Changes in electrophysiological findings of spinal muscular atrophy type I after the administration of nusinersen and onasemnogene abeparvovec: two case reports.

BACKGROUND: Recently, there have been significant advances in the treatment of spinal muscular atrophy (SMA). Although clinical improvement in patients with SMA after the treatment has been reported, changes in electrophysiological findings, especially needle electromyography (EMG), have rarely been reported. Herein, we report the posttreatment changes in EMG and nerve conduction study findings over time in two patients with SMA type I. CASE PRESENTATION: Patient 1: A 2.5-year-old girl was diagnosed with SMA type I at 1 month of age. She received nusinersen four times and onasemnogene abeparvovec (OA) was administered at 6 months of age. The compound muscle action potential (CMAP) amplitudes of the median and tibial nerves increased over time. The needle EMG after the treatment showed high-amplitude motor unit potentials (MUPs) suggestive of reinnervation during voluntary contraction, which were not seen before the treatment. However, fibrillation potentials at rest were still seen after the treatment. Patient 2: A 2-year-old girl was diagnosed with SMA type I at 6 months of age. She had received nusinersen two times and OA was administered at 7 months of age. The CMAP amplitudes and the MUPs presented similar changes as presented in Case 1. CONCLUSION: This is the first report on the changes in needle EMG findings after treatment in patients with SMA type I. These findings suggested that peripheral nerve reinnervation occurred after the treatment, although active denervation was still present. The accumulation of these findings will be important for evaluating the effectiveness of treatment for SMA in the future.

Extracellular ADP augments microglial inflammasome and NF-κB activation via the P2Y12 receptor.

The NLRP3 inflammasome is a molecular complex that translates signals from pathogens and tissue damage into inflammatory responses, and plays crucial roles in numerous neurological diseases. Activation of the NLRP3 inflammasome leads to caspase-1 dependent cleavage of pro-IL-1ß to form mature IL-1ß. By acting on the P2X7 purinergic receptor, extracellular ATP is one of the major stimuli that activates the NLRP3 inflammasome. Although microglia express multiple purinergic receptors, their roles in inflammasome-mediated inflammation are largely unknown. We studied the role of the P2Y12 receptor, a metabotropic P2Y receptor enriched in microglia, on inflammation in vitro. Inhibition of the microglial P2Y12 receptor by PSB0739 or siRNA knockdown suppressed IL-1ß release. P2Y12 receptor-deficient microglia displayed markedly attenuated IL-1ß mRNA expression and release. P2Y12 receptor blockade also suppressed IL-6 production. Both IL-1ß and IL-6 responses were augmented by extracellular ADP or ADP-ßS and were abrogated by PSB0739. Mechanistically, ADP-ßS potentiated NF-κB activation. In addition, ADP altered mitochondrial membrane potential in combination with ATP and increased the number of caspase-1 positive cells through the P2Y12 receptor. These results elucidate a novel inflammatory mechanism by which extracellular ADP acts on the P2Y12 receptor to activate NF-κB and the NLRP3 inflammasome to enhance microglial inflammation.

Functional specialization of UDP-glycosyltransferase 73P12 in licorice to produce a sweet triterpenoid saponin, glycyrrhizin.

