Fetal and Maternal Transforming Growth Factor-β1 May Combine to Maintain Pregnancy in Mice1

Genetic parameters and genome-wide association studies for mozzarella and milk production traits, lactation length, and lactation persistency in Murrah buffaloes

Genetic and genomic analyses of longitudinal traits related to milk production efficiency are paramount for optimizing water buffaloes breeding schemes. Therefore, this study aimed to (1) compare single-trait random regression models under a single-step genomic BLUP setting based on alternative covariance functions (i.e., Wood, Wilmink, and Ali and Schaeffer) to describe milk (MY), fat (FY), protein (PY), and mozzarella (MZY) yields, fat-to-protein ratio (FPR), somatic cell score (SCS), lactation length (LL), and lactation persistency (LP) in Murrah dairy buffaloes (Bubalus bubalis); (2) combine the best functions for each trait under a multiple-trait framework; (3) estimate time-dependent SNP effects for all the studied longitudinal traits; and (4) identify the most likely candidate genes associated with the traits. A total of 323,140 test-day records from the first lactation of 4,588 Murrah buffaloes were made available for the study. The model included the average curve of the population nested within herd-year-season of calving, systematic effects of number of milkings per day, and age at first calving as linear and quadratic covariates, and additive genetic, permanent environment, and residual as random effects. The Wood model had the best goodness of fit based on the deviance information criterion and posterior model probabilities for all traits. Moderate heritabilities were estimated over time for most traits (0.30 ± 0.02 for MY; 0.26 ± 0.03 for FY; 0.45 ± 0.04 for PY; 0.28 ± 0.05 for MZY; 0.13 ± 0.02 for FPR; and 0.15 ± 0.03 for SCS). The heritability estimates for LP ranged from 0.38 ± 0.02 to 0.65 ± 0.03 depending on the trait definition used. Similarly, heritabilities estimated for LL ranged from 0.10 ± 0.01 to 0.14 ± 0.03. The genetic correlation estimates across days in milk (DIM) for all traits ranged from -0.06 (186-215 DIM for MY-SCS) to 0.78 (66-95 DIM for PY-MZY). The SNP effects calculated for the random regression model coefficients were used to estimate the SNP effects throughout the lactation curve (from 5 to 305 d). Numerous relevant genomic regions and candidate genes were identified for all traits, confirming their polygenic nature. The candidate genes identified contribute to a better understanding of the genetic background of milk-related traits in Murrah buffaloes and reinforce the value of incorporating genomic information in their breeding programs.

Circulating levels of transforming growth factor beta-1, 2 and 3 in HIV associated preeclamptic pregnancies

The active role of transforming growth factor-beta in implantation, embryonic development and decidualization has driven our interest to evaluate circulating TGF-β(1-3) in the synergy of HIV associated pregnancy. Serum TGF-β(1-3) was quantified in normotensive (n = 38) and preeclamptic (n = 38) pregnant women, who were stratified by HIV status, HIV negative (n = 19) and HIV positive (n = 19), using a Bioplex immunoassay.Based on HIV status, we report no significant difference in TGF-β-1 (p = .95) and TGF-β2 (p = .80) however, TGF-β3 was significantly downregulated in HIV positive (p = .03) vs the HIV negative groups. A significant positive correlation (p < .05) was noted between TGF-β3 and gestational age (p = .03) (r = 0.51), birth weight (p = .04) (r = 0.53) and CD4 count (p = .02) (r = 0.53). Bivariate correlation between isoforms based on HIV status showed several significant positive associations. In the synergy of HIV infected PE, we demonstrate an association between TGF-β(1-3) with PE emanating from the hypoxic microenvironment that affects receptor-SMAD activity. Decreased TGF-β3 levels in HIV infected PE, may originate from ARV usage and/or the mutational/physiological dysregulation of SMAD expression. Impact StatementWhat is already known on this subject? TGF-β overexpression can convert its protective functions into pathogenic variants. It has a significant role in the oxidatively stressed and inflammatory condition of tissue fibrosis and hence may also be dysregulated in the microenvironment of PE. In HIV infection, TGF-β promotes viral replication and spreading through the induction of cellular proteins which induce TGF-β production. Also, mononuclear phagocytes infected with HIV also produce increased TGF-β mRNA and proteins.What do the results of the study add? Our results show no association of TGF-β isoforms (1-3) based on pregnancy type (PE vs normotensive pregnant) at term. The lack of association may be linked to TGF-βs dual promoter/suppresser nature or to gestational age.What are the implications of these findings for clinical practice and/or further research? Large-scale comprehensive clinical trials are warranted to elucidate the association and mechanistic role of TGF-β receptor-SMAD signalling, the effect of its inhibitors on cell invasion and angiogenesis as well as to deliver valuable data for the detection of novel therapeutic agents in pregnancies complicated by HIV infection.

