Upregulation of Cysteine Protease Cathepsin X in the 6-Hydroxydopamine Model of Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by loss of midbrain dopaminergic neurons in the substantia nigra pars compacta (SNc). In vitro, a contribution to neuroinflammation and neurotoxicity has been shown for the lysosomal protease cathepsin X; however, its expression and its role in PD remain unknown. Therefore, the current study was designed to address the regional, cellular, and subcellular localization and activity of cathepsin X in hemi-parkinsonian rats with 6-hydroxydopamine (6-OHDA)-induced excitotoxicity in the unilateral medial forebrain bundle (MFB) lesion. We report for the first time that cathepsin X expression and activity are rapidly increased in the ipsilateral SNc after injection of 6-OHDA into the MFB reaching a maximum after 12 h but seem to stay strongly upregulated after 4 weeks after injection. At early time points of 6-OHDA injection into the MFB, the increased cathepsin X is localized in the lysosomes in the neuronal, predominantly tyrosine hydroxylase-positive dopaminergic cells. After 12 h of 6-OHDA induced lesion, only a few activated microglial cells are positive for cathepsin X whereas, in 4 weeks post-lesion accompanied with complete loss of dopaminergic neurons, there is persistent cathepsin X upregulation restricted to activated glia cells. Taken together, our results demonstrate that cathepsin X upregulation in the lesioned dopaminergic system may play a role as a pathogenic factor in PD. Moreover, inhibition of cathepsin X expression or activity may be useful in protecting the nigrostriatal dopaminergic projection in the PD.

NK cells shape pancreatic and oral tumor microenvironments; role in inhibition of tumor growth and metastasis

We have recently shown that natural killer (NK) cells select and differentiate cancer stem cells (CSCs)/undifferentiated tumors via secreted and membrane bound IFN-gamma (IFN-γ) and TNF-alpha (TNF-α), preventing tumor growth and inducing remodeling of the tumor microenvironment. Since many conventional therapeutic strategies, including chemotherapy and radiotherapy remain fairly unsuccessful in treating CSCs/poorly differentiated tumors, there has been an increasing interest in NK cell-targeted immunotherapy for the treatment of aggressive tumors. In our recent studies, we used humanized-BLT (hu-BLT) mouse model with transplanted human bone marrow, liver and thymus to demonstrate the efficacy of adoptive transfer of ex vivo expanded, super-charged NK cells in selection and differentiation of stem-like tumors within the context of a fully reconstituted human immune system. Furthermore, we have demonstrated that CSCs differentiated with split-anergized NK cells prior to implantation in hu-BLT mice were not able to grow or metastasize. However, when NK cell-mediated tumor differentiation was blocked by the addition of antibodies to IFN-γ and TNF-α, tumors grew and metastasized. In this review, we present current advances in NK cell expansion and therapeutic delivery, and discuss the utility of allogeneic super-charged NK cells in treatment of cancer patients. In addition, NK suppression occurs not only at the stage of overt cancer, but also at the pre-neoplastic stage. Therefore, due to the indispensable role of NK cells in targeting CSCs/undifferentiated tumors and their role in differentiation of the tumors, NK cells should be placed high in the armamentarium of tumor immunotherapy.

Cysteine cathepsins B, X and K expression in peri-arteriolar glioblastoma stem cell niches