Glycyrrhizin, a sweet triterpenoid saponin found in the roots and stolons of Glycyrrhiza species (licorice), is an important active ingredient in traditional herbal medicine. We previously identified two cytochrome P450 monooxygenases, CYP88D6 and CYP72A154, that produce an aglycone of glycyrrhizin, glycyrrhetinic acid, in Glycyrrhiza uralensis. The sugar moiety of glycyrrhizin, which is composed of two glucuronic acids, makes it sweet and reduces its side-effects. Here, we report that UDP-glycosyltransferase (UGT) 73P12 catalyzes the second glucuronosylation as the final step of glycyrrhizin biosynthesis in G. uralensis; the UGT73P12 produced glycyrrhizin by transferring a glucuronosyl moiety of UDP-glucuronic acid to glycyrrhetinic acid 3-O-monoglucuronide. We also obtained a natural variant of UGT73P12 from a glycyrrhizin-deficient (83-555) strain of G. uralensis. The natural variant showed loss of specificity for UDP-glucuronic acid and resulted in the production of an alternative saponin, glucoglycyrrhizin. These results are consistent with the chemical phenotype of the 83-555 strain, and suggest the contribution of UGT73P12 to glycyrrhizin biosynthesis in planta. Furthermore, we identified Arg32 as the essential residue of UGT73P12 that provides high specificity for UDP-glucuronic acid. These results strongly suggest the existence of an electrostatic interaction between the positively charged Arg32 and the negatively charged carboxy group of UDP-glucuronic acid. The functional arginine residue and resultant specificity for UDP-glucuronic acid are unique to UGT73P12 in the UGT73P subfamily. Our findings demonstrate the functional specialization of UGT73P12 for glycyrrhizin biosynthesis during divergent evolution, and provide mechanistic insights into UDP-sugar selectivity for the rational engineering of sweet triterpenoid saponins.

Analysis of a plasmid encoding botulinum neurotoxin type G gene in Clostridium argentinense.

Clostridium argentinense produces botulinum neurotoxin type G (BoNT/G). We sequenced and analyzed the plasmid harboring the bont/G gene, designated pCAG, in C. argentinense strain 2740. The pCAG consisted of 140,070 bp containing the bont/G gene cluster. Although this gene cluster showed high similarities in its DNA sequence and ORF arrangement to those of other bont gene clusters, the other regions of the plasmid did not. A phylogenetic study suggested that pCAG had a unique evolutionary history compared with other clostridial bont-harboring plasmids. This suggests that pCAG is possibly a novel type of plasmid expressing the bont/G gene in C. argentinense.

Construction of "Toxin Complex" in a Mutant Serotype C Strain of Clostridium botulinum Harboring a Defective Neurotoxin Gene.

A non-toxigenic mutant of the toxigenic serotype C Clostridium botulinum strain Stockholm (C-St), C-N71, does not produce the botulinum neurotoxin (BoNT). However, the original strain C-St produces botulinum toxin complex, in which BoNT is associated with non-toxic non-hemagglutinin (NTNHA) and three hemagglutinin proteins (HA-70, HA-33, and HA-17). Therefore, in this study, we aimed to elucidate the effects of bont gene knockout on the formation of the "toxin complex." Nucleotide sequence analysis revealed that a premature stop codon was introduced in the bont gene, whereas other genes were not affected by this mutation. Moreover, we successfully purified the "toxin complex" produced by C-N71. The "toxin complex" was identified as a mixture of NTNHA/HA-70/HA-17/HA-33 complexes with intact NTNHA or C-terminally truncated NTNHA, without BoNT. These results indicated that knockout of the bont gene does not affect the formation of the "toxin complex." Since the botulinum toxin complex has been shown to play an important role in oral toxin transport in the human and animal body, a non-neurotoxic "toxin complex" of C-N71 may be valuable for the development of an oral drug delivery system.

Conformational divergence in the HA-33/HA-17 trimer of serotype C and D botulinum toxin complex.

Clostridium botulinum produces a large toxin complex (L-TC) comprising botulinum neurotoxin associated with auxiliary nontoxic proteins. A complex of 33- and 17-kDa hemagglutinins (an HA-33/HA-17 trimer) enhances L-TC transport across the intestinal epithelial cell layer via binding HA-33 to a sugar on the cell surface. At least two subtypes of serotype C/D HA-33 exhibit differing preferences for the sugars sialic acid and galactose. Here, we compared the three-dimensional structures of the galactose-binding HA-33 and HA-33/HA-17 trimers produced by the C-Yoichi strain. Comparisons of serotype C/D HA-33 sequences reveal a variable region with relatively low sequence similarity across the C. botulinum strains; the variability of this region may influence the manner of sugar-recognition by HA-33. Crystal structures of sialic acid- and galactose-binding HA-33 are broadly similar in appearance. However, small-angle X-ray scattering revealed distinct solution structures for HA-33/HA-17 trimers. A structural change in the C-terminal variable region of HA-33 might cause a dramatic shift in the conformation and sugar-recognition mode of HA-33/HA-17 trimer.

