Feeding rumen-protected methionine during the peripartum period improved milk fat content and reduced the culling rate of Holstein cows in a commercial herd

Researchers have reported the benefits of feeding rumen-protected methionine (RPM) during the peripartum on the health parameters of dairy cows. Rumen-protected methionine has reportedly improved milk yield, milk components and liver health, but the literature is scarce on its effects in commercial herds. Therefore, we aimed to determine the effects of feeding RPMet (Smartamine M®, Adisseo Inc., Antony, France) prepartum (8 g per cow per day) and postpartum (15 g per cow per day) on performance, metabolic profile, and culling rate of Holstein cows in a commercial herd. One-hundred and 66 (n = 166) Holstein cows, 58 nulliparous and 108 parous, were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPMet (2.35 and 2.24% Met of MP for close-up and fresh cows, respectively) or without (control, CON, (2.03 and 1.89% Met of MP for close-up and fresh cows, respectively), fed from 21 ± 6 d prepartum until 16 ± 5 d postpartum. From 17 d in milk (DIM) until dry-off, all cows received RPMet. Daily milk yield was recorded, and milk samples were collected in the first and second weeks after calving to determine their composition. Blood samples were collected before the morning feeding on -14, -7, +1, +7, and +14 d relative to calving. Mortality and morbidity were recorded during the first 60 DIM. Cows supplemented with RPMet had greater milk yield during the first 16 DIM (31.76 vs. 30.37 kg/d; SEM = 1.04, respectively), and had greater milk fat content (4.45 vs. 4.10%; SEM = 0.11, respectively), but not milk total protein (3.47 vs. 3.39%; SEM = 0.04, respectively) and casein contents (2.74 vs. 2.66%; SEM = 0.04, respectively) than CON cows. Cows in RPMet had increased plasma Met concentrations than cows in CON (24.9 vs. 21.0 µmol/L; SEM = 1.2, respectively). Although morbidity was similar between treatments, the culling rate from calving until 60 DIM was lower for RPMet cows than for CON cows (2.4 vs. 12.1%; SEM = 0.02). In conclusion, cows receiving RPMet have greater milk yield, improved milk fat content, and a lower culling rate at 60 DIM than CON cows.

Butyrate supplementation in the liquid diet of dairy calves leads to a rapid recovery from diarrhea and reduces its occurrence and relapses in the preweaning period

The present study aimed to evaluate the effect of continuous butyrate administration in dairy calves' liquid diet considering diarrhea, metabolic profile, gastrointestinal development, and corporal growth. Immediately after birth, calves were randomly allocated into 2 groups of 62 calves (50 females and 12 males), with access to water and a solid feed ad libitum. The butyrate group (BG) received 4 g/d of sodium butyrate (Admix Easy, Adisseo) diluted in the whole milk, and the control group (CG) received whole milk with no supplementation. Sodium butyrate was administered from d 1 of life until the weaning at 90 d. Feces consistency was assessed daily for the first 30 d of life and characterized by scores from 0 to 4 (0 and 1 for normal, and 2, 3, and 4 for abnormal feces). Diarrhea was diagnosed when the animals had abnormal feces and fever. Morbidity, recurrence, mortality, and lethality data were recorded and compared between the groups. Average daily gain (ADG) and corporal growth (body weight, thoracic perimeter, height at the withers, and croup width) were evaluated weekly, from the first day to d 30, and later at 45, 60, and 90 d of life. Blood samples were taken weekly for up to 30 d to determine the circulating levels of total calcium, phosphorus, chloride, bicarbonate, glucose, β-hydroxybutyrate, and nonesterified fatty acids. The males were euthanized at 15 (n = 6 per group) and 30 d (n = 6 per group) for morphometric, histological, and gene expression analysis of the gastrointestinal tract. The results showed that the BG had a lower rate of morbidity (BG = 30% vs. CG = 50%) and recurrence (BG = 26.7% vs. CG = 60%) of diarrhea than the CG. In addition, the BG had abnormal feces for a shorter period (BG = 4.64 ± 0.47 d vs. CG = 8.6 ± 0.65 d). The ADG tended to be higher in BG than CG up to 30 and 60 d. Metabolic evaluations showed the lowest levels of glucose and highest levels of nonesterified fatty acids in BG. On d 30 of life, rumen papillae length, papilla area, duodenum villus length, and crypt depth were higher in BG than in CG. The duodenal gene expression at 30 d showed that animals with diarrhea episodes that did not receive butyrate had the highest levels of transcripts for the LCT and GLP2 genes. In addition, in different ways, both butyrate and neonatal diarrhea affected the gene expression of IGF1, SLC5A1, and AQP3. These results allow us to conclude that continuous supplementation with sodium butyrate improves gastrointestinal development, reduces the occurrence of diarrhea, and makes clinical conditions milder with faster recovery, favoring a higher ADG in the first 30 and 60 d of life. Based on these results, we conclude that sodium butyrate can be indicated for liquid diet supplementation to accelerate gastrointestinal tract development and prevent severe cases of neonatal diarrhea, tending to improve average daily gain until weaning.

Nature-Based Early Childhood Education and Children's Physical Activity, Sedentary Behavior, Motor Competence, and Other Physical Health Outcomes: A Mixed-Methods Systematic Review

BACKGROUND

The purpose was to synthesize evidence on the association between nature-based Early Childhood Education (ECE) and children's physical activity (PA) and motor competence (MC).

METHODS

A literature search of 9 databases was concluded in August 2020. Studies were eligible if (1) children were aged 2-7 years old and attending ECE, (2) ECE settings integrated nature, and (3) assessed physical outcomes. Two reviewers independently screened full-text articles and assessed study quality. Synthesis was conducted using effect direction (quantitative), thematic analysis (qualitative), and combined using a results-based convergent synthesis.

