Nutrition Alters the Stiffness of Adipose Tissue and Cell Signaling.

Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM). The visceral adipose tissue (VAT) is dynamically altered in response to nutritional regimens that lead to local cues affecting the cells and ECM. The adipocytes are in conjunction with the surrounding ECM that maintains the tissue's niche, provides a scaffold for cells and modulates their signaling. In this study, we provide a better understanding of the crosstalk between nutritional regimens and the ECM's stiffness. Histological analyses showed that the adipocytes in mice fed a high-fat diet (HFD) were increased in size, while the ECM was also altered with changes in mass and composition. HFD-fed mice exhibited a decrease in elastin and an increase in collagenous proteins. Rheometer measurements revealed a stiffer ECM in whole tissue (nECM) and decellularized (deECM) in HFD-fed animals. These alterations in the ECM regulate cellular activity and influence their metabolic function. HFD-fed mice expressed high levels of the receptor for advanced-glycation-end-products (RAGE), indicating that AGEs might play a role in these processes. The cells also exhibited an increase in phosphoserine332 of IRS-1, a decrease in the GLUT4 transporter levels at the cells' membrane, and a consequent reduction in insulin sensitivity. These results show how alterations in the stiffness of ECM proteins can affect the mechanical cues transferred to adipocytes and, thereby, influence the adipocytes' functionality, leading to metabolic disorders.

Pretreatment with gonadotropin-releasing hormone antagonist protects against chemotherapy-induced testicular damage 'in mice.

Background: Testicular toxicity following chemotherapy is of increasing importance with the continuous improvement of survival rates. Gonadotropin-releasing hormone (GnRH) was suggested to protect testis against such toxicity; however, its suppressive quality and mechanism of action are still unclear. We examined whether and how pretreatment with GnRH antagonist protects against the testicular damage caused by chemotherapy. Methods: Mature male mice were injected subcutaneously eight times in 2-day intervals with either saline or GnRH antagonist (Cetrotide; 1 g/mg), followed by an intraperitoneal injection with either saline or cyclophosphamide (CTX;100 mg/kg BW) and sacrificed 2 weeks or 3 months later. Testicular weight, epididymis weight, epididymal sperm count and sperm motility were measured. Serum anti-Müllerian hormone (AMH) was measured by enzyme-linked immunosorbent assay. Immunohistochemistry (Ki-67), immunofluorescence (PCNA, CD34), terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) and computerized analysis were performed to examine testicular proliferation, apoptosis and vascularization. Quantitative real-time PCR was used to assess the amount of spermatogonial reserve (Id4 and Gfra1 mRNAs). Results: Pretreatment with GnRH antagonist transiently reduced testicular weight, epididymal weight, germinal proliferation and sperm count; it also abolished the permanent long-term effect of CTX on these parameters and prevented cyclophosphamide-induced testicular toxicity characterized by apoptosis and serum AMH increase and irreversible loss of spermatogonial reserve. Conclusions: Our findings imply that pretreatment with GnRH antagonist temporarily reduces spermatogenesis and may be used as pretreatment for reducing chemotherapeutic testicular toxicity.

Irinotecan (CPT-11) Treatment Induces Mild Gonadotoxicity.

Background: Gonadal toxicity following chemotherapy is an important issue among the population of young cancer survivors. The inhibitor of DNA topoisomerase I, irinotecan (CPT-11), is widely used for several cancer types. However, little is known about the effect of irinotecan on the fertility of both genders. Thus, the aim of the present study was to evaluate irinotecan gonadotoxicity, using a mouse model. Methods: Mature male and female mice were injected intraperitoneally with either saline (), irinotecan (100 mg/kg) or cyclophosphamide (100 mg/kg); and sacrificed one week or three months later for an acute or long-term toxicity assessment, respectively. We used thorough and advanced fertility assessment by already established methods: Gonadal and epididymal weights, as well as sperm count and sperm motility were determined; serum anti-Müllerian hormone (AMH) was measured by ELISA. Immunohistochemistry (Ki-67), immunofluorescence (PCNA, CD34), terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) and computerized analysis were performed to examine gonadal proliferation, apoptosis and vascularization. qPCR was used to assess the amount of testicular spermatogonia (Id4 and Gafra1 mRNA) and ovarian primordial oocytes reserves (Sohlh2, Nobox and Figla mRNA). Results: Females: Irinotecan administration induced acute ovarian apoptosis and decreased vascularity, as well as a mild, statistically significant, long-term decrease in the number of growing follicles, ovarian weight, and ovarian reserve. Males: Irinotecan administration caused an acute testicular apoptosis and reduced testicular spermatogenesis, but had no effect on vascularity. Irinotecan induced long-term decrease of testicular weight, sperm count and testicular spermatogonia and caused elevated serum AMH. Conclusion: Our findings imply a mild, though irreversible effect of irinotecan on mice gonads.