Potency and Target Surface Interaction of Diazinoyl Nicotinic Insecticides.

Structure-activity relationships of diazinoyl nicotinic insecticides (diazinoyl isomers and 5- or 6-substituted pyrazin-2-oyl analogues) are considered in terms of affinity to the insect nicotinic acetylcholine receptor (nAChR) and insecticidal activity against the imidacloprid-resistant brown planthopper. Among the test compounds, 3-(6-chloropyridin-3-ylmethyl)-2-(pyrazinoyl)iminothiazoline shows the highest potency in nAChR affinity and insecticidal activity. Aplysia californica acetylcholine binding protein (AChBP) mutants (Y55W + Q57R and Y55W + Q57T) are utilized to compare molecular recognition of nicotinic insecticides with diverse pharmacophores. N-nitro- or N-cyanoimine imidacloprid or acetamiprid, respectively, exhibits a high affinity to these AChBP mutants at a similar potency level. Intriguingly, the pyrazin-2-oyl analogue has a higher affinity to AChBP Y55W + Q57R than that to Y55W + Q57T, thereby indicating that pyrazine nitrogen atoms contact Arg57 guanidinium and Trp55 indole NH. Furthermore, nicotine prefers AChBP Y55W + Q57T over Y55W + Q57R, conceivably suggesting that the protonated nicotine is repulsed by Arg57 guanidinium, consistent with its inferior potency to insect nAChR.

Prediction of the 4-Year Incidence Risk of Ischemic Stroke in Healthy Japanese Adults: The Fukushima Health Database.

AIM: Estimating the risk of developing ischemic stroke (IS) may assist health professionals in motivating individuals to modify their risk behavior. METHODS: A predictive model was derived from 178,186 participants from Fukushima Health Database, aged 40-74 years, who attended the health checkup in 2014 and completed at least one annual health checkup by 2018 (Cohort I). Cox proportional hazard regression model was used to build a 4-year prediction model, thus the risk scores were based on the regression coefficients. External validation for the risk scores was conducted in another cohort of 46,099 participants following between 2015 and 2019 (Cohort II). RESULTS: The 4-year cumulated incidence rate of IS was 179.80/100,000 person-years in Cohort I. The predictive model included age, sex, blood pressure, hypertension treatment, diabetes, low- and high-density lipoprotein cholesterol, smoking, walking pace, and body weight change of 3 kg within one year. Risk scores were interpreted based on the Cohort I predictive model function. The Harrell's C-statistics of the discrimination ability of the risk score model (95% confidence interval) was 0.744 (0.729-0.759) in Cohort I and 0.770 (0.743-0.797) in Cohort II. The overall agreement of the risk score probability of IS incidence for the observed/expected case ratio and 95% CI was 0.98 (0.92-1.05) in Cohort I and 1.08 (0.95-1.22) in Cohort II. CONCLUSIONS: The 4-year risk prediction model revealed a good performance for IS incidence, and risk scores could be used to estimate individual incidence risk of IS. Updated models with additional confirmed risk variables may be needed.

Sugar-induced conformational change found in the HA-33/HA-17 trimer of the botulinum toxin complex.

Large-sized botulinum toxin complex (L-TC) is formed by conjugation of neurotoxin, nontoxic nonhemagglutinin and hemagglutinin (HA) complex. The HA complex is formed by association of three HA-70 molecules and three HA-33/HA-17 trimers, comprised of a single HA-17 and two HA-33 proteins. The HA-33/HA-17 trimer isolated from serotype D L-TC has the ability to bind to and penetrate through the intestinal epithelial cell monolayer in a sialic acid-dependent manner, and thus it plays an important role in toxin delivery through the intestinal cell wall. In this study, we determined the solution structure of the HA-33/HA-17 trimer by using small-angle X-ray scattering (SAXS). The SAXS image of HA-33/HA-17 exhibited broadly similar appearance to the crystal image of the complex. On the other hand, in the presence of N-acetylneuraminic acid, glucose and galactose, the solution structure of the HA-33/HA-17 trimer was drastically altered compared to the structure in the absence of the sugars. Sugar-induced structural change of the HA-33/HA-17 trimer may contribute to cell binding and subsequent transport across the intestinal cell layer.

