS is not associated with SGA, LGA or lower birthweight.

Significance of Statin-Associated Muscle Symptoms and Its Impact on Patients Adherence and Outcomes.

ABSTRACT: Statin-associated muscle symptoms (SAMS) are one of the most common side effects of statins. This study aimed to explore the significance of SAMS among statin users by comparing statin users with a control group. To achieve our aims, a propensity score matching the retrospective cohort study was conducted in a single center tertiary hospital. The statin muscle symptoms were assessed using the Proposed Statin Myalgia Index Score, whereas the patient's adherence to medications was evaluated using the Morisky Medication Adherence Scale-8. We included 743 patients in our study; of them, 64.9% were on statin, whereas the rest were controls (35.1%). After propensity score matching, patients on statin had significantly higher rates of SAMS (5.0%) compared with control (1.6%) (AOR = 3.209; 95% CI: 1.020-10.091). However, there was no significant difference between statin users and controls in medications nonadherence ( P -value = 0.820). Our analysis among statins users revealed that moderate-intensity (2.671; 95% CI: 1.691-3.310) and high-intensity (3.552; 95% CI: 2.190-4.129) statin therapy was significantly associated with SAMS. In addition, autoimmune diseases were significantly associated with SAMS occurrence (AOR = 32.301; 95% CI: 1.785-584.374). Also, patients on PPIs had significantly less occurrence of SAMS (AOR = 0.145; 95% CI: 0.044-0.483), whereas patients on antiepileptic drugs had significantly higher SAMS occurrence (AOR = 72.337; 95% CI: 2.649-1975.201). Regarding MACE among statin users, there was no significant difference in the 1-year or 5-year MACE rate between statin users and controls. Our study suggests that SAMS are significant among statin users and must be addressed by health care providers to ensure that patients are still adherent to their medications and hence protected against cardiac events.

Endovascular Treatment plus Medical Treatment versus Medical Treatment Alone in Ischemic Stroke: A Systematic Review and Meta-Analysis.

INTRODUCTION: This study was conducted to assess the hypothesis that endovascular treatment in addition to medical treatment improve stroke mortality and post-stroke disability. METHODS: In this systematic review and meta-analysis, the studies were included if they were randomized controlled trials in design and compared between endovascular treatment and medical therapy versus medical therapy alone in stroke management. RESULTS: The search yielded 22 articles that included 5,049 patients. The analysis showed significant association between the intervention and reduction in disability measured by Modified Rankin Scale (mRS) (mRS = 0-2) (odds ratio [OR] = 1.61; 95% confidence intervals [95% CI]: 1.27-2.06) and National Institute of Health Stroke Scale (NIHSS) (NIHSS = 0-15) (OR = 2.13; 95% CI: 1.04-4.34). Also, we found a significant difference in disability scores between the intervention and the medical therapy group (mRS weighted mean difference [WMD] = -0.59; 95% CI: -1.15 to -0.02, NIHSS WMD = -4.52; 95% CI: -6.32 to -2.72). Additionally, there was significant reduction in mortality in the intervention group (OR = 0.79; 95% CI: 0.68-0.92). There was no significant difference in the rate of any serious adverse effects between the two study groups except for asymptomatic intracerebral hemorrhage. CONCLUSION: Our study provides strong evidence stemmed from randomized clinical trials that endovascular treatment combined with medical therapy is superior to medical therapy alone in the management of stroke.

COVID-19 vaccine safety and side effects in children aged 5-11 years: a cross-sectional study.

