Assessment of imidacloprid induced genotoxicity in Pethia conchonius (Rosy barb), a common freshwater fish of India.

Imidacloprid is one of the highly efficient, globally used neonicotinoid groups of insecticides. The indiscriminate use of imidacloprid is contaminating large water bodies affecting not only the target organisms but also non-target organisms including fish. The present study aimed to assess the extent of nuclear DNA damage by imidacloprid in Pethia conchonius a freshwater fish in India using comet and micronucleus assays. The LC50 value of imidacloprid was estimated to be 227.33 mg L-1. Based on the LC50-96 h value, three sub-lethal concentrations of imidacloprid, SLC I -18.94 mg L-1, SLC II -28.41 mg L-1 and SLC III -56.83 mg L-1 were used to detect its genotoxic effect at DNA and cellular level. The imidacloprid exposed fishes exhibited higher DNA damage and nuclear abnormalities (p < 0.05) than the control. The %head DNA, %tail DNA, tail length and the frequency of micronuclei with other nuclear abnormalities like blebbed and notched nuclei were significantly higher than the control in a time and concentration-dependent manner. The DNA damage parameters such as %head DNA (29.107 ± 1.843), %tail DNA (70.893 ± 1.843), tail length (361.431 ± 8.455) micronucleus (1.300 ± 0.019), notched (0.844 ± 0.011) and blebbed (0.811 ± 0.011) nuclei were found to be highest for SLC III (56.83 mg L-1) at 96 h. The findings indicate that IMI is highly genotoxic in fish and other vertebrates leading to mutagenic/clastogenic effects. The study will be helpful in optimization of the imidacloprid use.

Glial Draper Rescues Aß Toxicity in a Drosophila Model of Alzheimer's Disease.

Pathological hallmarks of Alzheimer's disease (AD) include amyloid-ß (Aß) plaques, neurofibrillary tangles, and reactive gliosis. Glial cells offer protection against AD by engulfing extracellular Aß peptides, but the repertoire of molecules required for glial recognition and destruction of Aß are still unclear. Here, we show that the highly conserved glial engulfment receptor Draper/MEGF10 provides neuroprotection in an AD model of Drosophila (both sexes). Neuronal expression of human Aß42arc in adult flies results in robust Aß accumulation, neurodegeneration, locomotor dysfunction, and reduced lifespan. Notably, all of these phenotypes are more severe in draper mutant animals, whereas enhanced expression of glial Draper reverses Aß accumulation, as well as behavioral phenotypes. We also show that the signal transducer and activator of transcription (Stat92E), c-Jun N-terminal kinase (JNK)/AP-1 signaling, and expression of matrix metalloproteinase-1 (Mmp1) are activated downstream of Draper in glia in response to Aß42arc exposure. Furthermore, Aß42-induced upregulation of the phagolysosomal markers Atg8 and p62 was notably reduced in draper mutant flies. Based on our findings, we propose that glia clear neurotoxic Aß peptides in the AD model Drosophila brain through a Draper/STAT92E/JNK cascade that may be coupled to protein degradation pathways such as autophagy or more traditional phagolysosomal destruction methods.SIGNIFICANCE STATEMENT Alzheimer's disease (AD) and similar dementias are common incurable neurodegenerative disorders in the aging population. As the primary immune responders in the brain, glial cells are implicated as key players in the onset and progression of AD and related disorders. Here we show that the glial engulfment receptor Draper is protective in a Drosophila model of AD, reducing levels of amyloid ß (Aß) peptides, reversing locomotor defects, and extending lifespan. We further show that protein degradation pathways are induced downstream of Draper in AD model flies, supporting a model in which glia engulf and destroy Aß peptides to reduce amyloid-associated toxicity.

A novel Drosophila injury model reveals severed axons are cleared through a Draper/MMP-1 signaling cascade.

