Publications by authors named "Nancy H Ing"

Males of some species, from horses to humans, require medical help for subfertility problems. There is an urgent need for novel molecular assays that reflect spermatozoal function. In the last 25 years, studies examined RNAs in spermatozoa as a window into gene expression during their development and, more recently, for their functions in early embryo development.

View Article and Find Full Text PDF

The nutritional health of dogs and cats is important to pet owners around the world. Nutrition is inextricably linked to the health of the gastrointestinal system and vice versa. Gastrointestinal signs, such as vomiting, diarrhea, anorexia, or weight loss, are one of the most common reasons that dog and cat owners make non-routine appointments with veterinarians.

View Article and Find Full Text PDF

The glutathione transferase A3-3 (GST A3-3) homodimeric enzyme is the most efficient enzyme that catalyzes isomerization of the precursors of testosterone, estradiol, and progesterone in the gonads of humans and horses. However, the presence of GST A3-3 orthologs with equally high ketosteroid isomerase activity has not been verified in other mammalian species, even though pig and cattle homologs have been cloned and studied. Identifying genes is a challenge because of multiple gene duplications (e.

View Article and Find Full Text PDF

In addition to their well-established role in detoxication, glutathione transferases (GSTs) have other biological functions. We are focusing on the ketosteroid isomerase activity, which appears to contribute to steroid hormone biosynthesis in mammalian tissues. A highly efficient GST A3-3 is present in some, but not all, mammals.

View Article and Find Full Text PDF

Honey bee (Apis mellifera) queens have a remarkable organ, the spermatheca, which successfully stores sperm for years after a virgin queen mates. This study uniquely characterized and quantified the transcriptomes of the spermathecae from mated and virgin honey bee queens via RNA sequencing to identify differences in mRNA levels based on a queen's mating status. The transcriptome of drone semen was analyzed for comparison.

View Article and Find Full Text PDF

Background: It is not unusual for stallions to have fertility problems. For many, artificial insemination with more dense spermatozoa (isolated by density gradient centrifugation) results in greater pregnancy rates compared with the rates when using unfractionated spermatozoa. RNAs in spermatozoa delivered to the oocyte at conception are required for embryo development.

View Article and Find Full Text PDF

Glucocorticoids impair testosterone synthesis by an unknown mechanism. Stallions treated with the synthetic glucocorticoid dexamethasone had testes collected at 6 or 12 hours postinjection. The testicular expression of selected genes encoding nuclear receptors and steroidogenic enzymes was measured.

View Article and Find Full Text PDF

Glutathione transferases (GSTs) comprise a superfamily of enzymes prominently involved in detoxication by making toxic electrophiles more polar and therefore more easily excretable. However some GSTs have developed alternative functions. Thus, a member of the Alpha class GSTs in pig and human tissues is involved in steroid hormone biosynthesis, catalyzing the obligatory double-bond isomerization of Δ-androstene-3,17-dione to Δ-androstene-3,17-dione and of Δ-pregnene-3,20-dione to Δ-pregnene-3,20-dione on the biosynthetic pathways to testosterone and progesterone.

View Article and Find Full Text PDF

In rodents, livestock and primate species, a single dose of the synthetic glucocorticoid dexamethasone acutely lowers testosterone biosynthesis. To determine the mechanism of decreased testosterone biosynthesis, stallions were treated with 0.1mg/kg dexamethasone 12h prior to castration.

View Article and Find Full Text PDF

Marinobufagenin (MBG) is a cardiotonic steroid that increases in the circulation in preeclampsia. Preeclampsia and eclampsia are associated with cerebral edema. Therefore, we examined the effects of MBG on human brain microvascular endothelial cells (HBMEC) in vitro.

View Article and Find Full Text PDF

In vitro fertilization does not occur readily in the horse. This may be related to failure of equine sperm to initiate hyperactivated motility, as treating with procaine to induce hyperactivation increases fertilization rates. In mice, hyperactivated motility requires a sperm-specific pH-gated calcium channel (CatSper); therefore, we investigated this channel in equine sperm.

View Article and Find Full Text PDF

The A+U-rich binding factor 1 (AUF1 or HNRPD) gene produces predominant RNA binding proteins. The AUF1 transcript is alternatively spliced to produce four protein isoforms that stabilize or destabilize hundreds of mRNAs. Previously, we discovered that estradiol (E2) treatment of ovariectomized sheep increased concentrations of AUF1p45 protein which stabilized estrogen receptor alpha (ER) mRNA in the uterus.

View Article and Find Full Text PDF

CD40 is mainly expressed by professional antigen-presenting cells (APCs). Its ligand, CD40L, is transiently expressed on activated CD4(+) T-cells. CD40-CD40L interactions mediate T-cell help to APCs and provide crucial signals for affinity maturation and B-cell class switching.

View Article and Find Full Text PDF

The process of implantation is mediated by a complex network of signaling and adhesive factors. In the pig, latent and active transforming growth factor beta (TGFB), TGFB receptors (TGFBR), and integrins (ITGs) are present during the peri-implantation period. TGFB signals via TGFBR and activates downstream effector SMAD proteins 2 and 3 (p-SMAD2/3).

View Article and Find Full Text PDF

In vitro culture systems are valuable tools for investigating reproductive mechanisms in the testis. Here, we report the use of the precision-cut in vitro system using equine testicular slices. Testes were collected from immature light breed stallions (n=3) and cut into slices (mean slice weight= 13.