The Role of PEDF in Reproductive Aging of the Ovary.

Reproductive aging is characterized by a decline in ovarian function and in oocytes' quantity and quality. Pigment epithelium-derived factor (PEDF), a pivotal player in ovarian angiogenic and oxidative balance, was evaluated for its involvement in reproductive aging. Our work examines the initial stage of reproductive aging in women and mice, and the involvement of PEDF in the process. Granulosa cells from reproductively-aged (RA) women and mice (36-44 years old and 9-10 months old, respectively) indicated an increase in the level of PEDF mRNA (qPCR), with yet unchanged levels of AMH and FSHR mRNAs. However, the PEDF protein level in individual women showed an intra-cellular decrease (ELISA), along with a decrease in the corresponding follicular fluid, which reflects the secreted fraction of the protein. The in vitro maturation (IVM) rate in the oocytes of RA mice was lower compared with the oocytes of young mice, demonstrated by a reduced polar body extrusion (PBE) rate. The supplementation of PEDF improved the hampered PBE rate, manifested by a higher number of energetically-competent oocytes (ATP concentration and mtDNA copy number of individual oocytes). Our findings propose PEDF as an early marker of reproductive aging, and a possible therapeutic in vitro agent that could enhance the number of good-quality oocytes in older IVF patients.

Fyn and argonaute 2 participate in maternal-mRNA degradation during mouse oocyte maturation.

Fertilization triggers physiological degradation of maternal-mRNAs, which are then replaced by embryonic transcripts. Ample evidence suggests that Argonaut 2 (AGO2) is a possible post-fertilization regulator of maternal-mRNAs degradation; but its role in degradation of maternal-mRNAs during oocyte maturation remains obscure. Fyn, a member of the Src family kinases (SFKs), and an essential factor in oocyte maturation, was reported to inhibit AGO2 activity in oligodendrocytes. Our aim was to examine the role of Fyn and AGO2 in degradation of maternal-mRNAs during oocyte maturation by either suppressing their activity with SU6656 - an SFKs inhibitor; or by microinjecting DN-Fyn RNA for suppression of Fyn and BCl-137 for suppression of AGO2. Batches of fifteen mouse oocytes or embryos were analyzed by qPCR to measure the expression level of nine maternal-mRNAs that were selected for their known role in oocyte growth, maturation and early embryogenesis. We found that Fyn/SFKs are involved in maintaining the stability of at least four pre-transcribed mRNAs in oocytes at the germinal vesicle (GV) stage, whereas AGO2 had no role at this stage. During in-vivo oocyte maturation, eight maternal-mRNAs were significantly degraded. Inhibition of AGO2 prevented the degreadation of at least five maternal-mRNAs, whereas inhibition of Fyn/SFK prevented degradation of at least five Fyn maternal-mRNAs and two SFKs maternal-mRNAs; pointing at their role in promoting the physiological degradation which occurs during in-vivo oocyte maturation. Our findings imply the involvement of Fyn/SFKs in stabilization of maternal-mRNA at the GV stage and the involvement of Fyn, SFKs and AGO2 in degradation of maternal mRNAs during oocyte maturation.

Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior.

Ultraviolet (UV) light affects endocrinological and behavioral aspects of sexuality via an unknown mechanism. Here we discover that ultraviolet B (UVB) exposure enhances the levels of sex-steroid hormones and sexual behavior, which are mediated by the skin. In female mice, UVB exposure increases hypothalamus-pituitary-gonadal axis hormone levels, resulting in larger ovaries; extends estrus days; and increases anti-Mullerian hormone (AMH) expression. UVB exposure also enhances the sexual responsiveness and attractiveness of females and male-female interactions. Conditional knockout of p53 specifically in skin keratinocytes abolishes the effects of UVB. Thus, UVB triggers a skin-brain-gonadal axis through skin p53 activation. In humans, solar exposure enhances romantic passion in both genders and aggressiveness in men, as seen in analysis of individual questionaries, and positively correlates with testosterone level. Our findings suggest opportunities for treatment of sex-steroid-related dysfunctions.

