A novel deleterious oxytocin variant is associated with the lower twinning ratio in Awassi ewes

This study aimed to assess the possible association of oxytocin (OXT) gene with reproductive traits in two groups of Awassi ewes that differ in their reproductive potentials. Sheep were genotyped using PCR-single-stranded conformation polymorphism approach. Three genotypes were detected in exon 2, CC, CA, and AA, and a novel SNP was identified with a missense effect on oxytocin (c.188C > A → p.Arg55Leu). A significant (p < 0.01) association of p.Arg55Leu with the twinning rate was found as ewes with AA and CA genotypes exhibited, respectively a lower twinning ratio than those with the wild-type CC genotype. The deleterious impact of p.Arg55Leu was demonstrated by all in silico tools that were utilized to assess the effect of this variant on the structure, function, and stability of oxytocin. Molecular docking showed that p.Arg55Leu caused a dramatic alteration in the binding of oxytocin with its receptor and reduced the number of interacted amino acids between them. Our study suggests that ewes with AA and CA genotypes showed a lower reproductive performance due to the presence of p.Arg55Leu, which caused damaging impacts on oxytocin and is binding with the OXT receptor. The utilization of the p.Arg55Leu could be useful for improving Awassi reproductive potential.

The relationship between OXT gene polymorphisms and reproductive hormones in pregnant and lactating Awassi Ewes

BACKGROUND

Numerous genetic loci interact intricately to control reproduction in mammals. The oxytocin gene (OXT) is a promising candidate for reproductive traits in mammals. Previously, sheep and goats have been studied for the presence of the OXT polymorphism. As of yet, no polymorphisms have been identified in the OXT gene of Awassi sheep. Thus, this study was conducted to determine the effects of OXT polymorphism and litter size on reproductive hormones in pregnant and lactating Awassi ewes.

METHODS AND RESULTS

This study evaluated 232 ewes aged 3 and 4 years (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones using ELISA kits manufactured by ELK Biotechnology. DNA was extracted from sheep blood for genotyping and sequencing to identify variations in OXT gene (exon 2, 266 bp). Genotyping analysis revealed three genotypes within 266 bp: CC, CA, and AA. Sequence analysis revealed a novel mutation in exon 2: 188 C > A. Statistical analysis showed significant associations between the 188 C > A SNP and phenotypic traits. Twin-pregnant ewes carrying CC genotypes had higher estrogen, progesterone, and follicle-stimulating hormone/luteinizing hormone levels (65.86 ± 3.87) (pg/mL), (6.51 ± 0.39) (ng/mL), and (20.22 ± 1.27) (ng/mL)/( 23.37 ± 2.14) (ng/mL) respectively, compared to CA and AA genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes.

CONCLUSIONS

This study found that the 188 C > A SNP negatively affected reproductive hormone levels in Awassi sheep. These findings provide breeders with a new insight into the sheep OXT gene, useful for future breeding.

Protective effect of resveratrol on the integrity of alveolar and intestinal epithelial barrier in SEB-induced acute lung injury

Acute lung injury (ALI) is a state of inflammation that breaks down the lung endothelial and epithelial cell barriers. In the current study, we investigated the role of resveratrol (RES) in regulating the expression and functions of tight junction proteins (TJP) in epithelial cell responses following exposure to this superantigen. To this end, C3H mice were given resveratrol orally twice prior to intranasal challenge with lethal SEB doses. 16S rRNA results showed that there were microbes transported in the blood in addition to the lung and colonic tissues. For this purpose, we used a reporter E. coli-GFP labeled bacterium to monitor and examine the viability of this bacterium in case of leak from lung into blood and other body compartments during the peak of ALI. The flow cytometry results showed significant reduction in copy numbers of this reporter in the blood in RES-treated mice in comparison to vehicle-treated mice. However, bacteriological examination for viability by culture of the blood showed all were negative for all experimental groups. Mouse transcriptome array showed increase in TJP gene expression in colonic and alveolar epithelial cells of RES-treated mice. Some of these genes were validated with qPCR. We found that there was an increase in the expression of some TJP genes following RES treatment. Commensals and probiotics are also known to decrease intestinal barrier dysfunction caused by inflammatory cytokines. Therefore, mass spectrometry (MS) analysis showed increase in the metabolome in colons of RES-treated group that help in strengthening of intestinal barrier. In conclusion, RES treatment increased directly or indirectly the rigidity of cell boundaries resulting in amelioration of ALI-dependent complications.

