Botulinum Neurotoxin Type A Research Articles

How satisfied are cervical dystonia patients after 3\xa0years of botulinum toxin type A treatment? Results from a prospective, long-term observational study

BackgroundPatients with cervical dystonia (CD) typically require regular injections of botulinum toxin to maintain symptomatic control. We aimed to document long-term patient satisfaction with CD symptom control in a large cohort of patients treated in routine practice.MethodsThis was a prospective, international, observational study (NCT01753349) following the course of adult CD treated with botulinum neurotoxin type A (BoNT-A) over 3 years. A comprehensive clinical assessment status was performed at each injection visit and subjects reported satisfaction in two ways: satisfaction with symptom control at peak effect and at the end of treatment cycle.ResultsSubject satisfaction remained relatively stable from the first to the last injection visit. At 3 years, 89.9% of subjects reported satisfaction with symptom control at peak effect and 55.6% reported satisfaction with symptom control at end of treatment cycle. By contrast, objective ratings of CD severity showed an overall reduction over 3 years. Mean ± SD Toronto Western Spasmodic Rating Scale (TWSTRS) Total scores (clinician assessed at end of treatment cycle) decreased from 31.59 ± 13.04 at baseline to 24.49 ± 12.43 at 3 years (mean ± SD reduction from baseline of − 6.97 ± 11.56 points). Tsui scale scores also showed gradual improvement; the percent of subjects with a tremor component score of 4 reduced from 12.4% at baseline to 8.1% at 3 years.ConclusionsDespite objective clinical improvements over 3 years, subject satisfaction with symptom control remained relatively constant, indicating that factors other than symptom control also play a role in patient satisfaction.

A sensitive thrombin-linked sandwich immunoassay for protein targets using high affinity phosphorodithioate modified aptamer for thrombin labeling

Thrombin and its aptamers have been well studied and widely used as models in aptamer based assays and sensors. Here we reported a thrombin-linked sandwich immunoassay for proteins to demonstrate new applications of thrombin and the aptamers, converting protein detection to analysis of thrombin label. In this assay, target protein was sandwiched by the capture antibody on a microplate and the biotinylated detection antibody. Thrombin bound to one biotinylated aptamer, and then the thrombin-labeled aptamer was attached on the sandwich complex through streptavidin-biotin interaction by using streptavidin as a linker. Thrombin catalyzed cleavage of fluorogenic peptide substrates, generating fluorescence signals for target detection. Among a few different anti-thrombin aptamers, the use of one nuclease resistant RNA aptamer having phosphorodithioate (PS2) modification on a specific backbone position enabled higher assay sensitivity due to its much higher affinity. This thrombin-linked sandwich immunoassay allowed detection of prostate-specific antigen (PSA) at 2 pM, an important protein related cancer disease, with high sensitivity and specificity. The strategy was general, and also enabled sensitive detection of botulinum neurotoxin type A (BoNTA) light chain, one toxin protein causing risk to human health. This assay combines advantages of antibody recognition, aptamer affinity labeling, high affinity of aptamers, and enzyme activity of thrombin. Labeling thrombin on the immunosandwich complex through simple affinity binding overcomes limitations of covalent conjugating enzyme on antibody in conventional immunoassay. This assay is promising in applications for protein detection.

Gambierol Potently Increases Evoked Quantal Transmitter Release and Reverses Pre- and Post-Synaptic Blockade at Vertebrate Neuromuscular Junctions

Gambierol is a marine polycyclic ether toxin, first isolated from cultured Gambierdiscus toxicus dinoflagellates collected in French Polynesia. The chemical synthesis of gambierol permitted the analyses of its mode of action which includes the selective inhibition of voltage-gated K+ (KV) channels. In the present study we investigated the action of synthetic gambierol at vertebrate neuromuscular junctions using conventional techniques. Gambierol was studied on neuromuscular junctions in which muscle nicotinic ACh receptors have been blocked with d-tubocurarine (postsynaptic block), or in junctions in which quantal ACh release has been greatly reduced by a low Ca2+–high Mg2+ medium or by botulinum neurotoxin type-A (BoNT/A) (presynaptic block). Results show that nanomolar concentrations of gambierol inhibited the fast K+ current and prolonged the duration of the presynaptic action potential in motor nerve terminals, as revealed by presynaptic focal current recordings, increased stimulus-evoked quantal content in junctions blocked by high Mg2+–low Ca2+ medium, and by BoNT/A, reversed the postsynaptic block produced by d-tubocurarine and increased the transient Ca2+ signals in response to nerve-stimulation (1–10 Hz) in nerve terminals loaded with fluo-3/AM. The results suggest that gambierol, which on equimolar basis is more potent than 3,4-diaminopyridine, can have potential application in pathologies in which it is necessary to antagonize pre- or post-synaptic neuromuscular block, or both.This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.