Influence of prominent immunomodulatory cytokines TNF-α308 G>A (rs1800629) and TGFβ1 G>C (rs1800471) sequence variations as an important contributing factor in etiopathogenesis of recurrent miscarriages in Kashmiri women (North India)

AIM

We aimed to evaluate the genetic variation of tumor necrosis factor-α (TNF-α) 308 G>A (rs1800629) and transforming growth factor (TGF) β1G>C (rs1800471) to confer risk in patients with recurrent miscarriage in highly consanguineous population of Kashmir (North India).

METHODS

A total of 200 women who experienced two or more recurrent miscarriages (along with 100 spouses, 60 products of conception, and 240 healthy controls) with two or more full-term pregnancies were recruited from the same geographical region and evaluated by polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

TNF-α 308 G>A variant genotype (AA) was significantly associated with recurrent miscarriage cases (2.5% vs. 0.4% controls, respectively; p < 0.05) and its per copy allele A also presented more in cases (32% vs. 24% in controls; p < 0.05) that showed a risk of 1.5-fold for cases (p < 0.05). The difference of variant genotype GA was observed to be significant among recurrent miscarriage cases and product of conception: 60.5% vs. 83%, respectively (p < 0.05) wherein variant TNF-α GA genotype conferred 3-fold risk (p < 0.05). On the other hand, TGF β1 G>C showed no association with recurrent miscarriage cases in our population.

CONCLUSION

The study found both TNF-α 308 G>A variants are significantly associated with an increased susceptibility for recurrent miscarriages to cause pregnancy losses but on the other hand TGF β1 does not seem to impact the outcome of pregnancy in our population.

Cerebrum, liver, and muscle regulatory networks uncover maternal nutrition effects in developmental programming of beef cattle during early pregnancy

The molecular basis underlying fetal programming in response to maternal nutrition remains unclear. Herein, we investigated the regulatory relationships between genes in fetal cerebrum, liver, and muscle tissues to shed light on the putative mechanisms that underlie the effects of early maternal nutrient restriction on bovine developmental programming. To this end, cerebrum, liver, and muscle gene expression were measured with RNA-Seq in 14 fetuses collected on day 50 of gestation from dams fed a diet initiated at breeding to either achieve 60% (RES, n = 7) or 100% (CON, n = 7) of energy requirements. To build a tissue-to-tissue gene network, we prioritized tissue-specific genes, transcription factors, and differentially expressed genes. Furthermore, we built condition-specific networks to identify differentially co-expressed or connected genes. Nutrient restriction led to differential tissue regulation between the treatments. Myogenic factors differentially regulated by ZBTB33 and ZNF131 may negatively affect myogenesis. Additionally, nutrient-sensing pathways, such as mTOR and PI3K/Akt, were affected by gene expression changes in response to nutrient restriction. By unveiling the network properties, we identified major regulators driving gene expression. However, further research is still needed to determine the impact of early maternal nutrition and strategic supplementation on pre- and post-natal performance.

Exogenous transforming growth factor-β1 enhances smooth muscle differentiation in embryonic mouse jejunal explants

An ex vivo experimental strategy that replicates in vivo intestinal development would in theory provide an accessible setting with which to study normal and dysmorphic gut biology. The current authors recently described a system in which mouse embryonic jejunal segments were explanted onto semipermeable platforms and fed with chemically defined serum-free media. Over 3 days in organ culture, explants formed villi and they began to undergo spontaneous peristalsis. As defined in the current study, the wall of the explanted gut failed to form a robust longitudinal smooth muscle (SM) layer as it would do in vivo over the same time period. Given the role of transforming growth factor β1 (TGFβ1) in SM differentiation in other organs, it was hypothesized that exogenous TGFβ1 would enhance SM differentiation in these explants. In vivo, TGFβ receptors I and II were both detected in embryonic longitudinal jejunal SM cells and, in organ culture, exogenous TGFβ1 induced robust differentiation of longitudinal SM. Microarray profiling showed that TGFβ1 increased SM specific transcripts in a dose dependent manner. TGFβ1 proteins were detected in amniotic fluid at a time when the intestine was physiologically herniated. By analogy with the requirement for exogenous TGFβ1 for SM differentiation in organ culture, the TGFβ1 protein that was demonstrated to be present in the amniotic fluid may enhance intestinal development when it is physiologically herniated in early gestation. Future studies of embryonic intestinal cultures should include TGFβ1 in the defined media to produce a more faithful model of in vivo muscle differentiation. Copyright © 2017 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.

