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Department of Animal Sciences
The Robert H. Smith Faculty
of Agricultural, Food & Environment

The Hebrew University of Jerusalem.

P.O. Box 12, Rehovot 76100, Israel
Phone: +972-(0)8-9489119;
Fax: +972-(0)8-9465763;
Yael Lewitus, Department's Secretary
e-mail: yaellew@savion.huji.ac.il

Publications

2016
Cotter, P. F. ; Heller, D. Complex hemograms of isolator raised specific pathogen free (SPF) chicks. International Journal of Poultry Science 2016, 15, 211-217. Publisher's VersionAbstract
Heterophil/lymphocyte (H/L ratio) statistics and total white blood cell counts (TWBC) determined by light microscopic examination of blood from isolator raised specific pathogen free (SPF) chicks indicated complex hemograms. Brachial vein blood (N =12) obtained at 6 wk was spread into films, air dried, post-fixed in MeOH and Wright’s stained. H/L 1 ratios were calculated by dividing all heterophil types, typical (HT) variant (HV) and classic (HC) by the number of small (resting) lymphocytes (Ls) H/L 1 = (HT + HV + HC)/(Ls). A second ratio (H/L 2) obtained by dividing heterophils by all lymphocytes (resting, reactive and atypical, (HT + HV + HC)/ (Ls + Lm) was calculated; as was the H/L 1-H/L 2 difference (ΔH/L). TWBC’s were determined from the same films. Sorting, non-random distribution of cells and atypia affected all H/L statistics. The mean H/L 1 ratio from standard differential counts (SDC) = 0.17 and H/L 2 = 0.16. Edge based ratios (EB) were  8 times the SDC values. Atypical cells were in all samples and more common in EB counts. The H/L ratios and ΔH/L calculated from SDC and EB values were significantly different (p<0.02). Collectively these observations support earlier conclusions regarding the lack of sensitivity of a single H/L ratio, without a TWBC, or consideration of atypia to estimate welfare. Furthermore, hemograms of SPF chickens reared in isolation may be complex. © Asian Network for Scientific Information, 2016.
Goldenberg, D. ; Lublin, A. ; Rosenbluth, E. ; Heller, D. ; Pitcovski, J. Optimized polypeptide for a subunit vaccine against avian reovirus. Vaccine 2016, 34, 3178-3183. Publisher's VersionAbstract
Avian reovirus (ARV) is a disease-causing agent. The disease is prevented by vaccination with a genotype-specific vaccine while many variants of ARV exist in the field worldwide. Production of new attenuated vaccines is a long-term process and in the case of fast-mutating viruses, an impractical one. In the era of molecular biology, vaccines may be produced by using only the relevant protein for induction of neutralizing antibodies, enabling fast adjustment to the emergence of new genetic strains. Sigma C (SC) protein of ARV is a homotrimer that facilitates host-cell attachment and induce the production and secretion of neutralizing antibodies. The aim of this study was to identify the region of SC that will elicit a protective immune response. Full-length (residues 1-326) and two partial fragments of SC (residues 122-326 and 192-326) were produced in Escherichia coli. The SC fragment of residues 122-326 include the globular head, shaft and hinge domains, while eliminating intra-capsular region. This fragment induces significantly higher levels of anti-ARV antibodies than the shorter fragment or full length SC, which neutralized embryos infection by the virulent strain to a higher extent compared with the antibodies produced in response to the whole virus vaccine. Residues 122-326 fragment is assumed to be folded correctly, exposing linear as well as conformational epitopes that are identical to those of the native protein, while possibly excluding suppressor sequences. The results of this study may serve for the development of a recombinant subunit vaccine for ARV. © 2016 Elsevier Ltd.