View Article and Find Full Text PDF

In the pig, transforming growth factor beta (TGFB), TGFB receptors (TGFBRs), and integrins are present during the peri-implantation period. Latency-associated peptide (LAP), a part of latent TGFB, can bind to integrin heterodimers via its Arg-Gly-Asp (RGD) sequence; therefore, ligand-receptor interactions between TGFB and TGFBRs, along with LAP and integrin heterodimers, may be functional in mediating events supporting conceptus elongation and attachment. With the use of surgically implantable osmotic pumps, we were able to maintain pregnancy with the aim of mechanistically altering in vivo receptor-ligand interactions involving TGFB with TGFBRs and LAP with integrins during porcine pregnancy.

View Article and Find Full Text PDF

Estradiol up-regulates expression of the estrogen receptor alpha gene in the uterus by stabilizing estrogen receptor alpha mRNA. Previously, we defined two discrete minimal estradiol-modulated stability sequences (MEMSS) within the extensive 3'-untranslated region of estrogen receptor alpha mRNA with an in vitro stability assay using cytosolic extracts from sheep uterus. We report here that excess MEMSS RNA inhibited the enhanced stability of estrogen receptor alpha mRNA in extracts from estradiol-treated ewes compared with those from control ewes.

View Article and Find Full Text PDF

Steroid hormones regulate endometrial gene expression to meet the needs of developing embryos. Our hypothesis is that steroid hormones transiently induce expression of genes in the endometrial epithelium to make the uterine environment different between the earliest days of pregnancy. We identified one such gene product using differential display-polymerase chain reactions.

View Article and Find Full Text PDF

In pigs, expression and amounts of biologically active TGFbetas at the conceptus-maternal interface increase significantly as conceptuses elongate and begin the implantation process. Before their activation, secreted TGFbetas are noncovalently associated with their respective, isoform-specific latency-associated peptides (LAPs), which contain the Arg-Gly-Asp (RGD) amino acid sequence that serves as a ligand for numerous integrins. Objectives of this study were to determine whether TGFbeta1 increases production of fibronectin by porcine trophectoderm, whether porcine trophectoderm adheres specifically to fibronectin and LAP, and whether functional interactions between porcine trophectoderm and the two TGFbeta-associated proteins, fibronectin and LAP, are integrin mediated.

View Article and Find Full Text PDF

Hormones exert powerful effects on reproductive physiology by regulating gene expression. Recent discoveries in hormone action emphasize that regulation of gene expression is not restricted to their alterations of the rate of gene transcription. On the contrary, hormonal effects on the stability of a specific mRNA can profoundly alter its steady-state concentration.

View Article and Find Full Text PDF

A single physiological dose of estradiol up-regulates estrogen receptor-alpha(ER), progesterone receptor (PR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), c-fos, cyclophilin, and actin mRNAs in the endometrium of ovariectomized ewes. Therefore, we hypothesized that these genes would be up-regulated by the preovulatory surge of estrogen which occurs on the evening of Day 15 in the estrous cycle of sheep. ER and PR mRNA concentrations increased between Day 15 and Day 1 in cyclic ewes in most endometrial epithelial cells, while GAPDH mRNA increased in epithelial and stromal cells in the deep endometrium.

View Article and Find Full Text PDF

In the testis of the 1.5-year-old horse, spermatogenesis initiates locally in grossly light, central areas that contrast with grossly dark, peripheral areas that are as yet inactive in spermatogenesis. Gene expression was compared between "light" and "dark" tissues of 1.

View Article and Find Full Text PDF

We examined in vivo effects of selective estrogen receptor modulators (SERMs) 4-OH-tamoxifen (Tam), GW 5638 (GW) and EM-800 (EM) on myometrial gene expression. The uteri of ovariectomized ewes were infused with 10(-7)M of one SERM via indwelling catheters for 24h preceding hysterectomy. Half of the ewes in each SERM group received an intramuscular injection of 50 microg 17beta-estradiol (E2) 18 h prior to hysterectomy.

View Article and Find Full Text PDF

Three selective estrogen receptor modulator (SERM) drugs which included 4-OH-tamoxifen (Tam), EM-800 (EM) and GW 5638 (GW) were investigated to determine their ability to inhibit estradiol-responsive gene expression in sheep endometrium. The uteri of ovariectomized ewes (10 ewes per SERM group) were infused with 10(-7)M SERMs for 24h prior to hysterectomy. Five ewes from each group received 50 microg 17beta-estradiol (E2) and the remaining five ewes received vehicle 18 h prior to hysterectomy.

View Article and Find Full Text PDF

Estrogens upregulate estrogen receptor (ER) and progesterone receptor (PR) gene expression in endometrium immediately before ovulation to prepare it for nurturing embryos. Most in vitro model systems have lost the ability to upregulate expression of the ER gene in response to estradiol (E2) or the ability to express the ER gene at all. Here, we used explant cultures from control and E2-treated ewes and assessed expression of four genes (ER, PR, glyceraldehyde 3-phosphate dehydrogenase [GAPDH], and cyclophilin [CYC] genes) that are upregulated by E2 in vivo on Northern blots.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionb7kj4poaq7fucb3jirtvh6cetmde8sc8): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once