AP2 Regulates Thickveins Trafficking to Attenuate NMJ Growth Signaling in Drosophila.

Compromised endocytosis in neurons leads to synapse overgrowth and altered organization of synaptic proteins. However, the molecular players and the signaling pathways which regulate the process remain poorly understood. Here, we show that σ2-adaptin, one of the subunits of the AP2-complex, genetically interacts with Mad, Medea and Dad (components of BMP signaling) to control neuromuscular junction (NMJ) growth in Drosophila Ultrastructural analysis of σ2-adaptin mutants show an accumulation of large vesicles and membranous structures akin to endosomes at the synapse. We found that mutations in σ2-adaptin lead to an accumulation of Tkv receptors at the presynaptic membrane. Interestingly, the level of small GTPase Rab11 was significantly reduced in the σ2-adaptin mutant synapses. However, expression of Rab11 does not restore the synaptic defects of σ2-adaptin mutations. We propose a model in which AP2 regulates Tkv internalization and endosomal recycling to control synaptic growth.

Chemical profiling, in vitro antioxidant, membrane stabilizing and antimicrobial properties of wild growing Murraya paniculata from Amarkantak (M.P.).

The excessive usage of antibiotics in humans and veterinary medicine has lead to the emergence of antibiotic resistance and now requires the use of novel antibiotics. There has been increased interest towards plants as source of drugs because of their pharmacological potency and long traditional usage. The aim of the current study was to evaluate bioactive components, antioxidant, and anti-inflammatory activities of the leaf extracts of Murraya paniculata, a plant traditionally used in Indian medicinal system. Evaluations were made for phytochemical analysis, antioxidant, membrane stabilizing, and antimicrobial activities. The methanol extract displayed the highest flavonoid and phenolic content, the acetone extract demonstrated considerable ABTS inhibitory activity (IC50value:555.18 ± 1.68 µg/mL) and the hexane extract exhibited highest H2O2 radical scavenging activity (IC50value: 509.84 ± 3.03 µg/mL). The aqueous extract displayed 19.4 ± 0.66% RBC hemolysis and 80.5 ± 0.66% protection caused by hypotonic solution at high concentration of the extract. The fractions of hexane extract revealed a higher zone of inhibition than crude extract. The major components found in the fractions were cyclohexane (40.11%) and 3-(6-Methoxy-3-methyl-2-benzofuranyl) Cyclohexanone (13.68%) as analyzed by GC-MS/MS technique. The current results validate the traditional use of the M. paniculata and warrant its potential in drug development programs in further investigations.

Evaluation of ethnopharmacologically selected Vitex negundo L. for In vitro antimalarial activity and secondary metabolite profiling.

ETHANOPHARMACOLOGICAL RELEVANCE: Limited drugs, rise in drug resistance against frontline anti-malarial drugs, non-availability of efficacious vaccines and high cost of drug development hinders malaria intervention programs. Search for safe, effective and affordable plant based anti-malarial agents, thus becomes crucial and vital in the current scenario. The Vitex negundo L. is medicinal plant possessing a variety of pharmaceutically important compounds. The plant is used traditionally worldwide for the treatment of malaria including India and Malaysia by the indigenous tribes. In vitro studies have reported the anti-malarial use of the plant in traditional medicinal systems. AIM OF THE STUDY: The aim of the current study is to evaluate the traditionally used medicinal plants for in vitro anti-malarial activity against human malaria parasite Plasmodium falciparum and profiling secondary metabolite using spectroscopic and chromatographic methods. Chemical profiling of active secondary metabolites in the extracts was undertaken using LC-MS. MATERIALS AND METHODS: Based on the ethno-botanical data V. negundo L. was selected for in vitro anti-malarial activity against P. falciparum chloroquine-sensitive (3D7) and multidrug resistant (K1) strains using SYBR Green-I based fluorescence assay. Cytotoxicity of extracts was evaluated in VERO cell line using the MTT assay. Haemolysis assay was performed using human red blood cells. Secondary metabolites profiling was undertaken using chromatographic and spectroscopic analysis. Liquid chromatography analysis was performed using a C18, 150 X 2.1, 2.6 µm column with gradient mobile phase Solvent A: 95% (H2O: ACN), Solvent B: Acetonitrile, Solvent C: Methanol, Solvent D: 5 mM NH4 in 95:5 (H2O: ACN) at a constant flow rate of 0.250 ml/min. The LC-MS spectra were acquired in both positive and negative ion modes with electrospray ionization (ESI) source. RESULTS: The anti-malarial active extract of V. negundo L. leaf exhibited potent anti-malarial activity with IC50 values of 7.21 µg/ml and 7.43 µg/ml against 3D7 and K1 strains, respectively with no evidence of significant cytotoxicity against mammalian cell line (VERO) and no toxicity as observed in haemolysis assay. The HPLC-LC-MS analysis of the extract led to identification of 73 compounds. We report for the first time the presence of Sabinene hydrate acetate, 5-Hydroxyoxindole, 2(3,4-dimethoxyphenyl)-6, 7-dimethoxychromen-4-one, Cyclotetracosa-1, 13-diene and 5, 7-Dimethoxyflavanone in the anti-malarial active extract of V. negundo L. leaf. Agnuside, Behenic acid and Globulol are some of the novel compounds with no reports of anti-malarial activity so far and require further evaluation in pure form for the development of potent anti-malarial compounds. CONCLUSIONS: The result report and scientifically validate the traditional use of V. negundo L. for the treatment of malaria providing new avenues for anti-malarial drug development. Several novel and unknown compounds were identified that need to be further characterized for anti-malarial potential.