Transforming growth factor β signaling in uterine development and function

Transforming growth factor β (TGFβ) superfamily is evolutionarily conserved and plays fundamental roles in cell growth and differentiation. Mounting evidence supports its important role in female reproduction and development. TGFBs1-3 are founding members of this growth factor family, however, the in vivo function of TGFβ signaling in the uterus remains poorly defined. By drawing on mouse and human studies as a main source, this review focuses on the recent progress on understanding TGFβ signaling in the uterus. The review also considers the involvement of dysregulated TGFβ signaling in pathological conditions that cause pregnancy loss and fertility problems in women.

Hormonal Fluctuations during the Estrous Cycle Modulate Heme Oxygenase-1 Expression in the Uterus

Deletion of the heme oxygenase-1 (HO-1) (Hmox1) locus in mice results in intrauterine lethality. The expression of the heme catabolizing enzyme encoded by this gene, namely HO-1, is required to successfully support reproductive events. We have previously observed that HO-1 acts at several key events in reproduction ensuring pregnancy. HO-1 defines ovulation, positively influences implantation and placentation, and ensures fetal growth and survival. Here, we embarked on a study aimed to determine whether hormonal changes during the estrous cycle in the mouse define HO-1 expression that may influence receptivity. We analyzed the serum levels of progesterone and estrogen by ELISA and HO-1 mRNA expression in uterus by real time RT-PCR at the metestrus, proestrus, estrus, and diestrus phases of the estrous cycle. Further, we studied the HO-1 protein expression by western blot upon hormone addition to cultured uterine AN3 cells. We observed that HO-1 variations in uterine tissue correlated to changes in hormonal levels at different phases of the estrus cycle. In vitro, HO-1 protein levels in AN3 cells augmented after the addition of physiological concentrations of progesterone and estradiol, which confirmed our in vivo observations. Our data suggest an important role for hormones in HO-1 regulation in uterus during receptivity, a process known to have a significant impact in receptivity and later on blastocyst implantation.

Control of uterine microenvironment by foxp3(+) cells facilitates embryo implantation

Implantation of the fertilized egg into the maternal uterus depends on the fine balance between inflammatory and anti-inflammatory processes. Whilst regulatory T cells (Tregs) are reportedly involved in protection of allogeneic fetuses against rejection by the maternal immune system, their role for pregnancy to establish, e.g., blastocyst implantation, is not clear. By using 2-photon imaging we show that Foxp3(+) cells accumulated in the mouse uterus during the receptive phase of the estrus cycle. Seminal fluid further fostered Treg expansion. Depletion of Tregs in two Foxp3.DTR-based models prior to pairing drastically impaired implantation and resulted in infiltration of activated T effector cells as well as in uterine inflammation and fibrosis in both allogeneic and syngeneic mating combinations. Genetic deletion of the homing receptor CCR7 interfered with accumulation of Tregs in the uterus and implantation indicating that homing of Tregs to the uterus was mediated by CCR7. Our results demonstrate that Tregs play a critical role in embryo implantation by preventing the development of a hostile uterine microenvironment.

Genetic variation in TGFB1 gene and risk of idiopathic recurrent pregnancy loss

Transforming growth factor β1 plays a significant role in pregnancy outcome. We investigated the association of TGFB1 exon 1 (rs1800471, rs1800470) and promoter region (rs1800469, rs1800468) polymorphisms with recurrent pregnancy loss (RPL) in 675 Tunisian women: 304 women with a history of three consecutive pregnancy losses of unknown etiology with the same partner and 371 age-matched multiparous control women. TGFB1 genotyping was done by TaqMan assays. Higher minor allele frequency for rs1800471 (P< 0.001), but not for rs1800470, rs1800469 or rs1800468 was found in RPL cases compared with controls. A significant difference in the distribution of rs1800471 genotypes was seen between the RPL cases and control women, irrespective of the genetic model used. Increased RPL risk was seen with rs1800471 allele C in the heterozygous state and to a greater degree in the homozygous state, thus establishing a dose-dependent effect. Haploview analysis revealed differential linkage disequilibrium between the TGFB1 single-nucleotide polymorphisms analyzed. TGFB1 haplotype analysis identified eight common haplotypes (rs1800471/rs1800470/rs1800469/rs1800468) with three (GTTG, Pc = 0.02; CCTG, Pc = 0.02 and CTCG, Pc = 0.02) positively associated with RPL and one (GCCG, Pc = 0.009) negatively associated with RPL. This study provides the first evidence that the TGFB1 genotype may influence RPL.

