Genetic ablation of acid ceramidase in Krabbe disease confirms the psychosine hypothesis and identifies a new therapeutic target.

Infantile globoid cell leukodystrophy (GLD, Krabbe disease) is a fatal demyelinating disorder caused by a deficiency in the lysosomal enzyme galactosylceramidase (GALC). GALC deficiency leads to the accumulation of the cytotoxic glycolipid, galactosylsphingosine (psychosine). Complementary evidence suggested that psychosine is synthesized via an anabolic pathway. Here, we show instead that psychosine is generated catabolically through the deacylation of galactosylceramide by acid ceramidase (ACDase). This reaction uncouples GALC deficiency from psychosine accumulation, allowing us to test the long-standing "psychosine hypothesis." We demonstrate that genetic loss of ACDase activity (Farber disease) in the GALC-deficient mouse model of human GLD (twitcher) eliminates psychosine accumulation and cures GLD. These data suggest that ACDase could be a target for substrate reduction therapy (SRT) in Krabbe patients. We show that pharmacological inhibition of ACDase activity with carmofur significantly decreases psychosine accumulation in cells from a Krabbe patient and prolongs the life span of the twitcher (Twi) mouse. Previous SRT experiments in the Twi mouse utilized l-cycloserine, which inhibits an enzyme several steps upstream of psychosine synthesis, thus altering the balance of other important lipids. Drugs that directly inhibit ACDase may have a more acceptable safety profile due to their mechanistic proximity to psychosine biogenesis. In total, these data clarify our understanding of psychosine synthesis, confirm the long-held psychosine hypothesis, and provide the impetus to discover safe and effective inhibitors of ACDase to treat Krabbe disease.

Clinical Assessment of Immediate and Long-Term Effects of a Two-Step Topical Hyaluronic Acid Lip Treatment.

Key features of lip aging include loss of volume, color, and definition as well as increases in lines/wrinkles and uneven skin texture. A single-center, open-label clinical study was conducted to assess the efficacy and tolerability of a novel, topical two-step lip treatment (HA5 LS) in female subjects presenting with mild to moderate lip dryness and mild to severe lip condition. Subjects were instructed to apply HA5 LS at least three times a day to ensure coverage 8 hours a day for four weeks. Clinical assessments for efficacy and tolerability were conducted at baseline, baseline post-application, week 2, and week 4. Standardized digital photography, subject self-assessment questionnaires, and instrumentation measurements for skin hydration (corneometer) and lip plumpness (digital caliper) were also conducted. Thirty-six female subjects aged 22-40 years enrolled in the study. HA5 LS provided instant and long term effects, achieving significant improvements in all clinical grading parameters including lip texture, color, definition/contour, scaling, cupping, lines/wrinkles, lip plumpness, and overall lip condition from baseline post-application to week 4 (all P less than equal to .001; Wilcoxon signed-rank test). Instrumentation measurements for hydration and digital caliper at weeks 2 and 4 were also significant (all P less than equal to .032; paired t-test). HA5 LS was also well-tolerated and highly-rated by subjects throughout the study duration. Results from this study suggest that HA5 LS addresses the key features of lip aging, providing both instant and long-term benefits.

J Drugs Dermatol. 2017;16(4):366-371.

A randomized, double-blind, split-face study comparing the efficacy and tolerability of three retinol-based products vs. three tretinoin-based products in subjects with moderate to severe facial photodamage.