Pigment epithelium-derived factor negates oxidative stress in mouse oocytes.

Molecular changes, caused by various environmental factors, affect the quality and developmental potential of oocytes. Oxidative stress (OS) is a major factor involved in various gynecologic disorders and/or in aging. Recent studies suggest that elevated reactive oxygen species (ROS) hamper oocyte quality and future embryonic development. Pigment epithelium-derived factor (PEDF) is a pleiotropic protein, known for its antiangiogenic, anti-inflammatory, and antioxidative properties. Our previous findings demonstrate the antioxidative role of rPEDF in maintaining granulosa cell viability. In the current study, we examined the ability of PEDF to negate the adverse impact of OS on oocytes. Maturation rate of oocytes exposed to OS was significantly lower than that of control oocytes. The number of mtDNA copies in OS-exposed oocytes was significantly higher than in control oocytes (>3 times), whereas ATP concentration was significantly lower. Oocytes exposed to OS demonstrated impaired chromosome arrangement at the metaphase plate. PEDF significantly improved maturation rate of untreated OS-exposed oocytes. Moreover, mtDNA copy number, ATP concentration, and chromosome arrangement at the metaphase plate in rPEDF-treated OS-exposed oocytes were restored to the level of control oocytes. Our findings demonstrate that OS hampers the ability of oocytes to undergo proper in vitro maturation. The energetic balance of OS-exposed oocyte is characterized by excessive mtDNA replication and reduced ATP concentration; it hampers the ability of oocytes to perform high fidelity chromosome segregation. PEDF alleviates this damage, improves the rate of oocyte maturation, and preserves mtDNA level and ATP content, thus enabling oocytes to form proper metaphase plate and improve oocyte competence.

Chemotherapy-induced acute vascular injury involves intracellular generation of ROS via activation of the acid sphingomyelinase pathway.

Several categories of chemotherapy confer substantial risk for late-term vascular morbidity and mortality. In the present study, we aimed to investigate the mechanism of acute chemotherapy-induced vascular injury in normal tissues. Specifically, we looked at activation of the acid sphingomyelinase (ASMase)/ceramide pathway, which leads to generation of reactive oxygen species (ROS) and induction of oxidative stress that may result in vascular injury. In particular, we focused on two distinct drugs, doxorubicin (DOX) and cisplatin (CIS) and their effects on normal endothelial cells. In vitro, DOX resulted in increased ASMase activity, intra-cellular ROS production and induction of apoptosis. CIS treatment generated significantly reduced effects in endothelial cells. In-vivo, murine femoral arterial blood flow was measured in real-time, during and after DOX or CIS administration, using fluorescence optical imaging system. While DOX caused constriction of small vessels and disintegration of large vessels' wall, CIS induced minor vascular changes in arterial blood flow, correlating with the in vitro findings. These results demonstrate that DOX induces acute vascular injury by increased ROS production, via activation of ASMase/ceramide pathway, while CIS increases ROS production and its immediate extracellular translocation, without causing detectable acute vascular injury. Our findings may potentially lead to the development of new strategies to prevent long-term cardiovascular morbidity in cancer survivors.

Anti-HER2/neu Antibody Reduces Chemotherapy-Induced Ovarian Toxicity-From Bench to Bedside.

BACKGROUND: Trastuzumab, a humanized anti-human epidermal growth factor receptor 2 (HER2/neu) antibody, is considered a standard treatment in addition to chemotherapy in the adjuvant setting for HER2/neu-positive breast cancer, yet its impact on fertility and ovarian reserve remains obscure. We aimed to study the effect of anti-HER2/neu on chemotherapy-induced ovarian toxicity in both clinical and preclinical settings. METHODS: We prospectively enrolled breast cancer patients below the age of 42 years who were treated with chemotherapy with or without trastuzumab into the study. Anti-Müllerian hormone (AMH) was measured 6 and 12 months post-chemotherapy as an ovarian reserve indicator. In the animal model, pubertal mice were injected with cyclophosphamide or paclitaxel with or without anti-HER2/neu, or saline, and sacrificed 1 week or 3 months later. Ovarian apoptosis, proliferation and vascularity were measured by immunohistochemistry and ovarian reserve was measured by morphometric analysis and serum-AMH. RESULTS: Thirty-three patients with early breast cancer were enrolled into the study. Nineteen patients had HER2/neu negative cancer and were treated with chemotherapy and 14 had HER2/neu positive cancer and were treated with chemotherapy and trastuzumab. In all patients, AMH levels declined to undetectable values immediately post-treatment, but regained for 57.1% of the HER2/neu positive cohort and 36.8% of the negative cohort (p < 0.05). In the preclinical setting, anti-HER2/neu antibody, in combination with chemotherapy, displayed lessened ovarian and vascular damage. CONCLUSIONS: Our results indicate that trastuzumab may alleviate chemotherapy-induced ovarian toxicity that may be mediated via its effect on ovarian vasculature.