Effects of chronic treatment with botulinum toxin type A in salivary glands of rats: Histological and immunohistochemical analyses.

The intraglandular application of botulinum neurotoxin type A (BoNT-A) is used in patients with neuromotor disorders to control the escape of saliva. The aim of this study was to analyze the impact of repeated treatment with BoNT-A on the submandibular-sublingual complex of rats. A total of 35 Wistar rats were divided into three groups: control group (C), in which animals were not treated; group B, treated with 2.5 U intraglandular injections of BoNT-A (Prosigne® ) and group G, that received bovine gelatine (Prosigne stabilizer). Three applications were performed in intervals of 35days. Twelve and 35days after ending the treatment, submandibular-sublingual complex was collected for histological analysis. Immunohistochemical reactions for calponin and specific muscle actin were also performed, besides detection of apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. A decrease in mucosal and serous acini diameter was observed, with increased interstitial space after 12days of treatment with BoNT-A, which was observed in a lesser degree on the 35th day. At 12days, immunohistochemical analysis revealed a decrease in myoepithelial cells of serous acini in group B. TUNEL methods evidenced apoptosis in animals from group B. BoNT-A caused histological and cellular changes in submandibular-sublingual complex, followed by a tendency toward reversal after 35days. The reversal characteristic of cellular changes in the submandibular-sublingual complex suggests that this BoNT-A formulation may be safely used for sialorrhea treatment.

Botulinum Toxins Type A (Bont-A) in the Management of Lower Limb Spasticity in Children: A Systematic Literature Review and Bayesian Network Meta-analysis.

Background:Botulinum neurotoxins type A (BoNT-As) are used in pediatric lower limb spasticity, which affects more than 2.5 million children worldwide. Botulinum neurotoxins type-A improve active function and delay musculoskeletal complications. The objective of this analysis was to evaluate the efficacy and safety of abobotulinumtoxinA versus other botulinum neurotoxins type A in pediatric spasticity, in the absence of head-to-head evidence.Methods:A systematic literature review was conducted to identify relevant randomized controlled trials. The evidence base was synthesized with Bayesian network meta-analyses. Outcomes analyzed included Modified Ashworth Scale, Tardieu Scale (TS) spasticity grade, and Goal Attainment Scale (standard mean difference only) at 12 weeks postinjection, and adverse events occurring during study periods.Results:Thirty-eight studies were identified, 10 of which met inclusion criteria for quantitative synthesis. On Modified Ashworth Scale, abobotulinumtoxinA 15 U/kg/leg was significantly more efficacious than onabotulinumtoxinA 4 U/kg/leg (–0.99 [–1.34, –0.64]) and onabotulinumtoxinA 4 U/kg/leg+casting (–0.81 [–1.16, –0.46]) and numerically better than onabotulinumtoxinA 8 U/kg (–0.40 [–0.67, –0.14]). AbobotulinumtoxinA 10 U/kg/leg was significantly more efficacious than onabotulinumtoxinA 4 U/kg/leg (±casting). On Goal Attainment Scale, abobotulinumtoxinA 15 U/kg/leg and 10 U/kg/leg were significantly more efficacious than onabotulinumtoxinA 12 U/kg/leg. On Tardieu Scale spasticity grade, abobotulinumtoxinA was comparable to other treatments. AbobotulinumtoxinA demonstrated adverse event rates comparable to all doses of onabotulinumtoxinA.Conclusions:In pediatric lower limb spasticity, abobotulinumtoxinA offered significant or numerical efficacy advantages on tone (Modified Ashworth Scale) and functional outcomes (Goal Attainment Scale), and comparable efficacy on Tardieu Scale spasticity grade. AbobotulinumtoxinA was comparable to onabotulinumtoxinA on tolerability. Results should be interpreted in the context of heterogeneity and sparsity of the evidence base.

