Senolytic treatment fails to improve ovarian reserve or fertility in female mice

Senescent cell number increases with age in different tissues, leading to greater senescent cell load, proinflammatory stress, and tissue dysfunction. In the current study, we tested the efficacy of senolytic drugs to reduce ovarian senescence and improve fertility in reproductive age female mice. In the first experiment, 1-month-old C57BL/6 female mice were treated every other week with D + Q (n = 24) or placebo (n = 24). At 3 and 6 months of age, female mice were mated with untreated males to evaluate pregnancy rate and litter size. In the second experiment, 6-month-old C57BL/6 female mice were treated monthly with D + Q (n = 30), fisetin (n = 30), or placebo (n = 30). Females were treated once a month until 11 months of age, then they were mated with untreated males for 30 days to evaluate pregnancy rate and litter size. In the first experiment, D + Q treatment did not affect pregnancy rate (P = 0.68), litter size (P = 0.58), or ovarian reserve (P > 0.05). Lipofuscin staining was lower in females treated with D + Q (P = 0.04), but expression of senescence genes in ovaries was similar. In the second experiment, D + Q or fisetin treatment also did not affect pregnancy rate (P = 0.37), litter size (P = 0.20), or ovarian reserve (P > 0.05). Lipofuscin staining (P = 0.008) and macrophage infiltration (P = 0.002) was lower in fisetin treated females. Overall, treatment with D + Q or fisetin did not affect ovarian reserve or fertility but did decrease some senescence markers in the ovary.

Effect of calorie restriction on redox status during chemically induced estropause in female mice

In females, there is a continuous decline of the ovarian reserve with age, which results in menopause in women or estropause in mice. Loss of ovarian function results in metabolic alterations in mice and women. Based on this, we aimed to evaluate the effect of caloric restriction (CR) on redox status and metabolic changes in chemically induced estropause in mice. For this, mice were divided into four groups (n = 10): cyclic ad libitum (AL), cyclic 30% CR, AL estropause, and estropause 30% CR. Estropause was induced using 4-vinylcyclohexene diepoxide (VCD) for 20 consecutive days in 2-month-old females. The CR protocol started at 5 months of age and the treatments lasted for 4 months. The CR females gained less body weight than AL females (p < 0.001) and had lower glycemic curves in response to glucose tolerance test (GTT). The AL estropause females had the highest body weight and body fat, despite having lower food intake. However, the estropause females on 30% CR lost the most body weight and had the lowest amount of body fat compared to all groups. The effect of 30% CR on redox status in fat and liver tissue was similar for cyclic and estropause females. Interestingly, estropause decreased ROS in adipose tissue, while increasing it in the liver. No significant effects of CR on redox status were observed. Chemically induced estropause did not influence the response to 30% CR on glucose tolerance and redox status; however, weight loss was exarcebated compared to cyclic females.

Dynamics of serum exosome microRNA profile altered by chemically induced estropause and rescued by estrogen therapy in female mice

The decline in the ovarian reserve leads to menopause and reduced serum estrogens. MicroRNAs are small non-coding RNAs, which can regulate gene expression and be secreted by cells and trafficked in serum via exosomes. Serum miRNAs regulate tissue function and disease development. Therefore, the aim of this study was to identify miRNA profiles in serum exosomes of mice induced to estropause and treated with 17β-estradiol (E2). Female mice were divided into three groups including control (CTL), injected with 4-Vinylcyclohexene diepoxide (VCD), and injected with VCD plus E2 (VCD + E2). Estropause was confirmed by acyclicity and a significant reduction in the number of ovarian follicles (p < 0.05). Body mass gain during estropause was higher in VCD and VCD + E2 compared to CTL females (p = 0.02). Sequencing of miRNAs was performed from exosomes extracted from serum, and 402 miRNAs were detected. Eight miRNAs were differentially regulated between CTL and VCD groups, seven miRNAs regulated between CTL and VCD + E2 groups, and ten miRNAs regulated between VCD and VCD + E2 groups. Only miR-200a-3p and miR-200b-3p were up-regulated in both serum exosomes and ovarian tissue in both VCD groups, suggesting that these exosomal miRNAs could be associated with ovarian activity. In the hepatic tissue, only miR-370-3p (p = 0.02) was up-regulated in the VCD + E2 group, as observed in serum. Our results suggest that VCD-induced estropause and E2 replacement have an impact on the profile of serum exosomal miRNAs. The miR-200 family was increased in serum exosomes and ovarian tissue and may be a candidate biomarker of ovarian function.

Chronological and reproductive aging-associated changes in resistance to oxidative stress in post-reproductive female mice

Effort toward reproduction is often thought to negatively influence health and survival. Reproduction has been shown to influence metabolism, but the pathways and mechanisms have yet to be thoroughly elucidated. In the current experiments, our aim was to dissect the role of young and old ovarian tissues in the response to oxidative stress, through changes in liver oxidative stress response proteins. Liver proteins were analyzed in control mice at 4, 13, and 27 months of age and compared to 23-month-old mice which received young ovarian tissue transplants (intact or follicle-depleted) at 13 months of age. In control mice, of the 29 oxidative stress response proteins measured, 31% of the proteins decreased, 52% increased, and 17% were unchanged from 13 to 27 months. The greatest changes were seen during the period of reproductive failure, from 4 to 13 months of age. In transplanted mice, far more proteins were decreased from 13 to 23 months (93% in follicle-containing young ovary recipients; 62% in follicle-depleted young ovary recipients). Neither transplant group reflected changes seen in control mice between 13 and 27 months. Estradiol levels in transplant recipient mice were not increased compared with age-matched control mice. The current results suggest the presence of a germ cell- and estradiol-independent ovarian influence on aging-associated changes in the response to oxidative stress, which is manifest differently in reproductive-aged adults and post-reproductive-aged mice. The results presented here separate chronological and ovarian aging and the influence of estradiol in the response to aging-associated oxidative stress and support a novel, estradiol-independent role for the ovary in female health and survival.