Regulation of neuromuscular junction organization by Rab2 and its effector ICA69 in Drosophila.

The mechanisms underlying synaptic differentiation, which involves neuronal membrane and cytoskeletal remodeling, are not completely understood. We performed a targeted RNAi-mediated screen of Drosophila BAR-domain proteins and identified islet cell autoantigen 69 kDa (ICA69) as one of the key regulators of morphological differentiation of the larval neuromuscular junction (NMJ). We show that Drosophila ICA69 colocalizes with α-Spectrin at the NMJ. The conserved N-BAR domain of ICA69 deforms liposomes in vitro Full-length ICA69 and the ICAC but not the N-BAR domain of ICA69 induce filopodia in cultured cells. Consistent with its cytoskeleton regulatory role, ICA69 mutants show reduced α-Spectrin immunoreactivity at the larval NMJ. Manipulating levels of ICA69 or its interactor PICK1 alters the synaptic level of ionotropic glutamate receptors (iGluRs). Moreover, reducing PICK1 or Rab2 levels phenocopies ICA69 mutation. Interestingly, Rab2 regulates not only synaptic iGluR but also ICA69 levels. Thus, our data suggest that: (1) ICA69 regulates NMJ organization through a pathway that involves PICK1 and Rab2, and (2) Rab2 functions genetically upstream of ICA69 and regulates NMJ organization and targeting/retention of iGluRs by regulating ICA69 levels.

Whole exome sequencing in an Indian family links Coats plus syndrome and dextrocardia with a homozygous novel CTC1 and a rare HES7 variation.

BACKGROUND: Coats plus syndrome is an autosomal recessive, pleiotropic, multisystem disorder characterized by retinal telangiectasia and exudates, intracranial calcification with leukoencephalopathy and brain cysts, osteopenia with predisposition to fractures, bone marrow suppression, gastrointestinal bleeding and portal hypertension. It is caused by compound heterozygous mutations in the CTC1 gene. CASE PRESENTATION: We encountered a case of an eight-year old boy from an Indian family with manifestations of Coats plus syndrome along with an unusual occurrence of dextrocardia and situs inversus. Targeted resequencing of the CTC1 gene as well as whole exome sequencing (WES) were conducted in this family to identify the causal variations. The identified candidate variations were screened in ethnicity matched healthy controls. The effect of CTC1 variation on telomere length was assessed using Southern blot. A novel homozygous missense mutation c.1451A > C (p.H484P) in exon 9 of the CTC1 gene and a rare 3'UTR known dbSNP variation (c.*556 T > C) in HES7 were identified as the plausible candidates associated with this complex phenotype of Coats plus and dextrocardia. This CTC1 variation was absent in the controls and we also observed a reduced telomere length in the affected individual's DNA, suggesting its likely pathogenic nature. The reported p.H484P mutation is located in the N-terminal 700 amino acid regionthat is important for the binding of CTC1 to ssDNA through its two OB domains. WES data also showed a rare homozygous missense variation in the TEK gene in the affected individual. Both HES7 and TEK are targets of the Notch signaling pathway. CONCLUSIONS: This is the first report of a genetically confirmed case of Coats plus syndrome from India. By means of WES, the genetic variations in this family with unique and rare complex phenotype could be traced effectively. We speculate the important role of Notch signaling in this complex phenotypic presentation of Coats plus syndrome and dextrocardia. The present finding will be useful for genetic diagnosis and carrier detection in the family and for other patients with similar disease manifestations.

Infantile onset spinocerebellar ataxia 2 (SCA2): a clinical report with review of previous cases.

Autosomal dominant cerebellar ataxia type I is a heterogeneous group of spinocerebellar ataxias with variable neurologic presentations, with age of onset varying from infancy to adulthood. Autosomal dominant cerebellar ataxia type I is composed mainly of 3 prevalent spinocerebellar ataxia types with different pathogenic loci, specifically spinocerebellar ataxia 1 (6p24-p23), spinocerebellar ataxia 2 (12q24.1), and spinocerebellar ataxia 3 (14q32.1). The shared pathogenic mutational event is the expansion of the CAG repeat that results in polyglutamine extended stretches in the encoded proteins. CAG repeat disorders generally show the phenomenon of anticipation, which is more often associated with paternal transmission. In this report, we describe a patient with infantile-onset spinocerebellar ataxia type 2 (~320 CAG repeat) who inherited the disease from his father (47 CAG repeats). We have summarized the clinical, neuroimaging, electroencephalographic (EEG), and molecular data of previous cases and attempt to highlight the most consistent findings. Our intent is to help treating clinicians to suspect this disorder and to offer timely genetic counseling for a currently potentially untreatable disorder.

Infantile onset alexander disease with normal head circumference: a genetically proven case report.

Alexander disease (AD) is an autosomal dominant leukodystrophy which predominantly affects infants and children. The infantile form comprises the most common form of AD. It presents before two years of age and characterized by macrocephaly, psychomotor regression, spasticity, pyramidal sign, ataxia and seizures. The diagnosis is based on magnetic resonance imaging (MRI) findings and confirmed by Glial fibrillary acidic protein (GFAP) gene molecular testing. We report an Indian case with normal head circumference.