Mice with disrupted TGFbeta signaling have normal cerebella development, but exhibit facial dysmorphogenesis and strain-dependent deficits in their body wall

The transforming growth factor betas (TGFbetas) are context-dependent regulators of neurons in vitro, but their physiological functions in the brain are unclear. Haploinsufficiency of either Tgfbeta1 or Tgfbeta2 leads to age-related deterioration of neurons, but the development of the brain is normal in the full absence of either of these genes. However, some individuals with mis-sense mutations of TGFbeta receptors are mentally retarded, suggesting that the TGFbeta isoforms can compensate for each other during brain development. This possibility was tested by generating mice (NSE x PTR) with neuron-specific expression of a dominant-negative inhibitor of TGFbeta signaling. The NSE x PTR mice with a FVBxC57Bl/6 genetic background were viable and developed normally despite strong neuronal expression of the inhibitor of TGFbeta signaling. Their cerebella were of normal size and contained normal numbers of neurons. When the genetic background of the mice was changed to C57BL/6, the phenotype of the mice became neonatal lethal, with the neonates exhibiting various malformations. The malformations correlated with sites of non-neuronal expression of the transgenes and included facial dysmorphogenesis, incomplete closure of the ventral body wall and absence of intestinal motility. The C57BL/6 Tgfbm1-3 alleles, which modulate the phenotype of Tgfbeta1(-/-) mice, were not major determinants of the NSE x PTR phenotype. The data suggest that the development of the cerebellum is insensitive to the level of TGFbeta signaling, although this may be dependent on the genetic background.

Homeostatic role of transforming growth factor-beta in the oral cavity and esophagus of mice and its expression by mast cells in these tissues

Transforming growth factor-beta (TGF-beta) is a pleiotropic growth factor; its overexpression has been implicated in many diseases, making it a desirable target for therapeutic neutralization. In initial safety studies, mice were chronically treated (three times per week) with high doses (50 mg/kg) of a murine, pan-neutralizing, anti-TGF-beta antibody. Nine weeks after the initiation of treatment, a subset of mice exhibited weight loss that was concurrent with decreased food intake. Histopathology revealed a unique, nonneoplastic cystic epithelial hyperplasia and tongue inflammation, as well as dental dysplasia and epithelial hyperplasia and inflammation of both the gingiva and esophagus. In an effort to determine the cause of this site-specific pathology, we examined TGF-beta expression in these tissues and saliva under normal conditions. By immunostaining, we found higher expression levels of active TGF-beta1 and TGF-beta3 in normal tongue and esophageal submucosa compared with gut mucosal tissues, as well as detectable TGF-beta1 in normal saliva by Western blot analysis. Interestingly, mast cells within the tongue, esophagus, and skin co-localized predominantly with the TGF-beta1 expressed in these tissues. Our findings demonstrate a novel and restricted pathology in oral and esophageal tissues of mice chronically treated with anti-TGF-beta that is associated with basal TGF-beta expression in saliva and by mast cells within these tissues. These studies illustrate a previously unappreciated biological role of TGF-beta in maintaining homeostasis within both oral and esophageal tissues.

Transforming growth factor beta2 haploinsufficient mice develop age-related nigrostriatal dopamine deficits

The transforming growth factor-betas (TGF-betas) regulate the induction of dopaminergic neurons and are elevated in the CSF of Parkinson's patients. We report here that mice with TGF-beta2 haploinsufficiency (TGF-beta2+/-) have subclinical defects in the dopaminergic neurons of their substantia nigra pars compacta. At 6 weeks of age, the TGF-beta2+/- mice had 12% fewer dopaminergic neurons than wild-type littermates. No additional loss of neurons occurred during the next 5 months, although striatal dopamine declined to 70% of normal. The level of 3,4-dihydroxphenylacetic acid was normal in the TGF-beta2+/- mice, indicating that a compensatory mechanism maintains dopamine stimulation of their striatum. The TGF-beta2+/- mice had normal sensitivity to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, despite having reduced levels of monoamine oxidase-B. These results raise the possibility that people with naturally low levels of TGF-beta2 may have less functional reserve in their nigrostriatal pathway, causing them to be at increased risk of developing Parkinson disease.