Dasatinib and quercetin increase testosterone and sperm concentration in mice

Cellular senescence is a defense mechanism to arrest proliferation of damaged cells. The number of senescent cells increases with age in different tissues and contributes to the development of age-related diseases. Old mice treated with senolytics drugs, dasatinib and quercetin (D+Q), have reduced senescent cells burden. The aim of this study was to evaluate the effects of D+Q on testicular function and fertility of male mice. Mice (n = 9/group) received D (5 mg kg-1) and Q (50 mg kg-1) via gavage every moth for three consecutive days from 3 to 8 months of age. At 8 months mice were breed with young non-treated females and euthanized. The treatment of male mice with D+Q increased serum testosterone levels and sperm concentration and decreased abnormal sperm morphology. Sperm motility, seminiferous tubule morphometry, testicular gene expression and fertility were not affected by treatment. There was no effect of D+Q treatment in β-galactosidase activity and in lipofuscin staining in testes. D+Q treatment also did not affect body mass gain and testes mass. In conclusion, D+Q treatment increased serum testosterone levels and sperm concentration and decreased abnormal sperm morphology, however did not affect fertility. Further studies with older mice and different senolytics are necessary to elucidate the effects in the decline of sperm output (quality and quantity) associated with aging.

Estradiol-independent restoration of T-cell function in post-reproductive females

Aging leads to a general decline in protective immunity. The most common age-associated effects are in seen T-cell mediated immune function. Adult mice whose immune systems show only moderate changes in T-cell subsets tend to live longer than age-matched siblings that display extensive T-cell subset aging. Importantly, at the time of reproductive decline, the increase in disease risks in women significantly outpace those of men. In female mice, there is a significant decline in central and peripheral naïve T-cell subsets at the time of reproductive failure. Available evidence indicates that this naïve T-cell decline is sensitive to ovarian function and can be reversed in post-reproductive females by transplantation of young ovaries. The restoration of naïve T-cell subsets due to ovarian transplantation was impressive compared with post-reproductive control mice, but represented only a partial recovery of what was lost from 6 months of age. Apparently, the influence of ovarian function on immune function may be an indirect effect, likely moderated by other physiological functions. Estradiol is significantly reduced in post-reproductive females, but was not increased in post-reproductive females that received new ovaries, suggesting an estradiol-independent, but ovarian-dependent influence on immune function. Further evidence for an estradiol-independent influence includes the restoration of immune function through the transplantation of young ovaries depleted of follicles and through the injection of isolated ovarian somatic cells into the senescent ovaries of old mice. While the restoration of naïve T-cell populations represents only a small part of the immune system, the ability to reverse this important functional parameter independent of estradiol may hold promise for the improvement of post-reproductive female immune health. Further studies of the non-reproductive influence of the ovary will be needed to elucidate the mechanisms of the relationship between the ovary and health.

GH deficiency confers protective advantages against Alzheimer's disease through rescued miRNA expression profile in APP/PS1 mice

Alzheimer's disease (AD) is the most common form of dementia, affecting approximately 6.5 million Americans age 65 or older. AD is characterized by increased cognitive impairment and treatment options available provide minimal disease attenuation. Additionally, diagnostic methods for AD are not conclusive with definitive diagnoses requiring postmortem brain evaluations. Therefore, miRNAs, a class of small, non-coding RNAs, have garnered attention for their ability to regulate a variety of mRNAs and their potential to serve as both therapeutic targets and biomarkers of AD. Several miRNAs have already been implicated with AD and have been found to directly target genes associated with AD pathology. The APP/PS1 mice is an AD model that expresses the human mutated form of the amyloid precursor protein (APP) and presenilin-1 (PS1) genes. In a previous study, it was identified that crossing long-living growth hormone (GH)-deficient Ames dwarf (df/df) mice with APP/PS1 mice provided protection from AD through a reduction in IGF-1, amyloid-β (Aβ) deposition, and gliosis. Hence, we hypothesized that changes in the expression of miRNAs associated with AD mediated such benefits. To test this hypothesis, we sequenced miRNAs in hippocampi of df/df, wild type (+ / +), df/ + /APP/PS1 (phenotypically normal APP/PS1), and df/df/APP/PS1 mice. Results of this study demonstrated significantly upregulated and downregulated miRNAs between df/df/APP/PS1 and df/ + /APP/PS1 mice that suggest the df/df mutation provides protection from AD progression. Additionally, changes in miRNA expression with age were identified in both df/df and wild-type mice as well as df/df/APP/PS1 and APP/PS1 mice, with predictive functional roles in the Pi3k-AKT/mTOR/FOXO pathways potentially contributing to disease pathogenesis.

Specialist and Patient Perspectives on Strategies to Improve Cardiovascular Disease Prevention Among Persons Living with Psoriatic Disease

Background

Psoriasis is an immune-mediated disease associated with excess risk for cardiovascular disease (CVD). Guidelines recognize psoriasis as a CVD risk enhancer; however, psoriasis patients often do not have CVD risk factors identified nor managed.

Objective

This study examines strategies to improve CVD prevention care from the perspective of dermatologists and patients with psoriasis.

Methods

Qualitative interviews were conducted using the Consolidated Framework for Implementation Research to examine the perspectives of physicians (N = 16) and patients with psoriatic disease (N = 16) on barriers/facilitators to CVD prevention. Interviews were transcribed and coded using an integrated approach designed to enhance reliability and validity using NVivo software.

Results

We found three major themes suggesting areas to target for the future: (1) Appropriateness: perceptions of whether CVD care should be deployed in this setting by both clinicians and patients, (2) Feasibility: whether CVD prevention care could be integrated into the current structure of specialist practice, and (3) Care Coordination: an interest by all parties to better integrate a team approach in CVD preventative care to reduce duplicative efforts, work practically in an already existing system rather than reinventing the wheel, and progress with the patients' best interests in mind.

Conclusions

These findings will inform the design of a clinical trial comparing the effectiveness of specialist clinician implementation of CVD guideline-based prevention care in patients with psoriasis. Ultimately, this study aims to increase the lifespan and health of patients living with psoriatic disease by decreasing barriers to their receiving appropriate CVD prevention care.

Senolytic treatment reverses obesity-mediated senescent cell accumulation in the ovary

Senescent cells are in a cell cycle arrest state and accumulate with aging and obesity, contributing to a chronic inflammatory state. Treatment with senolytic drugs dasatinib and quercetin (D + Q) can reduce senescent cell burden in several tissues, increasing lifespan. Despite this, there are few reports about senescent cells accumulating in female reproductive tissues. Therefore, the aim of the study was to characterize the ovarian reserve and its relationship with cellular senescence in genetically obese mice (ob/ob). In experiment 1, ob/ob (n = 5) and wild-type (WT) mice (n = 5) at 12 months of age were evaluated. In experiment 2, 2-month-old female ob/ob mice were treated with senolytics (D + Q, n = 6) or placebo (n = 6) during the 4 months. Obese mice had more senescent cells in ovaries, indicated by increased p21 and p16 and lipofuscin staining and macrophage infiltration. Treatment with D + Q significantly reduced senescent cell burden in ovaries of obese mice. Neither obesity nor treatment with D + Q affected the number of ovarian follicles. In conclusion, our data indicate that obesity due to leptin deficiency increases the load of senescent cells in the ovary, which is reduced by treatment by senolytics. However, neither obesity nor D + Q treatment affected the ovarian reserve.

