Clinical features of a family with late-onset distal hereditary motor neuropathy harboring p.Pro39Leu variant of HSPB1.

BACKGROUND AND AIMS: Pathogenic variants of HSPB1, the gene encoding the small heat shock protein 27, have been reported to cause autosomal dominant distal hereditary motor neuropathy (dHMN) type II and autosomal dominant Charcot-Marie-Tooth (CMT) disease with minimal sensory involvement (CMT2F). This study aimed to describe the clinical features of patients in a family with late-onset dHMN carrying the Pro39Leu variant of HSPB1. METHODS: Whole-exome sequence analysis identified a heterozygous pathogenic variant (Pro39Leu) of HSPB1 in the proband. The presence of the HSPB1 Pro39Leu variant in two affected individuals was confirmed using direct nucleotide sequence analysis. RESULTS: Both patients exhibited distal muscle weakness with lower extremity predominance and no obvious sensory deficits, leading to a clinical diagnosis of late-onset dHMN. Nerve conduction studies (NCSs) revealed a subclinical complication of sensory disturbance in one of the patients. The clinical and electrophysiological findings of patients with the HSPB1 Pro39Leu variant in this study and previous reports are summarized. INTERPRETATION: This study suggests that the clinical spectrum of patients carrying HSPB1 Pro39Leu variants, especially the disease onset, might be broader than expected, and HSPB1 variants should be considered in patients diagnosed with late-onset dHMN. Furthermore, patients with dHMN may have concomitant sensory deficits that should be evaluated using NCSs.

Temporal requirement of dystroglycan glycosylation during brain development and rescue of severe cortical dysplasia via gene delivery in the fetal stage.

Congenital muscular dystrophies (CMDs) are characterized by progressive weakness and degeneration of skeletal muscle. In several forms of CMD, abnormal glycosylation of α-dystroglycan (α-DG) results in conditions collectively known as dystroglycanopathies, which are associated with central nervous system involvement. We recently demonstrated that fukutin, the gene responsible for Fukuyama congenital muscular dystrophy, encodes the ribitol-phosphate transferase essential for dystroglycan function. Brain pathology in patients with dystroglycanopathy typically includes cobblestone lissencephaly, mental retardation, and refractory epilepsy; however, some patients exhibit average intelligence, with few or almost no structural defects. Currently, there is no effective treatment for dystroglycanopathy, and the mechanisms underlying the generation of this broad clinical spectrum remain unknown. Here, we analysed four distinct mouse models of dystroglycanopathy: two brain-selective fukutin conditional knockout strains (neuronal stem cell-selective Nestin-fukutin-cKO and forebrain-selective Emx1-fukutin-cKO), a FukutinHp strain with the founder retrotransposal insertion in the fukutin gene, and a spontaneous Large-mutant Largemyd strain. These models exhibit variations in the severity of brain pathology, replicating the clinical heterogeneity of dystroglycanopathy. Immunofluorescence analysis of the developing cortex suggested that residual glycosylation of α-DG at embryonic day 13.5 (E13.5), when cortical dysplasia is not yet apparent, may contribute to subsequent phenotypic heterogeneity. Surprisingly, delivery of fukutin or Large into the brains of mice at E12.5 prevented severe brain malformation in Emx1-fukutin-cKO and Largemyd/myd mice, respectively. These findings indicate that spatiotemporal persistence of functionally glycosylated α-DG may be crucial for brain development and modulation of glycosylation during the fetal stage could be a potential therapeutic strategy for dystroglycanopathy.

A Metal-Free Approach to 1,2-Diamines via Visible Light-Driven Reductive Coupling of Imines with Perylene as a Photoredox Catalyst.

A simple, metal-free, and versatile approach to 1,2-diamines has been developed based on reductive coupling reactions of various imines, where perylene, an aromatic hydrocarbon, was used as a photoredox catalyst under visible light irradiation using a white light-emitting diode. The use of 1 mol % perylene enabled almost complete conversion of the imines, leading to the formation of their corresponding 1,2-diamines, which were isolated in good yields. The ratios between dl and meso diamines ranged from 31:69 to 82:18 depending on the substituents of the imines.

Special Issue "Ring-Opening Polymerization".

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Solid-state circularly polarised luminescence of atropisomeric fluorophores embedded in achiral myo-inositol-containing polyurethanes.

