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1.
Reprod Biomed Online ; 41(6): 1101-1111, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33012659

ABSTRACT

RESEARCH QUESTION: To determine the relationship between vitamin D (VitD) status and embryological, clinical pregnancy and live birth outcomes in women undergoing IVF. DESIGN: Cross-sectional, observational study conducted at a university-affiliated private IVF clinic. A total of 287 women underwent 287 IVF cycles and received a fresh embryo transfer. Patients had their serum 25-hydroxyvitamin D2/D3 (VitD) determined on the day of oocyte retrieval, which was analysed in relation to blastocyst development rate, clinical pregnancy and live birth outcomes. RESULTS: In stepwise, multivariable logistic regression models, increases in blastocyst development rate, number and quality, along with embryo cryopreservation and utilization rates were associated with women with a sufficient VitD status (≥20 ng/ml). For a single increase in the number of blastocysts generated per cycle or embryos cryopreserved per cycle, the likelihood for the patient to be VitD sufficient was increased by 32% (odds ratio [OR] 1.32, 95% confidence interval [CI] 1.10-1.58, P = 0.002 and OR 1.33, 95% CI 1.10-1.60, P = 0.004, respectively). Clinical pregnancy (40.7% versus 30.8%, P = 0.086) and live birth rates (32.9% versus 25.8%, P = 0.195) in the sufficient VitD group versus the insufficient group were not significantly different and VitD sufficiency was not significantly associated with these outcomes. CONCLUSION: A strong relationship was observed between blastocyst development and VitD sufficiency. However, there was no association between VitD and clinical pregnancy or live birth outcomes. Further larger studies are needed to investigate whether the observed effect on blastocyst development may have downstream implications on subsequent clinical pregnancy or live birth rates, and on a potential mechanism where sufficient VitD concentrations are linked to improved IVF outcomes.


Subject(s)
Embryonic Development/physiology , Fertilization in Vitro , Vitamin D/blood , Adult , Australia/epidemiology , Blastocyst/physiology , Cross-Sectional Studies , Female , Fertilization in Vitro/statistics & numerical data , Humans , Infant, Newborn , Infertility/blood , Infertility/epidemiology , Infertility/therapy , Male , Nutritional Status/physiology , Pregnancy , Treatment Outcome
2.
Clin Exp Reprod Med ; 46(4): 178-188, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31739659

ABSTRACT

OBJECTIVE: To determine the clinical pregnancy (CP) and live birth (LB) rates arising from frozen embryo transfers (FETs) that had been generated under the influence of in vitro fertilization (IVF) adjuvants given to women categorized as poor-prognosis. METHODS: A registered, single-center, retrospective study. A total of 1,119 patients with first FETs cycle include 310 patients with poor prognosis (109 treated with growth hormone [GH], (+)GH group vs. 201 treated with dehydroepiandrosterone, (-)GH group) and 809 patients with good prognosis (as control, (-)Adj (Good) group). RESULTS: The poor-prognosis women were significantly older, with a lower ovarian reserve than the (-)Adj (Good) group, and demonstrated lower chances of CP (p<0.005) and LB (p<0.005). After adjusting for confounders, the chances of both CP and LB in the (+)GH group were not significantly different from those in the (-)Adj (Good) group, indicating that the poor-prognosis patients given GH had similar outcomes to those with a good prognosis. Furthermore, the likelihood of LB was significantly higher for poor-prognosis women given GH than for those who did not receive GH (p<0.028). This was further confirmed in age-matched analyses. CONCLUSION: The embryos cryopreserved from fresh IVF cycles in which adjuvant GH had been administered to women classified as poor-prognosis showed a significant 2.7-fold higher LB rate in subsequent FET cycles than a matched poor-prognosis group. The women with a poor prognosis who were treated with GH had LB outcomes equivalent to those with a good prognosis. We therefore postulate that GH improves some aspect of oocyte quality that confers improved competency for implantation.