Berman, A. ; Horovitz, T. ; Kaim, M. ; Gacitua, H. A comparison of THI indices leads to a sensible heat-based heat stress index for shaded cattle that aligns temperature and humidity stress. International Journal of Biometeorology 2016, 60, 1453-1462. Publisher's VersionAbstract
The combined temperature-humidity heat stress is estimated in farm animals by indices derived of an index based on human thermal comfort sensation. The latter index consists of temperature and humidity measures that sum to form the temperature-humidity index (THI). The hitherto unknown relative contribution of temperature and humidity to the THI was examined. A temperature-humidity data set (temperature 20–42 °C and relative humidity 10–70 %) was used to assess by regression procedures the relative weights of temperature and humidity in the variance of THI values produced by six commonly used heat stress indices. The temperature (Ta) effect was predominant (0.82–0.95 of variance) and humidity accounted for only 0.05 to 0.12 of THI variance, half of the variance encountered in animal responses to variable humidity heat stress. Significant difference in THI values was found between indices in the relative weights of temperature and humidity. As in THI indices, temperature and humidity are expressed in different physical units, their sum has no physical attributes, and empirical evaluations assess THI relation to animal responses. A sensible heat THI was created, in which at higher temperatures humidity reaches 0.25 of sensible heat, similarly to evaporative heat loss span in heat stressed animals. It relates to ambient temperature-humidity similarly to present THI; its values are similar to other THI but greater at higher humidity. In warm conditions, mean animal responses are similar in both indices. The higher sensitivity to humidity makes this index preferable for warm-humid conditions. © 2016, ISB.
Chaiseha, Y. ; Kamkrathok, B. ; Rozenboim, I. Ovarian steroids involvement in maternal care in the native Thai hen (Gallus domesticus). Animal Biology 2016, 66, 111 - 118. Publisher's Version
Li, Y. ; Kalo, D. ; Zeron, Y. ; Roth, Z. Progressive motility-a potential predictive parameter for semen fertilization capacity in bovines. Zygote 2016, 24, 70 - 82. Publisher's Version
Meidan, R. ; Girsh, E. ; Mamluk, R. ; Levy, N. ; Farberov, S. Luteolysis in ruminants: Past concepts, new insights, and persisting challenges. In The Life Cycle of the Corpus Luteum; The Life Cycle of the Corpus Luteum; 2016; pp. 159 - 182. Publisher's Version
Meidan, R. The life cycle of the corpus luteum; The Life Cycle of the Corpus Luteum; 2016; pp. 1 - 283. Publisher's Version
Shaani, Y. ; Eliyahu, D. ; Mizrahi, I. ; Yosef, E. ; Ben-Meir, Y. ; Nikbachat, M. ; Solomon, R. ; Mabjeesh, S. ; Miron, J. Effect of feeding ensiled mixture of pomegranate pulp and drier feeds on digestibility and milk performance in dairy cows. Journal of Dairy Research 2016, 83, 35 - 41. Publisher's Version
Yom-Din, S. ; Hollander-Cohen, L. ; Aizen, J. ; Boehm, B. ; Shpilman, M. ; Golan, M. ; Hurvitz, A. ; Degani, G. ; Levavi-Sivan, B. Gonadotropins in the Russian sturgeon: Their role in steroid secretion and the effect of hormonal treatment on their secretion. PLoS ONE 2016, 11. Publisher's Version
Yasur-Landau, D. ; Jaffe, C. L. ; David, L. ; Baneth, G. Allopurinol Resistance in Leishmania infantum from Dogs with Disease Relapse. PLoS Neglected Tropical Diseases 2016, 10. Publisher's Version
Wein, Y. ; Barshira, E. ; Friedman, A. Avoiding handling-induced stress in poultry: use of uniform parameters to accurately determine physiological stress. Poultry Scienceps 2016, 96, 65 - 73. Publisher's VersionAbstract
Due to increase in awareness of poultry welfare and concomitant legislation, it has become necessary to determine poultry's response to stress, with minimal harm and maximum reliability. Several methods to determine the response to physiological stress were developed throughout the years to identify stressors and to measure stress in poultry. The most commonly used are plasma corticosterone levels and peripheral blood heterophil/lymphocyte ratio (H/L ratio). However, the value of these responses to determine a state of stress has been questioned in several instances, as these parameters are increased during the process of bird handling and blood sampling irrespective of the general state of stress. Due to these limitations, it appears that the classic stress markers might be sub-optimal in evaluating stress in poultry, particularly those encountered in high-stress environments. Thus, there is a continuing need for stress indicators, preferably indicators that are quantitative, highly repeatable, not influenced by handling and sampling, determined in peripheral blood, represent an initial response to the stressor, and do not daily fluctuate. As the immune system has been shown to rapidly respond to stress, we assessed pro-inflammatory gene expression in peripheral blood cells as an indicator for stress. We initially show that while corticosterone plasma levels and the H/L ratio were responsive to handling and blood sampling, pro-inflammatory gene expression (lysozyme, IL-1β, IL-6, and HSP-70) was not. We then determined the expression of the same pro-inflammatory genes during acute stress (transit) in layer pullets (hen and turkey) and during chronic stress (different caging densities of layers utilizing 2, 3, and 4 hens/cage). While gene expression was significantly and highly elevated during transit, the effect of differing caging densities on gene expression was minimal; collectively, this might indicate that expression of pro-inflammatory genes is more responsive to acute stress than to chronic stressors. We propose to use pro-inflammatory gene expression in peripheral blood cells to measure responses to stress in poultry.