Aging-associated changes in motor function are ovarian somatic tissue-dependent, but germ cell and estradiol independent in post-reproductive female mice exposed to young ovarian tissue

A critical mediator of evolution is natural selection, which operates by the divergent reproductive success of individuals and results in conformity of an organism with its environment. Reproductive function has evolved to support germline transmission. In mammalian ovaries, this requires healthy, active gonad function, and follicle development. However, healthy follicles do not contribute to germline transmission in a dead animal. Therefore, support of the health and survival of the organism, in addition to fertility, must be considered as an integral part of reproductive function. Reproductive and chronological aging both impose a burden on health and increase disease rates. Tremors are a common movement disorder and are often correlated with increasing age. Muscle quality is diminished with age and these declines are gender-specific and are influenced by menopause. In the current experiments, we evaluated aging-associated and reproduction-influenced changes in motor function, utilizing changes in tremor amplitude and grip strength. Tremor amplitude was increased with aging in normal female mice. This increase in tremor amplitude was prevented in aged female mice that received ovarian tissue transplants, both in mice that received germ cell-containing or germ cell-depleted ovarian tissue. Grip strength was decreased with aging in normal female mice. This decrease in grip strength was prevented in aged female mice that received either germ cell-containing or germ cell-depleted tissue transplants. As expected, estradiol levels decreased with aging in normal female mice. Estradiol levels did not change with exposure to young ovarian tissues/cells. Surprisingly, estradiol levels were not increased in aged females that received ovaries from actively cycling, young donors. Overall, tremor amplitude and grip strength were negatively influenced by aging and positively influenced by exposure to young ovarian tissues/cells in aged female mice, and this positive influence was independent of ovarian germ cells and estradiol levels. These findings provide a strong incentive for further investigation of the influence of ovarian somatic tissue on health. In addition, changes in tremor amplitude may serve as an additional marker of biological age.

The interrelationship between female reproductive aging and survival

The link between survival and reproductive function is demonstrated across many species and is under both long-term evolutionary pressures and short-term environmental pressures. Loss of reproductive function is common in mammals and is strongly correlated with increased rates of disease in both males and females. However, the reproduction-associated change in disease rates is more abrupt and more severe in women, who benefit from a significant health advantage over men until the age of menopause. Young women with early ovarian failure also suffer from increased disease risks, further supporting the role of ovarian function in female health. Contemporary experiments where the influence of young ovarian tissue has been restored in post-reproductive-aged females with surgical manipulation were found to increase survival significantly. In these experiments, young, intact ovaries were used to replace the aged ovaries of females that had already reached reproductive cessation. As has been seen previously in primitive species, when the young mammalian ovaries were depleted of germ cells prior to transplantation to the post-reproductive female, survival was increased even further than with germ cell-containing young ovaries. Thus, extending reproductive potential significantly increases survival and appears to be germ cell and ovarian hormone-independent. The current review will discuss historical and contemporary observations and theories that support the link between reproduction and survival and provide hope for future clinical applications to decrease menopause-associated increases in disease risks.

Specific PIWI-Interacting RNAs and Related Small Noncoding RNAs Are Associated With Ovarian Aging in Ames Dwarf (df/df) Mice

The Ames dwarf (df/df) mouse is a well-established model for delayed aging. MicroRNAs (miRNAs), the most studied small noncoding RNAs (sncRNAs), may regulate ovarian aging to maintain a younger ovarian phenotype in df/df mice. In this study, we profile other types of ovarian sncRNAs, PIWI-interacting RNAs (piRNAs) and piRNA-like RNAs (piLRNAs), in young and aged df/df and normal mice. Half of the piRNAs derive from transfer RNA fragments (tRF-piRNAs). Aging and dwarfism alter the ovarian expression of these novel sncRNAs. Specific tRF-piRNAs that increased with age might target and decrease the expression of the breast cancer antiestrogen resistance protein 3 (BCAR3) gene in the ovaries of old df/df mice. A set of piLRNAs that decreased with age and map to D10Wsu102e mRNA may have trans-regulatory functions. Other piLRNAs that decreased with age potentially target and may de-repress transposable elements, leading to a beneficial impact on ovarian aging in df/df mice. These results identify unique responses in ovarian tissues with regard to aging and dwarfism. Overall, our findings highlight the complexity of the aging effects on gene expression and suggest that, in addition to miRNAs, piRNAs, piLRNAs, tRF-piRNAs, and their potential targets can be central players in the maintenance of a younger ovarian phenotype in df/df mice.

Growth hormone increases DNA damage in ovarian follicles and macrophage infiltration in the ovaries

Evidence points to an important role of the growth hormone (GH) in the aging process and longevity. GH-deficient mice are smaller, live longer than normal littermates, and females have an increased ovarian reserve. The aim of the study was to evaluate the role of GH in the ovarian reserve by evaluating DNA damage, macrophage infiltration, and granulosa cell number in primordial and primary follicles. Experiment 1 used GH-deficient Ames dwarf mice (df/df, n = 12) and their normal littermates (N/df, n = 12), receiving GH or saline injections. Experiment 2 included transgenic mice overexpressing bovine GH (bGH) (n = 6) and normal mice (N, n = 6). DNA damage (anti-γH2AX) and macrophage counting (anti-CD68) were evaluated by immunofluorescence. Female df/df mice had lower γH2AX foci intensity in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05), indicating fewer DNA double-strand breaks (DSBs). GH treatment increased DSBs in both df/df and N/df mice. Inversely, bGH mice had a higher quantity of DSBs in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05). Df/df mice showed ovarian tissue with less macrophage infiltration than N/df mice (p < 0.05) and GH treatment increased macrophage infiltration (p < 0.05). In contrast, bGH mice had ovarian tissue with more macrophage infiltration compared to normal mice (p < 0.05). The current study shows that GH increases DNA DSBs in oocytes and granulosa cells and raises macrophage infiltration in the ovaries, pointing to the role of the GH/IGF-I axis in maintenance of oocyte DNA integrity and ovarian macrophage infiltration in mice.