3.
Article in English | MEDLINE | ID: mdl-31781044

ABSTRACT

The role of growth hormone (GH) in human fertility is widely debated with some studies demonstrating improvements in oocyte yield, enhanced embryo quality, and in some cases increased live births with concomitant decreases in miscarriage rates. However, the basic biological mechanisms leading to these clinical differences are not well-understood. GH and the closely-related insulin-like growth factor (IGF) promote body growth and development via action on key metabolic organs including the liver, skeletal muscle, and bone. In addition, their expression and that of their complementary receptors have also been detected in various reproductive tissues including the oocyte, granulosa, and testicular cells. Therefore, the GH/IGF axis may directly regulate female and male gamete development, their quality, and ultimately competence for implantation. The ability of GH and IGF to modulate key signal transduction pathways such as the MAP kinase/ERK, Jak/STAT, and the PI3K/Akt pathway along with the subsequent effects on cell division and steroidogenesis indicates that these growth factors are centrally located to alter cell fate during proliferation and survival. In this review, we will explore the function of GH and IGF in regulating normal ovarian and testicular physiology, while also investigating the effects on cell signal transduction pathways with subsequent changes in cell proliferation and steroidogenesis. The aim is to clarify the role of GH in human fertility from a molecular and biochemical point of view.

4.
Article in English | MEDLINE | ID: mdl-31636602

ABSTRACT

The current understanding of human growth hormone (hGH; here GH) action is that the molecule is a 191-amino acid, single-chain polypeptide that is synthesized, stored and secreted by the somatotroph cells within the lateral wings of the anterior pituitary gland. It can be classified as a protein (comprising more than 50 amino acids) but true proteins have tertiary and quaternary chains creating a more complex structure, hence GH is usually classified as a polypeptide. GH is normally secreted at night during sleep and promotes skeletal, visceral and general body growth through the action of somatomedins or IGFs, notably IGF-1. In some tissues, GH action is directed via specific receptors GHRs; these are most abundant in liver, adipose and muscle tissues but have also been shown in granulosa cells, testicular tissues and on the oocyte, as well as in glandular cells of the luteal phase endometrium and decidua; such findings being recent and minimally researched to now. Following engagement with its receptor, the transduction process activates multiple signaling proteins. These all lead to extensive metabolic and mitogenic (growth promoting) responses. Clinically, GH is known to have an important role in pubertal development and is a key hormone for the vigor associated with adolescence and early adult life stages but has a faded presence and role for later adulthood, beyond age 30 years, and is minimally detected in advanced age, beyond 40 years. In association with the rapidly increasing trend for delaying reproduction beyond age 35 years, GH is being widely researched now as a potential adjuvant for infertility treatment in this group who, studies consistently show, have a poorer prognosis than younger females when relying on autologous oocytes. The idea that the age-related reduction in fertility prognosis is a feature of growth hormone deficiency is supported by our studies showing an elevated binding protein IGFBP-3/IGF-1 ratio and this can be reduced to a normal range (matching younger, good prognosis women) by the administration of GH as an adjuvant.

5.
Am J Physiol Cell Physiol ; 317(3): C420-C433, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31216193

ABSTRACT

It is now accepted that nutrient abundance in the blood, especially glucose, leads to the generation of reactive oxygen species (ROS), ultimately leading to increased oxidative stress in a variety of tissues. In the absence of an appropriate compensatory response from antioxidant mechanisms, the cell, or indeed the tissue, becomes overwhelmed by oxidative stress, leading to the activation of intracellular stress-associated pathways. Activation of the same or similar pathways also appears to play a role in mediating insulin resistance, impaired insulin secretion, and late diabetic complications. The ability of antioxidants to protect against the oxidative stress induced by hyperglycemia and elevated free fatty acid (FFA) levels in vitro suggests a causative role of oxidative stress in mediating the latter clinical conditions. In this review, we describe common biochemical processes associated with oxidative stress driven by hyperglycemia and/or elevated FFA and the resulting clinical outcomes: ß-cell dysfunction and peripheral tissue insulin resistance.


