Effects of the supplementation with an high-polyphenols extra-virgin olive oil on kinetic sperm features and seminal plasma oxidative status in healthy dogs

The aim of this work was to evaluate the effects of the supplementation of two extra-virgin olive oils (EVOO) having different polyphenols content, on canine spermatozoa kinetic parameters and seminal plasma oxidative status. The study was conducted on 12 clinically healthy dogs of different breeds (2-7 years, 5-48 kg of body weight) divided into two groups: an experimental group supplemented with EVOO (Coratina cultivar) high in polyphenols (H-P) and a control group fed EVOO (Cima di Bitonto cultivar) low in polyphenols (L-P). The oil was daily administered per os (1 ml/3 kg BW) before meal. Semen collection was made twice at 15 days distance (D0₁ and D0₂ ) and then at 30 (D30), 60 (D60) and 90 (D90) days. Semen concentration and kinetic parameters were measured using computer-assisted sperm analysis (CASA) system to evaluate: sperm total count, sperm motile (MOT%), progressive motility (PROGR%) and its fractions, straight-line velocity (VSL, μm/s), curvilinear velocity (VCL, μm/s), average path velocity (VAP, μm/s), amplitude of lateral head displacement (ALH, μm), beat cross frequency (BCF, Hz), straightness (STR%) and linearity (LIN%). On seminal plasma, reactive oxygen species (ROS) and biological antioxidant potential (BAP) were tested. From findings, no differences were found for sperm MOT, VSL, VCL, VAP, ALH, BCF, STR, LIN and BAP. A gradual enhancement of PROGR% was observed in H-P group (p < .01). The ROS levels were higher in dogs H-P compared to the other group (p < .05). In conclusion, our results highlight the positive effects of EVOO polyphenols on sperm PROGR% in healthy dogs.

Isolation, proliferation, cytogenetic, and molecular characterization and in vitro differentiation potency of canine stem cells from foetal adnexa: a comparative study of amniotic fluid, amnion, and umbilical cord matrix

The possibility to isolate canine mesenchymal stem cells (MSCs) from foetal adnexa is interesting since several canine genetic disorders are reported to resemble similar dysfunctions in humans. In this study, we successfully isolated, cytogenetically and molecularly characterized, and followed the differentiation potency of canine MSCs from foetal adnexa, such as amniotic fluid (AF), amniotic membrane (AM), and umbilical cord matrix (UCM). In the three types of cell lines, the morphology of proliferating cells typically appeared fibroblast-like, and the population doubling time (DT) significantly increased with passage number. For AF- and AM-MSCs, cell viability did not change with passages. In UCM-MSCs, cell viability remained at approximately constant levels up to P6 and significantly decreased from P7 (P < 0.05). Amnion and UCM-MSCs expressed embryonic and MSC markers, such as Oct-4 CD44, CD184, and CD29, whereas AF-MSCs expressed Oct-4, CD44. Expression of the hematopoietic markers CD34 and CD45 was not found. Dog leucocyte antigens (DLA-DRA1 and DLA-79) were expressed only in AF-MSCs at P1. Isolated cells of the three cell lines at P3 showed multipotent capacity, and differentiated in vitro into neurocyte, adipocyte, osteocyte, and chondrocyte, as demonstrated by specific stains and expression of molecular markers. Cells at P4 showed normal chromosomal number, structure, and telomerase activity. These results demonstrate that, in dog, MSCs can be successfully isolated from foetal adnexa and grown in vitro. Their proven stemness and chromosomal stability indicated that MSCs could be used as a model to study stem cell biology and have an application in therapeutic programs.