Gut dysbiosis and immunological profile in endometriosis

Ectopic growth of normal cells or debris originating from endometrium, the inner layer of female reproductive tube leads to endometriosis. The main symptoms are dyspareunia, dysmenorrhea, and sometimes chronic pelvic pain. Unfortunately, it has no cure or treatment, only symptoms relief medication or surgical removal. Endometriosis causes estrogen imbalance leading to intestinal bacterial estrobolome dysregulation and subsequent change in immune response. Our study aims to investigate the linkage between gut dysbiosis and immunological response in endometriotic mice. Balb/c mice were ovariectomized (OVX) 7 days before intraperitoneal transplantation of 2mm2 endometrial tissue from OVX donors to OVX- or intact ovary recipients. Colonic content was collected 2 weeks post transplantation for 16s rRNA pyrosequencing. Peritoneal exudate was collected and stained to determine the phenotype of infiltrating cells by flow cytometry. Results revealed a significant increase in the number of exudate cells, natural killer (NK) cells and myeloid derived suppressor cells (MDSCs) in endometriotic mice. Phylogenetic taxonomy showed an increase in the biomass of the bacteria in endometriotic OVX mice in comparison with endometriotic nonovariectomized mice. However, the abundance of Phylum Tenericutes, Order Clostridiales, Dehalobacterium sp. and Anaeroplasma sp. were decreased. Collectively, endometriosis changed estrogen metabolism and gut microbiota which resulted in the immune modulation. (Supported by NIH P01AT003961, R01AT006888, R01MH094755, P20GM103641, R01AI129788 and R01AI123947 to PN and MN, and MoHESR to AKM).

Marijuana THC treatment led to decreased metabolic functions of Staphylococcal enterotoxin B-activated lymphocytes

Studies from our laboratory have shown that Δ9-Tetrahydrocannabinol (THC), an ingredient found in marijuana plant Cannabis sativa, can attenuate acute lung injury induced by Staphylococcus enterotoxin B (SEB). In the current study, we investigated the role of THC on the metabolism of SEB-activated lymphocytes. To this end, we determined metabolic potential of SEB-activated lymphocytes treated with vehicle or THC by performing the Cell Mito Stress Test. The oxygen consumption rate (OCR) in THC-treated cells was decreased when compared to vehicle-treated group whereas the extracellular acidification rate (ECAR) was similar in both the groups. Specifically, electron transport chain inhibitors namely, oligomycin, FCCP and rotenone+antimycinA were added to measure ATP-linked respiration, maximal respiration and non-mitochondrial respiration, respectively. THC treatment led to a significant decrease in the basal respiration, ATP production, proton (H+) leak, maximal respiration, spare respiratory capacity and nonmitochondrial respiration. We also performed the Mito Fuel Flex assay to measure the dependency, capacity and flexibility of cells to oxidize glucose, glutamine and fatty acids. Treatment with inhibitors, BPTES and etomoxir showed a decline in the OCR in SEB+vehicle treated cells demonstrating that glutamine and/or fatty acids serve as major source of fuel in these cells when compared to SEB+THC treated group. However, when UK5099 was added, THC- and vehicle-treated cells showed a reduced response thereby indicating that glucose dependency was similar in both the groups. Together, THC modulates metabolic functions of activated lymphocytes which may affect their signaling, differentiation and toxicity.