Subject(s)
Energy Metabolism/physiology , Insulin Resistance/physiology , Insulin-Secreting Cells/metabolism , Insulin/metabolism , Oxidative Stress/physiology , Animals , Diabetes Mellitus, Type 2/metabolism , Humans , Reactive Oxygen Species/metabolism , Signal Transduction/physiology
7.
Methods Mol Biol ; 1916: 329-340, 2019.
Article in English | MEDLINE | ID: mdl-30535710

ABSTRACT

In type 2 diabetes, prolonged dysregulation of signalling and ß-cell metabolic control leads to ß-cell dysfunction, and is increasingly associated with abnormal metabolic states which disrupt normal cellular physiology. Utilization of appropriate ß-cell models enables a systematic approach to understand the impact of perturbations to the biological system. The BRIN-BD11 ß-cell line is a useful, pre-clinical cell model for ß-cell dysfunction associated with type 2 diabetes, among other metabolic disorders. The present chapter describes detection and analysis of ß-cell dysfunction with respect to changes in bioenergetics and metabolism, generation of intracellular reactive oxygen species, and acute and chronic insulin secretion in the BRIN-BD11 cell line.


Subject(s)
Cell Culture Techniques/methods , Diabetes Mellitus, Type 2/metabolism , In Vitro Techniques/methods , Insulin-Secreting Cells/pathology , Cell Line/metabolism , Cell Line/pathology , Diabetes Mellitus, Type 2/pathology , Glucose/metabolism , Humans , Insulin/metabolism , Insulin-Secreting Cells/metabolism , Reactive Oxygen Species
8.
Reprod Biol ; 18(4): 324-329, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30503182

ABSTRACT

Advanced age is an increasing trend for both males and females seeking in vitro fertilization (IVF). This retrospective cohort study investigated the outcomes of 1280 IVF-related treatment cycles, selecting the first treatment for couples utilizing autologous gametes and who underwent single fresh embryo transfer. Males aged 40-49 years had a 52% reduction in normal sperm motility, while it was markedly reduced by 79% at 50 years or older. However, neither semen parameters nor male age were predictive of clinical pregnancy or live birth chance. In a combination of age groups, cases with Younger Females had the greatest chance of successful outcomes and this was independent of having a younger or older male partner. Specifically, Young Female-Young Male combinations (≤ 35 years) were the most likely to succeed in achieving a clinical pregnancy or live birth (OR 2.84, p < 0.0005 and 3.34, p < 0.0005, respectively), while the Young Female-Old Male group (≤ 35 and >35 years, respectively) had a similar increased chance (OR 2.07, p < 0.0005 and 2.78, p < 0.0005, respectively). This trend strengthened as the Female age cut-off was increased to 38 years and the Male age cut-off increased to 40 or 42 years. Consistently, the groups comprising a Young Female with either a Young Male or Old Male outperformed the groups with an Old Female. Our finding confirms reduced fecundity with advancing female age as the most important parameter. The outcomes were not significantly influenced by semen parameters or male age with respect to the likelihood of clinical pregnancy or live birth.


Subject(s)
Birth Rate , Fertilization in Vitro/methods , Pregnancy Rate , Sperm Injections, Intracytoplasmic/methods , Adult , Age Factors , Female , Humans , Live Birth , Male , Middle Aged , Pregnancy , Pregnancy Outcome , Retrospective Studies , Semen Analysis , Sperm Motility/physiology , Spermatozoa
11.
Reprod Biol ; 18(3): 301-311, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29801776