312 ISOLATION, PROLIFERATION, AND CHARACTERIZATION OF MESENCHYMAL STEM CELLS FROM AMNIOTIC FLUID, AMNION, AND UMBILICAL CORD MATRIX IN THE DOG

Mesenchymal stem cells (MSC) are defined as multipotent stem cells that can differentiate into various cell types in vivo and in vitro under controlled conditions. These cells express specific markers detectable by analysis at the mRNA or protein level. Important sources of MSC could be fetal adnexa, such as amniotic fluid (AF), amnion (AM), and umbilical cord matrix (UCM). Canine MSC should be of use for cell-based therapies and tissue engineering improving treatment of several diseases. Moreover, the dog has been considered an attractive animal model to study human diseases. In the present study, we successfully isolated and molecularly characterised AF-MSC, AM-MSC, and UCM-MSC from dogs. Chromosomal stability and telomerase activity were also investigated. Samples were recovered after elective ovariohysterectomy in 3 bitches 25 to 40 days of gestational age. After isolation, cells were maintained in culture (Bossolasco et al. 2006 Cell Res. 16, 329–336) for different passages to perform growth and doubling time (DT) studies. Expression analyses of embryonic (Oct-4, Nanog), mesenchymal (CD44, CD184, CD29), and haematopoietic (CD34, CD45) markers were carried out by RT-PCR. Karyotype analysis was performed by Q banding. Telomerase activity was analysed by TRAPeze Telomerase Detection Kit. In all 3 cell types, the morphology of proliferating cells appeared typically fibroblast-like. In the growth study, cells isolated from AF and AM were cultured until P3, and cells isolated from UCM were maintained until P7. The population DT in AF-MSC was significantly increased (Student’s t-test: P < 0.05) when comparing P1 v. P4. In AM-MSC, DT increased significantly in P1 v. P2 (P < 0.001), and in UCM-MSC, DT significantly increased in P1 v. P4 (P < 0.001). In AF-MSC, cell viability did not change with passages. In AM-MSC, cell viability significantly decreased (P < 0.001) between P1 and P4. In UCM-MSC, cell viability remained at approximately constant levels up to P6 and significantly decreased at P7 (P < 0.001). Amnion and UCM-MSC expressed Oct-4 and CD44, CD184, and CD29, whereas AF-MSC expressed only Oct-4 and CD44. Nanog, CD34, and CD45 were never found to be expressed in any cell line at any passage. In all cell lines, analysed metaphases at P4 showed normal chromosomal number and structure. Telomerase activity was observed in UCM-MSC, whereas tests on AF and AM-MSC are still on going. We first reported data on isolation, in vitro culture, and characterisation of MSC from AM and UCM in the dog. Cells expressed embryonic and MSC markers beginning at P1 and showed normal karyotype. These data indicated that canine MSC from fetal adnexa could be used to study stem cell biology and their application in therapeutic programs. Financial support was provided by Fondi di Ateneo 2009. University of Bari Aldo Moro (COD. ORBA09UDWX) (Resp. Sci. Maria Elena Dell’Aquila).

307 INVOLVEMENT OF THE CALCIUM SENSING RECEPTOR IN GROWTH AND PROLIFERATION OF STEM CELLS FROM EQUINE UMBILICAL CORD MATRIX