Vetter, W. ; Ulms, K. ; Wendlinger, C. ; van Rijn, J. Novel non-methylated furan fatty acids in fish from a zero discharge aquaculture system. 2016, 2 8 - 14. Publisher's VersionAbstract
BackgroundFuran fatty acids (F-acids) are valuable minor fatty acids which are appraised for their protective role against lipid oxidation of polyunsaturated fatty acids (PUFAs). The most relevant dietary source for F-acids is fish with the predominant occurrence of up to five dimethyl- or monomethyl-substituted homologues. During the screening of fish from a zero discharge aquaculture (ZDA) system we noted the potential presence of unusual F-acids. Methods We developed a method by gas chromatography with mass spectrometry operated in the selected ion monitoring mode for elucidation of the structures of the uncommon F-acids. Results Carp from the ZDA system contained seven non-methylated F-acids with dominance of 8-(5-hexylfuran-2-yl)-octanoic acid (8F6). Non-methylated F-acids have never been detected before in fish. Subsequent analysis of other fish species and a batch of the fish feed confirmed the presence of non-methylated F-acids. Conclusions F-acids in fish are derived from the feed. Our investigation indicates that more emphasis should be put on the F-acid concentrations in fish from aquaculture, which appears to depend on the quality of the fish feed.
Rakovitsky, N. ; Brook, I. ; van Rijn, J. ; Ryskin, M. ; Mkhweli, Z. ; Etkin, H. ; Nir, S. Purification of greywater by a moving bed reactor followed by a filter including a granulated micelle-clay composite. 2016, 132-133, 267 - 272. Publisher's VersionAbstract
Reuse of grey water (GW) enables to reduce fresh water consumption, but a treatment is required to prevent potential transmission and propagation of pathogenic organisms. This study presents results on the removal of pathogenic bacteria from GW as well as reduction of turbidity, TSS COD, and BOD by a novel treatment system. Compared to previous studied methods, three new elements are presented in the current treatment of GW: (1) A granulated complex of micelles of the organic cation octadecyltrimethylammonium (ODTMA) with montmorillonite was employed in filtration of GW. This complex was efficient in purifying GW due to its large surface area, positive charge and existence of hydrophobic domains. The granulated complex enabled flow when present exclusively in the filter; (2). A moving bed reactor for decomposition of part of the organic matter in the GW. This pretreatment stage, prior to the micelle-clay filter, was also efficient in removing pathogenic bacteria; (3) A regeneration stage of the micelle-clay filter conducted by passing either dilute solutions of Na-hypochlorite or HCl through the micelle-clay complex, or by heating the complex. Incubation of GW for either two weeks or one day in the pretreatment stage yielded a 10- and 7-fold enhancement in the volume filtered, which did not contain fecal coliforms, i.e., 300 and 210L for 40g of complex, respectively. The capacity of purified volume per gram of the complex increased further several-fold (>23L/g) for filters filled exclusively with granules. Regeneration of the complex in the filter further enhanced the capacity.