RESULTS

1370 full-text articles were screened and 39 (31 quantitative and 8 qualitative) studies were eligible; 20 quantitative studies assessed PA and 6 assessed MC. Findings indicated inconsistent associations between nature-based ECE and increased moderate to vigorous PA, and improved speed/agility and object control skills. There were positive associations between nature-based ECE and reduced sedentary time and improved balance. From the qualitative analysis, nature-based ECE affords higher intensity PA and risky play, which could improve some MC domains. The quality of 28/31 studies was weak.

CONCLUSIONS

More controlled experimental designs that describe the dose and quality of nature are needed to better inform the effectiveness of nature-based ECE on PA and MC.

A11 ISOLATION OF NON-POLAR METABOLITES IN EXCRETORY/SECRETORY PRODUCTS FROM PARASITIC HELMINTHS AND THEIR POTENTIAL AS IMMUNOTHERAPY IN INFLAMMATORY BOWEL DISEASE

Background

Parasitic helminths are known to modulate host immune responses. This is thought to be mediated by their secretome. We are interested in the excretory/secretory products and mechanisms for modulating immune dysfunction in autoinflammatory diseases.

Aims

This research studies the mechanisms of immune modulation by parasitic helminths in the context of IBD. We aim to describe immunomodulatory helminth-derived metabolites (ESM).

Methods

Helminth-conditioned media was used to isolate ESM, which were further purified using column chromatography.

Bone marrow (BM) derived macrophages (BMDM) from C57BL6 mice, were treated with ESP fractions from Trichuris suis, Ascaris suum, Heligmosomoides polygyrus bakeri or Dirofilaria immitis, stimulated with LPS, and secreted cytokine levels measured. Moreover, BM was cultured with or without ESM throughout differentiation to BMDM.

Colitic mice (3% DSS, 5 days) were treated with A. suum ESM or PBS once daily IP. Colon lengths and TNFα mRNA were measured, and histological preparations were scored to assess pathology.

Bioactive D. immitis ESM were fractionated using preparatory HPLC and assayed for bioactivity. Active fractions were analysed using MS/MS and fragmentation patterns and molecular weights were obtained. The active fractions are currently being studied by NMR to deduce a structure of an active metabolite.

Results

BMDM treated with crude ESM decreased TNFα secretion and increased IL-10. BMDM precursors which were treated with A. suum ESM throughout differentiation had reduced proliferation in a dose dependent manner. These BMDM showed remodeling of BMDM metabolic pathways. Intracellular ROS production was inversely proportional to Alamar blue oxidation.

We found that ESM from A. suum improved DSS-colitis. Specifically, mice with DSS-induced colitis given IP ESM had longer colons, lower histolopathology score, and lower TNFα mRNA expression in gut tissue.

HPLC-fractionated D. immitis ESM used to treat BMDM yielded varying suppression of TNFα with LPS stimulation. MS/MS of TNFα suppressive fractions contained masses with fragmentation patterns which were detected in fractions of several of the above-mentioned parasite species. Preliminary NMR studies will determine if this represents a conserved structure.

Conclusions

Helminth-derived components can immunologically polarize a response in vitro, as well as favour recovery in DSS colitis. Through multiple purification steps, a nearly pure fraction is found to have bioactivity, suggesting a single, bioactive molecule that is conserved across several parasitic helminths. These data are important in understanding the host-parasite interaction modulated by ESM, as well as provide therapeutic potential in IBD.

Funding Agencies

NSERC, FRQNT

A4 HELMINTH-DERIVED METABOLITES INDUCE A TOLEROGENIC PROFILE IN DENDRITIC CELLS AND ALLEVIATE EXPERIMENTAL COLITIS

Background

Inflammatory bowel diseases (IBD) are chronic inflammatory diseases characterized by abdominal pain, bloody diarrhea, fatigue, weight loss, and diminished quality of life. The morbidity associated with IBD is a result of loss of tolerance towards the gastrointestinal commensal microbiota. The high incidence of IBD in Western societies is inversely correlated with the low incidence of intestinal helminth parasite infections, potentially due to the ability of the helminth parasite to induce tolerance by inducing tolerogenic dendritic cells (tolDC) polarization. Although macromolecules from helminth such as proteins and polysaccharides have been shown to polarize tolDCs, to characterize a novel pathway, in this study we focused on small molecules such as metabolites in the helminth secretome. We hypothesized that helminth-derived metabolites (HDMs) polarize DCs towards a tolerogenic phenotype, which alleviates colitis.

Aims

To evaluate and characterize the tolerogenic response induced by HDMs in DCs, and its ability to alleviate colitis.

Methods

Heligmosomoides polygyrus worms were culture for 24 h and HDMs were isolated from conditioned media by chromatography. Bone marrow dendritic cells (BMDCs) were differentiated with GM-CSF for 8 days and then incubated with HDM for 4 h before LPS stimulation for 20 h. Cytokine secretion was measured by ELISA. The transcriptome of DCs treated with HDMs was assessed by RNAseq. Colitis was induced by giving 3% DSS in drinking water for 5 days followed by 3 days of tap water. The anti-colitic effect of HDMs was assessed by daily treatment with HDM or DCs treated with HDM in the 3 days of tap water.

Results

Pre-treatment with HDM decreased LPS-induced TNF and increased IL-10 release by BMDCs, compared to control BMDCs. Colitic mice treated with HDM presented lower disease activity scores, less colon shortening, decreased weight loss, and healthier histopathology compared to vehicle-treated colitic mice. Importantly, there was an increased frequency of CD11c+ CD103+ DCs in the colon of HDM-treated mice, suggesting that HDM alleviates colitis by increasing the abundance of tolDCs in the colon. Adoptive transfer of HDM-treated DCs also reduced the severity of colitis compared with vehicle-treated mice or mice that received naïve DCs. These results indicate that HDM induced tolerogenic DCs, which in turn ameliorates DSS colitis. RNAseq showed that HDM upregulated 183 and downregulated 76 genes. These differentially expressed genes may indicate a novel mechanism by which helminths induce a tolerogenic profile in DCs.

