Search

Melatonin (MLT) is a cytoprotective agent holding potential to prevent cadmium (Cd) toxicity and its impact in testicular function and fertility. In this study, we explored such potential in porcine pre-pubertal Sertoli cells (SCs). Cd toxicity resulted in impaired SC viability and function, abnormal cellular H

Nerve Growth Factor (NGF) plays an important role in the reproductive system through its receptor's interaction (p75Semen samples from 10 adult rabbit bucks were collected four times (n = 40) and analyzed. NGF was quantified in seminal plasma, and the basal expression of p75Based on the level of p75The concentration of p75

The influence of NGF in male reproduction in some animal species and humans has already been assessed. Many of these effects are mediated by the distribution and abundance of tropomyosin receptor kinase A (TrKA) and p75 neurotrophin (p75NTR) receptors on sperm cells. The aim of this research was to investigate the role of NGF and its receptors, TrKA and p75NTR, in rabbit sperm outcomes during in vitro storage. Major semen traits (kinetic parameters, apoptotic, necrotic and live sperm) were recorded in rabbit semen samples from 0 to 12 h of storage (every 4 h). Three experimental hypotheses were formulated: i) sperm storage changes NGF receptor abundance in rabbit sperm; ii) TrKA and p75NTR differently modulate NGF signalling (assessed by the neutralisation of receptors); iii) NGF-receptor interactions show different responses during storage (evaluated by the addition of exogenous NGF). The results demonstrate that: (i) the receptor number changed in a time-dependent manner with a significant increase in p75NTR after 8–12 h of storage; ii) the neutralisation of NGF receptors largely affected VCL, apoptotic, necrotic and live cells during sperm storage, i.e. blockade of TrKA significantly increased speed, capacitation, necrosis and apoptosis, whereas blockade of p75NTR improved motility and live cells; iii) the addition of exogenous human NGF (100 ng/mL) at different time points of storage (0, 4, 8 h) differently influenced sperm traits i.e. NGF addition at time 0 positively affected all the pro-vital traits (kinetic, live cells) whereas, after 4–8 h, the effect of NGF was null or negative. In conclusion, NGF affects kinetic and other physiological traits (capacitation, apoptosis and necrosis) of rabbit sperm in a time-dependent manner. Most of these modifications are modulated by the receptors involved (TrKA or p75NTR), which changed considerably during sperm storage (increase of p75NTR).

The nerve growth factor (NGF), a member of the neurotrophins family, plays an important role in the nervous system but also in the reproductive apparatus and in sperm traits. The aim of this review is to summarize the effect of NGF on sperm functions of mammals. NGF was detected in seminal plasma of many animal species and its receptors, TrkA and p75NTR, are present in both epididymal and ejaculated sperm. The NGF, either endogenous or exogenous, may affects the kinetics and other sperm traits (e.g. capacitation, apoptosis, necrosis and acrosome reaction) and these effects appear modulated by the different receptors involved (TrkA or p75NTR). Although the animal species can affect the localization of receptors, TrkA seems mainly to be confined in the head and p75NTR in the midpiece and tail. Considering that some seminal disorders and sperm traits have been correlated with a lower NGF concentration, this review provides recent insights on the role of NGF on sperm cells and the possible mechanism implicated.

Background The nerve growth factor (NGF), a member of the neurotrophins family, plays an important role not only in the nervous but also in other non-nervous systems such as the reproductive system. The aim of the paper is to study the in vitro effect of NGF on rabbit sperm functions. Methods Ten adult rabbit bucks were collected five times, and pooled semen samples have been analysed. NGF was quantified in seminal plasma, and the distribution of NGF receptors (TrKA and p75NTR) in sperm was established. Moreover, the dose-effect of NGF on motility rate and track speed was evaluated. Successively, the effect of the neutralisation of NGF receptors was assessed to verify the specific role of each receptor. Untreated sperm were used as control. Results Our study identified several interesting results: i) We detected NGF in seminal plasma and TrKA and p75NTR in sperm surface. In particular, TrKA is localised in the head and p75NTR in the midpiece and tail of rabbit sperm. ii) Once the optimal dose of NGF (100 ng/mL) was established, its addition affected both kinetics and other physiological traits (capacitation, apoptosis and necrosis) of rabbit sperm. (iii) The neutralisation of TrKA and p75NTR receptors affected sperm traits differently. In particular, sperm speed, apoptosis and capacitation seemed mainly modulated via p75NTR receptor, whereas motile, live cells, necrosis and acrosome reaction were modulated via TrKA. Conclusion For the first time, we showed the presence of p75NTR in rabbit sperm. NGF affects kinetic and other physiological traits of rabbit sperm. Most of these changes are modulated by the receptors involved (TrKA or p75NTR). Considering that some seminal disorders in human have been correlated with a lower NGF concentration and no studies have been done on the possible involvement of NGF receptors, these findings also provide new insights on human fertility.