Glioblastoma (GBM) is the most lethal brain tumor also due to malignant and therapy-resistant GBM stem cells (GSCs) that are localized in protecting hypoxic GSC niches. Some members of the cysteine cathepsin family of proteases have been found to be upregulated in GBM. Cathepsin K gene expression is highly elevated in GBM tissue versus normal brain and it has been suggested to regulate GSC migration out of the niches. Here, we investigated the cellular distribution of cathepsins B, X and K in GBM tissue and whether these cathepsins are co-localized in GSC niches. Therefore, we determined expression of these cathepsins in serial paraffin sections of 14 human GBM samples and serial cryostat sections of two samples using immunohistochemistry and metabolic mapping of cathepsin activity using selective fluorogenic substrates. We detected cathepsins B, X and K in peri-arteriolar GSC niches in 9 out of 16 GBM samples, which were defined by co-expression of the GSC marker CD133, the niche marker stromal-derived factor-1α (SDF-1α) and smooth muscle actin as a marker for arterioles. The expression of cathepsin B and X was detected in stromal cells and cancer cells throughout the GBM sections, whereas cathepsin K expression was more restricted to arteriole-rich regions in the GBM sections. Metabolic mapping showed that cathepsin B, but not cathepsin K is active in GSC niches. On the basis of these findings, it is concluded that cathepsins B, X and K have distinct functions in GBM and that cathepsin K is the most likely GSC niche-related cathepsin of the three cathepsins investigated.

Multi-target-directed ligands for treating Alzheimer's disease: Butyrylcholinesterase inhibitors displaying antioxidant and neuroprotective activities

The limited clinical efficacy of current symptomatic treatment and minute effect on progression of Alzheimer's disease has shifted the research focus from single targets towards multi-target-directed ligands. Here, a potent selective inhibitor of human butyrylcholinesterase was used as the starting point to develop a new series of multifunctional ligands. A focused library of derivatives was designed and synthesised that showed both butyrylcholinesterase inhibition and good antioxidant activity as determined by the DPPH assay. The crystal structure of compound 11 in complex with butyrylcholinesterase revealed the molecular basis for its low nanomolar inhibition of butyrylcholinesterase (Ki = 1.09 ± 0.12 nM). In addition, compounds 8 and 11 show metal-chelating properties, and reduce the redox activity of chelated Cu²⁺ ions in a Cu-ascorbate redox system. Compounds 8 and 11 decrease intracellular levels of reactive oxygen species, and are not substrates of the active efflux transport system, as determined in Caco2 cells. Compound 11 also protects neuroblastoma SH-SY5Y cells from toxic Aβ_1-42 species. These data indicate that compounds 8 and 11 are promising multifunctional lead ligands for treatment of Alzheimer's disease.

Design, Synthesis, and Biological Evaluation of 1-Benzylamino-2-hydroxyalkyl Derivatives as New Potential Disease-Modifying Multifunctional Anti-Alzheimer's Agents

The multitarget approach is a promising paradigm in drug discovery, potentially leading to new treatment options for complex disorders, such as Alzheimer's disease. Herein, we present the discovery of a unique series of 1-benzylamino-2-hydroxyalkyl derivatives combining inhibitory activity against butyrylcholinesterase, β-secretase, β-amyloid, and tau protein aggregation, all related to mechanisms which underpin Alzheimer's disease. Notably, diphenylpropylamine derivative 10 showed balanced activity against both disease-modifying targets, inhibition of β-secretase (IC_{50  hBACE-1} = 41.60 μM), inhibition of amyloid β aggregation (IC_50 Aβ = 3.09 μM), inhibition of tau aggregation (55% at 10 μM); as well as against symptomatic targets, butyrylcholinesterase inhibition (IC_{50  hBuChE} = 7.22 μM). It might represent an encouraging starting point for development of multifunctional disease-modifying anti-Alzheimer's agents.

Natural killer cells target and differentiate cancer stem-like cells/undifferentiated tumors: strategies to optimize their growth and expansion for effective cancer immunotherapy

Natural killer (NK) cells are known to select and differentiate cancer stem-like cells/undifferentiated tumors via lysis, and secreted/membrane bound IFN-γ and TNF-α respectively, resulting in the control of tumor growth. Several in vivo mouse models including humanized-BLT mice have been used to study the biology and significance of NK cells in selection/differentiation of stem-like tumors within the context of a reconstituted human immune system. In addition, we discuss the evidence and significance of NK cell loss at the pre-neoplastic stage. Therefore, because of their indispensable role in targeting CSCs/undifferentiated tumors, NK-cells should be placed high in the armamentarium of tumor therapy.