Conclusions

HDMs induce tolerogenic DCs and alleviate DSS-induced colitis.

Funding Agencies

NSERC and FRQNT

A44 PGC1-α INHIBITION WORSENS DSS-INDUCED COLITIS IN MICE

Background

Inflammatory bowel diseases (IBD) represent a wide range of gastrointestinal diseases that are characterized by chronic inflammation of the gastrointestinal tract (GIT). Affecting more than 6 million individuals globally, the most prevalent forms of IBD are Ulcerative colitis (UC), characterized by inflammation and ulceration of the colon and rectum, and Crohn’s disease (CD), characterized by inflammation of several areas of the GIT. Due to the morbidity and occasionally mortality arising from IBD, as well as its increasing global prevalence, the search for novel treatments and cures for IBD presents great importance. Loss of immune tolerance significantly contributes to the inflammatory patterns observed in IBD patients. Dendritic Cells (DCs), key antigen-presenting cells, are important mediators of tolerance in the gut when polarized to tolerogenic DCs (tolDCs). The phenotype of tolDCs has been shown to directly depend on their intracellular metabolism, mostly by adopting mitochondrial oxidative phosphorylation. Peroxisome proliferator-activated receptor-gamma coactivator (PGC)1-α is a transcription coactivator that plays a crucial role in mediating cellular energy metabolism. Evidence shows that activation of PGC1-α stimulates mitochondrial biogenesis and promotes oxidative metabolism in a variety of biological processes.

Aims

The aim of this project was to evaluate whether activation or inhibition of PGC1-α impacts inflammatory response in DSS-induced colitic in mice. We hypothesize that the PGC1-α pharmacological activator ZLN005 would ameliorate colitis as a result of tolDC polarization. On other hand, the PGC1-α pharmacological inhibitor SR18292 would increase inflammatory responses and decrease tolerance.

Methods

C57/b6 mice received DSS in drinking water for 5 days, followed by 3 days of tap water. Mice were treated with vehicle, ZLN005 (10 mg/kg), or SR18292 treatment (25 mg/kg) for the 3 days of drinking tap water. Under necropsy, colitis was assessed by disease activity score (DAS), colon length, weight change, myeloperoxidase (MPO) activity assay, histopathology score, and cytokines by ELISA. Intestinal tolerance was accessed by evaluating T cells polarization to Treg, TH1, TH2, or TH17 by qPCR of the transcription factors Foxp3 (Treg), Tbx21 (TH1), Gata3 (TH2), and Rorγt (TH17) expressed in the colon.

Results

Our results demonstrated that ZLN005 did not alter the inflammatory response induced by DSS, gauged by MPO assay, DAS, and histopathology, suggesting that ZLN005 was ineffective in polarizing tolDCs. However, we observed a worsening of inflammatory conditions with treatment with SR18292 with a decrease in IL-10 levels and increased MPO values, potentially stemming from the loss of tolDCs and intestinal tolerance.

Conclusions

PGC1-α inhibition worsens inflammatory response in DSS-induced colitis potentially by inhibiting tolDC polarization and loss of intestinal tolerance.

Funding Agencies

None

A41 THE ROLE OF PGC-1α IN MURINE BONE MARROW DENDRITIC CELLS

Background

The intestinal immune system tolerates food antigens and the commensal microbiota to prevent chronic inflammation. Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn’s disease, are characterized by the loss of tolerance towards the microbiota, leading to inflammation, which is characterized by the high production of cytokines such as TNF and the influx of macrophages and neutrophils to the gut. Tolerance is driven by tolerogenic dendritic cells (tolDCs). Currently, there is no cure for IBD and while available treatments may reduce symptoms, there are no pharmacological therapies that specifically seek to rescue tolerance. Inducing tolDCs in patients with IBD may be a promising therapy since it is a way to directly target the main cause of the disease. tolDCs have been defined by down-regulating TNF (pro-inflammatory cytokine), producing IL-10 (anti-inflammatory cytokine), and active oxidative phosphorylation (OXPHOS) in the mitochondria.

Aims

Given the tolDC characteristic of active OXPHOS, the objective of our project was to evaluate the role of PGC-1α, a major mediator of mitochondria biogenesis, in generating toDCs using murine bone marrow-derived dendritic cells (BMDC). Our hypothesis is that tolDCs would be (1) generated by pharmacological activation of PGC-1α by ZLN005, and (2) constrained by inhibition of PGC-1α by SR18292.

Methods

We treated BMDC cultures with ZLN005 (PGC-1α activator) or SR18292 (PGC-1α inhibitor), and LPS. We characterized the effect of PGC-1α manipulation on the metabolism of BMDCs by metabolomics and Seahorse XF Cell Mito Stress Test. In addition, we evaluated features of tolDCs, such as gene expression by qPCR, and cytokine production by ELISA.

Results

We observed that activation of PGC-1α altered the metabolic profile of BMDC, and upregulates genes known to be expressed in tolDCs. However, this transcriptional upregulation was lost after LPS stimulation and did not alter TNF or IL-10 levels in BMDCs. PGC-1α inhibition, on other hand, decreased features of tolDCs, such as metabolic profile, transcriptional activation, and the levels of LPS-induced IL-10. Our data suggest that PGC-1α activation with ZLN005 does not increase the generation of tolDCs in vitro. However, inhibition of PGC-1α with SR18292 constrains tolDCs generation.

Conclusions

PGC-1α is important for the development of tolDCs in murine dendritic cells.

Funding Agencies

NSERC and FRQNT

O-190 Comparison between effects of exposure to platinum-based chemotherapeutics (cisplatin and carboplatin) on Sertoli cell number and functions in immature human testicular tissues

Study question

Does exposure to either cisplatin or carboplatin have a damaging effect on the Sertoli cell population in the immature human testicular tissues?