INTRODUCTION: The COVID-19 pandemic has prompted a global drive for vaccination, including children. Despite the urgency, understanding the safety and side effects remains crucial. Our study aimed to evaluate the safety of the Pfizer- BioNTech (BNT162b2) vaccine in children by determining the proportion of vaccinated children who experienced side effects and identifying factors associated with postvaccination side effects. MATERIALS AND METHODS: A cross-sectional study was conducted among children who received the COVID-19 vaccine between 3 February and 8 May 2022. Data were collected using a self-administered questionnaire filled out by the parent or legal guardian. RESULTS: The mean age of the study participants was 9 years old and 43.1% were males. Out of the 195 participants in the study, 62 (31.8%) reported side effects after vaccination. The most frequently reported side effects were pain at the injection site (29.7%, n=58), fever (15.9%, n=31), localised inflammation (10.8%, n=21) and arthralgia/myalgia (9.2%, n=18). There were no reported severe adverse events such as anaphylaxis or myocarditis. Most side effects occurred within the first two days post-vaccination. There was a higher proportion of side effects among children with underlying co-morbidities. No significant differences were observed based on age, weight, ethnicity and the presence of allergies, or the use of premedication. CONCLUSION: The BNT162b2 vaccine was generally welltolerated in children, with most side effects being mild and self-limiting. These findings support the safety of the COVID-19 vaccine and would guide healthcare professionals, parents and policy-makers in making informed decisions about COVID-19 vaccination, especially among high-risk groups.

Apoptotic susceptibility of pancreatic alpha cells to environmentally relevant dose levels of bisphenol-A versus dibutyl phthalate is mediated by HSP60/caspase-3 expression in male albino rats.

Unfortunately, humanity is exposed to mixed plasticizers such as bisphenol-A (BPA) and dibutyl phthalate (DBP) that are leached from the daily used plastic products. Previous studies have demonstrated their potential in pancreatic beta cell injury and diabetes induction. The study hypothesized that both compounds would affect the pancreatic alpha cells in albino rats when administered at environmentally relevant doses. Heat shock protein 60 (HSP60) and caspase-3 protein expression was also investigated as potential mechanisms. Thirty-six male Wistar albino rats were separated into four equal groups: control, BPA alone, DBP alone, and BPA + DBP combined groups. BPA and DBP were given in drinking water for 45 days in a dose of 4.5 and 0.8 µg/L, respectively. Fasting blood glucose, serum insulin, pancreatic tissue levels of malondialdehyde, and superoxide dismutase were measured. Pancreatic sections were subjected to hematoxylin & eosin (H & E) staining, glucagon, HSP60, and caspase-3 immunohistochemistry. Although all three experimental groups showed diffuse islet cell HSP60 immunoreactivity, rats exposed to BPA alone showed α-cell-only apoptosis, indicated by H & E changes and caspase-3 immunoreactivity, associated with reduced glucagon immunoreaction. However, rats exposed to DBP alone showed no changes in either α or ß-cells. Both combined-exposed animals displayed α and ß apoptotic changes associated with islet atrophy and reduced glucagon expression. In conclusion, the study suggested HSP60/caspase-3 interaction, caspase-3 activation, and initiation of apoptosis in α-cell only for BPA-alone exposure group, meanwhile DBP alone did not progress to apoptosis. Interestingly, both α/ß cell effect was observed in the mixed group implying synergetic/additive action of both chemicals when combined.

Lrrk promotes tau neurotoxicity through dysregulation of actin and mitochondrial dynamics.

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson disease. Genetics and neuropathology link Parkinson disease with the microtubule-binding protein tau, but the mechanism of action of LRRK2 mutations and the molecular connection between tau and Parkinson disease are unclear. Here, we investigate the interaction of LRRK and tau in Drosophila and mouse models of tauopathy. We find that either increasing or decreasing the level of fly Lrrk enhances tau neurotoxicity, which is further exacerbated by expressing Lrrk with dominantly acting Parkinson disease-associated mutations. At the cellular level, altering Lrrk expression promotes tau neurotoxicity via excess stabilization of filamentous actin (F-actin) and subsequent mislocalization of the critical mitochondrial fission protein dynamin-1-like protein (Drp1). Biochemically, monomeric LRRK2 exhibits actin-severing activity, which is reduced as increasing concentrations of wild-type LRRK2, or expression of mutant forms of LRRK2 promote oligomerization of the protein. Overall, our findings provide a potential mechanistic basis for a dominant negative mechanism in LRRK2-mediated Parkinson disease, suggest a common molecular pathway with other familial forms of Parkinson disease linked to abnormalities of mitochondrial dynamics and quality control, and raise the possibility of new therapeutic approaches to Parkinson disease and related disorders.