Nanoparticle Based Delivery of Protease Inhibitors to Cancer Cells

Proteases are involved in a variety of processes associated with tumor development and progression. Because of their integral role in extracellular matrix and basal lamina degradation they play important roles in cancer cell migration, invasion, angiogenesis and metastasis. They are also involved in cancer cell signaling, the epithelial-mesenchymal transition, the antitumor immune response, cell de-differentiation and cancer stem cell remodeling. Their involvement in pro-tumorigenic processes makes them interesting targets for anticancer therapy. The most promising are matrix metalloproteases, cysteine cathepsins, the urokinase-type plasminogen activator system and proteasome; these constitute the focus of this review. Several inhibitors have been developed for reducing their activities that are in different phases of development, with some already in clinical use. However, systemic delivery of protease inhibitors can result in undesired reduction of proteolytic activity in normal tissues, leading to adverse effects and limited therapeutic efficacy. This caveat can be circumvented by nanoparticle delivery systems that direct protease inhibitors specifically to cancer cells. In this article we review the current state of nanoparticle delivery systems for delivering protease inhibitors to cancer cells.

Cysteine Proteinases and Their Inhibitors in Extracellular Fluids: Markers for Diagnosis and Prognosis in Cancer

Cathepsins B, H and L have been shown to participate in processes of tumor growth, vascularization, invasion and metastasis. Their levels in tumor tissue extracts can provide useful clinical information to predict disease-free and overall survival in breast, lung, colorectal, brain and head and neck cancer patients. Recently we have found that both cysteine cathepsins and their endogenous protein inhibitors stefins and cystatin C can also predict prognosis when measured extracellularly. In melanoma and colorectal cancer patients high serum levels of cathepsins B and H correlated with shorter survival. Similarly, increased extracellular levels of stefins A and B and cystatin C correlated significantly with high risk of adverse outcome in cancer patients. However, the cathepsin B/cystatin C complex was found to be less abundant in sera of patients with malignant tumors than in those with benign diseases or in healthy controls, suggesting an imbalance between the enzyme and its inhibitor in cancer patients.

Cathepsin B inhibitors: Further exploration of the nitroxoline core

Human cathepsin B is a cysteine protease with many house-keeping functions, such as intracellular proteolysis within lysosomes. Its increased activity and expression have been strongly associated with many pathological processes, including cancers. We present here the design and synthesis of novel derivatives of nitroxoline as inhibitors of cathepsin B. These were prepared either by omitting the pyridine part, or by modifying positions 2, 7, and 8 of nitroxoline. All compounds were evaluated for their ability to inhibit endopeptidase and exopeptidase activities of cathepsin B. For the most promising inhibitors, the ability to reduce extracellular and intracellular collagen IV degradation was determined, followed by their evaluation in cell-based in vitro models of tumor invasion. The presented data show that we have further defined the structural requirements for cathepsin B inhibition by nitroxoline derivatives and provided additional knowledge that could lead to non-peptidic compounds with usefulness against tumor progression.

Serum Cathepsin H as a Potential Prognostic Marker in Patients with Colorectal Cancer

Cathepsin H is a lysosomal cysteine protease that may participate in tumor progression. In order to evaluate its potential as a prognostic marker, its protein levels were measured by ELISA in preoperative sera from 324 patients with colorectal cancer. The level of cathepsin H was significantly increased in patient sera, the median level was 8.4 ng/mL versus 2.1 ng/mL in 90 healthy blood donors (p<0.0001). A weak association of cathepsin H levels was found with patient age (p=0.02) but not with Dukes’ stage, sex, or the level of carcinoembryonic antigen (CEA). In survival analysis a significant difference was found between the group of patients with low cathepsin H (first tertile) who had a poor prognosis and the remaining patients (p=0.03). The risk of patients was further stratified when cathepsin H levels were combined with CEA. Patients with high CEA and low cathepsin H had the highest risk of death with a hazard ratio of 2.72 (95% CI 1.73–4.28), p<.0001. Our results show that the prognostic information of cathepsin H differs from that of the related cathepsins B and L and suggest different roles during the progression of malignant disease.