Summary answer

Exposure to cisplatin or carboplatin did not appear to have a major effect on Sertoli cell number or function in the immature human testicular tissues

What is known already

Long-term survival rates for children with cancer are more than 80%. However, childhood cancer treatment may result in subsequent infertility. Cisplatin is one of the most commonly used drugs for childhood cancers. Carboplatin, a second generation platinum drug, is administered at 10-times the dose of cisplatin and is believed to be less gonadotoxic. In our recent publication we have shown that exposure to both cisplatin and carboplatin acutely reduce the germ cell number in immature human testicular tissues. However, it is not known how cisplatin and carboplatin affect Sertoli cell number and function.

Study design, size, duration

In-vitro culture of human fetal and pre-pubertal testicular tissues was utilised. Tissue pieces were cultured for 1-3 days prior to exposure to clinically-relevant doses of chemotherapeutics or vehicle control for 24hrs in two sets of experiments: 1) 0.5 or 1 μg/ml cisplatin and culture ended at 24 and 96hrs post-exposure (fetal only); 2) 0.5 μg/ml cisplatin or 5 ­μg/ml carboplatin until 72 (both fetal and pre-pubertal) and 240hrs post-­exposure (fetal only).

Participants/materials, setting, methods

Testicular tissue fragments from second trimester human fetal (14-22 gestational weeks; n = 3-6) or pre-pubertal patients (1-8years old; n = 5) were cultured in a ‘hanging drop’ system.Quantification of Sertoli cell number (cells per cord/tubular area (mm2)) was performed on sections stained for expression of SOX9. Culture medium was collected to measure levels (ng/ml) of Anti-Mullerian hormone (AMH) and Inhibin B using ELISA. Statistical analysis was performed using two-way ANOVA to account for inter-individual variation between fetuses/patients.

Main results and the role of chance

Quantification of positively stained Sertoli cells showed that exposure to both doses of cisplatin had no effect on Sertoli cell number at 24 and 96hrs post-exposure. No changes in AMH and inhibin B levels were observed at these time-points. Comparison between cisplatin- or carboplatin-exposed human fetal testicular tissues showed no difference in Sertoli cell numbers at either 72hrs or 240hrs post-exposure. No difference in Sertoli cell number was observed in pre-pubertal testicular tissues exposed to either cisplatin or carboplatin at 72hrs post-exposure.

Limitations, reasons for caution

Human fetal and pre-pubertal testis tissue is of limited availability, thus, sample sizes used in this study were relatively low. ‘Hanging drop’ culture might not recapitulate all in-vivo aspects of immature testis microenvironment.

Wider implications of the findings

Exposure to cisplatin or carboplatin did not affect Sertoli cell number in the immature human testicular tissues. Taken together with our recent publication, this suggests that these two platinum-based chemotherapeutic agents cause direct damage to germ cells. Functionality of Sertoli cells in chemotherapy-exposed tissues need to be further investigated.

Trial registration number

not applicable

A52 ANALYSIS AND CHARACTERIZATION OF THE EXCRETED/SECRETED PRODUCTS OF PARASITIC HELMINTHS AS IMMUNOMODULATORS OF INFLAMMATORY BOWEL DISEASE (IBD)

Background

Parasitic helminths Trichuris suis and Ascaris suum are known to modulate host immune responses. This is thought to be mediated by the secretome, or excreted factors released by these parasites. We are interested in the excretory/secretory products (ESP, TsESP and AsESP) and mechanisms responsible for modulating immune disfunciton in autoinflammatory diseases.

Aims

This research studies the mechanisms of immune modulation by parasitic helminths in the context of IBD. We aim to describe the cellular response in vitro, as well as the systemic response in vivo, to better characterize the scope of immune modulation in ESP treatment.

Methods

ESPs were collected from T. suis or A. suum-conditioned media and proteins and metabolites were isolated.

Bone marrow (BM) derived macrophages (BMDM) from C57BL6 mice, were treated with ESP fractions, stimulated with LPS, and secreted cytokines levels measured. Alternatively, undifferentiated BM was incubated with or without metabolites throughout the process of differentiation.

Using a DSS-colitis model, mice were given 3% DSS or water, then treated with ESP or PBS once daily by IP injection. Colon lengths and TNFα mRNA levels were measured and histological preparations were scored to assess pathology.

ESP with bioactivity were selected for further HPLC analysis. Fractions were collected and assayed for bioactivity.

Results

BMDM treated with T. suis or A. suum crude ESP decreased secretion of TNFα and increased IL-10. BMDM precursors incubated with A. suum metabolites during differentiation had fewer BMDM-like cells. Cytokine analysis showed decreased TNFα secretion. Experiments with Alamar suggested that metabolites remmodelled the BMDM metabolic pathways. These effects are being explored further.

We found that metabolites released by A. suum improved DSS-colitis. Specifically, mice with DSS-induced colitis given IP metabolites had reduced colon shortening compared to PBS controls, a lower histologic damage score, as well as lower levels TNFα mRNA expression in gut epithelial cells.

HPLC showed multiple peaks from crudes analyzed at 210 nm and 280 nm. HPLC fractions used to treat BMDM yielded varying secretion of TNFα. Bioactive fractions from HPLC coincide with the UV/Vis peaks, further suggesting they could be isolated and studied for immunomodulation.

Conclusions

These data suggested that ESP contains immunomodulators that may provide lead therapeutic compounds for patients with IBD. Helminth-derived components can immunologically polarize a response in vitro, as well as alter disease recovery in DSS colitis. HPLC fractionation and biological testing suggest that a bioactive molecule can be obtained. Further analysis must be done to determine structure using mass spectrometry and NMR analysis.