Retinol, has been shown to improve the appearance of photodamaged skin when applied topically, and is generally considered to be approximately ten times less potent than tretinoin. To assess this theory, three cosmetic formulations containing 0.25%, 0.5%, and 1.0% retinol were developed to correspond to the three commonly prescribed concentrations of tretinoin (0.025%, 0.05%, and 0.1%). A randomized, double-blind, split-face comparison study was conducted to compare the three concentrations retinol (Ret) including 0.25%, 0.5%, and 1.0%, against the respective three strengths of tretinoin (Tret) 0.025%, 0.05%, and 0.1% in subjects with moderate to severe facial photodamage. Subjects were randomized into three groups: Group 1 (Ret 0.25% vs. Tret 0.025%); Group 2 (Ret 0.5% vs. Tret 0.05%); and Group 3 (Ret 1.0% vs. Tret 0.1%). Within each group, subjects were randomized to apply Ret on one half of the face (left or right) and Tret on the other facial side, for a duration of twelve weeks. Clinical evaluations for efficacy and tolerability, as well as standardized digital photographs were conducted at baseline and at weeks 4, 8, and 12. Sixty-five subjects completed the twelve-week study (Group 1: n=24, Group 2: n=20, and Group 3: n=21). At week 12 in all treatment groups, both Ret and Tret produced statistically significant improvements from baseline in all efficacy parameters, including overall photodamage, fine lines/wrinkles, coarse lines/wrinkles, skin tone brightness, mottled pigmentation, and tactile roughness (all P<0.001). There were no significant differences in efficacy between Ret and Tret in these efficacy parameters. Results from this comparison study suggest that this sustained-release retinol complex containing multiple agents for optimal irritation control provides comparable improvements to tretinoin in the appearance of photodamage.

Steroid-Free Over-the-Counter Eczema Skin Care Formulations Reduce Risk of Flare, Prolong Time to Flare, and Reduce Eczema Symptoms in Pediatric Subjects With Atopic Dermatitis.

INTRODUCTION: Atopic dermatitis (AD) is a chronic skin condition associated with decreased barrier function resulting in periodic flare-ups of erythematous and pruritic lesions. Guidelines recommend daily treatment of atopic skin with emollient moisturizers for prevention of flares and maintenance of the flare-free state. This study evaluated the efficacy of 2 steroid-free, nonprescription eczema skin care formulations for reducing the risk of flare and relieving symptoms in infants and children with AD: Body Cream for the daily maintenance treatment of atopic skin and Flare Treatment for the treatment of atopic flares. METHODS: After a 2-week washout period, subjects (N=45; mean age 3.5 years) were randomized to cleanser plus daily moisturizing with Body Cream (moisturizer group) or cleanser only (control group) for 6 months or until flare. Subjects experiencing flare received Flare Treatment for 4 weeks. RESULTS: The incidence of flare was significantly lower in the moisturizer group compared with the control group (21% vs 65%; P=.006), while the median time to flare was shorter in the control group (28 vs >180 days). Risk of flare was reduced by 44.1% after 6 months of Body Cream application. Flare Treatment reduced overall eczema symptom severity at week 2 and week 4; 78.9% of flares had improved or cleared at week 4. CONCLUSIONS: Body Cream reduced the incidence of flare and the time to flare, reinforcing guidelines that daily emollient therapy should be an integral part of the maintenance treatment plan for the prevention of disease flares. Body Cream and Flare Treatment are effective over-the-counter steroid-free options for management of AD in children.

A case series of real-time hemodynamic assessment of high output heart failure as a complication of arteriovenous access in dialysis patients.

Congestive heart failure (CHF) is an important source of morbidity and mortality in end-stage renal disease patients. Although CHF is commonly associated with low cardiac output (CO), it may also occur in high CO states. Multiple conditions are associated with increased CO including congenital or acquired arteriovenous fistulae or arteriovenous grafts. Increased CO resulting from permanent AV access in dialysis patients has been shown to induce structural and functional cardiac changes, including the development of eccentric left ventricle hypertrophy. Often, the diagnosis of high output heart failure requires invasive right heart monitoring in the acute care setting such as a medical or cardiac intensive care unit. The diagnosis of an arteriovenous access causing high output heart failure is usually confirmed after the access is ligated surgically. We present for the first time, a case for real-time hemodynamic assessment of high output heart failure due to AV access by interventional nephrology in the cardiac catheterization suite.

Steroid-free emollient formulations reduce symptoms of eczema and improve quality of life.

