Efficacy of hyaluronic acid binding assay in selecting motile spermatozoa with normal morphology at high magnification

Background  

The present study aimed to evaluate the efficacy of the hyaluronic acid (HA) binding assay in the selection of motile spermatozoa with normal morphology at high magnification (8400x).     

Outlook on sponge reproduction science in the last ten years: are we far from where we should be?

To comprehend the state of the art of sponge reproduction science (SRS), we quantified and analyzed the trends in SRS in the last decade, aiming to answer three questions: (i) Were there fewer SRS works presented during the last sponge conference? (ii) Did the number of SRS publications decline in the last decade? (iii) Does the number of abstracts at sponge conferences influence overall SRS publications? In addition, we checked whether the SRS community has answered Ereskovsky’s ‘five important questions’, enabling us to advance SRS enough to be considered as a fourth period of this scientific field. We found that SRS was less represented at the last sponge conference, despite an increase in the number of publications during the last decade. Moreover, the number of abstracts presented at sponge conferences contributed to a small portion (25%) of the published works in this area during the last decade. In addition, we found that two of the five Ereskovsky’s questions are still mostly not answered. Thus, we conclude that SRS is healthy and advancing steadily, especially in some subareas (e.g. developmental biology and life history). There are still much to advance, but this is still a strong field of biological science research.     

Trichodinidae in commercial fish in South America

Ciliates of the family Trichodinidae are protozoan parasites of importance for fish farming in South America, given that at high infestation levels, they cause significant mortality among farmed fish. Although data on economic losses due to parasitosis are not available for South America, mortality outbreaks correlated to trichodinids are very common in the tilapia production chain, especially in Brazil, the largest aquaculture chain in the country. In Brazil in the past, trichodinids were considered only as Trichodina sp. Today, they have been better studied and identified taxonomically in wild and farmed fish. However, in other countries in South America, trichodinids continue to be described only as Trichodina sp. This review presents the history of occurrences of trichodinids in fish of interest in South America, highlighting 15 new species that have been described in three genera in Brazil, along with information on parasite-host-environment relationships, diagnostic methods and treatments. The occurrence of parasitic ciliates must be correlated with farming conditions such as stress factors, water quality, seasonality, age and host immunity to elucidate the critical points of each production system. Furthermore, for tropical fish, studies on treatment against trichodinid species are needed to provide support for approval of antiparasitic medications for use in fish farming. However, it is recommended that the production sector use intensive production systems that are more sustainable, with biosafety protocols, to increase production and productivity.     

Cyclopaldic Acid,Seiridin, and Sphaeropsidin A as Fungal Phytotoxins,and Larvicidal and Biting Deterrents against Aedes aegypti (Diptera: Culicidae): Structure?Activity Relationships

Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. From a preliminary screening of fungal phytotoxins, cyclopaldic acid ( 1 ), seiridin ( 2 ), sphaeropsidin A ( 4 ), and papyracillic acid ( 5 ) were evaluated for their biting deterrent and larvicidal activities against Ae. aegypti L. Because compounds 1, 2, 4 , and 5 exhibited mosquito biting deterrent activities and 1 and 4 demonstrated larvicidal activities, further structure? activity relationship studies were initiated on these toxins. In biting‐deterrence bioassays, 1, 2, 4 , and 5 , 3,8‐didansylhydrazone of cyclopaldic acid, 1F , 5‐azidopentanoate of cyclopaldic acid A, 1G , the reduced derivative of cyclopaldic acid, 1 H , isoseiridin ( 3 ), 2′‐O‐acetylseiridin ( 2A ), 2′‐oxoseiridin ( 2C ), 6‐O‐acetylsphaeropsidin A ( 4A ), 8,14‐methylensphaeropsidin A methyl ester ( 4B ), and sphaeropsidin B ( 4C ) showed activities higher than the solvent control. Sphaeropsidin B ( 4C ) was the most active compound followed by 2A , while the other compounds were less active. Biting‐deterrence activity of compound 4C was statistically similar to DEET. In the larvicidal screening bioassays, only compounds 1 and 4 demonstrated larvicidal activities. Based on LD₅₀ values, compound 4 (LD₅₀ 36.8 ppm) was significantly more active than compound 1 (LD₅₀ 58.2 ppm). However, the activity of these compounds was significantly lower than permethrin.     