Neural injury triggers swift responses from glia, including glial migration and phagocytic clearance of damaged neurons. The transcriptional programs governing these complex innate glial immune responses are still unclear. Here, we describe a novel injury assay in adult Drosophila that elicits widespread glial responses in the ventral nerve cord (VNC). We profiled injury-induced changes in VNC gene expression by RNA sequencing (RNA-seq) and found that responsive genes fall into diverse signaling classes. One factor, matrix metalloproteinase-1 (MMP-1), is induced in Drosophila ensheathing glia responding to severed axons. Interestingly, glial induction of MMP-1 requires the highly conserved engulfment receptor Draper, as well as AP-1 and STAT92E. In MMP-1 depleted flies, glia do not properly infiltrate neuropil regions after axotomy and, as a consequence, fail to clear degenerating axonal debris. This work identifies Draper-dependent activation of MMP-1 as a novel cascade required for proper glial clearance of severed axons.

The Prevalence and Distribution of Neurodegenerative Compound-Producing Soil Streptomyces spp.

Recent work from our labs demonstrated that a metabolite(s) from the soil bacterium Streptomyces venezuelae caused dopaminergic neurodegeneration in Caenorhabditis elegans and human neuroblastoma cells. To evaluate the capacity for metabolite production by naturally occurring streptomycetes in Alabama soils, Streptomyces were isolated from soils under different land uses (agriculture, undeveloped, and urban). More isolates were obtained from agricultural than undeveloped soils; there was no significant difference in the number of isolates from urban soils. The genomic diversity of the isolates was extremely high, with only 112 of the 1509 isolates considered clones. A subset was examined for dopaminergic neurodegeneration in the previously established C. elegans model; 28.3% of the tested Streptomyces spp. caused dopaminergic neurons to degenerate. Notably, the Streptomyces spp. isolates from agricultural soils showed more individual neuron damage than isolates from undeveloped or urban soils. These results suggest a common environmental toxicant(s) within the Streptomyces genus that causes dopaminergic neurodegeneration. It could also provide a possible explanation for diseases such as Parkinson's disease (PD), which is widely accepted to have both genetic and environmental factors.

The role of seminal plasma for improved outcomes during in vitro fertilization treatment: review of the literature and meta-analysis.

BACKGROUND: There is a growing body of evidence surrounding the role played by seminal plasma in human implantation. Seminal fluid contains several proteins that interact with cervical and uterine epithelial cells inducing active immune tolerance. We sought to answer the study question: Does exposure to seminal plasma improve pregnancy outcomes in women undergoing IVF? METHODS: Randomized controlled trials (RCTs) were searched for via MEDLINE, EMBASE, the Cochrane Library, National Research Register, ISI conference proceedings, ISRCTN register and Meta-register, from 1966 to December 2013. Search terms included: 'seminal plasma', 'seminal fluid', 'sexual intercourse', 'IVF', 'ICSI', 'ART', 'pregnancy rate', 'implantation', 'embryo transfer' and 'live birth'. This analysis included all RCTs comparing the outcome of IVF treatments in patients exposed to seminal plasma near the time of oocyte pickup (OPU) or embryo transfer (ET) with that of placebo controls or controls with no exposure to seminal plasma. The main intervention was exposure to seminal plasma around the time of OPU or embryo transfer during an IVF cycle. The main outcomes were clinical pregnancy and live birth/ongoing pregnancy rates. Data were collected by two independent authors and statistically pooled via meta-analysis following intention to treat and per protocol principles using RevMan (v5.2.10). I(2) statistic, forest plots and chi-squared heterogeneity tests were used. RESULTS: In total 2204 patients were included in seven RCTs. Meta-analysis revealed a statistically significant improvement in clinical pregnancy rate (RR 1.23, 95% CI 1.06-1.42, P = 0.006) by intention to treat. Per protocol analysis also revealed a statistically significant improvement in clinical pregnancy rate (RR 1.24, 95% CI 1.07-1.43, P = 0.003). There was no statistically significant improvement seen for the outcome of ongoing pregnancy/live birth rate, but the available data were very limited. The methodology and quality of the studies were variable. CONCLUSIONS: There are significantly improved outcomes when women are exposed to seminal plasma around the time of ovum pick-up or embryo transfer, with statistical significance for clinical pregnancy but not for ongoing pregnancy/live birth rates being achieved. This meta-analysis is limited by the small number of studies of variable methodology. Further research is required to determine the effect on live birth rate; however, this meta-analysis indicates a significantly improved clinical pregnancy rate and a potential method for improving IVF outcomes.