Resveratrol treatment alters lung microbiome in the murine ovalbumin-induced asthma model by increasing mucus-degrading Akkermansia muciniphila

Asthma is a chronic inflammatory disease that involves the narrowing of the lung airways and excessive mucus production. Resveratrol (RES), a polyphenolic stilbene, is known to control asthmatic attacks via different molecular mechanisms. However, no studies have examined the effect of resveratrol on the microbiome in the ovalbumin (OVA)-induced asthma mouse model. In this study, we induced asthma in BALB/c mice by injecting OVA followed by 7 days treatment with RES. Plethysmography showed that the expiratory resistance in the lung tissue was significantly reduced in the RES treated group, while mean volume, peak expiratory flow, and frequency of respiration was increased. Histopathological examination of the lungs of the RES-treated group showed significant reduction in inflammatory cell infiltration and led to restoration of normal lung tissue architecture. In addition, there were significant increases in the expression of the genes encoding tight-junction molecules (claudin-1 and cadherin-18) in the RES-treated group. We performed 16S rRNA microbial analysis of cecal flushes and pulmonary tissues, which showed that RES treatment alters the gut microbiome by significantly increasing the level of Bacteroides acidifaciens spp. compared to disease controls. In addition, there was a significant increase in Akkermansia muciniphila (AM) species within the lungs after RES treatment. AM is a gram-negative, non-spore-forming bacterium known to induce mucus degradation. Since asthma is characterized by an increase in mucus in the lungs, we concluded that RES improves asthma in OVA-induced mouse model by significantly increasing AM and preventing mucus build-up in the lungs.

Combination of cannabinoids, Δ9- tetrahydrocannabinol (THC) and cannabidiol (CBD), mitigate experimental autoimmune encephalomyelitis (EAE) by altering the gut microbiome

Multiple Sclerosis (MS), is a common autoimmune disease that affects the central nervous system. Currently, there is no cure for MS, and most treatments involve the use of immunosuppressive drugs that can have adverse effects or increased toxicity. Cannabis, commonly known as marijuana, is a product of the Cannabis sativa, and for several centuries has been used as an alternative medicine in many cultures. Cannabis sativa produces over 421 chemical compounds, including about 80 terpenophenols named phytocannabinoids, and include both psychotropic THC and non-psychoactive CBD. In the currently study, we show that a combination therapy using THC and CBD results in amelioration of EAE, an animal model of MS, by reducing hind limb paralysis, decreasing immune cellular infiltration into the brain, and mitigating the presence of inflammatory biomarkers, including gram negative bacteria-associated lipopolysaccharide (LPS). Interestingly, the gut microbiome plays an important role in immune function and studies have shown that it is altered significantly in MS patients. Inasmuch, we performed 16S rRNA sequencing on experimental groups to investigate the gut microbiome composition after using a combination of THC and CBD compared to disease controls. Interestingly, we found that EAE mice showed increase in the mucin degrading bacterial species, Akkermansia municiphila, which was significantly reduced in disease mice treated with THC+CBD. Collectively, our data suggests that THC+CBD can ameliorate EAE by preventing accumulation of mucin-degrading bacteria that would lead to increased gut microbial dysbiosis.

Attenuation of Staphylococcal enterotoxin-B (SEB)-induced lung injury (ALI) by resveratrol results from miR-193a down-regulation and alterations in metabolic profile