Nerve growth factor and its receptors, TrkA and p75NTR, are involved in inflammation and airways diseases, but their role in chronic obstructive pulmonary disease is still unclear and not well investigated. our data indicate the stage dependent variation of nerve growth factor and its receptors in chronic obstructive pulmonary disease progression. In fact, for the first time, this study evaluates the presence of nerve growth factor and its receptors in serum and in peripheral blood mononuclear cells of patients with different stages of chronic obstructive pulmonary disease compared to healthy subjects, non-smoker and current smoker. Serum monocyte chemoattractant protein-1, tumor necrosis factor-α, interleukin-10 and forced expiratory volume in 1 s were also analyzed. Compared to healthy subjects, chronic obstructive pulmonary disease patients presented a staging-dependent increase in serum nerve growth factor, negatively correlated to forced expiratory volume in 1 s and positively to monocyte chemoattractant Protein-1. The percentage of p75NTR+ peripheral blood mononuclear cells increased in early stages of chronic obstructive pulmonary disease (I–II), while TrKA+ peripheral blood mononuclear cells increased in late stages (III–IV). Our data demonstrate the involvement and modulation of nerve growth factor and its receptors in chronic obstructive pulmonary disease and in its staging.

Smoke components, such as nicotine and its major metabolites, cross the blood-testis barrier and are detectable in the seminal plasma of both active smokers and individuals exposed to cigarette smoke. In vivo studies in a rat model have further demonstrated that nicotine exposure reduces the weight of the testis, as well as the number of spermatocytes and spermatids, and affects the ultrastructure of Sertoli cells (SC) - which serve as sentinels of spermatogenesis - causing intense germ cell sloughing in the tubular lumen that compromises offspring fertility. This study sought to determine the effects of nicotine on the viability and function of purified pig pre-pubertal SC. Nicotine exposure reduced the mRNA expression and protein levels of anti-Mullerian hormone (AMH) and inhibin B and impaired FSH-r sensitivity via the downregulation of FSH-r and aromatase gene expression compared to untreated SC. Overall, our study suggests that nicotine can significantly alter extracellular matrix and tight junction protein gene expression (e.g., laminin, integrin, and occludin), thus compromising cross-talk between the interstitial and tubular compartments and enhancing blood-testis barrier (BTB) permeability via downregulation of the mitogen-activated protein kinase (MAPK) pathway. These findings further elucidate a potential mechanism of action underlying nicotine exposure's detrimental effects on SC function in vivo.

[EN] The addition of aminopeptidase inhibitors (AMIs) to rabbit semen extenders could be a solution to decrease the hormone degradation (GnRH) by the aminopeptidases existing in the seminal plasma. Therefore, the quantity of GnRH needed to induce ovulation in doe would be comparable with the amount administered intramuscularly (i.m.). This study was conducted to evaluate the effects of two AMIs (bestatin and EDTA) on rabbit semen quality parameters, beta nerve growth factor ((beta-NGF) degradation and reproductive performance after artificial insemination. Results showed that seminal quality was not affected by the incubation with AMIs; the values of motility, acrosome integrity and sperm viability were not significantly different between the AMIs and the control groups (positive i.m. and negative intravaginally without AMIs). In addition, the aminopeptidase activity of seminal plasma was inhibited in a 55.5% by the AMIs as well as beta-NGF degradation. On the other hand, regarding the effect of AMIs on reproductive performance, our results showed that the presence of bestatin and EDTA did neither affect fertility (85.3 vs. 88.6%), nor the prolificacy rate (10.12 vs. 10.51 kits per delivery), comparing AMIs group to positive control group, respectively. We conclude that the addition of specific AMIs in the rabbit semen extender has no effect on reproductive performance. Therefore, due to the fact that AMIs inhibit part of the aminopeptidase activity that degrades the GnRH analogue and beta-NGF, they could be used to develop new extenders with less hormone concentration. (C) 2017 Elsevier Inc. All rights reserved., This research was supported in part by the RTA2013-00058-00-00 from INIA, the European Social Fund and the European FEDER Funds. L. Casares-Crespo is supported by a scholarship from Instituto Valenciano de Investigaciones Agrarias (IVIA) and the European Social Fund. P. Fernandez-Serrano is supported by funds from Instituto Valenciano de Investigaciones Agrarias (IVIA) and Ministerio de Empleo y Seguridad Social (Programa de Garantia Juvenil).