Two over-the-counter products have been clinically tested for efficacy and tolerability in the treatment of atopic dermatitis. Study 1 evaluated a daily maintenance Body Cream (Eucerin Eczema Relief Body Crème) applied twice daily for 14 days, followed by treatment withdrawal for 5 days (regression period) in subjects with a history of atopic dermatitis. Study 2 evaluated an acute treatment (Eucerin Eczema Relief Instant Therapy [Instant Therapy]) for active atopic dermatitis lesions administered for 14 days. Skin barrier function, hydration, tolerability, and relief of symptoms were assessed at baseline, day 7, and day 14. Study 2 also measured itch relief and treatment impact on work, social activities, and sleep. Body Cream significantly improved skin hydration and barrier function (P<.001) at 14 days, with improvements persisting through the 5-day regression phase. Itching was significantly improved in 93.8% of subjects (P<.001). Instant Therapy treatment of atopic dermatitis lesions significantly improved skin hydration and barrier function, as well as symptoms of erythema, pruritus, excoriation, and lichenification, with rapid improvement of itch reported within minutes of the first treatment application. Instant Therapy significantly reduced itch intensity and frequency, and demonstrated beneficial improvements in subjects' quality of life. Body Cream and Instant Therapy were both safe and well tolerated.

Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of Oral AL01211 in Healthy Chinese Volunteers.

BACKGROUND AND OBJECTIVE: Aberrant accumulation of glycosphingolipids (GSLs) in the lysosome leads to GSL storage diseases. Glucosylceramide synthase inhibitors (GCSi) have the potential to treat several GSL storage diseases by reducing the synthesis of the disease-causing GSLs. AL01211 is a potent oral GCSi under investigation for Type 1 Gaucher disease and Fabry disease. Here, we evaluate the pharmacokinetics, pharmacodynamics, safety, and tolerability of AL01211 in healthy Chinese volunteers. METHODS: AL01211 was tested in a Phase 1, single-center, randomized, double-blind, placebo-controlled study with single-dose (15 and 60 mg) and multiple-dose (30 mg) arms. RESULTS: Results of AL01211 demonstrated dose-dependent pharmacokinetics, rapid absorption (median time to maximum plasma concentration [tmax] 2.5-4 hours), relatively slow clearance rate (mean apparent total clearance from plasma [CL/F] 88.3-200 L/h) and the mean terminal half-life above 30 hours. Repeated once-daily oral administration of AL01211 for 14 days had an approximately 2-fold accumulation, reaching steady-state levels between 7 and 10 days, and led to a 73% reduction in plasma glucosylceramide (GL1) on Day 14. AL01211 was safe and well tolerated, with no identified serious adverse events. CONCLUSION: AL01211 showed a favorable pharmacokinetic, pharmacodynamics, safety, and tolerability profile in healthy Chinese volunteers. These data support the further clinical development of AL01211 as a therapy for GSL storage diseases. CLINICAL TRIAL REGISTRY: Clinical Trial Registry no. CTR20221202 ( http://www.chinadrugtrials.org.cn ) registered on 6 June 2022 and ChiCTR2200061431 ( http://www.chictr.org.cn ) registered on 24 June 2022.

Phase 1 Healthy Volunteer Study of AL01211, an Oral, Non-brain Penetrant Glucosylceramide Synthase Inhibitor, to Treat Fabry Disease and Type 1 Gaucher Disease.

Glycosphingolipid (GSL) storage diseases are caused by deficiencies in the enzymes that metabolize different GSLs in the lysosome. Glucosylceramide synthase (GCS) inhibitors reduce GSL production and have potential to treat multiple GSL storage diseases. AL01211 is a potent, oral GCS inhibitor being developed for the treatment of Type 1 Gaucher disease and Fabry disease. AL01211 has minimal central nervous system penetration, allowing for treatment of peripheral organs without risking CNS-associated adverse effects. AL01211 was evaluated in a Phase 1 healthy volunteer study with single ascending dose (SAD) and multiple ascending dose (MAD) arms, to determine safety, pharmacokinetics including food effect, and pharmacodynamic effects on associated GSLs. In the SAD arm, AL01211 showed a Tmax of approximately 3.5 hours, mean clearance (CL/F) of 130.1 L/h, and t1/2 of 39.3 hours. Consuming a high-fat meal prior to dose administration reduced exposures 3.5-5.5-fold, indicating a food effect. In the MAD arm, AL01211 had an approximately 2-fold accumulation, reaching steady-state levels by 10 days. Increasing exposure inversely correlated with a decrease in GSL with plasma glucosylceramide and globotriacylceramide reduction from baseline levels, reaching 78% and 52% by day 14, respectively. AL01211 was generally well-tolerated with no AL01211 associated serious adverse events, thus supporting its further clinical development.