Rozenboim, I. ; Mahato, J. ; Cohen, N. A. ; Tirosh, O. Low protein and high-energy diet: a possible natural cause of fatty liver hemorrhagic syndrome in caged White Leghorn laying hens. Poultry Scienceps 2016, 95, 612 - 621. Publisher's VersionAbstract
Fatty liver hemorrhagic syndrome (FLHS) is a metabolic condition of chicken and other birds caused by diverse nutritional, hormonal, environmental, and metabolic factors. Here we studied the effect of different diet composition on the induction of FLHS in single comb White Leghorn (WL) Hy-line laying hens. Seventy six (76) young WL (26 wks old) laying hens and 69 old hens (84 wks old) of the same breed were each divided into 4 treatment groups and provided 4 different diet treatments. The diet treatments included: control (C), 17.5% CP, 3.5% fat (F); normal protein, high fat (HF), 17.5% CP, 7% F; low protein, normal fat (LP), 13% CP, 3.5% F; and low protein, high fat (LPHF), 13% CP, 6.5% F. The diets containing high fat also had a higher ME of 3,000 kcal/kg of feed while the other 2 diets with normal fat had a regular lower amount of ME (2750 kcal/kg). Hen-day egg production (HDEP), ADFI, BW, egg weight, plasma enzymes indicating liver damage (alkaline phosphatase [ALP], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT]), liver and abdominal fat weight, liver color score (LCS), liver hemorrhagic score (LHS), liver fat content (LFC), liver histological examination, lipid peroxidation product in the liver, and genes indicating liver inflammation were evaluated. HDEP, ADFI, BW, and egg weight were significantly decreased in the LPHF diet group, while egg weight was also decreased in the LP diet group. In the young hens (LPHF group), ALP was found significantly higher at 30 d of diet treatment and was numerically higher throughout the experiment, while AST was significantly higher at 105 d of treatment. LCS, LHS, and LFC were significantly higher in young hens on the LPHF diet treatment. A liver histological examination shows more lipid vacuolization in the LPHF treatment diet. HF or LP alone had no significant effect on LFC, LHS, or LCS. We suggest that LP in the diet with higher ME from fat can be a possible natural cause for predisposing laying hens to FLHS.
Kamkrathok, B. ; Sartsoongnoen, N. ; Prakobsaeng, N. ; Rozenboim, I. ; Porter, T. E. ; Chaiseha, Y. Distribution of hypothalamic vasoactive intestinal peptide immunoreactive neurons in the male native Thai chicken. 2016, 171, 27 - 35. Publisher's VersionAbstract
Avian prolactin (PRL) secretion is under stimulatory control by the PRL-releasing factor (PRF), vasoactive intestinal peptide (VIP). The neuroendocrine regulation of the avian reproductive system has been extensively studied in females. However, there are limited data in males. The aim of this study was to elucidate the VIPergic system and its relationship to PRL and testosterone (T) in the male native Thai chicken. The distributions of VIP-immunoreactive (-ir) neurons and fibers were determined by immunohistochemistry. Changes in VIP-ir neurons within the nucleus inferioris hypothalami (IH) and nucleus infundibuli hypothalami (IN) areas were compared across the reproductive stages. Plasma levels of PRL and T were determined by enzyme-linked immunosorbent assay and then compared across the reproductive stages. The results revealed that the highest accumulations of VIP-ir neurons were concentrated only within the IH-IN, and VIP-ir neurons were not detected within other hypothalamic nuclei. Within the IH-IN, VIP-ir neurons were low in premature and aging males and markedly increased in mature males. Changes in VIP-ir neurons within the IH-IN were directly mirrored with changes in PRL and T levels across the reproductive stages. These results suggested that VIP neurons in the IH-IN play a regulatory role in year-round reproductive activity in males. The present study also provides additional evidence that VIP is the PRF in non-seasonal, continuously breeding equatorial species.