Funding Agencies

Natural Sciences and Engineering Research Council of Canada (NSERC) and Fonds de recherche nature et technologies Québec (FRQNT)

Shear stress affects the architecture and cohesion of Chlorella vulgaris biofilms

The architecture of microalgae biofilms has been poorly investigated, in particular with respect to shear stress, which is a crucial factor in biofilm-based reactor design and operation. To investigate how microalgae biofilms respond to different hydrodynamic regimes, the architecture and cohesion of Chlorella vulgaris biofilms were studied in flow-cells at three shear stress: 1.0, 6.5 and 11.0 mPa. Biofilm physical properties and architecture dynamics were monitored using a set of microscopic techniques such as, fluorescence recovery after photobleaching (FRAP) and particle tracking. At low shear, biofilms cohesion was heterogeneous resulting in a strong basal (close to the substrate) layer and in more loose superficial ones. Higher shear (11.0 mPa) significantly increased the cohesion of the biofilms allowing them to grow thicker and to produce more biomass, likely due to a biological response to resist the shear stress. Interestingly, an acclimation strategy seemed also to occur which allowed the biofilms to preserve their growth rate at the different hydrodynamic regimes. Our results are in accordance with those previously reported for bacteria biofilms, revealing some general physical/mechanical rules that govern microalgae life on substrates. These results may bring new insights about how to improve productivity and stability of microalgae biofilm-based systems.

The paradox-breaking panRAF plus SRC family kinase inhibitor, CCT3833, is effective in mutant KRAS-driven cancers

BACKGROUND

KRAS is mutated in ∼90% of pancreatic ductal adenocarcinomas, ∼35% of colorectal cancers and ∼20% of non-small-cell lung cancers. There has been recent progress in targeting G12CKRAS specifically, but therapeutic options for other mutant forms of KRAS are limited, largely because the complexity of downstream signaling and feedback mechanisms mean that targeting individual pathway components is ineffective.

DESIGN

The protein kinases RAF and SRC are validated therapeutic targets in KRAS-mutant pancreatic ductal adenocarcinomas, colorectal cancers and non-small-cell lung cancers and we show that both must be inhibited to block growth of these cancers. We describe CCT3833, a new drug that inhibits both RAF and SRC, which may be effective in KRAS-mutant cancers.

RESULTS

We show that CCT3833 inhibits RAF and SRC in KRAS-mutant tumors in vitro and in vivo, and that it inhibits tumor growth at well-tolerated doses in mice. CCT3833 has been evaluated in a phase I clinical trial (NCT02437227) and we report here that it significantly prolongs progression-free survival of a patient with a G12VKRAS spindle cell sarcoma who did not respond to a multikinase inhibitor and therefore had limited treatment options.

CONCLUSIONS

New drug CCT3833 elicits significant preclinical therapeutic efficacy in KRAS-mutant colorectal, lung and pancreatic tumor xenografts, demonstrating a treatment option for several areas of unmet clinical need. Based on these preclinical data and the phase I clinical unconfirmed response in a patient with KRAS-mutant spindle cell sarcoma, CCT3833 requires further evaluation in patients with other KRAS-mutant cancers.

Effects of injectable calcitriol on mineral metabolism and postpartum health and performance in dairy cows

Objectives were to determine the effects of an injectable formulation of calcitriol on Ca concentration, risk of clinical diseases, and performance in dairy cows. Cows were blocked by lactation number (1 vs. >1) and calving sequence and, within block, assigned randomly within 6 h of calving to receive subcutaneously vehicle only (CON, n = 450) or 200 (CAL200, n = 450) or 300 μg of 1α,25-dihydroxyvitamin D₃ (CAL300, n = 450). Cows were fed the same acidogenic diet prepartum. Blood was sampled before treatment administration and again during the first 11 d postpartum and analyzed for concentrations of ionized Ca (iCa), total Ca (tCa), Mg (tMg), and P (tP), β-hydroxybutyrate, carboxylated osteocalcin (cOC), and undercarboxylated osteocalcin (uOC). Cows were evaluated for diseases in the first 60 d postpartum. Reproduction and survival were monitored for the first 300 d postpartum. Calcitriol increased concentration of blood iCa (CON = 1.12 vs. CAL200 = 1.23 vs. CAL300 = 1.27 mM), plasma tCa (CON = 2.29 vs. CAL200 = 2.44 vs. CAL300 = 2.46 mM), and plasma tP (CON = 1.72 vs. CAL200 = 2.21 vs. CAL300 = 2.28 mM), and differences were observed during the first 5 d postpartum for iCa and tCa, and the first 7 d postpartum for tP. Concentrations of tMg were lower in calcitriol-treated cows than in CON cows (CON = 0.81 vs. CAL200 = 0.78 vs. CAL300 = 0.75 mM), and differences were observed during the first 5 d postpartum. Calcitriol increased plasma concentrations of cOC (CON = 14.5 vs. CAL200 = 23.0 vs. CAL300 = 19.8 ng/mL) and uOC (CON = 1.6 vs. CAL200 = 3.4 vs. CAL300 = 2.6 ng/mL). Prevalence of subclinical hypocalcemia was less in calcitriol-treated cows (CON = 19.0 vs. CAL200 = 4.7 vs. CAL300 = 9.3%); however, benefits on health were only observed in overconditioned cows (n = 270/1,350). Calcitriol reduced incidence of retained placenta (CON = 14.3 vs. CAL200 = 5.1 vs. CAL300 = 5.9%), puerperal metritis (CON = 12.7 vs. CAL200 = 6.1 vs. CAL300 = 2.5%), and morbidity (CON = 72.1 vs. CAL200 = 57.4 vs. CAL300 = 56.9%) in cows with BCS greater than 3.50, but no benefit on health was observed in cows with BCS equal to or less than 3.50 at parturition. Milk yield did not differ among treatments. Pregnancy at first AI did not differ, but pregnancy rate after the first AI was slower for calcitriol-treated cows because of reduced insemination rate and pregnancy per AI. We found that CAL200 reduced death but increased culling in cows without calving problems. Collectively, results indicate that treatment with calcitriol at parturition was effective in improving concentrations of iCa, tCa, and tP, which reduced the risk of hypocalcemia. Pregnancy rate was reduced by calcitriol treatment, and benefits on health performance were limited to overconditioned cows. Thus, treatment of all cows is not supported, and proper identification of cohorts of cows that benefit from postpartum interventions that increase blood calcitriol or calcium is needed.