Phenazine derivatives cause proteotoxicity and stress in C. elegans.

It is widely recognized that bacterial metabolites have toxic effects in animal systems. Phenazines are a common bacterial metabolite within the redox-active exotoxin class. These compounds have been shown to be toxic to the soil invertebrate Caenorhabditis elegans with the capability of causing oxidative stress and lethality. Here we report that chronic, low-level exposure to three separate phenazine molecules (phenazine-1-carboxylic acid, pyocyanin and 1-hydroxyphenazine) upregulated ER stress response and enhanced expression of a superoxide dismutase reporter in vivo. Exposure to these molecules also increased protein misfolding of polyglutamine and α-synuclein in the bodywall muscle cells of C. elegans. Exposure of worms to these phenazines caused additional sensitivity in dopamine neurons expressing wild-type α-synuclein, indicating a possible defect in protein homeostasis. The addition of an anti-oxidant failed to rescue the neurotoxic and protein aggregation phenotypes caused by these compounds. Thus, increased production of superoxide radicals that occurs in whole animals in response to these phenazines appears independent from the toxicity phenotype observed. Collectively, these data provide cause for further consideration of the neurodegenerative impact of phenazines.

RTCB-1 mediates neuroprotection via XBP-1 mRNA splicing in the unfolded protein response pathway.

Parkinson's disease (PD), the second most prevalent neurodegenerative disorder, is characterized by the degeneration of dopamine (DA) neurons and age-dependent formation of protein inclusions that contain the α-synuclein (α-syn) protein. RNA interference (RNAi) screening using Caenorhabditis elegans identified RTCB-1, an uncharacterized gene product, as one of several significant modifiers of α-syn protein misfolding. RTCB-1 is the worm ortholog of the human HSPC117 protein, a component of RNA trafficking granules in mammalian neurons. Here we show that RTCB-1 protects C. elegans DA neurons from age-dependent degeneration induced by human α-syn. Moreover, neuronal-specific RNAi depletion of rtcb-1 enhanced α-syn-induced degeneration. Similar results were obtained when worms were exposed to the DA neurotoxin 6-hydroxydopamine. HSPC117 has been characterized recently as an essential subunit of the human tRNA splicing ligase complex. tRNA ligases have alternative functions in RNA repair and nonconventional mRNA splicing events. For example, in yeast, unconventional splicing of HAC1, a transcription factor that controls the unfolded protein response (UPR), is mediated by a tRNA ligase. In C. elegans, we demonstrate that RTCB-1 is necessary for xbp-1 (worm homolog of HAC1) mRNA splicing. Moreover, using a RNA ligase-dead mutant, we determine that the ligase activity of worm RTCB-1 is required for its neuroprotective role, which, in turn, is mediated through XBP-1 in the UPR pathway. Collectively, these studies highlight the mechanistic intersection of RNA processing and proteostasis in mediating neuroprotection.

Identification of novel ATP13A2 interactors and their role in α-synuclein misfolding and toxicity.