ABSTRACT

IVF cycles utilizing the ICSI technique for fertilization have been rising over the 25 years since its introduction, with indications now extending beyond male factor infertility. We have performed ICSI for 87% of cases compared with the ANZARD average of 67%. This retrospective study reports on the outcomes of 1547 autologous ART treatments undertaken over a recent 3-year period. Based on various indications, cases were managed within 3 groupings - IVF Only, ICSI Only or IVF-ICSI Split insemination where oocytes were randomly allocated. Overall 567 pregnancies arose from mostly single embryo transfer procedures up to December 2016, with 402 live births, comprising 415 infants and a low fetal abnormality rate (1.9%) was recorded. When the data was adjusted for confounders such as maternal age, measures of ovarian reserve and sperm quality, it appeared that IVF-generated and ICSI-generated embryos had a similar chance of both pregnancy and live birth. In the IVF-ICSI Split model, significantly more ICSI-generated embryos were utilised (2.5 vs 1.8; p < 0.003) with productivity rates of 67.8% for pregnancy and 43.4% for livebirths per OPU for this group. We conclude that ART clinics should apply the insemination method which will maximize embryo numbers and the first treatment for unexplained infertility should be undertaken within the IVF-ICSI Split model. Whilst ICSI-generated pregnancies are reported to have a higher rate of fetal abnormalities, our data is consistent with the view that the finding is not due to the ICSI technique per se.


Subject(s)
Birth Rate , Embryo Implantation/physiology , Sperm Injections, Intracytoplasmic , Adult , Female , Humans , Live Birth , Male , Maternal Age , Ovarian Reserve , Pregnancy , Pregnancy Outcome , Pregnancy Rate , Single Embryo Transfer
12.
Cancer Microenviron ; 11(1): 71-84, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29637435

ABSTRACT

Within the tumour stroma, a heterogeneous population of cell types reciprocally regulates cell proliferation, which considerably affects the progression of the disease. In this study, using tumour conditioned medium (TCM) derived from breast tumour cell lines - MCF7 and MDA MB 231, we have demonstrated the differentiation of adipose-derived mesenchymal stem cells (ADSCs) into tumour-associated fibroblasts (TAFs). Since the Wnt signalling pathway is a key signalling pathway driving breast tumour growth, the effect of the Wnt antagonist secreted frizzled-related protein 4 (sFRP4) was also examined. The response of ADSCs to TCM and sFRP4 treatments was determined by using cell viability assay to determine the changes in ADSC viability, immunofluorescence for mesenchymal markers, glucose uptake assay, and glycolysis stress test using the Seahorse Extracellular Flux analyser to determine the glycolytic activity of ADSCs. ADSCs have been shown to acquire a hyper-proliferative state, significantly increasing their number upon short-term and long-term exposure to TCM. Changes have also been observed in the expression of key mesenchymal markers as well as in the metabolic state of ADSCs. SFRP4 significantly inhibited the differentiation of ADSCs into TAFs by reducing cell growth as well as mesenchymal marker expression (cell line-dependent). However, sFRP4 did not induce further significant changes to the altered metabolic phenotype of ADSCs following TCM exposure. Altogether, this study suggests that the breast tumour milieu may transform ADSCs into a tumour-supportive phenotype, which can be altered by Wnt antagonism, but is independent of metabolic changes.

13.
Article in English | MEDLINE | ID: mdl-29445356

ABSTRACT

BACKGROUND: In vitro fertilization (IVF) patients receive various adjuvant therapies to enhance success rates, but the true benefit is actively debated. Growth hormone (GH) and dehydroepiandrosterone (DHEA) supplementation were assessed in women undergoing fresh IVF transfer cycles and categorized as poor prognosis from five criteria. METHODS: Data were retrospectively analyzed from 626 women undergoing 626 IVF cycles, where they received no adjuvant, GH alone, or GH-DHEA in combination. A small group received DHEA alone. The utilization of adjuvants was decided between the attending clinician and the patient depending on various factors including cost. RESULTS: Despite patients being significantly older with lower ovarian reserve, live birth rates were significantly greater with GH alone (18.6%) and with GH-DHEA (13.0%) in comparison to those with no adjuvant (p < 0.003). No significant difference was observed between the GH groups (p = 0.181). Overall, patient age, quality of the transferred embryo, and GH treatment were the only significant independent predictors of live birth chance. Following adjustment for patient age, antral follicle count, and quality of transferred embryo, GH alone and GH-DHEA led to a 7.1-fold and 5.6-fold increase in live birth chance, respectively (p < 0.000). CONCLUSION: These data indicated that GH adjuvant may support more live births, particularly in younger women, and importantly, the positive effects of GH treatment were still observed even if DHEA was also used in combination. However, supplementation with DHEA did not indicate any potentiating benefit or modify the effects of GH treatment. Due to the retrospective design, and the risk of a selection bias, caution is advised in the interpretation of the data.