Levels of Cathepsins S and H in Pleural Fluids of Inflammatory and Neoplastic Origin

Cathepsins S and H are present in immune cells and tissues and may play a role in the activation of an adoptive immune response. Our goal was to assess their protein levels in pleural fluids from 82 patients who underwent thoracentesis or thoracoscopy for therapeutic or diagnostic reasons and to relate them to an inflammatory, neoplastic or hemodynamic origin. Pleural effusions were also analyzed for a panel of 13 inflammatory or proliferative markers to test possible links to a nonspecific host reaction. Increased levels of cathepsin S were found in parainflammatory and cancer-related effusions compared to transudates. Cathepsin H levels were elevated only in parainflammatory effusions, whereas the levels in cancer-related effusions were comparable to transudates. Cathepsin S values significantly correlated with LDH, alpha-1-AT, VEGF, sICAM, sVCAM, MPO, uPA, MMP-9/TIMP-1, IL-8 and MCP-1, but not with CRP, IL-10 or cathepsin H. In contrast to cathepsin S, cathepsin H values did not correlate with markers of inflammation, indicating a specific role for cathepsin H in the pleural host response. In conclusion, the estimation of cathepsin S and cathepsin H may help to distinguish between effusions of different etiology.

Cathepsin B, Cathepsin H, Cathepsin X and Cystatin C in Sera of Patients with Early-Stage and Inflammatory Breast Cancer

Numerous studies have linked cathepsins and their inhibitor cystatin C to tumor invasion and metastasis. We examined whether cathepsin B, cathepsin H, cathepsin X and cystatin C could be detected in sera from women with early-stage or inflammatory breast cancer and whether they correlated with clinicopathological characteristics. Preoperative serum was obtained from 176 patients with early-stage breast cancer (tumor size <5 cm, negative lymph nodes) and 31 patients with inflammatory breast cancer. Cathepsin and cystatin C levels were measured by ELISA. The patient and tumor characteristics under study were age at diagnosis, menopausal status, tumor size, tumor grade, and steroid hormone receptor status. Serum cathepsin B levels were significantly lower in patients with poorly differentiated tumors. High cystatin C levels were associated with tumor size, postmenopausal status and patient age. Interestingly, significantly lower levels of cathepsin X and H were found in patients with inflammatory breast cancer, a trend also observed for cathepsin B and cystatin C. In conclusion, our results show a limited association of cathepsins B, H, X and cystatin C with established prognostic parameters. These data are promising and encourage future analysis of the clinical outcome of our patients in order to examine the potential prognostic value of these biomarkers. Further, this study indicates a role for cathepsin X and H in inflammatory breast cancer.

Increased Plasma Cathepsin S at the Time of Percutaneous Transluminal Angioplasty is Associated with 6-Months’ Restenosis of the Femoropopliteal Artery

Background: We tested the hypothesis that increased levels of cathepsin S and decreased levels of cystatin C in plasma at the time of percutaneous transluminal angioplasty (PTA) are associated with the occurrence of 6-months’ restenosis of the femoropopliteal artery (FPA). Methods: 20 patients with restenosis and 24 matched patients with patent FPA after a 6-months follow-up were in - cluded in this study. They all exhibited disabling claudication or critical limb ischemia and had undergone technically successful PTA. They were all receiving statins and ACE in hi - bitors (or angiotensin II receptor antagonist) before the PTA and the therapy did not change throughout the observational period. Plasma concentrations of C-reactive protein were < 10 mg/L and of creatinine within the reference range at the time of the PTA. Plasma concentration and activity of cathepsin S, together with its potent inhibitor cystatin C, were measured the day before and the day after the PTA. Results: The increased plasma concentration and activity of cathepsin S at the time of PTA was associated with the occurrence of 6-months’ restenosis of FPA, independently of established risk factors (lesion complexity, infrapopliteal run-off vessels, type of PTA, age, gender, smoking, diabetes, lipids) and of cystatin C. Plasma cystatin C concentration was not associated with restenosis and did not correlate with cathepsin S activity and concentration in the plasma. Conclusion: Increased level of plasma cathepsin S at the time of PTA is associated with 6-months’ restenosis of PTA, independently of established risk factors.