The Interconnections Between Somatic and Ovarian Aging in Murine Models

The mammalian female is born with a limited ovarian reserve of primordial follicles. These primordial follicles are slowly activated throughout the reproductive lifecycle, thereby determining lifecycle length. Once primordial follicles are exhausted, women undergo menopause, which is associated with several metabolic perturbations and a higher mortality risk. Long before exhaustion of the reserve, females experience severe declines in fertility and health. As such, significant efforts have been made to unravel the mechanisms that promote ovarian aging and insufficiency. In this review, we explain how long-living murine models can provide insights in the regulation of ovarian aging. There is now overwhelming evidence that most life-span-extending strategies, and long-living mutant models simultaneously delay ovarian aging. Therefore, it appears that the same mechanisms that regulate somatic aging may also be modulating ovarian aging and germ cell exhaustion. We explore several potential contributing mechanisms including insulin resistance, inflammation, and DNA damage-all of which are hallmarks of cellular aging throughout the body including the ovary. These findings are in alignment with the disposable soma theory of aging, which dictates a trade-off between growth, reproduction, and DNA repair. Therefore, delaying ovarian aging will not only increase the fertility window of middle age females, but may also actively prevent menopausal-related decline in systemic health parameters, compressing the period of morbidity in mid-to-late life in females.

Manipulation of ovarian function influenced glucose metabolism in CBA/J mice

Menopause is associated with a decline in overall health in women. One health aspect impacted is glucose metabolism. As women experience menopause, their metabolism declines dramatically. The current study addressed the influence of ovarian somatic cells on the improvement of metabolic health through transplantations of young, germ cell-depleted ovaries. The purpose of this study is to expand the understanding of female reproductive health on metabolism. Control mice were grouped by age and treatment mice were age-matched. Treatment mice were placed into one of three groups: 1) mice received germ cell-depleted ovaries, 2) mice received germ cell-containing ovaries, and 3) mice received ovarian somatic cells via injection directly to their original ovary. All mice were subject to a glucose tolerance test, during which a bolus of dextrose was administered, and blood glucose levels were collected and recorded. Mice were euthanized between 680 and 700 days. Metabolic results showed an improvement of glucose metabolism in both germ cell-depleted and germ cell-containing groups compared to controls. No significance difference was noted between the germ cell-containing and germ cell-depleted groups. Somatic cell injection groups also showed improved glucose metabolism compared to controls. This experiment has shown that post-reproductive health is positively influenced by reproductive status. Additionally, somatic cells play an important role in the restoration of health to post-reproductive mice.

Effect of caloric restriction and rapamycin on ovarian aging in mice

Caloric restriction (CR) increases the preservation of the ovarian primordial follicular reserve, which can potentially delay menopause. Rapamycin also increases preservation on the ovarian reserve, with similar mechanism to CR. Therefore, the aim of our study was to evaluate the effects of rapamycin and CR on metabolism, ovarian reserve, and gene expression in mice. Thirty-six female mice were allocated into three groups: control, rapamycin-treated (4 mg/kg body weight every other day), and 30% CR. Caloric restricted females had lower body weight (P < 0.05) and increased insulin sensitivity (P = 0.003), while rapamycin injection did not change body weight (P > 0.05) and induced insulin resistance (P < 0.05). Both CR and rapamycin females displayed a higher number of primordial follicles (P = 0.02 and 0.04, respectively), fewer primary, secondary, and tertiary follicles (P < 0.05) and displayed increased ovarian Foxo3a gene expression (P < 0.05). Despite the divergent metabolic effects of the CR and rapamycin treatments, females from both groups displayed a similar increase in ovarian reserve, which was associated with higher expression of ovarian Foxo3a.

Extension of longevity and reduction of inflammation is ovarian-dependent, but germ cell-independent in post-reproductive female mice

Cardiovascular disease, rare in premenopausal women, increases sharply at menopause and is typically accompanied by chronic inflammation. Previous work in our laboratory demonstrated that replacing senescent ovaries in post-reproductive mice with young, actively cycling ovaries restored many health benefits, including decreased cardiomyopathy and restoration of immune function. Our objective here was to determine if depletion of germ cells from young transplanted ovaries would alter the ovarian-dependent extension of life and health span. Sixty-day-old germ cell-depleted and germ cell-containing ovaries were transplanted to post-reproductive, 17-month-old mice. Mean life span for female CBA/J mice is approximately 644 days. Mice that received germ cell-containing ovaries lived 798 days (maximum = 815 days). Mice that received germ cell-depleted ovaries lived 880 days (maximum = 1046 days), 29% further past the time of surgery than mice that received germ cell-containing ovaries. The severity of inflammation was reduced in all mice that received young ovaries, whether germ cell-containing or germ cell-depleted. Aging-associated inflammatory cytokine changes were reversed in post-reproductive mice by 4 months of new-ovary exposure. In summary, germ cell depletion enhanced the longevity-extending effects of the young, transplanted ovaries and, as with germ cell-containing ovaries, decreased the severity of inflammation, but did so independent of germ cells. Based on these observations, we propose that gonadal somatic cells are programed to preserve the somatic health of the organism with the intent of facilitating future germline transmission. As reproductive potential decreases or is lost, the incentive to preserve the somatic health of the organism is lost as well.

Decreased Sarcopenia in Aged Females with Young Ovary Transplants was Preserved in Mice that Received Germ Cell-Depleted Young Ovaries

Previously, transplantation of young, cycling, ovaries increased life and health span in post-reproductive female mice. The current study addressed the influence of ovarian germ cells in the improvement in health by performing transplantations of young, germ cell-depleted ovaries. The purpose of this study is to further the understanding of reproductive influences on aging health. Control mice were grouped by age. Treatment mice were age-matched and received either germ cell depleted ovaries or germ cell containing ovaries at 400 days of age. All groups underwent health span assays until sacrifice (treatment and age-matched control groups were between 680 and 700 days). Body composition results displayed an improvement of body composition in both treatment groups, compared to the controls, but no significant difference between the germ cell-depleted or germ cell-containing groups. Grip test results showed no improvement in musculoskeletal endurance and no change to mild loss of grip strength with both transplant groups compared to control groups. The research presented here suggests that reproductive status has a positive influence in post-reproductive health. A portion of this influence may be germ cell independent.