The calcium sensing receptor (CaSR) plays a key role in cells involved in calcium (Ca2+) homeostasis by directly sensing changes in extracellular Ca2+ concentration ([Ca2+]o), and external Ca2+ is a potent mediator of cell proliferation. The present study investigated the effects of high [Ca2+]o and of the CaSR agonist NPS R-467 on growth and proliferation of equine size-sieved umbilical cord matrix mesenchymal stem cells (UCM-MSC). The involvement of CaSR on observed cell response was analysed at the mRNA and protein level. Two subpopulations of UCM-MSC, isolated using multi-dishes with transwell inserts of 8-μm pores and expressing MSC markers (CD105, CD44, CD29; Corradetti et al. 2010 Reprod. Fertil. Dev. 22, 347–348), were analysed. Cells were cultured in medium containing: (A) low [Ca2+]o (0.37 mM), (B) high [Ca2+]o (2.87 mM), (C) NPS R-467 (3 μm) in the presence of high [Ca2+]o, and (D) the CaSR antagonist NPS 2390 (10 μm for 30′) followed by NPS R-467 in the presence of high [Ca2+]o. Growth and proliferation rates were compared among treatments (Student’s t-test). The CaSR expression and subcellular localization were investigated by real-time quantitative RT-PCR, immunofluorescence, and confocal microscopy. In the >8-μm cell line, the addition of NPS R-467, in the presence of [Ca2+]o, significantly increased cell growth after day 7 of culture (C v. A and B; P < 0.001). Increasing [Ca2+]o was not effective in this cell line (B v. A; not significant). In the <8-μm cell line, NPS R-467 increased cell growth, even at a lower extent (C v. A; P < 0.05), as observed on day 9 of culture. In this cell line, an increased proliferation rate was observed upon [Ca2+]o increase (B v. A; P < 0.05). In both cell lines, preincubation with NPS 2390 significantly inhibited the agonistic effect of NPS R-467. In both cell lines, a stimulatory effect of additional calcium and NPS R-467 on cell proliferation, in terms of reduced DT values, was observed. In the 2 cell lines, CaSR expression was down-regulated in the presence of high calcium and in NPS R-467-treated cells compared with controls (B and C v. A cells; P < 0.001). Treatment with high calcium or NPS R-467 reduced CaSR labelling in the cytosol and increased it at the cortical level. We found that CaSR is expressed at mRNA and protein levels in equine UCM-MSC, and it is functionally active because the selective CaSR agonist NPS R-467 induced a stimulatory effect on cell growth and proliferation, which was reversed by the CaSR antagonist NPS 2390. The different responses to treatments between the 2 UCM-MSC subpopulations suggest that CaSR could be differentially activated in these cell lines. The calcimimetic NPS R-467 might be useful as an adjunctive component of media for UCM-MSC culture to obtain enough cells for down-stream purposes. Financial support was provided by Fondi di Ateneo 2009; University of Bari Aldo Moro (COD. ORBA09UDWX) (Resp. Sci. Maria Elena Dell’Aquila).

Expression of the micro-opioid receptor on Malassezia pachydermatis and its effect in modulating phospholipase production

Malassezia spp. may act as opportunistic skin pathogens in humans and animals. Malassezia pachydermatis proliferation and phospholipase production may play a pathogenic role in the occurrence of skin lesions in dogs. This study investigates the presence of mu-opioid receptor (MOR) in M. pachydermatis strains isolated from healthy dogs and dogs with skin lesions and its effects on phospholipase activity (p.a.). P.a. of 64 M. pachydermatis isolates was evaluated using different concentrations of naloxone (Nx), a MOR antagonist. Isolates were divided into Group A (i.e., 40 isolates from 26 dogs with dermatitis) and Group B (i.e., 24 isolates from 12 healthy dogs). The MOR expression was analyzed by Western blot and immunofluorescence. A statistically higher p.a. than that of the controls was found with isolates in Group A at a Nx concentration of 10(-6) M (P<0.05). No isolate in Group B displayed p.a. in either control samples or in the presence of any Nx concentration. Immunoblotting revealed two positive MOR immunoreactive bands of approximately 65 and 98 kDa. MOR expression and localization was also demonstrated by immunofluorescence in isolates from Groups A and B. This study provides the first evidence of MOR expression on M. pachydermatis cell membranes pointing to its possible role in modulating p.a. production in isolates from dogs with skin lesions.

Expression of the mu opioid receptor and effects of the opioid antagonist naloxone on in vitro maturation of oocytes recovered from anoestrous bitches