Candidates for transcatheter aortic valve replacement: fitting the PARTNERS criteria.

OBJECTIVES: To determine an estimate patient volume with severe AS meeting PARTNER-B criteria, with the objective of providing insights into the annual volume needed to sustain a TAVR program. BACKGROUND: While the prevalence of AS is well documented, potential TAVR candidates remains less established. A better understanding of this population is critical for the development of TAVR programs. Though no clear volume has been determined, societies suggest a minimum of 20-24 annual cases to establish a TAVR program. METHODS: A total of 21,652 patients were screened from a single center echocardiography registry over a 3-year period. From them, 833 patients with AS were identified representing our study population. Severity was stratified by echocardiographic criteria. Those identified to have moderate-to-severe and severe AS were further investigated to determine clinical status and surgical candidacy. Nonsurgical candidates were cross referenced with the PARTNER-B exclusion criteria to determine eligibility for TAVR. RESULTS: Symptomatic AS was present in 133 patients (16%). Fifty (38%) were considered nonsurgical candidates. Nonsurgical patients had higher STS score (11.1 ± 10.8 vs. 4.0 ± 3.3, P < 0.001). After applying PARTNERS-B exclusion criteria, only 18 patients (14%) were considered TAVR candidates. These findings indicate that to meet the recommended annual volume of 20-24 TAVR cases, a minimum of 150-170 symptomatic severe AS patients are required. CONCLUSION: In real world clinical practice, the prevalence of AS meeting PARTNERS-B criteria for TAVR can be low. These findings suggest that either high volume valvular centers or regional referral centers will need to be considered as part of the strategy to incorporate this new technology into clinical practice.

Project I See in NC: Initial results of a program to increase access to retinal examinations among diabetic individuals in North Carolina.

BACKGROUND: Diabetic retinopathy is the leading cause of preventable blindness in adults. Project I See in NC was begun to determine whether access to eye screening for Medicaid recipients and uninsured patients with diabetes in North Carolina could be improved. METHODS: We targeted Medicaid recipients and uninsured adults with diabetes for screening in 2 Community Care of North Carolina Networks. Screenings were performed in primary care settings throughout 6 counties in the Northwest Community Care Network and 6 counties in Access III of Community Care of the Lower Cape Fear. Patients were screened using a high-resolution digital retinal camera with images read at a centralized reading center at Wake Forest School of Medicine. RESULTS: A total of 1,688 patients were screened from October 2005 through September 2007. Nearly 15% (282) were found to have mild, nonproliferative-to-proliferative retinopathy, while the majority of patients had no evidence of diabetic retinopathy. Nearly 12% (196) required referral to an ophthalmologist, with 5% (86) requiring urgent referral for potentially sight-threatening retinopathy. LIMITATIONS: We were not able to confirm which patients kept their ophthalmologic appointments; however, we are currently analyzing data from the Medicaid patients in our study who required ophthalmologic referral. CONCLUSIONS: Remote digital retinal screening for diabetic retinopathy is feasible in primary care settings in both urban and rural areas of North Carolina, and it may prove to be an effective means of reaching more patients who require annual screening examinations.

Substrate reduction therapy for Krabbe disease and metachromatic leukodystrophy using a novel ceramide galactosyltransferase inhibitor.