Male sterility and reduced female fertility in SCAPER-deficient mice.

Mutations in S-phase cyclin A-associated protein in the endoplasmic reticulum (SCAPER) cause a recessively inherited multisystemic disorder whose main features are retinal degeneration and intellectual disability. SCAPER, originally identified as a cell cycle regulator, was also suggested to be a ciliary protein. Because Scaper mutant males are sterile, we set up to characterize their phenotype. The testes of Scaper mutant mice are significantly smaller than those of WT mice. Histology revealed no signs of spermatogenesis, and seminiferous tubules contained mainly Sertoli cells with a few spermatogonia/spermatogonial stem cells (SSCs). In WT testes, SCAPER is expressed by SSCs and in the various stages of spermatogenesis, as well as in Sertoli cells. In WT spermatozoa SCAPER is not expressed in the flagellum but rather in the head compartment, where it is found both in the nucleus and in the perinuclear region. Scaper mutant females present reduced fertility, manifested by a significantly smaller litter size compared to WT females. Mutant ovaries are similar in size but comprised of significantly less primordial and antral follicles, compared to WT ovaries, while the number of atretic follicles is significantly higher. In WT ovarian follicles SCAPER is expressed in the somatic granulosa cells as well as in the oocyte. In conclusion, our data demonstrate that SCAPER is a crucial component in both male and female reproductive systems. We hypothesize that the reproductive phenotype observed in Scaper mutant mice is rooted in SCAPER's interaction with cyclin A/Cdk2, which play an important role, however different, in male and female gonads.

Pigment epithelium derived factor as a novel multi-target treatment for uterine fibroids.

RESEARCH QUESTION: Does recombinant pigment epithelium derived factor (PEDF) have potential in treating uterine fibroids? DESIGN: In-vitro models that used human leiomyoma and Eker rat uterine leiomyoma (ELT-3) cell lines. The ELT-3 cell line was used to examine cellular targets after adding recombinant PEDF to the culture media. Athymic nude female mice were used as an in-vivo model. They were injected with ELT-3 cells to induce ectopic fibroid lesions, then treated with recombinant PEDF. RESULTS: RNA expression of PEDF and its receptors was found in both leiomyoma cell lines, as well as the expression of PEDF receptors. Addition of recombinant PEDF to the culture medium of leiomyoma cell lines activated ERK in a time-dependent manner, induced down-regulation of vascular endothelial growth factor mRNA and protein, as well as the mRNAs of oestrogen receptors alpha and beta and inhibited cellular proliferation. Treatment of mice-bearing fibroids with recombinant PEDF reduced fibroid growth rate and resulted in smaller tumours. CONCLUSIONS: This study suggests that recombinant PEDF is a putative novel potent physiological treatment for uterine fibroids. It targets several cornerstones of fibroid pathobiology in parallel, including vascular endothelial growth factor and oestrogen receptors, which are needed for vascularization, and restricts fibroid growth and final size in an animal model.

Cancer During Pregnancy: The Role of Vascular Toxicity in Chemotherapy-Induced Placental Toxicity.

