New insights into the significance of PARP-1 activation: flow cytometric detection of poly(ADP-ribose) as marker of bovine intramammary infection

Bovine intramammary infections are common diseases affecting dairy cattle worldwide and represent a major focus of veterinary research due to financial losses and food safety concerns. The identification of new biomarkers of intramammary infection, useful for monitoring dairy cows’ health and wellness verification, represents a key advancement having potential beneficial effects on public health. In vitro experiments, using bovine peripheral blood mononuclear cells (PBMC) stimulated with the bacterial endotoxin lipopolysaccharide (LPS) allowed to perform a flow cytometric assay to evaluate in vivo poly-ADP-ribose (PAR) levels. Results showed a significant increase of PAR after 1h of treatment, which is consistent with the involvement of PARP activity in the inflammatory response. This study investigated PARP-1 activation in leukocyte subpopulations from bovine milk samples during udder infection. A flow cytometric assay was therefore performed to evaluate the PAR content on milk leukocytes subsets of cows with and without intramammary infection (IMI). Results showed that milk lymphocytes and macrophages isolated from cows with IMI had a significant increase of PAR content compared to uninfected samples. These results suggest mastitis as a new model for the study of the role of PARP in zoonotic inflammatory diseases, thereby opening new horizons for the "One Health" perspective connecting animal and human health

Assessment of Poly(ADP-ribose) Polymerase1 (PARP1) expression and activity in cells purified from blood and milk of dairy cattle

Poly(ADP-ribosyl)ation (PAR) is a post-translational protein modification catalysed by enzyme member of the poly(ADP-ribose) polymerases (PARPs) family. The activation of several PARPs is triggered by DNA strand breakage and the main PARP enzyme involved in this process is PARP1. Besides its involvement in DNA repair, PARP1 is involved in several cellular processes including transcription, epigenetics, chromatin re-modelling as well as in the maintenance of genomic stability. Moreover, several studies in human and animal models showed PARP1 activation in various inflammatory disorders. The aims of the study were (1) to characterize PARP1 expression in bovine peripheral blood mononuclear cells (PBMC) and (2) to evaluate PAR levels as a potential inflammatory marker in cells isolated from blood and milk samples following different types of infection, including mastitis. Our results show that (i) bovine PBMC express PARP1; (ii) lymphocytes exhibit higher expression of PARP1 than monocytes; (iii) PARP1 and PAR levels were higher in circulating PBMCs of infected cows; (iv) PAR levels were higher in cells isolated from milk with higher Somatic Cell Counts (SCC > 100,000 cells/mL) than in cells from milk with low SCCs. In conclusion, these findings suggest that PARP1 is activated during mastitis, which may prove to be a useful biomarker of mastitis

Molecular characterization of the NRAMP1 gene in buffalo

NRAMP1 (natural-resistance-associated macrophage protein) gene influences the initial phase of bacterial cellular infections, regulating macrophage activation. Recent literature on buffalo has attempted to associate the genotypes at the polymorphic microsatellite, that is located in the 3'-UTR of the gene, with either susceptibility to brucellosis or improved macrophage function. However, contradictory results were reported. In the present work, we have sequenced the whole coding region, as well as part of the introns and UTRs, of the NRAMP1 gene in 49 Mediterranean buffaloes, including both serologically positive and negative animals to Brucella abortus test. We have detected 12 mutations. Nineteen haplotypes were built from the detected variant alleles, so demonstrating the high variability of this gene in buffalo, but no significant differences in haplotype frequencies were found between serologically positive/negative animals

Comparison of metabolic, oxidative and inflammatory status of Simmental × Holstein crossbred with parental breeds during the peripartal and early lactation periods.