Developmental genome-wide DNA methylation asymmetry between mouse placenta and embryo

In early embryos, DNA methylation is remodelled to initiate the developmental program but for mostly unknown reasons, methylation marks are acquired unequally between embryonic and placental cells. To better understand this, we generated high-resolution DNA methylation maps of mouse mid-gestation (E10.5) embryo and placenta. We uncovered specific subtypes of differentially methylated regions (DMRs) that contribute directly to the developmental asymmetry existing between mid-gestation embryonic and placental DNA methylation patterns. We show that the asymmetry occurs rapidly during the acquisition of marks in the post-implanted conceptus (E3.5-E6.5), and that these patterns are long-lasting across subtypes of DMRs throughout prenatal development and in somatic tissues. We reveal that at the peri-implantation stages, the de novo methyltransferase activity of DNMT3B is the main driver of methylation marks on asymmetric DMRs, and that DNMT3B can largely compensate for lack of DNMT3A in the epiblast and extraembryonic ectoderm, whereas DNMT3A can only partially compensate in the absence of DNMT3B. However, as development progresses and as DNMT3A becomes the principal de novo methyltransferase, the compensatory DNA methylation mechanism of DNMT3B on DMRs becomes less effective.

Effect of different solutions in reversing the damage caused by radiotherapy in dentin structure

Background

Previous studies have shown that radiotherapy of the head and neck region can cause direct changes in dental structure. This study evaluated the effect of different solutions on the dentin chemical composition and collagen structure of irradiated dentin.

Material and Methods

Sixty maxillary canines were distributed in 2 groups (n=30): non-irradiated and irradiated (radiotherapy: X-rays of 6 MV in 30 cycles of 2 Gy to 60 Gy). The teeth were sectioned, sanded, and polished to obtain 3x3x2 mm fragments, which were redistributed in 3 subgroups (n=10) according to the treatment employed: chlorhexidine 2% (CL), chitosan 0.2% (QT), and 0.5 M carbodiimide (EDC). The samples were analyzed in FTIR at time zero (T0-control) and after 1 (T1), 3 (T3), and 5 (T5) minutes of immersion in the tested solutions. The data for the areas of the carbonate (C), amide I (AI) bands, and the ratio between the areas of the amide III/proline and hydroxyproline (AIII/PH) bands were analyzed using ANOVA and Tukey test (α=5%).

Results

QT showed lower C values at T1, T3, and T5 (P<0.0001), presenting lower values when compared to CL and EDC subgroups (P<0.05). AI values at T3 and T5 were higher than T0-control and T1, independently of the radiotherapy and dentin treatment factors (P<0.05). At T0-control, the AIII/PH ratio was lower in the irradiated group (P<0.05), whereas the EDC treatment at T1, T3, and T5 and QT at T3 and T5 increased these values (P<0.05), making them similar to non-irradiated subgroups (P>0.05).

Conclusions

Radiotherapy changes the secondary structure of collagen, and EDC was able to restore collagen integrity after 1 minute of immersion, without changing dentin inorganic composition.

Key words:Radiotherapy, collagen, dentin, FTIR, chemical composition.

Ovarian damage from chemotherapy and current approaches to its protection

BACKGROUND

Anti-cancer therapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicle reserve is extremely sensitive to the effects of chemotherapy and radiotherapy. While oocyte, embryo and ovarian cortex cryopreservation can help some women with cancer-induced infertility achieve pregnancy, the development of effective methods to protect ovarian function during chemotherapy would be a significant advantage.

OBJECTIVE AND RATIONALE

This paper critically discusses the different damaging effects of the most common chemotherapeutic compounds on the ovary, in particular, the ovarian follicles and the molecular pathways that lead to that damage. The mechanisms through which fertility-protective agents might prevent chemotherapy drug-induced follicle loss are then reviewed.

SEARCH METHODS

Articles published in English were searched on PubMed up to March 2019 using the following terms: ovary, fertility preservation, chemotherapy, follicle death, adjuvant therapy, cyclophosphamide, cisplatin, doxorubicin. Inclusion and exclusion criteria were applied to the analysis of the protective agents.

OUTCOMES

Recent studies reveal how chemotherapeutic drugs can affect the different cellular components of the ovary, causing rapid depletion of the ovarian follicular reserve. The three most commonly used drugs, cyclophosphamide, cisplatin and doxorubicin, cause premature ovarian insufficiency by inducing death and/or accelerated activation of primordial follicles and increased atresia of growing follicles. They also cause an increase in damage to blood vessels and the stromal compartment and increment inflammation. In the past 20 years, many compounds have been investigated as potential protective agents to counteract these adverse effects. The interactions of recently described fertility-protective agents with these damage pathways are discussed.

WIDER IMPLICATIONS

Understanding the mechanisms underlying the action of chemotherapy compounds on the various components of the ovary is essential for the development of efficient and targeted pharmacological therapies that could protect and prolong female fertility. While there are increasing preclinical investigations of potential fertility preserving adjuvants, there remains a lack of approaches that are being developed and tested clinically.

A204 ANALYSIS AND CHARACTERIZATION OF THE EXCRETED AND SECRETED PRODUCTS OF PARASITIC HELMINTHS AS IMMUNOMODULATORS OF INFLAMMATORY BOWEL DISEASE

Background

Parasitic helminths are known for their exceptional ability to modulate the host immune response in order to favour their survival. The excretory/secretory products (ESP), from Trichuris and Ascaris species are of keen interest for inflammatory bowel disease (IBD). Crohn’s disease and ulcerative colitis patients have benefitted from the administration of ova of T. suis in clinical trials, whereby symptoms were remediated through the ingestion of parasite ova, which subsequently hatch in the intestine. Our previous work has demonstrated the ability of T. suis ESP to downregulate secretion of inflammatory cytokines (TNF-α, IL-12) and increase the secretion of anti-inflammatory cytokines (IL-10) in murine bone marrow-derived macrophages.