Resveratrol, (RES), a phytoalexin, is well-known for its anti-inflammatory and anti-oxidant properties. SEB, a superantigen, is known to trigger ALI and cause mortality. In the current study, we tested the effect of RES in a dual-dose model of SEB exposure that triggers ALI and causes 100% mortality in C3H/HeJ-mice. The data revealed RES attenuated SEB-induced ALI and prevented mortality. Forty eight hours post-SEB exposure, lung-infiltrating mononuclear cells were tested for microRNA expression profile to determine the epigenetic regulation by resveratrol. SEB-activated splenocytes were pre-treated with 50 μM of RES or vehicle for metabolic profile analysis by measuring oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). We also noted significant decline in miR-193a in the lungs of RES-treated SEB group, which targeted and caused an increase in TGFβ2 and TGFβR3, potent inhibitors of T-cell proliferation, by using RT-PCR and validation by transfection studies. RES-induced downregulation of miR-193a also influenced the activity of mechanistic target of rapamycin (mTOR) as well as pyruvate kinase muscle isozyme2 (PKM2) genes, and caused RES-treated SEB-activated T cells to be quiescent metabolically in comparison to the energetic vehicle-treated SEB-activated T cells. Together, RES caused inhibition in the proliferation of SEB-activated T-cells by alterations in miR expression and metabolic profiles. (Supported by NIH grants P01AT003961, R01AT006888, R01ES019313, R01MH094755, P20GM103641 and R01AI129788).

Resveratrol improves a murine model of asthma through alterations in the gut microbiome

Asthma is a condition characterized by bronchial spasms, inflammation, and mucous hypersecretion which leads to difficulties in respiration. Asthmatic patients are usually presented with recurrent attacks of coughing, wheezing, and shortness of breath which could be life-threatening. More than three million cases of asthma in the United States are diagnosed annually. Resveratrol, a polyphenolic stilbene, is known to be useful in controlling asthmatic attacks via different molecular mechanisms within the lung epithelium and infiltrating immune cells. However, few studies mentioned the effect of resveratrol on the microbiome in ovalbumin-induced asthma mouse model. In this study, we induce asthma in BALB/c mice by injecting ovalbumin (OVA) with aluminum hydroxide intraperitoneally followed by 7 days treatment with resveratrol (100mg/kg) by oral gavage. Intranasal ovalbumin was given on day 8 to induce asthma followed by 7 more days of treatment with resveratrol. We performed 16S rRNA microbial analysis on cecal flushes between disease and treatment groups, noting changes in microbial diversity among disease and treated groups. Specifically, we identified alterations in gut microbial composition, which included significantly higher levels of Prevotella in the disease groups, which was reduced upon treatment with resveratrol. In addition, Bacteroides acidifaciens species were significantly lower in the asthma-induced mice and significantly increased in resveratrol treated.

Supported in part by NIH grants P01AT003961, R01AT006888, R01ES019313, R01MH094755, P20GM103641, MoHESR and R01AI129788

Protective effects of Δ9-Tetrahydrocannabinol (THC) results from alteration in lung dysbiosis mediated by SEB-induced acute lung injury

Inhalation of Staphylococcal Enterotoxin B (SEB) is known to induce acute lung injury (ALI) and studies from our laboratory have shown that THC, a psychoactive ingredient found in Cannabis sativa, can attenuate the ALI. In the current study, we investigated the role played by lung microbiota in ALI with or without THC treatment. A dual-dose of SEB was given to C3H/HeJ mice, which were then treated either with vehicle or THC. SEB-administration caused ALI and 100% mortality while all THC-treated mice survived and suppressed the inflammation in the lungs. Furthermore, lung microbiota was collected and 16S rRNA sequencing was performed. The data were analyzed to determine the alpha and beta diversity. The major phylum was Proteobacteria, class Alphaproteobacteria and orders were Caulobacterles and Rhodobacteralesin in the lungs of vehicle-treated SEB group. Moreover, THC treatment led to elevated Firmicutes phylum due to significant increase in the beneficial genus, Lactobacillus. Lipopolysaccharide (LPS), gram negative bacterial endotoxin was found at significantly higher concentration in the BALF of vehicle-treated group in comparison with THC-treated mice. Beneficial metabolome levels were significantly higher in the colonic flush of THC-treated mice when compared to vehicle-treated SEB group, specifically butyric, propionic and acetic acids. Together, our data suggest that THC attenuates SEB-induced mortality and ALI by altering the microbiota in the lungs (Supported by NIH grants P01AT003961, R01AT006888, R01ES019313, R01MH094755, P20GM103641, R01AI129788 to PN and MN and MoHESR fellowship for AKM).