Effectiveness of botulinum neurotoxin type A injections in naïve and previously-treated patients suffering from Torti- or Laterocollis or -caput: Results from a German-Austrian open-label prospective post-marketing surveillance study

AbobotulinumtoxinA (aboBoNT-A; Dysport®) is an effective treatment for cervical dystonia (CD) with a well-established safety profile. In this prospective, multicentre, non-interventional study (NCT01840462) the primary objective was effectiveness (Tsui score) of aboBoNT-A in botulinum neurotoxin type A (BoNT-A) treatment-naïve and previously-treated (>2 yrs) patients after two injection cycles (at visit 3). Secondary objectives included the effectiveness of aboBoNT-A overall visits and quality of life (CDQ-24) in different CD subtypes. Observation time was 12–16 months, including 5 visits and 4 injection cycles (each 3–4 months). In the analysis population 273 patients from 41 centres across Germany and Austria were included. At baseline, 62.6% were previously-treated with BoNT-A. The major primary components of CD were torticollis (64.5%) and torticaput (17.6%). Previously-treated patients showed a slight reduction of the Tsui scores, whereas BoNT-A-naïve patients had a more severe baseline Tsui score and improved much more over all cycles. Results were similar for CDQ-24. Interestingly, improvements mainly occurred in the Tsui subscore A (amplitude of sustained posture). Marked differences between CD subtypes regarding effectiveness could not be determined. To our knowledge this is the first large multi-centre study investigating the effectiveness of BoNT-A in different primary subtypes of CD over several injection cycles.

Content/Potency Assessment of Botulinum Neurotoxin Type-A by Validated Liquid Chromatography Methods and Bioassays.

Botulinum neurotoxin type-A (BoNTA) is one of the seven different serotypes (A to G) produced by Clostridium botulinum. A stability-indicating size-exclusion chromatography (SEC) method was developed and validated, and the specificity was confirmed by forced degradation study, interference of the excipients, and peaks purity. The method was applied to assess the content and high-molecular-weight (HMW) forms of BoNTA in biopharmaceutical products, and the results were compared with those of the LD50 mouse bioassay, the T−47D cell culture assay, and the reversed-phase chromatography (RPC) method, giving mean values of 0.71% higher, 0.36% lower, and 0.87% higher, respectively. Aggregated forms showed significant effects on cytotoxicity, as well as a decrease in the bioactivity (p < 0.05). The employment of the proposed method in conjunction with the optimized analytical technologies for the analysis of the intact and altered forms of the biotechnology-derived medicines, in the correlation studies, enabled the demonstration of the capability of each one of the methods and allowed for great improvements, thereby assuring their safe and effective use.

Botulinum neurotoxin a therapy efficacy and safety for oromandibular dystonia: a meta-analysis.

Oromandibular dystonia (OMD) is a focal dystonia involving the mouth, jaw, and tongue. Botulinum neurotoxin (BoNT) therapy might be one form of treatment in OMD. Systematic pooling of BoNT studies in OMD remains wanting, as the derived data could provide useful information in regard to efficacy and safety issues. This meta-analysis determined the effects of botulinum neurotoxin type A (BoNT/A) on the reduction of dystonic movement and its safety among patients with OMD. A systematic search of the literature that met the following eligibility criteria were done: (1) patients treated with BoNT/A for OMD, (2) studies of high methodological quality and (3) outcome criteria specified as regard to efficacy. Risk of unresolved dystonia was computed before and after BoNT/A intervention. Random effect size (p < 0.05ɑ) and test of heterogeneity (< I2 50%) were computed as meta-analysis tool using REVMAN ver 5.3 program. Safety data, where available, were systematically reviewed. Nine studies involved 387 cases in total of OMD. The pooled risk ratio is 0.607 with a confidence interval of 0.371-0.783, a zvalue of 3.85, and a pvalue of 0.0001. Results indicate that risk of dystonic movements is lower by 39.30% in the treatment group than in the control group. A total of 105/387 patients (27.1%) experienced adverse events most commonly dysphagia. Whilst cited literatures have inherent weaknesses, results show that BoNT/A is efficacious in reducing dystonic movements of patients with OMD. Majority of studies employed electromyography (EMG) guidance in muscle targeting. Given the potential adverse event of dysphagia, one may take a cautious stand while delivering injections to target muscles. These findings are congruent with what has been published in regard to efficacy of BoNT/A in focal dystonia.