Random phage display-based screening of peptides that bind to botulinum neurotoxin binding protein, nontoxic nonhemagglutinin.

Botulinum neurotoxin (BoNT) binds to nontoxic nonhemagglutinin (NTNHA) protein in a pH-dependent manner, and yields the protease-resistant BoNT/NTNHA complex. Here, we screened short peptides that bind to the serotype D NTNHA (NTNHA-D) using random phage display technique. NTNHA was fixed onto electrode of quartz crystal microbalance (QCM) apparatus, and then the phages displaying random heptapeptides were exposed to the NTNHA-D under the acidic condition. After rinsing with acidic buffer, the released phages under the alkaline condition were collected. The binding and release of the phage were monitored by the frequency shift on the QCM. As a result of the screening, 16 were selected as peptides that bind to NTNHA-D. The selected peptides do not share any conserved sequence, but tend to be rich in basic and/or hydrophobic amino acid. This would explain the binding manner of the BoNT to the NTNHA protein.

Phospholipase C produced by Clostridium botulinum types C and D: comparison of gene, enzymatic, and biological activities with those of Clostridium perfringens alpha-toxin.

Clostridium botulinum type C and D strains recently have been found to produce PLC on egg yolk agar plates. To characterize the gene, enzymatic and biological activities of C. botulinum PLCs (Cb-PLCs), the cb-plc genes from 8 strains were sequenced, and 1 representative gene was cloned and expressed as a recombinant protein. The enzymatic and hemolytic activities of the recombinant Cb-PLC were measured and compared with those of the Clostridium perfringens alpha-toxin. Each of the eight cb-plc genes encoded a 399 amino acid residue protein preceded by a 27 residue signal peptide. The protein consists of 2 domains, the N- and C-domains, and the overall amino acid sequence identity between Cb-PLC and alpha-toxin was greater than 50%, suggesting that Cb-PLC is homologous to the alpha-toxin. The key residues in the N-domain were conserved, whereas those in the C-domain which are important in membrane interaction were different than in the alpha-toxin. As expected, Cb-PLC could hydrolyze egg yolk phospholipid, p-nitrophenylphosphorylcholine, and sphingomyelin, and also exhibited hemolytic activity;however, its activities were about 4- to over 200-fold lower than those of alpha-toxin. Although Cb-PLC showed weak enzymatic and biological activities, it is speculated that Cb-PLC might play a role in the pathogenicity of botulism or for bacterial survival.

Evaluation of the effect of peptidoglycan-constituting components on photocatalytic bactericidal sterilization.

Previous studies in our lab have shown that peptidoglycan (PG) enhances the photocatalytic bactericidal effect. Therefore, in this study, we focused on the PG-constituting components. The PG-constituting components were added to Mesoplasma florum with no cell wall, respectively, and their effects on photocatalytic sterilization were investigated. The PG-constituting components used were amino sugars, amino acids, L-Alanine-D-Glutamic Acid (L-Ala-D-Glu) dipeptide of diaminopimelic acid (DAP）-type crosslinking peptide, and Lysine (Lys）-type crosslinking peptide. We compared the survival rates of M. florum cells and PG-constituting components-added M. florum cells after 3 h of photocatalytic reaction. Consequently, the survival rates of the cells that were added N-acetylglucosamine (GlcNAc）, DAP, and L-Ala- D-Glu dipeptide were significantly lower than those of only the cells. Furthermore, the amounts of hydrogen peroxide (H2O2) generated by the photocatalytic reaction under the presence of these components were determined. The results showed that DAP, L-Ala- D-Glu dipeptide, and PG of DAP-type significantly increased the amount of H2O2 produced. From the above results, it is suggested that the presence of DAP and L-Ala- D-Glu dipeptide in the photocatalytic reaction boosts the production of H2O2 and enhances the bactericidal effect and that GlcNAc might produce reactive oxygen species other than H2O2.