The association of lysosomal dysfunction and neurodegeneration has been documented in several neurodegenerative diseases, including Alzheimer's Disease (AD). Herein, we investigate the association of lysosomal enzymes with AD at different stages of progression of the disease (mild and severe) or with mild cognitive impairment (MCI). We conducted a screening of two classes of lysosomal enzymes: glycohydrolases (β-Hexosaminidase, β-Galctosidase, β-Galactosylcerebrosidase, β-Glucuronidase) and proteases (Cathepsins S, D, B, L) in peripheral blood samples (blood plasma and PBMCs) from mild AD, severe AD, MCI and healthy control subjects. We confirmed the lysosomal dysfunction in severe AD patients and added new findings enhancing the association of abnormal levels of specific lysosomal enzymes with the mild AD or severe AD, and highlighting the difference of AD from MCI. Herein, we showed for the first time the specific alteration of β-Galctosidase (Gal), β-Galactosylcerebrosidase (GALC) in MCI patients. It is notable that in above peripheral biological samples the lysosomes are more sensitive to AD cellular metabolic alteration when compared to levels of Aβ-peptide or Tau proteins, similar in both AD groups analyzed. Collectively, our findings support the role of lysosomal enzymes as potential peripheral molecules that vary with the progression of AD, and make them useful for monitoring regenerative medicine approaches for AD.

Osteoarthritis (OA) of the knee is the most common form of non-traumatic joint disease. Previous studies have shown the involvement of β-NGF and its receptors TrKA and p75NTR in OA-related pain, but their role in its pathogenesis is still unclear. The aim of our study was to investigate the amount of β-NGF and the expression levels of its receptors on cells isolated from synovial fluid and blood from OA patients who had undergone total knee arthroplasty, in order to check any possible correlation with the disease staging. Our results show a progressive stage-related increase of β-NGF and its receptors both in serum and synovial fluid. Furthermore, with respect to control subjects, OA patients show an increased amount of inflammatory monocytes along with an increased expression of β-NGF, TrKA and p75NTR. In conclusion, our study suggests a stage-related modulation of β-NGF and its receptors in the inflammatory process of OA.

Objective To assess the effects of xylazine and dexmedetomidine on equine chondrocytes, in vitro . Study design Prospective, experimental study. Study material Equine articular chondrocytes from five male horses. Methods Chondrocytes were isolated from healthy equine articular cartilage of the metacarpo/metatarsophalangeal joints. Cell viability was assessed using the WST-8 assay by exposing chondrocytes to xylazine (0.5, 1, 2, 4, 8, 16.6, 25, 50 mg mL −1 ) or dexmedetomidine (0.001, 0.005, 0.01, 0.05, 0.175, 0.25 mg mL −1 ) for 15, 30 and 60 minutes. Based on the results of these tests, cells were treated with xylazine (1, 4, 25 mg mL −1 ) or dexmedetomidine (0.05, 0.175, 0.25 mg mL −1 ) for 15 minutes to further evaluate: cell viability by neutral red uptake; cell membrane integrity by lactate dehydrogenase release and by fluorescence microscopy with Hoechst 33342 and propidium iodide (PI), and apoptosis by flow cytometry using double staining with annexin V-fluorescein isothiocyanate/PI and by cell morphology. Results Both drugs reduced cell viability in a dose-dependent manner. Specifically, all xylazine concentrations, except 0.5 mg mL −1 and 1 mg mL −1 , significantly reduced cell viability, whereas the effects of dexmedetomidine were evident only at 0.175 mg mL −1 and 0.25 mg mL −1 . The highest concentrations of xylazine (25 mg mL −1 ) and dexmedetomidine (0.25 mg mL −1 ) caused loss of membrane integrity. Cell morphology and flow cytometry analyses demonstrated signs of late apoptosis in xylazine-treated cells, and signs of late apoptosis and necrosis in dexmedetomidine-treated cells. Conclusions and clinical relevance This study offers new insights into the potential chondrotoxicity induced by dexmedetomidine and xylazine. Therefore, the intra-articular administration of α 2 -agonists should be conducted with care, especially for doses of ≥ 4 mg mL −1 of xylazine and 0.175 mg mL −1 and 0.25 mg mL −1 of dexmedetomidine.