Cystatin F Affects Natural Killer Cell Cytotoxicity

Cystatin F is a cysteine peptidase inhibitor which, unlike other cystatin family members, is targeted to endosomal/lysosomal compartments. It is synthesized as an inactive disulfide-linked dimer which is then converted to an active monomer by proteolytic cleavage of 15 N-terminal residues. Cystatin F has been suggested to regulate the cytotoxicity of natural killer (NK) cells by inhibiting the major granzyme convertases, cathepsins C and H. To test this hypothesis, we prepared variants of cystatin F and analyzed their uptake, subcellular trafficking, and peptidase inhibition, as well as their impact on the cytotoxicity of NK-92 cells and primary NK cells. The N-glycosylation pattern is responsible for the secretion, uptake, and subcellular sorting of cystatin F in HeLa and Hek293 cells, whereas the legumain binding site had no effect on these processes. Active, N-terminally truncated, monomeric cystatin F can also be internalized by recipient cells and targeted to endo/lysosomes, affecting also cells lacking the activating peptidase. Cystatin F mutants capable of cell internalization and trafficking through the endo/lysosomal pathway significantly decreased cathepsin C and H activities, both in situ, following transfection and in trans, using conditioned media. Further, incubation of IL-2 stimulated NK-92 and primary NK cells with full-length and N-terminally truncated cystatin F mutants led to suppression of their granule-mediated cytotoxicity. This effect was most significant with the N-terminally truncated mutants. These results suggest that cystatin F can be an important mediator within tumor microenvironment affecting the cytotoxicity of NK cells and consequently antitumor immune response.

Aqueous Extracts of Wild Mushrooms Show Antimicrobial and Antiadhesion Activities against Bacteria and Fungi

Mushrooms represent promising sources of novel bioactive compounds and can be applied as innovative strategies to control microbial contamination and infection via the food chain. We characterized aqueous extracts from 21 wild basidiomycete mushrooms and the cultivated oyster mushroom, Pleurotus ostreatus, as putative sources of antimicrobial and antiadhesive compounds. Broth microdilutions and adhesion to a polystyrene surface were evaluated on Gram-positive and Gram-negative bacteria and on fungi. The aqueous extracts tested showed antimicrobial and antiadhesive activities against these microorganisms. Biochemical analyses of the P. ostreatus extract indicated the involvement of several compounds with different molecular masses. Copyright © 2017 John Wiley & Sons, Ltd.

Identification and characterization of the novel reversible and selective cathepsin X inhibitors

Cathepsin X is a cysteine peptidase involved in the progression of cancer and neurodegenerative diseases. Targeting this enzyme with selective inhibitors opens a new possibility for intervention in several therapeutic areas. In this study triazole-based reversible and selective inhibitors of cathepsin X have been identified. Their selectivity and binding is enhanced when the 2,3-dihydrobenzo[b][1,4]dioxine moiety is present as the R¹ substituent. Of a series of selected triazole-benzodioxine derivatives, compound 22 is the most potent inhibitor of cathepsin X carboxypeptidase activity (K_i = 2.45 ± 0.05 μM) with at least 100-fold greater selectivity in comparison to cathepsin B or other related cysteine peptidases. Compound 22 is not cytotoxic to prostate cancer cells PC-3 or pheochromocytoma PC-12 cells at concentrations up to 10 μM. It significantly inhibits the migration of tumor cells and increases the outgrowth of neurites, both processes being under the control of cathepsin X carboxypeptidase activity. Compound 22 and other characterized triazole-based inhibitors thus possess a great potential for further development resulting in several in vivo applications.