Lysosomes are responsible for degradation and recycling of bulky cell material, including accumulated misfolded proteins and dysfunctional organelles. Increasing evidence implicates lysosomal dysfunction in several neurodegenerative disorders, including Parkinson's disease and related synucleinopathies, which are characterized by the accumulation of α-synuclein (α-syn) in Lewy bodies. Studies of lysosomal proteins linked to neurodegenerative disorders present an opportunity to uncover specific molecular mechanisms and pathways that contribute to neurodegeneration. Loss-of-function mutations in a lysosomal protein, ATP13A2 (PARK9), cause Kufor-Rakeb syndrome that is characterized by early-onset parkinsonism, pyramidal degeneration and dementia. While loss of ATP13A2 function plays a role in α-syn misfolding and toxicity, the normal function of ATP13A2 in the brain remains largely unknown. Here, we performed a screen to identify ATP13A2 interacting partners, as a first step toward elucidating its function. Utilizing a split-ubiquitin membrane yeast two-hybrid system that was developed to identify interacting partners of full-length integral membrane proteins, we identified 43 novel interactors that primarily implicate ATP13A2 in cellular processes such as endoplasmic reticulum (ER) translocation, ER-to-Golgi trafficking and vesicular transport and fusion. We showed that a subset of these interactors modified α-syn aggregation and α-syn-mediated degeneration of dopaminergic neurons in Caenorhabditis elegans, further suggesting that ATP13A2 and α-syn are functionally linked in neurodegeneration. These results implicate ATP13A2 in vesicular trafficking and provide a platform for further studies of ATP13A2 in neurodegeneration.

Unexplained infertility: an update and review of practice.

Of the couples unable to conceive without any identifiable cause, 30% are defined as having unexplained infertility. Management depends on duration of infertility and age of female partner. This review describes and comments on the definition and evidence for the management of unexplained infertility. A literature search was conducted in EMBASE, Medline, Ovid and Cochrane Database of Systematic reviews using the terms 'infertility', 'unexplained infertility', 'idiopathic infertility', 'definition of infertility', 'treatment options', 'intrauterine insemination', 'ovulation induction', 'Fallopian tube sperm', 'GIFT' and 'IVF'. There is no uniform definition for unexplained infertility. This varies in the literature depending on the duration of infertility and the age of the female partner. The treatment of unexplained infertility is empirical and many different regimens have been used. Among these are expectant management, ovulation stimulation with clomiphene citrate, gonadotrophins and aromatase inhibitors, Fallopian tube sperm perfusion, tubal flushing, intrauterine insemination, gamete intra-Fallopian transfer and IVF. The standard protocol is to progress from low-technology to high-technology treatment options. On the best available evidence, an algorithm for management is suggested. There is a definite need for multicentre randomized controlled trials to identify the best treatment option in unexplained infertility using a standard definition.

Inhibitors of LRRK2 kinase attenuate neurodegeneration and Parkinson-like phenotypes in Caenorhabditis elegans and Drosophila Parkinson's disease models.

Mutations in leucine-rich repeat kinase 2 (LRRK2) have been identified as a genetic cause of familial Parkinson's disease (PD) and have also been found in the more common sporadic form of PD, thus positioning LRRK2 as important in the pathogenesis of PD. Biochemical studies of the disease-causing mutants of LRRK2 implicates an enhancement of kinase activity as the basis of neuronal toxicity and thus possibly the pathogenesis of PD due to LRRK2 mutations. Previously, a chemical library screen identified inhibitors of LRRK2 kinase activity. Here, two of these inhibitors, GW5074 and sorafenib, are shown to protect against G2019S LRRK2-induced neurodegeneration in vivo in Caenorhabditis elegans and in Drosophila. These findings indicate that increased kinase activity of LRRK2 is neurotoxic and that inhibition of LRRK2 activity can have a disease-modifying effect. This suggests that inhibition of LRRK2 holds promise as a treatment for PD.

p27Kip1 inhibits cyclin D-cyclin-dependent kinase 4 by two independent modes.

