19 research outputs found

    Development of an in vitro microenvironment for maturing oocytes

    Get PDF
    The development of in vitro culture systems, comparable to the in vivo microenvironment in terms of effect on the oocyte growth and development could provide a valuable experimental tool for studying the mechanisms governing folliculogenesis. This tool might serve as well for practical clinical, agricultural, zoological, or biotechnological applications. This thesis reports on the importance of the microenvironment for the ovarian folliculogenesis process. The complexity of such a microenvironment was approached with a strategy based on functionalized PEG-hydrogels. The PEG matrix not only served as a scaffold, but it was also used a "reservoir" of immobilized cues. Tethered integrin-binding peptides in combination with other signaling factors aimed at better understanding the interactions of the oocyte and its surrounding granulosa cells that, most probably, determine the efficiency of the actual and the future in vitro mature oocyte production strategies. This work led also to investigating the lymph angiogenesis and the lymphatic transport in the context of oocyte maturation and their impact on mice fertility. In a first step, the mechanical properties of PEG-hydrogel were optimized for culturing secondary follicles. This report shows that the growth of the follicles was highly dependent on the mechanical properties of the surrounding environment. The optimal elastic modulus was found to be close to 900 Pa. In a second step, the effect of Arg-Gly-Asp (RGD) peptide, the minimal integrin-binding sequence, was studied. RGD presence did not influence the follicle growth rate but it significantly improved the quality of the produced oocytes. These findings demonstrated that approaching, biochemically and mechanically, the complexity of the ovarian extracellular matrix could be a winning strategy. The effect of key soluble factors was also investigated in order 1- to confirm their compatibility with the established 3-D culture system and 2- to further improve qualitatively and quantitatively the produced mature oocytes. Various combinations of gonadotropins such as the follicle-stimulating hormone (FSH) or the luteinizing hormone (LH) were tested. Interestingly, the effects of the gonadotropins in the 3-D PEG system were close to their known effects in vivo. Here the aberrant effects of these hormones in the used 2-D systems appeared clearly. c-Kit ligand (KL) is suspected to be one of the most important factors for the activation of primordial follicles and thus for controlling the exit from the resting pool. Previously, studying the effects of the two forms of KL (soluble and membrane-attached) had to cope with the lack of biologically-relevant immobilization strategies. For overcoming this problem, KL constructs were designed to include a substrate sequence for Factor XIIIa (NQEQVSPL or NQEQVSPLRCG). Thus the produced recombinant KL proteins could be enzymatically crosslinked to the PEG matrix. The different constructs of KL, including a wild type extracellular domain, were successfully cloned and produced from mammalian HEK-293 cells. The identity and the activity of the produced proteins were confirmed. Ovarian tissues from four days-old mice were cultured in PEG-hydrogels functionalized with KL. The results showed that the primordial follicles grew and were activated in the PEG-hydrogels where KL was immobilized but not when the soluble form of KL was preset in the medium. This experiment showed that the membrane-attached and the soluble form of KL play a different role in the rodent folliculogenesis. In parallel it was observed that blocking vascular endothelial growth factor receptor-3 (VEGFR-3) signaling had a critical but still unsuspected role in reproduction. This study demonstrates that variation in lymphangiogenesis is a regular, non-pathological event during folliculogenesis in the ovary; blocking lymphangiogenesis, might have an effect on hormone transport and thus on pregnancy. The reported results demonstrates that the blockade of lymphangiogenesis decreases the progesterone and estradioal levels during pregnancy and in fine results in failed fetal development. In conclusion, this study demonstrates the efficiency and the flexibility of a novel 3-D culture system. Circumventing problems inherent to the "on-plastic" standard culture, such as the loss of the granulosa-oocyte interactions, allowed the emergence of a culture system tailored for investigating fundamental folliculogenesis-related questions. Furthermore, the reported culture system might serve as a platform for developing clinical and biotechnology applications

    Acute Kidney Injury due to Menstruation-related Disseminated Intravascular Coagulation in an Adenomyosis Patient: A Case Report

    Get PDF
    The authors report a case of acute kidney injury (AKI) resulting from menstruation-related disseminated intravascular coagulation (DIC) in an adenomyosis patient. A 40-yr-old woman who had received gonadotropin for ovulation induction therapy presented with anuria and an elevated serum creatinine level. Her medical history showed primary infertility with diffuse adenomyosis. On admission, her pregnancy test was negative and her menstrual cycle had started 1 day previously. Laboratory data were consistent with DIC, and it was believed to be related to myometrial injury resulting from heavy intramyometrial menstrual flow. Gonadotropin is considered to play an important role in the development of fulminant DIC. This rare case suggests that physicians should be aware that gonadotropin may provoke fulminant DIC in women with adenomyosis

    Engineering integrin signaling for promoting embryonic stem cell self-renewal in a precisely defined niche