Orthotopic Ovarian Transplantation Procedures to Investigate the Life- and Health-span Influence of Ovarian Senescence in Female Mice

Ovarian transplantation was first conducted at Utah State University in 1963. In more recent work, heterochronic transplantation of mammalian ovaries is being used to investigate the health-protective effects of young ovaries in young females. The current procedures employ an orthotopic transplantation method, where allogenic ovaries are transplanted back to their original position in the ovarian bursa. This is in contrast to the more commonly used heterotopic transplantation of ovaries/ovarian tissue subcutaneously or under the kidney capsule. All three locations provide efficient revascularization of the transplanted tissues. However, orthotopic transplantation provides the ovary with the most natural signaling environment and is the only procedure that provides the opportunity for the animal to reproduce naturally post-operatively. One must take care to remove all endogenous ovarian tissue during the ovariectomy procedure. If any endogenous tissue remains or if only one ovary is removed, the transplanted tissue will remain dormant until the existing tissue becomes senescent. While revascularization of the transplanted ovaries occurs very quickly, the transplant recipient can take a considerable amount of time to adapt to a new hypothalamic/pituitary/gonadal/adrenal (HPG/A) axis signaling regime associated with the transplanted tissue. This normally takes about 100 days in the mouse. Therefore, transplantation experiments should be designed to accommodate this adaptation period. Typical results with ovarian transplantation will include changes in the health of the recipient that reflect the age of the transplanted ovary, rather than the chronological age of the recipient.

Wnt10b and Dkk-1 gene therapy differentially influenced trabecular bone architecture, soft tissue integrity, and osteophytosis in a skeletally mature rat model of osteoarthritis

AIMS

Our goals in the current experiments were to determine if (a) upregulation of Wnt signaling would induce osteoarthritis changes in stable stifle joints and (b) if downregulation of Wnt signaling in destabilized joints would influence the progression of OA.

METHODS

At 37 weeks of age, rats were injected in the stifle joint with a recombinant adeno-associated viral vector containing the Wnt-inhibitor Dkk-1 or a Wnt10b transgene. At 40 weeks of age, rats underwent surgical destabilization of the joint. At 50 weeks of age, stifle joints were submitted for micro-computed tomography and histopathological analysis.

RESULTS

Injection of either Wnt10b or Dkk-1 transgenes in stable joints improved bone architectural parameters, but worsened soft tissue integrity. Osteophytosis was decreased by Dkk-1, but unchanged by Wnt10b. Destabilization negatively influenced bone architecture, increased osteophytosis, and decreased soft tissue integrity. Dkk-1 exacerbated the negative effects of destabilization, whereas Wnt10b had little effect on these parameters. Osteophytosis was improved, whereas soft tissue integrity was worsened by both transgenes in destabilized joints.

CONCLUSIONS

The Wnt-inhibitor Dkk-1 does not appear to completely inhibit the effects of Wnt signaling on bone remodeling. In vivo upregulation of Wnt10b and its inhibitor, Dkk-1, can produce both parallel or contrasting phenotypic responses depending on the specific parameter measured and the fidelity of the examined joint. These observations elucidate different roles for Wnt signaling in stable versus destabilized joints and may help to explain the conflicting results previously reported for the role of Dkk-1 in joint disease.

Restoration of immune and renal function in aged females by re-establishment of active ovarian function

Proper immune functioning is necessary to maximize reproductive success. In addition, age-associated uremia in women is often associated with hypothalamic­–pituitary–gonadal dysfunction. In the present experiments, we tested immune and renal function to determine if exposure of postreproductive mice to young, reproductively cycling ovaries would influence non-reproductive physiological functions. Control female CBA/J mice were evaluated at 6, 13 and 16 months of age. Additional mice received new (60-day-old) ovaries at 12 months of age and were evaluated at 16 months of age. Consequently, 6-month-old control mice and 16-month-old recipient mice both possessed 6-month-old ovaries and were reproductively cycling. A significant age-related decline in immune function (T-cell subset analysis) was found in 16-month-old mice, but was improved 64% by ovarian transplantation. Renal function (blood urea nitrogen : creatinine ratio) was also decreased with aging, but ovarian transplantation restored function to levels found in 6-month-old mice. In summary, we have shown that immune and renal function, which are negatively influenced by aging, can be positively influenced or restored by re-establishment of active ovarian function in aged female mice. These findings provide a strong incentive for further investigation of the positive influence of young ovaries on restoration of health in postreproductive females.

Association between Body Condition Score and Cancer Prognosis in Dogs with Lymphoma and Osteosarcoma

Background

In humans and rodents obesity appears to promote some cancers by increasing incidence, tumor aggressiveness, recurrence, and fatality. However, the relationship between obesity and cancer in dogs has not been thoroughly evaluated.

Hypothesis/Objectives

Whether body condition score (BCS) at the time of lymphoma (LSA) or osteosarcoma (OSA) diagnosis in dogs is predictive of survival time (ST) or progression‐free interval (PFI). We hypothesized that an overweight body state at the time of cancer diagnosis would be associated with negative outcomes.

Animals

Dogs with LSA (n = 270) and OSA (n = 54) diagnosed and treated between 2000 and 2010.

Methods

Retrospective case review. Signalment, body weight, BCS, cancer diagnosis and treatment, relevant clinicopathologic values, and survival data were collected. Dogs were grouped by BCS (underweight, ideal, and overweight) and ST and PFI were compared.

Results

Overall, 5.5% of dogs were underweight, 54.0% were ideal weight, and 40.4% were overweight at diagnosis. Underweight dogs with LSA had shorter ST (P = .017) than ideal or overweight dogs. BCS was not associated with ST for OSA (P = .474). Progression‐free interval did not differ among BCS categories for either cancer.

Conclusions and Clinical Importance

Obesity was not associated with adverse outcomes among dogs with LSA or OSA in this retrospective study; however, being underweight at the time of diagnosis of LSA was associated with shorter survival. More research is needed to elucidate the relationship between excessive body weight and cancer development and progression in dogs.