14.
Reprod Biomed Online ; 36(1): 47-58, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29129407

ABSTRACT

PIVET recombinant FSH (rFSH) dosing algorithms have been designed for rFSH injection pens, providing optimal pregnancy and live birth productivity rates whilst minimizing risk and occurrence of ovarian hyperstimulation syndrome (OHSS). Recently, long-acting recombinant gonadotrophin corifollitropin (Elonva) was approved for use in assisted reproduction, and welcomed by patients as the single injection allowed ovarian stimulation over 7 days without need for multiple injections. Consequently, another rFSH dosing algorithm was devised to incorporate Elonva, and these cycles were compared to standard rFSH agents, Gonal-f and Puregon. Initiated Elonva cycles (n = 165) were compared with 972 cycles initiated with standard rFSH. Elonva replaced standard rFSH dosages across the 200-400 IU range, but provided equivalent oocyte retrieval numbers and live birth outcomes. Elonva is considered risky for women whose antral follicle count is ≥20 follicles, and was inadvertently administered contra-protocol in 19 cycles with ≥20 follicles. However, while oocyte retrieval numbers were higher, raising risk for OHSS, no actual cases ensued. Taken together, this indicated that Elonva was equivalent to standard rFSH stimulation, and consequently has been added to the rFSH algorithms for medium to lower antral follicle counts and represented by green colour coding in the existing PIVET algorithmic charts.


Subject(s)
Follicle Stimulating Hormone, Human/administration & dosage , Ovary/drug effects , Ovulation Induction/statistics & numerical data , Adult , Algorithms , Birth Rate , Cohort Studies , Embryo Transfer/statistics & numerical data , Female , Humans , Middle Aged , Pregnancy , Pregnancy Rate , Young Adult
15.
J Immunol ; 200(1): 260-270, 2018 01 01.
Article in English | MEDLINE | ID: mdl-29167231

ABSTRACT

The ability of macrophages to respond to chemoattractants and inflammatory signals is important for their migration to sites of inflammation and immune activity and for host responses to infection. Macrophages differentiated from the bone marrow (BM) of UV-irradiated mice, even after activation with LPS, migrated inefficiently toward CSF-1 and CCL2. When BM cells were harvested from UV-irradiated mice and transplanted into naive mice, the recipient mice (UV-chimeric) had reduced accumulation of elicited monocytes/macrophages in the peritoneal cavity in response to inflammatory thioglycollate or alum. Macrophages differentiating from the BM of UV-chimeric mice also had an inherent reduced ability to migrate toward chemoattractants in vitro, even after LPS activation. Microarray analysis identified reduced reticulon-1 mRNA expressed in macrophages differentiated from the BM of UV-chimeric mice. By using an anti-reticulon-1 Ab, a role for reticulon-1 in macrophage migration toward both CSF-1 and CCL2 was confirmed. Reticulon-1 subcellular localization to the periphery after exposure to CSF-1 for 2.5 min was shown by immunofluorescence microscopy. The proposal that reduced reticulon-1 is responsible for the poor inherent ability of macrophages to respond to chemokine gradients was supported by Western blotting. In summary, skin exposure to erythemal UV radiation can modulate macrophage progenitors in the BM such that their differentiated progeny respond inefficiently to signals to accumulate at sites of inflammation and immunity.