Role of multiple drug resistance protein 1 in neutral but not acidic glycosphingolipid biosynthesis

Transfection studies have implicated the multiple drug resistance pump, MDR1, as a glucosyl ceramide translocase within the Golgi complex (Lala, P., Ito, S., and Lingwood, C. A. (2000) J. Biol. Chem. 275, 6246-6251). We now show that MDR1 inhibitors, cyclosporin A or ketoconazole, inhibit neutral glycosphingolipid biosynthesis in 11 of 12 cell lines tested. The exception, HeLa cells, do not express MDR1. Microsomal lactosyl ceramide and globotriaosyl ceramide synthesis from endogenous or exogenously added liposomal glucosyl ceramide was inhibited by cyclosporin A, consistent with a direct role for MDR1/glucosyl ceramide translocase activity in their synthesis. In contrast, cellular ganglioside synthesis in the same cells, was unaffected by MDR1 inhibition, suggesting neutral and acid glycosphingolipids are synthesized from distinct precursor glycosphingolipid pools. Metabolic labeling in wild type and knock-out (MDR1a, 1b, MRP1) mouse fibroblasts showed the same loss of neutral glycosphingolipid (glucosyl ceramide, lactosyl ceramide) but not ganglioside (GM3) synthesis, confirming the proposed role for MDR1 translocase activity. Cryo-immunoelectron microscopy showed MDR1 was predominantly intracellular, largely in rab6-containing Golgi vesicles and Golgi cisternae, the site of glycosphingolipid synthesis. These studies identify MDR1 as the major glucosyl ceramide flippase required for neutral glycosphingolipid anabolism and demonstrate a previously unappreciated dichotomy between neutral and acid glycosphingolipid synthesis.     

Volume-regulated Cl- channels in human pleural mesothelioma cells

A novel xyloglucan-specific endo-β-1,4-glucanase (XEG), xyloglucanase, with a molecular mass of 80 kDa and a pI of 4.8, was isolated from the fungus Geotrichum sp. M128. It was found to be an endoglucanase active toward xyloglucan and not active toward carboxymethylcellulose, Avicel, or barley 1,3-1,4-β-glucan. Analysis of the precise substrate specificity using various xyloglucan oligosaccharide structures revealed that XEG has at least four subsites (−2 to +2) and specifically recognizes xylose branching at the +1 and +2 sites. The full-length cDNA encoding XEG was cloned and sequenced. It consists of a 2436-bp open reading frame encoding a 776-amino acid protein. From its deduced amino acid sequence, XEG can be classified as a family 74 glycosyl hydrolase. The cDNA encoding XEG was then expressed in Escherichia coli, and enzymatically active recombinant XEG was obtained.     

The effects of beta acids from hops (Humulus lupulus) on mortality of Varroa destructor (Acari: Varroidae)

Hop (Humulus lupulus L.) beta acids (HBA) were tested for miticidal effects on varroa destructor Anderson and Trueman, a parasitic mite of the honey bee (Apis mellifera L.). When varroa were placed on bees that had topical applications of 1?% HBA, there was 100?% mite mortality. Bee mortality was unaffected. Cardboard strips saturated with HBA and placed in colonies resulted in mite drop that was significantly greater than in untreated hives. HBA was detected on about 60?% of the bees in colonies during the first 48?h after application. Mite drop in colonies lasted for about 7?days with the highest drop occurring in the first 2–3?days after treatment. There was a reduction in the percentages of bees with HBA and in the amounts on their bodies after 7?days. Bee and queen mortality in the colonies were not affected by HBA treatments. When cardboard strips saturated with HBA were put in packages of bees, more than 90?% of the mites were killed without an increase in bee mortality. HBA might have potential to control varroa when establishing colonies from packages or during broodless periods.     