Aims

This research aims to unveil the mechanisms of immune modulation by parasitic helminths in the context of IBD. We aim to characterize the cellular response in vitro, as well as the systemic response in vivo, in order to better characterize the scope of immune modulation that occurs with treatment.

Methods

Human peripheral blood mononuclear cell (PBMC) monocytes were purified and treated with helminth-derived products. The products were removed, and fresh media was added containing lipopolysaccharide (LPS) to stimulate cells. Supernatants were collected for cytokine analysis and cells were lysed and frozen.

Mice were given 3% DSS or regular water for five days, and subsequently administered treatment with helminth-derived products, or a PBS control, once daily by intraperitoneal injection for 3–4 days. Weights were measured daily. On day 9 mice were sacrificed, colons lengths were measured, and spleens were collected for further analysis.

Results

We found that human PBMC monocytes treated with the ESP from T. suis and A. suum had decreased secretion of inflammatory cytokines (TNFα) and increased secretion of anti-inflammatory cytokines (IL-10).

Additionally, we found that heminth products from A. suum had the ability to reverse the symptoms of weight loss and colon shrinking in DSS-mice compared to the control. Specifically, mice with DSS-induced colitis treated with metabolites increased their weight more than the PBS control (P &lt; 0.0001) and had a longer colon compared to the PBS control (P &lt; 0.001).

Conclusions

Taken together, these data generate an interest for intestinal helminth products as immunomodulators regarding treatment for patients suffering from inflammatory bowel disease (IBD).

Funding Agencies

NSERC and FRQNT

A205 NON-POLAR HELMINTH-DERIVED METABOLITES MODULATES INNATE IMMUNE CELL RESPONSE AND PROTECTS MICE FROM EXPERIMENTAL COLITIS

Background

The hygiene hypothesis postulates that the lack of exposure to helminth parasites would contribute to the development of the auto-inflammatory disease. There has been a significant increase in patients with inflammatory bowel disease (IBD) in North America. The previous study showed that infection with gastrointestinal helminth parasitedownregulated inflammatory pathways in several gut inflammation models. Given the known risks of live helminth infection, the therapy should direct towards helminth-derived properties.

Aims

To determine if helminth-derived metabolites treated mice are protected from DSS-induced colitis.

Methods

Preliminary, our screening reveled that non-polar fractions of 4 distinct helminth modulate LPS-induced inflammatory cytokines in vitro. 3% DSS or water was given to C57BL/6 mice for 5 days, followed by 4 days of a recovery period. The mice were treated intraperitoneal injection with non-polar helminth-derived metabolites (NPHM) on days 5, 6, and 7. Inflammation was assessed by disease activity,histopathology and cytokine mRNA expression in colons. The effect of NPHM on neutrophil chemotaxis was assess inin vitroand in vivo.

Results

The disease activity and histopathology score were significantly lower in DSS treated mice received NPHM. Also, NPHM treatment resulted in a decrease of an inflammatory cytokine such as TNF-α mRNA expression in the colon of mice with DSS-induced colitis. Mechanistically, NPHM reduced neutrophil chemotaxis.

Conclusions

NPHM treatment protects against DSS-induced colitis and modulate neutrophil response, which supports helminth therapy for IBD.

Funding Agencies

Supported by Hashimoto Municipal Hospital scholarship to TA and an NSERC Discovery grant to Fernando Lopes.

Genome-enable prediction for health traits using high-density SNP panel in US Holstein cattle

The objective of this study was to compare accuracies of different Bayesian regression models in predicting molecular breeding values for health traits in Holstein cattle. The dataset was composed of 2505 records reporting the occurrence of retained fetal membranes (RFM), metritis (MET), mastitis (MAST), displaced abomasum (DA), lameness (LS), clinical endometritis (CE), respiratory disease (RD), dystocia (DYST) and subclinical ketosis (SCK) in Holstein cows, collected between 2012 and 2014 in 16 dairies located across the US. Cows were genotyped with the Illumina BovineHD (HD, 777K). The quality controls for SNP genotypes were HWE P‐value of at least 1 × 10⁻¹⁰; MAF greater than 0.01 and call rate greater than 0.95. The fimpute program was used for imputation of missing SNP markers. The effect of each SNP was estimated using the Bayesian Ridge Regression (BRR), Bayes A, Bayes B and Bayes Cπ methods. The prediction quality was assessed by the area under the curve, the prediction mean square error and the correlation between genomic breeding value and the observed phenotype, using a leave‐one‐out cross‐validation technique that avoids iterative cross‐validation. The highest accuracies of predictions achieved were: RFM [Bayes B (0.34)], MET [BRR (0.36)], MAST [Bayes B (0.55), DA [Bayes Cπ (0.26)], LS [Bayes A (0.12)], CE [Bayes A (0.32)], RD [Bayes Cπ (0.23)], DYST [Bayes A (0.35)] and SCK [Bayes Cπ (0.38)] models. Except for DA, LS and RD, the predictive abilities were similar between the methods. A strong relationship between the predictive ability and the heritability of the trait was observed, where traits with higher heritability achieved higher accuracy and lower bias when compared with those with low heritability. Overall, it has been shown that a high‐density SNP panel can be used successfully to predict genomic breeding values of health traits in Holstein cattle and that the model of choice will depend mostly on the genetic architecture of the trait.

Association of missense variants in GDF9 with litter size in Entlebucher Mountain dogs

In the past two decades, average litter size (ALS) in Entlebucher Mountain dogs decreased by approximately 0.8 puppies. We conducted a GWAS for ALS using the single-step methodology to take advantage of 1632 pedigree records, 892 phenotypes and 372 genotypes (173 662 markers) for which only 12% of the dogs had both phenotypes and genotypes available. Our analysis revealed associations towards the growth differentiation factor 9 gene (GDF9), which is known to regulate oocyte maturation. The trait heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS. Analysis of WGSs revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (-0.75 ± 0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids.