Breast cancer is diagnosed in ~0.3% of pregnant women. Studies that have addressed gestational and neonatal outcomes of chemotherapy during pregnancy have demonstrated increased gestational complications including preeclampsia and intrauterine growth retardation. We hypothesized that anthracycline-induced gestational complications could be derived from direct toxicity on the placenta vasculature. Pregnant ICR mice (day E12.5) were treated with doxorubicin (DXR; 8 mg/kg) or saline, while their umbilical cord blood flow was imaged by pulse-wave (PW) Doppler. Mice were euthanized on day E18.5, and their embryos and placentae were collected for further analysis. Unlike control mice, the DXR-treated mice presented an acute change in the umbilical cord's blood flow parameters (velocity time integral and heart rate interval), reduced embryos' weight, reduced placenta efficiency, and modulation in vascular-related pathways of treated placenta proteomics. Apoptosis and proliferation were also enhanced, as demonstrated by TUNEL and proliferating cell nuclear antigen (PCNA) analysis. We further examined the placentae of patients treated with epirubicin (EPI), who had been diagnosed with breast cancer during pregnancy (weeks 27-35). The immunohistochemistry of the EPI-treated human placentae showed enhanced proliferation and apoptosis as compared with matched chemo-naïve placentae, as well as reduced neovascularization (CD34). Our findings suggest that anthracycline-induced vascular insult promotes placental toxicity, and could point to potential agents designated to offset the damage and to reduce gestational complications in pregnant cancer patients.

miR-125a Induces HER2 Expression and Sensitivity to Trastuzumab in Triple-Negative Breast Cancer Lines.

The EGFR/HER2 signaling network is an effective therapeutic target for HER2-positive cancers, which are known for their aggressive biological course. Evidence indicates that the EGFR/HER2 network plays a role in the aggressive basal-like subtype as well. Here, we studied the potential role of miR-125a-3p as a modulator of the EGFR/HER2 pathway in basal-like breast cancer. Over-expression of miR-125a-3p reduced the migratory capability of MDA-MB-231 cells and led to an increase in the expression of ErbB2 transcript and protein. The induced ErbB2 responded to trastuzumab and underwent internalization and subsequent intra-lysosomal degradation. Trastuzumab treatment further reduced the migratory capability and induced the apoptosis of the cells. An in-vivo mouse model, which supported the in-vitro findings, showed a synergistic effect for miR-125a-3p and trastuzumab. Trastuzumab-treated miR-125a-3p-induced tumors were significantly smaller than control induced tumors. Our findings indicate that, in the basal-like subtype of breast cancer, miR-125a-3p may act as a tumor suppressor. miR-125a-3p induces an increase in the expression of ErbB2 that may render the cells suitable for treatment with anti-HER2 therapies.

Pigment epithelium-derived factor (PEDF) negates hyperandrogenic PCOS features.

Polycystic ovary syndrome (PCOS), one of the most common female endocrine disorder, is a prevalent cause of infertility. Hyperandrogenism is a key feature in PCOS and is correlated with increased expression of VEGF and cytokines in the ovaries. We have previously shown that pigment epithelium-derived factor (PEDF), an endogenous protein, presents potent anti-angiogenic and anti-inflammatory activities in the ovary and negates the effects of cytokines and VEGF. Additionally, PEDF plays a role in both pathophysiology and treatment of ovarian-hyperstimulation syndrome (OHSS), frequently seen in PCOS patients. We established hyperandrogenic-PCOS models, both in vivo, using mice exposed prenatally to dihydrotestosterone (DHT) and, in vitro, using human primary granulosa cells (hpGCs) and human granulosa cell line (KGN). In PCOS-induced mice, the mRNA levels of I l-6, V egf and Amh were higher than those of control; yet, treatment with rPEDF decreased these levels. Moreover, treating OHSS-induced PCOS-mice with rPEDF alleviated all OHSS symptoms. Stimulation of hpGCs with DHT resulted in downregulation of PEDF mRNA expression, concomitantly with a significant increase in IL-6 and IL-8 mRNAs expression. However, co-stimulation of DHT with rPEDF attenuated the increase in cytokines expression. The anti-inflammatory effect of PEDF was found to be mediated via PPARγ pathway. Our findings suggest that rPEDF treatment may normalize the ovarian angiogenic-inflammatory imbalance, induced by PCOS-associated hyperandrogenism. Moreover, the therapeutic potency of PEDF in preventing OHSS symptomes offers a rationale for using PEDF as novel physiological treatment for PCOS sequels.

Elucidating the role of pigment epithelium-derived factor (PEDF) in metabolic PCOS models.