Addition of 2-(ethylamino)acetonitrile group to nitroxoline results in significantly improved anti-tumor activity in vitro and in vivo

Lysosomal cysteine peptidase cathepsin B, involved in multiple processes associated with tumor progression, is validated as a target for anti-cancer therapy. Nitroxoline, a known antimicrobial agent, is a potent and selective inhibitor of cathepsin B, hence reducing tumor progression in vitro and in vivo. In order to further improve its anti-cancer properties we developed a number of derivatives using structure-based chemical synthesis. Of these, the 7-aminomethylated derivative (compound 17) exhibited significantly improved kinetic properties over nitroxoline, inhibiting cathepsin B endopeptidase activity selectively. In the present study, we have evaluated its anti-cancer properties. It was more effective than nitroxoline in reducing tumor cell invasion and migration, as determined in vitro on two-dimensional cell models and tumor spheroids, under either endpoint or real time conditions. Moreover, it exhibited improved action over nitroxoline in impairing tumor growth in vivo in LPB mouse fibrosarcoma tumors in C57Bl/6 mice. Taken together, the addition of a 2-(ethylamino)acetonitrile group to nitroxoline at position 7 significantly improves its pharmacological characteristics and its potential for use as an anti-cancer drug.

Cystatins, cysteine peptidase inhibitors, as regulators of immune cell cytotoxicity

Cystatins comprise a superfamily of evolutionarily related proteins, present in all living organisms, from protozoa to mammals. They act as inhibitors of cysteine peptidases although they can also function independently of their inhibitory function. Cysteine cathepsins are implicated in various physiological and pathological processes. In the immune response they are involved in antigen processing and presentation, the cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL), migration and adhesion of immune cells, cytokine and growth factor regulation and toll-like receptor signalling. Cystatins are probably involved in the regulation of all these processes; importantly, cystatin F has a crucial role in the regulation of immune cell cytotoxicity. NK cells and CTLs exploit the granzyme/perforin pathway for target cell killing, with perforin and granzymes as crucial effector molecules. Granzymes are synthesized as inactive pro-granzymes and need to be proteolytically activated by cathepsins C and H. Cystatin F is the main regulator of the activity of cathepsins C and H in cytotoxic cells and, consequently, regulates their cytotoxicity. The role of cystatins and cysteine cathepsins in the immune response is presented, with emphasis on their role in the regulation of cytotoxicity of NK cells and CTLs.

Trypsin-specific Inhibitors from the Macrolepiota procera, Armillaria mellea and Amanita phalloides wild mushrooms

Wild growing mushrooms are a rich source of novel proteins with unique features. We have isolated and characterized trypsin inhibitors from two edible mushrooms, the honey fungus (Armillaria mellea) and the parasol mushroom (Macrolepiota procera), and from the poisonous death cap (Amanita phalloides). The trypsin inhibitors isolated: armespin, macrospin and amphaspin, have similar molecular masses, acidic isoelectric points and are not N-glycosylated. They are very strong trypsin inhibitors and weak chymotrypsin inhibitors. They are resistant to exposure to high temperatures and withstand extreme pH values. These exceptional characteristics are advantageous for their potential use in biotechnology, agriculture and medicine.