Subject(s)
Bone Marrow Cells/physiology , Macrophages/physiology , Nerve Tissue Proteins/metabolism , Animals , Antibodies, Blocking/metabolism , Cell Differentiation , Cell Movement/genetics , Cells, Cultured , Chemokine CCL2/metabolism , Female , Lipopolysaccharides/immunology , Macrophage Colony-Stimulating Factor/metabolism , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/genetics , Radiation Chimera , Tissue Array Analysis , Ultraviolet Rays/adverse effects
17.
BMJ Open ; 7(10): e018107, 2017 Oct 08.
Article in English | MEDLINE | ID: mdl-28993395

ABSTRACT

BACKGROUND: Patients undergoing in vitro fertilisation (IVF) receive various adjuvant therapies in order to enhance success rates, but the true benefit is actively debated. Growth hormone (GH) supplementation was assessed in poor-prognosis women undergoing fresh IVF transfer cycles. METHODS: Data were retrospectively analysed from 400 IVF cycles, where 161 women received GH and 239 did not. RESULTS: Clinical pregnancy, live birth rates and corresponding ORs and CIs were significantly greater with GH, despite patients being significantly older with lower ovarian reserve. Patient's age, quality of transferred embryo and GH were the only significant independent predictors of clinical pregnancy (OR: 0.90, 5.00 and 2.49, p<0.002, respectively) and live birth chance (OR: 0.91, 3.90 and 4.75, p<0.014, respectively). GH increased clinical pregnancy chance by 3.42-fold (95% CI 1.82 to 6.44, p<0.0005) and live birth chance by 6.16-fold (95% CI 2.83 to 13.39, p<0.0005) after adjustment for maternal age, antral follicle count and transferred embryo quality. CONCLUSION: These data provided further evidence to indicate that GH may support more live births, particularly in younger women. It also appears that embryos generated under GH have a better implantation potential, but whether the biological mechanism is embryo-mediated or endometrium-mediated is unclear.


Subject(s)
Embryo Transfer/statistics & numerical data , Fertilization in Vitro/methods , Growth Hormone/administration & dosage , Live Birth , Ovulation Induction/methods , Adult , Age Factors , Case-Control Studies , Double-Blind Method , Embryo Transfer/methods , Female , Humans , Middle Aged , Ovarian Reserve/drug effects , Ovulation Induction/statistics & numerical data , Pregnancy , Retrospective Studies , Sperm Injections, Intracytoplasmic/methods , Treatment Failure
18.
Exp Hematol ; 56: 64-68, 2017 12.
Article in English | MEDLINE | ID: mdl-28822771

ABSTRACT

Monocytes/macrophages differentiating from bone marrow (BM) cells pulsed for 2 hours at 37°C with a stabilized derivative of prostaglandin E2, 16,16-dimethyl PGE2 (dmPGE2), migrated less efficiently toward a chemoattractant than monocytes/macrophages differentiated from BM cells pulsed with vehicle. To confirm that the effect on BM cells was long lasting and to replicate human BM transplantation, chimeric mice were established with donor BM cells pulsed for 2 hours with dmPGE2 before injection into marrow-ablated congenic recipient mice. After 12 weeks, when high levels (90%) of engraftment were obtained, regenerated BM-derived monocytes/macrophages differentiating in vitro or in vivo migrated inefficiently toward the chemokines colony-stimulating factor-1 (CSF-1) and chemokine (C-C motif) ligand 2 (CCL2) or thioglycollate, respectively. Our results reveal long-lasting changes to progenitor cells of monocytes/macrophages by a 2-hour dmPGE2 pulse that, in turn, limits the migration of their daughter cells to chemoattractants and inflammatory mediators.