We investigated the ground- and photoexcited-state chiralities of two chiral fluorophores with a rigid framework embedded in two achiral polyurethanes as the solid matrices. As the fluorophores, we used two pairs of atropisomeric binaphthyl derivatives, (R)-(−)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate [(R)-1a] and (R)-(−)-(3,5-dioxa-4-phosphacyclohepta-[2,1-a:3,4-a']dinaphthalen-4-yl)-dimethylamine [(R)-1b], and for comparison, their optical antipodes (S)-1a and (S)-1b. As the solid matrices, we used two soluble achiral polyurethanes (2a and 2b) derived from the naturally occurring myo-inositol as the building block, because these polymers had a high glass transition temperature of ~150 °C. The chiral fluorophores in the polyurethanes emitted circularly polarised luminescence with a high circular anisotropy of ~0.6­1.5 × 10(-3). Regardless of the matrix, (R)- and (S)-1a had nearly mirror-image chiroptical properties in the ground and photoexcited states, as did (R)- and (S)-1b.

Anti-neurofascin 155 Antibody-positive Neuropathy in a Human Immunodeficiency Virus-infected Patient.

Human immunodeficiency virus (HIV)-associated neuropathy is a common complication of HIV infection and has several clinical subtypes. HIV-associated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a demyelinating neuropathy whose clinical features are known to differ from those of CIDP in the HIV-uninfected population. We herein report a case of CIDP in an HIV-infected patient who was finally diagnosed with anti-neurofascin 155 (NF155) antibody-positive neuropathy. The clinical features, including clinical findings and therapeutic responses, were typical of paranodal antibody-mediated neuropathy. To our knowledge, this is the first case of anti-NF155 antibody-associated neuropathy in an HIV-infected patient.

Absence of post-phosphoryl modification in dystroglycanopathy mouse models and wild-type tissues expressing non-laminin binding form of α-dystroglycan.

α-Dystroglycan (α-DG) is a membrane-associated glycoprotein that interacts with several extracellular matrix proteins, including laminin and agrin. Aberrant glycosylation of α-DG disrupts its interaction with ligands and causes a certain type of muscular dystrophy commonly referred to as dystroglycanopathy. It has been reported that a unique O-mannosyl tetrasaccharide (Neu5Ac-α2,3-Gal-ß1,4-GlcNAc-ß1,2-Man) and a phosphodiester-linked modification on O-mannose play important roles in the laminin binding activity of α-DG. In this study, we use several dystroglycanopathy mouse models to demonstrate that, in addition to fukutin and LARGE, FKRP (fukutin-related protein) is also involved in the post-phosphoryl modification of O-mannose on α-DG. Furthermore, we have found that the glycosylation status of α-DG in lung and testis is minimally affected by defects in fukutin, LARGE, or FKRP. α-DG prepared from wild-type lung- or testis-derived cells lacks the post-phosphoryl moiety and shows little laminin-binding activity. These results show that FKRP is involved in post-phosphoryl modification rather than in O-mannosyl tetrasaccharide synthesis. Our data also demonstrate that post-phosphoryl modification not only plays critical roles in the pathogenesis of dystroglycanopathy but also is a key determinant of α-DG functional expression as a laminin receptor in normal tissues and cells.

Asymptomatic myocardial infarction in a patient with myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) displays a wide range of cardiac manifestations, including conduction system disturbances, arrhythmias, and cardiomyopathy. As a result of progressive myocardial injury and fibrosis, patients with DM1 frequently show electrocardiogram (ECG) abnormalities which sometimes cannot be differentiated from myocardial ischemia. Even in DM1 cases with ECG findings indicative of coronary artery disease, coronary angiography and coronary computed tomography often demonstrate intact coronary arteries. In this article, we report a case of a 56-year-old DM1 patient with ST segment change on ECG, who was admitted to our hospital for further examination. Echocardiography revealed severe hypokinesis in the anteroseptal wall and left ventricular thrombus in the apex, suggesting the possibility of an old myocardial infarction in the left anterior descending artery (LAD) region. Coronary computed tomography angiography and coronary angiography demonstrated a severe stenosis suggestive of vulnerable plaque in the proximal part of LAD, although fractional flow reserve of the lesion did not indicate functional ischemia. A beta-blocker and a sodium-glucose cotransporter 2 inhibitor were introduced expecting a cardioprotective effect. One year after his discharge, the patient died of septic and cardiogenic shock triggered by aspiration pneumonia. Learning objective: Although the prevalent cardiac manifestations of patients with myotonic dystrophy type 1 are conduction abnormalities and cardiomyopathy, the possibility of having coronary artery disease should be considered because they often have some atherosclerotic risk factors with their tendency toward metabolic abnormalities such as diabetes mellitus due to insulin resistance and dyslipidemia and with diagnostic difficulty due to asymptomatic or non-specific manifestations.

Well-Defined Construction of Functional Macromolecular Architectures Based on Polymerization of Amino Acid Urethanes.