Krabbe disease (KD) and metachromatic leukodystrophy (MLD) are caused by accumulation of the glycolipids galactosylceramide (GalCer) and sulfatide and their toxic metabolites psychosine and lysosulfatide, respectively. We discovered a potent and selective small molecule inhibitor (S202) of ceramide galactosyltransferase (CGT), the key enzyme for GalCer biosynthesis, and characterized its use as substrate reduction therapy (SRT). Treating a KD mouse model with S202 dose-dependently reduced GalCer and psychosine in the central (CNS) and peripheral (PNS) nervous systems and significantly increased lifespan. Similarly, treating an MLD mouse model decreased sulfatides and lysosulfatide levels. Interestingly, lower doses of S202 partially inhibited CGT and selectively reduced synthesis of non-hydroxylated forms of GalCer and sulfatide, which appear to be the primary source of psychosine and lysosulfatide. Higher doses of S202 more completely inhibited CGT and reduced the levels of both non-hydroxylated and hydroxylated forms of GalCer and sulfatide. Despite the significant benefits observed in murine models of KD and MLD, chronic CGT inhibition negatively impacted both the CNS and PNS of wild-type mice. Therefore, further studies are necessary to elucidate the full therapeutic potential of CGT inhibition.

Scaling advantage over path-integral Monte Carlo in quantum simulation of geometrically frustrated magnets.

The promise of quantum computing lies in harnessing programmable quantum devices for practical applications such as efficient simulation of quantum materials and condensed matter systems. One important task is the simulation of geometrically frustrated magnets in which topological phenomena can emerge from competition between quantum and thermal fluctuations. Here we report on experimental observations of equilibration in such simulations, measured on up to 1440 qubits with microsecond resolution. By initializing the system in a state with topological obstruction, we observe quantum annealing (QA) equilibration timescales in excess of one microsecond. Measurements indicate a dynamical advantage in the quantum simulation compared with spatially local update dynamics of path-integral Monte Carlo (PIMC). The advantage increases with both system size and inverse temperature, exceeding a million-fold speedup over an efficient CPU implementation. PIMC is a leading classical method for such simulations, and a scaling advantage of this type was recently shown to be impossible in certain restricted settings. This is therefore an important piece of experimental evidence that PIMC does not simulate QA dynamics even for sign-problem-free Hamiltonians, and that near-term quantum devices can be used to accelerate computational tasks of practical relevance.

Comparison of Tissue Molecular Biomarker Testing Turnaround Times and Concordance Between Standard of Care and the Biocartis Idylla Platform in Patients With Colorectal Cancer.

OBJECTIVES: Management of colorectal cancer warrants mutational analysis of KRAS/NRAS when considering anti-epidermal growth factor receptor therapy and BRAF testing for prognostic stratification. In this multicenter study, we compared a fully integrated, cartridge-based system to standard-of-care assays used by participating laboratories. METHODS: Twenty laboratories enrolled 874 colorectal cancer cases between November 2017 and December 2018. Testing was performed on the Idylla automated system (Biocartis) using the KRAS and NRAS-BRAF cartridges (research use only) and results compared with in-house standard-of-care testing methods. RESULTS: There were sufficient data on 780 cases to measure turnaround time compared with standard assays. In-house polymerase chain reaction (PCR) had an average testing turnaround time of 5.6 days, send-out PCR of 22.5 days, in-house Sanger sequencing of 14.7 days, send-out Sanger of 17.8 days, in-house next-generation sequencing (NGS) of 12.5 days, and send-out NGS of 20.0 days. Standard testing had an average turnaround time of 11 days. Idylla average time to results was 4.9 days with a range of 0.4 to 13.5 days. CONCLUSIONS: The described cartridge-based system offers rapid and reliable testing of clinically actionable mutation in colorectal cancer specimens directly from formalin-fixed, paraffin-embedded tissue sections. Its simplicity and ease of use compared with other molecular techniques make it suitable for routine clinical laboratory testing.

Ablative fractionated erbium:YAG laser for the treatment of ice pick alar scars due to neodymium:YAG laser burns.

The authors present a case of ice pick scars forming in the nasal alar grooves of a patient who was treated with a 1064-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for facial telangiectasias. Treatment options for these types of scars are reviewed and specifically we report the success of an ablative fractionated 2940-nm erbium:yttrium-aluminum-garnet (Er:YAG) laser.

Split-face Evaluation of a Multi-ingredient Brightening Foam Versus a Reference Control in Women with Photodamaged Facial Skin.