Roth, Z. ; Asaf, S. ; Furman, O. ; Lavon, Y. ; Kalo, D. ; Wolfenson, D. ; Leitner, G. Subclinical mastitis disrupts oocyte cytoplasmic maturation in association with reduced developmental competence and impaired gene expression in preimplantation bovine embryos. Reproduction, Fertility and Development 2016, 28, 1653 - 1662. Publisher's VersionAbstract
Subclinical chronic mastitis was induced to examine the effects on oocyte developmental competence. Uninfected Holstein cows were intramammary administrated with serial (every 48 h for 20 days) low doses of toxin of Staphylococcus aureus origin (Gram-positive; G+), endotoxin of Escherichia coli origin (Gram-negative; G–) or sterile saline (control). Follicular fluid of toxin- and saline-treated cows was aspirated from preovulatory follicles and used as maturation medium. Oocytes harvested from ovaries collected at the abattoir were matured and then fertilised and cultured for 8 days. The percentage of oocytes undergoing nuclear maturation, determined by meiotic nuclear stages, did not differ between groups. Cytoplasmic maturation, determined by cortical granule distribution, was affected by both toxins (P < 0.05). The percentage of oocytes cleaving to 2- and 4-cell embryos and of embryos developing to the blastocyst stage was lower in both toxin-treated groups than in the control group (P < 0.05). There was no significant difference in the total cell number in Day 8 blastocysts among the groups; however, the apoptotic index was higher in both toxin-treated groups compared with control (P < 0.05). The relative abundance of prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclo-oxygenase; PTGS2) mRNA increased, whereas that of growth differentiation factor 9 (GDF9) decreased in matured oocytes. In addition, PTGS2 expression increased and POU class 5 homeobox 1 (POU5F1) expression decreased in 4-cell embryos developed from both G+ and G– oocytes. Thus, regardless of toxin type, subclinical mastitis disrupts oocyte cytoplasmic maturation and alters gene expression in association with reduced developmental competence.
Roth, Z. ; Wolfenson, D. Comparing the effects of heat stress and mastitis on ovarian function in lactating cows: basic and applied aspects. 8th International Conference on Farm Animal Endocrinology 2016, 56, S218 - S227. Publisher's VersionAbstract
Reduced reproductive performance of lactating cows is strongly associated with environmental and pathogenic stressors. This review summarizes the most recent knowledge on the effects of acute or chronic heat stress (HS) and acute or chronic intramammary infection (IMI) on ovarian function. It also offers various approaches for improving the fertility of cows under chronic HS or IMI. Comparing the 2 stressors reveals a few similarities in the mode of alteration in the hypothalamus–pituitary–ovarian axis, in particular, in the follicle and its enclosed oocyte. Both HS and IMI cause a reduction in the preovulatory LH surge, with a pronounced effect in cows with IMI, and consequently, ovulation is being delayed or inhibited. Both stresses induce changes in follicular growth dynamics, reduce follicular steroidogenesis, and disrupt follicular dominance. Unlike their effects on follicular function, the effects of mastitis and HS on corpus luteum (CL) function are debatable. Under chronic summer thermal stress, several, but not all, studies show reduced progesterone secretion by the CL. Subclinical mastitis does not affect CL function, whereas the effect of clinical mastitis is controversial; some show a reduction in progesterone, whereas others do not. Both stresses have been found to impair cytoplasmic and nuclear maturation of oocytes, associated with reduced embryonic development. These findings have provided insights into the mechanism by which HS and IMI compromise fertility, which enable developing new strategies to mitigate these effects. For instance, treatment with GnRH and PGF2α to induce follicular turnover successfully improved conception rate in subpopulations of HS cows during the summer, in particular, primiparous cows and cows with high BCS. The “Ovsynch” program, also based on the use of GnRH and PGF2α, has been shown to improve conception rate of subclinical mastitic cows, most likely due to better synchronization of timing of ovulation with that of AI. Supplementing progesterone after AI improves conception rate of HS cows, particularly those with postpartum uterine disease and low BCS. It should be noted that similarities between the 2 stressors do not necessarily suggest a shared mechanism. Although not clear enough, an additive deleterious effects of HS and IMI on reproduction is suggested.