AbstractThe aim of the research reported in this paper was to evaluate plasma concentrations of energy, oxidative and inflammatory biomarkers of Simmental (sire) × Holstein (dam) crossbred cows, in comparison with the two parental breeds during the peripartal and early lactation periods and to estimate the effects of heterosis for these traits. Thirty-three animals, managed under the same conditions, 8 Simmental (SI), 9 Holstein (HO) and 16 crossbred (CR) cows were enrolled in this study. Glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatine kinase (CK), total protein, albumin, creatinine and urea were determined in blood sampled at six different time points (30 ± 3 and 15 ± 3 d before the expected calving date, at calving and 15, 30 and 60 d after calving). Furthermore, derived reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), interleukin-6 (IL-6), haptoglobin (Hp) and serum amyloid A protein (SAA) were determined to evaluate inflammatory and oxidative status. Results showed that the CR group had significantly lower average values of glucose and NEFA when compared to HO group; signifcantly lower values of urea than SI group and significantly higher values of creatinine than HO. Furthermore, CR cows showed the lowest average value of d-ROMs with respect to SI and HO parental breeds. Finally, the average value of haptoglobin was significantly lower in CR and HO groups, when compared to SI group. As for the heterosis we found the highest (positive) percentage for CK (98%) and BAP (47%) and the lowest (negative) percentage for OSi (−75%) and d-ROMs (−39%). A negative percentage was also found for the glucose (−11%) and NEFA (−20%) toward the Simmental parental breed. Our results suggest a different response among the three genetic groups during the peripartal and early lactation periods. In particular, CR and SI cows seem more adaptable regarding energy metabolism and oxidative status. Heterosis led to a positive effect on those parameters in Simmental (sire) × Holstein (dam) crossbred cows F1 population (50% Simmental and 50% Holstein)

Association analyses of single nucleotide polymorphisms in the <i>leptin</i> and <i>leptin receptor</i> genes on milk and morphological traits in Holstein cows

n/

Flow Cytometry-Detected Immunological Markers and on Farm Recorded Parameters in Composite Cow Milk as Related to Udder Health Status

Flow cytometry is a powerful technology used in many fields of cell biology. It is also used as a routine method to count somatic cells in milk and to characterize bovine milk leukocytes. In this study, we used flow cytometry to simultaneously assess the viability, the percentage of the single subsets of leukocytes and to quantify the expression of CD11b, an immunological marker of cell activation status. Immunological markers were then related with on farm recorded parameters as milk electrical conductivity (MEC) and average milk flow rate (MFR). Composite milk samples were collected from 43 cows, nine of which had naturally infected udders and 34 of which had no infected udders. First, the milk samples were classified according to bacteriological test in positive and negative. The results showed that the negative samples to bacteriological test had: (i) significantly higher percentages of live lymphocytes; (ii) significantly lower percentages of CD11b+ leukocytes; (iii) significantly lower MEC and higher MFR values. Then, samples were classified in three groups according to somatic cell count (SCC): Group A (n = 15), samples with SCC &le; 100,000 cells/mL, all negative to bacteriological analysis; Group B (n = 11), samples with 100,000 &lt; SCC &lt; 300,000 cells/m, with four samples positive to bacteriological analysis; Group C (n = 17), samples with SCC &ge; 300,000 cell/mL with five samples positive to bacteriological analysis. Multivariate discriminant analysis was used to verify which flow cytometry immunological markers and on farm recorded parameters could better discriminate among the different groups of SCCs. Linear discriminant analysis (LDA) indicated that 5 of the 10 parameters could best be used to reveal the differences between positive and negative samples among the considered groups of SCCs. Furthermore, the Canonical discriminant analysis (CDA) indicated that composite milk samples with different SCC and infection status were clearly separated from each other in a two-dimensional space. In conclusion, the study highlighted that: (1) the conventional flow cytometry analysis applied on milk samples is a useful tool to investigate immunological parameters as potential indicators of udder health; (2) the combined evaluation of live milk leukocytes and recorded farm parameters could be useful to assess udder health status in dairy cows. The results obtained from this pilot study on few data require new and larger trials to be confirmed

Evaluation of leptin receptor expression on buffalo leukocytes

Experimental evidences support a direct role for leptin in immunity. Besides controlling food intakeand energy expenditure, leptin was reported to be involved in the regulation of the immune system inruminants. The aim of this work was to highlight the expression of leptin receptor (LEPR) on Bubalusbubalis immune cells using a multi-approach assessment: flow cytometry, confocal microscopy and geneexpression analysis. Flow cytometric analysis of LEPR expression showed that peripheral blood mono-cytes were the predominant cells expressing LEPR. This result was corroborated by confocal microscopyand RT-PCR analysis. Moreover, among lymphocytes, LEPR was mainly expressed by B lymphocytes andNatural Killer cells. Evidence of LEPR expression on buffalo blood leukocytes showed to be a good indica-tor of the responsivity of these cells to leptin, so confirming the involvement of leptin in buffalo immuneresponse