Null mutation in transforming growth factor beta1 disrupts ovarian function and causes oocyte incompetence and early embryo arrest

TGFbeta1 is implicated in regulation of ovarian function and the events of early pregnancy. We have investigated the effect of null mutation in the Tgfbeta1 gene on reproductive function in female mice. The reproductive capacity of TGFbeta1 null mutant females was severely impaired, leading to almost complete infertility. Onset of sexual maturity was delayed, after which ovarian function was disrupted, with extended ovarian cycles, irregular ovulation, and a 40% reduction in oocytes ovulated. Serum FSH and estrogen content were normal, but TGFbeta1 null mutant mice failed to display the characteristic proestrus surge in circulating LH. Ovarian hyperstimulation with exogenous gonadotropins elicited normal ovulation rates in TGFbeta1 null mutant mice. After mating with wild-type stud males, serum progesterone content was reduced by 75% associated with altered ovarian expression of mRNAs encoding steroidogenic enzymes 3beta-hydroxysteroid dehydrogenase-1 and P450 17 alpha-hydroxylase/C17-20-lyase. Embryos recovered from TGFbeta1 null mutant females were developmentally arrested in the morula stage and rarely progressed to blastocysts. Attempts to rescue embryos by exogenous progesterone administration and in vitro culture were unsuccessful, and in vitro fertilization and culture experiments demonstrated that impaired development is unlikely to result from lack of maternal tract TGFbeta1. We conclude that embryo arrest is due to developmental incompetence in oocytes developed in a TGFbeta1-deficient follicular environment. This study demonstrates that TGFbeta1 is a critical determinant of normal ovarian function, operating through regulation of LH activity and generation of oocytes competent for embryonic development and successful initiation of pregnancy.

Transport of transforming growth factor-β2 across the blood–brain barrier

The blood-brain barrier acts as an interface between the brain and body through a combination of restrictive mechanisms and transport processes. Substances essential for brain function pass through the barrier either by passive diffusion or by active transport. We report here that [125I]-transforming growth factor-beta2 (TGF-beta2) passes through the blood-brain barrier and blood-nerve barriers, after intravenous, intraperitoneal or intramuscular injections. The entry of the [125I]-TGF-beta2 to the brain was rapid, saturable and inhibited by co-injection of unlabelled TGF-beta2. In contrast, co-injection of unlabelled TGF-beta2 increased the retention of [125I]-TGF-beta2 in the blood. The [125I]-TGF-beta2 transported into the brain was localised by autoradiography to the extracellular space, and was intact as judged by SDS-PAGE. The [125I]-TGF-beta2 was widely distributed throughout the brain, with the highest concentrations in the hypothalamus and nerves and the lowest in the cerebral hemispheres. The [125I]-TGF-beta2 had a half-life of 4 h in the brain. These results indicate that therapeutically relevant levels of TGF-beta2 reach the brain after peripheral administration of TGF-beta2.

Human endometrial leukemia inhibitory factor and interleukin-6: control of secretion by transforming growth factor-beta-related members

OBJECTIVE(S)

The implantation process is closely linked to the fundamental question of the tolerance of the maternal immune system. The main objective of this study was to investigate whether different members of the transforming growth factor-beta (TGF-beta) superfamily could intervene in the first steps of embryo implantation by modulating the secretion of proimplantatory leukemia inhibitory factor (LIF) and in the tolerance of the fetal graft by regulating proinflammatory interleukin (IL)-6 secretion by human endometrial epithelium (EEC) in vitro.

METHODS

EEC were isolated from biopsies collected from 16 informed and consenting fertile women and were cultured for 72 h. Cytokine measurements (LIF and IL-6) were realized by ELISA.

RESULTS

TGF-beta(1) (from 10(-12) to 10(-8)M), -beta(2), -beta(3) and activin A (10(-10) and 10(-8)M) increased LIF secretion by EEC cultures. Inhibin B (10(-10) and 10(-8)M) did not stimulate LIF production by human EEC. Contrastingly, TGF-beta(1) (from 10(-12) to 10(-8)M), -beta(2), -beta(3) and activin A (10(-10) and 10(-8)M) reduced IL-6 release by the same cells. Activin A at 10(-8) M also significantly reduced the stimulating effect of IL-1beta (10(-9)M) which is known to stimulate LIF production by EEC. Only the highest concentration of inhibin B (10(-8)M) reduced IL-6 secretion by EEC, but did not modulate IL-1beta-induced stimulation of IL-6 secretion.

CONCLUSION(S)

Besides their role in the control of the process of implantation and in the induction of embryonic mesoderm, different members of the TGF-beta superfamily may also contribute in the reproductive process by enhancing endometrial proimplantatory LIF secretion and reducing proinflammatory IL-6 release by EEC.