Ortega, M. S. ; Rocha-Frigoni, N. A. S. ; Mingoti, G. Z. ; Roth, Z. ; Hansen, P. J. Modification of embryonic resistance to heat shock in cattle by melatonin and genetic variation in HSPA1L. 2016, 99, 9152 - 9164. Publisher's VersionAbstract
The objectives were to test whether (1) melatonin blocks inhibition of embryonic development caused by heat shock at the zygote stage, and (2) the frequency of a thermoprotective allele for HSPA1L is increased in blastocysts formed from heat-shocked zygotes as compared with blastocysts from control zygotes. It was hypothesized that melatonin prevents effects of heat shock on development by reducing accumulation of reactive oxygen species (ROS) and that embryos inheriting the thermoprotective allele of HSPA1L would be more likely to survive heat shock. Effects of 1 µM melatonin on ROS were determined in experiments 1 and 2. Zygotes were cultured at 38.5 or 40°C for 3 h in the presence of CellROX reagent (ThermoFisher Scientific, Waltham, MA). Culture was in a low [5% (vol/vol)] oxygen (experiment 1) or low or high [21% (vol/vol)] oxygen environment (experiment 2). Heat shock and high oxygen increased ROS; melatonin decreased ROS. Development was assessed in experiments 3 and 4. In experiment 3, zygotes were cultured in low oxygen ± 1 µM melatonin and exposed to 38.5 or 40°C for 12 h (experiment 1) beginning 8 h after fertilization. Melatonin did not protect the embryo from heat shock. Experiment 4 was performed similarly except that temperature treatments (38.5 or 40°C, 24 h) were performed in a low or high oxygen environment (2×2 × 2 factorial design with temperature, melatonin, and oxygen concentration as main effects), and blastocysts were genotyped for a deletion (D) mutation (C→D) in the promoter region of HSPA1L associated with thermotolerance. Heat shock decreased percent of zygotes developing to the blastocyst stage independent of melatonin or oxygen concentration. Frequency of genotypes for HSPA1L was affected by oxygen concentration and temperature, with an increase in the D allele for blastocysts that developed in high oxygen and following heat shock. It was concluded that (1) lack of effect of melatonin or oxygen concentration on embryonic development means that the negative effects of heat shock on the zygote are not mediated by ROS, (2) previously reported effect of melatonin on fertility of heat-stressed cows might involve actions independent of the antioxidant properties of melatonin, and (3) the deletion mutation in the promoter of HSPA1L confers protection to the zygote from heat shock and high oxygen. Perhaps, embryonic survival during heat stress could be improved by selecting for thermotolerant genotypes.
Farberov, S. ; Meidan, R. Thrombospondin-1 Affects Bovine Luteal Function via Transforming Growth Factor-Beta1-Dependent and Independent Actions1. Biology of Reproductionbiolreprod 2016, 94. Publisher's VersionAbstract
Thrombospondin-1 (THBS1) and transforming growth factor-beta1 (TGFB1) are specifically up-regulated by prostaglandin F2alpha in mature corpus luteum (CL). This study examined the relationship between the expression of THBS1 and TGFB1 and the underlying mechanisms of their actions in luteal endothelial cells (ECs). TGFB1 stimulated SMAD2 phosphorylation and SERPINE1 levels in dose- and time-dependent manners in luteal EC. THBS1 also elevated SERPINE1; this effect was abolished by TGFB1 receptor-1 kinase inhibitor (SB431542). The findings here further imply that THBS1 activates TGFB1 in luteal ECs: THBS1 increased the effects of latent TGFB1 on phosphorylated SMAD (phospho-SMAD) 2 and SERPINE1. THBS1 silencing significantly decreased SERPINE1 and levels of phospho-SMAD2. Lastly, THBS1 actions on SERPINE1 were inhibited by LSKL peptide (TGFB1 activation inhibitor); LSKL also counteracted latent TGFB1-induced phospho-SMAD2. We found that TGFB1 up-regulated its own mRNA levels and those of THBS1. Both compounds generated apoptosis, but THBS1 was significantly more effective (2.5-fold). Notably, this effect of THBS1 was not mediated by TGFB1. THBS1 and TGFB1 also differed in their activation of p38 mitogen-activated protein kinase. Whereas TGFB1 rapidly induced phospho-p38, THBS1 had a delayed effect. Inhibition of p38 pathway by SB203580 did not modulate TGFB1 effect on cell viability, but it amplified THBS1 actions. THBS1-stimulated caspase-3 activation coincided with p38 phosphorylation, suggesting that caspase-induced DNA damage initiated p38 phosphorylation. The in vitro data suggest that a feed-forward loop exists between THBS1, TGFB1, and SERPINE1. Indeed all these three genes were similarly induced in the regressing CL. Their gene products can promote vascular instability, apoptosis, and matrix remodeling during luteolysis.