Background: The gold standard for the treatment of hyperpigmentation is hydroquinone (HQ), which has been available as a skin lightener for more than 50 years. Numerous clinical studies have proven its efficacy in various topical formulations. In the United States, HQ is available as a nonprescription product in 2% formulations and as a 4% prescription product. Objective: This study compared the safety and efficacy of a 2% hydroquinone multi-ingredient foam with a standard 4% hydroquinone cream on photodamaged facial skin. Methods: A 12-week, investigator-blinded, randomized trial with a split-face design was conducted in women with moderate photodamaged facial skin. Results: Both products improved the appearance of photodamaged facial skin and were well-tolerated. No statistically significant changes were seen between treatments during the efficacy or tolerability evaluations. Conclusion: Both treatments (2% HQ Brighten and 4% HQ) improved the appearance of photodamaged facial skin and were well-tolerated and results well-perceived by subjects over the 12-week treatment period, compared with baseline grading scores.

Mirror Image Video Artifact: An Under-Reported Digital Video-EEG Artifact.

Synchronous video recording can be helpful in EEG recordings, especially in recognition of seizures and in rejection of artifacts. However, video recordings themselves are also subject to the risk of contamination by artifacts. We report a unique case in which a digital video artifact was identified, occurring during synchronous video-EEG recording, albeit independently of the EEG tracing itself. A synchronous digital video-EEG recording was performed on a 67-year-old male who presented in focal motor status epilepticus. During the initial review of the data, right-sided abnormalities on EEG apparently corresponded with (ipsilateral) right arm motor activity on video, suggesting a nonsensical anatomical localization. However, review of the patient's chart and discussion with the EEG technologist led to the recognition that the video data recorded a mirror image of the true findings of left arm motor activity. Review of the software settings led to the discovery that the video recording was inverted along the vertical axis, leading to mirror image video artifact. Recognition of this video artifact allowed for accurate interpretation of the study-that right hemispheric EEG abnormalities correlated appropriately with (contralateral) left arm twitching. Effective communication between the EEG reading physician, the treating team, and the EEG technologist is critical for recognition of such artifacts, for proper EEG interpretation, and for appropriate patient management. Mirror image video artifact affirms that bedside evaluation, astute technologists, and attentive EEG reading physicians remain important, even in the presence of video recording.

Genetic analysis of soluble N-ethylmaleimide-sensitive factor attachment protein function in Drosophila reveals positive and negative secretory roles.

The N-ethylmaleimide-sensitive factor (NSF) and soluble NSF attachment protein (SNAP) are cytosolic factors that promote vesicle fusion with a target membrane in both the constitutive and regulated secretory pathways. NSF and SNAP are thought to function by catalyzing the disassembly of a SNAP receptor (SNARE) complex consisting of membrane proteins of the secretory vesicle and target membrane. Although studies of NSF function have provided strong support for this model, the precise biochemical role of SNAP remains controversial. To further explore the function of SNAP, we have used mutational and transgenic approaches in Drosophila to investigate the effect of altered SNAP dosage on neurotransmitter release and SNARE complex metabolism. Our results indicate that reduced SNAP activity results in diminished neurotransmitter release and accumulation of a neural SNARE complex. Increased SNAP dosage results in defective synapse formation and a variety of tissue morphological defects without detectably altering the abundance of neural SNARE complexes. The SNAP overexpression phenotypes are enhanced by mutations in other secretory components and are at least partially overcome by co-overexpression of NSF, suggesting that these phenotypes derive from a specific perturbation of the secretory pathway. Our results indicate that SNAP promotes neurotransmitter release and SNARE complex disassembly but inhibits secretion when present at high abundance relative to NSF.

A genetic screen for synaptic transmission mutants mapping to the right arm of chromosome 3 in Drosophila.