Polypeptide synthesis was accomplished using the urethane derivatives of amino acids as monomers, which can be easily prepared, purified, and stored at ambient temperature without the requirement for special precautions. The urethanes of amino acids are readily synthesized by the N-carbamoylation of onium salts of amino acids using diphenyl carbonate (DPC). The prepared urethanes are then efficiently cyclized to produce amino acid N-carboxyanhydrides (NCAs). Thereafter, in the presence of primary amines, the ring-opening polymerization (ROP) of NCAs is initiated using the amines, to yield polypeptides with controlled molecular weights. The polypeptides have propagating chains bearing reactive amino groups and initiating chain ends endowed with functional moieties that originate from the amines. Aiming to benefit from these interesting characteristics of the polypeptide synthesis using the urethanes of amino acids, various macromolecular architectures containing polypeptide components have been constructed and applied as biofunctional materials in highly efficient antifouling coatings against proteins and cells, as biosensors for specific molecules, and in targeted drug delivery.

Solid-state AIEnh-circularly polarised luminescence of chiral perylene diimide fluorophores.

Solid-state organic fluorescent materials are important for the development of electroluminescent sensing devices. Herein, we report that N,N'-bis((R)-1-phenylethyl)perylene-3,4,9,10-tetracarboxylic diimide [(R,R)-BPP] and its antipode [(S,S)-BPP], which contain extended π-electrons through planar perylenes, emit solid-state aggregation-induced-enhanced (AIEnh) circularly polarised luminescence (CPL) in inorganic (KBr) pellets and organic-polymer-film (PMMA- and myo-IPU-film) states; this CPL is difficult to observe in solution. These chiral perylene fluorophores emit AIEnh-CPL with high dissymmetry factors (g CPL) (up to 2.4 × 10-3) and high quantum yields (Φ F, up to 0.43) in the three solid matrices.

Susceptibility of Plasmodium falciparum cyclic AMP-dependent protein kinase and its mammalian homologue to the inhibitors.

Cyclic AMP-dependent protein kinase (protein kinase A, PKA) is a key element in many cell signaling pathways. An essential role of Plasmodium falciparum PKA (PfPKA) activity was reported in the intraerythrocytic growth of the malaria parasite. However, molecular characterization of PfPKA using purified recombinant proteins has not yet been performed. Here, we report the first successful purification of the enzymatically active PKA catalytic subunit of P. falciparum (PfPKA-C) using a wheat germ cell-free expression system. Interestingly, parasite enzymatic activity was weakly inhibited as compared with the inhibition of mammalian PKA catalytic subunit (PKA-C) by the specific PKA inhibitor, H89. Furthermore, PfPKA-C was only slightly inhibited by protein kinase inhibitor (PKI). These results suggest that substrate sites of PfPKA-C may be different from those of mammalian PKA-Cs. In addition, potential PKI corresponding to malarial PKA-C would also be different from those of mammalian cells.

Characterization of Plasmodium falciparum protein kinase 2.

A sustained elevation of free Ca(2+) is observed on the rupture and release of merozoites of Plasmodium falciparum from the erythrocytes. The immunoelectron micrographs demonstrate that calmodulin is localized in merozoites. To elucidate the Ca(2+) signal of P. falciparum invasion, we attempted to characterize P. falciparum protein kinase 2 (PfPK2), which is homologous to human calcium calmodulin-dependent protein kinase (CaMK). PfPK2 was purified as a fusion protein that was labeled with [gamma-(32)P]ATP; this labeling was then eliminated by phosphatase. This phosphorylation was eliminated when the putative catalytic lysine residue of PfPK2 was replaced with alanine. PfPK2 phosphorylated histone II(AS) as a representative substrate in a Ca(2+)- and calmodulin-dependent manner. Calmodulin antagonists inhibited the phosphorylation of PfPK2 in vitro and markedly decreased the parasitemia of ring forms in an invasion assay, whereas CaMKII-specific inhibitors had no effect. PfPK2 was localized in the merozoites in the culture of P. falciparum. Thus, purified PfPK2 possesses protein kinase activity in a Ca(2+)- and calmodulin-dependent manner and the catalytic lysine of this protein was determined. These data suggest that PfPK2 is the Plasmodium protein kinase expressed in the merozoites during the invasion stage.

[A case of recurrent esophageal cancer responding to second-line chemotherapy of TS-1/docetaxel combination].

A 70-year-old man suffering from advanced esophageal cancer (Stage II) underwent subtotal esophagectomy in December 2000. He then had postoperative chemotherapy, called low-dose FP, and was followed in an ambulatory setting. In December 2003, he was diagnosed as a recurrence of esophageal cancer with multiple liver metastases and upper mediastinum lymph node, so he was treated by combined chemotherapy consisting of TS-1 and docetaxel as a second-line chemotherapy. After 3 courses of this therapy, CT scan showed that the size of liver and lymph node metastases was reduced and the effect of this therapy was PR. PR continued for about 6 months. This chemotherapy made it possible to treat liver and lymph node metastasis in an ambulatory setting. It is conceivable that this combination chemotherapy might be a promising regimen for a short period.