PCOS is the most common endocrinopathy in women; associated with obesity and insulin resistance (IR). IR leads to accumulation of advanced-glycation-end-products (AGEs) and their receptor, RAGE. PCOS patients have increased levels of vascular endothelial growth factor (VEGF), interleukin 6/8 (IL-6/8) and anti-Mϋllerian-hormone (AMH). PEDF is a secreted-glycoprotein known for its anti-angiogenic and anti-inflammatory properties. We aimed to elucidate the role of PEDF in the pathogenesis and treatment of PCOS. We used a prenatal PCOS mouse model and fed the female offspring a high-fat diet, inducing metabolic PCOS (met.PCOS) characteristics. Female offspring were divided into three groups: control; met.PCOS; met.PCOS + recombinant PEDF (rPEDF). Met.PCOS mice gained more weight, had elevated serum IL-6 and higher mRNA levels of AMH, PEDF and RAGE in their granulosa cells (GCs) than met.PCOS + rPEDF mice. An in vitro Met.PCOS model in human GCs (KGN) line was induced by prolonged incubation with insulin/AGEs, causing development of IR. Under the same conditions, we observed an elevation of VEGF, IL-6/8 mRNAs, concomitantly with an increase in PEDF mRNA, intracellular protein levels, and an elevation of PEDF receptors (PEDF-Rs) mRNA and protein. Simultaneously, a reduction in the secretion of PEDF from GCs, was measured in the medium. The addition of rPEDF (5 nM) activated P38 signaling, implying that PEDF-Rs maintained functionality, and negated AGE-induced elevation of IL-6/8 and VEGF mRNAs. Decreased PEDF secretion may be a major contributor to hyperangiogenesis and chronic inflammation, which lie at the core of PCOS pathogenesis. rPEDF treatment may restore physiological angiogenesis inflammatory balance, thus suggesting a potential therapeutic role in PCOS.

Pre-ovulatory intercellular regulation of miR-125a-3p within mouse ovarian follicles.

miR-125a-3p, a post-transcription regulator of Fyn kinase, is expressed in mouse pre-ovulatory follicles; its expression within the follicle decreases toward ovulation. Our aim was to follow the synthesis of miR-125a-3p and regulation of its expression in all follicular compartments, focusing on intercellular communication. Mural granulosa cells (GCs) or cumulus cells (CCs) were transfected with either scrambled-miR (negative control) or miR-125a-3p mimic. Freshly isolated GCs or CCs were incubated overnight in culture media conditioned by transfected cells. To examine a possible role of gap junctions in the regulation of miR-125a-3p, we incubated large antral follicles in the presence of carbenoxolone, a gap-junction inhibitor, and triggered them to mature with hGC. Levels of miR-125a family members in GCs, CCs, oocytes, and culture media were measured by qPCR. We showed that miR-125a-3p is synthesized by all follicular components, but is regulated within the follicle as a whole. It is secreted by mural-GCs and taken up by CCs, where it remains functional, and vice versa, mural-GCs can take up miR-125a-3p secreted by CCs. miR-125a-3p is transcribed and accumulated in oocytes throughout oogenesis. Transcriptionally quiescent GV oocytes utilize their accompanying follicular cells to monitor the level of miR-125a-3p within them, as indicated in an ex vivo follicle culture. Our study reveals that miR-125a-3p expression is modulated by a network of intercellular communications within pre-ovulatory follicles, thus enabling a coordinated decrease of miR-125a-3p toward ovulation.

Treosulfan induces distinctive gonadal toxicity compared with busulfan.

Treosulfan (L-treitol-1,4-bis-methanesulfonate) has been increasingly incorporated as a main conditioning protocol for hematopoietic stem cell transplantation in pediatric malignant and non-malignant diseases. Treosulfan presents lower toxicity profile than other conventional alkylating agents containing myeloablative and immunosuppressive traits such as busulfan. Yet, whereas busulfan is considered highly gonadotoxic, the gonadal toxicity profile of treosulfan remains to be elucidated. To study the gonadotoxicity of treosulfan, pubertal and prepubertal male and female mice were injected with treosulfan or busulfan and sacrificed one week, one month or six months later. Testicular function was assessed by measurements of sperm properties, testes and epididymides weights as well as markers for testicular reserve, proliferation and apoptosis. Ovarian function was assessed by measurements of ovary weight and markers for ovarian reserve, proliferation and apoptosis. Treosulfan testicular toxicity was milder than that of busulfan toxicity; possibly by sparing the stem spermatogonia in the testicular sanctuary. By contrast, ovarian toxicity of both treosulfan and busulfan was severe and permanent and displayed irreversible reduction of reserve primordial follicles in the ovaries. Our data indicate that treosulfan exerts a different gonadal toxicity profile from busulfan, manifested by mild testicular toxicity and severe ovarian toxicity.