Neuronal function depends upon the proper formation of synaptic connections and rapid communication at these sites, primarily through the regulated exocytosis of chemical neurotransmitters. Recent biochemical and genomic studies have identified a large number of candidate molecules that may function in these processes. To complement these studies, we are pursuing a genetic approach to identify genes affecting synaptic transmission in the Drosophila visual system. Our screening approach involves a recently described genetic method allowing efficient production of mosaic flies whose eyes are entirely homozygous for a mutagenized chromosome arm. From a screen of 42,500 mutagenized flies, 32 mutations on chromosome 3R that confer synaptic transmission defects in the visual system were recovered. These mutations represent 14 complementation groups, of which at least 9 also appear to perform functional roles outside of the eye. Three of these complementation groups disrupt photoreceptor axonal projection, whereas the remaining complementation groups confer presynaptic defects in synaptic transmission without detectably altering photoreceptor structure. Mapping and complementation testing with candidate mutations revealed new alleles of the neuronal fate determinant svp and the synaptic vesicle trafficking component lap among the collection of mutants recovered in this screen. Given the tools available for investigation of synaptic function in Drosophila, these mutants represent a valuable resource for future analysis of synapse development and function.

Structural and kinetic characterization of myoglobins from eurythermal and stenothermal fish species.

Teleost myoglobin (Mb) proteins from four fish species inhabiting different temperature environments were used to investigate the relationship between protein function and thermal stability. Mb was isolated from yellowfin tuna (homeothermal warm), mackerel (eurythermal warm), and the Antarctic teleost Notothenia coriiceps (stenothermal cold). Zebrafish (stenothermal tropical) myoglobin was expressed from cloned cDNA. These proteins differed in oxygen affinity, as measured by O2 dissociation rates and P50 values, and thermal stability as measured by autooxidation rates. Mackerel Mb had the highest P50 value at 25 degrees C (3.7 mmHg), corresponding to the lowest O2 affinity, followed by zebrafish (1.0 mmHg), yellowfin tuna (1.0 mmHg), and N. coriiceps (0.6 mmHg). Oxygen dissociation rates and Arrhenius plots were similar between all teleost species in this study, with the exception of mackerel myoglobin, which was two-fold faster at all temperatures tested. Myoglobin from the Antarctic teleost had the highest autooxidation rate (0.44 h(-1)), followed by mackerel (0.26 h(-1)), zebrafish (0.22 h(-1)), and yellowfin tuna (0.088 h(-1)). Primary structural analysis revealed residue differences distributed throughout the polypeptide sequences, making it difficult to identify, which, if any, residues contribute to structural flexibility. However, analysis of molecular dynamics trajectories indicates that Mb from the eurythermal mackerel is predicted to be the most flexible protein within the D loop and FG turn. At the same time, it has the lowest O2 affinity and the highest O2 dissociation rates when compared to myoglobins from teleosts that appear to be less flexible in our dynamics simulations.

Elevated alpha-synuclein impairs innate immune cell function and provides a potential peripheral biomarker for Parkinson's disease.

Alpha-synuclein protein is strongly implicated in the pathogenesis Parkinson's disease. Increased expression of α-synuclein due to genetic multiplication or point mutations leads to early onset disease. While α-synuclein is known to modulate membrane vesicle dynamics, it is not clear if this activity is involved in the pathogenic process or if measurable physiological effects of α-synuclein over-expression or mutation exist in vivo. Macrophages and microglia isolated from BAC α-synuclein transgenic mice, which overexpress α-synuclein under regulation of its own promoter, express α-synuclein and exhibit impaired cytokine release and phagocytosis. These processes were affected in vivo as well, both in peritoneal macrophages and microglia in the CNS. Extending these findings to humans, we found similar results with monocytes and fibroblasts isolated from idiopathic or familial Parkinson's disease patients compared to age-matched controls. In summary, this paper provides 1) a new animal model to measure α-synuclein dysfunction; 2) a cellular system to measure synchronized mobilization of α-synuclein and its functional interactions; 3) observations regarding a potential role for innate immune cell function in the development and progression of Parkinson's disease and other human synucleinopathies; 4) putative peripheral biomarkers to study and track these processes in human subjects. While altered neuronal function is a primary issue in PD, the widespread consequence of abnormal α-synuclein expression in other cell types, including immune cells, could play an important role in the neurodegenerative progression of PD and other synucleinopathies. Moreover, increased α-synuclein and altered phagocytosis may provide a useful biomarker for human PD.