Correction to: Enhanced Follicular Delivery of Finasteride to Human Scalp Skin Using Heat and Chemical Penetration Enhancers.

The article Enhanced Follicular Delivery of Finasteride to Human Scalp Skin Using Heat and Chemical Penetration Enhancers, written by Farah, Brown, and McAuley was originally published electronically on the publisher's internet portal on 31 May, 2020 without open access.

Enhanced Follicular Delivery of Finasteride to Human Scalp Skin Using Heat and Chemical Penetration Enhancers.

PURPOSE: The aim of this work was to evaluate whether improved topical delivery of finasteride, focussed to the hair follicles of human scalp skin could be achieved with application of short durations of heat and use of specific chemical penetration enhancers. METHODS: Franz cell experiments with human scalp skin were performed with a range of chemical penetration enhancers at 32°C and 45°C to simulate normal and heated conditions. Selected chemical penetration enhancers were taken forward for finite dose Franz cell studies which examined the effect of heat produced by a prototype external heating system that supplied either 20 or 30 min of additional heat over both a 24 h and a 1 h time period. RESULTS: Short durations of externally applied heat significantly increased finasteride penetration into human scalp skin after 24 h. Analysis of drug distribution in the skin after 1 h and 24 h indicated that both heat and chemical penetration enhancer selection influenced drug delivery to the hair follicles. CONCLUSION: The use of short durations of heat in combination with specific chemical penetration enhancers was able to increase the delivery of finasteride to human scalp skin and provide focussed drug delivery to the hair follicles.

Prevalence and Risk Factors for New-Onset Hypertension in Labor.

OBJECTIVE: Little is known about prevalence, risk factors, rate of treatment, or adverse outcomes associated with intrapartum hypertension. Thus, our objective was to describe these findings. STUDY DESIGN: This was a retrospective study of laboring term gestations with no history of hypertensive disorders. Intrapartum blood pressures were reviewed, and women were subdivided based on blood pressures: normal (<140 mm Hg systolic and <90 mm Hg diastolic), mild hypertension (140-159 or 90-109), and severe hypertension (≥ 160 or ≥ 110). Groups were compared using chi-square test and analysis of variance. RESULTS: A total of 724 women were studied during 4 months: 248 (34%) had mild and 69 (10%) had severe hypertension. Severe hypertensives were more likely to be nulliparous, obese, or have received an epidural or oxytocin. There were no cases of eclampsia, stroke, or pulmonary edema in severe hypertensives (95% confidence interval, 0-5). Despite severely elevated pressures, only 4/69 (6%) patients received intravenous antihypertensive therapy, and 3 (4%) required medications at discharge. CONCLUSION: One in 3 women exhibits mild hypertension and 1 in 10 develop severe hypertension in labor. Only 6% of patients received treatment for severe blood pressures. This study highlights lack of treatment of hypertension in labor and further investigation into causes and outcomes of intrapartum elevations of blood pressures.

A Conserved Cytoskeletal Signaling Cascade Mediates Neurotoxicity of FTDP-17 Tau Mutations In Vivo.