Refining the phenotype associated with biallelic DNAJC21 mutations

Inherited bone marrow failure syndromes (IBMFS) are caused by mutations in genes involved in genomic stability. Although they may be recognized by the association of typical clinical features, variable penetrance and expressivity are common, and clinical diagnosis is often challenging. DNAJC21, which is involved in ribosome biogenesis, was recently linked to bone marrow failure. However, the specific phenotype and natural history remain to be defined. We correlate molecular data, phenotype, and clinical history of 5 unreported affected children and all individuals reported in the literature. All patients present features consistent with IBMFS: bone marrow failure, growth retardation, failure to thrive, developmental delay, recurrent infections, and skin, teeth or hair abnormalities. Additional features present in some individuals include retinal abnormalities, pancreatic insufficiency, liver cirrhosis, skeletal abnormalities, congenital hip dysplasia, joint hypermobility, and cryptorchidism. We suggest that DNAJC21-related diseases constitute a distinct IBMFS, with features overlapping Shwachman-Diamond syndrome and Dyskeratosis congenita, and additional characteristics that are specific to DNAJC21 mutations. The full phenotypic spectrum, natural history, and optimal management will require more reports. Considering the aplastic anemia, the possible increased risk for leukemia, and the multisystemic features, we provide a checklist for clinical evaluation at diagnosis and regular follow-up.

Triggering immunological memory against the tapeworm Hymenolepis diminuta to protect against colitis

Infection with parasitic helminths can ameliorate the severity of concomitant inflammatory disease. To use the tapeworm, Hymenolepis diminuta, and to extend this concept by assessing whether triggering a memory response against the worm inhibits dinitrobenzene sulphonic acid (DNBS)-induced colitis in Balb/c mice. Initial studies revealed that oral infection with 1, 3 or 5 H. diminuta cysticercoids 8 days before intrarectal administration of DNBS (3 mg) resulted in less severe inflammation and that infected mice displayed an increased propensity for T helper-2 immunity. A 1 mg dose of a PBS-soluble extract of the worm (HdAg) delivered intraperitoneally concomitant with DNBS was anticolitic as determined by macroscopic and histological disease scores 72 hour post-DNBS. Mice infected 28 days previously had a memory response as determined by HdAg-evoked increases in interleukin (IL)-4 and IL-10 from in vitro stimulated splenocytes and serum anti-H. diminuta IgG. Moreover, mice infected with 5 H. diminuta 28 days previously were protected from DNBS-induced colitis by secondary infection or 100 μg HdAg (ip.) at the time of DNBS treatment. An additional approach to managing inflammatory disease could be infection with H. diminuta followed by eliciting antiworm recall responses.

Temporal variability of radon in a remediated tailing of uranium ore processing--the case of Urgeiriça (central Portugal)

Radon monitoring at different levels of the cover of the Urgeiriça tailings shows that the sealing is effective and performing as desired in terms of containing the strongly radioactive waste resulting from uranium ore processing. However, the analysis of the time series of radon concentration shows a very complex temporal structure, particularly at depth, including very large and fast variations from a few tens of kBq m(-3) to more than a million kBq m(-3) in less than one day. The diurnal variability is strongly asymmetric, peaking at 18 h/19 h and decreasing very fast around 21 h/22 h. The analysis is performed for summer and for a period with no rain in order to avoid the potential influence of precipitation and related environmental conditions on the radon variability. Analysis of ancillary measurements of temperature, relative humidity, wind speed and wind direction, as well as atmospheric pressure reanalysis data shows that the daily averaged radon concentration in the taillings material is anti-correlated with the atmospheric pressure and that the diurnal amplitude is associated with the magnitude of atmospheric pressure daily oscillations.

Validation of an approach to predict total-tract fiber digestibility using a standardized in vitro technique for different diets fed to high-producing dairy cows

The experimental objective was to validate an in vitro model to predict total-tract neutral detergent fiber (NDF) digestibility in dairy cattle. Twenty-one diets from 7 studies conducted at University of Wisconsin-Madison were analyzed for in vitro fiber digestibility. Forages varied among diets (corn, alfalfa, tall and meadow fescue, and wheat straw silages) and nutrient composition (ranges: NDF = 22.5 to 33.8%; crude protein = 15.8 to 18.9%; nonfiber carbohydrates = 38.0 to 51.0%). Total-tract NDF digestibility (TTNDFD) observed in in vivo trials was determined using different markers as described in the individual studies. The in vitro TTNDFD model predicted total-tract fiber digestibility from the proportion of total NDF potentially digestible (pdNDF), rate of pdNDF degradation, and rate of passage of pdNDF. The model predicted TTNDFD similar to in vivo measurements. The relationship between TTNDFD measured in vivo and TTNDFD predicted by the in vitro assay was significant (R(2) = 0.68). The relationship between in vitro 30-h NDF digestibility values and in vivo total-tract NDF digestibility values was not significant, whereas in vitro 48-h NDF digestibility values were correlated (R(2) = 0.30) with in vivo TTNDFD measurements. Indigestible NDF (iNDF) showed a negative relationship (R(2) = 0.40) with TTNDFD in vivo. Each 1-percentage-unit increase of iNDF resulted in a decrease of 0.96 percentage units of total-tract NDF digestibility; however, iNDF by itself was not a good predictor of TTNDFD because of the difference among the means. This study showed that an in vitro TTNDFD model that uses iNDF, pdNDF, and rates of pdNDF digestion and passage can predict (R(2) = 0.68) total-tract NDF digestibility. Most importantly, we demonstrated the ability to predict total-tract fiber digestibility from a model based on in vitro NDF degradation, which could improve our ability to optimize forage utilization and milk production.