Manipulation of Ovarian Function Significantly Influenced Trabecular and Cortical Bone Volume, Architecture and Density in Mice at Death

Previously, transplantation of ovaries from young, cycling mice into old, postreproductive-age mice increased life span and decreased cardiomyopathy at death. We anticipated that the same factors that increased life span and decreased cardiomyopathy could also influence the progression of orthopedic disease. At 11 months of age, prepubertally ovariectomized and ovary-intact mice (including reproductively cycling and acyclic mice) received new 60-day-old ovaries. At death, epiphyseal bone in the proximal tibia and the distal femur and mid-shaft tibial and femoral diaphyseal bone was analyzed with micro-computed tomography. For qualitative analysis of osteophytosis, we also included mineralized connective tissue within the stifle joint. Prepubertal ovariectomy had the greatest influence on bone volume, ovarian transplantation had the greatest influence on bone architecture and both treatments influenced bone density. Ovarian transplantation increased cortical, but not trabecular bone density and tended to increase osteophytosis and heterotopic mineralization, except in acyclic recipients. These effects may have been dictated by the timing of the treatments, with ovariectomy appearing to influence early development and ovarian transplantation limited to influencing only the postreproductive period. However, major differences observed between cycling, acyclic and ovariectomized recipients of new ovaries may have been, in part due to differences in the levels of hormone receptors present and the responsiveness of specific bone processes to hormone signaling. Changes that resulted from these treatments may represent a compensatory response to normal age-associated, negative, orthopedic changes. Alternatively, differences between treatments may simply be the 'preservation' of unblemished orthopedic conditions, prior to the influence of negative, age-associated effects. These findings may suggest that in women, tailoring hormone replacement therapy to the patient's current reproductive status may improve therapy effectiveness and that beginning therapy earlier may help preserve trabecular bone mineral density that would otherwise be lost during perimenopause.

Multiple recombinant adeno-associated viral vector serotypes display persistent in vivo gene expression in vector-transduced rat stifle joints

Our aim was to investigate serotype-specific cell and tissue-transduction tropisms, transgene expression levels and longevity, and immunogenicity of candidate rAAV serotypes in rat osteochondral cells, tissues, and stifle joints. In vitro, we used six rAAV serotypes and two promoters to transduce synoviocytes and chondrocytes. Serotypes rAAV2/5 and 2/2 yielded the highest transduction efficiency 4 days after transduction. No differences were detected between cytomegalovirus and chicken β-actin promoters. In vivo, intra-articular injection was used to introduce four rAAV serotypes into 4-month-old rats in the left stifle joint. Eleven months later, serotype 2/5 vector, diluted with saline or surfactant, was injected into the right stifle joint of the same rats. Rats were analyzed up to 12 months after initial injection. Bioluminescence was detected at 7 days and all serotypes tested displayed bioluminescence above controls after 1 year in the left stifle. Gene expression was detected in the right stifle joints of all rats with the exception of rats previously injected with serotype 2/5. We observed no difference irrespective of whether the luciferin was injected subcutaneously or intraperitoneally. However, surfactant-diluted vectors led to increased gene expression compared with saline-diluted vectors. Cell- and tissue-specific transduction was observed in rat stifles injected with an nLacZ-containing rAAV. Transduction was greatest in stromal tissues and mesenchymal cell types. Exposure to a specific serotype did not inhibit subsequent transduction with a different serotype at a second vector injection. Including surfactant as a vector diluent increased gene expression within the stifle joint and should be considered for in vivo gene therapy applications.

Resistance to genotoxic stresses in Arctica islandica, the longest living noncolonial animal: is extreme longevity associated with a multistress resistance phenotype?

Bivalve molluscs are newly discovered models of successful aging. Here, we test the hypothesis that extremely long-lived bivalves are not uniquely resistant to oxidative stressors (eg, tert-butyl hydroperoxide, as demonstrated in previous studies) but exhibit a multistress resistance phenotype. We contrasted resistance (in terms of organismal mortality) to genotoxic stresses (including topoisomerase inhibitors, agents that cross-link DNA or impair genomic integrity through DNA alkylation or methylation) and to mitochondrial oxidative stressors in three bivalve mollusc species with dramatically differing life spans: Arctica islandica (ocean quahog), Mercenaria mercenaria (northern quahog), and the Atlantic bay scallop, Argopecten irradians irradians (maximum species life spans: >500, >100, and ~2 years, respectively). With all stressors, the short-lived A i irradians were significantly less resistant than the two longer lived species. Arctica islandica were consistently more resistant than M mercenaria to mortality induced by oxidative stressors as well as DNA methylating agent nitrogen mustard and the DNA alkylating agent methyl methanesulfonate. The same trend was not observed for genotoxic agents that act through cross-linking DNA. In contrast, M mercenaria tended to be more resistant to epirubicin and genotoxic stressors, which cause DNA damage by inhibiting topoisomerases. To our knowledge, this is the first study comparing resistance to genotoxic stressors in bivalve mollusc species with disparate longevities. In line with previous studies of comparative stress resistance and longevity, our data extends, at least in part, the evidence for the hypothesis that an association exists between longevity and a general resistance to multiplex stressors, not solely oxidative stress. This work also provides justification for further investigation into the interspecies differences in stress response signatures induced by a diverse array of stressors in short-lived and long-lived bivalves, including pharmacological agents that elicit endoplasmic reticulum stress and cellular stress caused by activation of innate immunity.

Influence of serotype, cell type, tissue composition, and time after inoculation on gene expression in recombinant adeno-associated viral vector-transduced equine joint tissues

OBJECTIVE

To evaluate transduction efficiency of gene therapy for treatment of osteoarthritis in horses.

SAMPLE

Cartilage and synovial tissues were aseptically collected from the stifle joints of 3 Thoroughbreds; horses were 3, 7, and 12 years old and free from sepsis and long-term drug treatment and were euthanized for reasons unrelated to joint disease.

PROCEDURES

Gene transfer experiments were performed with 8 recombinant adeno-associated viral vector (rAAV) serotypes in monolayer-cultured equine chondrocytes, synovial cells, and mesenchymal stromal cells and in cartilage and synovial tissues.

RESULTS

Serotypes rAAV2/5 and rAAV2/2 yielded the highest transduction efficiency in cultured cells 6 days after transduction. Synovial cells and mesenchymal stromal cells were more readily transduced than were chondrocytes. Serotype rAAV2/6.2 yielded the highest rate of gene expression in both cartilage and synovial tissues at 6 days after inoculation. However, at 30 and 60 days after inoculation, gene expression of serotypes rAAV2/2 and rAAV2/5 surpassed that of rAAV2/6.2 and all other serotypes.

CONCLUSIONS AND CLINICAL RELEVANCE

Maximally expressing serotypes changed between 6 and 30 days in tissues; however, the most efficient serotypes for transduction of joint cells over time were also the most efficient serotypes for transduction of joint tissues. In addition, the low transduction efficiency of articular cartilage tissue was paralleled by a low transduction efficiency of isolated chondrocytes. This suggested that the typically low transduction efficiency of articular cartilage may be attributable in part to the low transduction efficiency of the chondrocytes and not solely a result of the dense cartilage matrix.