Super-resolving botulinum neurotoxin type A molecules: from surface landing to internalization in synaptic vesicles

Botulinum neurotoxin type-A (BoNT/A) is internalized into motor nerve terminals as part of its intoxication strategy to incapacitate nerve-muscle communication. The “dual receptor” model explained how BoNT/A initially interacts with GT1b gangliosides, thereby concentrating the toxin on the presynaptic membrane to foster the subsequent interaction with a proteinaceous co-receptor SV2 which triggers receptor-mediated endocytosis. I will revisit the “dual receptor” concept using two single-molecule imaging strategies,1-3 allowing tracking of single Atto647N-labeled BoNT/A molecules upon (i) landing on the plasma membrane (by uPAINT) and (ii) internalization in synaptic vesicles (by sdTIM) of living mature hippocampal neurons. With 30 to 40 nm localization precision, we revealed that once internalized in synaptic vesicles, Atto647N-tagged BoNT/A exhibits a markedly lower mobility than on the plasma membrane. I will discuss how individual genetic inactivation of the GT1b and SV2 binding sites of the neurotoxin affects the diffusion states of BoNT/A mutants on the plasma membrane and axonal trafficking. Single neurotoxin super-resolution imaging uncovers an updated dual receptor model taking into consideration the diffusive patterns generated by each of the co-receptors and leading to defined nanoscale dynamic organizations at key steps of the intoxication journey.

Botulinum neurotoxin type A (BTA) in an ALS patient with local spasticity in the lower limb

Botulinum neurotoxin type A (BTA) in an ALS patient with local spasticity in the lower limb

High prevalence of neutralizing antibodies after long-term botulinum neurotoxin therapy.

To investigate the prevalence of neutralizing antibodies (NAbs) against botulinum neurotoxin type A (BoNT/A) during long-term BoNT/A treatment in different neurologic indications. In this monocentric, observational cross-sectional study, 596 outpatients treated with BoNT/A for different indications were tested for BoNT/A binding antibodies by ELISA. Positive samples were investigated for NAbs with the mouse hemidiaphragm test. The prevalence of NAbs was analyzed for different indications: facial hemispasm, blepharospasm, cervical dystonia, other dystonia, and spasticity. Besides the rate of NAb-positive patients overall and per patient subgroup, a Kaplan-Meier analysis of the probability of remaining NAb negative with duration of treatment is provided, and a stepwise binary logistic regression analysis is performed to identify factors significantly contributing to the induction of NAbs. Overall, 83 of 596 patients (13.9%) had measurable NAbs. The probability of developing NAbs increased with the single and cumulative dose of treatment and was influenced by the BoNT/A formulation, while all other factors analyzed, including disease entity and treatment duration, had no additional influence. We present the largest study to date of the prevalence of BoNT/A NAbs in a large unbiased cohort of patients including the relevant neurologic indications. Repeated injections of BoNT/A inevitably bear the risk of developing NAbs. However, in addition to avoiding booster injections and providing short intervals between injections, reducing the individual injected doses may diminish the risk of NAb induction independently of the indication for which BoNT/A is used.

Topical Botulinum Toxin: A Non-invasive Way for Treatment of Muscle Disorders.