Subject(s)
Bone Marrow Cells/metabolism , Cell Movement/drug effects , Dinoprostone/pharmacology , Macrophages/metabolism , Monocytes/metabolism , 16,16-Dimethylprostaglandin E2/pharmacology , Animals , Bone Marrow Cells/cytology , Chemokine CCL2/metabolism , Macrophage Colony-Stimulating Factor/metabolism , Macrophages/cytology , Mice , Monocytes/cytology
19.
Am J Pathol ; 187(9): 2046-2059, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28708972

ABSTRACT

A systemic immunosuppression follows UV irradiation of the skin of humans and mice. In this study, dendritic cells (DCs) differentiating from the bone marrow (BM) of UV-irradiated mice had a reduced ability to migrate toward the chemokine (C-C motif) ligand 21. Fewer DCs also accumulated in the peritoneal cavity of UV-chimeric mice (ie, mice transplanted with BM from UV-irradiated mice) after injection of an inflammatory stimulus into that site. We hypothesized that different metabolic states underpin altered DC motility. Compared with DCs from the BM of nonirradiated mice, those from UV-irradiated mice produced more lactate, consumed more glucose, and had greater glycolytic flux in a bioenergetics stress test. Greater expression of 3-hydroxyanthranilate 3,4-dioxygenase was identified as a potential contributor to increased glycolysis. Inhibition of 3-hydroxyanthranilate 3,4-dioxygenase by 6-chloro-dl-tryptophan prevented both increased lactate production and reduced migration toward chemokine (C-C motif) ligand 21 by DCs differentiated from BM of UV-irradiated mice. UV-induced prostaglandin E2 has been implicated as an intermediary in the effects of UV radiation on BM cells. DCs differentiating from BM cells pulsed in vitro for 2 hours with dimethyl prostaglandin E2 were functionally similar to those from the BM of UV-irradiated mice. Reduced migration of DCs to lymph nodes associated with increased glycolytic flux may contribute to their reduced ability to initiate new immune responses in UV-irradiated mice.


Subject(s)
Bone Marrow Cells/cytology , Cell Movement/radiation effects , Dendritic Cells/cytology , Glycolysis/physiology , Skin/radiation effects , Ultraviolet Rays , Animals , Bone Marrow Cells/metabolism , Dendritic Cells/metabolism , Dinoprostone/metabolism , Glucose/metabolism , Lactic Acid/metabolism , Mice , Skin/metabolism
20.
Sci Rep ; 7(1): 2661, 2017 06 01.
Article in English | MEDLINE | ID: mdl-28572610

ABSTRACT

Glucagon-like peptide-1 (GLP-1) promotes insulin secretion from pancreatic ß-cells in a glucose dependent manner. Several pathways mediate this action by rapid, kinase phosphorylation-dependent, but gene expression-independent mechanisms. Since GLP-1-induced insulin secretion requires glucose metabolism, we aimed to address the hypothesis that GLP-1 receptor (GLP-1R) signalling can modulate glucose uptake and utilization in ß-cells. We have assessed various metabolic parameters after short and long exposure of clonal BRIN-BD11 ß-cells and rodent islets to the GLP-1R agonist Exendin-4 (50 nM). Here we report for the first time that prolonged stimulation of the GLP-1R for 18 hours promotes metabolic reprogramming of ß-cells. This is evidenced by up-regulation of glycolytic enzyme expression, increased rates of glucose uptake and consumption, as well as augmented ATP content, insulin secretion and glycolytic flux after removal of Exendin-4. In our model, depletion of Hypoxia-Inducible Factor 1 alpha (HIF-1α) impaired the effects of Exendin-4 on glucose metabolism, while pharmacological inhibition of Phosphoinositide 3-kinase (PI3K) or mTOR completely abolished such effects. Considering the central role of glucose catabolism for stimulus-secretion coupling in ß-cells, our findings suggest that chronic GLP-1 actions on insulin secretion include elevated ß-cell glucose metabolism. Moreover, our data reveal novel aspects of GLP-1 stimulated insulin secretion involving de novo gene expression.


Subject(s)
Glucagon-Like Peptide-1 Receptor/metabolism , Glucose/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Insulin-Secreting Cells/metabolism , TOR Serine-Threonine Kinases/metabolism , Animals , Cell Line , Glycolysis , Male , Mice, Inbred C57BL , Mitochondria/metabolism , RNA, Messenger/metabolism , Rats , Signal Transduction , Up-Regulation
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