Cell cycle progression is regulated by cyclin-dependent kinases (cdk's), which in turn are regulated by their interactions with stoichiometric inhibitors, such as p27(Kip1). Although p27 associates with cyclin D-cyclin-dependent kinase 4 (cdk4) constitutively, whether or not it inhibits this complex is dependent on the absence or presence of a specific tyrosine phosphorylation that converts p27 from a bound inhibitor to a bound noninhibitor under different growth conditions. This phosphorylation occurs within the 3-10 helix of p27 and may dislodge the helix from cdk4's active site to allow ATP binding. Here we show that the interaction of nonphosphorylated p27 with cdk4 also prevents the activating phosphorylation of the T-loop by cyclin H-cdk7, the cdk-activating kinase (CAK). Even though the cyclin H-cdk7 complex is present and active in contact-arrested cells, p27's association with cyclin D-cdk4 prevents T-loop phosphorylation. When p27 is tyrosine phosphorylated in proliferating cells or in vitro with the tyrosine Y kinase Abl, phosphorylation of cdk4 by cyclin H-cdk7 is permitted, even without dissociation of p27. This suggests that upon release from the contact-arrested state, a temporal order for the reactivation of inactive p27-cyclin D-cdk4 complexes must exist: p27 must be Y phosphorylated first, directly permitting cyclin H-cdk7 phosphorylation of residue T172 and the consequent restoration of kinase activity. The non-Y-phosphorylated p27-cyclin D-cdk4 complex could be phosphorylated by purified Csk1, a single-subunit CAK from fission yeast, but was still inactive due to p27's occlusion of the active site. Thus, the two modes by which p27 inhibits cyclin D-cdk4 are independent and may reinforce one another to inhibit kinase activity in contact-arrested cells, while maintaining a reservoir of preformed complex that can be activated rapidly upon cell cycle reentry.

Differential modification of p27Kip1 controls its cyclin D-cdk4 inhibitory activity.

Whether p27 is a cyclin D-cdk4/6 inhibitor or not is controversial, and how it might switch between these two modes is unknown. Arguing for a two-state mechanism, we show that p27 bound to cyclin D-cdk4 can be both inhibitory and noninhibitory, due to its differential-growth-state-dependent tyrosine phosphorylation. We found that p27 from proliferating cells was noninhibitory but that p27 from arrested cells was inhibitory, and the transition from a bound noninhibitor to a bound inhibitor was not due to an increase in p27 concentration. Rather, two tyrosine residues (Y88 and Y89) in p27's cdk interaction domain were phosphorylated preferentially in proliferating cells, which converted p27 to a noninhibitor. Concordantly, mutation of these sites rendered p27 resistant to phosphorylation and locked it into the bound-inhibitor mode in vivo and in vitro. Y88 was directly phosphorylated in vitro by the tyrosine kinase Abl, which converted p27 to a cdk4-bound noninhibitor. These data show that the growth-state-dependent tyrosine phosphorylation of p27 modulates its inhibitory activity in vivo.

A study on upper extremity cumulative trauma disorder in different unorganised sectors of West Bengal, India.

Cumulative trauma disorder (CTD) is a term used to describe a class of soft tissue injuries that result due to a number of occupational activities. These disorders commonly occur among workers who are engaged in highly repetitive jobs involving continuous hand exertion, vibration and localized mechanical pressure. In the present investigation, an attempt was made to evaluate the prevalence of CTD among workers associated with strenuous hand intensive jobs in unorganized sectors in India and to highlight the unsafe working conditions to which these workers have been exposed for several years. For this purpose, an experiment was performed on 25 male workers from each group. The groups were classified into meat cutters, typists, tailors, visual display terminal (VDT) operators & weavers. For the symptom survey, a questionnaire and checklist method was implemented. Along with these, a detailed time study was performed among the workers during different activities in the total work cycle. For this study a two-tail chi-square test of independence was applied to determine whether or not the feeling of discomfort had any significant association with the repetitiveness of the work. From the observations and analysis of the results, it was revealed that all the activities are repetitive, i.e. over 50% of the work cycle of each activity involved the respective main activity where similar kinds of motion patterns were performed. Therefore it can be concluded that high repetitiveness, prolonged work activity and remaining in static posture for a prolong period of time may be regarded as the causative factors in the occurrence of CTD.