Botulinum neurotoxin type A (BoNT/A) is a toxin that inhibits the release of stimulatory neurotransmitter (acetylcholine) at the neuromuscular synapses. In recent years, many patients with muscle contraction disorders have greatly benefited from the therapeutic ability of this biological drug. On the other hand, the injection of this bio drug is accompanied by some side effects such as irritation, bruising, inflammation, pain, bleeding at the site of injection. Recently, a tendency has been observed among scientists to create new techniques to offer conventional injectable drugs the ability of transdermal delivery. Such promising drugs can be applied in various forms from gel, cream, and ointments to ready-to-use pads. This would eliminate a need for high drug doses to release the drug gradually at the site of application while at the same time, lower the side effects. Here, we discuss the possibility of noninvasive administration of BoNT/A in order to reduce the side effects of drug injection.

Transynaptic Action of Botulinum Neurotoxin Type A at Central Cholinergic Boutons.

Botulinum neurotoxin Type A (BoNT/A) is an effective treatment for several movement disorders, including spasticity and dystonia. BoNT/A acts by cleaving synaptosomal-associated protein of 25 kDa (SNAP-25) at the neuromuscular junction, thus blocking synaptic transmission and weakening overactive muscles. However, not all the therapeutic benefits of the neurotoxin are explained by peripheral neuroparalysis, suggesting an action of BoNT/A on central circuits. Currently, the specific targets of BoNT/A central activity remain unclear. Here, we show that catalytically active BoNT/A is transported to the facial nucleus (FN) after injection into the nasolabial musculature of rats and mice. BoNT/A-mediated cleavage of SNAP-25 in the FN is prevented by intracerebroventricular delivery of antitoxin antibodies, demonstrating that BoNT/A physically leaves the motoneurons to enter second-order neurons. Analysis of intoxicated terminals within the FN shows that BoNT/A is transcytosed preferentially into cholinergic synapses. The cholinergic boutons containing cleaved SNAP-25 are associated with a larger size, suggesting impaired neuroexocytosis. Together, the present findings indicate a previously unrecognized source of reduced motoneuron drive after BoNT/A via blockade of central, excitatory cholinergic inputs. These data highlight the ability of BoNT/A to selectively target and modulate specific central circuits, with consequent impact on its therapeutic effectiveness in movement disorders.SIGNIFICANCE STATEMENT Botulinum neurotoxins are among the most potent toxins known. Despite this, their specific and reversible action prompted their use in clinical practice to treat several neuromuscular pathologies (dystonia, spasticity, muscle spasms) characterized by hyperexcitability of peripheral nerve terminals or even in nonpathological applications (i.e., cosmetic use). Substantial experimental and clinical evidence indicates that not all botulinum neurotoxin Type A (BoNT/A) effects can be explained solely by the local action (i.e., silencing of the neuromuscular junction). In particular, there are cases in which the clinical benefit exceeds the duration of peripheral neurotransmission blockade. In this study, we demonstrate that BoNT/A is transported to facial motoneurons, released, and internalized preferentially into cholinergic terminals impinging onto the motoneurons. Our data demonstrate a direct central action of BoNT/A.

Effects of Botulinum Toxin A Observed During Early Scar Formation Following Rhytidectomy: Controlled, Double-Blinded Pilot Study

Several past studies have suggested there are benefits to using botulinum neurotoxin type A (BoNTA) for improving the aesthetic appearance of established scars. This article describes a study on the prophylactic use of BoNTA for controlling scar formations as they occur. It is based on a small, double-blinded, controlled group of patients having just undergone a facelift procedure. The results suggest that the use of BoNTA just after surgery yield both quantitative and qualitative aesthetic benefits, and the data provide some guidance on optimal doses.

Comparison of botulinum neurotoxin type A formulations in Asia.