Medicinal Properties of the Genus Clitocybe and of Lectins from the Clouded Funnel Cap Mushroom, C. nebularis (Agaricomycetes): A Review

Current knowledge of the medicinal properties of Basidiomycetes mushroom species of the genus Clitocybe and of the biological activity of C. nebularis fruiting bodies is reviewed. The main focus is the therapeutic potential of lectins from C. nebularis. Species of the genus Clitocybe, including C. nebularis, have not been traditionally considered as medicinal mushrooms; however, recent studies have demonstrated their antitumor, immunomodulatory, and antioxidative properties, their antimicrobial (antiviral, antibacterial, and antifungal) activities against various bacteria and fungi, as well as their potential use in therapy for alcoholism and as psychotropic agents. These activities have been shown to be due to various compounds, either isolated or in extracts, mainly polysaccharides but also phenols, ribonucleosides, and proteins. These include laccase, protease inhibitors, and lectins. C. nebularis has been shown to be rich in a variety of lectins and isolectins with distinct carbohydrate-binding specificities, showing versatile biological activities. They exhibit immunostimulatory and adhesion-/phagocytosis-promoting properties, as well as toxicity in various invertebrates. Mushroom species of the genus Clitocybe, including C. nebularis, thus constitute a valuable source of compounds showing diverse biological activities with a broad potential for applications in biomedicine or biotechnology. On the basis of such evidence reviewed here, we propose that C. nebularis and other Clitocybe species can be considered to be medicinal mushrooms.

The influence of macro- and microelements in seminal plasma on diluted boar sperm quality

Background

Growing evidence indicates that macro- and microelements in the seminal plasma of humans and various domestic animals are of great importance due to their roles in sperm metabolism, function, survival and oxidative stress. In the present study, we therefore determined the concentrations of macro- and microelements in fresh boar seminal plasma and their relation to sperm quality parameters after 3 days of liquid storage was assessed. Twenty ejaculates from eight boars were collected, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability, mitochondrial membrane potential and DNA fragmentation were determined on the day of collection (day 0) and day 3 (72 h) of storage at 15–17 °C. Seminal plasma was separated and the concentrations of macroelements (Na, K, Ca, and Mg) and microelements (Cu, Fe, Zn and Se) were determined.

Results

After 3 days of storage Se levels correlated significantly with sperm motility, progressive motility and morphology, all of which are routinely used for semen evaluation. On day 3, Se levels also correlated with tail membrane integrity, viability and intact DNA (P < 0.05). The correlation coefficients showed that mitochondrial function was better preserved at higher levels of Zn, while higher levels of Cu decreased mitochondrial function, but led to the better preservation of DNA. It was also evident that higher levels of Fe were associated with higher proportions of live spermatozoa and of spermatozoa with normal morphology after 3 days of storage (P < 0.05), while higher levels of Ca and Mg in fresh seminal plasma were associated with lower percentages of progressive motile spermatozoa and with a decreased proportion of spermatozoa with intact DNA (P < 0.05). Multivariate analysis including microelements showed that Se significantly affected sperm quality parameters, mentioned above, after 3 days of storage.

Conclusions

Macro- and microelements were associated with boar sperm quality and may be important biomarkers of boar sperm quality after liquid storage. Our results demonstrate that the evaluation of Se in fresh boar seminal plasma can serve as an additional tool in predicting sperm quality after storage.

Development of an in-vivo active reversible butyrylcholinesterase inhibitor

Alzheimer’s disease (AD) is characterized by severe basal forebrain cholinergic deficit, which results in progressive and chronic deterioration of memory and cognitive functions. Similar to acetylcholinesterase, butyrylcholinesterase (BChE) contributes to the termination of cholinergic neurotransmission. Its enzymatic activity increases with the disease progression, thus classifying BChE as a viable therapeutic target in advanced AD. Potent, selective and reversible human BChE inhibitors were developed. The solved crystal structure of human BChE in complex with the most potent inhibitor reveals its binding mode and provides the molecular basis of its low nanomolar potency. Additionally, this compound is noncytotoxic and has neuroprotective properties. Furthermore, this inhibitor moderately crosses the blood-brain barrier and improves memory, cognitive functions and learning abilities of mice in a model of the cholinergic deficit that characterizes AD, without producing acute cholinergic adverse effects. Our study provides an advanced lead compound for developing drugs for alleviating symptoms caused by cholinergic hypofunction in advanced AD.