Experiments were devised to characterize the expression of nerve growth factor, beta polypeptide (NGF), and its cognate receptors neurotrophic tyrosine kinase receptor type 1 (NTRK1) and nerve growth factor receptor (NGFR) in rabbit male sex organs, as well as the concentrations of NGF in both seminal and blood plasma of sexually mature male rabbits. Immunoreactivity and gene expression for NGF and cognate receptors were detected in testis, prostate gland and seminal vesicle. The highest levels of NGF and NTRK1 transcripts were found in the prostate, while intermediate expressions were found in the testis. NGFR transcripts were expressed at the same levels in both testis and prostate and were more abundant than in seminal vesicles. The widespread distribution of NGF in all prostate glandular cells, together with its relative high mRNA abundance, confirms that the prostate of rabbits is the main source of this neurotrophin. In conclusion, the present data suggest that the NGF system is involved in the testicular development and spermatogenesis of rabbits and that NGF may act as a potential ovulation-inducing factor being abundantly present in the seminal plasma.

Neurotrophins, originally identified as neuronal survival and differentiation factors, exert their actions through tyrosine kinase receptors such as TrKA, in the case of the nerve growth factor. Neurotrophins also interact with p75, a common receptor devoid of kinase activity and connected to apoptosis. Here we show that nerve growth factor, TrKA and p75 are expressed in cell lines of human cancers of various non-neuronal lineages, including a panel of muscular sarcomas, and we show that all cell lines investigated actively release nerve growth factor into the medium. Treatment by AG879 (a tyrosine kinase inhibitor that inhibits TrKA phosphorylation, but not TrKB and TrKC) or by neutralizing antibodies anti-nerve growth factor and anti-TrKA dramatically decreases their proliferation with a variable increase in apoptosis. Similarly, p75 transfection induced a significant increase in apoptosis. Furthermore, for the first time we have determined by high-performance liquid chromatography the pharmacokinetic profile of a novel preparation of AG879 and we have established an optimal plasmatic concentration for in-vivo administration. Treatment with AG879 in immunodepressed mice grafted with leiomyosarcoma or promyelocytic leukemia cells resulted in dramatic reductions in tumor sizes. In conclusion, our data have a novel preclinical potential for revealing a possible therapeutical utility in targeting in-vivo nerve growth factor/TrKA by AG879 or neutralizing antibody anti-TrKA in cancer proliferation and in muscle sarcomas, in particular.

It is known that gamma-tocopherol inhibits human prostate cancer cell proliferation via down-regulation of cyclin-related signalling but tocopherol and tocotrienol metabolites with a shortened phytyl chain, carboxyethyl hydroxychromans, were not previously investigated as anti-proliferative agents. In this study, the effect of the two main tocopherols, namely, alpha-tocopherol and gamma-tocopherol, and their corresponding metabolites (alpha- and gamma-carboxyethyl hydroxychromans) was studied on proliferation and cyclin D1 expression of the prostate cancer cell line PC-3. The hydrosoluble vitamin E analogues Trolox and alpha-tocopherol succinate were also tested. The most effective inhibitors of PC-3 proliferation were gamma-tocopherol and gamma-carboxyethyl hydroxychroman. Their effect was discernable at 1 microM and reached a plateau at concentrations > or = 10 microM with maximal inhibition values ranging between 70 and 82%. alpha-Tocopherol, alpha-carboxyethyl hydroxychroman, and the analogue Trolox were much less effective; a weak effect was observed for concentrations < or = 10 microM and a maximal inhibition of less than 45% was found at 50 microM concentration. PC-3 cells showed higher inhibition, particularly by the gamma derivatives, than HTB-82 and HECV cells. Tocopherols and carboxyethyl hydroxychromans exerted an inhibitory effect on cyclin D1 expression parallel to the retardation of cell growth. gamma-Carboxyethyl hydroxychroman and gamma-tocopherol showed effects also upstream of the cyclin modulation. Furthermore, the inhibition of cyclin D1 expression by gamma-carboxyethyl hydroxychroman was competed for by alpha-carboxyethyl hydroxychroman. In conclusion, this study shows that carboxyethyl hydroxychroman metabolites are as effective as their vitamin precursors to inhibit PC-3 growth by specific down-regulation of cyclin expression, with the gamma forms being the most effective ones. Although the inhibition of PC-3 cell growth and diminution of cyclin expression are clearly visible, more subtle mechanistic effects of tocopherols and their corresponding carboxyethyl hydroxychroman metabolites deserve further investigations.