The microtubule binding protein tau is strongly implicated in multiple neurodegenerative disorders, including frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), which is caused by mutations in tau. In vitro, FTDP-17 mutant versions of tau can reduce microtubule binding and increase the aggregation of tau, but the mechanism by which these mutations promote disease in vivo is not clear. Here we take a combined biochemical and in vivo modeling approach to define functional properties of tau driving neurotoxicity in vivo We express wild-type human tau and five FTDP-17 mutant forms of tau in Drosophila using a site-directed insertion strategy to ensure equivalent levels of expression. We then analyze multiple markers of neurodegeneration and neurotoxicity in transgenic animals, including analysis of both males and females. We find that FTDP-17 mutations act to enhance phosphorylation of tau and thus promote neurotoxicity in an in vivo setting. Further, we demonstrate that phosphorylation-dependent excess stabilization of the actin cytoskeleton is a key phosphorylation-dependent mediator of the toxicity of wild-type tau and of all the FTDP-17 mutants tested. Finally, we show that important downstream pathways, including autophagy and the unfolded protein response, are coregulated with neurotoxicity and actin cytoskeletal stabilization in brains of flies expressing wild-type human and various FTDP-17 tau mutants, supporting a conserved mechanism of neurotoxicity of wild-type tau and FTDP-17 mutant tau in disease pathogenesis.SIGNIFICANCE STATEMENT The microtubule protein tau aggregates and forms insoluble inclusion bodies known as neurofibrillary tangles in the brain tissue of patients with a variety of neurodegenerative disorders, including Alzheimer's disease. The tau protein is thus widely felt to play a key role in promoting neurodegeneration. However, precisely how tau becomes toxic is unclear. Here we capitalize on an "experiment of nature" in which rare missense mutations in tau cause familial neurodegeneration and neurofibrillary tangle formation. By comparing the biochemical activities of different tau mutations with their in vivo toxicity in a well controlled Drosophila model system, we find that all mutations tested increase phosphorylation of tau and trigger a cascade of neurotoxicity critically impinging on the integrity of the actin cytoskeleton.

Heat Enhanced Follicular Delivery of Isotretinoin to the Skin.

PURPOSE: The aim of this work was to evaluate the use of short durations of externally applied heat with chemical penetration enhancers to improve delivery of isotretinoin to the skin and in particular via the follicular route. METHODS: A range of chemical penetration enhancers were screened for their ability to improve isotretinoin delivery into human skin with heat using infinite dose, Franz cell experiments conducted in a water bath at a higher temperature to simulate heated conditions. Following this a prototype external heating system was developed that provided short durations of heat and its ability to improve delivery of finite doses into the skin and hair follicles was assessed. RESULTS: The magnitude of the effect of heat on drug delivery was influenced by the choice of vehicle with changes in isotretinoin flux across skin ranging from not statistically significant to 25 fold increases with heat in the infinite dose studies. The prototype heating system provided significant increases in the total delivery of isotretinoin into the skin from an optimised vehicle. Drug distribution in the skin revealed significant increases in isotretinoin delivery to the hair follicles, and deeper skin layers, but not to the stratum corneum, providing strong evidence that the enhancement in delivery occurred mainly via the hair follicles. CONCLUSION: These data indicate that the use of short durations of heat combined with chemical penetration enhancers offers a valuable strategy for improving the delivery of drugs such as isotretinoin to the skin via the hair follicles. Graphical Abstract Schematic illustration of the sodium thiosulphate heating system on a Franz diffusion cell and the subsequent impact of a short burst of heat on the delivery of isotretinoin into human skin.

Adherence to Consensus Guidelines for the Management of Labor Arrest Disorders in a Single Academic Tertiary Care Medical Center.

OBJECTIVE: To evaluate the degree of adherence to the new the American College of Obstetricians and Gynecologists/Society for Maternal-Fetal Medicine guidelines in labor arrest management. STUDY DESIGN: A retrospective study of term, live, singleton deliveries with intrapartum primary cesarean delivery solely for failed induction of labor or labor arrest. Adherence was defined according to the Safe Prevention of the Primary Cesarean Delivery 2014 criteria. We evaluated adherence and compared maternal and perinatal outcomes, delivery time frame, and billing provider. Multivariable Poisson regression models with robust error variance were used to calculate adjusted relative risk (aRR) and 95% confidence interval (CI). RESULTS: Two-hundred six deliveries met the inclusion criteria; 73% were deemed not adherent to the guidelines. The majority of cases were under the care of nonacademic private practice OB/GYN physicians. The adherence rate was higher in the active phase of labor (45%) than in second stage (17%) and latent phase (14%). There were no differences in perinatal outcomes between the two groups. The adherence to guidelines was higher among academic OB/GYN physicians (aRR, 2.24, 95% CI, 1.49-3.36) and during the weekday-night shift (aRR, 1.81, 95% CI, 1.10-2.98). CONCLUSION: Despite recent guidelines aimed to reduce the primary cesarean delivery rate, most cesarean deliveries performed for labor arrest disorders were not adherent to the guidelines.