ResultsAll protein-based therapeutics, such as botulinum neurotoxin type A (BoNT/A), are potentially immunogenic and can lead to anaphylaxis, autoimmunity, or diminished or complete absence of therapeutic efficacy, especially if administered repeatedly. Therefore, the protein quantity in BoNT/A products is an important consideration when selecting products for treatment. However, essential formulation data are not always publicly accessible.Materials and methodsThe neurotoxin protein content of products newly introduced in Asia, such as (listed alphabetically) Botulax®, Meditoxin®, Nabota®, and Relatox®, was measured by sandwich enzyme-linked immunosorbent assay with antisera directed against BoNT/A compared to Xeomin®.ResultsCompared to Xeomin with no inactive neurotoxin, although Botulax and Nabota contained 844 and 754 pg of neurotoxin protein, respectively, the percentage of inactive neurotoxin was calculated to be 103 and 81, respectively, while the potency per pg of neurotoxin was 0.118 and 0.133 U, respectively. Meditoxin and Relatox had 575 and 578 pg of neurotoxins, respectively, marginally higher than that of Xeomin, while the percentage of inactive neurotoxins was 38 and 33, respectively, and the potency per pg of neurotoxin was 0.174 and 0.173 U, respectively. However, Xeomin, which has 416 pg/vial of purified neurotoxin and 0.240 U of efficacy per pg of neurotoxin, has the lowest neurotoxin protein content and consequently the highest specific potency compared to the four Asian BoNT/A preparations in this study.ConclusionAlthough Botulax and Nabota had more neurotoxin than Xeomin in an equivalent volume, they contained greater amounts of inactive neurotoxin. In addition, although Meditoxin and Relatox had slightly more neurotoxin than Xeomin, both contained greater amounts of inactive neurotoxin.

Don’t Hang Up Your Lead, Yet

Three botulinum neurotoxin type A (BoNT/A) products, incobotulinumtoxinA, onabotulinumtoxinA, and abobotulinumtoxinA, all manufactured by different methods, are employed in clinical practice. Comparing the three BoNT/A products is difficult because their concentrations and volumes differ and the precise dose equivalence ratio is not known. We aimed to compare the neurotoxic potencies by a systematic analysis of injected volume and dose.The potency of BoNT in inducing hind limb paresis was assessed by analyzing the wheel-running performance of mice. To standardize the volume, the effect of an identical dose of incobotulinumtoxinA dissolved in different volumes of saline (15, 10, 5, and 2 μl) was studied in four groups of mice (n = 13–15). The potencies of the BoNT products were then compared by injecting identical volumes (10 μl) containing different doses into both hind leg muscles.Mice injected with incobotulinumtoxinA showed a volume-dependent reduction in wheel-running, with larger volumes inducing more intense paresis. A standardized volume containing the same number of mouse units of the BoNT/A products produced different degrees of paresis. The conversion ratio of incobotulinumtoxinA and onabotulinumtoxinA is estimated to be between 1:0.75 and 1:0.5. OnabotulinumtoxinA displayed a two-fold greater potency than abobotulinumtoxinA. Doses of onabotulinumtoxinA and abobotulinumtoxinA that produce an identical severity of pareses even result in the same duration of pareses.This wheel-running assay allows one to compare the neurotoxic potency of different volumes and doses of the BoNT products in vivo. Our results argue against common clinical practice because incobotulinumtoxinA and onabotulinumtoxinA are not readily interchangeable and a two-fold dose of abobotulinumtoxinA is needed to induce an effect identical to onabotulinumtoxinA. In addition, this emphasizes that the duration of BoNT-induced effect is the same as long as equipotent doses of BoNT are injected.

The mechanism of botulinum A on Raynaud syndrome.

BackgroundBotulinum neurotoxin type A (BoNT/A) is emerging as a treatment modality for Raynaud’s phenomenon (RP). However, the mechanism of the role of BoNT/A in antagonizing the constriction of arteriola in RP remains unclear.Materials and methodsWe tested the constriction of arteriole diameter and the distribution of adrenergic receptors on the rat cremaster modle. Moreover, we measured the secretion of norepinephrine (NE), protein level changes and related receptors on cultured rat superior cervical ganglia neurons(SCGNs), a model of sympathetic neuron.ResultsBased on our results, the inhibition of arteriole vasoconstriction was increased with increasing doses of BoNT/A. BoNT/A, prazosin, and BQ123 treatment can result in significant inhibition of arteriole vasoconstriction with the same electrical stimulation. The inhibition effect of prazosin was equivalent to BoNT/A, while BQ123 has a synergistic effect with BoNT/A. After treating SCGNs using BoNT/A for 30 min, the decrease in fluorescence intensity of FM1-43 slowed down which was correlated with the doses of BoNT/A. Furthermore, release of NE in the supernatant was significantly decreased as measured by enzyme-linked immunosorbent assay, 24 h after a high dose of BoNT/A (25 µ/mL). Cleaved-SNAP-25 was detected by Western blotting 24 h following BoNT/A (50 µ/mL) treatment. Moreover, receptor SV2C, GM1, and FGFR3 were detected on sympathetic neurons, similarly to cholinergic neurons.ConclusionOur study showed that BoNT/A could significantly inhibit electrical stimulation-induced arteriole vasoconstriction through the sympathetic pathway. The mechanism was similar to the cholinergic one, in which the vesicle release of sympathetic neurons could be inhibited by cleavage of SNAP-25. The end result was blocked vesicle fusion with the presynaptic membrane after BoNT/A treatment, inhibiting the release of the NE.