Heterologous expression in Escherichia coli of Neurospora crassa neutral trehalase as an active enzyme

Neutral trehalase from Neurospora crassa was expressed in Escherichia coli as a polypeptide of 84 kDa in agreement with the theoretical size calculated from the corresponding cDNA. The recombinant neutral trehalase, purified by affinity chromatography exhibited a specific activity of 80–150 mU/mg protein. Optima of pH and temperature were 7.0 and 30 °C, respectively. The enzyme was absolutely specific for trehalose, and was quite sensitive to incubation at 40 °C. The recombinant enzyme was totally dependent on calcium, and was inhibited by ATP, copper, silver, aluminium and cobalt. K_M was 42 mM, and V_max was 30.6 nmol of glucose/min. The recombinant protein was phosphorylated by cAMP-dependent protein kinase, but not significantly activated. Immunoblotting with polyclonal antiserum prepared against the recombinant protein showed that neutral trehalase protein levels increased during exponential phase of N. crassa growth and dropped at the stationary phase. This is the first report of a neutral trehalase produced in E. coli with similar biochemical properties described for fungi native neutral trehalases, including calcium-dependence.     

Association between APOC1 Polymorphism and Alzheimer’s Disease: A Case-Control Study and Meta-Analysis

Background

Previous association studies examining the relationship between the APOC1 polymorphism and susceptibility to Alzheimer’s disease (AD) have shown conflicting results, and it is not clear if an APOC1 variant acts as a genetic risk factor in AD etiology across multiple populations.

Methods

To confirm the risk association between APOC1 and AD, we designed a case-control study and also performed a meta-analysis of previously published studies.

Results

Seventy-nine patients with AD and one hundred fifty-six unrelated controls were included in case-control study. No association was found between the variation of APOC1 and AD in stage 1 of our study. However, our meta-analysis pooled a total of 2092 AD patients and 2685 controls. The APOC1 rs11568822 polymorphism was associated with increased AD risk in Caucasians, Asians and Caribbean Hispanics, but not in African Americans. APOE ε4 carriers harboring the APOC1 insertion allele, were more prevalent in AD patients than controls (χ² = 119.46, OR = 2.79, 95% CI = 2.31–3.36, P<0.01).

Conclusions

The APOC1 insertion allele, in combination with APOE ε4, likely serves as a potential risk factor for developing AD.     

Protein tyrosine phosphatases regulate arachidonic acid release, StAR induction and steroidogenesis acting on a hormone-dependent arachidonic acid-preferring acyl-CoA synthetase

The activation of the rate-limiting step in steroid biosynthesis, that is the transport of cholesterol into the mitochondria, is dependent on PKA-mediated events triggered by hormones like ACTH and LH. Two of such events are the protein tyrosine dephosphorylation mediated by protein tyrosine phosphatases (PTPs) and the release of arachidonic acid (AA) mediated by two enzymes, ACS4 (acyl-CoA synthetase 4) and Acot2 (mitochondrial thioesterase). ACTH and LH regulate the activity of PTPs and Acot2 and promote the induction of ACS4. Here we analyzed the involvement of PTPs on the expression of ACS4. We found that two PTP inhibitors, acting through different mechanisms, are both able to abrogate the hormonal effect on ACS4 induction. PTP inhibitors also reduce the effect of cAMP on steroidogenesis and on the level of StAR protein, which facilitates the access of cholesterol into the mitochondria. Moreover, our results indicate that exogenous AA is able to overcome the inhibition produced by PTP inhibitors on StAR protein level and steroidogenesis. Then, here we describe a link between PTP activity and AA release, since ACS4 induction is under the control of PTP activity, being a key event for AA release, StAR induction and steroidogenesis.