Transplantation of young ovaries restored cardioprotective influence in postreproductive-aged mice

The female cardioprotective advantage, present in mammals of a reproductively competent age, is lost during the transition to a postreproductive state. The role of reproductive hormones in this transition is most evident in women with premature ovarian failure, where reduced estrogen production has been associated with an increased incidence of early death from cardiovascular disease. Previously, we reported that postreproductive-aged mice that received young ovaries displayed an increased life span. Subsequent histopathological analysis suggested the presence of a cardioprotective effect associated with the restoration of ovarian influence. This restoration in postreproductive-aged mice produced a sharp decrease in evidence of significant cardiomyopathy at death, compared with sham-transplanted mice (36.0% vs. 73.3%, respectively). Within the intact transplant group, evidence of cardiomyopathy at death was decreased in mice that were reproductively cycling at the time of transplant, compared with acyclic mice (26.7% vs. 50.0%, respectively). This observation reflects the importance of timing in restoration of ovarian influence in this study. Transplantation of young ovaries to intact, postreproductive-aged female mice provided significant, long-term restoration of a cardioprotective benefit, similar to that previously present during a reproductively competent age. In these mice, restoration of ovarian influence through ovarian transplantation may, in effect, have postponed the advance of age-associated cardiomyopathy to a point where the disease did not reach a clinically relevant threshold during the lifetime of the recipients. These results offer support for previous clinical observations suggesting that hormone replacement therapy can produce divergent results if initiated during the perimenopausal period, compared with the postmenopausal ages.

Single nucleotide polymorphisms in uracil-processing genes, intake of one-carbon nutrients and breast cancer risk

BACKGROUND/OBJECTIVES

The misincorporation of uracil into DNA leads to genomic instability. In a previous study, some of us identified four common single nucleotide polymorphisms (SNPs) in uracil-processing genes (rs2029166 and rs7296239 in SMUG1, rs34259 in UNG and rs4775748 in DUT) that were associated with significantly altered levels of uracil in human DNA. We investigated whether any of these SNPs are associated with an altered risk of developing breast cancer and if one-carbon nutrients intake can modify their effects.

SUBJECTS/METHODS

We genotyped the four SNPs in 1077 cases of incident breast cancer and 1910 age and race-matched controls in the Western New York Exposures and Breast Cancer (WEB) Study and examined associations with breast cancer risk and interactions with intake of folate, vitamins B6 and B12.

RESULTS

After adjustment for known risk factors for breast cancer, there was increased risk of breast cancer among postmenopausal women who were heterozygous for either of the two SMUG1 SNPs (odds ratio (OR) 1.29, 95% confidence interval (CI) 1.07-1.56) and OR 1.29, 95% CI 1.07-1.55, respectively). Among premenopausal women, increased risk associated with the SMUG1 rs2029166 genotype was limited to those with low folate intake. There were no other interactions with vitamins B(6) or B(12) intake.

CONCLUSIONS

Our study suggests that the four selected SNPs are not robust determinants of breast cancer risk, but that the two SNPs in SMUG1 might modestly alter the risk of breast cancer. However, the increase in risk among heterozygotes in the two SNPs in SMUG1, which is thought to be the most active glycosylase in vivo, raises the possibility that subtle 'heterosis' effects on cancer risk might be produced by these SNPs.

Transplantation of young ovaries to old mice increased life span in transplant recipients

Previously we reported that prepubertally ovariectomized mice that received young transplanted ovaries at a postreproductive age showed a 40% increase in life expectancy. To study this phenomenon in greater detail, 11-month-old ovariectomized and ovary-intact CBA/J mice underwent ovarian transplantation with 60-day-old ovaries or a sham surgery. Results from observations on transplant recipients in the current study extended our previous results. Whereas intact control mice lived an average of 726 days, transplant recipients lived an average of 770 days (i.e., 780 days for intact recipients and 757 days for ovariectomized recipients). If intact recipients had ceased reproductive cycling by the time of transplant, we observed a further increase in mean life span to 811 days. These results demonstrate that young ovaries enhanced longevity when transplanted to old mice and that ovarian status, examined by means of ovariectomy and ovarian transplantation, clearly influenced the potential of young transplanted ovaries to positively impact longevity.

Analysis of the outcome in male and female patients using a unisex total knee replacement system

Gender-specific total knee replacement has generated much interest recently. We reviewed 1970 Sigma knees implanted in 920 women and 592 men with a mean age of 69.7 years. At a mean follow-up of 7.3 years (minimum, five years), we found minimal differences in the outcome between genders. At the final follow-up, men had a higher overall Knee Society score and more osteolysis (3.8% vs 1.1%). However, there were no significant differences between men and women in terms of complications or improvements in knee function, pain score or range of movement. The estimated ten-year survivorship was 97% in women and 98% in men (p = 0.96). We concluded that there was little difference in outcome between the genders treated by a modern unisex design of total knee replacement in this large multicentre study.

Perinatal physiology in cloned and normal calves: physical and clinical characteristics

The period immediately after birth is a vital time for all newborn calves as the cardiovascular, respiratory, and other organ systems adapt to life ex utero. Reported neonatal mortality rates suggest this period to be especially critical in cloned calves; yet prospective, controlled studies on the physiological status of these calves are lacking. The objectives of this study were to compare neonatal (birth to 48 h of age) physical and clinical characteristics and placental morphology of cloned and embryo transfer control calves delivered by cesarean section after induced labor. All calves were raised under specialized neonatal-care protocols at a large-animal veterinary research and teaching hospital. Cloned calves were similar to controls for many parameters studied. Notable exceptions included developmental delays of important physical adjustment parameters and enlargement of the umbilical region. Placentas associated with cloned calves contained fewer total placentomes, a twofold increase in surface area and mass per placentome, and a shift in placentome morphology toward larger, flatter placentomes. The most striking clinical variations detected in clones were hypoglycemia and hyperfructosemia, both measures of carbohydrate metabolism. Because the placenta is known to be the source of plasma fructose in newborn calves, increased fructose production by the cloned placenta may be an important factor in the etiology of umbilical and cardiac anomalies in clones observed in this and other studies.