Metal-free reductive coupling of C[double bond, length as m-dash]O and C[double bond, length as m-dash]N bonds driven by visible light: use of perylene as a simple photoredox catalyst.

Perylene, a simple polycyclic aromatic hydrocarbon, was used as a photoredox catalyst to enable the reductive coupling reaction of aromatic aldehydes, ketones, and an imine under visible-light irradiation using a white LED.

Controlled monomer insertion into polymer main chain: synthesis of sequence ordered polystyrene containing thiourethane and trithiocarbonate units by the RAFT process.

A polymer having a trithiocarbonate moiety in the main chain was applied as a polymeric precursor to the synthesis of a sequence ordered polymer by insertion polymerization of styrene into the main chain by a RAFT mechanism.

Synthesis of Oligo(spiroketal)s from Naturally Occurring myo-Inositol.

Dehydrating polycondensation of tetraol-type monomers derived from naturally occurring myo-inositol with 1,4-cyclohexanedione formed a series of oligo(spiroketal)s. One of the spiroketals had reactive allyl pendants, which were useful for side-chain modifications via thiol-ene chemistry.

TRPV2 is critical for the maintenance of cardiac structure and function in mice.

The heart has a dynamic compensatory mechanism for haemodynamic stress. However, the molecular details of how mechanical forces are transduced in the heart are unclear. Here we show that the transient receptor potential, vanilloid family type 2 (TRPV2) cation channel is critical for the maintenance of cardiac structure and function. Within 4 days of eliminating TRPV2 from hearts of the adult mice, cardiac function declines severely, with disorganization of the intercalated discs that support mechanical coupling with neighbouring myocytes and myocardial conduction defects. After 9 days, cell shortening and Ca(2+) handling by single myocytes are impaired in TRPV2-deficient hearts. TRPV2-deficient neonatal cardiomyocytes form no intercalated discs and show no extracellular Ca(2+)-dependent intracellular Ca(2+) increase and insulin-like growth factor (IGF-1) secretion in response to stretch stimulation. We further demonstrate that IGF-1 receptor/PI3K/Akt pathway signalling is significantly downregulated in TRPV2-deficient hearts, and that IGF-1 administration partially prevents chamber dilation and impairment in cardiac pump function in these hearts. Our results improve our understanding of the molecular processes underlying the maintenance of cardiac structure and function.

Polymerization-Depolymerization System Based on Reversible Addition-Dissociation Reaction of 1,3-Benzoxazine with Thiol.

The reversible nature of the addition reaction of 1,3-benzoxazine and thiol at ambient temperature was discovered by investigating the reaction with using p-cresol-derived N-phenyl benzoxazine 1 and 1-octadecanethiol 2. The reaction was performed in several deuteriated media involving CDCl3 and CDCl3 + CD3OD, for monitoring their reaction by 1H NMR spectrometry. CDCl3 was a favorable solvent for the efficient progress of the reaction, and its combination with CD3OD allowed further acceleration of the reaction. In both cases, the reaction proceeded until conversion of 1 reached a certain ceiling value, to suggest that the reaction was reversible. This reversible nature was concretely confirmed by finding a dissociation reaction of isolated 3 into 1 and 2 in CDCl3. Analogously, a bisphenol A-derived bifunctional benzoxazine 4 and 1,6-hexanedithiol 5 underwent the polyaddition in CDCl3 + CD3OD at ambient temperature to afford the corresponding polymer 6. Successful depolymerization of 6 into small fragments was achieved by dissolving 6 in CDCl3.

Identification of Toxoplasma gondii cAMP dependent protein kinase and its role in the tachyzoite growth.

BACKGROUND: cAMP-dependent protein kinase (PKA) has been implicated in the asexual stage of the Toxoplasma gondii life cycle through assaying the effect of a PKA-specific inhibitor on its growth rate. Since inhibition of the host cell PKA cannot be ruled out, a more precise evaluation of the role of PKA, as well as characterization of the kinase itself, is necessary. METHODOLOGY/PRINCIPAL FINDING: The inhibitory effects of two PKA inhibitors, H89, an ATP-competitive chemical inhibitor, and PKI, a substrate-competitive mammalian natural peptide inhibitor, were estimated. In the in vitro kinase assay, the inhibitory effect of PKI on a recombinant T. gondii PKA catalytic subunit (TgPKA-C) was weaker compared to that on mammalian PKA-C. In a tachyzoite growth assay, PKI had little effect on the growth of tachyzoites, whereas H89 strongly inhibited it. Moreover, T. gondii PKA regulatory subunit (TgPKA-R)-overexpressing tachyzoites showed a significant growth defect. CONCLUSIONS/SIGNIFICANCE: Our data suggest that PKA plays an important role in the growth of tachyzoites, and the inhibitory effect of substrate-competitive inhibitor PKI on T. gondii PKA was low compared to that of the ATP competitive inhibitor H89.