ATP1A3-related early childhood onset developmental and epileptic encephalopathy responding to corpus callosotomy: A case report.

BACKGROUND: VariousATP1A3variant-related diseases have been reported, including alternating hemiplegia of childhood; rapid-onset dystonia-parkinsonism; and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss syndrome. Moreover, a few cases of developmental and epileptic encephalopathy (DEE) with none of these symptoms have been reported. Here, we present a case of DEE with early childhood onset caused by anATP1A3variant that was effectively treated using corpus callosotomy (CC). CASE PRESENTATION: At the age of 3 years, the patient developed epileptic spasms, complicated by generalized and focal aware tonic seizures. Based on the seizure type and electroencephalographic findings showing a generalized spike and waves as well as interictal left frontal-dominant spikes, combined generalized and focal epilepsy was diagnosed. Whole-exome sequencing revealed a de novo missense variant inATP1A3(c.2888G > A, p.Gly963Asp), which was classified as likely pathogenic. At the age of 5 years, CC for generalized tonic seizures resulted in seizure-freedom using two anti-seizure medications. Subsequently, the patient achieved better verbal development. DISCUSSION AND CONCLUSION: Early childhood onset DEE has not been reported in patients with ATP1A3 variants. Moreover, CC was extremely effective in our case. Although more research is needed to determine the etiology of epilepsy caused by theATP1A3 variant, the clinical course of DEE caused by the ATP1A3 variant is diverse and its prognosis may be improved in early childhood onset cases using aggressive control of epilepsy, such as CC.

Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein.

Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structure classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X(35)-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.

Small-angle X-ray scattering reveals structural dynamics of the botulinum neurotoxin associating protein, nontoxic nonhemagglutinin.

In cell culture supernatants, the botulinum neurotoxin (BoNT) exists as part of a toxin complex (TC) in which nontoxic nonhemagglutinin (NTNHA) and/or hemagglutinins (HAs) are assembled onto the BoNT. A series of investigations indicated that formation of the TC is vital for delivery of the toxin to nerve cells through the digestive tract. In the assembly process, BoNT binds to NTNHA yielding M-TC, and it then matures into L-TC by further association with the HAs via NTNHA in the M-TC. Here, we report a crystal structure of the NTNHA from Clostridium botulinum serotype D strain 4947. Additionally, we performed small-angle X-ray scattering (SAXS) analysis of the NTNHA and the M-TC to elucidate the solution structure. The crystal structure of D-4947 NTNHA revealed that BoNT and NTNHA share a closely related structure consisting of three domains. The SAXS image indicated that, even though the N-terminal two-thirds of the NTNHA molecule had an apparently similar conformation in both the crystal and solution structures, the C-terminal third of the molecule showed a more extended structure in the SAXS image than that seen in the crystallographic image. The discrepancy between the crystal and solution structures implies a high flexibility of the C-terminal third domain of NTNHA, which is involved in binding to BoNT. Structural dynamics of the NTNHA molecule revealed by SAXS may explain its binding to BoNT to form the BoNT/NTNHA complex.

Intraprostatic botulinum neurotoxin type a injection for benign prostatic hyperplasia: preliminary results with a newly purified neurotoxin.