Perinatal Physiology in Cloned And Normal Calves: Hematologic And Biochemical Profiles

Although a majority of clones are born normal and apparently healthy, mortality rates of nearly 30% are described in many reports. Such losses are a major limitation of cloning technology and represent substantial economic investment as well as justifiable animal health and welfare concerns. Prospective, controlled studies are needed to understand fully the causes of neonatal mortality in clones and to develop preventive and therapeutic strategies to minimize losses. We report here the findings of studies on the hematologic and biochemical profiles of cloned and control calves in the immediate 48-h postpartum period. Cloned calves were similar to control calves for a majority of parameters studied including blood gases, concentrations of plasma proteins, minerals and electrolytes, and white blood cell, neutrophil, lymphocyte, and platelet counts. The most notable differences between clones and controls in this study were reduced red- and white-blood cell counts in clones at birth and 1 h of age. As a group, plasma electrolyte concentrations were more variable in clones, and the variability tended to be shifted either higher (sodium, chloride) or lower (potassium, bicarbonate) than in controls. Previously, we noted differences in carbohydrate parameters, the length of time required for clones to make the neonatal adaptation to life ex utero, and morphology of the cloned placenta. Taken together, our findings suggest that cloned calves experience greater difficulty adjusting to life ex utero and that further research is warranted to determine the nature of the relationship between the physiological differences noted here in clones at birth and concomitant abnormal placental morphology.

The effect of coating single- and double-stranded DNA with the recombinase A protein of Escherichia coli on transgene integration in mice

Embryo survival and transgene integration rates are two major factors that influence the efficiency of transgenic animal production by pronuclear microinjection. Recombinase A protein-coated transgenes were compared for transgene integration and embryo survival with their non-coated counterparts in both single- and double-stranded forms. Murine zygotes were microinjected with a large 30 kb alpha(S1)-casein/human lysozyme DNA construct and a small 5.5 kb beta-lactoglobulin/desaturase DNA construct using four different construct preparations for each gene. The preparations included recombinase A protein-coated, single- and double-stranded DNA constructs and non-coated, single- and double-stranded DNA constructs. Using conventional non-coated, double-stranded DNA constructs, we obtained a transgene integration efficiency of 1.5% (1352 embryos transferred produced 20 transgenic pups). The same double-stranded DNA constructs coated with recombinase A protein yielded a similar percentage of transgene integration (1.1%, 18/1697). Using single-stranded DNA, non-coated constructs produced a transgene integration rate of 0.5%, while none of the 1040 zygotes injected with recombinase A-coated constructs produced transgenic pups. While recombinase A protein coating produced no effect on embryo survival, litter size or pregnancy rate with double-stranded constructs, a detrimental effect was observed on embryo survival (P < 0.001) and pregnancy rate (P < 0.005) with recombinase A protein coating of single-stranded human lysozyme DNA constructs. A trend toward increased embryo survival (P = 0.054) with no difference in pregnancy rate (P > 0.05) was observed with the recombinase A protein coating of single-stranded desaturase constructs. These results suggest that recombinase A protein coating of single- and double-stranded DNA constructs produced no significant differences (P > 0.05) in the efficiency of generating transgenic mice with respect to the percentage of transgenic animals born.

The National Vitamin A Supplementation Program and Subclinical Vitamin A Deficiency among Preschool Children in the Philippines

The prevalence of vitamin A deficiency (serum retinol [SR] < 20 μg/dl) in children from one to five years of age in the Philippines rose from 35.8% to 38% between 1993 and 1998, despite a twice-yearly universal vitamin A capsule distribution program. The Philippines 1998 National Nutrition Survey, with one-time SR measurements from 11,620 children from one to four years of age, collected over an eight-month period from one month to more than six months after distribution of vitamin A capsules, was an opportunity to examine the impact of the program on the children's vitamin A status, using post hoc analysis. Overall, a detectable impact of vitamin A capsules on SR was limited to groups with the highest prevalence of vitamin A deficiency and lasted up to four months after dose administration. In highly urban cities in Visayas, where very high prevalences of deficient SR (SR < 10 μg/dl) were found, the prevalence of deficient SR was reduced from 27% to 9% one to two months after distribution of vitamin A capsules, and to 16% at three to four months. In Mindanao, a statistically significant reduction from 38% to 32% was seen in the prevalence of deficient to low SR (SR < 20 μg/dl) one to four months after distribution of vitamin A capsules. There was no overall reduction in the prevalence of vitamin A deficiency or deficient and low SR (SR < 20 μg/dl) in Luzon, but a significant interaction with stunting was observed in Luzon non-highly urbanized cities. Two aspects are of concern. First, the magnitude of the effect of high-dose vitamin A capsules on SR, and hence on the extent of reduction in deficiency, is limited. Second, the effect does not persist for six months, which is the interval between doses. Thus there is no decrease in the prevalence of deficiency over time. With more frequent dosing (especially to those most deficient in SR), a progressive reduction in vitamin A deficiency could, however, be expected; this hypothesis could be tested. The policy implication arising from these results is that a shift in resources is warranted. In areas of low prevalence of vitamin A deficiency, distribution of vitamin A capsules should be targeted to stunted children. In areas of high prevalence, vitamin A capsules should be distributed to children one to five years old at least three times a year.

Evidence of increased substrate availability to in vitro-derived bovine foetuses and association with accelerated conceptus growth

Changes in placental development have been associated with foetal abnormalities afterin vitroembryo manipulations. This study was designed to investigate bovine conceptus development and substrate levels in plasma and fluids inin vivo- andin vitro-produced (IVP) concepti and neonates.In vivo-produced and IVP embryos were derived by established embryo production procedures. Pregnant animals from both groups were slaughtered on days 90 or 180 of gestation, or allowed to go to term. Conceptus and neonatal physical traits were recorded; foetal, maternal and neonatal blood, and foetal fluids were collected for the determination of blood and fluid chemistry, and glucose, fructose and lactate concentrations. Placental transcripts for specific glucose transporters were determined by quantitative RT-PCR. No significant differences in uterine and conceptus traits were observed between groups on day 90. On day 180, larger uterine, placental and foetal weights, and an increase in placental gross surface area (SA) in IVP pregnancies were associated with increased glucose and fructose accumulation in foetal plasma and associated fluids, with no differences in the expression of components of the glucose transporter system. Therefore, the enlarged placental SA in IVP pregnancies suggests an increase in substrate uptake and transport capacity. Newborn IVP calves displayed higher birth weights and plasma fructose concentrations soon after birth, findings which appeared to be associated with clinical and metabolic distress. Our results indicated larger concepti and increased placental fructogenic capacity in mid- to late IVP pregnancies, features which appeared to be associated with an enhanced substrate supply, potentially glucose, to the conceptus.