Premature ovarian aging in BRCA carriers: a prototype of systemic precocious aging?

PURPOSE: Though former evidence implies a correlation of breast cancer susceptibility gene (BRCA) mutation with reduced ovarian reserve, the data is yet inconsistent. Our aim was to investigate biomarkers of ovarian aging in a cohort of young healthy carriers of the BRCA mutation. We hypothesized that the role played by BRCA genes in aging pathways is not exclusive to the ovary. EXPERIMENTAL DESIGN: Healthy female BRCA carriers, 40 years or younger and healthy male BRCA carriers, 50 years or younger, were enrolled in the study. Serum anti-mullerian Hormone (AMH), fibroblast growth factor-23 (FGF-23), Klotho and IL-1 were measured by enzyme-linked immunosorbent assay (ELISA). Ovarian AMH and protein kinase B (AKT) mRNA from BRCA carriers who underwent prophylactic oophorectomy and from age-matched, healthy, non-carriers who underwent partial oophorectomy due to benign conditions were analyzed by qPCR. RESULTS: Thirty-three female (median age 35y) and 20 male (44y) BRCA carriers were enrolled into the study and matched to control non-carriers (34y and 43y, respectively). Serum AMH level was significantly lower in BRCA female carriers than in both non-carrier controls and age-matched nomograms. The levels of ovarian AMH and AKT mRNA were significantly lower in carriers than in controls. The systemic aging cytokines FGF-23, klotho and IL-1 displayed a differential expression in carriers of both genders. FGF-23 level was higher in carriers (P=0.06). CONCLUSIONS: Our results suggest a link between BRCA mutation, accelerated ovarian aging and systemic aging-related pathophysiology.

Regulation of GVBD in mouse oocytes by miR-125a-3p and Fyn kinase through modulation of actin filaments.

Meiotically arrested oocytes are characterized by the presence of the nuclear structure known as germinal-vesicle (GV), the breakdown of which (GVBD) is associated with resumption of meiosis. Fyn is a pivotal factor in resumption of the first meiotic division; its inhibition markedly decreases the fraction of oocytes undergoing GVBD. Here, we reveal that in mouse oocytes Fyn is post-transcriptionally regulated by miR-125a-3p. We demonstrate that in oocytes resuming meiosis miR-125a-3p and Fyn exhibit a reciprocal expression pattern; miR-125a-3p decreases alongside with an increase in Fyn expression. Microinjection of miR-125a-3p inhibits GVBD, an effect that is markedly reduced by Fyn over-expression, and impairs the organization of the actin rim surrounding the nucleus. Lower rate of GVBD is also observed in oocytes exposed to cytochalasin-D or blebbistatin, which interfere with actin polymerization and contractility of actin bundles, respectively. By down-regulating Fyn in HEK-293T cells, miR-125a-3p reduces the interaction between actin and A-type lamins, which constitute the nuclear-lamina. Our findings suggest a mechanism, by which a decrease in miR-125a-3p during oocyte maturation facilitates GVBD by allowing Fyn up-regulation and the resulting stabilization of the interaction between actin and A-type lamins.

Interleukin 1-alpha deficiency increases the expression of Follicle-stimulating hormone receptors in granulosa cells.

Follicle-stimulating hormone receptor (FSHR) is a pivotal regulator of ovarian response to hormonal stimulation. Inflammatory conditions have been linked to lower FSHR expression in granulosa cells (GCs) as well as an attenuated response to hormonal stimulation. The current study aimed to reveal if deficiency and/or blockage of the pro-inflammatory cytokine interleukin 1-alpha (IL1A) increased Fshr expression in rodent GCs. We found elevated Fshr transcript abundance, as assessed by quantitative PCR, in primary GCs isolated from Il1a-knockout compared to wild-type mice, and that the expression of FSHR is significantly higher in Il1a-knockout compared to wild-type ovaries. Supplementing GC cultures with recombinant IL1A significantly lowered Fshr expression in these cells. In accordance with the Fshr expression pattern, proliferation of GCs was higher in follicles from Il1a-knockout mice compared to wild-type mice, as indicated by the MKI67 immunohistochemical staining. Furthermore, treating wild-type mice with anakinra, an IL1 receptor 1 antagonist, significantly increased the expression of Fshr in primary GCs from treated compared to control mice. These data highlight an important interdependency between the potent pro-inflammatory cytokine IL1A and Fshr expression.