2018 Synaptic vesicle 2 receptors as a novel targets for neuroendocrine cancer therapy

2018 Synaptic vesicle 2 receptors as a novel targets for neuroendocrine cancer therapy

Saliva changes in Parkinson\u2019s disease patients after injection of Botulinum neurotoxin type A

Patients with Parkinson’s disease (PD) are compromised by poor oral condition due to oropharyngeal bradykinesia, dysphagia, and the side effects of treatment. Intrasalivary gland injections of Botulinum neurotoxin type A (BNT-A) have been known to treat sialorrhea effectively in these patients. However, the decreased amount of saliva reduces self-cleaning ability that deteriorates oral hygiene and increases dental caries. The aim of this study was to determine the changes in the oral microflora and saliva in patients with PD treated for sialorrhea by means of sonography-controlled BNT-A injections into the bilateral parotid and submandibular glands. Altogether, 38 persons participated in the study: 12 PD patients who were injected with BNT-A for treatment of sialorrhea and passed salivary tests before and 1 month after the injections; and 13 PD patients and 13 healthy subjects who were not injected with BNT-A and passed salivary tests once. The condition of oral health was measured by the amount of saliva, salivary flow rate, and salivary composition. A good outcome with a significant decrease in salivary flow rate occurred at 1-month follow-up in the BNT-A-treated group while no significant change was found in salivary composition. BNT-A treatment did not change the Streptococcus mutans levels in saliva but there was statistically significant increase in levels of Lactobacilli. BNT-A injections can effectively treat sialorrhea while considering the change of oral microflora, and the patients should be under dentists’ care more frequently. EudraCT clinical trial number: 2015-000682-30.

Inhibition of the proteasome partially attenuates atrophy in botulinum neurotoxin treated skeletal muscle

Botulinum neurotoxin type A (BoNT/A) is used as a therapeutic tool to induce chemical denervation of spastically contracted muscles, yet the neurotoxin can also cause skeletal muscle atrophy. The underlying proteolytic mechanisms that induce this atrophy remain unclear. Our previous work has highlighted increased ubiquitin proteasome system (UPS) activity in soleus muscle of male Sprague Dawley rats following hind limb injection of BoNT/A, with the chymotrypsin-like activity of the 20s proteasome the most active. Thus, we chose to inhibit 20s proteasome activity in BoNT/A injected hind limb to determine the effect on soleus muscle atrophy. Epoxomicin is commonly used to inhibit the proteasome in vivo, binding specifically and irreversibly to the 20s proteasome catalytic subunits. Daily subcutaneous injections of epoxomicin abolished BoNT/A-induced elevations in 20s chymotrypsin-like activity both 3 days and 10 days post BoNT/A injection. Furthermore, BoNT/A-induced elevations in polyubiquitination remained elevated in BoNT/A + epoxomicin treated muscle, presumably due to epoxomicin's inhibition of the proteasome causing a back-up of polyubiquitinated proteins. Despite inhibition of the proteasome, epoxomicin was insufficient to significantly attenuate soleus muscle fiber atrophy 3 days following BoNT/A injection however, 10 days of daily epoxomicin injection was sufficient to spare ∼20% of muscle wasting. The mechanism of the remaining 80% of BoNT/A-induced atrophy presumably occurs via mechanisms outside of the 20s proteasome.