Molecular characterization of the NRAMP1 gene in buffalo

NRAMP1 (natural-resistance-associated macrophage protein) gene influences the initial phase of bacterial cellular infections, regulating macrophage activation. Recent literature on buffalo has attempted to associate the genotypes at the polymorphic microsatellite, that is located in the 3'-UTR of the gene, with either susceptibility to brucellosis or improved macrophage function. However, contradictory results were reported. In the present work, we have sequenced the whole coding region, as well as part of the introns and UTRs, of the NRAMP1 gene in 49 Mediterranean buffaloes, including both serologically positive and negative animals to Brucella abortus test. We have detected 12 mutations. Nineteen haplotypes were built from the detected variant alleles, so demonstrating the high variability of this gene in buffalo, but no significant differences in haplotype frequencies were found between serologically positive/negative animals

Image_1_Hyperthermia-induced changes in leukocyte survival and phagocytosis: a comparative study in bovine and buffalo leukocytes.TIF

Heat stress negatively affects health, welfare, and livestock productivity by impairing immune function, increasing disease incidence. In recent years, there has been increasing interest in understanding the immune system of water buffalo due to the growing economic impact of this species for the high quality and nutritional value of buffalo milk. While there are common responses across bovine and buffalo species, there are also some species-specific variations in the physiological responses to heat stress, mainly attributed to differences in metabolism and heat dissipation efficiency. At cellular level, the exposure to thermal stress induces several anomalies in cell functions. However, there is limited knowledge about the differential response of bovine and buffalo leucocytes to early and late exposure to different degrees of thermal exposure. The aim of this study was to compare the in vitro effect of hyperthermia on apoptosis and phagocytosis in leukocytes from bovine and buffalo species. For this, whole blood samples of six bovines and nine buffaloes were incubated at 39°C (mimicking normothermia condition) or 41°C (mimicking heat stress condition) for 1, 2, and 4 h. Two flow cytometric assays were then performed to evaluate apoptosis and determine functional capacity of phagocytic cells (neutrophils and monocytes). The results showed that the viability of bovine and buffalo leukocytes was differently affected by temperature and time of in vitro exposure. A higher percentage of apoptotic leukocytes was observed in bovines than in buffaloes at 39°C (3.19 vs. 1.51, p  0.05). However, for monocytes, the differences between species were significant for both phagocytosis activity and capacity with lower percentages of bovine phagocytic monocytes after 2 h at 39°C and after 1 h at 41°C. The bovine monocytes showed lower MFI values for all temperature and time variations than buffaloes (37538.91 vs. 90445.47 at 39°C and 33752.91 vs. 70278.79 at 41°C, p < 0.05). In conclusion, the current study represents the first report on the comparative analysis of the effect of in vitro heat stress on bovine and buffalo leukocyte populations, highlighting that the leukocytes of buffalo exhibit relatively higher thermal adaptation than bovine cells.</p

Interferon Tau (IFNt) and Interferon-Stimulated Genes (ISGs) Expression in Peripheral Blood Leukocytes and Correlation with Circulating Pregnancy-Associated Glycoproteins (PAGs) during Peri-Implantation and Early Pregnancy in Buffalo Cows

The objective of this study was to analyze interferon-stimulated genes (ISGs) and interferon tau (IFNt) gene expression in peripheral blood leukocytes during the peri-implantation period and until 40 days of pregnancy in buffalo cows. Relationships were also examined between the expression of ISGs and IFNt and pregnancy-associated glycoproteins (PAGs) peripheral plasma concentration. Buffalo cows were synchronized and artificially inseminated (d 0). Blood samples were collected on days 0, 18, 28 and 40 after artificial insemination (AI) for peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes (PMNs) isolation and PAGs radioimmunoassay analysis. The study was carried out on 21 buffalo cows divided ex post into Pregnant (n = 12) and Non-pregnant (n = 9) groups. Steady state levels of OAS1, MX2, ISG15 and IFNt mRNA were measured by RT-qPCR and their estimated marginal means (p &lt; 0.01 for all) were higher in pregnant than non-pregnant buffaloes, both in PBMCs and PMNs. In PBMCs, pairwise comparisons showed that OAS1 and MX2 expressions differed between pregnant and non-pregnant buffaloes on all the days of observation (p &lt; 0.001), while significant differences in ISG15 and IFNt started from day 28 post-AI (p &lt; 0.05). In PMNs, ISG15 expression differed between groups only at days 18 and 28 (p &lt; 0.001), while comparisons were always significant for IFNt (p &lt; 0.05). The expression of all genes, except ISG15 as determined in PMNs, was positively associated with PAGs plasma concentrations (p &lt; 0.05). This work showed a significant increase in ISGs and IFNt expressions in PBMCs and PMNs in buffalo during the peri-implantation period and early pregnancy, and their correlation with PAGs plasma concentration