    Get PDF
    We present development and use of a 3D synthetic extracellular matrix (ECM) analog with integrin- specific adhesion ligands to characterize the microenvironmental influences in embryonic stem cell (ESC) self-renewal. Transcriptional analysis of 24 integrin subunits followed by confirmation at the trans- lational and functional levels suggested that integrins a5b1, avb5, a6b1 and a9b1 play important roles in maintenance of stemness in undifferentiated mouse ESCs. Using the well-defined matrix as a tool to activate integrins a5b1 plus avb5, a6b1 and a9b1, individually and in combination, differential integrin activation was demonstrated to exert exquisite control over ESC fate decisions. Simultaneous ligation of these four integrin heterodimers promoted self-renewal, as evidence by prolonged SSEA-1, Oct4 and Nanog expression, and induced Akt1 kinase signaling along with translational regulation of other stemness-related genes. The biofunctional network we have designed based on this knowledge may be useful as a defined niche for regulating ESC pluripotency through selective cell–matrix interactions, and the method we present may be more generally useful for probing matrix interactions in stem cell self- renewal and differentiation

    Baseline Renal Function Predicts Hyponatremia in Liver Cirrhosis Patients Treated with Terlipressin for Variceal Bleeding

    Get PDF
    Objectives. Terlipressin is safely used for acute variceal bleeding. However, side effects, such as hyponatremia, although very rare, can occur. We investigated the development of hyponatremia in cirrhotic patients who had acute variceal bleeding treated with terlipressin and the identification of the risk factors associated with the development of hyponatremia. Design and Methods. This retrospective, case-control study investigated 88 cirrhotic patients who developed hyponatremia and 176 controls that did not develop hyponatremia and were matched in terms of age and gender during the same period following terlipressin administration. Results. The overall change in serum sodium concentration and the mean lowest serum sodium concentration were 3.44 ± 9.55 and 132.44 ± 8.78 mEq/L during treatment, respectively. Multivariate analysis revealed that baseline serum sodium was an independent positive predictor, and the presence of baseline serum creatinine, HBV, DM, creatinine, and shock on admission was independent negative predictors of hyponatremia (P<0.05). Conclusion. The presence of HBV, DM, the baseline serum sodium, shock on admission, and especially baseline creatinine may be predictive of the development of hyponatremia after terlipressin treatment. Therefore, physicians conduct vigilant monitoring associated with severe hyponatremia when cirrhotic patients with preserved renal function are treated with terlipressin for variceal bleeding

    Fimasartan versus perindopril with and without diuretics in the treatment of elderly patients with essential hypertension (Fimasartan in the Senior Subjects (FITNESS)): study protocol for a randomized controlled trial

    Get PDF
    Background Hypertension is an important risk factor for cardiovascular disease, even in the elderly. Fimasartan is a new non-peptide angiotensin II receptor blocker with a selective type I receptor blocking effect. The objective of this study is to confirm the safety and the non-inferiority of the blood pressure–lowering effect of fimasartan compared with those of perindopril, which has been proven safe and effective in elderly patients with hypertension. Methods This is a randomized, double-blind, active-controlled, two-parallel group, optional-titration, multicenter, phase 3 study comparing the efficacy and safety of fimasartan and perindopril arginine. The study population consists of individuals 70 years old or older with essential hypertension. The primary outcome will be a change in sitting systolic blood pressure from baseline after the administration of the investigational product for 8 weeks. The secondary outcomes will be a change in sitting diastolic blood pressure from baseline and changes in sitting systolic blood pressure and diastolic blood pressure from baseline after the administration of the investigational product for 4, 16, and 24 weeks. The sample size will be 119 subjects for each group to confer enough power to test for the primary outcome. Discussion Research to confirm the efficacy and safety of a new medicine compared with those of previously proven anti-hypertensive drugs is beneficial to guide physicians in the selection of therapeutic agents. If it is confirmed that the new drug is not inferior to the existing drug, the drug will be considered as an option in the treatment of hypertension in elderly patients. Trial registration ClinicalTrials.gov Identifier: NCT03246555, registered on July 25, 2017.The study is funded by Boryung Pharmaceutical Co., Ltd. The company was involved in all stages of the study conduct and design. Boryung also took responsibility for all costs associated with the development and publishing of the manuscript

    Murine ovarian follicle culture in PEG-hydrogel: Effects of mechanical properties and the hormones FSH and LH on development

    No full text
    The development of an in vitro culture system, comparable to the in vivo environment in terms of effects on oocyte growth and development, could provide a valuable experimental tool for studying the mechanisms governing oocyte development as well as practical clinical, agricultural, zoological, and biotechnological applications. This study reports on the importance of the microenvironment for the ovarian folliculogenesis process. The complexity of such a microenvironment was approached with a strategy based on functionalized PEG-hydrogels. The PEG matrix not only serves as a scaffold, but it is also used a reservoir of immobilized cues. Using tethered integrin-binding peptides in combination with other signaling factors, we aimed at better understanding the interactions of the oocyte and its surrounding granulosa that may determine the efficiency of the actual and the future in vitro mature oocyte production. In a first step, the mechanical properties of PEG-hydrogel were optimized for producing secondary follicles, in which the oocyte is surrounded by two layers of granulosa cells. Follicle growth was highly dependent on the mechanical properties of the surrounding environment, with the optimal elastic modulus being approx. 1 kPa. The effects of key soluble factors were also investigated to confirm their compatibility with the established 3-D culture system and to further qualitatively and quantitatively improve the produced mature oocytes. Accordingly, various combinations of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were tested. Interestingly, the effects of the gonadotropins in the 3-D PEG system were close to their known in vivo effects. In conclusion, this study demonstrates the efficiency and the flexibility of a novel 3-D culture system, PEG-hydrogel. Circumventing problems inherent to the "on-plastic" standard culture, such as the loss of the granulosa-oocyte interactions, allowed the emergence of a culture system tailored for investigating fundamental folliculogenesis-related questions. Furthermore, the reported culture system may serve as a platform for developing clinical and biotechnology applications