Preterm Preeclampsia with Severe Features: Composite Maternal and Neonatal Morbidities Associated with Fetal Growth Restriction.

OBJECTIVE: The objective of this study was to compare adverse pregnancy outcomes between fetuses with estimated fetal weight (EFW) < 10 to > 10% in women with preterm preeclampsia (PE) with severe features. MATERIALS AND METHODS: All women with preterm PE with severe features and nonanomalous singletons with EFW were identified at a tertiary center. Women with oligohydramnios or absent/reversed umbilical Doppler velocimetry were excluded. Using multivariable analysis, we compared the composite maternal and neonatal morbidities (CMM and CNM) between those with appropriate for gestational age (AGA) fetal growth, defined as EFW at 10 to 90th versus those with fetal growth restriction (FGR), defined as EFW < 10th percentile for gestational age (GA). RESULTS: In this study, 165 patients were included; 112 had EFW at 10th to 90th percentile, and 53 had FGR. Of the 53 with FGR, 33 (62%) had EFW at 5 to 9% for GA and 20 (38%) had EFW < fifth percentile for GA. The CMM was significantly higher among women with FGR versus AGA (29 vs. 7%; p < 0.001). The CNM was significantly higher with FGR versus AGA (20 vs. 6%; p = 0.01). CONCLUSION: Women with preterm PE with severe features and FGR, when compared with those with AGA, have significantly higher risk of CMM and CNM.

Liberal versus Indicated Maternal Oxygen Supplementation in Labor: A Before-and-After Trial.

BACKGROUND: Although supplemental oxygen (SO2) is routinely administered to laboring gravidas, benefits and harms are not well studied. OBJECTIVE: This article compares strategies of liberal versus indicated SO2 therapy during labor on cesarean delivery (CD) rate and neonatal outcomes. STUDY DESIGN: A controlled, before-and-after trial of laboring women with term, singleton pregnancies. During an initial 8-week period, maternal SO2 was administered at the discretion of the provider followed by an 8-week period where SO2 was to be given only for protocol indications. RESULTS: Our study included 844 women. There was no difference in number of women receiving SO2 (53% liberal vs. 50% indicated; p = 0.33). For those receiving SO2, there was no difference in SO2 duration (median, 89 minutes [interquartile range, 42-172] vs. 87 minutes [36-152]; p = 0.42). There were no differences in overall CD rate (20% vs. 17%; p = 0.70), CD for nonreassuring fetal status, or use of intrauterine resuscitative measures. There were more 5-minute APGAR < 7 in the indicated group, but no difference in umbilical artery pH < 7.1 or neonatal intensive care unit (NICU) admission. CONCLUSION: Approximately half of women receive SO2 intrapartum regardless of a strategy of liberal or indicated oxygen use. There were no clinically significant differences in outcomes between strategies.

Regulation of mammalian autophagy in physiology and pathophysiology.

(Macro)autophagy is a bulk degradation process that mediates the clearance of long-lived proteins and organelles. Autophagy is initiated by double-membraned structures, which engulf portions of cytoplasm. The resulting autophagosomes ultimately fuse with lysosomes, where their contents are degraded. Although the term autophagy was first used in 1963, the field has witnessed dramatic growth in the last 5 years, partly as a consequence of the discovery of key components of its cellular machinery. In this review we focus on mammalian autophagy, and we give an overview of the understanding of its machinery and the signaling cascades that regulate it. As recent studies have also shown that autophagy is critical in a range of normal human physiological processes, and defective autophagy is associated with diverse diseases, including neurodegeneration, lysosomal storage diseases, cancers, and Crohn's disease, we discuss the roles of autophagy in health and disease, while trying to critically evaluate if the coincidence between autophagy and these conditions is causal or an epiphenomenon. Finally, we consider the possibility of autophagy upregulation as a therapeutic approach for various conditions.

LACK OF AN ASSOCIATION BETWEEN BMI AND TSH IN TREATED HYPOTHYROID PATIENTS AND EUTHYROID CONTROLS.