Casey, T. ; Crodian, J. ; Suárez-Trujillo, A. ; Erickson, E. ; Weldon, B. ; Crow, K. ; Cummings, S. ; Chen, Y. ; Shamay, A. ; Mabjeesh, S. ; et al. CLOCK regulates mammary epithelial cell growth and differentiation. American Journal of Physiology-Regulatory, Integrative and Comparative PhysiologyAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology 2016, 311, R1125 - R1134. Publisher's VersionAbstract
Circadian clocks influence virtually all physiological processes, including lactation. Here, we investigate the role of the CLOCK gene in regulation of mammary epithelial cell growth and differentiation. Comparison of mammary morphology in late-pregnant wild-type and Clock?19 mice, showed that gland development was negatively impacted by genetic loss of a functional timing system. To understand whether these effects were due, in part, to loss of CLOCK function in the gland, the mouse mammary epithelial cell line, HC11, was transfected with short hairpin RNA that targeted Clock (shClock). Cells transfected with shClock expressed 70% less Clock mRNA than wild-type (WT) HC11 cultures, which resulted in significantly depressed levels of CLOCK protein (P < 0.05). HC11 lines carrying shClock had four-fold higher growth rates (P < 0.05), and the percentage of cells in G1 phase was significantly higher (90.1 ± 1.1% of shClock vs. 71.3 ± 3.6% of WT-HC11) following serum starvation. Quantitative-PCR (qPCR) analysis showed shClock had significant effects (P < 0.0001) on relative expression levels of Ccnd1, Wee1, and Tp63. qPCR analysis of the effect of shClock on Fasn and Cdh1 expression in undifferentiated cultures and cultures treated 96 h with dexamethasone, insulin, and prolactin (differentiated) found levels were reduced by twofold and threefold, respectively (P < 0.05), in shClock line relative to WT cultures. Abundance of CDH1 and TP63 proteins were significantly reduced in cultures transfected with shClock. These data support how CLOCK plays a role in regulation of epithelial cell growth and differentiation in the mammary gland.Circadian clocks influence virtually all physiological processes, including lactation. Here, we investigate the role of the CLOCK gene in regulation of mammary epithelial cell growth and differentiation. Comparison of mammary morphology in late-pregnant wild-type and Clock?19 mice, showed that gland development was negatively impacted by genetic loss of a functional timing system. To understand whether these effects were due, in part, to loss of CLOCK function in the gland, the mouse mammary epithelial cell line, HC11, was transfected with short hairpin RNA that targeted Clock (shClock). Cells transfected with shClock expressed 70% less Clock mRNA than wild-type (WT) HC11 cultures, which resulted in significantly depressed levels of CLOCK protein (P < 0.05). HC11 lines carrying shClock had four-fold higher growth rates (P < 0.05), and the percentage of cells in G1 phase was significantly higher (90.1 ± 1.1% of shClock vs. 71.3 ± 3.6% of WT-HC11) following serum starvation. Quantitative-PCR (qPCR) analysis showed shClock had significant effects (P < 0.0001) on relative expression levels of Ccnd1, Wee1, and Tp63. qPCR analysis of the effect of shClock on Fasn and Cdh1 expression in undifferentiated cultures and cultures treated 96 h with dexamethasone, insulin, and prolactin (differentiated) found levels were reduced by twofold and threefold, respectively (P < 0.05), in shClock line relative to WT cultures. Abundance of CDH1 and TP63 proteins were significantly reduced in cultures transfected with shClock. These data support how CLOCK plays a role in regulation of epithelial cell growth and differentiation in the mammary gland.