The mu-opioid receptor (MOR) is expressed in bovine, human, equine and canine oocytes, and in seasonal breeders, it is expressed with higher intensity during the anoestrous phase. Supplementation of in vitro maturation (IVM) medium with opioid agents, agonists or antagonists, was shown to affect oocyte maturation in several species such as rat, bovine and equine. This study reports the effects of supplementing IVM medium with naloxone (Nx), an opioid antagonist, on nuclear and cytoplasmic maturation rate of oocytes recovered from anoestrous bitches. Cytoplasmic maturation was examined in terms of mitochondrial (mt) distribution. In order to confirm the receptor-mediated action of Nx, in oocytes of anoestrous bitches, MOR expression was analyzed by Western blot. Cumulus-oocyte complexes, recovered from the ovaries of bitches in anoestrous, were cultured in vitro and Nx was added at the concentrations of 1 x 10(-6), 1 x 10(-8) and 1 x 10(-10) M. The rate of oocytes resuming meiosis after culture in presence of 1 x 10(-6) M Nx (29%) was significantly higher than that of oocytes of control group (12%; p < 0.05). However, treatment with Nx did not affect mt distribution pattern. In denuded oocytes and in corresponding cumulus cells, a doublet of 65 and 50 kDa was observed. We conclude that, in oocytes of anoestrous bitches, MOR is expressed and Nx significantly improves nuclear maturation rate. Further studies should be performed to elucidate the expression of other opioid receptors, such as delta and kappa, and possible interactive effects of their antagonists on canine oocyte maturation.

The presence of the mu-opioid receptor in the isthmus of mare oviduct

The presence of the mu-opioid receptor and the type of glycosylation in the third extra-cellular loop of this receptor was investigated in the isthmus of mare oviduct during oestrus by means of immunoblotting and immunohistochemistry combined with enzymatic (N-glycosidase F and O-glycosidase) and chemical (beta-elimination) treatments. Immunoblotting analysis showed that the mu-opioid receptor consists of two peptides with molecular weights of around 65 and 50 kDa. After N-deglycosylation with N-glycosidase F an additional immunoreactive peptide was observed at around 30 KDa. The cleavage of O-glycans by O-glycosidase failed in immunoblotting as well as in immunohistochemistry investigations, revealing that the third extra-cellular loop of the mu-opioid receptor expressed in mare isthmus oviduct contains some modifications of the Galbeta(1-3)GalNAc core binding to serine or threonine. Immunohistochemistry revealed the mu-opioid receptor in the mucosal epithelium, some stromal cells, muscle cells and blood vessels. In ciliated cells the mu-opioid receptor showed N-linked glycans, since the immunoreactivity was abolished after N-glycosidase F treatment, whereas it was preserved in the apical region after beta-elimination. Most non-ciliated cells expressed the mu-opioid receptor with both N- and O-linked oligosaccharides, as revealed by the abolition of immunostaining after N-glycosidase F and beta-elimination. Stromal cells, endothelial and muscle cells of blood vessels expressed the mu-opioid receptor containing both N- and O-linked oligosaccharides. Myosalpinx myocytes expressed the mu-opioid receptor with O-linked oligosaccharides. The immunopositive myocytes formed a circular coat in the intrinsic musculature, whereas they were arranged in some isolated, oblique bundles in the extrinsic musculature. In conclusion, the mu-opioid receptor could have a role in the production and the movement of isthmus lumen content that contributes to ensuring the effective condition of the sperm in the mare oviduct.

Opioid agonist/antagonist effect of naloxone in modulating rabbit jejunum contractility in vitro

Opioid peptides are the most effective drugs in controlling pain; their action is elicited by binding to specific membrane receptors. The gastrointestinal tract represents, after the nervous system, the site in which the opioid receptors are expressed at high levels. The opioid agonist morphine has a significant inhibitory effect on intestinal motility, this action is blocked by naloxone an opioid antagonist mainly active at mu and kappa receptors. In this study the presence of mu opioid receptor on rabbit jejunum was investigated by western blot. The effects of beta-endorphin, the endogenous opioid peptide with the highest affinity to the mu opioid receptor and those of naloxone on spontaneous rabbit jejunum contractions were evaluated. Beta-endorphin (10(-6) M) showed a relaxant effect on jejunum contractility while naloxone showed a dual effect inducing an increase of spontaneous contractility at low concentrations (10(-6) M, 10(-7) M, 10(-8) M) and a decrease when high concentrations (10(-3) M, 10(-4) M, 10(-5) M) were utilized. The obtained results demonstrate that mu opioid receptor is expressed in rabbit jejunum and suggest that this receptor may be involved in mediating the effects of both opioid agonist and antagonist on jejunum contractions.