OBJECTIVE: The standard treatment for primary hypothyroidism is replacement with levothyroxine to achieve a thyroid-stimulating hormone (TSH) level within the normal range, (0.45-4.5 mIU/L), which is known to prevent complications including weight gain. While the normal TSH range includes the 95% confidence intervals, it is not known if there is an association between weight and TSH within this interval in treated hypothyroid patients. METHODS: We conducted a retrospective analysis of patients treated within the Cooper Health System from January 1 to August 31, 2014. A sample of 245 treated hypothyroid patients and 162 euthyroid controls were studied. Data collected included age, sex, race/ethnicity, height, weight, levothyroxine dose, and diabetes and smoking history. RESULTS: Hypothyroid and control groups were similar in height, weight, body mass index (BMI), and the number of patients with diabetes. There were more females, Caucasians, and nonsmokers in the hypothyroid group. The average TSH was slightly higher in the treated hypothyroid patients versus nonhypothyroid controls (median 1.87 vs. 1.55, P<.01). There was no significant relationship between TSH and BMI in the treated hypothyroid patients or the euthyroid controls. CONCLUSION: Since no significant relationship was found between BMI and TSH in treated hypothyroidism, there may be no weight reduction benefit gained by adjusting TSH to the lower end of normal range. Patients should be counseled that properly treated hypothyroidism is unlikely to contribute to weight gain. Other treatments such as nutrition and exercise counseling should be offered instead.

IGF-1 receptor antagonism inhibits autophagy.

Inhibition of the insulin/insulin-like growth factor signalling pathway increases lifespan and protects against neurodegeneration in model organisms, and has been considered as a potential therapeutic target. This pathway is upstream of mTORC1, a negative regulator of autophagy. Thus, we expected autophagy to be activated by insulin-like growth factor-1 (IGF-1) inhibition, which could account for many of its beneficial effects. Paradoxically, we found that IGF-1 inhibition attenuates autophagosome formation. The reduced amount of autophagosomes present in IGF-1R depleted cells can be, at least in part, explained by a reduced formation of autophagosomal precursors at the plasma membrane. In particular, IGF-1R depletion inhibits mTORC2, which, in turn, reduces the activity of protein kinase C (PKCα/ß). This perturbs the actin cytoskeleton dynamics and decreases the rate of clathrin-dependent endocytosis, which impacts autophagosome precursor formation. Finally, with important implications for human diseases, we demonstrate that pharmacological inhibition of the IGF-1R signalling cascade reduces autophagy also in zebrafish and mice models. The novel link we describe here has important consequences for the interpretation of genetic experiments in mammalian systems and for evaluating the potential of targeting the IGF-1R receptor or modulating its signalling through the downstream pathway for therapeutic purposes under clinically relevant conditions, such as neurodegenerative diseases, where autophagy stimulation is considered beneficial.

Disassociation of histone deacetylase-3 from normal huntingtin underlies mutant huntingtin neurotoxicity.

Huntington's disease (HD) is caused by a polyglutamine expansion within the huntingtin (Htt) protein. Both loss of function of normal Htt and gain of a toxic function by the polyglutamine-expanded mutant Htt protein have been proposed to be responsible for HD, although the molecular mechanisms involved are unclear. We show that Htt is a neuroprotective protein in both HD-related and unrelated model systems. Neuroprotection by Htt is mediated by its sequestration of histone deacetylase-3 (HDAC3), a protein known to promote neuronal death. In contrast to the normal Htt, mutant Htt interacts poorly with HDAC3. However, expression of mutant Htt liberates HDAC3 from Htt, thus de-repressing its neurotoxic activity. Indeed, mutant Htt neurotoxicity is inhibited by the knockdown of HDAC3 and markedly reduced in HDAC3-deficient neurons. A reduction in Htt-HDAC3 interaction is also seen in neurons exposed to other apoptotic stimuli and in the striatum of R6/2 HD mice. Our results suggest that the robust interaction between Htt and HDAC3 along with the ability of mutant Htt to disrupt this association while not itself interacting with HDAC3 provides an explanation for both the loss-of-function and gain-of-toxic-function mechanisms proposed for HD. Moreover, our results identify HDAC3 as an essential player in mutant Htt-induced neurodegeneration.