    Improved biocompatibility of polyethylenimine (PEI) as a gene carrier by conjugating urocanic acid: In vitro and in vivo

    No full text
    Polyethylenimine (PEI) is a promising gene carrier among polymeric vectors because of its high transfection efficiency, buffering capacity, which is responsible for its escape from endosomes, facility of modification, reasonable price and wide range of molecular weight. However, toxicity of PEI is an important obstacle to overcome for using it as a gene carrier in gene therapy protocols. In our study, PEI (10 kDa) was modified with urocanic acid, which has an imidazole ring (PEIU). This modification of PEI played an important role by improving transfection efficiency and reducing toxicity. The PEIU was condensed with DNA in different nitrogen of polycation/phosphate of DNA (N/P) ratios starting from 1.25. The PEIU/DNA complexes formed smaller (60-80 versus 100-400 nm) and less dispersible particles than PEI/DNA complexes. Cell viability test showed that in all the transfection experiments PEIU was always found less toxic than the PEI on three different cell-lines, Cos-7, HeLa, and 293T. The PEIU demonstrated improved biocompatibility as compared to the PEI. The in vitro transfection experiments showed that the PEIU displayed similar or lower transfection efficiencies than the PEI in the absence of serum. In medium complemented with serum, the PEIU had higher transfection efficiencies than the PEI. In vivo transfection experiments were carried out with intravenous and subcutaneous injections into mice. Five different organs were taken and lysed for quantification of expressed GFP. The quantification of the fluorescence of these organs exhibited that the PEIU has better transfection efficiency in in vivo experiments compared to the PEI. This study generated a strong evidence indicating that PEIU can be considered as a promising versatile gene carrier because of its biocompatibility and good transfection efficiency

    VEGFR-3 Neutralization Inhibits Ovarian Lymphangiogenesis, Follicle Maturation, and Murine Pregnancy

    Get PDF
    Lymphatic vessels surround follicles within the ovary, but their roles in folliculogenesis and pregnancy, as well as the necessity of Lymphangiogenesis in follicle maturation and health, are undefined. We used systemic delivery of mF4-31C1, a specific antagonist vascular endothelial growth factor receptor 3 (VEGFR-3) antibody to block lymphangiogenesis in mice. VEGFR-3 neutralization for 2 weeks before mating blocked ovarian lymphangiogenesis at all stages of follicle maturation, most notably around corpora lutea, without significantly affecting follicular blood angiogenesis. The numbers of oocytes ovulated, fertilized, and implanted in the uterus were normal in these mice; however, pregnancies were unsuccessful because of retarded fetal growth and miscarriage. Fewer patent secondary follicles were isolated from treated ovaries, and isolated blastocysts exhibited reduced cell densities. Embryos from VEGFR-3-neutralized dams developed normally when transferred to untreated surrogates. Conversely, normal embryos transferred into mF4-31C1-treated dams led to the same fetal deficiencies observed with in situ gestation. Although no significant changes were measured in uterine blood or lymphatic vascular densities, VEGFR-3 neutralization reduced serum and ovarian estradiol concentrations during gestation. VEGFR-3 mediated lymphangiogenesis thus appears to modulate the folliculogenic microenvironment and may be necessary for maintenance of hormone levels during pregnancy; both of these are novel roles for the lymphatic vasculature

    Unmasked chronic renal function deterioration after unilateral adrenalectomy in patients with primary aldosteronism

    No full text
    We report 2 cases of chronic estimated glomerular filtration rate (eGFR) decline after unilateral adrenalectomy due to primary aldosteronism. The patients were diagnosed with unilateral adrenal cortical adenoma releasing aldosterone. Two patients were examined for hypertension and hypokalemia. Unilateral laparoscopic adrenalectomy was performed in both cases, and pathology confirmed adrenal cortical adenoma. After adrenalectomy, hypertension and hypokalemia improved to within normal range. However, the eGFR decreased postoperatively, and abdominal computed tomography scan showed decreased kidney size compared to previous images. Kidney biopsy was performed to delineate the exact cause of renal function deterioration and revealed hypertensive changes with chronic interstitial changes, indicating that glomerular hyperfiltration with aldosterone excess masked renal function damage. Physicians have to consider the probability of postadrenalectomy eGFR decline related to chronic hypertensive change
    corecore