Several studies have demonstrated the efficacy of intraprostatic injection of botulinum neurotoxin type A (BoNT/A) against symptomatic benign prostatic hyperplasia (BPH). The most commonly used BoNT/A product, Botox(®), forms large complexes and composed of neurotoxin (NTX) as well as non-toxic components. We purified NTX lacking non-toxic components. We investigated the efficacy of this newly purified NTX for men with BPH. Ten male patients (mean age, 70.0 years) with BPH received 100 units (prostate volume [PV] ＜30 ml) or 200 units (PV >30 ml) of NTX injected into the prostate via a minimally invasive outpatient technique. Evaluation included uroflowmetry, postvoid residual urine volume (PVR), PV, and International Prostate Symptom Score (IPSS) measured at baseline and 1, 3, 6, and 12 months post-treatment. The status of 7 of the 10 patients examined was found to have improved within 1 month of treatment. The mean IPSS decreased from 23.8 ± 7.0 to 16.3 ± 10.3 (p＝0.0093) at 1 month, to 14.9 ± 8.2 (p＝0.0074) at 3 months, and to 16.9 ± 7.3 (p＝0.018) at 12 months. The mean PV decreased from 47.8 ± 21.2 to 39.2 ± 19.5 ml (p＝0.0076) at 3 months. The PVR improved at 3 and 6 months post-treatment. Intraprostatic NTX injection induces prostate shrinkage and is effective in men with BPH.

Clostridium botulinum type E toxins bind to Caco-2 cells by a different mechanism from that of type A toxins.

Cultured Clostridium botulinum strains produce progenitor toxins designated as 12S, 16S, and 19S toxins. The 12S toxin consists of a neurotoxin (NTX, 7S) and a non-toxic non-hemagglutinin (NTNH). The 16S and 19S toxins are formed by conjugation of the 12S toxin with hemagglutinin (HA), and the 19S toxin is a dimer of the 16S toxin. Type A cultures produce all 3 of these progenitor toxins, while type E produces only the 12S toxin. The 7S toxin is cleaved into heavy (H) and light (L) chains by a protease(s) in some strains, and the H chain has 2 domains, the N-terminus (Hn) and C-terminus (Hc). It has been reported that type A toxins bind to the intestinal cells or cultured cells via either HA or Hc. In this study, we investigated the binding of type A and E toxins to Caco-2 cells using Western blot analysis. Both the type E 7S and 12S toxins bound to the cells, with the 7S toxin binding more strongly, whereas, in the type A strain, only the 16S/19S toxins showed obvious binding. Pre-incubation of the type E 7S toxin with IgG against recombinant type E Hc significantly inhibited the 7S toxin binding, indicating that Hc might be a main binding domain of the type E toxin.

Botulinum toxin type A for the treatment of lower urinary tract disorders.

Many papers report the clinical success of botulinum toxin A as a method of management of various bladder dysfunctions. The rationale was that botulinum toxin A was able to block the presynaptic release of acetylcholine from the parasympathetic efferent nerve. The efficacy might result not only from an inhibitory effect on detrusor muscle, but also some effects might be mediated by altering the afferent nerve input. This systematic literature review discusses the efficacy and safety of botulinum toxin A therapy for idiopathic detrusor overactivity, neurogenic detrusor overactivity, interstitial cystitis/painful bladder syndrome and benign prostatic hyperplasia. The information was gathered from a PubMed literature research for abstracts from recent urological meetings. Injection of botulinum toxin A appears to have a positive therapeutic effect in multiple urological conditions, such as refractory idiopathic detrusor overactivity, neurogenic detrusor overactivity, interstitial cystitis/painful bladder syndrome and benign prostatic hyperplasia. Because the United States Food and Drug Administration has approved botulinum toxin A (Botox) for injection for the treatment of urinary incontinence as a result of neurogenic detrusor overactivity (e.g. spinal cord injury, multiple sclerosis) in adults who have an inadequate response to or are intolerant of an ant cholinergic medication, the use of botulinum toxin A will spread and be a more familiar therapy in the urological arena. However, further robust evidence should be awaited. We will discuss the current use of this agent within the urological field.

[Botulism: structure and function of botulinum toxin and its clinical application].

Clostridium botulinum produces seven immunological distinct poisonous neurotoxins, A to G, with molecular masses of approximately 150kDa. In acidic foods and culture fluid, the neurotoxins associate with non-toxic components, and form large complexes designated progenitor toxins. The progenitor toxins are found in three forms named LL, L, and M. These neurotoxins and progenitor toxins were purified, and whole nucleotide sequences of their structure genes were determined. In this manuscript, the structure and function of these toxins, and the application of these toxins to clinical usage have been described.